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authorJoerg Roedel <jroedel@suse.de>2019-02-07 14:59:16 +0300
committerMichael S. Tsirkin <mst@redhat.com>2019-03-06 19:19:15 +0300
commite6d6dd6c875eb3c9b69bb640419405726e6e0bbe (patch)
tree0392d073aef16f875c6772cdda08554d8798a45a /include/linux/virtio.h
parent133d624b1cee16906134e92d5befb843b58bcf31 (diff)
downloadlinux-e6d6dd6c875eb3c9b69bb640419405726e6e0bbe.tar.xz
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.h2
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)