X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Fpower%2Fsnapshot.c;h=81fe8de9e6040ac68b3e91ff27d25d3dbf91b2dd;hb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;hp=3eeedbb13b7864d525c6740a99156b433e3b6a51;hpb=4e76c8a9fa413ccc09d3f7f664183dcce3555d57;p=linux-2.6.git

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 3eeedbb13..81fe8de9e 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -150,9 +150,13 @@ int restore_highmem(void)
 	}
 	return 0;
 }
+#else
+static inline unsigned int count_highmem_pages(void) {return 0;}
+static inline int save_highmem(void) {return 0;}
+static inline int restore_highmem(void) {return 0;}
 #endif
 
-static int pfn_is_nosave(unsigned long pfn)
+static inline int pfn_is_nosave(unsigned long pfn)
 {
 	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
 	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
@@ -163,43 +167,43 @@ static int pfn_is_nosave(unsigned long pfn)
  *	saveable - Determine whether a page should be cloned or not.
  *	@pfn:	The page
  *
- *	We save a page if it's Reserved, and not in the range of pages
- *	statically defined as 'unsaveable', or if it isn't reserved, and
- *	isn't part of a free chunk of pages.
+ *	We save a page if it isn't Nosave, and is not in the range of pages
+ *	statically defined as 'unsaveable', and it
+ *	isn't a part of a free chunk of pages.
  */
 
-static int saveable(struct zone *zone, unsigned long *zone_pfn)
+static struct page *saveable_page(unsigned long pfn)
 {
-	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
 	struct page *page;
 
 	if (!pfn_valid(pfn))
-		return 0;
+		return NULL;
 
 	page = pfn_to_page(pfn);
-	BUG_ON(PageReserved(page) && PageNosave(page));
+
 	if (PageNosave(page))
-		return 0;
+		return NULL;
 	if (PageReserved(page) && pfn_is_nosave(pfn))
-		return 0;
+		return NULL;
 	if (PageNosaveFree(page))
-		return 0;
+		return NULL;
 
-	return 1;
+	return page;
 }
 
 unsigned int count_data_pages(void)
 {
 	struct zone *zone;
-	unsigned long zone_pfn;
+	unsigned long pfn, max_zone_pfn;
 	unsigned int n = 0;
 
 	for_each_zone (zone) {
 		if (is_highmem(zone))
 			continue;
 		mark_free_pages(zone);
-		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
-			n += saveable(zone, &zone_pfn);
+		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			n += !!saveable_page(pfn);
 	}
 	return n;
 }
@@ -207,7 +211,7 @@ unsigned int count_data_pages(void)
 static void copy_data_pages(struct pbe *pblist)
 {
 	struct zone *zone;
-	unsigned long zone_pfn;
+	unsigned long pfn, max_zone_pfn;
 	struct pbe *pbe, *p;
 
 	pbe = pblist;
@@ -220,14 +224,21 @@ static void copy_data_pages(struct pbe *pblist)
 			SetPageNosaveFree(virt_to_page(p));
 		for_each_pbe (p, pblist)
 			SetPageNosaveFree(virt_to_page(p->address));
-		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
-			if (saveable(zone, &zone_pfn)) {
-				struct page *page;
-				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
+		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) {
+				long *src, *dst;
+				int n;
+
 				BUG_ON(!pbe);
 				pbe->orig_address = (unsigned long)page_address(page);
-				/* copy_page is not usable for copying task structs. */
-				memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
+				/* copy_page and memcpy are not usable for copying task structs. */
+				dst = (long *)pbe->address;
+				src = (long *)pbe->orig_address;
+				for (n = PAGE_SIZE / sizeof(long); n; n--)
+					*dst++ = *src++;
 				pbe = pbe->next;
 			}
 		}
@@ -293,62 +304,29 @@ static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
 	}
 }
 
