xref: /freebsd/sys/vm/vm_object.h (revision c243e4902be8df1e643c76b5f18b68bb77cc5268)
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  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	from: @(#)vm_object.h	8.3 (Berkeley) 1/12/94
33  *
34  *
35  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36  * All rights reserved.
37  *
38  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39  *
40  * Permission to use, copy, modify and distribute this software and
41  * its documentation is hereby granted, provided that both the copyright
42  * notice and this permission notice appear in all copies of the
43  * software, derivative works or modified versions, and any portions
44  * thereof, and that both notices appear in supporting documentation.
45  *
46  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49  *
50  * Carnegie Mellon requests users of this software to return to
51  *
52  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
53  *  School of Computer Science
54  *  Carnegie Mellon University
55  *  Pittsburgh PA 15213-3890
56  *
57  * any improvements or extensions that they make and grant Carnegie the
58  * rights to redistribute these changes.
59  *
60  * $FreeBSD$
61  */
62 
63 /*
64  *	Virtual memory object module definitions.
65  */
66 
67 #ifndef	_VM_OBJECT_
68 #define	_VM_OBJECT_
69 
70 #include <sys/queue.h>
71 #include <sys/_lock.h>
72 #include <sys/_mutex.h>
73 
74 /*
75  *	Types defined:
76  *
77  *	vm_object_t		Virtual memory object.
78  *
79  *	The root of cached pages pool is protected by both the per-object mutex
80  *	and the free pages queue mutex.
81  *	On insert in the cache splay tree, the per-object mutex is expected
82  *	to be already held and the free pages queue mutex will be
83  *	acquired during the operation too.
84  *	On remove and lookup from the cache splay tree, only the free
85  *	pages queue mutex is expected to be locked.
86  *	These rules allow for reliably checking for the presence of cached
87  *	pages with only the per-object lock held, thereby reducing contention
88  *	for the free pages queue mutex.
89  *
90  * List of locks
91  *	(c)	const until freed
92  *	(o)	per-object mutex
93  *	(f)	free pages queue mutex
94  *
95  */
96 
97 struct vm_object {
98 	struct mtx mtx;
99 	TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
100 	LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
101 	LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
102 	TAILQ_HEAD(, vm_page) memq;	/* list of resident pages */
103 	vm_page_t root;			/* root of the resident page splay tree */
104 	vm_pindex_t size;		/* Object size */
105 	int generation;			/* generation ID */
106 	int ref_count;			/* How many refs?? */
107 	int shadow_count;		/* how many objects that this is a shadow for */
108 	vm_memattr_t memattr;		/* default memory attribute for pages */
109 	objtype_t type;			/* type of pager */
110 	u_short flags;			/* see below */
111 	u_short pg_color;		/* (c) color of first page in obj */
112 	u_int paging_in_progress;	/* Paging (in or out) so don't collapse or destroy */
113 	int resident_page_count;	/* number of resident pages */
114 	struct vm_object *backing_object; /* object that I'm a shadow of */
115 	vm_ooffset_t backing_object_offset;/* Offset in backing object */
116 	TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
117 	LIST_HEAD(, vm_reserv) rvq;	/* list of reservations */
118 	vm_page_t cache;		/* (o + f) root of the cache page splay tree */
119 	void *handle;
120 	union {
121 		/*
122 		 * VNode pager
123 		 *
124 		 *	vnp_size - current size of file
125 		 */
126 		struct {
127 			off_t vnp_size;
128 			vm_ooffset_t writemappings;
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 			struct cdev_pager_ops *ops;
139 		} devp;
140 
141 		/*
142 		 * SG pager
143 		 *
144 		 *	sgp_pglist - list of allocated pages
145 		 */
146 		struct {
147 			TAILQ_HEAD(, vm_page) sgp_pglist;
148 		} sgp;
149 
150 		/*
151 		 * Swap pager
152 		 *
153 		 *	swp_bcount - number of swap 'swblock' metablocks, each
154 		 *		     contains up to 16 swapblk assignments.
