[tip: perf/urgent] perf/x86/intel: Fix OMR snoop information parsing issues

[tip-bot2 for Dapeng Mi]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     e7fcc54524f04e42641de99028edd9c69dc19f8c
Gitweb:        https://git.kernel.org/tip/e7fcc54524f04e42641de99028edd9c69dc19f8c
Author:        Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
AuthorDate:    Wed, 11 Mar 2026 15:52:00 +08:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 12 Mar 2026 11:29:16 +01:00

perf/x86/intel: Fix OMR snoop information parsing issues

When omr_source is 0x2, the omr_snoop (bit[6]) and omr_promoted (bit[7])
fields are combined to represent the snoop information. However, the
omr_promoted field was not left-shifted by 1 bit, resulting in incorrect
snoop information.

Besides, the snoop information parsing is not accurate for some OMR
sources, like the snoop information should be SNOOP_NONE for these memory
access (omr_source >= 7) instead of SNOOP_HIT.

Fix these issues.

Closes: https://lore.kernel.org/all/CAP-5=fW4zLWFw1v38zCzB9-cseNSTTCtup=p2SDxZq7dPayVww@xxxxxxxxxxxxxx/
Fixes: d2bdcde9626c ("perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR")
Reported-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Link: https://patch.msgid.link/20260311075201.2951073-1-dapeng1.mi@xxxxxxxxxxxxxxx
---
 arch/x86/events/intel/ds.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 5027afc..7f0d515 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -345,12 +345,12 @@ static u64 parse_omr_data_source(u8 dse)
 	if (omr.omr_remote)
 		val |= REM;
 
-	val |= omr.omr_hitm ? P(SNOOP, HITM) : P(SNOOP, HIT);
-
 	if (omr.omr_source == 0x2) {
-		u8 snoop = omr.omr_snoop | omr.omr_promoted;
+		u8 snoop = omr.omr_snoop | (omr.omr_promoted << 1);
 
-		if (snoop == 0x0)
+		if (omr.omr_hitm)
+			val |= P(SNOOP, HITM);
+		else if (snoop == 0x0)
 			val |= P(SNOOP, NA);
 		else if (snoop == 0x1)
 			val |= P(SNOOP, MISS);
@@ -359,7 +359,10 @@ static u64 parse_omr_data_source(u8 dse)
 		else if (snoop == 0x3)
 			val |= P(SNOOP, NONE);
 	} else if (omr.omr_source > 0x2 && omr.omr_source < 0x7) {
+		val |= omr.omr_hitm ? P(SNOOP, HITM) : P(SNOOP, HIT);
 		val |= omr.omr_snoop ? P(SNOOPX, FWD) : 0;
+	} else {
+		val |= P(SNOOP, NONE);
 	}
 
 	return val;