xref: /linux-6.15/include/linux/mm.h (revision 8b1935e6)
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/list.h>
10 #include <linux/mmzone.h>
11 #include <linux/rbtree.h>
12 #include <linux/prio_tree.h>
13 #include <linux/debug_locks.h>
14 #include <linux/mm_types.h>
15 
16 struct mempolicy;
17 struct anon_vma;
18 struct file_ra_state;
19 struct user_struct;
20 struct writeback_control;
21 struct rlimit;
22 
23 #ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
24 extern unsigned long max_mapnr;
25 #endif
26 
27 extern unsigned long num_physpages;
28 extern unsigned long totalram_pages;
29 extern void * high_memory;
30 extern int page_cluster;
31 
32 #ifdef CONFIG_SYSCTL
33 extern int sysctl_legacy_va_layout;
34 #else
35 #define sysctl_legacy_va_layout 0
36 #endif
37 
38 #include <asm/page.h>
39 #include <asm/pgtable.h>
40 #include <asm/processor.h>
41 
42 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
43 
44 /* to align the pointer to the (next) page boundary */
45 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
46 
47 /*
48  * Linux kernel virtual memory manager primitives.
49  * The idea being to have a "virtual" mm in the same way
50  * we have a virtual fs - giving a cleaner interface to the
51  * mm details, and allowing different kinds of memory mappings
52  * (from shared memory to executable loading to arbitrary
53  * mmap() functions).
54  */
55 
56 extern struct kmem_cache *vm_area_cachep;
57 
58 #ifndef CONFIG_MMU
59 extern struct rb_root nommu_region_tree;
60 extern struct rw_semaphore nommu_region_sem;
61 
62 extern unsigned int kobjsize(const void *objp);
63 #endif
64 
65 /*
66  * vm_flags in vm_area_struct, see mm_types.h.
67  */
68 #define VM_READ		0x00000001	/* currently active flags */
69 #define VM_WRITE	0x00000002
70 #define VM_EXEC		0x00000004
71 #define VM_SHARED	0x00000008
72 
73 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
74 #define VM_MAYREAD	0x00000010	/* limits for mprotect() etc */
75 #define VM_MAYWRITE	0x00000020
76 #define VM_MAYEXEC	0x00000040
77 #define VM_MAYSHARE	0x00000080
78 
79 #define VM_GROWSDOWN	0x00000100	/* general info on the segment */
80 #define VM_GROWSUP	0x00000200
81 #define VM_PFNMAP	0x00000400	/* Page-ranges managed without "struct page", just pure PFN */
82 #define VM_DENYWRITE	0x00000800	/* ETXTBSY on write attempts.. */
83 
84 #define VM_EXECUTABLE	0x00001000
85 #define VM_LOCKED	0x00002000
86 #define VM_IO           0x00004000	/* Memory mapped I/O or similar */
87 
88 					/* Used by sys_madvise() */
89 #define VM_SEQ_READ	0x00008000	/* App will access data sequentially */
90 #define VM_RAND_READ	0x00010000	/* App will not benefit from clustered reads */
91 
92 #define VM_DONTCOPY	0x00020000      /* Do not copy this vma on fork */
93 #define VM_DONTEXPAND	0x00040000	/* Cannot expand with mremap() */
94 #define VM_RESERVED	0x00080000	/* Count as reserved_vm like IO */
95 #define VM_ACCOUNT	0x00100000	/* Is a VM accounted object */
96 #define VM_NORESERVE	0x00200000	/* should the VM suppress accounting */
97 #define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */
98 #define VM_NONLINEAR	0x00800000	/* Is non-linear (remap_file_pages) */
99 #define VM_MAPPED_COPY	0x01000000	/* T if mapped copy of data (nommu mmap) */
100 #define VM_INSERTPAGE	0x02000000	/* The vma has had "vm_insert_page()" done on it */
101 #define VM_ALWAYSDUMP	0x04000000	/* Always include in core dumps */
102 
103 #define VM_CAN_NONLINEAR 0x08000000	/* Has ->fault & does nonlinear pages */
104 #define VM_MIXEDMAP	0x10000000	/* Can contain "struct page" and pure PFN pages */
105 #define VM_SAO		0x20000000	/* Strong Access Ordering (powerpc) */
106 #define VM_PFN_AT_MMAP	0x40000000	/* PFNMAP vma that is fully mapped at mmap time */
107 #define VM_MERGEABLE	0x80000000	/* KSM may merge identical pages */
108 
109 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
110 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
111 #endif
112 
113 #ifdef CONFIG_STACK_GROWSUP
114 #define VM_STACK_FLAGS	(VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
115 #else
116 #define VM_STACK_FLAGS	(VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
117 #endif
118 
119 #define VM_READHINTMASK			(VM_SEQ_READ | VM_RAND_READ)
120 #define VM_ClearReadHint(v)		(v)->vm_flags &= ~VM_READHINTMASK
121 #define VM_NormalReadHint(v)		(!((v)->vm_flags & VM_READHINTMASK))
122 #define VM_SequentialReadHint(v)	((v)->vm_flags & VM_SEQ_READ)
123 #define VM_RandomReadHint(v)		((v)->vm_flags & VM_RAND_READ)
124 
125 /*
126  * special vmas that are non-mergable, non-mlock()able
127  */
128 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
129 
130 /*
131  * mapping from the currently active vm_flags protection bits (the
132  * low four bits) to a page protection mask..
133  */
134 extern pgprot_t protection_map[16];
135 
136 #define FAULT_FLAG_WRITE	0x01	/* Fault was a write access */
137 #define FAULT_FLAG_NONLINEAR	0x02	/* Fault was via a nonlinear mapping */
138 #define FAULT_FLAG_MKWRITE	0x04	/* Fault was mkwrite of existing pte */
139 
140 /*
141  * This interface is used by x86 PAT code to identify a pfn mapping that is
142  * linear over entire vma. This is to optimize PAT code that deals with
143  * marking the physical region with a particular prot. This is not for generic
144  * mm use. Note also that this check will not work if the pfn mapping is
145  * linear for a vma starting at physical address 0. In which case PAT code
146  * falls back to slow path of reserving physical range page by page.
