[PATCH] mempool: add kzalloc allocator

Add another allocator to the common mempool code: a kzalloc/kfree allocator

This will be used by the next patch in the series to replace a mempool-backed
kzalloc allocator.  It is also very likely that there will be more users in
the future.

Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mempool.h b/include/linux/mempool.h
index d23dbf0..41570ce 100644
--- a/include/linux/mempool.h
+++ b/include/linux/mempool.h
@@ -39,16 +39,22 @@
 void mempool_free_slab(void *element, void *pool_data);
 
 /*
- * A mempool_alloc_t and mempool_free_t to kmalloc the amount of memory
- * specified by pool_data
+ * 2 mempool_alloc_t's and a mempool_free_t to kmalloc/kzalloc and kfree
+ * the amount of memory specified by pool_data
  */
 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
+void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data);
 void mempool_kfree(void *element, void *pool_data);
 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
 {
 	return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
 			      (void *) size);
 }
+static inline mempool_t *mempool_create_kzalloc_pool(int min_nr, size_t size)
+{
+	return mempool_create(min_nr, mempool_kzalloc, mempool_kfree,
+			      (void *) size);
+}
 
 /*
  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
diff --git a/mm/mempool.c b/mm/mempool.c
index a1397c6..7bf064e 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -296,11 +296,18 @@
  */
 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
 {
-	size_t size = (size_t) pool_data;
+	size_t size = (size_t)(long)pool_data;
 	return kmalloc(size, gfp_mask);
 }
 EXPORT_SYMBOL(mempool_kmalloc);
 
+void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data)
+{
+	size_t size = (size_t) pool_data;
+	return kzalloc(size, gfp_mask);
+}
+EXPORT_SYMBOL(mempool_kzalloc);
+
 void mempool_kfree(void *element, void *pool_data)
 {
 	kfree(element);