xref: /linux/drivers/block/amiflop.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/amiga/amiflop.c
4  *
5  *  Copyright (C) 1993  Greg Harp
6  *  Portions of this driver are based on code contributed by Brad Pepers
7  *
8  *  revised 28.5.95 by Joerg Dorchain
9  *  - now no bugs(?) any more for both HD & DD
10  *  - added support for 40 Track 5.25" drives, 80-track hopefully behaves
11  *    like 3.5" dd (no way to test - are there any 5.25" drives out there
12  *    that work on an A4000?)
13  *  - wrote formatting routine (maybe dirty, but works)
14  *
15  *  june/july 1995 added ms-dos support by Joerg Dorchain
16  *  (portions based on messydos.device and various contributors)
17  *  - currently only 9 and 18 sector disks
18  *
19  *  - fixed a bug with the internal trackbuffer when using multiple
20  *    disks the same time
21  *  - made formatting a bit safer
22  *  - added command line and machine based default for "silent" df0
23  *
24  *  december 1995 adapted for 1.2.13pl4 by Joerg Dorchain
25  *  - works but I think it's inefficient. (look in redo_fd_request)
26  *    But the changes were very efficient. (only three and a half lines)
27  *
28  *  january 1996 added special ioctl for tracking down read/write problems
29  *  - usage ioctl(d, RAW_TRACK, ptr); the raw track buffer (MFM-encoded data
30  *    is copied to area. (area should be large enough since no checking is
31  *    done - 30K is currently sufficient). return the actual size of the
32  *    trackbuffer
33  *  - replaced udelays() by a timer (CIAA timer B) for the waits
34  *    needed for the disk mechanic.
35  *
36  *  february 1996 fixed error recovery and multiple disk access
37  *  - both got broken the first time I tampered with the driver :-(
38  *  - still not safe, but better than before
39  *
40  *  revised Marts 3rd, 1996 by Jes Sorensen for use in the 1.3.28 kernel.
41  *  - Minor changes to accept the kdev_t.
42  *  - Replaced some more udelays with ms_delays. Udelay is just a loop,
43  *    and so the delay will be different depending on the given
44  *    processor :-(
45  *  - The driver could use a major cleanup because of the new
46  *    major/minor handling that came with kdev_t. It seems to work for
47  *    the time being, but I can't guarantee that it will stay like
48  *    that when we start using 16 (24?) bit minors.
49  *
50  * restructured jan 1997 by Joerg Dorchain
51  * - Fixed Bug accessing multiple disks
52  * - some code cleanup
53  * - added trackbuffer for each drive to speed things up
54  * - fixed some race conditions (who finds the next may send it to me ;-)
55  */
56 
57 #include <linux/module.h>
58 #include <linux/slab.h>
59 
60 #include <linux/fd.h>
61 #include <linux/hdreg.h>
62 #include <linux/delay.h>
63 #include <linux/init.h>
64 #include <linux/major.h>
65 #include <linux/mutex.h>
66 #include <linux/fs.h>
67 #include <linux/blk-mq.h>
68 #include <linux/interrupt.h>
69 #include <linux/platform_device.h>
70 
71 #include <asm/setup.h>
72 #include <linux/uaccess.h>
73 #include <asm/amigahw.h>
74 #include <asm/amigaints.h>
75 #include <asm/irq.h>
76 
77 #undef DEBUG /* print _LOTS_ of infos */
78 
79 #define RAW_IOCTL
80 #ifdef RAW_IOCTL
81 #define IOCTL_RAW_TRACK 0x5254524B  /* 'RTRK' */
82 #endif
83 
84 /*
85  *  Defines
86  */
87 
88 /*
89  * CIAAPRA bits (read only)
90  */
91 
92 #define DSKRDY      (0x1<<5)        /* disk ready when low */
93 #define DSKTRACK0   (0x1<<4)        /* head at track zero when low */
94 #define DSKPROT     (0x1<<3)        /* disk protected when low */
95 #define DSKCHANGE   (0x1<<2)        /* low when disk removed */
96 
97 /*
98  * CIAAPRB bits (read/write)
99  */
100 
101 #define DSKMOTOR    (0x1<<7)        /* motor on when low */
102 #define DSKSEL3     (0x1<<6)        /* select drive 3 when low */
103 #define DSKSEL2     (0x1<<5)        /* select drive 2 when low */
104 #define DSKSEL1     (0x1<<4)        /* select drive 1 when low */
105 #define DSKSEL0     (0x1<<3)        /* select drive 0 when low */
106 #define DSKSIDE     (0x1<<2)        /* side selection: 0 = upper, 1 = lower */
107 #define DSKDIREC    (0x1<<1)        /* step direction: 0=in, 1=out (to trk 0) */
108 #define DSKSTEP     (0x1)           /* pulse low to step head 1 track */
109 
110 /*
111  * DSKBYTR bits (read only)
112  */
113 
114 #define DSKBYT      (1<<15)         /* register contains valid byte when set */
115 #define DMAON       (1<<14)         /* disk DMA enabled */
116 #define DISKWRITE   (1<<13)         /* disk write bit in DSKLEN enabled */
117 #define WORDEQUAL   (1<<12)         /* DSKSYNC register match when true */
118 /* bits 7-0 are data */
119 
120 /*
121  * ADKCON/ADKCONR bits
122  */
123 
124 #ifndef SETCLR
125 #define ADK_SETCLR      (1<<15)     /* control bit */
126 #endif
127 #define ADK_PRECOMP1    (1<<14)     /* precompensation selection */
128 #define ADK_PRECOMP0    (1<<13)     /* 00=none, 01=140ns, 10=280ns, 11=500ns */
129 #define ADK_MFMPREC     (1<<12)     /* 0=GCR precomp., 1=MFM precomp. */
130 #define ADK_WORDSYNC    (1<<10)     /* enable DSKSYNC auto DMA */
131 #define ADK_MSBSYNC     (1<<9)      /* when 1, enable sync on MSbit (for GCR) */
132 #define ADK_FAST        (1<<8)      /* bit cell: 0=2us (GCR), 1=1us (MFM) */
133 
134 /*
135  * DSKLEN bits
136  */
137 
138 #define DSKLEN_DMAEN    (1<<15)
139 #define DSKLEN_WRITE    (1<<14)
140 
141 /*
142  * INTENA/INTREQ bits
143  */
144 
145 #define DSKINDEX    (0x1<<4)        /* DSKINDEX bit */
146 
147 /*
148  * Misc
149  */
150 
151 #define MFM_SYNC    0x4489          /* standard MFM sync value */
152 
153 /* Values for FD_COMMAND */
154 #define FD_RECALIBRATE		0x07	/* move to track 0 */
155 #define FD_SEEK			0x0F	/* seek track */
156 #define FD_READ			0xE6	/* read with MT, MFM, SKip deleted */
157 #define FD_WRITE		0xC5	/* write with MT, MFM */
158 #define FD_SENSEI		0x08	/* Sense Interrupt Status */
159 #define FD_SPECIFY		0x03	/* specify HUT etc */
160 #define FD_FORMAT		0x4D	/* format one track */
161 #define FD_VERSION		0x10	/* get version code */
162 #define FD_CONFIGURE		0x13	/* configure FIFO operation */
163 #define FD_PERPENDICULAR	0x12	/* perpendicular r/w mode */
164 
165 #define FD_MAX_UNITS    4	/* Max. Number of drives */
166 #define FLOPPY_MAX_SECTORS	22	/* Max. Number of sectors per track */
167 
168 struct fd_data_type {
169 	char *name;		/* description of data type */
170 	int sects;		/* sectors per track */
171 	int (*read_fkt)(int);	/* read whole track */
172 	void (*write_fkt)(int);	/* write whole track */
173 };
174 
175 struct fd_drive_type {
176 	unsigned long code;		/* code returned from drive */
177 	char *name;			/* description of drive */
178 	unsigned int tracks;	/* number of tracks */
179 	unsigned int heads;		/* number of heads */
180 	unsigned int read_size;	/* raw read size for one track */
181 	unsigned int write_size;	/* raw write size for one track */
182 	unsigned int sect_mult;	/* sectors and gap multiplier (HD = 2) */
183 	unsigned int precomp1;	/* start track for precomp 1 */
184 	unsigned int precomp2;	/* start track for precomp 2 */
185 	unsigned int step_delay;	/* time (in ms) for delay after step */
186 	unsigned int settle_time;	/* time to settle after dir change */
187 	unsigned int side_time;	/* time needed to change sides */
188 };
189 
190 struct amiga_floppy_struct {
191 	struct fd_drive_type *type;	/* type of floppy for this unit */
192 	struct fd_data_type *dtype;	/* type of floppy for this unit */
193 	int track;			/* current track (-1 == unknown) */
194 	unsigned char *trackbuf;	/* current track (kmaloc()'d */
195 
196 	int blocks;			/* total # blocks on disk */
197 
198 	int changed;			/* true when not known */
199 	int disk;			/* disk in drive (-1 == unknown) */
200 	int motor;			/* true when motor is at speed */
