/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018, Matthew Macy
 * Copyright (c) 2021, The FreeBSD Foundation
 *
 * Portions of this software were developed by Mitchell Horne
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/pmc.h>
#include <sys/sysctl.h>
#include <stddef.h>
#include <stdlib.h>
#include <limits.h>
#include <regex.h>
#include <string.h>
#include <pmc.h>
#include <pmclog.h>
#include <assert.h>
#include <libpmcstat.h>
#include "pmu-events/pmu-events.h"

struct pmu_alias {
        const char *pa_alias;
        const char *pa_name;
};

#if defined(__amd64__) || defined(__i386__)
typedef enum {
        PMU_INVALID,
        PMU_INTEL,
        PMU_AMD,
} pmu_mfr_t;

static struct pmu_alias pmu_intel_alias_table[] = {
        {"UNHALTED_CORE_CYCLES", "cpu_clk_unhalted.thread"},
        {"UNHALTED-CORE-CYCLES", "cpu_clk_unhalted.thread"},
        {"LLC_MISSES", "LONGEST_LAT_CACHE.MISS"},
        {"LLC-MISSES", "LONGEST_LAT_CACHE.MISS"},
        {"LLC_REFERENCE", "LONGEST_LAT_CACHE.REFERENCE"},
        {"LLC-REFERENCE", "LONGEST_LAT_CACHE.REFERENCE"},
        {"LLC_MISS_RHITM", "mem_load_l3_miss_retired.remote_hitm"},
        {"LLC-MISS-RHITM", "mem_load_l3_miss_retired.remote_hitm"},
        {"RESOURCE_STALL", "RESOURCE_STALLS.ANY"},
        {"RESOURCE_STALLS_ANY", "RESOURCE_STALLS.ANY"},
        {"BRANCH_INSTRUCTION_RETIRED", "BR_INST_RETIRED.ALL_BRANCHES"},
        {"BRANCH-INSTRUCTION-RETIRED", "BR_INST_RETIRED.ALL_BRANCHES"},
        {"BRANCH_MISSES_RETIRED", "BR_MISP_RETIRED.ALL_BRANCHES"},
        {"BRANCH-MISSES-RETIRED", "BR_MISP_RETIRED.ALL_BRANCHES"},
        {"unhalted-cycles", "cpu_clk_unhalted.thread"},
        {"instructions", "inst_retired.any"},
        {"branch-mispredicts", "br_misp_retired.all_branches"},
        {"branches", "br_inst_retired.all_branches"},
        {"interrupts", "hw_interrupts.received"},
        {"ic-misses", "frontend_retired.l1i_miss"},
        {NULL, NULL},
};

static struct pmu_alias pmu_amd_alias_table[] = {
        {"UNHALTED_CORE_CYCLES", "ls_not_halted_cyc"},
        {"UNHALTED-CORE-CYCLES", "ls_not_halted_cyc"},
        {"LLC_MISSES", "l3_comb_clstr_state.request_miss"},
        {"LLC-MISSES", "l3_comb_clstr_state.request_miss"},
        {"LLC_REFERENCE", "l3_request_g1.caching_l3_cache_accesses"},
        {"LLC-REFERENCE", "l3_request_g1.caching_l3_cache_accesses"},
        {"BRANCH_INSTRUCTION_RETIRED", "ex_ret_brn"},
        {"BRANCH-INSTRUCTION-RETIRED", "ex_ret_brn"},
        {"BRANCH_MISSES_RETIRED", "ex_ret_brn_misp"},
        {"BRANCH-MISSES-RETIRED", "ex_ret_brn_misp"},
        {"unhalted-cycles", "ls_not_halted_cyc"},
        {"instructions", "ex_ret_instr",},
        {"branch-mispredicts", "ex_ret_brn_misp"},
        {"branches", "ex_ret_brn"},
        {"interrupts", "ls_int_taken"}, /* Not on amdzen1 */
        {NULL, NULL},
};


static pmu_mfr_t
pmu_events_mfr(void)
{
        char buf[PMC_CPUID_LEN];
        size_t s = sizeof(buf);
        pmu_mfr_t mfr;

