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Linux/include/linux/mm.h

  1 #ifndef _LINUX_MM_H
  2 #define _LINUX_MM_H
  3 
  4 #include <linux/errno.h>
  5 
  6 #ifdef __KERNEL__
  7 
  8 #include <linux/mmdebug.h>
  9 #include <linux/gfp.h>
 10 #include <linux/bug.h>
 11 #include <linux/list.h>
 12 #include <linux/mmzone.h>
 13 #include <linux/rbtree.h>
 14 #include <linux/atomic.h>
 15 #include <linux/debug_locks.h>
 16 #include <linux/mm_types.h>
 17 #include <linux/range.h>
 18 #include <linux/pfn.h>
 19 #include <linux/percpu-refcount.h>
 20 #include <linux/bit_spinlock.h>
 21 #include <linux/shrinker.h>
 22 #include <linux/resource.h>
 23 #include <linux/page_ext.h>
 24 #include <linux/err.h>
 25 #include <linux/page_ref.h>
 26 
 27 struct mempolicy;
 28 struct anon_vma;
 29 struct anon_vma_chain;
 30 struct file_ra_state;
 31 struct user_struct;
 32 struct writeback_control;
 33 struct bdi_writeback;
 34 
 35 #ifndef CONFIG_NEED_MULTIPLE_NODES      /* Don't use mapnrs, do it properly */
 36 extern unsigned long max_mapnr;
 37 
 38 static inline void set_max_mapnr(unsigned long limit)
 39 {
 40         max_mapnr = limit;
 41 }
 42 #else
 43 static inline void set_max_mapnr(unsigned long limit) { }
 44 #endif
 45 
 46 extern unsigned long totalram_pages;
 47 extern void * high_memory;
 48 extern int page_cluster;
 49 
 50 #ifdef CONFIG_SYSCTL
 51 extern int sysctl_legacy_va_layout;
 52 #else
 53 #define sysctl_legacy_va_layout 0
 54 #endif
 55 
 56 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
 57 extern const int mmap_rnd_bits_min;
 58 extern const int mmap_rnd_bits_max;
 59 extern int mmap_rnd_bits __read_mostly;
 60 #endif
 61 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
 62 extern const int mmap_rnd_compat_bits_min;
 63 extern const int mmap_rnd_compat_bits_max;
 64 extern int mmap_rnd_compat_bits __read_mostly;
 65 #endif
 66 
 67 #include <asm/page.h>
 68 #include <asm/pgtable.h>
 69 #include <asm/processor.h>
 70 
 71 #ifndef __pa_symbol
 72 #define __pa_symbol(x)  __pa(RELOC_HIDE((unsigned long)(x), 0))
 73 #endif
 74 
 75 #ifndef page_to_virt
 76 #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x)))
 77 #endif
 78 
 79 /*
 80  * To prevent common memory management code establishing
 81  * a zero page mapping on a read fault.
 82  * This macro should be defined within <asm/pgtable.h>.
 83  * s390 does this to prevent multiplexing of hardware bits
 84  * related to the physical page in case of virtualization.
 85  */
 86 #ifndef mm_forbids_zeropage
 87 #define mm_forbids_zeropage(X)  (0)
 88 #endif
 89 
 90 /*
 91  * Default maximum number of active map areas, this limits the number of vmas
 92  * per mm struct. Users can overwrite this number by sysctl but there is a
 93  * problem.
 94  *
 95  * When a program's coredump is generated as ELF format, a section is created
 96  * per a vma. In ELF, the number of sections is represented in unsigned short.
 97  * This means the number of sections should be smaller than 65535 at coredump.
 98  * Because the kernel adds some informative sections to a image of program at
 99  * generating coredump, we need some margin. The number of extra sections is
100  * 1-3 now and depends on arch. We use "5" as safe margin, here.
101  *
102  * ELF extended numbering allows more than 65535 sections, so 16-bit bound is
103  * not a hard limit any more. Although some userspace tools can be surprised by
104  * that.
105  */
106 #define MAPCOUNT_ELF_CORE_MARGIN        (5)
107 #define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
108 
109 extern int sysctl_max_map_count;
110 
111 extern unsigned long sysctl_user_reserve_kbytes;
112 extern unsigned long sysctl_admin_reserve_kbytes;
113 
114 extern int sysctl_overcommit_memory;
115 extern int sysctl_overcommit_ratio;
116 extern unsigned long sysctl_overcommit_kbytes;
117 
118 extern int overcommit_ratio_handler(struct ctl_table *, int, void __user *,
119                                     size_t *, loff_t *);
120 extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
121                                     size_t *, loff_t *);
122 
123 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
124 
125 /* to align the pointer to the (next) page boundary */
126 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
127 
128 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
129 #define PAGE_ALIGNED(addr)      IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
130 
131 /*
132  * Linux kernel virtual memory manager primitives.
133  * The idea being to have a "virtual" mm in the same way
134  * we have a virtual fs - giving a cleaner interface to the
135  * mm details, and allowing different kinds of memory mappings
136  * (from shared memory to executable loading to arbitrary
137  * mmap() functions).
138  */
139 
140 extern struct kmem_cache *vm_area_cachep;
141 
142 #ifndef CONFIG_MMU
143 extern struct rb_root nommu_region_tree;
144 extern struct rw_semaphore nommu_region_sem;
145 
146 extern unsigned int kobjsize(const void *objp);
147 #endif
148 
149 /*
150  * vm_flags in vm_area_struct, see mm_types.h.
151  * When changing, update also include/trace/events/mmflags.h
152  */
153 #define VM_NONE         0x00000000
154 
155 #define VM_READ         0x00000001      /* currently active flags */
156 #define VM_WRITE        0x00000002
157 #define VM_EXEC         0x00000004
158 #define VM_SHARED       0x00000008
159 
160 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
161 #define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
162 #define VM_MAYWRITE     0x00000020
163 #define VM_MAYEXEC      0x00000040
164 #define VM_MAYSHARE     0x00000080
165 
166 #define VM_GROWSDOWN    0x00000100      /* general info on the segment */
167 #define VM_UFFD_MISSING 0x00000200      /* missing pages tracking */
168 #define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
169 #define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
170 #define VM_UFFD_WP      0x00001000      /* wrprotect pages tracking */
171 
172 #define VM_LOCKED       0x00002000
173 #define VM_IO           0x00004000      /* Memory mapped I/O or similar */
174 
175                                         /* Used by sys_madvise() */
176 #define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
177 #define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
178 
179 #define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
180 #define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
181 #define VM_LOCKONFAULT  0x00080000      /* Lock the pages covered when they are faulted in */
182 #define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
183 #define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
184 #define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
185 #define VM_ARCH_1       0x01000000      /* Architecture-specific flag */
186 #define VM_ARCH_2       0x02000000
187 #define VM_DONTDUMP     0x04000000      /* Do not include in the core dump */
188 
189 #ifdef CONFIG_MEM_SOFT_DIRTY
190 # define VM_SOFTDIRTY   0x08000000      /* Not soft dirty clean area */
191 #else
192 # define VM_SOFTDIRTY   0
193 #endif
194 
195 #define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
196 #define VM_HUGEPAGE     0x20000000      /* MADV_HUGEPAGE marked this vma */
197 #define VM_NOHUGEPAGE   0x40000000      /* MADV_NOHUGEPAGE marked this vma */
198 #define VM_MERGEABLE    0x80000000      /* KSM may merge identical pages */
199 
200 #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
201 #define VM_HIGH_ARCH_BIT_0      32      /* bit only usable on 64-bit architectures */
202 #define VM_HIGH_ARCH_BIT_1      33      /* bit only usable on 64-bit architectures */
203 #define VM_HIGH_ARCH_BIT_2      34      /* bit only usable on 64-bit architectures */
204 #define VM_HIGH_ARCH_BIT_3      35      /* bit only usable on 64-bit architectures */
205 #define VM_HIGH_ARCH_0  BIT(VM_HIGH_ARCH_BIT_0)
206 #define VM_HIGH_ARCH_1  BIT(VM_HIGH_ARCH_BIT_1)
207 #define VM_HIGH_ARCH_2  BIT(VM_HIGH_ARCH_BIT_2)
208 #define VM_HIGH_ARCH_3  BIT(VM_HIGH_ARCH_BIT_3)
209 #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
210 
211 #if defined(CONFIG_X86)
212 # define VM_PAT         VM_ARCH_1       /* PAT reserves whole VMA at once (x86) */
213 #if defined (CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS)
214 # define VM_PKEY_SHIFT  VM_HIGH_ARCH_BIT_0
215 # define VM_PKEY_BIT0   VM_HIGH_ARCH_0  /* A protection key is a 4-bit value */
216 # define VM_PKEY_BIT1   VM_HIGH_ARCH_1
217 # define VM_PKEY_BIT2   VM_HIGH_ARCH_2
218 # define VM_PKEY_BIT3   VM_HIGH_ARCH_3
219 #endif
220 #elif defined(CONFIG_PPC)
221 # define VM_SAO         VM_ARCH_1       /* Strong Access Ordering (powerpc) */
222 #elif defined(CONFIG_PARISC)
223 # define VM_GROWSUP     VM_ARCH_1
224 #elif defined(CONFIG_METAG)
225 # define VM_GROWSUP     VM_ARCH_1
226 #elif defined(CONFIG_IA64)
227 # define VM_GROWSUP     VM_ARCH_1
228 #elif !defined(CONFIG_MMU)
229 # define VM_MAPPED_COPY VM_ARCH_1       /* T if mapped copy of data (nommu mmap) */
230 #endif
231 
232 #if defined(CONFIG_X86)
233 /* MPX specific bounds table or bounds directory */
234 # define VM_MPX         VM_ARCH_2
235 #endif
236 
237 #ifndef VM_GROWSUP
238 # define VM_GROWSUP     VM_NONE
239 #endif
240 
241 /* Bits set in the VMA until the stack is in its final location */
242 #define VM_STACK_INCOMPLETE_SETUP       (VM_RAND_READ | VM_SEQ_READ)
243 
244 #ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
245 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
246 #endif
247 
248 #ifdef CONFIG_STACK_GROWSUP
249 #define VM_STACK        VM_GROWSUP
250 #else
251 #define VM_STACK        VM_GROWSDOWN
252 #endif
253 
254 #define VM_STACK_FLAGS  (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
255 
256 /*
257  * Special vmas that are non-mergable, non-mlock()able.
258  * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
259  */
260 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
261 
262 /* This mask defines which mm->def_flags a process can inherit its parent */
263 #define VM_INIT_DEF_MASK        VM_NOHUGEPAGE
264 
265 /* This mask is used to clear all the VMA flags used by mlock */
266 #define VM_LOCKED_CLEAR_MASK    (~(VM_LOCKED | VM_LOCKONFAULT))
267 
268 /*
269  * mapping from the currently active vm_flags protection bits (the
270  * low four bits) to a page protection mask..
