LCOV - code coverage report
Current view: top level - include/linux - mm.h (source / functions) Hit Total Coverage
Test: fstests of 6.5.0-rc3-acha @ Mon Jul 31 20:08:06 PDT 2023 Lines: 84 116 72.4 %
Date: 2023-07-31 20:08:07 Functions: 10 13 76.9 %

          Line data    Source code
       1             : /* SPDX-License-Identifier: GPL-2.0 */
       2             : #ifndef _LINUX_MM_H
       3             : #define _LINUX_MM_H
       4             : 
       5             : #include <linux/errno.h>
       6             : #include <linux/mmdebug.h>
       7             : #include <linux/gfp.h>
       8             : #include <linux/bug.h>
       9             : #include <linux/list.h>
      10             : #include <linux/mmzone.h>
      11             : #include <linux/rbtree.h>
      12             : #include <linux/atomic.h>
      13             : #include <linux/debug_locks.h>
      14             : #include <linux/mm_types.h>
      15             : #include <linux/mmap_lock.h>
      16             : #include <linux/range.h>
      17             : #include <linux/pfn.h>
      18             : #include <linux/percpu-refcount.h>
      19             : #include <linux/bit_spinlock.h>
      20             : #include <linux/shrinker.h>
      21             : #include <linux/resource.h>
      22             : #include <linux/page_ext.h>
      23             : #include <linux/err.h>
      24             : #include <linux/page-flags.h>
      25             : #include <linux/page_ref.h>
      26             : #include <linux/overflow.h>
      27             : #include <linux/sizes.h>
      28             : #include <linux/sched.h>
      29             : #include <linux/pgtable.h>
      30             : #include <linux/kasan.h>
      31             : #include <linux/memremap.h>
      32             : #include <linux/slab.h>
      33             : 
      34             : struct mempolicy;
      35             : struct anon_vma;
      36             : struct anon_vma_chain;
      37             : struct user_struct;
      38             : struct pt_regs;
      39             : 
      40             : extern int sysctl_page_lock_unfairness;
      41             : 
      42             : void mm_core_init(void);
      43             : void init_mm_internals(void);
      44             : 
      45             : #ifndef CONFIG_NUMA             /* Don't use mapnrs, do it properly */
      46             : extern unsigned long max_mapnr;
      47             : 
      48             : static inline void set_max_mapnr(unsigned long limit)
      49             : {
      50             :         max_mapnr = limit;
      51             : }
      52             : #else
      53             : static inline void set_max_mapnr(unsigned long limit) { }
      54             : #endif
      55             : 
      56             : extern atomic_long_t _totalram_pages;
      57             : static inline unsigned long totalram_pages(void)
      58             : {
      59           0 :         return (unsigned long)atomic_long_read(&_totalram_pages);
      60             : }
      61             : 
      62             : static inline void totalram_pages_inc(void)
      63             : {
      64             :         atomic_long_inc(&_totalram_pages);
      65             : }
      66             : 
      67             : static inline void totalram_pages_dec(void)
      68             : {
      69             :         atomic_long_dec(&_totalram_pages);
      70             : }
      71             : 
      72             : static inline void totalram_pages_add(long count)
      73             : {
      74             :         atomic_long_add(count, &_totalram_pages);
      75             : }
      76             : 
      77             : extern void * high_memory;
      78             : extern int page_cluster;
      79             : extern const int page_cluster_max;
      80             : 
      81             : #ifdef CONFIG_SYSCTL
      82             : extern int sysctl_legacy_va_layout;
      83             : #else
      84             : #define sysctl_legacy_va_layout 0
      85             : #endif
      86             : 
      87             : #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
      88             : extern const int mmap_rnd_bits_min;
      89             : extern const int mmap_rnd_bits_max;
      90             : extern int mmap_rnd_bits __read_mostly;
      91             : #endif
      92             : #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
      93             : extern const int mmap_rnd_compat_bits_min;
      94             : extern const int mmap_rnd_compat_bits_max;
      95             : extern int mmap_rnd_compat_bits __read_mostly;
      96             : #endif
      97             : 
      98             : #include <asm/page.h>
      99             : #include <asm/processor.h>
     100             : 
     101             : #ifndef __pa_symbol
     102             : #define __pa_symbol(x)  __pa(RELOC_HIDE((unsigned long)(x), 0))
     103             : #endif
     104             : 
     105             : #ifndef page_to_virt
     106             : #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x)))
     107             : #endif
     108             : 
     109             : #ifndef lm_alias
     110             : #define lm_alias(x)     __va(__pa_symbol(x))
     111             : #endif
     112             : 
     113             : /*
     114             :  * To prevent common memory management code establishing
     115             :  * a zero page mapping on a read fault.
     116             :  * This macro should be defined within <asm/pgtable.h>.
     117             :  * s390 does this to prevent multiplexing of hardware bits
     118             :  * related to the physical page in case of virtualization.
     119             :  */
     120             : #ifndef mm_forbids_zeropage
     121             : #define mm_forbids_zeropage(X)  (0)
     122             : #endif
     123             : 
     124             : /*
     125             :  * On some architectures it is expensive to call memset() for small sizes.
     126             :  * If an architecture decides to implement their own version of
     127             :  * mm_zero_struct_page they should wrap the defines below in a #ifndef and
     128             :  * define their own version of this macro in <asm/pgtable.h>
     129             :  */
     130             : #if BITS_PER_LONG == 64
     131             : /* This function must be updated when the size of struct page grows above 96
     132             :  * or reduces below 56. The idea that compiler optimizes out switch()
     133             :  * statement, and only leaves move/store instructions. Also the compiler can
     134             :  * combine write statements if they are both assignments and can be reordered,
     135             :  * this can result in several of the writes here being dropped.
     136             :  */
     137             : #define mm_zero_struct_page(pp) __mm_zero_struct_page(pp)
     138             : static inline void __mm_zero_struct_page(struct page *page)
     139             : {
     140             :         unsigned long *_pp = (void *)page;
     141             : 
     142             :          /* Check that struct page is either 56, 64, 72, 80, 88 or 96 bytes */
     143             :         BUILD_BUG_ON(sizeof(struct page) & 7);
     144             :         BUILD_BUG_ON(sizeof(struct page) < 56);
     145             :         BUILD_BUG_ON(sizeof(struct page) > 96);
     146             : 
     147             :         switch (sizeof(struct page)) {
     148             :         case 96:
     149             :                 _pp[11] = 0;
     150             :                 fallthrough;
     151             :         case 88:
     152             :                 _pp[10] = 0;
     153             :                 fallthrough;
     154             :         case 80:
     155             :                 _pp[9] = 0;
     156             :                 fallthrough;
     157             :         case 72:
     158             :                 _pp[8] = 0;
     159             :                 fallthrough;
     160             :         case 64:
     161             :                 _pp[7] = 0;
     162             :                 fallthrough;
     163             :         case 56:
     164             :                 _pp[6] = 0;
     165             :                 _pp[5] = 0;
     166             :                 _pp[4] = 0;
     167             :                 _pp[3] = 0;
     168             :                 _pp[2] = 0;
     169             :                 _pp[1] = 0;
     170             :                 _pp[0] = 0;
     171             :         }
     172             : }
     173             : #else
     174             : #define mm_zero_struct_page(pp)  ((void)memset((pp), 0, sizeof(struct page)))
     175             : #endif
     176             : 
     177             : /*
     178             :  * Default maximum number of active map areas, this limits the number of vmas
     179             :  * per mm struct. Users can overwrite this number by sysctl but there is a
     180             :  * problem.
     181             :  *
     182             :  * When a program's coredump is generated as ELF format, a section is created
     183             :  * per a vma. In ELF, the number of sections is represented in unsigned short.
     184             :  * This means the number of sections should be smaller than 65535 at coredump.
     185             :  * Because the kernel adds some informative sections to a image of program at
     186             :  * generating coredump, we need some margin. The number of extra sections is
     187             :  * 1-3 now and depends on arch. We use "5" as safe margin, here.
     188             :  *
     189             :  * ELF extended numbering allows more than 65535 sections, so 16-bit bound is
     190             :  * not a hard limit any more. Although some userspace tools can be surprised by
     191             :  * that.
     192             :  */
     193             : #define MAPCOUNT_ELF_CORE_MARGIN        (5)
     194             : #define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
     195             : 
     196             : extern int sysctl_max_map_count;
     197             : 
     198             : extern unsigned long sysctl_user_reserve_kbytes;
     199             : extern unsigned long sysctl_admin_reserve_kbytes;
     200             : 
     201             : extern int sysctl_overcommit_memory;
     202             : extern int sysctl_overcommit_ratio;
     203             : extern unsigned long sysctl_overcommit_kbytes;
     204             : 
     205             : int overcommit_ratio_handler(struct ctl_table *, int, void *, size_t *,
     206             :                 loff_t *);
     207             : int overcommit_kbytes_handler(struct ctl_table *, int, void *, size_t *,
     208             :                 loff_t *);
     209             : int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
     210             :                 loff_t *);
     211             : 
     212             : #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
     213             : #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
     214             : #define folio_page_idx(folio, p)        (page_to_pfn(p) - folio_pfn(folio))
     215             : #else
     216             : #define nth_page(page,n) ((page) + (n))
     217             : #define folio_page_idx(folio, p)        ((p) - &(folio)->page)
     218             : #endif
     219             : 
     220             : /* to align the pointer to the (next) page boundary */
     221             : #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
     222             : 
     223             : /* to align the pointer to the (prev) page boundary */
     224             : #define PAGE_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PAGE_SIZE)
     225             : 
     226             : /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
     227             : #define PAGE_ALIGNED(addr)      IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
     228             : 
     229             : #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
     230             : static inline struct folio *lru_to_folio(struct list_head *head)
     231             : {
     232             :         return list_entry((head)->prev, struct folio, lru);
     233             : }
     234             : 
     235             : void setup_initial_init_mm(void *start_code, void *end_code,
     236             :                            void *end_data, void *brk);
     237             : 
     238             : /*
     239             :  * Linux kernel virtual memory manager primitives.
     240             :  * The idea being to have a "virtual" mm in the same way
     241             :  * we have a virtual fs - giving a cleaner interface to the
     242             :  * mm details, and allowing different kinds of memory mappings
     243             :  * (from shared memory to executable loading to arbitrary
     244             :  * mmap() functions).
     245             :  */
     246             : 
     247             : struct vm_area_struct *vm_area_alloc(struct mm_struct *);
     248             : struct vm_area_struct *vm_area_dup(struct vm_area_struct *);
     249             : void vm_area_free(struct vm_area_struct *);
     250             : /* Use only if VMA has no other users */
     251             : void __vm_area_free(struct vm_area_struct *vma);
     252             : 
     253             : #ifndef CONFIG_MMU
     254             : extern struct rb_root nommu_region_tree;
     255             : extern struct rw_semaphore nommu_region_sem;
     256             : 
     257             : extern unsigned int kobjsize(const void *objp);
     258             : #endif
     259             : 
     260             : /*
     261             :  * vm_flags in vm_area_struct, see mm_types.h.
     262             :  * When changing, update also include/trace/events/mmflags.h
     263             :  */
     264             : #define VM_NONE         0x00000000
     265             : 
     266             : #define VM_READ         0x00000001      /* currently active flags */
     267             : #define VM_WRITE        0x00000002
     268             : #define VM_EXEC         0x00000004
     269             : #define VM_SHARED       0x00000008
     270             : 
     271             : /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
     272             : #define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
     273             : #define VM_MAYWRITE     0x00000020
     274             : #define VM_MAYEXEC      0x00000040
     275             : #define VM_MAYSHARE     0x00000080
     276             : 
     277             : #define VM_GROWSDOWN    0x00000100      /* general info on the segment */
     278             : #ifdef CONFIG_MMU
     279             : #define VM_UFFD_MISSING 0x00000200      /* missing pages tracking */
     280             : #else /* CONFIG_MMU */
     281             : #define VM_MAYOVERLAY   0x00000200      /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */
     282             : #define VM_UFFD_MISSING 0
     283             : #endif /* CONFIG_MMU */
     284             : #define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
     285             : #define VM_UFFD_WP      0x00001000      /* wrprotect pages tracking */
     286             : 
     287             : #define VM_LOCKED       0x00002000
     288             : #define VM_IO           0x00004000      /* Memory mapped I/O or similar */
     289             : 
     290             :                                         /* Used by sys_madvise() */
     291             : #define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
     292             : #define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
     293             : 
     294             : #define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
     295             : #define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
     296             : #define VM_LOCKONFAULT  0x00080000      /* Lock the pages covered when they are faulted in */
     297             : #define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
     298             : #define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
     299             : #define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
     300             : #define VM_SYNC         0x00800000      /* Synchronous page faults */
     301             : #define VM_ARCH_1       0x01000000      /* Architecture-specific flag */
     302             : #define VM_WIPEONFORK   0x02000000      /* Wipe VMA contents in child. */
     303             : #define VM_DONTDUMP     0x04000000      /* Do not include in the core dump */
     304             : 
     305             : #ifdef CONFIG_MEM_SOFT_DIRTY
     306             : # define VM_SOFTDIRTY   0x08000000      /* Not soft dirty clean area */
     307             : #else
     308             : # define VM_SOFTDIRTY   0
     309             : #endif
     310             : 
     311             : #define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
     312             : #define VM_HUGEPAGE     0x20000000      /* MADV_HUGEPAGE marked this vma */
     313             : #define VM_NOHUGEPAGE   0x40000000      /* MADV_NOHUGEPAGE marked this vma */
     314             : #define VM_MERGEABLE    0x80000000      /* KSM may merge identical pages */
     315             : 
     316             : #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
     317             : #define VM_HIGH_ARCH_BIT_0      32      /* bit only usable on 64-bit architectures */
     318             : #define VM_HIGH_ARCH_BIT_1      33      /* bit only usable on 64-bit architectures */
     319             : #define VM_HIGH_ARCH_BIT_2      34      /* bit only usable on 64-bit architectures */
     320             : #define VM_HIGH_ARCH_BIT_3      35      /* bit only usable on 64-bit architectures */
     321             : #define VM_HIGH_ARCH_BIT_4      36      /* bit only usable on 64-bit architectures */
     322             : #define VM_HIGH_ARCH_0  BIT(VM_HIGH_ARCH_BIT_0)
     323             : #define VM_HIGH_ARCH_1  BIT(VM_HIGH_ARCH_BIT_1)
     324             : #define VM_HIGH_ARCH_2  BIT(VM_HIGH_ARCH_BIT_2)
     325             : #define VM_HIGH_ARCH_3  BIT(VM_HIGH_ARCH_BIT_3)
     326             : #define VM_HIGH_ARCH_4  BIT(VM_HIGH_ARCH_BIT_4)
     327             : #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
     328             : 
     329             : #ifdef CONFIG_ARCH_HAS_PKEYS
     330             : # define VM_PKEY_SHIFT  VM_HIGH_ARCH_BIT_0
     331             : # define VM_PKEY_BIT0   VM_HIGH_ARCH_0  /* A protection key is a 4-bit value */
     332             : # define VM_PKEY_BIT1   VM_HIGH_ARCH_1  /* on x86 and 5-bit value on ppc64   */
     333             : # define VM_PKEY_BIT2   VM_HIGH_ARCH_2
     334             : # define VM_PKEY_BIT3   VM_HIGH_ARCH_3
     335             : #ifdef CONFIG_PPC
     336             : # define VM_PKEY_BIT4  VM_HIGH_ARCH_4
     337             : #else
     338             : # define VM_PKEY_BIT4  0
     339             : #endif
     340             : #endif /* CONFIG_ARCH_HAS_PKEYS */
     341             : 
     342             : #if defined(CONFIG_X86)
     343             : # define VM_PAT         VM_ARCH_1       /* PAT reserves whole VMA at once (x86) */
     344             : #elif defined(CONFIG_PPC)
     345             : # define VM_SAO         VM_ARCH_1       /* Strong Access Ordering (powerpc) */
     346             : #elif defined(CONFIG_PARISC)
     347             : # define VM_GROWSUP     VM_ARCH_1
     348             : #elif defined(CONFIG_IA64)
     349             : # define VM_GROWSUP     VM_ARCH_1
     350             : #elif defined(CONFIG_SPARC64)
     351             : # define VM_SPARC_ADI   VM_ARCH_1       /* Uses ADI tag for access control */
     352             : # define VM_ARCH_CLEAR  VM_SPARC_ADI
     353             : #elif defined(CONFIG_ARM64)
     354             : # define VM_ARM64_BTI   VM_ARCH_1       /* BTI guarded page, a.k.a. GP bit */
     355             : # define VM_ARCH_CLEAR  VM_ARM64_BTI
     356             : #elif !defined(CONFIG_MMU)
     357             : # define VM_MAPPED_COPY VM_ARCH_1       /* T if mapped copy of data (nommu mmap) */
     358             : #endif
     359             : 
     360             : #if defined(CONFIG_ARM64_MTE)
     361             : # define VM_MTE         VM_HIGH_ARCH_0  /* Use Tagged memory for access control */
     362             : # define VM_MTE_ALLOWED VM_HIGH_ARCH_1  /* Tagged memory permitted */
     363             : #else
     364             : # define VM_MTE         VM_NONE
     365             : # define VM_MTE_ALLOWED VM_NONE
     366             : #endif
     367             : 
     368             : #ifndef VM_GROWSUP
     369             : # define VM_GROWSUP     VM_NONE
     370             : #endif
     371             : 
     372             : #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
     373             : # define VM_UFFD_MINOR_BIT      37
     374             : # define VM_UFFD_MINOR          BIT(VM_UFFD_MINOR_BIT)  /* UFFD minor faults */
     375             : #else /* !CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
     376             : # define VM_UFFD_MINOR          VM_NONE
     377             : #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
     378             : 
     379             : /* Bits set in the VMA until the stack is in its final location */
     380             : #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY)
     381             : 
     382             : #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
     383             : 
     384             : /* Common data flag combinations */
     385             : #define VM_DATA_FLAGS_TSK_EXEC  (VM_READ | VM_WRITE | TASK_EXEC | \
     386             :                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
     387             : #define VM_DATA_FLAGS_NON_EXEC  (VM_READ | VM_WRITE | VM_MAYREAD | \
     388             :                                  VM_MAYWRITE | VM_MAYEXEC)
     389             : #define VM_DATA_FLAGS_EXEC      (VM_READ | VM_WRITE | VM_EXEC | \
     390             :                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
     391             : 
     392             : #ifndef VM_DATA_DEFAULT_FLAGS           /* arch can override this */
     393             : #define VM_DATA_DEFAULT_FLAGS  VM_DATA_FLAGS_EXEC
     394             : #endif
     395             : 
     396             : #ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
     397             : #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
     398             : #endif
     399             : 
     400             : #ifdef CONFIG_STACK_GROWSUP
     401             : #define VM_STACK        VM_GROWSUP
     402             : #define VM_STACK_EARLY  VM_GROWSDOWN
     403             : #else
     404             : #define VM_STACK        VM_GROWSDOWN
     405             : #define VM_STACK_EARLY  0
     406             : #endif
     407             : 
     408             : #define VM_STACK_FLAGS  (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
     409             : 
     410             : /* VMA basic access permission flags */
     411             : #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
     412             : 
     413             : 
     414             : /*
     415             :  * Special vmas that are non-mergable, non-mlock()able.
     416             :  */
     417             : #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
     418             : 
     419             : /* This mask prevents VMA from being scanned with khugepaged */
     420             : #define VM_NO_KHUGEPAGED (VM_SPECIAL | VM_HUGETLB)
     421             : 
     422             : /* This mask defines which mm->def_flags a process can inherit its parent */
     423             : #define VM_INIT_DEF_MASK        VM_NOHUGEPAGE
     424             : 
     425             : /* This mask represents all the VMA flag bits used by mlock */
     426             : #define VM_LOCKED_MASK  (VM_LOCKED | VM_LOCKONFAULT)
     427             : 
     428             : /* Arch-specific flags to clear when updating VM flags on protection change */
     429             : #ifndef VM_ARCH_CLEAR
     430             : # define VM_ARCH_CLEAR  VM_NONE
     431             : #endif
     432             : #define VM_FLAGS_CLEAR  (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR)
     433             : 
     434             : /*
     435             :  * mapping from the currently active vm_flags protection bits (the
     436             :  * low four bits) to a page protection mask..
     437             :  */
     438             : 
     439             : /*
     440             :  * The default fault flags that should be used by most of the
     441             :  * arch-specific page fault handlers.
     442             :  */
     443             : #define FAULT_FLAG_DEFAULT  (FAULT_FLAG_ALLOW_RETRY | \
     444             :                              FAULT_FLAG_KILLABLE | \
     445             :                              FAULT_FLAG_INTERRUPTIBLE)
     446             : 
     447             : /**
     448             :  * fault_flag_allow_retry_first - check ALLOW_RETRY the first time
     449             :  * @flags: Fault flags.
