freebsd-src/lib/libpmc/libpmc_pmu_util.c

/*-
 * 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);
}

/*
 *  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_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;
};

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 {
			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;
		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)
{
	struct pmc_md_amd_op_pmcallocate *amd;
	const struct pmu_event *pe;
	int idx = -1;

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

	if (strcmp("l3cache", pe->topic) == 0){
		amd->pm_amd_config |= AMD_PMC_TO_EVENTMASK(ped->ped_event);
		amd->pm_amd_sub_class = PMC_AMD_SUB_CLASS_L3_CACHE;
		amd->pm_amd_config |= AMD_PMC_TO_L3SLICE(ped->ped_l3_slice);
		amd->pm_amd_config |= AMD_PMC_TO_L3CORE(ped->ped_l3_thread);
	}
	else if (strcmp("data fabric", pe->topic) == 0){

		amd->pm_amd_config |= AMD_PMC_TO_EVENTMASK_DF(ped->ped_event);
		amd->pm_amd_sub_class = PMC_AMD_SUB_CLASS_DATA_FABRIC;
	}
	else{
		amd->pm_amd_config |= AMD_PMC_TO_EVENTMASK(ped->ped_event);
		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;
	}
	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;
	} 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;
	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);
}