MFC r324066:
Use C99 initializers for DTrace provider methods.

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

Add initial DTrace support for RISC-V.

Sponsored by: DARPA, AFRL
Sponsored by: HEIF5

Allow the artificial profile frames to be adjusted as needed by the user.
While here update for armv6 to a tested value.

Submitted by: Howard Su <howard0su@gmail.com>
Reviewed by: stat
Differential Revision: https://reviews.freebsd.org/D4315

First cut of DTrace for AArch64.

Reviewed by: andrew, emaste
Sponsored by: ARM Limited
Differential Revision: https://reviews.freebsd.org/D2738

CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks

Adjust PROF_ARTIFICIAL_FRAMES in the DTrace profile provider on ARM to
skip 10, rather than 9, frames. This appears to work quite well in
practice on the BeagleBone Black, so remove a comment about the value
being bogus and replace it with a slightly less negative one. However,
the number of frames to skip is quite sensitive to details of the timer
and interrupt handling paths, so this is necessarily fragile -- but no
more so than on x86.

Sponsored by: DARPA, AFRL

Replace the completely arbitrary '3' with '9' for the number of frames to
skip using the DTrace 'profile' provider on ARM. This causes stack traces
to skip various driver-and callout-related things as they do on x86, where
the likewise arbitrary values are '6' (32-bit) and '10' (64-bit) for
similar sorts of reasons.

MFC after: 3 days
Sponsored by: DARPA, AFRL

Initial version of DTrace on ARM32.

Submitted by: Howard Su based on work by Oleksandr Tymoshenko
Reviewed by: ian, andrew, rpaulo, markj

remove opensolaris cyclic code, replace with high-precision callouts

In the old days callout(9) had 1 tick precision and that was inadequate
for some uses, e.g. DTrace profile module, so we had to emulate cyclic
API and behavior. Now we can directly use callout(9) in the very few
places where cyclic was used.

Differential Revision: https://reviews.freebsd.org/D1161
Reviewed by: gnn, jhb, markj
MFC after: 2 weeks

Implement DTrace for PowerPC. This includes both 32-bit and 64-bit.

There is one known issue: Some probes will display an error message along the
lines of: "Invalid address (0)"

I tested this with both a simple dtrace probe and dtruss on a few different
binaries on 32-bit. I only compiled 64-bit, did not run it, but I don't expect
problems without the modules loaded. Volunteers are welcome.

MFC after: 1 month

Add device part of DTrace/MIPS code

Custom DTrace kernel module files plus FreeBSD-specific DTrace providers.