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TOMOYO Linux Cross Reference
Linux/include/linux/mm.h

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  1 #ifndef _LINUX_MM_H
  2 #define _LINUX_MM_H
  3 
  4 #include <linux/errno.h>
  5 
  6 #ifdef __KERNEL__
  7 
  8 #include <linux/gfp.h>
  9 #include <linux/bug.h>
 10 #include <linux/list.h>
 11 #include <linux/mmzone.h>
 12 #include <linux/rbtree.h>
 13 #include <linux/atomic.h>
 14 #include <linux/debug_locks.h>
 15 #include <linux/mm_types.h>
 16 #include <linux/range.h>
 17 #include <linux/pfn.h>
 18 #include <linux/bit_spinlock.h>
 19 #include <linux/shrinker.h>
 20 
 21 struct mempolicy;
 22 struct anon_vma;
 23 struct anon_vma_chain;
 24 struct file_ra_state;
 25 struct user_struct;
 26 struct writeback_control;
 27 
 28 #ifndef CONFIG_NEED_MULTIPLE_NODES      /* Don't use mapnrs, do it properly */
 29 extern unsigned long max_mapnr;
 30 
 31 static inline void set_max_mapnr(unsigned long limit)
 32 {
 33         max_mapnr = limit;
 34 }
 35 #else
 36 static inline void set_max_mapnr(unsigned long limit) { }
 37 #endif
 38 
 39 extern unsigned long totalram_pages;
 40 extern void * high_memory;
 41 extern int page_cluster;
 42 
 43 #ifdef CONFIG_SYSCTL
 44 extern int sysctl_legacy_va_layout;
 45 #else
 46 #define sysctl_legacy_va_layout 0
 47 #endif
 48 
 49 #include <asm/page.h>
 50 #include <asm/pgtable.h>
 51 #include <asm/processor.h>
 52 
 53 extern unsigned long sysctl_user_reserve_kbytes;
 54 extern unsigned long sysctl_admin_reserve_kbytes;
 55 
 56 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
 57 
 58 /* to align the pointer to the (next) page boundary */
 59 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
 60 
 61 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
 62 #define PAGE_ALIGNED(addr)      IS_ALIGNED((unsigned long)addr, PAGE_SIZE)
 63 
 64 /*
 65  * Linux kernel virtual memory manager primitives.
 66  * The idea being to have a "virtual" mm in the same way
 67  * we have a virtual fs - giving a cleaner interface to the
 68  * mm details, and allowing different kinds of memory mappings
 69  * (from shared memory to executable loading to arbitrary
 70  * mmap() functions).
 71  */
 72 
 73 extern struct kmem_cache *vm_area_cachep;
 74 
 75 #ifndef CONFIG_MMU
 76 extern struct rb_root nommu_region_tree;
 77 extern struct rw_semaphore nommu_region_sem;
 78 
 79 extern unsigned int kobjsize(const void *objp);
 80 #endif
 81 
 82 /*
 83  * vm_flags in vm_area_struct, see mm_types.h.
 84  */
 85 #define VM_NONE         0x00000000
 86 
 87 #define VM_READ         0x00000001      /* currently active flags */
 88 #define VM_WRITE        0x00000002
 89 #define VM_EXEC         0x00000004
 90 #define VM_SHARED       0x00000008
 91 
 92 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
 93 #define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
 94 #define VM_MAYWRITE     0x00000020
 95 #define VM_MAYEXEC      0x00000040
 96 #define VM_MAYSHARE     0x00000080
 97 
 98 #define VM_GROWSDOWN    0x00000100      /* general info on the segment */
 99 #define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
100 #define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
101 
102 #define VM_LOCKED       0x00002000
103 #define VM_IO           0x00004000      /* Memory mapped I/O or similar */
104 
105                                         /* Used by sys_madvise() */
106 #define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
107 #define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
108 
109 #define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
110 #define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
111 #define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
112 #define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
113 #define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
114 #define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
115 #define VM_ARCH_1       0x01000000      /* Architecture-specific flag */
116 #define VM_DONTDUMP     0x04000000      /* Do not include in the core dump */
117 
118 #define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
119 #define VM_HUGEPAGE     0x20000000      /* MADV_HUGEPAGE marked this vma */
120 #define VM_NOHUGEPAGE   0x40000000      /* MADV_NOHUGEPAGE marked this vma */
121 #define VM_MERGEABLE    0x80000000      /* KSM may merge identical pages */
122 
123 #if defined(CONFIG_X86)
124 # define VM_PAT         VM_ARCH_1       /* PAT reserves whole VMA at once (x86) */
125 #elif defined(CONFIG_PPC)
126 # define VM_SAO         VM_ARCH_1       /* Strong Access Ordering (powerpc) */
127 #elif defined(CONFIG_PARISC)
128 # define VM_GROWSUP     VM_ARCH_1
129 #elif defined(CONFIG_METAG)
130 # define VM_GROWSUP     VM_ARCH_1
131 #elif defined(CONFIG_IA64)
132 # define VM_GROWSUP     VM_ARCH_1
133 #elif !defined(CONFIG_MMU)
134 # define VM_MAPPED_COPY VM_ARCH_1       /* T if mapped copy of data (nommu mmap) */
135 #endif
136 
137 #ifndef VM_GROWSUP
138 # define VM_GROWSUP     VM_NONE
139 #endif
140 
141 /* Bits set in the VMA until the stack is in its final location */
142 #define VM_STACK_INCOMPLETE_SETUP       (VM_RAND_READ | VM_SEQ_READ)
143 
144 #ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
145 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
146 #endif
147 
148 #ifdef CONFIG_STACK_GROWSUP
149 #define VM_STACK_FLAGS  (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
150 #else
151 #define VM_STACK_FLAGS  (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
152 #endif
153 
154 /*
155  * Special vmas that are non-mergable, non-mlock()able.
156  * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
157  */
158 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP)
159 
160 /*
161  * mapping from the currently active vm_flags protection bits (the
162  * low four bits) to a page protection mask..
163  */
164 extern pgprot_t protection_map[16];
165 
166 #define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
167 #define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
168 #define FAULT_FLAG_MKWRITE      0x04    /* Fault was mkwrite of existing pte */
169 #define FAULT_FLAG_ALLOW_RETRY  0x08    /* Retry fault if blocking */
170 #define FAULT_FLAG_RETRY_NOWAIT 0x10    /* Don't drop mmap_sem and wait when retrying */
171 #define FAULT_FLAG_KILLABLE     0x20    /* The fault task is in SIGKILL killable region */
172 #define FAULT_FLAG_TRIED        0x40    /* second try */
173 
174 /*
175  * vm_fault is filled by the the pagefault handler and passed to the vma's
176  * ->fault function. The vma's ->fault is responsible for returning a bitmask
177  * of VM_FAULT_xxx flags that give details about how the fault was handled.
178  *
179  * pgoff should be used in favour of virtual_address, if possible. If pgoff
180  * is used, one may implement ->remap_pages to get nonlinear mapping support.
181  */
182 struct vm_fault {
183         unsigned int flags;             /* FAULT_FLAG_xxx flags */
184         pgoff_t pgoff;                  /* Logical page offset based on vma */
185         void __user *virtual_address;   /* Faulting virtual address */
186 
187         struct page *page;              /* ->fault handlers should return a
188                                          * page here, unless VM_FAULT_NOPAGE
189                                          * is set (which is also implied by
190                                          * VM_FAULT_ERROR).
191                                          */
192 };
193 
194 /*
195  * These are the virtual MM functions - opening of an area, closing and
196  * unmapping it (needed to keep files on disk up-to-date etc), pointer
197  * to the functions called when a no-page or a wp-page exception occurs. 