-/**
- *	On resume it is necessary to trace and eventually free the unsafe
- *	pages that have been allocated, because they are needed for I/O
- *	(on x86-64 we likely will "eat" these pages once again while
- *	creating the temporary page translation tables)
- */
-
-struct eaten_page {
-	struct eaten_page *next;
-	char padding[PAGE_SIZE - sizeof(void *)];
-};
-
-static struct eaten_page *eaten_pages = NULL;
-
-static void release_eaten_pages(void)
-{
-	struct eaten_page *p, *q;
-
-	p = eaten_pages;
-	while (p) {
-		q = p->next;
-		/* We don't want swsusp_free() to free this page again */
-		ClearPageNosave(virt_to_page(p));
-		free_page((unsigned long)p);
-		p = q;
-	}
-	eaten_pages = NULL;
-}
+static unsigned int unsafe_pages;
 
 /**
  *	@safe_needed - on resume, for storing the PBE list and the image,
  *	we can only use memory pages that do not conflict with the pages
- *	which had been used before suspend.
+ *	used before suspend.
  *
  *	The unsafe pages are marked with the PG_nosave_free flag
- *
- *	Allocated but unusable (ie eaten) memory pages should be marked
- *	so that swsusp_free() can release them
+ *	and we count them using unsafe_pages
  */
 
-static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
+static void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
 {
 	void *res;
 
+	res = (void *)get_zeroed_page(gfp_mask);
 	if (safe_needed)
-		do {
+		while (res && PageNosaveFree(virt_to_page(res))) {
+			/* The page is unsafe, mark it for swsusp_free() */
+			SetPageNosave(virt_to_page(res));
+			unsafe_pages++;
 			res = (void *)get_zeroed_page(gfp_mask);
-			if (res && PageNosaveFree(virt_to_page(res))) {
-				/* This is for swsusp_free() */
-				SetPageNosave(virt_to_page(res));
-				((struct eaten_page *)res)->next = eaten_pages;
-				eaten_pages = res;
-			}
-		} while (res && PageNosaveFree(virt_to_page(res)));
-	else
-		res = (void *)get_zeroed_page(gfp_mask);
+		}
 	if (res) {
 		SetPageNosave(virt_to_page(res));
 		SetPageNosaveFree(virt_to_page(res));
@@ -374,7 +352,8 @@ unsigned long get_safe_page(gfp_t gfp_mask)
  *	On each page we set up a list of struct_pbe elements.
  */
 
-struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed)
+static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask,
+				 int safe_needed)
 {
 	unsigned int num;
 	struct pbe *pblist, *pbe;
@@ -405,13 +384,14 @@ struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed
 void swsusp_free(void)
 {
 	struct zone *zone;
-	unsigned long zone_pfn;
+	unsigned long pfn, max_zone_pfn;
 
 	for_each_zone(zone) {
-		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
-			if (pfn_valid(zone_pfn + zone->zone_start_pfn)) {
-				struct page *page;
-				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
+		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			if (pfn_valid(pfn)) {
+				struct page *page = pfn_to_page(pfn);
+
 				if (PageNosave(page) && PageNosaveFree(page)) {
 					ClearPageNosave(page);
 					ClearPageNosaveFree(page);
@@ -575,7 +555,7 @@ static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pb
 
