xref: /netbsd-src/sys/arch/amiga/dev/fd.c (revision bada23909e740596d0a3785a73bd3583a9807fb8)
1 /*	$NetBSD: fd.c,v 1.40 1998/01/12 10:39:26 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Christian E. Hopps
5  * Copyright (c) 1996 Ezra Story
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Christian E. Hopps.
19  *      This product includes software developed by Ezra Story.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/buf.h>
39 #include <sys/device.h>
40 #include <sys/ioctl.h>
41 #include <sys/fcntl.h>
42 #include <sys/disklabel.h>
43 #include <sys/disk.h>
44 #include <sys/dkbad.h>
45 #include <sys/proc.h>
46 #include <machine/cpu.h>
47 #include <amiga/amiga/device.h>
48 #include <amiga/amiga/custom.h>
49 #include <amiga/amiga/cia.h>
50 #include <amiga/amiga/cc.h>
51 
52 #include <sys/conf.h>
53 #include <machine/conf.h>
54 
55 #include "locators.h"
56 
57 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY };
58 /*
59  * partitions in fd represent different format floppies
60  * partition a is 0 etc..
61  */
62 enum fd_parttypes {
63 	FDAMIGAPART = 0,
64 	FDMSDOSPART,
65 	FDMAXPARTS
66 };
67 
68 #define FDBBSIZE	(8192)
69 #define FDSBSIZE	(8192)
70 
71 #define b_cylin	b_resid
72 #define FDUNIT(dev)	DISKUNIT(dev)
73 #define FDPART(dev)	DISKPART(dev)
74 #define FDMAKEDEV(m, u, p)	MAKEDISKDEV((m), (u), (p))
75 
76 /* that's nice, but we don't want to always use this as an amiga drive
77 bunghole :-) */
78 #define FDNHEADS	(2)	/* amiga drives always have 2 heads */
79 #define FDSECSIZE	(512)	/* amiga drives always have 512 byte sectors */
80 #define FDSECLWORDS	(128)
81 
82 #define FDSETTLEDELAY	(18000)	/* usec delay after seeking after switch dir */
83 #define FDSTEPDELAY	(3500)	/* usec delay after steping */
84 #define FDPRESIDEDELAY	(1000)	/* usec delay before writing can occur */
85 #define FDWRITEDELAY	(1300)	/* usec delay after write */
86 
87 #define FDSTEPOUT	(1)	/* decrease track step */
88 #define FDSTEPIN	(0)	/* increase track step */
89 
90 #define FDCUNITMASK	(0x78)	/* mask for all units (bits 6-3) */
91 
92 #define FDRETRIES	(2)	/* default number of retries */
93 #define FDMAXUNITS	(4)	/* maximum number of supported units */
94 
95 #define DISKLEN_READ	(0)	/* fake mask for reading */
96 #define DISKLEN_WRITE	(1 << 14)	/* bit for writing */
97 #define DISKLEN_DMAEN	(1 << 15)	/* dma go */
98 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2)	/* largest dma possible */
99 
100 #define FDMFMSYNC	(0x4489)
101 #define FDMFMID		(0x5554)
102 #define FDMFMDATA	(0x5545)
103 #define FDMFMGAP1	(0x9254)
104 #define FDMFMGAP2	(0xAAAA)
105 #define FDMFMGAP3	(0x9254)
106 #define CRC16POLY	(0x1021) /* (x^16) + x^12 + x^5 + x^0 */
107 
108 /*
109  * Msdos-type MFM encode/decode
110  */
111 static u_char msdecode[128];
112 static u_char msencode[16] =
113 {
114     0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
115     0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
116 };
117 static u_short mscrctab[256];
118 
119 /*
120   5554    aaaa    aaaa    aaa5    2aa4    4452    aa51
121           00      00      03      02      ac      0d
122 */
123 
124 /*
125  * floppy device type
126  */
127 struct fdtype {
128 	u_int driveid;		/* drive identification (from drive) */
129 	u_int ncylinders;	/* number of cylinders on drive */
130 	u_int amiga_nsectors;	/* number of sectors per amiga track */
131 	u_int msdos_nsectors;	/* number of sectors per msdos track */
132 	u_int nreadw;		/* number of words (short) read per track */
133 	u_int nwritew;		/* number of words (short) written per track */
134 	u_int gap;		/* track gap size in long words */
135 	u_int precomp[2];	/* 1st and 2nd precomp values */
136 	char *desc;		/* description of drive type (useq) */
137 };
138 
139 /*
140  * floppy disk device data
141  */
142 struct fd_softc {
143 	struct device sc_dv;	/* generic device info; must come first */
144 	struct disk dkdev;	/* generic disk info */
145 	struct buf bufq;	/* queue of buf's */
146 	struct fdtype *type;
147 	void *cachep;		/* cached track data (write through) */
148 	int cachetrk;		/* cahced track -1 for none */
149 	int hwunit;		/* unit for amiga controlling hw */
150 	int unitmask;		/* mask for cia select deslect */
151 	int pstepdir;		/* previous step direction */
152 	int curcyl;		/* current curcyl head positioned on */
153 	int flags;		/* misc flags */
154 	int wlabel;
155 	int stepdelay;		/* useq to delay after seek user setable */
156 	int nsectors;		/* number of sectors per track */
157 	int openpart;		/* which partition [ab] == [12] is open */
158 	short retries;		/* number of times to retry failed io */
159 	short retried;		/* number of times current io retried */
160 	int bytespersec;	/* number of bytes per sector */
161 };
162 
163 /* fd_softc->flags */
164 #define FDF_MOTORON	(0x01)	/* motor is running */
165 #define FDF_MOTOROFF	(0x02)	/* motor is waiting to be turned off */
166 #define FDF_WMOTOROFF	(0x04)	/* unit wants a wakeup after off */
167 #define FDF_DIRTY	(0x08)	/* track cache needs write */
168 #define FDF_WRITEWAIT	(0x10)	/* need to head select delay on next setpos */
169 #define FDF_HAVELABEL	(0x20)	/* label is valid */
170 #define FDF_JUSTFLUSH	(0x40)	/* don't bother caching track. */
171 #define FDF_NOTRACK0	(0x80)	/* was not able to recalibrate drive */
172 
173 int fdc_wantwakeup;
174 int fdc_side;
175 void  *fdc_dmap;
176 struct fd_softc *fdc_indma;
177 int fdc_dmalen;
178 int fdc_dmawrite;
179 
180 struct fdcargs {
181 	struct fdtype *type;
182 	int unit;
183 };
184 
185 int	fdcmatch __P((struct device *, struct cfdata *, void *));
186 void	fdcattach __P((struct device *, struct device *, void *));
187 int	fdcprint __P((void *, const char *));
188 int	fdmatch __P((struct device *, struct cfdata *, void *));
189 void	fdattach __P((struct device *, struct device *, void *));
190 
191 void	fdintr __P((int));
192 void	fdidxintr __P((void));
193 void	fdstrategy __P((struct buf *));
194 int	fdloaddisk __P((struct fd_softc *));
195 void	fdgetdefaultlabel __P((struct fd_softc *, struct disklabel *, int));
196 int	fdgetdisklabel __P((struct fd_softc *, dev_t));
197 int	fdsetdisklabel __P((struct fd_softc *, struct disklabel *));
198 int	fdputdisklabel __P((struct fd_softc *, dev_t));
199 struct	fdtype * fdcgetfdtype __P((int));
200 void	fdmotoroff __P((void *));
201 void	fdsetpos __P((struct fd_softc *, int, int));
202 void	fdselunit __P((struct fd_softc *));
203 void	fdstart __P((struct fd_softc *));
204 void	fdcont __P((struct fd_softc *));
205 void	fddmastart __P((struct fd_softc *, int));
206 void	fdcalibrate __P((void *));
207 void	fddmadone __P((struct fd_softc *, int));
208 void	fddone __P((struct fd_softc *));
209 void	fdfindwork __P((int));
210 void	fdminphys __P((struct buf *));
211 void	fdcachetoraw __P((struct fd_softc *));
212 void	amcachetoraw __P((struct fd_softc *));
213 int	amrawtocache __P((struct fd_softc *));
214 u_long	*fdfindsync __P((u_long *, u_long *));
215 int	fdrawtocache __P((struct fd_softc *));
216 void	mscachetoraw __P((struct fd_softc *));
217 int	msrawtocache __P((struct fd_softc *));
218 u_long	*mfmblkencode __P((u_long *, u_long *, u_long *, int));
219 u_long	*mfmblkdecode __P((u_long *, u_long *, u_long *, int));
220 u_short	*msblkdecode __P((u_short *, u_char *, int));
221 u_short	*msblkencode __P((u_short *, u_char *, int, u_short *));
222 
223 struct dkdriver fddkdriver = { fdstrategy };
224 
225 /*
226  * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts
227  * write size is nsectors * mfm secsize + gap bytes + 3 shorts
228  * the extra shorts are to deal with a dma hw bug in the controller
229  * they are probably too much (I belive the bug is 1 short on write and
230  * 3 bits on read) but there is no need to be cheap here.
