1#ifndef _LINUX_MM_H
2#define _LINUX_MM_H
3
4#include <linux/sched.h>
5#include <linux/errno.h>
6#include <linux/capability.h>
7
8#ifdef __KERNEL__
9
10#include <linux/gfp.h>
11#include <linux/list.h>
12#include <linux/mmzone.h>
13#include <linux/rbtree.h>
14#include <linux/prio_tree.h>
15#include <linux/fs.h>
16#include <linux/mutex.h>
17#include <linux/debug_locks.h>
18
19struct mempolicy;
20struct anon_vma;
21
22#ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
23extern unsigned long max_mapnr;
24#endif
25
26extern unsigned long num_physpages;
27extern void * high_memory;
28extern unsigned long vmalloc_earlyreserve;
29extern int page_cluster;
30
31#ifdef CONFIG_SYSCTL
32extern int sysctl_legacy_va_layout;
33#else
34#define sysctl_legacy_va_layout 0
35#endif
36
37#include <asm/page.h>
38#include <asm/pgtable.h>
39#include <asm/processor.h>
40
41#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
42
43/*
44 * Linux kernel virtual memory manager primitives.
45 * The idea being to have a "virtual" mm in the same way
46 * we have a virtual fs - giving a cleaner interface to the
47 * mm details, and allowing different kinds of memory mappings
48 * (from shared memory to executable loading to arbitrary
49 * mmap() functions).
50 */
51
52/*
53 * This struct defines a memory VMM memory area. There is one of these
54 * per VM-area/task.  A VM area is any part of the process virtual memory
55 * space that has a special rule for the page-fault handlers (ie a shared
56 * library, the executable area etc).
57 */
58struct vm_area_struct {
59	struct mm_struct * vm_mm;	/* The address space we belong to. */
60	unsigned long vm_start;		/* Our start address within vm_mm. */
61	unsigned long vm_end;		/* The first byte after our end address
62					   within vm_mm. */
63
64	/* linked list of VM areas per task, sorted by address */
65	struct vm_area_struct *vm_next;
66
67	pgprot_t vm_page_prot;		/* Access permissions of this VMA. */
68	unsigned long vm_flags;		/* Flags, listed below. */
69
70	struct rb_node vm_rb;
71
72	/*
73	 * For areas with an address space and backing store,
74	 * linkage into the address_space->i_mmap prio tree, or
75	 * linkage to the list of like vmas hanging off its node, or
76	 * linkage of vma in the address_space->i_mmap_nonlinear list.
77	 */
78	union {
79		struct {
80			struct list_head list;
81			void *parent;	/* aligns with prio_tree_node parent */
82			struct vm_area_struct *head;
83		} vm_set;
84
85		struct raw_prio_tree_node prio_tree_node;
86	} shared;
87
88	/*
89	 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
90	 * list, after a COW of one of the file pages.  A MAP_SHARED vma
91	 * can only be in the i_mmap tree.  An anonymous MAP_PRIVATE, stack
92	 * or brk vma (with NULL file) can only be in an anon_vma list.
93	 */
94	struct list_head anon_vma_node;	/* Serialized by anon_vma->lock */
95	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
96
97	/* Function pointers to deal with this struct. */
98	struct vm_operations_struct * vm_ops;
99
100	/* Information about our backing store: */
101	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
102					   units, *not* PAGE_CACHE_SIZE */
103	struct file * vm_file;		/* File we map to (can be NULL). */
104	void * vm_private_data;		/* was vm_pte (shared mem) */
105	unsigned long vm_truncate_count;/* truncate_count or restart_addr */
106
107#ifndef CONFIG_MMU
108	atomic_t vm_usage;		/* refcount (VMAs shared if !MMU) */
109#endif
110#ifdef CONFIG_NUMA
111	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
112#endif
113};
114
115/*
116 * This struct defines the per-mm list of VMAs for uClinux. If CONFIG_MMU is
117 * disabled, then there's a single shared list of VMAs maintained by the
118 * system, and mm's subscribe to these individually
119 */
120struct vm_list_struct {
121	struct vm_list_struct	*next;
122	struct vm_area_struct	*vma;
123};
124
125#ifndef CONFIG_MMU
126extern struct rb_root nommu_vma_tree;
127extern struct rw_semaphore nommu_vma_sem;
128
129extern unsigned int kobjsize(const void *objp);
130#endif
131
132/*
133 * vm_flags..
134 */
135#define VM_READ		0x00000001	/* currently active flags */
136#define VM_WRITE	0x00000002
137#define VM_EXEC		0x00000004
138#define VM_SHARED	0x00000008
139
140/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
141#define VM_MAYREAD	0x00000010	/* limits for mprotect() etc */
142#define VM_MAYWRITE	0x00000020
143#define VM_MAYEXEC	0x00000040
144#define VM_MAYSHARE	0x00000080
145
146#define VM_GROWSDOWN	0x00000100	/* general info on the segment */
147#define VM_GROWSUP	0x00000200
148#define VM_PFNMAP	0x00000400	/* Page-ranges managed without "struct page", just pure PFN */
149#define VM_DENYWRITE	0x00000800	/* ETXTBSY on write attempts.. */
150
151#define VM_EXECUTABLE	0x00001000
152#define VM_LOCKED	0x00002000
153#define VM_IO           0x00004000	/* Memory mapped I/O or similar */
154
155					/* Used by sys_madvise() */
156#define VM_SEQ_READ	0x00008000	/* App will access data sequentially */
157#define VM_RAND_READ	0x00010000	/* App will not benefit from clustered reads */
158
159#define VM_DONTCOPY	0x00020000      /* Do not copy this vma on fork */
160#define VM_DONTEXPAND	0x00040000	/* Cannot expand with mremap() */
161#define VM_RESERVED	0x00080000	/* Count as reserved_vm like IO */
162#define VM_ACCOUNT	0x00100000	/* Is a VM accounted object */
163#define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */
164#define VM_NONLINEAR	0x00800000	/* Is non-linear (remap_file_pages) */
165#define VM_MAPPED_COPY	0x01000000	/* T if mapped copy of data (nommu mmap) */
166#define VM_INSERTPAGE	0x02000000	/* The vma has had "vm_insert_page()" done on it */
167
168#ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
169#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
170#endif
171
172#ifdef CONFIG_STACK_GROWSUP
173#define VM_STACK_FLAGS	(VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
174#else
175#define VM_STACK_FLAGS	(VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
176#endif
177
178#define VM_READHINTMASK			(VM_SEQ_READ | VM_RAND_READ)
179#define VM_ClearReadHint(v)		(v)->vm_flags &= ~VM_READHINTMASK
180#define VM_NormalReadHint(v)		(!((v)->vm_flags & VM_READHINTMASK))
181#define VM_SequentialReadHint(v)	((v)->vm_flags & VM_SEQ_READ)
182#define VM_RandomReadHint(v)		((v)->vm_flags & VM_RAND_READ)
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
191/*
192 * These are the virtual MM functions - opening of an area, closing and
193 * unmapping it (needed to keep files on disk up-to-date etc), pointer
194 * to the functions called when a no-page or a wp-page exception occurs.
195 */
196struct vm_operations_struct {
197	void (*open)(struct vm_area_struct * area);
198	void (*close)(struct vm_area_struct * area);
199	struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int *type);
200	int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
201
202	/* notification that a previously read-only page is about to become
203	 * writable, if an error is returned it will cause a SIGBUS */
204	int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page);
205#ifdef CONFIG_NUMA
206	int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
207	struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
208					unsigned long addr);
209	int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
210		const nodemask_t *to, unsigned long flags);
211#endif
212};
213
214struct mmu_gather;
215struct inode;
216
217/*
218 * Each physical page in the system has a struct page associated with
219 * it to keep track of whatever it is we are using the page for at the
220 * moment. Note that we have no way to track which tasks are using
221 * a page.
222 */
223struct page {
224	unsigned long flags;		/* Atomic flags, some possibly
225					 * updated asynchronously */
226	atomic_t _count;		/* Usage count, see below. */
227	atomic_t _mapcount;		/* Count of ptes mapped in mms,
228					 * to show when page is mapped
229					 * & limit reverse map searches.
230					 */
231	union {
232	    struct {
233		unsigned long private;		/* Mapping-private opaque data:
234					 	 * usually used for buffer_heads
235						 * if PagePrivate set; used for
236						 * swp_entry_t if PageSwapCache;
237						 * indicates order in the buddy
238						 * system if PG_buddy is set.
239						 */
240		struct address_space *mapping;	/* If low bit clear, points to
241						 * inode address_space, or NULL.
242						 * If page mapped as anonymous
243						 * memory, low bit is set, and
244						 * it points to anon_vma object:
245						 * see PAGE_MAPPING_ANON below.
246						 */
247	    };
248#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
249	    spinlock_t ptl;
250#endif
251	};
252	pgoff_t index;			/* Our offset within mapping. */
253	struct list_head lru;		/* Pageout list, eg. active_list
254					 * protected by zone->lru_lock !
