xref: /linux-6.15/include/linux/mm.h (revision a115bc07)
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 #include <linux/range.h>
16 
17 struct mempolicy;
18 struct anon_vma;
19 struct file_ra_state;
20 struct user_struct;
21 struct writeback_control;
22 struct rlimit;
23 
24 #ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
25 extern unsigned long max_mapnr;
26 #endif
27 
28 extern unsigned long num_physpages;
29 extern unsigned long totalram_pages;
30 extern void * high_memory;
31 extern int page_cluster;
32 
33 #ifdef CONFIG_SYSCTL
34 extern int sysctl_legacy_va_layout;
35 #else
36 #define sysctl_legacy_va_layout 0
37 #endif
38 
39 #include <asm/page.h>
40 #include <asm/pgtable.h>
41 #include <asm/processor.h>
42 
43 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
44 
45 /* to align the pointer to the (next) page boundary */
46 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
47 
48 /*
49  * Linux kernel virtual memory manager primitives.
50  * The idea being to have a "virtual" mm in the same way
51  * we have a virtual fs - giving a cleaner interface to the
52  * mm details, and allowing different kinds of memory mappings
53  * (from shared memory to executable loading to arbitrary
54  * mmap() functions).
55  */
56 
57 extern struct kmem_cache *vm_area_cachep;
58 
59 #ifndef CONFIG_MMU
60 extern struct rb_root nommu_region_tree;
61 extern struct rw_semaphore nommu_region_sem;
62 
63 extern unsigned int kobjsize(const void *objp);
64 #endif
65 
66 /*
67  * vm_flags in vm_area_struct, see mm_types.h.
68  */
69 #define VM_READ		0x00000001	/* currently active flags */
70 #define VM_WRITE	0x00000002
71 #define VM_EXEC		0x00000004
72 #define VM_SHARED	0x00000008
73 
74 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
75 #define VM_MAYREAD	0x00000010	/* limits for mprotect() etc */
76 #define VM_MAYWRITE	0x00000020
77 #define VM_MAYEXEC	0x00000040
78 #define VM_MAYSHARE	0x00000080
79 
80 #define VM_GROWSDOWN	0x00000100	/* general info on the segment */
81 #define VM_GROWSUP	0x00000200
82 #define VM_PFNMAP	0x00000400	/* Page-ranges managed without "struct page", just pure PFN */
83 #define VM_DENYWRITE	0x00000800	/* ETXTBSY on write attempts.. */
84 
85 #define VM_EXECUTABLE	0x00001000
86 #define VM_LOCKED	0x00002000
87 #define VM_IO           0x00004000	/* Memory mapped I/O or similar */
88 
89 					/* Used by sys_madvise() */
90 #define VM_SEQ_READ	0x00008000	/* App will access data sequentially */
91 #define VM_RAND_READ	0x00010000	/* App will not benefit from clustered reads */
92 
93 #define VM_DONTCOPY	0x00020000      /* Do not copy this vma on fork */
94 #define VM_DONTEXPAND	0x00040000	/* Cannot expand with mremap() */
95 #define VM_RESERVED	0x00080000	/* Count as reserved_vm like IO */
96 #define VM_ACCOUNT	0x00100000	/* Is a VM accounted object */
97 #define VM_NORESERVE	0x00200000	/* should the VM suppress accounting */
98 #define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */
99 #define VM_NONLINEAR	0x00800000	/* Is non-linear (remap_file_pages) */
100 #define VM_MAPPED_COPY	0x01000000	/* T if mapped copy of data (nommu mmap) */
101 #define VM_INSERTPAGE	0x02000000	/* The vma has had "vm_insert_page()" done on it */
102 #define VM_ALWAYSDUMP	0x04000000	/* Always include in core dumps */
103 
104 #define VM_CAN_NONLINEAR 0x08000000	/* Has ->fault & does nonlinear pages */
105 #define VM_MIXEDMAP	0x10000000	/* Can contain "struct page" and pure PFN pages */
106 #define VM_SAO		0x20000000	/* Strong Access Ordering (powerpc) */
107 #define VM_PFN_AT_MMAP	0x40000000	/* PFNMAP vma that is fully mapped at mmap time */
108 #define VM_MERGEABLE	0x80000000	/* KSM may merge identical pages */
109 
110 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
111 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
112 #endif
113 
114 #ifdef CONFIG_STACK_GROWSUP
115 #define VM_STACK_FLAGS	(VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
116 #else
117 #define VM_STACK_FLAGS	(VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
118 #endif
119 
120 #define VM_READHINTMASK			(VM_SEQ_READ | VM_RAND_READ)
121 #define VM_ClearReadHint(v)		(v)->vm_flags &= ~VM_READHINTMASK
122 #define VM_NormalReadHint(v)		(!((v)->vm_flags & VM_READHINTMASK))
123 #define VM_SequentialReadHint(v)	((v)->vm_flags & VM_SEQ_READ)
124 #define VM_RandomReadHint(v)		((v)->vm_flags & VM_RAND_READ)
125 
126 /*
127  * special vmas that are non-mergable, non-mlock()able
128  */
129 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
130 
131 /*
132  * mapping from the currently active vm_flags protection bits (the
133  * low four bits) to a page protection mask..
134  */
135 extern pgprot_t protection_map[16];
136 
137 #define FAULT_FLAG_WRITE	0x01	/* Fault was a write access */
138 #define FAULT_FLAG_NONLINEAR	0x02	/* Fault was via a nonlinear mapping */
139 #define FAULT_FLAG_MKWRITE	0x04	/* Fault was mkwrite of existing pte */
140 
141 /*
142  * This interface is used by x86 PAT code to identify a pfn mapping that is
143  * linear over entire vma. This is to optimize PAT code that deals with
144  * marking the physical region with a particular prot. This is not for generic
145  * mm use. Note also that this check will not work if the pfn mapping is
146  * linear for a vma starting at physical address 0. In which case PAT code
147  * falls back to slow path of reserving physical range page by page.
148  */
149 static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
150 {
151 	return (vma->vm_flags & VM_PFN_AT_MMAP);
152 }
153 
154 static inline int is_pfn_mapping(struct vm_area_struct *vma)
155 {
156 	return (vma->vm_flags & VM_PFNMAP);
157 }
158 
159 /*
160  * vm_fault is filled by the the pagefault handler and passed to the vma's
161  * ->fault function. The vma's ->fault is responsible for returning a bitmask
162  * of VM_FAULT_xxx flags that give details about how the fault was handled.