201 	int busy;			/* true when drive is active */
202 	int dirty;			/* true when trackbuf is not on disk */
203 	int status;			/* current error code for unit */
204 	struct gendisk *gendisk[2];
205 	struct blk_mq_tag_set tag_set;
206 };
207 
208 /*
209  *  Error codes
210  */
211 #define FD_OK		0	/* operation succeeded */
212 #define FD_ERROR	-1	/* general error (seek, read, write, etc) */
213 #define FD_NOUNIT	1	/* unit does not exist */
214 #define FD_UNITBUSY	2	/* unit already active */
215 #define FD_NOTACTIVE	3	/* unit is not active */
216 #define FD_NOTREADY	4	/* unit is not ready (motor not on/no disk) */
217 
218 #define MFM_NOSYNC	1
219 #define MFM_HEADER	2
220 #define MFM_DATA	3
221 #define MFM_TRACK	4
222 
223 /*
224  *  Floppy ID values
225  */
226 #define FD_NODRIVE	0x00000000  /* response when no unit is present */
227 #define FD_DD_3 	0xffffffff  /* double-density 3.5" (880K) drive */
228 #define FD_HD_3 	0x55555555  /* high-density 3.5" (1760K) drive */
229 #define FD_DD_5 	0xaaaaaaaa  /* double-density 5.25" (440K) drive */
230 
231 static DEFINE_MUTEX(amiflop_mutex);
232 static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it doesn't identify */
233 
234 module_param(fd_def_df0, ulong, 0);
235 MODULE_DESCRIPTION("Amiga floppy driver");
236 MODULE_LICENSE("GPL");
237 
238 /*
239  *  Macros
240  */
241 #define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
242 #define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
243 #define SELECT(mask)    (ciab.prb &= ~mask)
244 #define DESELECT(mask)  (ciab.prb |= mask)
245 #define SELMASK(drive)  (1 << (3 + (drive & 3)))
246 
247 static struct fd_drive_type drive_types[] = {
248 /*  code	name	   tr he   rdsz   wrsz sm pc1 pc2 sd  st st*/
249 /*  warning: times are now in milliseconds (ms)                    */
250 { FD_DD_3,	"DD 3.5",  80, 2, 14716, 13630, 1, 80,161, 3, 18, 1},
251 { FD_HD_3,	"HD 3.5",  80, 2, 28344, 27258, 2, 80,161, 3, 18, 1},
252 { FD_DD_5,	"DD 5.25", 40, 2, 14716, 13630, 1, 40, 81, 6, 30, 2},
253 { FD_NODRIVE, "No Drive", 0, 0,     0,     0, 0,  0,  0,  0,  0, 0}
254 };
255 static int num_dr_types = ARRAY_SIZE(drive_types);
256 
257 static int amiga_read(int), dos_read(int);
258 static void amiga_write(int), dos_write(int);
259 static struct fd_data_type data_types[] = {
260 	{ "Amiga", 11 , amiga_read, amiga_write},
261 	{ "MS-Dos", 9, dos_read, dos_write}
262 };
263 
264 /* current info on each unit */
265 static struct amiga_floppy_struct unit[FD_MAX_UNITS];
266 
267 static struct timer_list flush_track_timer[FD_MAX_UNITS];
268 static struct timer_list post_write_timer;
269 static unsigned long post_write_timer_drive;
270 static struct timer_list motor_on_timer;
271 static struct timer_list motor_off_timer[FD_MAX_UNITS];
272 static int on_attempts;
273 
274 /* Synchronization of FDC access */
275 /* request loop (trackbuffer) */
276 static volatile int fdc_busy = -1;
277 static volatile int fdc_nested;
278 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
279 
280 static DECLARE_COMPLETION(motor_on_completion);
281 
282 static volatile int selected = -1;	/* currently selected drive */
283 
284 static int writepending;
285 static int writefromint;
286 static char *raw_buf;
287 
288 static DEFINE_SPINLOCK(amiflop_lock);
289 
290 #define RAW_BUF_SIZE 30000  /* size of raw disk data */
291 
292 /*
293  * These are global variables, as that's the easiest way to give
294  * information to interrupts. They are the data used for the current
295  * request.
296  */
297 static volatile char block_flag;
298 static DECLARE_WAIT_QUEUE_HEAD(wait_fd_block);
299 
300 /* MS-Dos MFM Coding tables (should go quick and easy) */
301 static unsigned char mfmencode[16]={
302 	0x2a, 0x29, 0x24, 0x25, 0x12, 0x11, 0x14, 0x15,
303 	0x4a, 0x49, 0x44, 0x45, 0x52, 0x51, 0x54, 0x55
304 };
305 static unsigned char mfmdecode[128];
306 
307 /* floppy internal millisecond timer stuff */
308 static DECLARE_COMPLETION(ms_wait_completion);
309 #define MS_TICKS ((amiga_eclock+50)/1000)
310 
311 /*
312  * Note that MAX_ERRORS=X doesn't imply that we retry every bad read
313  * max X times - some types of errors increase the errorcount by 2 or
314  * even 3, so we might actually retry only X/2 times before giving up.
315  */
316 #define MAX_ERRORS 12
317 
318 #define custom amiga_custom
319 
320 /* Prevent "aliased" accesses. */
321 static int fd_ref[4] = { 0,0,0,0 };
322 static int fd_device[4] = { 0, 0, 0, 0 };
323 
324 /*
325  * Here come the actual hardware access and helper functions.
326  * They are not reentrant and single threaded because all drives
327  * share the same hardware and the same trackbuffer.
328  */
329 
330 /* Milliseconds timer */
331 
332 static irqreturn_t ms_isr(int irq, void *dummy)
333 {
334 	complete(&ms_wait_completion);
335 	return IRQ_HANDLED;
336 }
337 
338 /* all waits are queued up
339    A more generic routine would do a schedule a la timer.device */
340 static void ms_delay(int ms)
341 {
342 	int ticks;
343 	static DEFINE_MUTEX(mutex);
344 
345 	if (ms > 0) {
346 		mutex_lock(&mutex);
347 		ticks = MS_TICKS*ms-1;
348 		ciaa.tblo=ticks%256;
349 		ciaa.tbhi=ticks/256;
350 		ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
351 		wait_for_completion(&ms_wait_completion);
352 		mutex_unlock(&mutex);
353 	}
354 }
355 
356 /* Hardware semaphore */
357 
358 /* returns true when we would get the semaphore */
359 static inline int try_fdc(int drive)
360 {
361 	drive &= 3;
362 	return ((fdc_busy < 0) || (fdc_busy == drive));
363 }
364 
365 static void get_fdc(int drive)
366 {
367 	unsigned long flags;
368 
369 	drive &= 3;
370 #ifdef DEBUG
371 	printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
372 #endif
373 	local_irq_save(flags);
374 	wait_event(fdc_wait, try_fdc(drive));
375 	fdc_busy = drive;
376 	fdc_nested++;
377 	local_irq_restore(flags);
378 }
379 
380 static inline void rel_fdc(void)
381 {
382 #ifdef DEBUG
383 	if (fdc_nested == 0)
384 		printk("fd: unmatched rel_fdc\n");
385 	printk("rel_fdc: fdc_busy %d fdc_nested %d\n",fdc_busy,fdc_nested);
386 #endif
387 	fdc_nested--;
388 	if (fdc_nested == 0) {
389 		fdc_busy = -1;
390 		wake_up(&fdc_wait);
391 	}
392 }
393 
394 static void fd_select (int drive)
395 {
396 	unsigned char prb = ~0;
397 
398 	drive&=3;
399 #ifdef DEBUG
400 	printk("selecting %d\n",drive);
401 #endif
402 	if (drive == selected)
403 		return;
404 	get_fdc(drive);
405 	selected = drive;
406 
407 	if (unit[drive].track % 2 != 0)
408 		prb &= ~DSKSIDE;
409 	if (unit[drive].motor == 1)
410 		prb &= ~DSKMOTOR;
411 	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
412 	ciab.prb = prb;
413 	prb &= ~SELMASK(drive);
414 	ciab.prb = prb;
415 	rel_fdc();
416 }
417 
418 static void fd_deselect (int drive)
419 {
420 	unsigned char prb;
421 	unsigned long flags;
422 
423 	drive&=3;
424 #ifdef DEBUG
425 	printk("deselecting %d\n",drive);
426 #endif
427 	if (drive != selected) {
428 		printk(KERN_WARNING "Deselecting drive %d while %d was selected!\n",drive,selected);
429 		return;
430 	}
431 
432 	get_fdc(drive);
433 	local_irq_save(flags);
434 
435 	selected = -1;
436 
437 	prb = ciab.prb;
438 	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));
439 	ciab.prb = prb;
440 
441 	local_irq_restore (flags);
442 	rel_fdc();
443 
444 }
445 
446 static void motor_on_callback(struct timer_list *unused)
447 {
448 	if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
449 		complete_all(&motor_on_completion);
450 	} else {
451 		motor_on_timer.expires = jiffies + HZ/10;
452 		add_timer(&motor_on_timer);
453 	}
454 }
455 
456 static int fd_motor_on(int nr)
457 {
458 	nr &= 3;
459 
460 	del_timer(motor_off_timer + nr);
461 
462 	if (!unit[nr].motor) {
463 		unit[nr].motor = 1;
464 		fd_select(nr);
465 
466 		reinit_completion(&motor_on_completion);
