xref: /freebsd/sys/vm/vm_object.h (revision e627b39baccd1ec9129690167cf5e6d860509655)
1 /*
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * The Mach Operating System project at Carnegie-Mellon University.
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 the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)vm_object.h	8.3 (Berkeley) 1/12/94
37  *
38  *
39  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40  * All rights reserved.
41  *
42  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
43  *
44  * Permission to use, copy, modify and distribute this software and
45  * its documentation is hereby granted, provided that both the copyright
46  * notice and this permission notice appear in all copies of the
47  * software, derivative works or modified versions, and any portions
48  * thereof, and that both notices appear in supporting documentation.
49  *
50  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
53  *
54  * Carnegie Mellon requests users of this software to return to
55  *
56  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
57  *  School of Computer Science
58  *  Carnegie Mellon University
59  *  Pittsburgh PA 15213-3890
60  *
61  * any improvements or extensions that they make and grant Carnegie the
62  * rights to redistribute these changes.
63  *
64  * $Id: vm_object.h,v 1.30 1996/09/08 20:44:43 dyson Exp $
65  */
66 
67 /*
68  *	Virtual memory object module definitions.
69  */
70 
71 #ifndef	_VM_OBJECT_
72 #define	_VM_OBJECT_
73 
74 #ifdef KERNEL
75 #include <sys/proc.h>		/* XXX for wakeup() */
76 #endif
77 
78 enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE };
79 typedef enum obj_type objtype_t;
80 
81 /*
82  *	Types defined:
83  *
84  *	vm_object_t		Virtual memory object.
85  */
86 
87 struct vm_object {
88 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
89 	TAILQ_ENTRY(vm_object) cached_list; /* list of cached (persistent) objects */
90 	TAILQ_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
91 	TAILQ_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
92 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
93 	objtype_t type;			/* type of pager */
94 	vm_size_t size;			/* Object size */
95 	int ref_count;			/* How many refs?? */
96 	int shadow_count;		/* how many objects that this is a shadow for */
97 	int pg_color;			/* color of first page in obj */
98 	u_short flags;			/* see below */
99 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
100 	u_short	behavior;		/* see below */
101 	int resident_page_count;	/* number of resident pages */
102 	vm_ooffset_t paging_offset;	/* Offset into paging space */
103 	struct vm_object *backing_object; /* object that I'm a shadow of */
104 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
105 	vm_offset_t last_read;		/* last read in object -- detect seq behavior */
106 	vm_page_t page_hint;		/* hint for last looked-up or allocated page */
107 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
108 	void *handle;
109 	union {
110 		struct {
111 			off_t vnp_size; /* Current size of file */
112 		} vnp;
113 		struct {
114 			TAILQ_HEAD(, vm_page) devp_pglist; /* list of pages allocated */
115 		} devp;
116 		struct {
117 			int swp_nblocks;
118 			int swp_allocsize;
119 			struct swblock *swp_blocks;
120 			short swp_poip;
121 		} swp;
122 	} un_pager;
123 };
124 
125 /*
126  * Flags
127  */
128 #define OBJ_CANPERSIST	0x0001		/* allow to persist */
129 #define OBJ_ACTIVE	0x0004		/* active objects */
130 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
131 #define	OBJ_PIPWNT	0x0040		/* paging in progress wanted */
132 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
133 #define	OBJ_MIGHTBEDIRTY	0x0100	/* object might be dirty */
134 #define OBJ_CLEANING	0x0200
135 #define	OBJ_VFS_REF	0x0400		/* object is refed by vfs layer */
136 
137 
138 #define OBJ_NORMAL	0x0		/* default behavior */
139 #define OBJ_SEQUENTIAL	0x1		/* expect sequential accesses */
140 #define OBJ_RANDOM	0x2		/* expect random accesses */
141 
142 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
143 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
144 
145 #ifdef	KERNEL
146 extern int vm_object_cache_max;
147 
148 TAILQ_HEAD(object_q, vm_object);
149 
150 extern struct object_q vm_object_cached_list; /* list of objects persisting */
151 extern int vm_object_cached;		/* size of cached list */
152 
153 extern struct object_q vm_object_list;	/* list of allocated objects */
154 extern long vm_object_count;		/* count of all objects */
155 
156  /* lock for object list and count */
157 
158 extern vm_object_t kernel_object;	/* the single kernel object */
159 extern vm_object_t kmem_object;
160 
161 #endif				/* KERNEL */
162 
163 #ifdef KERNEL
164 static __inline void
165 vm_object_pip_wakeup(vm_object_t object)
166 {
167 	object->paging_in_progress--;
168 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
169 		object->flags &= ~OBJ_PIPWNT;
170 		wakeup(object);
171 	}
172 }
173 
174 vm_object_t vm_object_allocate __P((objtype_t, vm_size_t));
175 void vm_object_cache_clear __P((void));
176 boolean_t vm_object_coalesce __P((vm_object_t, vm_pindex_t, vm_size_t, vm_size_t));
177 void vm_object_collapse __P((vm_object_t));
178 void vm_object_copy __P((vm_object_t, vm_pindex_t, vm_object_t *, vm_pindex_t *, boolean_t *));
179 void vm_object_deallocate __P((vm_object_t));
180 void vm_object_init __P((void));
181 void vm_object_page_clean __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t, boolean_t));
182 void vm_object_page_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
183 void vm_object_pmap_copy __P((vm_object_t, vm_pindex_t, vm_pindex_t));
184 void vm_object_pmap_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t));
185 void vm_object_reference __P((vm_object_t));
186 void vm_object_shadow __P((vm_object_t *, vm_ooffset_t *, vm_size_t));
187 void vm_object_madvise __P((vm_object_t, vm_pindex_t, int, int));
188 #endif				/* KERNEL */
189 
190 #endif				/* _VM_OBJECT_ */
191