Hello,
On Wednesday, June 13, 2012 8:52 PM Daniel Vetter wrote:
On Wed, Jun 13, 2012 at 01:50:13PM +0200, Marek Szyprowski wrote:
This patch adds DMA_ATTR_NO_KERNEL_MAPPING attribute which lets the platform to avoid creating a kernel virtual mapping for the allocated buffer. On some architectures creating such mapping is non-trivial task and consumes very limited resources (like kernel virtual address space or dma consistent address space). Buffers allocated with this attribute can be only passed to user space by calling dma_mmap_attrs().
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com
Looks like a nice little extension to support dma-buf for the common case, so:
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
One question is whether we should go right ahead and add kmap support for this, too (with a default implementation that simply returns a pointer to the coherent&contigous dma mem), but I guess that can wait until a use-case pops up.
I will wait with this until there will be real use cases. Let's get the patch into mainline first.
Best regards