/*
 * 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) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Copyright (c) 2010, Intel Corporation.
 * All rights reserved.
 * Copyright 2019 Joyent, Inc.
 * Copyright 2020 Oxide Computer Company
 */

/*
 * To understand how the pcplusmp module interacts with the interrupt subsystem
 * read the theory statement in uts/i86pc/os/intr.c.
 */

/*
 * 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/cram.h>
#include <sys/acpi/acpi.h>
#include <sys/acpica.h>
#include <sys/psm_common.h>
#include <sys/apic.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/prom_debug.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/sysmacros.h>
#include <sys/cpuvar.h>
#include <sys/rm_platter.h>
#include <sys/privregs.h>
#include <sys/note.h>
#include <sys/pci_intr_lib.h>
#include <sys/spl.h>
#include <sys/clock.h>
#include <sys/cyclic.h>
#include <sys/dditypes.h>
#include <sys/sunddi.h>
#include <sys/x_call.h>
#include <sys/reboot.h>
#include <sys/hpet.h>
#include <sys/apic_common.h>
#include <sys/apic_timer.h>
#include <sys/smt.h>

/*
 *      Local Function Prototypes
 */
static void apic_init_intr(void);

/*
 *      standard MP entries
 */
static int      apic_probe(void);
static int      apic_getclkirq(int ipl);
static void     apic_init(void);
static void     apic_picinit(void);
static int      apic_post_cpu_start(void);
static int      apic_intr_enter(int ipl, int *vect);
static void     apic_setspl(int ipl);
static int      apic_addspl(int ipl, int vector, int min_ipl, int max_ipl);
static int      apic_delspl(int ipl, int vector, int min_ipl, int max_ipl);
static int      apic_disable_intr(processorid_t cpun);
static void     apic_enable_intr(processorid_t cpun);
static int              apic_get_ipivect(int ipl, int type);
static void     apic_post_cyclic_setup(void *arg);

/*
 * The following vector assignments influence the value of ipltopri and
 * vectortoipl. Note that vectors 0 - 0x1f are not used. We can program
 * idle to 0 and IPL 0 to 0xf to differentiate idle in case
 * we care to do so in future. Note some IPLs which are rarely used
 * will share the vector ranges and heavily used IPLs (5 and 6) have
 * a wide range.
 *
 * This array is used to initialize apic_ipls[] (in apic_init()).
 *
 *      IPL             Vector range.           as passed to intr_enter
 *      0               none.
 *      1,2,3           0x20-0x2f               0x0-0xf
 *      4               0x30-0x3f               0x10-0x1f
 *      5               0x40-0x5f               0x20-0x3f
 *      6               0x60-0x7f               0x40-0x5f
 *      7,8,9           0x80-0x8f               0x60-0x6f
 *      10              0x90-0x9f               0x70-0x7f
 *      11              0xa0-0xaf               0x80-0x8f
 *      ...             ...
 *      15              0xe0-0xef               0xc0-0xcf
 *      15              0xf0-0xff               0xd0-0xdf
 */
uchar_t apic_vectortoipl[APIC_AVAIL_VECTOR / APIC_VECTOR_PER_IPL] = {
        3, 4, 5, 5, 6, 6, 9, 10, 11, 12, 13, 14, 15, 15
};
        /*
         * The ipl of an ISR at vector X is apic_vectortoipl[X>>4]
         * NOTE that this is vector as passed into intr_enter which is
         * programmed vector - 0x20 (APIC_BASE_VECT)
         */

uchar_t apic_ipltopri[MAXIPL + 1];      /* unix ipl to apic pri */
        /* The taskpri to be programmed into apic to mask given ipl */

/*
 * Correlation of the hardware vector to the IPL in use, initialized
 * from apic_vectortoipl[] in apic_init().  The final IPLs may not correlate
 * to the IPLs in apic_vectortoipl on some systems that share interrupt lines
 * connected to errata-stricken IOAPICs
 */
uchar_t apic_ipls[APIC_AVAIL_VECTOR];

/*
 * Patchable global variables.
 */
int     apic_enable_hwsoftint = 0;      /* 0 - disable, 1 - enable      */
int     apic_enable_bind_log = 1;       /* 1 - display interrupt binding log */

/*
 *      Local static data
 */
static struct   psm_ops apic_ops = {
        apic_probe,

        apic_init,
        apic_picinit,
        apic_intr_enter,
        apic_intr_exit,
        apic_setspl,
        apic_addspl,
        apic_delspl,
        apic_disable_intr,
        apic_enable_intr,
        (int (*)(int))NULL,             /* psm_softlvl_to_irq */
        (void (*)(int))NULL,            /* psm_set_softintr */

        apic_set_idlecpu,
        apic_unset_idlecpu,

        apic_clkinit,
        apic_getclkirq,
        (void (*)(void))NULL,           /* psm_hrtimeinit */
        apic_gethrtime,

        apic_get_next_processorid,
        apic_cpu_start,
        apic_post_cpu_start,
        apic_shutdown,
        apic_get_ipivect,
        apic_send_ipi,

