md.c revision 1.59
1 /* $NetBSD: md.c,v 1.59 2009/05/19 20:25:41 dyoung 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 1.59 2009/05/19 20:25:41 dyoung Exp $"); 50 51 #include "opt_md.h" 52 #include "opt_tftproot.h" 53 54 #include <sys/param.h> 55 #include <sys/kernel.h> 56 #include <sys/malloc.h> 57 #include <sys/systm.h> 58 #include <sys/buf.h> 59 #include <sys/bufq.h> 60 #include <sys/device.h> 61 #include <sys/disk.h> 62 #include <sys/proc.h> 63 #include <sys/conf.h> 64 #include <sys/disklabel.h> 65 66 #include <uvm/uvm_extern.h> 67 68 #include <dev/md.h> 69 70 /* 71 * The user-space functionality is included by default. 72 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 73 */ 74 #ifndef MEMORY_DISK_SERVER 75 #error MEMORY_DISK_SERVER should be defined by opt_md.h 76 #endif /* MEMORY_DISK_SERVER */ 77 78 /* 79 * We should use the raw partition for ioctl. 80 */ 81 #define MD_UNIT(unit) DISKUNIT(unit) 82 83 /* autoconfig stuff... */ 84 85 struct md_softc { 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(device_t, device_t, void *); 98 static int md_detach(device_t, int); 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 extern struct cfdriver md_cd; 120 CFATTACH_DECL3_NEW(md, sizeof(struct md_softc), 121 0, md_attach, md_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN); 122 123 extern size_t md_root_size; 124 125 /* 126 * This is called if we are configured as a pseudo-device 127 */ 128 void 129 mdattach(int n) 130 { 131 int i; 132 cfdata_t cf; 133 134 #ifdef TFTPROOT 135 /* 136 * Attachement of md0 must be done after md_root_setconf(), 137 * because the RAMdisk is not loaded yet. 138 */ 139 if (md_root_size == 0) 140 return; 141 #endif 142 if (config_cfattach_attach("md", &md_ca)) { 143 printf("md: cfattach_attach failed\n"); 144 return; 145 } 146 147 /* XXX: Are we supposed to provide a default? */ 148 if (n <= 1) 149 n = 1; 150 151 /* Attach as if by autoconfig. */ 152 for (i = 0; i < n; i++) { 153 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 154 cf->cf_name = "md"; 155 cf->cf_atname = "md"; 156 cf->cf_unit = i; 157 cf->cf_fstate = FSTATE_NOTFOUND; 158 (void)config_attach_pseudo(cf); 159 } 160 } 161 162 static void 163 md_attach(device_t parent, device_t self, void *aux) 164 { 165 struct md_softc *sc = device_private(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(self), &sc->sc_md); 177 #endif 178 179 /* 180 * Initialize and attach the disk structure. 181 */ 182 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 183 disk_attach(&sc->sc_dkdev); 184 185 if (!pmf_device_register(self, NULL, NULL)) 186 aprint_error_dev(self, "couldn't establish power handler\n"); 187 } 188 189 static int 190 md_detach(device_t self, int flags) 191 { 192 struct md_softc *sc = device_private(self); 193 int rc; 194 195 rc = 0; 196 mutex_enter(&sc->sc_dkdev.dk_openlock); 197 if (sc->sc_dkdev.dk_openmask == 0) 198 ; /* nothing to do */ 199 else if ((flags & DETACH_FORCE) == 0) 200 rc = EBUSY; 201 mutex_exit(&sc->sc_dkdev.dk_openlock); 202 203 if (rc != 0) 204 return rc; 205 206 pmf_device_deregister(self); 207 disk_detach(&sc->sc_dkdev); 208 disk_destroy(&sc->sc_dkdev); 209 bufq_free(sc->sc_buflist); 210 return 0; 211 } 212 213 /* 214 * operational routines: 215 * open, close, read, write, strategy, 216 * ioctl, dump, size 217 */ 218 219 #if MEMORY_DISK_SERVER 220 static int md_server_loop(struct md_softc *sc); 221 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 222 struct lwp *l); 223 #endif /* MEMORY_DISK_SERVER */ 224 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 225 struct lwp *l); 226 227 static int 228 mdsize(dev_t dev) 229 { 230 struct md_softc *sc; 231 232 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 233 if (sc == NULL) 234 return 0; 235 236 if (sc->sc_type == MD_UNCONFIGURED) 237 return 0; 238 239 return (sc->sc_size >> DEV_BSHIFT); 240 } 241 242 static int 243 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 244 { 245 int unit; 246 struct md_softc *sc; 247 248 unit = MD_UNIT(dev); 249 sc = device_lookup_private(&md_cd, unit); 250 if (sc == NULL) 251 return ENXIO; 252 253 /* 254 * The raw partition is used for ioctl to configure. 255 */ 256 if (DISKPART(dev) == RAW_PART) 257 return 0; 258 259 #ifdef MEMORY_DISK_HOOKS 260 /* Call the open hook to allow loading the device. */ 261 md_open_hook(unit, &sc->sc_md); 262 #endif 263 264 /* 265 * This is a normal, "slave" device, so 266 * enforce initialized. 