From fdf13a657508a12cd21a4d7b988cb260cb8fbd38 Mon Sep 17 00:00:00 2001
From: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Date: Wed, 21 Oct 2020 14:23:26 +0530
Subject: [PATCH] powerpc/perf: Drop the check for SIAR_VALID
References: jsc#SLE-13513 bsc#1176919 ltc#186162
Patch-mainline: v5.11-rc1
Git-commit: fdf13a657508a12cd21a4d7b988cb260cb8fbd38
In power10 DD1, there is an issue that causes the SIAR_VALID bit of
the SIER (Sampled Instruction Event Register) to not be set. But the
SIAR_VALID bit is used for fetching the instruction address from the
SIAR (Sampled Instruction Address Register), and marked events are
sampled only if the SIAR_VALID bit is set. So drop the check for
SIAR_VALID and return true always incase of power10 DD1.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021085329.384535-2-maddy@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/perf/core-book3s.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 08643cba1494..3b62dbb94796 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -350,7 +350,14 @@ static inline int siar_valid(struct pt_regs *regs)
int marked = mmcra & MMCRA_SAMPLE_ENABLE;
if (marked) {
- if (ppmu->flags & PPMU_HAS_SIER)
+ /*
+ * SIER[SIAR_VALID] is not set for some
+ * marked events on power10 DD1, so drop
+ * the check for SIER[SIAR_VALID] and return true.
+ */
+ if (ppmu->flags & PPMU_P10_DD1)
+ return 0x1;
+ else if (ppmu->flags & PPMU_HAS_SIER)
return regs->dar & SIER_SIAR_VALID;
if (ppmu->flags & PPMU_SIAR_VALID)
--
2.26.2