 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 {
-	if (handle->page > nr_meta_pages + nr_copy_pages)
+	if (handle->cur > nr_meta_pages + nr_copy_pages)
 		return 0;
 	if (!buffer) {
 		/* This makes the buffer be freed by swsusp_free() */
@@ -588,8 +568,8 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 		handle->buffer = buffer;
 		handle->pbe = pagedir_nosave;
 	}
-	if (handle->prev < handle->page) {
-		if (handle->page <= nr_meta_pages) {
+	if (handle->prev < handle->cur) {
+		if (handle->cur <= nr_meta_pages) {
 			handle->pbe = pack_orig_addresses(buffer, handle->pbe);
 			if (!handle->pbe)
 				handle->pbe = pagedir_nosave;
@@ -597,15 +577,15 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 			handle->buffer = (void *)handle->pbe->address;
 			handle->pbe = handle->pbe->next;
 		}
-		handle->prev = handle->page;
+		handle->prev = handle->cur;
 	}
-	handle->buf_offset = handle->page_offset;
-	if (handle->page_offset + count >= PAGE_SIZE) {
-		count = PAGE_SIZE - handle->page_offset;
-		handle->page_offset = 0;
-		handle->page++;
+	handle->buf_offset = handle->cur_offset;
+	if (handle->cur_offset + count >= PAGE_SIZE) {
+		count = PAGE_SIZE - handle->cur_offset;
+		handle->cur_offset = 0;
+		handle->cur++;
 	} else {
-		handle->page_offset += count;
+		handle->cur_offset += count;
 	}
 	handle->offset += count;
 	return count;
@@ -620,7 +600,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 static int mark_unsafe_pages(struct pbe *pblist)
 {
 	struct zone *zone;
-	unsigned long zone_pfn;
+	unsigned long pfn, max_zone_pfn;
 	struct pbe *p;
 
 	if (!pblist) /* a sanity check */
@@ -628,10 +608,10 @@ static int mark_unsafe_pages(struct pbe *pblist)
 
 	/* Clear page flags */
 	for_each_zone (zone) {
-		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
-			if (pfn_valid(zone_pfn + zone->zone_start_pfn))
-				ClearPageNosaveFree(pfn_to_page(zone_pfn +
-					zone->zone_start_pfn));
+		max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			if (pfn_valid(pfn))
+				ClearPageNosaveFree(pfn_to_page(pfn));
 	}
 
 	/* Mark orig addresses */
@@ -642,6 +622,8 @@ static int mark_unsafe_pages(struct pbe *pblist)
 			return -EFAULT;
 	}
 
+	unsafe_pages = 0;
+
 	return 0;
 }
 
@@ -719,42 +701,99 @@ static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
 }
 
 /**
- *	create_image - use metadata contained in the PBE list
+ *	prepare_image - use metadata contained in the PBE list
  *	pointed to by pagedir_nosave to mark the pages that will
  *	be overwritten in the process of restoring the system
- *	memory state from the image and allocate memory for
- *	the image avoiding these pages
+ *	memory state from the image ("unsafe" pages) and allocate
+ *	memory for the image
+ *
+ *	The idea is to allocate the PBE list first and then
+ *	allocate as many pages as it's needed for the image data,
+ *	but not to assign these pages to the PBEs initially.
+ *	Instead, we just mark them as allocated and create a list
+ *	of "safe" which will be used later
  */
 
-static int create_image(struct snapshot_handle *handle)
+struct safe_page {
+	struct safe_page *next;
+	char padding[PAGE_SIZE - sizeof(void *)];
+};
+
+static struct safe_page *safe_pages;
+
+static int prepare_image(struct snapshot_handle *handle)
 {
 	int error = 0;
-	struct pbe *p, *pblist;
+	unsigned int nr_pages = nr_copy_pages;
+	struct pbe *p, *pblist = NULL;
 
 	p = pagedir_nosave;
 	error = mark_unsafe_pages(p);
 	if (!error) {
-		pblist = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1);
+		pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1);
 		if (pblist)
 			copy_page_backup_list(pblist, p);
 		free_pagedir(p, 0);
 		if (!pblist)
 			error = -ENOMEM;
 	}
-	if (!error)
-		error = alloc_data_pages(pblist, GFP_ATOMIC, 1);
+	safe_pages = NULL;
+	if (!error && nr_pages > unsafe_pages) {
+		nr_pages -= unsafe_pages;
+		while (nr_pages--) {
+			struct safe_page *ptr;
+
+			ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC);
+			if (!ptr) {
+				error = -ENOMEM;
+				break;
+			}
+			if (!PageNosaveFree(virt_to_page(ptr))) {
+				/* The page is "safe", add it to the list */
+				ptr->next = safe_pages;
+				safe_pages = ptr;
+			}
+			/* Mark the page as allocated */
+			SetPageNosave(virt_to_page(ptr));
+			SetPageNosaveFree(virt_to_page(ptr));
+		}
+	}
 	if (!error) {
-		release_eaten_pages();
 		pagedir_nosave = pblist;
 	} else {
-		pagedir_nosave = NULL;
 		handle->pbe = NULL;
-		nr_copy_pages = 0;
-		nr_meta_pages = 0;
+		swsusp_free();
 	}
 	return error;
 }
 
