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authorCatalin Marinas <catalin.marinas@arm.com>2014-03-24 11:35:35 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-03-24 11:35:35 +0100
commit196adf2f3015eacac0567278ba538e3ffdd16d0e (patch)
tree2dc6514b3263a9f3ed69b3b0ff34ef908afa5af7 /arch
parentarm64: Support DMA_ATTR_WRITE_COMBINE (diff)
downloadlinux-196adf2f3015eacac0567278ba538e3ffdd16d0e.tar.xz
linux-196adf2f3015eacac0567278ba538e3ffdd16d0e.zip
arm64: Remove pgprot_dmacoherent()
Since this macro is identical to pgprot_writecombine() and is only used in a single place, remove it completely to avoid confusion. On ARMv7+ processors, the coherent DMA mapping must be Normal NonCacheable (a.k.a. writecombine) to avoid mismatched hardware attribute aliases (with the kernel linear mapping as Normal Cacheable). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/pgtable.h2
-rw-r--r--arch/arm64/mm/dma-mapping.c4
2 files changed, 1 insertions, 5 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index ae10350f75ec..da92265bd798 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -280,8 +280,6 @@ static inline int has_transparent_hugepage(void)
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
#define pgprot_writecombine(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
-#define pgprot_dmacoherent(prot) \
- __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 5bba6be1a3f1..0ba347e59f06 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -33,10 +33,8 @@ EXPORT_SYMBOL(dma_ops);
static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
bool coherent)
{
- if (dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
+ if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
return pgprot_writecombine(prot);
- else if (!coherent)
- return pgprot_dmacoherent(prot);
return prot;
}