xref: /netbsd-src/sys/uvm/uvm_object.h (revision 4817a0b0b8fe9612e8ebe21a9bf2d97b95038a97)
1 /*	$NetBSD: uvm_object.h,v 1.29 2010/11/06 12:19:14 uebayasi Exp $	*/
2 
3 /*
4  *
5  * Copyright (c) 1997 Charles D. Cranor and Washington University.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Charles D. Cranor and
19  *      Washington University.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
35  */
36 
37 #ifndef _UVM_UVM_OBJECT_H_
38 #define _UVM_UVM_OBJECT_H_
39 
40 /*
41  * uvm_object.h
42  */
43 
44 #include <sys/rbtree.h>
45 #include <uvm/uvm_pglist.h>
46 
47 /*
48  * uvm_object: all that is left of mach objects.
49  */
50 
51 struct uvm_object {
52 	kmutex_t		vmobjlock;	/* lock on memq */
53 	const struct uvm_pagerops *pgops;	/* pager ops */
54 	struct pglist		memq;		/* pages in this object */
55 	int			uo_npages;	/* # of pages in memq */
56 	unsigned		uo_refs;	/* reference count */
57 	struct rb_tree		rb_tree;	/* tree of pages */
58 };
59 
60 /*
61  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
62  * object is a kernel memory object rather than a normal one (kernel
63  * memory objects don't have reference counts -- they never die).
64  *
65  * this value is used to detected kernel object mappings at uvm_unmap()
66  * time.   normally when an object is unmapped its pages eventaully become
67  * deactivated and then paged out and/or freed.    this is not useful
68  * for kernel objects... when a kernel object is unmapped we always want
69  * to free the resources associated with the mapping.   UVM_OBJ_KERN
70  * allows us to decide which type of unmapping we want to do.
71  */
72 #define UVM_OBJ_KERN		(-2)
73 
74 #define	UVM_OBJ_IS_KERN_OBJECT(uobj)					\
75 	((uobj)->uo_refs == UVM_OBJ_KERN)
76 
77 #ifdef _KERNEL
78 
79 extern const struct uvm_pagerops uvm_vnodeops;
80 extern const struct uvm_pagerops uvm_deviceops;
81 extern const struct uvm_pagerops ubc_pager;
82 extern const struct uvm_pagerops aobj_pager;
83 
84 #define	UVM_OBJ_IS_VNODE(uobj)						\
85 	((uobj)->pgops == &uvm_vnodeops)
86 
87 #define	UVM_OBJ_IS_DEVICE(uobj)						\
88 	((uobj)->pgops == &uvm_deviceops)
89 
90 #define	UVM_OBJ_IS_VTEXT(uobj)						\
91 	(UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj))
92 
93 #define	UVM_OBJ_IS_CLEAN(uobj)						\
94 	(UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj))
95 
96 /*
97  * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification.
98  * (ie. wants to avoid writable user mappings.)
99  *
100  * XXX bad name
101  */
102 
103 #define	UVM_OBJ_NEEDS_WRITEFAULT(uobj)					\
104 	(UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj))
105 
106 #define	UVM_OBJ_IS_AOBJ(uobj)						\
107 	((uobj)->pgops == &aobj_pager)
108 
109 extern const rb_tree_ops_t uvm_page_tree_ops;
110 
111 #define	UVM_OBJ_INIT(uobj, ops, refs)					\
112 	do {								\
113 		mutex_init(&(uobj)->vmobjlock, MUTEX_DEFAULT, IPL_NONE);\
114 		(uobj)->pgops = (ops);					\
115 		TAILQ_INIT(&(uobj)->memq);				\
116 		(uobj)->uo_npages = 0;					\
117 		(uobj)->uo_refs = (refs);				\
118 		rb_tree_init(&(uobj)->rb_tree, &uvm_page_tree_ops);	\
119 	} while (/* CONSTCOND */ 0)
120 
121 #ifdef DIAGNOSTIC
122 #define	UVM_OBJ_DESTROY(uobj)						\
123 	do {								\
124 		voff_t _xo = 0;						\
125 		void *_xn;						\
126 		mutex_destroy(&(uobj)->vmobjlock);			\
127 		_xn = rb_tree_find_node_geq(&(uobj)->rb_tree, &_xo);	\
128 		KASSERT(_xn == NULL);					\
129 	} while (/* CONSTCOND */ 0)
130 #else
131 #define	UVM_OBJ_DESTROY(uobj)						\
132 	do {								\
133 		mutex_destroy(&(uobj)->vmobjlock);			\
134 	} while (/* CONSTCOND */ 0)
135 #endif	/* DIAGNOSTIC */
136 
137 #endif /* _KERNEL */
138 
139 #endif /* _UVM_UVM_OBJECT_H_ */
140