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/pci.h>
26 #include <linux/scatterlist.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_internal.h"
34 
35 /* ---------- Basic task processing for discovery purposes ---------- */
36 
37 void sas_init_dev(struct domain_device *dev)
38 {
39         INIT_LIST_HEAD(&dev->siblings);
40         INIT_LIST_HEAD(&dev->dev_list_node);
41         switch (dev->dev_type) {
42         case SAS_END_DEV:
43                 break;
44         case EDGE_DEV:
45         case FANOUT_DEV:
46                 INIT_LIST_HEAD(&dev->ex_dev.children);
47                 break;
48         case SATA_DEV:
49         case SATA_PM:
50         case SATA_PM_PORT:
51                 INIT_LIST_HEAD(&dev->sata_dev.children);
52                 break;
53         default:
54                 break;
55         }
56 }
57 
58 static void sas_task_timedout(unsigned long _task)
59 {
60 	struct sas_task *task = (void *) _task;
61 	unsigned long flags;
62 
63 	spin_lock_irqsave(&task->task_state_lock, flags);
64 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
65 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
66 	spin_unlock_irqrestore(&task->task_state_lock, flags);
67 
68 	complete(&task->completion);
69 }
70 
71 static void sas_disc_task_done(struct sas_task *task)
72 {
73 	if (!del_timer(&task->timer))
74 		return;
75 	complete(&task->completion);
76 }
77 
78 #define SAS_DEV_TIMEOUT 10
79 
80 /**
81  * sas_execute_task -- Basic task processing for discovery
82  * @task: the task to be executed
83  * @buffer: pointer to buffer to do I/O
84  * @size: size of @buffer
85  * @pci_dma_dir: PCI_DMA_...
86  */
87 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
88 			    int pci_dma_dir)
89 {
90 	int res = 0;
91 	struct scatterlist *scatter = NULL;
92 	struct task_status_struct *ts = &task->task_status;
93 	int num_scatter = 0;
94 	int retries = 0;
95 	struct sas_internal *i =
96 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
97 
98 	if (pci_dma_dir != PCI_DMA_NONE) {
99 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
100 		if (!scatter)
101 			goto out;
102 
103 		sg_init_one(scatter, buffer, size);
104 		num_scatter = 1;
105 	}
106 
107 	task->task_proto = task->dev->tproto;
108 	task->scatter = scatter;
109 	task->num_scatter = num_scatter;
110 	task->total_xfer_len = size;
111 	task->data_dir = pci_dma_dir;
112 	task->task_done = sas_disc_task_done;
113 
114 	for (retries = 0; retries < 5; retries++) {
115 		task->task_state_flags = SAS_TASK_STATE_PENDING;
116 		init_completion(&task->completion);
117 
118 		task->timer.data = (unsigned long) task;
119 		task->timer.function = sas_task_timedout;
120 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
121 		add_timer(&task->timer);
122 
123 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
124 		if (res) {
125 			del_timer(&task->timer);
126 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
127 				    res);
128 			goto ex_err;
129 		}
130 		wait_for_completion(&task->completion);
131 		res = -ETASK;
132 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
133 			int res2;
134 			SAS_DPRINTK("task aborted, flags:0x%x\n",
135 				    task->task_state_flags);
136 			res2 = i->dft->lldd_abort_task(task);
137 			SAS_DPRINTK("came back from abort task\n");
138 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
139 				if (res2 == TMF_RESP_FUNC_COMPLETE)
140 					continue; /* Retry the task */
141 				else
142 					goto ex_err;
143 			}
144 		}
145 		if (task->task_status.stat == SAM_BUSY ||
146 			   task->task_status.stat == SAM_TASK_SET_FULL ||
147 			   task->task_status.stat == SAS_QUEUE_FULL) {
148 			SAS_DPRINTK("task: q busy, sleeping...\n");
149 			schedule_timeout_interruptible(HZ);
150 		} else if (task->task_status.stat == SAM_CHECK_COND) {
151 			struct scsi_sense_hdr shdr;
152 
153 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
154 						  &shdr)) {
155 				SAS_DPRINTK("couldn't normalize sense\n");
156 				continue;
157 			}
158 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
