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

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