Merge illumos-gate

[unleashed/lotheac.git] / usr / src / uts / i86pc / io / mp_platform_misc.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2017 Joyent, Inc.
 */
/*
 * Copyright (c) 2010, Intel Corporation.
 * All rights reserved.
 */

/*
 * Copyright (c) 2018, Joyent, Inc.
 */

/*
 * PSMI 1.1 extensions are supported only in 2.6 and later versions.
 * PSMI 1.2 extensions are supported only in 2.7 and later versions.
 * PSMI 1.3 and 1.4 extensions are supported in Solaris 10.
 * PSMI 1.5 extensions are supported in Solaris Nevada.
 * PSMI 1.6 extensions are supported in Solaris Nevada.
 * PSMI 1.7 extensions are supported in Solaris Nevada.
 */
#define PSMI_1_7

#include <sys/processor.h>
#include <sys/time.h>
#include <sys/psm.h>
#include <sys/smp_impldefs.h>
#include <sys/inttypes.h>
#include <sys/cram.h>
#include <sys/acpi/acpi.h>
#include <sys/acpica.h>
#include <sys/psm_common.h>
#include <sys/apic.h>
#include <sys/apic_common.h>
#include <sys/pit.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/ddi_impldefs.h>
#include <sys/pci.h>
#include <sys/promif.h>
#include <sys/x86_archext.h>
#include <sys/cpc_impl.h>
#include <sys/uadmin.h>
#include <sys/panic.h>
#include <sys/debug.h>
#include <sys/archsystm.h>
#include <sys/trap.h>
#include <sys/machsystm.h>
#include <sys/cpuvar.h>
#include <sys/rm_platter.h>
#include <sys/privregs.h>
#include <sys/cyclic.h>
#include <sys/note.h>
#include <sys/pci_intr_lib.h>
#include <sys/sunndi.h>
#include <sys/hpet.h>
#include <sys/clock.h>

/*
 * Part of mp_platfrom_common.c that's used only by pcplusmp & xpv_psm
 * but not apix.
 * These functions may be moved to xpv_psm later when apix and pcplusmp
 * are merged together
 */

/*
 *      Local Function Prototypes
 */
static void apic_mark_vector(uchar_t oldvector, uchar_t newvector);
static void apic_xlate_vector_free_timeout_handler(void *arg);
static int apic_check_stuck_interrupt(apic_irq_t *irq_ptr, int old_bind_cpu,
    int new_bind_cpu, int apicindex, int intin_no, int which_irq,
    struct ioapic_reprogram_data *drep);
static int apic_setup_irq_table(dev_info_t *dip, int irqno,
    struct apic_io_intr *intrp, struct intrspec *ispec, iflag_t *intr_flagp,
    int type);
static void apic_try_deferred_reprogram(int ipl, int vect);
static void delete_defer_repro_ent(int which_irq);
static void apic_ioapic_wait_pending_clear(int ioapicindex,
    int intin_no);

extern int apic_acpi_translate_pci_irq(dev_info_t *dip, int busid, int devid,
    int ipin, int *pci_irqp, iflag_t *intr_flagp);
extern int apic_handle_pci_pci_bridge(dev_info_t *idip, int child_devno,
    int child_ipin, struct apic_io_intr **intrp);
extern uchar_t acpi_find_ioapic(int irq);
extern struct apic_io_intr *apic_find_io_intr_w_busid(int irqno, int busid);
extern int apic_find_bus_id(int bustype);
extern int apic_find_intin(uchar_t ioapic, uchar_t intin);
extern void apic_record_rdt_entry(apic_irq_t *irqptr, int irq);

extern  int apic_sci_vect;
extern  iflag_t apic_sci_flags;
/* ACPI HPET interrupt configuration; -1 if HPET not used */
extern  int apic_hpet_vect;
extern  iflag_t apic_hpet_flags;
extern  int     apic_intr_policy;
extern  char *psm_name;

/*
 * number of bits per byte, from <sys/param.h>
 */
#define UCHAR_MAX       UINT8_MAX

/* Max wait time (in repetitions) for flags to clear in an RDT entry. */
extern int apic_max_reps_clear_pending;

/* The irq # is implicit in the array index: */
struct ioapic_reprogram_data apic_reprogram_info[APIC_MAX_VECTOR+1];
/*
 * APIC_MAX_VECTOR + 1 is the maximum # of IRQs as well. ioapic_reprogram_info
 * is indexed by IRQ number, NOT by vector number.
 */

extern  int     apic_int_busy_mark;
extern  int     apic_int_free_mark;
extern  int     apic_diff_for_redistribution;
extern  int     apic_sample_factor_redistribution;
extern  int     apic_redist_cpu_skip;
extern  int     apic_num_imbalance;
extern  int     apic_num_rebind;

/* timeout for xlate_vector, mark_vector */
int     apic_revector_timeout = 16 * 10000; /* 160 millisec */

extern int      apic_defconf;
extern int      apic_irq_translate;

extern int      apic_use_acpi_madt_only;        /* 1=ONLY use MADT from ACPI */

extern  uchar_t apic_io_vectbase[MAX_IO_APIC];

extern  boolean_t ioapic_mask_workaround[MAX_IO_APIC];

/*
 * First available slot to be used as IRQ index into the apic_irq_table
 * for those interrupts (like MSI/X) that don't have a physical IRQ.
 */
extern int apic_first_avail_irq;

/*
 * apic_defer_reprogram_lock ensures that only one processor is handling
 * deferred interrupt programming at *_intr_exit time.
 */
static  lock_t  apic_defer_reprogram_lock;

/*
 * The current number of deferred reprogrammings outstanding
 */
uint_t  apic_reprogram_outstanding = 0;

#ifdef DEBUG
/*
 * Counters that keep track of deferred reprogramming stats
 */
uint_t  apic_intr_deferrals = 0;
uint_t  apic_intr_deliver_timeouts = 0;
uint_t  apic_last_ditch_reprogram_failures = 0;
uint_t  apic_deferred_setup_failures = 0;
uint_t  apic_defer_repro_total_retries = 0;
uint_t  apic_defer_repro_successes = 0;
uint_t  apic_deferred_spurious_enters = 0;
#endif

extern  int     apic_io_max;
extern  struct apic_io_intr *apic_io_intrp;

uchar_t apic_vector_to_irq[APIC_MAX_VECTOR+1];

extern  uint32_t        eisa_level_intr_mask;
        /* At least MSB will be set if EISA bus */

extern  int     apic_pci_bus_total;
extern  uchar_t apic_single_pci_busid;

/*
 * Following declarations are for revectoring; used when ISRs at different
 * IPLs share an irq.
 */
static  lock_t  apic_revector_lock;
int     apic_revector_pending = 0;
static  uchar_t *apic_oldvec_to_newvec;
static  uchar_t *apic_newvec_to_oldvec;

/* ACPI Interrupt Source Override Structure ptr */
extern ACPI_MADT_INTERRUPT_OVERRIDE *acpi_isop;
extern int acpi_iso_cnt;

/*
 * Auto-configuration routines
 */

/*
 * Initialise vector->ipl and ipl->pri arrays. level_intr and irqtable
 * are also set to NULL. vector->irq is set to a value which cannot map
 * to a real irq to show that it is free.
 */
void
apic_init_common(void)
{
        int     i, j, indx;
        int     *iptr;

        /*
         * Initialize apic_ipls from apic_vectortoipl.  This array is
         * used in apic_intr_enter to determine the IPL to use for the
         * corresponding vector.  On some systems, due to hardware errata
         * and interrupt sharing, the IPL may not correspond to the IPL listed
         * in apic_vectortoipl (see apic_addspl and apic_delspl).
         */
        for (i = 0; i < (APIC_AVAIL_VECTOR / APIC_VECTOR_PER_IPL); i++) {
                indx = i * APIC_VECTOR_PER_IPL;

                for (j = 0; j < APIC_VECTOR_PER_IPL; j++, indx++)
                        apic_ipls[indx] = apic_vectortoipl[i];
        }

        /* cpu 0 is always up (for now) */
        apic_cpus[0].aci_status = APIC_CPU_ONLINE | APIC_CPU_INTR_ENABLE;

        iptr = (int *)&apic_irq_table[0];
        for (i = 0; i <= APIC_MAX_VECTOR; i++) {
                apic_level_intr[i] = 0;
                *iptr++ = 0;
                apic_vector_to_irq[i] = APIC_RESV_IRQ;

                /* These *must* be initted to B_TRUE! */
                apic_reprogram_info[i].done = B_TRUE;
                apic_reprogram_info[i].irqp = NULL;
                apic_reprogram_info[i].tries = 0;
                apic_reprogram_info[i].bindcpu = 0;
        }

        /*
         * Allocate a dummy irq table entry for the reserved entry.
         * This takes care of the race between removing an irq and
         * clock detecting a CPU in that irq during interrupt load
         * sampling.
         */
        apic_irq_table[APIC_RESV_IRQ] =
            kmem_zalloc(sizeof (apic_irq_t), KM_SLEEP);

        mutex_init(&airq_mutex, NULL, MUTEX_DEFAULT, NULL);
}

void
ioapic_init_intr(int mask_apic)
{
        int ioapic_ix;
        struct intrspec ispec;
        apic_irq_t *irqptr;
        int i, j;
        ulong_t iflag;

        LOCK_INIT_CLEAR(&apic_revector_lock);
        LOCK_INIT_CLEAR(&apic_defer_reprogram_lock);

        /* mask interrupt vectors */
        for (j = 0; j < apic_io_max && mask_apic; j++) {
                int intin_max;

                ioapic_ix = j;
                /* Bits 23-16 define the maximum redirection entries */
                intin_max = (ioapic_read(ioapic_ix, APIC_VERS_CMD) >> 16)
                    & 0xff;
                for (i = 0; i <= intin_max; i++)
                        ioapic_write(ioapic_ix, APIC_RDT_CMD + 2 * i, AV_MASK);
        }

