/*
* linux/kernel/power/snapshot.c
*
- * This file provide system snapshot/restore functionality.
+ * This file provides system snapshot/restore functionality for swsusp.
*
* Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
*
- * This file is released under the GPLv2, and is based on swsusp.c.
+ * This file is released under the GPLv2.
*
*/
-
#include <linux/version.h>
#include <linux/module.h>
#include <linux/mm.h>
#include "power.h"
-/* List of PBEs used for creating and restoring the suspend image */
+/* List of PBEs needed for restoring the pages that were allocated before
+ * the suspend and included in the suspend image, but have also been
+ * allocated by the "resume" kernel, so their contents cannot be written
+ * directly to their "original" page frames.
+ */
struct pbe *restore_pblist;
-static unsigned int nr_copy_pages;
-static unsigned int nr_meta_pages;
+/* Pointer to an auxiliary buffer (1 page) */
static void *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;
-}
-#else
-static inline unsigned int count_highmem_pages(void) {return 0;}
-static inline int save_highmem(void) {return 0;}
-static inline int restore_highmem(void) {return 0;}
-#endif
-
/**
* @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
- * used before suspend.
+ * used before suspend. The unsafe pages have PageNosaveFree set
+ * and we count them using unsafe_pages.
*
- * The unsafe pages are marked with the PG_nosave_free flag
- * and we count them using unsafe_pages
+ * Each allocated image page is marked as PageNosave and PageNosaveFree
+ * so that swsusp_free() can release it.
*/
#define PG_ANY 0
static unsigned int allocated_unsafe_pages;
-static void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
+static void *get_image_page(gfp_t gfp_mask, int safe_needed)
{
void *res;
unsigned long get_safe_page(gfp_t gfp_mask)
{
- return (unsigned long)alloc_image_page(gfp_mask, PG_SAFE);
+ return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
+}
+
+static struct page *alloc_image_page(gfp_t gfp_mask) {
+ struct page *page;
+
+ page = alloc_page(gfp_mask);
+ if (page) {
+ SetPageNosave(page);
+ SetPageNosaveFree(page);
+ }
+ return page;
}
/**
* free_image_page - free page represented by @addr, allocated with
- * alloc_image_page (page flags set by it must be cleared)
+ * get_image_page (page flags set by it must be cleared)
*/
static inline void free_image_page(void *addr, int clear_nosave_free)
{
- ClearPageNosave(virt_to_page(addr));
+ struct page *page;
+
+ BUG_ON(!virt_addr_valid(addr));
+
+ page = virt_to_page(addr);
+
+ ClearPageNosave(page);
if (clear_nosave_free)
- ClearPageNosaveFree(virt_to_page(addr));
- free_page((unsigned long)addr);
+ ClearPageNosaveFree(page);
+
+ __free_page(page);
}
/* struct linked_page is used to build chains of pages */
if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
struct linked_page *lp;
- lp = alloc_image_page(ca->gfp_mask, ca->safe_needed);
+ lp = get_image_page(ca->gfp_mask, ca->safe_needed);
if (!lp)
return NULL;
/* Compute the number of zones */
nr = 0;
- for_each_zone (zone)
- if (populated_zone(zone) && !is_highmem(zone))
+ for_each_zone(zone)
+ if (populated_zone(zone))
nr++;
/* Allocate the list of zones bitmap objects */
}
/* Initialize the zone bitmap objects */
- for_each_zone (zone) {
+ for_each_zone(zone) {
unsigned long pfn;
- if (!populated_zone(zone) || is_highmem(zone))
+ if (!populated_zone(zone))
continue;
zone_bm->start_pfn = zone->zone_start_pfn;
while (bb) {
unsigned long *ptr;
- ptr = alloc_image_page(gfp_mask, safe_needed);
+ ptr = get_image_page(gfp_mask, safe_needed);
bb->data = ptr;
if (!ptr)
goto Free;
res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
- return res;
+ return 2 * res;
}
+#ifdef CONFIG_HIGHMEM
+/**
+ * count_free_highmem_pages - compute the total number of free highmem
+ * pages, system-wide.
