when the bit 22 is set to 1, CPUID with EAX=0 returns a maximum
value in EAX[7..0] of 3, when set to 0(default), CPUID with EAX=0
returns the number corresponding to the maximum standard function
supported. On my machine, BIOS sets the bit to 1 to make it to be
compatible with old OS, this causes dual-core Pentium-D (two
physical cores) to be identified as hyperthreading (two logical
cores) by function mp_topology().
- Add newer CPUID definitions for future use.
Many thanks to Mike Tancsa <mike at sentex dot net> for providing test
cases for Intel Pentium D and AMD Athlon 64 X2.
Approved by: anholt (mentor)
CPU_ENABLE_TCC enables Thermal Control Circuitry (TCC) found in some
Pentium(tm) 4 and (possibly) later CPUs. When enabled and detected,
TCC allows to restrict power consumption by using machdep.cpuperf*
sysctls. This operates independently of SpeedStep and is useful on
systems where other mechanisms such as apm(4) or acpi(4) don't work.
Given the fact that many, even modern, notebooks don't work properly
with Intel ACPI, this is indeed very useful option for notebook owners.
Obtained from: OpenBSD
MFC after: 2 weeks
we are required to do if we let user processes use the extra 128 bit
registers etc.
This is the base part of the diff I got from:
http://www.issei.org/issei/FreeBSD/sse.html
I believe this is by: Mr. SUZUKI Issei <issei@issei.org>
SMP support apparently by: Takekazu KATO <kato@chino.it.okayama-u.ac.jp>
Test code by: NAKAMURA Kazushi <kaz@kobe1995.net>, see
http://kobe1995.net/~kaz/FreeBSD/SSE.en.html
I have fixed a couple of style(9) deviations. I have some followup
commits to fix a couple of non-style things.
the OS does FXSAVE/FXRESTOR instructions (fast FPU save/restore) during
context switching and also enables SIMD since this enables saving the
extra CPU context that isn't saved with normal FPU regs. The other
enables the SIMD instructions to use exception 16 (FPU) error reporting.
Note, this doesn't turn on SIMD, just defines the bits.
The code was originaly contributed by Kelly Yancey
<kbyanc@freedomnet.com> in PR i386/6269 and revised by Akio Morita
<amorita@meadow.scphys.kyoto-u.ac.jp> and me. Test was performed by
Akio Morita and Toshiomi Moriki <moriki@db.is.kyushu-u.ac.jp>.
- Fix stylistic bug in identcpu.c.
- Update copyright in initcpu.c
- Fix typo in LINT.
PR: 6269 and 6270
supports All Cyrix CPUs, IBM Blue Lightning CPU and NexGen (now AMD)
Nx586 CPU, and initialize special registers of Cyrix CPU and msr of
IBM Blue Lightning CPU.
If revision of Cyrix 6x86 CPU < 2.7, CPU cache is enabled in
write-through mode. This can be disabled by kernel configuration
options.
Reviewed by: Bruce Evans <bde@freebsd.org> and
Jordan K. Hubbard <jkh@freebsd.org>
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
negation whenever we access memory between 640k and 1M.
Original code from NetBSD 1.0-BETA. The exact origins are unclear but
Theo de Raadt, Charles, and Michael V. may have contributed to it.
Submitted by: pst