        (int (*)(dev_info_t *, int))NULL,       /* psm_translate_irq */
        (void (*)(int, char *))NULL,    /* psm_notify_error */
        (void (*)(int))NULL,            /* psm_notify_func */
        apic_timer_reprogram,
        apic_timer_enable,
        apic_timer_disable,
        apic_post_cyclic_setup,
        apic_preshutdown,
        apic_intr_ops,                  /* Advanced DDI Interrupt framework */
        apic_state,                     /* save, restore apic state for S3 */
        apic_cpu_ops,                   /* CPU control interface. */

        apic_get_pir_ipivect,
        apic_send_pir_ipi,
        apic_cmci_setup,
};

struct psm_ops *psmops = &apic_ops;

static struct   psm_info apic_psm_info = {
        PSM_INFO_VER01_7,                       /* version */
        PSM_OWN_EXCLUSIVE,                      /* ownership */
        (struct psm_ops *)&apic_ops,            /* operation */
        APIC_PCPLUSMP_NAME,                     /* machine name */
        "pcplusmp v1.4 compatible",
};

static void *apic_hdlp;

/* to gather intr data and redistribute */
static void apic_redistribute_compute(void);

/*
 *      This is the loadable module wrapper
 */

int
_init(void)
{
        if (apic_coarse_hrtime)
                apic_ops.psm_gethrtime = &apic_gettime;
        return (psm_mod_init(&apic_hdlp, &apic_psm_info));
}

int
_fini(void)
{
        return (psm_mod_fini(&apic_hdlp, &apic_psm_info));
}

int
_info(struct modinfo *modinfop)
{
        return (psm_mod_info(&apic_hdlp, &apic_psm_info, modinfop));
}

static int
apic_probe(void)
{
        PRM_POINT("apic_probe()");

        /* check if apix is initialized */
        if (apix_enable && apix_loaded()) {
                PRM_POINT("apic_probe FAILURE: apix is loaded");
                return (PSM_FAILURE);
        }

        /*
         * Check whether x2APIC mode was activated by BIOS. We don't support
         * that in pcplusmp as apix normally handles that.
         */
        PRM_POINT("apic_local_mode()");
        if (apic_local_mode() == LOCAL_X2APIC) {
                PRM_POINT("apic_probe FAILURE: in x2apic mode");
                return (PSM_FAILURE);
        }

        /* continue using pcplusmp PSM */
        apix_enable = 0;

        return (apic_probe_common(apic_psm_info.p_mach_idstring));
}

static uchar_t
apic_xlate_vector_by_irq(uchar_t irq)
{
        if (apic_irq_table[irq] == NULL)
                return (0);

        return (apic_irq_table[irq]->airq_vector);
}

void
apic_init(void)
{
        int i;
        int     j = 1;

        psm_get_ioapicid = apic_get_ioapicid;
        psm_get_localapicid = apic_get_localapicid;
        psm_xlate_vector_by_irq = apic_xlate_vector_by_irq;

        apic_ipltopri[0] = APIC_VECTOR_PER_IPL; /* leave 0 for idle */
        for (i = 0; i < (APIC_AVAIL_VECTOR / APIC_VECTOR_PER_IPL); i++) {
                if ((i < ((APIC_AVAIL_VECTOR / APIC_VECTOR_PER_IPL) - 1)) &&
                    (apic_vectortoipl[i + 1] == apic_vectortoipl[i]))
                        /* get to highest vector at the same ipl */
                        continue;
                for (; j <= apic_vectortoipl[i]; j++) {
                        apic_ipltopri[j] = (i << APIC_IPL_SHIFT) +
                            APIC_BASE_VECT;
                }
        }
        for (; j < MAXIPL + 1; j++)
                /* fill up any empty ipltopri slots */
                apic_ipltopri[j] = (i << APIC_IPL_SHIFT) + APIC_BASE_VECT;
        apic_init_common();

        /*
         * For pcplusmp, we'll keep things simple and always disable this.
         */
        smt_intr_alloc_pil(XC_CPUPOKE_PIL);

        apic_pir_vect = apic_get_ipivect(XC_CPUPOKE_PIL, -1);

}

static void
apic_init_intr(void)
{
        processorid_t   cpun = psm_get_cpu_id();
        uint_t nlvt;
        uint32_t svr = AV_UNIT_ENABLE | APIC_SPUR_INTR;

        apic_reg_ops->apic_write_task_reg(APIC_MASK_ALL);

        ASSERT(apic_mode == LOCAL_APIC);

        /*
         * We are running APIC in MMIO mode.
         */
        if (apic_flat_model) {
                apic_reg_ops->apic_write(APIC_FORMAT_REG, APIC_FLAT_MODEL);
        } else {
                apic_reg_ops->apic_write(APIC_FORMAT_REG, APIC_CLUSTER_MODEL);
        }

        apic_reg_ops->apic_write(APIC_DEST_REG, AV_HIGH_ORDER >> cpun);

        if (apic_directed_EOI_supported()) {
                /*
                 * Setting the 12th bit in the Spurious Interrupt Vector
                 * Register suppresses broadcast EOIs generated by the local
                 * APIC. The suppression of broadcast EOIs happens only when
                 * interrupts are level-triggered.
                 */
                svr |= APIC_SVR_SUPPRESS_BROADCAST_EOI;
        }

