xref: /netbsd-src/sys/arch/amiga/dev/fd.c (revision f14316bcbc544b96a93e884bc5c2b15fd60e22ae)
1 /*	$NetBSD: fd.c,v 1.92 2014/08/08 21:13:52 joerg 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 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.92 2014/08/08 21:13:52 joerg Exp $");
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/callout.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/buf.h>
44 #include <sys/bufq.h>
45 #include <sys/device.h>
46 #include <sys/ioctl.h>
47 #include <sys/fcntl.h>
48 #include <sys/disklabel.h>
49 #include <sys/disk.h>
50 #include <sys/dkbad.h>
51 #include <sys/proc.h>
52 #include <sys/conf.h>
53 
54 #include <machine/cpu.h>
55 #include <amiga/amiga/device.h>
56 #include <amiga/amiga/custom.h>
57 #include <amiga/amiga/cia.h>
58 #include <amiga/amiga/cc.h>
59 
60 #include "locators.h"
61 
62 enum fdc_bits { FDB_CHANGED = 2, FDB_PROTECT, FDB_CYLZERO, FDB_READY };
63 /*
64  * partitions in fd represent different format floppies
65  * partition a is 0 etc..
66  */
67 enum fd_parttypes {
68 	FDAMIGAPART = 0,
69 	FDMSDOSPART,
70 	FDMAXPARTS
71 };
72 
73 #define FDBBSIZE	(8192)
74 #define FDSBSIZE	(8192)
75 
76 #define FDUNIT(dev)	DISKUNIT(dev)
77 #define FDPART(dev)	DISKPART(dev)
78 #define FDMAKEDEV(m, u, p)	MAKEDISKDEV((m), (u), (p))
79 
80 /* that's nice, but we don't want to always use this as an amiga drive
81 bunghole :-) */
82 #define FDNHEADS	(2)	/* amiga drives always have 2 heads */
83 #define FDSECSIZE	(512)	/* amiga drives always have 512 byte sectors */
84 #define FDSECLWORDS	(128)
85 
86 #define FDSETTLEDELAY	(18000)	/* usec delay after seeking after switch dir */
87 #define FDSTEPDELAY	(3500)	/* usec delay after steping */
88 #define FDPRESIDEDELAY	(1000)	/* usec delay before writing can occur */
89 #define FDWRITEDELAY	(1300)	/* usec delay after write */
90 
91 #define FDSTEPOUT	(1)	/* decrease track step */
92 #define FDSTEPIN	(0)	/* increase track step */
93 
94 #define FDCUNITMASK	(0x78)	/* mask for all units (bits 6-3) */
95 
96 #define FDRETRIES	(2)	/* default number of retries */
97 #define FDMAXUNITS	(4)	/* maximum number of supported units */
98 
99 #define DISKLEN_READ	(0)	/* fake mask for reading */
100 #define DISKLEN_WRITE	(1 << 14)	/* bit for writing */
101 #define DISKLEN_DMAEN	(1 << 15)	/* DMA go */
102 #define DMABUFSZ ((DISKLEN_WRITE - 1) * 2)	/* largest DMA possible */
103 
104 #define FDMFMSYNC	(0x4489)
105 #define FDMFMID		(0x5554)
106 #define FDMFMDATA	(0x5545)
107 #define FDMFMGAP1	(0x9254)
108 #define FDMFMGAP2	(0xAAAA)
109 #define FDMFMGAP3	(0x9254)
110 #define CRC16POLY	(0x1021) /* (x^16) + x^12 + x^5 + x^0 */
111 
112 /*
113  * Msdos-type MFM encode/decode
114  */
115 static u_char msdecode[128];
116 static u_char msencode[16] =
117 {
118     0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
119     0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
120 };
121 static u_short mscrctab[256];
122 
123 /*
124   5554    aaaa    aaaa    aaa5    2aa4    4452    aa51
125           00      00      03      02      ac      0d
126 */
127 
128 /*
129  * floppy device type
130  */
131 struct fdtype {
132 	u_int driveid;		/* drive identification (from drive) */
133 	u_int ncylinders;	/* number of cylinders on drive */
134 	u_int amiga_nsectors;	/* number of sectors per amiga track */
135 	u_int msdos_nsectors;	/* number of sectors per msdos track */
136 	u_int nreadw;		/* number of words (short) read per track */
137 	u_int nwritew;		/* number of words (short) written per track */
138 	u_int gap;		/* track gap size in long words */
139 	const u_int precomp[2];	/* 1st and 2nd precomp values */
140 	const char *desc;	/* description of drive type (useq) */
141 };
142 
143 /*
144  * floppy disk device data
145  */
146 struct fd_softc {
147 	device_t sc_dev;	/* generic device info; must come first */
148 	struct disk dkdev;	/* generic disk info */
149 	struct bufq_state *bufq;/* queue pending I/O operations */
150 	struct buf curbuf;	/* state of current I/O operation */
151 	struct callout calibrate_ch;
152 	struct callout motor_ch;
153 	struct fdtype *type;
154 	void *cachep;		/* cached track data (write through) */
155 	int cachetrk;		/* cahced track -1 for none */
156 	int hwunit;		/* unit for amiga controlling hw */
157 	int unitmask;		/* mask for cia select deslect */
158 	int pstepdir;		/* previous step direction */
159 	int curcyl;		/* current curcyl head positioned on */
160 	int flags;		/* misc flags */
161 	int wlabel;
162 	int stepdelay;		/* useq to delay after seek user setable */
163 	int nsectors;		/* number of sectors per track */
164 	int openpart;		/* which partition [ab] == [12] is open */
165 	short retries;		/* number of times to retry failed io */
166 	short retried;		/* number of times current io retried */
167 	int bytespersec;	/* number of bytes per sector */
168 };
169 
170 /* fd_softc->flags */
171 #define FDF_MOTORON	(0x01)	/* motor is running */
172 #define FDF_MOTOROFF	(0x02)	/* motor is waiting to be turned off */
173 #define FDF_WMOTOROFF	(0x04)	/* unit wants a wakeup after off */
174 #define FDF_DIRTY	(0x08)	/* track cache needs write */
175 #define FDF_WRITEWAIT	(0x10)	/* need to head select delay on next setpos */
176 #define FDF_HAVELABEL	(0x20)	/* label is valid */
177 #define FDF_JUSTFLUSH	(0x40)	/* don't bother caching track. */
178 #define FDF_NOTRACK0	(0x80)	/* was not able to recalibrate drive */
179 
180 int fdc_wantwakeup;
181 int fdc_side;
182 void  *fdc_dmap;
183 struct fd_softc *fdc_indma;
184 int fdc_dmalen;
185 int fdc_dmawrite;
186 
187 struct fdcargs {
188 	struct fdtype *type;
189 	int unit;
190 };
191 
192 int	fdcmatch(device_t, cfdata_t, void *);
193 void	fdcattach(device_t, device_t, void *);
194 int	fdcprint(void *, const char *);
195 int	fdmatch(device_t, cfdata_t, void *);
196 void	fdattach(device_t, device_t, void *);
197 
198 void	fdintr(int);
199 void	fdidxintr(void);
200 int	fdloaddisk(struct fd_softc *);
201 void	fdgetdefaultlabel(struct fd_softc *, struct disklabel *, int);
202 int	fdgetdisklabel(struct fd_softc *, dev_t);
203 int	fdsetdisklabel(struct fd_softc *, struct disklabel *);
204 int	fdputdisklabel(struct fd_softc *, dev_t);
205 struct	fdtype * fdcgetfdtype(int);
206 void	fdmotoroff(void *);
207 void	fdsetpos(struct fd_softc *, int, int);
208 void	fdselunit(struct fd_softc *);
209 void	fdstart(struct fd_softc *);
210 void	fdcont(struct fd_softc *);
211 void	fddmastart(struct fd_softc *, int);
212 void	fdcalibrate(void *);
213 void	fddmadone(struct fd_softc *, int);
214 void	fddone(struct fd_softc *);
215 void	fdfindwork(int);
216 void	fdminphys(struct buf *);
217 void	fdcachetoraw(struct fd_softc *);
218 void	amcachetoraw(struct fd_softc *);
219 int	amrawtocache(struct fd_softc *);
220 u_long	*fdfindsync(u_long *, u_long *);
221 int	fdrawtocache(struct fd_softc *);
222 void	mscachetoraw(struct fd_softc *);
223 int	msrawtocache(struct fd_softc *);
224 u_long	*mfmblkencode(u_long *, u_long *, u_long *, int);
225 u_long	*mfmblkdecode(u_long *, u_long *, u_long *, int);
226 u_short	*msblkdecode(u_short *, u_char *, int);
227 u_short	*msblkencode(u_short *, u_char *, int, u_short *);
228 
229 /*
230  * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts
231  * write size is nsectors * mfm secsize + gap bytes + 3 shorts
232  * the extra shorts are to deal with a DMA hw bug in the controller
233  * they are probably too much (I belive the bug is 1 short on write and
234  * 3 bits on read) but there is no need to be cheap here.
