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