diff options
Diffstat (limited to 'kernel/power/snapshot.c')
| -rw-r--r-- | kernel/power/snapshot.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c new file mode 100644 index 000000000000..4a6dbcefd378 --- /dev/null +++ b/kernel/power/snapshot.c @@ -0,0 +1,453 @@ +/* + * linux/kernel/power/snapshot.c + * + * This file provide system snapshot/restore functionality. + * + * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz> + * + * This file is released under the GPLv2, and is based on swsusp.c. + * + */ + + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/suspend.h> +#include <linux/smp_lock.h> +#include <linux/delay.h> +#include <linux/bitops.h> +#include <linux/spinlock.h> +#include <linux/kernel.h> +#include <linux/pm.h> +#include <linux/device.h> +#include <linux/bootmem.h> +#include <linux/syscalls.h> +#include <linux/console.h> +#include <linux/highmem.h> + +#include <asm/uaccess.h> +#include <asm/mmu_context.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/io.h> + +#include "power.h" + +#ifdef CONFIG_HIGHMEM +struct highmem_page { + char *data; + struct page *page; + struct highmem_page *next; +}; + +static struct highmem_page *highmem_copy; + +static int save_highmem_zone(struct zone *zone) +{ + unsigned long zone_pfn; + mark_free_pages(zone); + for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { + struct page *page; + struct highmem_page *save; + void *kaddr; + unsigned long pfn = zone_pfn + zone->zone_start_pfn; + + if (!(pfn%1000)) + printk("."); + if (!pfn_valid(pfn)) + continue; + page = pfn_to_page(pfn); + /* + * This condition results from rvmalloc() sans vmalloc_32() + * and architectural memory reservations. This should be + * corrected eventually when the cases giving rise to this + * are better understood. + */ + if (PageReserved(page)) { + printk("highmem reserved page?!\n"); + continue; + } + BUG_ON(PageNosave(page)); + if (PageNosaveFree(page)) + continue; + save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC); + if (!save) + return -ENOMEM; + save->next = highmem_copy; + save->page = page; + save->data = (void *) get_zeroed_page(GFP_ATOMIC); + if (!save->data) { + kfree(save); + return -ENOMEM; + } + kaddr = kmap_atomic(page, KM_USER0); + memcpy(save->data, kaddr, PAGE_SIZE); + kunmap_atomic(kaddr, KM_USER0); + highmem_copy = save; + } + return 0; +} + +int save_highmem(void) +{ + struct zone *zone; + int res = 0; + + pr_debug("swsusp: Saving Highmem\n"); + for_each_zone (zone) { + if (is_highmem(zone)) + res = save_highmem_zone(zone); + if (res) + return res; + } + return 0; +} + +int restore_highmem(void) +{ + printk("swsusp: Restoring Highmem\n"); + while (highmem_copy) { + struct highmem_page *save = highmem_copy; + void *kaddr; + highmem_copy = save->next; + + kaddr = kmap_atomic(save->page, KM_USER0); + memcpy(kaddr, save->data, PAGE_SIZE); + kunmap_atomic(kaddr, KM_USER0); + free_page((long) save->data); + kfree(save); + } + return 0; +} +#endif + +static int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; + unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; + return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); +} + +/** + * saveable - Determine whether a page should be cloned or not. + * @pfn: The page + * + * We save a page if it's Reserved, and not in the range of pages + * statically defined as 'unsaveable', or if it isn't reserved, and + * isn't part of a free chunk of pages. + */ + +static int saveable(struct zone *zone, unsigned long *zone_pfn) +{ + unsigned long pfn = *zone_pfn + zone->zone_start_pfn; + struct page *page; + + if (!pfn_valid(pfn)) + return 0; + + page = pfn_to_page(pfn); + BUG_ON(PageReserved(page) && PageNosave(page)); + if (PageNosave(page)) + return 0; + if (PageReserved(page) && pfn_is_nosave(pfn)) { + pr_debug("[nosave pfn 0x%lx]", pfn); + return 0; + } + if (PageNosaveFree(page)) + return 0; + + return 1; +} + +static unsigned count_data_pages(void) +{ + struct zone *zone; + unsigned long zone_pfn; + unsigned int n = 0; + + for_each_zone (zone) { + if (is_highmem(zone)) + continue; + mark_free_pages(zone); + for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) + n += saveable(zone, &zone_pfn); + } + return n; +} + +static void copy_data_pages(struct pbe *pblist) +{ + struct zone *zone; + unsigned long zone_pfn; + struct pbe *pbe, *p; + + pbe = pblist; + for_each_zone (zone) { + if (is_highmem(zone)) + continue; + mark_free_pages(zone); + /* This is necessary for swsusp_free() */ + for_each_pb_page (p, pblist) + SetPageNosaveFree(virt_to_page(p)); + for_each_pbe (p, pblist) + SetPageNosaveFree(virt_to_page(p->address)); + for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { + if (saveable(zone, &zone_pfn)) { + struct page *page; + page = pfn_to_page(zone_pfn + zone->zone_start_pfn); + BUG_ON(!pbe); + pbe->orig_address = (unsigned long)page_address(page); + /* copy_page is not usable for copying task structs. */ + memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE); + pbe = pbe->next; + } + } + } + BUG_ON(pbe); +} + + +/** + * free_pagedir - free pages allocated with alloc_pagedir() + */ + +void free_pagedir(struct pbe *pblist) +{ + struct pbe *pbe; + + while (pblist) { + pbe = (pblist + PB_PAGE_SKIP)->next; + ClearPageNosave(virt_to_page(pblist)); + ClearPageNosaveFree(virt_to_page(pblist)); + free_page((unsigned long)pblist); + pblist = pbe; + } +} + +/** + * fill_pb_page - Create a list of PBEs on a given memory page + */ + +static inline void fill_pb_page(struct pbe *pbpage) +{ + struct pbe *p; + + p = pbpage; + pbpage += PB_PAGE_SKIP; + do + p->next = p + 1; + while (++p < pbpage); +} + +/** + * create_pbe_list - Create a list of PBEs on top of a given chain + * of memory pages allocated with alloc_pagedir() + */ + +void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) +{ + struct pbe *pbpage, *p; + unsigned int num = PBES_PER_PAGE; + + for_each_pb_page (pbpage, pblist) { + if (num >= nr_pages) + break; + + fill_pb_page(pbpage); + num += PBES_PER_PAGE; + } + if (pbpage) { + for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++) + p->next = p + 1; + p->next = NULL; + } + pr_debug("create_pbe_list(): initialized %d PBEs\n", num); +} + +/** + * @safe_needed - on resume, for storing the PBE list and the image, + * we can only use memory pages that do not conflict with the pages + * which had been used before suspend. + * + * The unsafe pages are marked with the PG_nosave_free flag + * + * Allocated but unusable (ie eaten) memory pages should be marked + * so that swsusp_free() can release them + */ + +static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed) +{ + void *res; + + if (safe_needed) + do { + res = (void *)get_zeroed_page(gfp_mask); + if (res && PageNosaveFree(virt_to_page(res))) + /* This is for swsusp_free() */ + SetPageNosave(virt_to_page(res)); + } while (res && PageNosaveFree(virt_to_page(res))); + else + res = (void *)get_zeroed_page(gfp_mask); + if (res) { + SetPageNosave(virt_to_page(res)); + SetPageNosaveFree(virt_to_page(res)); + } + return res; +} + +unsigned long get_safe_page(gfp_t gfp_mask) +{ + return (unsigned long)alloc_image_page(gfp_mask, 1); +} + +/** + * alloc_pagedir - Allocate the page directory. + * + * First, determine exactly how many pages we need and + * allocate them. + * + * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE + * struct pbe elements (pbes) and the last element in the page points + * to the next page. + * + * On each page we set up a list of struct_pbe elements. + */ + +struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed) +{ + unsigned int num; + struct pbe *pblist, *pbe; + + if (!nr_pages) + return NULL; + + pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages); + pblist = alloc_image_page(gfp_mask, safe_needed); + /* FIXME: rewrite this ugly loop */ + for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages; + pbe = pbe->next, num += PBES_PER_PAGE) { + pbe += PB_PAGE_SKIP; + pbe->next = alloc_image_page(gfp_mask, safe_needed); + } + if (!pbe) { /* get_zeroed_page() failed */ + free_pagedir(pblist); + pblist = NULL; + } + return pblist; +} + +/** + * Free pages we allocated for suspend. Suspend pages are alocated + * before atomic copy, so we need to free them after resume. + */ + +void swsusp_free(void) +{ + struct zone *zone; + unsigned long zone_pfn; + + for_each_zone(zone) { + for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) + if (pfn_valid(zone_pfn + zone->zone_start_pfn)) { + struct page *page; + page = pfn_to_page(zone_pfn + zone->zone_start_pfn); + if (PageNosave(page) && PageNosaveFree(page)) { + ClearPageNosave(page); + ClearPageNosaveFree(page); + free_page((long) page_address(page)); + } + } + } +} + + +/** + * enough_free_mem - Make sure we enough free memory to snapshot. + * + * Returns TRUE or FALSE after checking the number of available + * free pages. + */ + +static int enough_free_mem(unsigned int nr_pages) +{ + pr_debug("swsusp: available memory: %u pages\n", nr_free_pages()); + return nr_free_pages() > (nr_pages + PAGES_FOR_IO + + (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); +} + +int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) +{ + struct pbe *p; + + for_each_pbe (p, pblist) { + p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); + if (!p->address) + return -ENOMEM; + } + return 0; +} + +static struct pbe *swsusp_alloc(unsigned int nr_pages) +{ + struct pbe *pblist; + + if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) { + printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); + return NULL; + } + create_pbe_list(pblist, nr_pages); + + if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) { + printk(KERN_ERR "suspend: Allocating image pages failed.\n"); + swsusp_free(); + return NULL; + } + + return pblist; +} + +asmlinkage int swsusp_save(void) +{ + unsigned int nr_pages; + + pr_debug("swsusp: critical section: \n"); + + drain_local_pages(); + nr_pages = count_data_pages(); + printk("swsusp: Need to copy %u pages\n", nr_pages); + + pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", + nr_pages, + (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, + PAGES_FOR_IO, nr_free_pages()); + + /* This is needed because of the fixed size of swsusp_info */ + if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE) + return -ENOSPC; + + if (!enough_free_mem(nr_pages)) { + printk(KERN_ERR "swsusp: Not enough free memory\n"); + return -ENOMEM; + } + + pagedir_nosave = swsusp_alloc(nr_pages); + if (!pagedir_nosave) + return -ENOMEM; + + /* During allocating of suspend pagedir, new cold pages may appear. + * Kill them. + */ + drain_local_pages(); + copy_data_pages(pagedir_nosave); + + /* + * End of critical section. From now on, we can write to memory, + * but we should not touch disk. This specially means we must _not_ + * touch swap space! Except we must write out our image of course. + */ + + nr_copy_pages = nr_pages; + + printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); + return 0; +} |