kern_conf.c revision 50254
1/*- 2 * Parts Copyright (c) 1995 Terrence R. Lambert 3 * Copyright (c) 1995 Julian R. Elischer 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Terrence R. Lambert. 17 * 4. The name Terrence R. Lambert may not be used to endorse or promote 18 * products derived from this software without specific prior written 19 * permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY 22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $Id: kern_conf.c,v 1.59 1999/08/20 20:24:59 julian Exp $ 34 */ 35 36#include <sys/param.h> 37#include <sys/kernel.h> 38#include <sys/systm.h> 39#include <sys/module.h> 40#include <sys/malloc.h> 41#include <sys/conf.h> 42#include <sys/vnode.h> 43#include <sys/queue.h> 44#include <machine/stdarg.h> 45 46#define cdevsw_ALLOCSTART (NUMCDEVSW/2) 47 48struct cdevsw *cdevsw[NUMCDEVSW]; 49 50static int bmaj2cmaj[NUMCDEVSW]; 51 52MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); 53 54#define DEVT_HASH 83 55#define DEVT_STASH 50 56 57static struct specinfo devt_stash[DEVT_STASH]; 58 59static SLIST_HEAD(devt_hash_head, specinfo) dev_hash[DEVT_HASH]; 60 61devfs_create_t *devfs_create_hook; 62 63/* 64 * Routine to convert from character to block device number. 65 * 66 * A minimal stub routine can always return NODEV. 67 */ 68dev_t 69chrtoblk(dev_t dev) 70{ 71 struct cdevsw *cd; 72 73 if((cd = devsw(dev)) != NULL) { 74 if (cd->d_bmaj != -1) 75 return(makebdev(cd->d_bmaj,minor(dev))); 76 } 77 return(NODEV); 78} 79 80struct cdevsw * 81devsw(dev_t dev) 82{ 83 if (dev->si_devsw) 84 return (dev->si_devsw); 85 return(cdevsw[major(dev)]); 86} 87 88/* 89 * Add a cdevsw entry 90 */ 91 92int 93cdevsw_add(struct cdevsw *newentry) 94{ 95 int i; 96 static int setup; 97 98 if (!setup) { 99 for (i = 0; i < NUMCDEVSW; i++) 100 if (!bmaj2cmaj[i]) 101 bmaj2cmaj[i] = 254; 102 setup++; 103 } 104 105 if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) { 106 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 107 newentry->d_name, newentry->d_maj); 108 return EINVAL; 109 } 110 111 if (cdevsw[newentry->d_maj]) { 112 printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n", 113 newentry->d_name, cdevsw[newentry->d_maj]->d_name); 114 } 115 cdevsw[newentry->d_maj] = newentry; 116 117 if (newentry->d_bmaj >= 0 && newentry->d_bmaj < NUMCDEVSW) { 118 if (bmaj2cmaj[newentry->d_bmaj] != 254) { 119 printf("WARNING: \"%s\" is usurping \"%s\"'s bmaj\n", 120 newentry->d_name, 121 cdevsw[bmaj2cmaj[newentry->d_bmaj]]->d_name); 122 } 123 bmaj2cmaj[newentry->d_bmaj] = newentry->d_maj; 124 } 125 126 return 0; 127} 128 129/* 130 * Remove a cdevsw entry 131 */ 132 133int 134cdevsw_remove(struct cdevsw *oldentry) 135{ 136 if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) { 137 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 138 oldentry->d_name, oldentry->d_maj); 139 return EINVAL; 140 } 141 142 cdevsw[oldentry->d_maj] = NULL; 143 144 if (oldentry->d_bmaj >= 0 && oldentry->d_bmaj < NUMCDEVSW) 145 bmaj2cmaj[oldentry->d_bmaj] = 254; 146 147 return 0; 148} 149 150int 151devsw_module_handler(module_t