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
19 struct mempolicy;
20 struct anon_vma;
21
22 #ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */
23 extern unsigned long max_mapnr;
24 #endif
25
26 extern unsigned long num_physpages;
27 extern void * high_memory;
28 extern unsigned long vmalloc_earlyreserve;
29 extern int page_cluster;
30
31 #ifdef CONFIG_SYSCTL
32 extern 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 */
58 struct 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 */
120 struct vm_list_struct {
121 struct vm_list_struct *next;
122 struct vm_area_struct *vma;
123 };
124
125 #ifndef CONFIG_MMU
126 extern struct rb_root nommu_vma_tree;
127 extern struct rw_semaphore nommu_vma_sem;
128
129 extern 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 */
188 extern 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 */
196 struct 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
214 struct mmu_gather;
215 struct 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 */
223 struct 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 */
put_page_testzero(struct page * page)298 static 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 */
get_page_unless_zero(struct page * page)308 static inline int get_page_unless_zero(struct page *page)
309 {
310 return atomic_inc_not_zero(&page->_count);
311 }
312
313 extern void FASTCALL(__page_cache_release(struct page *));
314
page_count(struct page * page)315 static 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
get_page(struct page * page)322 static 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 */
init_page_count(struct page * page)333 static inline void init_page_count(struct page *page)
334 {
335 atomic_set(&page->_count, 1);
336 }
337
338 void put_page(struct page *page);
339 void put_pages_list(struct list_head *pages);
340
341 void 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
page_zonenum(struct page * page)466 static inline unsigned long page_zonenum(struct page *page)
467 {
468 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
469 }
470
471 struct zone;
472 extern struct zone *zone_table[];
473
page_zone_id(struct page * page)474 static inline int page_zone_id(struct page *page)
475 {
476 return (page->flags >> ZONETABLE_PGSHIFT) & ZONETABLE_MASK;
477 }
page_zone(struct page * page)478 static inline struct zone *page_zone(struct page *page)
479 {
480 return zone_table[page_zone_id(page)];
481 }
482
page_to_nid(struct page * page)483 static 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 }
page_to_section(struct page * page)490 static inline unsigned long page_to_section(struct page *page)
491 {
492 return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
493 }
494
set_page_zone(struct page * page,unsigned long zone)495 static 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 }
set_page_node(struct page * page,unsigned long node)500 static 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 }
set_page_section(struct page * page,unsigned long section)505 static 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
set_page_links(struct page * page,unsigned long zone,unsigned long node,unsigned long pfn)511 static 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 */
526 extern struct page *mem_map;
527 #endif
528
lowmem_page_address(struct page * page)529 static __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)
548 void *page_address(struct page *page);
549 void set_page_address(struct page *page, void *virtual);
550 void 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
570 extern struct address_space swapper_space;
page_mapping(struct page * page)571 static 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
PageAnon(struct page * page)582 static 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 */
page_index(struct page * page)591 static 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 */
reset_page_mapcount(struct page * page)603 static inline void reset_page_mapcount(struct page *page)
604 {
605 atomic_set(&(page)->_mapcount, -1);
606 }
607
page_mapcount(struct page * page)608 static 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 */
page_mapped(struct page * page)616 static 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
645 extern void show_free_areas(void);
646
647 #ifdef CONFIG_SHMEM
648 struct page *shmem_nopage(struct vm_area_struct *vma,
649 unsigned long address, int *type);
650 int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new);
651 struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
652 unsigned long addr);
653 int shmem_lock(struct file *file, int lock, struct user_struct *user);
654 #else
655 #define shmem_nopage filemap_nopage
656
shmem_lock(struct file * file,int lock,struct user_struct * user)657 static inline int shmem_lock(struct file *file, int lock,
658 struct user_struct *user)
659 {
660 return 0;
661 }
662
shmem_set_policy(struct vm_area_struct * vma,struct mempolicy * new)663 static inline int shmem_set_policy(struct vm_area_struct *vma,
664 struct mempolicy *new)
665 {
666 return 0;
667 }
668
shmem_get_policy(struct vm_area_struct * vma,unsigned long addr)669 static inline struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
670 unsigned long addr)
671 {
672 return NULL;
673 }
674 #endif
675 struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
676 extern int shmem_mmap(struct file *file, struct vm_area_struct *vma);
677
678 int shmem_zero_setup(struct vm_area_struct *);
679
680 #ifndef CONFIG_MMU
681 extern 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
can_do_mlock(void)688 static 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 }
696 extern int user_shm_lock(size_t, struct user_struct *);
697 extern void user_shm_unlock(size_t, struct user_struct *);
698
699 /*
700 * Parameter block passed down to zap_pte_range in exceptional cases.
