Re: [PATCH V10 4/5] arm64: apei: implement arch_apei_get_mem_attributes()

["Zhang, Jonathan Zhixiong" <zjzhang@codeaurora.org>]

On 8/8/2015 1:11 AM, Ard Biesheuvel wrote:
> On 7 August 2015 at 20:57, Matt Fleming <matt@codeblueprint.co.uk> wrote:
>> On Fri, 07 Aug, at 11:16:03AM, Zhang, Jonathan Zhixiong wrote:
>>>
>>> On some (future) arm64 platforms, APEI/GHES region may have full
>>> coherent access by platform. In such case, the APEI/GHES region have
>>> the same memory attributes as the rest of system RAM, such region
>>> do not need to be advised by UEFI as separate entry, but as part of
>>> system RAM memory region.
>>> That being said, for arm64 platforms that do not have WB capability
>>> for APEI/GHES region, such region should be mapped accordingly.
>>
>> OK, so what I need to know right now is whether I need to drop this
>> entire series from my pull request or whether you can send a patch on
>> top of the existing ones in the EFI 'next' branch to address the mapping
>> heuristic in arch_apei_get_mem_attributes().
>>
>>>>> Jonathan, can you please provide the EFI memory map region attributes
>>>>> for the GHES region that requires this series?
>>> [Reserved           |   |  |  |  |   |  |  |  |UC]
>>
>> Assuming this memmap entry is indicative of most GHES region on arm64
>> right now, I think it's worth taking this patch as-is and addressing the
>> issue Ard raised as a separate patch.
>>
>> Does that work?
>>
>
> I think that is fine.
>
> So we'll expect two patches on top of Matt's -next branch:
> - one that removes the redundant __pgprot
> - one that inverts the order in which the memory attributes are tested
>
> It would be good to have these in the same release so that the
> behavior does not change between releases.
I have above mentioned two changes ready to go. I will send V11 of the
patch set out in the next hour.
>
> Thanks,
> Ard.
>

-- 
Jonathan (Zhixiong) Zhang
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
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