1 /* $OpenBSD: subr_xxx.c,v 1.13 2013/03/28 16:55:25 deraadt Exp $ */ 2 /* $NetBSD: subr_xxx.c,v 1.10 1996/02/04 02:16:51 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 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. 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 * @(#)subr_xxx.c 8.1 (Berkeley) 6/10/93 33 */ 34 35 /* 36 * Miscellaneous trivial functions, including many 37 * that are often inline-expanded or done in assembler. 38 */ 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/device.h> 42 #include <sys/conf.h> 43 44 45 /* 46 * Unsupported device function (e.g. writing to read-only device). 47 */ 48 int 49 enodev(void) 50 { 51 52 return (ENODEV); 53 } 54 55 /* 56 * Unconfigured device function; driver not configured. 57 */ 58 int 59 enxio(void) 60 { 61 62 return (ENXIO); 63 } 64 65 /* 66 * Unsupported ioctl function. 67 */ 68 int 69 enoioctl(void) 70 { 71 72 return (ENOTTY); 73 } 74 75 /* 76 * Unsupported system function. 77 * This is used for an otherwise-reasonable operation 78 * that is not supported by the current system binary. 79 */ 80 int 81 enosys(void) 82 { 83 84 return (ENOSYS); 85 } 86 87 /* 88 * Return error for operation not supported 89 * on a specific object or file type. 90 */ 91 /*ARGSUSED*/ 92 int 93 eopnotsupp(void *v) 94 { 95 96 return (EOPNOTSUPP); 97 } 98 99 /* 100 * Generic null operation, always returns success. 101 */ 102 /*ARGSUSED*/ 103 int 104 nullop(void *v) 105 { 106 107 return (0); 108 } 109 110 struct bdevsw * 111 bdevsw_lookup(dev_t dev) 112 { 113 return (&bdevsw[major(dev)]); 114 } 115 116 struct cdevsw * 117 cdevsw_lookup(dev_t dev) 118 { 119 return (&cdevsw[major(dev)]); 120 } 121 122 /* 123 * Convert a character device number to a block device number. 124 */ 125 dev_t 126 chrtoblk(dev_t dev) 127 { 128 int blkmaj; 129 130 if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl) 131 return (NODEV); 132 blkmaj = chrtoblktbl[major(dev)]; 133 if (blkmaj == NODEV) 134 return (NODEV); 135 return (makedev(blkmaj, minor(dev))); 136 } 137 138 /* 139 * Convert a block device number to a character device number. 140 */ 141 dev_t 142 blktochr(dev_t dev) 143 { 144 int blkmaj = major(dev); 145 int i; 146 147 if (blkmaj >= nblkdev) 148 return (NODEV); 149 for (i = 0; i < nchrtoblktbl; i++) 150 if (blkmaj == chrtoblktbl[i]) 151 return (makedev(i, minor(dev))); 152 return (NODEV); 153 } 154 155 /* 156 * Check that we're in a context where it's okay to sleep. 157 */ 158 void 159 assertwaitok(void) 160 { 161 splassert(IPL_NONE); 162 #ifdef DIAGNOSTIC 163 if (curcpu()->ci_mutex_level != 0) 164 panic("assertwaitok: non-zero mutex count: %d", 165 curcpu()->ci_mutex_level); 166 #endif 167 } 168