159 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
160 			     shdr.ascq == 1)) {
161 				SAS_DPRINTK("device %016llx LUN: %016llx "
162 					    "powering up or not ready yet, "
163 					    "sleeping...\n",
164 					    SAS_ADDR(task->dev->sas_addr),
165 					    SAS_ADDR(task->ssp_task.LUN));
166 
167 				schedule_timeout_interruptible(5*HZ);
168 			} else if (shdr.sense_key == 1) {
169 				res = 0;
170 				break;
171 			} else if (shdr.sense_key == 5) {
172 				break;
173 			} else {
174 				SAS_DPRINTK("dev %016llx LUN: %016llx "
175 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
176 					    "\n",
177 					    SAS_ADDR(task->dev->sas_addr),
178 					    SAS_ADDR(task->ssp_task.LUN),
179 					    shdr.sense_key,
180 					    shdr.asc, shdr.ascq);
181 			}
182 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
183 			   task->task_status.stat != SAM_GOOD) {
184 			SAS_DPRINTK("task finished with resp:0x%x, "
185 				    "stat:0x%x\n",
186 				    task->task_status.resp,
187 				    task->task_status.stat);
188 			goto ex_err;
189 		} else {
190 			res = 0;
191 			break;
192 		}
193 	}
194 ex_err:
195 	if (pci_dma_dir != PCI_DMA_NONE)
196 		kfree(scatter);
197 out:
198 	return res;
199 }
200 
201 /* ---------- Domain device discovery ---------- */
202 
203 /**
204  * sas_get_port_device -- Discover devices which caused port creation
205  * @port: pointer to struct sas_port of interest
206  *
207  * Devices directly attached to a HA port, have no parent.  This is
208  * how we know they are (domain) "root" devices.  All other devices
209  * do, and should have their "parent" pointer set appropriately as
210  * soon as a child device is discovered.
211  */
212 static int sas_get_port_device(struct asd_sas_port *port)
213 {
214 	unsigned long flags;
215 	struct asd_sas_phy *phy;
216 	struct sas_rphy *rphy;
217 	struct domain_device *dev;
218 
219 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
220 	if (!dev)
221 		return -ENOMEM;
222 
223 	spin_lock_irqsave(&port->phy_list_lock, flags);
224 	if (list_empty(&port->phy_list)) {
225 		spin_unlock_irqrestore(&port->phy_list_lock, flags);
226 		kfree(dev);
227 		return -ENODEV;
228 	}
229 	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
230 	spin_lock(&phy->frame_rcvd_lock);
231 	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
232 					     (size_t)phy->frame_rcvd_size));
233 	spin_unlock(&phy->frame_rcvd_lock);
234 	spin_unlock_irqrestore(&port->phy_list_lock, flags);
235 
236 	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
237 		struct dev_to_host_fis *fis =
238 			(struct dev_to_host_fis *) dev->frame_rcvd;
239 		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
240 		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
241 		    && (fis->device & ~0x10) == 0)
242 			dev->dev_type = SATA_PM;
243 		else
244 			dev->dev_type = SATA_DEV;
245 		dev->tproto = SATA_PROTO;
246 	} else {
247 		struct sas_identify_frame *id =
248 			(struct sas_identify_frame *) dev->frame_rcvd;
249 		dev->dev_type = id->dev_type;
250 		dev->iproto = id->initiator_bits;
251 		dev->tproto = id->target_bits;
252 	}
253 
254 	sas_init_dev(dev);
255 
256 	switch (dev->dev_type) {
257 	case SAS_END_DEV:
258 		rphy = sas_end_device_alloc(port->port);
259 		break;
260 	case EDGE_DEV:
261 		rphy = sas_expander_alloc(port->port,
262 					  SAS_EDGE_EXPANDER_DEVICE);
263 		break;
264 	case FANOUT_DEV:
265 		rphy = sas_expander_alloc(port->port,
266 					  SAS_FANOUT_EXPANDER_DEVICE);
267 		break;
268 	case SATA_DEV:
269 	default:
270 		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
271 		rphy = NULL;
272 		break;
273 	}
274 
275 	if (!rphy) {
276 		kfree(dev);
277 		return -ENODEV;
278 	}
279 	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
280 	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
281 	sas_fill_in_rphy(dev, rphy);
282 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
283 	port->port_dev = dev;
284 	dev->port = port;
285 	dev->linkrate = port->linkrate;
286 	dev->min_linkrate = port->linkrate;
287 	dev->max_linkrate = port->linkrate;
