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25761b6e | 1 | /* |
96bc7aec | 2 | * linux/kernel/power/snapshot.c |
25761b6e | 3 | * |
96bc7aec | 4 | * This file provide system snapshot/restore functionality. |
25761b6e RW |
5 | * |
6 | * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz> | |
7 | * | |
8 | * This file is released under the GPLv2, and is based on swsusp.c. | |
9 | * | |
10 | */ | |
11 | ||
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/suspend.h> | |
16 | #include <linux/smp_lock.h> | |
25761b6e | 17 | #include <linux/delay.h> |
25761b6e | 18 | #include <linux/bitops.h> |
25761b6e | 19 | #include <linux/spinlock.h> |
25761b6e | 20 | #include <linux/kernel.h> |
25761b6e RW |
21 | #include <linux/pm.h> |
22 | #include <linux/device.h> | |
25761b6e RW |
23 | #include <linux/bootmem.h> |
24 | #include <linux/syscalls.h> | |
25 | #include <linux/console.h> | |
26 | #include <linux/highmem.h> | |
25761b6e RW |
27 | |
28 | #include <asm/uaccess.h> | |
29 | #include <asm/mmu_context.h> | |
30 | #include <asm/pgtable.h> | |
31 | #include <asm/tlbflush.h> | |
32 | #include <asm/io.h> | |
33 | ||
25761b6e RW |
34 | #include "power.h" |
35 | ||
7088a5c0 RW |
36 | struct pbe *pagedir_nosave; |
37 | unsigned int nr_copy_pages; | |
38 | ||
25761b6e | 39 | #ifdef CONFIG_HIGHMEM |
72a97e08 RW |
40 | unsigned int count_highmem_pages(void) |
41 | { | |
42 | struct zone *zone; | |
43 | unsigned long zone_pfn; | |
44 | unsigned int n = 0; | |
45 | ||
46 | for_each_zone (zone) | |
47 | if (is_highmem(zone)) { | |
48 | mark_free_pages(zone); | |
49 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; zone_pfn++) { | |
50 | struct page *page; | |
51 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; | |
52 | if (!pfn_valid(pfn)) | |
53 | continue; | |
54 | page = pfn_to_page(pfn); | |
55 | if (PageReserved(page)) | |
56 | continue; | |
57 | if (PageNosaveFree(page)) | |
58 | continue; | |
59 | n++; | |
60 | } | |
61 | } | |
62 | return n; | |
63 | } | |
64 | ||
25761b6e RW |
65 | struct highmem_page { |
66 | char *data; | |
67 | struct page *page; | |
68 | struct highmem_page *next; | |
69 | }; | |
70 | ||
71 | static struct highmem_page *highmem_copy; | |
72 | ||
73 | static int save_highmem_zone(struct zone *zone) | |
74 | { | |
75 | unsigned long zone_pfn; | |
76 | mark_free_pages(zone); | |
77 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { | |
78 | struct page *page; | |
79 | struct highmem_page *save; | |
80 | void *kaddr; | |
81 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; | |
82 | ||
83 | if (!(pfn%1000)) | |
84 | printk("."); | |
85 | if (!pfn_valid(pfn)) | |
86 | continue; | |
87 | page = pfn_to_page(pfn); | |
88 | /* | |
89 | * This condition results from rvmalloc() sans vmalloc_32() | |
90 | * and architectural memory reservations. This should be | |
91 | * corrected eventually when the cases giving rise to this | |
92 | * are better understood. | |
93 | */ | |
94 | if (PageReserved(page)) { | |
95 | printk("highmem reserved page?!\n"); | |
96 | continue; | |
97 | } | |
98 | BUG_ON(PageNosave(page)); | |
99 | if (PageNosaveFree(page)) | |
100 | continue; | |
101 | save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC); | |
102 | if (!save) | |
103 | return -ENOMEM; | |
104 | save->next = highmem_copy; | |
105 | save->page = page; | |
106 | save->data = (void *) get_zeroed_page(GFP_ATOMIC); | |
107 | if (!save->data) { | |
108 | kfree(save); | |
