genalloc: use bitmap_find_next_zero_area
Akinobu Mita [Wed, 16 Dec 2009 00:48:31 +0000 (16:48 -0800)]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/genalloc.c

index eed2bdb..e67f974 100644 (file)
@@ -11,6 +11,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/bitmap.h>
 #include <linux/genalloc.h>
 
 
@@ -114,7 +115,7 @@ unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
        struct gen_pool_chunk *chunk;
        unsigned long addr, flags;
        int order = pool->min_alloc_order;
-       int nbits, bit, start_bit, end_bit;
+       int nbits, start_bit, end_bit;
 
        if (size == 0)
                return 0;
@@ -129,29 +130,19 @@ unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
                end_bit -= nbits + 1;
 
                spin_lock_irqsave(&chunk->lock, flags);
-               bit = -1;
-               while (bit + 1 < end_bit) {
-                       bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
-                       if (bit >= end_bit)
-                               break;
-
-                       start_bit = bit;
-                       if (nbits > 1) {
-                               bit = find_next_bit(chunk->bits, bit + nbits,
-                                                       bit + 1);
-                               if (bit - start_bit < nbits)
-                                       continue;
-                       }
-
-                       addr = chunk->start_addr +
-                                           ((unsigned long)start_bit << order);
-                       while (nbits--)
-                               __set_bit(start_bit++, chunk->bits);
+               start_bit = bitmap_find_next_zero_area(chunk->bits, end_bit, 0,
+                                               nbits, 0);
+               if (start_bit >= end_bit) {
                        spin_unlock_irqrestore(&chunk->lock, flags);
-                       read_unlock(&pool->lock);
-                       return addr;
+                       continue;
                }
+
+               addr = chunk->start_addr + ((unsigned long)start_bit << order);
+
+               bitmap_set(chunk->bits, start_bit, nbits);
                spin_unlock_irqrestore(&chunk->lock, flags);
+               read_unlock(&pool->lock);
+               return addr;
        }
        read_unlock(&pool->lock);
        return 0;