     450             :  *
     451             :  * This is mostly used for places where we want to try to avoid taking
     452             :  * the mmap_lock for too long a time when waiting for another condition
     453             :  * to change, in which case we can try to be polite to release the
     454             :  * mmap_lock in the first round to avoid potential starvation of other
     455             :  * processes that would also want the mmap_lock.
     456             :  *
     457             :  * Return: true if the page fault allows retry and this is the first
     458             :  * attempt of the fault handling; false otherwise.
     459             :  */
     460             : static inline bool fault_flag_allow_retry_first(enum fault_flag flags)
     461             : {
     462     3845902 :         return (flags & FAULT_FLAG_ALLOW_RETRY) &&
     463             :             (!(flags & FAULT_FLAG_TRIED));
     464             : }
     465             : 
     466             : #define FAULT_FLAG_TRACE \
     467             :         { FAULT_FLAG_WRITE,             "WRITE" }, \
     468             :         { FAULT_FLAG_MKWRITE,           "MKWRITE" }, \
     469             :         { FAULT_FLAG_ALLOW_RETRY,       "ALLOW_RETRY" }, \
     470             :         { FAULT_FLAG_RETRY_NOWAIT,      "RETRY_NOWAIT" }, \
     471             :         { FAULT_FLAG_KILLABLE,          "KILLABLE" }, \
     472             :         { FAULT_FLAG_TRIED,             "TRIED" }, \
     473             :         { FAULT_FLAG_USER,              "USER" }, \
     474             :         { FAULT_FLAG_REMOTE,            "REMOTE" }, \
     475             :         { FAULT_FLAG_INSTRUCTION,       "INSTRUCTION" }, \
     476             :         { FAULT_FLAG_INTERRUPTIBLE,     "INTERRUPTIBLE" }, \
     477             :         { FAULT_FLAG_VMA_LOCK,          "VMA_LOCK" }
     478             : 
     479             : /*
     480             :  * vm_fault is filled by the pagefault handler and passed to the vma's
     481             :  * ->fault function. The vma's ->fault is responsible for returning a bitmask
     482             :  * of VM_FAULT_xxx flags that give details about how the fault was handled.
     483             :  *
     484             :  * MM layer fills up gfp_mask for page allocations but fault handler might
     485             :  * alter it if its implementation requires a different allocation context.
     486             :  *
     487             :  * pgoff should be used in favour of virtual_address, if possible.
     488             :  */
     489             : struct vm_fault {
     490             :         const struct {
     491             :                 struct vm_area_struct *vma;     /* Target VMA */
     492             :                 gfp_t gfp_mask;                 /* gfp mask to be used for allocations */
     493             :                 pgoff_t pgoff;                  /* Logical page offset based on vma */
     494             :                 unsigned long address;          /* Faulting virtual address - masked */
     495             :                 unsigned long real_address;     /* Faulting virtual address - unmasked */
     496             :         };
     497             :         enum fault_flag flags;          /* FAULT_FLAG_xxx flags
     498             :                                          * XXX: should really be 'const' */
     499             :         pmd_t *pmd;                     /* Pointer to pmd entry matching
     500             :                                          * the 'address' */
     501             :         pud_t *pud;                     /* Pointer to pud entry matching
     502             :                                          * the 'address'
     503             :                                          */
     504             :         union {
     505             :                 pte_t orig_pte;         /* Value of PTE at the time of fault */
     506             :                 pmd_t orig_pmd;         /* Value of PMD at the time of fault,
     507             :                                          * used by PMD fault only.
     508             :                                          */
     509             :         };
     510             : 
     511             :         struct page *cow_page;          /* Page handler may use for COW fault */
     512             :         struct page *page;              /* ->fault handlers should return a
     513             :                                          * page here, unless VM_FAULT_NOPAGE
     514             :                                          * is set (which is also implied by
     515             :                                          * VM_FAULT_ERROR).
     516             :                                          */
     517             :         /* These three entries are valid only while holding ptl lock */
     518             :         pte_t *pte;                     /* Pointer to pte entry matching
     519             :                                          * the 'address'. NULL if the page
     520             :                                          * table hasn't been allocated.
     521             :                                          */
     522             :         spinlock_t *ptl;                /* Page table lock.
     523             :                                          * Protects pte page table if 'pte'
     524             :                                          * is not NULL, otherwise pmd.
     525             :                                          */
     526             :         pgtable_t prealloc_pte;         /* Pre-allocated pte page table.
     527             :                                          * vm_ops->map_pages() sets up a page
     528             :                                          * table from atomic context.
     529             :                                          * do_fault_around() pre-allocates
     530             :                                          * page table to avoid allocation from
     531             :                                          * atomic context.
     532             :                                          */
     533             : };
     534             : 
     535             : /* page entry size for vm->huge_fault() */
     536             : enum page_entry_size {
     537             :         PE_SIZE_PTE = 0,
     538             :         PE_SIZE_PMD,
     539             :         PE_SIZE_PUD,
     540             : };
     541             : 
     542             : /*
     543             :  * These are the virtual MM functions - opening of an area, closing and
     544             :  * unmapping it (needed to keep files on disk up-to-date etc), pointer
     545             :  * to the functions called when a no-page or a wp-page exception occurs.
     546             :  */
     547             : struct vm_operations_struct {
     548             :         void (*open)(struct vm_area_struct * area);
     549             :         /**
     550             :          * @close: Called when the VMA is being removed from the MM.
     551             :          * Context: User context.  May sleep.  Caller holds mmap_lock.
     552             :          */
     553             :         void (*close)(struct vm_area_struct * area);
     554             :         /* Called any time before splitting to check if it's allowed */
     555             :         int (*may_split)(struct vm_area_struct *area, unsigned long addr);
     556             :         int (*mremap)(struct vm_area_struct *area);
     557             :         /*
     558             :          * Called by mprotect() to make driver-specific permission
     559             :          * checks before mprotect() is finalised.   The VMA must not
     560             :          * be modified.  Returns 0 if mprotect() can proceed.
     561             :          */
     562             :         int (*mprotect)(struct vm_area_struct *vma, unsigned long start,
     563             :                         unsigned long end, unsigned long newflags);
     564             :         vm_fault_t (*fault)(struct vm_fault *vmf);
     565             :         vm_fault_t (*huge_fault)(struct vm_fault *vmf,
     566             :                         enum page_entry_size pe_size);
     567             :         vm_fault_t (*map_pages)(struct vm_fault *vmf,
     568             :                         pgoff_t start_pgoff, pgoff_t end_pgoff);
     569             :         unsigned long (*pagesize)(struct vm_area_struct * area);
     570             : 
     571             :         /* notification that a previously read-only page is about to become
     572             :          * writable, if an error is returned it will cause a SIGBUS */
     573             :         vm_fault_t (*page_mkwrite)(struct vm_fault *vmf);
     574             : 
     575             :         /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */
     576             :         vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf);
     577             : 
     578             :         /* called by access_process_vm when get_user_pages() fails, typically
     579             :          * for use by special VMAs. See also generic_access_phys() for a generic
     580             :          * implementation useful for any iomem mapping.
     581             :          */
     582             :         int (*access)(struct vm_area_struct *vma, unsigned long addr,
     583             :                       void *buf, int len, int write);
     584             : 
     585             :         /* Called by the /proc/PID/maps code to ask the vma whether it
     586             :          * has a special name.  Returning non-NULL will also cause this
     587             :          * vma to be dumped unconditionally. */
     588             :         const char *(*name)(struct vm_area_struct *vma);
     589             : 
     590             : #ifdef CONFIG_NUMA
     591             :         /*
     592             :          * set_policy() op must add a reference to any non-NULL @new mempolicy
     593             :          * to hold the policy upon return.  Caller should pass NULL @new to
     594             :          * remove a policy and fall back to surrounding context--i.e. do not
     595             :          * install a MPOL_DEFAULT policy, nor the task or system default
     596             :          * mempolicy.
     597             :          */
     598             :         int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
     599             : 
     600             :         /*
     601             :          * get_policy() op must add reference [mpol_get()] to any policy at
     602             :          * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
     603             :          * in mm/mempolicy.c will do this automatically.
     604             :          * get_policy() must NOT add a ref if the policy at (vma,addr) is not
     605             :          * marked as MPOL_SHARED. vma policies are protected by the mmap_lock.
     606             :          * If no [shared/vma] mempolicy exists at the addr, get_policy() op
     607             :          * must return NULL--i.e., do not "fallback" to task or system default
     608             :          * policy.
     609             :          */
     610             :         struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
     611             :                                         unsigned long addr);
     612             : #endif
     613             :         /*
     614             :          * Called by vm_normal_page() for special PTEs to find the
     615             :          * page for @addr.  This is useful if the default behavior
     616             :          * (using pte_page()) would not find the correct page.
     617             :          */
     618             :         struct page *(*find_special_page)(struct vm_area_struct *vma,
     619             :                                           unsigned long addr);
     620             : };
     621             : 
     622             : #ifdef CONFIG_NUMA_BALANCING
     623             : static inline void vma_numab_state_init(struct vm_area_struct *vma)
     624             : {
     625             :         vma->numab_state = NULL;
     626             : }
     627             : static inline void vma_numab_state_free(struct vm_area_struct *vma)
     628             : {
     629             :         kfree(vma->numab_state);
     630             : }
     631             : #else
     632             : static inline void vma_numab_state_init(struct vm_area_struct *vma) {}
     633             : static inline void vma_numab_state_free(struct vm_area_struct *vma) {}
     634             : #endif /* CONFIG_NUMA_BALANCING */
     635             : 
     636             : #ifdef CONFIG_PER_VMA_LOCK
     637             : /*
     638             :  * Try to read-lock a vma. The function is allowed to occasionally yield false
     639             :  * locked result to avoid performance overhead, in which case we fall back to
     640             :  * using mmap_lock. The function should never yield false unlocked result.
     641             :  */
     642             : static inline bool vma_start_read(struct vm_area_struct *vma)
     643             : {
     644             :         /* Check before locking. A race might cause false locked result. */
     645             :         if (vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq))
     646             :                 return false;
     647             : 
     648             :         if (unlikely(down_read_trylock(&vma->vm_lock->lock) == 0))
     649             :                 return false;
     650             : 
     651             :         /*
     652             :          * Overflow might produce false locked result.
     653             :          * False unlocked result is impossible because we modify and check
     654             :          * vma->vm_lock_seq under vma->vm_lock protection and mm->mm_lock_seq
     655             :          * modification invalidates all existing locks.
     656             :          */
     657             :         if (unlikely(vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq))) {
     658             :                 up_read(&vma->vm_lock->lock);
     659             :                 return false;
     660             :         }
     661             :         return true;
     662             : }
     663             : 
     664             : static inline void vma_end_read(struct vm_area_struct *vma)
     665             : {
     666             :         rcu_read_lock(); /* keeps vma alive till the end of up_read */
     667             :         up_read(&vma->vm_lock->lock);
     668             :         rcu_read_unlock();
     669             : }
     670             : 
     671             : static bool __is_vma_write_locked(struct vm_area_struct *vma, int *mm_lock_seq)
     672             : {
     673    15882178 :         mmap_assert_write_locked(vma->vm_mm);
     674             : 
     675             :         /*
     676             :          * current task is holding mmap_write_lock, both vma->vm_lock_seq and
     677             :          * mm->mm_lock_seq can't be concurrently modified.
     678             :          */
     679    15882178 :         *mm_lock_seq = READ_ONCE(vma->vm_mm->mm_lock_seq);
     680    15882178 :         return (vma->vm_lock_seq == *mm_lock_seq);
     681             : }
     682             : 
     683    15882178 : static inline void vma_start_write(struct vm_area_struct *vma)
     684             : {
     685    15882178 :         int mm_lock_seq;
     686             : 
     687    15882178 :         if (__is_vma_write_locked(vma, &mm_lock_seq))
     688             :                 return;
     689             : 
     690      419449 :         down_write(&vma->vm_lock->lock);
     691      419456 :         vma->vm_lock_seq = mm_lock_seq;
     692      419456 :         up_write(&vma->vm_lock->lock);
     693             : }
     694             : 
     695             : static inline bool vma_try_start_write(struct vm_area_struct *vma)
     696             : {
     697             :         int mm_lock_seq;
     698             : 
     699             :         if (__is_vma_write_locked(vma, &mm_lock_seq))
     700             :                 return true;
     701             : 
     702             :         if (!down_write_trylock(&vma->vm_lock->lock))
     703             :                 return false;
     704             : 
     705             :         vma->vm_lock_seq = mm_lock_seq;
     706             :         up_write(&vma->vm_lock->lock);
     707             :         return true;
     708             : }
     709             : 
     710             : static inline void vma_assert_write_locked(struct vm_area_struct *vma)
     711             : {
     712             :         int mm_lock_seq;
     713             : 
     714             :         VM_BUG_ON_VMA(!__is_vma_write_locked(vma, &mm_lock_seq), vma);
     715             : }
     716             : 
     717             : static inline void vma_mark_detached(struct vm_area_struct *vma, bool detached)
     718             : {
     719             :         /* When detaching vma should be write-locked */
     720             :         if (detached)
     721             :                 vma_assert_write_locked(vma);
     722             :         vma->detached = detached;
     723             : }
     724             : 
     725             : struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
     726             :                                           unsigned long address);
     727             : 
     728             : #else /* CONFIG_PER_VMA_LOCK */
     729             : 
     730             : static inline bool vma_start_read(struct vm_area_struct *vma)
     731             :                 { return false; }
     732             : static inline void vma_end_read(struct vm_area_struct *vma) {}
     733             : static inline void vma_start_write(struct vm_area_struct *vma) {}
     734             : static inline bool vma_try_start_write(struct vm_area_struct *vma)
     735             :                 { return true; }
     736             : static inline void vma_assert_write_locked(struct vm_area_struct *vma) {}
     737             : static inline void vma_mark_detached(struct vm_area_struct *vma,
     738             :                                      bool detached) {}
     739             : 
     740             : #endif /* CONFIG_PER_VMA_LOCK */
     741             : 
     742             : /*
     743             :  * WARNING: vma_init does not initialize vma->vm_lock.
     744             :  * Use vm_area_alloc()/vm_area_free() if vma needs locking.
     745             :  */
     746             : static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
     747             : {
     748             :         static const struct vm_operations_struct dummy_vm_ops = {};
     749             : 
     750             :         memset(vma, 0, sizeof(*vma));
     751             :         vma->vm_mm = mm;
     752             :         vma->vm_ops = &dummy_vm_ops;
     753             :         INIT_LIST_HEAD(&vma->anon_vma_chain);
     754             :         vma_mark_detached(vma, false);
     755             :         vma_numab_state_init(vma);
     756             : }
     757             : 
     758             : /* Use when VMA is not part of the VMA tree and needs no locking */
     759             : static inline void vm_flags_init(struct vm_area_struct *vma,
     760             :                                  vm_flags_t flags)
     761             : {
     762    15901787 :         ACCESS_PRIVATE(vma, __vm_flags) = flags;
     763             : }
     764             : 
     765             : /* Use when VMA is part of the VMA tree and modifications need coordination */
     766             : static inline void vm_flags_reset(struct vm_area_struct *vma,
     767             :                                   vm_flags_t flags)
     768             : {
     769             :         vma_start_write(vma);
     770             :         vm_flags_init(vma, flags);
     771             : }
     772             : 
     773             : static inline void vm_flags_reset_once(struct vm_area_struct *vma,
     774             :                                        vm_flags_t flags)
     775             : {
     776             :         vma_start_write(vma);
     777             :         WRITE_ONCE(ACCESS_PRIVATE(vma, __vm_flags), flags);
     778             : }
     779             : 
     780             : static inline void vm_flags_set(struct vm_area_struct *vma,
     781             :                                 vm_flags_t flags)
     782             : {
     783      418548 :         vma_start_write(vma);
     784      418539 :         ACCESS_PRIVATE(vma, __vm_flags) |= flags;
     785             : }
     786             : 
     787             : static inline void vm_flags_clear(struct vm_area_struct *vma,
     788             :                                   vm_flags_t flags)
     789             : {
     790    15470346 :         vma_start_write(vma);
     791    15463454 :         ACCESS_PRIVATE(vma, __vm_flags) &= ~flags;
     792             : }
     793             : 
     794             : /*
     795             :  * Use only if VMA is not part of the VMA tree or has no other users and
     796             :  * therefore needs no locking.
     797             :  */
     798             : static inline void __vm_flags_mod(struct vm_area_struct *vma,
     799             :                                   vm_flags_t set, vm_flags_t clear)
     800             : {
     801             :         vm_flags_init(vma, (vma->vm_flags | set) & ~clear);
     802             : }
     803             : 
     804             : /*
     805             :  * Use only when the order of set/clear operations is unimportant, otherwise
     806             :  * use vm_flags_{set|clear} explicitly.
     807             :  */
     808             : static inline void vm_flags_mod(struct vm_area_struct *vma,
     809             :                                 vm_flags_t set, vm_flags_t clear)
     810             : {
     811             :         vma_start_write(vma);
     812             :         __vm_flags_mod(vma, set, clear);
     813             : }
     814             : 
     815             : static inline void vma_set_anonymous(struct vm_area_struct *vma)
     816             : {
     817    15899323 :         vma->vm_ops = NULL;
     818             : }
     819             : 
     820             : static inline bool vma_is_anonymous(struct vm_area_struct *vma)
     821             : {
     822             :         return !vma->vm_ops;
     823             : }
     824             : 
     825             : static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
     826             : {
     827             :         int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
     828             : 
     829             :         if (!maybe_stack)
     830             :                 return false;
     831             : 
     832             :         if ((vma->vm_flags & VM_STACK_INCOMPLETE_SETUP) ==
     833             :                                                 VM_STACK_INCOMPLETE_SETUP)
     834             :                 return true;
     835             : 
     836             :         return false;
     837             : }
     838             : 
     839             : static inline bool vma_is_foreign(struct vm_area_struct *vma)
     840             : {
     841             :         if (!current->mm)
     842             :                 return true;
     843             : 
     844             :         if (current->mm != vma->vm_mm)
     845             :                 return true;
     846             : 
     847             :         return false;
     848             : }
     849             : 
     850             : static inline bool vma_is_accessible(struct vm_area_struct *vma)
     851             : {
     852             :         return vma->vm_flags & VM_ACCESS_FLAGS;
     853             : }
     854             : 
     855             : static inline
     856             : struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max)
     857             : {
     858             :         return mas_find(&vmi->mas, max - 1);
     859             : }
     860             : 
     861             : static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi)
     862             : {
     863             :         /*
     864             :          * Uses mas_find() to get the first VMA when the iterator starts.
     865             :          * Calling mas_next() could skip the first entry.
     866             :          */
     867    30924016 :         return mas_find(&vmi->mas, ULONG_MAX);
     868             : }
     869             : 
     870             : static inline
     871             : struct vm_area_struct *vma_iter_next_range(struct vma_iterator *vmi)
     872             : {
     873             :         return mas_next_range(&vmi->mas, ULONG_MAX);
     874             : }
     875             : 
     876             : 
     877             : static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi)
     878             : {
     879    15462723 :         return mas_prev(&vmi->mas, 0);
     880             : }
     881             : 
     882             : static inline
     883             : struct vm_area_struct *vma_iter_prev_range(struct vma_iterator *vmi)
     884             : {
     885             :         return mas_prev_range(&vmi->mas, 0);
     886             : }
     887             : 
     888             : static inline unsigned long vma_iter_addr(struct vma_iterator *vmi)
     889             : {
     890             :         return vmi->mas.index;
     891             : }
     892             : 
     893             : static inline unsigned long vma_iter_end(struct vma_iterator *vmi)
     894             : {
     895             :         return vmi->mas.last + 1;
     896             : }
     897             : static inline int vma_iter_bulk_alloc(struct vma_iterator *vmi,
     898             :                                       unsigned long count)
     899             : {
     900             :         return mas_expected_entries(&vmi->mas, count);
     901             : }
     902             : 
     903             : /* Free any unused preallocations */
     904             : static inline void vma_iter_free(struct vma_iterator *vmi)
     905             : {
     906             :         mas_destroy(&vmi->mas);
     907             : }
     908             : 
     909             : static inline int vma_iter_bulk_store(struct vma_iterator *vmi,
     910             :                                       struct vm_area_struct *vma)
     911             : {
     912             :         vmi->mas.index = vma->vm_start;
     913             :         vmi->mas.last = vma->vm_end - 1;
     914             :         mas_store(&vmi->mas, vma);
     915             :         if (unlikely(mas_is_err(&vmi->mas)))
     916             :                 return -ENOMEM;
     917             : 
     918             :         return 0;
     919             : }
     920             : 
     921             : static inline void vma_iter_invalidate(struct vma_iterator *vmi)
     922             : {
     923             :         mas_pause(&vmi->mas);
     924             : }
     925             : 
     926             : static inline void vma_iter_set(struct vma_iterator *vmi, unsigned long addr)
     927             : {
     928             :         mas_set(&vmi->mas, addr);
     929             : }
     930             : 
     931             : #define for_each_vma(__vmi, __vma)                                      \
     932             :         while (((__vma) = vma_next(&(__vmi))) != NULL)
     933             : 
     934             : /* The MM code likes to work with exclusive end addresses */
     935             : #define for_each_vma_range(__vmi, __vma, __end)                         \
     936             :         while (((__vma) = vma_find(&(__vmi), (__end))) != NULL)
     937             : 
     938             : #ifdef CONFIG_SHMEM
     939             : /*
     940             :  * The vma_is_shmem is not inline because it is used only by slow
     941             :  * paths in userfault.
