md.c revision 1.51.18.1
1 /* $NetBSD: md.c,v 1.51.18.1 2008/04/05 23:33:20 mjf 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 1.51.18.1 2008/04/05 23:33:20 mjf 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/bufq.h> 59 #include <sys/device.h> 60 #include <sys/disk.h> 61 #include <sys/proc.h> 62 #include <sys/conf.h> 63 #include <sys/disklabel.h> 64 65 #include <uvm/uvm_extern.h> 66 67 #include <dev/md.h> 68 69 /* 70 * The user-space functionality is included by default. 71 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 72 */ 73 #ifndef MEMORY_DISK_SERVER 74 #error MEMORY_DISK_SERVER should be defined by opt_md.h 75 #endif /* MEMORY_DISK_SERVER */ 76 77 /* 78 * We should use the raw partition for ioctl. 79 */ 80 #define MD_MAX_UNITS 0x10 81 #define MD_UNIT(unit) DISKUNIT(unit) 82 83 /* autoconfig stuff... */ 84 85 struct md_softc { 86 struct device sc_dev; /* REQUIRED first entry */ 87 struct disk sc_dkdev; /* hook for generic disk handling */ 88 struct md_conf sc_md; 89 struct bufq_state *sc_buflist; 90 }; 91 /* shorthand for fields in sc_md: */ 92 #define sc_addr sc_md.md_addr 93 #define sc_size sc_md.md_size 94 #define sc_type sc_md.md_type 95 96 void mdattach(int); 97 98 static void md_attach(struct device *, struct device *, void *); 99 100 static dev_type_open(mdopen); 101 static dev_type_close(mdclose); 102 static dev_type_read(mdread); 103 static dev_type_write(mdwrite); 104 static dev_type_ioctl(mdioctl); 105 static dev_type_strategy(mdstrategy); 106 static dev_type_size(mdsize); 107 108 const struct bdevsw md_bdevsw = { 109 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK 110 }; 111 112 const struct cdevsw md_cdevsw = { 113 mdopen, mdclose, mdread, mdwrite, mdioctl, 114 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 115 }; 116 117 static struct dkdriver mddkdriver = { mdstrategy, NULL }; 118 119 static int ramdisk_ndevs; 120 static void *ramdisk_devs[MD_MAX_UNITS]; 121 122 /* 123 * This is called if we are configured as a pseudo-device 124 */ 125 void 126 mdattach(int n) 127 { 128 struct md_softc *sc; 129 int i; 130 131 #ifdef DIAGNOSTIC 132 if (ramdisk_ndevs) { 133 aprint_error("ramdisk: multiple attach calls?\n"); 134 return; 135 } 136 #endif 137 138 /* XXX: Are we supposed to provide a default? */ 139 if (n <= 1) 140 n = 1; 141 if (n > MD_MAX_UNITS) 142 n = MD_MAX_UNITS; 143 ramdisk_ndevs = n; 144 145 /* Attach as if by autoconfig. */ 146 for (i = 0; i < n; i++) { 147 148 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO); 149 if (!sc) { 150 aprint_error("ramdisk: malloc for attach failed!\n"); 151 return; 152 } 153 ramdisk_devs[i] = sc; 154 sc->sc_dev.dv_unit = i; 155 snprintf(sc->sc_dev.dv_xname, sizeof(sc->sc_dev.dv_xname), 156 "md%d", i); 157 md_attach(NULL, &sc->sc_dev, NULL); 158 } 159 } 160 161 static void 162 md_attach(struct device *parent, struct device *self, 163 void *aux) 164 { 165 struct md_softc *sc = (struct md_softc *)self; 166 int bmaj, cmaj, unit; 167 168 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 169 170 /* XXX - Could accept aux info here to set the config. */ 171 #ifdef MEMORY_DISK_HOOKS 172 /* 173 * This external function might setup a pre-loaded disk. 174 * All it would need to do is setup the md_conf struct. 175 * See sys/dev/md_root.c for an example. 176 */ 177 md_attach_hook(device_unit(&sc->sc_dev), &sc->sc_md); 178 #endif 179 180 /* 181 * Initialize and attach the disk structure. 