+ */
+
+static unsigned int count_free_highmem_pages(void)
+{
+ struct zone *zone;
+ unsigned int cnt = 0;
+
+ for_each_zone(zone)
+ if (populated_zone(zone) && is_highmem(zone))
+ cnt += zone->free_pages;
+
+ return cnt;
+}
+
+/**
+ * saveable_highmem_page - Determine whether a highmem page should be
+ * included in the suspend image.
+ *
+ * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
+ * and it isn't a part of a free chunk of pages.
+ */
+
+static struct page *saveable_highmem_page(unsigned long pfn)
+{
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ return NULL;
+
+ page = pfn_to_page(pfn);
+
+ BUG_ON(!PageHighMem(page));
+
+ if (PageNosave(page) || PageReserved(page) || PageNosaveFree(page))
+ return NULL;
+
+ return page;
+}
+
+/**
+ * count_highmem_pages - compute the total number of saveable highmem
+ * pages.
+ */
+
+unsigned int count_highmem_pages(void)
+{
+ struct zone *zone;
+ unsigned int n = 0;
+
+ for_each_zone(zone) {
+ unsigned long pfn, max_zone_pfn;
+
+ if (!is_highmem(zone))
+ continue;
+
+ mark_free_pages(zone);
+ max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+ if (saveable_highmem_page(pfn))
+ n++;
+ }
+ return n;
+}
+#else
+static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
+static inline unsigned int count_highmem_pages(void) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
/**
* pfn_is_nosave - check if given pfn is in the 'nosave' section
*/
}
/**
- * saveable - Determine whether a page should be cloned or not.
- * @pfn: The page
+ * saveable - Determine whether a non-highmem page should be included in
+ * the suspend image.
*
- * We save a page if it isn't Nosave, and is not in the range of pages
- * statically defined as 'unsaveable', and it
- * isn't a part of a free chunk of pages.
+ * We should save the page if it isn't Nosave, and is not in the range
+ * of pages statically defined as 'unsaveable', and it isn't a part of
+ * a free chunk of pages.
*/
static struct page *saveable_page(unsigned long pfn)
page = pfn_to_page(pfn);
- if (PageNosave(page))
+ BUG_ON(PageHighMem(page));
+
+ if (PageNosave(page) || PageNosaveFree(page))
return NULL;
+
if (PageReserved(page) && pfn_is_nosave(pfn))
return NULL;
- if (PageNosaveFree(page))
- return NULL;
return page;
}
+/**
+ * count_data_pages - compute the total number of saveable non-highmem
+ * pages.
+ */
+
unsigned int count_data_pages(void)
{
struct zone *zone;
unsigned long pfn, max_zone_pfn;
unsigned int n = 0;
- for_each_zone (zone) {
+ for_each_zone(zone) {
if (is_highmem(zone))
continue;
+
mark_free_pages(zone);
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
- n += !!saveable_page(pfn);
+ if(saveable_page(pfn))
+ n++;
}
return n;
}
-static inline void copy_data_page(long *dst, long *src)
+/* This is needed, because copy_page and memcpy are not usable for copying
+ * task structs.
+ */
+static inline void do_copy_page(long *dst, long *src)
{
int n;
- /* copy_page and memcpy are not usable for copying task structs. */
for (n = PAGE_SIZE / sizeof(long); n; n--)
*dst++ = *src++;
}
+#ifdef CONFIG_HIGHMEM
+static inline struct page *
+page_is_saveable(struct zone *zone, unsigned long pfn)
+{
+ return is_highmem(zone) ?
