![Arjan van de Ven](/assets/img/avatar_default.png)
Mark the static struct file_operations in drivers/char as const. Making them const prevents accidental bugs, and moves them to the .rodata section so that they no longer do any false sharing; in addition with the proper debug option they are then protected against corruption.. [akpm@osdl.org: build fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
303 lines
6.5 KiB
C
303 lines
6.5 KiB
C
/*
|
|
* MixCom Watchdog: A Simple Hardware Watchdog Device
|
|
* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
|
|
*
|
|
* Author: Gergely Madarasz <gorgo@itc.hu>
|
|
*
|
|
* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
* Version 0.1 (99/04/15):
|
|
* - first version
|
|
*
|
|
* Version 0.2 (99/06/16):
|
|
* - added kernel timer watchdog ping after close
|
|
* since the hardware does not support watchdog shutdown
|
|
*
|
|
* Version 0.3 (99/06/21):
|
|
* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
|
|
*
|
|
* Version 0.3.1 (99/06/22):
|
|
* - allow module removal while internal timer is active,
|
|
* print warning about probable reset
|
|
*
|
|
* Version 0.4 (99/11/15):
|
|
* - support for one more type board
|
|
*
|
|
* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
|
|
* - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
|
|
*
|
|
*/
|
|
|
|
#define VERSION "0.5"
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/timer.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
|
|
static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };
|
|
|
|
#define MIXCOM_WATCHDOG_OFFSET 0xc10
|
|
#define MIXCOM_ID 0x11
|
|
#define FLASHCOM_WATCHDOG_OFFSET 0x4
|
|
#define FLASHCOM_ID 0x18
|
|
|
|
static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
|
|
|
|
static int watchdog_port;
|
|
static int mixcomwd_timer_alive;
|
|
static DEFINE_TIMER(mixcomwd_timer, NULL, 0, 0);
|
|
static char expect_close;
|
|
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
|
|
|
|
static void mixcomwd_ping(void)
|
|
{
|
|
outb_p(55,watchdog_port);
|
|
return;
|
|
}
|
|
|
|
static void mixcomwd_timerfun(unsigned long d)
|
|
{
|
|
mixcomwd_ping();
|
|
|
|
mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
|
|
}
|
|
|
|
/*
|
|
* Allow only one person to hold it open
|
|
*/
|
|
|
|
static int mixcomwd_open(struct inode *inode, struct file *file)
|
|
{
|
|
if(test_and_set_bit(0,&mixcomwd_opened)) {
|
|
return -EBUSY;
|
|
}
|
|
mixcomwd_ping();
|
|
|
|
if (nowayout) {
|
|
/*
|
|
* fops_get() code via open() has already done
|
|
* a try_module_get() so it is safe to do the
|
|
* __module_get().
|
|
*/
|
|
__module_get(THIS_MODULE);
|
|
} else {
|
|
if(mixcomwd_timer_alive) {
|
|
del_timer(&mixcomwd_timer);
|
|
mixcomwd_timer_alive=0;
|
|
}
|
|
}
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int mixcomwd_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (expect_close == 42) {
|
|
if(mixcomwd_timer_alive) {
|
|
printk(KERN_ERR "mixcomwd: release called while internal timer alive");
|
|
return -EBUSY;
|
|
}
|
|
init_timer(&mixcomwd_timer);
|
|
mixcomwd_timer.expires=jiffies + 5 * HZ;
|
|
mixcomwd_timer.function=mixcomwd_timerfun;
|
|
mixcomwd_timer.data=0;
|
|
mixcomwd_timer_alive=1;
|
|
add_timer(&mixcomwd_timer);
|
|
} else {
|
|
printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly. WDT will not stop!\n");
|
|
}
|
|
|
|
clear_bit(0,&mixcomwd_opened);
|
|
expect_close=0;
|
|
return 0;
|
|
}
|
|
|
