1 /*
2  * Serial Attached SCSI (SAS) Expander discovery and configuration
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/blkdev.h>
27 #include <linux/slab.h>
28 
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 static int sas_discover_expander(struct domain_device *dev);
36 static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr);
37 static int sas_configure_phy(struct domain_device *dev, int phy_id,
38 			     u8 *sas_addr, int include);
39 static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr);
40 
41 /* ---------- SMP task management ---------- */
42 
43 static void smp_task_timedout(unsigned long _task)
44 {
45 	struct sas_task *task = (void *) _task;
46 	unsigned long flags;
47 
48 	spin_lock_irqsave(&task->task_state_lock, flags);
49 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
50 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
51 	spin_unlock_irqrestore(&task->task_state_lock, flags);
52 
53 	complete(&task->completion);
54 }
55 
56 static void smp_task_done(struct sas_task *task)
57 {
58 	if (!del_timer(&task->timer))
59 		return;
60 	complete(&task->completion);
61 }
62 
63 /* Give it some long enough timeout. In seconds. */
64 #define SMP_TIMEOUT 10
65 
66 static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
67 			    void *resp, int resp_size)
68 {
69 	int res, retry;
70 	struct sas_task *task = NULL;
71 	struct sas_internal *i =
72 		to_sas_internal(dev->port->ha->core.shost->transportt);
73 
74 	for (retry = 0; retry < 3; retry++) {
75 		task = sas_alloc_task(GFP_KERNEL);
76 		if (!task)
77 			return -ENOMEM;
78 
79 		task->dev = dev;
80 		task->task_proto = dev->tproto;
81 		sg_init_one(&task->smp_task.smp_req, req, req_size);
82 		sg_init_one(&task->smp_task.smp_resp, resp, resp_size);
83 
84 		task->task_done = smp_task_done;
85 
86 		task->timer.data = (unsigned long) task;
87 		task->timer.function = smp_task_timedout;
88 		task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
89 		add_timer(&task->timer);
90 
91 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
92 
93 		if (res) {
94 			del_timer(&task->timer);
95 			SAS_DPRINTK("executing SMP task failed:%d\n", res);
96 			goto ex_err;
97 		}
98 
99 		wait_for_completion(&task->completion);
100 		res = -ECOMM;
101 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
102 			SAS_DPRINTK("smp task timed out or aborted\n");
103 			i->dft->lldd_abort_task(task);
104 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
105 				SAS_DPRINTK("SMP task aborted and not done\n");
106 				goto ex_err;
107 			}
108 		}
109 		if (task->task_status.resp == SAS_TASK_COMPLETE &&
110 		    task->task_status.stat == SAM_STAT_GOOD) {
111 			res = 0;
112 			break;
113 		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
114 		      task->task_status.stat == SAS_DATA_UNDERRUN) {
115 			/* no error, but return the number of bytes of
116 			 * underrun */
117 			res = task->task_status.residual;
118 			break;
119 		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
120 		      task->task_status.stat == SAS_DATA_OVERRUN) {
121 			res = -EMSGSIZE;
122 			break;
123 		} else {
124 			SAS_DPRINTK("%s: task to dev %016llx response: 0x%x "
125 				    "status 0x%x\n", __func__,
126 				    SAS_ADDR(dev->sas_addr),
127 				    task->task_status.resp,
128 				    task->task_status.stat);
129 			sas_free_task(task);
130 			task = NULL;
131 		}
132 	}
133 ex_err:
134 	BUG_ON(retry == 3 && task != NULL);
135 	if (task != NULL) {
136 		sas_free_task(task);
137 	}
138 	return res;
139 }
140 
141 /* ---------- Allocations ---------- */
142 
143 static inline void *alloc_smp_req(int size)
144 {
145 	u8 *p = kzalloc(size, GFP_KERNEL);
146 	if (p)
147 		p[0] = SMP_REQUEST;
148 	return p;
149 }
150 
151 static inline void *alloc_smp_resp(int size)
152 {
153 	return kzalloc(size, GFP_KERNEL);
154 }
155 
156 /* ---------- Expander configuration ---------- */
157 
158 static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
159 			   void *disc_resp)
160 {
161 	struct expander_device *ex = &dev->ex_dev;
162 	struct ex_phy *phy = &ex->ex_phy[phy_id];
163 	struct smp_resp *resp = disc_resp;
164 	struct discover_resp *dr = &resp->disc;
165 	struct sas_rphy *rphy = dev->rphy;
166 	int rediscover = (phy->phy != NULL);
167 
168 	if (!rediscover) {
169 		phy->phy = sas_phy_alloc(&rphy->dev, phy_id);
170 
171 		/* FIXME: error_handling */
172 		BUG_ON(!phy->phy);
173 	}
174 
175 	switch (resp->result) {
176 	case SMP_RESP_PHY_VACANT:
177 		phy->phy_state = PHY_VACANT;
178 		break;
179 	default:
180 		phy->phy_state = PHY_NOT_PRESENT;
181 		break;
182 	case SMP_RESP_FUNC_ACC:
183 		phy->phy_state = PHY_EMPTY; /* do not know yet */
184 		break;
185 	}
186 
187 	phy->phy_id = phy_id;
188 	phy->attached_dev_type = dr->attached_dev_type;
189 	phy->linkrate = dr->linkrate;
190 	phy->attached_sata_host = dr->attached_sata_host;
191 	phy->attached_sata_dev  = dr->attached_sata_dev;
192 	phy->attached_sata_ps   = dr->attached_sata_ps;
193 	phy->attached_iproto = dr->iproto << 1;
194 	phy->attached_tproto = dr->tproto << 1;
195 	memcpy(phy->attached_sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE);
196 	phy->attached_phy_id = dr->attached_phy_id;
197 	phy->phy_change_count = dr->change_count;
198 	phy->routing_attr = dr->routing_attr;
199 	phy->virtual = dr->virtual;
