| 1 | /* $NetBSD: subr_devsw.c,v 1.34 2016/02/01 05:05:43 riz Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2001, 2002, 2007, 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by MAEKAWA Masahide <gehenna@NetBSD.org>, and by Andrew Doran. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * Overview |
| 34 | * |
| 35 | * subr_devsw.c: registers device drivers by name and by major |
| 36 | * number, and provides wrapper methods for performing I/O and |
| 37 | * other tasks on device drivers, keying on the device number |
| 38 | * (dev_t). |
| 39 | * |
| 40 | * When the system is built, the config(8) command generates |
| 41 | * static tables of device drivers built into the kernel image |
| 42 | * along with their associated methods. These are recorded in |
| 43 | * the cdevsw0 and bdevsw0 tables. Drivers can also be added to |
| 44 | * and removed from the system dynamically. |
| 45 | * |
| 46 | * Allocation |
| 47 | * |
| 48 | * When the system initially boots only the statically allocated |
| 49 | * indexes (bdevsw0, cdevsw0) are used. If these overflow due to |
| 50 | * allocation, we allocate a fixed block of memory to hold the new, |
| 51 | * expanded index. This "fork" of the table is only ever performed |
| 52 | * once in order to guarantee that other threads may safely access |
| 53 | * the device tables: |
| 54 | * |
| 55 | * o Once a thread has a "reference" to the table via an earlier |
| 56 | * open() call, we know that the entry in the table must exist |
| 57 | * and so it is safe to access it. |
| 58 | * |
| 59 | * o Regardless of whether other threads see the old or new |
| 60 | * pointers, they will point to a correct device switch |
| 61 | * structure for the operation being performed. |
| 62 | * |
| 63 | * XXX Currently, the wrapper methods such as cdev_read() verify |
| 64 | * that a device driver does in fact exist before calling the |
| 65 | * associated driver method. This should be changed so that |
| 66 | * once the device is has been referenced by a vnode (opened), |
| 67 | * calling the other methods should be valid until that reference |
| 68 | * is dropped. |
| 69 | */ |
| 70 | |
| 71 | #include <sys/cdefs.h> |
| 72 | __KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.34 2016/02/01 05:05:43 riz Exp $" ); |
| 73 | |
| 74 | #ifdef _KERNEL_OPT |
| 75 | #include "opt_dtrace.h" |
| 76 | #endif |
| 77 | |
| 78 | #include <sys/param.h> |
| 79 | #include <sys/conf.h> |
| 80 | #include <sys/kmem.h> |
| 81 | #include <sys/systm.h> |
| 82 | #include <sys/poll.h> |
| 83 | #include <sys/tty.h> |
| 84 | #include <sys/cpu.h> |
| 85 | #include <sys/buf.h> |
| 86 | #include <sys/reboot.h> |
| 87 | #include <sys/sdt.h> |
| 88 | |
| 89 | #ifdef DEVSW_DEBUG |
| 90 | #define DPRINTF(x) printf x |
| 91 | #else /* DEVSW_DEBUG */ |
| 92 | #define DPRINTF(x) |
| 93 | #endif /* DEVSW_DEBUG */ |
| 94 | |
| 95 | #define MAXDEVSW 512 /* the maximum of major device number */ |
| 96 | #define BDEVSW_SIZE (sizeof(struct bdevsw *)) |
| 97 | #define CDEVSW_SIZE (sizeof(struct cdevsw *)) |
| 98 | #define DEVSWCONV_SIZE (sizeof(struct devsw_conv)) |
| 99 | |
| 100 | extern const struct bdevsw **bdevsw, *bdevsw0[]; |
| 101 | extern const struct cdevsw **cdevsw, *cdevsw0[]; |
| 102 | extern struct devsw_conv *devsw_conv, devsw_conv0[]; |
| 103 | extern const int sys_bdevsws, sys_cdevsws; |
| 104 | extern int max_bdevsws, max_cdevsws, max_devsw_convs; |
| 105 | |
| 106 | static int bdevsw_attach(const struct bdevsw *, devmajor_t *); |
| 107 | static int cdevsw_attach(const struct cdevsw *, devmajor_t *); |
| 108 | static void devsw_detach_locked(const struct bdevsw *, const struct cdevsw *); |
| 109 | |
| 110 | kmutex_t device_lock; |
