summaryrefslogtreecommitdiff
path: root/drivers/scsi/libsas/sas_ata.c
blob: db9238f2ecb8b7596dda9c2d4132000af0910bd7 (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
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
/*
 * Support for SATA devices on Serial Attached SCSI (SAS) controllers
 *
 * Copyright (C) 2006 IBM Corporation
 *
 * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <linux/scatterlist.h>
#include <linux/slab.h>

#include <scsi/sas_ata.h>
#include "sas_internal.h"
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include "../scsi_sas_internal.h"
#include "../scsi_transport_api.h"
#include <scsi/scsi_eh.h>

static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
{
	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */

	/* transport error */
	if (ts->resp == SAS_TASK_UNDELIVERED)
		return AC_ERR_ATA_BUS;

	/* ts->resp == SAS_TASK_COMPLETE */
	/* task delivered, what happened afterwards? */
	switch (ts->stat) {
		case SAS_DEV_NO_RESPONSE:
			return AC_ERR_TIMEOUT;

		case SAS_INTERRUPTED:
		case SAS_PHY_DOWN:
		case SAS_NAK_R_ERR:
			return AC_ERR_ATA_BUS;


		case SAS_DATA_UNDERRUN:
			/*
			 * Some programs that use the taskfile interface
			 * (smartctl in particular) can cause underrun
			 * problems.  Ignore these errors, perhaps at our
			 * peril.
			 */
			return 0;

		case SAS_DATA_OVERRUN:
		case SAS_QUEUE_FULL:
		case SAS_DEVICE_UNKNOWN:
		case SAS_SG_ERR:
			return AC_ERR_INVALID;

		case SAS_OPEN_TO:
		case SAS_OPEN_REJECT:
			SAS_DPRINTK("%s: Saw error %d.  What to do?\n",
				    __func__, ts->stat);
			return AC_ERR_OTHER;

		case SAM_STAT_CHECK_CONDITION:
		case SAS_ABORTED_TASK:
			return AC_ERR_DEV;

		case SAS_PROTO_RESPONSE:
			/* This means the ending_fis has the error
			 * value; return 0 here to collect it */
			return 0;
		default:
			return 0;
	}
}

static void sas_ata_task_done(struct sas_task *task)
{
	struct ata_queued_cmd *qc = task->uldd_task;
	struct domain_device *dev;
	struct task_status_struct *stat = &task->task_status;
	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
	struct sas_ha_struct *sas_ha;
	enum ata_completion_errors ac;
	unsigned long flags;
	struct ata_link *link;

	if (!qc)
		goto qc_already_gone;

	dev = qc->ap->private_data;
	sas_ha = dev->port->ha;
	link = &dev->sata_dev.ap->link;

	spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
	if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_STAT_GOOD ||
	    ((stat->stat == SAM_STAT_CHECK_CONDITION &&
	      dev->sata_dev.command_set == ATAPI_COMMAND_SET))) {
		ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);

		if (!link->sactive) {
			qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
		} else {
			link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.tf.command);
			if (unlikely(link->eh_info.err_mask))
				qc->flags |= ATA_QCFLAG_FAILED;
		}

		dev->sata_dev.sstatus = resp->sstatus;
		dev->sata_dev.serror = resp->serror;
		dev->sata_dev.scontrol = resp->scontrol;
	} else {
		ac = sas_to_ata_err(stat);
		if (ac) {
			SAS_DPRINTK("%s: SAS error %x\n", __func__,
				    stat->stat);
			/* We saw a SAS error. Send a vague error. */
			if (!link->sactive) {
				qc->err_mask = ac;
			} else {
				link->eh_info.err_mask |= AC_ERR_DEV;
				qc->flags |= ATA_QCFLAG_FAILED;
			}

			dev->sata_dev.tf.feature = 0x04; /* status err */
			dev->sata_dev.tf.command = ATA_ERR;
		}
	}

	qc->lldd_task = NULL;
	if (qc->scsicmd)
		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
	ata_qc_complete(qc);
	spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);

