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 "Enable debug output for memory disk devices"); 41 42 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE) 43 /* Image gets put here: */ 44 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here"; 45 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here"; 46 #endif 47 48 static int mdrootready; 49 50 static d_strategy_t mdstrategy; 51 static d_strategy_t mdstrategy_preload; 52 static d_strategy_t mdstrategy_malloc; 53 static d_open_t mdopen; 54 static d_close_t mdclose; 55 static d_ioctl_t mdioctl; 56 57 static struct dev_ops md_ops = { 58 { "md", 0, D_DISK | D_CANFREE | D_MEMDISK | D_TRACKCLOSE}, 59 .d_open = mdopen, 60 .d_close = mdclose, 61 .d_read = physread, 62 .d_write = physwrite, 63 .d_ioctl = mdioctl, 64 .d_strategy = mdstrategy, 65 }; 66 67 struct md_s { 68 int unit; 69 struct devstat stats; 70 struct bio_queue_head bio_queue; 71 struct disk disk; 72 cdev_t dev; 73 int busy; 74 enum { /* Memory disk type */ 75 MD_MALLOC, 76 MD_PRELOAD 77 } type; 78 unsigned nsect; 79 80 /* MD_MALLOC related fields */ 81 unsigned nsecp; 82 u_char **secp; 83 84 /* MD_PRELOAD related fields */ 85 u_char *pl_ptr; 86 unsigned pl_len; 87 TAILQ_ENTRY(md_s) link; 88 }; 89 TAILQ_HEAD(mdshead, md_s) mdlist = TAILQ_HEAD_INITIALIZER(mdlist); 90 91 static int mdunits; 92 static int refcnt; 93 94 static struct md_s *mdcreate(unsigned); 95 static void mdcreate_malloc(void); 96 static int mdinit(module_t, int, void *); 97 static void md_drvinit(void *); 98 static int md_drvcleanup(void); 99 100 static int 101 mdinit(module_t mod, int cmd, void *arg) 102 { 103 int ret = 0; 104 105 switch(cmd) { 106 case MOD_LOAD: 107 TAILQ_INIT(&mdlist); 108 md_drvinit(NULL); 109 break; 110 case MOD_UNLOAD: 111 ret = md_drvcleanup(); 112 break; 113 default: 114 ret = EINVAL; 115 break; 116 } 117 118 return (ret); 119 } 120 121 static int 122 mdopen(struct dev_open_args *ap) 123 { 124 cdev_t dev = ap->a_head.a_dev; 125 struct md_s *sc; 126 127 if (md_debug) 128 kprintf("mdopen(%s %x %x)\n", 129 devtoname(dev), ap->a_oflags, ap->a_devtype); 130 131 sc = dev->si_drv1; 132 if (sc->unit + 1 == mdunits) 133 mdcreate_malloc(); 134 135 atomic_add_int(&refcnt, 1); 136 return (0); 137 } 138 139 static int 140 mdclose(struct dev_close_args *ap) 141 { 142 cdev_t dev = ap->a_head.a_dev; 143 struct md_s *sc; 144 145 if (md_debug) 146 kprintf("mdclose(%s %x %x)\n", 147 devtoname(dev), ap->a_fflag, ap->a_devtype); 148 sc = dev->si_drv1; 149 atomic_add_int(&refcnt, -1); 150 151 return (0); 152 } 153 154 static int 155 mdioctl(struct dev_ioctl_args *ap) 156 { 157 cdev_t dev = ap->a_head.a_dev; 158 159 if (md_debug) 160 kprintf("mdioctl(%s %lx %p %x)\n", 161 devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag); 162 163 return (ENOIOCTL); 164 } 165 166 static int 167 mdstrategy(struct dev_strategy_args *ap) 168 { 169 cdev_t dev = ap->a_head.a_dev; 170 struct bio *bio = ap->a_bio; 171 struct buf *bp = bio->bio_buf; 172 struct md_s *sc; 173 174 if (md_debug > 1) { 175 kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n", 176 bp, devtoname(dev), bp->b_flags, 177 (long long)bio->bio_offset, 178 bp->b_bcount, bp->b_data); 179 } 180 bio->bio_driver_info = dev; 181 sc = dev->si_drv1; 182 if (sc->type == MD_MALLOC) { 183 mdstrategy_malloc(ap); 184 } else { 185 mdstrategy_preload(ap); 186 } 187 return(0); 188 } 189 190 191 static int 192 mdstrategy_malloc(struct dev_strategy_args *ap) 193 { 194 cdev_t dev = ap->a_head.a_dev; 195 struct bio *bio = ap->a_bio; 196 struct buf *bp = bio->bio_buf; 197 unsigned secno, nsec, secval, uc; 198 u_char *secp, **secpp, *dst; 199 struct md_s *sc; 200 int i; 201 202 if (md_debug > 1) 203 kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n", 204 bp, devtoname(dev), bp->b_flags, 205 (long long)bio->bio_offset, 206 bp->b_bcount, bp->b_data); 207 208 sc = dev->si_drv1; 209 210 crit_enter(); 211 212 bioqdisksort(&sc->bio_queue, bio); 213 214 if (sc->busy) { 215 crit_exit(); 216 return(0); 217 } 218 219 sc->busy++; 220 221 while (1) { 222 bio = bioq_first(&sc->bio_queue); 223 if (bio == NULL) { 224 crit_exit(); 225 break; 226 } 227 crit_exit(); 228 bioq_remove(&sc->bio_queue, bio); 229 bp = bio->bio_buf; 230 231 devstat_start_transaction(&sc->stats); 232 233 switch (bp->b_cmd) { 234 case BUF_CMD_FREEBLKS: 235 case BUF_CMD_READ: 236 case BUF_CMD_WRITE: 237 break; 238 default: 239 panic("md: bad b_cmd %d", bp->b_cmd); 240 } 241 242 nsec = bp->b_bcount >> DEV_BSHIFT; 243 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT); 244 dst = bp->b_data; 245 while (nsec--) { 246 if (secno < sc->nsecp) { 247 secpp = &sc->secp[secno]; 248 if ((u_int)(uintptr_t)*secpp > 255) { 249 secp = *secpp; 250 secval = 0; 251 } else { 252 secp = NULL; 253 secval = (u_int)(uintptr_t)*secpp; 254 } 255 } else { 256 secpp = NULL; 257 secp = NULL; 258 secval = 0; 259 } 260 if (md_debug > 2) 261 kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval); 262 263 switch (bp->b_cmd) { 264 case BUF_CMD_FREEBLKS: 265 if (secpp) { 266 if (secp) 267 kfree(secp, M_MDSECT); 268 *secpp = NULL; 269 } 270 break; 271 case BUF_CMD_READ: 272 if (secp) { 273 bcopy(secp, dst, DEV_BSIZE); 274 } else if (secval) { 275 for (i = 0; i < DEV_BSIZE; i++) 276 dst[i] = secval; 277 } else { 278 bzero(dst, DEV_BSIZE); 279 } 280 break; 281 case BUF_CMD_WRITE: 282 uc = dst[0]; 283 for (i = 1; i < DEV_BSIZE; i++) 284 if (dst[i] != uc) 285 break; 286 if (i == DEV_BSIZE && !uc) { 287 if (secp) 288 kfree(secp, M_MDSECT); 289 if (secpp) 290 *secpp = (u_char *)(uintptr_t)uc; 291 } else { 292 if (!secpp) { 293 secpp = kmalloc((secno + nsec + 1) * sizeof(u_char *), 294 M_MD, 295 M_WAITOK | M_ZERO); 296 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 297 kfree(sc->secp, M_MD); 298 sc->secp = secpp; 299 sc->nsecp = secno + nsec + 1; 300 secpp = &sc->secp[secno]; 301 } 302 if (i == DEV_BSIZE) { 303 if (secp) 304 kfree(secp, M_MDSECT); 305 *secpp = (u_char *)(uintptr_t)uc; 306 } else { 307 if (!secp) 308 secp = kmalloc(DEV_BSIZE, 309 M_MDSECT, 310 M_WAITOK); 311 bcopy(dst, secp, DEV_BSIZE); 312 313 *secpp = secp; 314 } 315 } 316 break; 317 default: 318 panic("md: bad b_cmd %d", bp->b_cmd); 319 320 } 321 secno++; 322 dst += DEV_BSIZE; 323 } 324 bp->b_resid = 0; 325 devstat_end_transaction_buf(&sc->stats, bp); 326 biodone(bio); 327 crit_enter(); 328 } 329 sc->busy = 0; 330 return(0); 331 } 332 333 334 static int 335 mdstrategy_preload(struct dev_strategy_args *ap) 336 { 337 cdev_t dev = ap->a_head.a_dev; 338 struct bio *bio = ap->a_bio; 339 struct buf *bp = bio->bio_buf; 340 struct md_s *sc; 341 342 if (md_debug > 1) 343 kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n", 344 bp, devtoname(dev), bp->b_flags, 345 (long long)bio->bio_offset, 346 bp->b_bcount, bp->b_data); 347 348 sc = dev->si_drv1; 349 350 crit_enter(); 351 352 bioqdisksort(&sc->bio_queue, bio); 353 354 if (sc->busy) { 355 crit_exit(); 356 return(0); 357 } 358 359 sc->busy++; 360 361 while (1) { 362 bio = bioq_takefirst(&sc->bio_queue); 363 crit_exit(); 364 if (bio == NULL) 365 break; 366 367 devstat_start_transaction(&sc->stats); 368 369 switch (bp->b_cmd) { 370 case BUF_CMD_FREEBLKS: 371 break; 372 case BUF_CMD_READ: 373 bcopy(sc->pl_ptr + bio->bio_offset, 374 bp->b_data, bp->b_bcount); 375 break; 376 case BUF_CMD_WRITE: 377 bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset, 378 bp->b_bcount); 379 break; 380 default: 381 