md.c revision 1.53
1 /* $NetBSD: md.c,v 1.53 2008/06/11 10:38:44 drochner 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 1.53 2008/06/11 10:38:44 drochner 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 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, NULL }; 117 118 extern struct cfdriver md_cd; 119 CFATTACH_DECL(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 struct md_softc *sc; 129 int i; 130 struct cfdata *cf; 131 132 if (config_cfattach_attach("md", &md_ca)) { 133 printf("md: cfattach_attach failed\n"); 134 return; 135 } 136 137 /* XXX: Are we supposed to provide a default? */ 138 if (n <= 1) 139 n = 1; 140 141 /* Attach as if by autoconfig. */ 142 for (i = 0; i < n; i++) { 143 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 144 cf->cf_name = "md"; 145 cf->cf_atname = "md"; 146 cf->cf_unit = i; 147 cf->cf_fstate = FSTATE_NOTFOUND; 148 sc = (struct md_softc *)config_attach_pseudo(cf); 149 } 150 } 151 152 static void 153 md_attach(struct device *parent, struct device *self, 154 void *aux) 155 { 156 struct md_softc *sc = (struct md_softc *)self; 157 158 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(&sc->sc_dev), &sc->sc_md); 168 #endif 169 170 /* 171 * Initialize and attach the disk structure. 172 */ 173 disk_init(&sc->sc_dkdev, device_xname(&sc->sc_dev), &mddkdriver); 174 disk_attach(&sc->sc_dkdev); 175 } 176 177 /* 178 * operational routines: 179 * open, close, read, write, strategy, 180 * ioctl, dump, size 181 */ 182 183 #if MEMORY_DISK_SERVER 184 static int md_server_loop(struct md_softc *sc); 185 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 186 struct lwp *l); 187 #endif /* MEMORY_DISK_SERVER */ 188 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 189 struct lwp *l); 190 191 static int 192 mdsize(dev_t dev) 193 { 194 int unit; 195 struct md_softc *sc; 196 197 unit = MD_UNIT(dev); 198 sc = device_lookup_private(&md_cd, unit); 199 if (sc == NULL) 200 return 0; 201 202 if (sc->sc_type == MD_UNCONFIGURED) 203 return 0; 204 205 return (sc->sc_size >> DEV_BSHIFT); 206 } 207 208 static int 209 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 210 { 211 int unit; 212 struct md_softc *sc; 213 214 unit = MD_UNIT(dev); 215 sc = device_lookup_private(&md_cd, unit); 216 if (sc == NULL) 217 return ENXIO; 218 219 /* 220 * The raw partition is used for ioctl to configure. 221 */ 222 if (DISKPART(dev) == RAW_PART) 223 return 0; 224 225 #ifdef MEMORY_DISK_HOOKS 226 /* Call the open hook to allow loading the device. */ 227 md_open_hook(unit, &sc->sc_md); 228 #endif 229 230 /* 231 * This is a normal, "slave" device, so 232 * enforce initialized. 233 */ 234 if (sc->sc_type == MD_UNCONFIGURED) 235 return ENXIO; 236 237 return 0; 238 } 239 240 static int 241 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 242 { 243 244 return 0; 245 } 246 247 static int 248 mdread(dev_t dev, struct uio *uio, int flags) 249 { 250 int unit; 251 struct md_softc *sc; 252 253 unit = MD_UNIT(dev); 254 255 sc = device_lookup_private(&md_cd, unit); 256 257 if (sc->sc_type == MD_UNCONFIGURED) 258 return ENXIO; 259 260 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 261 } 262 263 static int 264 mdwrite(dev_t dev, struct uio *uio, int flags) 265 { 266 int unit; 267 struct md_softc *sc; 268 269 unit = MD_UNIT(dev); 270 271 sc = device_lookup_private(&md_cd, unit); 272 273 if (sc->sc_type == MD_UNCONFIGURED) 274 return ENXIO; 275 276 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 277 } 278 279 /* 280 * Handle I/O requests, either directly, or 281 * by passing them to the server process. 282 */ 283 static void 284 mdstrategy(struct buf *bp) 285 { 286 int unit; 287 struct md_softc *sc; 288 void * addr; 289 size_t off, xfer; 290 291 unit = MD_UNIT(bp->b_dev); 292 sc = device_lookup_private(&md_cd, unit); 293 294 if (sc->sc_type == MD_UNCONFIGURED) { 295 bp->b_error = ENXIO; 296 goto done; 297 } 298 299 switch (sc->sc_type) { 300 #if MEMORY_DISK_SERVER 301 case MD_UMEM_SERVER: 302 /* Just add this job to the server's queue. */ 303 BUFQ_PUT(sc->sc_buflist, bp); 304 wakeup((void *)sc); 305 /* see md_server_loop() */ 306 /* no biodone in this case */ 307 return; 308 #endif /* MEMORY_DISK_SERVER */ 309 310 case MD_KMEM_FIXED: 311 