1 /* $OpenBSD: subr_xxx.c,v 1.12 2010/09/28 20:27:56 miod 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 #include <machine/cpu.h> 45 46 /* 47 * Unsupported device function (e.g. writing to read-only device). 48 */ 49 int 50 enodev(void) 51 { 52 53 return (ENODEV); 54 } 55 56 /* 57 * Unconfigured device function; driver not configured. 58 */ 59 int 60 enxio(void) 61 { 62 63 return (ENXIO); 64 } 65 66 /* 67 * Unsupported ioctl function. 68 */ 69 int 70 enoioctl(void) 71 { 72 73 return (ENOTTY); 74 } 75 76 /* 77 * Unsupported system function. 78 * This is used for an otherwise-reasonable operation 79 * that is not supported by the current system binary. 80 */ 81 int 82 enosys(void) 83 { 84 85 return (ENOSYS); 86 } 87 88 /* 89 * Return error for operation not supported 90 * on a specific object or file type. 91 */ 92 /*ARGSUSED*/ 93 int 94 eopnotsupp(void *v) 95 { 96 97 return (EOPNOTSUPP); 98 } 99 100 /* 101 * Generic null operation, always returns success. 102 */ 103 /*ARGSUSED*/ 104 int 105 nullop(void *v) 106 { 107 108 return (0); 109 } 110 111 struct bdevsw * 112 bdevsw_lookup(dev_t dev) 113 { 114 return (&bdevsw[major(dev)]); 115 } 116 117 struct cdevsw * 118 cdevsw_lookup(dev_t dev) 119 { 120 return (&cdevsw[major(dev)]); 121 } 122 123 /* 124 * Convert a character device number to a block device number. 125 */ 126 dev_t 127 chrtoblk(dev_t dev) 128 { 129 int blkmaj; 130 131 if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl) 132 return (NODEV); 133 blkmaj = chrtoblktbl[major(dev)]; 134 if (blkmaj == NODEV) 135 return (NODEV); 136 return (makedev(blkmaj, minor(dev))); 137 } 138 139 /* 140 * Convert a block device number to a character device number. 141 */ 142 dev_t 143 blktochr(dev_t dev) 144 { 145 int blkmaj = major(dev); 146 int i; 147 148 if (blkmaj >= nblkdev) 149 return (NODEV); 150 for (i = 0; i < nchrtoblktbl; i++) 151 if (blkmaj == chrtoblktbl[i]) 152 return (makedev(i, minor(dev))); 153 return (NODEV); 154 } 155 156 /* 157 * Check that we're in a context where it's okay to sleep. 158 */ 159 void 160 assertwaitok(void) 161 { 162 splassert(IPL_NONE); 163 #ifdef DIAGNOSTIC 164 if (curcpu()->ci_mutex_level != 0) 165 panic("assertwaitok: non-zero mutex count: %d", 166 curcpu()->ci_mutex_level); 167 #endif 168 } 169