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-rw-r--r--kernel/power/snapshot.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
new file mode 100644
index 00000000000..4a6dbcefd37
--- /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;
+}