libpmc: eliminate pmc_pmu_stat_mode()

There is a single consumer, the pmc utility, that clearly has knowledge
of which counters it is expecting. Remove this function and have it
use common counter aliases instead.

Reviewed by:	gnn
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D30528

(cherry picked from commit ec66cc955b629e614cf493bf168048de033f6a2c)

3 files changed, 11 insertions, 27 deletions

diff --git a/lib/libpmc/libpmc_pmu_util.c b/lib/libpmc/libpmc_pmu_util.c
index 6a287a66a2f8..90ce0feafa52 100644
--- a/lib/libpmc/libpmc_pmu_util.c
+++ b/lib/libpmc/libpmc_pmu_util.c
@@ -538,28 +538,6 @@ pmc_pmu_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm)
 		return (pmc_pmu_amd_pmcallocate(event_name, pm, &ped));
 }
 
-/*
- * Ultimately rely on AMD calling theirs the same
- */
-static const char *stat_mode_cntrs[] = {
-	"cpu_clk_unhalted.thread",
-	"inst_retired.any",
-	"br_inst_retired.all_branches",
-	"br_misp_retired.all_branches",
-	"longest_lat_cache.reference",
-	"longest_lat_cache.miss",
-};
-
-int
-pmc_pmu_stat_mode(const char ***cntrs)
-{
-	if (pmc_pmu_enabled()) {
-		*cntrs = stat_mode_cntrs;
-		return (0);
-	}
-	return (EOPNOTSUPP);
-}
-
 #else
 
 uint64_t
diff --git a/lib/libpmc/pmc.h b/lib/libpmc/pmc.h
index 9d12085364e5..7579f93a42b1 100644
--- a/lib/libpmc/pmc.h
+++ b/lib/libpmc/pmc.h
@@ -122,7 +122,6 @@ uint64_t pmc_pmu_sample_rate_get(const char *);
 int pmc_pmu_pmcallocate(const char *, struct pmc_op_pmcallocate *);
 const char *pmc_pmu_event_get_by_idx(const char *, int idx);
 int pmc_pmu_idx_get_by_event(const char*, const char *);
-int pmc_pmu_stat_mode(const char ***);
 __END_DECLS
 
 #endif
diff --git a/usr.sbin/pmc/cmd_pmc_stat.c b/usr.sbin/pmc/cmd_pmc_stat.c
index 44ca7b92dea7..55d1f1ca7a3b 100644
--- a/usr.sbin/pmc/cmd_pmc_stat.c
+++ b/usr.sbin/pmc/cmd_pmc_stat.c
@@ -104,6 +104,16 @@ static const char *pmc_stat_mode_names[] = {
 	"cache-misses",
 };
 
+/* Common aliases for the desired stat counter */
+static const char *pmc_stat_mode_aliases[] = {
+	"unhalted-cycles",
+	"instructions",
+	"branches",
+	"branch-mispredicts",
+	"LLC-REFERENCE",
+	"LLC-MISSES",
+};
+
 static int pmcstat_sockpair[NSOCKPAIRFD];
 
 static void __dead2
@@ -153,7 +163,6 @@ static void
 pmc_stat_setup_stat(int system_mode, const char *arg)
 {
 	const char *new_cntrs[STAT_MODE_NPMCS];
-	static const char **pmc_stat_mode_cntrs;
 	struct pmcstat_ev *ev;
 	char *counters, *counter;
 	int i, c, start, newcnt;
@@ -164,13 +173,11 @@ pmc_stat_setup_stat(int system_mode, const char *arg)
 		err(EX_OSERR, "ERROR: Cannot determine the root set of CPUs");
 	CPU_COPY(&rootmask, &cpumask);
 
-	if (pmc_pmu_stat_mode(&pmc_stat_mode_cntrs) != 0)
-		errx(EX_USAGE, "ERROR: hwmpc.ko not loaded or stat not supported on host.");
 	if (system_mode && geteuid() != 0)
 		errx(EX_USAGE, "ERROR: system mode counters can only be used as root");
 	counters = NULL;
 	for (i = 0; i < STAT_MODE_NPMCS; i++) {
-		stat_mode_cntrs[i] = pmc_stat_mode_cntrs[i];
+		stat_mode_cntrs[i] = pmc_stat_mode_aliases[i];
 		stat_mode_names[i] = pmc_stat_mode_names[i];
 	}
 	if (arg) {