| 111 | |
| 112 | void (*biodone_vfs)(buf_t *) = (void *)nullop; |
| 113 | |
| 114 | void |
| 115 | devsw_init(void) |
| 116 | { |
| 117 | |
| 118 | KASSERT(sys_bdevsws < MAXDEVSW - 1); |
| 119 | KASSERT(sys_cdevsws < MAXDEVSW - 1); |
| 120 | mutex_init(&device_lock, MUTEX_DEFAULT, IPL_NONE); |
| 121 | } |
| 122 | |
| 123 | int |
| 124 | devsw_attach(const char *devname, |
| 125 | const struct bdevsw *bdev, devmajor_t *bmajor, |
| 126 | const struct cdevsw *cdev, devmajor_t *cmajor) |
| 127 | { |
| 128 | struct devsw_conv *conv; |
| 129 | char *name; |
| 130 | int error, i; |
| 131 | size_t len; |
| 132 | |
| 133 | if (devname == NULL || cdev == NULL) |
| 134 | return (EINVAL); |
| 135 | |
| 136 | mutex_enter(&device_lock); |
| 137 | |
| 138 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 139 | conv = &devsw_conv[i]; |
| 140 | if (conv->d_name == NULL || strcmp(devname, conv->d_name) != 0) |
| 141 | continue; |
| 142 | |
| 143 | if (*bmajor < 0) |
| 144 | *bmajor = conv->d_bmajor; |
| 145 | if (*cmajor < 0) |
| 146 | *cmajor = conv->d_cmajor; |
| 147 | |
| 148 | if (*bmajor != conv->d_bmajor || *cmajor != conv->d_cmajor) { |
| 149 | error = EINVAL; |
| 150 | goto fail; |
| 151 | } |
| 152 | if ((*bmajor >= 0 && bdev == NULL) || *cmajor < 0) { |
| 153 | error = EINVAL; |
| 154 | goto fail; |
| 155 | } |
| 156 | |
| 157 | if ((*bmajor >= 0 && bdevsw[*bmajor] != NULL) || |
| 158 | cdevsw[*cmajor] != NULL) { |
| 159 | error = EEXIST; |
| 160 | goto fail; |
| 161 | } |
| 162 | |
| 163 | if (bdev != NULL) |
| 164 | bdevsw[*bmajor] = bdev; |
| 165 | cdevsw[*cmajor] = cdev; |
| 166 | |
| 167 | mutex_exit(&device_lock); |
| 168 | return (0); |
| 169 | } |
| 170 | |
| 171 | error = bdevsw_attach(bdev, bmajor); |
| 172 | if (error != 0) |
| 173 | goto fail; |
| 174 | error = cdevsw_attach(cdev, cmajor); |
| 175 | if (error != 0) { |
| 176 | devsw_detach_locked(bdev, NULL); |
| 177 | goto fail; |
| 178 | } |
| 179 | |
| 180 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 181 | if (devsw_conv[i].d_name == NULL) |
| 182 | break; |
| 183 | } |
| 184 | if (i == max_devsw_convs) { |
| 185 | struct devsw_conv *newptr; |
| 186 | int old_convs, new_convs; |
| 187 | |
| 188 | old_convs = max_devsw_convs; |
| 189 | new_convs = old_convs + 1; |
| 190 | |
| 191 | newptr = kmem_zalloc(new_convs * DEVSWCONV_SIZE, KM_NOSLEEP); |
| 192 | if (newptr == NULL) { |
| 193 | devsw_detach_locked(bdev, cdev); |
| 194 | error = ENOMEM; |
| 195 | goto fail; |
| 196 | } |
| 197 | newptr[old_convs].d_name = NULL; |
| 198 | newptr[old_convs].d_bmajor = -1; |
| 199 | newptr[old_convs].d_cmajor = -1; |
| 200 | memcpy(newptr, devsw_conv, old_convs * DEVSWCONV_SIZE); |
| 201 | if (devsw_conv != devsw_conv0) |
| 202 | kmem_free(devsw_conv, old_convs * DEVSWCONV_SIZE); |
| 203 | devsw_conv = newptr; |
| 204 | max_devsw_convs = new_convs; |
| 205 | } |
| 206 | |
| 207 | len = strlen(devname) + 1; |
| 208 | name = kmem_alloc(len, KM_NOSLEEP); |
| 209 | if (name == NULL) { |
| 210 | devsw_detach_locked(bdev, cdev); |
| 211 | error = ENOMEM; |
| 212 | goto fail; |
| 213 | } |
| 214 | strlcpy(name, devname, len); |
| 215 | |
| 216 | devsw_conv[i].d_name = name; |
| 217 | devsw_conv[i].d_bmajor = *bmajor; |
| 218 | devsw_conv[i].d_cmajor = *cmajor; |
| 219 | |
| 220 | mutex_exit(&device_lock); |
| 221 | return (0); |
| 222 | fail: |
| 223 | mutex_exit(&device_lock); |
| 224 | return (error); |
| 225 | } |
| 226 | |
| 227 | static int |
| 228 | bdevsw_attach(const struct bdevsw *devsw, devmajor_t *devmajor) |
| 229 | { |
| 230 | const struct bdevsw **newptr; |
| 231 | devmajor_t bmajor; |
| 232 | int i; |
| 233 | |
| 234 | KASSERT(mutex_owned(&device_lock)); |
| 235 | |
| 236 | if (devsw == NULL) |
| 237 | return (0); |
| 238 | |
| 239 | if (*devmajor < 0) { |
| 240 | for (bmajor = sys_bdevsws ; bmajor < max_bdevsws ; bmajor++) { |
| 241 | if (bdevsw[bmajor] != NULL) |
| 242 | continue; |
| 243 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 244 | if (devsw_conv[i].d_bmajor == bmajor) |
| 245 | break; |
| 246 | } |
| 247 | if (i != max_devsw_convs) |
| 248 | continue; |
| 249 | break; |
| 250 | } |
| 251 | *devmajor = bmajor; |
| 252 | } |
| 253 | |
| 254 | if (*devmajor >= MAXDEVSW) { |
| 255 | printf("bdevsw_attach: block majors exhausted" ); |
| 256 | return (ENOMEM); |
| 257 | } |
| 258 | |
| 259 | if (*devmajor >= max_bdevsws) { |
| 260 | KASSERT(bdevsw == bdevsw0); |
| 261 | newptr = kmem_zalloc(MAXDEVSW * BDEVSW_SIZE, KM_NOSLEEP); |
| 262 | if (newptr == NULL) |
| 263 | return (ENOMEM); |
| 264 | memcpy(newptr, bdevsw, max_bdevsws * BDEVSW_SIZE); |
| 265 | bdevsw = newptr; |
| 266 | max_bdevsws = MAXDEVSW; |
| 267 | } |
| 268 | |
| 269 | if (bdevsw[*devmajor] != NULL) |
| 270 | return (EEXIST); |
| 271 | |
| 272 | bdevsw[*devmajor] = devsw; |
| 273 | |
| 274 | return (0); |
| 275 | } |
| 276 | |
| 277 | static int |
| 278 | cdevsw_attach(const struct cdevsw *devsw, devmajor_t *devmajor) |
| 279 | { |
| 280 | const struct cdevsw **newptr; |
| 281 | devmajor_t cmajor; |
| 282 | int i; |
| 283 | |
| 284 | KASSERT(mutex_owned(&device_lock)); |
| 285 | |
| 286 | if (*devmajor < 0) { |
| 287 | for (cmajor = sys_cdevsws ; cmajor < max_cdevsws ; cmajor++) { |
| 288 | if (cdevsw[cmajor] != NULL) |
| 289 | continue; |
| 290 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 291 | if (devsw_conv[i].d_cmajor == cmajor) |
| 292 | break; |
| 293 | } |
| 294 | if (i != max_devsw_convs) |
| 295 | continue; |
| 296 | break; |
| 297 | } |
| 298 | *devmajor = cmajor; |
| 299 | } |
| 300 | |
| 301 | if (*devmajor >= MAXDEVSW) { |
| 302 | printf("cdevsw_attach: character majors exhausted" ); |
| 303 | return (ENOMEM); |
| 304 | } |
| 305 | |
| 306 | if (*devmajor >= max_cdevsws) { |
| 307 | KASSERT(cdevsw == cdevsw0); |
| 308 | newptr = kmem_zalloc(MAXDEVSW * CDEVSW_SIZE, KM_NOSLEEP); |
| 309 | if (newptr == NULL) |
| 310 | return (ENOMEM); |
| 311 | memcpy(newptr, cdevsw, max_cdevsws * CDEVSW_SIZE); |
| 312 | cdevsw = newptr; |
| 313 | max_cdevsws = MAXDEVSW; |
| 314 | } |
| 315 | |
| 316 | if (cdevsw[*devmajor] != NULL) |
| 317 | return (EEXIST); |
| 318 | |
| 319 | cdevsw[*devmajor] = devsw; |
| 320 | |
| 321 | return (0); |
| 322 | } |
| 323 | |
| 324 | static void |
| 325 | devsw_detach_locked(const struct bdevsw *bdev, const struct cdevsw *cdev) |
| 326 | { |
| 327 | int i; |
| 328 | |
| 329 | KASSERT(mutex_owned(&device_lock)); |
| 330 | |
| 331 | if (bdev != NULL) { |
| 332 | for (i = 0 ; i < max_bdevsws ; i++) { |
| 333 | if (bdevsw[i] != bdev) |
| 334 | continue; |
| 335 | bdevsw[i] = NULL; |
| 336 | break; |
| 337 | } |
| 338 | } |
| 339 | if (cdev != NULL) { |
| 340 | for (i = 0 ; i < max_cdevsws ; i++) { |
| 341 | if (cdevsw[i] != cdev) |
| 342 | continue; |
| 343 | cdevsw[i] = NULL; |
| 344 | break; |
| 345 | } |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | int |
| 350 | devsw_detach(const struct bdevsw *bdev, const struct cdevsw *cdev) |
| 351 | { |
| 352 | |
| 353 | mutex_enter(&device_lock); |
| 354 | devsw_detach_locked(bdev, cdev); |
| 355 | mutex_exit(&device_lock); |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | /* |
| 360 | * Look up a block device by number. |
| 361 | * |
| 362 | * => Caller must ensure that the device is attached. |
| 363 | */ |
| 364 | const struct bdevsw * |
| 365 | bdevsw_lookup(dev_t dev) |
| 366 | { |
| 367 | devmajor_t bmajor; |
| 368 | |
| 369 | if (dev == NODEV) |
| 370 | return (NULL); |
| 371 | bmajor = major(dev); |
| 372 | if (bmajor < 0 || bmajor >= max_bdevsws) |
| 373 | return (NULL); |
| 374 | |
| 375 | return (bdevsw[bmajor]); |
| 376 | } |
| 377 | |
| 378 | /* |
| 379 | * Look up a character device by number. |
| 380 | * |
| 381 | * => Caller must ensure that the device is attached. |
| 382 | */ |
| 383 | const struct cdevsw * |
| 384 | cdevsw_lookup(dev_t dev) |
| 385 | { |
| 386 | devmajor_t cmajor; |
| 387 | |
| 388 | if (dev == NODEV) |
| 389 | return (NULL); |
| 390 | cmajor = major(dev); |
| 391 | if (cmajor < 0 || cmajor >= max_cdevsws) |
| 392 | return (NULL); |
| 393 | |
| 394 | return (cdevsw[cmajor]); |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Look up a block device by reference to its operations set. |
| 399 | * |
| 400 | * => Caller must ensure that the device is not detached, and therefore |
| 401 | * that the returned major is still valid when dereferenced. |
| 402 | */ |
| 403 | devmajor_t |
| 404 | bdevsw_lookup_major(const struct bdevsw *bdev) |
| 405 | { |
| 406 | devmajor_t bmajor; |
| 407 | |
| 408 | for (bmajor = 0 ; bmajor < max_bdevsws ; bmajor++) { |
| 409 | if (bdevsw[bmajor] == bdev) |
| 410 | return (bmajor); |
| 411 | } |
| 412 | |
| 413 | return (NODEVMAJOR); |
| 414 | } |
| 415 | |
| 416 | /* |
| 417 | * Look up a character device by reference to its operations set. |
| 418 | * |
| 419 | * => Caller must ensure that the device is not detached, and therefore |
| 420 | * that the returned major is still valid when dereferenced. |
| 421 | */ |
| 422 | devmajor_t |
| 423 | cdevsw_lookup_major(const struct cdevsw *cdev) |
| 424 | { |
| 425 | devmajor_t cmajor; |
| 426 | |
| 427 | for (cmajor = 0 ; cmajor < max_cdevsws ; cmajor++) { |
| 428 | if (cdevsw[cmajor] == cdev) |
| 429 | return (cmajor); |
| 430 | } |
| 431 | |
| 432 | return (NODEVMAJOR); |
| 433 | } |
| 434 | |
| 435 | /* |
| 436 | * Convert from block major number to name. |
| 437 | * |
| 438 | * => Caller must ensure that the device is not detached, and therefore |
| 439 | * that the name pointer is still valid when dereferenced. |
| 440 | */ |
| 441 | const char * |
| 442 | devsw_blk2name(devmajor_t bmajor) |
| 443 | { |
| 444 | const char *name; |
| 445 | devmajor_t cmajor; |
| 446 | int i; |
| 447 | |
| 448 | name = NULL; |
| 449 | cmajor = -1; |
| 450 | |
| 451 | mutex_enter(&device_lock); |
| 452 | if (bmajor < 0 || bmajor >= max_bdevsws || bdevsw[bmajor] == NULL) { |
| 453 | mutex_exit(&device_lock); |
| 454 | return (NULL); |
| 455 | } |
| 456 | for (i = 0 ; i < max_devsw_convs; i++) { |
| 457 | if (devsw_conv[i].d_bmajor == bmajor) { |
| 458 | cmajor = devsw_conv[i].d_cmajor; |
| 459 | break; |
| 460 | } |
| 461 | } |
| 462 | if (cmajor >= 0 && cmajor < max_cdevsws && cdevsw[cmajor] != NULL) |
| 463 | name = devsw_conv[i].d_name; |
| 464 | mutex_exit(&device_lock); |
| 465 | |
| 466 | return (name); |
| 467 | } |
| 468 | |
| 469 | /* |
| 470 | * Convert char major number to device driver name. |
| 471 | */ |
| 472 | const char * |
| 473 | cdevsw_getname(devmajor_t major) |
| 474 | { |
| 475 | const char *name; |
| 476 | int i; |
| 477 | |
| 478 | name = NULL; |
| 479 | |
| 480 | if (major < 0) |
| 481 | return (NULL); |
| 482 | |
| 483 | mutex_enter(&device_lock); |
| 484 | for (i = 0 ; i < max_devsw_convs; i++) { |
| 485 | if (devsw_conv[i].d_cmajor == major) { |
| 486 | name = devsw_conv[i].d_name; |
| 487 | break; |
| 488 | } |
| 489 | } |
| 490 | mutex_exit(&device_lock); |
| 491 | return (name); |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * Convert block major number to device driver name. |
| 496 | */ |