147  */
148 static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
149 {
150 	return (vma->vm_flags & VM_PFN_AT_MMAP);
151 }
152 
153 static inline int is_pfn_mapping(struct vm_area_struct *vma)
154 {
155 	return (vma->vm_flags & VM_PFNMAP);
156 }
157 
158 /*
159  * vm_fault is filled by the the pagefault handler and passed to the vma's
160  * ->fault function. The vma's ->fault is responsible for returning a bitmask
161  * of VM_FAULT_xxx flags that give details about how the fault was handled.
162  *
163  * pgoff should be used in favour of virtual_address, if possible. If pgoff
164  * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
165  * mapping support.
166  */
167 struct vm_fault {
168 	unsigned int flags;		/* FAULT_FLAG_xxx flags */
169 	pgoff_t pgoff;			/* Logical page offset based on vma */
170 	void __user *virtual_address;	/* Faulting virtual address */
171 
172 	struct page *page;		/* ->fault handlers should return a
173 					 * page here, unless VM_FAULT_NOPAGE
174 					 * is set (which is also implied by
175 					 * VM_FAULT_ERROR).
176 					 */
177 };
178 
179 /*
180  * These are the virtual MM functions - opening of an area, closing and
181  * unmapping it (needed to keep files on disk up-to-date etc), pointer
182  * to the functions called when a no-page or a wp-page exception occurs.
183  */
184 struct vm_operations_struct {
185 	void (*open)(struct vm_area_struct * area);
186 	void (*close)(struct vm_area_struct * area);
187 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
188 
189 	/* notification that a previously read-only page is about to become
190 	 * writable, if an error is returned it will cause a SIGBUS */
191 	int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
192 
193 	/* called by access_process_vm when get_user_pages() fails, typically
194 	 * for use by special VMAs that can switch between memory and hardware
195 	 */
196 	int (*access)(struct vm_area_struct *vma, unsigned long addr,
197 		      void *buf, int len, int write);
198 #ifdef CONFIG_NUMA
199 	/*
200 	 * set_policy() op must add a reference to any non-NULL @new mempolicy
201 	 * to hold the policy upon return.  Caller should pass NULL @new to
202 	 * remove a policy and fall back to surrounding context--i.e. do not
203 	 * install a MPOL_DEFAULT policy, nor the task or system default
204 	 * mempolicy.
205 	 */
206 	int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
207 
208 	/*
209 	 * get_policy() op must add reference [mpol_get()] to any policy at
210 	 * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
211 	 * in mm/mempolicy.c will do this automatically.
212 	 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
213 	 * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
214 	 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
215 	 * must return NULL--i.e., do not "fallback" to task or system default
216 	 * policy.
217 	 */
218 	struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
219 					unsigned long addr);
220 	int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
221 		const nodemask_t *to, unsigned long flags);
222 #endif
223 };
224 
225 struct mmu_gather;
226 struct inode;
227 
228 #define page_private(page)		((page)->private)
229 #define set_page_private(page, v)	((page)->private = (v))
230 
231 /*
232  * FIXME: take this include out, include page-flags.h in
233  * files which need it (119 of them)
234  */
235 #include <linux/page-flags.h>
236 
237 /*
238  * Methods to modify the page usage count.
239  *
240  * What counts for a page usage:
241  * - cache mapping   (page->mapping)
242  * - private data    (page->private)
243  * - page mapped in a task's page tables, each mapping
244  *   is counted separately
245  *
246  * Also, many kernel routines increase the page count before a critical
247  * routine so they can be sure the page doesn't go away from under them.
248  */
249 
250 /*
251  * Drop a ref, return true if the refcount fell to zero (the page has no users)
252  */
253 static inline int put_page_testzero(struct page *page)
254 {
255 	VM_BUG_ON(atomic_read(&page->_count) == 0);
256 	return atomic_dec_and_test(&page->_count);
257 }
258 
259 /*
260  * Try to grab a ref unless the page has a refcount of zero, return false if
261  * that is the case.
262  */
263 static inline int get_page_unless_zero(struct page *page)
264 {
265 	return atomic_inc_not_zero(&page->_count);
266 }
267 
268 extern int page_is_ram(unsigned long pfn);
269 
270 /* Support for virtually mapped pages */
271 struct page *vmalloc_to_page(const void *addr);
272 unsigned long vmalloc_to_pfn(const void *addr);
273 
274 /*
275  * Determine if an address is within the vmalloc range
276  *
277  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
278  * is no special casing required.
279  */
280 static inline int is_vmalloc_addr(const void *x)
281 {
282 #ifdef CONFIG_MMU
283 	unsigned long addr = (unsigned long)x;
284 
285 	return addr >= VMALLOC_START && addr < VMALLOC_END;
286 #else
287 	return 0;
288 #endif
289 }
290 #ifdef CONFIG_MMU
291 extern int is_vmalloc_or_module_addr(const void *x);
292 #else
293 static inline int is_vmalloc_or_module_addr(const void *x)
294 {
295 	return 0;
296 }
297 #endif
298 
299 static inline struct page *compound_head(struct page *page)
300 {
301 	if (unlikely(PageTail(page)))
302 		return page->first_page;
303 	return page;
304 }
305 
306 static inline int page_count(struct page *page)
307 {
308 	return atomic_read(&compound_head(page)->_count);
309 }
310 
311 static inline void get_page(struct page *page)
312 {
313 	page = compound_head(page);
314 	VM_BUG_ON(atomic_read(&page->_count) == 0);
315 	atomic_inc(&page->_count);
316 }
317 
318 static inline struct page *virt_to_head_page(const void *x)
319 {
320 	struct page *page = virt_to_page(x);
321 	return compound_head(page);
322 }
323 
324 /*
325  * Setup the page count before being freed into the page allocator for
326  * the first time (boot or memory hotplug)
327  */
328 static inline void init_page_count(struct page *page)
329 {
330 	atomic_set(&page->_count, 1);
331 }
332 
333 void put_page(struct page *page);
334 void put_pages_list(struct list_head *pages);
335 
336 void split_page(struct page *page, unsigned int order);
337 
338 /*
339  * Compound pages have a destructor function.  Provide a
340  * prototype for that function and accessor functions.
