md.c revision 1.23
1 /* $NetBSD: md.c,v 1.23 2000/06/26 14:21:10 mrg 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 <vm/vm.h> 62 63 #include <uvm/uvm_extern.h> 64 65 #include <dev/md.h> 66 67 /* 68 * By default, include the user-space functionality. 69 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 70 */ 71 #ifndef MEMORY_DISK_SERVER 72 #define MEMORY_DISK_SERVER 1 73 #endif 74 75 /* 76 * We should use the raw partition for ioctl. 77 */ 78 #define MD_MAX_UNITS 0x10 79 #define MD_UNIT(unit) DISKUNIT(unit) 80 81 /* autoconfig stuff... */ 82 83 struct md_softc { 84 struct device sc_dev; /* REQUIRED first entry */ 85 struct disk sc_dkdev; /* hook for generic disk handling */ 86 struct md_conf sc_md; 87 struct buf_queue sc_buflist; 88 }; 89 /* shorthand for fields in sc_md: */ 90 #define sc_addr sc_md.md_addr 91 #define sc_size sc_md.md_size 92 #define sc_type sc_md.md_type 93 94 void mdattach __P((int)); 95 static void md_attach __P((struct device *, struct device *, void *)); 96 97 void mdstrategy __P((struct buf *bp)); 98 struct dkdriver mddkdriver = { mdstrategy }; 99 100 static int ramdisk_ndevs; 101 static void *ramdisk_devs[MD_MAX_UNITS]; 102 103 /* 104 * This is called if we are configured as a pseudo-device 105 */ 106 void 107 mdattach(n) 108 int n; 109 { 110 struct md_softc *sc; 111 int i; 112 113 #ifdef DIAGNOSTIC 114 if (ramdisk_ndevs) { 115 printf("ramdisk: multiple attach calls?\n"); 116 return; 117 } 118 #endif 119 120 /* XXX: Are we supposed to provide a default? */ 121 if (n <= 1) 122 n = 1; 123 if (n > MD_MAX_UNITS) 124 n = MD_MAX_UNITS; 125 ramdisk_ndevs = n; 126 127 /* Attach as if by autoconfig. */ 128 for (i = 0; i < n; i++) { 129 130 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT); 131 if (!sc) { 132 printf("ramdisk: malloc for attach failed!\n"); 133 return; 134 } 135 bzero((caddr_t)sc, sizeof(*sc)); 136 ramdisk_devs[i] = sc; 137 sc->sc_dev.dv_unit = i; 138 sprintf(sc->sc_dev.dv_xname, "md%d", i); 139 md_attach(NULL, &sc->sc_dev, NULL); 140 } 141 } 142 143 static void 144 md_attach(parent, self, aux) 145 struct device *parent, *self; 146 void *aux; 147 { 148 struct md_softc *sc = (struct md_softc *)self; 149 150 BUFQ_INIT(&sc->sc_buflist); 151 152 /* XXX - Could accept aux info here to set the config. */ 153 #ifdef MEMORY_DISK_HOOKS 154 /* 155 * This external function might setup a pre-loaded disk. 156 * All it would need to do is setup the md_conf struct. 157 * See sys/arch/sun3/dev/md_root.c for an example. 158 */ 159 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 160 #endif 161 162 /* 163 * Initialize and attach the disk structure. 164 */ 165 sc->sc_dkdev.dk_driver = &mddkdriver; 166 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 167 disk_attach(&sc->sc_dkdev); 168 } 169 170 /* 171 * operational routines: 172 * open, close, read, write, strategy, 173 * ioctl, dump, size 174 */ 175 176 #if MEMORY_DISK_SERVER 177 static int md_server_loop __P((struct md_softc *sc)); 178 static int md_ioctl_server __P((struct md_softc *sc, 179 struct md_conf *umd, struct proc *proc)); 180 #endif 181 static int md_ioctl_kalloc __P((struct md_softc *sc, 182 struct md_conf *umd, struct proc *proc)); 183 184 dev_type_open(mdopen); 185 dev_type_close(mdclose); 186 dev_type_read(mdread); 187 dev_type_write(mdwrite); 188 dev_type_ioctl(mdioctl); 189 dev_type_size(mdsize); 190 dev_type_dump(mddump); 191 192 int 193 mddump(dev, blkno, va, size) 194 dev_t dev; 195 daddr_t blkno; 196 caddr_t va; 197 size_t size; 198 { 199 return ENODEV; 200 } 201 202 int 203 mdsize(dev_t dev) 204 { 205 int unit; 206 struct md_softc *sc; 207 