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_mfs.h" /* We have adopted some tasks from MFS */ 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 27 #ifndef MD_NSECT 28 #define MD_NSECT (10000 * 2) 29 #endif 30 31 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk"); 32 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors"); 33 34 static int md_debug; 35 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, ""); 36 37 #if defined(MFS_ROOT) && !defined(MD_ROOT) 38 #define MD_ROOT MFS_ROOT 39 #warning "option MFS_ROOT has been superceeded by MD_ROOT" 40 #endif 41 42 #if defined(MFS_ROOT_SIZE) && !defined(MD_ROOT_SIZE) 43 #define MD_ROOT_SIZE MFS_ROOT_SIZE 44 #warning "option MFS_ROOT_SIZE has been superceeded by MD_ROOT_SIZE" 45 #endif 46 47 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE) 48 /* Image gets put here: */ 49 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here"; 50 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here"; 51 #endif 52 53 static int mdrootready; 54 55 static void mdcreate_malloc(void); 56 57 #define CDEV_MAJOR 95 58 #define BDEV_MAJOR 22 59 60 static d_strategy_t mdstrategy; 61 static d_strategy_t mdstrategy_preload; 62 static d_strategy_t mdstrategy_malloc; 63 static d_open_t mdopen; 64 static d_ioctl_t mdioctl; 65 66 static struct cdevsw md_cdevsw = { 67 /* open */ mdopen, 68 /* close */ nullclose, 69 /* read */ physread, 70 /* write */ physwrite, 71 /* ioctl */ mdioctl, 72 /* poll */ nopoll, 73 /* mmap */ nommap, 74 /* strategy */ mdstrategy, 75 /* name */ "md", 76 /* maj */ CDEV_MAJOR, 77 /* dump */ nodump, 78 /* psize */ nopsize, 79 /* flags */ D_DISK | D_CANFREE | D_MEMDISK, 80 /* bmaj */ BDEV_MAJOR 81 }; 82 83 static struct cdevsw mddisk_cdevsw; 84 85 struct md_s { 86 int unit; 87 struct devstat stats; 88 struct buf_queue_head buf_queue; 89 struct disk disk; 90 dev_t dev; 91 int busy; 92 enum {MD_MALLOC, MD_PRELOAD} type; 93 unsigned nsect; 94 95 /* MD_MALLOC related fields */ 96 unsigned nsecp; 97 u_char **secp; 98 99 /* MD_PRELOAD related fields */ 100 u_char *pl_ptr; 101 unsigned pl_len; 102 }; 103 104 static int mdunits; 105 106 static int 107 mdopen(dev_t dev, int flag, int fmt, struct proc *p) 108 { 109 struct md_s *sc; 110 struct disklabel *dl; 111 112 if (md_debug) 113 printf("mdopen(%s %x %x %p)\n", 114 devtoname(dev), flag, fmt, p); 115 116 sc = dev->si_drv1; 117 if (sc->unit + 1 == mdunits) 118 mdcreate_malloc(); 119 120 dl = &sc->disk.d_label; 121 bzero(dl, sizeof(*dl)); 122 dl->d_secsize = DEV_BSIZE; 123 dl->d_nsectors = 1024; 124 dl->d_ntracks = 1; 125 dl->d_secpercyl = dl->d_nsectors * dl->d_ntracks; 126 dl->d_secperunit = sc->nsect; 127 dl->d_ncylinders = dl->d_secperunit / dl->d_secpercyl; 128 return (0); 129 } 130 131 static int 132 mdioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p) 133 { 134 135 if (md_debug) 136 printf("mdioctl(%s %lx %p %x %p)\n", 137 devtoname(dev), cmd, addr, flags, p); 138 139 return (ENOIOCTL); 140 } 141 142 static void 143 mdstrategy(struct buf *bp) 144 { 145 struct md_s *sc; 146 147 if (md_debug > 1) 148 printf("mdstrategy(%p) %s %lx, %d, %ld, %p)\n", 149 bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno, 150 bp->b_bcount / DEV_BSIZE, bp->b_data); 151 152 sc = bp->b_dev->si_drv1; 153 if (sc->type == MD_MALLOC) { 154 mdstrategy_malloc(bp); 155 } else { 156 mdstrategy_preload(bp); 157 } 158 return; 159 } 160 161 162 static void 163 mdstrategy_malloc(struct buf *bp) 164 { 165 int s, i; 166 struct md_s *sc; 167 devstat_trans_flags dop; 168 u_char *secp, **secpp, *dst; 169 unsigned secno, nsec, secval, uc; 170 171 if (md_debug > 1) 172 printf("mdstrategy_malloc(%p) %s %lx, %d, %ld, %p)\n", 173 bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno, 174 bp->b_bcount / DEV_BSIZE, bp->b_data); 175 176 sc = bp->b_dev->si_drv1; 177 178 s = splbio(); 179 180 bufqdisksort(&sc->buf_queue, bp); 181 182 if (sc->busy) { 183 splx(s); 184 return; 185 } 186 187 sc->busy++; 188 189 while (1) { 190 bp = bufq_first(&sc->buf_queue); 191 if (bp) 192 bufq_remove(&sc->buf_queue, bp); 193 splx(s); 194 if (!bp) 195 break; 196 197 devstat_start_transaction(&sc->stats); 198 199 if (bp->b_flags & B_FREEBUF) 200 dop = DEVSTAT_NO_DATA; 201 else if (bp->b_flags & B_READ) 202 dop = DEVSTAT_READ; 203 else 204 dop = DEVSTAT_WRITE; 205 206 nsec = bp->b_bcount / DEV_BSIZE; 207 secno = bp->b_pblkno; 208 dst = bp->b_data; 209 while (nsec--) { 210 211 if (secno < sc->nsecp) { 212 secpp = &sc->secp[secno]; 213 if ((u_int)*secpp > 255) { 214 secp = *secpp; 215 secval = 0; 216 } else { 217 secp = 0; 218 secval = (u_int) *secpp; 219 } 220 } else { 221 secpp = 0; 222 secp = 0; 223 secval = 0; 224 } 225 if (md_debug > 2) 226 printf("%lx %p %p %d\n", bp->b_flags, secpp, secp, secval); 227 228 if (bp->b_flags & B_FREEBUF) { 229 if (secpp) { 230 if (secp) 231 FREE(secp, M_MDSECT); 232 *secpp = 0; 233 } 234 } else if (bp->b_flags & B_READ) { 235 if (secp) { 236 bcopy(secp, dst, DEV_BSIZE); 237 } else if (secval) { 238 for (i = 0; i < DEV_BSIZE; i++) 239 dst[i] = secval; 240 } else { 241 bzero(dst, DEV_BSIZE); 242 } 243 } else { 244 uc = dst[0]; 245 for (i = 1; i < DEV_BSIZE; i++) 246 if (dst[i] != uc) 247 break; 248 if (i == DEV_BSIZE && !uc) { 249 if (secp) 250 FREE(secp, M_MDSECT); 251 if (secpp) 252 *secpp = (u_char *)uc; 253 } else { 254 if (!secpp) { 255 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK); 256 bzero(secpp, (secno + nsec + 1) * sizeof(u_char *)); 257 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 258 FREE(sc->secp, M_MD); 259 sc->secp = secpp; 260 sc->nsecp = secno + nsec + 1; 261 secpp = &sc->secp[secno]; 262 } 263 if (i == DEV_BSIZE) { 264 if (secp) 265 FREE(secp, M_MDSECT); 266 *secpp = (u_char *)uc; 267 } else { 268 if (!secp) 269 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 270 bcopy(dst, secp, DEV_BSIZE); 271 272 *secpp = secp; 273 } 274 } 275 } 276 secno++; 277 dst += DEV_BSIZE; 278 } 279 bp->b_resid = 0; 280 devstat_end_transaction_buf(&sc->stats, bp); 281 biodone(bp); 282 s = splbio(); 283 } 284 sc->busy = 0; 285 return; 286 } 287 288 289 static void 290 mdstrategy_preload(struct buf *bp) 291 { 292 int s; 293 struct md_s *sc; 294 devstat_trans_flags dop; 295 296 if (md_debug > 1) 297 printf("mdstrategy_preload(%p) %s %lx, %d, %ld, %p)\n", 298 bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno, 299 bp->b_bcount / DEV_BSIZE, bp->b_data); 300 301 sc = bp->b_dev->si_drv1; 302 303 s = splbio(); 304 305 bufqdisksort(&sc->buf_queue, bp); 306 307 if (sc->busy) { 308 splx(s); 309 return; 310 } 311 312 sc->busy++; 313 314 while (1) { 315 bp = bufq_first(&sc->buf_queue); 316 if (bp) 317 bufq_remove(&sc->buf_queue, bp); 318 splx(s); 319 if (!bp) 320 break; 321 322 devstat_start_transaction(&sc->stats); 323 324 if (bp->b_flags & B_FREEBUF) { 325 dop = DEVSTAT_NO_DATA; 326 } else if (bp->b_flags & B_READ) { 327 dop = DEVSTAT_READ; 328 bcopy(sc->pl_ptr + (bp->b_pblkno << DEV_BSHIFT), bp->b_data, bp->b_bcount); 329 } else { 330 dop = DEVSTAT_WRITE; 331 bcopy(bp->b_data, sc->pl_ptr + (bp->b_pblkno << DEV_BSHIFT), bp->b_bcount); 332 } 333 bp->b_resid = 0; 334 devstat_end_transaction_buf(&sc->stats, bp); 335 biodone(bp); 336 s = splbio(); 337 } 338 sc->busy = 0; 339 return; 340 } 341 342 static struct md_s * 343 mdcreate(void) 344 { 345 struct md_s *sc; 346 347 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK); 348 bzero(sc, sizeof(*sc)); 349 sc->unit = mdunits++; 350 bufq_init(&sc->buf_queue); 351 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 352 DEVSTAT_NO_ORDERED_TAGS, 353 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 354 DEVSTAT_PRIORITY_OTHER); 355 sc->dev = disk_create(sc->unit, &sc->disk, 0, &md_cdevsw, &mddisk_cdevsw); 356 sc->dev->si_drv1 = sc; 357 return (sc); 358 } 359 360 static void 361 mdcreate_preload(u_char *image, unsigned length) 362 { 363 struct md_s *sc; 364 365 sc = mdcreate(); 366 sc->type = MD_PRELOAD; 367 sc->nsect = length / DEV_BSIZE; 368 sc->pl_ptr = image; 369 sc->pl_len = length; 370 371 if (sc->unit == 0) 372 mdrootready = 1; 373 } 374 375 static void 376 mdcreate_malloc(void) 377 { 378 struct md_s *sc; 379 380 sc = mdcreate(); 381 sc->type = MD_MALLOC; 382 383 sc->nsect = MD_NSECT; /* for now */ 384 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK); 385 bzero(sc->secp, sizeof(u_char *)); 386 sc->nsecp = 1; 387 printf("md%d: Malloc disk\n", sc->unit); 388 } 389 390 static void 391 md_drvinit(void *unused) 392 { 393 394 caddr_t mod; 395 caddr_t c; 396 u_char *ptr, *name, *type; 397 unsigned len; 398 399 #ifdef MD_ROOT_SIZE 400 mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024); 401 #endif 402 mod = NULL; 403 while ((mod = preload_search_next_name(mod)) != NULL) { 404 name = (char *)preload_search_info(mod, MODINFO_NAME); 405 type = (char *)preload_search_info(mod, MODINFO_TYPE); 406 if (name == NULL) 407 continue; 408 if (type == NULL) 409 continue; 410 if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) 411 continue; 412 c = preload_search_info(mod, MODINFO_ADDR); 413 ptr = *(u_char **)c; 414 c = preload_search_info(mod, MODINFO_SIZE); 415 len = *(unsigned *)c; 416 printf("md%d: Preloaded image <%s> %d bytes at %p\n", 417 mdunits, name, len, ptr); 418 mdcreate_preload(ptr, len); 419 } 420 mdcreate_malloc(); 421 } 422 423 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL) 424 425 #ifdef MD_ROOT 426 static void 427 md_takeroot(void *junk) 428 { 429 if (mdrootready) 430 rootdevnames[0] = "ufs:/dev/md0c"; 431 } 432 433 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL); 434 #endif 435