md.c revision 1.36.2.1
1 /* $NetBSD: md.c,v 1.36.2.1 2003/07/02 15:26:00 darrenr 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 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 4. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by 20 * Gordon W. Ross and Leo Weppelman. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * This implements a general-purpose memory-disk. 36 * See md.h for notes on the config types. 37 * 38 * Note that this driver provides the same functionality 39 * as the MFS filesystem hack, but this is better because 40 * you can use this for any filesystem type you'd like! 41 * 42 * Credit for most of the kmem ramdisk code goes to: 43 * Leo Weppelman (atari) and Phil Nelson (pc532) 44 * Credit for the ideas behind the "user space memory" code goes 45 * to the authors of the MFS implementation. 46 */ 47 48 #include <sys/cdefs.h> 49 __KERNEL_RCSID(0, "$NetBSD: md.c,v 1.36.2.1 2003/07/02 15:26:00 darrenr Exp $"); 50 51 #include "opt_md.h" 52 53 #include <sys/param.h> 54 #include <sys/kernel.h> 55 #include <sys/malloc.h> 56 #include <sys/systm.h> 57 #include <sys/buf.h> 58 #include <sys/device.h> 59 #include <sys/disk.h> 60 #include <sys/proc.h> 61 #include <sys/conf.h> 62 #include <sys/disklabel.h> 63 64 #include <uvm/uvm_extern.h> 65 66 #include <dev/md.h> 67 68 /* 69 * By default, include the user-space functionality. 70 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 71 */ 72 #ifndef MEMORY_DISK_SERVER 73 #define MEMORY_DISK_SERVER 1 74 #endif /* MEMORY_DISK_SERVER */ 75 76 /* 77 * We should use the raw partition for ioctl. 78 */ 79 #define MD_MAX_UNITS 0x10 80 #define MD_UNIT(unit) DISKUNIT(unit) 81 82 /* autoconfig stuff... */ 83 84 struct md_softc { 85 struct device sc_dev; /* REQUIRED first entry */ 86 struct disk sc_dkdev; /* hook for generic disk handling */ 87 struct md_conf sc_md; 88 struct bufq_state sc_buflist; 89 }; 90 /* shorthand for fields in sc_md: */ 91 #define sc_addr sc_md.md_addr 92 #define sc_size sc_md.md_size 93 #define sc_type sc_md.md_type 94 95 void mdattach __P((int)); 96 static void md_attach __P((struct device *, struct device *, void *)); 97 98 dev_type_open(mdopen); 99 dev_type_close(mdclose); 100 dev_type_read(mdread); 101 dev_type_write(mdwrite); 102 dev_type_ioctl(mdioctl); 103 dev_type_strategy(mdstrategy); 104 dev_type_size(mdsize); 105 106 const struct bdevsw md_bdevsw = { 107 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK 108 }; 109 110 const struct cdevsw md_cdevsw = { 111 mdopen, mdclose, mdread, mdwrite, mdioctl, 112 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 113 }; 114 115 struct dkdriver mddkdriver = { mdstrategy }; 116 117 static int ramdisk_ndevs; 118 static void *ramdisk_devs[MD_MAX_UNITS]; 119 120 /* 121 * This is called if we are configured as a pseudo-device 122 */ 123 void 124 mdattach(n) 125 int n; 126 { 127 struct md_softc *sc; 128 int i; 129 130 #ifdef DIAGNOSTIC 131 if (ramdisk_ndevs) { 132 aprint_error("ramdisk: multiple attach calls?\n"); 133 return; 134 } 135 #endif 136 137 /* XXX: Are we supposed to provide a default? */ 138 if (n <= 1) 139 n = 1; 140 if (n > MD_MAX_UNITS) 141 n = MD_MAX_UNITS; 142 ramdisk_ndevs = n; 143 144 /* Attach as if by autoconfig. */ 145 for (i = 0; i < n; i++) { 146 147 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO); 148 if (!sc) { 149 aprint_error("ramdisk: malloc for attach failed!\n"); 150 return; 151 } 152 ramdisk_devs[i] = sc; 153 sc->sc_dev.dv_unit = i; 154 sprintf(sc->sc_dev.dv_xname, "md%d", i); 155 md_attach(NULL, &sc->sc_dev, NULL); 156 } 157 } 158 159 static void 160 md_attach(parent, self, aux) 161 struct device *parent, *self; 162 void *aux; 163 { 164 struct md_softc *sc = (struct md_softc *)self; 165 166 bufq_alloc(&sc->sc_buflist, BUFQ_FCFS); 167 168 /* XXX - Could accept aux info here to set the config. */ 169 #ifdef MEMORY_DISK_HOOKS 170 /* 171 * This external function might setup a pre-loaded disk. 172 * All it would need to do is setup the md_conf struct. 