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use mutex instead of semaphore in virtual console driver

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The virtual console driver uses a semaphore as mutex.  Use the mutex API
instead of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthias Kaehlcke
2007-05-08 00:39:49 -07:00
committed by Linus Torvalds
parent 159dde9369
commit c831c338f0
3 changed files with 15 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/char/vc_screen.c
View File

@@ -28,11 +28,13 @@
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/mutex.h>
#include <linux/vt_kern.h> #include <linux/vt_kern.h>
#include <linux/selection.h> #include <linux/selection.h>
#include <linux/kbd_kern.h> #include <linux/kbd_kern.h>
#include <linux/console.h> #include <linux/console.h>
#include <linux/device.h> #include <linux/device.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/byteorder.h> #include <asm/byteorder.h>
#include <asm/unaligned.h> #include <asm/unaligned.h>
@@ -69,11 +71,11 @@ static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
{ {
int size; int size;
down(&con_buf_sem); mutex_lock(&con_buf_mtx);
size = vcs_size(file->f_path.dentry->d_inode); size = vcs_size(file->f_path.dentry->d_inode);
switch (orig) { switch (orig) {
default: default:
up(&con_buf_sem); mutex_unlock(&con_buf_mtx);
return -EINVAL; return -EINVAL;
case 2: case 2:
offset += size; offset += size;
@@ -84,11 +86,11 @@ static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
break; break;
} }
if (offset < 0 || offset > size) { if (offset < 0 || offset > size) {
up(&con_buf_sem); mutex_unlock(&con_buf_mtx);
return -EINVAL; return -EINVAL;
} }
file->f_pos = offset; file->f_pos = offset;
up(&con_buf_sem); mutex_unlock(&con_buf_mtx);
return file->f_pos; return file->f_pos;
} }
@@ -105,7 +107,7 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
unsigned short *org = NULL; unsigned short *org = NULL;
ssize_t ret; ssize_t ret;
down(&con_buf_sem); mutex_lock(&con_buf_mtx);
pos = *ppos; pos = *ppos;
@@ -262,7 +264,7 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
ret = read; ret = read;
unlock_out: unlock_out:
release_console_sem(); release_console_sem();
up(&con_buf_sem); mutex_unlock(&con_buf_mtx);
return ret; return ret;
} }
@@ -279,7 +281,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
u16 *org0 = NULL, *org = NULL; u16 *org0 = NULL, *org = NULL;
size_t ret; size_t ret;
down(&con_buf_sem); mutex_lock(&con_buf_mtx);
pos = *ppos; pos = *ppos;
@@ -449,7 +451,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
unlock_out: unlock_out:
release_console_sem(); release_console_sem();
up(&con_buf_sem); mutex_unlock(&con_buf_mtx);
return ret; return ret;
} }

5
drivers/char/vt.c
View File

@@ -86,6 +86,7 @@
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/console.h> #include <linux/console.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/mutex.h>
#include <linux/vt_kern.h> #include <linux/vt_kern.h>
#include <linux/selection.h> #include <linux/selection.h>
#include <linux/tiocl.h> #include <linux/tiocl.h>
@@ -1952,7 +1953,7 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
* kernel memory allocation is available. * kernel memory allocation is available.
*/ */
char con_buf[CON_BUF_SIZE]; char con_buf[CON_BUF_SIZE];
DECLARE_MUTEX(con_buf_sem); DEFINE_MUTEX(con_buf_mtx);
/* is_double_width() is based on the wcwidth() implementation by /* is_double_width() is based on the wcwidth() implementation by
* Markus Kuhn -- 2003-05-20 (Unicode 4.0) * Markus Kuhn -- 2003-05-20 (Unicode 4.0)
@@ -2049,7 +2050,7 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
/* At this point 'buf' is guaranteed to be a kernel buffer /* At this point 'buf' is guaranteed to be a kernel buffer
* and therefore no access to userspace (and therefore sleeping) * and therefore no access to userspace (and therefore sleeping)
* will be needed. The con_buf_sem serializes all tty based * will be needed. The con_buf_mtx serializes all tty based
* console rendering and vcs write/read operations. We hold * console rendering and vcs write/read operations. We hold
* the console spinlock during the entire write. * the console spinlock during the entire write.
*/ */

3
include/linux/vt_kern.h
View File

@@ -9,6 +9,7 @@
#include <linux/vt.h> #include <linux/vt.h>
#include <linux/kd.h> #include <linux/kd.h>
#include <linux/tty.h> #include <linux/tty.h>
#include <linux/mutex.h>
#include <linux/console_struct.h> #include <linux/console_struct.h>
#include <linux/mm.h> #include <linux/mm.h>
@@ -82,7 +83,7 @@ void reset_vc(struct vc_data *vc);
#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) #define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
extern char con_buf[CON_BUF_SIZE]; extern char con_buf[CON_BUF_SIZE];
extern struct semaphore con_buf_sem; extern struct mutex con_buf_mtx;
extern char vt_dont_switch; extern char vt_dont_switch;
struct vt_spawn_console { struct vt_spawn_console {