        /*
         * Hack alert: deal with ACPI SCI interrupt chicken/egg here
         */
        if (apic_sci_vect > 0) {
                /*
                 * acpica has already done add_avintr(); we just
                 * to finish the job by mimicing translate_irq()
                 *
                 * Fake up an intrspec and setup the tables
                 */
                ispec.intrspec_vec = apic_sci_vect;
                ispec.intrspec_pri = SCI_IPL;

                if (apic_setup_irq_table(NULL, apic_sci_vect, NULL,
                    &ispec, &apic_sci_flags, DDI_INTR_TYPE_FIXED) < 0) {
                        cmn_err(CE_WARN, "!apic: SCI setup failed");
                        return;
                }
                irqptr = apic_irq_table[apic_sci_vect];

                iflag = intr_clear();
                lock_set(&apic_ioapic_lock);

                /* Program I/O APIC */
                (void) apic_setup_io_intr(irqptr, apic_sci_vect, B_FALSE);

                lock_clear(&apic_ioapic_lock);
                intr_restore(iflag);

                irqptr->airq_share++;
        }

        /*
         * Hack alert: deal with ACPI HPET interrupt chicken/egg here.
         */
        if (apic_hpet_vect > 0) {
                /*
                 * hpet has already done add_avintr(); we just need
                 * to finish the job by mimicing translate_irq()
                 *
                 * Fake up an intrspec and setup the tables
                 */
                ispec.intrspec_vec = apic_hpet_vect;
                ispec.intrspec_pri = CBE_HIGH_PIL;

                if (apic_setup_irq_table(NULL, apic_hpet_vect, NULL,
                    &ispec, &apic_hpet_flags, DDI_INTR_TYPE_FIXED) < 0) {
                        cmn_err(CE_WARN, "!apic: HPET setup failed");
                        return;
                }
                irqptr = apic_irq_table[apic_hpet_vect];

                iflag = intr_clear();
                lock_set(&apic_ioapic_lock);

                /* Program I/O APIC */
                (void) apic_setup_io_intr(irqptr, apic_hpet_vect, B_FALSE);

                lock_clear(&apic_ioapic_lock);
                intr_restore(iflag);

                irqptr->airq_share++;
        }
}

/*
 * Add mask bits to disable interrupt vector from happening
 * at or above IPL. In addition, it should remove mask bits
 * to enable interrupt vectors below the given IPL.
 *
 * Both add and delspl are complicated by the fact that different interrupts
 * may share IRQs. This can happen in two ways.
 * 1. The same H/W line is shared by more than 1 device
 * 1a. with interrupts at different IPLs
 * 1b. with interrupts at same IPL
 * 2. We ran out of vectors at a given IPL and started sharing vectors.
 * 1b and 2 should be handled gracefully, except for the fact some ISRs
 * will get called often when no interrupt is pending for the device.
 * For 1a, we handle it at the higher IPL.
 */
/*ARGSUSED*/
int
apic_addspl_common(int irqno, int ipl, int min_ipl, int max_ipl)
{
        uchar_t vector;
        ulong_t iflag;
        apic_irq_t *irqptr, *irqheadptr;
        int irqindex;

        ASSERT(max_ipl <= UCHAR_MAX);
        irqindex = IRQINDEX(irqno);

        if ((irqindex == -1) || (!apic_irq_table[irqindex]))
                return (PSM_FAILURE);

        mutex_enter(&airq_mutex);
        irqptr = irqheadptr = apic_irq_table[irqindex];

        DDI_INTR_IMPLDBG((CE_CONT, "apic_addspl: dip=0x%p type=%d irqno=0x%x "
            "vector=0x%x\n", (void *)irqptr->airq_dip,
            irqptr->airq_mps_intr_index, irqno, irqptr->airq_vector));

        while (irqptr) {
                if (VIRTIRQ(irqindex, irqptr->airq_share_id) == irqno)
                        break;
                irqptr = irqptr->airq_next;
        }
        irqptr->airq_share++;

        mutex_exit(&airq_mutex);

        /* return if it is not hardware interrupt */
        if (irqptr->airq_mps_intr_index == RESERVE_INDEX)
                return (PSM_SUCCESS);

        /* Or if there are more interupts at a higher IPL */
        if (ipl != max_ipl)
                return (PSM_SUCCESS);

        /*
         * if apic_picinit() has not been called yet, just return.
         * At the end of apic_picinit(), we will call setup_io_intr().
         */

        if (!apic_picinit_called)
                return (PSM_SUCCESS);

        /*
         * Upgrade vector if max_ipl is not earlier ipl. If we cannot allocate,
         * return failure.
         */
        if (irqptr->airq_ipl != max_ipl &&
            !ioapic_mask_workaround[irqptr->airq_ioapicindex]) {

                vector = apic_allocate_vector(max_ipl, irqindex, 1);
                if (vector == 0) {
                        irqptr->airq_share--;
                        return (PSM_FAILURE);
                }
                irqptr = irqheadptr;
                apic_mark_vector(irqptr->airq_vector, vector);
                while (irqptr) {
                        irqptr->airq_vector = vector;
                        irqptr->airq_ipl = (uchar_t)max_ipl;
                        /*
                         * reprogram irq being added and every one else
                         * who is not in the UNINIT state
                         */
                        if ((VIRTIRQ(irqindex, irqptr->airq_share_id) ==
                            irqno) || (irqptr->airq_temp_cpu != IRQ_UNINIT)) {
                                apic_record_rdt_entry(irqptr, irqindex);

                                iflag = intr_clear();
                                lock_set(&apic_ioapic_lock);

                                (void) apic_setup_io_intr(irqptr, irqindex,
                                    B_FALSE);

                                lock_clear(&apic_ioapic_lock);
                                intr_restore(iflag);
                        }
                        irqptr = irqptr->airq_next;
                }
                return (PSM_SUCCESS);

        } else if (irqptr->airq_ipl != max_ipl &&
            ioapic_mask_workaround[irqptr->airq_ioapicindex]) {
                /*
                 * We cannot upgrade the vector, but we can change
                 * the IPL that this vector induces.
                 *
                 * Note that we subtract APIC_BASE_VECT from the vector
                 * here because this array is used in apic_intr_enter
                 * (no need to add APIC_BASE_VECT in that hot code
                 * path since we can do it in the rarely-executed path
                 * here).
                 */
                apic_ipls[irqptr->airq_vector - APIC_BASE_VECT] =
                    (uchar_t)max_ipl;

                irqptr = irqheadptr;
                while (irqptr) {
                        irqptr->airq_ipl = (uchar_t)max_ipl;
                        irqptr = irqptr->airq_next;
                }

                return (PSM_SUCCESS);
        }

        ASSERT(irqptr);

        iflag = intr_clear();
        lock_set(&apic_ioapic_lock);

        (void) apic_setup_io_intr(irqptr, irqindex, B_FALSE);

        lock_clear(&apic_ioapic_lock);
        intr_restore(iflag);

        return (PSM_SUCCESS);
}

/*
 * Recompute mask bits for the given interrupt vector.
 * If there is no interrupt servicing routine for this
 * vector, this function should disable interrupt vector
 * from happening at all IPLs. If there are still
 * handlers using the given vector, this function should
 * disable the given vector from happening below the lowest
 * IPL of the remaining hadlers.
 */
/*ARGSUSED*/
int
apic_delspl_common(int irqno, int ipl, int min_ipl, int max_ipl)
{
        uchar_t vector;
        uint32_t bind_cpu;
        int intin, irqindex;
        int ioapic_ix;
        apic_irq_t      *irqptr, *preirqptr, *irqheadptr, *irqp;
        ulong_t iflag;

        mutex_enter(&airq_mutex);
        irqindex = IRQINDEX(irqno);
        irqptr = preirqptr = irqheadptr = apic_irq_table[irqindex];

        DDI_INTR_IMPLDBG((CE_CONT, "apic_delspl: dip=0x%p type=%d irqno=0x%x "
            "vector=0x%x\n", (void *)irqptr->airq_dip,
            irqptr->airq_mps_intr_index, irqno, irqptr->airq_vector));

        while (irqptr) {
                if (VIRTIRQ(irqindex, irqptr->airq_share_id) == irqno)
                        break;
                preirqptr = irqptr;
                irqptr = irqptr->airq_next;
        }
        ASSERT(irqptr);

        irqptr->airq_share--;

        mutex_exit(&airq_mutex);

        /*
         * If there are more interrupts at a higher IPL, we don't need
         * to disable anything.
         */
        if (ipl < max_ipl)
                return (PSM_SUCCESS);

        /* return if it is not hardware interrupt */
        if (irqptr->airq_mps_intr_index == RESERVE_INDEX)
                return (PSM_SUCCESS);

        if (!apic_picinit_called) {
                /*
                 * Clear irq_struct. If two devices shared an intpt
                 * line & 1 unloaded before picinit, we are hosed. But, then
                 * we hope the machine survive.
                 */
                irqptr->airq_mps_intr_index = FREE_INDEX;
                irqptr->airq_temp_cpu = IRQ_UNINIT;
                apic_free_vector(irqptr->airq_vector);
                return (PSM_SUCCESS);
        }
        /*
         * Downgrade vector to new max_ipl if needed. If we cannot allocate,
         * use old IPL. Not very elegant, but it should work.
         */
        if ((irqptr->airq_ipl != max_ipl) && (max_ipl != PSM_INVALID_IPL) &&
            !ioapic_mask_workaround[irqptr->airq_ioapicindex]) {
                apic_irq_t      *irqp;
                if ((vector = apic_allocate_vector(max_ipl, irqno, 1))) {
                        apic_mark_vector(irqheadptr->airq_vector, vector);
                        irqp = irqheadptr;
                        while (irqp) {
                                irqp->airq_vector = vector;
                                irqp->airq_ipl = (uchar_t)max_ipl;
                                if (irqp->airq_temp_cpu != IRQ_UNINIT) {
                                        apic_record_rdt_entry(irqp, irqindex);

                                        iflag = intr_clear();
                                        lock_set(&apic_ioapic_lock);

                                        (void) apic_setup_io_intr(irqp,
                                            irqindex, B_FALSE);

                                        lock_clear(&apic_ioapic_lock);
                                        intr_restore(iflag);
                                }
                                irqp = irqp->airq_next;
                        }
                }

        } else if (irqptr->airq_ipl != max_ipl &&
            max_ipl != PSM_INVALID_IPL &&
            ioapic_mask_workaround[irqptr->airq_ioapicindex]) {

