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)

Note that module should return EOPNOTSUPP for both unrecognized
*and* unsupported values of `what'.

Submitted by: kevlo
Discussed on: cvs-doc@
Approved by: re (hrs)
MFC after: 3 days

Use 'manual page' instead of 'man page' for consistency.

Approved by: re (hrs)

Scheduled mdoc(7) sweep.

Give kldunload a -f(orce) argument.

Add a MOD_QUIESCE event for modules. This should return error (EBUSY)
of the module is in use.

MOD_UNLOAD should now only fail if it is impossible (as opposed to
inconvenient) to unload the module. Valid reasons are memory references
into the module which cannot be tracked down and eliminated.

When kldunloading, we abandon if MOD_UNLOAD fails, and if -force is
not given, MOD_QUIESCE failing will also prevent the unload.

For backwards compatibility, we treat EOPNOTSUPP from MOD_QUIESCE as
success.

Document that modules should return EOPNOTSUPP for unknown events.

mdoc(7) police: removed HISTORY info from the .Os call.

mdoc(7) police: sort SEE ALSO xrefs (sort -b -f +2 -3 +1 -2).

Sort includes and remove bogus typedef of modeventhand_t, since this
isn't used in the example any more.

Pointed out by: bde

- DECLARE_MODULE needs SYSINIT -> include sys/kernel.h
- modeventhand_t declares a pointer to a function, so it can't be
used as a forward declaration (d'oh!)

Submitted by: Harti Brandt <brandt@fokus.gmd.de>

Fix brain damage: s/CDEV_MODULE/DEV_MODULE/

Add calls to MODULE_VERSION and MODULE_DEPEND to the EXAMPLE.

Add a general manpage about kernel modules, similar to driver(9).

Reviewed by: dfr, ru