163  *
164  * pgoff should be used in favour of virtual_address, if possible. If pgoff
165  * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
166  * mapping support.
167  */
168 struct vm_fault {
169 	unsigned int flags;		/* FAULT_FLAG_xxx flags */
170 	pgoff_t pgoff;			/* Logical page offset based on vma */
171 	void __user *virtual_address;	/* Faulting virtual address */
172 
173 	struct page *page;		/* ->fault handlers should return a
174 					 * page here, unless VM_FAULT_NOPAGE
175 					 * is set (which is also implied by
176 					 * VM_FAULT_ERROR).
177 					 */
178 };
179 
180 /*
181  * These are the virtual MM functions - opening of an area, closing and
182  * unmapping it (needed to keep files on disk up-to-date etc), pointer
183  * to the functions called when a no-page or a wp-page exception occurs.
184  */
185 struct vm_operations_struct {
186 	void (*open)(struct vm_area_struct * area);
187 	void (*close)(struct vm_area_struct * area);
188 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
189 
190 	/* notification that a previously read-only page is about to become
191 	 * writable, if an error is returned it will cause a SIGBUS */
192 	int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
193 
194 	/* called by access_process_vm when get_user_pages() fails, typically
195 	 * for use by special VMAs that can switch between memory and hardware
196 	 */
197 	int (*access)(struct vm_area_struct *vma, unsigned long addr,
198 		      void *buf, int len, int write);
199 #ifdef CONFIG_NUMA
200 	/*
201 	 * set_policy() op must add a reference to any non-NULL @new mempolicy
202 	 * to hold the policy upon return.  Caller should pass NULL @new to
203 	 * remove a policy and fall back to surrounding context--i.e. do not
204 	 * install a MPOL_DEFAULT policy, nor the task or system default
205 	 * mempolicy.
206 	 */
207 	int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
208 
209 	/*
210 	 * get_policy() op must add reference [mpol_get()] to any policy at
211 	 * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
212 	 * in mm/mempolicy.c will do this automatically.
213 	 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
214 	 * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
215 	 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
216 	 * must return NULL--i.e., do not "fallback" to task or system default
217 	 * policy.
218 	 */
219 	struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
220 					unsigned long addr);
221 	int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
222 		const nodemask_t *to, unsigned long flags);
223 #endif
224 };
225 
226 struct mmu_gather;
227 struct inode;
228 
229 #define page_private(page)		((page)->private)
230 #define set_page_private(page, v)	((page)->private = (v))
231 
232 /*
233  * FIXME: take this include out, include page-flags.h in
234  * files which need it (119 of them)
235  */
236 #include <linux/page-flags.h>
237 
238 /*
239  * Methods to modify the page usage count.
240  *
241  * What counts for a page usage:
242  * - cache mapping   (page->mapping)
243  * - private data    (page->private)
244  * - page mapped in a task's page tables, each mapping
245  *   is counted separately
246  *
247  * Also, many kernel routines increase the page count before a critical
248  * routine so they can be sure the page doesn't go away from under them.
249  */
250 
251 /*
252  * Drop a ref, return true if the refcount fell to zero (the page has no users)
253  */
254 static inline int put_page_testzero(struct page *page)
255 {
256 	VM_BUG_ON(atomic_read(&page->_count) == 0);
257 	return atomic_dec_and_test(&page->_count);
258 }
259 
260 /*
261  * Try to grab a ref unless the page has a refcount of zero, return false if
262  * that is the case.
263  */
264 static inline int get_page_unless_zero(struct page *page)
265 {
266 	return atomic_inc_not_zero(&page->_count);
267 }
268 
269 extern int page_is_ram(unsigned long pfn);
270 
271 /* Support for virtually mapped pages */
272 struct page *vmalloc_to_page(const void *addr);
273 unsigned long vmalloc_to_pfn(const void *addr);
274 
275 /*
276  * Determine if an address is within the vmalloc range
277  *
278  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
279  * is no special casing required.
280  */
281 static inline int is_vmalloc_addr(const void *x)
282 {
283 #ifdef CONFIG_MMU
284 	unsigned long addr = (unsigned long)x;
285 
286 	return addr >= VMALLOC_START && addr < VMALLOC_END;
287 #else
288 	return 0;
289 #endif
290 }
291 #ifdef CONFIG_MMU
292 extern int is_vmalloc_or_module_addr(const void *x);
293 #else
294 static inline int is_vmalloc_or_module_addr(const void *x)
295 {
296 	return 0;
297 }
298 #endif
299 
300 static inline struct page *compound_head(struct page *page)
301 {
302 	if (unlikely(PageTail(page)))
303 		return page->first_page;
304 	return page;
305 }
306 
307 static inline int page_count(struct page *page)
308 {
309 	return atomic_read(&compound_head(page)->_count);
310 }
311 
312 static inline void get_page(struct page *page)
313 {
314 	page = compound_head(page);
315 	VM_BUG_ON(atomic_read(&page->_count) == 0);
316 	atomic_inc(&page->_count);
317 }
318 
319 static inline struct page *virt_to_head_page(const void *x)
320 {
321 	struct page *page = virt_to_page(x);
322 	return compound_head(page);
323 }
324 
325 /*
326  * Setup the page count before being freed into the page allocator for
327  * the first time (boot or memory hotplug)
328  */
329 static inline void init_page_count(struct page *page)
330 {
331 	atomic_set(&page->_count, 1);
332 }
333 
334 void put_page(struct page *page);
335 void put_pages_list(struct list_head *pages);
336 
337 void split_page(struct page *page, unsigned int order);
338 
339 /*
340  * Compound pages have a destructor function.  Provide a
341  * prototype for that function and accessor functions.
342  * These are _only_ valid on the head of a PG_compound page.
343  */
344 typedef void compound_page_dtor(struct page *);
345 
346 static inline void set_compound_page_dtor(struct page *page,
347 						compound_page_dtor *dtor)
348 {
349 	page[1].lru.next = (void *)dtor;
350 }
351 
352 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
353 {
354 	return (compound_page_dtor *)page[1].lru.next;
355 }
356 
357 static inline int compound_order(struct page *page)
358 {
359 	if (!PageHead(page))
360 		return 0;
361 	return (unsigned long)page[1].lru.prev;
362 }
363 
364 static inline void set_compound_order(struct page *page, unsigned long order)
365 {
366 	page[1].lru.prev = (void *)order;
367 }
368 
369 /*
370  * Multiple processes may "see" the same page. E.g. for untouched
371  * mappings of /dev/null, all processes see the same page full of
372  * zeroes, and text pages of executables and shared libraries have
373  * only one copy in memory, at most, normally.
