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| author | Linus Torvalds | 2022-02-27 12:42:37 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2022-02-27 12:42:37 -0800 |
| commit | 98f3e84f8df66f1ac9d04b6d8093993c9bfd69e6 (patch) | |
| tree | 2b63116b52a5ba74ee2565b3f13454b300947777 /Documentation | |
| parent | 6676ba2a6df6864a6b7b11f20166026e2201b627 (diff) | |
| parent | ddbd89deb7d32b1fbb879f48d68fda1a8ac58e8e (diff) | |
Merge tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fix from Christoph Hellwig:
- fix a swiotlb info leak (Halil Pasic)
* tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: fix info leak with DMA_FROM_DEVICE
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/core-api/dma-attributes.rst | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 1887d92e8e92..17706dc91ec9 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -130,3 +130,11 @@ accesses to DMA buffers in both privileged "supervisor" and unprivileged 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). + +DMA_ATTR_OVERWRITE +------------------ + +This is a hint to the DMA-mapping subsystem that the device is expected to +overwrite the entire mapped size, thus the caller does not require any of the +previous buffer contents to be preserved. This allows bounce-buffering +implementations to optimise DMA_FROM_DEVICE transfers. |