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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(®ion->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: %016lx - %016lx\n", | |
715 | region->start_pfn << PAGE_SHIFT, | |
716 | region->end_pfn << PAGE_SHIFT); | |
717 | ||
718 | for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++) | |
719 | if (pfn_valid(pfn)) { | |
720 | /* | |
721 | * It is safe to ignore the result of | |
722 | * mem_bm_set_bit_check() here, since we won't | |
723 | * touch the PFNs for which the error is | |
724 | * returned anyway. | |
725 | */ | |
726 | mem_bm_set_bit_check(bm, pfn); | |
727 | } | |
728 | } | |
729 | } | |
730 | ||
731 | /** | |
732 | * create_basic_memory_bitmaps - create bitmaps needed for marking page | |
733 | * frames that should not be saved and free page frames. The pointers | |
734 | * forbidden_pages_map and free_pages_map are only modified if everything | |
735 | * goes well, because we don't want the bits to be used before both bitmaps | |
736 | * are set up. | |
737 | */ | |
738 | ||
739 | int create_basic_memory_bitmaps(void) | |
740 | { | |
741 | struct memory_bitmap *bm1, *bm2; | |
742 | int error = 0; | |
743 | ||
744 | BUG_ON(forbidden_pages_map || free_pages_map); | |
745 | ||
746 | bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); | |
747 | if (!bm1) | |
748 | return -ENOMEM; | |
749 | ||
750 | error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY); | |
751 | if (error) | |
752 | goto Free_first_object; | |
753 | ||
754 | bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); | |
755 | if (!bm2) | |
756 | goto Free_first_bitmap; | |
757 | ||
758 | error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY); | |
759 | if (error) | |
760 | goto Free_second_object; | |
761 | ||
762 | forbidden_pages_map = bm1; | |
763 | free_pages_map = bm2; | |
764 | mark_nosave_pages(forbidden_pages_map); | |
765 | ||
766 | pr_debug("PM: Basic memory bitmaps created\n"); | |
767 | ||
768 | return 0; | |
769 | ||
770 | Free_second_object: | |
771 | kfree(bm2); | |
772 | Free_first_bitmap: | |
773 | memory_bm_free(bm1, PG_UNSAFE_CLEAR); | |
774 | Free_first_object: | |
775 | kfree(bm1); | |
776 | return -ENOMEM; | |
777 | } | |
778 | ||
779 | /** | |
780 | * free_basic_memory_bitmaps - free memory bitmaps allocated by | |
781 | * create_basic_memory_bitmaps(). The auxiliary pointers are necessary | |
782 | * so that the bitmaps themselves are not referred to while they are being | |
783 | * freed. | |
784 | */ | |
785 | ||
786 | void free_basic_memory_bitmaps(void) | |
787 | { | |
788 | struct memory_bitmap *bm1, *bm2; | |
789 | ||
790 | BUG_ON(!(forbidden_pages_map && free_pages_map)); | |
791 | ||
792 | bm1 = forbidden_pages_map; | |
793 | bm2 = free_pages_map; | |
794 | forbidden_pages_map = NULL; | |
795 | free_pages_map = NULL; | |
796 | memory_bm_free(bm1, PG_UNSAFE_CLEAR); | |
797 | kfree(bm1); | |
798 | memory_bm_free(bm2, PG_UNSAFE_CLEAR); | |
799 | kfree(bm2); | |
800 | ||
801 | pr_debug("PM: Basic memory bitmaps freed\n"); | |
802 | } | |
803 | ||
804 | /** | |
805 | * snapshot_additional_pages - estimate the number of additional pages | |
806 | * be needed for setting up the suspend image data structures for given | |
807 | * zone (usually the returned value is greater than the exact number) | |
808 | */ | |
809 | ||
810 | unsigned int snapshot_additional_pages(struct zone *zone) | |
811 | { | |
812 | unsigned int res; | |
813 | ||
814 | res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); | |
815 | res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE); | |
816 | return 2 * res; | |
817 | } | |
818 | ||
819 | #ifdef CONFIG_HIGHMEM | |
820 | /** | |
821 | * count_free_highmem_pages - compute the total number of free highmem | |
822 | * pages, system-wide. | |
823 | */ | |
824 | ||
825 | static unsigned int count_free_highmem_pages(void) | |
826 | { | |
827 | struct zone *zone; | |
828 | unsigned int cnt = 0; | |
829 | ||
830 | for_each_populated_zone(zone) | |
831 | if (is_highmem(zone)) | |
832 | cnt += zone_page_state(zone, NR_FREE_PAGES); | |
833 | ||
834 | return cnt; | |
835 | } | |
836 | ||
837 | /** | |
838 | * saveable_highmem_page - Determine whether a highmem page should be | |
839 | * included in the suspend image. | |
840 | * | |
841 | * We should save the page if it isn't Nosave or NosaveFree, or Reserved, | |
842 | * and it isn't a part of a free chunk of pages. | |
843 | */ | |
844 | static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn) | |
845 | { | |
846 | struct page *page; | |
847 | ||
848 | if (!pfn_valid(pfn)) | |
849 | return NULL; | |
850 | ||
851 | page = pfn_to_page(pfn); | |
852 | if (page_zone(page) != zone) | |
853 | return NULL; | |
854 | ||
855 | BUG_ON(!PageHighMem(page)); | |
856 | ||
857 | if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) || | |
858 | PageReserved(page)) | |
859 | return NULL; | |
860 | ||
861 | return page; | |
862 | } | |
863 | ||
864 | /** | |
865 | * count_highmem_pages - compute the total number of saveable highmem | |
866 | * pages. | |
867 | */ | |
868 | ||
869 | static unsigned int count_highmem_pages(void) | |
870 | { | |
871 | struct zone *zone; | |
872 | unsigned int n = 0; | |
873 | ||
874 | for_each_populated_zone(zone) { | |
875 | unsigned long pfn, max_zone_pfn; | |
876 | ||
877 | if (!is_highmem(zone)) | |
878 | continue; | |
879 | ||
880 | mark_free_pages(zone); | |
881 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
882 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
883 | if (saveable_highmem_page(zone, pfn)) | |
884 | n++; | |
885 | } | |
886 | return n; | |
887 | } | |
888 | #else | |
889 | static inline void *saveable_highmem_page(struct zone *z, unsigned long p) | |
890 | { | |
891 | return NULL; | |
892 | } | |
893 | #endif /* CONFIG_HIGHMEM */ | |
894 | ||
895 | /** | |
896 | * saveable_page - Determine whether a non-highmem page should be included | |
897 | * in the suspend image. | |
898 | * | |
899 | * We should save the page if it isn't Nosave, and is not in the range | |
900 | * of pages statically defined as 'unsaveable', and it isn't a part of | |
901 | * a free chunk of pages. | |
902 | */ | |
903 | static struct page *saveable_page(struct zone *zone, unsigned long pfn) | |
904 | { | |
905 | struct page *page; | |
906 | ||
907 | if (!pfn_valid(pfn)) | |
908 | return NULL; | |
909 | ||
910 | page = pfn_to_page(pfn); | |
911 | if (page_zone(page) != zone) | |
912 | return NULL; | |
913 | ||
914 | BUG_ON(PageHighMem(page)); | |
915 | ||
916 | if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) | |
917 | return NULL; | |
918 | ||
919 | if (PageReserved(page) | |
920 | && (!kernel_page_present(page) || pfn_is_nosave(pfn))) | |
921 | return NULL; | |
922 | ||
923 | return page; | |
924 | } | |
925 | ||
926 | /** | |
927 | * count_data_pages - compute the total number of saveable non-highmem | |
928 | * pages. | |
929 | */ | |
930 | ||
931 | static unsigned int count_data_pages(void) | |
932 | { | |
933 | struct zone *zone; | |
934 | unsigned long pfn, max_zone_pfn; | |
935 | unsigned int n = 0; | |
936 | ||
937 | for_each_populated_zone(zone) { | |
938 | if (is_highmem(zone)) | |
939 | continue; | |
940 | ||
