1/* $OpenBSD: subr_xxx.c,v 1.17 2019/05/17 03:53:08 visa 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#include <sys/smr.h> 43 44 45/* 46 * Unsupported device function (e.g. writing to read-only device). 47 */ 48int 49enodev(void) 50{ 51 52 return (ENODEV); 53} 54 55/* 56 * Unconfigured device function; driver not configured. 57 */ 58int 59enxio(void) 60{ 61 62 return (ENXIO); 63} 64 65/* 66 * Unsupported ioctl function. 67 */ 68int 69enoioctl(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 */ 80int 81enosys(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 */ 91int 92eopnotsupp(void *v) 93{ 94 95 return (EOPNOTSUPP); 96} 97 98/* 99 * Generic null operation, always returns success. 100 */ 101int 102nullop(void *v) 103{ 104 105 return (0); 106} 107 108struct bdevsw * 109bdevsw_lookup(dev_t dev) 110{ 111 return (&bdevsw[major(dev)]); 112} 113 114struct cdevsw * 115cdevsw_lookup(dev_t dev) 116{ 117 return (&cdevsw[major(dev)]); 118} 119 120/* 121 * Convert a character device number to a block device number. 122 */ 123dev_t 124chrtoblk(dev_t dev) 125{ 126 int blkmaj; 127 128 if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl) 129 return (NODEV); 130 blkmaj = chrtoblktbl[major(dev)]; 131 if (blkmaj == NODEV) 132 return (NODEV); 133 return (makedev(blkmaj, minor(dev))); 134} 135 136/* 137 * Convert a block device number to a character device number. 138 */ 139dev_t 140blktochr(dev_t dev) 141{ 142 int blkmaj = major(dev); 143 int i; 144 145 if (blkmaj >= nblkdev) 146 return (NODEV); 147 for (i = 0; i < nchrtoblktbl; i++) 148 if (blkmaj == chrtoblktbl[i]) 149 return (makedev(i, minor(dev))); 150 return (NODEV); 151} 152 153/* 154 * Check that we're in a context where it's okay to sleep. 155 */ 156void 157assertwaitok(void) 158{ 159 if (panicstr || db_active) 160 return; 161 162 splassert(IPL_NONE); 163 SMR_ASSERT_NONCRITICAL(); 164#ifdef DIAGNOSTIC 165 if (curcpu()->ci_mutex_level != 0) 166 panic("assertwaitok: non-zero mutex count: %d", 167 curcpu()->ci_mutex_level); 168#endif 169} 170