md.c revision 1.11
1 /* $NetBSD: md.c,v 1.11 1996/12/28 23:09:26 pk 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 ramdisk.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/param.h> 49 #include <sys/kernel.h> 50 #include <sys/malloc.h> 51 #include <sys/systm.h> 52 #include <sys/buf.h> 53 #include <sys/device.h> 54 #include <sys/disk.h> 55 #include <sys/proc.h> 56 #include <sys/conf.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_kern.h> 60 #include <vm/vm_extern.h> 61 62 #include <dev/md.h> 63 64 /* 65 * By default, include the user-space functionality. 66 * Use `options MEMORY_DISK_SERVER=0' to turn it off. 67 */ 68 #ifndef MEMORY_DISK_SERVER 69 #define MEMORY_DISK_SERVER 1 70 #endif 71 72 /* 73 * XXX: the "control" unit is (base unit + 16). 74 * We should just use the cdev as the "control", but 75 * that interferes with the security stuff preventing 76 * simulatneous use of raw and block devices. 77 * 78 * XXX Assumption: 16 memory-disks are enough! 79 */ 80 #define MD_MAX_UNITS 0x10 81 #define MD_IS_CTRL(unit) (unit & 0x10) 82 #define MD_UNIT(unit) (unit & 0xF) 83 84 /* autoconfig stuff... */ 85 86 struct md_softc { 87 struct device sc_dev; /* REQUIRED first entry */ 88 struct disk sc_dkdev; /* hook for generic disk handling */ 89 struct md_conf sc_md; 90 struct buf *sc_buflist; 91 int sc_flags; 92 }; 93 /* shorthand for fields in sc_md: */ 94 #define sc_addr sc_md.md_addr 95 #define sc_size sc_md.md_size 96 #define sc_type sc_md.md_type 97 /* flags */ 98 #define MD_ISOPEN 0x01 99 #define MD_SERVED 0x02 100 101 void mdattach __P((int)); 102 static void md_attach __P((struct device *, struct device *, void *)); 103 104 /* 105 * Some ports (like i386) use a swapgeneric that wants to 106 * snoop around in this md_cd structure. It is preserved 107 * (for now) to remain compatible with such practice. 108 * XXX - that practice is questionable... 109 */ 110 struct cfdriver md_cd = { 111 NULL, "md", DV_DULL, NULL, 0 112 }; 113 114 void mdstrategy __P((struct buf *bp)); 115 struct dkdriver mddkdriver = { mdstrategy }; 116 117 static int ramdisk_ndevs; 118 static void *ramdisk_devs[MD_MAX_UNITS]; 119 120 /* 121 * This is called if we are configured as a pseudo-device 122 */ 123 void 124 mdattach(n) 125 int n; 126 { 127 struct md_softc *sc; 128 int i; 129 130 #ifdef DIAGNOSTIC 131 if (ramdisk_ndevs) { 132 printf("ramdisk: multiple attach calls?\n"); 133 return; 134 } 135 #endif 136 137 /* XXX: Are we supposed to provide a default? */ 138 if (n <= 1) 139 n = 1; 140 if (n > MD_MAX_UNITS) 141 n = MD_MAX_UNITS; 142 ramdisk_ndevs = n; 143 144 /* XXX: Fake-up md_cd (see above) */ 145 md_cd.cd_ndevs = ramdisk_ndevs; 146 md_cd.cd_devs = ramdisk_devs; 147 148 /* Attach as if by autoconfig. */ 149 for (i = 0; i < n; i++) { 150 151 sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK); 152 if (!sc) { 153 printf("ramdisk: malloc for attach failed!\n"); 154 return; 155 } 156 bzero((caddr_t)sc, sizeof(*sc)); 157 ramdisk_devs[i] = sc; 158 sc->sc_dev.dv_unit = i; 159 sprintf(sc->sc_dev.dv_xname, "md%d", i); 160 md_attach(NULL, &sc->sc_dev, NULL); 161 } 162 } 163 164 static void 165 md_attach(parent, self, aux) 166 struct device *parent, *self; 167 void *aux; 168 { 169 struct md_softc *sc = (struct md_softc *)self; 170 171 /* XXX - Could accept aux info here to set the config. */ 172 #ifdef MEMORY_DISK_HOOKS 173 /* 174 * This external function might setup a pre-loaded disk. 175 * All it would need to do is setup the md_conf struct. 176 * See sys/arch/sun3/dev/md_root.c for an example. 177 */ 178 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md); 179 #endif 180 181 /* 182 * Initialize and attach the disk structure. 183 */ 184 sc->sc_dkdev.dk_driver = &mddkdriver; 185 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 186 disk_attach(&sc->sc_dkdev); 187 } 188 189 /* 190 * operational routines: 191 * open, close, read, write, strategy, 192 * ioctl, dump, size 193 */ 194 195 #if MEMORY_DISK_SERVER 196 static int md_server_loop __P((struct md_softc *sc)); 197 static int md_ioctl_server __P((struct md_softc *sc, 198 struct md_conf *umd, struct proc *proc)); 199 #endif 200 static int md_ioctl_kalloc __P((struct md_softc *sc, 201 struct md_conf *umd, struct proc *proc)); 202 203 dev_type_open(mdopen); 204 dev_type_close(mdclose); 205 dev_type_read(mdread); 206 dev_type_write(mdwrite); 207 dev_type_ioctl(mdioctl); 208 dev_type_size(mdsize); 209 dev_type_dump(mddump); 210 211 int mddump(dev, blkno, va, size) 212 dev_t dev; 213 daddr_t blkno; 214 caddr_t va; 215 size_t size; 216 { 217 return ENODEV; 218 } 219 220 int mdsize(dev_t dev) 221 { 222 int unit; 223 struct md_softc *sc; 224 225 /* Disallow control units. */ 226 unit = minor(dev); 227 if (unit >= ramdisk_ndevs) 228 return 0; 229 sc = ramdisk_devs[unit]; 230 if (sc == NULL) 231 return 0; 232 233 if (sc->sc_type == MD_UNCONFIGURED) 234 return 0; 235 236 return (sc->sc_size >> DEV_BSHIFT); 237 } 238 239 int 240 mdopen(dev, flag, fmt, proc) 241 dev_t dev; 242 int flag, fmt; 243 struct proc *proc; 244 { 245 int md, unit; 246 struct md_softc *sc; 247 248 md = minor(dev); 249 unit = MD_UNIT(md); 250 if (unit >= ramdisk_ndevs) 251 return ENXIO; 252 sc = ramdisk_devs[unit]; 253 if (sc == NULL) 254 return ENXIO; 255 256 /* 257 * The control device is not exclusive, and can 258 * open uninitialized units (so you can setconf). 259 */ 260 if (MD_IS_CTRL(md)) 261 return 0; 262 263 #ifdef MEMORY_DISK_HOOKS 264 /* Call the open hook to allow loading the device. */ 265 md_open_hook(unit, &sc->sc_md); 266 #endif 267 268 /* 269 * This is a normal, "slave" device, so 270 * enforce initialized, exclusive open. 271 */ 272 if (sc->sc_type == MD_UNCONFIGURED) 273 return ENXIO; 274 if (sc->sc_flags & MD_ISOPEN) 275 return EBUSY; 276 277 return 0; 278 } 279 280 int 281 mdclose(dev, flag, fmt, proc) 282 dev_t dev; 283 int flag, fmt; 284 struct proc *proc; 285 { 286 int md, unit; 287 struct md_softc *sc; 288 289 md = minor(dev); 290 unit = MD_UNIT(md); 291 sc = ramdisk_devs[unit]; 292 293 if (MD_IS_CTRL(md)) 294 return 0; 295 296 /* Normal device. */ 297 sc->sc_flags = 0; 298 299 return 0; 300 } 301 302 int 303 mdread(dev, uio, flags) 304 dev_t dev; 305 struct uio *uio; 306 int flags; 307 { 308 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 309 } 310 311 int 312 mdwrite(dev, uio, flags) 313 dev_t dev; 314 struct uio *uio; 315 int flags; 316 { 317 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 318 } 319 320 /* 321 * Handle I/O requests, either directly, or 322 * by passing them to the server process. 323 */ 324 void 325 mdstrategy(bp) 326 struct buf *bp; 327 { 328 int md, unit; 329 struct md_softc *sc; 330 caddr_t addr; 331 size_t off, xfer; 332 333 md = minor(bp->b_dev); 334 unit = MD_UNIT(md); 335 sc = ramdisk_devs[unit]; 336 337 switch (sc->sc_type) { 338 #if MEMORY_DISK_SERVER 339 case MD_UMEM_SERVER: 340 /* Just add this job to the server's queue. */ 341 bp->b_actf = sc->sc_buflist; 342 sc->sc_buflist = bp; 343 if (bp->b_actf == NULL) { 344 /* server queue was empty. */ 345 wakeup((caddr_t)sc); 346 /* see md_server_loop() */ 347 } 348 /* no biodone in this case */ 349 return; 350 #endif /* MEMORY_DISK_SERVER */ 351 352 case MD_KMEM_FIXED: 353 case MD_KMEM_ALLOCATED: 354 /* These are in kernel space. Access directly. */ 355 bp->b_resid = bp->b_bcount; 356 off = (bp->b_blkno << DEV_BSHIFT); 357 if (off >= sc->sc_size) { 358 if (bp->b_flags & B_READ) 359 break; /* EOF */ 360 goto set_eio; 361 } 362 xfer = bp->b_resid; 363 if (xfer > (sc->sc_size - off)) 364 xfer = (sc->sc_size - off); 365 addr = sc->sc_addr + off; 366 if (bp->b_flags & B_READ) 367 bcopy(addr, bp->b_data, xfer); 368 else 369 bcopy(bp->b_data, addr, xfer); 370 bp->b_resid -= xfer; 371 break; 372 373 default: 374 bp->b_resid = bp->b_bcount; 375 