        /*
         * We cannot downgrade the IPL of the vector below the vector's
         * hardware priority. If we did, it would be possible for a
         * higher-priority hardware vector to interrupt a CPU running at an IPL
         * lower than the hardware priority of the interrupting vector (but
         * higher than the soft IPL of this IRQ). When this happens, we would
         * then try to drop the IPL BELOW what it was (effectively dropping
         * below base_spl) which would be potentially catastrophic.
         *
         * (e.g. Suppose the hardware vector associated with this IRQ is 0x40
         * (hardware IPL of 4).  Further assume that the old IPL of this IRQ
         * was 4, but the new IPL is 1.  If we forced vector 0x40 to result in
         * an IPL of 1, it would be possible for the processor to be executing
         * at IPL 3 and for an interrupt to come in on vector 0x40, interrupting
         * the currently-executing ISR.  When apic_intr_enter consults
         * apic_irqs[], it will return 1, bringing the IPL of the CPU down to 1
         * so even though the processor was running at IPL 4, an IPL 1
         * interrupt will have interrupted it, which must not happen)).
         *
         * Effectively, this means that the hardware priority corresponding to
         * the IRQ's IPL (in apic_ipls[]) cannot be lower than the vector's
         * hardware priority.
         *
         * (In the above example, then, after removal of the IPL 4 device's
         * interrupt handler, the new IPL will continue to be 4 because the
         * hardware priority that IPL 1 implies is lower than the hardware
         * priority of the vector used.)
         */
                /* apic_ipls is indexed by vector, starting at APIC_BASE_VECT */
                const int apic_ipls_index = irqptr->airq_vector -
                    APIC_BASE_VECT;
                const int vect_inherent_hwpri = irqptr->airq_vector >>
                    APIC_IPL_SHIFT;

                /*
                 * If there are still devices using this IRQ, determine the
                 * new ipl to use.
                 */
                if (irqptr->airq_share) {
                        int vect_desired_hwpri, hwpri;

                        ASSERT(max_ipl < MAXIPL);
                        vect_desired_hwpri = apic_ipltopri[max_ipl] >>
                            APIC_IPL_SHIFT;

                        /*
                         * If the desired IPL's hardware priority is lower
                         * than that of the vector, use the hardware priority
                         * of the vector to determine the new IPL.
                         */
                        hwpri = (vect_desired_hwpri < vect_inherent_hwpri) ?
                            vect_inherent_hwpri : vect_desired_hwpri;

                        /*
                         * Now, to get the right index for apic_vectortoipl,
                         * we need to subtract APIC_BASE_VECT from the
                         * hardware-vector-equivalent (in hwpri).  Since hwpri
                         * is already shifted, we shift APIC_BASE_VECT before
                         * doing the subtraction.
                         */
                        hwpri -= (APIC_BASE_VECT >> APIC_IPL_SHIFT);

                        ASSERT(hwpri >= 0);
                        ASSERT(hwpri < MAXIPL);
                        max_ipl = apic_vectortoipl[hwpri];
                        apic_ipls[apic_ipls_index] = (uchar_t)max_ipl;

                        irqp = irqheadptr;
                        while (irqp) {
                                irqp->airq_ipl = (uchar_t)max_ipl;
                                irqp = irqp->airq_next;
                        }
                } else {
                        /*
                         * No more devices on this IRQ, so reset this vector's
                         * element in apic_ipls to the original IPL for this
                         * vector
                         */
                        apic_ipls[apic_ipls_index] =
                            apic_vectortoipl[vect_inherent_hwpri];
                }
        }

        /*
         * If there are still active interrupts, we are done.
         */
        if (irqptr->airq_share)
                return (PSM_SUCCESS);

        iflag = intr_clear();
        lock_set(&apic_ioapic_lock);

        if (irqptr->airq_mps_intr_index == MSI_INDEX) {
                /*
                 * Disable the MSI vector
                 * Make sure we only disable on the last
                 * of the multi-MSI support
                 */
                if (i_ddi_intr_get_current_nenables(irqptr->airq_dip) == 1) {
                        apic_pci_msi_disable_mode(irqptr->airq_dip,
                            DDI_INTR_TYPE_MSI);
                }
        } else if (irqptr->airq_mps_intr_index == MSIX_INDEX) {
                /*
                 * Disable the MSI-X vector
                 * needs to clear its mask and addr/data for each MSI-X
                 */
                apic_pci_msi_unconfigure(irqptr->airq_dip, DDI_INTR_TYPE_MSIX,
                    irqptr->airq_origirq);
                /*
                 * Make sure we only disable on the last MSI-X
                 */
                if (i_ddi_intr_get_current_nenables(irqptr->airq_dip) == 1) {
                        apic_pci_msi_disable_mode(irqptr->airq_dip,
                            DDI_INTR_TYPE_MSIX);
                }
        } else {
                /*
                 * The assumption here is that this is safe, even for
                 * systems with IOAPICs that suffer from the hardware
                 * erratum because all devices have been quiesced before
                 * they unregister their interrupt handlers.  If that
                 * assumption turns out to be false, this mask operation
                 * can induce the same erratum result we're trying to
                 * avoid.
                 */
                ioapic_ix = irqptr->airq_ioapicindex;
                intin = irqptr->airq_intin_no;
                ioapic_write(ioapic_ix, APIC_RDT_CMD + 2 * intin, AV_MASK);
        }

        apic_vt_ops->apic_intrmap_free_entry(&irqptr->airq_intrmap_private);

        /*
         * This irq entry is the only one in the chain.
         */
        if (irqheadptr->airq_next == NULL) {
                ASSERT(irqheadptr == irqptr);
                bind_cpu = irqptr->airq_temp_cpu;
                if (((uint32_t)bind_cpu != IRQ_UNBOUND) &&
                    ((uint32_t)bind_cpu != IRQ_UNINIT)) {
                        ASSERT(apic_cpu_in_range(bind_cpu));
                        if (bind_cpu & IRQ_USER_BOUND) {
                                /* If hardbound, temp_cpu == cpu */
                                bind_cpu &= ~IRQ_USER_BOUND;
                                apic_cpus[bind_cpu].aci_bound--;
                        } else
                                apic_cpus[bind_cpu].aci_temp_bound--;
                }
                irqptr->airq_temp_cpu = IRQ_UNINIT;
                irqptr->airq_mps_intr_index = FREE_INDEX;
                lock_clear(&apic_ioapic_lock);
                intr_restore(iflag);
                apic_free_vector(irqptr->airq_vector);
                return (PSM_SUCCESS);
        }

        /*
         * If we get here, we are sharing the vector and there are more than
         * one active irq entries in the chain.
         */
        lock_clear(&apic_ioapic_lock);
        intr_restore(iflag);

        mutex_enter(&airq_mutex);
        /* Remove the irq entry from the chain */
        if (irqptr == irqheadptr) { /* The irq entry is at the head */
                apic_irq_table[irqindex] = irqptr->airq_next;
        } else {
                preirqptr->airq_next = irqptr->airq_next;
        }
        /* Free the irq entry */
        kmem_free(irqptr, sizeof (apic_irq_t));
        mutex_exit(&airq_mutex);

        return (PSM_SUCCESS);
}

/*
 * apic_introp_xlate() replaces apic_translate_irq() and is
 * called only from apic_intr_ops().  With the new ADII framework,
 * the priority can no longer be retrieved through i_ddi_get_intrspec().
 * It has to be passed in from the caller.
 *
 * Return value:
 *      Success: irqno for the given device
 *      Failure: -1
 */
int
apic_introp_xlate(dev_info_t *dip, struct intrspec *ispec, int type)
{
        char dev_type[16];
        int dev_len, pci_irq, newirq, bustype, devid, busid, i;
        int irqno = ispec->intrspec_vec;
        ddi_acc_handle_t cfg_handle;
        uchar_t ipin;
        struct apic_io_intr *intrp;
        iflag_t intr_flag;
        ACPI_SUBTABLE_HEADER    *hp;
        ACPI_MADT_INTERRUPT_OVERRIDE *isop;
        apic_irq_t *airqp;
        int parent_is_pci_or_pciex = 0;
        int child_is_pciex = 0;

        DDI_INTR_IMPLDBG((CE_CONT, "apic_introp_xlate: dip=0x%p name=%s "
            "type=%d irqno=0x%x\n", (void *)dip, ddi_get_name(dip), type,
            irqno));

        dev_len = sizeof (dev_type);
        if (ddi_getlongprop_buf(DDI_DEV_T_ANY, ddi_get_parent(dip),
            DDI_PROP_DONTPASS, "device_type", (caddr_t)dev_type,
            &dev_len) == DDI_PROP_SUCCESS) {
                if ((strcmp(dev_type, "pci") == 0) ||
                    (strcmp(dev_type, "pciex") == 0))
                        parent_is_pci_or_pciex = 1;
        }

        if (ddi_getlongprop_buf(DDI_DEV_T_ANY, dip,
            DDI_PROP_DONTPASS, "compatible", (caddr_t)dev_type,
            &dev_len) == DDI_PROP_SUCCESS) {
                if (strstr(dev_type, "pciex"))
                        child_is_pciex = 1;
        }

        if (DDI_INTR_IS_MSI_OR_MSIX(type)) {
                if ((airqp = apic_find_irq(dip, ispec, type)) != NULL) {
                        airqp->airq_iflag.bustype =
                            child_is_pciex ? BUS_PCIE : BUS_PCI;
                        return (apic_vector_to_irq[airqp->airq_vector]);
                }
                return (apic_setup_irq_table(dip, irqno, NULL, ispec,
                    NULL, type));
        }

        bustype = 0;

        /* check if we have already translated this irq */
        mutex_enter(&airq_mutex);
        newirq = apic_min_device_irq;
        for (; newirq <= apic_max_device_irq; newirq++) {
                airqp = apic_irq_table[newirq];
                while (airqp) {
                        if ((airqp->airq_dip == dip) &&
                            (airqp->airq_origirq == irqno) &&
                            (airqp->airq_mps_intr_index != FREE_INDEX)) {

                                mutex_exit(&airq_mutex);
                                return (VIRTIRQ(newirq, airqp->airq_share_id));
                        }
                        airqp = airqp->airq_next;
                }
        }
        mutex_exit(&airq_mutex);

        if (apic_defconf)
                goto defconf;

        if ((dip == NULL) || (!apic_irq_translate && !apic_enable_acpi))
                goto nonpci;

        if (parent_is_pci_or_pciex) {
                /* pci device */
                if (acpica_get_bdf(dip, &busid, &devid, NULL) != 0)
                        goto nonpci;
                if (busid == 0 && apic_pci_bus_total == 1)
                        busid = (int)apic_single_pci_busid;

                if (pci_config_setup(dip, &cfg_handle) != DDI_SUCCESS)
                        return (-1);
                ipin = pci_config_get8(cfg_handle, PCI_CONF_IPIN) - PCI_INTA;
                pci_config_teardown(&cfg_handle);
                if (apic_enable_acpi && !apic_use_acpi_madt_only) {
                        if (apic_acpi_translate_pci_irq(dip, busid, devid,
                            ipin, &pci_irq, &intr_flag) != ACPI_PSM_SUCCESS)
                                return (-1);

                        intr_flag.bustype = child_is_pciex ? BUS_PCIE : BUS_PCI;
                        return (apic_setup_irq_table(dip, pci_irq, NULL, ispec,
                            &intr_flag, type));
                } else {
                        pci_irq = ((devid & 0x1f) << 2) | (ipin & 0x3);
                        if ((intrp = apic_find_io_intr_w_busid(pci_irq, busid))
                            == NULL) {
                                if ((pci_irq = apic_handle_pci_pci_bridge(dip,
                                    devid, ipin, &intrp)) == -1)
                                        return (-1);
                        }
                        return (apic_setup_irq_table(dip, pci_irq, intrp, ispec,
                            NULL, type));
                }
        } else if (strcmp(dev_type, "isa") == 0)
                bustype = BUS_ISA;
        else if (strcmp(dev_type, "eisa") == 0)
                bustype = BUS_EISA;

nonpci:
        if (apic_enable_acpi && !apic_use_acpi_madt_only) {
                /* search iso entries first */
                if (acpi_iso_cnt != 0) {
                        hp = (ACPI_SUBTABLE_HEADER *)acpi_isop;
                        i = 0;
                        while (i < acpi_iso_cnt) {
                                if (hp->Type ==
                                    ACPI_MADT_TYPE_INTERRUPT_OVERRIDE) {
                                        isop =
                                            (ACPI_MADT_INTERRUPT_OVERRIDE *) hp;
                                        if (isop->Bus == 0 &&
                                            isop->SourceIrq == irqno) {
                                                newirq = isop->GlobalIrq;
                                                intr_flag.intr_po =
                                                    isop->IntiFlags &
                                                    ACPI_MADT_POLARITY_MASK;
                                                intr_flag.intr_el =
                                                    (isop->IntiFlags &
                                                    ACPI_MADT_TRIGGER_MASK)
                                                    >> 2;
                                                intr_flag.bustype = BUS_ISA;

                                                return (apic_setup_irq_table(
                                                    dip, newirq, NULL, ispec,
                                                    &intr_flag, type));

                                        }
                                        i++;
                                }
                                hp = (ACPI_SUBTABLE_HEADER *)(((char *)hp) +
                                    hp->Length);
                        }
                }
                intr_flag.intr_po = INTR_PO_ACTIVE_HIGH;
                intr_flag.intr_el = INTR_EL_EDGE;
                intr_flag.bustype = BUS_ISA;
                return (apic_setup_irq_table(dip, irqno, NULL, ispec,
                    &intr_flag, type));
        } else {
                if (bustype == 0)       /* not initialized */
                        bustype = eisa_level_intr_mask ? BUS_EISA : BUS_ISA;
                for (i = 0; i < 2; i++) {
                        if (((busid = apic_find_bus_id(bustype)) != -1) &&
                            ((intrp = apic_find_io_intr_w_busid(irqno, busid))
                            != NULL)) {
                                if ((newirq = apic_setup_irq_table(dip, irqno,
                                    intrp, ispec, NULL, type)) != -1) {
                                        return (newirq);
                                }
                                goto defconf;
                        }
                        bustype = (bustype == BUS_EISA) ? BUS_ISA : BUS_EISA;
                }
        }

/* MPS default configuration */
defconf:
        newirq = apic_setup_irq_table(dip, irqno, NULL, ispec, NULL, type);
        if (newirq == -1)
                return (-1);
        ASSERT(IRQINDEX(newirq) == irqno);
        ASSERT(apic_irq_table[irqno]);
        return (newirq);
}

/*
 * Attempt to share vector with someone else
 */
static int
apic_share_vector(int irqno, iflag_t *intr_flagp, short intr_index, int ipl,
    uchar_t ioapicindex, uchar_t ipin, apic_irq_t **irqptrp)
{
#ifdef DEBUG
        apic_irq_t *tmpirqp = NULL;
#endif /* DEBUG */
        apic_irq_t *irqptr, dummyirq;
        int     newirq, chosen_irq = -1, share = 127;
        int     lowest, highest, i;
        uchar_t share_id;

        DDI_INTR_IMPLDBG((CE_CONT, "apic_share_vector: irqno=0x%x "
            "intr_index=0x%x ipl=0x%x\n", irqno, intr_index, ipl));

        highest = apic_ipltopri[ipl] + APIC_VECTOR_MASK;
        lowest = apic_ipltopri[ipl-1] + APIC_VECTOR_PER_IPL;

        if (highest < lowest) /* Both ipl and ipl-1 map to same pri */
                lowest -= APIC_VECTOR_PER_IPL;
        dummyirq.airq_mps_intr_index = intr_index;
        dummyirq.airq_ioapicindex = ioapicindex;
        dummyirq.airq_intin_no = ipin;
        if (intr_flagp)
                dummyirq.airq_iflag = *intr_flagp;
        apic_record_rdt_entry(&dummyirq, irqno);
        for (i = lowest; i <= highest; i++) {
                newirq = apic_vector_to_irq[i];
                if (newirq == APIC_RESV_IRQ)
                        continue;
                irqptr = apic_irq_table[newirq];

                if ((dummyirq.airq_rdt_entry & 0xFF00) !=
                    (irqptr->airq_rdt_entry & 0xFF00))
                        /* not compatible */
                        continue;

                if (irqptr->airq_share < share) {
                        share = irqptr->airq_share;
                        chosen_irq = newirq;
                }
        }
        if (chosen_irq != -1) {
                /*
                 * Assign a share id which is free or which is larger
                 * than the largest one.
                 */
                share_id = 1;
                mutex_enter(&airq_mutex);
                irqptr = apic_irq_table[chosen_irq];
                while (irqptr) {
                        if (irqptr->airq_mps_intr_index == FREE_INDEX) {
                                share_id = irqptr->airq_share_id;
                                break;
                        }
                        if (share_id <= irqptr->airq_share_id)
                                share_id = irqptr->airq_share_id + 1;
#ifdef DEBUG
                        tmpirqp = irqptr;
#endif /* DEBUG */
                        irqptr = irqptr->airq_next;
                }
                if (!irqptr) {
                        irqptr = kmem_zalloc(sizeof (apic_irq_t), KM_SLEEP);
                        irqptr->airq_temp_cpu = IRQ_UNINIT;
                        irqptr->airq_next =
                            apic_irq_table[chosen_irq]->airq_next;
                        apic_irq_table[chosen_irq]->airq_next = irqptr;
#ifdef  DEBUG
                        tmpirqp = apic_irq_table[chosen_irq];
#endif /* DEBUG */
                }
                irqptr->airq_mps_intr_index = intr_index;
                irqptr->airq_ioapicindex = ioapicindex;
                irqptr->airq_intin_no = ipin;
                if (intr_flagp)
                        irqptr->airq_iflag = *intr_flagp;
                irqptr->airq_vector = apic_irq_table[chosen_irq]->airq_vector;
                irqptr->airq_share_id = share_id;
                apic_record_rdt_entry(irqptr, irqno);
                *irqptrp = irqptr;
#ifdef  DEBUG
                /* shuffle the pointers to test apic_delspl path */
                if (tmpirqp) {
                        tmpirqp->airq_next = irqptr->airq_next;
                        irqptr->airq_next = apic_irq_table[chosen_irq];
                        apic_irq_table[chosen_irq] = irqptr;
                }
#endif /* DEBUG */
                mutex_exit(&airq_mutex);
                return (VIRTIRQ(chosen_irq, share_id));
        }
        return (-1);
}

/*
 * Allocate/Initialize the apic_irq_table[] entry for given irqno. If the entry
 * is used already, we will try to allocate a new irqno.
 *
 * Return value:
 *      Success: irqno
 *      Failure: -1
 */
static int
apic_setup_irq_table(dev_info_t *dip, int irqno, struct apic_io_intr *intrp,
    struct intrspec *ispec, iflag_t *intr_flagp, int type)
{
        int origirq;
        uchar_t ipl;
        int     newirq, intr_index;
        uchar_t ipin, ioapic, ioapicindex, vector;
        apic_irq_t *irqptr;
        major_t major;
        dev_info_t      *sdip;

        ASSERT(ispec != NULL);

        origirq = ispec->intrspec_vec;
        ipl = ispec->intrspec_pri;

        DDI_INTR_IMPLDBG((CE_CONT, "apic_setup_irq_table: dip=0x%p type=%d "
            "irqno=0x%x origirq=0x%x\n", (void *)dip, type, irqno, origirq));

        major =  (dip != NULL) ? ddi_driver_major(dip) : 0;

        if (DDI_INTR_IS_MSI_OR_MSIX(type)) {
                /* MSI/X doesn't need to setup ioapic stuffs */
                ioapicindex = 0xff;
                ioapic = 0xff;
                ipin = (uchar_t)0xff;
                intr_index = (type == DDI_INTR_TYPE_MSI) ? MSI_INDEX :
                    MSIX_INDEX;
                mutex_enter(&airq_mutex);
                if ((irqno = apic_allocate_irq(apic_first_avail_irq)) == -1) {
                        mutex_exit(&airq_mutex);
                        /* need an irq for MSI/X to index into autovect[] */
                        cmn_err(CE_WARN, "No interrupt irq: %s instance %d",
                            ddi_get_name(dip), ddi_get_instance(dip));
                        return (-1);
                }
                mutex_exit(&airq_mutex);

