1 /*
2  * Serial Attached SCSI (SAS) Discover process
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 
25 #include <linux/scatterlist.h>
26 #include <linux/slab.h>
27 #include <linux/async.h>
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_eh.h>
30 #include "sas_internal.h"
31 
32 #include <scsi/scsi_transport.h>
33 #include <scsi/scsi_transport_sas.h>
34 #include <scsi/sas_ata.h>
35 #include "../scsi_sas_internal.h"
36 
37 /* ---------- Basic task processing for discovery purposes ---------- */
38 
39 void sas_init_dev(struct domain_device *dev)
40 {
41 	switch (dev->dev_type) {
42 	case SAS_END_DEVICE:
43 		INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
44 		break;
45 	case SAS_EDGE_EXPANDER_DEVICE:
46 	case SAS_FANOUT_EXPANDER_DEVICE:
47 		INIT_LIST_HEAD(&dev->ex_dev.children);
48 		mutex_init(&dev->ex_dev.cmd_mutex);
49 		break;
50 	default:
51 		break;
52 	}
53 }
54 
55 /* ---------- Domain device discovery ---------- */
56 
57 /**
58  * sas_get_port_device -- Discover devices which caused port creation
59  * @port: pointer to struct sas_port of interest
60  *
61  * Devices directly attached to a HA port, have no parent.  This is
62  * how we know they are (domain) "root" devices.  All other devices
63  * do, and should have their "parent" pointer set appropriately as
64  * soon as a child device is discovered.
65  */
66 static int sas_get_port_device(struct asd_sas_port *port)
67 {
68 	struct asd_sas_phy *phy;
69 	struct sas_rphy *rphy;
70 	struct domain_device *dev;
71 	int rc = -ENODEV;
72 
73 	dev = sas_alloc_device();
74 	if (!dev)
75 		return -ENOMEM;
76 
77 	spin_lock_irq(&port->phy_list_lock);
78 	if (list_empty(&port->phy_list)) {
79 		spin_unlock_irq(&port->phy_list_lock);
80 		sas_put_device(dev);
81 		return -ENODEV;
82 	}
83 	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
84 	spin_lock(&phy->frame_rcvd_lock);
85 	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
86 					     (size_t)phy->frame_rcvd_size));
87 	spin_unlock(&phy->frame_rcvd_lock);
88 	spin_unlock_irq(&port->phy_list_lock);
89 
90 	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
91 		struct dev_to_host_fis *fis =
92 			(struct dev_to_host_fis *) dev->frame_rcvd;
93 		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
94 		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
95 		    && (fis->device & ~0x10) == 0)
96 			dev->dev_type = SAS_SATA_PM;
97 		else
98 			dev->dev_type = SAS_SATA_DEV;
99 		dev->tproto = SAS_PROTOCOL_SATA;
100 	} else {
101 		struct sas_identify_frame *id =
102 			(struct sas_identify_frame *) dev->frame_rcvd;
103 		dev->dev_type = id->dev_type;
104 		dev->iproto = id->initiator_bits;
105 		dev->tproto = id->target_bits;
106 	}
107 
108 	sas_init_dev(dev);
109 
110 	dev->port = port;
111 	switch (dev->dev_type) {
112 	case SAS_SATA_DEV:
113 		rc = sas_ata_init(dev);
114 		if (rc) {
115 			rphy = NULL;
116 			break;
117 		}
118 		/* fall through */
119 	case SAS_END_DEVICE:
120 		rphy = sas_end_device_alloc(port->port);
121 		break;
122 	case SAS_EDGE_EXPANDER_DEVICE:
123 		rphy = sas_expander_alloc(port->port,
124 					  SAS_EDGE_EXPANDER_DEVICE);
125 		break;
126 	case SAS_FANOUT_EXPANDER_DEVICE:
127 		rphy = sas_expander_alloc(port->port,
128 					  SAS_FANOUT_EXPANDER_DEVICE);
129 		break;
130 	default:
131 		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
132 		rphy = NULL;
133 		break;
134 	}
135 
136 	if (!rphy) {
137 		sas_put_device(dev);
138 		return rc;
139 	}
140 
141 	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
142 	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
143 	sas_fill_in_rphy(dev, rphy);
144 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
145 	port->port_dev = dev;
146 	dev->linkrate = port->linkrate;
147 	dev->min_linkrate = port->linkrate;
148 	dev->max_linkrate = port->linkrate;
149 	dev->pathways = port->num_phys;
150 	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
151 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
152 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
