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Commit | Line | Data |
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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 | ||
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 | ||
0bcd888d RW |
170 | #define PG_ANY 0 |
171 | #define PG_SAFE 1 | |
172 | #define PG_UNSAFE_CLEAR 1 | |
173 | #define PG_UNSAFE_KEEP 0 | |
174 | ||
f6143aa6 RW |
175 | static unsigned int unsafe_pages; |
176 | ||
177 | static void *alloc_image_page(gfp_t gfp_mask, int safe_needed) | |
178 | { | |
179 | void *res; | |
180 | ||
181 | res = (void *)get_zeroed_page(gfp_mask); | |
182 | if (safe_needed) | |
183 | while (res && PageNosaveFree(virt_to_page(res))) { | |
184 | /* The page is unsafe, mark it for swsusp_free() */ | |
185 | SetPageNosave(virt_to_page(res)); | |
186 | unsafe_pages++; | |
187 | res = (void *)get_zeroed_page(gfp_mask); | |
188 | } | |
189 | if (res) { | |
190 | SetPageNosave(virt_to_page(res)); | |
191 | SetPageNosaveFree(virt_to_page(res)); | |
192 | } | |
193 | return res; | |
194 | } | |
195 | ||
196 | unsigned long get_safe_page(gfp_t gfp_mask) | |
197 | { | |
0bcd888d | 198 | return (unsigned long)alloc_image_page(gfp_mask, PG_SAFE); |
f6143aa6 RW |
199 | } |
200 | ||
201 | /** | |
202 | * free_image_page - free page represented by @addr, allocated with | |
203 | * alloc_image_page (page flags set by it must be cleared) | |
204 | */ | |
205 | ||
206 | static inline void free_image_page(void *addr, int clear_nosave_free) | |
207 | { | |
208 | ClearPageNosave(virt_to_page(addr)); | |
209 | if (clear_nosave_free) | |
210 | ClearPageNosaveFree(virt_to_page(addr)); | |
211 | free_page((unsigned long)addr); | |
212 | } | |
213 | ||
214 | /** | |
215 | * pfn_is_nosave - check if given pfn is in the 'nosave' section | |
216 | */ | |
217 | ||
ae83c5ee | 218 | static inline int pfn_is_nosave(unsigned long pfn) |
25761b6e RW |
219 | { |
220 | unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; | |
221 | unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; | |
222 | return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); | |
223 | } | |
224 | ||
225 | /** | |
226 | * saveable - Determine whether a page should be cloned or not. | |
227 | * @pfn: The page | |
228 | * | |
ae83c5ee RW |
229 | * We save a page if it isn't Nosave, and is not in the range of pages |
230 | * statically defined as 'unsaveable', and it | |
231 | * isn't a part of a free chunk of pages. | |
25761b6e RW |
232 | */ |
233 | ||
ae83c5ee | 234 | static struct page *saveable_page(unsigned long pfn) |
25761b6e | 235 | { |
de491861 | 236 | struct page *page; |
25761b6e RW |
237 | |
238 | if (!pfn_valid(pfn)) | |
ae83c5ee | 239 | return NULL; |
25761b6e RW |
240 | |
241 | page = pfn_to_page(pfn); | |
ae83c5ee | 242 | |
25761b6e | 243 | if (PageNosave(page)) |
ae83c5ee | 244 | return NULL; |
72a97e08 | 245 | if (PageReserved(page) && pfn_is_nosave(pfn)) |
ae83c5ee | 246 | return NULL; |
25761b6e | 247 | if (PageNosaveFree(page)) |
ae83c5ee | 248 | return NULL; |
25761b6e | 249 | |
ae83c5ee | 250 | return page; |
25761b6e RW |
251 | } |
252 | ||
72a97e08 | 253 | unsigned int count_data_pages(void) |
25761b6e RW |
254 | { |
255 | struct zone *zone; | |
ae83c5ee | 256 | unsigned long pfn, max_zone_pfn; |
dc19d507 | 257 | unsigned int n = 0; |
25761b6e | 258 | |
25761b6e RW |
259 | for_each_zone (zone) { |
260 | if (is_highmem(zone)) | |
261 | continue; | |
262 | mark_free_pages(zone); | |
ae83c5ee RW |
263 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
264 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
265 | n += !!saveable_page(pfn); | |
25761b6e | 266 | } |
a0f49651 | 267 | return n; |
25761b6e RW |
268 | } |
269 | ||
f623f0db RW |
270 | static inline void copy_data_page(long *dst, long *src) |
271 | { | |
272 | int n; | |
273 | ||
274 | /* copy_page and memcpy are not usable for copying task structs. */ | |
275 | for (n = PAGE_SIZE / sizeof(long); n; n--) | |
276 | *dst++ = *src++; | |
277 | } | |
278 | ||
a0f49651 | 279 | static void copy_data_pages(struct pbe *pblist) |
25761b6e RW |
280 | { |
281 | struct zone *zone; | |
ae83c5ee | 282 | unsigned long pfn, max_zone_pfn; |
f623f0db | 283 | struct pbe *pbe; |
25761b6e | 284 | |
a0f49651 | 285 | pbe = pblist; |
25761b6e RW |
286 | for_each_zone (zone) { |
287 | if (is_highmem(zone)) | |
288 | continue; | |
289 | mark_free_pages(zone); | |
ae83c5ee RW |
290 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
291 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { | |
292 | struct page *page = saveable_page(pfn); | |
293 | ||
294 | if (page) { | |
f623f0db | 295 | void *ptr = page_address(page); |
95018f7c | 296 | |
25761b6e | 297 | BUG_ON(!pbe); |
f623f0db RW |
298 | copy_data_page((void *)pbe->address, ptr); |
299 | pbe->orig_address = (unsigned long)ptr; | |
25761b6e RW |
300 | pbe = pbe->next; |
301 | } | |
302 | } | |
303 | } | |
304 | BUG_ON(pbe); | |
305 | } | |
306 | ||
25761b6e RW |
307 | /** |
308 | * free_pagedir - free pages allocated with alloc_pagedir() | |
309 | */ | |
310 | ||
4a3b98a4 | 311 | static void free_pagedir(struct pbe *pblist, int clear_nosave_free) |
25761b6e RW |
312 | { |
313 | struct pbe *pbe; | |
314 | ||
315 | while (pblist) { | |
316 | pbe = (pblist + PB_PAGE_SKIP)->next; | |
f6143aa6 | 317 | free_image_page(pblist, clear_nosave_free); |
25761b6e RW |
318 | pblist = pbe; |
319 | } | |
320 | } | |
321 | ||
322 | /** | |
323 | * fill_pb_page - Create a list of PBEs on a given memory page | |
324 | */ | |
325 | ||
cd560bb2 | 326 | static inline void fill_pb_page(struct pbe *pbpage, unsigned int n) |
25761b6e RW |
327 | { |
328 | struct pbe *p; | |
329 | ||
330 | p = pbpage; | |
cd560bb2 | 331 | pbpage += n - 1; |
25761b6e RW |
332 | do |
333 | p->next = p + 1; | |
334 | while (++p < pbpage); | |
335 | } | |
336 | ||
337 | /** | |
338 | * create_pbe_list - Create a list of PBEs on top of a given chain | |
339 | * of memory pages allocated with alloc_pagedir() | |
cd560bb2 RW |
340 | * |
341 | * This function assumes that pages allocated by alloc_image_page() will | |
342 | * always be zeroed. | |
25761b6e RW |
343 | */ |
344 | ||
7088a5c0 | 345 | static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) |
25761b6e | 346 | { |
cd560bb2 | 347 | struct pbe *pbpage; |
dc19d507 | 348 | unsigned int num = PBES_PER_PAGE; |
25761b6e RW |
349 | |
350 | for_each_pb_page (pbpage, pblist) { | |
351 | if (num >= nr_pages) | |
352 | break; | |
353 | ||
cd560bb2 | 354 | fill_pb_page(pbpage, PBES_PER_PAGE); |
25761b6e RW |
355 | num += PBES_PER_PAGE; |
356 | } | |
357 | if (pbpage) { | |
cd560bb2 RW |
358 | num -= PBES_PER_PAGE; |
359 | fill_pb_page(pbpage, nr_pages - num); | |
