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

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