aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/ide-scsi.c
blob: 7d3d03f989144cd84011295551c530bf54b91a59 (plain) (blame)
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
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
/*
 * Copyright (C) 1996-1999  Gadi Oxman <gadio@netvision.net.il>
 * Copyright (C) 2004-2005  Bartlomiej Zolnierkiewicz
 */

/*
 * Emulation of a SCSI host adapter for IDE ATAPI devices.
 *
 * With this driver, one can use the Linux SCSI drivers instead of the
 * native IDE ATAPI drivers.
 *
 * Ver 0.1   Dec  3 96   Initial version.
 * Ver 0.2   Jan 26 97   Fixed bug in cleanup_module() and added emulation
 *                        of MODE_SENSE_6/MODE_SELECT_6 for cdroms. Thanks
 *                        to Janos Farkas for pointing this out.
 *                       Avoid using bitfields in structures for m68k.
 *                       Added Scatter/Gather and DMA support.
 * Ver 0.4   Dec  7 97   Add support for ATAPI PD/CD drives.
 *                       Use variable timeout for each command.
 * Ver 0.5   Jan  2 98   Fix previous PD/CD support.
 *                       Allow disabling of SCSI-6 to SCSI-10 transformation.
 * Ver 0.6   Jan 27 98   Allow disabling of SCSI command translation layer
 *                        for access through /dev/sg.
 *                       Fix MODE_SENSE_6/MODE_SELECT_6/INQUIRY translation.
 * Ver 0.7   Dec 04 98   Ignore commands where lun != 0 to avoid multiple
 *                        detection of devices with CONFIG_SCSI_MULTI_LUN
 * Ver 0.8   Feb 05 99   Optical media need translation too. Reverse 0.7.
 * Ver 0.9   Jul 04 99   Fix a bug in SG_SET_TRANSFORM.
 * Ver 0.91  Jun 10 02   Fix "off by one" error in transforms
 * Ver 0.92  Dec 31 02   Implement new SCSI mid level API
 */

#define IDESCSI_VERSION "0.92"

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ide.h>
#include <linux/scatterlist.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/bitops.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/sg.h>

#define IDESCSI_DEBUG_LOG		0

#if IDESCSI_DEBUG_LOG
#define debug_log(fmt, args...) \
	printk(KERN_INFO "ide-scsi: " fmt, ## args)
#else
#define debug_log(fmt, args...) do {} while (0)
#endif

/*
 *	SCSI command transformation layer
 */
#define IDESCSI_SG_TRANSFORM		1	/* /dev/sg transformation */

/*
 *	Log flags
 */
#define IDESCSI_LOG_CMD			0	/* Log SCSI commands */

typedef struct ide_scsi_obj {
	ide_drive_t		*drive;
	ide_driver_t		*driver;
	struct gendisk		*disk;
	struct Scsi_Host	*host;

	unsigned long transform;		/* SCSI cmd translation layer */
	unsigned long log;			/* log flags */
} idescsi_scsi_t;

static DEFINE_MUTEX(idescsi_ref_mutex);
/* Set by module param to skip cd */
static int idescsi_nocd;

#define ide_scsi_g(disk) \
	container_of((disk)->private_data, struct ide_scsi_obj, driver)

static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk)
{
	struct ide_scsi_obj *scsi = NULL;

	mutex_lock(&idescsi_ref_mutex);
	scsi = ide_scsi_g(disk);
	if (scsi) {
		if (ide_device_get(scsi->drive))
			scsi = NULL;
		else
			scsi_host_get(scsi->host);
	}
	mutex_unlock(&idescsi_ref_mutex);
	return scsi;
}

static void ide_scsi_put(struct ide_scsi_obj *scsi)
{
	ide_drive_t *drive = scsi->drive;

	mutex_lock(&idescsi_ref_mutex);
	scsi_host_put(scsi->host);
	ide_device_put(drive);
	mutex_unlock(&idescsi_ref_mutex);
}