	/*
	 * If the sas_task has an ata qc, a scsi_cmnd and the aborted
	 * flag is set, then we must have come in via the libsas EH
	 * functions.  When we exit this function, we need to put the
	 * scsi_cmnd on the list of finished errors.  The ata_qc_complete
	 * call cleans up the libata side of things but we're protected
	 * from the scsi_cmnd going away because the scsi_cmnd is owned
	 * by the EH, making libata's call to scsi_done a NOP.
	 */
	spin_lock_irqsave(&task->task_state_lock, flags);
	if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
		scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
	spin_unlock_irqrestore(&task->task_state_lock, flags);

qc_already_gone:
	list_del_init(&task->list);
	sas_free_task(task);
}

static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
{
	int res;
	struct sas_task *task;
	struct domain_device *dev = qc->ap->private_data;
	struct sas_ha_struct *sas_ha = dev->port->ha;
	struct Scsi_Host *host = sas_ha->core.shost;
	struct sas_internal *i = to_sas_internal(host->transportt);
	struct scatterlist *sg;
	unsigned int xfer = 0;
	unsigned int si;

	/* If the device fell off, no sense in issuing commands */
	if (dev->gone)
		return AC_ERR_SYSTEM;

	task = sas_alloc_task(GFP_ATOMIC);
	if (!task)
		return AC_ERR_SYSTEM;
	task->dev = dev;
	task->task_proto = SAS_PROTOCOL_STP;
	task->task_done = sas_ata_task_done;

	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
	    qc->tf.command == ATA_CMD_FPDMA_READ) {
		/* Need to zero out the tag libata assigned us */
		qc->tf.nsect = 0;
	}

	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
	task->uldd_task = qc;
	if (ata_is_atapi(qc->tf.protocol)) {
		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
		task->total_xfer_len = qc->nbytes;
		task->num_scatter = qc->n_elem;
	} else {
		for_each_sg(qc->sg, sg, qc->n_elem, si)
			xfer += sg->length;

		task->total_xfer_len = xfer;
		task->num_scatter = si;
	}

	task->data_dir = qc->dma_dir;
	task->scatter = qc->sg;
	task->ata_task.retry_count = 1;
	task->task_state_flags = SAS_TASK_STATE_PENDING;
	qc->lldd_task = task;

	switch (qc->tf.protocol) {
	case ATA_PROT_NCQ:
		task->ata_task.use_ncq = 1;
		/* fall through */
	case ATAPI_PROT_DMA:
	case ATA_PROT_DMA:
		task->ata_task.dma_xfer = 1;
		break;
	}

	if (qc->scsicmd)
		ASSIGN_SAS_TASK(qc->scsicmd, task);

	if (sas_ha->lldd_max_execute_num < 2)
		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
	else
		res = sas_queue_up(task);

	/* Examine */
	if (res) {
		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);

		if (qc->scsicmd)
			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
		sas_free_task(task);
		return AC_ERR_SYSTEM;
	}

	return 0;
}

static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
{
	struct domain_device *dev = qc->ap->private_data;

	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
	return true;
}

static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
			       unsigned long deadline)
{
	struct ata_port *ap = link->ap;
	struct domain_device *dev = ap->private_data;
	struct sas_internal *i =
		to_sas_internal(dev->port->ha->core.shost->transportt);
	int res = TMF_RESP_FUNC_FAILED;
	int ret = 0;

	if (i->dft->lldd_I_T_nexus_reset)
		res = i->dft->lldd_I_T_nexus_reset(dev);

	if (res != TMF_RESP_FUNC_COMPLETE) {
		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
		ret = -EAGAIN;
	}

	switch (dev->sata_dev.command_set) {
		case ATA_COMMAND_SET:
			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
			*class = ATA_DEV_ATA;
			break;
		case ATAPI_COMMAND_SET:
			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
			*class = ATA_DEV_ATAPI;
			break;
		default:
			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
				    __func__,
				    dev->sata_dev.command_set);
			*class = ATA_DEV_UNKNOWN;
			break;
	}

	ap->cbl = ATA_CBL_SATA;
	return ret;
}

static int sas_ata_soft_reset(struct ata_link *link, unsigned int *class,
			       unsigned long deadline)
{
	struct ata_port *ap = link->ap;
	struct domain_device *dev = ap->private_data;
	struct sas_internal *i =
		to_sas_internal(dev->port->ha->core.shost->transportt);
	int res = TMF_RESP_FUNC_FAILED;
	int ret = 0;

