[PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr

Kajol Jain kjain at linux.ibm.com
Thu Aug 19 03:15:54 AEST 2021


Minor optimization in the 'perf_instruction_pointer' function code by
making use of stack siar instead of mfspr.

Fixes: 75382aa72f06 ("powerpc/perf: Move code to select SIAR or pt_regs
into perf_read_regs")
Signed-off-by: Kajol Jain <kjain at linux.ibm.com>
---
 arch/powerpc/perf/core-book3s.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index bb0ee716de91..1b464aad29c4 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2260,7 +2260,7 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
 		else
 			return regs->nip;
 	} else if (use_siar && siar_valid(regs))
-		return mfspr(SPRN_SIAR) + perf_ip_adjust(regs);
+		return siar + perf_ip_adjust(regs);
 	else if (use_siar)
 		return 0;		// no valid instruction pointer
 	else
-- 
2.26.2



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