467 		mod_timer(&motor_on_timer, jiffies + HZ/2);
468 
469 		on_attempts = 10;
470 		wait_for_completion(&motor_on_completion);
471 		fd_deselect(nr);
472 	}
473 
474 	if (on_attempts == 0) {
475 		on_attempts = -1;
476 #if 0
477 		printk (KERN_ERR "motor_on failed, turning motor off\n");
478 		fd_motor_off (motor_off_timer + nr);
479 		return 0;
480 #else
481 		printk (KERN_WARNING "DSKRDY not set after 1.5 seconds - assuming drive is spinning notwithstanding\n");
482 #endif
483 	}
484 
485 	return 1;
486 }
487 
488 static void fd_motor_off(struct timer_list *timer)
489 {
490 	unsigned long drive = ((unsigned long)timer -
491 			       (unsigned long)&motor_off_timer[0]) /
492 					sizeof(motor_off_timer[0]);
493 
494 	drive&=3;
495 	if (!try_fdc(drive)) {
496 		/* We would be blocked in an interrupt, so try again later */
497 		timer->expires = jiffies + 1;
498 		add_timer(timer);
499 		return;
500 	}
501 	unit[drive].motor = 0;
502 	fd_select(drive);
503 	udelay (1);
504 	fd_deselect(drive);
505 }
506 
507 static void floppy_off (unsigned int nr)
508 {
509 	int drive;
510 
511 	drive = nr & 3;
512 	mod_timer(motor_off_timer + drive, jiffies + 3*HZ);
513 }
514 
515 static int fd_calibrate(int drive)
516 {
517 	unsigned char prb;
518 	int n;
519 
520 	drive &= 3;
521 	get_fdc(drive);
522 	if (!fd_motor_on (drive))
523 		return 0;
524 	fd_select (drive);
525 	prb = ciab.prb;
526 	prb |= DSKSIDE;
527 	prb &= ~DSKDIREC;
528 	ciab.prb = prb;
529 	for (n = unit[drive].type->tracks/2; n != 0; --n) {
530 		if (ciaa.pra & DSKTRACK0)
531 			break;
532 		prb &= ~DSKSTEP;
533 		ciab.prb = prb;
534 		prb |= DSKSTEP;
535 		udelay (2);
536 		ciab.prb = prb;
537 		ms_delay(unit[drive].type->step_delay);
538 	}
539 	ms_delay (unit[drive].type->settle_time);
540 	prb |= DSKDIREC;
541 	n = unit[drive].type->tracks + 20;
542 	for (;;) {
543 		prb &= ~DSKSTEP;
544 		ciab.prb = prb;
545 		prb |= DSKSTEP;
546 		udelay (2);
547 		ciab.prb = prb;
548 		ms_delay(unit[drive].type->step_delay + 1);
549 		if ((ciaa.pra & DSKTRACK0) == 0)
550 			break;
551 		if (--n == 0) {
552 			printk (KERN_ERR "fd%d: calibrate failed, turning motor off\n", drive);
553 			fd_motor_off (motor_off_timer + drive);
554 			unit[drive].track = -1;
555 			rel_fdc();
556 			return 0;
557 		}
558 	}
559 	unit[drive].track = 0;
560 	ms_delay(unit[drive].type->settle_time);
561 
562 	rel_fdc();
563 	fd_deselect(drive);
564 	return 1;
565 }
566 
567 static int fd_seek(int drive, int track)
568 {
569 	unsigned char prb;
570 	int cnt;
571 
572 #ifdef DEBUG
573 	printk("seeking drive %d to track %d\n",drive,track);
574 #endif
575 	drive &= 3;
576 	get_fdc(drive);
577 	if (unit[drive].track == track) {
578 		rel_fdc();
579 		return 1;
580 	}
581 	if (!fd_motor_on(drive)) {
582 		rel_fdc();
583 		return 0;
584 	}
585 	if (unit[drive].track < 0 && !fd_calibrate(drive)) {
586 		rel_fdc();
587 		return 0;
588 	}
589 
590 	fd_select (drive);
591 	cnt = unit[drive].track/2 - track/2;
592 	prb = ciab.prb;
593 	prb |= DSKSIDE | DSKDIREC;
594 	if (track % 2 != 0)
595 		prb &= ~DSKSIDE;
596 	if (cnt < 0) {
597 		cnt = - cnt;
598 		prb &= ~DSKDIREC;
599 	}
600 	ciab.prb = prb;
601 	if (track % 2 != unit[drive].track % 2)
602 		ms_delay (unit[drive].type->side_time);
603 	unit[drive].track = track;
604 	if (cnt == 0) {
605 		rel_fdc();
606 		fd_deselect(drive);
607 		return 1;
608 	}
609 	do {
610 		prb &= ~DSKSTEP;
611 		ciab.prb = prb;
612 		prb |= DSKSTEP;
613 		udelay (1);
614 		ciab.prb = prb;
615 		ms_delay (unit[drive].type->step_delay);
616 	} while (--cnt != 0);
617 	ms_delay (unit[drive].type->settle_time);
618 
619 	rel_fdc();
620 	fd_deselect(drive);
621 	return 1;
622 }
623 
624 static unsigned long fd_get_drive_id(int drive)
625 {
626 	int i;
627 	ulong id = 0;
628 
629   	drive&=3;
630   	get_fdc(drive);
631 	/* set up for ID */
632 	MOTOR_ON;
633 	udelay(2);
634 	SELECT(SELMASK(drive));
635 	udelay(2);
636 	DESELECT(SELMASK(drive));
637 	udelay(2);
638 	MOTOR_OFF;
639 	udelay(2);
640 	SELECT(SELMASK(drive));
641 	udelay(2);
642 	DESELECT(SELMASK(drive));
643 	udelay(2);
644 
645 	/* loop and read disk ID */
646 	for (i=0; i<32; i++) {
647 		SELECT(SELMASK(drive));
648 		udelay(2);
649 
650 		/* read and store value of DSKRDY */
651 		id <<= 1;
652 		id |= (ciaa.pra & DSKRDY) ? 0 : 1;	/* cia regs are low-active! */
653 
654 		DESELECT(SELMASK(drive));
655 	}
656 
657 	rel_fdc();
658 
659         /*
660          * RB: At least A500/A2000's df0: don't identify themselves.
661          * As every (real) Amiga has at least a 3.5" DD drive as df0:
662          * we default to that if df0: doesn't identify as a certain
663          * type.
664          */
665         if(drive == 0 && id == FD_NODRIVE)
666 	{
667                 id = fd_def_df0;
668                 printk(KERN_NOTICE "fd: drive 0 didn't identify, setting default %08lx\n", (ulong)fd_def_df0);
669 	}
670 	/* return the ID value */
671 	return (id);
672 }
673 
674 static irqreturn_t fd_block_done(int irq, void *dummy)
675 {
676 	if (block_flag)
677 		custom.dsklen = 0x4000;
678 
679 	if (block_flag == 2) { /* writing */
680 		writepending = 2;
681 		post_write_timer.expires = jiffies + 1; /* at least 2 ms */
682 		post_write_timer_drive = selected;
683 		add_timer(&post_write_timer);
684 	}
685 	else {                /* reading */
686 		block_flag = 0;
687 		wake_up (&wait_fd_block);
688 	}
689 	return IRQ_HANDLED;
690 }
691 
692 static void raw_read(int drive)
693 {
694 	drive&=3;
695 	get_fdc(drive);
696 	wait_event(wait_fd_block, !block_flag);
697 	fd_select(drive);
698 	/* setup adkcon bits correctly */
699 	custom.adkcon = ADK_MSBSYNC;
700 	custom.adkcon = ADK_SETCLR|ADK_WORDSYNC|ADK_FAST;
701 
702 	custom.dsksync = MFM_SYNC;
703 
704 	custom.dsklen = 0;
705 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
706 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
707 	custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
708 
709 	block_flag = 1;
710 
711 	wait_event(wait_fd_block, !block_flag);
712 
713 	custom.dsklen = 0;
714 	fd_deselect(drive);
715 	rel_fdc();
716 }
717 
718 static int raw_write(int drive)
719 {
720 	ushort adk;
721 
722 	drive&=3;
723 	get_fdc(drive); /* corresponds to rel_fdc() in post_write() */
724 	if ((ciaa.pra & DSKPROT) == 0) {
725 		rel_fdc();
726 		return 0;
727 	}
728 	wait_event(wait_fd_block, !block_flag);
729 	fd_select(drive);
730 	/* clear adkcon bits */
731 	custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
732 	/* set appropriate adkcon bits */
733 	adk = ADK_SETCLR|ADK_FAST;
734 	if ((ulong)unit[drive].track >= unit[drive].type->precomp2)
735 		adk |= ADK_PRECOMP1;
736 	else if ((ulong)unit[drive].track >= unit[drive].type->precomp1)
737 		adk |= ADK_PRECOMP0;
738 	custom.adkcon = adk;
739 
740 	custom.dsklen = DSKLEN_WRITE;
741 	custom.dskptr = (u_char *)ZTWO_PADDR((u_char *)raw_buf);
742 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
743 	custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
744 
745 	block_flag = 2;
746 	return 1;
747 }
748 
749 /*
750  * to be called at least 2ms after the write has finished but before any
751  * other access to the hardware.
752  */
753 static void post_write (unsigned long drive)
754 {
755 #ifdef DEBUG
756 	printk("post_write for drive %ld\n",drive);
757 #endif
758 	drive &= 3;
759 	custom.dsklen = 0;
760 	block_flag = 0;
761 	writepending = 0;
762 	writefromint = 0;
763 	unit[drive].dirty = 0;
764 	wake_up(&wait_fd_block);
765 	fd_deselect(drive);
766 	rel_fdc(); /* corresponds to get_fdc() in raw_write */
767 }
768 
769 static void post_write_callback(struct timer_list *timer)
770 {
771 	post_write(post_write_timer_drive);
772 }
773 
774 /*
775  * The following functions are to convert the block contents into raw data
776  * written to disk and vice versa.
