Commit 82087414 authored Apr 04, 2012 by Anton Blanchard Committed by Benjamin Herrenschmidt Apr 30, 2012

powerpc: No need to preserve count register across system call



The count register is volatile so we don't need to preserve it.
Store zero to the entry in the exception frame.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

parent 823df435

arch/powerpc/kernel/entry_64.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -83,6 +83,7 @@ system_call_common:
		std r11,GPR11(r1)
		std r11,GPR12(r1)
		std r11,_XER(r1)
		std r11,_CTR(r1)
		std r9,GPR13(r1)
		mfcr r9
		mflr r10
		@@ -90,8 +91,6 @@ system_call_common:
		std r9,_CCR(r1)
		std r10,_LINK(r1)
		std r11,_TRAP(r1)
		mfctr r10
		std r10,_CTR(r1)
		std r3,ORIG_GPR3(r1)
		ld r2,PACATOC(r13)
		addi r9,r1,STACK_FRAME_OVERHEAD