235  */
236 #define MAXTRKSZ (22 * FDSECSIZE)
237 struct fdtype fdtype[] = {
238 	{ 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" },
239 	{ 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" },
240 	{ 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" }
241 };
242 int nfdtype = __arraycount(fdtype);
243 
244 CFATTACH_DECL_NEW(fd, sizeof(struct fd_softc),
245     fdmatch, fdattach, NULL, NULL);
246 
247 extern struct cfdriver fd_cd;
248 
249 dev_type_open(fdopen);
250 dev_type_close(fdclose);
251 dev_type_read(fdread);
252 dev_type_write(fdwrite);
253 dev_type_ioctl(fdioctl);
254 dev_type_strategy(fdstrategy);
255 
256 const struct bdevsw fd_bdevsw = {
257 	.d_open = fdopen,
258 	.d_close = fdclose,
259 	.d_strategy = fdstrategy,
260 	.d_ioctl = fdioctl,
261 	.d_dump = nodump,
262 	.d_psize = nosize,
263 	.d_discard = nodiscard,
264 	.d_flag = D_DISK
265 };
266 
267 const struct cdevsw fd_cdevsw = {
268 	.d_open = fdopen,
269 	.d_close = fdclose,
270 	.d_read = fdread,
271 	.d_write = fdwrite,
272 	.d_ioctl = fdioctl,
273 	.d_stop = nostop,
274 	.d_tty = notty,
275 	.d_poll = nopoll,
276 	.d_mmap = nommap,
277 	.d_kqfilter = nokqfilter,
278 	.d_discard = nodiscard,
279 	.d_flag = D_DISK
280 };
281 
282 struct dkdriver fddkdriver = { fdstrategy };
283 
284 CFATTACH_DECL_NEW(fdc, 0,
285     fdcmatch, fdcattach, NULL, NULL);
286 
287 /*
288  * all hw access through macros, this helps to hide the active low
289  * properties
290  */
291 
292 #define FDUNITMASK(unit)	(1 << (3 + (unit)))
293 
294 /*
295  * select units using mask
296  */
297 #define FDSELECT(um)	do { ciab.prb &= ~(um); } while (0)
298 
299 /*
300  * deselect units using mask
301  */
302 #define FDDESELECT(um)	do { ciab.prb |= (um); delay(1); } while (0)
303 
304 /*
305  * test hw condition bits
306  */
307 #define FDTESTC(bit)	((ciaa.pra & (1 << (bit))) == 0)
308 
309 /*
310  * set motor for select units, true motor on else off
311  */
312 #define FDSETMOTOR(on)	do { \
313 	if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
314 	} while (0)
315 
316 /*
317  * set head for select units
318  */
319 #define FDSETHEAD(head)	do { \
320 	if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
321 	delay(1); } while (0)
322 
323 /*
324  * select direction, true towards spindle else outwards
325  */
326 #define FDSETDIR(in)	do { \
327 	if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
328 	delay(1); } while (0)
329 
330 /*
331  * step the selected units
332  */
333 #define FDSTEP	do { \
334     ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
335     } while (0)
336 
337 #define FDDMASTART(len, towrite)	do { \
338     int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
339     custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
340 
341 #define FDDMASTOP	do { custom.dsklen = 0; } while (0)
342 
343 
344 int
345 fdcmatch(device_t parent, cfdata_t cf, void *aux)
346 {
347 	static int fdc_matched = 0;
348 
349 	/* Allow only once instance. */
350 	if (matchname("fdc", aux) == 0 || fdc_matched)
351 		return(0);
352 	if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
353 		printf("fdc: unable to allocate DMA buffer\n");
354 		return(0);
355 	}
356 
357 	fdc_matched = 1;
358 	return(1);
359 }
360 
361 void
362 fdcattach(device_t parent, device_t self, void *aux)
363 {
364 	struct fdcargs args;
365 
366 	printf(": dmabuf pa 0x%x", (unsigned)kvtop(fdc_dmap));
367 	printf(": dmabuf ka %p\n", fdc_dmap);
368 	args.unit = 0;
369 	args.type = fdcgetfdtype(args.unit);
370 
371 	fdc_side = -1;
372 	config_found(self, &args, fdcprint);
373 	for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
374 		if ((args.type = fdcgetfdtype(args.unit)) == NULL)
375 			continue;
376 		config_found(self, &args, fdcprint);
377 	}
378 }
379 
380 int
381 fdcprint(void *aux, const char *pnp)
382 {
383 	struct fdcargs *fcp;
384 
385 	fcp = aux;
386 	if (pnp)
387 		aprint_normal("fd%d at %s unit %d:", fcp->unit, pnp,
388 			fcp->type->driveid);
389 	return(UNCONF);
390 }
391 
392 /*ARGSUSED*/
393 int
394 fdmatch(device_t parent, cfdata_t cf, void *aux)
395 {
396 	struct fdcargs *fdap;
397 
398 	fdap = aux;
399 	if (cf->cf_loc[FDCCF_UNIT] == fdap->unit ||
400 	    cf->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT)
401 		return(1);
402 
403 	return(0);
404 }
405 
406 void
407 fdattach(device_t parent, device_t self, void *aux)
408 {
409 	struct fdcargs *ap;
410 	struct fd_softc *sc;
411 	int i;
412 
413 	ap = aux;
414 	sc = device_private(self);
415 	sc->sc_dev = self;
416 
417 	bufq_alloc(&sc->bufq, "disksort", BUFQ_SORT_CYLINDER);
418 	callout_init(&sc->calibrate_ch, 0);
419 	callout_init(&sc->motor_ch, 0);
420 
421 	sc->curcyl = sc->cachetrk = -1;
422 	sc->openpart = -1;
423 	sc->type = ap->type;
424 	sc->hwunit = ap->unit;
425 	sc->unitmask = 1 << (3 + ap->unit);
426 	sc->retries = FDRETRIES;
427 	sc->stepdelay = FDSTEPDELAY;
428 	sc->bytespersec = 512;
429 	printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
430 	    sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
431 	    sc->type->amiga_nsectors, sc->type->msdos_nsectors);
432 
433 	/*
434 	 * Initialize and attach the disk structure.
435 	 */
436 	disk_init(&sc->dkdev, device_xname(sc->sc_dev), &fddkdriver);
437 	disk_attach(&sc->dkdev);
438 
439 	/*
440 	 * calibrate the drive
441 	 */
442 	fdsetpos(sc, 0, 0);
443 	fdsetpos(sc, sc->type->ncylinders, 0);
444 	fdsetpos(sc, 0, 0);
445 	fdmotoroff(sc);
446 
447 	/*
448 	 * precalc msdos MFM and CRC
449 	 */
450 	for (i = 0; i < 128; i++)
451 		msdecode[i] = 0xff;
452 	for (i = 0; i < 16; i++)
453 		msdecode[msencode[i]] = i;
454 	for (i = 0; i < 256; i++) {
455 		mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
456 		    (0x1021 * (i >> 4));
457 	}
458 
459 	/*
460 	 * enable disk related interrupts
461 	 */
462 	custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
463 	custom.intena = INTF_SETCLR | INTF_DSKBLK;
464 	ciab.icr = CIA_ICR_FLG;
465 }
466 
467 /*ARGSUSED*/
468 int
469 fdopen(dev_t dev, int flags, int devtype, struct lwp *l)
470 {
471 	struct fd_softc *sc;
472 	int wasopen, fwork, error, s;
473 
474 	error = 0;
475 
476 	if (FDPART(dev) >= FDMAXPARTS)
477 		return(ENXIO);
478 
479 	if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
480 		return(ENXIO);
481 	if (sc->flags & FDF_NOTRACK0)
482 		return(ENXIO);
483 	if (sc->cachep == NULL)
484 		sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
485 
486 	s = splbio();
487 	/*
488 	 * if we are sleeping in fdclose(); waiting for a chance to
489 	 * shut the motor off, do a sleep here also.
490 	 */
491 	while (sc->flags & FDF_WMOTOROFF)
492 		tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
493 
494 	fwork = 0;
495 	/*
496 	 * if not open let user open request type, otherwise
497 	 * ensure they are trying to open same type.
498 	 */
499 	if (sc->openpart == FDPART(dev))
500 		wasopen = 1;
501 	else if (sc->openpart == -1) {
502 		sc->openpart = FDPART(dev);
503 		wasopen = 0;
504 	} else {
505 		wasopen = 1;
506 		error = EPERM;
507 		goto done;
508 	}
509 
510 	/*
511 	 * wait for current io to complete if any
512 	 */
513 	if (fdc_indma) {
514 		fwork = 1;
515 		fdc_wantwakeup++;
516 		tsleep(fdopen, PRIBIO, "fdopen", 0);
517 	}
518 	if ((error = fdloaddisk(sc)) != 0)
519 		goto done;
520 	if ((error = fdgetdisklabel(sc, dev)) != 0)
521 		goto done;
522 #ifdef FDDEBUG
523 	printf("  open successful\n");
524 #endif
525 done:
526 	/*
527 	 * if we requested that fddone()->fdfindwork() wake us, allow it to
528 	 * complete its job now
529 	 */
530 	if (fwork)
531 		fdfindwork(FDUNIT(dev));
532 	splx(s);
533 
534 	/*
535 	 * if we were not open and we marked us so reverse that.
