Remove $FreeBSD$: one-line .c pattern

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

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

cpucontrol: fix extended signature matching code to avoid fallthough

PR: 256502
MFC after: 1 week

cpucontrol(8): De-duplicate common update logic

Every µcode-updater must open the cpucontrol devfs node RDWR, open a
firmware file, validate the FW file has a positive length, mmap it, etc.
De-duplicate that identical logic between every individual platform.

Also, constify references to the readonly-mapped firmware files while here.

Sponsored by: Dell EMC Isilon

cpucontrol: improve Intel microcode revision check

According to the Intel SDM (Volme 3, 9.11.7) the BIOS signature MSR
should be zeroed before executing cpuid (although in practice it does
not seem to matter).

PR: 192487
Submitted by: Dan Lukes
Reported by: Henrique de Moraes Holschuh
MFC after: 3 days

Style. Remove useless return.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Complete r327264 by fixing yet another return without cleanup.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Use proper failure path rather than just returning.

CID: 1199354, 1006894, 1006893, 1006892

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.

Avoid clobbering errno with a call to fprintf

PR: bin/173923
Submitted by: Garrett Cooper <yanegomi@gmail.com>
Approved by: cperciva
MFC After: 3 days

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

Remove dead assignments, we overwrite the variable almost immediately.

Found by: clang static analyzer

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

- Add cpuctl(4) pseudo-device driver to provide access to some low-level
features of CPUs like reading/writing machine-specific registers,
retrieving cpuid data, and updating microcode.
- Add cpucontrol(8) utility, that provides userland access to
the features of cpuctl(4).
- Add subsequent manpages.

The cpuctl(4) device operates as follows. The pseudo-device node cpuctlX
is created for each cpu present in the systems. The pseudo-device minor
number corresponds to the cpu number in the system. The cpuctl(4) pseudo-
device allows a number of ioctl to be preformed, namely RDMSR/WRMSR/CPUID
and UPDATE. The first pair alows the caller to read/write machine-specific
registers from the correspondent CPU. cpuid data could be retrieved using
the CPUID call, and microcode updates are applied via UPDATE.

The permissions are inforced based on the pseudo-device file permissions.
RDMSR/CPUID will be allowed when the caller has read access to the device
node, while WRMSR/UPDATE will be granted only when the node is opened
for writing. There're also a number of priv(9) checks.

The cpucontrol(8) utility is intened to provide userland access to
the cpuctl(4) device features. The utility also allows one to apply
cpu microcode updates.

Currently only Intel and AMD cpus are supported and were tested.

Approved by: kib
Reviewed by: rpaulo, cokane, Peter Jeremy
MFC after: 1 month