1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1999-2001 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <sys/debug.h>
31 #include <sys/cmn_err.h>
32 #include <sys/kmem.h>
33 #include <sys/sysmacros.h>
34 #include <sys/buf.h>
35 #include <sys/user.h>
36 #include <sys/proc.h>
37 #include <sys/systm.h>
38 #include <sys/vmsystm.h>
39 #include <sys/mman.h>
40 #include <sys/vm.h>
41 #include <sys/ddi.h>
42
43 #include <vm/as.h>
44 #include <vm/page.h>
45
46 /*
47 * Prepare for raw I/O request - derived from default_physio()
48 * This is the 'setup' portion of physio, limited to dealing
49 * with unstructured access to a single range of user space addresses.
50 *
51 * This is quite limited in functionality compared to physio().
52 *
53 * 1. allocate and return buf header
54 * 2. lock down user pages and verify access protections
55 *
56 * Use B_READ (S_WRITE) for unstructured access. (We don't know the
57 * direction of the transfer, so use the safest.)
58 */
59
60 int
fc_physio_setup(struct buf ** bpp,void * io_base,size_t io_len)61 fc_physio_setup(struct buf **bpp, void *io_base, size_t io_len)
62 {
63 struct proc *procp;
64 struct as *asp;
65 int error = 0;
66 page_t **pplist;
67 struct buf *bp = *bpp;
68
69 bp = getrbuf(KM_SLEEP);
70 bp->b_iodone = NULL;
71 bp->b_resid = 0;
72 *bpp = bp;
73
74 /* segflg *is always* UIO_USERSPACE for us */
75 procp = ttoproc(curthread);
76 asp = procp->p_as;
77
78 ASSERT(SEMA_HELD(&bp->b_sem));
79
80 bp->b_error = 0;
81 bp->b_proc = procp;
82
83 bp->b_flags = B_BUSY | B_PHYS | B_READ;
84 bp->b_edev = 0;
85 bp->b_lblkno = 0;
86
87 /*
88 * Don't count on b_addr remaining untouched by the
89 * code below (it may be reset because someone does
90 * a bp_mapin on the buffer).
91 */
92 bp->b_un.b_addr = io_base;
93 bp->b_bcount = io_len;
94
95 error = as_pagelock(asp, &pplist, io_base, io_len, S_WRITE);
96
97 if (error != 0) {
98 bp->b_flags |= B_ERROR;
99 bp->b_error = error;
100 bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS);
101 freerbuf(bp);
102 *bpp = NULL;
103 return (error);
104 }
105
106 bp->b_shadow = pplist;
107 if (pplist != NULL) {
108 bp->b_flags |= B_SHADOW;
109 }
110 return (0);
111 }
112
113 /*
114 * unlock the pages and free the buf header, if we allocated it.
115 */
116 void
fc_physio_free(struct buf ** bpp,void * io_base,size_t io_len)117 fc_physio_free(struct buf **bpp, void *io_base, size_t io_len)
118 {
119 struct buf *bp = *bpp;
120 page_t **pplist = NULL;
121
122 /*
123 * unlock the pages
124 */
125
126 if (bp->b_flags & B_SHADOW)
127 pplist = bp->b_shadow;
128
129 as_pageunlock(bp->b_proc->p_as, pplist, io_base, io_len, S_WRITE);
130
131 bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS|B_SHADOW);
132
133 freerbuf(bp);
134 *bpp = NULL;
135 }
136