271  */
272 extern pgprot_t protection_map[16];
273 
274 #define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
275 #define FAULT_FLAG_MKWRITE      0x02    /* Fault was mkwrite of existing pte */
276 #define FAULT_FLAG_ALLOW_RETRY  0x04    /* Retry fault if blocking */
277 #define FAULT_FLAG_RETRY_NOWAIT 0x08    /* Don't drop mmap_sem and wait when retrying */
278 #define FAULT_FLAG_KILLABLE     0x10    /* The fault task is in SIGKILL killable region */
279 #define FAULT_FLAG_TRIED        0x20    /* Second try */
280 #define FAULT_FLAG_USER         0x40    /* The fault originated in userspace */
281 #define FAULT_FLAG_REMOTE       0x80    /* faulting for non current tsk/mm */
282 #define FAULT_FLAG_INSTRUCTION  0x100   /* The fault was during an instruction fetch */
283 
284 /*
285  * vm_fault is filled by the the pagefault handler and passed to the vma's
286  * ->fault function. The vma's ->fault is responsible for returning a bitmask
287  * of VM_FAULT_xxx flags that give details about how the fault was handled.
288  *
289  * MM layer fills up gfp_mask for page allocations but fault handler might
290  * alter it if its implementation requires a different allocation context.
291  *
292  * pgoff should be used in favour of virtual_address, if possible.
293  */
294 struct vm_fault {
295         unsigned int flags;             /* FAULT_FLAG_xxx flags */
296         gfp_t gfp_mask;                 /* gfp mask to be used for allocations */
297         pgoff_t pgoff;                  /* Logical page offset based on vma */
298         void __user *virtual_address;   /* Faulting virtual address */
299 
300         struct page *cow_page;          /* Handler may choose to COW */
301         struct page *page;              /* ->fault handlers should return a
302                                          * page here, unless VM_FAULT_NOPAGE
303                                          * is set (which is also implied by
304                                          * VM_FAULT_ERROR).
305                                          */
306         void *entry;                    /* ->fault handler can alternatively
307                                          * return locked DAX entry. In that
308                                          * case handler should return
309                                          * VM_FAULT_DAX_LOCKED and fill in
310                                          * entry here.
311                                          */
312 };
313 
314 /*
315  * Page fault context: passes though page fault handler instead of endless list
316  * of function arguments.
317  */
318 struct fault_env {
319         struct vm_area_struct *vma;     /* Target VMA */
320         unsigned long address;          /* Faulting virtual address */
321         unsigned int flags;             /* FAULT_FLAG_xxx flags */
322         pmd_t *pmd;                     /* Pointer to pmd entry matching
323                                          * the 'address'
324                                          */
325         pte_t *pte;                     /* Pointer to pte entry matching
326                                          * the 'address'. NULL if the page
327                                          * table hasn't been allocated.
328                                          */
329         spinlock_t *ptl;                /* Page table lock.
330                                          * Protects pte page table if 'pte'
331                                          * is not NULL, otherwise pmd.
332                                          */
333         pgtable_t prealloc_pte;         /* Pre-allocated pte page table.
334                                          * vm_ops->map_pages() calls
335                                          * alloc_set_pte() from atomic context.
336                                          * do_fault_around() pre-allocates
337                                          * page table to avoid allocation from
338                                          * atomic context.
339                                          */
340 };
341 
342 /*
343  * These are the virtual MM functions - opening of an area, closing and
344  * unmapping it (needed to keep files on disk up-to-date etc), pointer
345  * to the functions called when a no-page or a wp-page exception occurs. 
346  */
347 struct vm_operations_struct {
348         void (*open)(struct vm_area_struct * area);
349         void (*close)(struct vm_area_struct * area);
350         int (*mremap)(struct vm_area_struct * area);
351         int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
352         int (*pmd_fault)(struct vm_area_struct *, unsigned long address,
353                                                 pmd_t *, unsigned int flags);
354         void (*map_pages)(struct fault_env *fe,
355                         pgoff_t start_pgoff, pgoff_t end_pgoff);
356 
357         /* notification that a previously read-only page is about to become
358          * writable, if an error is returned it will cause a SIGBUS */
359         int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
360 
361         /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */
362         int (*pfn_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
363 
364         /* called by access_process_vm when get_user_pages() fails, typically
365          * for use by special VMAs that can switch between memory and hardware
366          */
367         int (*access)(struct vm_area_struct *vma, unsigned long addr,
368                       void *buf, int len, int write);
369 
370         /* Called by the /proc/PID/maps code to ask the vma whether it
371          * has a special name.  Returning non-NULL will also cause this
372          * vma to be dumped unconditionally. */
373         const char *(*name)(struct vm_area_struct *vma);
374 
375 #ifdef CONFIG_NUMA
376         /*
377          * set_policy() op must add a reference to any non-NULL @new mempolicy
378          * to hold the policy upon return.  Caller should pass NULL @new to
379          * remove a policy and fall back to surrounding context--i.e. do not
380          * install a MPOL_DEFAULT policy, nor the task or system default
381          * mempolicy.
382          */
383         int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
384 
385         /*
386          * get_policy() op must add reference [mpol_get()] to any policy at
387          * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
388          * in mm/mempolicy.c will do this automatically.
389          * get_policy() must NOT add a ref if the policy at (vma,addr) is not
390          * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
391          * If no [shared/vma] mempolicy exists at the addr, get_policy() op
392          * must return NULL--i.e., do not "fallback" to task or system default
393          * policy.
394          */
395         struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
396                                         unsigned long addr);
397 #endif
398         /*
399          * Called by vm_normal_page() for special PTEs to find the
400          * page for @addr.  This is useful if the default behavior
401          * (using pte_page()) would not find the correct page.
402          */
403         struct page *(*find_special_page)(struct vm_area_struct *vma,
404                                           unsigned long addr);
405 };
406 
407 struct mmu_gather;
408 struct inode;
409 
410 #define page_private(page)              ((page)->private)
411 #define set_page_private(page, v)       ((page)->private = (v))
412 
413 #if !defined(__HAVE_ARCH_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
414 static inline int pmd_devmap(pmd_t pmd)
415 {
416         return 0;
417 }
418 #endif
419 
420 /*
421  * FIXME: take this include out, include page-flags.h in
422  * files which need it (119 of them)
423  */
424 #include <linux/page-flags.h>
425 #include <linux/huge_mm.h>
426 
427 /*
428  * Methods to modify the page usage count.
429  *
430  * What counts for a page usage:
431  * - cache mapping   (page->mapping)
432  * - private data    (page->private)
433  * - page mapped in a task's page tables, each mapping
434  *   is counted separately
435  *
436  * Also, many kernel routines increase the page count before a critical
437  * routine so they can be sure the page doesn't go away from under them.
438  */
439 
440 /*
441  * Drop a ref, return true if the refcount fell to zero (the page has no users)
442  */
443 static inline int put_page_testzero(struct page *page)
444 {
445         VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
446         return page_ref_dec_and_test(page);
447 }
448 
449 /*
450  * Try to grab a ref unless the page has a refcount of zero, return false if
451  * that is the case.
452  * This can be called when MMU is off so it must not access
453  * any of the virtual mappings.
454  */
455 static inline int get_page_unless_zero(struct page *page)
456 {
457         return page_ref_add_unless(page, 1, 0);
458 }
459 
460 extern int page_is_ram(unsigned long pfn);
461 
462 enum {
463         REGION_INTERSECTS,
464         REGION_DISJOINT,
465         REGION_MIXED,
466 };
467 
468 int region_intersects(resource_size_t offset, size_t size, unsigned long flags,
469                       unsigned long desc);
470 
471 /* Support for virtually mapped pages */
472 struct page *vmalloc_to_page(const void *addr);
473 unsigned long vmalloc_to_pfn(const void *addr);
474 
475 /*
476  * Determine if an address is within the vmalloc range
477  *
478  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
479  * is no special casing required.
480  */
481 static inline bool is_vmalloc_addr(const void *x)
482 {
483 #ifdef CONFIG_MMU
484         unsigned long addr = (unsigned long)x;
485 
486         return addr >= VMALLOC_START && addr < VMALLOC_END;
487 #else
488         return false;
489 #endif
490 }
491 #ifdef CONFIG_MMU
492 extern int is_vmalloc_or_module_addr(const void *x);
493 #else
494 static inline int is_vmalloc_or_module_addr(const void *x)
495 {
496         return 0;
497 }
498 #endif
499 
500 extern void kvfree(const void *addr);
501 
502 static inline atomic_t *compound_mapcount_ptr(struct page *page)
503 {
504         return &page[1].compound_mapcount;
505 }
506 
507 static inline int compound_mapcount(struct page *page)
508 {
509         VM_BUG_ON_PAGE(!PageCompound(page), page);
510         page = compound_head(page);
511         return atomic_read(compound_mapcount_ptr(page)) + 1;
512 }
513 
514 /*
515  * The atomic page->_mapcount, starts from -1: so that transitions
516  * both from it and to it can be tracked, using atomic_inc_and_test
517  * and atomic_add_negative(-1).
518  */
519 static inline void page_mapcount_reset(struct page *page)
520 {
521         atomic_set(&(page)->_mapcount, -1);
522 }
523 
524 int __page_mapcount(struct page *page);
525 
526 static inline int page_mapcount(struct page *page)
527 {
528         VM_BUG_ON_PAGE(PageSlab(page), page);
529 
530         if (unlikely(PageCompound(page)))
531                 return __page_mapcount(page);
532         return atomic_read(&page->_mapcount) + 1;
533 }
534 
535 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
536 int total_mapcount(struct page *page);
537 int page_trans_huge_mapcount(struct page *page, int *total_mapcount);
538 #else
539 static inline int total_mapcount(struct page *page)
540 {
541         return page_mapcount(page);
542 }
543 static inline int page_trans_huge_mapcount(struct page *page,
544                                            int *total_mapcount)
545 {
546         int mapcount = page_mapcount(page);
547         if (total_mapcount)
548                 *total_mapcount = mapcount;
549         return mapcount;
550 }
551 #endif
552 
553 static inline struct page *virt_to_head_page(const void *x)
554 {
555         struct page *page = virt_to_page(x);
556 
557         return compound_head(page);
558 }
559 
560 void __put_page(struct page *page);
561 
562 void put_pages_list(struct list_head *pages);
563 
564 void split_page(struct page *page, unsigned int order);
565 
566 /*
567  * Compound pages have a destructor function.  Provide a
568  * prototype for that function and accessor functions.