255					 */
256	/*
257	 * On machines where all RAM is mapped into kernel address space,
258	 * we can simply calculate the virtual address. On machines with
259	 * highmem some memory is mapped into kernel virtual memory
260	 * dynamically, so we need a place to store that address.
261	 * Note that this field could be 16 bits on x86 ... ;)
262	 *
263	 * Architectures with slow multiplication can define
264	 * WANT_PAGE_VIRTUAL in asm/page.h
265	 */
266#if defined(WANT_PAGE_VIRTUAL)
267	void *virtual;			/* Kernel virtual address (NULL if
268					   not kmapped, ie. highmem) */
269#endif /* WANT_PAGE_VIRTUAL */
270};
271
272#define page_private(page)		((page)->private)
273#define set_page_private(page, v)	((page)->private = (v))
274
275/*
276 * FIXME: take this include out, include page-flags.h in
277 * files which need it (119 of them)
278 */
279#include <linux/page-flags.h>
280
281/*
282 * Methods to modify the page usage count.
283 *
284 * What counts for a page usage:
285 * - cache mapping   (page->mapping)
286 * - private data    (page->private)
287 * - page mapped in a task's page tables, each mapping
288 *   is counted separately
289 *
290 * Also, many kernel routines increase the page count before a critical
291 * routine so they can be sure the page doesn't go away from under them.
292 */
293
294/*
295 * Drop a ref, return true if the logical refcount fell to zero (the page has
296 * no users)
297 */
298static inline int put_page_testzero(struct page *page)
299{
300	BUG_ON(atomic_read(&page->_count) == 0);
301	return atomic_dec_and_test(&page->_count);
302}
303
304/*
305 * Try to grab a ref unless the page has a refcount of zero, return false if
306 * that is the case.
307 */
308static inline int get_page_unless_zero(struct page *page)
309{
310	return atomic_inc_not_zero(&page->_count);
311}
312
313extern void FASTCALL(__page_cache_release(struct page *));
314
315static inline int page_count(struct page *page)
316{
317	if (unlikely(PageCompound(page)))
318		page = (struct page *)page_private(page);
319	return atomic_read(&page->_count);
320}
321
322static inline void get_page(struct page *page)
323{
324	if (unlikely(PageCompound(page)))
325		page = (struct page *)page_private(page);
326	atomic_inc(&page->_count);
327}
328
329/*
330 * Setup the page count before being freed into the page allocator for
331 * the first time (boot or memory hotplug)
332 */
333static inline void init_page_count(struct page *page)
334{
335	atomic_set(&page->_count, 1);
336}
337
338void put_page(struct page *page);
339void put_pages_list(struct list_head *pages);
340
341void split_page(struct page *page, unsigned int order);
342
343/*
344 * Multiple processes may "see" the same page. E.g. for untouched
345 * mappings of /dev/null, all processes see the same page full of
346 * zeroes, and text pages of executables and shared libraries have
347 * only one copy in memory, at most, normally.
348 *
349 * For the non-reserved pages, page_count(page) denotes a reference count.
350 *   page_count() == 0 means the page is free. page->lru is then used for
351 *   freelist management in the buddy allocator.
352 *   page_count() == 1 means the page is used for exactly one purpose
353 *   (e.g. a private data page of one process).
354 *
355 * A page may be used for kmalloc() or anyone else who does a
356 * __get_free_page(). In this case the page_count() is at least 1, and
357 * all other fields are unused but should be 0 or NULL. The
358 * management of this page is the responsibility of the one who uses
359 * it.
360 *
361 * The other pages (we may call them "process pages") are completely
362 * managed by the Linux memory manager: I/O, buffers, swapping etc.
363 * The following discussion applies only to them.
364 *
365 * A page may belong to an inode's memory mapping. In this case,
366 * page->mapping is the pointer to the inode, and page->index is the
367 * file offset of the page, in units of PAGE_CACHE_SIZE.
368 *
369 * A page contains an opaque `private' member, which belongs to the
370 * page's address_space.  Usually, this is the address of a circular
371 * list of the page's disk buffers.
372 *
373 * For pages belonging to inodes, the page_count() is the number of
374 * attaches, plus 1 if `private' contains something, plus one for
375 * the page cache itself.
376 *
377 * Instead of keeping dirty/clean pages in per address-space lists, we instead
378 * now tag pages as dirty/under writeback in the radix tree.
379 *
380 * There is also a per-mapping radix tree mapping index to the page
381 * in memory if present. The tree is rooted at mapping->root.
