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Subject[patch 2/7] 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>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
---
arch/m68k/bvme6000/rtc.c | 29 +++++++++--------------------
arch/m68k/mvme16x/rtc.c | 19 +++++--------------
2 files changed, 14 insertions(+), 34 deletions(-)

Index: linux-2.6-tip/arch/m68k/bvme6000/rtc.c
===================================================================
--- linux-2.6-tip.orig/arch/m68k/bvme6000/rtc.c
+++ linux-2.6-tip/arch/m68k/bvme6000/rtc.c
@@ -10,7 +10,6 @@
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/ioport.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
@@ -36,10 +35,9 @@
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;
@@ -133,29 +131,20 @@ static int rtc_ioctl(struct inode *inode
}

/*
- * 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;
}

@@ -164,9 +153,9 @@ static int rtc_release(struct inode *ino
*/

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 = {
Index: linux-2.6-tip/arch/m68k/mvme16x/rtc.c
===================================================================
--- linux-2.6-tip.orig/arch/m68k/mvme16x/rtc.c
+++ linux-2.6-tip/arch/m68k/mvme16x/rtc.c
@@ -10,7 +10,6 @@
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/ioport.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
@@ -37,8 +36,7 @@ static const unsigned char days_in_mo[]

static atomic_t rtc_ready = 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 MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
unsigned long flags;
@@ -121,22 +119,15 @@ static int rtc_ioctl(struct inode *inode
}

/*
- * 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( !atomic_dec_and_test(&rtc_ready) )
{
atomic_inc( &rtc_ready );
- unlock_kernel();
return -EBUSY;
}
- unlock_kernel();
-
return 0;
}

@@ -151,9 +142,9 @@ static int rtc_release(struct inode *ino
*/

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=



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