374  *
375  * For the non-reserved pages, page_count(page) denotes a reference count.
376  *   page_count() == 0 means the page is free. page->lru is then used for
377  *   freelist management in the buddy allocator.
378  *   page_count() > 0  means the page has been allocated.
379  *
380  * Pages are allocated by the slab allocator in order to provide memory
381  * to kmalloc and kmem_cache_alloc. In this case, the management of the
382  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
383  * unless a particular usage is carefully commented. (the responsibility of
384  * freeing the kmalloc memory is the caller's, of course).
385  *
386  * A page may be used by anyone else who does a __get_free_page().
387  * In this case, page_count still tracks the references, and should only
388  * be used through the normal accessor functions. The top bits of page->flags
389  * and page->virtual store page management information, but all other fields
390  * are unused and could be used privately, carefully. The management of this
391  * page is the responsibility of the one who allocated it, and those who have
392  * subsequently been given references to it.
393  *
394  * The other pages (we may call them "pagecache pages") are completely
395  * managed by the Linux memory manager: I/O, buffers, swapping etc.
396  * The following discussion applies only to them.
397  *
398  * A pagecache page contains an opaque `private' member, which belongs to the
399  * page's address_space. Usually, this is the address of a circular list of
400  * the page's disk buffers. PG_private must be set to tell the VM to call
401  * into the filesystem to release these pages.
402  *
403  * A page may belong to an inode's memory mapping. In this case, page->mapping
404  * is the pointer to the inode, and page->index is the file offset of the page,
405  * in units of PAGE_CACHE_SIZE.
406  *
407  * If pagecache pages are not associated with an inode, they are said to be
408  * anonymous pages. These may become associated with the swapcache, and in that
409  * case PG_swapcache is set, and page->private is an offset into the swapcache.
410  *
411  * In either case (swapcache or inode backed), the pagecache itself holds one
412  * reference to the page. Setting PG_private should also increment the
413  * refcount. The each user mapping also has a reference to the page.
414  *
415  * The pagecache pages are stored in a per-mapping radix tree, which is
416  * rooted at mapping->page_tree, and indexed by offset.
417  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
418  * lists, we instead now tag pages as dirty/writeback in the radix tree.
419  *
420  * All pagecache pages may be subject to I/O:
421  * - inode pages may need to be read from disk,
422  * - inode pages which have been modified and are MAP_SHARED may need
423  *   to be written back to the inode on disk,
424  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
425  *   modified may need to be swapped out to swap space and (later) to be read
426  *   back into memory.
427  */
428 
429 /*
430  * The zone field is never updated after free_area_init_core()
431  * sets it, so none of the operations on it need to be atomic.
432  */
433 
434 
435 /*
436  * page->flags layout:
437  *
438  * There are three possibilities for how page->flags get
439  * laid out.  The first is for the normal case, without
440  * sparsemem.  The second is for sparsemem when there is
441  * plenty of space for node and section.  The last is when
442  * we have run out of space and have to fall back to an
443  * alternate (slower) way of determining the node.
444  *
445  * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
446  * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
447  * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
448  */
449 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
450 #define SECTIONS_WIDTH		SECTIONS_SHIFT
451 #else
452 #define SECTIONS_WIDTH		0
453 #endif
454 
455 #define ZONES_WIDTH		ZONES_SHIFT
456 
457 #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
458 #define NODES_WIDTH		NODES_SHIFT
459 #else
460 #ifdef CONFIG_SPARSEMEM_VMEMMAP
461 #error "Vmemmap: No space for nodes field in page flags"
462 #endif
463 #define NODES_WIDTH		0
464 #endif
465 
466 /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
467 #define SECTIONS_PGOFF		((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
468 #define NODES_PGOFF		(SECTIONS_PGOFF - NODES_WIDTH)
469 #define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
470 
471 /*
472  * We are going to use the flags for the page to node mapping if its in
473  * there.  This includes the case where there is no node, so it is implicit.
474  */
475 #if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
476 #define NODE_NOT_IN_PAGE_FLAGS
477 #endif
478 
479 #ifndef PFN_SECTION_SHIFT
480 #define PFN_SECTION_SHIFT 0
481 #endif
482 
483 /*
484  * Define the bit shifts to access each section.  For non-existant
485  * sections we define the shift as 0; that plus a 0 mask ensures
486  * the compiler will optimise away reference to them.
487  */
488 #define SECTIONS_PGSHIFT	(SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
489 #define NODES_PGSHIFT		(NODES_PGOFF * (NODES_WIDTH != 0))
490 #define ZONES_PGSHIFT		(ZONES_PGOFF * (ZONES_WIDTH != 0))
491 
492 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
493 #ifdef NODE_NOT_IN_PAGEFLAGS
494 #define ZONEID_SHIFT		(SECTIONS_SHIFT + ZONES_SHIFT)
495 #define ZONEID_PGOFF		((SECTIONS_PGOFF < ZONES_PGOFF)? \
496 						SECTIONS_PGOFF : ZONES_PGOFF)
497 #else
498 #define ZONEID_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
499 #define ZONEID_PGOFF		((NODES_PGOFF < ZONES_PGOFF)? \
500 						NODES_PGOFF : ZONES_PGOFF)
501 #endif
502 
503 #define ZONEID_PGSHIFT		(ZONEID_PGOFF * (ZONEID_SHIFT != 0))
504 
505 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
506 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
507 #endif
508 
509 #define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
510 #define NODES_MASK		((1UL << NODES_WIDTH) - 1)
511 #define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
512 #define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
513 
514 static inline enum zone_type page_zonenum(struct page *page)
515 {
516 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
517 }
518 
519 /*
520  * The identification function is only used by the buddy allocator for
521  * determining if two pages could be buddies. We are not really
522  * identifying a zone since we could be using a the section number
523  * id if we have not node id available in page flags.
524  * We guarantee only that it will return the same value for two
525  * combinable pages in a zone.