        } else if (intrp != NULL) {
                intr_index = (int)(intrp - apic_io_intrp);
                ioapic = intrp->intr_destid;
                ipin = intrp->intr_destintin;
                /* Find ioapicindex. If destid was ALL, we will exit with 0. */
                for (ioapicindex = apic_io_max - 1; ioapicindex; ioapicindex--)
                        if (apic_io_id[ioapicindex] == ioapic)
                                break;
                ASSERT((ioapic == apic_io_id[ioapicindex]) ||
                    (ioapic == INTR_ALL_APIC));

                /* check whether this intin# has been used by another irqno */
                if ((newirq = apic_find_intin(ioapicindex, ipin)) != -1) {
                        return (newirq);
                }

        } else if (intr_flagp != NULL) {
                /* ACPI case */
                intr_index = ACPI_INDEX;
                ioapicindex = acpi_find_ioapic(irqno);
                ASSERT(ioapicindex != 0xFF);
                ioapic = apic_io_id[ioapicindex];
                ipin = irqno - apic_io_vectbase[ioapicindex];
                if (apic_irq_table[irqno] &&
                    apic_irq_table[irqno]->airq_mps_intr_index == ACPI_INDEX) {
                        ASSERT(apic_irq_table[irqno]->airq_intin_no == ipin &&
                            apic_irq_table[irqno]->airq_ioapicindex ==
                            ioapicindex);
                        return (irqno);
                }

        } else {
                /* default configuration */
                ioapicindex = 0;
                ioapic = apic_io_id[ioapicindex];
                ipin = (uchar_t)irqno;
                intr_index = DEFAULT_INDEX;
        }

        if ((vector = apic_allocate_vector(ipl, irqno, 0)) == 0) {
                if ((newirq = apic_share_vector(irqno, intr_flagp, intr_index,
                    ipl, ioapicindex, ipin, &irqptr)) != -1) {
                        irqptr->airq_ipl = ipl;
                        irqptr->airq_origirq = (uchar_t)origirq;
                        irqptr->airq_dip = dip;
                        irqptr->airq_major = major;
                        sdip = apic_irq_table[IRQINDEX(newirq)]->airq_dip;
                        /* This is OK to do really */
                        if (sdip == NULL) {
                                cmn_err(CE_WARN, "Sharing vectors: %s"
                                    " instance %d and SCI",
                                    ddi_get_name(dip), ddi_get_instance(dip));
                        } else {
                                cmn_err(CE_WARN, "Sharing vectors: %s"
                                    " instance %d and %s instance %d",
                                    ddi_get_name(sdip), ddi_get_instance(sdip),
                                    ddi_get_name(dip), ddi_get_instance(dip));
                        }
                        return (newirq);
                }
                /* try high priority allocation now  that share has failed */
                if ((vector = apic_allocate_vector(ipl, irqno, 1)) == 0) {
                        cmn_err(CE_WARN, "No interrupt vector: %s instance %d",
                            ddi_get_name(dip), ddi_get_instance(dip));
                        return (-1);
                }
        }

        mutex_enter(&airq_mutex);
        if (apic_irq_table[irqno] == NULL) {
                irqptr = kmem_zalloc(sizeof (apic_irq_t), KM_SLEEP);
                irqptr->airq_temp_cpu = IRQ_UNINIT;
                apic_irq_table[irqno] = irqptr;
        } else {
                irqptr = apic_irq_table[irqno];
                if (irqptr->airq_mps_intr_index != FREE_INDEX) {
                        /*
                         * The slot is used by another irqno, so allocate
                         * a free irqno for this interrupt
                         */
                        newirq = apic_allocate_irq(apic_first_avail_irq);
                        if (newirq == -1) {
                                mutex_exit(&airq_mutex);
                                return (-1);
                        }
                        irqno = newirq;
                        irqptr = apic_irq_table[irqno];
                        if (irqptr == NULL) {
                                irqptr = kmem_zalloc(sizeof (apic_irq_t),
                                    KM_SLEEP);
                                irqptr->airq_temp_cpu = IRQ_UNINIT;
                                apic_irq_table[irqno] = irqptr;
                        }
                        vector = apic_modify_vector(vector, newirq);
                }
        }
        apic_max_device_irq = max(irqno, apic_max_device_irq);
        apic_min_device_irq = min(irqno, apic_min_device_irq);
        mutex_exit(&airq_mutex);
        irqptr->airq_ioapicindex = ioapicindex;
        irqptr->airq_intin_no = ipin;
        irqptr->airq_ipl = ipl;
        irqptr->airq_vector = vector;
        irqptr->airq_origirq = (uchar_t)origirq;
        irqptr->airq_share_id = 0;
        irqptr->airq_mps_intr_index = (short)intr_index;
        irqptr->airq_dip = dip;
        irqptr->airq_major = major;
        irqptr->airq_cpu = apic_bind_intr(dip, irqno, ioapic, ipin);
        if (intr_flagp)
                irqptr->airq_iflag = *intr_flagp;

        if (!DDI_INTR_IS_MSI_OR_MSIX(type)) {
                /* setup I/O APIC entry for non-MSI/X interrupts */
                apic_record_rdt_entry(irqptr, irqno);
        }
        return (irqno);
}

/*
 * return the cpu to which this intr should be bound.
 * Check properties or any other mechanism to see if user wants it
 * bound to a specific CPU. If so, return the cpu id with high bit set.
 * If not, use the policy to choose a cpu and return the id.
 */
uint32_t
apic_bind_intr(dev_info_t *dip, int irq, uchar_t ioapicid, uchar_t intin)
{
        int     instance, instno, prop_len, bind_cpu, count;
        uint_t  i, rc;
        uint32_t cpu;
        major_t major;
        char    *name, *drv_name, *prop_val, *cptr;
        char    prop_name[32];
        ulong_t iflag;


        if (apic_intr_policy == INTR_LOWEST_PRIORITY)
                return (IRQ_UNBOUND);

        if (apic_nproc == 1)
                return (0);

        /*
         * dip may be NULL for interrupts not associated with a device driver,
         * such as the ACPI SCI or HPET interrupts. In that case just use the
         * next CPU and return.
         */
        if (dip == NULL) {
                iflag = intr_clear();
                lock_set(&apic_ioapic_lock);
                bind_cpu = apic_get_next_bind_cpu();
                lock_clear(&apic_ioapic_lock);
                intr_restore(iflag);

                cmn_err(CE_CONT, "!%s: irq 0x%x "
                    "vector 0x%x ioapic 0x%x intin 0x%x is bound to cpu %d\n",
                    psm_name, irq, apic_irq_table[irq]->airq_vector, ioapicid,
                    intin, bind_cpu & ~IRQ_USER_BOUND);

                return ((uint32_t)bind_cpu);
        }

        name = ddi_get_name(dip);
        major = ddi_name_to_major(name);
        drv_name = ddi_major_to_name(major);
        instance = ddi_get_instance(dip);
        if (apic_intr_policy == INTR_ROUND_ROBIN_WITH_AFFINITY) {
                i = apic_min_device_irq;
                for (; i <= apic_max_device_irq; i++) {
                        if ((i == irq) || (apic_irq_table[i] == NULL) ||
                            (apic_irq_table[i]->airq_mps_intr_index
                            == FREE_INDEX))
                                continue;

                        if ((apic_irq_table[i]->airq_major == major) &&
                            (!(apic_irq_table[i]->airq_cpu & IRQ_USER_BOUND))) {
                                cpu = apic_irq_table[i]->airq_cpu;

                                cmn_err(CE_CONT,
                                    "!%s: %s (%s) instance #%d "
                                    "irq 0x%x vector 0x%x ioapic 0x%x "
                                    "intin 0x%x is bound to cpu %d\n",
                                    psm_name,
                                    name, drv_name, instance, irq,
                                    apic_irq_table[irq]->airq_vector,
                                    ioapicid, intin, cpu);
                                return (cpu);
                        }
                }
        }
        /*
         * search for "drvname"_intpt_bind_cpus property first, the
         * syntax of the property should be "a[,b,c,...]" where
         * instance 0 binds to cpu a, instance 1 binds to cpu b,
         * instance 3 binds to cpu c...
         * ddi_getlongprop() will search /option first, then /
         * if "drvname"_intpt_bind_cpus doesn't exist, then find
         * intpt_bind_cpus property.  The syntax is the same, and
         * it applies to all the devices if its "drvname" specific
         * property doesn't exist
         */
        (void) strcpy(prop_name, drv_name);
        (void) strcat(prop_name, "_intpt_bind_cpus");
        rc = ddi_getlongprop(DDI_DEV_T_ANY, dip, 0, prop_name,
            (caddr_t)&prop_val, &prop_len);
        if (rc != DDI_PROP_SUCCESS) {
                rc = ddi_getlongprop(DDI_DEV_T_ANY, dip, 0,
                    "intpt_bind_cpus", (caddr_t)&prop_val, &prop_len);
        }
        if (rc == DDI_PROP_SUCCESS) {
                for (i = count = 0; i < (prop_len - 1); i++)
                        if (prop_val[i] == ',')
                                count++;
                if (prop_val[i-1] != ',')
                        count++;
                /*
                 * if somehow the binding instances defined in the
                 * property are not enough for this instno., then
                 * reuse the pattern for the next instance until
                 * it reaches the requested instno
                 */
                instno = instance % count;
                i = 0;
                cptr = prop_val;
                while (i < instno)
                        if (*cptr++ == ',')
                                i++;
                bind_cpu = stoi(&cptr);
                kmem_free(prop_val, prop_len);
                /* if specific CPU is bogus, then default to next cpu */
                if (!apic_cpu_in_range(bind_cpu)) {
                        cmn_err(CE_WARN, "%s: %s=%s: CPU %d not present",
                            psm_name, prop_name, prop_val, bind_cpu);
                        rc = DDI_PROP_NOT_FOUND;
                } else {
                        /* indicate that we are bound at user request */
                        bind_cpu |= IRQ_USER_BOUND;
                }
                /*
                 * no need to check apic_cpus[].aci_status, if specific CPU is
                 * not up, then post_cpu_start will handle it.
                 */
        }

        if (rc != DDI_PROP_SUCCESS) {
                iflag = intr_clear();
                lock_set(&apic_ioapic_lock);
                bind_cpu = apic_get_next_bind_cpu();
                lock_clear(&apic_ioapic_lock);
                intr_restore(iflag);
        }

        cmn_err(CE_CONT, "!%s: %s (%s) instance %d irq 0x%x "
            "vector 0x%x ioapic 0x%x intin 0x%x is bound to cpu %d\n",
            psm_name, name, drv_name, instance, irq,
            apic_irq_table[irq]->airq_vector, ioapicid, intin,
            bind_cpu & ~IRQ_USER_BOUND);

        return ((uint32_t)bind_cpu);
}

/*
 * Mark vector as being in the process of being deleted. Interrupts
 * may still come in on some CPU. The moment an interrupt comes with
 * the new vector, we know we can free the old one. Called only from
 * addspl and delspl with interrupts disabled. Because an interrupt
 * can be shared, but no interrupt from either device may come in,
 * we also use a timeout mechanism, which we arbitrarily set to
 * apic_revector_timeout microseconds.
 */
static void
apic_mark_vector(uchar_t oldvector, uchar_t newvector)
{
        ulong_t iflag;

        iflag = intr_clear();
        lock_set(&apic_revector_lock);
        if (!apic_oldvec_to_newvec) {
                apic_oldvec_to_newvec =
                    kmem_zalloc(sizeof (newvector) * APIC_MAX_VECTOR * 2,
                    KM_NOSLEEP);

                if (!apic_oldvec_to_newvec) {
                        /*
                         * This failure is not catastrophic.
                         * But, the oldvec will never be freed.
                         */
                        apic_error |= APIC_ERR_MARK_VECTOR_FAIL;
                        lock_clear(&apic_revector_lock);
                        intr_restore(iflag);
                        return;
                }
                apic_newvec_to_oldvec = &apic_oldvec_to_newvec[APIC_MAX_VECTOR];
        }

        /* See if we already did this for drivers which do double addintrs */
        if (apic_oldvec_to_newvec[oldvector] != newvector) {
                apic_oldvec_to_newvec[oldvector] = newvector;
                apic_newvec_to_oldvec[newvector] = oldvector;
                apic_revector_pending++;
        }
        lock_clear(&apic_revector_lock);
        intr_restore(iflag);
        (void) timeout(apic_xlate_vector_free_timeout_handler,
            (void *)(uintptr_t)oldvector, drv_usectohz(apic_revector_timeout));
}

/*
 * xlate_vector is called from intr_enter if revector_pending is set.
 * It will xlate it if needed and mark the old vector as free.
 */
uchar_t
apic_xlate_vector(uchar_t vector)
{
        uchar_t newvector, oldvector = 0;

        lock_set(&apic_revector_lock);
        /* Do we really need to do this ? */
        if (!apic_revector_pending) {
                lock_clear(&apic_revector_lock);
                return (vector);
        }
        if ((newvector = apic_oldvec_to_newvec[vector]) != 0)
                oldvector = vector;
        else {
                /*
                 * The incoming vector is new . See if a stale entry is
                 * remaining
                 */
                if ((oldvector = apic_newvec_to_oldvec[vector]) != 0)
                        newvector = vector;
        }

        if (oldvector) {
                apic_revector_pending--;
                apic_oldvec_to_newvec[oldvector] = 0;
                apic_newvec_to_oldvec[newvector] = 0;
                apic_free_vector(oldvector);
                lock_clear(&apic_revector_lock);
                /* There could have been more than one reprogramming! */
                return (apic_xlate_vector(newvector));
        }
        lock_clear(&apic_revector_lock);
        return (vector);
}

void
apic_xlate_vector_free_timeout_handler(void *arg)
{
        ulong_t iflag;
        uchar_t oldvector, newvector;

        oldvector = (uchar_t)(uintptr_t)arg;
        iflag = intr_clear();
        lock_set(&apic_revector_lock);
        if ((newvector = apic_oldvec_to_newvec[oldvector]) != 0) {
                apic_free_vector(oldvector);
                apic_oldvec_to_newvec[oldvector] = 0;
                apic_newvec_to_oldvec[newvector] = 0;
                apic_revector_pending--;
        }

        lock_clear(&apic_revector_lock);
        intr_restore(iflag);
}

/*
 * Bind interrupt corresponding to irq_ptr to bind_cpu.
 * Must be called with interrupts disabled and apic_ioapic_lock held
 */
int
apic_rebind(apic_irq_t *irq_ptr, int bind_cpu,
    struct ioapic_reprogram_data *drep)
{
        int                     ioapicindex, intin_no;
        uint32_t                airq_temp_cpu;
        apic_cpus_info_t        *cpu_infop;
        uint32_t                rdt_entry;
        int                     which_irq;
        ioapic_rdt_t            irdt;

        which_irq = apic_vector_to_irq[irq_ptr->airq_vector];

        intin_no = irq_ptr->airq_intin_no;
        ioapicindex = irq_ptr->airq_ioapicindex;
        airq_temp_cpu = irq_ptr->airq_temp_cpu;
        if (airq_temp_cpu != IRQ_UNINIT && airq_temp_cpu != IRQ_UNBOUND) {
                if (airq_temp_cpu & IRQ_USER_BOUND)
                        /* Mask off high bit so it can be used as array index */
                        airq_temp_cpu &= ~IRQ_USER_BOUND;

                ASSERT(apic_cpu_in_range(airq_temp_cpu));
        }

        /*
         * Can't bind to a CPU that's not accepting interrupts:
         */
        cpu_infop = &apic_cpus[bind_cpu & ~IRQ_USER_BOUND];
        if (!(cpu_infop->aci_status & APIC_CPU_INTR_ENABLE))
                return (1);

        /*
         * If we are about to change the interrupt vector for this interrupt,
         * and this interrupt is level-triggered, attached to an IOAPIC,
         * has been delivered to a CPU and that CPU has not handled it
         * yet, we cannot reprogram the IOAPIC now.
         */
        if (!APIC_IS_MSI_OR_MSIX_INDEX(irq_ptr->airq_mps_intr_index)) {

                rdt_entry = READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapicindex,
                    intin_no);

                if ((irq_ptr->airq_vector != RDT_VECTOR(rdt_entry)) &&
                    apic_check_stuck_interrupt(irq_ptr, airq_temp_cpu,
                    bind_cpu, ioapicindex, intin_no, which_irq, drep) != 0) {

                        return (0);
                }

                /*
                 * NOTE: We do not unmask the RDT here, as an interrupt MAY
                 * still come in before we have a chance to reprogram it below.
                 * The reprogramming below will simultaneously change and
                 * unmask the RDT entry.
                 */

                if ((uint32_t)bind_cpu == IRQ_UNBOUND) {
                        irdt.ir_lo =  AV_LDEST | AV_LOPRI |
                            irq_ptr->airq_rdt_entry;

                        irdt.ir_hi = AV_TOALL >> APIC_ID_BIT_OFFSET;

                        apic_vt_ops->apic_intrmap_alloc_entry(
                            &irq_ptr->airq_intrmap_private, NULL,
                            DDI_INTR_TYPE_FIXED, 1, ioapicindex);
                        apic_vt_ops->apic_intrmap_map_entry(
                            irq_ptr->airq_intrmap_private, (void *)&irdt,
                            DDI_INTR_TYPE_FIXED, 1);
                        apic_vt_ops->apic_intrmap_record_rdt(
                            irq_ptr->airq_intrmap_private, &irdt);

                        /* Write the RDT entry -- no specific CPU binding */
                        WRITE_IOAPIC_RDT_ENTRY_HIGH_DWORD(ioapicindex, intin_no,
                            irdt.ir_hi | AV_TOALL);

                        if (airq_temp_cpu != IRQ_UNINIT && airq_temp_cpu !=
                            IRQ_UNBOUND)
                                apic_cpus[airq_temp_cpu].aci_temp_bound--;

                        /*
                         * Write the vector, trigger, and polarity portion of
                         * the RDT
                         */
                        WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapicindex, intin_no,
                            irdt.ir_lo);

                        irq_ptr->airq_temp_cpu = IRQ_UNBOUND;
                        return (0);
                }
        }

        if (bind_cpu & IRQ_USER_BOUND) {
                cpu_infop->aci_bound++;
        } else {
                cpu_infop->aci_temp_bound++;
        }
        ASSERT(apic_cpu_in_range(bind_cpu));

        if ((airq_temp_cpu != IRQ_UNBOUND) && (airq_temp_cpu != IRQ_UNINIT)) {
                apic_cpus[airq_temp_cpu].aci_temp_bound--;
        }
        if (!APIC_IS_MSI_OR_MSIX_INDEX(irq_ptr->airq_mps_intr_index)) {

                irdt.ir_lo = AV_PDEST | AV_FIXED | irq_ptr->airq_rdt_entry;
                irdt.ir_hi = cpu_infop->aci_local_id;

                apic_vt_ops->apic_intrmap_alloc_entry(
                    &irq_ptr->airq_intrmap_private, NULL, DDI_INTR_TYPE_FIXED,
                    1, ioapicindex);
                apic_vt_ops->apic_intrmap_map_entry(
                    irq_ptr->airq_intrmap_private,
                    (void *)&irdt, DDI_INTR_TYPE_FIXED, 1);
                apic_vt_ops->apic_intrmap_record_rdt(
                    irq_ptr->airq_intrmap_private, &irdt);

                /* Write the RDT entry -- bind to a specific CPU: */
                WRITE_IOAPIC_RDT_ENTRY_HIGH_DWORD(ioapicindex, intin_no,
                    irdt.ir_hi);

                /* Write the vector, trigger, and polarity portion of the RDT */
                WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapicindex, intin_no,
                    irdt.ir_lo);

