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 <asm/atomic.h>

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
#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] = "reset";

static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE;

static char preaction[16] = "pre_none";

static unsigned char preop_val = WDOG_PREOP_NONE;

static char preop[16] = "preop_none";
static DEFINE_SPINLOCK(ipmi_read_lock);
static char data_to_read;
static DECLARE_WAIT_QUEUE_HEAD(read_q);
static struct fasync_struct *fasync_q;
static char pretimeout_since_last_heartbeat;
static char expect_close;

static int i