Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

Fix a use-after-free.

Submitted by: Ilja van Sprundel <ilja -at- netric.org>
Reviewed by: secteam
MFC after: 1 day

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

Struct ifatm isn't at the beginning of the softc anymore. Use the
correct way (IFP2IFATM()) to access it.

Approved by: re

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

Split the chip-specific code from the generic Utopia code. This simplifies
adding of new physical chips. Now one just needs to add a .h and a .c
file for the new chip and add one line to utopia.c for that chip.

Start each of the license/copyright comments with /*-, minor shuffle of lines

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

Add missing <sys/module.h> includes

kthread_exit() no longer requires Giant, so don't force callers to acquire
Giant just to call kthread_exit().

Requested by: many

Generate events when the carrier goes up or down.

Add two sysctl's that allow read-only access to the current
state of the utopia interface and to the carrier state.

Implement statistics for the PHY chips. Statistics are hold in
64-bit counters that wrap on overflow. They are collecte once per
second from the chips. Currently they can be retrieved via a sysctl phy_stats.
A write of an arbitrary value to the sysctl atomically retrieves the
statistics and clears them.

Add support for the IDT77155 Sonet/SDH PHY.

This is a driver for the physical layer chips used in ATM interfaces.
It currently supports the PMC Sierra Lite, Ultra and 622 chips and
the IDT 77105. The driver handles media options and state in a consistent
manner for ATM drivers. The next commit to the midway driver will make
it use utopia.