CVS commit: [netbsd-11] src/sys/arch/x86/x86

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Thu Oct  8 18:36:23 UTC 2026

Modified Files:
        src/sys/arch/x86/x86 [netbsd-11]: tsc.c

Log Message:
Pull up following revision(s) (requested by andvar in ticket #509):

        sys/arch/x86/x86/tsc.c: revision 1.65
        sys/arch/x86/x86/tsc.c: revision 1.66
        sys/arch/x86/x86/tsc.c: revision 1.67

Add Centaur cpuid and family 7 to check whether the TSC counter is invariant.

Recent Zhaoxin CPUs have an invariant TSC and advertise that through
CPUID 80000007, as Intel and AMD do.

Allows choosing the TSC timecounter as more reliable than HPET.

Use lfence to serialize rdtsc for VIA Nano and up,  same as Linux do.

Unlike Linux I didn't add a 64-bit guard on assumption that it should work
the same way and the 64-bit version will likely be the preferred one by users.
planning to pull up to netbsd-11, netbsd-10.

Use hex for consistency with the rest of the checks.


To generate a diff of this commit:
cvs rdiff -u -r1.63.2.1 -r1.63.2.2 src/sys/arch/x86/x86/tsc.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.