[media] v4l: vb2-vmalloc: add support for dmabuf importing

This patch adds support for importing DMABUF files for
vmalloc allocator in Videobuf2.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 57 insertions, 0 deletions

diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig
index e30583b88420..65875c3aba1b 100644
--- a/drivers/media/v4l2-core/Kconfig
+++ b/drivers/media/v4l2-core/Kconfig
@@ -75,6 +75,7 @@ config VIDEOBUF2_VMALLOC
         tristate
         select VIDEOBUF2_CORE
         select VIDEOBUF2_MEMOPS
+        select DMA_SHARED_BUFFER
 
 config VIDEOBUF2_DMA_SG
         tristate
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index 94efa04d8d55..a47fd4f589a1 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -30,6 +30,7 @@ struct vb2_vmalloc_buf {
         unsigned int                    n_pages;
         atomic_t                        refcount;
         struct vb2_vmarea_handler       handler;
+        struct dma_buf                  *dbuf;
 };
 
 static void vb2_vmalloc_put(void *buf_priv);
@@ -207,11 +208,66 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
         return 0;
 }
 
+/*********************************************/
+/*       callbacks for DMABUF buffers        */
+/*********************************************/
+
+static int vb2_vmalloc_map_dmabuf(void *mem_priv)
+{
+        struct vb2_vmalloc_buf *buf = mem_priv;
+
+        buf->vaddr = dma_buf_vmap(buf->dbuf);
+
+        return buf->vaddr ? 0 : -EFAULT;
+}
+
+static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
+{
+        struct vb2_vmalloc_buf *buf = mem_priv;
+
+        dma_buf_vunmap(buf->dbuf, buf->vaddr);
+        buf->vaddr = NULL;
+}
+
+static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
+{
+        struct vb2_vmalloc_buf *buf = mem_priv;
+
+        if (buf->vaddr)
+                dma_buf_vunmap(buf->dbuf, buf->vaddr);
+
+        kfree(buf);
+}
+
+static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
+        unsigned long size, int write)
+{
+        struct vb2_vmalloc_buf *buf;
+
+        if (dbuf->size < size)
+                return ERR_PTR(-EFAULT);
+
+        buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+        if (!buf)
+                return ERR_PTR(-ENOMEM);
+
+        buf->dbuf = dbuf;
+        buf->write = write;
+        buf->size = size;
+
+        return buf;
+}
+
+
 const struct vb2_mem_ops vb2_vmalloc_memops = {
         .alloc          = vb2_vmalloc_alloc,
         .put            = vb2_vmalloc_put,
         .get_userptr    = vb2_vmalloc_get_userptr,
         .put_userptr    = vb2_vmalloc_put_userptr,
+        .map_dmabuf     = vb2_vmalloc_map_dmabuf,
+        .unmap_dmabuf   = vb2_vmalloc_unmap_dmabuf,
+        .attach_dmabuf  = vb2_vmalloc_attach_dmabuf,
+        .detach_dmabuf  = vb2_vmalloc_detach_dmabuf,
         .vaddr          = vb2_vmalloc_vaddr,
         .mmap           = vb2_vmalloc_mmap,
         .num_users      = vb2_vmalloc_num_users,