        if (sysctlbyname("kern.hwpmc.cpuid", buf, &s,
            (void *)NULL, 0) == -1)
                return (PMU_INVALID);
        if (strcasestr(buf, "AuthenticAMD") != NULL ||
            strcasestr(buf, "HygonGenuine") != NULL)
                mfr = PMU_AMD;
        else if (strcasestr(buf, "GenuineIntel") != NULL)
                mfr = PMU_INTEL;
        else
                mfr = PMU_INVALID;
        return (mfr);
}

static int
pmu_events_x86_family(void)
{
        char buf[PMC_CPUID_LEN];
        size_t s = sizeof(buf);
        char *cpuid, *family;

        if (sysctlbyname("kern.hwpmc.cpuid", buf, &s,
            (void *)NULL, 0) == -1)
                return (-1);
        cpuid = &buf[0];

        strsep(&cpuid, "-");
        family = strsep(&cpuid, "-");

        return (strtol(family, NULL, 10));
}

/*
 *  The Intel fixed mode counters are:
 *      "inst_retired.any",
 *      "cpu_clk_unhalted.thread",
 *      "cpu_clk_unhalted.thread_any",
 *      "cpu_clk_unhalted.ref_tsc",
 *
 */

static const char *
pmu_alias_get(const char *name)
{
        pmu_mfr_t mfr;
        struct pmu_alias *pa;
        struct pmu_alias *pmu_alias_table;

        if ((mfr = pmu_events_mfr()) == PMU_INVALID)
                return (name);
        if (mfr == PMU_AMD)
                pmu_alias_table = pmu_amd_alias_table;
        else if (mfr == PMU_INTEL)
                pmu_alias_table = pmu_intel_alias_table;
        else
                return (name);

        for (pa = pmu_alias_table; pa->pa_alias != NULL; pa++)
                if (strcasecmp(name, pa->pa_alias) == 0)
                        return (pa->pa_name);

        return (name);
}
#elif defined(__powerpc64__)

static const char *
pmu_alias_get(const char *name)
{
        return (name);
}

#elif defined(__aarch64__)

static struct pmu_alias pmu_armv8_alias_table[] = {
        {"UNHALTED_CORE_CYCLES", "CPU_CYCLES"},
        {"UNHALTED-CORE-CYCLES", "CPU_CYCLES"},
        {"LLC_MISSES", "LL_CACHE_MISS_RD"},
        {"LLC-MISSES", "LL_CACHE_MISS_RD"},
        {"LLC_REFERENCE", "LL_CACHE_RD"},
        {"LLC-REFERENCE", "LL_CACHE_RD"},
        {"BRANCH_INSTRUCTION_RETIRED", "BR_RETIRED"},
        {"BRANCH-INSTRUCTION-RETIRED", "BR_RETIRED"},
        {"BRANCH_MISSES_RETIRED", "BR_MIS_PRED_RETIRED"},
        {"BRANCH-MISSES-RETIRED", "BR_MIS_PRED_RETIRED"},
        {"unhalted-cycles", "CPU_CYCLES"},
        {"instructions", "INST_RETIRED",},
        {"branch-mispredicts", "BR_MIS_PRED_RETIRED"},
        {"branches", "BR_RETIRED"},
        {"interrupts", "EXC_IRQ"},
        {NULL, NULL},
};

static const char *
pmu_alias_get(const char *name)
{
        struct pmu_alias *pa;

        for (pa = pmu_armv8_alias_table; pa->pa_alias != NULL; pa++)
                if (strcasecmp(name, pa->pa_alias) == 0)
                        return (pa->pa_name);

        return (name);
}

#else

static const char *
pmu_alias_get(const char *name)
{

        return (name);
}
#endif

struct pmu_event_desc {
        uint64_t ped_period;
        uint64_t ped_offcore_rsp;
        uint64_t ped_l3_thread;
        uint64_t ped_l3_slice;
        uint32_t ped_sourceid;
        uint32_t ped_coreid;
        uint32_t ped_allsources;
        uint32_t ped_allcores;
        uint32_t ped_event;
        uint32_t ped_frontend;
        uint32_t ped_ldlat;
        uint32_t ped_config1;
        int16_t ped_umask;
        uint8_t ped_cmask;
        uint8_t ped_any;
        uint8_t ped_inv;
        uint8_t ped_edge;
        uint8_t ped_fc_mask;
        uint8_t ped_ch_mask;
        uint8_t ped_pebs;
};

