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Date:   Wed, 13 Jan 2021 12:51:26 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Claire Chang <tientzu@chromium.org>, robh+dt@kernel.org,
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Subject: Re: [RFC PATCH v3 2/6] swiotlb: Add restricted DMA pool
Message-ID: <20210113115126.GB29376@lst.de>
References: <20210106034124.30560-1-tientzu@chromium.org> <20210106034124.30560-3-tientzu@chromium.org> <X/VrqxcaAMi65CF0@kroah.com>
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On Wed, Jan 06, 2021 at 08:50:03AM +0100, Greg KH wrote:
> > --- a/include/linux/device.h
> > +++ b/include/linux/device.h
> > @@ -413,6 +413,7 @@ struct dev_links_info {
> >   * @dma_pools:	Dma pools (if dma'ble device).
> >   * @dma_mem:	Internal for coherent mem override.
> >   * @cma_area:	Contiguous memory area for dma allocations
> > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override.
> 
> Why does this have to be added here?  Shouldn't the platform-specific
> code handle it instead?

The whole code added here is pretty generic.  What we need to eventually
do, though is to add a separate dma_device instead of adding more and more
bloat to struct device.