panic("md: bad cmd %d\n", bp->b_cmd); 382 } 383 bp->b_resid = 0; 384 devstat_end_transaction_buf(&sc->stats, bp); 385 biodone(bio); 386 crit_enter(); 387 } 388 sc->busy = 0; 389 return(0); 390 } 391 392 static struct md_s * 393 mdcreate(unsigned length) 394 { 395 struct md_s *sc; 396 struct disk_info info; 397 398 sc = kmalloc(sizeof(*sc), M_MD, M_WAITOK | M_ZERO); 399 sc->unit = mdunits++; 400 bioq_init(&sc->bio_queue); 401 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 402 DEVSTAT_NO_ORDERED_TAGS, 403 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 404 DEVSTAT_PRIORITY_OTHER); 405 sc->dev = disk_create(sc->unit, &sc->disk, &md_ops); 406 sc->dev->si_drv1 = sc; 407 sc->dev->si_iosize_max = DFLTPHYS; 408 disk_setdisktype(&sc->disk, "memory"); 409 410 bzero(&info, sizeof(info)); 411 info.d_media_blksize = DEV_BSIZE; /* mandatory */ 412 info.d_media_blocks = length / DEV_BSIZE; 413 414 info.d_secpertrack = 1024; /* optional */ 415 info.d_nheads = 1; 416 info.d_secpercyl = info.d_secpertrack * info.d_nheads; 417 info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl); 418 disk_setdiskinfo(&sc->disk, &info); 419 TAILQ_INSERT_HEAD(&mdlist, sc, link); 420 421 return (sc); 422 } 423 424 425 static void 426 mdcreate_preload(u_char *image, unsigned length) 427 { 428 struct md_s *sc; 429 430 sc = mdcreate(length); 431 sc->type = MD_PRELOAD; 432 sc->nsect = length / DEV_BSIZE; 433 sc->pl_ptr = image; 434 sc->pl_len = length; 435 436 if (sc->unit == 0) 437 mdrootready = 1; 438 } 439 440 static void 441 mdcreate_malloc(void) 442 { 443 struct md_s *sc; 444 445 sc = mdcreate(MD_NSECT*DEV_BSIZE); 446 sc->type = MD_MALLOC; 447 448 sc->nsect = MD_NSECT; /* for now */ 449 sc->secp = kmalloc(sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 450 sc->nsecp = 1; 451 kprintf("md%d: Malloc disk\n", sc->unit); 452 } 453 454 static int 455 md_drvcleanup(void) 456 { 457 458 int secno; 459 struct md_s *sc, *sc_temp; 460 461 if (atomic_fetchadd_int(&refcnt, 0) != 0) 462 return EBUSY; 463 464 /* 465 * Go through all the md devices, freeing up all the 466 * memory allocated for sectors, and the md_s struct 467 * itself. 468 */ 469 TAILQ_FOREACH_MUTABLE(sc, &mdlist, link, sc_temp) { 470 for (secno = 0; secno < sc->nsecp; secno++) { 471 if ((u_int)(uintptr_t)sc->secp[secno] > 255) 472 kfree(sc->secp[secno], M_MDSECT); 473 } 474 475 if (sc->dev != NULL) 476 disk_destroy(&sc->disk); 477 478 devstat_remove_entry(&sc->stats); 479 TAILQ_REMOVE(&mdlist, sc, link); 480 481 kfree(sc->secp, M_MD); 482 kfree(sc, M_MD); 483 } 484 485 return 0; 486 487 } 488 489 static void 490 md_drvinit(void *unused) 491 { 492 493 caddr_t mod; 494 caddr_t c; 495 u_char *ptr, *name, *type; 496 unsigned len; 497 498 #ifdef MD_ROOT_SIZE 499 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 500 #endif 501 mod = NULL; 502 while ((mod = preload_search_next_name(mod)) != NULL) { 503 name = (char *)preload_search_info(mod, MODINFO_NAME); 504 type = (char *)preload_search_info(mod, MODINFO_TYPE); 505 if (name == NULL) 506 continue; 507 if (type == NULL) 508 continue; 509 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 510 continue; 511 c = preload_search_info(mod, MODINFO_ADDR); 512 ptr = *(u_char **)c; 513 c = preload_search_info(mod, MODINFO_SIZE); 514 len = *(unsigned *)c; 515 kprintf("md%d: Preloaded image <%s> %d bytes at %p\n", 516 mdunits, name, len, ptr); 517 mdcreate_preload(ptr, len); 518 } 519 mdcreate_malloc(); 520 } 521 522 DEV_MODULE(md, mdinit, NULL); 523 524 #ifdef MD_ROOT 525 static void 526 md_takeroot(void *junk) 527 { 528 if (mdrootready) 529 rootdevnames[0] = "ufs:/dev/md0s0"; 530 } 531 532 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 533 #endif 534