341  * These are _only_ valid on the head of a PG_compound page.
342  */
343 typedef void compound_page_dtor(struct page *);
344 
345 static inline void set_compound_page_dtor(struct page *page,
346 						compound_page_dtor *dtor)
347 {
348 	page[1].lru.next = (void *)dtor;
349 }
350 
351 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
352 {
353 	return (compound_page_dtor *)page[1].lru.next;
354 }
355 
356 static inline int compound_order(struct page *page)
357 {
358 	if (!PageHead(page))
359 		return 0;
360 	return (unsigned long)page[1].lru.prev;
361 }
362 
363 static inline void set_compound_order(struct page *page, unsigned long order)
364 {
365 	page[1].lru.prev = (void *)order;
366 }
367 
368 /*
369  * Multiple processes may "see" the same page. E.g. for untouched
370  * mappings of /dev/null, all processes see the same page full of
371  * zeroes, and text pages of executables and shared libraries have
372  * only one copy in memory, at most, normally.
373  *
374  * For the non-reserved pages, page_count(page) denotes a reference count.
375  *   page_count() == 0 means the page is free. page->lru is then used for
376  *   freelist management in the buddy allocator.
377  *   page_count() > 0  means the page has been allocated.
378  *
379  * Pages are allocated by the slab allocator in order to provide memory
380  * to kmalloc and kmem_cache_alloc. In this case, the management of the
381  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
382  * unless a particular usage is carefully commented. (the responsibility of
383  * freeing the kmalloc memory is the caller's, of course).
384  *
385  * A page may be used by anyone else who does a __get_free_page().
386  * In this case, page_count still tracks the references, and should only
387  * be used through the normal accessor functions. The top bits of page->flags
388  * and page->virtual store page management information, but all other fields
389  * are unused and could be used privately, carefully. The management of this
390  * page is the responsibility of the one who allocated it, and those who have
391  * subsequently been given references to it.
392  *
393  * The other pages (we may call them "pagecache pages") are completely
394  * managed by the Linux memory manager: I/O, buffers, swapping etc.
395  * The following discussion applies only to them.
396  *
397  * A pagecache page contains an opaque `private' member, which belongs to the
398  * page's address_space. Usually, this is the address of a circular list of
399  * the page's disk buffers. PG_private must be set to tell the VM to call
400  * into the filesystem to release these pages.
401  *
402  * A page may belong to an inode's memory mapping. In this case, page->mapping
403  * is the pointer to the inode, and page->index is the file offset of the page,
404  * in units of PAGE_CACHE_SIZE.
405  *
406  * If pagecache pages are not associated with an inode, they are said to be
407  * anonymous pages. These may become associated with the swapcache, and in that
408  * case PG_swapcache is set, and page->private is an offset into the swapcache.
409  *
410  * In either case (swapcache or inode backed), the pagecache itself holds one
411  * reference to the page. Setting PG_private should also increment the
412  * refcount. The each user mapping also has a reference to the page.
413  *
414  * The pagecache pages are stored in a per-mapping radix tree, which is
415  * rooted at mapping->page_tree, and indexed by offset.
416  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
417  * lists, we instead now tag pages as dirty/writeback in the radix tree.
418  *
419  * All pagecache pages may be subject to I/O:
420  * - inode pages may need to be read from disk,
421  * - inode pages which have been modified and are MAP_SHARED may need
422  *   to be written back to the inode on disk,
423  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
424  *   modified may need to be swapped out to swap space and (later) to be read
425  *   back into memory.
426  */
427 
428 /*
429  * The zone field is never updated after free_area_init_core()
430  * sets it, so none of the operations on it need to be atomic.
431  */
432 
433 
434 /*
435  * page->flags layout:
436  *
437  * There are three possibilities for how page->flags get
438  * laid out.  The first is for the normal case, without
439  * sparsemem.  The second is for sparsemem when there is
440  * plenty of space for node and section.  The last is when
441  * we have run out of space and have to fall back to an
442  * alternate (slower) way of determining the node.
443  *
444  * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
445  * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
446  * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
447  */
448 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
449 #define SECTIONS_WIDTH		SECTIONS_SHIFT
450 #else
451 #define SECTIONS_WIDTH		0
452 #endif
453 
454 #define ZONES_WIDTH		ZONES_SHIFT
455 
456 #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
457 #define NODES_WIDTH		NODES_SHIFT
458 #else
459 #ifdef CONFIG_SPARSEMEM_VMEMMAP
460 #error "Vmemmap: No space for nodes field in page flags"
461 #endif
462 #define NODES_WIDTH		0
463 #endif
464 
465 /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
466 #define SECTIONS_PGOFF		((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
467 #define NODES_PGOFF		(SECTIONS_PGOFF - NODES_WIDTH)
468 #define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
469 
470 /*
471  * We are going to use the flags for the page to node mapping if its in
472  * there.  This includes the case where there is no node, so it is implicit.
473  */
474 #if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
475 #define NODE_NOT_IN_PAGE_FLAGS
476 #endif
477 
478 #ifndef PFN_SECTION_SHIFT
479 #define PFN_SECTION_SHIFT 0
480 #endif
481 
482 /*
483  * Define the bit shifts to access each section.  For non-existant
484  * sections we define the shift as 0; that plus a 0 mask ensures
485  * the compiler will optimise away reference to them.
