md.c revision 1.19
1 /* $NetBSD: md.c,v 1.19 1999/02/07 09:34:59 jonathan 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 #include "opt_uvm.h" 50 51 #include <sys/param.h> 52 #include <sys/kernel.h> 53 #include <sys/malloc.h> 54 #include <sys/systm.h> 55 #include <sys/buf.h> 56 #include <sys/device.h> 57 #include <sys/disk.h> 58 #include <sys/proc.h> 59 #include <sys/conf.h> 60 #include <sys/disklabel.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 disk_attach(&sc->sc_dkdev); 177 } 178 179 /* 180 * operational routines: 181 * open, close, read, write, strategy, 182 * ioctl, dump, size 183 */ 184 185 #if MEMORY_DISK_SERVER 186 static int md_server_loop __P((struct md_softc *sc)); 187 static int md_ioctl_server __P((struct md_softc *sc, 188 struct md_conf *umd, struct proc *proc)); 189 #endif 190 static int md_ioctl_kalloc __P((struct md_softc *sc, 191 struct md_conf *umd, struct proc *proc)); 192 193 dev_type_open(mdopen); 194 dev_type_close(mdclose); 195 dev_type_read(mdread); 196 dev_type_write(mdwrite); 197 dev_type_ioctl(mdioctl); 198 dev_type_size(mdsize); 199 dev_type_dump(mddump); 200 201 int mddump(dev, blkno, va, size) 202 dev_t dev; 203 daddr_t blkno; 204 caddr_t va; 205 size_t size; 206 { 207 return ENODEV; 208 } 209 210 int mdsize(dev_t dev) 211 { 212 int unit; 213 struct md_softc *sc; 214 215 /* Disallow control units. */ 216 unit = DISKUNIT(dev); 217 if (unit >= ramdisk_ndevs) 218 return 0; 219 sc = ramdisk_devs[unit]; 220 if (sc == NULL) 221 return 0; 222 223 if (sc->sc_type == MD_UNCONFIGURED) 224 return 0; 225 226 return (sc->sc_size >> DEV_BSHIFT); 227 } 228 229 int 230 mdopen(dev, flag, fmt, proc) 231 dev_t dev; 232 int flag, fmt; 233 struct proc *proc; 234 { 235 int md, unit; 236 struct md_softc *sc; 237 238 md = DISKUNIT(dev); 239 unit = MD_UNIT(md); 240 if (unit >= ramdisk_ndevs) 241 return ENXIO; 242 sc = ramdisk_devs[unit]; 243 if (sc == NULL) 244 return ENXIO; 245 246 /* 247 * The control device is not exclusive, and can 248 * open uninitialized units (so you can setconf). 249 */ 250 if (MD_IS_CTRL(md)) 251 return 0; 252 253 #ifdef MEMORY_DISK_HOOKS 254 /* Call the open hook to allow loading the device. */ 255 md_open_hook(unit, &sc->sc_md); 256 #endif 257 258 /* 259 * This is a normal, "slave" device, so 260 * enforce initialized, exclusive open. 261 */ 262 if (sc->sc_type == MD_UNCONFIGURED) 263 return ENXIO; 264 if (sc->sc_flags & MD_ISOPEN) 265 return EBUSY; 266 267 return 0; 268 } 269 270 int 271 mdclose(dev, flag, fmt, proc) 272 dev_t dev; 273 int flag, fmt; 274 struct proc *proc; 275 { 276 int md, unit; 277 struct md_softc *sc; 278 279 md = DISKUNIT(dev); 280 unit = MD_UNIT(md); 281 sc = ramdisk_devs[unit]; 282 283 if (MD_IS_CTRL(md)) 284 return 0; 285 286 /* Normal device. */ 287 sc->sc_flags = 0; 288 289 return 0; 290 } 291 292 int 293 mdread(dev, uio, flags) 294 dev_t dev; 295 struct uio *uio; 296 int flags; 297 { 298 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio)); 299 } 300 301 int 302 mdwrite(dev, uio, flags) 303 dev_t dev; 304 struct uio *uio; 305 int flags; 306 { 307 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio)); 308 } 309 310 /* 311 * Handle I/O requests, either directly, or 312 * by passing them to the server process. 313 */ 314 void 315 mdstrategy(bp) 316 struct buf *bp; 317 { 318 int md, unit; 319 struct md_softc *sc; 320 caddr_t addr; 321 size_t off, xfer; 322 323 md = DISKUNIT(bp->b_dev); 324 unit = MD_UNIT(md); 325 sc = ramdisk_devs[unit]; 326 327 switch (sc->sc_type) { 328 #if MEMORY_DISK_SERVER 329 case MD_UMEM_SERVER: 330 /* Just add this job to the server's queue. */ 331 bp->b_actf = sc->sc_buflist; 332 sc->sc_buflist = bp; 333 if (bp->b_actf == NULL) { 334 /* server queue was empty. */ 335 wakeup((caddr_t)sc); 336 /* see md_server_loop() */ 337 } 338 /* no biodone in this case */ 339 return; 340 #endif /* MEMORY_DISK_SERVER */ 341 342 case MD_KMEM_FIXED: 343 case MD_KMEM_ALLOCATED: 344 /* These are in kernel space. Access directly. */ 345 bp->b_resid = bp->b_bcount; 346 off = (bp->b_blkno << DEV_BSHIFT); 347 if (off >= sc->sc_size) { 348 if (bp->b_flags & B_READ) 349 break; /* EOF */ 350 goto set_eio; 351 } 352 xfer = bp->b_resid; 353 if (xfer > (sc->sc_size - off)) 354 