Subject: [PATCH v2 2/5] powerpc/perf: Drop the check for SIAR_VALID

From: Madhavan Srinivasan <[email-masked]>
Date: Wed, 21 Oct 2020 14:23:26 +0530

From: Athira Rajeev <[email-masked]>

In power10 DD1, there is an issue that causes the SIAR_VALID
bit of Sampled Instruction Event Register(SIER) not to be
set. But the SIAR_VALID bit is used for fetching the instruction
address from Sampled Instruction Address Register(SIAR), 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 <[email-masked]>
Signed-off-by: Madhavan Srinivasan <[email-masked]>
---
Changelog v1:
- Drop the check for SIER[CMPL] and retur true instead
- Made changes to commit message

 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