1#ifndef _LINUX_MM_H
2#define _LINUX_MM_H
3
4#include <linux/errno.h>
5
6#ifdef __KERNEL__
7
8#include <linux/mmdebug.h>
9#include <linux/gfp.h>
10#include <linux/bug.h>
11#include <linux/list.h>
12#include <linux/mmzone.h>
13#include <linux/rbtree.h>
14#include <linux/atomic.h>
15#include <linux/debug_locks.h>
16#include <linux/mm_types.h>
17#include <linux/range.h>
18#include <linux/pfn.h>
19#include <linux/bit_spinlock.h>
20#include <linux/shrinker.h>
21#include <linux/resource.h>
22
23struct mempolicy;
24struct anon_vma;
25struct anon_vma_chain;
26struct file_ra_state;
27struct user_struct;
28struct writeback_control;
29
30#ifndef CONFIG_NEED_MULTIPLE_NODES	/* Don't use mapnrs, do it properly */
31extern unsigned long max_mapnr;
32
33static inline void set_max_mapnr(unsigned long limit)
34{
35	max_mapnr = limit;
36}
37#else
38static inline void set_max_mapnr(unsigned long limit) { }
39#endif
40
41extern unsigned long totalram_pages;
42extern void * high_memory;
43extern int page_cluster;
44
45#ifdef CONFIG_SYSCTL
46extern int sysctl_legacy_va_layout;
47#else
48#define sysctl_legacy_va_layout 0
49#endif
50
51#include <asm/page.h>
52#include <asm/pgtable.h>
53#include <asm/processor.h>
54
55#ifndef __pa_symbol
56#define __pa_symbol(x)  __pa(RELOC_HIDE((unsigned long)(x), 0))
57#endif
58
59extern unsigned long sysctl_user_reserve_kbytes;
60extern unsigned long sysctl_admin_reserve_kbytes;
61
62extern int sysctl_overcommit_memory;
63extern int sysctl_overcommit_ratio;
64extern unsigned long sysctl_overcommit_kbytes;
65
66extern int overcommit_ratio_handler(struct ctl_table *, int, void __user *,
67				    size_t *, loff_t *);
68extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
69				    size_t *, loff_t *);
70
71#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
72
73/* to align the pointer to the (next) page boundary */
74#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
75
76/* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
77#define PAGE_ALIGNED(addr)	IS_ALIGNED((unsigned long)addr, PAGE_SIZE)
78
79/*
80 * Linux kernel virtual memory manager primitives.
81 * The idea being to have a "virtual" mm in the same way
82 * we have a virtual fs - giving a cleaner interface to the
83 * mm details, and allowing different kinds of memory mappings
84 * (from shared memory to executable loading to arbitrary
85 * mmap() functions).
86 */
87
88extern struct kmem_cache *vm_area_cachep;
89
90#ifndef CONFIG_MMU
91extern struct rb_root nommu_region_tree;
92extern struct rw_semaphore nommu_region_sem;
93
94extern unsigned int kobjsize(const void *objp);
95#endif
96
97/*
98 * vm_flags in vm_area_struct, see mm_types.h.
99 */
100#define VM_NONE		0x00000000
101
102#define VM_READ		0x00000001	/* currently active flags */
103#define VM_WRITE	0x00000002
104#define VM_EXEC		0x00000004
105#define VM_SHARED	0x00000008
106
107/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
108#define VM_MAYREAD	0x00000010	/* limits for mprotect() etc */
109#define VM_MAYWRITE	0x00000020
110#define VM_MAYEXEC	0x00000040
111#define VM_MAYSHARE	0x00000080
112
113#define VM_GROWSDOWN	0x00000100	/* general info on the segment */
114#define VM_PFNMAP	0x00000400	/* Page-ranges managed without "struct page", just pure PFN */
115#define VM_DENYWRITE	0x00000800	/* ETXTBSY on write attempts.. */
116
117#define VM_LOCKED	0x00002000
118#define VM_IO           0x00004000	/* Memory mapped I/O or similar */
119
120					/* Used by sys_madvise() */
121#define VM_SEQ_READ	0x00008000	/* App will access data sequentially */
122#define VM_RAND_READ	0x00010000	/* App will not benefit from clustered reads */
123
124#define VM_DONTCOPY	0x00020000      /* Do not copy this vma on fork */
125#define VM_DONTEXPAND	0x00040000	/* Cannot expand with mremap() */
126#define VM_ACCOUNT	0x00100000	/* Is a VM accounted object */
127#define VM_NORESERVE	0x00200000	/* should the VM suppress accounting */
128#define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */
129#define VM_NONLINEAR	0x00800000	/* Is non-linear (remap_file_pages) */
130#define VM_ARCH_1	0x01000000	/* Architecture-specific flag */
131#define VM_DONTDUMP	0x04000000	/* Do not include in the core dump */
132
133#ifdef CONFIG_MEM_SOFT_DIRTY
134# define VM_SOFTDIRTY	0x08000000	/* Not soft dirty clean area */
135#else
136# define VM_SOFTDIRTY	0
137#endif
138
139#define VM_MIXEDMAP	0x10000000	/* Can contain "struct page" and pure PFN pages */
140#define VM_HUGEPAGE	0x20000000	/* MADV_HUGEPAGE marked this vma */
141#define VM_NOHUGEPAGE	0x40000000	/* MADV_NOHUGEPAGE marked this vma */
142#define VM_MERGEABLE	0x80000000	/* KSM may merge identical pages */
143
144#if defined(CONFIG_X86)
145# define VM_PAT		VM_ARCH_1	/* PAT reserves whole VMA at once (x86) */
146#elif defined(CONFIG_PPC)
147# define VM_SAO		VM_ARCH_1	/* Strong Access Ordering (powerpc) */
148#elif defined(CONFIG_PARISC)
149# define VM_GROWSUP	VM_ARCH_1
150#elif defined(CONFIG_METAG)
151# define VM_GROWSUP	VM_ARCH_1
152#elif defined(CONFIG_IA64)
153# define VM_GROWSUP	VM_ARCH_1
154#elif !defined(CONFIG_MMU)
155# define VM_MAPPED_COPY	VM_ARCH_1	/* T if mapped copy of data (nommu mmap) */
156#endif
157
158#ifndef VM_GROWSUP
159# define VM_GROWSUP	VM_NONE
160#endif
161
162/* Bits set in the VMA until the stack is in its final location */
163#define VM_STACK_INCOMPLETE_SETUP	(VM_RAND_READ | VM_SEQ_READ)
164
165#ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
166#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
167#endif
168
169#ifdef CONFIG_STACK_GROWSUP
170#define VM_STACK_FLAGS	(VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
171#else
172#define VM_STACK_FLAGS	(VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
173#endif
174
175/*
176 * Special vmas that are non-mergable, non-mlock()able.
177 * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
178 */
179#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
180
181/* This mask defines which mm->def_flags a process can inherit its parent */
182#define VM_INIT_DEF_MASK	VM_NOHUGEPAGE
183
184/*
185 * mapping from the currently active vm_flags protection bits (the
186 * low four bits) to a page protection mask..
187 */
188extern pgprot_t protection_map[16];
189
190#define FAULT_FLAG_WRITE	0x01	/* Fault was a write access */
191#define FAULT_FLAG_NONLINEAR	0x02	/* Fault was via a nonlinear mapping */
192#define FAULT_FLAG_MKWRITE	0x04	/* Fault was mkwrite of existing pte */
193#define FAULT_FLAG_ALLOW_RETRY	0x08	/* Retry fault if blocking */
194#define FAULT_FLAG_RETRY_NOWAIT	0x10	/* Don't drop mmap_sem and wait when retrying */
195#define FAULT_FLAG_KILLABLE	0x20	/* The fault task is in SIGKILL killable region */
196#define FAULT_FLAG_TRIED	0x40	/* second try */
197#define FAULT_FLAG_USER		0x80	/* The fault originated in userspace */
198
199/*
200 * vm_fault is filled by the the pagefault handler and passed to the vma's
201 * ->fault function. The vma's ->fault is responsible for returning a bitmask
202 * of VM_FAULT_xxx flags that give details about how the fault was handled.
203 *
204 * pgoff should be used in favour of virtual_address, if possible. If pgoff
205 * is used, one may implement ->remap_pages to get nonlinear mapping support.
206 */
207struct vm_fault {
208	unsigned int flags;		/* FAULT_FLAG_xxx flags */
209	pgoff_t pgoff;			/* Logical page offset based on vma */
210	void __user *virtual_address;	/* Faulting virtual address */
211
212	struct page *page;		/* ->fault handlers should return a
213					 * page here, unless VM_FAULT_NOPAGE
214					 * is set (which is also implied by
215					 * VM_FAULT_ERROR).
