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Commit d851b6e0 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

mac: 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>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org
parent 5aa82940

drivers/macintosh/adb.c

+5 −5
Original line number Diff line number Diff line
@@ -24,7 +24,6 @@ 
#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/sched.h>

#include <linux/smp_lock.h>

#include <linux/adb.h>

#include <linux/cuda.h>

#include <linux/pmu.h>
@@ -55,6 +54,7 @@ extern struct adb_driver adb_iop_driver; 
extern struct adb_driver via_pmu_driver;

extern struct adb_driver macio_adb_driver;



static DEFINE_MUTEX(adb_mutex);

static struct adb_driver *adb_driver_list[] = {

#ifdef CONFIG_ADB_MACII

	&via_macii_driver,
@@ -647,7 +647,7 @@ static int adb_open(struct inode *inode, struct file *file) 
	struct adbdev_state *state;

	int ret = 0;



	lock_kernel();

	mutex_lock(&adb_mutex);

	if (iminor(inode) > 0 || adb_controller == NULL) {

		ret = -ENXIO;

		goto out;
@@ -665,7 +665,7 @@ static int adb_open(struct inode *inode, struct file *file) 
	state->inuse = 1;



out:

	unlock_kernel();

	mutex_unlock(&adb_mutex);

	return ret;

}
@@ -674,7 +674,7 @@ static int adb_release(struct inode *inode, struct file *file) 
	struct adbdev_state *state = file->private_data;

	unsigned long flags;



	lock_kernel();

	mutex_lock(&adb_mutex);

	if (state) {

		file->private_data = NULL;

		spin_lock_irqsave(&state->lock, flags);
@@ -687,7 +687,7 @@ static int adb_release(struct inode *inode, struct file *file) 
			spin_unlock_irqrestore(&state->lock, flags);

		}

	}

	unlock_kernel();

	mutex_unlock(&adb_mutex);

	return 0;

}

drivers/macintosh/smu.c

+3 −3
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ 
 *    the userland interface

 */



#include <linux/smp_lock.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/device.h>
@@ -97,6 +96,7 @@ struct smu_device { 
 * I don't think there will ever be more than one SMU, so

 * for now, just hard code that

 */

static DEFINE_MUTEX(smu_mutex);

static struct smu_device	*smu;

static DEFINE_MUTEX(smu_part_access);

static int smu_irq_inited;
@@ -1095,12 +1095,12 @@ static int smu_open(struct inode *inode, struct file *file) 
	pp->mode = smu_file_commands;

	init_waitqueue_head(&pp->wait);



	lock_kernel();

	mutex_lock(&smu_mutex);

	spin_lock_irqsave(&smu_clist_lock, flags);

	list_add(&pp->list, &smu_clist);

	spin_unlock_irqrestore(&smu_clist_lock, flags);

	file->private_data = pp;

	unlock_kernel();

	mutex_unlock(&smu_mutex);



	return 0;

}

drivers/macintosh/via-pmu.c

+6 −5
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ 
 *

 */

#include <stdarg.h>

#include <linux/smp_lock.h>

#include <linux/mutex.h>

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>
@@ -73,6 +73,7 @@ 
/* How many iterations between battery polls */

#define BATTERY_POLLING_COUNT	2



static DEFINE_MUTEX(pmu_info_proc_mutex);

static volatile unsigned char __iomem *via;



/* VIA registers - spaced 0x200 bytes apart */
@@ -2078,7 +2079,7 @@ pmu_open(struct inode *inode, struct file *file) 
	pp->rb_get = pp->rb_put = 0;

	spin_lock_init(&pp->lock);

	init_waitqueue_head(&pp->wait);

	lock_kernel();

	mutex_lock(&pmu_info_proc_mutex);

	spin_lock_irqsave(&all_pvt_lock, flags);

#if defined(CONFIG_INPUT_ADBHID) && defined(CONFIG_PMAC_BACKLIGHT)

	pp->backlight_locker = 0;
@@ -2086,7 +2087,7 @@ pmu_open(struct inode *inode, struct file *file) 
	list_add(&pp->list, &all_pmu_pvt);

	spin_unlock_irqrestore(&all_pvt_lock, flags);

	file->private_data = pp;

	unlock_kernel();

	mutex_unlock(&pmu_info_proc_mutex);

	return 0;

}
@@ -2343,9 +2344,9 @@ static long pmu_unlocked_ioctl(struct file *filp, 
{

	int ret;



	lock_kernel();

	mutex_lock(&pmu_info_proc_mutex);

	ret = pmu_ioctl(filp, cmd, arg);

	unlock_kernel();

	mutex_unlock(&pmu_info_proc_mutex);



	return ret;

}