mm: introduce for_each_populated_zone() macro
[safe/jmp/linux-2.6] / kernel / power / snapshot.c
index b703977..33e2e4a 100644 (file)
@@ -25,6 +25,7 @@
 #include <linux/syscalls.h>
 #include <linux/console.h>
 #include <linux/highmem.h>
+#include <linux/list.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
@@ -192,12 +193,6 @@ static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
        return ret;
 }
 
-static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
-{
-       free_list_of_pages(ca->chain, clear_page_nosave);
-       memset(ca, 0, sizeof(struct chain_allocator));
-}
-
 /**
  *     Data types related to memory bitmaps.
  *
@@ -205,8 +200,7 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
  *     objects.  The main list's elements are of type struct zone_bitmap
  *     and each of them corresonds to one zone.  For each zone bitmap
  *     object there is a list of objects of type struct bm_block that
- *     represent each blocks of bit chunks in which information is
- *     stored.
+ *     represent each blocks of bitmap in which information is stored.
  *
  *     struct memory_bitmap contains a pointer to the main list of zone
  *     bitmap objects, a struct bm_position used for browsing the bitmap,
@@ -224,45 +218,36 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
  *     pfns that correspond to the start and end of the represented zone.
  *
  *     struct bm_block contains a pointer to the memory page in which
- *     information is stored (in the form of a block of bit chunks
- *     of type unsigned long each).  It also contains the pfns that
- *     correspond to the start and end of the represented memory area and
- *     the number of bit chunks in the block.
+ *     information is stored (in the form of a block of bitmap)
+ *     It also contains the pfns that correspond to the start and end of
+ *     the represented memory area.
  */
 
 #define BM_END_OF_MAP  (~0UL)
 
-#define BM_CHUNKS_PER_BLOCK    (PAGE_SIZE / sizeof(long))
-#define BM_BITS_PER_CHUNK      (sizeof(long) << 3)
 #define BM_BITS_PER_BLOCK      (PAGE_SIZE << 3)
 
 struct bm_block {
-       struct bm_block *next;          /* next element of the list */
+       struct list_head hook;  /* hook into a list of bitmap blocks */
        unsigned long start_pfn;        /* pfn represented by the first bit */
        unsigned long end_pfn;  /* pfn represented by the last bit plus 1 */
-       unsigned int size;      /* number of bit chunks */
-       unsigned long *data;    /* chunks of bits representing pages */
+       unsigned long *data;    /* bitmap representing pages */
 };
 
-struct zone_bitmap {
-       struct zone_bitmap *next;       /* next element of the list */
-       unsigned long start_pfn;        /* minimal pfn in this zone */
-       unsigned long end_pfn;          /* maximal pfn in this zone plus 1 */
-       struct bm_block *bm_blocks;     /* list of bitmap blocks */
-       struct bm_block *cur_block;     /* recently used bitmap block */
-};
+static inline unsigned long bm_block_bits(struct bm_block *bb)
+{
+       return bb->end_pfn - bb->start_pfn;
+}
 
 /* strcut bm_position is used for browsing memory bitmaps */
 
 struct bm_position {
-       struct zone_bitmap *zone_bm;
        struct bm_block *block;
-       int chunk;
        int bit;
 };
 
 struct memory_bitmap {
-       struct zone_bitmap *zone_bm_list;       /* list of zone bitmaps */
+       struct list_head blocks;        /* list of bitmap blocks */
        struct linked_page *p_list;     /* list of pages used to store zone
                                         * bitmap objects and bitmap block
                                         * objects
@@ -272,173 +257,191 @@ struct memory_bitmap {
 
 /* Functions that operate on memory bitmaps */
 
-static inline void memory_bm_reset_chunk(struct memory_bitmap *bm)
-{
-       bm->cur.chunk = 0;
-       bm->cur.bit = -1;
-}
-
 static void memory_bm_position_reset(struct memory_bitmap *bm)
 {
-       struct zone_bitmap *zone_bm;
-
-       zone_bm = bm->zone_bm_list;
-       bm->cur.zone_bm = zone_bm;
-       bm->cur.block = zone_bm->bm_blocks;
-       memory_bm_reset_chunk(bm);
+       bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook);
+       bm->cur.bit = 0;
 }
 