536 	 */
537 	if (error && wasopen == 0)
538 		sc->openpart = -1;
539 	return(error);
540 }
541 
542 /*ARGSUSED*/
543 int
544 fdclose(dev_t dev, int flags, int devtype, struct lwp *l)
545 {
546 	struct fd_softc *sc;
547 	int s;
548 
549 #ifdef FDDEBUG
550 	printf("fdclose()\n");
551 #endif
552 	sc = getsoftc(fd_cd, FDUNIT(dev));
553 	s = splbio();
554 	if (sc->flags & FDF_MOTORON) {
555 		sc->flags |= FDF_WMOTOROFF;
556 		tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
557 		sc->flags &= ~FDF_WMOTOROFF;
558 		wakeup(fdmotoroff);
559 	}
560 	sc->openpart = -1;
561 	splx(s);
562 	return(0);
563 }
564 
565 int
566 fdioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
567 {
568 	struct fd_softc *sc;
569 	int error, wlab;
570 
571 	sc = getsoftc(fd_cd, FDUNIT(dev));
572 
573 	if ((sc->flags & FDF_HAVELABEL) == 0)
574 		return(EBADF);
575 
576 	switch (cmd) {
577 	case DIOCSBAD:
578 		return(EINVAL);
579 	case DIOCSRETRIES:
580 		if (*(int *)addr < 0)
581 			return(EINVAL);
582 		sc->retries = *(int *)addr;
583 		return(0);
584 	case DIOCSSTEP:
585 		if (*(int *)addr < FDSTEPDELAY)
586 			return(EINVAL);
587 		sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
588 		return(0);
589 	case DIOCGDINFO:
590 		*(struct disklabel *)addr = *(sc->dkdev.dk_label);
591 		return(0);
592 	case DIOCGPART:
593 		((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
594 		((struct partinfo *)addr)->part =
595 		    &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
596 		return(0);
597 	case DIOCSDINFO:
598 		if ((flag & FWRITE) == 0)
599 			return(EBADF);
600 		return(fdsetdisklabel(sc, (struct disklabel *)addr));
601 	case DIOCWDINFO:
602 		if ((flag & FWRITE) == 0)
603 			return(EBADF);
604 		if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
605 			return(error);
606 		wlab = sc->wlabel;
607 		sc->wlabel = 1;
608 		error = fdputdisklabel(sc, dev);
609 		sc->wlabel = wlab;
610 		return(error);
611 	case DIOCWLABEL:
612 		if ((flag & FWRITE) == 0)
613 			return(EBADF);
614 		sc->wlabel = *(int *)addr;
615 		return(0);
616 	case DIOCGDEFLABEL:
617 		fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
618 		return(0);
619 	default:
620 		return(ENOTTY);
621 	}
622 }
623 
624 int
625 fdread(dev_t dev, struct uio *uio, int flags)
626 {
627 	return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
628 }
629 
630 int
631 fdwrite(dev_t dev, struct uio *uio, int flags)
632 {
633 	return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
634 }
635 
636 
637 void
638 fdintr(int flag)
639 {
640 	int s;
641 
642 	s = splbio();
643 	if (fdc_indma)
644 		fddmadone(fdc_indma, 0);
645 	splx(s);
646 }
647 
648 void
649 fdidxintr(void)
650 {
651 	if (fdc_indma && fdc_dmalen) {
652 		/*
653 		 * turn off intr and start actual dma
654 		 */
655 		ciab.icr = CIA_ICR_FLG;
656 		FDDMASTART(fdc_dmalen, fdc_dmawrite);
657 		fdc_dmalen = 0;
658 	}
659 }
660 
661 void
662 fdstrategy(struct buf *bp)
663 {
664 	struct fd_softc *sc;
665 	int unit, s;
666 
667 	unit = FDUNIT(bp->b_dev);
668 	sc = getsoftc(fd_cd, unit);
669 
670 #ifdef FDDEBUG
671 	printf("fdstrategy: %p\n", bp);
672 #endif
673 	/*
674 	 * check for valid partition and bounds
675 	 */
676 	if ((sc->flags & FDF_HAVELABEL) == 0) {
677 		bp->b_error = EIO;
678 		goto done;
679 	}
680 	if (bounds_check_with_label(&sc->dkdev, bp, sc->wlabel) <= 0)
681 		goto done;
682 
683 	/*
684 	 * trans count of zero or bounds check indicates io is done
685 	 * we are done.
686 	 */
687 	if (bp->b_bcount == 0)
688 		goto done;
689 
690 	bp->b_rawblkno = bp->b_blkno;
691 
692 	/*
693 	 * queue the buf and kick the low level code
694 	 */
695 	s = splbio();
696 	bufq_put(sc->bufq, bp);
697 	fdstart(sc);
698 	splx(s);
699 	return;
700 done:
701 	bp->b_resid = bp->b_bcount;
702 	biodone(bp);
703 }
704 
705 /*
706  * make sure disk is loaded and label is up-to-date.
707  */
708 int
709 fdloaddisk(struct fd_softc *sc)
710 {
711 	/*
712 	 * if diskchange is low step drive to 0 then up one then to zero.
713 	 */
714 	fdselunit(sc);			/* make sure the unit is selected */
715 	if (FDTESTC(FDB_CHANGED)) {
716 		fdsetpos(sc, 0, 0);
717 		sc->cachetrk = -1;		/* invalidate the cache */
718 		sc->flags &= ~FDF_HAVELABEL;
719 		fdsetpos(sc, FDNHEADS, 0);
720 		fdsetpos(sc, 0, 0);
721 		if (FDTESTC(FDB_CHANGED)) {
722 			fdmotoroff(sc);
723 			FDDESELECT(sc->unitmask);
724 			return(ENXIO);
725 		}
726 	}
727 	FDDESELECT(sc->unitmask);
728 	fdmotoroff(sc);
729 	sc->type = fdcgetfdtype(sc->hwunit);
730 	if (sc->type == NULL)
731 		return(ENXIO);
732 	if (sc->openpart == FDMSDOSPART)
733 		sc->nsectors = sc->type->msdos_nsectors;
734 	else
735 		sc->nsectors = sc->type->amiga_nsectors;
736 	return(0);
737 }
738 
739 void
740 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part)
741 /* (variable part) XXX ick */
742 {
743 
744 	memset(lp, 0, sizeof(struct disklabel));
745 	lp->d_secsize = FDSECSIZE;
746 	lp->d_ntracks = FDNHEADS;
747 	lp->d_ncylinders = sc->type->ncylinders;
748 	lp->d_nsectors = sc->nsectors;
749 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
750 	lp->d_type = DTYPE_FLOPPY;
751 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
752 	lp->d_rpm = 300; 		/* good guess I suppose. */
753 	lp->d_interleave = 1;		/* should change when adding msdos */
754 	sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
755 	lp->d_bbsize = 0;
756 	lp->d_sbsize = 0;
757 	lp->d_partitions[part].p_size = lp->d_secperunit;
758 	lp->d_partitions[part].p_fstype = FS_UNUSED;
759 	lp->d_partitions[part].p_fsize = 1024;
760 	lp->d_partitions[part].p_frag = 8;
761 	lp->d_partitions[part].p_cpg = 2;	/* adosfs: reserved blocks */
762 	lp->d_npartitions = part + 1;
763 	lp->d_magic = lp->d_magic2 = DISKMAGIC;
764 	lp->d_checksum = dkcksum(lp);
765 }
766 
767 /*
768  * read disk label, if present otherwise create one
769  * return a new label if raw part and none found, otherwise err.