173 * See sys/dev/md_root.c for an example. 174 */ 175 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 176 #endif 177 178 /* 179 * Initialize and attach the disk structure. 180 */ 181 sc->sc_dkdev.dk_driver = &mddkdriver; 182 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 183 disk_attach(&sc->sc_dkdev); 184 } 185 186 /* 187 * operational routines: 188 * open, close, read, write, strategy, 189 * ioctl, dump, size 190 */ 191 192 #if MEMORY_DISK_SERVER 193 static int md_server_loop __P((struct md_softc *sc)); 194 static int md_ioctl_server __P((struct md_softc *sc, 195 struct md_conf *umd, struct proc *proc)); 196 #endif /* MEMORY_DISK_SERVER */ 197 static int md_ioctl_kalloc __P((struct md_softc *sc, struct md_conf *umd)); 198 199 int 200 mdsize(dev_t dev) 201 { 202 int unit; 203 struct md_softc *sc; 204 205 unit = MD_UNIT(dev); 206 if (unit >= ramdisk_ndevs) 207 return 0; 208 sc = ramdisk_devs[unit]; 209 if (sc == NULL) 210 return 0; 211 212 if (sc->sc_type == MD_UNCONFIGURED) 213 return 0; 214 215 return (sc->sc_size >> DEV_BSHIFT); 216 } 217 218 int 219 mdopen(dev, flag, fmt, l) 220 dev_t dev; 221 int flag, fmt; 222 struct lwp *l; 223 { 224 int unit; 225 struct md_softc *sc; 226 227 unit = MD_UNIT(dev); 228 if (unit >= ramdisk_ndevs) 229 return ENXIO; 230 sc = ramdisk_devs[unit]; 231 if (sc == NULL) 232 return ENXIO; 233 234 /* 235 * The raw partition is used for ioctl to configure. 236 */ 237 if (DISKPART(dev) == RAW_PART) 238 return 0; 239 240 #ifdef MEMORY_DISK_HOOKS 241 /* Call the open hook to allow loading the device. */ 242 md_open_hook(unit, &sc->sc_md); 243 #endif 244 245 /* 246 * This is a normal, "slave" device, so 247 * enforce initialized. 248 */ 249 if (sc->sc_type == MD_UNCONFIGURED) 250 return ENXIO; 251 252 return 0; 253 } 254 255 int 256 mdclose(dev, flag, fmt, l) 257 dev_t dev; 258 int flag, fmt; 259 struct lwp *l; 260 { 261 int unit; 262 263 unit = MD_UNIT(dev); 264 265 if (unit >= ramdisk_ndevs) 266 return ENXIO; 267 268 return 0; 269 } 270 271 int 272 mdread(dev, uio, flags) 273 dev_t dev; 274 struct uio *uio; 275 int flags; 276 { 277 int unit; 278 struct md_softc *sc; 279 280 unit = MD_UNIT(dev); 281 282 if (unit >= ramdisk_ndevs) 283 return ENXIO; 284 285 sc = ramdisk_devs[unit]; 286 287 if (sc->sc_type == MD_UNCONFIGURED) 288 return ENXIO; 289 290 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 291 } 292 293 int 294 mdwrite(dev, uio, flags) 295 dev_t dev; 296 struct uio *uio; 297 int flags; 298 { 299 int unit; 300 struct md_softc *sc; 301 302 unit = MD_UNIT(dev); 303 304 if (unit >= ramdisk_ndevs) 305 return ENXIO; 306 307 sc = ramdisk_devs[unit]; 308 309 if (sc->sc_type == MD_UNCONFIGURED) 310 return ENXIO; 311 312 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 313 } 314 315 /* 316 * Handle I/O requests, either directly, or 317 * by passing them to the server process. 318 */ 319 void 320 mdstrategy(bp) 321 struct buf *bp; 322 { 323 int unit; 324 struct md_softc *sc; 325 caddr_t addr; 326 size_t off, xfer; 327 328 unit = MD_UNIT(bp->b_dev); 329 sc = ramdisk_devs[unit]; 330 331 if (sc->sc_type == MD_UNCONFIGURED) { 332 bp->b_error = ENXIO; 333 bp->b_flags |= B_ERROR; 334 goto done; 335 } 336 337 switch (sc->sc_type) { 338 #if MEMORY_DISK_SERVER 339 case MD_UMEM_SERVER: 340 /* Just add this job to the server's queue. */ 341 BUFQ_PUT(&sc->sc_buflist, bp); 342 wakeup((caddr_t)sc); 343 /* see md_server_loop() */ 344 /* no biodone in this case */ 345 return; 346 #endif /* MEMORY_DISK_SERVER */ 347 348 case MD_KMEM_FIXED: 349 case MD_KMEM_ALLOCATED: 350 /* These are in kernel space. Access directly. */ 351 bp->b_resid = bp->b_bcount; 352 off = (bp->b_blkno << DEV_BSHIFT); 353 if (off >= sc->sc_size) { 354 if (bp->b_flags & B_READ) 355 break; /* EOF */ 356 goto set_eio; 357 } 358 xfer = bp->b_resid; 359 if (xfer > (sc->sc_size - off)) 360 xfer = (sc->sc_size - off); 361 addr = sc->sc_addr + off; 362 if (bp->b_flags & B_READ) 363 memcpy(bp->b_data, addr, xfer); 364 else 365 memcpy(addr, bp->b_data, xfer); 366 bp->b_resid -= xfer; 367 break; 368 369 default: 370 bp->b_resid = bp->b_bcount; 371 set_eio: 372 bp->b_error = EIO; 373 bp->b_flags |= B_ERROR; 374 break; 375 } 376 done: 377 biodone(bp); 378 } 379 380 int 381 mdioctl(dev, cmd, data, flag, l) 382 dev_t dev; 383 u_long cmd; 384 int flag; 385 caddr_t data; 386 struct lwp *l; 387 { 388 int unit; 389 struct md_softc *sc; 390 struct md_conf *umd; 391 392 unit = MD_UNIT(dev); 393 sc = ramdisk_devs[unit]; 394 395 /* If this is not the raw partition, punt! */ 396 if (DISKPART(dev) != RAW_PART) 397 return ENOTTY; 398 399 umd = (struct md_conf *)data; 400 switch (cmd) { 401 case MD_GETCONF: 402 *umd = sc->sc_md; 403 return 0; 404 405 case MD_SETCONF: 406 /* Can only set it once. */ 407 if (sc->sc_type != MD_UNCONFIGURED) 408 break; 409 switch (umd->md_type) { 410 case MD_KMEM_ALLOCATED: 411 return md_ioctl_kalloc(sc, umd); 412 #if MEMORY_DISK_SERVER 413 case MD_UMEM_SERVER: 414 return md_ioctl_server(sc, umd, l->l_proc); 415 #endif /* MEMORY_DISK_SERVER */ 416 default: 417 break; 418 } 419 break; 420 } 421 return EINVAL; 422 } 423 424 /* 425 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 426 * Just allocate some kernel memory and return. 427 */ 428 static int 429 md_ioctl_kalloc(sc, umd) 430 struct md_softc *sc; 431 struct md_conf *umd; 432 { 433 vaddr_t addr; 434 vsize_t size; 435 436 /* Sanity check the size. */ 437 size = umd->md_size; 438 addr = uvm_km_zalloc(kernel_map, size); 439 if (!addr) 440 return ENOMEM; 441 442 /* This unit is now configured. */ 443 sc->sc_addr = (caddr_t)addr; /* kernel space */ 444 sc->sc_size = (size_t)size; 445 sc->sc_type = MD_KMEM_ALLOCATED; 446 return 0; 447 } 448 449 #if MEMORY_DISK_SERVER 450 451 /* 452 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 453 * Set config, then become the I/O server for this unit. 454 */ 455 static int 456 md_ioctl_server(sc, umd, proc) 457 struct md_softc *sc; 458 struct md_conf *umd; 459 struct proc *proc; 460 { 461 vaddr_t end; 462 int error; 463 464 /* Sanity check addr, size. */ 465 end = (vaddr_t) (umd->md_addr + umd->md_size); 466 467 if ((end >= VM_MAXUSER_ADDRESS) || 468 (end < ((vaddr_t) umd->md_addr)) ) 469 return EINVAL; 470 471 /* This unit is now configured. */ 472 sc->sc_addr = umd->md_addr; /* user space */ 473 sc->sc_size = umd->md_size; 474 sc->sc_type = MD_UMEM_SERVER; 475 476 /* Become the server daemon */ 477 error = md_server_loop(sc); 478 479 /* This server is now going away! */ 480 sc->sc_type = MD_UNCONFIGURED; 481 sc->sc_addr = 0; 482 sc->sc_size = 0; 483 484 return (error); 485 } 486 487 int md_sleep_pri = PWAIT | PCATCH; 488 489 static int 490 md_server_loop(sc) 491 struct md_softc *sc; 492 { 493 struct buf *bp; 494 caddr_t addr; /* user space address */ 495 size_t off; /* offset into "device" */ 496 size_t xfer; /* amount to transfer */ 497 int error; 498 499 for (;;) { 500 /* Wait for some work to arrive. */ 501 while ((bp = BUFQ_GET(&sc->sc_buflist)) == NULL) { 502 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 503 if (error) 504 return error; 505 } 506 507 /* Do the transfer to/from user space. */ 508 error = 0; 509 bp->b_resid = bp->b_bcount; 510 off = (bp->b_blkno << DEV_BSHIFT); 511 if (off >= sc->sc_size) { 512 if (bp->b_flags & B_READ) 513 goto done; /* EOF (not an error) */ 514 error = EIO; 515 goto done; 516 } 517 xfer = bp->b_resid; 518 if (xfer > (sc->sc_size - off)) 519 xfer = (sc->sc_size - off); 520 addr = sc->sc_addr + off; 521 if (bp->b_flags & B_READ) 522 error = copyin(addr, bp->b_data, xfer); 523 else 524 error = copyout(bp->b_data, addr, xfer); 525 if (!error) 526 bp->b_resid -= xfer; 527 528 done: 529 if (error) { 530 bp->b_error = error; 531 bp->b_flags |= B_ERROR; 532 } 533 biodone(bp); 534 } 535 } 536 #endif /* MEMORY_DISK_SERVER */ 537
Indexes created Tue Sep 30 20:09:53 GMT 2025