Commit | Line | Data |
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25761b6e | 1 | /* |
96bc7aec | 2 | * linux/kernel/power/snapshot.c |
25761b6e | 3 | * |
8357376d | 4 | * This file provides system snapshot/restore functionality for swsusp. |
25761b6e RW |
5 | * |
6 | * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz> | |
8357376d | 7 | * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> |
25761b6e | 8 | * |
8357376d | 9 | * This file is released under the GPLv2. |
25761b6e RW |
10 | * |
11 | */ | |
12 | ||
f577eb30 | 13 | #include <linux/version.h> |
25761b6e RW |
14 | #include <linux/module.h> |
15 | #include <linux/mm.h> | |
16 | #include <linux/suspend.h> | |
17 | #include <linux/smp_lock.h> | |
25761b6e | 18 | #include <linux/delay.h> |
25761b6e | 19 | #include <linux/bitops.h> |
25761b6e | 20 | #include <linux/spinlock.h> |
25761b6e | 21 | #include <linux/kernel.h> |
25761b6e RW |
22 | #include <linux/pm.h> |
23 | #include <linux/device.h> | |
25761b6e RW |
24 | #include <linux/bootmem.h> |
25 | #include <linux/syscalls.h> | |
26 | #include <linux/console.h> | |
27 | #include <linux/highmem.h> | |
25761b6e RW |
28 | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/mmu_context.h> | |
31 | #include <asm/pgtable.h> | |
32 | #include <asm/tlbflush.h> | |
33 | #include <asm/io.h> | |
34 | ||
25761b6e RW |
35 | #include "power.h" |
36 | ||
8357376d RW |
37 | /* List of PBEs needed for restoring the pages that were allocated before |
38 | * the suspend and included in the suspend image, but have also been | |
39 | * allocated by the "resume" kernel, so their contents cannot be written | |
40 | * directly to their "original" page frames. | |
41 | */ | |
75534b50 RW |
42 | struct pbe *restore_pblist; |
43 | ||
8357376d | 44 | /* Pointer to an auxiliary buffer (1 page) */ |
940864dd | 45 | static void *buffer; |
7088a5c0 | 46 | |
f6143aa6 RW |
47 | /** |
48 | * @safe_needed - on resume, for storing the PBE list and the image, | |
49 | * we can only use memory pages that do not conflict with the pages | |
8357376d RW |
50 | * used before suspend. The unsafe pages have PageNosaveFree set |
51 | * and we count them using unsafe_pages. | |
f6143aa6 | 52 | * |
8357376d RW |
53 | * Each allocated image page is marked as PageNosave and PageNosaveFree |
54 | * so that swsusp_free() can release it. | |
f6143aa6 RW |
55 | */ |
56 | ||
0bcd888d RW |
57 | #define PG_ANY 0 |
58 | #define PG_SAFE 1 | |
59 | #define PG_UNSAFE_CLEAR 1 | |
60 | #define PG_UNSAFE_KEEP 0 | |
61 | ||
940864dd | 62 | static unsigned int allocated_unsafe_pages; |
f6143aa6 | 63 | |
8357376d | 64 | static void *get_image_page(gfp_t gfp_mask, int safe_needed) |
f6143aa6 RW |
65 | { |
66 | void *res; | |
67 | ||
68 | res = (void *)get_zeroed_page(gfp_mask); | |
69 | if (safe_needed) | |
7be98234 | 70 | while (res && swsusp_page_is_free(virt_to_page(res))) { |
f6143aa6 | 71 | /* The page is unsafe, mark it for swsusp_free() */ |
7be98234 | 72 | swsusp_set_page_forbidden(virt_to_page(res)); |
940864dd | 73 | allocated_unsafe_pages++; |
f6143aa6 RW |
74 | res = (void *)get_zeroed_page(gfp_mask); |
75 | } | |
76 | if (res) { | |
7be98234 RW |
77 | swsusp_set_page_forbidden(virt_to_page(res)); |
78 | swsusp_set_page_free(virt_to_page(res)); | |
f6143aa6 RW |
79 | } |
80 | return res; | |
81 | } | |
82 | ||
83 | unsigned long get_safe_page(gfp_t gfp_mask) | |
84 | { | |
8357376d RW |
85 | return (unsigned long)get_image_page(gfp_mask, PG_SAFE); |
86 | } | |
87 | ||
5b6d15de RW |
88 | static struct page *alloc_image_page(gfp_t gfp_mask) |
89 | { | |
8357376d RW |
90 | struct page *page; |
91 | ||
92 | page = alloc_page(gfp_mask); | |
93 | if (page) { | |
7be98234 RW |
94 | swsusp_set_page_forbidden(page); |
95 | swsusp_set_page_free(page); | |
8357376d RW |
96 | } |
97 | return page; | |
f6143aa6 RW |
98 | } |
99 | ||
100 | /** | |
101 | * free_image_page - free page represented by @addr, allocated with | |
8357376d | 102 | * get_image_page (page flags set by it must be cleared) |
f6143aa6 RW |
103 | */ |
104 | ||
105 | static inline void free_image_page(void *addr, int clear_nosave_free) | |
106 | { | |
8357376d RW |
107 | struct page *page; |
108 | ||
109 | BUG_ON(!virt_addr_valid(addr)); | |
110 | ||
111 | page = virt_to_page(addr); | |
112 | ||
7be98234 | 113 | swsusp_unset_page_forbidden(page); |
f6143aa6 | 114 | if (clear_nosave_free) |
7be98234 | 115 | swsusp_unset_page_free(page); |
8357376d RW |
116 | |
117 | __free_page(page); | |
f6143aa6 RW |
118 | } |
119 | ||
b788db79 RW |
120 | /* struct linked_page is used to build chains of pages */ |
121 | ||
122 | #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) | |
123 | ||
124 | struct linked_page { | |
125 | struct linked_page *next; | |
126 | char data[LINKED_PAGE_DATA_SIZE]; | |
127 | } __attribute__((packed)); | |
128 | ||
129 | static inline void | |
130 | free_list_of_pages(struct linked_page *list, int clear_page_nosave) | |
131 | { | |
132 | while (list) { | |
133 | struct linked_page *lp = list->next; | |
134 | ||
135 | free_image_page(list, clear_page_nosave); | |
136 | list = lp; | |
137 | } | |
138 | } | |
139 | ||
140 | /** | |
141 | * struct chain_allocator is used for allocating small objects out of | |
142 | * a linked list of pages called 'the chain'. | |
143 | * | |
144 | * The chain grows each time when there is no room for a new object in | |
145 | * the current page. The allocated objects cannot be freed individually. | |
146 | * It is only possible to free them all at once, by freeing the entire | |
147 | * chain. | |
148 | * | |
149 | * NOTE: The chain allocator may be inefficient if the allocated objects | |
150 | * are not much smaller than PAGE_SIZE. | |
151 | */ | |
152 | ||
153 | struct chain_allocator { | |
154 | struct linked_page *chain; /* the chain */ | |
155 | unsigned int used_space; /* total size of objects allocated out | |
156 | * of the current page | |
157 | */ | |
158 | gfp_t gfp_mask; /* mask for allocating pages */ | |
159 | int safe_needed; /* if set, only "safe" pages are allocated */ | |
160 | }; | |
161 | ||
162 | static void | |
163 | chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed) | |
164 | { | |
165 | ca->chain = NULL; | |
166 | ca->used_space = LINKED_PAGE_DATA_SIZE; | |
167 | ca->gfp_mask = gfp_mask; | |
168 | ca->safe_needed = safe_needed; | |
169 | } | |
170 | ||
171 | static void *chain_alloc(struct chain_allocator *ca, unsigned int size) | |
172 | { | |
173 | void *ret; | |
174 | ||
175 | if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) { | |
176 | struct linked_page *lp; | |
177 | ||
8357376d | 178 | lp = get_image_page(ca->gfp_mask, ca->safe_needed); |
b788db79 RW |
179 | if (!lp) |
180 | return NULL; | |
181 | ||
182 | lp->next = ca->chain; | |
183 | ca->chain = lp; | |
184 | ca->used_space = 0; | |
185 | } | |
186 | ret = ca->chain->data + ca->used_space; | |
187 | ca->used_space += size; | |
188 | return ret; | |
189 | } | |
190 | ||
191 | static void chain_free(struct chain_allocator *ca, int clear_page_nosave) | |
192 | { | |
193 | free_list_of_pages(ca->chain, clear_page_nosave); | |
194 | memset(ca, 0, sizeof(struct chain_allocator)); | |
195 | } | |
196 | ||
197 | /** | |
198 | * Data types related to memory bitmaps. | |
199 | * | |
200 | * Memory bitmap is a structure consiting of many linked lists of | |
201 | * objects. The main list's elements are of type struct zone_bitmap | |
202 | * and each of them corresonds to one zone. For each zone bitmap | |
203 | * object there is a list of objects of type struct bm_block that | |
204 | * represent each blocks of bit chunks in which information is | |
205 | * stored. | |
206 | * | |
207 | * struct memory_bitmap contains a pointer to the main list of zone | |
208 | * bitmap objects, a struct bm_position used for browsing the bitmap, | |
209 | * and a pointer to the list of pages used for allocating all of the | |
210 | * zone bitmap objects and bitmap block objects. | |
211 | * | |
212 | * NOTE: It has to be possible to lay out the bitmap in memory | |