200 	phy->last_da_index = -1;
201 
202 	phy->phy->identify.initiator_port_protocols = phy->attached_iproto;
203 	phy->phy->identify.target_port_protocols = phy->attached_tproto;
204 	phy->phy->identify.phy_identifier = phy_id;
205 	phy->phy->minimum_linkrate_hw = dr->hmin_linkrate;
206 	phy->phy->maximum_linkrate_hw = dr->hmax_linkrate;
207 	phy->phy->minimum_linkrate = dr->pmin_linkrate;
208 	phy->phy->maximum_linkrate = dr->pmax_linkrate;
209 	phy->phy->negotiated_linkrate = phy->linkrate;
210 
211 	if (!rediscover)
212 		if (sas_phy_add(phy->phy)) {
213 			sas_phy_free(phy->phy);
214 			return;
215 		}
216 
217 	SAS_DPRINTK("ex %016llx phy%02d:%c attached: %016llx\n",
218 		    SAS_ADDR(dev->sas_addr), phy->phy_id,
219 		    phy->routing_attr == TABLE_ROUTING ? 'T' :
220 		    phy->routing_attr == DIRECT_ROUTING ? 'D' :
221 		    phy->routing_attr == SUBTRACTIVE_ROUTING ? 'S' : '?',
222 		    SAS_ADDR(phy->attached_sas_addr));
223 
224 	return;
225 }
226 
227 #define DISCOVER_REQ_SIZE  16
228 #define DISCOVER_RESP_SIZE 56
229 
230 static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
231 				      u8 *disc_resp, int single)
232 {
233 	int i, res;
234 
235 	disc_req[9] = single;
236 	for (i = 1 ; i < 3; i++) {
237 		struct discover_resp *dr;
238 
239 		res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
240 				       disc_resp, DISCOVER_RESP_SIZE);
241 		if (res)
242 			return res;
243 		/* This is detecting a failure to transmit inital
244 		 * dev to host FIS as described in section G.5 of
245 		 * sas-2 r 04b */
246 		dr = &((struct smp_resp *)disc_resp)->disc;
247 		if (!(dr->attached_dev_type == 0 &&
248 		      dr->attached_sata_dev))
249 			break;
250 		/* In order to generate the dev to host FIS, we
251 		 * send a link reset to the expander port */
252 		sas_smp_phy_control(dev, single, PHY_FUNC_LINK_RESET, NULL);
253 		/* Wait for the reset to trigger the negotiation */
254 		msleep(500);
255 	}
256 	sas_set_ex_phy(dev, single, disc_resp);
257 	return 0;
258 }
259 
260 static int sas_ex_phy_discover(struct domain_device *dev, int single)
261 {
262 	struct expander_device *ex = &dev->ex_dev;
263 	int  res = 0;
264 	u8   *disc_req;
265 	u8   *disc_resp;
266 
267 	disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
268 	if (!disc_req)
269 		return -ENOMEM;
270 
271 	disc_resp = alloc_smp_req(DISCOVER_RESP_SIZE);
272 	if (!disc_resp) {
273 		kfree(disc_req);
274 		return -ENOMEM;
275 	}
276 
277 	disc_req[1] = SMP_DISCOVER;
278 
279 	if (0 <= single && single < ex->num_phys) {
280 		res = sas_ex_phy_discover_helper(dev, disc_req, disc_resp, single);
281 	} else {
282 		int i;
283 
284 		for (i = 0; i < ex->num_phys; i++) {
285 			res = sas_ex_phy_discover_helper(dev, disc_req,
286 							 disc_resp, i);
287 			if (res)
288 				goto out_err;
289 		}
290 	}
291 out_err:
292 	kfree(disc_resp);
293 	kfree(disc_req);
294 	return res;
295 }
296 
297 static int sas_expander_discover(struct domain_device *dev)
298 {
299 	struct expander_device *ex = &dev->ex_dev;
300 	int res = -ENOMEM;
301 
302 	ex->ex_phy = kzalloc(sizeof(*ex->ex_phy)*ex->num_phys, GFP_KERNEL);
303 	if (!ex->ex_phy)
304 		return -ENOMEM;
305 
306 	res = sas_ex_phy_discover(dev, -1);
307 	if (res)
308 		goto out_err;
309 
310 	return 0;
311  out_err:
312 	kfree(ex->ex_phy);
313 	ex->ex_phy = NULL;
314 	return res;
315 }
316 
317 #define MAX_EXPANDER_PHYS 128
318 
319 static void ex_assign_report_general(struct domain_device *dev,
320 					    struct smp_resp *resp)
321 {
322 	struct report_general_resp *rg = &resp->rg;
323 
324 	dev->ex_dev.ex_change_count = be16_to_cpu(rg->change_count);
325 	dev->ex_dev.max_route_indexes = be16_to_cpu(rg->route_indexes);
326 	dev->ex_dev.num_phys = min(rg->num_phys, (u8)MAX_EXPANDER_PHYS);
327 	dev->ex_dev.conf_route_table = rg->conf_route_table;
328 	dev->ex_dev.configuring = rg->configuring;
329 	memcpy(dev->ex_dev.enclosure_logical_id, rg->enclosure_logical_id, 8);
330 }
331 
332 #define RG_REQ_SIZE   8
333 #define RG_RESP_SIZE 32
334 
335 static int sas_ex_general(struct domain_device *dev)
336 {
337 	u8 *rg_req;
338 	struct smp_resp *rg_resp;
339 	int res;
340 	int i;
341 
342 	rg_req = alloc_smp_req(RG_REQ_SIZE);
343 	if (!rg_req)
344 		return -ENOMEM;
345 
346 	rg_resp = alloc_smp_resp(RG_RESP_SIZE);
347 	if (!rg_resp) {
348 		kfree(rg_req);
349 		return -ENOMEM;
350 	}
351 
352 	rg_req[1] = SMP_REPORT_GENERAL;
353 
354 	for (i = 0; i < 5; i++) {
355 		res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
356 				       RG_RESP_SIZE);
357 
358 		if (res) {
359 			SAS_DPRINTK("RG to ex %016llx failed:0x%x\n",
360 				    SAS_ADDR(dev->sas_addr), res);
361 			goto out;
362 		} else if (rg_resp->result != SMP_RESP_FUNC_ACC) {
363 			SAS_DPRINTK("RG:ex %016llx returned SMP result:0x%x\n",
364 				    SAS_ADDR(dev->sas_addr), rg_resp->result);
365 			res = rg_resp->result;
366 			goto out;
367 		}
368 
369 		ex_assign_report_general(dev, rg_resp);
370 
371 		if (dev->ex_dev.configuring) {
372 			SAS_DPRINTK("RG: ex %llx self-configuring...\n",
373 				    SAS_ADDR(dev->sas_addr));
374 			schedule_timeout_interruptible(5*HZ);
375 		} else
376 			break;
377 	}
378 out:
379 	kfree(rg_req);
380 	kfree(rg_resp);
381 	return res;
382 }
383 
384 static void ex_assign_manuf_info(struct domain_device *dev, void
385 					*_mi_resp)
