io/px/px_ib.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * PX Interrupt Block implementation
 */

#include <sys/types.h>
#include <sys/kmem.h>
#include <sys/async.h>
#include <sys/systm.h>		/* panicstr */
#include <sys/spl.h>
#include <sys/sunddi.h>
#include <sys/machsystm.h>	/* intr_dist_add */
#include <sys/ddi_impldefs.h>
#include <sys/cpuvar.h>
#include "px_obj.h"

/*LINTLIBRARY*/

static void px_ib_intr_redist(void *arg, int32_t weight_max, int32_t weight);
static void px_ib_intr_dist_en(dev_info_t *dip, cpuid_t cpu_id, devino_t ino,
    boolean_t wait_flag);
static uint_t px_ib_intr_reset(void *arg);

int
px_ib_attach(px_t *px_p)
{
	dev_info_t	*dip = px_p->px_dip;
	px_ib_t		*ib_p;
	sysino_t	sysino;
	px_fault_t	*fault_p = &px_p->px_fault;

	DBG(DBG_IB, dip, "px_ib_attach\n");

	if (px_lib_intr_devino_to_sysino(px_p->px_dip,
	    px_p->px_inos[PX_INTR_PEC], &sysino) != DDI_SUCCESS)
		return (DDI_FAILURE);

	/*
	 * Allocate interrupt block state structure and link it to
	 * the px state structure.
	 */
	ib_p = kmem_zalloc(sizeof (px_ib_t), KM_SLEEP);
	px_p->px_ib_p = ib_p;
	ib_p->ib_px_p = px_p;
	ib_p->ib_ino_lst = (px_ib_ino_info_t *)NULL;

	mutex_init(&ib_p->ib_intr_lock, NULL, MUTEX_DRIVER, NULL);
	mutex_init(&ib_p->ib_ino_lst_mutex, NULL, MUTEX_DRIVER, NULL);

	bus_func_register(BF_TYPE_RESINTR, px_ib_intr_reset, ib_p);

	intr_dist_add_weighted(px_ib_intr_redist, ib_p);

	/*
	 * Initialize PEC fault data structure
	 */
	fault_p->px_fh_dip = dip;
	fault_p->px_fh_sysino = sysino;
	fault_p->px_err_func = px_err_dmc_pec_intr;
	fault_p->px_intr_ino = px_p->px_inos[PX_INTR_PEC];

	return (DDI_SUCCESS);
}

void
px_ib_detach(px_t *px_p)
{
	px_ib_t		*ib_p = px_p->px_ib_p;
	dev_info_t	*dip = px_p->px_dip;

	DBG(DBG_IB, dip, "px_ib_detach\n");

	bus_func_unregister(BF_TYPE_RESINTR, px_ib_intr_reset, ib_p);
	intr_dist_rem_weighted(px_ib_intr_redist, ib_p);

	mutex_destroy(&ib_p->ib_ino_lst_mutex);
	mutex_destroy(&ib_p->ib_intr_lock);

	px_ib_free_ino_all(ib_p);

	px_p->px_ib_p = NULL;
	kmem_free(ib_p, sizeof (px_ib_t));
}

void
px_ib_intr_enable(px_t *px_p, cpuid_t cpu_id, devino_t ino)
{
	px_ib_t		*ib_p = px_p->px_ib_p;
	sysino_t	sysino;

	/*
	 * Determine the cpu for the interrupt
	 */
	mutex_enter(&ib_p->ib_intr_lock);

	DBG(DBG_IB, px_p->px_dip,
	    "px_ib_intr_enable: ino=%x cpu_id=%x\n", ino, cpu_id);

	if (px_lib_intr_devino_to_sysino(px_p->px_dip, ino,
	    &sysino) != DDI_SUCCESS) {
		DBG(DBG_IB, px_p->px_dip,
		    "px_ib_intr_enable: px_intr_devino_to_sysino() failed\n");

		mutex_exit(&ib_p->ib_intr_lock);
		return;
	}

	PX_INTR_ENABLE(px_p->px_dip, sysino, cpu_id);

	mutex_exit(&ib_p->ib_intr_lock);
}

/*ARGSUSED*/
void
px_ib_intr_disable(px_ib_t *ib_p, devino_t ino, int wait)
{
	sysino_t	sysino;

	mutex_enter(&ib_p->ib_intr_lock);

	DBG(DBG_IB, ib_p->ib_px_p->px_dip, "px_ib_intr_disable: ino=%x\n", ino);

	/* Disable the interrupt */
	if (px_lib_intr_devino_to_sysino(ib_p->ib_px_p->px_dip, ino,
	    &sysino) != DDI_SUCCESS) {
		DBG(DBG_IB, ib_p->ib_px_p->px_dip,
		    "px_ib_intr_disable: px_intr_devino_to_sysino() failed\n");

		mutex_exit(&ib_p->ib_intr_lock);
		return;
	}

	PX_INTR_DISABLE(ib_p->ib_px_p->px_dip, sysino);

	mutex_exit(&ib_p->ib_intr_lock);
}


static void
px_ib_intr_dist_en(dev_info_t *dip, cpuid_t cpu_id, devino_t ino,
    boolean_t wait_flag)
{
	uint32_t	old_cpu_id;
	sysino_t	sysino;
	intr_valid_state_t	enabled = 0;
	hrtime_t	start_time;
	intr_state_t	intr_state;
	int		e = DDI_SUCCESS;

	DBG(DBG_IB, dip, "px_ib_intr_dist_en: ino=0x%x\n", ino);

	if (px_lib_intr_devino_to_sysino(dip, ino, &sysino) != DDI_SUCCESS) {
		DBG(DBG_IB, dip, "px_ib_intr_dist_en: "
		    "px_intr_devino_to_sysino() failed, ino 0x%x\n", ino);
		return;
	}

	/* Skip enabling disabled interrupts */
	if (px_lib_intr_getvalid(dip, sysino, &enabled) != DDI_SUCCESS) {
		DBG(DBG_IB, dip, "px_ib_intr_dist_en: px_intr_getvalid() "
		    "failed, sysino 0x%x\n", sysino);
		return;
	}
	if (!enabled)
		return;

	/* Done if redistributed onto the same cpuid */
	if (px_lib_intr_gettarget(dip, sysino, &old_cpu_id) != DDI_SUCCESS) {
		DBG(DBG_IB, dip, "px_ib_intr_dist_en: "
		    "px_intr_gettarget() failed\n");
		return;
	}
	if (cpu_id == old_cpu_id)
		return;

	if (!wait_flag)
		goto done;

	/* Busy wait on pending interrupts */
	PX_INTR_DISABLE(dip, sysino);

	for (start_time = gethrtime(); !panicstr &&
	    ((e = px_lib_intr_getstate(dip, sysino, &intr_state)) ==
		DDI_SUCCESS) &&
	    (intr_state == INTR_DELIVERED_STATE); /* */) {
		if (gethrtime() - start_time > px_intrpend_timeout) {
			cmn_err(CE_WARN,
			    "%s%d: px_ib_intr_dist_en: sysino 0x%x(ino 0x%x) "
			    "from cpu id 0x%x to 0x%x timeout",
			    ddi_driver_name(dip), ddi_get_instance(dip),
			    sysino, ino, old_cpu_id, cpu_id);

			e = DDI_FAILURE;
			break;
		}
	}

	if (e != DDI_SUCCESS)
		DBG(DBG_IB, dip, "px_ib_intr_dist_en: failed, "
		    "ino 0x%x sysino 0x%x\n", ino, sysino);

done:
	PX_INTR_ENABLE(dip, sysino, cpu_id);
}


/*
 * Redistribute interrupts of the specified weight. The first call has a weight
 * of weight_max, which can be used to trigger initialization for
 * redistribution. The inos with weight [weight_max, inf.) should be processed
 * on the "weight == weight_max" call.  This first call is followed by calls
 * of decreasing weights, inos of that weight should be processed.  The final
 * call specifies a weight of zero, this can be used to trigger processing of
 * stragglers.
 */
static void
px_ib_intr_redist(void *arg, int32_t weight_max, int32_t weight)
{
	extern kmutex_t pxintr_ks_template_lock;
	px_ib_t		*ib_p = (px_ib_t *)arg;
	px_t		*px_p = ib_p->ib_px_p;
	dev_info_t	*dip = px_p->px_dip;
	px_ib_ino_info_t *ino_p;
	px_ih_t		*ih_lst;
	int32_t		dweight = 0;
	int		i;

	/* Redistribute internal interrupts */
	if (weight == 0) {
		devino_t	ino_pec = px_p->px_inos[PX_INTR_PEC];

		mutex_enter(&ib_p->ib_intr_lock);
		px_ib_intr_dist_en(dip, intr_dist_cpuid(), ino_pec, B_FALSE);
		mutex_exit(&ib_p->ib_intr_lock);
	}

