83f50d5a34126ef470c7f6ab65f92b258135dad8
[dragonfly.git] / sys / dev / disk / md / md.c
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD: src/sys/dev/md/md.c,v 1.8.2.2 2002/08/19 17:43:34 jdp Exp $
10  *
11  */
12
13 #include "opt_md.h"             /* We have adopted some tasks from MFS */
14
15 #include <sys/param.h>
16 #include <sys/systm.h>
17 #include <sys/buf.h>
18 #include <sys/conf.h>
19 #include <sys/devicestat.h>
20 #include <sys/disk.h>
21 #include <sys/kernel.h>
22 #include <sys/malloc.h>
23 #include <sys/sysctl.h>
24 #include <sys/linker.h>
25 #include <sys/proc.h>
26 #include <sys/buf2.h>
27 #include <sys/thread2.h>
28 #include <sys/queue.h>
29 #include <sys/udev.h>
30
31 #ifndef MD_NSECT
32 #define MD_NSECT (10000 * 2)
33 #endif
34
35 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk");
36 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors");
37
38 static int md_debug;
39 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0,
40     "Enable debug output for memory disk devices");
41
42 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE)
43 /* Image gets put here: */
44 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here";
45 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here";
46 #endif
47
48 static int mdrootready;
49
50 static d_strategy_t mdstrategy;
51 static d_strategy_t mdstrategy_preload;
52 static d_strategy_t mdstrategy_malloc;
53 static d_open_t mdopen;
54 static d_close_t mdclose;
55 static d_ioctl_t mdioctl;
56
57 static struct dev_ops md_ops = {
58         { "md", 0, D_DISK | D_CANFREE | D_MEMDISK | D_TRACKCLOSE},
59         .d_open =       mdopen,
60         .d_close =      mdclose,
61         .d_read =       physread,
62         .d_write =      physwrite,
63         .d_ioctl =      mdioctl,
64         .d_strategy =   mdstrategy,
65 };
66
67 struct md_s {
68         int unit;
69         struct devstat stats;
70         struct bio_queue_head bio_queue;
71         struct disk disk;
72         cdev_t dev;
73         int busy;
74         enum {                  /* Memory disk type */
75                 MD_MALLOC,
76                 MD_PRELOAD
77         } type;
78         unsigned nsect;
79
80         /* MD_MALLOC related fields */
81         unsigned nsecp;
82         u_char **secp;
83
84         /* MD_PRELOAD related fields */
85         u_char *pl_ptr;
86         unsigned pl_len;
87         TAILQ_ENTRY(md_s) link;
88 };
89 TAILQ_HEAD(mdshead, md_s) mdlist = TAILQ_HEAD_INITIALIZER(mdlist);
90
91 static int mdunits;
92 static int refcnt;
93
94 static struct md_s *mdcreate(unsigned);
95 static void mdcreate_malloc(void);
96 static int mdinit(module_t, int, void *);
97 static void md_drvinit(void *);
98 static int md_drvcleanup(void);
99
100 static int
101 mdinit(module_t mod, int cmd, void *arg)
102 {
103     int ret = 0;
104
105     switch(cmd) {
106         case MOD_LOAD:
107                 TAILQ_INIT(&mdlist);
108                 md_drvinit(NULL);
109                 break;
110         case MOD_UNLOAD:
111                 ret = md_drvcleanup();
112                 break;
113         default:
114                 ret = EINVAL;
115                 break;
116     }
117
118     return (ret);
119 }
120
121 static int
122 mdopen(struct dev_open_args *ap)
123 {
124         cdev_t dev = ap->a_head.a_dev;
125         struct md_s *sc;
126
127         if (md_debug)
128                 kprintf("mdopen(%s %x %x)\n",
129                         devtoname(dev), ap->a_oflags, ap->a_devtype);
130
131         sc = dev->si_drv1;
132         if (sc->unit + 1 == mdunits)
133                 mdcreate_malloc();
134
135         atomic_add_int(&refcnt, 1);
136         return (0);
137 }
138
139 static int
140 mdclose(struct dev_close_args *ap)
141 {
142         cdev_t dev = ap->a_head.a_dev;
143         struct md_s *sc;
144
145         if (md_debug)
146                 kprintf("mdclose(%s %x %x)\n",
147                         devtoname(dev), ap->a_fflag, ap->a_devtype);
148         sc = dev->si_drv1;
149         atomic_add_int(&refcnt, -1);
150
151         return (0);
152 }
153
154 static int
155 mdioctl(struct dev_ioctl_args *ap)
156 {
157         cdev_t dev = ap->a_head.a_dev;
158
159         if (md_debug)
160                 kprintf("mdioctl(%s %lx %p %x)\n",
161                         devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag);
162
163         return (ENOIOCTL);
164 }
165
166 static int
167 mdstrategy(struct dev_strategy_args *ap)
168 {
169         cdev_t dev = ap->a_head.a_dev;
170         struct bio *bio = ap->a_bio;