386 {
387 	u8 *mi_resp = _mi_resp;
388 	struct sas_rphy *rphy = dev->rphy;
389 	struct sas_expander_device *edev = rphy_to_expander_device(rphy);
390 
391 	memcpy(edev->vendor_id, mi_resp + 12, SAS_EXPANDER_VENDOR_ID_LEN);
392 	memcpy(edev->product_id, mi_resp + 20, SAS_EXPANDER_PRODUCT_ID_LEN);
393 	memcpy(edev->product_rev, mi_resp + 36,
394 	       SAS_EXPANDER_PRODUCT_REV_LEN);
395 
396 	if (mi_resp[8] & 1) {
397 		memcpy(edev->component_vendor_id, mi_resp + 40,
398 		       SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN);
399 		edev->component_id = mi_resp[48] << 8 | mi_resp[49];
400 		edev->component_revision_id = mi_resp[50];
401 	}
402 }
403 
404 #define MI_REQ_SIZE   8
405 #define MI_RESP_SIZE 64
406 
407 static int sas_ex_manuf_info(struct domain_device *dev)
408 {
409 	u8 *mi_req;
410 	u8 *mi_resp;
411 	int res;
412 
413 	mi_req = alloc_smp_req(MI_REQ_SIZE);
414 	if (!mi_req)
415 		return -ENOMEM;
416 
417 	mi_resp = alloc_smp_resp(MI_RESP_SIZE);
418 	if (!mi_resp) {
419 		kfree(mi_req);
420 		return -ENOMEM;
421 	}
422 
423 	mi_req[1] = SMP_REPORT_MANUF_INFO;
424 
425 	res = smp_execute_task(dev, mi_req, MI_REQ_SIZE, mi_resp,MI_RESP_SIZE);
426 	if (res) {
427 		SAS_DPRINTK("MI: ex %016llx failed:0x%x\n",
428 			    SAS_ADDR(dev->sas_addr), res);
429 		goto out;
430 	} else if (mi_resp[2] != SMP_RESP_FUNC_ACC) {
431 		SAS_DPRINTK("MI ex %016llx returned SMP result:0x%x\n",
432 			    SAS_ADDR(dev->sas_addr), mi_resp[2]);
433 		goto out;
434 	}
435 
436 	ex_assign_manuf_info(dev, mi_resp);
437 out:
438 	kfree(mi_req);
439 	kfree(mi_resp);
440 	return res;
441 }
442 
443 #define PC_REQ_SIZE  44
444 #define PC_RESP_SIZE 8
445 
446 int sas_smp_phy_control(struct domain_device *dev, int phy_id,
447 			enum phy_func phy_func,
448 			struct sas_phy_linkrates *rates)
449 {
450 	u8 *pc_req;
451 	u8 *pc_resp;
452 	int res;
453 
454 	pc_req = alloc_smp_req(PC_REQ_SIZE);
455 	if (!pc_req)
456 		return -ENOMEM;
457 
458 	pc_resp = alloc_smp_resp(PC_RESP_SIZE);
459 	if (!pc_resp) {
460 		kfree(pc_req);
461 		return -ENOMEM;
462 	}
463 
464 	pc_req[1] = SMP_PHY_CONTROL;
465 	pc_req[9] = phy_id;
466 	pc_req[10]= phy_func;
467 	if (rates) {
468 		pc_req[32] = rates->minimum_linkrate << 4;
469 		pc_req[33] = rates->maximum_linkrate << 4;
470 	}
471 
472 	res = smp_execute_task(dev, pc_req, PC_REQ_SIZE, pc_resp,PC_RESP_SIZE);
473 
474 	kfree(pc_resp);
475 	kfree(pc_req);
476 	return res;
477 }
478 
479 static void sas_ex_disable_phy(struct domain_device *dev, int phy_id)
480 {
481 	struct expander_device *ex = &dev->ex_dev;
482 	struct ex_phy *phy = &ex->ex_phy[phy_id];
483 
484 	sas_smp_phy_control(dev, phy_id, PHY_FUNC_DISABLE, NULL);
485 	phy->linkrate = SAS_PHY_DISABLED;
486 }
487 
488 static void sas_ex_disable_port(struct domain_device *dev, u8 *sas_addr)
489 {
490 	struct expander_device *ex = &dev->ex_dev;
491 	int i;
492 
493 	for (i = 0; i < ex->num_phys; i++) {
494 		struct ex_phy *phy = &ex->ex_phy[i];
495 
496 		if (phy->phy_state == PHY_VACANT ||
497 		    phy->phy_state == PHY_NOT_PRESENT)
498 			continue;
499 
500 		if (SAS_ADDR(phy->attached_sas_addr) == SAS_ADDR(sas_addr))
501 			sas_ex_disable_phy(dev, i);
502 	}
503 }
504 
505 static int sas_dev_present_in_domain(struct asd_sas_port *port,
506 					    u8 *sas_addr)
507 {
508 	struct domain_device *dev;
509 
510 	if (SAS_ADDR(port->sas_addr) == SAS_ADDR(sas_addr))
511 		return 1;
512 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
513 		if (SAS_ADDR(dev->sas_addr) == SAS_ADDR(sas_addr))
514 			return 1;
515 	}
516 	return 0;
517 }
518 
519 #define RPEL_REQ_SIZE	16
520 #define RPEL_RESP_SIZE	32
521 int sas_smp_get_phy_events(struct sas_phy *phy)
522 {
523 	int res;
524 	u8 *req;
525 	u8 *resp;
526 	struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
527 	struct domain_device *dev = sas_find_dev_by_rphy(rphy);
528 
529 	req = alloc_smp_req(RPEL_REQ_SIZE);
530 	if (!req)
531 		return -ENOMEM;
532 
533 	resp = alloc_smp_resp(RPEL_RESP_SIZE);
534 	if (!resp) {
535 		kfree(req);
536 		return -ENOMEM;
537 	}
538 
539 	req[1] = SMP_REPORT_PHY_ERR_LOG;
540 	req[9] = phy->number;
541 
542 	res = smp_execute_task(dev, req, RPEL_REQ_SIZE,
543 			            resp, RPEL_RESP_SIZE);
544 
545 	if (!res)
546 		goto out;
547 
548 	phy->invalid_dword_count = scsi_to_u32(&resp[12]);
549 	phy->running_disparity_error_count = scsi_to_u32(&resp[16]);
550 	phy->loss_of_dword_sync_count = scsi_to_u32(&resp[20]);
551 	phy->phy_reset_problem_count = scsi_to_u32(&resp[24]);
552 
553  out:
554 	kfree(resp);
555 	return res;
556 
557 }
558 
559 #ifdef CONFIG_SCSI_SAS_ATA
560 
561 #define RPS_REQ_SIZE  16
562 #define RPS_RESP_SIZE 60
563 
564 static int sas_get_report_phy_sata(struct domain_device *dev,
565 					  int phy_id,
566 					  struct smp_resp *rps_resp)
567 {
568 	int res;
569 	u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE);
570 	u8 *resp = (u8 *)rps_resp;
571 
572 	if (!rps_req)
573 		return -ENOMEM;
574 
575 	rps_req[1] = SMP_REPORT_PHY_SATA;
576 	rps_req[9] = phy_id;
577 
578 	res = smp_execute_task(dev, rps_req, RPS_REQ_SIZE,
579 			            rps_resp, RPS_RESP_SIZE);
580 
581 	/* 0x34 is the FIS type for the D2H fis.  There's a potential
582 	 * standards cockup here.  sas-2 explicitly specifies the FIS
583 	 * should be encoded so that FIS type is in resp[24].