486  */
487 #define SECTIONS_PGSHIFT	(SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
488 #define NODES_PGSHIFT		(NODES_PGOFF * (NODES_WIDTH != 0))
489 #define ZONES_PGSHIFT		(ZONES_PGOFF * (ZONES_WIDTH != 0))
490 
491 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
492 #ifdef NODE_NOT_IN_PAGEFLAGS
493 #define ZONEID_SHIFT		(SECTIONS_SHIFT + ZONES_SHIFT)
494 #define ZONEID_PGOFF		((SECTIONS_PGOFF < ZONES_PGOFF)? \
495 						SECTIONS_PGOFF : ZONES_PGOFF)
496 #else
497 #define ZONEID_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
498 #define ZONEID_PGOFF		((NODES_PGOFF < ZONES_PGOFF)? \
499 						NODES_PGOFF : ZONES_PGOFF)
500 #endif
501 
502 #define ZONEID_PGSHIFT		(ZONEID_PGOFF * (ZONEID_SHIFT != 0))
503 
504 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
505 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
506 #endif
507 
508 #define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
509 #define NODES_MASK		((1UL << NODES_WIDTH) - 1)
510 #define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
511 #define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
512 
513 static inline enum zone_type page_zonenum(struct page *page)
514 {
515 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
516 }
517 
518 /*
519  * The identification function is only used by the buddy allocator for
520  * determining if two pages could be buddies. We are not really
521  * identifying a zone since we could be using a the section number
522  * id if we have not node id available in page flags.
523  * We guarantee only that it will return the same value for two
524  * combinable pages in a zone.
525  */
526 static inline int page_zone_id(struct page *page)
527 {
528 	return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
529 }
530 
531 static inline int zone_to_nid(struct zone *zone)
532 {
533 #ifdef CONFIG_NUMA
534 	return zone->node;
535 #else
536 	return 0;
537 #endif
538 }
539 
540 #ifdef NODE_NOT_IN_PAGE_FLAGS
541 extern int page_to_nid(struct page *page);
542 #else
543 static inline int page_to_nid(struct page *page)
544 {
545 	return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
546 }
547 #endif
548 
549 static inline struct zone *page_zone(struct page *page)
550 {
551 	return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
552 }
553 
554 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
555 static inline unsigned long page_to_section(struct page *page)
556 {
557 	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
558 }
559 #endif
560 
561 static inline void set_page_zone(struct page *page, enum zone_type zone)
562 {
563 	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
564 	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
565 }
566 
567 static inline void set_page_node(struct page *page, unsigned long node)
568 {
569 	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
570 	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
571 }
572 
573 static inline void set_page_section(struct page *page, unsigned long section)
574 {
575 	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
576 	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
577 }
578 
579 static inline void set_page_links(struct page *page, enum zone_type zone,
580 	unsigned long node, unsigned long pfn)
581 {
582 	set_page_zone(page, zone);
583 	set_page_node(page, node);
584 	set_page_section(page, pfn_to_section_nr(pfn));
585 }
586 
587 /*
588  * Some inline functions in vmstat.h depend on page_zone()
589  */
590 #include <linux/vmstat.h>
591 
592 static __always_inline void *lowmem_page_address(struct page *page)
593 {
594 	return __va(page_to_pfn(page) << PAGE_SHIFT);
595 }
596 
597 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
598 #define HASHED_PAGE_VIRTUAL
599 #endif
600 
601 #if defined(WANT_PAGE_VIRTUAL)
602 #define page_address(page) ((page)->virtual)
603 #define set_page_address(page, address)			\
604 	do {						\
605 		(page)->virtual = (address);		\
606 	} while(0)
607 #define page_address_init()  do { } while(0)
608 #endif
609 
610 #if defined(HASHED_PAGE_VIRTUAL)
611 void *page_address(struct page *page);
612 void set_page_address(struct page *page, void *virtual);
613 void page_address_init(void);
614 #endif
615 
616 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
617 #define page_address(page) lowmem_page_address(page)
618 #define set_page_address(page, address)  do { } while(0)
619 #define page_address_init()  do { } while(0)
620 #endif
621 
622 /*
623  * On an anonymous page mapped into a user virtual memory area,
624  * page->mapping points to its anon_vma, not to a struct address_space;
625  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
626  *
627  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
628  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
629  * and then page->mapping points, not to an anon_vma, but to a private
630  * structure which KSM associates with that merged page.  See ksm.h.
631  *
632  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
633  *
634  * Please note that, confusingly, "page_mapping" refers to the inode
635  * address_space which maps the page from disk; whereas "page_mapped"
636  * refers to user virtual address space into which the page is mapped.
637  */
638 #define PAGE_MAPPING_ANON	1
639 #define PAGE_MAPPING_KSM	2
640 #define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
641 
642 extern struct address_space swapper_space;
643 static inline struct address_space *page_mapping(struct page *page)
644 {
645 	struct address_space *mapping = page->mapping;
646 
647 	VM_BUG_ON(PageSlab(page));
648 	if (unlikely(PageSwapCache(page)))
649 		mapping = &swapper_space;
650 	else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
651 		mapping = NULL;
652 	return mapping;
653 }
654 
655 /* Neutral page->mapping pointer to address_space or anon_vma or other */
656 static inline void *page_rmapping(struct page *page)
657 {
658 	return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
659 }
660 
661 static inline int PageAnon(struct page *page)
662 {
663 	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
664 }
665 
666 /*
667  * Return the pagecache index of the passed page.  Regular pagecache pages
668  * use ->index whereas swapcache pages use ->private
669  */
670 static inline pgoff_t page_index(struct page *page)
671 {
672 	if (unlikely(PageSwapCache(page)))
673 		return page_private(page);
674 	return page->index;
675 }
676 
677 /*
678  * The atomic page->_mapcount, like _count, starts from -1:
679  * so that transitions both from it and to it can be tracked,
680  * using atomic_inc_and_test and atomic_add_negative(-1).
