1 files changed, 435 insertions, 0 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
new file mode 100644
index 00000000000..42a62870439
--- /dev/null
+++ b/kernel/power/snapshot.c
@@ -0,0 +1,435 @@
+/*
+ * 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;
+}
+
+
+static 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;
+}
+#else
+static int save_highmem(void) { return 0; }
+int restore_highmem(void) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+
+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 n;
+
+	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()
+ */
+
+static 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 nr_pages)
+{
+	struct pbe *pbpage, *p;
+	unsigned 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);
+}
+
+static void *alloc_image_page(void)
+{
+	void *res = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
+	if (res) {
+		SetPageNosave(virt_to_page(res));
+		SetPageNosaveFree(virt_to_page(res));
+	}
+	return res;
+}
+
+/**
+ *	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 nr_pages)
+{
+	unsigned num;
+	struct pbe *pblist, *pbe;
+
+	if (!nr_pages)
+		return NULL;
+
+	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
+	pblist = alloc_image_page();
+	/* 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();
+	}
+	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 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);
+}
+
+
+static struct pbe *swsusp_alloc(unsigned nr_pages)
+{
+	struct pbe *pblist, *p;
+
+	if (!(pblist = alloc_pagedir(nr_pages))) {
+		printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
+		return NULL;
+	}
+	create_pbe_list(pblist, nr_pages);
+
+	for_each_pbe (p, pblist) {
+		p->address = (unsigned long)alloc_image_page();
+		if (!p->address) {
+			printk(KERN_ERR "suspend: Allocating image pages failed.\n");
+			swsusp_free();
+			return NULL;
+		}
+	}
+
+	return pblist;
+}
+
+asmlinkage int swsusp_save(void)
+{
+	unsigned nr_pages;
+
+	pr_debug("swsusp: critical section: \n");
+	if (save_highmem()) {
+		printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
+		restore_highmem();
+		return -ENOMEM;
+	}
+
+	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;
+	}
+
+	if (!enough_swap(nr_pages)) {
+		printk(KERN_ERR "swsusp: Not enough free swap\n");
+		return -ENOSPC;
+	}
+
+	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;
+}