md.c revision 1.27
1 /* $NetBSD: md.c,v 1.27 2001/11/13 05:32:50 lukem 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 1.27 2001/11/13 05:32:50 lukem 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 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 buf_queue 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 void mdstrategy __P((struct buf *bp)); 99 struct dkdriver mddkdriver = { mdstrategy }; 100 101 static int ramdisk_ndevs; 102 static void *ramdisk_devs[MD_MAX_UNITS]; 103 104 /* 105 * This is called if we are configured as a pseudo-device 106 */ 107 void 108 mdattach(n) 109 int n; 110 { 111 struct md_softc *sc; 112 int i; 113 114 #ifdef DIAGNOSTIC 115 if (ramdisk_ndevs) { 116 printf("ramdisk: multiple attach calls?\n"); 117 return; 118 } 119 #endif 120 121 /* XXX: Are we supposed to provide a default? */ 122 if (n <= 1) 123 n = 1; 124 if (n > MD_MAX_UNITS) 125 n = MD_MAX_UNITS; 126 ramdisk_ndevs = n; 127 128 /* Attach as if by autoconfig. */ 129 for (i = 0; i < n; i++) { 130 131 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT); 132 if (!sc) { 133 printf("ramdisk: malloc for attach failed!\n"); 134 return; 135 } 136 memset((caddr_t)sc, 0, sizeof(*sc)); 137 ramdisk_devs[i] = sc; 138 sc->sc_dev.dv_unit = i; 139 sprintf(sc->sc_dev.dv_xname, "md%d", i); 140 md_attach(NULL, &sc->sc_dev, NULL); 141 } 142 } 143 144 static void 145 md_attach(parent, self, aux) 146 struct device *parent, *self; 147 void *aux; 148 { 149 struct md_softc *sc = (struct md_softc *)self; 150 151 BUFQ_INIT(&sc->sc_buflist); 152 153 /* XXX - Could accept aux info here to set the config. */ 154 #ifdef MEMORY_DISK_HOOKS 155 /* 156 * This external function might setup a pre-loaded disk. 157 * All it would need to do is setup the md_conf struct. 158 * See sys/dev/md_root.c for an example. 159 */ 160 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 161 #endif 162 163 /* 164 * Initialize and attach the disk structure. 165 */ 166 sc->sc_dkdev.dk_driver = &mddkdriver; 167 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 168 disk_attach(&sc->sc_dkdev); 169 } 170 171 /* 172 * operational routines: 173 * open, close, read, write, strategy, 174 * ioctl, dump, size 175 */ 176 177 #if MEMORY_DISK_SERVER 178 static int md_server_loop __P((struct md_softc *sc)); 179 static int md_ioctl_server __P((struct md_softc *sc, 180 struct md_conf *umd, struct proc *proc)); 181 #endif 182 static int md_ioctl_kalloc __P((struct md_softc *sc, 183 struct md_conf *umd, struct proc *proc)); 184 185 dev_type_open(mdopen); 186 dev_type_close(mdclose); 187 dev_type_read(mdread); 188 dev_type_write(mdwrite); 189 dev_type_ioctl(mdioctl); 190 dev_type_size(mdsize); 191 dev_type_dump(mddump); 192 193 int 194 mddump(dev, blkno, va, size) 195 dev_t dev; 196 daddr_t blkno; 197 caddr_t va; 198 size_t size; 199 { 200 return ENODEV; 201 } 202 203 int 204 mdsize(dev_t dev) 205 { 206 int unit; 207 struct md_softc *sc; 208 209 unit = MD_UNIT(dev); 210 if (unit >= ramdisk_ndevs) 211 return 0; 212 sc = ramdisk_devs[unit]; 213 if (sc == NULL) 214 return 0; 215 216 if (sc->sc_type == MD_UNCONFIGURED) 217 return 0; 218 219 return (sc->sc_size >> DEV_BSHIFT); 220 } 221 222 int 223 mdopen(dev, flag, fmt, proc) 224 dev_t dev; 225 int flag, fmt; 226 struct proc *proc; 227 { 228 int unit; 229 struct md_softc *sc; 230 231 unit = MD_UNIT(dev); 232 if (unit >= ramdisk_ndevs) 233 return ENXIO; 234 sc = ramdisk_devs[unit]; 235 if (sc == NULL) 236 return ENXIO; 237 238 /* 239 * The raw partition is used for ioctl to configure. 