1 files changed, 435 insertions, 0 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
new file mode 100644
index 000000000000..42a628704398
--- /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;
+}