From: Kajol Jain <kjain@linux.ibm.com>
Date: Wed, 18 Aug 2021 17:15:54 +0000 (+0530)
Subject: powerpc/perf: Use stack siar instead of mfspr
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b1643084d164cea0c107a39bcdf0119fc52619af;p=linux.git

powerpc/perf: Use stack siar instead of mfspr

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@linux.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210818171556.36912-1-kjain@linux.ibm.com
---

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 91203ed9d0ff9..3a782a35100dc 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2269,7 +2269,7 @@ 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