216					 */
217	/* for ->map_pages() only */
218	pgoff_t max_pgoff;		/* map pages for offset from pgoff till
219					 * max_pgoff inclusive */
220	pte_t *pte;			/* pte entry associated with ->pgoff */
221};
222
223/*
224 * These are the virtual MM functions - opening of an area, closing and
225 * unmapping it (needed to keep files on disk up-to-date etc), pointer
226 * to the functions called when a no-page or a wp-page exception occurs.
227 */
228struct vm_operations_struct {
229	void (*open)(struct vm_area_struct * area);
230	void (*close)(struct vm_area_struct * area);
231	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
232	void (*map_pages)(struct vm_area_struct *vma, struct vm_fault *vmf);
233
234	/* notification that a previously read-only page is about to become
235	 * writable, if an error is returned it will cause a SIGBUS */
236	int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
237
238	/* called by access_process_vm when get_user_pages() fails, typically
239	 * for use by special VMAs that can switch between memory and hardware
240	 */
241	int (*access)(struct vm_area_struct *vma, unsigned long addr,
242		      void *buf, int len, int write);
243
244	/* Called by the /proc/PID/maps code to ask the vma whether it
245	 * has a special name.  Returning non-NULL will also cause this
246	 * vma to be dumped unconditionally. */
247	const char *(*name)(struct vm_area_struct *vma);
248
249#ifdef CONFIG_NUMA
250	/*
251	 * set_policy() op must add a reference to any non-NULL @new mempolicy
252	 * to hold the policy upon return.  Caller should pass NULL @new to
253	 * remove a policy and fall back to surrounding context--i.e. do not
254	 * install a MPOL_DEFAULT policy, nor the task or system default
255	 * mempolicy.
256	 */
257	int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
258
259	/*
260	 * get_policy() op must add reference [mpol_get()] to any policy at
261	 * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
262	 * in mm/mempolicy.c will do this automatically.
263	 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
264	 * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
265	 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
266	 * must return NULL--i.e., do not "fallback" to task or system default
267	 * policy.
268	 */
269	struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
270					unsigned long addr);
271	int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
272		const nodemask_t *to, unsigned long flags);
273#endif
274	/* called by sys_remap_file_pages() to populate non-linear mapping */
275	int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr,
276			   unsigned long size, pgoff_t pgoff);
277};
278
279struct mmu_gather;
280struct inode;
281
282#define page_private(page)		((page)->private)
283#define set_page_private(page, v)	((page)->private = (v))
284
285/* It's valid only if the page is free path or free_list */
286static inline void set_freepage_migratetype(struct page *page, int migratetype)
287{
288	page->index = migratetype;
289}
290
291/* It's valid only if the page is free path or free_list */
292static inline int get_freepage_migratetype(struct page *page)
293{
294	return page->index;
295}
296
297/*
298 * FIXME: take this include out, include page-flags.h in
299 * files which need it (119 of them)
300 */
301#include <linux/page-flags.h>
302#include <linux/huge_mm.h>
303
304/*
305 * Methods to modify the page usage count.
306 *
307 * What counts for a page usage:
308 * - cache mapping   (page->mapping)
309 * - private data    (page->private)
310 * - page mapped in a task's page tables, each mapping
311 *   is counted separately
312 *
313 * Also, many kernel routines increase the page count before a critical
314 * routine so they can be sure the page doesn't go away from under them.
315 */
316
317/*
318 * Drop a ref, return true if the refcount fell to zero (the page has no users)
319 */
320static inline int put_page_testzero(struct page *page)
321{
322	VM_BUG_ON_PAGE(atomic_read(&page->_count) == 0, page);
323	return atomic_dec_and_test(&page->_count);
324}
325
326/*
327 * Try to grab a ref unless the page has a refcount of zero, return false if
328 * that is the case.
329 * This can be called when MMU is off so it must not access
330 * any of the virtual mappings.
331 */
332static inline int get_page_unless_zero(struct page *page)
333{
334	return atomic_inc_not_zero(&page->_count);
335}
336
337/*
338 * Try to drop a ref unless the page has a refcount of one, return false if
339 * that is the case.
340 * This is to make sure that the refcount won't become zero after this drop.
341 * This can be called when MMU is off so it must not access
342 * any of the virtual mappings.
343 */
344static inline int put_page_unless_one(struct page *page)
345{
346	return atomic_add_unless(&page->_count, -1, 1);
347}
348
349extern int page_is_ram(unsigned long pfn);
350extern int region_is_ram(resource_size_t phys_addr, unsigned long size);
351
352/* Support for virtually mapped pages */
353struct page *vmalloc_to_page(const void *addr);
354unsigned long vmalloc_to_pfn(const void *addr);
355
356/*
357 * Determine if an address is within the vmalloc range
358 *
359 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
360 * is no special casing required.
361 */
362static inline int is_vmalloc_addr(const void *x)
363{
364#ifdef CONFIG_MMU
365	unsigned long addr = (unsigned long)x;
366
367	return addr >= VMALLOC_START && addr < VMALLOC_END;
368#else
369	return 0;
370#endif
371}
372#ifdef CONFIG_MMU
373extern int is_vmalloc_or_module_addr(const void *x);
374#else
375static inline int is_vmalloc_or_module_addr(const void *x)
376{
377	return 0;
378}
379#endif
380
381extern void kvfree(const void *addr);
382
383static inline void compound_lock(struct page *page)
384{
385#ifdef CONFIG_TRANSPARENT_HUGEPAGE
386	VM_BUG_ON_PAGE(PageSlab(page), page);
387	bit_spin_lock(PG_compound_lock, &page->flags);
388#endif
389}
390
391static inline void compound_unlock(struct page *page)
392{
393#ifdef CONFIG_TRANSPARENT_HUGEPAGE
394	VM_BUG_ON_PAGE(PageSlab(page), page);
395	bit_spin_unlock(PG_compound_lock, &page->flags);
396#endif
397}
398
399static inline unsigned long compound_lock_irqsave(struct page *page)
400{
401	unsigned long uninitialized_var(flags);
402#ifdef CONFIG_TRANSPARENT_HUGEPAGE
403	local_irq_save(flags);
404	compound_lock(page);
405#endif
406	return flags;
407}
408
409static inline void compound_unlock_irqrestore(struct page *page,
410					      unsigned long flags)
411{
412#ifdef CONFIG_TRANSPARENT_HUGEPAGE
413	compound_unlock(page);
414	local_irq_restore(flags);
415#endif
416}
417
418static inline struct page *compound_head_by_tail(struct page *tail)
419{
420	struct page *head = tail->first_page;
421
422	/*
423	 * page->first_page may be a dangling pointer to an old
424	 * compound page, so recheck that it is still a tail
425	 * page before returning.
426	 */
427	smp_rmb();
428	if (likely(PageTail(tail)))
429		return head;
430	return tail;
431}
432
433static inline struct page *compound_head(struct page *page)
434{
435	if (unlikely(PageTail(page)))
436		return compound_head_by_tail(page);
437	return page;
438}
439
440/*
441 * The atomic page->_mapcount, starts from -1: so that transitions
442 * both from it and to it can be tracked, using atomic_inc_and_test
443 * and atomic_add_negative(-1).
444 */
445static inline void page_mapcount_reset(struct page *page)
446{
447	atomic_set(&(page)->_mapcount, -1);
448}
449
450static inline int page_mapcount(struct page *page)
451{
452	return atomic_read(&(page)->_mapcount) + 1;
453}
454
455static inline int page_count(struct page *page)
456{
457	return atomic_read(&compound_head(page)->_count);
458}
459
460#ifdef CONFIG_HUGETLB_PAGE
461extern int PageHeadHuge(struct page *page_head);
462#else /* CONFIG_HUGETLB_PAGE */
463static inline int PageHeadHuge(struct page *page_head)
464{
465	return 0;
466}
467#endif /* CONFIG_HUGETLB_PAGE */
468
469static inline bool __compound_tail_refcounted(struct page *page)
470{
471	return !PageSlab(page) && !PageHeadHuge(page);
472}
473
474/*
475 * This takes a head page as parameter and tells if the
476 * tail page reference counting can be skipped.
477 *
478 * For this to be safe, PageSlab and PageHeadHuge must remain true on
479 * any given page where they return true here, until all tail pins
480 * have been released.
481 */
482static inline bool compound_tail_refcounted(struct page *page)
483{
484	VM_BUG_ON_PAGE(!PageHead(page), page);
485	return __compound_tail_refcounted(page);
486}
487
488static inline void get_huge_page_tail(struct page *page)
489{
490	/*
491	 * __split_huge_page_refcount() cannot run from under us.
492	 */
493	VM_BUG_ON_PAGE(!PageTail(page), page);
494	VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
495	VM_BUG_ON_PAGE(atomic_read(&page->_count) != 0, page);
496	if (compound_tail_refcounted(page->first_page))
497		atomic_inc(&page->_mapcount);
498}
499
500extern bool __get_page_tail(struct page *page);
501
502static inline void get_page(struct page *page)
503{
504	if (unlikely(PageTail(page)))
505		if (likely(__get_page_tail(page)))
506			return;
507	/*
508	 * Getting a normal page or the head of a compound page
509	 * requires to already have an elevated page->_count.
