[ARM] 5490/1: ARM errata: Processor deadlock when a false hazard is created

This patch adds a workaround for the 458693 Cortex-A8 (r2p0)
erratum. It sets the corresponding bits in the auxiliary control
register so that the PLD instruction becomes a NOP.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 84e4816..49f8566 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -765,6 +765,19 @@
 	  Note that setting specific bits in the ACTLR register may not be
 	  available in non-secure mode.
 
+config ARM_ERRATA_458693
+	bool "ARM errata: Processor deadlock when a false hazard is created"
+	depends on CPU_V7
+	help
+	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
+	  erratum. For very specific sequences of memory operations, it is
+	  possible for a hazard condition intended for a cache line to instead
+	  be incorrectly associated with a different cache line. This false
+	  hazard might then cause a processor deadlock. The workaround enables
+	  the L1 caching of the NEON accesses and disables the PLD instruction
+	  in the ACTLR register. Note that setting specific bits in the ACTLR
+	  register may not be available in non-secure mode.
+
 endmenu
 
 source "arch/arm/common/Kconfig"