        /* need to enable APIC before unmasking NMI */
        apic_reg_ops->apic_write(APIC_SPUR_INT_REG, svr);

        /*
         * Presence of an invalid vector with delivery mode AV_FIXED can
         * cause an error interrupt, even if the entry is masked...so
         * write a valid vector to LVT entries along with the mask bit
         */

        /* All APICs have timer and LINT0/1 */
        apic_reg_ops->apic_write(APIC_LOCAL_TIMER, AV_MASK|APIC_RESV_IRQ);
        apic_reg_ops->apic_write(APIC_INT_VECT0, AV_MASK|APIC_RESV_IRQ);
        apic_reg_ops->apic_write(APIC_INT_VECT1, AV_NMI);       /* enable NMI */

        /*
         * On integrated APICs, the number of LVT entries is
         * 'Max LVT entry' + 1; on 82489DX's (non-integrated
         * APICs), nlvt is "3" (LINT0, LINT1, and timer)
         */

        if (apic_cpus[cpun].aci_local_ver < APIC_INTEGRATED_VERS) {
                nlvt = 3;
        } else {
                nlvt = ((apic_reg_ops->apic_read(APIC_VERS_REG) >> 16) &
                    0xFF) + 1;
        }

        if (nlvt >= 5) {
                /* Enable performance counter overflow interrupt */

                if (!is_x86_feature(x86_featureset, X86FSET_MSR))
                        apic_enable_cpcovf_intr = 0;
                if (apic_enable_cpcovf_intr) {
                        if (apic_cpcovf_vect == 0) {
                                int ipl = APIC_PCINT_IPL;
                                int irq = apic_get_ipivect(ipl, -1);

                                ASSERT(irq != -1);
                                apic_cpcovf_vect =
                                    apic_irq_table[irq]->airq_vector;
                                ASSERT(apic_cpcovf_vect);
                                (void) add_avintr(NULL, ipl,
                                    (avfunc)kcpc_hw_overflow_intr,
                                    "apic pcint", irq, NULL, NULL, NULL, NULL);
                                kcpc_hw_overflow_intr_installed = 1;
                                kcpc_hw_enable_cpc_intr =
                                    apic_cpcovf_mask_clear;
                        }
                        apic_reg_ops->apic_write(APIC_PCINT_VECT,
                            apic_cpcovf_vect);
                }
        }

        if (nlvt >= 6) {
                /* Only mask TM intr if the BIOS apparently doesn't use it */

                uint32_t lvtval;

                lvtval = apic_reg_ops->apic_read(APIC_THERM_VECT);
                if (((lvtval & AV_MASK) == AV_MASK) ||
                    ((lvtval & AV_DELIV_MODE) != AV_SMI)) {
                        apic_reg_ops->apic_write(APIC_THERM_VECT,
                            AV_MASK|APIC_RESV_IRQ);
                }
        }

        /* Enable error interrupt */

        if (nlvt >= 4 && apic_enable_error_intr) {
                if (apic_errvect == 0) {
                        int ipl = 0xf;  /* get highest priority intr */
                        int irq = apic_get_ipivect(ipl, -1);

                        ASSERT(irq != -1);
                        apic_errvect = apic_irq_table[irq]->airq_vector;
                        ASSERT(apic_errvect);
                        /*
                         * Not PSMI compliant, but we are going to merge
                         * with ON anyway
                         */
                        (void) add_avintr((void *)NULL, ipl,
                            (avfunc)apic_error_intr, "apic error intr",
                            irq, NULL, NULL, NULL, NULL);
                }
                apic_reg_ops->apic_write(APIC_ERR_VECT, apic_errvect);
                apic_reg_ops->apic_write(APIC_ERROR_STATUS, 0);
                apic_reg_ops->apic_write(APIC_ERROR_STATUS, 0);
        }

        /*
         * Ensure a CMCI interrupt is allocated, regardless of whether it is
         * enabled or not.
         */
        if (apic_cmci_vect == 0) {
                const int ipl = 0x2;
                int irq = apic_get_ipivect(ipl, -1);

                ASSERT(irq != -1);
                apic_cmci_vect = apic_irq_table[irq]->airq_vector;
                ASSERT(apic_cmci_vect);

                (void) add_avintr(NULL, ipl,
                    (avfunc)cmi_cmci_trap,
                    "apic cmci intr", irq, NULL, NULL, NULL, NULL);
        }
}

static void
apic_picinit(void)
{
        int i, j;
        uint_t isr;

        /*
         * Initialize and enable interrupt remapping before apic
         * hardware initialization
         */
        apic_intrmap_init(apic_mode);

        /*
         * On UniSys Model 6520, the BIOS leaves vector 0x20 isr
         * bit on without clearing it with EOI.  Since softint
         * uses vector 0x20 to interrupt itself, so softint will
         * not work on this machine.  In order to fix this problem
         * a check is made to verify all the isr bits are clear.
         * If not, EOIs are issued to clear the bits.
         */
        for (i = 7; i >= 1; i--) {
                isr = apic_reg_ops->apic_read(APIC_ISR_REG + (i * 4));
                if (isr != 0)
                        for (j = 0; ((j < 32) && (isr != 0)); j++)
                                if (isr & (1 << j)) {
                                        apic_reg_ops->apic_write(
                                            APIC_EOI_REG, 0);
                                        isr &= ~(1 << j);
                                        apic_error |= APIC_ERR_BOOT_EOI;
                                }
        }

