xref: /netbsd/sys/arch/amiga/dev/fd.c (revision bf9ec67e)
1 /*	$NetBSD: fd.c,v 1.50 2002/01/28 09:56:54 aymeric 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 1.50 2002/01/28 09:56:54 aymeric 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/device.h>
45 #include <sys/ioctl.h>
46 #include <sys/fcntl.h>
47 #include <sys/disklabel.h>
48 #include <sys/disk.h>
49 #include <sys/dkbad.h>
50 #include <sys/proc.h>
51 #include <machine/cpu.h>
52 #include <amiga/amiga/device.h>
53 #include <amiga/amiga/custom.h>
54 #include <amiga/amiga/cia.h>
55 #include <amiga/amiga/cc.h>
56 
57 #include <sys/conf.h>
58 #include <machine/conf.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 	u_int precomp[2];	/* 1st and 2nd precomp values */
140 	char *desc;		/* description of drive type (useq) */
141 };
142 
143 /*
144  * floppy disk device data
145  */
146 struct fd_softc {
147 	struct device sc_dv;	/* generic device info; must come first */
148 	struct disk dkdev;	/* generic disk info */
149 	struct buf_queue 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(struct device *, struct cfdata *, void *);
193 void	fdcattach(struct device *, struct device *, void *);
194 int	fdcprint(void *, const char *);
195 int	fdmatch(struct device *, struct cfdata *, void *);
196 void	fdattach(struct device *, struct device *, void *);
197 
198 void	fdintr(int);
199 void	fdidxintr(void);
200 void	fdstrategy(struct buf *);
201 int	fdloaddisk(struct fd_softc *);
202 void	fdgetdefaultlabel(struct fd_softc *, struct disklabel *, int);
203 int	fdgetdisklabel(struct fd_softc *, dev_t);
204 int	fdsetdisklabel(struct fd_softc *, struct disklabel *);
205 int	fdputdisklabel(struct fd_softc *, dev_t);
206 struct	fdtype * fdcgetfdtype(int);
207 void	fdmotoroff(void *);
208 void	fdsetpos(struct fd_softc *, int, int);
209 void	fdselunit(struct fd_softc *);
210 void	fdstart(struct fd_softc *);
211 void	fdcont(struct fd_softc *);
212 void	fddmastart(struct fd_softc *, int);
213 void	fdcalibrate(void *);
214 void	fddmadone(struct fd_softc *, int);
215 void	fddone(struct fd_softc *);
216 void	fdfindwork(int);
217 void	fdminphys(struct buf *);
218 void	fdcachetoraw(struct fd_softc *);
219 void	amcachetoraw(struct fd_softc *);
220 int	amrawtocache(struct fd_softc *);
221 u_long	*fdfindsync(u_long *, u_long *);
222 int	fdrawtocache(struct fd_softc *);
223 void	mscachetoraw(struct fd_softc *);
224 int	msrawtocache(struct fd_softc *);
225 u_long	*mfmblkencode(u_long *, u_long *, u_long *, int);
226 u_long	*mfmblkdecode(u_long *, u_long *, u_long *, int);
227 u_short	*msblkdecode(u_short *, u_char *, int);
228 u_short	*msblkencode(u_short *, u_char *, int, u_short *);
229 
230 struct dkdriver fddkdriver = { fdstrategy };
231 
232 /*
233  * read size is (nsectors + 1) * mfm secsize + gap bytes + 2 shorts
234  * write size is nsectors * mfm secsize + gap bytes + 3 shorts
235  * the extra shorts are to deal with a dma hw bug in the controller
236  * they are probably too much (I belive the bug is 1 short on write and
237  * 3 bits on read) but there is no need to be cheap here.
238  */
239 #define MAXTRKSZ (22 * FDSECSIZE)
240 struct fdtype fdtype[] = {
241 	{ 0x00000000, 80, 11, 9, 7358, 6815, 414, { 80, 161 }, "3.5dd" },
242 	{ 0x55555555, 40, 11, 9, 7358, 6815, 414, { 80, 161 }, "5.25dd" },
243 	{ 0xAAAAAAAA, 80, 22, 18, 14716, 13630, 828, { 80, 161 }, "3.5hd" }
244 };
245 int nfdtype = sizeof(fdtype) / sizeof(*fdtype);
246 
247 struct cfattach fd_ca = {
248 	sizeof(struct fd_softc), fdmatch, fdattach
249 };
250 
251 extern struct cfdriver fd_cd;
252 
253 struct cfattach fdc_ca = {
254 	sizeof(struct device), fdcmatch, fdcattach
255 };
256 
257 /*
258  * all hw access through macros, this helps to hide the active low
259  * properties
260  */
261 
262 #define FDUNITMASK(unit)	(1 << (3 + (unit)))
263 
264 /*
265  * select units using mask
266  */
267 #define FDSELECT(um)	do { ciab.prb &= ~(um); } while (0)
268 
269 /*
270  * deselect units using mask
271  */
272 #define FDDESELECT(um)	do { ciab.prb |= (um); delay(1); } while (0)
273 
274 /*
275  * test hw condition bits
276  */
277 #define FDTESTC(bit)	((ciaa.pra & (1 << (bit))) == 0)
278 
279 /*
280  * set motor for select units, true motor on else off
281  */
282 #define FDSETMOTOR(on)	do { \
283 	if (on) ciab.prb &= ~CIAB_PRB_MTR; else ciab.prb |= CIAB_PRB_MTR; \
284 	} while (0)
285 
286 /*
287  * set head for select units
288  */
289 #define FDSETHEAD(head)	do { \
290 	if (head) ciab.prb &= ~CIAB_PRB_SIDE; else ciab.prb |= CIAB_PRB_SIDE; \
291 	delay(1); } while (0)
292 
293 /*
294  * select direction, true towards spindle else outwards
295  */
296 #define FDSETDIR(in)	do { \
297 	if (in) ciab.prb &= ~CIAB_PRB_DIR; else ciab.prb |= CIAB_PRB_DIR; \
298 	delay(1); } while (0)
299 
300 /*
301  * step the selected units
302  */
303 #define FDSTEP	do { \
304     ciab.prb &= ~CIAB_PRB_STEP; ciab.prb |= CIAB_PRB_STEP; \
305     } while (0)
306 
307 #define FDDMASTART(len, towrite)	do { \
308     int dmasz = (len) | ((towrite) ? DISKLEN_WRITE : 0) | DISKLEN_DMAEN; \
309     custom.dsklen = dmasz; custom.dsklen = dmasz; } while (0)
310 
311 #define FDDMASTOP	do { custom.dsklen = 0; } while (0)
312 
313 
314 int
315 fdcmatch(struct device *pdp, struct cfdata *cfp, void *auxp)
316 {
317 	static int fdc_matched = 0;
318 
319 	/* Allow only once instance. */
320 	if (matchname("fdc", auxp) == 0 || fdc_matched)
321 		return(0);
322 	if ((fdc_dmap = alloc_chipmem(DMABUFSZ)) == NULL) {
323 		printf("fdc: unable to allocate dma buffer\n");
324 		return(0);
325 	}
326 
327 	fdc_matched = 1;
328 	return(1);
329 }
330 
331 void
332 fdcattach(struct device *pdp, struct device *dp, void *auxp)
333 {
334 	struct fdcargs args;
335 
336 	printf(": dmabuf pa 0x%x", kvtop(fdc_dmap));
337 	printf(": dmabuf ka %p\n", fdc_dmap);
338 	args.unit = 0;
339 	args.type = fdcgetfdtype(args.unit);
340 
341 	fdc_side = -1;
342 	config_found(dp, &args, fdcprint);
343 	for (args.unit++; args.unit < FDMAXUNITS; args.unit++) {
344 		if ((args.type = fdcgetfdtype(args.unit)) == NULL)
345 			continue;
346 		config_found(dp, &args, fdcprint);
347 	}
348 }
349 
350 int
351 fdcprint(void *auxp, const char *pnp)
352 {
353 	struct fdcargs *fcp;
354 
355 	fcp = auxp;
356 	if (pnp)
357 		printf("fd%d at %s unit %d:", fcp->unit, pnp,
358 			fcp->type->driveid);
359 	return(UNCONF);
360 }
361 
362 /*ARGSUSED*/
363 int
364 fdmatch(struct device *pdp, struct cfdata *cfp, void *auxp)
365 {
366 	struct fdcargs *fdap;
367 
368 	fdap = auxp;
369 	if (cfp->cf_loc[FDCCF_UNIT] == fdap->unit ||
370 	    cfp->cf_loc[FDCCF_UNIT] == FDCCF_UNIT_DEFAULT)
371 		return(1);
372 
373 	return(0);
374 }
375 
376 void
377 fdattach(struct device *pdp, struct device *dp, void *auxp)
378 {
379 	struct fdcargs *ap;
380 	struct fd_softc *sc;
381 	int i;
382 
383 	ap = auxp;
384 	sc = (struct fd_softc *)dp;
385 
386 	BUFQ_INIT(&sc->bufq);
387 	callout_init(&sc->calibrate_ch);
388 	callout_init(&sc->motor_ch);
389 
390 	sc->curcyl = sc->cachetrk = -1;
391 	sc->openpart = -1;
392 	sc->type = ap->type;
393 	sc->hwunit = ap->unit;
394 	sc->unitmask = 1 << (3 + ap->unit);
395 	sc->retries = FDRETRIES;
396 	sc->stepdelay = FDSTEPDELAY;
397 	sc->bytespersec = 512;
398 	printf(" unit %d: %s %d cyl, %d head, %d sec [%d sec], 512 bytes/sec\n",
399 	    sc->hwunit, sc->type->desc, sc->type->ncylinders, FDNHEADS,
400 	    sc->type->amiga_nsectors, sc->type->msdos_nsectors);
401 
402 	/*
403 	 * Initialize and attach the disk structure.