mod, int what, void* arg) 152{ 153 struct devsw_module_data* data = (struct devsw_module_data*) arg; 154 int error = 0; 155 156 switch (what) { 157 case MOD_LOAD: 158 error = cdevsw_add(data->cdevsw); 159 if (!error && data->chainevh) 160 error = data->chainevh(mod, what, data->chainarg); 161 return error; 162 163 case MOD_UNLOAD: 164 if (data->chainevh) { 165 error = data->chainevh(mod, what, data->chainarg); 166 if (error) 167 return error; 168 } 169 cdevsw_remove(data->cdevsw); 170 return error; 171 } 172 173 if (data->chainevh) 174 return data->chainevh(mod, what, data->chainarg); 175 else 176 return 0; 177} 178 179/* 180 * dev_t and u_dev_t primitives 181 */ 182 183int 184major(dev_t x) 185{ 186 if (x == NODEV) 187 return NOUDEV; 188 return((x->si_udev >> 8) & 0xff); 189} 190 191int 192minor(dev_t x) 193{ 194 if (x == NODEV) 195 return NOUDEV; 196 return(x->si_udev & 0xffff00ff); 197} 198 199int 200lminor(dev_t x) 201{ 202 int i; 203 204 if (x == NODEV) 205 return NOUDEV; 206 i = minor(x); 207 return ((i & 0xff) | (i >> 8)); 208} 209 210dev_t 211makebdev(int x, int y) 212{ 213 return (makedev(bmaj2cmaj[x], y)); 214} 215 216dev_t 217makedev(int x, int y) 218{ 219 struct specinfo *si; 220 udev_t udev; 221 int hash; 222 static int stashed; 223 224 udev = (x << 8) | y; 225 hash = udev % DEVT_HASH; 226 SLIST_FOREACH(si, &dev_hash[hash], si_hash) { 227 if (si->si_udev == udev) 228 return (si); 229 } 230 if (stashed >= DEVT_STASH) { 231 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT, 232 M_USE_RESERVE); 233 } else { 234 si = devt_stash + stashed++; 235 } 236 bzero(si, sizeof(*si)); 237 si->si_udev = udev; 238 if (y > 256) 239 sprintf(si->si_name, "#%d/0x%x", x, y); 240 else 241 sprintf(si->si_name, "#%d/%d", x, y); 242 SLIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 243 return (si); 244} 245 246udev_t 247dev2udev(dev_t x) 248{ 249 if (x == NODEV) 250 return NOUDEV; 251 return (x->si_udev); 252} 253 254udev_t 255dev2budev(dev_t x) 256{ 257 if (x == NODEV) 258 return NOUDEV; 259 else 260 return makeudev(devsw(x)->d_bmaj, minor(x)); 261} 262 263dev_t 264udev2dev(udev_t x, int b) 265{ 266 switch (b) { 267 case 0: 268 return makedev(umajor(x), uminor(x)); 269 case 1: 270 return makebdev(umajor(x), uminor(x)); 271 default: 272 Debugger("udev2dev(...,X)"); 273 return NODEV; 274 } 275} 276 277int 278uminor(udev_t dev) 279{ 280 return(dev & 0xffff00ff); 281} 282 283int 284umajor(udev_t dev) 285{ 286 return((dev & 0xff00) >> 8); 287} 288 289udev_t 290makeudev(int x, int y) 291{ 292 return ((x << 8) | y); 293} 294 295dev_t 296make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...) 297{ 298 dev_t dev; 299 va_list ap; 300 int i; 301 302 dev = makedev(devsw->d_maj, minor); 303 va_start(ap, fmt); 304 i = kvprintf(fmt, NULL, dev->si_name, 32, ap); 305 dev->si_name[i] = '\0'; 306 va_end(ap); 307 dev->si_devsw = devsw; 308 309 if (devfs_create_hook) 310 devfs_create_hook(dev, uid, gid, perms); 311 return (dev); 312} 313 314char * 315devtoname(dev_t dev) 316{ 317 318 return (dev->si_name); 319} 320 321