25761b6e | 360 | } |
25761b6e RW |
361 | } |
362 | ||
25761b6e RW |
363 | /** |
364 | * alloc_pagedir - Allocate the page directory. | |
365 | * | |
366 | * First, determine exactly how many pages we need and | |
367 | * allocate them. | |
368 | * | |
369 | * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE | |
370 | * struct pbe elements (pbes) and the last element in the page points | |
371 | * to the next page. | |
372 | * | |
373 | * On each page we set up a list of struct_pbe elements. | |
374 | */ | |
375 | ||
7bff24e2 AB |
376 | static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, |
377 | int safe_needed) | |
25761b6e | 378 | { |
dc19d507 | 379 | unsigned int num; |
25761b6e RW |
380 | struct pbe *pblist, *pbe; |
381 | ||
382 | if (!nr_pages) | |
383 | return NULL; | |
384 | ||
054bd4c1 | 385 | pblist = alloc_image_page(gfp_mask, safe_needed); |
cd560bb2 RW |
386 | pbe = pblist; |
387 | for (num = PBES_PER_PAGE; num < nr_pages; num += PBES_PER_PAGE) { | |
388 | if (!pbe) { | |
0bcd888d | 389 | free_pagedir(pblist, PG_UNSAFE_CLEAR); |
cd560bb2 RW |
390 | return NULL; |
391 | } | |
25761b6e | 392 | pbe += PB_PAGE_SKIP; |
054bd4c1 | 393 | pbe->next = alloc_image_page(gfp_mask, safe_needed); |
cd560bb2 | 394 | pbe = pbe->next; |
25761b6e | 395 | } |
cd560bb2 | 396 | create_pbe_list(pblist, nr_pages); |
25761b6e RW |
397 | return pblist; |
398 | } | |
399 | ||
400 | /** | |
401 | * Free pages we allocated for suspend. Suspend pages are alocated | |
402 | * before atomic copy, so we need to free them after resume. | |
403 | */ | |
404 | ||
405 | void swsusp_free(void) | |
406 | { | |
407 | struct zone *zone; | |
ae83c5ee | 408 | unsigned long pfn, max_zone_pfn; |
25761b6e RW |
409 | |
410 | for_each_zone(zone) { | |
ae83c5ee RW |
411 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
412 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
413 | if (pfn_valid(pfn)) { | |
414 | struct page *page = pfn_to_page(pfn); | |
415 | ||
25761b6e RW |
416 | if (PageNosave(page) && PageNosaveFree(page)) { |
417 | ClearPageNosave(page); | |
418 | ClearPageNosaveFree(page); | |
419 | free_page((long) page_address(page)); | |
420 | } | |
421 | } | |
422 | } | |
f577eb30 RW |
423 | nr_copy_pages = 0; |
424 | nr_meta_pages = 0; | |
75534b50 | 425 | restore_pblist = NULL; |
6e1819d6 | 426 | buffer = NULL; |
25761b6e RW |
427 | } |
428 | ||
429 | ||
430 | /** | |
431 | * enough_free_mem - Make sure we enough free memory to snapshot. | |
432 | * | |
433 | * Returns TRUE or FALSE after checking the number of available | |
434 | * free pages. | |
435 | */ | |
436 | ||
dc19d507 | 437 | static int enough_free_mem(unsigned int nr_pages) |
25761b6e | 438 | { |
e5e2fa78 RW |
439 | struct zone *zone; |
440 | unsigned int n = 0; | |
441 | ||
442 | for_each_zone (zone) | |
443 | if (!is_highmem(zone)) | |
444 | n += zone->free_pages; | |
445 | pr_debug("swsusp: available memory: %u pages\n", n); | |
446 | return n > (nr_pages + PAGES_FOR_IO + | |
a0f49651 | 447 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); |
25761b6e RW |
448 | } |
449 | ||
f577eb30 | 450 | static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) |
054bd4c1 RW |
451 | { |
452 | struct pbe *p; | |
453 | ||
454 | for_each_pbe (p, pblist) { | |
455 | p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); | |
