md.c revision 1.7
1 /* $NetBSD: md.c,v 1.7 1996/03/22 23:02:02 gwr 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-puspose RAM-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 RAM" 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 56 #include <vm/vm.h> 57 #include <vm/vm_kern.h> 58 /* Don't want all those other VM headers... */ 59 extern vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t)); 60 61 #include <dev/ramdisk.h> 62 63 /* 64 * By default, include the user-space functionality. 65 * Use: option RAMDISK_SERVER=0 to turn it off. 66 */ 67 #ifndef RAMDISK_SERVER 68 #define RAMDISK_SERVER 1 69 #endif 70 71 /* 72 * XXX: the "control" unit is (base unit + 16). 73 * We should just use the cdev as the "control", but 74 * that interferes with the security stuff preventing 75 * simulatneous use of raw and block devices. 76 * 77 * XXX Assumption: 16 RAM-disks are enough! 78 */ 79 #define RD_MAX_UNITS 0x10 80 #define RD_IS_CTRL(unit) (unit & 0x10) 81 #define RD_UNIT(unit) (unit & 0xF) 82 83 /* autoconfig stuff... */ 84 85 struct rd_softc { 86 struct device sc_dev; /* REQUIRED first entry */ 87 struct disk sc_dkdev; /* hook for generic disk handling */ 88 struct rd_conf sc_rd; 89 struct buf *sc_buflist; 90 int sc_flags; 91 }; 92 /* shorthand for fields in sc_rd: */ 93 #define sc_addr sc_rd.rd_addr 94 #define sc_size sc_rd.rd_size 95 #define sc_type sc_rd.rd_type 96 /* flags */ 97 #define RD_ISOPEN 0x01 98 #define RD_SERVED 0x02 99 100 static void rd_attach __P((struct device *, struct device *, void *)); 101 102 /* 103 * Some ports (like i386) use a swapgeneric that wants to 104 * snoop around in this rd_cd structure. It is preserved 105 * (for now) to remain compatible with such practice. 106 * XXX - that practice is questionable... 107 */ 108 struct cfdriver rd_cd = { 109 NULL, "rd", DV_DULL, NULL, 0 110 }; 111 112 void rdstrategy __P((struct buf *bp)); 113 struct dkdriver rddkdriver = { rdstrategy }; 114 115 static int ramdisk_ndevs; 116 static void *ramdisk_devs[RD_MAX_UNITS]; 117 118 /* 119 * This is called if we are configured as a pseudo-device 120 */ 121 void 122 rdattach(n) 123 int n; 124 { 125 struct rd_softc *sc; 126 int i; 127 128 #ifdef DIAGNOSTIC 129 if (ramdisk_ndevs) { 130 printf("ramdisk: multiple attach calls?\n"); 131 return; 132 } 133 #endif 134 135 /* XXX: Are we supposed to provide a default? */ 136 if (n <= 1) 137 n = 1; 138 if (n > RD_MAX_UNITS) 139 n = RD_MAX_UNITS; 140 ramdisk_ndevs = n; 141 142 /* XXX: Fake-up rd_cd (see above) */ 143 rd_cd.cd_ndevs = ramdisk_ndevs; 144 rd_cd.cd_devs = ramdisk_devs; 145 146 /* Attach as if by autoconfig. */ 147 for (i = 0; i < n; i++) { 148 149 sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK); 150 if (!sc) { 151 printf("ramdisk: malloc for attach failed!\n"); 152 return; 153 } 154 bzero((caddr_t)sc, sizeof(*sc)); 155 ramdisk_devs[i] = sc; 156 sc->sc_dev.dv_unit = i; 157 sprintf(sc->sc_dev.dv_xname, "rd%d", i); 158 rd_attach(NULL, &sc->sc_dev, NULL); 159 } 160 } 161 162 static void 163 rd_attach(parent, self, aux) 164 struct device *parent, *self; 165 void *aux; 166 { 167 struct rd_softc *sc = (struct rd_softc *)self; 168 169 /* XXX - Could accept aux info here to set the config. */ 170 #ifdef RAMDISK_HOOKS 171 /* 172 * This external function might setup a pre-loaded disk. 173 * All it would need to do is setup the rd_conf struct. 174 * See sys/arch/sun3/dev/rd_root.c for an example. 175 */ 176 rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd); 177 #endif 178 179 /* 180 * Initialize and attach the disk structure. 