        /* set a flag so we know we have run apic_picinit() */
        apic_picinit_called = 1;
        LOCK_INIT_CLEAR(&apic_gethrtime_lock);
        LOCK_INIT_CLEAR(&apic_ioapic_lock);
        LOCK_INIT_CLEAR(&apic_error_lock);
        LOCK_INIT_CLEAR(&apic_mode_switch_lock);

        picsetup();      /* initialise the 8259 */

        /* add nmi handler - least priority nmi handler */
        LOCK_INIT_CLEAR(&apic_nmi_lock);

        if (!psm_add_nmintr(0, (avfunc) apic_nmi_intr,
            "pcplusmp NMI handler", (caddr_t)NULL))
                cmn_err(CE_WARN, "pcplusmp: Unable to add nmi handler");

        /*
         * Check for directed-EOI capability in the local APIC.
         */
        if (apic_directed_EOI_supported() == 1) {
                apic_set_directed_EOI_handler();
        }

        apic_init_intr();

        /* enable apic mode if imcr present */
        if (apic_imcrp) {
                outb(APIC_IMCR_P1, (uchar_t)APIC_IMCR_SELECT);
                outb(APIC_IMCR_P2, (uchar_t)APIC_IMCR_APIC);
        }

        ioapic_init_intr(IOAPIC_MASK);
}

#ifdef  DEBUG
void
apic_break(void)
{
}
#endif /* DEBUG */

/*
 * platform_intr_enter
 *
 *      Called at the beginning of the interrupt service routine to
 *      mask all level equal to and below the interrupt priority
 *      of the interrupting vector.  An EOI should be given to
 *      the interrupt controller to enable other HW interrupts.
 *
 *      Return -1 for spurious interrupts
 *
 */
/*ARGSUSED*/
static int
apic_intr_enter(int ipl, int *vectorp)
{
        uchar_t vector;
        int nipl;
        int irq;
        ulong_t iflag;
        apic_cpus_info_t *cpu_infop;

        /*
         * The real vector delivered is (*vectorp + 0x20), but our caller
         * subtracts 0x20 from the vector before passing it to us.
         * (That's why APIC_BASE_VECT is 0x20.)
         */
        vector = (uchar_t)*vectorp;

        /* if interrupted by the clock, increment apic_nsec_since_boot */
        if (vector == apic_clkvect) {
                if (!apic_oneshot) {
                        /* NOTE: this is not MT aware */
                        apic_hrtime_stamp++;
                        apic_nsec_since_boot += apic_nsec_per_intr;
                        apic_hrtime_stamp++;
                        last_count_read = apic_hertz_count;
                        apic_redistribute_compute();
                }

                /* We will avoid all the book keeping overhead for clock */
                nipl = apic_ipls[vector];

                *vectorp = apic_vector_to_irq[vector + APIC_BASE_VECT];

                apic_reg_ops->apic_write_task_reg(apic_ipltopri[nipl]);
                apic_reg_ops->apic_send_eoi(0);

                return (nipl);
        }

        cpu_infop = &apic_cpus[psm_get_cpu_id()];

        if (vector == (APIC_SPUR_INTR - APIC_BASE_VECT)) {
                cpu_infop->aci_spur_cnt++;
                return (APIC_INT_SPURIOUS);
        }

        /* Check if the vector we got is really what we need */
        if (apic_revector_pending) {
                /*
                 * Disable interrupts for the duration of
                 * the vector translation to prevent a self-race for
                 * the apic_revector_lock.  This cannot be done
                 * in apic_xlate_vector because it is recursive and
                 * we want the vector translation to be atomic with
                 * respect to other (higher-priority) interrupts.
                 */
                iflag = intr_clear();
                vector = apic_xlate_vector(vector + APIC_BASE_VECT) -
                    APIC_BASE_VECT;
                intr_restore(iflag);
        }

        nipl = apic_ipls[vector];
        *vectorp = irq = apic_vector_to_irq[vector + APIC_BASE_VECT];

        apic_reg_ops->apic_write_task_reg(apic_ipltopri[nipl]);

        cpu_infop->aci_current[nipl] = (uchar_t)irq;
        cpu_infop->aci_curipl = (uchar_t)nipl;
        cpu_infop->aci_ISR_in_progress |= 1 << nipl;

        /*
         * apic_level_intr could have been assimilated into the irq struct.
         * but, having it as a character array is more efficient in terms of
         * cache usage. So, we leave it as is.
         */
        if (!apic_level_intr[irq]) {
                apic_reg_ops->apic_send_eoi(0);
        }

