On Wed, Jan 10, 2018 at 6:46 PM, Anup Patel <anup@xxxxxxxxxxxxxx> wrote:
> When virtio-rpmsg device is provided via virtio-mmio transport, the
> dma_alloc_coherent() (called by rpmsg_probe()) fails on ARM/ARM64
> systems because "vdev->dev.parent->parent" device is used as parameter
> to dma_alloc_coherent().
>
> The "vdev->dev.parent->parent" device represents underlying remoteproc
> platform device when virtio-rpmsg device is provided via virtio-remoteproc
> transport. When virtio-rpmsg device is provided via virtio-mmio transport,
> the "vdev->dev.parent->parent" device represents the parent device of
> virtio-mmio platform device and dma_alloc_coherent() fails for this device
> because generally there is no corresponding platform device and dma_ops
> are not setup for "vdev->dev.parent->parent".
>
> This patch fixes dma_alloc_coherent() usage in rpmsg_probe() by trying
> dma_alloc_coherent() with "vdev->dev.parent" device when it fails with
> "vdev->dev.parent->parent" device.
>
> Fixes: b5ab5e24e960 ("remoteproc: maintain a generic child device for
> each rproc")
>
> Signed-off-by: Anup Patel <anup@xxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/rpmsg/virtio_rpmsg_bus.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
> index 82b8300..7f8710a 100644
> --- a/drivers/rpmsg/virtio_rpmsg_bus.c
> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
> @@ -64,6 +64,7 @@
> struct virtproc_info {
> struct virtio_device *vdev;
> struct virtqueue *rvq, *svq;
> + struct device *bufs_dev;
> void *rbufs, *sbufs;
> unsigned int num_bufs;
> unsigned int buf_size;
> @@ -924,9 +925,16 @@ static int rpmsg_probe(struct virtio_device *vdev)
> total_buf_space, &vrp->bufs_dma,
> GFP_KERNEL);
> if (!bufs_va) {
> - err = -ENOMEM;
> - goto vqs_del;
> - }
> + bufs_va = dma_alloc_coherent(vdev->dev.parent,
> + total_buf_space, &vrp->bufs_dma,
> + GFP_KERNEL);
> + if (!bufs_va) {
> + err = -ENOMEM;
> + goto vqs_del;
> + } else
> + vrp->bufs_dev = vdev->dev.parent;
> + } else
> + vrp->bufs_dev = vdev->dev.parent->parent;
>
> dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n",
> bufs_va, &vrp->bufs_dma);
> @@ -988,7 +996,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
> return 0;
>
> free_coherent:
> - dma_free_coherent(vdev->dev.parent->parent, total_buf_space,
> + dma_free_coherent(vrp->bufs_dev, total_buf_space,
> bufs_va, vrp->bufs_dma);
> vqs_del:
> vdev->config->del_vqs(vrp->vdev);
> @@ -1023,7 +1031,7 @@ static void rpmsg_remove(struct virtio_device *vdev)
>
> vdev->config->del_vqs(vrp->vdev);
>
> - dma_free_coherent(vdev->dev.parent->parent, total_buf_space,
> + dma_free_coherent(vrp->bufs_dev, total_buf_space,
> vrp->rbufs, vrp->bufs_dma);
>
> kfree(vrp);
> --
> 2.7.4
>
Hi All,
Any comments on this??
Regards,
Anup