569  * These are _only_ valid on the head of a compound page.
570  */
571 typedef void compound_page_dtor(struct page *);
572 
573 /* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */
574 enum compound_dtor_id {
575         NULL_COMPOUND_DTOR,
576         COMPOUND_PAGE_DTOR,
577 #ifdef CONFIG_HUGETLB_PAGE
578         HUGETLB_PAGE_DTOR,
579 #endif
580 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
581         TRANSHUGE_PAGE_DTOR,
582 #endif
583         NR_COMPOUND_DTORS,
584 };
585 extern compound_page_dtor * const compound_page_dtors[];
586 
587 static inline void set_compound_page_dtor(struct page *page,
588                 enum compound_dtor_id compound_dtor)
589 {
590         VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page);
591         page[1].compound_dtor = compound_dtor;
592 }
593 
594 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
595 {
596         VM_BUG_ON_PAGE(page[1].compound_dtor >= NR_COMPOUND_DTORS, page);
597         return compound_page_dtors[page[1].compound_dtor];
598 }
599 
600 static inline unsigned int compound_order(struct page *page)
601 {
602         if (!PageHead(page))
603                 return 0;
604         return page[1].compound_order;
605 }
606 
607 static inline void set_compound_order(struct page *page, unsigned int order)
608 {
609         page[1].compound_order = order;
610 }
611 
612 void free_compound_page(struct page *page);
613 
614 #ifdef CONFIG_MMU
615 /*
616  * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
617  * servicing faults for write access.  In the normal case, do always want
618  * pte_mkwrite.  But get_user_pages can cause write faults for mappings
619  * that do not have writing enabled, when used by access_process_vm.
620  */
621 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
622 {
623         if (likely(vma->vm_flags & VM_WRITE))
624                 pte = pte_mkwrite(pte);
625         return pte;
626 }
627 
628 int alloc_set_pte(struct fault_env *fe, struct mem_cgroup *memcg,
629                 struct page *page);
630 #endif
631 
632 /*
633  * Multiple processes may "see" the same page. E.g. for untouched
634  * mappings of /dev/null, all processes see the same page full of
635  * zeroes, and text pages of executables and shared libraries have
636  * only one copy in memory, at most, normally.
637  *
638  * For the non-reserved pages, page_count(page) denotes a reference count.
639  *   page_count() == 0 means the page is free. page->lru is then used for
640  *   freelist management in the buddy allocator.
641  *   page_count() > 0  means the page has been allocated.
642  *
643  * Pages are allocated by the slab allocator in order to provide memory
644  * to kmalloc and kmem_cache_alloc. In this case, the management of the
645  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
646  * unless a particular usage is carefully commented. (the responsibility of
647  * freeing the kmalloc memory is the caller's, of course).
648  *
649  * A page may be used by anyone else who does a __get_free_page().
650  * In this case, page_count still tracks the references, and should only
651  * be used through the normal accessor functions. The top bits of page->flags
652  * and page->virtual store page management information, but all other fields
653  * are unused and could be used privately, carefully. The management of this
654  * page is the responsibility of the one who allocated it, and those who have
655  * subsequently been given references to it.
656  *
657  * The other pages (we may call them "pagecache pages") are completely
658  * managed by the Linux memory manager: I/O, buffers, swapping etc.
659  * The following discussion applies only to them.
660  *
661  * A pagecache page contains an opaque `private' member, which belongs to the
662  * page's address_space. Usually, this is the address of a circular list of
663  * the page's disk buffers. PG_private must be set to tell the VM to call
664  * into the filesystem to release these pages.
665  *
666  * A page may belong to an inode's memory mapping. In this case, page->mapping
667  * is the pointer to the inode, and page->index is the file offset of the page,
668  * in units of PAGE_SIZE.
669  *
670  * If pagecache pages are not associated with an inode, they are said to be
671  * anonymous pages. These may become associated with the swapcache, and in that
672  * case PG_swapcache is set, and page->private is an offset into the swapcache.
673  *
674  * In either case (swapcache or inode backed), the pagecache itself holds one
675  * reference to the page. Setting PG_private should also increment the
676  * refcount. The each user mapping also has a reference to the page.
677  *
678  * The pagecache pages are stored in a per-mapping radix tree, which is
679  * rooted at mapping->page_tree, and indexed by offset.
680  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
681  * lists, we instead now tag pages as dirty/writeback in the radix tree.
682  *
683  * All pagecache pages may be subject to I/O:
684  * - inode pages may need to be read from disk,
685  * - inode pages which have been modified and are MAP_SHARED may need
686  *   to be written back to the inode on disk,
687  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
688  *   modified may need to be swapped out to swap space and (later) to be read
689  *   back into memory.
690  */
691 
692 /*
693  * The zone field is never updated after free_area_init_core()
694  * sets it, so none of the operations on it need to be atomic.
695  */
696 
697 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
698 #define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
699 #define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
700 #define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
701 #define LAST_CPUPID_PGOFF       (ZONES_PGOFF - LAST_CPUPID_WIDTH)
702 
703 /*
704  * Define the bit shifts to access each section.  For non-existent
705  * sections we define the shift as 0; that plus a 0 mask ensures
706  * the compiler will optimise away reference to them.
707  */
708 #define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
709 #define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
710 #define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
711 #define LAST_CPUPID_PGSHIFT     (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
712 
713 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
714 #ifdef NODE_NOT_IN_PAGE_FLAGS
715 #define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
716 #define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
717                                                 SECTIONS_PGOFF : ZONES_PGOFF)
718 #else
719 #define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
720 #define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
721                                                 NODES_PGOFF : ZONES_PGOFF)
722 #endif
723 
724 #define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
725 
726 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
727 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
728 #endif
729 
730 #define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
731 #define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
732 #define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
733 #define LAST_CPUPID_MASK        ((1UL << LAST_CPUPID_SHIFT) - 1)
734 #define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
735 
736 static inline enum zone_type page_zonenum(const struct page *page)
737 {
738         return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
739 }
740 
741 #ifdef CONFIG_ZONE_DEVICE
742 void get_zone_device_page(struct page *page);
743 void put_zone_device_page(struct page *page);
744 static inline bool is_zone_device_page(const struct page *page)
745 {
746         return page_zonenum(page) == ZONE_DEVICE;
747 }
748 #else
749 static inline void get_zone_device_page(struct page *page)
750 {
751 }
752 static inline void put_zone_device_page(struct page *page)
753 {
754 }
755 static inline bool is_zone_device_page(const struct page *page)
756 {
757         return false;
758 }
759 #endif
760 
761 static inline void get_page(struct page *page)
762 {
763         page = compound_head(page);
764         /*
765          * Getting a normal page or the head of a compound page
766          * requires to already have an elevated page->_refcount.
767          */
768         VM_BUG_ON_PAGE(page_ref_count(page) <= 0, page);
769         page_ref_inc(page);
770 
771         if (unlikely(is_zone_device_page(page)))
772                 get_zone_device_page(page);
773 }
774 
775 static inline void put_page(struct page *page)
776 {
777         page = compound_head(page);
778 
779         if (put_page_testzero(page))
780                 __put_page(page);
781 
782         if (unlikely(is_zone_device_page(page)))
783                 put_zone_device_page(page);
784 }
785 
786 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
787 #define SECTION_IN_PAGE_FLAGS
788 #endif
789 
790 /*
791  * The identification function is mainly used by the buddy allocator for
792  * determining if two pages could be buddies. We are not really identifying
793  * the zone since we could be using the section number id if we do not have
794  * node id available in page flags.
795  * We only guarantee that it will return the same value for two combinable
796  * pages in a zone.