770  */
771 int
772 fdgetdisklabel(struct fd_softc *sc, dev_t dev)
773 {
774 	struct disklabel *lp, *dlp;
775 	struct cpu_disklabel *clp;
776 	struct buf *bp;
777 	int error, part;
778 
779 	if (sc->flags & FDF_HAVELABEL &&
780 	    sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
781 		return(0);
782 #ifdef FDDEBUG
783 	printf("fdgetdisklabel()\n");
784 #endif
785 	part = FDPART(dev);
786 	lp = sc->dkdev.dk_label;
787 	clp =  sc->dkdev.dk_cpulabel;
788 	memset(lp, 0, sizeof(struct disklabel));
789 	memset(clp, 0, sizeof(struct cpu_disklabel));
790 
791 	lp->d_secsize = FDSECSIZE;
792 	lp->d_ntracks = FDNHEADS;
793 	lp->d_ncylinders = sc->type->ncylinders;
794 	lp->d_nsectors = sc->nsectors;
795 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
796 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
797 	lp->d_npartitions = part + 1;
798 	lp->d_partitions[part].p_size = lp->d_secperunit;
799 	lp->d_partitions[part].p_fstype = FS_UNUSED;
800 	lp->d_partitions[part].p_fsize = 1024;
801 	lp->d_partitions[part].p_frag = 8;
802 	lp->d_partitions[part].p_cpg = 2;	/* for adosfs: reserved blks */
803 
804 	sc->flags |= FDF_HAVELABEL;
805 
806 	bp = (void *)geteblk((int)lp->d_secsize);
807 	bp->b_dev = dev;
808 	bp->b_blkno = 0;
809 	bp->b_cylinder = 0;
810 	bp->b_bcount = FDSECSIZE;
811 	bp->b_flags |= B_READ;
812 	fdstrategy(bp);
813 	if ((error = biowait(bp)) != 0)
814 		goto nolabel;
815 	dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
816 	if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
817 	    dkcksum(dlp)) {
818 		error = EINVAL;
819 		goto nolabel;
820 	}
821 	memcpy(lp, dlp, sizeof(struct disklabel));
822 	if (lp->d_trkseek > FDSTEPDELAY)
823 		sc->stepdelay = lp->d_trkseek;
824 	brelse(bp, 0);
825 	return(0);
826 nolabel:
827 	fdgetdefaultlabel(sc, lp, part);
828 	brelse(bp, 0);
829 	return(0);
830 }
831 
832 /*
833  * set the incore copy of this units disklabel
834  */
835 int
836 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp)
837 {
838 	struct disklabel *clp;
839 	struct partition *pp;
840 
841 	/*
842 	 * must have at least opened raw unit to fetch the
843 	 * raw_part stuff.
844 	 */
845 	if ((sc->flags & FDF_HAVELABEL) == 0)
846 		return(EINVAL);
847 	clp = sc->dkdev.dk_label;
848 	/*
849 	 * make sure things check out and we only have one valid
850 	 * partition
851 	 */
852 #ifdef FDDEBUG
853 	printf("fdsetdisklabel\n");
854 #endif
855 	if (lp->d_secsize != FDSECSIZE ||
856 	    lp->d_nsectors != clp->d_nsectors ||
857 	    lp->d_ntracks != FDNHEADS ||
858 	    lp->d_ncylinders != clp->d_ncylinders ||
859 	    lp->d_secpercyl != clp->d_secpercyl ||
860 	    lp->d_secperunit != clp->d_secperunit ||
861 	    lp->d_magic != DISKMAGIC ||
862 	    lp->d_magic2 != DISKMAGIC ||
863 	    lp->d_npartitions == 0 ||
864 	    lp->d_npartitions > FDMAXPARTS ||
865 	    (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
866 	    dkcksum(lp))
867 		return(EINVAL);
868 	/*
869 	 * if any partitions are present make sure they
870 	 * represent the currently open type
871 	 */
872 	if ((pp = &lp->d_partitions[0])->p_size) {
873 		if ((pp = &lp->d_partitions[1])->p_size == 0)
874 			goto done;
875 		else if (sc->openpart != 1)
876 			return(EINVAL);
877 	} else if (sc->openpart != 0)
878 		return(EINVAL);
879 	/*
880 	 * make sure selected partition is within bounds
881 	 * XXX on the second check, its to handle a bug in
882 	 * XXX the cluster routines as they require mutliples
883 	 * XXX of PAGE_SIZE currently
884 	 */
885 	if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
886 	    (pp->p_frag * pp->p_fsize % PAGE_SIZE))
887 		return(EINVAL);
888 done:
889 	memcpy(clp, lp, sizeof(struct disklabel));
890 	return(0);
891 }
892 
893 /*
894  * write out the incore copy of this units disklabel
895  */
896 int
897 fdputdisklabel(struct fd_softc *sc, dev_t dev)
898 {
899 	struct disklabel *lp, *dlp;
900 	struct buf *bp;
901 	int error;
902 
903 	if ((sc->flags & FDF_HAVELABEL) == 0)
904 		return(EBADF);
905 #ifdef FDDEBUG
906 	printf("fdputdisklabel\n");
907 #endif
908 	/*
909 	 * get buf and read in sector 0
910 	 */
911 	lp = sc->dkdev.dk_label;
912 	bp = geteblk((int)lp->d_secsize);
913 	bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
914 	bp->b_blkno = 0;
915 	bp->b_cylinder = 0;
916 	bp->b_bcount = FDSECSIZE;
917 	bp->b_flags |= B_READ;
918 	fdstrategy(bp);
919 	if ((error = biowait(bp)) != 0)
920 		goto done;
921 	/*
922 	 * copy disklabel to buf and write it out synchronous
923 	 */
924 	dlp = (struct disklabel *)((char*)bp->b_data + LABELOFFSET);
925 	memcpy(dlp, lp, sizeof(struct disklabel));
926 	bp->b_blkno = 0;
927 	bp->b_cylinder = 0;
928 	bp->b_flags &= ~(B_READ);
929 	bp->b_oflags &= ~(BO_DONE);
930 	bp->b_flags |= B_WRITE;
931 	fdstrategy(bp);
932 	error = biowait(bp);
933 done:
934 	brelse(bp, 0);
935 	return(error);
936 }
937 
938 /*
939  * figure out drive type or NULL if none.
940  */
941 struct fdtype *
942 fdcgetfdtype(int unit)
943 {
944 	struct fdtype *ftp;
945 	u_long id, idb;
946 	int cnt, umask;
947 
948 	id = 0;
949 	umask = 1 << (3 + unit);
950 
951 	FDDESELECT(FDCUNITMASK);
952 
953 	FDSETMOTOR(1);
954 	delay(1);
955 	FDSELECT(umask);
956 	delay(1);
957 	FDDESELECT(umask);
958 
959 	FDSETMOTOR(0);
960 	delay(1);
961 	FDSELECT(umask);
962 	delay(1);
963 	FDDESELECT(umask);
964 
965 	for (idb = 0x80000000; idb; idb >>= 1) {
966 		FDSELECT(umask);
967 		delay(1);
968 		if (FDTESTC(FDB_READY) == 0)
969 			id |= idb;
970 		FDDESELECT(umask);
971 		delay(1);
972 	}
973 #ifdef FDDEBUG
974 	printf("fdcgettype unit %d id 0x%lx\n", unit, id);
975 #endif
976 
977 	for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
978 		if (ftp->driveid == id)
979 			return(ftp);
980 	/*
981 	 * 3.5dd's at unit 0 do not always return id.
982 	 */
983 	if (unit == 0)
984 		return(fdtype);
985 	return(NULL);
986 }
987 
988 /*
989  * turn motor off if possible otherwise mark as needed and will be done
990  * later.
991  */
992 void
993 fdmotoroff(void *arg)
994 {
995 	struct fd_softc *sc;
996 	int s;
997 
998 	sc = arg;
999 	s = splbio();
1000 
1001 #ifdef FDDEBUG
1002 	printf("fdmotoroff: unit %d\n", sc->hwunit);
1003 #endif
1004 	if ((sc->flags & FDF_MOTORON) == 0)
1005 		goto done;
1006 	/*
1007 	 * if we have a timeout on a DMA operation let fddmadone()
1008 	 * deal with it.
1009 	 */
1010 	if (fdc_indma == sc) {
1011 		fddmadone(sc, 1);
1012 		goto done;
1013 	}
1014 #ifdef FDDEBUG
1015 	printf(" motor was on, turning off\n");
1016 #endif
1017 
1018 	/*
1019 	 * flush cache if needed
1020 	 */
1021 	if (sc->flags & FDF_DIRTY) {
1022 		sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1023 #ifdef FDDEBUG
1024 		printf("  flushing dirty buffer first\n");
1025 #endif
1026 		/*
1027 		 * if DMA'ing done for now, fddone() will call us again
1028 		 */
1029 		if (fdc_indma)
1030 			goto done;
1031 		fddmastart(sc, sc->cachetrk);
1032 		goto done;
1033 	}
1034 
1035 	/*
1036 	 * if controller is busy just schedule us to be called back
1037 	 */
1038 	if (fdc_indma) {
1039 		/*
1040 		 * someone else has the controller now
1041 		 * just set flag and let fddone() call us again.
1042 		 */
1043 		sc->flags |= FDF_MOTOROFF;
1044 		goto done;
1045 	}
1046 
1047 #ifdef FDDEBUG
1048 	printf("  hw turning unit off\n");
1049 #endif
1050 
1051 	sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1052 	FDDESELECT(FDCUNITMASK);
1053 	FDSETMOTOR(0);
1054 	delay(1);
1055 	FDSELECT(sc->unitmask);
1056 	delay(4);
1057 	FDDESELECT(sc->unitmask);
1058 	delay(1);
1059 	if (sc->flags & FDF_WMOTOROFF)
1060 		wakeup(fdmotoroff);
1061 done:
1062 	splx(s);
1063 }
1064 
1065 /*
1066  * select drive seek to track exit with motor on.
