1d276b3ae15292df2e92c64de9069c8a13975b14
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/version.h>
14 #include <linux/module.h>
16 #include <linux/suspend.h>
17 #include <linux/smp_lock.h>
18 #include <linux/delay.h>
19 #include <linux/bitops.h>
20 #include <linux/spinlock.h>
21 #include <linux/kernel.h>
23 #include <linux/device.h>
24 #include <linux/bootmem.h>
25 #include <linux/syscalls.h>
26 #include <linux/console.h>
27 #include <linux/highmem.h>
29 #include <asm/uaccess.h>
30 #include <asm/mmu_context.h>
31 #include <asm/pgtable.h>
32 #include <asm/tlbflush.h>
37 /* List of PBEs used for creating and restoring the suspend image */
38 struct pbe
*restore_pblist
;
40 static unsigned int nr_copy_pages
;
41 static unsigned int nr_meta_pages
;
42 static unsigned long *buffer
;
45 unsigned int count_highmem_pages(void)
48 unsigned long zone_pfn
;
52 if (is_highmem(zone
)) {
53 mark_free_pages(zone
);
54 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; zone_pfn
++) {
56 unsigned long pfn
= zone_pfn
+ zone
->zone_start_pfn
;
59 page
= pfn_to_page(pfn
);
60 if (PageReserved(page
))
62 if (PageNosaveFree(page
))
73 struct highmem_page
*next
;
76 static struct highmem_page
*highmem_copy
;
78 static int save_highmem_zone(struct zone
*zone
)
80 unsigned long zone_pfn
;
81 mark_free_pages(zone
);
82 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
) {
84 struct highmem_page
*save
;
86 unsigned long pfn
= zone_pfn
+ zone
->zone_start_pfn
;
92 page
= pfn_to_page(pfn
);
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.
99 if (PageReserved(page
))
101 BUG_ON(PageNosave(page
));
102 if (PageNosaveFree(page
))
104 save
= kmalloc(sizeof(struct highmem_page
), GFP_ATOMIC
);
107 save
->next
= highmem_copy
;
109 save
->data
= (void *) get_zeroed_page(GFP_ATOMIC
);
114 kaddr
= kmap_atomic(page
, KM_USER0
);
115 memcpy(save
->data
, kaddr
, PAGE_SIZE
);
116 kunmap_atomic(kaddr
, KM_USER0
);
122 int save_highmem(void)
127 pr_debug("swsusp: Saving Highmem");
129 for_each_zone (zone
) {
130 if (is_highmem(zone
))
131 res
= save_highmem_zone(zone
);
139 int restore_highmem(void)
141 printk("swsusp: Restoring Highmem\n");
142 while (highmem_copy
) {
143 struct highmem_page
*save
= highmem_copy
;
145 highmem_copy
= save
->next
;
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
);
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;}
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.
166 * The unsafe pages are marked with the PG_nosave_free flag
167 * and we count them using unsafe_pages
170 static unsigned int unsafe_pages
;
172 static void *alloc_image_page(gfp_t gfp_mask
, int safe_needed
)
176 res
= (void *)get_zeroed_page(gfp_mask
);
178 while (res
&& PageNosaveFree(virt_to_page(res
))) {
179 /* The page is unsafe, mark it for swsusp_free() */
180 SetPageNosave(virt_to_page(res
));
182 res
= (void *)get_zeroed_page(gfp_mask
);
185 SetPageNosave(virt_to_page(res
));
186 SetPageNosaveFree(virt_to_page(res
));
191 unsigned long get_safe_page(gfp_t gfp_mask
)
193 return (unsigned long)alloc_image_page(gfp_mask
, 1);
197 * free_image_page - free page represented by @addr, allocated with
198 * alloc_image_page (page flags set by it must be cleared)
201 static inline void free_image_page(void *addr
, int clear_nosave_free
)
203 ClearPageNosave(virt_to_page(addr
));
204 if (clear_nosave_free
)
205 ClearPageNosaveFree(virt_to_page(addr
));
206 free_page((unsigned long)addr
);
210 * pfn_is_nosave - check if given pfn is in the 'nosave' section
213 static inline int pfn_is_nosave(unsigned long pfn
)
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
);
221 * saveable - Determine whether a page should be cloned or not.
