xref: /freebsd/sys/vm/vm_object.h (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
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  * $FreeBSD$
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_PHYS,
78 		OBJT_DEAD };
79 typedef u_char objtype_t;
80 
81 /*
82  *	Types defined:
83  *
84  *	vm_object_t		Virtual memory object.
85  *
86  */
87 
88 struct vm_object {
89 	TAILQ_ENTRY(vm_object) object_list; /* list of all 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 	int generation;			/* generation ID */
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 hash_rand;			/* vm hash table randomizer	*/
98 	objtype_t type;			/* type of pager */
99 	u_short flags;			/* see below */
100 	u_short pg_color;		/* color of first page in obj */
101 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
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 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
106 	void *handle;
107 	union {
108 		/*
109 		 * VNode pager
110 		 *
111 		 *	vnp_size - current size of file
112 		 */
113 		struct {
114 			off_t vnp_size;
115 		} vnp;
116 
117 		/*
118 		 * Device pager
119 		 *
120 		 *	devp_pglist - list of allocated pages
121 		 */
122 		struct {
123 			TAILQ_HEAD(, vm_page) devp_pglist;
124 		} devp;
125 
126 #if 0
127 		/*
128 		 * Physmem pager
129 		 *
130 		 *	physp_pglist - list of allocated pages
131 		 */
132 		struct {
133 			TAILQ_HEAD(, vm_page) physp_pglist;
134 		} physp;
135 #endif
136 
137 		/*
138 		 * Swap pager
139 		 *
140 		 *	swp_bcount - number of swap 'swblock' metablocks, each
141 		 *		     contains up to 16 swapblk assignments.
142 		 *		     see vm/swap_pager.h
143 		 */
144 		struct {
145 			int swp_bcount;
146 		} swp;
147 	} un_pager;
148 };
149 
150 /*
151  * Flags
152  */
153 #define OBJ_ACTIVE	0x0004		/* active objects */
154 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
155 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
156 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
157 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
158 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty */
159 #define OBJ_CLEANING	0x0200
160 #define OBJ_OPT		0x1000		/* I/O optimization */
161 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
162 
163 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
164 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
165 
166 #ifdef	_KERNEL
167 
168 #define OBJPC_SYNC	0x1			/* sync I/O */
169 #define OBJPC_INVAL	0x2			/* invalidate */
170 #define OBJPC_NOSYNC	0x4			/* skip if PG_NOSYNC */
171 
172 TAILQ_HEAD(object_q, vm_object);
173 
174 extern struct object_q vm_object_list;	/* list of allocated objects */
175 
176  /* lock for object list and count */
177 
178 extern vm_object_t kernel_object;	/* the single kernel object */
179 extern vm_object_t kmem_object;
180 
181 #endif				/* _KERNEL */
182 
183 #ifdef _KERNEL
184 
185 static __inline void
186 vm_object_set_flag(vm_object_t object, u_int bits)
187 {
188 	atomic_set_short(&object->flags, bits);
189 }
190 
191 static __inline void
192 vm_object_clear_flag(vm_object_t object, u_int bits)
193 {
194 	atomic_clear_short(&object->flags, bits);
195 }
196 
197 static __inline void
198 vm_object_pip_add(vm_object_t object, int i)
199 {
200 	atomic_add_short(&object->paging_in_progress, i);
201 }
202 
203 static __inline void
204 vm_object_pip_subtract(vm_object_t object, int i)
205 {
206 	atomic_subtract_short(&object->paging_in_progress, i);
207 }
208 
209 static __inline void
210 vm_object_pip_wakeup(vm_object_t object)
211 {
212 	atomic_subtract_short(&object->paging_in_progress, 1);
213 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
214 		vm_object_clear_flag(object, OBJ_PIPWNT);
215 		wakeup(object);
216 	}
217 }
218 
219 static __inline void
220 vm_object_pip_wakeupn(vm_object_t object, int i)
221 {
222 	if (i)
223 		atomic_subtract_short(&object->paging_in_progress, i);
224 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
225 		vm_object_clear_flag(object, OBJ_PIPWNT);
226 		wakeup(object);
227 	}
228 }
229 
230 static __inline void
231 vm_object_pip_sleep(vm_object_t object, char *waitid)
232 {
233 	if (object->paging_in_progress) {
234 		int s = splvm();
235 		if (object->paging_in_progress) {
236 			vm_object_set_flag(object, OBJ_PIPWNT);
237 			tsleep(object, PVM, waitid, 0);
238 		}
239 		splx(s);
240 	}
241 }
242 
243 static __inline void
244 vm_object_pip_wait(vm_object_t object, char *waitid)
245 {
246 	while (object->paging_in_progress)
247 		vm_object_pip_sleep(object, waitid);
248 }
249 
250 vm_object_t vm_object_allocate __P((objtype_t, vm_size_t));
251 void _vm_object_allocate __P((objtype_t, vm_size_t, vm_object_t));
252 boolean_t vm_object_coalesce __P((vm_object_t, vm_pindex_t, vm_size_t, vm_size_t));
253 void vm_object_collapse __P((vm_object_t));
254 void vm_object_deallocate __P((vm_object_t));
255 void vm_object_terminate __P((vm_object_t));
256 void vm_object_vndeallocate __P((vm_object_t));
257 void vm_object_init __P((void));
258 void vm_object_page_clean __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
259 void vm_object_page_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t));
260 void vm_object_pmap_copy __P((vm_object_t, vm_pindex_t, vm_pindex_t));
261 void vm_object_pmap_copy_1 __P((vm_object_t, vm_pindex_t, vm_pindex_t));
262 void vm_object_pmap_remove __P((vm_object_t, vm_pindex_t, vm_pindex_t));
263 void vm_object_reference __P((vm_object_t));
264 void vm_object_shadow __P((vm_object_t *, vm_ooffset_t *, vm_size_t));
265 void vm_object_madvise __P((vm_object_t, vm_pindex_t, int, int));
266 void vm_object_init2 __P((void));
267 #endif				/* _KERNEL */
268 
269 #endif				/* _VM_OBJECT_ */
270