md.c revision 1.4
1 /* $NetBSD: md.c,v 1.4 1996/01/07 22:03:31 thorpej 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/systm.h> 50 #include <sys/buf.h> 51 #include <sys/device.h> 52 #include <sys/disk.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_kern.h> 56 /* Don't want all those other VM headers... */ 57 extern vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t)); 58 59 #include <dev/ramdisk.h> 60 61 /* 62 * By default, include the user-space functionality. 63 * Use: option RAMDISK_SERVER=0 to turn it off. 64 */ 65 #ifndef RAMDISK_SERVER 66 #define RAMDISK_SERVER 1 67 #endif 68 69 /* 70 * XXX: the "control" unit is (base unit + 16). 71 * We should just use the cdev as the "control", but 72 * that interferes with the security stuff preventing 73 * simulatneous use of raw and block devices. 74 * 75 * XXX Assumption: 16 RAM-disks are enough! 76 */ 77 #define RD_IS_CTRL(unit) (unit & 0x10) 78 #define RD_UNIT(unit) (unit & 0xF) 79 80 /* 81 * XXX - This is just for a sanity check. Only 82 * applies to kernel-space RAM disk allocations. 83 */ 84 #define RD_KMEM_MAX_SIZE 0x100000 /* 1MB */ 85 86 /* autoconfig stuff... */ 87 88 struct rd_softc { 89 struct device sc_dev; /* REQUIRED first entry */ 90 struct disk sc_dkdev; /* hook for generic disk handling */ 91 struct rd_conf sc_rd; 92 struct buf *sc_buflist; 93 int sc_flags; 94 }; 95 /* shorthand for fields in sc_rd: */ 96 #define sc_addr sc_rd.rd_addr 97 #define sc_size sc_rd.rd_size 98 #define sc_type sc_rd.rd_type 99 /* flags */ 100 #define RD_ISOPEN 0x01 101 #define RD_SERVED 0x02 102 103 static int rd_match (struct device *, void *self, void *); 104 static void rd_attach(struct device *, struct device *self, void *); 105 106 struct cfdriver rdcd = { 107 NULL, "rd", rd_match, rd_attach, 108 DV_DULL, sizeof(struct rd_softc), NULL, 0 }; 109 110 void rdstrategy __P((struct buf *bp)); 111 112 struct dkdriver rddkdriver = { rdstrategy }; 113 114 static int 115 rd_match(parent, self, aux) 116 struct device *parent; 117 void *self; 118 void *aux; 119 { 120 return(1); 121 } 122 123 static void 124 rd_attach(parent, self, aux) 125 struct device *parent, *self; 126 void *aux; 127 { 128 struct rd_softc *sc = (struct rd_softc *)self; 129 130 /* XXX - Could accept aux info here to set the config. */ 131 #ifdef RAMDISK_HOOKS 132 /* 133 * This external function might setup a pre-loaded disk. 134 * All it would need to do is setup the rd_conf struct. 135 * See sys/arch/sun3/dev/rd_root.c for an example. 136 */ 137 rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd); 138 #endif 139 printf("\n"); 140 141 /* 142 * Initialize and attach the disk structure. 143 */ 144 bzero(&sc->sc_dkdev, sizeof(sc->sc_dkdev)); 145 sc->sc_dkdev.dk_driver = &rddkdriver; 146 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 147 disk_attach(&sc->sc_dkdev); 148 } 149 150 /* 151 * operational routines: 152 * open, close, read, write, strategy, 153 * ioctl, dump, size 154 */ 155 156 #if RAMDISK_SERVER 157 static int rd_server_loop __P((struct rd_softc *sc)); 158 static int rd_ioctl_server __P((struct rd_softc *sc, 159 struct rd_conf *urd, struct proc *proc)); 160 #endif 161 162 int rddump(dev, blkno, va, size) 163 dev_t dev; 164 daddr_t blkno; 165 caddr_t va; 166 size_t size; 167 { 168 return ENODEV; 169 } 170 171 int rdsize(dev_t dev) 172 { 173 int unit; 174 struct rd_softc *sc; 175 176 /* Disallow control units. */ 177 unit = minor(dev); 178 if (unit >= rdcd.cd_ndevs) 