sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

arm: Only include sysreg.h when needed in asm.h

We only need sysreg.h for armv6 barriers

Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D41141

Retire broken GPROF support from the kernel

The option is not even recognized and with that patched it does not
compile. Even if it did work, it would be prohibitively expensive to
use.

Interested parties can use pmcstat or dtrace instead.

Remove Arm barriers for pre-armv6 CPUs

Remove the macros that define the Arm barriers on Armv5 and earlier. We
don't support these CPUs.

Reviewed by: imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33807

Remove old arm CPU macros

The _ARM_ARCH_* and _HAVE_ARMv*_INSTRUCTIONS macros are FreeBSD
specific. Remove them as they are unused in the base system.

Reviewed by: imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33806

arm: clean up empty lines in .c and .h files

Also check if __ARM_ARCH_6KZ__ is defined when detecting when to use ARMv6
instructions. There is some code that still uses the _ARM_ARCH_* macros.

Sponsored by: DARPA, AFRL

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Add the early hypervisor code needed on 32-bit ARMv7. This will be used
when we bring in bhyve support.

Submitted by: Mihai Carabas <mihai.carabas AT gmail.com>
Differential Revision: https://reviews.freebsd.org/D10045

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

Don't repeat the the word 'the'

(one manual change to fix grammar)

Confirmed With: db
Approved by: secteam (not really, but this is a comment typo fix)

ARM: Remove trailing whitespace from sys/arm/include
No functional changes.

Approved by: kib (mentor)

Add missing stack unwind information to several assembly functions on
ARMv6/7:

- Define _SAVE() macro to allow unwind data to be conditionally defined for
ARM assembly code in the kernel.

- Use _SAVE() to provide unwind information for bcopy_page(), and two (of
many) instances of copyin() and copyout().

Reviewed by: andrew, imp
MFC after: 3 days
Sponsored by: University of Cambridge

We only support the ARM EABI in head, remove the check on __ARM_EABI__.

Mark thumb entry points as such when building for thumb, otherwise mark
them as arm.

Use the Thumb compliant version of the add instruction. We can only use
"add Rd, Rn, Rm" from within an IT (if-then) block.

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.

Define a WFI macro that expands to the right form of wait-for-interrupt
depending on the architecture.

Include acle-compat.h directly (we use its symbols) rather than getting
it via sysreg.h.

Add macros for asm barrier instructions with arch-specific implementations.

Create 'L' variants of all the ENTRY macros for file-static/local symbols.

If it seems like this is getting out of hand, I quite agree. I wonder if
it's safe, here in the 21st century, to lose the distinction between C and
ASM symbols?

Fix the GLOBAL macro so it works (upper vs lowercase X), use it in _EENTRY.

Stylish changes... put tabs where they need to be in macros, move lines
around so that related things are more grouped together, rewrite comments.

No functional changes, this is all so that the functional changes in the
next commit will stand out.

Remove _PROF_PROLOGUE from the EENTRY() macros. These macros define
'extra' entry points which are nested within or provide a synonym name
for another function. It's most likely not safe to be messing with the
IP and LR registers at anything other than the primary entry point to a
function. Anywhere beyond initial function entry, those registers may
be in use as scratch or variable registers.

Pull in the NetBSD global offset table handling code. Clang 3.5 creates
relocations the linker complains about.

Obtained from: NetBSD
MFC after: 1 Week

Update _ENTRY to use _EENTRY to reduce the common code.

Revert r274772: it is not valid on MIPS

Reported by: sbruno

Use canonical __PIC__ flag

It is automatically set when -fPIC is passed to the compiler.

Reviewed by: dim, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1179

Unify interrupts bit definition and usage. While here remove PSR_C_bit.

Submitted by: Svatopluk Kraus <onwahe at gmail.com>,
Michal Meloun <meloun at miracle.cz>
Differential Revision: https://reviews.freebsd.org/D754

Add more register values to armreg.h and remove CPU_CONTROL_32BP_ENABLE
from asm.h as they were already defined in armreg.h.

Submitted by: Michal Meloun <meloun at miracle.cz>

Do not generate unwind info in asm functions if _STANDALONE is defined.
The .fnend op causes the assembler to emit RELOC references to unwind
support functions that don't exist in libstand.

Fix unwind-info errors in our hand-written arm assembler code.

We have functions nested within functions, and places where we start a
function then never end it, we just jump to the middle of something else.
We tried to express this with nested ENTRY()/END() macros (which result
in .fnstart and .fnend directives), but it turns out there's no way to
express that nesting in ARM EHABI unwind info, and newer tools treat
multiple .fnstart directives without an intervening .fnend as an error.

These changes introduce two new macros, EENTRY() and EEND(). EENTRY()
creates a global label you can call/jump to just like ENTRY(), but it
doesn't emit a .fnstart. EEND() is a no-op that just documents the
conceptual endpoint that matches up with the same-named EENTRY().

This is based on patches submitted by Stepan Dyatkovskiy, but I made some
changes and added the EEND() stuff, so blame any problems on me.

Submitted by: Stepan Dyatkovskiy <stpworld@narod.ru>

Reduce the difference to NetBSD.

* Stop pretending we support anything other than ELF by removing code
surrounded by #ifdef __ELF__ ... #endif.
* Remove _JB_MAGIC_SETJMP and _JB_MAGIC__SETJMP, they are defined in
setjmp.h, which is able to be included from asm.
* Fix the spelling of dependent.
* Rename END _END and add END and ASEND to complement ENTRY and ASENTRY
respectively
* Add macros to simplify accessing the Global Offset Table, some of these
will be used in the upcoming update to the setjmp functions.

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

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Define _ARM_ARCH_5E too, so that we know if pld/strd/ldrd are available.

MFC After: 3 days

Use __mcount() instead of _mcount() to reduce diffs with NetBSD.

Remove dead code, already defined in sys/cdef.h

Spotted out by: bde

Start all license statements with /*-

Import a RET macro, that will use bx if the arch supports it.

Obtained from: NetBSD

We are using _mcount, not __mcount.
Remove the !__ELF__ case.

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.