 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
 
 /**
  *     create_bm_block_list - create a list of block bitmap objects
+ *     @nr_blocks - number of blocks to allocate
+ *     @list - list to put the allocated blocks into
+ *     @ca - chain allocator to be used for allocating memory
  */
-
-static inline struct bm_block *
-create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
+static int create_bm_block_list(unsigned long pages,
+                               struct list_head *list,
+                               struct chain_allocator *ca)
 {
-       struct bm_block *bblist = NULL;
+       unsigned int nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
 
        while (nr_blocks-- > 0) {
                struct bm_block *bb;
 
                bb = chain_alloc(ca, sizeof(struct bm_block));
                if (!bb)
-                       return NULL;
-
-               bb->next = bblist;
-               bblist = bb;
+                       return -ENOMEM;
+               list_add(&bb->hook, list);
        }
-       return bblist;
+
+       return 0;
 }
 
+struct mem_extent {
+       struct list_head hook;
+       unsigned long start;
+       unsigned long end;
+};
+
 /**
- *     create_zone_bm_list - create a list of zone bitmap objects
+ *     free_mem_extents - free a list of memory extents
+ *     @list - list of extents to empty
  */
+static void free_mem_extents(struct list_head *list)
+{
+       struct mem_extent *ext, *aux;
 
-static inline struct zone_bitmap *
-create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
+       list_for_each_entry_safe(ext, aux, list, hook) {
+               list_del(&ext->hook);
+               kfree(ext);
+       }
+}
+
+/**
+ *     create_mem_extents - create a list of memory extents representing
+ *                          contiguous ranges of PFNs
+ *     @list - list to put the extents into
+ *     @gfp_mask - mask to use for memory allocations
+ */
+static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
 {
-       struct zone_bitmap *zbmlist = NULL;
+       struct zone *zone;
 
-       while (nr_zones-- > 0) {
-               struct zone_bitmap *zbm;
+       INIT_LIST_HEAD(list);
 
-               zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
-               if (!zbm)
-                       return NULL;
+       for_each_populated_zone(zone) {
+               unsigned long zone_start, zone_end;
+               struct mem_extent *ext, *cur, *aux;
+
+               zone_start = zone->zone_start_pfn;
+               zone_end = zone->zone_start_pfn + zone->spanned_pages;
+
+               list_for_each_entry(ext, list, hook)
+                       if (zone_start <= ext->end)
+                               break;
+
+               if (&ext->hook == list || zone_end < ext->start) {
+                       /* New extent is necessary */
+                       struct mem_extent *new_ext;
+
+                       new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
+                       if (!new_ext) {
+                               free_mem_extents(list);
+                               return -ENOMEM;
+                       }
+                       new_ext->start = zone_start;
+                       new_ext->end = zone_end;
+                       list_add_tail(&new_ext->hook, &ext->hook);
+                       continue;
+               }
 
-               zbm->next = zbmlist;
-               zbmlist = zbm;
+               /* Merge this zone's range of PFNs with the existing one */
+               if (zone_start < ext->start)
+                       ext->start = zone_start;
+               if (zone_end > ext->end)
+                       ext->end = zone_end;
+
+               /* More merging may be possible */
+               cur = ext;
+               list_for_each_entry_safe_continue(cur, aux, list, hook) {
+                       if (zone_end < cur->start)
+                               break;
+                       if (zone_end < cur->end)
+                               ext->end = cur->end;
+                       list_del(&cur->hook);
+                       kfree(cur);
+               }
        }
-       return zbmlist;
+
+       return 0;
 }
 
 /**
   *    memory_bm_create - allocate memory for a memory bitmap
   */
-
 static int
 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
 {
        struct chain_allocator ca;
-       struct zone *zone;
-       struct zone_bitmap *zone_bm;
-       struct bm_block *bb;
-       unsigned int nr;
+       struct list_head mem_extents;
+       struct mem_extent *ext;
+       int error;
 
        chain_init(&ca, gfp_mask, safe_needed);
+       INIT_LIST_HEAD(&bm->blocks);
 