| 497 | const char * |
| 498 | bdevsw_getname(devmajor_t major) |
| 499 | { |
| 500 | const char *name; |
| 501 | int i; |
| 502 | |
| 503 | name = NULL; |
| 504 | |
| 505 | if (major < 0) |
| 506 | return (NULL); |
| 507 | |
| 508 | mutex_enter(&device_lock); |
| 509 | for (i = 0 ; i < max_devsw_convs; i++) { |
| 510 | if (devsw_conv[i].d_bmajor == major) { |
| 511 | name = devsw_conv[i].d_name; |
| 512 | break; |
| 513 | } |
| 514 | } |
| 515 | mutex_exit(&device_lock); |
| 516 | return (name); |
| 517 | } |
| 518 | |
| 519 | /* |
| 520 | * Convert from device name to block major number. |
| 521 | * |
| 522 | * => Caller must ensure that the device is not detached, and therefore |
| 523 | * that the major number is still valid when dereferenced. |
| 524 | */ |
| 525 | devmajor_t |
| 526 | devsw_name2blk(const char *name, char *devname, size_t devnamelen) |
| 527 | { |
| 528 | struct devsw_conv *conv; |
| 529 | devmajor_t bmajor; |
| 530 | int i; |
| 531 | |
| 532 | if (name == NULL) |
| 533 | return (NODEVMAJOR); |
| 534 | |
| 535 | mutex_enter(&device_lock); |
| 536 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 537 | size_t len; |
| 538 | |
| 539 | conv = &devsw_conv[i]; |
| 540 | if (conv->d_name == NULL) |
| 541 | continue; |
| 542 | len = strlen(conv->d_name); |
| 543 | if (strncmp(conv->d_name, name, len) != 0) |
| 544 | continue; |
| 545 | if (*(name +len) && !isdigit(*(name + len))) |
| 546 | continue; |
| 547 | bmajor = conv->d_bmajor; |
| 548 | if (bmajor < 0 || bmajor >= max_bdevsws || |
| 549 | bdevsw[bmajor] == NULL) |
| 550 | break; |
| 551 | if (devname != NULL) { |
| 552 | #ifdef DEVSW_DEBUG |
| 553 | if (strlen(conv->d_name) >= devnamelen) |
| 554 | printf("devsw_name2blk: too short buffer" ); |
| 555 | #endif /* DEVSW_DEBUG */ |
| 556 | strncpy(devname, conv->d_name, devnamelen); |
| 557 | devname[devnamelen - 1] = '\0'; |
| 558 | } |
| 559 | mutex_exit(&device_lock); |
| 560 | return (bmajor); |
| 561 | } |
| 562 | |
| 563 | mutex_exit(&device_lock); |
| 564 | return (NODEVMAJOR); |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * Convert from device name to char major number. |
| 569 | * |
| 570 | * => Caller must ensure that the device is not detached, and therefore |
| 571 | * that the major number is still valid when dereferenced. |
| 572 | */ |
| 573 | devmajor_t |
| 574 | devsw_name2chr(const char *name, char *devname, size_t devnamelen) |
| 575 | { |
| 576 | struct devsw_conv *conv; |
| 577 | devmajor_t cmajor; |
| 578 | int i; |
| 579 | |
| 580 | if (name == NULL) |
| 581 | return (NODEVMAJOR); |
| 582 | |
| 583 | mutex_enter(&device_lock); |
| 584 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 585 | size_t len; |
| 586 | |
| 587 | conv = &devsw_conv[i]; |
| 588 | if (conv->d_name == NULL) |
| 589 | continue; |
| 590 | len = strlen(conv->d_name); |
| 591 | if (strncmp(conv->d_name, name, len) != 0) |
| 592 | continue; |
| 593 | if (*(name +len) && !isdigit(*(name + len))) |
| 594 | continue; |
| 595 | cmajor = conv->d_cmajor; |
| 596 | if (cmajor < 0 || cmajor >= max_cdevsws || |
| 597 | cdevsw[cmajor] == NULL) |
| 598 | break; |
| 599 | if (devname != NULL) { |
| 600 | #ifdef DEVSW_DEBUG |
| 601 | if (strlen(conv->d_name) >= devnamelen) |
| 602 | printf("devsw_name2chr: too short buffer" ); |
| 603 | #endif /* DEVSW_DEBUG */ |
| 604 | strncpy(devname, conv->d_name, devnamelen); |
| 605 | devname[devnamelen - 1] = '\0'; |
| 606 | } |
| 607 | mutex_exit(&device_lock); |
| 608 | return (cmajor); |
| 609 | } |
| 610 | |
| 611 | mutex_exit(&device_lock); |
| 612 | return (NODEVMAJOR); |
| 613 | } |
| 614 | |
| 615 | /* |
| 616 | * Convert from character dev_t to block dev_t. |
| 617 | * |
| 618 | * => Caller must ensure that the device is not detached, and therefore |
| 619 | * that the major number is still valid when dereferenced. |
| 620 | */ |
| 621 | dev_t |
| 622 | devsw_chr2blk(dev_t cdev) |
| 623 | { |
| 624 | devmajor_t bmajor, cmajor; |
| 625 | int i; |
| 626 | dev_t rv; |
| 627 | |
| 628 | cmajor = major(cdev); |
| 629 | bmajor = NODEVMAJOR; |
| 630 | rv = NODEV; |
| 631 | |
| 632 | mutex_enter(&device_lock); |
| 633 | if (cmajor < 0 || cmajor >= max_cdevsws || cdevsw[cmajor] == NULL) { |
| 634 | mutex_exit(&device_lock); |
| 635 | return (NODEV); |
| 636 | } |
| 637 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 638 | if (devsw_conv[i].d_cmajor == cmajor) { |
| 639 | bmajor = devsw_conv[i].d_bmajor; |
| 640 | break; |
| 641 | } |
| 642 | } |
| 643 | if (bmajor >= 0 && bmajor < max_bdevsws && bdevsw[bmajor] != NULL) |
| 644 | rv = makedev(bmajor, minor(cdev)); |
| 645 | mutex_exit(&device_lock); |
| 646 | |
| 647 | return (rv); |
| 648 | } |
| 649 | |
| 650 | /* |
| 651 | * Convert from block dev_t to character dev_t. |
| 652 | * |
| 653 | * => Caller must ensure that the device is not detached, and therefore |
| 654 | * that the major number is still valid when dereferenced. |
| 655 | */ |
| 656 | dev_t |
| 657 | devsw_blk2chr(dev_t bdev) |
| 658 | { |
| 659 | devmajor_t bmajor, cmajor; |
| 660 | int i; |
| 661 | dev_t rv; |
| 662 | |
| 663 | bmajor = major(bdev); |
| 664 | cmajor = NODEVMAJOR; |
| 665 | rv = NODEV; |
| 666 | |
| 667 | mutex_enter(&device_lock); |
| 668 | if (bmajor < 0 || bmajor >= max_bdevsws || bdevsw[bmajor] == NULL) { |
| 669 | mutex_exit(&device_lock); |
| 670 | return (NODEV); |
| 671 | } |
| 672 | for (i = 0 ; i < max_devsw_convs ; i++) { |
| 673 | if (devsw_conv[i].d_bmajor == bmajor) { |
| 674 | cmajor = devsw_conv[i].d_cmajor; |
| 675 | break; |
| 676 | } |
| 677 | } |
| 678 | if (cmajor >= 0 && cmajor < max_cdevsws && cdevsw[cmajor] != NULL) |
| 679 | rv = makedev(cmajor, minor(bdev)); |
| 680 | mutex_exit(&device_lock); |
| 681 | |
| 682 | return (rv); |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | * Device access methods. |
| 687 | */ |
| 688 | |
| 689 | #define DEV_LOCK(d) \ |
| 690 | if ((mpflag = (d->d_flag & D_MPSAFE)) == 0) { \ |
| 691 | KERNEL_LOCK(1, NULL); \ |
| 692 | } |
| 693 | |
| 694 | #define DEV_UNLOCK(d) \ |
| 695 | if (mpflag == 0) { \ |
| 696 | KERNEL_UNLOCK_ONE(NULL); \ |
| 697 | } |
| 698 | |
| 699 | int |
| 700 | bdev_open(dev_t dev, int flag, int devtype, lwp_t *l) |
| 701 | { |
| 702 | const struct bdevsw *d; |
| 703 | int rv, mpflag; |
| 704 | |
| 705 | /* |
| 706 | * For open we need to lock, in order to synchronize |
| 707 | * with attach/detach. |
| 708 | */ |
| 709 | mutex_enter(&device_lock); |
| 710 | d = bdevsw_lookup(dev); |
| 711 | mutex_exit(&device_lock); |
| 712 | if (d == NULL) |
| 713 | return ENXIO; |
| 714 | |
| 715 | DEV_LOCK(d); |
| 716 | rv = (*d->d_open)(dev, flag, devtype, l); |
| 717 | DEV_UNLOCK(d); |
| 718 | |
| 719 | return rv; |
| 720 | } |
| 721 | |
| 722 | int |
| 723 | bdev_close(dev_t dev, int flag, int devtype, lwp_t *l) |
| 724 | { |
| 725 | const struct bdevsw *d; |
| 726 | int rv, mpflag; |
| 727 | |
| 728 | if ((d = bdevsw_lookup(dev)) == NULL) |
| 729 | return ENXIO; |
| 730 | |
| 731 | DEV_LOCK(d); |
| 732 | rv = (*d->d_close)(dev, flag, devtype, l); |
| 733 | DEV_UNLOCK(d); |
| 734 | |
| 735 | return rv; |
| 736 | } |
| 737 | |
| 738 | SDT_PROVIDER_DECLARE(io); |
| 739 | SDT_PROBE_DEFINE1(io, kernel, , start, "struct buf *" /*bp*/); |
| 740 | |
| 741 | void |
| 742 | bdev_strategy(struct buf *bp) |
| 743 | { |
| 744 | const struct bdevsw *d; |
| 745 | int mpflag; |
| 746 | |