153 	port->disc.max_level = 0;
154 	sas_device_set_phy(dev, port->port);
155 
156 	dev->rphy = rphy;
157 	get_device(&dev->rphy->dev);
158 
159 	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
160 		list_add_tail(&dev->disco_list_node, &port->disco_list);
161 	else {
162 		spin_lock_irq(&port->dev_list_lock);
163 		list_add_tail(&dev->dev_list_node, &port->dev_list);
164 		spin_unlock_irq(&port->dev_list_lock);
165 	}
166 
167 	spin_lock_irq(&port->phy_list_lock);
168 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
169 		sas_phy_set_target(phy, dev);
170 	spin_unlock_irq(&port->phy_list_lock);
171 
172 	return 0;
173 }
174 
175 /* ---------- Discover and Revalidate ---------- */
176 
177 int sas_notify_lldd_dev_found(struct domain_device *dev)
178 {
179 	int res = 0;
180 	struct sas_ha_struct *sas_ha = dev->port->ha;
181 	struct Scsi_Host *shost = sas_ha->core.shost;
182 	struct sas_internal *i = to_sas_internal(shost->transportt);
183 
184 	if (!i->dft->lldd_dev_found)
185 		return 0;
186 
187 	res = i->dft->lldd_dev_found(dev);
188 	if (res) {
189 		printk("sas: driver on pcidev %s cannot handle "
190 		       "device %llx, error:%d\n",
191 		       dev_name(sas_ha->dev),
192 		       SAS_ADDR(dev->sas_addr), res);
193 	}
194 	set_bit(SAS_DEV_FOUND, &dev->state);
195 	kref_get(&dev->kref);
196 	return res;
197 }
198 
199 
200 void sas_notify_lldd_dev_gone(struct domain_device *dev)
201 {
202 	struct sas_ha_struct *sas_ha = dev->port->ha;
203 	struct Scsi_Host *shost = sas_ha->core.shost;
204 	struct sas_internal *i = to_sas_internal(shost->transportt);
205 
206 	if (!i->dft->lldd_dev_gone)
207 		return;
208 
209 	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
210 		i->dft->lldd_dev_gone(dev);
211 		sas_put_device(dev);
212 	}
213 }
214 
215 static void sas_probe_devices(struct work_struct *work)
216 {
217 	struct domain_device *dev, *n;
218 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
219 	struct asd_sas_port *port = ev->port;
220 
221 	clear_bit(DISCE_PROBE, &port->disc.pending);
222 
223 	/* devices must be domain members before link recovery and probe */
224 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
225 		spin_lock_irq(&port->dev_list_lock);
226 		list_add_tail(&dev->dev_list_node, &port->dev_list);
227 		spin_unlock_irq(&port->dev_list_lock);
228 	}
229 
230 	sas_probe_sata(port);
231 
232 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
233 		int err;
234 
235 		err = sas_rphy_add(dev->rphy);
236 		if (err)
237 			sas_fail_probe(dev, __func__, err);
238 		else
239 			list_del_init(&dev->disco_list_node);
240 	}
241 }
242 
243 static void sas_suspend_devices(struct work_struct *work)
244 {
245 	struct asd_sas_phy *phy;
246 	struct domain_device *dev;
247 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
248 	struct asd_sas_port *port = ev->port;
249 	struct Scsi_Host *shost = port->ha->core.shost;
250 	struct sas_internal *si = to_sas_internal(shost->transportt);
251 
252 	clear_bit(DISCE_SUSPEND, &port->disc.pending);
253 
254 	sas_suspend_sata(port);
255 
256 	/* lldd is free to forget the domain_device across the
257 	 * suspension, we force the issue here to keep the reference
258 	 * counts aligned
259 	 */
260 	list_for_each_entry(dev, &port->dev_list, dev_list_node)
261 		sas_notify_lldd_dev_gone(dev);
262 
263 	/* we are suspending, so we know events are disabled and
264 	 * phy_list is not being mutated
265 	 */
266 	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
267 		if (si->dft->lldd_port_formed)
268 			si->dft->lldd_port_deformed(phy);
269 		phy->suspended = 1;
270 		port->suspended = 1;
271 	}
272 }
273 
274 static void sas_resume_devices(struct work_struct *work)
275 {
276 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
277 	struct asd_sas_port *port = ev->port;
278 
279 	clear_bit(DISCE_RESUME, &port->disc.pending);
280 
281 	sas_resume_sata(port);
282 }
283 
284 /**
285  * sas_discover_end_dev -- discover an end device (SSP, etc)
286  * @end: pointer to domain device of interest
287  *
288  * See comment in sas_discover_sata().
289  */
290 int sas_discover_end_dev(struct domain_device *dev)
291 {
292 	int res;
293 
294 	res = sas_notify_lldd_dev_found(dev);
295 	if (res)
296 		return res;
297 	sas_discover_event(dev->port, DISCE_PROBE);
298 
299 	return 0;
300 }
301 
302 /* ---------- Device registration and unregistration ---------- */
303 
304 void sas_free_device(struct kref *kref)
305 {
306 	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
307 
308 	put_device(&dev->rphy->dev);
309 	dev->rphy = NULL;
310 
311 	if (dev->parent)
312 		sas_put_device(dev->parent);
313 
314 	sas_port_put_phy(dev->phy);
315 	dev->phy = NULL;
316 
317 	/* remove the phys and ports, everything else should be gone */
318 	if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
319 		kfree(dev->ex_dev.ex_phy);
320 
321 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
322 		ata_sas_port_destroy(dev->sata_dev.ap);
323 		dev->sata_dev.ap = NULL;
324 	}
325 
326 	kfree(dev);
327 }
328 
329 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
330 {
331 	struct sas_ha_struct *ha = port->ha;
332 
333 	sas_notify_lldd_dev_gone(dev);
334 	if (!dev->parent)
335 		dev->port->port_dev = NULL;
336 	else
337 		list_del_init(&dev->siblings);
338 
339 	spin_lock_irq(&port->dev_list_lock);
340 	list_del_init(&dev->dev_list_node);
341 	if (dev_is_sata(dev))
342 		sas_ata_end_eh(dev->sata_dev.ap);
343 	spin_unlock_irq(&port->dev_list_lock);
344 
345 	spin_lock_irq(&ha->lock);
346 	if (dev->dev_type == SAS_END_DEVICE &&
347 	    !list_empty(&dev->ssp_dev.eh_list_node)) {
348 		list_del_init(&dev->ssp_dev.eh_list_node);
349 		ha->eh_active--;
350 	}
351 	spin_unlock_irq(&ha->lock);
352 
353 	sas_put_device(dev);
354 }
355 
356 static void sas_destruct_devices(struct work_struct *work)
357 {
358 	struct domain_device *dev, *n;
359 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
360 	struct asd_sas_port *port = ev->port;
361 
362 	clear_bit(DISCE_DESTRUCT, &port->disc.pending);
363 
364 	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
365 		list_del_init(&dev->disco_list_node);
366 
367 		sas_remove_children(&dev->rphy->dev);
368 		sas_rphy_delete(dev->rphy);
369 		sas_unregister_common_dev(port, dev);
370 	}
371 }
372 
373 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
374 {
375 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
376 	    !list_empty(&dev->disco_list_node)) {
377 		/* this rphy never saw sas_rphy_add */
378 		list_del_init(&dev->disco_list_node);
379 		sas_rphy_free(dev->rphy);
380 		sas_unregister_common_dev(port, dev);
381 		return;
382 	}
383 
384 	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
385 		sas_rphy_unlink(dev->rphy);
386 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
387 		sas_discover_event(dev->port, DISCE_DESTRUCT);
388 	}
389 }
390 
391 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
392 {
393 	struct domain_device *dev, *n;
394 
395 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
396 		if (gone)
397 			set_bit(SAS_DEV_GONE, &dev->state);
398 		sas_unregister_dev(port, dev);
399 	}
400 
401 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
402 		sas_unregister_dev(port, dev);
403 
404 	port->port->rphy = NULL;
405 
406 }
407 
408 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
409 {
410 	struct sas_ha_struct *ha;
411 	struct sas_phy *new_phy;
412 
413 	if (!dev)
414 		return;
415 
416 	ha = dev->port->ha;
417 	new_phy = sas_port_get_phy(port);
418 
419 	/* pin and record last seen phy */
420 	spin_lock_irq(&ha->phy_port_lock);
421 	if (new_phy) {
422 		sas_port_put_phy(dev->phy);
423 		dev->phy = new_phy;
424 	}
425 	spin_unlock_irq(&ha->phy_port_lock);
426 }
427 
428 /* ---------- Discovery and Revalidation ---------- */
429 
430 /**
431  * sas_discover_domain -- discover the domain
432  * @port: port to the domain of interest
433  *
434  * NOTE: this process _must_ quit (return) as soon as any connection
435  * errors are encountered.  Connection recovery is done elsewhere.
