From bd19c8994a828e70b5472f0ce9df5831c6c3db84 Mon Sep 17 00:00:00 2001
From: Anton Blanchard <anton@samba.org>
Date: Sun, 11 Jun 2006 01:15:55 +1000
Subject: [PATCH] [POWERPC] system call micro optimisation
In the syscall path we currently have:
crclr so
mfcr r9
If we shift the crclr up we can avoid a stall on some CPUs.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/kernel/entry_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 19ad5c6b18185..221062c960c99 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -57,6 +57,7 @@ system_call_common:
beq- 1f
ld r1,PACAKSAVE(r13)
1: std r10,0(r1)
+ crclr so
std r11,_NIP(r1)
std r12,_MSR(r1)
std r0,GPR0(r1)
@@ -75,7 +76,6 @@ system_call_common:
std r11,GPR11(r1)
std r11,GPR12(r1)
std r9,GPR13(r1)
- crclr so
mfcr r9
mflr r10
li r11,0xc01
--
2.30.2