summaryrefslogtreecommitdiffstats
path: root/drivers/block/hd.c
blob: 30ec6b37424ef901dada825d3429478c0e57854a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 * This is the low-level hd interrupt support. It traverses the
 * request-list, using interrupts to jump between functions. As
 * all the functions are called within interrupts, we may not
 * sleep. Special care is recommended.
 *
 *  modified by Drew Eckhardt to check nr of hd's from the CMOS.
 *
 *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
 *  in the early extended-partition checks and added DM partitions
 *
 *  IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
 *  and general streamlining by Mark Lord.
 *
 *  Removed 99% of above. Use Mark's ide driver for those options.
 *  This is now a lightweight ST-506 driver. (Paul Gortmaker)
 *
 *  Modified 1995 Russell King for ARM processor.
 *
 *  Bugfix: max_sectors must be <= 255 or the wheels tend to come
 *  off in a hurry once you queue things up - Paul G. 02/2001
 */

/* Uncomment the following if you want verbose error reports. */
/* #define VERBOSE_ERRORS */

#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/genhd.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/blkpg.h>
#include <linux/ata.h>
#include <linux/hdreg.h>

#define HD_IRQ 14

#define REALLY_SLOW_IO
#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#ifdef __arm__
#undef  HD_IRQ
#endif
#include <asm/irq.h>
#ifdef __arm__
#define HD_IRQ IRQ_HARDDISK
#endif

/* Hd controller regster ports */

#define HD_DATA		0x1f0		/* _CTL when writing */
#define HD_ERROR	0x1f1		/* see err-bits */
#define HD_NSECTOR	0x1f2		/* nr of sectors to read/write */
#define HD_SECTOR	0x1f3		/* starting sector */
#define HD_LCYL		0x1f4		/* starting cylinder */
#define HD_HCYL		0x1f5		/* high byte of starting cyl */
#define HD_CURRENT	0x1f6		/* 101dhhhh , d=drive, hhhh=head */
#define HD_STATUS	0x1f7		/* see status-bits */
#define HD_FEATURE	HD_ERROR	/* same io address, read=error, write=feature */
#define HD_PRECOMP	HD_FEATURE	/* obsolete use of this port - predates IDE */
#define HD_COMMAND	HD_STATUS	/* same io address, read=status, write=cmd */

#define HD_CMD		0x3f6		/* used for resets */
#define HD_ALTSTATUS	0x3f6		/* same as HD_STATUS but doesn't clear irq */

/* Bits of HD_STATUS */
#define ERR_STAT		0x01
#define INDEX_STAT		0x02
#define ECC_STAT		0x04	/* Corrected error */
#define DRQ_STAT		0x08
#define SEEK_STAT		0x10
#define SERVICE_STAT		SEEK_STAT
#define WRERR_STAT		0x20
#define READY_STAT		0x40
#define BUSY_STAT		0x80

/* Bits for HD_ERROR */
#define MARK_ERR		0x01	/* Bad address mark */
#define TRK0_ERR		0x02	/* couldn't find track 0 */
#define ABRT_ERR		0x04	/* Command aborted */
#define MCR_ERR			0x08	/* media change request */
#define ID_ERR			0x10	/* ID field not found */
#define MC_ERR			0x20	/* media changed */
#define ECC_ERR			0x40	/* Uncorrectable ECC error */
#define BBD_ERR			0x80	/* pre-EIDE meaning:  block marked bad */
#define ICRC_ERR		0x80	/* new meaning:  CRC error during transfer */

static DEFINE_SPINLOCK(hd_lock);
static struct request_queue *hd_queue;
static struct request *hd_req;

#define TIMEOUT_VALUE	(6*HZ)
#define	HD_DELAY	0

#define MAX_ERRORS     16	/* Max read/write errors/sector */
#define RESET_FREQ      8	/* Reset controller every 8th retry */
#define RECAL_FREQ      4	/* Recalibrate every 4th retry */
#define MAX_HD		2

#define STAT_OK		(READY_STAT|SEEK_STAT)
#define OK_STATUS(s)	(((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)

static void recal_intr(void);
static void bad_rw_intr(void);

static int reset;
static int hd_error;

/*
 *  This struct defines the HD's and their types.
 */
struct hd_i_struct {
	unsigned int head, sect, cyl, wpcom, lzone, ctl;
	int unit;
	int recalibrate;
	int special_op;
};

#ifdef HD_TYPE
static struct hd_i_struct hd_info[] = { HD_TYPE };
static int NR_HD = ARRAY_SIZE(hd_info);
#else
static struct hd_i_struct hd_info[MAX_HD];
static int NR_HD;
#endif

static struct gendisk *hd_gendisk[MAX_HD];

static struct timer_list device_timer;

