Remove useless zeroing of RTAX_DST on error.
Cleanup a bit.

MFC after:	1 month
Fix the gpio-specifier decoding by respecting the GPIO controller's
#gpio-cells property.

Add a new ofw_bus method (OFW_BUS_MAP_GPIOS()) that allows the GPIO
controller to implement its own mapping to deal with gpio-specifiers,
allowing the decoding of gpio-specifiers to be controller specific.

The default ofw_bus_map_gpios() decodes the linux standard (#gpio-cells =
<2>) and the FreeBSD standard (#gpio-cells = <3>).

It pass the gpio-specifier flag field to the children as an ivar variable so
they can act upon.
Revert r258678.  Make the led gpio-specifier match again the #gpio-cells
settings from the GPIO controller, which i had broken in r258678.  Restore
the active-low flag.
Report boot method (BIOS/UEFI) via sysctl machdep.bootmethod

Sponsored by:	The FreeBSD Foundation
Setting the IMOD value below 0x3F8 can cause IRQ lockups in the Intel
LynxPoint USB 3.0 controllers found in MacBookPro 2013's.

MFC after:	2 days
Tested by:	Huang Wen Hui <huanghwh@gmail.com>
Finish connecting up installer UEFI support. If the kernel was booted using
EFI, set up the disks for an EFI system. If booted from BIOS/CSM, set up
for BIOS.
loader's GPT support on BIOS does not seem to like the root filesystem
being the last filesystem on the disk for some reason when made by this
script. Add a vestigial swap partition to allow this to boot with QEMU
BIOS.
Turn off the full witness trace on console output.

On head/, or more specifically, when WITNESS is in
the kernel config, the console is spammed excessively
with lock order reversal between isofs and devfs.

Set debug.witness.trace=0 in the installer sysctl.conf
to avoid printing the full KDB stack backtrace.  This
does not prevent printing the lock order reversal has
happened, only lessens the console spam.

Sponsored by:	The FreeBSD Foundation
Improve memory allocation model for rt_msg2() rtsock messages:
 * memory is now allocated as early as possible, without holding locks.
 * sysctl users are now guaranteed to get a response (M_WAITOK buffer prealloc).
 * socket users are more likely to use on-stack buffer for replies.
 * standard kernel malloc/free functions are now used instead of radix wrappers.
rt_msg2() has been renamed to rtsock_msg_buffer().

MFC after:	1 month
Remove cpu_idcache_wbinv_all() from kdb_cpu_trap(), it's no longer needed.

This was added ca. 2004 for the purpose of ensuring the caches were in the
right state after the debugger set a breakpoint.  kdb_cpu_sync_icache()
was added in 2007 to handle that situation, and now the wbinv_all is
actually harmful because the operation isn't broadcast to other cores.
There is no difference between IPI_STOP and IPI_STOP_HARD on ARM, so
map them both to the same interrupt number like other arches do.
Flush and invalidate caches on each CPU as part of handling IPI_STOP.

Flushing the caches is required before doing a panic dump, but ARM
doesn't provide a flavor of flush that gets broadcast to other cores.
However, all cores except one are stopped before doing a dump, so this
works around the lack of a global flush/invalidate by doing it locally
on each CPU as part of stopping.

Discussed with:	cognet@
Explain why wbinv_all is SMP-safe in this case, and add a missing l2 cache
flush.  (Either it was missing here, or it isn't needed in the minidump
case.  Adding it here seems like the safer path to consistancy.)
No EFI on i386. This unbreaks the i386 VT kernel build.
Fix build

Found by:	ian
Pointyhat to:	me
Disable the beastie menu for EFI console which doesn't support ANSI codes
(so things like `at-xy', `clear', and other commands don't work making it
impossible to generate a living menu).

Reviewed by:	nwhitehorn, emaste
Do a read-after-write to ensure the interrupt register update is flushed
to the hardware.

The QCA HAL has a comment noting that if this isn't done, modifications
to AR_IMR_S2 before AR_IMR is flushed may produce spurious interrupts.

Obtained from:	QCA
Fix the AR_SLEEP1 and AR_SLEEP2 definitions. Oops!

Tested:

* AR9285, STA
* AR5416, STA

Obtained from:	QCA, Linux ath9k
Program the AR_TSFOOR_THRESHOLD register with a default lifted from
the QCA HAL.

This fires off an interrupt if the TSF from the AP / IBSS peer is
wildly out of range.  I'll add some code to the ath(4) driver soon
which makes use of this.

TODO:

* verify this didn't break TDMA!
* Add a new capability which returns whether the hardware supports
  the MYBEACON RX filter (only receive beacons which match the BSSID)
  or all beacons on the current channel.

* Add the relevant RX filter entry for MYBEACON.

Tested:

* AR5416, STA
* AR9285, STA

TODO:

* once the code is in -HEAD, just make sure that the code which uses it
  correctly sets BEACON for pre-AR5416 chips.

Obtained from:	QCA, Linux ath9k