404 	 */
405 	sc->dkdev.dk_name = sc->sc_dv.dv_xname;
406 	sc->dkdev.dk_driver = &fddkdriver;
407 	disk_attach(&sc->dkdev);
408 
409 	/*
410 	 * calibrate the drive
411 	 */
412 	fdsetpos(sc, 0, 0);
413 	fdsetpos(sc, sc->type->ncylinders, 0);
414 	fdsetpos(sc, 0, 0);
415 	fdmotoroff(sc);
416 
417 	/*
418 	 * precalc msdos MFM and CRC
419 	 */
420 	for (i = 0; i < 128; i++)
421 		msdecode[i] = 0xff;
422 	for (i = 0; i < 16; i++)
423 		msdecode[msencode[i]] = i;
424 	for (i = 0; i < 256; i++) {
425 		mscrctab[i] = (0x1021 * (i & 0xf0)) ^ (0x1021 * (i & 0x0f)) ^
426 		    (0x1021 * (i >> 4));
427 	}
428 
429 	/*
430 	 * enable disk related interrupts
431 	 */
432 	custom.dmacon = DMAF_SETCLR | DMAF_MASTER | DMAF_DISK;
433 	custom.intena = INTF_SETCLR | INTF_DSKBLK;
434 	ciab.icr = CIA_ICR_FLG;
435 }
436 
437 /*ARGSUSED*/
438 int
439 fdopen(dev_t dev, int flags, int devtype, struct proc *p)
440 {
441 	struct fd_softc *sc;
442 	int wasopen, fwork, error, s;
443 
444 	error = 0;
445 
446 	if (FDPART(dev) >= FDMAXPARTS)
447 		return(ENXIO);
448 
449 	if ((sc = getsoftc(fd_cd, FDUNIT(dev))) == NULL)
450 		return(ENXIO);
451 	if (sc->flags & FDF_NOTRACK0)
452 		return(ENXIO);
453 	if (sc->cachep == NULL)
454 		sc->cachep = malloc(MAXTRKSZ, M_DEVBUF, M_WAITOK);
455 
456 	s = splbio();
457 	/*
458 	 * if we are sleeping in fdclose(); waiting for a chance to
459 	 * shut the motor off, do a sleep here also.
460 	 */
461 	while (sc->flags & FDF_WMOTOROFF)
462 		tsleep(fdmotoroff, PRIBIO, "fdopen", 0);
463 
464 	fwork = 0;
465 	/*
466 	 * if not open let user open request type, otherwise
467 	 * ensure they are trying to open same type.
468 	 */
469 	if (sc->openpart == FDPART(dev))
470 		wasopen = 1;
471 	else if (sc->openpart == -1) {
472 		sc->openpart = FDPART(dev);
473 		wasopen = 0;
474 	} else {
475 		wasopen = 1;
476 		error = EPERM;
477 		goto done;
478 	}
479 
480 	/*
481 	 * wait for current io to complete if any
482 	 */
483 	if (fdc_indma) {
484 		fwork = 1;
485 		fdc_wantwakeup++;
486 		tsleep(fdopen, PRIBIO, "fdopen", 0);
487 	}
488 	if ((error = fdloaddisk(sc)) != 0)
489 		goto done;
490 	if ((error = fdgetdisklabel(sc, dev)) != 0)
491 		goto done;
492 #ifdef FDDEBUG
493 	printf("  open successful\n");
494 #endif
495 done:
496 	/*
497 	 * if we requested that fddone()->fdfindwork() wake us, allow it to
498 	 * complete its job now
499 	 */
500 	if (fwork)
501 		fdfindwork(FDUNIT(dev));
502 	splx(s);
503 
504 	/*
505 	 * if we were not open and we marked us so reverse that.
506 	 */
507 	if (error && wasopen == 0)
508 		sc->openpart = -1;
509 	return(error);
510 }
511 
512 /*ARGSUSED*/
513 int
514 fdclose(dev_t dev, int flags, int devtype, struct proc *p)
515 {
516 	struct fd_softc *sc;
517 	int s;
518 
519 #ifdef FDDEBUG
520 	printf("fdclose()\n");
521 #endif
522 	sc = getsoftc(fd_cd, FDUNIT(dev));
523 	s = splbio();
524 	if (sc->flags & FDF_MOTORON) {
525 		sc->flags |= FDF_WMOTOROFF;
526 		tsleep(fdmotoroff, PRIBIO, "fdclose", 0);
527 		sc->flags &= ~FDF_WMOTOROFF;
528 		wakeup(fdmotoroff);
529 	}
530 	sc->openpart = -1;
531 	splx(s);
532 	return(0);
533 }
534 
535 int
536 fdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
537 {
538 	struct fd_softc *sc;
539 	int error, wlab;
540 
541 	sc = getsoftc(fd_cd, FDUNIT(dev));
542 
543 	if ((sc->flags & FDF_HAVELABEL) == 0)
544 		return(EBADF);
545 
546 	switch (cmd) {
547 	case DIOCSBAD:
548 		return(EINVAL);
549 	case DIOCSRETRIES:
550 		if (*(int *)addr < 0)
551 			return(EINVAL);
552 		sc->retries = *(int *)addr;
553 		return(0);
554 	case DIOCSSTEP:
555 		if (*(int *)addr < FDSTEPDELAY)
556 			return(EINVAL);
557 		sc->dkdev.dk_label->d_trkseek = sc->stepdelay = *(int *)addr;
558 		return(0);
559 	case DIOCGDINFO:
560 		*(struct disklabel *)addr = *(sc->dkdev.dk_label);
561 		return(0);
562 	case DIOCGPART:
563 		((struct partinfo *)addr)->disklab = sc->dkdev.dk_label;
564 		((struct partinfo *)addr)->part =
565 		    &sc->dkdev.dk_label->d_partitions[FDPART(dev)];
566 		return(0);
567 	case DIOCSDINFO:
568 		if ((flag & FWRITE) == 0)
569 			return(EBADF);
570 		return(fdsetdisklabel(sc, (struct disklabel *)addr));
571 	case DIOCWDINFO:
572 		if ((flag & FWRITE) == 0)
573 			return(EBADF);
574 		if ((error = fdsetdisklabel(sc, (struct disklabel *)addr)) != 0)
575 			return(error);
576 		wlab = sc->wlabel;
577 		sc->wlabel = 1;
578 		error = fdputdisklabel(sc, dev);
579 		sc->wlabel = wlab;
580 		return(error);
581 	case DIOCWLABEL:
582 		if ((flag & FWRITE) == 0)
583 			return(EBADF);
584 		sc->wlabel = *(int *)addr;
585 		return(0);
586 	case DIOCGDEFLABEL:
587 		fdgetdefaultlabel(sc, (struct disklabel *)addr, FDPART(dev));
588 		return(0);
589 	default:
590 		return(ENOTTY);
591 	}
592 }
593 
594 /*
595  * no dumps to floppy disks thank you.
596  */
597 int
598 fdsize(dev_t dev)
599 {
600 	return(-1);
601 }
602 
603 int
604 fdread(dev_t dev, struct uio *uio, int flags)
605 {
606 	return (physio(fdstrategy, NULL, dev, B_READ, fdminphys, uio));
607 }
608 
609 int
610 fdwrite(dev_t dev, struct uio *uio, int flags)
611 {
612 	return (physio(fdstrategy, NULL, dev, B_WRITE, fdminphys, uio));
613 }
614 
615 
616 void
617 fdintr(int flag)
618 {
619 	int s;
620 
621 	s = splbio();
622 	if (fdc_indma)
623 		fddmadone(fdc_indma, 0);
624 	splx(s);
625 }
626 
627 void
628 fdidxintr(void)
629 {
630 	if (fdc_indma && fdc_dmalen) {
631 		/*
632 		 * turn off intr and start actual dma
633 		 */
634 		ciab.icr = CIA_ICR_FLG;
635 		FDDMASTART(fdc_dmalen, fdc_dmawrite);
636 		fdc_dmalen = 0;
637 	}
638 }
639 
640 void
641 fdstrategy(struct buf *bp)
642 {
643 	struct disklabel *lp;
644 	struct fd_softc *sc;
645 	int unit, part, s;
646 
647 	unit = FDUNIT(bp->b_dev);
648 	part = FDPART(bp->b_dev);
649 	sc = getsoftc(fd_cd, unit);
650 
651 #ifdef FDDEBUG
652 	printf("fdstrategy: 0x%x\n", bp);
653 #endif
654 	/*
655 	 * check for valid partition and bounds
656 	 */
657 	lp = sc->dkdev.dk_label;
658 	if ((sc->flags & FDF_HAVELABEL) == 0) {
659 		bp->b_error = EIO;
660 		goto bad;
661 	}
662 	if (bounds_check_with_label(bp, lp, sc->wlabel) <= 0)
663 		goto done;
664 
665 	/*
666 	 * trans count of zero or bounds check indicates io is done
667 	 * we are done.
