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Commit 096b7bdc authored by Jesper Nilsson's avatar Jesper Nilsson
Browse files

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.*<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: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
parent 90276a1a

arch/cris/arch-v10/drivers/eeprom.c

+0 −2
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 
#include <linux/init.h>

#include <linux/delay.h>

#include <linux/interrupt.h>

#include <linux/smp_lock.h>

#include <linux/wait.h>

#include <asm/uaccess.h>

#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)

arch/cris/arch-v10/drivers/i2c.c

+0 −2
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 


#include <linux/module.h>

#include <linux/sched.h>

#include <linux/smp_lock.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/fs.h>
@@ -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;

}

arch/cris/arch-v32/drivers/cryptocop.c

+0 −2
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <linux/string.h>

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/smp_lock.h>

#include <linux/spinlock.h>

#include <linux/stddef.h>
@@ -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;

arch/cris/arch-v32/drivers/i2c.c

+6 −6
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ 
#include <linux/fs.h>

#include <linux/string.h>

#include <linux/init.h>

#include <linux/smp_lock.h>

#include <linux/mutex.h>



#include <asm/etraxi2c.h>
@@ -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;

		}