198  */
199 struct vm_operations_struct {
200         void (*open)(struct vm_area_struct * area);
201         void (*close)(struct vm_area_struct * area);
202         int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
203 
204         /* notification that a previously read-only page is about to become
205          * writable, if an error is returned it will cause a SIGBUS */
206         int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
207 
208         /* called by access_process_vm when get_user_pages() fails, typically
209          * for use by special VMAs that can switch between memory and hardware
210          */
211         int (*access)(struct vm_area_struct *vma, unsigned long addr,
212                       void *buf, int len, int write);
213 #ifdef CONFIG_NUMA
214         /*
215          * set_policy() op must add a reference to any non-NULL @new mempolicy
216          * to hold the policy upon return.  Caller should pass NULL @new to
217          * remove a policy and fall back to surrounding context--i.e. do not
218          * install a MPOL_DEFAULT policy, nor the task or system default
219          * mempolicy.
220          */
221         int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
222 
223         /*
224          * get_policy() op must add reference [mpol_get()] to any policy at
225          * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
226          * in mm/mempolicy.c will do this automatically.
227          * get_policy() must NOT add a ref if the policy at (vma,addr) is not
228          * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
229          * If no [shared/vma] mempolicy exists at the addr, get_policy() op
230          * must return NULL--i.e., do not "fallback" to task or system default
231          * policy.
232          */
233         struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
234                                         unsigned long addr);
235         int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
236                 const nodemask_t *to, unsigned long flags);
237 #endif
238         /* called by sys_remap_file_pages() to populate non-linear mapping */
239         int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr,
240                            unsigned long size, pgoff_t pgoff);
241 };
242 
243 struct mmu_gather;
244 struct inode;
245 
246 #define page_private(page)              ((page)->private)
247 #define set_page_private(page, v)       ((page)->private = (v))
248 
249 /* It's valid only if the page is free path or free_list */
250 static inline void set_freepage_migratetype(struct page *page, int migratetype)
251 {
252         page->index = migratetype;
253 }
254 
255 /* It's valid only if the page is free path or free_list */
256 static inline int get_freepage_migratetype(struct page *page)
257 {
258         return page->index;
259 }
260 
261 /*
262  * FIXME: take this include out, include page-flags.h in
263  * files which need it (119 of them)
264  */
265 #include <linux/page-flags.h>
266 #include <linux/huge_mm.h>
267 
268 /*
269  * Methods to modify the page usage count.
270  *
271  * What counts for a page usage:
272  * - cache mapping   (page->mapping)
273  * - private data    (page->private)
274  * - page mapped in a task's page tables, each mapping
275  *   is counted separately
276  *
277  * Also, many kernel routines increase the page count before a critical
278  * routine so they can be sure the page doesn't go away from under them.
279  */
280 
281 /*
282  * Drop a ref, return true if the refcount fell to zero (the page has no users)
283  */
284 static inline int put_page_testzero(struct page *page)
285 {
286         VM_BUG_ON(atomic_read(&page->_count) == 0);
287         return atomic_dec_and_test(&page->_count);
288 }
289 
290 /*
291  * Try to grab a ref unless the page has a refcount of zero, return false if
292  * that is the case.
293  */
294 static inline int get_page_unless_zero(struct page *page)
295 {
296         return atomic_inc_not_zero(&page->_count);
297 }
298 
299 extern int page_is_ram(unsigned long pfn);
300 
301 /* Support for virtually mapped pages */
302 struct page *vmalloc_to_page(const void *addr);
303 unsigned long vmalloc_to_pfn(const void *addr);
304 
305 /*
306  * Determine if an address is within the vmalloc range
307  *
308  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
309  * is no special casing required.
310  */
311 static inline int is_vmalloc_addr(const void *x)
312 {
313 #ifdef CONFIG_MMU
314         unsigned long addr = (unsigned long)x;
315 
316         return addr >= VMALLOC_START && addr < VMALLOC_END;
317 #else
318         return 0;
319 #endif
320 }
321 #ifdef CONFIG_MMU
322 extern int is_vmalloc_or_module_addr(const void *x);
323 #else
324 static inline int is_vmalloc_or_module_addr(const void *x)
325 {
326         return 0;
327 }
328 #endif
329 
330 static inline void compound_lock(struct page *page)
331 {
332 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
333         VM_BUG_ON(PageSlab(page));
334         bit_spin_lock(PG_compound_lock, &page->flags);
335 #endif
336 }
337 
338 static inline void compound_unlock(struct page *page)
339 {
340 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
341         VM_BUG_ON(PageSlab(page));
342         bit_spin_unlock(PG_compound_lock, &page->flags);
343 #endif
344 }
345 
346 static inline unsigned long compound_lock_irqsave(struct page *page)
347 {
348         unsigned long uninitialized_var(flags);
349 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
350         local_irq_save(flags);
351         compound_lock(page);
352 #endif
353         return flags;
354 }
355 
356 static inline void compound_unlock_irqrestore(struct page *page,
357                                               unsigned long flags)
358 {
359 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
360         compound_unlock(page);
361         local_irq_restore(flags);
362 #endif
363 }
364 
365 static inline struct page *compound_head(struct page *page)
366 {
367         if (unlikely(PageTail(page)))
368                 return page->first_page;
369         return page;
370 }
371 
372 /*
373  * The atomic page->_mapcount, starts from -1: so that transitions
374  * both from it and to it can be tracked, using atomic_inc_and_test
375  * and atomic_add_negative(-1).
376  */
377 static inline void page_mapcount_reset(struct page *page)
378 {
379         atomic_set(&(page)->_mapcount, -1);
380 }
381 
382 static inline int page_mapcount(struct page *page)
383 {
384         return atomic_read(&(page)->_mapcount) + 1;
385 }
386 
387 static inline int page_count(struct page *page)
388 {
389         return atomic_read(&compound_head(page)->_count);
390 }
391 
392 static inline void get_huge_page_tail(struct page *page)
393 {
394         /*
395          * __split_huge_page_refcount() cannot run
396          * from under us.
397          */
398         VM_BUG_ON(page_mapcount(page) < 0);
399         VM_BUG_ON(atomic_read(&page->_count) != 0);
400         atomic_inc(&page->_mapcount);
401 }
402 
403 extern bool __get_page_tail(struct page *page);
404 
405 static inline void get_page(struct page *page)
406 {
407         if (unlikely(PageTail(page)))
408                 if (likely(__get_page_tail(page)))
409                         return;
410         /*
411          * Getting a normal page or the head of a compound page
412          * requires to already have an elevated page->_count.
413          */
414         VM_BUG_ON(atomic_read(&page->_count) <= 0);
415         atomic_inc(&page->_count);
416 }
417 
418 static inline struct page *virt_to_head_page(const void *x)
419 {
420         struct page *page = virt_to_page(x);
421         return compound_head(page);
422 }
423 
424 /*
425  * Setup the page count before being freed into the page allocator for
426  * the first time (boot or memory hotplug)
427  */
428 static inline void init_page_count(struct page *page)
429 {
430         atomic_set(&page->_count, 1);
431 }
432 
433 /*
434  * PageBuddy() indicate that the page is free and in the buddy system
435  * (see mm/page_alloc.c).
436  *
437  * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
438  * -2 so that an underflow of the page_mapcount() won't be mistaken
439  * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
440  * efficiently by most CPU architectures.
441  */
442 #define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
443 
444 static inline int PageBuddy(struct page *page)
445 {
446         return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
447 }
448 
449 static inline void __SetPageBuddy(struct page *page)
450 {
451         VM_BUG_ON(atomic_read(&page->_mapcount) != -1);
452         atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
453 }
454 
455 static inline void __ClearPageBuddy(struct page *page)
456 {
457         VM_BUG_ON(!PageBuddy(page));
458         atomic_set(&page->_mapcount, -1);
459 }
460 
461 void put_page(struct page *page);
462 void put_pages_list(struct list_head *pages);
463 
464 void split_page(struct page *page, unsigned int order);
465 int split_free_page(struct page *page);
466 
467 /*
468  * Compound pages have a destructor function.  Provide a
469  * prototype for that function and accessor functions.