#define TIMEOUT_VALUE (6*HZ)

#define SET_TIMER							\
	do {								\
		mod_timer(&device_timer, jiffies + TIMEOUT_VALUE);	\
	} while (0)

static void (*do_hd)(void) = NULL;
#define SET_HANDLER(x) \
if ((do_hd = (x)) != NULL) \
	SET_TIMER; \
else \
	del_timer(&device_timer);


#if (HD_DELAY > 0)

#include <asm/i8253.h>

unsigned long last_req;

unsigned long read_timer(void)
{
	unsigned long t, flags;
	int i;

	raw_spin_lock_irqsave(&i8253_lock, flags);
	t = jiffies * 11932;
	outb_p(0, 0x43);
	i = inb_p(0x40);
	i |= inb(0x40) << 8;
	raw_spin_unlock_irqrestore(&i8253_lock, flags);
	return(t - i);
}
#endif

static void __init hd_setup(char *str, int *ints)
{
	int hdind = 0;

	if (ints[0] != 3)
		return;
	if (hd_info[0].head != 0)
		hdind = 1;
	hd_info[hdind].head = ints[2];
	hd_info[hdind].sect = ints[3];
	hd_info[hdind].cyl = ints[1];
	hd_info[hdind].wpcom = 0;
	hd_info[hdind].lzone = ints[1];
	hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
	NR_HD = hdind+1;
}

static bool hd_end_request(int err, unsigned int bytes)
{
	if (__blk_end_request(hd_req, err, bytes))
		return true;
	hd_req = NULL;
	return false;
}

static bool hd_end_request_cur(int err)
{
	return hd_end_request(err, blk_rq_cur_bytes(hd_req));
}

static void dump_status(const char *msg, unsigned int stat)
{
	char *name = "hd?";
	if (hd_req)
		name = hd_req->rq_disk->disk_name;

#ifdef VERBOSE_ERRORS
	printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
	if (stat & BUSY_STAT)	printk("Busy ");
	if (stat & READY_STAT)	printk("DriveReady ");
	if (stat & WRERR_STAT)	printk("WriteFault ");
	if (stat & SEEK_STAT)	printk("SeekComplete ");
	if (stat & DRQ_STAT)	printk("DataRequest ");
	if (stat & ECC_STAT)	printk("CorrectedError ");
	if (stat & INDEX_STAT)	printk("Index ");
	if (stat & ERR_STAT)	printk("Error ");
	printk("}\n");
	if ((stat & ERR_STAT) == 0) {
		hd_error = 0;
	} else {
		hd_error = inb(HD_ERROR);
		printk("%s: %s: error=0x%02x { ", name, msg, hd_error & 0xff);
		if (hd_error & BBD_ERR)		printk("BadSector ");
		if (hd_error & ECC_ERR)		printk("UncorrectableError ");
		if (hd_error & ID_ERR)		printk("SectorIdNotFound ");
		if (hd_error & ABRT_ERR)	printk("DriveStatusError ");
		if (hd_error & TRK0_ERR)	printk("TrackZeroNotFound ");
		if (hd_error & MARK_ERR)	printk("AddrMarkNotFound ");
		printk("}");
		if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
			printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
				inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
			if (hd_req)
				printk(", sector=%ld", blk_rq_pos(hd_req));
		}
		printk("\n");
	}
#else
	printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
	if ((stat & ERR_STAT) == 0) {
		hd_error = 0;
	} else {
		hd_error = inb(HD_ERROR);
		printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
	}
#endif
}

static void check_status(void)
{
	int i = inb_p(HD_STATUS);

	if (!OK_STATUS(i)) {
		dump_status("check_status", i);
		bad_rw_intr();
	}
}

static int controller_busy(void)
{
	int retries = 100000;
	unsigned char status;

	do {
		status = inb_p(HD_STATUS);
	} while ((status & BUSY_STAT) && --retries);
	return status;
}

static int status_ok(void)
{
	unsigned char status = inb_p(HD_STATUS);

	if (status & BUSY_STAT)
		return 1;	/* Ancient, but does it make sense??? */
	if (status & WRERR_STAT)
		return 0;
	if (!(status & READY_STAT))
		return 0;
	if (!(status & SEEK_STAT))
		return 0;
	return 1;
}

static int controller_ready(unsigned int drive, unsigned int head)
{
	int retry = 100;

	do {
		if (controller_busy() & BUSY_STAT)
			return 0;
		outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
		if (status_ok())
			return 1;
	} while (--retry);
	return 0;
}

static void hd_out(struct hd_i_struct *disk,
		   unsigned int nsect,
		   unsigned int sect,
		   unsigned int head,
		   unsigned int cyl,
		   unsigned int cmd,
		   void (*intr_addr)(void))
{
	unsigned short port;

#if (HD_DELAY > 0)
	while (read_timer() - last_req < HD_DELAY)
		/* nothing */;
#endif
	if (reset)
		return;
	if (!controller_ready(disk->unit, head)) {
		reset = 1;
		return;
	}
	SET_HANDLER(intr_addr);
	outb_p(disk->ctl, HD_CMD);
	port = HD_DATA;
	outb_p(disk->wpcom >> 2, ++port);
	outb_p(nsect, ++port);
	outb_p(sect, ++port);
	outb_p(cyl, ++port);
	outb_p(cyl >> 8, ++port);
	outb_p(0xA0 | (disk->unit << 4) | head, ++port);
	outb_p(cmd, ++port);
}

static void hd_request (void);

static int drive_busy(void)
{
	unsigned int i;
	unsigned char c;

	for (i = 0; i < 500000 ; i++) {
		c = inb_p(HD_STATUS);
		if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
			return 0;
	}
	dump_status("reset timed out", c);
	return 1;
}

static void reset_controller(void)
{
	int	i;

	outb_p(4, HD_CMD);
	for (i = 0; i < 1000; i++) barrier();
	outb_p(hd_info[0].ctl & 0x0f, HD_CMD);
	for (i = 0; i < 1000; i++) barrier();
	if (drive_busy())
		printk("hd: controller still busy\n");
	else if ((hd_error = inb(HD_ERROR)) != 1)
		printk("hd: controller reset failed: %02x\n", hd_error);
}

static void reset_hd(void)
{
	static int i;

repeat:
	if (reset) {
		reset = 0;
		i = -1;
		reset_controller();
	} else {
		check_status();
		if (reset)
			goto repeat;
	}
	if (++i < NR_HD) {
		struct hd_i_struct *disk = &hd_info[i];
		disk->special_op = disk->recalibrate = 1;
		hd_out(disk, disk->sect, disk->sect, disk->head-1,
			disk->cyl, ATA_CMD_INIT_DEV_PARAMS, &reset_hd);
		if (reset)
			goto repeat;
	} else
		hd_request();
}

/*
 * Ok, don't know what to do with the unexpected interrupts: on some machines
 * doing a reset and a retry seems to result in an eternal loop. Right now I
 * ignore it, and just set the timeout.
 *
 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
 * drive enters "idle", "standby", or "sleep" mode, so if the status looks
 * "good", we just ignore the interrupt completely.
 */
static void unexpected_hd_interrupt(void)
{
	unsigned int stat = inb_p(HD_STATUS);

	if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
		dump_status("unexpected interrupt", stat);
		SET_TIMER;
	}
}

/*
 * bad_rw_intr() now tries to be a bit smarter and does things
 * according to the error returned by the controller.
 * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
 */
static void bad_rw_intr(void)
{
	struct request *req = hd_req;

	if (req != NULL) {
		struct hd_i_struct *disk = req->rq_disk->private_data;
		if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
			hd_end_request_cur(-EIO);
			disk->special_op = disk->recalibrate = 1;
		} else if (req->errors % RESET_FREQ == 0)
			reset = 1;
		else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0)
			disk->special_op = disk->recalibrate = 1;
		/* Otherwise just retry */
	}
}

static inline int wait_DRQ(void)
{
	int retries;
	int stat;

	for (retries = 0; retries < 100000; retries++) {
		stat = inb_p(HD_STATUS);
		if (stat & DRQ_STAT)
			return 0;
	}
	dump_status("wait_DRQ", stat);
	return -1;
}

static void read_intr(void)
{
	struct request *req;
	int i, retries = 100000;

	do {
		i = (unsigned) inb_p(HD_STATUS);
		if (i & BUSY_STAT)
			continue;
		if (!OK_STATUS(i))
			break;
		if (i & DRQ_STAT)
			goto ok_to_read;
	} while (--retries > 0);
	dump_status("read_intr", i);
	bad_rw_intr();
	hd_request();
	return;

ok_to_read:
	req = hd_req;
	insw(HD_DATA, req->buffer, 256);
#ifdef DEBUG
	printk("%s: read: sector %ld, remaining = %u, buffer=%p\n",
	       req->rq_disk->disk_name, blk_rq_pos(req) + 1,
	       blk_rq_sectors(req) - 1, req->buffer+512);
#endif
	if (hd_end_request(0, 512)) {
		SET_HANDLER(&read_intr);
		return;
	}