171         struct buf *bp = bio->bio_buf;
172         struct md_s *sc;
173
174         if (md_debug > 1) {
175                 kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n",
176                     bp, devtoname(dev), bp->b_flags,
177                     (long long)bio->bio_offset,
178                     bp->b_bcount, bp->b_data);
179         }
180         bio->bio_driver_info = dev;
181         sc = dev->si_drv1;
182         if (sc->type == MD_MALLOC) {
183                 mdstrategy_malloc(ap);
184         } else {
185                 mdstrategy_preload(ap);
186         }
187         return(0);
188 }
189
190
191 static int
192 mdstrategy_malloc(struct dev_strategy_args *ap)
193 {
194         cdev_t dev = ap->a_head.a_dev;
195         struct bio *bio = ap->a_bio;
196         struct buf *bp = bio->bio_buf;
197         unsigned secno, nsec, secval, uc;
198         u_char *secp, **secpp, *dst;
199         struct md_s *sc;
200         int i;
201
202         if (md_debug > 1)
203                 kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n",
204                     bp, devtoname(dev), bp->b_flags,
205                     (long long)bio->bio_offset,
206                     bp->b_bcount, bp->b_data);
207
208         sc = dev->si_drv1;
209
210         crit_enter();
211
212         bioqdisksort(&sc->bio_queue, bio);
213
214         if (sc->busy) {
215                 crit_exit();
216                 return(0);
217         }
218
219         sc->busy++;
220         
221         while (1) {
222                 bio = bioq_first(&sc->bio_queue);
223                 if (bio == NULL) {
224                         crit_exit();
225                         break;
226                 }
227                 crit_exit();
228                 bioq_remove(&sc->bio_queue, bio);
229                 bp = bio->bio_buf;
230
231                 devstat_start_transaction(&sc->stats);
232
233                 switch (bp->b_cmd) {
234                 case BUF_CMD_FREEBLKS:
235                 case BUF_CMD_READ:
236                 case BUF_CMD_WRITE:
237                         break;
238                 default:
239                         panic("md: bad b_cmd %d", bp->b_cmd);
240                 }
241
242                 nsec = bp->b_bcount >> DEV_BSHIFT;
243                 secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT);
244                 dst = bp->b_data;
245                 while (nsec--) {
246                         if (secno < sc->nsecp) {
247                                 secpp = &sc->secp[secno];
248                                 if ((u_int)(uintptr_t)*secpp > 255) {
249                                         secp = *secpp;
250                                         secval = 0;
251                                 } else {
252                                         secp = NULL;
253                                         secval = (u_int)(uintptr_t)*secpp;
254                                 }
255                         } else {
256                                 secpp = NULL;
257                                 secp = NULL;
258                                 secval = 0;
259                         }
260                         if (md_debug > 2)
261                                 kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval);
262
263                         switch (bp->b_cmd) {
264                         case BUF_CMD_FREEBLKS:
265                                 if (secpp) {
266                                         if (secp)
267                                                 kfree(secp, M_MDSECT);
268                                         *secpp = NULL;
269                                 }
270                                 break;
271                         case BUF_CMD_READ:
272                                 if (secp) {
273                                         bcopy(secp, dst, DEV_BSIZE);
274                                 } else if (secval) {
275                                         for (i = 0; i < DEV_BSIZE; i++)
276                                                 dst[i] = secval;
277                                 } else {
278                                         bzero(dst, DEV_BSIZE);
279                                 }
280                                 break;
281                         case BUF_CMD_WRITE:
282                                 uc = dst[0];
283                                 for (i = 1; i < DEV_BSIZE; i++) 
284                                         if (dst[i] != uc)
