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path: root/kernel/power/swsusp.c
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Diffstat (limited to 'kernel/power/swsusp.c')
-rw-r--r--kernel/power/swsusp.c137
1 files changed, 73 insertions, 64 deletions
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 175370824f3..1109023d835 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -50,6 +50,7 @@
#include <linux/syscalls.h>
#include <linux/highmem.h>
#include <linux/time.h>
+#include <linux/rbtree.h>
#include "power.h"
@@ -74,72 +75,69 @@ static inline unsigned int count_highmem_pages(void) { return 0; }
/**
* The following functions are used for tracing the allocated
* swap pages, so that they can be freed in case of an error.
- *
- * The functions operate on a linked bitmap structure defined
- * in power.h
*/
-void free_bitmap(struct bitmap_page *bitmap)
-{
- struct bitmap_page *bp;
+struct swsusp_extent {
+ struct rb_node node;
+ unsigned long start;
+ unsigned long end;
+};
- while (bitmap) {
- bp = bitmap->next;
- free_page((unsigned long)bitmap);
- bitmap = bp;
- }
-}
+static struct rb_root swsusp_extents = RB_ROOT;
-struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
+static int swsusp_extents_insert(unsigned long swap_offset)
{
- struct bitmap_page *bitmap, *bp;
- unsigned int n;
-
- if (!nr_bits)
- return NULL;
-
- bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
- bp = bitmap;
- for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) {
- bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
- bp = bp->next;
- if (!bp) {
- free_bitmap(bitmap);
- return NULL;
+ struct rb_node **new = &(swsusp_extents.rb_node);
+ struct rb_node *parent = NULL;
+ struct swsusp_extent *ext;
+
+ /* Figure out where to put the new node */
+ while (*new) {
+ ext = container_of(*new, struct swsusp_extent, node);
+ parent = *new;
+ if (swap_offset < ext->start) {
+ /* Try to merge */
+ if (swap_offset == ext->start - 1) {
+ ext->start--;
+ return 0;
+ }
+ new = &((*new)->rb_left);
+ } else if (swap_offset > ext->end) {
+ /* Try to merge */
+ if (swap_offset == ext->end + 1) {
+ ext->end++;
+ return 0;
+ }
+ new = &((*new)->rb_right);
+ } else {
+ /* It already is in the tree */
+ return -EINVAL;
}
}
- return bitmap;
-}
-
-static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
-{
- unsigned int n;
-
- n = BITMAP_PAGE_BITS;
- while (bitmap && n <= bit) {
- n += BITMAP_PAGE_BITS;
- bitmap = bitmap->next;
- }
- if (!bitmap)
- return -EINVAL;
- n -= BITMAP_PAGE_BITS;
- bit -= n;
- n = 0;
- while (bit >= BITS_PER_CHUNK) {
- bit -= BITS_PER_CHUNK;
- n++;
- }
- bitmap->chunks[n] |= (1UL << bit);
+ /* Add the new node and rebalance the tree. */
+ ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
+ if (!ext)
+ return -ENOMEM;
+
+ ext->start = swap_offset;
+ ext->end = swap_offset;
+ rb_link_node(&ext->node, parent, new);
+ rb_insert_color(&ext->node, &swsusp_extents);
return 0;
}
-sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap)
+/**
+ * alloc_swapdev_block - allocate a swap page and register that it has
+ * been allocated, so that it can be freed in case of an error.
+ */
+
+sector_t alloc_swapdev_block(int swap)
{
unsigned long offset;
offset = swp_offset(get_swap_page_of_type(swap));
if (offset) {
- if (bitmap_set(bitmap, offset))
+ if (swsusp_extents_insert(offset))
swap_free(swp_entry(swap, offset));
else
return swapdev_block(swap, offset);
@@ -147,23 +145,34 @@ sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap)
return 0;
}
-void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
+/**
+ * free_all_swap_pages - free swap pages allocated for saving image data.
+ * It also frees the extents used to register which swap entres had been
+ * allocated.
+ */
+
+void free_all_swap_pages(int swap)
{
- unsigned int bit, n;
- unsigned long test;
-
- bit = 0;
- while (bitmap) {
- for (n = 0; n < BITMAP_PAGE_CHUNKS; n++)
- for (test = 1UL; test; test <<= 1) {
- if (bitmap->chunks[n] & test)
- swap_free(swp_entry(swap, bit));
- bit++;
- }
- bitmap = bitmap->next;
+ struct rb_node *node;
+
+ while ((node = swsusp_extents.rb_node)) {
+ struct swsusp_extent *ext;
+ unsigned long offset;
+
+ ext = container_of(node, struct swsusp_extent, node);
+ rb_erase(node, &swsusp_extents);
+ for (offset = ext->start; offset <= ext->end; offset++)
+ swap_free(swp_entry(swap, offset));
+
+ kfree(ext);
}
}
+int swsusp_swap_in_use(void)
+{
+ return (swsusp_extents.rb_node != NULL);
+}
+
/**
* swsusp_show_speed - print the time elapsed between two events represented by
* @start and @stop