1 files changed, 59 insertions, 41 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 42a628704398..4a6dbcefd378 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -88,8 +88,7 @@ static int save_highmem_zone(struct zone *zone)
         return 0;
 }
 
-
-static int save_highmem(void)
+int save_highmem(void)
 {
         struct zone *zone;
         int res = 0;
@@ -120,11 +119,7 @@ int restore_highmem(void)
         }
         return 0;
 }
-#else
-static int save_highmem(void) { return 0; }
-int restore_highmem(void) { return 0; }
-#endif /* CONFIG_HIGHMEM */
-
+#endif
 
 static int pfn_is_nosave(unsigned long pfn)
 {
@@ -168,9 +163,8 @@ static unsigned count_data_pages(void)
 {
         struct zone *zone;
         unsigned long zone_pfn;
-        unsigned n;
+        unsigned int n = 0;
 
-        n = 0;
         for_each_zone (zone) {
                 if (is_highmem(zone))
                         continue;
@@ -217,7 +211,7 @@ static void copy_data_pages(struct pbe *pblist)
  *      free_pagedir - free pages allocated with alloc_pagedir()
  */
 
-static void free_pagedir(struct pbe *pblist)
+void free_pagedir(struct pbe *pblist)
 {
         struct pbe *pbe;
 
@@ -250,10 +244,10 @@ static inline void fill_pb_page(struct pbe *pbpage)
  *      of memory pages allocated with alloc_pagedir()
  */
 
-void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
+void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
 {
         struct pbe *pbpage, *p;
-        unsigned num = PBES_PER_PAGE;
+        unsigned int num = PBES_PER_PAGE;
 
         for_each_pb_page (pbpage, pblist) {
                 if (num >= nr_pages)
@@ -270,9 +264,30 @@ void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
         pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
 }
 
-static void *alloc_image_page(void)
+/**
+ *      @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.
+ *
+ *      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
+ */
+
+static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
 {
-        void *res = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
+        void *res;
+
+        if (safe_needed)
+                do {
+                        res = (void *)get_zeroed_page(gfp_mask);
+                        if (res && PageNosaveFree(virt_to_page(res)))
+                                /* This is for swsusp_free() */
+                                SetPageNosave(virt_to_page(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));
@@ -280,6 +295,11 @@ static void *alloc_image_page(void)
         return res;
 }
 
+unsigned long get_safe_page(gfp_t gfp_mask)
+{
+        return (unsigned long)alloc_image_page(gfp_mask, 1);
+}
+
 /**
  *      alloc_pagedir - Allocate the page directory.
  *
@@ -293,21 +313,21 @@ static void *alloc_image_page(void)
  *      On each page we set up a list of struct_pbe elements.
  */
 
-struct pbe *alloc_pagedir(unsigned nr_pages)
+struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed)
 {
-        unsigned num;
+        unsigned int num;
         struct pbe *pblist, *pbe;
 
         if (!nr_pages)
                 return NULL;
 
         pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
-        pblist = alloc_image_page();
+        pblist = alloc_image_page(gfp_mask, safe_needed);
         /* FIXME: rewrite this ugly loop */
         for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
                         pbe = pbe->next, num += PBES_PER_PAGE) {
                 pbe += PB_PAGE_SKIP;
-                pbe->next = alloc_image_page();
+                pbe->next = alloc_image_page(gfp_mask, safe_needed);
         }
         if (!pbe) { /* get_zeroed_page() failed */
                 free_pagedir(pblist);
@@ -329,7 +349,7 @@ void swsusp_free(void)
         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;
+                                struct page *page;
                                 page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
                                 if (PageNosave(page) && PageNosaveFree(page)) {
                                         ClearPageNosave(page);
@@ -348,31 +368,39 @@ void swsusp_free(void)
  *      free pages.
  */
 
-static int enough_free_mem(unsigned nr_pages)
+static int enough_free_mem(unsigned int nr_pages)
 {
         pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
         return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
                 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
 }
 
+int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed)
+{
+        struct pbe *p;
 
-static struct pbe *swsusp_alloc(unsigned nr_pages)
+        for_each_pbe (p, pblist) {
+                p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed);
+                if (!p->address)
+                        return -ENOMEM;
+        }
+        return 0;
+}
+
+static struct pbe *swsusp_alloc(unsigned int nr_pages)
 {
-        struct pbe *pblist, *p;
+        struct pbe *pblist;
 
-        if (!(pblist = alloc_pagedir(nr_pages))) {
+        if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) {
                 printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
                 return NULL;
         }
         create_pbe_list(pblist, nr_pages);
 
-        for_each_pbe (p, pblist) {
-                p->address = (unsigned long)alloc_image_page();
-                if (!p->address) {
-                        printk(KERN_ERR "suspend: Allocating image pages failed.\n");
-                        swsusp_free();
-                        return NULL;
-                }
+        if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) {
+                printk(KERN_ERR "suspend: Allocating image pages failed.\n");
+                swsusp_free();
+                return NULL;
         }
 
         return pblist;
@@ -380,14 +408,9 @@ static struct pbe *swsusp_alloc(unsigned nr_pages)
 
 asmlinkage int swsusp_save(void)
 {
-        unsigned nr_pages;
+        unsigned int nr_pages;
 
         pr_debug("swsusp: critical section: \n");
-        if (save_highmem()) {
-                printk(KERN_CRIT "swsusp: Not enough free pages for highmem\n");
-                restore_highmem();
-                return -ENOMEM;
-        }
 
         drain_local_pages();
         nr_pages = count_data_pages();
@@ -407,11 +430,6 @@ asmlinkage int swsusp_save(void)
                 return -ENOMEM;
         }
 
-        if (!enough_swap(nr_pages)) {
-                printk(KERN_ERR "swsusp: Not enough free swap\n");
-                return -ENOSPC;
-        }
-
         pagedir_nosave = swsusp_alloc(nr_pages);
         if (!pagedir_nosave)
                 return -ENOMEM;