mm: introduce for_each_populated_zone() macro
[safe/jmp/linux-2.6] / kernel / power / snapshot.c
index 955c8cc..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.
  *
@@ -233,7 +228,7 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
 #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 long *data;    /* bitmap representing pages */
@@ -244,24 +239,15 @@ static inline unsigned long bm_block_bits(struct bm_block *bb)
        return bb->end_pfn - bb->start_pfn;
 }
 
-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 */
-};
-
 /* strcut bm_position is used for browsing memory bitmaps */
 
 struct bm_position {
-       struct zone_bitmap *zone_bm;
        struct bm_block *block;
        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
@@ -273,11 +259,7 @@ struct memory_bitmap {
 
 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;
+       bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook);
        bm->cur.bit = 0;
 }
 
@@ -285,151 +267,181 @@ 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;
 
-               zbm->next = zbmlist;
-               zbmlist = zbm;
+                       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;
+               }
+
+               /* 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;
-                               nr -= BM_BITS_PER_BLOCK;
+                               pages -= BM_BITS_PER_BLOCK;
                        } else {
                                /* This is executed only once in the loop */
-                               pfn += nr;
+                               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);
 }
 
 /**
@@ -437,38 +449,33 @@ 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 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;
-
-                       if (!zone_bm)
-                               return -EFAULT;
-               }
-               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;
+       bm->cur.bit = pfn + 1;
        *bit_nr = pfn;
        *addr = bb->data;
        return 0;
@@ -538,29 +545,21 @@ static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
 
 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
 {
-       struct zone_bitmap *zone_bm;
        struct bm_block *bb;
        int bit;
 
+       bb = bm->cur.block;
        do {
-               bb = bm->cur.block;
-               do {
-                       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 = bb->next;
-                       bm->cur.block = bb;
-                       bm->cur.bit = 0;
-               } 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;
-                       bm->cur.bit = 0;
-               }
-       } 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;
 
@@ -802,8 +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;
@@ -816,8 +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;
 
@@ -825,6 +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));
 
@@ -854,13 +854,16 @@ 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 void *saveable_highmem_page(struct zone *z, unsigned long p)
+{
+       return NULL;
+}
 #endif /* CONFIG_HIGHMEM */
 
 /**
@@ -871,8 +874,7 @@ static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
  *     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;
 
@@ -880,6 +882,8 @@ 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));
 
@@ -911,7 +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;
@@ -952,7 +956,7 @@ 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 void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
@@ -974,7 +978,7 @@ static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
                         * data modified by kmap_atomic()
                         */
                        safe_copy_page(buffer, s_page);
-                       dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
+                       dst = kmap_atomic(d_page, KM_USER0);
                        memcpy(dst, buffer, PAGE_SIZE);
                        kunmap_atomic(dst, KM_USER0);
                } else {
@@ -983,7 +987,7 @@ static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
        }
 }
 #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)
 {