md.c revision 1.38
1 /* $NetBSD: md.c,v 1.38 2004/08/30 00:34:42 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 1.38 2004/08/30 00:34:42 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(int); 96 97 static void md_attach(struct device *, struct device *, void *); 98 99 static dev_type_open(mdopen); 100 static dev_type_close(mdclose); 101 static dev_type_read(mdread); 102 static dev_type_write(mdwrite); 103 static dev_type_ioctl(mdioctl); 104 static dev_type_strategy(mdstrategy); 105 static dev_type_size(mdsize); 106 107 const struct bdevsw md_bdevsw = { 108 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK 109 }; 110 111 const struct cdevsw md_cdevsw = { 112 mdopen, mdclose, mdread, mdwrite, mdioctl, 113 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 114 }; 115 116 static struct dkdriver mddkdriver = { mdstrategy }; 117 118 static int ramdisk_ndevs; 119 static void *ramdisk_devs[MD_MAX_UNITS]; 120 121 /* 122 * This is called if we are configured as a pseudo-device 123 */ 124 void 125 mdattach(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 snprintf(sc->sc_dev.dv_xname, sizeof(sc->sc_dev.dv_xname), 155 "md%d", i); 156 md_attach(NULL, &sc->sc_dev, NULL); 157 } 158 } 159 160 static void 161 md_attach(struct device *parent, struct device *self, void *aux) 162 { 163 struct md_softc *sc = (struct md_softc *)self; 164 165 bufq_alloc(&sc->sc_buflist, BUFQ_FCFS); 166 167 /* XXX - Could accept aux info here to set the config. */ 168 #ifdef MEMORY_DISK_HOOKS 169 /* 170 * This external function might setup a pre-loaded disk. 171 * All it would need to do is setup the md_conf struct. 172 * See sys/dev/md_root.c for an example. 173 */ 174 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 175 #endif 176 177 /* 178 * Initialize and attach the disk structure. 179 */ 180 sc->sc_dkdev.dk_driver = &mddkdriver; 181 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 182 disk_attach(&sc->sc_dkdev); 183 } 184 185 /* 186 * operational routines: 187 * open, close, read, write, strategy, 188 * ioctl, dump, size 189 */ 190 191 #if MEMORY_DISK_SERVER 192 static int md_server_loop(struct md_softc *sc); 193 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 194 struct proc *proc); 195 #endif /* MEMORY_DISK_SERVER */ 196 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 197 struct proc *proc); 198 199 static int 200 mdsize(dev_t dev) 201 { 202 int unit; 203 struct md_softc *sc; 204 205 unit = MD_UNIT(dev); 206 if (unit >= ramdisk_ndevs) 207 return 0; 208 sc = ramdisk_devs[unit]; 209 if (sc == NULL) 210 return 0; 211 212 if (sc->sc_type == MD_UNCONFIGURED) 213 return 0; 214 215 return (sc->sc_size >> DEV_BSHIFT); 216 } 217 218 static int 219 mdopen(dev_t dev, int flag, int fmt, struct proc *proc) 220 { 221 int unit; 222 struct md_softc *sc; 223 224 unit = MD_UNIT(dev); 225 if (unit >= ramdisk_ndevs) 226 return ENXIO; 227 sc = ramdisk_devs[unit]; 228 if (sc == NULL) 229 return ENXIO; 230 231 /* 232 * The raw partition is used for ioctl to configure. 233 */ 234 if (DISKPART(dev) == RAW_PART) 235 return 0; 236 237 #ifdef MEMORY_DISK_HOOKS 238 /* Call the open hook to allow loading the device. */ 239 md_open_hook(unit, &sc->sc_md); 240 #endif 241 242 /* 243 * This is a normal, "slave" device, so 244 * enforce initialized. 245 */ 246 if (sc->sc_type == MD_UNCONFIGURED) 247 return ENXIO; 248 249 return 0; 250 } 251 252 static int 253 mdclose(dev_t dev, int flag, int fmt, struct proc *proc) 254 { 255 int unit; 256 257 unit = MD_UNIT(dev); 258 259 if (unit >= ramdisk_ndevs) 260 return ENXIO; 261 262 return 0; 263 } 264 265 static int 266 mdread(dev_t dev, struct uio *uio, int flags) 267 { 268 int unit; 269 struct md_softc *sc; 270 271 unit = MD_UNIT(dev); 272 273 if (unit >= ramdisk_ndevs) 274 return ENXIO; 275 276 sc = ramdisk_devs[unit]; 277 278 if (sc->sc_type == MD_UNCONFIGURED) 279 return ENXIO; 280 281 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 282 } 283 284 static int 285 mdwrite(dev_t dev, struct uio *uio, int flags) 286 { 287 int unit; 288 struct md_softc *sc; 289 290 unit = MD_UNIT(dev); 291 292 if (unit >= ramdisk_ndevs) 293 return ENXIO; 294 295 sc = ramdisk_devs[unit]; 296 297 if (sc->sc_type == MD_UNCONFIGURED) 298 return ENXIO; 299 300 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 301 } 302 303 /* 304 * Handle I/O requests, either directly, or 305 * by passing them to the server process. 