Re: [edk2-devel] [PATCH 1/2] Mde Pkg: Support for MPAM ACPI Table

[hesham.almatary@huawei.com]

Hello Rohit,

On 8/24/2022 5:25 PM, Rohit Mathew wrote:
> Hi Hesham,
>
> The idea for keeping it as separate type was to abstract locator field to have a view similar to that of its definition in the spec (MPAM ACPI 1.0, section 2.2, table 7 - Resource node.)
>
> Something of the lines –
>
> typedef struct {
>    UINT32                   Identifier;
>    UINT8                    RisIndex;
>    UINT16                   Reserved1;
>    UINT8                    LocatorType;
>    MPAM_LOCATOR             Locator;
>    UINT32                   NumDependencies;
> } MPAM_MSC_RESOURCE;
>
> Locator field could very well be a struct of UINT64 and UINT32 with just descriptor 1 and descriptor 2 as the field names  (Table 10, 2.3.2)– As you said, having hardcoded field names won’t work as the descriptors change with locator type.
>
>
> ///
>
> /// MPAM MSC Locator field
>
> ///
>
> typedef struct {
>
>    UINT64                   Descriptor1;
>
>    UINT32                   Descriptor2;
>
> } MPAM_LOCATOR;
>
> Let me know your thoughts on the approach.

Thanks for the explanation. It makes sense to me, I don't have a strong bias 
towards not having it as a struct.


> Regards,
> Rohit
>
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of hesham.almatary via groups.io
> Sent: 24 August 2022 15:39
> To: Andrew Fish <afish@apple.com>; devel@edk2.groups.io
> Subject: Re: [edk2-devel] [PATCH 1/2] Mde Pkg: Support for MPAM ACPI Table
>
> Hello Rohit and Swatisri,
>
> On Tue, Aug 23, 2022 at 09:11 PM, Andrew Fish wrote:
> [Rohit ] Shouldn't " Locator " field be 12 bytes in size, possibly a separate type? (MPAM ACPI 1.0, section 2.2, table 7 - Resource node and section 2.3.2 table 10 - locator descriptor)
> I'd just go for UINT64 locator1 and UINT32 locator2 and not necessarily a separate type. The interpretation of each depends on the the locator type (e.g., MPAM ACPI Tables 11-15).
>