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->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->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->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  static 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_tport_delete(dev->sata_dev.ap);
304  		ata_port_free(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_abort_cmd(struct request * req,void * data)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  
sas_abort_device_scsi_cmds(struct domain_device * dev)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->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  
sas_unregister_dev(struct asd_sas_port * port,struct domain_device * dev)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  
sas_unregister_domain_devices(struct asd_sas_port * port,int gone)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  
sas_device_set_phy(struct domain_device * dev,struct sas_port * port)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   */
sas_discover_domain(struct work_struct * work)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  
sas_revalidate_domain(struct work_struct * work)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  
sas_chain_work(struct sas_ha_struct * ha,struct sas_work * sw)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  
sas_chain_event(int event,unsigned long * pending,struct sas_work * sw,struct sas_ha_struct * ha)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  
sas_discover_event(struct asd_sas_port * port,enum discover_event ev)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   */
sas_init_disc(struct sas_discovery * disc,struct asd_sas_port * port)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