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Commit ba90c516 authored by Dave Martin's avatar Dave Martin Committed by Russell King
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ARM: 7197/1: errata: Remove SMP dependency for erratum 751472 



Activation conditions for a workaround should not be encoded in the
workaround's direct dependencies if this makes otherwise reasonable
configuration choices impossible.

This patches uses the SMP/UP patching facilities instead to compile
out the workaround if the configuration means that it is definitely
not needed.

This means that configs for buggy silicon can simply select
ARM_ERRATA_751472, without preventing a UP kernel from being built
or duplicatiing knowledge about when to activate the workaround.
This seems the correct way to do things, because the erratum is a
property of the silicon, irrespective of what the kernel config
happens to be.

Signed-off-by: default avatarDave Martin <dave.martin@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent e66dc745

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -1282,7 +1282,7 @@ config ARM_ERRATA_743622 


config ARM_ERRATA_751472

	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"

	depends on CPU_V7 && SMP

	depends on CPU_V7

	help

	  This option enables the workaround for the 751472 Cortex-A9 (prior

	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the

arch/arm/mm/proc-v7.S

+4 −2
Original line number Diff line number Diff line
@@ -363,11 +363,13 @@ __v7_setup: 
	orreq	r10, r10, #1 << 6		@ set bit #6

	mcreq	p15, 0, r10, c15, c0, 1		@ write diagnostic register

#endif

#ifdef CONFIG_ARM_ERRATA_751472

	cmp	r6, #0x30			@ present prior to r3p0

#if defined(CONFIG_ARM_ERRATA_751472) && defined(CONFIG_SMP)

	ALT_SMP(cmp r6, #0x30)			@ present prior to r3p0

	ALT_UP_B(1f)

	mrclt	p15, 0, r10, c15, c0, 1		@ read diagnostic register

	orrlt	r10, r10, #1 << 11		@ set bit #11

	mcrlt	p15, 0, r10, c15, c0, 1		@ write diagnostic register

1:

#endif



3:	mov	r10, #0