Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

General consensus is that it would be even better to run this in a
thread context. While it doesn't matter too much at the moment, in
the future we could be back in the same boat if/when more restrictions
are placed (or enforced) in a SWI.

Suggested by: njl, bde, jhb, scottl

Use intptr_t casts to convert void * <--> int to make 64-bit archs happy.

Kick off the suspend sequence from the keyboard in a SWI rather than
in the hardware interrupt context (even if it is likely just an
ithread). We don't document that suspend/resume routines are run from
such a context and some of the things that happen in those routines
aren't interrupt safe. Since there's no real need to run from that
context, this restores assumptions that suspend routines have made.

This fixes Thierry Herbelot's 'Trying to sleep while sleeping is
prohibited' problem.

Move the kernel power change printf under bootverbose since the
power_profile script now duplicates the message via syslog.

Use __FBSDID().

Use ISO 9X variadic macro format; arguments are not optional, just
variable.

Add generalized power profile code.
This makes other power-management system (APM for now) to be able to
generate power profile change events (ie. AC-line status changes), and
other kernel components, not only the ACPI components, can be notified
the events.

- move subroutines in acpi_powerprofile.c (removed) to kern/subr_power.c
- call power_profile_set_state() also from APM driver when AC-line
status changes
- add call-back function for Crusoe LongRun controlling on power
profile changes for a example

Some fix for the recent apm module changes.
- Now that apm loadable module can inform its existence to other kernel
components (e.g. i386/isa/clock.c:startrtclock()'s TCS hack).
- Exchange priority of SI_SUB_CPU and SI_SUB_KLD for above purpose.
- Add simple arbitration mechanism for APM vs. ACPI. This prevents
the kernel enables both of them.
- Remove obsolete `#ifdef DEV_APM' related code.
- Add abstracted interface for Powermanagement operations. Public apm(4)
functions, such as apm_suspend(), should be replaced new interfaces.
Currently only power_pm_suspend (successor of apm_suspend) is implemented.

Reviewed by: peter, arch@ and audit@