Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Fix a leak of the wired pages when unwiring of the PROT_NONE-mapped
wired region. Rework the handling of unwire to do the it in batch,
both at pmap and object level.

All commits below are by alc.

MFC r268327:
Introduce pmap_unwire().

MFC r268591:
Implement pmap_unwire() for powerpc.

MFC r268776:
Implement pmap_unwire() for arm.

MFC r268806:
pmap_unwire(9) man page.

MFC r269134:
When unwiring a region of an address space, do not assume that the
underlying physical pages are mapped by the pmap. This fixes a leak
of the wired pages on the unwiring of the region mapped with no access
allowed.

MFC r269339:
In the implementation of the new function pmap_unwire(), the call to
MOEA64_PVO_TO_PTE() must be performed before any changes are made to the
PVO. Otherwise, MOEA64_PVO_TO_PTE() will panic.

MFC r269365:
Correct a long-standing problem in moea{,64}_pvo_enter() that was revealed
by the combination of r268591 and r269134: When we attempt to add the
wired attribute to an existing mapping, moea{,64}_pvo_enter() do nothing.
(They only set the wired attribute on newly created mappings.)

MFC r269433:
Handle wiring failures in vm_map_wire() with the new functions
pmap_unwire() and vm_object_unwire().
Retire vm_fault_{un,}wire(), since they are no longer used.

MFC r269438:
Rewrite a loop in vm_map_wire() so that gcc doesn't think that the variable
"rv" is uninitialized.

MFC r269485:
Retire pmap_change_wiring().

Reviewed by: alc

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

The function pmap_addr_hint no longer exists. Remove its man page.

Add a cross-reference to the pmap_page_init(9) manual page.

Approved by: re

Fixed the .Os call (missing or wrong).

Slightly improve the markup.

Sort SEE ALSO references (in dictionary order, ignoring case).

Fix another typo.

Fix typo.

Update cross-references.

Add pmap_wired_count() and pmap_resident_count() to the pmap documentation.

Discussed with: peter

Update the pmap(9) documentation to reflect the movement of pmap_prefault()
to the machine-independent VM layer, as per alc's recent commit.
Add a definition for the new pmap_is_prefaultable() helper function.

Add manual page documentation for the machine-independent PMAP subsystem.
Include documentation of alc's new pmap_extract_and_hold() function.

Reviewed by: hmp
Approved by: jake (mentor)