231  */
232 #define MAXTRKSZ (22 * FDSECSIZE)
233 struct fdtype fdtype[] = {
234 	{ 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" },
235 	{ 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" },
236 	{ 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" }
237 };
238 int nfdtype = sizeof(fdtype) / sizeof(*fdtype);
239 
240 struct cfattach fd_ca = {
241 	sizeof(struct fd_softc), fdmatch, fdattach
242 };
243 
244 extern struct cfdriver fd_cd;
245 
246 struct cfattach fdc_ca = {
247 	sizeof(struct device), fdcmatch, fdcattach
248 };
249 
250 /*
251  * all hw access through macros, this helps to hide the active low
252  * properties
253  */
254 
255 #define FDUNITMASK(unit)	(1 << (3 + (unit)))
256 
257 /*
258  * select units using mask
259  */
260 #define FDSELECT(um)	do { ciab.prb &= ~(um); } while (0)
261 
262 /*
263  * deselect units using mask
264  */
265 #define FDDESELECT(um)	do { ciab.prb |= (um); delay(1); } while (0)
266 
267 /*
268  * test hw condition bits
269  */
270 #define FDTESTC(bit)	((ciaa.pra & (1 << (bit))) == 0)
271 
272 /*
273  * set motor for select units, true motor on else off
274  */
275 #define FDSETMOTOR(on)	do { \
276 	if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
277 	} while (0)
278 
279 /*
280  * set head for select units
281  */
282 #define FDSETHEAD(head)	do { \
283 	if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
284 	delay(1); } while (0)
285 
286 /*
287  * select direction, true towards spindle else outwards
288  */
289 #define FDSETDIR(in)	do { \
290 	if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
291 	delay(1); } while (0)
292 
293 /*
294  * step the selected units
295  */
296 #define FDSTEP	do { \
297     ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
298     } while (0)
299 
300 #define FDDMASTART(len, towrite)	do { \
301     int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
302     custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
303 
304 #define FDDMASTOP	do { custom.dsklen = 0; } while (0)
305 
306 
307 int
308 fdcmatch(pdp, cfp, auxp)
309 	struct device *pdp;
310 	struct cfdata *cfp;
311 	void *auxp;
312 {
313 
314 	if (matchname("fdc", auxp) == 0 || cfp->cf_unit != 0)
315 		return(0);
316 	if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
317 		printf("fdc: unable to allocate dma buffer\n");
318 		return(0);
319 	}
320 	return(1);
321 }
322 
323 void
324 fdcattach(pdp, dp, auxp)
325 	struct device *pdp,  *dp;
326 	void *auxp;
327 {
328 	struct fdcargs args;
329 
330 	printf(": dmabuf pa 0x%x", kvtop(fdc_dmap));
331 	printf(": dmabuf ka %p\n", fdc_dmap);
332 	args.unit = 0;
333 	args.type = fdcgetfdtype(args.unit);
334 
335 	fdc_side = -1;
336 	config_found(dp, &args, fdcprint);
337 	for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
338 		if ((args.type = fdcgetfdtype(args.unit)) == NULL)
339 			continue;
340 		config_found(dp, &args, fdcprint);
341 	}
342 }
343 
344 int
345 fdcprint(auxp, pnp)
346 	void *auxp;
347 	const char *pnp;
348 {
349 	struct fdcargs *fcp;
350 
351 	fcp = auxp;
352 	if (pnp)
353 		printf("fd%d at %s unit %d:", fcp->unit, pnp,
354 			fcp->type->driveid);
355 	return(UNCONF);
356 }
357 
358 /*ARGSUSED*/
359 int
360 fdmatch(pdp, cfp, auxp)
361 	struct device *pdp;
362 	struct cfdata *cfp;
363 	void *auxp;
364 {
365 
366 #define cf_unit	cf_loc[FDCCF_UNIT]
367 	struct fdcargs *fdap;
368 
369 	fdap = auxp;
370 	if (cfp->cf_unit == fdap->unit || cfp->cf_unit == FDCCF_UNIT_DEFAULT)
371 		return(1);
372 	return(0);
373 #undef cf_unit
374 }
375 
376 void
377 fdattach(pdp, dp, auxp)
378 	struct device *pdp, *dp;
379 	void *auxp;
380 {
381 	struct fdcargs *ap;
382 	struct fd_softc *sc;
383 	int i;
384 
385 	ap = auxp;
386 	sc = (struct fd_softc *)dp;
387 
388 	sc->curcyl = sc->cachetrk = -1;
389 	sc->openpart = -1;
390 	sc->type = ap->type;
391 	sc->hwunit = ap->unit;
392 	sc->unitmask = 1 << (3 + ap->unit);
393 	sc->retries = FDRETRIES;
394 	sc->stepdelay = FDSTEPDELAY;
395 	sc->bytespersec = 512;
396 	printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
397 	    sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
398 	    sc->type->amiga_nsectors, sc->type->msdos_nsectors);
399 
400 	/*
401 	 * Initialize and attach the disk structure.
402 	 */
403 	sc->dkdev.dk_name = sc->sc_dv.dv_xname;
404 	sc->dkdev.dk_driver = &fddkdriver;
405 	disk_attach(&sc->dkdev);
406 
407 	/*
408 	 * calibrate the drive
409 	 */
410 	fdsetpos(sc, 0, 0);
411 	fdsetpos(sc, sc->type->ncylinders, 0);
412 	fdsetpos(sc, 0, 0);
413 	fdmotoroff(sc);
414 
415 	/*
416 	 * precalc msdos MFM and CRC
417 	 */
418 	for (i = 0; i < 128; i++)
419 		msdecode[i] = 0xff;
420 	for (i = 0; i < 16; i++)
421 		msdecode[msencode[i]] = i;
422 	for (i = 0; i < 256; i++) {
423 		mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
424 		    (0x1021 * (i >> 4));
425 	}
426 
427 	/*
428 	 * enable disk related interrupts
429 	 */
430 	custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
431 	custom.intena = INTF_SETCLR | INTF_DSKBLK;
432 	ciab.icr = CIA_ICR_FLG;
433 }
434 
435 /*ARGSUSED*/
436 int
437 fdopen(dev, flags, devtype, p)
438 	dev_t dev;
439 	int flags, devtype;
440 	struct proc *p;
441 {
442 	struct fd_softc *sc;
443 	int wasopen, fwork, error, s;
444 
445 	error = 0;
446 
447 	if (FDPART(dev) >= FDMAXPARTS)
448 		return(ENXIO);
449 
450 	if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
451 		return(ENXIO);
452 	if (sc->flags & FDF_NOTRACK0)
453 		return(ENXIO);
454 	if (sc->cachep == NULL)
455 		sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
456 
457 	s = splbio();
458 	/*
459 	 * if we are sleeping in fdclose(); waiting for a chance to
460 	 * shut the motor off, do a sleep here also.
461 	 */
462 	while (sc->flags & FDF_WMOTOROFF)
463 		tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
464 
465 	fwork = 0;
466 	/*
467 	 * if not open let user open request type, otherwise
468 	 * ensure they are trying to open same type.
469 	 */
470 	if (sc->openpart == FDPART(dev))
471 		wasopen = 1;
472 	else if (sc->openpart == -1) {
473 		sc->openpart = FDPART(dev);
474 		wasopen = 0;
475 	} else {
476 		wasopen = 1;
477 		error = EPERM;
478 		goto done;
479 	}
480 
481 	/*
482 	 * wait for current io to complete if any
483 	 */
484 	if (fdc_indma) {
485 		fwork = 1;
486 		fdc_wantwakeup++;
487 		tsleep(fdopen, PRIBIO, "fdopen", 0);
488 	}
489 	if ((error = fdloaddisk(sc)) != 0)
490 		goto done;
491 	if ((error = fdgetdisklabel(sc, dev)) != 0)
492 		goto done;
493 #ifdef FDDEBUG
494 	printf("  open successful\n");
495 #endif
496 done:
497 	/*
498 	 * if we requested that fddone()->fdfindwork() wake us, allow it to
499 	 * complete its job now
500 	 */
501 	if (fwork)
502 		fdfindwork(FDUNIT(dev));
503 	splx(s);
504 
505 	/*
506 	 * if we were not open and we marked us so reverse that.