584 	 * However, some expanders endian reverse this.  Undo the
585 	 * reversal here */
586 	if (!res && resp[27] == 0x34 && resp[24] != 0x34) {
587 		int i;
588 
589 		for (i = 0; i < 5; i++) {
590 			int j = 24 + (i*4);
591 			u8 a, b;
592 			a = resp[j + 0];
593 			b = resp[j + 1];
594 			resp[j + 0] = resp[j + 3];
595 			resp[j + 1] = resp[j + 2];
596 			resp[j + 2] = b;
597 			resp[j + 3] = a;
598 		}
599 	}
600 
601 	kfree(rps_req);
602 	return res;
603 }
604 #endif
605 
606 static void sas_ex_get_linkrate(struct domain_device *parent,
607 				       struct domain_device *child,
608 				       struct ex_phy *parent_phy)
609 {
610 	struct expander_device *parent_ex = &parent->ex_dev;
611 	struct sas_port *port;
612 	int i;
613 
614 	child->pathways = 0;
615 
616 	port = parent_phy->port;
617 
618 	for (i = 0; i < parent_ex->num_phys; i++) {
619 		struct ex_phy *phy = &parent_ex->ex_phy[i];
620 
621 		if (phy->phy_state == PHY_VACANT ||
622 		    phy->phy_state == PHY_NOT_PRESENT)
623 			continue;
624 
625 		if (SAS_ADDR(phy->attached_sas_addr) ==
626 		    SAS_ADDR(child->sas_addr)) {
627 
628 			child->min_linkrate = min(parent->min_linkrate,
629 						  phy->linkrate);
630 			child->max_linkrate = max(parent->max_linkrate,
631 						  phy->linkrate);
632 			child->pathways++;
633 			sas_port_add_phy(port, phy->phy);
634 		}
635 	}
636 	child->linkrate = min(parent_phy->linkrate, child->max_linkrate);
637 	child->pathways = min(child->pathways, parent->pathways);
638 }
639 
640 static struct domain_device *sas_ex_discover_end_dev(
641 	struct domain_device *parent, int phy_id)
642 {
643 	struct expander_device *parent_ex = &parent->ex_dev;
644 	struct ex_phy *phy = &parent_ex->ex_phy[phy_id];
645 	struct domain_device *child = NULL;
646 	struct sas_rphy *rphy;
647 	int res;
648 
649 	if (phy->attached_sata_host || phy->attached_sata_ps)
650 		return NULL;
651 
652 	child = kzalloc(sizeof(*child), GFP_KERNEL);
653 	if (!child)
654 		return NULL;
655 
656 	child->parent = parent;
657 	child->port   = parent->port;
658 	child->iproto = phy->attached_iproto;
659 	memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
660 	sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
661 	if (!phy->port) {
662 		phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
663 		if (unlikely(!phy->port))
664 			goto out_err;
665 		if (unlikely(sas_port_add(phy->port) != 0)) {
666 			sas_port_free(phy->port);
667 			goto out_err;
668 		}
669 	}
670 	sas_ex_get_linkrate(parent, child, phy);
671 
672 #ifdef CONFIG_SCSI_SAS_ATA
673 	if ((phy->attached_tproto & SAS_PROTOCOL_STP) || phy->attached_sata_dev) {
674 		child->dev_type = SATA_DEV;
675 		if (phy->attached_tproto & SAS_PROTOCOL_STP)
676 			child->tproto = phy->attached_tproto;
677 		if (phy->attached_sata_dev)
678 			child->tproto |= SATA_DEV;
679 		res = sas_get_report_phy_sata(parent, phy_id,
680 					      &child->sata_dev.rps_resp);
681 		if (res) {
682 			SAS_DPRINTK("report phy sata to %016llx:0x%x returned "
683 				    "0x%x\n", SAS_ADDR(parent->sas_addr),
684 				    phy_id, res);
685 			goto out_free;
686 		}
687 		memcpy(child->frame_rcvd, &child->sata_dev.rps_resp.rps.fis,
688 		       sizeof(struct dev_to_host_fis));
689 
690 		rphy = sas_end_device_alloc(phy->port);
691 		if (unlikely(!rphy))
692 			goto out_free;
693 
694 		sas_init_dev(child);
695 
696 		child->rphy = rphy;
697 
698 		spin_lock_irq(&parent->port->dev_list_lock);
699 		list_add_tail(&child->dev_list_node, &parent->port->dev_list);
700 		spin_unlock_irq(&parent->port->dev_list_lock);
701 
702 		res = sas_discover_sata(child);
703 		if (res) {
704 			SAS_DPRINTK("sas_discover_sata() for device %16llx at "
705 				    "%016llx:0x%x returned 0x%x\n",
706 				    SAS_ADDR(child->sas_addr),
707 				    SAS_ADDR(parent->sas_addr), phy_id, res);
708 			goto out_list_del;
709 		}
710 	} else
711 #endif
712 	  if (phy->attached_tproto & SAS_PROTOCOL_SSP) {
713 		child->dev_type = SAS_END_DEV;
714 		rphy = sas_end_device_alloc(phy->port);
715 		/* FIXME: error handling */
716 		if (unlikely(!rphy))
717 			goto out_free;
718 		child->tproto = phy->attached_tproto;
719 		sas_init_dev(child);
720 
721 		child->rphy = rphy;
722 		sas_fill_in_rphy(child, rphy);
723 
724 		spin_lock_irq(&parent->port->dev_list_lock);
725 		list_add_tail(&child->dev_list_node, &parent->port->dev_list);
726 		spin_unlock_irq(&parent->port->dev_list_lock);
727 
728 		res = sas_discover_end_dev(child);
729 		if (res) {
730 			SAS_DPRINTK("sas_discover_end_dev() for device %16llx "
731 				    "at %016llx:0x%x returned 0x%x\n",
732 				    SAS_ADDR(child->sas_addr),
733 				    SAS_ADDR(parent->sas_addr), phy_id, res);
734 			goto out_list_del;
735 		}
736 	} else {
737 		SAS_DPRINTK("target proto 0x%x at %016llx:0x%x not handled\n",
738 			    phy->attached_tproto, SAS_ADDR(parent->sas_addr),
739 			    phy_id);
740 		goto out_free;
741 	}
742 
743 	list_add_tail(&child->siblings, &parent_ex->children);
744 	return child;
745 
746  out_list_del:
747 	sas_rphy_free(child->rphy);
748 	child->rphy = NULL;
749 	list_del(&child->dev_list_node);
750  out_free:
751 	sas_port_delete(phy->port);
752  out_err:
753 	phy->port = NULL;
754 	kfree(child);
755 	return NULL;
756 }
757 
758 /* See if this phy is part of a wide port */
759 static int sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
760 {
761 	struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
762 	int i;
763 
764 	for (i = 0; i < parent->ex_dev.num_phys; i++) {
765 		struct ex_phy *ephy = &parent->ex_dev.ex_phy[i];
766 
767 		if (ephy == phy)
768 			continue;
769 
770 		if (!memcmp(phy->attached_sas_addr, ephy->attached_sas_addr,
771 			    SAS_ADDR_SIZE) && ephy->port) {
772 			sas_port_add_phy(ephy->port, phy->phy);
773 			phy->port = ephy->port;
774 			phy->phy_state = PHY_DEVICE_DISCOVERED;
775 			return 0;
776 		}
777 	}
778 
779 	return -ENODEV;
780 }
781 
782 static struct domain_device *sas_ex_discover_expander(
783 	struct domain_device *parent, int phy_id)
784 {
785 	struct sas_expander_device *parent_ex = rphy_to_expander_device(parent->rphy);
786 	struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
787 	struct domain_device *child = NULL;
788 	struct sas_rphy *rphy;
789 	struct sas_expander_device *edev;
790 	struct asd_sas_port *port;
791 	int res;
792 
793 	if (phy->routing_attr == DIRECT_ROUTING) {
794 		SAS_DPRINTK("ex %016llx:0x%x:D <--> ex %016llx:0x%x is not "
795 			    "allowed\n",
796 			    SAS_ADDR(parent->sas_addr), phy_id,
797 			    SAS_ADDR(phy->attached_sas_addr),
798 			    phy->attached_phy_id);
799 		return NULL;
800 	}
801 	child = kzalloc(sizeof(*child), GFP_KERNEL);
802 	if (!child)
803 		return NULL;
804 
805 	phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
806 	/* FIXME: better error handling */
807 	BUG_ON(sas_port_add(phy->port) != 0);
808 
809 
810 	switch (phy->attached_dev_type) {
811 	case EDGE_DEV:
812 		rphy = sas_expander_alloc(phy->port,
813 					  SAS_EDGE_EXPANDER_DEVICE);
814 		break;
