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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*
  *  Industrial Computer Source WDT501 driver
  *
  *  (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
  *                      All Rights Reserved.
  *
  *  Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
  *  warranty for any of this software. This material is provided
  *  "AS-IS" and at no charge.
  *
  *  (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
  *
  *  Release 0.10.
  *
  *  Fixes
  *      Dave Gregorich  :   Modularisation and minor bugs
  *      Alan Cox    :   Added the watchdog ioctl() stuff
  *      Alan Cox    :   Fixed the reboot problem (as noted by
  *                  Matt Crocker).
  *      Alan Cox    :   Added wdt= boot option
  *      Alan Cox    :   Cleaned up copy/user stuff
  *      Tim Hockin  :   Added insmod parameters, comment
  *                  cleanup, parameterized timeout
  *      Tigran Aivazian :   Restructured wdt_init() to handle
  *                  failures
  *      Joel Becker :   Added WDIOC_GET/SETTIMEOUT
  *      Matt Domsch :   Added nowayout module option
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/fs.h>
 #include <linux/ioport.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
 
 #include "wd501p.h"
 
 static unsigned long wdt_is_open;
 static char expect_close;
 
 /*
  *  Module parameters
  */
 
 #define WD_TIMO 60          /* Default heartbeat = 60 seconds */
 
 static int heartbeat = WD_TIMO;
 static int wd_heartbeat;
 module_param(heartbeat, int, 0);
 MODULE_PARM_DESC(heartbeat,
     "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
                 __MODULE_STRING(WD_TIMO) ")");
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout,
     "Watchdog cannot be stopped once started (default="
                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
 /* You must set these - there is no sane way to probe for this board. */
 static int io = 0x240;
 static int irq = 11;
 
 static DEFINE_SPINLOCK(wdt_lock);
 
 module_param_hw(io, int, ioport, 0);
 MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
 module_param_hw(irq, int, irq, 0);
 MODULE_PARM_DESC(irq, "WDT irq (default=11)");
 
 /* Support for the Fan Tachometer on the WDT501-P */
 static int tachometer;
 module_param(tachometer, int, 0);
 MODULE_PARM_DESC(tachometer,
         "WDT501-P Fan Tachometer support (0=disable, default=0)");
 
 static int type = 500;
 module_param(type, int, 0);
 MODULE_PARM_DESC(type,
         "WDT501-P Card type (500 or 501, default=500)");
 
 /*
  *  Programming support
  */
 
 static void wdt_ctr_mode(int ctr, int mode)
 {
     ctr <<= 6;
     ctr |= 0x30;
     ctr |= (mode << 1);
     outb_p(ctr, WDT_CR);
 }
 
 static void wdt_ctr_load(int ctr, int val)
 {
     outb_p(val&0xFF, WDT_COUNT0+ctr);
     outb_p(val>>8, WDT_COUNT0+ctr);
 }
 
 /**
  *  wdt_start:
  *
  *  Start the watchdog driver.
  */
 
 static int wdt_start(void)
 {
     unsigned long flags;
     spin_lock_irqsave(&wdt_lock, flags);
     inb_p(WDT_DC);          /* Disable watchdog */
     wdt_ctr_mode(0, 3);     /* Program CTR0 for Mode 3:
                         Square Wave Generator */
     wdt_ctr_mode(1, 2);     /* Program CTR1 for Mode 2:
                         Rate Generator */
     wdt_ctr_mode(2, 0);     /* Program CTR2 for Mode 0:
                         Pulse on Terminal Count */
     wdt_ctr_load(0, 8948);      /* Count at 100Hz */
     wdt_ctr_load(1, wd_heartbeat);  /* Heartbeat */
     wdt_ctr_load(2, 65535);     /* Length of reset pulse */
     outb_p(0, WDT_DC);      /* Enable watchdog */
     spin_unlock_irqrestore(&wdt_lock, flags);
     return 0;
 }
 
 /**
  *  wdt_stop:
  *
  *  Stop the watchdog driver.
  */
 
 static int wdt_stop(void)
 {
     unsigned long flags;
     spin_lock_irqsave(&wdt_lock, flags);
     /* Turn the card off */
     inb_p(WDT_DC);          /* Disable watchdog */
     wdt_ctr_load(2, 0);     /* 0 length reset pulses now */
     spin_unlock_irqrestore(&wdt_lock, flags);
     return 0;
 }
 
 /**
  *  wdt_ping:
  *
  *  Reload counter one with the watchdog heartbeat. We don't bother
  *  reloading the cascade counter.
  */
 
 static void wdt_ping(void)
 {
     unsigned long flags;
     spin_lock_irqsave(&wdt_lock, flags);
     /* Write a watchdog value */
     inb_p(WDT_DC);          /* Disable watchdog */
     wdt_ctr_mode(1, 2);     /* Re-Program CTR1 for Mode 2:
                             Rate Generator */
     wdt_ctr_load(1, wd_heartbeat);  /* Heartbeat */
     outb_p(0, WDT_DC);      /* Enable watchdog */
     spin_unlock_irqrestore(&wdt_lock, flags);
 }
 