507 	 */
508 	if (error && wasopen == 0)
509 		sc->openpart = -1;
510 	return(error);
511 }
512 
513 /*ARGSUSED*/
514 int
515 fdclose(dev, flags, devtype, p)
516 	dev_t dev;
517 	int flags, devtype;
518 	struct proc *p;
519 {
520 	struct fd_softc *sc;
521 	int s;
522 
523 #ifdef FDDEBUG
524 	printf("fdclose()\n");
525 #endif
526 	sc = getsoftc(fd_cd, FDUNIT(dev));
527 	s = splbio();
528 	if (sc->flags & FDF_MOTORON) {
529 		sc->flags |= FDF_WMOTOROFF;
530 		tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
531 		sc->flags &= ~FDF_WMOTOROFF;
532 		wakeup(fdmotoroff);
533 	}
534 	sc->openpart = -1;
535 	splx(s);
536 	return(0);
537 }
538 
539 int
540 fdioctl(dev, cmd, addr, flag, p)
541 	dev_t dev;
542 	u_long cmd;
543 	caddr_t addr;
544 	int flag;
545 	struct proc *p;
546 {
547 	struct fd_softc *sc;
548 	int error, wlab;
549 
550 	sc = getsoftc(fd_cd, FDUNIT(dev));
551 
552 	if ((sc->flags & FDF_HAVELABEL) == 0)
553 		return(EBADF);
554 
555 	switch (cmd) {
556 	case DIOCSBAD:
557 		return(EINVAL);
558 	case DIOCSRETRIES:
559 		if (*(int *)addr < 0)
560 			return(EINVAL);
561 		sc->retries = *(int *)addr;
562 		return(0);
563 	case DIOCSSTEP:
564 		if (*(int *)addr < FDSTEPDELAY)
565 			return(EINVAL);
566 		sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
567 		return(0);
568 	case DIOCGDINFO:
569 		*(struct disklabel *)addr = *(sc->dkdev.dk_label);
570 		return(0);
571 	case DIOCGPART:
572 		((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
573 		((struct partinfo *)addr)->part =
574 		    &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
575 		return(0);
576 	case DIOCSDINFO:
577 		if ((flag & FWRITE) == 0)
578 			return(EBADF);
579 		return(fdsetdisklabel(sc, (struct disklabel *)addr));
580 	case DIOCWDINFO:
581 		if ((flag & FWRITE) == 0)
582 			return(EBADF);
583 		if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
584 			return(error);
585 		wlab = sc->wlabel;
586 		sc->wlabel = 1;
587 		error = fdputdisklabel(sc, dev);
588 		sc->wlabel = wlab;
589 		return(error);
590 	case DIOCWLABEL:
591 		if ((flag & FWRITE) == 0)
592 			return(EBADF);
593 		sc->wlabel = *(int *)addr;
594 		return(0);
595 	case DIOCGDEFLABEL:
596 		fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
597 		return(0);
598 	default:
599 		return(ENOTTY);
600 	}
601 }
602 
603 /*
604  * no dumps to floppy disks thank you.
605  */
606 int
607 fdsize(dev)
608 	dev_t dev;
609 {
610 	return(-1);
611 }
612 
613 int
614 fdread(dev, uio, flags)
615 	dev_t	dev;
616 	struct	uio *uio;
617 	int	flags;
618 {
619 	return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
620 }
621 
622 int
623 fdwrite(dev, uio, flags)
624 	dev_t	dev;
625 	struct	uio *uio;
626 	int	flags;
627 {
628 	return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
629 }
630 
631 
632 void
633 fdintr(flag)
634 	int	flag;
635 {
636 	int s;
637 
638 	s = splbio();
639 	if (fdc_indma)
640 		fddmadone(fdc_indma, 0);
641 	splx(s);
642 }
643 
644 void
645 fdidxintr()
646 {
647 	if (fdc_indma && fdc_dmalen) {
648 		/*
649 		 * turn off intr and start actual dma
650 		 */
651 		ciab.icr = CIA_ICR_FLG;
652 		FDDMASTART(fdc_dmalen, fdc_dmawrite);
653 		fdc_dmalen = 0;
654 	}
655 }
656 
657 void
658 fdstrategy(bp)
659 	struct buf *bp;
660 {
661 	struct disklabel *lp;
662 	struct fd_softc *sc;
663 	struct buf *dp;
664 	int unit, part, s;
665 
666 	unit = FDUNIT(bp->b_dev);
667 	part = FDPART(bp->b_dev);
668 	sc = getsoftc(fd_cd, unit);
669 
670 #ifdef FDDEBUG
671 	printf("fdstrategy: 0x%x\n", bp);
672 #endif
673 	/*
674 	 * check for valid partition and bounds
675 	 */
676 	lp = sc->dkdev.dk_label;
677 	if ((sc->flags & FDF_HAVELABEL) == 0) {
678 		bp->b_error = EIO;
679 		goto bad;
680 	}
681 	if (bounds_check_with_label(bp, lp, sc->wlabel) <= 0)
682 		goto done;
683 
684 	/*
685 	 * trans count of zero or bounds check indicates io is done
686 	 * we are done.
687 	 */
688 	if (bp->b_bcount == 0)
689 		goto done;
690 
691 	/*
692 	 * queue the buf and kick the low level code
693 	 */
694 	s = splbio();
695 	dp = &sc->bufq;
696 	disksort(dp, bp);
697 	fdstart(sc);
698 	splx(s);
699 	return;
700 bad:
701 	bp->b_flags |= B_ERROR;
702 done:
703 	bp->b_resid = bp->b_bcount;
704 	biodone(bp);
705 }
706 
707 /*
708  * make sure disk is loaded and label is up-to-date.
709  */
710 int
711 fdloaddisk(sc)
712 	struct fd_softc *sc;
713 {
714 	/*
715 	 * if diskchange is low step drive to 0 then up one then to zero.
716 	 */
717 	fdselunit(sc);			/* make sure the unit is selected */
718 	if (FDTESTC(FDB_CHANGED)) {
719 		fdsetpos(sc, 0, 0);
720 		sc->cachetrk = -1;		/* invalidate the cache */
721 		sc->flags &= ~FDF_HAVELABEL;
722 		fdsetpos(sc, FDNHEADS, 0);
723 		fdsetpos(sc, 0, 0);
724 		if (FDTESTC(FDB_CHANGED)) {
725 			fdmotoroff(sc);
726 			FDDESELECT(sc->unitmask);
727 			return(ENXIO);
728 		}
729 	}
730 	FDDESELECT(sc->unitmask);
731 	fdmotoroff(sc);
732 	sc->type = fdcgetfdtype(sc->hwunit);
733 	if (sc->type == NULL)
734 		return(ENXIO);
735 	if (sc->openpart == FDMSDOSPART)
736 		sc->nsectors = sc->type->msdos_nsectors;
737 	else
738 		sc->nsectors = sc->type->amiga_nsectors;
739 	return(0);
740 }
741 
742 void
743 fdgetdefaultlabel(sc, lp, part)
744 	struct fd_softc *sc;
745 	struct disklabel *lp;
746 	int part;		/* XXX ick */
747 {
748 
749 	bzero(lp, sizeof(struct disklabel));
750 	lp->d_secsize = FDSECSIZE;
751 	lp->d_ntracks = FDNHEADS;
752 	lp->d_ncylinders = sc->type->ncylinders;
753 	lp->d_nsectors = sc->nsectors;
754 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
755 	lp->d_type = DTYPE_FLOPPY;
756 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
757 	lp->d_rpm = 300; 		/* good guess I suppose. */
758 	lp->d_interleave = 1;		/* should change when adding msdos */
759 	sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
760 	lp->d_bbsize = 0;
761 	lp->d_sbsize = 0;
762 	lp->d_partitions[part].p_size = lp->d_secperunit;
763 	lp->d_partitions[part].p_fstype = FS_UNUSED;
764 	lp->d_partitions[part].p_fsize = 1024;
765 	lp->d_partitions[part].p_frag = 8;
766 	lp->d_partitions[part].p_cpg = 2;	/* adosfs: reserved blocks */
767 	lp->d_npartitions = part + 1;
768 	lp->d_magic = lp->d_magic2 = DISKMAGIC;
769 	lp->d_checksum = dkcksum(lp);
770 }
771 
772 /*
773  * read disk label, if present otherwise create one
774  * return a new label if raw part and none found, otherwise err.
775  */
776 int
777 fdgetdisklabel(sc, dev)
778 	struct fd_softc *sc;
779 	dev_t dev;
780 {
781 	struct disklabel *lp, *dlp;
782 	struct cpu_disklabel *clp;
783 	struct buf *bp;
784 	int error, part;
785 
786 	if (sc->flags & FDF_HAVELABEL &&
787 	    sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
788 		return(0);
789 #ifdef FDDEBUG
790 	printf("fdgetdisklabel()\n");
791 #endif
792 	part = FDPART(dev);
793 	lp = sc->dkdev.dk_label;
794 	clp =  sc->dkdev.dk_cpulabel;
795 	bzero(lp, sizeof(struct disklabel));
796 	bzero(clp, sizeof(struct cpu_disklabel));
797 
798 	lp->d_secsize = FDSECSIZE;
799 	lp->d_ntracks = FDNHEADS;
800 	lp->d_ncylinders = sc->type->ncylinders;
801 	lp->d_nsectors = sc->nsectors;
802 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
803 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
804 	lp->d_npartitions = part + 1;
805 	lp->d_partitions[part].p_size = lp->d_secperunit;
806 	lp->d_partitions[part].p_fstype = FS_UNUSED;
807 	lp->d_partitions[part].p_fsize = 1024;
808 	lp->d_partitions[part].p_frag = 8;
809 	lp->d_partitions[part].p_cpg = 2;	/* for adosfs: reserved blks */
810 
811 	sc->flags |= FDF_HAVELABEL;
812 
813 	bp = (void *)geteblk((int)lp->d_secsize);
814 	bp->b_dev = dev;
815 	bp->b_blkno = 0;
816 	bp->b_cylin = 0;
817 	bp->b_bcount = FDSECSIZE;
818 	bp->b_flags = B_BUSY | B_READ;
819 	fdstrategy(bp);
820 	if ((error = biowait(bp)) != 0)
821 		goto nolabel;
822 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
823 	if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
824 	    dkcksum(dlp)) {
825 		error = EINVAL;
826 		goto nolabel;
827 	}
828 	bcopy(dlp, lp, sizeof(struct disklabel));
829 	if (lp->d_trkseek > FDSTEPDELAY)
830 		sc->stepdelay = lp->d_trkseek;
831 	brelse(bp);
832 	return(0);
833 nolabel:
834 	fdgetdefaultlabel(sc, lp, part);
835 	brelse(bp);
836 	return(0);
837 }
838 
839 /*
840  * set the incore copy of this units disklabel
841  */
842 int
843 fdsetdisklabel(sc, lp)
844 	struct fd_softc *sc;
845 	struct disklabel *lp;
846 {
847 	struct disklabel *clp;
848 	struct partition *pp;
849 
850 	/*
851 	 * must have at least opened raw unit to fetch the
852 	 * raw_part stuff.
