1 /* $NetBSD: subr_devsw.c,v 1.7 2003/07/14 14:59:02 lukem Exp $ */ 2 /*- 3 * Copyright (c) 2001,2002 The NetBSD Foundation, Inc. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to The NetBSD Foundation 7 * by MAEKAWA Masahide <gehenna@NetBSD.org>. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the NetBSD 20 * Foundation, Inc. and its contributors. 21 * 4. Neither the name of The NetBSD Foundation nor the names of its 22 * contributors may be used to endorse or promote products derived 23 * from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.7 2003/07/14 14:59:02 lukem Exp $"); 40 41 /* 42 * New device switch framework is developing. 43 * So debug options are always turned on. 44 */ 45 #ifndef DEVSW_DEBUG 46 #define DEVSW_DEBUG 47 #endif /* DEVSW_DEBUG */ 48 49 #include <sys/param.h> 50 #include <sys/conf.h> 51 #include <sys/malloc.h> 52 #include <sys/systm.h> 53 54 #ifdef DEVSW_DEBUG 55 #define DPRINTF(x) printf x 56 #else /* DEVSW_DEBUG */ 57 #define DPRINTF(x) 58 #endif /* DEVSW_DEBUG */ 59 60 #define MAXDEVSW 4096 /* the maximum of major device number */ 61 #define BDEVSW_SIZE (sizeof(struct bdevsw *)) 62 #define CDEVSW_SIZE (sizeof(struct cdevsw *)) 63 #define DEVSWCONV_SIZE (sizeof(struct devsw_conv)) 64 65 extern const struct bdevsw **bdevsw, *bdevsw0[]; 66 extern const struct cdevsw **cdevsw, *cdevsw0[]; 67 extern struct devsw_conv *devsw_conv, devsw_conv0[]; 68 extern const int sys_bdevsws, sys_cdevsws; 69 extern int max_bdevsws, max_cdevsws, max_devsw_convs; 70 71 static int bdevsw_attach(const char *, const struct bdevsw *, int *); 72 static int cdevsw_attach(const char *, const struct cdevsw *, int *); 73 74 int 75 devsw_attach(const char *devname, const struct bdevsw *bdev, int *bmajor, 76 const struct cdevsw *cdev, int *cmajor) 77 { 78 struct devsw_conv *conv; 79 char *name; 80 int error, i; 81 82 if (devname == NULL || cdev == NULL) 83 return (EINVAL); 84 85 for (i = 0 ; i < max_devsw_convs ; i++) { 86 conv = &devsw_conv[i]; 87 if (conv->d_name == NULL || strcmp(devname, conv->d_name) != 0) 88 continue; 89 90 if (*bmajor < 0) 91 *bmajor = conv->d_bmajor; 92 if (*cmajor < 0) 93 *cmajor = conv->d_cmajor; 94 95 if (*bmajor != conv->d_bmajor || *cmajor != conv->d_cmajor) 96 return (EINVAL); 97 if ((*bmajor >= 0 && bdev == NULL) || *cmajor < 0) 98 return (EINVAL); 99 100 if ((*bmajor >= 0 && bdevsw[*bmajor] != NULL) || 101 cdevsw[*cmajor] != NULL) 102 return (EEXIST); 103 104 if (bdev != NULL) 105 bdevsw[*bmajor] = bdev; 106 cdevsw[*cmajor] = cdev; 107 108 return (0); 109 } 110 111 error = bdevsw_attach(devname, bdev, bmajor); 112 if (error != 0) 113 return (error); 114 error = cdevsw_attach(devname, cdev, cmajor); 115 if (error != 0) { 116 devsw_detach(bdev, NULL); 117 return (error); 118 } 119 120 for (i = 0 ; i < max_devsw_convs ; i++) { 121 if (devsw_conv[i].d_name == NULL) 122 break; 123 } 124 if (i == max_devsw_convs) { 125 struct devsw_conv *newptr; 126 int old, new; 127 128 old = max_devsw_convs; 129 new = old + 1; 130 131 newptr = malloc(new * DEVSWCONV_SIZE, M_DEVBUF, M_NOWAIT); 132 if (newptr == NULL) { 133 devsw_detach(bdev, cdev); 134 return (ENOMEM); 135 } 136 newptr[old].d_name = NULL; 137 newptr[old].d_bmajor = -1; 138 newptr[old].d_cmajor = -1; 139 memcpy(newptr, devsw_conv, old * DEVSWCONV_SIZE); 140 if (devsw_conv != devsw_conv0) 141 free(devsw_conv, M_DEVBUF); 142 devsw_conv = newptr; 143 max_devsw_convs = new; 144 } 