xref: /dflybsd-src/sys/vm/vm_object.h (revision b5b0912b1891e95ccc48cad83f09239ccb7ffc16)
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: src/sys/vm/vm_object.h,v 1.63.2.3 2003/05/26 19:17:56 alc Exp $
65  * $DragonFly: src/sys/vm/vm_object.h,v 1.6 2005/06/02 21:51:00 dillon Exp $
66  */
67 
68 /*
69  *	Virtual memory object module definitions.
70  */
71 
72 #ifndef	_VM_OBJECT_
73 #define	_VM_OBJECT_
74 
75 #include <sys/queue.h>
76 #include <machine/atomic.h>
77 #ifdef _KERNEL
78 #include <sys/thread2.h>
79 #endif
80 
81 enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_PHYS,
82 		OBJT_DEAD };
83 typedef u_char objtype_t;
84 
85 /*
86  * vm_object_lock	A lock covering byte ranges within a VM object
87  *
88  */
89 struct vm_object_lock {
90 	struct vm_object_lock *next;
91 	int	type;			/* type of lock */
92 	int	waiting;		/* someone is waiting on the lock */
93 	off_t	base;			/* byte offset into object */
94 	off_t	bytes;			/* extent in bytes */
95 };
96 
97 #define VMOBJ_LOCK_SHARED	1
98 #define VMOBJ_LOCK_EXCL		2
99 
100 /*
101  * vm_object		A VM object which represents an arbitrarily sized
102  *			data store.
103  */
104 struct vm_object {
105 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
106 	LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
107 	LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
108 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
109 	int generation;			/* generation ID */
110 	vm_size_t size;			/* Object size */
111 	int ref_count;			/* How many refs?? */
112 	int shadow_count;		/* how many objects that this is a shadow for */
113 	int hash_rand;			/* vm hash table randomizer	*/
114 	objtype_t type;			/* type of pager */
115 	u_short flags;			/* see below */
116 	u_short pg_color;		/* color of first page in obj */
117 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
118 	int resident_page_count;	/* number of resident pages */
119 	struct vm_object *backing_object; /* object that I'm a shadow of */
120 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
121 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
122 	void *handle;
123 	vm_object_lock_t range_locks;
124 	union {
125 		/*
126 		 * VNode pager
127 		 *
128 		 *	vnp_size - current size of file
129 		 */
130 		struct {
131 			off_t vnp_size;
132 		} vnp;
133 
134 		/*
135 		 * Device pager
136 		 *
137 		 *	devp_pglist - list of allocated pages
138 		 */
139 		struct {
140 			TAILQ_HEAD(, vm_page) devp_pglist;
141 		} devp;
142 
143 		/*
144 		 * Swap pager
145 		 *
146 		 *	swp_bcount - number of swap 'swblock' metablocks, each
147 		 *		     contains up to 16 swapblk assignments.
148 		 *		     see vm/swap_pager.h
149 		 */
150 		struct {
151 			int swp_bcount;
152 		} swp;
153 	} un_pager;
154 };
155 
156 /*
157  * Flags
158  */
159 #define OBJ_ACTIVE	0x0004		/* active objects */
160 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
161 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
162 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
163 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
164 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty */
165 #define OBJ_CLEANING	0x0200
166 #define OBJ_OPT		0x1000		/* I/O optimization */
167 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
168 
169 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
170 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
171 
172 #ifdef	_KERNEL
173 
174 #define OBJPC_SYNC	0x1			/* sync I/O */
175 #define OBJPC_INVAL	0x2			/* invalidate */
176 #define OBJPC_NOSYNC	0x4			/* skip if PG_NOSYNC */
177 
178 TAILQ_HEAD(object_q, vm_object);
179 
180 extern struct object_q vm_object_list;	/* list of allocated objects */
181 
182  /* lock for object list and count */
183 
184 extern vm_object_t kernel_object;	/* the single kernel object */
185 extern vm_object_t kmem_object;
186 
187 #endif				/* _KERNEL */
188 
189 #ifdef _KERNEL
190 
191 static __inline void
192 vm_object_set_flag(vm_object_t object, u_int bits)
193 {
194 	atomic_set_short(&object->flags, bits);
195 }
196 
197 static __inline void
198 vm_object_clear_flag(vm_object_t object, u_int bits)
199 {
200 	atomic_clear_short(&object->flags, bits);
201 }
202 
203 static __inline void
204 vm_object_pip_add(vm_object_t object, int i)
205 {
206 	atomic_add_short(&object->paging_in_progress, i);
207 }
208 
209 static __inline void
210 vm_object_pip_subtract(vm_object_t object, int i)
211 {
212 	atomic_subtract_short(&object->paging_in_progress, i);
213 }
214 
215 static __inline void
216 vm_object_pip_wakeup(vm_object_t object)
217 {
218 	atomic_subtract_short(&object->paging_in_progress, 1);
219 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
220 		vm_object_clear_flag(object, OBJ_PIPWNT);
221 		wakeup(object);
222 	}
223 }
224 
225 static __inline void
226 vm_object_pip_wakeupn(vm_object_t object, int i)
227 {
228 	if (i)
229 		atomic_subtract_short(&object->paging_in_progress, i);
230 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
231 		vm_object_clear_flag(object, OBJ_PIPWNT);
232 		wakeup(object);
233 	}
234 }
235 
236 static __inline void
237 vm_object_pip_sleep(vm_object_t object, char *waitid)
238 {
239 	if (object->paging_in_progress) {
240 		crit_enter();
241 		if (object->paging_in_progress) {
242 			vm_object_set_flag(object, OBJ_PIPWNT);
243 			tsleep(object, 0, waitid, 0);
244 		}
245 		crit_exit();
246 	}
247 }
248 
249 static __inline void
250 vm_object_pip_wait(vm_object_t object, char *waitid)
251 {
252 	while (object->paging_in_progress)
253 		vm_object_pip_sleep(object, waitid);
254 }
255 
256 vm_object_t vm_object_allocate (objtype_t, vm_size_t);
257 void _vm_object_allocate (objtype_t, vm_size_t, vm_object_t);
258 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
259 void vm_object_collapse (vm_object_t);
260 void vm_object_deallocate (vm_object_t);
261 void vm_object_terminate (vm_object_t);
262 void vm_object_vndeallocate (vm_object_t);
263 void vm_object_set_writeable_dirty (vm_object_t);
264 void vm_object_init (void);
265 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
266 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
267 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
268 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
269 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
270 void vm_object_reference (vm_object_t);
271 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
272 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
273 void vm_object_init2 (void);
274 #endif				/* _KERNEL */
275 
276 #endif				/* _VM_OBJECT_ */
277