382 *
383 * All process pages can do I/O:
384 * - inode pages may need to be read from disk,
385 * - inode pages which have been modified and are MAP_SHARED may need
386 *   to be written to disk,
387 * - private pages which have been modified may need to be swapped out
388 *   to swap space and (later) to be read back into memory.
389 */
390
391/*
392 * The zone field is never updated after free_area_init_core()
393 * sets it, so none of the operations on it need to be atomic.
394 */
395
396
397/*
398 * page->flags layout:
399 *
400 * There are three possibilities for how page->flags get
401 * laid out.  The first is for the normal case, without
402 * sparsemem.  The second is for sparsemem when there is
403 * plenty of space for node and section.  The last is when
404 * we have run out of space and have to fall back to an
405 * alternate (slower) way of determining the node.
406 *
407 *        No sparsemem: |       NODE     | ZONE | ... | FLAGS |
408 * with space for node: | SECTION | NODE | ZONE | ... | FLAGS |
409 *   no space for node: | SECTION |     ZONE    | ... | FLAGS |
410 */
411#ifdef CONFIG_SPARSEMEM
412#define SECTIONS_WIDTH		SECTIONS_SHIFT
413#else
414#define SECTIONS_WIDTH		0
415#endif
416
417#define ZONES_WIDTH		ZONES_SHIFT
418
419#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED
420#define NODES_WIDTH		NODES_SHIFT
421#else
422#define NODES_WIDTH		0
423#endif
424
425/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
426#define SECTIONS_PGOFF		((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
427#define NODES_PGOFF		(SECTIONS_PGOFF - NODES_WIDTH)
428#define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
429
430/*
431 * We are going to use the flags for the page to node mapping if its in
432 * there.  This includes the case where there is no node, so it is implicit.
433 */
434#define FLAGS_HAS_NODE		(NODES_WIDTH > 0 || NODES_SHIFT == 0)
435
436#ifndef PFN_SECTION_SHIFT
437#define PFN_SECTION_SHIFT 0
438#endif
439
440/*
441 * Define the bit shifts to access each section.  For non-existant
442 * sections we define the shift as 0; that plus a 0 mask ensures
443 * the compiler will optimise away reference to them.
444 */
445#define SECTIONS_PGSHIFT	(SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
446#define NODES_PGSHIFT		(NODES_PGOFF * (NODES_WIDTH != 0))
447#define ZONES_PGSHIFT		(ZONES_PGOFF * (ZONES_WIDTH != 0))
448
449/* NODE:ZONE or SECTION:ZONE is used to lookup the zone from a page. */
450#if FLAGS_HAS_NODE
451#define ZONETABLE_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
452#else
453#define ZONETABLE_SHIFT		(SECTIONS_SHIFT + ZONES_SHIFT)
454#endif
455#define ZONETABLE_PGSHIFT	ZONES_PGSHIFT
456
457#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
458#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
459#endif
460
461#define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
462#define NODES_MASK		((1UL << NODES_WIDTH) - 1)
463#define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
464#define ZONETABLE_MASK		((1UL << ZONETABLE_SHIFT) - 1)
465
466static inline unsigned long page_zonenum(struct page *page)
467{
468	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
469}
470
471struct zone;
472extern struct zone *zone_table[];
473
474static inline int page_zone_id(struct page *page)
475{
476	return (page->flags >> ZONETABLE_PGSHIFT) & ZONETABLE_MASK;
477}
478static inline struct zone *page_zone(struct page *page)
479{
480	return zone_table[page_zone_id(page)];
481}
482
483static inline unsigned long page_to_nid(struct page *page)
484{
485	if (FLAGS_HAS_NODE)
486		return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
487	else
488		return page_zone(page)->zone_pgdat->node_id;
489}
490static inline unsigned long page_to_section(struct page *page)
491{
492	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
493}
494
495static inline void set_page_zone(struct page *page, unsigned long zone)
496{
497	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
498	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
499}
500static inline void set_page_node(struct page *page, unsigned long node)
501{
502	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
503	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
504}
505static inline void set_page_section(struct page *page, unsigned long section)
506{
507	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
508	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
509}
510
511static inline void set_page_links(struct page *page, unsigned long zone,
512	unsigned long node, unsigned long pfn)
513{
514	set_page_zone(page, zone);
515	set_page_node(page, node);
516	set_page_section(page, pfn_to_section_nr(pfn));
517}
518
519/*
520 * Some inline functions in vmstat.h depend on page_zone()
521 */
522#include <linux/vmstat.h>
523
524#ifndef CONFIG_DISCONTIGMEM
525/* The array of struct pages - for discontigmem use pgdat->lmem_map */
526extern struct page *mem_map;
527#endif
528
529static __always_inline void *lowmem_page_address(struct page *page)
530{
531	return __va(page_to_pfn(page) << PAGE_SHIFT);
532}
533
534#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
535#define HASHED_PAGE_VIRTUAL
536#endif
537
538#if defined(WANT_PAGE_VIRTUAL)
539#define page_address(page) ((page)->virtual)
540#define set_page_address(page, address)			\
541	do {						\
542		(page)->virtual = (address);		\
543	} while(0)
544#define page_address_init()  do { } while(0)
545#endif
546
547#if defined(HASHED_PAGE_VIRTUAL)
548void *page_address(struct page *page);
549void set_page_address(struct page *page, void *virtual);
550void page_address_init(void);
551#endif
552
553#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
554#define page_address(page) lowmem_page_address(page)
555#define set_page_address(page, address)  do { } while(0)
556#define page_address_init()  do { } while(0)
557#endif
558
559/*
560 * On an anonymous page mapped into a user virtual memory area,
561 * page->mapping points to its anon_vma, not to a struct address_space;
562 * with the PAGE_MAPPING_ANON bit set to distinguish it.