213 | * using only allocations of order 0. Additionally, the bitmap is | |
214 | * designed to work with arbitrary number of zones (this is over the | |
215 | * top for now, but let's avoid making unnecessary assumptions ;-). | |
216 | * | |
217 | * struct zone_bitmap contains a pointer to a list of bitmap block | |
218 | * objects and a pointer to the bitmap block object that has been | |
219 | * most recently used for setting bits. Additionally, it contains the | |
220 | * pfns that correspond to the start and end of the represented zone. | |
221 | * | |
222 | * struct bm_block contains a pointer to the memory page in which | |
223 | * information is stored (in the form of a block of bit chunks | |
224 | * of type unsigned long each). It also contains the pfns that | |
225 | * correspond to the start and end of the represented memory area and | |
226 | * the number of bit chunks in the block. | |
227 | * | |
228 | * NOTE: Memory bitmaps are used for two types of operations only: | |
229 | * "set a bit" and "find the next bit set". Moreover, the searching | |
230 | * is always carried out after all of the "set a bit" operations | |
231 | * on given bitmap. | |
232 | */ | |
233 | ||
234 | #define BM_END_OF_MAP (~0UL) | |
235 | ||
236 | #define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long)) | |
237 | #define BM_BITS_PER_CHUNK (sizeof(long) << 3) | |
238 | #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3) | |
239 | ||
240 | struct bm_block { | |
241 | struct bm_block *next; /* next element of the list */ | |
242 | unsigned long start_pfn; /* pfn represented by the first bit */ | |
243 | unsigned long end_pfn; /* pfn represented by the last bit plus 1 */ | |
244 | unsigned int size; /* number of bit chunks */ | |
245 | unsigned long *data; /* chunks of bits representing pages */ | |
246 | }; | |
247 | ||
248 | struct zone_bitmap { | |
249 | struct zone_bitmap *next; /* next element of the list */ | |
250 | unsigned long start_pfn; /* minimal pfn in this zone */ | |
251 | unsigned long end_pfn; /* maximal pfn in this zone plus 1 */ | |
252 | struct bm_block *bm_blocks; /* list of bitmap blocks */ | |
253 | struct bm_block *cur_block; /* recently used bitmap block */ | |
254 | }; | |
255 | ||
256 | /* strcut bm_position is used for browsing memory bitmaps */ | |
257 | ||
258 | struct bm_position { | |
259 | struct zone_bitmap *zone_bm; | |
260 | struct bm_block *block; | |
261 | int chunk; | |
262 | int bit; | |
263 | }; | |
264 | ||
265 | struct memory_bitmap { | |
266 | struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */ | |
267 | struct linked_page *p_list; /* list of pages used to store zone | |
268 | * bitmap objects and bitmap block | |
269 | * objects | |
270 | */ | |
271 | struct bm_position cur; /* most recently used bit position */ | |
272 | }; | |
273 | ||
274 | /* Functions that operate on memory bitmaps */ | |
275 | ||
276 | static inline void memory_bm_reset_chunk(struct memory_bitmap *bm) | |
277 | { | |
278 | bm->cur.chunk = 0; | |
279 | bm->cur.bit = -1; | |
280 | } | |
281 | ||
282 | static void memory_bm_position_reset(struct memory_bitmap *bm) | |
283 | { | |
284 | struct zone_bitmap *zone_bm; | |
285 | ||
286 | zone_bm = bm->zone_bm_list; | |
287 | bm->cur.zone_bm = zone_bm; | |
288 | bm->cur.block = zone_bm->bm_blocks; | |
289 | memory_bm_reset_chunk(bm); | |
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 | */ | |
297 | ||
298 | static inline struct bm_block * | |
299 | create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca) | |
300 | { | |
301 | struct bm_block *bblist = NULL; | |
302 | ||
303 | while (nr_blocks-- > 0) { | |
304 | struct bm_block *bb; | |
305 | ||
306 | bb = chain_alloc(ca, sizeof(struct bm_block)); | |
307 | if (!bb) | |
308 | return NULL; | |
309 | ||
310 | bb->next = bblist; | |
311 | bblist = bb; | |
312 | } | |
313 | return bblist; | |
314 | } | |
315 | ||
316 | /** | |
317 | * create_zone_bm_list - create a list of zone bitmap objects | |
318 | */ | |
319 | ||
320 | static inline struct zone_bitmap * | |
321 | create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca) | |
322 | { | |
323 | struct zone_bitmap *zbmlist = NULL; | |
324 | ||
325 | while (nr_zones-- > 0) { | |
326 | struct zone_bitmap *zbm; | |
327 | ||
328 | zbm = chain_alloc(ca, sizeof(struct zone_bitmap)); | |
329 | if (!zbm) | |
330 | return NULL; | |
331 | ||
332 | zbm->next = zbmlist; | |
333 | zbmlist = zbm; | |
334 | } | |
335 | return zbmlist; | |
336 | } | |
337 | ||
338 | /** | |
339 | * memory_bm_create - allocate memory for a memory bitmap | |
340 | */ | |
341 | ||
342 | static int | |
343 | memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) | |
344 | { | |
345 | struct chain_allocator ca; | |
346 | struct zone *zone; | |
347 | struct zone_bitmap *zone_bm; | |
348 | struct bm_block *bb; | |
349 | unsigned int nr; | |
350 | ||
351 | chain_init(&ca, gfp_mask, safe_needed); | |
352 | ||
353 | /* Compute the number of zones */ | |
354 | nr = 0; | |
8357376d RW |
355 | for_each_zone(zone) |
356 | if (populated_zone(zone)) | |
b788db79 RW |
357 | nr++; |
358 | ||
359 | /* Allocate the list of zones bitmap objects */ | |
360 | zone_bm = create_zone_bm_list(nr, &ca); | |
361 | bm->zone_bm_list = zone_bm; | |
362 | if (!zone_bm) { | |
363 | chain_free(&ca, PG_UNSAFE_CLEAR); | |
364 | return -ENOMEM; | |
365 | } | |
366 | ||
367 | /* Initialize the zone bitmap objects */ | |
8357376d | 368 | for_each_zone(zone) { |
b788db79 RW |
369 | unsigned long pfn; |
370 | ||
8357376d | 371 | if (!populated_zone(zone)) |
b788db79 RW |
372 | continue; |
373 | ||
374 | zone_bm->start_pfn = zone->zone_start_pfn; | |
375 | zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
376 | /* Allocate the list of bitmap block objects */ | |
377 | nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); | |
378 | bb = create_bm_block_list(nr, &ca); | |
379 | zone_bm->bm_blocks = bb; | |
380 | zone_bm->cur_block = bb; | |
381 | if (!bb) | |
382 | goto Free; | |
383 | ||
384 | nr = zone->spanned_pages; | |
385 | pfn = zone->zone_start_pfn; | |
386 | /* Initialize the bitmap block objects */ | |
387 | while (bb) { | |
388 | unsigned long *ptr; | |
389 | ||
8357376d | 390 | ptr = get_image_page(gfp_mask, safe_needed); |
b788db79 RW |
391 | bb->data = ptr; |
392 | if (!ptr) | |
393 | goto Free; | |
394 | ||
395 | bb->start_pfn = pfn; | |
396 | if (nr >= BM_BITS_PER_BLOCK) { | |
397 | pfn += BM_BITS_PER_BLOCK; | |
398 | bb->size = BM_CHUNKS_PER_BLOCK; | |
399 | nr -= BM_BITS_PER_BLOCK; | |
400 | } else { | |
401 | /* This is executed only once in the loop */ | |
402 | pfn += nr; | |
403 | bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK); | |
404 | } | |
405 | bb->end_pfn = pfn; | |
406 | bb = bb->next; | |
407 | } | |
408 | zone_bm = zone_bm->next; | |
409 | } | |
410 | bm->p_list = ca.chain; | |
411 | memory_bm_position_reset(bm); | |
412 | return 0; | |
413 | ||
59a49335 | 414 | Free: |
b788db79 RW |
415 | bm->p_list = ca.chain; |
416 | memory_bm_free(bm, PG_UNSAFE_CLEAR); | |
417 | return -ENOMEM; | |
418 | } | |
419 | ||
420 | /** | |
421 | * memory_bm_free - free memory occupied by the memory bitmap @bm | |
422 | */ | |
423 | ||
424 | static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) | |
425 | { | |
426 | struct zone_bitmap *zone_bm; | |
427 | ||
428 | /* Free the list of bit blocks for each zone_bitmap object */ | |
429 | zone_bm = bm->zone_bm_list; | |
430 | while (zone_bm) { | |
431 | struct bm_block *bb; | |
432 | ||
433 | bb = zone_bm->bm_blocks; | |
434 | while (bb) { | |
435 | if (bb->data) | |
436 | free_image_page(bb->data, clear_nosave_free); | |
437 | bb = bb->next; | |
438 | } | |
439 | zone_bm = zone_bm->next; | |
440 | } | |
441 | free_list_of_pages(bm->p_list, clear_nosave_free); | |
442 | bm->zone_bm_list = NULL; | |
443 | } | |
444 | ||
445 | /** | |
446 | * memory_bm_set_bit - set the bit in the bitmap @bm that corresponds | |
447 | * to given pfn. The cur_zone_bm member of @bm and the cur_block member | |
448 | * of @bm->cur_zone_bm are updated. | |
449 | * | |
450 | * If the bit cannot be set, the function returns -EINVAL . | |
451 | */ | |
452 | ||
453 | static int | |
454 | memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) | |
455 | { | |
456 | struct zone_bitmap *zone_bm; | |
457 | struct bm_block *bb; | |
458 | ||
459 | /* Check if the pfn is from the current zone */ | |
460 | zone_bm = bm->cur.zone_bm; | |
461 | if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { | |
462 | zone_bm = bm->zone_bm_list; | |
463 | /* We don't assume that the zones are sorted by pfns */ | |
464 | while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { | |
465 | zone_bm = zone_bm->next; | |
466 | if (unlikely(!zone_bm)) | |
467 | return -EINVAL; | |
468 | } | |
469 | bm->cur.zone_bm = zone_bm; | |
470 | } | |
471 | /* Check if the pfn corresponds to the current bitmap block */ | |
472 | bb = zone_bm->cur_block; | |
473 | if (pfn < bb->start_pfn) | |
474 | bb = zone_bm->bm_blocks; | |
475 | ||
476 | while (pfn >= bb->end_pfn) { | |
477 | bb = bb->next; | |
478 | if (unlikely(!bb)) | |
479 | return -EINVAL; | |
480 | } | |
481 | zone_bm->cur_block = bb; | |
482 | pfn -= bb->start_pfn; | |
483 | set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK); | |
484 | return 0; | |
485 | } | |
486 | ||
487 | /* Two auxiliary functions for memory_bm_next_pfn */ | |
488 | ||
489 | /* Find the first set bit in the given chunk, if there is one */ | |
490 | ||
491 | static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p) | |
492 | { | |
493 | bit++; | |
494 | while (bit < BM_BITS_PER_CHUNK) { | |
495 | if (test_bit(bit, chunk_p)) | |
496 | return bit; | |
497 | ||
498 | bit++; | |
499 | } | |
500 | return -1; | |
501 | } | |
502 | ||
503 | /* Find a chunk containing some bits set in given block of bits */ | |
504 | ||
505 | static inline int next_chunk_in_block(int n, struct bm_block *bb) | |
506 | { | |
507 | n++; | |
508 | while (n < bb->size) { | |
509 | if (bb->data[n]) | |
510 | return n; | |
511 | ||
512 | n++; | |
513 | } | |
514 | return -1; | |
515 | } | |
516 | ||
517 | /** | |
518 | * memory_bm_next_pfn - find the pfn that corresponds to the next set bit | |
519 | * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is | |
520 | * returned. | |
521 | * | |
522 | * It is required to run memory_bm_position_reset() before the first call to | |
523 | * this function. | |
524 | */ | |
525 | ||
526 | static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) | |
527 | { | |
528 | struct zone_bitmap *zone_bm; | |
529 | struct bm_block *bb; | |
530 | int chunk; | |
531 | int bit; | |
532 | ||
533 | do { | |
534 | bb = bm->cur.block; | |
535 | do { | |
536 | chunk = bm->cur.chunk; | |
537 | bit = bm->cur.bit; | |
538 | do { | |
539 | bit = next_bit_in_chunk(bit, bb->data + chunk); | |
540 | if (bit >= 0) | |
541 | goto Return_pfn; | |
542 | ||
543 | chunk = next_chunk_in_block(chunk, bb); | |
544 | bit = -1; | |
545 | } while (chunk >= 0); | |
546 | bb = bb->next; | |
547 | bm->cur.block = bb; | |
548 | memory_bm_reset_chunk(bm); | |
549 | } while (bb); | |
550 | zone_bm = bm->cur.zone_bm->next; | |
551 | if (zone_bm) { | |
552 | bm->cur.zone_bm = zone_bm; | |
553 | bm->cur.block = zone_bm->bm_blocks; | |
554 | memory_bm_reset_chunk(bm); | |
555 | } | |
556 | } while (zone_bm); | |
557 | memory_bm_position_reset(bm); | |
558 | return BM_END_OF_MAP; | |
559 | ||
59a49335 | 560 | Return_pfn: |
b788db79 RW |
561 | bm->cur.chunk = chunk; |
562 | bm->cur.bit = bit; | |
563 | return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit; | |
564 | } | |
565 | ||
566 | /** | |
567 | * snapshot_additional_pages - estimate the number of additional pages | |
568 | * be needed for setting up the suspend image data structures for given | |
569 | * zone (usually the returned value is greater than the exact number) | |
570 | */ | |
571 | ||
572 | unsigned int snapshot_additional_pages(struct zone *zone) | |
573 | { | |
574 | unsigned int res; | |
575 | ||
576 | res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); | |
577 | res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE); | |
8357376d | 578 | return 2 * res; |
b788db79 RW |
579 | } |
580 | ||
8357376d RW |
581 | #ifdef CONFIG_HIGHMEM |
582 | /** | |
583 | * count_free_highmem_pages - compute the total number of free highmem | |
584 | * pages, system-wide. | |
585 | */ | |
586 | ||
587 | static unsigned int count_free_highmem_pages(void) | |
588 | { | |
589 | struct zone *zone; | |
590 | unsigned int cnt = 0; | |
591 | ||
592 | for_each_zone(zone) | |
593 | if (populated_zone(zone) && is_highmem(zone)) | |
d23ad423 | 594 | cnt += zone_page_state(zone, NR_FREE_PAGES); |
8357376d RW |
595 | |
596 | return cnt; | |
597 | } | |
598 | ||
599 | /** | |
600 | * saveable_highmem_page - Determine whether a highmem page should be | |
601 | * included in the suspend image. | |
602 | * | |
603 | * We should save the page if it isn't Nosave or NosaveFree, or Reserved, | |
604 | * and it isn't a part of a free chunk of pages. | |
605 | */ | |
606 | ||
607 | static struct page *saveable_highmem_page(unsigned long pfn) | |
608 | { | |
609 | struct page *page; | |
610 | ||
611 | if (!pfn_valid(pfn)) | |
612 | return NULL; | |
613 | ||
614 | page = pfn_to_page(pfn); | |
615 | ||
616 | BUG_ON(!PageHighMem(page)); | |
617 | ||
7be98234 RW |
618 | if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) || |
619 | PageReserved(page)) | |
8357376d RW |
620 | return NULL; |
621 | ||
622 | return page; | |
623 | } | |
624 | ||
625 | /** | |
626 | * count_highmem_pages - compute the total number of saveable highmem | |
627 | * pages. | |
628 | */ | |
629 | ||
630 | unsigned int count_highmem_pages(void) | |
631 | { | |
632 | struct zone *zone; | |
633 | unsigned int n = 0; | |
634 | ||
635 | for_each_zone(zone) { | |
636 | unsigned long pfn, max_zone_pfn; | |
637 | ||
638 | if (!is_highmem(zone)) | |
639 | continue; | |
640 | ||
641 | mark_free_pages(zone); | |
642 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
643 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
644 | if (saveable_highmem_page(pfn)) | |
645 | n++; | |
646 | } | |
647 | return n; | |
648 | } | |
649 | #else | |
650 | static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; } | |
651 | static inline unsigned int count_highmem_pages(void) { return 0; } | |
652 | #endif /* CONFIG_HIGHMEM */ | |
653 | ||
25761b6e | 654 | /** |
8357376d RW |
655 | * saveable - Determine whether a non-highmem page should be included in |
656 | * the suspend image. | |
25761b6e | 657 | * |
8357376d RW |
658 | * We should save the page if it isn't Nosave, and is not in the range |
659 | * of pages statically defined as 'unsaveable', and it isn't a part of | |
660 | * a free chunk of pages. | |
25761b6e RW |
661 | */ |
662 | ||
ae83c5ee | 663 | static struct page *saveable_page(unsigned long pfn) |
25761b6e | 664 | { |
de491861 | 665 | struct page *page; |
25761b6e RW |
666 | |
667 | if (!pfn_valid(pfn)) | |
ae83c5ee | 668 | return NULL; |
25761b6e RW |
669 | |
670 | page = pfn_to_page(pfn); | |
ae83c5ee | 671 | |
8357376d RW |
672 | BUG_ON(PageHighMem(page)); |
673 | ||
7be98234 | 674 | if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) |
ae83c5ee | 675 | return NULL; |
8357376d | 676 | |
72a97e08 | 677 | if (PageReserved(page) && pfn_is_nosave(pfn)) |
ae83c5ee | 678 | return NULL; |
25761b6e | 679 | |
ae83c5ee | 680 | return page; |
25761b6e RW |
681 | } |
682 | ||
8357376d RW |
683 | /** |
684 | * count_data_pages - compute the total number of saveable non-highmem | |
685 | * pages. | |
686 | */ | |
687 | ||
72a97e08 | 688 | unsigned int count_data_pages(void) |
25761b6e RW |
689 | { |
690 | struct zone *zone; | |
ae83c5ee | 691 | unsigned long pfn, max_zone_pfn; |
dc19d507 | 692 | unsigned int n = 0; |
25761b6e | 693 | |
8357376d | 694 | for_each_zone(zone) { |
25761b6e RW |
695 | if (is_highmem(zone)) |
696 | continue; | |
8357376d | 697 | |
25761b6e | 698 | mark_free_pages(zone); |
ae83c5ee RW |
699 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
