| /* |
| * linux/kernel/power/swsusp.c |
| * |
| * This file provides code to write suspend image to swap and read it back. |
| * |
| * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu> |
| * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> |
| * |
| * This file is released under the GPLv2. |
| * |
| * I'd like to thank the following people for their work: |
| * |
| * Pavel Machek <pavel@ucw.cz>: |
| * Modifications, defectiveness pointing, being with me at the very beginning, |
| * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17. |
| * |
| * Steve Doddi <dirk@loth.demon.co.uk>: |
| * Support the possibility of hardware state restoring. |
| * |
| * Raph <grey.havens@earthling.net>: |
| * Support for preserving states of network devices and virtual console |
| * (including X and svgatextmode) |
| * |
| * Kurt Garloff <garloff@suse.de>: |
| * Straightened the critical function in order to prevent compilers from |
| * playing tricks with local variables. |
| * |
| * Andreas Mohr <a.mohr@mailto.de> |
| * |
| * Alex Badea <vampire@go.ro>: |
| * Fixed runaway init |
| * |
| * Rafael J. Wysocki <rjw@sisk.pl> |
| * 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/mm.h> |
| #include <linux/suspend.h> |
| #include <linux/spinlock.h> |
| #include <linux/kernel.h> |
| #include <linux/major.h> |
| #include <linux/swap.h> |
| #include <linux/pm.h> |
| #include <linux/swapops.h> |
| #include <linux/bootmem.h> |
| #include <linux/syscalls.h> |
| #include <linux/highmem.h> |
| #include <linux/time.h> |
| |
| #include "power.h" |
| |
| /* |
| * Preferred image size in bytes (tunable via /sys/power/image_size). |
| * When it is set to N, swsusp will do its best to ensure the image |
| * size will not exceed N bytes, but if that is impossible, it will |
| * try to create the smallest image possible. |
| */ |
| unsigned long image_size = 500 * 1024 * 1024; |
| |
| int in_suspend __nosavedata = 0; |
| |
| #ifdef CONFIG_HIGHMEM |
| unsigned int count_highmem_pages(void); |
| int restore_highmem(void); |
| #else |
| static inline int restore_highmem(void) { return 0; } |
| static inline unsigned int count_highmem_pages(void) { return 0; } |
| #endif |
| |
| /** |
| * 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 |
| * in power.h |
| */ |
| |
| void free_bitmap(struct bitmap_page *bitmap) |
| { |
| struct bitmap_page *bp; |
| |
| while (bitmap) { |
| bp = bitmap->next; |
| free_page((unsigned long)bitmap); |
| bitmap = bp; |
| } |
| } |
| |
| struct bitmap_page *alloc_bitmap(unsigned int nr_bits) |
| { |
| struct bitmap_page *bitmap, *bp; |
| unsigned int n; |
| |
| if (!nr_bits) |
| return NULL; |
| |
| bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL); |
| bp = bitmap; |
| for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) { |
| bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL); |
| bp = bp->next; |
| if (!bp) { |
| free_bitmap(bitmap); |
| return NULL; |
| } |
| } |
| return bitmap; |
| } |
| |
| static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit) |
| { |
| unsigned int n; |
| |
| n = BITMAP_PAGE_BITS; |
| while (bitmap && n <= bit) { |
| n += BITMAP_PAGE_BITS; |
| bitmap = bitmap->next; |
| } |
| if (!bitmap) |
| return -EINVAL; |
| n -= BITMAP_PAGE_BITS; |
| bit -= n; |
| n = 0; |
| while (bit >= BITS_PER_CHUNK) { |
| bit -= BITS_PER_CHUNK; |
| n++; |
| } |
| bitmap->chunks[n] |= (1UL << bit); |
| return 0; |
| } |
| |
| sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap) |
| { |
| unsigned long offset; |
| |
| offset = swp_offset(get_swap_page_of_type(swap)); |
| if (offset) { |
| if (bitmap_set(bitmap, offset)) |
| swap_free(swp_entry(swap, offset)); |
| else |
| return swapdev_block(swap, offset); |
| } |
| return 0; |
| } |
| |
| void free_all_swap_pages(int swap, struct bitmap_page *bitmap) |
| { |
| unsigned int bit, n; |
| unsigned long test; |
| |
| bit = 0; |
| while (bitmap) { |
| for (n = 0; n < BITMAP_PAGE_CHUNKS; n++) |
| for (test = 1UL; test; test <<= 1) { |
| if (bitmap->chunks[n] & test) |
| swap_free(swp_entry(swap, bit)); |
| bit++; |
| } |
| bitmap = bitmap->next; |
| } |
| } |
| |
| /** |
| * swsusp_show_speed - print the time elapsed between two events represented by |
| * @start and @stop |
| * |
| * @nr_pages - number of pages processed between @start and @stop |
| * @msg - introductory message to print |
| */ |
| |
| void swsusp_show_speed(struct timeval *start, struct timeval *stop, |