        } else {
                int type = (irq_ptr->airq_mps_intr_index == MSI_INDEX) ?
                    DDI_INTR_TYPE_MSI : DDI_INTR_TYPE_MSIX;
                if (type == DDI_INTR_TYPE_MSI) {
                        if (irq_ptr->airq_ioapicindex ==
                            irq_ptr->airq_origirq) {
                                /* first one */
                                DDI_INTR_IMPLDBG((CE_CONT, "apic_rebind: call "
                                    "apic_pci_msi_enable_vector\n"));
                                apic_pci_msi_enable_vector(irq_ptr,
                                    type, which_irq, irq_ptr->airq_vector,
                                    irq_ptr->airq_intin_no,
                                    cpu_infop->aci_local_id);
                        }
                        if ((irq_ptr->airq_ioapicindex +
                            irq_ptr->airq_intin_no - 1) ==
                            irq_ptr->airq_origirq) { /* last one */
                                DDI_INTR_IMPLDBG((CE_CONT, "apic_rebind: call "
                                    "apic_pci_msi_enable_mode\n"));
                                apic_pci_msi_enable_mode(irq_ptr->airq_dip,
                                    type, which_irq);
                        }
                } else { /* MSI-X */
                        apic_pci_msi_enable_vector(irq_ptr, type,
                            irq_ptr->airq_origirq, irq_ptr->airq_vector, 1,
                            cpu_infop->aci_local_id);
                        apic_pci_msi_enable_mode(irq_ptr->airq_dip, type,
                            irq_ptr->airq_origirq);
                }
        }
        irq_ptr->airq_temp_cpu = (uint32_t)bind_cpu;
        apic_redist_cpu_skip &= ~(1 << (bind_cpu & ~IRQ_USER_BOUND));
        return (0);
}

static void
apic_last_ditch_clear_remote_irr(int ioapic_ix, int intin_no)
{
        if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix, intin_no)
            & AV_REMOTE_IRR) != 0) {
                /*
                 * Trying to clear the bit through normal
                 * channels has failed.  So as a last-ditch
                 * effort, try to set the trigger mode to
                 * edge, then to level.  This has been
                 * observed to work on many systems.
                 */
                WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no,
                    READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no) & ~AV_LEVEL);

                WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no,
                    READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no) | AV_LEVEL);

                /*
                 * If the bit's STILL set, this interrupt may
                 * be hosed.
                 */
                if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no) & AV_REMOTE_IRR) != 0) {

                        prom_printf("%s: Remote IRR still "
                            "not clear for IOAPIC %d intin %d.\n"
                            "\tInterrupts to this pin may cease "
                            "functioning.\n", psm_name, ioapic_ix,
                            intin_no);
#ifdef DEBUG
                        apic_last_ditch_reprogram_failures++;
#endif
                }
        }
}

/*
 * This function is protected by apic_ioapic_lock coupled with the
 * fact that interrupts are disabled.
 */
static void
delete_defer_repro_ent(int which_irq)
{
        ASSERT(which_irq >= 0);
        ASSERT(which_irq <= 255);
        ASSERT(LOCK_HELD(&apic_ioapic_lock));

        if (apic_reprogram_info[which_irq].done)
                return;

        apic_reprogram_info[which_irq].done = B_TRUE;

#ifdef DEBUG
        apic_defer_repro_total_retries +=
            apic_reprogram_info[which_irq].tries;

        apic_defer_repro_successes++;
#endif

        if (--apic_reprogram_outstanding == 0) {

                setlvlx = psm_intr_exit_fn();
        }
}


/*
 * Interrupts must be disabled during this function to prevent
 * self-deadlock.  Interrupts are disabled because this function
 * is called from apic_check_stuck_interrupt(), which is called
 * from apic_rebind(), which requires its caller to disable interrupts.
 */
static void
add_defer_repro_ent(apic_irq_t *irq_ptr, int which_irq, int new_bind_cpu)
{
        ASSERT(which_irq >= 0);
        ASSERT(which_irq <= 255);
        ASSERT(!interrupts_enabled());

        /*
         * On the off-chance that there's already a deferred
         * reprogramming on this irq, check, and if so, just update the
         * CPU and irq pointer to which the interrupt is targeted, then return.
         */
        if (!apic_reprogram_info[which_irq].done) {
                apic_reprogram_info[which_irq].bindcpu = new_bind_cpu;
                apic_reprogram_info[which_irq].irqp = irq_ptr;
                return;
        }

        apic_reprogram_info[which_irq].irqp = irq_ptr;
        apic_reprogram_info[which_irq].bindcpu = new_bind_cpu;
        apic_reprogram_info[which_irq].tries = 0;
        /*
         * This must be the last thing set, since we're not
         * grabbing any locks, apic_try_deferred_reprogram() will
         * make its decision about using this entry iff done
         * is false.
         */
        apic_reprogram_info[which_irq].done = B_FALSE;

        /*
         * If there were previously no deferred reprogrammings, change
         * setlvlx to call apic_try_deferred_reprogram()
         */
        if (++apic_reprogram_outstanding == 1) {

                setlvlx = apic_try_deferred_reprogram;
        }
}

static void
apic_try_deferred_reprogram(int prev_ipl, int irq)
{
        int reproirq;
        ulong_t iflag;
        struct ioapic_reprogram_data *drep;

        (*psm_intr_exit_fn())(prev_ipl, irq);

        if (!lock_try(&apic_defer_reprogram_lock)) {
                return;
        }

        /*
         * Acquire the apic_ioapic_lock so that any other operations that
         * may affect the apic_reprogram_info state are serialized.
         * It's still possible for the last deferred reprogramming to clear
         * between the time we entered this function and the time we get to
         * the for loop below.  In that case, *setlvlx will have been set
         * back to *_intr_exit and drep will be NULL. (There's no way to
         * stop that from happening -- we would need to grab a lock before
         * calling *setlvlx, which is neither realistic nor prudent).
         */
        iflag = intr_clear();
        lock_set(&apic_ioapic_lock);

        /*
         * For each deferred RDT entry, try to reprogram it now.  Note that
         * there is no lock acquisition to read apic_reprogram_info because
         * '.done' is set only after the other fields in the structure are set.
         */

        drep = NULL;
        for (reproirq = 0; reproirq <= APIC_MAX_VECTOR; reproirq++) {
                if (apic_reprogram_info[reproirq].done == B_FALSE) {
                        drep = &apic_reprogram_info[reproirq];
                        break;
                }
        }

        /*
         * Either we found a deferred action to perform, or
         * we entered this function spuriously, after *setlvlx
         * was restored to point to *_intr_exit.  Any other
         * permutation is invalid.
         */
        ASSERT(drep != NULL || *setlvlx == psm_intr_exit_fn());

        /*
         * Though we can't really do anything about errors
         * at this point, keep track of them for reporting.
         * Note that it is very possible for apic_setup_io_intr
         * to re-register this very timeout if the Remote IRR bit
         * has not yet cleared.
         */

#ifdef DEBUG
        if (drep != NULL) {
                if (apic_setup_io_intr(drep, reproirq, B_TRUE) != 0) {
                        apic_deferred_setup_failures++;
                }
        } else {
                apic_deferred_spurious_enters++;
        }
#else
        if (drep != NULL)
                (void) apic_setup_io_intr(drep, reproirq, B_TRUE);
#endif

        lock_clear(&apic_ioapic_lock);
        intr_restore(iflag);

        lock_clear(&apic_defer_reprogram_lock);
}

static void
apic_ioapic_wait_pending_clear(int ioapic_ix, int intin_no)
{
        int waited;

        /*
         * Wait for the delivery pending bit to clear.
         */
        if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix, intin_no) &
            (AV_LEVEL|AV_PENDING)) == (AV_LEVEL|AV_PENDING)) {

                /*
                 * If we're still waiting on the delivery of this interrupt,
                 * continue to wait here until it is delivered (this should be
                 * a very small amount of time, but include a timeout just in
                 * case).
                 */
                for (waited = 0; waited < apic_max_reps_clear_pending;
                    waited++) {
                        if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                            intin_no) & AV_PENDING) == 0) {
                                break;
                        }
                }
        }
}


/*
 * Checks to see if the IOAPIC interrupt entry specified has its Remote IRR
 * bit set.  Calls functions that modify the function that setlvlx points to,
 * so that the reprogramming can be retried very shortly.
 *
 * This function will mask the RDT entry if the interrupt is level-triggered.
 * (The caller is responsible for unmasking the RDT entry.)
 *
 * Returns non-zero if the caller should defer IOAPIC reprogramming.
 */
static int
apic_check_stuck_interrupt(apic_irq_t *irq_ptr, int old_bind_cpu,
    int new_bind_cpu, int ioapic_ix, int intin_no, int which_irq,
    struct ioapic_reprogram_data *drep)
{
        int32_t                 rdt_entry;
        int                     waited;
        int                     reps = 0;

        /*
         * Wait for the delivery pending bit to clear.
         */
        do {
                ++reps;

                apic_ioapic_wait_pending_clear(ioapic_ix, intin_no);

                /*
                 * Mask the RDT entry, but only if it's a level-triggered
                 * interrupt
                 */
                rdt_entry = READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                    intin_no);
                if ((rdt_entry & (AV_LEVEL|AV_MASK)) == AV_LEVEL) {

                        /* Mask it */
                        WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix, intin_no,
                            AV_MASK | rdt_entry);
                }

                if ((rdt_entry & AV_LEVEL) == AV_LEVEL) {
                        /*
                         * If there was a race and an interrupt was injected
                         * just before we masked, check for that case here.
                         * Then, unmask the RDT entry and try again.  If we're
                         * on our last try, don't unmask (because we want the
                         * RDT entry to remain masked for the rest of the
                         * function).
                         */
                        rdt_entry = READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                            intin_no);
                        if ((rdt_entry & AV_PENDING) &&
                            (reps < apic_max_reps_clear_pending)) {
                                /* Unmask it */
                                WRITE_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                                    intin_no, rdt_entry & ~AV_MASK);
                        }
                }

        } while ((rdt_entry & AV_PENDING) &&
            (reps < apic_max_reps_clear_pending));

#ifdef DEBUG
        if (rdt_entry & AV_PENDING)
                apic_intr_deliver_timeouts++;
#endif

        /*
         * If the remote IRR bit is set, then the interrupt has been sent
         * to a CPU for processing.  We have no choice but to wait for
         * that CPU to process the interrupt, at which point the remote IRR
         * bit will be cleared.
         */
        if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix, intin_no) &
            (AV_LEVEL|AV_REMOTE_IRR)) == (AV_LEVEL|AV_REMOTE_IRR)) {