306 */ 307 static void 308 mdstrategy(struct buf *bp) 309 { 310 int unit; 311 struct md_softc *sc; 312 caddr_t addr; 313 size_t off, xfer; 314 315 unit = MD_UNIT(bp->b_dev); 316 sc = ramdisk_devs[unit]; 317 318 if (sc->sc_type == MD_UNCONFIGURED) { 319 bp->b_error = ENXIO; 320 bp->b_flags |= B_ERROR; 321 goto done; 322 } 323 324 switch (sc->sc_type) { 325 #if MEMORY_DISK_SERVER 326 case MD_UMEM_SERVER: 327 /* Just add this job to the server's queue. */ 328 BUFQ_PUT(&sc->sc_buflist, bp); 329 wakeup((caddr_t)sc); 330 /* see md_server_loop() */ 331 /* no biodone in this case */ 332 return; 333 #endif /* MEMORY_DISK_SERVER */ 334 335 case MD_KMEM_FIXED: 336 case MD_KMEM_ALLOCATED: 337 /* These are in kernel space. Access directly. */ 338 bp->b_resid = bp->b_bcount; 339 off = (bp->b_blkno << DEV_BSHIFT); 340 if (off >= sc->sc_size) { 341 if (bp->b_flags & B_READ) 342 break; /* EOF */ 343 goto set_eio; 344 } 345 xfer = bp->b_resid; 346 if (xfer > (sc->sc_size - off)) 347 xfer = (sc->sc_size - off); 348 addr = sc->sc_addr + off; 349 if (bp->b_flags & B_READ) 350 memcpy(bp->b_data, addr, xfer); 351 else 352 memcpy(addr, bp->b_data, xfer); 353 bp->b_resid -= xfer; 354 break; 355 356 default: 357 bp->b_resid = bp->b_bcount; 358 set_eio: 359 bp->b_error = EIO; 360 bp->b_flags |= B_ERROR; 361 break; 362 } 363 done: 364 biodone(bp); 365 } 366 367 static int 368 mdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *proc) 369 { 370 int unit; 371 struct md_softc *sc; 372 struct md_conf *umd; 373 374 unit = MD_UNIT(dev); 375 sc = ramdisk_devs[unit]; 376 377 /* If this is not the raw partition, punt! */ 378 if (DISKPART(dev) != RAW_PART) 379 return ENOTTY; 380 381 umd = (struct md_conf *)data; 382 switch (cmd) { 383 case MD_GETCONF: 384 *umd = sc->sc_md; 385 return 0; 386 387 case MD_SETCONF: 388 /* Can only set it once. */ 389 if (sc->sc_type != MD_UNCONFIGURED) 390 break; 391 switch (umd->md_type) { 392 case MD_KMEM_ALLOCATED: 393 return md_ioctl_kalloc(sc, umd, proc); 394 #if MEMORY_DISK_SERVER 395 case MD_UMEM_SERVER: 396 return md_ioctl_server(sc, umd, proc); 397 #endif /* MEMORY_DISK_SERVER */ 398 default: 399 break; 400 } 401 break; 402 } 403 return EINVAL; 404 } 405 406 /* 407 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 408 * Just allocate some kernel memory and return. 409 */ 410 static int 411 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, struct proc *proc) 412 { 413 vaddr_t addr; 414 vsize_t size; 415 416 /* Sanity check the size. */ 417 size = umd->md_size; 418 addr = uvm_km_zalloc(kernel_map, size); 419 if (!addr) 420 return ENOMEM; 421 422 /* This unit is now configured. */ 423 sc->sc_addr = (caddr_t)addr; /* kernel space */ 424 sc->sc_size = (size_t)size; 425 sc->sc_type = MD_KMEM_ALLOCATED; 426 return 0; 427 } 428 429 #if MEMORY_DISK_SERVER 430 431 /* 432 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 433 * Set config, then become the I/O server for this unit. 434 */ 435 static int 436 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, struct proc *proc) 437 { 438 vaddr_t end; 439 int error; 440 441 /* Sanity check addr, size. */ 442 end = (vaddr_t) (umd->md_addr + umd->md_size); 443 444 if ((end >= VM_MAXUSER_ADDRESS) || 445 (end < ((vaddr_t) umd->md_addr)) ) 446 return EINVAL; 447 448 /* This unit is now configured. */ 449 sc->sc_addr = umd->md_addr; /* user space */ 450 sc->sc_size = umd->md_size; 451 sc->sc_type = MD_UMEM_SERVER; 452 453 /* Become the server daemon */ 454 error = md_server_loop(sc); 455 456 /* This server is now going away! */ 457 sc->sc_type = MD_UNCONFIGURED; 458 sc->sc_addr = 0; 459 sc->sc_size = 0; 460 461 return (error); 462 } 463 464 static int md_sleep_pri = PWAIT | PCATCH; 465 466 static int 467 md_server_loop(struct md_softc *sc) 468 { 469 struct buf *bp; 470 caddr_t addr; /* user space address */ 471 size_t off; /* offset into "device" */ 472 size_t xfer; /* amount to transfer */ 473 int error; 474 475 for (;;) { 476 /* Wait for some work to arrive. */ 477 while ((bp = BUFQ_GET(&sc->sc_buflist)) == NULL) { 478 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 479 if (error) 480 return error; 481 } 482 483 /* Do the transfer to/from user space. */ 484 error = 0; 485 bp->b_resid = bp->b_bcount; 486 off = (bp->b_blkno << DEV_BSHIFT); 487 if (off >= sc->sc_size) { 488 if (bp->b_flags & B_READ) 489 goto done; /* EOF (not an error) */ 490 error = EIO; 491 goto done; 492 } 493 xfer = bp->b_resid; 494 if (xfer > (sc->sc_size - off)) 495 xfer = (sc->sc_size - off); 496 addr = sc->sc_addr + off; 497 if (bp->b_flags & B_READ) 498 error = copyin(addr, bp->b_data, xfer); 499 else 500 error = copyout(bp->b_data, addr, xfer); 501 if (!error) 502 bp->b_resid -= xfer; 503 504 done: 505 if (error) { 506 bp->b_error = error; 507 bp->b_flags |= B_ERROR; 508 } 509 biodone(bp); 510 } 511 } 512 #endif /* MEMORY_DISK_SERVER */ 513
Indexes created Thu Sep 25 16:09:42 GMT 2025