From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Tue, 18 Jun 2013 12:32:44 +0200
Subject: DMA mapping API(IOMMU) for ARM64?
In-Reply-To: <20130618101914.GB3539@mudshark.cambridge.arm.com>
References: <20130618.053955.305832937374936961.hdoyu@nvidia.com>
 <20130618101914.GB3539@mudshark.cambridge.arm.com>
Message-ID: <5159282.rrJMaZuYMv@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tuesday 18 June 2013 11:19:14 Will Deacon wrote:
> 
> I've spoken briefly with Catalin about this and it seems like there might be
> *some* scope for sharing common dma-mapping code between architectures.
> There doesn't really need to be any architecture-specific details in
> allocating iova space and the interface to the iommu drivers is
> well-defined. The arch-specific stuff is bogged down in the non-coherent
> buffer management, but that doesn't necessarily equate to lots of code.
> 
> So, the best bet would be to figure out how to split up what we have under
> arch/arm/ so that it can be re-used by arm64 and potentially other
> architectures (powerpc has some simple stuff for coherent mappings and some
> less-simple stuff for non-coherent buffers).

I'm sure that other architectures are interested in sharing the code.
Best move it into the global mm/ directory, at least the version for
coherent mappings.

	Arnd