	if (i->dft->lldd_ata_soft_reset)
		res = i->dft->lldd_ata_soft_reset(dev);

	if (res != TMF_RESP_FUNC_COMPLETE) {
		SAS_DPRINTK("%s: Unable to soft reset\n", __func__);
		ret = -EAGAIN;
	}

	switch (dev->sata_dev.command_set) {
	case ATA_COMMAND_SET:
		SAS_DPRINTK("%s: Found ATA device.\n", __func__);
		*class = ATA_DEV_ATA;
		break;
	case ATAPI_COMMAND_SET:
		SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
		*class = ATA_DEV_ATAPI;
		break;
	default:
		SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
			    __func__, dev->sata_dev.command_set);
		*class = ATA_DEV_UNKNOWN;
		break;
	}

	ap->cbl = ATA_CBL_SATA;
	return ret;
}

static void sas_ata_post_internal(struct ata_queued_cmd *qc)
{
	if (qc->flags & ATA_QCFLAG_FAILED)
		qc->err_mask |= AC_ERR_OTHER;

	if (qc->err_mask) {
		/*
		 * Find the sas_task and kill it.  By this point,
		 * libata has decided to kill the qc, so we needn't
		 * bother with sas_ata_task_done.  But we still
		 * ought to abort the task.
		 */
		struct sas_task *task = qc->lldd_task;
		unsigned long flags;

		qc->lldd_task = NULL;
		if (task) {
			/* Should this be a AT(API) device reset? */
			spin_lock_irqsave(&task->task_state_lock, flags);
			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
			spin_unlock_irqrestore(&task->task_state_lock, flags);

			task->uldd_task = NULL;
			__sas_task_abort(task);
		}
	}
}

static struct ata_port_operations sas_sata_ops = {
	.prereset		= ata_std_prereset,
	.softreset		= sas_ata_soft_reset,
	.hardreset		= sas_ata_hard_reset,
	.postreset		= ata_std_postreset,
	.error_handler		= ata_std_error_handler,
	.post_internal_cmd	= sas_ata_post_internal,
	.qc_defer               = ata_std_qc_defer,
	.qc_prep		= ata_noop_qc_prep,
	.qc_issue		= sas_ata_qc_issue,
	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
	.port_start		= ata_sas_port_start,
	.port_stop		= ata_sas_port_stop,
};

static struct ata_port_info sata_port_info = {
	.flags = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
	.pio_mask = ATA_PIO4,
	.mwdma_mask = ATA_MWDMA2,
	.udma_mask = ATA_UDMA6,
	.port_ops = &sas_sata_ops
};

int sas_ata_init_host_and_port(struct domain_device *found_dev,
			       struct scsi_target *starget)
{
	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
	struct ata_port *ap;

	ata_host_init(&found_dev->sata_dev.ata_host,
		      ha->dev,
		      sata_port_info.flags,
		      &sas_sata_ops);
	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
				&sata_port_info,
				shost);
	if (!ap) {
		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
		return -ENODEV;
	}

	ap->private_data = found_dev;
	ap->cbl = ATA_CBL_SATA;
	ap->scsi_host = shost;
	found_dev->sata_dev.ap = ap;

	return 0;
}

void sas_ata_task_abort(struct sas_task *task)
{
	struct ata_queued_cmd *qc = task->uldd_task;
	struct completion *waiting;

	/* Bounce SCSI-initiated commands to the SCSI EH */
	if (qc->scsicmd) {
		struct request_queue *q = qc->scsicmd->device->request_queue;
		unsigned long flags;

		spin_lock_irqsave(q->queue_lock, flags);
		blk_abort_request(qc->scsicmd->request);
		spin_unlock_irqrestore(q->queue_lock, flags);
		scsi_schedule_eh(qc->scsicmd->device->host);
		return;
	}

	/* Internal command, fake a timeout and complete. */
	qc->flags &= ~ATA_QCFLAG_ACTIVE;
	qc->flags |= ATA_QCFLAG_FAILED;
	qc->err_mask |= AC_ERR_TIMEOUT;
	waiting = qc->private_data;
	complete(waiting);
}

static void sas_task_timedout(unsigned long _task)
{
	struct sas_task *task = (void *) _task;
	unsigned long flags;

	spin_lock_irqsave(&task->task_state_lock, flags);
	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
	spin_unlock_irqrestore(&task->task_state_lock, flags);

	complete(&task->completion);
}

static void sas_disc_task_done(struct sas_task *task)
{
	if (!del_timer(&task->timer))
		return;
	complete(&task->completion);
}

#define SAS_DEV_TIMEOUT 10

/**
 * sas_execute_task -- Basic task processing for discovery
 * @task: the task to be executed
 * @buffer: pointer to buffer to do I/O
 * @size: size of @buffer
 * @dma_dir: DMA direction.  DMA_xxx
 */
static int sas_execute_task(struct sas_task *task, void *buffer, int size,
			    enum dma_data_direction dma_dir)
{
	int res = 0;
	struct scatterlist *scatter = NULL;
	struct task_status_struct *ts = &task->task_status;
	int num_scatter = 0;
	int retries = 0;
	struct sas_internal *i =
		to_sas_internal(task->dev->port->ha->core.shost->transportt);

	if (dma_dir != DMA_NONE) {
		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
		if (!scatter)
			goto out;

		sg_init_one(scatter, buffer, size);
		num_scatter = 1;
	}

	task->task_proto = task->dev->tproto;
	task->scatter = scatter;
	task->num_scatter = num_scatter;
	task->total_xfer_len = size;
	task->data_dir = dma_dir;
	task->task_done = sas_disc_task_done;
	if (dma_dir != DMA_NONE &&
	    sas_protocol_ata(task->task_proto)) {
		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
					       task->scatter,
					       task->num_scatter,
					       task->data_dir);
	}

	for (retries = 0; retries < 5; retries++) {
		task->task_state_flags = SAS_TASK_STATE_PENDING;
		init_completion(&task->completion);

		task->timer.data = (unsigned long) task;
		task->timer.function = sas_task_timedout;
		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
		add_timer(&task->timer);

		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
		if (res) {
			del_timer(&task->timer);
			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
				    res);
			goto ex_err;
		}
		wait_for_completion(&task->completion);
		res = -ECOMM;
		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
			int res2;
			SAS_DPRINTK("task aborted, flags:0x%x\n",
				    task->task_state_flags);
			res2 = i->dft->lldd_abort_task(task);
			SAS_DPRINTK("came back from abort task\n");
			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
				if (res2 == TMF_RESP_FUNC_COMPLETE)
					continue; /* Retry the task */
				else
					goto ex_err;
			}
		}
		if (task->task_status.stat == SAM_STAT_BUSY ||
			   task->task_status.stat == SAM_STAT_TASK_SET_FULL ||
			   task->task_status.stat == SAS_QUEUE_FULL) {
			SAS_DPRINTK("task: q busy, sleeping...\n");
			schedule_timeout_interruptible(HZ);
		} else if (task->task_status.stat == SAM_STAT_CHECK_CONDITION) {
			struct scsi_sense_hdr shdr;

			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
						  &shdr)) {
				SAS_DPRINTK("couldn't normalize sense\n");
				continue;
			}
			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
			    (shdr.sense_key == 2 && shdr.asc == 4 &&
			     shdr.ascq == 1)) {
				SAS_DPRINTK("device %016llx LUN: %016llx "
					    "powering up or not ready yet, "
					    "sleeping...\n",
					    SAS_ADDR(task->dev->sas_addr),
					    SAS_ADDR(task->ssp_task.LUN));

				schedule_timeout_interruptible(5*HZ);
			} else if (shdr.sense_key == 1) {
				res = 0;
				break;
			} else if (shdr.sense_key == 5) {
				break;
			} else {
				SAS_DPRINTK("dev %016llx LUN: %016llx "
					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
					    "\n",
					    SAS_ADDR(task->dev->sas_addr),
					    SAS_ADDR(task->ssp_task.LUN),
					    shdr.sense_key,
					    shdr.asc, shdr.ascq);
			}
		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
			   task->task_status.stat != SAM_STAT_GOOD) {
			SAS_DPRINTK("task finished with resp:0x%x, "
				    "stat:0x%x\n",
				    task->task_status.resp,
				    task->task_status.stat);
			goto ex_err;
		} else {
			res = 0;
			break;
		}
	}
ex_err:
	if (dma_dir != DMA_NONE) {
		if (sas_protocol_ata(task->task_proto))
			dma_unmap_sg(task->dev->port->ha->dev,
				     task->scatter, task->num_scatter,
				     task->data_dir);
		kfree(scatter);
	}
out:
	return res;
}

/* ---------- SATA ---------- */

static void sas_get_ata_command_set(struct domain_device *dev)
{
	struct dev_to_host_fis *fis =
		(struct dev_to_host_fis *) dev->frame_rcvd;

	if ((fis->sector_count == 1 && /* ATA */
	     fis->lbal         == 1 &&
	     fis->lbam         == 0 &&
	     fis->lbah         == 0 &&
	     fis->device       == 0)
	    ||
	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
	     fis->lbal         == 0 &&
	     fis->lbam         == 0xCE &&
	     fis->lbah         == 0xAA &&
	     (fis->device & ~0x10) == 0))

		dev->sata_dev.command_set = ATA_COMMAND_SET;

	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
		  fis->lbal             == 1 &&
		  fis->byte_count_low   == 0x14 &&
		  fis->byte_count_high  == 0xEB &&
		  (fis->device & ~0x10) == 0))

		dev->sata_dev.command_set = ATAPI_COMMAND_SET;

	else if ((fis->sector_count == 1 && /* SEMB */
		  fis->lbal         == 1 &&
		  fis->lbam         == 0x3C &&
		  fis->lbah         == 0xC3 &&
		  fis->device       == 0)
		||
		 (fis->interrupt_reason == 1 &&	/* SATA PM */
		  fis->lbal             == 1 &&
		  fis->byte_count_low   == 0x69 &&
		  fis->byte_count_high  == 0x96 &&
		  (fis->device & ~0x10) == 0))

		/* Treat it as a superset? */
		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
}

/**
 * sas_issue_ata_cmd -- Basic SATA command processing for discovery
 * @dev: the device to send the command to
 * @command: the command register
 * @features: the features register
 * @buffer: pointer to buffer to do I/O
 * @size: size of @buffer
 * @dma_dir: DMA direction.  DMA_xxx
 */
static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
			     u8 features, void *buffer, int size,
			     enum dma_data_direction dma_dir)
{
	int res = 0;
	struct sas_task *task;
	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
		&dev->frame_rcvd[0];

	res = -ENOMEM;
	task = sas_alloc_task(GFP_KERNEL);
	if (!task)
		goto out;

	task->dev = dev;

	task->ata_task.fis.fis_type = 0x27;
	task->ata_task.fis.command = command;
	task->ata_task.fis.features = features;
	task->ata_task.fis.device = d2h_fis->device;
	task->ata_task.retry_count = 1;

	res = sas_execute_task(task, buffer, size, dma_dir);

	sas_free_task(task);
out:
	return res;
}

#define ATA_IDENTIFY_DEV         0xEC
#define ATA_IDENTIFY_PACKET_DEV  0xA1
#define ATA_SET_FEATURES         0xEF
#define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07

/**
 * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
 * @dev: STP/SATA device of interest (ATA/ATAPI)
 *
 * The LLDD has already been notified of this device, so that we can
 * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
 * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
 * performance for this device.
 */
static int sas_discover_sata_dev(struct domain_device *dev)
{
	int     res;
	__le16  *identify_x;
	u8      command;

	identify_x = kzalloc(512, GFP_KERNEL);
	if (!identify_x)
		return -ENOMEM;

	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
		dev->sata_dev.identify_device = identify_x;
		command = ATA_IDENTIFY_DEV;
	} else {
		dev->sata_dev.identify_packet_device = identify_x;
		command = ATA_IDENTIFY_PACKET_DEV;
	}

	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
				DMA_FROM_DEVICE);
	if (res)
		goto out_err;

