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>
diff --git a/drivers/char/dsp56k.c b/drivers/char/dsp56k.c
index 8a1b28a..b3c7562 100644
--- a/drivers/char/dsp56k.c
+++ b/drivers/char/dsp56k.c
@@ -32,7 +32,7 @@
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/device.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/firmware.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h> /* For put_user and get_user */
@@ -94,6 +94,7 @@
} \
}
+static DEFINE_MUTEX(dsp56k_mutex);
static struct dsp56k_device {
unsigned long in_use;
long maxio, timeout;
@@ -330,9 +331,9 @@
if (len > DSP56K_MAX_BINARY_LENGTH) {
return -EINVAL;
}
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
r = dsp56k_upload(bin, len);
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
if (r < 0) {
return r;
}
@@ -342,16 +343,16 @@
case DSP56K_SET_TX_WSIZE:
if (arg > 4 || arg < 1)
return -EINVAL;
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
dsp56k.tx_wsize = (int) arg;
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
break;
case DSP56K_SET_RX_WSIZE:
if (arg > 4 || arg < 1)
return -EINVAL;
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
dsp56k.rx_wsize = (int) arg;
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
break;
case DSP56K_HOST_FLAGS:
{
@@ -363,7 +364,7 @@
if(get_user(out, &hf->out) < 0)
return -EFAULT;
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
if ((dir & 0x1) && (out & 0x1))
dsp56k_host_interface.icr |= DSP56K_ICR_HF0;
else if (dir & 0x1)
@@ -378,16 +379,16 @@
if (dsp56k_host_interface.icr & DSP56K_ICR_HF1) status |= 0x2;
if (dsp56k_host_interface.isr & DSP56K_ISR_HF2) status |= 0x4;
if (dsp56k_host_interface.isr & DSP56K_ISR_HF3) status |= 0x8;
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
return put_user(status, &hf->status);
}
case DSP56K_HOST_CMD:
if (arg > 31 || arg < 0)
return -EINVAL;
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
dsp56k_host_interface.cvr = (u_char)((arg & DSP56K_CVR_HV_MASK) |
DSP56K_CVR_HC);
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
break;
default:
return -EINVAL;
@@ -427,7 +428,7 @@
int dev = iminor(inode) & 0x0f;
int ret = 0;
- lock_kernel();
+ mutex_lock(&dsp56k_mutex);
switch(dev)
{
case DSP56K_DEV_56001:
@@ -454,7 +455,7 @@
ret = -ENODEV;
}
out:
- unlock_kernel();
+ mutex_unlock(&dsp56k_mutex);
return ret;
}