summaryrefslogtreecommitdiff
path: root/drivers/scsi/libsas/sas_discover.c
blob: a0c3003e0c7d2f6b5e1a89147ab29d58b1609aaa (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
/*
 * Serial Attached SCSI (SAS) Discover process
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
 *
 * This file is licensed under GPLv2.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/async.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
#include "sas_internal.h"

#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include <scsi/sas_ata.h>
#include "../scsi_sas_internal.h"

/* ---------- Basic task processing for discovery purposes ---------- */

void sas_init_dev(struct domain_device *dev)
{
	switch (dev->dev_type) {
	case SAS_END_DEV:
		INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
		break;
	case EDGE_DEV:
	case FANOUT_DEV:
		INIT_LIST_HEAD(&dev->ex_dev.children);
		mutex_init(&dev->ex_dev.cmd_mutex);
		break;
	default:
		break;
	}
}

/* ---------- Domain device discovery ---------- */

/**
 * sas_get_port_device -- Discover devices which caused port creation
 * @port: pointer to struct sas_port of interest
 *
 * Devices directly attached to a HA port, have no parent.  This is
 * how we know they are (domain) "root" devices.  All other devices
 * do, and should have their "parent" pointer set appropriately as
 * soon as a child device is discovered.
 */
static int sas_get_port_device(struct asd_sas_port *port)
{
	struct asd_sas_phy *phy;
	struct sas_rphy *rphy;
	struct domain_device *dev;
	int rc = -ENODEV;

	dev = sas_alloc_device();
	if (!dev)
		return -ENOMEM;

	spin_lock_irq(&port->phy_list_lock);
	if (list_empty(&port->phy_list)) {
		spin_unlock_irq(&port->phy_list_lock);
		sas_put_device(dev);
		return -ENODEV;
	}
	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
	spin_lock(&phy->frame_rcvd_lock);
	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
					     (size_t)phy->frame_rcvd_size));
	spin_unlock(&phy->frame_rcvd_lock);
	spin_unlock_irq(&port->phy_list_lock);

	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
		struct dev_to_host_fis *fis =
			(struct dev_to_host_fis *) dev->frame_rcvd;
		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
		    && (fis->device & ~0x10) == 0)
			dev->dev_type = SATA_PM;
		else
			dev->dev_type = SATA_DEV;
		dev->tproto = SAS_PROTOCOL_SATA;
	} else {
		struct sas_identify_frame *id =
			(struct sas_identify_frame *) dev->frame_rcvd;
		dev->dev_type = id->dev_type;
		dev->iproto = id->initiator_bits;
		dev->tproto = id->target_bits;
	}

	sas_init_dev(dev);

	dev->port = port;
	switch (dev->dev_type) {
	case SATA_DEV:
		rc = sas_ata_init(dev);
		if (rc) {
			rphy = NULL;
			break;
		}
		/* fall through */
	case SAS_END_DEV:
		rphy = sas_end_device_alloc(port->port);
		break;
	case EDGE_DEV:
		rphy = sas_expander_alloc(port->port,
					  SAS_EDGE_EXPANDER_DEVICE);
		break;
	case FANOUT_DEV:
		rphy = sas_expander_alloc(port->port,
					  SAS_FANOUT_EXPANDER_DEVICE);
		break;
	default:
		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
		rphy = NULL;
		break;
	}

	if (!rphy) {
		sas_put_device(dev);
		return rc;
	}

	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
	sas_fill_in_rphy(dev, rphy);
	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
	port->port_dev = dev;
	dev->linkrate = port->linkrate;
	dev->min_linkrate = port->linkrate;
	dev->max_linkrate = port->linkrate;
	dev->pathways = port->num_phys;
	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
	port->disc.max_level = 0;
	sas_device_set_phy(dev, port->port);

	dev->rphy = rphy;
	get_device(&dev->rphy->dev);

	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEV)
		list_add_tail(&dev->disco_list_node, &port->disco_list);
	else {
		spin_lock_irq(&port->dev_list_lock);
		list_add_tail(&dev->dev_list_node, &port->dev_list);
		spin_unlock_irq(&port->dev_list_lock);
	}

	spin_lock_irq(&port->phy_list_lock);
	list_for_each_entry(phy, &port->phy_list, port_phy_el)
		sas_phy_set_target(phy, dev);
	spin_unlock_irq(&port->phy_list_lock);

	return 0;
}

/* ---------- Discover and Revalidate ---------- */

int sas_notify_lldd_dev_found(struct domain_device *dev)
{
	int res = 0;
	struct sas_ha_struct *sas_ha = dev->port->ha;
	struct Scsi_Host *shost = sas_ha->core.shost;
	struct sas_internal *i = to_sas_internal(shost->transportt);

	if (!i->dft->lldd_dev_found)
		return 0;

	res = i->dft->lldd_dev_found(dev);
	if (res) {
		printk("sas: driver on pcidev %s cannot handle "
		       "device %llx, error:%d\n",
		       dev_name(sas_ha->dev),
		       SAS_ADDR(dev->sas_addr), res);
	}
	set_bit(SAS_DEV_FOUND, &dev->state);
	kref_get(&dev->kref);
	return res;
}


void sas_notify_lldd_dev_gone(struct domain_device *dev)
{
	struct sas_ha_struct *sas_ha = dev->port->ha;
	struct Scsi_Host *shost = sas_ha->core.shost;
	struct sas_internal *i = to_sas_internal(shost->transportt);

	if (!i->dft->lldd_dev_gone)
		return;