853 	 */
854 	if ((sc->flags & FDF_HAVELABEL) == 0)
855 		return(EINVAL);
856 	clp = sc->dkdev.dk_label;
857 	/*
858 	 * make sure things check out and we only have one valid
859 	 * partition
860 	 */
861 #ifdef FDDEBUG
862 	printf("fdsetdisklabel\n");
863 #endif
864 	if (lp->d_secsize != FDSECSIZE ||
865 	    lp->d_nsectors != clp->d_nsectors ||
866 	    lp->d_ntracks != FDNHEADS ||
867 	    lp->d_ncylinders != clp->d_ncylinders ||
868 	    lp->d_secpercyl != clp->d_secpercyl ||
869 	    lp->d_secperunit != clp->d_secperunit ||
870 	    lp->d_magic != DISKMAGIC ||
871 	    lp->d_magic2 != DISKMAGIC ||
872 	    lp->d_npartitions == 0 ||
873 	    lp->d_npartitions > FDMAXPARTS ||
874 	    (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
875 	    dkcksum(lp))
876 		return(EINVAL);
877 	/*
878 	 * if any partitions are present make sure they
879 	 * represent the currently open type
880 	 */
881 	if ((pp = &lp->d_partitions[0])->p_size) {
882 		if ((pp = &lp->d_partitions[1])->p_size == 0)
883 			goto done;
884 		else if (sc->openpart != 1)
885 			return(EINVAL);
886 	} else if (sc->openpart != 0)
887 		return(EINVAL);
888 	/*
889 	 * make sure selected partition is within bounds
890 	 * XXX on the second check, its to handle a bug in
891 	 * XXX the cluster routines as they require mutliples
892 	 * XXX of CLBYTES currently
893 	 */
894 	if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
895 	    (pp->p_frag * pp->p_fsize % CLBYTES))
896 		return(EINVAL);
897 done:
898 	bcopy(lp, clp, sizeof(struct disklabel));
899 	return(0);
900 }
901 
902 /*
903  * write out the incore copy of this units disklabel
904  */
905 int
906 fdputdisklabel(sc, dev)
907 	struct fd_softc *sc;
908 	dev_t dev;
909 {
910 	struct disklabel *lp, *dlp;
911 	struct buf *bp;
912 	int error;
913 
914 	if ((sc->flags & FDF_HAVELABEL) == 0)
915 		return(EBADF);
916 #ifdef FDDEBUG
917 	printf("fdputdisklabel\n");
918 #endif
919 	/*
920 	 * get buf and read in sector 0
921 	 */
922 	lp = sc->dkdev.dk_label;
923 	bp = (void *)geteblk((int)lp->d_secsize);
924 	bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
925 	bp->b_blkno = 0;
926 	bp->b_cylin = 0;
927 	bp->b_bcount = FDSECSIZE;
928 	bp->b_flags = B_BUSY | B_READ;
929 	fdstrategy(bp);
930 	if ((error = biowait(bp)) != 0)
931 		goto done;
932 	/*
933 	 * copy disklabel to buf and write it out syncronous
934 	 */
935 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
936 	bcopy(lp, dlp, sizeof(struct disklabel));
937 	bp->b_blkno = 0;
938 	bp->b_cylin = 0;
939 	bp->b_flags = B_WRITE;
940 	fdstrategy(bp);
941 	error = biowait(bp);
942 done:
943 	brelse(bp);
944 	return(error);
945 }
946 
947 /*
948  * figure out drive type or NULL if none.
949  */
950 struct fdtype *
951 fdcgetfdtype(unit)
952 	int unit;
953 {
954 	struct fdtype *ftp;
955 	u_long id, idb;
956 	int cnt, umask;
957 
958 	id = 0;
959 	umask = 1 << (3 + unit);
960 
961 	FDDESELECT(FDCUNITMASK);
962 
963 	FDSETMOTOR(1);
964 	delay(1);
965 	FDSELECT(umask);
966 	delay(1);
967 	FDDESELECT(umask);
968 
969 	FDSETMOTOR(0);
970 	delay(1);
971 	FDSELECT(umask);
972 	delay(1);
973 	FDDESELECT(umask);
974 
975 	for (idb = 0x80000000; idb; idb >>= 1) {
976 		FDSELECT(umask);
977 		delay(1);
978 		if (FDTESTC(FDB_READY) == 0)
979 			id |= idb;
980 		FDDESELECT(umask);
981 		delay(1);
982 	}
983 #ifdef FDDEBUG
984 	printf("fdcgettype unit %d id 0x%lx\n", unit, id);
985 #endif
986 
987 	for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
988 		if (ftp->driveid == id)
989 			return(ftp);
990 	/*
991 	 * 3.5dd's at unit 0 do not always return id.
992 	 */
993 	if (unit == 0)
994 		return(fdtype);
995 	return(NULL);
996 }
997 
998 /*
999  * turn motor off if possible otherwise mark as needed and will be done
1000  * later.
1001  */
1002 void
1003 fdmotoroff(arg)
1004 	void *arg;
1005 {
1006 	struct fd_softc *sc;
1007 	int s;
1008 
1009 	sc = arg;
1010 	s = splbio();
1011 
1012 #ifdef FDDEBUG
1013 	printf("fdmotoroff: unit %d\n", sc->hwunit);
1014 #endif
1015 	if ((sc->flags & FDF_MOTORON) == 0)
1016 		goto done;
1017 	/*
1018 	 * if we have a timeout on a dma operation let fddmadone()
1019 	 * deal with it.
1020 	 */
1021 	if (fdc_indma == sc) {
1022 		fddmadone(sc, 1);
1023 		goto done;
1024 	}
1025 #ifdef FDDEBUG
1026 	printf(" motor was on, turning off\n");
1027 #endif
1028 
1029 	/*
1030 	 * flush cache if needed
1031 	 */
1032 	if (sc->flags & FDF_DIRTY) {
1033 		sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1034 #ifdef FDDEBUG
1035 		printf("  flushing dirty buffer first\n");
1036 #endif
1037 		/*
1038 		 * if dma'ing done for now, fddone() will call us again
1039 		 */
1040 		if (fdc_indma)
1041 			goto done;
1042 		fddmastart(sc, sc->cachetrk);
1043 		goto done;
1044 	}
1045 
1046 	/*
1047 	 * if controller is busy just schedule us to be called back
1048 	 */
1049 	if (fdc_indma) {
1050 		/*
1051 		 * someone else has the controller now
1052 		 * just set flag and let fddone() call us again.
1053 		 */
1054 		sc->flags |= FDF_MOTOROFF;
1055 		goto done;
1056 	}
1057 
1058 #ifdef FDDEBUG
1059 	printf("  hw turning unit off\n");
1060 #endif
1061 
1062 	sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1063 	FDDESELECT(FDCUNITMASK);
1064 	FDSETMOTOR(0);
1065 	delay(1);
1066 	FDSELECT(sc->unitmask);
1067 	delay(4);
1068 	FDDESELECT(sc->unitmask);
1069 	delay(1);
1070 	if (sc->flags & FDF_WMOTOROFF)
1071 		wakeup(fdmotoroff);
1072 done:
1073 	splx(s);
1074 }
1075 
1076 /*
1077  * select drive seek to track exit with motor on.
1078  * fdsetpos(x, 0, 0) does calibrates the drive.
1079  */
1080 void
1081 fdsetpos(sc, trk, towrite)
1082 	struct fd_softc *sc;
1083 	int trk, towrite;
1084 {
1085 	int nstep, sdir, ondly, ncyl, nside;
1086 
1087 	FDDESELECT(FDCUNITMASK);
1088 	FDSETMOTOR(1);
1089 	delay(1);
1090 	FDSELECT(sc->unitmask);
1091 	delay(1);
1092 	if ((sc->flags & FDF_MOTORON) == 0) {
1093 		ondly = 0;
1094 		while (FDTESTC(FDB_READY) == 0) {
1095 			delay(1000);
1096 			if (++ondly >= 1000)
1097 				break;
1098 		}
1099 	}
1100 	sc->flags |= FDF_MOTORON;
1101 
1102 	ncyl = trk / FDNHEADS;
1103 	nside = trk % FDNHEADS;
1104 
1105 	if (sc->curcyl == ncyl && fdc_side == nside)
1106 		return;
1107 
1108 	if (towrite)
1109 		sc->flags |= FDF_WRITEWAIT;
1110 
1111 #ifdef FDDEBUG
1112 	printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1113 	    trk % FDNHEADS, towrite);
1114 #endif
1115 	nstep = ncyl - sc->curcyl;
1116 	if (nstep) {
1117 		/*
1118 		 * figure direction
1119 		 */
1120 		if (nstep > 0 && ncyl != 0) {
1121 			sdir = FDSTEPIN;
1122 			FDSETDIR(1);
1123 		} else {
1124 			nstep = -nstep;
1125 			sdir = FDSTEPOUT;
1126 			FDSETDIR(0);
1127 		}
1128 		if (ncyl == 0) {
1129 			/*
1130 			 * either just want cylinder 0 or doing
1131 			 * a calibrate.
1132 			 */
1133 			nstep = 256;
1134 			while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1135 				FDSTEP;
1136 				delay(sc->stepdelay);
1137 			}
1138 			if (nstep < 0)
1139 				sc->flags |= FDF_NOTRACK0;
1140 		} else {
1141 			/*
1142 			 * step the needed amount amount.
1143 			 */
1144 			while (nstep--) {
1145 				FDSTEP;
1146 				delay(sc->stepdelay);
1147 			}
1148 		}
1149 		/*
1150 		 * if switched directions
1151 		 * allow drive to settle.
1152 		 */
1153 		if (sc->pstepdir != sdir)
1154 			delay(FDSETTLEDELAY);
1155 		sc->pstepdir = sdir;
1156 		sc->curcyl = ncyl;
1157 	}
1158 	if (nside == fdc_side)
1159 		return;
1160 	/*
1161 	 * select side
1162 	 */
1163 	fdc_side = nside;
1164 	FDSETHEAD(nside);
1165 	delay(FDPRESIDEDELAY);
1166 }
1167 
1168 void
1169 fdselunit(sc)
1170 	struct fd_softc *sc;
1171 {
1172 	FDDESELECT(FDCUNITMASK);		/* deselect all */
1173 	FDSETMOTOR(sc->flags & FDF_MOTORON);	/* set motor to unit's state */
1174 	delay(1);
1175 	FDSELECT(sc->unitmask);			/* select unit */
1176 	delay(1);
1177 }
1178 
1179 /*
1180  * process next buf on device queue.
1181  * normall sequence of events:
1182  * fdstart() -> fddmastart();
1183  * fdidxintr();
1184  * fdintr() -> fddmadone() -> fddone();
1185  * if the track is in the cache then fdstart() will short-circuit
1186  * to fddone() else if the track cache is dirty it will flush.  If
1187  * the buf is not an entire track it will cache the requested track.
1188  */
1189 void
1190 fdstart(sc)
1191 	struct fd_softc *sc;
1192 {
1193 	int trk, error, write;
1194 	struct buf *bp, *dp;
1195 	int changed;
1196 
1197 #ifdef FDDEBUG
1198 	printf("fdstart: unit %d\n", sc->hwunit);
1199 #endif
1200 
1201 	/*
1202 	 * if dma'ing just return. we must have been called from fdstartegy.
1203 	 */
1204 	if (fdc_indma)
1205 		return;
1206 
1207 	/*
1208 	 * get next buf if there.
1209 	 */
1210 	dp = &sc->bufq;
1211 	if ((bp = dp->b_actf) == NULL) {
1212 #ifdef FDDEBUG
1213 		printf("  nothing to do\n");
1214 #endif
1215 		return;
1216 	}
1217 
1218 	/*
1219 	 * Mark us as busy now, in case fddone() gets called in one
1220 	 * of the cases below.
1221 	 */
1222 	disk_busy(&sc->dkdev);
1223 
1224 	/*
1225 	 * make sure same disk is loaded
1226 	 */
1227 	fdselunit(sc);
1228 	changed = FDTESTC(FDB_CHANGED);
1229 	FDDESELECT(sc->unitmask);
1230 	if (changed) {
1231 		/*
1232 		 * disk missing, invalidate all future io on
1233 		 * this unit until re-open()'ed also invalidate
1234 		 * all current io
1235 		 */
1236 printf("fdstart: disk changed\n");
1237 #ifdef FDDEBUG
1238 		printf("  disk was removed invalidating all io\n");
1239 #endif
1240 		sc->flags &= ~FDF_HAVELABEL;
1241 		for (;;) {
1242 			bp->b_flags |= B_ERROR;
1243 			bp->b_error = EIO;
1244 			if (bp->b_actf == NULL)
1245 				break;
1246 			biodone(bp);
1247 			bp = bp->b_actf;
1248 		}
1249 		/*
1250 		 * do fddone() on last buf to allow other units to start.
1251 		 */
1252 		dp->b_actf = bp;
1253 		fddone(sc);
1254 		return;
1255 	}
1256 
1257 	/*
1258 	 * we have a valid buf, setup our local version
1259 	 * we use this count to allow reading over multiple tracks.
1260 	 * into a single buffer
1261 	 */
1262 	dp->b_bcount = bp->b_bcount;
1263 	dp->b_blkno = bp->b_blkno;
1264 	dp->b_data = bp->b_data;
1265 	dp->b_flags = bp->b_flags;
1266 	dp->b_resid = 0;
1267 
1268 	if (bp->b_flags & B_READ)
1269 		write = 0;
1270 	else if (FDTESTC(FDB_PROTECT) == 0)
1271 		write = 1;
1272 	else {
1273 		error = EPERM;
1274 		goto bad;
1275 	}
1276 
1277 	/*
1278 	 * figure trk given blkno
1279 	 */
1280 	trk = bp->b_blkno / sc->nsectors;
1281 
1282 	/*
1283 	 * check to see if same as currently cached track
1284 	 * if so we need to do no dma read.
1285 	 */
1286 	if (trk == sc->cachetrk) {
1287 		fddone(sc);
1288 		return;
1289 	}
1290 
1291 	/*
1292 	 * if we will be overwriting the entire cache, don't bother to
1293 	 * fetch it.
1294 	 */
1295 	if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1296 	    bp->b_blkno % sc->nsectors == 0) {
1297 		if (sc->flags & FDF_DIRTY)
1298 			sc->flags |= FDF_JUSTFLUSH;
1299 		else {
1300 			sc->cachetrk = trk;
1301 			fddone(sc);
1302 			return;
1303 		}
1304 	}
1305 
1306 	/*
1307 	 * start dma read of `trk'
1308 	 */
1309 	fddmastart(sc, trk);
1310 	return;
1311 bad:
1312 	bp->b_flags |= B_ERROR;
1313 	bp->b_error = error;
1314 	fddone(sc);
1315 }
1316 
1317 /*
1318  * continue a started operation on next track. always begin at
1319  * sector 0 on the next track.
1320  */
1321 void
1322 fdcont(sc)
1323 	struct fd_softc *sc;
1324 {
1325 	struct buf *dp, *bp;
1326 	int trk, write;
1327 
1328 	dp = &sc->bufq;
1329 	bp = dp->b_actf;
1330 	dp->b_data += (dp->b_bcount - bp->b_resid);
1331 	dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1332 	dp->b_bcount = bp->b_resid;
1333 
1334 	/*
1335 	 * figure trk given blkno
1336 	 */
1337 	trk = dp->b_blkno / sc->nsectors;
1338 #ifdef DEBUG
1339 	if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1340 		panic("fdcont: confused");
1341 #endif
1342 	if (dp->b_flags & B_READ)
1343 		write = 0;
1344 	else
1345 		write = 1;
1346 	/*
1347 	 * if we will be overwriting the entire cache, don't bother to
1348 	 * fetch it.
1349 	 */
1350 	if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1351 		if (sc->flags & FDF_DIRTY)
1352 			sc->flags |= FDF_JUSTFLUSH;
1353 		else {
1354 			sc->cachetrk = trk;
1355 			fddone(sc);
1356 			return;
1357 		}
1358 	}
1359 	/*
1360 	 * start dma read of `trk'
1361 	 */
1362 	fddmastart(sc, trk);
1363 	return;
1364 }
1365 
1366 void
1367 fddmastart(sc, trk)
1368 	struct fd_softc *sc;
1369 	int trk;
1370 {
1371 	int adkmask, ndmaw, write, dmatrk;
1372 
1373 #ifdef FDDEBUG
1374 	printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1375 	    trk / FDNHEADS, trk % FDNHEADS);
1376 #endif
1377 	/*
1378 	 * flush the cached track if dirty else read requested track.
