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)

- Remove redundant timecounter masking from counter_get_timecount().
- Zero the timecounter when allocation so we don't need to initialize unused
members and remove a now redundant NULL assignment.

Submitted by: jkim

- Use the name returned by device_get_nameunit(9) for the name of the
counter-timer timecounter so the associated SYSCTL nodes don't clash on
machines having multiple U2P and U2S bridges as well as establishing a
clear mapping between these bridges and their timecounter device.
- Don't bother setting up a "nice" name for the IOMMU, just use the name
returned by device_get_nameunit(9), too.
- Fix some minor style(9) bugs.
- Use __FBSDID in counter.c

MFC after: 1 week

Set the tc_quality field of the struct before calling tc_init(), since
the structure space had been obtained from malloc() its contents is
random garbage. The choice of value being set is part of a larger effort
to solve some timecounter issues on MP machines (while working on that
we noticed this problem).

Noticed by: marius
Reviewed by: marius, green
MFC after: 3 days

Prefer explicit ints to implicit ints in the prototype as well as in
the function definition.

- Fix a typo in a printf(). [1]
- Fix some other style bugs while I'm here.

Submitted by: Koop Mast <kwm@rainbow-runner.nl> [1]
Fixes PR: sparc64/66448 [1]

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

Add support for the counter-timer which is included in the Sun U2S and
U2P bridges as a time counter.