[PATCH v8 0/2] ommu/exynos: Add IOMMU/System MMU driver for Samsung Exynos

KyongHo Cho pullip.cho at samsung.com
Fri Feb 24 11:08:36 EST 2012


Hi Marek.

On Fri, Feb 24, 2012 at 10:45 PM, Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
> Hi,
>
> On Thursday, December 29, 2011 1:24 PM KyongHo Cho wrote:
>
>> Changes since v7:
>> - Rebased with the recent commits of the following git branches
>>   * git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/next
>>   * git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung.git/for-next
>> - Changed magic numbers into macros
>> - Setting owner of a System MMU in 'iommu' field of dev_archdata
>> - Verbose message in the default fault handler
>> - Some bug fixes.
>
> (snipped)
>
> The time is flying away and v3.4 merge windows will open soon. Do you plan to
> send an updated version of the SYSMMU driver anytime soon? It will be really
> nice to have it finally merged to v3.4.
>

Thank you for asking.

I prepared a new patchset and it is ready for submitting.
It includes several bugfixes and Exynos5 support.

The last patche submitted has a bug when the following situation:
   1. Allocating a 2nd level page table to map 4KB or 64KB on a virtual region
   2. Unmapped all entries in the 2nd level page table.
   3. Mapping to the same region with 1MB page.
   Then iommu_map() will return -EADDRINUSE due to incorrect counting
   free entries in 2nd level page table.

The next patch will be submitted by 2/28.

BTW Marek, I want to know why MFC driver defines separate platform devices
for left and right buses.
The next IOMMU driver defines just one platform device for a H/W device.
Thus, it defines just one SYSMMU_MFC platform device, for example.
(the previous one defines 2 platform devices for SYSMMU_MFC)
However, it is easy to separate the single platform device to multiple
platform devices.

Regards,

Cho KyongHo.



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