Commit | Line | Data |
---|---|---|
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 | ||
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 | ||
75534b50 RW |
37 | /* List of PBEs used for creating and restoring the suspend image */ |
38 | struct pbe *restore_pblist; | |
39 | ||
f577eb30 RW |
40 | static unsigned int nr_copy_pages; |
41 | static unsigned int nr_meta_pages; | |
6e1819d6 | 42 | static unsigned long *buffer; |
7088a5c0 | 43 | |
25761b6e | 44 | #ifdef CONFIG_HIGHMEM |
3448097f | 45 | unsigned int count_highmem_pages(void) |
72a97e08 RW |
46 | { |
47 | struct zone *zone; | |
48 | unsigned long zone_pfn; | |
49 | unsigned int n = 0; | |
50 | ||
51 | for_each_zone (zone) | |
52 | if (is_highmem(zone)) { | |
53 | mark_free_pages(zone); | |
54 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; zone_pfn++) { | |
55 | struct page *page; | |
56 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; | |
57 | if (!pfn_valid(pfn)) | |
58 | continue; | |
59 | page = pfn_to_page(pfn); | |
60 | if (PageReserved(page)) | |
61 | continue; | |
62 | if (PageNosaveFree(page)) | |
63 | continue; | |
64 | n++; | |
65 | } | |
66 | } | |
67 | return n; | |
68 | } | |
69 | ||
25761b6e RW |
70 | struct highmem_page { |
71 | char *data; | |
72 | struct page *page; | |
73 | struct highmem_page *next; | |
74 | }; | |
75 | ||
76 | static struct highmem_page *highmem_copy; | |
77 | ||
78 | static int save_highmem_zone(struct zone *zone) | |
79 | { | |
80 | unsigned long zone_pfn; | |
81 | mark_free_pages(zone); | |
82 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { | |
83 | struct page *page; | |
84 | struct highmem_page *save; | |
85 | void *kaddr; | |
86 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; | |
87 | ||
ce6ed29f | 88 | if (!(pfn%10000)) |
25761b6e RW |
89 | printk("."); |
90 | if (!pfn_valid(pfn)) | |
91 | continue; | |
92 | page = pfn_to_page(pfn); | |
93 | /* | |
94 | * This condition results from rvmalloc() sans vmalloc_32() | |
95 | * and architectural memory reservations. This should be | |
96 | * corrected eventually when the cases giving rise to this | |
97 | * are better understood. | |
98 | */ | |
c8adb494 | 99 | if (PageReserved(page)) |
25761b6e | 100 | continue; |
25761b6e RW |
101 | BUG_ON(PageNosave(page)); |
102 | if (PageNosaveFree(page)) | |
103 | continue; | |
104 | save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC); | |
105 | if (!save) | |
106 | return -ENOMEM; | |
107 | save->next = highmem_copy; | |
108 | save->page = page; | |
109 | save->data = (void *) get_zeroed_page(GFP_ATOMIC); | |
110 | if (!save->data) { | |
111 | kfree(save); | |
112 | return -ENOMEM; | |
113 | } | |
114 | kaddr = kmap_atomic(page, KM_USER0); | |
115 | memcpy(save->data, kaddr, PAGE_SIZE); | |
116 | kunmap_atomic(kaddr, KM_USER0); | |
117 | highmem_copy = save; | |
118 | } | |
119 | return 0; | |
120 | } | |
25761b6e | 121 | |
3448097f | 122 | int save_highmem(void) |
25761b6e | 123 | { |
25761b6e RW |
124 | struct zone *zone; |
125 | int res = 0; | |
126 | ||
ce6ed29f | 127 | pr_debug("swsusp: Saving Highmem"); |
e4e4d665 | 128 | drain_local_pages(); |
25761b6e RW |
129 | for_each_zone (zone) { |
130 | if (is_highmem(zone)) | |
131 | res = save_highmem_zone(zone); | |
132 | if (res) | |
133 | return res; | |
134 | } | |
ce6ed29f | 135 | printk("\n"); |
25761b6e RW |
136 | return 0; |
137 | } | |
138 | ||
3448097f | 139 | int restore_highmem(void) |
25761b6e | 140 | { |
25761b6e RW |
141 | printk("swsusp: Restoring Highmem\n"); |
142 | while (highmem_copy) { | |
143 | struct highmem_page *save = highmem_copy; | |
144 | void *kaddr; | |
145 | highmem_copy = save->next; | |
146 | ||
147 | kaddr = kmap_atomic(save->page, KM_USER0); | |
148 | memcpy(kaddr, save->data, PAGE_SIZE); | |
149 | kunmap_atomic(kaddr, KM_USER0); | |
150 | free_page((long) save->data); | |
