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Message-Id: <1284494124-7384-7-git-send-email-arnd@arndb.de>
Date: Tue, 14 Sep 2010 21:55:22 +0200
From: Arnd Bergmann <arnd@...db.de>
To: linux-kernel@...r.kernel.org
Subject: [PATCH 16/18] dvb-core: kill the big kernel lock
The dvb core only uses the big kernel lock in the open
and ioctl functions, which means it can be replaced with
a dvb specific mutex. Fortunately, all the ioctl functions
go through dvb_usercopy, so we can move the serialization
in there.
Signed-off-by: Arnd Bergmann <arnd@...db.de>
Cc: Mauro Carvalho Chehab <mchehab@...radead.org>
Cc: linux-media@...r.kernel.org
---
drivers/media/dvb/dvb-core/dmxdev.c | 17 ++---------------
drivers/media/dvb/dvb-core/dvb_ca_en50221.c | 8 +-------
drivers/media/dvb/dvb-core/dvb_net.c | 9 +--------
drivers/media/dvb/dvb-core/dvbdev.c | 17 +++++++----------
4 files changed, 11 insertions(+), 40 deletions(-)
diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c
index 0042306..2de13b0 100644
--- a/drivers/media/dvb/dvb-core/dmxdev.c
+++ b/drivers/media/dvb/dvb-core/dmxdev.c
@@ -25,7 +25,6 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
-#include <linux/smp_lock.h>
#include <linux/poll.h>
#include <linux/ioctl.h>
#include <linux/wait.h>
@@ -1088,13 +1087,7 @@ static int dvb_demux_do_ioctl(struct file *file,
static long dvb_demux_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
- int ret;
-
- lock_kernel();
- ret = dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);
- unlock_kernel();
-
- return ret;
+ return dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);
}
static unsigned int dvb_demux_poll(struct file *file, poll_table *wait)
@@ -1186,13 +1179,7 @@ static int dvb_dvr_do_ioctl(struct file *file,
static long dvb_dvr_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
- int ret;
-
- lock_kernel();
- ret = dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);
- unlock_kernel();
-
- return ret;
+ return dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);
}
static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)
diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
index cb97e6b..1723a98 100644
--- a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
@@ -1259,13 +1259,7 @@ static int dvb_ca_en50221_io_do_ioctl(struct file *file,
static long dvb_ca_en50221_io_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
- int ret;
-
- lock_kernel();
- ret = dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
- unlock_kernel();
-
- return ret;
+ return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
}
diff --git a/drivers/media/dvb/dvb-core/dvb_net.c b/drivers/media/dvb/dvb-core/dvb_net.c
index 6c3a8a0..a080322 100644
--- a/drivers/media/dvb/dvb-core/dvb_net.c
+++ b/drivers/media/dvb/dvb-core/dvb_net.c
@@ -59,7 +59,6 @@
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/dvb/net.h>
-#include <linux/smp_lock.h>
#include <linux/uio.h>
#include <asm/uaccess.h>
#include <linux/crc32.h>
@@ -1445,13 +1444,7 @@ static int dvb_net_do_ioctl(struct file *file,
static long dvb_net_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
- int ret;
-
- lock_kernel();
- ret = dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
- unlock_kernel();
-
- return ret;
+ return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
}
static int dvb_net_close(struct inode *inode, struct file *file)
diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c
index b915c39..28f486e 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.c
+++ b/drivers/media/dvb/dvb-core/dvbdev.c
@@ -32,9 +32,9 @@
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
-#include <linux/smp_lock.h>
#include "dvbdev.h"
+static DEFINE_MUTEX(dvbdev_mutex);
static int dvbdev_debug;
module_param(dvbdev_debug, int, 0644);
@@ -68,7 +68,7 @@ static int dvb_device_open(struct inode *inode, struct file *file)
{
struct dvb_device *dvbdev;
- lock_kernel();
+ mutex_lock(&dvbdev_mutex);
down_read(&minor_rwsem);
dvbdev = dvb_minors[iminor(inode)];
@@ -91,12 +91,12 @@ static int dvb_device_open(struct inode *inode, struct file *file)
}
fops_put(old_fops);
up_read(&minor_rwsem);
- unlock_kernel();
+ mutex_unlock(&dvbdev_mutex);
return err;
}
fail:
up_read(&minor_rwsem);
- unlock_kernel();
+ mutex_unlock(&dvbdev_mutex);
return -ENODEV;
}
@@ -158,7 +158,6 @@ long dvb_generic_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
struct dvb_device *dvbdev = file->private_data;
- int ret;
if (!dvbdev)
return -ENODEV;
@@ -166,11 +165,7 @@ long dvb_generic_ioctl(struct file *file,
if (!dvbdev->kernel_ioctl)
return -EINVAL;
- lock_kernel();
- ret = dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
- unlock_kernel();
-
- return ret;
+ return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
}
EXPORT_SYMBOL(dvb_generic_ioctl);
@@ -421,8 +416,10 @@ int dvb_usercopy(struct file *file,
}
/* call driver */
+ mutex_lock(&dvbdev_mutex);
if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
err = -EINVAL;
+ mutex_unlock(&dvbdev_mutex);
if (err < 0)
goto out;
--
1.7.1
--
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