free_page((unsigned long)addr);
}
+/* struct linked_page is used to build chains of pages */
+
+#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
+
+struct linked_page {
+ struct linked_page *next;
+ char data[LINKED_PAGE_DATA_SIZE];
+} __attribute__((packed));
+
+static inline void
+free_list_of_pages(struct linked_page *list, int clear_page_nosave)
+{
+ while (list) {
+ struct linked_page *lp = list->next;
+
+ free_image_page(list, clear_page_nosave);
+ list = lp;
+ }
+}
+
+/**
+ * struct chain_allocator is used for allocating small objects out of
+ * a linked list of pages called 'the chain'.
+ *
+ * The chain grows each time when there is no room for a new object in
+ * the current page. The allocated objects cannot be freed individually.
+ * It is only possible to free them all at once, by freeing the entire
+ * chain.
+ *
+ * NOTE: The chain allocator may be inefficient if the allocated objects
+ * are not much smaller than PAGE_SIZE.
+ */
+
+struct chain_allocator {
+ struct linked_page *chain; /* the chain */
+ unsigned int used_space; /* total size of objects allocated out
+ * of the current page
+ */
+ gfp_t gfp_mask; /* mask for allocating pages */
+ int safe_needed; /* if set, only "safe" pages are allocated */
+};
+
+static void
+chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
+{
+ ca->chain = NULL;
+ ca->used_space = LINKED_PAGE_DATA_SIZE;
+ ca->gfp_mask = gfp_mask;
+ ca->safe_needed = safe_needed;
+}
+
+static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
+{
+ void *ret;
+
+ if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
+ struct linked_page *lp;
+
+ lp = alloc_image_page(ca->gfp_mask, ca->safe_needed);
+ if (!lp)
+ return NULL;
+
+ lp->next = ca->chain;
+ ca->chain = lp;
+ ca->used_space = 0;
+ }
+ ret = ca->chain->data + ca->used_space;
+ ca->used_space += 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.
+ *
+ * Memory bitmap is a structure consiting of many linked lists of
+ * 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.
+ *
+ * struct memory_bitmap contains a pointer to the main list of zone
+ * bitmap objects, a struct bm_position used for browsing the bitmap,
+ * and a pointer to the list of pages used for allocating all of the
+ * zone bitmap objects and bitmap block objects.
+ *
+ * NOTE: It has to be possible to lay out the bitmap in memory
+ * using only allocations of order 0. Additionally, the bitmap is
+ * designed to work with arbitrary number of zones (this is over the
+ * top for now, but let's avoid making unnecessary assumptions ;-).
+ *
+ * struct zone_bitmap contains a pointer to a list of bitmap block
+ * objects and a pointer to the bitmap block object that has been
+ * most recently used for setting bits. Additionally, it contains the
+ * 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.
+ *
+ * NOTE: Memory bitmaps are used for two types of operations only:
+ * "set a bit" and "find the next bit set". Moreover, the searching
+ * is always carried out after all of the "set a bit" operations
+ * on given bitmap.
+ */
+
+#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 */
+ 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 */
+};
+
+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 chunk;
+ int bit;
+};
+
+struct memory_bitmap {
+ struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */
+ struct linked_page *p_list; /* list of pages used to store zone
+ * bitmap objects and bitmap block
+ * objects
+ */
+ struct bm_position cur; /* most recently used bit position */
+};
+
+/* 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);
+}
+
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
+
+/**
+ * create_bm_block_list - create a list of block bitmap objects
+ */
+
+static inline struct bm_block *
+create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
+{
+ struct bm_block *bblist = NULL;
+
+ 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 bblist;
+}
+
+/**
+ * create_zone_bm_list - create a list of zone bitmap objects
+ */
+
+static inline struct zone_bitmap *
+create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
+{
+ struct zone_bitmap *zbmlist = NULL;
+
+ while (nr_zones-- > 0) {
+ struct zone_bitmap *zbm;
+
+ zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