777  * (Add other formats here ;-))
778  */
779 
780 static unsigned long scan_sync(unsigned long raw, unsigned long end)
781 {
782 	ushort *ptr = (ushort *)raw, *endp = (ushort *)end;
783 
784 	while (ptr < endp && *ptr++ != 0x4489)
785 		;
786 	if (ptr < endp) {
787 		while (*ptr == 0x4489 && ptr < endp)
788 			ptr++;
789 		return (ulong)ptr;
790 	}
791 	return 0;
792 }
793 
794 static inline unsigned long checksum(unsigned long *addr, int len)
795 {
796 	unsigned long csum = 0;
797 
798 	len /= sizeof(*addr);
799 	while (len-- > 0)
800 		csum ^= *addr++;
801 	csum = ((csum>>1) & 0x55555555)  ^  (csum & 0x55555555);
802 
803 	return csum;
804 }
805 
806 static unsigned long decode (unsigned long *data, unsigned long *raw,
807 			     int len)
808 {
809 	ulong *odd, *even;
810 
811 	/* convert length from bytes to longwords */
812 	len >>= 2;
813 	odd = raw;
814 	even = odd + len;
815 
816 	/* prepare return pointer */
817 	raw += len * 2;
818 
819 	do {
820 		*data++ = ((*odd++ & 0x55555555) << 1) | (*even++ & 0x55555555);
821 	} while (--len != 0);
822 
823 	return (ulong)raw;
824 }
825 
826 struct header {
827 	unsigned char magic;
828 	unsigned char track;
829 	unsigned char sect;
830 	unsigned char ord;
831 	unsigned char labels[16];
832 	unsigned long hdrchk;
833 	unsigned long datachk;
834 };
835 
836 static int amiga_read(int drive)
837 {
838 	unsigned long raw;
839 	unsigned long end;
840 	int scnt;
841 	unsigned long csum;
842 	struct header hdr;
843 
844 	drive&=3;
845 	raw = (long) raw_buf;
846 	end = raw + unit[drive].type->read_size;
847 
848 	for (scnt = 0;scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
849 		if (!(raw = scan_sync(raw, end))) {
850 			printk (KERN_INFO "can't find sync for sector %d\n", scnt);
851 			return MFM_NOSYNC;
852 		}
853 
854 		raw = decode ((ulong *)&hdr.magic, (ulong *)raw, 4);
855 		raw = decode ((ulong *)&hdr.labels, (ulong *)raw, 16);
856 		raw = decode ((ulong *)&hdr.hdrchk, (ulong *)raw, 4);
857 		raw = decode ((ulong *)&hdr.datachk, (ulong *)raw, 4);
858 		csum = checksum((ulong *)&hdr,
859 				(char *)&hdr.hdrchk-(char *)&hdr);
860 
861 #ifdef DEBUG
862 		printk ("(%x,%d,%d,%d) (%lx,%lx,%lx,%lx) %lx %lx\n",
863 			hdr.magic, hdr.track, hdr.sect, hdr.ord,
864 			*(ulong *)&hdr.labels[0], *(ulong *)&hdr.labels[4],
865 			*(ulong *)&hdr.labels[8], *(ulong *)&hdr.labels[12],
866 			hdr.hdrchk, hdr.datachk);
867 #endif
868 
869 		if (hdr.hdrchk != csum) {
870 			printk(KERN_INFO "MFM_HEADER: %08lx,%08lx\n", hdr.hdrchk, csum);
871 			return MFM_HEADER;
872 		}
873 
874 		/* verify track */
875 		if (hdr.track != unit[drive].track) {
876 			printk(KERN_INFO "MFM_TRACK: %d, %d\n", hdr.track, unit[drive].track);
877 			return MFM_TRACK;
878 		}
879 
880 		raw = decode ((ulong *)(unit[drive].trackbuf + hdr.sect*512),
881 			      (ulong *)raw, 512);
882 		csum = checksum((ulong *)(unit[drive].trackbuf + hdr.sect*512), 512);
883 
884 		if (hdr.datachk != csum) {
885 			printk(KERN_INFO "MFM_DATA: (%x:%d:%d:%d) sc=%d %lx, %lx\n",
886 			       hdr.magic, hdr.track, hdr.sect, hdr.ord, scnt,
887 			       hdr.datachk, csum);
888 			printk (KERN_INFO "data=(%lx,%lx,%lx,%lx)\n",
889 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[0],
890 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[1],
891 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[2],
892 				((ulong *)(unit[drive].trackbuf+hdr.sect*512))[3]);
893 			return MFM_DATA;
894 		}
895 	}
896 
897 	return 0;
898 }
899 
900 static void encode(unsigned long data, unsigned long *dest)
901 {
902 	unsigned long data2;
903 
904 	data &= 0x55555555;
905 	data2 = data ^ 0x55555555;
906 	data |= ((data2 >> 1) | 0x80000000) & (data2 << 1);
907 
908 	if (*(dest - 1) & 0x00000001)
909 		data &= 0x7FFFFFFF;
910 
911 	*dest = data;
912 }
913 
914 static void encode_block(unsigned long *dest, unsigned long *src, int len)
915 {
916 	int cnt, to_cnt = 0;
917 	unsigned long data;
918 
919 	/* odd bits */
920 	for (cnt = 0; cnt < len / 4; cnt++) {
921 		data = src[cnt] >> 1;
922 		encode(data, dest + to_cnt++);
923 	}
924 
925 	/* even bits */
926 	for (cnt = 0; cnt < len / 4; cnt++) {
927 		data = src[cnt];
928 		encode(data, dest + to_cnt++);
929 	}
930 }
931 
932 static unsigned long *putsec(int disk, unsigned long *raw, int cnt)
933 {
934 	struct header hdr;
935 	int i;
936 
937 	disk&=3;
938 	*raw = (raw[-1]&1) ? 0x2AAAAAAA : 0xAAAAAAAA;
939 	raw++;
940 	*raw++ = 0x44894489;
941 
942 	hdr.magic = 0xFF;
943 	hdr.track = unit[disk].track;
944 	hdr.sect = cnt;
945 	hdr.ord = unit[disk].dtype->sects * unit[disk].type->sect_mult - cnt;
946 	for (i = 0; i < 16; i++)
947 		hdr.labels[i] = 0;
948 	hdr.hdrchk = checksum((ulong *)&hdr,
949 			      (char *)&hdr.hdrchk-(char *)&hdr);
950 	hdr.datachk = checksum((ulong *)(unit[disk].trackbuf+cnt*512), 512);
951 
952 	encode_block(raw, (ulong *)&hdr.magic, 4);
953 	raw += 2;
954 	encode_block(raw, (ulong *)&hdr.labels, 16);
955 	raw += 8;
956 	encode_block(raw, (ulong *)&hdr.hdrchk, 4);
957 	raw += 2;
958 	encode_block(raw, (ulong *)&hdr.datachk, 4);
959 	raw += 2;
960 	encode_block(raw, (ulong *)(unit[disk].trackbuf+cnt*512), 512);
961 	raw += 256;
962 
963 	return raw;
964 }
965 
966 static void amiga_write(int disk)
967 {
968 	unsigned int cnt;
969 	unsigned long *ptr = (unsigned long *)raw_buf;
970 
971 	disk&=3;
972 	/* gap space */
973 	for (cnt = 0; cnt < 415 * unit[disk].type->sect_mult; cnt++)
974 		*ptr++ = 0xaaaaaaaa;
975 
976 	/* sectors */
977 	for (cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
978 		ptr = putsec (disk, ptr, cnt);
979 	*(ushort *)ptr = (ptr[-1]&1) ? 0x2AA8 : 0xAAA8;
980 }
981 
982 
983 struct dos_header {
984 	unsigned char track,   /* 0-80 */
985 		side,    /* 0-1 */
986 		sec,     /* 0-...*/
987 		len_desc;/* 2 */
988 	unsigned short crc;     /* on 68000 we got an alignment problem,
989 				   but this compiler solves it  by adding silently
990 				   adding a pad byte so data won't fit
991 				   and this took about 3h to discover.... */
992 	unsigned char gap1[22];     /* for longword-alignedness (0x4e) */
993 };
994 
995 /* crc routines are borrowed from the messydos-handler  */
996 
997 /* excerpt from the messydos-device
998 ; The CRC is computed not only over the actual data, but including
999 ; the SYNC mark (3 * $a1) and the 'ID/DATA - Address Mark' ($fe/$fb).
1000 ; As we don't read or encode these fields into our buffers, we have to
1001 ; preload the registers containing the CRC with the values they would have
1002 ; after stepping over these fields.
1003 ;
1004 ; How CRCs "really" work:
1005 ;
1006 ; First, you should regard a bitstring as a series of coefficients of
1007 ; polynomials. We calculate with these polynomials in modulo-2
1008 ; arithmetic, in which both add and subtract are done the same as
1009 ; exclusive-or. Now, we modify our data (a very long polynomial) in
1010 ; such a way that it becomes divisible by the CCITT-standard 16-bit
1011 ;		 16   12   5
1012 ; polynomial:	x  + x	+ x + 1, represented by $11021. The easiest
1013 ; way to do this would be to multiply (using proper arithmetic) our
1014 ; datablock with $11021. So we have:
1015 ;   data * $11021		 =
1016 ;   data * ($10000 + $1021)      =
1017 ;   data * $10000 + data * $1021
1018 ; The left part of this is simple: Just add two 0 bytes. But then
1019 ; the right part (data $1021) remains difficult and even could have
1020 ; a carry into the left part. The solution is to use a modified
1021 ; multiplication, which has a result that is not correct, but with
1022 ; a difference of any multiple of $11021. We then only need to keep
1023 ; the 16 least significant bits of the result.
1024 ;
1025 ; The following algorithm does this for us:
1026 ;
1027 ;   unsigned char *data, c, crclo, crchi;
1028 ;   while (not done) {
1029 ;	c = *data++ + crchi;
1030 ;	crchi = (@ c) >> 8 + crclo;
1031 ;	crclo = @ c;
1032 ;   }
1033 ;
1034 ; Remember, + is done with EOR, the @ operator is in two tables (high
1035 ; and low byte separately), which is calculated as
1036 ;
1037 ;      $1021 * (c & $F0)
1038 ;  xor $1021 * (c & $0F)
1039 ;  xor $1021 * (c >> 4)         (* is regular multiplication)
1040 ;
1041 ;
1042 ; Anyway, the end result is the same as the remainder of the division of
1043 ; the data by $11021. I am afraid I need to study theory a bit more...
1044 
1045 
1046 my only works was to code this from manx to C....