#ifdef  DEBUG
        APIC_DEBUG_BUF_PUT(vector);
        APIC_DEBUG_BUF_PUT(irq);
        APIC_DEBUG_BUF_PUT(nipl);
        APIC_DEBUG_BUF_PUT(psm_get_cpu_id());
        if ((apic_stretch_interrupts) && (apic_stretch_ISR & (1 << nipl)))
                drv_usecwait(apic_stretch_interrupts);

        if (apic_break_on_cpu == psm_get_cpu_id())
                apic_break();
#endif /* DEBUG */
        return (nipl);
}

void
apic_intr_exit(int prev_ipl, int irq)
{
        apic_cpus_info_t *cpu_infop;

        apic_reg_ops->apic_write_task_reg(apic_ipltopri[prev_ipl]);

        cpu_infop = &apic_cpus[psm_get_cpu_id()];
        if (apic_level_intr[irq])
                apic_reg_ops->apic_send_eoi(irq);
        cpu_infop->aci_curipl = (uchar_t)prev_ipl;
        /* ISR above current pri could not be in progress */
        cpu_infop->aci_ISR_in_progress &= (2 << prev_ipl) - 1;
}

intr_exit_fn_t
psm_intr_exit_fn(void)
{
        return (apic_intr_exit);
}

/*
 * Mask all interrupts below or equal to the given IPL.
 */
static void
apic_setspl(int ipl)
{
        apic_reg_ops->apic_write_task_reg(apic_ipltopri[ipl]);

        /* interrupts at ipl above this cannot be in progress */
        apic_cpus[psm_get_cpu_id()].aci_ISR_in_progress &= (2 << ipl) - 1;
        /*
         * this is a patch fix for the ALR QSMP P5 machine, so that interrupts
         * have enough time to come in before the priority is raised again
         * during the idle() loop.
         */
        if (apic_setspl_delay)
                (void) apic_reg_ops->apic_get_pri();
}

/*ARGSUSED*/
static int
apic_addspl(int irqno, int ipl, int min_ipl, int max_ipl)
{
        return (apic_addspl_common(irqno, ipl, min_ipl, max_ipl));
}

static int
apic_delspl(int irqno, int ipl, int min_ipl, int max_ipl)
{
        return (apic_delspl_common(irqno, ipl, min_ipl,  max_ipl));
}

static int
apic_post_cpu_start(void)
{
        int cpun;
        static int cpus_started = 1;

        /* We know this CPU + BSP  started successfully. */
        cpus_started++;

        splx(ipltospl(LOCK_LEVEL));
        apic_init_intr();

        APIC_AV_PENDING_SET();

        /*
         * We may be booting, or resuming from suspend; aci_status will
         * be APIC_CPU_INTR_ENABLE if coming from suspend, so we add the
         * APIC_CPU_ONLINE flag here rather than setting aci_status completely.
         */
        cpun = psm_get_cpu_id();
        apic_cpus[cpun].aci_status |= APIC_CPU_ONLINE;

        apic_reg_ops->apic_write(APIC_DIVIDE_REG, apic_divide_reg_init);
        return (PSM_SUCCESS);
}

/*
 * type == -1 indicates it is an internal request. Do not change
 * resv_vector for these requests
 */
static int
apic_get_ipivect(int ipl, int type)
{
        uchar_t vector;
        int irq;

        if ((irq = apic_allocate_irq(APIC_VECTOR(ipl))) != -1) {
                if ((vector = apic_allocate_vector(ipl, irq, 1))) {
                        apic_irq_table[irq]->airq_mps_intr_index =
                            RESERVE_INDEX;
                        apic_irq_table[irq]->airq_vector = vector;
                        if (type != -1) {
                                apic_resv_vector[ipl] = vector;
                        }
                        return (irq);
                }
        }
        apic_error |= APIC_ERR_GET_IPIVECT_FAIL;
        return (-1);    /* shouldn't happen */
}

static int
apic_getclkirq(int ipl)
{
        int     irq;

        if ((irq = apic_get_ipivect(ipl, -1)) == -1)
                return (-1);
        /*
         * Note the vector in apic_clkvect for per clock handling.
         */
        apic_clkvect = apic_irq_table[irq]->airq_vector - APIC_BASE_VECT;
        APIC_VERBOSE_IOAPIC((CE_NOTE, "get_clkirq: vector = %x\n",
            apic_clkvect));
        return (irq);
}

/*
 * Try and disable all interrupts. We just assign interrupts to other
 * processors based on policy. If any were bound by user request, we
 * let them continue and return failure. We do not bother to check
 * for cache affinity while rebinding.
 */

static int
apic_disable_intr(processorid_t cpun)
{
        int bind_cpu = 0, i, hardbound = 0;
        apic_irq_t *irq_ptr;
        ulong_t iflag;

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

        for (i = 0; i <= APIC_MAX_VECTOR; i++) {
                if (apic_reprogram_info[i].done == B_FALSE) {
                        if (apic_reprogram_info[i].bindcpu == cpun) {
                                /*
                                 * CPU is busy -- it's the target of
                                 * a pending reprogramming attempt
                                 */
                                lock_clear(&apic_ioapic_lock);
                                intr_restore(iflag);
                                return (PSM_FAILURE);
                        }
                }
        }

        apic_cpus[cpun].aci_status &= ~APIC_CPU_INTR_ENABLE;

        apic_cpus[cpun].aci_curipl = 0;

        i = apic_min_device_irq;
        for (; i <= apic_max_device_irq; i++) {
                /*
                 * If there are bound interrupts on this cpu, then
                 * rebind them to other processors.
                 */
                if ((irq_ptr = apic_irq_table[i]) != NULL) {
                        ASSERT((irq_ptr->airq_temp_cpu == IRQ_UNBOUND) ||
                            (irq_ptr->airq_temp_cpu == IRQ_UNINIT) ||
                            (apic_cpu_in_range(irq_ptr->airq_temp_cpu)));

                        if (irq_ptr->airq_temp_cpu == (cpun | IRQ_USER_BOUND)) {
                                hardbound = 1;
                                continue;
                        }

                        if (irq_ptr->airq_temp_cpu == cpun) {
                                do {
                                        bind_cpu =
                                            apic_find_cpu(APIC_CPU_INTR_ENABLE);
                                } while (apic_rebind_all(irq_ptr, bind_cpu));
                        }
                }
        }

        lock_clear(&apic_ioapic_lock);
        intr_restore(iflag);

        if (hardbound) {
                cmn_err(CE_WARN, "Could not disable interrupts on %d"
                    "due to user bound interrupts", cpun);
                return (PSM_FAILURE);
        }
        else
                return (PSM_SUCCESS);
}

/*
 * Bind interrupts to the CPU's local APIC.
 * Interrupts should not be bound to a CPU's local APIC until the CPU
 * is ready to receive interrupts.
 */
static void
apic_enable_intr(processorid_t cpun)
{
        int     i;
        apic_irq_t *irq_ptr;
        ulong_t iflag;

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

        apic_cpus[cpun].aci_status |= APIC_CPU_INTR_ENABLE;

        i = apic_min_device_irq;
        for (i = apic_min_device_irq; i <= apic_max_device_irq; i++) {
                if ((irq_ptr = apic_irq_table[i]) != NULL) {
                        if ((irq_ptr->airq_cpu & ~IRQ_USER_BOUND) == cpun) {
                                (void) apic_rebind_all(irq_ptr,
                                    irq_ptr->airq_cpu);
                        }
                }
        }

        if (apic_cpus[cpun].aci_status & APIC_CPU_SUSPEND)
                apic_cpus[cpun].aci_status &= ~APIC_CPU_SUSPEND;

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

/*
 * If this module needs a periodic handler for the interrupt distribution, it
 * can be added here. The argument to the periodic handler is not currently
 * used, but is reserved for future.
 */
static void
apic_post_cyclic_setup(void *arg)
{
_NOTE(ARGUNUSED(arg))

        cyc_handler_t cyh;
        cyc_time_t cyt;

        /* cpu_lock is held */
        /* set up a periodic handler for intr redistribution */

        /*
         * In peridoc mode intr redistribution processing is done in
         * apic_intr_enter during clk intr processing
         */
        if (!apic_oneshot)
                return;

        /*
         * Register a periodical handler for the redistribution processing.
         * Though we would generally prefer to use the DDI interface for
         * periodic handler invocation, ddi_periodic_add(9F), we are
         * unfortunately already holding cpu_lock, which ddi_periodic_add will
         * attempt to take for us.  Thus, we add our own cyclic directly:
         */
        cyh.cyh_func = (void (*)(void *))apic_redistribute_compute;
        cyh.cyh_arg = NULL;
        cyh.cyh_level = CY_LOW_LEVEL;

        cyt.cyt_when = 0;
        cyt.cyt_interval = apic_redistribute_sample_interval;

        apic_cyclic_id = cyclic_add(&cyh, &cyt);
}

static void
apic_redistribute_compute(void)
{
        int     i, j, max_busy;

        if (apic_enable_dynamic_migration) {
                if (++apic_nticks == apic_sample_factor_redistribution) {
                        /*
                         * Time to call apic_intr_redistribute().
                         * reset apic_nticks. This will cause max_busy
                         * to be calculated below and if it is more than
                         * apic_int_busy, we will do the whole thing
                         */
                        apic_nticks = 0;
                }
                max_busy = 0;
                for (i = 0; i < apic_nproc; i++) {
                        if (!apic_cpu_in_range(i))
                                continue;

                        /*
                         * Check if curipl is non zero & if ISR is in
                         * progress
                         */
                        if (((j = apic_cpus[i].aci_curipl) != 0) &&
                            (apic_cpus[i].aci_ISR_in_progress & (1 << j))) {

                                int     irq;
                                apic_cpus[i].aci_busy++;
                                irq = apic_cpus[i].aci_current[j];
                                apic_irq_table[irq]->airq_busy++;
                        }

                        if (!apic_nticks &&
                            (apic_cpus[i].aci_busy > max_busy))
                                max_busy = apic_cpus[i].aci_busy;
                }
                if (!apic_nticks) {
                        if (max_busy > apic_int_busy_mark) {
                        /*
                         * We could make the following check be
                         * skipped > 1 in which case, we get a
                         * redistribution at half the busy mark (due to
                         * double interval). Need to be able to collect
                         * more empirical data to decide if that is a
                         * good strategy. Punt for now.
                         */
                                if (apic_skipped_redistribute) {
                                        apic_cleanup_busy();
                                        apic_skipped_redistribute = 0;
                                } else {
                                        apic_intr_redistribute();
                                }
                        } else
                                apic_skipped_redistribute++;
                }
        }
}


/*
 * The following functions are in the platform specific file so that they
 * can be different functions depending on whether we are running on
 * bare metal or a hypervisor.
 */

/*
 * Check to make sure there are enough irq slots
 */
int
apic_check_free_irqs(int count)
{
        int i, avail;

        avail = 0;
        for (i = APIC_FIRST_FREE_IRQ; i < APIC_RESV_IRQ; i++) {
                if ((apic_irq_table[i] == NULL) ||
                    apic_irq_table[i]->airq_mps_intr_index == FREE_INDEX) {
                        if (++avail >= count)
                                return (PSM_SUCCESS);
                }
        }
        return (PSM_FAILURE);
}

/*
 * This function allocates "count" MSI vector(s) for the given "dip/pri/type"
 */
int
apic_alloc_msi_vectors(dev_info_t *dip, int inum, int count, int pri,
    int behavior)
{
        int     rcount, i;
        uchar_t start, irqno;
        uint32_t cpu = 0;
        major_t major;
        apic_irq_t      *irqptr;

        DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msi_vectors: dip=0x%p "
            "inum=0x%x  pri=0x%x count=0x%x behavior=%d\n",
            (void *)dip, inum, pri, count, behavior));

        if (count > 1) {
                if (behavior == DDI_INTR_ALLOC_STRICT &&
                    apic_multi_msi_enable == 0)
                        return (0);
                if (apic_multi_msi_enable == 0)
                        count = 1;
        }

        if ((rcount = apic_navail_vector(dip, pri)) > count)
                rcount = count;
        else if (rcount == 0 || (rcount < count &&
            behavior == DDI_INTR_ALLOC_STRICT))
                return (0);

        /* if not ISP2, then round it down */
        if (!ISP2(rcount))
                rcount = 1 << (highbit(rcount) - 1);

        mutex_enter(&airq_mutex);

        for (start = 0; rcount > 0; rcount >>= 1) {
                if ((start = apic_find_multi_vectors(pri, rcount)) != 0 ||
                    behavior == DDI_INTR_ALLOC_STRICT)
                        break;
        }

        if (start == 0) {
                /* no vector available */
                mutex_exit(&airq_mutex);
                return (0);
        }

        if (apic_check_free_irqs(rcount) == PSM_FAILURE) {
                /* not enough free irq slots available */
                mutex_exit(&airq_mutex);
                return (0);
        }

        major = (dip != NULL) ? ddi_driver_major(dip) : 0;
        for (i = 0; i < rcount; i++) {
                if ((irqno = apic_allocate_irq(apic_first_avail_irq)) ==
                    (uchar_t)-1) {
                        /*
                         * shouldn't happen because of the
                         * apic_check_free_irqs() check earlier
                         */
                        mutex_exit(&airq_mutex);
                        DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msi_vectors: "
                            "apic_allocate_irq failed\n"));
                        return (i);
                }
                apic_max_device_irq = max(irqno, apic_max_device_irq);
                apic_min_device_irq = min(irqno, apic_min_device_irq);
                irqptr = apic_irq_table[irqno];
#ifdef  DEBUG
                if (apic_vector_to_irq[start + i] != APIC_RESV_IRQ)
                        DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msi_vectors: "
                            "apic_vector_to_irq is not APIC_RESV_IRQ\n"));
#endif
                apic_vector_to_irq[start + i] = (uchar_t)irqno;

                irqptr->airq_vector = (uchar_t)(start + i);
                irqptr->airq_ioapicindex = (uchar_t)inum;       /* start */
                irqptr->airq_intin_no = (uchar_t)rcount;
                ASSERT(pri >= 0 && pri <= UCHAR_MAX);
                irqptr->airq_ipl = (uchar_t)pri;
                irqptr->airq_vector = start + i;
                irqptr->airq_origirq = (uchar_t)(inum + i);
                irqptr->airq_share_id = 0;
                irqptr->airq_mps_intr_index = MSI_INDEX;
                irqptr->airq_dip = dip;
                irqptr->airq_major = major;
                if (i == 0) /* they all bound to the same cpu */
                        cpu = irqptr->airq_cpu = apic_bind_intr(dip, irqno,
                            0xff, 0xff);
                else
                        irqptr->airq_cpu = cpu;
                DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msi_vectors: irq=0x%x "
                    "dip=0x%p vector=0x%x origirq=0x%x pri=0x%x\n", irqno,
                    (void *)irqptr->airq_dip, irqptr->airq_vector,
                    irqptr->airq_origirq, pri));
        }
        mutex_exit(&airq_mutex);
        return (rcount);
}