	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
		i->dft->lldd_dev_gone(dev);
		sas_put_device(dev);
	}
}

static void sas_probe_devices(struct work_struct *work)
{
	struct domain_device *dev, *n;
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;

	clear_bit(DISCE_PROBE, &port->disc.pending);

	/* devices must be domain members before link recovery and probe */
	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
		spin_lock_irq(&port->dev_list_lock);
		list_add_tail(&dev->dev_list_node, &port->dev_list);
		spin_unlock_irq(&port->dev_list_lock);
	}

	sas_probe_sata(port);

	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
		int err;

		err = sas_rphy_add(dev->rphy);
		if (err)
			sas_fail_probe(dev, __func__, err);
		else
			list_del_init(&dev->disco_list_node);
	}
}

static void sas_suspend_devices(struct work_struct *work)
{
	struct asd_sas_phy *phy;
	struct domain_device *dev;
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;
	struct Scsi_Host *shost = port->ha->core.shost;
	struct sas_internal *si = to_sas_internal(shost->transportt);

	clear_bit(DISCE_SUSPEND, &port->disc.pending);

	sas_suspend_sata(port);

	/* lldd is free to forget the domain_device across the
	 * suspension, we force the issue here to keep the reference
	 * counts aligned
	 */
	list_for_each_entry(dev, &port->dev_list, dev_list_node)
		sas_notify_lldd_dev_gone(dev);

	/* we are suspending, so we know events are disabled and
	 * phy_list is not being mutated
	 */
	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
		if (si->dft->lldd_port_formed)
			si->dft->lldd_port_deformed(phy);
		phy->suspended = 1;
		port->suspended = 1;
	}
}

static void sas_resume_devices(struct work_struct *work)
{
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;

	clear_bit(DISCE_RESUME, &port->disc.pending);

	sas_resume_sata(port);
}

/**
 * sas_discover_end_dev -- discover an end device (SSP, etc)
 * @end: pointer to domain device of interest
 *
 * See comment in sas_discover_sata().
 */
int sas_discover_end_dev(struct domain_device *dev)
{
	int res;

	res = sas_notify_lldd_dev_found(dev);
	if (res)
		return res;
	sas_discover_event(dev->port, DISCE_PROBE);

	return 0;
}

/* ---------- Device registration and unregistration ---------- */

void sas_free_device(struct kref *kref)
{
	struct domain_device *dev = container_of(kref, typeof(*dev), kref);

	put_device(&dev->rphy->dev);
	dev->rphy = NULL;

	if (dev->parent)
		sas_put_device(dev->parent);

	sas_port_put_phy(dev->phy);
	dev->phy = NULL;

	/* remove the phys and ports, everything else should be gone */
	if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV)
		kfree(dev->ex_dev.ex_phy);

	if (dev_is_sata(dev) && dev->sata_dev.ap) {
		ata_sas_port_destroy(dev->sata_dev.ap);
		dev->sata_dev.ap = NULL;
	}

	kfree(dev);
}

static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
{
	struct sas_ha_struct *ha = port->ha;

	sas_notify_lldd_dev_gone(dev);
	if (!dev->parent)
		dev->port->port_dev = NULL;
	else
		list_del_init(&dev->siblings);

	spin_lock_irq(&port->dev_list_lock);
	list_del_init(&dev->dev_list_node);
	if (dev_is_sata(dev))
		sas_ata_end_eh(dev->sata_dev.ap);
	spin_unlock_irq(&port->dev_list_lock);

	spin_lock_irq(&ha->lock);
	if (dev->dev_type == SAS_END_DEV &&
	    !list_empty(&dev->ssp_dev.eh_list_node)) {
		list_del_init(&dev->ssp_dev.eh_list_node);
		ha->eh_active--;
	}
	spin_unlock_irq(&ha->lock);

	sas_put_device(dev);
}

static void sas_destruct_devices(struct work_struct *work)
{
	struct domain_device *dev, *n;
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;

	clear_bit(DISCE_DESTRUCT, &port->disc.pending);

	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
		list_del_init(&dev->disco_list_node);

		sas_remove_children(&dev->rphy->dev);
		sas_rphy_delete(dev->rphy);
		sas_unregister_common_dev(port, dev);
	}
}

void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
{
	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
	    !list_empty(&dev->disco_list_node)) {
		/* this rphy never saw sas_rphy_add */
		list_del_init(&dev->disco_list_node);
		sas_rphy_free(dev->rphy);
		sas_unregister_common_dev(port, dev);
		return;
	}

