ipmi_watchdog.c

h内核

/*
 * ipmi_watchdog.c
 *
 * A watchdog timer based upon the IPMI interface.
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <[e-mail]>
 *         [e-mail]
 *
 * 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/config.h>
#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/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>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
#endif

#define	PFX "IPMI Watchdog: "

#define IPMI_WATCHDOG_VERSION "v33"

/*
 * 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

#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout;
#endif

static ipmi_user_t watchdog_user = NULL;

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

/* The pre-timeout is disabled by default. */
static int pretimeout = 0;

/* 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 = 0;
static DECLARE_WAIT_QUEUE_HEAD(read_q);
static struct fasync_struct *fasync_q = NULL;
static char pretimeout_since_last_heartbeat = 0;
static char expect_close;

/* If true, the driver will start running as soon as it is configured
   and ready. */
static int start_now = 0;

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Timeout value in seconds.");
module_param(pretimeout, int, 0);
MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
module_param_string(action, action, sizeof(action), 0);
MODULE_PARM_DESC(action, "Timeout action. One of: "
		 "reset, none, power_cycle, power_off.");
module_param_string(preaction, preaction, sizeof(preaction), 0);
MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
		 "pre_none, pre_smi, pre_nmi, pre_int.");
module_param_string(preop, preop, sizeof(preop), 0);
MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
		 "preop_none, preop_panic, preop_give_data.");
module_param(start_now, int, 0);
MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as"
		 "soon as the driver is loaded.");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/* Default state of the timer. */
static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE;

/* If shutting down via IPMI, we ignore the heartbeat. */
static int ipmi_ignore_heartbeat = 0;

/* Is someone using the watchdog?  Only one user is allowed. */
static unsigned long ipmi_wdog_open = 0;

/* If set to 1, the heartbeat command will set the state to reset and
   start the timer.  The timer doesn't normally run when the driver is
   first opened until the heartbeat is set the first time, this
   variable is used to accomplish this. */
static int ipmi_start_timer_on_heartbeat = 0;

/* IPMI version of the BMC. */
static unsigned char ipmi_version_major;
static unsigned char ipmi_version_minor;


static int ipmi_heartbeat(void);
static void panic_halt_ipmi_heartbeat(void);


/* We use a semaphore to make sure that only one thing can send a set
   timeout at one time, because we only have one copy of the data.
   The semaphore is claimed when the set_timeout is sent and freed
   when both messages are free. */
static atomic_t set_timeout_tofree = ATOMIC_INIT(0);
static DECLARE_MUTEX(set_timeout_lock);
static void set_timeout_free_smi(struct ipmi_smi_msg *msg)
{
    if (atomic_dec_and_test(&set_timeout_tofree))
	    up(&set_timeout_lock);
}
static void set_timeout_free_recv(struct ipmi_recv_msg *msg)
{
    if (atomic_dec_and_test(&set_timeout_tofree))
	    up(&set_timeout_lock);
}
static struct ipmi_smi_msg set_timeout_smi_msg =
{
	.done = set_timeout_free_smi
};
static struct ipmi_recv_msg set_timeout_recv_msg =
{
	.done = set_timeout_free_recv
};
 
static int i_ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,
			      struct ipmi_recv_msg *recv_msg,
			      int                  *send_heartbeat_now)
{
	struct kernel_ipmi_msg            msg;
	unsigned char                     data[6];
	int                               rv;
	struct ipmi_system_interface_addr addr;
	int                               hbnow = 0;


	data[0] = 0;
	WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);

	if ((ipmi_version_major > 1)
	    || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5)))
	{
		/* This is an IPMI 1.5-only feature. */
		data[0] |= WDOG_DONT_STOP_ON_SET;
	} else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {
		/* In ipmi 1.0, setting the timer stops the watchdog, we
		   need to start it back up again. */
		hbnow = 1;
	}

	data[1] = 0;
	WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state);
	if (pretimeout > 0) {
	    WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val);
	    data[2] = pretimeout;
	} else {
	    WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE);
	    data[2] = 0; /* No pretimeout. */
	}
	data[3] = 0;
	WDOG_SET_TIMEOUT(data[4], data[5], timeout);

	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
	addr.channel = IPMI_BMC_CHANNEL;
	addr.lun = 0;

	msg.netfn = 0x06;
	msg.cmd = IPMI_WDOG_SET_TIMER;
	msg.data = data;
	msg.data_len = sizeof(data);
	rv = ipmi_request_supply_msgs(watchdog_user,
				      (struct ipmi_addr *) &addr,
				      0,
				      &msg,
				      NULL,
				      smi_msg,
				      recv_msg,
				      1);
	if (rv) {
		printk(KERN_WARNING PFX "set timeout error: %d\n",
		       rv);
	}

	if (send_heartbeat_now)
	    *send_heartbeat_now = hbnow;

	return rv;
}

/* Parameters to ipmi_set_timeout */
#define IPMI_SET_TIMEOUT_NO_HB			0
#define IPMI_SET_TIMEOUT_HB_IF_NECESSARY	1
#define IPMI_SET_TIMEOUT_FORCE_HB		2

static int ipmi_set_timeout(int do_heartbeat)
{
	int send_heartbeat_now;
	int rv;


	/* We can only send one of these at a time. */
	down(&set_timeout_lock);

	atomic_set(&set_timeout_tofree, 2);

	rv = i_ipmi_set_timeout(&set_timeout_smi_msg,
				&set_timeout_recv_msg,
				&send_heartbeat_now);
	if (rv) {
		up(&set_timeout_lock);
	} else {
		if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)
		    || ((send_heartbeat_now)
			&& (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))
		{
			rv = ipmi_heartbeat();
		}
	}

	return rv;
}

static void dummy_smi_free(struct ipmi_smi_msg *msg)
{
}
static void dummy_recv_free(struct ipmi_recv_msg *msg)
{
}
static struct ipmi_smi_msg panic_halt_smi_msg =
{
	.done = dummy_smi_free
};
static struct ipmi_recv_msg panic_halt_recv_msg =
{
	.done = dummy_recv_free
};

/* Special call, doesn't claim any locks.  This is only to be called
   at panic or halt time, in run-to-completion mode, when the caller
   is the only CPU and the only thing that will be going is these IPMI
   calls. */
static void panic_halt_ipmi_set_timeout(void)
{
	int send_heartbeat_now;
	int rv;

	rv = i_ipmi_set_timeout(&panic_halt_smi_msg,
				&panic_halt_recv_msg,
				&send_heartbeat_now);
	if (!rv) {
		if (send_heartbeat_now)
			panic_halt_ipmi_heartbeat();
	}
}

/* We use a semaphore to make sure that only one thing can send a
   heartbeat at one time, because we only have one copy of the data.
   The semaphore is claimed when the set_timeout is sent and freed
   when both messages are free. */
static atomic_t heartbeat_tofree = ATOMIC_INIT(0);
static DECLARE_MUTEX(heartbeat_lock);
static DECLARE_MUTEX_LOCKED(heartbeat_wait_lock);
static void heartbeat_free_smi(struct ipmi_smi_msg *msg)
{
    if (atomic_dec_and_test(&heartbeat_tofree))
	    up(&heartbeat_wait_lock);
}
static void heartbeat_free_recv(struct ipmi_recv_msg *msg)
{
    if (atomic_dec_and_test(&heartbeat_tofree))
	    up(&heartbeat_wait_lock);
}
static struct ipmi_smi_msg heartbeat_smi_msg =
{
	.done = heartbeat_free_smi
};
static struct ipmi_recv_msg heartbeat_recv_msg =
{
	.done = heartbeat_free_recv
};
 
static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg =
{
	.done = dummy_smi_free
};
static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg =
{
	.done = dummy_recv_free
};
 
static int ipmi_heartbeat(void)
{
	struct kernel_ipmi_msg            msg;
	int                               rv;
	struct ipmi_system_interface_addr addr;

	if (ipmi_ignore_heartbeat) {
		return 0;
	}

	if (ipmi_start_timer_on_heartbeat) {
		ipmi_start_timer_on_heartbeat = 0;
		ipmi_watchdog_state = action_val;
		return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);
	} else if (pretimeout_since_last_heartbeat) {
		/* A pretimeout occurred, make sure we set the timeout.
		   We don't want to set the action, though, we want to
		   leave that alone (thus it can't be combined with the
		   above operation. */
		pretimeout_since_last_heartbeat = 0;
		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);
	}

	down(&heartbeat_lock);

	atomic_set(&heartbeat_tofree, 2);

	/* Don't reset the timer if we have the timer turned off, that
           re-enables the watchdog. */
	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) {
		up(&heartbeat_lock);
		return 0;
	}

	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
	addr.channel = IPMI_BMC_CHANNEL;
	addr.lun = 0;

	msg.netfn = 0x06;
	msg.cmd = IPMI_WDOG_RESET_TIMER;
	msg.data = NULL;
	msg.data_len = 0;
	rv = ipmi_request_supply_msgs(watchdog_user,
				      (struct ipmi_addr *) &addr,
				      0,
				      &msg,
				      NULL,
				      &heartbeat_smi_msg,
				      &heartbeat_recv_msg,
				      1);
	if (rv) {
		up(&heartbeat_lock);
		printk(KERN_WARNING PFX "heartbeat failure: %d\n",
		       rv);
		return rv;
	}

	/* Wait for the heartbeat to be sent. */
	down(&heartbeat_wait_lock);

	if (heartbeat_recv_msg.msg.data[0] != 0) {
	    /* Got an error in the heartbeat response.  It was already
	       reported in ipmi_wdog_msg_handler, but we should return
	       an error here. */
	    rv = -EINVAL;
	}

	up(&heartbeat_lock);

	return rv;
}

static void panic_halt_ipmi_heartbeat(void)
{
	struct kernel_ipmi_msg             msg;
	struct ipmi_system_interface_addr addr;


	/* Don't reset the timer if we have the timer turned off, that
           re-enables the watchdog. */
	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)
		return;

	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
	addr.channel = IPMI_BMC_CHANNEL;
	addr.lun = 0;

	msg.netfn = 0x06;
	msg.cmd = IPMI_WDOG_RESET_TIMER;
	msg.data = NULL;
	msg.data_len = 0;
	ipmi_request_supply_msgs(watchdog_user,
				 (struct ipmi_addr *) &addr,
				 0,
				 &msg,
				 NULL,
				 &panic_halt_heartbeat_smi_msg,
				 &panic_halt_heartbeat_recv_msg,
				 1);
}

static struct watchdog_info ident=
{
	.options	= 0,	/* WDIOF_SETTIMEOUT, */
	.firmware_version = 1,
	.identity	= "IPMI"
};

static int ipmi_ioctl(struct inode *inode, struct file *file,
		      unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int i;
	int val;

	switch(cmd) {
	case WDIOC_GETSUPPORT:
		i = copy_to_user(argp, &ident, sizeof(ident));
		return i ? -EFAULT : 0;

	case WDIOC_SETTIMEOUT:
		i = copy_from_user(&val, argp, sizeof(int));
		if (i)
			return -EFAULT;
		timeout = val;
		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);

	case WDIOC_GETTIMEOUT:
		i = copy_to_user(argp, &timeout, sizeof(timeout));
		if (i)
			return -EFAULT;
		return 0;