797  */
798 static inline int page_zone_id(struct page *page)
799 {
800         return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
801 }
802 
803 static inline int zone_to_nid(struct zone *zone)
804 {
805 #ifdef CONFIG_NUMA
806         return zone->node;
807 #else
808         return 0;
809 #endif
810 }
811 
812 #ifdef NODE_NOT_IN_PAGE_FLAGS
813 extern int page_to_nid(const struct page *page);
814 #else
815 static inline int page_to_nid(const struct page *page)
816 {
817         return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
818 }
819 #endif
820 
821 #ifdef CONFIG_NUMA_BALANCING
822 static inline int cpu_pid_to_cpupid(int cpu, int pid)
823 {
824         return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
825 }
826 
827 static inline int cpupid_to_pid(int cpupid)
828 {
829         return cpupid & LAST__PID_MASK;
830 }
831 
832 static inline int cpupid_to_cpu(int cpupid)
833 {
834         return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
835 }
836 
837 static inline int cpupid_to_nid(int cpupid)
838 {
839         return cpu_to_node(cpupid_to_cpu(cpupid));
840 }
841 
842 static inline bool cpupid_pid_unset(int cpupid)
843 {
844         return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
845 }
846 
847 static inline bool cpupid_cpu_unset(int cpupid)
848 {
849         return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
850 }
851 
852 static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
853 {
854         return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
855 }
856 
857 #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
858 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
859 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
860 {
861         return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
862 }
863 
864 static inline int page_cpupid_last(struct page *page)
865 {
866         return page->_last_cpupid;
867 }
868 static inline void page_cpupid_reset_last(struct page *page)
869 {
870         page->_last_cpupid = -1 & LAST_CPUPID_MASK;
871 }
872 #else
873 static inline int page_cpupid_last(struct page *page)
874 {
875         return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
876 }
877 
878 extern int page_cpupid_xchg_last(struct page *page, int cpupid);
879 
880 static inline void page_cpupid_reset_last(struct page *page)
881 {
882         page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
883 }
884 #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
885 #else /* !CONFIG_NUMA_BALANCING */
886 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
887 {
888         return page_to_nid(page); /* XXX */
889 }
890 
891 static inline int page_cpupid_last(struct page *page)
892 {
893         return page_to_nid(page); /* XXX */
894 }
895 
896 static inline int cpupid_to_nid(int cpupid)
897 {
898         return -1;
899 }
900 
901 static inline int cpupid_to_pid(int cpupid)
902 {
903         return -1;
904 }
905 
906 static inline int cpupid_to_cpu(int cpupid)
907 {
908         return -1;
909 }
910 
911 static inline int cpu_pid_to_cpupid(int nid, int pid)
912 {
913         return -1;
914 }
915 
916 static inline bool cpupid_pid_unset(int cpupid)
917 {
918         return 1;
919 }
920 
921 static inline void page_cpupid_reset_last(struct page *page)
922 {
923 }
924 
925 static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
926 {
927         return false;
928 }
929 #endif /* CONFIG_NUMA_BALANCING */
930 
931 static inline struct zone *page_zone(const struct page *page)
932 {
933         return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
934 }
935 
936 static inline pg_data_t *page_pgdat(const struct page *page)
937 {
938         return NODE_DATA(page_to_nid(page));
939 }
940 
941 #ifdef SECTION_IN_PAGE_FLAGS
942 static inline void set_page_section(struct page *page, unsigned long section)
943 {
944         page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
945         page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
946 }
947 
948 static inline unsigned long page_to_section(const struct page *page)
949 {
950         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
951 }
952 #endif
953 
954 static inline void set_page_zone(struct page *page, enum zone_type zone)
955 {
956         page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
957         page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
958 }
959 
960 static inline void set_page_node(struct page *page, unsigned long node)
961 {
962         page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
963         page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
964 }
965 
966 static inline void set_page_links(struct page *page, enum zone_type zone,
967         unsigned long node, unsigned long pfn)
968 {
969         set_page_zone(page, zone);
970         set_page_node(page, node);
971 #ifdef SECTION_IN_PAGE_FLAGS
972         set_page_section(page, pfn_to_section_nr(pfn));
973 #endif
974 }
975 
976 #ifdef CONFIG_MEMCG
977 static inline struct mem_cgroup *page_memcg(struct page *page)
978 {
979         return page->mem_cgroup;
980 }
981 static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
982 {
983         WARN_ON_ONCE(!rcu_read_lock_held());
984         return READ_ONCE(page->mem_cgroup);
985 }
986 #else
987 static inline struct mem_cgroup *page_memcg(struct page *page)
988 {
989         return NULL;
990 }
991 static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
992 {
993         WARN_ON_ONCE(!rcu_read_lock_held());
994         return NULL;
995 }
996 #endif
997 
998 /*
999  * Some inline functions in vmstat.h depend on page_zone()
1000  */
1001 #include <linux/vmstat.h>
1002 
1003 static __always_inline void *lowmem_page_address(const struct page *page)
1004 {
1005         return page_to_virt(page);
1006 }
1007 
1008 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
1009 #define HASHED_PAGE_VIRTUAL
1010 #endif
1011 
1012 #if defined(WANT_PAGE_VIRTUAL)
1013 static inline void *page_address(const struct page *page)
1014 {
1015         return page->virtual;
1016 }
1017 static inline void set_page_address(struct page *page, void *address)
1018 {
1019         page->virtual = address;
1020 }
1021 #define page_address_init()  do { } while(0)
1022 #endif
1023 
1024 #if defined(HASHED_PAGE_VIRTUAL)
1025 void *page_address(const struct page *page);
1026 void set_page_address(struct page *page, void *virtual);
1027 void page_address_init(void);
1028 #endif
1029 
1030 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
1031 #define page_address(page) lowmem_page_address(page)
1032 #define set_page_address(page, address)  do { } while(0)
1033 #define page_address_init()  do { } while(0)
1034 #endif
1035 
1036 extern void *page_rmapping(struct page *page);
1037 extern struct anon_vma *page_anon_vma(struct page *page);
1038 extern struct address_space *page_mapping(struct page *page);
1039 
1040 extern struct address_space *__page_file_mapping(struct page *);
1041 
1042 static inline
1043 struct address_space *page_file_mapping(struct page *page)
1044 {
1045         if (unlikely(PageSwapCache(page)))
1046                 return __page_file_mapping(page);
1047 
1048         return page->mapping;
1049 }
1050 
1051 extern pgoff_t __page_file_index(struct page *page);
1052 
1053 /*
1054  * Return the pagecache index of the passed page.  Regular pagecache pages
1055  * use ->index whereas swapcache pages use swp_offset(->private)
1056  */
1057 static inline pgoff_t page_index(struct page *page)
1058 {
1059         if (unlikely(PageSwapCache(page)))
1060                 return __page_file_index(page);
1061         return page->index;
1062 }
1063 
1064 bool page_mapped(struct page *page);
1065 struct address_space *page_mapping(struct page *page);
1066 
1067 /*
1068  * Return true only if the page has been allocated with
1069  * ALLOC_NO_WATERMARKS and the low watermark was not
1070  * met implying that the system is under some pressure.
1071  */
1072 static inline bool page_is_pfmemalloc(struct page *page)
1073 {
1074         /*
1075          * Page index cannot be this large so this must be
1076          * a pfmemalloc page.
1077          */
1078         return page->index == -1UL;
1079 }
1080 
1081 /*
1082  * Only to be called by the page allocator on a freshly allocated
1083  * page.
1084  */
1085 static inline void set_page_pfmemalloc(struct page *page)
1086 {
1087         page->index = -1UL;
1088 }
1089 
1090 static inline void clear_page_pfmemalloc(struct page *page)
1091 {
1092         page->index = 0;
1093 }
1094 
1095 /*
1096  * Different kinds of faults, as returned by handle_mm_fault().
1097  * Used to decide whether a process gets delivered SIGBUS or
1098  * just gets major/minor fault counters bumped up.
1099  */
1100 
1101 #define VM_FAULT_OOM    0x0001
1102 #define VM_FAULT_SIGBUS 0x0002
1103 #define VM_FAULT_MAJOR  0x0004
1104 #define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
1105 #define VM_FAULT_HWPOISON 0x0010        /* Hit poisoned small page */
1106 #define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
1107 #define VM_FAULT_SIGSEGV 0x0040
1108 
1109 #define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
1110 #define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
1111 #define VM_FAULT_RETRY  0x0400  /* ->fault blocked, must retry */
1112 #define VM_FAULT_FALLBACK 0x0800        /* huge page fault failed, fall back to small */
1113 #define VM_FAULT_DAX_LOCKED 0x1000      /* ->fault has locked DAX entry */
1114 
1115 #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
1116 
1117 #define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
1118                          VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
1119                          VM_FAULT_FALLBACK)
1120 
1121 /* Encode hstate index for a hwpoisoned large page */
1122 #define VM_FAULT_SET_HINDEX(x) ((x) << 12)
1123 #define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
1124 
1125 /*
1126  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
1127  */
1128 extern void pagefault_out_of_memory(void);
1129 
1130 #define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
1131 
1132 /*
1133  * Flags passed to show_mem() and show_free_areas() to suppress output in
1134  * various contexts.
1135  */
1136 #define SHOW_MEM_FILTER_NODES           (0x0001u)       /* disallowed nodes */
1137 
1138 extern void show_free_areas(unsigned int flags);
1139 extern bool skip_free_areas_node(unsigned int flags, int nid);
1140 
1141 int shmem_zero_setup(struct vm_area_struct *);
1142 #ifdef CONFIG_SHMEM
1143 bool shmem_mapping(struct address_space *mapping);
1144 #else
1145 static inline bool shmem_mapping(struct address_space *mapping)
1146 {
1147         return false;
1148 }
1149 #endif
1150 
1151 extern bool can_do_mlock(void);
1152 extern int user_shm_lock(size_t, struct user_struct *);
1153 extern void user_shm_unlock(size_t, struct user_struct *);
1154 
1155 /*
1156  * Parameter block passed down to zap_pte_range in exceptional cases.
1157  */
1158 struct zap_details {
1159         struct address_space *check_mapping;    /* Check page->mapping if set */
1160         pgoff_t first_index;                    /* Lowest page->index to unmap */
1161         pgoff_t last_index;                     /* Highest page->index to unmap */
1162         bool ignore_dirty;                      /* Ignore dirty pages */
1163         bool check_swap_entries;                /* Check also swap entries */
1164 };
1165 
1166 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
1167                 pte_t pte);
1168 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
1169                                 pmd_t pmd);
1170 
1171 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
1172                 unsigned long size);
1173 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
1174                 unsigned long size, struct zap_details *);
1175 void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
1176                 unsigned long start, unsigned long end);
1177 
1178 /**
1179  * mm_walk - callbacks for walk_page_range
1180  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
1181  *             this handler is required to be able to handle
1182  *             pmd_trans_huge() pmds.  They may simply choose to
1183  *             split_huge_page() instead of handling it explicitly.
1184  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
1185  * @pte_hole: if set, called for each hole at all levels
1186  * @hugetlb_entry: if set, called for each hugetlb entry
1187  * @test_walk: caller specific callback function to determine whether
1188  *             we walk over the current vma or not. Returning 0
1189  *             value means "do page table walk over the current vma,"
1190  *             and a negative one means "abort current page table walk
1191  *             right now." 1 means "skip the current vma."