288 	dev->pathways = port->num_phys;
289 	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
290 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
291 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
292 	port->disc.max_level = 0;
293 
294 	dev->rphy = rphy;
295 	spin_lock(&port->dev_list_lock);
296 	list_add_tail(&dev->dev_list_node, &port->dev_list);
297 	spin_unlock(&port->dev_list_lock);
298 
299 	return 0;
300 }
301 
302 /* ---------- Discover and Revalidate ---------- */
303 
304 /* ---------- SATA ---------- */
305 
306 static void sas_get_ata_command_set(struct domain_device *dev)
307 {
308 	struct dev_to_host_fis *fis =
309 		(struct dev_to_host_fis *) dev->frame_rcvd;
310 
311 	if ((fis->sector_count == 1 && /* ATA */
312 	     fis->lbal         == 1 &&
313 	     fis->lbam         == 0 &&
314 	     fis->lbah         == 0 &&
315 	     fis->device       == 0)
316 	    ||
317 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
318 	     fis->lbal         == 0 &&
319 	     fis->lbam         == 0xCE &&
320 	     fis->lbah         == 0xAA &&
321 	     (fis->device & ~0x10) == 0))
322 
323 		dev->sata_dev.command_set = ATA_COMMAND_SET;
324 
325 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
326 		  fis->lbal             == 1 &&
327 		  fis->byte_count_low   == 0x14 &&
328 		  fis->byte_count_high  == 0xEB &&
329 		  (fis->device & ~0x10) == 0))
330 
331 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
332 
333 	else if ((fis->sector_count == 1 && /* SEMB */
334 		  fis->lbal         == 1 &&
335 		  fis->lbam         == 0x3C &&
336 		  fis->lbah         == 0xC3 &&
337 		  fis->device       == 0)
338 		||
339 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
340 		  fis->lbal             == 1 &&
341 		  fis->byte_count_low   == 0x69 &&
342 		  fis->byte_count_high  == 0x96 &&
343 		  (fis->device & ~0x10) == 0))
344 
345 		/* Treat it as a superset? */
346 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
347 }
348 
349 /**
350  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
351  * @dev: the device to send the command to
352  * @command: the command register
353  * @features: the features register
354  * @buffer: pointer to buffer to do I/O
355  * @size: size of @buffer
356  * @pci_dma_dir: PCI_DMA_...
357  */
358 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
359 			     u8 features, void *buffer, int size,
360 			     int pci_dma_dir)
361 {
362 	int res = 0;
363 	struct sas_task *task;
364 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
365 		&dev->frame_rcvd[0];
366 
367 	res = -ENOMEM;
368 	task = sas_alloc_task(GFP_KERNEL);
369 	if (!task)
370 		goto out;
371 
372 	task->dev = dev;
373 
374 	task->ata_task.fis.command = command;
375 	task->ata_task.fis.features = features;
376 	task->ata_task.fis.device = d2h_fis->device;
377 	task->ata_task.retry_count = 1;
378 
379 	res = sas_execute_task(task, buffer, size, pci_dma_dir);
380 
381 	sas_free_task(task);
382 out:
383 	return res;
384 }
385 
386 static void sas_sata_propagate_sas_addr(struct domain_device *dev)
387 {
388 	unsigned long flags;
389 	struct asd_sas_port *port = dev->port;
390 	struct asd_sas_phy  *phy;
391 
392 	BUG_ON(dev->parent);
393 
394 	memcpy(port->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
395 	spin_lock_irqsave(&port->phy_list_lock, flags);
396 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
397 		memcpy(phy->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
398 	spin_unlock_irqrestore(&port->phy_list_lock, flags);
399 }
400 
401 #define ATA_IDENTIFY_DEV         0xEC
402 #define ATA_IDENTIFY_PACKET_DEV  0xA1
403 #define ATA_SET_FEATURES         0xEF
404 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
405 
406 /**
407  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
408  * @dev: STP/SATA device of interest (ATA/ATAPI)
409  *
410  * The LLDD has already been notified of this device, so that we can
411  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
412  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
413  * performance for this device.
414  */
415 static int sas_discover_sata_dev(struct domain_device *dev)
416 {
417 	int     res;
418 	__le16  *identify_x;
419 	u8      command;
420 
421 	identify_x = kzalloc(512, GFP_KERNEL);
422 	if (!identify_x)
423 		return -ENOMEM;
424 
425 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
426 		dev->sata_dev.identify_device = identify_x;
427 		command = ATA_IDENTIFY_DEV;
428 	} else {
429 		dev->sata_dev.identify_packet_device = identify_x;
430 		command = ATA_IDENTIFY_PACKET_DEV;
431 	}
432 
433 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
434 				PCI_DMA_FROMDEVICE);
435 	if (res)
436 		goto out_err;
437 
438 	/* lives on the media? */
439 	if (le16_to_cpu(identify_x[0]) & 4) {
440 		/* incomplete response */
441 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
442 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
443 		if (!le16_to_cpu(identify_x[83] & (1<<6)))
444 			goto cont1;
445 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
446 					ATA_FEATURE_PUP_STBY_SPIN_UP,
447 					NULL, 0, PCI_DMA_NONE);
448 		if (res)
449 			goto cont1;
450 
451 		schedule_timeout_interruptible(5*HZ); /* More time? */
452 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
453 					PCI_DMA_FROMDEVICE);
454 		if (res)
455 			goto out_err;
456 	}
457 cont1:
458 	/* Get WWN */
459 	if (dev->port->oob_mode != SATA_OOB_MODE) {
460 		memcpy(dev->sas_addr, dev->sata_dev.rps_resp.rps.stp_sas_addr,
461 		       SAS_ADDR_SIZE);
462 	} else if (dev->sata_dev.command_set == ATA_COMMAND_SET &&
463 		   (le16_to_cpu(dev->sata_dev.identify_device[108]) & 0xF000)
464 		   == 0x5000) {
465 		int i;
466 
467 		for (i = 0; i < 4; i++) {
468 			dev->sas_addr[2*i] =
469 	     (le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0xFF00) >> 8;
470 			dev->sas_addr[2*i+1] =
471 	      le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0x00FF;
472 		}
473 	}
474 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
475 	if (!dev->parent)
476 		sas_sata_propagate_sas_addr(dev);
477 
478 	/* XXX Hint: register this SATA device with SATL.
479 	   When this returns, dev->sata_dev->lu is alive and
480 	   present.
