sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

[PowerPC] [MIPS] Implement 32-bit kernel emulation of atomic64 operations

This is a lock-based emulation of 64-bit atomics for kernel use, split off
from an earlier patch by jhibbits.

This is needed to unblock future improvements that reduce the need for
locking on 64-bit platforms by using atomic updates.

The implementation allows for future integration with userland atomic64,
but as that implies going through sysarch for every use, the current
status quo of userland doing its own locking may be for the best.

Submitted by: jhibbits (original patch), kevans (mips bits)
Reviewed by: jhibbits, jeff, kevans
Differential Revision: https://reviews.freebsd.org/D22976

emulate illumos membar_producer with atomic_thread_fence_rel

membar_producer is supposed to be a store-store barrier.
Also, in the code that FreeBSD has ported from illumos membar_producer
is used only with regular stores to regular memory (with respect to
caching).

We do not have an MI primitive for the store-store barrier, so
atomic_thread_fence_rel is the closest we have as it provides
(load | store) -> store barrier.

Previously, membar_producer was an empty function call on all 32-bit
arm-s, 32-bit powerpc, riscv and all mips variants. I think that it was
inadequate.
On other platforms, such as amd64, arm64, i386, powerpc64, sparc64,
membar_producer was implemented using stronger primitives than required
for a store-store barrier with respect to regular memory access.
For example, it used sfence on amd64 and lock-ed nop in i386 (despite TSO).
On powerpc64 we now use recommended lwsync instead of eieio.
On sparc64 FreeBSD uses TSO mode.
On arm64/aarch64 we now use dmb sy instead of dmb ish. Not sure if this
is an improvement, actually.

After this change we can drop opensolaris_atomic.S for aarch64, amd64,
powerpc64 and sparc64 as all required atomic operations have either
direct or light-weight mapping to FreeBSD native atomic operations.

Discussed with: kib
MFC after: 4 weeks

cleanup of illumos compatibility atomics

atomic_cas_32 is implemented using atomic_fcmpset_32 on all platforms.
Ditto for atomic_cas_64 and atomic_fcmpset_64 on platforms that have it.
The only exception is sparc64 that provides MD atomic_cas_32 and
atomic_cas_64.
This is slightly inefficient as fcmpset reports whether the operation
updated the target and that information is not needed for cas.
Nevertheless, there is less code to maintain and to add for new platforms.
Also, the operations are done inline now as opposed to function calls before.

atomic_add_64_nv is implemented using atomic_fetchadd_64 on platforms
that provide it.

casptr, cas32, atomic_or_8, atomic_or_8_nv are completely removed as they
have no users.

atomic_mtx that is used to emulate 64-bit atomics on platforms that lack
them is defined only on those platforms.

As a result, platform specific opensolaris_atomic.S files have lost most of
their code. The only exception is i386 where the compat+contrib code
provides 64-bit atomics for userland use. That code assumes availability of
cmpxchg8b instruction. FreeBSD does not have that assumption for i386
userland and does not provide 64-bit atomics. Hopefully, this can and will
be fixed.

MFC after: 3 weeks

ZFS: add emulation of atomic_swap_64 and atomic_load_64

Some 32-bit platforms do not provide 64-bit atomic operations that ZFS
requires, either in userland or at all. We emulate those operations for
those platforms using a mutex. That is not entirely correct and it's
very efficient. Besides, the loads are plain loads, so torn values are
possible.

Nevertheless, the emulation seems to work for some definition of work.

This change adds atomic_swap_64, which is already used in ZFS code, and
atomic_load_64 that can be used to prevent torn reads.

MFC after: 1 week

Fix 32-bit buildworld for i386 after r334320.

The 64-bit atomics defined for i386 are currently only available in
the kernel space.

Found by: cy@
MFC after: 1 week
Sponsored by: Mellanox Technologies

Implement atomic_add_64() and atomic_subtract_64() for the i386 target.

While at it add missing _acq_ and _rel_ variants for 64-bit atomic
operations under i386.

Reviewed by: kib @
MFC after: 1 week
Sponsored by: Mellanox Technologies

When arm 64-bit atomic ops are available, define ARM_HAVE_ATOMIC64. Use
that symbol (which will be correct in both kernel and userland contexts)
rather than just __arm__ to decide whether to use a local implementation.

Finally... Import the latest open-source ZFS version - (SPA) 28.

Few new things available from now on:

- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
transaction group.
- Possibility to import pool in read-only mode.

MFC after: 1 month

CDDL fixes for MIPS n32.

Provide 64 bit atomic ops, and use 32 bit pointer.

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

Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.

This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

Allows regular users to perform ZFS operations, like file system
creation, snapshot creation, etc.

- L2ARC

Level 2 cache for ZFS - allows to use additional disks for cache.
Huge performance improvements mostly for random read of mostly
static content.

- slog

Allow to use additional disks for ZFS Intent Log to speed up
operations like fsync(2).

- vfs.zfs.super_owner

Allows regular users to perform privileged operations on files stored
on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

Not all the flags are supported. This still needs work.

- ZFSBoot

Support to boot off of ZFS pool. Not finished, AFAIK.

Submitted by: dfr

- Snapshot properties

- New failure modes

Before if write requested failed, system paniced. Now one
can select from one of three failure modes:
- panic - panic on write error
- wait - wait for disk to reappear
- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

Just quota and reservation properties, but don't count space consumed
by children file systems, clones and snapshots.

- Sparse volumes

ZVOLs that don't reserve space in the pool.

- External attributes

Compatible with extattr(2).

- NFSv4-ACLs

Not sure about the status, might not be complete yet.

Submitted by: trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from: OpenSolaris

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

Mips needs the same treatment for atomic_or_8 as the other RISCy
architectures.

- Reduce number of atomic operations needed to be implemented in asm by
implementing some of them using existing ones.
- Allow to compile ZFS on all archs and use atomic operations surrounded
by global mutex on archs we don't have or can't have all atomic
operations needed by ZFS.