dev/sysmon/sysmon.c

/*	$NetBSD: sysmon.c,v 1.3 2000/11/04 18:37:19 thorpej Exp $	*/

/*-
 * Copyright (c) 2000 Zembu Labs, Inc.
 * All rights reserved.
 *
 * Author: Jason R. Thorpe <thorpej (at) zembu.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Zembu Labs, Inc.
 * 4. Neither the name of Zembu Labs nor the names of its employees may
 *    be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR-
 * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS-
 * CLAIMED.  IN NO EVENT SHALL ZEMBU LABS 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.
 */

/*
 * Clearing house for system monitoring hardware.  This pseudo-device
 * is a place where hardware monitors such as the LM78 and VIA 82C686A
 * (or even ACPI, eventually) can register themselves to provide
 * backplane fan and temperature information, etc.  It also provides
 * a place to register watchdog timers, and provides an abstract
 * interface to them.
 */

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>

#include <dev/sysmon/sysmonvar.h>

/*
 * We run at ENVSYS version 1.
 */
#define	SYSMON_ENVSYS_VERSION	(1 * 1000)

struct lock sysmon_envsys_lock;

LIST_HEAD(, sysmon_envsys) sysmon_envsys_list =
    LIST_HEAD_INITIALIZER(&sysmon_envsys_list);
struct simplelock sysmon_envsys_list_slock = SIMPLELOCK_INITIALIZER;
u_int	sysmon_envsys_next_sensor_index;

int	sysmon_envsys_initialized;
struct simplelock sysmon_envsys_initialized_slock = SIMPLELOCK_INITIALIZER;

cdev_decl(sysmon);

void	sysmon_envsys_init(void);

int	sysmonioctl_envsys(dev_t, u_long, caddr_t, int, struct proc *);
int	sysmonioctl_wdog(dev_t, u_long, caddr_t, int, struct proc *);

struct sysmon_envsys *sysmon_envsys_find(u_int);
void	sysmon_envsys_release(struct sysmon_envsys *);

LIST_HEAD(, sysmon_wdog) sysmon_wdog_list =
    LIST_HEAD_INITIALIZER(&sysmon_wdog_list);
int sysmon_wdog_count;
struct simplelock sysmon_wdog_list_slock = SIMPLELOCK_INITIALIZER;

struct simplelock sysmon_wdog_slock = SIMPLELOCK_INITIALIZER;
struct sysmon_wdog *sysmon_armed_wdog;
struct callout sysmon_wdog_callout = CALLOUT_INITIALIZER;
void *sysmon_wdog_sdhook;

#define	SYSMON_WDOG_LOCK(s)						\
do {									\
	s = splsoftclock();						\
	simple_lock(&sysmon_wdog_slock);				\
} while (0)

#define	SYSMON_WDOG_UNLOCK(s)						\
do {									\
	simple_unlock(&sysmon_wdog_slock);				\
	splx(s);							\
} while (0)

struct sysmon_wdog *sysmon_wdog_find(const char *);
void	sysmon_wdog_release(struct sysmon_wdog *);
int	sysmon_wdog_setmode(struct sysmon_wdog *, int, u_int);
void	sysmon_wdog_ktickle(void *);
void	sysmon_wdog_shutdown(void *);

#define	SYSMON_MINOR_ENVSYS	0
#define	SYSMON_MINOR_WDOG	1

/*
 * sysmon_envsys_init:
 *
 *	Initialize the system monitor.
 */
void
sysmon_envsys_init(void)
{

	lockinit(&sysmon_envsys_lock, PWAIT|PCATCH, "smenv", 0, 0);
	sysmon_envsys_initialized = 1;
}

/*
 * sysmonopen:
 *
 *	Open the system monitor device.
 */
int
sysmonopen(dev_t dev, int flag, int mode, struct proc *p)
{
	int error = 0;

	switch (minor(dev)) {
	case SYSMON_MINOR_ENVSYS:
		simple_lock(&sysmon_envsys_initialized_slock);
		if (sysmon_envsys_initialized == 0)
			sysmon_envsys_init();

		error = lockmgr(&sysmon_envsys_lock,
		    LK_EXCLUSIVE | LK_INTERLOCK |
		    ((flag & O_NONBLOCK) ? LK_NOWAIT : 0),
		    &sysmon_envsys_initialized_slock);
		break;

	case SYSMON_MINOR_WDOG:
		simple_lock(&sysmon_wdog_list_slock);
		if (sysmon_wdog_sdhook == NULL) {
			sysmon_wdog_sdhook =
			    shutdownhook_establish(sysmon_wdog_shutdown, NULL);
			if (sysmon_wdog_sdhook == NULL)
				printf("WARNING: unable to register watchdog "
				    "shutdown hook\n");
		}
		simple_unlock(&sysmon_wdog_list_slock);
		break;

	default:
		error = ENODEV;
	}

	return (error);
}

/*
 * sysmonclose:
 *
 *	Close the system monitor device.
 */
int
sysmonclose(dev_t dev, int flag, int mode, struct proc *p)
{
	int error = 0;

	switch (minor(dev)) {
	case SYSMON_MINOR_ENVSYS:
		(void) lockmgr(&sysmon_envsys_lock, LK_RELEASE, NULL);
		break;

	case SYSMON_MINOR_WDOG:
	    {
		struct sysmon_wdog *smw;
		int omode, s;

		/*
		 * If this is the last close, and there is a watchdog
		 * running in UTICKLE mode, we need to disable it,
		 * otherwise the system will reset in short order.
		 *
		 * XXX Maybe we should just go into KTICKLE mode?
		 */
		SYSMON_WDOG_LOCK(s);
		if ((smw = sysmon_armed_wdog) != NULL) {
			if ((omode = smw->smw_mode) == WDOG_MODE_UTICKLE) {
				error = sysmon_wdog_setmode(smw,
				    WDOG_MODE_DISARMED, smw->smw_period);
				if (error) {
					printf("WARNING: UNABLE TO DISARM "
					    "WATCHDOG %s ON CLOSE!\n",
					    smw->smw_name);
					/*
					 * ...we will probably reboot soon.
					 */
				}
			}
		}
		SYSMON_WDOG_UNLOCK(s);
		break;
	    }

	default:
		error = ENODEV;
	}

	return (error);
}

/*
 * sysmonioctl:
 *
 *	Perform a control request.
 */
int
sysmonioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
{
	int error;

	switch (minor(dev)) {
	case SYSMON_MINOR_ENVSYS:
		error = sysmonioctl_envsys(dev, cmd, data, flag, p);
		break;

	case SYSMON_MINOR_WDOG:
		error = sysmonioctl_wdog(dev, cmd, data, flag, p);
		break;

	default:
		error = ENODEV;
	}

	return (error);
}

/*
 * sysmonioctl_envsys:
 *
 *	Perform an envsys control request.
 */
int
sysmonioctl_envsys(dev_t dev, u_long cmd, caddr_t data, int flag,
    struct proc *p)
{
	struct sysmon_envsys *sme;
	int error = 0;
	u_int oidx;

	switch (cmd) {
	/*
	 * For ENVSYS commands, we translate the absolute sensor index
	 * to a device-relative sensor index.
	 */
	case ENVSYS_VERSION:
		*(int32_t *)data = SYSMON_ENVSYS_VERSION;
		break;

	case ENVSYS_GRANGE:
	    {
		struct envsys_range *rng = (void *) data;

		sme = sysmon_envsys_find(0);	/* XXX */
		if (sme == NULL) {
			/* Return empty range for `no sensors'. */
			rng->low = 1;
			rng->high = 0;
			break;
		}

		if (rng->units < ENVSYS_NSENSORS)
			*rng = sme->sme_ranges[rng->units];
		else {
			/* Return empty range for unsupported sensor types. */
			rng->low = 1;
			rng->high = 0;
		}
		sysmon_envsys_release(sme);
		break;
	    }

	case ENVSYS_GTREDATA:
	    {
		struct envsys_tre_data *tred = (void *) data;

		tred->validflags = 0;

		sme = sysmon_envsys_find(tred->sensor);
		if (sme == NULL)
			break;
		oidx = tred->sensor;
		tred->sensor = SME_SENSOR_IDX(sme, tred->sensor);
		if (tred->sensor < sme->sme_nsensors)
			error = (*sme->sme_gtredata)(sme, tred);
		tred->sensor = oidx;
		sysmon_envsys_release(sme);
		break;
	    }

	case ENVSYS_STREINFO:
	    {
		struct envsys_basic_info *binfo = (void *) data;

		sme = sysmon_envsys_find(binfo->sensor);
		if (sme == NULL) {
			binfo->validflags = 0;
			break;
		}
		oidx = binfo->sensor;
		binfo->sensor = SME_SENSOR_IDX(sme, binfo->sensor);
		if (binfo->sensor < sme->sme_nsensors)
			error = (*sme->sme_streinfo)(sme, binfo);
		else
			binfo->validflags = 0;
		binfo->sensor = oidx;
		sysmon_envsys_release(sme);
		break;
	    }

	case ENVSYS_GTREINFO:
	    {
		struct envsys_basic_info *binfo = (void *) data;

		binfo->validflags = 0;

		sme = sysmon_envsys_find(binfo->sensor);
		if (sme == NULL)
			break;
		oidx = binfo->sensor;
		binfo->sensor = SME_SENSOR_IDX(sme, binfo->sensor);
		if (binfo->sensor < sme->sme_nsensors)
			*binfo = sme->sme_sensor_info[binfo->sensor];
		binfo->sensor = oidx;
		sysmon_envsys_release(sme);
		break;
	    }

	default:
		error = ENOTTY;
	}

	return (error);
}

/*
 * sysmonioctl_wdog:
 *
 *	Perform a watchdog control request.
 */
int
sysmonioctl_wdog(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
{
	struct sysmon_wdog *smw;
	int s, error = 0;

	switch (cmd) {
	case WDOGIOC_GMODE:
	    {
		struct wdog_mode *wm = (void *) data;

		wm->wm_name[sizeof(wm->wm_name) - 1] = '\0';
		smw = sysmon_wdog_find(wm->wm_name);
		if (smw == NULL) {
			error = ESRCH;
			break;
		}

		wm->wm_mode = smw->smw_mode;
		wm->wm_period = smw->smw_period;
		sysmon_wdog_release(smw);
		break;
	    }

	case WDOGIOC_SMODE:
	    {
		struct wdog_mode *wm = (void *) data;

		if ((flag & FWRITE) == 0) {
			error = EPERM;
			break;
		}

		wm->wm_name[sizeof(wm->wm_name) - 1] = '\0';
		smw = sysmon_wdog_find(wm->wm_name);
		if (smw == NULL) {
			error = ESRCH;
			break;
		}

		if (wm->wm_mode & ~(WDOG_MODE_MASK|WDOG_FEATURE_MASK))
			error = EINVAL;
		else {
			SYSMON_WDOG_LOCK(s);
			error = sysmon_wdog_setmode(smw, wm->wm_mode,
			    wm->wm_period);
			SYSMON_WDOG_UNLOCK(s);
		}

		sysmon_wdog_release(smw);
		break;
	    }

	case WDOGIOC_WHICH:
	    {
		struct wdog_mode *wm = (void *) data;

		SYSMON_WDOG_LOCK(s);
		if ((smw = sysmon_armed_wdog) != NULL) {
			strcpy(wm->wm_name, smw->smw_name);
			wm->wm_mode = smw->smw_mode;
			wm->wm_period = smw->smw_period;
		} else
			error = ESRCH;
		SYSMON_WDOG_UNLOCK(s);
		break;
	    }

	case WDOGIOC_TICKLE:
		if ((flag & FWRITE) == 0) {
			error = EPERM;
			break;
		}