151 | kfree(save); | |
152 | } | |
25761b6e RW |
153 | return 0; |
154 | } | |
ce4ab001 | 155 | #else |
7bff24e2 AB |
156 | static inline unsigned int count_highmem_pages(void) {return 0;} |
157 | static inline int save_highmem(void) {return 0;} | |
158 | static inline int restore_highmem(void) {return 0;} | |
0fbeb5a4 | 159 | #endif |
25761b6e | 160 | |
f6143aa6 RW |
161 | /** |
162 | * @safe_needed - on resume, for storing the PBE list and the image, | |
163 | * we can only use memory pages that do not conflict with the pages | |
164 | * used before suspend. | |
165 | * | |
166 | * The unsafe pages are marked with the PG_nosave_free flag | |
167 | * and we count them using unsafe_pages | |
168 | */ | |
169 | ||
170 | static unsigned int unsafe_pages; | |
171 | ||
172 | static void *alloc_image_page(gfp_t gfp_mask, int safe_needed) | |
173 | { | |
174 | void *res; | |
175 | ||
176 | res = (void *)get_zeroed_page(gfp_mask); | |
177 | if (safe_needed) | |
178 | while (res && PageNosaveFree(virt_to_page(res))) { | |
179 | /* The page is unsafe, mark it for swsusp_free() */ | |
180 | SetPageNosave(virt_to_page(res)); | |
181 | unsafe_pages++; | |
182 | res = (void *)get_zeroed_page(gfp_mask); | |
183 | } | |
184 | if (res) { | |
185 | SetPageNosave(virt_to_page(res)); | |
186 | SetPageNosaveFree(virt_to_page(res)); | |
187 | } | |
188 | return res; | |
189 | } | |
190 | ||
191 | unsigned long get_safe_page(gfp_t gfp_mask) | |
192 | { | |
193 | return (unsigned long)alloc_image_page(gfp_mask, 1); | |
194 | } | |
195 | ||
196 | /** | |
197 | * free_image_page - free page represented by @addr, allocated with | |
198 | * alloc_image_page (page flags set by it must be cleared) | |
199 | */ | |
200 | ||
201 | static inline void free_image_page(void *addr, int clear_nosave_free) | |
202 | { | |
203 | ClearPageNosave(virt_to_page(addr)); | |
204 | if (clear_nosave_free) | |
205 | ClearPageNosaveFree(virt_to_page(addr)); | |
206 | free_page((unsigned long)addr); | |
207 | } | |
208 | ||
209 | /** | |
210 | * pfn_is_nosave - check if given pfn is in the 'nosave' section | |
211 | */ | |
212 | ||
ae83c5ee | 213 | static inline int pfn_is_nosave(unsigned long pfn) |
25761b6e RW |
214 | { |
215 | unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; | |
216 | unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; | |
217 | return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); | |
218 | } | |
219 | ||
220 | /** | |
221 | * saveable - Determine whether a page should be cloned or not. | |
222 | * @pfn: The page | |
223 | * | |
ae83c5ee RW |
224 | * We save a page if it isn't Nosave, and is not in the range of pages |
225 | * statically defined as 'unsaveable', and it | |
226 | * isn't a part of a free chunk of pages. | |
25761b6e RW |
227 | */ |
228 | ||
ae83c5ee | 229 | static struct page *saveable_page(unsigned long pfn) |
25761b6e | 230 | { |
de491861 | 231 | struct page *page; |
25761b6e RW |
232 | |
233 | if (!pfn_valid(pfn)) | |
ae83c5ee | 234 | return NULL; |
25761b6e RW |
235 | |
236 | page = pfn_to_page(pfn); | |
ae83c5ee | 237 | |
25761b6e | 238 | if (PageNosave(page)) |
ae83c5ee | 239 | return NULL; |
72a97e08 | 240 | if (PageReserved(page) && pfn_is_nosave(pfn)) |
ae83c5ee | 241 | return NULL; |
25761b6e | 242 | if (PageNosaveFree(page)) |
ae83c5ee | 243 | return NULL; |
25761b6e | 244 | |
ae83c5ee | 245 | return page; |
25761b6e RW |
246 | } |
247 | ||
72a97e08 | 248 | unsigned int count_data_pages(void) |
25761b6e RW |
249 | { |
250 | struct zone *zone; | |
ae83c5ee | 251 | unsigned long pfn, max_zone_pfn; |
dc19d507 | 252 | unsigned int n = 0; |
25761b6e | 253 | |
25761b6e RW |
254 | for_each_zone (zone) { |
255 | if (is_highmem(zone)) | |
256 | continue; | |
257 | mark_free_pages(zone); | |
ae83c5ee RW |
258 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