941 | mark_free_pages(zone); | |
942 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
943 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
944 | if (saveable_page(zone, pfn)) | |
945 | n++; | |
946 | } | |
947 | return n; | |
948 | } | |
949 | ||
950 | /* This is needed, because copy_page and memcpy are not usable for copying | |
951 | * task structs. | |
952 | */ | |
953 | static inline void do_copy_page(long *dst, long *src) | |
954 | { | |
955 | int n; | |
956 | ||
957 | for (n = PAGE_SIZE / sizeof(long); n; n--) | |
958 | *dst++ = *src++; | |
959 | } | |
960 | ||
961 | ||
962 | /** | |
963 | * safe_copy_page - check if the page we are going to copy is marked as | |
964 | * present in the kernel page tables (this always is the case if | |
965 | * CONFIG_DEBUG_PAGEALLOC is not set and in that case | |
966 | * kernel_page_present() always returns 'true'). | |
967 | */ | |
968 | static void safe_copy_page(void *dst, struct page *s_page) | |
969 | { | |
970 | if (kernel_page_present(s_page)) { | |
971 | do_copy_page(dst, page_address(s_page)); | |
972 | } else { | |
973 | kernel_map_pages(s_page, 1, 1); | |
974 | do_copy_page(dst, page_address(s_page)); | |
975 | kernel_map_pages(s_page, 1, 0); | |
976 | } | |
977 | } | |
978 | ||
979 | ||
980 | #ifdef CONFIG_HIGHMEM | |
981 | static inline struct page * | |
982 | page_is_saveable(struct zone *zone, unsigned long pfn) | |
983 | { | |
984 | return is_highmem(zone) ? | |
985 | saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn); | |
986 | } | |
987 | ||
988 | static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) | |
989 | { | |
990 | struct page *s_page, *d_page; | |
991 | void *src, *dst; | |
992 | ||
993 | s_page = pfn_to_page(src_pfn); | |
994 | d_page = pfn_to_page(dst_pfn); | |
995 | if (PageHighMem(s_page)) { | |
996 | src = kmap_atomic(s_page, KM_USER0); | |
997 | dst = kmap_atomic(d_page, KM_USER1); | |
998 | do_copy_page(dst, src); | |
999 | kunmap_atomic(dst, KM_USER1); | |
1000 | kunmap_atomic(src, KM_USER0); | |
1001 | } else { | |
1002 | if (PageHighMem(d_page)) { | |
1003 | /* Page pointed to by src may contain some kernel | |
1004 | * data modified by kmap_atomic() | |
1005 | */ | |
1006 | safe_copy_page(buffer, s_page); | |
1007 | dst = kmap_atomic(d_page, KM_USER0); | |
1008 | copy_page(dst, buffer); | |
1009 | kunmap_atomic(dst, KM_USER0); | |
1010 | } else { | |
1011 | safe_copy_page(page_address(d_page), s_page); | |
1012 | } | |
1013 | } | |
1014 | } | |
1015 | #else | |
1016 | #define page_is_saveable(zone, pfn) saveable_page(zone, pfn) | |
1017 | ||
1018 | static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) | |
1019 | { | |
1020 | safe_copy_page(page_address(pfn_to_page(dst_pfn)), | |
1021 | pfn_to_page(src_pfn)); | |
1022 | } | |
1023 | #endif /* CONFIG_HIGHMEM */ | |
1024 | ||
1025 | static void | |
1026 | copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) | |
1027 | { | |
1028 | struct zone *zone; | |
1029 | unsigned long pfn; | |
1030 | ||
1031 | for_each_populated_zone(zone) { | |
1032 | unsigned long max_zone_pfn; | |
1033 | ||
1034 | mark_free_pages(zone); | |
1035 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
1036 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
1037 | if (page_is_saveable(zone, pfn)) | |
1038 | memory_bm_set_bit(orig_bm, pfn); | |
1039 | } | |
1040 | memory_bm_position_reset(orig_bm); | |
1041 | memory_bm_position_reset(copy_bm); | |
1042 | for(;;) { | |
1043 | pfn = memory_bm_next_pfn(orig_bm); | |
1044 | if (unlikely(pfn == BM_END_OF_MAP)) | |
1045 | break; | |
1046 | copy_data_page(memory_bm_next_pfn(copy_bm), pfn); | |
1047 | } | |
1048 | } | |
1049 | ||
1050 | /* Total number of image pages */ | |
1051 | static unsigned int nr_copy_pages; | |
1052 | /* Number of pages needed for saving the original pfns of the image pages */ | |
1053 | static unsigned int nr_meta_pages; | |
1054 | /* | |
1055 | * Numbers of normal and highmem page frames allocated for hibernation image | |
1056 | * before suspending devices. | |
1057 | */ | |
1058 | unsigned int alloc_normal, alloc_highmem; | |
1059 | /* | |
1060 | * Memory bitmap used for marking saveable pages (during hibernation) or | |
1061 | * hibernation image pages (during restore) | |
1062 | */ | |
1063 | static struct memory_bitmap orig_bm; | |
1064 | /* | |
1065 | * Memory bitmap used during hibernation for marking allocated page frames that | |
1066 | * will contain copies of saveable pages. During restore it is initially used | |
1067 | * for marking hibernation image pages, but then the set bits from it are | |
1068 | * duplicated in @orig_bm and it is released. On highmem systems it is next | |
1069 | * used for marking "safe" highmem pages, but it has to be reinitialized for | |
1070 | * this purpose. | |
1071 | */ | |
1072 | static struct memory_bitmap copy_bm; | |
1073 | ||
1074 | /** | |
1075 | * swsusp_free - free pages allocated for the suspend. | |
1076 | * | |
1077 | * Suspend pages are alocated before the atomic copy is made, so we | |
1078 | * need to release them after the resume. | |
1079 | */ | |
1080 | ||
1081 | void swsusp_free(void) | |
1082 | { | |
1083 | struct zone *zone; | |
1084 | unsigned long pfn, max_zone_pfn; | |
1085 | ||
1086 | for_each_populated_zone(zone) { | |
1087 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
1088 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
1089 | if (pfn_valid(pfn)) { | |
1090 | struct page *page = pfn_to_page(pfn); | |
1091 | ||
1092 | if (swsusp_page_is_forbidden(page) && | |
1093 | swsusp_page_is_free(page)) { | |
1094 | swsusp_unset_page_forbidden(page); | |
1095 | swsusp_unset_page_free(page); | |
1096 | __free_page(page); | |
1097 | } | |
1098 | } | |
1099 | } | |
1100 | nr_copy_pages = 0; | |
1101 | nr_meta_pages = 0; | |
1102 | restore_pblist = NULL; | |
1103 | buffer = NULL; | |
1104 | alloc_normal = 0; | |
1105 | alloc_highmem = 0; | |
1106 | } | |
1107 | ||
1108 | /* Helper functions used for the shrinking of memory. */ | |
1109 | ||
1110 | #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN) | |
1111 | ||
1112 | /** | |
1113 | * preallocate_image_pages - Allocate a number of pages for hibernation image | |
1114 | * @nr_pages: Number of page frames to allocate. | |
1115 | * @mask: GFP flags to use for the allocation. | |
1116 | * | |
1117 | * Return value: Number of page frames actually allocated | |
1118 | */ | |
1119 | static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask) | |
1120 | { | |
1121 | unsigned long nr_alloc = 0; | |
1122 | ||
1123 | while (nr_pages > 0) { | |
1124 | struct page *page; | |
1125 | ||
1126 | page = alloc_image_page(mask); | |
1127 | if (!page) | |
1128 | break; | |
1129 | memory_bm_set_bit(©_bm, page_to_pfn(page)); | |
1130 | if (PageHighMem(page)) | |
1131 | alloc_highmem++; | |
1132 | else | |
1133 | alloc_normal++; | |
1134 | nr_pages--; | |
1135 | nr_alloc++; | |
1136 | } | |
1137 | ||
1138 | return nr_alloc; | |
1139 | } | |
1140 | ||
1141 | static unsigned long preallocate_image_memory(unsigned long nr_pages, | |
1142 | unsigned long avail_normal) | |
1143 | { | |
1144 | unsigned long alloc; | |
1145 | ||
1146 | if (avail_normal <= alloc_normal) | |
1147 | return 0; | |
1148 | ||
1149 | alloc = avail_normal - alloc_normal; | |