     942             :  */
     943             : bool vma_is_shmem(struct vm_area_struct *vma);
     944             : bool vma_is_anon_shmem(struct vm_area_struct *vma);
     945             : #else
     946             : static inline bool vma_is_shmem(struct vm_area_struct *vma) { return false; }
     947             : static inline bool vma_is_anon_shmem(struct vm_area_struct *vma) { return false; }
     948             : #endif
     949             : 
     950             : int vma_is_stack_for_current(struct vm_area_struct *vma);
     951             : 
     952             : /* flush_tlb_range() takes a vma, not a mm, and can care about flags */
     953             : #define TLB_FLUSH_VMA(mm,flags) { .vm_mm = (mm), .vm_flags = (flags) }
     954             : 
     955             : struct mmu_gather;
     956             : struct inode;
     957             : 
     958             : /*
     959             :  * compound_order() can be called without holding a reference, which means
     960             :  * that niceties like page_folio() don't work.  These callers should be
     961             :  * prepared to handle wild return values.  For example, PG_head may be
     962             :  * set before _folio_order is initialised, or this may be a tail page.
     963             :  * See compaction.c for some good examples.
     964             :  */
     965   426716134 : static inline unsigned int compound_order(struct page *page)
     966             : {
     967   426716134 :         struct folio *folio = (struct folio *)page;
     968             : 
     969   426716134 :         if (!test_bit(PG_head, &folio->flags))
     970             :                 return 0;
     971    24407256 :         return folio->_folio_order;
     972             : }
     973             : 
     974             : /**
     975             :  * folio_order - The allocation order of a folio.
     976             :  * @folio: The folio.
     977             :  *
     978             :  * A folio is composed of 2^order pages.  See get_order() for the definition
     979             :  * of order.
     980             :  *
     981             :  * Return: The order of the folio.
     982             :  */
     983             : static inline unsigned int folio_order(struct folio *folio)
     984             : {
     985  1630260511 :         if (!folio_test_large(folio))
     986             :                 return 0;
     987   266979202 :         return folio->_folio_order;
     988             : }
     989             : 
     990             : #include <linux/huge_mm.h>
     991             : 
     992             : /*
     993             :  * Methods to modify the page usage count.
     994             :  *
     995             :  * What counts for a page usage:
     996             :  * - cache mapping   (page->mapping)
     997             :  * - private data    (page->private)
     998             :  * - page mapped in a task's page tables, each mapping
     999             :  *   is counted separately
    1000             :  *
    1001             :  * Also, many kernel routines increase the page count before a critical
    1002             :  * routine so they can be sure the page doesn't go away from under them.
    1003             :  */
    1004             : 
    1005             : /*
    1006             :  * Drop a ref, return true if the refcount fell to zero (the page has no users)
    1007             :  */
    1008             : static inline int put_page_testzero(struct page *page)
    1009             : {
    1010 20334331852 :         VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
    1011 20334331852 :         return page_ref_dec_and_test(page);
    1012             : }
    1013             : 
    1014             : static inline int folio_put_testzero(struct folio *folio)
    1015             : {
    1016 20334331852 :         return put_page_testzero(&folio->page);
    1017             : }
    1018             : 
    1019             : /*
    1020             :  * Try to grab a ref unless the page has a refcount of zero, return false if
    1021             :  * that is the case.
    1022             :  * This can be called when MMU is off so it must not access
    1023             :  * any of the virtual mappings.
    1024             :  */
    1025             : static inline bool get_page_unless_zero(struct page *page)
    1026             : {
    1027             :         return page_ref_add_unless(page, 1, 0);
    1028             : }
    1029             : 
    1030             : static inline struct folio *folio_get_nontail_page(struct page *page)
    1031             : {
    1032             :         if (unlikely(!get_page_unless_zero(page)))
    1033             :                 return NULL;
    1034             :         return (struct folio *)page;
    1035             : }
    1036             : 
    1037             : extern int page_is_ram(unsigned long pfn);
    1038             : 
    1039             : enum {
    1040             :         REGION_INTERSECTS,
    1041             :         REGION_DISJOINT,
    1042             :         REGION_MIXED,
    1043             : };
    1044             : 
    1045             : int region_intersects(resource_size_t offset, size_t size, unsigned long flags,
    1046             :                       unsigned long desc);
    1047             : 
    1048             : /* Support for virtually mapped pages */
    1049             : struct page *vmalloc_to_page(const void *addr);
    1050             : unsigned long vmalloc_to_pfn(const void *addr);
    1051             : 
    1052             : /*
    1053             :  * Determine if an address is within the vmalloc range
    1054             :  *
    1055             :  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
    1056             :  * is no special casing required.
    1057             :  */
    1058             : 
    1059             : #ifndef is_ioremap_addr
    1060             : #define is_ioremap_addr(x) is_vmalloc_addr(x)
    1061             : #endif
    1062             : 
    1063             : #ifdef CONFIG_MMU
    1064             : extern bool is_vmalloc_addr(const void *x);
    1065             : extern int is_vmalloc_or_module_addr(const void *x);
    1066             : #else
    1067             : static inline bool is_vmalloc_addr(const void *x)
    1068             : {
    1069             :         return false;
    1070             : }
    1071             : static inline int is_vmalloc_or_module_addr(const void *x)
    1072             : {
    1073             :         return 0;
    1074             : }
    1075             : #endif
    1076             : 
    1077             : /*
    1078             :  * How many times the entire folio is mapped as a single unit (eg by a
    1079             :  * PMD or PUD entry).  This is probably not what you want, except for
    1080             :  * debugging purposes - it does not include PTE-mapped sub-pages; look
    1081             :  * at folio_mapcount() or page_mapcount() or total_mapcount() instead.
    1082             :  */
    1083             : static inline int folio_entire_mapcount(struct folio *folio)
    1084             : {
    1085           0 :         VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
    1086           0 :         return atomic_read(&folio->_entire_mapcount) + 1;
    1087             : }
    1088             : 
    1089             : /*
    1090             :  * The atomic page->_mapcount, starts from -1: so that transitions
    1091             :  * both from it and to it can be tracked, using atomic_inc_and_test
    1092             :  * and atomic_add_negative(-1).
    1093             :  */
    1094             : static inline void page_mapcount_reset(struct page *page)
    1095             : {
    1096           0 :         atomic_set(&(page)->_mapcount, -1);
    1097             : }
    1098             : 
    1099             : /**
    1100             :  * page_mapcount() - Number of times this precise page is mapped.
    1101             :  * @page: The page.
    1102             :  *
    1103             :  * The number of times this page is mapped.  If this page is part of
    1104             :  * a large folio, it includes the number of times this page is mapped
    1105             :  * as part of that folio.
    1106             :  *
    1107             :  * The result is undefined for pages which cannot be mapped into userspace.
    1108             :  * For example SLAB or special types of pages. See function page_has_type().
    1109             :  * They use this field in struct page differently.
    1110             :  */
    1111           0 : static inline int page_mapcount(struct page *page)
    1112             : {
    1113           0 :         int mapcount = atomic_read(&page->_mapcount) + 1;
    1114             : 
    1115           0 :         if (unlikely(PageCompound(page)))
    1116           0 :                 mapcount += folio_entire_mapcount(page_folio(page));
    1117             : 
    1118           0 :         return mapcount;
    1119             : }
    1120             : 
    1121             : int folio_total_mapcount(struct folio *folio);
    1122             : 
    1123             : /**
    1124             :  * folio_mapcount() - Calculate the number of mappings of this folio.
    1125             :  * @folio: The folio.
    1126             :  *
    1127             :  * A large folio tracks both how many times the entire folio is mapped,
    1128             :  * and how many times each individual page in the folio is mapped.
    1129             :  * This function calculates the total number of times the folio is
    1130             :  * mapped.
    1131             :  *
    1132             :  * Return: The number of times this folio is mapped.
    1133             :  */
    1134             : static inline int folio_mapcount(struct folio *folio)
    1135             : {
    1136             :         if (likely(!folio_test_large(folio)))
    1137             :                 return atomic_read(&folio->_mapcount) + 1;
    1138             :         return folio_total_mapcount(folio);
    1139             : }
    1140             : 
    1141             : static inline int total_mapcount(struct page *page)
    1142             : {
    1143             :         if (likely(!PageCompound(page)))
    1144             :                 return atomic_read(&page->_mapcount) + 1;
    1145             :         return folio_total_mapcount(page_folio(page));
    1146             : }
    1147             : 
    1148             : static inline bool folio_large_is_mapped(struct folio *folio)
    1149             : {
    1150             :         /*
    1151             :          * Reading _entire_mapcount below could be omitted if hugetlb
    1152             :          * participated in incrementing nr_pages_mapped when compound mapped.
    1153             :          */
    1154    11616992 :         return atomic_read(&folio->_nr_pages_mapped) > 0 ||
    1155             :                 atomic_read(&folio->_entire_mapcount) >= 0;
    1156             : }
    1157             : 
    1158             : /**
    1159             :  * folio_mapped - Is this folio mapped into userspace?
    1160             :  * @folio: The folio.
    1161             :  *
    1162             :  * Return: True if any page in this folio is referenced by user page tables.
    1163             :  */
    1164   456775901 : static inline bool folio_mapped(struct folio *folio)
    1165             : {
    1166   456775901 :         if (likely(!folio_test_large(folio)))
    1167   445158634 :                 return atomic_read(&folio->_mapcount) >= 0;
    1168    23234259 :         return folio_large_is_mapped(folio);
    1169             : }
    1170             : 
    1171             : /*
    1172             :  * Return true if this page is mapped into pagetables.
    1173             :  * For compound page it returns true if any sub-page of compound page is mapped,
    1174             :  * even if this particular sub-page is not itself mapped by any PTE or PMD.
    1175             :  */
    1176             : static inline bool page_mapped(struct page *page)
    1177             : {
    1178             :         if (likely(!PageCompound(page)))
    1179             :                 return atomic_read(&page->_mapcount) >= 0;
    1180             :         return folio_large_is_mapped(page_folio(page));
    1181             : }
    1182             : 
    1183             : static inline struct page *virt_to_head_page(const void *x)
    1184             : {
    1185             :         struct page *page = virt_to_page(x);
    1186             : 
    1187             :         return compound_head(page);
    1188             : }
    1189             : 
    1190             : static inline struct folio *virt_to_folio(const void *x)
    1191             : {
    1192           0 :         struct page *page = virt_to_page(x);
    1193             : 
    1194           0 :         return page_folio(page);
    1195             : }
    1196             : 
    1197             : void __folio_put(struct folio *folio);
    1198             : 
    1199             : void put_pages_list(struct list_head *pages);
    1200             : 
    1201             : void split_page(struct page *page, unsigned int order);
    1202             : void folio_copy(struct folio *dst, struct folio *src);
    1203             : 
    1204             : unsigned long nr_free_buffer_pages(void);
    1205             : 
    1206             : /*
    1207             :  * Compound pages have a destructor function.  Provide a
    1208             :  * prototype for that function and accessor functions.
    1209             :  * These are _only_ valid on the head of a compound page.
    1210             :  */
    1211             : typedef void compound_page_dtor(struct page *);
    1212             : 
    1213             : /* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */
    1214             : enum compound_dtor_id {
    1215             :         NULL_COMPOUND_DTOR,
    1216             :         COMPOUND_PAGE_DTOR,
    1217             : #ifdef CONFIG_HUGETLB_PAGE
    1218             :         HUGETLB_PAGE_DTOR,
    1219             : #endif
    1220             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1221             :         TRANSHUGE_PAGE_DTOR,
    1222             : #endif
    1223             :         NR_COMPOUND_DTORS,
    1224             : };
    1225             : 
    1226             : static inline void folio_set_compound_dtor(struct folio *folio,
    1227             :                 enum compound_dtor_id compound_dtor)
    1228             : {
    1229             :         VM_BUG_ON_FOLIO(compound_dtor >= NR_COMPOUND_DTORS, folio);
    1230             :         folio->_folio_dtor = compound_dtor;
    1231             : }
    1232             : 
    1233             : void destroy_large_folio(struct folio *folio);
    1234             : 
    1235             : /* Returns the number of bytes in this potentially compound page. */
    1236             : static inline unsigned long page_size(struct page *page)
    1237             : {
    1238   213348067 :         return PAGE_SIZE << compound_order(page);
    1239             : }
    1240             : 
    1241             : /* Returns the number of bits needed for the number of bytes in a page */
    1242             : static inline unsigned int page_shift(struct page *page)
    1243             : {
    1244             :         return PAGE_SHIFT + compound_order(page);
    1245             : }
    1246             : 
    1247             : /**
    1248             :  * thp_order - Order of a transparent huge page.
    1249             :  * @page: Head page of a transparent huge page.
    1250             :  */
    1251             : static inline unsigned int thp_order(struct page *page)
    1252             : {
    1253             :         VM_BUG_ON_PGFLAGS(PageTail(page), page);
    1254             :         return compound_order(page);
    1255             : }
    1256             : 
    1257             : /**
    1258             :  * thp_size - Size of a transparent huge page.
    1259             :  * @page: Head page of a transparent huge page.
    1260             :  *
    1261             :  * Return: Number of bytes in this page.
    1262             :  */
    1263             : static inline unsigned long thp_size(struct page *page)
    1264             : {
    1265             :         return PAGE_SIZE << thp_order(page);
    1266             : }
    1267             : 
    1268             : void free_compound_page(struct page *page);
    1269             : 
    1270             : #ifdef CONFIG_MMU
    1271             : /*
    1272             :  * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
    1273             :  * servicing faults for write access.  In the normal case, do always want
    1274             :  * pte_mkwrite.  But get_user_pages can cause write faults for mappings
    1275             :  * that do not have writing enabled, when used by access_process_vm.
    1276             :  */
    1277             : static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
    1278             : {
    1279             :         if (likely(vma->vm_flags & VM_WRITE))
    1280             :                 pte = pte_mkwrite(pte);
    1281             :         return pte;
    1282             : }
    1283             : 
    1284             : vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
    1285             : void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
    1286             : 
    1287             : vm_fault_t finish_fault(struct vm_fault *vmf);
    1288             : vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
    1289             : #endif
    1290             : 
    1291             : /*
    1292             :  * Multiple processes may "see" the same page. E.g. for untouched
    1293             :  * mappings of /dev/null, all processes see the same page full of
    1294             :  * zeroes, and text pages of executables and shared libraries have
    1295             :  * only one copy in memory, at most, normally.
    1296             :  *
    1297             :  * For the non-reserved pages, page_count(page) denotes a reference count.
    1298             :  *   page_count() == 0 means the page is free. page->lru is then used for
    1299             :  *   freelist management in the buddy allocator.
    1300             :  *   page_count() > 0  means the page has been allocated.
    1301             :  *
    1302             :  * Pages are allocated by the slab allocator in order to provide memory
    1303             :  * to kmalloc and kmem_cache_alloc. In this case, the management of the
    1304             :  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
    1305             :  * unless a particular usage is carefully commented. (the responsibility of
    1306             :  * freeing the kmalloc memory is the caller's, of course).
    1307             :  *
    1308             :  * A page may be used by anyone else who does a __get_free_page().
    1309             :  * In this case, page_count still tracks the references, and should only
    1310             :  * be used through the normal accessor functions. The top bits of page->flags
    1311             :  * and page->virtual store page management information, but all other fields
    1312             :  * are unused and could be used privately, carefully. The management of this
    1313             :  * page is the responsibility of the one who allocated it, and those who have
    1314             :  * subsequently been given references to it.
    1315             :  *
    1316             :  * The other pages (we may call them "pagecache pages") are completely
    1317             :  * managed by the Linux memory manager: I/O, buffers, swapping etc.
    1318             :  * The following discussion applies only to them.
    1319             :  *
    1320             :  * A pagecache page contains an opaque `private' member, which belongs to the
    1321             :  * page's address_space. Usually, this is the address of a circular list of
    1322             :  * the page's disk buffers. PG_private must be set to tell the VM to call
    1323             :  * into the filesystem to release these pages.
    1324             :  *
    1325             :  * A page may belong to an inode's memory mapping. In this case, page->mapping
    1326             :  * is the pointer to the inode, and page->index is the file offset of the page,
    1327             :  * in units of PAGE_SIZE.
    1328             :  *
    1329             :  * If pagecache pages are not associated with an inode, they are said to be
    1330             :  * anonymous pages. These may become associated with the swapcache, and in that
    1331             :  * case PG_swapcache is set, and page->private is an offset into the swapcache.
    1332             :  *
    1333             :  * In either case (swapcache or inode backed), the pagecache itself holds one
    1334             :  * reference to the page. Setting PG_private should also increment the
    1335             :  * refcount. The each user mapping also has a reference to the page.
    1336             :  *
    1337             :  * The pagecache pages are stored in a per-mapping radix tree, which is
    1338             :  * rooted at mapping->i_pages, and indexed by offset.
    1339             :  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
    1340             :  * lists, we instead now tag pages as dirty/writeback in the radix tree.
    1341             :  *
    1342             :  * All pagecache pages may be subject to I/O:
    1343             :  * - inode pages may need to be read from disk,
    1344             :  * - inode pages which have been modified and are MAP_SHARED may need
    1345             :  *   to be written back to the inode on disk,
    1346             :  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
    1347             :  *   modified may need to be swapped out to swap space and (later) to be read
    1348             :  *   back into memory.
    1349             :  */
    1350             : 
    1351             : #if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_FS_DAX)
    1352             : DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
    1353             : 
    1354             : bool __put_devmap_managed_page_refs(struct page *page, int refs);
    1355             : static inline bool put_devmap_managed_page_refs(struct page *page, int refs)
    1356             : {
    1357             :         if (!static_branch_unlikely(&devmap_managed_key))
    1358             :                 return false;
    1359             :         if (!is_zone_device_page(page))
    1360             :                 return false;
    1361             :         return __put_devmap_managed_page_refs(page, refs);
    1362             : }
    1363             : #else /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */
    1364             : static inline bool put_devmap_managed_page_refs(struct page *page, int refs)
    1365             : {
    1366             :         return false;
    1367             : }
    1368             : #endif /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */
    1369             : 
    1370             : static inline bool put_devmap_managed_page(struct page *page)
    1371             : {
    1372             :         return put_devmap_managed_page_refs(page, 1);
    1373             : }
    1374             : 
    1375             : /* 127: arbitrary random number, small enough to assemble well */
    1376             : #define folio_ref_zero_or_close_to_overflow(folio) \
    1377             :         ((unsigned int) folio_ref_count(folio) + 127u <= 127u)
    1378             : 
    1379             : /**
    1380             :  * folio_get - Increment the reference count on a folio.
    1381             :  * @folio: The folio.
    1382             :  *
    1383             :  * Context: May be called in any context, as long as you know that
    1384             :  * you have a refcount on the folio.  If you do not already have one,
    1385             :  * folio_try_get() may be the right interface for you to use.
    1386             :  */
    1387             : static inline void folio_get(struct folio *folio)
    1388             : {
    1389 19480256523 :         VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio);
    1390 19480256523 :         folio_ref_inc(folio);
    1391             : }
    1392             : 
    1393 19240475850 : static inline void get_page(struct page *page)
    1394             : {
    1395 38480951700 :         folio_get(page_folio(page));
    1396 19238424517 : }
    1397             : 
    1398           0 : static inline __must_check bool try_get_page(struct page *page)
    1399             : {
    1400           0 :         page = compound_head(page);
    1401           0 :         if (WARN_ON_ONCE(page_ref_count(page) <= 0))
    1402             :                 return false;
    1403           0 :         page_ref_inc(page);
    1404           0 :         return true;
    1405             : }
    1406             : 
    1407             : /**
    1408             :  * folio_put - Decrement the reference count on a folio.
