Re: [Linux-stable-mirror] [PATCH RESEND] rpmsg: virtio_rpmsg_bus: fix rpmsg_probe() for virtio-mmio transport

On Wed, Jan 10, 2018 at 6:46 PM, Anup Patel anup@brainfault.org 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@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);
  

-- 2.7.4

Hi All,

Any comments on this??

Regards, Anup