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