Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC 257774, 256760, 262916, 262905, 262918, 262919, 262920, 262921, 262924,
262925, 262929, 262932, 262935, 262940, 262941, 262942, 262948, 262949,
262950

Strip arm/conf/DEFAULTS down to just items that are mandatory for running
the architecture.

Move all the files named foo/common.c to foo/foo_common.c

Initial cut for DTS on the hl201 board.

Add commented out dts for sam9260ek as well as early printf support.

Make clock optional on uart nodes, then back it out ("I don't know what I
was thinking, but it is lame.")

Set the baud rate if it isn't 0

Make at91_soc_id() public.

Properly round at91 resource on unmapping.

Move AT91 AIC related stuff to own file.

Fix another bug in multicast filtering. i.MX uses 6 bits from MSB in
LE CRC32 for the hash value, not the lowest 6 bits in BE CRC32.

Follow r262916 with one more config file that references a renamed common.c

Remove bogus AT91 define that causes compile errors. Most of the defines
for SAM9X are going away soonish anyway (once FDT works), but until
then...

Remove all dregs of a per-thread undefined-exception-mode stack.

Rework the VFP code that handles demand-based save and restore of state.

Always call vfp_discard() on thread death.

When a thread begins life it doesn't own the VFP hardware state on any cpu.

Make undefined exception entry MP-safe.

MFC r257199, r257200, r257217:

Remove all #include <machine/pmap.h> from arm code. It's already
included by vm/pmap.h, which is a prerequisite for arm/machine/pmap.h
so there's no reason to ever include it directly.

Remove #include <machine/frame.h> from all the arm code that doesn't
really need it. That would be almost everywhere it was included. Add
it in a couple files that really do need it and were previously getting
it by accident via another header.

Remove the last dregs of trapframe_t. It turns out only arm was using
this type, so remove it to make arm code more consistant with other
platforms.

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

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

Rename device vfp to option VFP and retire the ARM_VFP_SUPPORT option. This
simplifies enabling as previously both options were required to be enabled,
now we only need a single option.

While here enable VFP on the PandaBoard.

Remove unused FPE code. This is not enabled anywhere as it is the only
file I can find containing FAST_FPE. It appears this would not work as
want_resched is not defined anywhere.

Merging projects/armv6, part 1

Cummulative patch of changes that are not vendor-specific:
- ARMv6 and ARMv7 architecture support
- ARM SMP support
- VFP/Neon support
- ARM Generic Interrupt Controller driver
- Simplification of startup code for all platforms

Final whitespace trim.

KDB needs <machine/db_machdep.h>, so move it under #ifdef KDB.
While I'm there, remove dead code, we will never support acorn26.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

Rework the PCPU_* (MD) interface:
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
given a specific value.

Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.

Reviewed by: alc, bde
Approved by: jeff (mentor)

style(9) cleanup.

Approved by: cognet

Not only disable/enable interrupts, do it for FIQs as well, when needed.

userret() now only takes 2 parameters.

Close some races between procfs/ptrace and exit(2):
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.

Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week

Merge from p4: minor formatting nits.

1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

Use PCPU_LAZY_INC() for cnt.v_{intr,trap,syscalls} rather than atomic
operations in some places and simple non-per CPU math in others.

Add support for ptrace() and gdb breakpoints.

Start all license statements with /*-

Include <sys/signalvar.h> for trapsignal().

Don't include sys/user.h merely for its side-effect of recursively
including other headers.

Implement breakpoints and single stepping on arm.

Obtained from: NetBSD

Implement enough to be able to enter and leave DDB.

Import FreeBSD/arm kernel bits.
It only supports sa1110 (on simics) right now, but xscale support should come
soon.
Some of the initial work has been provided by :
Stephane Potvin <sepotvin at videotron.ca>
Most of this comes from NetBSD.