sun4v/pcbe/niagara2_pcbe.c

	niagara2_pcbe.c revision c6fc6a368e072b6deb37b62fe3f9895efc5316d1
/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * This file contains preset event names from the Performance Application
 * Programming Interface v3.5 which included the following notice:
 *
 *                             Copyright (c) 2005,6
 *                           Innovative Computing Labs
 *                         Computer Science Department,
 *                            University of Tennessee,
 *                                 Knoxville, TN.
 *                              All Rights Reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *    * Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the name of the University of Tennessee nor the names of its
 *      contributors may be used to endorse or promote products derived from
 *      this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * This open source software license conforms to the BSD License template.
 */

/*
 * Niagara2 Performance Counter Backend
 */

#include <sys/cpuvar.h>
#include <sys/systm.h>
#include <sys/archsystm.h>
#include <sys/cmn_err.h>
#include <sys/cpc_impl.h>
#include <sys/cpc_pcbe.h>
#include <sys/modctl.h>
#include <sys/machsystm.h>
#include <sys/sdt.h>
#include <sys/niagara2regs.h>
#include <sys/hsvc.h>
#include <sys/hypervisor_api.h>
#include <sys/disp.h>

/*LINTLIBRARY*/
static int ni2_pcbe_init(void);
static uint_t ni2_pcbe_ncounters(void);
static const char *ni2_pcbe_impl_name(void);
static const char *ni2_pcbe_cpuref(void);
static char *ni2_pcbe_list_events(uint_t picnum);
static char *ni2_pcbe_list_attrs(void);
static uint64_t ni2_pcbe_event_coverage(char *event);
static uint64_t ni2_pcbe_overflow_bitmap(void);
static int ni2_pcbe_configure(uint_t picnum, char *event, uint64_t preset,
    uint32_t flags, uint_t nattrs, kcpc_attr_t *attrs, void **data,
    void *token);
static void ni2_pcbe_program(void *token);
static void ni2_pcbe_allstop(void);
static void ni2_pcbe_sample(void *token);
static void ni2_pcbe_free(void *config);

extern void ultra_setpcr(uint64_t);
extern uint64_t ultra_getpcr(void);
extern void ultra_setpic(uint64_t);
extern uint64_t ultra_getpic(void);
extern uint64_t ultra_gettick(void);
extern char cpu_module_name[];

pcbe_ops_t ni2_pcbe_ops = {
    PCBE_VER_1,
    CPC_CAP_OVERFLOW_INTERRUPT | CPC_CAP_OVERFLOW_PRECISE,
    ni2_pcbe_ncounters,
    ni2_pcbe_impl_name,
    ni2_pcbe_cpuref,
    ni2_pcbe_list_events,
    ni2_pcbe_list_attrs,
    ni2_pcbe_event_coverage,
    ni2_pcbe_overflow_bitmap,
    ni2_pcbe_configure,
    ni2_pcbe_program,
    ni2_pcbe_allstop,
    ni2_pcbe_sample,
    ni2_pcbe_free
};

typedef struct _ni2_pcbe_config {
    uint_t      pcbe_picno; /* 0 for pic0 or 1 for pic1 */
    uint32_t    pcbe_evsel; /* %pcr event code unshifted */
    uint32_t    pcbe_flags; /* hpriv/user/system/priv */
    uint32_t    pcbe_pic;   /* unshifted raw %pic value */
} ni2_pcbe_config_t;

typedef struct _ni2_event {
    const char  *name;
    const uint32_t  emask;
    const uint32_t  emask_valid;    /* Mask of unreserved MASK bits */
} ni2_event_t;

typedef struct _ni2_generic_event {
    char *name;
    char *event;
} ni2_generic_event_t;

#define ULTRA_PCR_PRIVPIC   (UINT64_C(1) << CPC_PCR_PRIV_SHIFT)
#define EV_END {NULL, 0, 0}
#define GEN_EV_END {NULL, NULL}

static const uint64_t   allstopped = (ULTRA_PCR_PRIVPIC |
    CPC_PCR_HOLDOV0 | CPC_PCR_HOLDOV1);

