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authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-10 12:47:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-10 12:47:57 -0700
commit45ba8d5d061b13494c2a7a7652d51b9da3d9e77a (patch)
treedddb4253b06a58609407ced51aaaf475f724baae /Documentation/DMA-API.txt
parentbb97be23db2a296c5f8b8b4c40feb0435b068c5e (diff)
parentcfdbb4ed31aa777d59b288810f66eb06249ee5b7 (diff)
downloadlinux-45ba8d5d061b13494c2a7a7652d51b9da3d9e77a.tar.gz
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')
-rw-r--r--Documentation/DMA-API.txt8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 586643642910..0076150fdccb 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
 --------------------------------