1 files changed, 3 insertions, 2 deletions

diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c
index e55569bee7d0..bf7ba128b963 100644
--- a/net/mac80211/aes_ccm.c
+++ b/net/mac80211/aes_ccm.c
@@ -7,6 +7,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/crypto.h>
 #include <linux/err.h>
@@ -63,7 +64,7 @@ void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch,
         s_0 = scratch + AES_BLOCK_LEN;
         e = scratch + 2 * AES_BLOCK_LEN;
 
-        num_blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
+        num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
         last_len = data_len % AES_BLOCK_LEN;
         aes_ccm_prepare(tfm, b_0, aad, b, s_0, b);
 
@@ -102,7 +103,7 @@ int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch,
         s_0 = scratch + AES_BLOCK_LEN;
         a = scratch + 2 * AES_BLOCK_LEN;
 
-        num_blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
+        num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
         last_len = data_len % AES_BLOCK_LEN;
         aes_ccm_prepare(tfm, b_0, aad, b, s_0, a);