Re: [PATCH v2 1/2] [RFC] ARM: IOMMU: Tegra20: iommu_ops for GARTdriver

From: Joerg Roedel
Date: Fri Dec 16 2011 - 10:43:46 EST


On Thu, Dec 15, 2011 at 03:11:29PM +0200, Hiroshi DOYU wrote:
> Tegra 20 IOMMU H/W, GART (Graphics Address Relocation Table). This
> patch implements struct iommu_ops for GART for the upper IOMMU API.
>
> This H/W module supports only single virtual address space(domain),
> and manages a single level 1-to-1 mapping H/W translation page table.
>
> Signed-off-by: Hiroshi DOYU <hdoyu@xxxxxxxxxx>
> ---
> drivers/iommu/Kconfig | 11 +
> drivers/iommu/Makefile | 1 +
> drivers/iommu/tegra-gart.c | 451 ++++++++++++++++++++++++++++++++++++++++++++

The code looks good in general. I think we need to extend the IOMMU-API
a little bit to better support GART IOMMUs. A user of the IOMMU-API
should be able to get the information about the iova-base and size of
the aperture for example. These extensions will be beneficial for
porting other GART-like driver to the IOMMU-API too.


Joerg

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