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 30 #ifndef MD_NSECT 31 #define MD_NSECT (10000 * 2) 32 #endif 33 34 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk"); 35 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors"); 36 37 static int md_debug; 38 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, ""); 39 40 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE) 41 /* Image gets put here: */ 42 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here"; 43 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here"; 44 #endif 45 46 static int mdrootready; 47 48 static void mdcreate_malloc(void); 49 50 #define CDEV_MAJOR 95 51 52 static d_strategy_t mdstrategy; 53 static d_strategy_t mdstrategy_preload; 54 static d_strategy_t mdstrategy_malloc; 55 static d_open_t mdopen; 56 static d_ioctl_t mdioctl; 57 58 static struct dev_ops md_ops = { 59 { "md", CDEV_MAJOR, D_DISK | D_CANFREE | D_MEMDISK }, 60 .d_open = mdopen, 61 .d_close = nullclose, 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 {MD_MALLOC, MD_PRELOAD} type; 76 unsigned nsect; 77 78 /* MD_MALLOC related fields */ 79 unsigned nsecp; 80 u_char **secp; 81 82 /* MD_PRELOAD related fields */ 83 u_char *pl_ptr; 84 unsigned pl_len; 85 }; 86 87 static int mdunits; 88 89 static int 90 mdopen(struct dev_open_args *ap) 91 { 92 cdev_t dev = ap->a_head.a_dev; 93 struct md_s *sc; 94 #if 0 95 struct disk_info info; 96 #endif 97 98 if (md_debug) 99 kprintf("mdopen(%s %x %x)\n", 100 devtoname(dev), ap->a_oflags, ap->a_devtype); 101 102 sc = dev->si_drv1; 103 if (sc->unit + 1 == mdunits) 104 mdcreate_malloc(); 105 #if 0 106 bzero(&info, sizeof(info)); 107 info.d_media_blksize = DEV_BSIZE; /* mandatory */ 108 info.d_media_blocks = sc->nsect; 109 110 info.d_secpertrack = 1024; /* optional */ 111 info.d_nheads = 1; 112 info.d_secpercyl = info.d_secpertrack * info.d_nheads; 113 info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl); 114 disk_setdiskinfo(&sc->disk, &info); 115 #endif 116 return (0); 117 } 118 119 static int 120 mdioctl(struct dev_ioctl_args *ap) 121 { 122 cdev_t dev = ap->a_head.a_dev; 123 124 if (md_debug) 125 kprintf("mdioctl(%s %lx %p %x)\n", 126 devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag); 127 128 return (ENOIOCTL); 129 } 130 131 static int 132 mdstrategy(struct dev_strategy_args *ap) 133 { 134 cdev_t dev = ap->a_head.a_dev; 135 struct bio *bio = ap->a_bio; 136 struct buf *bp = bio->bio_buf; 137 struct md_s *sc; 138 139 if (md_debug > 1) { 140 kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n", 141 bp, devtoname(dev), bp->b_flags, 142 (long long)bio->bio_offset, 143 bp->b_bcount, bp->b_data); 144 } 145 bio->bio_driver_info = dev; 146 sc = dev->si_drv1; 147 if (sc->type == MD_MALLOC) { 148 mdstrategy_malloc(ap); 149 } else { 150 mdstrategy_preload(ap); 151 } 152 return(0); 153 } 154 155 156 static int 157 mdstrategy_malloc(struct dev_strategy_args *ap) 158 { 159 cdev_t dev = ap->a_head.a_dev; 160 struct bio *bio = ap->a_bio; 161 struct buf *bp = bio->bio_buf; 162 unsigned secno, nsec, secval, uc; 163 u_char *secp, **secpp, *dst; 164 struct md_s *sc; 165 int i; 166 167 if (md_debug > 1) 168 kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n", 169 bp, devtoname(dev), bp->b_flags, 170 (long long)bio->bio_offset, 171 bp->b_bcount, bp->b_data); 172 173 sc = dev->si_drv1; 174 175 crit_enter(); 176 177 bioqdisksort(&sc->bio_queue, bio); 178 179 if (sc->busy) { 180 crit_exit(); 181 return(0); 182 } 183 184 sc->busy++; 185 186 while (1) { 187 bio = bioq_first(&sc->bio_queue); 188 if (bio == NULL) { 189 crit_exit(); 190 break; 191 } 192 crit_exit(); 193 bioq_remove(&sc->bio_queue, bio); 194 bp = bio->bio_buf; 195 196 devstat_start_transaction(&sc->stats); 197 198 switch (bp->b_cmd) { 199 case BUF_CMD_FREEBLKS: 200 case BUF_CMD_READ: 201 case BUF_CMD_WRITE: 202 break; 203 default: 204 panic("md: bad b_cmd %d", bp->b_cmd); 205 } 206 207 nsec = bp->b_bcount >> DEV_BSHIFT; 208 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT); 209 dst = bp->b_data; 210 while (nsec--) { 211 if (secno < sc->nsecp) { 212 secpp = &sc->secp[secno]; 213 if ((u_int)(uintptr_t)*secpp > 255) { 214 secp = *secpp; 215 secval = 0; 216 } else { 217 secp = 0; 218 secval = (u_int)(uintptr_t)*secpp; 219 } 220 } else { 221 secpp = 0; 222 secp = 0; 223 secval = 0; 224 } 225 if (md_debug > 2) 226 kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval); 227 228 switch (bp->b_cmd) { 229 case BUF_CMD_FREEBLKS: 230 if (secpp) { 231 if (secp) 232 FREE(secp, M_MDSECT); 233 *secpp = 0; 234 } 235 break; 236 case BUF_CMD_READ: 237 if (secp) { 238 bcopy(secp, dst, DEV_BSIZE); 239 } else if (secval) { 240 for (i = 0; i < DEV_BSIZE; i++) 241 dst[i] = secval; 242 } else { 243 bzero(dst, DEV_BSIZE); 244 } 245 break; 246 case BUF_CMD_WRITE: 247 uc = dst[0]; 248 for (i = 1; i < DEV_BSIZE; i++) 249 if (dst[i] != uc) 250 break; 251 if (i == DEV_BSIZE && !uc) { 252 if (secp) 253 FREE(secp, M_MDSECT); 254 if (secpp) 255 *secpp = (u_char *)(uintptr_t)uc; 256 } else { 257 if (!secpp) { 258 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 259 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 260 FREE(sc->secp, M_MD); 261 sc->secp = secpp; 262 sc->nsecp = secno + nsec + 1; 263 secpp = &sc->secp[secno]; 264 } 265 if (i == DEV_BSIZE) { 266 if (secp) 267 FREE(secp, M_MDSECT); 268 *secpp = (u_char *)(uintptr_t)uc; 269 } else { 270 if (!secp) 271 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 272 bcopy(dst, secp, DEV_BSIZE); 273 274 *secpp = secp; 275 } 276 } 277 break; 278 default: 279 panic("md: bad b_cmd %d", bp->b_cmd); 280 281 } 282 secno++; 283 dst += DEV_BSIZE; 284 } 285 bp->b_resid = 0; 286 devstat_end_transaction_buf(&sc->stats, bp); 287 biodone(bio); 288 crit_enter(); 289 } 290 sc->busy = 0; 291 return(0); 292 } 293 294 295 static int 296 mdstrategy_preload(struct dev_strategy_args *ap) 297 { 298 cdev_t dev = ap->a_head.a_dev; 299 struct bio *bio = ap->a_bio; 300 struct buf *bp = bio->bio_buf; 301 struct md_s *sc; 302 303 if (md_debug > 1) 304 kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n", 305 bp, devtoname(dev), bp->b_flags, 306 (long long)bio->bio_offset, 307 bp->b_bcount, bp->b_data); 308 309 sc = dev->si_drv1; 310 311 crit_enter(); 312 313 bioqdisksort(&sc->bio_queue, bio); 314 315 if (sc->busy) { 316 crit_exit(); 317 return(0); 318 } 319 320 sc->busy++; 321 322 while (1) { 323 bio = bioq_first(&sc->bio_queue); 324 if (bio) 325 bioq_remove(&sc->bio_queue, bio); 326 crit_exit(); 327 if (bio == NULL) 328 