563 *
564 * Please note that, confusingly, "page_mapping" refers to the inode
565 * address_space which maps the page from disk; whereas "page_mapped"
566 * refers to user virtual address space into which the page is mapped.
567 */
568#define PAGE_MAPPING_ANON	1
569
570extern struct address_space swapper_space;
571static inline struct address_space *page_mapping(struct page *page)
572{
573	struct address_space *mapping = page->mapping;
574
575	if (unlikely(PageSwapCache(page)))
576		mapping = &swapper_space;
577	else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
578		mapping = NULL;
579	return mapping;
580}
581
582static inline int PageAnon(struct page *page)
583{
584	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
585}
586
587/*
588 * Return the pagecache index of the passed page.  Regular pagecache pages
589 * use ->index whereas swapcache pages use ->private
590 */
591static inline pgoff_t page_index(struct page *page)
592{
593	if (unlikely(PageSwapCache(page)))
594		return page_private(page);
595	return page->index;
596}
597
598/*
599 * The atomic page->_mapcount, like _count, starts from -1:
600 * so that transitions both from it and to it can be tracked,
601 * using atomic_inc_and_test and atomic_add_negative(-1).
602 */
603static inline void reset_page_mapcount(struct page *page)
604{
605	atomic_set(&(page)->_mapcount, -1);
606}
607
608static inline int page_mapcount(struct page *page)
609{
610	return atomic_read(&(page)->_mapcount) + 1;
611}
612
613/*
614 * Return true if this page is mapped into pagetables.
615 */
616static inline int page_mapped(struct page *page)
617{
618	return atomic_read(&(page)->_mapcount) >= 0;
619}
620
621/*
622 * Error return values for the *_nopage functions
623 */
624#define NOPAGE_SIGBUS	(NULL)
625#define NOPAGE_OOM	((struct page *) (-1))
626
627/*
628 * Different kinds of faults, as returned by handle_mm_fault().
629 * Used to decide whether a process gets delivered SIGBUS or
630 * just gets major/minor fault counters bumped up.
631 */
632#define VM_FAULT_OOM	0x00
633#define VM_FAULT_SIGBUS	0x01
634#define VM_FAULT_MINOR	0x02
635#define VM_FAULT_MAJOR	0x03
636
637/*
638 * Special case for get_user_pages.
639 * Must be in a distinct bit from the above VM_FAULT_ flags.
640 */
641#define VM_FAULT_WRITE	0x10
642
643#define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
644
645extern void show_free_areas(void);
646
647#ifdef CONFIG_SHMEM
648struct page *shmem_nopage(struct vm_area_struct *vma,
649			unsigned long address, int *type);
650int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new);
651struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
652					unsigned long addr);
653int shmem_lock(struct file *file, int lock, struct user_struct *user);
654#else
655#define shmem_nopage filemap_nopage
656
657static inline int shmem_lock(struct file *file, int lock,
658			     struct user_struct *user)
659{
660	return 0;
661}
662
663static inline int shmem_set_policy(struct vm_area_struct *vma,
664				   struct mempolicy *new)
665{
666	return 0;
667}
668
669static inline struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
670						 unsigned long addr)
671{
672	return NULL;
673}
674#endif
675struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
676extern int shmem_mmap(struct file *file, struct vm_area_struct *vma);
677
678int shmem_zero_setup(struct vm_area_struct *);
679
680#ifndef CONFIG_MMU
681extern unsigned long shmem_get_unmapped_area(struct file *file,
682					     unsigned long addr,
683					     unsigned long len,
684					     unsigned long pgoff,
685					     unsigned long flags);
686#endif
687
688static inline int can_do_mlock(void)
689{
690	if (capable(CAP_IPC_LOCK))
691		return 1;
692	if (current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
693		return 1;
694	return 0;
695}
696extern int user_shm_lock(size_t, struct user_struct *);
697extern void user_shm_unlock(size_t, struct user_struct *);
698
699/*
700 * Parameter block passed down to zap_pte_range in exceptional cases.