	(void) inb_p(HD_STATUS);
#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	hd_request();
}

static void write_intr(void)
{
	struct request *req = hd_req;
	int i;
	int retries = 100000;

	do {
		i = (unsigned) inb_p(HD_STATUS);
		if (i & BUSY_STAT)
			continue;
		if (!OK_STATUS(i))
			break;
		if ((blk_rq_sectors(req) <= 1) || (i & DRQ_STAT))
			goto ok_to_write;
	} while (--retries > 0);
	dump_status("write_intr", i);
	bad_rw_intr();
	hd_request();
	return;

ok_to_write:
	if (hd_end_request(0, 512)) {
		SET_HANDLER(&write_intr);
		outsw(HD_DATA, req->buffer, 256);
		return;
	}

#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	hd_request();
}

static void recal_intr(void)
{
	check_status();
#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	hd_request();
}

/*
 * This is another of the error-routines I don't know what to do with. The
 * best idea seems to just set reset, and start all over again.
 */
static void hd_times_out(unsigned long dummy)
{
	char *name;

	do_hd = NULL;

	if (!hd_req)
		return;

	spin_lock_irq(hd_queue->queue_lock);
	reset = 1;
	name = hd_req->rq_disk->disk_name;
	printk("%s: timeout\n", name);
	if (++hd_req->errors >= MAX_ERRORS) {
#ifdef DEBUG
		printk("%s: too many errors\n", name);
#endif
		hd_end_request_cur(-EIO);
	}
	hd_request();
	spin_unlock_irq(hd_queue->queue_lock);
}

static int do_special_op(struct hd_i_struct *disk, struct request *req)
{
	if (disk->recalibrate) {
		disk->recalibrate = 0;
		hd_out(disk, disk->sect, 0, 0, 0, ATA_CMD_RESTORE, &recal_intr);
		return reset;
	}
	if (disk->head > 16) {
		printk("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
		hd_end_request_cur(-EIO);
	}
	disk->special_op = 0;
	return 1;
}

/*
 * The driver enables interrupts as much as possible.  In order to do this,
 * (a) the device-interrupt is disabled before entering hd_request(),
 * and (b) the timeout-interrupt is disabled before the sti().
 *
 * Interrupts are still masked (by default) whenever we are exchanging
 * data/cmds with a drive, because some drives seem to have very poor
 * tolerance for latency during I/O. The IDE driver has support to unmask
 * interrupts for non-broken hardware, so use that driver if required.
 */
static void hd_request(void)
{
	unsigned int block, nsect, sec, track, head, cyl;
	struct hd_i_struct *disk;
	struct request *req;

	if (do_hd)
		return;
repeat:
	del_timer(&device_timer);

	if (!hd_req) {
		hd_req = blk_fetch_request(hd_queue);
		if (!hd_req) {
			do_hd = NULL;
			return;
		}
	}
	req = hd_req;

	if (reset) {
		reset_hd();
		return;
	}
	disk = req->rq_disk->private_data;
	block = blk_rq_pos(req);
	nsect = blk_rq_sectors(req);
	if (block >= get_capacity(req->rq_disk) ||
	    ((block+nsect) > get_capacity(req->rq_disk))) {
		printk("%s: bad access: block=%d, count=%d\n",
			req->rq_disk->disk_name, block, nsect);
		hd_end_request_cur(-EIO);
		goto repeat;
	}

	if (disk->special_op) {
		if (do_special_op(disk, req))
			goto repeat;
		return;
	}
	sec   = block % disk->sect + 1;
	track = block / disk->sect;
	head  = track % disk->head;
	cyl   = track / disk->head;
#ifdef DEBUG
	printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
		req->rq_disk->disk_name,
		req_data_dir(req) == READ ? "read" : "writ",
		cyl, head, sec, nsect, req->buffer);
#endif
	if (req->cmd_type == REQ_TYPE_FS) {
		switch (rq_data_dir(req)) {
		case READ:
			hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
				&read_intr);
			if (reset)
				goto repeat;
			break;
		case WRITE:
			hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
				&write_intr);
			if (reset)
				goto repeat;
			if (wait_DRQ()) {
				bad_rw_intr();
				goto repeat;
			}
			outsw(HD_DATA, req->buffer, 256);
			break;
		default:
			printk("unknown hd-command\n");
			hd_end_request_cur(-EIO);
			break;
		}
	}
}

static void do_hd_request(struct request_queue *q)
{
	hd_request();
}

static int hd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct hd_i_struct *disk = bdev->bd_disk->private_data;

	geo->heads = disk->head;
	geo->sectors = disk->sect;
	geo->cylinders = disk->cyl;
	return 0;
}

