xref: /dragonfly/sys/vm/vm_object.h (revision 9dbf638f)
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 1.4 2003/08/20 08:03:01 rob 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 
78 enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_PHYS,
79 		OBJT_DEAD };
80 typedef u_char objtype_t;
81 
82 /*
83  * vm_object_lock	A lock covering byte ranges within a VM object
84  *
85  */
86 struct vm_object_lock {
87 	struct vm_object_lock *next;
88 	int	type;			/* type of lock */
89 	int	waiting;		/* someone is waiting on the lock */
90 	off_t	base;			/* byte offset into object */
91 	off_t	bytes;			/* extent in bytes */
92 };
93 
94 #define VMOBJ_LOCK_SHARED	1
95 #define VMOBJ_LOCK_EXCL		2
96 
97 /*
98  * vm_object		A VM object which represents an arbitrarily sized
99  *			data store.
100  */
101 struct vm_object {
102 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
103 	LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
104 	LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
105 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
106 	int generation;			/* generation ID */
107 	vm_size_t size;			/* Object size */
108 	int ref_count;			/* How many refs?? */
109 	int shadow_count;		/* how many objects that this is a shadow for */
110 	int hash_rand;			/* vm hash table randomizer	*/
111 	objtype_t type;			/* type of pager */
112 	u_short flags;			/* see below */
113 	u_short pg_color;		/* color of first page in obj */
114 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
115 	int resident_page_count;	/* number of resident pages */
116 	struct vm_object *backing_object; /* object that I'm a shadow of */
117 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
118 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
119 	void *handle;
120 	vm_object_lock_t range_locks;
121 	union {
122 		/*
123 		 * VNode pager
124 		 *
125 		 *	vnp_size - current size of file
126 		 */
127 		struct {
128 			off_t vnp_size;
129 		} vnp;
130 
131 		/*
132 		 * Device pager
133 		 *
134 		 *	devp_pglist - list of allocated pages
135 		 */
136 		struct {
137 			TAILQ_HEAD(, vm_page) devp_pglist;
138 		} devp;
139 
140 		/*
141 		 * Swap pager
142 		 *
143 		 *	swp_bcount - number of swap 'swblock' metablocks, each
144 		 *		     contains up to 16 swapblk assignments.
145 		 *		     see vm/swap_pager.h
146 		 */
147 		struct {
148 			int swp_bcount;
149 		} swp;
150 	} un_pager;
151 };
152 
153 /*
154  * Flags
155  */
156 #define OBJ_ACTIVE	0x0004		/* active objects */
157 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
158 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
159 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
160 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
161 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty */
162 #define OBJ_CLEANING	0x0200
163 #define OBJ_OPT		0x1000		/* I/O optimization */
164 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
165 
166 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
167 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
168 
169 #ifdef	_KERNEL
170 
171 #define OBJPC_SYNC	0x1			/* sync I/O */
172 #define OBJPC_INVAL	0x2			/* invalidate */
173 #define OBJPC_NOSYNC	0x4			/* skip if PG_NOSYNC */
174 
175 TAILQ_HEAD(object_q, vm_object);
176 
177 extern struct object_q vm_object_list;	/* list of allocated objects */
178 
179  /* lock for object list and count */
180 
181 extern vm_object_t kernel_object;	/* the single kernel object */
182 extern vm_object_t kmem_object;
183 
184 #endif				/* _KERNEL */
185 
186 #ifdef _KERNEL
187 
188 static __inline void
189 vm_object_set_flag(vm_object_t object, u_int bits)
190 {
191 	atomic_set_short(&object->flags, bits);
192 }
193 
194 static __inline void
195 vm_object_clear_flag(vm_object_t object, u_int bits)
196 {
197 	atomic_clear_short(&object->flags, bits);
198 }
199 
200 static __inline void
201 vm_object_pip_add(vm_object_t object, int i)
202 {
203 	atomic_add_short(&object->paging_in_progress, i);
204 }
205 
206 static __inline void
207 vm_object_pip_subtract(vm_object_t object, int i)
208 {
209 	atomic_subtract_short(&object->paging_in_progress, i);
210 }
211 
212 static __inline void
213 vm_object_pip_wakeup(vm_object_t object)
214 {
215 	atomic_subtract_short(&object->paging_in_progress, 1);
216 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
217 		vm_object_clear_flag(object, OBJ_PIPWNT);
218 		wakeup(object);
219 	}
220 }
221 
222 static __inline void
223 vm_object_pip_wakeupn(vm_object_t object, int i)
224 {
225 	if (i)
226 		atomic_subtract_short(&object->paging_in_progress, i);
227 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
228 		vm_object_clear_flag(object, OBJ_PIPWNT);
229 		wakeup(object);
230 	}
231 }
232 
233 static __inline void
234 vm_object_pip_sleep(vm_object_t object, char *waitid)
235 {
236 	if (object->paging_in_progress) {
237 		int s = splvm();
238 		if (object->paging_in_progress) {
239 			vm_object_set_flag(object, OBJ_PIPWNT);
240 			tsleep(object, 0, waitid, 0);
241 		}
242 		splx(s);
243 	}
244 }
245 
246 static __inline void
247 vm_object_pip_wait(vm_object_t object, char *waitid)
248 {
249 	while (object->paging_in_progress)
250 		vm_object_pip_sleep(object, waitid);
251 }
252 
253 vm_object_t vm_object_allocate (objtype_t, vm_size_t);
254 void _vm_object_allocate (objtype_t, vm_size_t, vm_object_t);
255 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
256 void vm_object_collapse (vm_object_t);
257 void vm_object_deallocate (vm_object_t);
258 void vm_object_terminate (vm_object_t);
259 void vm_object_vndeallocate (vm_object_t);
260 void vm_object_set_writeable_dirty (vm_object_t);
261 void vm_object_init (void);
262 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
263 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
264 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
265 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
266 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
267 void vm_object_reference (vm_object_t);
268 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
269 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
270 void vm_object_init2 (void);
271 #endif				/* _KERNEL */
272 
273 #endif				/* _VM_OBJECT_ */
274