+ saveable_highmem_page(pfn) : saveable_page(pfn);
+}
+
+static inline void
+copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+{
+ struct page *s_page, *d_page;
+ void *src, *dst;
+
+ s_page = pfn_to_page(src_pfn);
+ d_page = pfn_to_page(dst_pfn);
+ if (PageHighMem(s_page)) {
+ src = kmap_atomic(s_page, KM_USER0);
+ dst = kmap_atomic(d_page, KM_USER1);
+ do_copy_page(dst, src);
+ kunmap_atomic(src, KM_USER0);
+ kunmap_atomic(dst, KM_USER1);
+ } else {
+ src = page_address(s_page);
+ if (PageHighMem(d_page)) {
+ /* Page pointed to by src may contain some kernel
+ * data modified by kmap_atomic()
+ */
+ do_copy_page(buffer, src);
+ dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
+ memcpy(dst, buffer, PAGE_SIZE);
+ kunmap_atomic(dst, KM_USER0);
+ } else {
+ dst = page_address(d_page);
+ do_copy_page(dst, src);
+ }
+ }
+}
+#else
+#define page_is_saveable(zone, pfn) saveable_page(pfn)
+
+static inline void
+copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+{
+ do_copy_page(page_address(pfn_to_page(dst_pfn)),
+ page_address(pfn_to_page(src_pfn)));
+}
+#endif /* CONFIG_HIGHMEM */
+
static void
copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
{
struct zone *zone;
unsigned long pfn;
- for_each_zone (zone) {
+ for_each_zone(zone) {
unsigned long max_zone_pfn;
- if (is_highmem(zone))
- continue;
-
mark_free_pages(zone);
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
- if (saveable_page(pfn))
+ if (page_is_saveable(zone, pfn))
memory_bm_set_bit(orig_bm, pfn);
}
memory_bm_position_reset(orig_bm);
memory_bm_position_reset(copy_bm);
do {
pfn = memory_bm_next_pfn(orig_bm);
- if (likely(pfn != BM_END_OF_MAP)) {
- struct page *page;
- void *src;
-
- page = pfn_to_page(pfn);
- src = page_address(page);
- page = pfn_to_page(memory_bm_next_pfn(copy_bm));
- copy_data_page(page_address(page), src);
- }
+ if (likely(pfn != BM_END_OF_MAP))
+ copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
} while (pfn != BM_END_OF_MAP);
}
+/* Total number of image pages */
+static unsigned int nr_copy_pages;
+/* Number of pages needed for saving the original pfns of the image pages */
+static unsigned int nr_meta_pages;
+
/**
* swsusp_free - free pages allocated for the suspend.
*
if (PageNosave(page) && PageNosaveFree(page)) {
ClearPageNosave(page);
ClearPageNosaveFree(page);
- free_page((long) page_address(page));
+ __free_page(page);
}
}
}
buffer = NULL;
}
+#ifdef CONFIG_HIGHMEM
+/**
+ * count_pages_for_highmem - compute the number of non-highmem pages
+ * that will be necessary for creating copies of highmem pages.
+ */
+
+static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
+{
+ unsigned int free_highmem = count_free_highmem_pages();
+
+ if (free_highmem >= nr_highmem)
+ nr_highmem = 0;
+ else
+ nr_highmem -= free_highmem;
+
+ return nr_highmem;
+}
+#else
+static unsigned int
+count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
+#endif /* CONFIG_HIGHMEM */
/**
- * enough_free_mem - Make sure we enough free memory to snapshot.
- *
- * Returns TRUE or FALSE after checking the number of available
- * free pages.
+ * enough_free_mem - Make sure we have enough free memory for the
+ * snapshot image.
*/
-static int enough_free_mem(unsigned int nr_pages)
+static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
{
struct zone *zone;
unsigned int free = 0, meta = 0;
- for_each_zone (zone)
- if (!is_highmem(zone)) {
+ for_each_zone(zone) {
+ meta += snapshot_additional_pages(zone);
+ if (!is_highmem(zone))
free += zone->free_pages;
- meta += snapshot_additional_pages(zone);
- }
+ }
- pr_debug("swsusp: pages needed: %u + %u + %u, available pages: %u\n",
+ nr_pages += count_pages_for_highmem(nr_highmem);
+ pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
nr_pages, PAGES_FOR_IO, meta, free);
return free > nr_pages + PAGES_FOR_IO + meta;
}
+#ifdef CONFIG_HIGHMEM
+/**
+ * get_highmem_buffer - if there are some highmem pages in the suspend
+ * image, we may need the buffer to copy them and/or load their data.
+ */
+
+static inline int get_highmem_buffer(int safe_needed)
+{
+ buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
+ return buffer ? 0 : -ENOMEM;
+}
+
+/**
+ * alloc_highmem_image_pages - allocate some highmem pages for the image.
+ * Try to allocate as many pages as needed, but if the number of free
+ * highmem pages is lesser than that, allocate them all.
+ */
+
+static inline unsigned int
+alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
+{
+ unsigned int to_alloc = count_free_highmem_pages();
+
+ if (to_alloc > nr_highmem)
+ to_alloc = nr_highmem;
+
+ nr_highmem -= to_alloc;
+ while (to_alloc-- > 0) {
+ struct page *page;
+
+ page = alloc_image_page(__GFP_HIGHMEM);
+ memory_bm_set_bit(bm, page_to_pfn(page));
+ }
+ return nr_highmem;
+}
+#else
+static inline int get_highmem_buffer(int safe_needed) { return 0; }
+
+static inline unsigned int
+alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * swsusp_alloc - allocate memory for the suspend image
+ *
+ * We first try to allocate as many highmem pages as there are
+ * saveable highmem pages in the system. If that fails, we allocate
+ * non-highmem pages for the copies of the remaining highmem ones.
+ *
+ * In this approach it is likely that the copies of highmem pages will
+ * also be located in the high memory, because of the way in which
+ * copy_data_pages() works.
+ */
+
static int
swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
- unsigned int nr_pages)
+ unsigned int nr_pages, unsigned int nr_highmem)
{
int error;
if (error)
goto Free;
+ if (nr_highmem > 0) {
+ error = get_highmem_buffer(PG_ANY);
+ if (error)
+ goto Free;
+
+ nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem);
+ }
while (nr_pages-- > 0) {
- struct page *page = alloc_page(GFP_ATOMIC | __GFP_COLD);
+ struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
+
if (!page)
goto Free;
- SetPageNosave(page);
- SetPageNosaveFree(page);
memory_bm_set_bit(copy_bm, page_to_pfn(page));
}
return 0;
return -ENOMEM;
}
-/* Memory bitmap used for marking saveable pages */
+/* Memory bitmap used for marking saveable pages (during suspend) or the
+ * suspend image pages (during resume)
+ */
static struct memory_bitmap orig_bm;
-/* Memory bitmap used for marking allocated pages that will contain the copies
- * of saveable pages
+/* Memory bitmap used on suspend for marking allocated pages that will contain
+ * the copies of saveable pages. During resume it is initially used for
+ * marking the suspend image pages, but then its set bits are duplicated in
+ * @orig_bm and it is released. Next, on systems with high memory, it may be
+ * used for marking "safe" highmem pages, but it has to be reinitialized for
+ * this purpose.
*/
static struct memory_bitmap copy_bm;
asmlinkage int swsusp_save(void)
{
- unsigned int nr_pages;
+ unsigned int nr_pages, nr_highmem;
- pr_debug("swsusp: critical section: \n");
+ printk("swsusp: critical section: \n");
drain_local_pages();
nr_pages = count_data_pages();
- printk("swsusp: Need to copy %u pages\n", nr_pages);
+ nr_highmem = count_highmem_pages();
+ printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem);
- if (!enough_free_mem(nr_pages)) {
+ if (!enough_free_mem(nr_pages, nr_highmem)) {
printk(KERN_ERR "swsusp: Not enough free memory\n");
return -ENOMEM;
}
- if (swsusp_alloc(&orig_bm, ©_bm, nr_pages))
+ if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) {
+ printk(KERN_ERR "swsusp: Memory allocation failed\n");
return -ENOMEM;
+ }
/* During allocating of suspend pagedir, new cold pages may appear.
* Kill them.
* touch swap space! Except we must write out our image of course.
*/
+ nr_pages += nr_highmem;
nr_copy_pages = nr_pages;
- nr_meta_pages = (nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
+
return 0;
}
if (!buffer) {
/* This makes the buffer be freed by swsusp_free() */
- buffer = alloc_image_page(GFP_ATOMIC, PG_ANY);
+ buffer = get_image_page(GFP_ATOMIC, PG_ANY);
if (!buffer)
return -ENOMEM;
}
memset(buffer, 0, PAGE_SIZE);
pack_pfns(buffer, &orig_bm);
} else {
- unsigned long pfn = memory_bm_next_pfn(©_bm);
+ struct page *page;
- handle->buffer = page_address(pfn_to_page(pfn));
+ page = pfn_to_page(memory_bm_next_pfn(©_bm));
+ if (PageHighMem(page)) {
+ /* Highmem pages are copied to the buffer,
+ * because we can't return with a kmapped
+ * highmem page (we may not be called again).
+ */
+ void *kaddr;
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ memcpy(buffer, kaddr, PAGE_SIZE);
+ kunmap_atomic(kaddr, KM_USER0);
+ handle->buffer = buffer;
+ } else {
+ handle->buffer = page_address(page);
+ }
}
handle->prev = handle->cur;
}
unsigned long pfn, max_zone_pfn;
/* Clear page flags */
- for_each_zone (zone) {
+ for_each_zone(zone) {
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
if (pfn_valid(pfn))
}
}
+/* List of "safe" pages that may be used to store data loaded from the suspend
+ * image
+ */
+static struct linked_page *safe_pages_list;
+
+#ifdef CONFIG_HIGHMEM
+/* struct highmem_pbe is used for creating the list of highmem pages that
+ * should be restored atomically during the resume from disk, because the page
+ * frames they have occupied before the suspend are in use.
+ */
+struct highmem_pbe {
+ struct page *copy_page; /* data is here now */
+ struct page *orig_page; /* data was here before the suspend */
+ struct highmem_pbe *next;
+};
+
+/* List of highmem PBEs needed for restoring the highmem pages that were
+ * allocated before the suspend and included in the suspend image, but have
+ * also been allocated by the "resume" kernel, so their contents cannot be
+ * written directly to their "original" page frames.
+ */
+static struct highmem_pbe *highmem_pblist;
+
+/**
+ * count_highmem_image_pages - compute the number of highmem pages in the
+ * suspend image. The bits in the memory bitmap @bm that correspond to the
+ * image pages are assumed to be set.
+ */
+
+static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
+{
+ unsigned long pfn;
+ unsigned int cnt = 0;
+
+ memory_bm_position_reset(bm);
+ pfn = memory_bm_next_pfn(bm);
+ while (pfn != BM_END_OF_MAP) {
+ if (PageHighMem(pfn_to_page(pfn)))
+ cnt++;
+
+ pfn = memory_bm_next_pfn(bm);
+ }
+ return cnt;
+}
+
+/**
+ * prepare_highmem_image - try to allocate as many highmem pages as
+ * there are highmem image pages (@nr_highmem_p points to the variable
+ * containing the number of highmem image pages). The pages that are
+ * "safe" (ie. will not be overwritten when the suspend image is
+ * restored) have the corresponding bits set in @bm (it must be
+ * unitialized).
+ *
+ * NOTE: This function should not be called if there are no highmem
+ * image pages.
+ */
+
+static unsigned int safe_highmem_pages;
+
+static struct memory_bitmap *safe_highmem_bm;
+
+static int
+prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
+{
+ unsigned int to_alloc;
+
+ if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
+ return -ENOMEM;
+
+ if (get_highmem_buffer(PG_SAFE))
+ return -ENOMEM;
+
+ to_alloc = count_free_highmem_pages();
+ if (to_alloc > *nr_highmem_p)
+ to_alloc = *nr_highmem_p;
+ else
+ *nr_highmem_p = to_alloc;
+
+ safe_highmem_pages = 0;
+ while (to_alloc-- > 0) {
+ struct page *page;
+
+ page = alloc_page(__GFP_HIGHMEM);
+ if (!PageNosaveFree(page)) {
+ /* The page is "safe", set its bit the bitmap */
+ memory_bm_set_bit(bm, page_to_pfn(page));
+ safe_highmem_pages++;
+ }
+ /* Mark the page as allocated */
+ SetPageNosave(page);
+ SetPageNosaveFree(page);
+ }
+ memory_bm_position_reset(bm);
+ safe_highmem_bm = bm;
+ return 0;
+}
+
+/**
+ * get_highmem_page_buffer - for given highmem image page find the buffer
+ * that suspend_write_next() should set for its caller to write to.
+ *
+ * If the page is to be saved to its "original" page frame or a copy of
+ * the page is to be made in the highmem, @buffer is returned. Otherwise,
+ * the copy of the page is to be made in normal memory, so the address of
+ * the copy is returned.
+ *
+ * If @buffer is returned, the caller of suspend_write_next() will write
+ * the page's contents to @buffer, so they will have to be copied to the
+ * right location on the next call to suspend_write_next() and it is done
+ * with the help of copy_last_highmem_page(). For this purpose, if
+ * @buffer is returned, @last_highmem page is set to the page to which
+ * the data will have to be copied from @buffer.
