[PATCH V7 5/8] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED

From: Sricharan R <redacted>
Date: Tue, 13 Dec 2016 23:25:01 +0530
Subject: [PATCH V8 6/9] arm/dma-mapping: Implement DMA_ATTR_PRIVILEGED

The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Implementing it in dma-mapping
for it to get used from the dma mappings apis.

Signed-off-by: Sricharan R <redacted>
---
 arch/arm/mm/dma-mapping.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab77100..e0d9923 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c

@@ -1394,7 +1394,8 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
  * Create a mapping in device IO address space for specified pages
  */
 static dma_addr_t
-__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
+__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
+		       unsigned long attrs)
 {
 	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

@@ -1419,7 +1420,7 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages,
 
 		len = (j - i) << PAGE_SHIFT;
 		ret = iommu_map(mapping->domain, iova, phys, len,
-				IOMMU_READ|IOMMU_WRITE);
+				__dma_info_to_prot(DMA_BIRECTIONAL, attrs));
 		if (ret < 0)
 			goto fail;
 		iova += len;

@@ -1476,7 +1477,8 @@ static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
 }
 
 static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
-				  dma_addr_t *handle, int coherent_flag)
+				  dma_addr_t *handle, int coherent_flag,
+				  unsigned long attrs)
 {
 	struct page *page;
 	void *addr;

@@ -1488,7 +1490,7 @@ static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
 	if (!addr)
 		return NULL;
 
-	*handle = __iommu_create_mapping(dev, &page, size);
+	*handle = __iommu_create_mapping(dev, &page, size, attrs);
 	if (*handle == DMA_ERROR_CODE)
 		goto err_mapping;
 

@@ -1522,7 +1524,8 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
 
 	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))
 		return __iommu_alloc_simple(dev, size, gfp, handle,
-					    coherent_flag);
+					    coherent_flag,
+					    attrs);

 
 	/*
 	 * Following is a work-around (a.k.a. hack) to prevent pages

@@ -1672,10 +1675,13 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
 					 GFP_KERNEL);
 }
 
-static int __dma_direction_to_prot(enum dma_data_direction dir)
+static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
 {
 	int prot;
 
+	if (attrs & DMA_ATTR_PRIVILEGED)
+		prot |= IOMMU_PRIV;
+
 	switch (dir) {
 	case DMA_BIDIRECTIONAL:
 		prot = IOMMU_READ | IOMMU_WRITE;

@@ -1722,7 +1728,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
 		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
-		prot = __dma_direction_to_prot(dir);
+		prot = __dma_info_to_prot(dir, attrs);
 
 		ret = iommu_map(mapping->domain, iova, phys, len, prot);
 		if (ret < 0)

@@ -1930,7 +1936,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir);
+	prot = __dma_info_to_prot(dir, attrs);
 
 	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
 	if (ret < 0)

@@ -2036,7 +2042,7 @@ static dma_addr_t arm_iommu_map_resource(struct device *dev,
 	if (dma_addr == DMA_ERROR_CODE)
 		return dma_addr;
 
-	prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
 
 	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
 	if (ret < 0)