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Commit f172ddc6 authored by Chen Gong's avatar Chen Gong Committed by Wim Van Sebroeck
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[WATCHDOG] Fix booke_wdt.c on MPC85xx SMP system's 



On Book-E SMP systems each core has its own private watchdog.  If only one
watchdog is enabled, when the core that doesn't enable the watchdog is hung,
system can't reset because no watchdog is running on it.  That's bad.  It
means we must enable watchdogs on both cores.

We can use smp_call_function() to send appropriate messages to all the other
cores to enable and update the watchdog.

Signed-off-by: default avatarChen Gong <g.chen@freescale.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 0b36086b

drivers/watchdog/booke_wdt.c

+40 −48
Original line number Diff line number Diff line 
/*

 * drivers/char/watchdog/booke_wdt.c

 *

 * Watchdog timer for PowerPC Book-E systems

 *

 * Author: Matthew McClintock

 * Maintainer: Kumar Gala <galak@kernel.crashing.org>

 *

 * Copyright 2005 Freescale Semiconductor Inc.

 * Copyright 2005, 2008 Freescale Semiconductor Inc.

 *

 * 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
@@ -16,6 +14,7 @@ 


#include <linux/module.h>

#include <linux/fs.h>

#include <linux/smp.h>

#include <linux/miscdevice.h>

#include <linux/notifier.h>

#include <linux/watchdog.h>
@@ -38,7 +37,7 @@ 
#define WDT_PERIOD_DEFAULT 3	/* Refer to the PPC40x and PPC4xx manuals */

#endif				/* for timing information */



u32 booke_wdt_enabled = 0;

u32 booke_wdt_enabled;

u32 booke_wdt_period = WDT_PERIOD_DEFAULT;



#ifdef	CONFIG_FSL_BOOKE
@@ -47,32 +46,30 @@ u32 booke_wdt_period = WDT_PERIOD_DEFAULT; 
#define WDTP(x)		(TCR_WP(x))

#endif



/*

 * booke_wdt_ping:

 */

static __inline__ void booke_wdt_ping(void)

static DEFINE_SPINLOCK(booke_wdt_lock);



static void __booke_wdt_ping(void *data)

{

	mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);

}



/*

 * booke_wdt_enable:

 */

static __inline__ void booke_wdt_enable(void)

static void booke_wdt_ping(void)

{

	on_each_cpu(__booke_wdt_ping, NULL, 0, 0);

}



static void __booke_wdt_enable(void *data)

{

	u32 val;



	/* clear status before enabling watchdog */

	booke_wdt_ping();

	__booke_wdt_ping(NULL);

	val = mfspr(SPRN_TCR);

	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));



	mtspr(SPRN_TCR, val);

}



/*

 * booke_wdt_write:

 */

static ssize_t booke_wdt_write(struct file *file, const char __user *buf,

				size_t count, loff_t *ppos)

{
@@ -82,13 +79,9 @@ static ssize_t booke_wdt_write (struct file *file, const char __user *buf, 


static struct watchdog_info ident = {

	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

  .firmware_version = 0,

	.identity = "PowerPC Book-E Watchdog",

};



/*

 * booke_wdt_ioctl:

 */

static int booke_wdt_ioctl(struct inode *inode, struct file *file,

			    unsigned int cmd, unsigned long arg)

{
@@ -132,17 +125,17 @@ static int booke_wdt_ioctl (struct inode *inode, struct file *file, 


	return 0;

}

/*

 * booke_wdt_open:

 */



static int booke_wdt_open(struct inode *inode, struct file *file)

{

	spin_lock(&booke_wdt_lock);

	if (booke_wdt_enabled == 0) {

		booke_wdt_enabled = 1;

		booke_wdt_enable();

		printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",

				booke_wdt_period);

		on_each_cpu(__booke_wdt_enable, NULL, 0, 0);

		printk(KERN_INFO "PowerPC Book-E Watchdog Timer Enabled "

				"(wdt_period=%d)\n", booke_wdt_period);

	}

	spin_unlock(&booke_wdt_lock);



	return nonseekable_open(inode, file);

}
@@ -166,9 +159,6 @@ static void __exit booke_wdt_exit(void) 
	misc_deregister(&booke_wdt_miscdev);

}



/*

 * booke_wdt_init:

 */

static int __init booke_wdt_init(void)

{

	int ret = 0;
@@ -178,16 +168,18 @@ static int __init booke_wdt_init(void) 


	ret = misc_register(&booke_wdt_miscdev);

	if (ret) {

		printk (KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n",

		printk(KERN_CRIT "Cannot register miscdev on minor=%d: %d\n",

				WATCHDOG_MINOR, ret);

		return ret;

	}



	spin_lock(&booke_wdt_lock);

	if (booke_wdt_enabled == 1) {

		printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",

				booke_wdt_period);

		booke_wdt_enable();

		printk(KERN_INFO "PowerPC Book-E Watchdog Timer Enabled "

				"(wdt_period=%d)\n", booke_wdt_period);

		on_each_cpu(__booke_wdt_enable, NULL, 0, 0);

	}

	spin_unlock(&booke_wdt_lock);



	return ret;

}