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authorArnd Bergmann <arnd@arndb.de>2010-07-21 10:36:39 +0400
committerDavid S. Miller <davem@davemloft.net>2010-07-21 10:36:39 +0400
commita3108ca2323dec0f6321c3f7706cdaed51f694ea (patch)
treeae3ef899219893cf3de5d543d4e3dc7027c00212 /drivers/sbus/char/uctrl.c
parentf8324e20f8289dffc646d64366332e05eaacab25 (diff)
downloadlinux-a3108ca2323dec0f6321c3f7706cdaed51f694ea.tar.xz
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.c7
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;
}