| 747 | SDT_PROBE1(io, kernel, , start, bp); |
| 748 | |
| 749 | if ((d = bdevsw_lookup(bp->b_dev)) == NULL) { |
| 750 | bp->b_error = ENXIO; |
| 751 | bp->b_resid = bp->b_bcount; |
| 752 | biodone_vfs(bp); /* biodone() iff vfs present */ |
| 753 | return; |
| 754 | } |
| 755 | |
| 756 | DEV_LOCK(d); |
| 757 | (*d->d_strategy)(bp); |
| 758 | DEV_UNLOCK(d); |
| 759 | } |
| 760 | |
| 761 | int |
| 762 | bdev_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) |
| 763 | { |
| 764 | const struct bdevsw *d; |
| 765 | int rv, mpflag; |
| 766 | |
| 767 | if ((d = bdevsw_lookup(dev)) == NULL) |
| 768 | return ENXIO; |
| 769 | |
| 770 | DEV_LOCK(d); |
| 771 | rv = (*d->d_ioctl)(dev, cmd, data, flag, l); |
| 772 | DEV_UNLOCK(d); |
| 773 | |
| 774 | return rv; |
| 775 | } |
| 776 | |
| 777 | int |
| 778 | bdev_dump(dev_t dev, daddr_t addr, void *data, size_t sz) |
| 779 | { |
| 780 | const struct bdevsw *d; |
| 781 | int rv; |
| 782 | |
| 783 | /* |
| 784 | * Dump can be called without the device open. Since it can |
| 785 | * currently only be called with the system paused (and in a |
| 786 | * potentially unstable state), we don't perform any locking. |
| 787 | */ |
| 788 | if ((d = bdevsw_lookup(dev)) == NULL) |
| 789 | return ENXIO; |
| 790 | |
| 791 | /* DEV_LOCK(d); */ |
| 792 | rv = (*d->d_dump)(dev, addr, data, sz); |
| 793 | /* DEV_UNLOCK(d); */ |
| 794 | |
| 795 | return rv; |
| 796 | } |
| 797 | |
| 798 | int |
| 799 | bdev_type(dev_t dev) |
| 800 | { |
| 801 | const struct bdevsw *d; |
| 802 | |
| 803 | if ((d = bdevsw_lookup(dev)) == NULL) |
| 804 | return D_OTHER; |
| 805 | return d->d_flag & D_TYPEMASK; |
| 806 | } |
| 807 | |
| 808 | int |
| 809 | bdev_size(dev_t dev) |
| 810 | { |
| 811 | const struct bdevsw *d; |
| 812 | int rv, mpflag = 0; |
| 813 | |
| 814 | if ((d = bdevsw_lookup(dev)) == NULL || |
| 815 | d->d_psize == NULL) |
| 816 | return -1; |
| 817 | |
| 818 | /* |
| 819 | * Don't to try lock the device if we're dumping. |
| 820 | * XXX: is there a better way to test this? |
| 821 | */ |
| 822 | if ((boothowto & RB_DUMP) == 0) |
| 823 | DEV_LOCK(d); |
| 824 | rv = (*d->d_psize)(dev); |
| 825 | if ((boothowto & RB_DUMP) == 0) |
| 826 | DEV_UNLOCK(d); |
| 827 | |
| 828 | return rv; |
| 829 | } |
| 830 | |
| 831 | int |
| 832 | bdev_discard(dev_t dev, off_t pos, off_t len) |
| 833 | { |
| 834 | const struct bdevsw *d; |
| 835 | int rv, mpflag; |
| 836 | |
| 837 | if ((d = bdevsw_lookup(dev)) == NULL) |
| 838 | return ENXIO; |
| 839 | |
| 840 | DEV_LOCK(d); |
| 841 | rv = (*d->d_discard)(dev, pos, len); |
| 842 | DEV_UNLOCK(d); |
| 843 | |
| 844 | return rv; |
| 845 | } |
| 846 | |
| 847 | int |
| 848 | cdev_open(dev_t dev, int flag, int devtype, lwp_t *l) |
| 849 | { |
| 850 | const struct cdevsw *d; |
| 851 | int rv, mpflag; |
| 852 | |
| 853 | /* |
| 854 | * For open we need to lock, in order to synchronize |
| 855 | * with attach/detach. |
| 856 | */ |
| 857 | mutex_enter(&device_lock); |
| 858 | d = cdevsw_lookup(dev); |
| 859 | mutex_exit(&device_lock); |
| 860 | if (d == NULL) |
| 861 | return ENXIO; |
| 862 | |
| 863 | DEV_LOCK(d); |
| 864 | rv = (*d->d_open)(dev, flag, devtype, l); |
| 865 | DEV_UNLOCK(d); |
| 866 | |
| 867 | return rv; |
| 868 | } |
| 869 | |
| 870 | int |
| 871 | cdev_close(dev_t dev, int flag, int devtype, lwp_t *l) |
| 872 | { |
| 873 | const struct cdevsw *d; |
| 874 | int rv, mpflag; |
| 875 | |
| 876 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 877 | return ENXIO; |
| 878 | |
| 879 | DEV_LOCK(d); |
| 880 | rv = (*d->d_close)(dev, flag, devtype, l); |
| 881 | DEV_UNLOCK(d); |
| 882 | |
| 883 | return rv; |
| 884 | } |
| 885 | |
| 886 | int |
| 887 | cdev_read(dev_t dev, struct uio *uio, int flag) |