static const struct pmu_events_map *
pmu_events_map_get(const char *cpuid)
{
        regex_t re;
        regmatch_t pmatch[1];
        char buf[PMC_CPUID_LEN];
        size_t s = sizeof(buf);
        int match;
        const struct pmu_events_map *pme;

        if (cpuid != NULL) {
                strlcpy(buf, cpuid, s);
        } else {
                if (sysctlbyname("kern.hwpmc.cpuid", buf, &s,
                    (void *)NULL, 0) == -1)
                        return (NULL);
        }
        for (pme = pmu_events_map; pme->cpuid != NULL; pme++) {
                if (regcomp(&re, pme->cpuid, REG_EXTENDED) != 0) {
                        printf("regex '%s' failed to compile, ignoring\n",
                            pme->cpuid);
                        continue;
                }
                match = regexec(&re, buf, 1, pmatch, 0);
                regfree(&re);
                if (match == 0) {
                        if (pmatch[0].rm_so == 0 && (buf[pmatch[0].rm_eo] == 0
                            || buf[pmatch[0].rm_eo] == '-'))
                                return (pme);
                }
        }
        return (NULL);
}

static const struct pmu_event *
pmu_event_get(const char *cpuid, const char *event_name, int *idx)
{
        const struct pmu_events_map *pme;
        const struct pmu_event *pe;
        int i;

        if ((pme = pmu_events_map_get(cpuid)) == NULL)
                return (NULL);
        for (i = 0, pe = pme->table; pe->name || pe->desc || pe->event; pe++, i++) {
                if (pe->name == NULL)
                        continue;
                if (strcasecmp(pe->name, event_name) == 0) {
                        if (idx)
                                *idx = i;
                        return (pe);
                }
        }
        return (NULL);
}

int
pmc_pmu_idx_get_by_event(const char *cpuid, const char *event)
{
        int idx;
        const char *realname;

        realname = pmu_alias_get(event);
        if (pmu_event_get(cpuid, realname, &idx) == NULL)
                return (-1);
        return (idx);
}

const char *
pmc_pmu_event_get_by_idx(const char *cpuid, int idx)
{
        const struct pmu_events_map *pme;

        if ((pme = pmu_events_map_get(cpuid)) == NULL)
                return (NULL);
        assert(pme->table[idx].name);
        return (pme->table[idx].name);
}

static int
pmu_parse_event(struct pmu_event_desc *ped, const char *eventin)
{
        char *event;
        char *kvp, *key, *value, *r;
        char *debug;

