--- /dev/null
+/*
+ * 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/version.h>
+#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"
+
+struct pbe *pagedir_nosave;
+static unsigned int nr_copy_pages;
+static unsigned int nr_meta_pages;
+static unsigned long *buffer;
+
+#ifdef CONFIG_HIGHMEM
+unsigned int count_highmem_pages(void)
+{
+ struct zone *zone;
+ unsigned long zone_pfn;
+ unsigned int n = 0;
+
+ for_each_zone (zone)
+ if (is_highmem(zone)) {
+ mark_free_pages(zone);
+ for (zone_pfn = 0; zone_pfn < zone->spanned_pages; zone_pfn++) {
+ struct page *page;
+ unsigned long pfn = zone_pfn + zone->zone_start_pfn;
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+ if (PageReserved(page))
+ continue;
+ if (PageNosaveFree(page))
+ continue;
+ n++;
+ }
+ }
+ return n;
+}
+
+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%10000))
+ 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))
+ 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");
+ drain_local_pages();
+ for_each_zone (zone) {
+ if (is_highmem(zone))
+ res = save_highmem_zone(zone);
+ if (res)
+ return res;
+ }
+ printk("\n");
+ 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))
+ return 0;
+ if (PageNosaveFree(page))
+ return 0;
+
+ return 1;
+}
+
+unsigned int 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()
+ */
+
+static void free_pagedir(struct pbe *pblist, int clear_nosave_free)
+{
+ struct pbe *pbe;
+
+ while (pblist) {
+ pbe = (pblist + PB_PAGE_SKIP)->next;
+ ClearPageNosave(virt_to_page(pblist));
+ if (clear_nosave_free)
+ 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()
+ */
+
+static inline 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;
+ }
+}
+
+/**
+ * On resume it is necessary to trace and eventually free the unsafe
+ * pages that have been allocated, because they are needed for I/O
+ * (on x86-64 we likely will "eat" these pages once again while
+ * creating the temporary page translation tables)
+ */
+
+struct eaten_page {
+ struct eaten_page *next;
+ char padding[PAGE_SIZE - sizeof(void *)];
+};
+
+static struct eaten_page *eaten_pages = NULL;
+
+static void release_eaten_pages(void)
+{
+ struct eaten_page *p, *q;
+
+ p = eaten_pages;
+ while (p) {
+ q = p->next;
+ /* We don't want swsusp_free() to free this page again */
+ ClearPageNosave(virt_to_page(p));
+ free_page((unsigned long)p);
+ p = q;
+ }
+ eaten_pages = NULL;
+}
+
+/**
+ * @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));
+ ((struct eaten_page *)res)->next = eaten_pages;
+ eaten_pages = 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;
+
+ 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, 1);
+ pblist = NULL;
+ } else
+ create_pbe_list(pblist, nr_pages);
+ 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));
+ }
+ }
+ }
+ nr_copy_pages = 0;
+ nr_meta_pages = 0;
+ pagedir_nosave = NULL;
+ buffer = NULL;
+}
+
+
+/**
+ * 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)
+{
+ struct zone *zone;
+ unsigned int n = 0;
+
+ for_each_zone (zone)
+ if (!is_highmem(zone))
+ n += zone->free_pages;
+ pr_debug("swsusp: available memory: %u pages\n", n);
+ return n > (nr_pages + PAGES_FOR_IO +
+ (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+}
+
+static 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;
+ }
+
+ 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());
+
+ 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;
+ nr_meta_pages = (nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
+ return 0;
+}
+
+static void init_header(struct swsusp_info *info)
+{
+ memset(info, 0, sizeof(struct swsusp_info));
+ info->version_code = LINUX_VERSION_CODE;
+ info->num_physpages = num_physpages;
+ memcpy(&info->uts, &system_utsname, sizeof(system_utsname));
+ info->cpus = num_online_cpus();
+ info->image_pages = nr_copy_pages;
+ info->pages = nr_copy_pages + nr_meta_pages + 1;
+ info->size = info->pages;
+ info->size <<= PAGE_SHIFT;
+}
+
+/**
+ * pack_orig_addresses - the .orig_address fields of the PBEs from the
+ * list starting at @pbe are stored in the array @buf[] (1 page)
+ */
+
+static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+ buf[j] = pbe->orig_address;
+ pbe = pbe->next;
+ }
+ if (!pbe)
+ for (; j < PAGE_SIZE / sizeof(long); j++)
+ buf[j] = 0;
+ return pbe;
+}
+
+/**
+ * snapshot_read_next - used for reading the system memory snapshot.