668 	 */
669 	if (bp->b_bcount == 0)
670 		goto done;
671 
672 	bp->b_rawblkno = bp->b_blkno;
673 
674 	/*
675 	 * queue the buf and kick the low level code
676 	 */
677 	s = splbio();
678 	disksort_cylinder(&sc->bufq, bp);
679 	fdstart(sc);
680 	splx(s);
681 	return;
682 bad:
683 	bp->b_flags |= B_ERROR;
684 done:
685 	bp->b_resid = bp->b_bcount;
686 	biodone(bp);
687 }
688 
689 /*
690  * make sure disk is loaded and label is up-to-date.
691  */
692 int
693 fdloaddisk(struct fd_softc *sc)
694 {
695 	/*
696 	 * if diskchange is low step drive to 0 then up one then to zero.
697 	 */
698 	fdselunit(sc);			/* make sure the unit is selected */
699 	if (FDTESTC(FDB_CHANGED)) {
700 		fdsetpos(sc, 0, 0);
701 		sc->cachetrk = -1;		/* invalidate the cache */
702 		sc->flags &= ~FDF_HAVELABEL;
703 		fdsetpos(sc, FDNHEADS, 0);
704 		fdsetpos(sc, 0, 0);
705 		if (FDTESTC(FDB_CHANGED)) {
706 			fdmotoroff(sc);
707 			FDDESELECT(sc->unitmask);
708 			return(ENXIO);
709 		}
710 	}
711 	FDDESELECT(sc->unitmask);
712 	fdmotoroff(sc);
713 	sc->type = fdcgetfdtype(sc->hwunit);
714 	if (sc->type == NULL)
715 		return(ENXIO);
716 	if (sc->openpart == FDMSDOSPART)
717 		sc->nsectors = sc->type->msdos_nsectors;
718 	else
719 		sc->nsectors = sc->type->amiga_nsectors;
720 	return(0);
721 }
722 
723 void
724 fdgetdefaultlabel(struct fd_softc *sc, struct disklabel *lp, int part)
725 /* (variable part) XXX ick */
726 {
727 
728 	bzero(lp, sizeof(struct disklabel));
729 	lp->d_secsize = FDSECSIZE;
730 	lp->d_ntracks = FDNHEADS;
731 	lp->d_ncylinders = sc->type->ncylinders;
732 	lp->d_nsectors = sc->nsectors;
733 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
734 	lp->d_type = DTYPE_FLOPPY;
735 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
736 	lp->d_rpm = 300; 		/* good guess I suppose. */
737 	lp->d_interleave = 1;		/* should change when adding msdos */
738 	sc->stepdelay = lp->d_trkseek = FDSTEPDELAY;
739 	lp->d_bbsize = 0;
740 	lp->d_sbsize = 0;
741 	lp->d_partitions[part].p_size = lp->d_secperunit;
742 	lp->d_partitions[part].p_fstype = FS_UNUSED;
743 	lp->d_partitions[part].p_fsize = 1024;
744 	lp->d_partitions[part].p_frag = 8;
745 	lp->d_partitions[part].p_cpg = 2;	/* adosfs: reserved blocks */
746 	lp->d_npartitions = part + 1;
747 	lp->d_magic = lp->d_magic2 = DISKMAGIC;
748 	lp->d_checksum = dkcksum(lp);
749 }
750 
751 /*
752  * read disk label, if present otherwise create one
753  * return a new label if raw part and none found, otherwise err.
754  */
755 int
756 fdgetdisklabel(struct fd_softc *sc, dev_t dev)
757 {
758 	struct disklabel *lp, *dlp;
759 	struct cpu_disklabel *clp;
760 	struct buf *bp;
761 	int error, part;
762 
763 	if (sc->flags & FDF_HAVELABEL &&
764 	    sc->dkdev.dk_label->d_npartitions == (FDPART(dev) + 1))
765 		return(0);
766 #ifdef FDDEBUG
767 	printf("fdgetdisklabel()\n");
768 #endif
769 	part = FDPART(dev);
770 	lp = sc->dkdev.dk_label;
771 	clp =  sc->dkdev.dk_cpulabel;
772 	bzero(lp, sizeof(struct disklabel));
773 	bzero(clp, sizeof(struct cpu_disklabel));
774 
775 	lp->d_secsize = FDSECSIZE;
776 	lp->d_ntracks = FDNHEADS;
777 	lp->d_ncylinders = sc->type->ncylinders;
778 	lp->d_nsectors = sc->nsectors;
779 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
780 	lp->d_secperunit = lp->d_secpercyl * lp->d_ncylinders;
781 	lp->d_npartitions = part + 1;
782 	lp->d_partitions[part].p_size = lp->d_secperunit;
783 	lp->d_partitions[part].p_fstype = FS_UNUSED;
784 	lp->d_partitions[part].p_fsize = 1024;
785 	lp->d_partitions[part].p_frag = 8;
786 	lp->d_partitions[part].p_cpg = 2;	/* for adosfs: reserved blks */
787 
788 	sc->flags |= FDF_HAVELABEL;
789 
790 	bp = (void *)geteblk((int)lp->d_secsize);
791 	bp->b_dev = dev;
792 	bp->b_blkno = 0;
793 	bp->b_cylinder = 0;
794 	bp->b_bcount = FDSECSIZE;
795 	bp->b_flags |= B_READ;
796 	fdstrategy(bp);
797 	if ((error = biowait(bp)) != 0)
798 		goto nolabel;
799 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
800 	if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC ||
801 	    dkcksum(dlp)) {
802 		error = EINVAL;
803 		goto nolabel;
804 	}
805 	bcopy(dlp, lp, sizeof(struct disklabel));
806 	if (lp->d_trkseek > FDSTEPDELAY)
807 		sc->stepdelay = lp->d_trkseek;
808 	brelse(bp);
809 	return(0);
810 nolabel:
811 	fdgetdefaultlabel(sc, lp, part);
812 	brelse(bp);
813 	return(0);
814 }
815 
816 /*
817  * set the incore copy of this units disklabel
818  */
819 int
820 fdsetdisklabel(struct fd_softc *sc, struct disklabel *lp)
821 {
822 	struct disklabel *clp;
823 	struct partition *pp;
824 
825 	/*
826 	 * must have at least opened raw unit to fetch the
827 	 * raw_part stuff.
828 	 */
829 	if ((sc->flags & FDF_HAVELABEL) == 0)
830 		return(EINVAL);
831 	clp = sc->dkdev.dk_label;
832 	/*
833 	 * make sure things check out and we only have one valid
834 	 * partition
835 	 */
836 #ifdef FDDEBUG
837 	printf("fdsetdisklabel\n");
838 #endif
839 	if (lp->d_secsize != FDSECSIZE ||
840 	    lp->d_nsectors != clp->d_nsectors ||
841 	    lp->d_ntracks != FDNHEADS ||
842 	    lp->d_ncylinders != clp->d_ncylinders ||
843 	    lp->d_secpercyl != clp->d_secpercyl ||
844 	    lp->d_secperunit != clp->d_secperunit ||
845 	    lp->d_magic != DISKMAGIC ||
846 	    lp->d_magic2 != DISKMAGIC ||
847 	    lp->d_npartitions == 0 ||
848 	    lp->d_npartitions > FDMAXPARTS ||
849 	    (lp->d_partitions[0].p_offset && lp->d_partitions[1].p_offset) ||
850 	    dkcksum(lp))
851 		return(EINVAL);
852 	/*
853 	 * if any partitions are present make sure they
854 	 * represent the currently open type
855 	 */
856 	if ((pp = &lp->d_partitions[0])->p_size) {
857 		if ((pp = &lp->d_partitions[1])->p_size == 0)
858 			goto done;
859 		else if (sc->openpart != 1)
860 			return(EINVAL);
861 	} else if (sc->openpart != 0)
862 		return(EINVAL);
863 	/*
864 	 * make sure selected partition is within bounds
865 	 * XXX on the second check, its to handle a bug in
866 	 * XXX the cluster routines as they require mutliples
867 	 * XXX of NBPG currently
868 	 */
869 	if ((pp->p_offset + pp->p_size >= lp->d_secperunit) ||
870 	    (pp->p_frag * pp->p_fsize % NBPG))
871 		return(EINVAL);
872 done:
873 	bcopy(lp, clp, sizeof(struct disklabel));
874 	return(0);
875 }
876 
877 /*
878  * write out the incore copy of this units disklabel
879  */
880 int
881 fdputdisklabel(struct fd_softc *sc, dev_t dev)
882 {
883 	struct disklabel *lp, *dlp;
884 	struct buf *bp;
885 	int error;
886 
887 	if ((sc->flags & FDF_HAVELABEL) == 0)
888 		return(EBADF);
889 #ifdef FDDEBUG
890 	printf("fdputdisklabel\n");
891 #endif
892 	/*
893 	 * get buf and read in sector 0
894 	 */
895 	lp = sc->dkdev.dk_label;
896 	bp = geteblk((int)lp->d_secsize);
897 	bp->b_dev = FDMAKEDEV(major(dev), FDUNIT(dev), RAW_PART);
898 	bp->b_blkno = 0;
899 	bp->b_cylinder = 0;
900 	bp->b_bcount = FDSECSIZE;
901 	bp->b_flags |= B_READ;
902 	fdstrategy(bp);
903 	if ((error = biowait(bp)) != 0)
904 		goto done;
905 	/*
906 	 * copy disklabel to buf and write it out syncronous
907 	 */
908 	dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
909 	bcopy(lp, dlp, sizeof(struct disklabel));
910 	bp->b_blkno = 0;
911 	bp->b_cylinder = 0;
912 	bp->b_flags &= ~(B_READ|B_DONE);
913 	bp->b_flags |= B_WRITE;
914 	fdstrategy(bp);
915 	error = biowait(bp);
916 done:
917 	brelse(bp);
918 	return(error);
919 }
920 
921 /*
922  * figure out drive type or NULL if none.
