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

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

MFC r236991:

Final whitespace trim.

Submitted by: imp
Approved by: marius
Obtained from: Netflix

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

Approved by: re (implicit)

Remove empty dev_mem_md_init() stubs.

Add reader/writer lock around mem_range_attr_get() and mem_range_attr_set().
Compile sys/dev/mem/memutil.c for all supported platforms and remove now
unnecessary dev_mem_md_init(). Consistently define mem_range_softc from
mem.c for all platforms. Add missing #include guards for machine/memdev.h
and sys/memrange.h. Clean up some nearby style(9) nits.

MFC after: 1 month

Update d_mmap() to accept vm_ooffset_t and vm_memattr_t.

This replaces d_mmap() with the d_mmap2() implementation and also
changes the type of offset to vm_ooffset_t.

Purge d_mmap2().

All driver modules will need to be rebuilt since D_VERSION is also
bumped.

Reviewed by: jhb@
MFC after: Not in this lifetime...

Replace all calls to minor() with dev2unit().

After I removed all the unit2minor()/minor2unit() calls from the kernel
yesterday, I realised calling minor() everywhere is quite confusing.
Character devices now only have the ability to store a unit number, not
a minor number. Remove the confusion by using dev2unit() everywhere.

This commit could also be considered as a bug fix. A lot of drivers call
minor(), while they should actually be calling dev2unit(). In -CURRENT
this isn't a problem, but it turns out we never had any problem reports
related to that issue in the past. I suspect not many people connect
more than 256 pieces of the same hardware.

Reviewed by: kib

Make sure the address is valid before mapping it.

MFC after: 1 week

Ooops we need to include <machine/vmparam.h> to get the definition of
KERNBASE and VM_MAXUSER_ADDRESS.
Remove the useless include of opt_global.h, as noticed by netchild@ (the one
in arm/elf_trampoline.c is legit, because this file is compiled outside the
kernel, and doesn't use the standard CFLAGS).

Rewrite ARM_USE_SMALL_ALLOC so that instead of the current behavior, it maps
whole the physical memory, cached, using 1MB section mappings. This reduces
the address space available for user processes a bit, but given the amount of
memory a typical arm machine has, it is not (yet) a big issue.
It then provides a uma_small_alloc() that works as it does for architectures
which have a direct mapping.

Make mem.c know about the pages allocated with ARM_USE_SMALL_ALLOC.

Import md bits for mem(4) on arm.
While I'm there, cleanup a bit pmap.h.