700 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
8357376d RW |
701 | if(saveable_page(pfn)) |
702 | n++; | |
25761b6e | 703 | } |
a0f49651 | 704 | return n; |
25761b6e RW |
705 | } |
706 | ||
8357376d RW |
707 | /* This is needed, because copy_page and memcpy are not usable for copying |
708 | * task structs. | |
709 | */ | |
710 | static inline void do_copy_page(long *dst, long *src) | |
f623f0db RW |
711 | { |
712 | int n; | |
713 | ||
f623f0db RW |
714 | for (n = PAGE_SIZE / sizeof(long); n; n--) |
715 | *dst++ = *src++; | |
716 | } | |
717 | ||
8357376d RW |
718 | #ifdef CONFIG_HIGHMEM |
719 | static inline struct page * | |
720 | page_is_saveable(struct zone *zone, unsigned long pfn) | |
721 | { | |
722 | return is_highmem(zone) ? | |
723 | saveable_highmem_page(pfn) : saveable_page(pfn); | |
724 | } | |
725 | ||
726 | static inline void | |
727 | copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) | |
728 | { | |
729 | struct page *s_page, *d_page; | |
730 | void *src, *dst; | |
731 | ||
732 | s_page = pfn_to_page(src_pfn); | |
733 | d_page = pfn_to_page(dst_pfn); | |
734 | if (PageHighMem(s_page)) { | |
735 | src = kmap_atomic(s_page, KM_USER0); | |
736 | dst = kmap_atomic(d_page, KM_USER1); | |
737 | do_copy_page(dst, src); | |
738 | kunmap_atomic(src, KM_USER0); | |
739 | kunmap_atomic(dst, KM_USER1); | |
740 | } else { | |
741 | src = page_address(s_page); | |
742 | if (PageHighMem(d_page)) { | |
743 | /* Page pointed to by src may contain some kernel | |
744 | * data modified by kmap_atomic() | |
745 | */ | |
746 | do_copy_page(buffer, src); | |
747 | dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0); | |
748 | memcpy(dst, buffer, PAGE_SIZE); | |
749 | kunmap_atomic(dst, KM_USER0); | |
750 | } else { | |
751 | dst = page_address(d_page); | |
752 | do_copy_page(dst, src); | |
753 | } | |
754 | } | |
755 | } | |
756 | #else | |
757 | #define page_is_saveable(zone, pfn) saveable_page(pfn) | |
758 | ||
759 | static inline void | |
760 | copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) | |
761 | { | |
762 | do_copy_page(page_address(pfn_to_page(dst_pfn)), | |
763 | page_address(pfn_to_page(src_pfn))); | |
764 | } | |
765 | #endif /* CONFIG_HIGHMEM */ | |
766 | ||
b788db79 RW |
767 | static void |
768 | copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) | |
25761b6e RW |
769 | { |
770 | struct zone *zone; | |
b788db79 | 771 | unsigned long pfn; |
25761b6e | 772 | |
8357376d | 773 | for_each_zone(zone) { |
b788db79 RW |
774 | unsigned long max_zone_pfn; |
775 | ||
25761b6e | 776 | mark_free_pages(zone); |
ae83c5ee | 777 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
b788db79 | 778 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) |
8357376d | 779 | if (page_is_saveable(zone, pfn)) |
b788db79 | 780 | memory_bm_set_bit(orig_bm, pfn); |
25761b6e | 781 | } |
b788db79 RW |
782 | memory_bm_position_reset(orig_bm); |
783 | memory_bm_position_reset(copy_bm); | |
784 | do { | |
785 | pfn = memory_bm_next_pfn(orig_bm); | |
8357376d RW |
786 | if (likely(pfn != BM_END_OF_MAP)) |
787 | copy_data_page(memory_bm_next_pfn(copy_bm), pfn); | |
b788db79 | 788 | } while (pfn != BM_END_OF_MAP); |
25761b6e RW |
789 | } |
790 | ||
8357376d RW |
791 | /* Total number of image pages */ |
792 | static unsigned int nr_copy_pages; | |
793 | /* Number of pages needed for saving the original pfns of the image pages */ | |
794 | static unsigned int nr_meta_pages; | |
795 | ||
25761b6e | 796 | /** |
940864dd | 797 | * swsusp_free - free pages allocated for the suspend. |
cd560bb2 | 798 | * |
940864dd RW |
799 | * Suspend pages are alocated before the atomic copy is made, so we |
800 | * need to release them after the resume. | |
25761b6e RW |
801 | */ |
802 | ||
803 | void swsusp_free(void) | |
804 | { | |
805 | struct zone *zone; | |
ae83c5ee | 806 | unsigned long pfn, max_zone_pfn; |
25761b6e RW |
807 | |
808 | for_each_zone(zone) { | |
ae83c5ee RW |
809 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
810 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
811 | if (pfn_valid(pfn)) { | |
812 | struct page *page = pfn_to_page(pfn); | |
813 | ||
7be98234 RW |
814 | if (swsusp_page_is_forbidden(page) && |
815 | swsusp_page_is_free(page)) { | |
816 | swsusp_unset_page_forbidden(page); | |
817 | swsusp_unset_page_free(page); | |
8357376d | 818 | __free_page(page); |
25761b6e RW |
819 | } |
820 | } | |
821 | } | |
f577eb30 RW |
822 | nr_copy_pages = 0; |
823 | nr_meta_pages = 0; | |
75534b50 | 824 | restore_pblist = NULL; |
6e1819d6 | 825 | buffer = NULL; |
25761b6e RW |
826 | } |
827 | ||
8357376d RW |
828 | #ifdef CONFIG_HIGHMEM |
829 | /** | |
830 | * count_pages_for_highmem - compute the number of non-highmem pages | |
831 | * that will be necessary for creating copies of highmem pages. | |
832 | */ | |
833 | ||
834 | static unsigned int count_pages_for_highmem(unsigned int nr_highmem) | |
835 | { | |
836 | unsigned int free_highmem = count_free_highmem_pages(); | |
837 | ||
838 | if (free_highmem >= nr_highmem) | |
839 | nr_highmem = 0; | |
840 | else | |
841 | nr_highmem -= free_highmem; | |
842 | ||
843 | return nr_highmem; | |
844 | } | |
845 | #else | |
846 | static unsigned int | |
847 | count_pages_for_highmem(unsigned int nr_highmem) { return 0; } | |
848 | #endif /* CONFIG_HIGHMEM */ | |
25761b6e RW |
849 | |
850 | /** | |
8357376d RW |
851 | * enough_free_mem - Make sure we have enough free memory for the |
852 | * snapshot image. | |
25761b6e RW |
853 | */ |
854 | ||
8357376d | 855 | static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) |
25761b6e | 856 | { |
e5e2fa78 | 857 | struct zone *zone; |
940864dd | 858 | unsigned int free = 0, meta = 0; |
e5e2fa78 | 859 | |
8357376d RW |
860 | for_each_zone(zone) { |
861 | meta += snapshot_additional_pages(zone); | |
862 | if (!is_highmem(zone)) | |
d23ad423 | 863 | free += zone_page_state(zone, NR_FREE_PAGES); |
8357376d | 864 | } |
940864dd | 865 | |
8357376d RW |
866 | nr_pages += count_pages_for_highmem(nr_highmem); |
867 | pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n", | |
940864dd RW |
868 | nr_pages, PAGES_FOR_IO, meta, free); |
869 | ||
870 | return free > nr_pages + PAGES_FOR_IO + meta; | |
25761b6e RW |
871 | } |
872 | ||
8357376d RW |
873 | #ifdef CONFIG_HIGHMEM |
874 | /** | |
875 | * get_highmem_buffer - if there are some highmem pages in the suspend | |
876 | * image, we may need the buffer to copy them and/or load their data. | |
877 | */ | |
878 | ||
879 | static inline int get_highmem_buffer(int safe_needed) | |
880 | { | |
881 | buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed); | |
882 | return buffer ? 0 : -ENOMEM; | |
883 | } | |
884 | ||
885 | /** | |
886 | * alloc_highmem_image_pages - allocate some highmem pages for the image. | |
887 | * Try to allocate as many pages as needed, but if the number of free | |
888 | * highmem pages is lesser than that, allocate them all. | |
889 | */ | |
890 | ||
891 | static inline unsigned int | |
892 | alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem) | |
893 | { | |
894 | unsigned int to_alloc = count_free_highmem_pages(); | |
895 | ||
896 | if (to_alloc > nr_highmem) | |
897 | to_alloc = nr_highmem; | |
898 | ||
899 | nr_highmem -= to_alloc; | |
900 | while (to_alloc-- > 0) { | |
901 | struct page *page; | |
902 | ||
903 | page = alloc_image_page(__GFP_HIGHMEM); | |
904 | memory_bm_set_bit(bm, page_to_pfn(page)); | |
905 | } | |
906 | return nr_highmem; | |
907 | } | |
908 | #else | |
909 | static inline int get_highmem_buffer(int safe_needed) { return 0; } | |
910 | ||
911 | static inline unsigned int | |
912 | alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } | |
913 | #endif /* CONFIG_HIGHMEM */ | |
914 | ||
915 | /** | |
916 | * swsusp_alloc - allocate memory for the suspend image | |
917 | * | |
918 | * We first try to allocate as many highmem pages as there are | |
919 | * saveable highmem pages in the system. If that fails, we allocate | |
920 | * non-highmem pages for the copies of the remaining highmem ones. | |
921 | * | |
922 | * In this approach it is likely that the copies of highmem pages will | |
923 | * also be located in the high memory, because of the way in which | |
924 | * copy_data_pages() works. | |
925 | */ | |
926 | ||
b788db79 RW |
927 | static int |
928 | swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, | |
8357376d | 929 | unsigned int nr_pages, unsigned int nr_highmem) |
054bd4c1 | 930 | { |
b788db79 | 931 | int error; |
054bd4c1 | 932 | |
b788db79 RW |
933 | error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); |
934 | if (error) | |
935 | goto Free; | |
25761b6e | 936 | |
b788db79 RW |
937 | error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); |
938 | if (error) | |
939 | goto Free; | |
25761b6e | 940 | |
8357376d RW |
941 | if (nr_highmem > 0) { |
942 | error = get_highmem_buffer(PG_ANY); | |
943 | if (error) | |
944 | goto Free; | |
945 | ||
946 | nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem); | |
947 | } | |
b788db79 | 948 | while (nr_pages-- > 0) { |
8357376d RW |
949 | struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); |
950 | ||
b788db79 RW |
951 | if (!page) |
952 | goto Free; | |
25761b6e | 953 | |
b788db79 | 954 | memory_bm_set_bit(copy_bm, page_to_pfn(page)); |
25761b6e | 955 | } |
b788db79 | 956 | return 0; |
25761b6e | 957 | |
59a49335 | 958 | Free: |
b788db79 RW |
959 | swsusp_free(); |
960 | return -ENOMEM; | |
25761b6e RW |
961 | } |
962 | ||
8357376d RW |
963 | /* Memory bitmap used for marking saveable pages (during suspend) or the |
964 | * suspend image pages (during resume) | |
965 | */ | |
b788db79 | 966 | static struct memory_bitmap orig_bm; |
8357376d RW |
967 | /* Memory bitmap used on suspend for marking allocated pages that will contain |
968 | * the copies of saveable pages. During resume it is initially used for | |
969 | * marking the suspend image pages, but then its set bits are duplicated in | |
970 | * @orig_bm and it is released. Next, on systems with high memory, it may be | |
971 | * used for marking "safe" highmem pages, but it has to be reinitialized for | |
972 | * this purpose. | |
b788db79 RW |
973 | */ |
974 | static struct memory_bitmap copy_bm; | |
975 | ||
2e32a43e | 976 | asmlinkage int swsusp_save(void) |
25761b6e | 977 | { |
8357376d | 978 | unsigned int nr_pages, nr_highmem; |
25761b6e | 979 | |
8357376d | 980 | printk("swsusp: critical section: \n"); |
25761b6e RW |
981 | |
982 | drain_local_pages(); | |
a0f49651 | 983 | nr_pages = count_data_pages(); |
8357376d RW |
984 | nr_highmem = count_highmem_pages(); |
985 | printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem); | |
25761b6e | 986 | |
8357376d | 987 | if (!enough_free_mem(nr_pages, nr_highmem)) { |
25761b6e RW |
988 | printk(KERN_ERR "swsusp: Not enough free memory\n"); |
989 | return -ENOMEM; | |
990 | } | |
991 | ||
8357376d RW |
992 | if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) { |
993 | printk(KERN_ERR "swsusp: Memory allocation failed\n"); | |
a0f49651 | 994 | return -ENOMEM; |
8357376d | 995 | } |
25761b6e RW |
996 | |
997 | /* During allocating of suspend pagedir, new cold pages may appear. | |
998 | * Kill them. | |
999 | */ | |
1000 | drain_local_pages(); | |
b788db79 | 1001 | copy_data_pages(©_bm, &orig_bm); |
25761b6e RW |
1002 | |
1003 | /* | |
1004 | * End of critical section. From now on, we can write to memory, | |
1005 | * but we should not touch disk. This specially means we must _not_ | |
1006 | * touch swap space! Except we must write out our image of course. | |
1007 | */ | |
1008 | ||
8357376d | 1009 | nr_pages += nr_highmem; |
a0f49651 | 1010 | nr_copy_pages = nr_pages; |
8357376d | 1011 | nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); |
a0f49651 RW |
1012 | |
1013 | printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); | |
8357376d | 1014 | |
25761b6e RW |
1015 | return 0; |
1016 | } | |
f577eb30 RW |
1017 | |
1018 | static void init_header(struct swsusp_info *info) | |
1019 | { | |
1020 | memset(info, 0, sizeof(struct swsusp_info)); | |
1021 | info->version_code = LINUX_VERSION_CODE; | |
1022 | info->num_physpages = num_physpages; | |
96b644bd | 1023 | memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname)); |
f577eb30 RW |
1024 | info->cpus = num_online_cpus(); |
1025 | info->image_pages = nr_copy_pages; | |
1026 | info->pages = nr_copy_pages + nr_meta_pages + 1; | |
6e1819d6 RW |
1027 | info->size = info->pages; |
1028 | info->size <<= PAGE_SHIFT; | |
f577eb30 RW |
1029 | } |
1030 | ||
1031 | /** | |
940864dd RW |
1032 | * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm |
1033 | * are stored in the array @buf[] (1 page at a time) | |
f577eb30 RW |
1034 | */ |
1035 | ||
b788db79 | 1036 | static inline void |
940864dd | 1037 | pack_pfns(unsigned long *buf, struct memory_bitmap *bm) |
f577eb30 RW |
1038 | { |
1039 | int j; | |
1040 | ||
b788db79 | 1041 | for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { |
940864dd RW |
1042 | buf[j] = memory_bm_next_pfn(bm); |
1043 | if (unlikely(buf[j] == BM_END_OF_MAP)) | |
b788db79 | 1044 | break; |
f577eb30 | 1045 | } |
f577eb30 RW |
1046 | } |
1047 | ||
1048 | /** | |
1049 | * snapshot_read_next - used for reading the system memory snapshot. | |
1050 | * | |
1051 | * On the first call to it @handle should point to a zeroed | |
1052 | * snapshot_handle structure. The structure gets updated and a pointer | |
1053 | * to it should be passed to this function every next time. | |
1054 | * | |
1055 | * The @count parameter should contain the number of bytes the caller | |
1056 | * wants to read from the snapshot. It must not be zero. | |
1057 | * | |
1058 | * On success the function returns a positive number. Then, the caller | |
1059 | * is allowed to read up to the returned number of bytes from the memory | |
1060 | * location computed by the data_of() macro. The number returned | |
1061 | * may be smaller than @count, but this only happens if the read would | |
1062 | * cross a page boundary otherwise. | |
1063 | * | |
1064 | * The function returns 0 to indicate the end of data stream condition, | |
1065 | * and a negative number is returned on error. In such cases the | |
1066 | * structure pointed to by @handle is not updated and should not be used | |
1067 | * any more. | |
1068 | */ | |
1069 | ||
1070 | int snapshot_read_next(struct snapshot_handle *handle, size_t count) | |
1071 | { | |
fb13a28b | 1072 | if (handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 | 1073 | return 0; |
b788db79 | 1074 | |
f577eb30 RW |
1075 | if (!buffer) { |
1076 | /* This makes the buffer be freed by swsusp_free() */ | |
8357376d | 1077 | buffer = get_image_page(GFP_ATOMIC, PG_ANY); |
f577eb30 RW |
1078 | if (!buffer) |
1079 | return -ENOMEM; | |
1080 | } | |
1081 | if (!handle->offset) { | |
1082 | init_header((struct swsusp_info *)buffer); | |
1083 | handle->buffer = buffer; | |
b788db79 RW |
1084 | memory_bm_position_reset(&orig_bm); |
1085 | memory_bm_position_reset(©_bm); | |
f577eb30 | 1086 | } |
fb13a28b RW |
1087 | if (handle->prev < handle->cur) { |
1088 | if (handle->cur <= nr_meta_pages) { | |
b788db79 | 1089 | memset(buffer, 0, PAGE_SIZE); |
940864dd | 1090 | pack_pfns(buffer, &orig_bm); |
f577eb30 | 1091 | } else { |
8357376d | 1092 | struct page *page; |
b788db79 | 1093 | |
8357376d RW |
1094 | page = pfn_to_page(memory_bm_next_pfn(©_bm)); |
1095 | if (PageHighMem(page)) { | |
1096 | /* Highmem pages are copied to the buffer, | |
1097 | * because we can't return with a kmapped | |
1098 | * highmem page (we may not be called again). | |
1099 | */ | |
1100 | void *kaddr; | |
1101 | ||
1102 | kaddr = kmap_atomic(page, KM_USER0); | |
1103 | memcpy(buffer, kaddr, PAGE_SIZE); | |
1104 | kunmap_atomic(kaddr, KM_USER0); | |
1105 | handle->buffer = buffer; | |
1106 | } else { | |
1107 | handle->buffer = page_address(page); | |
1108 | } | |
f577eb30 | 1109 | } |
fb13a28b | 1110 | handle->prev = handle->cur; |
f577eb30 | 1111 | } |
fb13a28b RW |
1112 | handle->buf_offset = handle->cur_offset; |
1113 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
1114 | count = PAGE_SIZE - handle->cur_offset; | |
1115 | handle->cur_offset = 0; | |
1116 | handle->cur++; | |
f577eb30 | 1117 | } else { |
fb13a28b | 1118 | handle->cur_offset += count; |
f577eb30 RW |
1119 | } |
1120 | handle->offset += count; | |
1121 | return count; | |
1122 | } | |
1123 | ||
1124 | /** | |
1125 | * mark_unsafe_pages - mark the pages that cannot be used for storing | |
1126 | * the image during resume, because they conflict with the pages that | |
1127 | * had been used before suspend | |
1128 | */ | |
1129 | ||
940864dd | 1130 | static int mark_unsafe_pages(struct memory_bitmap *bm) |
f577eb30 RW |
1131 | { |
1132 | struct zone *zone; | |
ae83c5ee | 1133 | unsigned long pfn, max_zone_pfn; |
f577eb30 RW |
1134 | |
1135 | /* Clear page flags */ | |
8357376d | 1136 | for_each_zone(zone) { |
ae83c5ee RW |
1137 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
1138 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
1139 | if (pfn_valid(pfn)) | |
7be98234 | 1140 | swsusp_unset_page_free(pfn_to_page(pfn)); |
f577eb30 RW |
1141 | } |
1142 | ||
940864dd RW |
1143 | /* Mark pages that correspond to the "original" pfns as "unsafe" */ |
1144 | memory_bm_position_reset(bm); | |
1145 | do { | |
1146 | pfn = memory_bm_next_pfn(bm); | |
1147 | if (likely(pfn != BM_END_OF_MAP)) { | |
1148 | if (likely(pfn_valid(pfn))) | |
7be98234 | 1149 | swsusp_set_page_free(pfn_to_page(pfn)); |
940864dd RW |
1150 | else |
1151 | return -EFAULT; | |
1152 | } | |
1153 | } while (pfn != BM_END_OF_MAP); | |
f577eb30 | 1154 | |
940864dd | 1155 | allocated_unsafe_pages = 0; |
968808b8 | 1156 | |
f577eb30 RW |
1157 | return 0; |
1158 | } | |
1159 | ||
940864dd RW |
1160 | static void |
1161 | duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src) | |
f577eb30 | 1162 | { |
940864dd RW |
1163 | unsigned long pfn; |
1164 | ||
1165 | memory_bm_position_reset(src); | |
1166 | pfn = memory_bm_next_pfn(src); | |
1167 | while (pfn != BM_END_OF_MAP) { | |
1168 | memory_bm_set_bit(dst, pfn); | |
1169 | pfn = memory_bm_next_pfn(src); | |
f577eb30 RW |
1170 | } |
1171 | } | |
1172 | ||
940864dd | 1173 | static inline int check_header(struct swsusp_info *info) |
f577eb30 RW |
1174 | { |
1175 | char *reason = NULL; | |
1176 | ||
1177 | if (info->version_code != LINUX_VERSION_CODE) | |
1178 | reason = "kernel version"; | |
1179 | if (info->num_physpages != num_physpages) | |
1180 | reason = "memory size"; | |
96b644bd | 1181 | if (strcmp(info->uts.sysname,init_utsname()->sysname)) |
f577eb30 | 1182 | reason = "system type"; |
96b644bd | 1183 | if (strcmp(info->uts.release,init_utsname()->release)) |
f577eb30 | 1184 | reason = "kernel release"; |
96b644bd | 1185 | if (strcmp(info->uts.version,init_utsname()->version)) |
f577eb30 | 1186 | reason = "version"; |
96b644bd | 1187 | if (strcmp(info->uts.machine,init_utsname()->machine)) |
f577eb30 RW |
1188 | reason = "machine"; |
1189 | if (reason) { | |
1190 | printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason); | |
1191 | return -EPERM; | |
1192 | } | |
1193 | return 0; | |
1194 | } | |
1195 | ||
1196 | /** | |
1197 | * load header - check the image header and copy data from it | |
1198 | */ | |
1199 | ||
940864dd RW |
1200 | static int |
1201 | load_header(struct swsusp_info *info) | |
f577eb30 RW |
1202 | { |
1203 | int error; | |
f577eb30 | 1204 | |
940864dd | 1205 | restore_pblist = NULL; |
f577eb30 RW |
1206 | error = check_header(info); |
1207 | if (!error) { | |
f577eb30 RW |
1208 | nr_copy_pages = info->image_pages; |
1209 | nr_meta_pages = info->pages - info->image_pages - 1; | |
1210 | } | |
1211 | return error; | |
1212 | } | |
1213 | ||
1214 | /** | |
940864dd RW |
1215 | * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set |
1216 | * the corresponding bit in the memory bitmap @bm | |
f577eb30 RW |
1217 | */ |
1218 | ||
940864dd RW |
1219 | static inline void |
1220 | unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) | |
f577eb30 RW |
1221 | { |
1222 | int j; | |
1223 | ||
940864dd RW |
1224 | for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { |
1225 | if (unlikely(buf[j] == BM_END_OF_MAP)) | |
1226 | break; | |
1227 | ||
1228 | memory_bm_set_bit(bm, buf[j]); | |
f577eb30 | 1229 | } |
f577eb30 RW |
1230 | } |
1231 | ||
8357376d RW |
1232 | /* List of "safe" pages that may be used to store data loaded from the suspend |
1233 | * image | |
1234 | */ | |
1235 | static struct linked_page *safe_pages_list; | |
1236 | ||
1237 | #ifdef CONFIG_HIGHMEM | |
1238 | /* struct highmem_pbe is used for creating the list of highmem pages that | |
1239 | * should be restored atomically during the resume from disk, because the page | |
1240 | * frames they have occupied before the suspend are in use. | |
1241 | */ | |
1242 | struct highmem_pbe { | |
1243 | struct page *copy_page; /* data is here now */ | |
1244 | struct page *orig_page; /* data was here before the suspend */ | |
1245 | struct highmem_pbe *next; | |
1246 | }; | |
1247 | ||
1248 | /* List of highmem PBEs needed for restoring the highmem pages that were | |
1249 | * allocated before the suspend and included in the suspend image, but have | |
1250 | * also been allocated by the "resume" kernel, so their contents cannot be | |
1251 | * written directly to their "original" page frames. | |
1252 | */ | |
1253 | static struct highmem_pbe *highmem_pblist; | |
1254 | ||
1255 | /** | |
1256 | * count_highmem_image_pages - compute the number of highmem pages in the | |
1257 | * suspend image. The bits in the memory bitmap @bm that correspond to the | |
1258 | * image pages are assumed to be set. | |
1259 | */ | |
1260 | ||
1261 | static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) | |
1262 | { | |
1263 | unsigned long pfn; | |
1264 | unsigned int cnt = 0; | |
1265 | ||
1266 | memory_bm_position_reset(bm); | |
1267 | pfn = memory_bm_next_pfn(bm); | |
1268 | while (pfn != BM_END_OF_MAP) { | |
1269 | if (PageHighMem(pfn_to_page(pfn))) | |
1270 | cnt++; | |
1271 | ||
1272 | pfn = memory_bm_next_pfn(bm); | |
1273 | } | |
1274 | return cnt; | |
1275 | } | |
1276 | ||
1277 | /** | |
1278 | * prepare_highmem_image - try to allocate as many highmem pages as | |
1279 | * there are highmem image pages (@nr_highmem_p points to the variable | |
1280 | * containing the number of highmem image pages). The pages that are | |
1281 | * "safe" (ie. will not be overwritten when the suspend image is | |
1282 | * restored) have the corresponding bits set in @bm (it must be | |
1283 | * unitialized). | |
1284 | * | |
1285 | * NOTE: This function should not be called if there are no highmem | |
1286 | * image pages. | |
1287 | */ | |
1288 | ||
1289 | static unsigned int safe_highmem_pages; | |
1290 | ||
1291 | static struct memory_bitmap *safe_highmem_bm; | |
1292 | ||
1293 | static int | |
1294 | prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) | |
1295 | { | |
1296 | unsigned int to_alloc; | |
1297 | ||
1298 | if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE)) | |
1299 | return -ENOMEM; | |
1300 | ||
1301 | if (get_highmem_buffer(PG_SAFE)) | |
1302 | return -ENOMEM; | |
1303 | ||
1304 | to_alloc = count_free_highmem_pages(); | |
1305 | if (to_alloc > *nr_highmem_p) | |
1306 | to_alloc = *nr_highmem_p; | |
1307 | else | |
1308 | *nr_highmem_p = to_alloc; | |
1309 | ||
1310 | safe_highmem_pages = 0; | |
1311 | while (to_alloc-- > 0) { | |
1312 | struct page *page; | |
1313 | ||
1314 | page = alloc_page(__GFP_HIGHMEM); | |
7be98234 | 1315 | if (!swsusp_page_is_free(page)) { |
8357376d RW |
1316 | /* The page is "safe", set its bit the bitmap */ |
1317 | memory_bm_set_bit(bm, page_to_pfn(page)); | |
1318 | safe_highmem_pages++; | |
1319 | } | |
1320 | /* Mark the page as allocated */ | |
7be98234 RW |
1321 | swsusp_set_page_forbidden(page); |
1322 | swsusp_set_page_free(page); | |
8357376d RW |
1323 | } |
1324 | memory_bm_position_reset(bm); | |
1325 | safe_highmem_bm = bm; | |
1326 | return 0; | |
1327 | } | |
1328 | ||
1329 | /** | |
1330 | * get_highmem_page_buffer - for given highmem image page find the buffer | |