526  */
527 static inline int page_zone_id(struct page *page)
528 {
529 	return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
530 }
531 
532 static inline int zone_to_nid(struct zone *zone)
533 {
534 #ifdef CONFIG_NUMA
535 	return zone->node;
536 #else
537 	return 0;
538 #endif
539 }
540 
541 #ifdef NODE_NOT_IN_PAGE_FLAGS
542 extern int page_to_nid(struct page *page);
543 #else
544 static inline int page_to_nid(struct page *page)
545 {
546 	return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
547 }
548 #endif
549 
550 static inline struct zone *page_zone(struct page *page)
551 {
552 	return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
553 }
554 
555 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
556 static inline unsigned long page_to_section(struct page *page)
557 {
558 	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
559 }
560 #endif
561 
562 static inline void set_page_zone(struct page *page, enum zone_type zone)
563 {
564 	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
565 	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
566 }
567 
568 static inline void set_page_node(struct page *page, unsigned long node)
569 {
570 	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
571 	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
572 }
573 
574 static inline void set_page_section(struct page *page, unsigned long section)
575 {
576 	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
577 	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
578 }
579 
580 static inline void set_page_links(struct page *page, enum zone_type zone,
581 	unsigned long node, unsigned long pfn)
582 {
583 	set_page_zone(page, zone);
584 	set_page_node(page, node);
585 	set_page_section(page, pfn_to_section_nr(pfn));
586 }
587 
588 /*
589  * Some inline functions in vmstat.h depend on page_zone()
590  */
591 #include <linux/vmstat.h>
592 
593 static __always_inline void *lowmem_page_address(struct page *page)
594 {
595 	return __va(page_to_pfn(page) << PAGE_SHIFT);
596 }
597 
598 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
599 #define HASHED_PAGE_VIRTUAL
600 #endif
601 
602 #if defined(WANT_PAGE_VIRTUAL)
603 #define page_address(page) ((page)->virtual)
604 #define set_page_address(page, address)			\
605 	do {						\
606 		(page)->virtual = (address);		\
607 	} while(0)
608 #define page_address_init()  do { } while(0)
609 #endif
610 
611 #if defined(HASHED_PAGE_VIRTUAL)
612 void *page_address(struct page *page);
613 void set_page_address(struct page *page, void *virtual);
614 void page_address_init(void);
615 #endif
616 
617 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
618 #define page_address(page) lowmem_page_address(page)
619 #define set_page_address(page, address)  do { } while(0)
620 #define page_address_init()  do { } while(0)
621 #endif
622 
623 /*
624  * On an anonymous page mapped into a user virtual memory area,
625  * page->mapping points to its anon_vma, not to a struct address_space;
626  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
627  *
628  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
629  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
630  * and then page->mapping points, not to an anon_vma, but to a private
631  * structure which KSM associates with that merged page.  See ksm.h.
632  *
633  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
634  *
635  * Please note that, confusingly, "page_mapping" refers to the inode
636  * address_space which maps the page from disk; whereas "page_mapped"
637  * refers to user virtual address space into which the page is mapped.
638  */
639 #define PAGE_MAPPING_ANON	1
640 #define PAGE_MAPPING_KSM	2
641 #define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
642 
643 extern struct address_space swapper_space;
644 static inline struct address_space *page_mapping(struct page *page)
645 {
646 	struct address_space *mapping = page->mapping;
647 
648 	VM_BUG_ON(PageSlab(page));
649 	if (unlikely(PageSwapCache(page)))
650 		mapping = &swapper_space;
651 	else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
652 		mapping = NULL;
653 	return mapping;
654 }
655 
656 /* Neutral page->mapping pointer to address_space or anon_vma or other */
657 static inline void *page_rmapping(struct page *page)
658 {
659 	return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
660 }
661 
662 static inline int PageAnon(struct page *page)
663 {
664 	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
665 }
666 
667 /*
668  * Return the pagecache index of the passed page.  Regular pagecache pages
669  * use ->index whereas swapcache pages use ->private
670  */
671 static inline pgoff_t page_index(struct page *page)
672 {
673 	if (unlikely(PageSwapCache(page)))
674 		return page_private(page);
675 	return page->index;
676 }
677 
678 /*
679  * The atomic page->_mapcount, like _count, starts from -1:
680  * so that transitions both from it and to it can be tracked,
681  * using atomic_inc_and_test and atomic_add_negative(-1).
682  */
683 static inline void reset_page_mapcount(struct page *page)
684 {
685 	atomic_set(&(page)->_mapcount, -1);
686 }
687 
688 static inline int page_mapcount(struct page *page)
689 {
690 	return atomic_read(&(page)->_mapcount) + 1;
691 }
692 
693 /*
694  * Return true if this page is mapped into pagetables.
695  */
696 static inline int page_mapped(struct page *page)
697 {
698 	return atomic_read(&(page)->_mapcount) >= 0;
699 }
700 
701 /*
702  * Different kinds of faults, as returned by handle_mm_fault().
703  * Used to decide whether a process gets delivered SIGBUS or
704  * just gets major/minor fault counters bumped up.
705  */
706 
707 #define VM_FAULT_MINOR	0 /* For backwards compat. Remove me quickly. */
708 
709 #define VM_FAULT_OOM	0x0001
710 #define VM_FAULT_SIGBUS	0x0002
711 #define VM_FAULT_MAJOR	0x0004
712 #define VM_FAULT_WRITE	0x0008	/* Special case for get_user_pages */
713 #define VM_FAULT_HWPOISON 0x0010	/* Hit poisoned page */
714 
715 #define VM_FAULT_NOPAGE	0x0100	/* ->fault installed the pte, not return page */
716 #define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
717 
718 #define VM_FAULT_ERROR	(VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
719 
720 /*
721  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
722  */
723 extern void pagefault_out_of_memory(void);
724 
725 #define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
726 
727 extern void show_free_areas(void);
728 
729 int shmem_lock(struct file *file, int lock, struct user_struct *user);
730 struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags);
731 int shmem_zero_setup(struct vm_area_struct *);
732 
733 #ifndef CONFIG_MMU
734 extern unsigned long shmem_get_unmapped_area(struct file *file,
735 					     unsigned long addr,
736 					     unsigned long len,
737 					     unsigned long pgoff,
738 					     unsigned long flags);
739 #endif
740 
741 extern int can_do_mlock(void);
742 extern int user_shm_lock(size_t, struct user_struct *);
743 extern void user_shm_unlock(size_t, struct user_struct *);
744 
745 /*
746  * Parameter block passed down to zap_pte_range in exceptional cases.