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.
229 static struct page
*saveable_page(unsigned long pfn
)
236 page
= pfn_to_page(pfn
);
238 if (PageNosave(page
))
240 if (PageReserved(page
) && pfn_is_nosave(pfn
))
242 if (PageNosaveFree(page
))
248 unsigned int count_data_pages(void)
251 unsigned long pfn
, max_zone_pfn
;
254 for_each_zone (zone
) {
255 if (is_highmem(zone
))
257 mark_free_pages(zone
);
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
);
265 static inline void copy_data_page(long *dst
, long *src
)
269 /* copy_page and memcpy are not usable for copying task structs. */
270 for (n
= PAGE_SIZE
/ sizeof(long); n
; n
--)
274 static void copy_data_pages(struct pbe
*pblist
)
277 unsigned long pfn
, max_zone_pfn
;
281 for_each_zone (zone
) {
282 if (is_highmem(zone
))
284 mark_free_pages(zone
);
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
);
290 void *ptr
= page_address(page
);
293 copy_data_page((void *)pbe
->address
, ptr
);
294 pbe
->orig_address
= (unsigned long)ptr
;
303 * free_pagedir - free pages allocated with alloc_pagedir()
306 static void free_pagedir(struct pbe
*pblist
, int clear_nosave_free
)
311 pbe
= (pblist
+ PB_PAGE_SKIP
)->next
;
312 free_image_page(pblist
, clear_nosave_free
);
318 * fill_pb_page - Create a list of PBEs on a given memory page
321 static inline void fill_pb_page(struct pbe
*pbpage
, unsigned int n
)
329 while (++p
< pbpage
);
333 * create_pbe_list - Create a list of PBEs on top of a given chain
334 * of memory pages allocated with alloc_pagedir()
336 * This function assumes that pages allocated by alloc_image_page() will
340 static inline void create_pbe_list(struct pbe
*pblist
, unsigned int nr_pages
)
343 unsigned int num
= PBES_PER_PAGE
;
345 for_each_pb_page (pbpage
, pblist
) {
349 fill_pb_page(pbpage
, PBES_PER_PAGE
);
350 num
+= PBES_PER_PAGE
;
353 num
-= PBES_PER_PAGE
;
354 fill_pb_page(pbpage
, nr_pages
- num
);
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 static struct pbe
*alloc_pagedir(unsigned int nr_pages
, gfp_t gfp_mask
,
375 struct pbe
*pblist
, *pbe
;
380 pblist
= alloc_image_page(gfp_mask
, safe_needed
);
382 for (num
= PBES_PER_PAGE
; num
< nr_pages
; num
+= PBES_PER_PAGE
) {
384 free_pagedir(pblist
, 1);
388 pbe
->next
= alloc_image_page(gfp_mask
, safe_needed
);
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 pfn
, max_zone_pfn
;
405 for_each_zone(zone
) {
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
);
411 if (PageNosave(page
) && PageNosaveFree(page
)) {
412 ClearPageNosave(page
);
413 ClearPageNosaveFree(page
);
414 free_page((long) page_address(page
));
420 restore_pblist
= NULL
;
426 * enough_free_mem - Make sure we enough free memory to snapshot.