 /**
  *  wdt_set_heartbeat:
  *  @t:     the new heartbeat value that needs to be set.
  *
  *  Set a new heartbeat value for the watchdog device. If the heartbeat
  *  value is incorrect we keep the old value and return -EINVAL. If
  *  successful we return 0.
  */
 
 static int wdt_set_heartbeat(int t)
 {
     if (t < 1 || t > 65535)
         return -EINVAL;
 
     heartbeat = t;
     wd_heartbeat = t * 100;
     return 0;
 }
 
 /**
  *  wdt_get_status:
  *
  *  Extract the status information from a WDT watchdog device. There are
  *  several board variants so we have to know which bits are valid. Some
  *  bits default to one and some to zero in order to be maximally painful.
  *
  *  we then map the bits onto the status ioctl flags.
  */
 
 static int wdt_get_status(void)
 {
     unsigned char new_status;
     int status = 0;
     unsigned long flags;
 
     spin_lock_irqsave(&wdt_lock, flags);
     new_status = inb_p(WDT_SR);
     spin_unlock_irqrestore(&wdt_lock, flags);
 
     if (new_status & WDC_SR_ISOI0)
         status |= WDIOF_EXTERN1;
     if (new_status & WDC_SR_ISII1)
         status |= WDIOF_EXTERN2;
     if (type == 501) {
         if (!(new_status & WDC_SR_TGOOD))
             status |= WDIOF_OVERHEAT;
         if (!(new_status & WDC_SR_PSUOVER))
             status |= WDIOF_POWEROVER;
         if (!(new_status & WDC_SR_PSUUNDR))
             status |= WDIOF_POWERUNDER;
         if (tachometer) {
             if (!(new_status & WDC_SR_FANGOOD))
                 status |= WDIOF_FANFAULT;
         }
     }
     return status;
 }
 
 /**
  *  wdt_get_temperature:
  *
  *  Reports the temperature in degrees Fahrenheit. The API is in
  *  farenheit. It was designed by an imperial measurement luddite.
  */
 
 static int wdt_get_temperature(void)
 {
     unsigned short c;
     unsigned long flags;
 
     spin_lock_irqsave(&wdt_lock, flags);
     c = inb_p(WDT_RT);
     spin_unlock_irqrestore(&wdt_lock, flags);
     return (c * 11 / 15) + 7;
 }
 
 static void wdt_decode_501(int status)
 {
     if (!(status & WDC_SR_TGOOD))
         pr_crit("Overheat alarm (%d)\n", inb_p(WDT_RT));
     if (!(status & WDC_SR_PSUOVER))
         pr_crit("PSU over voltage\n");
     if (!(status & WDC_SR_PSUUNDR))
         pr_crit("PSU under voltage\n");
 }
 
 /**
  *  wdt_interrupt:
  *  @irq:       Interrupt number
  *  @dev_id:    Unused as we don't allow multiple devices.
  *
  *  Handle an interrupt from the board. These are raised when the status
  *  map changes in what the board considers an interesting way. That means
  *  a failure condition occurring.
  */
 
 static irqreturn_t wdt_interrupt(int irq, void *dev_id)
 {
     /*
      *  Read the status register see what is up and
      *  then printk it.
      */
     unsigned char status;
 
     spin_lock(&wdt_lock);
     status = inb_p(WDT_SR);
 
     pr_crit("WDT status %d\n", status);
 
     if (type == 501) {
         wdt_decode_501(status);
         if (tachometer) {
             if (!(status & WDC_SR_FANGOOD))
                 pr_crit("Possible fan fault\n");
         }
     }
     if (!(status & WDC_SR_WCCR)) {
 #ifdef SOFTWARE_REBOOT
 #ifdef ONLY_TESTING
         pr_crit("Would Reboot\n");
 #else
         pr_crit("Initiating system reboot\n");
         emergency_restart();
 #endif
 #else
         pr_crit("Reset in 5ms\n");
 #endif
     }
     spin_unlock(&wdt_lock);
     return IRQ_HANDLED;
 }
 
 
 /**
  *  wdt_write:
  *  @file: file handle to the watchdog
  *  @buf: buffer to write (unused as data does not matter here
  *  @count: count of bytes
  *  @ppos: pointer to the position to write. No seeks allowed
  *
  *  A write to a watchdog device is defined as a keepalive signal. Any
  *  write of data will do, as we we don't define content meaning.
  */
 
 static ssize_t wdt_write(struct file *file, const char __user *buf,
                         size_t count, loff_t *ppos)
 {
     if (count) {
         if (!nowayout) {
             size_t i;
 
             /* In case it was set long ago */
             expect_close = 0;
 
             for (i = 0; i != count; i++) {
                 char c;
                 if (get_user(c, buf + i))
                     return -EFAULT;
                 if (c == 'V')
                     expect_close = 42;
             }
         }
         wdt_ping();
     }
     return count;
 }
 
 /**
  *  wdt_ioctl:
  *  @file: file handle to the device
  *  @cmd: watchdog command
  *  @arg: argument pointer
  *
  *  The watchdog API defines a common set of functions for all watchdogs
  *  according to their available features. We only actually usefully support
  *  querying capabilities and current status.
  */
 
 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
     void __user *argp = (void __user *)arg;
     int __user *p = argp;
     int new_heartbeat;
     int status;
 
     struct watchdog_info ident = {
         .options =      WDIOF_SETTIMEOUT|
                     WDIOF_MAGICCLOSE|
                     WDIOF_KEEPALIVEPING,
         .firmware_version = 1,
         .identity =     "WDT500/501",
     };
 
     /* Add options according to the card we have */
     ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
     if (type == 501) {
         ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
                             WDIOF_POWEROVER);
         if (tachometer)
             ident.options |= WDIOF_FANFAULT;
     }
 
     switch (cmd) {
     case WDIOC_GETSUPPORT:
         return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
     case WDIOC_GETSTATUS:
         status = wdt_get_status();
         return put_user(status, p);
     case WDIOC_GETBOOTSTATUS:
         return put_user(0, p);
     case WDIOC_KEEPALIVE:
         wdt_ping();
         return 0;
     case WDIOC_SETTIMEOUT:
         if (get_user(new_heartbeat, p))
             return -EFAULT;
         if (wdt_set_heartbeat(new_heartbeat))
             return -EINVAL;
         wdt_ping();
         fallthrough;
     case WDIOC_GETTIMEOUT:
         return put_user(heartbeat, p);
     default:
         return -ENOTTY;
     }
 }
 
 /**
  *  wdt_open:
  *  @inode: inode of device
  *  @file: file handle to device
  *
  *  The watchdog device has been opened. The watchdog device is single
  *  open and on opening we load the counters. Counter zero is a 100Hz
  *  cascade, into counter 1 which downcounts to reboot. When the counter
  *  triggers counter 2 downcounts the length of the reset pulse which
  *  set set to be as long as possible.
  */
 
 static int wdt_open(struct inode *inode, struct file *file)
 {
     if (test_and_set_bit(0, &wdt_is_open))
         return -EBUSY;
     /*
      *  Activate
      */
     wdt_start();
     return stream_open(inode, file);
 }
 
 /**
  *  wdt_release:
  *  @inode: inode to board
  *  @file: file handle to board
  *
  *  The watchdog has a configurable API. There is a religious dispute
  *  between people who want their watchdog to be able to shut down and
  *  those who want to be sure if the watchdog manager dies the machine
  *  reboots. In the former case we disable the counters, in the latter
  *  case you have to open it again very soon.
  */
 
 static int wdt_release(struct inode *inode, struct file *file)
 {
     if (expect_close == 42) {
         wdt_stop();
         clear_bit(0, &wdt_is_open);
     } else {
         pr_crit("WDT device closed unexpectedly.  WDT will not stop!\n");
         wdt_ping();
     }
     expect_close = 0;
     return 0;
 }
 
 /**
  *  wdt_temp_read:
  *  @file: file handle to the watchdog board
  *  @buf: buffer to write 1 byte into
  *  @count: length of buffer
  *  @ptr: offset (no seek allowed)
  *
  *  Temp_read reports the temperature in degrees Fahrenheit. The API is in
  *  farenheit. It was designed by an imperial measurement luddite.
  */
 
 static ssize_t wdt_temp_read(struct file *file, char __user *buf,
                         size_t count, loff_t *ptr)
 {
     int temperature = wdt_get_temperature();
 
     if (copy_to_user(buf, &temperature, 1))
         return -EFAULT;
 
     return 1;
 }
 
 /**
  *  wdt_temp_open:
  *  @inode: inode of device
  *  @file: file handle to device
  *
  *  The temperature device has been opened.
  */
 
 static int wdt_temp_open(struct inode *inode, struct file *file)
 {
     return stream_open(inode, file);
 }
 
 /**
  *  wdt_temp_release:
  *  @inode: inode to board
  *  @file: file handle to board
  *
  *  The temperature device has been closed.
  */
 
 static int wdt_temp_release(struct inode *inode, struct file *file)
 {
     return 0;
 }
 
 /**
  *  wdt_notify_sys:
  *  @this: our notifier block
  *  @code: the event being reported
  *  @unused: unused
  *
  *  Our notifier is called on system shutdowns. We want to turn the card
  *  off at reboot otherwise the machine will reboot again during memory
  *  test or worse yet during the following fsck. This would suck, in fact
  *  trust me - if it happens it does suck.
  */
 
 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
     void *unused)
 {
     if (code == SYS_DOWN || code == SYS_HALT)
         wdt_stop();
     return NOTIFY_DONE;
 }
 
 /*
  *  Kernel Interfaces
  */
 
 
 static const struct file_operations wdt_fops = {
     .owner      = THIS_MODULE,
     .llseek     = no_llseek,
     .write      = wdt_write,
     .unlocked_ioctl = wdt_ioctl,
     .compat_ioctl   = compat_ptr_ioctl,
     .open       = wdt_open,
     .release    = wdt_release,
 };
 
 static struct miscdevice wdt_miscdev = {
     .minor  = WATCHDOG_MINOR,
     .name   = "watchdog",
     .fops   = &wdt_fops,
 };
 
 static const struct file_operations wdt_temp_fops = {
     .owner      = THIS_MODULE,
     .llseek     = no_llseek,
     .read       = wdt_temp_read,
     .open       = wdt_temp_open,
     .release    = wdt_temp_release,
 };
 
 static struct miscdevice temp_miscdev = {
     .minor  = TEMP_MINOR,
     .name   = "temperature",
     .fops   = &wdt_temp_fops,
 };
 
 /*
  *  The WDT card needs to learn about soft shutdowns in order to
  *  turn the timebomb registers off.
  */
 
 static struct notifier_block wdt_notifier = {
     .notifier_call = wdt_notify_sys,
 };
 
 /**
  *  wdt_exit:
  *
  *  Unload the watchdog. You cannot do this with any file handles open.
  *  If your watchdog is set to continue ticking on close and you unload
  *  it, well it keeps ticking. We won't get the interrupt but the board
  *  will not touch PC memory so all is fine. You just have to load a new
  *  module in 60 seconds or reboot.
  */
 
 static void __exit wdt_exit(void)
 {
     misc_deregister(&wdt_miscdev);
     if (type == 501)
         misc_deregister(&temp_miscdev);
     unregister_reboot_notifier(&wdt_notifier);
     free_irq(irq, NULL);
     release_region(io, 8);
 }
 
 /**
  *  wdt_init:
  *
  *  Set up the WDT watchdog board. All we have to do is grab the
  *  resources we require and bitch if anyone beat us to them.
  *  The open() function will actually kick the board off.
  */
 
 static int __init wdt_init(void)
 {
     int ret;
 
     if (type != 500 && type != 501) {
         pr_err("unknown card type '%d'\n", type);
         return -ENODEV;
     }
 
     /* Check that the heartbeat value is within it's range;
        if not reset to the default */
     if (wdt_set_heartbeat(heartbeat)) {
         wdt_set_heartbeat(WD_TIMO);
         pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
             WD_TIMO);
     }
 
     if (!request_region(io, 8, "wdt501p")) {
         pr_err("I/O address 0x%04x already in use\n", io);
         ret = -EBUSY;
         goto out;
     }
 
     ret = request_irq(irq, wdt_interrupt, 0, "wdt501p", NULL);
     if (ret) {
         pr_err("IRQ %d is not free\n", irq);
         goto outreg;
     }
 
     ret = register_reboot_notifier(&wdt_notifier);
     if (ret) {
         pr_err("cannot register reboot notifier (err=%d)\n", ret);
         goto outirq;
     }
 
     if (type == 501) {
         ret = misc_register(&temp_miscdev);
         if (ret) {
             pr_err("cannot register miscdev on minor=%d (err=%d)\n",
                    TEMP_MINOR, ret);
             goto outrbt;
         }
     }
 
     ret = misc_register(&wdt_miscdev);
     if (ret) {
         pr_err("cannot register miscdev on minor=%d (err=%d)\n",
                WATCHDOG_MINOR, ret);
         goto outmisc;
     }
 
     pr_info("WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
         io, irq, heartbeat, nowayout);
     if (type == 501)
         pr_info("Fan Tachometer is %s\n",
             tachometer ? "Enabled" : "Disabled");
     return 0;
 
 outmisc:
     if (type == 501)
         misc_deregister(&temp_miscdev);
 outrbt:
     unregister_reboot_notifier(&wdt_notifier);
 outirq:
     free_irq(irq, NULL);
 outreg:
     release_region(io, 8);
 out:
     return ret;
 }
 
 module_init(wdt_init);
 module_exit(wdt_exit);
 
 MODULE_AUTHOR("Alan Cox");
 MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
 MODULE_LICENSE("GPL");

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