| unsigned nr_pages, char *msg) |
| { |
| s64 elapsed_centisecs64; |
| int centisecs; |
| int k; |
| int kps; |
| |
| elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start); |
| do_div(elapsed_centisecs64, NSEC_PER_SEC / 100); |
| centisecs = elapsed_centisecs64; |
| if (centisecs == 0) |
| centisecs = 1; /* avoid div-by-zero */ |
| k = nr_pages * (PAGE_SIZE / 1024); |
| kps = (k * 100) / centisecs; |
| printk("%s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", msg, k, |
| centisecs / 100, centisecs % 100, |
| kps / 1000, (kps % 1000) / 10); |
| } |
| |
| /** |
| * swsusp_shrink_memory - Try to free as much memory as needed |
| * |
| * ... but do not OOM-kill anyone |
| * |
| * Notice: all userland should be stopped before it is called, or |
| * livelock is possible. |
| */ |
| |
| #define SHRINK_BITE 10000 |
| static inline unsigned long __shrink_memory(long tmp) |
| { |
| if (tmp > SHRINK_BITE) |
| tmp = SHRINK_BITE; |
| return shrink_all_memory(tmp); |
| } |
| |
| int swsusp_shrink_memory(void) |
| { |
| long tmp; |
| struct zone *zone; |
| unsigned long pages = 0; |
| unsigned int i = 0; |
| char *p = "-\\|/"; |
| struct timeval start, stop; |
| |
| printk("Shrinking memory... "); |
| do_gettimeofday(&start); |
| do { |
| long size, highmem_size; |
| |
| highmem_size = count_highmem_pages(); |
| size = count_data_pages() + PAGES_FOR_IO; |
| tmp = size; |
| size += highmem_size; |
| for_each_zone (zone) |
| if (populated_zone(zone)) { |
| if (is_highmem(zone)) { |
| highmem_size -= |
| zone_page_state(zone, NR_FREE_PAGES); |
| } else { |
| tmp -= zone_page_state(zone, NR_FREE_PAGES); |
| tmp += zone->lowmem_reserve[ZONE_NORMAL]; |
| tmp += snapshot_additional_pages(zone); |
| } |
| } |
| |
| if (highmem_size < 0) |
| highmem_size = 0; |
| |
| tmp += highmem_size; |
| if (tmp > 0) { |
| tmp = __shrink_memory(tmp); |
| if (!tmp) |
| return -ENOMEM; |
| pages += tmp; |
| } else if (size > image_size / PAGE_SIZE) { |
| tmp = __shrink_memory(size - (image_size / PAGE_SIZE)); |
| pages += tmp; |
| } |
| printk("\b%c", p[i++%4]); |
| } while (tmp > 0); |
| do_gettimeofday(&stop); |
| printk("\bdone (%lu pages freed)\n", pages); |
| swsusp_show_speed(&start, &stop, pages, "Freed"); |
| |
| return 0; |
| } |
| |
| int swsusp_suspend(void) |
| { |
| int error; |
| |
| if ((error = arch_prepare_suspend())) |
| return error; |
| |
| local_irq_disable(); |
| /* At this point, device_suspend() has been called, but *not* |
| * device_power_down(). We *must* device_power_down() now. |
| * Otherwise, drivers for some devices (e.g. interrupt controllers) |
| * become desynchronized with the actual state of the hardware |
| * at resume time, and evil weirdness ensues. |
| */ |
| if ((error = device_power_down(PMSG_FREEZE))) { |
| printk(KERN_ERR "Some devices failed to power down, aborting suspend\n"); |
| goto Enable_irqs; |
| } |
| |
| save_processor_state(); |
| if ((error = swsusp_arch_suspend())) |
| printk(KERN_ERR "Error %d suspending\n", error); |
| /* Restore control flow magically appears here */ |
| restore_processor_state(); |
| /* NOTE: device_power_up() is just a resume() for devices |
| * that suspended with irqs off ... no overall powerup. |
| */ |
| device_power_up(); |
| Enable_irqs: |
| local_irq_enable(); |
| return error; |
| } |
| |
| int swsusp_resume(void) |
| { |
| int error; |
| |
| local_irq_disable(); |
| /* NOTE: device_power_down() is just a suspend() with irqs off; |
| * it has no special "power things down" semantics |
| */ |
| if (device_power_down(PMSG_PRETHAW)) |
| printk(KERN_ERR "Some devices failed to power down, very bad\n"); |
| /* We'll ignore saved state, but this gets preempt count (etc) right */ |
| save_processor_state(); |
| error = restore_highmem(); |
| if (!error) { |
| error = swsusp_arch_resume(); |
| /* The code below is only ever reached in case of a failure. |
| * Otherwise execution continues at place where |
| * swsusp_arch_suspend() was called |
| */ |
| BUG_ON(!error); |
| /* This call to restore_highmem() undos the previous one */ |
| restore_highmem(); |
| } |
| /* The only reason why swsusp_arch_resume() can fail is memory being |
| * very tight, so we have to free it as soon as we can to avoid |
| * subsequent failures |
| */ |
| swsusp_free(); |
| restore_processor_state(); |
| touch_softlockup_watchdog(); |
| device_power_up(); |
| local_irq_enable(); |
| return error; |
| } |