[PATCH] swsusp cleanups
[powerpc.git] / kernel / power / snapshot.c
index 0f0a7f3..723f517 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 +87,10 @@ static int save_highmem_zone(struct zone *zone)
        }
        return 0;
 }
-#endif /* CONFIG_HIGHMEM */
 
 
 static int save_highmem(void)
 {
-#ifdef CONFIG_HIGHMEM
        struct zone *zone;
        int res = 0;
 
@@ -125,13 +101,11 @@ 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;
@@ -144,9 +118,12 @@ int restore_highmem(void)
                free_page((long) save->data);
                kfree(save);
        }
-#endif
        return 0;
 }
+#else
+static int save_highmem(void) { return 0; }
+int restore_highmem(void) { return 0; }
+#endif /* CONFIG_HIGHMEM */
 
 
 static int pfn_is_nosave(unsigned long pfn)
@@ -165,10 +142,10 @@ 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;
@@ -187,41 +164,41 @@ 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;
-
-       nr_copy_pages = 0;
+       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)
-                       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)) {
-                               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);
@@ -239,7 +216,7 @@ static void copy_data_pages(void)
  *     free_pagedir - free pages allocated with alloc_pagedir()
  */
 
-void free_pagedir(struct pbe *pblist)
+static void free_pagedir(struct pbe *pblist)
 {
        struct pbe *pbe;
 
@@ -272,10 +249,10 @@ 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)
@@ -315,21 +292,21 @@ 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)
 {
-       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();
        /* 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();
        }
        if (!pbe) { /* get_zeroed_page() failed */
                free_pagedir(pblist);
@@ -351,7 +328,7 @@ 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);
@@ -370,46 +347,39 @@ void swsusp_free(void)
  *     free pages.
  */
 
-static int enough_free_mem(void)
+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_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 int nr_pages)
 {
-       struct pbe * p;
-
-       pagedir_nosave = NULL;
+       struct pbe *pblist, *p;
 
-       if (MAX_PBES < nr_copy_pages / PBES_PER_PAGE +
-           !!(nr_copy_pages % PBES_PER_PAGE))
-               return -ENOSPC;
-
-       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)
+asmlinkage int swsusp_save(void)
 {
-       int error;
+       unsigned int nr_pages;
 
        pr_debug("swsusp: critical section: \n");
        if (save_highmem()) {
@@ -419,33 +389,37 @@ 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,
@@ -453,12 +427,8 @@ 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 );
-       return 0;
-}
-
+       nr_copy_pages = nr_pages;
 
-asmlinkage int swsusp_save(void)
-{
-       return suspend_prepare_image();
+       printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
+       return 0;
 }