182 */ 183 disk_init(&sc->sc_dkdev, sc->sc_dev.dv_xname, &mddkdriver); 184 disk_attach(&sc->sc_dkdev); 185 186 cmaj = cdevsw_lookup_major(&md_cdevsw); 187 bmaj = bdevsw_lookup_major(&md_bdevsw); 188 unit = device_unit(&sc->sc_dev); 189 190 device_register_name(MAKEDISKDEV(cmaj, unit, 0), &sc->sc_dev, true, 191 DEV_DISK, "r%sa", device_xname(&sc->sc_dev)); 192 device_register_name(MAKEDISKDEV(cmaj, unit, 3), &sc->sc_dev, true, 193 DEV_DISK, "r%sd", device_xname(&sc->sc_dev)); 194 195 device_register_name(MAKEDISKDEV(bmaj, unit, 0), &sc->sc_dev, false, 196 DEV_DISK, "%sa", device_xname(&sc->sc_dev)); 197 device_register_name(MAKEDISKDEV(bmaj, unit, 3), &sc->sc_dev, false, 198 DEV_DISK, "%sd", device_xname(&sc->sc_dev)); 199 } 200 201 /* 202 * operational routines: 203 * open, close, read, write, strategy, 204 * ioctl, dump, size 205 */ 206 207 #if MEMORY_DISK_SERVER 208 static int md_server_loop(struct md_softc *sc); 209 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 210 struct lwp *l); 211 #endif /* MEMORY_DISK_SERVER */ 212 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 213 struct lwp *l); 214 215 static int 216 mdsize(dev_t dev) 217 { 218 int unit; 219 struct md_softc *sc; 220 221 unit = MD_UNIT(dev); 222 if (unit >= ramdisk_ndevs) 223 return 0; 224 sc = ramdisk_devs[unit]; 225 if (sc == NULL) 226 return 0; 227 228 if (sc->sc_type == MD_UNCONFIGURED) 229 return 0; 230 231 return (sc->sc_size >> DEV_BSHIFT); 232 } 233 234 static int 235 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 236 { 237 int unit; 238 struct md_softc *sc; 239 240 unit = MD_UNIT(dev); 241 if (unit >= ramdisk_ndevs) 242 return ENXIO; 243 sc = ramdisk_devs[unit]; 244 if (sc == NULL) 245 return ENXIO; 246 247 /* 248 * The raw partition is used for ioctl to configure. 249 */ 250 if (DISKPART(dev) == RAW_PART) 251 return 0; 252 253 #ifdef MEMORY_DISK_HOOKS 254 /* Call the open hook to allow loading the device. */ 255 md_open_hook(unit, &sc->sc_md); 256 #endif 257 258 /* 259 * This is a normal, "slave" device, so 260 * enforce initialized. 261 */ 262 if (sc->sc_type == MD_UNCONFIGURED) 263 return ENXIO; 264 265 return 0; 266 } 267 268 static int 269 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 270 { 271 int unit; 272 273 unit = MD_UNIT(dev); 274 275 if (unit >= ramdisk_ndevs) 276 return ENXIO; 277 278 return 0; 279 } 280 281 static int 282 mdread(dev_t dev, struct uio *uio, int flags) 283 { 284 int unit; 285 struct md_softc *sc; 286 287 unit = MD_UNIT(dev); 288 289 if (unit >= ramdisk_ndevs) 290 return ENXIO; 291 292 sc = ramdisk_devs[unit]; 293 294 if (sc->sc_type == MD_UNCONFIGURED) 295 return ENXIO; 296 297 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 298 } 299 300 static int 301 mdwrite(dev_t dev, struct uio *uio, 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 static void 324 mdstrategy(struct buf *bp) 325 { 326 int unit; 327 struct md_softc *sc; 328 void * 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 goto done; 337 } 338 339 switch (sc->sc_type) { 340 #if MEMORY_DISK_SERVER 341 case MD_UMEM_SERVER: 342 /* Just add this job to the server's queue. */ 343 BUFQ_PUT(sc->sc_buflist, bp); 344 wakeup((void *)sc); 345 /* see md_server_loop() */ 346 /* no biodone in this case */ 347 return; 348 #endif /* MEMORY_DISK_SERVER */ 349 350 case MD_KMEM_FIXED: 351 case MD_KMEM_ALLOCATED: 352 /* These are in kernel space. Access directly. */ 353 bp->b_resid = bp->b_bcount; 354 off = (bp->b_blkno << DEV_BSHIFT); 355 if (off >= sc->sc_size) { 356 if (bp->b_flags & B_READ) 357 break; /* EOF */ 358 goto set_eio; 359 } 360 xfer = bp->b_resid; 361 if (xfer > (sc->sc_size - off)) 362 xfer = (sc->sc_size - off); 363 addr = (char *)sc->sc_addr + off; 364 if (bp->b_flags & B_READ) 365 memcpy(bp->b_data, addr, xfer); 366 else 367 memcpy(addr, bp->b_data, xfer); 368 bp->b_resid -= xfer; 369 break; 370 371 default: 372 bp->b_resid = bp->b_bcount; 373 set_eio: 374 bp->b_error = EIO; 375 break; 376 } 377 done: 378 biodone(bp); 379 } 380 381 static int 382 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 383 { 384 int unit; 385 struct md_softc *sc; 386 struct md_conf *umd; 387 388 unit = MD_UNIT(dev); 389 sc = ramdisk_devs[unit]; 390 391 /* If this is not the raw partition, punt! */ 392 if (DISKPART(dev) != RAW_PART) 393 return ENOTTY; 394 395 umd = (struct md_conf *)data; 396 switch (cmd) { 397 case MD_GETCONF: 398 *umd = sc->sc_md; 399 return 0; 400 401 case MD_SETCONF: 402 /* Can only set it once. */ 403 if (sc->sc_type != MD_UNCONFIGURED) 404 break; 405 switch (umd->md_type) { 406 case MD_KMEM_ALLOCATED: 407 return md_ioctl_kalloc(sc, umd, l); 408 #if MEMORY_DISK_SERVER 409 case MD_UMEM_SERVER: 410 return md_ioctl_server(sc, umd, l); 411 #endif /* MEMORY_DISK_SERVER */ 412 default: 413 break; 414 } 415 break; 416 } 417 return EINVAL; 418 } 419 420 /* 421 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 422 * Just allocate some kernel memory and return. 423 */ 424 static int 425 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 426 struct lwp *l) 427 { 428 vaddr_t addr; 429 vsize_t size; 430 431 /* Sanity check the size. */ 432 size = umd->md_size; 433 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 434 if (!addr) 435 return ENOMEM; 436 437 /* This unit is now configured. */ 438 sc->sc_addr = (void *)addr; /* kernel space */ 439 sc->sc_size = (size_t)size; 440 sc->sc_type = MD_KMEM_ALLOCATED; 441 return 0; 442 } 443 444 #if MEMORY_DISK_SERVER 445 446 /* 447 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 448 * Set config, then become the I/O server for this unit. 449 */ 450 static int 451 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 452 struct lwp *l) 453 { 454 vaddr_t end; 455 int error; 456 457 /* Sanity check addr, size. */ 458 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 459 460 if ((end >= VM_MAXUSER_ADDRESS) || 461 (end < ((vaddr_t) umd->md_addr)) ) 462 return EINVAL; 463 464 /* This unit is now configured. */ 465 sc->sc_addr = umd->md_addr; /* user space */ 466 sc->sc_size = umd->md_size; 467 sc->sc_type = MD_UMEM_SERVER; 468 469 /* Become the server daemon */ 470 error = md_server_loop(sc); 471 472 /* This server is now going away! */ 473 sc->sc_type = MD_UNCONFIGURED; 474 sc->sc_addr = 0; 475 sc->sc_size = 0; 476 477 return (error); 478 } 479 480 static int md_sleep_pri = PWAIT | PCATCH; 481 482 static int 483 md_server_loop(struct md_softc *sc) 484 { 485 struct buf *bp; 486 void *addr; /* user space address */ 487 size_t off; /* offset into "device" */ 488 size_t xfer; /* amount to transfer */ 489 int error; 490 491 for (;;) { 492 /* Wait for some work to arrive. */ 493 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 494 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 495 if (error) 496 return error; 497 } 498 499 /* Do the transfer to/from user space. */ 500 error = 0; 501 bp->b_resid = bp->b_bcount; 502 off = (bp->b_blkno << DEV_BSHIFT); 503 if (off >= sc->sc_size) { 504 if (bp->b_flags & B_READ) 505 goto done; /* EOF (not an error) */ 506 error = EIO; 507 goto done; 508 } 509 xfer = bp->b_resid; 510 if (xfer > (sc->sc_size - off)) 511 xfer = (sc->sc_size - off); 512 addr = (char *)sc->sc_addr + off; 513 if (bp->b_flags & B_READ) 514 error = copyin(addr, bp->b_data, xfer); 515 else 516 error = copyout(bp->b_data, addr, xfer); 517 if (!error) 518 bp->b_resid -= xfer; 519 520 done: 521 if (error) { 522 bp->b_error = error; 523 } 524 biodone(bp); 525 } 526 } 527 #endif /* MEMORY_DISK_SERVER */ 528
Indexes created Tue Sep 30 20:09:53 GMT 2025