Messages in this thread | | | Date | Mon, 5 Aug 2019 10:10:52 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH 1/2] dma-mapping: fix page attributes for dma_mmap_* |
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On Mon, Aug 05, 2019 at 11:01:44AM +0300, Christoph Hellwig wrote: > All the way back to introducing dma_common_mmap we've defaulyed to mark
s/defaultyed/defaulted/
> the pages as uncached. But this is wrong for DMA coherent devices. > Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that > flag is only treated special on the alloc side for non-coherent devices. > > Introduce a new dma_pgprot helper that deals with the check for coherent > devices so that only the remapping cases even reach arch_dma_mmap_pgprot
s/even/ever/
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index 1d3f0b5a9940..bd2b039f43a6 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -14,9 +14,7 @@ > pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, > unsigned long attrs) > { > - if (!dev_is_dma_coherent(dev) || (attrs & DMA_ATTR_WRITE_COMBINE)) > - return pgprot_writecombine(prot); > - return prot; > + return pgprot_writecombine(prot); > }
For arm64:
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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