815 	case FANOUT_DEV:
816 		rphy = sas_expander_alloc(phy->port,
817 					  SAS_FANOUT_EXPANDER_DEVICE);
818 		break;
819 	default:
820 		rphy = NULL;	/* shut gcc up */
821 		BUG();
822 	}
823 	port = parent->port;
824 	child->rphy = rphy;
825 	edev = rphy_to_expander_device(rphy);
826 	child->dev_type = phy->attached_dev_type;
827 	child->parent = parent;
828 	child->port = port;
829 	child->iproto = phy->attached_iproto;
830 	child->tproto = phy->attached_tproto;
831 	memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
832 	sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
833 	sas_ex_get_linkrate(parent, child, phy);
834 	edev->level = parent_ex->level + 1;
835 	parent->port->disc.max_level = max(parent->port->disc.max_level,
836 					   edev->level);
837 	sas_init_dev(child);
838 	sas_fill_in_rphy(child, rphy);
839 	sas_rphy_add(rphy);
840 
841 	spin_lock_irq(&parent->port->dev_list_lock);
842 	list_add_tail(&child->dev_list_node, &parent->port->dev_list);
843 	spin_unlock_irq(&parent->port->dev_list_lock);
844 
845 	res = sas_discover_expander(child);
846 	if (res) {
847 		kfree(child);
848 		return NULL;
849 	}
850 	list_add_tail(&child->siblings, &parent->ex_dev.children);
851 	return child;
852 }
853 
854 static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
855 {
856 	struct expander_device *ex = &dev->ex_dev;
857 	struct ex_phy *ex_phy = &ex->ex_phy[phy_id];
858 	struct domain_device *child = NULL;
859 	int res = 0;
860 
861 	/* Phy state */
862 	if (ex_phy->linkrate == SAS_SATA_SPINUP_HOLD) {
863 		if (!sas_smp_phy_control(dev, phy_id, PHY_FUNC_LINK_RESET, NULL))
864 			res = sas_ex_phy_discover(dev, phy_id);
865 		if (res)
866 			return res;
867 	}
868 
869 	/* Parent and domain coherency */
870 	if (!dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
871 			     SAS_ADDR(dev->port->sas_addr))) {
872 		sas_add_parent_port(dev, phy_id);
873 		return 0;
874 	}
875 	if (dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
876 			    SAS_ADDR(dev->parent->sas_addr))) {
877 		sas_add_parent_port(dev, phy_id);
878 		if (ex_phy->routing_attr == TABLE_ROUTING)
879 			sas_configure_phy(dev, phy_id, dev->port->sas_addr, 1);
880 		return 0;
881 	}
882 
883 	if (sas_dev_present_in_domain(dev->port, ex_phy->attached_sas_addr))
884 		sas_ex_disable_port(dev, ex_phy->attached_sas_addr);
885 
886 	if (ex_phy->attached_dev_type == NO_DEVICE) {
887 		if (ex_phy->routing_attr == DIRECT_ROUTING) {
888 			memset(ex_phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
889 			sas_configure_routing(dev, ex_phy->attached_sas_addr);
890 		}
891 		return 0;
892 	} else if (ex_phy->linkrate == SAS_LINK_RATE_UNKNOWN)
893 		return 0;
894 
895 	if (ex_phy->attached_dev_type != SAS_END_DEV &&
896 	    ex_phy->attached_dev_type != FANOUT_DEV &&
897 	    ex_phy->attached_dev_type != EDGE_DEV) {
898 		SAS_DPRINTK("unknown device type(0x%x) attached to ex %016llx "
899 			    "phy 0x%x\n", ex_phy->attached_dev_type,
900 			    SAS_ADDR(dev->sas_addr),
901 			    phy_id);
902 		return 0;
903 	}
904 
905 	res = sas_configure_routing(dev, ex_phy->attached_sas_addr);
906 	if (res) {
907 		SAS_DPRINTK("configure routing for dev %016llx "
908 			    "reported 0x%x. Forgotten\n",
909 			    SAS_ADDR(ex_phy->attached_sas_addr), res);
910 		sas_disable_routing(dev, ex_phy->attached_sas_addr);
911 		return res;
912 	}
913 
914 	res = sas_ex_join_wide_port(dev, phy_id);
915 	if (!res) {
916 		SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
917 			    phy_id, SAS_ADDR(ex_phy->attached_sas_addr));
918 		return res;
919 	}
920 
921 	switch (ex_phy->attached_dev_type) {
922 	case SAS_END_DEV:
923 		child = sas_ex_discover_end_dev(dev, phy_id);
924 		break;
925 	case FANOUT_DEV:
926 		if (SAS_ADDR(dev->port->disc.fanout_sas_addr)) {
927 			SAS_DPRINTK("second fanout expander %016llx phy 0x%x "
928 				    "attached to ex %016llx phy 0x%x\n",
929 				    SAS_ADDR(ex_phy->attached_sas_addr),
930 				    ex_phy->attached_phy_id,
931 				    SAS_ADDR(dev->sas_addr),
932 				    phy_id);
933 			sas_ex_disable_phy(dev, phy_id);
934 			break;
935 		} else
936 			memcpy(dev->port->disc.fanout_sas_addr,
937 			       ex_phy->attached_sas_addr, SAS_ADDR_SIZE);
938 		/* fallthrough */
939 	case EDGE_DEV:
940 		child = sas_ex_discover_expander(dev, phy_id);
941 		break;
942 	default:
943 		break;
944 	}
945 
946 	if (child) {
947 		int i;
948 
949 		for (i = 0; i < ex->num_phys; i++) {
950 			if (ex->ex_phy[i].phy_state == PHY_VACANT ||
951 			    ex->ex_phy[i].phy_state == PHY_NOT_PRESENT)
952 				continue;
953 			/*
954 			 * Due to races, the phy might not get added to the
955 			 * wide port, so we add the phy to the wide port here.
956 			 */
957 			if (SAS_ADDR(ex->ex_phy[i].attached_sas_addr) ==
958 			    SAS_ADDR(child->sas_addr)) {
959 				ex->ex_phy[i].phy_state= PHY_DEVICE_DISCOVERED;
960 				res = sas_ex_join_wide_port(dev, i);
961 				if (!res)
962 					SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
963 						    i, SAS_ADDR(ex->ex_phy[i].attached_sas_addr));
964 
965 			}
966 		}
967 	}
968 
969 	return res;
970 }
971 
972 static int sas_find_sub_addr(struct domain_device *dev, u8 *sub_addr)
973 {
974 	struct expander_device *ex = &dev->ex_dev;
975 	int i;
976 
977 	for (i = 0; i < ex->num_phys; i++) {
978 		struct ex_phy *phy = &ex->ex_phy[i];
979 
980 		if (phy->phy_state == PHY_VACANT ||
981 		    phy->phy_state == PHY_NOT_PRESENT)
982 			continue;
983 
984 		if ((phy->attached_dev_type == EDGE_DEV ||
985 		     phy->attached_dev_type == FANOUT_DEV) &&
986 		    phy->routing_attr == SUBTRACTIVE_ROUTING) {
987 
988 			memcpy(sub_addr, phy->attached_sas_addr,SAS_ADDR_SIZE);
989 
990 			return 1;
991 		}
992 	}
993 	return 0;
994 }
995 
996 static int sas_check_level_subtractive_boundary(struct domain_device *dev)
997 {
998 	struct expander_device *ex = &dev->ex_dev;
999 	struct domain_device *child;
1000 	u8 sub_addr[8] = {0, };
1001 
1002 	list_for_each_entry(child, &ex->children, siblings) {
1003 		if (child->dev_type != EDGE_DEV &&
1004 		    child->dev_type != FANOUT_DEV)
1005 			continue;
1006 		if (sub_addr[0] == 0) {
1007 			sas_find_sub_addr(child, sub_addr);
1008 			continue;
1009 		} else {
1010 			u8 s2[8];
1011 
1012 			if (sas_find_sub_addr(child, s2) &&
1013 			    (SAS_ADDR(sub_addr) != SAS_ADDR(s2))) {
1014 
1015 				SAS_DPRINTK("ex %016llx->%016llx-?->%016llx "
1016 					    "diverges from subtractive "
1017 					    "boundary %016llx\n",
1018 					    SAS_ADDR(dev->sas_addr),
1019 					    SAS_ADDR(child->sas_addr),
1020 					    SAS_ADDR(s2),
1021 					    SAS_ADDR(sub_addr));
1022 
1023 				sas_ex_disable_port(child, s2);
1024 			}
1025 		}
1026 	}
1027 	return 0;
1028 }
1029 /**
1030  * sas_ex_discover_devices -- discover devices attached to this expander
1031  * dev: pointer to the expander domain device
1032  * single: if you want to do a single phy, else set to -1;
1033  *
1034  * Configure this expander for use with its devices and register the
1035  * devices of this expander.
