md.c revision 1.55
1 /* $NetBSD: md.c,v 1.55 2008/06/13 20:05:06 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 1.55 2008/06/13 20:05:06 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_UNIT(unit) DISKUNIT(unit) 81 82 /* autoconfig stuff... */ 83 84 struct md_softc { 85 device_t 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(device_t, device_t, 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, NULL }; 117 118 extern struct cfdriver md_cd; 119 CFATTACH_DECL_NEW(md, sizeof(struct md_softc), 120 0, md_attach, 0, NULL); 121 122 /* 123 * This is called if we are configured as a pseudo-device 124 */ 125 void 126 mdattach(int n) 127 { 128 int i; 129 cfdata_t cf; 130 131 if (config_cfattach_attach("md", &md_ca)) { 132 printf("md: cfattach_attach failed\n"); 133 return; 134 } 135 136 /* XXX: Are we supposed to provide a default? */ 137 if (n <= 1) 138 n = 1; 139 140 /* Attach as if by autoconfig. */ 141 for (i = 0; i < n; i++) { 142 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 143 cf->cf_name = "md"; 144 cf->cf_atname = "md"; 145 cf->cf_unit = i; 146 cf->cf_fstate = FSTATE_NOTFOUND; 147 (void)config_attach_pseudo(cf); 148 } 149 } 150 151 static void 152 md_attach(device_t parent, device_t self, 153 void *aux) 154 { 155 struct md_softc *sc = device_private(self); 156 157 sc->sc_dev = self; 158 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 159 160 /* XXX - Could accept aux info here to set the config. */ 161 #ifdef MEMORY_DISK_HOOKS 162 /* 163 * This external function might setup a pre-loaded disk. 164 * All it would need to do is setup the md_conf struct. 165 * See sys/dev/md_root.c for an example. 166 */ 167 md_attach_hook(device_unit(self), &sc->sc_md); 168 #endif 169 170 /* 171 * Initialize and attach the disk structure. 172 */ 173 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 174 disk_attach(&sc->sc_dkdev); 175 176 if (!pmf_device_register(self, NULL, NULL)) 177 aprint_error_dev(self, "couldn't establish power handler\n"); 178 } 179 180 /* 181 * operational routines: 182 * open, close, read, write, strategy, 183 * ioctl, dump, size 184 */ 185 186 #if MEMORY_DISK_SERVER 187 static int md_server_loop(struct md_softc *sc); 188 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 189 struct lwp *l); 190 #endif /* MEMORY_DISK_SERVER */ 191 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 192 struct lwp *l); 193 194 static int 195 mdsize(dev_t dev) 196 { 197 struct md_softc *sc; 198 199 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 200 if (sc == NULL) 201 return 0; 202 203 if (sc->sc_type == MD_UNCONFIGURED) 204 return 0; 205 206 return (sc->sc_size >> DEV_BSHIFT); 207 } 208 209 static int 210 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 211 { 212 int unit; 213 struct md_softc *sc; 214 215 unit = MD_UNIT(dev); 216 sc = device_lookup_private(&md_cd, unit); 217 if (sc == NULL) 218 return ENXIO; 219 220 /* 221 * The raw partition is used for ioctl to configure. 222 */ 223 if (DISKPART(dev) == RAW_PART) 224 return 0; 225 226 #ifdef MEMORY_DISK_HOOKS 227 /* Call the open hook to allow loading the device. */ 228 md_open_hook(unit, &sc->sc_md); 229 #endif 230 231 /* 232 * This is a normal, "slave" device, so 233 * enforce initialized. 234 */ 235 if (sc->sc_type == MD_UNCONFIGURED) 236 return ENXIO; 237 238 return 0; 239 } 240 241 static int 242 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 243 { 244 245 return 0; 246 } 247 248 static int 249 mdread(dev_t dev, struct uio *uio, int flags) 250 { 251 struct md_softc *sc; 252 253 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 254 255 if (sc->sc_type == MD_UNCONFIGURED) 256 return ENXIO; 257 258 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 259 } 260 261 static int 262 mdwrite(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_WRITE, minphys, uio)); 272 } 273 274 /* 275 * Handle I/O requests, either directly, or 276 * by passing them to the server process. 277 */ 278 static void 279 mdstrategy(struct buf *bp) 280 { 281 struct md_softc *sc; 282 void * addr; 283 size_t off, xfer; 284 285 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 286 287 if (sc->sc_type == MD_UNCONFIGURED) { 288 bp->b_error = ENXIO; 289 goto done; 290 } 291 292 switch (sc->sc_type) { 293 #if MEMORY_DISK_SERVER 294 case MD_UMEM_SERVER: 295 /* Just add this job to the server's queue. */ 296 BUFQ_PUT(sc->sc_buflist, bp); 297 wakeup((void *)sc); 298 /* see md_server_loop() */ 299 /* no biodone in this case */ 300 return; 301 #endif /* MEMORY_DISK_SERVER */ 302 303 case MD_KMEM_FIXED: 304 case MD_KMEM_ALLOCATED: 305 /* These are in kernel space. Access directly. */ 306 bp->b_resid = bp->b_bcount; 307 off = (bp->b_blkno << DEV_BSHIFT); 308 if (off >= sc->sc_size) { 309 if (bp->b_flags & B_READ) 310 break; /* EOF */ 311 goto set_eio; 312 } 313 xfer = bp->b_resid; 314 if (xfer > (sc->sc_size - off)) 315 xfer = (sc->sc_size - off); 316 addr = (char *)sc->sc_addr + off; 317 if (bp->b_flags & B_READ) 318 memcpy(bp->b_data, addr, xfer); 319 else 320 memcpy(addr, bp->b_data, xfer); 321 bp->b_resid -= xfer; 322 break; 323 324 default: 325 bp->b_resid = bp->b_bcount; 326 set_eio: 327 bp->b_error = EIO; 328 break; 329 } 330 done: 331 biodone(bp); 332 } 333 334 static int 335 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 336 { 337 struct md_softc *sc; 338 struct md_conf *umd; 339 340 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 341 342 /* If this is not the raw partition, punt! */ 343 if (DISKPART(dev) != RAW_PART) 344 return ENOTTY; 345 346 umd = (struct md_conf *)data; 347 switch (cmd) { 348 case MD_GETCONF: 349 *umd = sc->sc_md; 350 return 0; 351 352 case MD_SETCONF: 353 /* Can only set it once. */ 354 if (sc->sc_type != MD_UNCONFIGURED) 355 break; 356 switch (umd->md_type) { 357 case MD_KMEM_ALLOCATED: 358 return md_ioctl_kalloc(sc, umd, l); 359 #if MEMORY_DISK_SERVER 360 case MD_UMEM_SERVER: 361 return md_ioctl_server(sc, umd, l); 362 #endif /* MEMORY_DISK_SERVER */ 363 default: 364 break; 365 } 366 break; 367 } 368 return EINVAL; 369 } 370 371 /* 372 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 373 * Just allocate some kernel memory and return. 374 */ 375 static int 376 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 377 struct lwp *l) 378 { 379 vaddr_t addr; 380 vsize_t size; 381 382 /* Sanity check the size. */ 383 size = umd->md_size; 384 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 385 if (!addr) 386 return ENOMEM; 387 388 /* This unit is now configured. */ 389 sc->sc_addr = (void *)addr; /* kernel space */ 390 sc->sc_size = (size_t)size; 391 sc->sc_type = MD_KMEM_ALLOCATED; 392 return 0; 393 } 394 395 #if MEMORY_DISK_SERVER 396 397 /* 398 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 399 * Set config, then become the I/O server for this unit. 400 */ 401 static int 402 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 403 struct lwp *l) 404 { 405 vaddr_t end; 406 int error; 407 408 /* Sanity check addr, size. */ 409 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 410 411 if ((end >= VM_MAXUSER_ADDRESS) || 412 (end < ((vaddr_t) umd->md_addr)) ) 413 return EINVAL; 414 415 /* This unit is now configured. */ 416 sc->sc_addr = umd->md_addr; /* user space */ 417 sc->sc_size = umd->md_size; 418 sc->sc_type = MD_UMEM_SERVER; 419 420 /* Become the server daemon */ 421 error = md_server_loop(sc); 422 423 /* This server is now going away! */ 424 sc->sc_type = MD_UNCONFIGURED; 425 sc->sc_addr = 0; 426 sc->sc_size = 0; 427 428 return (error); 429 } 430 431 static int md_sleep_pri = PWAIT | PCATCH; 432 433 static int 434 md_server_loop(struct md_softc *sc) 435 { 436 struct buf *bp; 437 void *addr; /* user space address */ 438 size_t off; /* offset into "device" */ 439 size_t xfer; /* amount to transfer */ 440 int error; 441 442 for (;;) { 443 /* Wait for some work to arrive. */ 444 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 445 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 446 if (error) 447 return error; 448 } 449 450 /* Do the transfer to/from user space. */ 451 error = 0; 452 bp->b_resid = bp->b_bcount; 453 off = (bp->b_blkno << DEV_BSHIFT); 454 if (off >= sc->sc_size) { 455 if (bp->b_flags & B_READ) 456 goto done; /* EOF (not an error) */ 457 error = EIO; 458 goto done; 459 } 460 xfer = bp->b_resid; 461 if (xfer > (sc->sc_size - off)) 462 xfer = (sc->sc_size - off); 463 addr = (char *)sc->sc_addr + off; 464 if (bp->b_flags & B_READ) 465 error = copyin(addr, bp->b_data, xfer); 466 else 467 error = copyout(bp->b_data, addr, xfer); 468 if (!error) 469 bp->b_resid -= xfer; 470 471 done: 472 if (error) { 473 bp->b_error = error; 474 } 475 biodone(bp); 476 } 477 } 478 #endif /* MEMORY_DISK_SERVER */ 479
Indexes created Thu Sep 25 16:09:42 GMT 2025