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-rw-r--r--arch/arm/mm/Kconfig22
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index c4ed9f93f64..33027301639 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -754,7 +754,8 @@ config CACHE_FEROCEON_L2_WRITETHROUGH
754config CACHE_L2X0 754config CACHE_L2X0
755 bool "Enable the L2x0 outer cache controller" 755 bool "Enable the L2x0 outer cache controller"
756 depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \ 756 depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \
757 REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || ARCH_NOMADIK || ARCH_OMAP4 757 REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || \
758 ARCH_NOMADIK || ARCH_OMAP4 || ARCH_U8500 || ARCH_VEXPRESS_CA9X4
758 default y 759 default y
759 select OUTER_CACHE 760 select OUTER_CACHE
760 help 761 help
@@ -781,3 +782,22 @@ config ARM_L1_CACHE_SHIFT
781 int 782 int
782 default 6 if ARM_L1_CACHE_SHIFT_6 783 default 6 if ARM_L1_CACHE_SHIFT_6
783 default 5 784 default 5
785
786config ARM_DMA_MEM_BUFFERABLE
787 bool "Use non-cacheable memory for DMA" if CPU_V6 && !CPU_V7
788 default y if CPU_V6 || CPU_V7
789 help
790 Historically, the kernel has used strongly ordered mappings to
791 provide DMA coherent memory. With the advent of ARMv7, mapping
792 memory with differing types results in unpredictable behaviour,
793 so on these CPUs, this option is forced on.
794
795 Multiple mappings with differing attributes is also unpredictable
796 on ARMv6 CPUs, but since they do not have aggressive speculative
797 prefetch, no harm appears to occur.
798
799 However, drivers may be missing the necessary barriers for ARMv6,
800 and therefore turning this on may result in unpredictable driver
801 behaviour. Therefore, we offer this as an option.
802
803 You are recommended say 'Y' here and debug any affected drivers.