/*
 * Releasing a block device means we sync() it, so that it can safely
 * be forgotten about...
 */

static irqreturn_t hd_interrupt(int irq, void *dev_id)
{
	void (*handler)(void) = do_hd;

	spin_lock(hd_queue->queue_lock);

	do_hd = NULL;
	del_timer(&device_timer);
	if (!handler)
		handler = unexpected_hd_interrupt;
	handler();

	spin_unlock(hd_queue->queue_lock);

	return IRQ_HANDLED;
}

static const struct block_device_operations hd_fops = {
	.getgeo =	hd_getgeo,
};

/*
 * This is the hard disk IRQ description. The IRQF_DISABLED in sa_flags
 * means we run the IRQ-handler with interrupts disabled:  this is bad for
 * interrupt latency, but anything else has led to problems on some
 * machines.
 *
 * We enable interrupts in some of the routines after making sure it's
 * safe.
 */

static int __init hd_init(void)
{
	int drive;

	if (register_blkdev(HD_MAJOR, "hd"))
		return -1;

	hd_queue = blk_init_queue(do_hd_request, &hd_lock);
	if (!hd_queue) {
		unregister_blkdev(HD_MAJOR, "hd");
		return -ENOMEM;
	}

	blk_queue_max_hw_sectors(hd_queue, 255);
	init_timer(&device_timer);
	device_timer.function = hd_times_out;
	blk_queue_logical_block_size(hd_queue, 512);

	if (!NR_HD) {
		/*
		 * We don't know anything about the drive.  This means
		 * that you *MUST* specify the drive parameters to the
		 * kernel yourself.
		 *
		 * If we were on an i386, we used to read this info from
		 * the BIOS or CMOS.  This doesn't work all that well,
		 * since this assumes that this is a primary or secondary
		 * drive, and if we're using this legacy driver, it's
		 * probably an auxilliary controller added to recover
		 * legacy data off an ST-506 drive.  Either way, it's
		 * definitely safest to have the user explicitly specify
		 * the information.
		 */
		printk("hd: no drives specified - use hd=cyl,head,sectors"
			" on kernel command line\n");
		goto out;
	}

	for (drive = 0 ; drive < NR_HD ; drive++) {
		struct gendisk *disk = alloc_disk(64);
		struct hd_i_struct *p = &hd_info[drive];
		if (!disk)
			goto Enomem;
		disk->major = HD_MAJOR;
		disk->first_minor = drive << 6;
		disk->fops = &hd_fops;
		sprintf(disk->disk_name, "hd%c", 'a'+drive);
		disk->private_data = p;
		set_capacity(disk, p->head * p->sect * p->cyl);
		disk->queue = hd_queue;
		p->unit = drive;
		hd_gendisk[drive] = disk;
		printk("%s: %luMB, CHS=%d/%d/%d\n",
			disk->disk_name, (unsigned long)get_capacity(disk)/2048,
			p->cyl, p->head, p->sect);
	}

	if (request_irq(HD_IRQ, hd_interrupt, IRQF_DISABLED, "hd", NULL)) {
		printk("hd: unable to get IRQ%d for the hard disk driver\n",
			HD_IRQ);
		goto out1;
	}
	if (!request_region(HD_DATA, 8, "hd")) {
		printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
		goto out2;
	}
	if (!request_region(HD_CMD, 1, "hd(cmd)")) {
		printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
		goto out3;
	}

	/* Let them fly */
	for (drive = 0; drive < NR_HD; drive++)
		add_disk(hd_gendisk[drive]);

	return 0;

out3:
	release_region(HD_DATA, 8);
out2:
	free_irq(HD_IRQ, NULL);
out1:
	for (drive = 0; drive < NR_HD; drive++)
		put_disk(hd_gendisk[drive]);
	NR_HD = 0;
out:
	del_timer(&device_timer);
	unregister_blkdev(HD_MAJOR, "hd");
	blk_cleanup_queue(hd_queue);
	return -1;
Enomem:
	while (drive--)
		put_disk(hd_gendisk[drive]);
	goto out;
}

static int __init parse_hd_setup(char *line)
{
	int ints[6];

	(void) get_options(line, ARRAY_SIZE(ints), ints);
	hd_setup(NULL, ints);

	return 1;
}
__setup("hd=", parse_hd_setup);

late_initcall(hd_init);