Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

The NetBSD Foundation has granted permission to remove clauses 3 and 4.

Obtained from: NetBSD

Pass the previously returned IRQ back to arm_get_next_irq() so that
the implementation can guarantee forward progress in the event of
a stuck interrupt or interrupt storm. This is especially critical
for fast interrupt handlers, as they can cause a hard hang in that
case. When first called, arm_get_next_irq() is passed -1.

Obtained from: Juniper Networks, Inc.

style(9) cleanup.

Approved by: cognet

Fix multiple abuses of __RMAN_RESOURCE_VISIBLE in the arm code.

Spotted out by: phk

- MFp4: modify slightly the arm intr API, there's arm CPUs with more than 32
interrupts.
- Implement teardown methods where appropriate.

Update the StrongArm port to match the current code.
- Implement arm_mask_irqs and arm_unmask_irqs
- Provide the available physical address range after pmap_bootstrap allocated
things, instead or before, or bad things happen.

Big cleanup: get ride of the whole spl level logic, as FreeBSD doesn't use
it anymore.

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.