923  */
924 struct fdtype *
925 fdcgetfdtype(int unit)
926 {
927 	struct fdtype *ftp;
928 	u_long id, idb;
929 	int cnt, umask;
930 
931 	id = 0;
932 	umask = 1 << (3 + unit);
933 
934 	FDDESELECT(FDCUNITMASK);
935 
936 	FDSETMOTOR(1);
937 	delay(1);
938 	FDSELECT(umask);
939 	delay(1);
940 	FDDESELECT(umask);
941 
942 	FDSETMOTOR(0);
943 	delay(1);
944 	FDSELECT(umask);
945 	delay(1);
946 	FDDESELECT(umask);
947 
948 	for (idb = 0x80000000; idb; idb >>= 1) {
949 		FDSELECT(umask);
950 		delay(1);
951 		if (FDTESTC(FDB_READY) == 0)
952 			id |= idb;
953 		FDDESELECT(umask);
954 		delay(1);
955 	}
956 #ifdef FDDEBUG
957 	printf("fdcgettype unit %d id 0x%lx\n", unit, id);
958 #endif
959 
960 	for (cnt = 0, ftp = fdtype; cnt < nfdtype; ftp++, cnt++)
961 		if (ftp->driveid == id)
962 			return(ftp);
963 	/*
964 	 * 3.5dd's at unit 0 do not always return id.
965 	 */
966 	if (unit == 0)
967 		return(fdtype);
968 	return(NULL);
969 }
970 
971 /*
972  * turn motor off if possible otherwise mark as needed and will be done
973  * later.
974  */
975 void
976 fdmotoroff(void *arg)
977 {
978 	struct fd_softc *sc;
979 	int s;
980 
981 	sc = arg;
982 	s = splbio();
983 
984 #ifdef FDDEBUG
985 	printf("fdmotoroff: unit %d\n", sc->hwunit);
986 #endif
987 	if ((sc->flags & FDF_MOTORON) == 0)
988 		goto done;
989 	/*
990 	 * if we have a timeout on a dma operation let fddmadone()
991 	 * deal with it.
992 	 */
993 	if (fdc_indma == sc) {
994 		fddmadone(sc, 1);
995 		goto done;
996 	}
997 #ifdef FDDEBUG
998 	printf(" motor was on, turning off\n");
999 #endif
1000 
1001 	/*
1002 	 * flush cache if needed
1003 	 */
1004 	if (sc->flags & FDF_DIRTY) {
1005 		sc->flags |= FDF_JUSTFLUSH | FDF_MOTOROFF;
1006 #ifdef FDDEBUG
1007 		printf("  flushing dirty buffer first\n");
1008 #endif
1009 		/*
1010 		 * if dma'ing done for now, fddone() will call us again
1011 		 */
1012 		if (fdc_indma)
1013 			goto done;
1014 		fddmastart(sc, sc->cachetrk);
1015 		goto done;
1016 	}
1017 
1018 	/*
1019 	 * if controller is busy just schedule us to be called back
1020 	 */
1021 	if (fdc_indma) {
1022 		/*
1023 		 * someone else has the controller now
1024 		 * just set flag and let fddone() call us again.
1025 		 */
1026 		sc->flags |= FDF_MOTOROFF;
1027 		goto done;
1028 	}
1029 
1030 #ifdef FDDEBUG
1031 	printf("  hw turning unit off\n");
1032 #endif
1033 
1034 	sc->flags &= ~(FDF_MOTORON | FDF_MOTOROFF);
1035 	FDDESELECT(FDCUNITMASK);
1036 	FDSETMOTOR(0);
1037 	delay(1);
1038 	FDSELECT(sc->unitmask);
1039 	delay(4);
1040 	FDDESELECT(sc->unitmask);
1041 	delay(1);
1042 	if (sc->flags & FDF_WMOTOROFF)
1043 		wakeup(fdmotoroff);
1044 done:
1045 	splx(s);
1046 }
1047 
1048 /*
1049  * select drive seek to track exit with motor on.
1050  * fdsetpos(x, 0, 0) does calibrates the drive.
1051  */
1052 void
1053 fdsetpos(struct fd_softc *sc, int trk, int towrite)
1054 {
1055 	int nstep, sdir, ondly, ncyl, nside;
1056 
1057 	FDDESELECT(FDCUNITMASK);
1058 	FDSETMOTOR(1);
1059 	delay(1);
1060 	FDSELECT(sc->unitmask);
1061 	delay(1);
1062 	if ((sc->flags & FDF_MOTORON) == 0) {
1063 		ondly = 0;
1064 		while (FDTESTC(FDB_READY) == 0) {
1065 			delay(1000);
1066 			if (++ondly >= 1000)
1067 				break;
1068 		}
1069 	}
1070 	sc->flags |= FDF_MOTORON;
1071 
1072 	ncyl = trk / FDNHEADS;
1073 	nside = trk % FDNHEADS;
1074 
1075 	if (sc->curcyl == ncyl && fdc_side == nside)
1076 		return;
1077 
1078 	if (towrite)
1079 		sc->flags |= FDF_WRITEWAIT;
1080 
1081 #ifdef FDDEBUG
1082 	printf("fdsetpos: cyl %d head %d towrite %d\n", trk / FDNHEADS,
1083 	    trk % FDNHEADS, towrite);
1084 #endif
1085 	nstep = ncyl - sc->curcyl;
1086 	if (nstep) {
1087 		/*
1088 		 * figure direction
1089 		 */
1090 		if (nstep > 0 && ncyl != 0) {
1091 			sdir = FDSTEPIN;
1092 			FDSETDIR(1);
1093 		} else {
1094 			nstep = -nstep;
1095 			sdir = FDSTEPOUT;
1096 			FDSETDIR(0);
1097 		}
1098 		if (ncyl == 0) {
1099 			/*
1100 			 * either just want cylinder 0 or doing
1101 			 * a calibrate.
1102 			 */
1103 			nstep = 256;
1104 			while (FDTESTC(FDB_CYLZERO) == 0 && nstep--) {
1105 				FDSTEP;
1106 				delay(sc->stepdelay);
1107 			}
1108 			if (nstep < 0)
1109 				sc->flags |= FDF_NOTRACK0;
1110 		} else {
1111 			/*
1112 			 * step the needed amount amount.
1113 			 */
1114 			while (nstep--) {
1115 				FDSTEP;
1116 				delay(sc->stepdelay);
1117 			}
1118 		}
1119 		/*
1120 		 * if switched directions
1121 		 * allow drive to settle.
1122 		 */
1123 		if (sc->pstepdir != sdir)
1124 			delay(FDSETTLEDELAY);
1125 		sc->pstepdir = sdir;
1126 		sc->curcyl = ncyl;
1127 	}
1128 	if (nside == fdc_side)
1129 		return;
1130 	/*
1131 	 * select side
1132 	 */
1133 	fdc_side = nside;
1134 	FDSETHEAD(nside);
1135 	delay(FDPRESIDEDELAY);
1136 }
1137 
1138 void
1139 fdselunit(struct fd_softc *sc)
1140 {
1141 	FDDESELECT(FDCUNITMASK);		/* deselect all */
1142 	FDSETMOTOR(sc->flags & FDF_MOTORON);	/* set motor to unit's state */
1143 	delay(1);
1144 	FDSELECT(sc->unitmask);			/* select unit */
1145 	delay(1);
1146 }
1147 
1148 /*
1149  * process next buf on device queue.
1150  * normall sequence of events:
1151  * fdstart() -> fddmastart();
1152  * fdidxintr();
1153  * fdintr() -> fddmadone() -> fddone();
1154  * if the track is in the cache then fdstart() will short-circuit
1155  * to fddone() else if the track cache is dirty it will flush.  If
1156  * the buf is not an entire track it will cache the requested track.
1157  */
1158 void
1159 fdstart(struct fd_softc *sc)
1160 {
1161 	int trk, error, write;
1162 	struct buf *bp, *dp;
1163 	int changed;
1164 
1165 #ifdef FDDEBUG
1166 	printf("fdstart: unit %d\n", sc->hwunit);
1167 #endif
1168 
1169 	/*
1170 	 * if dma'ing just return. we must have been called from fdstartegy.
1171 	 */
1172 	if (fdc_indma)
1173 		return;
1174 
1175 	/*
1176 	 * get next buf if there.
1177 	 */
1178 	dp = &sc->curbuf;
1179 	if ((bp = BUFQ_FIRST(&sc->bufq)) == NULL) {
1180 #ifdef FDDEBUG
1181 		printf("  nothing to do\n");
1182 #endif
1183 		return;
1184 	}
1185 
1186 	/*
1187 	 * Mark us as busy now, in case fddone() gets called in one
1188 	 * of the cases below.
1189 	 */
1190 	disk_busy(&sc->dkdev);
1191 
1192 	/*
1193 	 * make sure same disk is loaded
1194 	 */
1195 	fdselunit(sc);
1196 	changed = FDTESTC(FDB_CHANGED);
1197 	FDDESELECT(sc->unitmask);
1198 	if (changed) {
1199 		/*
1200 		 * disk missing, invalidate all future io on
1201 		 * this unit until re-open()'ed also invalidate
1202 		 * all current io
1203 		 */
1204 printf("fdstart: disk changed\n");
1205 #ifdef FDDEBUG
1206 		printf("  disk was removed invalidating all io\n");
1207 #endif
1208 		sc->flags &= ~FDF_HAVELABEL;
1209 		for (;;) {
1210 			bp->b_flags |= B_ERROR;
1211 			bp->b_error = EIO;
1212 			if (BUFQ_NEXT(bp) == NULL)
1213 				break;
1214 			biodone(bp);
1215 			bp = BUFQ_NEXT(bp);
1216 		}
1217 		/*
1218 		 * do fddone() on last buf to allow other units to start.
1219 		 */
1220 		BUFQ_INSERT_HEAD(&sc->bufq, bp);
1221 		fddone(sc);
1222 		return;
1223 	}
1224 
1225 	/*
1226 	 * we have a valid buf, setup our local version
1227 	 * we use this count to allow reading over multiple tracks.
1228 	 * into a single buffer
1229 	 */
1230 	dp->b_bcount = bp->b_bcount;
1231 	dp->b_blkno = bp->b_blkno;
1232 	dp->b_data = bp->b_data;
1233 	dp->b_flags = bp->b_flags;
1234 	dp->b_resid = 0;
1235 
1236 	if (bp->b_flags & B_READ)
1237 		write = 0;
1238 	else if (FDTESTC(FDB_PROTECT) == 0)
1239 		write = 1;
1240 	else {
1241 		error = EPERM;
1242 		goto bad;
1243 	}
1244 
1245 	/*
1246 	 * figure trk given blkno
1247 	 */
1248 	trk = bp->b_blkno / sc->nsectors;
1249 
1250 	/*
1251 	 * check to see if same as currently cached track
1252 	 * if so we need to do no dma read.
1253 	 */
1254 	if (trk == sc->cachetrk) {
1255 		fddone(sc);
1256 		return;
1257 	}
1258 
1259 	/*
1260 	 * if we will be overwriting the entire cache, don't bother to
1261 	 * fetch it.
1262 	 */
1263 	if (bp->b_bcount == (sc->nsectors * FDSECSIZE) && write &&
1264 	    bp->b_blkno % sc->nsectors == 0) {
1265 		if (sc->flags & FDF_DIRTY)
1266 			sc->flags |= FDF_JUSTFLUSH;
1267 		else {
1268 			sc->cachetrk = trk;
1269 			fddone(sc);
1270 			return;
1271 		}
1272 	}
1273 
1274 	/*
1275 	 * start dma read of `trk'
1276 	 */
1277 	fddmastart(sc, trk);
1278 	return;
1279 bad:
1280 	bp->b_flags |= B_ERROR;
1281 	bp->b_error = error;
1282 	fddone(sc);
1283 }
1284 
1285 /*
1286  * continue a started operation on next track. always begin at
1287  * sector 0 on the next track.
1288  */
1289 void
1290 fdcont(struct fd_softc *sc)
1291 {
1292 	struct buf *dp, *bp;
1293 	int trk, write;
1294 
1295 	dp = &sc->curbuf;
1296 	bp = BUFQ_FIRST(&sc->bufq);
1297 	dp->b_data += (dp->b_bcount - bp->b_resid);
1298 	dp->b_blkno += (dp->b_bcount - bp->b_resid) / FDSECSIZE;
1299 	dp->b_bcount = bp->b_resid;
1300 
1301 	/*
1302 	 * figure trk given blkno
1303 	 */
1304 	trk = dp->b_blkno / sc->nsectors;
1305 #ifdef DEBUG
1306 	if (trk != sc->cachetrk + 1 || dp->b_blkno % sc->nsectors != 0)
1307 		panic("fdcont: confused");
1308 #endif
1309 	if (dp->b_flags & B_READ)
1310 		write = 0;
1311 	else
1312 		write = 1;
1313 	/*
1314 	 * if we will be overwriting the entire cache, don't bother to
1315 	 * fetch it.
1316 	 */
1317 	if (dp->b_bcount == (sc->nsectors * FDSECSIZE) && write) {
1318 		if (sc->flags & FDF_DIRTY)
1319 			sc->flags |= FDF_JUSTFLUSH;
1320 		else {
1321 			sc->cachetrk = trk;
1322 			fddone(sc);
1323 			return;
1324 		}
1325 	}
1326 	/*
1327 	 * start dma read of `trk'
1328 	 */
1329 	fddmastart(sc, trk);
1330 	return;
1331 }
1332 
1333 void
1334 fddmastart(struct fd_softc *sc, int trk)
1335 {
1336 	int adkmask, ndmaw, write, dmatrk;
1337 
1338 #ifdef FDDEBUG
1339 	printf("fddmastart: unit %d cyl %d head %d", sc->hwunit,
1340 	    trk / FDNHEADS, trk % FDNHEADS);
1341 #endif
1342 	/*
1343 	 * flush the cached track if dirty else read requested track.
1344 	 */
1345 	if (sc->flags & FDF_DIRTY) {
1346 		fdcachetoraw(sc);
1347 		ndmaw = sc->type->nwritew;
1348 		dmatrk = sc->cachetrk;
1349 		write = 1;
1350 	} else {
1351 		ndmaw = sc->type->nreadw;
1352 		dmatrk = trk;
1353 		write = 0;
1354 	}
1355 
1356 #ifdef FDDEBUG
1357 	printf(" %s", write ? " flushing cache\n" : " loading cache\n");
1358 #endif
1359 	sc->cachetrk = trk;
1360 	fdc_indma = sc;
1361 	fdsetpos(sc, dmatrk, write);
1362 
1363 	/*
1364 	 * setup dma stuff
1365 	 */
1366 	if (write == 0) {
1367 		custom.adkcon = ADKF_MSBSYNC;
1368 		custom.adkcon = ADKF_SETCLR | ADKF_WORDSYNC | ADKF_FAST;
1369 		custom.dsksync = FDMFMSYNC;
1370 	} else {
1371 		custom.adkcon = ADKF_PRECOMP1 | ADKF_PRECOMP0 | ADKF_WORDSYNC |
1372 		    ADKF_MSBSYNC;
1373 		adkmask = ADKF_SETCLR | ADKF_FAST | ADKF_MFMPREC;
1374 		if (dmatrk >= sc->type->precomp[0])
1375 			adkmask |= ADKF_PRECOMP0;
1376 		if (dmatrk >= sc->type->precomp[1])
1377 			adkmask |= ADKF_PRECOMP1;
1378 		custom.adkcon = adkmask;
1379 	}
1380 	custom.dskpt = (u_char *)kvtop(fdc_dmap);
1381 
1382 	/*
1383 	 * If writing an MSDOS track, activate disk index pulse
1384 	 * interrupt, dma will be started in the intr routine fdidxintr()
1385 	 * Otherwise, start the DMA here.
