xref: /freebsd/sys/vm/vm_pager.h (revision 8f87df16d414c7b09739ba95030e1e5650207b73)
1 /*-
2  * Copyright (c) 1990 University of Utah.
3  * Copyright (c) 1991, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * the Systems Programming Group of the University of Utah Computer
8  * Science Department.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)vm_pager.h	8.4 (Berkeley) 1/12/94
35  * $FreeBSD$
36  */
37 
38 /*
39  * Pager routine interface definition.
40  */
41 
42 #ifndef	_VM_PAGER_
43 #define	_VM_PAGER_
44 
45 #include <sys/queue.h>
46 
47 TAILQ_HEAD(pagerlst, vm_object);
48 
49 typedef void pgo_init_t(void);
50 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
51     struct ucred *);
52 typedef void pgo_dealloc_t(vm_object_t);
53 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
54 typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
55 typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
56     pgo_getpages_iodone_t, void *);
57 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
58 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
59 typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t,
60     vm_pindex_t *, vm_pindex_t *);
61 typedef void pgo_pageunswapped_t(vm_page_t);
62 
63 struct pagerops {
64 	pgo_init_t		*pgo_init;		/* Initialize pager. */
65 	pgo_alloc_t		*pgo_alloc;		/* Allocate pager. */
66 	pgo_dealloc_t		*pgo_dealloc;		/* Disassociate. */
67 	pgo_getpages_t		*pgo_getpages;		/* Get (read) page. */
68 	pgo_getpages_async_t	*pgo_getpages_async;	/* Get page asyncly. */
69 	pgo_putpages_t		*pgo_putpages;		/* Put (write) page. */
70 	pgo_haspage_t		*pgo_haspage;		/* Query page. */
71 	pgo_populate_t		*pgo_populate;		/* Bulk spec pagein. */
72 	pgo_pageunswapped_t	*pgo_pageunswapped;
73 };
74 
75 extern struct pagerops defaultpagerops;
76 extern struct pagerops swappagerops;
77 extern struct pagerops vnodepagerops;
78 extern struct pagerops devicepagerops;
79 extern struct pagerops physpagerops;
80 extern struct pagerops sgpagerops;
81 extern struct pagerops mgtdevicepagerops;
82 
83 /*
84  * get/put return values
85  * OK	 operation was successful
86  * BAD	 specified data was out of the accepted range
87  * FAIL	 specified data was in range, but doesn't exist
88  * PEND	 operations was initiated but not completed
89  * ERROR error while accessing data that is in range and exists
90  * AGAIN temporary resource shortage prevented operation from happening
91  */
92 #define	VM_PAGER_OK	0
93 #define	VM_PAGER_BAD	1
94 #define	VM_PAGER_FAIL	2
95 #define	VM_PAGER_PEND	3
96 #define	VM_PAGER_ERROR	4
97 #define VM_PAGER_AGAIN	5
98 
99 #define	VM_PAGER_PUT_SYNC		0x0001
100 #define	VM_PAGER_PUT_INVAL		0x0002
101 #define	VM_PAGER_PUT_NOREUSE		0x0004
102 #define VM_PAGER_CLUSTER_OK		0x0008
103 
104 #ifdef _KERNEL
105 
106 extern struct pagerops *pagertab[];
107 extern struct mtx_padalign pbuf_mtx;
108 
109 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
110     vm_ooffset_t, struct ucred *);
111 void vm_pager_bufferinit(void);
112 void vm_pager_deallocate(vm_object_t);
113 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
114 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
115     pgo_getpages_iodone_t, void *);
116 void vm_pager_init(void);
117 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
118 
119 static __inline void
120 vm_pager_put_pages(
121 	vm_object_t object,
122 	vm_page_t *m,
123 	int count,
124 	int flags,
125 	int *rtvals
126 ) {
127 
128 	VM_OBJECT_ASSERT_WLOCKED(object);
129 	(*pagertab[object->type]->pgo_putpages)
130 	    (object, m, count, flags, rtvals);
131 }
132 
133 /*
134  *	vm_pager_haspage
135  *
136  *	Check to see if an object's pager has the requested page.  The
137  *	object's pager will also set before and after to give the caller
138  *	some idea of the number of pages before and after the requested
139  *	page can be I/O'd efficiently.
140  *
141  *	The object must be locked.
142  */
143 static __inline boolean_t
144 vm_pager_has_page(
145 	vm_object_t object,
146 	vm_pindex_t offset,
147 	int *before,
148 	int *after
149 ) {
150 	boolean_t ret;
151 
152 	VM_OBJECT_ASSERT_WLOCKED(object);
153 	ret = (*pagertab[object->type]->pgo_haspage)
154 	    (object, offset, before, after);
155 	return (ret);
156 }
157 
158 static __inline int
159 vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
160     vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
161 {
162 
163 	MPASS((object->flags & OBJ_POPULATE) != 0);
164 	MPASS(pidx < object->size);
165 	MPASS(object->paging_in_progress > 0);
166 	return ((*pagertab[object->type]->pgo_populate)(object, pidx,
167 	    fault_type, max_prot, first, last));
168 }
169 
170 
171 /*
172  *      vm_pager_page_unswapped
173  *
174  *	Destroy swap associated with the page.
175  *
176  *	The object containing the page must be locked.
177  *      This function may not block.
178  *
179  *	XXX: A much better name would be "vm_pager_page_dirtied()"
180  *	XXX: It is not obvious if this could be profitably used by any
181  *	XXX: pagers besides the swap_pager or if it should even be a
182  *	XXX: generic pager_op in the first place.
183  */
184 static __inline void
185 vm_pager_page_unswapped(vm_page_t m)
186 {
187 
188 	VM_OBJECT_ASSERT_LOCKED(m->object);
189 	if (pagertab[m->object->type]->pgo_pageunswapped)
190 		(*pagertab[m->object->type]->pgo_pageunswapped)(m);
191 }
192 
193 struct cdev_pager_ops {
194 	int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
195 	    int prot, vm_page_t *mres);
196 	int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
197 	    int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
198 	    vm_pindex_t *last);
199 	int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
200 	    vm_ooffset_t foff, struct ucred *cred, u_short *color);
201 	void (*cdev_pg_dtor)(void *handle);
202 };
203 
204 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
205     struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
206     vm_ooffset_t foff, struct ucred *cred);
207 vm_object_t cdev_pager_lookup(void *handle);
208 void cdev_pager_free_page(vm_object_t object, vm_page_t m);
209 
210 #endif				/* _KERNEL */
211 #endif				/* _VM_PAGER_ */
212