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>
40 struct highmem_page
*next
;
43 static struct highmem_page
*highmem_copy
;
45 static int save_highmem_zone(struct zone
*zone
)
47 unsigned long zone_pfn
;
48 mark_free_pages(zone
);
49 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
) {
51 struct highmem_page
*save
;
53 unsigned long pfn
= zone_pfn
+ zone
->zone_start_pfn
;
59 page
= pfn_to_page(pfn
);
61 * This condition results from rvmalloc() sans vmalloc_32()
62 * and architectural memory reservations. This should be
63 * corrected eventually when the cases giving rise to this
64 * are better understood.
66 if (PageReserved(page
)) {
67 printk("highmem reserved page?!\n");
70 BUG_ON(PageNosave(page
));
71 if (PageNosaveFree(page
))
73 save
= kmalloc(sizeof(struct highmem_page
), GFP_ATOMIC
);
76 save
->next
= highmem_copy
;
78 save
->data
= (void *) get_zeroed_page(GFP_ATOMIC
);
83 kaddr
= kmap_atomic(page
, KM_USER0
);
84 memcpy(save
->data
, kaddr
, PAGE_SIZE
);
85 kunmap_atomic(kaddr
, KM_USER0
);
92 static int save_highmem(void)
97 pr_debug("swsusp: Saving Highmem\n");
98 for_each_zone (zone
) {
100 res
= save_highmem_zone(zone
);
107 int restore_highmem(void)
109 printk("swsusp: Restoring Highmem\n");
110 while (highmem_copy
) {
111 struct highmem_page
*save
= highmem_copy
;
113 highmem_copy
= save
->next
;
115 kaddr
= kmap_atomic(save
->page
, KM_USER0
);
116 memcpy(kaddr
, save
->data
, PAGE_SIZE
);
117 kunmap_atomic(kaddr
, KM_USER0
);
118 free_page((long) save
->data
);
124 static int save_highmem(void) { return 0; }
125 int restore_highmem(void) { return 0; }
126 #endif /* CONFIG_HIGHMEM */
129 static int pfn_is_nosave(unsigned long pfn
)
131 unsigned long nosave_begin_pfn
= __pa(&__nosave_begin
) >> PAGE_SHIFT
;
132 unsigned long nosave_end_pfn
= PAGE_ALIGN(__pa(&__nosave_end
)) >> PAGE_SHIFT
;
133 return (pfn
>= nosave_begin_pfn
) && (pfn
< nosave_end_pfn
);
137 * saveable - Determine whether a page should be cloned or not.
140 * We save a page if it's Reserved, and not in the range of pages
141 * statically defined as 'unsaveable', or if it isn't reserved, and
142 * isn't part of a free chunk of pages.
145 static int saveable(struct zone
*zone
, unsigned long *zone_pfn
)
147 unsigned long pfn
= *zone_pfn
+ zone
->zone_start_pfn
;
153 page
= pfn_to_page(pfn
);
154 BUG_ON(PageReserved(page
) && PageNosave(page
));
155 if (PageNosave(page
))
157 if (PageReserved(page
) && pfn_is_nosave(pfn
)) {
158 pr_debug("[nosave pfn 0x%lx]", pfn
);
161 if (PageNosaveFree(page
))
167 static unsigned count_data_pages(void)
170 unsigned long zone_pfn
;
173 for_each_zone (zone
) {
174 if (is_highmem(zone
))
176 mark_free_pages(zone
);
177 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
)
178 n
+= saveable(zone
, &zone_pfn
);
183 static void copy_data_pages(struct pbe
*pblist
)
186 unsigned long zone_pfn
;
190 for_each_zone (zone
) {
191 if (is_highmem(zone
))
193 mark_free_pages(zone
);
194 /* This is necessary for swsusp_free() */
195 for_each_pb_page (p
, pblist
)
196 SetPageNosaveFree(virt_to_page(p
));
197 for_each_pbe (p
, pblist
)
198 SetPageNosaveFree(virt_to_page(p
->address
));
199 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
) {
200 if (saveable(zone
, &zone_pfn
)) {
202 page
= pfn_to_page(zone_pfn
+ zone
->zone_start_pfn
);
204 pbe
->orig_address
= (unsigned long)page_address(page
);
205 /* copy_page is not usable for copying task structs. */
206 memcpy((void *)pbe
->address
, (void *)pbe
->orig_address
, PAGE_SIZE
);
216 * free_pagedir - free pages allocated with alloc_pagedir()
219 static void free_pagedir(struct pbe
*pblist
)
224 pbe
= (pblist
+ PB_PAGE_SKIP
)->next
;
225 ClearPageNosave(virt_to_page(pblist
));
226 ClearPageNosaveFree(virt_to_page(pblist
));
227 free_page((unsigned long)pblist
);
233 * fill_pb_page - Create a list of PBEs on a given memory page
236 static inline void fill_pb_page(struct pbe
*pbpage
)
241 pbpage
+= PB_PAGE_SKIP
;
244 while (++p
< pbpage
);
248 * create_pbe_list - Create a list of PBEs on top of a given chain
249 * of memory pages allocated with alloc_pagedir()
252 void create_pbe_list(struct pbe
*pblist
, unsigned int nr_pages
)
254 struct pbe
*pbpage
, *p
;
255 unsigned int num
= PBES_PER_PAGE
;
257 for_each_pb_page (pbpage
, pblist
) {
261 fill_pb_page(pbpage
);
262 num
+= PBES_PER_PAGE
;
265 for (num
-= PBES_PER_PAGE
- 1, p
= pbpage
; num
< nr_pages
; p
++, num
++)
269 pr_debug("create_pbe_list(): initialized %d PBEs\n", num
);
272 static void *alloc_image_page(void)
274 void *res
= (void *)get_zeroed_page(GFP_ATOMIC
| __GFP_COLD
);
276 SetPageNosave(virt_to_page(res
));
277 SetPageNosaveFree(virt_to_page(res
));
283 * alloc_pagedir - Allocate the page directory.