1386 	 */
1387 	if (write && sc->openpart == FDMSDOSPART) {
1388 		fdc_dmalen = ndmaw;
1389 		fdc_dmawrite = write;
1390 		ciab.icr = CIA_ICR_IR_SC | CIA_ICR_FLG;
1391 	} else {
1392 		FDDMASTART(ndmaw, write);
1393 		fdc_dmalen = 0;
1394 	}
1395 
1396 #ifdef FDDEBUG
1397 	printf("  dma started\n");
1398 #endif
1399 }
1400 
1401 /*
1402  * recalibrate the drive
1403  */
1404 void
1405 fdcalibrate(void *arg)
1406 {
1407 	struct fd_softc *sc;
1408 	static int loopcnt;
1409 
1410 	sc = arg;
1411 
1412 	if (loopcnt == 0) {
1413 		/*
1414 		 * seek cyl 0
1415 		 */
1416 		fdc_indma = sc;
1417 		sc->stepdelay += 900;
1418 		if (sc->cachetrk > 1)
1419 			fdsetpos(sc, sc->cachetrk % FDNHEADS, 0);
1420 		sc->stepdelay -= 900;
1421 	}
1422 	if (loopcnt++ & 1)
1423 		fdsetpos(sc, sc->cachetrk, 0);
1424 	else
1425 		fdsetpos(sc, sc->cachetrk + FDNHEADS, 0);
1426 	/*
1427 	 * trk++, trk, trk++, trk, trk++, trk, trk++, trk and dma
1428 	 */
1429 	if (loopcnt < 8)
1430 		callout_reset(&sc->calibrate_ch, hz / 8, fdcalibrate, sc);
1431 	else {
1432 		loopcnt = 0;
1433 		fdc_indma = NULL;
1434 		callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1435 		fddmastart(sc, sc->cachetrk);
1436 	}
1437 }
1438 
1439 void
1440 fddmadone(struct fd_softc *sc, int timeo)
1441 {
1442 #ifdef FDDEBUG
1443 	printf("fddmadone: unit %d, timeo %d\n", sc->hwunit, timeo);
1444 #endif
1445 	fdc_indma = NULL;
1446 	callout_stop(&sc->motor_ch);
1447 	FDDMASTOP;
1448 
1449 	/*
1450 	 * guarantee the drive has been at current head and cyl
1451 	 * for at least FDWRITEDELAY after a write.
1452 	 */
1453 	if (sc->flags & FDF_WRITEWAIT) {
1454 		delay(FDWRITEDELAY);
1455 		sc->flags &= ~FDF_WRITEWAIT;
1456 	}
1457 
1458 	if ((sc->flags & FDF_MOTOROFF) == 0) {
1459 		/*
1460 		 * motor runs for 1.5 seconds after last dma
1461 		 */
1462 		callout_reset(&sc->motor_ch, 3 * hz / 2, fdmotoroff, sc);
1463 	}
1464 	if (sc->flags & FDF_DIRTY) {
1465 		/*
1466 		 * if buffer dirty, the last dma cleaned it
1467 		 */
1468 		sc->flags &= ~FDF_DIRTY;
1469 		if (timeo)
1470 			printf("%s: write of track cache timed out.\n",
1471 			    sc->sc_dv.dv_xname);
1472 		if (sc->flags & FDF_JUSTFLUSH) {
1473 			sc->flags &= ~FDF_JUSTFLUSH;
1474 			/*
1475 			 * we are done dma'ing
1476 			 */
1477 			fddone(sc);
1478 			return;
1479 		}
1480 		/*
1481 		 * load the cache
1482 		 */
1483 		fddmastart(sc, sc->cachetrk);
1484 		return;
1485 	}
1486 #ifdef FDDEBUG
1487 	else if (sc->flags & FDF_MOTOROFF)
1488 		panic("fddmadone: FDF_MOTOROFF with no FDF_DIRTY");
1489 #endif
1490 
1491 	/*
1492 	 * cache loaded decode it into cache buffer
1493 	 */
1494 	if (timeo == 0 && fdrawtocache(sc) == 0)
1495 		sc->retried = 0;
1496 	else {
1497 #ifdef FDDEBUG
1498 		if (timeo)
1499 			printf("%s: fddmadone: cache load timed out.\n",
1500 			    sc->sc_dv.dv_xname);
1501 #endif
1502 		if (sc->retried >= sc->retries) {
1503 			sc->retried = 0;
1504 			sc->cachetrk = -1;
1505 		} else {
1506 			sc->retried++;
1507 			/*
1508 			 * this will be restarted at end of calibrate loop.
1509 			 */
1510 			callout_stop(&sc->motor_ch);
1511 			fdcalibrate(sc);
1512 			return;
1513 		}
1514 	}
1515 	fddone(sc);
1516 }
1517 
1518 void
1519 fddone(struct fd_softc *sc)
1520 {
1521 	struct buf *dp, *bp;
1522 	char *data;
1523 	int sz;
1524 
1525 #ifdef FDDEBUG
1526 	printf("fddone: unit %d\n", sc->hwunit);
1527 #endif
1528 	/*
1529 	 * check to see if unit is just flushing the cache,
1530 	 * that is we have no io queued.
1531 	 */
1532 	if (sc->flags & FDF_MOTOROFF)
1533 		goto nobuf;
1534 
1535 	dp = &sc->curbuf;
1536 	if ((bp = BUFQ_FIRST(&sc->bufq)) == NULL)
1537 		panic ("fddone");
1538 	/*
1539 	 * check for an error that may have occurred
1540 	 * while getting the track.
1541 	 */
1542 	if (sc->cachetrk == -1) {
1543 		sc->retried = 0;
1544 		bp->b_flags |= B_ERROR;
1545 		bp->b_error = EIO;
1546 	} else if ((bp->b_flags & B_ERROR) == 0) {
1547 		data = sc->cachep;
1548 		/*
1549 		 * get offset of data in track cache and limit
1550 		 * the copy size to not exceed the cache's end.
1551 		 */
1552 		data += (dp->b_blkno % sc->nsectors) * FDSECSIZE;
1553 		sz = sc->nsectors - dp->b_blkno % sc->nsectors;
1554 		sz *= FDSECSIZE;
1555 		sz = min(dp->b_bcount, sz);
1556 		if (bp->b_flags & B_READ)
1557 			bcopy(data, dp->b_data, sz);
1558 		else {
1559 			bcopy(dp->b_data, data, sz);
1560 			sc->flags |= FDF_DIRTY;
1561 		}
1562 		bp->b_resid = dp->b_bcount - sz;
1563 		if (bp->b_resid == 0) {
1564 			bp->b_error = 0;
1565 		} else {
1566 			/*
1567 			 * not done yet need to read next track
1568 			 */
1569 			fdcont(sc);
1570 			return;
1571 		}
1572 	}
1573 	/*
1574 	 * remove from queue.
1575 	 */
1576 	BUFQ_REMOVE(&sc->bufq, bp);
1577 
1578 	disk_unbusy(&sc->dkdev, (bp->b_bcount - bp->b_resid));
1579 
1580 	biodone(bp);
1581 nobuf:
1582 	fdfindwork(sc->sc_dv.dv_unit);
1583 }
1584 
1585 void
1586 fdfindwork(int unit)
1587 {
1588 	struct fd_softc *ssc, *sc;
1589 	int i, last;
1590 
1591 	/*
1592 	 * first see if we have any fdopen()'s waiting
1593 	 */
1594 	if (fdc_wantwakeup) {
1595 		wakeup(fdopen);
1596 		fdc_wantwakeup--;
1597 		return;
1598 	}
1599 
1600 	/*
1601 	 * start next available unit, linear search from the next unit
1602 	 * wrapping and finally this unit.
1603 	 */
1604 	last = 0;
1605 	ssc = NULL;
1606 	for (i = unit + 1; last == 0; i++) {
1607 		if (i == unit)
1608 			last = 1;
1609 		if (i >= fd_cd.cd_ndevs) {
1610 			i = -1;
1611 			continue;
1612 		}
1613 		if ((sc = fd_cd.cd_devs[i]) == NULL)
1614 			continue;
1615 
1616 		/*
1617 		 * if unit has requested to be turned off
1618 		 * and it has no buf's queued do it now
1619 		 */
1620 		if (sc->flags & FDF_MOTOROFF) {
1621 			if (BUFQ_FIRST(&sc->bufq) == NULL)
1622 				fdmotoroff(sc);
1623 			else {
1624 				/*
1625 				 * we gained a buf request while
1626 				 * we waited, forget the motoroff
1627 				 */
1628 				sc->flags &= ~FDF_MOTOROFF;
1629 			}
1630 			/*
1631 			 * if we now have dma unit must have needed
1632 			 * flushing, quit
1633 			 */
1634 			if (fdc_indma)
1635 				return;
1636 		}
1637 		/*
1638 		 * if we have no start unit and the current unit has
1639 		 * io waiting choose this unit to start.
