/* * 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 * Copyright (C) 1998,2001-2005 Pavel Machek * * This file is released under the GPLv2. * * I'd like to thank the following people for their work: * * Pavel Machek : * 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 : * Support the possibility of hardware state restoring. * * Raph : * Support for preserving states of network devices and virtual console * (including X and svgatextmode) * * Kurt Garloff : * Straightened the critical function in order to prevent compilers from * playing tricks with local variables. * * Andreas Mohr * * Alex Badea : * Fixed runaway init * * Rafael J. Wysocki * 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 #include #include #include #include #include #include #include #include #include #include #include #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; }