UFS support of the unmapped i/o for the user data buffers.

Sponsored by:	The FreeBSD Foundation
Tested by:	pho, scottl, jhb, bf
ahci(4) and siis(4) are ready to process the unmapped i/o requests

Sponsored by:	The FreeBSD Foundation
Tested by:	pho
Submitted by:	bf (siis patch)
Add a comment about why aout support is still here: We need it for
compat2x, which is still in use, as evidence by recent bug reports.
Now that the tx map field is correctly populated for both edma and
legacy chips, just use that.
Add more TODO items.
Break out the RX completion path into "FIFO check / refill" and
"complete RX frames."

The 128 entry RX FIFO is really easy to fill up and miss refilling
when it's done in the ath taskq - as that gets blocked up doing
RX completion, TX completion and other random things.

So the 128 entry RX FIFO now gets emptied and refilled in the ath_intr()
task (and it grabs / releases locks, so now ath_intr() can't just be
a FAST handler yet!) but the locks aren't held for very long. The
completion part is done in the ath taskqueue context.

Details:

* Create a new completed frame list - sc->sc_rx_rxlist;
* Split the EDMA RX process queue into two halves - one that
  processes the RX FIFO and refills it with new frames; another
  that completes the completed frame list;
* When tearing down the driver, flush whatever is in the deferred
  queue as well as what's in the FIFO;
* Create two new RX methods - one that processes all RX queues,
  one that processes the given RX queue.  When MSI is implemented,
  we get told which RX queue the interrupt came in on so we can
  specifically schedule that.  (And I can do that with the non-MSI
  path too; I'll figure that out later.)
* Convert the legacy code over to use these new RX methods;
* Replace all the instances of the RX taskqueue enqueue with a call
  to a relevant RX method to enqueue one or all RX queues.

Tested:

* AR9380, STA
* AR9580, STA
* AR5413, STA
Implement SOCK_CLOEXEC, SOCK_NONBLOCK and MSG_CMSG_CLOEXEC.

This change allows creating file descriptors with close-on-exec set in some
situations. SOCK_CLOEXEC and SOCK_NONBLOCK can be OR'ed in socket() and
socketpair()'s type parameter, and MSG_CMSG_CLOEXEC to recvmsg() makes file
descriptors (SCM_RIGHTS) atomically close-on-exec.

The numerical values for SOCK_CLOEXEC and SOCK_NONBLOCK are as in NetBSD.
MSG_CMSG_CLOEXEC is the first free bit for MSG_*.

The SOCK_* flags are not passed to MAC because this may cause incorrect
failures and can be done later via fcntl() anyway. On the other hand, audit
is expected to cope with the new flags.

For MSG_CMSG_CLOEXEC, unp_externalize() is extended to take a flags
argument.

Reviewed by:	kib
Add simple example.
Run zvol_create_minors() on snapshot creation
Run zvol_create_minors() only if in non-error case
Add VNET wrappers around the rest of the ieee80211 rtsock messages.

I triggered the cac/radar messages when doing testing in DFS channels.
For RTL8211B or later PHYs, enable crossover detection and
auto-correction. This change makes re(4) establish a link with
a system using non-crossover UTP cable.

Tested by:	Michael BlackHeart < amdmiek <> gmail dot com >
Fix the EDMA CABQ handling - for now, the CABQ takes a descriptor chain
like the legacy chips expect.
Pull in r177252 from upstream clang trunk:

 Make sure to use same EABI version for external assembler as for
 integrated as.

This allows us to use gcc on a world built with clang on ARM.
Fix the logic inversion in the r248512.

Noted by:	mckay
Release hold on pool before calling zvol_create_minor()
Add ipfw support for setting/matching DiffServ codepoints (DSCP).

Setting DSCP support is done via O_SETDSCP which works for both
IPv4 and IPv6 packets. Fast checksum recalculation (RFC 1624) is done for IPv4.
Dscp can be specified by name (AFXY, CSX, BE, EF), by value
(0..63) or via tablearg.

Matching DSCP is done via another opcode (O_DSCP) which accepts several
classes at once (af11,af22,be). Classes are stored in bitmask (2 u32 words).

Many people made their variants of this patch, the ones I'm aware of are
(in alphabetic order):

Dmitrii Tejblum
Marcelo Araujo
Roman Bogorodskiy (novel)
Sergey Matveichuk (sem)
Sergey Ryabin

PR:		kern/102471, kern/121122
MFC after:	2 weeks
Remove unused variable.
Fix spelling.
Integrate Efika MX project back to home.

Sponsored by:	The FreeBSD Foundation