~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/power/snapshot.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * linux/kernel/power/snapshot.c
  3  *
  4  * This file provides system snapshot/restore functionality for swsusp.
  5  *
  6  * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
  7  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
  8  *
  9  * This file is released under the GPLv2.
 10  *
 11  */
 12 
 13 #include <linux/version.h>
 14 #include <linux/module.h>
 15 #include <linux/mm.h>
 16 #include <linux/suspend.h>
 17 #include <linux/delay.h>
 18 #include <linux/bitops.h>
 19 #include <linux/spinlock.h>
 20 #include <linux/kernel.h>
 21 #include <linux/pm.h>
 22 #include <linux/device.h>
 23 #include <linux/init.h>
 24 #include <linux/bootmem.h>
 25 #include <linux/syscalls.h>
 26 #include <linux/console.h>
 27 #include <linux/highmem.h>
 28 #include <linux/list.h>
 29 #include <linux/slab.h>
 30 
 31 #include <asm/uaccess.h>
 32 #include <asm/mmu_context.h>
 33 #include <asm/pgtable.h>
 34 #include <asm/tlbflush.h>
 35 #include <asm/io.h>
 36 
 37 #include "power.h"
 38 
 39 static int swsusp_page_is_free(struct page *);
 40 static void swsusp_set_page_forbidden(struct page *);
 41 static void swsusp_unset_page_forbidden(struct page *);
 42 
 43 /*
 44  * Number of bytes to reserve for memory allocations made by device drivers
 45  * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
 46  * cause image creation to fail (tunable via /sys/power/reserved_size).
 47  */
 48 unsigned long reserved_size;
 49 
 50 void __init hibernate_reserved_size_init(void)
 51 {
 52         reserved_size = SPARE_PAGES * PAGE_SIZE;
 53 }
 54 
 55 /*
 56  * Preferred image size in bytes (tunable via /sys/power/image_size).
 57  * When it is set to N, swsusp will do its best to ensure the image
 58  * size will not exceed N bytes, but if that is impossible, it will
 59  * try to create the smallest image possible.
 60  */
 61 unsigned long image_size;
 62 
 63 void __init hibernate_image_size_init(void)
 64 {
 65         image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE;
 66 }
 67 
 68 /* List of PBEs needed for restoring the pages that were allocated before
 69  * the suspend and included in the suspend image, but have also been
 70  * allocated by the "resume" kernel, so their contents cannot be written
 71  * directly to their "original" page frames.
 72  */
 73 struct pbe *restore_pblist;
 74 
 75 /* Pointer to an auxiliary buffer (1 page) */
 76 static void *buffer;
 77 
 78 /**
 79  *      @safe_needed - on resume, for storing the PBE list and the image,
 80  *      we can only use memory pages that do not conflict with the pages
 81  *      used before suspend.  The unsafe pages have PageNosaveFree set
 82  *      and we count them using unsafe_pages.
 83  *
 84  *      Each allocated image page is marked as PageNosave and PageNosaveFree
 85  *      so that swsusp_free() can release it.
 86  */
 87 
 88 #define PG_ANY          0
 89 #define PG_SAFE         1
 90 #define PG_UNSAFE_CLEAR 1
 91 #define PG_UNSAFE_KEEP  0
 92 
 93 static unsigned int allocated_unsafe_pages;
 94 
 95 static void *get_image_page(gfp_t gfp_mask, int safe_needed)
 96 {
 97         void *res;
 98 
 99         res = (void *)get_zeroed_page(gfp_mask);
100         if (safe_needed)
101                 while (res && swsusp_page_is_free(virt_to_page(res))) {
102                         /* The page is unsafe, mark it for swsusp_free() */
103                         swsusp_set_page_forbidden(virt_to_page(res));
104                         allocated_unsafe_pages++;
105                         res = (void *)get_zeroed_page(gfp_mask);
106                 }
107         if (res) {
108                 swsusp_set_page_forbidden(virt_to_page(res));
109                 swsusp_set_page_free(virt_to_page(res));
110         }
111         return res;
112 }
113 
114 unsigned long get_safe_page(gfp_t gfp_mask)
115 {
116         return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
117 }
118 
119 static struct page *alloc_image_page(gfp_t gfp_mask)
120 {
121         struct page *page;
122 
123         page = alloc_page(gfp_mask);
124         if (page) {
125                 swsusp_set_page_forbidden(page);
126                 swsusp_set_page_free(page);
127         }
128         return page;
129 }
130 
131 /**
132  *      free_image_page - free page represented by @addr, allocated with
133  *      get_image_page (page flags set by it must be cleared)
134  */
135 
136 static inline void free_image_page(void *addr, int clear_nosave_free)
137 {
138         struct page *page;
139 
140         BUG_ON(!virt_addr_valid(addr));
141 
142         page = virt_to_page(addr);
143 
144         swsusp_unset_page_forbidden(page);
145         if (clear_nosave_free)
146                 swsusp_unset_page_free(page);
147 
148         __free_page(page);
149 }
150 
151 /* struct linked_page is used to build chains of pages */
152 
153 #define LINKED_PAGE_DATA_SIZE   (PAGE_SIZE - sizeof(void *))
154 
155 struct linked_page {
156         struct linked_page *next;
157         char data[LINKED_PAGE_DATA_SIZE];
158 } __attribute__((packed));
159 
160 static inline void
161 free_list_of_pages(struct linked_page *list, int clear_page_nosave)
162 {
163         while (list) {
164                 struct linked_page *lp = list->next;
165 
166                 free_image_page(list, clear_page_nosave);
167                 list = lp;
168         }
169 }
170 
171 /**
172   *     struct chain_allocator is used for allocating small objects out of
173   *     a linked list of pages called 'the chain'.
174   *
175   *     The chain grows each time when there is no room for a new object in
176   *     the current page.  The allocated objects cannot be freed individually.
177   *     It is only possible to free them all at once, by freeing the entire
178   *     chain.
179   *
180   *     NOTE: The chain allocator may be inefficient if the allocated objects
181   *     are not much smaller than PAGE_SIZE.
182   */
183 
184 struct chain_allocator {
185         struct linked_page *chain;      /* the chain */
186         unsigned int used_space;        /* total size of objects allocated out
187                                          * of the current page
188                                          */
189         gfp_t gfp_mask;         /* mask for allocating pages */
190         int safe_needed;        /* if set, only "safe" pages are allocated */
191 };
192 
193 static void
194 chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
195 {
196         ca->chain = NULL;
197         ca->used_space = LINKED_PAGE_DATA_SIZE;
198         ca->gfp_mask = gfp_mask;
199         ca->safe_needed = safe_needed;
200 }
201 
202 static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
203 {
204         void *ret;
205 
206         if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
207                 struct linked_page *lp;
208 
209                 lp = get_image_page(ca->gfp_mask, ca->safe_needed);
210                 if (!lp)
211                         return NULL;
212 
213                 lp->next = ca->chain;
214                 ca->chain = lp;
215                 ca->used_space = 0;
216         }
217         ret = ca->chain->data + ca->used_space;
218         ca->used_space += size;
219         return ret;
220 }
221 
222 /**
223  *      Data types related to memory bitmaps.
224  *
225  *      Memory bitmap is a structure consiting of many linked lists of
226  *      objects.  The main list's elements are of type struct zone_bitmap
227  *      and each of them corresonds to one zone.  For each zone bitmap
228  *      object there is a list of objects of type struct bm_block that
229  *      represent each blocks of bitmap in which information is stored.
230  *
231  *      struct memory_bitmap contains a pointer to the main list of zone
232  *      bitmap objects, a struct bm_position used for browsing the bitmap,
233  *      and a pointer to the list of pages used for allocating all of the
234  *      zone bitmap objects and bitmap block objects.
235  *
236  *      NOTE: It has to be possible to lay out the bitmap in memory
237  *      using only allocations of order 0.  Additionally, the bitmap is
238  *      designed to work with arbitrary number of zones (this is over the
239  *      top for now, but let's avoid making unnecessary assumptions ;-).
240  *
241  *      struct zone_bitmap contains a pointer to a list of bitmap block
242  *      objects and a pointer to the bitmap block object that has been
243  *      most recently used for setting bits.  Additionally, it contains the
244  *      pfns that correspond to the start and end of the represented zone.
245  *
246  *      struct bm_block contains a pointer to the memory page in which
247  *      information is stored (in the form of a block of bitmap)
248  *      It also contains the pfns that correspond to the start and end of
249  *      the represented memory area.