1047 
1048 */
1049 
1050 static ushort dos_crc(void * data_a3, int data_d0, int data_d1, int data_d3)
1051 {
1052 	static unsigned char CRCTable1[] = {
1053 		0x00,0x10,0x20,0x30,0x40,0x50,0x60,0x70,0x81,0x91,0xa1,0xb1,0xc1,0xd1,0xe1,0xf1,
1054 		0x12,0x02,0x32,0x22,0x52,0x42,0x72,0x62,0x93,0x83,0xb3,0xa3,0xd3,0xc3,0xf3,0xe3,
1055 		0x24,0x34,0x04,0x14,0x64,0x74,0x44,0x54,0xa5,0xb5,0x85,0x95,0xe5,0xf5,0xc5,0xd5,
1056 		0x36,0x26,0x16,0x06,0x76,0x66,0x56,0x46,0xb7,0xa7,0x97,0x87,0xf7,0xe7,0xd7,0xc7,
1057 		0x48,0x58,0x68,0x78,0x08,0x18,0x28,0x38,0xc9,0xd9,0xe9,0xf9,0x89,0x99,0xa9,0xb9,
1058 		0x5a,0x4a,0x7a,0x6a,0x1a,0x0a,0x3a,0x2a,0xdb,0xcb,0xfb,0xeb,0x9b,0x8b,0xbb,0xab,
1059 		0x6c,0x7c,0x4c,0x5c,0x2c,0x3c,0x0c,0x1c,0xed,0xfd,0xcd,0xdd,0xad,0xbd,0x8d,0x9d,
1060 		0x7e,0x6e,0x5e,0x4e,0x3e,0x2e,0x1e,0x0e,0xff,0xef,0xdf,0xcf,0xbf,0xaf,0x9f,0x8f,
1061 		0x91,0x81,0xb1,0xa1,0xd1,0xc1,0xf1,0xe1,0x10,0x00,0x30,0x20,0x50,0x40,0x70,0x60,
1062 		0x83,0x93,0xa3,0xb3,0xc3,0xd3,0xe3,0xf3,0x02,0x12,0x22,0x32,0x42,0x52,0x62,0x72,
1063 		0xb5,0xa5,0x95,0x85,0xf5,0xe5,0xd5,0xc5,0x34,0x24,0x14,0x04,0x74,0x64,0x54,0x44,
1064 		0xa7,0xb7,0x87,0x97,0xe7,0xf7,0xc7,0xd7,0x26,0x36,0x06,0x16,0x66,0x76,0x46,0x56,
1065 		0xd9,0xc9,0xf9,0xe9,0x99,0x89,0xb9,0xa9,0x58,0x48,0x78,0x68,0x18,0x08,0x38,0x28,
1066 		0xcb,0xdb,0xeb,0xfb,0x8b,0x9b,0xab,0xbb,0x4a,0x5a,0x6a,0x7a,0x0a,0x1a,0x2a,0x3a,
1067 		0xfd,0xed,0xdd,0xcd,0xbd,0xad,0x9d,0x8d,0x7c,0x6c,0x5c,0x4c,0x3c,0x2c,0x1c,0x0c,
1068 		0xef,0xff,0xcf,0xdf,0xaf,0xbf,0x8f,0x9f,0x6e,0x7e,0x4e,0x5e,0x2e,0x3e,0x0e,0x1e
1069 	};
1070 
1071 	static unsigned char CRCTable2[] = {
1072 		0x00,0x21,0x42,0x63,0x84,0xa5,0xc6,0xe7,0x08,0x29,0x4a,0x6b,0x8c,0xad,0xce,0xef,
1073 		0x31,0x10,0x73,0x52,0xb5,0x94,0xf7,0xd6,0x39,0x18,0x7b,0x5a,0xbd,0x9c,0xff,0xde,
1074 		0x62,0x43,0x20,0x01,0xe6,0xc7,0xa4,0x85,0x6a,0x4b,0x28,0x09,0xee,0xcf,0xac,0x8d,
1075 		0x53,0x72,0x11,0x30,0xd7,0xf6,0x95,0xb4,0x5b,0x7a,0x19,0x38,0xdf,0xfe,0x9d,0xbc,
1076 		0xc4,0xe5,0x86,0xa7,0x40,0x61,0x02,0x23,0xcc,0xed,0x8e,0xaf,0x48,0x69,0x0a,0x2b,
1077 		0xf5,0xd4,0xb7,0x96,0x71,0x50,0x33,0x12,0xfd,0xdc,0xbf,0x9e,0x79,0x58,0x3b,0x1a,
1078 		0xa6,0x87,0xe4,0xc5,0x22,0x03,0x60,0x41,0xae,0x8f,0xec,0xcd,0x2a,0x0b,0x68,0x49,
1079 		0x97,0xb6,0xd5,0xf4,0x13,0x32,0x51,0x70,0x9f,0xbe,0xdd,0xfc,0x1b,0x3a,0x59,0x78,
1080 		0x88,0xa9,0xca,0xeb,0x0c,0x2d,0x4e,0x6f,0x80,0xa1,0xc2,0xe3,0x04,0x25,0x46,0x67,
1081 		0xb9,0x98,0xfb,0xda,0x3d,0x1c,0x7f,0x5e,0xb1,0x90,0xf3,0xd2,0x35,0x14,0x77,0x56,
1082 		0xea,0xcb,0xa8,0x89,0x6e,0x4f,0x2c,0x0d,0xe2,0xc3,0xa0,0x81,0x66,0x47,0x24,0x05,
1083 		0xdb,0xfa,0x99,0xb8,0x5f,0x7e,0x1d,0x3c,0xd3,0xf2,0x91,0xb0,0x57,0x76,0x15,0x34,
1084 		0x4c,0x6d,0x0e,0x2f,0xc8,0xe9,0x8a,0xab,0x44,0x65,0x06,0x27,0xc0,0xe1,0x82,0xa3,
1085 		0x7d,0x5c,0x3f,0x1e,0xf9,0xd8,0xbb,0x9a,0x75,0x54,0x37,0x16,0xf1,0xd0,0xb3,0x92,
1086 		0x2e,0x0f,0x6c,0x4d,0xaa,0x8b,0xe8,0xc9,0x26,0x07,0x64,0x45,0xa2,0x83,0xe0,0xc1,
1087 		0x1f,0x3e,0x5d,0x7c,0x9b,0xba,0xd9,0xf8,0x17,0x36,0x55,0x74,0x93,0xb2,0xd1,0xf0
1088 	};
1089 
1090 /* look at the asm-code - what looks in C a bit strange is almost as good as handmade */
1091 	register int i;
1092 	register unsigned char *CRCT1, *CRCT2, *data, c, crch, crcl;
1093 
1094 	CRCT1=CRCTable1;
1095 	CRCT2=CRCTable2;
1096 	data=data_a3;
1097 	crcl=data_d1;
1098 	crch=data_d0;
1099 	for (i=data_d3; i>=0; i--) {
1100 		c = (*data++) ^ crch;
1101 		crch = CRCT1[c] ^ crcl;
1102 		crcl = CRCT2[c];
1103 	}
1104 	return (crch<<8)|crcl;
1105 }
1106 
1107 static inline ushort dos_hdr_crc (struct dos_header *hdr)
1108 {
1109 	return dos_crc(&(hdr->track), 0xb2, 0x30, 3); /* precomputed magic */
1110 }
1111 
1112 static inline ushort dos_data_crc(unsigned char *data)
1113 {
1114 	return dos_crc(data, 0xe2, 0x95 ,511); /* precomputed magic */
1115 }
1116 
1117 static inline unsigned char dos_decode_byte(ushort word)
1118 {
1119 	register ushort w2;
1120 	register unsigned char byte;
1121 	register unsigned char *dec = mfmdecode;
1122 
1123 	w2=word;
1124 	w2>>=8;
1125 	w2&=127;
1126 	byte = dec[w2];
1127 	byte <<= 4;
1128 	w2 = word & 127;
1129 	byte |= dec[w2];
1130 	return byte;
1131 }
1132 
1133 static unsigned long dos_decode(unsigned char *data, unsigned short *raw, int len)
1134 {
1135 	int i;
1136 
1137 	for (i = 0; i < len; i++)
1138 		*data++=dos_decode_byte(*raw++);
1139 	return ((ulong)raw);
1140 }
1141 
1142 #ifdef DEBUG
1143 static void dbg(unsigned long ptr)
1144 {
1145 	printk("raw data @%08lx: %08lx, %08lx ,%08lx, %08lx\n", ptr,
1146 	       ((ulong *)ptr)[0], ((ulong *)ptr)[1],
1147 	       ((ulong *)ptr)[2], ((ulong *)ptr)[3]);
1148 }
1149 #endif
1150 
1151 static int dos_read(int drive)
1152 {
1153 	unsigned long end;
1154 	unsigned long raw;
1155 	int scnt;
1156 	unsigned short crc,data_crc[2];
1157 	struct dos_header hdr;
1158 
1159 	drive&=3;
1160 	raw = (long) raw_buf;
1161 	end = raw + unit[drive].type->read_size;
1162 
1163 	for (scnt=0; scnt < unit[drive].dtype->sects * unit[drive].type->sect_mult; scnt++) {
1164 		do { /* search for the right sync of each sec-hdr */
1165 			if (!(raw = scan_sync (raw, end))) {
1166 				printk(KERN_INFO "dos_read: no hdr sync on "
1167 				       "track %d, unit %d for sector %d\n",
1168 				       unit[drive].track,drive,scnt);
1169 				return MFM_NOSYNC;
1170 			}
1171 #ifdef DEBUG
1172 			dbg(raw);
1173 #endif
1174 		} while (*((ushort *)raw)!=0x5554); /* loop usually only once done */
1175 		raw+=2; /* skip over headermark */
1176 		raw = dos_decode((unsigned char *)&hdr,(ushort *) raw,8);
1177 		crc = dos_hdr_crc(&hdr);
1178 
1179 #ifdef DEBUG
1180 		printk("(%3d,%d,%2d,%d) %x\n", hdr.track, hdr.side,
1181 		       hdr.sec, hdr.len_desc, hdr.crc);
1182 #endif
1183 
1184 		if (crc != hdr.crc) {
1185 			printk(KERN_INFO "dos_read: MFM_HEADER %04x,%04x\n",
1186 			       hdr.crc, crc);
1187 			return MFM_HEADER;
1188 		}
1189 		if (hdr.track != unit[drive].track/unit[drive].type->heads) {
1190 			printk(KERN_INFO "dos_read: MFM_TRACK %d, %d\n",
1191 			       hdr.track,
1192 			       unit[drive].track/unit[drive].type->heads);
1193 			return MFM_TRACK;
1194 		}
1195 
1196 		if (hdr.side != unit[drive].track%unit[drive].type->heads) {
1197 			printk(KERN_INFO "dos_read: MFM_SIDE %d, %d\n",
1198 			       hdr.side,
1199 			       unit[drive].track%unit[drive].type->heads);
1200 			return MFM_TRACK;
1201 		}
1202 
1203 		if (hdr.len_desc != 2) {
1204 			printk(KERN_INFO "dos_read: unknown sector len "
1205 			       "descriptor %d\n", hdr.len_desc);
1206 			return MFM_DATA;
1207 		}
1208 #ifdef DEBUG
1209 		printk("hdr accepted\n");
1210 #endif
1211 		if (!(raw = scan_sync (raw, end))) {
1212 			printk(KERN_INFO "dos_read: no data sync on track "
1213 			       "%d, unit %d for sector%d, disk sector %d\n",
1214 			       unit[drive].track, drive, scnt, hdr.sec);
1215 			return MFM_NOSYNC;
1216 		}
1217 #ifdef DEBUG
1218 		dbg(raw);
1219 #endif
1220 
1221 		if (*((ushort *)raw)!=0x5545) {
1222 			printk(KERN_INFO "dos_read: no data mark after "
1223 			       "sync (%d,%d,%d,%d) sc=%d\n",
1224 			       hdr.track,hdr.side,hdr.sec,hdr.len_desc,scnt);
1225 			return MFM_NOSYNC;
1226 		}
1227 
1228 		raw+=2;  /* skip data mark (included in checksum) */
1229 		raw = dos_decode((unsigned char *)(unit[drive].trackbuf + (hdr.sec - 1) * 512), (ushort *) raw, 512);
1230 		raw = dos_decode((unsigned char  *)data_crc,(ushort *) raw,4);
1231 		crc = dos_data_crc(unit[drive].trackbuf + (hdr.sec - 1) * 512);
1232 
1233 		if (crc != data_crc[0]) {
1234 			printk(KERN_INFO "dos_read: MFM_DATA (%d,%d,%d,%d) "