1036  */
1037 static int sas_ex_discover_devices(struct domain_device *dev, int single)
1038 {
1039 	struct expander_device *ex = &dev->ex_dev;
1040 	int i = 0, end = ex->num_phys;
1041 	int res = 0;
1042 
1043 	if (0 <= single && single < end) {
1044 		i = single;
1045 		end = i+1;
1046 	}
1047 
1048 	for ( ; i < end; i++) {
1049 		struct ex_phy *ex_phy = &ex->ex_phy[i];
1050 
1051 		if (ex_phy->phy_state == PHY_VACANT ||
1052 		    ex_phy->phy_state == PHY_NOT_PRESENT ||
1053 		    ex_phy->phy_state == PHY_DEVICE_DISCOVERED)
1054 			continue;
1055 
1056 		switch (ex_phy->linkrate) {
1057 		case SAS_PHY_DISABLED:
1058 		case SAS_PHY_RESET_PROBLEM:
1059 		case SAS_SATA_PORT_SELECTOR:
1060 			continue;
1061 		default:
1062 			res = sas_ex_discover_dev(dev, i);
1063 			if (res)
1064 				break;
1065 			continue;
1066 		}
1067 	}
1068 
1069 	if (!res)
1070 		sas_check_level_subtractive_boundary(dev);
1071 
1072 	return res;
1073 }
1074 
1075 static int sas_check_ex_subtractive_boundary(struct domain_device *dev)
1076 {
1077 	struct expander_device *ex = &dev->ex_dev;
1078 	int i;
1079 	u8  *sub_sas_addr = NULL;
1080 
1081 	if (dev->dev_type != EDGE_DEV)
1082 		return 0;
1083 
1084 	for (i = 0; i < ex->num_phys; i++) {
1085 		struct ex_phy *phy = &ex->ex_phy[i];
1086 
1087 		if (phy->phy_state == PHY_VACANT ||
1088 		    phy->phy_state == PHY_NOT_PRESENT)
1089 			continue;
1090 
1091 		if ((phy->attached_dev_type == FANOUT_DEV ||
1092 		     phy->attached_dev_type == EDGE_DEV) &&
1093 		    phy->routing_attr == SUBTRACTIVE_ROUTING) {
1094 
1095 			if (!sub_sas_addr)
1096 				sub_sas_addr = &phy->attached_sas_addr[0];
1097 			else if (SAS_ADDR(sub_sas_addr) !=
1098 				 SAS_ADDR(phy->attached_sas_addr)) {
1099 
1100 				SAS_DPRINTK("ex %016llx phy 0x%x "
1101 					    "diverges(%016llx) on subtractive "
1102 					    "boundary(%016llx). Disabled\n",
1103 					    SAS_ADDR(dev->sas_addr), i,
1104 					    SAS_ADDR(phy->attached_sas_addr),
1105 					    SAS_ADDR(sub_sas_addr));
1106 				sas_ex_disable_phy(dev, i);
1107 			}
1108 		}
1109 	}
1110 	return 0;
1111 }
1112 
1113 static void sas_print_parent_topology_bug(struct domain_device *child,
1114 						 struct ex_phy *parent_phy,
1115 						 struct ex_phy *child_phy)
1116 {
1117 	static const char ra_char[] = {
1118 		[DIRECT_ROUTING] = 'D',
1119 		[SUBTRACTIVE_ROUTING] = 'S',
1120 		[TABLE_ROUTING] = 'T',
1121 	};
1122 	static const char *ex_type[] = {
1123 		[EDGE_DEV] = "edge",
1124 		[FANOUT_DEV] = "fanout",
1125 	};
1126 	struct domain_device *parent = child->parent;
1127 
1128 	sas_printk("%s ex %016llx phy 0x%x <--> %s ex %016llx phy 0x%x "
1129 		   "has %c:%c routing link!\n",
1130 
1131 		   ex_type[parent->dev_type],
1132 		   SAS_ADDR(parent->sas_addr),
1133 		   parent_phy->phy_id,
1134 
1135 		   ex_type[child->dev_type],
1136 		   SAS_ADDR(child->sas_addr),
1137 		   child_phy->phy_id,
1138 
1139 		   ra_char[parent_phy->routing_attr],
1140 		   ra_char[child_phy->routing_attr]);
1141 }
1142 
1143 static int sas_check_eeds(struct domain_device *child,
1144 				 struct ex_phy *parent_phy,
1145 				 struct ex_phy *child_phy)
1146 {
1147 	int res = 0;
1148 	struct domain_device *parent = child->parent;
1149 
1150 	if (SAS_ADDR(parent->port->disc.fanout_sas_addr) != 0) {
1151 		res = -ENODEV;
1152 		SAS_DPRINTK("edge ex %016llx phy S:0x%x <--> edge ex %016llx "
1153 			    "phy S:0x%x, while there is a fanout ex %016llx\n",
1154 			    SAS_ADDR(parent->sas_addr),
1155 			    parent_phy->phy_id,
1156 			    SAS_ADDR(child->sas_addr),
1157 			    child_phy->phy_id,
1158 			    SAS_ADDR(parent->port->disc.fanout_sas_addr));
1159 	} else if (SAS_ADDR(parent->port->disc.eeds_a) == 0) {
1160 		memcpy(parent->port->disc.eeds_a, parent->sas_addr,
1161 		       SAS_ADDR_SIZE);
1162 		memcpy(parent->port->disc.eeds_b, child->sas_addr,
1163 		       SAS_ADDR_SIZE);
1164 	} else if (((SAS_ADDR(parent->port->disc.eeds_a) ==
1165 		    SAS_ADDR(parent->sas_addr)) ||
1166 		   (SAS_ADDR(parent->port->disc.eeds_a) ==
1167 		    SAS_ADDR(child->sas_addr)))
1168 		   &&
1169 		   ((SAS_ADDR(parent->port->disc.eeds_b) ==
1170 		     SAS_ADDR(parent->sas_addr)) ||
1171 		    (SAS_ADDR(parent->port->disc.eeds_b) ==
1172 		     SAS_ADDR(child->sas_addr))))
1173 		;
1174 	else {
1175 		res = -ENODEV;
1176 		SAS_DPRINTK("edge ex %016llx phy 0x%x <--> edge ex %016llx "
1177 			    "phy 0x%x link forms a third EEDS!\n",
1178 			    SAS_ADDR(parent->sas_addr),
1179 			    parent_phy->phy_id,
1180 			    SAS_ADDR(child->sas_addr),
1181 			    child_phy->phy_id);
1182 	}
1183 
1184 	return res;
1185 }
1186 
1187 /* Here we spill over 80 columns.  It is intentional.
