linux/drivers/isdn/hardware/eicon/divamnt.c
Arnd Bergmann 76a64921da isdn: 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: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 20:21:47 -07:00

259 lines
5.5 KiB
C

/* $Id: divamnt.c,v 1.32.6.10 2005/02/11 19:40:25 armin Exp $
*
* Driver for Eicon DIVA Server ISDN cards.
* Maint module
*
* Copyright 2000-2003 by Armin Schindler (mac@melware.de)
* Copyright 2000-2003 Cytronics & Melware (info@melware.de)
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include "platform.h"
#include "di_defs.h"
#include "divasync.h"
#include "debug_if.h"
static DEFINE_MUTEX(maint_mutex);
static char *main_revision = "$Revision: 1.32.6.10 $";
static int major;
MODULE_DESCRIPTION("Maint driver for Eicon DIVA Server cards");
MODULE_AUTHOR("Cytronics & Melware, Eicon Networks");
MODULE_SUPPORTED_DEVICE("DIVA card driver");
MODULE_LICENSE("GPL");
static int buffer_length = 128;
module_param(buffer_length, int, 0);
static unsigned long diva_dbg_mem = 0;
module_param(diva_dbg_mem, ulong, 0);
static char *DRIVERNAME =
"Eicon DIVA - MAINT module (http://www.melware.net)";
static char *DRIVERLNAME = "diva_mnt";
static char *DEVNAME = "DivasMAINT";
char *DRIVERRELEASE_MNT = "2.0";
static wait_queue_head_t msgwaitq;
static unsigned long opened;
static struct timeval start_time;
extern int mntfunc_init(int *, void **, unsigned long);
extern void mntfunc_finit(void);
extern int maint_read_write(void __user *buf, int count);
/*
* helper functions
*/
static char *getrev(const char *revision)
{
char *rev;
char *p;
if ((p = strchr(revision, ':'))) {
rev = p + 2;
p = strchr(rev, '$');
*--p = 0;
} else
rev = "1.0";
return rev;
}
/*
* kernel/user space copy functions
*/
int diva_os_copy_to_user(void *os_handle, void __user *dst, const void *src,
int length)
{
return (copy_to_user(dst, src, length));
}
int diva_os_copy_from_user(void *os_handle, void *dst, const void __user *src,
int length)
{
return (copy_from_user(dst, src, length));
}
/*
* get time
*/
void diva_os_get_time(dword * sec, dword * usec)
{
struct timeval tv;
do_gettimeofday(&tv);
if (tv.tv_sec > start_time.tv_sec) {
if (start_time.tv_usec > tv.tv_usec) {
tv.tv_sec--;
tv.tv_usec += 1000000;
}
*sec = (dword) (tv.tv_sec - start_time.tv_sec);
*usec = (dword) (tv.tv_usec - start_time.tv_usec);
} else if (tv.tv_sec == start_time.tv_sec) {
*sec = 0;
if (start_time.tv_usec < tv.tv_usec) {
*usec = (dword) (tv.tv_usec - start_time.tv_usec);
} else {
*usec = 0;
}
} else {
*sec = (dword) tv.tv_sec;
*usec = (dword) tv.tv_usec;
}
}
/*
* device node operations
*/
static unsigned int maint_poll(struct file *file, poll_table * wait)
{
unsigned int mask = 0;
poll_wait(file, &msgwaitq, wait);
mask = POLLOUT | POLLWRNORM;
if (file->private_data || diva_dbg_q_length()) {
mask |= POLLIN | POLLRDNORM;
}
return (mask);
}
static int maint_open(struct inode *ino, struct file *filep)
{
int ret;
mutex_lock(&maint_mutex);
/* only one open is allowed, so we test
it atomically */
if (test_and_set_bit(0, &opened))
ret = -EBUSY;
else {
filep->private_data = NULL;
ret = nonseekable_open(ino, filep);
}
mutex_unlock(&maint_mutex);
return ret;
}
static int maint_close(struct inode *ino, struct file *filep)
{
if (filep->private_data) {
diva_os_free(0, filep->private_data);
filep->private_data = NULL;
}
/* clear 'used' flag */
clear_bit(0, &opened);
return (0);
}
static ssize_t divas_maint_write(struct file *file, const char __user *buf,
size_t count, loff_t * ppos)
{
return (maint_read_write((char __user *) buf, (int) count));
}
static ssize_t divas_maint_read(struct file *file, char __user *buf,
size_t count, loff_t * ppos)
{
return (maint_read_write(buf, (int) count));
}
static const struct file_operations divas_maint_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = divas_maint_read,
.write = divas_maint_write,
.poll = maint_poll,
.open = maint_open,
.release = maint_close
};
static void divas_maint_unregister_chrdev(void)
{
unregister_chrdev(major, DEVNAME);
}
static int DIVA_INIT_FUNCTION divas_maint_register_chrdev(void)
{
if ((major = register_chrdev(0, DEVNAME, &divas_maint_fops)) < 0)
{
printk(KERN_ERR "%s: failed to create /dev entry.\n",
DRIVERLNAME);
return (0);
}
return (1);
}
/*
* wake up reader
*/
void diva_maint_wakeup_read(void)
{
wake_up_interruptible(&msgwaitq);
}
/*
* Driver Load
*/
static int DIVA_INIT_FUNCTION maint_init(void)
{
char tmprev[50];
int ret = 0;
void *buffer = NULL;
do_gettimeofday(&start_time);
init_waitqueue_head(&msgwaitq);
printk(KERN_INFO "%s\n", DRIVERNAME);
printk(KERN_INFO "%s: Rel:%s Rev:", DRIVERLNAME, DRIVERRELEASE_MNT);
strcpy(tmprev, main_revision);
printk("%s Build: %s \n", getrev(tmprev), DIVA_BUILD);
if (!divas_maint_register_chrdev()) {
ret = -EIO;
goto out;
}
if (!(mntfunc_init(&buffer_length, &buffer, diva_dbg_mem))) {
printk(KERN_ERR "%s: failed to connect to DIDD.\n",
DRIVERLNAME);
divas_maint_unregister_chrdev();
ret = -EIO;
goto out;
}
printk(KERN_INFO "%s: trace buffer = %p - %d kBytes, %s (Major: %d)\n",
DRIVERLNAME, buffer, (buffer_length / 1024),
(diva_dbg_mem == 0) ? "internal" : "external", major);
out:
return (ret);
}
/*
** Driver Unload
*/
static void DIVA_EXIT_FUNCTION maint_exit(void)
{
divas_maint_unregister_chrdev();
mntfunc_finit();
printk(KERN_INFO "%s: module unloaded.\n", DRIVERLNAME);
}
module_init(maint_init);
module_exit(maint_exit);