1235 			       "sc=%d, %x %x\n", hdr.track, hdr.side,
1236 			       hdr.sec, hdr.len_desc, scnt,data_crc[0], crc);
1237 			printk(KERN_INFO "data=(%lx,%lx,%lx,%lx,...)\n",
1238 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[0],
1239 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[1],
1240 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[2],
1241 			       ((ulong *)(unit[drive].trackbuf+(hdr.sec-1)*512))[3]);
1242 			return MFM_DATA;
1243 		}
1244 	}
1245 	return 0;
1246 }
1247 
1248 static inline ushort dos_encode_byte(unsigned char byte)
1249 {
1250 	register unsigned char *enc, b2, b1;
1251 	register ushort word;
1252 
1253 	enc=mfmencode;
1254 	b1=byte;
1255 	b2=b1>>4;
1256 	b1&=15;
1257 	word=enc[b2] <<8 | enc [b1];
1258 	return (word|((word&(256|64)) ? 0: 128));
1259 }
1260 
1261 static void dos_encode_block(ushort *dest, unsigned char *src, int len)
1262 {
1263 	int i;
1264 
1265 	for (i = 0; i < len; i++) {
1266 		*dest=dos_encode_byte(*src++);
1267 		*dest|=((dest[-1]&1)||(*dest&0x4000))? 0: 0x8000;
1268 		dest++;
1269 	}
1270 }
1271 
1272 static unsigned long *ms_putsec(int drive, unsigned long *raw, int cnt)
1273 {
1274 	static struct dos_header hdr={0,0,0,2,0,
1275 	  {78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78,78}};
1276 	int i;
1277 	static ushort crc[2]={0,0x4e4e};
1278 
1279 	drive&=3;
1280 /* id gap 1 */
1281 /* the MFM word before is always 9254 */
1282 	for(i=0;i<6;i++)
1283 		*raw++=0xaaaaaaaa;
1284 /* 3 sync + 1 headermark */
1285 	*raw++=0x44894489;
1286 	*raw++=0x44895554;
1287 
1288 /* fill in the variable parts of the header */
1289 	hdr.track=unit[drive].track/unit[drive].type->heads;
1290 	hdr.side=unit[drive].track%unit[drive].type->heads;
1291 	hdr.sec=cnt+1;
1292 	hdr.crc=dos_hdr_crc(&hdr);
1293 
1294 /* header (without "magic") and id gap 2*/
1295 	dos_encode_block((ushort *)raw,(unsigned char *) &hdr.track,28);
1296 	raw+=14;
1297 
1298 /*id gap 3 */
1299 	for(i=0;i<6;i++)
1300 		*raw++=0xaaaaaaaa;
1301 
1302 /* 3 syncs and 1 datamark */
1303 	*raw++=0x44894489;
1304 	*raw++=0x44895545;
1305 
1306 /* data */
1307 	dos_encode_block((ushort *)raw,
1308 			 (unsigned char *)unit[drive].trackbuf+cnt*512,512);
1309 	raw+=256;
1310 
1311 /*data crc + jd's special gap (long words :-/) */
1312 	crc[0]=dos_data_crc(unit[drive].trackbuf+cnt*512);
1313 	dos_encode_block((ushort *) raw,(unsigned char *)crc,4);
1314 	raw+=2;
1315 
1316 /* data gap */
1317 	for(i=0;i<38;i++)
1318 		*raw++=0x92549254;
1319 
1320 	return raw; /* wrote 652 MFM words */
1321 }
1322 
1323 static void dos_write(int disk)
1324 {
1325 	int cnt;
1326 	unsigned long raw = (unsigned long) raw_buf;
1327 	unsigned long *ptr=(unsigned long *)raw;
1328 
1329 	disk&=3;
1330 /* really gap4 + indexgap , but we write it first and round it up */
1331 	for (cnt=0;cnt<425;cnt++)
1332 		*ptr++=0x92549254;
1333 
1334 /* the following is just guessed */
1335 	if (unit[disk].type->sect_mult==2)  /* check for HD-Disks */
1336 		for(cnt=0;cnt<473;cnt++)
1337 			*ptr++=0x92549254;
1338 
1339 /* now the index marks...*/
1340 	for (cnt=0;cnt<20;cnt++)
1341 		*ptr++=0x92549254;
1342 	for (cnt=0;cnt<6;cnt++)
1343 		*ptr++=0xaaaaaaaa;
1344 	*ptr++=0x52245224;
1345 	*ptr++=0x52245552;
1346 	for (cnt=0;cnt<20;cnt++)
1347 		*ptr++=0x92549254;
1348 
1349 /* sectors */
1350 	for(cnt = 0; cnt < unit[disk].dtype->sects * unit[disk].type->sect_mult; cnt++)
1351 		ptr=ms_putsec(disk,ptr,cnt);
1352 
1353 	*(ushort *)ptr = 0xaaa8; /* MFM word before is always 0x9254 */
1354 }
1355 
1356 /*
1357  * Here comes the high level stuff (i.e. the filesystem interface)
1358  * and helper functions.
1359  * Normally this should be the only part that has to be adapted to
1360  * different kernel versions.
1361  */
1362 
1363 /* FIXME: this assumes the drive is still spinning -
1364  * which is only true if we complete writing a track within three seconds
1365  */
1366 static void flush_track_callback(struct timer_list *timer)
1367 {
1368 	unsigned long nr = ((unsigned long)timer -
1369 			       (unsigned long)&flush_track_timer[0]) /
1370 					sizeof(flush_track_timer[0]);
1371 
1372 	nr&=3;
1373 	writefromint = 1;
1374 	if (!try_fdc(nr)) {
1375 		/* we might block in an interrupt, so try again later */
1376 		flush_track_timer[nr].expires = jiffies + 1;
1377 		add_timer(flush_track_timer + nr);
1378 		return;
1379 	}
1380 	get_fdc(nr);
1381 	(*unit[nr].dtype->write_fkt)(nr);
1382 	if (!raw_write(nr)) {
1383 		printk (KERN_NOTICE "floppy disk write protected\n");
1384 		writefromint = 0;
1385 		writepending = 0;
1386 	}
1387 	rel_fdc();
1388 }
1389 
1390 static int non_int_flush_track (unsigned long nr)
1391 {
1392 	unsigned long flags;
1393 
1394 	nr&=3;
1395 	writefromint = 0;
1396 	del_timer(&post_write_timer);
1397 	get_fdc(nr);
1398 	if (!fd_motor_on(nr)) {
1399 		writepending = 0;
1400 		rel_fdc();
1401 		return 0;
1402 	}
1403 	local_irq_save(flags);
1404 	if (writepending != 2) {
1405 		local_irq_restore(flags);
1406 		(*unit[nr].dtype->write_fkt)(nr);
1407 		if (!raw_write(nr)) {
1408 			printk (KERN_NOTICE "floppy disk write protected "
1409 				"in write!\n");
1410 			writepending = 0;
1411 			return 0;
1412 		}
1413 		wait_event(wait_fd_block, block_flag != 2);
1414 	}
1415 	else {
1416 		local_irq_restore(flags);
1417 		ms_delay(2); /* 2 ms post_write delay */
1418 		post_write(nr);
1419 	}
1420 	rel_fdc();
1421 	return 1;
1422 }
1423 
1424 static int get_track(int drive, int track)
1425 {
1426 	int error, errcnt;
1427 
1428 	drive&=3;
1429 	if (unit[drive].track == track)
1430 		return 0;
1431 	get_fdc(drive);
1432 	if (!fd_motor_on(drive)) {
1433 		rel_fdc();
1434 		return -1;
1435 	}
1436 
1437 	if (unit[drive].dirty == 1) {
1438 		del_timer (flush_track_timer + drive);
1439 		non_int_flush_track (drive);
1440 	}
1441 	errcnt = 0;
1442 	while (errcnt < MAX_ERRORS) {
1443 		if (!fd_seek(drive, track))
1444 			return -1;
1445 		raw_read(drive);
1446 		error = (*unit[drive].dtype->read_fkt)(drive);
1447 		if (error == 0) {
1448 			rel_fdc();
1449 			return 0;
1450 		}
1451 		/* Read Error Handling: recalibrate and try again */
1452 		unit[drive].track = -1;
1453 		errcnt++;
1454 	}
1455 	rel_fdc();
1456 	return -1;
1457 }
1458 
1459 static blk_status_t amiflop_rw_cur_segment(struct amiga_floppy_struct *floppy,
1460 					   struct request *rq)
1461 {
1462 	int drive = floppy - unit;
1463 	unsigned int cnt, block, track, sector;
1464 	char *data;
1465 
1466 	for (cnt = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
1467 #ifdef DEBUG
1468 		printk("fd: sector %ld + %d requested for %s\n",
1469 		       blk_rq_pos(rq), cnt,
1470 		       (rq_data_dir(rq) == READ) ? "read" : "write");
1471 #endif
1472 		block = blk_rq_pos(rq) + cnt;
1473 		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
1474 		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
1475 		data = bio_data(rq->bio) + 512 * cnt;
1476 #ifdef DEBUG
1477 		printk("access to track %d, sector %d, with buffer at "
1478 		       "0x%08lx\n", track, sector, data);
1479 #endif
1480 
1481 		if (get_track(drive, track) == -1)
1482 			return BLK_STS_IOERR;
1483 
1484 		if (rq_data_dir(rq) == READ) {
1485 			memcpy(data, floppy->trackbuf + sector * 512, 512);
1486 		} else {
1487 			memcpy(floppy->trackbuf + sector * 512, data, 512);
1488 
1489 			/* keep the drive spinning while writes are scheduled */
1490 			if (!fd_motor_on(drive))
1491 				return BLK_STS_IOERR;
1492 			/*
1493 			 * setup a callback to write the track buffer
1494 			 * after a short (1 tick) delay.