1640 		 */
1641 		if (ssc == NULL && BUFQ_FIRST(&sc->bufq) != NULL)
1642 			ssc = sc;
1643 	}
1644 	if (ssc)
1645 		fdstart(ssc);
1646 }
1647 
1648 /*
1649  * min byte count to whats left of the track in question
1650  */
1651 void
1652 fdminphys(struct buf *bp)
1653 {
1654 	struct fd_softc *sc;
1655 	int trk, sec, toff, tsz;
1656 
1657 	if ((sc = getsoftc(fd_cd, FDUNIT(bp->b_dev))) == NULL)
1658 		panic("fdminphys: couldn't get softc");
1659 
1660 	trk = bp->b_blkno / sc->nsectors;
1661 	sec = bp->b_blkno % sc->nsectors;
1662 
1663 	toff = sec * FDSECSIZE;
1664 	tsz = sc->nsectors * FDSECSIZE;
1665 #ifdef FDDEBUG
1666 	printf("fdminphys: before %d", bp->b_bcount);
1667 #endif
1668 	bp->b_bcount = min(bp->b_bcount, tsz - toff);
1669 #ifdef FDDEBUG
1670 	printf(" after %d\n", bp->b_bcount);
1671 #endif
1672 	minphys(bp);
1673 }
1674 
1675 /*
1676  * encode the track cache into raw MFM ready for dma
1677  * when we go to multiple disk formats, this will call type dependent
1678  * functions
1679  */
1680 void fdcachetoraw(struct fd_softc *sc)
1681 {
1682 	if (sc->openpart == FDMSDOSPART)
1683 		mscachetoraw(sc);
1684 	else
1685 		amcachetoraw(sc);
1686 }
1687 
1688 /*
1689  * decode raw MFM from dma into units track cache.
1690  * when we go to multiple disk formats, this will call type dependent
1691  * functions
1692  */
1693 int
1694 fdrawtocache(struct fd_softc *sc)
1695 {
1696 
1697 	if (sc->openpart == FDMSDOSPART)
1698 		return(msrawtocache(sc));
1699 	else
1700 		return(amrawtocache(sc));
1701 }
1702 
1703 void
1704 amcachetoraw(struct fd_softc *sc)
1705 {
1706 	static u_long mfmnull[4];
1707 	u_long *rp, *crp, *dp, hcksum, dcksum, info, zero;
1708 	int sec, i;
1709 
1710 	rp = fdc_dmap;
1711 
1712 	/*
1713 	 * not yet one sector (- 1 long) gap.
1714 	 * for now use previous drivers values
1715 	 */
1716 	for (i = 0; i < sc->type->gap; i++)
1717 		*rp++ = 0xaaaaaaaa;
1718 	/*
1719 	 * process sectors
1720 	 */
1721 	dp = sc->cachep;
1722 	zero = 0;
1723 	info = 0xff000000 | (sc->cachetrk << 16) | sc->nsectors;
1724 	for (sec = 0; sec < sc->nsectors; sec++, info += (1 << 8) - 1) {
1725 		hcksum = dcksum = 0;
1726 		/*
1727 		 * sector format
1728 		 *	offset		description
1729 		 *-----------------------------------
1730 		 *  0			null
1731 		 *  1			sync
1732 		 * oddbits	evenbits
1733 		 *----------------------
1734 		 *  2		3	[0xff]b [trk]b [sec]b [togap]b
1735 		 *  4-7		8-11	null
1736 		 * 12		13	header cksum [2-11]
1737 		 * 14		15	data cksum [16-271]
1738 		 * 16-143	144-271	data
1739 		 */
1740 		*rp = 0xaaaaaaaa;
1741 		if (*(rp - 1) & 0x1)
1742 			*rp &= 0x7fffffff;	/* clock bit correction */
1743 		rp++;
1744 		*rp++ = (FDMFMSYNC << 16) | FDMFMSYNC;
1745 		rp = mfmblkencode(&info, rp, &hcksum, 1);
1746 		rp = mfmblkencode(mfmnull, rp, &hcksum, 4);
1747 		rp = mfmblkencode(&hcksum, rp, NULL, 1);
1748 
1749 		crp = rp;
1750 		rp = mfmblkencode(dp, rp + 2, &dcksum, FDSECLWORDS);
1751 		dp += FDSECLWORDS;
1752 		crp = mfmblkencode(&dcksum, crp, NULL, 1);
1753 		if (*(crp - 1) & 0x1)
1754 			*crp &= 0x7fffffff;	/* clock bit correction */
1755 		else if ((*crp & 0x40000000) == 0)
1756 			*crp |= 0x80000000;
1757 	}
1758 	*rp = 0xaaa80000;
1759 	if (*(rp - 1) & 0x1)
1760 		*rp &= 0x7fffffff;
1761 }
1762 
1763 u_long *
1764 fdfindsync(u_long *rp, u_long *ep)
1765 {
1766 	u_short *sp;
1767 
1768 	sp = (u_short *)rp;
1769 	while ((u_long *)sp < ep && *sp != FDMFMSYNC)
1770 		sp++;
1771 	while ((u_long *)sp < ep && *sp == FDMFMSYNC)
1772 		sp++;
1773 	if ((u_long *)sp < ep)
1774 		return((u_long *)sp);
1775 	return(NULL);
1776 }
1777 
1778 int
1779 amrawtocache(struct fd_softc *sc)
1780 {
1781 	u_long mfmnull[4];
1782 	u_long *dp, *rp, *erp, *crp, *srp, hcksum, dcksum, info, cktmp;
1783 	int cnt, doagain;
1784 
1785 	doagain = 1;
1786 	srp = rp = fdc_dmap;
1787 	erp = (u_long *)((u_short *)rp + sc->type->nreadw);
1788 	cnt = 0;
1789 again:
1790 	if (doagain == 0 || (rp = srp = fdfindsync(srp, erp)) == NULL) {
1791 #ifdef DIAGNOSTIC
1792 		printf("%s: corrupted track (%d) data.\n",
1793 		    sc->sc_dv.dv_xname, sc->cachetrk);
1794 #endif
1795 		return(-1);
1796 	}
1797 
1798 	/*
1799 	 * process sectors
1800 	 */
1801 	for (; cnt < sc->nsectors; cnt++) {
1802 		hcksum = dcksum = 0;
1803 		rp = mfmblkdecode(rp, &info, &hcksum, 1);
1804 		rp = mfmblkdecode(rp, mfmnull, &hcksum, 4);
1805 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1806 		if (cktmp != hcksum) {
1807 #ifdef FDDEBUG
1808 			printf("  info 0x%x hchksum 0x%x trkhcksum 0x%x\n",
1809 			    info, hcksum, cktmp);
1810 #endif
1811 			goto again;
1812 		}
1813 		if (((info >> 16) & 0xff) != sc->cachetrk) {
1814 #ifdef DEBUG
1815 			printf("%s: incorrect track found: 0x%lx %d\n",
1816 			    sc->sc_dv.dv_xname, info, sc->cachetrk);
1817 #endif
1818 			goto again;
1819 		}
1820 #ifdef FDDEBUG
1821 		printf("  info 0x%x\n", info);
1822 #endif
1823 
1824 		rp = mfmblkdecode(rp, &cktmp, NULL, 1);
1825 		dp = sc->cachep;
1826 		dp += FDSECLWORDS * ((info >> 8) & 0xff);
1827 		crp = mfmblkdecode(rp, dp, &dcksum, FDSECLWORDS);
1828 		if (cktmp != dcksum) {
1829 #ifdef FDDEBUG
1830 			printf("  info 0x%x dchksum 0x%x trkdcksum 0x%x\n",
1831 			    info, dcksum, cktmp);
1832 #endif
1833 			goto again;
1834 		}
1835 
1836 		/*
1837 		 * if we are at gap then we can no longer be sure
1838 		 * of correct sync marks
1839 		 */
1840 		if ((info && 0xff) == 1)
1841 			doagain = 1;
1842 		else
1843 			doagain = 0;
1844 		srp = rp = fdfindsync(crp, erp);
1845 	}
1846 	return(0);
1847 }
1848 
1849 void
1850 mscachetoraw(struct fd_softc *sc)
1851 {
1852 	u_short *rp, *erp, crc;
1853 	u_char *cp, tb[5];
1854 	int sec, i;
1855 
1856 	rp = (u_short *)fdc_dmap;
1857 	erp = rp + sc->type->nwritew;
1858 	cp = sc->cachep;
1859 
1860 	/*
1861 	 * initial track filler  (828 * GAP1)
1862 	 */
1863 	for (i = 0; i < sc->type->gap; i++) {
1864 		*rp++ = FDMFMGAP1;
1865 		*rp++ = FDMFMGAP1;
1866 	}
1867 
1868 	for (sec = 0; sec < sc->nsectors; sec++) {
1869 
1870 		/*
1871 		 * leading sector gap
1872 		 * (12 * GAP2) + (3 * SYNC)
1873 		 */
1874 		for (i = 0; i < 12; i++)
1875 			*rp++ = FDMFMGAP2;
1876 		*rp++ = FDMFMSYNC;
1877 		*rp++ = FDMFMSYNC;
1878 		*rp++ = FDMFMSYNC;
1879 
1880 		/*
1881 		 * sector information
1882 		 * (ID) + track + side + sector + sector size + CRC16
1883 		 */
1884 		*rp++ = FDMFMID;
1885 		tb[0] = sc->cachetrk / FDNHEADS;
1886 		tb[1] = sc->cachetrk % FDNHEADS;
1887 		tb[2] = sec + 1;