xfer = (sc->sc_size - off); 355 addr = sc->sc_addr + off; 356 if (bp->b_flags & B_READ) 357 bcopy(addr, bp->b_data, xfer); 358 else 359 bcopy(bp->b_data, addr, xfer); 360 bp->b_resid -= xfer; 361 break; 362 363 default: 364 bp->b_resid = bp->b_bcount; 365 set_eio: 366 bp->b_error = EIO; 367 bp->b_flags |= B_ERROR; 368 break; 369 } 370 biodone(bp); 371 } 372 373 int 374 mdioctl(dev, cmd, data, flag, proc) 375 dev_t dev; 376 u_long cmd; 377 int flag; 378 caddr_t data; 379 struct proc *proc; 380 { 381 int md, unit; 382 struct md_softc *sc; 383 struct md_conf *umd; 384 385 md = DISKUNIT(dev); 386 unit = MD_UNIT(md); 387 sc = ramdisk_devs[unit]; 388 389 /* If this is not the control device, punt! */ 390 if (MD_IS_CTRL(md) == 0) 391 return ENOTTY; 392 393 umd = (struct md_conf *)data; 394 switch (cmd) { 395 case MD_GETCONF: 396 *umd = sc->sc_md; 397 return 0; 398 399 case MD_SETCONF: 400 /* Can only set it once. */ 401 if (sc->sc_type != MD_UNCONFIGURED) 402 break; 403 switch (umd->md_type) { 404 case MD_KMEM_ALLOCATED: 405 return md_ioctl_kalloc(sc, umd, proc); 406 #if MEMORY_DISK_SERVER 407 case MD_UMEM_SERVER: 408 return md_ioctl_server(sc, umd, proc); 409 #endif 410 default: 411 break; 412 } 413 break; 414 } 415 return EINVAL; 416 } 417 418 /* 419 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED) 420 * Just allocate some kernel memory and return. 421 */ 422 static int 423 md_ioctl_kalloc(sc, umd, proc) 424 struct md_softc *sc; 425 struct md_conf *umd; 426 struct proc *proc; 427 { 428 vaddr_t addr; 429 vsize_t size; 430 431 /* Sanity check the size. */ 432 size = umd->md_size; 433 #if defined(UVM) 434 addr = uvm_km_zalloc(kernel_map, size); 435 #else 436 addr = kmem_alloc(kernel_map, size); 437 #endif 438 if (!addr) 439 return ENOMEM; 440 441 /* This unit is now configured. */ 442 sc->sc_addr = (caddr_t)addr; /* kernel space */ 443 sc->sc_size = (size_t)size; 444 sc->sc_type = MD_KMEM_ALLOCATED; 445 return 0; 446 } 447 448 #if MEMORY_DISK_SERVER 449 450 /* 451 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER) 452 * Set config, then become the I/O server for this unit. 453 */ 454 static int 455 md_ioctl_server(sc, umd, proc) 456 struct md_softc *sc; 457 struct md_conf *umd; 458 struct proc *proc; 459 { 460 vaddr_t end; 461 int error; 462 463 /* Sanity check addr, size. */ 464 end = (vaddr_t) (umd->md_addr + umd->md_size); 465 466 if ((end >= VM_MAXUSER_ADDRESS) || 467 (end < ((vaddr_t) umd->md_addr)) ) 468 return EINVAL; 469 470 /* This unit is now configured. */ 471 sc->sc_addr = umd->md_addr; /* user space */ 472 sc->sc_size = umd->md_size; 473 sc->sc_type = MD_UMEM_SERVER; 474 475 /* Become the server daemon */ 476 error = md_server_loop(sc); 477 478 /* This server is now going away! */ 479 sc->sc_type = MD_UNCONFIGURED; 480 sc->sc_addr = 0; 481 sc->sc_size = 0; 482 483 return (error); 484 } 485 486 int md_sleep_pri = PWAIT | PCATCH; 487 488 static int 489 md_server_loop(sc) 490 struct md_softc *sc; 491 { 492 struct buf *bp; 493 caddr_t addr; /* user space address */ 494 size_t off; /* offset into "device" */ 495 size_t xfer; /* amount to transfer */ 496 int error; 497 498 for (;;) { 499 /* Wait for some work to arrive. */ 500 while (sc->sc_buflist == NULL) { 501 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0); 502 if (error) 503 return error; 504 } 505 506 /* Unlink buf from head of list. */ 507 bp = sc->sc_buflist; 508 sc->sc_buflist = bp->b_actf; 509 bp->b_actf = NULL; 510 511 /* Do the transfer to/from user space. */ 512 error = 0; 513 bp->b_resid = bp->b_bcount; 514 off = (bp->b_blkno << DEV_BSHIFT); 515 if (off >= sc->sc_size) { 516 if (bp->b_flags & B_READ) 517 goto done; /* EOF (not an error) */ 518 error = EIO; 519 goto done; 520 } 521 xfer = bp->b_resid; 522 if (xfer > (sc->sc_size - off)) 523 xfer = (sc->sc_size - off); 524 addr = sc->sc_addr + off; 525 if (bp->b_flags & B_READ) 526 error = copyin(addr, bp->b_data, xfer); 527 else 528 error = copyout(bp->b_data, addr, xfer); 529 if (!error) 530 bp->b_resid -= xfer; 531 532 done: 533 if (error) { 534 bp->b_error = error; 535 bp->b_flags |= B_ERROR; 536 } 537 biodone(bp); 538 } 539 } 540 #endif /* MEMORY_DISK_SERVER */ 541
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