FreeBSD/Linux Kernel Cross Reference
sys/dev/md.c
1 /* $NetBSD: md.c,v 1.36 2003/06/29 22:30:00 fvdl 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-purpose memory-disk.
36 * See md.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 memory" code goes
45 * to the authors of the MFS implementation.
46 */
47
48 #include <sys/cdefs.h>
49 __KERNEL_RCSID(0, "$NetBSD: md.c,v 1.36 2003/06/29 22:30:00 fvdl Exp $");
50
51 #include "opt_md.h"
52
53 #include <sys/param.h>
54 #include <sys/kernel.h>
55 #include <sys/malloc.h>
56 #include <sys/systm.h>
57 #include <sys/buf.h>
58 #include <sys/device.h>
59 #include <sys/disk.h>
60 #include <sys/proc.h>
61 #include <sys/conf.h>
62 #include <sys/disklabel.h>
63
64 #include <uvm/uvm_extern.h>
65
66 #include <dev/md.h>
67
68 /*
69 * By default, include the user-space functionality.
70 * Use `options MEMORY_DISK_SERVER=0' to turn it off.
71 */
72 #ifndef MEMORY_DISK_SERVER
73 #define MEMORY_DISK_SERVER 1
74 #endif /* MEMORY_DISK_SERVER */
75
76 /*
77 * We should use the raw partition for ioctl.
78 */
79 #define MD_MAX_UNITS 0x10
80 #define MD_UNIT(unit) DISKUNIT(unit)
81
82 /* autoconfig stuff... */
83
84 struct md_softc {
85 struct device sc_dev; /* REQUIRED first entry */
86 struct disk sc_dkdev; /* hook for generic disk handling */
87 struct md_conf sc_md;
88 struct bufq_state sc_buflist;
89 };
90 /* shorthand for fields in sc_md: */
91 #define sc_addr sc_md.md_addr
92 #define sc_size sc_md.md_size
93 #define sc_type sc_md.md_type
94
95 void mdattach __P((int));
96 static void md_attach __P((struct device *, struct device *, void *));
97
98 dev_type_open(mdopen);
99 dev_type_close(mdclose);
100 dev_type_read(mdread);
101 dev_type_write(mdwrite);
102 dev_type_ioctl(mdioctl);
103 dev_type_strategy(mdstrategy);
104 dev_type_size(mdsize);
105
106 const struct bdevsw md_bdevsw = {
107 mdopen, mdclose, mdstrategy, mdioctl, nodump, mdsize, D_DISK
108 };
109
110 const struct cdevsw md_cdevsw = {
111 mdopen, mdclose, mdread, mdwrite, mdioctl,
112 nostop, notty, nopoll, nommap, nokqfilter, D_DISK
113 };
114
115 struct dkdriver mddkdriver = { mdstrategy };
116
117 static int ramdisk_ndevs;
118 static void *ramdisk_devs[MD_MAX_UNITS];
119
120 /*
121 * This is called if we are configured as a pseudo-device
122 */
123 void
124 mdattach(n)
125 int n;
126 {
127 struct md_softc *sc;
128 int i;
129
130 #ifdef DIAGNOSTIC
131 if (ramdisk_ndevs) {
132 aprint_error("ramdisk: multiple attach calls?\n");
133 return;
134 }
135 #endif
136
137 /* XXX: Are we supposed to provide a default? */
138 if (n <= 1)
139 n = 1;
140 if (n > MD_MAX_UNITS)
141 n = MD_MAX_UNITS;
142 ramdisk_ndevs = n;
143
144 /* Attach as if by autoconfig. */
145 for (i = 0; i < n; i++) {
146
147 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO);
148 if (!sc) {
149 aprint_error("ramdisk: malloc for attach failed!\n");
150 return;
151 }
152 ramdisk_devs[i] = sc;
153 sc->sc_dev.dv_unit = i;
154 sprintf(sc->sc_dev.dv_xname, "md%d", i);
155 md_attach(NULL, &sc->sc_dev, NULL);
156 }
157 }
158
159 static void
160 md_attach(parent, self, aux)
161 struct device *parent, *self;
162 void *aux;
163 {
164 struct md_softc *sc = (struct md_softc *)self;
165
166 bufq_alloc(&sc->sc_buflist, BUFQ_FCFS);
167
168 /* XXX - Could accept aux info here to set the config. */
169 #ifdef MEMORY_DISK_HOOKS
170 /*
171 * This external function might setup a pre-loaded disk.
172 * All it would need to do is setup the md_conf struct.
173 * See sys/dev/md_root.c for an example.
174 */
175 md_attach_hook(sc->sc_dev.dv_unit, &sc->sc_md);
176 #endif
177
178 /*
179 * Initialize and attach the disk structure.
180 */
181 sc->sc_dkdev.dk_driver = &mddkdriver;
182 sc->sc_dkdev.dk_name = sc->sc_dev.dv_xname;
183 disk_attach(&sc->sc_dkdev);
184 }
185
186 /*
187 * operational routines:
188 * open, close, read, write, strategy,
189 * ioctl, dump, size
190 */
191
192 #if MEMORY_DISK_SERVER
193 static int md_server_loop __P((struct md_softc *sc));
194 static int md_ioctl_server __P((struct md_softc *sc,
195 struct md_conf *umd, struct proc *proc));
196 #endif /* MEMORY_DISK_SERVER */
197 static int md_ioctl_kalloc __P((struct md_softc *sc,
198 struct md_conf *umd, struct proc *proc));
199
200 int
201 mdsize(dev_t dev)
202 {
203 int unit;
204 struct md_softc *sc;
205
206 unit = MD_UNIT(dev);
207 if (unit >= ramdisk_ndevs)
208 return 0;
209 sc = ramdisk_devs[unit];
210 if (sc == NULL)
211 return 0;
212
213 if (sc->sc_type == MD_UNCONFIGURED)
214 return 0;
215
216 return (sc->sc_size >> DEV_BSHIFT);
217 }
218
219 int
220 mdopen(dev, flag, fmt, proc)
221 dev_t dev;
222 int flag, fmt;
223 struct proc *proc;
224 {
225 int unit;
226 struct md_softc *sc;
227
228 unit = MD_UNIT(dev);
229 if (unit >= ramdisk_ndevs)
230 return ENXIO;
231 sc = ramdisk_devs[unit];
232 if (sc == NULL)
233 return ENXIO;
234
235 /*
236 * The raw partition is used for ioctl to configure.
237 */
238 if (DISKPART(dev) == RAW_PART)
239 return 0;
240
241 #ifdef MEMORY_DISK_HOOKS
242 /* Call the open hook to allow loading the device. */
243 md_open_hook(unit, &sc->sc_md);
244 #endif
245
246 /*
247 * This is a normal, "slave" device, so
248 * enforce initialized.
249 */
250 if (sc->sc_type == MD_UNCONFIGURED)
251 return ENXIO;
252
253 return 0;
254 }
255
256 int
257 mdclose(dev, flag, fmt, proc)
258 dev_t dev;
259 int flag, fmt;
260 struct proc *proc;
261 {
262 int unit;
263
264 unit = MD_UNIT(dev);
265
266 if (unit >= ramdisk_ndevs)
267 return ENXIO;
268
269 return 0;
270 }
271
272 int
273 mdread(dev, uio, flags)
274 dev_t dev;
275 struct uio *uio;
276 int flags;
277 {
278 int unit;
279 struct md_softc *sc;
280
281 unit = MD_UNIT(dev);
282
283 if (unit >= ramdisk_ndevs)
284 return ENXIO;
285
286 sc = ramdisk_devs[unit];
287
288 if (sc->sc_type == MD_UNCONFIGURED)
289 return ENXIO;
290
291 return (physio(mdstrategy, NULL, dev, B_READ, minphys, uio));
292 }
293
294 int
295 mdwrite(dev, uio, flags)
296 dev_t dev;
297 struct uio *uio;
298 int flags;
299 {
300 int unit;
301 struct md_softc *sc;
302
303 unit = MD_UNIT(dev);
304
305 if (unit >= ramdisk_ndevs)
306 return ENXIO;
307
308 sc = ramdisk_devs[unit];
309
310 if (sc->sc_type == MD_UNCONFIGURED)
311 return ENXIO;
312
313 return (physio(mdstrategy, NULL, dev, B_WRITE, minphys, uio));
314 }
315
316 /*
317 * Handle I/O requests, either directly, or
318 * by passing them to the server process.
319 */
320 void
321 mdstrategy(bp)
322 struct buf *bp;
323 {
324 int unit;
325 struct md_softc *sc;
326 caddr_t addr;
327 size_t off, xfer;
328
329 unit = MD_UNIT(bp->b_dev);
330 sc = ramdisk_devs[unit];
331
332 if (sc->sc_type == MD_UNCONFIGURED) {
333 bp->b_error = ENXIO;
334 bp->b_flags |= B_ERROR;
335 goto done;
336 }
337
338 switch (sc->sc_type) {
339 #if MEMORY_DISK_SERVER
340 case MD_UMEM_SERVER:
341 /* Just add this job to the server's queue. */
342 BUFQ_PUT(&sc->sc_buflist, bp);
343 wakeup((caddr_t)sc);
344 /* see md_server_loop() */
345 /* no biodone in this case */
346 return;
347 #endif /* MEMORY_DISK_SERVER */
348
349 case MD_KMEM_FIXED:
350 case MD_KMEM_ALLOCATED:
351 /* These are in kernel space. Access directly. */
352 bp->b_resid = bp->b_bcount;
353 off = (bp->b_blkno << DEV_BSHIFT);
354 if (off >= sc->sc_size) {
355 if (bp->b_flags & B_READ)
356 break; /* EOF */
357 goto set_eio;
358 }
359 xfer = bp->b_resid;
360 if (xfer > (sc->sc_size - off))
361 xfer = (sc->sc_size - off);
362 addr = sc->sc_addr + off;
363 if (bp->b_flags & B_READ)
364 memcpy(bp->b_data, addr, xfer);
365 else
366 memcpy(addr, bp->b_data, xfer);
367 bp->b_resid -= xfer;
368 break;
369
370 default:
371 bp->b_resid = bp->b_bcount;
372 set_eio:
373 bp->b_error = EIO;
374 bp->b_flags |= B_ERROR;
375 break;
376 }
377 done:
378 biodone(bp);
379 }
380
381 int
382 mdioctl(dev, cmd, data, flag, proc)
383 dev_t dev;
384 u_long cmd;
385 int flag;
386 caddr_t data;
387 struct proc *proc;
388 {
389 int unit;
390 struct md_softc *sc;
391 struct md_conf *umd;
392
393 unit = MD_UNIT(dev);
394 sc = ramdisk_devs[unit];
395
396 /* If this is not the raw partition, punt! */
397 if (DISKPART(dev) != RAW_PART)
398 return ENOTTY;
399
400 umd = (struct md_conf *)data;
401 switch (cmd) {
402 case MD_GETCONF:
403 *umd = sc->sc_md;
404 return 0;
405
406 case MD_SETCONF:
407 /* Can only set it once. */
408 if (sc->sc_type != MD_UNCONFIGURED)
409 break;
410 switch (umd->md_type) {
411 case MD_KMEM_ALLOCATED:
412 return md_ioctl_kalloc(sc, umd, proc);
413 #if MEMORY_DISK_SERVER
414 case MD_UMEM_SERVER:
415 return md_ioctl_server(sc, umd, proc);
416 #endif /* MEMORY_DISK_SERVER */
417 default:
418 break;
419 }
420 break;
421 }
422 return EINVAL;
423 }
424
425 /*
426 * Handle ioctl MD_SETCONF for (sc_type == MD_KMEM_ALLOCATED)
427 * Just allocate some kernel memory and return.
428 */
429 static int
430 md_ioctl_kalloc(sc, umd, proc)
431 struct md_softc *sc;
432 struct md_conf *umd;
433 struct proc *proc;
434 {
435 vaddr_t addr;
436 vsize_t size;
437
438 /* Sanity check the size. */
439 size = umd->md_size;
440 addr = uvm_km_zalloc(kernel_map, size);
441 if (!addr)
442 return ENOMEM;
443
444 /* This unit is now configured. */
445 sc->sc_addr = (caddr_t)addr; /* kernel space */
446 sc->sc_size = (size_t)size;
447 sc->sc_type = MD_KMEM_ALLOCATED;
448 return 0;
449 }
450
451 #if MEMORY_DISK_SERVER
452
453 /*
454 * Handle ioctl MD_SETCONF for (sc_type == MD_UMEM_SERVER)
455 * Set config, then become the I/O server for this unit.
456 */
457 static int
458 md_ioctl_server(sc, umd, proc)
459 struct md_softc *sc;
460 struct md_conf *umd;
461 struct proc *proc;
462 {
463 vaddr_t end;
464 int error;
465
466 /* Sanity check addr, size. */
467 end = (vaddr_t) (umd->md_addr + umd->md_size);
468
469 if ((end >= VM_MAXUSER_ADDRESS) ||
470 (end < ((vaddr_t) umd->md_addr)) )
471 return EINVAL;
472
473 /* This unit is now configured. */
474 sc->sc_addr = umd->md_addr; /* user space */
475 sc->sc_size = umd->md_size;
476 sc->sc_type = MD_UMEM_SERVER;
477
478 /* Become the server daemon */
479 error = md_server_loop(sc);
480
481 /* This server is now going away! */
482 sc->sc_type = MD_UNCONFIGURED;
483 sc->sc_addr = 0;
484 sc->sc_size = 0;
485
486 return (error);
487 }
488
489 int md_sleep_pri = PWAIT | PCATCH;
490
491 static int
492 md_server_loop(sc)
493 struct md_softc *sc;
494 {
495 struct buf *bp;
496 caddr_t addr; /* user space address */
497 size_t off; /* offset into "device" */
498 size_t xfer; /* amount to transfer */
499 int error;
500
501 for (;;) {
502 /* Wait for some work to arrive. */
503 while ((bp = BUFQ_GET(&sc->sc_buflist)) == NULL) {
504 error = tsleep((caddr_t)sc, md_sleep_pri, "md_idle", 0);
505 if (error)
506 return error;
507 }
508
509 /* Do the transfer to/from user space. */
510 error = 0;
511 bp->b_resid = bp->b_bcount;
512 off = (bp->b_blkno << DEV_BSHIFT);
513 if (off >= sc->sc_size) {
514 if (bp->b_flags & B_READ)
515 goto done; /* EOF (not an error) */
516 error = EIO;
517 goto done;
518 }
519 xfer = bp->b_resid;
520 if (xfer > (sc->sc_size - off))
521 xfer = (sc->sc_size - off);
522 addr = sc->sc_addr + off;
523 if (bp->b_flags & B_READ)
524 error = copyin(addr, bp->b_data, xfer);
525 else
526 error = copyout(bp->b_data, addr, xfer);
527 if (!error)
528 bp->b_resid -= xfer;
529
530 done:
531 if (error) {
532 bp->b_error = error;
533 bp->b_flags |= B_ERROR;
534 }
535 biodone(bp);
536 }
537 }
538 #endif /* MEMORY_DISK_SERVER */
Cache object: c2c09cfb82bd0737bfe1b1c399cba624
|