static inline idescsi_scsi_t *scsihost_to_idescsi(struct Scsi_Host *host)
{
	return (idescsi_scsi_t*) (&host[1]);
}

static inline idescsi_scsi_t *drive_to_idescsi(ide_drive_t *ide_drive)
{
	return scsihost_to_idescsi(ide_drive->driver_data);
}

static void ide_scsi_hex_dump(u8 *data, int len)
{
	print_hex_dump(KERN_CONT, "", DUMP_PREFIX_NONE, 16, 1, data, len, 0);
}

static int idescsi_end_request(ide_drive_t *, int, int);

static void ide_scsi_callback(ide_drive_t *drive, int dsc)
{
	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
	struct ide_atapi_pc *pc = drive->pc;

	if (pc->flags & PC_FLAG_TIMEDOUT)
		debug_log("%s: got timed out packet %lu at %lu\n", __func__,
			  pc->scsi_cmd->serial_number, jiffies);
		/* end this request now - scsi should retry it*/
	else if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk(KERN_INFO "Packet command completed, %d bytes"
				 " transferred\n", pc->xferred);

	idescsi_end_request(drive, 1, 0);
}

static int idescsi_check_condition(ide_drive_t *drive,
		struct request *failed_cmd)
{
	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
	struct ide_atapi_pc   *pc;
	struct request *rq;
	u8             *buf;

	/* stuff a sense request in front of our current request */
	pc = kzalloc(sizeof(struct ide_atapi_pc), GFP_ATOMIC);
	rq = blk_get_request(drive->queue, READ, GFP_ATOMIC);
	buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_ATOMIC);
	if (!pc || !rq || !buf) {
		kfree(buf);
		if (rq)
			blk_put_request(rq);
		kfree(pc);
		return -ENOMEM;
	}
	rq->special = (char *) pc;
	pc->rq = rq;
	pc->buf = buf;
	pc->c[0] = REQUEST_SENSE;
	pc->c[4] = pc->req_xfer = pc->buf_size = SCSI_SENSE_BUFFERSIZE;
	rq->cmd_type = REQ_TYPE_SENSE;
	rq->cmd_flags |= REQ_PREEMPT;
	pc->timeout = jiffies + WAIT_READY;
	/* NOTE! Save the failed packet command in "rq->buffer" */
	rq->buffer = (void *) failed_cmd->special;
	pc->scsi_cmd = ((struct ide_atapi_pc *) failed_cmd->special)->scsi_cmd;
	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
		printk ("ide-scsi: %s: queue cmd = ", drive->name);
		ide_scsi_hex_dump(pc->c, 6);
	}
	rq->rq_disk = scsi->disk;
	rq->ref_count++;
	memcpy(rq->cmd, pc->c, 12);
	ide_do_drive_cmd(drive, rq);
	return 0;
}

static ide_startstop_t
idescsi_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
{
	ide_hwif_t *hwif = drive->hwif;

	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
		/* force an abort */
		hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);

	rq->errors++;

	idescsi_end_request(drive, 0, 0);

	return ide_stopped;
}

static int idescsi_end_request (ide_drive_t *drive, int uptodate, int nrsecs)
{
	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
	struct request *rq = HWGROUP(drive)->rq;
	struct ide_atapi_pc *pc = (struct ide_atapi_pc *) rq->special;
	int log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
	struct Scsi_Host *host;
	int errors = rq->errors;
	unsigned long flags;