1495 			 */
1496 			floppy->dirty = 1;
1497 		        /* reset the timer */
1498 			mod_timer (flush_track_timer + drive, jiffies + 1);
1499 		}
1500 	}
1501 
1502 	return BLK_STS_OK;
1503 }
1504 
1505 static blk_status_t amiflop_queue_rq(struct blk_mq_hw_ctx *hctx,
1506 				     const struct blk_mq_queue_data *bd)
1507 {
1508 	struct request *rq = bd->rq;
1509 	struct amiga_floppy_struct *floppy = rq->q->disk->private_data;
1510 	blk_status_t err;
1511 
1512 	if (!spin_trylock_irq(&amiflop_lock))
1513 		return BLK_STS_DEV_RESOURCE;
1514 
1515 	blk_mq_start_request(rq);
1516 
1517 	do {
1518 		err = amiflop_rw_cur_segment(floppy, rq);
1519 	} while (blk_update_request(rq, err, blk_rq_cur_bytes(rq)));
1520 	blk_mq_end_request(rq, err);
1521 
1522 	spin_unlock_irq(&amiflop_lock);
1523 	return BLK_STS_OK;
1524 }
1525 
1526 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1527 {
1528 	int drive = MINOR(bdev->bd_dev) & 3;
1529 
1530 	geo->heads = unit[drive].type->heads;
1531 	geo->sectors = unit[drive].dtype->sects * unit[drive].type->sect_mult;
1532 	geo->cylinders = unit[drive].type->tracks;
1533 	return 0;
1534 }
1535 
1536 static int fd_locked_ioctl(struct block_device *bdev, blk_mode_t mode,
1537 		    unsigned int cmd, unsigned long param)
1538 {
1539 	struct amiga_floppy_struct *p = bdev->bd_disk->private_data;
1540 	int drive = p - unit;
1541 	static struct floppy_struct getprm;
1542 	void __user *argp = (void __user *)param;
1543 
1544 	switch(cmd){
1545 	case FDFMTBEG:
1546 		get_fdc(drive);
1547 		if (fd_ref[drive] > 1) {
1548 			rel_fdc();
1549 			return -EBUSY;
1550 		}
1551 		if (fd_motor_on(drive) == 0) {
1552 			rel_fdc();
1553 			return -ENODEV;
1554 		}
1555 		if (fd_calibrate(drive) == 0) {
1556 			rel_fdc();
1557 			return -ENXIO;
1558 		}
1559 		floppy_off(drive);
1560 		rel_fdc();
1561 		break;
1562 	case FDFMTTRK:
1563 		if (param < p->type->tracks * p->type->heads)
1564 		{
1565 			get_fdc(drive);
1566 			if (fd_seek(drive,param) != 0){
1567 				memset(p->trackbuf, FD_FILL_BYTE,
1568 				       p->dtype->sects * p->type->sect_mult * 512);
1569 				non_int_flush_track(drive);
1570 			}
1571 			floppy_off(drive);
1572 			rel_fdc();
1573 		}
1574 		else
1575 			return -EINVAL;
1576 		break;
1577 	case FDFMTEND:
1578 		floppy_off(drive);
1579 		invalidate_bdev(bdev);
1580 		break;
1581 	case FDGETPRM:
1582 		memset((void *)&getprm, 0, sizeof (getprm));
1583 		getprm.track=p->type->tracks;
1584 		getprm.head=p->type->heads;
1585 		getprm.sect=p->dtype->sects * p->type->sect_mult;
1586 		getprm.size=p->blocks;
1587 		if (copy_to_user(argp, &getprm, sizeof(struct floppy_struct)))
1588 			return -EFAULT;
1589 		break;
1590 	case FDSETPRM:
1591 	case FDDEFPRM:
1592 		return -EINVAL;
1593 	case FDFLUSH: /* unconditionally, even if not needed */
1594 		del_timer (flush_track_timer + drive);
1595 		non_int_flush_track(drive);
1596 		break;
1597 #ifdef RAW_IOCTL
1598 	case IOCTL_RAW_TRACK:
1599 		if (copy_to_user(argp, raw_buf, p->type->read_size))
1600 			return -EFAULT;
1601 		else
1602 			return p->type->read_size;
1603 #endif
1604 	default:
1605 		return -ENOSYS;
1606 	}
1607 	return 0;
1608 }
1609 
1610 static int fd_ioctl(struct block_device *bdev, blk_mode_t mode,
1611 			     unsigned int cmd, unsigned long param)
1612 {
1613 	int ret;
1614 
1615 	mutex_lock(&amiflop_mutex);
1616 	ret = fd_locked_ioctl(bdev, mode, cmd, param);
1617 	mutex_unlock(&amiflop_mutex);
1618 
1619 	return ret;
1620 }
1621 
1622 static void fd_probe(int dev)
1623 {
1624 	unsigned long code;
1625 	int type;
1626 	int drive;
1627 
1628 	drive = dev & 3;
1629 	code = fd_get_drive_id(drive);
1630 
1631 	/* get drive type */
1632 	for (type = 0; type < num_dr_types; type++)
1633 		if (drive_types[type].code == code)
1634 			break;
1635 
1636 	if (type >= num_dr_types) {
1637 		printk(KERN_WARNING "fd_probe: unsupported drive type "
1638 		       "%08lx found\n", code);
1639 		unit[drive].type = &drive_types[num_dr_types-1]; /* FD_NODRIVE */
1640 		return;
1641 	}
1642 
1643 	unit[drive].type = drive_types + type;
1644 	unit[drive].track = -1;
1645 
1646 	unit[drive].disk = -1;
1647 	unit[drive].motor = 0;
1648 	unit[drive].busy = 0;
1649 	unit[drive].status = -1;
1650 }
1651 
1652 /*
1653  * floppy_open check for aliasing (/dev/fd0 can be the same as
1654  * /dev/PS0 etc), and disallows simultaneous access to the same
1655  * drive with different device numbers.
1656  */
1657 static int floppy_open(struct gendisk *disk, blk_mode_t mode)
1658 {
1659 	int drive = disk->first_minor & 3;
1660 	int system = (disk->first_minor & 4) >> 2;
1661 	int old_dev;
1662 	unsigned long flags;
1663 
1664 	mutex_lock(&amiflop_mutex);
1665 	old_dev = fd_device[drive];
1666 
1667 	if (fd_ref[drive] && old_dev != system) {
1668 		mutex_unlock(&amiflop_mutex);
1669 		return -EBUSY;
1670 	}
1671 
1672 	if (unit[drive].type->code == FD_NODRIVE) {
1673 		mutex_unlock(&amiflop_mutex);
1674 		return -ENXIO;
1675 	}
1676 	if (mode & (BLK_OPEN_READ | BLK_OPEN_WRITE)) {
1677 		disk_check_media_change(disk);
1678 		if (mode & BLK_OPEN_WRITE) {
1679 			int wrprot;
1680 
1681 			get_fdc(drive);
1682 			fd_select (drive);
1683 			wrprot = !(ciaa.pra & DSKPROT);
1684 			fd_deselect (drive);
1685 			rel_fdc();
1686 
1687 			if (wrprot) {
1688 				mutex_unlock(&amiflop_mutex);
1689 				return -EROFS;
1690 			}
1691 		}
1692 	}
1693 	local_irq_save(flags);
1694 	fd_ref[drive]++;
1695 	fd_device[drive] = system;
1696 	local_irq_restore(flags);
1697 
1698 	unit[drive].dtype=&data_types[system];
1699 	unit[drive].blocks=unit[drive].type->heads*unit[drive].type->tracks*
1700 		data_types[system].sects*unit[drive].type->sect_mult;
1701 	set_capacity(unit[drive].gendisk[system], unit[drive].blocks);
1702 
1703 	printk(KERN_INFO "fd%d: accessing %s-disk with %s-layout\n",drive,
1704 	       unit[drive].type->name, data_types[system].name);
1705 
1706 	mutex_unlock(&amiflop_mutex);
1707 	return 0;
1708 }
1709 
1710 static void floppy_release(struct gendisk *disk)
1711 {
1712 	struct amiga_floppy_struct *p = disk->private_data;
1713 	int drive = p - unit;
1714 
1715 	mutex_lock(&amiflop_mutex);
1716 	if (unit[drive].dirty == 1) {
1717 		del_timer (flush_track_timer + drive);
1718 		non_int_flush_track (drive);
1719 	}
1720 
1721 	if (!fd_ref[drive]--) {
1722 		printk(KERN_CRIT "floppy_release with fd_ref == 0");
1723 		fd_ref[drive] = 0;
1724 	}
1725 #ifdef MODULE
1726 	floppy_off (drive);
1727 #endif
1728 	mutex_unlock(&amiflop_mutex);
1729 }
1730 
1731 /*
1732  * check_events is never called from an interrupt, so we can relax a bit
1733  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
1734  * to the desired drive, but it will probably not survive the sleep if
1735  * several floppies are used at the same time: thus the loop.
