Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r314568 (by emaste):

kern_sig.c: ANSIfy and remove archaic register keyword

Sponsored by: The FreeBSD Foundation

MFC r318389 (by emaste):

Remove register keyword from sys/ and ANSIfy prototypes

A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by: cem, jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10193

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r324660:

Save VFP state in getcontext(3) on ARM. This is a last followup of r315974,
which fixes userland part of VFP save/restore problems described in PR
217611.

MFC r306162:

Make it possible to safely use TPIDRURW from userspace.

On amd64, arm64 and i386, we have the possibility to switch between TLS
areas in userspace. The nice thing about this is that it makes it easier
to do light-weight threading, if we ever feel like doing that. On armv6,
let's go into the same direction by making it possible to safely use the
TPIDRURW register, which is intended for this purpose.

Clean up the ARMv6 code to remove md_tp entirely. Simply add a dedicated
field to the PCB to hold the value of TPIDRURW across context switches,
like we do for any other register. As userspace currently uses the
read-only TPIDRURO register, simply ensure that we keep both values in
sync where possible. The system calls for modifying the read-only
register will simply write the intended value into both registers, so
that it lazily ends up in the PCB during the next context switch.

Approved by: andrew
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D7951

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: Use new ARMv6 naming conventions for cache and TLB functions
in all but ARMv4 specific files.
Expand ARMv6 compatibility stubs in cpu-v4.h. Use physical address
in L2 cache functions if ARM_L2_PIPT is defined.

ARM: Introduce new cpu-v4.h header and move all ARMv4 specific code
from cpu-v6.h to it.
Remove unneeded cpu-v6.h includes.

Stop checking for ARM_TP_ADDRESS when we mean to check if building for
ARMv6 or later.

Better handling of userland sysarch() requests to flush icache.

On armv6, cache maintenance can trigger page faults. Add handling so that
these turn into SIGSEGV that kills the process rather than panics that kill
the kernel.

Differential Revision: https://reviews.freebsd.org/D2035
Submitted by: Michal Meloun <meloun@miracle.cz>

Do not save/restore the TLS pointer on context switch for armv6. The
pointer cannot be changed directly by userland code on armv6 (it can be on
armv4), so there's no need to save/restore.

Submitted by: Michal Meloun

Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

MFC after: 3 weeks

Remove clause 3 (advertising clause), per regent's letter.

Fix panic in ktrcapfail() when no capability rights are passed.
While here, correct all consumers to pass NULL instead of 0 as we pass
capability rights as pointers now, not uint64_t.

Reported by: Daniel Peyrolon
Tested by: Daniel Peyrolon
Approved by: re (marius)

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.

Trace attempts to call restricted MD syscalls.

Add some checks to ensure that Capsicum is behaving correctly, and add some
more explicit comments about what's going on and what future maintainers
need to do when e.g. adding a new operation to a sys_machdep.c.

Approved by: mentor(rwatson), re(bz)

We may split today's CAPABILITIES into CAPABILITY_MODE (which has
to do with global namespaces) and CAPABILITIES (which has to do with
constraining file descriptors). Just in case, and because it's a better
name anyway, let's move CAPABILITIES out of the way.

Also, change opt_capabilities.h to opt_capsicum.h; for now, this will
only hold CAPABILITY_MODE, but it will probably also hold the new
CAPABILITIES (implying constrained file descriptors) in the future.

Approved by: rwatson
Sponsored by: Google UK Ltd

Continue to introduce Capsicum capability mode:

White list sysarch calls allowed in capability mode; arguably, there
should be some link between the capability mode model and the privilege
model here. Sysarch is a morass similar to ioctl, in many senses.

Submitted by: anderson
Discussed with: benl, kris, pjd
Sponsored by: Google, Inc.
Obtained from: Capsicum Project
MFC after: 3 months

Make md_tp a register_t not a void *. This will keep us from
accidentally dereferencng it and might be one fewer things to change
if arm64 happens...

Submitted by: rwatson's question on irc...

style(9) cleanup.

Implement two new sysarch for arm, ARM_GET_TP and ARM_SET_TP, to work around
the lack of tls on arm.

Add MD syscalls to sync the icache and to drain the write buffer.

Obtained from: NetBSD

Remove unused includes.

Spotted out by: pjd

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.