285                                                 break;
286                                 if (i == DEV_BSIZE && !uc) {
287                                         if (secp)
288                                                 kfree(secp, M_MDSECT);
289                                         if (secpp)
290                                                 *secpp = (u_char *)(uintptr_t)uc;
291                                 } else {
292                                         if (!secpp) {
293                                                 secpp = kmalloc((secno + nsec + 1) * sizeof(u_char *),
294                                                                 M_MD,
295                                                                 M_WAITOK | M_ZERO);
296                                                 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
297                                                 kfree(sc->secp, M_MD);
298                                                 sc->secp = secpp;
299                                                 sc->nsecp = secno + nsec + 1;
300                                                 secpp = &sc->secp[secno];
301                                         }
302                                         if (i == DEV_BSIZE) {
303                                                 if (secp)
304                                                         kfree(secp, M_MDSECT);
305                                                 *secpp = (u_char *)(uintptr_t)uc;
306                                         } else {
307                                                 if (!secp) 
308                                                         secp = kmalloc(DEV_BSIZE,
309                                                                        M_MDSECT,
310                                                                        M_WAITOK);
311                                                 bcopy(dst, secp, DEV_BSIZE);
312
313                                                 *secpp = secp;
314                                         }
315                                 }
316                                 break;
317                         default:
318                                 panic("md: bad b_cmd %d", bp->b_cmd);
319
320                         }
321                         secno++;
322                         dst += DEV_BSIZE;
323                 }
324                 bp->b_resid = 0;
325                 devstat_end_transaction_buf(&sc->stats, bp);
326                 biodone(bio);
327                 crit_enter();
328         }
329         sc->busy = 0;
330         return(0);
331 }
332
333
334 static int
335 mdstrategy_preload(struct dev_strategy_args *ap)
336 {
337         cdev_t dev = ap->a_head.a_dev;
338         struct bio *bio = ap->a_bio;
339         struct buf *bp = bio->bio_buf;
340         struct md_s *sc;
341
342         if (md_debug > 1)
343                 kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n",
344                     bp, devtoname(dev), bp->b_flags,
345                     (long long)bio->bio_offset,
346                     bp->b_bcount, bp->b_data);
347
348         sc = dev->si_drv1;
349
350         crit_enter();
351
352         bioqdisksort(&sc->bio_queue, bio);
353
354         if (sc->busy) {
355                 crit_exit();
356                 return(0);
357         }
358
359         sc->busy++;
360         
361         while (1) {
362                 bio = bioq_takefirst(&sc->bio_queue);
363                 crit_exit();
364                 if (bio == NULL)
365                         break;
366
367                 devstat_start_transaction(&sc->stats);
368
369                 switch (bp->b_cmd) {
370                 case BUF_CMD_FREEBLKS:
371                         break;
372                 case BUF_CMD_READ:
373                         bcopy(sc->pl_ptr + bio->bio_offset, 
374                                bp->b_data, bp->b_bcount);
375                         break;
376                 case BUF_CMD_WRITE:
377                         bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset,
378                               bp->b_bcount);
379                         break;
380                 default:
381                         panic("md: bad cmd %d", bp->b_cmd);
382                 }
383                 bp->b_resid = 0;
384                 devstat_end_transaction_buf(&sc->stats, bp);
385                 biodone(bio);
386                 crit_enter();
387         }
388         sc->busy = 0;
389         return(0);
