md.c revision 1.6
1 /* $NetBSD: md.c,v 1.6 1996/03/17 00:43:52 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 cfattach rd_ca = { 107 sizeof(struct rd_softc), rd_match, rd_attach 108 }; 109 110 struct cfdriver rd_cd = { 111 NULL, "rd", DV_DULL, NULL, 0 112 }; 113 114 void rdstrategy __P((struct buf *bp)); 115 116 struct dkdriver rddkdriver = { rdstrategy }; 117 118 static int 119 rd_match(parent, self, aux) 120 struct device *parent; 121 void *self; 122 void *aux; 123 { 124 #ifdef RAMDISK_HOOKS 125 /* 126 * This external function allows for a machine dependent 127 * match function. 128 */ 129 return (rd_match_hook(parent, self, aux)); 130 #else 131 return(1); 132 #endif 133 } 134 135 static void 136 rd_attach(parent, self, aux) 137 struct device *parent, *self; 138 void *aux; 139 { 140 struct rd_softc *sc = (struct rd_softc *)self; 141 142 /* XXX - Could accept aux info here to set the config. */ 143 #ifdef RAMDISK_HOOKS 144 /* 145 * This external function might setup a pre-loaded disk. 146 * All it would need to do is setup the rd_conf struct. 147 * See sys/arch/sun3/dev/rd_root.c for an example. 148 */ 149 rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd); 150 #endif 151 printf("\n"); 152 153 /* 154 * Initialize and attach the disk structure. 155 */ 156 bzero(&sc->sc_dkdev, sizeof(sc->sc_dkdev)); 157 sc->sc_dkdev.dk_driver = &rddkdriver; 158 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname; 159 disk_attach(&sc->sc_dkdev); 160 } 161 162 /* 163 * operational routines: 164 * open, close, read, write, strategy, 165 * ioctl, dump, size 166 */ 167 168 #if RAMDISK_SERVER 169 static int rd_server_loop __P((struct rd_softc *sc)); 170 static int rd_ioctl_server __P((struct rd_softc *sc, 171 struct rd_conf *urd, struct proc *proc)); 172 #endif 173 174 int rddump(dev, blkno, va, size) 175 dev_t dev; 176 daddr_t blkno; 177 caddr_t va; 178 size_t size; 179 { 180 return ENODEV; 181 } 182 183 int rdsize(dev_t dev) 184 { 185 int unit; 186 struct rd_softc *sc; 187 188 /* Disallow control units. */ 189 unit = minor(dev); 190 if (unit >= rd_cd.cd_ndevs) 191 return 0; 192 sc = rd_cd.cd_devs[unit]; 193 if (sc == NULL) 194 return 0; 195 196 if (sc->sc_type == RD_UNCONFIGURED) 197 return 0; 198 199 return (sc->sc_size >> DEV_BSHIFT); 200 } 201 202 int rdopen(dev, flag, fmt, proc) 203 dev_t dev; 204 int flag, fmt; 205 struct proc *proc; 206 { 207 int md, unit; 208 struct rd_softc *sc; 209 210 md = minor(dev); 211 unit = RD_UNIT(md); 212 if (unit >= rd_cd.cd_ndevs) 213 return ENXIO; 214 sc = rd_cd.cd_devs[unit]; 215 if (sc == NULL) 216 return ENXIO; 217 218 /* 219 * The control device is not exclusive, and can 220 * open uninitialized units (so you can setconf). 