747  */
748 struct zap_details {
749 	struct vm_area_struct *nonlinear_vma;	/* Check page->index if set */
750 	struct address_space *check_mapping;	/* Check page->mapping if set */
751 	pgoff_t	first_index;			/* Lowest page->index to unmap */
752 	pgoff_t last_index;			/* Highest page->index to unmap */
753 	spinlock_t *i_mmap_lock;		/* For unmap_mapping_range: */
754 	unsigned long truncate_count;		/* Compare vm_truncate_count */
755 };
756 
757 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
758 		pte_t pte);
759 
760 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
761 		unsigned long size);
762 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
763 		unsigned long size, struct zap_details *);
764 unsigned long unmap_vmas(struct mmu_gather **tlb,
765 		struct vm_area_struct *start_vma, unsigned long start_addr,
766 		unsigned long end_addr, unsigned long *nr_accounted,
767 		struct zap_details *);
768 
769 /**
770  * mm_walk - callbacks for walk_page_range
771  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
772  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
773  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
774  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
775  * @pte_hole: if set, called for each hole at all levels
776  * @hugetlb_entry: if set, called for each hugetlb entry
777  *
778  * (see walk_page_range for more details)
779  */
780 struct mm_walk {
781 	int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
782 	int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
783 	int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
784 	int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
785 	int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
786 	int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long,
787 			     struct mm_walk *);
788 	struct mm_struct *mm;
789 	void *private;
790 };
791 
792 int walk_page_range(unsigned long addr, unsigned long end,
793 		struct mm_walk *walk);
794 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
795 		unsigned long end, unsigned long floor, unsigned long ceiling);
796 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
797 			struct vm_area_struct *vma);
798 void unmap_mapping_range(struct address_space *mapping,
799 		loff_t const holebegin, loff_t const holelen, int even_cows);
800 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
801 	unsigned long *pfn);
802 int follow_phys(struct vm_area_struct *vma, unsigned long address,
803 		unsigned int flags, unsigned long *prot, resource_size_t *phys);
804 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
805 			void *buf, int len, int write);
806 
807 static inline void unmap_shared_mapping_range(struct address_space *mapping,
808 		loff_t const holebegin, loff_t const holelen)
809 {
810 	unmap_mapping_range(mapping, holebegin, holelen, 0);
811 }
812 
813 extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
814 extern int vmtruncate(struct inode *inode, loff_t offset);
815 extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
816 
817 int truncate_inode_page(struct address_space *mapping, struct page *page);
818 int generic_error_remove_page(struct address_space *mapping, struct page *page);
819 
820 int invalidate_inode_page(struct page *page);
821 
822 #ifdef CONFIG_MMU
823 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
824 			unsigned long address, unsigned int flags);
825 #else
826 static inline int handle_mm_fault(struct mm_struct *mm,
827 			struct vm_area_struct *vma, unsigned long address,
828 			unsigned int flags)
829 {
830 	/* should never happen if there's no MMU */
831 	BUG();
832 	return VM_FAULT_SIGBUS;
833 }
834 #endif
835 
836 extern int make_pages_present(unsigned long addr, unsigned long end);
837 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
838 
839 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
840 			unsigned long start, int nr_pages, int write, int force,
841 			struct page **pages, struct vm_area_struct **vmas);
842 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
843 			struct page **pages);
844 struct page *get_dump_page(unsigned long addr);
845 
846 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
847 extern void do_invalidatepage(struct page *page, unsigned long offset);
848 
849 int __set_page_dirty_nobuffers(struct page *page);
850 int __set_page_dirty_no_writeback(struct page *page);
851 int redirty_page_for_writepage(struct writeback_control *wbc,
852 				struct page *page);
853 void account_page_dirtied(struct page *page, struct address_space *mapping);
854 int set_page_dirty(struct page *page);
855 int set_page_dirty_lock(struct page *page);
856 int clear_page_dirty_for_io(struct page *page);
857 
858 extern unsigned long move_page_tables(struct vm_area_struct *vma,
859 		unsigned long old_addr, struct vm_area_struct *new_vma,
860 		unsigned long new_addr, unsigned long len);
861 extern unsigned long do_mremap(unsigned long addr,
862 			       unsigned long old_len, unsigned long new_len,
863 			       unsigned long flags, unsigned long new_addr);
864 extern int mprotect_fixup(struct vm_area_struct *vma,
865 			  struct vm_area_struct **pprev, unsigned long start,
866 			  unsigned long end, unsigned long newflags);
867 
868 /*
869  * doesn't attempt to fault and will return short.
870  */
871 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
872 			  struct page **pages);
873 /*
874  * per-process(per-mm_struct) statistics.
875  */
876 #if defined(SPLIT_RSS_COUNTING)
877 /*
878  * The mm counters are not protected by its page_table_lock,
879  * so must be incremented atomically.
880  */
881 static inline void set_mm_counter(struct mm_struct *mm, int member, long value)
882 {
883 	atomic_long_set(&mm->rss_stat.count[member], value);
884 }
885 
886 unsigned long get_mm_counter(struct mm_struct *mm, int member);
887 
888 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
889 {
890 	atomic_long_add(value, &mm->rss_stat.count[member]);
891 }
892 
893 static inline void inc_mm_counter(struct mm_struct *mm, int member)
894 {
895 	atomic_long_inc(&mm->rss_stat.count[member]);
896 }
897 
898 static inline void dec_mm_counter(struct mm_struct *mm, int member)
899 {
900 	atomic_long_dec(&mm->rss_stat.count[member]);
901 }
902 
903 #else  /* !USE_SPLIT_PTLOCKS */
904 /*
905  * The mm counters are protected by its page_table_lock,
906  * so can be incremented directly.
