From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12.y 2/2] perf/x86/intel: Remove incorrect LionCove PEBS data-source constraints
Date: Wed, 30 Sep 2026 07:19:34 -0400
Message-ID: <20260930111934.1214295-2-sashal@kernel.org>
In-Reply-To: <20260930111934.1214295-1-sashal@kernel.org>
References: <2026092943-fleshy-frame-920b@gregkh>
 <20260930111934.1214295-1-sashal@kernel.org>
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From: Dapeng Mi <dapeng1.mi@linux.intel.com>

[ Upstream commit 7c944595cc43a664019edc22505b6d6f6039be5e ]

On Lion Cove, PEBS data source is valid only for these events:

- MEM_TRANS_RETIRED.LOAD_LATENCY (0x1cd)
- MEM_TRANS_RETIRED.STORE_SAMPLE (0x2cd)

The perfmon database (https://github.com/intel/perfmon) previously
tagged additional memory events such as MEM_INST_RETIRED.STLB_MISS_LOADS
with L1_Hit_Indication, implying PEBS data-source support, which is
incorrect. The database has since been fixed, but
intel_lnc_pebs_event_constraints[] still follows the old definition and
marks those events as data-source capable.

As a result, get_data_src() may decode data-source information for
events that do not provide valid PEBS data-source data and mislead
users.

Remove those non-data-source memory events from the Lion Cove PEBS
constraint table so matching falls back to the regular non-PEBS
constraints, which already provide the same counter constraints.

Also update lnc_latency_data() to decode LOAD/STORE flags explicitly
when setting memory operation direction, for consistency with other
*_latency_data() helpers.

Fixes: a932aa0e868f ("perf/x86: Add Lunar Lake and Arrow Lake support")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-6-dapeng1.mi@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/events/intel/ds.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 8afe088cb11d1..a3fc38b544245 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -373,7 +373,11 @@ static u64 lnc_latency_data(struct perf_event *event, u64 status)
 		val |= P(BLK, NA);
 
 	src.val = val;
-	if (event->hw.flags & PERF_X86_EVENT_PEBS_ST_HSW)
+	if (event->hw.flags &
+	    (PERF_X86_EVENT_PEBS_LDLAT | PERF_X86_EVENT_PEBS_LD_HSW))
+		src.mem_op = P(OP, LOAD);
+	if (event->hw.flags &
+	    (PERF_X86_EVENT_PEBS_STLAT | PERF_X86_EVENT_PEBS_ST_HSW))
 		src.mem_op = P(OP, STORE);
 
 	return src.val;
@@ -1182,24 +1186,8 @@ struct event_constraint intel_lnc_pebs_event_constraints[] = {
 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x012a, 0x1),		/* OCR.* events */
 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x012b, 0x1),		/* OCR.* events */
 
-	INTEL_FLAGS_UEVENT_CONSTRAINT(0x04a4, 0x1),		/* TOPDOWN.BAD_SPEC_SLOTS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT(0x08a4, 0x1),		/* TOPDOWN.BR_MISPREDICT_SLOTS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT(0x10a4, 0x8),		/* TOPDOWN.MEMORY_BOUND_SLOTS */
-
 	INTEL_HYBRID_LDLAT_CONSTRAINT(0x1cd, 0x3fc),
 	INTEL_HYBRID_STLAT_CONSTRAINT(0x2cd, 0x3),
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x11d0, 0xf),	/* MEM_INST_RETIRED.STLB_MISS_LOADS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x12d0, 0xf),	/* MEM_INST_RETIRED.STLB_MISS_STORES */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x21d0, 0xf),	/* MEM_INST_RETIRED.LOCK_LOADS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x41d0, 0xf),	/* MEM_INST_RETIRED.SPLIT_LOADS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x42d0, 0xf),	/* MEM_INST_RETIRED.SPLIT_STORES */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x81d0, 0xf),	/* MEM_INST_RETIRED.ALL_LOADS */
-	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x82d0, 0xf),	/* MEM_INST_RETIRED.ALL_STORES */
-	INTEL_FLAGS_UEVENT_CONSTRAINT(0x87d0, 0x3ff),		/* MEM_INST_RETIRED.ANY */
-
-	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD_RANGE(0xd1, 0xd4, 0xf),
-
-	INTEL_FLAGS_EVENT_CONSTRAINT(0xd0, 0xf),
 
 	/*
 	 * Everything else is handled by PMU_FL_PEBS_ALL, because we
-- 
2.53.0