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