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authorArnd Bergmann <arnd@arndb.de>2010-06-02 16:28:52 +0400
committerArnd Bergmann <arnd@arndb.de>2010-10-05 17:01:04 +0400
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/ds1302.c
parent609146fdb319cebce93be550938ab852f7bade90 (diff)
downloadlinux-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.xz
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/ds1302.c')
-rw-r--r--drivers/char/ds1302.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/char/ds1302.c b/drivers/char/ds1302.c
index 170693c93c73..e3d72aa3cbd2 100644
--- a/drivers/char/ds1302.c
+++ b/drivers/char/ds1302.c
@@ -20,7 +20,7 @@
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/bcd.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/io.h>
@@ -32,6 +32,7 @@
#define RTC_MAJOR_NR 121 /* local major, change later */
+static DEFINE_MUTEX(rtc_mutex);
static const char ds1302_name[] = "ds1302";
/* Send 8 bits. */
@@ -164,9 +165,9 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct rtc_time rtc_tm;
memset(&rtc_tm, 0, sizeof (struct rtc_time));
- lock_kernel();
+ mutex_lock(&rtc_mutex);
get_rtc_time(&rtc_tm);
- unlock_kernel();
+ mutex_unlock(&rtc_mutex);
if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
return -EFAULT;
return 0;
@@ -218,7 +219,7 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
mon = bin2bcd(mon);
yrs = bin2bcd(yrs);
- lock_kernel();
+ mutex_lock(&rtc_mutex);
local_irq_save(flags);
CMOS_WRITE(yrs, RTC_YEAR);
CMOS_WRITE(mon, RTC_MONTH);
@@ -227,7 +228,7 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
CMOS_WRITE(min, RTC_MINUTES);
CMOS_WRITE(sec, RTC_SECONDS);
local_irq_restore(flags);
- unlock_kernel();
+ mutex_unlock(&rtc_mutex);
/* Notice that at this point, the RTC is updated but
* the kernel is still running with the old time.
@@ -247,10 +248,10 @@ static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
return -EFAULT;
- lock_kernel();
+ mutex_lock(&rtc_mutex);
tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
- unlock_kernel();
+ mutex_unlock(&rtc_mutex);
return 0;
}
default: