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 		printk("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 		printk("sas: driver on pcidev %s cannot handle "
190 		       "device %llx, error:%d\n",
191 		       dev_name(sas_ha->dev),
192 		       SAS_ADDR(dev->sas_addr), res);
193 	}
194 	set_bit(SAS_DEV_FOUND, &dev->state);
195 	kref_get(&dev->kref);
196 	return res;
197 }
198 
199 
200 void sas_notify_lldd_dev_gone(struct domain_device *dev)
201 {
202 	struct sas_ha_struct *sas_ha = dev->port->ha;
203 	struct Scsi_Host *shost = sas_ha->core.shost;
204 	struct sas_internal *i = to_sas_internal(shost->transportt);
205 
206 	if (!i->dft->lldd_dev_gone)
207 		return;
208 
209 	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
210 		i->dft->lldd_dev_gone(dev);
211 		sas_put_device(dev);
212 	}
213 }
214 
215 static void sas_probe_devices(struct asd_sas_port *port)
216 {
217 	struct domain_device *dev, *n;
218 
219 	/* devices must be domain members before link recovery and probe */
220 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
221 		spin_lock_irq(&port->dev_list_lock);
222 		list_add_tail(&dev->dev_list_node, &port->dev_list);
223 		spin_unlock_irq(&port->dev_list_lock);
224 	}
225 
226 	sas_probe_sata(port);
227 
228 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
229 		int err;
230 
231 		err = sas_rphy_add(dev->rphy);
232 		if (err)
233 			sas_fail_probe(dev, __func__, err);
234 		else
235 			list_del_init(&dev->disco_list_node);
236 	}
237 }
238 
239 static void sas_suspend_devices(struct work_struct *work)
240 {
241 	struct asd_sas_phy *phy;
242 	struct domain_device *dev;
243 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
244 	struct asd_sas_port *port = ev->port;
245 	struct Scsi_Host *shost = port->ha->core.shost;
246 	struct sas_internal *si = to_sas_internal(shost->transportt);
247 
248 	clear_bit(DISCE_SUSPEND, &port->disc.pending);
249 
250 	sas_suspend_sata(port);
251 
252 	/* lldd is free to forget the domain_device across the
253 	 * suspension, we force the issue here to keep the reference
254 	 * counts aligned
255 	 */
256 	list_for_each_entry(dev, &port->dev_list, dev_list_node)
257 		sas_notify_lldd_dev_gone(dev);
258 
259 	/* we are suspending, so we know events are disabled and
260 	 * phy_list is not being mutated
261 	 */
262 	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
263 		if (si->dft->lldd_port_formed)
264 			si->dft->lldd_port_deformed(phy);
265 		phy->suspended = 1;
266 		port->suspended = 1;
267 	}
268 }
269 
270 static void sas_resume_devices(struct work_struct *work)
271 {
272 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
273 	struct asd_sas_port *port = ev->port;
274 
275 	clear_bit(DISCE_RESUME, &port->disc.pending);
276 
277 	sas_resume_sata(port);
278 }
279 
280 /**
281  * sas_discover_end_dev - discover an end device (SSP, etc)
282  * @dev: pointer to domain device of interest
283  *
284  * See comment in sas_discover_sata().