	if (!blk_special_request(rq) && !blk_sense_request(rq)) {
		ide_end_request(drive, uptodate, nrsecs);
		return 0;
	}
	ide_end_drive_cmd (drive, 0, 0);
	if (blk_sense_request(rq)) {
		struct ide_atapi_pc *opc = (struct ide_atapi_pc *) rq->buffer;
		if (log) {
			printk ("ide-scsi: %s: wrap up check %lu, rst = ", drive->name, opc->scsi_cmd->serial_number);
			ide_scsi_hex_dump(pc->buf, 16);
		}
		memcpy((void *) opc->scsi_cmd->sense_buffer, pc->buf,
			SCSI_SENSE_BUFFERSIZE);
		kfree(pc->buf);
		kfree(pc);
		blk_put_request(rq);
		pc = opc;
		rq = pc->rq;
		pc->scsi_cmd->result = (CHECK_CONDITION << 1) |
				(((pc->flags & PC_FLAG_TIMEDOUT) ?
				  DID_TIME_OUT :
				  DID_OK) << 16);
	} else if (pc->flags & PC_FLAG_TIMEDOUT) {
		if (log)
			printk (KERN_WARNING "ide-scsi: %s: timed out for %lu\n",
					drive->name, pc->scsi_cmd->serial_number);
		pc->scsi_cmd->result = DID_TIME_OUT << 16;
	} else if (errors >= ERROR_MAX) {
		pc->scsi_cmd->result = DID_ERROR << 16;
		if (log)
			printk ("ide-scsi: %s: I/O error for %lu\n", drive->name, pc->scsi_cmd->serial_number);
	} else if (errors) {
		if (log)
			printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
		if (!idescsi_check_condition(drive, rq))
			/* we started a request sense, so we'll be back, exit for now */
			return 0;
		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
	} else {
		pc->scsi_cmd->result = DID_OK << 16;
	}
	host = pc->scsi_cmd->device->host;
	spin_lock_irqsave(host->host_lock, flags);
	pc->done(pc->scsi_cmd);
	spin_unlock_irqrestore(host->host_lock, flags);
	kfree(pc);
	blk_put_request(rq);
	drive->pc = NULL;
	return 0;
}

static inline int idescsi_set_direction(struct ide_atapi_pc *pc)
{
	switch (pc->c[0]) {
		case READ_6: case READ_10: case READ_12:
			pc->flags &= ~PC_FLAG_WRITING;
			return 0;
		case WRITE_6: case WRITE_10: case WRITE_12:
			pc->flags |= PC_FLAG_WRITING;
			return 0;
		default:
			return 1;
	}
}

static int idescsi_map_sg(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
	ide_hwif_t *hwif = drive->hwif;
	struct scatterlist *sg, *scsi_sg;
	int segments;

	if (!pc->req_xfer || pc->req_xfer % 1024)
		return 1;

	if (idescsi_set_direction(pc))
		return 1;

	sg = hwif->sg_table;
	scsi_sg = scsi_sglist(pc->scsi_cmd);
	segments = scsi_sg_count(pc->scsi_cmd);

	if (segments > hwif->sg_max_nents)
		return 1;

	hwif->sg_nents = segments;
	memcpy(sg, scsi_sg, sizeof(*sg) * segments);

	return 0;
}

static ide_startstop_t idescsi_issue_pc(ide_drive_t *drive,
		struct ide_atapi_pc *pc)
{
	/* Set the current packet command */
	drive->pc = pc;

	return ide_issue_pc(drive, ide_scsi_get_timeout(pc), ide_scsi_expiry);
}

/*
 *	idescsi_do_request is our request handling function.
 */
static ide_startstop_t idescsi_do_request (ide_drive_t *drive, struct request *rq, sector_t block)
{
	debug_log("dev: %s, cmd: %x, errors: %d\n", rq->rq_disk->disk_name,
		  rq->cmd[0], rq->errors);
	debug_log("sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",
		  rq->sector, rq->nr_sectors, rq->current_nr_sectors);

	if (blk_sense_request(rq) || blk_special_request(rq)) {
		struct ide_atapi_pc *pc = (struct ide_atapi_pc *)rq->special;

		if (drive->using_dma && !idescsi_map_sg(drive, pc))
			pc->flags |= PC_FLAG_DMA_OK;

		return idescsi_issue_pc(drive, pc);
	}
	blk_dump_rq_flags(rq, "ide-scsi: unsup command");
	idescsi_end_request (drive, 0, 0);
	return ide_stopped;
}