1150 | if (nr_pages < alloc) | |
1151 | alloc = nr_pages; | |
1152 | ||
1153 | return preallocate_image_pages(alloc, GFP_IMAGE); | |
1154 | } | |
1155 | ||
1156 | #ifdef CONFIG_HIGHMEM | |
1157 | static unsigned long preallocate_image_highmem(unsigned long nr_pages) | |
1158 | { | |
1159 | return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM); | |
1160 | } | |
1161 | ||
1162 | /** | |
1163 | * __fraction - Compute (an approximation of) x * (multiplier / base) | |
1164 | */ | |
1165 | static unsigned long __fraction(u64 x, u64 multiplier, u64 base) | |
1166 | { | |
1167 | x *= multiplier; | |
1168 | do_div(x, base); | |
1169 | return (unsigned long)x; | |
1170 | } | |
1171 | ||
1172 | static unsigned long preallocate_highmem_fraction(unsigned long nr_pages, | |
1173 | unsigned long highmem, | |
1174 | unsigned long total) | |
1175 | { | |
1176 | unsigned long alloc = __fraction(nr_pages, highmem, total); | |
1177 | ||
1178 | return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM); | |
1179 | } | |
1180 | #else /* CONFIG_HIGHMEM */ | |
1181 | static inline unsigned long preallocate_image_highmem(unsigned long nr_pages) | |
1182 | { | |
1183 | return 0; | |
1184 | } | |
1185 | ||
1186 | static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, | |
1187 | unsigned long highmem, | |
1188 | unsigned long total) | |
1189 | { | |
1190 | return 0; | |
1191 | } | |
1192 | #endif /* CONFIG_HIGHMEM */ | |
1193 | ||
1194 | /** | |
1195 | * free_unnecessary_pages - Release preallocated pages not needed for the image | |
1196 | */ | |
1197 | static void free_unnecessary_pages(void) | |
1198 | { | |
1199 | unsigned long save, to_free_normal, to_free_highmem; | |
1200 | ||
1201 | save = count_data_pages(); | |
1202 | if (alloc_normal >= save) { | |
1203 | to_free_normal = alloc_normal - save; | |
1204 | save = 0; | |
1205 | } else { | |
1206 | to_free_normal = 0; | |
1207 | save -= alloc_normal; | |
1208 | } | |
1209 | save += count_highmem_pages(); | |
1210 | if (alloc_highmem >= save) { | |
1211 | to_free_highmem = alloc_highmem - save; | |
1212 | } else { | |
1213 | to_free_highmem = 0; | |
1214 | save -= alloc_highmem; | |
1215 | if (to_free_normal > save) | |
1216 | to_free_normal -= save; | |
1217 | else | |
1218 | to_free_normal = 0; | |
1219 | } | |
1220 | ||
1221 | memory_bm_position_reset(©_bm); | |
1222 | ||
1223 | while (to_free_normal > 0 || to_free_highmem > 0) { | |
1224 | unsigned long pfn = memory_bm_next_pfn(©_bm); | |
1225 | struct page *page = pfn_to_page(pfn); | |
1226 | ||
1227 | if (PageHighMem(page)) { | |
1228 | if (!to_free_highmem) | |
1229 | continue; | |
1230 | to_free_highmem--; | |
1231 | alloc_highmem--; | |
1232 | } else { | |
1233 | if (!to_free_normal) | |
1234 | continue; | |
1235 | to_free_normal--; | |
1236 | alloc_normal--; | |
1237 | } | |
1238 | memory_bm_clear_bit(©_bm, pfn); | |
1239 | swsusp_unset_page_forbidden(page); | |
1240 | swsusp_unset_page_free(page); | |
1241 | __free_page(page); | |
1242 | } | |
1243 | } | |
1244 | ||
1245 | /** | |
1246 | * minimum_image_size - Estimate the minimum acceptable size of an image | |
1247 | * @saveable: Number of saveable pages in the system. | |
1248 | * | |
1249 | * We want to avoid attempting to free too much memory too hard, so estimate the | |
1250 | * minimum acceptable size of a hibernation image to use as the lower limit for | |
1251 | * preallocating memory. | |
1252 | * | |
1253 | * We assume that the minimum image size should be proportional to | |
1254 | * | |
1255 | * [number of saveable pages] - [number of pages that can be freed in theory] | |
1256 | * | |
1257 | * where the second term is the sum of (1) reclaimable slab pages, (2) active | |
1258 | * and (3) inactive anonymouns pages, (4) active and (5) inactive file pages, | |
1259 | * minus mapped file pages. | |
1260 | */ | |
1261 | static unsigned long minimum_image_size(unsigned long saveable) | |
1262 | { | |
1263 | unsigned long size; | |
1264 | ||
1265 | size = global_page_state(NR_SLAB_RECLAIMABLE) | |
1266 | + global_page_state(NR_ACTIVE_ANON) | |
1267 | + global_page_state(NR_INACTIVE_ANON) | |
1268 | + global_page_state(NR_ACTIVE_FILE) | |
1269 | + global_page_state(NR_INACTIVE_FILE) | |
1270 | - global_page_state(NR_FILE_MAPPED); | |
1271 | ||
1272 | return saveable <= size ? 0 : saveable - size; | |
1273 | } | |
1274 | ||
1275 | /** | |
1276 | * hibernate_preallocate_memory - Preallocate memory for hibernation image | |
1277 | * | |
1278 | * To create a hibernation image it is necessary to make a copy of every page | |
1279 | * frame in use. We also need a number of page frames to be free during | |
1280 | * hibernation for allocations made while saving the image and for device | |
1281 | * drivers, in case they need to allocate memory from their hibernation | |
1282 | * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough | |
1283 | * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through | |
1284 | * /sys/power/reserved_size, respectively). To make this happen, we compute the | |
1285 | * total number of available page frames and allocate at least | |
1286 | * | |
1287 | * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 | |
1288 | * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE) | |
1289 | * | |
1290 | * of them, which corresponds to the maximum size of a hibernation image. | |
1291 | * | |
1292 | * If image_size is set below the number following from the above formula, | |
1293 | * the preallocation of memory is continued until the total number of saveable | |
1294 | * pages in the system is below the requested image size or the minimum | |
1295 | * acceptable image size returned by minimum_image_size(), whichever is greater. | |
1296 | */ | |
1297 | int hibernate_preallocate_memory(void) | |
1298 | { | |
1299 | struct zone *zone; | |
1300 | unsigned long saveable, size, max_size, count, highmem, pages = 0; | |
1301 | unsigned long alloc, save_highmem, pages_highmem, avail_normal; | |
1302 | struct timeval start, stop; | |
1303 | int error; | |
1304 | ||
1305 | printk(KERN_INFO "PM: Preallocating image memory... "); | |
1306 | do_gettimeofday(&start); | |
1307 | ||
1308 | error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); | |
1309 | if (error) | |
1310 | goto err_out; | |
1311 | ||
1312 | error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY); | |
1313 | if (error) | |
1314 | goto err_out; | |
1315 | ||
1316 | alloc_normal = 0; | |
1317 | alloc_highmem = 0; | |
1318 | ||
1319 | /* Count the number of saveable data pages. */ | |
1320 | save_highmem = count_highmem_pages(); | |
1321 | saveable = count_data_pages(); | |
1322 | ||
1323 | /* | |
1324 | * Compute the total number of page frames we can use (count) and the | |
1325 | * number of pages needed for image metadata (size). | |
1326 | */ | |
1327 | count = saveable; | |
1328 | saveable += save_highmem; | |
1329 | highmem = save_highmem; | |
1330 | size = 0; | |
1331 | for_each_populated_zone(zone) { | |
1332 | size += snapshot_additional_pages(zone); | |
1333 | if (is_highmem(zone)) | |
1334 | highmem += zone_page_state(zone, NR_FREE_PAGES); | |
1335 | else | |
1336 | count += zone_page_state(zone, NR_FREE_PAGES); | |
1337 | } | |
1338 | avail_normal = count; | |
1339 | count += highmem; | |
1340 | count -= totalreserve_pages; | |
1341 | ||
1342 | /* Compute the maximum number of saveable pages to leave in memory. */ | |
1343 | max_size = (count - (size + PAGES_FOR_IO)) / 2 | |
1344 | - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); | |
1345 | /* Compute the desired number of image pages specified by image_size. */ | |
1346 | size = DIV_ROUND_UP(image_size, PAGE_SIZE); | |
1347 | if (size > max_size) | |
1348 | size = max_size; | |
1349 | /* | |
1350 | * If the desired number of image pages is at least as large as the | |
1351 | * current number of saveable pages in memory, allocate page frames for | |
1352 | * the image and we're done. | |
1353 | */ | |
1354 | if (size >= saveable) { | |
1355 | pages = preallocate_image_highmem(save_highmem); | |
1356 | pages += preallocate_image_memory(saveable - pages, avail_normal); | |
1357 | goto out; | |
1358 | } | |
1359 | ||
1360 | /* Estimate the minimum size of the image. */ | |
1361 | pages = minimum_image_size(saveable); | |
1362 | /* | |
1363 | * To avoid excessive pressure on the normal zone, leave room in it to | |
1364 | * accommodate an image of the minimum size (unless it's already too | |
1365 | * small, in which case don't preallocate pages from it at all). | |
1366 | */ | |
1367 | if (avail_normal > pages) | |
1368 | avail_normal -= pages; | |
1369 | else | |
1370 | avail_normal = 0; | |
1371 | if (size < pages) | |
1372 | size = min_t(unsigned long, pages, max_size); | |
1373 | ||
1374 | /* | |
1375 | * Let the memory management subsystem know that we're going to need a | |
1376 | * large number of page frames to allocate and make it free some memory. | |
1377 | * NOTE: If this is not done, performance will be hurt badly in some | |
1378 | * test cases. | |
1379 | */ | |
1380 | shrink_all_memory(saveable - size); | |
1381 | ||
1382 | /* | |
1383 | * The number of saveable pages in memory was too high, so apply some | |
1384 | * pressure to decrease it. First, make room for the largest possible | |
1385 | * image and fail if that doesn't work. Next, try to decrease the size | |
1386 | * of the image as much as indicated by 'size' using allocations from | |
1387 | * highmem and non-highmem zones separately. | |
1388 | */ | |
1389 | pages_highmem = preallocate_image_highmem(highmem / 2); | |
1390 | alloc = (count - max_size) - pages_highmem; | |
1391 | pages = preallocate_image_memory(alloc, avail_normal); | |
1392 | if (pages < alloc) { | |
1393 | /* We have exhausted non-highmem pages, try highmem. */ | |
1394 | alloc -= pages; | |
1395 | pages += pages_highmem; | |
1396 | pages_highmem = preallocate_image_highmem(alloc); | |
1397 | if (pages_highmem < alloc) | |
1398 | goto err_out; | |
1399 | pages += pages_highmem; | |
1400 | /* | |
1401 | * size is the desired number of saveable pages to leave in | |
1402 | * memory, so try to preallocate (all memory - size) pages. | |
1403 | */ | |
1404 | alloc = (count - pages) - size; | |
1405 | pages += preallocate_image_highmem(alloc); | |
1406 | } else { | |
1407 | /* | |
1408 | * There are approximately max_size saveable pages at this point | |
1409 | * and we want to reduce this number down to size. | |
1410 | */ | |
1411 | alloc = max_size - size; | |
1412 | size = preallocate_highmem_fraction(alloc, highmem, count); | |
1413 | pages_highmem += size; | |
1414 | alloc -= size; | |
1415 | size = preallocate_image_memory(alloc, avail_normal); | |
1416 | pages_highmem += preallocate_image_highmem(alloc - size); | |
1417 | pages += pages_highmem + size; | |
1418 | } | |
1419 | ||
1420 | /* | |
1421 | * We only need as many page frames for the image as there are saveable | |
1422 | * pages in memory, but we have allocated more. Release the excessive | |
1423 | * ones now. | |
1424 | */ | |
1425 | free_unnecessary_pages(); | |
1426 | ||
1427 | out: | |
1428 | do_gettimeofday(&stop); | |
1429 | printk(KERN_CONT "done (allocated %lu pages)\n", pages); | |
1430 | swsusp_show_speed(&start, &stop, pages, "Allocated"); | |
1431 | ||
1432 | return 0; | |
1433 | ||
1434 | err_out: | |
1435 | printk(KERN_CONT "\n"); | |
1436 | swsusp_free(); | |
1437 | return -ENOMEM; | |
1438 | } | |
1439 | ||
1440 | #ifdef CONFIG_HIGHMEM | |
1441 | /** | |
1442 | * count_pages_for_highmem - compute the number of non-highmem pages | |
1443 | * that will be necessary for creating copies of highmem pages. | |
1444 | */ | |
1445 | ||
1446 | static unsigned int count_pages_for_highmem(unsigned int nr_highmem) | |
1447 | { | |
1448 | unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem; | |
1449 | ||
1450 | if (free_highmem >= nr_highmem) | |
1451 | nr_highmem = 0; | |
1452 | else | |
1453 | nr_highmem -= free_highmem; | |
1454 | ||
1455 | return nr_highmem; | |
1456 | } | |
1457 | #else | |
1458 | static unsigned int | |
1459 | count_pages_for_highmem(unsigned int nr_highmem) { return 0; } | |
1460 | #endif /* CONFIG_HIGHMEM */ | |
1461 | ||
1462 | /** | |
1463 | * enough_free_mem - Make sure we have enough free memory for the | |
1464 | * snapshot image. | |
1465 | */ | |
1466 | ||
1467 | static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) | |
1468 | { | |
1469 | struct zone *zone; | |
1470 | unsigned int free = alloc_normal; | |
1471 | ||
1472 | for_each_populated_zone(zone) | |
1473 | if (!is_highmem(zone)) | |
1474 | free += zone_page_state(zone, NR_FREE_PAGES); | |
1475 | ||
1476 | nr_pages += count_pages_for_highmem(nr_highmem); | |
1477 | pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n", | |
1478 | nr_pages, PAGES_FOR_IO, free); | |
1479 | ||
1480 | return free > nr_pages + PAGES_FOR_IO; | |
1481 | } | |
1482 | ||
1483 | #ifdef CONFIG_HIGHMEM | |
1484 | /** | |
1485 | * get_highmem_buffer - if there are some highmem pages in the suspend | |
1486 | * image, we may need the buffer to copy them and/or load their data. | |
1487 | */ | |
1488 | ||
1489 | static inline int get_highmem_buffer(int safe_needed) | |
1490 | { | |
1491 | buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed); | |
1492 | return buffer ? 0 : -ENOMEM; | |
1493 | } | |
1494 | ||
1495 | /** | |
1496 | * alloc_highmem_image_pages - allocate some highmem pages for the image. | |
1497 | * Try to allocate as many pages as needed, but if the number of free | |
1498 | * highmem pages is lesser than that, allocate them all. | |
1499 | */ | |
1500 | ||
1501 | static inline unsigned int | |
1502 | alloc_highmem_pages(struct memory_bitmap *bm, unsigned int nr_highmem) | |
1503 | { | |
1504 | unsigned int to_alloc = count_free_highmem_pages(); | |
1505 | ||
1506 | if (to_alloc > nr_highmem) | |
1507 | to_alloc = nr_highmem; | |
1508 | ||
1509 | nr_highmem -= to_alloc; | |
1510 | while (to_alloc-- > 0) { | |
1511 | struct page *page; | |
1512 | ||
1513 | page = alloc_image_page(__GFP_HIGHMEM); | |
1514 | memory_bm_set_bit(bm, page_to_pfn(page)); | |
1515 | } | |
1516 | return nr_highmem; | |
1517 | } | |
1518 | #else | |
1519 | static inline int get_highmem_buffer(int safe_needed) { return 0; } | |
1520 | ||
1521 | static inline unsigned int | |
1522 | alloc_highmem_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } | |
1523 | #endif /* CONFIG_HIGHMEM */ | |
1524 | ||
1525 | /** | |
