md.c revision 1.20.14.1
1 /* $NetBSD: md.c,v 1.20.14.1 1999/12/21 23:19:52 wrstuden 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 "opt_md.h" 49 50 #include <sys/param.h> 51 #include <sys/kernel.h> 52 #include <sys/malloc.h> 53 #include <sys/systm.h> 54 #include <sys/buf.h> 55 #include <sys/device.h> 56 #include <sys/disk.h> 57 #include <sys/proc.h> 58 #include <sys/conf.h> 59 #include <sys/disklabel.h> 60 #include <sys/dkio.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_kern.h> 64 #include <vm/vm_extern.h> 65 66 #include <dev/md.h> 67 68 /* 69 * By default, include the user-space functionality. 70 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 71 */ 72 #ifndef MEMORY_DISK_SERVER 73 #define MEMORY_DISK_SERVER 1 74 #endif 75 76 /* 77 * XXX: the "control" unit is (base unit + 16). 78 * We should just use the cdev as the "control", but 79 * that interferes with the security stuff preventing 80 * simulatneous use of raw and block devices. 81 * 82 * XXX Assumption: 16 memory-disks are enough! 83 */ 84 #define MD_MAX_UNITS 0x10 85 #define MD_IS_CTRL(unit) (unit & 0x10) 86 #define MD_UNIT(unit) (unit & 0xF) 87 88 /* autoconfig stuff... */ 89 90 struct md_softc { 91 struct device sc_dev; /* REQUIRED first entry */ 92 struct disk sc_dkdev; /* hook for generic disk handling */ 93 struct md_conf sc_md; 94 struct buf *sc_buflist; 95 int sc_flags; 96 }; 97 /* shorthand for fields in sc_md: */ 98 #define sc_addr sc_md.md_addr 99 #define sc_size sc_md.md_size 100 #define sc_type sc_md.md_type 101 /* flags */ 102 #define MD_ISOPEN 0x01 103 #define MD_SERVED 0x02 104 105 void mdattach __P((int)); 106 static void md_attach __P((struct device *, struct device *, void *)); 107 108 void mdstrategy __P((struct buf *bp)); 109 struct dkdriver mddkdriver = { mdstrategy }; 110 111 static int ramdisk_ndevs; 112 static void *ramdisk_devs[MD_MAX_UNITS]; 113 114 /* 115 * This is called if we are configured as a pseudo-device 116 */ 117 void 118 mdattach(n) 119 int n; 120 { 121 struct md_softc *sc; 122 int i; 123 124 #ifdef DIAGNOSTIC 125 if (ramdisk_ndevs) { 126 printf("ramdisk: multiple attach calls?\n"); 127 return; 128 } 129 #endif 130 131 /* XXX: Are we supposed to provide a default? */ 132 if (n <= 1) 133 n = 1; 134 if (n > MD_MAX_UNITS) 135 n = MD_MAX_UNITS; 136 ramdisk_ndevs = n; 137 138 /* Attach as if by autoconfig. */ 139 for (i = 0; i < n; i++) { 140 141 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT); 142 if (!sc) { 143 printf("ramdisk: malloc for attach failed!\n"); 144 return; 145 } 146 bzero((caddr_t)sc, sizeof(*sc)); 147 ramdisk_devs[i] = sc; 148 sc->sc_dev.dv_unit = i; 149 sprintf(sc->sc_dev.dv_xname, "md%d", i); 150 md_attach(NULL, &sc->sc_dev, NULL); 151 } 152 } 153 154 static void 155 md_attach(parent, self, aux) 156 struct device *parent, *self; 157 void *aux; 158 { 159 struct md_softc *sc = (struct md_softc *)self; 160 161 /* XXX - Could accept aux info here to set the config. */ 162 #ifdef MEMORY_DISK_HOOKS 163 /* 164 * This external function might setup a pre-loaded disk. 165 * All it would need to do is setup the md_conf struct. 166 * See sys/arch/sun3/dev/md_root.c for an example. 167 */ 168 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 169 #endif 170 171 /* 172 * Initialize and attach the disk structure. 