kern_conf.c revision 71920
1233294Sstas/*- 2233294Sstas * Parts Copyright (c) 1995 Terrence R. Lambert 3233294Sstas * Copyright (c) 1995 Julian R. Elischer 455682Smarkm * All rights reserved. 5233294Sstas * 6233294Sstas * Redistribution and use in source and binary forms, with or without 7233294Sstas * modification, are permitted provided that the following conditions 8120945Snectar * are met: 9233294Sstas * 1. Redistributions of source code must retain the above copyright 10233294Sstas * notice, this list of conditions and the following disclaimer. 11120945Snectar * 2. Redistributions in binary form must reproduce the above copyright 12233294Sstas * notice, this list of conditions and the following disclaimer in the 13233294Sstas * documentation and/or other materials provided with the distribution. 14233294Sstas * 3. All advertising materials mentioning features or use of this software 15120945Snectar * must display the following acknowledgement: 16233294Sstas * This product includes software developed by Terrence R. Lambert. 17233294Sstas * 4. The name Terrence R. Lambert may not be used to endorse or promote 18233294Sstas * products derived from this software without specific prior written 19120945Snectar * permission. 20233294Sstas * 21233294Sstas * THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY 22233294Sstas * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23233294Sstas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24233294Sstas * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE 25233294Sstas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26233294Sstas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27233294Sstas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28233294Sstas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29233294Sstas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30233294Sstas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31120945Snectar * SUCH DAMAGE. 32233294Sstas * 33233294Sstas * $FreeBSD: head/sys/kern/kern_conf.c 71920 2001-02-02 03:32:11Z brian $ 34178825Sdfr */ 3555682Smarkm 3655682Smarkm#include <sys/param.h> 3755682Smarkm#include <sys/kernel.h> 3855682Smarkm#include <sys/sysctl.h> 3976371Sassar#include <sys/systm.h> 4055682Smarkm#include <sys/module.h> 4155682Smarkm#include <sys/malloc.h> 4272445Sassar#include <sys/conf.h> 43233294Sstas#include <sys/vnode.h> 4472445Sassar#include <sys/queue.h> 4572445Sassar#include <sys/ctype.h> 46233294Sstas#include <machine/stdarg.h> 47233294Sstas 48233294Sstas#define cdevsw_ALLOCSTART (NUMCDEVSW/2) 49102644Snectar 5072445Sassarstruct cdevsw *cdevsw[NUMCDEVSW]; 5155682Smarkm 5255682Smarkmstatic MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); 5355682Smarkm 54120945Snectar/* 55120945Snectar * This is the number of hash-buckets. Experiements with 'real-life' 56233294Sstas * udev_t's show that a prime halfway between two powers of two works 57120945Snectar * best. 58120945Snectar */ 59120945Snectar#define DEVT_HASH 83 6055682Smarkm 6155682Smarkm/* The number of dev_t's we can create before malloc(9) kick in. */ 6290926Snectar#define DEVT_STASH 50 63233294Sstas 64233294Sstasstatic struct specinfo devt_stash[DEVT_STASH]; 65233294Sstas 66233294Sstasstatic LIST_HEAD(, specinfo) dev_hash[DEVT_HASH]; 67233294Sstas 6855682Smarkmstatic LIST_HEAD(, specinfo) dev_free; 69178825Sdfr 7090926Snectardevfs_create_t *devfs_create_hook; 7190926Snectardevfs_destroy_t *devfs_destroy_hook; 7290926Snectarint devfs_present; 7390926Snectar 74233294Sstasstatic int free_devt; 75233294SstasSYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); 76233294Sstas 7755682Smarkmstruct cdevsw * 78120945Snectardevsw(dev_t dev) 7955682Smarkm{ 8055682Smarkm if (dev->si_devsw) 8155682Smarkm return (dev->si_devsw); 82233294Sstas return(cdevsw[major(dev)]); 8355682Smarkm} 8455682Smarkm 8555682Smarkm/* 8655682Smarkm * Add a cdevsw entry 87233294Sstas */ 88233294Sstas 89233294Sstasint 90233294Sstascdevsw_add(struct cdevsw *newentry) 91233294Sstas{ 92233294Sstas 9390926Snectar if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) { 9490926Snectar printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 9590926Snectar newentry->d_name, newentry->d_maj); 9690926Snectar return (EINVAL); 9790926Snectar } 9890926Snectar 9990926Snectar if (cdevsw[newentry->d_maj]) { 10090926Snectar printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n", 10190926Snectar newentry->d_name, cdevsw[newentry->d_maj]->d_name); 102233294Sstas } 10355682Smarkm 104233294Sstas cdevsw[newentry->d_maj] = newentry; 105233294Sstas 106233294Sstas return (0); 10755682Smarkm} 10855682Smarkm 109120945Snectar/* 11055682Smarkm * Remove a cdevsw entry 11155682Smarkm */ 112233294Sstas 11390926Snectarint 11490926Snectarcdevsw_remove(struct cdevsw *oldentry) 115102644Snectar{ 11690926Snectar if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) { 117233294Sstas printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 118178825Sdfr oldentry->d_name, oldentry->d_maj); 119178825Sdfr return EINVAL; 120102644Snectar } 121178825Sdfr 12255682Smarkm cdevsw[oldentry->d_maj] = NULL; 12355682Smarkm 12455682Smarkm return 0; 125} 126 127/* 128 * dev_t and u_dev_t primitives 129 */ 130 131int 132major(dev_t x) 133{ 134 if (x == NODEV) 135 return NOUDEV; 136 return((x->si_udev >> 8) & 0xff); 137} 138 139int 140minor(dev_t x) 141{ 142 if (x == NODEV) 143 return NOUDEV; 144 return(x->si_udev & 0xffff00ff); 145} 146 147int 148dev2unit(dev_t x) 149{ 150 int i; 151 152 if (x == NODEV) 153 return NOUDEV; 154 i = minor(x); 155 return ((i & 0xff) | (i >> 8)); 156} 157 158int 159unit2minor(int unit) 160{ 161 162 return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 163} 164 165static dev_t 166allocdev(void) 167{ 168 static int stashed; 169 struct specinfo *si; 170 171 if (stashed >= DEVT_STASH) { 172 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT, 173 M_USE_RESERVE | M_ZERO); 174 } else if (LIST_FIRST(&dev_free)) { 175 si = LIST_FIRST(&dev_free); 176 LIST_REMOVE(si, si_hash); 177 } else { 178 si = devt_stash + stashed++; 179 si->si_flags |= SI_STASHED; 180 } 181 LIST_INIT(&si->si_names); 182 return (si); 183} 184 185dev_t 186makedev(int x, int y) 187{ 188 struct specinfo *si; 189 udev_t udev; 190 int hash; 191 192 if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) 193 panic("makedev of NOUDEV"); 194 udev = (x << 8) | y; 195 hash = udev % DEVT_HASH; 196 LIST_FOREACH(si, &dev_hash[hash], si_hash) { 197 if (si->si_udev == udev) 198 return (si); 199 } 200 si = allocdev(); 201 si->si_udev = udev; 202 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 203 return (si); 204} 205 206void 207freedev(dev_t dev) 208{ 209 dev_t adev; 210 211 if (!free_devt) 212 return; 213 if (SLIST_FIRST(&dev->si_hlist)) 214 return; 215 if (dev->si_devsw || dev->si_drv1 || dev->si_drv2) 216 return; 217 while (!LIST_EMPTY(&dev->si_names)) { 218 adev = LIST_FIRST(&dev->si_names); 219 adev->si_drv1 = NULL; 220 freedev(adev); 221 } 222 LIST_REMOVE(dev, si_hash); 223 if (dev->si_flags & SI_STASHED) { 224 bzero(dev, sizeof(*dev)); 225 LIST_INSERT_HEAD(&dev_free, dev, si_hash); 226 } else { 227 FREE(dev, M_DEVT); 228 } 229} 230 231udev_t 232dev2udev(dev_t x) 233{ 234 if (x == NODEV) 235 return NOUDEV; 236 return (x->si_udev); 237} 238 239dev_t 240udev2dev(udev_t x, int b) 241{ 242 243 if (x == NOUDEV) 244 return (NODEV); 245 switch (b) { 246 case 0: 247 return makedev(umajor(x), uminor(x)); 248 case 1: 249 return (NODEV); 250 default: 251 Debugger("udev2dev(...,X)"); 252 return NODEV; 253 } 254} 255 256int 257uminor(udev_t dev) 258{ 259 return(dev & 0xffff00ff); 260} 261 262int 263umajor(udev_t dev) 264{ 265 return((dev & 0xff00) >> 8); 266} 267 268udev_t 269makeudev(int x, int y) 270{ 271 return ((x << 8) | y); 272} 273 274dev_t 275make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...) 276{ 277 dev_t dev; 278 va_list ap; 279 int i; 280 281 KASSERT(umajor(makeudev(devsw->d_maj, minor)) == devsw->d_maj, 282 ("Invalid minor (%d) in make_dev", minor)); 283 284 dev = makedev(devsw->d_maj, minor); 285 if (dev->si_flags & SI_NAMED) { 286 printf( "WARNING: Driver mistake: repeat make_dev(\"%s\")\n", 287 dev->si_name); 288 return (dev); 289 } 290 va_start(ap, fmt); 291 i = kvprintf(fmt, NULL, dev->si_name, 32, ap); 292 dev->si_name[i] = '\0'; 293 va_end(ap); 294 dev->si_devsw = devsw; 295 dev->si_uid = uid; 296 dev->si_gid = gid; 297 dev->si_mode = perms; 298 dev->si_flags |= SI_NAMED; 299 300 if (devfs_create_hook) 301 devfs_create_hook(dev); 302 return (dev); 303} 304 305dev_t 306make_dev_alias(dev_t pdev, char *fmt, ...) 307{ 308 dev_t dev; 309 va_list ap; 310 int i; 311 312 dev = allocdev(); 313 dev->si_flags |= SI_ALIAS; 314 dev->si_flags |= SI_NAMED; 315 dev->si_drv1 = pdev; 316 LIST_INSERT_HEAD(&pdev->si_names, dev, si_hash); 317 318 va_start(ap, fmt); 319 i = kvprintf(fmt, NULL, dev->si_name, 32, ap); 320 dev->si_name[i] = '\0'; 321 va_end(ap); 322 323 if (devfs_create_hook) 324 devfs_create_hook(dev); 325 return (dev); 326} 327 328void 329destroy_dev(dev_t dev) 330{ 331 332 if (!(dev->si_flags & SI_NAMED)) { 333 printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", 334 major(dev), minor(dev)); 335 return; 336 } 337 338 if (devfs_destroy_hook) 339 devfs_destroy_hook(dev); 340 dev->si_drv1 = 0; 341 dev->si_drv2 = 0; 342 dev->si_devsw = 0; 343 dev->si_flags &= ~SI_NAMED; 344 dev->si_flags &= ~SI_ALIAS; 345 freedev(dev); 346} 347 348const char * 349devtoname(dev_t dev) 350{ 351 char *p; 352 int mynor; 353 354 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 355 p = dev->si_name; 356 if (devsw(dev)) 357 sprintf(p, "#%s/", devsw(dev)->d_name); 358 else 359 sprintf(p, "#%d/", major(dev)); 360 p += strlen(p); 361 mynor = minor(dev); 362 if (mynor < 0 || mynor > 255) 363 sprintf(p, "%#x", (u_int)mynor); 364 else 365 sprintf(p, "%d", mynor); 366 } 367 return (dev->si_name); 368} 369 370int 371dev_stdclone(char *name, char **namep, char *stem, int *unit) 372{ 373 int u, i; 374 375 if (bcmp(stem, name, strlen(stem)) != 0) 376 return (0); 377 i = strlen(stem); 378 if (!isdigit(name[i])) 379 return (0); 380 u = 0; 381 while (isdigit(name[i])) { 382 u *= 10; 383 u += name[i++] - '0'; 384 } 385 *unit = u; 386 if (namep) 387 *namep = &name[i]; 388 if (name[i]) 389 return (2); 390 return (1); 391} 392 393/* 394 * Helper sysctl for devname(3). We're given a {u}dev_t and return 395 * the name, if any, registered by the device driver. 396 */ 397static int 398sysctl_devname(SYSCTL_HANDLER_ARGS) 399{ 400 int error; 401 udev_t ud; 402 dev_t dev; 403 404 error = SYSCTL_IN(req, &ud, sizeof (ud)); 405 if (error) 406 return (error); 407 if (ud == NOUDEV) 408 return(EINVAL); 409 dev = makedev(umajor(ud), uminor(ud)); 410 if (dev->si_name[0] == '\0') 411 error = ENOENT; 412 else 413 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 414 freedev(dev); 415 return (error); 416} 417 418SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 419 NULL, 0, sysctl_devname, "", "devname(3) handler"); 420 421