break; 329 330 devstat_start_transaction(&sc->stats); 331 332 switch (bp->b_cmd) { 333 case BUF_CMD_FREEBLKS: 334 break; 335 case BUF_CMD_READ: 336 bcopy(sc->pl_ptr + bio->bio_offset, 337 bp->b_data, bp->b_bcount); 338 break; 339 case BUF_CMD_WRITE: 340 bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset, 341 bp->b_bcount); 342 break; 343 default: 344 panic("md: bad cmd %d\n", bp->b_cmd); 345 } 346 bp->b_resid = 0; 347 devstat_end_transaction_buf(&sc->stats, bp); 348 biodone(bio); 349 crit_enter(); 350 } 351 sc->busy = 0; 352 return(0); 353 } 354 355 static struct md_s * 356 mdcreate(unsigned length) 357 { 358 struct md_s *sc; 359 struct disk_info info; 360 361 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK | M_ZERO); 362 sc->unit = mdunits++; 363 bioq_init(&sc->bio_queue); 364 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 365 DEVSTAT_NO_ORDERED_TAGS, 366 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 367 DEVSTAT_PRIORITY_OTHER); 368 sc->dev = disk_create(sc->unit, &sc->disk, &md_ops); 369 sc->dev->si_drv1 = sc; 370 sc->dev->si_iosize_max = DFLTPHYS; 371 372 bzero(&info, sizeof(info)); 373 info.d_media_blksize = DEV_BSIZE; /* mandatory */ 374 info.d_media_blocks = length / DEV_BSIZE; 375 376 info.d_secpertrack = 1024; /* optional */ 377 info.d_nheads = 1; 378 info.d_secpercyl = info.d_secpertrack * info.d_nheads; 379 info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl); 380 disk_setdiskinfo(&sc->disk, &info); 381 382 return (sc); 383 } 384 385 static void 386 mdcreate_preload(u_char *image, unsigned length) 387 { 388 struct md_s *sc; 389 390 sc = mdcreate(length); 391 sc->type = MD_PRELOAD; 392 sc->nsect = length / DEV_BSIZE; 393 sc->pl_ptr = image; 394 sc->pl_len = length; 395 396 if (sc->unit == 0) 397 mdrootready = 1; 398 } 399 400 static void 401 mdcreate_malloc(void) 402 { 403 struct md_s *sc; 404 405 sc = mdcreate(0); 406 sc->type = MD_MALLOC; 407 408 sc->nsect = MD_NSECT; /* for now */ 409 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK | M_ZERO); 410 sc->nsecp = 1; 411 kprintf("md%d: Malloc disk\n", sc->unit); 412 } 413 414 static void 415 md_drvinit(void *unused) 416 { 417 418 caddr_t mod; 419 caddr_t c; 420 u_char *ptr, *name, *type; 421 unsigned len; 422 423 #ifdef MD_ROOT_SIZE 424 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 425 #endif 426 mod = NULL; 427 while ((mod = preload_search_next_name(mod)) != NULL) { 428 name = (char *)preload_search_info(mod, MODINFO_NAME); 429 type = (char *)preload_search_info(mod, MODINFO_TYPE); 430 if (name == NULL) 431 continue; 432 if (type == NULL) 433 continue; 434 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 435 continue; 436 c = preload_search_info(mod, MODINFO_ADDR); 437 ptr = *(u_char **)c; 438 c = preload_search_info(mod, MODINFO_SIZE); 439 len = *(unsigned *)c; 440 kprintf("md%d: Preloaded image <%s> %d bytes at %p\n", 441 mdunits, name, len, ptr); 442 mdcreate_preload(ptr, len); 443 } 444 mdcreate_malloc(); 445 } 446 447 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL) 448 449 #ifdef MD_ROOT 450 static void 451 md_takeroot(void *junk) 452 { 453 if (mdrootready) 454 rootdevnames[0] = "ufs:/dev/md0s0"; 455 } 456 457 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 458 #endif 459