| /* |
| * 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 <linux/rbtree.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; |
| |
| /** |
| * The following functions are used for tracing the allocated |
| * swap pages, so that they can be freed in case of an error. |
| */ |
| |
| struct swsusp_extent { |
| struct rb_node node; |
| unsigned long start; |
| unsigned long end; |
| }; |
| |
| static struct rb_root swsusp_extents = RB_ROOT; |
| |
| static int swsusp_extents_insert(unsigned long swap_offset) |
| { |
| struct rb_node **new = &(swsusp_extents.rb_node); |
| struct rb_node *parent = NULL; |
| struct swsusp_extent *ext; |
| |
| /* Figure out where to put the new node */ |
| while (*new) { |
| ext = container_of(*new, struct swsusp_extent, node); |
| parent = *new; |
| if (swap_offset < ext->start) { |
| /* Try to merge */ |
| if (swap_offset == ext->start - 1) { |
| ext->start--; |
| return 0; |
| } |
| new = &((*new)->rb_left); |
| } else if (swap_offset > ext->end) { |
| /* Try to merge */ |
| if (swap_offset == ext->end + 1) { |
| ext->end++; |
| return 0; |
| } |
| new = &((*new)->rb_right); |
| } else { |
| /* It already is in the tree */ |
| return -EINVAL; |
| } |
| } |
| /* Add the new node and rebalance the tree. */ |
| ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); |
| if (!ext) |
| return -ENOMEM; |
| |
| ext->start = swap_offset; |
| ext->end = swap_offset; |
| rb_link_node(&ext->node, parent, new); |
| rb_insert_color(&ext->node, &swsusp_extents); |
| return 0; |
| } |
| |
| /** |
| * alloc_swapdev_block - allocate a swap page and register that it has |
| * been allocated, so that it can be freed in case of an error. |
| */ |
| |
| sector_t alloc_swapdev_block(int swap) |
| { |
| unsigned long offset; |
| |
| offset = swp_offset(get_swap_page_of_type(swap)); |
| if (offset) { |
| if (swsusp_extents_insert(offset)) |
| swap_free(swp_entry(swap, offset)); |
| else |
| return swapdev_block(swap, offset); |
| } |
| return 0; |
| } |
| |
| /** |
| * free_all_swap_pages - free swap pages allocated for saving image data. |
| * It also frees the extents used to register which swap entres had been |
| * allocated. |
| */ |
| |
| void free_all_swap_pages(int swap) |
| { |
| struct rb_node *node; |
| |
| while ((node = swsusp_extents.rb_node)) { |
| struct swsusp_extent *ext; |
| unsigned long offset; |
| |
| ext = container_of(node, struct swsusp_extent, node); |
| rb_erase(node, &swsusp_extents); |
| for (offset = ext->start; offset <= ext->end; offset++) |
| swap_free(swp_entry(swap, offset)); |
| |
| kfree(ext); |
| } |
| } |
| |
| int swsusp_swap_in_use(void) |
| { |
| return (swsusp_extents.rb_node != NULL); |
| } |
| |
| /** |
| * 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(KERN_INFO "PM: %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(KERN_INFO "PM: Shrinking memory... "); |
| do_gettimeofday(&start); |
| do { |
| long size, highmem_size; |
| |
| highmem_size = count_highmem_pages(); |
| size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES; |
| tmp = size; |
| size += highmem_size; |
| for_each_populated_zone(zone) { |
| tmp += snapshot_additional_pages(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]; |
| } |
| } |
| |
| 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; |
| } |
| |
| /* |
| * Platforms, like ACPI, may want us to save some memory used by them during |
| * hibernation and to restore the contents of this memory during the subsequent |
| * resume. The code below implements a mechanism allowing us to do that. |
| */ |
| |
| struct nvs_page { |
| unsigned long phys_start; |
| unsigned int size; |
| void *kaddr; |
| void *data; |
| struct list_head node; |
| }; |
| |
| static LIST_HEAD(nvs_list); |
| |
| /** |
| * hibernate_nvs_register - register platform NVS memory region to save |
| * @start - physical address of the region |
| * @size - size of the region |
| * |
| * The NVS region need not be page-aligned (both ends) and we arrange |
| * things so that the data from page-aligned addresses in this region will |
| * be copied into separate RAM pages. |
| */ |
| int hibernate_nvs_register(unsigned long start, unsigned long size) |
| { |
| struct nvs_page *entry, *next; |
| |
| while (size > 0) { |
| unsigned int nr_bytes; |
| |
| entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL); |
| if (!entry) |
| goto Error; |
| |
| list_add_tail(&entry->node, &nvs_list); |
| entry->phys_start = start; |
| nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK); |
| entry->size = (size < nr_bytes) ? size : nr_bytes; |
| |
| start += entry->size; |
| size -= entry->size; |
| } |
| return 0; |
| |
| Error: |
| list_for_each_entry_safe(entry, next, &nvs_list, node) { |
| list_del(&entry->node); |
| kfree(entry); |
| } |
| return -ENOMEM; |
| } |
| |
| /** |
| * hibernate_nvs_free - free data pages allocated for saving NVS regions |
| */ |
| void hibernate_nvs_free(void) |
| { |
| struct nvs_page *entry; |
| |
| list_for_each_entry(entry, &nvs_list, node) |
| if (entry->data) { |
| free_page((unsigned long)entry->data); |
| entry->data = NULL; |
| if (entry->kaddr) { |
| iounmap(entry->kaddr); |
| entry->kaddr = NULL; |
| } |
| } |
| } |
| |
| /** |
| * hibernate_nvs_alloc - allocate memory necessary for saving NVS regions |
| */ |
| int hibernate_nvs_alloc(void) |
| { |
| struct nvs_page *entry; |
| |
| list_for_each_entry(entry, &nvs_list, node) { |
| entry->data = (void *)__get_free_page(GFP_KERNEL); |
| if (!entry->data) { |
| hibernate_nvs_free(); |
| return -ENOMEM; |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * hibernate_nvs_save - save NVS memory regions |
| */ |
| void hibernate_nvs_save(void) |
| { |
| struct nvs_page *entry; |
| |
| printk(KERN_INFO "PM: Saving platform NVS memory\n"); |
| |
| list_for_each_entry(entry, &nvs_list, node) |
| if (entry->data) { |
| entry->kaddr = ioremap(entry->phys_start, entry->size); |
| memcpy(entry->data, entry->kaddr, entry->size); |
| } |
| } |
| |
| /** |
| * hibernate_nvs_restore - restore NVS memory regions |
| * |
| * This function is going to be called with interrupts disabled, so it |
| * cannot iounmap the virtual addresses used to access the NVS region. |
| */ |
| void hibernate_nvs_restore(void) |
| { |
| struct nvs_page *entry; |
| |
| printk(KERN_INFO "PM: Restoring platform NVS memory\n"); |
| |
| list_for_each_entry(entry, &nvs_list, node) |
| if (entry->data) |
| memcpy(entry->kaddr, entry->data, entry->size); |
| } |