240 */ 241 if (DISKPART(dev) == RAW_PART) 242 return 0; 243 244 #ifdef MEMORY_DISK_HOOKS 245 /* Call the open hook to allow loading the device. */ 246 md_open_hook(unit, &sc->sc_md); 247 #endif 248 249 /* 250 * This is a normal, "slave" device, so 251 * enforce initialized. 252 */ 253 if (sc->sc_type == MD_UNCONFIGURED) 254 return ENXIO; 255 256 return 0; 257 } 258 259 int 260 mdclose(dev, flag, fmt, proc) 261 dev_t dev; 262 int flag, fmt; 263 struct proc *proc; 264 { 265 int unit; 266 267 unit = MD_UNIT(dev); 268 269 if (unit >= ramdisk_ndevs) 270 return ENXIO; 271 272 return 0; 273 } 274 275 int 276 mdread(dev, uio, flags) 277 dev_t dev; 278 struct uio *uio; 279 int flags; 280 { 281 int unit; 282 struct md_softc *sc; 283 284 unit = MD_UNIT(dev); 285 286 if (unit >= ramdisk_ndevs) 287 return ENXIO; 288 289 sc = ramdisk_devs[unit]; 290 291 if (sc->sc_type == MD_UNCONFIGURED) 292 return ENXIO; 293 294 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 295 } 296 297 int 298 mdwrite(dev, uio, flags) 299 dev_t dev; 300 struct uio *uio; 301 int flags; 302 { 303 int unit; 304 struct md_softc *sc; 305 306 unit = MD_UNIT(dev); 307 308 if (unit >= ramdisk_ndevs) 309 return ENXIO; 310 311 sc = ramdisk_devs[unit]; 312 313 if (sc->sc_type == MD_UNCONFIGURED) 314 return ENXIO; 315 316 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 317 } 318 319 /* 320 * Handle I/O requests, either directly, or 321 * by passing them to the server process. 322 */ 323 void 324 mdstrategy(bp) 325 struct buf *bp; 326 { 327 int unit; 328 struct md_softc *sc; 329 caddr_t addr; 330 size_t off, xfer; 331 332 unit = MD_UNIT(bp->b_dev); 333 sc = ramdisk_devs[unit]; 334 335 if (sc->sc_type == MD_UNCONFIGURED) { 336 bp->b_error = ENXIO; 337 bp->b_flags |= B_ERROR; 338 goto done; 339 } 340 341 switch (sc->sc_type) { 342 #if MEMORY_DISK_SERVER 343 case MD_UMEM_SERVER: 344 /* Just add this job to the server's queue. */ 345 BUFQ_INSERT_TAIL(&sc->sc_buflist, bp); 346 if (BUFQ_FIRST(&sc->sc_buflist) == bp) { 347 /* server queue was empty. */ 348 wakeup((caddr_t)sc); 349 /* see md_server_loop() */ 350 } 351 /* no biodone in this case */ 352 return; 353 #endif /* MEMORY_DISK_SERVER */ 354 355 case MD_KMEM_FIXED: 356 case MD_KMEM_ALLOCATED: 357 /* These are in kernel space. Access directly. */ 358 bp->b_resid = bp->b_bcount; 359 off = (bp->b_blkno << DEV_BSHIFT); 360 if (off >= sc->sc_size) { 361 if (bp->b_flags & B_READ) 362 break; /* EOF */ 363 goto set_eio; 364 } 365 xfer = bp->b_resid; 366 if (xfer > (sc->sc_size - off)) 367 xfer = (sc->sc_size - off); 368 addr = sc->sc_addr + off; 369 if (bp->b_flags & B_READ) 370 memcpy(bp->b_data, addr, xfer); 371 else 372 memcpy(addr, bp->b_data, xfer); 373 bp->b_resid -= xfer; 374 break; 375 376 default: 377 bp->b_resid = bp->b_bcount; 378 set_eio: 379 bp->b_error = EIO; 380 bp->b_flags |= B_ERROR; 381 break; 382 } 383 done: 384 biodone(bp); 385 } 386 387 int 388 mdioctl(dev, cmd, data, flag, proc) 389 dev_t dev; 390 u_long cmd; 391 int flag; 392 caddr_t data; 393 struct proc *proc; 394 { 395 int unit; 396 struct md_softc *sc; 397 struct md_conf *umd; 398 399 unit = MD_UNIT(dev); 400 sc = ramdisk_devs[unit]; 401 402 /* If this is not the raw partition, punt! */ 403 if (DISKPART(dev) != RAW_PART) 404 return ENOTTY; 405 406 umd = (struct md_conf *)data; 407 switch (cmd) { 408 case MD_GETCONF: 409 *umd = sc->sc_md; 410 return 0; 411 412 case MD_SETCONF: 413 /* Can only set it once. */ 414 if (sc->sc_type != MD_UNCONFIGURED) 415 break; 416 switch (umd->md_type) { 417 case MD_KMEM_ALLOCATED: 418 return md_ioctl_kalloc(sc, umd, proc); 419 #if MEMORY_DISK_SERVER 420 case MD_UMEM_SERVER: 421 return md_ioctl_server(sc, umd, proc); 422 #endif 423 default: 424 break; 425 } 426 break; 427 } 428 return EINVAL; 429 } 430 431 /* 432 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 433 * Just allocate some kernel memory and return. 434 */ 435 static int 436 md_ioctl_kalloc(sc, umd, proc) 437 struct md_softc *sc; 438 struct md_conf *umd; 439 struct proc *proc; 440 { 441 vaddr_t addr; 442 vsize_t size; 443 444 /* Sanity check the size. */ 445 size = umd->md_size; 446 addr = uvm_km_zalloc(kernel_map, size); 447 if (!addr) 448 return ENOMEM; 449 450 /* This unit is now configured. */ 451 sc->sc_addr = (caddr_t)addr; /* kernel space */ 452 sc->sc_size = (size_t)size; 453 sc->sc_type = MD_KMEM_ALLOCATED; 454 return 0; 455 } 456 457 #if MEMORY_DISK_SERVER 458 459 /* 460 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 461 * Set config, then become the I/O server for this unit. 462 */ 463 static int 464 md_ioctl_server(sc, umd, proc) 465 struct md_softc *sc; 466 struct md_conf *umd; 467 struct proc *proc; 468 { 469 vaddr_t end; 470 int error; 471 472 /* Sanity check addr, size. */ 473 end = (vaddr_t) (umd->md_addr + umd->md_size); 474 475 if ((end >= VM_MAXUSER_ADDRESS) || 476 (end < ((vaddr_t) umd->md_addr)) ) 477 return EINVAL; 478 479 /* This unit is now configured. */ 480 sc->sc_addr = umd->md_addr; /* user space */ 481 sc->sc_size = umd->md_size; 482 sc->sc_type = MD_UMEM_SERVER; 483 484 /* Become the server daemon */ 485 error = md_server_loop(sc); 486 487 /* This server is now going away! */ 488 sc->sc_type = MD_UNCONFIGURED; 489 sc->sc_addr = 0; 490 sc->sc_size = 0; 491 492 return (error); 493 } 494 495 int md_sleep_pri = PWAIT | PCATCH; 496 497 static int 498 md_server_loop(sc) 499 struct md_softc *sc; 500 { 501 struct buf *bp; 502 caddr_t addr; /* user space address */ 503 size_t off; /* offset into "device" */ 504 size_t xfer; /* amount to transfer */ 505 int error; 506 507 for (;;) { 508 /* Wait for some work to arrive. */ 509 while ((bp = BUFQ_FIRST(&sc->sc_buflist)) == NULL) { 510 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 511 if (error) 512 return error; 513 } 514 515 /* Unlink buf from head of list. */ 516 BUFQ_REMOVE(&sc->sc_buflist, bp); 517 518 /* Do the transfer to/from user space. */ 519 error = 0; 520 bp->b_resid = bp->b_bcount; 521 off = (bp->b_blkno << DEV_BSHIFT); 522 if (off >= sc->sc_size) { 523 if (bp->b_flags & B_READ) 524 goto done; /* EOF (not an error) */ 525 error = EIO; 526 goto done; 527 } 528 xfer = bp->b_resid; 529 if (xfer > (sc->sc_size - off)) 530 xfer = (sc->sc_size - off); 531 addr = sc->sc_addr + off; 532 if (bp->b_flags & B_READ) 533 error = copyin(addr, bp->b_data, xfer); 534 else 535 error = copyout(bp->b_data, addr, xfer); 536 if (!error) 537 bp->b_resid -= xfer; 538 539 done: 540 if (error) { 541 bp->b_error = error; 542 bp->b_flags |= B_ERROR; 543 } 544 biodone(bp); 545 } 546 } 547 #endif /* MEMORY_DISK_SERVER */ 548
Indexes created Fri Sep 26 08:10:20 GMT 2025