Commit 1a6bfbc3 authored Apr 14, 2014 by Gregory CLEMENT Committed by Jason Cooper May 08, 2014

ARM: mvebu: Low level function to disable HW coherency support

When going to deep idle we need to disable the SoC snooping (aka
hardware coherency support). Playing with the coherency fabric
requires to use assembly code to be sure that the compiler doesn't
reorder the instructions nor do wrong optimization.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-7-git-send-email-gregory.clement@free-electrons.com

Signed-off-by: Jason Cooper <jason@lakedaemon.net>

parent 2e8a5942

arch/arm/mach-mvebu/coherency_ll.S

+20 −0

Original line number	Original line	Diff line number	Diff line
	@@ -102,6 +102,26 @@ ENTRY(ll_enable_coherency)
	mov pc, lr		mov pc, lr
	ENDPROC(ll_enable_coherency)		ENDPROC(ll_enable_coherency)

			ENTRY(ll_disable_coherency)
			/*
			* r0 being untouched in ll_get_coherency_base and
			* ll_get_cpuid, we can use it to save lr modifing it with the
			* following bl
			*/
			mov r0, lr
			bl ll_get_coherency_base
			bl ll_get_cpuid
			mov lr, r0
			add r0, r1, #ARMADA_XP_CFB_CTL_REG_OFFSET
			1:
			ldrex r2, [r0]
			bic r2, r2, r3
			strex r1, r2, [r0]
			cmp r1, #0
			bne 1b
			dsb
			mov pc, lr
			ENDPROC(ll_disable_coherency)

	.align 2		.align 2
	3:		3: