md.c revision 1.51.18.3
1 /* $NetBSD: md.c,v 1.51.18.3 2008/06/29 09:33:04 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 1.51.18.3 2008/06/29 09:33:04 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_UNIT(unit) DISKUNIT(unit) 81 82 /* autoconfig stuff... */ 83 84 struct md_softc { 85 struct disk sc_dkdev; /* hook for generic disk handling */ 86 struct md_conf sc_md; 87 struct bufq_state *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(int); 95 96 static void md_attach(device_t, device_t, void *); 97 98 static dev_type_open(mdopen); 99 static dev_type_close(mdclose); 100 static dev_type_read(mdread); 101 static dev_type_write(mdwrite); 102 static dev_type_ioctl(mdioctl); 103 static dev_type_strategy(mdstrategy); 104 static dev_type_size(mdsize); 105 106 const struct bdevsw md_bdevsw = { 107 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK 108 }; 109 110 const struct cdevsw md_cdevsw = { 111 mdopen, mdclose, mdread, mdwrite, mdioctl, 112 nostop, notty, nopoll, nommap, nokqfilter, D_DISK 113 }; 114 115 static struct dkdriver mddkdriver = { mdstrategy, NULL }; 116 117 extern struct cfdriver md_cd; 118 CFATTACH_DECL_NEW(md, sizeof(struct md_softc), 119 0, md_attach, 0, NULL); 120 121 /* 122 * This is called if we are configured as a pseudo-device 123 */ 124 void 125 mdattach(int n) 126 { 127 int i; 128 cfdata_t cf; 129 130 if (config_cfattach_attach("md", &md_ca)) { 131 printf("md: cfattach_attach failed\n"); 132 return; 133 } 134 135 /* XXX: Are we supposed to provide a default? */ 136 if (n <= 1) 137 n = 1; 138 139 /* Attach as if by autoconfig. */ 140 for (i = 0; i < n; i++) { 141 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 142 cf->cf_name = "md"; 143 cf->cf_atname = "md"; 144 cf->cf_unit = i; 145 cf->cf_fstate = FSTATE_NOTFOUND; 146 (void)config_attach_pseudo(cf); 147 } 148 } 149 150 static void 151 md_attach(device_t parent, device_t self, 152 void *aux) 153 { 154 struct md_softc *sc = device_private(self); 155 int bmaj, cmaj, unit; 156 157 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 158 159 /* XXX - Could accept aux info here to set the config. */ 160 #ifdef MEMORY_DISK_HOOKS 161 /* 162 * This external function might setup a pre-loaded disk. 163 * All it would need to do is setup the md_conf struct. 164 * See sys/dev/md_root.c for an example. 165 */ 166 md_attach_hook(device_unit(self), &sc->sc_md); 167 #endif 168 169 /* 170 * Initialize and attach the disk structure. 171 */ 172 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 173 disk_attach(&sc->sc_dkdev); 174 175 cmaj = cdevsw_lookup_major(&md_cdevsw); 176 bmaj = bdevsw_lookup_major(&md_bdevsw); 177 unit = device_unit(&sc->sc_dev); 178 179 device_register_name(MAKEDISKDEV(cmaj, unit, 0), &sc->sc_dev, true, 180 DEV_DISK, "r%sa", device_xname(&sc->sc_dev)); 181 device_register_name(MAKEDISKDEV(cmaj, unit, 3), &sc->sc_dev, true, 182 DEV_DISK, "r%sd", device_xname(&sc->sc_dev)); 183 184 device_register_name(MAKEDISKDEV(bmaj, unit, 0), &sc->sc_dev, false, 185 DEV_DISK, "%sa", device_xname(&sc->sc_dev)); 186 device_register_name(MAKEDISKDEV(bmaj, unit, 3), &sc->sc_dev, false, 187 DEV_DISK, "%sd", device_xname(&sc->sc_dev)); 188 189 if (!pmf_device_register(self, NULL, NULL)) 190 aprint_error_dev(self, "couldn't establish power handler\n"); 191 } 192 193 /* 194 * operational routines: 195 * open, close, read, write, strategy, 196 * ioctl, dump, size 197 */ 198 199 #if MEMORY_DISK_SERVER 200 static int md_server_loop(struct md_softc *sc); 201 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 202 struct lwp *l); 203 #endif /* MEMORY_DISK_SERVER */ 204 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 205 struct lwp *l); 206 207 static int 208 mdsize(dev_t dev) 209 { 210 struct md_softc *sc; 211 212 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 213 if (sc == NULL) 214 return 0; 215 216 if (sc->sc_type == MD_UNCONFIGURED) 217 return 0; 218 219 return (sc->sc_size >> DEV_BSHIFT); 220 } 221 222 static int 223 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 224 { 225 int unit; 226 struct md_softc *sc; 227 228 unit = MD_UNIT(dev); 229 sc = device_lookup_private(&md_cd, unit); 230 if (sc == NULL) 231 return ENXIO; 232 233 /* 234 * The raw partition is used for ioctl to configure. 235 */ 236 if (DISKPART(dev) == RAW_PART) 237 return 0; 238 239 #ifdef MEMORY_DISK_HOOKS 240 /* Call the open hook to allow loading the device. */ 241 md_open_hook(unit, &sc->sc_md); 242 #endif 243 244 /* 245 * This is a normal, "slave" device, so 246 * enforce initialized. 247 */ 248 if (sc->sc_type == MD_UNCONFIGURED) 249 return ENXIO; 250 251 return 0; 252 } 253 254 static int 255 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 256 { 257 258 return 0; 259 } 260 261 static int 262 mdread(dev_t dev, struct uio *uio, int flags) 263 { 264 struct md_softc *sc; 265 266 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 267 268 if (sc->sc_type == MD_UNCONFIGURED) 269 return ENXIO; 270 271 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 272 } 273 274 static int 275 mdwrite(dev_t dev, struct uio *uio, int flags) 276 { 277 struct md_softc *sc; 278 279 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 280 281 if (sc->sc_type == MD_UNCONFIGURED) 282 return ENXIO; 283 284 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 285 } 286 287 /* 288 * Handle I/O requests, either directly, or 289 * by passing them to the server process. 290 */ 291 static void 292 mdstrategy(struct buf *bp) 293 { 294 struct md_softc *sc; 295 void * addr; 296 size_t off, xfer; 297 298 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 299 300 if (sc->sc_type == MD_UNCONFIGURED) { 301 bp->b_error = ENXIO; 302 goto done; 303 } 304 305 switch (sc->sc_type) { 306 #if MEMORY_DISK_SERVER 307 case MD_UMEM_SERVER: 308 /* Just add this job to the server's queue. */ 309 BUFQ_PUT(sc->sc_buflist, bp); 310 wakeup((void *)sc); 311 /* see md_server_loop() */ 312 /* no biodone in this case */ 313 return; 314 #endif /* MEMORY_DISK_SERVER */ 315 316 case MD_KMEM_FIXED: 317 case MD_KMEM_ALLOCATED: 318 /* These are in kernel space. Access directly. */ 319 bp->b_resid = bp->b_bcount; 320 off = (bp->b_blkno << DEV_BSHIFT); 321 if (off >= sc->sc_size) { 322 if (bp->b_flags & B_READ) 323 break; /* EOF */ 324 goto set_eio; 325 } 326 xfer = bp->b_resid; 327 if (xfer > (sc->sc_size - off)) 328 xfer = (sc->sc_size - off); 329 addr = (char *)sc->sc_addr + off; 330 if (bp->b_flags & B_READ) 331 memcpy(bp->b_data, addr, xfer); 332 else 333 memcpy(addr, bp->b_data, xfer); 334 bp->b_resid -= xfer; 335 break; 336 337 default: 338 bp->b_resid = bp->b_bcount; 339 set_eio: 340 bp->b_error = EIO; 341 break; 342 } 343 done: 344 biodone(bp); 345 } 346 347 static int 348 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 349 { 350 struct md_softc *sc; 351 struct