456 | if (!p->address) | |
457 | return -ENOMEM; | |
458 | } | |
459 | return 0; | |
460 | } | |
25761b6e | 461 | |
dc19d507 | 462 | static struct pbe *swsusp_alloc(unsigned int nr_pages) |
25761b6e | 463 | { |
054bd4c1 | 464 | struct pbe *pblist; |
25761b6e | 465 | |
0bcd888d RW |
466 | pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, PG_ANY); |
467 | if (!pblist) { | |
25761b6e | 468 | printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); |
a0f49651 | 469 | return NULL; |
25761b6e | 470 | } |
25761b6e | 471 | |
0bcd888d | 472 | if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, PG_ANY)) { |
054bd4c1 RW |
473 | printk(KERN_ERR "suspend: Allocating image pages failed.\n"); |
474 | swsusp_free(); | |
475 | return NULL; | |
25761b6e RW |
476 | } |
477 | ||
a0f49651 | 478 | return pblist; |
25761b6e RW |
479 | } |
480 | ||
2e32a43e | 481 | asmlinkage int swsusp_save(void) |
25761b6e | 482 | { |
dc19d507 | 483 | unsigned int nr_pages; |
25761b6e RW |
484 | |
485 | pr_debug("swsusp: critical section: \n"); | |
25761b6e RW |
486 | |
487 | drain_local_pages(); | |
a0f49651 RW |
488 | nr_pages = count_data_pages(); |
489 | printk("swsusp: Need to copy %u pages\n", nr_pages); | |
25761b6e RW |
490 | |
491 | pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", | |
a0f49651 RW |
492 | nr_pages, |
493 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, | |
25761b6e RW |
494 | PAGES_FOR_IO, nr_free_pages()); |
495 | ||
a0f49651 | 496 | if (!enough_free_mem(nr_pages)) { |
25761b6e RW |
497 | printk(KERN_ERR "swsusp: Not enough free memory\n"); |
498 | return -ENOMEM; | |
499 | } | |
500 | ||
75534b50 RW |
501 | restore_pblist = swsusp_alloc(nr_pages); |
502 | if (!restore_pblist) | |
a0f49651 | 503 | return -ENOMEM; |
25761b6e RW |
504 | |
505 | /* During allocating of suspend pagedir, new cold pages may appear. | |
506 | * Kill them. | |
507 | */ | |
508 | drain_local_pages(); | |
75534b50 | 509 | copy_data_pages(restore_pblist); |
25761b6e RW |
510 | |
511 | /* | |
512 | * End of critical section. From now on, we can write to memory, | |
513 | * but we should not touch disk. This specially means we must _not_ | |
514 | * touch swap space! Except we must write out our image of course. | |
515 | */ | |
516 | ||
a0f49651 | 517 | nr_copy_pages = nr_pages; |
f577eb30 | 518 | nr_meta_pages = (nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
a0f49651 RW |
519 | |
520 | printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); | |
25761b6e RW |
521 | return 0; |
522 | } | |
f577eb30 RW |
523 | |
524 | static void init_header(struct swsusp_info *info) | |
525 | { | |
526 | memset(info, 0, sizeof(struct swsusp_info)); | |
527 | info->version_code = LINUX_VERSION_CODE; | |
528 | info->num_physpages = num_physpages; | |
529 | memcpy(&info->uts, &system_utsname, sizeof(system_utsname)); | |
530 | info->cpus = num_online_cpus(); | |
531 | info->image_pages = nr_copy_pages; | |
532 | info->pages = nr_copy_pages + nr_meta_pages + 1; | |
6e1819d6 RW |
533 | info->size = info->pages; |
534 | info->size <<= PAGE_SHIFT; | |
f577eb30 RW |
535 | } |
536 | ||
537 | /** | |
538 | * pack_orig_addresses - the .orig_address fields of the PBEs from the | |
539 | * list starting at @pbe are stored in the array @buf[] (1 page) | |
540 | */ | |
541 | ||
542 | static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe) | |
543 | { | |
544 | int j; | |
545 | ||
546 | for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { | |
547 | buf[j] = pbe->orig_address; | |
548 | pbe = pbe->next; | |
549 | } | |
550 | if (!pbe) | |
551 | for (; j < PAGE_SIZE / sizeof(long); j++) | |
552 | buf[j] = 0; | |
553 | return pbe; | |
554 | } | |
555 | ||
556 | /** | |
557 | * snapshot_read_next - used for reading the system memory snapshot. | |
558 | * | |
559 | * On the first call to it @handle should point to a zeroed | |
560 | * snapshot_handle structure. The structure gets updated and a pointer | |
561 | * to it should be passed to this function every next time. | |
562 | * | |
563 | * The @count parameter should contain the number of bytes the caller | |
564 | * wants to read from the snapshot. It must not be zero. | |
565 | * | |
566 | * On success the function returns a positive number. Then, the caller | |
567 | * is allowed to read up to the returned number of bytes from the memory | |
568 | * location computed by the data_of() macro. The number returned | |
569 | * may be smaller than @count, but this only happens if the read would | |
570 | * cross a page boundary otherwise. | |
571 | * | |
572 | * The function returns 0 to indicate the end of data stream condition, | |
573 | * and a negative number is returned on error. In such cases the | |
574 | * structure pointed to by @handle is not updated and should not be used | |
575 | * any more. | |
576 | */ | |
577 | ||
578 | int snapshot_read_next(struct snapshot_handle *handle, size_t count) | |
579 | { | |
fb13a28b | 580 | if (handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 RW |
581 | return 0; |
582 | if (!buffer) { | |
583 | /* This makes the buffer be freed by swsusp_free() */ | |
0bcd888d | 584 | buffer = alloc_image_page(GFP_ATOMIC, PG_ANY); |
f577eb30 RW |
585 | if (!buffer) |
586 | return -ENOMEM; | |
587 | } | |
588 | if (!handle->offset) { | |
589 | init_header((struct swsusp_info *)buffer); | |
590 | handle->buffer = buffer; | |
75534b50 | 591 | handle->pbe = restore_pblist; |
f577eb30 | 592 | } |
fb13a28b RW |
593 | if (handle->prev < handle->cur) { |
594 | if (handle->cur <= nr_meta_pages) { | |
f577eb30 RW |
595 | handle->pbe = pack_orig_addresses(buffer, handle->pbe); |
596 | if (!handle->pbe) | |
75534b50 | 597 | handle->pbe = restore_pblist; |
f577eb30 RW |
598 | } else { |
599 | handle->buffer = (void *)handle->pbe->address; | |
600 | handle->pbe = handle->pbe->next; | |
601 | } | |
fb13a28b | 602 | handle->prev = handle->cur; |
f577eb30 | 603 | } |
fb13a28b RW |
604 | handle->buf_offset = handle->cur_offset; |
605 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
606 | count = PAGE_SIZE - handle->cur_offset; | |
607 | handle->cur_offset = 0; | |
608 | handle->cur++; | |
f577eb30 | 609 | } else { |
fb13a28b | 610 | handle->cur_offset += count; |
f577eb30 RW |
611 | } |
612 | handle->offset += count; | |
613 | return count; | |
614 | } | |
615 | ||
616 | /** | |
617 | * mark_unsafe_pages - mark the pages that cannot be used for storing | |
618 | * the image during resume, because they conflict with the pages that | |
619 | * had been used before suspend | |
620 | */ | |
621 | ||
622 | static int mark_unsafe_pages(struct pbe *pblist) | |
623 | { | |
624 | struct zone *zone; | |
ae83c5ee | 625 | unsigned long pfn, max_zone_pfn; |
f577eb30 RW |
626 | struct pbe *p; |
627 | ||
628 | if (!pblist) /* a sanity check */ | |
629 | return -EINVAL; | |
630 | ||
631 | /* Clear page flags */ | |
632 | for_each_zone (zone) { | |
ae83c5ee RW |
633 | max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
634 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
635 | if (pfn_valid(pfn)) | |
636 | ClearPageNosaveFree(pfn_to_page(pfn)); | |
f577eb30 RW |
637 | } |
638 | ||
639 | /* Mark orig addresses */ | |
640 | for_each_pbe (p, pblist) { | |
641 | if (virt_addr_valid(p->orig_address)) | |
642 | SetPageNosaveFree(virt_to_page(p->orig_address)); | |
643 | else | |
644 | return -EFAULT; | |
645 | } | |
646 | ||
968808b8 RW |
647 | unsafe_pages = 0; |
648 | ||
f577eb30 RW |
649 | return 0; |
650 | } | |
651 | ||
652 | static void copy_page_backup_list(struct pbe *dst, struct pbe *src) | |
653 | { | |
654 | /* We assume both lists contain the same number of elements */ | |
655 | while (src) { | |
656 | dst->orig_address = src->orig_address; | |
657 | dst = dst->next; | |
658 | src = src->next; | |
659 | } | |
660 | } | |
661 | ||
662 | static int check_header(struct swsusp_info *info) | |
663 | { | |
664 | char *reason = NULL; | |
665 | ||
666 | if (info->version_code != LINUX_VERSION_CODE) | |
667 | reason = "kernel version"; | |
668 | if (info->num_physpages != num_physpages) | |
669 | reason = "memory size"; | |
670 | if (strcmp(info->uts.sysname,system_utsname.sysname)) | |
671 | reason = "system type"; | |
672 | if (strcmp(info->uts.release,system_utsname.release)) | |
673 | reason = "kernel release"; | |
674 | if (strcmp(info->uts.version,system_utsname.version)) | |
675 | reason = "version"; | |
676 | if (strcmp(info->uts.machine,system_utsname.machine)) | |
677 | reason = "machine"; | |
678 | if (reason) { | |
679 | printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason); | |
680 | return -EPERM; | |
681 | } | |
682 | return 0; | |
683 | } | |
684 | ||
685 | /** | |
686 | * load header - check the image header and copy data from it | |
687 | */ | |
688 | ||
689 | static int load_header(struct snapshot_handle *handle, | |
690 | struct swsusp_info *info) | |
691 | { | |
692 | int error; | |
693 | struct pbe *pblist; | |
694 | ||
695 | error = check_header(info); | |
696 | if (!error) { | |
0bcd888d | 697 | pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, PG_ANY); |
f577eb30 RW |
698 | if (!pblist) |
699 | return -ENOMEM; | |
75534b50 | 700 | restore_pblist = pblist; |
f577eb30 RW |
701 | handle->pbe = pblist; |
702 | nr_copy_pages = info->image_pages; | |
703 | nr_meta_pages = info->pages - info->image_pages - 1; | |
704 | } | |
705 | return error; | |
706 | } | |
707 | ||
708 | /** | |
709 | * unpack_orig_addresses - copy the elements of @buf[] (1 page) to | |
710 | * the PBEs in the list starting at @pbe | |
711 | */ | |
712 | ||
713 | static inline struct pbe *unpack_orig_addresses(unsigned long *buf, | |
714 | struct pbe *pbe) | |
715 | { | |
716 | int j; | |
717 | ||
718 | for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { | |
719 | pbe->orig_address = buf[j]; | |
720 | pbe = pbe->next; | |
721 | } | |
722 | return pbe; | |
723 | } | |
724 | ||
725 | /** | |
968808b8 | 726 | * prepare_image - use metadata contained in the PBE list |
75534b50 | 727 | * pointed to by restore_pblist to mark the pages that will |