481 	sas_satl_register_dev(dev);
482 	*/
483 	return 0;
484 out_err:
485 	dev->sata_dev.identify_packet_device = NULL;
486 	dev->sata_dev.identify_device = NULL;
487 	kfree(identify_x);
488 	return res;
489 }
490 
491 static int sas_discover_sata_pm(struct domain_device *dev)
492 {
493 	return -ENODEV;
494 }
495 
496 int sas_notify_lldd_dev_found(struct domain_device *dev)
497 {
498 	int res = 0;
499 	struct sas_ha_struct *sas_ha = dev->port->ha;
500 	struct Scsi_Host *shost = sas_ha->core.shost;
501 	struct sas_internal *i = to_sas_internal(shost->transportt);
502 
503 	if (i->dft->lldd_dev_found) {
504 		res = i->dft->lldd_dev_found(dev);
505 		if (res) {
506 			printk("sas: driver on pcidev %s cannot handle "
507 			       "device %llx, error:%d\n",
508 			       pci_name(sas_ha->pcidev),
509 			       SAS_ADDR(dev->sas_addr), res);
510 		}
511 	}
512 	return res;
513 }
514 
515 
516 void sas_notify_lldd_dev_gone(struct domain_device *dev)
517 {
518 	struct sas_ha_struct *sas_ha = dev->port->ha;
519 	struct Scsi_Host *shost = sas_ha->core.shost;
520 	struct sas_internal *i = to_sas_internal(shost->transportt);
521 
522 	if (i->dft->lldd_dev_gone)
523 		i->dft->lldd_dev_gone(dev);
524 }
525 
526 /* ---------- Common/dispatchers ---------- */
527 
528 /**
529  * sas_discover_sata -- discover an STP/SATA domain device
530  * @dev: pointer to struct domain_device of interest
531  *
532  * First we notify the LLDD of this device, so we can send frames to
533  * it.  Then depending on the type of device we call the appropriate
534  * discover functions.  Once device discover is done, we notify the
535  * LLDD so that it can fine-tune its parameters for the device, by
536  * removing it and then adding it.  That is, the second time around,
537  * the driver would have certain fields, that it is looking at, set.
538  * Finally we initialize the kobj so that the device can be added to
539  * the system at registration time.  Devices directly attached to a HA
540  * port, have no parents.  All other devices do, and should have their
541  * "parent" pointer set appropriately before calling this function.
542  */
543 int sas_discover_sata(struct domain_device *dev)
544 {
545 	int res;
546 
547 	sas_get_ata_command_set(dev);
548 
549 	res = sas_notify_lldd_dev_found(dev);
550 	if (res)
551 		goto out_err2;
552 
553 	switch (dev->dev_type) {
554 	case SATA_DEV:
555 		res = sas_discover_sata_dev(dev);
556 		break;
557 	case SATA_PM:
558 		res = sas_discover_sata_pm(dev);
559 		break;
560 	default:
561 		break;
562 	}
563 	if (res)
564 		goto out_err;
565 
566 	sas_notify_lldd_dev_gone(dev);
567 	res = sas_notify_lldd_dev_found(dev);
568 	if (res)
569 		goto out_err2;
570 
571 	res = sas_rphy_add(dev->rphy);
572 	if (res)
573 		goto out_err;
574 
575 	return res;
576 
577 out_err:
578 	sas_notify_lldd_dev_gone(dev);
579 out_err2:
580 	return res;
581 }
582 
583 /**
584  * sas_discover_end_dev -- discover an end device (SSP, etc)
585  * @end: pointer to domain device of interest
586  *
587  * See comment in sas_discover_sata().
588  */
589 int sas_discover_end_dev(struct domain_device *dev)
590 {
591 	int res;
592 
593 	res = sas_notify_lldd_dev_found(dev);
594 	if (res)
595 		goto out_err2;
596 
597 	res = sas_rphy_add(dev->rphy);
598 	if (res)
599 		goto out_err;
600 
601 	return 0;
602 
603 out_err:
604 	sas_notify_lldd_dev_gone(dev);
605 out_err2:
606 	return res;
607 }
608 
609 /* ---------- Device registration and unregistration ---------- */
610 
611 static inline void sas_unregister_common_dev(struct domain_device *dev)
612 {
613 	sas_notify_lldd_dev_gone(dev);
614 	if (!dev->parent)
615 		dev->port->port_dev = NULL;
616 	else
617 		list_del_init(&dev->siblings);
618 	list_del_init(&dev->dev_list_node);
619 }
620 
621 void sas_unregister_dev(struct domain_device *dev)
622 {
623 	if (dev->rphy) {
624 		sas_remove_children(&dev->rphy->dev);
625 		sas_rphy_delete(dev->rphy);
626 		dev->rphy = NULL;
627 	}
628 	if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV) {
629 		/* remove the phys and ports, everything else should be gone */
630 		kfree(dev->ex_dev.ex_phy);
631 		dev->ex_dev.ex_phy = NULL;
632 	}
633 	sas_unregister_common_dev(dev);
634 }
635 
636 void sas_unregister_domain_devices(struct asd_sas_port *port)
637 {
638 	struct domain_device *dev, *n;
639 
640 	list_for_each_entry_safe_reverse(dev,n,&port->dev_list,dev_list_node)
641 		sas_unregister_dev(dev);
642 
643 	port->port->rphy = NULL;
644 
645 }
646 
647 /* ---------- Discovery and Revalidation ---------- */
648 
649 /**
650  * sas_discover_domain -- discover the domain
651  * @port: port to the domain of interest
652  *
653  * NOTE: this process _must_ quit (return) as soon as any connection
654  * errors are encountered.  Connection recovery is done elsewhere.