+ *
+ * On the first call to it @handle should point to a zeroed
+ * snapshot_handle structure. The structure gets updated and a pointer
+ * to it should be passed to this function every next time.
+ *
+ * The @count parameter should contain the number of bytes the caller
+ * wants to read from the snapshot. It must not be zero.
+ *
+ * On success the function returns a positive number. Then, the caller
+ * is allowed to read up to the returned number of bytes from the memory
+ * location computed by the data_of() macro. The number returned
+ * may be smaller than @count, but this only happens if the read would
+ * cross a page boundary otherwise.
+ *
+ * The function returns 0 to indicate the end of data stream condition,
+ * and a negative number is returned on error. In such cases the
+ * structure pointed to by @handle is not updated and should not be used
+ * any more.
+ */
+
+int snapshot_read_next(struct snapshot_handle *handle, size_t count)
+{
+ if (handle->page > nr_meta_pages + nr_copy_pages)
+ return 0;
+ if (!buffer) {
+ /* This makes the buffer be freed by swsusp_free() */
+ buffer = alloc_image_page(GFP_ATOMIC, 0);
+ if (!buffer)
+ return -ENOMEM;
+ }
+ if (!handle->offset) {
+ init_header((struct swsusp_info *)buffer);
+ handle->buffer = buffer;
+ handle->pbe = pagedir_nosave;
+ }
+ if (handle->prev < handle->page) {
+ if (handle->page <= nr_meta_pages) {
+ handle->pbe = pack_orig_addresses(buffer, handle->pbe);
+ if (!handle->pbe)
+ handle->pbe = pagedir_nosave;
+ } else {
+ handle->buffer = (void *)handle->pbe->address;
+ handle->pbe = handle->pbe->next;
+ }
+ handle->prev = handle->page;
+ }
+ handle->buf_offset = handle->page_offset;
+ if (handle->page_offset + count >= PAGE_SIZE) {
+ count = PAGE_SIZE - handle->page_offset;
+ handle->page_offset = 0;
+ handle->page++;
+ } else {
+ handle->page_offset += count;
+ }
+ handle->offset += count;
+ return count;
+}
+
+/**
+ * mark_unsafe_pages - mark the pages that cannot be used for storing
+ * the image during resume, because they conflict with the pages that
+ * had been used before suspend
+ */
+
+static int mark_unsafe_pages(struct pbe *pblist)
+{
+ struct zone *zone;
+ unsigned long zone_pfn;
+ struct pbe *p;
+
+ if (!pblist) /* a sanity check */
+ return -EINVAL;
+
+ /* Clear page flags */
+ for_each_zone (zone) {
+ for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
+ if (pfn_valid(zone_pfn + zone->zone_start_pfn))
+ ClearPageNosaveFree(pfn_to_page(zone_pfn +
+ zone->zone_start_pfn));
+ }
+
+ /* Mark orig addresses */
+ for_each_pbe (p, pblist) {
+ if (virt_addr_valid(p->orig_address))
+ SetPageNosaveFree(virt_to_page(p->orig_address));
+ else
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
+{
+ /* We assume both lists contain the same number of elements */
+ while (src) {
+ dst->orig_address = src->orig_address;
+ dst = dst->next;
+ src = src->next;
+ }
+}
+
+static int check_header(struct swsusp_info *info)
+{
+ char *reason = NULL;
+
+ if (info->version_code != LINUX_VERSION_CODE)
+ reason = "kernel version";
+ if (info->num_physpages != num_physpages)
+ reason = "memory size";
+ if (strcmp(info->uts.sysname,system_utsname.sysname))
+ reason = "system type";
+ if (strcmp(info->uts.release,system_utsname.release))
+ reason = "kernel release";
+ if (strcmp(info->uts.version,system_utsname.version))
+ reason = "version";
+ if (strcmp(info->uts.machine,system_utsname.machine))
+ reason = "machine";
+ if (reason) {
+ printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
+ return -EPERM;
+ }
+ return 0;
+}
+
+/**
+ * load header - check the image header and copy data from it
+ */
+
+static int load_header(struct snapshot_handle *handle,
+ struct swsusp_info *info)
+{
+ int error;
+ struct pbe *pblist;
+
+ error = check_header(info);
+ if (!error) {
+ pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, 0);
