1 /* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * 9 * $FreeBSD: src/sys/dev/md/md.c,v 1.8.2.2 2002/08/19 17:43:34 jdp Exp $ 10 * 11 */ 12 13 #include "opt_md.h" /* We have adopted some tasks from MFS */ 14 15 #include <sys/param.h> 16 #include <sys/systm.h> 17 #include <sys/buf.h> 18 #include <sys/conf.h> 19 #include <sys/devicestat.h> 20 #include <sys/disk.h> 21 #include <sys/kernel.h> 22 #include <sys/malloc.h> 23 #include <sys/sysctl.h> 24 #include <sys/linker.h> 25 #include <sys/proc.h> 26 #include <sys/buf2.h> 27 #include <sys/thread2.h> 28 #include <sys/queue.h> 29 #include <sys/udev.h> 30 31 #ifndef MD_NSECT 32 #define MD_NSECT (10000 * 2) 33 #endif 34 35 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk"); 36 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors"); 37 38 static int md_debug; 39 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, ""); 40 41 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE) 42 /* Image gets put here: */ 43 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here"; 44 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here"; 45 #endif 46 47 static int mdrootready; 48 49 static d_strategy_t mdstrategy; 50 static d_strategy_t mdstrategy_preload; 51 static d_strategy_t mdstrategy_malloc; 52 static d_open_t mdopen; 53 static d_close_t mdclose; 54 static d_ioctl_t mdioctl; 55 56 static struct dev_ops md_ops = { 57 { "md", 0, D_DISK | D_CANFREE | D_MEMDISK | D_TRACKCLOSE}, 58 .d_open = mdopen, 59 .d_close = mdclose, 60 .d_read = physread, 61 .d_write = physwrite, 62 .d_ioctl = mdioctl, 63 .d_strategy = mdstrategy, 64 }; 65 66 struct md_s { 67 int unit; 68 struct devstat stats; 69 struct bio_queue_head bio_queue; 70 struct disk disk; 71 cdev_t dev; 72 int busy; 73 enum { /* Memory disk type */ 74 MD_MALLOC, 75 MD_PRELOAD 76 } type; 77 unsigned nsect; 78 79 /* MD_MALLOC related fields */ 80 unsigned nsecp; 81 u_char **secp; 82 83 /* MD_PRELOAD related fields */ 84 u_char *pl_ptr; 85 unsigned pl_len; 86 TAILQ_ENTRY(md_s) link; 87 }; 88 TAILQ_HEAD(mdshead, md_s) mdlist = TAILQ_HEAD_INITIALIZER(mdlist); 89 90 static int mdunits; 91 static int refcnt; 92 93 static struct md_s *mdcreate(unsigned); 94 static void mdcreate_malloc(void); 95 static int mdinit(module_t, int, void *); 96 static void md_drvinit(void *); 97 static int md_drvcleanup(void); 98 99 static int 100 mdinit(module_t mod, int cmd, void *arg) 101 { 102 int ret = 0; 103 104 switch(cmd) { 105 case MOD_LOAD: 106 TAILQ_INIT(&mdlist); 107 md_drvinit(NULL); 108 break; 109 case MOD_UNLOAD: 110 ret = md_drvcleanup(); 111 break; 112 default: 113 ret = EINVAL; 114 break; 115 } 116 117 return (ret); 118 } 119 120 static int 121 mdopen(struct dev_open_args *ap) 122 { 123 cdev_t dev = ap->a_head.a_dev; 124 struct md_s *sc; 125 126 if (md_debug) 127 kprintf("mdopen(%s %x %x)\n", 128 devtoname(dev), ap->a_oflags, ap->a_devtype); 129 130 sc = dev->si_drv1; 131 if (sc->unit + 1 == mdunits) 132 mdcreate_malloc(); 133 134 atomic_add_int(&refcnt, 1); 135 return (0); 136 } 137 138 static int 139 mdclose(struct dev_close_args *ap) 140 { 141 cdev_t dev = ap->a_head.a_dev; 142 struct md_s *sc; 143 144 if (md_debug) 145 kprintf("mdclose(%s %x %x)\n", 146 devtoname(dev), ap->a_fflag, ap->a_devtype); 147 sc = dev->si_drv1; 148 atomic_add_int(&refcnt, -1); 149 150 return (0); 151 } 152 153 static int 154 mdioctl(struct dev_ioctl_args *ap) 155 { 156 cdev_t dev = ap->a_head.a_dev; 157 158 if (md_debug) 159 kprintf("mdioctl(%s %lx %p %x)\n", 160 devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag); 161 162 return (ENOIOCTL); 163 } 164 165 static int 166 mdstrategy(struct dev_strategy_args *ap) 167 { 168 cdev_t dev = ap->a_head.a_dev; 169 struct bio *bio = ap->a_bio; 170 struct buf *bp = bio->bio_buf; 171 struct md_s *sc; 172 173 if (md_debug > 1) { 174 kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n", 175 bp, devtoname(dev), bp->b_flags, 176 (long long)bio->bio_offset, 177 bp->b_bcount, bp->b_data); 178 } 179 bio->bio_driver_info = dev; 180 sc = dev->si_drv1; 181 if (sc->type == MD_MALLOC) { 182 mdstrategy_malloc(ap); 183 } else { 184 mdstrategy_preload(ap); 185 } 186 return(0); 187 } 188 189 190 static int 191 mdstrategy_malloc(struct dev_strategy_args *ap) 192 { 193 cdev_t dev = ap->a_head.a_dev; 194 struct bio *bio = ap->a_bio; 195 struct buf *bp = bio->bio_buf; 196 unsigned secno, nsec, secval, uc; 197 u_char *secp, **secpp, *dst; 198 struct md_s *sc; 199 int i; 200 201 if (md_debug > 1) 202 kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n", 203 bp, devtoname(dev), bp->b_flags, 204 (long long)bio->bio_offset, 205 bp->b_bcount, bp->b_data); 206 207 sc = dev->si_drv1; 208 209 crit_enter(); 210 211 bioqdisksort(&sc->bio_queue, bio); 212 213 if (sc->busy) { 214 crit_exit(); 215 return(0); 216 } 217 218 sc->busy++; 219 220 while (1) { 221 bio = bioq_first(&sc->bio_queue); 222 if (bio == NULL) { 223 crit_exit(); 224 break; 225 } 226 crit_exit(); 227 bioq_remove(&sc->bio_queue, bio); 228 bp = bio->bio_buf; 229 230 devstat_start_transaction(&sc->stats); 231 232 switch (bp->b_cmd) { 233 case BUF_CMD_FREEBLKS: 234 case BUF_CMD_READ: 235 case BUF_CMD_WRITE: 236 break; 237 default: 238 panic("md: bad b_cmd %d", bp->b_cmd); 239 } 240 241 nsec = bp->b_bcount >> DEV_BSHIFT; 242 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT); 243 dst = bp->b_data; 244 while (nsec--) { 245 if (secno < sc->nsecp) { 246 secpp = &sc->secp[secno]; 247 if ((u_int)(uintptr_t)*secpp > 255) { 248 secp = *secpp; 249 secval = 0; 250 } else { 251 secp = 0; 252 secval = (u_int)(uintptr_t)*secpp; 253 } 254 } else { 255 secpp = 0; 256 secp = 0; 257 secval = 0; 258 } 259 if (md_debug > 2) 260 kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval); 261 262 switch (bp->b_cmd) { 263 case BUF_CMD_FREEBLKS: 264 if (secpp) { 265 if (secp) 266 FREE(secp, M_MDSECT); 267 *secpp = 0; 268 } 269 break; 270 case BUF_CMD_READ: 271 if (secp) { 272 bcopy(secp, dst, DEV_BSIZE); 273 } else if (secval) { 274 for (i = 0; i < DEV_BSIZE; i++) 275 dst[i] = secval; 276 } else { 277 bzero(dst, DEV_BSIZE); 278 } 279 break; 280 case BUF_CMD_WRITE: 281 uc = dst[0]; 282 for (i = 1; i < DEV_BSIZE; i++) 283 if (dst[i] != uc) 284 break; 285 if (i == DEV_BSIZE && !uc) { 286 if (secp) 287 FREE(secp, M_MDSECT); 288 if (secpp) 289 *secpp = (u_char *)(uintptr_t)uc; 290 } else { 291 if (!secpp) { 292 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 293 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 294 FREE(sc->secp, M_MD); 295 sc->secp = secpp; 296 sc->nsecp = secno + nsec + 1; 297 secpp = &sc->secp[secno]; 298 } 299 if (i == DEV_BSIZE) { 300 if (secp) 301 FREE(secp, M_MDSECT); 302 *secpp = (u_char *)(uintptr_t)uc; 303 } else { 304 if (!secp) 305 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 306 bcopy(dst, secp, DEV_BSIZE); 307 308 *secpp = secp; 309 } 310 } 311 break; 312 default: 313 panic("md: bad b_cmd %d", bp->b_cmd); 314 315 } 316 secno++; 317 dst += DEV_BSIZE; 318 } 319 bp->b_resid = 0; 320 devstat_end_transaction_buf(&sc->stats, bp); 321 biodone(bio); 322 crit_enter(); 323 } 324 sc->busy = 0; 325 return(0); 326 } 327 328 329 static int 330 mdstrategy_preload(struct dev_strategy_args *ap) 331 { 332 cdev_t dev = ap->a_head.a_dev; 333 struct bio *bio = ap->a_bio; 334 struct buf *bp = bio->bio_buf; 335 struct md_s *sc; 336 337 if (md_debug > 1) 338 kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n", 339 bp, devtoname(dev), bp->b_flags, 340 (long long)bio->bio_offset, 341 bp->b_bcount, bp->b_data); 342 343 sc = dev->si_drv1; 344 345 crit_enter(); 346 347 bioqdisksort(&sc->bio_queue, bio); 348 349 if (sc->busy) { 350 crit_exit(); 351 return(0); 352 } 353 354 sc->busy++; 355 356 while (1) { 357 bio = bioq_first(&sc->bio_queue); 358 if (bio) 359 bioq_remove(&sc->bio_queue, bio); 360 crit_exit(); 361 if (bio == NULL) 362 break; 363 364 devstat_start_transaction(&sc->stats); 365 366 switch (bp->b_cmd) { 367 case BUF_CMD_FREEBLKS: 368 break; 369 case BUF_CMD_READ: 370 bcopy(sc->pl_ptr + bio->bio_offset, 371 bp->b_data, bp->b_bcount); 372 break; 373 case BUF_CMD_WRITE: 374 bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset, 375 bp->b_bcount); 376 break; 377 default: 378 panic("md: bad cmd %d\n", bp->b_cmd); 379 } 380 bp->b_resid = 0; 381 devstat_end_transaction_buf(&sc->stats, bp); 382 biodone(bio); 383 crit_enter(); 384 } 385 sc->busy = 0; 386 return(0); 387 } 388 389 static struct md_s * 390 mdcreate(unsigned length) 391 { 392 struct md_s *sc; 393 struct disk_info info; 394 395 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK | M_ZERO); 396 sc->unit = mdunits++; 397 bioq_init(&sc->bio_queue); 398 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 399 DEVSTAT_NO_ORDERED_TAGS, 400 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 401 DEVSTAT_PRIORITY_OTHER); 402 sc->dev = disk_create(sc->unit, &sc->disk, &md_ops); 403 sc->dev->si_drv1 = sc; 404 sc->dev->si_iosize_max = DFLTPHYS; 405 disk_setdisktype(&sc->disk, "memory"); 406 407 bzero(&info, sizeof(info)); 408 info.d_media_blksize = DEV_BSIZE; /* mandatory */ 409 info.d_media_blocks = length / DEV_BSIZE; 410 411 info.d_secpertrack = 1024; /* optional */ 412 info.d_nheads = 1; 413 info.d_secpercyl = info.d_secpertrack * info.d_nheads; 414 info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl); 415 disk_setdiskinfo(&sc->disk, &info); 416 TAILQ_INSERT_HEAD(&mdlist, sc, link); 417 418 return (sc); 419 } 420 421 422 static void 423 mdcreate_preload(u_char *image, unsigned length) 424 { 425 struct md_s *sc; 426 427 sc = mdcreate(length); 428 sc->type = MD_PRELOAD; 429 sc->nsect = length / DEV_BSIZE; 430 sc->pl_ptr = image; 431 sc->pl_len = length; 432 433 if (sc->unit == 0) 434 mdrootready = 1; 435 } 436 437 static void 438 mdcreate_malloc(void) 439 { 440 struct md_s *sc; 441 442 sc = mdcreate(MD_NSECT*DEV_BSIZE); 443 sc->type = MD_MALLOC; 444 445 sc->nsect = MD_NSECT; /* for now */ 446 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 447 sc->nsecp = 1; 448 kprintf("md%d: Malloc disk\n", sc->unit); 449 } 450 451 static int 452 md_drvcleanup(void) 453 { 454 455 int secno; 456 struct md_s *sc, *sc_temp; 457 458 if (atomic_fetchadd_int(&refcnt, 0) != 0) 459 return EBUSY; 460 461 /* 462 * Go through all the md devices, freeing up all the 463 * memory allocated for sectors, and the md_s struct 464 * itself. 465 */ 466 TAILQ_FOREACH_MUTABLE(sc, &mdlist, link, sc_temp) { 467 for (secno = 0; secno < sc->nsecp; secno++) { 468 if ((u_int)(uintptr_t)sc->secp[secno] > 255) 469 FREE(sc->secp[secno], M_MDSECT); 470 } 471 472 if (sc->dev != NULL) 473 disk_destroy(&sc->disk); 474 475 devstat_remove_entry(&sc->stats); 476 TAILQ_REMOVE(&mdlist, sc, link); 477 478 FREE(sc->secp, M_MD); 479 FREE(sc, M_MD); 480 } 481 482 return 0; 483 484 } 485 486 static void 487 md_drvinit(void *unused) 488 { 489 490 caddr_t mod; 491 caddr_t c; 492 u_char *ptr, *name, *type; 493 unsigned len; 494 495 #ifdef MD_ROOT_SIZE 496 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 497 #endif 498 mod = NULL; 499 while ((mod = preload_search_next_name(mod)) != NULL) { 500 name = (char *)preload_search_info(mod, MODINFO_NAME); 501 type = (char *)preload_search_info(mod, MODINFO_TYPE); 502 if (name == NULL) 503 continue; 504 if (type == NULL) 505 continue; 506 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 507 continue; 508 c = preload_search_info(mod, MODINFO_ADDR); 509 ptr = *(u_char **)c; 510 c = preload_search_info(mod, MODINFO_SIZE); 511 len = *(unsigned *)c; 512 kprintf("md%d: Preloaded image <%s> %d bytes at %p\n", 513 mdunits, name, len, ptr); 514 mdcreate_preload(ptr, len); 515 } 516 mdcreate_malloc(); 517 } 518 519 DEV_MODULE(md, mdinit, NULL); 520 521 #ifdef MD_ROOT 522 static void 523 md_takeroot(void *junk) 524 { 525 if (mdrootready) 526 rootdevnames[0] = "ufs:/dev/md0s0"; 527 } 528 529 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 530 #endif 531