[PATCH 0/5] Qcom smmu-500 TLB invalidation errata for sdm845
vivek.gautam at codeaurora.org
Wed Sep 5 02:22:21 PDT 2018
On 8/14/2018 5:54 PM, Vivek Gautam wrote:
> Hi Will,
> On 8/14/2018 5:10 PM, Will Deacon wrote:
>> Hi Vivek,
>> On Tue, Aug 14, 2018 at 04:25:23PM +0530, Vivek Gautam wrote:
>>> Qcom's implementation of arm,mmu-500 on sdm845 has a
>>> errata  because of which the TCU cache look ups are stalled during
>>> invalidation cycle. This is mitigated by serializing all the
>>> requests coming to the smmu.
>> How does this implementation differ from the one supported by
>> I notice you're adding firmware hooks here, which we avoided by
>> having the
>> extra driver. Please help me understand which devices exist, how they
>> differ, and which drivers are intended to support them!
> IIRC, the qcom_iommu driver was intended to support the static context
> bank - SID
> mapping, and is very specific to the smmu-v2 version present on
> msm8916 soc.
> However, this is the qcom's mmu-500 implementation specific errata.
> will not be able to support mmu-500 configurations.
> Rob Clark can add more.
> Let you know what you suggest.
Rob, can you please comment about how qcom-smmu driver has different
from arm-smmu driver?
Will, in case we would want to use arm-smmu driver, what would you
having the firmware hooks?
>> Also -- you didn't CC all the maintainers for the firmware bits, so
>> Andy here for that, and Rob for the previous question.
> I added Andy to the series, would you want me to add Rob H also?
> Best regards
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