| 888 | { |
| 889 | const struct cdevsw *d; |
| 890 | int rv, mpflag; |
| 891 | |
| 892 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 893 | return ENXIO; |
| 894 | |
| 895 | DEV_LOCK(d); |
| 896 | rv = (*d->d_read)(dev, uio, flag); |
| 897 | DEV_UNLOCK(d); |
| 898 | |
| 899 | return rv; |
| 900 | } |
| 901 | |
| 902 | int |
| 903 | cdev_write(dev_t dev, struct uio *uio, int flag) |
| 904 | { |
| 905 | const struct cdevsw *d; |
| 906 | int rv, mpflag; |
| 907 | |
| 908 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 909 | return ENXIO; |
| 910 | |
| 911 | DEV_LOCK(d); |
| 912 | rv = (*d->d_write)(dev, uio, flag); |
| 913 | DEV_UNLOCK(d); |
| 914 | |
| 915 | return rv; |
| 916 | } |
| 917 | |
| 918 | int |
| 919 | cdev_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) |
| 920 | { |
| 921 | const struct cdevsw *d; |
| 922 | int rv, mpflag; |
| 923 | |
| 924 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 925 | return ENXIO; |
| 926 | |
| 927 | DEV_LOCK(d); |
| 928 | rv = (*d->d_ioctl)(dev, cmd, data, flag, l); |
| 929 | DEV_UNLOCK(d); |
| 930 | |
| 931 | return rv; |
| 932 | } |
| 933 | |
| 934 | void |
| 935 | cdev_stop(struct tty *tp, int flag) |
| 936 | { |
| 937 | const struct cdevsw *d; |
| 938 | int mpflag; |
| 939 | |
| 940 | if ((d = cdevsw_lookup(tp->t_dev)) == NULL) |
| 941 | return; |
| 942 | |
| 943 | DEV_LOCK(d); |
| 944 | (*d->d_stop)(tp, flag); |
| 945 | DEV_UNLOCK(d); |
| 946 | } |
| 947 | |
| 948 | struct tty * |
| 949 | cdev_tty(dev_t dev) |
| 950 | { |
| 951 | const struct cdevsw *d; |
| 952 | |
| 953 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 954 | return NULL; |
| 955 | |
| 956 | /* XXX Check if necessary. */ |
| 957 | if (d->d_tty == NULL) |
| 958 | return NULL; |
| 959 | |
| 960 | return (*d->d_tty)(dev); |
| 961 | } |
| 962 | |
| 963 | int |
| 964 | cdev_poll(dev_t dev, int flag, lwp_t *l) |
| 965 | { |
| 966 | const struct cdevsw *d; |
| 967 | int rv, mpflag; |
| 968 | |
| 969 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 970 | return POLLERR; |
| 971 | |
| 972 | DEV_LOCK(d); |
| 973 | rv = (*d->d_poll)(dev, flag, l); |
| 974 | DEV_UNLOCK(d); |
| 975 | |
| 976 | return rv; |
| 977 | } |
| 978 | |
| 979 | paddr_t |
| 980 | cdev_mmap(dev_t dev, off_t off, int flag) |
| 981 | { |
| 982 | const struct cdevsw *d; |
| 983 | paddr_t rv; |
| 984 | int mpflag; |
| 985 | |
| 986 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 987 | return (paddr_t)-1LL; |
| 988 | |
| 989 | DEV_LOCK(d); |
| 990 | rv = (*d->d_mmap)(dev, off, flag); |
| 991 | DEV_UNLOCK(d); |
| 992 | |
| 993 | return rv; |
| 994 | } |
| 995 | |
| 996 | int |
| 997 | cdev_kqfilter(dev_t dev, struct knote *kn) |
| 998 | { |
| 999 | const struct cdevsw *d; |
| 1000 | int rv, mpflag; |
| 1001 | |
| 1002 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 1003 | return ENXIO; |
| 1004 | |
| 1005 | DEV_LOCK(d); |
| 1006 | rv = (*d->d_kqfilter)(dev, kn); |
| 1007 | DEV_UNLOCK(d); |
| 1008 | |
| 1009 | return rv; |
| 1010 | } |
| 1011 | |
| 1012 | int |
| 1013 | cdev_discard(dev_t dev, off_t pos, off_t len) |
| 1014 | { |
| 1015 | const struct cdevsw *d; |
| 1016 | int rv, mpflag; |
| 1017 | |
| 1018 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 1019 | return ENXIO; |
| 1020 | |
| 1021 | DEV_LOCK(d); |
| 1022 | rv = (*d->d_discard)(dev, pos, len); |
| 1023 | DEV_UNLOCK(d); |
| 1024 | |
| 1025 | return rv; |
| 1026 | } |
| 1027 | |
| 1028 | int |
| 1029 | cdev_type(dev_t dev) |
| 1030 | { |
| 1031 | const struct cdevsw *d; |
| 1032 | |
| 1033 | if ((d = cdevsw_lookup(dev)) == NULL) |
| 1034 | return D_OTHER; |
| 1035 | return d->d_flag & D_TYPEMASK; |
| 1036 | } |
| 1037 | |