436  * Discover process only interrogates devices in order to discover the
437  * domain.
438  */
439 static void sas_discover_domain(struct work_struct *work)
440 {
441 	struct domain_device *dev;
442 	int error = 0;
443 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
444 	struct asd_sas_port *port = ev->port;
445 
446 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
447 
448 	if (port->port_dev)
449 		return;
450 
451 	error = sas_get_port_device(port);
452 	if (error)
453 		return;
454 	dev = port->port_dev;
455 
456 	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
457 		    task_pid_nr(current));
458 
459 	switch (dev->dev_type) {
460 	case SAS_END_DEVICE:
461 		error = sas_discover_end_dev(dev);
462 		break;
463 	case SAS_EDGE_EXPANDER_DEVICE:
464 	case SAS_FANOUT_EXPANDER_DEVICE:
465 		error = sas_discover_root_expander(dev);
466 		break;
467 	case SAS_SATA_DEV:
468 	case SAS_SATA_PM:
469 #ifdef CONFIG_SCSI_SAS_ATA
470 		error = sas_discover_sata(dev);
471 		break;
472 #else
473 		SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
474 		/* Fall through */
475 #endif
476 	default:
477 		error = -ENXIO;
478 		SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
479 		break;
480 	}
481 
482 	if (error) {
483 		sas_rphy_free(dev->rphy);
484 		list_del_init(&dev->disco_list_node);
485 		spin_lock_irq(&port->dev_list_lock);
486 		list_del_init(&dev->dev_list_node);
487 		spin_unlock_irq(&port->dev_list_lock);
488 
489 		sas_put_device(dev);
490 		port->port_dev = NULL;
491 	}
492 
493 	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
494 		    task_pid_nr(current), error);
495 }
496 
497 static void sas_revalidate_domain(struct work_struct *work)
498 {
499 	int res = 0;
500 	struct sas_discovery_event *ev = to_sas_discovery_event(work);
501 	struct asd_sas_port *port = ev->port;
502 	struct sas_ha_struct *ha = port->ha;
503 	struct domain_device *ddev = port->port_dev;
504 
505 	/* prevent revalidation from finding sata links in recovery */
506 	mutex_lock(&ha->disco_mutex);
507 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
508 		SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
509 			    port->id, task_pid_nr(current));
510 		goto out;
511 	}
512 
513 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
514 
515 	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
516 		    task_pid_nr(current));
517 
518 	if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
519 		     ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
520 		res = sas_ex_revalidate_domain(ddev);
521 
522 	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
523 		    port->id, task_pid_nr(current), res);
524  out:
525 	mutex_unlock(&ha->disco_mutex);
526 }
527 
528 /* ---------- Events ---------- */
529 
530 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
531 {
532 	/* chained work is not subject to SA_HA_DRAINING or
533 	 * SAS_HA_REGISTERED, because it is either submitted in the
534 	 * workqueue, or known to be submitted from a context that is
535 	 * not racing against draining
536 	 */
537 	scsi_queue_work(ha->core.shost, &sw->work);
538 }
539 
540 static void sas_chain_event(int event, unsigned long *pending,
541 			    struct sas_work *sw,
542 			    struct sas_ha_struct *ha)
543 {
544 	if (!test_and_set_bit(event, pending)) {
545 		unsigned long flags;
546 
547 		spin_lock_irqsave(&ha->lock, flags);
548 		sas_chain_work(ha, sw);
549 		spin_unlock_irqrestore(&ha->lock, flags);
550 	}
551 }
552 
553 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
554 {
555 	struct sas_discovery *disc;
556 
557 	if (!port)
558 		return 0;
559 	disc = &port->disc;
560 
561 	BUG_ON(ev >= DISC_NUM_EVENTS);
562 
563 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
564 
565 	return 0;
566 }
567 
568 /**
569  * sas_init_disc -- initialize the discovery struct in the port
570  * @port: pointer to struct port
571  *
572  * Called when the ports are being initialized.
573  */
574 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
575 {
576 	int i;
577 
578 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
579 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
580 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
581 		[DISCE_PROBE] = sas_probe_devices,
582 		[DISCE_SUSPEND] = sas_suspend_devices,
583 		[DISCE_RESUME] = sas_resume_devices,
584 		[DISCE_DESTRUCT] = sas_destruct_devices,
585 	};
586 
587 	disc->pending = 0;
588 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
589 		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
590 		disc->disc_work[i].port = port;
591 	}
592 }
593