-       /* Compute the number of zones */
-       nr = 0;
-       for_each_zone(zone)
-               if (populated_zone(zone))
-                       nr++;
-
-       /* Allocate the list of zones bitmap objects */
-       zone_bm = create_zone_bm_list(nr, &ca);
-       bm->zone_bm_list = zone_bm;
-       if (!zone_bm) {
-               chain_free(&ca, PG_UNSAFE_CLEAR);
-               return -ENOMEM;
-       }
-
-       /* Initialize the zone bitmap objects */
-       for_each_zone(zone) {
-               unsigned long pfn;
+       error = create_mem_extents(&mem_extents, gfp_mask);
+       if (error)
+               return error;
 
-               if (!populated_zone(zone))
-                       continue;
+       list_for_each_entry(ext, &mem_extents, hook) {
+               struct bm_block *bb;
+               unsigned long pfn = ext->start;
+               unsigned long pages = ext->end - ext->start;
 
-               zone_bm->start_pfn = zone->zone_start_pfn;
-               zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages;
-               /* Allocate the list of bitmap block objects */
-               nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
-               bb = create_bm_block_list(nr, &ca);
-               zone_bm->bm_blocks = bb;
-               zone_bm->cur_block = bb;
-               if (!bb)
-                       goto Free;
+               bb = list_entry(bm->blocks.prev, struct bm_block, hook);
 
-               nr = zone->spanned_pages;
-               pfn = zone->zone_start_pfn;
-               /* Initialize the bitmap block objects */
-               while (bb) {
-                       unsigned long *ptr;
+               error = create_bm_block_list(pages, bm->blocks.prev, &ca);
+               if (error)
+                       goto Error;
 
-                       ptr = get_image_page(gfp_mask, safe_needed);
-                       bb->data = ptr;
-                       if (!ptr)
-                               goto Free;
+               list_for_each_entry_continue(bb, &bm->blocks, hook) {
+                       bb->data = get_image_page(gfp_mask, safe_needed);
+                       if (!bb->data) {
+                               error = -ENOMEM;
+                               goto Error;
+                       }
 
                        bb->start_pfn = pfn;
-                       if (nr >= BM_BITS_PER_BLOCK) {
+                       if (pages >= BM_BITS_PER_BLOCK) {
                                pfn += BM_BITS_PER_BLOCK;
-                               bb->size = BM_CHUNKS_PER_BLOCK;
-                               nr -= BM_BITS_PER_BLOCK;
+                               pages -= BM_BITS_PER_BLOCK;
                        } else {
                                /* This is executed only once in the loop */
-                               pfn += nr;
-                               bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK);
+                               pfn += pages;
                        }
                        bb->end_pfn = pfn;
-                       bb = bb->next;
                }
-               zone_bm = zone_bm->next;
        }
+
        bm->p_list = ca.chain;
        memory_bm_position_reset(bm);
-       return 0;
+ Exit:
+       free_mem_extents(&mem_extents);
+       return error;
 
Free:
Error:
        bm->p_list = ca.chain;
        memory_bm_free(bm, PG_UNSAFE_CLEAR);
-       return -ENOMEM;
+       goto Exit;
 }
 
 /**
   *    memory_bm_free - free memory occupied by the memory bitmap @bm
   */
-
 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
 {
-       struct zone_bitmap *zone_bm;
+       struct bm_block *bb;
 
-       /* Free the list of bit blocks for each zone_bitmap object */
-       zone_bm = bm->zone_bm_list;
-       while (zone_bm) {
-               struct bm_block *bb;
+       list_for_each_entry(bb, &bm->blocks, hook)
+               if (bb->data)
+                       free_image_page(bb->data, clear_nosave_free);
 