1379 	 */
1380 	if (sc->flags & FDF_DIRTY) {
1381 		fdcachetoraw(sc);
1382 		ndmaw = sc->type->nwritew;
1383 		dmatrk = sc->cachetrk;
1384 		write = 1;
1385 	} else {
1386 		ndmaw = sc->type->nreadw;
1387 		dmatrk = trk;
1388 		write = 0;
1389 	}
1390 
1391 #ifdef FDDEBUG
1392 	printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1393 #endif
1394 	sc->cachetrk = trk;
1395 	fdc_indma = sc;
1396 	fdsetpos(sc, dmatrk, write);
1397 
1398 	/*
1399 	 * setup dma stuff
1400 	 */
1401 	if (write == 0) {
1402 		custom.adkcon = ADKF_MSBSYNC;
1403 		custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1404 		custom.dsksync = FDMFMSYNC;
1405 	} else {
1406 		custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1407 		    ADKF_MSBSYNC;
1408 		adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1409 		if (dmatrk >= sc->type->precomp[0])
1410 			adkmask |= ADKF_PRECOMP0;
1411 		if (dmatrk >= sc->type->precomp[1])
1412 			adkmask |= ADKF_PRECOMP1;
1413 		custom.adkcon = adkmask;
1414 	}
1415 	custom.dskpt = (u_char *)kvtop(fdc_dmap);
1416 
1417 	/*
1418 	 * If writing an MSDOS track, activate disk index pulse
1419 	 * interrupt, dma will be started in the intr routine fdidxintr()
1420 	 * Otherwise, start the DMA here.
1421 	 */
1422 	if (write && sc->openpart == FDMSDOSPART) {
1423 		fdc_dmalen = ndmaw;
1424 		fdc_dmawrite = write;
1425 		ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1426 	} else {
1427 		FDDMASTART(ndmaw, write);
1428 		fdc_dmalen = 0;
1429 	}
1430 
1431 #ifdef FDDEBUG
1432 	printf("  dma started\n");
1433 #endif
1434 }
1435 
1436 /*
1437  * recalibrate the drive
1438  */
1439 void
1440 fdcalibrate(arg)
1441 	void *arg;
1442 {
1443 	struct fd_softc *sc;
1444 	static int loopcnt;
1445 
1446 	sc = arg;
1447 
1448 	if (loopcnt == 0) {
1449 		/*
1450 		 * seek cyl 0
1451 		 */
1452 		fdc_indma = sc;
1453 		sc->stepdelay += 900;
1454 		if (sc->cachetrk > 1)
1455 			fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1456 		sc->stepdelay -= 900;
1457 	}
1458 	if (loopcnt++ & 1)
1459 		fdsetpos(sc, sc->cachetrk, 0);
1460 	else
1461 		fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1462 	/*
1463 	 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and dma
1464 	 */
1465 	if (loopcnt < 8)
1466 		timeout(fdcalibrate, sc, hz / 8);
1467 	else {
1468 		loopcnt = 0;
1469 		fdc_indma = NULL;
1470 		timeout(fdmotoroff, sc, 3 * hz / 2);
1471 		fddmastart(sc, sc->cachetrk);
1472 	}
1473 }
1474 
1475 void
1476 fddmadone(sc, timeo)
1477 	struct fd_softc *sc;
1478 	int timeo;
1479 {
1480 #ifdef FDDEBUG
1481 	printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1482 #endif
1483 	fdc_indma = NULL;
1484 	untimeout(fdmotoroff, sc);
1485 	FDDMASTOP;
1486 
1487 	/*
1488 	 * guarantee the drive has been at current head and cyl
1489 	 * for at least FDWRITEDELAY after a write.
1490 	 */
1491 	if (sc->flags & FDF_WRITEWAIT) {
1492 		delay(FDWRITEDELAY);
1493 		sc->flags &= ~FDF_WRITEWAIT;
1494 	}
1495 
1496 	if ((sc->flags & FDF_MOTOROFF) == 0) {
1497 		/*
1498 		 * motor runs for 1.5 seconds after last dma
1499 		 */
1500 		timeout(fdmotoroff, sc, 3 * hz / 2);
1501 	}
1502 	if (sc->flags & FDF_DIRTY) {
1503 		/*
1504 		 * if buffer dirty, the last dma cleaned it
1505 		 */
1506 		sc->flags &= ~FDF_DIRTY;
1507 		if (timeo)
1508 			printf("%s: write of track cache timed out.\n",
1509 			    sc->sc_dv.dv_xname);
1510 		if (sc->flags & FDF_JUSTFLUSH) {
1511 			sc->flags &= ~FDF_JUSTFLUSH;
1512 			/*
1513 			 * we are done dma'ing
1514 			 */
1515 			fddone(sc);
1516 			return;
1517 		}
1518 		/*
1519 		 * load the cache
1520 		 */
1521 		fddmastart(sc, sc->cachetrk);
1522 		return;
1523 	}
1524 #ifdef FDDEBUG
1525 	else if (sc->flags & FDF_MOTOROFF)
1526 		panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1527 #endif
1528 
1529 	/*
1530 	 * cache loaded decode it into cache buffer
1531 	 */
1532 	if (timeo == 0 && fdrawtocache(sc) == 0)
1533 		sc->retried = 0;
1534 	else {
1535 #ifdef FDDEBUG
1536 		if (timeo)
1537 			printf("%s: fddmadone: cache load timed out.\n",
1538 			    sc->sc_dv.dv_xname);
1539 #endif
1540 		if (sc->retried >= sc->retries) {
1541 			sc->retried = 0;
1542 			sc->cachetrk = -1;
1543 		} else {
1544 			sc->retried++;
1545 			/*
1546 			 * this will be restarted at end of calibrate loop.
1547 			 */
1548 			untimeout(fdmotoroff, sc);
1549 			fdcalibrate(sc);
1550 			return;
1551 		}
1552 	}
1553 	fddone(sc);
1554 }
1555 
1556 void
1557 fddone(sc)
1558 	struct fd_softc *sc;
1559 {
1560 	struct buf *dp, *bp;
1561 	char *data;
1562 	int sz;
1563 
1564 #ifdef FDDEBUG
1565 	printf("fddone: unit %d\n", sc->hwunit);
1566 #endif
1567 	/*
1568 	 * check to see if unit is just flushing the cache,
1569 	 * that is we have no io queued.
1570 	 */
1571 	if (sc->flags & FDF_MOTOROFF)
1572 		goto nobuf;
1573 
1574 	dp = &sc->bufq;
1575 	if ((bp = dp->b_actf) == NULL)
1576 		panic ("fddone");
1577 	/*
1578 	 * check for an error that may have occured
1579 	 * while getting the track.
1580 	 */
1581 	if (sc->cachetrk == -1) {
1582 		sc->retried = 0;
1583 		bp->b_flags |= B_ERROR;
1584 		bp->b_error = EIO;
1585 	} else if ((bp->b_flags & B_ERROR) == 0) {
1586 		data = sc->cachep;
1587 		/*
1588 		 * get offset of data in track cache and limit
1589 		 * the copy size to not exceed the cache's end.
1590 		 */
1591 		data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1592 		sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1593 		sz *= FDSECSIZE;
1594 		sz = min(dp->b_bcount, sz);
1595 		if (bp->b_flags & B_READ)
1596 			bcopy(data, dp->b_data, sz);
1597 		else {
1598 			bcopy(dp->b_data, data, sz);
1599 			sc->flags |= FDF_DIRTY;
1600 		}
1601 		bp->b_resid = dp->b_bcount - sz;
1602 		if (bp->b_resid == 0) {
1603 			bp->b_error = 0;
1604 		} else {
1605 			/*
1606 			 * not done yet need to read next track
1607 			 */
1608 			fdcont(sc);
1609 			return;
1610 		}
1611 	}
1612 	/*
1613 	 * remove from queue.
1614 	 */
1615 	dp->b_actf = bp->b_actf;
1616 
1617 	disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid));
1618 
1619 	biodone(bp);
1620 nobuf:
1621 	fdfindwork(sc->sc_dv.dv_unit);
1622 }
1623 
1624 void
1625 fdfindwork(unit)
1626 	int unit;
1627 {
1628 	struct fd_softc *ssc, *sc;
1629 	int i, last;
1630 
1631 	/*
1632 	 * first see if we have any fdopen()'s waiting
1633 	 */
1634 	if (fdc_wantwakeup) {
1635 		wakeup(fdopen);
1636 		fdc_wantwakeup--;
1637 		return;
1638 	}
1639 
1640 	/*
1641 	 * start next available unit, linear search from the next unit
1642 	 * wrapping and finally this unit.