179 return 0; 180 sc = rdcd.cd_devs[unit]; 181 if (sc == NULL) 182 return 0; 183 184 if (sc->sc_type == RD_UNCONFIGURED) 185 return 0; 186 187 return (sc->sc_size >> DEV_BSHIFT); 188 } 189 190 int rdopen(dev, flag, fmt, proc) 191 dev_t dev; 192 int flag, fmt; 193 struct proc *proc; 194 { 195 int md, unit; 196 struct rd_softc *sc; 197 198 md = minor(dev); 199 unit = RD_UNIT(md); 200 if (unit >= rdcd.cd_ndevs) 201 return ENXIO; 202 sc = rdcd.cd_devs[unit]; 203 if (sc == NULL) 204 return ENXIO; 205 206 /* 207 * The control device is not exclusive, and can 208 * open uninitialized units (so you can setconf). 209 */ 210 if (RD_IS_CTRL(md)) 211 return 0; 212 213 #ifdef RAMDISK_HOOKS 214 /* Call the open hook to allow loading the device. */ 215 rd_open_hook(unit, &sc->sc_rd); 216 #endif 217 218 /* 219 * This is a normal, "slave" device, so 220 * enforce initialized, exclusive open. 221 */ 222 if (sc->sc_type == RD_UNCONFIGURED) 223 return ENXIO; 224 if (sc->sc_flags & RD_ISOPEN) 225 return EBUSY; 226 227 return 0; 228 } 229 230 int rdclose(dev, flag, fmt, proc) 231 dev_t dev; 232 int flag, fmt; 233 struct proc *proc; 234 { 235 int md, unit; 236 struct rd_softc *sc; 237 238 md = minor(dev); 239 unit = RD_UNIT(md); 240 sc = rdcd.cd_devs[unit]; 241 242 if (RD_IS_CTRL(md)) 243 return 0; 244 245 /* Normal device. */ 246 sc->sc_flags = 0; 247 248 return 0; 249 } 250 251 int 252 rdread(dev, uio) 253 dev_t dev; 254 struct uio *uio; 255 { 256 return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); 257 } 258 259 int 260 rdwrite(dev, uio) 261 dev_t dev; 262 struct uio *uio; 263 { 264 return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio)); 265 } 266 267 /* 268 * Handle I/O requests, either directly, or 269 * by passing them to the server process. 270 */ 271 void 272 rdstrategy(bp) 273 struct buf *bp; 274 { 275 int md, unit; 276 struct rd_softc *sc; 277 caddr_t addr; 278 size_t off, xfer; 279 280 md = minor(bp->b_dev); 281 unit = RD_UNIT(md); 282 sc = rdcd.cd_devs[unit]; 283 284 switch (sc->sc_type) { 285 #if RAMDISK_SERVER 286 case RD_UMEM_SERVER: 287 /* Just add this job to the server's queue. */ 288 bp->b_actf = sc->sc_buflist; 289 sc->sc_buflist = bp; 290 if (bp->b_actf == NULL) { 291 /* server queue was empty. */ 292 wakeup((caddr_t)sc); 293 /* see rd_server_loop() */ 294 } 295 /* no biodone in this case */ 296 return; 297 #endif /* RAMDISK_SERVER */ 298 299 case RD_KMEM_FIXED: 300 case RD_KMEM_ALLOCATED: 301 /* These are in kernel space. Access directly. */ 302 bp->b_resid = bp->b_bcount; 303 off = (bp->b_blkno << DEV_BSHIFT); 304 if (off >= sc->sc_size) { 305 if (bp->b_flags & B_READ) 306 break; /* EOF */ 307 goto set_eio; 308 } 309 xfer = bp->b_resid; 310 if (xfer > (sc->sc_size - off)) 311 xfer = (sc->sc_size - off); 312 addr = sc->sc_addr + off; 313 if (bp->b_flags & B_READ) 314 bcopy(addr, bp->b_data, xfer); 315 else 316 bcopy(bp->b_data, addr, xfer); 317 bp->b_resid -= xfer; 318 break; 319 320 default: 321 bp->b_resid = bp->b_bcount; 322 set_eio: 323 bp->b_error = EIO; 324 bp->b_flags |= B_ERROR; 325 break; 326 } 327 biodone(bp); 328 } 329 330 int 331 rdioctl(dev, cmd, data, flag, proc) 332 dev_t dev; 333 u_long cmd; 334 int flag; 335 caddr_t data; 336 struct proc *proc; 337 { 338 int md, unit; 339 struct rd_softc *sc; 340 struct rd_conf *urd; 341 342 md = minor(dev); 343 unit = RD_UNIT(md); 344 sc = rdcd.cd_devs[unit]; 345 346 /* If this is not the control device, punt! */ 347 if (RD_IS_CTRL(md) == 