1067  * fdsetpos(x, 0, 0) does calibrates the drive.
1068  */
1069 void
1070 fdsetpos(struct fd_softc *sc, int trk, int towrite)
1071 {
1072 	int nstep, sdir, ondly, ncyl, nside;
1073 
1074 	FDDESELECT(FDCUNITMASK);
1075 	FDSETMOTOR(1);
1076 	delay(1);
1077 	FDSELECT(sc->unitmask);
1078 	delay(1);
1079 	if ((sc->flags & FDF_MOTORON) == 0) {
1080 		ondly = 0;
1081 		while (FDTESTC(FDB_READY) == 0) {
1082 			delay(1000);
1083 			if (++ondly >= 1000)
1084 				break;
1085 		}
1086 	}
1087 	sc->flags |= FDF_MOTORON;
1088 
1089 	ncyl = trk / FDNHEADS;
1090 	nside = trk % FDNHEADS;
1091 
1092 	if (sc->curcyl == ncyl && fdc_side == nside)
1093 		return;
1094 
1095 	if (towrite)
1096 		sc->flags |= FDF_WRITEWAIT;
1097 
1098 #ifdef FDDEBUG
1099 	printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1100 	    trk % FDNHEADS, towrite);
1101 #endif
1102 	nstep = ncyl - sc->curcyl;
1103 	if (nstep) {
1104 		/*
1105 		 * figure direction
1106 		 */
1107 		if (nstep > 0 && ncyl != 0) {
1108 			sdir = FDSTEPIN;
1109 			FDSETDIR(1);
1110 		} else {
1111 			nstep = -nstep;
1112 			sdir = FDSTEPOUT;
1113 			FDSETDIR(0);
1114 		}
1115 		if (ncyl == 0) {
1116 			/*
1117 			 * either just want cylinder 0 or doing
1118 			 * a calibrate.
1119 			 */
1120 			nstep = 256;
1121 			while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1122 				FDSTEP;
1123 				delay(sc->stepdelay);
1124 			}
1125 			if (nstep < 0)
1126 				sc->flags |= FDF_NOTRACK0;
1127 		} else {
1128 			/*
1129 			 * step the needed amount amount.
1130 			 */
1131 			while (nstep--) {
1132 				FDSTEP;
1133 				delay(sc->stepdelay);
1134 			}
1135 		}
1136 		/*
1137 		 * if switched directions
1138 		 * allow drive to settle.
1139 		 */
1140 		if (sc->pstepdir != sdir)
1141 			delay(FDSETTLEDELAY);
1142 		sc->pstepdir = sdir;
1143 		sc->curcyl = ncyl;
1144 	}
1145 	if (nside == fdc_side)
1146 		return;
1147 	/*
1148 	 * select side
1149 	 */
1150 	fdc_side = nside;
1151 	FDSETHEAD(nside);
1152 	delay(FDPRESIDEDELAY);
1153 }
1154 
1155 void
1156 fdselunit(struct fd_softc *sc)
1157 {
1158 	FDDESELECT(FDCUNITMASK);		/* deselect all */
1159 	FDSETMOTOR(sc->flags & FDF_MOTORON);	/* set motor to unit's state */
1160 	delay(1);
1161 	FDSELECT(sc->unitmask);			/* select unit */
1162 	delay(1);
1163 }
1164 
1165 /*
1166  * process next buf on device queue.
1167  * normall sequence of events:
1168  * fdstart() -> fddmastart();
1169  * fdidxintr();
1170  * fdintr() -> fddmadone() -> fddone();
1171  * if the track is in the cache then fdstart() will short-circuit
1172  * to fddone() else if the track cache is dirty it will flush.  If
1173  * the buf is not an entire track it will cache the requested track.
1174  */
1175 void
1176 fdstart(struct fd_softc *sc)
1177 {
1178 	int trk, error, write;
1179 	struct buf *bp, *dp;
1180 	int changed;
1181 
1182 #ifdef FDDEBUG
1183 	printf("fdstart: unit %d\n", sc->hwunit);
1184 #endif
1185 
1186 	/*
1187 	 * if DMA'ing just return. we must have been called from fdstartegy.
1188 	 */
1189 	if (fdc_indma)
1190 		return;
1191 
1192 	/*
1193 	 * get next buf if there.
1194 	 */
1195 	dp = &sc->curbuf;
1196 	if ((bp = bufq_peek(sc->bufq)) == NULL) {
1197 #ifdef FDDEBUG
1198 		printf("  nothing to do\n");
1199 #endif
1200 		return;
1201 	}
1202 
1203 	/*
1204 	 * Mark us as busy now, in case fddone() gets called in one
1205 	 * of the cases below.
1206 	 */
1207 	disk_busy(&sc->dkdev);
1208 
1209 	/*
1210 	 * make sure same disk is loaded
1211 	 */
1212 	fdselunit(sc);
1213 	changed = FDTESTC(FDB_CHANGED);
1214 	FDDESELECT(sc->unitmask);
1215 	if (changed) {
1216 		/*
1217 		 * disk missing, invalidate all future io on
1218 		 * this unit until re-open()'ed also invalidate
1219 		 * all current io
1220 		 */
1221 printf("fdstart: disk changed\n");
1222 #ifdef FDDEBUG
1223 		printf("  disk was removed invalidating all io\n");
1224 #endif
1225 		sc->flags &= ~FDF_HAVELABEL;
1226 		for (;;) {
1227 			bp = bufq_get(sc->bufq);
1228 			bp->b_error = EIO;
1229 			if (bufq_peek(sc->bufq) == NULL)
1230 				break;
1231 			biodone(bp);
1232 		}
1233 		/*
1234 		 * do fddone() on last buf to allow other units to start.
1235 		 */
1236 		bufq_put(sc->bufq, bp);
1237 		fddone(sc);
1238 		return;
1239 	}
1240 
1241 	/*
1242 	 * we have a valid buf, setup our local version
1243 	 * we use this count to allow reading over multiple tracks.
1244 	 * into a single buffer
1245 	 */
1246 	dp->b_bcount = bp->b_bcount;
1247 	dp->b_blkno = bp->b_blkno;
1248 	dp->b_data = bp->b_data;
1249 	dp->b_flags = bp->b_flags;
1250 	dp->b_resid = 0;
1251 
1252 	if (bp->b_flags & B_READ)
1253 		write = 0;
1254 	else if (FDTESTC(FDB_PROTECT) == 0)
1255 		write = 1;
1256 	else {
1257 		error = EPERM;
1258 		goto done;
1259 	}
1260 
1261 	/*
1262 	 * figure trk given blkno
1263 	 */
1264 	trk = bp->b_blkno / sc->nsectors;
1265 
1266 	/*
1267 	 * check to see if same as currently cached track
1268 	 * if so we need to do no DMA read.
1269 	 */
1270 	if (trk == sc->cachetrk) {
1271 		fddone(sc);
1272 		return;
1273 	}
1274 
1275 	/*
1276 	 * if we will be overwriting the entire cache, don't bother to
1277 	 * fetch it.
1278 	 */
1279 	if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1280 	    bp->b_blkno % sc->nsectors == 0) {
1281 		if (sc->flags & FDF_DIRTY)
1282 			sc->flags |= FDF_JUSTFLUSH;
1283 		else {
1284 			sc->cachetrk = trk;
1285 			fddone(sc);
1286 			return;
1287 		}
1288 	}
1289 
1290 	/*
1291 	 * start DMA read of `trk'
1292 	 */
1293 	fddmastart(sc, trk);
1294 	return;
1295 done:
1296 	bp->b_error = error;
1297 	fddone(sc);
1298 }
1299 
1300 /*
1301  * continue a started operation on next track. always begin at
1302  * sector 0 on the next track.
1303  */
1304 void
1305 fdcont(struct fd_softc *sc)
1306 {
1307 	struct buf *dp, *bp;
1308 	int trk, write;
1309 
1310 	dp = &sc->curbuf;
1311 	bp = bufq_peek(sc->bufq);
1312 	dp->b_data = (char*)dp->b_data + (dp->b_bcount - bp->b_resid);
1313 	dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1314 	dp->b_bcount = bp->b_resid;
1315 
1316 	/*
1317 	 * figure trk given blkno
1318 	 */
1319 	trk = dp->b_blkno / sc->nsectors;
1320 #ifdef DEBUG
1321 	if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1322 		panic("fdcont: confused");
1323 #endif
1324 	if (dp->b_flags & B_READ)
1325 		write = 0;
1326 	else
1327 		write = 1;
1328 	/*
1329 	 * if we will be overwriting the entire cache, don't bother to
1330 	 * fetch it.
