kern_conf.c revision 49826
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 1.56 1999/08/13 10:29:20 phk 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 61/* 62 * Routine to convert from character to block device number. 63 * 64 * A minimal stub routine can always return NODEV. 65 */ 66dev_t 67chrtoblk(dev_t dev) 68{ 69 struct cdevsw *cd; 70 71 if((cd = devsw(dev)) != NULL) { 72 if (cd->d_bmaj != -1) 73 return(makebdev(cd->d_bmaj,minor(dev))); 74 } 75 return(NODEV); 76} 77 78struct cdevsw * 79devsw(dev_t dev) 80{ 81 if (dev->si_devsw) 82 return (dev->si_devsw); 83 return(cdevsw[major(dev)]); 84} 85 86/* 87 * Add a cdevsw entry 88 */ 89 90int 91cdevsw_add(struct cdevsw *newentry) 92{ 93 int i; 94 static int setup; 95 96 if (!setup) { 97 for (i = 0; i < NUMCDEVSW; i++) 98 if (!bmaj2cmaj[i]) 99 bmaj2cmaj[i] = 254; 100 setup++; 101 } 102 103 if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) { 104 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 105 newentry->d_name, newentry->d_maj); 106 return EINVAL; 107 } 108 109 if (cdevsw[newentry->d_maj]) { 110 printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n", 111 newentry->d_name, cdevsw[newentry->d_maj]->d_name); 112 } 113 cdevsw[newentry->d_maj] = newentry; 114 115 if (newentry->d_bmaj >= 0 && newentry->d_bmaj < NUMCDEVSW) { 116 if (bmaj2cmaj[newentry->d_bmaj] != 254) { 117 printf("WARNING: \"%s\" is usurping \"%s\"'s bmaj\n", 118 newentry->d_name, 119 cdevsw[bmaj2cmaj[newentry->d_bmaj]]->d_name); 120 } 121 bmaj2cmaj[newentry->d_bmaj] = newentry->d_maj; 122 } 123 124 return 0; 125} 126 127/* 128 * Remove a cdevsw entry 129 */ 130 131int 132cdevsw_remove(struct cdevsw *oldentry) 133{ 134 if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) { 135 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 136 oldentry->d_name, oldentry->d_maj); 137 return EINVAL; 138 } 139 140 cdevsw[oldentry->d_maj] = NULL; 141 142 if (oldentry->d_bmaj >= 0 && oldentry->d_bmaj < NUMCDEVSW) 143 bmaj2cmaj[oldentry->d_bmaj] = 254; 144 145 return 0; 146} 147 148int 149devsw_module_handler(module_t mod, int what, void* arg) 150{ 151 struct devsw_module_data* data = (struct devsw_module_data*) arg; 152 int error = 0; 153 154 switch (what) { 155 case MOD_LOAD: 156 error = cdevsw_add(data->cdevsw); 157 if (!error && data->chainevh) 158 error = data->chainevh(mod, what, data->chainarg); 159 return error; 160 161 case MOD_UNLOAD: 162 if (data->chainevh) { 163 error = data->chainevh(mod, what, data->chainarg); 164 if (error) 165 return error; 166 } 167 cdevsw_remove(data->cdevsw); 168 return error; 169 } 170 171 if (data->chainevh) 172 return data->chainevh(mod, what, data->chainarg); 173 else 174 return 0; 175} 176 177/* 178 * dev_t and u_dev_t primitives 179 */ 180 181int 182major(dev_t x) 183{ 184 if (x == NODEV) 185 return NOUDEV; 186 return((x->si_udev >> 8) & 0xff); 187} 188 189int 190minor(dev_t x) 191{ 192 if (x == NODEV) 193 return NOUDEV; 194 return(x->si_udev & 0xffff00ff); 195} 196 197int 198lminor(dev_t x) 199{ 200 int i; 201 202 if (x == NODEV) 203 return NOUDEV; 204 i = minor(x); 205 return ((i & 0xff) | (i >> 8)); 206} 207 208dev_t 209makebdev(int x, int y) 210{ 211 return (makedev(bmaj2cmaj[x], y)); 212} 213 214dev_t 215makedev(int x, int y) 216{ 217 struct specinfo *si; 218 udev_t udev; 219 int hash; 220 static int stashed; 221 222 udev = (x << 8) | y; 223 hash = udev % DEVT_HASH; 224 SLIST_FOREACH(si, &dev_hash[hash], si_hash) { 225 if (si->si_udev == udev) 226 return (si); 227 } 228 if (stashed >= DEVT_STASH) { 229 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT, 230 M_USE_RESERVE); 231 } else { 232 si = devt_stash + stashed++; 233 } 234 bzero(si, sizeof(*si)); 235 si->si_udev = udev; 236 si->si_bsize_phys = DEV_BSIZE; 237 si->si_bsize_best = BLKDEV_IOSIZE; 238 si->si_bsize_max = MAXBSIZE; 239 if (y > 256) 240 sprintf(si->si_name, "#%d/0x%x", x, y); 241 else 242 sprintf(si->si_name, "#%d/%d", x, y); 243 SLIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 244 return (si); 245} 246 247udev_t 248dev2udev(dev_t x) 249{ 250 if (x == NODEV) 251 return NOUDEV; 252 return (x->si_udev); 253} 254 255udev_t 256dev2budev(dev_t x) 257{ 258 if (x == NODEV) 259 return NOUDEV; 260 else 261 return makeudev(devsw(x)->d_bmaj, minor(x)); 262} 263 264dev_t 265udev2dev(udev_t x, int b) 266{ 267 switch (b) { 268 case 0: 269 return makedev(umajor(x), uminor(x)); 270 case 1: 271 return makebdev(umajor(x), uminor(x)); 272 default: 273 Debugger("udev2dev(...,X)"); 274 return NODEV; 275 } 276} 277 278int 279uminor(udev_t dev) 280{ 281 return(dev & 0xffff00ff); 282} 283 284int 285umajor(udev_t dev) 286{ 287 return((dev & 0xff00) >> 8); 288} 289 290udev_t 291makeudev(int x, int y) 292{ 293 return ((x << 8) | y); 294} 295 296dev_t 297make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...) 298{ 299 dev_t dev; 300 va_list ap; 301 int i; 302 303 dev = makedev(devsw->d_maj, minor); 304 va_start(ap, fmt); 305 i = kvprintf(fmt, NULL, dev->si_name, 32, ap); 306 dev->si_name[i] = '\0'; 307 va_end(ap); 308 dev->si_devsw = devsw; 309 return (dev); 310} 311 312