From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Fri, 27 Sep 2013 09:35:24 +0100
Subject: [PATCH 3/9] ARM: dma-mapping: Always pass proper prot flags to
 iommu_map()
In-Reply-To: <1380234982-1677-4-git-send-email-andreas.herrmann@calxeda.com>
References: <1380234982-1677-1-git-send-email-andreas.herrmann@calxeda.com>
 <1380234982-1677-4-git-send-email-andreas.herrmann@calxeda.com>
Message-ID: <20130927083523.GA8319@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, Sep 26, 2013 at 11:36:15PM +0100, Andreas Herrmann wrote:
> ... otherwise it is impossible for the low level iommu driver to
> figure out which pte flags should be used.
> 
> In __map_sg_chunk we can derive the flags from dma_data_direction.
> 
> In __iommu_create_mapping we should treat the memory like
> DMA_BIDIRECTIONAL and pass both IOMMU_READ and IOMMU_WRITE to
> iommu_map.
> __iommu_create_mapping is used during dma_alloc_coherent (via
> arm_iommu_alloc_attrs).  AFAIK dma_alloc_coherent is responsible for
> allocation _and_ mapping.  I think this implies that access to the
> mapped pages should be allowed.
> 
> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda.com>

  Acked-by: Will Deacon <will.deacon@arm.com>

This one should go via the dma-mapping tree.

Will