1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Serial Attached SCSI (SAS) Discover process
4  *
5  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
6  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
7  */
8 
9 #include <linux/scatterlist.h>
10 #include <linux/slab.h>
11 #include <linux/async.h>
12 #include <scsi/scsi_host.h>
13 #include <scsi/scsi_eh.h>
14 #include "sas_internal.h"
15 
16 #include <scsi/scsi_transport.h>
17 #include <scsi/scsi_transport_sas.h>
18 #include <scsi/sas_ata.h>
19 #include "../scsi_sas_internal.h"
20 
21 /* ---------- Basic task processing for discovery purposes ---------- */
22 
23 void sas_init_dev(struct domain_device *dev)
24 {
25 	switch (dev->dev_type) {
26 	case SAS_END_DEVICE:
27 		INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
28 		break;
29 	case SAS_EDGE_EXPANDER_DEVICE:
30 	case SAS_FANOUT_EXPANDER_DEVICE:
31 		INIT_LIST_HEAD(&dev->ex_dev.children);
32 		mutex_init(&dev->ex_dev.cmd_mutex);
33 		break;
34 	default:
35 		break;
36 	}
37 }
38 
39 /* ---------- Domain device discovery ---------- */
40 
41 /**
42  * sas_get_port_device - Discover devices which caused port creation
43  * @port: pointer to struct sas_port of interest
44  *
45  * Devices directly attached to a HA port, have no parent.  This is
46  * how we know they are (domain) "root" devices.  All other devices
47  * do, and should have their "parent" pointer set appropriately as
48  * soon as a child device is discovered.
49  */
50 static int sas_get_port_device(struct asd_sas_port *port)
51 {
52 	struct asd_sas_phy *phy;
53 	struct sas_rphy *rphy;
54 	struct domain_device *dev;
55 	int rc = -ENODEV;
56 
57 	dev = sas_alloc_device();
58 	if (!dev)
59 		return -ENOMEM;
60 
61 	spin_lock_irq(&port->phy_list_lock);
62 	if (list_empty(&port->phy_list)) {
63 		spin_unlock_irq(&port->phy_list_lock);
64 		sas_put_device(dev);
65 		return -ENODEV;
66 	}
67 	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
68 	spin_lock(&phy->frame_rcvd_lock);
69 	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
70 					     (size_t)phy->frame_rcvd_size));
71 	spin_unlock(&phy->frame_rcvd_lock);
72 	spin_unlock_irq(&port->phy_list_lock);
73 
74 	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
75 		struct dev_to_host_fis *fis =
76 			(struct dev_to_host_fis *) dev->frame_rcvd;
77 		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
78 		    fis->byte_count_low == 0x69 && fis->byte_count_high == 0x96
79 		    && (fis->device & ~0x10) == 0)
80 			dev->dev_type = SAS_SATA_PM;
81 		else
82 			dev->dev_type = SAS_SATA_DEV;
83 		dev->tproto = SAS_PROTOCOL_SATA;
84 	} else if (port->oob_mode == SAS_OOB_MODE) {
85 		struct sas_identify_frame *id =
86 			(struct sas_identify_frame *) dev->frame_rcvd;
87 		dev->dev_type = id->dev_type;
88 		dev->iproto = id->initiator_bits;
89 		dev->tproto = id->target_bits;
90 	} else {
91 		/* If the oob mode is OOB_NOT_CONNECTED, the port is
92 		 * disconnected due to race with PHY down. We cannot
93 		 * continue to discover this port
94 		 */
95 		sas_put_device(dev);
96 		pr_warn("Port %016llx is disconnected when discovering\n",
97 			SAS_ADDR(port->attached_sas_addr));
98 		return -ENODEV;
99 	}
100 
101 	sas_init_dev(dev);
102 
103 	dev->port = port;
104 	switch (dev->dev_type) {
105 	case SAS_SATA_DEV:
106 		rc = sas_ata_init(dev);
107 		if (rc) {
108 			rphy = NULL;
109 			break;
110 		}
111 		fallthrough;
112 	case SAS_END_DEVICE:
113 		rphy = sas_end_device_alloc(port->port);
114 		break;
115 	case SAS_EDGE_EXPANDER_DEVICE:
116 		rphy = sas_expander_alloc(port->port,
117 					  SAS_EDGE_EXPANDER_DEVICE);
118 		break;
119 	case SAS_FANOUT_EXPANDER_DEVICE:
120 		rphy = sas_expander_alloc(port->port,
121 					  SAS_FANOUT_EXPANDER_DEVICE);
122 		break;
123 	default:
124 		pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
125 		rphy = NULL;
126 		break;
127 	}
128 
129 	if (!rphy) {
130 		sas_put_device(dev);
131 		return rc;
132 	}
133 
134 	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
135 	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
136 	sas_fill_in_rphy(dev, rphy);
137 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
138 	port->port_dev = dev;
139 	dev->linkrate = port->linkrate;
140 	dev->min_linkrate = port->linkrate;
141 	dev->max_linkrate = port->linkrate;
142 	dev->pathways = port->num_phys;
143 	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
144 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
145 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
146 	port->disc.max_level = 0;
147 	sas_device_set_phy(dev, port->port);
148 
149 	dev->rphy = rphy;
150 	get_device(&dev->rphy->dev);
151 
152 	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
153 		list_add_tail(&dev->disco_list_node, &port->disco_list);
154 	else {
155 		spin_lock_irq(&port->dev_list_lock);
156 		list_add_tail(&dev->dev_list_node, &port->dev_list);
157 		spin_unlock_irq(&port->dev_list_lock);
158 	}
159 
160 	spin_lock_irq(&port->phy_list_lock);
161 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
162 		sas_phy_set_target(phy, dev);
163 	spin_unlock_irq(&port->phy_list_lock);
164 
165 	return 0;
166 }
167 
168 /* ---------- Discover and Revalidate ---------- */
169 
170 int sas_notify_lldd_dev_found(struct domain_device *dev)
171 {
172 	int res = 0;
173 	struct sas_ha_struct *sas_ha = dev->port->ha;
174 	struct Scsi_Host *shost = sas_ha->core.shost;
175 	struct sas_internal *i = to_sas_internal(shost->transportt);
176 
177 	if (!i->dft->lldd_dev_found)
178 		return 0;
179 
180 	res = i->dft->lldd_dev_found(dev);
181 	if (res) {
182 		pr_warn("driver on host %s cannot handle device %016llx, error:%d\n",
183 			dev_name(sas_ha->dev),
184 			SAS_ADDR(dev->sas_addr), res);
185 		return res;
186 	}
187 	set_bit(SAS_DEV_FOUND, &dev->state);
188 	kref_get(&dev->kref);
189 	return 0;
190 }
191 
192 
193 void sas_notify_lldd_dev_gone(struct domain_device *dev)
194 {
195 	struct sas_ha_struct *sas_ha = dev->port->ha;
196 	struct Scsi_Host *shost = sas_ha->core.shost;
197 	struct sas_internal *i = to_sas_internal(shost->transportt);
198 
199 	if (!i->dft->lldd_dev_gone)
200 		return;
201 
202 	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
203 		i->dft->lldd_dev_gone(dev);
204 		sas_put_device(dev);
205 	}
206 }
207 
208 static void sas_probe_devices(struct asd_sas_port *port)
209 {
210 	struct domain_device *dev, *n;
211 
212 	/* devices must be domain members before link recovery and probe */
213 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
214 		spin_lock_irq(&port->dev_list_lock);
215 		list_add_tail(&dev->dev_list_node, &port->dev_list);
216 		spin_unlock_irq(&port->dev_list_lock);
217 	}
218 
219 	sas_probe_sata(port);
220 
221 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
222 		int err;
223 
224 		err = sas_rphy_add(dev->rphy);
225 		if (err)
226 			sas_fail_probe(dev, __func__, err);
227 		else
228 			list_del_init(&dev->disco_list_node);
229 	}
230 }
231 
232 static void sas_suspend_devices(struct work_struct *work)
233 {
234 	struct asd_sas_phy *phy;
235 	struct domain_device *dev;
236 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
237 	struct asd_sas_port *port = ev->port;
238 	struct Scsi_Host *shost = port->ha->core.shost;
239 	struct sas_internal *si = to_sas_internal(shost->transportt);
240 
241 	clear_bit(DISCE_SUSPEND, &port->disc.pending);
242 
243 	sas_suspend_sata(port);
244 
245 	/* lldd is free to forget the domain_device across the
246 	 * suspension, we force the issue here to keep the reference
247 	 * counts aligned
248 	 */
249 	list_for_each_entry(dev, &port->dev_list, dev_list_node)
250 		sas_notify_lldd_dev_gone(dev);
251 
252 	/* we are suspending, so we know events are disabled and
253 	 * phy_list is not being mutated
254 	 */
255 	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
256 		if (si->dft->lldd_port_deformed)
257 			si->dft->lldd_port_deformed(phy);
258 		phy->suspended = 1;
259 		port->suspended = 1;
260 	}
261 }
262 
263 static void sas_resume_devices(struct work_struct *work)
264 {
265 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
266 	struct asd_sas_port *port = ev->port;
267 
268 	clear_bit(DISCE_RESUME, &port->disc.pending);
269 
270 	sas_resume_sata(port);
271 }
272 
273 /**
274  * sas_discover_end_dev - discover an end device (SSP, etc)
275  * @dev: pointer to domain device of interest
276  *
277  * See comment in sas_discover_sata().
278  */
279 int sas_discover_end_dev(struct domain_device *dev)
280 {
281 	return sas_notify_lldd_dev_found(dev);
282 }
283 
284 /* ---------- Device registration and unregistration ---------- */
285 
286 void sas_free_device(struct kref *kref)
287 {
288 	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
289 
290 	put_device(&dev->rphy->dev);
291 	dev->rphy = NULL;
292 
293 	if (dev->parent)
294 		sas_put_device(dev->parent);
295 
296 	sas_port_put_phy(dev->phy);
297 	dev->phy = NULL;
298 
299 	/* remove the phys and ports, everything else should be gone */
300 	if (dev_is_expander(dev->dev_type))
301 		kfree(dev->ex_dev.ex_phy);
302 
303 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
304 		ata_sas_tport_delete(dev->sata_dev.ap);
305 		ata_sas_port_destroy(dev->sata_dev.ap);
306 		ata_host_put(dev->sata_dev.ata_host);
307 		dev->sata_dev.ata_host = NULL;
308 		dev->sata_dev.ap = NULL;
309 	}
310 
311 	kfree(dev);
312 }
313 
314 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
315 {
316 	struct sas_ha_struct *ha = port->ha;
317 
318 	sas_notify_lldd_dev_gone(dev);
319 	if (!dev->parent)
320 		dev->port->port_dev = NULL;
321 	else
322 		list_del_init(&dev->siblings);
323 
324 	spin_lock_irq(&port->dev_list_lock);
325 	list_del_init(&dev->dev_list_node);
326 	if (dev_is_sata(dev))
327 		sas_ata_end_eh(dev->sata_dev.ap);
328 	spin_unlock_irq(&port->dev_list_lock);
329 
330 	spin_lock_irq(&ha->lock);
331 	if (dev->dev_type == SAS_END_DEVICE &&
332 	    !list_empty(&dev->ssp_dev.eh_list_node)) {
333 		list_del_init(&dev->ssp_dev.eh_list_node);
334 		ha->eh_active--;
335 	}
336 	spin_unlock_irq(&ha->lock);
337 
338 	sas_put_device(dev);
339 }
340 
341 void sas_destruct_devices(struct asd_sas_port *port)
342 {
343 	struct domain_device *dev, *n;
344 
345 	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
346 		list_del_init(&dev->disco_list_node);
347 
348 		sas_remove_children(&dev->rphy->dev);
349 		sas_rphy_delete(dev->rphy);
350 		sas_unregister_common_dev(port, dev);
351 	}
352 }
353 
354 static void sas_destruct_ports(struct asd_sas_port *port)
355 {
356 	struct sas_port *sas_port, *p;
357 
358 	list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
359 		list_del_init(&sas_port->del_list);
360 		sas_port_delete(sas_port);
361 	}
362 }
363 
364 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
365 {
366 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
367 	    !list_empty(&dev->disco_list_node)) {
368 		/* this rphy never saw sas_rphy_add */
369 		list_del_init(&dev->disco_list_node);
370 		sas_rphy_free(dev->rphy);
371 		sas_unregister_common_dev(port, dev);
372 		return;
373 	}
374 
375 	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
376 		sas_rphy_unlink(dev->rphy);
377 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
378 	}
379 }
380 
381 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
382 {
383 	struct domain_device *dev, *n;
384 
385 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
386 		if (gone)
387 			set_bit(SAS_DEV_GONE, &dev->state);
388 		sas_unregister_dev(port, dev);
389 	}
390 
391 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
392 		sas_unregister_dev(port, dev);
393 
394 	port->port->rphy = NULL;
395 
396 }
397 
398 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
399 {
400 	struct sas_ha_struct *ha;
401 	struct sas_phy *new_phy;
402 
403 	if (!dev)
404 		return;
405 
406 	ha = dev->port->ha;
407 	new_phy = sas_port_get_phy(port);
408 
409 	/* pin and record last seen phy */
410 	spin_lock_irq(&ha->phy_port_lock);
411 	if (new_phy) {
412 		sas_port_put_phy(dev->phy);
413 		dev->phy = new_phy;
414 	}
415 	spin_unlock_irq(&ha->phy_port_lock);
416 }
417 
418 /* ---------- Discovery and Revalidation ---------- */
419 
420 /**
421  * sas_discover_domain - discover the domain
422  * @work: work structure embedded in port domain device.
423  *
424  * NOTE: this process _must_ quit (return) as soon as any connection
425  * errors are encountered.  Connection recovery is done elsewhere.
426  * Discover process only interrogates devices in order to discover the
427  * domain.
428  */
429 static void sas_discover_domain(struct work_struct *work)
430 {
431 	struct domain_device *dev;
432 	int error = 0;
433 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
434 	struct asd_sas_port *port = ev->port;
435 
436 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
437 
438 	if (port->port_dev)
439 		return;
440 
441 	error = sas_get_port_device(port);
442 	if (error)
443 		return;
444 	dev = port->port_dev;
445 
446 	pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
447 		 task_pid_nr(current));
448 
449 	switch (dev->dev_type) {
450 	case SAS_END_DEVICE:
451 		error = sas_discover_end_dev(dev);
452 		break;
453 	case SAS_EDGE_EXPANDER_DEVICE:
454 	case SAS_FANOUT_EXPANDER_DEVICE:
455 		error = sas_discover_root_expander(dev);
456 		break;
457 	case SAS_SATA_DEV:
458 	case SAS_SATA_PM:
459 #ifdef CONFIG_SCSI_SAS_ATA
460 		error = sas_discover_sata(dev);
461 		break;
462 #else
463 		pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
464 		/* Fall through */
465 #endif
466 		/* Fall through - only for the #else condition above. */
467 	default:
468 		error = -ENXIO;
469 		pr_err("unhandled device %d\n", dev->dev_type);
470 		break;
471 	}
472 
473 	if (error) {
474 		sas_rphy_free(dev->rphy);
475 		list_del_init(&dev->disco_list_node);
476 		spin_lock_irq(&port->dev_list_lock);
477 		list_del_init(&dev->dev_list_node);
478 		spin_unlock_irq(&port->dev_list_lock);
479 
480 		sas_put_device(dev);
481 		port->port_dev = NULL;
482 	}
483 
484 	sas_probe_devices(port);
485 
486 	pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
487 		 task_pid_nr(current), error);
488 }
489 
490 static void sas_revalidate_domain(struct work_struct *work)
491 {
492 	int res = 0;
493 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
494 	struct asd_sas_port *port = ev->port;
495 	struct sas_ha_struct *ha = port->ha;
496 	struct domain_device *ddev = port->port_dev;
497 
498 	/* prevent revalidation from finding sata links in recovery */
499 	mutex_lock(&ha->disco_mutex);
500 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
501 		pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
502 			 port->id, task_pid_nr(current));
503 		goto out;
504 	}
505 
506 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
507 
508 	pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
509 		 task_pid_nr(current));
510 
511 	if (ddev && dev_is_expander(ddev->dev_type))
512 		res = sas_ex_revalidate_domain(ddev);
513 
514 	pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
515 		 port->id, task_pid_nr(current), res);
516  out:
517 	mutex_unlock(&ha->disco_mutex);
518 
519 	sas_destruct_devices(port);
520 	sas_destruct_ports(port);
521 	sas_probe_devices(port);
522 }
523 
524 /* ---------- Events ---------- */
525 
526 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
527 {
528 	/* chained work is not subject to SA_HA_DRAINING or
529 	 * SAS_HA_REGISTERED, because it is either submitted in the
530 	 * workqueue, or known to be submitted from a context that is
531 	 * not racing against draining
532 	 */
533 	queue_work(ha->disco_q, &sw->work);
534 }
535 
536 static void sas_chain_event(int event, unsigned long *pending,
537 			    struct sas_work *sw,
538 			    struct sas_ha_struct *ha)
539 {
540 	if (!test_and_set_bit(event, pending)) {
541 		unsigned long flags;
542 
543 		spin_lock_irqsave(&ha->lock, flags);
544 		sas_chain_work(ha, sw);
545 		spin_unlock_irqrestore(&ha->lock, flags);
546 	}
547 }
548 
549 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
550 {
551 	struct sas_discovery *disc;
552 
553 	if (!port)
554 		return 0;
555 	disc = &port->disc;
556 
557 	BUG_ON(ev >= DISC_NUM_EVENTS);
558 
559 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
560 
561 	return 0;
562 }
563 
564 /**
565  * sas_init_disc - initialize the discovery struct in the port
566  * @disc: port discovery structure
567  * @port: pointer to struct port
568  *
569  * Called when the ports are being initialized.
570  */
571 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
572 {
573 	int i;
574 
575 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
576 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
577 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
578 		[DISCE_SUSPEND] = sas_suspend_devices,
579 		[DISCE_RESUME] = sas_resume_devices,
580 	};
581 
582 	disc->pending = 0;
583 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
584 		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
585 		disc->disc_work[i].port = port;
586 	}
587 }
588