lkml.org 
[lkml]   [2010]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 08/12] sbus: autoconvert trivial BKL users to private mutex
Date
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>
Cc: "David S. Miller" <davem@davemloft.net>
---
drivers/sbus/char/display7seg.c | 8 ++++----
drivers/sbus/char/envctrl.c | 2 --
drivers/sbus/char/flash.c | 15 ++++++++-------
drivers/sbus/char/openprom.c | 15 ++++++++-------
drivers/sbus/char/uctrl.c | 7 ++++---
5 files changed, 24 insertions(+), 23 deletions(-)

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 @@ static int d7s_open(struct inode *inode, struct file *f)
{
if (D7S_MINOR != iminor(inode))
return -ENODEV;
- cycle_kernel_lock();
atomic_inc(&d7s_users);
return 0;
}
@@ -110,7 +110,7 @@ static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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 @@ static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
writeb(regs, p->regs);
break;
};
- unlock_kernel();
+ mutex_unlock(&d7s_mutex);

return error;
}
diff --git a/drivers/sbus/char/envctrl.c b/drivers/sbus/char/envctrl.c
index c8166ec..bd0bbc6 100644
--- a/drivers/sbus/char/envctrl.c
+++ b/drivers/sbus/char/envctrl.c
@@ -27,7 +27,6 @@
#include <linux/kmod.h>
#include <linux/reboot.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/of.h>
#include <linux/of_device.h>

@@ -699,7 +698,6 @@ envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
static int
envctrl_open(struct inode *inode, struct file *file)
{
- cycle_kernel_lock();
file->private_data = NULL;
return 0;
}
diff --git a/drivers/sbus/char/flash.c b/drivers/sbus/char/flash.c
index 368d662..ed9494e 100644
--- a/drivers/sbus/char/flash.c
+++ b/drivers/sbus/char/flash.c
@@ -10,7 +10,7 @@
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
@@ -22,6 +22,7 @@
#include <asm/io.h>
#include <asm/upa.h>

+static DEFINE_MUTEX(flash_mutex);
static DEFINE_SPINLOCK(flash_lock);
static struct {
unsigned long read_base; /* Physical read address */
@@ -80,7 +81,7 @@ flash_mmap(struct file *file, struct vm_area_struct *vma)
static long long
flash_llseek(struct file *file, long long offset, int origin)
{
- lock_kernel();
+ mutex_lock(&flash_mutex);
switch (origin) {
case 0:
file->f_pos = offset;
@@ -94,10 +95,10 @@ flash_llseek(struct file *file, long long offset, int origin)
file->f_pos = flash.read_size;
break;
default:
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return -EINVAL;
}
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return file->f_pos;
}

@@ -125,13 +126,13 @@ flash_read(struct file * file, char __user * buf,
static int
flash_open(struct inode *inode, struct file *file)
{
- lock_kernel();
+ mutex_lock(&flash_mutex);
if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return -EBUSY;
}

- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return 0;
}

diff --git a/drivers/sbus/char/openprom.c b/drivers/sbus/char/openprom.c
index d53e62a..72f04fc 100644
--- a/drivers/sbus/char/openprom.c
+++ b/drivers/sbus/char/openprom.c
@@ -33,7 +33,7 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
@@ -61,6 +61,7 @@ typedef struct openprom_private_data
} DATA;

/* ID of the PROM node containing all of the EEPROM options. */
+static DEFINE_MUTEX(openprom_mutex);
static struct device_node *options_node;

/*
@@ -316,7 +317,7 @@ static long openprom_sunos_ioctl(struct file * file,
if (bufsize < 0)
return bufsize;

- lock_kernel();
+ mutex_lock(&openprom_mutex);

switch (cmd) {
case OPROMGETOPT:
@@ -367,7 +368,7 @@ static long openprom_sunos_ioctl(struct file * file,
}

kfree(opp);
- unlock_kernel();
+ mutex_unlock(&openprom_mutex);

return error;
}
@@ -558,7 +559,7 @@ static int openprom_bsd_ioctl(struct file * file,
void __user *argp = (void __user *)arg;
int err;

- lock_kernel();
+ mutex_lock(&openprom_mutex);
switch (cmd) {
case OPIOCGET:
err = opiocget(argp, data);
@@ -589,7 +590,7 @@ static int openprom_bsd_ioctl(struct file * file,
err = -EINVAL;
break;
};
- unlock_kernel();
+ mutex_unlock(&openprom_mutex);

return err;
}
@@ -697,11 +698,11 @@ static int openprom_open(struct inode * inode, struct file * file)
if (!data)
return -ENOMEM;

- lock_kernel();
+ mutex_lock(&openprom_mutex);
data->current_node = of_find_node_by_path("/");
data->lastnode = data->current_node;
file->private_data = (void *) data;
- unlock_kernel();
+ mutex_unlock(&openprom_mutex);

return 0;
}
diff --git a/drivers/sbus/char/uctrl.c b/drivers/sbus/char/uctrl.c
index 5f25366..079da4c 100644
--- a/drivers/sbus/char/uctrl.c
+++ b/drivers/sbus/char/uctrl.c
@@ -9,7 +9,7 @@
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
@@ -72,6 +72,7 @@ struct ts102_regs {
#define UCTRL_STAT_RXNE_STA 0x04 /* receive FIFO not empty status */
#define UCTRL_STAT_RXO_STA 0x08 /* receive FIFO overflow status */

+static DEFINE_MUTEX(uctrl_mutex);
static const char *uctrl_extstatus[16] = {
"main power available",
"internal battery attached",
@@ -210,10 +211,10 @@ uctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
static int
uctrl_open(struct inode *inode, struct file *file)
{
- lock_kernel();
+ mutex_lock(&uctrl_mutex);
uctrl_get_event_status(global_driver);
uctrl_get_external_status(global_driver);
- unlock_kernel();
+ mutex_unlock(&uctrl_mutex);
return 0;
}

--
1.7.1


\
 
 \ /
  Last update: 2010-07-11 23:21    [W:0.112 / U:1.456 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site