xref: /dragonfly/sys/vm/vm_object.h (revision 1847e88f)
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 1.7 2005/07/07 16:54:02 hmp 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 {
82 	OBJT_DEFAULT,
83 	OBJT_SWAP,   	/* object backed by swap blocks */
84 	OBJT_VNODE, 	/* object backed by file pages (vnode) */
85 	OBJT_DEVICE, 	/* object backed by device pages */
86 	OBJT_PHYS,  	/* object backed by physical pages */
87 	OBJT_DEAD   	/* dead object */
88 };
89 typedef u_char objtype_t;
90 
91 /*
92  * vm_object_lock	A lock covering byte ranges within a VM object
93  *
94  */
95 struct vm_object_lock {
96 	struct vm_object_lock *next;
97 	int	type;			/* type of lock */
98 	int	waiting;		/* someone is waiting on the lock */
99 	off_t	base;			/* byte offset into object */
100 	off_t	bytes;			/* extent in bytes */
101 };
102 
103 #define VMOBJ_LOCK_SHARED	1
104 #define VMOBJ_LOCK_EXCL		2
105 
106 /*
107  * vm_object		A VM object which represents an arbitrarily sized
108  *			data store.
109  */
110 struct vm_object {
111 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
112 	LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
113 	LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
114 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
115 	int generation;			/* generation ID */
116 	vm_size_t size;			/* Object size */
117 	int ref_count;			/* How many refs?? */
118 	int shadow_count;		/* how many objects that this is a shadow for */
119 	int hash_rand;			/* vm hash table randomizer	*/
120 	objtype_t type;			/* type of pager */
121 	u_short flags;			/* see below */
122 	u_short pg_color;		/* color of first page in obj */
123 	u_short paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
124 	int resident_page_count;	/* number of resident pages */
125 	struct vm_object *backing_object; /* object that I'm a shadow of */
126 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
127 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
128 	void *handle;
129 	vm_object_lock_t range_locks;
130 	union {
131 		/*
132 		 * VNode pager
133 		 *
134 		 *	vnp_size - current size of file
135 		 */
136 		struct {
137 			off_t vnp_size;
138 		} vnp;
139 
140 		/*
141 		 * Device pager
142 		 *
143 		 *	devp_pglist - list of allocated pages
144 		 */
145 		struct {
146 			TAILQ_HEAD(, vm_page) devp_pglist;
147 		} devp;
148 
149 		/*
150 		 * Swap pager
151 		 *
152 		 *	swp_bcount - number of swap 'swblock' metablocks, each
153 		 *		     contains up to 16 swapblk assignments.
154 		 *		     see vm/swap_pager.h
155 		 */
156 		struct {
157 			int swp_bcount;
158 		} swp;
159 	} un_pager;
160 };
161 
162 /*
163  * Flags
164  */
165 #define OBJ_ACTIVE	0x0004		/* active objects */
166 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
167 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
168 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
169 #define	OBJ_WRITEABLE	0x0080		/* object has been made writable */
170 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty */
171 #define OBJ_CLEANING	0x0200
172 #define OBJ_OPT		0x1000		/* I/O optimization */
173 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
174 
175 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
176 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
177 
178 #ifdef	_KERNEL
179 
180 #define OBJPC_SYNC	0x1			/* sync I/O */
181 #define OBJPC_INVAL	0x2			/* invalidate */
182 #define OBJPC_NOSYNC	0x4			/* skip if PG_NOSYNC */
183 
184 TAILQ_HEAD(object_q, vm_object);
185 
186 extern struct object_q vm_object_list;	/* list of allocated objects */
187 
188  /* lock for object list and count */
189 
190 extern vm_object_t kernel_object;	/* the single kernel object */
191 extern vm_object_t kmem_object;
192 
193 #endif				/* _KERNEL */
194 
195 #ifdef _KERNEL
196 
197 static __inline void
198 vm_object_set_flag(vm_object_t object, u_int bits)
199 {
200 	atomic_set_short(&object->flags, bits);
201 }
202 
203 static __inline void
204 vm_object_clear_flag(vm_object_t object, u_int bits)
205 {
206 	atomic_clear_short(&object->flags, bits);
207 }
208 
209 static __inline void
210 vm_object_pip_add(vm_object_t object, int i)
211 {
212 	atomic_add_short(&object->paging_in_progress, i);
213 }
214 
215 static __inline void
216 vm_object_pip_subtract(vm_object_t object, int i)
217 {
218 	atomic_subtract_short(&object->paging_in_progress, i);
219 }
220 
221 static __inline void
222 vm_object_pip_wakeup(vm_object_t object)
223 {
224 	atomic_subtract_short(&object->paging_in_progress, 1);
225 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
226 		vm_object_clear_flag(object, OBJ_PIPWNT);
227 		wakeup(object);
228 	}
229 }
230 
231 static __inline void
232 vm_object_pip_wakeupn(vm_object_t object, int i)
233 {
234 	if (i)
235 		atomic_subtract_short(&object->paging_in_progress, i);
236 	if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
237 		vm_object_clear_flag(object, OBJ_PIPWNT);
238 		wakeup(object);
239 	}
240 }
241 
242 static __inline void
243 vm_object_pip_sleep(vm_object_t object, char *waitid)
244 {
245 	if (object->paging_in_progress) {
246 		crit_enter();
247 		if (object->paging_in_progress) {
248 			vm_object_set_flag(object, OBJ_PIPWNT);
249 			tsleep(object, 0, waitid, 0);
250 		}
251 		crit_exit();
252 	}
253 }
254 
255 static __inline void
256 vm_object_pip_wait(vm_object_t object, char *waitid)
257 {
258 	while (object->paging_in_progress)
259 		vm_object_pip_sleep(object, waitid);
260 }
261 
262 vm_object_t vm_object_allocate (objtype_t, vm_size_t);
263 void _vm_object_allocate (objtype_t, vm_size_t, vm_object_t);
264 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
265 void vm_object_collapse (vm_object_t);
266 void vm_object_deallocate (vm_object_t);
267 void vm_object_terminate (vm_object_t);
268 void vm_object_vndeallocate (vm_object_t);
269 void vm_object_set_writeable_dirty (vm_object_t);
270 void vm_object_init (void);
271 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
272 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
273 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
274 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
275 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
276 void vm_object_reference (vm_object_t);
277 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
278 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
279 void vm_object_init2 (void);
280 #endif				/* _KERNEL */
281 
282 #endif				/* _VM_OBJECT_ */
283