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authorDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-14 17:07:33 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-14 17:07:33 +0300
commitb70366e5d31788650b2a5cec5cd13ea80ac7e44a (patch)
treed972ffd190111d699200448494fda333d28b2486 /Documentation/DMA-attributes.txt
parentf42e181935d5e5670c87d31ae48063a495bbacae (diff)
parentdb6ccf23e8ba40fc2e8914ec9c0eb950df71d9fe (diff)
downloadlinux-b70366e5d31788650b2a5cec5cd13ea80ac7e44a.tar.xz
Merge tag 'doc-4.11-images' of git://git.lwn.net/linux into drm-misc-next
Pointer for Markus's image conversion work. We need this so we can merge all the pretty drm graphs for 4.12. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'Documentation/DMA-attributes.txt')
-rw-r--r--Documentation/DMA-attributes.txt10
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt
index 98bf7ac29aad..44c6bc496eee 100644
--- a/Documentation/DMA-attributes.txt
+++ b/Documentation/DMA-attributes.txt
@@ -143,3 +143,13 @@ So, this provides a way for drivers to avoid those error messages on calls
where allocation failures are not a problem, and shouldn't bother the logs.
NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC.
+
+DMA_ATTR_PRIVILEGED
+------------------------------
+
+Some advanced peripherals such as remote processors and GPUs perform
+accesses to DMA buffers in both privileged "supervisor" and unprivileged
+"user" modes. This attribute is used to indicate to the DMA-mapping
+subsystem that the buffer is fully accessible at the elevated privilege
+level (and ideally inaccessible or at least read-only at the
+lesser-privileged levels).