428 * Returns TRUE or FALSE after checking the number of available
432 static int enough_free_mem(unsigned int nr_pages
)
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
+
442 (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
);
445 static int alloc_data_pages(struct pbe
*pblist
, gfp_t gfp_mask
, int safe_needed
)
449 for_each_pbe (p
, pblist
) {
450 p
->address
= (unsigned long)alloc_image_page(gfp_mask
, safe_needed
);
457 static struct pbe
*swsusp_alloc(unsigned int nr_pages
)
461 if (!(pblist
= alloc_pagedir(nr_pages
, GFP_ATOMIC
| __GFP_COLD
, 0))) {
462 printk(KERN_ERR
"suspend: Allocating pagedir failed.\n");
466 if (alloc_data_pages(pblist
, GFP_ATOMIC
| __GFP_COLD
, 0)) {
467 printk(KERN_ERR
"suspend: Allocating image pages failed.\n");
475 asmlinkage
int swsusp_save(void)
477 unsigned int nr_pages
;
479 pr_debug("swsusp: critical section: \n");
482 nr_pages
= count_data_pages();
483 printk("swsusp: Need to copy %u pages\n", nr_pages
);
485 pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
487 (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
,
488 PAGES_FOR_IO
, nr_free_pages());
490 if (!enough_free_mem(nr_pages
)) {
491 printk(KERN_ERR
"swsusp: Not enough free memory\n");
495 restore_pblist
= swsusp_alloc(nr_pages
);
499 /* During allocating of suspend pagedir, new cold pages may appear.
503 copy_data_pages(restore_pblist
);
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.
511 nr_copy_pages
= nr_pages
;
512 nr_meta_pages
= (nr_pages
* sizeof(long) + PAGE_SIZE
- 1) >> PAGE_SHIFT
;
514 printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages
);
518 static void init_header(struct swsusp_info
*info
)
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;
527 info
->size
= info
->pages
;
528 info
->size
<<= PAGE_SHIFT
;
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)
536 static inline struct pbe
*pack_orig_addresses(unsigned long *buf
, struct pbe
*pbe
)
540 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long) && pbe
; j
++) {
541 buf
[j
] = pbe
->orig_address
;
545 for (; j
< PAGE_SIZE
/ sizeof(long); j
++)
551 * snapshot_read_next - used for reading the system memory snapshot.
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.
557 * The @count parameter should contain the number of bytes the caller
558 * wants to read from the snapshot. It must not be zero.
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.
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
572 int snapshot_read_next(struct snapshot_handle
*handle
, size_t count
)
574 if (handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
577 /* This makes the buffer be freed by swsusp_free() */
578 buffer
= alloc_image_page(GFP_ATOMIC
, 0);
582 if (!handle
->offset
) {
583 init_header((struct swsusp_info
*)buffer
);
584 handle
->buffer
= buffer
;
585 handle
->pbe
= restore_pblist
;
587 if (handle
->prev
< handle
->cur
) {
588 if (handle
->cur
<= nr_meta_pages
) {
589 handle
->pbe
= pack_orig_addresses(buffer
, handle
->pbe
);
591 handle
->pbe
= restore_pblist
;
593 handle
->buffer
= (void *)handle
->pbe
->address
;
594 handle
->pbe
= handle
->pbe
->next
;
596 handle
->prev
= handle
->cur
;
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;
604 handle
->cur_offset
+= count
;
606 handle
->offset
+= count
;
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
616 static int mark_unsafe_pages(struct pbe
*pblist
)
619 unsigned long pfn
, max_zone_pfn
;
622 if (!pblist
) /* a sanity check */
625 /* Clear page flags */
626 for_each_zone (zone
) {
627 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
628 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
630 ClearPageNosaveFree(pfn_to_page(pfn
));
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
));
646 static void copy_page_backup_list(struct pbe
*dst
, struct pbe
*src
)
648 /* We assume both lists contain the same number of elements */
650 dst
->orig_address
= src
->orig_address
;
656 static int check_header(struct swsusp_info
*info
)
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
))
670 if (strcmp(info
->uts
.machine
,system_utsname
.machine
))
673 printk(KERN_ERR