/*
 * We update this array in the program and allstop routine. The array
 * is checked in the sample routine to allow us to only perform the
 * PCR.ht bit check when counting is in progress.
 */
static boolean_t ni2_cpc_counting[NCPU];

static ni2_event_t ni2_events[] = {
    { "Idle_strands",           0x000, 0x00 },
    { "Br_completed",           0x201, 0xff },
    { "Br_taken",               0x202, 0xff },
    { "Instr_FGU_arithmetic",       0x204, 0xff },
    { "Instr_ld",               0x208, 0xff },
    { "Instr_st",               0x210, 0xff },
    { "Instr_sw",               0x220, 0xff },
    { "Instr_other",            0x240, 0xff },
    { "Atomics",                0x280, 0xff },
    { "Instr_cnt",              0x2fd, 0xff },
    { "IC_miss",                0x301, 0x33 },
    { "DC_miss",                0x302, 0x33 },
    { "L2_imiss",               0x310, 0x33 },
    { "L2_dmiss_ld",            0x320, 0x33 },
    { "ITLB_HWTW_ref_L2",           0x404, 0x3c },
    { "DTLB_HWTW_ref_L2",           0x408, 0x3c },
    { "ITLB_HWTW_miss_L2",          0x410, 0x3c },
    { "DTLB_HWTW_miss_L2",          0x420, 0x3c },
    { "Stream_ld_to_PCX",           0x501, 0x3f },
    { "Stream_st_to_PCX",           0x502, 0x3f },
    { "CPU_ld_to_PCX",          0x504, 0x3f },
    { "CPU_ifetch_to_PCX",          0x508, 0x3f },
    { "CPU_st_to_PCX",          0x510, 0x3f },
    { "MMU_ld_to_PCX",          0x520, 0x3f },
#ifdef KT_IMPL
    { "DES_3DES_op",            0x601, 0xff },
    { "AES_op",             0x602, 0xff },
    { "Kasumi_op",              0x604, 0xff },
    { "MD5_SHA-1_SHA-256_op",       0x608, 0xff },
    { "MA_op",              0x610, 0xff },
    { "CRC_TCPIP_cksum",            0x620, 0xff },
    { "DES_3DES_busy_cycle",        0x701, 0xff },
    { "AES_busy_cycle",         0x702, 0xff },
    { "Kasumi_busy_cycle",          0x704, 0xff },
    { "MD5_SHA-1_SHA-256_busy_cycle",   0x708, 0xff },
    { "MA_busy_cycle",          0x710, 0xff },
    { "CRC_MPA_cksum",          0x720, 0xff },
#else
    { "DES_3DES_op",            0x601, 0x3f },
    { "AES_op",             0x602, 0x3f },
    { "RC4_op",             0x604, 0x3f },
    { "MD5_SHA-1_SHA-256_op",       0x608, 0x3f },
    { "MA_op",              0x610, 0x3f },
    { "CRC_TCPIP_cksum",            0x620, 0x3f },
    { "DES_3DES_busy_cycle",        0x701, 0x3f },
    { "AES_busy_cycle",         0x702, 0x3f },
    { "RC4_busy_cycle",         0x704, 0x3f },
    { "MD5_SHA-1_SHA-256_busy_cycle",   0x708, 0x3f },
    { "MA_busy_cycle",          0x710, 0x3f },
    { "CRC_MPA_cksum",          0x720, 0x3f },
#endif
    { "ITLB_miss",              0xb04, 0x0c },
    { "DTLB_miss",              0xb08, 0x0c },
    { "TLB_miss",               0xb0c, 0x0c },
    EV_END
};

static ni2_generic_event_t ni2_generic_events[] = {
    { "PAPI_tot_ins",   "Instr_cnt" },
    { "PAPI_l1_dcm",    "DC_miss" },
    { "PAPI_l1_icm",    "IC_miss" },
    { "PAPI_l2_icm",    "L2_imiss" },
    { "PAPI_l2_ldm",    "L2_dmiss_ld" },
    { "PAPI_tlb_dm",    "DTLB_miss" },
    { "PAPI_tlb_im",    "ITLB_miss" },
    { "PAPI_tlb_tm",    "TLB_miss" },
    { "PAPI_br_tkn",    "Br_taken" },
    { "PAPI_br_ins",    "Br_completed" },
    { "PAPI_ld_ins",    "Instr_ld" },
    { "PAPI_sr_ins",    "Instr_st" },
    { "PAPI_fp_ops",    "Instr_FGU_arithmetic" },
    { "PAPI_fp_ins",    "Instr_FGU_arithmetic" },
    GEN_EV_END
};

static char     *evlist;
static size_t       evlist_sz;
static uint16_t     pcr_pic0_mask;
static uint16_t     pcr_pic1_mask;

