md.c revision 1.57
1 /* $NetBSD: md.c,v 1.57 2009/01/13 13:35:52 yamt 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 1.57 2009/01/13 13:35:52 yamt 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); 155 156 bufq_alloc(&sc->sc_buflist, "fcfs", 0); 157 158 /* XXX - Could accept aux info here to set the config. */ 159 #ifdef MEMORY_DISK_HOOKS 160 /* 161 * This external function might setup a pre-loaded disk. 162 * All it would need to do is setup the md_conf struct. 163 * See sys/dev/md_root.c for an example. 164 */ 165 md_attach_hook(device_unit(self), &sc->sc_md); 166 #endif 167 168 /* 169 * Initialize and attach the disk structure. 170 */ 171 disk_init(&sc->sc_dkdev, device_xname(self), &mddkdriver); 172 disk_attach(&sc->sc_dkdev); 173 174 if (!pmf_device_register(self, NULL, NULL)) 175 aprint_error_dev(self, "couldn't establish power handler\n"); 176 } 177 178 /* 179 * operational routines: 180 * open, close, read, write, strategy, 181 * ioctl, dump, size 182 */ 183 184 #if MEMORY_DISK_SERVER 185 static int md_server_loop(struct md_softc *sc); 186 static int md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 187 struct lwp *l); 188 #endif /* MEMORY_DISK_SERVER */ 189 static int md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 190 struct lwp *l); 191 192 static int 193 mdsize(dev_t dev) 194 { 195 struct md_softc *sc; 196 197 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 198 if (sc == NULL) 199 return 0; 200 201 if (sc->sc_type == MD_UNCONFIGURED) 202 return 0; 203 204 return (sc->sc_size >> DEV_BSHIFT); 205 } 206 207 static int 208 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 209 { 210 int unit; 211 struct md_softc *sc; 212 213 unit = MD_UNIT(dev); 214 sc = device_lookup_private(&md_cd, unit); 215 if (sc == NULL) 216 return ENXIO; 217 218 /* 219 * The raw partition is used for ioctl to configure. 220 */ 221 if (DISKPART(dev) == RAW_PART) 222 return 0; 223 224 #ifdef MEMORY_DISK_HOOKS 225 /* Call the open hook to allow loading the device. */ 226 md_open_hook(unit, &sc->sc_md); 227 #endif 228 229 /* 230 * This is a normal, "slave" device, so 231 * enforce initialized. 232 */ 233 if (sc->sc_type == MD_UNCONFIGURED) 234 return ENXIO; 235 236 return 0; 237 } 238 239 static int 240 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 241 { 242 243 return 0; 244 } 245 246 static int 247 mdread(dev_t dev, struct uio *uio, int flags) 248 { 249 struct md_softc *sc; 250 251 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 252 253 if (sc->sc_type == MD_UNCONFIGURED) 254 return ENXIO; 255 256 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 257 } 258 259 static int 260 mdwrite(dev_t dev, struct uio *uio, int flags) 261 { 262 struct md_softc *sc; 263 264 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 265 266 if (sc->sc_type == MD_UNCONFIGURED) 267 return ENXIO; 268 269 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 270 } 271 272 /* 273 * Handle I/O requests, either directly, or 274 * by passing them to the server process. 275 */ 276 static void 277 mdstrategy(struct buf *bp) 278 { 279 struct md_softc *sc; 280 void * addr; 281 size_t off, xfer; 282 283 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 284 285 if (sc->sc_type == MD_UNCONFIGURED) { 286 bp->b_error = ENXIO; 287 goto done; 288 } 289 290 switch (sc->sc_type) { 291 #if MEMORY_DISK_SERVER 292 case MD_UMEM_SERVER: 293 /* Just add this job to the server's queue. */ 294 bufq_put(sc->sc_buflist, bp); 295 wakeup((void *)sc); 296 /* see md_server_loop() */ 297 /* no biodone in this case */ 298 return; 299 #endif /* MEMORY_DISK_SERVER */ 300 301 case MD_KMEM_FIXED: 302 case MD_KMEM_ALLOCATED: 303 /* These are in kernel space. Access directly. */ 304 bp->b_resid = bp->b_bcount; 305 off = (bp->b_blkno << DEV_BSHIFT); 306 if (off >= sc->sc_size) { 307 if (bp->b_flags & B_READ) 308 break; /* EOF */ 309 goto set_eio; 310 } 311 xfer = bp->b_resid; 312 