221 */ 222 if (RD_IS_CTRL(md)) 223 return 0; 224 225 #ifdef RAMDISK_HOOKS 226 /* Call the open hook to allow loading the device. */ 227 rd_open_hook(unit, &sc->sc_rd); 228 #endif 229 230 /* 231 * This is a normal, "slave" device, so 232 * enforce initialized, exclusive open. 233 */ 234 if (sc->sc_type == RD_UNCONFIGURED) 235 return ENXIO; 236 if (sc->sc_flags & RD_ISOPEN) 237 return EBUSY; 238 239 return 0; 240 } 241 242 int rdclose(dev, flag, fmt, proc) 243 dev_t dev; 244 int flag, fmt; 245 struct proc *proc; 246 { 247 int md, unit; 248 struct rd_softc *sc; 249 250 md = minor(dev); 251 unit = RD_UNIT(md); 252 sc = rd_cd.cd_devs[unit]; 253 254 if (RD_IS_CTRL(md)) 255 return 0; 256 257 /* Normal device. */ 258 sc->sc_flags = 0; 259 260 return 0; 261 } 262 263 int 264 rdread(dev, uio) 265 dev_t dev; 266 struct uio *uio; 267 { 268 return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); 269 } 270 271 int 272 rdwrite(dev, uio) 273 dev_t dev; 274 struct uio *uio; 275 { 276 return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio)); 277 } 278 279 /* 280 * Handle I/O requests, either directly, or 281 * by passing them to the server process. 282 */ 283 void 284 rdstrategy(bp) 285 struct buf *bp; 286 { 287 int md, unit; 288 struct rd_softc *sc; 289 caddr_t addr; 290 size_t off, xfer; 291 292 md = minor(bp->b_dev); 293 unit = RD_UNIT(md); 294 sc = rd_cd.cd_devs[unit]; 295 296 switch (sc->sc_type) { 297 #if RAMDISK_SERVER 298 case RD_UMEM_SERVER: 299 /* Just add this job to the server's queue. */ 300 bp->b_actf = sc->sc_buflist; 301 sc->sc_buflist = bp; 302 if (bp->b_actf == NULL) { 303 /* server queue was empty. */ 304 wakeup((caddr_t)sc); 305 /* see rd_server_loop() */ 306 } 307 /* no biodone in this case */ 308 return; 309 #endif /* RAMDISK_SERVER */ 310 311 case RD_KMEM_FIXED: 312 case RD_KMEM_ALLOCATED: 313 /* These are in kernel space. Access directly. */ 314 bp->b_resid = bp->b_bcount; 315 off = (bp->b_blkno << DEV_BSHIFT); 316 if (off >= sc->sc_size) { 317 if (bp->b_flags & B_READ) 318 break; /* EOF */ 319 goto set_eio; 320 } 321 xfer = bp->b_resid; 322 if (xfer > (sc->sc_size - off)) 323 xfer = (sc->sc_size - off); 324 addr = sc->sc_addr + off; 325 if (bp->b_flags & B_READ) 326 bcopy(addr, bp->b_data, xfer); 327 else 328 bcopy(bp->b_data, addr, xfer); 329 bp->b_resid -= xfer; 330 break; 331 332 default: 333 bp->b_resid = bp->b_bcount; 334 set_eio: 335 bp->b_error = EIO; 336 bp->b_flags |= B_ERROR; 337 break; 338 } 339 biodone(bp); 340 } 341 342 int 343 rdioctl(dev, cmd, data, flag, proc) 344 dev_t dev; 345 u_long cmd; 346 int flag; 347 caddr_t data; 348 struct proc *proc; 349 { 350 int md, unit; 351 struct rd_softc *sc; 352 struct rd_conf *urd; 353 354 md = minor(dev); 355 unit = RD_UNIT(md); 356 sc = rd_cd.cd_devs[unit]; 357 358 /* If this is not the control device, punt! */ 359 if (RD_IS_CTRL(md) == 0) 360 return ENOTTY; 361 362 urd = (struct rd_conf *)data; 363 switch (cmd) { 364 case RD_GETCONF: 365 *urd = sc->sc_rd; 366 return 0; 367 368 case RD_SETCONF: 369 /* Can only set it once. */ 370 if (sc->sc_type != RD_UNCONFIGURED) 371 break; 372 switch (urd->rd_type) { 373 case RD_KMEM_ALLOCATED: 374 return rd_ioctl_kalloc(sc, urd, proc); 375 #if RAMDISK_SERVER 376 case RD_UMEM_SERVER: 377 return rd_ioctl_server(sc, urd, proc); 378 #endif 379 default: 380 break; 381 } 382 break; 383 } 384 return EINVAL; 385 } 386 387 /* 388 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 389 * Just allocate some kernel memory and return. 390 */ 391 int 392 rd_ioctl_kalloc(sc, urd, proc) 393 struct rd_softc *sc; 394 struct rd_conf *urd; 395 struct proc *proc; 396 { 397 vm_offset_t addr; 398 vm_size_t size; 399 400 /* Sanity check the size. */ 401 size = urd->rd_size; 402 if (size > RD_KMEM_MAX_SIZE) 403 return EINVAL; 404 addr = kmem_alloc(kernel_map, size); 405 if (!addr) 406 return ENOMEM; 407 408 /* This unit is now configured. */ 409 sc->sc_addr = (caddr_t)addr; /* kernel space */ 410 sc->sc_size = (size_t)size; 411 sc->sc_type = RD_KMEM_ALLOCATED; 412 return 0; 413 } 414 415 #if RAMDISK_SERVER 416 417 /* 418 * Handle ioctl RD_SETCONF for (sc_type == RD_UMEM_SERVER) 419 * Set config, then become the I/O server for this unit. 420 */ 421 int 422 rd_ioctl_server(sc, urd, proc) 423 struct rd_softc *sc; 424 struct rd_conf *urd; 425 struct proc *proc; 426 { 427 vm_offset_t end; 428 int error; 429 430 /* Sanity check addr, size. */ 431 end = (vm_offset_t) (urd->rd_addr + urd->rd_size); 432 433 if ((end >= VM_MAXUSER_ADDRESS) || 434 (end < ((vm_offset_t) urd->rd_addr)) ) 435 return EINVAL; 436 437 /* This unit is now configured. */ 438 sc->sc_addr = urd->rd_addr; /* user space */ 439 sc->sc_size = urd->rd_size; 440 sc->sc_type = RD_UMEM_SERVER; 441 442 /* Become the server daemon */ 443 error = rd_server_loop(sc); 444 445 /* This server is now going away! */ 446 sc->sc_type = RD_UNCONFIGURED; 447 sc->sc_addr = 0; 448 sc->sc_size = 0; 449 450 return (error); 451 } 452 453 int rd_sleep_pri = PWAIT | PCATCH; 454 455 static int 456 rd_server_loop(sc) 457 struct rd_softc *sc; 458 { 459 struct buf *bp; 460 caddr_t addr; /* user space address */ 461 size_t off; /* offset into "device" */ 462 size_t xfer; /* amount to transfer */ 463 int error; 464 465 for (;;) { 466 /* Wait for some work to arrive. */ 467 while (sc->sc_buflist == NULL) { 468 error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0); 469 if (error) 470 return error; 471 } 472 473 /* Unlink buf from head of list. */ 474 bp = sc->sc_buflist; 475 sc->sc_buflist = bp->b_actf; 476 bp->b_actf = NULL; 477 478 /* Do the transfer to/from user space. */ 479 error = 0; 480 bp->b_resid = bp->b_bcount; 481 off = (bp->b_blkno << DEV_BSHIFT); 482 if (off >= sc->sc_size) { 483 if (bp->b_flags & B_READ) 484 goto done; /* EOF (not an error) */ 485 error = EIO; 486 goto done; 487 } 488 xfer = bp->b_resid; 489 if (xfer > (sc->sc_size - off)) 490 xfer = (sc->sc_size - off); 491 addr = sc->sc_addr + off; 492 if (bp->b_flags & B_READ) 493 error = copyin(addr, bp->b_data, xfer); 494 else 495 error = copyout(bp->b_data, addr, xfer); 496 if (!error) 497 bp->b_resid -= xfer; 498 499 done: 500 if (error) { 501 bp->b_error = error; 502 bp->b_flags |= B_ERROR; 503 } 504 biodone(bp); 505 } 506 } 507 508 #endif /* RAMDISK_SERVER */ 509
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