470  * These are _only_ valid on the head of a PG_compound page.
471  */
472 typedef void compound_page_dtor(struct page *);
473 
474 static inline void set_compound_page_dtor(struct page *page,
475                                                 compound_page_dtor *dtor)
476 {
477         page[1].lru.next = (void *)dtor;
478 }
479 
480 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
481 {
482         return (compound_page_dtor *)page[1].lru.next;
483 }
484 
485 static inline int compound_order(struct page *page)
486 {
487         if (!PageHead(page))
488                 return 0;
489         return (unsigned long)page[1].lru.prev;
490 }
491 
492 static inline int compound_trans_order(struct page *page)
493 {
494         int order;
495         unsigned long flags;
496 
497         if (!PageHead(page))
498                 return 0;
499 
500         flags = compound_lock_irqsave(page);
501         order = compound_order(page);
502         compound_unlock_irqrestore(page, flags);
503         return order;
504 }
505 
506 static inline void set_compound_order(struct page *page, unsigned long order)
507 {
508         page[1].lru.prev = (void *)order;
509 }
510 
511 #ifdef CONFIG_MMU
512 /*
513  * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
514  * servicing faults for write access.  In the normal case, do always want
515  * pte_mkwrite.  But get_user_pages can cause write faults for mappings
516  * that do not have writing enabled, when used by access_process_vm.
517  */
518 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
519 {
520         if (likely(vma->vm_flags & VM_WRITE))
521                 pte = pte_mkwrite(pte);
522         return pte;
523 }
524 #endif
525 
526 /*
527  * Multiple processes may "see" the same page. E.g. for untouched
528  * mappings of /dev/null, all processes see the same page full of
529  * zeroes, and text pages of executables and shared libraries have
530  * only one copy in memory, at most, normally.
531  *
532  * For the non-reserved pages, page_count(page) denotes a reference count.
533  *   page_count() == 0 means the page is free. page->lru is then used for
534  *   freelist management in the buddy allocator.
535  *   page_count() > 0  means the page has been allocated.
536  *
537  * Pages are allocated by the slab allocator in order to provide memory
538  * to kmalloc and kmem_cache_alloc. In this case, the management of the
539  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
540  * unless a particular usage is carefully commented. (the responsibility of
541  * freeing the kmalloc memory is the caller's, of course).
542  *
543  * A page may be used by anyone else who does a __get_free_page().
544  * In this case, page_count still tracks the references, and should only
545  * be used through the normal accessor functions. The top bits of page->flags
546  * and page->virtual store page management information, but all other fields
547  * are unused and could be used privately, carefully. The management of this
548  * page is the responsibility of the one who allocated it, and those who have
549  * subsequently been given references to it.
550  *
551  * The other pages (we may call them "pagecache pages") are completely
552  * managed by the Linux memory manager: I/O, buffers, swapping etc.
553  * The following discussion applies only to them.
554  *
555  * A pagecache page contains an opaque `private' member, which belongs to the
556  * page's address_space. Usually, this is the address of a circular list of
557  * the page's disk buffers. PG_private must be set to tell the VM to call
558  * into the filesystem to release these pages.
559  *
560  * A page may belong to an inode's memory mapping. In this case, page->mapping
561  * is the pointer to the inode, and page->index is the file offset of the page,
562  * in units of PAGE_CACHE_SIZE.
563  *
564  * If pagecache pages are not associated with an inode, they are said to be
565  * anonymous pages. These may become associated with the swapcache, and in that
566  * case PG_swapcache is set, and page->private is an offset into the swapcache.
567  *
568  * In either case (swapcache or inode backed), the pagecache itself holds one
569  * reference to the page. Setting PG_private should also increment the
570  * refcount. The each user mapping also has a reference to the page.
571  *
572  * The pagecache pages are stored in a per-mapping radix tree, which is
573  * rooted at mapping->page_tree, and indexed by offset.
574  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
575  * lists, we instead now tag pages as dirty/writeback in the radix tree.
576  *
577  * All pagecache pages may be subject to I/O:
578  * - inode pages may need to be read from disk,
579  * - inode pages which have been modified and are MAP_SHARED may need
580  *   to be written back to the inode on disk,
581  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
582  *   modified may need to be swapped out to swap space and (later) to be read
583  *   back into memory.
584  */
585 
586 /*
587  * The zone field is never updated after free_area_init_core()
588  * sets it, so none of the operations on it need to be atomic.
589  */
590 
591 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NID] | ... | FLAGS | */
592 #define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
593 #define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
594 #define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
595 #define LAST_NID_PGOFF          (ZONES_PGOFF - LAST_NID_WIDTH)
596 
597 /*
598  * Define the bit shifts to access each section.  For non-existent
599  * sections we define the shift as 0; that plus a 0 mask ensures
600  * the compiler will optimise away reference to them.
601  */
602 #define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
603 #define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
604 #define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
605 #define LAST_NID_PGSHIFT        (LAST_NID_PGOFF * (LAST_NID_WIDTH != 0))
606 
607 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
608 #ifdef NODE_NOT_IN_PAGE_FLAGS
609 #define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
610 #define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
611                                                 SECTIONS_PGOFF : ZONES_PGOFF)
612 #else
613 #define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
614 #define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
615                                                 NODES_PGOFF : ZONES_PGOFF)
616 #endif
617 
618 #define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
619 
620 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
621 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
622 #endif
623 
624 #define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
625 #define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
626 #define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
627 #define LAST_NID_MASK           ((1UL << LAST_NID_WIDTH) - 1)
628 #define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
629 
630 static inline enum zone_type page_zonenum(const struct page *page)
631 {
632         return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
633 }
634 
635 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
636 #define SECTION_IN_PAGE_FLAGS
637 #endif
638 
639 /*
640  * The identification function is only used by the buddy allocator for
641  * determining if two pages could be buddies. We are not really
642  * identifying a zone since we could be using a the section number
643  * id if we have not node id available in page flags.
644  * We guarantee only that it will return the same value for two
645  * combinable pages in a zone.
