1 /*
2  * Serial Attached SCSI (SAS) Discover process
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 
25 #include <linux/scatterlist.h>
26 #include <linux/slab.h>
27 #include <linux/async.h>
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_eh.h>
30 #include "sas_internal.h"
31 
32 #include <scsi/scsi_transport.h>
33 #include <scsi/scsi_transport_sas.h>
34 #include <scsi/sas_ata.h>
35 #include "../scsi_sas_internal.h"
36 
37 /* ---------- Basic task processing for discovery purposes ---------- */
38 
39 void sas_init_dev(struct domain_device *dev)
40 {
41 	switch (dev->dev_type) {
42 	case SAS_END_DEVICE:
43 		INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
44 		break;
45 	case SAS_EDGE_EXPANDER_DEVICE:
46 	case SAS_FANOUT_EXPANDER_DEVICE:
47 		INIT_LIST_HEAD(&dev->ex_dev.children);
48 		mutex_init(&dev->ex_dev.cmd_mutex);
49 		break;
50 	default:
51 		break;
52 	}
53 }
54 
55 /* ---------- Domain device discovery ---------- */
56 
57 /**
58  * sas_get_port_device - Discover devices which caused port creation
59  * @port: pointer to struct sas_port of interest
60  *
61  * Devices directly attached to a HA port, have no parent.  This is
62  * how we know they are (domain) "root" devices.  All other devices
63  * do, and should have their "parent" pointer set appropriately as
64  * soon as a child device is discovered.
65  */
66 static int sas_get_port_device(struct asd_sas_port *port)
67 {
68 	struct asd_sas_phy *phy;
69 	struct sas_rphy *rphy;
70 	struct domain_device *dev;
71 	int rc = -ENODEV;
72 
73 	dev = sas_alloc_device();
74 	if (!dev)
75 		return -ENOMEM;
76 
77 	spin_lock_irq(&port->phy_list_lock);
78 	if (list_empty(&port->phy_list)) {
79 		spin_unlock_irq(&port->phy_list_lock);
80 		sas_put_device(dev);
81 		return -ENODEV;
82 	}
83 	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
84 	spin_lock(&phy->frame_rcvd_lock);
85 	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
86 					     (size_t)phy->frame_rcvd_size));
87 	spin_unlock(&phy->frame_rcvd_lock);
88 	spin_unlock_irq(&port->phy_list_lock);
89 
90 	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
91 		struct dev_to_host_fis *fis =
92 			(struct dev_to_host_fis *) dev->frame_rcvd;
93 		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
94 		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
95 		    && (fis->device & ~0x10) == 0)
96 			dev->dev_type = SAS_SATA_PM;
97 		else
98 			dev->dev_type = SAS_SATA_DEV;
99 		dev->tproto = SAS_PROTOCOL_SATA;
100 	} else {
101 		struct sas_identify_frame *id =
102 			(struct sas_identify_frame *) dev->frame_rcvd;
103 		dev->dev_type = id->dev_type;
104 		dev->iproto = id->initiator_bits;
105 		dev->tproto = id->target_bits;
106 	}
107 
108 	sas_init_dev(dev);
109 
110 	dev->port = port;
111 	switch (dev->dev_type) {
112 	case SAS_SATA_DEV:
113 		rc = sas_ata_init(dev);
114 		if (rc) {
115 			rphy = NULL;
116 			break;
117 		}
118 		/* fall through */
119 	case SAS_END_DEVICE:
120 		rphy = sas_end_device_alloc(port->port);
121 		break;
122 	case SAS_EDGE_EXPANDER_DEVICE:
123 		rphy = sas_expander_alloc(port->port,
124 					  SAS_EDGE_EXPANDER_DEVICE);
125 		break;
126 	case SAS_FANOUT_EXPANDER_DEVICE:
127 		rphy = sas_expander_alloc(port->port,
128 					  SAS_FANOUT_EXPANDER_DEVICE);
129 		break;
130 	default:
131 		pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
132 		rphy = NULL;
133 		break;
134 	}
135 
136 	if (!rphy) {
137 		sas_put_device(dev);
138 		return rc;
139 	}
140 
141 	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
142 	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
143 	sas_fill_in_rphy(dev, rphy);
144 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
145 	port->port_dev = dev;
146 	dev->linkrate = port->linkrate;
147 	dev->min_linkrate = port->linkrate;
148 	dev->max_linkrate = port->linkrate;
149 	dev->pathways = port->num_phys;
150 	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
151 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