1331 | * that suspend_write_next() should set for its caller to write to. | |
1332 | * | |
1333 | * If the page is to be saved to its "original" page frame or a copy of | |
1334 | * the page is to be made in the highmem, @buffer is returned. Otherwise, | |
1335 | * the copy of the page is to be made in normal memory, so the address of | |
1336 | * the copy is returned. | |
1337 | * | |
1338 | * If @buffer is returned, the caller of suspend_write_next() will write | |
1339 | * the page's contents to @buffer, so they will have to be copied to the | |
1340 | * right location on the next call to suspend_write_next() and it is done | |
1341 | * with the help of copy_last_highmem_page(). For this purpose, if | |
1342 | * @buffer is returned, @last_highmem page is set to the page to which | |
1343 | * the data will have to be copied from @buffer. | |
1344 | */ | |
1345 | ||
1346 | static struct page *last_highmem_page; | |
1347 | ||
1348 | static void * | |
1349 | get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) | |
1350 | { | |
1351 | struct highmem_pbe *pbe; | |
1352 | void *kaddr; | |
1353 | ||
7be98234 | 1354 | if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) { |
8357376d RW |
1355 | /* We have allocated the "original" page frame and we can |
1356 | * use it directly to store the loaded page. | |
1357 | */ | |
1358 | last_highmem_page = page; | |
1359 | return buffer; | |
1360 | } | |
1361 | /* The "original" page frame has not been allocated and we have to | |
1362 | * use a "safe" page frame to store the loaded page. | |
1363 | */ | |
1364 | pbe = chain_alloc(ca, sizeof(struct highmem_pbe)); | |
1365 | if (!pbe) { | |
1366 | swsusp_free(); | |
1367 | return NULL; | |
1368 | } | |
1369 | pbe->orig_page = page; | |
1370 | if (safe_highmem_pages > 0) { | |
1371 | struct page *tmp; | |
1372 | ||
1373 | /* Copy of the page will be stored in high memory */ | |
1374 | kaddr = buffer; | |
1375 | tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm)); | |
1376 | safe_highmem_pages--; | |
1377 | last_highmem_page = tmp; | |
1378 | pbe->copy_page = tmp; | |
1379 | } else { | |
1380 | /* Copy of the page will be stored in normal memory */ | |
1381 | kaddr = safe_pages_list; | |
1382 | safe_pages_list = safe_pages_list->next; | |
1383 | pbe->copy_page = virt_to_page(kaddr); | |
1384 | } | |
1385 | pbe->next = highmem_pblist; | |
1386 | highmem_pblist = pbe; | |
1387 | return kaddr; | |
1388 | } | |
1389 | ||
1390 | /** | |
1391 | * copy_last_highmem_page - copy the contents of a highmem image from | |
1392 | * @buffer, where the caller of snapshot_write_next() has place them, | |
1393 | * to the right location represented by @last_highmem_page . | |
1394 | */ | |
1395 | ||
1396 | static void copy_last_highmem_page(void) | |
1397 | { | |
1398 | if (last_highmem_page) { | |
1399 | void *dst; | |
1400 | ||
1401 | dst = kmap_atomic(last_highmem_page, KM_USER0); | |
1402 | memcpy(dst, buffer, PAGE_SIZE); | |
1403 | kunmap_atomic(dst, KM_USER0); | |
1404 | last_highmem_page = NULL; | |
1405 | } | |
1406 | } | |
1407 | ||
1408 | static inline int last_highmem_page_copied(void) | |
1409 | { | |
1410 | return !last_highmem_page; | |
1411 | } | |
1412 | ||
1413 | static inline void free_highmem_data(void) | |
1414 | { | |
1415 | if (safe_highmem_bm) | |
1416 | memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR); | |
1417 | ||
1418 | if (buffer) | |
1419 | free_image_page(buffer, PG_UNSAFE_CLEAR); | |
1420 | } | |
1421 | #else | |
1422 | static inline int get_safe_write_buffer(void) { return 0; } | |
1423 | ||
1424 | static unsigned int | |
1425 | count_highmem_image_pages(struct memory_bitmap *bm) { return 0; } | |
1426 | ||
1427 | static inline int | |
1428 | prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) | |
1429 | { | |
1430 | return 0; | |
1431 | } | |
1432 | ||
1433 | static inline void * | |
1434 | get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) | |
1435 | { | |
1436 | return NULL; | |
1437 | } | |
1438 | ||
1439 | static inline void copy_last_highmem_page(void) {} | |
1440 | static inline int last_highmem_page_copied(void) { return 1; } | |
1441 | static inline void free_highmem_data(void) {} | |
1442 | #endif /* CONFIG_HIGHMEM */ | |
1443 | ||
f577eb30 | 1444 | /** |
940864dd RW |
1445 | * prepare_image - use the memory bitmap @bm to mark the pages that will |
1446 | * be overwritten in the process of restoring the system memory state | |
1447 | * from the suspend image ("unsafe" pages) and allocate memory for the | |
1448 | * image. | |
968808b8 | 1449 | * |
940864dd RW |
1450 | * The idea is to allocate a new memory bitmap first and then allocate |
1451 | * as many pages as needed for the image data, but not to assign these | |
1452 | * pages to specific tasks initially. Instead, we just mark them as | |
8357376d RW |
1453 | * allocated and create a lists of "safe" pages that will be used |
1454 | * later. On systems with high memory a list of "safe" highmem pages is | |
1455 | * also created. | |
f577eb30 RW |
1456 | */ |
1457 | ||
940864dd RW |
1458 | #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) |
1459 | ||
940864dd RW |
1460 | static int |
1461 | prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) | |
f577eb30 | 1462 | { |
8357376d | 1463 | unsigned int nr_pages, nr_highmem; |
940864dd RW |
1464 | struct linked_page *sp_list, *lp; |
1465 | int error; | |
f577eb30 | 1466 | |
8357376d RW |
1467 | /* If there is no highmem, the buffer will not be necessary */ |
1468 | free_image_page(buffer, PG_UNSAFE_CLEAR); | |
1469 | buffer = NULL; | |
1470 | ||
1471 | nr_highmem = count_highmem_image_pages(bm); | |
940864dd RW |
1472 | error = mark_unsafe_pages(bm); |
1473 | if (error) | |
1474 | goto Free; | |
1475 | ||
1476 | error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE); | |
1477 | if (error) | |
1478 | goto Free; | |
1479 | ||
1480 | duplicate_memory_bitmap(new_bm, bm); | |
1481 | memory_bm_free(bm, PG_UNSAFE_KEEP); | |
8357376d RW |
1482 | if (nr_highmem > 0) { |
1483 | error = prepare_highmem_image(bm, &nr_highmem); | |
1484 | if (error) | |
1485 | goto Free; | |
1486 | } | |
940864dd RW |
1487 | /* Reserve some safe pages for potential later use. |
1488 | * | |
1489 | * NOTE: This way we make sure there will be enough safe pages for the | |
1490 | * chain_alloc() in get_buffer(). It is a bit wasteful, but | |
1491 | * nr_copy_pages cannot be greater than 50% of the memory anyway. | |
1492 | */ | |
1493 | sp_list = NULL; | |
1494 | /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */ | |
8357376d | 1495 | nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; |
940864dd RW |
1496 | nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE); |
1497 | while (nr_pages > 0) { | |
8357376d | 1498 | lp = get_image_page(GFP_ATOMIC, PG_SAFE); |
940864dd | 1499 | if (!lp) { |
f577eb30 | 1500 | error = -ENOMEM; |
940864dd RW |
1501 | goto Free; |
1502 | } | |
1503 | lp->next = sp_list; | |
1504 | sp_list = lp; | |
1505 | nr_pages--; | |
f577eb30 | 1506 | } |
940864dd RW |
1507 | /* Preallocate memory for the image */ |
1508 | safe_pages_list = NULL; | |
8357376d | 1509 | nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; |
940864dd RW |
1510 | while (nr_pages > 0) { |
1511 | lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC); | |
1512 | if (!lp) { | |
1513 | error = -ENOMEM; | |
1514 | goto Free; | |
1515 | } | |
7be98234 | 1516 | if (!swsusp_page_is_free(virt_to_page(lp))) { |
940864dd RW |
1517 | /* The page is "safe", add it to the list */ |
1518 | lp->next = safe_pages_list; | |
1519 | safe_pages_list = lp; | |
968808b8 | 1520 | } |
940864dd | 1521 | /* Mark the page as allocated */ |
7be98234 RW |
1522 | swsusp_set_page_forbidden(virt_to_page(lp)); |
1523 | swsusp_set_page_free(virt_to_page(lp)); | |
940864dd | 1524 | nr_pages--; |
968808b8 | 1525 | } |
940864dd RW |
1526 | /* Free the reserved safe pages so that chain_alloc() can use them */ |
1527 | while (sp_list) { | |
1528 | lp = sp_list->next; | |
1529 | free_image_page(sp_list, PG_UNSAFE_CLEAR); | |
