Added vm_[un]wire_page(), which are essentially versions of

[un]lock_memory_etc() optimized for a single page.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36156 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/vm/VMArea.h

@@ -43,6 +43,10 @@ struct VMAreaWiredRange : SinglyLinkedListLinkImpl<VMAreaWiredRange> {
 	bool					implicit;	// range created automatically
 	VMAreaUnwiredWaiterList	waiters;
 
+	VMAreaWiredRange()
+	{
+	}
+
 	VMAreaWiredRange(addr_t base, size_t size, bool writable, bool implicit)
 		:
 		area(NULL),
@@ -53,6 +57,15 @@ struct VMAreaWiredRange : SinglyLinkedListLinkImpl<VMAreaWiredRange> {
 	{
 	}
 
+	void SetTo(addr_t base, size_t size, bool writable, bool implicit)
+	{
+		this->area = NULL;
+		this->base = base;
+		this->size = size;
+		this->writable = writable;
+		this->implicit = implicit;
+	}
+
 	bool IntersectsWith(addr_t base, size_t size) const
 	{
 		return this->base + this->size - 1 >= base
@@ -63,6 +76,16 @@ struct VMAreaWiredRange : SinglyLinkedListLinkImpl<VMAreaWiredRange> {
 typedef SinglyLinkedList<VMAreaWiredRange> VMAreaWiredRangeList;
 
 
+struct VMPageWiringInfo {
+	VMAreaWiredRange	range;
+	addr_t				physicalAddress;
+							// the actual physical address corresponding to
+							// the virtual address passed to vm_wire_page()
+							// (i.e. with in-page offset)
+	vm_page*			page;
+};
+
+
 struct VMArea {
 	char*					name;
 	area_id					id;

headers/private/kernel/vm/vm.h

@@ -24,6 +24,7 @@ struct VMArea;
 struct VMCache;
 struct vm_page;
 struct vnode;
+struct VMPageWiringInfo;
 
 
 // area creation flags
@@ -113,6 +114,9 @@ void vm_clear_map_flags(struct vm_page *page, uint32 flags);
 void vm_remove_all_page_mappings(struct vm_page *page);
 int32 vm_clear_page_mapping_accessed_flags(struct vm_page *page);
 int32 vm_remove_all_page_mappings_if_unaccessed(struct vm_page *page);
+status_t vm_wire_page(team_id team, addr_t address, bool writable,
+			struct VMPageWiringInfo* info);
+void vm_unwire_page(struct VMPageWiringInfo* info);
 
 status_t vm_get_physical_page(addr_t paddr, addr_t* vaddr, void** _handle);
 status_t vm_put_physical_page(addr_t vaddr, void* handle);