	/* lives on the media? */
	if (le16_to_cpu(identify_x[0]) & 4) {
		/* incomplete response */
		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
		if (!(identify_x[83] & cpu_to_le16(1<<6)))
			goto cont1;
		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
					ATA_FEATURE_PUP_STBY_SPIN_UP,
					NULL, 0, DMA_NONE);
		if (res)
			goto cont1;

		schedule_timeout_interruptible(5*HZ); /* More time? */
		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
					DMA_FROM_DEVICE);
		if (res)
			goto out_err;
	}
cont1:
	/* XXX Hint: register this SATA device with SATL.
	   When this returns, dev->sata_dev->lu is alive and
	   present.
	sas_satl_register_dev(dev);
	*/

	sas_fill_in_rphy(dev, dev->rphy);

	return 0;
out_err:
	dev->sata_dev.identify_packet_device = NULL;
	dev->sata_dev.identify_device = NULL;
	kfree(identify_x);
	return res;
}

static int sas_discover_sata_pm(struct domain_device *dev)
{
	return -ENODEV;
}

/**
 * sas_discover_sata -- discover an STP/SATA domain device
 * @dev: pointer to struct domain_device of interest
 *
 * First we notify the LLDD of this device, so we can send frames to
 * it.  Then depending on the type of device we call the appropriate
 * discover functions.  Once device discover is done, we notify the
 * LLDD so that it can fine-tune its parameters for the device, by
 * removing it and then adding it.  That is, the second time around,
 * the driver would have certain fields, that it is looking at, set.
 * Finally we initialize the kobj so that the device can be added to
 * the system at registration time.  Devices directly attached to a HA
 * port, have no parents.  All other devices do, and should have their
 * "parent" pointer set appropriately before calling this function.
 */
int sas_discover_sata(struct domain_device *dev)
{
	int res;

	sas_get_ata_command_set(dev);

	res = sas_notify_lldd_dev_found(dev);
	if (res)
		return res;

	switch (dev->dev_type) {
	case SATA_DEV:
		res = sas_discover_sata_dev(dev);
		break;
	case SATA_PM:
		res = sas_discover_sata_pm(dev);
		break;
	default:
		break;
	}
	sas_notify_lldd_dev_gone(dev);
	if (!res) {
		sas_notify_lldd_dev_found(dev);
		res = sas_rphy_add(dev->rphy);
	}

	return res;
}

void sas_ata_strategy_handler(struct Scsi_Host *shost)
{
	struct scsi_device *sdev;

	shost_for_each_device(sdev, shost) {
		struct domain_device *ddev = sdev_to_domain_dev(sdev);
		struct ata_port *ap = ddev->sata_dev.ap;

		if (!dev_is_sata(ddev))
			continue;

		ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
		ata_scsi_port_error_handler(shost, ap);
	}
}

int sas_ata_timed_out(struct scsi_cmnd *cmd, struct sas_task *task,
		      enum blk_eh_timer_return *rtn)
{
	struct domain_device *ddev = cmd_to_domain_dev(cmd);

	if (!dev_is_sata(ddev) || task)
		return 0;

	/* we're a sata device with no task, so this must be a libata
	 * eh timeout.  Ideally should hook into libata timeout
	 * handling, but there's no point, it just wants to activate
	 * the eh thread */
	*rtn = BLK_EH_NOT_HANDLED;
	return 1;
}

int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
	       struct list_head *done_q)
{
	int rtn = 0;
	struct scsi_cmnd *cmd, *n;
	struct ata_port *ap;

	do {
		LIST_HEAD(sata_q);

		ap = NULL;

		list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
			struct domain_device *ddev = cmd_to_domain_dev(cmd);

			if (!dev_is_sata(ddev) || TO_SAS_TASK(cmd))
				continue;
			if (ap && ap != ddev->sata_dev.ap)
				continue;
			ap = ddev->sata_dev.ap;
			rtn = 1;
			list_move(&cmd->eh_entry, &sata_q);
		}

		if (!list_empty(&sata_q)) {
			ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata cmd error handler\n");
			ata_scsi_cmd_error_handler(shost, ap, &sata_q);
			/*
			 * ata's error handler may leave the cmd on the list
			 * so make sure they don't remain on a stack list
			 * about to go out of scope.
			 *
			 * This looks strange, since the commands are
			 * now part of no list, but the next error
			 * action will be ata_port_error_handler()
			 * which takes no list and sweeps them up
			 * anyway from the ata tag array.
			 */
			while (!list_empty(&sata_q))
				list_del_init(sata_q.next);
		}
	} while (ap);

	return rtn;
}