250  */
251 
252 #define BM_END_OF_MAP   (~0UL)
253 
254 #define BM_BITS_PER_BLOCK       (PAGE_SIZE * BITS_PER_BYTE)
255 
256 struct bm_block {
257         struct list_head hook;  /* hook into a list of bitmap blocks */
258         unsigned long start_pfn;        /* pfn represented by the first bit */
259         unsigned long end_pfn;  /* pfn represented by the last bit plus 1 */
260         unsigned long *data;    /* bitmap representing pages */
261 };
262 
263 static inline unsigned long bm_block_bits(struct bm_block *bb)
264 {
265         return bb->end_pfn - bb->start_pfn;
266 }
267 
268 /* strcut bm_position is used for browsing memory bitmaps */
269 
270 struct bm_position {
271         struct bm_block *block;
272         int bit;
273 };
274 
275 struct memory_bitmap {
276         struct list_head blocks;        /* list of bitmap blocks */
277         struct linked_page *p_list;     /* list of pages used to store zone
278                                          * bitmap objects and bitmap block
279                                          * objects
280                                          */
281         struct bm_position cur; /* most recently used bit position */
282 };
283 
284 /* Functions that operate on memory bitmaps */
285 
286 static void memory_bm_position_reset(struct memory_bitmap *bm)
287 {
288         bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook);
289         bm->cur.bit = 0;
290 }
291 
292 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
293 
294 /**
295  *      create_bm_block_list - create a list of block bitmap objects
296  *      @pages - number of pages to track
297  *      @list - list to put the allocated blocks into
298  *      @ca - chain allocator to be used for allocating memory
299  */
300 static int create_bm_block_list(unsigned long pages,
301                                 struct list_head *list,
302                                 struct chain_allocator *ca)
303 {
304         unsigned int nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
305 
306         while (nr_blocks-- > 0) {
307                 struct bm_block *bb;
308 
309                 bb = chain_alloc(ca, sizeof(struct bm_block));
310                 if (!bb)
311                         return -ENOMEM;
312                 list_add(&bb->hook, list);
313         }
314 
315         return 0;
316 }
317 
318 struct mem_extent {
319         struct list_head hook;
320         unsigned long start;
321         unsigned long end;
322 };
323 
324 /**
325  *      free_mem_extents - free a list of memory extents
326  *      @list - list of extents to empty
327  */
328 static void free_mem_extents(struct list_head *list)
329 {
330         struct mem_extent *ext, *aux;
331 
332         list_for_each_entry_safe(ext, aux, list, hook) {
333                 list_del(&ext->hook);
334                 kfree(ext);
335         }
336 }
337 
338 /**
339  *      create_mem_extents - create a list of memory extents representing
340  *                           contiguous ranges of PFNs
341  *      @list - list to put the extents into
342  *      @gfp_mask - mask to use for memory allocations
343  */
344 static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
345 {
346         struct zone *zone;
347 
348         INIT_LIST_HEAD(list);
349 
350         for_each_populated_zone(zone) {
351                 unsigned long zone_start, zone_end;
352                 struct mem_extent *ext, *cur, *aux;
353 
354                 zone_start = zone->zone_start_pfn;
355                 zone_end = zone->zone_start_pfn + zone->spanned_pages;
356 
357                 list_for_each_entry(ext, list, hook)
358                         if (zone_start <= ext->end)
359                                 break;
360 
361                 if (&ext->hook == list || zone_end < ext->start) {
362                         /* New extent is necessary */
363                         struct mem_extent *new_ext;
364 
365                         new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
366                         if (!new_ext) {
367                                 free_mem_extents(list);
368                                 return -ENOMEM;
369                         }
370                         new_ext->start = zone_start;
371                         new_ext->end = zone_end;
372                         list_add_tail(&new_ext->hook, &ext->hook);
373                         continue;
374                 }
375 
376                 /* Merge this zone's range of PFNs with the existing one */
377                 if (zone_start < ext->start)
378                         ext->start = zone_start;
379                 if (zone_end > ext->end)
380                         ext->end = zone_end;
381 
382                 /* More merging may be possible */
383                 cur = ext;
384                 list_for_each_entry_safe_continue(cur, aux, list, hook) {
385                         if (zone_end < cur->start)
386                                 break;
387                         if (zone_end < cur->end)
388                                 ext->end = cur->end;
389                         list_del(&cur->hook);
390                         kfree(cur);
391                 }
392         }
393 
394         return 0;
395 }
396 
397 /**
398   *     memory_bm_create - allocate memory for a memory bitmap
399   */
400 static int
401 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
402 {
403         struct chain_allocator ca;
404         struct list_head mem_extents;
405         struct mem_extent *ext;
406         int error;
407 
408         chain_init(&ca, gfp_mask, safe_needed);
409         INIT_LIST_HEAD(&bm->blocks);
410 
411         error = create_mem_extents(&mem_extents, gfp_mask);
412         if (error)
413                 return error;
414 
415         list_for_each_entry(ext, &mem_extents, hook) {
416                 struct bm_block *bb;
417                 unsigned long pfn = ext->start;
418                 unsigned long pages = ext->end - ext->start;
419 
420                 bb = list_entry(bm->blocks.prev, struct bm_block, hook);
421 
422                 error = create_bm_block_list(pages, bm->blocks.prev, &ca);
423                 if (error)
424                         goto Error;
425 
426                 list_for_each_entry_continue(bb, &bm->blocks, hook) {
427                         bb->data = get_image_page(gfp_mask, safe_needed);
428                         if (!bb->data) {
429                                 error = -ENOMEM;
430                                 goto Error;
431                         }
432 
433                         bb->start_pfn = pfn;
434                         if (pages >= BM_BITS_PER_BLOCK) {
435                                 pfn += BM_BITS_PER_BLOCK;
436                                 pages -= BM_BITS_PER_BLOCK;
437                         } else {
438                                 /* This is executed only once in the loop */
439                                 pfn += pages;
440                         }
441                         bb->end_pfn = pfn;
442                 }
443         }
444 
445         bm->p_list = ca.chain;
446         memory_bm_position_reset(bm);
447  Exit:
448         free_mem_extents(&mem_extents);
449         return error;
450 
451  Error:
452         bm->p_list = ca.chain;
453         memory_bm_free(bm, PG_UNSAFE_CLEAR);
454         goto Exit;
455 }
456 
457 /**
458   *     memory_bm_free - free memory occupied by the memory bitmap @bm
459   */
460 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
461 {
462         struct bm_block *bb;
463 
464         list_for_each_entry(bb, &bm->blocks, hook)
465                 if (bb->data)
466                         free_image_page(bb->data, clear_nosave_free);
467 
468         free_list_of_pages(bm->p_list, clear_nosave_free);
469 
470         INIT_LIST_HEAD(&bm->blocks);
471 }
472 
473 /**
474  *      memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
475  *      to given pfn.  The cur_zone_bm member of @bm and the cur_block member
476  *      of @bm->cur_zone_bm are updated.
477  */
478 static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
479                                 void **addr, unsigned int *bit_nr)
480 {
481         struct bm_block *bb;
482 
483         /*
484          * Check if the pfn corresponds to the current bitmap block and find
485          * the block where it fits if this is not the case.
486          */
487         bb = bm->cur.block;
488         if (pfn < bb->start_pfn)
489                 list_for_each_entry_continue_reverse(bb, &bm->blocks, hook)
490                         if (pfn >= bb->start_pfn)
491                                 break;
492 
493         if (pfn >= bb->end_pfn)
494                 list_for_each_entry_continue(bb, &bm->blocks, hook)
495                         if (pfn >= bb->start_pfn && pfn < bb->end_pfn)
496                                 break;
497 
498         if (&bb->hook == &bm->blocks)
499                 return -EFAULT;
500 
501         /* The block has been found */
502         bm->cur.block = bb;
503         pfn -= bb->start_pfn;
504         bm->cur.bit = pfn + 1;
505         *bit_nr = pfn;
506         *addr = bb->data;
507         return 0;
508 }
509 
510 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
511 {
512         void *addr;
513         unsigned int bit;
514         int error;
515 
516         error = memory_bm_find_bit(bm, pfn, &addr, &bit);
517         BUG_ON(error);
518         set_bit(bit, addr);
519 }
520 
521 static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
522 {
523         void *addr;
524         unsigned int bit;
525         int error;
526 
527         error = memory_bm_find_bit(bm, pfn, &addr, &bit);
528         if (!error)
529                 set_bit(bit, addr);
530         return error;
531 }
532 
533 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
534 {
535         void *addr;
536         unsigned int bit;
537         int error;
538 
539         error = memory_bm_find_bit(bm, pfn, &addr, &bit);
540         BUG_ON(error);
541         clear_bit(bit, addr);
542 }
543 
544 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
545 {
546         void *addr;
547         unsigned int bit;
548         int error;
549 
550         error = memory_bm_find_bit(bm, pfn, &addr, &bit);
551         BUG_ON(error);
552         return test_bit(bit, addr);
553 }
554 
555 static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
556 {
557         void *addr;
558         unsigned int bit;
559 
560         return !memory_bm_find_bit(bm, pfn, &addr, &bit);
561 }
562 
563 /**
564  *      memory_bm_next_pfn - find the pfn that corresponds to the next set bit
565  *      in the bitmap @bm.  If the pfn cannot be found, BM_END_OF_MAP is
566  *      returned.
567  *
568  *      It is required to run memory_bm_position_reset() before the first call to
569  *      this function.
570  */
571 
572 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
573 {
574         struct bm_block *bb;
575         int bit;
576 
577         bb = bm->cur.block;
578         do {
579                 bit = bm->cur.bit;
580                 bit = find_next_bit(bb->data, bm_block_bits(bb), bit);
581                 if (bit < bm_block_bits(bb))
582                         goto Return_pfn;
583 
584                 bb = list_entry(bb->hook.next, struct bm_block, hook);
585                 bm->cur.block = bb;
586                 bm->cur.bit = 0;
587         } while (&bb->hook != &bm->blocks);
588 
589         memory_bm_position_reset(bm);
590         return BM_END_OF_MAP;
591 
592  Return_pfn:
593         bm->cur.bit = bit + 1;
594         return bb->start_pfn + bit;
595 }
596 
597 /**
598  *      This structure represents a range of page frames the contents of which
599  *      should not be saved during the suspend.
