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Re: [PATCH v5 2/7] dma: Add simple dma_noop_mmap

From Vladimir Murzin <vladimir.murzin@arm.com>
Newsgroups linux.kernel
Subject Re: [PATCH v5 2/7] dma: Add simple dma_noop_mmap
Date 2017-06-22 14:50 +0200
Message-ID <tV9IB-4Lr-13@gated-at.bofh.it> (permalink)
References <tKBIe-15d-7@gated-at.bofh.it> <tKCkV-1Ap-5@gated-at.bofh.it> <tUroe-Jj-23@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On 20/06/17 14:23, Christoph Hellwig wrote:
> On Wed, May 24, 2017 at 11:24:27AM +0100, Vladimir Murzin wrote:
>> This patch adds a simple implementation of mmap to dma_noop_ops.
> 
> Currently we use dma_common_mmap as the generic fallback if a dma_ops
> instance doesn't implement a mmap method.  Can you just fix up
> dma_common_mmap for your nommu case - it looks like yours is basically
> a subset.

dma_common_map() is guarded with CONFIG_MMU and I'm not dare to change that
since I have no idea 1) why it was done 2) how it affects other arches :(

> 
> In fact I suspect yours should call dma_mmap_from_coherent as well,
> so the only different is the lack of pgprot_noncached call.
> 

OK, I'll add a call to dma_mmap_from_coherent().

Cheers
Vladimir

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Thread

Re: [PATCH v5 2/7] dma: Add simple dma_noop_mmap Christoph Hellwig <hch@infradead.org> - 2017-06-20 15:30 +0200
  Re: [PATCH v5 2/7] dma: Add simple dma_noop_mmap Vladimir Murzin <vladimir.murzin@arm.com> - 2017-06-22 14:50 +0200
    Re: [PATCH v5 2/7] dma: Add simple dma_noop_mmap Christoph Hellwig <hch@infradead.org> - 2017-06-26 11:50 +0200

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