md_conf *umd; 352 353 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 354 355 /* If this is not the raw partition, punt! */ 356 if (DISKPART(dev) != RAW_PART) 357 return ENOTTY; 358 359 umd = (struct md_conf *)data; 360 switch (cmd) { 361 case MD_GETCONF: 362 *umd = sc->sc_md; 363 return 0; 364 365 case MD_SETCONF: 366 /* Can only set it once. */ 367 if (sc->sc_type != MD_UNCONFIGURED) 368 break; 369 switch (umd->md_type) { 370 case MD_KMEM_ALLOCATED: 371 return md_ioctl_kalloc(sc, umd, l); 372 #if MEMORY_DISK_SERVER 373 case MD_UMEM_SERVER: 374 return md_ioctl_server(sc, umd, l); 375 #endif /* MEMORY_DISK_SERVER */ 376 default: 377 break; 378 } 379 break; 380 } 381 return EINVAL; 382 } 383 384 /* 385 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 386 * Just allocate some kernel memory and return. 387 */ 388 static int 389 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 390 struct lwp *l) 391 { 392 vaddr_t addr; 393 vsize_t size; 394 395 /* Sanity check the size. */ 396 size = umd->md_size; 397 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 398 if (!addr) 399 return ENOMEM; 400 401 /* This unit is now configured. */ 402 sc->sc_addr = (void *)addr; /* kernel space */ 403 sc->sc_size = (size_t)size; 404 sc->sc_type = MD_KMEM_ALLOCATED; 405 return 0; 406 } 407 408 #if MEMORY_DISK_SERVER 409 410 /* 411 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 412 * Set config, then become the I/O server for this unit. 413 */ 414 static int 415 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 416 struct lwp *l) 417 { 418 vaddr_t end; 419 int error; 420 421 /* Sanity check addr, size. */ 422 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 423 424 if ((end >= VM_MAXUSER_ADDRESS) || 425 (end < ((vaddr_t) umd->md_addr)) ) 426 return EINVAL; 427 428 /* This unit is now configured. */ 429 sc->sc_addr = umd->md_addr; /* user space */ 430 sc->sc_size = umd->md_size; 431 sc->sc_type = MD_UMEM_SERVER; 432 433 /* Become the server daemon */ 434 error = md_server_loop(sc); 435 436 /* This server is now going away! */ 437 sc->sc_type = MD_UNCONFIGURED; 438 sc->sc_addr = 0; 439 sc->sc_size = 0; 440 441 return (error); 442 } 443 444 static int md_sleep_pri = PWAIT | PCATCH; 445 446 static int 447 md_server_loop(struct md_softc *sc) 448 { 449 struct buf *bp; 450 void *addr; /* user space address */ 451 size_t off; /* offset into "device" */ 452 size_t xfer; /* amount to transfer */ 453 int error; 454 455 for (;;) { 456 /* Wait for some work to arrive. */ 457 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 458 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 459 if (error) 460 return error; 461 } 462 463 /* Do the transfer to/from user space. */ 464 error = 0; 465 bp->b_resid = bp->b_bcount; 466 off = (bp->b_blkno << DEV_BSHIFT); 467 if (off >= sc->sc_size) { 468 if (bp->b_flags & B_READ) 469 goto done; /* EOF (not an error) */ 470 error = EIO; 471 goto done; 472 } 473 xfer = bp->b_resid; 474 if (xfer > (sc->sc_size - off)) 475 xfer = (sc->sc_size - off); 476 addr = (char *)sc->sc_addr + off; 477 if (bp->b_flags & B_READ) 478 error = copyin(addr, bp->b_data, xfer); 479 else 480 error = copyout(bp->b_data, addr, xfer); 481 if (!error) 482 bp->b_resid -= xfer; 483 484 done: 485 if (error) { 486 bp->b_error = error; 487 } 488 biodone(bp); 489 } 490 } 491 #endif /* MEMORY_DISK_SERVER */ 492
Indexes created Tue Sep 30 20:09:53 GMT 2025