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)
place the LOCKing macros within the areas within if_wxvar.h that
is set aside for them. Put any platform specific data also in those
areas.
For ease of maintenance purposes, merge in the OpenBSD version codebase here.
before adding/removing packets from the queue. Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.
IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue. An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.
Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.
driver seems relatively functional, but could use some souping up,
particularly in the performance area. This has both NetBSD and FreeBSD
attachment code and a fair amount of effort has been put into making
it easy to port to different *BSD platforms.
The basic design is a one tfd per mbuf transmit (with no transmit
related interrupts- tfds are gc'd as needed). The receive ring
uses a 2K buffer per rfd with a +2 byte adjust for the ethernet
header (so the payload is aligned). There's support that *almost*
works for doing large packets- the rfd chaining code works, but there's
some problem with getting good checksums at the IP reassembly level
(ditto for doing short tfd's too).
The chip has support for TCP checksums insertion for transmit and
TCP checksum calculation on receive (for both you have to do some
appropriate backoff && twiddling), but this isn't in place.
This is nearly entirely reverse engineered from the released Intel
driver, so there's a lot of "We have to do this but do not know why"
stuff. There is somebody who has the chip specs who works in FreeBSD
but they're being a bit standoffish about even sharing hints which
is somewhat annoying. It's also apparent that all I had to work with
were the first rev boards.
This driver has been lightly tested on intel && alpha, but only
point-to-point. There may be some issues with switches- use of
boot time environment variables that override EEPROM settings
(e.g., 'set wx_ilos=1' which inverts the sense of optical signal
loss) may help with this.
I had this out for review for three weeks, and nobody said anything
negative or positive, ergo, this checkin has no 'reviewed by' field
which I would have preferred.