1188  */
1189 static int sas_check_parent_topology(struct domain_device *child)
1190 {
1191 	struct expander_device *child_ex = &child->ex_dev;
1192 	struct expander_device *parent_ex;
1193 	int i;
1194 	int res = 0;
1195 
1196 	if (!child->parent)
1197 		return 0;
1198 
1199 	if (child->parent->dev_type != EDGE_DEV &&
1200 	    child->parent->dev_type != FANOUT_DEV)
1201 		return 0;
1202 
1203 	parent_ex = &child->parent->ex_dev;
1204 
1205 	for (i = 0; i < parent_ex->num_phys; i++) {
1206 		struct ex_phy *parent_phy = &parent_ex->ex_phy[i];
1207 		struct ex_phy *child_phy;
1208 
1209 		if (parent_phy->phy_state == PHY_VACANT ||
1210 		    parent_phy->phy_state == PHY_NOT_PRESENT)
1211 			continue;
1212 
1213 		if (SAS_ADDR(parent_phy->attached_sas_addr) != SAS_ADDR(child->sas_addr))
1214 			continue;
1215 
1216 		child_phy = &child_ex->ex_phy[parent_phy->attached_phy_id];
1217 
1218 		switch (child->parent->dev_type) {
1219 		case EDGE_DEV:
1220 			if (child->dev_type == FANOUT_DEV) {
1221 				if (parent_phy->routing_attr != SUBTRACTIVE_ROUTING ||
1222 				    child_phy->routing_attr != TABLE_ROUTING) {
1223 					sas_print_parent_topology_bug(child, parent_phy, child_phy);
1224 					res = -ENODEV;
1225 				}
1226 			} else if (parent_phy->routing_attr == SUBTRACTIVE_ROUTING) {
1227 				if (child_phy->routing_attr == SUBTRACTIVE_ROUTING) {
1228 					res = sas_check_eeds(child, parent_phy, child_phy);
1229 				} else if (child_phy->routing_attr != TABLE_ROUTING) {
1230 					sas_print_parent_topology_bug(child, parent_phy, child_phy);
1231 					res = -ENODEV;
1232 				}
1233 			} else if (parent_phy->routing_attr == TABLE_ROUTING &&
1234 				   child_phy->routing_attr != SUBTRACTIVE_ROUTING) {
1235 				sas_print_parent_topology_bug(child, parent_phy, child_phy);
1236 				res = -ENODEV;
1237 			}
1238 			break;
1239 		case FANOUT_DEV:
1240 			if (parent_phy->routing_attr != TABLE_ROUTING ||
1241 			    child_phy->routing_attr != SUBTRACTIVE_ROUTING) {
1242 				sas_print_parent_topology_bug(child, parent_phy, child_phy);
1243 				res = -ENODEV;
1244 			}
1245 			break;
1246 		default:
1247 			break;
1248 		}
1249 	}
1250 
1251 	return res;
1252 }
1253 
1254 #define RRI_REQ_SIZE  16
1255 #define RRI_RESP_SIZE 44
1256 
1257 static int sas_configure_present(struct domain_device *dev, int phy_id,
1258 				 u8 *sas_addr, int *index, int *present)
1259 {
1260 	int i, res = 0;
1261 	struct expander_device *ex = &dev->ex_dev;
1262 	struct ex_phy *phy = &ex->ex_phy[phy_id];
1263 	u8 *rri_req;
1264 	u8 *rri_resp;
1265 
1266 	*present = 0;
1267 	*index = 0;
1268 
1269 	rri_req = alloc_smp_req(RRI_REQ_SIZE);
1270 	if (!rri_req)
1271 		return -ENOMEM;
1272 
1273 	rri_resp = alloc_smp_resp(RRI_RESP_SIZE);
1274 	if (!rri_resp) {
1275 		kfree(rri_req);
1276 		return -ENOMEM;
1277 	}
1278 
1279 	rri_req[1] = SMP_REPORT_ROUTE_INFO;
1280 	rri_req[9] = phy_id;
1281 
1282 	for (i = 0; i < ex->max_route_indexes ; i++) {
1283 		*(__be16 *)(rri_req+6) = cpu_to_be16(i);
1284 		res = smp_execute_task(dev, rri_req, RRI_REQ_SIZE, rri_resp,
1285 				       RRI_RESP_SIZE);
1286 		if (res)
1287 			goto out;
1288 		res = rri_resp[2];
1289 		if (res == SMP_RESP_NO_INDEX) {
1290 			SAS_DPRINTK("overflow of indexes: dev %016llx "
1291 				    "phy 0x%x index 0x%x\n",
1292 				    SAS_ADDR(dev->sas_addr), phy_id, i);
1293 			goto out;
1294 		} else if (res != SMP_RESP_FUNC_ACC) {
1295 			SAS_DPRINTK("%s: dev %016llx phy 0x%x index 0x%x "
1296 				    "result 0x%x\n", __func__,
1297 				    SAS_ADDR(dev->sas_addr), phy_id, i, res);
1298 			goto out;
1299 		}
1300 		if (SAS_ADDR(sas_addr) != 0) {
1301 			if (SAS_ADDR(rri_resp+16) == SAS_ADDR(sas_addr)) {
1302 				*index = i;
1303 				if ((rri_resp[12] & 0x80) == 0x80)
1304 					*present = 0;
1305 				else
1306 					*present = 1;
1307 				goto out;
1308 			} else if (SAS_ADDR(rri_resp+16) == 0) {
1309 				*index = i;
1310 				*present = 0;
1311 				goto out;
1312 			}
1313 		} else if (SAS_ADDR(rri_resp+16) == 0 &&
1314 			   phy->last_da_index < i) {
1315 			phy->last_da_index = i;
1316 			*index = i;
1317 			*present = 0;
1318 			goto out;
1319 		}
1320 	}
1321 	res = -1;
1322 out:
1323 	kfree(rri_req);
1324 	kfree(rri_resp);
1325 	return res;
1326 }
1327 
1328 #define CRI_REQ_SIZE  44
1329 #define CRI_RESP_SIZE  8
1330 
1331 static int sas_configure_set(struct domain_device *dev, int phy_id,
1332 			     u8 *sas_addr, int index, int include)
1333 {
1334 	int res;
1335 	u8 *cri_req;
1336 	u8 *cri_resp;
1337 
1338 	cri_req = alloc_smp_req(CRI_REQ_SIZE);
1339 	if (!cri_req)
1340 		return -ENOMEM;
1341 
1342 	cri_resp = alloc_smp_resp(CRI_RESP_SIZE);
1343 	if (!cri_resp) {
1344 		kfree(cri_req);
1345 		return -ENOMEM;
1346 	}
1347 
1348 	cri_req[1] = SMP_CONF_ROUTE_INFO;
1349 	*(__be16 *)(cri_req+6) = cpu_to_be16(index);
1350 	cri_req[9] = phy_id;
1351 	if (SAS_ADDR(sas_addr) == 0 || !include)
1352 		cri_req[12] |= 0x80;
1353 	memcpy(cri_req+16, sas_addr, SAS_ADDR_SIZE);
1354 
1355 	res = smp_execute_task(dev, cri_req, CRI_REQ_SIZE, cri_resp,
1356 			       CRI_RESP_SIZE);
1357 	if (res)
1358 		goto out;
1359 	res = cri_resp[2];
1360 	if (res == SMP_RESP_NO_INDEX) {
1361 		SAS_DPRINTK("overflow of indexes: dev %016llx phy 0x%x "
1362 			    "index 0x%x\n",
1363 			    SAS_ADDR(dev->sas_addr), phy_id, index);
1364 	}
1365 out:
1366 	kfree(cri_req);
1367 	kfree(cri_resp);
1368 	return res;
1369 }
1370 
1371 static int sas_configure_phy(struct domain_device *dev, int phy_id,
1372 				    u8 *sas_addr, int include)
1373 {
1374 	int index;
1375 	int present;
1376 	int res;
1377 
1378 	res = sas_configure_present(dev, phy_id, sas_addr, &index, &present);
