Re: RFC about how to obtain PCIE TPH steer-tag on ARM64 platform

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jan 14, 2026 at 11:39:27AM +0800, fengchengwen wrote:
> On 1/14/2026 3:07 AM, Bjorn Helgaas wrote:
> > On Mon, Jan 12, 2026 at 11:01:31AM +0800, fengchengwen wrote:
> >> Hi all,
> >>
> >> We want to enable PCIE TPH feature on ARM64 platform, but we encounter the
> >> following problem:
> >>
> >> 1. The pcie_tph_get_cpu_st() function invokes the ACPI DSM method to
> >>    obtain the steer-tag of the CPU. According to the definition of
> >>    the DSM method [1], the cpu_uid should be "ACPI processor uid".
> > 
> >> 2. In the current implementation, the ACPI DSM method is invoked
> >>    directly using the logical core number, which works on the x86
> >>    platform but does not work on the ARM64 platform because the
> >>    logical core ID is not the same as the ACPI processor ID when the
> >>    PG exists.
> > 
> > PG?
> 
> partial good

I still don't know what "partial good" means :)  Is that something
from a spec?