1643 	 */
1644 	last = 0;
1645 	ssc = NULL;
1646 	for (i = unit + 1; last == 0; i++) {
1647 		if (i == unit)
1648 			last = 1;
1649 		if (i >= fd_cd.cd_ndevs) {
1650 			i = -1;
1651 			continue;
1652 		}
1653 		if ((sc = fd_cd.cd_devs[i]) == NULL)
1654 			continue;
1655 
1656 		/*
1657 		 * if unit has requested to be turned off
1658 		 * and it has no buf's queued do it now
1659 		 */
1660 		if (sc->flags & FDF_MOTOROFF) {
1661 			if (sc->bufq.b_actf == NULL)
1662 				fdmotoroff(sc);
1663 			else {
1664 				/*
1665 				 * we gained a buf request while
1666 				 * we waited, forget the motoroff
1667 				 */
1668 				sc->flags &= ~FDF_MOTOROFF;
1669 			}
1670 			/*
1671 			 * if we now have dma unit must have needed
1672 			 * flushing, quit
1673 			 */
1674 			if (fdc_indma)
1675 				return;
1676 		}
1677 		/*
1678 		 * if we have no start unit and the current unit has
1679 		 * io waiting choose this unit to start.
1680 		 */
1681 		if (ssc == NULL && sc->bufq.b_actf)
1682 			ssc = sc;
1683 	}
1684 	if (ssc)
1685 		fdstart(ssc);
1686 }
1687 
1688 /*
1689  * min byte count to whats left of the track in question
1690  */
1691 void
1692 fdminphys(bp)
1693 	struct buf *bp;
1694 {
1695 	struct fd_softc *sc;
1696 	int trk, sec, toff, tsz;
1697 
1698 	if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1699 		panic("fdminphys: couldn't get softc");
1700 
1701 	trk = bp->b_blkno / sc->nsectors;
1702 	sec = bp->b_blkno % sc->nsectors;
1703 
1704 	toff = sec * FDSECSIZE;
1705 	tsz = sc->nsectors * FDSECSIZE;
1706 #ifdef FDDEBUG
1707 	printf("fdminphys: before %d", bp->b_bcount);
1708 #endif
1709 	bp->b_bcount = min(bp->b_bcount, tsz - toff);
1710 #ifdef FDDEBUG
1711 	printf(" after %d\n", bp->b_bcount);
1712 #endif
1713 	minphys(bp);
1714 }
1715 
1716 /*
1717  * encode the track cache into raw MFM ready for dma
1718  * when we go to multiple disk formats, this will call type dependent
1719  * functions
1720  */
1721 void fdcachetoraw(sc)
1722 	struct fd_softc *sc;
1723 {
1724 	if (sc->openpart == FDMSDOSPART)
1725 		mscachetoraw(sc);
1726 	else
1727 		amcachetoraw(sc);
1728 }
1729 
1730 /*
1731  * decode raw MFM from dma into units track cache.
1732  * when we go to multiple disk formats, this will call type dependent
1733  * functions
1734  */
1735 int
1736 fdrawtocache(sc)
1737 	struct fd_softc *sc;
1738 {
1739 
1740 	if (sc->openpart == FDMSDOSPART)
1741 		return(msrawtocache(sc));
1742 	else
1743 		return(amrawtocache(sc));
1744 }
1745 
1746 void
1747 amcachetoraw(sc)
1748 	struct fd_softc *sc;
1749 {
1750 	static u_long mfmnull[4];
1751 	u_long *rp, *crp, *dp, hcksum, dcksum, info, zero;
1752 	int sec, i;
1753 
1754 	rp = fdc_dmap;
1755 
1756 	/*
1757 	 * not yet one sector (- 1 long) gap.
1758 	 * for now use previous drivers values
1759 	 */
1760 	for (i = 0; i < sc->type->gap; i++)
1761 		*rp++ = 0xaaaaaaaa;
1762 	/*
1763 	 * process sectors
1764 	 */
1765 	dp = sc->cachep;
1766 	zero = 0;
1767 	info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1768 	for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1769 		hcksum = dcksum = 0;
1770 		/*
1771 		 * sector format
1772 		 *	offset		description
1773 		 *-----------------------------------
1774 		 *  0			null
1775 		 *  1			sync
1776 		 * oddbits	evenbits
1777 		 *----------------------
1778 		 *  2		3	[0xff]b [trk]b [sec]b [togap]b
1779 		 *  4-7		8-11	null
1780 		 * 12		13	header cksum [2-11]
1781 		 * 14		15	data cksum [16-271]
1782 		 * 16-143	144-271	data
1783 		 */
1784 		*rp = 0xaaaaaaaa;
1785 		if (*(rp - 1) & 0x1)
1786 			*rp &= 0x7fffffff;	/* clock bit correction */
1787 		rp++;
1788 		*rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1789 		rp = mfmblkencode(&info, rp, &hcksum, 1);
1790 		rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1791 		rp = mfmblkencode(&hcksum, rp, NULL, 1);
1792 
1793 		crp = rp;
1794 		rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1795 		dp += FDSECLWORDS;
1796 		crp = mfmblkencode(&dcksum, crp, NULL, 1);
1797 		if (*(crp - 1) & 0x1)
1798 			*crp &= 0x7fffffff;	/* clock bit correction */
1799 		else if ((*crp & 0x40000000) == 0)
1800 			*crp |= 0x80000000;
1801 	}
1802 	*rp = 0xaaa80000;
1803 	if (*(rp - 1) & 0x1)
1804 		*rp &= 0x7fffffff;
1805 }
1806 
1807 u_long *
1808 fdfindsync(rp, ep)
1809 	u_long *rp, *ep;
1810 {
1811 	u_short *sp;
1812 
1813 	sp = (u_short *)rp;
1814 	while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1815 		sp++;
1816 	while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1817 		sp++;
1818 	if ((u_long *)sp < ep)
1819 		return((u_long *)sp);
1820 	return(NULL);
1821 }
1822 
1823 int
1824 amrawtocache(sc)
1825 	struct fd_softc *sc;
1826 {
1827 	u_long mfmnull[4];
1828 	u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1829 	int cnt, doagain;
1830 
1831 	doagain = 1;
1832 	srp = rp = fdc_dmap;
1833 	erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1834 	cnt = 0;
1835 again:
1836 	if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1837 #ifdef DIAGNOSTIC
1838 		printf("%s: corrupted track (%d) data.\n",
1839 		    sc->sc_dv.dv_xname, sc->cachetrk);
1840 #endif
1841 		return(-1);
1842 	}
1843 
1844 	/*
1845 	 * process sectors
1846 	 */
1847 	for (; cnt < sc->nsectors; cnt++) {
1848 		hcksum = dcksum = 0;
1849 		rp = mfmblkdecode(rp, &info, &hcksum, 1);
1850 		rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1851 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1852 		if (cktmp != hcksum) {
1853 #ifdef FDDEBUG
1854 			printf("  info 0x%x hchksum 0x%x trkhcksum 0x%x\n",
1855 			    info, hcksum, cktmp);
1856 #endif
1857 			goto again;
1858 		}
1859 		if (((info >> 16) & 0xff) != sc->cachetrk) {
1860 #ifdef DEBUG
1861 			printf("%s: incorrect track found: 0x%lx %d\n",
1862 			    sc->sc_dv.dv_xname, info, sc->cachetrk);
1863 #endif
1864 			goto again;
1865 		}
1866 #ifdef FDDEBUG
1867 		printf("  info 0x%x\n", info);
1868 #endif
1869 
1870 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1871 		dp = sc->cachep;
1872 		dp += FDSECLWORDS * ((info >> 8) & 0xff);
1873 		crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1874 		if (cktmp != dcksum) {
1875 #ifdef FDDEBUG
1876 			printf("  info 0x%x dchksum 0x%x trkdcksum 0x%x\n",
1877 			    info, dcksum, cktmp);
1878 #endif
1879 			goto again;
1880 		}
1881 
1882 		/*
1883 		 * if we are at gap then we can no longer be sure
1884 		 * of correct sync marks
1885 		 */
1886 		if ((info && 0xff) == 1)
1887 			doagain = 1;
1888 		else
1889 			doagain = 0;
1890 		srp = rp = fdfindsync(crp, erp);
1891 	}
1892 	return(0);
1893 }
1894 
1895 void
1896 mscachetoraw(sc)
1897 	struct fd_softc *sc;
1898 {
1899 	u_short *rp, *erp, crc;
1900 	u_char *cp, tb[5];
1901 	int sec, i;
1902 
1903 	rp = (u_short *)fdc_dmap;
1904 	erp = rp + sc->type->nwritew;
1905 	cp = sc->cachep;
1906 
1907 	/*
1908 	 * initial track filler  (828 * GAP1)
1909 	 */
1910 	for (i = 0; i < sc->type->gap; i++) {
1911 		*rp++ = FDMFMGAP1;
1912 		*rp++ = FDMFMGAP1;
1913 	}
1914 
1915 	for (sec = 0; sec < sc->nsectors; sec++) {
1916 
1917 		/*
1918 		 * leading sector gap
1919 		 * (12 * GAP2) + (3 * SYNC)
1920 		 */
1921 		for (i = 0; i < 12; i++)
1922 			*rp++ = FDMFMGAP2;
1923 		*rp++ = FDMFMSYNC;
1924 		*rp++ = FDMFMSYNC;
1925 		*rp++ = FDMFMSYNC;
1926 
1927 		/*
1928 		 * sector information
1929 		 * (ID) + track + side + sector + sector size + CRC16
1930 		 */
1931 		*rp++ = FDMFMID;
1932 		tb[0] = sc->cachetrk / FDNHEADS;
1933 		tb[1] = sc->cachetrk % FDNHEADS;
1934 		tb[2] = sec + 1;
1935 		i = sc->bytespersec;
1936 		tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1937 		rp = msblkencode(rp, tb, 4, &crc);
1938 		tb[0] = crc >> 8;
1939 		tb[1] = crc & 0xff;
1940 		tb[2] = 0x4e; /* GAP1 decoded */
1941 		rp = msblkencode(rp, tb, 3, 0);
1942 
1943 		/*
1944 		 * sector info/data gap
1945 		 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1946 		 */
1947 		for (i = 0; i < 21; i++)
1948 			*rp++ = FDMFMGAP1;
1949 		for (i = 0; i < 12; i++)
1950 			*rp++ = FDMFMGAP2;
1951 		*rp++ = FDMFMSYNC;
1952 		*rp++ = FDMFMSYNC;
1953 		*rp++ = FDMFMSYNC;
1954 
1955 		/*
1956 		 * sector data
1957 		 * (DATA) + ...data... + CRC16
1958 		 */
1959 		*rp++ = FDMFMDATA;
1960 		rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1961 		cp += sc->bytespersec;
1962 		tb[0] = crc >> 8;
1963 		tb[1] = crc & 0xff;
1964 		tb[2] = 0x4e; /* GAP3 decoded */
1965 		rp = msblkencode(rp, tb, 3, 0);
1966 
1967 		/*
1968 		 * trailing sector gap
1969 		 * (80 * GAP3)
1970 		 */
1971 		for (i = 0; i < 79; i++)
1972 			*rp++ = FDMFMGAP3;
1973 	}
1974 
1975 	/*
1976 	 * fill rest of track with GAP3
1977 	 */
1978 	while (rp != erp)
1979 		*rp++ = FDMFMGAP3;
1980 
1981 }
1982 
1983 int
1984 msrawtocache(sc)
1985 	struct fd_softc *sc;
1986 {
1987 	u_short *rp, *srp, *erp;
1988 	u_char tb[5], *cp;
1989 	int ct, sec, retry;
1990 
1991 	srp = rp = (u_short *)fdc_dmap;
1992 	erp = rp + sc->type->nreadw;
1993 	cp = sc->cachep;
1994 
1995 	for (ct = 0; ct < sc->nsectors; ct++) {
1996 		retry = 1;
1997 		do {
1998 			/*
1999 			 * skip leading gap to sync
2000 			 */
2001 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
2002 #ifdef DIAGNOSTIC
2003 				printf("%s: corrupted track (%d) data.\n",
2004 				sc->sc_dv.dv_xname, sc->cachetrk);
2005 #endif
2006 				return(-1);
2007 			}
2008 
2009 			/*
2010 			 * Grab sector info
2011 			 */
2012 			if (*rp++ != FDMFMID)
2013 				continue;
2014 			rp = msblkdecode(rp, tb, 4);
2015 #ifdef FDDEBUG
2016 			printf("sector id: sector %d, track %d, side %d,"
2017 			    "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
2018 #endif
2019 			if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
2020 			    tb[2] > sc->nsectors)
2021 				continue;
2022 
2023 			sec = tb[2];
2024 			sc->bytespersec = 128 << tb[3];
2025 			rp += 2; /* skip CRC-16 */
2026 
2027 			/*
2028 			 * skip gap and read in data
2029 			 */
2030 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
2031 				return(-1);
2032 			if (*rp++ != FDMFMDATA)
2033 				continue;
2034 			rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
2035 			    sc->bytespersec);
2036 			rp += 2; /* skip CRC-16 */
2037 
2038 			retry = 0;
2039 		} while (retry);
2040 	}
2041 	return(0);
2042 }
2043 
2044 /*
2045  * encode len longwords of `dp' data in amiga mfm block format (`rp')
2046  * this format specified that the odd bits are at current pos and even
2047  * bits at len + current pos
2048  */
2049 u_long *
2050 mfmblkencode(dp, rp, cp, len)
2051 	u_long *dp, *rp, *cp;
2052 	int len;
2053 {
2054 	u_long *sdp, *edp, d, dtmp, correct;
2055 
2056 	sdp = dp;
2057 	edp = dp + len;
2058 
2059 	if (*(rp - 1) & 0x1)
2060 		correct = 1;
2061 	else
2062 		correct = 0;
2063 	/*
2064 	 * do odd bits
2065 	 */
2066 	while (dp < edp) {
2067 		d = (*dp >> 1) & 0x55555555;	/* remove clock bits */
2068 		dtmp = d ^ 0x55555555;
2069 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2070 		/*
2071 		 * correct upper clock bit if needed
2072 		 */
2073 		if (correct)
2074 			d &= 0x7fffffff;
2075 		if (d & 0x1)
2076 			correct = 1;
2077 		else
2078 			correct = 0;
2079 		/*
2080 		 * do checksums and store in raw buffer
2081 		 */
2082 		if (cp)
2083 			*cp ^= d;
2084 		*rp++ = d;
2085 		dp++;
2086 	}
2087 	/*
2088 	 * do even bits
2089 	 */
2090 	dp = sdp;
2091 	while (dp < edp) {
2092 		d = *dp & 0x55555555;	/* remove clock bits */
2093 		dtmp = d ^ 0x55555555;
2094 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2095 		/*
2096 		 * correct upper clock bit if needed
2097 		 */
2098 		if (correct)
2099 			d &= 0x7fffffff;
2100 		if (d & 0x1)
2101 			correct = 1;
2102 		else
2103 			correct = 0;
2104 		/*
2105 		 * do checksums and store in raw buffer
2106 		 */
2107 		if (cp)
2108 			*cp ^= d;
2109 		*rp++ = d;
2110 		dp++;
2111 	}
2112 	if (cp)
2113 		*cp &= 0x55555555;
2114 	return(rp);
2115 }
2116 
2117 /*
2118  * decode len longwords of `dp' data in amiga mfm block format (`rp')
2119  * this format specified that the odd bits are at current pos and even
2120  * bits at len + current pos
2121  */
2122 u_long *
2123 mfmblkdecode(rp, dp, cp, len)
2124 	u_long *rp, *dp, *cp;
2125 	int len;
2126 {
2127 	u_long o, e;
2128 	int cnt;
2129 
2130 	cnt = len;
2131 	while (cnt--) {
2132 		o = *rp;
2133 		e = *(rp + len);
2134 		if (cp) {
2135 			*cp ^= o;
2136 			*cp ^= e;
2137 		}
2138 		o &= 0x55555555;
2139 		e &= 0x55555555;
2140 		*dp++ = (o << 1) | e;
2141 		rp++;
2142 	}
2143 	if (cp)
2144 		*cp &= 0x55555555;
2145 	return(rp + len);
2146 }
2147 
2148 /*
2149  * decode len words in standard MFM format to len bytes
2150  * of data.
2151  */
2152 u_short *
2153 msblkdecode(rp, cp, len)
2154 	u_short *rp;
2155 	u_char *cp;
2156 	int len;
2157 {
2158 	while (len--) {
2159 		*cp++ = msdecode[*rp & 0x7f] |
2160 		    (msdecode[(*rp >> 8) & 0x7f] << 4);
2161 		rp++;
2162 	}
2163 
2164 	return(rp);
2165 }
2166 
2167 /*
2168  * encode len bytes of data into len words in standard MFM format.
2169  * If a pointer is supplied for crc, calculate the CRC-16 of the data
2170  * as well.
2171  */
2172 u_short *
2173 msblkencode(rp, cp, len, crc)
2174 	u_short *rp;
2175 	u_char *cp;
2176 	int len;
2177 	u_short *crc;
2178 {
2179 	u_short td;
2180 	u_short mycrc;
2181 
2182 	/* preload crc for header (4 bytes)
2183 	 * or data (anything else)
2184 	 */
2185 	mycrc = (len == 4) ? 0xb230 : 0xe295;
2186 
2187 	while (len--) {
2188 		td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2189 
2190 		/* Check for zeros in top bit of encode and bottom
2191 		 * bit of previous encode.  if so, slap a one in betweem
2192 		 * them.
2193 		 */
2194 		if ((td & 0x140) == 0)
2195 			td |= 0x80;
2196 		if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2197 			td |= 0x8000;
2198 
2199 		*rp++ = td;
2200 
2201 		/*
2202 		 * calc crc if requested
2203 		 */
2204 		if (crc)
2205 			mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2206 
2207 		cp++;
2208 	}
2209 
2210 	if (crc)
2211 		*crc = mycrc;
2212 
2213 	return(rp);
2214 }
2215 
2216 int
2217 fddump(dev, blkno, va, size)
2218 	dev_t	dev;
2219 	daddr_t	blkno;
2220 	caddr_t	va;
2221 	size_t	size;
2222 {
2223 	return (EINVAL);
2224 }
2225