diff options
Diffstat (limited to 'kernel/power/swsusp.c')
| -rw-r--r-- | kernel/power/swsusp.c | 568 |
1 files changed, 6 insertions, 562 deletions
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index 457084f5001..c4016cbbd3e 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -31,41 +31,24 @@ * Fixed runaway init * * Rafael J. Wysocki <rjw@sisk.pl> - * Added the swap map data structure and reworked the handling of swap + * Reworked the freeing of memory and the handling of swap * * More state savers are welcome. Especially for the scsi layer... * * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt */ -#include <linux/module.h> #include <linux/mm.h> #include <linux/suspend.h> -#include <linux/smp_lock.h> -#include <linux/file.h> -#include <linux/utsname.h> -#include <linux/version.h> -#include <linux/delay.h> -#include <linux/bitops.h> #include <linux/spinlock.h> -#include <linux/genhd.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/swap.h> #include <linux/pm.h> -#include <linux/device.h> -#include <linux/buffer_head.h> #include <linux/swapops.h> #include <linux/bootmem.h> #include <linux/syscalls.h> #include <linux/highmem.h> -#include <linux/bio.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" @@ -89,91 +72,15 @@ static int restore_highmem(void) { return 0; } static unsigned int count_highmem_pages(void) { return 0; } #endif -extern char resume_file[]; - -#define SWSUSP_SIG "S1SUSPEND" - -static struct swsusp_header { - char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)]; - swp_entry_t image; - char orig_sig[10]; - char sig[10]; -} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header; - -/* - * Saving part... - */ - -static unsigned short root_swap = 0xffff; - -static int mark_swapfiles(swp_entry_t start) -{ - int error; - - rw_swap_page_sync(READ, - swp_entry(root_swap, 0), - virt_to_page((unsigned long)&swsusp_header)); - if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) || - !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) { - memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10); - memcpy(swsusp_header.sig,SWSUSP_SIG, 10); - swsusp_header.image = start; - error = rw_swap_page_sync(WRITE, - swp_entry(root_swap, 0), - virt_to_page((unsigned long) - &swsusp_header)); - } else { - pr_debug("swsusp: Partition is not swap space.\n"); - error = -ENODEV; - } - return error; -} - -/** - * swsusp_swap_check - check if the resume device is a swap device - * and get its index (if so) - */ - -static int swsusp_swap_check(void) /* This is called before saving image */ -{ - int res = swap_type_of(swsusp_resume_device); - - if (res >= 0) { - root_swap = res; - return 0; - } - return res; -} - -/** - * The bitmap is used for tracing allocated swap pages - * - * The entire bitmap consists of a number of bitmap_page - * structures linked with the help of the .next member. - * Thus each page can be allocated individually, so we only - * need to make 0-order memory allocations to create - * the bitmap. - */ - -#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *)) -#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long)) -#define BITS_PER_CHUNK (sizeof(long) * 8) -#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK) - -struct bitmap_page { - unsigned long chunks[BITMAP_PAGE_CHUNKS]; - struct bitmap_page *next; -}; - /** * The following functions are used for tracing the allocated * swap pages, so that they can be freed in case of an error. * * The functions operate on a linked bitmap structure defined - * above + * in power.h */ -static void free_bitmap(struct bitmap_page *bitmap) +void free_bitmap(struct bitmap_page *bitmap) { struct bitmap_page *bp; @@ -184,7 +91,7 @@ static void free_bitmap(struct bitmap_page *bitmap) } } -static struct bitmap_page *alloc_bitmap(unsigned int nr_bits) +struct bitmap_page *alloc_bitmap(unsigned int nr_bits) { struct bitmap_page *bitmap, *bp; unsigned int n; @@ -227,7 +134,7 @@ static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit) return 