md.c revision 1.62
1 /* $NetBSD: md.c,v 1.62 2010/01/21 02:14:42 dyoung Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Gordon W. Ross, Leo Weppelman. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * This implements a general-purpose memory-disk. 30 * See md.h for notes on the config types. 31 * 32 * Note that this driver provides the same functionality 33 * as the MFS filesystem hack, but this is better because 34 * you can use this for any filesystem type you'd like! 35 * 36 * Credit for most of the kmem ramdisk code goes to: 37 * Leo Weppelman (atari) and Phil Nelson (pc532) 38 * Credit for the ideas behind the "user space memory" code goes 39 * to the authors of the MFS implementation. 40 */ 41 42 #include <sys/cdefs.h> 43 __KERNEL_RCSID(0, "$NetBSD: md.c,v 1.62 2010/01/21 02:14:42 dyoung Exp $"); 44 45 #include "opt_md.h" 46 #include "opt_tftproot.h" 47 48 #include <sys/param.h> 49 #include <sys/kernel.h> 50 #include <sys/malloc.h> 51 #include <sys/systm.h> 52 #include <sys/buf.h> 53 #include <sys/bufq.h> 54 #include <sys/device.h> 55 #include <sys/disk.h> 56 #include <sys/stat.h> 57 #include <sys/proc.h> 58 #include <sys/conf.h> 59 #include <sys/disklabel.h> 60 61 #include <uvm/uvm_extern.h> 62 63 #include <dev/md.h> 64 65 /* 66 * The user-space functionality is included by default. 67 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 68 */ 69 #ifndef MEMORY_DISK_SERVER 70 #error MEMORY_DISK_SERVER should be defined by opt_md.h 71 #endif /* MEMORY_DISK_SERVER */ 72 73 /* 74 * We should use the raw partition for ioctl. 75 */ 76 #define MD_UNIT(unit) DISKUNIT(unit) 77 78 /* autoconfig stuff... */ 79 80 struct md_softc { 81 struct disk sc_dkdev; /* hook for generic disk handling */ 82 struct md_conf sc_md; 83 struct bufq_state *sc_buflist; 84 }; 85 /* shorthand for fields in sc_md: */ 86 #define sc_addr sc_md.md_addr 87 #define sc_size sc_md.md_size 88 #define sc_type sc_md.md_type 89 90 void mdattach(int); 91 92 static void md_attach(device_t, device_t, void *); 93 static int md_detach(device_t, int); 94 95 static dev_type_open(mdopen); 96 static dev_type_close(mdclose); 97 static dev_type_read(mdread); 98 static dev_type_write(mdwrite); 99 static dev_type_ioctl(mdioctl); 100 static dev_type_strategy(mdstrategy); 101 static dev_type_size(mdsize); 102 103 const struct bdevsw md_bdevsw = { 104 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK 105 }; 106 107 const struct cdevsw md_cdevsw = { 108 mdopen, mdclose, mdread, mdwrite, mdioctl, 109 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 110 }; 111 112 static struct dkdriver mddkdriver = { mdstrategy, NULL }; 113 114 extern struct cfdriver md_cd; 115 CFATTACH_DECL3_NEW(md, sizeof(struct md_softc), 116 0, md_attach, md_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN); 117 118 extern size_t md_root_size; 119 120 /* 121 * This is called if we are configured as a pseudo-device 122 */ 123 void 124 mdattach(int n) 125 { 126 int i; 127 cfdata_t cf; 128 129 #ifdef TFTPROOT 130 /* 131 * Attachement of md0 must be done after md_root_setconf(), 132 * because the RAMdisk is not loaded yet. 133 */ 134 if (md_root_size == 0) 135 return; 136 #endif 137 if (config_cfattach_attach("md", &md_ca)) { 138 printf("md: cfattach_attach failed\n"); 139 return; 140 } 141 142 /* XXX: Are we supposed to provide a default? */ 143 if (n <= 1) 144 n = 1; 145 146 /* Attach as if by autoconfig. */ 147 for (i = 0; i < n; i++) { 148 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 149 cf->cf_name = "md"; 150 cf->cf_atname = "md"; 151 cf->cf_unit = i; 152 cf->cf_fstate = FSTATE_NOTFOUND; 153 (void)config_attach_pseudo(cf); 154 } 155 } 156 157 static void 158 md_attach(device_t parent, device_t self, void *aux) 159 { 160 struct md_softc *sc = device_private(self); 161 162 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 163 164 /* XXX - Could accept aux info here to set the config. */ 165 #ifdef MEMORY_DISK_HOOKS 166 /* 167 * This external function might setup a pre-loaded disk. 168 * All it would need to do is setup the md_conf struct. 169 * See sys/dev/md_root.c for an example. 170 */ 171 md_attach_hook(device_unit(self), &sc->sc_md); 172 #endif 173 174 /* 175 * Initialize and attach the disk structure. 