0) 348 return ENOTTY; 349 350 urd = (struct rd_conf *)data; 351 switch (cmd) { 352 case RD_GETCONF: 353 *urd = sc->sc_rd; 354 return 0; 355 356 case RD_SETCONF: 357 /* Can only set it once. */ 358 if (sc->sc_type != RD_UNCONFIGURED) 359 break; 360 switch (urd->rd_type) { 361 case RD_KMEM_ALLOCATED: 362 return rd_ioctl_kalloc(sc, urd, proc); 363 #if RAMDISK_SERVER 364 case RD_UMEM_SERVER: 365 return rd_ioctl_server(sc, urd, proc); 366 #endif 367 default: 368 break; 369 } 370 break; 371 } 372 return EINVAL; 373 } 374 375 /* 376 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 377 * Just allocate some kernel memory and return. 378 */ 379 int 380 rd_ioctl_kalloc(sc, urd, proc) 381 struct rd_softc *sc; 382 struct rd_conf *urd; 383 struct proc *proc; 384 { 385 vm_offset_t addr; 386 vm_size_t size; 387 388 /* Sanity check the size. */ 389 size = urd->rd_size; 390 if (size > RD_KMEM_MAX_SIZE) 391 return EINVAL; 392 addr = kmem_alloc(kernel_map, size); 393 if (!addr) 394 return ENOMEM; 395 396 /* This unit is now configured. */ 397 sc->sc_addr = (caddr_t)addr; /* kernel space */ 398 sc->sc_size = (size_t)size; 399 sc->sc_type = RD_KMEM_ALLOCATED; 400 return 0; 401 } 402 403 #if RAMDISK_SERVER 404 405 /* 406 * Handle ioctl RD_SETCONF for (sc_type == RD_UMEM_SERVER) 407 * Set config, then become the I/O server for this unit. 408 */ 409 int 410 rd_ioctl_server(sc, urd, proc) 411 struct rd_softc *sc; 412 struct rd_conf *urd; 413 struct proc *proc; 414 { 415 vm_offset_t end; 416 int error; 417 418 /* Sanity check addr, size. */ 419 end = (vm_offset_t) (urd->rd_addr + urd->rd_size); 420 421 if ((end >= VM_MAXUSER_ADDRESS) || 422 (end < ((vm_offset_t) urd->rd_addr)) ) 423 return EINVAL; 424 425 /* This unit is now configured. */ 426 sc->sc_addr = urd->rd_addr; /* user space */ 427 sc->sc_size = urd->rd_size; 428 sc->sc_type = RD_UMEM_SERVER; 429 430 /* Become the server daemon */ 431 error = rd_server_loop(sc); 432 433 /* This server is now going away! */ 434 sc->sc_type = RD_UNCONFIGURED; 435 sc->sc_addr = 0; 436 sc->sc_size = 0; 437 438 return (error); 439 } 440 441 int rd_sleep_pri = PWAIT | PCATCH; 442 443 static int 444 rd_server_loop(sc) 445 struct rd_softc *sc; 446 { 447 struct buf *bp; 448 caddr_t addr; /* user space address */ 449 size_t off; /* offset into "device" */ 450 size_t xfer; /* amount to transfer */ 451 int error; 452 453 for (;;) { 454 /* Wait for some work to arrive. */ 455 while (sc->sc_buflist == NULL) { 456 error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0); 457 if (error) 458 return error; 459 } 460 461 /* Unlink buf from head of list. */ 462 bp = sc->sc_buflist; 463 sc->sc_buflist = bp->b_actf; 464 bp->b_actf = NULL; 465 466 /* Do the transfer to/from user space. */ 467 error = 0; 468 bp->b_resid = bp->b_bcount; 469 off = (bp->b_blkno << DEV_BSHIFT); 470 if (off >= sc->sc_size) { 471 if (bp->b_flags & B_READ) 472 goto done; /* EOF (not an error) */ 473 error = EIO; 474 goto done; 475 } 476 xfer = bp->b_resid; 477 if (xfer > (sc->sc_size - off)) 478 xfer = (sc->sc_size - off); 479 addr = sc->sc_addr + off; 480 if (bp->b_flags & B_READ) 481 error = copyin(addr, bp->b_data, xfer); 482 else 483 error = copyout(bp->b_data, addr, xfer); 484 if (!error) 485 bp->b_resid -= xfer; 486 487 done: 488 if (error) { 489 bp->b_error = error; 490 bp->b_flags |= B_ERROR; 491 } 492 biodone(bp); 493 } 494 } 495 496 #endif /* RAMDISK_SERVER */ 497
Indexes created Thu Sep 25 16:09:42 GMT 2025