-               bb = zone_bm->bm_blocks;
-               while (bb) {
-                       if (bb->data)
-                               free_image_page(bb->data, clear_nosave_free);
-                       bb = bb->next;
-               }
-               zone_bm = zone_bm->next;
-       }
        free_list_of_pages(bm->p_list, clear_nosave_free);
-       bm->zone_bm_list = NULL;
+
+       INIT_LIST_HEAD(&bm->blocks);
 }
 
 /**
@@ -446,96 +449,89 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
  *     to given pfn.  The cur_zone_bm member of @bm and the cur_block member
  *     of @bm->cur_zone_bm are updated.
  */
-
-static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
+static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
                                void **addr, unsigned int *bit_nr)
 {
-       struct zone_bitmap *zone_bm;
        struct bm_block *bb;
 
-       /* Check if the pfn is from the current zone */
-       zone_bm = bm->cur.zone_bm;
-       if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
-               zone_bm = bm->zone_bm_list;
-               /* We don't assume that the zones are sorted by pfns */
-               while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
-                       zone_bm = zone_bm->next;
-
-                       BUG_ON(!zone_bm);
-               }
-               bm->cur.zone_bm = zone_bm;
-       }
-       /* Check if the pfn corresponds to the current bitmap block */
-       bb = zone_bm->cur_block;
+       /*
+        * Check if the pfn corresponds to the current bitmap block and find
+        * the block where it fits if this is not the case.
+        */
+       bb = bm->cur.block;
        if (pfn < bb->start_pfn)
-               bb = zone_bm->bm_blocks;
+               list_for_each_entry_continue_reverse(bb, &bm->blocks, hook)
+                       if (pfn >= bb->start_pfn)
+                               break;
 
-       while (pfn >= bb->end_pfn) {
-               bb = bb->next;
+       if (pfn >= bb->end_pfn)
+               list_for_each_entry_continue(bb, &bm->blocks, hook)
+                       if (pfn >= bb->start_pfn && pfn < bb->end_pfn)
+                               break;
 
-               BUG_ON(!bb);
-       }
-       zone_bm->cur_block = bb;
+       if (&bb->hook == &bm->blocks)
+               return -EFAULT;
+
+       /* The block has been found */
+       bm->cur.block = bb;
        pfn -= bb->start_pfn;
-       *bit_nr = pfn % BM_BITS_PER_CHUNK;
-       *addr = bb->data + pfn / BM_BITS_PER_CHUNK;
+       bm->cur.bit = pfn + 1;
+       *bit_nr = pfn;
+       *addr = bb->data;
+       return 0;
 }
 
 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
        void *addr;
        unsigned int bit;
+       int error;
 
-       memory_bm_find_bit(bm, pfn, &addr, &bit);
+       error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+       BUG_ON(error);
        set_bit(bit, addr);
 }
 
-static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
+static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
 {
        void *addr;
        unsigned int bit;
+       int error;
 
-       memory_bm_find_bit(bm, pfn, &addr, &bit);
-       clear_bit(bit, addr);
+       error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+       if (!error)
+               set_bit(bit, addr);
+       return error;
 }
 
-static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
+static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
        void *addr;
        unsigned int bit;
+       int error;
 
-       memory_bm_find_bit(bm, pfn, &addr, &bit);
-       return test_bit(bit, addr);
+       error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+       BUG_ON(error);
+       clear_bit(bit, addr);
 }
 
-/* Two auxiliary functions for memory_bm_next_pfn */
-
-/* Find the first set bit in the given chunk, if there is one */
-
-static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
+static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
 {
-       bit++;
-       while (bit < BM_BITS_PER_CHUNK) {
-               if (test_bit(bit, chunk_p))
-                       return bit;
+       void *addr;
+       unsigned int bit;
+       int error;
 
-               bit++;
-       }
-       return -1;
+       error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+       BUG_ON(error);
+       return test_bit(bit, addr);
 }
 
-/* Find a chunk containing some bits set in given block of bits */
-
-static inline int next_chunk_in_block(int n, struct bm_block *bb)
+static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
 {
-       n++;
-       while (n < bb->size) {
-               if (bb->data[n])
-                       return n;
+       void *addr;
+       unsigned int bit;
 