    1409             :  * @folio: The folio.
    1410             :  *
    1411             :  * If the folio's reference count reaches zero, the memory will be
    1412             :  * released back to the page allocator and may be used by another
    1413             :  * allocation immediately.  Do not access the memory or the struct folio
    1414             :  * after calling folio_put() unless you can be sure that it wasn't the
    1415             :  * last reference.
    1416             :  *
    1417             :  * Context: May be called in process or interrupt context, but not in NMI
    1418             :  * context.  May be called while holding a spinlock.
    1419             :  */
    1420 20334331852 : static inline void folio_put(struct folio *folio)
    1421             : {
    1422 20334331852 :         if (folio_put_testzero(folio))
    1423     1901384 :                 __folio_put(folio);
    1424 20340106831 : }
    1425             : 
    1426             : /**
    1427             :  * folio_put_refs - Reduce the reference count on a folio.
    1428             :  * @folio: The folio.
    1429             :  * @refs: The amount to subtract from the folio's reference count.
    1430             :  *
    1431             :  * If the folio's reference count reaches zero, the memory will be
    1432             :  * released back to the page allocator and may be used by another
    1433             :  * allocation immediately.  Do not access the memory or the struct folio
    1434             :  * after calling folio_put_refs() unless you can be sure that these weren't
    1435             :  * the last references.
    1436             :  *
    1437             :  * Context: May be called in process or interrupt context, but not in NMI
    1438             :  * context.  May be called while holding a spinlock.
    1439             :  */
    1440   203595129 : static inline void folio_put_refs(struct folio *folio, int refs)
    1441             : {
    1442   203595129 :         if (folio_ref_sub_and_test(folio, refs))
    1443           0 :                 __folio_put(folio);
    1444   203596517 : }
    1445             : 
    1446             : /*
    1447             :  * union release_pages_arg - an array of pages or folios
    1448             :  *
    1449             :  * release_pages() releases a simple array of multiple pages, and
    1450             :  * accepts various different forms of said page array: either
    1451             :  * a regular old boring array of pages, an array of folios, or
    1452             :  * an array of encoded page pointers.
    1453             :  *
    1454             :  * The transparent union syntax for this kind of "any of these
    1455             :  * argument types" is all kinds of ugly, so look away.
    1456             :  */
    1457             : typedef union {
    1458             :         struct page **pages;
    1459             :         struct folio **folios;
    1460             :         struct encoded_page **encoded_pages;
    1461             : } release_pages_arg __attribute__ ((__transparent_union__));
    1462             : 
    1463             : void release_pages(release_pages_arg, int nr);
    1464             : 
    1465             : /**
    1466             :  * folios_put - Decrement the reference count on an array of folios.
    1467             :  * @folios: The folios.
    1468             :  * @nr: How many folios there are.
    1469             :  *
    1470             :  * Like folio_put(), but for an array of folios.  This is more efficient
    1471             :  * than writing the loop yourself as it will optimise the locks which
    1472             :  * need to be taken if the folios are freed.
    1473             :  *
    1474             :  * Context: May be called in process or interrupt context, but not in NMI
    1475             :  * context.  May be called while holding a spinlock.
    1476             :  */
    1477             : static inline void folios_put(struct folio **folios, unsigned int nr)
    1478             : {
    1479             :         release_pages(folios, nr);
    1480             : }
    1481             : 
    1482 19435744438 : static inline void put_page(struct page *page)
    1483             : {
    1484 19435744438 :         struct folio *folio = page_folio(page);
    1485             : 
    1486             :         /*
    1487             :          * For some devmap managed pages we need to catch refcount transition
    1488             :          * from 2 to 1:
    1489             :          */
    1490 19435744438 :         if (put_devmap_managed_page(&folio->page))
    1491             :                 return;
    1492 19435744438 :         folio_put(folio);
    1493             : }
    1494             : 
    1495             : /*
    1496             :  * GUP_PIN_COUNTING_BIAS, and the associated functions that use it, overload
    1497             :  * the page's refcount so that two separate items are tracked: the original page
    1498             :  * reference count, and also a new count of how many pin_user_pages() calls were
    1499             :  * made against the page. ("gup-pinned" is another term for the latter).
    1500             :  *
    1501             :  * With this scheme, pin_user_pages() becomes special: such pages are marked as
    1502             :  * distinct from normal pages. As such, the unpin_user_page() call (and its
    1503             :  * variants) must be used in order to release gup-pinned pages.
    1504             :  *
    1505             :  * Choice of value:
    1506             :  *
    1507             :  * By making GUP_PIN_COUNTING_BIAS a power of two, debugging of page reference
    1508             :  * counts with respect to pin_user_pages() and unpin_user_page() becomes
    1509             :  * simpler, due to the fact that adding an even power of two to the page
    1510             :  * refcount has the effect of using only the upper N bits, for the code that
    1511             :  * counts up using the bias value. This means that the lower bits are left for
    1512             :  * the exclusive use of the original code that increments and decrements by one
    1513             :  * (or at least, by much smaller values than the bias value).
    1514             :  *
    1515             :  * Of course, once the lower bits overflow into the upper bits (and this is
    1516             :  * OK, because subtraction recovers the original values), then visual inspection
    1517             :  * no longer suffices to directly view the separate counts. However, for normal
    1518             :  * applications that don't have huge page reference counts, this won't be an
    1519             :  * issue.
    1520             :  *
    1521             :  * Locking: the lockless algorithm described in folio_try_get_rcu()
    1522             :  * provides safe operation for get_user_pages(), page_mkclean() and
    1523             :  * other calls that race to set up page table entries.
    1524             :  */
    1525             : #define GUP_PIN_COUNTING_BIAS (1U << 10)
    1526             : 
    1527             : void unpin_user_page(struct page *page);
    1528             : void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
    1529             :                                  bool make_dirty);
    1530             : void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
    1531             :                                       bool make_dirty);
    1532             : void unpin_user_pages(struct page **pages, unsigned long npages);
    1533             : 
    1534             : static inline bool is_cow_mapping(vm_flags_t flags)
    1535             : {
    1536             :         return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
    1537             : }
    1538             : 
    1539             : #ifndef CONFIG_MMU
    1540             : static inline bool is_nommu_shared_mapping(vm_flags_t flags)
    1541             : {
    1542             :         /*
    1543             :          * NOMMU shared mappings are ordinary MAP_SHARED mappings and selected
    1544             :          * R/O MAP_PRIVATE file mappings that are an effective R/O overlay of
    1545             :          * a file mapping. R/O MAP_PRIVATE mappings might still modify
    1546             :          * underlying memory if ptrace is active, so this is only possible if
    1547             :          * ptrace does not apply. Note that there is no mprotect() to upgrade
    1548             :          * write permissions later.
    1549             :          */
    1550             :         return flags & (VM_MAYSHARE | VM_MAYOVERLAY);
    1551             : }
    1552             : #endif
    1553             : 
    1554             : #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
    1555             : #define SECTION_IN_PAGE_FLAGS
    1556             : #endif
    1557             : 
    1558             : /*
    1559             :  * The identification function is mainly used by the buddy allocator for
    1560             :  * determining if two pages could be buddies. We are not really identifying
    1561             :  * the zone since we could be using the section number id if we do not have
    1562             :  * node id available in page flags.
    1563             :  * We only guarantee that it will return the same value for two combinable
    1564             :  * pages in a zone.
    1565             :  */
    1566             : static inline int page_zone_id(struct page *page)
    1567             : {
    1568             :         return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
    1569             : }
    1570             : 
    1571             : #ifdef NODE_NOT_IN_PAGE_FLAGS
    1572             : extern int page_to_nid(const struct page *page);
    1573             : #else
    1574             : static inline int page_to_nid(const struct page *page)
    1575             : {
    1576   323450719 :         struct page *p = (struct page *)page;
    1577             : 
    1578   323450719 :         return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK;
    1579             : }
    1580             : #endif
    1581             : 
    1582             : static inline int folio_nid(const struct folio *folio)
    1583             : {
    1584             :         return page_to_nid(&folio->page);
    1585             : }
    1586             : 
    1587             : #ifdef CONFIG_NUMA_BALANCING
    1588             : /* page access time bits needs to hold at least 4 seconds */
    1589             : #define PAGE_ACCESS_TIME_MIN_BITS       12
    1590             : #if LAST_CPUPID_SHIFT < PAGE_ACCESS_TIME_MIN_BITS
    1591             : #define PAGE_ACCESS_TIME_BUCKETS                                \
    1592             :         (PAGE_ACCESS_TIME_MIN_BITS - LAST_CPUPID_SHIFT)
    1593             : #else
    1594             : #define PAGE_ACCESS_TIME_BUCKETS        0
    1595             : #endif
    1596             : 
    1597             : #define PAGE_ACCESS_TIME_MASK                           \
    1598             :         (LAST_CPUPID_MASK << PAGE_ACCESS_TIME_BUCKETS)
    1599             : 
    1600             : static inline int cpu_pid_to_cpupid(int cpu, int pid)
    1601             : {
    1602             :         return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
    1603             : }
    1604             : 
    1605             : static inline int cpupid_to_pid(int cpupid)
    1606             : {
    1607             :         return cpupid & LAST__PID_MASK;
    1608             : }
    1609             : 
    1610             : static inline int cpupid_to_cpu(int cpupid)
    1611             : {
    1612             :         return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
    1613             : }
    1614             : 
    1615             : static inline int cpupid_to_nid(int cpupid)
    1616             : {
    1617             :         return cpu_to_node(cpupid_to_cpu(cpupid));
    1618             : }
    1619             : 
    1620             : static inline bool cpupid_pid_unset(int cpupid)
    1621             : {
    1622             :         return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
    1623             : }
    1624             : 
    1625             : static inline bool cpupid_cpu_unset(int cpupid)
    1626             : {
    1627             :         return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
    1628             : }
    1629             : 
    1630             : static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
    1631             : {
    1632             :         return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
    1633             : }
    1634             : 
    1635             : #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
    1636             : #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
    1637             : static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
    1638             : {
    1639             :         return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
    1640             : }
    1641             : 
    1642             : static inline int page_cpupid_last(struct page *page)
    1643             : {
    1644             :         return page->_last_cpupid;
    1645             : }
    1646             : static inline void page_cpupid_reset_last(struct page *page)
    1647             : {
    1648             :         page->_last_cpupid = -1 & LAST_CPUPID_MASK;
    1649             : }
    1650             : #else
    1651             : static inline int page_cpupid_last(struct page *page)
    1652             : {
    1653             :         return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
    1654             : }
    1655             : 
    1656             : extern int page_cpupid_xchg_last(struct page *page, int cpupid);
    1657             : 
    1658             : static inline void page_cpupid_reset_last(struct page *page)
    1659             : {
    1660             :         page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
    1661             : }
    1662             : #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
    1663             : 
    1664             : static inline int xchg_page_access_time(struct page *page, int time)
    1665             : {
    1666             :         int last_time;
    1667             : 
    1668             :         last_time = page_cpupid_xchg_last(page, time >> PAGE_ACCESS_TIME_BUCKETS);
    1669             :         return last_time << PAGE_ACCESS_TIME_BUCKETS;
    1670             : }
    1671             : 
    1672             : static inline void vma_set_access_pid_bit(struct vm_area_struct *vma)
    1673             : {
    1674             :         unsigned int pid_bit;
    1675             : 
    1676             :         pid_bit = hash_32(current->pid, ilog2(BITS_PER_LONG));
    1677             :         if (vma->numab_state && !test_bit(pid_bit, &vma->numab_state->access_pids[1])) {
    1678             :                 __set_bit(pid_bit, &vma->numab_state->access_pids[1]);
    1679             :         }
    1680             : }
    1681             : #else /* !CONFIG_NUMA_BALANCING */
    1682             : static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
    1683             : {
    1684             :         return page_to_nid(page); /* XXX */
    1685             : }
    1686             : 
    1687             : static inline int xchg_page_access_time(struct page *page, int time)
    1688             : {
    1689             :         return 0;
    1690             : }
    1691             : 
    1692             : static inline int page_cpupid_last(struct page *page)
    1693             : {
    1694             :         return page_to_nid(page); /* XXX */
    1695             : }
    1696             : 
    1697             : static inline int cpupid_to_nid(int cpupid)
    1698             : {
    1699             :         return -1;
    1700             : }
    1701             : 
    1702             : static inline int cpupid_to_pid(int cpupid)
    1703             : {
    1704             :         return -1;
    1705             : }
    1706             : 
    1707             : static inline int cpupid_to_cpu(int cpupid)
    1708             : {
    1709             :         return -1;
    1710             : }
    1711             : 
    1712             : static inline int cpu_pid_to_cpupid(int nid, int pid)
    1713             : {
    1714             :         return -1;
    1715             : }
    1716             : 
    1717             : static inline bool cpupid_pid_unset(int cpupid)
    1718             : {
    1719             :         return true;
    1720             : }
    1721             : 
    1722             : static inline void page_cpupid_reset_last(struct page *page)
    1723             : {
    1724             : }
    1725             : 
    1726             : static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
    1727             : {
    1728             :         return false;
    1729             : }
    1730             : 
    1731             : static inline void vma_set_access_pid_bit(struct vm_area_struct *vma)
    1732             : {
    1733             : }
    1734             : #endif /* CONFIG_NUMA_BALANCING */
    1735             : 
    1736             : #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
    1737             : 
    1738             : /*
    1739             :  * KASAN per-page tags are stored xor'ed with 0xff. This allows to avoid
    1740             :  * setting tags for all pages to native kernel tag value 0xff, as the default
    1741             :  * value 0x00 maps to 0xff.
    1742             :  */
    1743             : 
    1744             : static inline u8 page_kasan_tag(const struct page *page)
    1745             : {
    1746             :         u8 tag = 0xff;
    1747             : 
    1748             :         if (kasan_enabled()) {
    1749             :                 tag = (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
    1750             :                 tag ^= 0xff;
    1751             :         }
    1752             : 
    1753             :         return tag;
    1754             : }
    1755             : 
    1756             : static inline void page_kasan_tag_set(struct page *page, u8 tag)
    1757             : {
    1758             :         unsigned long old_flags, flags;
    1759             : 
    1760             :         if (!kasan_enabled())
    1761             :                 return;
    1762             : 
    1763             :         tag ^= 0xff;
    1764             :         old_flags = READ_ONCE(page->flags);
    1765             :         do {
    1766             :                 flags = old_flags;
    1767             :                 flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
    1768             :                 flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
    1769             :         } while (unlikely(!try_cmpxchg(&page->flags, &old_flags, flags)));
    1770             : }
    1771             : 
    1772             : static inline void page_kasan_tag_reset(struct page *page)
    1773             : {
    1774             :         if (kasan_enabled())
    1775             :                 page_kasan_tag_set(page, 0xff);
    1776             : }
    1777             : 
    1778             : #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
    1779             : 
    1780             : static inline u8 page_kasan_tag(const struct page *page)
    1781             : {
    1782             :         return 0xff;
    1783             : }
    1784             : 
    1785             : static inline void page_kasan_tag_set(struct page *page, u8 tag) { }
    1786             : static inline void page_kasan_tag_reset(struct page *page) { }
    1787             : 
    1788             : #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
    1789             : 
    1790             : static inline struct zone *page_zone(const struct page *page)
    1791             : {
    1792   185568896 :         return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
    1793             : }
    1794             : 
    1795             : static inline pg_data_t *page_pgdat(const struct page *page)
    1796             : {
    1797   137881823 :         return NODE_DATA(page_to_nid(page));
    1798             : }
    1799             : 
    1800             : static inline struct zone *folio_zone(const struct folio *folio)
    1801             : {
    1802   185568896 :         return page_zone(&folio->page);
    1803             : }
    1804             : 
    1805             : static inline pg_data_t *folio_pgdat(const struct folio *folio)
    1806             : {
    1807   137881823 :         return page_pgdat(&folio->page);
    1808             : }
    1809             : 
    1810             : #ifdef SECTION_IN_PAGE_FLAGS
    1811             : static inline void set_page_section(struct page *page, unsigned long section)
    1812             : {
    1813             :         page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
    1814             :         page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
    1815             : }
    1816             : 
    1817             : static inline unsigned long page_to_section(const struct page *page)
    1818             : {
    1819             :         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
    1820             : }
    1821             : #endif
    1822             : 
    1823             : /**
    1824             :  * folio_pfn - Return the Page Frame Number of a folio.
    1825             :  * @folio: The folio.
    1826             :  *
    1827             :  * A folio may contain multiple pages.  The pages have consecutive
    1828             :  * Page Frame Numbers.
    1829             :  *
    1830             :  * Return: The Page Frame Number of the first page in the folio.
    1831             :  */
    1832             : static inline unsigned long folio_pfn(struct folio *folio)
    1833             : {
    1834           0 :         return page_to_pfn(&folio->page);
    1835             : }
    1836             : 
    1837             : static inline struct folio *pfn_folio(unsigned long pfn)
    1838             : {
    1839             :         return page_folio(pfn_to_page(pfn));
    1840             : }
    1841             : 
    1842             : /**
    1843             :  * folio_maybe_dma_pinned - Report if a folio may be pinned for DMA.
    1844             :  * @folio: The folio.
    1845             :  *
    1846             :  * This function checks if a folio has been pinned via a call to
    1847             :  * a function in the pin_user_pages() family.
    1848             :  *
    1849             :  * For small folios, the return value is partially fuzzy: false is not fuzzy,
    1850             :  * because it means "definitely not pinned for DMA", but true means "probably
    1851             :  * pinned for DMA, but possibly a false positive due to having at least
    1852             :  * GUP_PIN_COUNTING_BIAS worth of normal folio references".
    1853             :  *
    1854             :  * False positives are OK, because: a) it's unlikely for a folio to
    1855             :  * get that many refcounts, and b) all the callers of this routine are
    1856             :  * expected to be able to deal gracefully with a false positive.
    1857             :  *
    1858             :  * For large folios, the result will be exactly correct. That's because
    1859             :  * we have more tracking data available: the _pincount field is used
    1860             :  * instead of the GUP_PIN_COUNTING_BIAS scheme.
    1861             :  *
    1862             :  * For more information, please see Documentation/core-api/pin_user_pages.rst.
    1863             :  *
    1864             :  * Return: True, if it is likely that the page has been "dma-pinned".
    1865             :  * False, if the page is definitely not dma-pinned.
    1866             :  */
    1867             : static inline bool folio_maybe_dma_pinned(struct folio *folio)
    1868             : {
    1869           0 :         if (folio_test_large(folio))
    1870           0 :                 return atomic_read(&folio->_pincount) > 0;
    1871             : 
    1872             :         /*
    1873             :          * folio_ref_count() is signed. If that refcount overflows, then
    1874             :          * folio_ref_count() returns a negative value, and callers will avoid
    1875             :          * further incrementing the refcount.
    1876             :          *
    1877             :          * Here, for that overflow case, use the sign bit to count a little
    1878             :          * bit higher via unsigned math, and thus still get an accurate result.
    1879             :          */
    1880           0 :         return ((unsigned int)folio_ref_count(folio)) >=
    1881             :                 GUP_PIN_COUNTING_BIAS;
    1882             : }
    1883             : 
    1884             : static inline bool page_maybe_dma_pinned(struct page *page)
    1885             : {
    1886             :         return folio_maybe_dma_pinned(page_folio(page));
    1887             : }
    1888             : 
    1889             : /*
    1890             :  * This should most likely only be called during fork() to see whether we
    1891             :  * should break the cow immediately for an anon page on the src mm.
    1892             :  *
    1893             :  * The caller has to hold the PT lock and the vma->vm_mm->->write_protect_seq.
    1894             :  */
    1895             : static inline bool page_needs_cow_for_dma(struct vm_area_struct *vma,
    1896             :                                           struct page *page)
    1897             : {
    1898             :         VM_BUG_ON(!(raw_read_seqcount(&vma->vm_mm->write_protect_seq) & 1));
    1899             : 
    1900             :         if (!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))
    1901             :                 return false;
    1902             : 
    1903             :         return page_maybe_dma_pinned(page);
    1904             : }
    1905             : 
    1906             : /**
    1907             :  * is_zero_page - Query if a page is a zero page
    1908             :  * @page: The page to query
    1909             :  *
    1910             :  * This returns true if @page is one of the permanent zero pages.
    1911             :  */
    1912             : static inline bool is_zero_page(const struct page *page)
    1913             : {
    1914             :         return is_zero_pfn(page_to_pfn(page));
    1915             : }
    1916             : 
    1917             : /**
    1918             :  * is_zero_folio - Query if a folio is a zero page
    1919             :  * @folio: The folio to query
    1920             :  *
    1921             :  * This returns true if @folio is one of the permanent zero pages.
