Some microoptimizations for da and ada drivers:
 - Replace ordered_tag_count counter with single flag;
 - From da remove outstanding_cmds counter, duplicating pending_ccbs list;
 - From da_softc remove unused links field.
interrupt-parent and #interrupt-cells are written to the tree using
encode-int.
Revert r256921 to prevent error output when in the wrong directory.
This should have been reverted with the stable/10/Makefile.inc1
revert, but apparently my commit did not go through.

Discussed with:	cperciva (originally)
Regenerate documentation post r256915:

Stop conflating WITHOUT_CLANG with WITHOUT_CLANG_IS_CC.  This allows
bootstrapping a copy of clang without building clang for the base system
which is useful for nanobsd and similar setups.  It's still probably
wrong to conflate what is installed as /usr/bin/cc with the selection
of a bootstrap compiler under WITH*_CLANG_IS_CC, but that's for another
day.
Allow PIC drivers to translate firmware sense codes for themselves. This
is designed to replace the tables in dev/fdt/fdt_ARCH.c, but will not
happen quite yet.
Do not map IRQs twice. This fixes PowerPC/FDT systems with multiple PICs,
which would try to treat the previously-mapped interrupts from
fdt_decode_intr() as interrupt line numbers on the same parent PIC.
Don't spin with mutex hold when there is not enough room in the send socket
buffer.  While here, make the code flow somewhat nicer.

Thanks to mav@ for tracking it down.

Tested by:	mav
MFC after:	3 days
Sponsored by:	FreeBSD Foundation
Add the Raspberry Pi SPI controller driver.

Reviewed by:	rpaulo
Approved by:	adrian (mentor)
Add an OFW SPI compatible bus.  Fix the spibus probe to return
BUS_PROBE_GENERIC and not BUS_PROBE_SPECIFIC (0) so the OFW SPI bus can
attach when enabled.  Export the spibus devclass_t and driver_t
declarations.

Submitted by:	ray
Approved by:	adrian (mentor)
Fix a use-after-free node reference issue when waiting for a return
from a management frame transmission.

This bug is a bit loopy, so here goes.

The underlying cause is pretty easy to understand - the node isn't
referenced before passing into the callout, so if the node is deleted
before the callout fires, it'll dereference free'd memory.

The code path however is slightly more convoluted.

The functions _say_ mgt_tx - ie management transmit - which is partially
true.  Yes, that callback is attached to the mbuf for some management
frames.  However, it's only for frames relating to scanning and
authentication attempts.  It helpfully drives the VAP state back to
"SCAN" if the transmission fails _OR_ (as I subsequently found out!)
if the transmission succeeds but the state machine doesn't make progress
towards being authenticated and active.

Now, the code itself isn't terribly clear about this.

It _looks_ like it's just handling the transmit failure case.

However, when you look at what goes on in the transmit success case, it's
moving the VAP state back to SCAN if it hasn't changed state since
the time the callback was scheduled.  Ie, if it's in ASSOC or AUTH still,
it'll go back to SCAN.  But if it has transitioned to the RUN state,
the comparison will fail and it'll not transition things back to the
SCAN state.

So, to fix this, I decided to leave everything the way it is and merely
fix the locking and remove the node reference.

The _better_ fix would be to turn this callout into a "assoc/auth request"
timeout callback and make the callout locked, thus eliminating all races.
However, until all the drivers have been fixed so that transmit completions
occur outside of any locking that's going on, it's going to be impossible
to do this without introducing LORs.  So, I leave some of the evilness
in there.

Tested:

* AR5212, ath(4), STA mode
* 5100 and 4965 wifi, iwn(4), STA mode
Move the implementation of bus_space_barrier(9) to the inline function in
the header. Actually, there's only one version for all types of busses, so
it doesn't make sense to walk up the hierarchy.
Correct typo. s/an an/an/
Modernize pass(4) description to the 21st century.

Reviewed by:	mav
Add ddb 'show ioapic' and 'show all ioapics' commands.

Reviewed by:	jhb (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Move the PCI_DMA_BOUNDARY definition into the pcivar.h.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Add some definitions for the bits in root control and status PCIe cap
registers.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Make pci_get_dma_tag() non-static.  Since the function is only
referenced by pointer, making it non-static should not have even the
negligible impact on the existing code.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Remove some of the code required for supporting ssm(4) on SPARC in favor
of a more PowerPC/FDT-focused design. Whenever SPARC64 is integrated
into this rework, this should be (trivially) revisited.
Cleanup empty directories

PR:	conf/167133
Fix panic in the tap driver when a tap and vmnet interface were
created after each other e.g.

 ifconfig tap0
 ifconfig vmnet0
 <panic>

Appears to be a cut'n'paste error from the tap code to the vmnet
code where the name string wasn't updated in the call to make_dev().

Reviewed by:	glebius
MFC after:	3 days