Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

- Hook into the existing stat timer to drive the transmit watchdog instead
of using if_watchdog and if_timer.
- Reorder detach to call ether_ifdetach() before anything else in tl(4)
and wb(4).

Clean out some empty mergeinfo records, presumably by people doing local
cp/mv operations. The full repo-relative URL should be specified for the
source in these cases.

Move pcn driver from sys/pci to sys/dev/pcn.

- Clear the PCN_MISC_ASEL bit so the media port can be actually set
via the PCN_CSR_MODE register. Along with sys/dev/mii/nsphy.c 1.26
this fixes the case of certain Am79c971-based HP cards and on-board
ones in IBM machines reporting link but not actually passing any
traffic. [1]
- Add support for the internal 10baseT PHY, which actually is used on
at least said HP cards (together with an external DP83840A in a
multiple PHYs configuration). With cards that don't make use of this
internal PHY it'll also show up in FreeBSD but not cause any harm.
This is still missing support for multiple PHYs configuration using
the internal 100baseTX and/or HomePNA PHYs together with external
PHYs or multiple external PHYs though.
- In pcn_ifmedia_upd() call pcn_reset() as otherwise the Am79C971 of
at least said HP cards can wedge when switching from the internal
10baseT PHY to the external PHY. This means that we need to also
initialize and possibly start the chip again in pcn_ifmedia_upd(),
which isn't that bad though as for setting the media port the chip
has to be powered down or stopped anyway and unlike documented
doesn't take effect until the next initialization.

PR: 27995, 25959, 72966 (likely) [1]
MFC after: 2 weeks

- Don't bother to include IDs of PCnet chips which are not supported
by this driver and largely are not even PCI devices in pcn_chipid.
- Use device_printf(9)/if_printf(9) rather than implementing their
functionality with printf(9).
- Sprinkle some const.

Remove various bits of conditional Alpha code and fixup a few comments.

Fix up the locking in pcn(4) and mark it MPSAFE.
- Add locked versions of the init() and start() methods.
- Use callout_*() rather than timeout().
- Make the driver lock non-recursive.
- Push down locking in detach() and ioctl().
- Fix the tick routine to bail if the interface has been stopped and use
callout_drain() in detach() after the call to stop().
- Lock the driver lock in the ifmedia handlers.

Tested by: Ketrien I. Saihr-Kesenchedra ketrien at error404.nls.net
MFC after: 1 week

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

/* -> /*- for license, minor formatting changes

Additional register definitions.

Obtained from: NetBSD

Drop the driver lock around calls to if_input to avoid a LOR when
the packets are immediately returned for sending (e.g. when bridging
or packet forwarding). There are more efficient ways to do this
but for now use the least intrusive approach.

Reviewed by: imp, rwatson

Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

Update the probe some more to deal with 16/32 bit issues. If the chip
is already in 32-bit mode, we need to be able to detect this and still
read the chip ID code. Detecting 32-bit mode is actually a little
tricky, since we want to avoid turning it on accidentally. The easiest
way to do it is to just try and read the PCI subsystem ID from the
bus control registers using 16-bit accesses and compare that with the
value read from PCI config space. If they match, then we know we're in
16-bit mode, otherwise we assume 32-bit mode.

First round of converting network drivers from spls to mutexes. This
takes care of all the 10/100 and gigE PCI drivers that I've done.
Next will be the wireless drivers, then the USB ones. I may pick up
some stragglers along the way. I'm sort of playing this by ear: if
anyone spots any places where I've screwed up horribly, please let me
know.

Add the card ID for the Am79c975 PCnet/FAST III card. This is a variant
of the Am79c973 with "AlertIT Technology," whatever that is. Also mention
support for the PCnet/FAST III cards in the documentation. The
PCnet/FAST III chips have integrated 10/100 PHYs.

Add support for the AMD Am79c976 PCnet/PRO controller chip. For now
this just involves adding the chip ID to the supported list: the PCnet/PRO
is compatible with the PCnet/FAST+ and friends and should "just work"
with this driver.

Also try to handle mbuf allocation failures in the receive handler
more gracefully.

Make pcn_miibus_readreg() latch onto the first PHY that it finds (as
a result of mii_phy_probe()) and use that rather than hardcoding a
constant. The hardcoded way was too specific to the particular card
I had and caused PHY probing to fail on at least one laptop with a
built-in AMD chip.

Reported by: rjk@grauel.com (Richard J Kuhns)

Add a new driver for the AMD PCnet/FAST, FAST+ and Home PCI adapters.
Previously, these cards were supported by the lnc driver (and they
still are, but the pcn driver will claim them first), which is fine
except the lnc driver runs them in 16-bit LANCE compatibility mode.
The pcn driver runs these chips in 32-bit mode and uses the RX alignment
feature to achieve zero-copy receive. (Which puts it in the same
class as the xl, fxp and tl chipsets.) This driver is also MI, so it
will work on the x86 and alpha platforms. (The lnc driver is still
needed to support non-PCI cards. At some point, I'll need to newbusify
it so that it too will me MI.)

The Am79c978 HomePNA adapter is also supported.