From: Will Deacon <will.deacon@arm.com>
Date: Mon, 10 Jun 2013 18:34:39 +0000 (+0100)
Subject: ARM: dma-mapping: convert DMA direction into IOMMU protection attributes
X-Git-Tag: upstream/snapshot3+hdmi~4767^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=13987d68bcf476a93fa864ea4e58755f1bc4bd30;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

ARM: dma-mapping: convert DMA direction into IOMMU protection attributes

IOMMU mappings take a prot parameter, identifying the protection bits
to enforce on the newly created mapping (READ or WRITE). The ARM
dma-mapping framework currently just passes 0 as the prot argument,
resulting in faulting mappings.

This patch infers the protection attributes based on the direction of
the DMA transfer.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1d158c2..282aacd 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1637,13 +1637,27 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 {
 	struct dma_iommu_mapping *mapping = dev->archdata.mapping;
 	dma_addr_t dma_addr;
-	int ret, len = PAGE_ALIGN(size + offset);
+	int ret, prot, len = PAGE_ALIGN(size + offset);
 
 	dma_addr = __alloc_iova(mapping, len);
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		prot = IOMMU_READ | IOMMU_WRITE;
+		break;
+	case DMA_TO_DEVICE:
+		prot = IOMMU_READ;
+		break;
+	case DMA_FROM_DEVICE:
+		prot = IOMMU_WRITE;
+		break;
+	default:
+		prot = 0;
+	}
+
+	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
 	if (ret < 0)
 		goto fail;