        if ((event = strdup(eventin)) == NULL)
                return (ENOMEM);
        r = event;
        bzero(ped, sizeof(*ped));
        ped->ped_period = DEFAULT_SAMPLE_COUNT;
        ped->ped_umask = -1;
        while ((kvp = strsep(&event, ",")) != NULL) {
                key = strsep(&kvp, "=");
                if (key == NULL)
                        abort();
                value = kvp;
                if (strcmp(key, "umask") == 0)
                        ped->ped_umask = strtol(value, NULL, 16);
                else if (strcmp(key, "event") == 0)
                        ped->ped_event = strtol(value, NULL, 16);
                else if (strcmp(key, "period") == 0)
                        ped->ped_period = strtol(value, NULL, 10);
                else if (strcmp(key, "offcore_rsp") == 0)
                        ped->ped_offcore_rsp = strtol(value, NULL, 16);
                else if (strcmp(key, "any") == 0)
                        ped->ped_any = strtol(value, NULL, 10);
                else if (strcmp(key, "cmask") == 0)
                        ped->ped_cmask = strtol(value, NULL, 10);
                else if (strcmp(key, "inv") == 0)
                        ped->ped_inv = strtol(value, NULL, 10);
                else if (strcmp(key, "edge") == 0)
                        ped->ped_edge = strtol(value, NULL, 10);
                else if (strcmp(key, "frontend") == 0)
                        ped->ped_frontend = strtol(value, NULL, 16);
                else if (strcmp(key, "ldlat") == 0)
                        ped->ped_ldlat = strtol(value, NULL, 16);
                else if (strcmp(key, "fc_mask") == 0)
                        ped->ped_fc_mask = strtol(value, NULL, 16);
                else if (strcmp(key, "ch_mask") == 0)
                        ped->ped_ch_mask = strtol(value, NULL, 16);
                else if (strcmp(key, "config1") == 0)
                        ped->ped_config1 = strtol(value, NULL, 16);
                else if (strcmp(key, "l3_thread_mask") == 0)
                        ped->ped_l3_thread = strtol(value, NULL, 16);
                else if (strcmp(key, "l3_slice_mask") == 0)
                        ped->ped_l3_slice = strtol(value, NULL, 16);
                else if (strcmp(key, "sourceid") == 0)
                        ped->ped_sourceid = strtol(value, NULL, 16);
                else if (strcmp(key, "coreid") == 0)
                        ped->ped_coreid = strtol(value, NULL, 16);
                else if (strcmp(key, "allcores") == 0)
                        ped->ped_allcores = strtol(value, NULL, 10);
                else if (strcmp(key, "allsources") == 0)
                        ped->ped_allsources = strtol(value, NULL, 10);
                else if (strcmp(key, "pebs") == 0)
                        ped->ped_pebs = strtol(value, NULL, 10);
                else {
                        debug = getenv("PMUDEBUG");
                        if (debug != NULL && strcmp(debug, "true") == 0 && value != NULL)
                                printf("unrecognized kvpair: %s:%s\n", key, value);
                }
        }
        free(r);
        return (0);
}

uint64_t
pmc_pmu_sample_rate_get(const char *event_name)
{
        const struct pmu_event *pe;
        struct pmu_event_desc ped;

        event_name = pmu_alias_get(event_name);
        if ((pe = pmu_event_get(NULL, event_name, NULL)) == NULL)
                return (DEFAULT_SAMPLE_COUNT);
        if (pe->event == NULL)
                return (DEFAULT_SAMPLE_COUNT);
        if (pmu_parse_event(&ped, pe->event))
                return (DEFAULT_SAMPLE_COUNT);
        return (ped.ped_period);
}

int
pmc_pmu_enabled(void)
{

        return (pmu_events_map_get(NULL) != NULL);
}

void
pmc_pmu_print_counters(const char *event_name)
{
        const struct pmu_events_map *pme;
        const struct pmu_event *pe;
        struct pmu_event_desc ped;
        char *debug;
        int do_debug;

        debug = getenv("PMUDEBUG");
        do_debug = 0;

        if (debug != NULL && strcmp(debug, "true") == 0)
                do_debug = 1;
        if ((pme = pmu_events_map_get(NULL)) == NULL)
                return;
        for (pe = pme->table; pe->name || pe->desc || pe->event; pe++) {
                if (pe->name == NULL)
                        continue;
                if (event_name != NULL && strcasestr(pe->name, event_name) == NULL)
                        continue;
                printf("\t%s\n", pe->name);
                if (do_debug)
                        pmu_parse_event(&ped, pe->event);
        }
}

void
pmc_pmu_print_counter_desc(const char *ev)
{
        const struct pmu_events_map *pme;
        const struct pmu_event *pe;

        if ((pme = pmu_events_map_get(NULL)) == NULL)
                return;
        for (pe = pme->table; pe->name || pe->desc || pe->event; pe++) {
                if (pe->name == NULL)
                        continue;
                if (strcasestr(pe->name, ev) != NULL &&
                    pe->desc != NULL)
                        printf("%s:\t%s\n", pe->name, pe->desc);
        }
}

void
pmc_pmu_print_counter_desc_long(const char *ev)
{
        const struct pmu_events_map *pme;
        const struct pmu_event *pe;

