genalloc: use bitmap_find_next_zero_area

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>

1 files changed, 12 insertions, 21 deletions

diff --git a/lib/genalloc.c b/lib/genalloc.c
index eed2bdb865e..e67f97495dd 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -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;