2 * linux/kernel/power/snapshot.c
4 * This file provide system snapshot/restore functionality.
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
8 * This file is released under the GPLv2, and is based on swsusp.c.
13 #include <linux/module.h>
15 #include <linux/suspend.h>
16 #include <linux/smp_lock.h>
17 #include <linux/delay.h>
18 #include <linux/bitops.h>
19 #include <linux/spinlock.h>
20 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/bootmem.h>
24 #include <linux/syscalls.h>
25 #include <linux/console.h>
26 #include <linux/highmem.h>
28 #include <asm/uaccess.h>
29 #include <asm/mmu_context.h>
30 #include <asm/pgtable.h>
31 #include <asm/tlbflush.h>
36 struct pbe *pagedir_nosave;
37 unsigned int nr_copy_pages;
40 unsigned int count_highmem_pages(void)
43 unsigned long zone_pfn;
47 if (is_highmem(zone)) {
48 mark_free_pages(zone);
49 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; zone_pfn++) {
51 unsigned long pfn = zone_pfn + zone->zone_start_pfn;
54 page = pfn_to_page(pfn);
55 if (PageReserved(page))
57 if (PageNosaveFree(page))
68 struct highmem_page *next;
71 static struct highmem_page *highmem_copy;
73 static int save_highmem_zone(struct zone *zone)
75 unsigned long zone_pfn;
76 mark_free_pages(zone);
77 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
79 struct highmem_page *save;
81 unsigned long pfn = zone_pfn + zone->zone_start_pfn;
87 page = pfn_to_page(pfn);
89 * This condition results from rvmalloc() sans vmalloc_32()
90 * and architectural memory reservations. This should be
91 * corrected eventually when the cases giving rise to this
92 * are better understood.
94 if (PageReserved(page))
96 BUG_ON(PageNosave(page));
97 if (PageNosaveFree(page))
99 save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
102 save->next = highmem_copy;
104 save->data = (void *) get_zeroed_page(GFP_ATOMIC);
109 kaddr = kmap_atomic(page, KM_USER0);
110 memcpy(save->data, kaddr, PAGE_SIZE);
111 kunmap_atomic(kaddr, KM_USER0);
117 int save_highmem(void)
122 pr_debug("swsusp: Saving Highmem\n");
123 for_each_zone (zone) {
124 if (is_highmem(zone))
125 res = save_highmem_zone(zone);
132 int restore_highmem(void)
134 printk("swsusp: Restoring Highmem\n");
135 while (highmem_copy) {
136 struct highmem_page *save = highmem_copy;
138 highmem_copy = save->next;
140 kaddr = kmap_atomic(save->page, KM_USER0);
141 memcpy(kaddr, save->data, PAGE_SIZE);
142 kunmap_atomic(kaddr, KM_USER0);
143 free_page((long) save->data);
150 static int pfn_is_nosave(unsigned long pfn)
152 unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
153 unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
154 return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
158 * saveable - Determine whether a page should be cloned or not.
161 * We save a page if it's Reserved, and not in the range of pages
162 * statically defined as 'unsaveable', or if it isn't reserved, and
163 * isn't part of a free chunk of pages.
166 static int saveable(struct zone *zone, unsigned long *zone_pfn)
168 unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
174 page = pfn_to_page(pfn);
175 BUG_ON(PageReserved(page) && PageNosave(page));
176 if (PageNosave(page))
178 if (PageReserved(page) && pfn_is_nosave(pfn))
180 if (PageNosaveFree(page))
186 unsigned int count_data_pages(void)
189 unsigned long zone_pfn;
192 for_each_zone (zone) {
193 if (is_highmem(zone))
195 mark_free_pages(zone);
196 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
197 n += saveable(zone, &zone_pfn);
202 static void copy_data_pages(struct pbe *pblist)
205 unsigned long zone_pfn;
209 for_each_zone (zone) {
210 if (is_highmem(zone))
212 mark_free_pages(zone);
213 /* This is necessary for swsusp_free() */
214 for_each_pb_page (p, pblist)
215 SetPageNosaveFree(virt_to_page(p));
216 for_each_pbe (p, pblist)
217 SetPageNosaveFree(virt_to_page(p->address));
218 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
219 if (saveable(zone, &zone_pfn)) {
221 page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
223 pbe->orig_address = (unsigned long)page_address(page);
224 /* copy_page is not usable for copying task structs. */
225 memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
235 * free_pagedir - free pages allocated with alloc_pagedir()
238 void free_pagedir(struct pbe *pblist)
243 pbe = (pblist + PB_PAGE_SKIP)->next;
244 ClearPageNosave(virt_to_page(pblist));
245 ClearPageNosaveFree(virt_to_page(pblist));
246 free_page((unsigned long)pblist);
252 * fill_pb_page - Create a list of PBEs on a given memory page
255 static inline void fill_pb_page(struct pbe *pbpage)
260 pbpage += PB_PAGE_SKIP;
263 while (++p < pbpage);
267 * create_pbe_list - Create a list of PBEs on top of a given chain
268 * of memory pages allocated with alloc_pagedir()
271 static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
273 struct pbe *pbpage, *p;
274 unsigned int num = PBES_PER_PAGE;
276 for_each_pb_page (pbpage, pblist) {
280 fill_pb_page(pbpage);
281 num += PBES_PER_PAGE;
284 for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
291 * On resume it is necessary to trace and eventually free the unsafe
292 * pages that have been allocated, because they are needed for I/O
293 * (on x86-64 we likely will "eat" these pages once again while
294 * creating the temporary page translation tables)
298 struct eaten_page *next;
299 char padding[PAGE_SIZE - sizeof(void *)];
302 static struct eaten_page *eaten_pages = NULL;
304 void release_eaten_pages(void)
306 struct eaten_page *p, *q;
311 /* We don't want swsusp_free() to free this page again */
312 ClearPageNosave(virt_to_page(p));
313 free_page((unsigned long)p);
320 * @safe_needed - on resume, for storing the PBE list and the image,
321 * we can only use memory pages that do not conflict with the pages
322 * which had been used before suspend.