655  * Discover process only interrogates devices in order to discover the
656  * domain.
657  */
658 static void sas_discover_domain(struct work_struct *work)
659 {
660 	struct domain_device *dev;
661 	int error = 0;
662 	struct sas_discovery_event *ev =
663 		container_of(work, struct sas_discovery_event, work);
664 	struct asd_sas_port *port = ev->port;
665 
666 	sas_begin_event(DISCE_DISCOVER_DOMAIN, &port->disc.disc_event_lock,
667 			&port->disc.pending);
668 
669 	if (port->port_dev)
670 		return;
671 
672 	error = sas_get_port_device(port);
673 	if (error)
674 		return;
675 	dev = port->port_dev;
676 
677 	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
678 		    current->pid);
679 
680 	switch (dev->dev_type) {
681 	case SAS_END_DEV:
682 		error = sas_discover_end_dev(dev);
683 		break;
684 	case EDGE_DEV:
685 	case FANOUT_DEV:
686 		error = sas_discover_root_expander(dev);
687 		break;
688 	case SATA_DEV:
689 	case SATA_PM:
690 		error = sas_discover_sata(dev);
691 		break;
692 	default:
693 		SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
694 		break;
695 	}
696 
697 	if (error) {
698 		sas_rphy_free(dev->rphy);
699 		dev->rphy = NULL;
700 
701 		spin_lock(&port->dev_list_lock);
702 		list_del_init(&dev->dev_list_node);
703 		spin_unlock(&port->dev_list_lock);
704 
705 		kfree(dev); /* not kobject_register-ed yet */
706 		port->port_dev = NULL;
707 	}
708 
709 	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
710 		    current->pid, error);
711 }
712 
713 static void sas_revalidate_domain(struct work_struct *work)
714 {
715 	int res = 0;
716 	struct sas_discovery_event *ev =
717 		container_of(work, struct sas_discovery_event, work);
718 	struct asd_sas_port *port = ev->port;
719 
720 	sas_begin_event(DISCE_REVALIDATE_DOMAIN, &port->disc.disc_event_lock,
721 			&port->disc.pending);
722 
723 	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
724 		    current->pid);
725 	if (port->port_dev)
726 		res = sas_ex_revalidate_domain(port->port_dev);
727 
728 	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
729 		    port->id, current->pid, res);
730 }
731 
732 /* ---------- Events ---------- */
733 
734 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
735 {
736 	struct sas_discovery *disc;
737 
738 	if (!port)
739 		return 0;
740 	disc = &port->disc;
741 
742 	BUG_ON(ev >= DISC_NUM_EVENTS);
743 
744 	sas_queue_event(ev, &disc->disc_event_lock, &disc->pending,
745 			&disc->disc_work[ev].work, port->ha);
746 
747 	return 0;
748 }
749 
750 /**
751  * sas_init_disc -- initialize the discovery struct in the port
752  * @port: pointer to struct port
753  *
754  * Called when the ports are being initialized.
755  */
756 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
757 {
758 	int i;
759 
760 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
761 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
762 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
763 	};
764 
765 	spin_lock_init(&disc->disc_event_lock);
766 	disc->pending = 0;
767 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
768 		INIT_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
769 		disc->disc_work[i].port = port;
770 	}
771 }
772