xref: /netbsd-src/sys/uvm/uvm_object.h (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*	$NetBSD: uvm_object.h,v 1.31 2011/06/12 03:36:03 rmind Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
28  */
29 
30 #ifndef _UVM_UVM_OBJECT_H_
31 #define _UVM_UVM_OBJECT_H_
32 
33 /*
34  * uvm_object.h
35  */
36 
37 #include <sys/queue.h>
38 #include <sys/rbtree.h>
39 #include <uvm/uvm_pglist.h>
40 
41 /*
42  * uvm_object: all that is left of mach objects.
43  */
44 
45 struct uvm_object {
46 	kmutex_t *		vmobjlock;	/* lock on memq */
47 	const struct uvm_pagerops *pgops;	/* pager ops */
48 	struct pglist		memq;		/* pages in this object */
49 	int			uo_npages;	/* # of pages in memq */
50 	unsigned		uo_refs;	/* reference count */
51 	struct rb_tree		rb_tree;	/* tree of pages */
52 	LIST_HEAD(,ubc_map)	uo_ubc;		/* ubc mappings */
53 };
54 
55 /*
56  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
57  * object is a kernel memory object rather than a normal one (kernel
58  * memory objects don't have reference counts -- they never die).
59  *
60  * this value is used to detected kernel object mappings at uvm_unmap()
61  * time.   normally when an object is unmapped its pages eventaully become
62  * deactivated and then paged out and/or freed.    this is not useful
63  * for kernel objects... when a kernel object is unmapped we always want
64  * to free the resources associated with the mapping.   UVM_OBJ_KERN
65  * allows us to decide which type of unmapping we want to do.
66  */
67 #define UVM_OBJ_KERN		(-2)
68 
69 #define	UVM_OBJ_IS_KERN_OBJECT(uobj)					\
70 	((uobj)->uo_refs == UVM_OBJ_KERN)
71 
72 #ifdef _KERNEL
73 
74 extern const struct uvm_pagerops uvm_vnodeops;
75 extern const struct uvm_pagerops uvm_deviceops;
76 extern const struct uvm_pagerops ubc_pager;
77 extern const struct uvm_pagerops aobj_pager;
78 
79 #define	UVM_OBJ_IS_VNODE(uobj)						\
80 	((uobj)->pgops == &uvm_vnodeops)
81 
82 #define	UVM_OBJ_IS_DEVICE(uobj)						\
83 	((uobj)->pgops == &uvm_deviceops)
84 
85 #define	UVM_OBJ_IS_VTEXT(uobj)						\
86 	(UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj))
87 
88 #define	UVM_OBJ_IS_CLEAN(uobj)						\
89 	(UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj))
90 
91 /*
92  * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification.
93  * (ie. wants to avoid writable user mappings.)
94  *
95  * XXX bad name
96  */
97 
98 #define	UVM_OBJ_NEEDS_WRITEFAULT(uobj)					\
99 	(UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj))
100 
101 #define	UVM_OBJ_IS_AOBJ(uobj)						\
102 	((uobj)->pgops == &aobj_pager)
103 
104 extern const rb_tree_ops_t uvm_page_tree_ops;
105 
106 #endif /* _KERNEL */
107 
108 #endif /* _UVM_UVM_OBJECT_H_ */
109