176 */ 177 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 178 disk_attach(&sc->sc_dkdev); 179 180 if (!pmf_device_register(self, NULL, NULL)) 181 aprint_error_dev(self, "couldn't establish power handler\n"); 182 } 183 184 static int 185 md_detach(device_t self, int flags) 186 { 187 struct md_softc *sc = device_private(self); 188 int rc; 189 190 rc = 0; 191 mutex_enter(&sc->sc_dkdev.dk_openlock); 192 if (sc->sc_dkdev.dk_openmask == 0) 193 ; /* nothing to do */ 194 else if ((flags & DETACH_FORCE) == 0) 195 rc = EBUSY; 196 mutex_exit(&sc->sc_dkdev.dk_openlock); 197 198 if (rc != 0) 199 return rc; 200 201 pmf_device_deregister(self); 202 disk_detach(&sc->sc_dkdev); 203 disk_destroy(&sc->sc_dkdev); 204 bufq_free(sc->sc_buflist); 205 return 0; 206 } 207 208 /* 209 * operational routines: 210 * open, close, read, write, strategy, 211 * ioctl, dump, size 212 */ 213 214 #if MEMORY_DISK_SERVER 215 static int md_server_loop(struct md_softc *sc); 216 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 217 struct lwp *l); 218 #endif /* MEMORY_DISK_SERVER */ 219 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 220 struct lwp *l); 221 222 static int 223 mdsize(dev_t dev) 224 { 225 struct md_softc *sc; 226 227 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 228 if (sc == NULL) 229 return 0; 230 231 if (sc->sc_type == MD_UNCONFIGURED) 232 return 0; 233 234 return (sc->sc_size >> DEV_BSHIFT); 235 } 236 237 static int 238 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 239 { 240 int unit; 241 int part = DISKPART(dev); 242 int pmask = 1 << part; 243 struct md_softc *sc; 244 struct disk *dk; 245 246 unit = MD_UNIT(dev); 247 sc = device_lookup_private(&md_cd, unit); 248 if (sc == NULL) 249 return ENXIO; 250 251 dk = &sc->sc_dkdev; 252 253 /* 254 * The raw partition is used for ioctl to configure. 255 */ 256 if (part == RAW_PART) 257 goto ok; 258 259 #ifdef MEMORY_DISK_HOOKS 260 /* Call the open hook to allow loading the device. */ 261 md_open_hook(unit, &sc->sc_md); 262 #endif 263 264 /* 265 * This is a normal, "slave" device, so 266 * enforce initialized. 267 */ 268 if (sc->sc_type == MD_UNCONFIGURED) 269 return ENXIO; 270 271 ok: 272 /* XXX duplicates code in dk_open(). Call dk_open(), instead? */ 273 mutex_enter(&dk->dk_openlock); 274 /* Mark our unit as open. */ 275 switch (fmt) { 276 case S_IFCHR: 277 dk->dk_copenmask |= pmask; 278 break; 279 case S_IFBLK: 280 dk->dk_bopenmask |= pmask; 281 break; 282 } 283 284 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 285 286 mutex_exit(&dk->dk_openlock); 287 return 0; 288 } 289 290 static int 291 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 292 { 293 int part = DISKPART(dev); 294 int pmask = 1 << part; 295 struct md_softc *sc; 296 struct disk *dk; 297 298 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 299 if (sc == NULL) 300 return ENXIO; 301 302 dk = &sc->sc_dkdev; 303 304 mutex_enter(&dk->dk_openlock); 305 306 switch (fmt) { 307 case S_IFCHR: 308 dk->dk_copenmask &= ~pmask; 309 break; 310 case S_IFBLK: 311 dk->dk_bopenmask &= ~pmask; 312 break; 313 } 314 dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask; 315 316 mutex_exit(&dk->dk_openlock); 317 return 0; 318 } 319 320 static int 321 mdread(dev_t dev, struct uio *uio, int flags) 322 { 323 struct md_softc *sc; 324 325 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 326 327 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) 328 return ENXIO; 329 330 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 331 } 332 333 static int 334 mdwrite(dev_t dev, struct uio *uio, int flags) 335 { 336 struct md_softc *sc; 337 338 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 339 340 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) 341 return ENXIO; 342 343 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 344 } 345 346 /* 347 * Handle I/O requests, either directly, or 348 * by passing them to the server process. 349 */ 350 static void 351 mdstrategy(struct buf *bp) 352 { 353 struct md_softc *sc; 354 void * addr; 355 size_t off, xfer; 356 357 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 358 359 if (sc == NULL || sc->sc_type == MD_UNCONFIGURED) { 360 bp->b_error = ENXIO; 361 goto done; 362 } 363 364 switch (sc->sc_type) { 365 #if MEMORY_DISK_SERVER 366 case MD_UMEM_SERVER: 367 /* Just add this job to the server's queue. */ 368 bufq_put(sc->sc_buflist, bp); 369 wakeup((void *)sc); 370 /* see md_server_loop() */ 371 /* no biodone in this case */ 372 return; 373 #endif /* MEMORY_DISK_SERVER */ 374 375 case MD_KMEM_FIXED: 376 case MD_KMEM_ALLOCATED: 377 /* These are in kernel space. Access directly. */ 378 bp->b_resid = bp->b_bcount; 379 off = (bp->b_blkno << DEV_BSHIFT); 380 if (off >= sc->sc_size) { 381 if (bp->b_flags & B_READ) 382 break; /* EOF */ 383 goto set_eio; 384 } 385 xfer = bp->b_resid; 386 if (xfer > (sc->sc_size - off)) 387 xfer = (sc->sc_size - off); 388 addr = (char *)sc->sc_addr + off; 389 if (bp->b_flags & B_READ) 390 memcpy(bp->b_data, addr, xfer); 391 else 392 memcpy(addr, bp->b_data, xfer); 393 bp->b_resid -= xfer; 394 break; 395 396 default: 397 bp->b_resid = bp->b_bcount; 398 set_eio: 399 bp->b_error = EIO; 400 break; 401 } 402 done: 403 biodone(bp); 404 } 405 406 static int 407 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 408 { 409 struct md_softc *sc; 410 struct md_conf *umd; 411 412 if ((sc = device_lookup_private(&md_cd, MD_UNIT(dev))) == NULL) 413 return ENXIO; 414 415 /* If this is not the raw partition, punt! */ 416 if (DISKPART(dev) != RAW_PART) 417 return ENOTTY; 418 419 umd = (struct md_conf *)data; 420 switch (cmd) { 421 case MD_GETCONF: 422 *umd = sc->sc_md; 423 return 0; 424 425 case MD_SETCONF: 426 /* Can only set it once. */ 427 if (sc->sc_type != MD_UNCONFIGURED) 428 break; 429 switch (umd->md_type) { 430 case MD_KMEM_ALLOCATED: 431 return md_ioctl_kalloc(sc, umd, l); 432 #if MEMORY_DISK_SERVER 433 case MD_UMEM_SERVER: 434 return md_ioctl_server(sc, umd, l); 435 #endif /* MEMORY_DISK_SERVER */ 436 default: 437 break; 438 } 439 break; 440 } 441 return EINVAL; 442 } 443 444 /* 445 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 446 * Just allocate some kernel memory and return. 447 */ 448 static int 449 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 450 struct lwp *l) 451 { 452 vaddr_t addr; 453 vsize_t size; 454 455 /* Sanity check the size. */ 456 size = umd->md_size; 457 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 458 if (!addr) 459 return ENOMEM; 460 461 /* This unit is now configured. */ 462 sc->sc_addr = (void *)addr; /* kernel space */ 463 sc->sc_size = (size_t)size; 464 sc->sc_type = MD_KMEM_ALLOCATED; 465 return 0; 466 } 467 468 #if MEMORY_DISK_SERVER 469 470 /* 471 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 472 * Set config, then become the I/O server for this unit. 473 */ 474 static int 475 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 476 struct lwp *l) 477 { 478 vaddr_t end; 479 int error; 480 481 /* Sanity check addr, size. */ 482 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 483 484 if ((end >= VM_MAXUSER_ADDRESS) || 485 (end < ((vaddr_t) umd->md_addr)) ) 486 return EINVAL; 487 488 /* This unit is now configured. */ 489 sc->sc_addr = umd->md_addr; /* user space */ 490 sc->sc_size = umd->md_size; 491 sc->sc_type = MD_UMEM_SERVER; 492 493 /* Become the server daemon */ 494 error = md_server_loop(sc); 495 496 /* This server is now going away! */ 497 sc->sc_type = MD_UNCONFIGURED; 498 sc->sc_addr = 0; 499 sc->sc_size = 0; 500 501 return (error); 502 } 503 504 static int md_sleep_pri = PWAIT | PCATCH; 505 506 static int 507 md_server_loop(struct md_softc *sc) 508 { 509 struct buf *bp; 510 void *addr; /* user space address */ 511 size_t off; /* offset into "device" */ 512 size_t xfer; /* amount to transfer */ 513 int error; 514 515 for (;;) { 516 /* Wait for some work to arrive. */ 517 while ((bp = bufq_get(sc->sc_buflist)) == NULL) { 518 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 519 if (error) 520 return error; 521 } 522 523 /* Do the transfer to/from user space. */ 524 error = 0; 525 bp->b_resid = bp->b_bcount; 526 off = (bp->b_blkno << DEV_BSHIFT); 527 if (off >= sc->sc_size) { 528 if (bp->b_flags & B_READ) 529 goto done; /* EOF (not an error) */ 530 error = EIO; 531 goto done; 532 } 533 xfer = bp->b_resid; 534 if (xfer > (sc->sc_size - off)) 535 xfer = (sc->sc_size - off); 536 addr = (char *)sc->sc_addr + off; 537 if (bp->b_flags & B_READ) 538 error = copyin(addr, bp->b_data, xfer); 539 else 540 error = copyout(bp->b_data, addr, xfer); 541 if (!error) 542 bp->b_resid -= xfer; 543 544 done: 545 if (error) { 546 bp->b_error = error; 547 } 548 biodone(bp); 549 } 550 } 551 #endif /* MEMORY_DISK_SERVER */ 552
Indexes created Thu Sep 25 16:09:42 GMT 2025