md.c revision 1.5
1 /* $NetBSD: md.c,v 1.5 1996/03/07 10:26:29 leo 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 #ifdef RAMDISK_HOOKS 121 /* 122 * This external function allows for a machine dependent 123 * match function. 124 */ 125 return (rd_match_hook(parent, self, aux)); 126 #else 127 return(1); 128 #endif 129 } 130 131 static void 132 rd_attach(parent, self, aux) 133 struct device *parent, *self; 134 void *aux; 135 { 136 struct rd_softc *sc = (struct rd_softc *)self; 137 138 /* XXX - Could accept aux info here to set the config. */ 139 #ifdef RAMDISK_HOOKS 140 /* 141 * This external function might setup a pre-loaded disk. 142 * All it would need to do is setup the rd_conf struct. 143 * See sys/arch/sun3/dev/rd_root.c for an example. 144 */ 145 rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd); 146 #endif 147 printf("\n"); 148 149 /* 150 * Initialize and attach the disk structure. 151 */ 152 bzero(&sc->sc_dkdev, sizeof(sc->sc_dkdev)); 153 sc->sc_dkdev.dk_driver = &rddkdriver; 154 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 155 disk_attach(&sc->sc_dkdev); 156 } 157 158 /* 159 * operational routines: 160 * open, close, read, write, strategy, 161 * ioctl, dump, size 162 */ 163 164 #if RAMDISK_SERVER 165 static int rd_server_loop __P((struct rd_softc *sc)); 166 static int rd_ioctl_server __P((struct rd_softc *sc, 167 struct rd_conf *urd, struct proc *proc)); 168 #endif 169 170 int rddump(dev, blkno, va, size) 171 dev_t dev; 172 daddr_t blkno; 173 caddr_t va; 174 size_t size; 175 { 176 return ENODEV; 177 } 178 179 int rdsize(dev_t dev) 180 { 181 int unit; 182 struct rd_softc *sc; 183 184 /* Disallow control units. */ 185 unit = minor(dev); 186 if (unit >= rdcd.cd_ndevs) 187 return 0; 188 sc = rdcd.cd_devs[unit]; 189 if (sc == NULL) 190 return 0; 191 192 if (sc->sc_type == RD_UNCONFIGURED) 193 return 0; 194 195 return (sc->sc_size >> DEV_BSHIFT); 196 } 197 198 int rdopen(dev, flag, fmt, proc) 199 dev_t dev; 200 int flag, fmt; 201 struct proc *proc; 202 { 203 int md, unit; 204 struct rd_softc *sc; 205 206 md = minor(dev); 207 unit = RD_UNIT(md); 208 if (unit >= rdcd.cd_ndevs) 209 return ENXIO; 210 sc = rdcd.cd_devs[unit]; 211 if (sc == NULL) 212 return ENXIO; 213 214 /* 215 * The control device is not exclusive, and can 216 * open uninitialized units (so you can setconf). 217 */ 218 if (RD_IS_CTRL(md)) 219 return 0; 220 221 #ifdef RAMDISK_HOOKS 222 /* Call the open hook to allow loading the device. */ 223 rd_open_hook(unit, &sc->sc_rd); 224 #endif 225 226 /* 227 * This is a normal, "slave" device, so 228 * enforce initialized, exclusive open. 229 */ 230 if (sc->sc_type == RD_UNCONFIGURED) 231 return ENXIO; 232 if (sc->sc_flags & RD_ISOPEN) 233 return EBUSY; 234 235 return 0; 236 } 237 238 int rdclose(dev, flag, fmt, proc) 239 dev_t dev; 240 int flag, fmt; 241 struct proc *proc; 242 { 243 int md, unit; 244 struct rd_softc *sc; 245 246 md = minor(dev); 247 unit = RD_UNIT(md); 248 sc = rdcd.cd_devs[unit]; 249 250 if (RD_IS_CTRL(md)) 251 return 0; 252 253 /* Normal device. */ 254 sc->sc_flags = 0; 255 256 return 0; 257 } 258 259 int 260 rdread(dev, uio) 261 dev_t dev; 262 struct uio *uio; 263 { 264 return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); 265 } 266 267 int 268 rdwrite(dev, uio) 269 dev_t dev; 270 struct uio *uio; 271 { 272 return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio)); 273 } 274 275 /* 276 * Handle I/O requests, either directly, or 277 * by passing them to the server process. 278 */ 279 void 280 rdstrategy(bp) 281 struct buf *bp; 282 { 283 int md, unit; 284 struct rd_softc *sc; 285 caddr_t addr; 286 size_t off, xfer; 287 288 md = minor(bp->b_dev); 289 unit = RD_UNIT(md); 290 sc = rdcd.cd_devs[unit]; 291 292 switch (sc->sc_type) { 293 #if RAMDISK_SERVER 294 case RD_UMEM_SERVER: 295 /* Just add this job to the server's queue. */ 296 bp->b_actf = sc->sc_buflist; 297 sc->sc_buflist = bp; 298 if (bp->b_actf == NULL) { 299 /* server queue was empty. */ 300 wakeup((caddr_t)sc); 301 /* see rd_server_loop() */ 302 } 303 /* no biodone in this case */ 304 return; 305 #endif /* RAMDISK_SERVER */ 306 307 case RD_KMEM_FIXED: 308 case RD_KMEM_ALLOCATED: 309 /* These are in kernel space. Access directly. */ 310 bp->b_resid = bp->b_bcount; 311 off = (bp->b_blkno << DEV_BSHIFT); 312 if (off >= sc->sc_size) { 