path: root/Documentation/DMA-API.txt
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-10 19:47:57 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-10 19:47:57 (GMT)
commit45ba8d5d061b13494c2a7a7652d51b9da3d9e77a (patch)
treedddb4253b06a58609407ced51aaaf475f724baae /Documentation/DMA-API.txt
parentbb97be23db2a296c5f8b8b4c40feb0435b068c5e (diff)
parentcfdbb4ed31aa777d59b288810f66eb06249ee5b7 (diff)
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin: "Several fixes, most notably fix for virtio on swiotlb systems" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost: silence an unused-variable warning virtio: hint if callbacks surprisingly might sleep virtio-ccw: wire up ->bus_name callback s390/virtio: handle find on invalid queue gracefully virtio-ccw: diag 500 may return a negative cookie virtio_balloon: remove the unnecessary 0-initialization virtio-balloon: improve update_balloon_size_func virtio-blk: Consider virtio_max_dma_size() for maximum segment size virtio: Introduce virtio_max_dma_size() dma: Introduce dma_max_mapping_size() swiotlb: Add is_swiotlb_active() function swiotlb: Introduce swiotlb_max_mapping_size()
Diffstat (limited to 'Documentation/DMA-API.txt')
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 5866436..0076150 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -195,6 +195,14 @@ Requesting the required mask does not alter the current mask. If you
wish to take advantage of it, you should issue a dma_set_mask()
call to set the mask to the value returned.
+ size_t
+ dma_direct_max_mapping_size(struct device *dev);
+Returns the maximum size of a mapping for the device. The size parameter
+of the mapping functions like dma_map_single(), dma_map_page() and
+others should not be larger than the returned value.
Part Id - Streaming DMA mappings