f577eb30 | 728 | * be overwritten in the process of restoring the system |
968808b8 RW |
729 | * memory state from the image ("unsafe" pages) and allocate |
730 | * memory for the image | |
731 | * | |
732 | * The idea is to allocate the PBE list first and then | |
733 | * allocate as many pages as it's needed for the image data, | |
734 | * but not to assign these pages to the PBEs initially. | |
735 | * Instead, we just mark them as allocated and create a list | |
736 | * of "safe" which will be used later | |
f577eb30 RW |
737 | */ |
738 | ||
968808b8 RW |
739 | struct safe_page { |
740 | struct safe_page *next; | |
741 | char padding[PAGE_SIZE - sizeof(void *)]; | |
742 | }; | |
743 | ||
744 | static struct safe_page *safe_pages; | |
745 | ||
746 | static int prepare_image(struct snapshot_handle *handle) | |
f577eb30 RW |
747 | { |
748 | int error = 0; | |
968808b8 RW |
749 | unsigned int nr_pages = nr_copy_pages; |
750 | struct pbe *p, *pblist = NULL; | |
f577eb30 | 751 | |
75534b50 | 752 | p = restore_pblist; |
f577eb30 RW |
753 | error = mark_unsafe_pages(p); |
754 | if (!error) { | |
0bcd888d | 755 | pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, PG_SAFE); |
f577eb30 RW |
756 | if (pblist) |
757 | copy_page_backup_list(pblist, p); | |
0bcd888d | 758 | free_pagedir(p, PG_UNSAFE_KEEP); |
f577eb30 RW |
759 | if (!pblist) |
760 | error = -ENOMEM; | |
761 | } | |
968808b8 RW |
762 | safe_pages = NULL; |
763 | if (!error && nr_pages > unsafe_pages) { | |
764 | nr_pages -= unsafe_pages; | |
765 | while (nr_pages--) { | |
766 | struct safe_page *ptr; | |
767 | ||
768 | ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC); | |
769 | if (!ptr) { | |
770 | error = -ENOMEM; | |
771 | break; | |
772 | } | |
773 | if (!PageNosaveFree(virt_to_page(ptr))) { | |
774 | /* The page is "safe", add it to the list */ | |
775 | ptr->next = safe_pages; | |
776 | safe_pages = ptr; | |
777 | } | |
778 | /* Mark the page as allocated */ | |
779 | SetPageNosave(virt_to_page(ptr)); | |
780 | SetPageNosaveFree(virt_to_page(ptr)); | |
781 | } | |
782 | } | |
f577eb30 | 783 | if (!error) { |
75534b50 | 784 | restore_pblist = pblist; |
f577eb30 | 785 | } else { |
f577eb30 | 786 | handle->pbe = NULL; |
968808b8 | 787 | swsusp_free(); |
f577eb30 RW |
788 | } |
789 | return error; | |
790 | } | |
791 | ||
968808b8 RW |
792 | static void *get_buffer(struct snapshot_handle *handle) |
793 | { | |
794 | struct pbe *pbe = handle->pbe, *last = handle->last_pbe; | |
795 | struct page *page = virt_to_page(pbe->orig_address); | |
796 | ||
797 | if (PageNosave(page) && PageNosaveFree(page)) { | |
798 | /* | |
799 | * We have allocated the "original" page frame and we can | |
800 | * use it directly to store the read page | |
801 | */ | |
802 | pbe->address = 0; | |
803 | if (last && last->next) | |
804 | last->next = NULL; | |
805 | return (void *)pbe->orig_address; | |
806 | } | |
807 | /* | |
808 | * The "original" page frame has not been allocated and we have to | |
809 | * use a "safe" page frame to store the read page | |
810 | */ | |
811 | pbe->address = (unsigned long)safe_pages; | |
812 | safe_pages = safe_pages->next; | |
813 | if (last) | |
814 | last->next = pbe; | |
815 | handle->last_pbe = pbe; | |
816 | return (void *)pbe->address; | |
817 | } | |
818 | ||
f577eb30 RW |
819 | /** |
820 | * snapshot_write_next - used for writing the system memory snapshot. | |
821 | * | |
822 | * On the first call to it @handle should point to a zeroed | |
823 | * snapshot_handle structure. The structure gets updated and a pointer | |
824 | * to it should be passed to this function every next time. | |
825 | * | |
826 | * The @count parameter should contain the number of bytes the caller | |
827 | * wants to write to the image. It must not be zero. | |
828 | * | |
829 | * On success the function returns a positive number. Then, the caller | |
830 | * is allowed to write up to the returned number of bytes to the memory | |
831 | * location computed by the data_of() macro. The number returned | |
832 | * may be smaller than @count, but this only happens if the write would | |
833 | * cross a page boundary otherwise. | |
834 | * | |
835 | * The function returns 0 to indicate the "end of file" condition, | |
836 | * and a negative number is returned on error. In such cases the | |
837 | * structure pointed to by @handle is not updated and should not be used | |
838 | * any more. | |
839 | */ | |
840 | ||
841 | int snapshot_write_next(struct snapshot_handle *handle, size_t count) | |
842 | { | |
f577eb30 RW |
843 | int error = 0; |
844 | ||
fb13a28b | 845 | if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) |
f577eb30 RW |
846 | return 0; |
847 | if (!buffer) { | |
848 | /* This makes the buffer be freed by swsusp_free() */ | |
0bcd888d | 849 | buffer = alloc_image_page(GFP_ATOMIC, PG_ANY); |
f577eb30 RW |
850 | if (!buffer) |
851 | return -ENOMEM; | |
852 | } | |
853 | if (!handle->offset) | |
854 | handle->buffer = buffer; | |
546e0d27 | 855 | handle->sync_read = 1; |
fb13a28b | 856 | if (handle->prev < handle->cur) { |
f577eb30 | 857 | if (!handle->prev) { |
546e0d27 AM |
858 | error = load_header(handle, |
859 | (struct swsusp_info *)buffer); | |
f577eb30 RW |
860 | if (error) |
861 | return error; | |
862 | } else if (handle->prev <= nr_meta_pages) { | |
546e0d27 AM |
863 | handle->pbe = unpack_orig_addresses(buffer, |
864 | handle->pbe); | |
f577eb30 | 865 | if (!handle->pbe) { |
968808b8 | 866 | error = prepare_image(handle); |
f577eb30 RW |
867 | if (error) |
868 | return error; | |
75534b50 | 869 | handle->pbe = restore_pblist; |
968808b8 RW |
870 | handle->last_pbe = NULL; |
871 | handle->buffer = get_buffer(handle); | |
546e0d27 | 872 | handle->sync_read = 0; |
f577eb30 RW |
873 | } |
874 | } else { | |
875 | handle->pbe = handle->pbe->next; | |
968808b8 | 876 | handle->buffer = get_buffer(handle); |
546e0d27 | 877 | handle->sync_read = 0; |
f577eb30 | 878 | } |
fb13a28b | 879 | handle->prev = handle->cur; |
f577eb30 | 880 | } |
fb13a28b RW |
881 | handle->buf_offset = handle->cur_offset; |
882 | if (handle->cur_offset + count >= PAGE_SIZE) { | |
883 | count = PAGE_SIZE - handle->cur_offset; | |
884 | handle->cur_offset = 0; | |
885 | handle->cur++; | |
f577eb30 | 886 | } else { |
fb13a28b | 887 | handle->cur_offset += count; |
f577eb30 RW |
888 | } |
889 | handle->offset += count; | |
890 | return count; | |
891 | } | |
892 | ||
893 | int snapshot_image_loaded(struct snapshot_handle *handle) | |
894 | { | |
895 | return !(!handle->pbe || handle->pbe->next || !nr_copy_pages || | |
fb13a28b | 896 | handle->cur <= nr_meta_pages + nr_copy_pages); |
f577eb30 | 897 | } |