701 */
702struct zap_details {
703	struct vm_area_struct *nonlinear_vma;	/* Check page->index if set */
704	struct address_space *check_mapping;	/* Check page->mapping if set */
705	pgoff_t	first_index;			/* Lowest page->index to unmap */
706	pgoff_t last_index;			/* Highest page->index to unmap */
707	spinlock_t *i_mmap_lock;		/* For unmap_mapping_range: */
708	unsigned long truncate_count;		/* Compare vm_truncate_count */
709};
710
711struct page *vm_normal_page(struct vm_area_struct *, unsigned long, pte_t);
712unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
713		unsigned long size, struct zap_details *);
714unsigned long unmap_vmas(struct mmu_gather **tlb,
715		struct vm_area_struct *start_vma, unsigned long start_addr,
716		unsigned long end_addr, unsigned long *nr_accounted,
717		struct zap_details *);
718void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
719		unsigned long end, unsigned long floor, unsigned long ceiling);
720void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
721		unsigned long floor, unsigned long ceiling);
722int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
723			struct vm_area_struct *vma);
724int zeromap_page_range(struct vm_area_struct *vma, unsigned long from,
725			unsigned long size, pgprot_t prot);
726void unmap_mapping_range(struct address_space *mapping,
727		loff_t const holebegin, loff_t const holelen, int even_cows);
728
729static inline void unmap_shared_mapping_range(struct address_space *mapping,
730		loff_t const holebegin, loff_t const holelen)
731{
732	unmap_mapping_range(mapping, holebegin, holelen, 0);
733}
734
735extern int vmtruncate(struct inode * inode, loff_t offset);
736extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
737extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
738extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
739
740#ifdef CONFIG_MMU
741extern int __handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma,
742			unsigned long address, int write_access);
743
744static inline int handle_mm_fault(struct mm_struct *mm,
745			struct vm_area_struct *vma, unsigned long address,
746			int write_access)
747{
748	return __handle_mm_fault(mm, vma, address, write_access) &
749				(~VM_FAULT_WRITE);
750}
751#else
752static inline int handle_mm_fault(struct mm_struct *mm,
753			struct vm_area_struct *vma, unsigned long address,
754			int write_access)
755{
756	/* should never happen if there's no MMU */
757	BUG();
758	return VM_FAULT_SIGBUS;
759}
760#endif
761
762extern int make_pages_present(unsigned long addr, unsigned long end);
763extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
764void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
765
766int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
767		int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
768void print_bad_pte(struct vm_area_struct *, pte_t, unsigned long);
769
770int __set_page_dirty_buffers(struct page *page);
771int __set_page_dirty_nobuffers(struct page *page);
772int redirty_page_for_writepage(struct writeback_control *wbc,
773				struct page *page);
774int FASTCALL(set_page_dirty(struct page *page));
775int set_page_dirty_lock(struct page *page);
776int clear_page_dirty_for_io(struct page *page);
777
778extern unsigned long do_mremap(unsigned long addr,
779			       unsigned long old_len, unsigned long new_len,
780			       unsigned long flags, unsigned long new_addr);
781
782/*
783 * Prototype to add a shrinker callback for ageable caches.
784 *
785 * These functions are passed a count `nr_to_scan' and a gfpmask.  They should
786 * scan `nr_to_scan' objects, attempting to free them.
787 *
788 * The callback must return the number of objects which remain in the cache.
789 *
790 * The callback will be passed nr_to_scan == 0 when the VM is querying the
791 * cache size, so a fastpath for that case is appropriate.
792 */
793typedef int (*shrinker_t)(int nr_to_scan, gfp_t gfp_mask);
794
795/*
796 * Add an aging callback.  The int is the number of 'seeks' it takes
797 * to recreate one of the objects that these functions age.
