md.c revision 1.1
1 /* $NetBSD: md.c,v 1.1 1995/10/08 23:30:57 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/systm.h> 50 #include <sys/buf.h> 51 #include <sys/device.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_kern.h> 55 /* Don't want all those other VM headers... */ 56 extern vm_offset_t kmem_alloc __P((vm_map_t, vm_size_t)); 57 58 #include <dev/ramdisk.h> 59 60 /* 61 * By default, include the user-space functionality. 62 * Use: option RAMDISK_SERVER=0 to turn it off. 63 */ 64 #ifndef RAMDISK_SERVER 65 #define RAMDISK_SERVER 1 66 #endif 67 68 /* 69 * XXX: the "control" unit is (base unit + 16). 70 * We should just use the cdev as the "control", but 71 * that interferes with the security stuff preventing 72 * simulatneous use of raw and block devices. 73 * 74 * XXX Assumption: 16 RAM-disks are enough! 75 */ 76 #define RD_IS_CTRL(unit) (unit & 0x10) 77 #define RD_UNIT(unit) (unit & 0xF) 78 79 /* 80 * XXX - This is just for a sanity check. Only 81 * applies to kernel-space RAM disk allocations. 82 */ 83 #define RD_KMEM_MAX_SIZE 0x100000 /* 1MB */ 84 85 /* autoconfig stuff... */ 86 87 struct rd_softc { 88 struct device sc_dev; /* REQUIRED first entry */ 89 struct rd_conf sc_rd; 90 struct buf *sc_buflist; 91 int sc_flags; 92 }; 93 /* shorthand for fields in sc_rd: */ 94 #define sc_addr sc_rd.rd_addr 95 #define sc_size sc_rd.rd_size 96 #define sc_type sc_rd.rd_type 97 /* flags */ 98 #define RD_ISOPEN 0x01 99 #define RD_SERVED 0x02 100 101 static int rd_match (struct device *, void *self, void *); 102 static void rd_attach(struct device *, struct device *self, void *); 103 104 struct cfdriver rdcd = { 105 NULL, "rd", rd_match, rd_attach, 106 DV_DISK, sizeof(struct device), NULL, 0 }; 107 108 static int 109 rd_match(parent, self, aux) 110 struct device *parent; 111 void *self; 112 void *aux; 113 { 114 return(1); 115 } 116 117 static void 118 rd_attach(parent, self, aux) 119 struct device *parent, *self; 120 void *aux; 121 { 122 struct rd_softc *sc = (struct rd_softc *)self; 123 124 /* XXX - Could accept aux info here to set the config. */ 125 #ifdef RAMDISK_HOOKS 126 /* 127 * This external function might setup a pre-loaded disk. 128 * All it would need to do is setup the rd_conf struct. 129 * See sys/arch/sun3/dev/rd_root.c for an example. 130 */ 131 rd_attach_hook(sc->sc_dev.dv_unit, &sc->sc_rd); 132 #endif 133 printf("\n"); 134 } 135 136 /* 137 * operational routines: 138 * open, close, read, write, strategy, 139 * ioctl, dump, size 140 */ 141 142 void rdstrategy __P((struct buf *bp)); 143 144 #if RAMDISK_SERVER 145 static int rd_server_loop __P((struct rd_softc *sc)); 146 static int rd_ioctl_server __P((struct rd_softc *sc, 147 struct rd_conf *urd, struct proc *proc)); 148 #endif 149 150 int rddump(dev, blkno, va, size) 151 dev_t dev; 152 daddr_t blkno; 153 caddr_t va; 154 size_t size; 155 { 156 return ENODEV; 157 } 158 159 int rdsize(dev_t dev) 160 { 161 int unit; 162 struct rd_softc *sc; 163 164 /* Disallow control units. */ 165 unit = minor(dev); 166 if (unit >= rdcd.cd_ndevs) 167 return 0; 168 sc = rdcd.cd_devs[unit]; 169 if (sc == NULL) 170 return 0; 171 172 if (sc->sc_type == RD_UNCONFIGURED) 173 return 0; 174 175 return (sc->sc_size >> DEV_BSHIFT); 176 } 177 178 int rdopen(dev, flag, fmt, proc) 179 dev_t dev; 180 int flag, fmt; 181 struct proc *proc; 182 { 183 int md, unit; 184 struct rd_softc *sc; 185 186 md = minor(dev); 187 unit = RD_UNIT(md); 188 if (unit >= rdcd.cd_ndevs) 189 return ENXIO; 190 sc = rdcd.cd_devs[unit]; 191 if (sc == NULL) 192 return ENXIO; 193 194 /* 195 * The control device is not exclusive, and can 196 * open uninitialized units (so you can setconf). 