		SYSMON_WDOG_LOCK(s);
		if ((smw = sysmon_armed_wdog) != NULL) {
			error = (*smw->smw_tickle)(smw);
			if (error == 0)
				smw->smw_tickler = p->p_pid;
		} else
			error = ESRCH;
		SYSMON_WDOG_UNLOCK(s);
		break;

	case WDOGIOC_GTICKLER:
		*(pid_t *)data = smw->smw_tickler;
		break;

	case WDOGIOC_GWDOGS:
	    {
		struct wdog_conf *wc = (void *) data;
		char *cp;
		int i;

		simple_lock(&sysmon_wdog_list_slock);
		if (wc->wc_names == NULL)
			wc->wc_count = sysmon_wdog_count;
		else {
			for (i = 0, cp = wc->wc_names,
			       smw = LIST_FIRST(&sysmon_wdog_list);
			     i < sysmon_wdog_count && smw != NULL && error == 0;
			     i++, cp += WDOG_NAMESIZE,
			       smw = LIST_NEXT(smw, smw_list))
				error = copyout(smw->smw_name, cp,
				    strlen(smw->smw_name) + 1);
			wc->wc_count = i;
		}
		simple_unlock(&sysmon_wdog_list_slock);
		break;
	    }

	default:
		error = ENOTTY;
	}

	return (error);
}

/*
 * sysmon_envsys_register:
 *
 *	Register an ENVSYS device.
 */
int
sysmon_envsys_register(struct sysmon_envsys *sme)
{
	int error = 0;

	simple_lock(&sysmon_envsys_list_slock);

	/* XXX Only get to register one, for now. */
	if (LIST_FIRST(&sysmon_envsys_list) != NULL) {
		error = EEXIST;
		goto out;
	}

	if (sme->sme_envsys_version != SYSMON_ENVSYS_VERSION) {
		error = EINVAL;
		goto out;
	}

	sme->sme_fsensor = sysmon_envsys_next_sensor_index;
	sysmon_envsys_next_sensor_index += sme->sme_nsensors;
	LIST_INSERT_HEAD(&sysmon_envsys_list, sme, sme_list);

 out:
	simple_unlock(&sysmon_envsys_list_slock);
	return (error);
}

/*
 * sysmon_envsys_unregister:
 *
 *	Unregister an ENVSYS device.
 */
void
sysmon_envsys_unregister(struct sysmon_envsys *sme)
{

	simple_lock(&sysmon_envsys_list_slock);
	LIST_REMOVE(sme, sme_list);
	simple_unlock(&sysmon_envsys_list_slock);
}

/*
 * sysmon_envsys_find:
 *
 *	Find an ENVSYS device.  The list remains locked upon
 *	a match.
 */
struct sysmon_envsys *
sysmon_envsys_find(u_int idx)
{
	struct sysmon_envsys *sme;

	simple_lock(&sysmon_envsys_list_slock);

	for (sme = LIST_FIRST(&sysmon_envsys_list); sme != NULL;
	     sme = LIST_NEXT(sme, sme_list)) {
		if (idx >= sme->sme_fsensor &&
		    idx < (sme->sme_fsensor + sme->sme_nsensors))
			return (sme);
	}

	simple_unlock(&sysmon_envsys_list_slock);
	return (NULL);
}

/*
 * sysmon_envsys_release:
 *
 *	Release an ENVSYS device.
 */
/* ARGSUSED */
void
sysmon_envsys_release(struct sysmon_envsys *sme)
{

	simple_unlock(&sysmon_envsys_list_slock);
}

/*
 * sysmon_wdog_register:
 *
 *	Register a watchdog device.
 */
int
sysmon_wdog_register(struct sysmon_wdog *smw)
{
	struct sysmon_wdog *lsmw;
	int error = 0;

	simple_lock(&sysmon_wdog_list_slock);

	for (lsmw = LIST_FIRST(&sysmon_wdog_list); lsmw != NULL;
	     lsmw = LIST_NEXT(lsmw, smw_list)) {
		if (strcmp(lsmw->smw_name, smw->smw_name) == 0) {
			error = EEXIST;
			goto out;
		}
	}

	smw->smw_mode = WDOG_MODE_DISARMED;
	smw->smw_tickler = (pid_t) -1;
	smw->smw_refcnt = 0;
	sysmon_wdog_count++;
	LIST_INSERT_HEAD(&sysmon_wdog_list, smw, smw_list);

 out:
	simple_unlock(&sysmon_wdog_list_slock);
	return (error);
}

/*
 * sysmon_wdog_unregister:
 *
 *	Unregister a watchdog device.
 */
void
sysmon_wdog_unregister(struct sysmon_wdog *smw)
{

	simple_lock(&sysmon_wdog_list_slock);
	sysmon_wdog_count--;
	LIST_REMOVE(smw, smw_list);
	simple_unlock(&sysmon_wdog_list_slock);
}