	/* Redistribute device interrupts */
	mutex_enter(&ib_p->ib_ino_lst_mutex);

	for (ino_p = ib_p->ib_ino_lst; ino_p; ino_p = ino_p->ino_next) {
		uint32_t orig_cpuid;

		/*
		 * Recomputes the sum of interrupt weights of devices that
		 * share the same ino upon first call marked by
		 * (weight == weight_max).
		 */
		if (weight == weight_max) {
			ino_p->ino_intr_weight = 0;
			for (i = 0, ih_lst = ino_p->ino_ih_head;
			    i < ino_p->ino_ih_size;
			    i++, ih_lst = ih_lst->ih_next) {
				dweight = i_ddi_get_intr_weight(ih_lst->ih_dip);
				if (dweight > 0)
					ino_p->ino_intr_weight += dweight;
			}
		}

		/*
		 * As part of redistributing weighted interrupts over cpus,
		 * nexus redistributes device interrupts and updates
		 * cpu weight. The purpose is for the most light weighted
		 * cpu to take the next interrupt and gain weight, therefore
		 * attention demanding device gains more cpu attention by
		 * making itself heavy.
		 */
		if ((weight == ino_p->ino_intr_weight) ||
		    ((weight >= weight_max) &&
		    (ino_p->ino_intr_weight >= weight_max))) {
			orig_cpuid = ino_p->ino_cpuid;
			if (cpu[orig_cpuid] == NULL)
				orig_cpuid = CPU->cpu_id;

			/* select cpuid to target and mark ino established */
			ino_p->ino_cpuid = intr_dist_cpuid();

			/* Add device weight to targeted cpu. */
			for (i = 0, ih_lst = ino_p->ino_ih_head;
			    i < ino_p->ino_ih_size;
			    i++, ih_lst = ih_lst->ih_next) {
				hrtime_t ticks;

				dweight = i_ddi_get_intr_weight(ih_lst->ih_dip);
				intr_dist_cpuid_add_device_weight(
				    ino_p->ino_cpuid, ih_lst->ih_dip, dweight);

				/*
				 * different cpus may have different clock
				 * speeds. to account for this, whenever an
				 * interrupt is moved to a new CPU, we
				 * convert the accumulated ticks into nsec,
				 * based upon the clock rate of the prior
				 * CPU.
				 *
				 * It is possible that the prior CPU no longer
				 * exists. In this case, fall back to using
				 * this CPU's clock rate.
				 *
				 * Note that the value in ih_ticks has already
				 * been corrected for any power savings mode
				 * which might have been in effect.
				 *
				 * because we are updating two fields in
				 * ih_t we must lock pxintr_ks_template_lock
				 * to prevent someone from reading the kstats
				 * after we set ih_ticks to 0 and before we
				 * increment ih_nsec to compensate.
				 *
				 * we must also protect against the interrupt
				 * arriving and incrementing ih_ticks between
				 * the time we read it and when we reset it
				 * to 0. To do this we use atomic_swap.
				 */

				mutex_enter(&pxintr_ks_template_lock);
				ticks = atomic_swap_64(&ih_lst->ih_ticks, 0);
				ih_lst->ih_nsec += (uint64_t)
				    tick2ns(ticks, orig_cpuid);
				mutex_exit(&pxintr_ks_template_lock);
			}

			/* enable interrupt on new targeted cpu */
			px_ib_intr_dist_en(dip, ino_p->ino_cpuid,
			    ino_p->ino_ino, B_TRUE);
		}
	}
	mutex_exit(&ib_p->ib_ino_lst_mutex);
}

/*
 * Reset interrupts to IDLE.  This function is called during
 * panic handling after redistributing interrupts; it's needed to
 * support dumping to network devices after 'sync' from OBP.
 *
 * N.B.  This routine runs in a context where all other threads
 * are permanently suspended.
 */
static uint_t
px_ib_intr_reset(void *arg)
{
	px_ib_t		*ib_p = (px_ib_t *)arg;

	DBG(DBG_IB, ib_p->ib_px_p->px_dip, "px_ib_intr_reset\n");

	if (px_lib_intr_reset(ib_p->ib_px_p->px_dip) != DDI_SUCCESS)
		return (BF_FATAL);

	return (BF_NONE);
}

/*
 * Locate ino_info structure on ib_p->ib_ino_lst according to ino#
 * returns NULL if not found.
 */
px_ib_ino_info_t *
px_ib_locate_ino(px_ib_t *ib_p, devino_t ino_num)
{
	px_ib_ino_info_t	*ino_p = ib_p->ib_ino_lst;

