path: root/drivers/char/ipmi/ipmi_watchdog.c

/*
 * ipmi_watchdog.c
 *
 * A watchdog timer based upon the IPMI interface.
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <minyard@mvista.com>
 *         source@mvista.com
 *
 * Copyright 2002 MontaVista Software 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
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/kdebug.h>
#include <linux/rwsem.h>
#include <linux/errno.h>
#include <asm/uaccess.h>
#include <linux/notifier.h>
#include <linux/nmi.h>
#include <linux/reboot.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <asm/atomic.h>

#ifdef CONFIG_X86
/* This is ugly, but I've determined that x86 is the only architecture
   that can reasonably support the IPMI NMI watchdog timeout at this
   time.  If another architecture adds this capability somehow, it
   will have to be a somewhat different mechanism and I have no idea
   how it will work.  So in the unlikely event that another
   architecture supports this, we can figure out a good generic
   mechanism for it at that time. */
#include <asm/kdebug.h>
#define HAVE_DIE_NMI_POST
#endif

#define	PFX "IPMI Watchdog: "

/*
 * The IPMI command/response information for the watchdog timer.
 */

/* values for byte 1 of the set command, byte 2 of the get response. */
#define WDOG_DONT_LOG		(1 << 7)
#define WDOG_DONT_STOP_ON_SET	(1 << 6)
#define WDOG_SET_TIMER_USE(byte, use) \
	byte = ((byte) & 0xf8) | ((use) & 0x7)
#define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7)
#define WDOG_TIMER_USE_BIOS_FRB2	1
#define WDOG_TIMER_USE_BIOS_POST	2
#define WDOG_TIMER_USE_OS_LOAD		3
#define WDOG_TIMER_USE_SMS_OS		4
#define WDOG_TIMER_USE_OEM		5

/* values for byte 2 of the set command, byte 3 of the get response. */
#define WDOG_SET_PRETIMEOUT_ACT(byte, use) \
	byte = ((byte) & 0x8f) | (((use) & 0x7) << 4)
#define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7)
#define WDOG_PRETIMEOUT_NONE		0
#define WDOG_PRETIMEOUT_SMI		1
#define WDOG_PRETIMEOUT_NMI		2
#define WDOG_PRETIMEOUT_MSG_INT		3

/* Operations that can be performed on a pretimout. */
#define WDOG_PREOP_NONE		0
#define WDOG_PREOP_PANIC	1
#define WDOG_PREOP_GIVE_DATA	2 /* Cause data to be available to
                                     read.  Doesn't work in NMI
                                     mode. */

/* Actions to perform on a full timeout. */
#define WDOG_SET_TIMEOUT_ACT(byte, use) \
	byte = ((byte) & 0xf8) | ((use) & 0x7)
#define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7)
#define WDOG_TIMEOUT_NONE		0
#define WDOG_TIMEOUT_RESET		1
#define WDOG_TIMEOUT_POWER_DOWN		2
#define WDOG_TIMEOUT_POWER_CYCLE	3

/* Byte 3 of the get command, byte 4 of the get response is the
   pre-timeout in seconds. */

/* Bits for setting byte 4 of the set command, byte 5 of the get response. */
#define WDOG_EXPIRE_CLEAR_BIOS_FRB2	(1 << 1)
#define WDOG_EXPIRE_CLEAR_BIOS_POST	(1 << 2)
#define WDOG_EXPIRE_CLEAR_OS_LOAD	(1 << 3)
#define WDOG_EXPIRE_CLEAR_SMS_OS	(1 << 4)
#define WDOG_EXPIRE_CLEAR_OEM		(1 << 5)

/* Setting/getting the watchdog timer value.  This is for bytes 5 and
   6 (the timeout time) of the set command, and bytes 6 and 7 (the
   timeout time) and 8 and 9 (the current countdown value) of the
   response.  The timeout value is given in seconds (in the command it
   is 100ms intervals). */
#define WDOG_SET_TIMEOUT(byte1, byte2, val) \
	(byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8)
#define WDOG_GET_TIMEOUT(byte1, byte2) \
	(((byte1) | ((byte2) << 8)) / 10)

#define IPMI_WDOG_RESET_TIMER		0x22
#define IPMI_WDOG_SET_TIMER		0x24
#define IPMI_WDOG_GET_TIMER		0x25

/* These are here until the real ones get into the watchdog.h interface. */
#ifndef WDIOC_GETTIMEOUT
#define	WDIOC_GETTIMEOUT        _IOW(WATCHDOG_IOCTL_BASE, 20, int)
#endif
#ifndef WDIOC_SET_PRETIMEOUT
#define	WDIOC_SET_PRETIMEOUT     _IOW(WATCHDOG_IOCTL_BASE, 21, int)
#endif
#ifndef WDIOC_GET_PRETIMEOUT
#define	WDIOC_GET_PRETIMEOUT     _IOW(WATCHDOG_IOCTL_BASE, 22, int)
#endif

static int nowayout = WATCHDOG_NOWAYOUT;

static ipmi_user_t watchdog_user;
static int watchdog_ifnum;

/* Default the timeout to 10 seconds. */
static int timeout = 10;

/* The pre-timeout is disabled by default. */
static int pretimeout;

/* Default action is to reset the board on a timeout. */
static unsigned char action_val = WDOG_TIMEOUT_RESET;

static char action[16] = &