259 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
260 | n += !!saveable_page(pfn); | |
25761b6e | 261 | } |
a0f49651 | 262 | return n; |
25761b6e RW |
263 | } |
264 | ||
f623f0db RW |
265 | static inline void copy_data_page(long *dst, long *src) |
266 | { | |
267 | int n; | |
268 | ||
269 | /* copy_page and memcpy are not usable for copying task structs. */ | |
270 | for (n = PAGE_SIZE / sizeof(long); n; n--) | |
271 | *dst++ = *src++; | |
272 | } | |
273 | ||
a0f49651 | 274 | static void copy_data_pages(struct pbe *pblist) |
25761b6e RW |
275 | { |
276 | struct zone *zone; | |
ae83c5ee | 277 | unsigned long pfn, max_zone_pfn; |
f623f0db | 278 | struct pbe *pbe; |
25761b6e | 279 | |
a0f49651 | 280 | pbe = pblist; |
25761b6e RW |
281 | for_each_zone (zone) { |
282 | if (is_highmem(zone)) | |
283 | continue; | |
284 | mark_free_pages(zone); | |
ae83c5ee RW |
285 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
286 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { | |
287 | struct page *page = saveable_page(pfn); | |
288 | ||
289 | if (page) { | |
f623f0db | 290 | void *ptr = page_address(page); |
95018f7c | 291 | |
25761b6e | 292 | BUG_ON(!pbe); |
f623f0db RW |
293 | copy_data_page((void *)pbe->address, ptr); |
294 | pbe->orig_address = (unsigned long)ptr; | |
25761b6e RW |
295 | pbe = pbe->next; |
296 | } | |
297 | } | |
298 | } | |
299 | BUG_ON(pbe); | |
300 | } | |
301 | ||
25761b6e RW |
302 | /** |
303 | * free_pagedir - free pages allocated with alloc_pagedir() | |
304 | */ | |
305 | ||
4a3b98a4 | 306 | static void free_pagedir(struct pbe *pblist, int clear_nosave_free) |
25761b6e RW |
307 | { |
308 | struct pbe *pbe; | |
309 | ||
310 | while (pblist) { | |
311 | pbe = (pblist + PB_PAGE_SKIP)->next; | |
f6143aa6 | 312 | free_image_page(pblist, clear_nosave_free); |
25761b6e RW |
313 | pblist = pbe; |
314 | } | |
315 | } | |
316 | ||
317 | /** | |
318 | * fill_pb_page - Create a list of PBEs on a given memory page | |
319 | */ | |
320 | ||
cd560bb2 | 321 | static inline void fill_pb_page(struct pbe *pbpage, unsigned int n) |
25761b6e RW |
322 | { |
323 | struct pbe *p; | |
324 | ||
325 | p = pbpage; | |
cd560bb2 | 326 | pbpage += n - 1; |
25761b6e RW |
327 | do |
328 | p->next = p + 1; | |
329 | while (++p < pbpage); | |
330 | } | |
331 | ||
332 | /** | |
333 | * create_pbe_list - Create a list of PBEs on top of a given chain | |
334 | * of memory pages allocated with alloc_pagedir() | |
cd560bb2 RW |
335 | * |
336 | * This function assumes that pages allocated by alloc_image_page() will | |
337 | * always be zeroed. | |
25761b6e RW |
338 | */ |
339 | ||
7088a5c0 | 340 | static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) |
25761b6e | 341 | { |
cd560bb2 | 342 | struct pbe *pbpage; |
dc19d507 | 343 | unsigned int num = PBES_PER_PAGE; |
25761b6e RW |
344 | |
345 | for_each_pb_page (pbpage, pblist) { | |
346 | if (num >= nr_pages) | |
347 | break; | |
348 | ||
cd560bb2 | 349 | fill_pb_page(pbpage, PBES_PER_PAGE); |
25761b6e RW |
350 | num += PBES_PER_PAGE; |
351 | } | |
352 | if (pbpage) { | |
cd560bb2 RW |
353 | num -= PBES_PER_PAGE; |
354 | fill_pb_page(pbpage, nr_pages - num); | |
25761b6e | 355 | } |
25761b6e RW |
356 | } |
357 | ||
25761b6e RW |
358 | /** |
359 | * alloc_pagedir - Allocate the page directory. | |
360 | * | |
361 | * First, determine exactly how many pages we need and | |
362 | * allocate them. | |
363 | * | |
364 | * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE | |
365 | * struct pbe elements (pbes) and the last element in the page points | |
366 | * to the next page. | |
367 | * | |
368 | * On each page we set up a list of struct_pbe elements. | |
369 | */ | |
370 | ||
7bff24e2 AB |
371 | static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, |
372 | int safe_needed) | |
25761b6e | 373 | { |
dc19d507 | 374 | unsigned int num; |
25761b6e RW |
375 | struct pbe *pblist, *pbe; |
376 | ||
377 | if (!nr_pages) | |
378 | return NULL; | |
379 | ||
054bd4c1 | 380 | pblist = alloc_image_page(gfp_mask, safe_needed); |
cd560bb2 RW |
381 | pbe = pblist; |
382 | for (num = PBES_PER_PAGE; num < nr_pages; num += PBES_PER_PAGE) { | |
383 | if (!pbe) { | |
384 | free_pagedir(pblist, 1); | |
385 | return NULL; | |
386 | } | |
25761b6e | 387 | pbe += PB_PAGE_SKIP; |
054bd4c1 | 388 | pbe->next = alloc_image_page(gfp_mask, safe_needed); |
cd560bb2 | 389 | pbe = pbe->next; |
25761b6e | 390 | } |
cd560bb2 | 391 | create_pbe_list(pblist, nr_pages); |
25761b6e RW |
392 | return pblist; |
393 | } | |
394 | ||
395 | /** | |
396 | * Free pages we allocated for suspend. Suspend pages are alocated | |
397 | * before atomic copy, so we need to free them after resume. | |
398 | */ | |
399 | ||
400 | void swsusp_free(void) | |
401 | { | |
402 | struct zone *zone; | |
ae83c5ee | 403 | unsigned long pfn, max_zone_pfn; |
25761b6e RW |
404 | |
405 | for_each_zone(zone) { | |
ae83c5ee RW |
406 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
407 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
408 | if (pfn_valid(pfn)) { | |
409 | struct page *page = pfn_to_page(pfn); | |
410 | ||
25761b6e RW |
411 | if (PageNosave(page) && PageNosaveFree(page)) { |
412 | ClearPageNosave(page); | |
413 | ClearPageNosaveFree(page); | |
414 | free_page((long) page_address(page)); | |
415 | } | |
416 | } | |
417 | } | |
f577eb30 RW |
418 | nr_copy_pages = 0; |
419 | nr_meta_pages = 0; | |
75534b50 | 420 | restore_pblist = NULL; |
6e1819d6 | 421 | buffer = NULL; |
25761b6e RW |
422 | } |
423 | ||
424 | ||
425 | /** | |
426 | * enough_free_mem - Make sure we enough free memory to snapshot. | |
427 | * | |
428 | * Returns TRUE or FALSE after checking the number of available | |
429 | * free pages. | |
430 | */ | |
431 | ||
dc19d507 | 432 | static int enough_free_mem(unsigned int nr_pages) |
25761b6e | 433 | { |
e5e2fa78 RW |
434 | struct zone *zone; |
435 | unsigned int n = 0; | |
436 | ||
437 | for_each_zone (zone) | |
438 | if (!is_highmem(zone)) | |
439 | n += zone->free_pages; | |
440 | pr_debug("swsusp: available memory: %u pages\n", n); | |
441 | return n > (nr_pages + PAGES_FOR_IO + | |
a0f49651 | 442 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); |
25761b6e RW |
443 | } |
444 | ||
f577eb30 | 445 | static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) |
054bd4c1 RW |
446 | { |
447 | struct pbe *p; | |
448 | ||
449 | for_each_pbe (p, pblist) { | |
450 | p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); | |
451 | if (!p->address) | |
452 | return -ENOMEM; | |
453 | } | |
454 | return 0; | |
455 | } | |
25761b6e | 456 | |
dc19d507 | 457 | static struct pbe *swsusp_alloc(unsigned int nr_pages) |
25761b6e | 458 | { |
054bd4c1 | 459 | struct pbe *pblist; |
25761b6e | 460 | |
054bd4c1 | 461 | if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) { |
25761b6e | 462 | printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); |
a0f49651 | 463 | return NULL; |
25761b6e | 464 | } |
25761b6e | 465 | |
054bd4c1 RW |
466 | if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) { |
467 | printk(KERN_ERR "suspend: Allocating image pages failed.\n"); | |
468 | swsusp_free(); | |
469 | return NULL; | |
25761b6e RW |
470 | } |
471 | ||
a0f49651 | 472 | return pblist; |
25761b6e RW |
473 | } |
474 | ||
2e32a43e | 475 | asmlinkage int swsusp_save(void) |
25761b6e | 476 | { |
dc19d507 | 477 | unsigned int nr_pages; |
25761b6e RW |
478 | |
479 | pr_debug("swsusp: critical section: \n"); | |
25761b6e RW |
480 | |
481 | drain_local_pages(); | |
a0f49651 RW |
482 | nr_pages = count_data_pages(); |
483 | printk("swsusp: Need to copy %u pages\n", nr_pages); | |
25761b6e RW |
484 | |