510	 */
511	VM_BUG_ON_PAGE(atomic_read(&page->_count) <= 0, page);
512	atomic_inc(&page->_count);
513}
514
515static inline struct page *virt_to_head_page(const void *x)
516{
517	struct page *page = virt_to_page(x);
518	return compound_head(page);
519}
520
521/*
522 * Setup the page count before being freed into the page allocator for
523 * the first time (boot or memory hotplug)
524 */
525static inline void init_page_count(struct page *page)
526{
527	atomic_set(&page->_count, 1);
528}
529
530/*
531 * PageBuddy() indicate that the page is free and in the buddy system
532 * (see mm/page_alloc.c).
533 *
534 * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
535 * -2 so that an underflow of the page_mapcount() won't be mistaken
536 * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
537 * efficiently by most CPU architectures.
538 */
539#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
540
541static inline int PageBuddy(struct page *page)
542{
543	return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
544}
545
546static inline void __SetPageBuddy(struct page *page)
547{
548	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
549	atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
550}
551
552static inline void __ClearPageBuddy(struct page *page)
553{
554	VM_BUG_ON_PAGE(!PageBuddy(page), page);
555	atomic_set(&page->_mapcount, -1);
556}
557
558#define PAGE_BALLOON_MAPCOUNT_VALUE (-256)
559
560static inline int PageBalloon(struct page *page)
561{
562	return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE;
563}
564
565static inline void __SetPageBalloon(struct page *page)
566{
567	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
568	atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE);
569}
570
571static inline void __ClearPageBalloon(struct page *page)
572{
573	VM_BUG_ON_PAGE(!PageBalloon(page), page);
574	atomic_set(&page->_mapcount, -1);
575}
576
577void put_page(struct page *page);
578void put_pages_list(struct list_head *pages);
579
580void split_page(struct page *page, unsigned int order);
581int split_free_page(struct page *page);
582
583/*
584 * Compound pages have a destructor function.  Provide a
585 * prototype for that function and accessor functions.
586 * These are _only_ valid on the head of a PG_compound page.
587 */
588typedef void compound_page_dtor(struct page *);
589
590static inline void set_compound_page_dtor(struct page *page,
591						compound_page_dtor *dtor)
592{
593	page[1].lru.next = (void *)dtor;
594}
595
596static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
597{
598	return (compound_page_dtor *)page[1].lru.next;
599}
600
601static inline int compound_order(struct page *page)
602{
603	if (!PageHead(page))
604		return 0;
605	return (unsigned long)page[1].lru.prev;
606}
607
608static inline void set_compound_order(struct page *page, unsigned long order)
609{
610	page[1].lru.prev = (void *)order;
611}
612
613#ifdef CONFIG_MMU
614/*
615 * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
616 * servicing faults for write access.  In the normal case, do always want
617 * pte_mkwrite.  But get_user_pages can cause write faults for mappings
618 * that do not have writing enabled, when used by access_process_vm.
619 */
620static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
621{
622	if (likely(vma->vm_flags & VM_WRITE))
623		pte = pte_mkwrite(pte);
624	return pte;
625}
626
627void do_set_pte(struct vm_area_struct *vma, unsigned long address,
628		struct page *page, pte_t *pte, bool write, bool anon);
629#endif
630
631/*
632 * Multiple processes may "see" the same page. E.g. for untouched
633 * mappings of /dev/null, all processes see the same page full of
634 * zeroes, and text pages of executables and shared libraries have
635 * only one copy in memory, at most, normally.
636 *
637 * For the non-reserved pages, page_count(page) denotes a reference count.
638 *   page_count() == 0 means the page is free. page->lru is then used for
639 *   freelist management in the buddy allocator.
640 *   page_count() > 0  means the page has been allocated.
641 *
642 * Pages are allocated by the slab allocator in order to provide memory
643 * to kmalloc and kmem_cache_alloc. In this case, the management of the
644 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
645 * unless a particular usage is carefully commented. (the responsibility of
646 * freeing the kmalloc memory is the caller's, of course).
647 *
648 * A page may be used by anyone else who does a __get_free_page().
649 * In this case, page_count still tracks the references, and should only
650 * be used through the normal accessor functions. The top bits of page->flags
651 * and page->virtual store page management information, but all other fields
652 * are unused and could be used privately, carefully. The management of this
653 * page is the responsibility of the one who allocated it, and those who have
654 * subsequently been given references to it.
655 *
656 * The other pages (we may call them "pagecache pages") are completely
657 * managed by the Linux memory manager: I/O, buffers, swapping etc.
658 * The following discussion applies only to them.
659 *
660 * A pagecache page contains an opaque `private' member, which belongs to the
661 * page's address_space. Usually, this is the address of a circular list of
662 * the page's disk buffers. PG_private must be set to tell the VM to call
663 * into the filesystem to release these pages.
664 *
665 * A page may belong to an inode's memory mapping. In this case, page->mapping
666 * is the pointer to the inode, and page->index is the file offset of the page,
667 * in units of PAGE_CACHE_SIZE.
668 *
669 * If pagecache pages are not associated with an inode, they are said to be
670 * anonymous pages. These may become associated with the swapcache, and in that
671 * case PG_swapcache is set, and page->private is an offset into the swapcache.
672 *
673 * In either case (swapcache or inode backed), the pagecache itself holds one
674 * reference to the page. Setting PG_private should also increment the
675 * refcount. The each user mapping also has a reference to the page.
676 *
677 * The pagecache pages are stored in a per-mapping radix tree, which is
678 * rooted at mapping->page_tree, and indexed by offset.
679 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
680 * lists, we instead now tag pages as dirty/writeback in the radix tree.
681 *
682 * All pagecache pages may be subject to I/O:
683 * - inode pages may need to be read from disk,
684 * - inode pages which have been modified and are MAP_SHARED may need
685 *   to be written back to the inode on disk,
686 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
687 *   modified may need to be swapped out to swap space and (later) to be read
688 *   back into memory.
689 */
690
691/*
692 * The zone field is never updated after free_area_init_core()
693 * sets it, so none of the operations on it need to be atomic.
694 */
695
696/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
697#define SECTIONS_PGOFF		((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
698#define NODES_PGOFF		(SECTIONS_PGOFF - NODES_WIDTH)
699#define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
700#define LAST_CPUPID_PGOFF	(ZONES_PGOFF - LAST_CPUPID_WIDTH)
701
702/*
703 * Define the bit shifts to access each section.  For non-existent
704 * sections we define the shift as 0; that plus a 0 mask ensures
705 * the compiler will optimise away reference to them.
706 */
707#define SECTIONS_PGSHIFT	(SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
708#define NODES_PGSHIFT		(NODES_PGOFF * (NODES_WIDTH != 0))
709#define ZONES_PGSHIFT		(ZONES_PGOFF * (ZONES_WIDTH != 0))
710#define LAST_CPUPID_PGSHIFT	(LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
711
712/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
713#ifdef NODE_NOT_IN_PAGE_FLAGS
714#define ZONEID_SHIFT		(SECTIONS_SHIFT + ZONES_SHIFT)
715#define ZONEID_PGOFF		((SECTIONS_PGOFF < ZONES_PGOFF)? \
716						SECTIONS_PGOFF : ZONES_PGOFF)
717#else
718#define ZONEID_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
719#define ZONEID_PGOFF		((NODES_PGOFF < ZONES_PGOFF)? \
720						NODES_PGOFF : ZONES_PGOFF)
721#endif
722
723#define ZONEID_PGSHIFT		(ZONEID_PGOFF * (ZONEID_SHIFT != 0))
724
725#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
726#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
727#endif
728
729#define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
730#define NODES_MASK		((1UL << NODES_WIDTH) - 1)
731#define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
732#define LAST_CPUPID_MASK	((1UL << LAST_CPUPID_SHIFT) - 1)
733#define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
734
735static inline enum zone_type page_zonenum(const struct page *page)
736{
737	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
738}
739
740#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
741#define SECTION_IN_PAGE_FLAGS
742#endif
743
744/*
745 * The identification function is mainly used by the buddy allocator for
746 * determining if two pages could be buddies. We are not really identifying
747 * the zone since we could be using the section number id if we do not have
748 * node id available in page flags.
749 * We only guarantee that it will return the same value for two combinable
750 * pages in a zone.
751 */
752static inline int page_zone_id(struct page *page)
753{
754	return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
755}
756
757static inline int zone_to_nid(struct zone *zone)
758{
759#ifdef CONFIG_NUMA
760	return zone->node;
761#else
762	return 0;
763#endif
764}
765
766#ifdef NODE_NOT_IN_PAGE_FLAGS
767extern int page_to_nid(const struct page *page);
768#else
769static inline int page_to_nid(const struct page *page)
770{
771	return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
772}
773#endif
774
775#ifdef CONFIG_NUMA_BALANCING
776static inline int cpu_pid_to_cpupid(int cpu, int pid)
777{
778	return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
779}
780
781static inline int cpupid_to_pid(int cpupid)
782{
783	return cpupid & LAST__PID_MASK;
784}
785
786static inline int cpupid_to_cpu(int cpupid)
787{
788	return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
789}
790
791static inline int cpupid_to_nid(int cpupid)
792{
793	return cpu_to_node(cpupid_to_cpu(cpupid));
794}
795
796static inline bool cpupid_pid_unset(int cpupid)
797{
798	return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
799}
800
801static inline bool cpupid_cpu_unset(int cpupid)
802{
803	return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
804}
805
806static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
807{
808	return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
809}
810
811#define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
812#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
813static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
814{
815	return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
816}
817
818static inline int page_cpupid_last(struct page *page)
819{
820	return page->_last_cpupid;
821}
822static inline void page_cpupid_reset_last(struct page *page)
823{
824	page->_last_cpupid = -1 & LAST_CPUPID_MASK;
825}
826#else
827static inline int page_cpupid_last(struct page *page)
828{
829	return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
830}
831
832extern int page_cpupid_xchg_last(struct page *page, int cpupid);
833
834static inline void page_cpupid_reset_last(struct page *page)
835{
836	int cpupid = (1 << LAST_CPUPID_SHIFT) - 1;
837
838	page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
839	page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
840}
841#endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
842#else /* !CONFIG_NUMA_BALANCING */
843static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
844{
845	return page_to_nid(page); /* XXX */
846}
847
848static inline int page_cpupid_last(struct page *page)
849{
850	return page_to_nid(page); /* XXX */
851}
852
853static inline int cpupid_to_nid(int cpupid)
854{
855	return -1;
856}
857
858static inline int cpupid_to_pid(int cpupid)
859{
860	return -1;
861}
862
863static inline int cpupid_to_cpu(int cpupid)
864{
865	return -1;
866}
867
868static inline int cpu_pid_to_cpupid(int nid, int pid)
869{
870	return -1;
871}
872
873static inline bool cpupid_pid_unset(int cpupid)
874{
875	return 1;
876}
877
878static inline void page_cpupid_reset_last(struct page *page)
879{
880}
881
882static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
883{
884	return false;
885}
886#endif /* CONFIG_NUMA_BALANCING */
887
888static inline struct zone *page_zone(const struct page *page)
889{
890	return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
891}
892
893#ifdef SECTION_IN_PAGE_FLAGS
894static inline void set_page_section(struct page *page, unsigned long section)
895{
896	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
897	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
898}
899
900static inline unsigned long page_to_section(const struct page *page)
901{
902	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
903}
904#endif
905
906static inline void set_page_zone(struct page *page, enum zone_type zone)
907{
908	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
909	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
910}
911
912static inline void set_page_node(struct page *page, unsigned long node)
913{
914	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
915	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
916}
917
918static inline void set_page_links(struct page *page, enum zone_type zone,
919	unsigned long node, unsigned long pfn)
920{
921	set_page_zone(page, zone);
922	set_page_node(page, node);
923#ifdef SECTION_IN_PAGE_FLAGS
924	set_page_section(page, pfn_to_section_nr(pfn));
925#endif
926}
927
928/*
929 * Some inline functions in vmstat.h depend on page_zone()
930 */
931#include <linux/vmstat.h>
932
933static __always_inline void *lowmem_page_address(const struct page *page)
934{
935	return __va(PFN_PHYS(page_to_pfn(page)));
936}
937
938#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
939#define HASHED_PAGE_VIRTUAL
940#endif
941
942#if defined(WANT_PAGE_VIRTUAL)
943static inline void *page_address(const struct page *page)
944{
945	return page->virtual;
946}
947static inline void set_page_address(struct page *page, void *address)
948{
949	page->virtual = address;
950}
951#define page_address_init()  do { } while(0)
952#endif
953
954#if defined(HASHED_PAGE_VIRTUAL)
955void *page_address(const struct page *page);
956void set_page_address(struct page *page, void *virtual);
957void page_address_init(void);
958#endif
959
960#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
961#define page_address(page) lowmem_page_address(page)
962#define set_page_address(page, address)  do { } while(0)
963#define page_address_init()  do { } while(0)
964#endif
965
966/*
967 * On an anonymous page mapped into a user virtual memory area,
968 * page->mapping points to its anon_vma, not to a struct address_space;
969 * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
970 *
971 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
972 * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
973 * and then page->mapping points, not to an anon_vma, but to a private
974 * structure which KSM associates with that merged page.  See ksm.h.
975 *
976 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
977 *
978 * Please note that, confusingly, "page_mapping" refers to the inode
979 * address_space which maps the page from disk; whereas "page_mapped"
980 * refers to user virtual address space into which the page is mapped.
981 */
982#define PAGE_MAPPING_ANON	1
983#define PAGE_MAPPING_KSM	2
984#define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
985
986extern struct address_space *page_mapping(struct page *page);
987
988/* Neutral page->mapping pointer to address_space or anon_vma or other */
989static inline void *page_rmapping(struct page *page)
990{
991	return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
992}
993
994extern struct address_space *__page_file_mapping(struct page *);
995
996static inline
997struct address_space *page_file_mapping(struct page *page)
998{
999	if (unlikely(PageSwapCache(page)))
1000		return __page_file_mapping(page);
1001
1002	return page->mapping;
1003}
1004
1005static inline int PageAnon(struct page *page)
1006{
1007	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
1008}
1009
1010/*
1011 * Return the pagecache index of the passed page.  Regular pagecache pages
1012 * use ->index whereas swapcache pages use ->private
1013 */
1014static inline pgoff_t page_index(struct page *page)
1015{
1016	if (unlikely(PageSwapCache(page)))
1017		return page_private(page);
1018	return page->index;
1019}
1020
1021extern pgoff_t __page_file_index(struct page *page);
1022
1023/*
1024 * Return the file index of the page. Regular pagecache pages use ->index
1025 * whereas swapcache pages use swp_offset(->private)
1026 */
1027static inline pgoff_t page_file_index(struct page *page)
1028{
1029	if (unlikely(PageSwapCache(page)))
1030		return __page_file_index(page);
1031
1032	return page->index;
1033}
1034
1035/*
1036 * Return true if this page is mapped into pagetables.
1037 */
1038static inline int page_mapped(struct page *page)
1039{
1040	return atomic_read(&(page)->_mapcount) >= 0;
1041}
1042
1043/*
1044 * Different kinds of faults, as returned by handle_mm_fault().
1045 * Used to decide whether a process gets delivered SIGBUS or
1046 * just gets major/minor fault counters bumped up.
1047 */
1048
1049#define VM_FAULT_MINOR	0 /* For backwards compat. Remove me quickly. */
1050
1051#define VM_FAULT_OOM	0x0001
1052#define VM_FAULT_SIGBUS	0x0002
1053#define VM_FAULT_MAJOR	0x0004
1054#define VM_FAULT_WRITE	0x0008	/* Special case for get_user_pages */
1055#define VM_FAULT_HWPOISON 0x0010	/* Hit poisoned small page */
1056#define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
1057
1058#define VM_FAULT_NOPAGE	0x0100	/* ->fault installed the pte, not return page */
1059#define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
1060#define VM_FAULT_RETRY	0x0400	/* ->fault blocked, must retry */
1061#define VM_FAULT_FALLBACK 0x0800	/* huge page fault failed, fall back to small */
1062
1063#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
1064
1065#define VM_FAULT_ERROR	(VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
1066			 VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE)
1067
1068/* Encode hstate index for a hwpoisoned large page */
1069#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
1070#define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
1071
1072/*
1073 * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
1074 */
1075extern void pagefault_out_of_memory(void);
1076
1077#define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
1078
1079/*
1080 * Flags passed to show_mem() and show_free_areas() to suppress output in
1081 * various contexts.
1082 */
1083#define SHOW_MEM_FILTER_NODES		(0x0001u)	/* disallowed nodes */
1084
1085extern void show_free_areas(unsigned int flags);
1086extern bool skip_free_areas_node(unsigned int flags, int nid);
1087
1088void shmem_set_file(struct vm_area_struct *vma, struct file *file);
1089int shmem_zero_setup(struct vm_area_struct *);
1090#ifdef CONFIG_SHMEM
1091bool shmem_mapping(struct address_space *mapping);
1092#else
1093static inline bool shmem_mapping(struct address_space *mapping)
1094{
1095	return false;
1096}
1097#endif
1098
1099extern int can_do_mlock(void);
1100extern int user_shm_lock(size_t, struct user_struct *);
1101extern void user_shm_unlock(size_t, struct user_struct *);
1102
1103/*
1104 * Parameter block passed down to zap_pte_range in exceptional cases.