|
|
|
static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
|
|
{
|
|
if(len)
|
|
{
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
/* In case it was set long ago */
|
|
expect_close = 0;
|
|
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
expect_close = 42;
|
|
}
|
|
}
|
|
mixcomwd_ping();
|
|
}
|
|
return len;
|
|
}
|
|
|
|
static int mixcomwd_ioctl(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int status;
|
|
static struct watchdog_info ident = {
|
|
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
|
|
.firmware_version = 1,
|
|
.identity = "MixCOM watchdog",
|
|
};
|
|
|
|
switch(cmd)
|
|
{
|
|
case WDIOC_GETSTATUS:
|
|
status=mixcomwd_opened;
|
|
if (!nowayout) {
|
|
status|=mixcomwd_timer_alive;
|
|
}
|
|
if (copy_to_user(p, &status, sizeof(int))) {
|
|
return -EFAULT;
|
|
}
|
|
break;
|
|
case WDIOC_GETSUPPORT:
|
|
if (copy_to_user(argp, &ident, sizeof(ident))) {
|
|
return -EFAULT;
|
|
}
|
|
break;
|
|
case WDIOC_KEEPALIVE:
|
|
mixcomwd_ping();
|
|
break;
|
|
default:
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations mixcomwd_fops=
|
|
{
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = mixcomwd_write,
|
|
.ioctl = mixcomwd_ioctl,
|
|
.open = mixcomwd_open,
|
|
.release = mixcomwd_release,
|
|
};
|
|
|
|
static struct miscdevice mixcomwd_miscdev=
|
|
{
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &mixcomwd_fops,
|
|
};
|
|
|
|
static int __init mixcomwd_checkcard(int port)
|
|
{
|
|
int id;
|
|
|
|
port += MIXCOM_WATCHDOG_OFFSET;
|
|
if (!request_region(port, 1, "MixCOM watchdog")) {
|
|
return 0;
|
|
}
|
|
|
|
id=inb_p(port) & 0x3f;
|
|
if(id!=MIXCOM_ID) {
|
|
release_region(port, 1);
|
|
return 0;
|
|
}
|
|
return port;
|
|
}
|
|
|
|
static int __init flashcom_checkcard(int port)
|
|
{
|
|
int id;
|
|
|
|
port += FLASHCOM_WATCHDOG_OFFSET;
|
|
if (!request_region(port, 1, "MixCOM watchdog")) {
|
|
return 0;
|
|
}
|
|
|
|
id=inb_p(port);
|
|
if(id!=FLASHCOM_ID) {
|
|
release_region(port, 1);
|
|
return 0;
|
|
}
|
|
return port;
|
|
}
|
|
|
|
static int __init mixcomwd_init(void)
|
|
{
|
|
int i;
|
|
int ret;
|
|
int found=0;
|
|
|
|
for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) {
|
|
watchdog_port = mixcomwd_checkcard(mixcomwd_ioports[i]);
|
|
if (watchdog_port) {
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
/* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */
|
|
for (i = 0x300; !found && i < 0x380; i+=0x8) {
|
|
watchdog_port = flashcom_checkcard(i);
|
|
if (watchdog_port) {
|
|
found = 1;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
printk("mixcomwd: No card detected, or port not available.\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
ret = misc_register(&mixcomwd_miscdev);
|
|
if (ret)
|
|
{
|
|
release_region(watchdog_port, 1);
|
|
return ret;
|
|
}
|
|
|
|
printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit mixcomwd_exit(void)
|
|
{
|
|
if (!nowayout) {
|
|
if(mixcomwd_timer_alive) {
|
|
printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
|
|
" probably reboot!\n");
|
|
del_timer(&mixcomwd_timer);
|
|
mixcomwd_timer_alive=0;
|
|
}
|
|
}
|
|
release_region(watchdog_port,1);
|
|
misc_deregister(&mixcomwd_miscdev);
|
|
}
|
|
|
|
module_init(mixcomwd_init);
|
|
module_exit(mixcomwd_exit);
|
|
|
|
MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
|
|
MODULE_DESCRIPTION("MixCom Watchdog driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|