1192  * @mm:        mm_struct representing the target process of page table walk
1193  * @vma:       vma currently walked (NULL if walking outside vmas)
1194  * @private:   private data for callbacks' usage
1195  *
1196  * (see the comment on walk_page_range() for more details)
1197  */
1198 struct mm_walk {
1199         int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
1200                          unsigned long next, struct mm_walk *walk);
1201         int (*pte_entry)(pte_t *pte, unsigned long addr,
1202                          unsigned long next, struct mm_walk *walk);
1203         int (*pte_hole)(unsigned long addr, unsigned long next,
1204                         struct mm_walk *walk);
1205         int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
1206                              unsigned long addr, unsigned long next,
1207                              struct mm_walk *walk);
1208         int (*test_walk)(unsigned long addr, unsigned long next,
1209                         struct mm_walk *walk);
1210         struct mm_struct *mm;
1211         struct vm_area_struct *vma;
1212         void *private;
1213 };
1214 
1215 int walk_page_range(unsigned long addr, unsigned long end,
1216                 struct mm_walk *walk);
1217 int walk_page_vma(struct vm_area_struct *vma, struct mm_walk *walk);
1218 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
1219                 unsigned long end, unsigned long floor, unsigned long ceiling);
1220 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
1221                         struct vm_area_struct *vma);
1222 void unmap_mapping_range(struct address_space *mapping,
1223                 loff_t const holebegin, loff_t const holelen, int even_cows);
1224 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
1225         unsigned long *pfn);
1226 int follow_phys(struct vm_area_struct *vma, unsigned long address,
1227                 unsigned int flags, unsigned long *prot, resource_size_t *phys);
1228 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
1229                         void *buf, int len, int write);
1230 
1231 static inline void unmap_shared_mapping_range(struct address_space *mapping,
1232                 loff_t const holebegin, loff_t const holelen)
1233 {
1234         unmap_mapping_range(mapping, holebegin, holelen, 0);
1235 }
1236 
1237 extern void truncate_pagecache(struct inode *inode, loff_t new);
1238 extern void truncate_setsize(struct inode *inode, loff_t newsize);
1239 void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
1240 void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
1241 int truncate_inode_page(struct address_space *mapping, struct page *page);
1242 int generic_error_remove_page(struct address_space *mapping, struct page *page);
1243 int invalidate_inode_page(struct page *page);
1244 
1245 #ifdef CONFIG_MMU
1246 extern int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
1247                 unsigned int flags);
1248 extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
1249                             unsigned long address, unsigned int fault_flags,
1250                             bool *unlocked);
1251 #else
1252 static inline int handle_mm_fault(struct vm_area_struct *vma,
1253                 unsigned long address, unsigned int flags)
1254 {
1255         /* should never happen if there's no MMU */
1256         BUG();
1257         return VM_FAULT_SIGBUS;
1258 }
1259 static inline int fixup_user_fault(struct task_struct *tsk,
1260                 struct mm_struct *mm, unsigned long address,
1261                 unsigned int fault_flags, bool *unlocked)
1262 {
1263         /* should never happen if there's no MMU */
1264         BUG();
1265         return -EFAULT;
1266 }
1267 #endif
1268 
1269 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len,
1270                 unsigned int gup_flags);
1271 extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1272                 void *buf, int len, unsigned int gup_flags);
1273 
1274 long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
1275                             unsigned long start, unsigned long nr_pages,
1276                             unsigned int gup_flags, struct page **pages,
1277                             struct vm_area_struct **vmas);
1278 long get_user_pages(unsigned long start, unsigned long nr_pages,
1279                             unsigned int gup_flags, struct page **pages,
1280                             struct vm_area_struct **vmas);
1281 long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
1282                     unsigned int gup_flags, struct page **pages, int *locked);
1283 long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
1284                                unsigned long start, unsigned long nr_pages,
1285                                struct page **pages, unsigned int gup_flags);
1286 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
1287                     struct page **pages, unsigned int gup_flags);
1288 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
1289                         struct page **pages);
1290 
1291 /* Container for pinned pfns / pages */
1292 struct frame_vector {
1293         unsigned int nr_allocated;      /* Number of frames we have space for */
1294         unsigned int nr_frames; /* Number of frames stored in ptrs array */
1295         bool got_ref;           /* Did we pin pages by getting page ref? */
1296         bool is_pfns;           /* Does array contain pages or pfns? */
1297         void *ptrs[0];          /* Array of pinned pfns / pages. Use
1298                                  * pfns_vector_pages() or pfns_vector_pfns()
1299                                  * for access */
1300 };
1301 
1302 struct frame_vector *frame_vector_create(unsigned int nr_frames);
1303 void frame_vector_destroy(struct frame_vector *vec);
1304 int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
1305                      unsigned int gup_flags, struct frame_vector *vec);
1306 void put_vaddr_frames(struct frame_vector *vec);
1307 int frame_vector_to_pages(struct frame_vector *vec);
1308 void frame_vector_to_pfns(struct frame_vector *vec);
1309 
1310 static inline unsigned int frame_vector_count(struct frame_vector *vec)
1311 {
1312         return vec->nr_frames;
1313 }
1314 
1315 static inline struct page **frame_vector_pages(struct frame_vector *vec)
1316 {
1317         if (vec->is_pfns) {
1318                 int err = frame_vector_to_pages(vec);
1319 
1320                 if (err)
1321                         return ERR_PTR(err);
1322         }
1323         return (struct page **)(vec->ptrs);
1324 }
1325 
1326 static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
1327 {
1328         if (!vec->is_pfns)
1329                 frame_vector_to_pfns(vec);
1330         return (unsigned long *)(vec->ptrs);
1331 }
1332 
1333 struct kvec;
1334 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
1335                         struct page **pages);
1336 int get_kernel_page(unsigned long start, int write, struct page **pages);
1337 struct page *get_dump_page(unsigned long addr);
1338 
1339 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
1340 extern void do_invalidatepage(struct page *page, unsigned int offset,
1341                               unsigned int length);
1342 
1343 int __set_page_dirty_nobuffers(struct page *page);
1344 int __set_page_dirty_no_writeback(struct page *page);
1345 int redirty_page_for_writepage(struct writeback_control *wbc,
1346                                 struct page *page);
1347 void account_page_dirtied(struct page *page, struct address_space *mapping);
1348 void account_page_cleaned(struct page *page, struct address_space *mapping,
1349                           struct bdi_writeback *wb);
1350 int set_page_dirty(struct page *page);
1351 int set_page_dirty_lock(struct page *page);
1352 void cancel_dirty_page(struct page *page);
1353 int clear_page_dirty_for_io(struct page *page);
1354 
1355 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
1356 
1357 /* Is the vma a continuation of the stack vma above it? */
1358 static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
1359 {
1360         return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
1361 }
1362 
1363 static inline bool vma_is_anonymous(struct vm_area_struct *vma)
1364 {
1365         return !vma->vm_ops;
1366 }
1367 
1368 static inline int stack_guard_page_start(struct vm_area_struct *vma,
1369                                              unsigned long addr)
1370 {
1371         return (vma->vm_flags & VM_GROWSDOWN) &&
1372                 (vma->vm_start == addr) &&
1373                 !vma_growsdown(vma->vm_prev, addr);
1374 }
1375 
1376 /* Is the vma a continuation of the stack vma below it? */
1377 static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
1378 {
1379         return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
1380 }
1381 
1382 static inline int stack_guard_page_end(struct vm_area_struct *vma,
1383                                            unsigned long addr)
1384 {
1385         return (vma->vm_flags & VM_GROWSUP) &&
1386                 (vma->vm_end == addr) &&
1387                 !vma_growsup(vma->vm_next, addr);
1388 }
1389 
1390 int vma_is_stack_for_current(struct vm_area_struct *vma);
1391 
1392 extern unsigned long move_page_tables(struct vm_area_struct *vma,
1393                 unsigned long old_addr, struct vm_area_struct *new_vma,
1394                 unsigned long new_addr, unsigned long len,
1395                 bool need_rmap_locks);
1396 extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
1397                               unsigned long end, pgprot_t newprot,
1398                               int dirty_accountable, int prot_numa);
1399 extern int mprotect_fixup(struct vm_area_struct *vma,
1400                           struct vm_area_struct **pprev, unsigned long start,
1401                           unsigned long end, unsigned long newflags);
1402 
1403 /*
1404  * doesn't attempt to fault and will return short.
1405  */
1406 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
1407                           struct page **pages);
1408 /*
1409  * per-process(per-mm_struct) statistics.
1410  */
1411 static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
1412 {
1413         long val = atomic_long_read(&mm->rss_stat.count[member]);
1414 
1415 #ifdef SPLIT_RSS_COUNTING
1416         /*
1417          * counter is updated in asynchronous manner and may go to minus.
1418          * But it's never be expected number for users.
1419          */
1420         if (val < 0)
1421                 val = 0;
1422 #endif
1423         return (unsigned long)val;
1424 }
1425 
1426 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
1427 {
1428         atomic_long_add(value, &mm->rss_stat.count[member]);
1429 }
1430 
1431 static inline void inc_mm_counter(struct mm_struct *mm, int member)
1432 {
1433         atomic_long_inc(&mm->rss_stat.count[member]);
1434 }
1435 
1436 static inline void dec_mm_counter(struct mm_struct *mm, int member)
1437 {
1438         atomic_long_dec(&mm->rss_stat.count[member]);
1439 }
1440 
1441 /* Optimized variant when page is already known not to be PageAnon */
1442 static inline int mm_counter_file(struct page *page)
1443 {
1444         if (PageSwapBacked(page))
1445                 return MM_SHMEMPAGES;
1446         return MM_FILEPAGES;
1447 }
1448 
1449 static inline int mm_counter(struct page *page)
1450 {
1451         if (PageAnon(page))
1452                 return MM_ANONPAGES;
1453         return mm_counter_file(page);
1454 }
1455 
1456 static inline unsigned long get_mm_rss(struct mm_struct *mm)
1457 {
1458         return get_mm_counter(mm, MM_FILEPAGES) +
1459                 get_mm_counter(mm, MM_ANONPAGES) +
1460                 get_mm_counter(mm, MM_SHMEMPAGES);
1461 }
1462 
1463 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
1464 {
1465         return max(mm->hiwater_rss, get_mm_rss(mm));
1466 }
1467 
1468 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
1469 {
1470         return max(mm->hiwater_vm, mm->total_vm);
1471 }
1472 
1473 static inline void update_hiwater_rss(struct mm_struct *mm)
1474 {
1475         unsigned long _rss = get_mm_rss(mm);
1476 
1477         if ((mm)->hiwater_rss < _rss)
1478                 (mm)->hiwater_rss = _rss;
1479 }
1480 
1481 static inline void update_hiwater_vm(struct mm_struct *mm)
1482 {
1483         if (mm->hiwater_vm < mm->total_vm)
1484                 mm->hiwater_vm = mm->total_vm;
1485 }
1486 
1487 static inline void reset_mm_hiwater_rss(struct mm_struct *mm)
1488 {
1489         mm->hiwater_rss = get_mm_rss(mm);
1490 }
1491 
1492 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
1493                                          struct mm_struct *mm)
1494 {
1495         unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
1496 
1497         if (*maxrss < hiwater_rss)
1498                 *maxrss = hiwater_rss;
1499 }
1500 
1501 #if defined(SPLIT_RSS_COUNTING)
1502 void sync_mm_rss(struct mm_struct *mm);
1503 #else
1504 static inline void sync_mm_rss(struct mm_struct *mm)
1505 {
1506 }
1507 #endif
1508 
1509 #ifndef __HAVE_ARCH_PTE_DEVMAP
1510 static inline int pte_devmap(pte_t pte)
1511 {
1512         return 0;
1513 }
1514 #endif
1515 
1516 int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot);
1517 
1518 extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
1519                                spinlock_t **ptl);
1520 static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
1521                                     spinlock_t **ptl)
1522 {
1523         pte_t *ptep;
1524         __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
1525         return ptep;
1526 }
1527 
1528 #ifdef __PAGETABLE_PUD_FOLDED
1529 static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
1530                                                 unsigned long address)
1531 {
1532         return 0;
1533 }
1534 #else
1535 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
1536 #endif
1537 
1538 #if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
1539 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
1540                                                 unsigned long address)
1541 {
1542         return 0;
1543 }
1544 
1545 static inline void mm_nr_pmds_init(struct mm_struct *mm) {}
1546 
1547 static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
1548 {
1549         return 0;
1550 }
1551 
1552 static inline void mm_inc_nr_pmds(struct mm_struct *mm) {}
1553 static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
1554 
1555 #else
1556 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
1557 
1558 static inline void mm_nr_pmds_init(struct mm_struct *mm)
1559 {
1560         atomic_long_set(&mm->nr_pmds, 0);
1561 }
1562 
1563 static inline unsigned long mm_nr_pmds(struct mm_struct *mm)
1564 {
1565         return atomic_long_read(&mm->nr_pmds);
1566 }
1567 
1568 static inline void mm_inc_nr_pmds(struct mm_struct *mm)
1569 {
1570         atomic_long_inc(&mm->nr_pmds);
1571 }
1572 
1573 static inline void mm_dec_nr_pmds(struct mm_struct *mm)
1574 {
1575         atomic_long_dec(&mm->nr_pmds);
1576 }
1577 #endif
1578 
1579 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
1580 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
1581 
1582 /*
1583  * The following ifdef needed to get the 4level-fixup.h header to work.
1584  * Remove it when 4level-fixup.h has been removed.
1585  */
1586 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
1587 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1588 {
1589         return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
1590                 NULL: pud_offset(pgd, address);
1591 }
1592 
1593 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
1594 {
1595         return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
1596                 NULL: pmd_offset(pud, address);
1597 }
1598 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
1599 
1600 #if USE_SPLIT_PTE_PTLOCKS
1601 #if ALLOC_SPLIT_PTLOCKS
1602 void __init ptlock_cache_init(void);
1603 extern bool ptlock_alloc(struct page *page);
1604 extern void ptlock_free(struct page *page);
1605 
1606 static inline spinlock_t *ptlock_ptr(struct page *page)
1607 {
1608         return page->ptl;
1609 }
1610 #else /* ALLOC_SPLIT_PTLOCKS */
1611 static inline void ptlock_cache_init(void)
1612 {
1613 }
1614 
1615 static inline bool ptlock_alloc(struct page *page)
1616 {
1617         return true;
1618 }
1619 
1620 static inline void ptlock_free(struct page *page)
1621 {
1622 }
1623 
1624 static inline spinlock_t *ptlock_ptr(struct page *page)
1625 {
1626         return &page->ptl;
1627 }
1628 #endif /* ALLOC_SPLIT_PTLOCKS */
1629 
1630 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
1631 {
1632         return ptlock_ptr(pmd_page(*pmd));
1633 }
1634 
1635 static inline bool ptlock_init(struct page *page)
1636 {
1637         /*
1638          * prep_new_page() initialize page->private (and therefore page->ptl)
1639          * with 0. Make sure nobody took it in use in between.
1640          *
1641          * It can happen if arch try to use slab for page table allocation:
1642          * slab code uses page->slab_cache, which share storage with page->ptl.
1643          */
1644         VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
1645         if (!ptlock_alloc(page))
1646                 return false;
1647         spin_lock_init(ptlock_ptr(page));
1648         return true;
1649 }
1650 
1651 /* Reset page->mapping so free_pages_check won't complain. */
1652 static inline void pte_lock_deinit(struct page *page)
1653 {
1654         page->mapping = NULL;
1655         ptlock_free(page);
1656 }
1657 
1658 #else   /* !USE_SPLIT_PTE_PTLOCKS */
1659 /*
1660  * We use mm->page_table_lock to guard all pagetable pages of the mm.
1661  */
1662 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
1663 {
1664         return &mm->page_table_lock;
1665 }
1666 static inline void ptlock_cache_init(void) {}
1667 static inline bool ptlock_init(struct page *page) { return true; }
1668 static inline void pte_lock_deinit(struct page *page) {}
1669 #endif /* USE_SPLIT_PTE_PTLOCKS */
1670 
1671 static inline void pgtable_init(void)
1672 {
1673         ptlock_cache_init();
1674         pgtable_cache_init();
1675 }
1676 
1677 static inline bool pgtable_page_ctor(struct page *page)
1678 {
1679         if (!ptlock_init(page))
1680                 return false;
1681         inc_zone_page_state(page, NR_PAGETABLE);
1682         return true;
1683 }
1684 
1685 static inline void pgtable_page_dtor(struct page *page)
1686 {
1687         pte_lock_deinit(page);
1688         dec_zone_page_state(page, NR_PAGETABLE);
1689 }
1690 
1691 #define pte_offset_map_lock(mm, pmd, address, ptlp)     \
1692 ({                                                      \
1693         spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
1694         pte_t *__pte = pte_offset_map(pmd, address);    \
1695         *(ptlp) = __ptl;                                \
1696         spin_lock(__ptl);                               \
1697         __pte;                                          \
1698 })
1699 
1700 #define pte_unmap_unlock(pte, ptl)      do {            \
1701         spin_unlock(ptl);                               \
1702         pte_unmap(pte);                                 \
1703 } while (0)
1704 
1705 #define pte_alloc(mm, pmd, address)                     \
1706         (unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, pmd, address))
1707 
1708 #define pte_alloc_map(mm, pmd, address)                 \
1709         (pte_alloc(mm, pmd, address) ? NULL : pte_offset_map(pmd, address))
1710 
1711 #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
1712         (pte_alloc(mm, pmd, address) ?                  \
1713                  NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
1714 
1715 #define pte_alloc_kernel(pmd, address)                  \
1716         ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1717                 NULL: pte_offset_kernel(pmd, address))
1718 
1719 #if USE_SPLIT_PMD_PTLOCKS
1720 
1721 static struct page *pmd_to_page(pmd_t *pmd)
1722 {
1723         unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
1724         return virt_to_page((void *)((unsigned long) pmd & mask));
1725 }
1726 
1727 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
1728 {
1729         return ptlock_ptr(pmd_to_page(pmd));
1730 }
1731 
1732 static inline bool pgtable_pmd_page_ctor(struct page *page)
1733 {
1734 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1735         page->pmd_huge_pte = NULL;
1736 #endif
1737         return ptlock_init(page);
1738 }
1739 
1740 static inline void pgtable_pmd_page_dtor(struct page *page)
1741 {
1742 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1743         VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
1744 #endif
1745         ptlock_free(page);
1746 }
1747 
1748 #define pmd_huge_pte(mm, pmd) (pmd_to_page(pmd)->pmd_huge_pte)
1749 
1750 #else
1751 
1752 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
1753 {
1754         return &mm->page_table_lock;
1755 }
1756 
1757 static inline bool pgtable_pmd_page_ctor(struct page *page) { return true; }
1758 static inline void pgtable_pmd_page_dtor(struct page *page) {}
1759 
1760 #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
1761 
1762 #endif
1763 
1764 static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
1765 {
1766         spinlock_t *ptl = pmd_lockptr(mm, pmd);
1767         spin_lock(ptl);
1768         return ptl;
1769 }
1770 
1771 extern void free_area_init(unsigned long * zones_size);
1772 extern void free_area_init_node(int nid, unsigned long * zones_size,
1773                 unsigned long zone_start_pfn, unsigned long *zholes_size);
1774 extern void free_initmem(void);
1775 
1776 /*
1777  * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
1778  * into the buddy system. The freed pages will be poisoned with pattern
1779  * "poison" if it's within range [0, UCHAR_MAX].
1780  * Return pages freed into the buddy system.
1781  */
1782 extern unsigned long free_reserved_area(void *start, void *end,
1783                                         int poison, char *s);
1784 
1785 #ifdef  CONFIG_HIGHMEM
1786 /*
1787  * Free a highmem page into the buddy system, adjusting totalhigh_pages
1788  * and totalram_pages.
1789  */
1790 extern void free_highmem_page(struct page *page);
1791 #endif
1792 
1793 extern void adjust_managed_page_count(struct page *page, long count);
1794 extern void mem_init_print_info(const char *str);
1795 
1796 extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
1797 
1798 /* Free the reserved page into the buddy system, so it gets managed. */
1799 static inline void __free_reserved_page(struct page *page)
1800 {
1801         ClearPageReserved(page);
1802         init_page_count(page);
1803         __free_page(page);
1804 }
1805 
1806 static inline void free_reserved_page(struct page *page)
1807 {
1808         __free_reserved_page(page);
1809         adjust_managed_page_count(page, 1);
1810 }
1811 
1812 static inline void mark_page_reserved(struct page *page)
1813 {
1814         SetPageReserved(page);
1815         adjust_managed_page_count(page, -1);
1816 }
1817 
1818 /*
1819  * Default method to free all the __init memory into the buddy system.
1820  * The freed pages will be poisoned with pattern "poison" if it's within
1821  * range [0, UCHAR_MAX].
1822  * Return pages freed into the buddy system.
1823  */
1824 static inline unsigned long free_initmem_default(int poison)
1825 {
1826         extern char __init_begin[], __init_end[];
1827 
1828         return free_reserved_area(&__init_begin, &__init_end,
1829                                   poison, "unused kernel");
1830 }
1831 
1832 static inline unsigned long get_num_physpages(void)
1833 {
1834         int nid;
1835         unsigned long phys_pages = 0;
1836 
1837         for_each_online_node(nid)
1838                 phys_pages += node_present_pages(nid);
1839 
1840         return phys_pages;
1841 }
1842 
1843 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1844 /*
1845  * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
1846  * zones, allocate the backing mem_map and account for memory holes in a more
1847  * architecture independent manner. This is a substitute for creating the
1848  * zone_sizes[] and zholes_size[] arrays and passing them to
1849  * free_area_init_node()
1850  *
1851  * An architecture is expected to register range of page frames backed by
1852  * physical memory with memblock_add[_node]() before calling
1853  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1854  * usage, an architecture is expected to do something like
1855  *
1856  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1857  *                                                       max_highmem_pfn};
1858  * for_each_valid_physical_page_range()
1859  *      memblock_add_node(base, size, nid)
1860  * free_area_init_nodes(max_zone_pfns);
1861  *
1862  * free_bootmem_with_active_regions() calls free_bootmem_node() for each
1863  * registered physical page range.  Similarly
1864  * sparse_memory_present_with_active_regions() calls memory_present() for
1865  * each range when SPARSEMEM is enabled.