681  */
682 static inline void reset_page_mapcount(struct page *page)
683 {
684 	atomic_set(&(page)->_mapcount, -1);
685 }
686 
687 static inline int page_mapcount(struct page *page)
688 {
689 	return atomic_read(&(page)->_mapcount) + 1;
690 }
691 
692 /*
693  * Return true if this page is mapped into pagetables.
694  */
695 static inline int page_mapped(struct page *page)
696 {
697 	return atomic_read(&(page)->_mapcount) >= 0;
698 }
699 
700 /*
701  * Different kinds of faults, as returned by handle_mm_fault().
702  * Used to decide whether a process gets delivered SIGBUS or
703  * just gets major/minor fault counters bumped up.
704  */
705 
706 #define VM_FAULT_MINOR	0 /* For backwards compat. Remove me quickly. */
707 
708 #define VM_FAULT_OOM	0x0001
709 #define VM_FAULT_SIGBUS	0x0002
710 #define VM_FAULT_MAJOR	0x0004
711 #define VM_FAULT_WRITE	0x0008	/* Special case for get_user_pages */
712 #define VM_FAULT_HWPOISON 0x0010	/* Hit poisoned page */
713 
714 #define VM_FAULT_NOPAGE	0x0100	/* ->fault installed the pte, not return page */
715 #define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
716 
717 #define VM_FAULT_ERROR	(VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
718 
719 /*
720  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
721  */
722 extern void pagefault_out_of_memory(void);
723 
724 #define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
725 
726 extern void show_free_areas(void);
727 
728 int shmem_lock(struct file *file, int lock, struct user_struct *user);
729 struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags);
730 int shmem_zero_setup(struct vm_area_struct *);
731 
732 #ifndef CONFIG_MMU
733 extern unsigned long shmem_get_unmapped_area(struct file *file,
734 					     unsigned long addr,
735 					     unsigned long len,
736 					     unsigned long pgoff,
737 					     unsigned long flags);
738 #endif
739 
740 extern int can_do_mlock(void);
741 extern int user_shm_lock(size_t, struct user_struct *);
742 extern void user_shm_unlock(size_t, struct user_struct *);
743 
744 /*
745  * Parameter block passed down to zap_pte_range in exceptional cases.
746  */
747 struct zap_details {
748 	struct vm_area_struct *nonlinear_vma;	/* Check page->index if set */
749 	struct address_space *check_mapping;	/* Check page->mapping if set */
750 	pgoff_t	first_index;			/* Lowest page->index to unmap */
751 	pgoff_t last_index;			/* Highest page->index to unmap */
752 	spinlock_t *i_mmap_lock;		/* For unmap_mapping_range: */
753 	unsigned long truncate_count;		/* Compare vm_truncate_count */
754 };
755 
756 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
757 		pte_t pte);
758 
759 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
760 		unsigned long size);
761 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
762 		unsigned long size, struct zap_details *);
763 unsigned long unmap_vmas(struct mmu_gather **tlb,
764 		struct vm_area_struct *start_vma, unsigned long start_addr,
765 		unsigned long end_addr, unsigned long *nr_accounted,
766 		struct zap_details *);
767 
768 /**
769  * mm_walk - callbacks for walk_page_range
770  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
771  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
772  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
773  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
774  * @pte_hole: if set, called for each hole at all levels
775  * @hugetlb_entry: if set, called for each hugetlb entry
776  *
777  * (see walk_page_range for more details)
778  */
779 struct mm_walk {
780 	int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
781 	int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
782 	int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
783 	int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
784 	int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
785 	int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long,
786 			     struct mm_walk *);
787 	struct mm_struct *mm;
788 	void *private;
789 };
790 
791 int walk_page_range(unsigned long addr, unsigned long end,
792 		struct mm_walk *walk);
793 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
794 		unsigned long end, unsigned long floor, unsigned long ceiling);
795 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
796 			struct vm_area_struct *vma);
797 void unmap_mapping_range(struct address_space *mapping,
798 		loff_t const holebegin, loff_t const holelen, int even_cows);
799 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
800 	unsigned long *pfn);
801 int follow_phys(struct vm_area_struct *vma, unsigned long address,
802 		unsigned int flags, unsigned long *prot, resource_size_t *phys);
803 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
804 			void *buf, int len, int write);
805 
806 static inline void unmap_shared_mapping_range(struct address_space *mapping,
807 		loff_t const holebegin, loff_t const holelen)
808 {
809 	unmap_mapping_range(mapping, holebegin, holelen, 0);
810 }
811 
812 extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
813 extern int vmtruncate(struct inode *inode, loff_t offset);
814 extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
815 
816 int truncate_inode_page(struct address_space *mapping, struct page *page);
817 int generic_error_remove_page(struct address_space *mapping, struct page *page);
818 
819 int invalidate_inode_page(struct page *page);
820 
821 #ifdef CONFIG_MMU
822 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
823 			unsigned long address, unsigned int flags);
824 #else
825 static inline int handle_mm_fault(struct mm_struct *mm,
826 			struct vm_area_struct *vma, unsigned long address,
827 			unsigned int flags)
828 {
829 	/* should never happen if there's no MMU */
830 	BUG();
831 	return VM_FAULT_SIGBUS;
832 }
833 #endif
834 
835 extern int make_pages_present(unsigned long addr, unsigned long end);
836 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
837 
838 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
839 			unsigned long start, int nr_pages, int write, int force,
840 			struct page **pages, struct vm_area_struct **vmas);
841 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
842 			struct page **pages);
843 struct page *get_dump_page(unsigned long addr);
844 
845 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
846 extern void do_invalidatepage(struct page *page, unsigned long offset);
847 
848 int __set_page_dirty_nobuffers(struct page *page);
849 int __set_page_dirty_no_writeback(struct page *page);
850 int redirty_page_for_writepage(struct writeback_control *wbc,
851 				struct page *page);
852 void account_page_dirtied(struct page *page, struct address_space *mapping);
853 int set_page_dirty(struct page *page);
854 int set_page_dirty_lock(struct page *page);
855 int clear_page_dirty_for_io(struct page *page);
856 
857 extern unsigned long move_page_tables(struct vm_area_struct *vma,
858 		unsigned long old_addr, struct vm_area_struct *new_vma,
859 		unsigned long new_addr, unsigned long len);
860 extern unsigned long do_mremap(unsigned long addr,
861 			       unsigned long old_len, unsigned long new_len,
862 			       unsigned long flags, unsigned long new_addr);
863 extern int mprotect_fixup(struct vm_area_struct *vma,
864 			  struct vm_area_struct **pprev, unsigned long start,
865 			  unsigned long end, unsigned long newflags);
866 
867 /*
868  * doesn't attempt to fault and will return short.