208 unit = MD_UNIT(dev); 209 if (unit >= ramdisk_ndevs) 210 return 0; 211 sc = ramdisk_devs[unit]; 212 if (sc == NULL) 213 return 0; 214 215 if (sc->sc_type == MD_UNCONFIGURED) 216 return 0; 217 218 return (sc->sc_size >> DEV_BSHIFT); 219 } 220 221 int 222 mdopen(dev, flag, fmt, proc) 223 dev_t dev; 224 int flag, fmt; 225 struct proc *proc; 226 { 227 int unit; 228 struct md_softc *sc; 229 230 unit = MD_UNIT(dev); 231 if (unit >= ramdisk_ndevs) 232 return ENXIO; 233 sc = ramdisk_devs[unit]; 234 if (sc == NULL) 235 return ENXIO; 236 237 /* 238 * The raw partition is used for ioctl to configure. 239 */ 240 if (DISKPART(dev) == RAW_PART) 241 return 0; 242 243 #ifdef MEMORY_DISK_HOOKS 244 /* Call the open hook to allow loading the device. */ 245 md_open_hook(unit, &sc->sc_md); 246 #endif 247 248 /* 249 * This is a normal, "slave" device, so 250 * enforce initialized. 251 */ 252 if (sc->sc_type == MD_UNCONFIGURED) 253 return ENXIO; 254 255 return 0; 256 } 257 258 int 259 mdclose(dev, flag, fmt, proc) 260 dev_t dev; 261 int flag, fmt; 262 struct proc *proc; 263 { 264 int unit; 265 266 unit = MD_UNIT(dev); 267 268 if (unit >= ramdisk_ndevs) 269 return ENXIO; 270 271 return 0; 272 } 273 274 int 275 mdread(dev, uio, flags) 276 dev_t dev; 277 struct uio *uio; 278 int flags; 279 { 280 int unit; 281 struct md_softc *sc; 282 283 unit = MD_UNIT(dev); 284 285 if (unit >= ramdisk_ndevs) 286 return ENXIO; 287 288 sc = ramdisk_devs[unit]; 289 290 if (sc->sc_type == MD_UNCONFIGURED) 291 return ENXIO; 292 293 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 294 } 295 296 int 297 mdwrite(dev, uio, flags) 298 dev_t dev; 299 struct uio *uio; 300 int flags; 301 { 302 int unit; 303 struct md_softc *sc; 304 305 unit = MD_UNIT(dev); 306 307 if (unit >= ramdisk_ndevs) 308 return ENXIO; 309 310 sc = ramdisk_devs[unit]; 311 312 if (sc->sc_type == MD_UNCONFIGURED) 313 return ENXIO; 314 315 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 316 } 317 318 /* 319 * Handle I/O requests, either directly, or 320 * by passing them to the server process. 321 */ 322 void 323 mdstrategy(bp) 324 struct buf *bp; 325 { 326 int unit; 327 struct md_softc *sc; 328 caddr_t addr; 329 size_t off, xfer; 330 331 unit = MD_UNIT(bp->b_dev); 332 sc = ramdisk_devs[unit]; 333 334 if (sc->sc_type == MD_UNCONFIGURED) { 335 bp->b_error = ENXIO; 336 bp->b_flags |= B_ERROR; 337 goto done; 338 } 339 340 switch (sc->sc_type) { 341 #if MEMORY_DISK_SERVER 342 case MD_UMEM_SERVER: 343 /* Just add this job to the server's queue. */ 344 BUFQ_INSERT_TAIL(&sc->sc_buflist, bp); 345 if (BUFQ_FIRST(&sc->sc_buflist) == bp) { 346 /* server queue was empty. */ 347 wakeup((caddr_t)sc); 348 /* see md_server_loop() */ 349 } 350 /* no biodone in this case */ 351 return; 352 #endif /* MEMORY_DISK_SERVER */ 353 354 case MD_KMEM_FIXED: 355 case MD_KMEM_ALLOCATED: 356 /* These are in kernel space. Access directly. */ 357 bp->b_resid = bp->b_bcount; 358 off = (bp->b_blkno << DEV_BSHIFT); 359 if (off >= sc->sc_size) { 360 if (bp->b_flags & B_READ) 361 break; /* EOF */ 362 goto set_eio; 363 } 364 xfer = bp->b_resid; 365 if (xfer > (sc->sc_size - off)) 366 xfer = (sc->sc_size - off); 367 addr = sc->sc_addr + off; 368 if (bp->b_flags & B_READ) 369 bcopy(addr, bp->b_data, xfer); 370 else 371 bcopy(bp->b_data, addr, xfer); 372 bp->b_resid -= xfer; 373 break; 374 375 default: 376 bp->b_resid = bp->b_bcount; 377 set_eio: 378 bp->b_error = EIO; 379 bp->b_flags |= B_ERROR; 380 break; 381 } 382 done: 383 biodone(bp); 384 } 385 386 int 387 mdioctl(dev, cmd, data, flag, proc) 388 dev_t dev; 389 u_long cmd; 390 int flag; 391 caddr_t data; 