Previously the vb2_dma_contig_mmap() function was using a dma_addr_t as a
physical address.  The two addressses are not necessarily the same.
For example, when using the IOMMU funtion on certain platforms, dma_addr_t
addresses are not directly mappable physical address.
dma_mmap_coherent() maps the address correctly.
It is available on ARM platforms.

Signed-off-by: Hideki EIRAKU <h...@igel.co.jp>
---
 drivers/media/video/videobuf2-dma-contig.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c 
b/drivers/media/video/videobuf2-dma-contig.c
index 4b71326..4dc85ab 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -101,14 +101,32 @@ static unsigned int vb2_dma_contig_num_users(void 
*buf_priv)
 static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma)
 {
        struct vb2_dc_buf *buf = buf_priv;
+#ifdef ARCH_HAS_DMA_MMAP_COHERENT
+       int ret;
+#endif
 
        if (!buf) {
                printk(KERN_ERR "No buffer to map\n");
                return -EINVAL;
        }
 
+#ifdef ARCH_HAS_DMA_MMAP_COHERENT
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+       ret = dma_mmap_coherent(buf->conf->dev, vma, buf->vaddr, buf->dma_addr,
+                               buf->size);
+       if (ret) {
+               pr_err("Remapping memory failed, error: %d\n", ret);
+               return ret;
+       }
+       vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
+       vma->vm_private_data = &buf->handler;
+       vma->vm_ops = &vb2_common_vm_ops;
+       vma->vm_ops->open(vma);
+       return 0;
+#else
        return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size,
                                  &vb2_common_vm_ops, &buf->handler);
+#endif
 }
 
 static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
-- 
1.7.0.4

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