-               n++;
-       }
-       return -1;
+       return !memory_bm_find_bit(bm, pfn, &addr, &bit);
 }
 
 /**
@@ -549,42 +545,27 @@ static inline int next_chunk_in_block(int n, struct bm_block *bb)
 
 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
 {
-       struct zone_bitmap *zone_bm;
        struct bm_block *bb;
-       int chunk;
        int bit;
 
+       bb = bm->cur.block;
        do {
-               bb = bm->cur.block;
-               do {
-                       chunk = bm->cur.chunk;
-                       bit = bm->cur.bit;
-                       do {
-                               bit = next_bit_in_chunk(bit, bb->data + chunk);
-                               if (bit >= 0)
-                                       goto Return_pfn;
-
-                               chunk = next_chunk_in_block(chunk, bb);
-                               bit = -1;
-                       } while (chunk >= 0);
-                       bb = bb->next;
-                       bm->cur.block = bb;
-                       memory_bm_reset_chunk(bm);
-               } while (bb);
-               zone_bm = bm->cur.zone_bm->next;
-               if (zone_bm) {
-                       bm->cur.zone_bm = zone_bm;
-                       bm->cur.block = zone_bm->bm_blocks;
-                       memory_bm_reset_chunk(bm);
-               }
-       } while (zone_bm);
+               bit = bm->cur.bit;
+               bit = find_next_bit(bb->data, bm_block_bits(bb), bit);
+               if (bit < bm_block_bits(bb))
+                       goto Return_pfn;
+
+               bb = list_entry(bb->hook.next, struct bm_block, hook);
+               bm->cur.block = bb;
+               bm->cur.bit = 0;
+       } while (&bb->hook != &bm->blocks);
+
        memory_bm_position_reset(bm);
        return BM_END_OF_MAP;
 
  Return_pfn:
-       bm->cur.chunk = chunk;
-       bm->cur.bit = bit;
-       return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit;
+       bm->cur.bit = bit + 1;
+       return bb->start_pfn + bit;
 }
 
 /**
@@ -607,7 +588,8 @@ static LIST_HEAD(nosave_regions);
  */
 
 void __init
-register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
+__register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
+                        int use_kmalloc)
 {
        struct nosave_region *region;
 
@@ -623,13 +605,18 @@ register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
                        goto Report;
                }
        }
-       /* This allocation cannot fail */
-       region = alloc_bootmem_low(sizeof(struct nosave_region));
+       if (use_kmalloc) {
+               /* during init, this shouldn't fail */
+               region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
+               BUG_ON(!region);
+       } else
+               /* This allocation cannot fail */
+               region = alloc_bootmem_low(sizeof(struct nosave_region));
        region->start_pfn = start_pfn;
        region->end_pfn = end_pfn;
        list_add_tail(&region->list, &nosave_regions);
  Report:
-       printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
+       printk(KERN_INFO "PM: Registered nosave memory: %016lx - %016lx\n",
                start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
 }
 
@@ -698,12 +685,20 @@ static void mark_nosave_pages(struct memory_bitmap *bm)
        list_for_each_entry(region, &nosave_regions, list) {
                unsigned long pfn;
 
-               printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
+               pr_debug("PM: Marking nosave pages: %016lx - %016lx\n",
                                region->start_pfn << PAGE_SHIFT,
                                region->end_pfn << PAGE_SHIFT);
 
                for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
-                       memory_bm_set_bit(bm, pfn);
+                       if (pfn_valid(pfn)) {
+                               /*
+                                * It is safe to ignore the result of
+                                * mem_bm_set_bit_check() here, since we won't
+                                * touch the PFNs for which the error is
+                                * returned anyway.
+                                */
+                               mem_bm_set_bit_check(bm, pfn);
+                       }
        }
 }
 
@@ -742,7 +737,7 @@ int create_basic_memory_bitmaps(void)
        free_pages_map = bm2;
        mark_nosave_pages(forbidden_pages_map);
 
-       printk("swsusp: Basic memory bitmaps created\n");
+       pr_debug("PM: Basic memory bitmaps created\n");
 
        return 0;
 