197 */ 198 if (RD_IS_CTRL(md)) 199 return 0; 200 201 #ifdef RAMDISK_HOOKS 202 /* Call the open hook to allow loading the device. */ 203 rd_open_hook(unit, &sc->sc_rd); 204 #endif 205 206 /* 207 * This is a normal, "slave" device, so 208 * enforce initialized, exclusive open. 209 */ 210 if (sc->sc_type == RD_UNCONFIGURED) 211 return ENXIO; 212 if (sc->sc_flags & RD_ISOPEN) 213 return EBUSY; 214 215 return 0; 216 } 217 218 int rdclose(dev, flag, fmt, proc) 219 dev_t dev; 220 int flag, fmt; 221 struct proc *proc; 222 { 223 int md, unit; 224 struct rd_softc *sc; 225 226 md = minor(dev); 227 unit = RD_UNIT(md); 228 sc = rdcd.cd_devs[unit]; 229 230 if (RD_IS_CTRL(md)) 231 return 0; 232 233 /* Normal device. */ 234 sc->sc_flags = 0; 235 236 return 0; 237 } 238 239 int 240 rdread(dev, uio) 241 dev_t dev; 242 struct uio *uio; 243 { 244 return (physio(rdstrategy, NULL, dev, B_READ, minphys, uio)); 245 } 246 247 int 248 rdwrite(dev, uio) 249 dev_t dev; 250 struct uio *uio; 251 { 252 return (physio(rdstrategy, NULL, dev, B_WRITE, minphys, uio)); 253 } 254 255 /* 256 * Handle I/O requests, either directly, or 257 * by passing them to the server process. 258 */ 259 void 260 rdstrategy(bp) 261 struct buf *bp; 262 { 263 int md, unit; 264 struct rd_softc *sc; 265 caddr_t addr; 266 size_t off, xfer; 267 268 md = minor(bp->b_dev); 269 unit = RD_UNIT(md); 270 sc = rdcd.cd_devs[unit]; 271 272 switch (sc->sc_type) { 273 #if RAMDISK_SERVER 274 case RD_UMEM_SERVER: 275 /* Just add this job to the server's queue. */ 276 bp->b_actf = sc->sc_buflist; 277 sc->sc_buflist = bp; 278 if (bp->b_actf == NULL) { 279 /* server queue was empty. */ 280 wakeup((caddr_t)sc); 281 /* see rd_server_loop() */ 282 } 283 /* no biodone in this case */ 284 return; 285 #endif /* RAMDISK_SERVER */ 286 287 case RD_KMEM_FIXED: 288 case RD_KMEM_ALLOCATED: 289 /* These are in kernel space. Access directly. */ 290 bp->b_resid = bp->b_bcount; 291 off = (bp->b_blkno << DEV_BSHIFT); 292 if (off >= sc->sc_size) { 293 if (bp->b_flags & B_READ) 294 break; /* EOF */ 295 goto set_eio; 296 } 297 xfer = bp->b_resid; 298 if (xfer > (sc->sc_size - off)) 299 xfer = (sc->sc_size - off); 300 addr = sc->sc_addr + off; 301 if (bp->b_flags & B_READ) 302 bcopy(addr, bp->b_data, xfer); 303 else 304 bcopy(bp->b_data, addr, xfer); 305 bp->b_resid -= xfer; 306 break; 307 308 default: 309 bp->b_resid = bp->b_bcount; 310 set_eio: 311 bp->b_error = EIO; 312 bp->b_flags |= B_ERROR; 313 break; 314 } 315 biodone(bp); 316 } 317 318 int 319 rdioctl(dev, cmd, data, flag, proc) 320 dev_t dev; 321 u_long cmd; 322 int flag; 323 caddr_t data; 324 struct proc *proc; 325 { 326 int md, unit; 327 struct rd_softc *sc; 328 struct rd_conf *urd; 329 330 md = minor(dev); 331 unit = RD_UNIT(md); 332 sc = rdcd.cd_devs[unit]; 333 334 /* If this is not the control device, punt! */ 335 if (RD_IS_CTRL(md) == 0) 336 return ENOTTY; 337 338 urd = (struct rd_conf *)data; 339 switch (cmd) { 340 case RD_GETCONF: 341 *urd = sc->sc_rd; 342 return 0; 343 344 case RD_SETCONF: 345 /* Can only set it once. */ 346 if (sc->sc_type != RD_UNCONFIGURED) 347 break; 348 switch (urd->rd_type) { 349 case RD_KMEM_ALLOCATED: 350 return rd_ioctl_kalloc(sc, urd, proc); 351 #if RAMDISK_SERVER 352 case RD_UMEM_SERVER: 353 return rd_ioctl_server(sc, urd, proc); 354 #endif 355 default: 356 break; 357 } 358 break; 359 } 360 return EINVAL; 361 } 362 363 /* 364 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 365 * Just allocate some kernel memory and return. 