                /*
                 * If the CPU that this RDT is bound to is NOT the current
                 * CPU, wait until that CPU handles the interrupt and ACKs
                 * it.  If this interrupt is not bound to any CPU (that is,
                 * if it's bound to the logical destination of "anyone"), it
                 * may have been delivered to the current CPU so handle that
                 * case by deferring the reprogramming (below).
                 */
                if ((old_bind_cpu != IRQ_UNBOUND) &&
                    (old_bind_cpu != IRQ_UNINIT) &&
                    (old_bind_cpu != psm_get_cpu_id())) {
                        for (waited = 0; waited < apic_max_reps_clear_pending;
                            waited++) {
                                if ((READ_IOAPIC_RDT_ENTRY_LOW_DWORD(ioapic_ix,
                                    intin_no) & AV_REMOTE_IRR) == 0) {

                                        delete_defer_repro_ent(which_irq);

                                        /* Remote IRR has cleared! */
                                        return (0);
                                }
                        }
                }

                /*
                 * If we waited and the Remote IRR bit is still not cleared,
                 * AND if we've invoked the timeout APIC_REPROGRAM_MAX_TIMEOUTS
                 * times for this interrupt, try the last-ditch workaround:
                 */
                if (drep && drep->tries >= APIC_REPROGRAM_MAX_TRIES) {

                        apic_last_ditch_clear_remote_irr(ioapic_ix, intin_no);

                        /* Mark this one as reprogrammed: */
                        delete_defer_repro_ent(which_irq);

                        return (0);
                } else {
#ifdef DEBUG
                        apic_intr_deferrals++;
#endif

                        /*
                         * If waiting for the Remote IRR bit (above) didn't
                         * allow it to clear, defer the reprogramming.
                         * Add a new deferred-programming entry if the
                         * caller passed a NULL one (and update the existing one
                         * in case anything changed).
                         */
                        add_defer_repro_ent(irq_ptr, which_irq, new_bind_cpu);
                        if (drep)
                                drep->tries++;

                        /* Inform caller to defer IOAPIC programming: */
                        return (1);
                }

        }

        /* Remote IRR is clear */
        delete_defer_repro_ent(which_irq);

        return (0);
}

/*
 * Called to migrate all interrupts at an irq to another cpu.
 * Must be called with interrupts disabled and apic_ioapic_lock held
 */
int
apic_rebind_all(apic_irq_t *irq_ptr, int bind_cpu)
{
        apic_irq_t      *irqptr = irq_ptr;
        int             retval = 0;

        while (irqptr) {
                if (irqptr->airq_temp_cpu != IRQ_UNINIT)
                        retval |= apic_rebind(irqptr, bind_cpu, NULL);
                irqptr = irqptr->airq_next;
        }

        return (retval);
}

/*
 * apic_intr_redistribute does all the messy computations for identifying
 * which interrupt to move to which CPU. Currently we do just one interrupt
 * at a time. This reduces the time we spent doing all this within clock
 * interrupt. When it is done in idle, we could do more than 1.
 * First we find the most busy and the most free CPU (time in ISR only)
 * skipping those CPUs that has been identified as being ineligible (cpu_skip)
 * Then we look for IRQs which are closest to the difference between the
 * most busy CPU and the average ISR load. We try to find one whose load
 * is less than difference.If none exists, then we chose one larger than the
 * difference, provided it does not make the most idle CPU worse than the
 * most busy one. In the end, we clear all the busy fields for CPUs. For
 * IRQs, they are cleared as they are scanned.
 */
void
apic_intr_redistribute(void)
{
        int busiest_cpu, most_free_cpu;
        int cpu_free, cpu_busy, max_busy, min_busy;
        int min_free, diff;
        int average_busy, cpus_online;
        int i, busy;
        ulong_t iflag;
        apic_cpus_info_t *cpu_infop;
        apic_irq_t *min_busy_irq = NULL;
        apic_irq_t *max_busy_irq = NULL;

        busiest_cpu = most_free_cpu = -1;
        cpu_free = cpu_busy = max_busy = average_busy = 0;
        min_free = apic_sample_factor_redistribution;
        cpus_online = 0;
        /*
         * Below we will check for CPU_INTR_ENABLE, bound, temp_bound, temp_cpu
         * without ioapic_lock. That is OK as we are just doing statistical
         * sampling anyway and any inaccuracy now will get corrected next time
         * The call to rebind which actually changes things will make sure
         * we are consistent.
         */
        for (i = 0; i < apic_nproc; i++) {
                if (apic_cpu_in_range(i) &&
                    !(apic_redist_cpu_skip & (1 << i)) &&
                    (apic_cpus[i].aci_status & APIC_CPU_INTR_ENABLE)) {

                        cpu_infop = &apic_cpus[i];
                        /*
                         * If no unbound interrupts or only 1 total on this
                         * CPU, skip
                         */
                        if (!cpu_infop->aci_temp_bound ||
                            (cpu_infop->aci_bound + cpu_infop->aci_temp_bound)
                            == 1) {
                                apic_redist_cpu_skip |= 1 << i;
                                continue;
                        }

                        busy = cpu_infop->aci_busy;
                        average_busy += busy;
                        cpus_online++;
                        if (max_busy < busy) {
                                max_busy = busy;
                                busiest_cpu = i;
                        }
                        if (min_free > busy) {
                                min_free = busy;
                                most_free_cpu = i;
                        }
                        if (busy > apic_int_busy_mark) {
                                cpu_busy |= 1 << i;
                        } else {
                                if (busy < apic_int_free_mark)
                                        cpu_free |= 1 << i;
                        }
                }
        }
        if ((cpu_busy && cpu_free) ||
            (max_busy >= (min_free + apic_diff_for_redistribution))) {

                apic_num_imbalance++;
#ifdef  DEBUG
                if (apic_verbose & APIC_VERBOSE_IOAPIC_FLAG) {
                        prom_printf(
                            "redistribute busy=%x free=%x max=%x min=%x",
                            cpu_busy, cpu_free, max_busy, min_free);
                }
#endif /* DEBUG */


                average_busy /= cpus_online;

                diff = max_busy - average_busy;
                min_busy = max_busy; /* start with the max possible value */
                max_busy = 0;
                min_busy_irq = max_busy_irq = NULL;
                i = apic_min_device_irq;
                for (; i <= apic_max_device_irq; i++) {
                        apic_irq_t *irq_ptr;
                        /* Change to linked list per CPU ? */
                        if ((irq_ptr = apic_irq_table[i]) == NULL)
                                continue;
                        /* Check for irq_busy & decide which one to move */
                        /* Also zero them for next round */
                        if ((irq_ptr->airq_temp_cpu == busiest_cpu) &&
                            irq_ptr->airq_busy) {
                                if (irq_ptr->airq_busy < diff) {
                                        /*
                                         * Check for least busy CPU,
                                         * best fit or what ?
                                         */
                                        if (max_busy < irq_ptr->airq_busy) {
                                                /*
                                                 * Most busy within the
                                                 * required differential
                                                 */
                                                max_busy = irq_ptr->airq_busy;
                                                max_busy_irq = irq_ptr;
                                        }
                                } else {
                                        if (min_busy > irq_ptr->airq_busy) {
                                                /*
                                                 * least busy, but more than
                                                 * the reqd diff
                                                 */
                                                if (min_busy <
                                                    (diff + average_busy -
                                                    min_free)) {
                                                        /*
                                                         * Making sure new cpu
                                                         * will not end up
                                                         * worse
                                                         */
                                                        min_busy =
                                                            irq_ptr->airq_busy;

                                                        min_busy_irq = irq_ptr;
                                                }
                                        }
                                }
                        }
                        irq_ptr->airq_busy = 0;
                }

                if (max_busy_irq != NULL) {
#ifdef  DEBUG
                        if (apic_verbose & APIC_VERBOSE_IOAPIC_FLAG) {
                                prom_printf("rebinding %x to %x",
                                    max_busy_irq->airq_vector, most_free_cpu);
                        }
#endif /* DEBUG */
                        iflag = intr_clear();
                        if (lock_try(&apic_ioapic_lock)) {
                                if (apic_rebind_all(max_busy_irq,
                                    most_free_cpu) == 0) {
                                        /* Make change permenant */
                                        max_busy_irq->airq_cpu =
                                            (uint32_t)most_free_cpu;
                                }
                                lock_clear(&apic_ioapic_lock);
                        }
                        intr_restore(iflag);

                } else if (min_busy_irq != NULL) {
#ifdef  DEBUG
                        if (apic_verbose & APIC_VERBOSE_IOAPIC_FLAG) {
                                prom_printf("rebinding %x to %x",
                                    min_busy_irq->airq_vector, most_free_cpu);
                        }
#endif /* DEBUG */

                        iflag = intr_clear();
                        if (lock_try(&apic_ioapic_lock)) {
                                if (apic_rebind_all(min_busy_irq,
                                    most_free_cpu) == 0) {
                                        /* Make change permenant */
                                        min_busy_irq->airq_cpu =
                                            (uint32_t)most_free_cpu;
                                }
                                lock_clear(&apic_ioapic_lock);
                        }
                        intr_restore(iflag);

                } else {
                        if (cpu_busy != (1 << busiest_cpu)) {
                                apic_redist_cpu_skip |= 1 << busiest_cpu;
                                /*
                                 * We leave cpu_skip set so that next time we
                                 * can choose another cpu
                                 */
                        }
                }
                apic_num_rebind++;
        } else {
                /*
                 * found nothing. Could be that we skipped over valid CPUs
                 * or we have balanced everything. If we had a variable
                 * ticks_for_redistribution, it could be increased here.
                 * apic_int_busy, int_free etc would also need to be
                 * changed.
                 */
                if (apic_redist_cpu_skip)
                        apic_redist_cpu_skip = 0;
        }
        for (i = 0; i < apic_nproc; i++) {
                if (apic_cpu_in_range(i)) {
                        apic_cpus[i].aci_busy = 0;
                }
        }
}

void
apic_cleanup_busy(void)
{
        int i;
        apic_irq_t *irq_ptr;

        for (i = 0; i < apic_nproc; i++) {
                if (apic_cpu_in_range(i)) {
                        apic_cpus[i].aci_busy = 0;
                }
        }

        for (i = apic_min_device_irq; i <= apic_max_device_irq; i++) {
                if ((irq_ptr = apic_irq_table[i]) != NULL)
                        irq_ptr->airq_busy = 0;
        }
}