ARM: 6388/1: errata: DMB operation may be faulty
On versions of the Cortex-A9 up to and including r2p2, under rare
circumstances, a DMB instruction between 2 write operations may not
ensure the correct visibility ordering of the 2 writes.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
causing the DMB instruction to behave like a DSB, which functions
correctly on the affected cores.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 553b7cf..ab14c0a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1051,6 +1051,18 @@
ACTLR register. Note that setting specific bits in the ACTLR register
may not be available in non-secure mode.
+config ARM_ERRATA_742230
+ bool "ARM errata: DMB operation may be faulty"
+ depends on CPU_V7 && SMP
+ help
+ This option enables the workaround for the 742230 Cortex-A9
+ (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
+ between two write operations may not ensure the correct visibility
+ ordering of the two writes. This workaround sets a specific bit in
+ the diagnostic register of the Cortex-A9 which causes the DMB
+ instruction to behave as a DSB, ensuring the correct behaviour of
+ the two writes.
+
config PL310_ERRATA_588369
bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
depends on CACHE_L2X0 && ARCH_OMAP4