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| author |   Joerg Roedel <jroedel@suse.de> | 2019-02-07 12:59:16 +0100 |
|---|---|---|
| committer |   Michael S. Tsirkin <mst@redhat.com> | 2019-03-06 11:19:15 -0500 |
| commit | e6d6dd6c875eb3c9b69bb640419405726e6e0bbe (patch) | |
| tree | 0392d073aef16f875c6772cdda08554d8798a45a /include/linux/virtio.h | |
| parent | dma: Introduce dma_max_mapping_size() (diff) | |
| download | wireguard-linux-e6d6dd6c875eb3c9b69bb640419405726e6e0bbe.tar.xz wireguard-linux-e6d6dd6c875eb3c9b69bb640419405726e6e0bbe.zip | |
virtio: Introduce virtio_max_dma_size()
This function returns the maximum segment size for a single
dma transaction of a virtio device. The possible limit comes
from the SWIOTLB implementation in the Linux kernel, that
has an upper limit of (currently) 256kb of contiguous
memory it can map. Other DMA-API implementations might also
have limits.
Use the new dma_max_mapping_size() function to determine the
maximum mapping size when DMA-API is in use for virtio.
Cc: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/linux/virtio.h')
| -rw-r--r-- | include/linux/virtio.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/virtio.h b/include/linux/virtio.h index fa1b5da2804e..673fe3ef3607 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -157,6 +157,8 @@ int virtio_device_freeze(struct virtio_device *dev); int virtio_device_restore(struct virtio_device *dev); #endif +size_t virtio_max_dma_size(struct virtio_device *vdev); + #define virtio_device_for_each_vq(vdev, vq) \ list_for_each_entry(vq, &vdev->vqs, list) |