md.c revision 1.54
1 /* $NetBSD: md.c,v 1.54 2008/06/13 19:55:26 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 1.54 2008/06/13 19:55:26 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 } 176 177 /* 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 struct md_softc *sc; 195 196 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 197 if (sc == NULL) 198 return 0; 199 200 if (sc->sc_type == MD_UNCONFIGURED) 201 return 0; 202 203 return (sc->sc_size >> DEV_BSHIFT); 204 } 205 206 static int 207 mdopen(dev_t dev, int flag, int fmt, struct lwp *l) 208 { 209 int unit; 210 struct md_softc *sc; 211 212 unit = MD_UNIT(dev); 213 sc = device_lookup_private(&md_cd, unit); 214 if (sc == NULL) 215 return ENXIO; 216 217 /* 218 * The raw partition is used for ioctl to configure. 219 */ 220 if (DISKPART(dev) == RAW_PART) 221 return 0; 222 223 #ifdef MEMORY_DISK_HOOKS 224 /* Call the open hook to allow loading the device. */ 225 md_open_hook(unit, &sc->sc_md); 226 #endif 227 228 /* 229 * This is a normal, "slave" device, so 230 * enforce initialized. 231 */ 232 if (sc->sc_type == MD_UNCONFIGURED) 233 return ENXIO; 234 235 return 0; 236 } 237 238 static int 239 mdclose(dev_t dev, int flag, int fmt, struct lwp *l) 240 { 241 242 return 0; 243 } 244 245 static int 246 mdread(dev_t dev, struct uio *uio, int flags) 247 { 248 struct md_softc *sc; 249 250 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 251 252 if (sc->sc_type == MD_UNCONFIGURED) 253 return ENXIO; 254 255 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 256 } 257 258 static int 259 mdwrite(dev_t dev, struct uio *uio, int flags) 260 { 261 struct md_softc *sc; 262 263 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 264 265 if (sc->sc_type == MD_UNCONFIGURED) 266 return ENXIO; 267 268 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 269 } 270 271 /* 272 * Handle I/O requests, either directly, or 273 * by passing them to the server process. 274 */ 275 static void 276 mdstrategy(struct buf *bp) 277 { 278 struct md_softc *sc; 279 void * addr; 280 size_t off, xfer; 281 282 sc = device_lookup_private(&md_cd, MD_UNIT(bp->b_dev)); 283 284 if (sc->sc_type == MD_UNCONFIGURED) { 285 bp->b_error = ENXIO; 286 goto done; 287 } 288 289 switch (sc->sc_type) { 290 #if MEMORY_DISK_SERVER 291 case MD_UMEM_SERVER: 292 /* Just add this job to the server's queue. */ 293 BUFQ_PUT(sc->sc_buflist, bp); 294 wakeup((void *)sc); 295 /* see md_server_loop() */ 296 /* no biodone in this case */ 297 return; 298 #endif /* MEMORY_DISK_SERVER */ 299 300 case MD_KMEM_FIXED: 301 case MD_KMEM_ALLOCATED: 302 /* These are in kernel space. Access directly. */ 303 bp->b_resid = bp->b_bcount; 304 off = (bp->b_blkno << DEV_BSHIFT); 305 if (off >= sc->sc_size) { 306 if (bp->b_flags & B_READ) 307 break; /* EOF */ 308 goto set_eio; 309 } 310 xfer = bp->b_resid; 311 if (xfer > (sc->sc_size - off)) 312 xfer = (sc->sc_size - off); 313 addr = (char *)sc->sc_addr + off; 314 if (bp->b_flags & B_READ) 315 memcpy(bp->b_data, addr, xfer); 316 else 317 memcpy(addr, bp->b_data, xfer); 318 bp->b_resid -= xfer; 319 break; 320 321 default: 322 bp->b_resid = bp->b_bcount; 323 set_eio: 324 bp->b_error = EIO; 325 break; 326 } 327 done: 328 biodone(bp); 329 } 330 331 static int 332 mdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 333 { 334 struct md_softc *sc; 335 struct md_conf *umd; 336 337 sc = device_lookup_private(&md_cd, MD_UNIT(dev)); 338 339 /* If this is not the raw partition, punt! */ 340 if (DISKPART(dev) != RAW_PART) 341 return ENOTTY; 342 343 umd = (struct md_conf *)data; 344 switch (cmd) { 345 case MD_GETCONF: 346 *umd = sc->sc_md; 347 return 0; 348 349 case MD_SETCONF: 350 /* Can only set it once. */ 351 if (sc->sc_type != MD_UNCONFIGURED) 352 break; 353 switch (umd->md_type) { 354 case MD_KMEM_ALLOCATED: 355 return md_ioctl_kalloc(sc, umd, l); 356 #if MEMORY_DISK_SERVER 357 case MD_UMEM_SERVER: 358 return md_ioctl_server(sc, umd, l); 359 #endif /* MEMORY_DISK_SERVER */ 360 default: 361 break; 362 } 363 break; 364 } 365 return EINVAL; 366 } 367 368 /* 369 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 370 * Just allocate some kernel memory and return. 371 */ 372 static int 373 md_ioctl_kalloc(struct md_softc *sc, struct md_conf *umd, 374 struct lwp *l) 375 { 376 vaddr_t addr; 377 vsize_t size; 378 379 /* Sanity check the size. */ 380 size = umd->md_size; 381 addr = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); 382 if (!addr) 383 return ENOMEM; 384 385 /* This unit is now configured. */ 386 sc->sc_addr = (void *)addr; /* kernel space */ 387 sc->sc_size = (size_t)size; 388 sc->sc_type = MD_KMEM_ALLOCATED; 389 return 0; 390 } 391 392 #if MEMORY_DISK_SERVER 393 394 /* 395 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 396 * Set config, then become the I/O server for this unit. 397 */ 398 static int 399 md_ioctl_server(struct md_softc *sc, struct md_conf *umd, 400 struct lwp *l) 401 { 402 vaddr_t end; 403 int error; 404 405 /* Sanity check addr, size. */ 406 end = (vaddr_t) ((char *)umd->md_addr + umd->md_size); 407 408 if ((end >= VM_MAXUSER_ADDRESS) || 409 (end < ((vaddr_t) umd->md_addr)) ) 410 return EINVAL; 411 412 /* This unit is now configured. */ 413 sc->sc_addr = umd->md_addr; /* user space */ 414 sc->sc_size = umd->md_size; 415 sc->sc_type = MD_UMEM_SERVER; 416 417 /* Become the server daemon */ 418 error = md_server_loop(sc); 419 420 /* This server is now going away! */ 421 sc->sc_type = MD_UNCONFIGURED; 422 sc->sc_addr = 0; 423 sc->sc_size = 0; 424 425 return (error); 426 } 427 428 static int md_sleep_pri = PWAIT | PCATCH; 429 430 static int 431 md_server_loop(struct md_softc *sc) 432 { 433 struct buf *bp; 434 void *addr; /* user space address */ 435 size_t off; /* offset into "device" */ 436 size_t xfer; /* amount to transfer */ 437 int error; 438 439 for (;;) { 440 /* Wait for some work to arrive. */ 441 while ((bp = BUFQ_GET(sc->sc_buflist)) == NULL) { 442 error = tsleep((void *)sc, md_sleep_pri, "md_idle", 0); 443 if (error) 444 return error; 445 } 446 447 /* Do the transfer to/from user space. */ 448 error = 0; 449 bp->b_resid = bp->b_bcount; 450 off = (bp->b_blkno << DEV_BSHIFT); 451 if (off >= sc->sc_size) { 452 if (bp->b_flags & B_READ) 453 goto done; /* EOF (not an error) */ 454 error = EIO; 455 goto done; 456 } 457 xfer = bp->b_resid; 458 if (xfer > (sc->sc_size - off)) 459 xfer = (sc->sc_size - off); 460 addr = (char *)sc->sc_addr + off; 461 if (bp->b_flags & B_READ) 462 error = copyin(addr, bp->b_data, xfer); 463 else 464 error = copyout(bp->b_data, addr, xfer); 465 if (!error) 466 bp->b_resid -= xfer; 467 468 done: 469 if (error) { 470 bp->b_error = error; 471 } 472 biodone(bp); 473 } 474 } 475 #endif /* MEMORY_DISK_SERVER */ 476
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