xref: /linux/drivers/scsi/libsas/sas_discover.c (revision 2dbf708448c836754d25fe6108c5bfe1f5697c95)
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 		break;
43 	case EDGE_DEV:
44 	case FANOUT_DEV:
45 		INIT_LIST_HEAD(&dev->ex_dev.children);
46 		mutex_init(&dev->ex_dev.cmd_mutex);
47 		break;
48 	case SATA_DEV:
49 	case SATA_PM:
50 	case SATA_PM_PORT:
51 	case SATA_PENDING:
52 		INIT_LIST_HEAD(&dev->sata_dev.children);
53 		break;
54 	default:
55 		break;
56 	}
57 }
58 
59 /* ---------- Domain device discovery ---------- */
60 
61 /**
62  * sas_get_port_device -- Discover devices which caused port creation
63  * @port: pointer to struct sas_port of interest
64  *
65  * Devices directly attached to a HA port, have no parent.  This is
66  * how we know they are (domain) "root" devices.  All other devices
67  * do, and should have their "parent" pointer set appropriately as
68  * soon as a child device is discovered.
69  */
70 static int sas_get_port_device(struct asd_sas_port *port)
71 {
72 	struct asd_sas_phy *phy;
73 	struct sas_rphy *rphy;
74 	struct domain_device *dev;
75 
76 	dev = sas_alloc_device();
77 	if (!dev)
78 		return -ENOMEM;
79 
80 	spin_lock_irq(&port->phy_list_lock);
81 	if (list_empty(&port->phy_list)) {
82 		spin_unlock_irq(&port->phy_list_lock);
83 		sas_put_device(dev);
84 		return -ENODEV;
85 	}
86 	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
87 	spin_lock(&phy->frame_rcvd_lock);
88 	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
89 					     (size_t)phy->frame_rcvd_size));
90 	spin_unlock(&phy->frame_rcvd_lock);
91 	spin_unlock_irq(&port->phy_list_lock);
92 
93 	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
94 		struct dev_to_host_fis *fis =
95 			(struct dev_to_host_fis *) dev->frame_rcvd;
96 		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
97 		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
98 		    && (fis->device & ~0x10) == 0)
99 			dev->dev_type = SATA_PM;
100 		else
101 			dev->dev_type = SATA_DEV;
102 		dev->tproto = SAS_PROTOCOL_SATA;
103 	} else {
104 		struct sas_identify_frame *id =
105 			(struct sas_identify_frame *) dev->frame_rcvd;
106 		dev->dev_type = id->dev_type;
107 		dev->iproto = id->initiator_bits;
108 		dev->tproto = id->target_bits;
109 	}
110 
111 	sas_init_dev(dev);
112 
113 	switch (dev->dev_type) {
114 	case SAS_END_DEV:
115 	case SATA_DEV:
116 		rphy = sas_end_device_alloc(port->port);
117 		break;
118 	case EDGE_DEV:
119 		rphy = sas_expander_alloc(port->port,
120 					  SAS_EDGE_EXPANDER_DEVICE);
121 		break;
122 	case FANOUT_DEV:
123 		rphy = sas_expander_alloc(port->port,
124 					  SAS_FANOUT_EXPANDER_DEVICE);
125 		break;
126 	default:
127 		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
128 		rphy = NULL;
129 		break;
130 	}
131 
132 	if (!rphy) {
133 		sas_put_device(dev);
134 		return -ENODEV;
135 	}
136 
137 	spin_lock_irq(&port->phy_list_lock);
138 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
139 		sas_phy_set_target(phy, dev);
140 	spin_unlock_irq(&port->phy_list_lock);
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->port = port;
147 	dev->linkrate = port->linkrate;
148 	dev->min_linkrate = port->linkrate;
149 	dev->max_linkrate = port->linkrate;
150 	dev->pathways = port->num_phys;
151 	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
152 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
153 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
154 	port->disc.max_level = 0;
155 	sas_device_set_phy(dev, port->port);
156 
157 	dev->rphy = rphy;
158 
159 	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEV)
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 	return 0;
168 }
169 
170 /* ---------- Discover and Revalidate ---------- */
171 
172 int sas_notify_lldd_dev_found(struct domain_device *dev)
173 {
174 	int res = 0;
175 	struct sas_ha_struct *sas_ha = dev->port->ha;
176 	struct Scsi_Host *shost = sas_ha->core.shost;
177 	struct sas_internal *i = to_sas_internal(shost->transportt);
178 
179 	if (i->dft->lldd_dev_found) {
180 		res = i->dft->lldd_dev_found(dev);
181 		if (res) {
182 			printk("sas: driver on pcidev %s cannot handle "
183 			       "device %llx, error:%d\n",
184 			       dev_name(sas_ha->dev),
185 			       SAS_ADDR(dev->sas_addr), res);
186 		}
187 		kref_get(&dev->kref);
188 	}
189 	return res;
190 }
191 
192 
193 void sas_notify_lldd_dev_gone(struct domain_device *dev)
194 {
195 	struct sas_ha_struct *sas_ha = dev->port->ha;
196 	struct Scsi_Host *shost = sas_ha->core.shost;
197 	struct sas_internal *i = to_sas_internal(shost->transportt);
198 
199 	if (i->dft->lldd_dev_gone) {
200 		i->dft->lldd_dev_gone(dev);
201 		sas_put_device(dev);
202 	}
203 }
204 
205 static void sas_probe_devices(struct work_struct *work)
206 {
207 	struct domain_device *dev, *n;
208 	struct sas_discovery_event *ev =
209 		container_of(work, struct sas_discovery_event, work);
210 	struct asd_sas_port *port = ev->port;
211 
212 	clear_bit(DISCE_PROBE, &port->disc.pending);
213 
214 	/* devices must be domain members before link recovery and probe */
215 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
216 		spin_lock_irq(&port->dev_list_lock);
217 		list_add_tail(&dev->dev_list_node, &port->dev_list);
218 		spin_unlock_irq(&port->dev_list_lock);
219 	}
220 
221 	sas_probe_sata(port);
222 
223 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
224 		int err;
225 
226 		err = sas_rphy_add(dev->rphy);
227 		if (err)
228 			sas_fail_probe(dev, __func__, err);
229 		else
230 			list_del_init(&dev->disco_list_node);
231 	}
232 }
233 
234 /**
235  * sas_discover_end_dev -- discover an end device (SSP, etc)
236  * @end: pointer to domain device of interest
237  *
238  * See comment in sas_discover_sata().
239  */
240 int sas_discover_end_dev(struct domain_device *dev)
241 {
242 	int res;
243 
244 	res = sas_notify_lldd_dev_found(dev);
245 	if (res)
246 		return res;
247 	sas_discover_event(dev->port, DISCE_PROBE);
248 
249 	return 0;
250 }
251 
252 /* ---------- Device registration and unregistration ---------- */
253 
254 void sas_free_device(struct kref *kref)
255 {
256 	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
257 
258 	if (dev->parent)
259 		sas_put_device(dev->parent);
260 
261 	sas_port_put_phy(dev->phy);
262 	dev->phy = NULL;
263 
264 	/* remove the phys and ports, everything else should be gone */
265 	if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV)
266 		kfree(dev->ex_dev.ex_phy);
267 
268 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
269 		ata_sas_port_destroy(dev->sata_dev.ap);
270 		dev->sata_dev.ap = NULL;
271 	}
272 
273 	kfree(dev);
274 }
275 
276 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
277 {
278 	sas_notify_lldd_dev_gone(dev);
279 	if (!dev->parent)
280 		dev->port->port_dev = NULL;
281 	else
282 		list_del_init(&dev->siblings);
283 
284 	spin_lock_irq(&port->dev_list_lock);
285 	list_del_init(&dev->dev_list_node);
286 	spin_unlock_irq(&port->dev_list_lock);
287 
288 	sas_put_device(dev);
289 }
290 
291 static void sas_destruct_devices(struct work_struct *work)
292 {
293 	struct domain_device *dev, *n;
294 	struct sas_discovery_event *ev =
295 		container_of(work, struct sas_discovery_event, work);
296 	struct asd_sas_port *port = ev->port;
297 
298 	clear_bit(DISCE_DESTRUCT, &port->disc.pending);
299 
300 	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
301 		list_del_init(&dev->disco_list_node);
302 
303 		sas_remove_children(&dev->rphy->dev);
304 		sas_rphy_delete(dev->rphy);
305 		dev->rphy = NULL;
306 		sas_unregister_common_dev(port, dev);
307 	}
308 }
309 
310 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
311 {
312 	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
313 	    !list_empty(&dev->disco_list_node)) {
314 		/* this rphy never saw sas_rphy_add */
315 		list_del_init(&dev->disco_list_node);
316 		sas_rphy_free(dev->rphy);
317 		dev->rphy = NULL;
318 		sas_unregister_common_dev(port, dev);
319 	}
320 
321 	if (dev->rphy && !test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
322 		sas_rphy_unlink(dev->rphy);
323 		list_move_tail(&dev->disco_list_node, &port->destroy_list);
324 		sas_discover_event(dev->port, DISCE_DESTRUCT);
325 	}
326 }
327 
328 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
329 {
330 	struct domain_device *dev, *n;
331 
332 	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
333 		if (gone)
334 			set_bit(SAS_DEV_GONE, &dev->state);
335 		sas_unregister_dev(port, dev);
336 	}
337 
338 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
339 		sas_unregister_dev(port, dev);
340 
341 	port->port->rphy = NULL;
342 
343 }
344 
345 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
346 {
347 	struct sas_ha_struct *ha;
348 	struct sas_phy *new_phy;
349 
350 	if (!dev)
351 		return;
352 
353 	ha = dev->port->ha;
354 	new_phy = sas_port_get_phy(port);
355 
356 	/* pin and record last seen phy */
357 	spin_lock_irq(&ha->phy_port_lock);
358 	if (new_phy) {
359 		sas_port_put_phy(dev->phy);
360 		dev->phy = new_phy;
361 	}
362 	spin_unlock_irq(&ha->phy_port_lock);
363 }
364 
365 /* ---------- Discovery and Revalidation ---------- */
366 
367 /**
368  * sas_discover_domain -- discover the domain
369  * @port: port to the domain of interest
370  *
371  * NOTE: this process _must_ quit (return) as soon as any connection
372  * errors are encountered.  Connection recovery is done elsewhere.