152 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
153 	port->disc.max_level = 0;
154 	sas_device_set_phy(dev, port->port);
155 
156 	dev->rphy = rphy;
157 	get_device(&dev->rphy->dev);
158 
159 	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
160 		list_add_tail(&dev->disco_list_node, &port->disco_list);
161 	else {
162 		spin_lock_irq(&port->dev_list_lock);
163 		list_add_tail(&dev->dev_list_node, &port->dev_list);
164 		spin_unlock_irq(&port->dev_list_lock);
165 	}
166 
167 	spin_lock_irq(&port->phy_list_lock);
168 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
169 		sas_phy_set_target(phy, dev);
170 	spin_unlock_irq(&port->phy_list_lock);
171 
172 	return 0;
173 }
174 
175 /* ---------- Discover and Revalidate ---------- */
176 
177 int sas_notify_lldd_dev_found(struct domain_device *dev)
178 {
179 	int res = 0;
180 	struct sas_ha_struct *sas_ha = dev->port->ha;
181 	struct Scsi_Host *shost = sas_ha->core.shost;
182 	struct sas_internal *i = to_sas_internal(shost->transportt);
183 
184 	if (!i->dft->lldd_dev_found)
185 		return 0;
186 
187 	res = i->dft->lldd_dev_found(dev);
188 	if (res) {
189 		pr_warn("driver on host %s cannot handle device %llx, error:%d\n",
190 			dev_name(sas_ha->dev),
191 			SAS_ADDR(dev->sas_addr), res);
192 	}
193 	set_bit(SAS_DEV_FOUND, &dev->state);
194 	kref_get(&dev->kref);
195 	return res;
196 }
197 
198 
199 void sas_notify_lldd_dev_gone(struct domain_device *dev)
200 {
201 	struct sas_ha_struct *sas_ha = dev->port->ha;
202 	struct Scsi_Host *shost = sas_ha->core.shost;
203 	struct sas_internal *i = to_sas_internal(shost->transportt);
204 
205 	if (!i->dft->lldd_dev_gone)
206 		return;
207 
208 	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
209 		i->dft->lldd_dev_gone(dev);
210 		sas_put_device(dev);
211 	}
212 }
213 
214 static void sas_probe_devices(struct asd_sas_port *port)
215 {
216 	struct domain_device *dev, *n;
217 
218 	/* devices must be domain members before link recovery and probe */
219 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
220 		spin_lock_irq(&port->dev_list_lock);
221 		list_add_tail(&dev->dev_list_node, &port->dev_list);
222 		spin_unlock_irq(&port->dev_list_lock);
223 	}
224 
225 	sas_probe_sata(port);
226 
227 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
228 		int err;
229 
230 		err = sas_rphy_add(dev->rphy);
231 		if (err)
232 			sas_fail_probe(dev, __func__, err);
233 		else
234 			list_del_init(&dev->disco_list_node);
235 	}
236 }
237 
238 static void sas_suspend_devices(struct work_struct *work)
239 {
240 	struct asd_sas_phy *phy;
241 	struct domain_device *dev;
242 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
243 	struct asd_sas_port *port = ev->port;
244 	struct Scsi_Host *shost = port->ha->core.shost;
245 	struct sas_internal *si = to_sas_internal(shost->transportt);
246 
247 	clear_bit(DISCE_SUSPEND, &port->disc.pending);
248 
249 	sas_suspend_sata(port);
250 
251 	/* lldd is free to forget the domain_device across the
252 	 * suspension, we force the issue here to keep the reference
253 	 * counts aligned
254 	 */
255 	list_for_each_entry(dev, &port->dev_list, dev_list_node)
256 		sas_notify_lldd_dev_gone(dev);
257 
258 	/* we are suspending, so we know events are disabled and
259 	 * phy_list is not being mutated
260 	 */
261 	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
262 		if (si->dft->lldd_port_deformed)
263 			si->dft->lldd_port_deformed(phy);
264 		phy->suspended = 1;
265 		port->suspended = 1;
266 	}
267 }
268 
269 static void sas_resume_devices(struct work_struct *work)
270 {
271 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
272 	struct asd_sas_port *port = ev->port;
273 
274 	clear_bit(DISCE_RESUME, &port->disc.pending);
275 
276 	sas_resume_sata(port);
277 }
278 
279 /**
280  * sas_discover_end_dev - discover an end device (SSP, etc)
281  * @dev: pointer to domain device of interest
282  *
283  * See comment in sas_discover_sata().
