xref: /linux-6.15/include/linux/mm.h (revision 266fe2f2)
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 /* Support for virtually mapped pages */
269 struct page *vmalloc_to_page(const void *addr);
270 unsigned long vmalloc_to_pfn(const void *addr);
271 
272 /*
273  * Determine if an address is within the vmalloc range
274  *
275  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
276  * is no special casing required.
277  */
278 static inline int is_vmalloc_addr(const void *x)
279 {
280 #ifdef CONFIG_MMU
281 	unsigned long addr = (unsigned long)x;
282 
283 	return addr >= VMALLOC_START && addr < VMALLOC_END;
284 #else
285 	return 0;
286 #endif
287 }
288 #ifdef CONFIG_MMU
289 extern int is_vmalloc_or_module_addr(const void *x);
290 #else
291 static inline int is_vmalloc_or_module_addr(const void *x)
292 {
293 	return 0;
294 }
295 #endif
296 
297 static inline struct page *compound_head(struct page *page)
298 {
299 	if (unlikely(PageTail(page)))
300 		return page->first_page;
301 	return page;
302 }
303 
304 static inline int page_count(struct page *page)
305 {
306 	return atomic_read(&compound_head(page)->_count);
307 }
308 
309 static inline void get_page(struct page *page)
310 {
311 	page = compound_head(page);
312 	VM_BUG_ON(atomic_read(&page->_count) == 0);
313 	atomic_inc(&page->_count);
314 }
315 
316 static inline struct page *virt_to_head_page(const void *x)
317 {
318 	struct page *page = virt_to_page(x);
319 	return compound_head(page);
320 }
321 
322 /*
323  * Setup the page count before being freed into the page allocator for
324  * the first time (boot or memory hotplug)
325  */
326 static inline void init_page_count(struct page *page)
327 {
328 	atomic_set(&page->_count, 1);
329 }
330 
331 void put_page(struct page *page);
332 void put_pages_list(struct list_head *pages);
333 
334 void split_page(struct page *page, unsigned int order);
335 
336 /*
337  * Compound pages have a destructor function.  Provide a
338  * prototype for that function and accessor functions.
339  * These are _only_ valid on the head of a PG_compound page.
340  */
341 typedef void compound_page_dtor(struct page *);
342 
343 static inline void set_compound_page_dtor(struct page *page,
344 						compound_page_dtor *dtor)
345 {
346 	page[1].lru.next = (void *)dtor;
347 }
348 
349 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
350 {
351 	return (compound_page_dtor *)page[1].lru.next;
352 }
353 
354 static inline int compound_order(struct page *page)
355 {
356 	if (!PageHead(page))
357 		return 0;
358 	return (unsigned long)page[1].lru.prev;
359 }
360 
361 static inline void set_compound_order(struct page *page, unsigned long order)
362 {
363 	page[1].lru.prev = (void *)order;
364 }
365 
366 /*
367  * Multiple processes may "see" the same page. E.g. for untouched
368  * mappings of /dev/null, all processes see the same page full of
369  * zeroes, and text pages of executables and shared libraries have
370  * only one copy in memory, at most, normally.
371  *
372  * For the non-reserved pages, page_count(page) denotes a reference count.
373  *   page_count() == 0 means the page is free. page->lru is then used for
374  *   freelist management in the buddy allocator.
375  *   page_count() > 0  means the page has been allocated.
376  *
377  * Pages are allocated by the slab allocator in order to provide memory
378  * to kmalloc and kmem_cache_alloc. In this case, the management of the
379  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
380  * unless a particular usage is carefully commented. (the responsibility of
381  * freeing the kmalloc memory is the caller's, of course).
382  *
383  * A page may be used by anyone else who does a __get_free_page().
384  * In this case, page_count still tracks the references, and should only
385  * be used through the normal accessor functions. The top bits of page->flags
386  * and page->virtual store page management information, but all other fields
387  * are unused and could be used privately, carefully. The management of this
388  * page is the responsibility of the one who allocated it, and those who have
389  * subsequently been given references to it.
390  *
391  * The other pages (we may call them "pagecache pages") are completely
392  * managed by the Linux memory manager: I/O, buffers, swapping etc.
393  * The following discussion applies only to them.
394  *
395  * A pagecache page contains an opaque `private' member, which belongs to the
396  * page's address_space. Usually, this is the address of a circular list of
397  * the page's disk buffers. PG_private must be set to tell the VM to call
398  * into the filesystem to release these pages.
399  *
400  * A page may belong to an inode's memory mapping. In this case, page->mapping
401  * is the pointer to the inode, and page->index is the file offset of the page,
402  * in units of PAGE_CACHE_SIZE.
