On Tue, Jan 28, 2020 at 07:14:18PM +0800, John Garry wrote: > The ACPI PPTT ID structure (see 6.2 spec, section 5.2.29.3) allows the > vendor to provide an identifier (or vendor specific part number) for a > particular processor hierarchy node structure. That may be a processor > identifier for a processor node, or some chip identifier for a processor > package node. > Unfortunately, there were plans to deprecate this in favour of the new SOC_ID SMCCC API[1]. I am not sure if you or anyone in your company have access to UEFI ASWG mantis where you can look for the ECR for the PPTT Type 2 deprecation. I understand it's not ideal, but we need to converge, please take a look at both before further discussion. I personally would not prefer to add the support when I know it is getting deprecated. I am not sure on kernel community policy on the same. [...] > > The ID structure table has a number of fields, which are left open to > interpretation per implementation. However the spec does provide reference > examples of how the fields could be used. As such, just provide the > table fields directly in the API, which the caller may interpret (probably > as per spec example). > The "open for interpretation" part is why it's not being favoured anymore by silicon vendors as OEM/ODMs can override the same. > https://lore.kernel.org/linux-arm-kernel/1579876505-113251-6-git-send-email-john.garry@xxxxxxxxxx/ > Ah, there's already quite a lot of dependency built for this feature :( -- Regards, Sudeep [1] https://developer.arm.com/docs/den0028/c