	ASSERT(MUTEX_HELD(&ib_p->ib_ino_lst_mutex));

	for (; ino_p && ino_p->ino_ino != ino_num; ino_p = ino_p->ino_next);

	return (ino_p);
}

px_ib_ino_info_t *
px_ib_new_ino(px_ib_t *ib_p, devino_t ino_num, px_ih_t *ih_p)
{
	px_ib_ino_info_t	*ino_p = kmem_alloc(sizeof (px_ib_ino_info_t),
	    KM_SLEEP);
	sysino_t	sysino;

	ino_p->ino_ino = ino_num;
	ino_p->ino_ib_p = ib_p;
	ino_p->ino_unclaimed = 0;

	if (px_lib_intr_devino_to_sysino(ib_p->ib_px_p->px_dip, ino_p->ino_ino,
	    &sysino) != DDI_SUCCESS)
		return (NULL);

	ino_p->ino_sysino = sysino;

	/*
	 * Cannot disable interrupt since we might share slot
	 */
	ih_p->ih_next = ih_p;
	ino_p->ino_ih_head = ih_p;
	ino_p->ino_ih_tail = ih_p;
	ino_p->ino_ih_start = ih_p;
	ino_p->ino_ih_size = 1;

	ino_p->ino_next = ib_p->ib_ino_lst;
	ib_p->ib_ino_lst = ino_p;

	return (ino_p);
}

/*
 * The ino_p is retrieved by previous call to px_ib_locate_ino().
 */
void
px_ib_delete_ino(px_ib_t *ib_p, px_ib_ino_info_t *ino_p)
{
	px_ib_ino_info_t	*list = ib_p->ib_ino_lst;

	ASSERT(MUTEX_HELD(&ib_p->ib_ino_lst_mutex));

	if (list == ino_p)
		ib_p->ib_ino_lst = list->ino_next;
	else {
		for (; list->ino_next != ino_p; list = list->ino_next);
		list->ino_next = ino_p->ino_next;
	}
}

/*
 * Free all ino when we are detaching.
 */
void
px_ib_free_ino_all(px_ib_t *ib_p)
{
	px_ib_ino_info_t	*tmp = ib_p->ib_ino_lst;
	px_ib_ino_info_t	*next = NULL;

	while (tmp) {
		next = tmp->ino_next;
		kmem_free(tmp, sizeof (px_ib_ino_info_t));
		tmp = next;
	}
}

int
px_ib_ino_add_intr(px_t *px_p, px_ib_ino_info_t *ino_p, px_ih_t *ih_p)
{
	px_ib_t		*ib_p = ino_p->ino_ib_p;
	devino_t	ino = ino_p->ino_ino;
	sysino_t	sysino = ino_p->ino_sysino;
	dev_info_t	*dip = px_p->px_dip;
	cpuid_t		curr_cpu;
	hrtime_t	start_time;
	intr_state_t	intr_state;
	int		ret = DDI_SUCCESS;

	ASSERT(MUTEX_HELD(&ib_p->ib_ino_lst_mutex));
	ASSERT(ib_p == px_p->px_ib_p);

	DBG(DBG_IB, dip, "px_ib_ino_add_intr ino=%x\n", ino_p->ino_ino);

	/* Disable the interrupt */
	if ((ret = px_lib_intr_gettarget(dip, sysino,
	    &curr_cpu)) != DDI_SUCCESS) {
		DBG(DBG_IB, dip,
		    "px_ib_ino_add_intr px_intr_gettarget() failed\n");

		return (ret);
	}

	PX_INTR_DISABLE(dip, sysino);

