diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-07-20 23:36:39 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2010-07-20 23:36:39 -0700 |
commit | a3108ca2323dec0f6321c3f7706cdaed51f694ea (patch) | |
tree | ae3ef899219893cf3de5d543d4e3dc7027c00212 /drivers/sbus/char/uctrl.c | |
parent | f8324e20f8289dffc646d64366332e05eaacab25 (diff) | |
download | linux-a3108ca2323dec0f6321c3f7706cdaed51f694ea.tar.gz linux-a3108ca2323dec0f6321c3f7706cdaed51f694ea.tar.bz2 linux-a3108ca2323dec0f6321c3f7706cdaed51f694ea.zip |
sbus: 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.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/sbus/char/uctrl.c')
-rw-r--r-- | drivers/sbus/char/uctrl.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/sbus/char/uctrl.c b/drivers/sbus/char/uctrl.c index 5f253665a1da..079da4cb45a5 100644 --- a/drivers/sbus/char/uctrl.c +++ b/drivers/sbus/char/uctrl.c @@ -9,7 +9,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/slab.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/miscdevice.h> @@ -72,6 +72,7 @@ struct ts102_regs { #define UCTRL_STAT_RXNE_STA 0x04 /* receive FIFO not empty status */ #define UCTRL_STAT_RXO_STA 0x08 /* receive FIFO overflow status */ +static DEFINE_MUTEX(uctrl_mutex); static const char *uctrl_extstatus[16] = { "main power available", "internal battery attached", @@ -210,10 +211,10 @@ uctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) static int uctrl_open(struct inode *inode, struct file *file) { - lock_kernel(); + mutex_lock(&uctrl_mutex); uctrl_get_event_status(global_driver); uctrl_get_external_status(global_driver); - unlock_kernel(); + mutex_unlock(&uctrl_mutex); return 0; } |