1105 */
1106struct zap_details {
1107	struct vm_area_struct *nonlinear_vma;	/* Check page->index if set */
1108	struct address_space *check_mapping;	/* Check page->mapping if set */
1109	pgoff_t	first_index;			/* Lowest page->index to unmap */
1110	pgoff_t last_index;			/* Highest page->index to unmap */
1111};
1112
1113struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
1114		pte_t pte);
1115
1116int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
1117		unsigned long size);
1118void zap_page_range(struct vm_area_struct *vma, unsigned long address,
1119		unsigned long size, struct zap_details *);
1120void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
1121		unsigned long start, unsigned long end);
1122
1123/**
1124 * mm_walk - callbacks for walk_page_range
1125 * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
1126 * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
1127 * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
1128 *	       this handler is required to be able to handle
1129 *	       pmd_trans_huge() pmds.  They may simply choose to
1130 *	       split_huge_page() instead of handling it explicitly.
1131 * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
1132 * @pte_hole: if set, called for each hole at all levels
1133 * @hugetlb_entry: if set, called for each hugetlb entry
1134 *		   *Caution*: The caller must hold mmap_sem() if @hugetlb_entry
1135 * 			      is used.
1136 *
1137 * (see walk_page_range for more details)
1138 */
1139struct mm_walk {
1140	int (*pgd_entry)(pgd_t *pgd, unsigned long addr,
1141			 unsigned long next, struct mm_walk *walk);
1142	int (*pud_entry)(pud_t *pud, unsigned long addr,
1143	                 unsigned long next, struct mm_walk *walk);
1144	int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
1145			 unsigned long next, struct mm_walk *walk);
1146	int (*pte_entry)(pte_t *pte, unsigned long addr,
1147			 unsigned long next, struct mm_walk *walk);
1148	int (*pte_hole)(unsigned long addr, unsigned long next,
1149			struct mm_walk *walk);
1150	int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
1151			     unsigned long addr, unsigned long next,
1152			     struct mm_walk *walk);
1153	struct mm_struct *mm;
1154	void *private;
1155};
1156
1157int walk_page_range(unsigned long addr, unsigned long end,
1158		struct mm_walk *walk);
1159void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
1160		unsigned long end, unsigned long floor, unsigned long ceiling);
1161int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
1162			struct vm_area_struct *vma);
1163void unmap_mapping_range(struct address_space *mapping,
1164		loff_t const holebegin, loff_t const holelen, int even_cows);
1165int follow_pfn(struct vm_area_struct *vma, unsigned long address,
1166	unsigned long *pfn);
1167int follow_phys(struct vm_area_struct *vma, unsigned long address,
1168		unsigned int flags, unsigned long *prot, resource_size_t *phys);
1169int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
1170			void *buf, int len, int write);
1171
1172static inline void unmap_shared_mapping_range(struct address_space *mapping,
1173		loff_t const holebegin, loff_t const holelen)
1174{
1175	unmap_mapping_range(mapping, holebegin, holelen, 0);
1176}
1177
1178extern void truncate_pagecache(struct inode *inode, loff_t new);
1179extern void truncate_setsize(struct inode *inode, loff_t newsize);
1180void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
1181void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
1182int truncate_inode_page(struct address_space *mapping, struct page *page);
1183int generic_error_remove_page(struct address_space *mapping, struct page *page);
1184int invalidate_inode_page(struct page *page);
1185
1186#ifdef CONFIG_MMU
1187extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
1188			unsigned long address, unsigned int flags);
1189extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
1190			    unsigned long address, unsigned int fault_flags);
1191#else
1192static inline int handle_mm_fault(struct mm_struct *mm,
1193			struct vm_area_struct *vma, unsigned long address,
1194			unsigned int flags)
1195{
1196	/* should never happen if there's no MMU */
1197	BUG();
1198	return VM_FAULT_SIGBUS;
1199}
1200static inline int fixup_user_fault(struct task_struct *tsk,
1201		struct mm_struct *mm, unsigned long address,
1202		unsigned int fault_flags)
1203{
1204	/* should never happen if there's no MMU */
1205	BUG();
1206	return -EFAULT;
1207}
1208#endif
1209
1210extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
1211extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1212		void *buf, int len, int write);
1213
1214long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
1215		      unsigned long start, unsigned long nr_pages,
1216		      unsigned int foll_flags, struct page **pages,
1217		      struct vm_area_struct **vmas, int *nonblocking);
1218long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
1219		    unsigned long start, unsigned long nr_pages,
1220		    int write, int force, struct page **pages,
1221		    struct vm_area_struct **vmas);
1222int get_user_pages_fast(unsigned long start, int nr_pages, int write,
1223			struct page **pages);
1224struct kvec;
1225int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
1226			struct page **pages);
1227int get_kernel_page(unsigned long start, int write, struct page **pages);
1228struct page *get_dump_page(unsigned long addr);
1229
1230extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
1231extern void do_invalidatepage(struct page *page, unsigned int offset,
1232			      unsigned int length);
1233
1234int __set_page_dirty_nobuffers(struct page *page);
1235int __set_page_dirty_no_writeback(struct page *page);
1236int redirty_page_for_writepage(struct writeback_control *wbc,
1237				struct page *page);
1238void account_page_dirtied(struct page *page, struct address_space *mapping);
1239int set_page_dirty(struct page *page);
1240int set_page_dirty_lock(struct page *page);
1241int clear_page_dirty_for_io(struct page *page);
1242int get_cmdline(struct task_struct *task, char *buffer, int buflen);
1243
1244/* Is the vma a continuation of the stack vma above it? */
1245static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
1246{
1247	return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
1248}
1249
1250static inline int stack_guard_page_start(struct vm_area_struct *vma,
1251					     unsigned long addr)
1252{
1253	return (vma->vm_flags & VM_GROWSDOWN) &&
1254		(vma->vm_start == addr) &&
1255		!vma_growsdown(vma->vm_prev, addr);
1256}
1257
1258/* Is the vma a continuation of the stack vma below it? */
1259static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
1260{
1261	return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
1262}
1263
1264static inline int stack_guard_page_end(struct vm_area_struct *vma,
1265					   unsigned long addr)
1266{
1267	return (vma->vm_flags & VM_GROWSUP) &&
1268		(vma->vm_end == addr) &&
1269		!vma_growsup(vma->vm_next, addr);
1270}
1271
1272extern struct task_struct *task_of_stack(struct task_struct *task,
1273				struct vm_area_struct *vma, bool in_group);
1274
1275extern unsigned long move_page_tables(struct vm_area_struct *vma,
1276		unsigned long old_addr, struct vm_area_struct *new_vma,
1277		unsigned long new_addr, unsigned long len,
1278		bool need_rmap_locks);
1279extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
1280			      unsigned long end, pgprot_t newprot,
1281			      int dirty_accountable, int prot_numa);
1282extern int mprotect_fixup(struct vm_area_struct *vma,
1283			  struct vm_area_struct **pprev, unsigned long start,
1284			  unsigned long end, unsigned long newflags);
1285
1286/*
1287 * doesn't attempt to fault and will return short.
1288 */
1289int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
1290			  struct page **pages);
1291/*
1292 * per-process(per-mm_struct) statistics.
1293 */
1294static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
1295{
1296	long val = atomic_long_read(&mm->rss_stat.count[member]);
1297
1298#ifdef SPLIT_RSS_COUNTING
1299	/*
1300	 * counter is updated in asynchronous manner and may go to minus.
1301	 * But it's never be expected number for users.
1302	 */
1303	if (val < 0)
1304		val = 0;
1305#endif
1306	return (unsigned long)val;
1307}
1308
1309static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
1310{
1311	atomic_long_add(value, &mm->rss_stat.count[member]);
1312}
1313
1314static inline void inc_mm_counter(struct mm_struct *mm, int member)
1315{
1316	atomic_long_inc(&mm->rss_stat.count[member]);
1317}
1318
1319static inline void dec_mm_counter(struct mm_struct *mm, int member)
1320{
1321	atomic_long_dec(&mm->rss_stat.count[member]);
1322}
1323
1324static inline unsigned long get_mm_rss(struct mm_struct *mm)
1325{
1326	return get_mm_counter(mm, MM_FILEPAGES) +
1327		get_mm_counter(mm, MM_ANONPAGES);
1328}
1329
1330static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
1331{
1332	return max(mm->hiwater_rss, get_mm_rss(mm));
1333}
1334
1335static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
1336{
1337	return max(mm->hiwater_vm, mm->total_vm);
1338}
1339
1340static inline void update_hiwater_rss(struct mm_struct *mm)
1341{
1342	unsigned long _rss = get_mm_rss(mm);
1343
1344	if ((mm)->hiwater_rss < _rss)
1345		(mm)->hiwater_rss = _rss;
1346}
1347
1348static inline void update_hiwater_vm(struct mm_struct *mm)
1349{
1350	if (mm->hiwater_vm < mm->total_vm)
1351		mm->hiwater_vm = mm->total_vm;
1352}
1353
1354static inline void reset_mm_hiwater_rss(struct mm_struct *mm)
1355{
1356	mm->hiwater_rss = get_mm_rss(mm);
1357}
1358
1359static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
1360					 struct mm_struct *mm)
1361{
1362	unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
1363
1364	if (*maxrss < hiwater_rss)
1365		*maxrss = hiwater_rss;
1366}
1367
1368#if defined(SPLIT_RSS_COUNTING)
1369void sync_mm_rss(struct mm_struct *mm);
1370#else
1371static inline void sync_mm_rss(struct mm_struct *mm)
1372{
1373}
1374#endif
1375
1376int vma_wants_writenotify(struct vm_area_struct *vma);
1377
1378extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
1379			       spinlock_t **ptl);
1380static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
1381				    spinlock_t **ptl)
1382{
1383	pte_t *ptep;
1384	__cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
1385	return ptep;
1386}
1387
1388#ifdef __PAGETABLE_PUD_FOLDED
1389static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
1390						unsigned long address)
1391{
1392	return 0;
1393}
1394#else
1395int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
1396#endif
1397
1398#ifdef __PAGETABLE_PMD_FOLDED
1399static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
1400						unsigned long address)
1401{
1402	return 0;
1403}
1404#else
1405int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
1406#endif
1407
1408int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
1409		pmd_t *pmd, unsigned long address);
1410int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
1411
1412/*
1413 * The following ifdef needed to get the 4level-fixup.h header to work.
1414 * Remove it when 4level-fixup.h has been removed.
1415 */
1416#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
1417static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1418{
1419	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
1420		NULL: pud_offset(pgd, address);
1421}
1422
1423static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
1424{
1425	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
1426		NULL: pmd_offset(pud, address);
1427}
1428#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
1429
1430#if USE_SPLIT_PTE_PTLOCKS
1431#if ALLOC_SPLIT_PTLOCKS
1432void __init ptlock_cache_init(void);
1433extern bool ptlock_alloc(struct page *page);
1434extern void ptlock_free(struct page *page);
1435
1436static inline spinlock_t *ptlock_ptr(struct page *page)
1437{
1438	return page->ptl;
1439}
1440#else /* ALLOC_SPLIT_PTLOCKS */
1441static inline void ptlock_cache_init(void)
1442{
1443}
1444
1445static inline bool ptlock_alloc(struct page *page)
1446{
1447	return true;
1448}
1449
1450static inline void ptlock_free(struct page *page)
1451{
1452}
1453
1454static inline spinlock_t *ptlock_ptr(struct page *page)
1455{
1456	return &page->ptl;
1457}
1458#endif /* ALLOC_SPLIT_PTLOCKS */
1459
1460static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
1461{
1462	return ptlock_ptr(pmd_page(*pmd));
1463}
1464
1465static inline bool ptlock_init(struct page *page)
1466{
1467	/*
1468	 * prep_new_page() initialize page->private (and therefore page->ptl)
1469	 * with 0. Make sure nobody took it in use in between.
1470	 *
1471	 * It can happen if arch try to use slab for page table allocation:
1472	 * slab code uses page->slab_cache and page->first_page (for tail
1473	 * pages), which share storage with page->ptl.
1474	 */
1475	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
1476	if (!ptlock_alloc(page))
1477		return false;
1478	spin_lock_init(ptlock_ptr(page));
1479	return true;
1480}
1481
1482/* Reset page->mapping so free_pages_check won't complain. */
1483static inline void pte_lock_deinit(struct page *page)
1484{
1485	page->mapping = NULL;
1486	ptlock_free(page);
1487}
1488
1489#else	/* !USE_SPLIT_PTE_PTLOCKS */
1490/*
1491 * We use mm->page_table_lock to guard all pagetable pages of the mm.
1492 */
1493static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
1494{
1495	return &mm->page_table_lock;
1496}
1497static inline void ptlock_cache_init(void) {}
1498static inline bool ptlock_init(struct page *page) { return true; }
1499static inline void pte_lock_deinit(struct page *page) {}
1500#endif /* USE_SPLIT_PTE_PTLOCKS */
1501
1502static inline void pgtable_init(void)
1503{
1504	ptlock_cache_init();
1505	pgtable_cache_init();
1506}
1507
1508static inline bool pgtable_page_ctor(struct page *page)
1509{
1510	inc_zone_page_state(page, NR_PAGETABLE);
1511	return ptlock_init(page);
1512}
1513
1514static inline void pgtable_page_dtor(struct page *page)
1515{
1516	pte_lock_deinit(page);
1517	dec_zone_page_state(page, NR_PAGETABLE);
1518}
1519
1520#define pte_offset_map_lock(mm, pmd, address, ptlp)	\
1521({							\
1522	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
1523	pte_t *__pte = pte_offset_map(pmd, address);	\
1524	*(ptlp) = __ptl;				\
1525	spin_lock(__ptl);				\
1526	__pte;						\
1527})
1528
1529#define pte_unmap_unlock(pte, ptl)	do {		\
1530	spin_unlock(ptl);				\
1531	pte_unmap(pte);					\
1532} while (0)
1533
1534#define pte_alloc_map(mm, vma, pmd, address)				\
1535	((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma,	\
1536							pmd, address))?	\
1537	 NULL: pte_offset_map(pmd, address))
1538
1539#define pte_alloc_map_lock(mm, pmd, address, ptlp)	\
1540	((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL,	\
1541							pmd, address))?	\
1542		NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1543
1544#define pte_alloc_kernel(pmd, address)			\
1545	((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1546		NULL: pte_offset_kernel(pmd, address))
1547
1548#if USE_SPLIT_PMD_PTLOCKS
1549
1550static struct page *pmd_to_page(pmd_t *pmd)
1551{
1552	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
1553	return virt_to_page((void *)((unsigned long) pmd & mask));
1554}
1555
1556static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
1557{
1558	return ptlock_ptr(pmd_to_page(pmd));
1559}
1560
1561static inline bool pgtable_pmd_page_ctor(struct page *page)
1562{
1563#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1564	page->pmd_huge_pte = NULL;
1565#endif
1566	return ptlock_init(page);
1567}
1568
1569static inline void pgtable_pmd_page_dtor(struct page *page)
1570{
1571#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1572	VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
1573#endif
1574	ptlock_free(page);
1575}
1576
1577#define pmd_huge_pte(mm, pmd) (pmd_to_page(pmd)->pmd_huge_pte)
1578
1579#else
1580
1581static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
1582{
1583	return &mm->page_table_lock;
1584}
1585
1586static inline bool pgtable_pmd_page_ctor(struct page *page) { return true; }
1587static inline void pgtable_pmd_page_dtor(struct page *page) {}
1588
1589#define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
1590
1591#endif
1592
1593static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
1594{
1595	spinlock_t *ptl = pmd_lockptr(mm, pmd);
1596	spin_lock(ptl);
1597	return ptl;
1598}
1599
1600extern void free_area_init(unsigned long * zones_size);
1601extern void free_area_init_node(int nid, unsigned long * zones_size,
1602		unsigned long zone_start_pfn, unsigned long *zholes_size);
1603extern void free_initmem(void);
1604
1605/*
1606 * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
1607 * into the buddy system. The freed pages will be poisoned with pattern
1608 * "poison" if it's within range [0, UCHAR_MAX].
1609 * Return pages freed into the buddy system.
1610 */
1611extern unsigned long free_reserved_area(void *start, void *end,
1612					int poison, char *s);
1613
1614#ifdef	CONFIG_HIGHMEM
1615/*
1616 * Free a highmem page into the buddy system, adjusting totalhigh_pages
1617 * and totalram_pages.
1618 */
1619extern void free_highmem_page(struct page *page);
1620#endif
1621
1622extern void adjust_managed_page_count(struct page *page, long count);
1623extern void mem_init_print_info(const char *str);
1624
1625/* Free the reserved page into the buddy system, so it gets managed. */
1626static inline void __free_reserved_page(struct page *page)
1627{
1628	ClearPageReserved(page);
1629	init_page_count(page);
1630	__free_page(page);
1631}
1632
1633static inline void free_reserved_page(struct page *page)
1634{
1635	__free_reserved_page(page);
1636	adjust_managed_page_count(page, 1);
1637}
1638
1639static inline void mark_page_reserved(struct page *page)
1640{
1641	SetPageReserved(page);
1642	adjust_managed_page_count(page, -1);
1643}
1644
1645/*
1646 * Default method to free all the __init memory into the buddy system.
1647 * The freed pages will be poisoned with pattern "poison" if it's within
1648 * range [0, UCHAR_MAX].
1649 * Return pages freed into the buddy system.