    1922             :  */
    1923             : static inline bool is_zero_folio(const struct folio *folio)
    1924             : {
    1925             :         return is_zero_page(&folio->page);
    1926             : }
    1927             : 
    1928             : /* MIGRATE_CMA and ZONE_MOVABLE do not allow pin folios */
    1929             : #ifdef CONFIG_MIGRATION
    1930             : static inline bool folio_is_longterm_pinnable(struct folio *folio)
    1931             : {
    1932             : #ifdef CONFIG_CMA
    1933             :         int mt = folio_migratetype(folio);
    1934             : 
    1935             :         if (mt == MIGRATE_CMA || mt == MIGRATE_ISOLATE)
    1936             :                 return false;
    1937             : #endif
    1938             :         /* The zero page can be "pinned" but gets special handling. */
    1939             :         if (is_zero_folio(folio))
    1940             :                 return true;
    1941             : 
    1942             :         /* Coherent device memory must always allow eviction. */
    1943             :         if (folio_is_device_coherent(folio))
    1944             :                 return false;
    1945             : 
    1946             :         /* Otherwise, non-movable zone folios can be pinned. */
    1947             :         return !folio_is_zone_movable(folio);
    1948             : 
    1949             : }
    1950             : #else
    1951             : static inline bool folio_is_longterm_pinnable(struct folio *folio)
    1952             : {
    1953             :         return true;
    1954             : }
    1955             : #endif
    1956             : 
    1957             : static inline void set_page_zone(struct page *page, enum zone_type zone)
    1958             : {
    1959             :         page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
    1960             :         page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
    1961             : }
    1962             : 
    1963             : static inline void set_page_node(struct page *page, unsigned long node)
    1964             : {
    1965             :         page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
    1966             :         page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
    1967             : }
    1968             : 
    1969             : static inline void set_page_links(struct page *page, enum zone_type zone,
    1970             :         unsigned long node, unsigned long pfn)
    1971             : {
    1972             :         set_page_zone(page, zone);
    1973             :         set_page_node(page, node);
    1974             : #ifdef SECTION_IN_PAGE_FLAGS
    1975             :         set_page_section(page, pfn_to_section_nr(pfn));
    1976             : #endif
    1977             : }
    1978             : 
    1979             : /**
    1980             :  * folio_nr_pages - The number of pages in the folio.
    1981             :  * @folio: The folio.
    1982             :  *
    1983             :  * Return: A positive power of two.
    1984             :  */
    1985             : static inline long folio_nr_pages(struct folio *folio)
    1986             : {
    1987  2623812757 :         if (!folio_test_large(folio))
    1988             :                 return 1;
    1989             : #ifdef CONFIG_64BIT
    1990    85468772 :         return folio->_folio_nr_pages;
    1991             : #else
    1992             :         return 1L << folio->_folio_order;
    1993             : #endif
    1994             : }
    1995             : 
    1996             : /*
    1997             :  * compound_nr() returns the number of pages in this potentially compound
    1998             :  * page.  compound_nr() can be called on a tail page, and is defined to
    1999             :  * return 1 in that case.
    2000             :  */
    2001   476458180 : static inline unsigned long compound_nr(struct page *page)
    2002             : {
    2003   476458180 :         struct folio *folio = (struct folio *)page;
    2004             : 
    2005   476458180 :         if (!test_bit(PG_head, &folio->flags))
    2006             :                 return 1;
    2007             : #ifdef CONFIG_64BIT
    2008    74205394 :         return folio->_folio_nr_pages;
    2009             : #else
    2010             :         return 1L << folio->_folio_order;
    2011             : #endif
    2012             : }
    2013             : 
    2014             : /**
    2015             :  * thp_nr_pages - The number of regular pages in this huge page.
    2016             :  * @page: The head page of a huge page.
    2017             :  */
    2018             : static inline int thp_nr_pages(struct page *page)
    2019             : {
    2020           0 :         return folio_nr_pages((struct folio *)page);
    2021             : }
    2022             : 
    2023             : /**
    2024             :  * folio_next - Move to the next physical folio.
    2025             :  * @folio: The folio we're currently operating on.
    2026             :  *
    2027             :  * If you have physically contiguous memory which may span more than
    2028             :  * one folio (eg a &struct bio_vec), use this function to move from one
    2029             :  * folio to the next.  Do not use it if the memory is only virtually
    2030             :  * contiguous as the folios are almost certainly not adjacent to each
    2031             :  * other.  This is the folio equivalent to writing ``page++``.
    2032             :  *
    2033             :  * Context: We assume that the folios are refcounted and/or locked at a
    2034             :  * higher level and do not adjust the reference counts.
    2035             :  * Return: The next struct folio.
    2036             :  */
    2037             : static inline struct folio *folio_next(struct folio *folio)
    2038             : {
    2039    62191113 :         return (struct folio *)folio_page(folio, folio_nr_pages(folio));
    2040             : }
    2041             : 
    2042             : /**
    2043             :  * folio_shift - The size of the memory described by this folio.
    2044             :  * @folio: The folio.
    2045             :  *
    2046             :  * A folio represents a number of bytes which is a power-of-two in size.
    2047             :  * This function tells you which power-of-two the folio is.  See also
    2048             :  * folio_size() and folio_order().
    2049             :  *
    2050             :  * Context: The caller should have a reference on the folio to prevent
    2051             :  * it from being split.  It is not necessary for the folio to be locked.
    2052             :  * Return: The base-2 logarithm of the size of this folio.
    2053             :  */
    2054             : static inline unsigned int folio_shift(struct folio *folio)
    2055             : {
    2056   244709473 :         return PAGE_SHIFT + folio_order(folio);
    2057             : }
    2058             : 
    2059             : /**
    2060             :  * folio_size - The number of bytes in a folio.
    2061             :  * @folio: The folio.
    2062             :  *
    2063             :  * Context: The caller should have a reference on the folio to prevent
    2064             :  * it from being split.  It is not necessary for the folio to be locked.
    2065             :  * Return: The number of bytes in this folio.
    2066             :  */
    2067             : static inline size_t folio_size(struct folio *folio)
    2068             : {
    2069  3337801122 :         return PAGE_SIZE << folio_order(folio);
    2070             : }
    2071             : 
    2072             : /**
    2073             :  * folio_estimated_sharers - Estimate the number of sharers of a folio.
    2074             :  * @folio: The folio.
    2075             :  *
    2076             :  * folio_estimated_sharers() aims to serve as a function to efficiently
    2077             :  * estimate the number of processes sharing a folio. This is done by
    2078             :  * looking at the precise mapcount of the first subpage in the folio, and
    2079             :  * assuming the other subpages are the same. This may not be true for large
    2080             :  * folios. If you want exact mapcounts for exact calculations, look at
    2081             :  * page_mapcount() or folio_total_mapcount().
    2082             :  *
    2083             :  * Return: The estimated number of processes sharing a folio.
    2084             :  */
    2085             : static inline int folio_estimated_sharers(struct folio *folio)
    2086             : {
    2087             :         return page_mapcount(folio_page(folio, 0));
    2088             : }
    2089             : 
    2090             : #ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
    2091             : static inline int arch_make_page_accessible(struct page *page)
    2092             : {
    2093             :         return 0;
    2094             : }
    2095             : #endif
    2096             : 
    2097             : #ifndef HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
    2098             : static inline int arch_make_folio_accessible(struct folio *folio)
    2099             : {
    2100    45128497 :         int ret;
    2101    45128497 :         long i, nr = folio_nr_pages(folio);
    2102             : 
    2103    45128497 :         for (i = 0; i < nr; i++) {
    2104             :                 ret = arch_make_page_accessible(folio_page(folio, i));
    2105             :                 if (ret)
    2106             :                         break;
    2107             :         }
    2108             : 
    2109    45128497 :         return ret;
    2110             : }
    2111             : #endif
    2112             : 
    2113             : /*
    2114             :  * Some inline functions in vmstat.h depend on page_zone()
    2115             :  */
    2116             : #include <linux/vmstat.h>
    2117             : 
    2118             : static __always_inline void *lowmem_page_address(const struct page *page)
    2119             : {
    2120 19695923736 :         return page_to_virt(page);
    2121             : }
    2122             : 
    2123             : #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
    2124             : #define HASHED_PAGE_VIRTUAL
    2125             : #endif
    2126             : 
    2127             : #if defined(WANT_PAGE_VIRTUAL)
    2128             : static inline void *page_address(const struct page *page)
    2129             : {
    2130             :         return page->virtual;
    2131             : }
    2132             : static inline void set_page_address(struct page *page, void *address)
    2133             : {
    2134             :         page->virtual = address;
    2135             : }
    2136             : #define page_address_init()  do { } while(0)
    2137             : #endif
    2138             : 
    2139             : #if defined(HASHED_PAGE_VIRTUAL)
    2140             : void *page_address(const struct page *page);
    2141             : void set_page_address(struct page *page, void *virtual);
    2142             : void page_address_init(void);
    2143             : #endif
    2144             : 
    2145             : #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
    2146             : #define page_address(page) lowmem_page_address(page)
    2147             : #define set_page_address(page, address)  do { } while(0)
    2148             : #define page_address_init()  do { } while(0)
    2149             : #endif
    2150             : 
    2151             : static inline void *folio_address(const struct folio *folio)
    2152             : {
    2153      360288 :         return page_address(&folio->page);
    2154             : }
    2155             : 
    2156             : extern void *page_rmapping(struct page *page);
    2157             : extern pgoff_t __page_file_index(struct page *page);
    2158             : 
    2159             : /*
    2160             :  * Return the pagecache index of the passed page.  Regular pagecache pages
    2161             :  * use ->index whereas swapcache pages use swp_offset(->private)
    2162             :  */
    2163           0 : static inline pgoff_t page_index(struct page *page)
    2164             : {
    2165           0 :         if (unlikely(PageSwapCache(page)))
    2166           0 :                 return __page_file_index(page);
    2167           0 :         return page->index;
    2168             : }
    2169             : 
    2170             : /*
    2171             :  * Return true only if the page has been allocated with
    2172             :  * ALLOC_NO_WATERMARKS and the low watermark was not
    2173             :  * met implying that the system is under some pressure.
    2174             :  */
    2175             : static inline bool page_is_pfmemalloc(const struct page *page)
    2176             : {
    2177             :         /*
    2178             :          * lru.next has bit 1 set if the page is allocated from the
    2179             :          * pfmemalloc reserves.  Callers may simply overwrite it if
    2180             :          * they do not need to preserve that information.
    2181             :          */
    2182             :         return (uintptr_t)page->lru.next & BIT(1);
    2183             : }
    2184             : 
    2185             : /*
    2186             :  * Return true only if the folio has been allocated with
    2187             :  * ALLOC_NO_WATERMARKS and the low watermark was not
    2188             :  * met implying that the system is under some pressure.
    2189             :  */
    2190             : static inline bool folio_is_pfmemalloc(const struct folio *folio)
    2191             : {
    2192             :         /*
    2193             :          * lru.next has bit 1 set if the page is allocated from the
    2194             :          * pfmemalloc reserves.  Callers may simply overwrite it if
    2195             :          * they do not need to preserve that information.
    2196             :          */
    2197             :         return (uintptr_t)folio->lru.next & BIT(1);
    2198             : }
    2199             : 
    2200             : /*
    2201             :  * Only to be called by the page allocator on a freshly allocated
    2202             :  * page.
    2203             :  */
    2204             : static inline void set_page_pfmemalloc(struct page *page)
    2205             : {
    2206             :         page->lru.next = (void *)BIT(1);
    2207             : }
    2208             : 
    2209             : static inline void clear_page_pfmemalloc(struct page *page)
    2210             : {
    2211             :         page->lru.next = NULL;
    2212             : }
    2213             : 
    2214             : /*
    2215             :  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
    2216             :  */
    2217             : extern void pagefault_out_of_memory(void);
    2218             : 
    2219             : #define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
    2220             : #define offset_in_thp(page, p)  ((unsigned long)(p) & (thp_size(page) - 1))
    2221             : #define offset_in_folio(folio, p) ((unsigned long)(p) & (folio_size(folio) - 1))
    2222             : 
    2223             : /*
    2224             :  * Flags passed to show_mem() and show_free_areas() to suppress output in
    2225             :  * various contexts.
    2226             :  */
    2227             : #define SHOW_MEM_FILTER_NODES           (0x0001u)       /* disallowed nodes */
    2228             : 
    2229             : extern void __show_free_areas(unsigned int flags, nodemask_t *nodemask, int max_zone_idx);
    2230             : static void __maybe_unused show_free_areas(unsigned int flags, nodemask_t *nodemask)
    2231             : {
    2232             :         __show_free_areas(flags, nodemask, MAX_NR_ZONES - 1);
    2233             : }
    2234             : 
    2235             : /*
    2236             :  * Parameter block passed down to zap_pte_range in exceptional cases.
    2237             :  */
    2238             : struct zap_details {
    2239             :         struct folio *single_folio;     /* Locked folio to be unmapped */
    2240             :         bool even_cows;                 /* Zap COWed private pages too? */
    2241             :         zap_flags_t zap_flags;          /* Extra flags for zapping */
    2242             : };
    2243             : 
    2244             : /*
    2245             :  * Whether to drop the pte markers, for example, the uffd-wp information for
    2246             :  * file-backed memory.  This should only be specified when we will completely
    2247             :  * drop the page in the mm, either by truncation or unmapping of the vma.  By
    2248             :  * default, the flag is not set.
    2249             :  */
    2250             : #define  ZAP_FLAG_DROP_MARKER        ((__force zap_flags_t) BIT(0))
    2251             : /* Set in unmap_vmas() to indicate a final unmap call.  Only used by hugetlb */
    2252             : #define  ZAP_FLAG_UNMAP              ((__force zap_flags_t) BIT(1))
    2253             : 
    2254             : #ifdef CONFIG_SCHED_MM_CID
    2255             : void sched_mm_cid_before_execve(struct task_struct *t);
    2256             : void sched_mm_cid_after_execve(struct task_struct *t);
    2257             : void sched_mm_cid_fork(struct task_struct *t);
    2258             : void sched_mm_cid_exit_signals(struct task_struct *t);
    2259             : static inline int task_mm_cid(struct task_struct *t)
    2260             : {
    2261             :         return t->mm_cid;
    2262             : }
    2263             : #else
    2264             : static inline void sched_mm_cid_before_execve(struct task_struct *t) { }
    2265             : static inline void sched_mm_cid_after_execve(struct task_struct *t) { }
    2266             : static inline void sched_mm_cid_fork(struct task_struct *t) { }
    2267             : static inline void sched_mm_cid_exit_signals(struct task_struct *t) { }
    2268             : static inline int task_mm_cid(struct task_struct *t)
    2269             : {
    2270             :         /*
    2271             :          * Use the processor id as a fall-back when the mm cid feature is
    2272             :          * disabled. This provides functional per-cpu data structure accesses
    2273             :          * in user-space, althrough it won't provide the memory usage benefits.
    2274             :          */
    2275             :         return raw_smp_processor_id();
    2276             : }
    2277             : #endif
    2278             : 
    2279             : #ifdef CONFIG_MMU
    2280             : extern bool can_do_mlock(void);
    2281             : #else
    2282             : static inline bool can_do_mlock(void) { return false; }
    2283             : #endif
    2284             : extern int user_shm_lock(size_t, struct ucounts *);
    2285             : extern void user_shm_unlock(size_t, struct ucounts *);
    2286             : 
    2287             : struct folio *vm_normal_folio(struct vm_area_struct *vma, unsigned long addr,
    2288             :                              pte_t pte);
    2289             : struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
    2290             :                              pte_t pte);
    2291             : struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
    2292             :                                 pmd_t pmd);
    2293             : 
    2294             : void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
    2295             :                   unsigned long size);
    2296             : void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
    2297             :                            unsigned long size, struct zap_details *details);
    2298             : static inline void zap_vma_pages(struct vm_area_struct *vma)
    2299             : {
    2300             :         zap_page_range_single(vma, vma->vm_start,
    2301             :                               vma->vm_end - vma->vm_start, NULL);
    2302             : }
    2303             : void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt,
    2304             :                 struct vm_area_struct *start_vma, unsigned long start,
    2305             :                 unsigned long end, bool mm_wr_locked);
    2306             : 
    2307             : struct mmu_notifier_range;
    2308             : 
    2309             : void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
    2310             :                 unsigned long end, unsigned long floor, unsigned long ceiling);
    2311             : int
    2312             : copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
    2313             : int follow_pte(struct mm_struct *mm, unsigned long address,
    2314             :                pte_t **ptepp, spinlock_t **ptlp);
    2315             : int follow_pfn(struct vm_area_struct *vma, unsigned long address,
    2316             :         unsigned long *pfn);
    2317             : int follow_phys(struct vm_area_struct *vma, unsigned long address,
    2318             :                 unsigned int flags, unsigned long *prot, resource_size_t *phys);
    2319             : int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
    2320             :                         void *buf, int len, int write);
    2321             : 
    2322             : extern void truncate_pagecache(struct inode *inode, loff_t new);
    2323             : extern void truncate_setsize(struct inode *inode, loff_t newsize);
    2324             : void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
    2325             : void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
    2326             : int generic_error_remove_page(struct address_space *mapping, struct page *page);
    2327             : 
    2328             : struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
    2329             :                 unsigned long address, struct pt_regs *regs);
    2330             : 
    2331             : #ifdef CONFIG_MMU
    2332             : extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
    2333             :                                   unsigned long address, unsigned int flags,
    2334             :                                   struct pt_regs *regs);
    2335             : extern int fixup_user_fault(struct mm_struct *mm,
    2336             :                             unsigned long address, unsigned int fault_flags,
    2337             :                             bool *unlocked);
    2338             : void unmap_mapping_pages(struct address_space *mapping,
    2339             :                 pgoff_t start, pgoff_t nr, bool even_cows);
    2340             : void unmap_mapping_range(struct address_space *mapping,
    2341             :                 loff_t const holebegin, loff_t const holelen, int even_cows);
    2342             : #else
    2343             : static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
    2344             :                                          unsigned long address, unsigned int flags,
    2345             :                                          struct pt_regs *regs)
    2346             : {
    2347             :         /* should never happen if there's no MMU */
    2348             :         BUG();
    2349             :         return VM_FAULT_SIGBUS;
    2350             : }
    2351             : static inline int fixup_user_fault(struct mm_struct *mm, unsigned long address,
    2352             :                 unsigned int fault_flags, bool *unlocked)
    2353             : {
    2354             :         /* should never happen if there's no MMU */
    2355             :         BUG();
    2356             :         return -EFAULT;
    2357             : }
    2358             : static inline void unmap_mapping_pages(struct address_space *mapping,
    2359             :                 pgoff_t start, pgoff_t nr, bool even_cows) { }
    2360             : static inline void unmap_mapping_range(struct address_space *mapping,
    2361             :                 loff_t const holebegin, loff_t const holelen, int even_cows) { }
    2362             : #endif
    2363             : 
    2364             : static inline void unmap_shared_mapping_range(struct address_space *mapping,
    2365             :                 loff_t const holebegin, loff_t const holelen)
    2366             : {
    2367             :         unmap_mapping_range(mapping, holebegin, holelen, 0);
    2368             : }
    2369             : 
    2370             : static inline struct vm_area_struct *vma_lookup(struct mm_struct *mm,
    2371             :                                                 unsigned long addr);
    2372             : 
    2373             : extern int access_process_vm(struct task_struct *tsk, unsigned long addr,
    2374             :                 void *buf, int len, unsigned int gup_flags);
    2375             : extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
    2376             :                 void *buf, int len, unsigned int gup_flags);
    2377             : extern int __access_remote_vm(struct mm_struct *mm, unsigned long addr,
    2378             :                               void *buf, int len, unsigned int gup_flags);
    2379             : 
    2380             : long get_user_pages_remote(struct mm_struct *mm,
    2381             :                            unsigned long start, unsigned long nr_pages,
    2382             :                            unsigned int gup_flags, struct page **pages,
    2383             :                            int *locked);
    2384             : long pin_user_pages_remote(struct mm_struct *mm,
    2385             :                            unsigned long start, unsigned long nr_pages,
    2386             :                            unsigned int gup_flags, struct page **pages,
    2387             :                            int *locked);
    2388             : 
    2389             : static inline struct page *get_user_page_vma_remote(struct mm_struct *mm,
    2390             :                                                     unsigned long addr,
    2391             :                                                     int gup_flags,
    2392             :                                                     struct vm_area_struct **vmap)
    2393             : {
    2394             :         struct page *page;
    2395             :         struct vm_area_struct *vma;
    2396             :         int got = get_user_pages_remote(mm, addr, 1, gup_flags, &page, NULL);
    2397             : 
    2398             :         if (got < 0)
    2399             :                 return ERR_PTR(got);
    2400             :         if (got == 0)
    2401             :                 return NULL;
    2402             : 
    2403             :         vma = vma_lookup(mm, addr);
    2404             :         if (WARN_ON_ONCE(!vma)) {
    2405             :                 put_page(page);
    2406             :                 return ERR_PTR(-EINVAL);
    2407             :         }
    2408             : 
    2409             :         *vmap = vma;
    2410             :         return page;
    2411             : }
    2412             : 
    2413             : long get_user_pages(unsigned long start, unsigned long nr_pages,
    2414             :                     unsigned int gup_flags, struct page **pages);
    2415             : long pin_user_pages(unsigned long start, unsigned long nr_pages,
    2416             :                     unsigned int gup_flags, struct page **pages);
    2417             : long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
    2418             :                     struct page **pages, unsigned int gup_flags);
    2419             : long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
    2420             :                     struct page **pages, unsigned int gup_flags);
    2421             : 
    2422             : int get_user_pages_fast(unsigned long start, int nr_pages,
    2423             :                         unsigned int gup_flags, struct page **pages);
    2424             : int pin_user_pages_fast(unsigned long start, int nr_pages,
    2425             :                         unsigned int gup_flags, struct page **pages);
    2426             : void folio_add_pin(struct folio *folio);
    2427             : 
    2428             : int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc);
    2429             : int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc,
    2430             :                         struct task_struct *task, bool bypass_rlim);
    2431             : 
    2432             : struct kvec;
    2433             : struct page *get_dump_page(unsigned long addr);
    2434             : 
    2435             : bool folio_mark_dirty(struct folio *folio);
    2436             : bool set_page_dirty(struct page *page);
    2437             : int set_page_dirty_lock(struct page *page);
    2438             : 
    2439             : int get_cmdline(struct task_struct *task, char *buffer, int buflen);
    2440             : 
    2441             : extern unsigned long move_page_tables(struct vm_area_struct *vma,
    2442             :                 unsigned long old_addr, struct vm_area_struct *new_vma,
    2443             :                 unsigned long new_addr, unsigned long len,
    2444             :                 bool need_rmap_locks);
    2445             : 
    2446             : /*
    2447             :  * Flags used by change_protection().  For now we make it a bitmap so
    2448             :  * that we can pass in multiple flags just like parameters.  However
    2449             :  * for now all the callers are only use one of the flags at the same
    2450             :  * time.