#ifdef CONFIG_IDE_PROC_FS
#define ide_scsi_devset_get(name, field) \
static int get_##name(ide_drive_t *drive) \
{ \
	idescsi_scsi_t *scsi = drive_to_idescsi(drive); \
	return scsi->field; \
}

#define ide_scsi_devset_set(name, field) \
static int set_##name(ide_drive_t *drive, int arg) \
{ \
	idescsi_scsi_t *scsi = drive_to_idescsi(drive); \
	scsi->field = arg; \
	return 0; \
}

#define ide_scsi_devset_rw_field(_name, _field) \
ide_scsi_devset_get(_name, _field); \
ide_scsi_devset_set(_name, _field); \
IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name);

ide_devset_rw_field(bios_cyl, bios_cyl);
ide_devset_rw_field(bios_head, bios_head);
ide_devset_rw_field(bios_sect, bios_sect);

ide_scsi_devset_rw_field(transform, transform);
ide_scsi_devset_rw_field(log, log);

static const struct ide_proc_devset idescsi_settings[] = {
	IDE_PROC_DEVSET(bios_cyl,  0, 1023),
	IDE_PROC_DEVSET(bios_head, 0,  255),
	IDE_PROC_DEVSET(bios_sect, 0,	63),
	IDE_PROC_DEVSET(log,	   0,	 1),
	IDE_PROC_DEVSET(transform, 0,	 3),
	{ 0 },
};
#endif

/*
 *	Driver initialization.
 */
static void idescsi_setup (ide_drive_t *drive, idescsi_scsi_t *scsi)
{
	if ((drive->id[ATA_ID_CONFIG] & 0x0060) == 0x20)
		set_bit(IDE_AFLAG_DRQ_INTERRUPT, &drive->atapi_flags);
	clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
#if IDESCSI_DEBUG_LOG
	set_bit(IDESCSI_LOG_CMD, &scsi->log);
#endif /* IDESCSI_DEBUG_LOG */

	drive->pc_callback	 = ide_scsi_callback;
	drive->pc_update_buffers = NULL;
	drive->pc_io_buffers	 = ide_io_buffers;

	ide_proc_register_driver(drive, scsi->driver);
}

static void ide_scsi_remove(ide_drive_t *drive)
{
	struct Scsi_Host *scsihost = drive->driver_data;
	struct ide_scsi_obj *scsi = scsihost_to_idescsi(scsihost);
	struct gendisk *g = scsi->disk;

	scsi_remove_host(scsihost);
	ide_proc_unregister_driver(drive, scsi->driver);

	ide_unregister_region(g);

	drive->driver_data = NULL;
	g->private_data = NULL;
	put_disk(g);

	ide_scsi_put(scsi);

	drive->scsi = 0;
}

static int ide_scsi_probe(ide_drive_t *);

#ifdef CONFIG_IDE_PROC_FS
static ide_proc_entry_t idescsi_proc[] = {
	{ "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
	{ NULL, 0, NULL, NULL }
};
#endif

static ide_driver_t idescsi_driver = {
	.gen_driver = {
		.owner		= THIS_MODULE,
		.name		= "ide-scsi",
		.bus		= &ide_bus_type,
	},
	.probe			= ide_scsi_probe,
	.remove			= ide_scsi_remove,
	.version		= IDESCSI_VERSION,
	.media			= ide_scsi,
	.do_request		= idescsi_do_request,
	.end_request		= idescsi_end_request,
	.error                  = idescsi_atapi_error,
#ifdef CONFIG_IDE_PROC_FS
	.proc			= idescsi_proc,
	.settings		= idescsi_settings,
#endif
};

static int idescsi_ide_open(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_scsi_obj *scsi;

	if (!(scsi = ide_scsi_get(disk)))
		return -ENXIO;

	return 0;
}

static int idescsi_ide_release(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_scsi_obj *scsi = ide_scsi_g(disk);

	ide_scsi_put(scsi);

	return 0;
}

static int idescsi_ide_ioctl(struct inode *inode, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct block_device *bdev = inode->i_bdev;
	struct ide_scsi_obj *scsi = ide_scsi_g(bdev->bd_disk);
	return generic_ide_ioctl(scsi->drive, file, bdev, cmd, arg);
}

static struct block_device_operations idescsi_ops = {
	.owner		= THIS_MODULE,
	.open		= idescsi_ide_open,
	.release	= idescsi_ide_release,
	.ioctl		= idescsi_ide_ioctl,
};

static int idescsi_slave_configure(struct scsi_device * sdp)
{
	/* Configure detected device */
	sdp->use_10_for_rw = 1;
	sdp->use_10_for_ms = 1;
	scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, sdp->host->cmd_per_lun);
	return 0;
}

static const char *idescsi_info (struct Scsi_Host *host)
{
	return "SCSI host adapter emulation for IDE ATAPI devices";
}

static int idescsi_ioctl (struct scsi_device *dev, int cmd, void __user *arg)
{
	idescsi_scsi_t *scsi = scsihost_to_idescsi(dev->host);

	if (cmd == SG_SET_TRANSFORM) {
		if (arg)
			set_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
		else
			clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
		return 0;
	} else if (cmd == SG_GET_TRANSFORM)
		return put_user(test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform), (int __user *) arg);
	return -EINVAL;
}

static int idescsi_queue (struct scsi_cmnd *cmd,
		void (*done)(struct scsi_cmnd *))
{
	struct Scsi_Host *host = cmd->device->host;
	idescsi_scsi_t *scsi = scsihost_to_idescsi(host);
	ide_drive_t *drive = scsi->drive;
	struct request *rq = NULL;
	struct ide_atapi_pc *pc = NULL;
	int write = cmd->sc_data_direction == DMA_TO_DEVICE;

	if (!drive) {
		scmd_printk (KERN_ERR, cmd, "drive not present\n");
		goto abort;
	}
	scsi = drive_to_idescsi(drive);
	pc = kmalloc(sizeof(struct ide_atapi_pc), GFP_ATOMIC);
	rq = blk_get_request(drive->queue, write, GFP_ATOMIC);
	if (rq == NULL || pc == NULL) {
		printk (KERN_ERR "ide-scsi: %s: out of memory\n", drive->name);
		goto abort;
	}

	memset (pc->c, 0, 12);
	pc->flags = 0;
	if (cmd->sc_data_direction == DMA_TO_DEVICE)
		pc->flags |= PC_FLAG_WRITING;
	pc->rq = rq;
	memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
	pc->buf = NULL;
	pc->sg = scsi_sglist(cmd);
	pc->sg_cnt = scsi_sg_count(cmd);
	pc->b_count = 0;
	pc->req_xfer = pc->buf_size = scsi_bufflen(cmd);
	pc->scsi_cmd = cmd;
	pc->done = done;
	pc->timeout = jiffies + cmd->request->timeout;

	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
		printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
		ide_scsi_hex_dump(cmd->cmnd, cmd->cmd_len);
		if (memcmp(pc->c, cmd->cmnd, cmd->cmd_len)) {
			printk ("ide-scsi: %s: que %lu, tsl = ", drive->name, cmd->serial_number);
			ide_scsi_hex_dump(pc->c, 12);
		}
	}

	rq->special = (char *) pc;
	rq->cmd_type = REQ_TYPE_SPECIAL;
	spin_unlock_irq(host->host_lock);
	rq->ref_count++;
	memcpy(rq->cmd, pc->c, 12);
	blk_execute_rq_nowait(drive->queue, scsi->disk, rq, 0, NULL);
	spin_lock_irq(host->host_lock);
	return 0;
abort:
	kfree (pc);
	if (rq)
		blk_put_request(rq);
	cmd->result = DID_ERROR << 16;
	done(cmd);
	return 0;
}

static int idescsi_eh_abort (struct scsi_cmnd *cmd)
{
	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
	ide_drive_t    *drive = scsi->drive;
	int		busy;
	int             ret   = FAILED;

	struct ide_atapi_pc *pc;