1530 | sp_list = lp; | |
f577eb30 | 1531 | } |
940864dd RW |
1532 | return 0; |
1533 | ||
59a49335 | 1534 | Free: |
940864dd | 1535 | swsusp_free(); |
f577eb30 RW |
1536 | return error; |
1537 | } | |
1538 | ||
940864dd RW |
1539 | /** |
1540 | * get_buffer - compute the address that snapshot_write_next() should | |
1541 | * set for its caller to write to. | |
1542 | */ | |
1543 | ||
1544 | static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) | |
968808b8 | 1545 | { |
940864dd RW |
1546 | struct pbe *pbe; |
1547 | struct page *page = pfn_to_page(memory_bm_next_pfn(bm)); | |
968808b8 | 1548 | |
8357376d RW |
1549 | if (PageHighMem(page)) |
1550 | return get_highmem_page_buffer(page, ca); | |
1551 | ||
7be98234 | 1552 | if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) |
940864dd RW |
1553 | /* We have allocated the "original" page frame and we can |
1554 | * use it directly to store the loaded page. | |
968808b8 | 1555 | */ |
940864dd RW |
1556 | return page_address(page); |
1557 | ||
1558 | /* The "original" page frame has not been allocated and we have to | |
1559 | * use a "safe" page frame to store the loaded page. | |
968808b8 | 1560 | */ |
940864dd RW |
1561 | pbe = chain_alloc(ca, sizeof(struct pbe)); |
1562 | if (!pbe) { | |
1563 | swsusp_free(); | |
1564 | return NULL; | |
1565 | } | |
8357376d RW |
1566 | pbe->orig_address = page_address(page); |
1567 | pbe->address = safe_pages_list; | |
940864dd RW |
1568 | safe_pages_list = safe_pages_list->next; |
1569 | pbe->next = restore_pblist; | |
1570 | restore_pblist = pbe; | |
8357376d | 1571 | return pbe->address; |
968808b8 RW |
1572 | } |
1573 | ||
f577eb30 RW |
1574 | /** |
1575 | * snapshot_write_next - used for writing the system memory snapshot. | |
1576 | * | |
1577 | * On the first call to it @handle should point to a zeroed | |
1578 | * snapshot_handle structure. The structure gets updated and a pointer | |
1579 | * to it should be passed to this function every next time. | |
1580 | * | |
1581 | * The @count parameter should contain the number of bytes the caller | |
1582 | * wants to write to the image. It must not be zero. | |
1583 | * | |
1584 | * On success the function returns a positive number. Then, the caller | |
1585 | * is allowed to write up to the returned number of bytes to the memory | |
1586 | * location computed by the data_of() macro. The number returned | |
1587 | * may be smaller than @count, but this only happens if the write would | |
1588 | * cross a page boundary otherwise. | |
1589 | * | |
1590 | * The function returns 0 to indicate the "end of file" condition, | |
1591 | * and a negative number is returned on error. In such cases the | |
1592 | * structure pointed to by @handle is not updated and should not be used | |
1593 | * any more. | |
1594 | */ | |
1595 | ||
1596 | int snapshot_write_next(struct snapshot_handle *handle, size_t count) | |
1597 | { | |
940864dd | 1598 | static struct chain_allocator ca; |
f577eb30 RW |
1599 | int error = 0; |
1600 | ||
940864dd | 1601 | /* Check if we have already loaded the entire image */ |
fb13a28b | 1602 | if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 | 1603 | return 0; |
940864dd | 1604 | |
8357376d RW |
1605 | if (handle->offset == 0) { |
1606 | if (!buffer) | |
1607 | /* This makes the buffer be freed by swsusp_free() */ | |
1608 | buffer = get_image_page(GFP_ATOMIC, PG_ANY); | |
1609 | ||
f577eb30 RW |
1610 | if (!buffer) |
1611 | return -ENOMEM; | |
8357376d | 1612 | |
f577eb30 | 1613 | handle->buffer = buffer; |
8357376d | 1614 | } |
546e0d27 | 1615 | handle->sync_read = 1; |
fb13a28b | 1616 | if (handle->prev < handle->cur) { |
940864dd RW |
1617 | if (handle->prev == 0) { |
1618 | error = load_header(buffer); | |
1619 | if (error) | |
1620 | return error; | |
1621 | ||
1622 | error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); | |
f577eb30 RW |
1623 | if (error) |
1624 | return error; | |
940864dd | 1625 | |
f577eb30 | 1626 | } else if (handle->prev <= nr_meta_pages) { |
940864dd RW |
1627 | unpack_orig_pfns(buffer, ©_bm); |
1628 | if (handle->prev == nr_meta_pages) { | |
1629 | error = prepare_image(&orig_bm, ©_bm); | |
f577eb30 RW |
1630 | if (error) |
1631 | return error; | |
940864dd RW |
1632 | |
1633 | chain_init(&ca, GFP_ATOMIC, PG_SAFE); | |
1634 | memory_bm_position_reset(&orig_bm); | |
1635 | restore_pblist = NULL; | |
1636 | handle->buffer = get_buffer(&orig_bm, &ca); | |
546e0d27 | 1637 | handle->sync_read = 0; |
940864dd RW |
1638 | if (!handle->buffer) |
1639 | return -ENOMEM; | |
f577eb30 RW |
1640 | } |
1641 | } else { | |
8357376d | 1642 | copy_last_highmem_page(); |
940864dd | 1643 | handle->buffer = get_buffer(&orig_bm, &ca); |
8357376d RW |
1644 | if (handle->buffer != buffer) |
1645 | handle->sync_read = 0; | |
f577eb30 | 1646 | } |
fb13a28b | 1647 | handle->prev = handle->cur; |
f577eb30 | 1648 | } |
fb13a28b RW |
1649 | handle->buf_offset = handle->cur_offset; |
1650 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
1651 | count = PAGE_SIZE - handle->cur_offset; | |
1652 | handle->cur_offset = 0; | |
1653 | handle->cur++; | |
f577eb30 | 1654 | } else { |
fb13a28b | 1655 | handle->cur_offset += count; |
f577eb30 RW |
1656 | } |
1657 | handle->offset += count; | |
1658 | return count; | |
1659 | } | |
1660 | ||
8357376d RW |
1661 | /** |
1662 | * snapshot_write_finalize - must be called after the last call to | |
1663 | * snapshot_write_next() in case the last page in the image happens | |
1664 | * to be a highmem page and its contents should be stored in the | |
1665 | * highmem. Additionally, it releases the memory that will not be | |
1666 | * used any more. | |
1667 | */ | |
1668 | ||
1669 | void snapshot_write_finalize(struct snapshot_handle *handle) | |
1670 | { | |
1671 | copy_last_highmem_page(); | |
1672 | /* Free only if we have loaded the image entirely */ | |
1673 | if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) { | |
1674 | memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR); | |
1675 | free_highmem_data(); | |
1676 | } | |
1677 | } | |
1678 | ||
f577eb30 RW |
1679 | int snapshot_image_loaded(struct snapshot_handle *handle) |
1680 | { | |
8357376d | 1681 | return !(!nr_copy_pages || !last_highmem_page_copied() || |
940864dd RW |
1682 | handle->cur <= nr_meta_pages + nr_copy_pages); |
1683 | } | |
1684 | ||
8357376d RW |
1685 | #ifdef CONFIG_HIGHMEM |
1686 | /* Assumes that @buf is ready and points to a "safe" page */ | |
1687 | static inline void | |
1688 | swap_two_pages_data(struct page *p1, struct page *p2, void *buf) | |
940864dd | 1689 | { |
8357376d RW |
1690 | void *kaddr1, *kaddr2; |
1691 | ||
1692 | kaddr1 = kmap_atomic(p1, KM_USER0); | |
1693 | kaddr2 = kmap_atomic(p2, KM_USER1); | |
1694 | memcpy(buf, kaddr1, PAGE_SIZE); | |
1695 | memcpy(kaddr1, kaddr2, PAGE_SIZE); | |
1696 | memcpy(kaddr2, buf, PAGE_SIZE); | |
1697 | kunmap_atomic(kaddr1, KM_USER0); | |
1698 | kunmap_atomic(kaddr2, KM_USER1); | |
1699 | } | |
1700 | ||
1701 | /** | |
1702 | * restore_highmem - for each highmem page that was allocated before | |
1703 | * the suspend and included in the suspend image, and also has been | |
1704 | * allocated by the "resume" kernel swap its current (ie. "before | |
1705 | * resume") contents with the previous (ie. "before suspend") one. | |
1706 | * | |
1707 | * If the resume eventually fails, we can call this function once | |
1708 | * again and restore the "before resume" highmem state. | |
1709 | */ | |
1710 | ||
1711 | int restore_highmem(void) | |
1712 | { | |
1713 | struct highmem_pbe *pbe = highmem_pblist; | |
1714 | void *buf; | |
1715 | ||
1716 | if (!pbe) | |
1717 | return 0; | |
1718 | ||
1719 | buf = get_image_page(GFP_ATOMIC, PG_SAFE); | |
1720 | if (!buf) | |
1721 | return -ENOMEM; | |
1722 | ||
1723 | while (pbe) { | |
1724 | swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf); | |
1725 | pbe = pbe->next; | |
1726 | } | |
1727 | free_image_page(buf, PG_UNSAFE_CLEAR); | |
1728 | return 0; | |
f577eb30 | 1729 | } |
8357376d | 1730 | #endif /* CONFIG_HIGHMEM */ |