md.c revision 1.52
1 /* $NetBSD: md.c,v 1.52 2008/04/09 05:47:19 cegger 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 1.52 2008/04/09 05:47:19 cegger 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; 166 167 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 168 169 /* XXX - Could accept aux info here to set the config. */ 170 #ifdef MEMORY_DISK_HOOKS 171 /* 172 * This external function might setup a pre-loaded disk. 173 * All it would need to do is setup the md_conf struct. 174 * See sys/dev/md_root.c for an example. 175 */ 176 md_attach_hook(device_unit(&sc->sc_dev), &sc->sc_md); 177 #endif 178 179 /* 180 * Initialize and attach the disk structure. 181 */ 182 disk_init(&sc->sc_dkdev, device_xname(&sc->sc_dev), &mddkdriver); 183 disk_attach(&sc->sc_dkdev); 184 } 185 186 /* 187 * operational routines: 188 * open, close, read, write, strategy, 189 * ioctl, dump, size 190 */ 191 192 #if MEMORY_DISK_SERVER 193 static int md_server_loop(struct md_softc *sc); 194 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 195 struct lwp *l); 196 #endif /* MEMORY_DISK_SERVER */ 197 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 198 struct lwp *l); 199 200 static 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 static int 220 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 221 { 222 int unit; 223 struct md_softc *sc; 224 225 unit = MD_UNIT(dev); 226 if (unit >= ramdisk_ndevs) 227 return ENXIO; 228 sc = ramdisk_devs[unit]; 229 if (sc == NULL) 230 return ENXIO; 231 232 /* 233 * The raw partition is used for ioctl to configure. 234 */ 235 if (DISKPART(dev) == RAW_PART) 236 return 0; 237 238 #ifdef MEMORY_DISK_HOOKS 239 /* Call the open hook to allow loading the device. */ 240 md_open_hook(unit, &sc->sc_md); 241 #endif 242 243 /* 244 * This is a normal, "slave" device, so 245 * enforce initialized. 246 */ 247 if (sc->sc_type == MD_UNCONFIGURED) 248 return ENXIO; 249 250 return 0; 251 } 252 253 static int 254 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 255 { 256 int unit; 257 258 unit = MD_UNIT(dev); 259 260 if (unit >= ramdisk_ndevs) 261 return ENXIO; 262 263 return 0; 264 } 265 266 static int 267 mdread(dev_t dev, struct uio *uio, int flags) 268 { 269 int unit; 270 struct md_softc *sc; 271 272 unit = MD_UNIT(dev); 273 274 if (unit >= ramdisk_ndevs) 275 return ENXIO; 276 277 sc = ramdisk_devs[unit]; 278 279 if (sc->sc_type == MD_UNCONFIGURED) 280 return ENXIO; 281 282 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 283 } 284 285 static int 286 mdwrite(dev_t dev, struct uio *uio, int flags) 287 { 288 int unit; 289 struct md_softc *sc; 290 291 unit = MD_UNIT(dev); 292 293 if (unit >= ramdisk_ndevs) 294 return ENXIO; 295 296 sc = ramdisk_devs[unit]; 297 298 if (sc->sc_type == MD_UNCONFIGURED) 299 return ENXIO; 300 301 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 302 } 303 304 /* 305 * Handle I/O requests, either directly, or 306 * by passing them to the server process. 307 */ 308 static void 309 mdstrategy(struct buf *bp) 310 { 311 int unit; 312 struct md_softc *sc; 313 void * addr; 314 size_t off, xfer; 315 316 unit = MD_UNIT(bp->b_dev); 317 sc = ramdisk_devs[unit]; 318 319 if (sc->sc_type == MD_UNCONFIGURED) { 320 bp->b_error = ENXIO; 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((void *)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 = (char *)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 break; 361 } 362 done: 363 biodone(bp); 364 } 365 366 static int 367 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 368 { 369 int unit; 370 struct md_softc *sc; 371 struct md_conf *umd; 372 373 unit = MD_UNIT(dev); 374 sc = ramdisk_devs[unit]; 375 376 /* If this is not the raw partition, punt! */ 377 if (DISKPART(dev) != RAW_PART) 378 return ENOTTY; 379 380 umd = (struct md_conf *)data; 381 switch (cmd) { 382 case MD_GETCONF: 383 *umd = sc->sc_md; 384 return 0; 385 386 case MD_SETCONF: 387 /* Can only set it once. */ 388 if (sc->sc_type != MD_UNCONFIGURED) 389 break; 390 switch (umd->md_type) { 391 case MD_KMEM_ALLOCATED: 392 return md_ioctl_kalloc(sc, umd, l); 393 #if MEMORY_DISK_SERVER 394 case MD_UMEM_SERVER: 395 return md_ioctl_server(sc, umd, l); 396 #endif /* MEMORY_DISK_SERVER */ 397 default: 398 break; 399 } 400 break; 401 } 402 return EINVAL; 403 } 404 405 /* 406 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 407 * Just allocate some kernel memory and return. 408 */ 409 static int 410 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 411 struct lwp *l) 412 { 413 vaddr_t addr; 414 vsize_t size; 415 416 /* Sanity check the size. */ 417 size = umd->md_size; 418 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 419 if (!addr) 420 return ENOMEM; 421 422 /* This unit is now configured. */ 423 sc->sc_addr = (void *)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, 437 struct lwp *l) 438 { 439 vaddr_t end; 440 int error; 441 442 /* Sanity check addr, size. */ 443 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 444 445 if ((end >= VM_MAXUSER_ADDRESS) || 446 (end < ((vaddr_t) umd->md_addr)) ) 447 return EINVAL; 448 449 /* This unit is now configured. */ 450 sc->sc_addr = umd->md_addr; /* user space */ 451 sc->sc_size = umd->md_size; 452 sc->sc_type = MD_UMEM_SERVER; 453 454 /* Become the server daemon */ 455 error = md_server_loop(sc); 456 457 /* This server is now going away! */ 458 sc->sc_type = MD_UNCONFIGURED; 459 sc->sc_addr = 0; 460 sc->sc_size = 0; 461 462 return (error); 463 } 464 465 static int md_sleep_pri = PWAIT | PCATCH; 466 467 static int 468 md_server_loop(struct md_softc *sc) 469 { 470 struct buf *bp; 471 void *addr; /* user space address */ 472 size_t off; /* offset into "device" */ 473 size_t xfer; /* amount to transfer */ 474 int error; 475 476 for (;;) { 477 /* Wait for some work to arrive. */ 478 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 479 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 480 if (error) 481 return error; 482 } 483 484 /* Do the transfer to/from user space. */ 485 error = 0; 486 bp->b_resid = bp->b_bcount; 487 off = (bp->b_blkno << DEV_BSHIFT); 488 if (off >= sc->sc_size) { 489 if (bp->b_flags & B_READ) 490 goto done; /* EOF (not an error) */ 491 error = EIO; 492 goto done; 493 } 494 xfer = bp->b_resid; 495 if (xfer > (sc->sc_size - off)) 496 xfer = (sc->sc_size - off); 497 addr = (char *)sc->sc_addr + off; 498 if (bp->b_flags & B_READ) 499 error = copyin(addr, bp->b_data, xfer); 500 else 501 error = copyout(bp->b_data, addr, xfer); 502 if (!error) 503 bp->b_resid -= xfer; 504 505 done: 506 if (error) { 507 bp->b_error = error; 508 } 509 biodone(bp); 510 } 511 } 512 #endif /* MEMORY_DISK_SERVER */ 513
Indexes created Fri Sep 26 08:10:20 GMT 2025