+ if (!zbm)
+ return NULL;
+
+ zbm->next = zbmlist;
+ zbmlist = zbm;
+ }
+ return zbmlist;
+}
+
+/**
+ * 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;
+
+ chain_init(&ca, gfp_mask, safe_needed);
+
+ /* Compute the number of zones */
+ nr = 0;
+ for_each_zone (zone)
+ if (populated_zone(zone) && !is_highmem(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;
+
+ if (!populated_zone(zone) || is_highmem(zone))
+ continue;
+
+ 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;
+
+ nr = zone->spanned_pages;
+ pfn = zone->zone_start_pfn;
+ /* Initialize the bitmap block objects */
+ while (bb) {
+ unsigned long *ptr;
+
+ ptr = alloc_image_page(gfp_mask, safe_needed);
+ bb->data = ptr;
+ if (!ptr)
+ goto Free;
+
+ bb->start_pfn = pfn;
+ if (nr >= BM_BITS_PER_BLOCK) {
+ pfn += BM_BITS_PER_BLOCK;
+ bb->size = BM_CHUNKS_PER_BLOCK;
+ nr -= 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);
+ }
+ bb->end_pfn = pfn;
+ bb = bb->next;
+ }
+ zone_bm = zone_bm->next;
+ }
+ bm->p_list = ca.chain;
+ memory_bm_position_reset(bm);
+ return 0;
+
+Free:
+ bm->p_list = ca.chain;
+ memory_bm_free(bm, PG_UNSAFE_CLEAR);
+ return -ENOMEM;
+}
+
+/**
+ * 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;
+
+ /* Free the list of bit blocks for each zone_bitmap object */
+ zone_bm = bm->zone_bm_list;
+ while (zone_bm) {
+ struct bm_block *bb;
+
+ 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;
+}
+
+/**
+ * memory_bm_set_bit - set the bit in the bitmap @bm that corresponds
+ * to given pfn. The cur_zone_bm member of @bm and the cur_block member
+ * of @bm->cur_zone_bm are updated.
+ *
+ * If the bit cannot be set, the function returns -EINVAL .
+ */
+
+static int
+memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
+{
+ 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 (unlikely(!zone_bm))
+ return -EINVAL;
+ }
+ bm->cur.zone_bm = zone_bm;
+ }
+ /* Check if the pfn corresponds to the current bitmap block */
+ bb = zone_bm->cur_block;
+ if (pfn < bb->start_pfn)
+ bb = zone_bm->bm_blocks;
+
+ while (pfn >= bb->end_pfn) {
+ bb = bb->next;
+ if (unlikely(!bb))
+ return -EINVAL;
+ }
+ zone_bm->cur_block = bb;
+ pfn -= bb->start_pfn;
+ set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK);
+ return 0;
+}
+
+/* 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)
+{
+ bit++;
+ while (bit < BM_BITS_PER_CHUNK) {
+ if (test_bit(bit, chunk_p))
+ return bit;
+
+ bit++;
+ }
+ return -1;
+}
+
+/* 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)
+{
+ n++;
+ while (n < bb->size) {
+ if (bb->data[n])
+ return n;
+
+ n++;
+ }
+ return -1;
+}
+
+/**
+ * memory_bm_next_pfn - find the pfn that corresponds to the next set bit
+ * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
+ * returned.
+ *
+ * It is required to run memory_bm_position_reset() before the first call to
+ * this function.
+ */
+
+static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
+{
+ struct zone_bitmap *zone_bm;
+ struct bm_block *bb;
+ int chunk;
+ int bit;
+
+ 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);
+ 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;
+}
+
+/**
+ * snapshot_additional_pages - estimate the number of additional pages
+ * be needed for setting up the suspend image data structures for given
+ * zone (usually the returned value is greater than the exact number)
+ */
+
+unsigned int snapshot_additional_pages(struct zone *zone)
+{
+ unsigned int res;
+
+ res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
+ res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
+ return res;
+}
+
/**
* pfn_is_nosave - check if given pfn is in the 'nosave' section
*/
*dst++ = *src++;
}
-static void copy_data_pages(struct pbe *pblist)
+static void
+copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
{
struct zone *zone;
- unsigned long pfn, max_zone_pfn;
- struct pbe *pbe;
+ unsigned long pfn;
- pbe = pblist;
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++) {
- struct page *page = saveable_page(pfn);
-
- if (page) {
- void *ptr = page_address(page);
-
- BUG_ON(!pbe);
- copy_data_page((void *)pbe->address, ptr);
- pbe->orig_address = (unsigned long)ptr;
- pbe = pbe->next;
- }
- }
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+ if (saveable_page(pfn))
