[PATCH] swsusp: reduce the use of global variables

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 39 insertions, 39 deletions

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 0f0a7f306b0d..03916cf3ff02 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -187,37 +187,38 @@ static int saveable(struct zone * zone, unsigned long * zone_pfn)
         return 1;
 }
 
-static void count_data_pages(void)
+static unsigned count_data_pages(void)
 {
         struct zone *zone;
         unsigned long zone_pfn;
+        unsigned n;
 
-        nr_copy_pages = 0;
-
+        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)
-                        nr_copy_pages += saveable(zone, &zone_pfn);
+                        n += saveable(zone, &zone_pfn);
         }
+        return n;
 }
 
-static void copy_data_pages(void)
+static void copy_data_pages(struct pbe *pblist)
 {
         struct zone *zone;
         unsigned long zone_pfn;
-        struct pbe *pbe = pagedir_nosave, *p;
+        struct pbe *pbe, *p;
 
-        pr_debug("copy_data_pages(): pages to copy: %d\n", nr_copy_pages);
+        pbe = pblist;
         for_each_zone (zone) {
                 if (is_highmem(zone))
                         continue;
                 mark_free_pages(zone);
                 /* This is necessary for swsusp_free() */
-                for_each_pb_page (p, pagedir_nosave)
+                for_each_pb_page (p, pblist)
                         SetPageNosaveFree(virt_to_page(p));
-                for_each_pbe(p, pagedir_nosave)
+                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)) {
@@ -370,46 +371,39 @@ void swsusp_free(void)
  *      free pages.
  */
 
-static int enough_free_mem(void)
+static int enough_free_mem(unsigned nr_pages)
 {
         pr_debug("swsusp: available memory: %u pages\n", nr_free_pages());
-        return nr_free_pages() > (nr_copy_pages + PAGES_FOR_IO +
-                nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE));
+        return nr_free_pages() > (nr_pages + PAGES_FOR_IO +
+                (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
 }
 
 
-static int swsusp_alloc(void)
+static struct pbe *swsusp_alloc(unsigned nr_pages)
 {
-        struct pbe * p;
-
-        pagedir_nosave = NULL;
-
-        if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
-            !!(nr_copy_pages % PBES_PER_PAGE))
-                return -ENOSPC;
+        struct pbe *pblist, *p;
 
-        if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
+        if (!(pblist = alloc_pagedir(nr_pages))) {
                 printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
-                return -ENOMEM;
+                return NULL;
         }
-        create_pbe_list(pagedir_save, nr_copy_pages);
-        pagedir_nosave = pagedir_save;
+        create_pbe_list(pblist, nr_pages);
 
-        for_each_pbe (p, pagedir_save) {
+        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 -ENOMEM;
+                        return NULL;
                 }
         }
 
-        return 0;
+        return pblist;
 }
 
 static int suspend_prepare_image(void)
 {
-        int error;
+        unsigned nr_pages;
 
         pr_debug("swsusp: critical section: \n");
         if (save_highmem()) {
@@ -419,33 +413,37 @@ static int suspend_prepare_image(void)
         }
 
         drain_local_pages();
-        count_data_pages();
-        printk("swsusp: Need to copy %u pages\n", nr_copy_pages);
+        nr_pages = count_data_pages();
+        printk("swsusp: Need to copy %u pages\n", nr_pages);
 
         pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
-                 nr_copy_pages,
-                 nr_copy_pages/PBES_PER_PAGE + !!(nr_copy_pages%PBES_PER_PAGE),
+                 nr_pages,
+                 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
                  PAGES_FOR_IO, nr_free_pages());
 
-        if (!enough_free_mem()) {
+        /* This is needed because of the fixed size of swsusp_info */
+        if (MAX_PBES < (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE)
+                return -ENOSPC;
+
+        if (!enough_free_mem(nr_pages)) {
                 printk(KERN_ERR "swsusp: Not enough free memory\n");
                 return -ENOMEM;
         }
 
-        if (!enough_swap()) {
+        if (!enough_swap(nr_pages)) {
                 printk(KERN_ERR "swsusp: Not enough free swap\n");
                 return -ENOSPC;
         }
 
-        error = swsusp_alloc();
-        if (error)
-                return error;
+        pagedir_nosave = swsusp_alloc(nr_pages);
+        if (!pagedir_nosave)
+                return -ENOMEM;
 
         /* During allocating of suspend pagedir, new cold pages may appear.
          * Kill them.
          */
         drain_local_pages();
-        copy_data_pages();
+        copy_data_pages(pagedir_nosave);
 
         /*
          * End of critical section. From now on, we can write to memory,
@@ -453,7 +451,9 @@ static int suspend_prepare_image(void)
          * touch swap space! Except we must write out our image of course.
          */
 
-        printk("swsusp: critical section/: done (%d pages copied)\n", nr_copy_pages );
+        nr_copy_pages = nr_pages;
+
+        printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
         return 0;
 }