373  * Discover process only interrogates devices in order to discover the
374  * domain.
375  */
376 static void sas_discover_domain(struct work_struct *work)
377 {
378 	struct domain_device *dev;
379 	int error = 0;
380 	struct sas_discovery_event *ev =
381 		container_of(work, struct sas_discovery_event, work);
382 	struct asd_sas_port *port = ev->port;
383 
384 	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
385 
386 	if (port->port_dev)
387 		return;
388 
389 	error = sas_get_port_device(port);
390 	if (error)
391 		return;
392 	dev = port->port_dev;
393 
394 	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
395 		    task_pid_nr(current));
396 
397 	switch (dev->dev_type) {
398 	case SAS_END_DEV:
399 		error = sas_discover_end_dev(dev);
400 		break;
401 	case EDGE_DEV:
402 	case FANOUT_DEV:
403 		error = sas_discover_root_expander(dev);
404 		break;
405 	case SATA_DEV:
406 	case SATA_PM:
407 #ifdef CONFIG_SCSI_SAS_ATA
408 		error = sas_discover_sata(dev);
409 		break;
410 #else
411 		SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
412 		/* Fall through */
413 #endif
414 	default:
415 		error = -ENXIO;
416 		SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
417 		break;
418 	}
419 
420 	if (error) {
421 		sas_rphy_free(dev->rphy);
422 		dev->rphy = NULL;
423 
424 		list_del_init(&dev->disco_list_node);
425 		spin_lock_irq(&port->dev_list_lock);
426 		list_del_init(&dev->dev_list_node);
427 		spin_unlock_irq(&port->dev_list_lock);
428 
429 		sas_put_device(dev);
430 		port->port_dev = NULL;
431 	}
432 
433 	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
434 		    task_pid_nr(current), error);
435 }
436 
437 static void sas_revalidate_domain(struct work_struct *work)
438 {
439 	int res = 0;
440 	struct sas_discovery_event *ev =
441 		container_of(work, struct sas_discovery_event, work);
442 	struct asd_sas_port *port = ev->port;
443 	struct sas_ha_struct *ha = port->ha;
444 
445 	/* prevent revalidation from finding sata links in recovery */
446 	mutex_lock(&ha->disco_mutex);
447 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
448 		SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
449 			    port->id, task_pid_nr(current));
450 		goto out;
451 	}
452 
453 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
454 
455 	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
456 		    task_pid_nr(current));
457 
458 	if (port->port_dev)
459 		res = sas_ex_revalidate_domain(port->port_dev);
460 
461 	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
462 		    port->id, task_pid_nr(current), res);
463  out:
464 	mutex_unlock(&ha->disco_mutex);
465 }
466 
467 /* ---------- Events ---------- */
468 
469 static void sas_chain_work(struct sas_ha_struct *ha, struct work_struct *work)
470 {
471 	/* chained work is not subject to SA_HA_DRAINING or SAS_HA_REGISTERED */
472 	scsi_queue_work(ha->core.shost, work);
473 }
474 
475 static void sas_chain_event(int event, unsigned long *pending,
476 			    struct work_struct *work,
477 			    struct sas_ha_struct *ha)
478 {
479 	if (!test_and_set_bit(event, pending)) {
480 		unsigned long flags;
481 
482 		spin_lock_irqsave(&ha->state_lock, flags);
483 		sas_chain_work(ha, work);
484 		spin_unlock_irqrestore(&ha->state_lock, flags);
485 	}
486 }
487 
488 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
489 {
490 	struct sas_discovery *disc;
491 
492 	if (!port)
493 		return 0;
494 	disc = &port->disc;
495 
496 	BUG_ON(ev >= DISC_NUM_EVENTS);
497 
498 	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
499 
500 	return 0;
501 }
502 
503 /**
504  * sas_init_disc -- initialize the discovery struct in the port
505  * @port: pointer to struct port
506  *
507  * Called when the ports are being initialized.
508  */
509 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
510 {
511 	int i;
512 
513 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
514 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
515 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
516 		[DISCE_PROBE] = sas_probe_devices,
517 		[DISCE_DESTRUCT] = sas_destruct_devices,
518 	};
519 
520 	disc->pending = 0;
521 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
522 		INIT_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
523 		disc->disc_work[i].port = port;
524 	}
525 }
526