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
22void 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 */
49static 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
169int 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->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
192void 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->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
207static 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
231static 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->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
262static 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 */
278static 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
285void 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		kfree(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
313static 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
340void 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
353static 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
363static 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
373static 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->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
390void 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
409void 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
426void 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 */
457static 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
512static 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
548static 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
558static 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
571void 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 */
591void 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