485 | pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", | |
a0f49651 RW |
486 | nr_pages, |
487 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, | |
25761b6e RW |
488 | PAGES_FOR_IO, nr_free_pages()); |
489 | ||
a0f49651 | 490 | if (!enough_free_mem(nr_pages)) { |
25761b6e RW |
491 | printk(KERN_ERR "swsusp: Not enough free memory\n"); |
492 | return -ENOMEM; | |
493 | } | |
494 | ||
75534b50 RW |
495 | restore_pblist = swsusp_alloc(nr_pages); |
496 | if (!restore_pblist) | |
a0f49651 | 497 | return -ENOMEM; |
25761b6e RW |
498 | |
499 | /* During allocating of suspend pagedir, new cold pages may appear. | |
500 | * Kill them. | |
501 | */ | |
502 | drain_local_pages(); | |
75534b50 | 503 | copy_data_pages(restore_pblist); |
25761b6e RW |
504 | |
505 | /* | |
506 | * End of critical section. From now on, we can write to memory, | |
507 | * but we should not touch disk. This specially means we must _not_ | |
508 | * touch swap space! Except we must write out our image of course. | |
509 | */ | |
510 | ||
a0f49651 | 511 | nr_copy_pages = nr_pages; |
f577eb30 | 512 | nr_meta_pages = (nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
a0f49651 RW |
513 | |
514 | printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); | |
25761b6e RW |
515 | return 0; |
516 | } | |
f577eb30 RW |
517 | |
518 | static void init_header(struct swsusp_info *info) | |
519 | { | |
520 | memset(info, 0, sizeof(struct swsusp_info)); | |
521 | info->version_code = LINUX_VERSION_CODE; | |
522 | info->num_physpages = num_physpages; | |
523 | memcpy(&info->uts, &system_utsname, sizeof(system_utsname)); | |
524 | info->cpus = num_online_cpus(); | |
525 | info->image_pages = nr_copy_pages; | |
526 | info->pages = nr_copy_pages + nr_meta_pages + 1; | |
6e1819d6 RW |
527 | info->size = info->pages; |
528 | info->size <<= PAGE_SHIFT; | |
f577eb30 RW |
529 | } |
530 | ||
531 | /** | |
532 | * pack_orig_addresses - the .orig_address fields of the PBEs from the | |
533 | * list starting at @pbe are stored in the array @buf[] (1 page) | |
534 | */ | |
535 | ||
536 | static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe) | |
537 | { | |
538 | int j; | |
539 | ||
540 | for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { | |
541 | buf[j] = pbe->orig_address; | |
542 | pbe = pbe->next; | |
543 | } | |
544 | if (!pbe) | |
545 | for (; j < PAGE_SIZE / sizeof(long); j++) | |
546 | buf[j] = 0; | |
547 | return pbe; | |
548 | } | |
549 | ||
550 | /** | |
551 | * snapshot_read_next - used for reading the system memory snapshot. | |
552 | * | |
553 | * On the first call to it @handle should point to a zeroed | |
554 | * snapshot_handle structure. The structure gets updated and a pointer | |
555 | * to it should be passed to this function every next time. | |
556 | * | |
557 | * The @count parameter should contain the number of bytes the caller | |
558 | * wants to read from the snapshot. It must not be zero. | |
559 | * | |
560 | * On success the function returns a positive number. Then, the caller | |
561 | * is allowed to read up to the returned number of bytes from the memory | |
562 | * location computed by the data_of() macro. The number returned | |
563 | * may be smaller than @count, but this only happens if the read would | |
564 | * cross a page boundary otherwise. | |
565 | * | |
566 | * The function returns 0 to indicate the end of data stream condition, | |
567 | * and a negative number is returned on error. In such cases the | |
568 | * structure pointed to by @handle is not updated and should not be used | |
569 | * any more. | |
570 | */ | |
571 | ||
572 | int snapshot_read_next(struct snapshot_handle *handle, size_t count) | |
573 | { | |
fb13a28b | 574 | if (handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 RW |
575 | return 0; |
576 | if (!buffer) { | |
577 | /* This makes the buffer be freed by swsusp_free() */ | |
578 | buffer = alloc_image_page(GFP_ATOMIC, 0); | |
579 | if (!buffer) | |
580 | return -ENOMEM; | |
581 | } | |
582 | if (!handle->offset) { | |
583 | init_header((struct swsusp_info *)buffer); | |
584 | handle->buffer = buffer; | |
75534b50 | 585 | handle->pbe = restore_pblist; |
f577eb30 | 586 | } |
fb13a28b RW |
587 | if (handle->prev < handle->cur) { |
588 | if (handle->cur <= nr_meta_pages) { | |
f577eb30 RW |
589 | handle->pbe = pack_orig_addresses(buffer, handle->pbe); |
590 | if (!handle->pbe) | |
75534b50 | 591 | handle->pbe = restore_pblist; |
f577eb30 RW |
592 | } else { |
593 | handle->buffer = (void *)handle->pbe->address; | |
594 | handle->pbe = handle->pbe->next; | |
595 | } | |
fb13a28b | 596 | handle->prev = handle->cur; |
f577eb30 | 597 | } |
fb13a28b RW |
598 | handle->buf_offset = handle->cur_offset; |
599 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
600 | count = PAGE_SIZE - handle->cur_offset; | |
601 | handle->cur_offset = 0; | |
602 | handle->cur++; | |
f577eb30 | 603 | } else { |
fb13a28b | 604 | handle->cur_offset += count; |
f577eb30 RW |
605 | } |
606 | handle->offset += count; | |
607 | return count; | |
608 | } | |
609 | ||
610 | /** | |
611 | * mark_unsafe_pages - mark the pages that cannot be used for storing | |
612 | * the image during resume, because they conflict with the pages that | |
613 | * had been used before suspend | |
614 | */ | |
615 | ||
616 | static int mark_unsafe_pages(struct pbe *pblist) | |
617 | { | |
618 | struct zone *zone; | |
ae83c5ee | 619 | unsigned long pfn, max_zone_pfn; |
f577eb30 RW |
620 | struct pbe *p; |
621 | ||
622 | if (!pblist) /* a sanity check */ | |
623 | return -EINVAL; | |
624 | ||
625 | /* Clear page flags */ | |
626 | for_each_zone (zone) { | |
ae83c5ee RW |
627 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
628 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
629 | if (pfn_valid(pfn)) | |
630 | ClearPageNosaveFree(pfn_to_page(pfn)); | |
f577eb30 RW |
631 | } |
632 | ||
633 | /* Mark orig addresses */ | |
634 | for_each_pbe (p, pblist) { | |
635 | if (virt_addr_valid(p->orig_address)) | |
636 | SetPageNosaveFree(virt_to_page(p->orig_address)); | |
637 | else | |
638 | return -EFAULT; | |
639 | } | |
640 | ||
968808b8 RW |
641 | unsafe_pages = 0; |
642 | ||
f577eb30 RW |
643 | return 0; |
644 | } | |
645 | ||
646 | static void copy_page_backup_list(struct pbe *dst, struct pbe *src) | |
647 | { | |
648 | /* We assume both lists contain the same number of elements */ | |
649 | while (src) { | |
650 | dst->orig_address = src->orig_address; | |
651 | dst = dst->next; | |
652 | src = src->next; | |
653 | } | |
654 | } | |
655 | ||
656 | static int check_header(struct swsusp_info *info) | |
657 | { | |
658 | char *reason = NULL; | |
659 | ||
660 | if (info->version_code != LINUX_VERSION_CODE) | |
661 | reason = "kernel version"; | |
662 | if (info->num_physpages != num_physpages) | |
663 | reason = "memory size"; | |
664 | if (strcmp(info->uts.sysname,system_utsname.sysname)) | |
665 | reason = "system type"; | |
666 | if (strcmp(info->uts.release,system_utsname.release)) | |
667 | reason = "kernel release"; | |
668 | if (strcmp(info->uts.version,system_utsname.version)) | |
669 | reason = "version"; | |
670 | if (strcmp(info->uts.machine,system_utsname.machine)) | |
671 | reason = "machine"; | |
672 | if (reason) { | |
673 | printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason); | |
674 | return -EPERM; | |
675 | } | |
676 | return 0; | |
677 | } | |
678 | ||
679 | /** | |
680 | * load header - check the image header and copy data from it | |
681 | */ | |
682 | ||
683 | static int load_header(struct snapshot_handle *handle, | |
684 | struct swsusp_info *info) | |
685 | { | |
686 | int error; | |
687 | struct pbe *pblist; | |
688 | ||
689 | error = check_header(info); | |