	/* In idescsi_eh_abort we try to gently pry our command from the ide subsystem */

	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk (KERN_WARNING "ide-scsi: abort called for %lu\n", cmd->serial_number);

	if (!drive) {
		printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_abort\n");
		WARN_ON(1);
		goto no_drive;
	}

	/* First give it some more time, how much is "right" is hard to say :-( */

	busy = ide_wait_not_busy(HWIF(drive), 100);	/* FIXME - uses mdelay which causes latency? */
	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk (KERN_WARNING "ide-scsi: drive did%s become ready\n", busy?" not":"");

	spin_lock_irq(&ide_lock);

	/* If there is no pc running we're done (our interrupt took care of it) */
	pc = drive->pc;
	if (pc == NULL) {
		ret = SUCCESS;
		goto ide_unlock;
	}

	/* It's somewhere in flight. Does ide subsystem agree? */
	if (pc->scsi_cmd->serial_number == cmd->serial_number && !busy &&
	    elv_queue_empty(drive->queue) && HWGROUP(drive)->rq != pc->rq) {
		/*
		 * FIXME - not sure this condition can ever occur
		 */
		printk (KERN_ERR "ide-scsi: cmd aborted!\n");

		if (blk_sense_request(pc->rq))
			kfree(pc->buf);
		/* we need to call blk_put_request twice. */
		blk_put_request(pc->rq);
		blk_put_request(pc->rq);
		kfree(pc);
		drive->pc = NULL;

		ret = SUCCESS;
	}

ide_unlock:
	spin_unlock_irq(&ide_lock);
no_drive:
	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk (KERN_WARNING "ide-scsi: abort returns %s\n", ret == SUCCESS?"success":"failed");

	return ret;
}

static int idescsi_eh_reset (struct scsi_cmnd *cmd)
{
	struct request *req;
	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
	ide_drive_t    *drive = scsi->drive;
	int             ready = 0;
	int             ret   = SUCCESS;

	struct ide_atapi_pc *pc;

	/* In idescsi_eh_reset we forcefully remove the command from the ide subsystem and reset the device. */

	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk (KERN_WARNING "ide-scsi: reset called for %lu\n", cmd->serial_number);

	if (!drive) {
		printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_reset\n");
		WARN_ON(1);
		return FAILED;
	}

	spin_lock_irq(cmd->device->host->host_lock);
	spin_lock(&ide_lock);

	pc = drive->pc;

	if (pc == NULL || (req = pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
		printk (KERN_WARNING "ide-scsi: No active request in idescsi_eh_reset\n");
		spin_unlock(&ide_lock);
		spin_unlock_irq(cmd->device->host->host_lock);
		return FAILED;
	}

	/* kill current request */
	if (__blk_end_request(req, -EIO, 0))
		BUG();
	if (blk_sense_request(req))
		kfree(pc->buf);
	kfree(pc);
	drive->pc = NULL;
	blk_put_request(req);

	/* now nuke the drive queue */
	while ((req = elv_next_request(drive->queue))) {
		if (__blk_end_request(req, -EIO, 0))
			BUG();
	}

	HWGROUP(drive)->rq = NULL;
	HWGROUP(drive)->handler = NULL;
	HWGROUP(drive)->busy = 1;		/* will set this to zero when ide reset finished */
	spin_unlock(&ide_lock);

	ide_do_reset(drive);

