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 * $DragonFly: src/sys/dev/disk/md/md.c,v 1.20 2008/09/07 08:09:39 swildner Exp $ 11 * 12 */ 13 14 #include "opt_md.h" /* We have adopted some tasks from MFS */ 15 16 #include <sys/param.h> 17 #include <sys/systm.h> 18 #include <sys/buf.h> 19 #include <sys/conf.h> 20 #include <sys/devicestat.h> 21 #include <sys/disk.h> 22 #include <sys/kernel.h> 23 #include <sys/malloc.h> 24 #include <sys/sysctl.h> 25 #include <sys/linker.h> 26 #include <sys/proc.h> 27 #include <sys/buf2.h> 28 #include <sys/thread2.h> 29 #include <sys/queue.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 #define CDEV_MAJOR 95 50 51 static d_strategy_t mdstrategy; 52 static d_strategy_t mdstrategy_preload; 53 static d_strategy_t mdstrategy_malloc; 54 static d_open_t mdopen; 55 static d_close_t mdclose; 56 static d_ioctl_t mdioctl; 57 58 static struct dev_ops md_ops = { 59 { "md", CDEV_MAJOR, D_DISK | D_CANFREE | D_MEMDISK | D_TRACKCLOSE}, 60 .d_open = mdopen, 61 .d_close = mdclose, 62 .d_read = physread, 63 .d_write = physwrite, 64 .d_ioctl = mdioctl, 65 .d_strategy = mdstrategy, 66 }; 67 68 struct md_s { 69 int unit; 70 struct devstat stats; 71 struct bio_queue_head bio_queue; 72 struct disk disk; 73 cdev_t dev; 74 int busy; 75 enum { /* Memory disk type */ 76 MD_MALLOC, 77 MD_PRELOAD 78 } type; 79 unsigned nsect; 80 81 /* MD_MALLOC related fields */ 82 unsigned nsecp; 83 u_char **secp; 84 85 /* MD_PRELOAD related fields */ 86 u_char *pl_ptr; 87 unsigned pl_len; 88 TAILQ_ENTRY(md_s) link; 89 }; 90 TAILQ_HEAD(mdshead, md_s) mdlist = TAILQ_HEAD_INITIALIZER(mdlist); 91 92 static int mdunits; 93 static int refcnt; 94 95 static struct md_s *mdcreate(unsigned); 96 static void mdcreate_malloc(void); 97 static int mdinit(module_t, int, void *); 98 static void md_drvinit(void *); 99 static int md_drvcleanup(void); 100 101 static int 102 mdinit(module_t mod, int cmd, void *arg) 103 { 104 int ret = 0; 105 106 switch(cmd) { 107 case MOD_LOAD: 108 TAILQ_INIT(&mdlist); 109 md_drvinit(NULL); 110 break; 111 case MOD_UNLOAD: 112 ret = md_drvcleanup(); 113 break; 114 default: 115 ret = EINVAL; 116 break; 117 } 118 119 return (ret); 120 } 121 122 static int 123 mdopen(struct dev_open_args *ap) 124 { 125 cdev_t dev = ap->a_head.a_dev; 126 struct md_s *sc; 127 128 if (md_debug) 129 kprintf("mdopen(%s %x %x)\n", 130 devtoname(dev), ap->a_oflags, ap->a_devtype); 131 132 sc = dev->si_drv1; 133 if (sc->unit + 1 == mdunits) 134 mdcreate_malloc(); 135 136 atomic_add_int(&refcnt, 1); 137 return (0); 138 } 139 140 static int 141 mdclose(struct dev_close_args *ap) 142 { 143 cdev_t dev = ap->a_head.a_dev; 144 struct md_s *sc; 145 146 if (md_debug) 147 kprintf("mdclose(%s %x %x)\n", 148 devtoname(dev), ap->a_fflag, ap->a_devtype); 149 sc = dev->si_drv1; 150 atomic_add_int(&refcnt, -1); 151 152 return (0); 153 } 154 155 static int 156 mdioctl(struct dev_ioctl_args *ap) 157 { 158 cdev_t dev = ap->a_head.a_dev; 159 160 if (md_debug) 161 kprintf("mdioctl(%s %lx %p %x)\n", 162 devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag); 163 164 return (ENOIOCTL); 165 } 166 167 static int 168 mdstrategy(struct dev_strategy_args *ap) 169 { 170 cdev_t dev = ap->a_head.a_dev; 171 struct bio *bio = ap->a_bio; 172 struct buf *bp = bio->bio_buf; 173 struct md_s *sc; 174 175 if (md_debug > 1) { 176 kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n", 177 bp, devtoname(dev), bp->b_flags, 178 (long long)bio->bio_offset, 179 bp->b_bcount, bp->b_data); 180 } 181 bio->bio_driver_info = dev; 182 sc = dev->si_drv1; 183 if (sc->type == MD_MALLOC) { 184 mdstrategy_malloc(ap); 185 } else { 186 mdstrategy_preload(ap); 187 } 188 return(0); 189 } 190 191 192 static int 193 mdstrategy_malloc(struct dev_strategy_args *ap) 194 { 195 cdev_t dev = ap->a_head.a_dev; 196 struct bio *bio = ap->a_bio; 197 struct buf *bp = bio->bio_buf; 198 unsigned secno, nsec, secval, uc; 199 u_char *secp, **secpp, *dst; 200 struct md_s *sc; 201 int i; 202 203 if (md_debug > 1) 204 kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n", 205 bp, devtoname(dev), bp->b_flags, 206 (long long)bio->bio_offset, 207 bp->b_bcount, bp->b_data); 208 209 sc = dev->si_drv1; 210 211 crit_enter(); 212 213 bioqdisksort(&sc->bio_queue, bio); 214 215 if (sc->busy) { 216 crit_exit(); 217 return(0); 218 } 219 220 sc->busy++; 221 222 while (1) { 223 bio = bioq_first(&sc->bio_queue); 224 if (bio == NULL) { 225 crit_exit(); 226 break; 227 } 228 crit_exit(); 229 bioq_remove(&sc->bio_queue, bio); 230 bp = bio->bio_buf; 231 232 devstat_start_transaction(&sc->stats); 233 234 switch (bp->b_cmd) { 235 case BUF_CMD_FREEBLKS: 236 case BUF_CMD_READ: 237 case BUF_CMD_WRITE: 238 break; 239 default: 240 panic("md: bad b_cmd %d", bp->b_cmd); 241 } 242 243 nsec = bp->b_bcount >> DEV_BSHIFT; 244 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT); 245 dst = bp->b_data; 246 while (nsec--) { 247 if (secno < sc->nsecp) { 248 secpp = &sc->secp[secno]; 249 if ((u_int)(uintptr_t)*secpp > 255) { 250 secp = *secpp; 251 secval = 0; 252 } else { 253 secp = 0; 254 secval = (u_int)(uintptr_t)*secpp; 255 } 256 } else { 257 secpp = 0; 258 secp = 0; 259 secval = 0; 260 } 261 if (md_debug > 2) 262 kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval); 263 264 switch (bp->b_cmd) { 265 case BUF_CMD_FREEBLKS: 266 if (secpp) { 267 if (secp) 268 FREE(secp, M_MDSECT); 269 *secpp = 0; 270 } 271 break; 272 case BUF_CMD_READ: 273 if (secp) { 274 bcopy(secp, dst, DEV_BSIZE); 275 } else if (secval) { 276 for (i = 0; i < DEV_BSIZE; i++) 277 dst[i] = secval; 278 } else { 279 bzero(dst, DEV_BSIZE); 280 } 281 break; 282 case BUF_CMD_WRITE: 283 uc = dst[0]; 284 for (i = 1; i < DEV_BSIZE; i++) 285 if (dst[i] != uc) 286 break; 287 if (i == DEV_BSIZE && !uc) { 288 if (secp) 289 FREE(secp, M_MDSECT); 290 if (secpp) 291 *secpp = (u_char *)(uintptr_t)uc; 292 } else { 293 if (!secpp) { 294 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 295 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 296 FREE(sc->secp, M_MD); 297 sc->secp = secpp; 298 sc->nsecp = secno + nsec + 1; 299 secpp = &sc->secp[secno]; 300 } 301 if (i == DEV_BSIZE) { 302 if (secp) 303 FREE(secp, M_MDSECT); 304 *secpp = (u_char *)(uintptr_t)uc; 305 } else { 306 if (!secp) 307 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 308 bcopy(dst, secp, DEV_BSIZE); 309 310 *secpp = secp; 311 } 312 } 313 break; 314 default: 315 panic("md: bad b_cmd %d", bp->b_cmd); 316 317 } 318 secno++; 319 dst += DEV_BSIZE; 320 } 321 bp->b_resid = 0; 322 devstat_end_transaction_buf(&sc->stats, bp); 323 biodone(bio); 324 crit_enter(); 325 } 326 sc->busy = 0; 327 return(0); 328 } 329 330 331 static int 332 mdstrategy_preload(struct dev_strategy_args *ap) 333 { 334 cdev_t dev = ap->a_head.a_dev; 335 struct bio *bio = ap->a_bio; 336 struct buf *bp = bio->bio_buf; 337 struct md_s *sc; 338 339 if (md_debug > 1) 340 kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n", 341 bp, devtoname(dev), bp->b_flags, 342 (long long)bio->bio_offset, 343 bp->b_bcount, bp->b_data); 344 345 sc = dev->si_drv1; 346 347 crit_enter(); 348 349 bioqdisksort(&sc->bio_queue, bio); 350 351 if (sc->busy) { 352 crit_exit(); 353 return(0); 354 } 355 356 sc->busy++; 357 358 while (1) { 359 bio = bioq_first(&sc->bio_queue); 360 if (bio) 361 bioq_remove(&sc->bio_queue, bio); 362 crit_exit(); 363 if (bio == NULL) 364 break; 365 366 devstat_start_transaction(&sc->stats); 367 368 switch (bp->b_cmd) { 369 case BUF_CMD_FREEBLKS: 370 break; 371 case BUF_CMD_READ: 372 bcopy(sc->pl_ptr + bio->bio_offset, 373 bp->b_data, bp->b_bcount); 374 break; 