acpicpu: Add support for ACPI P-states and T-states on Arm.

Add comment.

Convert to use cpufreq(9).

Get rid of RUN_ONCE(9). Should fix PR # kern/44043.

Contrary to the previous, use aprint_error(9) but suppress warnings
caused by the (optional) BIOS-based dynamic voltage and frequency scaling.

Change some printfs to aprint_debug(9).

Maintain the state properly during firmware-based DVFS.

Like in rest of the acpi(4) stack, queue all resume hooks.

Properly set the frequency during suspend and resume. Should fix problems
introduced in the revision 1.42. Pointed out by Taylor C. Campbell.

Add __cpu_simple_lock_t. Use it, x86_read_psl(), and x86_disable_intr() to
disable interrupts locally and protect the access to APERF and MPERF. Also
rationalize the MD initialization sequence.

Move also the evcnt(9) event counters to one place. No functional change.

Simplify by moving the debug printfs to one place. No functional change.

Move the xcall(9) that does the P- and T-state transformations from the MD
layer to the main code. Makes the caches coherent and provides consistent
vmstat(1) output. This is still not quite right, g

Move the xcall(9) that does the P- and T-state transformations from the MD
layer to the main code. Makes the caches coherent and provides consistent
vmstat(1) output. This is still not quite right, given that most of the
cross-calls are typically unnecessary with the dependency coordination.

show more ...

Move acpicpu(4) from "acpinodebus" to "cpufeaturebus".

Start to derive the percpu(9) (or per-domain) state coordination
mechanisms by parsing the _CSD, _PSD, and _TSD objects by default.

Add preliminary support for the IA32_APERF and IA32_MPERF frequency counters.
These are not yet used for anything and only Intel is supported at the moment.

Lower the worst-case latency in P- and T-state transitions to 1 usec.
The previous 10 usec was based on the Intel's Core family. It may have been
improved since that. Also provide an arbitrary upper

Lower the worst-case latency in P- and T-state transitions to 1 usec.
The previous 10 usec was based on the Intel's Core family. It may have been
improved since that. Also provide an arbitrary upper bound for BIOS bugs.

show more ...

Improve error reporting.

Change the default behavior to enforce the maximum frequency when the
firmware requests to do so. This cures severe overhating (> 120 C) observed
on many laptops, being also on par with the specifica

Change the default behavior to enforce the maximum frequency when the
firmware requests to do so. This cures severe overhating (> 120 C) observed
on many laptops, being also on par with the specification(s). This can be
reverted by using the new "hw.acpi.cpu.dynamic" sysctl variable.

show more ...

Use branch annotations in couple of places. Add two comments.

Only override data from XPSS if the conventional _PSS did not contain the
required information. Problem found and diagnosed by jakllsch@; on some AMD
systems vendors fill _PSS correctly, but do not d

Only override data from XPSS if the conventional _PSS did not contain the
required information. Problem found and diagnosed by jakllsch@; on some AMD
systems vendors fill _PSS correctly, but do not duplicate the data in XPSS.

show more ...

- don't clobber the data found by _PSS if XPSS validation fails
- XPSS spec says that Status{,Mask} and Control{,Mask} buffers are 8 bytes
- use ACPI_GET64 macros instead of memcpy when reading from

- don't clobber the data found by _PSS if XPSS validation fails
- XPSS spec says that Status{,Mask} and Control{,Mask} buffers are 8 bytes
- use ACPI_GET64 macros instead of memcpy when reading from buffers

This makes acpicpu work again on my VIA C7-M, whose firmware reports
malformed XPSS packages but has a working _PSS

show more ...

Give a hint about a driver conflict.

Check the cached value also when setting a state.

Use the idea from cegger@ and fill the (X)PSS structure during initialization.