285 * First, determine exactly how many pages we need and
288 * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
289 * struct pbe elements (pbes) and the last element in the page points
292 * On each page we set up a list of struct_pbe elements.
295 struct pbe
*alloc_pagedir(unsigned int nr_pages
)
298 struct pbe
*pblist
, *pbe
;
303 pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages
);
304 pblist
= alloc_image_page();
305 /* FIXME: rewrite this ugly loop */
306 for (pbe
= pblist
, num
= PBES_PER_PAGE
; pbe
&& num
< nr_pages
;
307 pbe
= pbe
->next
, num
+= PBES_PER_PAGE
) {
309 pbe
->next
= alloc_image_page();
311 if (!pbe
) { /* get_zeroed_page() failed */
312 free_pagedir(pblist
);
319 * Free pages we allocated for suspend. Suspend pages are alocated
320 * before atomic copy, so we need to free them after resume.
323 void swsusp_free(void)
326 unsigned long zone_pfn
;
328 for_each_zone(zone
) {
329 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
)
330 if (pfn_valid(zone_pfn
+ zone
->zone_start_pfn
)) {
332 page
= pfn_to_page(zone_pfn
+ zone
->zone_start_pfn
);
333 if (PageNosave(page
) && PageNosaveFree(page
)) {
334 ClearPageNosave(page
);
335 ClearPageNosaveFree(page
);
336 free_page((long) page_address(page
));
344 * enough_free_mem - Make sure we enough free memory to snapshot.
346 * Returns TRUE or FALSE after checking the number of available
350 static int enough_free_mem(unsigned int nr_pages
)
352 pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
353 return nr_free_pages() > (nr_pages
+ PAGES_FOR_IO
+
354 (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
);
358 static struct pbe
*swsusp_alloc(unsigned int nr_pages
)
360 struct pbe
*pblist
, *p
;
362 if (!(pblist
= alloc_pagedir(nr_pages
))) {
363 printk(KERN_ERR
"suspend: Allocating pagedir failed.\n");
366 create_pbe_list(pblist
, nr_pages
);
368 for_each_pbe (p
, pblist
) {
369 p
->address
= (unsigned long)alloc_image_page();
371 printk(KERN_ERR
"suspend: Allocating image pages failed.\n");
380 asmlinkage
int swsusp_save(void)
382 unsigned int nr_pages
;
384 pr_debug("swsusp: critical section: \n");
385 if (save_highmem()) {
386 printk(KERN_CRIT
"swsusp: Not enough free pages for highmem\n");
392 nr_pages
= count_data_pages();
393 printk("swsusp: Need to copy %u pages\n", nr_pages
);
395 pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
397 (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
,
398 PAGES_FOR_IO
, nr_free_pages());
400 /* This is needed because of the fixed size of swsusp_info */
401 if (MAX_PBES
< (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
)
404 if (!enough_free_mem(nr_pages
)) {
405 printk(KERN_ERR
"swsusp: Not enough free memory\n");
409 if (!enough_swap(nr_pages
)) {
410 printk(KERN_ERR
"swsusp: Not enough free swap\n");
414 pagedir_nosave
= swsusp_alloc(nr_pages
);
418 /* During allocating of suspend pagedir, new cold pages may appear.
422 copy_data_pages(pagedir_nosave
);
425 * End of critical section. From now on, we can write to memory,
426 * but we should not touch disk. This specially means we must _not_
427 * touch swap space! Except we must write out our image of course.
430 nr_copy_pages
= nr_pages
;
432 printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages
);