Merge git://oak/home/sfr/kernels/iseries/work
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / snapshot.c
index 84e686bdb40bd1e1a75697030a8cda5c3b8e0bfe..4a6dbcefd37875d75e404ae6b5799cec3836a700 100644 (file)
@@ -1,8 +1,7 @@
 /*
- * linux/kernel/power/swsusp.c
+ * linux/kernel/power/snapshot.c
  *
- * This file is to realize architecture-independent
- * machine suspend feature using pretty near only high-level routines
+ * This file provide system snapshot/restore functionality.
  *
  * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
  *
 #include <linux/mm.h>
 #include <linux/suspend.h>
 #include <linux/smp_lock.h>
-#include <linux/file.h>
-#include <linux/utsname.h>
-#include <linux/version.h>
 #include <linux/delay.h>
-#include <linux/reboot.h>
 #include <linux/bitops.h>
-#include <linux/vt_kern.h>
-#include <linux/kbd_kern.h>
-#include <linux/keyboard.h>
 #include <linux/spinlock.h>
-#include <linux/genhd.h>
 #include <linux/kernel.h>
-#include <linux/major.h>
-#include <linux/swap.h>
 #include <linux/pm.h>
 #include <linux/device.h>
-#include <linux/buffer_head.h>
-#include <linux/swapops.h>
 #include <linux/bootmem.h>
 #include <linux/syscalls.h>
 #include <linux/console.h>
 #include <linux/highmem.h>
-#include <linux/bio.h>
-#include <linux/mount.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
-#include <linux/random.h>
-#include <linux/crypto.h>
-#include <asm/scatterlist.h>
-
 #include "power.h"
 
-
-
-
 #ifdef CONFIG_HIGHMEM
 struct highmem_page {
        char *data;
@@ -109,12 +87,9 @@ static int save_highmem_zone(struct zone *zone)
        }
        return 0;
 }
-#endif /* CONFIG_HIGHMEM */
-
 
-static int save_highmem(void)
+int save_highmem(void)
 {
-#ifdef CONFIG_HIGHMEM
        struct zone *zone;
        int res = 0;
 
@@ -125,13 +100,11 @@ static int save_highmem(void)
                if (res)
                        return res;
        }
-#endif
        return 0;
 }
 
 int restore_highmem(void)
 {
-#ifdef CONFIG_HIGHMEM
        printk("swsusp: Restoring Highmem\n");
        while (highmem_copy) {
                struct highmem_page *save = highmem_copy;
@@ -144,10 +117,9 @@ int restore_highmem(void)
                free_page((long) save->data);
                kfree(save);
        }
-#endif
        return 0;
 }
-
+#endif
 
 static int pfn_is_nosave(unsigned long pfn)
 {
@@ -165,10 +137,10 @@ static int pfn_is_nosave(unsigned long pfn)
  *     isn't part of a free chunk of pages.
  */
 
-static int saveable(struct zone * zone, unsigned long * zone_pfn)
+static int saveable(struct zone *zone, unsigned long *zone_pfn)
 {
        unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
-       struct page * page;
+       struct page *page;
 
        if (!pfn_valid(pfn))
                return 0;
@@ -191,9 +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;
@@ -222,7 +193,7 @@ static void copy_data_pages(struct pbe *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;
+                               struct page *page;
                                page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
                                BUG_ON(!pbe);
                                pbe->orig_address = (unsigned long)page_address(page);
@@ -240,7 +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;
 
@@ -273,10 +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)
@@ -293,9 +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));
@@ -303,6 +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.
  *
@@ -316,21 +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 = (struct pbe *)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 = (struct pbe *)alloc_image_page();
+               pbe->next = alloc_image_page(gfp_mask, safe_needed);
        }
        if (!pbe) { /* get_zeroed_page() failed */
                free_pagedir(pblist);
@@ -352,7 +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);
@@ -371,46 +368,49 @@ 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;
+
+       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 nr_pages)
+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;
 }
 
-static int suspend_prepare_image(void)
+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();
@@ -430,11 +430,6 @@ static int suspend_prepare_image(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;
@@ -456,9 +451,3 @@ static int suspend_prepare_image(void)
        printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
        return 0;
 }
-
-
-asmlinkage int swsusp_save(void)
-{
-       return suspend_prepare_image();
-}