701 */
702 struct 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
711 struct page *vm_normal_page(struct vm_area_struct *, unsigned long, pte_t);
712 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
713 unsigned long size, struct zap_details *);
714 unsigned 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 *);
718 void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
719 unsigned long end, unsigned long floor, unsigned long ceiling);
720 void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
721 unsigned long floor, unsigned long ceiling);
722 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
723 struct vm_area_struct *vma);
724 int zeromap_page_range(struct vm_area_struct *vma, unsigned long from,
725 unsigned long size, pgprot_t prot);
726 void unmap_mapping_range(struct address_space *mapping,
727 loff_t const holebegin, loff_t const holelen, int even_cows);
728
unmap_shared_mapping_range(struct address_space * mapping,loff_t const holebegin,loff_t const holelen)729 static 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
735 extern int vmtruncate(struct inode * inode, loff_t offset);
736 extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
737 extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
738 extern 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
741 extern int __handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma,
742 unsigned long address, int write_access);
743
handle_mm_fault(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long address,int write_access)744 static 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
handle_mm_fault(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long address,int write_access)752 static 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
762 extern int make_pages_present(unsigned long addr, unsigned long end);
763 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
764 void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
765
766 int 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);
768 void print_bad_pte(struct vm_area_struct *, pte_t, unsigned long);
769
770 int __set_page_dirty_buffers(struct page *page);
771 int __set_page_dirty_nobuffers(struct page *page);
772 int redirty_page_for_writepage(struct writeback_control *wbc,
773 struct page *page);
774 int FASTCALL(set_page_dirty(struct page *page));
775 int set_page_dirty_lock(struct page *page);
776 int clear_page_dirty_for_io(struct page *page);
777
778 extern 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 */
793 typedef 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
801 struct shrinker;
802 extern struct shrinker *set_shrinker(int, shrinker_t);
803 extern void remove_shrinker(struct shrinker *shrinker);
804
805 extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
806
807 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
808 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
809 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
810 int __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)
pud_alloc(struct mm_struct * mm,pgd_t * pgd,unsigned long address)817 static 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
pmd_alloc(struct mm_struct * mm,pud_t * pud,unsigned long address)823 static 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
878 extern void free_area_init(unsigned long * zones_size);
879 extern 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);
882 extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
883 extern void setup_per_zone_pages_min(void);
884 extern void mem_init(void);
885 extern void show_mem(void);
886 extern void si_meminfo(struct sysinfo * val);
887 extern void si_meminfo_node(struct sysinfo *val, int nid);
888
889 #ifdef CONFIG_NUMA
890 extern void setup_per_cpu_pageset(void);
891 #else
setup_per_cpu_pageset(void)892 static inline void setup_per_cpu_pageset(void) {}
893 #endif
894
895 /* prio_tree.c */
896 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
897 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
898 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
899 struct 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
vma_nonlinear_insert(struct vm_area_struct * vma,struct list_head * list)906 static 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 */
914 extern int __vm_enough_memory(long pages, int cap_sys_admin);
915 extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
916 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
917 extern 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 *);
921 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
922 extern int split_vma(struct mm_struct *,
923 struct vm_area_struct *, unsigned long addr, int new_below);
924 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
925 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
926 struct rb_node **, struct rb_node *);
927 extern void unlink_file_vma(struct vm_area_struct *);
928 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
929 unsigned long addr, unsigned long len, pgoff_t pgoff);
930 extern void exit_mmap(struct mm_struct *);
931 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
932
933 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
934
935 extern 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
do_mmap(struct file * file,unsigned long addr,unsigned long len,unsigned long prot,unsigned long flag,unsigned long offset)939 static 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);
948 out:
949 return ret;
950 }
951
952 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
953
954 extern unsigned long do_brk(unsigned long, unsigned long);
955
956 /* filemap.c */
957 extern unsigned long page_unuse(struct page *);
958 extern void truncate_inode_pages(struct address_space *, loff_t);
959 extern 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 */
963 extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
964 extern int filemap_populate(struct vm_area_struct *, unsigned long,
965 unsigned long, pgprot_t, unsigned long, int);
966
967 /* mm/page-writeback.c */
968 int 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
976 int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
977 pgoff_t offset, unsigned long nr_to_read);
978 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
979 pgoff_t offset, unsigned long nr_to_read);
980 unsigned 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);
985 void handle_ra_miss(struct address_space *mapping,
986 struct file_ra_state *ra, pgoff_t offset);
987 unsigned long max_sane_readahead(unsigned long nr);
988
989 /* Do stack extension */
990 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
991 #ifdef CONFIG_IA64
992 extern 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. */
996 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
997 extern 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. */
find_vma_intersection(struct mm_struct * mm,unsigned long start_addr,unsigned long end_addr)1002 static 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
vma_pages(struct vm_area_struct * vma)1011 static inline unsigned long vma_pages(struct vm_area_struct *vma)
1012 {
1013 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1014 }
1015
1016 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1017 struct page *vmalloc_to_page(void *addr);
1018 unsigned long vmalloc_to_pfn(void *addr);
1019 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1020 unsigned long pfn, unsigned long size, pgprot_t);
1021 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1022
1023 struct 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
1031 void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1032 #else
vm_stat_account(struct mm_struct * mm,unsigned long flags,struct file * file,long pages)1033 static 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
1040 static inline void
kernel_map_pages(struct page * page,int numpages,int enable)1041 kernel_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
1049 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1050 #ifdef __HAVE_ARCH_GATE_AREA
1051 int in_gate_area_no_task(unsigned long addr);
1052 int in_gate_area(struct task_struct *task, unsigned long addr);
1053 #else
1054 int 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
1061 int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *,
1062 void __user *, size_t *, loff_t *);
1063 unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1064 unsigned long lru_pages);
1065 void drop_pagecache(void);
1066 void drop_slab(void);
1067
1068 #ifndef CONFIG_MMU
1069 #define randomize_va_space 0
1070 #else
1071 extern int randomize_va_space;
1072 #endif
1073
1074 const char *arch_vma_name(struct vm_area_struct *vma);
1075
1076 #endif /* __KERNEL__ */
1077 #endif /* _LINUX_MM_H */
1078