xref: /freebsd/sys/vm/vm_object.h (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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 1.55 1999/06/19 18:42:52 alc 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 
87 struct vm_object {
88 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
89 	TAILQ_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
90 	TAILQ_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
91 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
92 	int generation;			/* generation ID */
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 	int hash_rand;			/* vm hash table randomizer	*/
99 	u_short flags;			/* see below */
100 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
101 	u_short	behavior;		/* see below */
102 	int resident_page_count;	/* number of resident pages */
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 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
107 	void *handle;
108 	union {
109 		/*
110 		 * VNode pager
111 		 *
112 		 *	vnp_size - current size of file
113 		 */
114 		struct {
115 			off_t vnp_size;
116 		} vnp;
117 
118 		/*
119 		 * Device pager
120 		 *
121 		 *	devp_pglist - list of allocated pages
122 		 */
123 		struct {
124 			TAILQ_HEAD(, vm_page) devp_pglist;
125 		} devp;
126 
127 		/*
128 		 * Swap pager
129 		 *
130 		 *	swp_bcount - number of swap 'swblock' metablocks, each
131 		 *		     contains up to 16 swapblk assignments.
132 		 *		     see vm/swap_pager.h
133 		 */
134 		struct {
135 			int swp_bcount;
136 		} swp;
137 	} un_pager;
138 };
139 
140 /*
141  * Flags
142  */
143 #define OBJ_ACTIVE	0x0004		/* active objects */
144 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
145 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
146 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
147 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
148 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty */
149 #define OBJ_CLEANING	0x0200
150 #define OBJ_OPT		0x1000		/* I/O optimization */
151 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
152 
153 #define OBJ_NORMAL	0x0		/* default behavior */
154 #define OBJ_SEQUENTIAL	0x1		/* expect sequential accesses */
155 #define OBJ_RANDOM	0x2		/* expect random accesses */
156 
157 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
158 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
159 
160 #ifdef	KERNEL
161 
162 #define	OBJPC_SYNC	0x1			/* sync I/O */
163 #define	OBJPC_INVAL	0x2			/* invalidate */
164 
165 TAILQ_HEAD(object_q, vm_object);
166 
167 extern struct object_q vm_object_list;	/* list of allocated objects */
168 
169  /* lock for object list and count */
170 
171 extern vm_object_t kernel_object;	/* the single kernel object */
172 extern vm_object_t kmem_object;
173 
174 #endif				/* KERNEL */
175 
176 #ifdef KERNEL
177 
178 static __inline void
179 vm_object_set_flag(vm_object_t object, u_int bits)
180 {
181 	atomic_set_short(&object->flags, bits);
182 }
183 
184 static __inline void
185 vm_object_clear_flag(vm_object_t object, u_int bits)
186 {
187 	atomic_clear_short(&object->flags, bits);
188 }
189 
190 static __inline void
191 vm_object_pip_add(vm_object_t object, int i)
192 {
193 	atomic_add_short(&object->paging_in_progress, i);
194 }
195 
196 static __inline void
197 vm_object_pip_subtract(vm_object_t object, int i)
198 {
199 	atomic_subtract_short(&object->paging_in_progress, i);
200 }
201 
202 static __inline void
203 vm_object_pip_wakeup(vm_object_t object)
204 {
205 	atomic_subtract_short(&object->paging_in_progress, 1);
206 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
207 		vm_object_clear_flag(object, OBJ_PIPWNT);
208 		wakeup(object);
209 	}
210 }
211 
212 static __inline void
213 vm_object_pip_wakeupn(vm_object_t object, int i)
214 {
215 	if (i)
216 		atomic_subtract_short(&object->paging_in_progress, i);
217 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
218 		vm_object_clear_flag(object, OBJ_PIPWNT);
219 		wakeup(object);
220 	}
221 }
222 
223 static __inline void
224 vm_object_pip_sleep(vm_object_t object, char *waitid)
225 {
226 	if (object->paging_in_progress) {
227 		int s = splvm();
228 		if (object->paging_in_progress) {
229 			vm_object_set_flag(object, OBJ_PIPWNT);
230 			tsleep(object, PVM, waitid, 0);
231 		}
232 		splx(s);
233 	}
234 }
235 
236 static __inline void
237 vm_object_pip_wait(vm_object_t object, char *waitid)
238 {
239 	while (object->paging_in_progress)
240 		vm_object_pip_sleep(object, waitid);
241 }
242 
243 vm_object_t vm_object_allocate __P((objtype_t, vm_size_t));
244 void _vm_object_allocate __P((objtype_t, vm_size_t, vm_object_t));
245 boolean_t vm_object_coalesce __P((vm_object_t, vm_pindex_t, vm_size_t, vm_size_t));
246 void vm_object_collapse __P((vm_object_t));
247 void vm_object_deallocate __P((vm_object_t));
248 void vm_object_terminate __P((vm_object_t));
249 void vm_object_vndeallocate __P((vm_object_t));
250 void vm_object_init __P((void));
251 void vm_object_page_clean __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
252 void vm_object_page_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
253 void vm_object_pmap_copy __P((vm_object_t, vm_pindex_t, vm_pindex_t));
254 void vm_object_pmap_copy_1 __P((vm_object_t, vm_pindex_t, vm_pindex_t));
255 void vm_object_pmap_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t));
256 void vm_object_reference __P((vm_object_t));
257 void vm_object_shadow __P((vm_object_t *, vm_ooffset_t *, vm_size_t));
258 void vm_object_madvise __P((vm_object_t, vm_pindex_t, int, int));
259 void vm_object_init2 __P((void));
260 #endif				/* KERNEL */
261 
262 #endif				/* _VM_OBJECT_ */
263