	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
		sas_rphy_unlink(dev->rphy);
		list_move_tail(&dev->disco_list_node, &port->destroy_list);
		sas_discover_event(dev->port, DISCE_DESTRUCT);
	}
}

void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
{
	struct domain_device *dev, *n;

	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
		if (gone)
			set_bit(SAS_DEV_GONE, &dev->state);
		sas_unregister_dev(port, dev);
	}

	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
		sas_unregister_dev(port, dev);

	port->port->rphy = NULL;

}

void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
{
	struct sas_ha_struct *ha;
	struct sas_phy *new_phy;

	if (!dev)
		return;

	ha = dev->port->ha;
	new_phy = sas_port_get_phy(port);

	/* pin and record last seen phy */
	spin_lock_irq(&ha->phy_port_lock);
	if (new_phy) {
		sas_port_put_phy(dev->phy);
		dev->phy = new_phy;
	}
	spin_unlock_irq(&ha->phy_port_lock);
}

/* ---------- Discovery and Revalidation ---------- */

/**
 * sas_discover_domain -- discover the domain
 * @port: port to the domain of interest
 *
 * NOTE: this process _must_ quit (return) as soon as any connection
 * errors are encountered.  Connection recovery is done elsewhere.
 * Discover process only interrogates devices in order to discover the
 * domain.
 */
static void sas_discover_domain(struct work_struct *work)
{
	struct domain_device *dev;
	int error = 0;
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;

	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);

	if (port->port_dev)
		return;

	error = sas_get_port_device(port);
	if (error)
		return;
	dev = port->port_dev;

	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
		    task_pid_nr(current));

	switch (dev->dev_type) {
	case SAS_END_DEV:
		error = sas_discover_end_dev(dev);
		break;
	case EDGE_DEV:
	case FANOUT_DEV:
		error = sas_discover_root_expander(dev);
		break;
	case SATA_DEV:
	case SATA_PM:
#ifdef CONFIG_SCSI_SAS_ATA
		error = sas_discover_sata(dev);
		break;
#else
		SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
		/* Fall through */
#endif
	default:
		error = -ENXIO;
		SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
		break;
	}

	if (error) {
		sas_rphy_free(dev->rphy);
		list_del_init(&dev->disco_list_node);
		spin_lock_irq(&port->dev_list_lock);
		list_del_init(&dev->dev_list_node);
		spin_unlock_irq(&port->dev_list_lock);

		sas_put_device(dev);
		port->port_dev = NULL;
	}

	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
		    task_pid_nr(current), error);
}

static void sas_revalidate_domain(struct work_struct *work)
{
	int res = 0;
	struct sas_discovery_event *ev = to_sas_discovery_event(work);
	struct asd_sas_port *port = ev->port;
	struct sas_ha_struct *ha = port->ha;

	/* prevent revalidation from finding sata links in recovery */
	mutex_lock(&ha->disco_mutex);
	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
		SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
			    port->id, task_pid_nr(current));
		goto out;
	}

	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);

	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
		    task_pid_nr(current));

	if (port->port_dev)
		res = sas_ex_revalidate_domain(port->port_dev);

	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
		    port->id, task_pid_nr(current), res);
 out:
	mutex_unlock(&ha->disco_mutex);
}

/* ---------- Events ---------- */

static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
{
	/* chained work is not subject to SA_HA_DRAINING or
	 * SAS_HA_REGISTERED, because it is either submitted in the
	 * workqueue, or known to be submitted from a context that is
	 * not racing against draining
	 */
	scsi_queue_work(ha->core.shost, &sw->work);
}

static void sas_chain_event(int event, unsigned long *pending,
			    struct sas_work *sw,
			    struct sas_ha_struct *ha)
{
	if (!test_and_set_bit(event, pending)) {
		unsigned long flags;

		spin_lock_irqsave(&ha->lock, flags);
		sas_chain_work(ha, sw);
		spin_unlock_irqrestore(&ha->lock, flags);
	}
}

int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
{
	struct sas_discovery *disc;

	if (!port)
		return 0;
	disc = &port->disc;

	BUG_ON(ev >= DISC_NUM_EVENTS);

	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);

	return 0;
}

/**
 * sas_init_disc -- initialize the discovery struct in the port
 * @port: pointer to struct port
 *
 * Called when the ports are being initialized.
 */
void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
{
	int i;

	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
		[DISCE_PROBE] = sas_probe_devices,
		[DISCE_SUSPEND] = sas_suspend_devices,
		[DISCE_RESUME] = sas_resume_devices,
		[DISCE_DESTRUCT] = sas_destruct_devices,
	};

	disc->pending = 0;
	for (i = 0; i < DISC_NUM_EVENTS; i++) {
		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
		disc->disc_work[i].port = port;
	}
}