284  */
285 int sas_discover_end_dev(struct domain_device *dev)
286 {
287 	int res;
288 
289 	res = sas_notify_lldd_dev_found(dev);
290 	if (res)
291 		return res;
292 
293 	return 0;
294 }
295 
296 /* ---------- Device registration and unregistration ---------- */
297 
298 void sas_free_device(struct kref *kref)
299 {
300 	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
301 
302 	put_device(&dev->rphy->dev);
303 	dev->rphy = NULL;
304 
305 	if (dev->parent)
306 		sas_put_device(dev->parent);
307 
308 	sas_port_put_phy(dev->phy);
309 	dev->phy = NULL;
310 
311 	/* remove the phys and ports, everything else should be gone */
312 	if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
313 		kfree(dev->ex_dev.ex_phy);
314 
315 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
316 		ata_sas_tport_delete(dev->sata_dev.ap);
317 		ata_sas_port_destroy(dev->sata_dev.ap);
318 		ata_host_put(dev->sata_dev.ata_host);
319 		dev->sata_dev.ata_host = NULL;
320 		dev->sata_dev.ap = NULL;
321 	}
322 
323 	kfree(dev);
324 }
325 
326 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
327 {
328 	struct sas_ha_struct *ha = port->ha;
329 
330 	sas_notify_lldd_dev_gone(dev);
331 	if (!dev->parent)
332 		dev->port->port_dev = NULL;
333 	else
334 		list_del_init(&dev->siblings);
335 
336 	spin_lock_irq(&port->dev_list_lock);
337 	list_del_init(&dev->dev_list_node);
338 	if (dev_is_sata(dev))
339 		sas_ata_end_eh(dev->sata_dev.ap);
340 	spin_unlock_irq(&port->dev_list_lock);
341 
342 	spin_lock_irq(&ha->lock);
343 	if (dev->dev_type == SAS_END_DEVICE &&
344 	    !list_empty(&dev->ssp_dev.eh_list_node)) {
345 		list_del_init(&dev->ssp_dev.eh_list_node);
346 		ha->eh_active--;
347 	}
348 	spin_unlock_irq(&ha->lock);
349 
350 	sas_put_device(dev);
351 }
352 
353 void sas_destruct_devices(struct asd_sas_port *port)
354 {
355 	struct domain_device *dev, *n;
356 
357 	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
358 		list_del_init(&dev->disco_list_node);
359 
360 		sas_remove_children(&dev->rphy->dev);
361 		sas_rphy_delete(dev->rphy);
362 		sas_unregister_common_dev(port, dev);
363 	}
364 }
365 
366 static void sas_destruct_ports(struct asd_sas_port *port)
367 {
368 	struct sas_port *sas_port, *p;
369 
370 	list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
371 		list_del_init(&sas_port->del_list);
372 		sas_port_delete(sas_port);
373 	}
374 }
375 
376 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
377 {
378 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
379 	    !list_empty(&dev->disco_list_node)) {
380 		/* this rphy never saw sas_rphy_add */
381 		list_del_init(&dev->disco_list_node);
382 		sas_rphy_free(dev->rphy);
383 		sas_unregister_common_dev(port, dev);
384 		return;
385 	}
386 
387 	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
388 		sas_rphy_unlink(dev->rphy);
389 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
390 	}
391 }
392 
393 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
394 {
395 	struct domain_device *dev, *n;
396 
397 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
398 		if (gone)
399 			set_bit(SAS_DEV_GONE, &dev->state);
400 		sas_unregister_dev(port, dev);
401 	}
402 
403 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
404 		sas_unregister_dev(port, dev);
405 
406 	port->port->rphy = NULL;
407 
408 }
409 
410 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
411 {
412 	struct sas_ha_struct *ha;
413 	struct sas_phy *new_phy;
414 
415 	if (!dev)
416 		return;
417 
418 	ha = dev->port->ha;
419 	new_phy = sas_port_get_phy(port);
420 
421 	/* pin and record last seen phy */
422 	spin_lock_irq(&ha->phy_port_lock);
423 	if (new_phy) {
424 		sas_port_put_phy(dev->phy);
425 		dev->phy = new_phy;
426 	}
427 	spin_unlock_irq(&ha->phy_port_lock);
428 }
429 
430 /* ---------- Discovery and Revalidation ---------- */
431 
432 /**
433  * sas_discover_domain - discover the domain
434  * @work: work structure embedded in port domain device.
435  *
436  * NOTE: this process _must_ quit (return) as soon as any connection
437  * errors are encountered.  Connection recovery is done elsewhere.