1331 	 */
1332 	if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1333 		if (sc->flags & FDF_DIRTY)
1334 			sc->flags |= FDF_JUSTFLUSH;
1335 		else {
1336 			sc->cachetrk = trk;
1337 			fddone(sc);
1338 			return;
1339 		}
1340 	}
1341 	/*
1342 	 * start DMA read of `trk'
1343 	 */
1344 	fddmastart(sc, trk);
1345 	return;
1346 }
1347 
1348 void
1349 fddmastart(struct fd_softc *sc, int trk)
1350 {
1351 	int adkmask, ndmaw, write, dmatrk;
1352 
1353 #ifdef FDDEBUG
1354 	printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1355 	    trk / FDNHEADS, trk % FDNHEADS);
1356 #endif
1357 	/*
1358 	 * flush the cached track if dirty else read requested track.
1359 	 */
1360 	if (sc->flags & FDF_DIRTY) {
1361 		fdcachetoraw(sc);
1362 		ndmaw = sc->type->nwritew;
1363 		dmatrk = sc->cachetrk;
1364 		write = 1;
1365 	} else {
1366 		ndmaw = sc->type->nreadw;
1367 		dmatrk = trk;
1368 		write = 0;
1369 	}
1370 
1371 #ifdef FDDEBUG
1372 	printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1373 #endif
1374 	sc->cachetrk = trk;
1375 	fdc_indma = sc;
1376 	fdsetpos(sc, dmatrk, write);
1377 
1378 	/*
1379 	 * setup dma stuff
1380 	 */
1381 	if (write == 0) {
1382 		custom.adkcon = ADKF_MSBSYNC;
1383 		custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1384 		custom.dsksync = FDMFMSYNC;
1385 	} else {
1386 		custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1387 		    ADKF_MSBSYNC;
1388 		adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1389 		if (dmatrk >= sc->type->precomp[0])
1390 			adkmask |= ADKF_PRECOMP0;
1391 		if (dmatrk >= sc->type->precomp[1])
1392 			adkmask |= ADKF_PRECOMP1;
1393 		custom.adkcon = adkmask;
1394 	}
1395 	custom.dskpt = (u_char *)kvtop(fdc_dmap);
1396 
1397 	/*
1398 	 * If writing an MSDOS track, activate disk index pulse
1399 	 * interrupt, DMA will be started in the intr routine fdidxintr()
1400 	 * Otherwise, start the DMA here.
1401 	 */
1402 	if (write && sc->openpart == FDMSDOSPART) {
1403 		fdc_dmalen = ndmaw;
1404 		fdc_dmawrite = write;
1405 		ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1406 	} else {
1407 		FDDMASTART(ndmaw, write);
1408 		fdc_dmalen = 0;
1409 	}
1410 
1411 #ifdef FDDEBUG
1412 	printf("  DMA started\n");
1413 #endif
1414 }
1415 
1416 /*
1417  * recalibrate the drive
1418  */
1419 void
1420 fdcalibrate(void *arg)
1421 {
1422 	struct fd_softc *sc;
1423 	static int loopcnt;
1424 
1425 	sc = arg;
1426 
1427 	if (loopcnt == 0) {
1428 		/*
1429 		 * seek cyl 0
1430 		 */
1431 		fdc_indma = sc;
1432 		sc->stepdelay += 900;
1433 		if (sc->cachetrk > 1)
1434 			fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1435 		sc->stepdelay -= 900;
1436 	}
1437 	if (loopcnt++ & 1)
1438 		fdsetpos(sc, sc->cachetrk, 0);
1439 	else
1440 		fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1441 	/*
1442 	 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and DMA
1443 	 */
1444 	if (loopcnt < 8)
1445 		callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc);
1446 	else {
1447 		loopcnt = 0;
1448 		fdc_indma = NULL;
1449 		callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1450 		fddmastart(sc, sc->cachetrk);
1451 	}
1452 }
1453 
1454 void
1455 fddmadone(struct fd_softc *sc, int timeo)
1456 {
1457 #ifdef FDDEBUG
1458 	printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1459 #endif
1460 	fdc_indma = NULL;
1461 	callout_stop(&sc->motor_ch);
1462 	FDDMASTOP;
1463 
1464 	/*
1465 	 * guarantee the drive has been at current head and cyl
1466 	 * for at least FDWRITEDELAY after a write.
1467 	 */
1468 	if (sc->flags & FDF_WRITEWAIT) {
1469 		delay(FDWRITEDELAY);
1470 		sc->flags &= ~FDF_WRITEWAIT;
1471 	}
1472 
1473 	if ((sc->flags & FDF_MOTOROFF) == 0) {
1474 		/*
1475 		 * motor runs for 1.5 seconds after last DMA
1476 		 */
1477 		callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1478 	}
1479 	if (sc->flags & FDF_DIRTY) {
1480 		/*
1481 		 * if buffer dirty, the last DMA cleaned it
1482 		 */
1483 		sc->flags &= ~FDF_DIRTY;
1484 		if (timeo)
1485 			aprint_error_dev(sc->sc_dev,
1486 			    "write of track cache timed out.\n");
1487 		if (sc->flags & FDF_JUSTFLUSH) {
1488 			sc->flags &= ~FDF_JUSTFLUSH;
1489 			/*
1490 			 * we are done DMA'ing
1491 			 */
1492 			fddone(sc);
1493 			return;
1494 		}
1495 		/*
1496 		 * load the cache
1497 		 */
1498 		fddmastart(sc, sc->cachetrk);
1499 		return;
1500 	}
1501 #ifdef FDDEBUG
1502 	else if (sc->flags & FDF_MOTOROFF)
1503 		panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1504 #endif
1505 
1506 	/*
1507 	 * cache loaded decode it into cache buffer
1508 	 */
1509 	if (timeo == 0 && fdrawtocache(sc) == 0)
1510 		sc->retried = 0;
1511 	else {
1512 #ifdef FDDEBUG
1513 		if (timeo)
1514 			aprint_debug_dev(sc->sc_dev,
1515 			    "fddmadone: cache load timed out.\n");
1516 #endif
1517 		if (sc->retried >= sc->retries) {
1518 			sc->retried = 0;
1519 			sc->cachetrk = -1;
1520 		} else {
1521 			sc->retried++;
1522 			/*
1523 			 * this will be restarted at end of calibrate loop.
1524 			 */
1525 			callout_stop(&sc->motor_ch);
1526 			fdcalibrate(sc);
1527 			return;
1528 		}
1529 	}
1530 	fddone(sc);
1531 }
1532 
1533 void
1534 fddone(struct fd_softc *sc)
1535 {
1536 	struct buf *dp, *bp;
1537 	char *data;
1538 	int sz;
1539 
1540 #ifdef FDDEBUG
1541 	printf("fddone: unit %d\n", sc->hwunit);
1542 #endif
1543 	/*
1544 	 * check to see if unit is just flushing the cache,
1545 	 * that is we have no io queued.
1546 	 */
1547 	if (sc->flags & FDF_MOTOROFF)
1548 		goto nobuf;
1549 
1550 	dp = &sc->curbuf;
1551 	if ((bp = bufq_peek(sc->bufq)) == NULL)
1552 		panic ("fddone");
1553 	/*
1554 	 * check for an error that may have occurred
1555 	 * while getting the track.
1556 	 */
1557 	if (sc->cachetrk == -1) {
1558 		sc->retried = 0;
1559 		bp->b_error = EIO;
1560 	} else if (bp->b_error == 0) {
1561 		data = sc->cachep;
1562 		/*
1563 		 * get offset of data in track cache and limit
1564 		 * the copy size to not exceed the cache's end.
1565 		 */
1566 		data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1567 		sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1568 		sz *= FDSECSIZE;
1569 		sz = min(dp->b_bcount, sz);
1570 		if (bp->b_flags & B_READ)
1571 			memcpy(dp->b_data, data, sz);
1572 		else {
1573 			memcpy(data, dp->b_data, sz);
1574 			sc->flags |= FDF_DIRTY;
1575 		}
1576 		bp->b_resid = dp->b_bcount - sz;
1577 		if (bp->b_resid == 0) {
1578 			bp->b_error = 0;
1579 		} else {
1580 			/*
1581 			 * not done yet need to read next track
1582 			 */
1583 			fdcont(sc);
1584 			return;
1585 		}
1586 	}
1587 	/*
1588 	 * remove from queue.
1589 	 */
1590 	(void)bufq_get(sc->bufq);
1591 
1592 	disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid),
1593 	    (bp->b_flags & B_READ));
1594 
1595 	biodone(bp);
1596 nobuf:
1597 	fdfindwork(device_unit(sc->sc_dev));
1598 }
1599 
1600 void
1601 fdfindwork(int unit)
1602 {
1603 	struct fd_softc *ssc, *sc;
1604 	int i, last;
1605 
1606 	/*
1607 	 * first see if we have any fdopen()'s waiting
1608 	 */
1609 	if (fdc_wantwakeup) {
1610 		wakeup(fdopen);
1611 		fdc_wantwakeup--;
1612 		return;
1613 	}
1614 
1615 	/*
1616 	 * start next available unit, linear search from the next unit
1617 	 * wrapping and finally this unit.