403  *
404  * If pagecache pages are not associated with an inode, they are said to be
405  * anonymous pages. These may become associated with the swapcache, and in that
406  * case PG_swapcache is set, and page->private is an offset into the swapcache.
407  *
408  * In either case (swapcache or inode backed), the pagecache itself holds one
409  * reference to the page. Setting PG_private should also increment the
410  * refcount. The each user mapping also has a reference to the page.
411  *
412  * The pagecache pages are stored in a per-mapping radix tree, which is
413  * rooted at mapping->page_tree, and indexed by offset.
414  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
415  * lists, we instead now tag pages as dirty/writeback in the radix tree.
416  *
417  * All pagecache pages may be subject to I/O:
418  * - inode pages may need to be read from disk,
419  * - inode pages which have been modified and are MAP_SHARED may need
420  *   to be written back to the inode on disk,
421  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
422  *   modified may need to be swapped out to swap space and (later) to be read
423  *   back into memory.
424  */
425 
426 /*
427  * The zone field is never updated after free_area_init_core()
428  * sets it, so none of the operations on it need to be atomic.
429  */
430 
431 
432 /*
433  * page->flags layout:
434  *
435  * There are three possibilities for how page->flags get
436  * laid out.  The first is for the normal case, without
437  * sparsemem.  The second is for sparsemem when there is
438  * plenty of space for node and section.  The last is when
439  * we have run out of space and have to fall back to an
440  * alternate (slower) way of determining the node.
441  *
442  * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
443  * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
444  * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
445  */
446 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
447 #define SECTIONS_WIDTH		SECTIONS_SHIFT
448 #else
449 #define SECTIONS_WIDTH		0
450 #endif
451 
452 #define ZONES_WIDTH		ZONES_SHIFT
453 
454 #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
455 #define NODES_WIDTH		NODES_SHIFT
456 #else
457 #ifdef CONFIG_SPARSEMEM_VMEMMAP
458 #error "Vmemmap: No space for nodes field in page flags"
459 #endif
460 #define NODES_WIDTH		0
461 #endif
462 
463 /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
464 #define SECTIONS_PGOFF		((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
465 #define NODES_PGOFF		(SECTIONS_PGOFF - NODES_WIDTH)
466 #define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
467 
468 /*
469  * We are going to use the flags for the page to node mapping if its in
470  * there.  This includes the case where there is no node, so it is implicit.
471  */
472 #if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
473 #define NODE_NOT_IN_PAGE_FLAGS
474 #endif
475 
476 #ifndef PFN_SECTION_SHIFT
477 #define PFN_SECTION_SHIFT 0
478 #endif
479 
480 /*
481  * Define the bit shifts to access each section.  For non-existant
482  * sections we define the shift as 0; that plus a 0 mask ensures
483  * the compiler will optimise away reference to them.
484  */
485 #define SECTIONS_PGSHIFT	(SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
486 #define NODES_PGSHIFT		(NODES_PGOFF * (NODES_WIDTH != 0))
487 #define ZONES_PGSHIFT		(ZONES_PGOFF * (ZONES_WIDTH != 0))
488 
489 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
490 #ifdef NODE_NOT_IN_PAGEFLAGS
491 #define ZONEID_SHIFT		(SECTIONS_SHIFT + ZONES_SHIFT)
492 #define ZONEID_PGOFF		((SECTIONS_PGOFF < ZONES_PGOFF)? \
493 						SECTIONS_PGOFF : ZONES_PGOFF)
494 #else
495 #define ZONEID_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
496 #define ZONEID_PGOFF		((NODES_PGOFF < ZONES_PGOFF)? \
497 						NODES_PGOFF : ZONES_PGOFF)
498 #endif
499 
500 #define ZONEID_PGSHIFT		(ZONEID_PGOFF * (ZONEID_SHIFT != 0))
501 
502 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
503 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
504 #endif
505 
506 #define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
507 #define NODES_MASK		((1UL << NODES_WIDTH) - 1)
508 #define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
509 #define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
510 
511 static inline enum zone_type page_zonenum(struct page *page)
512 {
513 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
514 }
515 
516 /*
517  * The identification function is only used by the buddy allocator for
518  * determining if two pages could be buddies. We are not really
519  * identifying a zone since we could be using a the section number
520  * id if we have not node id available in page flags.
521  * We guarantee only that it will return the same value for two
522  * combinable pages in a zone.
523  */
524 static inline int page_zone_id(struct page *page)
525 {
526 	return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
527 }
528 
529 static inline int zone_to_nid(struct zone *zone)
530 {
531 #ifdef CONFIG_NUMA
532 	return zone->node;
533 #else
534 	return 0;
535 #endif
536 }
537 
538 #ifdef NODE_NOT_IN_PAGE_FLAGS
539 extern int page_to_nid(struct page *page);
540 #else
541 static inline int page_to_nid(struct page *page)
542 {
543 	return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
544 }
545 #endif
546 
547 static inline struct zone *page_zone(struct page *page)
548 {
549 	return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
550 }
551 
552 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
553 static inline unsigned long page_to_section(struct page *page)
554 {
555 	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
556 }
557 #endif
558 
559 static inline void set_page_zone(struct page *page, enum zone_type zone)
560 {
561 	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
562 	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
563 }
564 
565 static inline void set_page_node(struct page *page, unsigned long node)
566 {
567 	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
568 	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
569 }
570 
571 static inline void set_page_section(struct page *page, unsigned long section)
572 {
573 	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
574 	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
575 }
576 
577 static inline void set_page_links(struct page *page, enum zone_type zone,
578 	unsigned long node, unsigned long pfn)
579 {
580 	set_page_zone(page, zone);
581 	set_page_node(page, node);
582 	set_page_section(page, pfn_to_section_nr(pfn));
583 }
584 
585 /*
586  * Some inline functions in vmstat.h depend on page_zone()
587  */
588 #include <linux/vmstat.h>
589 
590 static __always_inline void *lowmem_page_address(struct page *page)
591 {
592 	return __va(page_to_pfn(page) << PAGE_SHIFT);
593 }
594 
595 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
596 #define HASHED_PAGE_VIRTUAL
597 #endif
598 
599 #if defined(WANT_PAGE_VIRTUAL)
600 #define page_address(page) ((page)->virtual)
601 #define set_page_address(page, address)			\
602 	do {						\
603 		(page)->virtual = (address);		\
604 	} while(0)
605 #define page_address_init()  do { } while(0)
606 #endif
607 
608 #if defined(HASHED_PAGE_VIRTUAL)
609 void *page_address(struct page *page);
610 void set_page_address(struct page *page, void *virtual);
611 void page_address_init(void);
612 #endif
613 
614 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
615 #define page_address(page) lowmem_page_address(page)
616 #define set_page_address(page, address)  do { } while(0)
617 #define page_address_init()  do { } while(0)
618 #endif
619 
620 /*
621  * On an anonymous page mapped into a user virtual memory area,
622  * page->mapping points to its anon_vma, not to a struct address_space;
623  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
624  *
625  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
626  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
627  * and then page->mapping points, not to an anon_vma, but to a private
628  * structure which KSM associates with that merged page.  See ksm.h.
629  *
630  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
631  *
632  * Please note that, confusingly, "page_mapping" refers to the inode
633  * address_space which maps the page from disk; whereas "page_mapped"
634  * refers to user virtual address space into which the page is mapped.
635  */
636 #define PAGE_MAPPING_ANON	1
637 #define PAGE_MAPPING_KSM	2
638 #define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
639 
640 extern struct address_space swapper_space;
641 static inline struct address_space *page_mapping(struct page *page)
642 {
643 	struct address_space *mapping = page->mapping;
644 
645 	VM_BUG_ON(PageSlab(page));
646 	if (unlikely(PageSwapCache(page)))
647 		mapping = &swapper_space;
648 	else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
649 		mapping = NULL;
650 	return mapping;
651 }
652 
653 /* Neutral page->mapping pointer to address_space or anon_vma or other */
654 static inline void *page_rmapping(struct page *page)
655 {
656 	return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
657 }
658 
659 static inline int PageAnon(struct page *page)
660 {
661 	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
662 }
663 
664 /*
665  * Return the pagecache index of the passed page.  Regular pagecache pages
666  * use ->index whereas swapcache pages use ->private
667  */
668 static inline pgoff_t page_index(struct page *page)
669 {
670 	if (unlikely(PageSwapCache(page)))
671 		return page_private(page);
672 	return page->index;
673 }
674 
675 /*
676  * The atomic page->_mapcount, like _count, starts from -1:
677  * so that transitions both from it and to it can be tracked,
678  * using atomic_inc_and_test and atomic_add_negative(-1).
679  */
680 static inline void reset_page_mapcount(struct page *page)
681 {
682 	atomic_set(&(page)->_mapcount, -1);
683 }
684 
685 static inline int page_mapcount(struct page *page)
686 {
687 	return atomic_read(&(page)->_mapcount) + 1;
688 }
689 
690 /*
691  * Return true if this page is mapped into pagetables.
692  */
693 static inline int page_mapped(struct page *page)
694 {
695 	return atomic_read(&(page)->_mapcount) >= 0;
696 }
697 
698 /*
699  * Different kinds of faults, as returned by handle_mm_fault().
700  * Used to decide whether a process gets delivered SIGBUS or
701  * just gets major/minor fault counters bumped up.
702  */
703 
704 #define VM_FAULT_MINOR	0 /* For backwards compat. Remove me quickly. */
705 
706 #define VM_FAULT_OOM	0x0001
707 #define VM_FAULT_SIGBUS	0x0002
708 #define VM_FAULT_MAJOR	0x0004
709 #define VM_FAULT_WRITE	0x0008	/* Special case for get_user_pages */
710 #define VM_FAULT_HWPOISON 0x0010	/* Hit poisoned page */
711 
712 #define VM_FAULT_NOPAGE	0x0100	/* ->fault installed the pte, not return page */
713 #define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
714 
715 #define VM_FAULT_ERROR	(VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
716 
717 /*
718  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
719  */
720 extern void pagefault_out_of_memory(void);
721 
722 #define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
723 
724 extern void show_free_areas(void);
725 
726 int shmem_lock(struct file *file, int lock, struct user_struct *user);
727 struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags);
728 int shmem_zero_setup(struct vm_area_struct *);
729 
730 #ifndef CONFIG_MMU
731 extern unsigned long shmem_get_unmapped_area(struct file *file,
732 					     unsigned long addr,
733 					     unsigned long len,
734 					     unsigned long pgoff,
735 					     unsigned long flags);
736 #endif
737 
738 extern int can_do_mlock(void);
739 extern int user_shm_lock(size_t, struct user_struct *);
740 extern void user_shm_unlock(size_t, struct user_struct *);
741 
742 /*
743  * Parameter block passed down to zap_pte_range in exceptional cases.
744  */
745 struct zap_details {
746 	struct vm_area_struct *nonlinear_vma;	/* Check page->index if set */
747 	struct address_space *check_mapping;	/* Check page->mapping if set */
748 	pgoff_t	first_index;			/* Lowest page->index to unmap */
749 	pgoff_t last_index;			/* Highest page->index to unmap */
750 	spinlock_t *i_mmap_lock;		/* For unmap_mapping_range: */
751 	unsigned long truncate_count;		/* Compare vm_truncate_count */
752 };
753 
754 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
755 		pte_t pte);
756 
757 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
758 		unsigned long size);
759 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
760 		unsigned long size, struct zap_details *);
761 unsigned long unmap_vmas(struct mmu_gather **tlb,
762 		struct vm_area_struct *start_vma, unsigned long start_addr,
763 		unsigned long end_addr, unsigned long *nr_accounted,
764 		struct zap_details *);
765 
766 /**
767  * mm_walk - callbacks for walk_page_range
768  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
769  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
770  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
771  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
772  * @pte_hole: if set, called for each hole at all levels
773  * @hugetlb_entry: if set, called for each hugetlb entry
774  *
775  * (see walk_page_range for more details)
776  */
777 struct mm_walk {
778 	int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
779 	int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
780 	int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
781 	int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
782 	int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
783 	int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long,
784 			     struct mm_walk *);
785 	struct mm_struct *mm;
786 	void *private;
787 };
788 
789 int walk_page_range(unsigned long addr, unsigned long end,
790 		struct mm_walk *walk);
791 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
792 		unsigned long end, unsigned long floor, unsigned long ceiling);
793 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
794 			struct vm_area_struct *vma);
795 void unmap_mapping_range(struct address_space *mapping,
796 		loff_t const holebegin, loff_t const holelen, int even_cows);
797 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
798 	unsigned long *pfn);
799 int follow_phys(struct vm_area_struct *vma, unsigned long address,
800 		unsigned int flags, unsigned long *prot, resource_size_t *phys);
801 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
802 			void *buf, int len, int write);
803 
804 static inline void unmap_shared_mapping_range(struct address_space *mapping,
805 		loff_t const holebegin, loff_t const holelen)
806 {
807 	unmap_mapping_range(mapping, holebegin, holelen, 0);
808 }
809 
810 extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
811 extern int vmtruncate(struct inode *inode, loff_t offset);
812 extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
813 
814 int truncate_inode_page(struct address_space *mapping, struct page *page);
815 int generic_error_remove_page(struct address_space *mapping, struct page *page);
816 
817 int invalidate_inode_page(struct page *page);
818 
819 #ifdef CONFIG_MMU
820 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
821 			unsigned long address, unsigned int flags);
822 #else
823 static inline int handle_mm_fault(struct mm_struct *mm,
824 			struct vm_area_struct *vma, unsigned long address,
825 			unsigned int flags)
826 {
827 	/* should never happen if there's no MMU */
828 	BUG();
829 	return VM_FAULT_SIGBUS;
830 }
831 #endif
832 
833 extern int make_pages_present(unsigned long addr, unsigned long end);
834 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
835 
836 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
837 			unsigned long start, int nr_pages, int write, int force,
838 			struct page **pages, struct vm_area_struct **vmas);
839 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
840 			struct page **pages);
841 struct page *get_dump_page(unsigned long addr);
842 
843 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
844 extern void do_invalidatepage(struct page *page, unsigned long offset);
845 
846 int __set_page_dirty_nobuffers(struct page *page);
847 int __set_page_dirty_no_writeback(struct page *page);
848 int redirty_page_for_writepage(struct writeback_control *wbc,
849 				struct page *page);
850 void account_page_dirtied(struct page *page, struct address_space *mapping);
851 int set_page_dirty(struct page *page);
852 int set_page_dirty_lock(struct page *page);
853 int clear_page_dirty_for_io(struct page *page);
854 
855 extern unsigned long move_page_tables(struct vm_area_struct *vma,
856 		unsigned long old_addr, struct vm_area_struct *new_vma,
857 		unsigned long new_addr, unsigned long len);
858 extern unsigned long do_mremap(unsigned long addr,
859 			       unsigned long old_len, unsigned long new_len,
860 			       unsigned long flags, unsigned long new_addr);
861 extern int mprotect_fixup(struct vm_area_struct *vma,
862 			  struct vm_area_struct **pprev, unsigned long start,
863 			  unsigned long end, unsigned long newflags);
864 
865 /*
866  * doesn't attempt to fault and will return short.
867  */
868 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
869 			  struct page **pages);
870 
871 /*
872  * A callback you can register to apply pressure to ageable caches.
873  *
874  * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
875  * look through the least-recently-used 'nr_to_scan' entries and
876  * attempt to free them up.  It should return the number of objects
877  * which remain in the cache.  If it returns -1, it means it cannot do
878  * any scanning at this time (eg. there is a risk of deadlock).
879  *
880  * The 'gfpmask' refers to the allocation we are currently trying to
881  * fulfil.
882  *
883  * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
884  * querying the cache size, so a fastpath for that case is appropriate.
885  */
886 struct shrinker {
887 	int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
888 	int seeks;	/* seeks to recreate an obj */
889 
890 	/* These are for internal use */
891 	struct list_head list;
892 	long nr;	/* objs pending delete */
893 };
894 #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
895 extern void register_shrinker(struct shrinker *);
896 extern void unregister_shrinker(struct shrinker *);
897 
898 int vma_wants_writenotify(struct vm_area_struct *vma);
899 
900 extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
901 
902 #ifdef __PAGETABLE_PUD_FOLDED
903 static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
904 						unsigned long address)
905 {
906 	return 0;
907 }
908 #else
909 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
910 #endif
911 
912 #ifdef __PAGETABLE_PMD_FOLDED
913 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
914 						unsigned long address)
915 {
916 	return 0;
917 }
918 #else
919 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
920 #endif
921 
922 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
923 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
924 
925 /*
926  * The following ifdef needed to get the 4level-fixup.h header to work.
927  * Remove it when 4level-fixup.h has been removed.
928  */
929 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
930 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
931 {
932 	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
933 		NULL: pud_offset(pgd, address);
934 }
935 
936 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
937 {
938 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
939 		NULL: pmd_offset(pud, address);
940 }
941 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
942 
943 #if USE_SPLIT_PTLOCKS
944 /*
945  * We tuck a spinlock to guard each pagetable page into its struct page,
946  * at page->private, with BUILD_BUG_ON to make sure that this will not
947  * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
948  * When freeing, reset page->mapping so free_pages_check won't complain.
949  */
950 #define __pte_lockptr(page)	&((page)->ptl)
951 #define pte_lock_init(_page)	do {					\
952 	spin_lock_init(__pte_lockptr(_page));				\
953 } while (0)
954 #define pte_lock_deinit(page)	((page)->mapping = NULL)
955 #define pte_lockptr(mm, pmd)	({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
956 #else	/* !USE_SPLIT_PTLOCKS */
957 /*
958  * We use mm->page_table_lock to guard all pagetable pages of the mm.
959  */
960 #define pte_lock_init(page)	do {} while (0)
961 #define pte_lock_deinit(page)	do {} while (0)
962 #define pte_lockptr(mm, pmd)	({(void)(pmd); &(mm)->page_table_lock;})
963 #endif /* USE_SPLIT_PTLOCKS */
964 
965 static inline void pgtable_page_ctor(struct page *page)
966 {
967 	pte_lock_init(page);
968 	inc_zone_page_state(page, NR_PAGETABLE);
969 }
970 
971 static inline void pgtable_page_dtor(struct page *page)
972 {
973 	pte_lock_deinit(page);
974 	dec_zone_page_state(page, NR_PAGETABLE);
975 }
976 
977 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
978 ({							\
979 	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
980 	pte_t *__pte = pte_offset_map(pmd, address);	\
981 	*(ptlp) = __ptl;				\
982 	spin_lock(__ptl);				\
983 	__pte;						\
984 })
985 
986 #define pte_unmap_unlock(pte, ptl)	do {		\
987 	spin_unlock(ptl);				\
988 	pte_unmap(pte);					\
989 } while (0)
990 
991 #define pte_alloc_map(mm, pmd, address)			\
992 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
993 		NULL: pte_offset_map(pmd, address))
994 
995 #define pte_alloc_map_lock(mm, pmd, address, ptlp)	\
996 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
997 		NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
998 
999 #define pte_alloc_kernel(pmd, address)			\
1000 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1001 		NULL: pte_offset_kernel(pmd, address))
1002 
1003 extern void free_area_init(unsigned long * zones_size);
1004 extern void free_area_init_node(int nid, unsigned long * zones_size,
1005 		unsigned long zone_start_pfn, unsigned long *zholes_size);
1006 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
1007 /*
1008  * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
1009  * zones, allocate the backing mem_map and account for memory holes in a more
1010  * architecture independent manner. This is a substitute for creating the
1011  * zone_sizes[] and zholes_size[] arrays and passing them to
1012  * free_area_init_node()
1013  *
1014  * An architecture is expected to register range of page frames backed by
1015  * physical memory with add_active_range() before calling
1016  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1017  * usage, an architecture is expected to do something like
1018  *
1019  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1020  * 							 max_highmem_pfn};
1021  * for_each_valid_physical_page_range()
1022  * 	add_active_range(node_id, start_pfn, end_pfn)
1023  * free_area_init_nodes(max_zone_pfns);
1024  *
1025  * If the architecture guarantees that there are no holes in the ranges
1026  * registered with add_active_range(), free_bootmem_active_regions()
1027  * will call free_bootmem_node() for each registered physical page range.
1028  * Similarly sparse_memory_present_with_active_regions() calls
1029  * memory_present() for each range when SPARSEMEM is enabled.
1030  *
1031  * See mm/page_alloc.c for more information on each function exposed by
1032  * CONFIG_ARCH_POPULATES_NODE_MAP
1033  */
1034 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1035 extern void add_active_range(unsigned int nid, unsigned long start_pfn,
1036 					unsigned long end_pfn);
1037 extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
1038 					unsigned long end_pfn);
1039 extern void remove_all_active_ranges(void);
1040 void sort_node_map(void);
1041 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1042 						unsigned long end_pfn);
1043 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1044 						unsigned long end_pfn);
1045 extern void get_pfn_range_for_nid(unsigned int nid,
1046 			unsigned long *start_pfn, unsigned long *end_pfn);
1047 extern unsigned long find_min_pfn_with_active_regions(void);
1048 extern void free_bootmem_with_active_regions(int nid,
1049 						unsigned long max_low_pfn);
1050 typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
1051 extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
1052 extern void sparse_memory_present_with_active_regions(int nid);
1053 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1054 
1055 #if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \
1056     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1057 static inline int __early_pfn_to_nid(unsigned long pfn)
1058 {
1059 	return 0;
1060 }
1061 #else
1062 /* please see mm/page_alloc.c */
1063 extern int __meminit early_pfn_to_nid(unsigned long pfn);
1064 #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1065 /* there is a per-arch backend function. */
1066 extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1067 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1068 #endif
1069 
1070 extern void set_dma_reserve(unsigned long new_dma_reserve);
1071 extern void memmap_init_zone(unsigned long, int, unsigned long,
1072 				unsigned long, enum memmap_context);
1073 extern void setup_per_zone_wmarks(void);
1074 extern void calculate_zone_inactive_ratio(struct zone *zone);
1075 extern void mem_init(void);
1076 extern void __init mmap_init(void);
1077 extern void show_mem(void);
1078 extern void si_meminfo(struct sysinfo * val);
1079 extern void si_meminfo_node(struct sysinfo *val, int nid);
1080 extern int after_bootmem;
1081 
1082 #ifdef CONFIG_NUMA
1083 extern void setup_per_cpu_pageset(void);
1084 #else
1085 static inline void setup_per_cpu_pageset(void) {}
1086 #endif
1087 
1088 extern void zone_pcp_update(struct zone *zone);
1089 
1090 /* nommu.c */
1091 extern atomic_long_t mmap_pages_allocated;
1092 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1093 
1094 /* prio_tree.c */
1095 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1096 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1097 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1098 struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1099 	struct prio_tree_iter *iter);
1100 
1101 #define vma_prio_tree_foreach(vma, iter, root, begin, end)	\
1102 	for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;	\
1103 		(vma = vma_prio_tree_next(vma, iter)); )
1104 
1105 static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1106 					struct list_head *list)
1107 {
1108 	vma->shared.vm_set.parent = NULL;
1109 	list_add_tail(&vma->shared.vm_set.list, list);
1110 }
1111 
1112 /* mmap.c */
1113 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1114 extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
1115 	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1116 extern struct vm_area_struct *vma_merge(struct mm_struct *,
1117 	struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1118 	unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1119 	struct mempolicy *);
1120 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1121 extern int split_vma(struct mm_struct *,
1122 	struct vm_area_struct *, unsigned long addr, int new_below);
1123 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1124 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1125 	struct rb_node **, struct rb_node *);
1126 extern void unlink_file_vma(struct vm_area_struct *);
1127 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1128 	unsigned long addr, unsigned long len, pgoff_t pgoff);
1129 extern void exit_mmap(struct mm_struct *);
1130 
1131 extern int mm_take_all_locks(struct mm_struct *mm);
1132 extern void mm_drop_all_locks(struct mm_struct *mm);
1133 
1134 #ifdef CONFIG_PROC_FS
1135 /* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1136 extern void added_exe_file_vma(struct mm_struct *mm);
1137 extern void removed_exe_file_vma(struct mm_struct *mm);
1138 #else
1139 static inline void added_exe_file_vma(struct mm_struct *mm)
1140 {}
1141 
1142 static inline void removed_exe_file_vma(struct mm_struct *mm)
1143 {}
1144 #endif /* CONFIG_PROC_FS */
1145 
1146 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1147 extern int install_special_mapping(struct mm_struct *mm,
1148 				   unsigned long addr, unsigned long len,
1149 				   unsigned long flags, struct page **pages);
1150 
1151 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1152 
1153 extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1154 	unsigned long len, unsigned long prot,
1155 	unsigned long flag, unsigned long pgoff);
1156 extern unsigned long mmap_region(struct file *file, unsigned long addr,
1157 	unsigned long len, unsigned long flags,
1158 	unsigned int vm_flags, unsigned long pgoff);
1159 
1160 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1161 	unsigned long len, unsigned long prot,
1162 	unsigned long flag, unsigned long offset)
1163 {
1164 	unsigned long ret = -EINVAL;
1165 	if ((offset + PAGE_ALIGN(len)) < offset)
1166 		goto out;
1167 	if (!(offset & ~PAGE_MASK))
1168 		ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1169 out:
1170 	return ret;
1171 }
1172 
1173 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1174 
1175 extern unsigned long do_brk(unsigned long, unsigned long);
1176 
1177 /* filemap.c */
1178 extern unsigned long page_unuse(struct page *);
1179 extern void truncate_inode_pages(struct address_space *, loff_t);
1180 extern void truncate_inode_pages_range(struct address_space *,
1181 				       loff_t lstart, loff_t lend);
1182 
1183 /* generic vm_area_ops exported for stackable file systems */
1184 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1185 
1186 /* mm/page-writeback.c */
1187 int write_one_page(struct page *page, int wait);
1188 void task_dirty_inc(struct task_struct *tsk);
1189 
1190 /* readahead.c */
1191 #define VM_MAX_READAHEAD	128	/* kbytes */
1192 #define VM_MIN_READAHEAD	16	/* kbytes (includes current page) */
1193 
1194 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1195 			pgoff_t offset, unsigned long nr_to_read);
1196 
1197 void page_cache_sync_readahead(struct address_space *mapping,
1198 			       struct file_ra_state *ra,
1199 			       struct file *filp,
1200 			       pgoff_t offset,
1201 			       unsigned long size);
1202 
1203 void page_cache_async_readahead(struct address_space *mapping,
1204 				struct file_ra_state *ra,
1205 				struct file *filp,
1206 				struct page *pg,
1207 				pgoff_t offset,
1208 				unsigned long size);
1209 
1210 unsigned long max_sane_readahead(unsigned long nr);
1211 unsigned long ra_submit(struct file_ra_state *ra,
1212 			struct address_space *mapping,
1213 			struct file *filp);
1214 
1215 /* Do stack extension */
1216 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1217 #ifdef CONFIG_IA64
1218 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1219 #endif
1220 extern int expand_stack_downwards(struct vm_area_struct *vma,
1221 				  unsigned long address);
1222 
1223 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1224 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1225 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1226 					     struct vm_area_struct **pprev);
1227 
1228 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1229    NULL if none.  Assume start_addr < end_addr. */
1230 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1231 {
1232 	struct vm_area_struct * vma = find_vma(mm,start_addr);
1233 
1234 	if (vma && end_addr <= vma->vm_start)
1235 		vma = NULL;
1236 	return vma;
1237 }
1238 
1239 static inline unsigned long vma_pages(struct vm_area_struct *vma)
1240 {
1241 	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1242 }
1243 
1244 pgprot_t vm_get_page_prot(unsigned long vm_flags);
1245 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1246 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1247 			unsigned long pfn, unsigned long size, pgprot_t);
1248 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1249 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1250 			unsigned long pfn);
1251 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1252 			unsigned long pfn);
1253 
1254 struct page *follow_page(struct vm_area_struct *, unsigned long address,
1255 			unsigned int foll_flags);
1256 #define FOLL_WRITE	0x01	/* check pte is writable */
1257 #define FOLL_TOUCH	0x02	/* mark page accessed */
1258 #define FOLL_GET	0x04	/* do get_page on page */
1259 #define FOLL_DUMP	0x08	/* give error on hole if it would be zero */
1260 #define FOLL_FORCE	0x10	/* get_user_pages read/write w/o permission */
1261 
1262 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1263 			void *data);
1264 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1265 			       unsigned long size, pte_fn_t fn, void *data);
1266 
1267 #ifdef CONFIG_PROC_FS
1268 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1269 #else
1270 static inline void vm_stat_account(struct mm_struct *mm,
1271 			unsigned long flags, struct file *file, long pages)
1272 {
1273 }
1274 #endif /* CONFIG_PROC_FS */
1275 
1276 #ifdef CONFIG_DEBUG_PAGEALLOC
1277 extern int debug_pagealloc_enabled;
1278 
1279 extern void kernel_map_pages(struct page *page, int numpages, int enable);
1280 
1281 static inline void enable_debug_pagealloc(void)
1282 {
1283 	debug_pagealloc_enabled = 1;
1284 }
1285 #ifdef CONFIG_HIBERNATION
1286 extern bool kernel_page_present(struct page *page);
1287 #endif /* CONFIG_HIBERNATION */
1288 #else
1289 static inline void
1290 kernel_map_pages(struct page *page, int numpages, int enable) {}
1291 static inline void enable_debug_pagealloc(void)
1292 {
1293 }
1294 #ifdef CONFIG_HIBERNATION
1295 static inline bool kernel_page_present(struct page *page) { return true; }
1296 #endif /* CONFIG_HIBERNATION */
1297 #endif
1298 
1299 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1300 #ifdef	__HAVE_ARCH_GATE_AREA
1301 int in_gate_area_no_task(unsigned long addr);
1302 int in_gate_area(struct task_struct *task, unsigned long addr);
1303 #else
1304 int in_gate_area_no_task(unsigned long addr);
1305 #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1306 #endif	/* __HAVE_ARCH_GATE_AREA */
1307 
1308 int drop_caches_sysctl_handler(struct ctl_table *, int,
1309 					void __user *, size_t *, loff_t *);
1310 unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1311 			unsigned long lru_pages);
1312 
1313 #ifndef CONFIG_MMU
1314 #define randomize_va_space 0
1315 #else
1316 extern int randomize_va_space;
1317 #endif
1318 
1319 const char * arch_vma_name(struct vm_area_struct *vma);
1320 void print_vma_addr(char *prefix, unsigned long rip);
1321 
1322 struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1323 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1324 pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1325 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1326 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1327 void *vmemmap_alloc_block(unsigned long size, int node);
1328 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1329 int vmemmap_populate_basepages(struct page *start_page,
1330 						unsigned long pages, int node);
1331 int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1332 void vmemmap_populate_print_last(void);
1333 
1334 extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
1335 				 size_t size);
1336 extern void refund_locked_memory(struct mm_struct *mm, size_t size);
1337 
1338 enum mf_flags {
1339 	MF_COUNT_INCREASED = 1 << 0,
1340 };
1341 extern void memory_failure(unsigned long pfn, int trapno);
1342 extern int __memory_failure(unsigned long pfn, int trapno, int flags);
1343 extern int unpoison_memory(unsigned long pfn);
1344 extern int sysctl_memory_failure_early_kill;
1345 extern int sysctl_memory_failure_recovery;
1346 extern void shake_page(struct page *p, int access);
1347 extern atomic_long_t mce_bad_pages;
1348 extern int soft_offline_page(struct page *page, int flags);
1349 
1350 #endif /* __KERNEL__ */
1351 #endif /* _LINUX_MM_H */
1352