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@brainfault.org Cc: stable@vger.kernel.org --- 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);