+static void *get_buffer(struct snapshot_handle *handle)
+{
+	struct pbe *pbe = handle->pbe, *last = handle->last_pbe;
+	struct page *page = virt_to_page(pbe->orig_address);
+
+	if (PageNosave(page) && PageNosaveFree(page)) {
+		/*
+		 * We have allocated the "original" page frame and we can
+		 * use it directly to store the read page
+		 */
+		pbe->address = 0;
+		if (last && last->next)
+			last->next = NULL;
+		return (void *)pbe->orig_address;
+	}
+	/*
+	 * The "original" page frame has not been allocated and we have to
+	 * use a "safe" page frame to store the read page
+	 */
+	pbe->address = (unsigned long)safe_pages;
+	safe_pages = safe_pages->next;
+	if (last)
+		last->next = pbe;
+	handle->last_pbe = pbe;
+	return (void *)pbe->address;
+}
+
 /**
  *	snapshot_write_next - used for writing the system memory snapshot.
  *
@@ -781,7 +820,7 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 {
 	int error = 0;
 
-	if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages)
+	if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
 		return 0;
 	if (!buffer) {
 		/* This makes the buffer be freed by swsusp_free() */
@@ -791,33 +830,39 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 	}
 	if (!handle->offset)
 		handle->buffer = buffer;
-	if (handle->prev < handle->page) {
+	handle->sync_read = 1;
+	if (handle->prev < handle->cur) {
 		if (!handle->prev) {
-			error = load_header(handle, (struct swsusp_info *)buffer);
+			error = load_header(handle,
+					(struct swsusp_info *)buffer);
 			if (error)
 				return error;
 		} else if (handle->prev <= nr_meta_pages) {
-			handle->pbe = unpack_orig_addresses(buffer, handle->pbe);
+			handle->pbe = unpack_orig_addresses(buffer,
+							handle->pbe);
 			if (!handle->pbe) {
-				error = create_image(handle);
+				error = prepare_image(handle);
 				if (error)
 					return error;
 				handle->pbe = pagedir_nosave;
-				handle->buffer = (void *)handle->pbe->address;
+				handle->last_pbe = NULL;
+				handle->buffer = get_buffer(handle);
+				handle->sync_read = 0;
 			}
 		} else {
 			handle->pbe = handle->pbe->next;
-			handle->buffer = (void *)handle->pbe->address;
+			handle->buffer = get_buffer(handle);
+			handle->sync_read = 0;
 		}
-		handle->prev = handle->page;
+		handle->prev = handle->cur;
 	}
-	handle->buf_offset = handle->page_offset;
-	if (handle->page_offset + count >= PAGE_SIZE) {
-		count = PAGE_SIZE - handle->page_offset;
-		handle->page_offset = 0;
-		handle->page++;
+	handle->buf_offset = handle->cur_offset;
+	if (handle->cur_offset + count >= PAGE_SIZE) {
+		count = PAGE_SIZE - handle->cur_offset;
+		handle->cur_offset = 0;
+		handle->cur++;
 	} else {
-		handle->page_offset += count;
+		handle->cur_offset += count;
 	}
 	handle->offset += count;
 	return count;
@@ -826,5 +871,5 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 int snapshot_image_loaded(struct snapshot_handle *handle)
 {
 	return !(!handle->pbe || handle->pbe->next || !nr_copy_pages ||
-		handle->page <= nr_meta_pages + nr_copy_pages);
+		handle->cur <= nr_meta_pages + nr_copy_pages);
 }