@@ -777,7 +772,7 @@ void free_basic_memory_bitmaps(void)
        memory_bm_free(bm2, PG_UNSAFE_CLEAR);
        kfree(bm2);
 
-       printk("swsusp: Basic memory bitmaps freed\n");
+       pr_debug("PM: Basic memory bitmaps freed\n");
 }
 
 /**
@@ -806,8 +801,8 @@ 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))
+       for_each_populated_zone(zone)
+               if (is_highmem(zone))
                        cnt += zone_page_state(zone, NR_FREE_PAGES);
 
        return cnt;
@@ -820,8 +815,7 @@ static unsigned int count_free_highmem_pages(void)
  *     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)
+static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
 {
        struct page *page;
 
@@ -829,6 +823,8 @@ static struct page *saveable_highmem_page(unsigned long pfn)
                return NULL;
 
        page = pfn_to_page(pfn);
+       if (page_zone(page) != zone)
+               return NULL;
 
        BUG_ON(!PageHighMem(page));
 
@@ -858,26 +854,27 @@ unsigned int count_highmem_pages(void)
                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))
+                       if (saveable_highmem_page(zone, 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; }
+static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
+{
+       return NULL;
+}
 #endif /* CONFIG_HIGHMEM */
 
 /**
- *     saveable - Determine whether a non-highmem page should be included in
- *     the suspend image.
+ *     saveable_page - Determine whether a non-highmem page should be included
+ *     in the suspend image.
  *
  *     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)
+static struct page *saveable_page(struct zone *zone, unsigned long pfn)
 {
        struct page *page;
 
@@ -885,13 +882,16 @@ static struct page *saveable_page(unsigned long pfn)
                return NULL;
 
        page = pfn_to_page(pfn);
+       if (page_zone(page) != zone)
+               return NULL;
 
        BUG_ON(PageHighMem(page));
 
        if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
                return NULL;
 
-       if (PageReserved(page) && pfn_is_nosave(pfn))
+       if (PageReserved(page)
+           && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
                return NULL;
 
        return page;
@@ -915,7 +915,7 @@ unsigned int count_data_pages(void)
                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 (saveable_page(zone, pfn))
                                n++;
        }
        return n;
@@ -932,16 +932,34 @@ static inline void do_copy_page(long *dst, long *src)
                *dst++ = *src++;
 }
 
+
+/**
+ *     safe_copy_page - check if the page we are going to copy is marked as
+ *             present in the kernel page tables (this always is the case if
+ *             CONFIG_DEBUG_PAGEALLOC is not set and in that case
+ *             kernel_page_present() always returns 'true').
+ */
+static void safe_copy_page(void *dst, struct page *s_page)
+{
+       if (kernel_page_present(s_page)) {
+               do_copy_page(dst, page_address(s_page));
+       } else {
+               kernel_map_pages(s_page, 1, 1);
+               do_copy_page(dst, page_address(s_page));
+               kernel_map_pages(s_page, 1, 0);
+       }
+}
+
+
 #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);
+               saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
 }
 
-static inline void
-copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
 {
        struct page *s_page, *d_page;
        void *src, *dst;
@@ -955,29 +973,26 @@ copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
                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);
+                       safe_copy_page(buffer, s_page);
+                       dst = kmap_atomic(d_page, KM_USER0);
                        memcpy(dst, buffer, PAGE_SIZE);
                        kunmap_atomic(dst, KM_USER0);
                } else {
-                       dst = page_address(d_page);
-                       do_copy_page(dst, src);
+                       safe_copy_page(page_address(d_page), s_page);
                }
        }
 }
 #else
-#define page_is_saveable(zone, pfn)    saveable_page(pfn)
+#define page_is_saveable(zone, pfn)    saveable_page(zone, pfn)
 
-static inline void
-copy_data_page(unsigned long dst_pfn, unsigned long src_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)));
+       safe_copy_page(page_address(pfn_to_page(dst_pfn)),
+                               pfn_to_page(src_pfn));
 }
 #endif /* CONFIG_HIGHMEM */
 
@@ -998,11 +1013,12 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
        }
        memory_bm_position_reset(orig_bm);
        memory_bm_position_reset(copy_bm);
-       do {
+       for(;;) {
                pfn = memory_bm_next_pfn(orig_bm);
-               if (likely(pfn != BM_END_OF_MAP))
-                       copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
-       } while (pfn != BM_END_OF_MAP);
+               if (unlikely(pfn == BM_END_OF_MAP))
+                       break;
+               copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
+       }
 }
 
 /* Total number of image pages */
@@ -1081,7 +1097,7 @@ static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
        }
 
        nr_pages += count_pages_for_highmem(nr_highmem);
-       pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
+       pr_debug("PM: 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;
@@ -1194,27 +1210,27 @@ asmlinkage int swsusp_save(void)
 {
        unsigned int nr_pages, nr_highmem;
 
-       printk("swsusp: critical section: \n");
+       printk(KERN_INFO "PM: Creating hibernation image: \n");
 
-       drain_local_pages();
+       drain_local_pages(NULL);
        nr_pages = count_data_pages();
        nr_highmem = count_highmem_pages();
-       printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem);
+       printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem);
 
        if (!enough_free_mem(nr_pages, nr_highmem)) {
-               printk(KERN_ERR "swsusp: Not enough free memory\n");
+               printk(KERN_ERR "PM: Not enough free memory\n");
                return -ENOMEM;
        }
 
        if (swsusp_alloc(&orig_bm, &copy_bm, nr_pages, nr_highmem)) {
-               printk(KERN_ERR "swsusp: Memory allocation failed\n");
+               printk(KERN_ERR "PM: Memory allocation failed\n");
                return -ENOMEM;
        }
 
        /* During allocating of suspend pagedir, new cold pages may appear.
         * Kill them.
         */
-       drain_local_pages();
+       drain_local_pages(NULL);
        copy_data_pages(&copy_bm, &orig_bm);
 
        /*
@@ -1227,22 +1243,50 @@ asmlinkage int swsusp_save(void)
        nr_copy_pages = nr_pages;
        nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
 
-       printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
+       printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n",
+               nr_pages);
 
        return 0;
 }
 
-static void init_header(struct swsusp_info *info)
+#ifndef CONFIG_ARCH_HIBERNATION_HEADER
+static int init_header_complete(struct swsusp_info *info)
 {
-       memset(info, 0, sizeof(struct swsusp_info));
+       memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
        info->version_code = LINUX_VERSION_CODE;
+       return 0;
+}
+
+static char *check_image_kernel(struct swsusp_info *info)
+{
+       if (info->version_code != LINUX_VERSION_CODE)
+               return "kernel version";
+       if (strcmp(info->uts.sysname,init_utsname()->sysname))
+               return "system type";
+       if (strcmp(info->uts.release,init_utsname()->release))
+               return "kernel release";
+       if (strcmp(info->uts.version,init_utsname()->version))
+               return "version";
+       if (strcmp(info->uts.machine,init_utsname()->machine))
+               return "machine";
+       return NULL;
+}
+#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
+
+unsigned long snapshot_get_image_size(void)
+{
+       return nr_copy_pages + nr_meta_pages + 1;
+}
+
+static int init_header(struct swsusp_info *info)
+{
+       memset(info, 0, sizeof(struct swsusp_info));
        info->num_physpages = num_physpages;
-       memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
-       info->cpus = num_online_cpus();
        info->image_pages = nr_copy_pages;
-       info->pages = nr_copy_pages + nr_meta_pages + 1;
+       info->pages = snapshot_get_image_size();
        info->size = info->pages;
        info->size <<= PAGE_SHIFT;
+       return init_header_complete(info);
 }
 
 /**
@@ -1296,7 +1340,11 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
                        return -ENOMEM;
        }
        if (!handle->offset) {
-               init_header((struct swsusp_info *)buffer);
+               int error;
+
+               error = init_header((struct swsusp_info *)buffer);
+               if (error)
+                       return error;
                handle->buffer = buffer;
                memory_bm_position_reset(&orig_bm);
                memory_bm_position_reset(&copy_bm);
@@ -1387,24 +1435,15 @@ duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
        }
 }
 
-static inline int check_header(struct swsusp_info *info)
+static int check_header(struct swsusp_info *info)
 {
-       char *reason = NULL;
+       char *reason;
 
-       if (info->version_code != LINUX_VERSION_CODE)
-               reason = "kernel version";
-       if (info->num_physpages != num_physpages)
+       reason = check_image_kernel(info);
+       if (!reason && info->num_physpages != num_physpages)
                reason = "memory size";
-       if (strcmp(info->uts.sysname,init_utsname()->sysname))
-               reason = "system type";
-       if (strcmp(info->uts.release,init_utsname()->release))
-               reason = "kernel release";
-       if (strcmp(info->uts.version,init_utsname()->version))
-               reason = "version";
-       if (strcmp(info->uts.machine,init_utsname()->machine))
-               reason = "machine";
        if (reason) {
-               printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
+               printk(KERN_ERR "PM: Image mismatch: %s\n", reason);
                return -EPERM;
        }
        return 0;
@@ -1432,9 +1471,7 @@ load_header(struct swsusp_info *info)
  *     unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
  *     the corresponding bit in the memory bitmap @bm
  */
-
-static inline void
-unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
+static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
 {
        int j;
 
@@ -1442,8 +1479,13 @@ unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
                if (unlikely(buf[j] == BM_END_OF_MAP))
                        break;
 
-               memory_bm_set_bit(bm, buf[j]);
+               if (memory_bm_pfn_present(bm, buf[j]))
+                       memory_bm_set_bit(bm, buf[j]);
+               else
+                       return -EFAULT;
        }
+
+       return 0;
 }
 
 /* List of "safe" pages that may be used to store data loaded from the suspend
@@ -1581,7 +1623,7 @@ get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
        pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
        if (!pbe) {
                swsusp_free();
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
        pbe->orig_page = page;
        if (safe_highmem_pages > 0) {
@@ -1650,7 +1692,7 @@ prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
 static inline void *
 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
 {
-       return NULL;
+       return ERR_PTR(-EINVAL);
 }
 
 static inline void copy_last_highmem_page(void) {}
@@ -1761,8 +1803,13 @@ prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
 {
        struct pbe *pbe;
-       struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
+       struct page *page;
+       unsigned long pfn = memory_bm_next_pfn(bm);
+
+       if (pfn == BM_END_OF_MAP)
+               return ERR_PTR(-EFAULT);
 
+       page = pfn_to_page(pfn);
        if (PageHighMem(page))
                return get_highmem_page_buffer(page, ca);
 
@@ -1778,7 +1825,7 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
        pbe = chain_alloc(ca, sizeof(struct pbe));
        if (!pbe) {
                swsusp_free();
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
        pbe->orig_address = page_address(page);
        pbe->address = safe_pages_list;
@@ -1841,7 +1888,10 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
                                return error;
 
                } else if (handle->prev <= nr_meta_pages) {
-                       unpack_orig_pfns(buffer, &copy_bm);
+                       error = unpack_orig_pfns(buffer, &copy_bm);
+                       if (error)
+                               return error;
+
                        if (handle->prev == nr_meta_pages) {
                                error = prepare_image(&orig_bm, &copy_bm);
                                if (error)
@@ -1852,12 +1902,14 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
                                restore_pblist = NULL;
                                handle->buffer = get_buffer(&orig_bm, &ca);
                                handle->sync_read = 0;
-                               if (!handle->buffer)
-                                       return -ENOMEM;
+                               if (IS_ERR(handle->buffer))
+                                       return PTR_ERR(handle->buffer);
                        }
                } else {
                        copy_last_highmem_page();
                        handle->buffer = get_buffer(&orig_bm, &ca);
+                       if (IS_ERR(handle->buffer))
+                               return PTR_ERR(handle->buffer);
                        if (handle->buffer != buffer)
                                handle->sync_read = 0;
                }