Move PowerNow! to the cpufeaturebus.

branches: 1.12.2; 1.12.4;
Remove some unused (ACPI) constants.

Revert all previous changes that were made naively believing that the
existing CPU power management implementations could peacefully coexist with
the acpicpu(4) driver. The following options can not be used with acpicpu(4):
ENHANCED_SPEEDSTEP, INTEL_ONDEMAND_CLOCKMOD, POWERNOW_K7, and POWERNOW_K8.

Add sysctl-glue for interaction with the acpicpu(4).

branches: 1.9.52; 1.9.58; 1.9.60;
* Remove the WRITE_FIDVID macro from powernow.h and use it in in the
powernow_k8 driver (much better than undeffing and write it again).
* Fix the WRITE_FIDVID macro, I changed it to use the third argument
for the bitmask, but it's not correct.

Last change should fix the problem reported by FUKUMOTO Atsushi.

There's no need to run est_init or k8_powernow_init on each CPU.
Just run it once (in the first cpu probed) with the RUN_ONCE(9)
framework.

Change the argument of est_init and k8_powernow_init to void, we don't
need cpu_info * anymore.

Suggested by tls@ and mrg@.

Change k8_powernow_init to accept a struct cpu_info * as argument,
so that in the informative messages it prints the correct cpu
and not curcpu().

This fixes the first part of PR kern/35676.

branches: 1.6.2; 1.6.4; 1.6.6; 1.6.10; 1.6.12; 1.6.14;
Rework the way PowerNow! and Cool'n'Quiet features are detected and
displayed, to make the code much simpler and easier to follow. Also, use
bitmask_printf() to make output consistent with other stuff. Use
CPUID2FAMILY() where appropriate.

branches: 1.5.2; 1.5.4; 1.5.6;
Update powernow module with POWERNOW_K7 and POWERNOW_K8 support.
Works fine on amd64 cpus running in 32-bit mode.

Tested by Joel Carnat.

- Move k7_powernow_* prototypes from i386/include/cpu.h to
x86/include/powernow.h
- Protect k[78]_powernow_init() functions with #ifdef POWERNOW_K[78] to
make it build without these options.

This fixes the problem reported by hubertf.

branches: 1.3.2;
files.x86 isn't included by Xen kernels, so opt_powernow_k8.h never gets
created by config(1), and thus it's not safe to use it in cpuvar.h.

Simply declare the prototype for k8_powernow_init in powernow.h. No need
to #ifdef protect a prototype, after all, only its users.

Un-breaks build of Xen kernels.

branches: 1.2.2;
* Do not change struct powernow_pst_s (I added another member in my
previous patch) and this MUST be of that size, otherwise the tables
won't be found.

* powernow_k8.c moved into x86/x86, it should work both i386 and amd64.

* Added more DPRINTFs needed to found the first problem.

* Create "machdep.powernow.frequency" again, I can't remember why I
removed frequency... it should work with estd now.

* Do not try to call k[78]_powernow_init() if cpu is not AMD (thanks
to christos).

And more things I can't remember, but this time it will work in
Athlon 64 cpus and it won't crash in EM64T cpus.

AMD PowerNow!/Cool`n'Quiet driver for NetBSD/amd64,
adapted from OpenBSD.

Tested on a few machines:

http://bigbird.dohd.org:3021/NetBSD/dmesg
http://www.bsd.org.il/netbsd/acpi/dmesg

Thanks to cube, elad and others for testing and fixes.

Enabled by default on GENERIC.