diff options
Diffstat (limited to 'kernel/power/snapshot.c')
| -rw-r--r-- | kernel/power/snapshot.c | 250 |
1 files changed, 234 insertions, 16 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 48fc7a3..f66e441 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -21,6 +21,7 @@ #include <linux/kernel.h> #include <linux/pm.h> #include <linux/device.h> +#include <linux/init.h> #include <linux/bootmem.h> #include <linux/syscalls.h> #include <linux/console.h> @@ -34,6 +35,10 @@ #include "power.h" +static int swsusp_page_is_free(struct page *); +static void swsusp_set_page_forbidden(struct page *); +static void swsusp_unset_page_forbidden(struct page *); + /* List of PBEs needed for restoring the pages that were allocated before * the suspend and included in the suspend image, but have also been * allocated by the "resume" kernel, so their contents cannot be written @@ -224,11 +229,6 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave) * of type unsigned long each). It also contains the pfns that * correspond to the start and end of the represented memory area and * the number of bit chunks in the block. - * - * NOTE: Memory bitmaps are used for two types of operations only: - * "set a bit" and "find the next bit set". Moreover, the searching - * is always carried out after all of the "set a bit" operations - * on given bitmap. */ #define BM_END_OF_MAP (~0UL) @@ -443,15 +443,13 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) } /** - * memory_bm_set_bit - set the bit in the bitmap @bm that corresponds + * memory_bm_find_bit - find the bit in the bitmap @bm that corresponds * to given pfn. The cur_zone_bm member of @bm and the cur_block member * of @bm->cur_zone_bm are updated. - * - * If the bit cannot be set, the function returns -EINVAL . */ -static int -memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) +static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, + void **addr, unsigned int *bit_nr) { struct zone_bitmap *zone_bm; struct bm_block *bb; @@ -463,8 +461,8 @@ memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) /* We don't assume that the zones are sorted by pfns */ while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { zone_bm = zone_bm->next; - if (unlikely(!zone_bm)) - return -EINVAL; + + BUG_ON(!zone_bm); } bm->cur.zone_bm = zone_bm; } @@ -475,13 +473,40 @@ memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) while (pfn >= bb->end_pfn) { bb = bb->next; - if (unlikely(!bb)) - return -EINVAL; + + BUG_ON(!bb); } zone_bm->cur_block = bb; pfn -= bb->start_pfn; - set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK); - return 0; + *bit_nr = pfn % BM_BITS_PER_CHUNK; + *addr = bb->data + pfn / BM_BITS_PER_CHUNK; +} + +static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) +{ + void *addr; + unsigned int bit; + + memory_bm_find_bit(bm, pfn, &addr, &bit); + set_bit(bit, addr); +} + +static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) +{ + void *addr; + unsigned int bit; + + memory_bm_find_bit(bm, pfn, &addr, &bit); + clear_bit(bit, addr); +} + +static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) +{ + void *addr; + unsigned int bit; + + memory_bm_find_bit(bm, pfn, &addr, &bit); + return test_bit(bit, addr); } /* Two auxiliary functions for memory_bm_next_pfn */ @@ -564,6 +589,199 @@ static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) } /** + * This structure represents a range of page frames the contents of which + * should not be saved during the suspend. + */ + +struct nosave_region { + struct list_head list; + unsigned long start_pfn; + unsigned long end_pfn; +}; + +static LIST_HEAD(nosave_regions); + +/** + * register_nosave_region - register a range of page frames the contents + * of which should not be saved during the suspend (to be used in the early + * initialization code) + */ + +void __init +register_nosave_region(unsigned long start_pfn, unsigned long end_pfn) +{ + struct nosave_region *region; + + if (start_pfn >= end_pfn) + return; + + if (!list_empty(&nosave_regions)) { + /* Try to extend the previous region (they should be sorted) */ + region = list_entry(nosave_regions.prev, + struct nosave_region, list); + if (region->end_pfn == start_pfn) { + region->end_pfn = end_pfn; + goto Report; + } + } + /* This allocation cannot fail */ + region = alloc_bootmem_low(sizeof(struct nosave_region)); + region->start_pfn = start_pfn; + region->end_pfn = end_pfn; + list_add_tail(®ion->list, &nosave_regions); + Report: + printk("swsusp: Registered nosave memory region: %016lx - %016lx\n", + start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT); +} + +/* + * Set bits in this map correspond to the page frames the contents of which + * should not be saved during the suspend. + */ +static struct memory_bitmap *forbidden_pages_map; + +/* Set bits in this map correspond to free page frames. */ +static struct memory_bitmap *free_pages_map; + +/* + * Each page frame allocated for creating the image is marked by setting the + * corresponding bits in forbidden_pages_map and free_pages_map simultaneously + */ + +void swsusp_set_page_free(struct page *page) +{ + if (free_pages_map) + memory_bm_set_bit(free_pages_map, page_to_pfn(page)); +} + +static int swsusp_page_is_free(struct page *page) +{ + return free_pages_map ? + memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0; +} + +void swsusp_unset_page_free(struct page *page) +{ + if (free_pages_map) + memory_bm_clear_bit(free_pages_map, page_to_pfn(page)); +} + +static void swsusp_set_page_forbidden(struct page *page) +{ + if (forbidden_pages_map) + memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page)); +} + +int swsusp_page_is_forbidden(struct page *page) +{ + return forbidden_pages_map ? + memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0; +} + +static void swsusp_unset_page_forbidden(struct page *page) +{ + if (forbidden_pages_map) + memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page)); +} + +/** + * mark_nosave_pages - set bits corresponding to the page frames the + * contents of which should not be saved in a given bitmap. + */ + +static void mark_nosave_pages(struct memory_bitmap *bm) +{ + struct nosave_region *region; + + if (list_empty(&nosave_regions)) + return; + + list_for_each_entry(region, &nosave_regions, list) { + unsigned long pfn; + + printk("swsusp: Marking nosave pages: %016lx - %016lx\n", + region->start_pfn << PAGE_SHIFT, + region->end_pfn << PAGE_SHIFT); + + for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++) + memory_bm_set_bit(bm, pfn); + } +} + +/** + * create_basic_memory_bitmaps - create bitmaps needed for marking page + * frames that should not be saved and free page frames. The pointers + * forbidden_pages_map and free_pages_map are only modified if everything + * goes well, because we don't want the bits to be used before both bitmaps + * are set up. + */ + +int create_basic_memory_bitmaps(void) +{ + struct memory_bitmap *bm1, *bm2; + int error = 0; + + BUG_ON(forbidden_pages_map || free_pages_map); + + bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_ATOMIC); + if (!bm1) + return -ENOMEM; + + error = memory_bm_create(bm1, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free_first_object; + + bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_ATOMIC); + if (!bm2) + goto Free_first_bitmap; + + error = memory_bm_create(bm2, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free_second_object; + + forbidden_pages_map = bm1; + free_pages_map = bm2; + mark_nosave_pages(forbidden_pages_map); + + printk("swsusp: Basic memory bitmaps created\n"); + + return 0; + + Free_second_object: + kfree(bm2); + Free_first_bitmap: + memory_bm_free(bm1, PG_UNSAFE_CLEAR); + Free_first_object: + kfree(bm1); + return -ENOMEM; +} + +/** + * free_basic_memory_bitmaps - free memory bitmaps allocated by + * create_basic_memory_bitmaps(). The auxiliary pointers are necessary + * so that the bitmaps themselves are not referred to while they are being + * freed. + */ + +void free_basic_memory_bitmaps(void) +{ + struct memory_bitmap *bm1, *bm2; + + BUG_ON(!(forbidden_pages_map && free_pages_map)); + + bm1 = forbidden_pages_map; + bm2 = free_pages_map; + forbidden_pages_map = NULL; + free_pages_map = NULL; + memory_bm_free(bm1, PG_UNSAFE_CLEAR); + kfree(bm1); + memory_bm_free(bm2, PG_UNSAFE_CLEAR); + kfree(bm2); + + printk("swsusp: Basic memory bitmaps freed\n"); +} + +/** * snapshot_additional_pages - estimate the number of additional pages * be needed for setting up the suspend image data structures for given * zone (usually the returned value is greater than the exact number) |