109 | return -ENOMEM; | |
110 | } | |
111 | kaddr = kmap_atomic(page, KM_USER0); | |
112 | memcpy(save->data, kaddr, PAGE_SIZE); | |
113 | kunmap_atomic(kaddr, KM_USER0); | |
114 | highmem_copy = save; | |
115 | } | |
116 | return 0; | |
117 | } | |
25761b6e | 118 | |
0fbeb5a4 | 119 | int save_highmem(void) |
25761b6e | 120 | { |
25761b6e RW |
121 | struct zone *zone; |
122 | int res = 0; | |
123 | ||
124 | pr_debug("swsusp: Saving Highmem\n"); | |
125 | for_each_zone (zone) { | |
126 | if (is_highmem(zone)) | |
127 | res = save_highmem_zone(zone); | |
128 | if (res) | |
129 | return res; | |
130 | } | |
25761b6e RW |
131 | return 0; |
132 | } | |
133 | ||
134 | int restore_highmem(void) | |
135 | { | |
25761b6e RW |
136 | printk("swsusp: Restoring Highmem\n"); |
137 | while (highmem_copy) { | |
138 | struct highmem_page *save = highmem_copy; | |
139 | void *kaddr; | |
140 | highmem_copy = save->next; | |
141 | ||
142 | kaddr = kmap_atomic(save->page, KM_USER0); | |
143 | memcpy(kaddr, save->data, PAGE_SIZE); | |
144 | kunmap_atomic(kaddr, KM_USER0); | |
145 | free_page((long) save->data); | |
146 | kfree(save); | |
147 | } | |
25761b6e RW |
148 | return 0; |
149 | } | |
0fbeb5a4 | 150 | #endif |
25761b6e RW |
151 | |
152 | static int pfn_is_nosave(unsigned long pfn) | |
153 | { | |
154 | unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; | |
155 | unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; | |
156 | return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); | |
157 | } | |
158 | ||
159 | /** | |
160 | * saveable - Determine whether a page should be cloned or not. | |
161 | * @pfn: The page | |
162 | * | |
163 | * We save a page if it's Reserved, and not in the range of pages | |
164 | * statically defined as 'unsaveable', or if it isn't reserved, and | |
165 | * isn't part of a free chunk of pages. | |
166 | */ | |
167 | ||
de491861 | 168 | static int saveable(struct zone *zone, unsigned long *zone_pfn) |
25761b6e RW |
169 | { |
170 | unsigned long pfn = *zone_pfn + zone->zone_start_pfn; | |
de491861 | 171 | struct page *page; |
25761b6e RW |
172 | |
173 | if (!pfn_valid(pfn)) | |
174 | return 0; | |
175 | ||
176 | page = pfn_to_page(pfn); | |
177 | BUG_ON(PageReserved(page) && PageNosave(page)); | |
178 | if (PageNosave(page)) | |
179 | return 0; | |
72a97e08 | 180 | if (PageReserved(page) && pfn_is_nosave(pfn)) |
25761b6e | 181 | return 0; |
25761b6e RW |
182 | if (PageNosaveFree(page)) |
183 | return 0; | |
184 | ||
185 | return 1; | |
186 | } | |
187 | ||
72a97e08 | 188 | unsigned int count_data_pages(void) |
25761b6e RW |
189 | { |
190 | struct zone *zone; | |
191 | unsigned long zone_pfn; | |
dc19d507 | 192 | unsigned int n = 0; |
25761b6e | 193 | |
25761b6e RW |
194 | for_each_zone (zone) { |
195 | if (is_highmem(zone)) | |
196 | continue; | |
197 | mark_free_pages(zone); | |
198 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) | |
a0f49651 | 199 | n += saveable(zone, &zone_pfn); |
25761b6e | 200 | } |
a0f49651 | 201 | return n; |
25761b6e RW |
202 | } |
203 | ||
a0f49651 | 204 | static void copy_data_pages(struct pbe *pblist) |
25761b6e RW |
205 | { |
206 | struct zone *zone; | |
207 | unsigned long zone_pfn; | |
a0f49651 | 208 | struct pbe *pbe, *p; |
25761b6e | 209 | |
a0f49651 | 210 | pbe = pblist; |
25761b6e RW |
211 | for_each_zone (zone) { |
212 | if (is_highmem(zone)) | |
213 | continue; | |
214 | mark_free_pages(zone); | |