798 */
799
800#define DEFAULT_SEEKS 2
801struct shrinker;
802extern struct shrinker *set_shrinker(int, shrinker_t);
803extern void remove_shrinker(struct shrinker *shrinker);
804
805extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
806
807int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
808int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
809int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
810int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
811
812/*
813 * The following ifdef needed to get the 4level-fixup.h header to work.
814 * Remove it when 4level-fixup.h has been removed.
815 */
816#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
817static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
818{
819	return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
820		NULL: pud_offset(pgd, address);
821}
822
823static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
824{
825	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
826		NULL: pmd_offset(pud, address);
827}
828#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
829
830#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
831/*
832 * We tuck a spinlock to guard each pagetable page into its struct page,
833 * at page->private, with BUILD_BUG_ON to make sure that this will not
834 * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
835 * When freeing, reset page->mapping so free_pages_check won't complain.
836 */
837#define __pte_lockptr(page)	&((page)->ptl)
838#define pte_lock_init(_page)	do {					\
839	spin_lock_init(__pte_lockptr(_page));				\
840} while (0)
841#define pte_lock_deinit(page)	((page)->mapping = NULL)
842#define pte_lockptr(mm, pmd)	({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
843#else
844/*
845 * We use mm->page_table_lock to guard all pagetable pages of the mm.
846 */
847#define pte_lock_init(page)	do {} while (0)
848#define pte_lock_deinit(page)	do {} while (0)
849#define pte_lockptr(mm, pmd)	({(void)(pmd); &(mm)->page_table_lock;})
850#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
851
852#define pte_offset_map_lock(mm, pmd, address, ptlp)	\
853({							\
854	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
855	pte_t *__pte = pte_offset_map(pmd, address);	\
856	*(ptlp) = __ptl;				\
857	spin_lock(__ptl);				\
858	__pte;						\
859})
860
861#define pte_unmap_unlock(pte, ptl)	do {		\
862	spin_unlock(ptl);				\
863	pte_unmap(pte);					\
864} while (0)
865
866#define pte_alloc_map(mm, pmd, address)			\
867	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
868		NULL: pte_offset_map(pmd, address))
869
870#define pte_alloc_map_lock(mm, pmd, address, ptlp)	\
871	((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
872		NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
873
874#define pte_alloc_kernel(pmd, address)			\
875	((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
876		NULL: pte_offset_kernel(pmd, address))
877
878extern void free_area_init(unsigned long * zones_size);
879extern void free_area_init_node(int nid, pg_data_t *pgdat,
880	unsigned long * zones_size, unsigned long zone_start_pfn,
881	unsigned long *zholes_size);
882extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
883extern void setup_per_zone_pages_min(void);
884extern void mem_init(void);
885extern void show_mem(void);
886extern void si_meminfo(struct sysinfo * val);
887extern void si_meminfo_node(struct sysinfo *val, int nid);
888
889#ifdef CONFIG_NUMA
890extern void setup_per_cpu_pageset(void);
891#else
892static inline void setup_per_cpu_pageset(void) {}
893#endif
894
895/* prio_tree.c */
896void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
897void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
898void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
899struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
900	struct prio_tree_iter *iter);
901
902#define vma_prio_tree_foreach(vma, iter, root, begin, end)	\
903	for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;	\
904		(vma = vma_prio_tree_next(vma, iter)); )
905
906static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
907					struct list_head *list)
908{
909	vma->shared.vm_set.parent = NULL;
910	list_add_tail(&vma->shared.vm_set.list, list);
911}
912
913/* mmap.c */
914extern int __vm_enough_memory(long pages, int cap_sys_admin);
915extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
916	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
917extern struct vm_area_struct *vma_merge(struct mm_struct *,
918	struct vm_area_struct *prev, unsigned long addr, unsigned long end,
919	unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
920	struct mempolicy *);
921extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
922extern int split_vma(struct mm_struct *,
923	struct vm_area_struct *, unsigned long addr, int new_below);
924extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
925extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
926	struct rb_node **, struct rb_node *);
927extern void unlink_file_vma(struct vm_area_struct *);
928extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
929	unsigned long addr, unsigned long len, pgoff_t pgoff);
930extern void exit_mmap(struct mm_struct *);
931extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