646  */
647 static inline int page_zone_id(struct page *page)
648 {
649         return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
650 }
651 
652 static inline int zone_to_nid(struct zone *zone)
653 {
654 #ifdef CONFIG_NUMA
655         return zone->node;
656 #else
657         return 0;
658 #endif
659 }
660 
661 #ifdef NODE_NOT_IN_PAGE_FLAGS
662 extern int page_to_nid(const struct page *page);
663 #else
664 static inline int page_to_nid(const struct page *page)
665 {
666         return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
667 }
668 #endif
669 
670 #ifdef CONFIG_NUMA_BALANCING
671 #ifdef LAST_NID_NOT_IN_PAGE_FLAGS
672 static inline int page_nid_xchg_last(struct page *page, int nid)
673 {
674         return xchg(&page->_last_nid, nid);
675 }
676 
677 static inline int page_nid_last(struct page *page)
678 {
679         return page->_last_nid;
680 }
681 static inline void page_nid_reset_last(struct page *page)
682 {
683         page->_last_nid = -1;
684 }
685 #else
686 static inline int page_nid_last(struct page *page)
687 {
688         return (page->flags >> LAST_NID_PGSHIFT) & LAST_NID_MASK;
689 }
690 
691 extern int page_nid_xchg_last(struct page *page, int nid);
692 
693 static inline void page_nid_reset_last(struct page *page)
694 {
695         int nid = (1 << LAST_NID_SHIFT) - 1;
696 
697         page->flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT);
698         page->flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT;
699 }
700 #endif /* LAST_NID_NOT_IN_PAGE_FLAGS */
701 #else
702 static inline int page_nid_xchg_last(struct page *page, int nid)
703 {
704         return page_to_nid(page);
705 }
706 
707 static inline int page_nid_last(struct page *page)
708 {
709         return page_to_nid(page);
710 }
711 
712 static inline void page_nid_reset_last(struct page *page)
713 {
714 }
715 #endif
716 
717 static inline struct zone *page_zone(const struct page *page)
718 {
719         return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
720 }
721 
722 #ifdef SECTION_IN_PAGE_FLAGS
723 static inline void set_page_section(struct page *page, unsigned long section)
724 {
725         page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
726         page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
727 }
728 
729 static inline unsigned long page_to_section(const struct page *page)
730 {
731         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
732 }
733 #endif
734 
735 static inline void set_page_zone(struct page *page, enum zone_type zone)
736 {
737         page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
738         page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
739 }
740 
741 static inline void set_page_node(struct page *page, unsigned long node)
742 {
743         page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
744         page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
745 }
746 
747 static inline void set_page_links(struct page *page, enum zone_type zone,
748         unsigned long node, unsigned long pfn)
749 {
750         set_page_zone(page, zone);
751         set_page_node(page, node);
752 #ifdef SECTION_IN_PAGE_FLAGS
753         set_page_section(page, pfn_to_section_nr(pfn));
754 #endif
755 }
756 
757 /*
758  * Some inline functions in vmstat.h depend on page_zone()
759  */
760 #include <linux/vmstat.h>
761 
762 static __always_inline void *lowmem_page_address(const struct page *page)
763 {
764         return __va(PFN_PHYS(page_to_pfn(page)));
765 }
766 
767 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
768 #define HASHED_PAGE_VIRTUAL
769 #endif
770 
771 #if defined(WANT_PAGE_VIRTUAL)
772 #define page_address(page) ((page)->virtual)
773 #define set_page_address(page, address)                 \
774         do {                                            \
775                 (page)->virtual = (address);            \
776         } while(0)
777 #define page_address_init()  do { } while(0)
778 #endif
779 
780 #if defined(HASHED_PAGE_VIRTUAL)
781 void *page_address(const struct page *page);
782 void set_page_address(struct page *page, void *virtual);
783 void page_address_init(void);
784 #endif
785 
786 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
787 #define page_address(page) lowmem_page_address(page)
788 #define set_page_address(page, address)  do { } while(0)
789 #define page_address_init()  do { } while(0)
790 #endif
791 
792 /*
793  * On an anonymous page mapped into a user virtual memory area,
794  * page->mapping points to its anon_vma, not to a struct address_space;
795  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
796  *
797  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
798  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
799  * and then page->mapping points, not to an anon_vma, but to a private
800  * structure which KSM associates with that merged page.  See ksm.h.
801  *
802  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
803  *
804  * Please note that, confusingly, "page_mapping" refers to the inode
805  * address_space which maps the page from disk; whereas "page_mapped"
806  * refers to user virtual address space into which the page is mapped.
807  */
808 #define PAGE_MAPPING_ANON       1
809 #define PAGE_MAPPING_KSM        2
810 #define PAGE_MAPPING_FLAGS      (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
811 
812 extern struct address_space *page_mapping(struct page *page);
813 
814 /* Neutral page->mapping pointer to address_space or anon_vma or other */
815 static inline void *page_rmapping(struct page *page)
816 {
817         return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
818 }
819 
820 extern struct address_space *__page_file_mapping(struct page *);
821 
822 static inline
823 struct address_space *page_file_mapping(struct page *page)
824 {
825         if (unlikely(PageSwapCache(page)))
826                 return __page_file_mapping(page);
827 
828         return page->mapping;
829 }
830 
831 static inline int PageAnon(struct page *page)
832 {
833         return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
834 }
835 
836 /*
837  * Return the pagecache index of the passed page.  Regular pagecache pages
838  * use ->index whereas swapcache pages use ->private
839  */
840 static inline pgoff_t page_index(struct page *page)
841 {
842         if (unlikely(PageSwapCache(page)))
843                 return page_private(page);
844         return page->index;
845 }
846 
847 extern pgoff_t __page_file_index(struct page *page);
848 
849 /*
850  * Return the file index of the page. Regular pagecache pages use ->index
851  * whereas swapcache pages use swp_offset(->private)
852  */
853 static inline pgoff_t page_file_index(struct page *page)
854 {
855         if (unlikely(PageSwapCache(page)))
856                 return __page_file_index(page);
857 
858         return page->index;
859 }
860 
861 /*
862  * Return true if this page is mapped into pagetables.
863  */
864 static inline int page_mapped(struct page *page)
865 {
866         return atomic_read(&(page)->_mapcount) >= 0;
867 }
868 
869 /*
870  * Different kinds of faults, as returned by handle_mm_fault().
871  * Used to decide whether a process gets delivered SIGBUS or
872  * just gets major/minor fault counters bumped up.
873  */
874 
875 #define VM_FAULT_MINOR  0 /* For backwards compat. Remove me quickly. */
876 
877 #define VM_FAULT_OOM    0x0001
878 #define VM_FAULT_SIGBUS 0x0002
879 #define VM_FAULT_MAJOR  0x0004
880 #define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
881 #define VM_FAULT_HWPOISON 0x0010        /* Hit poisoned small page */
882 #define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
883 
884 #define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
885 #define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
886 #define VM_FAULT_RETRY  0x0400  /* ->fault blocked, must retry */
887 
888 #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
889 
890 #define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
891                          VM_FAULT_HWPOISON_LARGE)
892 
893 /* Encode hstate index for a hwpoisoned large page */
894 #define VM_FAULT_SET_HINDEX(x) ((x) << 12)
895 #define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
896 
897 /*
898  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
899  */
900 extern void pagefault_out_of_memory(void);
901 
902 #define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
903 
904 /*
905  * Flags passed to show_mem() and show_free_areas() to suppress output in
906  * various contexts.
907  */
908 #define SHOW_MEM_FILTER_NODES           (0x0001u)       /* disallowed nodes */
909 #define SHOW_MEM_FILTER_PAGE_COUNT      (0x0002u)       /* page type count */
910 
911 extern void show_free_areas(unsigned int flags);
912 extern bool skip_free_areas_node(unsigned int flags, int nid);
913 
914 int shmem_zero_setup(struct vm_area_struct *);
915 
916 extern int can_do_mlock(void);
917 extern int user_shm_lock(size_t, struct user_struct *);
918 extern void user_shm_unlock(size_t, struct user_struct *);
919 
920 /*
921  * Parameter block passed down to zap_pte_range in exceptional cases.
922  */
923 struct zap_details {
924         struct vm_area_struct *nonlinear_vma;   /* Check page->index if set */
925         struct address_space *check_mapping;    /* Check page->mapping if set */
926         pgoff_t first_index;                    /* Lowest page->index to unmap */
927         pgoff_t last_index;                     /* Highest page->index to unmap */
928 };
929 
930 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
931                 pte_t pte);
932 
933 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
934                 unsigned long size);
935 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
936                 unsigned long size, struct zap_details *);
937 void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
938                 unsigned long start, unsigned long end);
939 
940 /**
941  * mm_walk - callbacks for walk_page_range
942  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
943  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
944  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
945  *             this handler is required to be able to handle
946  *             pmd_trans_huge() pmds.  They may simply choose to
947  *             split_huge_page() instead of handling it explicitly.
948  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
949  * @pte_hole: if set, called for each hole at all levels
950  * @hugetlb_entry: if set, called for each hugetlb entry
951  *                 *Caution*: The caller must hold mmap_sem() if @hugetlb_entry
952  *                            is used.
