Re: [edk2-platforms][PATCH 1/1] Platform/RPi/AcpiTables: Update all tables to latest ACPI

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

On 5/6/20 2:45 PM, Pete Batard wrote:
> On 2020.05.06 13:26, Ard Biesheuvel wrote:
>> On 5/6/20 1:37 PM, Pete Batard wrote:
>> ...
>>> Therefore, since we do see a need for ACPI 6.x features, and
>>> effectively have a 6.3 table with PPTT, and also since we have
>>> tested that we are not seeing ill effects from doing so for the
>>> most common OSes we support, we bring all of the relevant ACPI
>>> tables to version 6.3.
>>>
>>> This is mostly accomplished by simply altering the version of
>>> ACPI being references in the macros,
>>
>> OK, so even the macros that resolve to the exact same code are 
>> renamed. I suppose this means a blanket rename of everything once ACPI 
>> 6.4 comes out?
> 
> No.
> 
> I am considering that we are still in the process of introducing the 
> platform, therefore we introduce it with the most up to date version of 
> ACPI at that time.
> 
> Though I could see some point in doing so, I have no plan to update out 
> ACPI for the Pi's every time a new version is released, unless there is 
> an actual need to do so for a specific table or there is a blanket 
> request (from seeing lots of folks using our code as a starting point) 
> that warrants it.
> 
> In other words, even as RPi3 was introduced a year ago, I consider that 
> we are still in the process of adding RPi3/RPi4 as a brand new platform, 
> and therefore want to use the most up to date ACPI at the time of 
> introduction. But I'm definitely not making a point of trying to follow 
> ACPI updates past that this.
> 

Good.

>>> except for the new fields
>>> being initialized in the MADT table where we:
>>> * Use 1 for GICR Base Address in GICC_STRUCTURE_INIT because, even
>>>    as this field is not supposed to apply to any of our platforms,
>>>    this is what Microsoft used in the original Pi 3 hardcoded MADT
>>>    blobs and Windows 10 doesn't boot on the Pi 3 if set to 0.
>>
>> Fair enough.
>>
>>> * Use 2 for GIC version in GIC_DISTRIBUTOR_INIT, since the Pi 4 GIC
>>>    is v2 only.
>>>
>>
>> OK. But you are introducing new references to ACPI_6_0 macros here. If 
>> the point is to rename everything for cosmetic reasons, shouldn't you 
>> use 6.3 there as well?
> 
> Well, EFI_ACPI_6_0_GIC_DISTRIBUTOR_INIT was not updated for 6_1, 6_2, 
> 6_3 (most likely because the macro, which is defined in 
> EmbeddedPkg/Include/Library/AcpiLib.h applies the same for all 6.x 
> versions), so I just used the highest version I could find, which is 
> 6_0. This is based on what I saw other platforms do.
> 
> I don't mind sending an EDK2 patch to add the various 
> EFI_ACPI_6_x_GIC_DISTRIBUTOR_INIT if that's what you request, but that 
> seems a bit like overkill and may break existing platforms, because it 
> will most likely require moving EFI_ACPI_6_0_GIC_DISTRIBUTOR_INIT to a 
> different header (MdePkg/Include/IndustryStandard/Acpi60.h).
> 

Fair enough.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

Pushed as 66d1b02429fa..11189124fbc2