285  */
286 int sas_discover_end_dev(struct domain_device *dev)
287 {
288 	int res;
289 
290 	res = sas_notify_lldd_dev_found(dev);
291 	if (res)
292 		return res;
293 
294 	return 0;
295 }
296 
297 /* ---------- Device registration and unregistration ---------- */
298 
299 void sas_free_device(struct kref *kref)
300 {
301 	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
302 
303 	put_device(&dev->rphy->dev);
304 	dev->rphy = NULL;
305 
306 	if (dev->parent)
307 		sas_put_device(dev->parent);
308 
309 	sas_port_put_phy(dev->phy);
310 	dev->phy = NULL;
311 
312 	/* remove the phys and ports, everything else should be gone */
313 	if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
314 		kfree(dev->ex_dev.ex_phy);
315 
316 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
317 		ata_sas_tport_delete(dev->sata_dev.ap);
318 		ata_sas_port_destroy(dev->sata_dev.ap);
319 		ata_host_put(dev->sata_dev.ata_host);
320 		dev->sata_dev.ata_host = NULL;
321 		dev->sata_dev.ap = NULL;
322 	}
323 
324 	kfree(dev);
325 }
326 
327 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
328 {
329 	struct sas_ha_struct *ha = port->ha;
330 
331 	sas_notify_lldd_dev_gone(dev);
332 	if (!dev->parent)
333 		dev->port->port_dev = NULL;
334 	else
335 		list_del_init(&dev->siblings);
336 
337 	spin_lock_irq(&port->dev_list_lock);
338 	list_del_init(&dev->dev_list_node);
339 	if (dev_is_sata(dev))
340 		sas_ata_end_eh(dev->sata_dev.ap);
341 	spin_unlock_irq(&port->dev_list_lock);
342 
343 	spin_lock_irq(&ha->lock);
344 	if (dev->dev_type == SAS_END_DEVICE &&
345 	    !list_empty(&dev->ssp_dev.eh_list_node)) {
346 		list_del_init(&dev->ssp_dev.eh_list_node);
347 		ha->eh_active--;
348 	}
349 	spin_unlock_irq(&ha->lock);
350 
351 	sas_put_device(dev);
352 }
353 
354 void sas_destruct_devices(struct asd_sas_port *port)
355 {
356 	struct domain_device *dev, *n;
357 
358 	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
359 		list_del_init(&dev->disco_list_node);
360 
361 		sas_remove_children(&dev->rphy->dev);
362 		sas_rphy_delete(dev->rphy);
363 		sas_unregister_common_dev(port, dev);
364 	}
365 }
366 
367 static void sas_destruct_ports(struct asd_sas_port *port)
368 {
369 	struct sas_port *sas_port, *p;
370 
371 	list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
372 		list_del_init(&sas_port->del_list);
373 		sas_port_delete(sas_port);
374 	}
375 }
376 
377 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
378 {
379 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
380 	    !list_empty(&dev->disco_list_node)) {
381 		/* this rphy never saw sas_rphy_add */
382 		list_del_init(&dev->disco_list_node);
383 		sas_rphy_free(dev->rphy);
384 		sas_unregister_common_dev(port, dev);
385 		return;
386 	}
387 
388 	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
389 		sas_rphy_unlink(dev->rphy);
390 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
391 	}
392 }
393 
394 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
395 {
396 	struct domain_device *dev, *n;
397 
398 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
399 		if (gone)
400 			set_bit(SAS_DEV_GONE, &dev->state);
401 		sas_unregister_dev(port, dev);
402 	}
403 
404 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
405 		sas_unregister_dev(port, dev);
406 
407 	port->port->rphy = NULL;
408 
409 }
410 
411 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
412 {
413 	struct sas_ha_struct *ha;
414 	struct sas_phy *new_phy;
415 
416 	if (!dev)
417 		return;
418 
419 	ha = dev->port->ha;
420 	new_phy = sas_port_get_phy(port);
421 
422 	/* pin and record last seen phy */
423 	spin_lock_irq(&ha->phy_port_lock);
424 	if (new_phy) {
425 		sas_port_put_phy(dev->phy);
426 		dev->phy = new_phy;
427 	}
428 	spin_unlock_irq(&ha->phy_port_lock);
429 }
430 
431 /* ---------- Discovery and Revalidation ---------- */
432 
433 /**
434  * sas_discover_domain - discover the domain
435  * @work: work structure embedded in port domain device.
436  *
437  * NOTE: this process _must_ quit (return) as soon as any connection
438  * errors are encountered.  Connection recovery is done elsewhere.
439  * Discover process only interrogates devices in order to discover the
440  * domain.