1618 	 */
1619 	last = 0;
1620 	ssc = NULL;
1621 	for (i = unit + 1; last == 0; i++) {
1622 		if (i == unit)
1623 			last = 1;
1624 		if (i >= fd_cd.cd_ndevs) {
1625 			i = -1;
1626 			continue;
1627 		}
1628 		if ((sc = device_lookup_private(&fd_cd, i)) == NULL)
1629 			continue;
1630 
1631 		/*
1632 		 * if unit has requested to be turned off
1633 		 * and it has no buf's queued do it now
1634 		 */
1635 		if (sc->flags & FDF_MOTOROFF) {
1636 			if (bufq_peek(sc->bufq) == NULL)
1637 				fdmotoroff(sc);
1638 			else {
1639 				/*
1640 				 * we gained a buf request while
1641 				 * we waited, forget the motoroff
1642 				 */
1643 				sc->flags &= ~FDF_MOTOROFF;
1644 			}
1645 			/*
1646 			 * if we now have DMA unit must have needed
1647 			 * flushing, quit
1648 			 */
1649 			if (fdc_indma)
1650 				return;
1651 		}
1652 		/*
1653 		 * if we have no start unit and the current unit has
1654 		 * io waiting choose this unit to start.
1655 		 */
1656 		if (ssc == NULL && bufq_peek(sc->bufq) != NULL)
1657 			ssc = sc;
1658 	}
1659 	if (ssc)
1660 		fdstart(ssc);
1661 }
1662 
1663 /*
1664  * min byte count to whats left of the track in question
1665  */
1666 void
1667 fdminphys(struct buf *bp)
1668 {
1669 	struct fd_softc *sc;
1670 	int sec, toff, tsz;
1671 
1672 	if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1673 		panic("fdminphys: couldn't get softc");
1674 
1675 	sec = bp->b_blkno % sc->nsectors;
1676 
1677 	toff = sec * FDSECSIZE;
1678 	tsz = sc->nsectors * FDSECSIZE;
1679 #ifdef FDDEBUG
1680 	printf("fdminphys: before %ld", bp->b_bcount);
1681 #endif
1682 	bp->b_bcount = min(bp->b_bcount, tsz - toff);
1683 #ifdef FDDEBUG
1684 	printf(" after %ld\n", bp->b_bcount);
1685 #endif
1686 	minphys(bp);
1687 }
1688 
1689 /*
1690  * encode the track cache into raw MFM ready for DMA
1691  * when we go to multiple disk formats, this will call type dependent
1692  * functions
1693  */
1694 void fdcachetoraw(struct fd_softc *sc)
1695 {
1696 	if (sc->openpart == FDMSDOSPART)
1697 		mscachetoraw(sc);
1698 	else
1699 		amcachetoraw(sc);
1700 }
1701 
1702 /*
1703  * decode raw MFM from DMA into units track cache.
1704  * when we go to multiple disk formats, this will call type dependent
1705  * functions
1706  */
1707 int
1708 fdrawtocache(struct fd_softc *sc)
1709 {
1710 
1711 	if (sc->openpart == FDMSDOSPART)
1712 		return(msrawtocache(sc));
1713 	else
1714 		return(amrawtocache(sc));
1715 }
1716 
1717 void
1718 amcachetoraw(struct fd_softc *sc)
1719 {
1720 	static u_long mfmnull[4];
1721 	u_long *rp, *crp, *dp, hcksum, dcksum, info;
1722 	int sec, i;
1723 
1724 	rp = fdc_dmap;
1725 
1726 	/*
1727 	 * not yet one sector (- 1 long) gap.
1728 	 * for now use previous drivers values
1729 	 */
1730 	for (i = 0; i < sc->type->gap; i++)
1731 		*rp++ = 0xaaaaaaaa;
1732 	/*
1733 	 * process sectors
1734 	 */
1735 	dp = sc->cachep;
1736 	info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1737 	for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1738 		hcksum = dcksum = 0;
1739 		/*
1740 		 * sector format
1741 		 *	offset		description
1742 		 *-----------------------------------
1743 		 *  0			null
1744 		 *  1			sync
1745 		 * oddbits	evenbits
1746 		 *----------------------
1747 		 *  2		3	[0xff]b [trk]b [sec]b [togap]b
1748 		 *  4-7		8-11	null
1749 		 * 12		13	header cksum [2-11]
1750 		 * 14		15	data cksum [16-271]
1751 		 * 16-143	144-271	data
1752 		 */
1753 		*rp = 0xaaaaaaaa;
1754 		if (*(rp - 1) & 0x1)
1755 			*rp &= 0x7fffffff;	/* clock bit correction */
1756 		rp++;
1757 		*rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1758 		rp = mfmblkencode(&info, rp, &hcksum, 1);
1759 		rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1760 		rp = mfmblkencode(&hcksum, rp, NULL, 1);
1761 
1762 		crp = rp;
1763 		rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1764 		dp += FDSECLWORDS;
1765 		crp = mfmblkencode(&dcksum, crp, NULL, 1);
1766 		if (*(crp - 1) & 0x1)
1767 			*crp &= 0x7fffffff;	/* clock bit correction */
1768 		else if ((*crp & 0x40000000) == 0)
1769 			*crp |= 0x80000000;
1770 	}
1771 	*rp = 0xaaa80000;
1772 	if (*(rp - 1) & 0x1)
1773 		*rp &= 0x7fffffff;
1774 }
1775 
1776 u_long *
1777 fdfindsync(u_long *rp, u_long *ep)
1778 {
1779 	u_short *sp;
1780 
1781 	sp = (u_short *)rp;
1782 	while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1783 		sp++;
1784 	while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1785 		sp++;
1786 	if ((u_long *)sp < ep)
1787 		return((u_long *)sp);
1788 	return(NULL);
1789 }
1790 
1791 int
1792 amrawtocache(struct fd_softc *sc)
1793 {
1794 	u_long mfmnull[4];
1795 	u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1796 	int cnt, doagain;
1797 
1798 	doagain = 1;
1799 	srp = rp = fdc_dmap;
1800 	erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1801 	cnt = 0;
1802 again:
1803 	if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1804 #ifdef DIAGNOSTIC
1805 		aprint_error_dev(sc->sc_dev, "corrupted track (%d) data.\n",
1806 		    sc->cachetrk);
1807 #endif
1808 		return(-1);
1809 	}
1810 
1811 	/*
1812 	 * process sectors
1813 	 */
1814 	for (; cnt < sc->nsectors; cnt++) {
1815 		hcksum = dcksum = 0;
1816 		rp = mfmblkdecode(rp, &info, &hcksum, 1);
1817 		rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1818 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1819 		if (cktmp != hcksum) {
1820 #ifdef FDDEBUG
1821 			printf("  info 0x%lx hchksum 0x%lx trkhcksum 0x%lx\n",
1822 			    info, hcksum, cktmp);
1823 #endif
1824 			goto again;
1825 		}
1826 		if (((info >> 16) & 0xff) != sc->cachetrk) {
1827 #ifdef DEBUG
1828 			aprint_debug_dev(sc->sc_dev,
1829 			    "incorrect track found: 0x%lx %d\n",
1830 			    info, sc->cachetrk);
1831 #endif
1832 			goto again;
1833 		}
1834 #ifdef FDDEBUG
1835 		printf("  info 0x%lx\n", info);
1836 #endif
1837 
1838 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1839 		dp = sc->cachep;
1840 		dp += FDSECLWORDS * ((info >> 8) & 0xff);
1841 		crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1842 		if (cktmp != dcksum) {
1843 #ifdef FDDEBUG
1844 			printf("  info 0x%lx dchksum 0x%lx trkdcksum 0x%lx\n",
1845 			    info, dcksum, cktmp);
1846 #endif
1847 			goto again;
1848 		}
1849 
1850 		/*
1851 		 * if we are at gap then we can no longer be sure
1852 		 * of correct sync marks
1853 		 */
1854 		if ((info & 0xff) == 1)
1855 			doagain = 1;
1856 		else
1857 			doagain = 0;
1858 		srp = rp = fdfindsync(crp, erp);
1859 	}
1860 	return(0);
1861 }
1862 
1863 void
1864 mscachetoraw(struct fd_softc *sc)
1865 {
1866 	u_short *rp, *erp, crc;
1867 	u_char *cp, tb[5];
1868 	int sec, i;
1869 
1870 	rp = (u_short *)fdc_dmap;
1871 	erp = rp + sc->type->nwritew;
1872 	cp = sc->cachep;
1873 
1874 	/*
1875 	 * initial track filler  (828 * GAP1)
1876 	 */
1877 	for (i = 0; i < sc->type->gap; i++) {
1878 		*rp++ = FDMFMGAP1;
1879 		*rp++ = FDMFMGAP1;
1880 	}
1881 
