diff --git a/drivers/net/pcmcia/pcnet_cs.c b/drivers/net/pcmcia/pcnet_cs.c
index 51bbd582f16c..9ba56aa26a1b 100644
--- a/drivers/net/pcmcia/pcnet_cs.c
+++ b/drivers/net/pcmcia/pcnet_cs.c
@@ -38,6 +38,7 @@
 #include <linux/delay.h>
 #include <linux/ethtool.h>
 #include <linux/netdevice.h>
+#include <linux/log2.h>
 #include "../8390.h"
 
 #include <pcmcia/cs_types.h>
@@ -1484,8 +1485,7 @@ static int setup_shmem_window(struct pcmcia_device *link, int start_pg,
 	window_size = 32 * 1024;
 
     /* Make sure it's a power of two.  */
-    while ((window_size & (window_size - 1)) != 0)
-	window_size += window_size & ~(window_size - 1);
+    window_size = roundup_pow_of_two(window_size);
 
     /* Allocate a memory window */
     req.Attributes = WIN_DATA_WIDTH_16|WIN_MEMORY_TYPE_CM|WIN_ENABLE;