cris: autoconvert trivial BKL users

All uses of the big kernel lock in the cris architecture
are for ioctl and open functions of character device drivers,
which can be trivially converted to a per-driver mutex.

Most of these are probably unnecessary, so it may make sense
to audit them and eventually remove the extra mutex introduced
by this patch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: linux-cris-kernel@axis.com

3 files changed, 13 insertions, 11 deletions

diff --git a/arch/cris/arch-v10/drivers/ds1302.c b/arch/cris/arch-v10/drivers/ds1302.c
index 884275629ef..4b92ad08b0f 100644
--- a/arch/cris/arch-v10/drivers/ds1302.c
+++ b/arch/cris/arch-v10/drivers/ds1302.c
@@ -19,7 +19,7 @@
 #include <linux/module.h>
 #include <linux/miscdevice.h>
 #include <linux/delay.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/bcd.h>
 #include <linux/capability.h>
 
@@ -34,6 +34,7 @@
 
 #define RTC_MAJOR_NR 121 /* local major, change later */
 
+static DEFINE_MUTEX(ds1302_mutex);
 static const char ds1302_name[] = "ds1302";
 
 /* The DS1302 might be connected to different bits on different products. 
@@ -357,9 +358,9 @@ static long rtc_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned lon
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&ds1302_mutex);
 	ret = rtc_ioctl(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&ds1302_mutex);
 
 	return ret;
 }
diff --git a/arch/cris/arch-v10/drivers/pcf8563.c b/arch/cris/arch-v10/drivers/pcf8563.c
index 7dcb1f85f42..2f1ddedca2b 100644
--- a/arch/cris/arch-v10/drivers/pcf8563.c
+++ b/arch/cris/arch-v10/drivers/pcf8563.c
@@ -27,7 +27,6 @@
 #include <linux/delay.h>
 #include <linux/bcd.h>
 #include <linux/mutex.h>
-#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -49,6 +48,7 @@
 #define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)
 #define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)
 
+static DEFINE_MUTEX(pcf8563_mutex);
 static DEFINE_MUTEX(rtc_lock); /* Protect state etc */
 
 static const unsigned char days_in_month[] =
@@ -343,9 +343,9 @@ static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&pcf8563_mutex);
 	return pcf8563_ioctl(filp, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&pcf8563_mutex);
 
 	return ret;
 }
diff --git a/arch/cris/arch-v10/drivers/sync_serial.c b/arch/cris/arch-v10/drivers/sync_serial.c
index ee2dd4323da..3d9fa074a94 100644
--- a/arch/cris/arch-v10/drivers/sync_serial.c
+++ b/arch/cris/arch-v10/drivers/sync_serial.c
@@ -20,7 +20,7 @@
 #include <linux/interrupt.h>
 #include <linux/poll.h>
 #include <linux/init.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/timer.h>
 #include <asm/irq.h>
 #include <asm/dma.h>
@@ -149,6 +149,7 @@ struct sync_port {
 };
 
 
+static DEFINE_MUTEX(sync_serial_mutex);
 static int etrax_sync_serial_init(void);
 static void initialize_port(int portnbr);
 static inline int sync_data_avail(struct sync_port *port);
@@ -445,7 +446,7 @@ static int sync_serial_open(struct inode *inode, struct file *file)
 	int mode;
 	int err = -EBUSY;
 
-	lock_kernel();
+	mutex_lock(&sync_serial_mutex);
 	DEBUG(printk(KERN_DEBUG "Open sync serial port %d\n", dev));
 
 	if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled) {
@@ -626,7 +627,7 @@ static int sync_serial_open(struct inode *inode, struct file *file)
 	ret = 0;
 	
 out:
-	unlock_kernel();
+	mutex_unlock(&sync_serial_mutex);
 	return ret;
 }
 
@@ -961,9 +962,9 @@ static long sync_serial_ioctl(struct file *file,
 {
 	long ret;
 
-	lock_kernel();
+	mutex_lock(&sync_serial_mutex);
 	ret = sync_serial_ioctl_unlocked(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&sync_serial_mutex);
 
 	return ret;
 }