953  *
954  * (see walk_page_range for more details)
955  */
956 struct mm_walk {
957         int (*pgd_entry)(pgd_t *pgd, unsigned long addr,
958                          unsigned long next, struct mm_walk *walk);
959         int (*pud_entry)(pud_t *pud, unsigned long addr,
960                          unsigned long next, struct mm_walk *walk);
961         int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
962                          unsigned long next, struct mm_walk *walk);
963         int (*pte_entry)(pte_t *pte, unsigned long addr,
964                          unsigned long next, struct mm_walk *walk);
965         int (*pte_hole)(unsigned long addr, unsigned long next,
966                         struct mm_walk *walk);
967         int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
968                              unsigned long addr, unsigned long next,
969                              struct mm_walk *walk);
970         struct mm_struct *mm;
971         void *private;
972 };
973 
974 int walk_page_range(unsigned long addr, unsigned long end,
975                 struct mm_walk *walk);
976 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
977                 unsigned long end, unsigned long floor, unsigned long ceiling);
978 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
979                         struct vm_area_struct *vma);
980 void unmap_mapping_range(struct address_space *mapping,
981                 loff_t const holebegin, loff_t const holelen, int even_cows);
982 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
983         unsigned long *pfn);
984 int follow_phys(struct vm_area_struct *vma, unsigned long address,
985                 unsigned int flags, unsigned long *prot, resource_size_t *phys);
986 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
987                         void *buf, int len, int write);
988 
989 static inline void unmap_shared_mapping_range(struct address_space *mapping,
990                 loff_t const holebegin, loff_t const holelen)
991 {
992         unmap_mapping_range(mapping, holebegin, holelen, 0);
993 }
994 
995 extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
996 extern void truncate_setsize(struct inode *inode, loff_t newsize);
997 void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
998 int truncate_inode_page(struct address_space *mapping, struct page *page);
999 int generic_error_remove_page(struct address_space *mapping, struct page *page);
1000 int invalidate_inode_page(struct page *page);
1001 
1002 #ifdef CONFIG_MMU
1003 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
1004                         unsigned long address, unsigned int flags);
1005 extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
1006                             unsigned long address, unsigned int fault_flags);
1007 #else
1008 static inline int handle_mm_fault(struct mm_struct *mm,
1009                         struct vm_area_struct *vma, unsigned long address,
1010                         unsigned int flags)
1011 {
1012         /* should never happen if there's no MMU */
1013         BUG();
1014         return VM_FAULT_SIGBUS;
1015 }
1016 static inline int fixup_user_fault(struct task_struct *tsk,
1017                 struct mm_struct *mm, unsigned long address,
1018                 unsigned int fault_flags)
1019 {
1020         /* should never happen if there's no MMU */
1021         BUG();
1022         return -EFAULT;
1023 }
1024 #endif
1025 
1026 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
1027 extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1028                 void *buf, int len, int write);
1029 
1030 long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
1031                       unsigned long start, unsigned long nr_pages,
1032                       unsigned int foll_flags, struct page **pages,
1033                       struct vm_area_struct **vmas, int *nonblocking);
1034 long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
1035                     unsigned long start, unsigned long nr_pages,
1036                     int write, int force, struct page **pages,
1037                     struct vm_area_struct **vmas);
1038 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
1039                         struct page **pages);
1040 struct kvec;
1041 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
1042                         struct page **pages);
1043 int get_kernel_page(unsigned long start, int write, struct page **pages);
1044 struct page *get_dump_page(unsigned long addr);
1045 
1046 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
1047 extern void do_invalidatepage(struct page *page, unsigned int offset,
1048                               unsigned int length);
1049 
1050 int __set_page_dirty_nobuffers(struct page *page);
1051 int __set_page_dirty_no_writeback(struct page *page);
1052 int redirty_page_for_writepage(struct writeback_control *wbc,
1053                                 struct page *page);
1054 void account_page_dirtied(struct page *page, struct address_space *mapping);
1055 void account_page_writeback(struct page *page);
1056 int set_page_dirty(struct page *page);
1057 int set_page_dirty_lock(struct page *page);
1058 int clear_page_dirty_for_io(struct page *page);
1059 
1060 /* Is the vma a continuation of the stack vma above it? */
1061 static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
1062 {
1063         return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
1064 }
1065 
1066 static inline int stack_guard_page_start(struct vm_area_struct *vma,
1067                                              unsigned long addr)
1068 {
1069         return (vma->vm_flags & VM_GROWSDOWN) &&
1070                 (vma->vm_start == addr) &&
1071                 !vma_growsdown(vma->vm_prev, addr);
1072 }
1073 
1074 /* Is the vma a continuation of the stack vma below it? */
1075 static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
1076 {
1077         return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
1078 }
1079 
1080 static inline int stack_guard_page_end(struct vm_area_struct *vma,
1081                                            unsigned long addr)
1082 {
1083         return (vma->vm_flags & VM_GROWSUP) &&
1084                 (vma->vm_end == addr) &&
1085                 !vma_growsup(vma->vm_next, addr);
1086 }
1087 
1088 extern pid_t
1089 vm_is_stack(struct task_struct *task, struct vm_area_struct *vma, int in_group);
1090 
1091 extern unsigned long move_page_tables(struct vm_area_struct *vma,
1092                 unsigned long old_addr, struct vm_area_struct *new_vma,
1093                 unsigned long new_addr, unsigned long len,
1094                 bool need_rmap_locks);
1095 extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
1096                               unsigned long end, pgprot_t newprot,
1097                               int dirty_accountable, int prot_numa);
1098 extern int mprotect_fixup(struct vm_area_struct *vma,
1099                           struct vm_area_struct **pprev, unsigned long start,
1100                           unsigned long end, unsigned long newflags);
1101 
1102 /*
1103  * doesn't attempt to fault and will return short.
1104  */
1105 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
1106                           struct page **pages);
1107 /*
1108  * per-process(per-mm_struct) statistics.
1109  */
1110 static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
1111 {
1112         long val = atomic_long_read(&mm->rss_stat.count[member]);
1113 
1114 #ifdef SPLIT_RSS_COUNTING
1115         /*
1116          * counter is updated in asynchronous manner and may go to minus.
1117          * But it's never be expected number for users.
1118          */
1119         if (val < 0)
1120                 val = 0;
1121 #endif
1122         return (unsigned long)val;
1123 }
1124 
1125 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
1126 {
1127         atomic_long_add(value, &mm->rss_stat.count[member]);
1128 }
1129 
1130 static inline void inc_mm_counter(struct mm_struct *mm, int member)
1131 {
1132         atomic_long_inc(&mm->rss_stat.count[member]);
1133 }
1134 
1135 static inline void dec_mm_counter(struct mm_struct *mm, int member)
1136 {
1137         atomic_long_dec(&mm->rss_stat.count[member]);
1138 }
1139 
1140 static inline unsigned long get_mm_rss(struct mm_struct *mm)
1141 {
1142         return get_mm_counter(mm, MM_FILEPAGES) +
1143                 get_mm_counter(mm, MM_ANONPAGES);
1144 }
1145 
1146 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
1147 {
1148         return max(mm->hiwater_rss, get_mm_rss(mm));
1149 }
1150 
1151 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
1152 {
1153         return max(mm->hiwater_vm, mm->total_vm);
1154 }
1155 
1156 static inline void update_hiwater_rss(struct mm_struct *mm)
1157 {
1158         unsigned long _rss = get_mm_rss(mm);
1159 
1160         if ((mm)->hiwater_rss < _rss)
1161                 (mm)->hiwater_rss = _rss;
1162 }
1163 
1164 static inline void update_hiwater_vm(struct mm_struct *mm)
1165 {
1166         if (mm->hiwater_vm < mm->total_vm)
1167                 mm->hiwater_vm = mm->total_vm;
1168 }
1169 
1170 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
1171                                          struct mm_struct *mm)
1172 {
1173         unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
1174 
1175         if (*maxrss < hiwater_rss)
1176                 *maxrss = hiwater_rss;
1177 }
1178 
1179 #if defined(SPLIT_RSS_COUNTING)
1180 void sync_mm_rss(struct mm_struct *mm);
1181 #else
1182 static inline void sync_mm_rss(struct mm_struct *mm)
1183 {
1184 }
1185 #endif
1186 
1187 int vma_wants_writenotify(struct vm_area_struct *vma);
1188 
1189 extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
1190                                spinlock_t **ptl);
1191 static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
1192                                     spinlock_t **ptl)
1193 {
1194         pte_t *ptep;
1195         __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
1196         return ptep;
1197 }
1198 
1199 #ifdef __PAGETABLE_PUD_FOLDED
1200 static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
1201                                                 unsigned long address)
1202 {
1203         return 0;
1204 }
1205 #else
1206 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
1207 #endif
1208 
1209 #ifdef __PAGETABLE_PMD_FOLDED
1210 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
1211                                                 unsigned long address)
1212 {
1213         return 0;
1214 }
1215 #else
1216 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
1217 #endif
1218 
1219 int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
1220                 pmd_t *pmd, unsigned long address);
1221 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
1222 
1223 /*
1224  * The following ifdef needed to get the 4level-fixup.h header to work.
