1 files changed, 536 insertions, 66 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index d0d691f976d8..852e0df41719 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -211,6 +211,467 @@ static inline void free_image_page(void *addr, int clear_nosave_free)
 	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
  */
@@ -276,32 +737,38 @@ static inline void copy_data_page(long *dst, long *src)
 		*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);
 }
 
 /**
@@ -447,37 +914,43 @@ static int enough_free_mem(unsigned int nr_pages)
 		(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;
@@ -498,15 +971,14 @@ asmlinkage int swsusp_save(void)
 		return -ENOMEM;
 	}
 
-	restore_pblist = swsusp_alloc(nr_pages);
-	if (!restore_pblist)
+	if (swsusp_alloc(&orig_bm, &copy_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(&copy_bm, &orig_bm);
 
 	/*
 	 * End of critical section. From now on, we can write to memory,
@@ -535,22 +1007,23 @@ static void init_header(struct swsusp_info *info)
 }
 
 /**
- *	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;
 }
 
 /**
@@ -579,6 +1052,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 {
 	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);
@@ -588,16 +1062,17 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 	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(&copy_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(&copy_bm);
+
+			handle->buffer = page_address(pfn_to_page(pfn));
 		}
 		handle->prev = handle->cur;
 	}
@@ -736,12 +1211,7 @@ static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
  *	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)
 {
@@ -763,9 +1233,9 @@ 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;