Change the 'period' argument to 'duration' and change its type to
sbintime_t so we can more easily express different durations.

Reviewed by:	tsoome, glebius
Differential Revision:	https://reviews.freebsd.org/D32619

(cherry picked from commit 072d5b98c4318e20248a6fbea4a5ca7c96992cac)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE.  All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by:	kib (mentor, blanket)
Commented by:	kib, gallatin, melifaro
Differential Revision:	https://reviews.freebsd.org/D23718

Remove all sparc64 specific files
Remove all sparc64 ifdefs
Removee indireeect sparc64 ifdefs

Analysis seems to reveal that sc->keyboard >= 0 implies sc->kbd != NULL and
there's no such scenario where sc->kbd is set (and theoretically used to
rebuild sc->keyboard) with the keyboard unavailable.

Drop the index softc. The index is only explicitly needed in few places, in
which case we can just as easily grab it from sc->kbd. There's no need for
keeping sc->kbd and sc->keyboard in sync when it can be readily accomplished
with just the former.

Reviewed by:	kib, imp
Differential Revision:	https://reviews.freebsd.org/D22752

This was purely automatically massaged... some parts are still imperfect,
but this is close enough to make it more readable/easy to work on.
Unfortunately the vt/syscons/kdb situation slightly complicates changes to
tty locking, so some work will need to be done to remediate that.

Effectively all i386 kernels now have two pmaps compiled in: one
managing PAE pagetables, and another non-PAE. The implementation is
selected at cold time depending on the CPU features. The vm_paddr_t is
always 64bit now. As result, nx bit can be used on all capable CPUs.

Option PAE only affects the bus_addr_t: it is still 32bit for non-PAE
configs, for drivers compatibility. Kernel layout, esp. max kernel
address, low memory PDEs and max user address (same as trampoline
start) are now same for PAE and for non-PAE regardless of the type of
page tables used.

Non-PAE kernel (when using PAE pagetables) can handle physical memory
up to 24G now, larger memory requires re-tuning the KVA consumers and
instead the code caps the maximum at 24G. Unfortunately, a lot of
drivers do not use busdma(9) properly so by default even 4G barrier is
not easy. There are two tunables added: hw.above4g_allow and
hw.above24g_allow, the first one is kept enabled for now to evaluate
the status on HEAD, second is only for dev use.

i386 now creates three freelists if there is any memory above 4G, to
allow proper bounce pages allocation. Also, VM_KMEM_SIZE_SCALE changed
from 3 to 1.

The PAE_TABLES kernel config option is retired.

In collaboarion with: pho
Discussed with:	emaste
Reviewed by:	markj
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18894

given in random(4).

This includes updating of the relevant man pages, and no-longer-used
harvesting parameters.

Ensure that the pseudo-unit-test still does something useful, now also
with the "other" algorithm instead of Yarrow.

PR:		230870
Reviewed by:	cem
Approved by:	so(delphij,gtetlow)
Approved by:	re(marius)
Differential Revision:	https://reviews.freebsd.org/D16898