xref: /netbsd-src/sys/uvm/uvm_object.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: uvm_object.c,v 1.3 2007/02/17 20:45:36 rmind Exp $	*/
2 
3 /*
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Mindaugas Rasiukevicius.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the NetBSD
21  *      Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * uvm_object.c: operate with memory objects
41  *
42  * TODO:
43  *  1. Support PG_RELEASED-using objects
44  *
45  */
46 
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.3 2007/02/17 20:45:36 rmind Exp $");
49 
50 #include "opt_uvmhist.h"
51 
52 #include <sys/param.h>
53 #include <sys/lock.h>
54 
55 #include <uvm/uvm.h>
56 
57 /* We will fetch this page count per step */
58 #define	FETCH_PAGECOUNT	16
59 
60 /*
61  * uobj_wirepages: wire the pages of entire uobj
62  *
63  * => NOTE: this function should only be used for types of objects
64  *  where PG_RELEASED flag is never set (aobj objects)
65  * => caller must pass page-aligned start and end values
66  */
67 
68 int
69 uobj_wirepages(struct uvm_object *uobj, off_t start, off_t end)
70 {
71 	int i, npages, error;
72 	struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL;
73 	off_t offset = start, left;
74 
75 	left = (end - start) >> PAGE_SHIFT;
76 
77 	simple_lock(&uobj->vmobjlock);
78 	while (left) {
79 
80 		npages = MIN(FETCH_PAGECOUNT, left);
81 
82 		/* Get the pages */
83 		memset(pgs, 0, sizeof(pgs));
84 		error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
85 			VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL,
86 			PGO_ALLPAGES | PGO_SYNCIO);
87 
88 		if (error)
89 			goto error;
90 
91 		simple_lock(&uobj->vmobjlock);
92 		for (i = 0; i < npages; i++) {
93 
94 			KASSERT(pgs[i] != NULL);
95 			KASSERT(!(pgs[i]->flags & PG_RELEASED));
96 
97 			/*
98 			 * Loan break
99 			 */
100 			if (pgs[i]->loan_count) {
101 				while (pgs[i]->loan_count) {
102 					pg = uvm_loanbreak(pgs[i]);
103 					if (!pg) {
104 						simple_unlock(&uobj->vmobjlock);
105 						uvm_wait("uobjwirepg");
106 						simple_lock(&uobj->vmobjlock);
107 						continue;
108 					}
109 				}
110 				pgs[i] = pg;
111 			}
112 
113 			if (pgs[i]->pqflags & PQ_AOBJ) {
114 				pgs[i]->flags &= ~(PG_CLEAN);
115 				uao_dropswap(uobj, i);
116 			}
117 		}
118 
119 		/* Wire the pages */
120 		uvm_lock_pageq();
121 		for (i = 0; i < npages; i++) {
122 			uvm_pagewire(pgs[i]);
123 		}
124 		uvm_unlock_pageq();
125 
126 		/* Unbusy the pages */
127 		uvm_page_unbusy(pgs, npages);
128 
129 		left -= npages;
130 		offset += npages << PAGE_SHIFT;
131 	}
132 	simple_unlock(&uobj->vmobjlock);
133 
134 	return 0;
135 
136 error:
137 	/* Unwire the pages which has been wired */
138 	uobj_unwirepages(uobj, start, offset);
139 
140 	return error;
141 }
142 
143 /*
144  * uobj_unwirepages: unwire the pages of entire uobj
145  *
146  * => NOTE: this function should only be used for types of objects
147  *  where PG_RELEASED flag is never set
148  * => caller must pass page-aligned start and end values
149  */
150 
151 void
152 uobj_unwirepages(struct uvm_object *uobj, off_t start, off_t end)
153 {
154 	struct vm_page *pg;
155 	off_t offset;
156 
157 	simple_lock(&uobj->vmobjlock);
158 	uvm_lock_pageq();
159 	for (offset = start; offset < end; offset += PAGE_SIZE) {
160 		pg = uvm_pagelookup(uobj, offset);
161 
162 		KASSERT(pg != NULL);
163 		KASSERT(!(pg->flags & PG_RELEASED));
164 
165 		uvm_pageunwire(pg);
166 	}
167 	uvm_unlock_pageq();
168 	simple_unlock(&uobj->vmobjlock);
169 }
170