+ */
+
+static struct page *last_highmem_page;
+
+static void *
+get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
+{
+ struct highmem_pbe *pbe;
+ void *kaddr;
+
+ if (PageNosave(page) && PageNosaveFree(page)) {
+ /* We have allocated the "original" page frame and we can
+ * use it directly to store the loaded page.
+ */
+ last_highmem_page = page;
+ return buffer;
+ }
+ /* The "original" page frame has not been allocated and we have to
+ * use a "safe" page frame to store the loaded page.
+ */
+ pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
+ if (!pbe) {
+ swsusp_free();
+ return NULL;
+ }
+ pbe->orig_page = page;
+ if (safe_highmem_pages > 0) {
+ struct page *tmp;
+
+ /* Copy of the page will be stored in high memory */
+ kaddr = buffer;
+ tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
+ safe_highmem_pages--;
+ last_highmem_page = tmp;
+ pbe->copy_page = tmp;
+ } else {
+ /* Copy of the page will be stored in normal memory */
+ kaddr = safe_pages_list;
+ safe_pages_list = safe_pages_list->next;
+ pbe->copy_page = virt_to_page(kaddr);
+ }
+ pbe->next = highmem_pblist;
+ highmem_pblist = pbe;
+ return kaddr;
+}
+
+/**
+ * copy_last_highmem_page - copy the contents of a highmem image from
+ * @buffer, where the caller of snapshot_write_next() has place them,
+ * to the right location represented by @last_highmem_page .
+ */
+
+static void copy_last_highmem_page(void)
+{
+ if (last_highmem_page) {
+ void *dst;
+
+ dst = kmap_atomic(last_highmem_page, KM_USER0);
+ memcpy(dst, buffer, PAGE_SIZE);
+ kunmap_atomic(dst, KM_USER0);
+ last_highmem_page = NULL;
+ }
+}
+
+static inline int last_highmem_page_copied(void)
+{
+ return !last_highmem_page;
+}
+
+static inline void free_highmem_data(void)
+{
+ if (safe_highmem_bm)
+ memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
+
+ if (buffer)
+ free_image_page(buffer, PG_UNSAFE_CLEAR);
+}
+#else
+static inline int get_safe_write_buffer(void) { return 0; }
+
+static unsigned int
+count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
+
+static inline int
+prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
+{
+ return 0;
+}
+
+static inline void *
+get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
+{
+ return NULL;
+}
+
+static inline void copy_last_highmem_page(void) {}
+static inline int last_highmem_page_copied(void) { return 1; }
+static inline void free_highmem_data(void) {}
+#endif /* CONFIG_HIGHMEM */
+
/**
* prepare_image - use the memory bitmap @bm to mark the pages that will
* be overwritten in the process of restoring the system memory state
* The idea is to allocate a new memory bitmap first and then allocate
* as many pages as needed for the image data, but not to assign these
* pages to specific tasks initially. Instead, we just mark them as
- * allocated and create a list of "safe" pages that will be used later.
+ * allocated and create a lists of "safe" pages that will be used
+ * later. On systems with high memory a list of "safe" highmem pages is
+ * also created.
*/
#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
-static struct linked_page *safe_pages_list;
-
static int
prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
{
- unsigned int nr_pages;
+ unsigned int nr_pages, nr_highmem;
struct linked_page *sp_list, *lp;
int error;
+ /* If there is no highmem, the buffer will not be necessary */
+ free_image_page(buffer, PG_UNSAFE_CLEAR);
+ buffer = NULL;
+
+ nr_highmem = count_highmem_image_pages(bm);
error = mark_unsafe_pages(bm);
if (error)
goto Free;
duplicate_memory_bitmap(new_bm, bm);
memory_bm_free(bm, PG_UNSAFE_KEEP);
+ if (nr_highmem > 0) {
+ error = prepare_highmem_image(bm, &nr_highmem);
+ if (error)
+ goto Free;
+ }
/* Reserve some safe pages for potential later use.