1650 */
1651static inline unsigned long free_initmem_default(int poison)
1652{
1653	extern char __init_begin[], __init_end[];
1654
1655	return free_reserved_area(&__init_begin, &__init_end,
1656				  poison, "unused kernel");
1657}
1658
1659static inline unsigned long get_num_physpages(void)
1660{
1661	int nid;
1662	unsigned long phys_pages = 0;
1663
1664	for_each_online_node(nid)
1665		phys_pages += node_present_pages(nid);
1666
1667	return phys_pages;
1668}
1669
1670#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1671/*
1672 * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
1673 * zones, allocate the backing mem_map and account for memory holes in a more
1674 * architecture independent manner. This is a substitute for creating the
1675 * zone_sizes[] and zholes_size[] arrays and passing them to
1676 * free_area_init_node()
1677 *
1678 * An architecture is expected to register range of page frames backed by
1679 * physical memory with memblock_add[_node]() before calling
1680 * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1681 * usage, an architecture is expected to do something like
1682 *
1683 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1684 * 							 max_highmem_pfn};
1685 * for_each_valid_physical_page_range()
1686 * 	memblock_add_node(base, size, nid)
1687 * free_area_init_nodes(max_zone_pfns);
1688 *
1689 * free_bootmem_with_active_regions() calls free_bootmem_node() for each
1690 * registered physical page range.  Similarly
1691 * sparse_memory_present_with_active_regions() calls memory_present() for
1692 * each range when SPARSEMEM is enabled.
1693 *
1694 * See mm/page_alloc.c for more information on each function exposed by
1695 * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
1696 */
1697extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1698unsigned long node_map_pfn_alignment(void);
1699unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1700						unsigned long end_pfn);
1701extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1702						unsigned long end_pfn);
1703extern void get_pfn_range_for_nid(unsigned int nid,
1704			unsigned long *start_pfn, unsigned long *end_pfn);
1705extern unsigned long find_min_pfn_with_active_regions(void);
1706extern void free_bootmem_with_active_regions(int nid,
1707						unsigned long max_low_pfn);
1708extern void sparse_memory_present_with_active_regions(int nid);
1709
1710#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
1711
1712#if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
1713    !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1714static inline int __early_pfn_to_nid(unsigned long pfn)
1715{
1716	return 0;
1717}
1718#else
1719/* please see mm/page_alloc.c */
1720extern int __meminit early_pfn_to_nid(unsigned long pfn);
1721/* there is a per-arch backend function. */
1722extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1723#endif
1724
1725extern void set_dma_reserve(unsigned long new_dma_reserve);
1726extern void memmap_init_zone(unsigned long, int, unsigned long,
1727				unsigned long, enum memmap_context);
1728extern void setup_per_zone_wmarks(void);
1729extern int __meminit init_per_zone_wmark_min(void);
1730extern void mem_init(void);
1731extern void __init mmap_init(void);
1732extern void show_mem(unsigned int flags);
1733extern void si_meminfo(struct sysinfo * val);
1734extern void si_meminfo_node(struct sysinfo *val, int nid);
1735
1736extern __printf(3, 4)
1737void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...);
1738
1739extern void setup_per_cpu_pageset(void);
1740
1741extern void zone_pcp_update(struct zone *zone);
1742extern void zone_pcp_reset(struct zone *zone);
1743
1744/* page_alloc.c */
1745extern int min_free_kbytes;
1746
1747/* nommu.c */
1748extern atomic_long_t mmap_pages_allocated;
1749extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1750
1751/* interval_tree.c */
1752void vma_interval_tree_insert(struct vm_area_struct *node,
1753			      struct rb_root *root);
1754void vma_interval_tree_insert_after(struct vm_area_struct *node,
1755				    struct vm_area_struct *prev,
1756				    struct rb_root *root);
1757void vma_interval_tree_remove(struct vm_area_struct *node,
1758			      struct rb_root *root);
1759struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
1760				unsigned long start, unsigned long last);
1761struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
1762				unsigned long start, unsigned long last);
1763
1764#define vma_interval_tree_foreach(vma, root, start, last)		\
1765	for (vma = vma_interval_tree_iter_first(root, start, last);	\
1766	     vma; vma = vma_interval_tree_iter_next(vma, start, last))
1767
1768static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1769					struct list_head *list)
1770{
1771	list_add_tail(&vma->shared.nonlinear, list);
1772}
1773
1774void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
1775				   struct rb_root *root);
1776void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
1777				   struct rb_root *root);
1778struct anon_vma_chain *anon_vma_interval_tree_iter_first(
1779	struct rb_root *root, unsigned long start, unsigned long last);
1780struct anon_vma_chain *anon_vma_interval_tree_iter_next(
1781	struct anon_vma_chain *node, unsigned long start, unsigned long last);
1782#ifdef CONFIG_DEBUG_VM_RB
1783void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
1784#endif
1785
1786#define anon_vma_interval_tree_foreach(avc, root, start, last)		 \
1787	for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
1788	     avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
1789
1790/* mmap.c */
1791extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1792extern int vma_adjust(struct vm_area_struct *vma, unsigned long start,
1793	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1794extern struct vm_area_struct *vma_merge(struct mm_struct *,
1795	struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1796	unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1797	struct mempolicy *, const char __user *);
1798extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1799extern int split_vma(struct mm_struct *,
1800	struct vm_area_struct *, unsigned long addr, int new_below);
1801extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1802extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1803	struct rb_node **, struct rb_node *);
1804extern void unlink_file_vma(struct vm_area_struct *);
1805extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1806	unsigned long addr, unsigned long len, pgoff_t pgoff,
1807	bool *need_rmap_locks);
1808extern void exit_mmap(struct mm_struct *);
1809
1810static inline int check_data_rlimit(unsigned long rlim,
1811				    unsigned long new,
1812				    unsigned long start,
1813				    unsigned long end_data,
1814				    unsigned long start_data)
1815{
1816	if (rlim < RLIM_INFINITY) {
1817		if (((new - start) + (end_data - start_data)) > rlim)
1818			return -ENOSPC;
1819	}
1820
1821	return 0;
1822}
1823
1824extern int mm_take_all_locks(struct mm_struct *mm);
1825extern void mm_drop_all_locks(struct mm_struct *mm);
1826
1827extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
1828extern struct file *get_mm_exe_file(struct mm_struct *mm);
1829
1830extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1831extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
1832				   unsigned long addr, unsigned long len,
1833				   unsigned long flags,
1834				   const struct vm_special_mapping *spec);
1835/* This is an obsolete alternative to _install_special_mapping. */
1836extern int install_special_mapping(struct mm_struct *mm,
1837				   unsigned long addr, unsigned long len,
1838				   unsigned long flags, struct page **pages);
1839
1840extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1841
1842extern unsigned long mmap_region(struct file *file, unsigned long addr,
1843	unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
1844extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1845	unsigned long len, unsigned long prot, unsigned long flags,
1846	unsigned long pgoff, unsigned long *populate);
1847extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1848
1849#ifdef CONFIG_MMU
1850extern int __mm_populate(unsigned long addr, unsigned long len,
1851			 int ignore_errors);
1852static inline void mm_populate(unsigned long addr, unsigned long len)
1853{
1854	/* Ignore errors */
1855	(void) __mm_populate(addr, len, 1);
1856}
1857#else
1858static inline void mm_populate(unsigned long addr, unsigned long len) {}
1859#endif
1860
1861/* These take the mm semaphore themselves */
1862extern unsigned long vm_brk(unsigned long, unsigned long);
1863extern int vm_munmap(unsigned long, size_t);
1864extern unsigned long vm_mmap(struct file *, unsigned long,
1865        unsigned long, unsigned long,
1866        unsigned long, unsigned long);
1867
1868struct vm_unmapped_area_info {
1869#define VM_UNMAPPED_AREA_TOPDOWN 1
1870	unsigned long flags;
1871	unsigned long length;
1872	unsigned long low_limit;
1873	unsigned long high_limit;
1874	unsigned long align_mask;
1875	unsigned long align_offset;
1876};
1877
1878extern unsigned long unmapped_area(struct vm_unmapped_area_info *info);
1879extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info);
1880
1881/*
1882 * Search for an unmapped address range.
1883 *
1884 * We are looking for a range that:
1885 * - does not intersect with any VMA;
1886 * - is contained within the [low_limit, high_limit) interval;
1887 * - is at least the desired size.
