From 096b7bdc8663c16417ff5fbec42622302e6886e1 Mon Sep 17 00:00:00 2001 From: Jesper Nilsson Date: Fri, 30 Jul 2010 19:15:24 +0200 Subject: [PATCH] cris: 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.*/d' ${file} else sed -i 's/include.*.*$/include /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.*\/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann Signed-off-by: Jesper Nilsson --- arch/cris/arch-v10/drivers/eeprom.c | 2 -- arch/cris/arch-v10/drivers/i2c.c | 2 -- arch/cris/arch-v32/drivers/cryptocop.c | 2 -- arch/cris/arch-v32/drivers/i2c.c | 12 ++++++------ 4 files changed, 6 insertions(+), 12 deletions(-) diff --git a/arch/cris/arch-v10/drivers/eeprom.c b/arch/cris/arch-v10/drivers/eeprom.c index c3405507a3d1..5047a33043bd 100644 --- a/arch/cris/arch-v10/drivers/eeprom.c +++ b/arch/cris/arch-v10/drivers/eeprom.c @@ -28,7 +28,6 @@ #include #include #include -#include #include #include #include "i2c.h" @@ -376,7 +375,6 @@ int __init eeprom_init(void) /* Opens the device. */ static int eeprom_open(struct inode * inode, struct file * file) { - cycle_kernel_lock(); if(iminor(inode) != EEPROM_MINOR_NR) return -ENXIO; if(imajor(inode) != EEPROM_MAJOR_NR) diff --git a/arch/cris/arch-v10/drivers/i2c.c b/arch/cris/arch-v10/drivers/i2c.c index 399e089bed7a..54e2e1adf085 100644 --- a/arch/cris/arch-v10/drivers/i2c.c +++ b/arch/cris/arch-v10/drivers/i2c.c @@ -14,7 +14,6 @@ #include #include -#include #include #include #include @@ -566,7 +565,6 @@ i2c_readreg(unsigned char theSlave, unsigned char theReg) static int i2c_open(struct inode *inode, struct file *filp) { - cycle_kernel_lock(); return 0; } diff --git a/arch/cris/arch-v32/drivers/cryptocop.c b/arch/cris/arch-v32/drivers/cryptocop.c index 9cfbfae107c7..b07646a30509 100644 --- a/arch/cris/arch-v32/drivers/cryptocop.c +++ b/arch/cris/arch-v32/drivers/cryptocop.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include @@ -2307,7 +2306,6 @@ static int cryptocop_open(struct inode *inode, struct file *filp) { int p = iminor(inode); - cycle_kernel_lock(); if (p != CRYPTOCOP_MINOR) return -EINVAL; filp->private_data = NULL; diff --git a/arch/cris/arch-v32/drivers/i2c.c b/arch/cris/arch-v32/drivers/i2c.c index 2fd6a740d895..5a3e900c9a78 100644 --- a/arch/cris/arch-v32/drivers/i2c.c +++ b/arch/cris/arch-v32/drivers/i2c.c @@ -32,7 +32,7 @@ #include #include #include -#include +#include #include @@ -47,6 +47,7 @@ #define D(x) #define I2C_MAJOR 123 /* LOCAL/EXPERIMENTAL */ +static DEFINE_MUTEX(i2c_mutex); static const char i2c_name[] = "i2c"; #define CLOCK_LOW_TIME 8 @@ -636,7 +637,6 @@ i2c_readreg(unsigned char theSlave, unsigned char theReg) static int i2c_open(struct inode *inode, struct file *filp) { - cycle_kernel_lock(); return 0; } @@ -665,11 +665,11 @@ i2c_ioctl(struct file *file, unsigned int cmd, unsigned long arg) I2C_ARGREG(arg), I2C_ARGVALUE(arg))); - lock_kernel(); + mutex_lock(&i2c_mutex); ret = i2c_writereg(I2C_ARGSLAVE(arg), I2C_ARGREG(arg), I2C_ARGVALUE(arg)); - unlock_kernel(); + mutex_unlock(&i2c_mutex); return ret; case I2C_READREG: @@ -679,9 +679,9 @@ i2c_ioctl(struct file *file, unsigned int cmd, unsigned long arg) D(printk("i2cr %d %d ", I2C_ARGSLAVE(arg), I2C_ARGREG(arg))); - lock_kernel(); + mutex_lock(&i2c_mutex); val = i2c_readreg(I2C_ARGSLAVE(arg), I2C_ARGREG(arg)); - unlock_kernel(); + mutex_unlock(&i2c_mutex); D(printk("= %d\n", val)); return val; }