313 if (bp->b_flags & B_READ) 314 break; /* EOF */ 315 goto set_eio; 316 } 317 xfer = bp->b_resid; 318 if (xfer > (sc->sc_size - off)) 319 xfer = (sc->sc_size - off); 320 addr = sc->sc_addr + off; 321 if (bp->b_flags & B_READ) 322 bcopy(addr, bp->b_data, xfer); 323 else 324 bcopy(bp->b_data, addr, xfer); 325 bp->b_resid -= xfer; 326 break; 327 328 default: 329 bp->b_resid = bp->b_bcount; 330 set_eio: 331 bp->b_error = EIO; 332 bp->b_flags |= B_ERROR; 333 break; 334 } 335 biodone(bp); 336 } 337 338 int 339 rdioctl(dev, cmd, data, flag, proc) 340 dev_t dev; 341 u_long cmd; 342 int flag; 343 caddr_t data; 344 struct proc *proc; 345 { 346 int md, unit; 347 struct rd_softc *sc; 348 struct rd_conf *urd; 349 350 md = minor(dev); 351 unit = RD_UNIT(md); 352 sc = rdcd.cd_devs[unit]; 353 354 /* If this is not the control device, punt! */ 355 if (RD_IS_CTRL(md) == 0) 356 return ENOTTY; 357 358 urd = (struct rd_conf *)data; 359 switch (cmd) { 360 case RD_GETCONF: 361 *urd = sc->sc_rd; 362 return 0; 363 364 case RD_SETCONF: 365 /* Can only set it once. */ 366 if (sc->sc_type != RD_UNCONFIGURED) 367 break; 368 switch (urd->rd_type) { 369 case RD_KMEM_ALLOCATED: 370 return rd_ioctl_kalloc(sc, urd, proc); 371 #if RAMDISK_SERVER 372 case RD_UMEM_SERVER: 373 return rd_ioctl_server(sc, urd, proc); 374 #endif 375 default: 376 break; 377 } 378 break; 379 } 380 return EINVAL; 381 } 382 383 /* 384 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 385 * Just allocate some kernel memory and return. 386 */ 387 int 388 rd_ioctl_kalloc(sc, urd, proc) 389 struct rd_softc *sc; 390 struct rd_conf *urd; 391 struct proc *proc; 392 { 393 vm_offset_t addr; 394 vm_size_t size; 395 396 /* Sanity check the size. */ 397 size = urd->rd_size; 398 if (size > RD_KMEM_MAX_SIZE) 399 return EINVAL; 400 addr = kmem_alloc(kernel_map, size); 401 if (!addr) 402 return ENOMEM; 403 404 /* This unit is now configured. */ 405 sc->sc_addr = (caddr_t)addr; /* kernel space */ 406 sc->sc_size = (size_t)size; 407 sc->sc_type = RD_KMEM_ALLOCATED; 408 return 0; 409 } 410 411 #if RAMDISK_SERVER 412 413 /* 414 * Handle ioctl RD_SETCONF for (sc_type == RD_UMEM_SERVER) 415 * Set config, then become the I/O server for this unit. 416 */ 417 int 418 rd_ioctl_server(sc, urd, proc) 419 struct rd_softc *sc; 420 struct rd_conf *urd; 421 struct proc *proc; 422 { 423 vm_offset_t end; 424 int error; 425 426 /* Sanity check addr, size. */ 427 end = (vm_offset_t) (urd->rd_addr + urd->rd_size); 428 429 if ((end >= VM_MAXUSER_ADDRESS) || 430 (end < ((vm_offset_t) urd->rd_addr)) ) 431 return EINVAL; 432 433 /* This unit is now configured. */ 434 sc->sc_addr = urd->rd_addr; /* user space */ 435 sc->sc_size = urd->rd_size; 436 sc->sc_type = RD_UMEM_SERVER; 437 438 /* Become the server daemon */ 439 error = rd_server_loop(sc); 440 441 /* This server is now going away! */ 442 sc->sc_type = RD_UNCONFIGURED; 443 sc->sc_addr = 0; 444 sc->sc_size = 0; 445 446 return (error); 447 } 448 449 int rd_sleep_pri = PWAIT | PCATCH; 450 451 static int 452 rd_server_loop(sc) 453 struct rd_softc *sc; 454 { 455 struct buf *bp; 456 caddr_t addr; /* user space address */ 457 size_t off; /* offset into "device" */ 458 size_t xfer; /* amount to transfer */ 459 int error; 460 461 for (;;) { 462 /* Wait for some work to arrive. */ 463 while (sc->sc_buflist == NULL) { 464 error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0); 465 if (error) 466 return error; 467 } 468 469 /* Unlink buf from head of list. */ 470 bp = sc->sc_buflist; 471 sc->sc_buflist = bp->b_actf; 472 bp->b_actf = NULL; 473 474 /* Do the transfer to/from user space. */ 475 error = 0; 476 bp->b_resid = bp->b_bcount; 477 off = (bp->b_blkno << DEV_BSHIFT); 478 if (off >= sc->sc_size) { 479 if (bp->b_flags & B_READ) 480 goto done; /* EOF (not an error) */ 481 error = EIO; 482 goto done; 483 } 484 xfer = bp->b_resid; 485 if (xfer > (sc->sc_size - off)) 486 xfer = (sc->sc_size - off); 487 addr = sc->sc_addr + off; 488 if (bp->b_flags & B_READ) 489 error = copyin(addr, bp->b_data, xfer); 490 else 491 error = copyout(bp->b_data, addr, xfer); 492 if (!error) 493 bp->b_resid -= xfer; 494 495 done: 496 if (error) { 497 bp->b_error = error; 498 bp->b_flags |= B_ERROR; 499 } 500 biodone(bp); 501 } 502 } 503 504 #endif /* RAMDISK_SERVER */ 505
Indexes created Thu Sep 25 16:09:42 GMT 2025