diff options
Diffstat (limited to 'arch/arm/mm/Kconfig')
-rw-r--r-- | arch/arm/mm/Kconfig | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 270c8e2a4490..33027301639e 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig | |||
@@ -755,7 +755,7 @@ config 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 || \ | 757 | REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || \ |
758 | ARCH_NOMADIK || ARCH_OMAP4 || ARCH_VEXPRESS_CA9X4 | 758 | ARCH_NOMADIK || ARCH_OMAP4 || ARCH_U8500 || ARCH_VEXPRESS_CA9X4 |
759 | default y | 759 | default y |
760 | select OUTER_CACHE | 760 | select OUTER_CACHE |
761 | help | 761 | help |
@@ -782,3 +782,22 @@ config ARM_L1_CACHE_SHIFT | |||
782 | int | 782 | int |
783 | default 6 if ARM_L1_CACHE_SHIFT_6 | 783 | default 6 if ARM_L1_CACHE_SHIFT_6 |
784 | default 5 | 784 | default 5 |
785 | |||
786 | config 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. | ||