375 case BUF_CMD_WRITE: 376 bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset, 377 bp->b_bcount); 378 break; 379 default: 380 panic("md: bad cmd %d\n", bp->b_cmd); 381 } 382 bp->b_resid = 0; 383 devstat_end_transaction_buf(&sc->stats, bp); 384 biodone(bio); 385 crit_enter(); 386 } 387 sc->busy = 0; 388 return(0); 389 } 390 391 static struct md_s * 392 mdcreate(unsigned length) 393 { 394 struct md_s *sc; 395 struct disk_info info; 396 397 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK | M_ZERO); 398 sc->unit = mdunits++; 399 bioq_init(&sc->bio_queue); 400 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 401 DEVSTAT_NO_ORDERED_TAGS, 402 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 403 DEVSTAT_PRIORITY_OTHER); 404 sc->dev = disk_create(sc->unit, &sc->disk, &md_ops); 405 sc->dev->si_drv1 = sc; 406 sc->dev->si_iosize_max = DFLTPHYS; 407 408 bzero(&info, sizeof(info)); 409 info.d_media_blksize = DEV_BSIZE; /* mandatory */ 410 info.d_media_blocks = length / DEV_BSIZE; 411 412 info.d_secpertrack = 1024; /* optional */ 413 info.d_nheads = 1; 414 info.d_secpercyl = info.d_secpertrack * info.d_nheads; 415 info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl); 416 disk_setdiskinfo(&sc->disk, &info); 417 TAILQ_INSERT_HEAD(&mdlist, sc, link); 418 419 return (sc); 420 } 421 422 423 static void 424 mdcreate_preload(u_char *image, unsigned length) 425 { 426 struct md_s *sc; 427 428 sc = mdcreate(length); 429 sc->type = MD_PRELOAD; 430 sc->nsect = length / DEV_BSIZE; 431 sc->pl_ptr = image; 432 sc->pl_len = length; 433 434 if (sc->unit == 0) 435 mdrootready = 1; 436 } 437 438 static void 439 mdcreate_malloc(void) 440 { 441 struct md_s *sc; 442 443 sc = mdcreate(MD_NSECT*DEV_BSIZE); 444 sc->type = MD_MALLOC; 445 446 sc->nsect = MD_NSECT; /* for now */ 447 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 448 sc->nsecp = 1; 449 kprintf("md%d: Malloc disk\n", sc->unit); 450 } 451 452 static int 453 md_drvcleanup(void) 454 { 455 456 int secno; 457 struct md_s *sc, *sc_temp; 458 459 if (atomic_fetchadd_int(&refcnt, 0) != 0) 460 return EBUSY; 461 462 /* 463 * Go through all the md devices, freeing up all the 464 * memory allocated for sectors, and the md_s struct 465 * itself. 466 */ 467 TAILQ_FOREACH_MUTABLE(sc, &mdlist, link, sc_temp) { 468 for (secno = 0; secno < sc->nsecp; secno++) { 469 if ((u_int)(uintptr_t)sc->secp[secno] > 255) 470 FREE(sc->secp[secno], M_MDSECT); 471 } 472 473 if (sc->dev != NULL) 474 disk_destroy(&sc->disk); 475 476 devstat_remove_entry(&sc->stats); 477 TAILQ_REMOVE(&mdlist, sc, link); 478 479 FREE(sc->secp, M_MD); 480 FREE(sc, M_MD); 481 } 482 483 return 0; 484 485 } 486 487 static void 488 md_drvinit(void *unused) 489 { 490 491 caddr_t mod; 492 caddr_t c; 493 u_char *ptr, *name, *type; 494 unsigned len; 495 496 #ifdef MD_ROOT_SIZE 497 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 498 #endif 499 mod = NULL; 500 while ((mod = preload_search_next_name(mod)) != NULL) { 501 name = (char *)preload_search_info(mod, MODINFO_NAME); 502 type = (char *)preload_search_info(mod, MODINFO_TYPE); 503 if (name == NULL) 504 continue; 505 if (type == NULL) 506 continue; 507 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 508 continue; 509 c = preload_search_info(mod, MODINFO_ADDR); 510 ptr = *(u_char **)c; 511 c = preload_search_info(mod, MODINFO_SIZE); 512 len = *(unsigned *)c; 513 kprintf("md%d: Preloaded image <%s> %d bytes at %p\n", 514 mdunits, name, len, ptr); 515 mdcreate_preload(ptr, len); 516 } 517 mdcreate_malloc(); 518 } 519 520 DEV_MODULE(md, mdinit, NULL); 521 522 #ifdef MD_ROOT 523 static void 524 md_takeroot(void *junk) 525 { 526 if (mdrootready) 527 rootdevnames[0] = "ufs:/dev/md0s0"; 528 } 529 530 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 531 #endif 532