"swsusp: Resume mismatch: %s\n", reason
);
680 * load header - check the image header and copy data from it
683 static int load_header(struct snapshot_handle
*handle
,
684 struct swsusp_info
*info
)
689 error
= check_header(info
);
691 pblist
= alloc_pagedir(info
->image_pages
, GFP_ATOMIC
, 0);
694 restore_pblist
= pblist
;
695 handle
->pbe
= pblist
;
696 nr_copy_pages
= info
->image_pages
;
697 nr_meta_pages
= info
->pages
- info
->image_pages
- 1;
703 * unpack_orig_addresses - copy the elements of @buf[] (1 page) to
704 * the PBEs in the list starting at @pbe
707 static inline struct pbe
*unpack_orig_addresses(unsigned long *buf
,
712 for (j
= 0; j
< PAGE_SIZE
/ sizeof(long) && pbe
; j
++) {
713 pbe
->orig_address
= buf
[j
];
720 * prepare_image - use metadata contained in the PBE list
721 * pointed to by restore_pblist to mark the pages that will
722 * be overwritten in the process of restoring the system
723 * memory state from the image ("unsafe" pages) and allocate
724 * memory for the image
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
734 struct safe_page
*next
;
735 char padding
[PAGE_SIZE
- sizeof(void *)];
738 static struct safe_page
*safe_pages
;
740 static int prepare_image(struct snapshot_handle
*handle
)
743 unsigned int nr_pages
= nr_copy_pages
;
744 struct pbe
*p
, *pblist
= NULL
;
747 error
= mark_unsafe_pages(p
);
749 pblist
= alloc_pagedir(nr_pages
, GFP_ATOMIC
, 1);
751 copy_page_backup_list(pblist
, p
);
757 if (!error
&& nr_pages
> unsafe_pages
) {
758 nr_pages
-= unsafe_pages
;
760 struct safe_page
*ptr
;
762 ptr
= (struct safe_page
*)get_zeroed_page(GFP_ATOMIC
);
767 if (!PageNosaveFree(virt_to_page(ptr
))) {
768 /* The page is "safe", add it to the list */
769 ptr
->next
= safe_pages
;
772 /* Mark the page as allocated */
773 SetPageNosave(virt_to_page(ptr
));
774 SetPageNosaveFree(virt_to_page(ptr
));
778 restore_pblist
= pblist
;
786 static void *get_buffer(struct snapshot_handle
*handle
)
788 struct pbe
*pbe
= handle
->pbe
, *last
= handle
->last_pbe
;
789 struct page
*page
= virt_to_page(pbe
->orig_address
);
791 if (PageNosave(page
) && PageNosaveFree(page
)) {
793 * We have allocated the "original" page frame and we can
794 * use it directly to store the read page
797 if (last
&& last
->next
)
799 return (void *)pbe
->orig_address
;
802 * The "original" page frame has not been allocated and we have to
803 * use a "safe" page frame to store the read page
805 pbe
->address
= (unsigned long)safe_pages
;
806 safe_pages
= safe_pages
->next
;
809 handle
->last_pbe
= pbe
;
810 return (void *)pbe
->address
;
814 * snapshot_write_next - used for writing the system memory snapshot.
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.
820 * The @count parameter should contain the number of bytes the caller
821 * wants to write to the image. It must not be zero.
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.
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
835 int snapshot_write_next(struct snapshot_handle
*handle
, size_t count
)
839 if (handle
->prev
&& handle
->cur
> nr_meta_pages
+ nr_copy_pages
)
842 /* This makes the buffer be freed by swsusp_free() */
843 buffer
= alloc_image_page(GFP_ATOMIC
, 0);
848 handle
->buffer
= buffer
;
849 handle
->sync_read
= 1;
850 if (handle
->prev
< handle
->cur
) {
852 error
= load_header(handle
,
853 (struct swsusp_info
*)buffer
);
856 } else if (handle
->prev
<= nr_meta_pages
) {
857 handle
->pbe
= unpack_orig_addresses(buffer
,
860 error
= prepare_image(handle
);
863 handle
->pbe
= restore_pblist
;
864 handle
->last_pbe
= NULL
;
865 handle
->buffer
= get_buffer(handle
);
866 handle
->sync_read
= 0;
869 handle
->pbe
= handle
->pbe
->next
;
870 handle
->buffer
= get_buffer(handle
);
871 handle
->sync_read
= 0;
873 handle
->prev
= handle
->cur
;
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;
881 handle
->cur_offset
+= count
;
883 handle
->offset
+= count
;
887 int snapshot_image_loaded(struct snapshot_handle
*handle
)
889 return !(!handle
->pbe
|| handle
->pbe
->next
|| !nr_copy_pages
||
890 handle
->cur
<= nr_meta_pages
+ nr_copy_pages
);
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