xref: /freebsd/sys/vm/vm_object.h (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
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 1.50 1998/08/06 08:33:19 dfr Exp $
65  */
66 
67 /*
68  *	Virtual memory object module definitions.
69  */
70 
71 #ifndef	_VM_OBJECT_
72 #define	_VM_OBJECT_
73 
74 #include <sys/queue.h>
75 #include <machine/atomic.h>
76 
77 enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_DEAD };
78 typedef enum obj_type objtype_t;
79 
80 /*
81  *	Types defined:
82  *
83  *	vm_object_t		Virtual memory object.
84  */
85 
86 struct vm_object {
87 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
88 	TAILQ_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
89 	TAILQ_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
90 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
91 	int generation;			/* generation ID */
92 	objtype_t type;			/* type of pager */
93 	vm_size_t size;			/* Object size */
94 	int ref_count;			/* How many refs?? */
95 	int shadow_count;		/* how many objects that this is a shadow for */
96 	int pg_color;			/* color of first page in obj */
97 	int	id;					/* ID for no purpose, other than info */
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 	int cache_count;			/* number of cached pages */
103 	int	wire_count;			/* number of wired pages */
104 	vm_ooffset_t paging_offset;	/* Offset into paging space */
105 	struct vm_object *backing_object; /* object that I'm a shadow of */
106 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
107 	vm_offset_t last_read;		/* last read in object -- detect seq behavior */
108 	vm_page_t page_hint;		/* hint for last looked-up or allocated page */
109 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
110 	void *handle;
111 	union {
112 		struct {
113 			off_t vnp_size; /* Current size of file */
114 		} vnp;
115 		struct {
116 			TAILQ_HEAD(, vm_page) devp_pglist; /* list of pages allocated */
117 		} devp;
118 		struct {
119 			int swp_nblocks;
120 			int swp_allocsize;
121 			struct swblock *swp_blocks;
122 			short swp_poip;
123 		} swp;
124 	} un_pager;
125 };
126 
127 /*
128  * Flags
129  */
130 #define OBJ_ACTIVE	0x0004		/* active objects */
131 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
132 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
133 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
134 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
135 #define OBJ_MIGHTBEDIRTY	0x0100	/* object might be dirty */
136 #define OBJ_CLEANING	0x0200
137 #define OBJ_OPT		0x1000		/* I/O optimization */
138 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
139 
140 #define OBJ_NORMAL	0x0		/* default behavior */
141 #define OBJ_SEQUENTIAL	0x1		/* expect sequential accesses */
142 #define OBJ_RANDOM	0x2		/* expect random accesses */
143 
144 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
145 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
146 
147 #ifdef	KERNEL
148 
149 #define	OBJPC_SYNC	0x1			/* sync I/O */
150 #define	OBJPC_INVAL	0x2			/* invalidate */
151 
152 TAILQ_HEAD(object_q, vm_object);
153 
154 extern struct object_q vm_object_list;	/* list of allocated 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 
165 static __inline void
166 vm_object_set_flag(vm_object_t object, u_int bits)
167 {
168 	atomic_set_short(&object->flags, bits);
169 }
170 
171 static __inline void
172 vm_object_clear_flag(vm_object_t object, u_int bits)
173 {
174 	atomic_clear_short(&object->flags, bits);
175 }
176 
177 static __inline void
178 vm_object_pip_add(vm_object_t object, int i)
179 {
180 	atomic_add_short(&object->paging_in_progress, i);
181 }
182 
183 static __inline void
184 vm_object_pip_subtract(vm_object_t object, int i)
185 {
186 	atomic_subtract_short(&object->paging_in_progress, i);
187 }
188 
189 static __inline void
190 vm_object_pip_wakeup(vm_object_t object)
191 {
192 	atomic_subtract_short(&object->paging_in_progress, 1);
193 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
194 		vm_object_clear_flag(object, OBJ_PIPWNT);
195 		wakeup(object);
196 	}
197 }
198 
199 static __inline void
200 vm_object_pip_sleep(vm_object_t object, char *waitid)
201 {
202 	int s;
203 
204 	if (object->paging_in_progress) {
205 		s = splvm();
206 		if (object->paging_in_progress) {
207 			vm_object_set_flag(object, OBJ_PIPWNT);
208 			tsleep(object, PVM, waitid, 0);
209 		}
210 		splx(s);
211 	}
212 }
213 
214 static __inline void
215 vm_object_pip_wait(vm_object_t object, char *waitid)
216 {
217 	while (object->paging_in_progress)
218 		vm_object_pip_sleep(object, waitid);
219 }
220 
221 vm_object_t vm_object_allocate __P((objtype_t, vm_size_t));
222 void _vm_object_allocate __P((objtype_t, vm_size_t, vm_object_t));
223 boolean_t vm_object_coalesce __P((vm_object_t, vm_pindex_t, vm_size_t, vm_size_t));
224 void vm_object_collapse __P((vm_object_t));
225 void vm_object_copy __P((vm_object_t, vm_pindex_t, vm_object_t *, vm_pindex_t *, boolean_t *));
226 void vm_object_deallocate __P((vm_object_t));
227 void vm_object_terminate __P((vm_object_t));
228 void vm_object_vndeallocate __P((vm_object_t));
229 void vm_object_init __P((void));
230 void vm_object_page_clean __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
231 void vm_object_page_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
232 void vm_object_pmap_copy __P((vm_object_t, vm_pindex_t, vm_pindex_t));
233 void vm_object_pmap_copy_1 __P((vm_object_t, vm_pindex_t, vm_pindex_t));
234 void vm_object_pmap_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t));
235 void vm_object_reference __P((vm_object_t));
236 void vm_object_shadow __P((vm_object_t *, vm_ooffset_t *, vm_size_t));
237 void vm_object_madvise __P((vm_object_t, vm_pindex_t, int, int));
238 void vm_object_init2 __P((void));
239 #endif				/* KERNEL */
240 
241 #endif				/* _VM_OBJECT_ */
242