	/* Busy wait on pending interrupt */
	for (start_time = gethrtime(); !panicstr &&
	    ((ret = px_lib_intr_getstate(dip, sysino, &intr_state))
	    == DDI_SUCCESS) && (intr_state == INTR_DELIVERED_STATE); /* */) {
		if (gethrtime() - start_time > px_intrpend_timeout) {
			cmn_err(CE_WARN, "%s%d: px_ib_ino_add_intr: pending "
			    "sysino 0x%x(ino 0x%x) timeout",
			    ddi_driver_name(dip), ddi_get_instance(dip),
			    sysino, ino);

			ret = DDI_FAILURE;
			break;
		}
	}

	if (ret != DDI_SUCCESS) {
		DBG(DBG_IB, dip, "px_ib_ino_add_intr: failed, "
		    "ino 0x%x sysino 0x%x\n", ino, sysino);

		return (ret);
	}

	/* Link up px_ispec_t portion of the ppd */
	ih_p->ih_next = ino_p->ino_ih_head;
	ino_p->ino_ih_tail->ih_next = ih_p;
	ino_p->ino_ih_tail = ih_p;

	ino_p->ino_ih_start = ino_p->ino_ih_head;
	ino_p->ino_ih_size++;

	/*
	 * If the interrupt was previously blocked (left in pending state)
	 * because of jabber we need to clear the pending state in case the
	 * jabber has gone away.
	 */
	if (ino_p->ino_unclaimed > px_unclaimed_intr_max) {
		cmn_err(CE_WARN,
		    "%s%d: px_ib_ino_add_intr: ino 0x%x has been unblocked",
		    ddi_driver_name(dip), ddi_get_instance(dip), ino);

		ino_p->ino_unclaimed = 0;
		if ((ret = px_lib_intr_setstate(dip, sysino,
		    INTR_IDLE_STATE)) != DDI_SUCCESS) {
			DBG(DBG_IB, px_p->px_dip,
			    "px_ib_ino_add_intr px_intr_setstate failed\n");

			return (ret);
		}
	}

	/* Re-enable interrupt */
	PX_INTR_ENABLE(dip, sysino, curr_cpu);

	return (ret);
}

/*
 * Removes px_ispec_t from the ino's link list.
 * uses hardware mutex to lock out interrupt threads.
 * Side effects: interrupt belongs to that ino is turned off on return.
 * if we are sharing PX slot with other inos, the caller needs
 * to turn it back on.
 */
int
px_ib_ino_rem_intr(px_t *px_p, px_ib_ino_info_t *ino_p, px_ih_t *ih_p)
{
	devino_t	ino = ino_p->ino_ino;
	sysino_t	sysino = ino_p->ino_sysino;
	dev_info_t	*dip = px_p->px_dip;
	px_ih_t		*ih_lst = ino_p->ino_ih_head;
	hrtime_t	start_time;
	intr_state_t	intr_state;
	int		i, ret = DDI_SUCCESS;

	ASSERT(MUTEX_HELD(&ino_p->ino_ib_p->ib_ino_lst_mutex));

	DBG(DBG_IB, px_p->px_dip, "px_ib_ino_rem_intr ino=%x\n",
	    ino_p->ino_ino);

	/* Disable the interrupt */
	PX_INTR_DISABLE(px_p->px_dip, sysino);

	if (ino_p->ino_ih_size == 1) {
		if (ih_lst != ih_p)
			goto not_found;

		/* No need to set head/tail as ino_p will be freed */
		goto reset;
	}

	/* Busy wait on pending interrupt */
	for (start_time = gethrtime(); !panicstr &&
	    ((ret = px_lib_intr_getstate(dip, sysino, &intr_state))
	    == DDI_SUCCESS) && (intr_state == INTR_DELIVERED_STATE); /* */) {
		if (gethrtime() - start_time > px_intrpend_timeout) {
			cmn_err(CE_WARN, "%s%d: px_ib_ino_rem_intr: pending "
			    "sysino 0x%x(ino 0x%x) timeout",
			    ddi_driver_name(dip), ddi_get_instance(dip),
			    sysino, ino);

			ret = DDI_FAILURE;
			break;
		}
	}

	if (ret != DDI_SUCCESS) {
		DBG(DBG_IB, dip, "px_ib_ino_rem_intr: failed, "
		    "ino 0x%x sysino 0x%x\n", ino, sysino);

		return (ret);
	}

	/*
	 * If the interrupt was previously blocked (left in pending state)
	 * because of jabber we need to clear the pending state in case the
	 * jabber has gone away.
	 */
	if (ino_p->ino_unclaimed > px_unclaimed_intr_max) {
		cmn_err(CE_WARN, "%s%d: px_ib_ino_rem_intr: "
		    "ino 0x%x has been unblocked",
		    ddi_driver_name(dip), ddi_get_instance(dip), ino);

		ino_p->ino_unclaimed = 0;
		if ((ret = px_lib_intr_setstate(dip, sysino,
		    INTR_IDLE_STATE)) != DDI_SUCCESS) {
			DBG(DBG_IB, px_p->px_dip,
			    "px_ib_ino_rem_intr px_intr_setstate failed\n");

			return (ret);
		}
	}

	/* Search the link list for ih_p */
	for (i = 0; (i < ino_p->ino_ih_size) &&
	    (ih_lst->ih_next != ih_p); i++, ih_lst = ih_lst->ih_next);

	if (ih_lst->ih_next != ih_p)
		goto not_found;

	/* Remove ih_p from the link list and maintain the head/tail */
	ih_lst->ih_next = ih_p->ih_next;

	if (ino_p->ino_ih_head == ih_p)
		ino_p->ino_ih_head = ih_p->ih_next;
	if (ino_p->ino_ih_tail == ih_p)
		ino_p->ino_ih_tail = ih_lst;

	ino_p->ino_ih_start = ino_p->ino_ih_head;

reset:
	if (ih_p->ih_config_handle)
		pci_config_teardown(&ih_p->ih_config_handle);
	if (ih_p->ih_ksp != NULL)
		kstat_delete(ih_p->ih_ksp);

	kmem_free(ih_p, sizeof (px_ih_t));
	ino_p->ino_ih_size--;

	return (ret);

not_found:
	DBG(DBG_R_INTX, ino_p->ino_ib_p->ib_px_p->px_dip,
		"ino_p=%x does not have ih_p=%x\n", ino_p, ih_p);

	return (DDI_FAILURE);
}

px_ih_t *
px_ib_ino_locate_intr(px_ib_ino_info_t *ino_p, dev_info_t *rdip,
    uint32_t inum, msiq_rec_type_t rec_type, msgcode_t msg_code)
{
	px_ih_t	*ih_lst = ino_p->ino_ih_head;
	int	i;

	for (i = 0; i < ino_p->ino_ih_size; i++, ih_lst = ih_lst->ih_next) {
		if ((ih_lst->ih_dip == rdip) && (ih_lst->ih_inum == inum) &&
		    (ih_lst->ih_rec_type == rec_type) &&
		    (ih_lst->ih_msg_code == msg_code))
			return (ih_lst);
	}

	return ((px_ih_t *)NULL);
}

px_ih_t *
px_ib_alloc_ih(dev_info_t *rdip, uint32_t inum,
    uint_t (*int_handler)(caddr_t int_handler_arg1, caddr_t int_handler_arg2),
    caddr_t int_handler_arg1, caddr_t int_handler_arg2,
    msiq_rec_type_t rec_type, msgcode_t msg_code)
{
	px_ih_t	*ih_p;

	ih_p = kmem_alloc(sizeof (px_ih_t), KM_SLEEP);
	ih_p->ih_dip = rdip;
	ih_p->ih_inum = inum;
	ih_p->ih_intr_state = PX_INTR_STATE_DISABLE;
	ih_p->ih_handler = int_handler;
	ih_p->ih_handler_arg1 = int_handler_arg1;
	ih_p->ih_handler_arg2 = int_handler_arg2;
	ih_p->ih_config_handle = NULL;
	ih_p->ih_rec_type = rec_type;
	ih_p->ih_msg_code = msg_code;
	ih_p->ih_nsec = 0;
	ih_p->ih_ticks = 0;
	ih_p->ih_ksp = NULL;

	return (ih_p);
}

/*
 * Only used for fixed or legacy interrupts.
 */
int
px_ib_update_intr_state(px_t *px_p, dev_info_t *rdip,
    uint_t inum, devino_t ino, uint_t new_intr_state)
{
	px_ib_t		*ib_p = px_p->px_ib_p;
	px_ib_ino_info_t *ino_p;
	px_ih_t		*ih_p;
	int		ret = DDI_FAILURE;

	DBG(DBG_IB, px_p->px_dip, "ib_update_intr_state: %s%d "
	    "inum %x devino %x state %x\n", ddi_driver_name(rdip),
	    ddi_get_instance(rdip), inum, ino, new_intr_state);

	mutex_enter(&ib_p->ib_ino_lst_mutex);

	if (ino_p = px_ib_locate_ino(ib_p, ino)) {
		if (ih_p = px_ib_ino_locate_intr(ino_p, rdip, inum, 0, 0)) {
			ih_p->ih_intr_state = new_intr_state;
			ret = DDI_SUCCESS;
		}
	}

	mutex_exit(&ib_p->ib_ino_lst_mutex);
	return (ret);
}