path: root/drivers/char/genrtc.c
diff options
authorArnd Bergmann <arnd@arndb.de>2010-06-02 14:28:52 +0200
committerArnd Bergmann <arnd@arndb.de>2010-10-05 15:01:04 +0200
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/genrtc.c
parentipmi: autoconvert trivial BKL users to private mutex (diff)
drivers: autoconvert trivial BKL users to private mutex
All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. These drivers do not seem to be under active maintainance from my brief investigation. Apologies to those maintainers that I have missed. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/char/genrtc.c')
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/char/genrtc.c b/drivers/char/genrtc.c
index b6c2cc167c11..2aa69f97360d 100644
--- a/drivers/char/genrtc.c
+++ b/drivers/char/genrtc.c
@@ -52,7 +52,7 @@
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
@@ -66,6 +66,7 @@
* ioctls.
+static DEFINE_MUTEX(gen_rtc_mutex);
static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
@@ -337,9 +338,9 @@ static long gen_rtc_unlocked_ioctl(struct file *file, unsigned int cmd,
int ret;
- lock_kernel();
+ mutex_lock(&gen_rtc_mutex);
ret = gen_rtc_ioctl(file, cmd, arg);
- unlock_kernel();
+ mutex_unlock(&gen_rtc_mutex);
return ret;
@@ -352,16 +353,16 @@ static long gen_rtc_unlocked_ioctl(struct file *file, unsigned int cmd,
static int gen_rtc_open(struct inode *inode, struct file *file)
- lock_kernel();
+ mutex_lock(&gen_rtc_mutex);
if (gen_rtc_status & RTC_IS_OPEN) {
- unlock_kernel();
+ mutex_unlock(&gen_rtc_mutex);
return -EBUSY;
gen_rtc_status |= RTC_IS_OPEN;
gen_rtc_irq_data = 0;
irq_active = 0;
- unlock_kernel();
+ mutex_unlock(&gen_rtc_mutex);
return 0;