m68k: Remove BKL from rtc implementations

m68k does not support SMP. The access to the rtc is already serialized
with local_irq_save/restore which is sufficient on UP.

The open() protection in arch/m68k/mvme16x/rtc.c is not pretty but
sufficient on UP and safe w/o the BKL.

open() in arch/m68k/bvme6000/rtc.c can do with the same atomic logic
as arch/m68k/mvme16x/rtc.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 9 insertions, 20 deletions

diff --git a/arch/m68k/bvme6000/rtc.c b/arch/m68k/bvme6000/rtc.c
index b46ea1714a89..cb8617bb194b 100644
--- a/arch/m68k/bvme6000/rtc.c
+++ b/arch/m68k/bvme6000/rtc.c
@@ -9,7 +9,6 @@
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/miscdevice.h>
-#include <linux/smp_lock.h>
 #include <linux/ioport.h>
 #include <linux/capability.h>
 #include <linux/fcntl.h>
@@ -35,10 +34,9 @@
 static unsigned char days_in_mo[] =
 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
-static char rtc_status;
+static atomic_t rtc_status = ATOMIC_INIT(1);
 
-static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
-                     unsigned long arg)
+static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
         volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
         unsigned char msr;
@@ -132,29 +130,20 @@ static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 }
 
 /*
- *      We enforce only one user at a time here with the open/close.
- *      Also clear the previous interrupt data on an open, and clean
- *      up things on a close.
+ * We enforce only one user at a time here with the open/close.
  */
-
 static int rtc_open(struct inode *inode, struct file *file)
 {
-        lock_kernel();
-        if(rtc_status) {
-                unlock_kernel();
+        if (!atomic_dec_and_test(&rtc_status)) {
+                atomic_inc(&rtc_status);
                 return -EBUSY;
         }
-
-        rtc_status = 1;
-        unlock_kernel();
         return 0;
 }
 
 static int rtc_release(struct inode *inode, struct file *file)
 {
-        lock_kernel();
-        rtc_status = 0;
-        unlock_kernel();
+        atomic_inc(&rtc_status);
         return 0;
 }
 
@@ -163,9 +152,9 @@ static int rtc_release(struct inode *inode, struct file *file)
  */
 
 static const struct file_operations rtc_fops = {
-        .ioctl =        rtc_ioctl,
-        .open =         rtc_open,
-        .release =      rtc_release,
+        .unlocked_ioctl = rtc_ioctl,
+        .open           = rtc_open,
+        .release        = rtc_release,
 };
 
 static struct miscdevice rtc_dev = {