diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index b860d65..e927607 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -120,7 +120,7 @@
 #include <linux/timer.h>
 #include <linux/dma-mapping.h>
 #include <linux/list.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 
 #ifdef GDTH_RTC
@@ -140,6 +140,7 @@
 #include <scsi/scsi_host.h>
 #include "gdth.h"
 
+static DEFINE_MUTEX(gdth_mutex);
 static void gdth_delay(int milliseconds);
 static void gdth_eval_mapping(u32 size, u32 *cyls, int *heads, int *secs);
 static irqreturn_t gdth_interrupt(int irq, void *dev_id);
@@ -4042,12 +4043,12 @@
 {
     gdth_ha_str *ha;
 
-    lock_kernel();
+    mutex_lock(&gdth_mutex);
     list_for_each_entry(ha, &gdth_instances, list) {
         if (!ha->sdev)
             ha->sdev = scsi_get_host_dev(ha->shost);
     }
-    unlock_kernel();
+    mutex_unlock(&gdth_mutex);
 
     TRACE(("gdth_open()\n"));
     return 0;
@@ -4615,9 +4616,9 @@
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&gdth_mutex);
 	ret = gdth_ioctl(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&gdth_mutex);
 
 	return ret;
 }