	/* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */

	do {
		spin_unlock_irq(cmd->device->host->host_lock);
		msleep(50);
		spin_lock_irq(cmd->device->host->host_lock);
	} while ( HWGROUP(drive)->handler );

	ready = drive_is_ready(drive);
	HWGROUP(drive)->busy--;
	if (!ready) {
		printk (KERN_ERR "ide-scsi: reset failed!\n");
		ret = FAILED;
	}

	spin_unlock_irq(cmd->device->host->host_lock);
	return ret;
}

static int idescsi_bios(struct scsi_device *sdev, struct block_device *bdev,
		sector_t capacity, int *parm)
{
	idescsi_scsi_t *idescsi = scsihost_to_idescsi(sdev->host);
	ide_drive_t *drive = idescsi->drive;

	if (drive->bios_cyl && drive->bios_head && drive->bios_sect) {
		parm[0] = drive->bios_head;
		parm[1] = drive->bios_sect;
		parm[2] = drive->bios_cyl;
	}
	return 0;
}

static struct scsi_host_template idescsi_template = {
	.module			= THIS_MODULE,
	.name			= "idescsi",
	.info			= idescsi_info,
	.slave_configure        = idescsi_slave_configure,
	.ioctl			= idescsi_ioctl,
	.queuecommand		= idescsi_queue,
	.eh_abort_handler	= idescsi_eh_abort,
	.eh_host_reset_handler  = idescsi_eh_reset,
	.bios_param		= idescsi_bios,
	.can_queue		= 40,
	.this_id		= -1,
	.sg_tablesize		= 256,
	.cmd_per_lun		= 5,
	.max_sectors		= 128,
	.use_clustering		= DISABLE_CLUSTERING,
	.emulated		= 1,
	.proc_name		= "ide-scsi",
};

static int ide_scsi_probe(ide_drive_t *drive)
{
	idescsi_scsi_t *idescsi;
	struct Scsi_Host *host;
	struct gendisk *g;
	static int warned;
	int err = -ENOMEM;
	u16 last_lun;

	if (!warned && drive->media == ide_cdrom) {
		printk(KERN_WARNING "ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX as device\n");
		warned = 1;
	}

	if (idescsi_nocd && drive->media == ide_cdrom)
		return -ENODEV;

	if (!strstr("ide-scsi", drive->driver_req) ||
	    drive->media == ide_disk ||
	    !(host = scsi_host_alloc(&idescsi_template,sizeof(idescsi_scsi_t))))
		return -ENODEV;

	drive->scsi = 1;

	g = alloc_disk(1 << PARTN_BITS);
	if (!g)
		goto out_host_put;

	ide_init_disk(g, drive);

	host->max_id = 1;

	last_lun = drive->id[ATA_ID_LAST_LUN];
	if (last_lun)
		debug_log("%s: last_lun=%u\n", drive->name, last_lun);

	if ((last_lun & 7) != 7)
		host->max_lun = (last_lun & 7) + 1;
	else
		host->max_lun = 1;

	drive->driver_data = host;
	idescsi = scsihost_to_idescsi(host);
	idescsi->drive = drive;
	idescsi->driver = &idescsi_driver;
	idescsi->host = host;
	idescsi->disk = g;
	g->private_data = &idescsi->driver;
	err = 0;
	idescsi_setup(drive, idescsi);
	g->fops = &idescsi_ops;
	ide_register_region(g);
	err = scsi_add_host(host, &drive->gendev);
	if (!err) {
		scsi_scan_host(host);
		return 0;
	}
	/* fall through on error */
	ide_unregister_region(g);
	ide_proc_unregister_driver(drive, &idescsi_driver);

	put_disk(g);
out_host_put:
	drive->scsi = 0;
	scsi_host_put(host);
	return err;
}

static int __init init_idescsi_module(void)
{
	return driver_register(&idescsi_driver.gen_driver);
}

static void __exit exit_idescsi_module(void)
{
	driver_unregister(&idescsi_driver.gen_driver);
}

module_param(idescsi_nocd, int, 0600);
MODULE_PARM_DESC(idescsi_nocd, "Disable handling of CD-ROMs so they may be driven by ide-cd");
module_init(init_idescsi_module);
module_exit(exit_idescsi_module);
MODULE_LICENSE("GPL");