1225  * Remove it when 4level-fixup.h has been removed.
1226  */
1227 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
1228 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1229 {
1230         return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
1231                 NULL: pud_offset(pgd, address);
1232 }
1233 
1234 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
1235 {
1236         return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
1237                 NULL: pmd_offset(pud, address);
1238 }
1239 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
1240 
1241 #if USE_SPLIT_PTLOCKS
1242 /*
1243  * We tuck a spinlock to guard each pagetable page into its struct page,
1244  * at page->private, with BUILD_BUG_ON to make sure that this will not
1245  * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
1246  * When freeing, reset page->mapping so free_pages_check won't complain.
1247  */
1248 #define __pte_lockptr(page)     &((page)->ptl)
1249 #define pte_lock_init(_page)    do {                                    \
1250         spin_lock_init(__pte_lockptr(_page));                           \
1251 } while (0)
1252 #define pte_lock_deinit(page)   ((page)->mapping = NULL)
1253 #define pte_lockptr(mm, pmd)    ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
1254 #else   /* !USE_SPLIT_PTLOCKS */
1255 /*
1256  * We use mm->page_table_lock to guard all pagetable pages of the mm.
1257  */
1258 #define pte_lock_init(page)     do {} while (0)
1259 #define pte_lock_deinit(page)   do {} while (0)
1260 #define pte_lockptr(mm, pmd)    ({(void)(pmd); &(mm)->page_table_lock;})
1261 #endif /* USE_SPLIT_PTLOCKS */
1262 
1263 static inline void pgtable_page_ctor(struct page *page)
1264 {
1265         pte_lock_init(page);
1266         inc_zone_page_state(page, NR_PAGETABLE);
1267 }
1268 
1269 static inline void pgtable_page_dtor(struct page *page)
1270 {
1271         pte_lock_deinit(page);
1272         dec_zone_page_state(page, NR_PAGETABLE);
1273 }
1274 
1275 #define pte_offset_map_lock(mm, pmd, address, ptlp)     \
1276 ({                                                      \
1277         spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
1278         pte_t *__pte = pte_offset_map(pmd, address);    \
1279         *(ptlp) = __ptl;                                \
1280         spin_lock(__ptl);                               \
1281         __pte;                                          \
1282 })
1283 
1284 #define pte_unmap_unlock(pte, ptl)      do {            \
1285         spin_unlock(ptl);                               \
1286         pte_unmap(pte);                                 \
1287 } while (0)
1288 
1289 #define pte_alloc_map(mm, vma, pmd, address)                            \
1290         ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma,    \
1291                                                         pmd, address))? \
1292          NULL: pte_offset_map(pmd, address))
1293 
1294 #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
1295         ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL,   \
1296                                                         pmd, address))? \
1297                 NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1298 
1299 #define pte_alloc_kernel(pmd, address)                  \
1300         ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1301                 NULL: pte_offset_kernel(pmd, address))
1302 
1303 extern void free_area_init(unsigned long * zones_size);
1304 extern void free_area_init_node(int nid, unsigned long * zones_size,
1305                 unsigned long zone_start_pfn, unsigned long *zholes_size);
1306 extern void free_initmem(void);
1307 
1308 /*
1309  * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
1310  * into the buddy system. The freed pages will be poisoned with pattern
1311  * "poison" if it's within range [0, UCHAR_MAX].
1312  * Return pages freed into the buddy system.
1313  */
1314 extern unsigned long free_reserved_area(void *start, void *end,
1315                                         int poison, char *s);
1316 
1317 #ifdef  CONFIG_HIGHMEM
1318 /*
1319  * Free a highmem page into the buddy system, adjusting totalhigh_pages
1320  * and totalram_pages.
1321  */
1322 extern void free_highmem_page(struct page *page);
1323 #endif
1324 
1325 extern void adjust_managed_page_count(struct page *page, long count);
1326 extern void mem_init_print_info(const char *str);
1327 
1328 /* Free the reserved page into the buddy system, so it gets managed. */
1329 static inline void __free_reserved_page(struct page *page)
1330 {
1331         ClearPageReserved(page);
1332         init_page_count(page);
1333         __free_page(page);
1334 }
1335 
1336 static inline void free_reserved_page(struct page *page)
1337 {
1338         __free_reserved_page(page);
1339         adjust_managed_page_count(page, 1);
1340 }
1341 
1342 static inline void mark_page_reserved(struct page *page)
1343 {
1344         SetPageReserved(page);
1345         adjust_managed_page_count(page, -1);
1346 }
1347 
1348 /*
1349  * Default method to free all the __init memory into the buddy system.
1350  * The freed pages will be poisoned with pattern "poison" if it's within
1351  * range [0, UCHAR_MAX].
1352  * Return pages freed into the buddy system.
1353  */
1354 static inline unsigned long free_initmem_default(int poison)
1355 {
1356         extern char __init_begin[], __init_end[];
1357 
1358         return free_reserved_area(&__init_begin, &__init_end,
1359                                   poison, "unused kernel");
1360 }
1361 
1362 static inline unsigned long get_num_physpages(void)
1363 {
1364         int nid;
1365         unsigned long phys_pages = 0;
1366 
1367         for_each_online_node(nid)
1368                 phys_pages += node_present_pages(nid);
1369 
1370         return phys_pages;
1371 }
1372 
1373 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1374 /*
1375  * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
1376  * zones, allocate the backing mem_map and account for memory holes in a more
1377  * architecture independent manner. This is a substitute for creating the
1378  * zone_sizes[] and zholes_size[] arrays and passing them to
1379  * free_area_init_node()
1380  *
1381  * An architecture is expected to register range of page frames backed by
1382  * physical memory with memblock_add[_node]() before calling
1383  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1384  * usage, an architecture is expected to do something like
1385  *
1386  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1387  *                                                       max_highmem_pfn};
1388  * for_each_valid_physical_page_range()
1389  *      memblock_add_node(base, size, nid)
1390  * free_area_init_nodes(max_zone_pfns);
1391  *
1392  * free_bootmem_with_active_regions() calls free_bootmem_node() for each
1393  * registered physical page range.  Similarly
1394  * sparse_memory_present_with_active_regions() calls memory_present() for
1395  * each range when SPARSEMEM is enabled.
