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![Alexander Shiyan](/assets/img/avatar_default.png)
This patch simplify functions indydog_start() and indydog_stop() a bit and removes excess intermediate variable. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
207 lines
4.6 KiB
C
207 lines
4.6 KiB
C
/*
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* IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
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*
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* (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>,
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/uaccess.h>
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#include <asm/sgi/mc.h>
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static unsigned long indydog_alive;
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static DEFINE_SPINLOCK(indydog_lock);
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#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static void indydog_start(void)
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{
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spin_lock(&indydog_lock);
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sgimc->cpuctrl0 |= SGIMC_CCTRL0_WDOG;
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spin_unlock(&indydog_lock);
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}
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static void indydog_stop(void)
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{
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spin_lock(&indydog_lock);
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sgimc->cpuctrl0 &= ~SGIMC_CCTRL0_WDOG;
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spin_unlock(&indydog_lock);
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pr_info("Stopped watchdog timer\n");
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}
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static void indydog_ping(void)
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{
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sgimc->watchdogt = 0;
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}
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/*
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* Allow only one person to hold it open
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*/
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static int indydog_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &indydog_alive))
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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/* Activate timer */
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indydog_start();
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indydog_ping();
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pr_info("Started watchdog timer\n");
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return nonseekable_open(inode, file);
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}
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static int indydog_release(struct inode *inode, struct file *file)
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{
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/* Shut off the timer.
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* Lock it in if it's a module and we defined ...NOWAYOUT */
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if (!nowayout)
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indydog_stop(); /* Turn the WDT off */
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clear_bit(0, &indydog_alive);
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return 0;
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}
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static ssize_t indydog_write(struct file *file, const char *data,
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size_t len, loff_t *ppos)
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{
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/* Refresh the timer. */
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if (len)
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indydog_ping();
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return len;
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}
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static long indydog_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int options, retval = -EINVAL;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING,
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.firmware_version = 0,
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.identity = "Hardware Watchdog for SGI IP22",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user((struct watchdog_info *)arg,
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&ident, sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, (int *)arg);
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case WDIOC_SETOPTIONS:
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{
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if (get_user(options, (int *)arg))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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indydog_stop();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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indydog_start();
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retval = 0;
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}
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return retval;
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}
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case WDIOC_KEEPALIVE:
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indydog_ping();
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return 0;
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case WDIOC_GETTIMEOUT:
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return put_user(WATCHDOG_TIMEOUT, (int *)arg);
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default:
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return -ENOTTY;
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}
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}
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static int indydog_notify_sys(struct notifier_block *this,
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unsigned long code, void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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indydog_stop(); /* Turn the WDT off */
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return NOTIFY_DONE;
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}
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static const struct file_operations indydog_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = indydog_write,
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.unlocked_ioctl = indydog_ioctl,
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.open = indydog_open,
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.release = indydog_release,
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};
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static struct miscdevice indydog_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &indydog_fops,
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};
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static struct notifier_block indydog_notifier = {
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.notifier_call = indydog_notify_sys,
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};
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static int __init watchdog_init(void)
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{
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int ret;
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ret = register_reboot_notifier(&indydog_notifier);
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if (ret) {
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pr_err("cannot register reboot notifier (err=%d)\n", ret);
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return ret;
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}
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ret = misc_register(&indydog_miscdev);
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if (ret) {
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pr_err("cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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unregister_reboot_notifier(&indydog_notifier);
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return ret;
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}
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pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n");
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return 0;
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}
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static void __exit watchdog_exit(void)
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{
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misc_deregister(&indydog_miscdev);
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unregister_reboot_notifier(&indydog_notifier);
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}
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module_init(watchdog_init);
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module_exit(watchdog_exit);
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MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
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MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
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MODULE_LICENSE("GPL");
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