1 files changed, 26 insertions, 0 deletions

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 60aab5a7522b..cd8aad8226dd 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -105,6 +105,31 @@ static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
         __free_pages(page, get_order(size));
 }
 
+static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+                        void *cpu_addr, dma_addr_t dma_addr, size_t size,
+                        unsigned long attrs)
+{
+        unsigned long user_count = vma_pages(vma);
+        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+        unsigned long pfn = __phys_to_pfn(plat_dma_to_phys(dev, dma_addr));
+        unsigned long off = vma->vm_pgoff;
+        int ret = -ENXIO;
+
+        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+        if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+                return ret;
+
+        if (off < count && user_count <= (count - off)) {
+                ret = remap_pfn_range(vma, vma->vm_start,
+                                      pfn + off,
+                                      user_count << PAGE_SHIFT,
+                                      vma->vm_page_prot);
+        }
+
+        return ret;
+}
+
 /*
  * streaming DMA Mapping API...
  * CPU accesses page via normal paddr, thus needs to explicitly made
@@ -193,6 +218,7 @@ static int arc_dma_supported(struct device *dev, u64 dma_mask)
 struct dma_map_ops arc_dma_ops = {
         .alloc                  = arc_dma_alloc,
         .free                   = arc_dma_free,
+        .mmap                   = arc_dma_mmap,
         .map_page               = arc_dma_map_page,
         .map_sg                 = arc_dma_map_sg,
         .sync_single_for_device = arc_dma_sync_single_for_device,