1882 	for (sec = 0; sec < sc->nsectors; sec++) {
1883 
1884 		/*
1885 		 * leading sector gap
1886 		 * (12 * GAP2) + (3 * SYNC)
1887 		 */
1888 		for (i = 0; i < 12; i++)
1889 			*rp++ = FDMFMGAP2;
1890 		*rp++ = FDMFMSYNC;
1891 		*rp++ = FDMFMSYNC;
1892 		*rp++ = FDMFMSYNC;
1893 
1894 		/*
1895 		 * sector information
1896 		 * (ID) + track + side + sector + sector size + CRC16
1897 		 */
1898 		*rp++ = FDMFMID;
1899 		tb[0] = sc->cachetrk / FDNHEADS;
1900 		tb[1] = sc->cachetrk % FDNHEADS;
1901 		tb[2] = sec + 1;
1902 		i = sc->bytespersec;
1903 		tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1904 		rp = msblkencode(rp, tb, 4, &crc);
1905 		tb[0] = crc >> 8;
1906 		tb[1] = crc & 0xff;
1907 		tb[2] = 0x4e; /* GAP1 decoded */
1908 		rp = msblkencode(rp, tb, 3, 0);
1909 
1910 		/*
1911 		 * sector info/data gap
1912 		 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1913 		 */
1914 		for (i = 0; i < 21; i++)
1915 			*rp++ = FDMFMGAP1;
1916 		for (i = 0; i < 12; i++)
1917 			*rp++ = FDMFMGAP2;
1918 		*rp++ = FDMFMSYNC;
1919 		*rp++ = FDMFMSYNC;
1920 		*rp++ = FDMFMSYNC;
1921 
1922 		/*
1923 		 * sector data
1924 		 * (DATA) + ...data... + CRC16
1925 		 */
1926 		*rp++ = FDMFMDATA;
1927 		rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1928 		cp += sc->bytespersec;
1929 		tb[0] = crc >> 8;
1930 		tb[1] = crc & 0xff;
1931 		tb[2] = 0x4e; /* GAP3 decoded */
1932 		rp = msblkencode(rp, tb, 3, 0);
1933 
1934 		/*
1935 		 * trailing sector gap
1936 		 * (80 * GAP3)
1937 		 */
1938 		for (i = 0; i < 79; i++)
1939 			*rp++ = FDMFMGAP3;
1940 	}
1941 
1942 	/*
1943 	 * fill rest of track with GAP3
1944 	 */
1945 	while (rp != erp)
1946 		*rp++ = FDMFMGAP3;
1947 
1948 }
1949 
1950 int
1951 msrawtocache(struct fd_softc *sc)
1952 {
1953 	u_short *rp, *erp;
1954 	u_char tb[5], *cp;
1955 	int ct, sec, retry;
1956 
1957 	rp = (u_short *)fdc_dmap;
1958 	erp = rp + sc->type->nreadw;
1959 	cp = sc->cachep;
1960 
1961 	for (ct = 0; ct < sc->nsectors; ct++) {
1962 		retry = 1;
1963 		do {
1964 			/*
1965 			 * skip leading gap to sync
1966 			 */
1967 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
1968 #ifdef DIAGNOSTIC
1969 				aprint_normal_dev(sc->sc_dev,
1970 				    "corrupted track (%d) data.\n",
1971 				    sc->cachetrk);
1972 #endif
1973 				return(-1);
1974 			}
1975 
1976 			/*
1977 			 * Grab sector info
1978 			 */
1979 			if (*rp++ != FDMFMID)
1980 				continue;
1981 			rp = msblkdecode(rp, tb, 4);
1982 #ifdef FDDEBUG
1983 			printf("sector id: sector %d, track %d, side %d,"
1984 			    "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
1985 #endif
1986 			if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
1987 			    tb[2] > sc->nsectors)
1988 				continue;
1989 
1990 			sec = tb[2];
1991 			sc->bytespersec = 128 << tb[3];
1992 			rp += 2; /* skip CRC-16 */
1993 
1994 			/*
1995 			 * skip gap and read in data
1996 			 */
1997 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
1998 				return(-1);
1999 			if (*rp++ != FDMFMDATA)
2000 				continue;
2001 			rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
2002 			    sc->bytespersec);
2003 			rp += 2; /* skip CRC-16 */
2004 
2005 			retry = 0;
2006 		} while (retry);
2007 	}
2008 	return(0);
2009 }
2010 
2011 /*
2012  * encode len longwords of `dp' data in amiga mfm block format (`rp')
2013  * this format specified that the odd bits are at current pos and even
2014  * bits at len + current pos
2015  */
2016 u_long *
2017 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len)
2018 {
2019 	u_long *sdp, *edp, d, dtmp, correct;
2020 
2021 	sdp = dp;
2022 	edp = dp + len;
2023 
2024 	if (*(rp - 1) & 0x1)
2025 		correct = 1;
2026 	else
2027 		correct = 0;
2028 	/*
2029 	 * do odd bits
2030 	 */
2031 	while (dp < edp) {
2032 		d = (*dp >> 1) & 0x55555555;	/* remove clock bits */
2033 		dtmp = d ^ 0x55555555;
2034 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2035 		/*
2036 		 * correct upper clock bit if needed
2037 		 */
2038 		if (correct)
2039 			d &= 0x7fffffff;
2040 		if (d & 0x1)
2041 			correct = 1;
2042 		else
2043 			correct = 0;
2044 		/*
2045 		 * do checksums and store in raw buffer
2046 		 */
2047 		if (cp)
2048 			*cp ^= d;
2049 		*rp++ = d;
2050 		dp++;
2051 	}
2052 	/*
2053 	 * do even bits
2054 	 */
2055 	dp = sdp;
2056 	while (dp < edp) {
2057 		d = *dp & 0x55555555;	/* remove clock bits */
2058 		dtmp = d ^ 0x55555555;
2059 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2060 		/*
2061 		 * correct upper clock bit if needed
2062 		 */
2063 		if (correct)
2064 			d &= 0x7fffffff;
2065 		if (d & 0x1)
2066 			correct = 1;
2067 		else
2068 			correct = 0;
2069 		/*
2070 		 * do checksums and store in raw buffer
2071 		 */
2072 		if (cp)
2073 			*cp ^= d;
2074 		*rp++ = d;
2075 		dp++;
2076 	}
2077 	if (cp)
2078 		*cp &= 0x55555555;
2079 	return(rp);
2080 }
2081 
2082 /*
2083  * decode len longwords of `dp' data in amiga mfm block format (`rp')
2084  * this format specified that the odd bits are at current pos and even
2085  * bits at len + current pos
2086  */
2087 u_long *
2088 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len)
2089 {
2090 	u_long o, e;
2091 	int cnt;
2092 
2093 	cnt = len;
2094 	while (cnt--) {
2095 		o = *rp;
2096 		e = *(rp + len);
2097 		if (cp) {
2098 			*cp ^= o;
2099 			*cp ^= e;
2100 		}
2101 		o &= 0x55555555;
2102 		e &= 0x55555555;
2103 		*dp++ = (o << 1) | e;
2104 		rp++;
2105 	}
2106 	if (cp)
2107 		*cp &= 0x55555555;
2108 	return(rp + len);
2109 }
2110 
2111 /*
2112  * decode len words in standard MFM format to len bytes
2113  * of data.
2114  */
2115 u_short *
2116 msblkdecode(u_short *rp, u_char *cp, int len)
2117 {
2118 	while (len--) {
2119 		*cp++ = msdecode[*rp & 0x7f] |
2120 		    (msdecode[(*rp >> 8) & 0x7f] << 4);
2121 		rp++;
2122 	}
2123 
2124 	return(rp);
2125 }
2126 
2127 /*
2128  * encode len bytes of data into len words in standard MFM format.
2129  * If a pointer is supplied for crc, calculate the CRC-16 of the data
2130  * as well.
2131  */
2132 u_short *
2133 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc)
2134 {
2135 	u_short td;
2136 	u_short mycrc;
2137 
2138 	/* preload crc for header (4 bytes)
2139 	 * or data (anything else)
2140 	 */
2141 	mycrc = (len == 4) ? 0xb230 : 0xe295;
2142 
2143 	while (len--) {
2144 		td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2145 
2146 		/* Check for zeros in top bit of encode and bottom
2147 		 * bit of previous encode.  if so, slap a one in betweem
2148 		 * them.
2149 		 */
2150 		if ((td & 0x140) == 0)
2151 			td |= 0x80;
2152 		if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2153 			td |= 0x8000;
2154 
2155 		*rp++ = td;
2156 
2157 		/*
2158 		 * calc crc if requested
2159 		 */
2160 		if (crc)
2161 			mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2162 
2163 		cp++;
2164 	}
2165 
2166 	if (crc)
2167 		*crc = mycrc;
2168 
2169 	return(rp);
2170 }
2171