case MD_KMEM_ALLOCATED: 312 /* These are in kernel space. Access directly. */ 313 bp->b_resid = bp->b_bcount; 314 off = (bp->b_blkno << DEV_BSHIFT); 315 if (off >= sc->sc_size) { 316 if (bp->b_flags & B_READ) 317 break; /* EOF */ 318 goto set_eio; 319 } 320 xfer = bp->b_resid; 321 if (xfer > (sc->sc_size - off)) 322 xfer = (sc->sc_size - off); 323 addr = (char *)sc->sc_addr + off; 324 if (bp->b_flags & B_READ) 325 memcpy(bp->b_data, addr, xfer); 326 else 327 memcpy(addr, bp->b_data, xfer); 328 bp->b_resid -= xfer; 329 break; 330 331 default: 332 bp->b_resid = bp->b_bcount; 333 set_eio: 334 bp->b_error = EIO; 335 break; 336 } 337 done: 338 biodone(bp); 339 } 340 341 static int 342 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 343 { 344 int unit; 345 struct md_softc *sc; 346 struct md_conf *umd; 347 348 unit = MD_UNIT(dev); 349 sc = device_lookup_private(&md_cd, unit); 350 351 /* If this is not the raw partition, punt! */ 352 if (DISKPART(dev) != RAW_PART) 353 return ENOTTY; 354 355 umd = (struct md_conf *)data; 356 switch (cmd) { 357 case MD_GETCONF: 358 *umd = sc->sc_md; 359 return 0; 360 361 case MD_SETCONF: 362 /* Can only set it once. */ 363 if (sc->sc_type != MD_UNCONFIGURED) 364 break; 365 switch (umd->md_type) { 366 case MD_KMEM_ALLOCATED: 367 return md_ioctl_kalloc(sc, umd, l); 368 #if MEMORY_DISK_SERVER 369 case MD_UMEM_SERVER: 370 return md_ioctl_server(sc, umd, l); 371 #endif /* MEMORY_DISK_SERVER */ 372 default: 373 break; 374 } 375 break; 376 } 377 return EINVAL; 378 } 379 380 /* 381 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 382 * Just allocate some kernel memory and return. 383 */ 384 static int 385 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 386 struct lwp *l) 387 { 388 vaddr_t addr; 389 vsize_t size; 390 391 /* Sanity check the size. */ 392 size = umd->md_size; 393 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 394 if (!addr) 395 return ENOMEM; 396 397 /* This unit is now configured. */ 398 sc->sc_addr = (void *)addr; /* kernel space */ 399 sc->sc_size = (size_t)size; 400 sc->sc_type = MD_KMEM_ALLOCATED; 401 return 0; 402 } 403 404 #if MEMORY_DISK_SERVER 405 406 /* 407 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 408 * Set config, then become the I/O server for this unit. 409 */ 410 static int 411 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 412 struct lwp *l) 413 { 414 vaddr_t end; 415 int error; 416 417 /* Sanity check addr, size. */ 418 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 419 420 if ((end >= VM_MAXUSER_ADDRESS) || 421 (end < ((vaddr_t) umd->md_addr)) ) 422 return EINVAL; 423 424 /* This unit is now configured. */ 425 sc->sc_addr = umd->md_addr; /* user space */ 426 sc->sc_size = umd->md_size; 427 sc->sc_type = MD_UMEM_SERVER; 428 429 /* Become the server daemon */ 430 error = md_server_loop(sc); 431 432 /* This server is now going away! */ 433 sc->sc_type = MD_UNCONFIGURED; 434 sc->sc_addr = 0; 435 sc->sc_size = 0; 436 437 return (error); 438 } 439 440 static int md_sleep_pri = PWAIT | PCATCH; 441 442 static int 443 md_server_loop(struct md_softc *sc) 444 { 445 struct buf *bp; 446 void *addr; /* user space address */ 447 size_t off; /* offset into "device" */ 448 size_t xfer; /* amount to transfer */ 449 int error; 450 451 for (;;) { 452 /* Wait for some work to arrive. */ 453 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 454 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 455 if (error) 456 return error; 457 } 458 459 /* Do the transfer to/from user space. */ 460 error = 0; 461 bp->b_resid = bp->b_bcount; 462 off = (bp->b_blkno << DEV_BSHIFT); 463 if (off >= sc->sc_size) { 464 if (bp->b_flags & B_READ) 465 goto done; /* EOF (not an error) */ 466 error = EIO; 467 goto done; 468 } 469 xfer = bp->b_resid; 470 if (xfer > (sc->sc_size - off)) 471 xfer = (sc->sc_size - off); 472 addr = (char *)sc->sc_addr + off; 473 if (bp->b_flags & B_READ) 474 error = copyin(addr, bp->b_data, xfer); 475 else 476 error = copyout(bp->b_data, addr, xfer); 477 if (!error) 478 bp->b_resid -= xfer; 479 480 done: 481 if (error) { 482 bp->b_error = error; 483 } 484 biodone(bp); 485 } 486 } 487 #endif /* MEMORY_DISK_SERVER */ 488
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