1396  *
1397  * See mm/page_alloc.c for more information on each function exposed by
1398  * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
1399  */
1400 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1401 unsigned long node_map_pfn_alignment(void);
1402 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1403                                                 unsigned long end_pfn);
1404 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1405                                                 unsigned long end_pfn);
1406 extern void get_pfn_range_for_nid(unsigned int nid,
1407                         unsigned long *start_pfn, unsigned long *end_pfn);
1408 extern unsigned long find_min_pfn_with_active_regions(void);
1409 extern void free_bootmem_with_active_regions(int nid,
1410                                                 unsigned long max_low_pfn);
1411 extern void sparse_memory_present_with_active_regions(int nid);
1412 
1413 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
1414 
1415 #if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
1416     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1417 static inline int __early_pfn_to_nid(unsigned long pfn)
1418 {
1419         return 0;
1420 }
1421 #else
1422 /* please see mm/page_alloc.c */
1423 extern int __meminit early_pfn_to_nid(unsigned long pfn);
1424 #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1425 /* there is a per-arch backend function. */
1426 extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1427 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1428 #endif
1429 
1430 extern void set_dma_reserve(unsigned long new_dma_reserve);
1431 extern void memmap_init_zone(unsigned long, int, unsigned long,
1432                                 unsigned long, enum memmap_context);
1433 extern void setup_per_zone_wmarks(void);
1434 extern int __meminit init_per_zone_wmark_min(void);
1435 extern void mem_init(void);
1436 extern void __init mmap_init(void);
1437 extern void show_mem(unsigned int flags);
1438 extern void si_meminfo(struct sysinfo * val);
1439 extern void si_meminfo_node(struct sysinfo *val, int nid);
1440 
1441 extern __printf(3, 4)
1442 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...);
1443 
1444 extern void setup_per_cpu_pageset(void);
1445 
1446 extern void zone_pcp_update(struct zone *zone);
1447 extern void zone_pcp_reset(struct zone *zone);
1448 
1449 /* page_alloc.c */
1450 extern int min_free_kbytes;
1451 
1452 /* nommu.c */
1453 extern atomic_long_t mmap_pages_allocated;
1454 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1455 
1456 /* interval_tree.c */
1457 void vma_interval_tree_insert(struct vm_area_struct *node,
1458                               struct rb_root *root);
1459 void vma_interval_tree_insert_after(struct vm_area_struct *node,
1460                                     struct vm_area_struct *prev,
1461                                     struct rb_root *root);
1462 void vma_interval_tree_remove(struct vm_area_struct *node,
1463                               struct rb_root *root);
1464 struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
1465                                 unsigned long start, unsigned long last);
1466 struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
1467                                 unsigned long start, unsigned long last);
1468 
1469 #define vma_interval_tree_foreach(vma, root, start, last)               \
1470         for (vma = vma_interval_tree_iter_first(root, start, last);     \
1471              vma; vma = vma_interval_tree_iter_next(vma, start, last))
1472 
1473 static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1474                                         struct list_head *list)
1475 {
1476         list_add_tail(&vma->shared.nonlinear, list);
1477 }
1478 
1479 void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
1480                                    struct rb_root *root);
1481 void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
1482                                    struct rb_root *root);
1483 struct anon_vma_chain *anon_vma_interval_tree_iter_first(
1484         struct rb_root *root, unsigned long start, unsigned long last);
1485 struct anon_vma_chain *anon_vma_interval_tree_iter_next(
1486         struct anon_vma_chain *node, unsigned long start, unsigned long last);
1487 #ifdef CONFIG_DEBUG_VM_RB
1488 void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
1489 #endif
1490 
1491 #define anon_vma_interval_tree_foreach(avc, root, start, last)           \
1492         for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
1493              avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
1494 
1495 /* mmap.c */
1496 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1497 extern int vma_adjust(struct vm_area_struct *vma, unsigned long start,
1498         unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1499 extern struct vm_area_struct *vma_merge(struct mm_struct *,
1500         struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1501         unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1502         struct mempolicy *);
1503 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1504 extern int split_vma(struct mm_struct *,
1505         struct vm_area_struct *, unsigned long addr, int new_below);
1506 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1507 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1508         struct rb_node **, struct rb_node *);
1509 extern void unlink_file_vma(struct vm_area_struct *);
1510 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1511         unsigned long addr, unsigned long len, pgoff_t pgoff,
1512         bool *need_rmap_locks);
1513 extern void exit_mmap(struct mm_struct *);
1514 
1515 extern int mm_take_all_locks(struct mm_struct *mm);
1516 extern void mm_drop_all_locks(struct mm_struct *mm);
1517 
1518 extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
1519 extern struct file *get_mm_exe_file(struct mm_struct *mm);
1520 
1521 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1522 extern int install_special_mapping(struct mm_struct *mm,
1523                                    unsigned long addr, unsigned long len,
1524                                    unsigned long flags, struct page **pages);
1525 
1526 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1527 
1528 extern unsigned long mmap_region(struct file *file, unsigned long addr,
1529         unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
1530 extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1531         unsigned long len, unsigned long prot, unsigned long flags,
1532         unsigned long pgoff, unsigned long *populate);
1533 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1534 
1535 #ifdef CONFIG_MMU
1536 extern int __mm_populate(unsigned long addr, unsigned long len,
1537                          int ignore_errors);
1538 static inline void mm_populate(unsigned long addr, unsigned long len)
1539 {
1540         /* Ignore errors */
1541         (void) __mm_populate(addr, len, 1);
1542 }
1543 #else
1544 static inline void mm_populate(unsigned long addr, unsigned long len) {}
1545 #endif
1546 
1547 /* These take the mm semaphore themselves */
1548 extern unsigned long vm_brk(unsigned long, unsigned long);
1549 extern int vm_munmap(unsigned long, size_t);
1550 extern unsigned long vm_mmap(struct file *, unsigned long,
1551         unsigned long, unsigned long,
1552         unsigned long, unsigned long);
1553 
1554 struct vm_unmapped_area_info {
1555 #define VM_UNMAPPED_AREA_TOPDOWN 1
1556         unsigned long flags;
1557         unsigned long length;
1558         unsigned long low_limit;
1559         unsigned long high_limit;
1560         unsigned long align_mask;
1561         unsigned long align_offset;
1562 };
1563 
1564 extern unsigned long unmapped_area(struct vm_unmapped_area_info *info);
1565 extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info);
1566 
1567 /*
1568  * Search for an unmapped address range.
1569  *
1570  * We are looking for a range that:
1571  * - does not intersect with any VMA;
1572  * - is contained within the [low_limit, high_limit) interval;
1573  * - is at least the desired size.
