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authorRussell King <rmk+kernel@arm.linux.org.uk>2010-05-15 11:02:43 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-05-17 11:52:11 +0100
commit47ab0dee661dbd5aca67abe44a333e471134fbf9 (patch)
tree6464acf6eb3cd42102fa70e160335626354edfc1 /arch/arm/include
parent8c0b742ca7a7d21de0ddc87eda6ef0b282e4de18 (diff)
ARM: Optionally allow ARMv6 to use 'normal, bufferable' memory for DMA
Provide a configuration option to allow the ARMv6 to use normal bufferable memory for coherent DMA. This option is forced to 'y' for ARMv7, and offered as a configuration option on ARMv6. Enabling this option requires drivers to have the necessary barriers to ensure that data in DMA coherent memory is visible prior to the DMA operation commencing. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include')
-rw-r--r--arch/arm/include/asm/pgtable.h2
-rw-r--r--arch/arm/include/asm/system.h2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 11397687f42..ab68cf1ef80 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -314,7 +314,7 @@ static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
#define pgprot_writecombine(prot) \
__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
-#if __LINUX_ARM_ARCH__ >= 7
+#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#define pgprot_dmacoherent(prot) \
__pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_BUFFERABLE)
#else
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index ca88e6a8470..02f5d99adbc 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -137,7 +137,7 @@ extern unsigned int user_debug;
#define dmb() __asm__ __volatile__ ("" : : : "memory")
#endif
-#if __LINUX_ARM_ARCH__ >= 7 || defined(CONFIG_SMP)
+#if defined(CONFIG_ARM_DMA_MEM_BUFFERABLE) || defined(CONFIG_SMP)
#define mb() dmb()
#define rmb() dmb()
#define wmb() dmb()