1526 | * swsusp_alloc - allocate memory for the suspend image | |
1527 | * | |
1528 | * We first try to allocate as many highmem pages as there are | |
1529 | * saveable highmem pages in the system. If that fails, we allocate | |
1530 | * non-highmem pages for the copies of the remaining highmem ones. | |
1531 | * | |
1532 | * In this approach it is likely that the copies of highmem pages will | |
1533 | * also be located in the high memory, because of the way in which | |
1534 | * copy_data_pages() works. | |
1535 | */ | |
1536 | ||
1537 | static int | |
1538 | swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, | |
1539 | unsigned int nr_pages, unsigned int nr_highmem) | |
1540 | { | |
1541 | if (nr_highmem > 0) { | |
1542 | if (get_highmem_buffer(PG_ANY)) | |
1543 | goto err_out; | |
1544 | if (nr_highmem > alloc_highmem) { | |
1545 | nr_highmem -= alloc_highmem; | |
1546 | nr_pages += alloc_highmem_pages(copy_bm, nr_highmem); | |
1547 | } | |
1548 | } | |
1549 | if (nr_pages > alloc_normal) { | |
1550 | nr_pages -= alloc_normal; | |
1551 | while (nr_pages-- > 0) { | |
1552 | struct page *page; | |
1553 | ||
1554 | page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); | |
1555 | if (!page) | |
1556 | goto err_out; | |
1557 | memory_bm_set_bit(copy_bm, page_to_pfn(page)); | |
1558 | } | |
1559 | } | |
1560 | ||
1561 | return 0; | |
1562 | ||
1563 | err_out: | |
1564 | swsusp_free(); | |
1565 | return -ENOMEM; | |
1566 | } | |
1567 | ||
1568 | asmlinkage int swsusp_save(void) | |
1569 | { | |
1570 | unsigned int nr_pages, nr_highmem; | |
1571 | ||
1572 | printk(KERN_INFO "PM: Creating hibernation image:\n"); | |
1573 | ||
1574 | drain_local_pages(NULL); | |
1575 | nr_pages = count_data_pages(); | |
1576 | nr_highmem = count_highmem_pages(); | |
1577 | printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem); | |
1578 | ||
1579 | if (!enough_free_mem(nr_pages, nr_highmem)) { | |
1580 | printk(KERN_ERR "PM: Not enough free memory\n"); | |
1581 | return -ENOMEM; | |
1582 | } | |
1583 | ||
1584 | if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) { | |
1585 | printk(KERN_ERR "PM: Memory allocation failed\n"); | |
1586 | return -ENOMEM; | |
1587 | } | |
1588 | ||
1589 | /* During allocating of suspend pagedir, new cold pages may appear. | |
1590 | * Kill them. | |
1591 | */ | |
1592 | drain_local_pages(NULL); | |
1593 | copy_data_pages(©_bm, &orig_bm); | |
1594 | ||
1595 | /* | |
1596 | * End of critical section. From now on, we can write to memory, | |
1597 | * but we should not touch disk. This specially means we must _not_ | |
1598 | * touch swap space! Except we must write out our image of course. | |
1599 | */ | |
1600 | ||
1601 | nr_pages += nr_highmem; | |
1602 | nr_copy_pages = nr_pages; | |
1603 | nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); | |
1604 | ||
1605 | printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n", | |
1606 | nr_pages); | |
1607 | ||
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | #ifndef CONFIG_ARCH_HIBERNATION_HEADER | |
1612 | static int init_header_complete(struct swsusp_info *info) | |
1613 | { | |
1614 | memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname)); | |
1615 | info->version_code = LINUX_VERSION_CODE; | |
1616 | return 0; | |
1617 | } | |
1618 | ||
1619 | static char *check_image_kernel(struct swsusp_info *info) | |
1620 | { | |
1621 | if (info->version_code != LINUX_VERSION_CODE) | |
1622 | return "kernel version"; | |
1623 | if (strcmp(info->uts.sysname,init_utsname()->sysname)) | |
1624 | return "system type"; | |
1625 | if (strcmp(info->uts.release,init_utsname()->release)) | |
1626 | return "kernel release"; | |
1627 | if (strcmp(info->uts.version,init_utsname()->version)) | |
1628 | return "version"; | |
1629 | if (strcmp(info->uts.machine,init_utsname()->machine)) | |
1630 | return "machine"; | |
1631 | return NULL; | |
1632 | } | |
1633 | #endif /* CONFIG_ARCH_HIBERNATION_HEADER */ | |
1634 | ||
1635 | unsigned long snapshot_get_image_size(void) | |
1636 | { | |
1637 | return nr_copy_pages + nr_meta_pages + 1; | |
1638 | } | |
1639 | ||
1640 | static int init_header(struct swsusp_info *info) | |
1641 | { | |
1642 | memset(info, 0, sizeof(struct swsusp_info)); | |
1643 | info->num_physpages = num_physpages; | |
1644 | info->image_pages = nr_copy_pages; | |
1645 | info->pages = snapshot_get_image_size(); | |
1646 | info->size = info->pages; | |
1647 | info->size <<= PAGE_SHIFT; | |
1648 | return init_header_complete(info); | |
1649 | } | |
1650 | ||
1651 | /** | |
1652 | * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm | |
1653 | * are stored in the array @buf[] (1 page at a time) | |
1654 | */ | |
1655 | ||
1656 | static inline void | |
1657 | pack_pfns(unsigned long *buf, struct memory_bitmap *bm) | |
1658 | { | |
1659 | int j; | |
1660 | ||
1661 | for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { | |
1662 | buf[j] = memory_bm_next_pfn(bm); | |
1663 | if (unlikely(buf[j] == BM_END_OF_MAP)) | |
1664 | break; | |
1665 | } | |
1666 | } | |
1667 | ||
1668 | /** | |
1669 | * snapshot_read_next - used for reading the system memory snapshot. | |
1670 | * | |
1671 | * On the first call to it @handle should point to a zeroed | |
1672 | * snapshot_handle structure. The structure gets updated and a pointer | |
1673 | * to it should be passed to this function every next time. | |
1674 | * | |
1675 | * On success the function returns a positive number. Then, the caller | |
1676 | * is allowed to read up to the returned number of bytes from the memory | |
1677 | * location computed by the data_of() macro. | |
1678 | * | |
1679 | * The function returns 0 to indicate the end of data stream condition, | |
1680 | * and a negative number is returned on error. In such cases the | |
1681 | * structure pointed to by @handle is not updated and should not be used | |
1682 | * any more. | |
1683 | */ | |
1684 | ||
1685 | int snapshot_read_next(struct snapshot_handle *handle) | |
1686 | { | |
1687 | if (handle->cur > nr_meta_pages + nr_copy_pages) | |
1688 | return 0; | |
1689 | ||
1690 | if (!buffer) { | |
1691 | /* This makes the buffer be freed by swsusp_free() */ | |
1692 | buffer = get_image_page(GFP_ATOMIC, PG_ANY); | |
1693 | if (!buffer) | |
1694 | return -ENOMEM; | |
1695 | } | |
1696 | if (!handle->cur) { | |
1697 | int error; | |
1698 | ||
1699 | error = init_header((struct swsusp_info *)buffer); | |
1700 | if (error) | |
1701 | return error; | |
1702 | handle->buffer = buffer; | |
1703 | memory_bm_position_reset(&orig_bm); | |
1704 | memory_bm_position_reset(©_bm); | |
1705 | } else if (handle->cur <= nr_meta_pages) { | |
1706 | clear_page(buffer); | |
1707 | pack_pfns(buffer, &orig_bm); | |
1708 | } else { | |
1709 | struct page *page; | |
1710 | ||
1711 | page = pfn_to_page(memory_bm_next_pfn(©_bm)); | |
1712 | if (PageHighMem(page)) { | |
1713 | /* Highmem pages are copied to the buffer, | |
1714 | * because we can't return with a kmapped | |
1715 | * highmem page (we may not be called again). | |
1716 | */ | |
1717 | void *kaddr; | |
1718 | ||
1719 | kaddr = kmap_atomic(page, KM_USER0); | |
1720 | copy_page(buffer, kaddr); | |
1721 | kunmap_atomic(kaddr, KM_USER0); | |
1722 | handle->buffer = buffer; | |
1723 | } else { | |
