CVS commit: [netbsd-10] src

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

Module Name:    src
Committed By:   martin
Date:           Thu Aug 27 17:11:27 UTC 2026

Modified Files:
        src/sys/arch/x86/x86 [netbsd-10]: identcpu.c
        src/usr.sbin/cpuctl/arch [netbsd-10]: i386.c

Log Message:
Pull up following revision(s) (requested by andvar in ticket #1334):

        sys/arch/x86/x86/identcpu.c: revision 1.142
        usr.sbin/cpuctl/arch/i386.c: revision 1.149

Decode L2 cache associativity for VIA CPUs using the AMD cache lookup table for
the 0x80000006 CPUID function associativity value.

Use `cpuid leaf 4' to get cache parameters for Zhaoxin and late VIA CPU models.

VIA datasheets mention that associativity is stored as a decimal value. However,
in practice, it is encoded the AMD way and does not store the actual value.

Using the raw value leads to an incorrect CPU colors calculation, causing a
panic on KX-7000 (since the result is not a power of two) and incorrect CPU
colors values on other CPU models (e.g. as visible in `vmstat -s').

Decoding value using the AMD cache lookup table produces correct values in all
cases I have tested or verified using CPUID dumps available online.

Additionally, Zhaoxin and late VIA CPUs (CNQ and newer) prefer the Intel
`cpuid leaf 4' function to get cache parameters. Check whether cpuid_level
is equal to or greater than 4 to identify these CPUs and override cache values
(including L1) by calling cpu_dcp_cacheinfo(ci, 4). L3 cache information is
available only through this method.

Fixes PR kern/60619

Similar changes will be committed separately to the cpuctl utility.
Thanks to skrll@ for comments on the patch.

cpuctl(8): decode L2 cache associativity for VIA CPUs using the AMD cache lookup
table for the 0x80000006 CPUID function associativity value.

Use `cpuid leaf 4' to get cache parameters for Zhaoxin and late VIA CPU models.

Mirrors the changes from identcpu.c rev. 1.142.

Additionally, use via_cpu_probe() and via_cpu_cacheinfo() for CPUVENDOR_IDT
family > 6 CPUs to identify Zhaoxin CPUs and their features.
Also, print feature 5-7 bits for CPUVENDOR_IDT, which appear to be compatible
with Intel.

Use vendorname = "Zhaoxin" for family 7 models.

Tested on various 32-bit and 64-bit VIA and Zhaoxin CPUs
(Samuel 2 / Nehemiah, Esther (32-bit), multiple Nano models, and KX-U6580/7000).

PR kern/60619


To generate a diff of this commit:
cvs rdiff -u -r1.123.4.4 -r1.123.4.5 src/sys/arch/x86/x86/identcpu.c
cvs rdiff -u -r1.133.2.4 -r1.133.2.5 src/usr.sbin/cpuctl/arch/i386.c

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