1574  * - satisfies (begin_addr & align_mask) == (align_offset & align_mask)
1575  */
1576 static inline unsigned long
1577 vm_unmapped_area(struct vm_unmapped_area_info *info)
1578 {
1579         if (!(info->flags & VM_UNMAPPED_AREA_TOPDOWN))
1580                 return unmapped_area(info);
1581         else
1582                 return unmapped_area_topdown(info);
1583 }
1584 
1585 /* truncate.c */
1586 extern void truncate_inode_pages(struct address_space *, loff_t);
1587 extern void truncate_inode_pages_range(struct address_space *,
1588                                        loff_t lstart, loff_t lend);
1589 
1590 /* generic vm_area_ops exported for stackable file systems */
1591 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1592 extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1593 
1594 /* mm/page-writeback.c */
1595 int write_one_page(struct page *page, int wait);
1596 void task_dirty_inc(struct task_struct *tsk);
1597 
1598 /* readahead.c */
1599 #define VM_MAX_READAHEAD        128     /* kbytes */
1600 #define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
1601 
1602 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1603                         pgoff_t offset, unsigned long nr_to_read);
1604 
1605 void page_cache_sync_readahead(struct address_space *mapping,
1606                                struct file_ra_state *ra,
1607                                struct file *filp,
1608                                pgoff_t offset,
1609                                unsigned long size);
1610 
1611 void page_cache_async_readahead(struct address_space *mapping,
1612                                 struct file_ra_state *ra,
1613                                 struct file *filp,
1614                                 struct page *pg,
1615                                 pgoff_t offset,
1616                                 unsigned long size);
1617 
1618 unsigned long max_sane_readahead(unsigned long nr);
1619 unsigned long ra_submit(struct file_ra_state *ra,
1620                         struct address_space *mapping,
1621                         struct file *filp);
1622 
1623 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
1624 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1625 
1626 /* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
1627 extern int expand_downwards(struct vm_area_struct *vma,
1628                 unsigned long address);
1629 #if VM_GROWSUP
1630 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1631 #else
1632   #define expand_upwards(vma, address) do { } while (0)
1633 #endif
1634 
1635 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1636 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1637 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1638                                              struct vm_area_struct **pprev);
1639 
1640 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1641    NULL if none.  Assume start_addr < end_addr. */
1642 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1643 {
1644         struct vm_area_struct * vma = find_vma(mm,start_addr);
1645 
1646         if (vma && end_addr <= vma->vm_start)
1647                 vma = NULL;
1648         return vma;
1649 }
1650 
1651 static inline unsigned long vma_pages(struct vm_area_struct *vma)
1652 {
1653         return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1654 }
1655 
1656 /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
1657 static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
1658                                 unsigned long vm_start, unsigned long vm_end)
1659 {
1660         struct vm_area_struct *vma = find_vma(mm, vm_start);
1661 
1662         if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
1663                 vma = NULL;
1664 
1665         return vma;
1666 }
1667 
1668 #ifdef CONFIG_MMU
1669 pgprot_t vm_get_page_prot(unsigned long vm_flags);
1670 #else
1671 static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
1672 {
1673         return __pgprot(0);
1674 }
1675 #endif
1676 
1677 #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
1678 unsigned long change_prot_numa(struct vm_area_struct *vma,
1679                         unsigned long start, unsigned long end);
1680 #endif
1681 
1682 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1683 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1684                         unsigned long pfn, unsigned long size, pgprot_t);
1685 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1686 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1687                         unsigned long pfn);
1688 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1689                         unsigned long pfn);
1690 int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
1691 
1692 
1693 struct page *follow_page_mask(struct vm_area_struct *vma,
1694                               unsigned long address, unsigned int foll_flags,
1695                               unsigned int *page_mask);
1696 
1697 static inline struct page *follow_page(struct vm_area_struct *vma,
1698                 unsigned long address, unsigned int foll_flags)
1699 {
1700         unsigned int unused_page_mask;
1701         return follow_page_mask(vma, address, foll_flags, &unused_page_mask);
1702 }
1703 
1704 #define FOLL_WRITE      0x01    /* check pte is writable */
1705 #define FOLL_TOUCH      0x02    /* mark page accessed */
1706 #define FOLL_GET        0x04    /* do get_page on page */
1707 #define FOLL_DUMP       0x08    /* give error on hole if it would be zero */
1708 #define FOLL_FORCE      0x10    /* get_user_pages read/write w/o permission */
1709 #define FOLL_NOWAIT     0x20    /* if a disk transfer is needed, start the IO
1710                                  * and return without waiting upon it */
1711 #define FOLL_MLOCK      0x40    /* mark page as mlocked */
1712 #define FOLL_SPLIT      0x80    /* don't return transhuge pages, split them */
1713 #define FOLL_HWPOISON   0x100   /* check page is hwpoisoned */
1714 #define FOLL_NUMA       0x200   /* force NUMA hinting page fault */
1715 #define FOLL_MIGRATION  0x400   /* wait for page to replace migration entry */
1716 
1717 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1718                         void *data);
1719 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1720                                unsigned long size, pte_fn_t fn, void *data);
1721 
1722 #ifdef CONFIG_PROC_FS
1723 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1724 #else
1725 static inline void vm_stat_account(struct mm_struct *mm,
1726                         unsigned long flags, struct file *file, long pages)
1727 {
1728         mm->total_vm += pages;
1729 }
1730 #endif /* CONFIG_PROC_FS */
1731 
1732 #ifdef CONFIG_DEBUG_PAGEALLOC
1733 extern void kernel_map_pages(struct page *page, int numpages, int enable);
1734 #ifdef CONFIG_HIBERNATION
1735 extern bool kernel_page_present(struct page *page);
1736 #endif /* CONFIG_HIBERNATION */
1737 #else
1738 static inline void
1739 kernel_map_pages(struct page *page, int numpages, int enable) {}
1740 #ifdef CONFIG_HIBERNATION
1741 static inline bool kernel_page_present(struct page *page) { return true; }
1742 #endif /* CONFIG_HIBERNATION */
1743 #endif
1744 
1745 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
1746 #ifdef  __HAVE_ARCH_GATE_AREA
1747 int in_gate_area_no_mm(unsigned long addr);
1748 int in_gate_area(struct mm_struct *mm, unsigned long addr);
1749 #else
1750 int in_gate_area_no_mm(unsigned long addr);
1751 #define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);})
1752 #endif  /* __HAVE_ARCH_GATE_AREA */
1753 
1754 #ifdef CONFIG_SYSCTL
1755 extern int sysctl_drop_caches;
1756 int drop_caches_sysctl_handler(struct ctl_table *, int,
1757                                         void __user *, size_t *, loff_t *);
1758 #endif
1759 
1760 unsigned long shrink_slab(struct shrink_control *shrink,
1761                           unsigned long nr_pages_scanned,
1762                           unsigned long lru_pages);
1763 
1764 #ifndef CONFIG_MMU
1765 #define randomize_va_space 0
1766 #else
1767 extern int randomize_va_space;
1768 #endif
1769 
1770 const char * arch_vma_name(struct vm_area_struct *vma);
1771 void print_vma_addr(char *prefix, unsigned long rip);
1772 
1773 void sparse_mem_maps_populate_node(struct page **map_map,
1774                                    unsigned long pnum_begin,
1775                                    unsigned long pnum_end,
1776                                    unsigned long map_count,
1777                                    int nodeid);
1778 
1779 struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1780 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1781 pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1782 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1783 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1784 void *vmemmap_alloc_block(unsigned long size, int node);
1785 void *vmemmap_alloc_block_buf(unsigned long size, int node);
1786 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1787 int vmemmap_populate_basepages(unsigned long start, unsigned long end,
1788                                int node);
1789 int vmemmap_populate(unsigned long start, unsigned long end, int node);
1790 void vmemmap_populate_print_last(void);
1791 #ifdef CONFIG_MEMORY_HOTPLUG
1792 void vmemmap_free(unsigned long start, unsigned long end);
1793 #endif
1794 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
1795                                   unsigned long size);
1796 
1797 enum mf_flags {
1798         MF_COUNT_INCREASED = 1 << 0,
1799         MF_ACTION_REQUIRED = 1 << 1,
1800         MF_MUST_KILL = 1 << 2,
1801 };
1802 extern int memory_failure(unsigned long pfn, int trapno, int flags);
1803 extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
1804 extern int unpoison_memory(unsigned long pfn);
1805 extern int sysctl_memory_failure_early_kill;
1806 extern int sysctl_memory_failure_recovery;
1807 extern void shake_page(struct page *p, int access);
1808 extern atomic_long_t num_poisoned_pages;
1809 extern int soft_offline_page(struct page *page, int flags);
1810 
1811 extern void dump_page(struct page *page);
1812 
1813 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
1814 extern void clear_huge_page(struct page *page,
1815                             unsigned long addr,
1816                             unsigned int pages_per_huge_page);
1817 extern void copy_user_huge_page(struct page *dst, struct page *src,
1818                                 unsigned long addr, struct vm_area_struct *vma,
1819                                 unsigned int pages_per_huge_page);
1820 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
1821 
1822 #ifdef CONFIG_DEBUG_PAGEALLOC
1823 extern unsigned int _debug_guardpage_minorder;
1824 
1825 static inline unsigned int debug_guardpage_minorder(void)
1826 {
1827         return _debug_guardpage_minorder;
1828 }
1829 
1830 static inline bool page_is_guard(struct page *page)
1831 {
1832         return test_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
1833 }
1834 #else
1835 static inline unsigned int debug_guardpage_minorder(void) { return 0; }
1836 static inline bool page_is_guard(struct page *page) { return false; }
1837 #endif /* CONFIG_DEBUG_PAGEALLOC */
1838 
1839 #if MAX_NUMNODES > 1
1840 void __init setup_nr_node_ids(void);
1841 #else
1842 static inline void setup_nr_node_ids(void) {}
1843 #endif
1844 
1845 #endif /* __KERNEL__ */
1846 #endif /* _LINUX_MM_H */
1847 

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