Re: [PATCH v2 01/11] asm-generic: add dma_zone_size

From
Christoph Hellwig <hch@lst.de>
Date
2019-08-26 07:09:45
Also in
linux-arch, linux-devicetree, linux-iommu, linux-mm, linux-riscv, lkml
Reply to
Nicolas Saenz Julienne, 2019-08-20
On Tue, Aug 20, 2019 at 04:58:09PM +0200, Nicolas Saenz Julienne wrote:
Some architectures have platform specific DMA addressing limitations.
This will allow for hardware description code to provide the constraints
in a generic manner, so as for arch code to properly setup it's memory
zones and DMA mask.
I know this just spreads the arm code, but I still kinda hate it.

MAX_DMA_ADDRESS is such an oddly defined concepts.  We have the mm
code that uses it to start allocating after the dma zones, but
I think that would better be done using a function returning
1 << max(zone_dma_bits, 32) or so.  Then we have about a handful
of drivers using it that all seem rather bogus, and one of which
I think are usable on arm64.

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Thread (27 messages) 27 messages, 6 authors, last reply 2019-09-02
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