md.c revision 1.26
1 /* $NetBSD: md.c,v 1.26 2001/07/07 17:04:02 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 "opt_md.h" 49 50 #include <sys/param.h> 51 #include <sys/kernel.h> 52 #include <sys/malloc.h> 53 #include <sys/systm.h> 54 #include <sys/buf.h> 55 #include <sys/device.h> 56 #include <sys/disk.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 * By default, include the user-space functionality. 67 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 68 */ 69 #ifndef MEMORY_DISK_SERVER 70 #define MEMORY_DISK_SERVER 1 71 #endif 72 73 /* 74 * We should use the raw partition for ioctl. 75 */ 76 #define MD_MAX_UNITS 0x10 77 #define MD_UNIT(unit) DISKUNIT(unit) 78 79 /* autoconfig stuff... */ 80 81 struct md_softc { 82 struct device sc_dev; /* REQUIRED first entry */ 83 struct disk sc_dkdev; /* hook for generic disk handling */ 84 struct md_conf sc_md; 85 struct buf_queue sc_buflist; 86 }; 87 /* shorthand for fields in sc_md: */ 88 #define sc_addr sc_md.md_addr 89 #define sc_size sc_md.md_size 90 #define sc_type sc_md.md_type 91 92 void mdattach __P((int)); 93 static void md_attach __P((struct device *, struct device *, void *)); 94 95 void mdstrategy __P((struct buf *bp)); 96 struct dkdriver mddkdriver = { mdstrategy }; 97 98 static int ramdisk_ndevs; 99 static void *ramdisk_devs[MD_MAX_UNITS]; 100 101 /* 102 * This is called if we are configured as a pseudo-device 103 */ 104 void 105 mdattach(n) 106 int n; 107 { 108 struct md_softc *sc; 109 int i; 110 111 #ifdef DIAGNOSTIC 112 if (ramdisk_ndevs) { 113 printf("ramdisk: multiple attach calls?\n"); 114 return; 115 } 116 #endif 117 118 /* XXX: Are we supposed to provide a default? */ 119 if (n <= 1) 120 n = 1; 121 if (n > MD_MAX_UNITS) 122 n = MD_MAX_UNITS; 123 ramdisk_ndevs = n; 124 125 /* Attach as if by autoconfig. */ 126 for (i = 0; i < n; i++) { 127 128 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT); 129 if (!sc) { 130 printf("ramdisk: malloc for attach failed!\n"); 131 return; 132 } 133 memset((caddr_t)sc, 0, sizeof(*sc)); 134 ramdisk_devs[i] = sc; 135 sc->sc_dev.dv_unit = i; 136 sprintf(sc->sc_dev.dv_xname, "md%d", i); 137 md_attach(NULL, &sc->sc_dev, NULL); 138 } 139 } 140 141 static void 142 md_attach(parent, self, aux) 143 struct device *parent, *self; 144 void *aux; 145 { 146 struct md_softc *sc = (struct md_softc *)self; 147 148 BUFQ_INIT(&sc->sc_buflist); 149 150 /* XXX - Could accept aux info here to set the config. */ 151 #ifdef MEMORY_DISK_HOOKS 152 /* 153 * This external function might setup a pre-loaded disk. 154 * All it would need to do is setup the md_conf struct. 155 * See sys/dev/md_root.c for an example. 156 */ 157 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 158 #endif 159 160 /* 161 * Initialize and attach the disk structure. 162 */ 163 sc->sc_dkdev.dk_driver = &mddkdriver; 164 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 165 disk_attach(&sc->sc_dkdev); 166 } 167 168 /* 169 * operational routines: 170 * open, close, read, write, strategy, 171 * ioctl, dump, size 172 */ 173 174 #if MEMORY_DISK_SERVER 175 static int md_server_loop __P((struct md_softc *sc)); 176 static int md_ioctl_server __P((struct md_softc *sc, 177 struct md_conf *umd, struct proc *proc)); 178 #endif 179 static int md_ioctl_kalloc __P((struct md_softc *sc, 180 struct md_conf *umd, struct proc *proc)); 181 182 dev_type_open(mdopen); 183 dev_type_close(mdclose); 184 dev_type_read(mdread); 185 dev_type_write(mdwrite); 186 dev_type_ioctl(mdioctl); 187 dev_type_size(mdsize); 188 dev_type_dump(mddump); 189 190 int 191 mddump(dev, blkno, va, size) 192 dev_t dev; 193 daddr_t blkno; 194 caddr_t va; 195 size_t size; 196 { 197 return ENODEV; 198 } 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_INSERT_TAIL(&sc->sc_buflist, bp); 343 if (BUFQ_FIRST(&sc->sc_buflist) == bp) { 344 /* server queue was empty. */ 345 wakeup((caddr_t)sc); 346 /* see md_server_loop() */ 347 } 348 /* no biodone in this case */ 349 return; 350 #endif /* MEMORY_DISK_SERVER */ 351 352 case MD_KMEM_FIXED: 353 case MD_KMEM_ALLOCATED: 354 /* These are in kernel space. Access directly. */ 355 bp->b_resid = bp->b_bcount; 356 off = (bp->b_blkno << DEV_BSHIFT); 357 if (off >= sc->sc_size) { 358 if (bp->b_flags & B_READ) 359 break; /* EOF */ 360 goto set_eio; 361 } 362 xfer = bp->b_resid; 363 if (xfer > (sc->sc_size - off)) 364 xfer = (sc->sc_size - off); 365 addr = sc->sc_addr + off; 366 if (bp->b_flags & B_READ) 367 memcpy(bp->b_data, addr, xfer); 368 else 369 memcpy(addr, bp->b_data, xfer); 370 bp->b_resid -= xfer; 371 break; 372 373 default: 374 bp->b_resid = bp->b_bcount; 375 set_eio: 376 bp->b_error = EIO; 377 bp->b_flags |= B_ERROR; 378 break; 379 } 380 done: 381 biodone(bp); 382 } 383 384 int 385 mdioctl(dev, cmd, data, flag, proc) 386 dev_t dev; 387 u_long cmd; 388 int flag; 389 caddr_t data; 390 struct proc *proc; 391 { 392 int unit; 393 struct md_softc *sc; 394 struct md_conf *umd; 395 396 unit = MD_UNIT(dev); 397 sc = ramdisk_devs[unit]; 398 399 /* If this is not the raw partition, punt! */ 400 if (DISKPART(dev) != RAW_PART) 401 return ENOTTY; 402 403 umd = (struct md_conf *)data; 404 switch (cmd) { 405 case MD_GETCONF: 406 *umd = sc->sc_md; 407 return 0; 408 409 case MD_SETCONF: 410 /* Can only set it once. */ 411 if (sc->sc_type != MD_UNCONFIGURED) 412 break; 413 switch (umd->md_type) { 414 case MD_KMEM_ALLOCATED: 415 return md_ioctl_kalloc(sc, umd, proc); 416 #if MEMORY_DISK_SERVER 417 case MD_UMEM_SERVER: 418 return md_ioctl_server(sc, umd, proc); 419 #endif 420 default: 421 break; 422 } 423 break; 424 } 425 return EINVAL; 426 } 427 428 /* 429 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 430 * Just allocate some kernel memory and return. 431 */ 432 static int 433 md_ioctl_kalloc(sc, umd, proc) 434 struct md_softc *sc; 435 struct md_conf *umd; 436 struct proc *proc; 437 { 438 vaddr_t addr; 439 vsize_t size; 440 441 /* Sanity check the size. */ 442 size = umd->md_size; 443 addr = uvm_km_zalloc(kernel_map, size); 444 if (!addr) 445 return ENOMEM; 446 447 /* This unit is now configured. */ 448 sc->sc_addr = (caddr_t)addr; /* kernel space */ 449 sc->sc_size = (size_t)size; 450 sc->sc_type = MD_KMEM_ALLOCATED; 451 return 0; 452 } 453 454 #if MEMORY_DISK_SERVER 455 456 /* 457 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 458 * Set config, then become the I/O server for this unit. 459 */ 460 static int 461 md_ioctl_server(sc, umd, proc) 462 struct md_softc *sc; 463 struct md_conf *umd; 464 struct proc *proc; 465 { 466 vaddr_t end; 467 int error; 468 469 /* Sanity check addr, size. */ 470 end = (vaddr_t) (umd->md_addr + umd->md_size); 471 472 if ((end >= VM_MAXUSER_ADDRESS) || 473 (end < ((vaddr_t) umd->md_addr)) ) 474 return EINVAL; 475 476 /* This unit is now configured. */ 477 sc->sc_addr = umd->md_addr; /* user space */ 478 sc->sc_size = umd->md_size; 479 sc->sc_type = MD_UMEM_SERVER; 480 481 /* Become the server daemon */ 482 error = md_server_loop(sc); 483 484 /* This server is now going away! */ 485 sc->sc_type = MD_UNCONFIGURED; 486 sc->sc_addr = 0; 487 sc->sc_size = 0; 488 489 return (error); 490 } 491 492 int md_sleep_pri = PWAIT | PCATCH; 493 494 static int 495 md_server_loop(sc) 496 struct md_softc *sc; 497 { 498 struct buf *bp; 499 caddr_t addr; /* user space address */ 500 size_t off; /* offset into "device" */ 501 size_t xfer; /* amount to transfer */ 502 int error; 503 504 for (;;) { 505 /* Wait for some work to arrive. */ 506 while ((bp = BUFQ_FIRST(&sc->sc_buflist)) == NULL) { 507 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 508 if (error) 509 return error; 510 } 511 512 /* Unlink buf from head of list. */ 513 BUFQ_REMOVE(&sc->sc_buflist, bp); 514 515 /* Do the transfer to/from user space. */ 516 error = 0; 517 bp->b_resid = bp->b_bcount; 518 off = (bp->b_blkno << DEV_BSHIFT); 519 if (off >= sc->sc_size) { 520 if (bp->b_flags & B_READ) 521 goto done; /* EOF (not an error) */ 522 error = EIO; 523 goto done; 524 } 525 xfer = bp->b_resid; 526 if (xfer > (sc->sc_size - off)) 527 xfer = (sc->sc_size - off); 528 addr = sc->sc_addr + off; 529 if (bp->b_flags & B_READ) 530 error = copyin(addr, bp->b_data, xfer); 531 else 532 error = copyout(bp->b_data, addr, xfer); 533 if (!error) 534 bp->b_resid -= xfer; 535 536 done: 537 if (error) { 538 bp->b_error = error; 539 bp->b_flags |= B_ERROR; 540 } 541 biodone(bp); 542 } 543 } 544 #endif /* MEMORY_DISK_SERVER */ 545
Indexes created Thu Sep 25 16:09:42 GMT 2025