181 */ 182 sc->sc_dkdev.dk_driver = &rddkdriver; 183 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 184 disk_attach(&sc->sc_dkdev); 185 } 186 187 /* 188 * operational routines: 189 * open, close, read, write, strategy, 190 * ioctl, dump, size 191 */ 192 193 #if RAMDISK_SERVER 194 static int rd_server_loop __P((struct rd_softc *sc)); 195 static int rd_ioctl_server __P((struct rd_softc *sc, 196 struct rd_conf *urd, struct proc *proc)); 197 #endif 198 199 int rddump(dev, blkno, va, size) 200 dev_t dev; 201 daddr_t blkno; 202 caddr_t va; 203 size_t size; 204 { 205 return ENODEV; 206 } 207 208 int rdsize(dev_t dev) 209 { 210 int unit; 211 struct rd_softc *sc; 212 213 /* Disallow control units. */ 214 unit = minor(dev); 215 if (unit >= ramdisk_ndevs) 216 return 0; 217 sc = ramdisk_devs[unit]; 218 if (sc == NULL) 219 return 0; 220 221 if (sc->sc_type == RD_UNCONFIGURED) 222 return 0; 223 224 return (sc->sc_size >> DEV_BSHIFT); 225 } 226 227 int rdopen(dev, flag, fmt, proc) 228 dev_t dev; 229 int flag, fmt; 230 struct proc *proc; 231 { 232 int md, unit; 233 struct rd_softc *sc; 234 235 md = minor(dev); 236 unit = RD_UNIT(md); 237 if (unit >= ramdisk_ndevs) 238 return ENXIO; 239 sc = ramdisk_devs[unit]; 240 if (sc == NULL) 241 return ENXIO; 242 243 /* 244 * The control device is not exclusive, and can 245 * open uninitialized units (so you can setconf). 246 */ 247 if (RD_IS_CTRL(md)) 248 return 0; 249 250 #ifdef RAMDISK_HOOKS 251 /* Call the open hook to allow loading the device. */ 252 rd_open_hook(unit, &sc->sc_rd); 253 #endif 254 255 /* 256 * This is a normal, "slave" device, so 257 * enforce initialized, exclusive open. 258 */ 259 if (sc->sc_type == RD_UNCONFIGURED) 260 return ENXIO; 261 if (sc->sc_flags & RD_ISOPEN) 262 return EBUSY; 263 264 return 0; 265 } 266 267 int rdclose(dev, flag, fmt, proc) 268 dev_t dev; 269 int flag, fmt; 270 struct proc *proc; 271 { 272 int md, unit; 273 struct rd_softc *sc; 274 275 md = minor(dev); 276 unit = RD_UNIT(md); 277 sc = ramdisk_devs[unit]; 278 279 if (RD_IS_CTRL(md)) 280 return 0; 281 282 /* Normal device. */ 283 sc->sc_flags = 0; 284 285 return 0; 286 } 287 288 int 289 rdread(dev, uio) 290 dev_t dev; 291 struct uio *uio; 292 { 293 return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); 294 } 295 296 int 297 rdwrite(dev, uio) 298 dev_t dev; 299 struct uio *uio; 300 { 301 return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio)); 302 } 303 304 /* 305 * Handle I/O requests, either directly, or 306 * by passing them to the server process. 307 */ 308 void 309 rdstrategy(bp) 310 struct buf *bp; 311 { 312 int md, unit; 313 struct rd_softc *sc; 314 caddr_t addr; 315 size_t off, xfer; 316 317 md = minor(bp->b_dev); 318 unit = RD_UNIT(md); 319 sc = ramdisk_devs[unit]; 320 321 switch (sc->sc_type) { 322 #if RAMDISK_SERVER 323 case RD_UMEM_SERVER: 324 /* Just add this job to the server's queue. */ 325 bp->b_actf = sc->sc_buflist; 326 sc->sc_buflist = bp; 327 if (bp->b_actf == NULL) { 328 /* server queue was empty. */ 329 wakeup((caddr_t)sc); 330 /* see rd_server_loop() */ 331 } 332 /* no biodone in this case */ 333 return; 334 #endif /* RAMDISK_SERVER */ 335 336 case RD_KMEM_FIXED: 337 case RD_KMEM_ALLOCATED: 338 /* These are in kernel space. Access directly. */ 339 bp->b_resid = bp->b_bcount; 340 off = (bp->b_blkno << DEV_BSHIFT); 341 if (off >= sc->sc_size) { 342 if (bp->b_flags & B_READ) 343 break; /* EOF */ 344 goto set_eio; 345 } 346 xfer = bp->b_resid; 347 if (xfer > (sc->sc_size - off)) 348 xfer = (sc->sc_size - off); 349 addr = sc->sc_addr + off; 350 if (bp->b_flags & B_READ) 351 bcopy(addr, bp->b_data, xfer); 352 else 353 bcopy(bp->b_data, addr, xfer); 354 bp->b_resid -= xfer; 355 break; 356 357 default: 358 bp->b_resid = bp->b_bcount; 359 set_eio: 360 bp->b_error = EIO; 361 bp->b_flags |= B_ERROR; 362 break; 363 } 364 biodone(bp); 365 } 366 367 int 368 rdioctl(dev, cmd, data, flag, proc) 