324 * The unsafe pages are marked with the PG_nosave_free flag
326 * Allocated but unusable (ie eaten) memory pages should be marked
327 * so that swsusp_free() can release them
330 static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
336 res = (void *)get_zeroed_page(gfp_mask);
337 if (res && PageNosaveFree(virt_to_page(res))) {
338 /* This is for swsusp_free() */
339 SetPageNosave(virt_to_page(res));
340 ((struct eaten_page *)res)->next = eaten_pages;
343 } while (res && PageNosaveFree(virt_to_page(res)));
345 res = (void *)get_zeroed_page(gfp_mask);
347 SetPageNosave(virt_to_page(res));
348 SetPageNosaveFree(virt_to_page(res));
353 unsigned long get_safe_page(gfp_t gfp_mask)
355 return (unsigned long)alloc_image_page(gfp_mask, 1);
359 * alloc_pagedir - Allocate the page directory.
361 * First, determine exactly how many pages we need and
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
368 * On each page we set up a list of struct_pbe elements.
371 struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed)
374 struct pbe *pblist, *pbe;
379 pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
380 pblist = alloc_image_page(gfp_mask, safe_needed);
381 /* FIXME: rewrite this ugly loop */
382 for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
383 pbe = pbe->next, num += PBES_PER_PAGE) {
385 pbe->next = alloc_image_page(gfp_mask, safe_needed);
387 if (!pbe) { /* get_zeroed_page() failed */
388 free_pagedir(pblist);
391 create_pbe_list(pblist, nr_pages);
396 * Free pages we allocated for suspend. Suspend pages are alocated
397 * before atomic copy, so we need to free them after resume.
400 void swsusp_free(void)
403 unsigned long zone_pfn;
405 for_each_zone(zone) {
406 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
407 if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
409 page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
410 if (PageNosave(page) && PageNosaveFree(page)) {
411 ClearPageNosave(page);
412 ClearPageNosaveFree(page);
413 free_page((long) page_address(page));
421 * enough_free_mem - Make sure we enough free memory to snapshot.
423 * Returns TRUE or FALSE after checking the number of available
427 static int enough_free_mem(unsigned int nr_pages)
433 if (!is_highmem(zone))
434 n += zone->free_pages;
435 pr_debug("swsusp: available memory: %u pages\n", n);
436 return n > (nr_pages + PAGES_FOR_IO +
437 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
440 int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed)
444 for_each_pbe (p, pblist) {
445 p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed);
452 static struct pbe *swsusp_alloc(unsigned int nr_pages)
456 if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) {
457 printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
461 if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) {
462 printk(KERN_ERR "suspend: Allocating image pages failed.\n");
470 asmlinkage int swsusp_save(void)
472 unsigned int nr_pages;
474 pr_debug("swsusp: critical section: \n");
477 nr_pages = count_data_pages();
478 printk("swsusp: Need to copy %u pages\n", nr_pages);
480 pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
482 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
483 PAGES_FOR_IO, nr_free_pages());
485 if (!enough_free_mem(nr_pages)) {
486 printk(KERN_ERR "swsusp: Not enough free memory\n");
490 pagedir_nosave = swsusp_alloc(nr_pages);
494 /* During allocating of suspend pagedir, new cold pages may appear.
498 copy_data_pages(pagedir_nosave);
501 * End of critical section. From now on, we can write to memory,
502 * but we should not touch disk. This specially means we must _not_
503 * touch swap space! Except we must write out our image of course.
506 nr_copy_pages = nr_pages;
508 printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);