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

1 files changed, 2 insertions, 0 deletions

diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index 4b21e55..48ba743 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -295,6 +295,8 @@ void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
 void vm_object_split(vm_map_entry_t);
 boolean_t vm_object_sync(vm_object_t, vm_ooffset_t, vm_size_t, boolean_t,
     boolean_t);
+void vm_object_unwire(vm_object_t object, vm_ooffset_t offset,
+    vm_size_t length, uint8_t queue);
 #endif				/* _KERNEL */
 
 #endif				/* _VM_OBJECT_ */