869  */
870 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
871 			  struct page **pages);
872 
873 /*
874  * A callback you can register to apply pressure to ageable caches.
875  *
876  * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
877  * look through the least-recently-used 'nr_to_scan' entries and
878  * attempt to free them up.  It should return the number of objects
879  * which remain in the cache.  If it returns -1, it means it cannot do
880  * any scanning at this time (eg. there is a risk of deadlock).
881  *
882  * The 'gfpmask' refers to the allocation we are currently trying to
883  * fulfil.
884  *
885  * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
886  * querying the cache size, so a fastpath for that case is appropriate.
887  */
888 struct shrinker {
889 	int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
890 	int seeks;	/* seeks to recreate an obj */
891 
892 	/* These are for internal use */
893 	struct list_head list;
894 	long nr;	/* objs pending delete */
895 };
896 #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
897 extern void register_shrinker(struct shrinker *);
898 extern void unregister_shrinker(struct shrinker *);
899 
900 int vma_wants_writenotify(struct vm_area_struct *vma);
901 
902 extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
903 
904 #ifdef __PAGETABLE_PUD_FOLDED
905 static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
906 						unsigned long address)
907 {
908 	return 0;
909 }
910 #else
911 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
912 #endif
913 
914 #ifdef __PAGETABLE_PMD_FOLDED
915 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
916 						unsigned long address)
917 {
918 	return 0;
919 }
920 #else
921 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
922 #endif
923 
924 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
925 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
926 
927 /*
928  * The following ifdef needed to get the 4level-fixup.h header to work.
929  * Remove it when 4level-fixup.h has been removed.
930  */
931 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
932 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
933 {
934 	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
935 		NULL: pud_offset(pgd, address);
936 }
937 
938 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
939 {
940 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
941 		NULL: pmd_offset(pud, address);
942 }
943 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
944 
945 #if USE_SPLIT_PTLOCKS
946 /*
947  * We tuck a spinlock to guard each pagetable page into its struct page,
948  * at page->private, with BUILD_BUG_ON to make sure that this will not
949  * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
950  * When freeing, reset page->mapping so free_pages_check won't complain.
951  */
952 #define __pte_lockptr(page)	&((page)->ptl)
953 #define pte_lock_init(_page)	do {					\
954 	spin_lock_init(__pte_lockptr(_page));				\
955 } while (0)
956 #define pte_lock_deinit(page)	((page)->mapping = NULL)
957 #define pte_lockptr(mm, pmd)	({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
958 #else	/* !USE_SPLIT_PTLOCKS */
959 /*
960  * We use mm->page_table_lock to guard all pagetable pages of the mm.
961  */
962 #define pte_lock_init(page)	do {} while (0)
963 #define pte_lock_deinit(page)	do {} while (0)
964 #define pte_lockptr(mm, pmd)	({(void)(pmd); &(mm)->page_table_lock;})
965 #endif /* USE_SPLIT_PTLOCKS */
966 
967 static inline void pgtable_page_ctor(struct page *page)
968 {
969 	pte_lock_init(page);
970 	inc_zone_page_state(page, NR_PAGETABLE);
971 }
972 
973 static inline void pgtable_page_dtor(struct page *page)
974 {
975 	pte_lock_deinit(page);
976 	dec_zone_page_state(page, NR_PAGETABLE);
977 }
978 
979 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
980 ({							\
981 	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
982 	pte_t *__pte = pte_offset_map(pmd, address);	\
983 	*(ptlp) = __ptl;				\
984 	spin_lock(__ptl);				\
985 	__pte;						\
986 })
987 
988 #define pte_unmap_unlock(pte, ptl)	do {		\
989 	spin_unlock(ptl);				\
990 	pte_unmap(pte);					\
991 } while (0)
992 
993 #define pte_alloc_map(mm, pmd, address)			\
994 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
995 		NULL: pte_offset_map(pmd, address))
996 
997 #define pte_alloc_map_lock(mm, pmd, address, ptlp)	\
998 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
999 		NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1000 
1001 #define pte_alloc_kernel(pmd, address)			\
1002 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1003 		NULL: pte_offset_kernel(pmd, address))
1004 
1005 extern void free_area_init(unsigned long * zones_size);
1006 extern void free_area_init_node(int nid, unsigned long * zones_size,
1007 		unsigned long zone_start_pfn, unsigned long *zholes_size);
1008 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
1009 /*
1010  * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
1011  * zones, allocate the backing mem_map and account for memory holes in a more
1012  * architecture independent manner. This is a substitute for creating the
1013  * zone_sizes[] and zholes_size[] arrays and passing them to
1014  * free_area_init_node()
1015  *
1016  * An architecture is expected to register range of page frames backed by
1017  * physical memory with add_active_range() before calling
1018  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1019  * usage, an architecture is expected to do something like
1020  *
1021  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1022  * 							 max_highmem_pfn};
1023  * for_each_valid_physical_page_range()
1024  * 	add_active_range(node_id, start_pfn, end_pfn)
1025  * free_area_init_nodes(max_zone_pfns);
1026  *
1027  * If the architecture guarantees that there are no holes in the ranges
1028  * registered with add_active_range(), free_bootmem_active_regions()
1029  * will call free_bootmem_node() for each registered physical page range.