+ memory_bm_set_bit(orig_bm, pfn);
}
- BUG_ON(pbe);
+ 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);
+ }
+ } while (pfn != BM_END_OF_MAP);
}
/**
(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
}
-static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed)
+static int
+swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm,
+ unsigned int nr_pages)
{
- struct pbe *p;
+ int error;
- for_each_pbe (p, pblist) {
- p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed);
- if (!p->address)
- return -ENOMEM;
- }
- return 0;
-}
+ error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+ if (error)
+ goto Free;
-static struct pbe *swsusp_alloc(unsigned int nr_pages)
-{
- struct pbe *pblist;
+ error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+ if (error)
+ goto Free;
- pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, PG_ANY);
- if (!pblist) {
- printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
- return NULL;
- }
+ while (nr_pages-- > 0) {
+ struct page *page = alloc_page(GFP_ATOMIC | __GFP_COLD);
+ if (!page)
+ goto Free;
- if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, PG_ANY)) {
- printk(KERN_ERR "suspend: Allocating image pages failed.\n");
- swsusp_free();
- return NULL;
+ SetPageNosave(page);
+ SetPageNosaveFree(page);
+ memory_bm_set_bit(copy_bm, page_to_pfn(page));
}
+ return 0;
- return pblist;
+Free:
+ swsusp_free();
+ return -ENOMEM;
}
+/* Memory bitmap used for marking saveable pages */
+static struct memory_bitmap orig_bm;
+/* Memory bitmap used for marking allocated pages that will contain the copies
+ * of saveable pages
+ */
+static struct memory_bitmap copy_bm;
+
asmlinkage int swsusp_save(void)
{
unsigned int nr_pages;
return -ENOMEM;
}
- restore_pblist = swsusp_alloc(nr_pages);
- if (!restore_pblist)
+ if (swsusp_alloc(&orig_bm, ©_bm, nr_pages))
return -ENOMEM;
/* During allocating of suspend pagedir, new cold pages may appear.
* Kill them.
*/
drain_local_pages();
- copy_data_pages(restore_pblist);
+ copy_data_pages(©_bm, &orig_bm);
/*
* End of critical section. From now on, we can write to memory,
}
/**
- * pack_orig_addresses - the .orig_address fields of the PBEs from the
- * list starting at @pbe are stored in the array @buf[] (1 page)
+ * pack_addresses - the addresses corresponding to pfns found in the
+ * bitmap @bm are stored in the array @buf[] (1 page)
*/
-static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe)
+static inline void
+pack_addresses(unsigned long *buf, struct memory_bitmap *bm)
{
int j;
- for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
- buf[j] = pbe->orig_address;
- pbe = pbe->next;
+ for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+ unsigned long pfn = memory_bm_next_pfn(bm);
+
+ if (unlikely(pfn == BM_END_OF_MAP))
+ break;
+
+ buf[j] = (unsigned long)page_address(pfn_to_page(pfn));
}
- if (!pbe)
- for (; j < PAGE_SIZE / sizeof(long); j++)
- buf[j] = 0;
- return pbe;
}
/**
{
if (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) {
init_header((struct swsusp_info *)buffer);
handle->buffer = buffer;
- handle->pbe = restore_pblist;
+ memory_bm_position_reset(&orig_bm);
+ memory_bm_position_reset(©_bm);
}
if (handle->prev < handle->cur) {
if (handle->cur <= nr_meta_pages) {
- handle->pbe = pack_orig_addresses(buffer, handle->pbe);
- if (!handle->pbe)
- handle->pbe = restore_pblist;
+ memset(buffer, 0, PAGE_SIZE);
+ pack_addresses(buffer, &orig_bm);
} else {
- handle->buffer = (void *)handle->pbe->address;
- handle->pbe = handle->pbe->next;
+ unsigned long pfn = memory_bm_next_pfn(©_bm);
+
+ handle->buffer = page_address(pfn_to_page(pfn));
}
handle->prev = handle->cur;
}
* of "safe" which will be used later
*/
-struct safe_page {
- struct safe_page *next;
- char padding[PAGE_SIZE - sizeof(void *)];
-};
-
-static struct safe_page *safe_pages;
+static struct linked_page *safe_pages;
static int prepare_image(struct snapshot_handle *handle)
{
if (!error && nr_pages > unsafe_pages) {
nr_pages -= unsafe_pages;
while (nr_pages--) {
- struct safe_page *ptr;
+ struct linked_page *ptr;
- ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC);
+ ptr = (void *)get_zeroed_page(GFP_ATOMIC);
if (!ptr) {
error = -ENOMEM;
break;
projects / openwrt / staging / blogic.git / commitdiff