[PATCH review for 4.9 44/50] powerpc/perf: Add restrictions to PMC5 in power9 DD1

From: Levin, Alexander (Sasha Levin)
Date: Sun Sep 24 2017 - 21:15:17 EST


From: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 8d911904f3ce412b20874a9c95f82009dcbb007c ]

PMC5 on POWER9 DD1 may not provide right counts in all
sampling scenarios, hence use PM_INST_DISP event instead
in PMC2 or PMC3 in preference.

Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
arch/powerpc/perf/isa207-common.h | 4 ++++
arch/powerpc/perf/power9-pmu.c | 2 +-
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
index 4d0a4e5017c2..8e6dd17fe603 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -201,6 +201,10 @@
CNST_PMC_VAL(1) | CNST_PMC_VAL(2) | CNST_PMC_VAL(3) | \
CNST_PMC_VAL(4) | CNST_PMC_VAL(5) | CNST_PMC_VAL(6) | CNST_NC_VAL

+/*
+ * Lets restrict use of PMC5 for instruction counting.
+ */
+#define P9_DD1_TEST_ADDER (ISA207_TEST_ADDER | CNST_PMC_VAL(5))

/* Bits in MMCR1 for PowerISA v2.07 */
#define MMCR1_UNIT_SHIFT(pmc) (60 - (4 * ((pmc) - 1)))
diff --git a/arch/powerpc/perf/power9-pmu.c b/arch/powerpc/perf/power9-pmu.c
index 8e9a81967ff8..9abcd8f65504 100644
--- a/arch/powerpc/perf/power9-pmu.c
+++ b/arch/powerpc/perf/power9-pmu.c
@@ -295,7 +295,7 @@ static struct power_pmu power9_pmu = {
.name = "POWER9",
.n_counter = MAX_PMU_COUNTERS,
.add_fields = ISA207_ADD_FIELDS,
- .test_adder = ISA207_TEST_ADDER,
+ .test_adder = P9_DD1_TEST_ADDER,
.compute_mmcr = isa207_compute_mmcr,
.config_bhrb = power9_config_bhrb,
.bhrb_filter_map = power9_bhrb_filter_map,
--
2.11.0