if (xfer > (sc->sc_size - off)) 313 xfer = (sc->sc_size - off); 314 addr = (char *)sc->sc_addr + off; 315 if (bp->b_flags & B_READ) 316 memcpy(bp->b_data, addr, xfer); 317 else 318 memcpy(addr, bp->b_data, xfer); 319 bp->b_resid -= xfer; 320 break; 321 322 default: 323 bp->b_resid = bp->b_bcount; 324 set_eio: 325 bp->b_error = EIO; 326 break; 327 } 328 done: 329 biodone(bp); 330 } 331 332 static int 333 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 334 { 335 struct md_softc *sc; 336 struct md_conf *umd; 337 338 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 339 340 /* If this is not the raw partition, punt! */ 341 if (DISKPART(dev) != RAW_PART) 342 return ENOTTY; 343 344 umd = (struct md_conf *)data; 345 switch (cmd) { 346 case MD_GETCONF: 347 *umd = sc->sc_md; 348 return 0; 349 350 case MD_SETCONF: 351 /* Can only set it once. */ 352 if (sc->sc_type != MD_UNCONFIGURED) 353 break; 354 switch (umd->md_type) { 355 case MD_KMEM_ALLOCATED: 356 return md_ioctl_kalloc(sc, umd, l); 357 #if MEMORY_DISK_SERVER 358 case MD_UMEM_SERVER: 359 return md_ioctl_server(sc, umd, l); 360 #endif /* MEMORY_DISK_SERVER */ 361 default: 362 break; 363 } 364 break; 365 } 366 return EINVAL; 367 } 368 369 /* 370 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 371 * Just allocate some kernel memory and return. 372 */ 373 static int 374 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 375 struct lwp *l) 376 { 377 vaddr_t addr; 378 vsize_t size; 379 380 /* Sanity check the size. */ 381 size = umd->md_size; 382 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 383 if (!addr) 384 return ENOMEM; 385 386 /* This unit is now configured. */ 387 sc->sc_addr = (void *)addr; /* kernel space */ 388 sc->sc_size = (size_t)size; 389 sc->sc_type = MD_KMEM_ALLOCATED; 390 return 0; 391 } 392 393 #if MEMORY_DISK_SERVER 394 395 /* 396 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 397 * Set config, then become the I/O server for this unit. 398 */ 399 static int 400 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 401 struct lwp *l) 402 { 403 vaddr_t end; 404 int error; 405 406 /* Sanity check addr, size. */ 407 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 408 409 if ((end >= VM_MAXUSER_ADDRESS) || 410 (end < ((vaddr_t) umd->md_addr)) ) 411 return EINVAL; 412 413 /* This unit is now configured. */ 414 sc->sc_addr = umd->md_addr; /* user space */ 415 sc->sc_size = umd->md_size; 416 sc->sc_type = MD_UMEM_SERVER; 417 418 /* Become the server daemon */ 419 error = md_server_loop(sc); 420 421 /* This server is now going away! */ 422 sc->sc_type = MD_UNCONFIGURED; 423 sc->sc_addr = 0; 424 sc->sc_size = 0; 425 426 return (error); 427 } 428 429 static int md_sleep_pri = PWAIT | PCATCH; 430 431 static int 432 md_server_loop(struct md_softc *sc) 433 { 434 struct buf *bp; 435 void *addr; /* user space address */ 436 size_t off; /* offset into "device" */ 437 size_t xfer; /* amount to transfer */ 438 int error; 439 440 for (;;) { 441 /* Wait for some work to arrive. */ 442 while ((bp = bufq_get(sc->sc_buflist)) == NULL) { 443 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 444 if (error) 445 return error; 446 } 447 448 /* Do the transfer to/from user space. */ 449 error = 0; 450 bp->b_resid = bp->b_bcount; 451 off = (bp->b_blkno << DEV_BSHIFT); 452 if (off >= sc->sc_size) { 453 if (bp->b_flags & B_READ) 454 goto done; /* EOF (not an error) */ 455 error = EIO; 456 goto done; 457 } 458 xfer = bp->b_resid; 459 if (xfer > (sc->sc_size - off)) 460 xfer = (sc->sc_size - off); 461 addr = (char *)sc->sc_addr + off; 462 if (bp->b_flags & B_READ) 463 error = copyin(addr, bp->b_data, xfer); 464 else 465 error = copyout(bp->b_data, addr, xfer); 466 if (!error) 467 bp->b_resid -= xfer; 468 469 done: 470 if (error) { 471 bp->b_error = error; 472 } 473 biodone(bp); 474 } 475 } 476 #endif /* MEMORY_DISK_SERVER */ 477
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