1866  *
1867  * See mm/page_alloc.c for more information on each function exposed by
1868  * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
1869  */
1870 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1871 unsigned long node_map_pfn_alignment(void);
1872 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1873                                                 unsigned long end_pfn);
1874 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1875                                                 unsigned long end_pfn);
1876 extern void get_pfn_range_for_nid(unsigned int nid,
1877                         unsigned long *start_pfn, unsigned long *end_pfn);
1878 extern unsigned long find_min_pfn_with_active_regions(void);
1879 extern void free_bootmem_with_active_regions(int nid,
1880                                                 unsigned long max_low_pfn);
1881 extern void sparse_memory_present_with_active_regions(int nid);
1882 
1883 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
1884 
1885 #if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
1886     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1887 static inline int __early_pfn_to_nid(unsigned long pfn,
1888                                         struct mminit_pfnnid_cache *state)
1889 {
1890         return 0;
1891 }
1892 #else
1893 /* please see mm/page_alloc.c */
1894 extern int __meminit early_pfn_to_nid(unsigned long pfn);
1895 /* there is a per-arch backend function. */
1896 extern int __meminit __early_pfn_to_nid(unsigned long pfn,
1897                                         struct mminit_pfnnid_cache *state);
1898 #endif
1899 
1900 extern void set_dma_reserve(unsigned long new_dma_reserve);
1901 extern void memmap_init_zone(unsigned long, int, unsigned long,
1902                                 unsigned long, enum memmap_context);
1903 extern void setup_per_zone_wmarks(void);
1904 extern int __meminit init_per_zone_wmark_min(void);
1905 extern void mem_init(void);
1906 extern void __init mmap_init(void);
1907 extern void show_mem(unsigned int flags);
1908 extern long si_mem_available(void);
1909 extern void si_meminfo(struct sysinfo * val);
1910 extern void si_meminfo_node(struct sysinfo *val, int nid);
1911 #ifdef __HAVE_ARCH_RESERVED_KERNEL_PAGES
1912 extern unsigned long arch_reserved_kernel_pages(void);
1913 #endif
1914 
1915 extern __printf(2, 3)
1916 void warn_alloc(gfp_t gfp_mask, const char *fmt, ...);
1917 
1918 extern void setup_per_cpu_pageset(void);
1919 
1920 extern void zone_pcp_update(struct zone *zone);
1921 extern void zone_pcp_reset(struct zone *zone);
1922 
1923 /* page_alloc.c */
1924 extern int min_free_kbytes;
1925 extern int watermark_scale_factor;
1926 
1927 /* nommu.c */
1928 extern atomic_long_t mmap_pages_allocated;
1929 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1930 
1931 /* interval_tree.c */
1932 void vma_interval_tree_insert(struct vm_area_struct *node,
1933                               struct rb_root *root);
1934 void vma_interval_tree_insert_after(struct vm_area_struct *node,
1935                                     struct vm_area_struct *prev,
1936                                     struct rb_root *root);
1937 void vma_interval_tree_remove(struct vm_area_struct *node,
1938                               struct rb_root *root);
1939 struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
1940                                 unsigned long start, unsigned long last);
1941 struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
1942                                 unsigned long start, unsigned long last);
1943 
1944 #define vma_interval_tree_foreach(vma, root, start, last)               \
1945         for (vma = vma_interval_tree_iter_first(root, start, last);     \
1946              vma; vma = vma_interval_tree_iter_next(vma, start, last))
1947 
1948 void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
1949                                    struct rb_root *root);
1950 void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
1951                                    struct rb_root *root);
1952 struct anon_vma_chain *anon_vma_interval_tree_iter_first(
1953         struct rb_root *root, unsigned long start, unsigned long last);
1954 struct anon_vma_chain *anon_vma_interval_tree_iter_next(
1955         struct anon_vma_chain *node, unsigned long start, unsigned long last);
1956 #ifdef CONFIG_DEBUG_VM_RB
1957 void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
1958 #endif
1959 
1960 #define anon_vma_interval_tree_foreach(avc, root, start, last)           \
1961         for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
1962              avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
1963 
1964 /* mmap.c */
1965 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1966 extern int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
1967         unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert,
1968         struct vm_area_struct *expand);
1969 static inline int vma_adjust(struct vm_area_struct *vma, unsigned long start,
1970         unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert)
1971 {
1972         return __vma_adjust(vma, start, end, pgoff, insert, NULL);
1973 }
1974 extern struct vm_area_struct *vma_merge(struct mm_struct *,
1975         struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1976         unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1977         struct mempolicy *, struct vm_userfaultfd_ctx);
1978 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1979 extern int split_vma(struct mm_struct *,
1980         struct vm_area_struct *, unsigned long addr, int new_below);
1981 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1982 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1983         struct rb_node **, struct rb_node *);
1984 extern void unlink_file_vma(struct vm_area_struct *);
1985 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1986         unsigned long addr, unsigned long len, pgoff_t pgoff,
1987         bool *need_rmap_locks);
1988 extern void exit_mmap(struct mm_struct *);
1989 
1990 static inline int check_data_rlimit(unsigned long rlim,
1991                                     unsigned long new,
1992                                     unsigned long start,
1993                                     unsigned long end_data,
1994                                     unsigned long start_data)
1995 {
1996         if (rlim < RLIM_INFINITY) {
1997                 if (((new - start) + (end_data - start_data)) > rlim)
1998                         return -ENOSPC;
1999         }
2000 
2001         return 0;
2002 }
2003 
2004 extern int mm_take_all_locks(struct mm_struct *mm);
2005 extern void mm_drop_all_locks(struct mm_struct *mm);
2006 
2007 extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
2008 extern struct file *get_mm_exe_file(struct mm_struct *mm);
2009 extern struct file *get_task_exe_file(struct task_struct *task);
2010 
2011 extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);
2012 extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);
2013 
2014 extern bool vma_is_special_mapping(const struct vm_area_struct *vma,
2015                                    const struct vm_special_mapping *sm);
2016 extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
2017                                    unsigned long addr, unsigned long len,
2018                                    unsigned long flags,
2019                                    const struct vm_special_mapping *spec);
2020 /* This is an obsolete alternative to _install_special_mapping. */
2021 extern int install_special_mapping(struct mm_struct *mm,
2022                                    unsigned long addr, unsigned long len,
2023                                    unsigned long flags, struct page **pages);
2024 
2025 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
2026 
2027 extern unsigned long mmap_region(struct file *file, unsigned long addr,
2028         unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
2029 extern unsigned long do_mmap(struct file *file, unsigned long addr,
2030         unsigned long len, unsigned long prot, unsigned long flags,
2031         vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate);
2032 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
2033 
2034 static inline unsigned long
2035 do_mmap_pgoff(struct file *file, unsigned long addr,
2036         unsigned long len, unsigned long prot, unsigned long flags,
2037         unsigned long pgoff, unsigned long *populate)
2038 {
2039         return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate);
2040 }
2041 
2042 #ifdef CONFIG_MMU
2043 extern int __mm_populate(unsigned long addr, unsigned long len,
2044                          int ignore_errors);
2045 static inline void mm_populate(unsigned long addr, unsigned long len)
2046 {
2047         /* Ignore errors */
2048         (void) __mm_populate(addr, len, 1);
2049 }
2050 #else
2051 static inline void mm_populate(unsigned long addr, unsigned long len) {}
2052 #endif
2053 
2054 /* These take the mm semaphore themselves */
2055 extern int __must_check vm_brk(unsigned long, unsigned long);
2056 extern int vm_munmap(unsigned long, size_t);
2057 extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
2058         unsigned long, unsigned long,
2059         unsigned long, unsigned long);
2060 
2061 struct vm_unmapped_area_info {
2062 #define VM_UNMAPPED_AREA_TOPDOWN 1
2063         unsigned long flags;
2064         unsigned long length;
2065         unsigned long low_limit;
2066         unsigned long high_limit;
2067         unsigned long align_mask;
2068         unsigned long align_offset;
2069 };
2070 
2071 extern unsigned long unmapped_area(struct vm_unmapped_area_info *info);
2072 extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info);
2073 
2074 /*
2075  * Search for an unmapped address range.
2076  *
2077  * We are looking for a range that:
2078  * - does not intersect with any VMA;
2079  * - is contained within the [low_limit, high_limit) interval;
2080  * - is at least the desired size.
2081  * - satisfies (begin_addr & align_mask) == (align_offset & align_mask)
2082  */
2083 static inline unsigned long
2084 vm_unmapped_area(struct vm_unmapped_area_info *info)
2085 {
2086         if (info->flags & VM_UNMAPPED_AREA_TOPDOWN)
2087                 return unmapped_area_topdown(info);
2088         else
2089                 return unmapped_area(info);
2090 }
2091 
2092 /* truncate.c */
2093 extern void truncate_inode_pages(struct address_space *, loff_t);
2094 extern void truncate_inode_pages_range(struct address_space *,
2095                                        loff_t lstart, loff_t lend);
2096 extern void truncate_inode_pages_final(struct address_space *);
2097 
2098 /* generic vm_area_ops exported for stackable file systems */
2099 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
2100 extern void filemap_map_pages(struct fault_env *fe,
2101                 pgoff_t start_pgoff, pgoff_t end_pgoff);
2102 extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2103 
2104 /* mm/page-writeback.c */
2105 int write_one_page(struct page *page, int wait);
2106 void task_dirty_inc(struct task_struct *tsk);
2107 
2108 /* readahead.c */
2109 #define VM_MAX_READAHEAD        128     /* kbytes */
2110 #define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
2111 
2112 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
2113                         pgoff_t offset, unsigned long nr_to_read);
2114 
2115 void page_cache_sync_readahead(struct address_space *mapping,
2116                                struct file_ra_state *ra,
2117                                struct file *filp,
2118                                pgoff_t offset,
2119                                unsigned long size);
2120 
2121 void page_cache_async_readahead(struct address_space *mapping,
2122                                 struct file_ra_state *ra,
2123                                 struct file *filp,
2124                                 struct page *pg,
2125                                 pgoff_t offset,
2126                                 unsigned long size);
2127 
2128 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
2129 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
2130 
2131 /* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
2132 extern int expand_downwards(struct vm_area_struct *vma,
2133                 unsigned long address);
2134 #if VM_GROWSUP
2135 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
2136 #else
2137   #define expand_upwards(vma, address) (0)
2138 #endif
2139 
2140 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
2141 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
2142 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
2143                                              struct vm_area_struct **pprev);
2144 
2145 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
2146    NULL if none.  Assume start_addr < end_addr. */
2147 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
2148 {
2149         struct vm_area_struct * vma = find_vma(mm,start_addr);
2150 
2151         if (vma && end_addr <= vma->vm_start)
2152                 vma = NULL;
2153         return vma;
2154 }
2155 
2156 static inline unsigned long vma_pages(struct vm_area_struct *vma)
2157 {
2158         return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
2159 }
2160 
2161 /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
2162 static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
2163                                 unsigned long vm_start, unsigned long vm_end)
2164 {
2165         struct vm_area_struct *vma = find_vma(mm, vm_start);
2166 
2167         if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
2168                 vma = NULL;
2169 
2170         return vma;
2171 }
2172 
2173 #ifdef CONFIG_MMU
2174 pgprot_t vm_get_page_prot(unsigned long vm_flags);
2175 void vma_set_page_prot(struct vm_area_struct *vma);
2176 #else
2177 static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
2178 {
2179         return __pgprot(0);
2180 }
2181 static inline void vma_set_page_prot(struct vm_area_struct *vma)
2182 {
2183         vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
2184 }
2185 #endif
2186 
2187 #ifdef CONFIG_NUMA_BALANCING
2188 unsigned long change_prot_numa(struct vm_area_struct *vma,
2189                         unsigned long start, unsigned long end);
2190 #endif
2191 
2192 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
2193 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
2194                         unsigned long pfn, unsigned long size, pgprot_t);
2195 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
2196 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
2197                         unsigned long pfn);
2198 int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
2199                         unsigned long pfn, pgprot_t pgprot);
2200 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
2201                         pfn_t pfn);
2202 int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
2203 
2204 
2205 struct page *follow_page_mask(struct vm_area_struct *vma,
2206                               unsigned long address, unsigned int foll_flags,
2207                               unsigned int *page_mask);
2208 
2209 static inline struct page *follow_page(struct vm_area_struct *vma,
2210                 unsigned long address, unsigned int foll_flags)
2211 {
2212         unsigned int unused_page_mask;
2213         return follow_page_mask(vma, address, foll_flags, &unused_page_mask);
2214 }
2215 
2216 #define FOLL_WRITE      0x01    /* check pte is writable */
2217 #define FOLL_TOUCH      0x02    /* mark page accessed */
2218 #define FOLL_GET        0x04    /* do get_page on page */
2219 #define FOLL_DUMP       0x08    /* give error on hole if it would be zero */
2220 #define FOLL_FORCE      0x10    /* get_user_pages read/write w/o permission */
2221 #define FOLL_NOWAIT     0x20    /* if a disk transfer is needed, start the IO
2222                                  * and return without waiting upon it */
2223 #define FOLL_POPULATE   0x40    /* fault in page */
2224 #define FOLL_SPLIT      0x80    /* don't return transhuge pages, split them */
2225 #define FOLL_HWPOISON   0x100   /* check page is hwpoisoned */
2226 #define FOLL_NUMA       0x200   /* force NUMA hinting page fault */
2227 #define FOLL_MIGRATION  0x400   /* wait for page to replace migration entry */
2228 #define FOLL_TRIED      0x800   /* a retry, previous pass started an IO */
2229 #define FOLL_MLOCK      0x1000  /* lock present pages */
2230 #define FOLL_REMOTE     0x2000  /* we are working on non-current tsk/mm */
2231 #define FOLL_COW        0x4000  /* internal GUP flag */
2232 
2233 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
2234                         void *data);
2235 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
2236                                unsigned long size, pte_fn_t fn, void *data);
2237 
2238 
2239 #ifdef CONFIG_PAGE_POISONING
2240 extern bool page_poisoning_enabled(void);
2241 extern void kernel_poison_pages(struct page *page, int numpages, int enable);
2242 extern bool page_is_poisoned(struct page *page);
2243 #else
2244 static inline bool page_poisoning_enabled(void) { return false; }
2245 static inline void kernel_poison_pages(struct page *page, int numpages,
2246                                         int enable) { }
2247 static inline bool page_is_poisoned(struct page *page) { return false; }
2248 #endif
2249 
2250 #ifdef CONFIG_DEBUG_PAGEALLOC
2251 extern bool _debug_pagealloc_enabled;
2252 extern void __kernel_map_pages(struct page *page, int numpages, int enable);
2253 
2254 static inline bool debug_pagealloc_enabled(void)
2255 {
2256         return _debug_pagealloc_enabled;
2257 }
2258 
2259 static inline void
2260 kernel_map_pages(struct page *page, int numpages, int enable)
2261 {
2262         if (!debug_pagealloc_enabled())
2263                 return;
2264 
2265         __kernel_map_pages(page, numpages, enable);
2266 }
2267 #ifdef CONFIG_HIBERNATION
2268 extern bool kernel_page_present(struct page *page);
2269 #endif  /* CONFIG_HIBERNATION */
2270 #else   /* CONFIG_DEBUG_PAGEALLOC */
2271 static inline void
2272 kernel_map_pages(struct page *page, int numpages, int enable) {}
2273 #ifdef CONFIG_HIBERNATION
2274 static inline bool kernel_page_present(struct page *page) { return true; }
2275 #endif  /* CONFIG_HIBERNATION */
2276 static inline bool debug_pagealloc_enabled(void)
2277 {
2278         return false;
2279 }
2280 #endif  /* CONFIG_DEBUG_PAGEALLOC */
2281 
2282 #ifdef __HAVE_ARCH_GATE_AREA
2283 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
2284 extern int in_gate_area_no_mm(unsigned long addr);
2285 extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
2286 #else
2287 static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
2288 {
2289         return NULL;
2290 }
2291 static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
2292 static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
2293 {
2294         return 0;
2295 }
2296 #endif  /* __HAVE_ARCH_GATE_AREA */
2297 
2298 extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
2299 
2300 #ifdef CONFIG_SYSCTL
2301 extern int sysctl_drop_caches;
2302 int drop_caches_sysctl_handler(struct ctl_table *, int,
2303                                         void __user *, size_t *, loff_t *);
2304 #endif
2305 
2306 void drop_slab(void);
2307 void drop_slab_node(int nid);
2308 
2309 #ifndef CONFIG_MMU
2310 #define randomize_va_space 0
2311 #else
2312 extern int randomize_va_space;
2313 #endif
2314 
2315 const char * arch_vma_name(struct vm_area_struct *vma);
2316 void print_vma_addr(char *prefix, unsigned long rip);
2317 
2318 void sparse_mem_maps_populate_node(struct page **map_map,
2319                                    unsigned long pnum_begin,
2320                                    unsigned long pnum_end,
2321                                    unsigned long map_count,
2322                                    int nodeid);
2323 
2324 struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
2325 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
2326 pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
2327 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
2328 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
2329 void *vmemmap_alloc_block(unsigned long size, int node);
2330 struct vmem_altmap;
2331 void *__vmemmap_alloc_block_buf(unsigned long size, int node,
2332                 struct vmem_altmap *altmap);
2333 static inline void *vmemmap_alloc_block_buf(unsigned long size, int node)
2334 {
2335         return __vmemmap_alloc_block_buf(size, node, NULL);
2336 }
2337 
2338 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
2339 int vmemmap_populate_basepages(unsigned long start, unsigned long end,
2340                                int node);
2341 int vmemmap_populate(unsigned long start, unsigned long end, int node);
2342 void vmemmap_populate_print_last(void);
2343 #ifdef CONFIG_MEMORY_HOTPLUG
2344 void vmemmap_free(unsigned long start, unsigned long end);
2345 #endif
2346 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
2347                                   unsigned long size);
2348 
2349 enum mf_flags {
2350         MF_COUNT_INCREASED = 1 << 0,
2351         MF_ACTION_REQUIRED = 1 << 1,
2352         MF_MUST_KILL = 1 << 2,
2353         MF_SOFT_OFFLINE = 1 << 3,
2354 };
2355 extern int memory_failure(unsigned long pfn, int trapno, int flags);
2356 extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
2357 extern int unpoison_memory(unsigned long pfn);
2358 extern int get_hwpoison_page(struct page *page);
2359 #define put_hwpoison_page(page) put_page(page)
2360 extern int sysctl_memory_failure_early_kill;
2361 extern int sysctl_memory_failure_recovery;
2362 extern void shake_page(struct page *p, int access);
2363 extern atomic_long_t num_poisoned_pages;
2364 extern int soft_offline_page(struct page *page, int flags);
2365 
2366 
2367 /*
2368  * Error handlers for various types of pages.
2369  */
2370 enum mf_result {
2371         MF_IGNORED,     /* Error: cannot be handled */
2372         MF_FAILED,      /* Error: handling failed */
2373         MF_DELAYED,     /* Will be handled later */
2374         MF_RECOVERED,   /* Successfully recovered */
2375 };
2376 
2377 enum mf_action_page_type {
2378         MF_MSG_KERNEL,
2379         MF_MSG_KERNEL_HIGH_ORDER,
2380         MF_MSG_SLAB,
2381         MF_MSG_DIFFERENT_COMPOUND,
2382         MF_MSG_POISONED_HUGE,
2383         MF_MSG_HUGE,
2384         MF_MSG_FREE_HUGE,
2385         MF_MSG_UNMAP_FAILED,
2386         MF_MSG_DIRTY_SWAPCACHE,
2387         MF_MSG_CLEAN_SWAPCACHE,
2388         MF_MSG_DIRTY_MLOCKED_LRU,
2389         MF_MSG_CLEAN_MLOCKED_LRU,
2390         MF_MSG_DIRTY_UNEVICTABLE_LRU,
2391         MF_MSG_CLEAN_UNEVICTABLE_LRU,
2392         MF_MSG_DIRTY_LRU,
2393         MF_MSG_CLEAN_LRU,
2394         MF_MSG_TRUNCATED_LRU,
2395         MF_MSG_BUDDY,
2396         MF_MSG_BUDDY_2ND,
2397         MF_MSG_UNKNOWN,
2398 };
2399 
2400 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
2401 extern void clear_huge_page(struct page *page,
2402                             unsigned long addr,
2403                             unsigned int pages_per_huge_page);
2404 extern void copy_user_huge_page(struct page *dst, struct page *src,
2405                                 unsigned long addr, struct vm_area_struct *vma,
2406                                 unsigned int pages_per_huge_page);
2407 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
2408 
2409 extern struct page_ext_operations debug_guardpage_ops;
2410 extern struct page_ext_operations page_poisoning_ops;
2411 
2412 #ifdef CONFIG_DEBUG_PAGEALLOC
2413 extern unsigned int _debug_guardpage_minorder;
2414 extern bool _debug_guardpage_enabled;
2415 
2416 static inline unsigned int debug_guardpage_minorder(void)
2417 {
2418         return _debug_guardpage_minorder;
2419 }
2420 
2421 static inline bool debug_guardpage_enabled(void)
2422 {
2423         return _debug_guardpage_enabled;
2424 }
2425 
2426 static inline bool page_is_guard(struct page *page)
2427 {
2428         struct page_ext *page_ext;
2429 
2430         if (!debug_guardpage_enabled())
2431                 return false;
2432 
2433         page_ext = lookup_page_ext(page);
2434         if (unlikely(!page_ext))
2435                 return false;
2436 
2437         return test_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
2438 }
2439 #else
2440 static inline unsigned int debug_guardpage_minorder(void) { return 0; }
2441 static inline bool debug_guardpage_enabled(void) { return false; }
2442 static inline bool page_is_guard(struct page *page) { return false; }
2443 #endif /* CONFIG_DEBUG_PAGEALLOC */
2444 
2445 #if MAX_NUMNODES > 1
2446 void __init setup_nr_node_ids(void);
2447 #else
2448 static inline void setup_nr_node_ids(void) {}
2449 #endif
2450 
2451 #endif /* __KERNEL__ */
2452 #endif /* _LINUX_MM_H */
2453 

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