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Date:   Tue, 9 Apr 2019 19:23:09 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Robin Murphy <robin.murphy@arm.com>
Cc:     Christoph Hellwig <hch@lst.de>, Joerg Roedel <joro@8bytes.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        iommu@lists.linux-foundation.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/21] dma-iommu: move the arm64 wrappers to common code
Message-ID: <20190409172309.GD14679@lst.de>
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On Tue, Apr 09, 2019 at 04:07:02PM +0100, Robin Murphy wrote:
>> -static inline int iommu_dma_init(void)
>> +static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
>> +		u64 size, const struct iommu_ops *ops)
>>   {
>> -	return 0;
>>   }
>
> I don't think it makes sense to have a stub for that - AFAICS it should 
> only ever be called form arch code with an inherent "select IOMMU_DMA" 
> (much like the stuff which isn't stubbed currently).
>
> Otherwise, I'm about 97% sure the rest of the move looks OK - thanks for 
> splitting things up.

arm64 only selects IOMMU_DMA if IOMMU_SUPPORT is selected, which can
be disabled.  So to keep some (unusual) arm64 configs compiling we'll need
the stub..