600  */
601 
602 struct nosave_region {
603         struct list_head list;
604         unsigned long start_pfn;
605         unsigned long end_pfn;
606 };
607 
608 static LIST_HEAD(nosave_regions);
609 
610 /**
611  *      register_nosave_region - register a range of page frames the contents
612  *      of which should not be saved during the suspend (to be used in the early
613  *      initialization code)
614  */
615 
616 void __init
617 __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
618                          int use_kmalloc)
619 {
620         struct nosave_region *region;
621 
622         if (start_pfn >= end_pfn)
623                 return;
624 
625         if (!list_empty(&nosave_regions)) {
626                 /* Try to extend the previous region (they should be sorted) */
627                 region = list_entry(nosave_regions.prev,
628                                         struct nosave_region, list);
629                 if (region->end_pfn == start_pfn) {
630                         region->end_pfn = end_pfn;
631                         goto Report;
632                 }
633         }
634         if (use_kmalloc) {
635                 /* during init, this shouldn't fail */
636                 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
637                 BUG_ON(!region);
638         } else
639                 /* This allocation cannot fail */
640                 region = alloc_bootmem(sizeof(struct nosave_region));
641         region->start_pfn = start_pfn;
642         region->end_pfn = end_pfn;
643         list_add_tail(&region->list, &nosave_regions);
644  Report:
645         printk(KERN_INFO "PM: Registered nosave memory: %016lx - %016lx\n",
646                 start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
647 }
648 
649 /*
650  * Set bits in this map correspond to the page frames the contents of which
651  * should not be saved during the suspend.
652  */
653 static struct memory_bitmap *forbidden_pages_map;
654 
655 /* Set bits in this map correspond to free page frames. */
656 static struct memory_bitmap *free_pages_map;
657 
658 /*
659  * Each page frame allocated for creating the image is marked by setting the
660  * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
661  */
662 
663 void swsusp_set_page_free(struct page *page)
664 {
665         if (free_pages_map)
666                 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
667 }
668 
669 static int swsusp_page_is_free(struct page *page)
670 {
671         return free_pages_map ?
672                 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
673 }
674 
675 void swsusp_unset_page_free(struct page *page)
676 {
677         if (free_pages_map)
678                 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
679 }
680 
681 static void swsusp_set_page_forbidden(struct page *page)
682 {
683         if (forbidden_pages_map)
684                 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
685 }
686 
687 int swsusp_page_is_forbidden(struct page *page)
688 {
689         return forbidden_pages_map ?
690                 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
691 }
692 
693 static void swsusp_unset_page_forbidden(struct page *page)
694 {
695         if (forbidden_pages_map)
696                 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
697 }
698 
699 /**
700  *      mark_nosave_pages - set bits corresponding to the page frames the
701  *      contents of which should not be saved in a given bitmap.
702  */
703 
704 static void mark_nosave_pages(struct memory_bitmap *bm)
705 {
706         struct nosave_region *region;
707 
708         if (list_empty(&nosave_regions))
709                 return;
710 
711         list_for_each_entry(region, &nosave_regions, list) {
712                 unsigned long pfn;
713 
714                 pr_debug("PM: Marking nosave pages: [mem %#010llx-%#010llx]\n",
715                          (unsigned long long) region->start_pfn << PAGE_SHIFT,
716                          ((unsigned long long) region->end_pfn << PAGE_SHIFT)
717                                 - 1);
718 
719                 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
720                         if (pfn_valid(pfn)) {
721                                 /*
722                                  * It is safe to ignore the result of
723                                  * mem_bm_set_bit_check() here, since we won't
724                                  * touch the PFNs for which the error is
725                                  * returned anyway.
726                                  */
727                                 mem_bm_set_bit_check(bm, pfn);
728                         }
729         }
730 }
731 
732 /**
733  *      create_basic_memory_bitmaps - create bitmaps needed for marking page
734  *      frames that should not be saved and free page frames.  The pointers
735  *      forbidden_pages_map and free_pages_map are only modified if everything
736  *      goes well, because we don't want the bits to be used before both bitmaps
737  *      are set up.
738  */
739 
740 int create_basic_memory_bitmaps(void)
741 {
742         struct memory_bitmap *bm1, *bm2;
743         int error = 0;
744 
745         BUG_ON(forbidden_pages_map || free_pages_map);
746 
747         bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
748         if (!bm1)
749                 return -ENOMEM;
750 
751         error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
752         if (error)
753                 goto Free_first_object;
754 
755         bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
756         if (!bm2)
757                 goto Free_first_bitmap;
758 
759         error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
760         if (error)
761                 goto Free_second_object;
762 
763         forbidden_pages_map = bm1;
764         free_pages_map = bm2;
765         mark_nosave_pages(forbidden_pages_map);
766 
767         pr_debug("PM: Basic memory bitmaps created\n");
768 
769         return 0;
770 
771  Free_second_object:
772         kfree(bm2);
773  Free_first_bitmap:
774         memory_bm_free(bm1, PG_UNSAFE_CLEAR);
775  Free_first_object:
776         kfree(bm1);
777         return -ENOMEM;
778 }
779 
780 /**
781  *      free_basic_memory_bitmaps - free memory bitmaps allocated by
782  *      create_basic_memory_bitmaps().  The auxiliary pointers are necessary
783  *      so that the bitmaps themselves are not referred to while they are being
784  *      freed.
785  */
786 
787 void free_basic_memory_bitmaps(void)
788 {
789         struct memory_bitmap *bm1, *bm2;
790 
791         BUG_ON(!(forbidden_pages_map && free_pages_map));
792 
793         bm1 = forbidden_pages_map;
794         bm2 = free_pages_map;
795         forbidden_pages_map = NULL;
796         free_pages_map = NULL;
797         memory_bm_free(bm1, PG_UNSAFE_CLEAR);
798         kfree(bm1);
799         memory_bm_free(bm2, PG_UNSAFE_CLEAR);
800         kfree(bm2);
801 
802         pr_debug("PM: Basic memory bitmaps freed\n");
803 }
804 
805 /**
806  *      snapshot_additional_pages - estimate the number of additional pages
807  *      be needed for setting up the suspend image data structures for given
808  *      zone (usually the returned value is greater than the exact number)
809  */
810 
811 unsigned int snapshot_additional_pages(struct zone *zone)
812 {
813         unsigned int res;
814 
815         res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
816         res += DIV_ROUND_UP(res * sizeof(struct bm_block),
817                             LINKED_PAGE_DATA_SIZE);
818         return 2 * res;
819 }
820 
821 #ifdef CONFIG_HIGHMEM
822 /**
823  *      count_free_highmem_pages - compute the total number of free highmem
824  *      pages, system-wide.
825  */
826 
827 static unsigned int count_free_highmem_pages(void)
828 {
829         struct zone *zone;
830         unsigned int cnt = 0;
831 
832         for_each_populated_zone(zone)
833                 if (is_highmem(zone))
834                         cnt += zone_page_state(zone, NR_FREE_PAGES);
835 
836         return cnt;
837 }
838 
839 /**
840  *      saveable_highmem_page - Determine whether a highmem page should be
841  *      included in the suspend image.
842  *
843  *      We should save the page if it isn't Nosave or NosaveFree, or Reserved,
844  *      and it isn't a part of a free chunk of pages.
845  */
846 static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
847 {
848         struct page *page;
849 
850         if (!pfn_valid(pfn))
851                 return NULL;
852 
853         page = pfn_to_page(pfn);
854         if (page_zone(page) != zone)
855                 return NULL;
856 
857         BUG_ON(!PageHighMem(page));
858 
859         if (swsusp_page_is_forbidden(page) ||  swsusp_page_is_free(page) ||
860             PageReserved(page))
861                 return NULL;
862 
863         if (page_is_guard(page))
864                 return NULL;
865 
866         return page;
867 }
868 
869 /**
870  *      count_highmem_pages - compute the total number of saveable highmem
871  *      pages.
872  */
873 
874 static unsigned int count_highmem_pages(void)
875 {
876         struct zone *zone;
877         unsigned int n = 0;
878 
879         for_each_populated_zone(zone) {
880                 unsigned long pfn, max_zone_pfn;
881 
882                 if (!is_highmem(zone))
883                         continue;
884 
885                 mark_free_pages(zone);
886                 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
887                 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
888                         if (saveable_highmem_page(zone, pfn))
889                                 n++;
890         }
891         return n;
892 }
893 #else
894 static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
895 {
896         return NULL;
897 }
898 #endif /* CONFIG_HIGHMEM */
899 
900 /**
901  *      saveable_page - Determine whether a non-highmem page should be included
902  *      in the suspend image.
903  *
904  *      We should save the page if it isn't Nosave, and is not in the range
905  *      of pages statically defined as 'unsaveable', and it isn't a part of
906  *      a free chunk of pages.
907  */
908 static struct page *saveable_page(struct zone *zone, unsigned long pfn)
909 {
910         struct page *page;
911 
912         if (!pfn_valid(pfn))
913                 return NULL;
914 
915         page = pfn_to_page(pfn);
916         if (page_zone(page) != zone)
917                 return NULL;
918 
919         BUG_ON(PageHighMem(page));
920 
921         if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
922                 return NULL;
923 
924         if (PageReserved(page)
925             && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
926                 return NULL;
927 
928         if (page_is_guard(page))
929                 return NULL;
930 
931         return page;
932 }
933 
934 /**
935  *      count_data_pages - compute the total number of saveable non-highmem
936  *      pages.
937  */
938 
939 static unsigned int count_data_pages(void)
940 {
941         struct zone *zone;
942         unsigned long pfn, max_zone_pfn;
943         unsigned int n = 0;
944 
945         for_each_populated_zone(zone) {
946                 if (is_highmem(zone))
947                         continue;
948 
949                 mark_free_pages(zone);
950                 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
951                 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
952                         if (saveable_page(zone, pfn))
953                                 n++;
954         }
955         return n;
956 }
957 
958 /* This is needed, because copy_page and memcpy are not usable for copying
959  * task structs.
960  */
961 static inline void do_copy_page(long *dst, long *src)
962 {
963         int n;
964 
965         for (n = PAGE_SIZE / sizeof(long); n; n--)
966                 *dst++ = *src++;
967 }
968 
969 
970 /**
971  *      safe_copy_page - check if the page we are going to copy is marked as
972  *              present in the kernel page tables (this always is the case if
973  *              CONFIG_DEBUG_PAGEALLOC is not set and in that case
974  *              kernel_page_present() always returns 'true').
975  */
976 static void safe_copy_page(void *dst, struct page *s_page)
977 {
978         if (kernel_page_present(s_page)) {
979                 do_copy_page(dst, page_address(s_page));
980         } else {
981                 kernel_map_pages(s_page, 1, 1);
982                 do_copy_page(dst, page_address(s_page));
983                 kernel_map_pages(s_page, 1, 0);
984         }
985 }
986 
987 
988 #ifdef CONFIG_HIGHMEM
989 static inline struct page *
990 page_is_saveable(struct zone *zone, unsigned long pfn)
991 {
992         return is_highmem(zone) ?
993                 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
994 }
995 
996 static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
997 {
998         struct page *s_page, *d_page;
999         void *src, *dst;
1000 
1001         s_page = pfn_to_page(src_pfn);
1002         d_page = pfn_to_page(dst_pfn);
1003         if (PageHighMem(s_page)) {
1004                 src = kmap_atomic(s_page);
1005                 dst = kmap_atomic(d_page);
1006                 do_copy_page(dst, src);
1007                 kunmap_atomic(dst);
1008                 kunmap_atomic(src);
1009         } else {
1010                 if (PageHighMem(d_page)) {
1011                         /* Page pointed to by src may contain some kernel
1012                          * data modified by kmap_atomic()
1013                          */
1014                         safe_copy_page(buffer, s_page);
1015                         dst = kmap_atomic(d_page);
1016                         copy_page(dst, buffer);
1017                         kunmap_atomic(dst);
1018                 } else {
1019                         safe_copy_page(page_address(d_page), s_page);
1020                 }
1021         }
1022 }
1023 #else
1024 #define page_is_saveable(zone, pfn)     saveable_page(zone, pfn)
1025 
1026 static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1027 {
1028         safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1029                                 pfn_to_page(src_pfn));
1030 }
1031 #endif /* CONFIG_HIGHMEM */
1032 
1033 static void
1034 copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
1035 {
1036         struct zone *zone;
1037         unsigned long pfn;
1038 
1039         for_each_populated_zone(zone) {
1040                 unsigned long max_zone_pfn;
1041 
1042                 mark_free_pages(zone);
1043                 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1044                 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1045                         if (page_is_saveable(zone, pfn))
1046                                 memory_bm_set_bit(orig_bm, pfn);
1047         }
1048         memory_bm_position_reset(orig_bm);
1049         memory_bm_position_reset(copy_bm);
1050         for(;;) {
1051                 pfn = memory_bm_next_pfn(orig_bm);
1052                 if (unlikely(pfn == BM_END_OF_MAP))
1053                         break;
1054                 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1055         }
1056 }
1057 
1058 /* Total number of image pages */
1059 static unsigned int nr_copy_pages;
1060 /* Number of pages needed for saving the original pfns of the image pages */
1061 static unsigned int nr_meta_pages;
1062 /*
1063  * Numbers of normal and highmem page frames allocated for hibernation image
1064  * before suspending devices.
1065  */
1066 unsigned int alloc_normal, alloc_highmem;
1067 /*
1068  * Memory bitmap used for marking saveable pages (during hibernation) or
1069  * hibernation image pages (during restore)
1070  */
1071 static struct memory_bitmap orig_bm;
1072 /*
1073  * Memory bitmap used during hibernation for marking allocated page frames that
1074  * will contain copies of saveable pages.  During restore it is initially used
1075  * for marking hibernation image pages, but then the set bits from it are
1076  * duplicated in @orig_bm and it is released.  On highmem systems it is next
1077  * used for marking "safe" highmem pages, but it has to be reinitialized for
1078  * this purpose.
1079  */
1080 static struct memory_bitmap copy_bm;
1081 
1082 /**
1083  *      swsusp_free - free pages allocated for the suspend.
1084  *
1085  *      Suspend pages are alocated before the atomic copy is made, so we
1086  *      need to release them after the resume.
1087  */
1088 
1089 void swsusp_free(void)
1090 {
1091         struct zone *zone;
1092         unsigned long pfn, max_zone_pfn;
1093 
1094         for_each_populated_zone(zone) {
1095                 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1096                 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1097                         if (pfn_valid(pfn)) {
1098                                 struct page *page = pfn_to_page(pfn);
1099 
1100                                 if (swsusp_page_is_forbidden(page) &&
1101                                     swsusp_page_is_free(page)) {
1102                                         swsusp_unset_page_forbidden(page);
1103                                         swsusp_unset_page_free(page);
1104                                         __free_page(page);
1105                                 }
1106                         }
1107         }
1108         nr_copy_pages = 0;
1109         nr_meta_pages = 0;
1110         restore_pblist = NULL;
1111         buffer = NULL;
1112         alloc_normal = 0;
1113         alloc_highmem = 0;
1114 }
1115 
1116 /* Helper functions used for the shrinking of memory. */
1117 
1118 #define GFP_IMAGE       (GFP_KERNEL | __GFP_NOWARN)
1119 
1120 /**
1121  * preallocate_image_pages - Allocate a number of pages for hibernation image
1122  * @nr_pages: Number of page frames to allocate.
1123  * @mask: GFP flags to use for the allocation.
1124  *
1125  * Return value: Number of page frames actually allocated
1126  */
1127 static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1128 {
1129         unsigned long nr_alloc = 0;
1130 
1131         while (nr_pages > 0) {
1132                 struct page *page;
1133 
1134                 page = alloc_image_page(mask);
1135                 if (!page)
1136                         break;
1137                 memory_bm_set_bit(&copy_bm, page_to_pfn(page));
1138                 if (PageHighMem(page))
1139                         alloc_highmem++;
1140                 else
1141                         alloc_normal++;
1142                 nr_pages--;
1143                 nr_alloc++;
1144         }
1145 
1146         return nr_alloc;
1147 }
1148 
1149 static unsigned long preallocate_image_memory(unsigned long nr_pages,
1150                                               unsigned long avail_normal)
1151 {
1152         unsigned long alloc;
1153 
1154         if (avail_normal <= alloc_normal)
1155                 return 0;
1156 
1157         alloc = avail_normal - alloc_normal;
1158         if (nr_pages < alloc)
1159                 alloc = nr_pages;
1160 
1161         return preallocate_image_pages(alloc, GFP_IMAGE);
1162 }
1163 
1164 #ifdef CONFIG_HIGHMEM
1165 static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1166 {
1167         return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1168 }
1169 
1170 /**
1171  *  __fraction - Compute (an approximation of) x * (multiplier / base)
1172  */
1173 static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1174 {
1175         x *= multiplier;
1176         do_div(x, base);
1177         return (unsigned long)x;
1178 }
1179 
1180 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1181                                                 unsigned long highmem,
1182                                                 unsigned long total)
1183 {
1184         unsigned long alloc = __fraction(nr_pages, highmem, total);
1185 
1186         return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1187 }
1188 #else /* CONFIG_HIGHMEM */
1189 static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1190 {
1191         return 0;
1192 }
1193 
1194 static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1195                                                 unsigned long highmem,
1196                                                 unsigned long total)
1197 {
1198         return 0;
1199 }
1200 #endif /* CONFIG_HIGHMEM */
1201 
1202 /**
1203  * free_unnecessary_pages - Release preallocated pages not needed for the image
1204  */
1205 static void free_unnecessary_pages(void)
1206 {
1207         unsigned long save, to_free_normal, to_free_highmem;
1208 
1209         save = count_data_pages();
1210         if (alloc_normal >= save) {
1211                 to_free_normal = alloc_normal - save;
1212                 save = 0;
1213         } else {
1214                 to_free_normal = 0;
1215                 save -= alloc_normal;
1216         }
1217         save += count_highmem_pages();
1218         if (alloc_highmem >= save) {
1219                 to_free_highmem = alloc_highmem - save;
1220         } else {
1221                 to_free_highmem = 0;
1222                 save -= alloc_highmem;
1223                 if (to_free_normal > save)
1224                         to_free_normal -= save;
1225                 else
1226                         to_free_normal = 0;
1227         }
1228 
1229         memory_bm_position_reset(&copy_bm);
1230 
1231         while (to_free_normal > 0 || to_free_highmem > 0) {
1232                 unsigned long pfn = memory_bm_next_pfn(&copy_bm);
1233                 struct page *page = pfn_to_page(pfn);
1234 
1235                 if (PageHighMem(page)) {
1236                         if (!to_free_highmem)
1237                                 continue;
1238                         to_free_highmem--;
1239                         alloc_highmem--;
1240                 } else {
1241                         if (!to_free_normal)
1242                                 continue;
1243                         to_free_normal--;
1244                         alloc_normal--;
1245                 }
1246                 memory_bm_clear_bit(&copy_bm, pfn);
1247                 swsusp_unset_page_forbidden(page);
1248                 swsusp_unset_page_free(page);
1249                 __free_page(page);
1250         }
1251 }
1252 
1253 /**
1254  * minimum_image_size - Estimate the minimum acceptable size of an image
1255  * @saveable: Number of saveable pages in the system.
1256  *
1257  * We want to avoid attempting to free too much memory too hard, so estimate the
1258  * minimum acceptable size of a hibernation image to use as the lower limit for
1259  * preallocating memory.
1260  *
1261  * We assume that the minimum image size should be proportional to
1262  *
1263  * [number of saveable pages] - [number of pages that can be freed in theory]
1264  *
1265  * where the second term is the sum of (1) reclaimable slab pages, (2) active
1266  * and (3) inactive anonymouns pages, (4) active and (5) inactive file pages,
1267  * minus mapped file pages.
1268  */
1269 static unsigned long minimum_image_size(unsigned long saveable)
1270 {
1271         unsigned long size;
1272 
1273         size = global_page_state(NR_SLAB_RECLAIMABLE)
1274                 + global_page_state(NR_ACTIVE_ANON)
1275                 + global_page_state(NR_INACTIVE_ANON)
1276                 + global_page_state(NR_ACTIVE_FILE)
1277                 + global_page_state(NR_INACTIVE_FILE)
1278                 - global_page_state(NR_FILE_MAPPED);
1279 
1280         return saveable <= size ? 0 : saveable - size;
1281 }
1282 
1283 /**
1284  * hibernate_preallocate_memory - Preallocate memory for hibernation image
1285  *
1286  * To create a hibernation image it is necessary to make a copy of every page
1287  * frame in use.  We also need a number of page frames to be free during
1288  * hibernation for allocations made while saving the image and for device
1289  * drivers, in case they need to allocate memory from their hibernation
1290  * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1291  * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
1292  * /sys/power/reserved_size, respectively).  To make this happen, we compute the
1293  * total number of available page frames and allocate at least
1294  *
1295  * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1296  *  + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1297  *
1298  * of them, which corresponds to the maximum size of a hibernation image.
1299  *
1300  * If image_size is set below the number following from the above formula,
1301  * the preallocation of memory is continued until the total number of saveable
1302  * pages in the system is below the requested image size or the minimum
1303  * acceptable image size returned by minimum_image_size(), whichever is greater.
1304  */
1305 int hibernate_preallocate_memory(void)
1306 {
1307         struct zone *zone;
1308         unsigned long saveable, size, max_size, count, highmem, pages = 0;
1309         unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1310         struct timeval start, stop;
1311         int error;
1312 
1313         printk(KERN_INFO "PM: Preallocating image memory... ");
1314         do_gettimeofday(&start);
1315 
1316         error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1317         if (error)
1318                 goto err_out;
1319 
1320         error = memory_bm_create(&copy_bm, GFP_IMAGE, PG_ANY);
1321         if (error)
1322                 goto err_out;
1323 
1324         alloc_normal = 0;
1325         alloc_highmem = 0;
1326 
1327         /* Count the number of saveable data pages. */
1328         save_highmem = count_highmem_pages();
1329         saveable = count_data_pages();
1330 
1331         /*
1332          * Compute the total number of page frames we can use (count) and the
1333          * number of pages needed for image metadata (size).
1334          */
1335         count = saveable;
1336         saveable += save_highmem;
1337         highmem = save_highmem;
1338         size = 0;
1339         for_each_populated_zone(zone) {
1340                 size += snapshot_additional_pages(zone);
1341                 if (is_highmem(zone))
1342                         highmem += zone_page_state(zone, NR_FREE_PAGES);
1343                 else
1344                         count += zone_page_state(zone, NR_FREE_PAGES);
1345         }
1346         avail_normal = count;
1347         count += highmem;
1348         count -= totalreserve_pages;
1349 
1350         /* Add number of pages required for page keys (s390 only). */
1351         size += page_key_additional_pages(saveable);
1352 
1353         /* Compute the maximum number of saveable pages to leave in memory. */
1354         max_size = (count - (size + PAGES_FOR_IO)) / 2
1355                         - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1356         /* Compute the desired number of image pages specified by image_size. */
1357         size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1358         if (size > max_size)
1359                 size = max_size;
1360         /*
1361          * If the desired number of image pages is at least as large as the
1362          * current number of saveable pages in memory, allocate page frames for
1363          * the image and we're done.
1364          */
1365         if (size >= saveable) {
1366                 pages = preallocate_image_highmem(save_highmem);
1367                 pages += preallocate_image_memory(saveable - pages, avail_normal);
1368                 goto out;
1369         }
1370 
1371         /* Estimate the minimum size of the image. */
1372         pages = minimum_image_size(saveable);
1373         /*
1374          * To avoid excessive pressure on the normal zone, leave room in it to
1375          * accommodate an image of the minimum size (unless it's already too
1376          * small, in which case don't preallocate pages from it at all).
1377          */
1378         if (avail_normal > pages)
1379                 avail_normal -= pages;
1380         else
1381                 avail_normal = 0;
1382         if (size < pages)
1383                 size = min_t(unsigned long, pages, max_size);
1384 
1385         /*
1386          * Let the memory management subsystem know that we're going to need a
1387          * large number of page frames to allocate and make it free some memory.
1388          * NOTE: If this is not done, performance will be hurt badly in some
1389          * test cases.
1390          */
1391         shrink_all_memory(saveable - size);
1392 
1393         /*
1394          * The number of saveable pages in memory was too high, so apply some
1395          * pressure to decrease it.  First, make room for the largest possible
1396          * image and fail if that doesn't work.  Next, try to decrease the size
1397          * of the image as much as indicated by 'size' using allocations from
1398          * highmem and non-highmem zones separately.
1399          */
1400         pages_highmem = preallocate_image_highmem(highmem / 2);
1401         alloc = (count - max_size) - pages_highmem;
1402         pages = preallocate_image_memory(alloc, avail_normal);
1403         if (pages < alloc) {
1404                 /* We have exhausted non-highmem pages, try highmem. */
1405                 alloc -= pages;
1406                 pages += pages_highmem;
1407                 pages_highmem = preallocate_image_highmem(alloc);
1408                 if (pages_highmem < alloc)
1409                         goto err_out;
1410                 pages += pages_highmem;
1411                 /*
1412                  * size is the desired number of saveable pages to leave in
1413                  * memory, so try to preallocate (all memory - size) pages.
1414                  */
1415                 alloc = (count - pages) - size;
1416                 pages += preallocate_image_highmem(alloc);
1417         } else {
1418                 /*
1419                  * There are approximately max_size saveable pages at this point
1420                  * and we want to reduce this number down to size.
1421                  */
1422                 alloc = max_size - size;
1423                 size = preallocate_highmem_fraction(alloc, highmem, count);
1424                 pages_highmem += size;
1425                 alloc -= size;
1426                 size = preallocate_image_memory(alloc, avail_normal);
1427                 pages_highmem += preallocate_image_highmem(alloc - size);
1428                 pages += pages_highmem + size;
1429         }
1430 
1431         /*
1432          * We only need as many page frames for the image as there are saveable
1433          * pages in memory, but we have allocated more.  Release the excessive
1434          * ones now.
1435          */
1436         free_unnecessary_pages();
1437 
1438  out:
1439         do_gettimeofday(&stop);
1440         printk(KERN_CONT "done (allocated %lu pages)\n", pages);
1441         swsusp_show_speed(&start, &stop, pages, "Allocated");
1442 
1443         return 0;
1444 
1445  err_out:
1446         printk(KERN_CONT "\n");
1447         swsusp_free();
1448         return -ENOMEM;
1449 }
1450 
1451 #ifdef CONFIG_HIGHMEM
1452 /**
1453   *     count_pages_for_highmem - compute the number of non-highmem pages
1454   *     that will be necessary for creating copies of highmem pages.
1455   */
1456 
1457 static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1458 {
1459         unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1460 
1461         if (free_highmem >= nr_highmem)
1462                 nr_highmem = 0;
1463         else
1464                 nr_highmem -= free_highmem;
1465 
1466         return nr_highmem;
1467 }
1468 #else
1469 static unsigned int
1470 count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1471 #endif /* CONFIG_HIGHMEM */
1472 
1473 /**
1474  *      enough_free_mem - Make sure we have enough free memory for the
1475  *      snapshot image.
1476  */
1477 
1478 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1479 {
1480         struct zone *zone;
1481         unsigned int free = alloc_normal;
1482 
1483         for_each_populated_zone(zone)
1484                 if (!is_highmem(zone))
1485                         free += zone_page_state(zone, NR_FREE_PAGES);
1486 
1487         nr_pages += count_pages_for_highmem(nr_highmem);
1488         pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n",
1489                 nr_pages, PAGES_FOR_IO, free);
1490 
1491         return free > nr_pages + PAGES_FOR_IO;
1492 }
1493 
1494 #ifdef CONFIG_HIGHMEM
1495 /**
1496  *      get_highmem_buffer - if there are some highmem pages in the suspend
1497  *      image, we may need the buffer to copy them and/or load their data.
1498  */
1499 
1500 static inline int get_highmem_buffer(int safe_needed)
1501 {
1502         buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
1503         return buffer ? 0 : -ENOMEM;
1504 }
1505 
1506 /**
1507  *      alloc_highmem_image_pages - allocate some highmem pages for the image.
1508  *      Try to allocate as many pages as needed, but if the number of free
1509  *      highmem pages is lesser than that, allocate them all.
1510  */
1511 
1512 static inline unsigned int
1513 alloc_highmem_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
1514 {
1515         unsigned int to_alloc = count_free_highmem_pages();
1516 
1517         if (to_alloc > nr_highmem)
1518                 to_alloc = nr_highmem;
1519 
1520         nr_highmem -= to_alloc;
1521         while (to_alloc-- > 0) {
1522                 struct page *page;
1523 
1524                 page = alloc_image_page(__GFP_HIGHMEM);
1525                 memory_bm_set_bit(bm, page_to_pfn(page));
1526         }
1527         return nr_highmem;
1528 }
1529 #else
1530 static inline int get_highmem_buffer(int safe_needed) { return 0; }
1531 
1532 static inline unsigned int
1533 alloc_highmem_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
1534 #endif /* CONFIG_HIGHMEM */
1535 
1536 /**
1537  *      swsusp_alloc - allocate memory for the suspend image
1538  *
1539  *      We first try to allocate as many highmem pages as there are
1540  *      saveable highmem pages in the system.  If that fails, we allocate
1541  *      non-highmem pages for the copies of the remaining highmem ones.
1542  *
1543  *      In this approach it is likely that the copies of highmem pages will
1544  *      also be located in the high memory, because of the way in which
1545  *      copy_data_pages() works.
1546  */
1547 
1548 static int
1549 swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
1550                 unsigned int nr_pages, unsigned int nr_highmem)
1551 {
1552         if (nr_highmem > 0) {
1553                 if (get_highmem_buffer(PG_ANY))
1554                         goto err_out;
1555                 if (nr_highmem > alloc_highmem) {
1556                         nr_highmem -= alloc_highmem;
1557                         nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1558                 }
1559         }
1560         if (nr_pages > alloc_normal) {
1561                 nr_pages -= alloc_normal;
1562                 while (nr_pages-- > 0) {
1563                         struct page *page;
1564 
1565                         page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
1566                         if (!page)
1567                                 goto err_out;
1568                         memory_bm_set_bit(copy_bm, page_to_pfn(page));
1569                 }
1570         }
1571 
1572         return 0;
1573 
1574  err_out:
1575         swsusp_free();
1576         return -ENOMEM;
1577 }
1578 
1579 asmlinkage int swsusp_save(void)
1580 {
1581         unsigned int nr_pages, nr_highmem;
1582 
1583         printk(KERN_INFO "PM: Creating hibernation image:\n");
1584 
1585         drain_local_pages(NULL);
1586         nr_pages = count_data_pages();
1587         nr_highmem = count_highmem_pages();
1588         printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem);
1589 
1590         if (!enough_free_mem(nr_pages, nr_highmem)) {
1591                 printk(KERN_ERR "PM: Not enough free memory\n");
1592                 return -ENOMEM;
1593         }
1594 
1595         if (swsusp_alloc(&orig_bm, &copy_bm, nr_pages, nr_highmem)) {
1596                 printk(KERN_ERR "PM: Memory allocation failed\n");
1597                 return -ENOMEM;
1598         }
1599 
1600         /* During allocating of suspend pagedir, new cold pages may appear.
1601          * Kill them.
1602          */
1603         drain_local_pages(NULL);
1604         copy_data_pages(&copy_bm, &orig_bm);
1605 
1606         /*
1607          * End of critical section. From now on, we can write to memory,
1608          * but we should not touch disk. This specially means we must _not_
1609          * touch swap space! Except we must write out our image of course.
1610          */
1611 
1612         nr_pages += nr_highmem;
1613         nr_copy_pages = nr_pages;
1614         nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
1615 
1616         printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n",
1617                 nr_pages);
1618 
1619         return 0;
1620 }
1621 
1622 #ifndef CONFIG_ARCH_HIBERNATION_HEADER
1623 static int init_header_complete(struct swsusp_info *info)
1624 {
1625         memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
1626         info->version_code = LINUX_VERSION_CODE;
1627         return 0;
1628 }
1629 
1630 static char *check_image_kernel(struct swsusp_info *info)
1631 {
1632         if (info->version_code != LINUX_VERSION_CODE)
1633                 return "kernel version";
1634         if (strcmp(info->uts.sysname,init_utsname()->sysname))
1635                 return "system type";
1636         if (strcmp(info->uts.release,init_utsname()->release))
1637                 return "kernel release";
1638         if (strcmp(info->uts.version,init_utsname()->version))
1639                 return "version";
1640         if (strcmp(info->uts.machine,init_utsname()->machine))
1641                 return "machine";
1642         return NULL;
1643 }
1644 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1645 
1646 unsigned long snapshot_get_image_size(void)
1647 {
1648         return nr_copy_pages + nr_meta_pages + 1;
1649 }
1650 
1651 static int init_header(struct swsusp_info *info)
1652 {
1653         memset(info, 0, sizeof(struct swsusp_info));
1654         info->num_physpages = num_physpages;
1655         info->image_pages = nr_copy_pages;
1656         info->pages = snapshot_get_image_size();
1657         info->size = info->pages;
1658         info->size <<= PAGE_SHIFT;
1659         return init_header_complete(info);
1660 }
1661 
1662 /**
1663  *      pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
1664  *      are stored in the array @buf[] (1 page at a time)
1665  */
1666 
1667 static inline void
1668 pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
1669 {
1670         int j;
1671 
1672         for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1673                 buf[j] = memory_bm_next_pfn(bm);
1674                 if (unlikely(buf[j] == BM_END_OF_MAP))
1675                         break;
1676                 /* Save page key for data page (s390 only). */
1677                 page_key_read(buf + j);
1678         }
1679 }
1680 
1681 /**
1682  *      snapshot_read_next - used for reading the system memory snapshot.
1683  *
1684  *      On the first call to it @handle should point to a zeroed
1685  *      snapshot_handle structure.  The structure gets updated and a pointer
1686  *      to it should be passed to this function every next time.
1687  *
1688  *      On success the function returns a positive number.  Then, the caller
1689  *      is allowed to read up to the returned number of bytes from the memory
1690  *      location computed by the data_of() macro.
1691  *
1692  *      The function returns 0 to indicate the end of data stream condition,
1693  *      and a negative number is returned on error.  In such cases the
1694  *      structure pointed to by @handle is not updated and should not be used
1695  *      any more.
1696  */
1697 
1698 int snapshot_read_next(struct snapshot_handle *handle)
1699 {
1700         if (handle->cur > nr_meta_pages + nr_copy_pages)
1701                 return 0;
1702 
1703         if (!buffer) {
1704                 /* This makes the buffer be freed by swsusp_free() */
1705                 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
1706                 if (!buffer)
1707                         return -ENOMEM;
1708         }
1709         if (!handle->cur) {
1710                 int error;
1711 
1712                 error = init_header((struct swsusp_info *)buffer);
1713                 if (error)
1714                         return error;
1715                 handle->buffer = buffer;
1716                 memory_bm_position_reset(&orig_bm);
1717                 memory_bm_position_reset(&copy_bm);
1718         } else if (handle->cur <= nr_meta_pages) {
1719                 clear_page(buffer);
1720                 pack_pfns(buffer, &orig_bm);
1721         } else {
1722                 struct page *page;
1723 
1724                 page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
1725                 if (PageHighMem(page)) {
1726                         /* Highmem pages are copied to the buffer,
1727                          * because we can't return with a kmapped
1728                          * highmem page (we may not be called again).
1729                          */
1730                         void *kaddr;
1731 
1732                         kaddr = kmap_atomic(page);
1733                         copy_page(buffer, kaddr);
1734                         kunmap_atomic(kaddr);
1735                         handle->buffer = buffer;
1736                 } else {
1737                         handle->buffer = page_address(page);
1738                 }
1739         }
1740         handle->cur++;
1741         return PAGE_SIZE;
1742 }
1743 
1744 /**
1745  *      mark_unsafe_pages - mark the pages that cannot be used for storing
1746  *      the image during resume, because they conflict with the pages that
1747  *      had been used before suspend
1748  */
1749 
1750 static int mark_unsafe_pages(struct memory_bitmap *bm)
1751 {
1752         struct zone *zone;
1753         unsigned long pfn, max_zone_pfn;
1754 
1755         /* Clear page flags */
1756         for_each_populated_zone(zone) {
1757                 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1758                 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1759                         if (pfn_valid(pfn))
1760                                 swsusp_unset_page_free(pfn_to_page(pfn));
1761         }
1762 
1763         /* Mark pages that correspond to the "original" pfns as "unsafe" */
1764         memory_bm_position_reset(bm);
1765         do {
1766                 pfn = memory_bm_next_pfn(bm);
1767                 if (likely(pfn != BM_END_OF_MAP)) {
1768                         if (likely(pfn_valid(pfn)))
1769                                 swsusp_set_page_free(pfn_to_page(pfn));
1770                         else
1771                                 return -EFAULT;
1772                 }
1773         } while (pfn != BM_END_OF_MAP);
1774 
1775         allocated_unsafe_pages = 0;
1776 
1777         return 0;
1778 }
1779 
1780 static void
1781 duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
1782 {
1783         unsigned long pfn;
1784 
1785         memory_bm_position_reset(src);
1786         pfn = memory_bm_next_pfn(src);
1787         while (pfn != BM_END_OF_MAP) {
1788                 memory_bm_set_bit(dst, pfn);
1789                 pfn = memory_bm_next_pfn(src);
1790         }
1791 }
1792 
1793 static int check_header(struct swsusp_info *info)
1794 {
1795         char *reason;
1796 
1797         reason = check_image_kernel(info);
1798         if (!reason && info->num_physpages != num_physpages)
1799                 reason = "memory size";
1800         if (reason) {
1801                 printk(KERN_ERR "PM: Image mismatch: %s\n", reason);
1802                 return -EPERM;
1803         }
1804         return 0;
1805 }
1806 
1807 /**
1808  *      load header - check the image header and copy data from it
1809  */
1810 
1811 static int
1812 load_header(struct swsusp_info *info)
1813 {
1814         int error;
1815 
1816         restore_pblist = NULL;
1817         error = check_header(info);
1818         if (!error) {
1819                 nr_copy_pages = info->image_pages;
1820                 nr_meta_pages = info->pages - info->image_pages - 1;
1821         }
1822         return error;
1823 }
1824 
1825 /**
1826  *      unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
1827  *      the corresponding bit in the memory bitmap @bm
1828  */
1829 static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
1830 {
1831         int j;
1832 
1833         for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
1834                 if (unlikely(buf[j] == BM_END_OF_MAP))
1835                         break;
1836 
1837                 /* Extract and buffer page key for data page (s390 only). */
1838                 page_key_memorize(buf + j);
1839 
1840                 if (memory_bm_pfn_present(bm, buf[j]))
1841                         memory_bm_set_bit(bm, buf[j]);
1842                 else
1843                         return -EFAULT;
1844         }
1845 
1846         return 0;
1847 }
1848 
1849 /* List of "safe" pages that may be used to store data loaded from the suspend
1850  * image
1851  */
1852 static struct linked_page *safe_pages_list;
1853 
1854 #ifdef CONFIG_HIGHMEM
1855 /* struct highmem_pbe is used for creating the list of highmem pages that
1856  * should be restored atomically during the resume from disk, because the page
1857  * frames they have occupied before the suspend are in use.
1858  */
1859 struct highmem_pbe {
1860         struct page *copy_page; /* data is here now */
1861         struct page *orig_page; /* data was here before the suspend */
1862         struct highmem_pbe *next;
1863 };
1864 
1865 /* List of highmem PBEs needed for restoring the highmem pages that were
1866  * allocated before the suspend and included in the suspend image, but have
1867  * also been allocated by the "resume" kernel, so their contents cannot be
1868  * written directly to their "original" page frames.
1869  */
1870 static struct highmem_pbe *highmem_pblist;
1871 
1872 /**
1873  *      count_highmem_image_pages - compute the number of highmem pages in the
1874  *      suspend image.  The bits in the memory bitmap @bm that correspond to the
1875  *      image pages are assumed to be set.
1876  */
1877 
1878 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
1879 {
1880         unsigned long pfn;
1881         unsigned int cnt = 0;
1882 
1883         memory_bm_position_reset(bm);
1884         pfn = memory_bm_next_pfn(bm);
1885         while (pfn != BM_END_OF_MAP) {
1886                 if (PageHighMem(pfn_to_page(pfn)))
1887                         cnt++;
1888 
1889                 pfn = memory_bm_next_pfn(bm);
1890         }
1891         return cnt;
1892 }
1893 
1894 /**
1895  *      prepare_highmem_image - try to allocate as many highmem pages as
1896  *      there are highmem image pages (@nr_highmem_p points to the variable
1897  *      containing the number of highmem image pages).  The pages that are
1898  *      "safe" (ie. will not be overwritten when the suspend image is
1899  *      restored) have the corresponding bits set in @bm (it must be
1900  *      unitialized).
1901  *
1902  *      NOTE: This function should not be called if there are no highmem
1903  *      image pages.
1904  */
1905 
1906 static unsigned int safe_highmem_pages;
1907 
1908 static struct memory_bitmap *safe_highmem_bm;
1909 
1910 static int
1911 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
1912 {
1913         unsigned int to_alloc;
1914 
1915         if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
1916                 return -ENOMEM;
1917 
1918         if (get_highmem_buffer(PG_SAFE))
1919                 return -ENOMEM;
1920 
1921         to_alloc = count_free_highmem_pages();
1922         if (to_alloc > *nr_highmem_p)
1923                 to_alloc = *nr_highmem_p;
1924         else
1925                 *nr_highmem_p = to_alloc;
1926 
1927         safe_highmem_pages = 0;
1928         while (to_alloc-- > 0) {
1929                 struct page *page;
1930 
1931                 page = alloc_page(__GFP_HIGHMEM);
1932                 if (!swsusp_page_is_free(page)) {
1933                         /* The page is "safe", set its bit the bitmap */
1934                         memory_bm_set_bit(bm, page_to_pfn(page));
1935                         safe_highmem_pages++;
1936                 }
1937                 /* Mark the page as allocated */
1938                 swsusp_set_page_forbidden(page);
1939                 swsusp_set_page_free(page);
1940         }
1941         memory_bm_position_reset(bm);
1942         safe_highmem_bm = bm;
1943         return 0;
1944 }
1945 
1946 /**
1947  *      get_highmem_page_buffer - for given highmem image page find the buffer
1948  *      that suspend_write_next() should set for its caller to write to.
1949  *
1950  *      If the page is to be saved to its "original" page frame or a copy of
1951  *      the page is to be made in the highmem, @buffer is returned.  Otherwise,
1952  *      the copy of the page is to be made in normal memory, so the address of
1953  *      the copy is returned.
1954  *
1955  *      If @buffer is returned, the caller of suspend_write_next() will write
1956  *      the page's contents to @buffer, so they will have to be copied to the
1957  *      right location on the next call to suspend_write_next() and it is done
1958  *      with the help of copy_last_highmem_page().  For this purpose, if
1959  *      @buffer is returned, @last_highmem page is set to the page to which
1960  *      the data will have to be copied from @buffer.
1961  */
1962 
1963 static struct page *last_highmem_page;
1964 
1965 static void *
1966 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
1967 {
1968         struct highmem_pbe *pbe;
1969         void *kaddr;
1970 
1971         if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
1972                 /* We have allocated the "original" page frame and we can
1973                  * use it directly to store the loaded page.
1974                  */
1975                 last_highmem_page = page;
1976                 return buffer;
1977         }
1978         /* The "original" page frame has not been allocated and we have to
1979          * use a "safe" page frame to store the loaded page.
1980          */
1981         pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
1982         if (!pbe) {
1983                 swsusp_free();
1984                 return ERR_PTR(-ENOMEM);
1985         }
1986         pbe->orig_page = page;
1987         if (safe_highmem_pages > 0) {
1988                 struct page *tmp;
1989 
1990                 /* Copy of the page will be stored in high memory */
1991                 kaddr = buffer;
1992                 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
1993                 safe_highmem_pages--;
1994                 last_highmem_page = tmp;
1995                 pbe->copy_page = tmp;
1996         } else {
1997                 /* Copy of the page will be stored in normal memory */
1998                 kaddr = safe_pages_list;
1999                 safe_pages_list = safe_pages_list->next;
2000                 pbe->copy_page = virt_to_page(kaddr);
2001         }
2002         pbe->next = highmem_pblist;
2003         highmem_pblist = pbe;
2004         return kaddr;
2005 }
2006 
2007 /**
2008  *      copy_last_highmem_page - copy the contents of a highmem image from
2009  *      @buffer, where the caller of snapshot_write_next() has place them,
2010  *      to the right location represented by @last_highmem_page .
2011  */
2012 
2013 static void copy_last_highmem_page(void)
2014 {
2015         if (last_highmem_page) {
2016                 void *dst;
2017 
2018                 dst = kmap_atomic(last_highmem_page);
2019                 copy_page(dst, buffer);
2020                 kunmap_atomic(dst);
2021                 last_highmem_page = NULL;
2022         }
2023 }
2024 
2025 static inline int last_highmem_page_copied(void)
2026 {
2027         return !last_highmem_page;
2028 }
2029 
2030 static inline void free_highmem_data(void)
2031 {
2032         if (safe_highmem_bm)
2033                 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2034 
2035         if (buffer)
2036                 free_image_page(buffer, PG_UNSAFE_CLEAR);
2037 }
2038 #else
2039 static inline int get_safe_write_buffer(void) { return 0; }
2040 
2041 static unsigned int
2042 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2043 
2044 static inline int
2045 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
2046 {
2047         return 0;
2048 }
2049 
2050 static inline void *
2051 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
2052 {
2053         return ERR_PTR(-EINVAL);
2054 }
2055 
2056 static inline void copy_last_highmem_page(void) {}
2057 static inline int last_highmem_page_copied(void) { return 1; }
2058 static inline void free_highmem_data(void) {}
2059 #endif /* CONFIG_HIGHMEM */
2060 
2061 /**
2062  *      prepare_image - use the memory bitmap @bm to mark the pages that will
2063  *      be overwritten in the process of restoring the system memory state
2064  *      from the suspend image ("unsafe" pages) and allocate memory for the
2065  *      image.
2066  *
2067  *      The idea is to allocate a new memory bitmap first and then allocate
2068  *      as many pages as needed for the image data, but not to assign these
2069  *      pages to specific tasks initially.  Instead, we just mark them as
2070  *      allocated and create a lists of "safe" pages that will be used
2071  *      later.  On systems with high memory a list of "safe" highmem pages is
2072  *      also created.