441  */
442 static void sas_discover_domain(struct work_struct *work)
443 {
444 	struct domain_device *dev;
445 	int error = 0;
446 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
447 	struct asd_sas_port *port = ev->port;
448 
449 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
450 
451 	if (port->port_dev)
452 		return;
453 
454 	error = sas_get_port_device(port);
455 	if (error)
456 		return;
457 	dev = port->port_dev;
458 
459 	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
460 		    task_pid_nr(current));
461 
462 	switch (dev->dev_type) {
463 	case SAS_END_DEVICE:
464 		error = sas_discover_end_dev(dev);
465 		break;
466 	case SAS_EDGE_EXPANDER_DEVICE:
467 	case SAS_FANOUT_EXPANDER_DEVICE:
468 		error = sas_discover_root_expander(dev);
469 		break;
470 	case SAS_SATA_DEV:
471 	case SAS_SATA_PM:
472 #ifdef CONFIG_SCSI_SAS_ATA
473 		error = sas_discover_sata(dev);
474 		break;
475 #else
476 		SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
477 		/* Fall through */
478 #endif
479 	default:
480 		error = -ENXIO;
481 		SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
482 		break;
483 	}
484 
485 	if (error) {
486 		sas_rphy_free(dev->rphy);
487 		list_del_init(&dev->disco_list_node);
488 		spin_lock_irq(&port->dev_list_lock);
489 		list_del_init(&dev->dev_list_node);
490 		spin_unlock_irq(&port->dev_list_lock);
491 
492 		sas_put_device(dev);
493 		port->port_dev = NULL;
494 	}
495 
496 	sas_probe_devices(port);
497 
498 	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
499 		    task_pid_nr(current), error);
500 }
501 
502 static void sas_revalidate_domain(struct work_struct *work)
503 {
504 	int res = 0;
505 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
506 	struct asd_sas_port *port = ev->port;
507 	struct sas_ha_struct *ha = port->ha;
508 	struct domain_device *ddev = port->port_dev;
509 
510 	/* prevent revalidation from finding sata links in recovery */
511 	mutex_lock(&ha->disco_mutex);
512 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
513 		SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
514 			    port->id, task_pid_nr(current));
515 		goto out;
516 	}
517 
518 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
519 
520 	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
521 		    task_pid_nr(current));
522 
523 	if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
524 		     ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
525 		res = sas_ex_revalidate_domain(ddev);
526 
527 	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
528 		    port->id, task_pid_nr(current), res);
529  out:
530 	mutex_unlock(&ha->disco_mutex);
531 
532 	sas_destruct_devices(port);
533 	sas_destruct_ports(port);
534 	sas_probe_devices(port);
535 }
536 
537 /* ---------- Events ---------- */
538 
539 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
540 {
541 	/* chained work is not subject to SA_HA_DRAINING or
542 	 * SAS_HA_REGISTERED, because it is either submitted in the
543 	 * workqueue, or known to be submitted from a context that is
544 	 * not racing against draining
545 	 */
546 	queue_work(ha->disco_q, &sw->work);
547 }
548 
549 static void sas_chain_event(int event, unsigned long *pending,
550 			    struct sas_work *sw,
551 			    struct sas_ha_struct *ha)
552 {
553 	if (!test_and_set_bit(event, pending)) {
554 		unsigned long flags;
555 
556 		spin_lock_irqsave(&ha->lock, flags);
557 		sas_chain_work(ha, sw);
558 		spin_unlock_irqrestore(&ha->lock, flags);
559 	}
560 }
561 
562 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
563 {
564 	struct sas_discovery *disc;
565 
566 	if (!port)
567 		return 0;
568 	disc = &port->disc;
569 
570 	BUG_ON(ev >= DISC_NUM_EVENTS);
571 
572 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
573 
574 	return 0;
575 }
576 
577 /**
578  * sas_init_disc - initialize the discovery struct in the port
579  * @disc: port discovery structure
580  * @port: pointer to struct port
581  *
582  * Called when the ports are being initialized.
583  */
584 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
585 {
586 	int i;
587 
588 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
589 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
590 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
591 		[DISCE_SUSPEND] = sas_suspend_devices,
592 		[DISCE_RESUME] = sas_resume_devices,
593 	};
594 
595 	disc->pending = 0;
596 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
597 		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
598 		disc->disc_work[i].port = port;
599 	}
600 }
601