[PATCH] powerpc/perf: fix Threshold Event CounterMultiplier width for P10

Madhavan Srinivasan maddy at linux.ibm.com
Mon Oct 12 21:31:28 AEDT 2020


Power9 and isa v3.1 has 7bit mantissa field for Threshold Event Counter
Multiplier (TECM). TECM is part of Monitor Mode Control Register A (MMCRA).
This field along with Threshold Event Counter Exponent (TECE) is used to
get threshould counter value. In Power10, the width of TECM field is
increase to 8bits. Patch fixes the current code to modify the MMCRA[TECM]
extraction macro to handling this changes.

Fixes: 170a315f41c64 ('powerpc/perf: Support to export MMCRA[TEC*] field to userspace')
Signed-off-by: Madhavan Srinivasan <maddy at linux.ibm.com>
---
 arch/powerpc/perf/isa207-common.c | 3 +++
 arch/powerpc/perf/isa207-common.h | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index 964437adec18..5fe129f02290 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -247,6 +247,9 @@ void isa207_get_mem_weight(u64 *weight)
 	u64 sier = mfspr(SPRN_SIER);
 	u64 val = (sier & ISA207_SIER_TYPE_MASK) >> ISA207_SIER_TYPE_SHIFT;
 
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		mantissa = P10_MMCRA_THR_CTR_MANT(mmcra);
+
 	if (val == 0 || val == 7)
 		*weight = 0;
 	else
diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
index 044de65e96b9..71380e854f48 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -219,6 +219,10 @@
 #define MMCRA_THR_CTR_EXP(v)		(((v) >> MMCRA_THR_CTR_EXP_SHIFT) &\
 						MMCRA_THR_CTR_EXP_MASK)
 
+#define P10_MMCRA_THR_CTR_MANT_MASK	0xFFul
+#define P10_MMCRA_THR_CTR_MANT(v)	(((v) >> MMCRA_THR_CTR_MANT_SHIFT) &\
+						P10_MMCRA_THR_CTR_MANT_MASK)
+
 /* MMCRA Threshold Compare bit constant for power9 */
 #define p9_MMCRA_THR_CMP_SHIFT	45
 
-- 
2.26.2



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