1030  * Similarly sparse_memory_present_with_active_regions() calls
1031  * memory_present() for each range when SPARSEMEM is enabled.
1032  *
1033  * See mm/page_alloc.c for more information on each function exposed by
1034  * CONFIG_ARCH_POPULATES_NODE_MAP
1035  */
1036 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1037 extern void add_active_range(unsigned int nid, unsigned long start_pfn,
1038 					unsigned long end_pfn);
1039 extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
1040 					unsigned long end_pfn);
1041 extern void remove_all_active_ranges(void);
1042 void sort_node_map(void);
1043 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1044 						unsigned long end_pfn);
1045 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1046 						unsigned long end_pfn);
1047 extern void get_pfn_range_for_nid(unsigned int nid,
1048 			unsigned long *start_pfn, unsigned long *end_pfn);
1049 extern unsigned long find_min_pfn_with_active_regions(void);
1050 extern void free_bootmem_with_active_regions(int nid,
1051 						unsigned long max_low_pfn);
1052 typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
1053 extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
1054 extern void sparse_memory_present_with_active_regions(int nid);
1055 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1056 
1057 #if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \
1058     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1059 static inline int __early_pfn_to_nid(unsigned long pfn)
1060 {
1061 	return 0;
1062 }
1063 #else
1064 /* please see mm/page_alloc.c */
1065 extern int __meminit early_pfn_to_nid(unsigned long pfn);
1066 #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1067 /* there is a per-arch backend function. */
1068 extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1069 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1070 #endif
1071 
1072 extern void set_dma_reserve(unsigned long new_dma_reserve);
1073 extern void memmap_init_zone(unsigned long, int, unsigned long,
1074 				unsigned long, enum memmap_context);
1075 extern void setup_per_zone_wmarks(void);
1076 extern void calculate_zone_inactive_ratio(struct zone *zone);
1077 extern void mem_init(void);
1078 extern void __init mmap_init(void);
1079 extern void show_mem(void);
1080 extern void si_meminfo(struct sysinfo * val);
1081 extern void si_meminfo_node(struct sysinfo *val, int nid);
1082 extern int after_bootmem;
1083 
1084 #ifdef CONFIG_NUMA
1085 extern void setup_per_cpu_pageset(void);
1086 #else
1087 static inline void setup_per_cpu_pageset(void) {}
1088 #endif
1089 
1090 extern void zone_pcp_update(struct zone *zone);
1091 
1092 /* nommu.c */
1093 extern atomic_long_t mmap_pages_allocated;
1094 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1095 
1096 /* prio_tree.c */
1097 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1098 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1099 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1100 struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1101 	struct prio_tree_iter *iter);
1102 
1103 #define vma_prio_tree_foreach(vma, iter, root, begin, end)	\
1104 	for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;	\
1105 		(vma = vma_prio_tree_next(vma, iter)); )
1106 
1107 static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1108 					struct list_head *list)
1109 {
1110 	vma->shared.vm_set.parent = NULL;
1111 	list_add_tail(&vma->shared.vm_set.list, list);
1112 }
1113 
1114 /* mmap.c */
1115 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1116 extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
1117 	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1118 extern struct vm_area_struct *vma_merge(struct mm_struct *,
1119 	struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1120 	unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1121 	struct mempolicy *);
1122 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1123 extern int split_vma(struct mm_struct *,
1124 	struct vm_area_struct *, unsigned long addr, int new_below);
1125 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1126 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1127 	struct rb_node **, struct rb_node *);
1128 extern void unlink_file_vma(struct vm_area_struct *);
1129 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1130 	unsigned long addr, unsigned long len, pgoff_t pgoff);
1131 extern void exit_mmap(struct mm_struct *);
1132 
1133 extern int mm_take_all_locks(struct mm_struct *mm);
1134 extern void mm_drop_all_locks(struct mm_struct *mm);
1135 
1136 #ifdef CONFIG_PROC_FS
1137 /* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1138 extern void added_exe_file_vma(struct mm_struct *mm);
1139 extern void removed_exe_file_vma(struct mm_struct *mm);
1140 #else
1141 static inline void added_exe_file_vma(struct mm_struct *mm)
1142 {}
1143 
1144 static inline void removed_exe_file_vma(struct mm_struct *mm)
1145 {}
1146 #endif /* CONFIG_PROC_FS */
1147 
1148 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1149 extern int install_special_mapping(struct mm_struct *mm,
1150 				   unsigned long addr, unsigned long len,
1151 				   unsigned long flags, struct page **pages);
1152 
1153 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1154 
1155 extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1156 	unsigned long len, unsigned long prot,
1157 	unsigned long flag, unsigned long pgoff);
1158 extern unsigned long mmap_region(struct file *file, unsigned long addr,
1159 	unsigned long len, unsigned long flags,
1160 	unsigned int vm_flags, unsigned long pgoff);
1161 
1162 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1163 	unsigned long len, unsigned long prot,
1164 	unsigned long flag, unsigned long offset)
1165 {
1166 	unsigned long ret = -EINVAL;
1167 	if ((offset + PAGE_ALIGN(len)) < offset)
1168 		goto out;
1169 	if (!(offset & ~PAGE_MASK))
1170 		ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1171 out:
1172 	return ret;
1173 }
1174 
1175 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1176 
1177 extern unsigned long do_brk(unsigned long, unsigned long);
1178 
1179 /* filemap.c */
1180 extern unsigned long page_unuse(struct page *);
1181 extern void truncate_inode_pages(struct address_space *, loff_t);
1182 extern void truncate_inode_pages_range(struct address_space *,
1183 				       loff_t lstart, loff_t lend);
1184 
1185 /* generic vm_area_ops exported for stackable file systems */
1186 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1187 
1188 /* mm/page-writeback.c */
1189 int write_one_page(struct page *page, int wait);
1190 void task_dirty_inc(struct task_struct *tsk);
1191 
1192 /* readahead.c */
1193 #define VM_MAX_READAHEAD	128	/* kbytes */
1194 #define VM_MIN_READAHEAD	16	/* kbytes (includes current page) */
1195 
1196 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1197 			pgoff_t offset, unsigned long nr_to_read);
1198 
1199 void page_cache_sync_readahead(struct address_space *mapping,
1200 			       struct file_ra_state *ra,
1201 			       struct file *filp,
1202 			       pgoff_t offset,
1203 			       unsigned long size);
1204 
1205 void page_cache_async_readahead(struct address_space *mapping,
1206 				struct file_ra_state *ra,
1207 				struct file *filp,
1208 				struct page *pg,
1209 				pgoff_t offset,
1210 				unsigned long size);
1211 
1212 unsigned long max_sane_readahead(unsigned long nr);
1213 unsigned long ra_submit(struct file_ra_state *ra,
1214 			struct address_space *mapping,
1215 			struct file *filp);
1216 
1217 /* Do stack extension */
1218 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1219 #ifdef CONFIG_IA64
1220 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1221 #endif
1222 extern int expand_stack_downwards(struct vm_area_struct *vma,
1223 				  unsigned long address);
1224 
1225 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1226 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1227 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1228 					     struct vm_area_struct **pprev);
1229 
1230 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1231    NULL if none.  Assume start_addr < end_addr. */
1232 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1233 {
1234 	struct vm_area_struct * vma = find_vma(mm,start_addr);
1235 
1236 	if (vma && end_addr <= vma->vm_start)
1237 		vma = NULL;
1238 	return vma;
1239 }
1240 
1241 static inline unsigned long vma_pages(struct vm_area_struct *vma)
1242 {
1243 	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1244 }
1245 
1246 pgprot_t vm_get_page_prot(unsigned long vm_flags);
1247 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1248 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1249 			unsigned long pfn, unsigned long size, pgprot_t);
1250 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1251 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1252 			unsigned long pfn);
1253 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1254 			unsigned long pfn);
1255 
1256 struct page *follow_page(struct vm_area_struct *, unsigned long address,
1257 			unsigned int foll_flags);
1258 #define FOLL_WRITE	0x01	/* check pte is writable */
1259 #define FOLL_TOUCH	0x02	/* mark page accessed */
1260 #define FOLL_GET	0x04	/* do get_page on page */
1261 #define FOLL_DUMP	0x08	/* give error on hole if it would be zero */
1262 #define FOLL_FORCE	0x10	/* get_user_pages read/write w/o permission */
1263 
1264 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1265 			void *data);
1266 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1267 			       unsigned long size, pte_fn_t fn, void *data);
1268 
1269 #ifdef CONFIG_PROC_FS
1270 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1271 #else
1272 static inline void vm_stat_account(struct mm_struct *mm,
1273 			unsigned long flags, struct file *file, long pages)
1274 {
1275 }
1276 #endif /* CONFIG_PROC_FS */
1277 
1278 #ifdef CONFIG_DEBUG_PAGEALLOC
1279 extern int debug_pagealloc_enabled;
1280 
1281 extern void kernel_map_pages(struct page *page, int numpages, int enable);
1282 
1283 static inline void enable_debug_pagealloc(void)
1284 {
1285 	debug_pagealloc_enabled = 1;
1286 }
1287 #ifdef CONFIG_HIBERNATION
1288 extern bool kernel_page_present(struct page *page);
1289 #endif /* CONFIG_HIBERNATION */
1290 #else
1291 static inline void
1292 kernel_map_pages(struct page *page, int numpages, int enable) {}
1293 static inline void enable_debug_pagealloc(void)
1294 {
1295 }
1296 #ifdef CONFIG_HIBERNATION
1297 static inline bool kernel_page_present(struct page *page) { return true; }
1298 #endif /* CONFIG_HIBERNATION */
1299 #endif
1300 
1301 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1302 #ifdef	__HAVE_ARCH_GATE_AREA
1303 int in_gate_area_no_task(unsigned long addr);
1304 int in_gate_area(struct task_struct *task, unsigned long addr);
1305 #else
1306 int in_gate_area_no_task(unsigned long addr);
1307 #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1308 #endif	/* __HAVE_ARCH_GATE_AREA */
1309 
1310 int drop_caches_sysctl_handler(struct ctl_table *, int,
1311 					void __user *, size_t *, loff_t *);
1312 unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1313 			unsigned long lru_pages);
1314 
1315 #ifndef CONFIG_MMU
1316 #define randomize_va_space 0
1317 #else
1318 extern int randomize_va_space;
1319 #endif
1320 
1321 const char * arch_vma_name(struct vm_area_struct *vma);
1322 void print_vma_addr(char *prefix, unsigned long rip);
1323 
1324 struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1325 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1326 pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1327 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1328 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1329 void *vmemmap_alloc_block(unsigned long size, int node);
1330 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1331 int vmemmap_populate_basepages(struct page *start_page,
1332 						unsigned long pages, int node);
1333 int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1334 void vmemmap_populate_print_last(void);
1335 
1336 extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
1337 				 size_t size);
1338 extern void refund_locked_memory(struct mm_struct *mm, size_t size);
1339 
1340 enum mf_flags {
1341 	MF_COUNT_INCREASED = 1 << 0,
1342 };
1343 extern void memory_failure(unsigned long pfn, int trapno);
1344 extern int __memory_failure(unsigned long pfn, int trapno, int flags);
1345 extern int unpoison_memory(unsigned long pfn);
1346 extern int sysctl_memory_failure_early_kill;
1347 extern int sysctl_memory_failure_recovery;
1348 extern void shake_page(struct page *p, int access);
1349 extern atomic_long_t mce_bad_pages;
1350 extern int soft_offline_page(struct page *page, int flags);
1351 
1352 #endif /* __KERNEL__ */
1353 #endif /* _LINUX_MM_H */
1354