173 */ 174 sc->sc_dkdev.dk_driver = &mddkdriver; 175 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 176 sc->sc_dkdev.dk_byteshift = DEF_BSHIFT; 177 disk_attach(&sc->sc_dkdev); 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 __P((struct md_softc *sc)); 188 static int md_ioctl_server __P((struct md_softc *sc, 189 struct md_conf *umd, struct proc *proc)); 190 #endif 191 static int md_ioctl_kalloc __P((struct md_softc *sc, 192 struct md_conf *umd, struct proc *proc)); 193 194 dev_type_open(mdopen); 195 dev_type_close(mdclose); 196 dev_type_read(mdread); 197 dev_type_write(mdwrite); 198 dev_type_ioctl(mdioctl); 199 dev_type_size(mdsize); 200 dev_type_dump(mddump); 201 202 int mddump(dev, blkno, va, size) 203 dev_t dev; 204 daddr_t blkno; 205 caddr_t va; 206 size_t size; 207 { 208 return ENODEV; 209 } 210 211 int mdsize(dev_t dev) 212 { 213 int unit; 214 struct md_softc *sc; 215 216 /* Disallow control units. */ 217 unit = DISKUNIT(dev); 218 if (unit >= ramdisk_ndevs) 219 return 0; 220 sc = ramdisk_devs[unit]; 221 if (sc == NULL) 222 return 0; 223 224 if (sc->sc_type == MD_UNCONFIGURED) 225 return 0; 226 227 return (sc->sc_size >> DEF_BSHIFT); 228 } 229 230 int 231 mdopen(dev, flag, fmt, proc) 232 dev_t dev; 233 int flag, fmt; 234 struct proc *proc; 235 { 236 int md, unit; 237 struct md_softc *sc; 238 239 md = DISKUNIT(dev); 240 unit = MD_UNIT(md); 241 if (unit >= ramdisk_ndevs) 242 return ENXIO; 243 sc = ramdisk_devs[unit]; 244 if (sc == NULL) 245 return ENXIO; 246 247 /* 248 * The control device is not exclusive, and can 249 * open uninitialized units (so you can setconf). 250 */ 251 if (MD_IS_CTRL(md)) 252 return 0; 253 254 #ifdef MEMORY_DISK_HOOKS 255 /* Call the open hook to allow loading the device. */ 256 md_open_hook(unit, &sc->sc_md); 257 #endif 258 259 /* 260 * This is a normal, "slave" device, so 261 * enforce initialized, exclusive open. 262 */ 263 if (sc->sc_type == MD_UNCONFIGURED) 264 return ENXIO; 265 if (sc->sc_flags & MD_ISOPEN) 266 return EBUSY; 267 268 return 0; 269 } 270 271 int 272 mdclose(dev, flag, fmt, proc) 273 dev_t dev; 274 int flag, fmt; 275 struct proc *proc; 276 { 277 int md, unit; 278 struct md_softc *sc; 279 280 md = DISKUNIT(dev); 281 unit = MD_UNIT(md); 282 sc = ramdisk_devs[unit]; 283 284 if (MD_IS_CTRL(md)) 285 return 0; 286 287 /* Normal device. */ 288 sc->sc_flags = 0; 289 290 return 0; 291 } 292 293 int 294 mdread(dev, uio, flags) 295 dev_t dev; 296 struct uio *uio; 297 int flags; 298 { 299 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio, 300 DEF_BSHIFT)); 301 } 302 303 int 304 mdwrite(dev, uio, flags) 305 dev_t dev; 306 struct uio *uio; 307 int flags; 308 { 309 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio, 310 DEF_BSHIFT)); 311 } 312 313 /* 314 * Handle I/O requests, either directly, or 315 * by passing them to the server process. 316 */ 317 void 318 mdstrategy(bp) 319 struct buf *bp; 320 { 321 int md, unit; 322 struct md_softc *sc; 323 caddr_t addr; 324 size_t off, xfer; 325 326 md = DISKUNIT(bp->b_dev); 327 unit = MD_UNIT(md); 328 sc = ramdisk_devs[unit]; 329 330 switch (sc->sc_type) { 331 #if MEMORY_DISK_SERVER 332 case MD_UMEM_SERVER: 333 /* Just add this job to the server's queue. */ 334 bp->b_actf = sc->sc_buflist; 335 sc->sc_buflist = bp; 336 if (bp->b_actf == NULL) { 337 /* server queue was empty. */ 338 wakeup((caddr_t)sc); 339 /* see md_server_loop() */ 340 } 341 /* no biodone in this case */ 342 return; 343 #endif /* MEMORY_DISK_SERVER */ 344 345 case MD_KMEM_FIXED: 346 case MD_KMEM_ALLOCATED: 347 /* These are in kernel space. Access directly. */ 348 bp->b_resid = bp->b_bcount; 349 off = (bp->b_blkno << sc->sc_dkdev.dk_byteshift); 350 if (off >= sc->sc_size) { 351 if (bp->b_flags & B_READ) 352 break; /* EOF */ 353 goto set_eio; 354 } 355 xfer = bp->b_resid; 356 if (xfer > (sc->sc_size - off)) 357 xfer = (sc->sc_size - off); 358 addr = sc->sc_addr + off; 359 if (bp->b_flags & B_READ) 360 bcopy(addr, bp->b_data, xfer); 361 else 362 bcopy(bp->b_data, addr, xfer); 363 bp->b_resid -= xfer; 364 break; 365 366 default: 367 bp->b_resid = bp->b_bcount; 368 set_eio: 369 bp->b_error = EIO; 370 bp->b_flags |= B_ERROR; 371 break; 372 } 373 biodone(bp); 374 } 375 376 int 377 mdioctl(dev, cmd, data, flag, proc) 378 dev_t dev; 379 u_long