932
933extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
934
935extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
936	unsigned long len, unsigned long prot,
937	unsigned long flag, unsigned long pgoff);
938
939static inline unsigned long do_mmap(struct file *file, unsigned long addr,
940	unsigned long len, unsigned long prot,
941	unsigned long flag, unsigned long offset)
942{
943	unsigned long ret = -EINVAL;
944	if ((offset + PAGE_ALIGN(len)) < offset)
945		goto out;
946	if (!(offset & ~PAGE_MASK))
947		ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
948out:
949	return ret;
950}
951
952extern int do_munmap(struct mm_struct *, unsigned long, size_t);
953
954extern unsigned long do_brk(unsigned long, unsigned long);
955
956/* filemap.c */
957extern unsigned long page_unuse(struct page *);
958extern void truncate_inode_pages(struct address_space *, loff_t);
959extern void truncate_inode_pages_range(struct address_space *,
960				       loff_t lstart, loff_t lend);
961
962/* generic vm_area_ops exported for stackable file systems */
963extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
964extern int filemap_populate(struct vm_area_struct *, unsigned long,
965		unsigned long, pgprot_t, unsigned long, int);
966
967/* mm/page-writeback.c */
968int write_one_page(struct page *page, int wait);
969
970/* readahead.c */
971#define VM_MAX_READAHEAD	128	/* kbytes */
972#define VM_MIN_READAHEAD	16	/* kbytes (includes current page) */
973#define VM_MAX_CACHE_HIT    	256	/* max pages in a row in cache before
974					 * turning readahead off */
975
976int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
977			pgoff_t offset, unsigned long nr_to_read);
978int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
979			pgoff_t offset, unsigned long nr_to_read);
980unsigned long page_cache_readahead(struct address_space *mapping,
981			  struct file_ra_state *ra,
982			  struct file *filp,
983			  pgoff_t offset,
984			  unsigned long size);
985void handle_ra_miss(struct address_space *mapping,
986		    struct file_ra_state *ra, pgoff_t offset);
987unsigned long max_sane_readahead(unsigned long nr);
988
989/* Do stack extension */
990extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
991#ifdef CONFIG_IA64
992extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
993#endif
994
995/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
996extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
997extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
998					     struct vm_area_struct **pprev);
999
1000/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1001   NULL if none.  Assume start_addr < end_addr. */
1002static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1003{
1004	struct vm_area_struct * vma = find_vma(mm,start_addr);
1005
1006	if (vma && end_addr <= vma->vm_start)
1007		vma = NULL;
1008	return vma;
1009}
1010
1011static inline unsigned long vma_pages(struct vm_area_struct *vma)
1012{
1013	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1014}
1015
1016struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1017struct page *vmalloc_to_page(void *addr);
1018unsigned long vmalloc_to_pfn(void *addr);
1019int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1020			unsigned long pfn, unsigned long size, pgprot_t);
1021int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1022
1023struct page *follow_page(struct vm_area_struct *, unsigned long address,
1024			unsigned int foll_flags);
1025#define FOLL_WRITE	0x01	/* check pte is writable */
1026#define FOLL_TOUCH	0x02	/* mark page accessed */
1027#define FOLL_GET	0x04	/* do get_page on page */
1028#define FOLL_ANON	0x08	/* give ZERO_PAGE if no pgtable */
1029
1030#ifdef CONFIG_PROC_FS
1031void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1032#else
1033static inline void vm_stat_account(struct mm_struct *mm,
1034			unsigned long flags, struct file *file, long pages)
1035{
1036}
1037#endif /* CONFIG_PROC_FS */
1038
1039#ifndef CONFIG_DEBUG_PAGEALLOC
1040static inline void
1041kernel_map_pages(struct page *page, int numpages, int enable)
1042{
1043	if (!PageHighMem(page) && !enable)
1044		debug_check_no_locks_freed(page_address(page),
1045					   numpages * PAGE_SIZE);
1046}
1047#endif
1048
1049extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1050#ifdef	__HAVE_ARCH_GATE_AREA
1051int in_gate_area_no_task(unsigned long addr);
1052int in_gate_area(struct task_struct *task, unsigned long addr);
1053#else
1054int in_gate_area_no_task(unsigned long addr);
1055#define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1056#endif	/* __HAVE_ARCH_GATE_AREA */
1057
1058/* /proc/<pid>/oom_adj set to -17 protects from the oom-killer */
1059#define OOM_DISABLE -17
1060
1061int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *,
1062					void __user *, size_t *, loff_t *);
1063unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1064			unsigned long lru_pages);
1065void drop_pagecache(void);
1066void drop_slab(void);
1067
1068#ifndef CONFIG_MMU
1069#define randomize_va_space 0
1070#else
1071extern int randomize_va_space;
1072#endif
1073
1074const char *arch_vma_name(struct vm_area_struct *vma);
1075
1076#endif /* __KERNEL__ */
1077#endif /* _LINUX_MM_H */
1078