369 dev_t dev; 370 u_long cmd; 371 int flag; 372 caddr_t data; 373 struct proc *proc; 374 { 375 int md, unit; 376 struct rd_softc *sc; 377 struct rd_conf *urd; 378 379 md = minor(dev); 380 unit = RD_UNIT(md); 381 sc = ramdisk_devs[unit]; 382 383 /* If this is not the control device, punt! */ 384 if (RD_IS_CTRL(md) == 0) 385 return ENOTTY; 386 387 urd = (struct rd_conf *)data; 388 switch (cmd) { 389 case RD_GETCONF: 390 *urd = sc->sc_rd; 391 return 0; 392 393 case RD_SETCONF: 394 /* Can only set it once. */ 395 if (sc->sc_type != RD_UNCONFIGURED) 396 break; 397 switch (urd->rd_type) { 398 case RD_KMEM_ALLOCATED: 399 return rd_ioctl_kalloc(sc, urd, proc); 400 #if RAMDISK_SERVER 401 case RD_UMEM_SERVER: 402 return rd_ioctl_server(sc, urd, proc); 403 #endif 404 default: 405 break; 406 } 407 break; 408 } 409 return EINVAL; 410 } 411 412 /* 413 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 414 * Just allocate some kernel memory and return. 415 */ 416 int 417 rd_ioctl_kalloc(sc, urd, proc) 418 struct rd_softc *sc; 419 struct rd_conf *urd; 420 struct proc *proc; 421 { 422 vm_offset_t addr; 423 vm_size_t size; 424 425 /* Sanity check the size. */ 426 size = urd->rd_size; 427 addr = kmem_alloc(kernel_map, size); 428 if (!addr) 429 return ENOMEM; 430 431 /* This unit is now configured. */ 432 sc->sc_addr = (caddr_t)addr; /* kernel space */ 433 sc->sc_size = (size_t)size; 434 sc->sc_type = RD_KMEM_ALLOCATED; 435 return 0; 436 } 437 438 #if RAMDISK_SERVER 439 440 /* 441 * Handle ioctl RD_SETCONF for (sc_type == RD_UMEM_SERVER) 442 * Set config, then become the I/O server for this unit. 443 */ 444 int 445 rd_ioctl_server(sc, urd, proc) 446 struct rd_softc *sc; 447 struct rd_conf *urd; 448 struct proc *proc; 449 { 450 vm_offset_t end; 451 int error; 452 453 /* Sanity check addr, size. */ 454 end = (vm_offset_t) (urd->rd_addr + urd->rd_size); 455 456 if ((end >= VM_MAXUSER_ADDRESS) || 457 (end < ((vm_offset_t) urd->rd_addr)) ) 458 return EINVAL; 459 460 /* This unit is now configured. */ 461 sc->sc_addr = urd->rd_addr; /* user space */ 462 sc->sc_size = urd->rd_size; 463 sc->sc_type = RD_UMEM_SERVER; 464 465 /* Become the server daemon */ 466 error = rd_server_loop(sc); 467 468 /* This server is now going away! */ 469 sc->sc_type = RD_UNCONFIGURED; 470 sc->sc_addr = 0; 471 sc->sc_size = 0; 472 473 return (error); 474 } 475 476 int rd_sleep_pri = PWAIT | PCATCH; 477 478 static int 479 rd_server_loop(sc) 480 struct rd_softc *sc; 481 { 482 struct buf *bp; 483 caddr_t addr; /* user space address */ 484 size_t off; /* offset into "device" */ 485 size_t xfer; /* amount to transfer */ 486 int error; 487 488 for (;;) { 489 /* Wait for some work to arrive. */ 490 while (sc->sc_buflist == NULL) { 491 error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0); 492 if (error) 493 return error; 494 } 495 496 /* Unlink buf from head of list. */ 497 bp = sc->sc_buflist; 498 sc->sc_buflist = bp->b_actf; 499 bp->b_actf = NULL; 500 501 /* Do the transfer to/from user space. */ 502 error = 0; 503 bp->b_resid = bp->b_bcount; 504 off = (bp->b_blkno << DEV_BSHIFT); 505 if (off >= sc->sc_size) { 506 if (bp->b_flags & B_READ) 507 goto done; /* EOF (not an error) */ 508 error = EIO; 509 goto done; 510 } 511 xfer = bp->b_resid; 512 if (xfer > (sc->sc_size - off)) 513 xfer = (sc->sc_size - off); 514 addr = sc->sc_addr + off; 515 if (bp->b_flags & B_READ) 516 error = copyin(addr, bp->b_data, xfer); 517 else 518 error = copyout(bp->b_data, addr, xfer); 519 if (!error) 520 bp->b_resid -= xfer; 521 522 done: 523 if (error) { 524 bp->b_error = error; 525 bp->b_flags |= B_ERROR; 526 } 527 biodone(bp); 528 } 529 } 530 531 #endif /* RAMDISK_SERVER */ 532
Indexes created Fri Sep 26 20:09:58 GMT 2025