#define CPU_REF_URL " Documentation for Sun processors can be found at: " \
            "http://www.sun.com/processors/manuals"

#if defined(NIAGARA2_IMPL)
static const char   *cpu_impl_name = "UltraSPARC T2";
static const char *cpu_pcbe_ref = "See the \"UltraSPARC T2 User's Manual\" "
            "for descriptions of these events." CPU_REF_URL;
#elif defined(VFALLS_IMPL)
static const char   *cpu_impl_name = "UltraSPARC T2+";
static const char *cpu_pcbe_ref = "See the \"UltraSPARC T2+ User's Manual\" "
            "for descriptions of these events." CPU_REF_URL;
#elif defined(KT_IMPL)
static const char   *cpu_impl_name = "UltraSPARC T3";
static const char *cpu_pcbe_ref = "See the \"UltraSPARC T3 User's Manual\" "
            "for descriptions of these events." CPU_REF_URL;
#endif

static boolean_t cpu_hsvc_available = B_TRUE;

static int
ni2_pcbe_init(void)
{
    ni2_event_t     *evp;
    ni2_generic_event_t *gevp;
    int         status;
    uint64_t        cpu_hsvc_major;
    uint64_t        cpu_hsvc_minor;
#if defined(NIAGARA2_IMPL)
    uint64_t        hsvc_cpu_group = HSVC_GROUP_NIAGARA2_CPU;
    uint64_t        hsvc_cpu_major = NIAGARA2_HSVC_MAJOR;
#elif defined(VFALLS_IMPL)
    uint64_t        hsvc_cpu_group = HSVC_GROUP_VFALLS_CPU;
    uint64_t        hsvc_cpu_major = VFALLS_HSVC_MAJOR;
#elif defined(KT_IMPL)
    uint64_t    hsvc_cpu_group = HSVC_GROUP_KT_CPU;
    uint64_t    hsvc_cpu_major = KT_HSVC_MAJOR;
#endif

    pcr_pic0_mask = CPC_PCR_PIC0_MASK;
    pcr_pic1_mask = CPC_PCR_PIC1_MASK;

    /*
     * Validate API version for Niagara2 specific hypervisor services
     */
    status = hsvc_version(hsvc_cpu_group, &cpu_hsvc_major,
        &cpu_hsvc_minor);
    if ((status != 0) || (cpu_hsvc_major != hsvc_cpu_major)) {
        cmn_err(CE_WARN, "hypervisor services not negotiated "
            "or unsupported major number: group: 0x%lx major: 0x%lx "
            "minor: 0x%lx errno: %d", hsvc_cpu_group,
            cpu_hsvc_major, cpu_hsvc_minor, status);
        cpu_hsvc_available = B_FALSE;
    }

    /*
     * Construct event list.
     *
     * First pass:  Calculate size needed. We'll need an additional byte
     *      for the NULL pointer during the last strcat.
     *
     * Second pass: Copy strings.
     */
    for (evp = ni2_events; evp->name != NULL; evp++)
        evlist_sz += strlen(evp->name) + 1;

    for (gevp = ni2_generic_events; gevp->name != NULL; gevp++)
        evlist_sz += strlen(gevp->name) + 1;

    evlist = kmem_alloc(evlist_sz + 1, KM_SLEEP);
    evlist[0] = '\0';

    for (evp = ni2_events; evp->name != NULL; evp++) {
        (void) strcat(evlist, evp->name);
        (void) strcat(evlist, ",");
    }

    for (gevp = ni2_generic_events; gevp->name != NULL; gevp++) {
        (void) strcat(evlist, gevp->name);
        (void) strcat(evlist, ",");
    }

    /*
     * Remove trailing comma.
     */
    evlist[evlist_sz - 1] = '\0';

    return (0);
}

static uint_t
ni2_pcbe_ncounters(void)
{
    return (2);
}

static const char *
ni2_pcbe_impl_name(void)
{
    return (cpu_impl_name);
}

static const char *
ni2_pcbe_cpuref(void)
{
    return (cpu_pcbe_ref);
}

static char *
ni2_pcbe_list_events(uint_t picnum)
{
    ASSERT(picnum < cpc_ncounters);

    return (evlist);
}

static char *
ni2_pcbe_list_attrs(void)
{
    if (cpu_hsvc_available == B_TRUE)
#if defined(NIAGARA2_IMPL)
        return ("hpriv,emask");
#elif defined(VFALLS_IMPL)
        return ("hpriv,l2ctl,emask");
#elif defined(KT_IMPL)
        return ("hpriv,l2ctl,emask,sample");
#endif
    else
#if defined(KT_IMPL)
        return ("emask,sample");
#else
        return ("emask");
#endif
}

static ni2_generic_event_t *
find_generic_event(char *name)
{
    ni2_generic_event_t *gevp;

    for (gevp = ni2_generic_events; gevp->name != NULL; gevp++) {
        if (strcmp(name, gevp->name) == 0)
            return (gevp);
    }

    return (NULL);
}

static ni2_event_t *
find_event(char *name)
{
    ni2_event_t     *evp;

    for (evp = ni2_events; evp->name != NULL; evp++)
        if (strcmp(name, evp->name) == 0)
            return (evp);

    return (NULL);
}

/*ARGSUSED*/
static uint64_t
ni2_pcbe_event_coverage(char *event)
{
    /*
     * Check whether counter event is supported
     */
    if (find_event(event) == NULL && find_generic_event(event) == NULL)
        return (0);

    /*
     * Fortunately, both pic0 and pic1 can count all events.
     */
    return (0x3);
}

static uint64_t
ni2_pcbe_overflow_bitmap(void)
{
    uint64_t    pcr, overflow;
    uint64_t    pic;
    uint32_t    pic0, pic1;
    boolean_t   update_pic = B_FALSE;
    boolean_t   pic_inrange = B_FALSE;

    ASSERT(getpil() >= DISP_LEVEL);
    pcr = ultra_getpcr();
    DTRACE_PROBE1(niagara2__getpcr, uint64_t, pcr);
    overflow =  (pcr & CPC_PCR_OV0_MASK) >>
        CPC_PCR_OV0_SHIFT;
    overflow |=  (pcr & CPC_PCR_OV1_MASK) >>
        CPC_PCR_OV1_SHIFT;

    pic = ultra_getpic();
    pic0 = (uint32_t)(pic & PIC0_MASK);
    pic1 = (uint32_t)((pic >> PIC1_SHIFT) & PIC0_MASK);

    pcr |= (CPC_PCR_HOLDOV0 | CPC_PCR_HOLDOV1);

    if (overflow & 0x1) {
        pcr &= ~(CPC_PCR_OV0_MASK |
            CPC_PCR_HOLDOV0);
        pic_inrange = PIC_IN_OV_RANGE(pic0);
#if defined(KT_IMPL)
        if (pcr & CPC_PCR_SAMPLE_MODE_MASK)
            pic_inrange = SAMPLE_PIC_IN_OV_RANGE(pic0);
#endif
        if (pic_inrange) {
            pic0 = 0;
            update_pic = B_TRUE;
        }
    }

    if (overflow & 0x2) {
        pcr &= ~(CPC_PCR_OV1_MASK |
            CPC_PCR_HOLDOV1);
        pic_inrange = PIC_IN_OV_RANGE(pic1);
#if defined(KT_IMPL)
        if (pcr & CPC_PCR_SAMPLE_MODE_MASK)
            pic_inrange = SAMPLE_PIC_IN_OV_RANGE(pic1);
#endif
        if (pic_inrange) {
            pic1 = 0;
            update_pic = B_TRUE;
        }
    }

    if (update_pic)
        ultra_setpic(((uint64_t)pic1 << PIC1_SHIFT) | pic0);

    /*
     * The HV interface does not need to be used here because we are
     * only resetting the OV bits and do not need to set the HT bit.
     */
    DTRACE_PROBE1(niagara2__setpcr, uint64_t, pcr);
    ultra_setpcr(pcr);

    return (overflow);
}

/*ARGSUSED*/
static int
ni2_pcbe_configure(uint_t picnum, char *event, uint64_t preset, uint32_t flags,
    uint_t nattrs, kcpc_attr_t *attrs, void **data, void *token)
{
    ni2_pcbe_config_t   *cfg;
    ni2_pcbe_config_t   *other_config;
    ni2_event_t     *evp;
    ni2_generic_event_t *gevp;
    int         i;
    uint32_t        evsel;
#if defined(VFALLS_IMPL) || defined(KT_IMPL)
    uint64_t        l2ctl = 0;
#endif

    /*
     * If we've been handed an existing configuration, we need only preset
     * the counter value.
     */
    if (*data != NULL) {
        cfg = *data;
        cfg->pcbe_pic = (uint32_t)preset;
        return (0);
    }

    if (picnum > 1)
        return (CPC_INVALID_PICNUM);


    if ((evp = find_event(event)) == NULL) {
        if ((gevp = find_generic_event(event)) != NULL) {
            evp = find_event(gevp->event);
            ASSERT(evp != NULL);

            if (nattrs > 0)
                return (CPC_ATTRIBUTE_OUT_OF_RANGE);
        } else {
            return (CPC_INVALID_EVENT);
        }
    }

    evsel = evp->emask;

    for (i = 0; i < nattrs; i++) {
        if (strcmp(attrs[i].ka_name, "hpriv") == 0) {
            if (attrs[i].ka_val != 0)
                flags |= CPC_COUNT_HV;
        } else if (strcmp(attrs[i].ka_name, "emask") == 0) {
            if ((attrs[i].ka_val | evp->emask_valid) !=
                evp->emask_valid)
                return (CPC_ATTRIBUTE_OUT_OF_RANGE);
            evsel |= attrs[i].ka_val;
#if defined(VFALLS_IMPL) || defined(KT_IMPL)
        } else if (strcmp(attrs[i].ka_name, "l2ctl") == 0) {
            if ((attrs[i].ka_val | L2_CTL_MASK) !=
                L2_CTL_MASK)
                return (CPC_ATTRIBUTE_OUT_OF_RANGE);
            else
                l2ctl = attrs[i].ka_val;
#endif
#if defined(KT_IMPL)
        } else if (strcmp(attrs[i].ka_name, "sample") == 0) {
            if (attrs[i].ka_val != 0)
                flags |= CPC_COUNT_SAMPLE_MODE;
#endif
        } else
            return (CPC_INVALID_ATTRIBUTE);
    }

#if defined(VFALLS_IMPL) || defined(KT_IMPL)
    /*
     * Set PERF_CONTROL bits in L2_CONTROL_REG only when events have
     * SL bits equal to 3.
     */
    if ((evsel & SL3_MASK) == SL3_MASK) {
        if ((hv_niagara_setperf(HV_L2_CTL, l2ctl)) != 0)
            return (CPC_HV_NO_ACCESS);
    }
#endif

    /*
     * Find other requests that will be programmed with this one, and ensure
     * the flags don't conflict.
     */
    if (((other_config = kcpc_next_config(token, NULL, NULL)) != NULL) &&
        (other_config->pcbe_flags != flags))
        return (CPC_CONFLICTING_REQS);

    /*
     * If the hpriv attribute is present, make sure we have
     * access to hyperprivileged events before continuing with
     * this configuration. If we can set the ht bit in the PCR
     * successfully, we must have access to hyperprivileged
     * events.
     *
     * If this is a static per-CPU configuration, the CPC
     * driver ensures there can not be more than one for this
     * CPU. If this is a per-LWP configuration, the driver
     * ensures no static per-CPU counting is ongoing and that
     * the target LWP is not already being monitored.
     */
    if (flags & CPC_COUNT_HV) {
        kpreempt_disable();

        DTRACE_PROBE1(niagara2__setpcr, uint64_t,
            allstopped | CPC_PCR_HT);
        if (hv_niagara_setperf(HV_SPARC_CTL,
            allstopped | CPC_PCR_HT) != H_EOK) {
            kpreempt_enable();
            return (CPC_HV_NO_ACCESS);
        }

        DTRACE_PROBE1(niagara2__setpcr, uint64_t, allstopped);
        (void) hv_niagara_setperf(HV_SPARC_CTL, allstopped);

        kpreempt_enable();
    }

    cfg = kmem_alloc(sizeof (*cfg), KM_SLEEP);

    cfg->pcbe_picno = picnum;
    cfg->pcbe_evsel = evsel;
    cfg->pcbe_flags = flags;
    cfg->pcbe_pic = (uint32_t)preset;

    *data = cfg;
    return (0);
}

static void
ni2_pcbe_program(void *token)
{
    ni2_pcbe_config_t   *pic0;
    ni2_pcbe_config_t   *pic1;
    ni2_pcbe_config_t   *tmp;
    ni2_pcbe_config_t   nullcfg = { 1, 0, 0, 0 };
    uint64_t        pcr;
    uint64_t        curpic;
    uint64_t        toe;

    /* enable trap-on-event for pic0 and pic1 */
    toe = (CPC_PCR_TOE0 | CPC_PCR_TOE1);

    if ((pic0 = (ni2_pcbe_config_t *)kcpc_next_config(token, NULL, NULL)) ==
        NULL)
        panic("ni2_pcbe: token %p has no configs", token);

    if ((pic1 = kcpc_next_config(token, pic0, NULL)) == NULL) {
        pic1 = &nullcfg;
        nullcfg.pcbe_flags = pic0->pcbe_flags;
        toe = CPC_PCR_TOE0; /* enable trap-on-event for pic0 */
    }

    if (pic0->pcbe_picno != 0) {
        /*
         * pic0 is counter 1, so if we need the null config it should
         * be counter 0.
         */
        nullcfg.pcbe_picno = 0;
        tmp = pic0;
        pic0 = pic1;
        pic1 = tmp;
        toe = CPC_PCR_TOE1; /* enable trap-on-event for pic1 */
    }

    if (pic0->pcbe_picno != 0 || pic1->pcbe_picno != 1)
        panic("%s: bad config on token %p\n", cpu_impl_name, token);

    /*
     * UltraSPARC does not allow pic0 to be configured differently
     * from pic1. If the flags on these two configurations are
     * different, they are incompatible. This condition should be
     * caught at configure time.
     */
    ASSERT(pic0->pcbe_flags == pic1->pcbe_flags);

    ni2_pcbe_allstop();

    ultra_setpic(((uint64_t)pic1->pcbe_pic << PIC1_SHIFT) |
        (uint64_t)pic0->pcbe_pic);

    pcr = (pic0->pcbe_evsel & pcr_pic0_mask) << CPC_PCR_PIC0_SHIFT;
    pcr |= (pic1->pcbe_evsel & pcr_pic1_mask) <<
        CPC_PCR_PIC1_SHIFT;

    if (pic0->pcbe_flags & CPC_COUNT_USER)
        pcr |= (1ull << CPC_PCR_UT_SHIFT);
    if (pic0->pcbe_flags & CPC_COUNT_SYSTEM)
        pcr |= (1ull << CPC_PCR_ST_SHIFT);
    if (pic0->pcbe_flags & CPC_COUNT_HV)
        pcr |= (1ull << CPC_PCR_HT_SHIFT);
#if defined(KT_IMPL)
    if (pic0->pcbe_flags & CPC_COUNT_SAMPLE_MODE)
        pcr |= (1ull << CPC_PCR_SAMPLE_MODE_SHIFT);
#endif
    pcr |= toe;

    DTRACE_PROBE1(niagara2__setpcr, uint64_t, pcr);

    if (pic0->pcbe_flags & CPC_COUNT_HV) {
        /*
         * The ht bit in the PCR is only writable in
         * hyperprivileged mode. So if we are counting
         * hpriv events, we must use the HV interface
         * hv_niagara_setperf to set the PCR. If this
         * fails, assume we no longer have access to
         * hpriv events.
         */
        if (hv_niagara_setperf(HV_SPARC_CTL, pcr) != H_EOK) {
            kcpc_invalidate_config(token);
            return;
        }
    } else
        /* Set the PCR with no hpriv event counting enabled. */
        ultra_setpcr(pcr);

    ni2_cpc_counting[CPU->cpu_id] = B_TRUE;

    /*
     * On UltraSPARC, only read-to-read counts are accurate. We cannot
     * expect the value we wrote into the PIC, above, to be there after
     * starting the counter. We must sample the counter value now and use
     * that as the baseline for future samples.
     */
    curpic = ultra_getpic();
    pic0->pcbe_pic = (uint32_t)(curpic & PIC0_MASK);
    pic1->pcbe_pic = (uint32_t)(curpic >> PIC1_SHIFT);

    DTRACE_PROBE1(niagara2__newpic, uint64_t, curpic);
}

static void
ni2_pcbe_allstop(void)
{
    /*
     * We use the HV interface here because if we were counting
     * hyperprivileged events, we must reset the PCR.ht bit to stop
     * the counting. In the event that this HV call fails, we fall
     * back on ultra_setpcr which does not have write access to the
     * ht bit.
     */
    if (hv_niagara_setperf(HV_SPARC_CTL, allstopped) != H_EOK)
        ultra_setpcr(allstopped);

    ni2_cpc_counting[CPU->cpu_id] = B_FALSE;
}

static void
ni2_pcbe_sample(void *token)
{
    uint64_t        curpic;
    int64_t         diff;
    uint64_t        *pic0_data;
    uint64_t        *pic1_data;
    uint64_t        *dtmp;
    uint64_t        tmp;
    uint64_t        pcr;
    ni2_pcbe_config_t   *pic0;
    ni2_pcbe_config_t   *pic1;
    ni2_pcbe_config_t   nullcfg = { 1, 0, 0, 0 };
    ni2_pcbe_config_t   *ctmp;

    curpic = ultra_getpic();
    DTRACE_PROBE1(niagara2__getpic, uint64_t, curpic);

    if ((pic0 = kcpc_next_config(token, NULL, &pic0_data)) == NULL)
        panic("%s: token %p has no configs", cpu_impl_name, token);

    if ((pic1 = kcpc_next_config(token, pic0, &pic1_data)) == NULL) {
        pic1 = &nullcfg;
        pic1_data = &tmp;
    }

    if (pic0->pcbe_picno != 0) {
        nullcfg.pcbe_picno = 0;
        ctmp = pic0;
        pic0 = pic1;
        pic1 = ctmp;
        dtmp = pic0_data;
        pic0_data = pic1_data;
        pic1_data = dtmp;
    }

    if (pic0->pcbe_picno != 0 || pic1->pcbe_picno != 1)
        panic("%s: bad config on token %p\n", cpu_impl_name, token);


    if (pic0->pcbe_flags & CPC_COUNT_HV) {
        /*
         * If the hpriv attribute is present, but the HT bit
         * is not set in the PCR, access to hyperprivileged
         * events must have been revoked. Only perform this
         * check if counting is not stopped.
         */
        pcr = ultra_getpcr();
        DTRACE_PROBE1(niagara2__getpcr, uint64_t, pcr);
        if (ni2_cpc_counting[CPU->cpu_id] &&
            !(pcr & CPC_PCR_HT)) {
            kcpc_invalidate_config(token);
            return;
        }
    }

    diff = (curpic & PIC0_MASK) - (uint64_t)pic0->pcbe_pic;
    if (diff < 0)
        diff += (1ll << 32);
    *pic0_data += diff;

    diff = (curpic >> 32) - (uint64_t)pic1->pcbe_pic;
    if (diff < 0)
        diff += (1ll << 32);
    *pic1_data += diff;

    pic0->pcbe_pic = (uint32_t)(curpic & PIC0_MASK);
    pic1->pcbe_pic = (uint32_t)(curpic >> PIC1_SHIFT);
}

static void
ni2_pcbe_free(void *config)
{
    kmem_free(config, sizeof (ni2_pcbe_config_t));
}


static struct modlpcbe modlpcbe = {
    &mod_pcbeops,
#if defined(NIAGARA2_IMPL)
    "UltraSPARC T2 Performance Counters",
#elif defined(VFALLS_IMPL)
    "UltraSPARC T2+ Performance Counters",
#elif defined(KT_IMPL)
    "UltraSPARC T3 Performance Counters",
#endif
    &ni2_pcbe_ops
};

static struct modlinkage modl = {
    MODREV_1,
    &modlpcbe,
};

int
_init(void)
{
    if (ni2_pcbe_init() != 0)
        return (ENOTSUP);
    return (mod_install(&modl));
}

int
_fini(void)
{
    return (mod_remove(&modl));
}

int
_info(struct modinfo *mi)
{
    return (mod_info(&modl, mi));
}