*
* NOTE: This way we make sure there will be enough safe pages for the
*/
sp_list = NULL;
/* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
- nr_pages = nr_copy_pages - allocated_unsafe_pages;
+ nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
while (nr_pages > 0) {
- lp = alloc_image_page(GFP_ATOMIC, PG_SAFE);
+ lp = get_image_page(GFP_ATOMIC, PG_SAFE);
if (!lp) {
error = -ENOMEM;
goto Free;
}
/* Preallocate memory for the image */
safe_pages_list = NULL;
- nr_pages = nr_copy_pages - allocated_unsafe_pages;
+ nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
while (nr_pages > 0) {
lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
if (!lp) {
struct pbe *pbe;
struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
+ if (PageHighMem(page))
+ return get_highmem_page_buffer(page, ca);
+
if (PageNosave(page) && PageNosaveFree(page))
/* We have allocated the "original" page frame and we can
* use it directly to store the loaded page.
swsusp_free();
return NULL;
}
- pbe->orig_address = (unsigned long)page_address(page);
- pbe->address = (unsigned long)safe_pages_list;
+ pbe->orig_address = page_address(page);
+ pbe->address = safe_pages_list;
safe_pages_list = safe_pages_list->next;
pbe->next = restore_pblist;
restore_pblist = pbe;
- return (void *)pbe->address;
+ return pbe->address;
}
/**
if (handle->prev && handle->cur > 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, PG_ANY);
+ if (handle->offset == 0) {
+ if (!buffer)
+ /* This makes the buffer be freed by swsusp_free() */
+ buffer = get_image_page(GFP_ATOMIC, PG_ANY);
+
if (!buffer)
return -ENOMEM;
- }
- if (!handle->offset)
+
handle->buffer = buffer;
+ }
handle->sync_read = 1;
if (handle->prev < handle->cur) {
if (handle->prev == 0) {
return -ENOMEM;
}
} else {
+ copy_last_highmem_page();
handle->buffer = get_buffer(&orig_bm, &ca);
- handle->sync_read = 0;
+ if (handle->buffer != buffer)
+ handle->sync_read = 0;
}
handle->prev = handle->cur;
}
return count;
}
+/**
+ * snapshot_write_finalize - must be called after the last call to
+ * snapshot_write_next() in case the last page in the image happens
+ * to be a highmem page and its contents should be stored in the
+ * highmem. Additionally, it releases the memory that will not be
+ * used any more.
+ */
+
+void snapshot_write_finalize(struct snapshot_handle *handle)
+{
+ copy_last_highmem_page();
+ /* Free only if we have loaded the image entirely */
+ if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages) {
+ memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
+ free_highmem_data();
+ }
+}
+
int snapshot_image_loaded(struct snapshot_handle *handle)
{
- return !(!nr_copy_pages ||
+ return !(!nr_copy_pages || !last_highmem_page_copied() ||
handle->cur <= nr_meta_pages + nr_copy_pages);
}
-void snapshot_free_unused_memory(struct snapshot_handle *handle)
+#ifdef CONFIG_HIGHMEM
+/* Assumes that @buf is ready and points to a "safe" page */
+static inline void
+swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
{
- /* Free only if we have loaded the image entirely */
- if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
- memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
+ void *kaddr1, *kaddr2;
+
+ kaddr1 = kmap_atomic(p1, KM_USER0);
+ kaddr2 = kmap_atomic(p2, KM_USER1);
+ memcpy(buf, kaddr1, PAGE_SIZE);
+ memcpy(kaddr1, kaddr2, PAGE_SIZE);
+ memcpy(kaddr2, buf, PAGE_SIZE);
+ kunmap_atomic(kaddr1, KM_USER0);
+ kunmap_atomic(kaddr2, KM_USER1);
+}
+
+/**
+ * restore_highmem - for each highmem page that was allocated before
+ * the suspend and included in the suspend image, and also has been
+ * allocated by the "resume" kernel swap its current (ie. "before
+ * resume") contents with the previous (ie. "before suspend") one.
+ *
+ * If the resume eventually fails, we can call this function once
+ * again and restore the "before resume" highmem state.
+ */
+
+int restore_highmem(void)
+{
+ struct highmem_pbe *pbe = highmem_pblist;
+ void *buf;
+
+ if (!pbe)
+ return 0;
+
+ buf = get_image_page(GFP_ATOMIC, PG_SAFE);
+ if (!buf)
+ return -ENOMEM;
+
+ while (pbe) {
+ swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
+ pbe = pbe->next;
+ }
+ free_image_page(buf, PG_UNSAFE_CLEAR);
+ return 0;
}
+#endif /* CONFIG_HIGHMEM */
projects / openwrt / staging / blogic.git / commitdiff