uio: Use switch statements when handling UIO_READ vs UIO_WRITE

This is mostly to reduce the diff with CheriBSD which adds additional
constants to enum uio_rw, but also matches the normal style used for
uio_segflg.

Reviewed by: kib, emaste
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D45142

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 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

uiomove: Add some assertions

Make sure that we don't try to copy with a negative resid.

Make sure that we don't walk off the end of the iovec array.

Reviewed by: kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D42098

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

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

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.

Delete stray clause 3 (Advertising clause) and renumber while i'm
here.

Approved by: alc@

Put the general logic for being a CPU hog into a new function
should_yield(). Use this in various places. Encapsulate the common
case of check-and-yield into a new function maybe_yield().

Change several checks for a magic number of iterations to use
should_yield() instead.

MFC after: 1 week

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.

MFi386:
revision 1.6
date: 2004/08/21 18:50:34; author: alc; state: Exp; lines: +3 -1
Properly free the temporary sf_buf in uiomove_fromphys() if a copyin or
copyout fails.

Obtained from: DragonFlyBSD

Spotted out by: Mark Tinguely
MFC After: 3 days

Start all license statements with /*-

Use sf_bufs for uiomove_fromphys().

Remove checks for curthread == NULL - it can't happen.

Move TDF_DEADLKTREAT into td_pflags (and rename it accordingly) to avoid
having to acquire sched_lock when manipulating it in lockmgr(), uiomove(),
and uiomove_fromphys().

Reviewed by: jhb

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.