diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-06-02 16:28:52 +0400 |
---|---|---|
committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-05 17:01:04 +0400 |
commit | 613655fa39ff6957754fa8ceb8559980920eb8ee (patch) | |
tree | ad19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/ds1302.c | |
parent | 609146fdb319cebce93be550938ab852f7bade90 (diff) | |
download | linux-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.c | 15 |
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: |