linux-kernel - [PATCH 4.19 225/271] perf/x86/amd/uncore: Do not set ThreadMask and SliceMask for non-L3 PMCs

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Message-Id: <20190724191714.427597299@linuxfoundation.org>
Date:   Wed, 24 Jul 2019 21:21:34 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Kim Phillips <kim.phillips@....com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Borislav Petkov <bp@...en8.de>, Gary Hook <Gary.Hook@....com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Janakarajan Natarajan <Janakarajan.Natarajan@....com>,
        Jiri Olsa <jolsa@...hat.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Martin Liska <mliska@...e.cz>,
        Namhyung Kim <namhyung@...nel.org>, Pu Wen <puwen@...on.cn>,
        Stephane Eranian <eranian@...gle.com>,
        Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vince Weaver <vincent.weaver@...ne.edu>,
        Ingo Molnar <mingo@...nel.org>
Subject: [PATCH 4.19 225/271] perf/x86/amd/uncore: Do not set ThreadMask and SliceMask for non-L3 PMCs

From: Kim Phillips <kim.phillips@....com>

commit 16f4641166b10e199f0d7b68c2c5f004fef0bda3 upstream.

The following commit:

  d7cbbe49a930 ("perf/x86/amd/uncore: Set ThreadMask and SliceMask for L3 Cache perf events")

enables L3 PMC events for all threads and slices by writing 1's in
'ChL3PmcCfg' (L3 PMC PERF_CTL) register fields.

Those bitfields overlap with high order event select bits in the Data
Fabric PMC control register, however.

So when a user requests raw Data Fabric events (-e amd_df/event=0xYYY/),
the two highest order bits get inadvertently set, changing the counter
select to events that don't exist, and for which no counts are read.

This patch changes the logic to write the L3 masks only when dealing
with L3 PMC counters.

AMD Family 16h and below Northbridge (NB) counters were not affected.

Signed-off-by: Kim Phillips <kim.phillips@....com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: <stable@...r.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Gary Hook <Gary.Hook@....com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@....com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Martin Liska <mliska@...e.cz>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Pu Wen <puwen@...on.cn>
Cc: Stephane Eranian <eranian@...gle.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Vince Weaver <vincent.weaver@...ne.edu>
Fixes: d7cbbe49a930 ("perf/x86/amd/uncore: Set ThreadMask and SliceMask for L3 Cache perf events")
Link: https://lkml.kernel.org/r/20190628215906.4276-1-kim.phillips@amd.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/x86/events/amd/uncore.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -214,7 +214,7 @@ static int amd_uncore_event_init(struct
 	 * SliceMask and ThreadMask need to be set for certain L3 events in
 	 * Family 17h. For other events, the two fields do not affect the count.
 	 */
-	if (l3_mask)
+	if (l3_mask && is_llc_event(event))
 		hwc->config |= (AMD64_L3_SLICE_MASK | AMD64_L3_THREAD_MASK);

 	if (event->cpu < 0)