366 */ 367 int 368 rd_ioctl_kalloc(sc, urd, proc) 369 struct rd_softc *sc; 370 struct rd_conf *urd; 371 struct proc *proc; 372 { 373 vm_offset_t addr; 374 vm_size_t size; 375 376 /* Sanity check the size. */ 377 size = urd->rd_size; 378 if (size > RD_KMEM_MAX_SIZE) 379 return EINVAL; 380 addr = kmem_alloc(kernel_map, size); 381 if (!addr) 382 return ENOMEM; 383 384 /* This unit is now configured. */ 385 sc->sc_addr = (caddr_t)addr; /* kernel space */ 386 sc->sc_size = (size_t)size; 387 sc->sc_type = RD_KMEM_ALLOCATED; 388 return 0; 389 } 390 391 #if RAMDISK_SERVER 392 393 /* 394 * Handle ioctl RD_SETCONF for (sc_type == RD_KMEM_ALLOCATED) 395 * Set config, then become the I/O server for this unit. 396 */ 397 int 398 rd_ioctl_server(sc, urd, proc) 399 struct rd_softc *sc; 400 struct rd_conf *urd; 401 struct proc *proc; 402 { 403 vm_offset_t end; 404 int error; 405 406 /* Sanity check addr, size. */ 407 end = (vm_offset_t) (urd->rd_addr + urd->rd_size); 408 409 if ((end >= VM_MAXUSER_ADDRESS) || 410 (end < ((vm_offset_t) urd->rd_addr)) ) 411 return EINVAL; 412 413 /* This unit is now configured. */ 414 sc->sc_addr = urd->rd_addr; /* user space */ 415 sc->sc_size = urd->rd_size; 416 sc->sc_type = RD_UMEM_SERVER; 417 418 /* Become the server daemon */ 419 error = rd_server_loop(sc); 420 421 /* This server is now going away! */ 422 sc->sc_type = RD_UNCONFIGURED; 423 sc->sc_addr = 0; 424 sc->sc_size = 0; 425 426 return (error); 427 } 428 429 int rd_sleep_pri = PWAIT | PCATCH; 430 431 static int 432 rd_server_loop(sc) 433 struct rd_softc *sc; 434 { 435 struct buf *bp; 436 caddr_t addr; /* user space address */ 437 size_t off; /* offset into "device" */ 438 size_t xfer; /* amount to transfer */ 439 int error; 440 441 for (;;) { 442 /* Wait for some work to arrive. */ 443 while (sc->sc_buflist == NULL) { 444 error = tsleep((caddr_t)sc, rd_sleep_pri, "rd_idle", 0); 445 if (error) 446 return error; 447 } 448 449 /* Unlink buf from head of list. */ 450 bp = sc->sc_buflist; 451 sc->sc_buflist = bp->b_actf; 452 bp->b_actf = NULL; 453 454 /* Do the transfer to/from user space. */ 455 error = 0; 456 bp->b_resid = bp->b_bcount; 457 off = (bp->b_blkno << DEV_BSHIFT); 458 if (off >= sc->sc_size) { 459 if (bp->b_flags & B_READ) 460 goto done; /* EOF (not an error) */ 461 error = EIO; 462 goto done; 463 } 464 xfer = bp->b_resid; 465 if (xfer > (sc->sc_size - off)) 466 xfer = (sc->sc_size - off); 467 addr = sc->sc_addr + off; 468 if (bp->b_flags & B_READ) 469 error = copyin(addr, bp->b_data, xfer); 470 else 471 error = copyout(bp->b_data, addr, xfer); 472 if (!error) 473 bp->b_resid -= xfer; 474 475 done: 476 if (error) { 477 bp->b_error = error; 478 bp->b_flags |= B_ERROR; 479 } 480 biodone(bp); 481 } 482 } 483 484 #endif /* RAMDISK_SERVER */ 485
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