215 | /* This is necessary for swsusp_free() */ | |
a0f49651 | 216 | for_each_pb_page (p, pblist) |
25761b6e | 217 | SetPageNosaveFree(virt_to_page(p)); |
a0f49651 | 218 | for_each_pbe (p, pblist) |
25761b6e RW |
219 | SetPageNosaveFree(virt_to_page(p->address)); |
220 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { | |
221 | if (saveable(zone, &zone_pfn)) { | |
de491861 | 222 | struct page *page; |
25761b6e RW |
223 | page = pfn_to_page(zone_pfn + zone->zone_start_pfn); |
224 | BUG_ON(!pbe); | |
225 | pbe->orig_address = (unsigned long)page_address(page); | |
226 | /* copy_page is not usable for copying task structs. */ | |
227 | memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE); | |
228 | pbe = pbe->next; | |
229 | } | |
230 | } | |
231 | } | |
232 | BUG_ON(pbe); | |
233 | } | |
234 | ||
235 | ||
236 | /** | |
237 | * free_pagedir - free pages allocated with alloc_pagedir() | |
238 | */ | |
239 | ||
ed14b527 | 240 | void free_pagedir(struct pbe *pblist) |
25761b6e RW |
241 | { |
242 | struct pbe *pbe; | |
243 | ||
244 | while (pblist) { | |
245 | pbe = (pblist + PB_PAGE_SKIP)->next; | |
246 | ClearPageNosave(virt_to_page(pblist)); | |
247 | ClearPageNosaveFree(virt_to_page(pblist)); | |
248 | free_page((unsigned long)pblist); | |
249 | pblist = pbe; | |
250 | } | |
251 | } | |
252 | ||
253 | /** | |
254 | * fill_pb_page - Create a list of PBEs on a given memory page | |
255 | */ | |
256 | ||
257 | static inline void fill_pb_page(struct pbe *pbpage) | |
258 | { | |
259 | struct pbe *p; | |
260 | ||
261 | p = pbpage; | |
262 | pbpage += PB_PAGE_SKIP; | |
263 | do | |
264 | p->next = p + 1; | |
265 | while (++p < pbpage); | |
266 | } | |
267 | ||
268 | /** | |
269 | * create_pbe_list - Create a list of PBEs on top of a given chain | |
270 | * of memory pages allocated with alloc_pagedir() | |
271 | */ | |
272 | ||
7088a5c0 | 273 | static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) |
25761b6e RW |
274 | { |
275 | struct pbe *pbpage, *p; | |
dc19d507 | 276 | unsigned int num = PBES_PER_PAGE; |
25761b6e RW |
277 | |
278 | for_each_pb_page (pbpage, pblist) { | |
279 | if (num >= nr_pages) | |
280 | break; | |
281 | ||
282 | fill_pb_page(pbpage); | |
283 | num += PBES_PER_PAGE; | |
284 | } | |
285 | if (pbpage) { | |
286 | for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++) | |
287 | p->next = p + 1; | |
288 | p->next = NULL; | |
289 | } | |
25761b6e RW |
290 | } |
291 | ||
72a97e08 RW |
292 | /** |
293 | * On resume it is necessary to trace and eventually free the unsafe | |
294 | * pages that have been allocated, because they are needed for I/O | |
295 | * (on x86-64 we likely will "eat" these pages once again while | |
296 | * creating the temporary page translation tables) | |
297 | */ | |
298 | ||
299 | struct eaten_page { | |
300 | struct eaten_page *next; | |
301 | char padding[PAGE_SIZE - sizeof(void *)]; | |
302 | }; | |
303 | ||
304 | static struct eaten_page *eaten_pages = NULL; | |
305 | ||
306 | void release_eaten_pages(void) | |
307 | { | |
308 | struct eaten_page *p, *q; | |
309 | ||
310 | p = eaten_pages; | |
311 | while (p) { | |
312 | q = p->next; | |
313 | /* We don't want swsusp_free() to free this page again */ | |
314 | ClearPageNosave(virt_to_page(p)); | |
315 | free_page((unsigned long)p); | |
316 | p = q; | |
317 | } | |
318 | eaten_pages = NULL; | |
319 | } | |
320 | ||
054bd4c1 RW |
321 | /** |
322 | * @safe_needed - on resume, for storing the PBE list and the image, | |
323 | * we can only use memory pages that do not conflict with the pages | |
324 | * which had been used before suspend. | |
325 | * | |
326 | * The unsafe pages are marked with the PG_nosave_free flag | |
327 | * | |
328 | * Allocated but unusable (ie eaten) memory pages should be marked | |
329 | * so that swsusp_free() can release them | |
330 | */ | |
331 | ||
332 | static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed) | |
25761b6e | 333 | { |
054bd4c1 RW |
334 | void *res; |
335 | ||
336 | if (safe_needed) | |
337 | do { | |
338 | res = (void *)get_zeroed_page(gfp_mask); | |
72a97e08 | 339 | if (res && PageNosaveFree(virt_to_page(res))) { |
054bd4c1 RW |
340 | /* This is for swsusp_free() */ |
341 | SetPageNosave(virt_to_page(res)); | |
72a97e08 RW |
342 | ((struct eaten_page *)res)->next = eaten_pages; |
343 | eaten_pages = res; | |
344 | } | |
054bd4c1 RW |
345 | } while (res && PageNosaveFree(virt_to_page(res))); |
346 | else | |
347 | res = (void *)get_zeroed_page(gfp_mask); | |
25761b6e RW |
348 | if (res) { |
349 | SetPageNosave(virt_to_page(res)); | |
350 | SetPageNosaveFree(virt_to_page(res)); | |
351 | } | |
352 | return res; | |
353 | } | |
354 | ||
054bd4c1 RW |
355 | unsigned long get_safe_page(gfp_t gfp_mask) |
356 | { | |
357 | return (unsigned long)alloc_image_page(gfp_mask, 1); | |
358 | } | |
359 | ||
25761b6e RW |
360 | /** |
361 | * alloc_pagedir - Allocate the page directory. | |
362 | * | |
363 | * First, determine exactly how many pages we need and | |
364 | * allocate them. | |
365 | * | |
366 | * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE | |
367 | * struct pbe elements (pbes) and the last element in the page points | |
368 | * to the next page. | |
369 | * | |
370 | * On each page we set up a list of struct_pbe elements. | |
371 | */ | |
372 | ||
054bd4c1 | 373 | struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed) |
25761b6e | 374 | { |
dc19d507 | 375 | unsigned int num; |
25761b6e RW |
376 | struct pbe *pblist, *pbe; |
377 | ||
378 | if (!nr_pages) | |
379 | return NULL; | |
380 | ||
381 | pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages); | |
054bd4c1 | 382 | pblist = alloc_image_page(gfp_mask, safe_needed); |
25761b6e RW |
383 | /* FIXME: rewrite this ugly loop */ |
384 | for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages; | |
385 | pbe = pbe->next, num += PBES_PER_PAGE) { | |
386 | pbe += PB_PAGE_SKIP; | |
054bd4c1 | 387 | pbe->next = alloc_image_page(gfp_mask, safe_needed); |
25761b6e RW |
388 | } |
389 | if (!pbe) { /* get_zeroed_page() failed */ | |
390 | free_pagedir(pblist); | |
391 | pblist = NULL; | |
7088a5c0 RW |
392 | } else |
393 | create_pbe_list(pblist, nr_pages); | |
25761b6e RW |
394 | return pblist; |
395 | } | |
396 | ||
397 | /** | |
398 | * Free pages we allocated for suspend. Suspend pages are alocated | |
399 | * before atomic copy, so we need to free them after resume. | |
400 | */ | |
401 | ||
402 | void swsusp_free(void) | |
403 | { | |
404 | struct zone *zone; | |
405 | unsigned long zone_pfn; | |
406 | ||
407 | for_each_zone(zone) { | |
408 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) | |
409 | if (pfn_valid(zone_pfn + zone->zone_start_pfn)) { | |
dc19d507 | 410 | struct page *page; |
25761b6e RW |
411 | page = pfn_to_page(zone_pfn + zone->zone_start_pfn); |
412 | if (PageNosave(page) && PageNosaveFree(page)) { | |
413 | ClearPageNosave(page); | |
