Displaying 5 results from an estimated 5 matches for "of_dma_is_coherent".
2017 Feb 01
3
[PATCH] virtio: Try to untangle DMA coherency
...Some devices (e.g. virtio-mmio) are implicitly cache coherent with respect
to DMA operations and therefore do not mandate the use of "dma-coherent"
in their devicetree bindings. In order to ensure that these devices work
correctly when using the DMA API, we need to treat them specially in
of_dma_is_coherent by identifying them as unconditionally coherent.
This patch adds a static, table-based search against the compatible
string for the device in of_dma_is_coherent before walking the
hierarchy looking for "dma-coherent". This allows existing virtio-mmio
devices (e.g. those emulated by QEMU)...
2017 Feb 01
3
[PATCH] virtio: Try to untangle DMA coherency
...Some devices (e.g. virtio-mmio) are implicitly cache coherent with respect
to DMA operations and therefore do not mandate the use of "dma-coherent"
in their devicetree bindings. In order to ensure that these devices work
correctly when using the DMA API, we need to treat them specially in
of_dma_is_coherent by identifying them as unconditionally coherent.
This patch adds a static, table-based search against the compatible
string for the device in of_dma_is_coherent before walking the
hierarchy looking for "dma-coherent". This allows existing virtio-mmio
devices (e.g. those emulated by QEMU)...
2017 Feb 01
0
[PATCH] virtio: Try to untangle DMA coherency
...irtio-mmio) are implicitly cache coherent with respect
> to DMA operations and therefore do not mandate the use of "dma-coherent"
> in their devicetree bindings. In order to ensure that these devices work
> correctly when using the DMA API, we need to treat them specially in
> of_dma_is_coherent by identifying them as unconditionally coherent.
>
> This patch adds a static, table-based search against the compatible
> string for the device in of_dma_is_coherent before walking the
> hierarchy looking for "dma-coherent". This allows existing virtio-mmio
> devices (e.g...
2017 Feb 01
4
[PATCH] virtio: Try to untangle DMA coherency
By forcing on DMA API usage for ARM systems, we have inadvertently
kicked open a hornets' nest in terms of cache-coherency. Namely that
unless the virtio device is explicitly described as capable of coherent
DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
assume it is non-coherent. This turns out to cause a big problem for the
likes of QEMU and kvmtool, which generate
2017 Feb 01
4
[PATCH] virtio: Try to untangle DMA coherency
By forcing on DMA API usage for ARM systems, we have inadvertently
kicked open a hornets' nest in terms of cache-coherency. Namely that
unless the virtio device is explicitly described as capable of coherent
DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
assume it is non-coherent. This turns out to cause a big problem for the
likes of QEMU and kvmtool, which generate