arm64/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.  Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index e040827..ae9f817 100644 (file)
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -558,7 +558,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
                                 unsigned long attrs)
 {
        bool coherent = is_device_dma_coherent(dev);
-       int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
+       int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
        size_t iosize = size;
        void *addr;
 
@@ -712,7 +712,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
                                   unsigned long attrs)
 {
        bool coherent = is_device_dma_coherent(dev);
-       int prot = dma_direction_to_prot(dir, coherent);
+       int prot = dma_info_to_prot(dir, coherent, attrs);
        dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 
        if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -770,7 +770,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
                __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
 
        return iommu_dma_map_sg(dev, sgl, nelems,
-                       dma_direction_to_prot(dir, coherent));
+                               dma_info_to_prot(dir, coherent, attrs));
 }
 
 static void __iommu_unmap_sg_attrs(struct device *dev,

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 2db0d64..3006eee 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -181,16 +181,22 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
 /**
- * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
+ * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
+ *                    page flags.
  * @dir: Direction of DMA transfer
  * @coherent: Is the DMA master cache-coherent?
+ * @attrs: DMA attributes for the mapping
  *
  * Return: corresponding IOMMU API page protection flags
  */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+                    unsigned long attrs)
 {
        int prot = coherent ? IOMMU_CACHE : 0;
 
+       if (attrs & DMA_ATTR_PRIVILEGED)
+               prot |= IOMMU_PRIV;
+
        switch (dir) {
        case DMA_BIDIRECTIONAL:
                return prot | IOMMU_READ | IOMMU_WRITE;
@@ -633,7 +639,7 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
                size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
        return __iommu_dma_map(dev, phys, size,
-                       dma_direction_to_prot(dir, false) | IOMMU_MMIO);
+                       dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);
 }
 
 void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,

diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 7f7e9a7..c5511e1 100644 (file)
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -34,7 +34,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
                u64 size, struct device *dev);
 
 /* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
+int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+                    unsigned long attrs);
 
 /*
  * These implement the bulk of the relevant DMA mapping callbacks, but require