155 		 *		     see vm/swap_pager.h
156 		 */
157 		struct {
158 			int swp_bcount;
159 		} swp;
160 	} un_pager;
161 	struct ucred *cred;
162 	vm_ooffset_t charge;
163 };
164 
165 /*
166  * Flags
167  */
168 #define OBJ_ACTIVE	0x0004		/* active objects */
169 #define OBJ_DEAD	0x0008		/* dead objects (during rundown) */
170 #define	OBJ_NOSPLIT	0x0010		/* dont split this object */
171 #define OBJ_PIPWNT	0x0040		/* paging in progress wanted */
172 #define OBJ_MIGHTBEDIRTY 0x0100		/* object might be dirty, only for vnode */
173 #define	OBJ_COLORED	0x1000		/* pg_color is defined */
174 #define	OBJ_ONEMAPPING	0x2000		/* One USE (a single, non-forked) mapping flag */
175 #define	OBJ_DISCONNECTWNT 0x4000	/* disconnect from vnode wanted */
176 
177 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
178 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
179 
180 #ifdef	_KERNEL
181 
182 #define OBJPC_SYNC	0x1			/* sync I/O */
183 #define OBJPC_INVAL	0x2			/* invalidate */
184 #define OBJPC_NOSYNC	0x4			/* skip if PG_NOSYNC */
185 
186 /*
187  * The following options are supported by vm_object_page_remove().
188  */
189 #define	OBJPR_CLEANONLY	0x1		/* Don't remove dirty pages. */
190 #define	OBJPR_NOTMAPPED	0x2		/* Don't unmap pages. */
191 
192 TAILQ_HEAD(object_q, vm_object);
193 
194 extern struct object_q vm_object_list;	/* list of allocated objects */
195 extern struct mtx vm_object_list_mtx;	/* lock for object list and count */
196 
197 extern struct vm_object kernel_object_store;
198 extern struct vm_object kmem_object_store;
199 
200 #define	kernel_object	(&kernel_object_store)
201 #define	kmem_object	(&kmem_object_store)
202 
203 #define	VM_OBJECT_LOCK(object)		mtx_lock(&(object)->mtx)
204 #define	VM_OBJECT_LOCK_ASSERT(object, type) \
205 					mtx_assert(&(object)->mtx, (type))
206 #define	VM_OBJECT_LOCK_INIT(object, type) \
207 					mtx_init(&(object)->mtx, "vm object", \
208 					    (type), MTX_DEF | MTX_DUPOK)
209 #define	VM_OBJECT_LOCKED(object)	mtx_owned(&(object)->mtx)
210 #define	VM_OBJECT_MTX(object)		(&(object)->mtx)
211 #define	VM_OBJECT_TRYLOCK(object)	mtx_trylock(&(object)->mtx)
212 #define	VM_OBJECT_UNLOCK(object)	mtx_unlock(&(object)->mtx)
213 
214 /*
215  *	The object must be locked or thread private.
216  */
217 static __inline void
218 vm_object_set_flag(vm_object_t object, u_short bits)
219 {
220 
221 	object->flags |= bits;
222 }
223 
224 void vm_object_clear_flag(vm_object_t object, u_short bits);
225 void vm_object_pip_add(vm_object_t object, short i);
226 void vm_object_pip_subtract(vm_object_t object, short i);
227 void vm_object_pip_wakeup(vm_object_t object);
228 void vm_object_pip_wakeupn(vm_object_t object, short i);
229 void vm_object_pip_wait(vm_object_t object, char *waitid);
230 
231 vm_object_t vm_object_allocate (objtype_t, vm_pindex_t);
232 void _vm_object_allocate (objtype_t, vm_pindex_t, vm_object_t);
233 boolean_t vm_object_coalesce(vm_object_t, vm_ooffset_t, vm_size_t, vm_size_t,
234    boolean_t);
235 void vm_object_collapse (vm_object_t);
236 void vm_object_deallocate (vm_object_t);
237 void vm_object_destroy (vm_object_t);
238 void vm_object_terminate (vm_object_t);
239 void vm_object_set_writeable_dirty (vm_object_t);
240 void vm_object_init (void);
241 void vm_object_madvise(vm_object_t, vm_pindex_t, vm_pindex_t, int);
242 void vm_object_page_cache(vm_object_t object, vm_pindex_t start,
243     vm_pindex_t end);
244 boolean_t vm_object_page_clean(vm_object_t object, vm_ooffset_t start,
245     vm_ooffset_t end, int flags);
246 void vm_object_page_remove(vm_object_t object, vm_pindex_t start,
247     vm_pindex_t end, int options);
248 boolean_t vm_object_populate(vm_object_t, vm_pindex_t, vm_pindex_t);
249 void vm_object_print(long addr, boolean_t have_addr, long count, char *modif);
250 void vm_object_reference (vm_object_t);
251 void vm_object_reference_locked(vm_object_t);
252 int  vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr);
253 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
254 void vm_object_split(vm_map_entry_t);
255 boolean_t vm_object_sync(vm_object_t, vm_ooffset_t, vm_size_t, boolean_t,
256     boolean_t);
257 #endif				/* _KERNEL */
258 
259 #endif				/* _VM_OBJECT_ */
260