0; } -static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap) +unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap) { unsigned long offset; @@ -241,7 +148,7 @@ static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap) return offset; } -static void free_all_swap_pages(int swap, struct bitmap_page *bitmap) +void free_all_swap_pages(int swap, struct bitmap_page *bitmap) { unsigned int bit, n; unsigned long test; @@ -259,220 +166,6 @@ static void free_all_swap_pages(int swap, struct bitmap_page *bitmap) } /** - * write_page - Write one page to given swap location. - * @buf: Address we're writing. - * @offset: Offset of the swap page we're writing to. - */ - -static int write_page(void *buf, unsigned long offset) -{ - swp_entry_t entry; - int error = -ENOSPC; - - if (offset) { - entry = swp_entry(root_swap, offset); - error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf)); - } - return error; -} - -/* - * The swap map is a data structure used for keeping track of each page - * written to a swap partition. It consists of many swap_map_page - * structures that contain each an array of MAP_PAGE_SIZE swap entries. - * These structures are stored on the swap and linked together with the - * help of the .next_swap member. - * - * The swap map is created during suspend. The swap map pages are - * allocated and populated one at a time, so we only need one memory - * page to set up the entire structure. - * - * During resume we also only need to use one swap_map_page structure - * at a time. - */ - -#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1) - -struct swap_map_page { - unsigned long entries[MAP_PAGE_ENTRIES]; - unsigned long next_swap; -}; - -/** - * The swap_map_handle structure is used for handling swap in - * a file-alike way - */ - -struct swap_map_handle { - struct swap_map_page *cur; - unsigned long cur_swap; - struct bitmap_page *bitmap; - unsigned int k; -}; - -static void release_swap_writer(struct swap_map_handle *handle) -{ - if (handle->cur) - free_page((unsigned long)handle->cur); - handle->cur = NULL; - if (handle->bitmap) - free_bitmap(handle->bitmap); - handle->bitmap = NULL; -} - -static int get_swap_writer(struct swap_map_handle *handle) -{ - handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); - if (!handle->cur) - return -ENOMEM; - handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0)); - if (!handle->bitmap) { - release_swap_writer(handle); - return -ENOMEM; - } - handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap); - if (!handle->cur_swap) { - release_swap_writer(handle); - return -ENOSPC; - } - handle->k = 0; - return 0; -} - -static int swap_write_page(struct swap_map_handle *handle, void *buf) -{ - int error; - unsigned long offset; - - if (!handle->cur) - return -EINVAL; - offset = alloc_swap_page(root_swap, handle->bitmap); - error = write_page(buf, offset); - if (error) - return error; - handle->cur->entries[handle->k++] = offset; - if (handle->k >= MAP_PAGE_ENTRIES) { - offset = alloc_swap_page(root_swap, handle->bitmap); - if (!offset) - return -ENOSPC; - handle->cur->next_swap = offset; - error = write_page(handle->cur, handle->cur_swap); - if (error) - return error; - memset(handle->cur, 0, PAGE_SIZE); - handle->cur_swap = offset; - handle->k = 0; - } - return 0; -} - -static int flush_swap_writer(struct swap_map_handle *handle) -{ - if (handle->cur && handle->cur_swap) - return write_page(handle->cur, handle->cur_swap); - else - return -EINVAL; -} - -/** - * save_image - save the suspend image data - */ - -static int save_image(struct swap_map_handle *handle, - struct snapshot_handle *snapshot, - unsigned int nr_pages) -{ - unsigned int m; - int ret; - int error = 0; - - printk("Saving image data pages (%u pages) ... ", nr_pages); - m = nr_pages / 100; - if (!m) - m = 1; - nr_pages = 0; - do { - ret = snapshot_read_next(snapshot, PAGE_SIZE); - if (ret > 0) { - error = swap_write_page(handle, data_of(*snapshot)); - if (error) - break; - if (!