145 146 i = strlen(devname) + 1; 147 name = malloc(i, M_DEVBUF, M_NOWAIT); 148 if (name == NULL) { 149 devsw_detach(bdev, cdev); 150 return (ENOMEM); 151 } 152 strlcpy(name, devname, i); 153 154 devsw_conv[i].d_name = name; 155 devsw_conv[i].d_bmajor = *bmajor; 156 devsw_conv[i].d_cmajor = *cmajor; 157 158 return (0); 159 } 160 161 static int 162 bdevsw_attach(const char *devname, const struct bdevsw *devsw, int *devmajor) 163 { 164 int bmajor, i; 165 166 if (devsw == NULL) 167 return (0); 168 169 if (*devmajor < 0) { 170 for (bmajor = sys_bdevsws ; bmajor < max_bdevsws ; bmajor++) { 171 if (bdevsw[bmajor] != NULL) 172 continue; 173 for (i = 0 ; i < max_devsw_convs ; i++) { 174 if (devsw_conv[i].d_bmajor == bmajor) 175 break; 176 } 177 if (i != max_devsw_convs) 178 continue; 179 break; 180 } 181 *devmajor = bmajor; 182 } 183 if (*devmajor >= MAXDEVSW) { 184 #ifdef DEVSW_DEBUG 185 panic("bdevsw_attach: block majors exhausted"); 186 #endif /* DEVSW_DEBUG */ 187 return (ENOMEM); 188 } 189 190 if (*devmajor >= max_bdevsws) { 191 const struct bdevsw **newptr; 192 int old, new; 193 194 old = max_bdevsws; 195 new = *devmajor + 1; 196 197 newptr = malloc(new * BDEVSW_SIZE, M_DEVBUF, M_NOWAIT); 198 if (newptr == NULL) 199 return (ENOMEM); 200 memset(newptr + old, 0, (new - old) * BDEVSW_SIZE); 201 if (old != 0) { 202 memcpy(newptr, bdevsw, old * BDEVSW_SIZE); 203 if (bdevsw != bdevsw0) 204 free(bdevsw, M_DEVBUF); 205 } 206 bdevsw = newptr; 207 max_bdevsws = new; 208 } 209 210 if (bdevsw[*devmajor] != NULL) 211 return (EEXIST); 212 213 bdevsw[*devmajor] = devsw; 214 215 return (0); 216 } 217 218 static int 219 cdevsw_attach(const char *devname, const struct cdevsw *devsw, int *devmajor) 220 { 221 int cmajor, i; 222 223 if (*devmajor < 0) { 224 for (cmajor = sys_cdevsws ; cmajor < max_cdevsws ; cmajor++) { 225 if (cdevsw[cmajor] != NULL) 226 continue; 227 for (i = 0 ; i < max_devsw_convs ; i++) { 228 if (devsw_conv[i].d_cmajor == cmajor) 229 break; 230 } 231 if (i != max_devsw_convs) 232 continue; 233 break; 234 } 235 *devmajor = cmajor; 236 } 237 if (*devmajor >= MAXDEVSW) { 238 #ifdef DEVSW_DEBUG 239 panic("cdevsw_attach: character majors exhausted"); 240 #endif /* DEVSW_DEBUG */ 241 return (ENOMEM); 242 } 243 244 if (*devmajor >= max_cdevsws) { 245 const struct cdevsw **newptr; 246 int old, new; 247 248 old = max_cdevsws; 249 new = *devmajor + 1; 250 251 newptr = malloc(new * CDEVSW_SIZE, M_DEVBUF, M_NOWAIT); 252 if (newptr == NULL) 253 return (ENOMEM); 254 memset(newptr + old, 0, (new - old) * CDEVSW_SIZE); 255 if (old != 0) { 256 memcpy(newptr, cdevsw, old * CDEVSW_SIZE); 257 if (cdevsw != cdevsw0) 258 free(cdevsw, M_DEVBUF); 259 } 260 cdevsw = newptr; 261 max_cdevsws = new; 262 } 263 264 if (cdevsw[*devmajor] != NULL) 265 return (EEXIST); 266 267 cdevsw[*devmajor] = devsw; 268 269 return (0); 270 } 271 272 void 273 devsw_detach(const struct bdevsw *bdev, const struct cdevsw *cdev) 274 { 275 int i; 276 277 if (bdev != NULL) { 278 for (i = 0 ; i < max_bdevsws ; i++) { 279 if (bdevsw[i] != bdev) 280 continue; 281 bdevsw[i] = NULL; 282 break; 283 } 284 } 285 if (cdev != NULL) { 286 for (i = 0 ; i < max_cdevsws ; i++) { 287 if (cdevsw[i] != cdev) 288 continue; 289 cdevsw[i] = NULL; 290 break; 291 } 292 } 293 } 294 295 const struct bdevsw * 296 bdevsw_lookup(dev_t dev) 297 { 298 int bmajor; 299 300 if (dev == NODEV) 301 return (NULL); 302 bmajor = major(dev); 303 if (bmajor < 0 || bmajor >= max_bdevsws) 304 return (NULL); 305 306 return (bdevsw[bmajor]); 307 } 308 309 const struct cdevsw * 310 cdevsw_lookup(dev_t dev) 311 { 312 int cmajor; 313 314 if (dev == NODEV) 315 return (NULL); 316 cmajor = major(dev); 317 if (cmajor < 0 || cmajor >= max_cdevsws) 318 return (NULL); 319 320 return (cdevsw[cmajor]); 321 } 322 323 int 324 bdevsw_lookup_major(const struct bdevsw *bdev) 325 { 326 int bmajor; 327 328 for (bmajor = 0 ; bmajor < max_bdevsws ; bmajor++) { 329 if (bdevsw[bmajor] == bdev) 330 return (bmajor); 331 } 332 333 return (-1); 334 } 335 336 int 337 cdevsw_lookup_major(const struct cdevsw *cdev) 338 { 339 int cmajor; 340 341 for (cmajor = 0 ; cmajor < max_cdevsws ; cmajor++) { 342 if (cdevsw[cmajor] == cdev) 343 return (cmajor); 344 } 345 346 return (-1); 347 } 348 349 /* 350 * Convert from block major number to name. 351 */ 352 const char * 353 devsw_blk2name(int bmajor) 354 { 355 int cmajor, i; 356 357 if (bmajor < 0 || bmajor >= max_bdevsws || bdevsw[bmajor] == NULL) 358 return (NULL); 359 360 for (i = 0 ; i < max_devsw_convs ; i++) { 361 if (devsw_conv[i].d_bmajor != bmajor) 362 continue; 363 cmajor = devsw_conv[i].d_cmajor; 364 if (cmajor < 0 || cmajor >= max_cdevsws || 365 cdevsw[cmajor] == NULL) 366 return (NULL); 367 return (devsw_conv[i].d_name); 368 } 369 370 return (NULL); 371 } 372 373 /* 374 * Convert from device name to block major number. 375 */ 376 int 377 devsw_name2blk(const char *name, char *devname, size_t devnamelen) 378 { 379 struct devsw_conv *conv; 380 int bmajor, i; 381 382 if (name == NULL) 383 return (-1); 384 385 for (i = 0 ; i < max_devsw_convs ; i++) { 386 size_t len; 387 388 conv = &devsw_conv[i]; 389 if (conv->d_name == NULL) 390 continue; 391 len = strlen(conv->d_name); 392 if (strncmp(conv->d_name, name, len) != 0) 393 continue; 394 if (*(name +len) && !isdigit(*(name + len))) 395 continue; 396 bmajor = conv->d_bmajor; 397 if (bmajor < 0 || bmajor >= max_bdevsws || 398 bdevsw[bmajor] == NULL) 399 break; 400 if (devname != NULL) { 401 #ifdef DEVSW_DEBUG 402 if (strlen(conv->d_name) >= devnamelen) 403 printf("devsw_name2blk: too short buffer"); 404 #endif /* DEVSW_DEBUG */ 405 strncpy(devname, conv->d_name, devnamelen); 406 devname[devnamelen - 1] = '\0'; 407 } 408 return (bmajor); 409 } 410 411 return (-1); 412 } 413 414 /* 415 * Convert from character dev_t to block dev_t. 416 */ 417 dev_t 418 devsw_chr2blk(dev_t cdev) 419 { 420 int bmajor, cmajor, i; 421 422 if (cdevsw_lookup(cdev) == NULL) 423 return (NODEV); 424 425 cmajor = major(cdev); 426 427 for (i = 0 ; i < max_devsw_convs ; i++) { 428 if (devsw_conv[i].d_cmajor != cmajor) 429 continue; 430 bmajor = devsw_conv[i].d_bmajor; 431 if (bmajor < 0 || bmajor >= max_bdevsws || 432 bdevsw[bmajor] == NULL) 433 return (NODEV); 434 return (makedev(bmajor, minor(cdev))); 435 } 436 437 return (NODEV); 438 } 439 440 /* 441 * Convert from block dev_t to character dev_t. 442 */ 443 dev_t 444 devsw_blk2chr(dev_t bdev) 445 { 446 int bmajor, cmajor, i; 447 448 if (bdevsw_lookup(bdev) == NULL) 449 return (NODEV); 450 451 bmajor = major(bdev); 452 453 for (i = 0 ; i < max_devsw_convs ; i++) { 454 if (devsw_conv[i].d_bmajor != bmajor) 455 continue; 456 cmajor = devsw_conv[i].d_cmajor; 457 if (cmajor < 0 || cmajor >= max_cdevsws || 458 cdevsw[cmajor] == NULL) 459 return (NODEV); 460 return (makedev(cmajor, minor(bdev))); 461 } 462 463 return (NODEV); 464 } 465