690 | if (!error) { | |
691 | pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, 0); | |
692 | if (!pblist) | |
693 | return -ENOMEM; | |
75534b50 | 694 | restore_pblist = pblist; |
f577eb30 RW |
695 | handle->pbe = pblist; |
696 | nr_copy_pages = info->image_pages; | |
697 | nr_meta_pages = info->pages - info->image_pages - 1; | |
698 | } | |
699 | return error; | |
700 | } | |
701 | ||
702 | /** | |
703 | * unpack_orig_addresses - copy the elements of @buf[] (1 page) to | |
704 | * the PBEs in the list starting at @pbe | |
705 | */ | |
706 | ||
707 | static inline struct pbe *unpack_orig_addresses(unsigned long *buf, | |
708 | struct pbe *pbe) | |
709 | { | |
710 | int j; | |
711 | ||
712 | for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { | |
713 | pbe->orig_address = buf[j]; | |
714 | pbe = pbe->next; | |
715 | } | |
716 | return pbe; | |
717 | } | |
718 | ||
719 | /** | |
968808b8 | 720 | * prepare_image - use metadata contained in the PBE list |
75534b50 | 721 | * pointed to by restore_pblist to mark the pages that will |
f577eb30 | 722 | * be overwritten in the process of restoring the system |
968808b8 RW |
723 | * memory state from the image ("unsafe" pages) and allocate |
724 | * memory for the image | |
725 | * | |
726 | * The idea is to allocate the PBE list first and then | |
727 | * allocate as many pages as it's needed for the image data, | |
728 | * but not to assign these pages to the PBEs initially. | |
729 | * Instead, we just mark them as allocated and create a list | |
730 | * of "safe" which will be used later | |
f577eb30 RW |
731 | */ |
732 | ||
968808b8 RW |
733 | struct safe_page { |
734 | struct safe_page *next; | |
735 | char padding[PAGE_SIZE - sizeof(void *)]; | |
736 | }; | |
737 | ||
738 | static struct safe_page *safe_pages; | |
739 | ||
740 | static int prepare_image(struct snapshot_handle *handle) | |
f577eb30 RW |
741 | { |
742 | int error = 0; | |
968808b8 RW |
743 | unsigned int nr_pages = nr_copy_pages; |
744 | struct pbe *p, *pblist = NULL; | |
f577eb30 | 745 | |
75534b50 | 746 | p = restore_pblist; |
f577eb30 RW |
747 | error = mark_unsafe_pages(p); |
748 | if (!error) { | |
968808b8 | 749 | pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1); |
f577eb30 RW |
750 | if (pblist) |
751 | copy_page_backup_list(pblist, p); | |
4a3b98a4 | 752 | free_pagedir(p, 0); |
f577eb30 RW |
753 | if (!pblist) |
754 | error = -ENOMEM; | |
755 | } | |
968808b8 RW |
756 | safe_pages = NULL; |
757 | if (!error && nr_pages > unsafe_pages) { | |
758 | nr_pages -= unsafe_pages; | |
759 | while (nr_pages--) { | |
760 | struct safe_page *ptr; | |
761 | ||
762 | ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC); | |
763 | if (!ptr) { | |
764 | error = -ENOMEM; | |
765 | break; | |
766 | } | |
767 | if (!PageNosaveFree(virt_to_page(ptr))) { | |
768 | /* The page is "safe", add it to the list */ | |
769 | ptr->next = safe_pages; | |
770 | safe_pages = ptr; | |
771 | } | |
772 | /* Mark the page as allocated */ | |
773 | SetPageNosave(virt_to_page(ptr)); | |
774 | SetPageNosaveFree(virt_to_page(ptr)); | |
775 | } | |
776 | } | |
f577eb30 | 777 | if (!error) { |
75534b50 | 778 | restore_pblist = pblist; |
f577eb30 | 779 | } else { |
f577eb30 | 780 | handle->pbe = NULL; |
968808b8 | 781 | swsusp_free(); |
f577eb30 RW |
782 | } |
783 | return error; | |
784 | } | |
785 | ||
968808b8 RW |
786 | static void *get_buffer(struct snapshot_handle *handle) |
787 | { | |
788 | struct pbe *pbe = handle->pbe, *last = handle->last_pbe; | |
789 | struct page *page = virt_to_page(pbe->orig_address); | |
790 | ||
791 | if (PageNosave(page) && PageNosaveFree(page)) { | |
792 | /* | |
793 | * We have allocated the "original" page frame and we can | |
794 | * use it directly to store the read page | |
795 | */ | |
796 | pbe->address = 0; | |