1888 * - satisfies (begin_addr & align_mask) == (align_offset & align_mask)
1889 */
1890static inline unsigned long
1891vm_unmapped_area(struct vm_unmapped_area_info *info)
1892{
1893	if (!(info->flags & VM_UNMAPPED_AREA_TOPDOWN))
1894		return unmapped_area(info);
1895	else
1896		return unmapped_area_topdown(info);
1897}
1898
1899/* truncate.c */
1900extern void truncate_inode_pages(struct address_space *, loff_t);
1901extern void truncate_inode_pages_range(struct address_space *,
1902				       loff_t lstart, loff_t lend);
1903extern void truncate_inode_pages_final(struct address_space *);
1904
1905/* generic vm_area_ops exported for stackable file systems */
1906extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1907extern void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf);
1908extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1909
1910/* mm/page-writeback.c */
1911int write_one_page(struct page *page, int wait);
1912void task_dirty_inc(struct task_struct *tsk);
1913
1914/* readahead.c */
1915#define VM_MAX_READAHEAD	128	/* kbytes */
1916#define VM_MIN_READAHEAD	16	/* kbytes (includes current page) */
1917
1918int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1919			pgoff_t offset, unsigned long nr_to_read);
1920
1921void page_cache_sync_readahead(struct address_space *mapping,
1922			       struct file_ra_state *ra,
1923			       struct file *filp,
1924			       pgoff_t offset,
1925			       unsigned long size);
1926
1927void page_cache_async_readahead(struct address_space *mapping,
1928				struct file_ra_state *ra,
1929				struct file *filp,
1930				struct page *pg,
1931				pgoff_t offset,
1932				unsigned long size);
1933
1934unsigned long max_sane_readahead(unsigned long nr);
1935
1936/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
1937extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1938
1939/* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
1940extern int expand_downwards(struct vm_area_struct *vma,
1941		unsigned long address);
1942#if VM_GROWSUP
1943extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1944#else
1945  #define expand_upwards(vma, address) do { } while (0)
1946#endif
1947
1948/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1949extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1950extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1951					     struct vm_area_struct **pprev);
1952
1953/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1954   NULL if none.  Assume start_addr < end_addr. */
1955static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1956{
1957	struct vm_area_struct * vma = find_vma(mm,start_addr);
1958
1959	if (vma && end_addr <= vma->vm_start)
1960		vma = NULL;
1961	return vma;
1962}
1963
1964static inline unsigned long vma_pages(struct vm_area_struct *vma)
1965{
1966	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1967}
1968
1969/* Look up the first VMA which exactly match the interval vm_start ... vm_end */
1970static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
1971				unsigned long vm_start, unsigned long vm_end)
1972{
1973	struct vm_area_struct *vma = find_vma(mm, vm_start);
1974
1975	if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
1976		vma = NULL;
1977
1978	return vma;
1979}
1980
1981#ifdef CONFIG_MMU
1982pgprot_t vm_get_page_prot(unsigned long vm_flags);
1983void vma_set_page_prot(struct vm_area_struct *vma);
1984#else
1985static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
1986{
1987	return __pgprot(0);
1988}
1989static inline void vma_set_page_prot(struct vm_area_struct *vma)
1990{
1991	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
1992}
1993#endif
1994
1995#ifdef CONFIG_NUMA_BALANCING
1996unsigned long change_prot_numa(struct vm_area_struct *vma,
1997			unsigned long start, unsigned long end);
1998#endif
1999
2000struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
2001int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
2002			unsigned long pfn, unsigned long size, pgprot_t);
2003int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
2004int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
2005			unsigned long pfn);
2006int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
2007			unsigned long pfn);
2008int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
2009
2010
2011struct page *follow_page_mask(struct vm_area_struct *vma,
2012			      unsigned long address, unsigned int foll_flags,
2013			      unsigned int *page_mask);
2014
2015static inline struct page *follow_page(struct vm_area_struct *vma,
2016		unsigned long address, unsigned int foll_flags)
2017{
2018	unsigned int unused_page_mask;
2019	return follow_page_mask(vma, address, foll_flags, &unused_page_mask);
2020}
2021
2022#define FOLL_WRITE	0x01	/* check pte is writable */
2023#define FOLL_TOUCH	0x02	/* mark page accessed */
2024#define FOLL_GET	0x04	/* do get_page on page */
2025#define FOLL_DUMP	0x08	/* give error on hole if it would be zero */
2026#define FOLL_FORCE	0x10	/* get_user_pages read/write w/o permission */
2027#define FOLL_NOWAIT	0x20	/* if a disk transfer is needed, start the IO
2028				 * and return without waiting upon it */
2029#define FOLL_MLOCK	0x40	/* mark page as mlocked */
2030#define FOLL_SPLIT	0x80	/* don't return transhuge pages, split them */
2031#define FOLL_HWPOISON	0x100	/* check page is hwpoisoned */
2032#define FOLL_NUMA	0x200	/* force NUMA hinting page fault */
2033#define FOLL_MIGRATION	0x400	/* wait for page to replace migration entry */
2034#define FOLL_TRIED	0x800	/* a retry, previous pass started an IO */
2035
2036typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
2037			void *data);
2038extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
2039			       unsigned long size, pte_fn_t fn, void *data);
2040
2041#ifdef CONFIG_PROC_FS
2042void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
2043#else
2044static inline void vm_stat_account(struct mm_struct *mm,
2045			unsigned long flags, struct file *file, long pages)
2046{
2047	mm->total_vm += pages;
2048}
2049#endif /* CONFIG_PROC_FS */
2050
2051#ifdef CONFIG_DEBUG_PAGEALLOC
2052extern void kernel_map_pages(struct page *page, int numpages, int enable);
2053#ifdef CONFIG_HIBERNATION
2054extern bool kernel_page_present(struct page *page);
2055#endif /* CONFIG_HIBERNATION */
2056#else
2057static inline void
2058kernel_map_pages(struct page *page, int numpages, int enable) {}
2059#ifdef CONFIG_HIBERNATION
2060static inline bool kernel_page_present(struct page *page) { return true; }
2061#endif /* CONFIG_HIBERNATION */
2062#endif
2063
2064#ifdef __HAVE_ARCH_GATE_AREA
2065extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
2066extern int in_gate_area_no_mm(unsigned long addr);
2067extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
2068#else
2069static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
2070{
2071	return NULL;
2072}
2073static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
2074static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
2075{
2076	return 0;
2077}
2078#endif	/* __HAVE_ARCH_GATE_AREA */
2079
2080#ifdef CONFIG_SYSCTL
2081extern int sysctl_drop_caches;
2082int drop_caches_sysctl_handler(struct ctl_table *, int,
2083					void __user *, size_t *, loff_t *);
2084#endif
2085
2086unsigned long shrink_slab(struct shrink_control *shrink,
2087			  unsigned long nr_pages_scanned,
2088			  unsigned long lru_pages);
2089
2090#ifndef CONFIG_MMU
2091#define randomize_va_space 0
2092#else
2093extern int randomize_va_space;
2094#endif
2095
2096const char * arch_vma_name(struct vm_area_struct *vma);
2097void print_vma_addr(char *prefix, unsigned long rip);
2098
2099void sparse_mem_maps_populate_node(struct page **map_map,
2100				   unsigned long pnum_begin,
2101				   unsigned long pnum_end,
2102				   unsigned long map_count,
2103				   int nodeid);
2104
2105struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
2106pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
2107pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
2108pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
2109pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
2110void *vmemmap_alloc_block(unsigned long size, int node);
2111void *vmemmap_alloc_block_buf(unsigned long size, int node);
2112void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
2113int vmemmap_populate_basepages(unsigned long start, unsigned long end,
2114			       int node);
2115int vmemmap_populate(unsigned long start, unsigned long end, int node);
2116void vmemmap_populate_print_last(void);
2117#ifdef CONFIG_MEMORY_HOTPLUG
2118void vmemmap_free(unsigned long start, unsigned long end);
2119#endif
2120void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
2121				  unsigned long size);
2122
2123enum mf_flags {
2124	MF_COUNT_INCREASED = 1 << 0,
2125	MF_ACTION_REQUIRED = 1 << 1,
2126	MF_MUST_KILL = 1 << 2,
2127	MF_SOFT_OFFLINE = 1 << 3,
2128};
2129extern int memory_failure(unsigned long pfn, int trapno, int flags);
2130extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
2131extern int unpoison_memory(unsigned long pfn);
2132extern int sysctl_memory_failure_early_kill;
2133extern int sysctl_memory_failure_recovery;
2134extern void shake_page(struct page *p, int access);
2135extern atomic_long_t num_poisoned_pages;
2136extern int soft_offline_page(struct page *page, int flags);
2137
2138#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
2139extern void clear_huge_page(struct page *page,
2140			    unsigned long addr,
2141			    unsigned int pages_per_huge_page);
2142extern void copy_user_huge_page(struct page *dst, struct page *src,
2143				unsigned long addr, struct vm_area_struct *vma,
2144				unsigned int pages_per_huge_page);
2145#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
2146
2147#ifdef CONFIG_DEBUG_PAGEALLOC
2148extern unsigned int _debug_guardpage_minorder;
2149
2150static inline unsigned int debug_guardpage_minorder(void)
2151{
2152	return _debug_guardpage_minorder;
2153}
2154
2155static inline bool page_is_guard(struct page *page)
2156{
2157	return test_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
2158}
2159#else
2160static inline unsigned int debug_guardpage_minorder(void) { return 0; }
2161static inline bool page_is_guard(struct page *page) { return false; }
2162#endif /* CONFIG_DEBUG_PAGEALLOC */
2163
2164#if MAX_NUMNODES > 1
2165void __init setup_nr_node_ids(void);
2166#else
2167static inline void setup_nr_node_ids(void) {}
2168#endif
2169
2170#endif /* __KERNEL__ */
2171#endif /* _LINUX_MM_H */
2172