arm: dma-mapping: add {map,unmap}_resource for iommu ops

Add methods to map/unmap device resources addresses for dma_map_ops that
are IOMMU aware. This is needed to map a device MMIO register from a
physical address.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c6834c0..746eb29 100644 (file)
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2014,6 +2014,63 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
        __free_iova(mapping, iova, len);
 }
 
+/**
+ * arm_iommu_map_resource - map a device resource for DMA
+ * @dev: valid struct device pointer
+ * @phys_addr: physical address of resource
+ * @size: size of resource to map
+ * @dir: DMA transfer direction
+ */
+static dma_addr_t arm_iommu_map_resource(struct device *dev,
+               phys_addr_t phys_addr, size_t size,
+               enum dma_data_direction dir, unsigned long attrs)
+{
+       struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
+       dma_addr_t dma_addr;
+       int ret, prot;
+       phys_addr_t addr = phys_addr & PAGE_MASK;
+       unsigned int offset = phys_addr & ~PAGE_MASK;
+       size_t len = PAGE_ALIGN(size + offset);
+
+       dma_addr = __alloc_iova(mapping, len);
+       if (dma_addr == DMA_ERROR_CODE)
+               return dma_addr;
+
+       prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;
+
+       ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
+       if (ret < 0)
+               goto fail;
+
+       return dma_addr + offset;
+fail:
+       __free_iova(mapping, dma_addr, len);
+       return DMA_ERROR_CODE;
+}
+
+/**
+ * arm_iommu_unmap_resource - unmap a device DMA resource
+ * @dev: valid struct device pointer
+ * @dma_handle: DMA address to resource
+ * @size: size of resource to map
+ * @dir: DMA transfer direction
+ */
+static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle,
+               size_t size, enum dma_data_direction dir,
+               unsigned long attrs)
+{
+       struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
+       dma_addr_t iova = dma_handle & PAGE_MASK;
+       unsigned int offset = dma_handle & ~PAGE_MASK;
+       size_t len = PAGE_ALIGN(size + offset);
+
+       if (!iova)
+               return;
+
+       iommu_unmap(mapping->domain, iova, len);
+       __free_iova(mapping, iova, len);
+}
+
 static void arm_iommu_sync_single_for_cpu(struct device *dev,
                dma_addr_t handle, size_t size, enum dma_data_direction dir)
 {
@@ -2057,6 +2114,9 @@ struct dma_map_ops iommu_ops = {
        .unmap_sg               = arm_iommu_unmap_sg,
        .sync_sg_for_cpu        = arm_iommu_sync_sg_for_cpu,
        .sync_sg_for_device     = arm_iommu_sync_sg_for_device,
+
+       .map_resource           = arm_iommu_map_resource,
+       .unmap_resource         = arm_iommu_unmap_resource,
 };
 
 struct dma_map_ops iommu_coherent_ops = {
@@ -2070,6 +2130,9 @@ struct dma_map_ops iommu_coherent_ops = {
 
        .map_sg         = arm_coherent_iommu_map_sg,
        .unmap_sg       = arm_coherent_iommu_unmap_sg,
+
+       .map_resource   = arm_iommu_map_resource,
+       .unmap_resource = arm_iommu_unmap_resource,
 };
 
 /**