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Commit 43f6cdd7 authored by Jesper Nilsson's avatar Jesper Nilsson
Browse files

CRIS: Simple insn reschedule to avoid interlocks. 



Brings down the CPI from ~1.5 to ~1.1.

Signed-off-by: default avatarEdgar Iglesias <Edgar.Iglesias@axis.com>
Signed-off-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
parent a80a635f

arch/cris/arch-v32/kernel/entry.S

+9 −9
Original line number Diff line number Diff line
@@ -348,40 +348,40 @@ _syscall_trace_entry: 


	.type	resume,@function

resume:

	subq	4, $sp

	move	$srp, [$sp]		; Keep old/new PC on the stack.

	subq	4, $sp			; Make space for srp.



	add.d	$r12, $r10		; R10 = current tasks tss.

	addoq	+THREAD_ccs, $r10, $acr

	move	$srp, [$sp]		; Keep old/new PC on the stack.

	move	$ccs, [$acr]		; Save IRQ enable state.

	di



	addoq	+THREAD_usp, $r10, $acr

	subq	10*4, $sp		; Make room for R9.

	move	$usp, [$acr]		; Save user-mode stackpointer.



	;; See copy_thread for the reason why register R9 is saved.

	subq	10*4, $sp

	movem	$r9, [$sp]		; Save non-scratch registers and R9.



	addoq	+THREAD_ksp, $r10, $acr

	move.d	$sp, $r10		; Return last running task in R10.

	move.d	$sp, [$acr]		; Save kernel SP for old task.



	move.d	$sp, $r10		; Return last running task in R10.

	and.d   -8192, $r10		; Get thread_info from stackpointer.

	addoq	+TI_task, $r10, $acr

	move.d	[$acr], $r10		; Get task.

	add.d	$r12, $r11		; Find the new tasks tss.

	move.d	[$acr], $r10		; Get task.

	addoq	+THREAD_ksp, $r11, $acr

	move.d	[$acr], $sp		; Switch to new stackframe.

	addoq	+THREAD_usp, $r11, $acr

	movem	[$sp+], $r9		; Restore non-scratch registers and R9.



	addoq	+THREAD_usp, $r11, $acr

	move	[$acr], $usp		; Restore user-mode stackpointer.



	addoq	+THREAD_ccs, $r11, $acr

	move.d	[$sp+], $r11

	jump	$r11			; Restore PC.

	move	[$acr], $ccs		; Restore IRQ enable status.

	move.d	[$sp+], $acr

	jump	$acr			; Restore PC.

	nop

	.size	resume, . - resume



nmi_interrupt: