git: f0b8806a73fd - stable/15 - libpmc: Fix the L3 counters for AMD Zen 1-4

The branch stable/15 has been updated by mhorne:

URL: https://cgit.FreeBSD.org/src/commit/?id=f0b8806a73fddef14757469dfb383130c636897f

commit f0b8806a73fddef14757469dfb383130c636897f
Author:     Ali Mashtizadeh <ali@mashtizadeh.com>
AuthorDate: 2026-01-23 05:34:13 +0000
Commit:     Mitchell Horne <mhorne@FreeBSD.org>
CommitDate: 2026-04-16 15:10:59 +0000

    libpmc: Fix the L3 counters for AMD Zen 1-4
    
    On AMD processors libpmc was using the topic field (based on filename) to
    determine the counter's subclass.  Unfortunately, the JSON definitions for
    AMD Zen 1-4 have the L3 counters in files shared with other counters.
    
    This change has libpmc to use the pmu field (which is derived from the Unit
    field in JSON) to determine the correct counter subclass.
    
    Reviewed by:    mhorne
    MFC after:      2 weeks
    Sponsored by:   Netflix
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1984
    
    (cherry picked from commit c215eef345501ce7dda374909b3195d9d69a4e9f)
---
 lib/libpmc/libpmc_pmu_util.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/lib/libpmc/libpmc_pmu_util.c b/lib/libpmc/libpmc_pmu_util.c
index 74a93ae963d7..de642aa71a18 100644
--- a/lib/libpmc/libpmc_pmu_util.c
+++ b/lib/libpmc/libpmc_pmu_util.c
@@ -498,18 +498,7 @@ pmc_pmu_amd_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm,
 	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{
+	if (pe->pmu == NULL) {
 		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 ||
@@ -526,7 +515,19 @@ pmc_pmu_amd_pmcallocate(const char *event_name, struct pmc_op_pmcallocate *pm,
 			amd->pm_amd_config |= AMD_PMC_INVERT;
 		if (pm->pm_caps & PMC_CAP_INTERRUPT)
 			amd->pm_amd_config |= AMD_PMC_INT;
+	} else if (strcmp("amd_l3", pe->pmu) == 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("amd_df", pe->pmu) == 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 {
+		printf("PMC pmu '%s' is not supported!\n", pe->pmu);
+		return (EOPNOTSUPP);
 	}
+
 	return (0);
 }