1724 | handle->buffer = page_address(page); | |
1725 | } | |
1726 | } | |
1727 | handle->cur++; | |
1728 | return PAGE_SIZE; | |
1729 | } | |
1730 | ||
1731 | /** | |
1732 | * mark_unsafe_pages - mark the pages that cannot be used for storing | |
1733 | * the image during resume, because they conflict with the pages that | |
1734 | * had been used before suspend | |
1735 | */ | |
1736 | ||
1737 | static int mark_unsafe_pages(struct memory_bitmap *bm) | |
1738 | { | |
1739 | struct zone *zone; | |
1740 | unsigned long pfn, max_zone_pfn; | |
1741 | ||
1742 | /* Clear page flags */ | |
1743 | for_each_populated_zone(zone) { | |
1744 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
1745 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
1746 | if (pfn_valid(pfn)) | |
1747 | swsusp_unset_page_free(pfn_to_page(pfn)); | |
1748 | } | |
1749 | ||
1750 | /* Mark pages that correspond to the "original" pfns as "unsafe" */ | |
1751 | memory_bm_position_reset(bm); | |
1752 | do { | |
1753 | pfn = memory_bm_next_pfn(bm); | |
1754 | if (likely(pfn != BM_END_OF_MAP)) { | |
1755 | if (likely(pfn_valid(pfn))) | |
1756 | swsusp_set_page_free(pfn_to_page(pfn)); | |
1757 | else | |
1758 | return -EFAULT; | |
1759 | } | |
1760 | } while (pfn != BM_END_OF_MAP); | |
1761 | ||
1762 | allocated_unsafe_pages = 0; | |
1763 | ||
1764 | return 0; | |
1765 | } | |
1766 | ||
1767 | static void | |
1768 | duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src) | |
1769 | { | |
1770 | unsigned long pfn; | |
1771 | ||
1772 | memory_bm_position_reset(src); | |
1773 | pfn = memory_bm_next_pfn(src); | |
1774 | while (pfn != BM_END_OF_MAP) { | |
1775 | memory_bm_set_bit(dst, pfn); | |
1776 | pfn = memory_bm_next_pfn(src); | |
1777 | } | |
1778 | } | |
1779 | ||
1780 | static int check_header(struct swsusp_info *info) | |
1781 | { | |
1782 | char *reason; | |
1783 | ||
1784 | reason = check_image_kernel(info); | |
1785 | if (!reason && info->num_physpages != num_physpages) | |
1786 | reason = "memory size"; | |
1787 | if (reason) { | |
1788 | printk(KERN_ERR "PM: Image mismatch: %s\n", reason); | |
1789 | return -EPERM; | |
1790 | } | |
1791 | return 0; | |
1792 | } | |
1793 | ||
1794 | /** | |
1795 | * load header - check the image header and copy data from it | |
1796 | */ | |
1797 | ||
1798 | static int | |
1799 | load_header(struct swsusp_info *info) | |
1800 | { | |
1801 | int error; | |
1802 | ||
1803 | restore_pblist = NULL; | |
1804 | error = check_header(info); | |
1805 | if (!error) { | |
1806 | nr_copy_pages = info->image_pages; | |
1807 | nr_meta_pages = info->pages - info->image_pages - 1; | |
1808 | } | |
1809 | return error; | |
1810 | } | |
1811 | ||
1812 | /** | |
1813 | * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set | |
1814 | * the corresponding bit in the memory bitmap @bm | |
1815 | */ | |
1816 | static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) | |
1817 | { | |
1818 | int j; | |
1819 | ||
1820 | for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { | |
1821 | if (unlikely(buf[j] == BM_END_OF_MAP)) | |
1822 | break; | |
1823 | ||
1824 | if (memory_bm_pfn_present(bm, buf[j])) | |
1825 | memory_bm_set_bit(bm, buf[j]); | |
1826 | else | |
1827 | return -EFAULT; | |
1828 | } | |
1829 | ||
1830 | return 0; | |
1831 | } | |
1832 | ||
1833 | /* List of "safe" pages that may be used to store data loaded from the suspend | |
1834 | * image | |
1835 | */ | |
1836 | static struct linked_page *safe_pages_list; | |
1837 | ||
1838 | #ifdef CONFIG_HIGHMEM | |
1839 | /* struct highmem_pbe is used for creating the list of highmem pages that | |
1840 | * should be restored atomically during the resume from disk, because the page | |
1841 | * frames they have occupied before the suspend are in use. | |
1842 | */ | |
1843 | struct highmem_pbe { | |
1844 | struct page *copy_page; /* data is here now */ | |
1845 | struct page *orig_page; /* data was here before the suspend */ | |
1846 | struct highmem_pbe *next; | |
1847 | }; | |
1848 | ||
1849 | /* List of highmem PBEs needed for restoring the highmem pages that were | |
1850 | * allocated before the suspend and included in the suspend image, but have | |
1851 | * also been allocated by the "resume" kernel, so their contents cannot be | |
1852 | * written directly to their "original" page frames. | |
1853 | */ | |
1854 | static struct highmem_pbe *highmem_pblist; | |
1855 | ||
1856 | /** | |
1857 | * count_highmem_image_pages - compute the number of highmem pages in the | |
1858 | * suspend image. The bits in the memory bitmap @bm that correspond to the | |
1859 | * image pages are assumed to be set. | |
1860 | */ | |
1861 | ||
1862 | static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) | |
1863 | { | |
1864 | unsigned long pfn; | |
1865 | unsigned int cnt = 0; | |
1866 | ||
1867 | memory_bm_position_reset(bm); | |
1868 | pfn = memory_bm_next_pfn(bm); | |
1869 | while (pfn != BM_END_OF_MAP) { | |
1870 | if (PageHighMem(pfn_to_page(pfn))) | |
1871 | cnt++; | |
1872 | ||
1873 | pfn = memory_bm_next_pfn(bm); | |
1874 | } | |
1875 | return cnt; | |
1876 | } | |
1877 | ||
1878 | /** | |
1879 | * prepare_highmem_image - try to allocate as many highmem pages as | |
1880 | * there are highmem image pages (@nr_highmem_p points to the variable | |
1881 | * containing the number of highmem image pages). The pages that are | |
1882 | * "safe" (ie. will not be overwritten when the suspend image is | |
1883 | * restored) have the corresponding bits set in @bm (it must be | |
1884 | * unitialized). | |
1885 | * | |
1886 | * NOTE: This function should not be called if there are no highmem | |
1887 | * image pages. | |
1888 | */ | |
1889 | ||
1890 | static unsigned int safe_highmem_pages; | |
1891 | ||
1892 | static struct memory_bitmap *safe_highmem_bm; | |
1893 | ||
1894 | static int | |
1895 | prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) | |
1896 | { | |
1897 | unsigned int to_alloc; | |
1898 | ||
1899 | if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE)) | |
1900 | return -ENOMEM; | |
1901 | ||
1902 | if (get_highmem_buffer(PG_SAFE)) | |
1903 | return -ENOMEM; | |
1904 | ||
1905 | to_alloc = count_free_highmem_pages(); | |
1906 | if (to_alloc > *nr_highmem_p) | |
1907 | to_alloc = *nr_highmem_p; | |
1908 | else | |
1909 | *nr_highmem_p = to_alloc; | |
1910 | ||
1911 | safe_highmem_pages = 0; | |
1912 | while (to_alloc-- > 0) { | |
1913 | struct page *page; | |
1914 | ||
1915 | page = alloc_page(__GFP_HIGHMEM); | |
1916 | if (!swsusp_page_is_free(page)) { | |
1917 | /* The page is "safe", set its bit the bitmap */ | |
1918 | memory_bm_set_bit(bm, page_to_pfn(page)); | |
1919 | safe_highmem_pages++; | |
1920 | } | |
1921 | /* Mark the page as allocated */ | |
1922 | swsusp_set_page_forbidden(page); | |
1923 | swsusp_set_page_free(page); | |
1924 | } | |
1925 | memory_bm_position_reset(bm); | |
1926 | safe_highmem_bm = bm; | |
1927 | return 0; | |
1928 | } | |
1929 | ||
1930 | /** | |
1931 | * get_highmem_page_buffer - for given highmem image page find the buffer | |
1932 | * that suspend_write_next() should set for its caller to write to. | |
1933 | * | |
1934 | * If the page is to be saved to its "original" page frame or a copy of | |
