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| author | Joerg Roedel <jroedel@suse.de> | 2017-01-30 16:05:18 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2017-01-30 16:05:18 +0100 |
| commit | ce273db0ff1ae64fea785af25a43977b0b6a4555 (patch) | |
| tree | 1a5d03cb1e5c0d63f298691a980b3e248654619f /Documentation | |
| parent | 93fa6cf60aad833e7572a61f98b2d0aa6f67de40 (diff) | |
| parent | 14b4dbafa7e7e13323e402efd7723aafa391d69a (diff) | |
| download | lwn-ce273db0ff1ae64fea785af25a43977b0b6a4555.tar.gz lwn-ce273db0ff1ae64fea785af25a43977b0b6a4555.zip | |
Merge branch 'iommu/iommu-priv' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into arm/core
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DMA-attributes.txt | 10 |
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). |