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Commit a2eddc7c authored by David Howells's avatar David Howells Committed by Al Viro
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FRV: Optimise the system call exit path in entry.S [ver #2] 



Optimise the system call exit path in entry.S by packing some instructions.

Suggested-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 1e5ef915

arch/frv/kernel/entry.S

+7 −6
Original line number Original line Diff line number Diff line
@@ -905,18 +905,19 @@ __syscall_call: 
__syscall_exit:

__syscall_exit:

	LEDS		0x6300

	LEDS		0x6300





	sti		gr8,@(gr28,#REG_GR(8))	; save return value

	# keep current PSR in GR23

	movsg		psr,gr23





	# rebuild saved psr - execve will change it for init/main.c

	ldi		@(gr28,#REG_PSR),gr22

	ldi		@(gr28,#REG_PSR),gr22



	sti.p		gr8,@(gr28,#REG_GR(8))	; save return value



	# rebuild saved psr - execve will change it for init/main.c

	srli		gr22,#1,gr5

	srli		gr22,#1,gr5

	andi.p		gr22,#~PSR_PS,gr22

	andi.p		gr22,#~PSR_PS,gr22

	andi		gr5,#PSR_PS,gr5

	andi		gr5,#PSR_PS,gr5

	or		gr5,gr22,gr22

	or		gr5,gr22,gr22

	ori		gr22,#PSR_S,gr22

	ori.p		gr22,#PSR_S,gr22



	# keep current PSR in GR23

	movsg		psr,gr23





	# make sure we don't miss an interrupt setting need_resched or sigpending between

	# make sure we don't miss an interrupt setting need_resched or sigpending between

	# sampling and the RETT

	# sampling and the RETT