1935 | * the page is to be made in the highmem, @buffer is returned. Otherwise, | |
1936 | * the copy of the page is to be made in normal memory, so the address of | |
1937 | * the copy is returned. | |
1938 | * | |
1939 | * If @buffer is returned, the caller of suspend_write_next() will write | |
1940 | * the page's contents to @buffer, so they will have to be copied to the | |
1941 | * right location on the next call to suspend_write_next() and it is done | |
1942 | * with the help of copy_last_highmem_page(). For this purpose, if | |
1943 | * @buffer is returned, @last_highmem page is set to the page to which | |
1944 | * the data will have to be copied from @buffer. | |
1945 | */ | |
1946 | ||
1947 | static struct page *last_highmem_page; | |
1948 | ||
1949 | static void * | |
1950 | get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) | |
1951 | { | |
1952 | struct highmem_pbe *pbe; | |
1953 | void *kaddr; | |
1954 | ||
1955 | if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) { | |
1956 | /* We have allocated the "original" page frame and we can | |
1957 | * use it directly to store the loaded page. | |
1958 | */ | |
1959 | last_highmem_page = page; | |
1960 | return buffer; | |
1961 | } | |
1962 | /* The "original" page frame has not been allocated and we have to | |
1963 | * use a "safe" page frame to store the loaded page. | |
1964 | */ | |
1965 | pbe = chain_alloc(ca, sizeof(struct highmem_pbe)); | |
1966 | if (!pbe) { | |
1967 | swsusp_free(); | |
1968 | return ERR_PTR(-ENOMEM); | |
1969 | } | |
1970 | pbe->orig_page = page; | |
1971 | if (safe_highmem_pages > 0) { | |
1972 | struct page *tmp; | |
1973 | ||
1974 | /* Copy of the page will be stored in high memory */ | |
1975 | kaddr = buffer; | |
1976 | tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm)); | |
1977 | safe_highmem_pages--; | |
1978 | last_highmem_page = tmp; | |
1979 | pbe->copy_page = tmp; | |
1980 | } else { | |
1981 | /* Copy of the page will be stored in normal memory */ | |
1982 | kaddr = safe_pages_list; | |
1983 | safe_pages_list = safe_pages_list->next; | |
1984 | pbe->copy_page = virt_to_page(kaddr); | |
1985 | } | |
1986 | pbe->next = highmem_pblist; | |
1987 | highmem_pblist = pbe; | |
1988 | return kaddr; | |
1989 | } | |
1990 | ||
1991 | /** | |
1992 | * copy_last_highmem_page - copy the contents of a highmem image from | |
1993 | * @buffer, where the caller of snapshot_write_next() has place them, | |
1994 | * to the right location represented by @last_highmem_page . | |
1995 | */ | |
1996 | ||
1997 | static void copy_last_highmem_page(void) | |
1998 | { | |
1999 | if (last_highmem_page) { | |
2000 | void *dst; | |
2001 | ||
2002 | dst = kmap_atomic(last_highmem_page, KM_USER0); | |
2003 | copy_page(dst, buffer); | |
2004 | kunmap_atomic(dst, KM_USER0); | |
2005 | last_highmem_page = NULL; | |
2006 | } | |
2007 | } | |
2008 | ||
2009 | static inline int last_highmem_page_copied(void) | |
2010 | { | |
2011 | return !last_highmem_page; | |
2012 | } | |
2013 | ||
2014 | static inline void free_highmem_data(void) | |
2015 | { | |
2016 | if (safe_highmem_bm) | |
2017 | memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR); | |
2018 | ||
2019 | if (buffer) | |
2020 | free_image_page(buffer, PG_UNSAFE_CLEAR); | |
2021 | } | |
2022 | #else | |
2023 | static inline int get_safe_write_buffer(void) { return 0; } | |
2024 | ||
2025 | static unsigned int | |
2026 | count_highmem_image_pages(struct memory_bitmap *bm) { return 0; } | |
2027 | ||
2028 | static inline int | |
2029 | prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) | |
2030 | { | |
2031 | return 0; | |
2032 | } | |
2033 | ||
2034 | static inline void * | |
2035 | get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) | |
2036 | { | |
2037 | return ERR_PTR(-EINVAL); | |
2038 | } | |
2039 | ||
2040 | static inline void copy_last_highmem_page(void) {} | |
2041 | static inline int last_highmem_page_copied(void) { return 1; } | |
2042 | static inline void free_highmem_data(void) {} | |
2043 | #endif /* CONFIG_HIGHMEM */ | |
2044 | ||
2045 | /** | |
2046 | * prepare_image - use the memory bitmap @bm to mark the pages that will | |
2047 | * be overwritten in the process of restoring the system memory state | |
2048 | * from the suspend image ("unsafe" pages) and allocate memory for the | |
2049 | * image. | |
2050 | * | |
2051 | * The idea is to allocate a new memory bitmap first and then allocate | |
2052 | * as many pages as needed for the image data, but not to assign these | |
2053 | * pages to specific tasks initially. Instead, we just mark them as | |
2054 | * allocated and create a lists of "safe" pages that will be used | |
2055 | * later. On systems with high memory a list of "safe" highmem pages is | |
2056 | * also created. | |
2057 | */ | |
2058 | ||
2059 | #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) | |
2060 | ||
2061 | static int | |
2062 | prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) | |
2063 | { | |
2064 | unsigned int nr_pages, nr_highmem; | |
2065 | struct linked_page *sp_list, *lp; | |
2066 | int error; | |
2067 | ||
2068 | /* If there is no highmem, the buffer will not be necessary */ | |
2069 | free_image_page(buffer, PG_UNSAFE_CLEAR); | |
2070 | buffer = NULL; | |
2071 | ||
2072 | nr_highmem = count_highmem_image_pages(bm); | |
2073 | error = mark_unsafe_pages(bm); | |
2074 | if (error) | |
2075 | goto Free; | |
2076 | ||
2077 | error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE); | |
2078 | if (error) | |
2079 | goto Free; | |
2080 | ||
2081 | duplicate_memory_bitmap(new_bm, bm); | |
2082 | memory_bm_free(bm, PG_UNSAFE_KEEP); | |
2083 | if (nr_highmem > 0) { | |
2084 | error = prepare_highmem_image(bm, &nr_highmem); | |
2085 | if (error) | |
2086 | goto Free; | |
2087 | } | |
2088 | /* Reserve some safe pages for potential later use. | |
2089 | * | |
2090 | * NOTE: This way we make sure there will be enough safe pages for the | |
2091 | * chain_alloc() in get_buffer(). It is a bit wasteful, but | |
2092 | * nr_copy_pages cannot be greater than 50% of the memory anyway. | |
2093 | */ | |
2094 | sp_list = NULL; | |
2095 | /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */ | |
2096 | nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; | |
2097 | nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE); | |
2098 | while (nr_pages > 0) { | |
2099 | lp = get_image_page(GFP_ATOMIC, PG_SAFE); | |
2100 | if (!lp) { | |
2101 | error = -ENOMEM; | |
2102 | goto Free; | |
2103 | } | |
2104 | lp->next = sp_list; | |
2105 | sp_list = lp; | |
2106 | nr_pages--; | |
2107 | } | |
2108 | /* Preallocate memory for the image */ | |
2109 | safe_pages_list = NULL; | |
2110 | nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; | |
2111 | while (nr_pages > 0) { | |
2112 | lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC); | |
2113 | if (!lp) { | |
2114 | error = -ENOMEM; | |
2115 | goto Free; | |
2116 | } | |
2117 | if (!swsusp_page_is_free(virt_to_page(lp))) { | |
2118 | /* The page is "safe", add it to the list */ | |
2119 | lp->next = safe_pages_list; | |
2120 | safe_pages_list = lp; | |
2121 | } | |
2122 | /* Mark the page as allocated */ | |
2123 | swsusp_set_page_forbidden(virt_to_page(lp)); | |
