From 6b185a7d18246ecd52ce3da955fa589f6b8c99ec Mon Sep 17 00:00:00 2001
From: Laura Abbott <lauraa@codeaurora.org>
Date: Fri, 14 Mar 2014 19:52:24 +0000
Subject: [PATCH] arm64: Support DMA_ATTR_WRITE_COMBINE
DMA_ATTR_WRITE_COMBINE is currently ignored. Set the pgprot
appropriately for non coherent opperations.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 214fdbe74a096c3aeb7af81d7900e2ab966b10d6)
Signed-off-by: Mark Brown <broonie@linaro.org>
---
arch/arm64/mm/dma-mapping.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 18b83177f4b6..e5eef09808b6 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -30,6 +30,16 @@
struct dma_map_ops *dma_ops;
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))
+ return pgprot_writecombine(prot);
+ else if (!coherent)
+ return pgprot_dmacoherent(prot);
+ return prot;
+}
+
static void *__dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
@@ -99,7 +109,7 @@ static void *__dma_alloc_noncoherent(struct device *dev, size_t size,
for (i = 0; i < (size >> PAGE_SHIFT); i++)
map[i] = page + i;
coherent_ptr = vmap(map, size >> PAGE_SHIFT, VM_MAP,
- pgprot_dmacoherent(pgprot_default));
+ __get_dma_pgprot(attrs, pgprot_default, false));
kfree(map);
if (!coherent_ptr)
goto no_map;
@@ -245,7 +255,7 @@ static int __swiotlb_mmap_noncoherent(struct device *dev,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs)
{
- vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
+ vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, false);
return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
}
--
2.34.1