set_eio: 376 bp->b_error = EIO; 377 bp->b_flags |= B_ERROR; 378 break; 379 } 380 biodone(bp); 381 } 382 383 int 384 mdioctl(dev, cmd, data, flag, proc) 385 dev_t dev; 386 u_long cmd; 387 int flag; 388 caddr_t data; 389 struct proc *proc; 390 { 391 int md, unit; 392 struct md_softc *sc; 393 struct md_conf *umd; 394 395 md = minor(dev); 396 unit = MD_UNIT(md); 397 sc = ramdisk_devs[unit]; 398 399 /* If this is not the control device, punt! */ 400 if (MD_IS_CTRL(md) == 0) 401 return ENOTTY; 402 403 umd = (struct md_conf *)data; 404 switch (cmd) { 405 case MD_GETCONF: 406 *umd = sc->sc_md; 407 return 0; 408 409 case MD_SETCONF: 410 /* Can only set it once. */ 411 if (sc->sc_type != MD_UNCONFIGURED) 412 break; 413 switch (umd->md_type) { 414 case MD_KMEM_ALLOCATED: 415 return md_ioctl_kalloc(sc, umd, proc); 416 #if MEMORY_DISK_SERVER 417 case MD_UMEM_SERVER: 418 return md_ioctl_server(sc, umd, proc); 419 #endif 420 default: 421 break; 422 } 423 break; 424 } 425 return EINVAL; 426 } 427 428 /* 429 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 430 * Just allocate some kernel memory and return. 431 */ 432 static int 433 md_ioctl_kalloc(sc, umd, proc) 434 struct md_softc *sc; 435 struct md_conf *umd; 436 struct proc *proc; 437 { 438 vm_offset_t addr; 439 vm_size_t size; 440 441 /* Sanity check the size. */ 442 size = umd->md_size; 443 addr = kmem_alloc(kernel_map, size); 444 if (!addr) 445 return ENOMEM; 446 447 /* This unit is now configured. */ 448 sc->sc_addr = (caddr_t)addr; /* kernel space */ 449 sc->sc_size = (size_t)size; 450 sc->sc_type = MD_KMEM_ALLOCATED; 451 return 0; 452 } 453 454 #if MEMORY_DISK_SERVER 455 456 /* 457 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 458 * Set config, then become the I/O server for this unit. 459 */ 460 static int 461 md_ioctl_server(sc, umd, proc) 462 struct md_softc *sc; 463 struct md_conf *umd; 464 struct proc *proc; 465 { 466 vm_offset_t end; 467 int error; 468 469 /* Sanity check addr, size. */ 470 end = (vm_offset_t) (umd->md_addr + umd->md_size); 471 472 if ((end >= VM_MAXUSER_ADDRESS) || 473 (end < ((vm_offset_t) umd->md_addr)) ) 474 return EINVAL; 475 476 /* This unit is now configured. */ 477 sc->sc_addr = umd->md_addr; /* user space */ 478 sc->sc_size = umd->md_size; 479 sc->sc_type = MD_UMEM_SERVER; 480 481 /* Become the server daemon */ 482 error = md_server_loop(sc); 483 484 /* This server is now going away! */ 485 sc->sc_type = MD_UNCONFIGURED; 486 sc->sc_addr = 0; 487 sc->sc_size = 0; 488 489 return (error); 490 } 491 492 int md_sleep_pri = PWAIT | PCATCH; 493 494 static int 495 md_server_loop(sc) 496 struct md_softc *sc; 497 { 498 struct buf *bp; 499 caddr_t addr; /* user space address */ 500 size_t off; /* offset into "device" */ 501 size_t xfer; /* amount to transfer */ 502 int error; 503 504 for (;;) { 505 /* Wait for some work to arrive. */ 506 while (sc->sc_buflist == NULL) { 507 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 508 if (error) 509 return error; 510 } 511 512 /* Unlink buf from head of list. */ 513 bp = sc->sc_buflist; 514 sc->sc_buflist = bp->b_actf; 515 bp->b_actf = NULL; 516 517 /* Do the transfer to/from user space. */ 518 error = 0; 519 bp->b_resid = bp->b_bcount; 520 off = (bp->b_blkno << DEV_BSHIFT); 521 if (off >= sc->sc_size) { 522 if (bp->b_flags & B_READ) 523 goto done; /* EOF (not an error) */ 524 error = EIO; 525 goto done; 526 } 527 xfer = bp->b_resid; 528 if (xfer > (sc->sc_size - off)) 529 xfer = (sc->sc_size - off); 530 addr = sc->sc_addr + off; 531 if (bp->b_flags & B_READ) 532 error = copyin(addr, bp->b_data, xfer); 533 else 534 error = copyout(bp->b_data, addr, xfer); 535 if (!error) 536 bp->b_resid -= xfer; 537 538 done: 539 if (error) { 540 bp->b_error = error; 541 bp->b_flags |= B_ERROR; 542 } 543 biodone(bp); 544 } 545 } 546 #endif /* MEMORY_DISK_SERVER */ 547
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