392 struct proc *proc; 393 { 394 int unit; 395 struct md_softc *sc; 396 struct md_conf *umd; 397 398 unit = MD_UNIT(dev); 399 sc = ramdisk_devs[unit]; 400 401 /* If this is not the raw partition, punt! */ 402 if (DISKPART(dev) != RAW_PART) 403 return ENOTTY; 404 405 umd = (struct md_conf *)data; 406 switch (cmd) { 407 case MD_GETCONF: 408 *umd = sc->sc_md; 409 return 0; 410 411 case MD_SETCONF: 412 /* Can only set it once. */ 413 if (sc->sc_type != MD_UNCONFIGURED) 414 break; 415 switch (umd->md_type) { 416 case MD_KMEM_ALLOCATED: 417 return md_ioctl_kalloc(sc, umd, proc); 418 #if MEMORY_DISK_SERVER 419 case MD_UMEM_SERVER: 420 return md_ioctl_server(sc, umd, proc); 421 #endif 422 default: 423 break; 424 } 425 break; 426 } 427 return EINVAL; 428 } 429 430 /* 431 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 432 * Just allocate some kernel memory and return. 433 */ 434 static int 435 md_ioctl_kalloc(sc, umd, proc) 436 struct md_softc *sc; 437 struct md_conf *umd; 438 struct proc *proc; 439 { 440 vaddr_t addr; 441 vsize_t size; 442 443 /* Sanity check the size. */ 444 size = umd->md_size; 445 addr = uvm_km_zalloc(kernel_map, size); 446 if (!addr) 447 return ENOMEM; 448 449 /* This unit is now configured. */ 450 sc->sc_addr = (caddr_t)addr; /* kernel space */ 451 sc->sc_size = (size_t)size; 452 sc->sc_type = MD_KMEM_ALLOCATED; 453 return 0; 454 } 455 456 #if MEMORY_DISK_SERVER 457 458 /* 459 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 460 * Set config, then become the I/O server for this unit. 461 */ 462 static int 463 md_ioctl_server(sc, umd, proc) 464 struct md_softc *sc; 465 struct md_conf *umd; 466 struct proc *proc; 467 { 468 vaddr_t end; 469 int error; 470 471 /* Sanity check addr, size. */ 472 end = (vaddr_t) (umd->md_addr + umd->md_size); 473 474 if ((end >= VM_MAXUSER_ADDRESS) || 475 (end < ((vaddr_t) umd->md_addr)) ) 476 return EINVAL; 477 478 /* This unit is now configured. */ 479 sc->sc_addr = umd->md_addr; /* user space */ 480 sc->sc_size = umd->md_size; 481 sc->sc_type = MD_UMEM_SERVER; 482 483 /* Become the server daemon */ 484 error = md_server_loop(sc); 485 486 /* This server is now going away! */ 487 sc->sc_type = MD_UNCONFIGURED; 488 sc->sc_addr = 0; 489 sc->sc_size = 0; 490 491 return (error); 492 } 493 494 int md_sleep_pri = PWAIT | PCATCH; 495 496 static int 497 md_server_loop(sc) 498 struct md_softc *sc; 499 { 500 struct buf *bp; 501 caddr_t addr; /* user space address */ 502 size_t off; /* offset into "device" */ 503 size_t xfer; /* amount to transfer */ 504 int error; 505 506 for (;;) { 507 /* Wait for some work to arrive. */ 508 while ((bp = BUFQ_FIRST(&sc->sc_buflist)) == NULL) { 509 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 510 if (error) 511 return error; 512 } 513 514 /* Unlink buf from head of list. */ 515 BUFQ_REMOVE(&sc->sc_buflist, bp); 516 517 /* Do the transfer to/from user space. */ 518 error = 0; 519 bp->b_resid = bp->b_bcount; 520 off = (bp->b_blkno << DEV_BSHIFT); 521 if (off >= sc->sc_size) { 522 if (bp->b_flags & B_READ) 523 goto done; /* EOF (not an error) */ 524 error = EIO; 525 goto done; 526 } 527 xfer = bp->b_resid; 528 if (xfer > (sc->sc_size - off)) 529 xfer = (sc->sc_size - off); 530 addr = sc->sc_addr + off; 531 if (bp->b_flags & B_READ) 532 error = copyin(addr, bp->b_data, xfer); 533 else 534 error = copyout(bp->b_data, addr, xfer); 535 if (!error) 536 bp->b_resid -= xfer; 537 538 done: 539 if (error) { 540 bp->b_error = error; 541 bp->b_flags |= B_ERROR; 542 } 543 biodone(bp); 544 } 545 } 546 #endif /* MEMORY_DISK_SERVER */ 547
Indexes created Thu Sep 25 16:09:42 GMT 2025