Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Include machine/acle-compat.h in cdefs.h on arm if the compiler doesn't
have ACLE support built in. The ACLE (ARM C Language Extensions) defines
a set of standardized symbols which indicate the architecture version and
features available. ACLE support is built in to modern compilers (both
clang and gcc), but absent from gcc prior to 4.4.

ARM (the company) provides the acle-compat.h header file to define the
right symbols for older versions of gcc. Basically, acle-compat.h does
for arm about the same thing cdefs.h does for freebsd: defines
standardized macros that work no matter which compiler you use. If ARM
hadn't provided this file we would have ended up with a big #ifdef __arm__
section in cdefs.h with our own compatibility shims.

Remove #include <machine/acle-compat.h> from the zillion other places (an
ever-growing list) that it appears. Since style(9) requires sys/types.h
or sys/param.h early in the include list, and both of those lead to
including cdefs.h, only a couple special cases still need to include
acle-compat.h directly.

Loves it: imp

ARM userspace accessors, e.g. {s,f}uword(9), copy{in,out}(9),
casuword(9) and others, use LDRT and STRT instructions to access
memory with the privileges of userspace. If the *RT instruction
faults on the kernel address, then additional checks must be done to
not confuse the VM system with invalid kernel-mode faults.

Put ARM on line with other FreeBSD architectures and disallow usermode
buffers which intersect with the kernel address space in advance,
before any accesses are performed. In other words, vm_fault(9) is no
longer called when e.g. suword(9) stores to invalid (i.e. not
userspace) address.

Also, switch ARM to use fueword(9) and casueword(9).

Note: there is a pending patch in D3617, which adds the special
processing for faults from LDRT and STRT. The addition of the
processing is useful for potential other uses of the instructions and
for completeness, but standard userspace accessors are better served
by not allowing such faults beforehand.

Reviewed by: andrew
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3816
MFC after: 2 weeks

Fix the spelling of __ARM_ARCH >= 6 in sys/arm/arm.

Remove trailing whitespace from sys/arm/arm

Fix alignment directives in arm asm code after clang 3.5 import.

The ancient gas we've been using interprets .align 0 as align to the
minimum required alignment for the current section. Clang's integrated
assembler interprets it as align to a byte boundary. Fortunately both
assemblers interpret a non-zero value as align to 2^N so just make sure
we have appropriate non-zero values everywhere.

Switch to unified syntax so these can be built with clang 3.5.

MFC after: 1 week
Sponsored by: ABT Systems Ltd

Change the way pcpu and curthread are stored per-core:
the old way was to store pcpu in a register, and get curthread from pcpu,
which is not very atomic, and led to issues if the thread was migrated
to another core between the time we got the pcpu address and the time we
got curthread.
Instead, we now store curthread where pcpu used to be store, and we
calculate the pcpu address based on the cpu id.

Add an END macro to ARM. This is mostly used to tell gas where the bounds
of the functions are when creating the EABI unwind tables.

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

Correctly return EFAULT in copyin & copyout on a fault. This fixes NFS
when running FreeBSD on QEMU emulating a Gumstix board.

While here remove the use of a magic number in the not-XScale version.

Pointed out by: kib
Reviewed by: stas

Final whitespace trim.

In copyout(), quad-align the source buffer, and use ldrd if possible.

Add a new API to let platform-specific ports provide functions for big
copy/zeroing.

Remove kcopy(), we don't use it.

Start all license statements with /*-

Use the RET macro.

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.