Re: [PATCH 0/6] drm+dma: cache support for arm, etc
From: Christoph Hellwig <hch@lst.de>
Date: 2019-08-15 18:52:16
Also in:
dri-devel, linuxppc-dev
On Thu, Aug 15, 2019 at 06:48:39PM +0000, Koenig, Christian wrote:
Well, for the graphics case I absolutely need to keep the linear kernel mapping. Because for certain use cases the memory is accessed by the kernel all the time as well.
Then don't set DMA_ATTR_NO_KERNEL_MAPPING. At least for x86 and arm64 we should be able to support uncached allocations easily even without that, and I plan to support that for your use case. But if the driver is explicitly saying it doesn't want a permanent kernel mapping it makes sense to (optionally if the architecture can easily do it) unmap the memory from the kernel linear mapping. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel