linux-kernel - [PATCH] perf/x86/core: Set pebs_capable and PMU_FL_PEBS

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Date:   Tue, 16 Aug 2022 19:40:57 +0800
From:   Like Xu <like.xu.linux@...il.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Kan Liang <kan.liang@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>, x86@...nel.org,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] perf/x86/core: Set pebs_capable and PMU_FL_PEBS_ALL for the Baseline

From: Peter Zijlstra <peterz@...radead.org>

The SDM explicitly states that PEBS Baseline implies Extended PEBS.
For cpu model forward compatibility (e.g. on ICX, SPR, ADL), it's
safe to stop doing FMS table thing such as setting pebs_capable and
PMU_FL_PEBS_ALL since it's already set in the intel_ds_init().

The Goldmont Plus is the only platform which supports extended PEBS
but doesn't have Baseline. Keep the status quo.

Cc: Kan Liang <kan.liang@...ux.intel.com>
Reported-by: Like Xu <likexu@...cent.com>
Signed-off-by: Peter Zijlstra <peterz@...radead.org>
---
 arch/x86/events/intel/core.c | 4 ----
 arch/x86/events/intel/ds.c   | 1 +
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 2db93498ff71..cb98a05ee743 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -6291,10 +6291,8 @@ __init int intel_pmu_init(void)
 		x86_pmu.pebs_aliases = NULL;
 		x86_pmu.pebs_prec_dist = true;
 		x86_pmu.pebs_block = true;
-		x86_pmu.pebs_capable = ~0ULL;
 		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
 		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
-		x86_pmu.flags |= PMU_FL_PEBS_ALL;
 		x86_pmu.flags |= PMU_FL_INSTR_LATENCY;
 		x86_pmu.flags |= PMU_FL_MEM_LOADS_AUX;
 
@@ -6337,10 +6335,8 @@ __init int intel_pmu_init(void)
 		x86_pmu.pebs_aliases = NULL;
 		x86_pmu.pebs_prec_dist = true;
 		x86_pmu.pebs_block = true;
-		x86_pmu.pebs_capable = ~0ULL;
 		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
 		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
-		x86_pmu.flags |= PMU_FL_PEBS_ALL;
 		x86_pmu.flags |= PMU_FL_INSTR_LATENCY;
 		x86_pmu.flags |= PMU_FL_MEM_LOADS_AUX;
 		x86_pmu.lbr_pt_coexist = true;
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index ba60427caa6d..ac6dd4c96dbc 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2262,6 +2262,7 @@ void __init intel_ds_init(void)
 					PERF_SAMPLE_BRANCH_STACK |
 					PERF_SAMPLE_TIME;
 				x86_pmu.flags |= PMU_FL_PEBS_ALL;
+				x86_pmu.pebs_capable = ~0ULL;
 				pebs_qual = "-baseline";
 				x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_EXTENDED_REGS;
 			} else {
-- 
2.37.2