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