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>
diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 7baf1b6..4ad4d2c 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -13,7 +13,7 @@
#include <linux/miscdevice.h>
#include <linux/ioport.h> /* request_region */
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/atomic.h>
@@ -26,6 +26,7 @@
#define DRIVER_NAME "d7s"
#define PFX DRIVER_NAME ": "
+static DEFINE_MUTEX(d7s_mutex);
static int sol_compat = 0; /* Solaris compatibility mode */
/* Solaris compatibility flag -
@@ -74,7 +75,6 @@
{
if (D7S_MINOR != iminor(inode))
return -ENODEV;
- cycle_kernel_lock();
atomic_inc(&d7s_users);
return 0;
}
@@ -110,7 +110,7 @@
if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
return -ENODEV;
- lock_kernel();
+ mutex_lock(&d7s_mutex);
switch (cmd) {
case D7SIOCWR:
/* assign device register values we mask-out D7S_FLIP
@@ -151,7 +151,7 @@
writeb(regs, p->regs);
break;
};
- unlock_kernel();
+ mutex_unlock(&d7s_mutex);
return error;
}