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 
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  */
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 
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 
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 
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 
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 
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  */
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 
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 
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 
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 
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 
363 static bool sas_abort_cmd(struct request *req, void *data)
364 {
365 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
366 	struct domain_device *dev = data;
367 
368 	if (dev == cmd_to_domain_dev(cmd))
369 		blk_abort_request(req);
370 	return true;
371 }
372 
373 static void sas_abort_device_scsi_cmds(struct domain_device *dev)
374 {
375 	struct sas_ha_struct *sas_ha = dev->port->ha;
376 	struct Scsi_Host *shost = sas_ha->core.shost;
377 
378 	if (dev_is_expander(dev->dev_type))
379 		return;
380 
381 	/*
382 	 * For removed device with active IOs, the user space applications have
383 	 * to spend very long time waiting for the timeout. This is not
384 	 * necessary because a removed device will not return the IOs.
385 	 * Abort the inflight IOs here so that EH can be quickly kicked in.
386 	 */
387 	blk_mq_tagset_busy_iter(&shost->tag_set, sas_abort_cmd, dev);
388 }
389 
390 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
391 {
392 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
393 	    !list_empty(&dev->disco_list_node)) {
394 		/* this rphy never saw sas_rphy_add */
395 		list_del_init(&dev->disco_list_node);
396 		sas_rphy_free(dev->rphy);
397 		sas_unregister_common_dev(port, dev);
398 		return;
399 	}
400 
401 	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
402 		if (test_bit(SAS_DEV_GONE, &dev->state))
403 			sas_abort_device_scsi_cmds(dev);
404 		sas_rphy_unlink(dev->rphy);
405 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
406 	}
407 }
408 
409 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
410 {
411 	struct domain_device *dev, *n;
412 
413 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
414 		if (gone)
415 			set_bit(SAS_DEV_GONE, &dev->state);
416 		sas_unregister_dev(port, dev);
417 	}
418 
419 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
420 		sas_unregister_dev(port, dev);
421 
422 	port->port->rphy = NULL;
423 
424 }
425 
426 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
427 {
428 	struct sas_ha_struct *ha;
429 	struct sas_phy *new_phy;
430 
431 	if (!dev)
432 		return;
433 
434 	ha = dev->port->ha;
435 	new_phy = sas_port_get_phy(port);
436 
437 	/* pin and record last seen phy */
438 	spin_lock_irq(&ha->phy_port_lock);
439 	if (new_phy) {
440 		sas_port_put_phy(dev->phy);
441 		dev->phy = new_phy;
442 	}
443 	spin_unlock_irq(&ha->phy_port_lock);
444 }
445 
446 /* ---------- Discovery and Revalidation ---------- */
447 
448 /**
449  * sas_discover_domain - discover the domain
450  * @work: work structure embedded in port domain device.
451  *
452  * NOTE: this process _must_ quit (return) as soon as any connection
453  * errors are encountered.  Connection recovery is done elsewhere.
454  * Discover process only interrogates devices in order to discover the
455  * domain.
456  */
457 static void sas_discover_domain(struct work_struct *work)
458 {
459 	struct domain_device *dev;
460 	int error = 0;
461 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
462 	struct asd_sas_port *port = ev->port;
463 
464 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
465 
466 	if (port->port_dev)
467 		return;
468 
469 	error = sas_get_port_device(port);
470 	if (error)
471 		return;
472 	dev = port->port_dev;
473 
474 	pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
475 		 task_pid_nr(current));
476 
477 	switch (dev->dev_type) {
478 	case SAS_END_DEVICE:
479 		error = sas_discover_end_dev(dev);
480 		break;
481 	case SAS_EDGE_EXPANDER_DEVICE:
482 	case SAS_FANOUT_EXPANDER_DEVICE:
483 		error = sas_discover_root_expander(dev);
484 		break;
485 	case SAS_SATA_DEV:
486 	case SAS_SATA_PM:
487 		error = sas_discover_sata(dev);
488 		break;
489 	default:
490 		error = -ENXIO;
491 		pr_err("unhandled device %d\n", dev->dev_type);
492 		break;
493 	}
494 
495 	if (error) {
496 		sas_rphy_free(dev->rphy);
497 		list_del_init(&dev->disco_list_node);
498 		spin_lock_irq(&port->dev_list_lock);
499 		list_del_init(&dev->dev_list_node);
500 		spin_unlock_irq(&port->dev_list_lock);
501 
502 		sas_put_device(dev);
503 		port->port_dev = NULL;
504 	}
505 
506 	sas_probe_devices(port);
507 
508 	pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
509 		 task_pid_nr(current), error);
510 }
511 
512 static void sas_revalidate_domain(struct work_struct *work)
513 {
514 	int res = 0;
515 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
516 	struct asd_sas_port *port = ev->port;
517 	struct sas_ha_struct *ha = port->ha;
518 	struct domain_device *ddev = port->port_dev;
519 
520 	/* prevent revalidation from finding sata links in recovery */
521 	mutex_lock(&ha->disco_mutex);
522 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
523 		pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
524 			 port->id, task_pid_nr(current));
525 		goto out;
526 	}
527 
528 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
529 
530 	pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
531 		 task_pid_nr(current));
532 
533 	if (ddev && dev_is_expander(ddev->dev_type))
534 		res = sas_ex_revalidate_domain(ddev);
535 
536 	pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
537 		 port->id, task_pid_nr(current), res);
538  out:
539 	mutex_unlock(&ha->disco_mutex);
540 
541 	sas_destruct_devices(port);
542 	sas_destruct_ports(port);
543 	sas_probe_devices(port);
544 }
545 
546 /* ---------- Events ---------- */
547 
548 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
549 {
550 	/* chained work is not subject to SA_HA_DRAINING or
551 	 * SAS_HA_REGISTERED, because it is either submitted in the
552 	 * workqueue, or known to be submitted from a context that is
553 	 * not racing against draining
554 	 */
555 	queue_work(ha->disco_q, &sw->work);
556 }
557 
558 static void sas_chain_event(int event, unsigned long *pending,
559 			    struct sas_work *sw,
560 			    struct sas_ha_struct *ha)
561 {
562 	if (!test_and_set_bit(event, pending)) {
563 		unsigned long flags;
564 
565 		spin_lock_irqsave(&ha->lock, flags);
566 		sas_chain_work(ha, sw);
567 		spin_unlock_irqrestore(&ha->lock, flags);
568 	}
569 }
570 
571 void sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
572 {
573 	struct sas_discovery *disc;
574 
575 	if (!port)
576 		return;
577 	disc = &port->disc;
578 
579 	BUG_ON(ev >= DISC_NUM_EVENTS);
580 
581 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
582 }
583 
584 /**
585  * sas_init_disc - initialize the discovery struct in the port
586  * @disc: port discovery structure
587  * @port: pointer to struct port
588  *
589  * Called when the ports are being initialized.
590  */
591 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
592 {
593 	int i;
594 
595 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
596 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
597 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
598 		[DISCE_SUSPEND] = sas_suspend_devices,
599 		[DISCE_RESUME] = sas_resume_devices,
600 	};
601 
602 	disc->pending = 0;
603 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
604 		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
605 		disc->disc_work[i].port = port;
606 	}
607 }
608