    2451             :  */
    2452             : /*
    2453             :  * Whether we should manually check if we can map individual PTEs writable,
    2454             :  * because something (e.g., COW, uffd-wp) blocks that from happening for all
    2455             :  * PTEs automatically in a writable mapping.
    2456             :  */
    2457             : #define  MM_CP_TRY_CHANGE_WRITABLE         (1UL << 0)
    2458             : /* Whether this protection change is for NUMA hints */
    2459             : #define  MM_CP_PROT_NUMA                   (1UL << 1)
    2460             : /* Whether this change is for write protecting */
    2461             : #define  MM_CP_UFFD_WP                     (1UL << 2) /* do wp */
    2462             : #define  MM_CP_UFFD_WP_RESOLVE             (1UL << 3) /* Resolve wp */
    2463             : #define  MM_CP_UFFD_WP_ALL                 (MM_CP_UFFD_WP | \
    2464             :                                             MM_CP_UFFD_WP_RESOLVE)
    2465             : 
    2466             : bool vma_needs_dirty_tracking(struct vm_area_struct *vma);
    2467             : int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot);
    2468             : static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma)
    2469             : {
    2470             :         /*
    2471             :          * We want to check manually if we can change individual PTEs writable
    2472             :          * if we can't do that automatically for all PTEs in a mapping. For
    2473             :          * private mappings, that's always the case when we have write
    2474             :          * permissions as we properly have to handle COW.
    2475             :          */
    2476             :         if (vma->vm_flags & VM_SHARED)
    2477             :                 return vma_wants_writenotify(vma, vma->vm_page_prot);
    2478             :         return !!(vma->vm_flags & VM_WRITE);
    2479             : 
    2480             : }
    2481             : bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr,
    2482             :                              pte_t pte);
    2483             : extern long change_protection(struct mmu_gather *tlb,
    2484             :                               struct vm_area_struct *vma, unsigned long start,
    2485             :                               unsigned long end, unsigned long cp_flags);
    2486             : extern int mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
    2487             :           struct vm_area_struct *vma, struct vm_area_struct **pprev,
    2488             :           unsigned long start, unsigned long end, unsigned long newflags);
    2489             : 
    2490             : /*
    2491             :  * doesn't attempt to fault and will return short.
    2492             :  */
    2493             : int get_user_pages_fast_only(unsigned long start, int nr_pages,
    2494             :                              unsigned int gup_flags, struct page **pages);
    2495             : 
    2496             : static inline bool get_user_page_fast_only(unsigned long addr,
    2497             :                         unsigned int gup_flags, struct page **pagep)
    2498             : {
    2499             :         return get_user_pages_fast_only(addr, 1, gup_flags, pagep) == 1;
    2500             : }
    2501             : /*
    2502             :  * per-process(per-mm_struct) statistics.
    2503             :  */
    2504             : static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
    2505             : {
    2506    15418045 :         return percpu_counter_read_positive(&mm->rss_stat[member]);
    2507             : }
    2508             : 
    2509             : void mm_trace_rss_stat(struct mm_struct *mm, int member);
    2510             : 
    2511    31703536 : static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
    2512             : {
    2513    31703536 :         percpu_counter_add(&mm->rss_stat[member], value);
    2514             : 
    2515    31695850 :         mm_trace_rss_stat(mm, member);
    2516    31700653 : }
    2517             : 
    2518             : static inline void inc_mm_counter(struct mm_struct *mm, int member)
    2519             : {
    2520             :         percpu_counter_inc(&mm->rss_stat[member]);
    2521             : 
    2522             :         mm_trace_rss_stat(mm, member);
    2523             : }
    2524             : 
    2525             : static inline void dec_mm_counter(struct mm_struct *mm, int member)
    2526             : {
    2527             :         percpu_counter_dec(&mm->rss_stat[member]);
    2528             : 
    2529             :         mm_trace_rss_stat(mm, member);
    2530             : }
    2531             : 
    2532             : /* Optimized variant when page is already known not to be PageAnon */
    2533             : static inline int mm_counter_file(struct page *page)
    2534             : {
    2535             :         if (PageSwapBacked(page))
    2536             :                 return MM_SHMEMPAGES;
    2537             :         return MM_FILEPAGES;
    2538             : }
    2539             : 
    2540             : static inline int mm_counter(struct page *page)
    2541             : {
    2542             :         if (PageAnon(page))
    2543             :                 return MM_ANONPAGES;
    2544             :         return mm_counter_file(page);
    2545             : }
    2546             : 
    2547             : static inline unsigned long get_mm_rss(struct mm_struct *mm)
    2548             : {
    2549    15418045 :         return get_mm_counter(mm, MM_FILEPAGES) +
    2550    15418045 :                 get_mm_counter(mm, MM_ANONPAGES) +
    2551             :                 get_mm_counter(mm, MM_SHMEMPAGES);
    2552             : }
    2553             : 
    2554             : static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
    2555             : {
    2556    15418045 :         return max(mm->hiwater_rss, get_mm_rss(mm));
    2557             : }
    2558             : 
    2559             : static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
    2560             : {
    2561             :         return max(mm->hiwater_vm, mm->total_vm);
    2562             : }
    2563             : 
    2564             : static inline void update_hiwater_rss(struct mm_struct *mm)
    2565             : {
    2566             :         unsigned long _rss = get_mm_rss(mm);
    2567             : 
    2568             :         if ((mm)->hiwater_rss < _rss)
    2569             :                 (mm)->hiwater_rss = _rss;
    2570             : }
    2571             : 
    2572             : static inline void update_hiwater_vm(struct mm_struct *mm)
    2573             : {
    2574             :         if (mm->hiwater_vm < mm->total_vm)
    2575             :                 mm->hiwater_vm = mm->total_vm;
    2576             : }
    2577             : 
    2578             : static inline void reset_mm_hiwater_rss(struct mm_struct *mm)
    2579             : {
    2580             :         mm->hiwater_rss = get_mm_rss(mm);
    2581             : }
    2582             : 
    2583    15418045 : static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
    2584             :                                          struct mm_struct *mm)
    2585             : {
    2586    15418045 :         unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
    2587             : 
    2588    15418045 :         if (*maxrss < hiwater_rss)
    2589    15244525 :                 *maxrss = hiwater_rss;
    2590    15418045 : }
    2591             : 
    2592             : #if defined(SPLIT_RSS_COUNTING)
    2593             : void sync_mm_rss(struct mm_struct *mm);
    2594             : #else
    2595             : static inline void sync_mm_rss(struct mm_struct *mm)
    2596             : {
    2597             : }
    2598             : #endif
    2599             : 
    2600             : #ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
    2601             : static inline int pte_special(pte_t pte)
    2602             : {
    2603             :         return 0;
    2604             : }
    2605             : 
    2606             : static inline pte_t pte_mkspecial(pte_t pte)
    2607             : {
    2608             :         return pte;
    2609             : }
    2610             : #endif
    2611             : 
    2612             : #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP
    2613             : static inline int pte_devmap(pte_t pte)
    2614             : {
    2615             :         return 0;
    2616             : }
    2617             : #endif
    2618             : 
    2619             : extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
    2620             :                                spinlock_t **ptl);
    2621             : static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
    2622             :                                     spinlock_t **ptl)
    2623             : {
    2624             :         pte_t *ptep;
    2625             :         __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
    2626             :         return ptep;
    2627             : }
    2628             : 
    2629             : #ifdef __PAGETABLE_P4D_FOLDED
    2630             : static inline int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
    2631             :                                                 unsigned long address)
    2632             : {
    2633             :         return 0;
    2634             : }
    2635             : #else
    2636             : int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
    2637             : #endif
    2638             : 
    2639             : #if defined(__PAGETABLE_PUD_FOLDED) || !defined(CONFIG_MMU)
    2640             : static inline int __pud_alloc(struct mm_struct *mm, p4d_t *p4d,
    2641             :                                                 unsigned long address)
    2642             : {
    2643             :         return 0;
    2644             : }
    2645             : static inline void mm_inc_nr_puds(struct mm_struct *mm) {}
    2646             : static inline void mm_dec_nr_puds(struct mm_struct *mm) {}
    2647             : 
    2648             : #else
    2649             : int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
    2650             : 
    2651             : static inline void mm_inc_nr_puds(struct mm_struct *mm)
    2652             : {
    2653             :         if (mm_pud_folded(mm))
    2654             :                 return;
    2655             :         atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
    2656             : }
    2657             : 
    2658             : static inline void mm_dec_nr_puds(struct mm_struct *mm)
    2659             : {
    2660             :         if (mm_pud_folded(mm))
    2661             :                 return;
    2662             :         atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
    2663             : }
    2664             : #endif
    2665             : 
    2666             : #if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
    2667             : static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
    2668             :                                                 unsigned long address)
    2669             : {
    2670             :         return 0;
    2671             : }
    2672             : 
    2673             : static inline void mm_inc_nr_pmds(struct mm_struct *mm) {}
    2674             : static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
    2675             : 
    2676             : #else
    2677             : int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
    2678             : 
    2679             : static inline void mm_inc_nr_pmds(struct mm_struct *mm)
    2680             : {
    2681             :         if (mm_pmd_folded(mm))
    2682             :                 return;
    2683             :         atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
    2684             : }
    2685             : 
    2686             : static inline void mm_dec_nr_pmds(struct mm_struct *mm)
    2687             : {
    2688             :         if (mm_pmd_folded(mm))
    2689             :                 return;
    2690             :         atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
    2691             : }
    2692             : #endif
    2693             : 
    2694             : #ifdef CONFIG_MMU
    2695             : static inline void mm_pgtables_bytes_init(struct mm_struct *mm)
    2696             : {
    2697             :         atomic_long_set(&mm->pgtables_bytes, 0);
    2698             : }
    2699             : 
    2700             : static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
    2701             : {
    2702             :         return atomic_long_read(&mm->pgtables_bytes);
    2703             : }
    2704             : 
    2705             : static inline void mm_inc_nr_ptes(struct mm_struct *mm)
    2706             : {
    2707             :         atomic_long_add(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
    2708             : }
    2709             : 
    2710             : static inline void mm_dec_nr_ptes(struct mm_struct *mm)
    2711             : {
    2712             :         atomic_long_sub(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
    2713             : }
    2714             : #else
    2715             : 
    2716             : static inline void mm_pgtables_bytes_init(struct mm_struct *mm) {}
    2717             : static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
    2718             : {
    2719             :         return 0;
    2720             : }
    2721             : 
    2722             : static inline void mm_inc_nr_ptes(struct mm_struct *mm) {}
    2723             : static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
    2724             : #endif
    2725             : 
    2726             : int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
    2727             : int __pte_alloc_kernel(pmd_t *pmd);
    2728             : 
    2729             : #if defined(CONFIG_MMU)
    2730             : 
    2731             : static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
    2732             :                 unsigned long address)
    2733             : {
    2734             :         return (unlikely(pgd_none(*pgd)) && __p4d_alloc(mm, pgd, address)) ?
    2735             :                 NULL : p4d_offset(pgd, address);
    2736             : }
    2737             : 
    2738             : static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
    2739             :                 unsigned long address)
    2740             : {
    2741             :         return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
    2742             :                 NULL : pud_offset(p4d, address);
    2743             : }
    2744             : 
    2745             : static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
    2746             : {
    2747             :         return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
    2748             :                 NULL: pmd_offset(pud, address);
    2749             : }
    2750             : #endif /* CONFIG_MMU */
    2751             : 
    2752             : #if USE_SPLIT_PTE_PTLOCKS
    2753             : #if ALLOC_SPLIT_PTLOCKS
    2754             : void __init ptlock_cache_init(void);
    2755             : extern bool ptlock_alloc(struct page *page);
    2756             : extern void ptlock_free(struct page *page);
    2757             : 
    2758             : static inline spinlock_t *ptlock_ptr(struct page *page)
    2759             : {
    2760             :         return page->ptl;
    2761             : }
    2762             : #else /* ALLOC_SPLIT_PTLOCKS */
    2763             : static inline void ptlock_cache_init(void)
    2764             : {
    2765             : }
    2766             : 
    2767             : static inline bool ptlock_alloc(struct page *page)
    2768             : {
    2769             :         return true;
    2770             : }
    2771             : 
    2772             : static inline void ptlock_free(struct page *page)
    2773             : {
    2774             : }
    2775             : 
    2776             : static inline spinlock_t *ptlock_ptr(struct page *page)
    2777             : {
    2778             :         return &page->ptl;
    2779             : }
    2780             : #endif /* ALLOC_SPLIT_PTLOCKS */
    2781             : 
    2782             : static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
    2783             : {
    2784             :         return ptlock_ptr(pmd_page(*pmd));
    2785             : }
    2786             : 
    2787             : static inline bool ptlock_init(struct page *page)
    2788             : {
    2789             :         /*
    2790             :          * prep_new_page() initialize page->private (and therefore page->ptl)
    2791             :          * with 0. Make sure nobody took it in use in between.
    2792             :          *
    2793             :          * It can happen if arch try to use slab for page table allocation:
    2794             :          * slab code uses page->slab_cache, which share storage with page->ptl.
    2795             :          */
    2796             :         VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
    2797             :         if (!ptlock_alloc(page))
    2798             :                 return false;
    2799             :         spin_lock_init(ptlock_ptr(page));
    2800             :         return true;
    2801             : }
    2802             : 
    2803             : #else   /* !USE_SPLIT_PTE_PTLOCKS */
    2804             : /*
    2805             :  * We use mm->page_table_lock to guard all pagetable pages of the mm.
    2806             :  */
    2807             : static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
    2808             : {
    2809             :         return &mm->page_table_lock;
    2810             : }
    2811             : static inline void ptlock_cache_init(void) {}
    2812             : static inline bool ptlock_init(struct page *page) { return true; }
    2813             : static inline void ptlock_free(struct page *page) {}
    2814             : #endif /* USE_SPLIT_PTE_PTLOCKS */
    2815             : 
    2816             : static inline bool pgtable_pte_page_ctor(struct page *page)
    2817             : {
    2818             :         if (!ptlock_init(page))
    2819             :                 return false;
    2820             :         __SetPageTable(page);
    2821             :         inc_lruvec_page_state(page, NR_PAGETABLE);
    2822             :         return true;
    2823             : }
    2824             : 
    2825             : static inline void pgtable_pte_page_dtor(struct page *page)
    2826             : {
    2827             :         ptlock_free(page);
    2828             :         __ClearPageTable(page);
    2829             :         dec_lruvec_page_state(page, NR_PAGETABLE);
    2830             : }
    2831             : 
    2832             : pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp);
    2833             : static inline pte_t *pte_offset_map(pmd_t *pmd, unsigned long addr)
    2834             : {
    2835             :         return __pte_offset_map(pmd, addr, NULL);
    2836             : }
    2837             : 
    2838             : pte_t *__pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd,
    2839             :                         unsigned long addr, spinlock_t **ptlp);
    2840             : static inline pte_t *pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd,
    2841             :                         unsigned long addr, spinlock_t **ptlp)
    2842             : {
    2843           0 :         pte_t *pte;
    2844             : 
    2845           0 :         __cond_lock(*ptlp, pte = __pte_offset_map_lock(mm, pmd, addr, ptlp));
    2846           0 :         return pte;
    2847             : }
    2848             : 
    2849             : pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
    2850             :                         unsigned long addr, spinlock_t **ptlp);
    2851             : 
    2852             : #define pte_unmap_unlock(pte, ptl)      do {            \
    2853             :         spin_unlock(ptl);                               \
    2854             :         pte_unmap(pte);                                 \
    2855             : } while (0)
    2856             : 
    2857             : #define pte_alloc(mm, pmd) (unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, pmd))
    2858             : 
    2859             : #define pte_alloc_map(mm, pmd, address)                 \
    2860             :         (pte_alloc(mm, pmd) ? NULL : pte_offset_map(pmd, address))
    2861             : 
    2862             : #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
    2863             :         (pte_alloc(mm, pmd) ?                   \
    2864             :                  NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
    2865             : 
    2866             : #define pte_alloc_kernel(pmd, address)                  \
    2867             :         ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd))? \
    2868             :                 NULL: pte_offset_kernel(pmd, address))
    2869             : 
    2870             : #if USE_SPLIT_PMD_PTLOCKS
    2871             : 
    2872             : static inline struct page *pmd_pgtable_page(pmd_t *pmd)
    2873             : {
    2874             :         unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
    2875             :         return virt_to_page((void *)((unsigned long) pmd & mask));
    2876             : }
    2877             : 
    2878             : static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
    2879             : {
    2880             :         return ptlock_ptr(pmd_pgtable_page(pmd));
    2881             : }
    2882             : 
    2883             : static inline bool pmd_ptlock_init(struct page *page)
    2884             : {
    2885             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    2886             :         page->pmd_huge_pte = NULL;
    2887             : #endif
    2888             :         return ptlock_init(page);
    2889             : }
    2890             : 
    2891             : static inline void pmd_ptlock_free(struct page *page)
    2892             : {
    2893             : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    2894             :         VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
    2895             : #endif
    2896             :         ptlock_free(page);
    2897             : }
    2898             : 
    2899             : #define pmd_huge_pte(mm, pmd) (pmd_pgtable_page(pmd)->pmd_huge_pte)
    2900             : 
    2901             : #else
    2902             : 
    2903             : static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
    2904             : {
    2905             :         return &mm->page_table_lock;
    2906             : }
    2907             : 
    2908             : static inline bool pmd_ptlock_init(struct page *page) { return true; }
    2909             : static inline void pmd_ptlock_free(struct page *page) {}
    2910             : 
    2911             : #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
    2912             : 
    2913             : #endif
    2914             : 
    2915             : static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
    2916             : {
    2917             :         spinlock_t *ptl = pmd_lockptr(mm, pmd);
    2918             :         spin_lock(ptl);
    2919             :         return ptl;
    2920             : }
    2921             : 
    2922             : static inline bool pgtable_pmd_page_ctor(struct page *page)
    2923             : {
    2924             :         if (!pmd_ptlock_init(page))
    2925             :                 return false;
    2926             :         __SetPageTable(page);
    2927             :         inc_lruvec_page_state(page, NR_PAGETABLE);
    2928             :         return true;
    2929             : }
    2930             : 
    2931             : static inline void pgtable_pmd_page_dtor(struct page *page)
    2932             : {
    2933             :         pmd_ptlock_free(page);
    2934             :         __ClearPageTable(page);
    2935             :         dec_lruvec_page_state(page, NR_PAGETABLE);
    2936             : }
    2937             : 
    2938             : /*
    2939             :  * No scalability reason to split PUD locks yet, but follow the same pattern
    2940             :  * as the PMD locks to make it easier if we decide to.  The VM should not be
    2941             :  * considered ready to switch to split PUD locks yet; there may be places
    2942             :  * which need to be converted from page_table_lock.