2124 | swsusp_set_page_free(virt_to_page(lp)); | |
2125 | nr_pages--; | |
2126 | } | |
2127 | /* Free the reserved safe pages so that chain_alloc() can use them */ | |
2128 | while (sp_list) { | |
2129 | lp = sp_list->next; | |
2130 | free_image_page(sp_list, PG_UNSAFE_CLEAR); | |
2131 | sp_list = lp; | |
2132 | } | |
2133 | return 0; | |
2134 | ||
2135 | Free: | |
2136 | swsusp_free(); | |
2137 | return error; | |
2138 | } | |
2139 | ||
2140 | /** | |
2141 | * get_buffer - compute the address that snapshot_write_next() should | |
2142 | * set for its caller to write to. | |
2143 | */ | |
2144 | ||
2145 | static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) | |
2146 | { | |
2147 | struct pbe *pbe; | |
2148 | struct page *page; | |
2149 | unsigned long pfn = memory_bm_next_pfn(bm); | |
2150 | ||
2151 | if (pfn == BM_END_OF_MAP) | |
2152 | return ERR_PTR(-EFAULT); | |
2153 | ||
2154 | page = pfn_to_page(pfn); | |
2155 | if (PageHighMem(page)) | |
2156 | return get_highmem_page_buffer(page, ca); | |
2157 | ||
2158 | if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) | |
2159 | /* We have allocated the "original" page frame and we can | |
2160 | * use it directly to store the loaded page. | |
2161 | */ | |
2162 | return page_address(page); | |
2163 | ||
2164 | /* The "original" page frame has not been allocated and we have to | |
2165 | * use a "safe" page frame to store the loaded page. | |
2166 | */ | |
2167 | pbe = chain_alloc(ca, sizeof(struct pbe)); | |
2168 | if (!pbe) { | |
2169 | swsusp_free(); | |
2170 | return ERR_PTR(-ENOMEM); | |
2171 | } | |
2172 | pbe->orig_address = page_address(page); | |
2173 | pbe->address = safe_pages_list; | |
2174 | safe_pages_list = safe_pages_list->next; | |
2175 | pbe->next = restore_pblist; | |
2176 | restore_pblist = pbe; | |
2177 | return pbe->address; | |
2178 | } | |
2179 | ||
2180 | /** | |
2181 | * snapshot_write_next - used for writing the system memory snapshot. | |
2182 | * | |
2183 | * On the first call to it @handle should point to a zeroed | |
2184 | * snapshot_handle structure. The structure gets updated and a pointer | |
2185 | * to it should be passed to this function every next time. | |
2186 | * | |
2187 | * On success the function returns a positive number. Then, the caller | |
2188 | * is allowed to write up to the returned number of bytes to the memory | |
2189 | * location computed by the data_of() macro. | |
2190 | * | |
2191 | * The function returns 0 to indicate the "end of file" condition, | |
2192 | * and a negative number is returned on error. In such cases the | |
2193 | * structure pointed to by @handle is not updated and should not be used | |
2194 | * any more. | |
2195 | */ | |
2196 | ||
2197 | int snapshot_write_next(struct snapshot_handle *handle) | |
2198 | { | |
2199 | static struct chain_allocator ca; | |
2200 | int error = 0; | |
2201 | ||
2202 | /* Check if we have already loaded the entire image */ | |
2203 | if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) | |
2204 | return 0; | |
2205 | ||
2206 | handle->sync_read = 1; | |
2207 | ||
2208 | if (!handle->cur) { | |
2209 | if (!buffer) | |
2210 | /* This makes the buffer be freed by swsusp_free() */ | |
2211 | buffer = get_image_page(GFP_ATOMIC, PG_ANY); | |
2212 | ||
2213 | if (!buffer) | |
2214 | return -ENOMEM; | |
2215 | ||
2216 | handle->buffer = buffer; | |
2217 | } else if (handle->cur == 1) { | |
2218 | error = load_header(buffer); | |
2219 | if (error) | |
2220 | return error; | |
2221 | ||
2222 | error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); | |
2223 | if (error) | |
2224 | return error; | |
2225 | ||
2226 | } else if (handle->cur <= nr_meta_pages + 1) { | |
2227 | error = unpack_orig_pfns(buffer, ©_bm); | |
2228 | if (error) | |
2229 | return error; | |
2230 | ||
2231 | if (handle->cur == nr_meta_pages + 1) { | |
2232 | error = prepare_image(&orig_bm, ©_bm); | |
2233 | if (error) | |
2234 | return error; | |
2235 | ||
2236 | chain_init(&ca, GFP_ATOMIC, PG_SAFE); | |
2237 | memory_bm_position_reset(&orig_bm); | |
2238 | restore_pblist = NULL; | |
2239 | handle->buffer = get_buffer(&orig_bm, &ca); | |
2240 | handle->sync_read = 0; | |
2241 | if (IS_ERR(handle->buffer)) | |
2242 | return PTR_ERR(handle->buffer); | |
2243 | } | |
2244 | } else { | |
2245 | copy_last_highmem_page(); | |
2246 | handle->buffer = get_buffer(&orig_bm, &ca); | |
2247 | if (IS_ERR(handle->buffer)) | |
2248 | return PTR_ERR(handle->buffer); | |
2249 | if (handle->buffer != buffer) | |
2250 | handle->sync_read = 0; | |
2251 | } | |
2252 | handle->cur++; | |
2253 | return PAGE_SIZE; | |
2254 | } | |
2255 | ||
2256 | /** | |
2257 | * snapshot_write_finalize - must be called after the last call to | |
2258 | * snapshot_write_next() in case the last page in the image happens | |
2259 | * to be a highmem page and its contents should be stored in the | |
2260 | * highmem. Additionally, it releases the memory that will not be | |
2261 | * used any more. | |
2262 | */ | |
2263 | ||
2264 | void snapshot_write_finalize(struct snapshot_handle *handle) | |
2265 | { | |
2266 | copy_last_highmem_page(); | |
2267 | /* Free only if we have loaded the image entirely */ | |
2268 | if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) { | |
2269 | memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR); | |
2270 | free_highmem_data(); | |
2271 | } | |
2272 | } | |
2273 | ||
2274 | int snapshot_image_loaded(struct snapshot_handle *handle) | |
2275 | { | |
2276 | return !(!nr_copy_pages || !last_highmem_page_copied() || | |
2277 | handle->cur <= nr_meta_pages + nr_copy_pages); | |
2278 | } | |
2279 | ||
2280 | #ifdef CONFIG_HIGHMEM | |
2281 | /* Assumes that @buf is ready and points to a "safe" page */ | |
2282 | static inline void | |
2283 | swap_two_pages_data(struct page *p1, struct page *p2, void *buf) | |
2284 | { | |
2285 | void *kaddr1, *kaddr2; | |
2286 | ||
2287 | kaddr1 = kmap_atomic(p1, KM_USER0); | |
2288 | kaddr2 = kmap_atomic(p2, KM_USER1); | |
2289 | copy_page(buf, kaddr1); | |
2290 | copy_page(kaddr1, kaddr2); | |
2291 | copy_page(kaddr2, buf); | |
2292 | kunmap_atomic(kaddr2, KM_USER1); | |
2293 | kunmap_atomic(kaddr1, KM_USER0); | |
2294 | } | |
2295 | ||
2296 | /** | |
2297 | * restore_highmem - for each highmem page that was allocated before | |
2298 | * the suspend and included in the suspend image, and also has been | |
2299 | * allocated by the "resume" kernel swap its current (ie. "before | |
2300 | * resume") contents with the previous (ie. "before suspend") one. | |
2301 | * | |
2302 | * If the resume eventually fails, we can call this function once | |
2303 | * again and restore the "before resume" highmem state. | |
2304 | */ | |
2305 | ||
2306 | int restore_highmem(void) | |
2307 | { | |
2308 | struct highmem_pbe *pbe = highmem_pblist; | |
2309 | void *buf; | |
2310 | ||
2311 | if (!pbe) | |
2312 | return 0; | |
2313 | ||
2314 | buf = get_image_page(GFP_ATOMIC, PG_SAFE); | |
2315 | if (!buf) | |
2316 | return -ENOMEM; | |
2317 | ||
2318 | while (pbe) { | |
2319 | swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf); | |
2320 | pbe = pbe->next; | |
2321 | } | |
2322 | free_image_page(buf, PG_UNSAFE_CLEAR); | |
2323 | return 0; | |
2324 | } | |
2325 | #endif /* CONFIG_HIGHMEM */ |