907  */
908 static inline void set_mm_counter(struct mm_struct *mm, int member, long value)
909 {
910 	mm->rss_stat.count[member] = value;
911 }
912 
913 static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
914 {
915 	return mm->rss_stat.count[member];
916 }
917 
918 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
919 {
920 	mm->rss_stat.count[member] += value;
921 }
922 
923 static inline void inc_mm_counter(struct mm_struct *mm, int member)
924 {
925 	mm->rss_stat.count[member]++;
926 }
927 
928 static inline void dec_mm_counter(struct mm_struct *mm, int member)
929 {
930 	mm->rss_stat.count[member]--;
931 }
932 
933 #endif /* !USE_SPLIT_PTLOCKS */
934 
935 static inline unsigned long get_mm_rss(struct mm_struct *mm)
936 {
937 	return get_mm_counter(mm, MM_FILEPAGES) +
938 		get_mm_counter(mm, MM_ANONPAGES);
939 }
940 
941 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
942 {
943 	return max(mm->hiwater_rss, get_mm_rss(mm));
944 }
945 
946 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
947 {
948 	return max(mm->hiwater_vm, mm->total_vm);
949 }
950 
951 static inline void update_hiwater_rss(struct mm_struct *mm)
952 {
953 	unsigned long _rss = get_mm_rss(mm);
954 
955 	if ((mm)->hiwater_rss < _rss)
956 		(mm)->hiwater_rss = _rss;
957 }
958 
959 static inline void update_hiwater_vm(struct mm_struct *mm)
960 {
961 	if (mm->hiwater_vm < mm->total_vm)
962 		mm->hiwater_vm = mm->total_vm;
963 }
964 
965 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
966 					 struct mm_struct *mm)
967 {
968 	unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
969 
970 	if (*maxrss < hiwater_rss)
971 		*maxrss = hiwater_rss;
972 }
973 
974 void sync_mm_rss(struct task_struct *task, struct mm_struct *mm);
975 
976 /*
977  * A callback you can register to apply pressure to ageable caches.
978  *
979  * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
980  * look through the least-recently-used 'nr_to_scan' entries and
981  * attempt to free them up.  It should return the number of objects
982  * which remain in the cache.  If it returns -1, it means it cannot do
983  * any scanning at this time (eg. there is a risk of deadlock).
984  *
985  * The 'gfpmask' refers to the allocation we are currently trying to
986  * fulfil.
987  *
988  * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
989  * querying the cache size, so a fastpath for that case is appropriate.
990  */
991 struct shrinker {
992 	int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
993 	int seeks;	/* seeks to recreate an obj */
994 
995 	/* These are for internal use */
996 	struct list_head list;
997 	long nr;	/* objs pending delete */
998 };
999 #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
1000 extern void register_shrinker(struct shrinker *);
1001 extern void unregister_shrinker(struct shrinker *);
1002 
1003 int vma_wants_writenotify(struct vm_area_struct *vma);
1004 
1005 extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
1006 
1007 #ifdef __PAGETABLE_PUD_FOLDED
1008 static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
1009 						unsigned long address)
1010 {
1011 	return 0;
1012 }
1013 #else
1014 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
1015 #endif
1016 
1017 #ifdef __PAGETABLE_PMD_FOLDED
1018 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
1019 						unsigned long address)
1020 {
1021 	return 0;
1022 }
1023 #else
1024 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
1025 #endif
1026 
1027 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
1028 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
1029 
1030 /*
1031  * The following ifdef needed to get the 4level-fixup.h header to work.
1032  * Remove it when 4level-fixup.h has been removed.
1033  */
1034 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
1035 static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1036 {
1037 	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
1038 		NULL: pud_offset(pgd, address);
1039 }
1040 
1041 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
1042 {
1043 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
1044 		NULL: pmd_offset(pud, address);
1045 }
1046 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
1047 
1048 #if USE_SPLIT_PTLOCKS
1049 /*
1050  * We tuck a spinlock to guard each pagetable page into its struct page,
1051  * at page->private, with BUILD_BUG_ON to make sure that this will not
1052  * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
1053  * When freeing, reset page->mapping so free_pages_check won't complain.
1054  */
1055 #define __pte_lockptr(page)	&((page)->ptl)
1056 #define pte_lock_init(_page)	do {					\
1057 	spin_lock_init(__pte_lockptr(_page));				\
1058 } while (0)
1059 #define pte_lock_deinit(page)	((page)->mapping = NULL)
1060 #define pte_lockptr(mm, pmd)	({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
1061 #else	/* !USE_SPLIT_PTLOCKS */
1062 /*
1063  * We use mm->page_table_lock to guard all pagetable pages of the mm.
1064  */
1065 #define pte_lock_init(page)	do {} while (0)
1066 #define pte_lock_deinit(page)	do {} while (0)
1067 #define pte_lockptr(mm, pmd)	({(void)(pmd); &(mm)->page_table_lock;})
1068 #endif /* USE_SPLIT_PTLOCKS */
1069 
1070 static inline void pgtable_page_ctor(struct page *page)
1071 {
1072 	pte_lock_init(page);
1073 	inc_zone_page_state(page, NR_PAGETABLE);
1074 }
1075 
1076 static inline void pgtable_page_dtor(struct page *page)
1077 {
1078 	pte_lock_deinit(page);
1079 	dec_zone_page_state(page, NR_PAGETABLE);
1080 }
1081 
1082 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
1083 ({							\
1084 	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
1085 	pte_t *__pte = pte_offset_map(pmd, address);	\
1086 	*(ptlp) = __ptl;				\
1087 	spin_lock(__ptl);				\
1088 	__pte;						\
1089 })
1090 
1091 #define pte_unmap_unlock(pte, ptl)	do {		\
1092 	spin_unlock(ptl);				\
1093 	pte_unmap(pte);					\
1094 } while (0)
1095 
1096 #define pte_alloc_map(mm, pmd, address)			\
1097 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
1098 		NULL: pte_offset_map(pmd, address))
1099 
1100 #define pte_alloc_map_lock(mm, pmd, address, ptlp)	\
1101 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
1102 		NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1103 
1104 #define pte_alloc_kernel(pmd, address)			\
1105 	((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1106 		NULL: pte_offset_kernel(pmd, address))
1107 
1108 extern void free_area_init(unsigned long * zones_size);
1109 extern void free_area_init_node(int nid, unsigned long * zones_size,
1110 		unsigned long zone_start_pfn, unsigned long *zholes_size);
1111 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
1112 /*
1113  * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
1114  * zones, allocate the backing mem_map and account for memory holes in a more
1115  * architecture independent manner. This is a substitute for creating the
1116  * zone_sizes[] and zholes_size[] arrays and passing them to
1117  * free_area_init_node()
1118  *
1119  * An architecture is expected to register range of page frames backed by
1120  * physical memory with add_active_range() before calling
1121  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1122  * usage, an architecture is expected to do something like
1123  *
1124  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1125  * 							 max_highmem_pfn};
1126  * for_each_valid_physical_page_range()
1127  * 	add_active_range(node_id, start_pfn, end_pfn)
1128  * free_area_init_nodes(max_zone_pfns);
1129  *
1130  * If the architecture guarantees that there are no holes in the ranges
1131  * registered with add_active_range(), free_bootmem_active_regions()
1132  * will call free_bootmem_node() for each registered physical page range.
1133  * Similarly sparse_memory_present_with_active_regions() calls
1134  * memory_present() for each range when SPARSEMEM is enabled.
1135  *
1136  * See mm/page_alloc.c for more information on each function exposed by
1137  * CONFIG_ARCH_POPULATES_NODE_MAP
1138  */
1139 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1140 extern void add_active_range(unsigned int nid, unsigned long start_pfn,
1141 					unsigned long end_pfn);
1142 extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
1143 					unsigned long end_pfn);
1144 extern void remove_all_active_ranges(void);
1145 void sort_node_map(void);
1146 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1147 						unsigned long end_pfn);
1148 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1149 						unsigned long end_pfn);
1150 extern void get_pfn_range_for_nid(unsigned int nid,
1151 			unsigned long *start_pfn, unsigned long *end_pfn);
1152 extern unsigned long find_min_pfn_with_active_regions(void);
1153 extern void free_bootmem_with_active_regions(int nid,
1154 						unsigned long max_low_pfn);
1155 int add_from_early_node_map(struct range *range, int az,
1156 				   int nr_range, int nid);
1157 void *__alloc_memory_core_early(int nodeid, u64 size, u64 align,
1158 				 u64 goal, u64 limit);
1159 typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
1160 extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
1161 extern void sparse_memory_present_with_active_regions(int nid);
1162 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1163 
1164 #if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \
1165     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1166 static inline int __early_pfn_to_nid(unsigned long pfn)
1167 {
1168 	return 0;
1169 }
1170 #else
1171 /* please see mm/page_alloc.c */
1172 extern int __meminit early_pfn_to_nid(unsigned long pfn);
1173 #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1174 /* there is a per-arch backend function. */
1175 extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1176 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1177 #endif
1178 
1179 extern void set_dma_reserve(unsigned long new_dma_reserve);
1180 extern void memmap_init_zone(unsigned long, int, unsigned long,
1181 				unsigned long, enum memmap_context);
1182 extern void setup_per_zone_wmarks(void);
1183 extern void calculate_zone_inactive_ratio(struct zone *zone);
1184 extern void mem_init(void);
1185 extern void __init mmap_init(void);
1186 extern void show_mem(void);
1187 extern void si_meminfo(struct sysinfo * val);
1188 extern void si_meminfo_node(struct sysinfo *val, int nid);
1189 extern int after_bootmem;
1190 
1191 extern void setup_per_cpu_pageset(void);
1192 
1193 extern void zone_pcp_update(struct zone *zone);
1194 
1195 /* nommu.c */
1196 extern atomic_long_t mmap_pages_allocated;
1197 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1198 
1199 /* prio_tree.c */
1200 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1201 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1202 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1203 struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1204 	struct prio_tree_iter *iter);
1205 
1206 #define vma_prio_tree_foreach(vma, iter, root, begin, end)	\
1207 	for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;	\
1208 		(vma = vma_prio_tree_next(vma, iter)); )
1209 
1210 static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1211 					struct list_head *list)
1212 {
1213 	vma->shared.vm_set.parent = NULL;
1214 	list_add_tail(&vma->shared.vm_set.list, list);
1215 }
1216 
1217 /* mmap.c */
1218 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1219 extern int vma_adjust(struct vm_area_struct *vma, unsigned long start,
1220 	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1221 extern struct vm_area_struct *vma_merge(struct mm_struct *,
1222 	struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1223 	unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1224 	struct mempolicy *);
1225 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1226 extern int split_vma(struct mm_struct *,
1227 	struct vm_area_struct *, unsigned long addr, int new_below);
1228 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1229 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1230 	struct rb_node **, struct rb_node *);
1231 extern void unlink_file_vma(struct vm_area_struct *);
1232 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1233 	unsigned long addr, unsigned long len, pgoff_t pgoff);
1234 extern void exit_mmap(struct mm_struct *);
1235 
1236 extern int mm_take_all_locks(struct mm_struct *mm);
1237 extern void mm_drop_all_locks(struct mm_struct *mm);
1238 
1239 #ifdef CONFIG_PROC_FS
1240 /* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1241 extern void added_exe_file_vma(struct mm_struct *mm);
1242 extern void removed_exe_file_vma(struct mm_struct *mm);
1243 #else
1244 static inline void added_exe_file_vma(struct mm_struct *mm)
1245 {}
1246 
1247 static inline void removed_exe_file_vma(struct mm_struct *mm)
1248 {}
1249 #endif /* CONFIG_PROC_FS */
1250 
1251 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1252 extern int install_special_mapping(struct mm_struct *mm,
1253 				   unsigned long addr, unsigned long len,
1254 				   unsigned long flags, struct page **pages);
1255 
1256 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1257 
1258 extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1259 	unsigned long len, unsigned long prot,
1260 	unsigned long flag, unsigned long pgoff);
1261 extern unsigned long mmap_region(struct file *file, unsigned long addr,
1262 	unsigned long len, unsigned long flags,
1263 	unsigned int vm_flags, unsigned long pgoff);
1264 
1265 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1266 	unsigned long len, unsigned long prot,
1267 	unsigned long flag, unsigned long offset)
1268 {
1269 	unsigned long ret = -EINVAL;
1270 	if ((offset + PAGE_ALIGN(len)) < offset)
1271 		goto out;
1272 	if (!(offset & ~PAGE_MASK))
1273 		ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1274 out:
1275 	return ret;
1276 }
1277 
1278 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1279 
1280 extern unsigned long do_brk(unsigned long, unsigned long);
1281 
1282 /* filemap.c */
1283 extern unsigned long page_unuse(struct page *);
1284 extern void truncate_inode_pages(struct address_space *, loff_t);
1285 extern void truncate_inode_pages_range(struct address_space *,
1286 				       loff_t lstart, loff_t lend);
1287 
1288 /* generic vm_area_ops exported for stackable file systems */
1289 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1290 
1291 /* mm/page-writeback.c */
1292 int write_one_page(struct page *page, int wait);
1293 void task_dirty_inc(struct task_struct *tsk);
1294 
1295 /* readahead.c */
1296 #define VM_MAX_READAHEAD	128	/* kbytes */
1297 #define VM_MIN_READAHEAD	16	/* kbytes (includes current page) */
1298 
1299 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1300 			pgoff_t offset, unsigned long nr_to_read);
1301 
1302 void page_cache_sync_readahead(struct address_space *mapping,
1303 			       struct file_ra_state *ra,
1304 			       struct file *filp,
1305 			       pgoff_t offset,
1306 			       unsigned long size);
1307 
1308 void page_cache_async_readahead(struct address_space *mapping,
1309 				struct file_ra_state *ra,
1310 				struct file *filp,
1311 				struct page *pg,
1312 				pgoff_t offset,
1313 				unsigned long size);
1314 
1315 unsigned long max_sane_readahead(unsigned long nr);
1316 unsigned long ra_submit(struct file_ra_state *ra,
1317 			struct address_space *mapping,
1318 			struct file *filp);
1319 
1320 /* Do stack extension */
1321 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1322 #ifdef CONFIG_IA64
1323 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1324 #endif
1325 extern int expand_stack_downwards(struct vm_area_struct *vma,
1326 				  unsigned long address);
1327 
1328 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1329 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1330 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1331 					     struct vm_area_struct **pprev);
1332 
1333 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1334    NULL if none.  Assume start_addr < end_addr. */
1335 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1336 {
1337 	struct vm_area_struct * vma = find_vma(mm,start_addr);
1338 
1339 	if (vma && end_addr <= vma->vm_start)
1340 		vma = NULL;
1341 	return vma;
1342 }
1343 
1344 static inline unsigned long vma_pages(struct vm_area_struct *vma)
1345 {
1346 	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1347 }
1348 
1349 pgprot_t vm_get_page_prot(unsigned long vm_flags);
1350 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1351 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1352 			unsigned long pfn, unsigned long size, pgprot_t);
1353 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1354 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1355 			unsigned long pfn);
1356 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1357 			unsigned long pfn);
1358 
1359 struct page *follow_page(struct vm_area_struct *, unsigned long address,
1360 			unsigned int foll_flags);
1361 #define FOLL_WRITE	0x01	/* check pte is writable */
1362 #define FOLL_TOUCH	0x02	/* mark page accessed */
1363 #define FOLL_GET	0x04	/* do get_page on page */
1364 #define FOLL_DUMP	0x08	/* give error on hole if it would be zero */
1365 #define FOLL_FORCE	0x10	/* get_user_pages read/write w/o permission */
1366 
1367 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1368 			void *data);
1369 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1370 			       unsigned long size, pte_fn_t fn, void *data);
1371 
1372 #ifdef CONFIG_PROC_FS
1373 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1374 #else
1375 static inline void vm_stat_account(struct mm_struct *mm,
1376 			unsigned long flags, struct file *file, long pages)
1377 {
1378 }
1379 #endif /* CONFIG_PROC_FS */
1380 
1381 #ifdef CONFIG_DEBUG_PAGEALLOC
1382 extern int debug_pagealloc_enabled;
1383 
1384 extern void kernel_map_pages(struct page *page, int numpages, int enable);
1385 
1386 static inline void enable_debug_pagealloc(void)
1387 {
1388 	debug_pagealloc_enabled = 1;
1389 }
1390 #ifdef CONFIG_HIBERNATION
1391 extern bool kernel_page_present(struct page *page);
1392 #endif /* CONFIG_HIBERNATION */
1393 #else
1394 static inline void
1395 kernel_map_pages(struct page *page, int numpages, int enable) {}
1396 static inline void enable_debug_pagealloc(void)
1397 {
1398 }
1399 #ifdef CONFIG_HIBERNATION
1400 static inline bool kernel_page_present(struct page *page) { return true; }
1401 #endif /* CONFIG_HIBERNATION */
1402 #endif
1403 
1404 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1405 #ifdef	__HAVE_ARCH_GATE_AREA
1406 int in_gate_area_no_task(unsigned long addr);
1407 int in_gate_area(struct task_struct *task, unsigned long addr);
1408 #else
1409 int in_gate_area_no_task(unsigned long addr);
1410 #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1411 #endif	/* __HAVE_ARCH_GATE_AREA */
1412 
1413 int drop_caches_sysctl_handler(struct ctl_table *, int,
1414 					void __user *, size_t *, loff_t *);
1415 unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1416 			unsigned long lru_pages);
1417 
1418 #ifndef CONFIG_MMU
1419 #define randomize_va_space 0
1420 #else
1421 extern int randomize_va_space;
1422 #endif
1423 
1424 const char * arch_vma_name(struct vm_area_struct *vma);
1425 void print_vma_addr(char *prefix, unsigned long rip);
1426 
1427 void sparse_mem_maps_populate_node(struct page **map_map,
1428 				   unsigned long pnum_begin,
1429 				   unsigned long pnum_end,
1430 				   unsigned long map_count,
1431 				   int nodeid);
1432 
1433 struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1434 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1435 pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1436 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1437 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1438 void *vmemmap_alloc_block(unsigned long size, int node);
1439 void *vmemmap_alloc_block_buf(unsigned long size, int node);
1440 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1441 int vmemmap_populate_basepages(struct page *start_page,
1442 						unsigned long pages, int node);
1443 int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1444 void vmemmap_populate_print_last(void);
1445 
1446 extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
1447 				 size_t size);
1448 extern void refund_locked_memory(struct mm_struct *mm, size_t size);
1449 
1450 enum mf_flags {
1451 	MF_COUNT_INCREASED = 1 << 0,
1452 };
1453 extern void memory_failure(unsigned long pfn, int trapno);
1454 extern int __memory_failure(unsigned long pfn, int trapno, int flags);
1455 extern int unpoison_memory(unsigned long pfn);
1456 extern int sysctl_memory_failure_early_kill;
1457 extern int sysctl_memory_failure_recovery;
1458 extern void shake_page(struct page *p, int access);
1459 extern atomic_long_t mce_bad_pages;
1460 extern int soft_offline_page(struct page *page, int flags);
1461 
1462 #endif /* __KERNEL__ */
1463 #endif /* _LINUX_MM_H */
1464