    2943             :  */
    2944             : static inline spinlock_t *pud_lockptr(struct mm_struct *mm, pud_t *pud)
    2945             : {
    2946             :         return &mm->page_table_lock;
    2947             : }
    2948             : 
    2949             : static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
    2950             : {
    2951             :         spinlock_t *ptl = pud_lockptr(mm, pud);
    2952             : 
    2953             :         spin_lock(ptl);
    2954             :         return ptl;
    2955             : }
    2956             : 
    2957             : extern void __init pagecache_init(void);
    2958             : extern void free_initmem(void);
    2959             : 
    2960             : /*
    2961             :  * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
    2962             :  * into the buddy system. The freed pages will be poisoned with pattern
    2963             :  * "poison" if it's within range [0, UCHAR_MAX].
    2964             :  * Return pages freed into the buddy system.
    2965             :  */
    2966             : extern unsigned long free_reserved_area(void *start, void *end,
    2967             :                                         int poison, const char *s);
    2968             : 
    2969             : extern void adjust_managed_page_count(struct page *page, long count);
    2970             : 
    2971             : extern void reserve_bootmem_region(phys_addr_t start,
    2972             :                                    phys_addr_t end, int nid);
    2973             : 
    2974             : /* Free the reserved page into the buddy system, so it gets managed. */
    2975             : static inline void free_reserved_page(struct page *page)
    2976             : {
    2977             :         ClearPageReserved(page);
    2978             :         init_page_count(page);
    2979             :         __free_page(page);
    2980             :         adjust_managed_page_count(page, 1);
    2981             : }
    2982             : #define free_highmem_page(page) free_reserved_page(page)
    2983             : 
    2984             : static inline void mark_page_reserved(struct page *page)
    2985             : {
    2986             :         SetPageReserved(page);
    2987             :         adjust_managed_page_count(page, -1);
    2988             : }
    2989             : 
    2990             : /*
    2991             :  * Default method to free all the __init memory into the buddy system.
    2992             :  * The freed pages will be poisoned with pattern "poison" if it's within
    2993             :  * range [0, UCHAR_MAX].
    2994             :  * Return pages freed into the buddy system.
    2995             :  */
    2996             : static inline unsigned long free_initmem_default(int poison)
    2997             : {
    2998             :         extern char __init_begin[], __init_end[];
    2999             : 
    3000             :         return free_reserved_area(&__init_begin, &__init_end,
    3001             :                                   poison, "unused kernel image (initmem)");
    3002             : }
    3003             : 
    3004             : static inline unsigned long get_num_physpages(void)
    3005             : {
    3006             :         int nid;
    3007             :         unsigned long phys_pages = 0;
    3008             : 
    3009             :         for_each_online_node(nid)
    3010             :                 phys_pages += node_present_pages(nid);
    3011             : 
    3012             :         return phys_pages;
    3013             : }
    3014             : 
    3015             : /*
    3016             :  * Using memblock node mappings, an architecture may initialise its
    3017             :  * zones, allocate the backing mem_map and account for memory holes in an
    3018             :  * architecture independent manner.
    3019             :  *
    3020             :  * An architecture is expected to register range of page frames backed by
    3021             :  * physical memory with memblock_add[_node]() before calling
    3022             :  * free_area_init() passing in the PFN each zone ends at. At a basic
    3023             :  * usage, an architecture is expected to do something like
    3024             :  *
    3025             :  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
    3026             :  *                                                       max_highmem_pfn};
    3027             :  * for_each_valid_physical_page_range()
    3028             :  *      memblock_add_node(base, size, nid, MEMBLOCK_NONE)
    3029             :  * free_area_init(max_zone_pfns);
    3030             :  */
    3031             : void free_area_init(unsigned long *max_zone_pfn);
    3032             : unsigned long node_map_pfn_alignment(void);
    3033             : unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
    3034             :                                                 unsigned long end_pfn);
    3035             : extern unsigned long absent_pages_in_range(unsigned long start_pfn,
    3036             :                                                 unsigned long end_pfn);
    3037             : extern void get_pfn_range_for_nid(unsigned int nid,
    3038             :                         unsigned long *start_pfn, unsigned long *end_pfn);
    3039             : 
    3040             : #ifndef CONFIG_NUMA
    3041             : static inline int early_pfn_to_nid(unsigned long pfn)
    3042             : {
    3043             :         return 0;
    3044             : }
    3045             : #else
    3046             : /* please see mm/page_alloc.c */
    3047             : extern int __meminit early_pfn_to_nid(unsigned long pfn);
    3048             : #endif
    3049             : 
    3050             : extern void set_dma_reserve(unsigned long new_dma_reserve);
    3051             : extern void mem_init(void);
    3052             : extern void __init mmap_init(void);
    3053             : 
    3054             : extern void __show_mem(unsigned int flags, nodemask_t *nodemask, int max_zone_idx);
    3055             : static inline void show_mem(unsigned int flags, nodemask_t *nodemask)
    3056             : {
    3057             :         __show_mem(flags, nodemask, MAX_NR_ZONES - 1);
    3058             : }
    3059             : extern long si_mem_available(void);
    3060             : extern void si_meminfo(struct sysinfo * val);
    3061             : extern void si_meminfo_node(struct sysinfo *val, int nid);
    3062             : #ifdef __HAVE_ARCH_RESERVED_KERNEL_PAGES
    3063             : extern unsigned long arch_reserved_kernel_pages(void);
    3064             : #endif
    3065             : 
    3066             : extern __printf(3, 4)
    3067             : void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...);
    3068             : 
    3069             : extern void setup_per_cpu_pageset(void);
    3070             : 
    3071             : /* nommu.c */
    3072             : extern atomic_long_t mmap_pages_allocated;
    3073             : extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
    3074             : 
    3075             : /* interval_tree.c */
    3076             : void vma_interval_tree_insert(struct vm_area_struct *node,
    3077             :                               struct rb_root_cached *root);
    3078             : void vma_interval_tree_insert_after(struct vm_area_struct *node,
    3079             :                                     struct vm_area_struct *prev,
    3080             :                                     struct rb_root_cached *root);
    3081             : void vma_interval_tree_remove(struct vm_area_struct *node,
    3082             :                               struct rb_root_cached *root);
    3083             : struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root_cached *root,
    3084             :                                 unsigned long start, unsigned long last);
    3085             : struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
    3086             :                                 unsigned long start, unsigned long last);
    3087             : 
    3088             : #define vma_interval_tree_foreach(vma, root, start, last)               \
    3089             :         for (vma = vma_interval_tree_iter_first(root, start, last);     \
    3090             :              vma; vma = vma_interval_tree_iter_next(vma, start, last))
    3091             : 
    3092             : void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
    3093             :                                    struct rb_root_cached *root);
    3094             : void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
    3095             :                                    struct rb_root_cached *root);
    3096             : struct anon_vma_chain *
    3097             : anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
    3098             :                                   unsigned long start, unsigned long last);
    3099             : struct anon_vma_chain *anon_vma_interval_tree_iter_next(
    3100             :         struct anon_vma_chain *node, unsigned long start, unsigned long last);
    3101             : #ifdef CONFIG_DEBUG_VM_RB
    3102             : void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
    3103             : #endif
    3104             : 
    3105             : #define anon_vma_interval_tree_foreach(avc, root, start, last)           \
    3106             :         for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
    3107             :              avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
    3108             : 
    3109             : /* mmap.c */
    3110             : extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
    3111             : extern int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
    3112             :                       unsigned long start, unsigned long end, pgoff_t pgoff,
    3113             :                       struct vm_area_struct *next);
    3114             : extern int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
    3115             :                        unsigned long start, unsigned long end, pgoff_t pgoff);
    3116             : extern struct vm_area_struct *vma_merge(struct vma_iterator *vmi,
    3117             :         struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,
    3118             :         unsigned long end, unsigned long vm_flags, struct anon_vma *,
    3119             :         struct file *, pgoff_t, struct mempolicy *, struct vm_userfaultfd_ctx,
    3120             :         struct anon_vma_name *);
    3121             : extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
    3122             : extern int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
    3123             :                        unsigned long addr, int new_below);
    3124             : extern int split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
    3125             :                          unsigned long addr, int new_below);
    3126             : extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
    3127             : extern void unlink_file_vma(struct vm_area_struct *);
    3128             : extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
    3129             :         unsigned long addr, unsigned long len, pgoff_t pgoff,
    3130             :         bool *need_rmap_locks);
    3131             : extern void exit_mmap(struct mm_struct *);
    3132             : 
    3133             : static inline int check_data_rlimit(unsigned long rlim,
    3134             :                                     unsigned long new,
    3135             :                                     unsigned long start,
    3136             :                                     unsigned long end_data,
    3137             :                                     unsigned long start_data)
    3138             : {
    3139             :         if (rlim < RLIM_INFINITY) {
    3140             :                 if (((new - start) + (end_data - start_data)) > rlim)
    3141             :                         return -ENOSPC;
    3142             :         }
    3143             : 
    3144             :         return 0;
    3145             : }
    3146             : 
    3147             : extern int mm_take_all_locks(struct mm_struct *mm);
    3148             : extern void mm_drop_all_locks(struct mm_struct *mm);
    3149             : 
    3150             : extern int set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
    3151             : extern int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
    3152             : extern struct file *get_mm_exe_file(struct mm_struct *mm);
    3153             : extern struct file *get_task_exe_file(struct task_struct *task);
    3154             : 
    3155             : extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);
    3156             : extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);
    3157             : 
    3158             : extern bool vma_is_special_mapping(const struct vm_area_struct *vma,
    3159             :                                    const struct vm_special_mapping *sm);
    3160             : extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
    3161             :                                    unsigned long addr, unsigned long len,
    3162             :                                    unsigned long flags,
    3163             :                                    const struct vm_special_mapping *spec);
    3164             : /* This is an obsolete alternative to _install_special_mapping. */
    3165             : extern int install_special_mapping(struct mm_struct *mm,
    3166             :                                    unsigned long addr, unsigned long len,
    3167             :                                    unsigned long flags, struct page **pages);
    3168             : 
    3169             : unsigned long randomize_stack_top(unsigned long stack_top);
    3170             : unsigned long randomize_page(unsigned long start, unsigned long range);
    3171             : 
    3172             : extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
    3173             : 
    3174             : extern unsigned long mmap_region(struct file *file, unsigned long addr,
    3175             :         unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
    3176             :         struct list_head *uf);
    3177             : extern unsigned long do_mmap(struct file *file, unsigned long addr,
    3178             :         unsigned long len, unsigned long prot, unsigned long flags,
    3179             :         unsigned long pgoff, unsigned long *populate, struct list_head *uf);
    3180             : extern int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
    3181             :                          unsigned long start, size_t len, struct list_head *uf,
    3182             :                          bool unlock);
    3183             : extern int do_munmap(struct mm_struct *, unsigned long, size_t,
    3184             :                      struct list_head *uf);
    3185             : extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior);
    3186             : 
    3187             : #ifdef CONFIG_MMU
    3188             : extern int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
    3189             :                          unsigned long start, unsigned long end,
    3190             :                          struct list_head *uf, bool unlock);
    3191             : extern int __mm_populate(unsigned long addr, unsigned long len,
    3192             :                          int ignore_errors);
    3193             : static inline void mm_populate(unsigned long addr, unsigned long len)
    3194             : {
    3195             :         /* Ignore errors */
    3196             :         (void) __mm_populate(addr, len, 1);
    3197             : }
    3198             : #else
    3199             : static inline void mm_populate(unsigned long addr, unsigned long len) {}
    3200             : #endif
    3201             : 
    3202             : /* These take the mm semaphore themselves */
    3203             : extern int __must_check vm_brk(unsigned long, unsigned long);
    3204             : extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
    3205             : extern int vm_munmap(unsigned long, size_t);
    3206             : extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
    3207             :         unsigned long, unsigned long,
    3208             :         unsigned long, unsigned long);
    3209             : 
    3210             : struct vm_unmapped_area_info {
    3211             : #define VM_UNMAPPED_AREA_TOPDOWN 1
    3212             :         unsigned long flags;
    3213             :         unsigned long length;
    3214             :         unsigned long low_limit;
    3215             :         unsigned long high_limit;
    3216             :         unsigned long align_mask;
    3217             :         unsigned long align_offset;
    3218             : };
    3219             : 
    3220             : extern unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info);
    3221             : 
    3222             : /* truncate.c */
    3223             : extern void truncate_inode_pages(struct address_space *, loff_t);
    3224             : extern void truncate_inode_pages_range(struct address_space *,
    3225             :                                        loff_t lstart, loff_t lend);
    3226             : extern void truncate_inode_pages_final(struct address_space *);
    3227             : 
    3228             : /* generic vm_area_ops exported for stackable file systems */
    3229             : extern vm_fault_t filemap_fault(struct vm_fault *vmf);
    3230             : extern vm_fault_t filemap_map_pages(struct vm_fault *vmf,
    3231             :                 pgoff_t start_pgoff, pgoff_t end_pgoff);
    3232             : extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf);
    3233             : 
    3234             : extern unsigned long stack_guard_gap;
    3235             : /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
    3236             : int expand_stack_locked(struct vm_area_struct *vma, unsigned long address);
    3237             : struct vm_area_struct *expand_stack(struct mm_struct * mm, unsigned long addr);
    3238             : 
    3239             : /* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */
    3240             : int expand_downwards(struct vm_area_struct *vma, unsigned long address);
    3241             : 
    3242             : /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
    3243             : extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
    3244             : extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
    3245             :                                              struct vm_area_struct **pprev);
    3246             : 
    3247             : /*
    3248             :  * Look up the first VMA which intersects the interval [start_addr, end_addr)
    3249             :  * NULL if none.  Assume start_addr < end_addr.
    3250             :  */
    3251             : struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
    3252             :                         unsigned long start_addr, unsigned long end_addr);
    3253             : 
    3254             : /**
    3255             :  * vma_lookup() - Find a VMA at a specific address
    3256             :  * @mm: The process address space.
    3257             :  * @addr: The user address.
    3258             :  *
    3259             :  * Return: The vm_area_struct at the given address, %NULL otherwise.
    3260             :  */
    3261             : static inline
    3262             : struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr)
    3263             : {
    3264             :         return mtree_load(&mm->mm_mt, addr);
    3265             : }
    3266             : 
    3267             : static inline unsigned long vm_start_gap(struct vm_area_struct *vma)
    3268             : {
    3269             :         unsigned long vm_start = vma->vm_start;
    3270             : 
    3271             :         if (vma->vm_flags & VM_GROWSDOWN) {
    3272             :                 vm_start -= stack_guard_gap;
    3273             :                 if (vm_start > vma->vm_start)
    3274             :                         vm_start = 0;
    3275             :         }
    3276             :         return vm_start;
    3277             : }
    3278             : 
    3279             : static inline unsigned long vm_end_gap(struct vm_area_struct *vma)
    3280             : {
    3281             :         unsigned long vm_end = vma->vm_end;
    3282             : 
    3283             :         if (vma->vm_flags & VM_GROWSUP) {
    3284             :                 vm_end += stack_guard_gap;
    3285             :                 if (vm_end < vma->vm_end)
    3286             :                         vm_end = -PAGE_SIZE;
    3287             :         }
    3288             :         return vm_end;
    3289             : }
    3290             : 
    3291             : static inline unsigned long vma_pages(struct vm_area_struct *vma)
    3292             : {
    3293    47957104 :         return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
    3294             : }
    3295             : 
    3296             : /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
    3297             : static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
    3298             :                                 unsigned long vm_start, unsigned long vm_end)
    3299             : {
    3300             :         struct vm_area_struct *vma = vma_lookup(mm, vm_start);
    3301             : 
    3302             :         if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
    3303             :                 vma = NULL;
    3304             : 
    3305             :         return vma;
    3306             : }
    3307             : 
    3308             : static inline bool range_in_vma(struct vm_area_struct *vma,
    3309             :                                 unsigned long start, unsigned long end)
    3310             : {
    3311             :         return (vma && vma->vm_start <= start && end <= vma->vm_end);
    3312             : }
    3313             : 
    3314             : #ifdef CONFIG_MMU
    3315             : pgprot_t vm_get_page_prot(unsigned long vm_flags);
    3316             : void vma_set_page_prot(struct vm_area_struct *vma);
    3317             : #else
    3318             : static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
    3319             : {
    3320             :         return __pgprot(0);
    3321             : }
    3322             : static inline void vma_set_page_prot(struct vm_area_struct *vma)
    3323             : {
    3324             :         vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
    3325             : }
    3326             : #endif
    3327             : 
    3328             : void vma_set_file(struct vm_area_struct *vma, struct file *file);
    3329             : 
    3330             : #ifdef CONFIG_NUMA_BALANCING
    3331             : unsigned long change_prot_numa(struct vm_area_struct *vma,
    3332             :                         unsigned long start, unsigned long end);
    3333             : #endif
    3334             : 
    3335             : struct vm_area_struct *find_extend_vma_locked(struct mm_struct *,
    3336             :                 unsigned long addr);
    3337             : int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
    3338             :                         unsigned long pfn, unsigned long size, pgprot_t);
    3339             : int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr,
    3340             :                 unsigned long pfn, unsigned long size, pgprot_t prot);
    3341             : int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
    3342             : int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
    3343             :                         struct page **pages, unsigned long *num);
    3344             : int vm_map_pages(struct vm_area_struct *vma, struct page **pages,
    3345             :                                 unsigned long num);
    3346             : int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
    3347             :                                 unsigned long num);
    3348             : vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
    3349             :                         unsigned long pfn);
    3350             : vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
    3351             :                         unsigned long pfn, pgprot_t pgprot);
    3352             : vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
    3353             :                         pfn_t pfn);
    3354             : vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
    3355             :                 unsigned long addr, pfn_t pfn);
    3356             : int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
    3357             : 
    3358             : static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
    3359             :                                 unsigned long addr, struct page *page)
    3360             : {
    3361             :         int err = vm_insert_page(vma, addr, page);
    3362             : 
    3363             :         if (err == -ENOMEM)
    3364             :                 return VM_FAULT_OOM;
    3365             :         if (err < 0 && err != -EBUSY)
    3366             :                 return VM_FAULT_SIGBUS;
    3367             : 
    3368             :         return VM_FAULT_NOPAGE;
    3369             : }
    3370             : 
    3371             : #ifndef io_remap_pfn_range
    3372             : static inline int io_remap_pfn_range(struct vm_area_struct *vma,
    3373             :                                      unsigned long addr, unsigned long pfn,
    3374             :                                      unsigned long size, pgprot_t prot)
    3375             : {
    3376             :         return remap_pfn_range(vma, addr, pfn, size, pgprot_decrypted(prot));
    3377             : }
    3378             : #endif
    3379             : 
    3380             : static inline vm_fault_t vmf_error(int err)
    3381             : {
    3382           0 :         if (err == -ENOMEM)
    3383             :                 return VM_FAULT_OOM;
    3384           0 :         else if (err == -EHWPOISON)
    3385           0 :                 return VM_FAULT_HWPOISON;
    3386             :         return VM_FAULT_SIGBUS;
    3387             : }
    3388             : 
    3389             : struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
    3390             :                          unsigned int foll_flags);
    3391             : 
    3392             : static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
    3393             : {
    3394             :         if (vm_fault & VM_FAULT_OOM)
    3395             :                 return -ENOMEM;
    3396             :         if (vm_fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE))
    3397             :                 return (foll_flags & FOLL_HWPOISON) ? -EHWPOISON : -EFAULT;
    3398             :         if (vm_fault & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
    3399             :                 return -EFAULT;
    3400             :         return 0;
    3401             : }
    3402             : 
    3403             : /*
    3404             :  * Indicates whether GUP can follow a PROT_NONE mapped page, or whether
    3405             :  * a (NUMA hinting) fault is required.
    3406             :  */
    3407             : static inline bool gup_can_follow_protnone(unsigned int flags)
    3408             : {
    3409             :         /*
    3410             :          * FOLL_FORCE has to be able to make progress even if the VMA is
    3411             :          * inaccessible. Further, FOLL_FORCE access usually does not represent
    3412             :          * application behaviour and we should avoid triggering NUMA hinting
    3413             :          * faults.
    3414             :          */
    3415             :         return flags & FOLL_FORCE;
    3416             : }
    3417             : 
    3418             : typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
    3419             : extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
    3420             :                                unsigned long size, pte_fn_t fn, void *data);
    3421             : extern int apply_to_existing_page_range(struct mm_struct *mm,
    3422             :                                    unsigned long address, unsigned long size,
    3423             :                                    pte_fn_t fn, void *data);
    3424             : 
    3425             : #ifdef CONFIG_PAGE_POISONING
    3426             : extern void __kernel_poison_pages(struct page *page, int numpages);
    3427             : extern void __kernel_unpoison_pages(struct page *page, int numpages);
    3428             : extern bool _page_poisoning_enabled_early;
    3429             : DECLARE_STATIC_KEY_FALSE(_page_poisoning_enabled);
    3430             : static inline bool page_poisoning_enabled(void)
    3431             : {
    3432             :         return _page_poisoning_enabled_early;
    3433             : }
    3434             : /*
    3435             :  * For use in fast paths after init_mem_debugging() has run, or when a
    3436             :  * false negative result is not harmful when called too early.
    3437             :  */
    3438             : static inline bool page_poisoning_enabled_static(void)
    3439             : {
    3440             :         return static_branch_unlikely(&_page_poisoning_enabled);
    3441             : }
    3442             : static inline void kernel_poison_pages(struct page *page, int numpages)
    3443             : {
    3444             :         if (page_poisoning_enabled_static())
    3445             :                 __kernel_poison_pages(page, numpages);
    3446             : }
    3447             : static inline void kernel_unpoison_pages(struct page *page, int numpages)
    3448             : {
    3449             :         if (page_poisoning_enabled_static())
    3450             :                 __kernel_unpoison_pages(page, numpages);
    3451             : }
    3452             : #else
    3453             : static inline bool page_poisoning_enabled(void) { return false; }
    3454             : static inline bool page_poisoning_enabled_static(void) { return false; }
    3455             : static inline void __kernel_poison_pages(struct page *page, int nunmpages) { }
    3456             : static inline void kernel_poison_pages(struct page *page, int numpages) { }
    3457             : static inline void kernel_unpoison_pages(struct page *page, int numpages) { }
    3458             : #endif
    3459             : 
    3460             : DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc);
    3461             : static inline bool want_init_on_alloc(gfp_t flags)
    3462             : {
    3463             :         if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
    3464             :                                 &init_on_alloc))
    3465             :                 return true;
    3466             :         return flags & __GFP_ZERO;
    3467             : }
    3468             : 
    3469             : DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
    3470             : static inline bool want_init_on_free(void)
    3471             : {
    3472             :         return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
    3473             :                                    &init_on_free);
    3474             : }
    3475             : 
    3476             : extern bool _debug_pagealloc_enabled_early;
    3477             : DECLARE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
    3478             : 
    3479             : static inline bool debug_pagealloc_enabled(void)
    3480             : {
    3481             :         return IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
    3482             :                 _debug_pagealloc_enabled_early;
    3483             : }
    3484             : 
    3485             : /*
    3486             :  * For use in fast paths after init_debug_pagealloc() has run, or when a
    3487             :  * false negative result is not harmful when called too early.
    3488             :  */
    3489             : static inline bool debug_pagealloc_enabled_static(void)
    3490             : {
    3491             :         if (!IS_ENABLED(CONFIG_DEBUG_PAGEALLOC))
    3492             :                 return false;
    3493             : 
    3494             :         return static_branch_unlikely(&_debug_pagealloc_enabled);
    3495             : }
    3496             : 
    3497             : /*
    3498             :  * To support DEBUG_PAGEALLOC architecture must ensure that
    3499             :  * __kernel_map_pages() never fails
    3500             :  */
    3501             : extern void __kernel_map_pages(struct page *page, int numpages, int enable);
    3502             : #ifdef CONFIG_DEBUG_PAGEALLOC
    3503             : static inline void debug_pagealloc_map_pages(struct page *page, int numpages)
    3504             : {
    3505             :         if (debug_pagealloc_enabled_static())
    3506             :                 __kernel_map_pages(page, numpages, 1);
    3507             : }
    3508             : 
    3509             : static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages)
    3510             : {
    3511             :         if (debug_pagealloc_enabled_static())
    3512             :                 __kernel_map_pages(page, numpages, 0);
    3513             : }
    3514             : 
    3515             : extern unsigned int _debug_guardpage_minorder;
    3516             : DECLARE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
    3517             : 
    3518             : static inline unsigned int debug_guardpage_minorder(void)
    3519             : {
    3520             :         return _debug_guardpage_minorder;
    3521             : }
    3522             : 
    3523             : static inline bool debug_guardpage_enabled(void)
    3524             : {
    3525             :         return static_branch_unlikely(&_debug_guardpage_enabled);
    3526             : }
    3527             : 
    3528             : static inline bool page_is_guard(struct page *page)
    3529             : {
    3530             :         if (!debug_guardpage_enabled())
    3531             :                 return false;
    3532             : 
    3533             :         return PageGuard(page);
    3534             : }
    3535             : 
    3536             : bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
    3537             :                       int migratetype);
    3538             : static inline bool set_page_guard(struct zone *zone, struct page *page,
    3539             :                                   unsigned int order, int migratetype)
    3540             : {
    3541             :         if (!debug_guardpage_enabled())
    3542             :                 return false;
    3543             :         return __set_page_guard(zone, page, order, migratetype);
    3544             : }
    3545             : 
    3546             : void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
    3547             :                         int migratetype);
    3548             : static inline void clear_page_guard(struct zone *zone, struct page *page,
    3549             :                                     unsigned int order, int migratetype)
    3550             : {
    3551             :         if (!debug_guardpage_enabled())
    3552             :                 return;
    3553             :         __clear_page_guard(zone, page, order, migratetype);
    3554             : }
    3555             : 
    3556             : #else   /* CONFIG_DEBUG_PAGEALLOC */
    3557             : static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {}
    3558             : static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {}
    3559             : static inline unsigned int debug_guardpage_minorder(void) { return 0; }
    3560             : static inline bool debug_guardpage_enabled(void) { return false; }
    3561             : static inline bool page_is_guard(struct page *page) { return false; }
    3562             : static inline bool set_page_guard(struct zone *zone, struct page *page,
    3563             :                         unsigned int order, int migratetype) { return false; }
    3564             : static inline void clear_page_guard(struct zone *zone, struct page *page,
    3565             :                                 unsigned int order, int migratetype) {}
    3566             : #endif  /* CONFIG_DEBUG_PAGEALLOC */
    3567             : 
    3568             : #ifdef __HAVE_ARCH_GATE_AREA
    3569             : extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
    3570             : extern int in_gate_area_no_mm(unsigned long addr);
    3571             : extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
    3572             : #else
    3573             : static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
    3574             : {
    3575             :         return NULL;
    3576             : }
    3577             : static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
    3578             : static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
    3579             : {
    3580             :         return 0;
    3581             : }
    3582             : #endif  /* __HAVE_ARCH_GATE_AREA */
    3583             : 
    3584             : extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
    3585             : 
    3586             : #ifdef CONFIG_SYSCTL
    3587             : extern int sysctl_drop_caches;
    3588             : int drop_caches_sysctl_handler(struct ctl_table *, int, void *, size_t *,
    3589             :                 loff_t *);
    3590             : #endif
    3591             : 
    3592             : void drop_slab(void);
    3593             : 
    3594             : #ifndef CONFIG_MMU
    3595             : #define randomize_va_space 0
    3596             : #else
    3597             : extern int randomize_va_space;
    3598             : #endif
    3599             : 
    3600             : const char * arch_vma_name(struct vm_area_struct *vma);
    3601             : #ifdef CONFIG_MMU
    3602             : void print_vma_addr(char *prefix, unsigned long rip);
    3603             : #else
    3604             : static inline void print_vma_addr(char *prefix, unsigned long rip)
    3605             : {
    3606             : }
    3607             : #endif
    3608             : 
    3609             : void *sparse_buffer_alloc(unsigned long size);
    3610             : struct page * __populate_section_memmap(unsigned long pfn,
    3611             :                 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
    3612             :                 struct dev_pagemap *pgmap);
    3613             : void pmd_init(void *addr);
    3614             : void pud_init(void *addr);
    3615             : pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
    3616             : p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
    3617             : pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);
    3618             : pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
    3619             : pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
    3620             :                             struct vmem_altmap *altmap, struct page *reuse);
    3621             : void *vmemmap_alloc_block(unsigned long size, int node);
    3622             : struct vmem_altmap;
    3623             : void *vmemmap_alloc_block_buf(unsigned long size, int node,
    3624             :                               struct vmem_altmap *altmap);
    3625             : void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
    3626             : void vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
    3627             :                      unsigned long addr, unsigned long next);
    3628             : int vmemmap_check_pmd(pmd_t *pmd, int node,
    3629             :                       unsigned long addr, unsigned long next);
    3630             : int vmemmap_populate_basepages(unsigned long start, unsigned long end,
    3631             :                                int node, struct vmem_altmap *altmap);
    3632             : int vmemmap_populate_hugepages(unsigned long start, unsigned long end,
    3633             :                                int node, struct vmem_altmap *altmap);
    3634             : int vmemmap_populate(unsigned long start, unsigned long end, int node,
    3635             :                 struct vmem_altmap *altmap);
    3636             : void vmemmap_populate_print_last(void);
    3637             : #ifdef CONFIG_MEMORY_HOTPLUG
    3638             : void vmemmap_free(unsigned long start, unsigned long end,
    3639             :                 struct vmem_altmap *altmap);
    3640             : #endif
    3641             : 
    3642             : #ifdef CONFIG_ARCH_WANT_OPTIMIZE_VMEMMAP
    3643             : static inline bool vmemmap_can_optimize(struct vmem_altmap *altmap,
    3644             :                                            struct dev_pagemap *pgmap)
    3645             : {
    3646             :         return is_power_of_2(sizeof(struct page)) &&
    3647             :                 pgmap && (pgmap_vmemmap_nr(pgmap) > 1) && !altmap;
    3648             : }
    3649             : #else
    3650             : static inline bool vmemmap_can_optimize(struct vmem_altmap *altmap,
    3651             :                                            struct dev_pagemap *pgmap)
    3652             : {
    3653             :         return false;
    3654             : }
    3655             : #endif
    3656             : 
    3657             : void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
    3658             :                                   unsigned long nr_pages);
    3659             : 
    3660             : enum mf_flags {
    3661             :         MF_COUNT_INCREASED = 1 << 0,
    3662             :         MF_ACTION_REQUIRED = 1 << 1,
    3663             :         MF_MUST_KILL = 1 << 2,
    3664             :         MF_SOFT_OFFLINE = 1 << 3,
    3665             :         MF_UNPOISON = 1 << 4,
    3666             :         MF_SW_SIMULATED = 1 << 5,
    3667             :         MF_NO_RETRY = 1 << 6,
    3668             : };
    3669             : int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
    3670             :                       unsigned long count, int mf_flags);
    3671             : extern int memory_failure(unsigned long pfn, int flags);
    3672             : extern void memory_failure_queue_kick(int cpu);
    3673             : extern int unpoison_memory(unsigned long pfn);
    3674             : extern void shake_page(struct page *p);
    3675             : extern atomic_long_t num_poisoned_pages __read_mostly;
    3676             : extern int soft_offline_page(unsigned long pfn, int flags);
    3677             : #ifdef CONFIG_MEMORY_FAILURE
    3678             : /*
    3679             :  * Sysfs entries for memory failure handling statistics.
    3680             :  */
    3681             : extern const struct attribute_group memory_failure_attr_group;
    3682             : extern void memory_failure_queue(unsigned long pfn, int flags);
    3683             : extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
    3684             :                                         bool *migratable_cleared);
    3685             : void num_poisoned_pages_inc(unsigned long pfn);
    3686             : void num_poisoned_pages_sub(unsigned long pfn, long i);
    3687             : struct task_struct *task_early_kill(struct task_struct *tsk, int force_early);
    3688             : #else
    3689             : static inline void memory_failure_queue(unsigned long pfn, int flags)
    3690             : {
    3691             : }
    3692             : 
    3693             : static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
    3694             :                                         bool *migratable_cleared)
    3695             : {
    3696             :         return 0;
    3697             : }
    3698             : 
    3699             : static inline void num_poisoned_pages_inc(unsigned long pfn)
    3700             : {
    3701             : }
    3702             : 
    3703             : static inline void num_poisoned_pages_sub(unsigned long pfn, long i)
    3704             : {
    3705             : }
    3706             : #endif
    3707             : 
    3708             : #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_KSM)
    3709             : void add_to_kill_ksm(struct task_struct *tsk, struct page *p,
    3710             :                      struct vm_area_struct *vma, struct list_head *to_kill,
    3711             :                      unsigned long ksm_addr);
    3712             : #endif
    3713             : 
    3714             : #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
    3715             : extern void memblk_nr_poison_inc(unsigned long pfn);
    3716             : extern void memblk_nr_poison_sub(unsigned long pfn, long i);
    3717             : #else
    3718             : static inline void memblk_nr_poison_inc(unsigned long pfn)
    3719             : {
    3720             : }
    3721             : 
    3722             : static inline void memblk_nr_poison_sub(unsigned long pfn, long i)
    3723             : {
    3724             : }
    3725             : #endif
    3726             : 
    3727             : #ifndef arch_memory_failure
    3728             : static inline int arch_memory_failure(unsigned long pfn, int flags)
    3729             : {
    3730             :         return -ENXIO;
    3731             : }
    3732             : #endif
    3733             : 
    3734             : #ifndef arch_is_platform_page
    3735             : static inline bool arch_is_platform_page(u64 paddr)
    3736             : {
    3737             :         return false;
    3738             : }
    3739             : #endif
    3740             : 
    3741             : /*
    3742             :  * Error handlers for various types of pages.
    3743             :  */
    3744             : enum mf_result {
    3745             :         MF_IGNORED,     /* Error: cannot be handled */
    3746             :         MF_FAILED,      /* Error: handling failed */
    3747             :         MF_DELAYED,     /* Will be handled later */
    3748             :         MF_RECOVERED,   /* Successfully recovered */
    3749             : };
    3750             : 
    3751             : enum mf_action_page_type {
    3752             :         MF_MSG_KERNEL,
    3753             :         MF_MSG_KERNEL_HIGH_ORDER,
    3754             :         MF_MSG_SLAB,
    3755             :         MF_MSG_DIFFERENT_COMPOUND,
    3756             :         MF_MSG_HUGE,
    3757             :         MF_MSG_FREE_HUGE,
    3758             :         MF_MSG_UNMAP_FAILED,
    3759             :         MF_MSG_DIRTY_SWAPCACHE,
    3760             :         MF_MSG_CLEAN_SWAPCACHE,
    3761             :         MF_MSG_DIRTY_MLOCKED_LRU,
    3762             :         MF_MSG_CLEAN_MLOCKED_LRU,
    3763             :         MF_MSG_DIRTY_UNEVICTABLE_LRU,
    3764             :         MF_MSG_CLEAN_UNEVICTABLE_LRU,
    3765             :         MF_MSG_DIRTY_LRU,
    3766             :         MF_MSG_CLEAN_LRU,
    3767             :         MF_MSG_TRUNCATED_LRU,
    3768             :         MF_MSG_BUDDY,
    3769             :         MF_MSG_DAX,
    3770             :         MF_MSG_UNSPLIT_THP,
    3771             :         MF_MSG_UNKNOWN,
    3772             : };
    3773             : 
    3774             : #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
    3775             : extern void clear_huge_page(struct page *page,
    3776             :                             unsigned long addr_hint,
    3777             :                             unsigned int pages_per_huge_page);
    3778             : int copy_user_large_folio(struct folio *dst, struct folio *src,
    3779             :                           unsigned long addr_hint,
    3780             :                           struct vm_area_struct *vma);
    3781             : long copy_folio_from_user(struct folio *dst_folio,
    3782             :                            const void __user *usr_src,
    3783             :                            bool allow_pagefault);
    3784             : 
    3785             : /**
    3786             :  * vma_is_special_huge - Are transhuge page-table entries considered special?
    3787             :  * @vma: Pointer to the struct vm_area_struct to consider
    3788             :  *
    3789             :  * Whether transhuge page-table entries are considered "special" following
    3790             :  * the definition in vm_normal_page().
    3791             :  *
    3792             :  * Return: true if transhuge page-table entries should be considered special,
    3793             :  * false otherwise.
    3794             :  */
    3795             : static inline bool vma_is_special_huge(const struct vm_area_struct *vma)
    3796             : {
    3797             :         return vma_is_dax(vma) || (vma->vm_file &&
    3798             :                                    (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)));
    3799             : }
    3800             : 
    3801             : #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
    3802             : 
    3803             : #if MAX_NUMNODES > 1
    3804             : void __init setup_nr_node_ids(void);
    3805             : #else
    3806             : static inline void setup_nr_node_ids(void) {}
    3807             : #endif
    3808             : 
    3809             : extern int memcmp_pages(struct page *page1, struct page *page2);
    3810             : 
    3811             : static inline int pages_identical(struct page *page1, struct page *page2)
    3812             : {
    3813             :         return !memcmp_pages(page1, page2);
    3814             : }
    3815             : 
    3816             : #ifdef CONFIG_MAPPING_DIRTY_HELPERS
    3817             : unsigned long clean_record_shared_mapping_range(struct address_space *mapping,
    3818             :                                                 pgoff_t first_index, pgoff_t nr,
    3819             :                                                 pgoff_t bitmap_pgoff,
    3820             :                                                 unsigned long *bitmap,
    3821             :                                                 pgoff_t *start,
    3822             :                                                 pgoff_t *end);
    3823             : 
    3824             : unsigned long wp_shared_mapping_range(struct address_space *mapping,
    3825             :                                       pgoff_t first_index, pgoff_t nr);
    3826             : #endif
    3827             : 
    3828             : extern int sysctl_nr_trim_pages;
    3829             : 
    3830             : #ifdef CONFIG_PRINTK
    3831             : void mem_dump_obj(void *object);
    3832             : #else
    3833             : static inline void mem_dump_obj(void *object) {}
    3834             : #endif
    3835             : 
    3836             : /**
    3837             :  * seal_check_future_write - Check for F_SEAL_FUTURE_WRITE flag and handle it
    3838             :  * @seals: the seals to check
    3839             :  * @vma: the vma to operate on
    3840             :  *
    3841             :  * Check whether F_SEAL_FUTURE_WRITE is set; if so, do proper check/handling on
    3842             :  * the vma flags.  Return 0 if check pass, or <0 for errors.
    3843             :  */
    3844             : static inline int seal_check_future_write(int seals, struct vm_area_struct *vma)
    3845             : {
    3846             :         if (seals & F_SEAL_FUTURE_WRITE) {
    3847             :                 /*
    3848             :                  * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
    3849             :                  * "future write" seal active.
    3850             :                  */
    3851             :                 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
    3852             :                         return -EPERM;
    3853             : 
    3854             :                 /*
    3855             :                  * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as
    3856             :                  * MAP_SHARED and read-only, take care to not allow mprotect to
    3857             :                  * revert protections on such mappings. Do this only for shared
    3858             :                  * mappings. For private mappings, don't need to mask
    3859             :                  * VM_MAYWRITE as we still want them to be COW-writable.
    3860             :                  */
    3861             :                 if (vma->vm_flags & VM_SHARED)
    3862             :                         vm_flags_clear(vma, VM_MAYWRITE);
    3863             :         }
    3864             : 
    3865             :         return 0;
    3866             : }
    3867             : 
    3868             : #ifdef CONFIG_ANON_VMA_NAME
    3869             : int madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
    3870             :                           unsigned long len_in,
    3871             :                           struct anon_vma_name *anon_name);
    3872             : #else
    3873             : static inline int
    3874             : madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
    3875             :                       unsigned long len_in, struct anon_vma_name *anon_name) {
    3876             :         return 0;
    3877             : }
    3878             : #endif
    3879             : 
    3880             : #ifdef CONFIG_UNACCEPTED_MEMORY
    3881             : 
    3882             : bool range_contains_unaccepted_memory(phys_addr_t start, phys_addr_t end);
    3883             : void accept_memory(phys_addr_t start, phys_addr_t end);
    3884             : 
    3885             : #else
    3886             : 
    3887             : static inline bool range_contains_unaccepted_memory(phys_addr_t start,
    3888             :                                                     phys_addr_t end)
    3889             : {
    3890             :         return false;
    3891             : }
    3892             : 
    3893             : static inline void accept_memory(phys_addr_t start, phys_addr_t end)
    3894             : {
    3895             : }
    3896             : 
    3897             : #endif
    3898             : 
    3899             : #endif /* _LINUX_MM_H */

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