797 | if (last && last->next) | |
798 | last->next = NULL; | |
799 | return (void *)pbe->orig_address; | |
800 | } | |
801 | /* | |
802 | * The "original" page frame has not been allocated and we have to | |
803 | * use a "safe" page frame to store the read page | |
804 | */ | |
805 | pbe->address = (unsigned long)safe_pages; | |
806 | safe_pages = safe_pages->next; | |
807 | if (last) | |
808 | last->next = pbe; | |
809 | handle->last_pbe = pbe; | |
810 | return (void *)pbe->address; | |
811 | } | |
812 | ||
f577eb30 RW |
813 | /** |
814 | * snapshot_write_next - used for writing the system memory snapshot. | |
815 | * | |
816 | * On the first call to it @handle should point to a zeroed | |
817 | * snapshot_handle structure. The structure gets updated and a pointer | |
818 | * to it should be passed to this function every next time. | |
819 | * | |
820 | * The @count parameter should contain the number of bytes the caller | |
821 | * wants to write to the image. It must not be zero. | |
822 | * | |
823 | * On success the function returns a positive number. Then, the caller | |
824 | * is allowed to write up to the returned number of bytes to the memory | |
825 | * location computed by the data_of() macro. The number returned | |
826 | * may be smaller than @count, but this only happens if the write would | |
827 | * cross a page boundary otherwise. | |
828 | * | |
829 | * The function returns 0 to indicate the "end of file" condition, | |
830 | * and a negative number is returned on error. In such cases the | |
831 | * structure pointed to by @handle is not updated and should not be used | |
832 | * any more. | |
833 | */ | |
834 | ||
835 | int snapshot_write_next(struct snapshot_handle *handle, size_t count) | |
836 | { | |
f577eb30 RW |
837 | int error = 0; |
838 | ||
fb13a28b | 839 | if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 RW |
840 | return 0; |
841 | if (!buffer) { | |
842 | /* This makes the buffer be freed by swsusp_free() */ | |
843 | buffer = alloc_image_page(GFP_ATOMIC, 0); | |
844 | if (!buffer) | |
845 | return -ENOMEM; | |
846 | } | |
847 | if (!handle->offset) | |
848 | handle->buffer = buffer; | |
546e0d27 | 849 | handle->sync_read = 1; |
fb13a28b | 850 | if (handle->prev < handle->cur) { |
f577eb30 | 851 | if (!handle->prev) { |
546e0d27 AM |
852 | error = load_header(handle, |
853 | (struct swsusp_info *)buffer); | |
f577eb30 RW |
854 | if (error) |
855 | return error; | |
856 | } else if (handle->prev <= nr_meta_pages) { | |
546e0d27 AM |
857 | handle->pbe = unpack_orig_addresses(buffer, |
858 | handle->pbe); | |
f577eb30 | 859 | if (!handle->pbe) { |
968808b8 | 860 | error = prepare_image(handle); |
f577eb30 RW |
861 | if (error) |
862 | return error; | |
75534b50 | 863 | handle->pbe = restore_pblist; |
968808b8 RW |
864 | handle->last_pbe = NULL; |
865 | handle->buffer = get_buffer(handle); | |
546e0d27 | 866 | handle->sync_read = 0; |
f577eb30 RW |
867 | } |
868 | } else { | |
869 | handle->pbe = handle->pbe->next; | |
968808b8 | 870 | handle->buffer = get_buffer(handle); |
546e0d27 | 871 | handle->sync_read = 0; |
f577eb30 | 872 | } |
fb13a28b | 873 | handle->prev = handle->cur; |
f577eb30 | 874 | } |
fb13a28b RW |
875 | handle->buf_offset = handle->cur_offset; |
876 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
877 | count = PAGE_SIZE - handle->cur_offset; | |
878 | handle->cur_offset = 0; | |
879 | handle->cur++; | |
f577eb30 | 880 | } else { |
fb13a28b | 881 | handle->cur_offset += count; |
f577eb30 RW |
882 | } |
883 | handle->offset += count; | |
884 | return count; | |
885 | } | |
886 | ||
887 | int snapshot_image_loaded(struct snapshot_handle *handle) | |
888 | { | |
889 | return !(!handle->pbe || handle->pbe->next || !nr_copy_pages || | |
fb13a28b | 890 | handle->cur <= nr_meta_pages + nr_copy_pages); |
f577eb30 | 891 | } |