/*
 * This function allocates "count" MSI-X vector(s) for the given "dip/pri/type"
 */
int
apic_alloc_msix_vectors(dev_info_t *dip, int inum, int count, int pri,
    int behavior)
{
        int     rcount, i;
        major_t major;

        mutex_enter(&airq_mutex);

        if ((rcount = apic_navail_vector(dip, pri)) > count)
                rcount = count;
        else if (rcount == 0 || (rcount < count &&
            behavior == DDI_INTR_ALLOC_STRICT)) {
                rcount = 0;
                goto out;
        }

        if (apic_check_free_irqs(rcount) == PSM_FAILURE) {
                /* not enough free irq slots available */
                rcount = 0;
                goto out;
        }

        major = (dip != NULL) ? ddi_driver_major(dip) : 0;
        for (i = 0; i < rcount; i++) {
                uchar_t vector, irqno;
                apic_irq_t      *irqptr;

                if ((irqno = apic_allocate_irq(apic_first_avail_irq)) ==
                    (uchar_t)-1) {
                        /*
                         * shouldn't happen because of the
                         * apic_check_free_irqs() check earlier
                         */
                        DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msix_vectors: "
                            "apic_allocate_irq failed\n"));
                        rcount = i;
                        goto out;
                }
                if ((vector = apic_allocate_vector(pri, irqno, 1)) == 0) {
                        /*
                         * shouldn't happen because of the
                         * apic_navail_vector() call earlier
                         */
                        DDI_INTR_IMPLDBG((CE_CONT, "apic_alloc_msix_vectors: "
                            "apic_allocate_vector failed\n"));
                        rcount = i;
                        goto out;
                }
                apic_max_device_irq = max(irqno, apic_max_device_irq);
                apic_min_device_irq = min(irqno, apic_min_device_irq);
                irqptr = apic_irq_table[irqno];
                irqptr->airq_vector = (uchar_t)vector;
                ASSERT(pri >= 0 && pri <= UCHAR_MAX);
                irqptr->airq_ipl = (uchar_t)pri;
                irqptr->airq_origirq = (uchar_t)(inum + i);
                irqptr->airq_share_id = 0;
                irqptr->airq_mps_intr_index = MSIX_INDEX;
                irqptr->airq_dip = dip;
                irqptr->airq_major = major;
                irqptr->airq_cpu = apic_bind_intr(dip, irqno, 0xff, 0xff);
        }
out:
        mutex_exit(&airq_mutex);
        return (rcount);
}

/*
 * Allocate a free vector for irq at ipl. Takes care of merging of multiple
 * IPLs into a single APIC level as well as stretching some IPLs onto multiple
 * levels. APIC_HI_PRI_VECTS interrupts are reserved for high priority
 * requests and allocated only when pri is set.
 */
uchar_t
apic_allocate_vector(int ipl, int irq, int pri)
{
        int     lowest, highest, i;

        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;

#ifdef  DEBUG
        if (apic_restrict_vector)       /* for testing shared interrupt logic */
                highest = lowest + apic_restrict_vector + APIC_HI_PRI_VECTS;
#endif /* DEBUG */
        if (pri == 0)
                highest -= APIC_HI_PRI_VECTS;

        for (i = lowest; i <= highest; i++) {
                if (APIC_CHECK_RESERVE_VECTORS(i))
                        continue;
                if (apic_vector_to_irq[i] == APIC_RESV_IRQ) {
                        apic_vector_to_irq[i] = (uchar_t)irq;
                        ASSERT(i >= 0 && i <= UCHAR_MAX);
                        return ((uchar_t)i);
                }
        }

        return (0);
}

/* Mark vector as not being used by any irq */
void
apic_free_vector(uchar_t vector)
{
        apic_vector_to_irq[vector] = APIC_RESV_IRQ;
}

/*
 * Call rebind to do the actual programming.
 * Must be called with interrupts disabled and apic_ioapic_lock held
 * 'p' is polymorphic -- if this function is called to process a deferred
 * reprogramming, p is of type 'struct ioapic_reprogram_data *', from which
 * the irq pointer is retrieved.  If not doing deferred reprogramming,
 * p is of the type 'apic_irq_t *'.
 *
 * apic_ioapic_lock must be held across this call, as it protects apic_rebind
 * and it protects apic_get_next_bind_cpu() from a race in which a CPU can be
 * taken offline after a cpu is selected, but before apic_rebind is called to
 * bind interrupts to it.
 */
int
apic_setup_io_intr(void *p, int irq, boolean_t deferred)
{
        apic_irq_t *irqptr;
        struct ioapic_reprogram_data *drep = NULL;
        int rv;

        if (deferred) {
                drep = (struct ioapic_reprogram_data *)p;
                ASSERT(drep != NULL);
                irqptr = drep->irqp;
        } else
                irqptr = (apic_irq_t *)p;

        ASSERT(irqptr != NULL);

        rv = apic_rebind(irqptr, apic_irq_table[irq]->airq_cpu, drep);
        if (rv) {
                /*
                 * CPU is not up or interrupts are disabled. Fall back to
                 * the first available CPU
                 */
                rv = apic_rebind(irqptr, apic_find_cpu(APIC_CPU_INTR_ENABLE),
                    drep);
        }

        return (rv);
}


uchar_t
apic_modify_vector(uchar_t vector, int irq)
{
        apic_vector_to_irq[vector] = (uchar_t)irq;
        return (vector);
}

char *
apic_get_apic_type(void)
{
        return (apic_psm_info.p_mach_idstring);
}

void
apic_switch_ipi_callback(boolean_t enter)
{
        ASSERT(enter == B_TRUE);
}

int
apic_detect_x2apic(void)
{
        return (0);
}

void
apic_enable_x2apic(void)
{
        cmn_err(CE_PANIC, "apic_enable_x2apic() called in pcplusmp");
}

void
x2apic_update_psm(void)
{
        cmn_err(CE_PANIC, "x2apic_update_psm() called in pcplusmp");
}