438  * Discover process only interrogates devices in order to discover the
439  * domain.
440  */
441 static void sas_discover_domain(struct work_struct *work)
442 {
443 	struct domain_device *dev;
444 	int error = 0;
445 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
446 	struct asd_sas_port *port = ev->port;
447 
448 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
449 
450 	if (port->port_dev)
451 		return;
452 
453 	error = sas_get_port_device(port);
454 	if (error)
455 		return;
456 	dev = port->port_dev;
457 
458 	pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
459 		 task_pid_nr(current));
460 
461 	switch (dev->dev_type) {
462 	case SAS_END_DEVICE:
463 		error = sas_discover_end_dev(dev);
464 		break;
465 	case SAS_EDGE_EXPANDER_DEVICE:
466 	case SAS_FANOUT_EXPANDER_DEVICE:
467 		error = sas_discover_root_expander(dev);
468 		break;
469 	case SAS_SATA_DEV:
470 	case SAS_SATA_PM:
471 #ifdef CONFIG_SCSI_SAS_ATA
472 		error = sas_discover_sata(dev);
473 		break;
474 #else
475 		pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
476 		/* Fall through */
477 #endif
478 	default:
479 		error = -ENXIO;
480 		pr_err("unhandled device %d\n", dev->dev_type);
481 		break;
482 	}
483 
484 	if (error) {
485 		sas_rphy_free(dev->rphy);
486 		list_del_init(&dev->disco_list_node);
487 		spin_lock_irq(&port->dev_list_lock);
488 		list_del_init(&dev->dev_list_node);
489 		spin_unlock_irq(&port->dev_list_lock);
490 
491 		sas_put_device(dev);
492 		port->port_dev = NULL;
493 	}
494 
495 	sas_probe_devices(port);
496 
497 	pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
498 		 task_pid_nr(current), error);
499 }
500 
501 static void sas_revalidate_domain(struct work_struct *work)
502 {
503 	int res = 0;
504 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
505 	struct asd_sas_port *port = ev->port;
506 	struct sas_ha_struct *ha = port->ha;
507 	struct domain_device *ddev = port->port_dev;
508 
509 	/* prevent revalidation from finding sata links in recovery */
510 	mutex_lock(&ha->disco_mutex);
511 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
512 		pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
513 			 port->id, task_pid_nr(current));
514 		goto out;
515 	}
516 
517 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
518 
519 	pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
520 		 task_pid_nr(current));
521 
522 	if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
523 		     ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
524 		res = sas_ex_revalidate_domain(ddev);
525 
526 	pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
527 		 port->id, task_pid_nr(current), res);
528  out:
529 	mutex_unlock(&ha->disco_mutex);
530 
531 	sas_destruct_devices(port);
532 	sas_destruct_ports(port);
533 	sas_probe_devices(port);
534 }
535 
536 /* ---------- Events ---------- */
537 
538 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
539 {
540 	/* chained work is not subject to SA_HA_DRAINING or
541 	 * SAS_HA_REGISTERED, because it is either submitted in the
542 	 * workqueue, or known to be submitted from a context that is
543 	 * not racing against draining
544 	 */
545 	queue_work(ha->disco_q, &sw->work);
546 }
547 
548 static void sas_chain_event(int event, unsigned long *pending,
549 			    struct sas_work *sw,
550 			    struct sas_ha_struct *ha)
551 {
552 	if (!test_and_set_bit(event, pending)) {
553 		unsigned long flags;
554 
555 		spin_lock_irqsave(&ha->lock, flags);
556 		sas_chain_work(ha, sw);
557 		spin_unlock_irqrestore(&ha->lock, flags);
558 	}
559 }
560 
561 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
562 {
563 	struct sas_discovery *disc;
564 
565 	if (!port)
566 		return 0;
567 	disc = &port->disc;
568 
569 	BUG_ON(ev >= DISC_NUM_EVENTS);
570 
571 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
572 
573 	return 0;
574 }
575 
576 /**
577  * sas_init_disc - initialize the discovery struct in the port
578  * @disc: port discovery structure
579  * @port: pointer to struct port
580  *
581  * Called when the ports are being initialized.
582  */
583 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
584 {
585 	int i;
586 
587 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
588 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
589 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
590 		[DISCE_SUSPEND] = sas_suspend_devices,
591 		[DISCE_RESUME] = sas_resume_devices,
592 	};
593 
594 	disc->pending = 0;
595 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
596 		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
597 		disc->disc_work[i].port = port;
598 	}
599 }
600