/*
 * sysmon_wdog_find:
 *
 *	Find a watchdog device.  We increase the reference
 *	count on a match.
 */
struct sysmon_wdog *
sysmon_wdog_find(const char *name)
{
	struct sysmon_wdog *smw;

	simple_lock(&sysmon_wdog_list_slock);

	for (smw = LIST_FIRST(&sysmon_wdog_list); smw != NULL;
	     smw = LIST_NEXT(smw, smw_list)) {
		if (strcmp(smw->smw_name, name) == 0)
			break;
	}

	if (smw != NULL)
		smw->smw_refcnt++;

	simple_unlock(&sysmon_wdog_list_slock);
	return (smw);
}

/*
 * sysmon_wdog_release:
 *
 *	Release a watchdog device.
 */
void
sysmon_wdog_release(struct sysmon_wdog *smw)
{

	simple_lock(&sysmon_wdog_list_slock);
	KASSERT(smw->smw_refcnt != 0);
	smw->smw_refcnt--;
	simple_unlock(&sysmon_wdog_list_slock);
}

/*
 * sysmon_wdog_setmode:
 *
 *	Set the mode of a watchdog device.
 */
int
sysmon_wdog_setmode(struct sysmon_wdog *smw, int mode, u_int period)
{
	u_int operiod = smw->smw_period;
	int omode = smw->smw_mode;
	int error = 0;

	smw->smw_period = period;
	smw->smw_mode = mode;

	switch (mode & WDOG_MODE_MASK) {
	case WDOG_MODE_DISARMED:
		if (smw != sysmon_armed_wdog) {
			error = EINVAL;
			goto out;
		}
		break;

	case WDOG_MODE_KTICKLE:
	case WDOG_MODE_UTICKLE:
		if (sysmon_armed_wdog != NULL) {
			error = EBUSY;
			goto out;
		}
		break;

	default:
		error = EINVAL;
		goto out;
	}

	error = (*smw->smw_setmode)(smw);

 out:
	if (error) {
		smw->smw_period = operiod;
		smw->smw_mode = omode;
	} else {
		if ((mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
			smw->smw_tickler = (pid_t) -1;
			smw->smw_refcnt--;
			if ((omode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE)
				callout_stop(&sysmon_wdog_callout);
		} else {
			sysmon_armed_wdog = smw;
			smw->smw_refcnt++;
			if ((mode & WDOG_MODE_MASK) == WDOG_MODE_KTICKLE) {
				callout_reset(&sysmon_wdog_callout,
				    WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2,
				    sysmon_wdog_ktickle, NULL);
			}
		}
	}
	return (error);
}

/*
 * sysmon_wdog_ktickle:
 *
 *	Kernel watchdog tickle routine.
 */
void
sysmon_wdog_ktickle(void *arg)
{
	struct sysmon_wdog *smw;
	int s;

	SYSMON_WDOG_LOCK(s);
	if ((smw = sysmon_armed_wdog) != NULL) {
		if ((*smw->smw_tickle)(smw) != 0) {
			printf("WARNING: KERNEL TICKLE OF WATCHDOG %s "
			    "FAILED!\n", smw->smw_name);
			/*
			 * ...we will probably reboot soon.
			 */
		}
		callout_reset(&sysmon_wdog_callout,
		    WDOG_PERIOD_TO_TICKS(smw->smw_period) / 2,
		    sysmon_wdog_ktickle, NULL);
	}
	SYSMON_WDOG_UNLOCK(s);
}

/*
 * sysmon_wdog_shutdown:
 *
 *	Perform shutdown-time operations.
 */
void
sysmon_wdog_shutdown(void *arg)
{
	struct sysmon_wdog *smw;

	/*
	 * XXX Locking here?  I don't think it's necessary.
	 */

	if ((smw = sysmon_armed_wdog) != NULL) {
		if (sysmon_wdog_setmode(smw, WDOG_MODE_DISARMED,
		    smw->smw_period))
			printf("WARNING: FAILED TO SHUTDOWN WATCHDOG %s!\n",
			    smw->smw_name);
	}
}