(nr_pages % m)) - printk("\b\b\b\b%3d%%", nr_pages / m); - nr_pages++; - } - } while (ret > 0); - if (!error) - printk("\b\b\b\bdone\n"); - return error; -} - -/** - * enough_swap - Make sure we have enough swap to save the image. - * - * Returns TRUE or FALSE after checking the total amount of swap - * space avaiable from the resume partition. - */ - -static int enough_swap(unsigned int nr_pages) -{ - unsigned int free_swap = count_swap_pages(root_swap, 1); - - pr_debug("swsusp: free swap pages: %u\n", free_swap); - return free_swap > (nr_pages + PAGES_FOR_IO + - (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); -} - -/** - * swsusp_write - Write entire image and metadata. - * - * It is important _NOT_ to umount filesystems at this point. We want - * them synced (in case something goes wrong) but we DO not want to mark - * filesystem clean: it is not. (And it does not matter, if we resume - * correctly, we'll mark system clean, anyway.) - */ - -int swsusp_write(void) -{ - struct swap_map_handle handle; - struct snapshot_handle snapshot; - struct swsusp_info *header; - unsigned long start; - int error; - - if ((error = swsusp_swap_check())) { - printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n"); - return error; - } - memset(&snapshot, 0, sizeof(struct snapshot_handle)); - error = snapshot_read_next(&snapshot, PAGE_SIZE); - if (error < PAGE_SIZE) - return error < 0 ? error : -EFAULT; - header = (struct swsusp_info *)data_of(snapshot); - if (!enough_swap(header->pages)) { - printk(KERN_ERR "swsusp: Not enough free swap\n"); - return -ENOSPC; - } - error = get_swap_writer(&handle); - if (!error) { - start = handle.cur_swap; - error = swap_write_page(&handle, header); - } - if (!error) - error = save_image(&handle, &snapshot, header->pages - 1); - if (!error) { - flush_swap_writer(&handle); - printk("S"); - error = mark_swapfiles(swp_entry(root_swap, start)); - printk("|\n"); - } - if (error) - free_all_swap_pages(root_swap, handle.bitmap); - release_swap_writer(&handle); - return error; -} - -/** * swsusp_shrink_memory - Try to free as much memory as needed * * ... but do not OOM-kill anyone @@ -578,252 +271,3 @@ int swsusp_resume(void) local_irq_enable(); return error; } - -/* - * Using bio to read from swap. - * This code requires a bit more work than just using buffer heads - * but, it is the recommended way for 2.5/2.6. - * The following are to signal the beginning and end of I/O. Bios - * finish asynchronously, while we want them to happen synchronously. - * A simple atomic_t, and a wait loop take care of this problem. - */ - -static atomic_t io_done = ATOMIC_INIT(0); - -static int end_io(struct bio *bio, unsigned int num, int err) -{ - if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) - panic("I/O error reading memory image"); - atomic_set(&io_done, 0); - return 0; -} - -static struct block_device *resume_bdev; - -/** - * submit - submit BIO request. - * @rw: READ or WRITE. - * @off physical offset of page. - * @page: page we're reading or writing. - * - * Straight from the textbook - allocate and initialize the bio. - * If we're writing, make sure the page is marked as dirty. - * Then submit it and wait. - */ - -static int submit(int rw, pgoff_t page_off, void *page) -{ - int error = 0; - struct bio *bio; - - bio = bio_alloc(GFP_ATOMIC, 1); - if (!bio) - return -ENOMEM; - bio->bi_sector = page_off * (PAGE_SIZE >> 9); - bio->bi_bdev = resume_bdev; - bio->bi_end_io = end_io; - - if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) { - printk("swsusp: ERROR: adding page to bio at %ld\n",page_off); - error = -EFAULT; - goto Done; - } - - - atomic_set(&io_done, 1); - submit_bio(rw | (1 << BIO_RW_SYNC), bio); - while (atomic_read(&io_done)) - yield(); - if (rw == READ) - bio_set_pages_dirty(bio); - Done: - bio_put(bio); - return error; -} - -static int bio_read_page(pgoff_t page_off, void *page) -{ - return submit(READ, page_off, page); -} - -static int bio_write_page(pgoff_t page_off, void *page) -{ - return submit(WRITE, page_off, page); -} - -/** - * The following functions allow us to read data using a swap map - * in a file-alike way - */ - -static void release_swap_reader(struct swap_map_handle *handle) -{ - if (handle->cur) - free_page((unsigned long)handle->cur); - handle->cur = NULL; -} - -static int get_swap_reader(struct swap_map_handle *handle, - swp_entry_t start) -{ - int error; - - if (!swp_offset(start)) - return -EINVAL; - handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC); - if (!handle->cur) - return -ENOMEM; - error = bio_read_page(swp_offset(start), handle->cur); - if (error) { - release_swap_reader(handle); - return error; - } - handle->k = 0; - return 0; -} - -static int swap_read_page(struct swap_map_handle *handle, void *buf) -{ - unsigned long offset; - int error; - - if (!handle->cur) - return -EINVAL; - offset = handle->cur->entries[handle->k]; - if (!offset) - return -EFAULT; - error = bio_read_page(offset, buf); - if (error) - return error; - if (++handle->k >= MAP_PAGE_ENTRIES) { - handle->k = 0; - offset = handle->cur->next_swap; - if (!offset) - release_swap_reader(handle); - else - error = bio_read_page(offset, handle->cur); - } - return error; -} - -/** - * load_image - load the image using the swap map handle - * @handle and the snapshot handle @snapshot - * (assume there are @nr_pages pages to load) - */ - -static int load_image(struct swap_map_handle *handle, - struct snapshot_handle *snapshot, - unsigned int nr_pages) -{ - unsigned int m; - int ret; - int error = 0; - - printk("Loading image data pages (%u pages) ... ", nr_pages); - m = nr_pages / 100; - if (!m) - m = 1; - nr_pages = 0; - do { - ret = snapshot_write_next(snapshot, PAGE_SIZE); - if (ret > 0) { - error = swap_read_page(handle, data_of(*snapshot)); - if (error) - break; - if (!(nr_pages % m)) - printk("\b\b\b\b%3d%%", nr_pages / m); - nr_pages++; - } - } while (ret > 0); - if (!error) - printk("\b\b\b\bdone\n"); - if (!snapshot_image_loaded(snapshot)) - error = -ENODATA; - return error; -} - -int swsusp_read(void) -{ - int error; - struct swap_map_handle handle; - struct snapshot_handle snapshot; - struct swsusp_info *header; - unsigned int nr_pages; - - if (IS_ERR(resume_bdev)) { - pr_debug("swsusp: block device not initialised\n"); - return PTR_ERR(resume_bdev); - } - - memset(&snapshot, 0, sizeof(struct snapshot_handle)); - error = snapshot_write_next(&snapshot, PAGE_SIZE); - if (error < PAGE_SIZE) - return error < 0 ? error : -EFAULT; - header = (struct swsusp_info *)data_of(snapshot); - error = get_swap_reader(&handle, swsusp_header.image); - if (!error) - error = swap_read_page(&handle, header); - if (!error) { - nr_pages = header->image_pages; - error = load_image(&handle, &snapshot, nr_pages); - } - release_swap_reader(&handle); - - blkdev_put(resume_bdev); - - if (!error) - pr_debug("swsusp: Reading resume file was successful\n"); - else - pr_debug("swsusp: Error %d resuming\n", error); - return error; -} - -/** - * swsusp_check - Check for swsusp signature in the resume device - */ - -int swsusp_check(void) -{ - int error; - - resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); - if (!IS_ERR(resume_bdev)) { - set_blocksize(resume_bdev, PAGE_SIZE); - memset(&swsusp_header, 0, sizeof(swsusp_header)); - if ((error = bio_read_page(0, &swsusp_header))) - return error; - if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) { - memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10); - /* Reset swap signature now */ - error = bio_write_page(0, &swsusp_header); - } else { - return -EINVAL; - } - if (error) - blkdev_put(resume_bdev); - else - pr_debug("swsusp: Signature found, resuming\n"); - } else { - error = PTR_ERR(resume_bdev); - } - - if (error) - pr_debug("swsusp: Error %d check for resume file\n", error); - - return error; -} - -/** - * swsusp_close - close swap device. - */ - -void swsusp_close(void) -{ - if (IS_ERR(resume_bdev)) { - pr_debug("swsusp: block device not initialised\n"); - return; - } - - blkdev_put(resume_bdev); -} |