intelhfi - Intel TD/HFI driver - Part1b: Add IA32_PM_ENABLE bit flag define for specialregs.h.

[koinec_yahoo.co.jp]

Summary

To support hmp(4) (https://reviews.freebsd.org/D56547) in the intelhfi driver being developed at https://reviews.freebsd.org/D44456, it became necessary to process the IA32_PM_ENABLE MSR.
Therefore, I will add the definition of the corresponding bit flag.

The following is supplementary information:

• This flag is a separate patch from intelhfi (https://reviews.freebsd.org/D44456). This is because it allows for future support of the hwpstate_intel driver, which currently hardcodes the numerical value.
• Applying this patch is also necessary to build intelhfi (https://reviews.freebsd.org/D44456).

Test Plan

This code utilizes constants defined in intelhfi (https://reviews.freebsd.org/D44456), and I've confirmed that the values ​​can be obtained by this test.

[minsoochoo0122_proton.me]

sys/x86/include/specialreg.h

908

Like above, you can simply use 0x00000001,

[emaste]

sys/x86/include/specialreg.h

908

Values below are of the form (1ULL << x) though and I think it's fine.

From the Intel doc:

HWP_ENABLE (bit 0, R/W1Once) — Software sets this bit to enable HWP with autonomous selection. When set, the processor will disregard input from the legacy performance control interface (IA32_PERF_CTL). Note this bit can only be enabled once from the default value. Once set, writes to the HWP_ENABLE bit are ignored. Only RESET will clear this bit. Default = zero (0).

So if the source doc uses "bit 0" I think (1ULL << 0) is straightforward.

[minsoochoo0122_proton.me]

Makes sense, LGTM.

[emaste]

I'm happy to push this bit definition now and get one item out of the stack. Can you confirm Koine Yuusuke <[e-mail]> for the Git author info?