1 /* $OpenBSD: subr_xxx.c,v 1.15 2015/12/05 10:11:53 tedu 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/conf.h> 42 43 44 /* 45 * Unsupported device function (e.g. writing to read-only device). 46 */ 47 int 48 enodev(void) 49 { 50 51 return (ENODEV); 52 } 53 54 /* 55 * Unconfigured device function; driver not configured. 56 */ 57 int 58 enxio(void) 59 { 60 61 return (ENXIO); 62 } 63 64 /* 65 * Unsupported ioctl function. 66 */ 67 int 68 enoioctl(void) 69 { 70 71 return (ENOTTY); 72 } 73 74 /* 75 * Unsupported system function. 76 * This is used for an otherwise-reasonable operation 77 * that is not supported by the current system binary. 78 */ 79 int 80 enosys(void) 81 { 82 83 return (ENOSYS); 84 } 85 86 /* 87 * Return error for operation not supported 88 * on a specific object or file type. 89 */ 90 int 91 eopnotsupp(void *v) 92 { 93 94 return (EOPNOTSUPP); 95 } 96 97 /* 98 * Generic null operation, always returns success. 99 */ 100 int 101 nullop(void *v) 102 { 103 104 return (0); 105 } 106 107 struct bdevsw * 108 bdevsw_lookup(dev_t dev) 109 { 110 return (&bdevsw[major(dev)]); 111 } 112 113 struct cdevsw * 114 cdevsw_lookup(dev_t dev) 115 { 116 return (&cdevsw[major(dev)]); 117 } 118 119 /* 120 * Convert a character device number to a block device number. 121 */ 122 dev_t 123 chrtoblk(dev_t dev) 124 { 125 int blkmaj; 126 127 if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl) 128 return (NODEV); 129 blkmaj = chrtoblktbl[major(dev)]; 130 if (blkmaj == NODEV) 131 return (NODEV); 132 return (makedev(blkmaj, minor(dev))); 133 } 134 135 /* 136 * Convert a block device number to a character device number. 137 */ 138 dev_t 139 blktochr(dev_t dev) 140 { 141 int blkmaj = major(dev); 142 int i; 143 144 if (blkmaj >= nblkdev) 145 return (NODEV); 146 for (i = 0; i < nchrtoblktbl; i++) 147 if (blkmaj == chrtoblktbl[i]) 148 return (makedev(i, minor(dev))); 149 return (NODEV); 150 } 151 152 /* 153 * Check that we're in a context where it's okay to sleep. 154 */ 155 void 156 assertwaitok(void) 157 { 158 splassert(IPL_NONE); 159 #ifdef DIAGNOSTIC 160 if (curcpu()->ci_mutex_level != 0) 161 panic("assertwaitok: non-zero mutex count: %d", 162 curcpu()->ci_mutex_level); 163 #endif 164 } 165