Re: [PATCH 1/2] dma-mapping: fix page attributes for dma_mmap_*
flat view
From: Christoph Hellwig <hch@lst.de>
Date: 2019-08-06 05:12:48
Also in:
linux-mips, linuxppc-dev, lkml
On Mon, Aug 05, 2019 at 07:55:44PM -0700, Gavin Li wrote:
quoted
/* create a coherent mapping */ ret = dma_common_contiguous_remap(page, size, VM_USERMAP, - arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs), + dma_pgprot(dev, PAGE_KERNEL, attrs), __builtin_return_address(0)); if (!ret) { __dma_direct_free_pages(dev, size, page);Is dma_common_contiguous_remap() still necessary in the DMA_ATTR_NON_CONSISTENT case? I would presume it would be fine to just return a linearly mapped address in that case.
It would not be required for a real DMA_ATTR_NON_CONSISTENT implementation. But only parisc and mips actually properly implement DMA_ATTR_NON_CONSISTENT, everyone ignores it. Given that the API is a little ill defined and I have a better replacement in the pipeline I don't want to start implementing it for other architectures now. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel