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authorHalil Pasic <pasic@linux.ibm.com>2019-04-26 21:32:37 +0300
committerMichael S. Tsirkin <mst@redhat.com>2019-05-12 20:11:36 +0300
commitf35f54f11f7f96dc6d43fa79c4a7297a9115627f (patch)
treec813bbc7f8df0a63eda719712b5a455038fd8311 /drivers/s390
parent3279beac545190ed252cd3df0eb41056537463df (diff)
downloadlinux-f35f54f11f7f96dc6d43fa79c4a7297a9115627f.tar.xz
virtio/s390: DMA support for virtio-ccw
Currently virtio-ccw devices do not work if the device has VIRTIO_F_IOMMU_PLATFORM. In future we do want to support DMA API with virtio-ccw. Let us do the plumbing, so the feature VIRTIO_F_IOMMU_PLATFORM works with virtio-ccw. Let us also switch from legacy avail/used accessors to the DMA aware ones (even if it isn't strictly necessary), and remove the legacy accessors (we were the last users). Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/virtio/virtio_ccw.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 2c66941ef3d0..42832a164546 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -66,6 +66,7 @@ struct virtio_ccw_device {
bool device_lost;
unsigned int config_ready;
void *airq_info;
+ u64 dma_mask;
};
struct vq_info_block_legacy {
@@ -539,8 +540,8 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
info->info_block->s.desc = queue;
info->info_block->s.index = i;
info->info_block->s.num = info->num;
- info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
- info->info_block->s.used = (__u64)virtqueue_get_used(vq);
+ info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
+ info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
ccw->count = sizeof(info->info_block->s);
}
ccw->cmd_code = CCW_CMD_SET_VQ;
@@ -772,10 +773,8 @@ out_free:
static void ccw_transport_features(struct virtio_device *vdev)
{
/*
- * Packed ring isn't enabled on virtio_ccw for now,
- * because virtio_ccw uses some legacy accessors,
- * e.g. virtqueue_get_avail() and virtqueue_get_used()
- * which aren't available in packed ring currently.
+ * There shouldn't be anything that precludes supporting packed.
+ * TODO: Remove the limitation after having another look into this.
*/
__virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
}
@@ -1258,6 +1257,16 @@ static int virtio_ccw_online(struct ccw_device *cdev)
ret = -ENOMEM;
goto out_free;
}
+
+ vcdev->vdev.dev.parent = &cdev->dev;
+ cdev->dev.dma_mask = &vcdev->dma_mask;
+ /* we are fine with common virtio infrastructure using 64 bit DMA */
+ ret = dma_set_mask_and_coherent(&cdev->dev, DMA_BIT_MASK(64));
+ if (ret) {
+ dev_warn(&cdev->dev, "Failed to enable 64-bit DMA.\n");
+ goto out_free;
+ }
+
vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
GFP_DMA | GFP_KERNEL);
if (!vcdev->config_block) {
@@ -1272,7 +1281,6 @@ static int virtio_ccw_online(struct ccw_device *cdev)
vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
- vcdev->vdev.dev.parent = &cdev->dev;
vcdev->vdev.dev.release = virtio_ccw_release_dev;
vcdev->vdev.config = &virtio_ccw_config_ops;
vcdev->cdev = cdev;