414 | ClearPageNosaveFree(page); | |
415 | free_page((long) page_address(page)); | |
416 | } | |
417 | } | |
418 | } | |
419 | } | |
420 | ||
421 | ||
422 | /** | |
423 | * enough_free_mem - Make sure we enough free memory to snapshot. | |
424 | * | |
425 | * Returns TRUE or FALSE after checking the number of available | |
426 | * free pages. | |
427 | */ | |
428 | ||
dc19d507 | 429 | static int enough_free_mem(unsigned int nr_pages) |
25761b6e | 430 | { |
e5e2fa78 RW |
431 | struct zone *zone; |
432 | unsigned int n = 0; | |
433 | ||
434 | for_each_zone (zone) | |
435 | if (!is_highmem(zone)) | |
436 | n += zone->free_pages; | |
437 | pr_debug("swsusp: available memory: %u pages\n", n); | |
438 | return n > (nr_pages + PAGES_FOR_IO + | |
a0f49651 | 439 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); |
25761b6e RW |
440 | } |
441 | ||
054bd4c1 RW |
442 | int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) |
443 | { | |
444 | struct pbe *p; | |
445 | ||
446 | for_each_pbe (p, pblist) { | |
447 | p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); | |
448 | if (!p->address) | |
449 | return -ENOMEM; | |
450 | } | |
451 | return 0; | |
452 | } | |
25761b6e | 453 | |
dc19d507 | 454 | static struct pbe *swsusp_alloc(unsigned int nr_pages) |
25761b6e | 455 | { |
054bd4c1 | 456 | struct pbe *pblist; |
25761b6e | 457 | |
054bd4c1 | 458 | if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) { |
25761b6e | 459 | printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); |
a0f49651 | 460 | return NULL; |
25761b6e | 461 | } |
25761b6e | 462 | |
054bd4c1 RW |
463 | if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) { |
464 | printk(KERN_ERR "suspend: Allocating image pages failed.\n"); | |
465 | swsusp_free(); | |
466 | return NULL; | |
25761b6e RW |
467 | } |
468 | ||
a0f49651 | 469 | return pblist; |
25761b6e RW |
470 | } |
471 | ||
2e32a43e | 472 | asmlinkage int swsusp_save(void) |
25761b6e | 473 | { |
dc19d507 | 474 | unsigned int nr_pages; |
25761b6e RW |
475 | |
476 | pr_debug("swsusp: critical section: \n"); | |
25761b6e RW |
477 | |
478 | drain_local_pages(); | |
a0f49651 RW |
479 | nr_pages = count_data_pages(); |
480 | printk("swsusp: Need to copy %u pages\n", nr_pages); | |
25761b6e RW |
481 | |
482 | pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", | |
a0f49651 RW |
483 | nr_pages, |
484 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, | |
25761b6e RW |
485 | PAGES_FOR_IO, nr_free_pages()); |
486 | ||
a0f49651 | 487 | if (!enough_free_mem(nr_pages)) { |
25761b6e RW |
488 | printk(KERN_ERR "swsusp: Not enough free memory\n"); |
489 | return -ENOMEM; | |
490 | } | |
491 | ||
a0f49651 RW |
492 | pagedir_nosave = swsusp_alloc(nr_pages); |
493 | if (!pagedir_nosave) | |
494 | return -ENOMEM; | |
25761b6e RW |
495 | |
496 | /* During allocating of suspend pagedir, new cold pages may appear. | |
497 | * Kill them. | |
498 | */ | |
499 | drain_local_pages(); | |
a0f49651 | 500 | copy_data_pages(pagedir_nosave); |
25761b6e RW |
501 | |
502 | /* | |
503 | * End of critical section. From now on, we can write to memory, | |
504 | * but we should not touch disk. This specially means we must _not_ | |
505 | * touch swap space! Except we must write out our image of course. | |
506 | */ | |
507 | ||
a0f49651 RW |
508 | nr_copy_pages = nr_pages; |
509 | ||
510 | printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); | |
25761b6e RW |
511 | return 0; |
512 | } |