1888 		i = sc->bytespersec;
1889 		tb[3] = i < 256 ? 0 : (i < 512 ? 1 : (i < 1024 ? 2 : 3));
1890 		rp = msblkencode(rp, tb, 4, &crc);
1891 		tb[0] = crc >> 8;
1892 		tb[1] = crc & 0xff;
1893 		tb[2] = 0x4e; /* GAP1 decoded */
1894 		rp = msblkencode(rp, tb, 3, 0);
1895 
1896 		/*
1897 		 * sector info/data gap
1898 		 * (22 * GAP1) + (12 * GAP2) + (3 * SYNC)
1899 		 */
1900 		for (i = 0; i < 21; i++)
1901 			*rp++ = FDMFMGAP1;
1902 		for (i = 0; i < 12; i++)
1903 			*rp++ = FDMFMGAP2;
1904 		*rp++ = FDMFMSYNC;
1905 		*rp++ = FDMFMSYNC;
1906 		*rp++ = FDMFMSYNC;
1907 
1908 		/*
1909 		 * sector data
1910 		 * (DATA) + ...data... + CRC16
1911 		 */
1912 		*rp++ = FDMFMDATA;
1913 		rp = msblkencode(rp, cp, sc->bytespersec, &crc);
1914 		cp += sc->bytespersec;
1915 		tb[0] = crc >> 8;
1916 		tb[1] = crc & 0xff;
1917 		tb[2] = 0x4e; /* GAP3 decoded */
1918 		rp = msblkencode(rp, tb, 3, 0);
1919 
1920 		/*
1921 		 * trailing sector gap
1922 		 * (80 * GAP3)
1923 		 */
1924 		for (i = 0; i < 79; i++)
1925 			*rp++ = FDMFMGAP3;
1926 	}
1927 
1928 	/*
1929 	 * fill rest of track with GAP3
1930 	 */
1931 	while (rp != erp)
1932 		*rp++ = FDMFMGAP3;
1933 
1934 }
1935 
1936 int
1937 msrawtocache(struct fd_softc *sc)
1938 {
1939 	u_short *rp, *srp, *erp;
1940 	u_char tb[5], *cp;
1941 	int ct, sec, retry;
1942 
1943 	srp = rp = (u_short *)fdc_dmap;
1944 	erp = rp + sc->type->nreadw;
1945 	cp = sc->cachep;
1946 
1947 	for (ct = 0; ct < sc->nsectors; ct++) {
1948 		retry = 1;
1949 		do {
1950 			/*
1951 			 * skip leading gap to sync
1952 			 */
1953 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL) {
1954 #ifdef DIAGNOSTIC
1955 				printf("%s: corrupted track (%d) data.\n",
1956 				sc->sc_dv.dv_xname, sc->cachetrk);
1957 #endif
1958 				return(-1);
1959 			}
1960 
1961 			/*
1962 			 * Grab sector info
1963 			 */
1964 			if (*rp++ != FDMFMID)
1965 				continue;
1966 			rp = msblkdecode(rp, tb, 4);
1967 #ifdef FDDEBUG
1968 			printf("sector id: sector %d, track %d, side %d,"
1969 			    "bps %d\n", tb[2], tb[0], tb[1], 128 << tb[3]);
1970 #endif
1971 			if ((tb[0] * FDNHEADS + tb[1]) != sc->cachetrk ||
1972 			    tb[2] > sc->nsectors)
1973 				continue;
1974 
1975 			sec = tb[2];
1976 			sc->bytespersec = 128 << tb[3];
1977 			rp += 2; /* skip CRC-16 */
1978 
1979 			/*
1980 			 * skip gap and read in data
1981 			 */
1982 			if ((rp = (u_short *)fdfindsync((u_long *)rp, (u_long *)erp)) == NULL)
1983 				return(-1);
1984 			if (*rp++ != FDMFMDATA)
1985 				continue;
1986 			rp = msblkdecode(rp, cp + ((sec-1) * sc->bytespersec),
1987 			    sc->bytespersec);
1988 			rp += 2; /* skip CRC-16 */
1989 
1990 			retry = 0;
1991 		} while (retry);
1992 	}
1993 	return(0);
1994 }
1995 
1996 /*
1997  * encode len longwords of `dp' data in amiga mfm block format (`rp')
1998  * this format specified that the odd bits are at current pos and even
1999  * bits at len + current pos
2000  */
2001 u_long *
2002 mfmblkencode(u_long *dp, u_long *rp, u_long *cp, int len)
2003 {
2004 	u_long *sdp, *edp, d, dtmp, correct;
2005 
2006 	sdp = dp;
2007 	edp = dp + len;
2008 
2009 	if (*(rp - 1) & 0x1)
2010 		correct = 1;
2011 	else
2012 		correct = 0;
2013 	/*
2014 	 * do odd bits
2015 	 */
2016 	while (dp < edp) {
2017 		d = (*dp >> 1) & 0x55555555;	/* remove clock bits */
2018 		dtmp = d ^ 0x55555555;
2019 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2020 		/*
2021 		 * correct upper clock bit if needed
2022 		 */
2023 		if (correct)
2024 			d &= 0x7fffffff;
2025 		if (d & 0x1)
2026 			correct = 1;
2027 		else
2028 			correct = 0;
2029 		/*
2030 		 * do checksums and store in raw buffer
2031 		 */
2032 		if (cp)
2033 			*cp ^= d;
2034 		*rp++ = d;
2035 		dp++;
2036 	}
2037 	/*
2038 	 * do even bits
2039 	 */
2040 	dp = sdp;
2041 	while (dp < edp) {
2042 		d = *dp & 0x55555555;	/* remove clock bits */
2043 		dtmp = d ^ 0x55555555;
2044 		d |= ((dtmp >> 1) | 0x80000000) & (dtmp << 1);
2045 		/*
2046 		 * correct upper clock bit if needed
2047 		 */
2048 		if (correct)
2049 			d &= 0x7fffffff;
2050 		if (d & 0x1)
2051 			correct = 1;
2052 		else
2053 			correct = 0;
2054 		/*
2055 		 * do checksums and store in raw buffer
2056 		 */
2057 		if (cp)
2058 			*cp ^= d;
2059 		*rp++ = d;
2060 		dp++;
2061 	}
2062 	if (cp)
2063 		*cp &= 0x55555555;
2064 	return(rp);
2065 }
2066 
2067 /*
2068  * decode len longwords of `dp' data in amiga mfm block format (`rp')
2069  * this format specified that the odd bits are at current pos and even
2070  * bits at len + current pos
2071  */
2072 u_long *
2073 mfmblkdecode(u_long *rp, u_long *dp, u_long *cp, int len)
2074 {
2075 	u_long o, e;
2076 	int cnt;
2077 
2078 	cnt = len;
2079 	while (cnt--) {
2080 		o = *rp;
2081 		e = *(rp + len);
2082 		if (cp) {
2083 			*cp ^= o;
2084 			*cp ^= e;
2085 		}
2086 		o &= 0x55555555;
2087 		e &= 0x55555555;
2088 		*dp++ = (o << 1) | e;
2089 		rp++;
2090 	}
2091 	if (cp)
2092 		*cp &= 0x55555555;
2093 	return(rp + len);
2094 }
2095 
2096 /*
2097  * decode len words in standard MFM format to len bytes
2098  * of data.
2099  */
2100 u_short *
2101 msblkdecode(u_short *rp, u_char *cp, int len)
2102 {
2103 	while (len--) {
2104 		*cp++ = msdecode[*rp & 0x7f] |
2105 		    (msdecode[(*rp >> 8) & 0x7f] << 4);
2106 		rp++;
2107 	}
2108 
2109 	return(rp);
2110 }
2111 
2112 /*
2113  * encode len bytes of data into len words in standard MFM format.
2114  * If a pointer is supplied for crc, calculate the CRC-16 of the data
2115  * as well.
2116  */
2117 u_short *
2118 msblkencode(u_short *rp, u_char *cp, int len, u_short *crc)
2119 {
2120 	u_short td;
2121 	u_short mycrc;
2122 
2123 	/* preload crc for header (4 bytes)
2124 	 * or data (anything else)
2125 	 */
2126 	mycrc = (len == 4) ? 0xb230 : 0xe295;
2127 
2128 	while (len--) {
2129 		td = (msencode[*cp >> 4] << 8) | msencode[*cp & 0x0f];
2130 
2131 		/* Check for zeros in top bit of encode and bottom
2132 		 * bit of previous encode.  if so, slap a one in betweem
2133 		 * them.
2134 		 */
2135 		if ((td & 0x140) == 0)
2136 			td |= 0x80;
2137 		if ((td & 0x4000) == 0 && (rp[-1] & 1) == 0)
2138 			td |= 0x8000;
2139 
2140 		*rp++ = td;
2141 
2142 		/*
2143 		 * calc crc if requested
2144 		 */
2145 		if (crc)
2146 			mycrc = (mycrc << 8) ^ mscrctab[*cp ^ (mycrc >> 8)];
2147 
2148 		cp++;
2149 	}
2150 
2151 	if (crc)
2152 		*crc = mycrc;
2153 
2154 	return(rp);
2155 }
2156 
2157 int
2158 fddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
2159 {
2160 	return (EINVAL);
2161 }
2162