md.c revision 1.34
1 /* $NetBSD: md.c,v 1.34 2003/05/13 02:56:13 thorpej 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 1.34 2003/05/13 02:56:13 thorpej 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, 198 struct md_conf *umd, struct proc *proc)); 199 200 int 201 mdsize(dev_t dev) 202 { 203 int unit; 204 struct md_softc *sc; 205 206 unit = MD_UNIT(dev); 207 if (unit >= ramdisk_ndevs) 208 return 0; 209 sc = ramdisk_devs[unit]; 210 if (sc == NULL) 211 return 0; 212 213 if (sc->sc_type == MD_UNCONFIGURED) 214 return 0; 215 216 return (sc->sc_size >> DEV_BSHIFT); 217 } 218 219 int 220 mdopen(dev, flag, fmt, proc) 221 dev_t dev; 222 int flag, fmt; 223 struct proc *proc; 224 { 225 int unit; 226 struct md_softc *sc; 227 228 unit = MD_UNIT(dev); 229 if (unit >= ramdisk_ndevs) 230 return ENXIO; 231 sc = ramdisk_devs[unit]; 232 if (sc == NULL) 233 return ENXIO; 234 235 /* 236 * The raw partition is used for ioctl to configure. 237 */ 238 if (DISKPART(dev) == RAW_PART) 239 return 0; 240 241 #ifdef MEMORY_DISK_HOOKS 242 /* Call the open hook to allow loading the device. */ 243 md_open_hook(unit, &sc->sc_md); 244 #endif 245 246 /* 247 * This is a normal, "slave" device, so 248 * enforce initialized. 249 */ 250 if (sc->sc_type == MD_UNCONFIGURED) 251 return ENXIO; 252 253 return 0; 254 } 255 256 int 257 mdclose(dev, flag, fmt, proc) 258 dev_t dev; 259 int flag, fmt; 260 struct proc *proc; 261 { 262 int unit; 263 264 unit = MD_UNIT(dev); 265 266 if (unit >= ramdisk_ndevs) 267 return ENXIO; 268 269 return 0; 270 } 271 272 int 273 mdread(dev, uio, flags) 274 dev_t dev; 275 struct uio *uio; 276 int flags; 277 { 278 int unit; 279 struct md_softc *sc; 280 281 unit = MD_UNIT(dev); 282 283 if (unit >= ramdisk_ndevs) 284 return ENXIO; 285 286 sc = ramdisk_devs[unit]; 287 288 if (sc->sc_type == MD_UNCONFIGURED) 289 return ENXIO; 290 291 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 292 } 293 294 int 295 mdwrite(dev, uio, flags) 296 dev_t dev; 297 struct uio *uio; 298 int flags; 299 { 300 int unit; 301 struct md_softc *sc; 302 303 unit = MD_UNIT(dev); 304 305 if (unit >= ramdisk_ndevs) 306 return ENXIO; 307 308 sc = ramdisk_devs[unit]; 309 310 if (sc->sc_type == MD_UNCONFIGURED) 311 return ENXIO; 312 313 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 314 } 315 316 /* 317 * Handle I/O requests, either directly, or 318 * by passing them to the server process. 319 */ 320 void 321 mdstrategy(bp) 322 struct buf *bp; 323 { 324 int unit; 325 struct md_softc *sc; 326 caddr_t addr; 327 size_t off, xfer; 328 329 unit = MD_UNIT(bp->b_dev); 330 sc = ramdisk_devs[unit]; 331 332 if (sc->sc_type == MD_UNCONFIGURED) { 333 bp->b_error = ENXIO; 334 bp->b_flags |= B_ERROR; 335 goto done; 336 } 337 338 switch (sc->sc_type) { 339 #if MEMORY_DISK_SERVER 340 case MD_UMEM_SERVER: 341 /* Just add this job to the server's queue. */ 342 BUFQ_PUT(&sc->sc_buflist, bp); 343 wakeup((caddr_t)sc); 344 /* see md_server_loop() */ 345 /* no biodone in this case */ 346 return; 347 #endif /* MEMORY_DISK_SERVER */ 348 349 case MD_KMEM_FIXED: 350 case MD_KMEM_ALLOCATED: 351 /* These are in kernel space. Access directly. */ 352 bp->b_resid = bp->b_bcount; 353 off = (bp->b_blkno << DEV_BSHIFT); 354 if (off >= sc->sc_size) { 355 if (bp->b_flags & B_READ) 356 break; /* EOF */ 357 goto set_eio; 358 } 359 xfer = bp->b_resid; 360 if (xfer > (sc->sc_size - off)) 361 xfer = (sc->sc_size - off); 362 addr = sc->sc_addr + off; 363 if (bp->b_flags & B_READ) 364 memcpy(bp->b_data, addr, xfer); 365 else 366 memcpy(addr, bp->b_data, xfer); 367 bp->b_resid -= xfer; 368 break; 369 370 default: 371 bp->b_resid = bp->b_bcount; 372 set_eio: 373 bp->b_error = EIO; 374 bp->b_flags |= B_ERROR; 375 break; 