        if ((pme = pmu_events_map_get(NULL)) == NULL)
                return;
        for (pe = pme->table; pe->name || pe->desc || pe->event; pe++) {
                if (pe->name == NULL)
                        continue;
                if (strcasestr(pe->name, ev) != NULL) {
                        if (pe->long_desc != NULL)
                                printf("%s:\n%s\n", pe->name, pe->long_desc);
                        else if (pe->desc != NULL)
                                printf("%s:\t%s\n", pe->name, pe->desc);
                }
        }
}

void
pmc_pmu_print_counter_full(const char *ev)
{
        const struct pmu_events_map *pme;
        const struct pmu_event *pe;

        if ((pme = pmu_events_map_get(NULL)) == NULL)
                return;
        for (pe = pme->table; pe->name || pe->desc || pe->event; pe++) {
                if (pe->name == NULL)
                        continue;
                if (strcasestr(pe->name, ev) == NULL)
                        continue;
                if (pe != pme->table)
                        printf("\n");
                printf("name: %s\n", pe->name);
                if (pe->long_desc != NULL)
                        printf("desc: %s\n", pe->long_desc);
                else if (pe->desc != NULL)
                        printf("desc: %s\n", pe->desc);
                if (pe->event != NULL)
                        printf("event: %s\n", pe->event);
                if (pe->topic != NULL)
                        printf("topic: %s\n", pe->topic);
                if (pe->pmu != NULL)
                        printf("pmu: %s\n", pe->pmu);
                if (pe->unit != NULL)
                        printf("unit: %s\n", pe->unit);
                if (pe->perpkg != NULL)
                        printf("perpkg: %s\n", pe->perpkg);
                if (pe->metric_expr != NULL)
                        printf("metric_expr: %s\n", pe->metric_expr);
                if (pe->metric_name != NULL)
                        printf("metric_name: %s\n", pe->metric_name);
                if (pe->metric_group != NULL)
                        printf("metric_group: %s\n", pe->metric_group);
        }
}

#if defined(__amd64__) || defined(__i386__)
static int
pmc_pmu_amd_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm,
        struct pmu_event_desc *ped)
{
        int cpu_family;
        struct pmc_md_amd_op_pmcallocate *amd;
        const struct pmu_event *pe;
        int idx = -1;

        cpu_family = pmu_events_x86_family();

        amd = &pm->pm_md.pm_amd;
        if (ped->ped_umask > 0) {
                pm->pm_caps |= PMC_CAP_QUALIFIER;
        }
        pm->pm_class = PMC_CLASS_K8;
        pe = pmu_event_get(NULL, event_name, &idx);

        if (pe->pmu == NULL) {
                amd->pm_amd_config |= AMD_PMC_TO_EVENTMASK(ped->ped_event);
                amd->pm_amd_config |= AMD_PMC_TO_UNITMASK(ped->ped_umask);
                amd->pm_amd_sub_class = PMC_AMD_SUB_CLASS_CORE;
                if ((pm->pm_caps & (PMC_CAP_USER|PMC_CAP_SYSTEM)) == 0 ||
                        (pm->pm_caps & (PMC_CAP_USER|PMC_CAP_SYSTEM)) ==
                        (PMC_CAP_USER|PMC_CAP_SYSTEM))
                        amd->pm_amd_config |= (AMD_PMC_USR | AMD_PMC_OS);
                else if (pm->pm_caps & PMC_CAP_USER)
                        amd->pm_amd_config |= AMD_PMC_USR;
                else if (pm->pm_caps & PMC_CAP_SYSTEM)
                        amd->pm_amd_config |= AMD_PMC_OS;
                if (ped->ped_edge)
                        amd->pm_amd_config |= AMD_PMC_EDGE;
                if (ped->ped_inv)
                        amd->pm_amd_config |= AMD_PMC_INVERT;
                if (pm->pm_caps & PMC_CAP_INTERRUPT)
                        amd->pm_amd_config |= AMD_PMC_INT;
                if (pm->pm_caps & PMC_CAP_PRECISE)
                        amd->pm_amd_config |= AMD_PMC_PRECISERETIRE;
        } else if (strcmp("amd_l3", pe->pmu) == 0) {
                amd->pm_amd_config |= AMD_PMC_L3_TO_EVENTMASK(ped->ped_event);
                amd->pm_amd_config |= AMD_PMC_L3_TO_UNITMASK(ped->ped_umask);
                amd->pm_amd_sub_class = PMC_AMD_SUB_CLASS_L3_CACHE;
                if (cpu_family <= 0x17) {
                        amd->pm_amd_config |=
                            AMD_PMC_L31_TO_SLICE(ped->ped_l3_slice);
                        amd->pm_amd_config |=
                            AMD_PMC_L31_TO_CORE(ped->ped_l3_thread);
                } else {
                        amd->pm_amd_config |=
                            AMD_PMC_L32_TO_THREAD(ped->ped_l3_thread);
                        amd->pm_amd_config |=
                            AMD_PMC_L32_TO_SOURCEID(ped->ped_sourceid);
                        amd->pm_amd_config |=
                            AMD_PMC_L32_TO_COREID(ped->ped_coreid);
                        if (ped->ped_allcores)
                                amd->pm_amd_config |= AMD_PMC_L32_ALLCORES;
                        if (ped->ped_allsources)
                                amd->pm_amd_config |= AMD_PMC_L32_ALLSOURCES;
                }
        } else if (strcmp("amd_df", pe->pmu) == 0) {
                amd->pm_amd_sub_class = PMC_AMD_SUB_CLASS_DATA_FABRIC;
                if (cpu_family <= 19) {
                        amd->pm_amd_config |=
                            AMD_PMC_DF1_TO_EVENTMASK(ped->ped_event);
                        amd->pm_amd_config |=
                            AMD_PMC_DF1_TO_UNITMASK(ped->ped_umask);
                } else {
                        amd->pm_amd_config |=
                            AMD_PMC_DF2_TO_EVENTMASK(ped->ped_event);
                        amd->pm_amd_config |=
                            AMD_PMC_DF2_TO_UNITMASK(ped->ped_umask);
                }
        } else {
                printf("PMC pmu '%s' is not supported!\n", pe->pmu);
                return (EOPNOTSUPP);
        }

        return (0);
}

static int
pmc_pmu_intel_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm,
        struct pmu_event_desc *ped)
{
        struct pmc_md_iap_op_pmcallocate *iap;

        iap = &pm->pm_md.pm_iap;
        if (strcasestr(event_name, "UNC_") == event_name ||
            strcasestr(event_name, "uncore") != NULL) {
                pm->pm_class = PMC_CLASS_UCP;
                pm->pm_caps |= PMC_CAP_QUALIFIER;
                /* XXX Check and block unsupported uncore counters */
        } else if (ped->ped_event == 0x0) {
                pm->pm_class = PMC_CLASS_IAF;
        } else {
                pm->pm_class = PMC_CLASS_IAP;
                pm->pm_caps |= PMC_CAP_QUALIFIER;
        }
        iap->pm_iap_config |= IAP_EVSEL(ped->ped_event);
        if (ped->ped_umask > 0)
                iap->pm_iap_config |= IAP_UMASK(ped->ped_umask);
        iap->pm_iap_config |= IAP_CMASK(ped->ped_cmask);
        iap->pm_iap_rsp = ped->ped_offcore_rsp;

        if ((pm->pm_caps & (PMC_CAP_USER|PMC_CAP_SYSTEM)) == 0 ||
                (pm->pm_caps & (PMC_CAP_USER|PMC_CAP_SYSTEM)) ==
                (PMC_CAP_USER|PMC_CAP_SYSTEM))
                iap->pm_iap_config |= (IAP_USR | IAP_OS);
        else if (pm->pm_caps & PMC_CAP_USER)
                iap->pm_iap_config |= IAP_USR;
        else if (pm->pm_caps & PMC_CAP_SYSTEM)
                iap->pm_iap_config |= IAP_OS;
        if (ped->ped_edge)
                iap->pm_iap_config |= IAP_EDGE;
        if (ped->ped_any)
                iap->pm_iap_config |= IAP_ANY;
        if (ped->ped_inv)
                iap->pm_iap_config |= IAP_INV;
        if (pm->pm_caps & PMC_CAP_INTERRUPT)
                iap->pm_iap_config |= IAP_INT;

        /* XXX Implement alone flag in the kernel module */

        /*
         * PEBS counters are not implemented on FreeBSD yet.  Counters labeled
         * with PEBS = 2 in the JSON definitions require PEBS.  It seems that
         * some of them return bogus counts if you attempt to use them.
         */
        if (ped->ped_pebs == 2) {
                printf("PEBS only counters are not supported!\n");
                return (EOPNOTSUPP);
        }

        return (0);
}

static int
pmc_pmu_pmcallocate_md(const char *event_name, struct pmc_op_pmcallocate *pm)
{
        const struct pmu_event *pe;
        struct pmu_event_desc ped;
        pmu_mfr_t mfr;
        int idx = -1;

        if ((mfr = pmu_events_mfr()) == PMU_INVALID)
                return (ENOENT);

        bzero(&pm->pm_md, sizeof(pm->pm_md));
        pm->pm_caps |= (PMC_CAP_READ | PMC_CAP_WRITE);
        event_name = pmu_alias_get(event_name);
        if ((pe = pmu_event_get(NULL, event_name, &idx)) == NULL)
                return (ENOENT);
        assert(idx >= 0);
        pm->pm_ev = idx;

        if (pe->event == NULL)
                return (ENOENT);
        if (pmu_parse_event(&ped, pe->event))
                return (ENOENT);

        if (mfr == PMU_INTEL)
                return (pmc_pmu_intel_pmcallocate(event_name, pm, &ped));
        else
                return (pmc_pmu_amd_pmcallocate(event_name, pm, &ped));
}

#elif defined(__powerpc64__)

static int
pmc_pmu_pmcallocate_md(const char *event_name, struct pmc_op_pmcallocate *pm)
{
        const struct pmu_event *pe;
        struct pmu_event_desc ped;
        int idx = -1;

        bzero(&pm->pm_md, sizeof(pm->pm_md));
        pm->pm_caps |= (PMC_CAP_READ | PMC_CAP_WRITE);
        event_name = pmu_alias_get(event_name);

        if ((pe = pmu_event_get(NULL, event_name, &idx)) == NULL)
                return (ENOENT);
        if (pe->event == NULL)
                return (ENOENT);
        if (pmu_parse_event(&ped, pe->event))
                return (ENOENT);

        pm->pm_ev = idx;
        pm->pm_md.pm_event = ped.ped_event;
        pm->pm_class = PMC_CLASS_POWER8;
        return (0);
}

#elif defined(__aarch64__)

static int
pmc_pmu_pmcallocate_md(const char *event_name, struct pmc_op_pmcallocate *pm)
{
        const struct pmu_event *pe;
        struct pmu_event_desc ped;
        int idx = -1;

        event_name = pmu_alias_get(event_name);
        if ((pe = pmu_event_get(NULL, event_name, &idx)) == NULL)
                return (ENOENT);
        if (pe->event == NULL)
                return (ENOENT);
        if (pmu_parse_event(&ped, pe->event))
                return (ENOENT);

        assert(idx >= 0);
        pm->pm_ev = idx;
        pm->pm_md.pm_md_config = ped.ped_event;
        pm->pm_class = PMC_CLASS_ARMV8;
        pm->pm_caps |= (PMC_CAP_READ | PMC_CAP_WRITE);

        return (0);
}

#else

static int
pmc_pmu_pmcallocate_md(const char *e __unused, struct pmc_op_pmcallocate *p __unused)
{
        return (EOPNOTSUPP);
}
#endif

int
pmc_pmu_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm)
{
        int error;

        error = pmc_pmu_pmcallocate_md(event_name, pm);
        if (error != 0) {
                /* Reset any changes. */
                pm->pm_ev = 0;
                pm->pm_caps = 0;
                pm->pm_class = 0;

                return (error);
        }

        pm->pm_flags |= PMC_F_EV_PMU;
        return (0);
}