1736  */
1737 static unsigned amiga_check_events(struct gendisk *disk, unsigned int clearing)
1738 {
1739 	struct amiga_floppy_struct *p = disk->private_data;
1740 	int drive = p - unit;
1741 	int changed;
1742 	static int first_time = 1;
1743 
1744 	if (first_time)
1745 		changed = first_time--;
1746 	else {
1747 		get_fdc(drive);
1748 		fd_select (drive);
1749 		changed = !(ciaa.pra & DSKCHANGE);
1750 		fd_deselect (drive);
1751 		rel_fdc();
1752 	}
1753 
1754 	if (changed) {
1755 		fd_probe(drive);
1756 		p->track = -1;
1757 		p->dirty = 0;
1758 		writepending = 0; /* if this was true before, too bad! */
1759 		writefromint = 0;
1760 		return DISK_EVENT_MEDIA_CHANGE;
1761 	}
1762 	return 0;
1763 }
1764 
1765 static const struct block_device_operations floppy_fops = {
1766 	.owner		= THIS_MODULE,
1767 	.open		= floppy_open,
1768 	.release	= floppy_release,
1769 	.ioctl		= fd_ioctl,
1770 	.getgeo		= fd_getgeo,
1771 	.check_events	= amiga_check_events,
1772 };
1773 
1774 static const struct blk_mq_ops amiflop_mq_ops = {
1775 	.queue_rq = amiflop_queue_rq,
1776 };
1777 
1778 static int fd_alloc_disk(int drive, int system)
1779 {
1780 	struct queue_limits lim = {
1781 		.features		= BLK_FEAT_ROTATIONAL,
1782 	};
1783 	struct gendisk *disk;
1784 	int err;
1785 
1786 	disk = blk_mq_alloc_disk(&unit[drive].tag_set, &lim, NULL);
1787 	if (IS_ERR(disk))
1788 		return PTR_ERR(disk);
1789 
1790 	disk->major = FLOPPY_MAJOR;
1791 	disk->first_minor = drive + system;
1792 	disk->minors = 1;
1793 	disk->fops = &floppy_fops;
1794 	disk->flags |= GENHD_FL_NO_PART;
1795 	disk->events = DISK_EVENT_MEDIA_CHANGE;
1796 	if (system)
1797 		sprintf(disk->disk_name, "fd%d_msdos", drive);
1798 	else
1799 		sprintf(disk->disk_name, "fd%d", drive);
1800 	disk->private_data = &unit[drive];
1801 	set_capacity(disk, 880 * 2);
1802 
1803 	unit[drive].gendisk[system] = disk;
1804 	err = add_disk(disk);
1805 	if (err)
1806 		put_disk(disk);
1807 	return err;
1808 }
1809 
1810 static int fd_alloc_drive(int drive)
1811 {
1812 	unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL);
1813 	if (!unit[drive].trackbuf)
1814 		goto out;
1815 
1816 	memset(&unit[drive].tag_set, 0, sizeof(unit[drive].tag_set));
1817 	unit[drive].tag_set.ops = &amiflop_mq_ops;
1818 	unit[drive].tag_set.nr_hw_queues = 1;
1819 	unit[drive].tag_set.nr_maps = 1;
1820 	unit[drive].tag_set.queue_depth = 2;
1821 	unit[drive].tag_set.numa_node = NUMA_NO_NODE;
1822 	unit[drive].tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
1823 	if (blk_mq_alloc_tag_set(&unit[drive].tag_set))
1824 		goto out_cleanup_trackbuf;
1825 
1826 	pr_cont(" fd%d", drive);
1827 
1828 	if (fd_alloc_disk(drive, 0) || fd_alloc_disk(drive, 1))
1829 		goto out_cleanup_tagset;
1830 	return 0;
1831 
1832 out_cleanup_tagset:
1833 	blk_mq_free_tag_set(&unit[drive].tag_set);
1834 out_cleanup_trackbuf:
1835 	kfree(unit[drive].trackbuf);
1836 out:
1837 	unit[drive].type->code = FD_NODRIVE;
1838 	return -ENOMEM;
1839 }
1840 
1841 static int __init fd_probe_drives(void)
1842 {
1843 	int drive,drives,nomem;
1844 
1845 	pr_info("FD: probing units\nfound");
1846 	drives=0;
1847 	nomem=0;
1848 	for(drive=0;drive<FD_MAX_UNITS;drive++) {
1849 		fd_probe(drive);
1850 		if (unit[drive].type->code == FD_NODRIVE)
1851 			continue;
1852 
1853 		if (fd_alloc_drive(drive) < 0) {
1854 			pr_cont(" no mem for fd%d", drive);
1855 			nomem = 1;
1856 			continue;
1857 		}
1858 		drives++;
1859 	}
1860 	if ((drives > 0) || (nomem == 0)) {
1861 		if (drives == 0)
1862 			pr_cont(" no drives");
1863 		pr_cont("\n");
1864 		return drives;
1865 	}
1866 	pr_cont("\n");
1867 	return -ENOMEM;
1868 }
1869 
1870 static int __init amiga_floppy_probe(struct platform_device *pdev)
1871 {
1872 	int i, ret;
1873 
1874 	if (register_blkdev(FLOPPY_MAJOR,"fd"))
1875 		return -EBUSY;
1876 
1877 	ret = -ENOMEM;
1878 	raw_buf = amiga_chip_alloc(RAW_BUF_SIZE, "Floppy");
1879 	if (!raw_buf) {
1880 		printk("fd: cannot get chip mem buffer\n");
1881 		goto out_blkdev;
1882 	}
1883 
1884 	ret = -EBUSY;
1885 	if (request_irq(IRQ_AMIGA_DSKBLK, fd_block_done, 0, "floppy_dma", NULL)) {
1886 		printk("fd: cannot get irq for dma\n");
1887 		goto out_irq;
1888 	}
1889 
1890 	if (request_irq(IRQ_AMIGA_CIAA_TB, ms_isr, 0, "floppy_timer", NULL)) {
1891 		printk("fd: cannot get irq for timer\n");
1892 		goto out_irq2;
1893 	}
1894 
1895 	ret = -ENODEV;
1896 	if (fd_probe_drives() < 1) /* No usable drives */
1897 		goto out_probe;
1898 
1899 	/* initialize variables */
1900 	timer_setup(&motor_on_timer, motor_on_callback, 0);
1901 	motor_on_timer.expires = 0;
1902 	for (i = 0; i < FD_MAX_UNITS; i++) {
1903 		timer_setup(&motor_off_timer[i], fd_motor_off, 0);
1904 		motor_off_timer[i].expires = 0;
1905 		timer_setup(&flush_track_timer[i], flush_track_callback, 0);
1906 		flush_track_timer[i].expires = 0;
1907 
1908 		unit[i].track = -1;
1909 	}
1910 
1911 	timer_setup(&post_write_timer, post_write_callback, 0);
1912 	post_write_timer.expires = 0;
1913 
1914 	for (i = 0; i < 128; i++)
1915 		mfmdecode[i]=255;
1916 	for (i = 0; i < 16; i++)
1917 		mfmdecode[mfmencode[i]]=i;
1918 
1919 	/* make sure that disk DMA is enabled */
1920 	custom.dmacon = DMAF_SETCLR | DMAF_DISK;
1921 
1922 	/* init ms timer */
1923 	ciaa.crb = 8; /* one-shot, stop */
1924 	return 0;
1925 
1926 out_probe:
1927 	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
1928 out_irq2:
1929 	free_irq(IRQ_AMIGA_DSKBLK, NULL);
1930 out_irq:
1931 	amiga_chip_free(raw_buf);
1932 out_blkdev:
1933 	unregister_blkdev(FLOPPY_MAJOR,"fd");
1934 	return ret;
1935 }
1936 
1937 static struct platform_driver amiga_floppy_driver = {
1938 	.driver   = {
1939 		.name	= "amiga-floppy",
1940 	},
1941 };
1942 
1943 static int __init amiga_floppy_init(void)
1944 {
1945 	return platform_driver_probe(&amiga_floppy_driver, amiga_floppy_probe);
1946 }
1947 
1948 module_init(amiga_floppy_init);
1949 
1950 #ifndef MODULE
1951 static int __init amiga_floppy_setup (char *str)
1952 {
1953 	int n;
1954 	if (!MACH_IS_AMIGA)
1955 		return 0;
1956 	if (!get_option(&str, &n))
1957 		return 0;
1958 	printk (KERN_INFO "amiflop: Setting default df0 to %x\n", n);
1959 	fd_def_df0 = n;
1960 	return 1;
1961 }
1962 
1963 __setup("floppy=", amiga_floppy_setup);
1964 #endif
1965 
1966 MODULE_ALIAS("platform:amiga-floppy");
1967