cmd; 380 int flag; 381 caddr_t data; 382 struct proc *proc; 383 { 384 int md, unit; 385 struct md_softc *sc; 386 struct md_conf *umd; 387 388 md = DISKUNIT(dev); 389 unit = MD_UNIT(md); 390 sc = ramdisk_devs[unit]; 391 392 /* If this is not the control device, punt! */ 393 if (MD_IS_CTRL(md) == 0) 394 return ENOTTY; 395 396 umd = (struct md_conf *)data; 397 switch (cmd) { 398 case MD_GETCONF: 399 *umd = sc->sc_md; 400 return 0; 401 402 case DIOCGBSHIFT: 403 *(int *)data = DEF_BSHIFT; 404 return 0; 405 406 case MD_SETCONF: 407 /* Can only set it once. */ 408 if (sc->sc_type != MD_UNCONFIGURED) 409 break; 410 switch (umd->md_type) { 411 case MD_KMEM_ALLOCATED: 412 return md_ioctl_kalloc(sc, umd, proc); 413 #if MEMORY_DISK_SERVER 414 case MD_UMEM_SERVER: 415 return md_ioctl_server(sc, umd, proc); 416 #endif 417 default: 418 break; 419 } 420 break; 421 } 422 return EINVAL; 423 } 424 425 /* 426 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 427 * Just allocate some kernel memory and return. 428 */ 429 static int 430 md_ioctl_kalloc(sc, umd, proc) 431 struct md_softc *sc; 432 struct md_conf *umd; 433 struct proc *proc; 434 { 435 vaddr_t addr; 436 vsize_t size; 437 438 /* Sanity check the size. */ 439 size = umd->md_size; 440 addr = uvm_km_zalloc(kernel_map, size); 441 if (!addr) 442 return ENOMEM; 443 444 /* This unit is now configured. */ 445 sc->sc_addr = (caddr_t)addr; /* kernel space */ 446 sc->sc_size = (size_t)size; 447 sc->sc_type = MD_KMEM_ALLOCATED; 448 return 0; 449 } 450 451 #if MEMORY_DISK_SERVER 452 453 /* 454 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 455 * Set config, then become the I/O server for this unit. 456 */ 457 static int 458 md_ioctl_server(sc, umd, proc) 459 struct md_softc *sc; 460 struct md_conf *umd; 461 struct proc *proc; 462 { 463 vaddr_t end; 464 int error; 465 466 /* Sanity check addr, size. */ 467 end = (vaddr_t) (umd->md_addr + umd->md_size); 468 469 if ((end >= VM_MAXUSER_ADDRESS) || 470 (end < ((vaddr_t) umd->md_addr)) ) 471 return EINVAL; 472 473 /* This unit is now configured. */ 474 sc->sc_addr = umd->md_addr; /* user space */ 475 sc->sc_size = umd->md_size; 476 sc->sc_type = MD_UMEM_SERVER; 477 478 /* Become the server daemon */ 479 error = md_server_loop(sc); 480 481 /* This server is now going away! */ 482 sc->sc_type = MD_UNCONFIGURED; 483 sc->sc_addr = 0; 484 sc->sc_size = 0; 485 486 return (error); 487 } 488 489 int md_sleep_pri = PWAIT | PCATCH; 490 491 static int 492 md_server_loop(sc) 493 struct md_softc *sc; 494 { 495 struct buf *bp; 496 caddr_t addr; /* user space address */ 497 size_t off; /* offset into "device" */ 498 size_t xfer; /* amount to transfer */ 499 int error; 500 501 for (;;) { 502 /* Wait for some work to arrive. */ 503 while (sc->sc_buflist == NULL) { 504 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 505 if (error) 506 return error; 507 } 508 509 /* Unlink buf from head of list. */ 510 bp = sc->sc_buflist; 511 sc->sc_buflist = bp->b_actf; 512 bp->b_actf = NULL; 513 514 /* Do the transfer to/from user space. */ 515 error = 0; 516 bp->b_resid = bp->b_bcount; 517 off = (bp->b_blkno << sc->sc_dkdev.dk_byteshift); 518 if (off >= sc->sc_size) { 519 if (bp->b_flags & B_READ) 520 goto done; /* EOF (not an error) */ 521 error = EIO; 522 goto done; 523 } 524 xfer = bp->b_resid; 525 if (xfer > (sc->sc_size - off)) 526 xfer = (sc->sc_size - off); 527 addr = sc->sc_addr + off; 528 if (bp->b_flags & B_READ) 529 error = copyin(addr, bp->b_data, xfer); 530 else 531 error = copyout(bp->b_data, addr, xfer); 532 if (!error) 533 bp->b_resid -= xfer; 534 535 done: 536 if (error) { 537 bp->b_error = error; 538 bp->b_flags |= B_ERROR; 539 } 540 biodone(bp); 541 } 542 } 543 #endif /* MEMORY_DISK_SERVER */ 544
Indexes created Tue Sep 30 20:09:53 GMT 2025