2073  */
2074 
2075 #define PBES_PER_LINKED_PAGE    (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2076 
2077 static int
2078 prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2079 {
2080         unsigned int nr_pages, nr_highmem;
2081         struct linked_page *sp_list, *lp;
2082         int error;
2083 
2084         /* If there is no highmem, the buffer will not be necessary */
2085         free_image_page(buffer, PG_UNSAFE_CLEAR);
2086         buffer = NULL;
2087 
2088         nr_highmem = count_highmem_image_pages(bm);
2089         error = mark_unsafe_pages(bm);
2090         if (error)
2091                 goto Free;
2092 
2093         error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2094         if (error)
2095                 goto Free;
2096 
2097         duplicate_memory_bitmap(new_bm, bm);
2098         memory_bm_free(bm, PG_UNSAFE_KEEP);
2099         if (nr_highmem > 0) {
2100                 error = prepare_highmem_image(bm, &nr_highmem);
2101                 if (error)
2102                         goto Free;
2103         }
2104         /* Reserve some safe pages for potential later use.
2105          *
2106          * NOTE: This way we make sure there will be enough safe pages for the
2107          * chain_alloc() in get_buffer().  It is a bit wasteful, but
2108          * nr_copy_pages cannot be greater than 50% of the memory anyway.
2109          */
2110         sp_list = NULL;
2111         /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
2112         nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2113         nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2114         while (nr_pages > 0) {
2115                 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2116                 if (!lp) {
2117                         error = -ENOMEM;
2118                         goto Free;
2119                 }
2120                 lp->next = sp_list;
2121                 sp_list = lp;
2122                 nr_pages--;
2123         }
2124         /* Preallocate memory for the image */
2125         safe_pages_list = NULL;
2126         nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2127         while (nr_pages > 0) {
2128                 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2129                 if (!lp) {
2130                         error = -ENOMEM;
2131                         goto Free;
2132                 }
2133                 if (!swsusp_page_is_free(virt_to_page(lp))) {
2134                         /* The page is "safe", add it to the list */
2135                         lp->next = safe_pages_list;
2136                         safe_pages_list = lp;
2137                 }
2138                 /* Mark the page as allocated */
2139                 swsusp_set_page_forbidden(virt_to_page(lp));
2140                 swsusp_set_page_free(virt_to_page(lp));
2141                 nr_pages--;
2142         }
2143         /* Free the reserved safe pages so that chain_alloc() can use them */
2144         while (sp_list) {
2145                 lp = sp_list->next;
2146                 free_image_page(sp_list, PG_UNSAFE_CLEAR);
2147                 sp_list = lp;
2148         }
2149         return 0;
2150 
2151  Free:
2152         swsusp_free();
2153         return error;
2154 }
2155 
2156 /**
2157  *      get_buffer - compute the address that snapshot_write_next() should
2158  *      set for its caller to write to.
2159  */
2160 
2161 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2162 {
2163         struct pbe *pbe;
2164         struct page *page;
2165         unsigned long pfn = memory_bm_next_pfn(bm);
2166 
2167         if (pfn == BM_END_OF_MAP)
2168                 return ERR_PTR(-EFAULT);
2169 
2170         page = pfn_to_page(pfn);
2171         if (PageHighMem(page))
2172                 return get_highmem_page_buffer(page, ca);
2173 
2174         if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2175                 /* We have allocated the "original" page frame and we can
2176                  * use it directly to store the loaded page.
2177                  */
2178                 return page_address(page);
2179 
2180         /* The "original" page frame has not been allocated and we have to
2181          * use a "safe" page frame to store the loaded page.
2182          */
2183         pbe = chain_alloc(ca, sizeof(struct pbe));
2184         if (!pbe) {
2185                 swsusp_free();
2186                 return ERR_PTR(-ENOMEM);
2187         }
2188         pbe->orig_address = page_address(page);
2189         pbe->address = safe_pages_list;
2190         safe_pages_list = safe_pages_list->next;
2191         pbe->next = restore_pblist;
2192         restore_pblist = pbe;
2193         return pbe->address;
2194 }
2195 
2196 /**
2197  *      snapshot_write_next - used for writing the system memory snapshot.
2198  *
2199  *      On the first call to it @handle should point to a zeroed
2200  *      snapshot_handle structure.  The structure gets updated and a pointer
2201  *      to it should be passed to this function every next time.
2202  *
2203  *      On success the function returns a positive number.  Then, the caller
2204  *      is allowed to write up to the returned number of bytes to the memory
2205  *      location computed by the data_of() macro.
2206  *
2207  *      The function returns 0 to indicate the "end of file" condition,
2208  *      and a negative number is returned on error.  In such cases the
2209  *      structure pointed to by @handle is not updated and should not be used
2210  *      any more.
2211  */
2212 
2213 int snapshot_write_next(struct snapshot_handle *handle)
2214 {
2215         static struct chain_allocator ca;
2216         int error = 0;
2217 
2218         /* Check if we have already loaded the entire image */
2219         if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2220                 return 0;
2221 
2222         handle->sync_read = 1;
2223 
2224         if (!handle->cur) {
2225                 if (!buffer)
2226                         /* This makes the buffer be freed by swsusp_free() */
2227                         buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2228 
2229                 if (!buffer)
2230                         return -ENOMEM;
2231 
2232                 handle->buffer = buffer;
2233         } else if (handle->cur == 1) {
2234                 error = load_header(buffer);
2235                 if (error)
2236                         return error;
2237 
2238                 error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
2239                 if (error)
2240                         return error;
2241 
2242                 /* Allocate buffer for page keys. */
2243                 error = page_key_alloc(nr_copy_pages);
2244                 if (error)
2245                         return error;
2246 
2247         } else if (handle->cur <= nr_meta_pages + 1) {
2248                 error = unpack_orig_pfns(buffer, &copy_bm);
2249                 if (error)
2250                         return error;
2251 
2252                 if (handle->cur == nr_meta_pages + 1) {
2253                         error = prepare_image(&orig_bm, &copy_bm);
2254                         if (error)
2255                                 return error;
2256 
2257                         chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2258                         memory_bm_position_reset(&orig_bm);
2259                         restore_pblist = NULL;
2260                         handle->buffer = get_buffer(&orig_bm, &ca);
2261                         handle->sync_read = 0;
2262                         if (IS_ERR(handle->buffer))
2263                                 return PTR_ERR(handle->buffer);
2264                 }
2265         } else {
2266                 copy_last_highmem_page();
2267                 /* Restore page key for data page (s390 only). */
2268                 page_key_write(handle->buffer);
2269                 handle->buffer = get_buffer(&orig_bm, &ca);
2270                 if (IS_ERR(handle->buffer))
2271                         return PTR_ERR(handle->buffer);
2272                 if (handle->buffer != buffer)
2273                         handle->sync_read = 0;
2274         }
2275         handle->cur++;
2276         return PAGE_SIZE;
2277 }
2278 
2279 /**
2280  *      snapshot_write_finalize - must be called after the last call to
2281  *      snapshot_write_next() in case the last page in the image happens
2282  *      to be a highmem page and its contents should be stored in the
2283  *      highmem.  Additionally, it releases the memory that will not be
2284  *      used any more.
2285  */
2286 
2287 void snapshot_write_finalize(struct snapshot_handle *handle)
2288 {
2289         copy_last_highmem_page();
2290         /* Restore page key for data page (s390 only). */
2291         page_key_write(handle->buffer);
2292         page_key_free();
2293         /* Free only if we have loaded the image entirely */
2294         if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2295                 memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
2296                 free_highmem_data();
2297         }
2298 }
2299 
2300 int snapshot_image_loaded(struct snapshot_handle *handle)
2301 {
2302         return !(!nr_copy_pages || !last_highmem_page_copied() ||
2303                         handle->cur <= nr_meta_pages + nr_copy_pages);
2304 }
2305 
2306 #ifdef CONFIG_HIGHMEM
2307 /* Assumes that @buf is ready and points to a "safe" page */
2308 static inline void
2309 swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
2310 {
2311         void *kaddr1, *kaddr2;
2312 
2313         kaddr1 = kmap_atomic(p1);
2314         kaddr2 = kmap_atomic(p2);
2315         copy_page(buf, kaddr1);
2316         copy_page(kaddr1, kaddr2);
2317         copy_page(kaddr2, buf);
2318         kunmap_atomic(kaddr2);
2319         kunmap_atomic(kaddr1);
2320 }
2321 
2322 /**
2323  *      restore_highmem - for each highmem page that was allocated before
2324  *      the suspend and included in the suspend image, and also has been
2325  *      allocated by the "resume" kernel swap its current (ie. "before
2326  *      resume") contents with the previous (ie. "before suspend") one.
2327  *
2328  *      If the resume eventually fails, we can call this function once
2329  *      again and restore the "before resume" highmem state.
2330  */
2331 
2332 int restore_highmem(void)
2333 {
2334         struct highmem_pbe *pbe = highmem_pblist;
2335         void *buf;
2336 
2337         if (!pbe)
2338                 return 0;
2339 
2340         buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2341         if (!buf)
2342                 return -ENOMEM;
2343 
2344         while (pbe) {
2345                 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2346                 pbe = pbe->next;
2347         }
2348         free_image_page(buf, PG_UNSAFE_CLEAR);
2349         return 0;
2350 }
2351 #endif /* CONFIG_HIGHMEM */
2352 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp