| 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 | * $FreeBSD: src/sys/kern/kern_conf.c,v 1.73.2.3 2003/03/10 02:18:25 imp Exp $ |
| 34 | * $DragonFly: src/sys/kern/kern_conf.c,v 1.23 2007/05/09 00:53:34 dillon Exp $ |
| 35 | */ |
| 36 | |
| 37 | #include <sys/param.h> |
| 38 | #include <sys/kernel.h> |
| 39 | #include <sys/sysctl.h> |
| 40 | #include <sys/systm.h> |
| 41 | #include <sys/module.h> |
| 42 | #include <sys/malloc.h> |
| 43 | #include <sys/conf.h> |
| 44 | #include <sys/vnode.h> |
| 45 | #include <sys/queue.h> |
| 46 | #include <sys/device.h> |
| 47 | #include <sys/disk.h> |
| 48 | #include <machine/stdarg.h> |
| 49 | |
| 50 | #include <sys/sysref2.h> |
| 51 | |
| 52 | #include <sys/devfs.h> |
| 53 | |
| 54 | MALLOC_DEFINE(M_DEVT, "cdev_t", "dev_t storage"); |
| 55 | |
| 56 | static int free_devt; |
| 57 | SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); |
| 58 | int dev_ref_debug = 0; |
| 59 | SYSCTL_INT(_debug, OID_AUTO, dev_refs, CTLFLAG_RW, &dev_ref_debug, 0, ""); |
| 60 | |
| 61 | /* |
| 62 | * cdev_t and u_dev_t primitives. Note that the major number is always |
| 63 | * extracted from si_umajor, not from si_devsw, because si_devsw is replaced |
| 64 | * when a device is destroyed. |
| 65 | */ |
| 66 | int |
| 67 | major(cdev_t dev) |
| 68 | { |
| 69 | if (dev == NULL) |
| 70 | return NOUDEV; |
| 71 | return(dev->si_umajor); |
| 72 | } |
| 73 | |
| 74 | int |
| 75 | minor(cdev_t dev) |
| 76 | { |
| 77 | if (dev == NULL) |
| 78 | return NOUDEV; |
| 79 | return(dev->si_uminor); |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * Compatibility function with old udev_t format to convert the |
| 84 | * non-consecutive minor space into a consecutive minor space. |
| 85 | */ |
| 86 | int |
| 87 | lminor(cdev_t dev) |
| 88 | { |
| 89 | int y; |
| 90 | |
| 91 | if (dev == NULL) |
| 92 | return NOUDEV; |
| 93 | y = dev->si_uminor; |
| 94 | if (y & 0x0000ff00) |
| 95 | return NOUDEV; |
| 96 | return ((y & 0xff) | (y >> 8)); |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Convert a device pointer to an old style device number. Return NOUDEV |
| 101 | * if the device is invalid or if the device (maj,min) cannot be converted |
| 102 | * to an old style udev_t. |
| 103 | */ |
| 104 | udev_t |
| 105 | dev2udev(cdev_t dev) |
| 106 | { |
| 107 | if (dev == NULL) |
| 108 | return NOUDEV; |
| 109 | |
| 110 | return (udev_t)dev->si_inode; |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * Convert a device number to a device pointer. The device is referenced |
| 115 | * ad-hoc, meaning that the caller should call reference_dev() if it wishes |
| 116 | * to keep ahold of the returned structure long term. |
| 117 | * |
| 118 | * The returned device is associated with the currently installed cdevsw |
| 119 | * for the requested major number. NULL is returned if the major number |
| 120 | * has not been registered. |
| 121 | */ |
| 122 | cdev_t |
| 123 | udev2dev(udev_t x, int b) |
| 124 | { |
| 125 | if (x == NOUDEV || b != 0) |
| 126 | return(NULL); |
| 127 | |
| 128 | return devfs_find_device_by_udev(x); |
| 129 | } |
| 130 | |
| 131 | int |
| 132 | dev_is_good(cdev_t dev) |
| 133 | { |
| 134 | if (dev != NULL && dev->si_ops != &dead_dev_ops) |
| 135 | return(1); |
| 136 | return(0); |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Various user device number extraction and conversion routines |
| 141 | */ |
| 142 | int |
| 143 | uminor(udev_t dev) |
| 144 | { |
| 145 | if (dev == NOUDEV) |
| 146 | return(-1); |
| 147 | return(dev & 0xffff00ff); |
| 148 | } |
| 149 | |
| 150 | int |
| 151 | umajor(udev_t dev) |
| 152 | { |
| 153 | if (dev == NOUDEV) |
| 154 | return(-1); |
| 155 | return((dev & 0xff00) >> 8); |
| 156 | } |
| 157 | |
| 158 | udev_t |
| 159 | makeudev(int x, int y) |
| 160 | { |
| 161 | if ((x & 0xffffff00) || (y & 0x0000ff00)) |
| 162 | return NOUDEV; |
| 163 | return ((x << 8) | y); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * Create an internal or external device. |
| 168 | * |
| 169 | * This routine creates and returns an unreferenced ad-hoc entry for the |
| 170 | * device which will remain intact until the device is destroyed. If the |
| 171 | * caller intends to store the device pointer it must call reference_dev() |
| 172 | * to retain a real reference to the device. |
| 173 | * |
| 174 | * If an entry already exists, this function will set (or override) |
| 175 | * its cred requirements and name (XXX DEVFS interface). |
| 176 | */ |
| 177 | cdev_t |
| 178 | make_dev(struct dev_ops *ops, int minor, uid_t uid, gid_t gid, |
| 179 | int perms, const char *fmt, ...) |
| 180 | { |
| 181 | cdev_t devfs_dev; |
| 182 | __va_list ap; |
| 183 | |
| 184 | /* |
| 185 | * compile the cdevsw and install the device |
| 186 | */ |
| 187 | compile_dev_ops(ops); |
| 188 | |
| 189 | devfs_dev = devfs_new_cdev(ops, minor, NULL); |
| 190 | __va_start(ap, fmt); |
| 191 | kvsnrprintf(devfs_dev->si_name, sizeof(devfs_dev->si_name), |
| 192 | 32, fmt, ap); |
| 193 | __va_end(ap); |
| 194 | |
| 195 | devfs_debug(DEVFS_DEBUG_INFO, |
| 196 | "make_dev called for %s\n", |
| 197 | devfs_dev->si_name); |
| 198 | devfs_create_dev(devfs_dev, uid, gid, perms); |
| 199 | |
| 200 | return (devfs_dev); |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * make_dev_covering has equivalent functionality to make_dev, except that it |
| 205 | * also takes the cdev of the underlying device. Hence this function should |
| 206 | * only be used by systems and drivers which create devices covering others |
| 207 | */ |
| 208 | cdev_t |
| 209 | make_dev_covering(struct dev_ops *ops, struct dev_ops *bops, int minor, |
| 210 | uid_t uid, gid_t gid, int perms, const char *fmt, ...) |
| 211 | { |
| 212 | cdev_t devfs_dev; |
| 213 | __va_list ap; |
| 214 | |
| 215 | /* |
| 216 | * compile the cdevsw and install the device |
| 217 | */ |
| 218 | compile_dev_ops(ops); |
| 219 | |
| 220 | devfs_dev = devfs_new_cdev(ops, minor, bops); |
| 221 | __va_start(ap, fmt); |
| 222 | kvsnrprintf(devfs_dev->si_name, sizeof(devfs_dev->si_name), |
| 223 | 32, fmt, ap); |
| 224 | __va_end(ap); |
| 225 | |
| 226 | devfs_debug(DEVFS_DEBUG_INFO, |
| 227 | "make_dev called for %s\n", |
| 228 | devfs_dev->si_name); |
| 229 | devfs_create_dev(devfs_dev, uid, gid, perms); |
| 230 | |
| 231 | return (devfs_dev); |
| 232 | } |
| 233 | |
| 234 | |
| 235 | |
| 236 | cdev_t |
| 237 | make_only_devfs_dev(struct dev_ops *ops, int minor, uid_t uid, gid_t gid, |
| 238 | int perms, const char *fmt, ...) |
| 239 | { |
| 240 | cdev_t devfs_dev; |
| 241 | __va_list ap; |
| 242 | |
| 243 | /* |
| 244 | * compile the cdevsw and install the device |
| 245 | */ |
| 246 | compile_dev_ops(ops); |
| 247 | devfs_dev = devfs_new_cdev(ops, minor, NULL); |
| 248 | |
| 249 | /* |
| 250 | * Set additional fields (XXX DEVFS interface goes here) |
| 251 | */ |
| 252 | __va_start(ap, fmt); |
| 253 | kvsnrprintf(devfs_dev->si_name, sizeof(devfs_dev->si_name), |
| 254 | 32, fmt, ap); |
| 255 | __va_end(ap); |
| 256 | |
| 257 | devfs_create_dev(devfs_dev, uid, gid, perms); |
| 258 | |
| 259 | return (devfs_dev); |
| 260 | } |
| 261 | |
| 262 | |
| 263 | cdev_t |
| 264 | make_only_dev(struct dev_ops *ops, int minor, uid_t uid, gid_t gid, |
| 265 | int perms, const char *fmt, ...) |
| 266 | { |
| 267 | cdev_t devfs_dev; |
| 268 | __va_list ap; |
| 269 | |
| 270 | /* |
| 271 | * compile the cdevsw and install the device |
| 272 | */ |
| 273 | compile_dev_ops(ops); |
| 274 | devfs_dev = devfs_new_cdev(ops, minor, NULL); |
| 275 | devfs_dev->si_perms = perms; |
| 276 | devfs_dev->si_uid = uid; |
| 277 | devfs_dev->si_gid = gid; |
| 278 | |
| 279 | /* |
| 280 | * Set additional fields (XXX DEVFS interface goes here) |
| 281 | */ |
| 282 | __va_start(ap, fmt); |
| 283 | kvsnrprintf(devfs_dev->si_name, sizeof(devfs_dev->si_name), |
| 284 | 32, fmt, ap); |
| 285 | __va_end(ap); |
| 286 | |
| 287 | reference_dev(devfs_dev); |
| 288 | |
| 289 | return (devfs_dev); |
| 290 | } |
| 291 | |
| 292 | void |
| 293 | destroy_only_dev(cdev_t dev) |
| 294 | { |
| 295 | release_dev(dev); |
| 296 | release_dev(dev); |
| 297 | release_dev(dev); |
| 298 | } |
| 299 | |
| 300 | /* |
| 301 | * destroy_dev() removes the adhoc association for a device and revectors |
| 302 | * its ops to &dead_dev_ops. |
| 303 | * |
| 304 | * This routine releases the reference count associated with the ADHOC |
| 305 | * entry, plus releases the reference count held by the caller. What this |
| 306 | * means is that you should not call destroy_dev(make_dev(...)), because |
| 307 | * make_dev() does not bump the reference count (beyond what it needs to |
| 308 | * create the ad-hoc association). Any procedure that intends to destroy |
| 309 | * a device must have its own reference to it first. |
| 310 | */ |
| 311 | void |
| 312 | destroy_dev(cdev_t dev) |
| 313 | { |
| 314 | if (dev) { |
| 315 | devfs_debug(DEVFS_DEBUG_DEBUG, |
| 316 | "destroy_dev called for %s\n", |
| 317 | dev->si_name); |
| 318 | devfs_destroy_dev(dev); |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Make sure all asynchronous disk and devfs related operations have |
| 324 | * completed. |
| 325 | * |
| 326 | * Typically called prior to mountroot to ensure that all disks have |
| 327 | * been completely probed and on module unload to ensure that ops |
| 328 | * structures have been dereferenced. |
| 329 | */ |
| 330 | void |
| 331 | sync_devs(void) |
| 332 | { |
| 333 | disk_config(NULL); |
| 334 | devfs_config(); |
| 335 | disk_config(NULL); |
| 336 | devfs_config(); |
| 337 | } |
| 338 | |
| 339 | int |
| 340 | make_dev_alias(cdev_t target, const char *fmt, ...) |
| 341 | { |
| 342 | __va_list ap; |
| 343 | char *name; |
| 344 | |
| 345 | __va_start(ap, fmt); |
| 346 | kvasnrprintf(&name, PATH_MAX, 32, fmt, ap); |
| 347 | __va_end(ap); |
| 348 | |
| 349 | devfs_make_alias(name, target); |
| 350 | kvasfree(&name); |
| 351 | |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | extern struct dev_ops default_dev_ops; |
| 356 | |
| 357 | cdev_t |
| 358 | make_autoclone_dev(struct dev_ops *ops, struct devfs_bitmap *bitmap, |
| 359 | d_clone_t *nhandler, uid_t uid, gid_t gid, int perms, const char *fmt, ...) |
| 360 | { |
| 361 | __va_list ap; |
| 362 | cdev_t dev; |
| 363 | char *name; |
| 364 | |
| 365 | __va_start(ap, fmt); |
| 366 | kvasnrprintf(&name, PATH_MAX, 32, fmt, ap); |
| 367 | __va_end(ap); |
| 368 | |
| 369 | if (bitmap != NULL) |
| 370 | devfs_clone_bitmap_init(bitmap); |
| 371 | |
| 372 | devfs_clone_handler_add(name, nhandler); |
| 373 | dev = make_dev_covering(&default_dev_ops, ops, 0xffff00ff, |
| 374 | uid, gid, perms, "%s", name); |
| 375 | kvasfree(&name); |
| 376 | return dev; |
| 377 | } |
| 378 | |
| 379 | void |
| 380 | destroy_autoclone_dev(cdev_t dev, struct devfs_bitmap *bitmap) |
| 381 | { |
| 382 | if (dev == NULL) |
| 383 | return; |
| 384 | |
| 385 | devfs_clone_handler_del(dev->si_name); |
| 386 | |
| 387 | if (bitmap != NULL) |
| 388 | devfs_clone_bitmap_uninit(bitmap); |
| 389 | |
| 390 | destroy_dev(dev); |
| 391 | } |
| 392 | |
| 393 | |
| 394 | /* |
| 395 | * Add a reference to a device. Callers generally add their own references |
| 396 | * when they are going to store a device node in a variable for long periods |
| 397 | * of time, to prevent a disassociation from free()ing the node. |
| 398 | * |
| 399 | * Also note that a caller that intends to call destroy_dev() must first |
| 400 | * obtain a reference on the device. The ad-hoc reference you get with |
| 401 | * make_dev() and friends is NOT sufficient to be able to call destroy_dev(). |
| 402 | */ |
| 403 | cdev_t |
| 404 | reference_dev(cdev_t dev) |
| 405 | { |
| 406 | //kprintf("reference_dev\n"); |
| 407 | |
| 408 | if (dev != NULL) { |
| 409 | sysref_get(&dev->si_sysref); |
| 410 | if (dev_ref_debug & 2) { |
| 411 | kprintf("reference dev %p %s(minor=%08x) refs=%d\n", |
| 412 | dev, devtoname(dev), dev->si_uminor, |
| 413 | dev->si_sysref.refcnt); |
| 414 | } |
| 415 | } |
| 416 | return(dev); |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * release a reference on a device. The device will be terminated when the |
| 421 | * last reference has been released. |
| 422 | * |
| 423 | * NOTE: we must use si_umajor to figure out the original major number, |
| 424 | * because si_ops could already be pointing at dead_dev_ops. |
| 425 | */ |
| 426 | void |
| 427 | release_dev(cdev_t dev) |
| 428 | { |
| 429 | //kprintf("release_dev\n"); |
| 430 | |
| 431 | if (dev == NULL) |
| 432 | return; |
| 433 | sysref_put(&dev->si_sysref); |
| 434 | } |
| 435 | |
| 436 | const char * |
| 437 | devtoname(cdev_t dev) |
| 438 | { |
| 439 | int mynor; |
| 440 | int len; |
| 441 | char *p; |
| 442 | const char *dname; |
| 443 | |
| 444 | if (dev == NULL) |
| 445 | return("#nodev"); |
| 446 | if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { |
| 447 | p = dev->si_name; |
| 448 | len = sizeof(dev->si_name); |
| 449 | if ((dname = dev_dname(dev)) != NULL) |
| 450 | ksnprintf(p, len, "#%s/", dname); |
| 451 | else |
| 452 | ksnprintf(p, len, "#%d/", major(dev)); |
| 453 | len -= strlen(p); |
| 454 | p += strlen(p); |
| 455 | mynor = minor(dev); |
| 456 | if (mynor < 0 || mynor > 255) |
| 457 | ksnprintf(p, len, "%#x", (u_int)mynor); |
| 458 | else |
| 459 | ksnprintf(p, len, "%d", mynor); |
| 460 | } |
| 461 | return (dev->si_name); |
| 462 | } |
| 463 | |