376 } 377 done: 378 biodone(bp); 379 } 380 381 int 382 mdioctl(dev, cmd, data, flag, proc) 383 dev_t dev; 384 u_long cmd; 385 int flag; 386 caddr_t data; 387 struct proc *proc; 388 { 389 int unit; 390 struct md_softc *sc; 391 struct md_conf *umd; 392 393 unit = MD_UNIT(dev); 394 sc = ramdisk_devs[unit]; 395 396 /* If this is not the raw partition, punt! */ 397 if (DISKPART(dev) != RAW_PART) 398 return ENOTTY; 399 400 umd = (struct md_conf *)data; 401 switch (cmd) { 402 case MD_GETCONF: 403 *umd = sc->sc_md; 404 return 0; 405 406 case MD_SETCONF: 407 /* Can only set it once. */ 408 if (sc->sc_type != MD_UNCONFIGURED) 409 break; 410 switch (umd->md_type) { 411 case MD_KMEM_ALLOCATED: 412 return md_ioctl_kalloc(sc, umd, proc); 413 #if MEMORY_DISK_SERVER 414 case MD_UMEM_SERVER: 415 return md_ioctl_server(sc, umd, proc); 416 #endif /* MEMORY_DISK_SERVER */ 417 default: 418 break; 419 } 420 break; 421 } 422 return EINVAL; 423 } 424 425 /* 426 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 427 * Just allocate some kernel memory and return. 428 */ 429 static int 430 md_ioctl_kalloc(sc, umd, proc) 431 struct md_softc *sc; 432 struct md_conf *umd; 433 struct proc *proc; 434 { 435 vaddr_t addr; 436 vsize_t size; 437 438 /* Sanity check the size. */ 439 size = umd->md_size; 440 addr = uvm_km_zalloc(kernel_map, size); 441 if (!addr) 442 return ENOMEM; 443 444 /* This unit is now configured. */ 445 sc->sc_addr = (caddr_t)addr; /* kernel space */ 446 sc->sc_size = (size_t)size; 447 sc->sc_type = MD_KMEM_ALLOCATED; 448 return 0; 449 } 450 451 #if MEMORY_DISK_SERVER 452 453 /* 454 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 455 * Set config, then become the I/O server for this unit. 456 */ 457 static int 458 md_ioctl_server(sc, umd, proc) 459 struct md_softc *sc; 460 struct md_conf *umd; 461 struct proc *proc; 462 { 463 vaddr_t end; 464 int error; 465 466 /* Sanity check addr, size. */ 467 end = (vaddr_t) (umd->md_addr + umd->md_size); 468 469 if ((end >= VM_MAXUSER_ADDRESS) || 470 (end < ((vaddr_t) umd->md_addr)) ) 471 return EINVAL; 472 473 /* This unit is now configured. */ 474 sc->sc_addr = umd->md_addr; /* user space */ 475 sc->sc_size = umd->md_size; 476 sc->sc_type = MD_UMEM_SERVER; 477 478 /* Become the server daemon */ 479 error = md_server_loop(sc); 480 481 /* This server is now going away! */ 482 sc->sc_type = MD_UNCONFIGURED; 483 sc->sc_addr = 0; 484 sc->sc_size = 0; 485 486 return (error); 487 } 488 489 int md_sleep_pri = PWAIT | PCATCH; 490 491 static int 492 md_server_loop(sc) 493 struct md_softc *sc; 494 { 495 struct buf *bp; 496 caddr_t addr; /* user space address */ 497 size_t off; /* offset into "device" */ 498 size_t xfer; /* amount to transfer */ 499 int error; 500 501 for (;;) { 502 /* Wait for some work to arrive. */ 503 while ((bp = BUFQ_GET(&sc->sc_buflist)) == NULL) { 504 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 505 if (error) 506 return error; 507 } 508 509 /* Do the transfer to/from user space. */ 510 error = 0; 511 bp->b_resid = bp->b_bcount; 512 off = (bp->b_blkno << DEV_BSHIFT); 513 if (off >= sc->sc_size) { 514 if (bp->b_flags & B_READ) 515 goto done; /* EOF (not an error) */ 516 error = EIO; 517 goto done; 518 } 519 xfer = bp->b_resid; 520 if (xfer > (sc->sc_size - off)) 521 xfer = (sc->sc_size - off); 522 addr = sc->sc_addr + off; 523 if (bp->b_flags & B_READ) 524 error = copyin(addr, bp->b_data, xfer); 525 else 526 error = copyout(bp->b_data, addr, xfer); 527 if (!error) 528 bp->b_resid -= xfer; 529 530 done: 531 if (error) { 532 bp->b_error = error; 533 bp->b_flags |= B_ERROR; 534 } 535 biodone(bp); 536 } 537 } 538 #endif /* MEMORY_DISK_SERVER */ 539
Indexes created Fri Sep 26 08:10:20 GMT 2025