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Commit bd19c899 authored Jun 11, 2006 by Anton Blanchard Committed by Paul Mackerras Jun 15, 2006

[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>

parent 9e6e3c2c

arch/powerpc/kernel/entry_64.S

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -57,6 +57,7 @@ system_call_common:
	beq- 1f		beq- 1f
	ld r1,PACAKSAVE(r13)		ld r1,PACAKSAVE(r13)
	1: std r10,0(r1)		1: std r10,0(r1)
			crclr so
	std r11,_NIP(r1)		std r11,_NIP(r1)
	std r12,_MSR(r1)		std r12,_MSR(r1)
	std r0,GPR0(r1)		std r0,GPR0(r1)
	@@ -75,7 +76,6 @@ system_call_common:
	std r11,GPR11(r1)		std r11,GPR11(r1)
	std r11,GPR12(r1)		std r11,GPR12(r1)
	std r9,GPR13(r1)		std r9,GPR13(r1)
	crclr so
	mfcr r9		mfcr r9
	mflr r10		mflr r10
	li r11,0xc01		li r11,0xc01