390 }
391
392 static struct md_s *
393 mdcreate(unsigned length)
394 {
395         struct md_s *sc;
396         struct disk_info info;
397
398         sc = kmalloc(sizeof(*sc), M_MD, M_WAITOK | M_ZERO);
399         sc->unit = mdunits++;
400         bioq_init(&sc->bio_queue);
401         devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE,
402                 DEVSTAT_NO_ORDERED_TAGS, 
403                 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
404                 DEVSTAT_PRIORITY_OTHER);
405         sc->dev = disk_create(sc->unit, &sc->disk, &md_ops);
406         sc->dev->si_drv1 = sc;
407         sc->dev->si_iosize_max = MAXPHYS;
408         disk_setdisktype(&sc->disk, "memory");
409
410         bzero(&info, sizeof(info));
411         info.d_media_blksize = DEV_BSIZE;       /* mandatory */
412         info.d_media_blocks = length / DEV_BSIZE;
413
414         info.d_secpertrack = 1024;              /* optional */
415         info.d_nheads = 1;
416         info.d_secpercyl = info.d_secpertrack * info.d_nheads;
417         info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl);
418         disk_setdiskinfo(&sc->disk, &info);
419         TAILQ_INSERT_HEAD(&mdlist, sc, link);
420
421         return (sc);
422 }
423
424
425 static void
426 mdcreate_preload(u_char *image, unsigned length)
427 {
428         struct md_s *sc;
429
430         sc = mdcreate(length);
431         sc->type = MD_PRELOAD;
432         sc->nsect = length / DEV_BSIZE;
433         sc->pl_ptr = image;
434         sc->pl_len = length;
435
436         if (sc->unit == 0) 
437                 mdrootready = 1;
438 }
439
440 static void
441 mdcreate_malloc(void)
442 {
443         struct md_s *sc;
444
445         sc = mdcreate(MD_NSECT*DEV_BSIZE);
446         sc->type = MD_MALLOC;
447
448         sc->nsect = MD_NSECT;   /* for now */
449         sc->secp = kmalloc(sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
450         sc->nsecp = 1;
451         kprintf("md%d: Malloc disk\n", sc->unit);
452 }
453
454 static int
455 md_drvcleanup(void)
456 {
457
458         int secno;
459         struct md_s *sc, *sc_temp;
460
461         if (atomic_fetchadd_int(&refcnt, 0) != 0)
462                 return EBUSY;
463
464         /*
465          * Go through all the md devices, freeing up all the
466          * memory allocated for sectors, and the md_s struct
467          * itself.
468          */
469         TAILQ_FOREACH_MUTABLE(sc, &mdlist, link, sc_temp) {
470                 for (secno = 0; secno < sc->nsecp; secno++) {
471                         if ((u_int)(uintptr_t)sc->secp[secno] > 255)
472                                 kfree(sc->secp[secno], M_MDSECT);
473                 }
474
475                 if (sc->dev != NULL)
476                         disk_destroy(&sc->disk);
477
478                 devstat_remove_entry(&sc->stats);
479                 TAILQ_REMOVE(&mdlist, sc, link);
480
481                 kfree(sc->secp, M_MD);
482                 kfree(sc, M_MD);
483         }
484
485         return 0;
486
487 }
488
489 static void
490 md_drvinit(void *unused)
491 {
492
493         caddr_t mod;
494         caddr_t c;
495         u_char *ptr, *name, *type;
496         unsigned len;
497
498 #ifdef MD_ROOT_SIZE
499         mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
500 #endif
501         mod = NULL;
502         while ((mod = preload_search_next_name(mod)) != NULL) {
503                 name = (char *)preload_search_info(mod, MODINFO_NAME);
504                 type = (char *)preload_search_info(mod, MODINFO_TYPE);
505                 if (name == NULL)
506                         continue;
507                 if (type == NULL)
508                         continue;
509                 if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
510                         continue;
511                 c = preload_search_info(mod, MODINFO_ADDR);
512                 ptr = *(u_char **)c;
513                 c = preload_search_info(mod, MODINFO_SIZE);
514                 len = *(unsigned *)c;
515                 kprintf("md%d: Preloaded image <%s> %d bytes at %p\n",
516                    mdunits, name, len, ptr);
517                 mdcreate_preload(ptr, len);
518         } 
519         mdcreate_malloc();
520 }
521
522 DEV_MODULE(md, mdinit, NULL);
523
524 #ifdef MD_ROOT
525 static void
526 md_takeroot(void *junk)
527 {
528         if (mdrootready)
529                 rootdevnames[0] = "ufs:/dev/md0s0";
530 }
531
532 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
533 #endif