+ if (!pblist)
+ return -ENOMEM;
+ pagedir_nosave = pblist;
+ handle->pbe = pblist;
+ nr_copy_pages = info->image_pages;
+ nr_meta_pages = info->pages - info->image_pages - 1;
+ }
+ return error;
+}
+
+/**
+ * unpack_orig_addresses - copy the elements of @buf[] (1 page) to
+ * the PBEs in the list starting at @pbe
+ */
+
+static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
+ struct pbe *pbe)
+{
+ int j;
+
+ for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+ pbe->orig_address = buf[j];
+ pbe = pbe->next;
+ }
+ return pbe;
+}
+
+/**
+ * create_image - use metadata contained in the PBE list
+ * pointed to by pagedir_nosave to mark the pages that will
+ * be overwritten in the process of restoring the system
+ * memory state from the image and allocate memory for
+ * the image avoiding these pages
+ */
+
+static int create_image(struct snapshot_handle *handle)
+{
+ int error = 0;
+ struct pbe *p, *pblist;
+
+ p = pagedir_nosave;
+ error = mark_unsafe_pages(p);
+ if (!error) {
+ pblist = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1);
+ if (pblist)
+ copy_page_backup_list(pblist, p);
+ free_pagedir(p, 0);
+ if (!pblist)
+ error = -ENOMEM;
+ }
+ if (!error)
+ error = alloc_data_pages(pblist, GFP_ATOMIC, 1);
+ if (!error) {
+ release_eaten_pages();
+ pagedir_nosave = pblist;
+ } else {
+ pagedir_nosave = NULL;
+ handle->pbe = NULL;
+ nr_copy_pages = 0;
+ nr_meta_pages = 0;
+ }
+ return error;
+}
+
+/**
+ * snapshot_write_next - used for writing the system memory snapshot.
+ *
+ * On the first call to it @handle should point to a zeroed
+ * snapshot_handle structure. The structure gets updated and a pointer
+ * to it should be passed to this function every next time.
+ *
+ * The @count parameter should contain the number of bytes the caller
+ * wants to write to the image. It must not be zero.
+ *
+ * On success the function returns a positive number. Then, the caller
+ * is allowed to write up to the returned number of bytes to the memory
+ * location computed by the data_of() macro. The number returned
+ * may be smaller than @count, but this only happens if the write would
+ * cross a page boundary otherwise.
+ *
+ * The function returns 0 to indicate the "end of file" condition,
+ * and a negative number is returned on error. In such cases the
+ * structure pointed to by @handle is not updated and should not be used
+ * any more.
+ */
+
+int snapshot_write_next(struct snapshot_handle *handle, size_t count)
+{
+ int error = 0;
+
+ if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages)
+ return 0;
+ if (!buffer) {
+ /* This makes the buffer be freed by swsusp_free() */
+ buffer = alloc_image_page(GFP_ATOMIC, 0);
+ if (!buffer)
+ return -ENOMEM;
+ }
+ if (!handle->offset)
+ handle->buffer = buffer;
+ if (handle->prev < handle->page) {
+ if (!handle->prev) {
+ error = load_header(handle, (struct swsusp_info *)buffer);
+ if (error)
+ return error;
+ } else if (handle->prev <= nr_meta_pages) {
+ handle->pbe = unpack_orig_addresses(buffer, handle->pbe);
+ if (!handle->pbe) {
+ error = create_image(handle);
+ if (error)
+ return error;
+ handle->pbe = pagedir_nosave;
+ handle->buffer = (void *)handle->pbe->address;
+ }
+ } else {
+ handle->pbe = handle->pbe->next;
+ handle->buffer = (void *)handle->pbe->address;
+ }
+ handle->prev = handle->page;
+ }
+ handle->buf_offset = handle->page_offset;
+ if (handle->page_offset + count >= PAGE_SIZE) {
+ count = PAGE_SIZE - handle->page_offset;
+ handle->page_offset = 0;
+ handle->page++;
+ } else {
+ handle->page_offset += count;
+ }
+ handle->offset += count;
+ return count;
+}
+
+int snapshot_image_loaded(struct snapshot_handle *handle)
+{
+ return !(!handle->pbe || handle->pbe->next || !nr_copy_pages ||
+ handle->page <= nr_meta_pages + nr_copy_pages);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff