Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Use our nitems() macro when param.h is available.

Replacements specific to arm, mips, pc98, powerpc and sparc64.

Discussed in: freebsd-current

ARM: Use new ARMv6 naming conventions for cache and TLB functions
in all but ARMv4 specific files.
Expand ARMv6 compatibility stubs in cpu-v4.h. Use physical address
in L2 cache functions if ARM_L2_PIPT is defined.

Use kernel_pmap directly instead of pmap_kernel(). The kernel_pmap is
already used for __ARM_ARCH >= 6 and so even for __ARM_ARCH < 6 on some
common places.

Print curpmap in "show pcpu" command.

Approved by: kib (mentor)

Add support for branch instruction on armv7 with ptrace single step

Previous code supported only "continuous" code without any kind of
branch instructions. To change that, new function was implemented
which parses current instruction and returns an addres where
the jump might happen (alternative addr).
mdthread structure was extended to support two breakpoints
(one directly below current instruction and the second placed
at the alternative location).
One of them must trigger regardless the instruction has or has not been
executed due to condition field.
Upon cleanup, both software breakpoints are removed.

This implementation parses only the most common instructions
that are present in the code (like 99.99% of all), but there
is a chance there are some left, not covered by the parsing routine.
Parsing is done only for 32-bit instruction, no Thumb nor Thumb-2
support is provided.

Reviewed by: kib
Submitted by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: Juniper Networks Inc.
Differential Revision: https://reviews.freebsd.org/D4021

Remove trailing whitespace from sys/arm/arm

Final whitespace trim.

Add "add pc, whatever" as a branch instruction, we use it in memcpy().

MFC after: 3 days

Handle ldr pc, [reg] in branch_taken().

Obtained from: NetBSD
MFC after: 3 days

Remove unused header file <machine/katelib.h>

style(9) cleanup.

Implement db_frame() and use it to obtain the registers value.

Approved by: re (blanket)

Start all license statements with /*-

Implement breakpoints and single stepping on arm.

Obtained from: NetBSD

Update to kdb.

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.