[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>
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 19ad5c6..221062c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -57,6 +57,7 @@
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 @@
std r11,GPR11(r1)
std r11,GPR12(r1)
std r9,GPR13(r1)
- crclr so
mfcr r9
mflr r10
li r11,0xc01