267 */ 268 if (sc->sc_type == MD_UNCONFIGURED) 269 return ENXIO; 270 271 return 0; 272 } 273 274 static int 275 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 276 { 277 278 return 0; 279 } 280 281 static int 282 mdread(dev_t dev, struct uio *uio, int flags) 283 { 284 struct md_softc *sc; 285 286 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 287 288 if (sc->sc_type == MD_UNCONFIGURED) 289 return ENXIO; 290 291 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 292 } 293 294 static int 295 mdwrite(dev_t dev, struct uio *uio, int flags) 296 { 297 struct md_softc *sc; 298 299 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 300 301 if (sc->sc_type == MD_UNCONFIGURED) 302 return ENXIO; 303 304 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 305 } 306 307 /* 308 * Handle I/O requests, either directly, or 309 * by passing them to the server process. 310 */ 311 static void 312 mdstrategy(struct buf *bp) 313 { 314 struct md_softc *sc; 315 void * addr; 316 size_t off, xfer; 317 318 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 319 320 if (sc->sc_type == MD_UNCONFIGURED) { 321 bp->b_error = ENXIO; 322 goto done; 323 } 324 325 switch (sc->sc_type) { 326 #if MEMORY_DISK_SERVER 327 case MD_UMEM_SERVER: 328 /* Just add this job to the server's queue. */ 329 bufq_put(sc->sc_buflist, bp); 330 wakeup((void *)sc); 331 /* see md_server_loop() */ 332 /* no biodone in this case */ 333 return; 334 #endif /* MEMORY_DISK_SERVER */ 335 336 case MD_KMEM_FIXED: 337 case MD_KMEM_ALLOCATED: 338 /* These are in kernel space. Access directly. */ 339 bp->b_resid = bp->b_bcount; 340 off = (bp->b_blkno << DEV_BSHIFT); 341 if (off >= sc->sc_size) { 342 if (bp->b_flags & B_READ) 343 break; /* EOF */ 344 goto set_eio; 345 } 346 xfer = bp->b_resid; 347 if (xfer > (sc->sc_size - off)) 348 xfer = (sc->sc_size - off); 349 addr = (char *)sc->sc_addr + off; 350 if (bp->b_flags & B_READ) 351 memcpy(bp->b_data, addr, xfer); 352 else 353 memcpy(addr, bp->b_data, xfer); 354 bp->b_resid -= xfer; 355 break; 356 357 default: 358 bp->b_resid = bp->b_bcount; 359 set_eio: 360 bp->b_error = EIO; 361 break; 362 } 363 done: 364 biodone(bp); 365 } 366 367 static int 368 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 369 { 370 struct md_softc *sc; 371 struct md_conf *umd; 372 373 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 374 375 /* If this is not the raw partition, punt! */ 376 if (DISKPART(dev) != RAW_PART) 377 return ENOTTY; 378 379 umd = (struct md_conf *)data; 380 switch (cmd) { 381 case MD_GETCONF: 382 *umd = sc->sc_md; 383 return 0; 384 385 case MD_SETCONF: 386 /* Can only set it once. */ 387 if (sc->sc_type != MD_UNCONFIGURED) 388 break; 389 switch (umd->md_type) { 390 case MD_KMEM_ALLOCATED: 391 return md_ioctl_kalloc(sc, umd, l); 392 #if MEMORY_DISK_SERVER 393 case MD_UMEM_SERVER: 394 return md_ioctl_server(sc, umd, l); 395 #endif /* MEMORY_DISK_SERVER */ 396 default: 397 break; 398 } 399 break; 400 } 401 return EINVAL; 402 } 403 404 /* 405 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 406 * Just allocate some kernel memory and return. 407 */ 408 static int 409 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 410 struct lwp *l) 411 { 412 vaddr_t addr; 413 vsize_t size; 414 415 /* Sanity check the size. */ 416 size = umd->md_size; 417 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 418 if (!addr) 419 return ENOMEM; 420 421 /* This unit is now configured. */ 422 sc->sc_addr = (void *)addr; /* kernel space */ 423 sc->sc_size = (size_t)size; 424 sc->sc_type = MD_KMEM_ALLOCATED; 425 return 0; 426 } 427 428 #if MEMORY_DISK_SERVER 429 430 /* 431 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 432 * Set config, then become the I/O server for this unit. 433 */ 434 static int 435 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 436 struct lwp *l) 437 { 438 vaddr_t end; 439 int error; 440 441 /* Sanity check addr, size. */ 442 end = (vaddr_t) ((char *)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 void *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((void *)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 = (char *)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 } 508 biodone(bp); 509 } 510 } 511 #endif /* MEMORY_DISK_SERVER */ 512
Indexes created Fri Sep 26 08:10:20 GMT 2025