[RFC PATCH 13/22] rpmsg: virtio_rpmsg_bus: Use virtio_alloc_buffer() and virtio_free_buffer()

[Kishon Vijay Abraham I]

Use virtio_alloc_buffer() and virtio_free_buffer() to allocate and free
memory buffer respectively. Only if buffer allocation using
virtio_alloc_buffer() try using dma_alloc_coherent(). This is required
for devices like NTB to use rpmsg for communicating with other host.

Signed-off-by: Kishon Vijay Abraham I <kis...@ti.com>
---
 drivers/rpmsg/virtio_rpmsg_bus.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index f91143b25af7..2b25a8ae1539 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -882,13 +882,16 @@ static int rpmsg_probe(struct virtio_device *vdev)
 
        total_buf_space = vrp->num_bufs * vrp->buf_size;
 
-       /* allocate coherent memory for the buffers */
-       bufs_va = dma_alloc_coherent(vdev->dev.parent,
-                                    total_buf_space, &vrp->bufs_dma,
-                                    GFP_KERNEL);
+       bufs_va = virtio_alloc_buffer(vdev, total_buf_space);
        if (!bufs_va) {
-               err = -ENOMEM;
-               goto vqs_del;
+               /* allocate coherent memory for the buffers */
+               bufs_va = dma_alloc_coherent(vdev->dev.parent,
+                                            total_buf_space, &vrp->bufs_dma,
+                                            GFP_KERNEL);
+               if (!bufs_va) {
+                       err = -ENOMEM;
+                       goto vqs_del;
+               }
        }
 
        dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n",
@@ -951,8 +954,13 @@ static int rpmsg_probe(struct virtio_device *vdev)
        return 0;
 
 free_coherent:
-       dma_free_coherent(vdev->dev.parent, total_buf_space,
-                         bufs_va, vrp->bufs_dma);
+       if (!vrp->bufs_dma) {
+               virtio_free_buffer(vdev, bufs_va, total_buf_space);
+       } else {
+               dma_free_coherent(vdev->dev.parent, total_buf_space,
+                                 bufs_va, vrp->bufs_dma);
+       }
+
 vqs_del:
        vdev->config->del_vqs(vrp->vdev);
 free_vrp:
@@ -986,8 +994,12 @@ static void rpmsg_remove(struct virtio_device *vdev)
 
        vdev->config->del_vqs(vrp->vdev);
 
-       dma_free_coherent(vdev->dev.parent, total_buf_space,
-                         vrp->rbufs, vrp->bufs_dma);
+       if (!vrp->bufs_dma) {
+               virtio_free_buffer(vdev, vrp->rbufs, total_buf_space);
+       } else {
+               dma_free_coherent(vdev->dev.parent, total_buf_space,
+                                 vrp->rbufs, vrp->bufs_dma);
+       }
 
        kfree(vrp);
 }
-- 
2.17.1