1379 	if (res)
1380 		return res;
1381 	if (include ^ present)
1382 		return sas_configure_set(dev, phy_id, sas_addr, index,include);
1383 
1384 	return res;
1385 }
1386 
1387 /**
1388  * sas_configure_parent -- configure routing table of parent
1389  * parent: parent expander
1390  * child: child expander
1391  * sas_addr: SAS port identifier of device directly attached to child
1392  */
1393 static int sas_configure_parent(struct domain_device *parent,
1394 				struct domain_device *child,
1395 				u8 *sas_addr, int include)
1396 {
1397 	struct expander_device *ex_parent = &parent->ex_dev;
1398 	int res = 0;
1399 	int i;
1400 
1401 	if (parent->parent) {
1402 		res = sas_configure_parent(parent->parent, parent, sas_addr,
1403 					   include);
1404 		if (res)
1405 			return res;
1406 	}
1407 
1408 	if (ex_parent->conf_route_table == 0) {
1409 		SAS_DPRINTK("ex %016llx has self-configuring routing table\n",
1410 			    SAS_ADDR(parent->sas_addr));
1411 		return 0;
1412 	}
1413 
1414 	for (i = 0; i < ex_parent->num_phys; i++) {
1415 		struct ex_phy *phy = &ex_parent->ex_phy[i];
1416 
1417 		if ((phy->routing_attr == TABLE_ROUTING) &&
1418 		    (SAS_ADDR(phy->attached_sas_addr) ==
1419 		     SAS_ADDR(child->sas_addr))) {
1420 			res = sas_configure_phy(parent, i, sas_addr, include);
1421 			if (res)
1422 				return res;
1423 		}
1424 	}
1425 
1426 	return res;
1427 }
1428 
1429 /**
1430  * sas_configure_routing -- configure routing
1431  * dev: expander device
1432  * sas_addr: port identifier of device directly attached to the expander device
1433  */
1434 static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr)
1435 {
1436 	if (dev->parent)
1437 		return sas_configure_parent(dev->parent, dev, sas_addr, 1);
1438 	return 0;
1439 }
1440 
1441 static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr)
1442 {
1443 	if (dev->parent)
1444 		return sas_configure_parent(dev->parent, dev, sas_addr, 0);
1445 	return 0;
1446 }
1447 
1448 /**
1449  * sas_discover_expander -- expander discovery
1450  * @ex: pointer to expander domain device
1451  *
1452  * See comment in sas_discover_sata().
1453  */
1454 static int sas_discover_expander(struct domain_device *dev)
1455 {
1456 	int res;
1457 
1458 	res = sas_notify_lldd_dev_found(dev);
1459 	if (res)
1460 		return res;
1461 
1462 	res = sas_ex_general(dev);
1463 	if (res)
1464 		goto out_err;
1465 	res = sas_ex_manuf_info(dev);
1466 	if (res)
1467 		goto out_err;
1468 
1469 	res = sas_expander_discover(dev);
1470 	if (res) {
1471 		SAS_DPRINTK("expander %016llx discovery failed(0x%x)\n",
1472 			    SAS_ADDR(dev->sas_addr), res);
1473 		goto out_err;
1474 	}
1475 
1476 	sas_check_ex_subtractive_boundary(dev);
1477 	res = sas_check_parent_topology(dev);
1478 	if (res)
1479 		goto out_err;
1480 	return 0;
1481 out_err:
1482 	sas_notify_lldd_dev_gone(dev);
1483 	return res;
1484 }
1485 
1486 static int sas_ex_level_discovery(struct asd_sas_port *port, const int level)
1487 {
1488 	int res = 0;
1489 	struct domain_device *dev;
1490 
1491 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
1492 		if (dev->dev_type == EDGE_DEV ||
1493 		    dev->dev_type == FANOUT_DEV) {
1494 			struct sas_expander_device *ex =
1495 				rphy_to_expander_device(dev->rphy);
1496 
1497 			if (level == ex->level)
1498 				res = sas_ex_discover_devices(dev, -1);
1499 			else if (level > 0)
1500 				res = sas_ex_discover_devices(port->port_dev, -1);
1501 
1502 		}
1503 	}
1504 
1505 	return res;
1506 }
1507 
1508 static int sas_ex_bfs_disc(struct asd_sas_port *port)
1509 {
1510 	int res;
1511 	int level;
1512 
1513 	do {
1514 		level = port->disc.max_level;
1515 		res = sas_ex_level_discovery(port, level);
1516 		mb();
1517 	} while (level < port->disc.max_level);
1518 
1519 	return res;
1520 }
1521 
1522 int sas_discover_root_expander(struct domain_device *dev)
1523 {
1524 	int res;
1525 	struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);
1526 
1527 	res = sas_rphy_add(dev->rphy);
1528 	if (res)
1529 		goto out_err;
1530 
1531 	ex->level = dev->port->disc.max_level; /* 0 */
1532 	res = sas_discover_expander(dev);
1533 	if (res)
1534 		goto out_err2;
1535 
1536 	sas_ex_bfs_disc(dev->port);
1537 
1538 	return res;
1539 
1540 out_err2:
1541 	sas_rphy_remove(dev->rphy);
1542 out_err:
1543 	return res;
1544 }
1545 
1546 /* ---------- Domain revalidation ---------- */
1547 
1548 static int sas_get_phy_discover(struct domain_device *dev,
1549 				int phy_id, struct smp_resp *disc_resp)
1550 {
1551 	int res;
1552 	u8 *disc_req;
1553 
1554 	disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
1555 	if (!disc_req)
1556 		return -ENOMEM;
1557 
1558 	disc_req[1] = SMP_DISCOVER;
1559 	disc_req[9] = phy_id;
1560 
1561 	res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
1562 			       disc_resp, DISCOVER_RESP_SIZE);
1563 	if (res)
1564 		goto out;
1565 	else if (disc_resp->result != SMP_RESP_FUNC_ACC) {
1566 		res = disc_resp->result;
1567 		goto out;
1568 	}
1569 out:
1570 	kfree(disc_req);
1571 	return res;
1572 }
1573 
1574 static int sas_get_phy_change_count(struct domain_device *dev,
1575 				    int phy_id, int *pcc)
1576 {
1577 	int res;
1578 	struct smp_resp *disc_resp;
1579 
1580 	disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
1581 	if (!disc_resp)
1582 		return -ENOMEM;
1583 
1584 	res = sas_get_phy_discover(dev, phy_id, disc_resp);
1585 	if (!res)
1586 		*pcc = disc_resp->disc.change_count;
1587 
1588 	kfree(disc_resp);
1589 	return res;
1590 }
1591 
1592 static int sas_get_phy_attached_sas_addr(struct domain_device *dev,
1593 					 int phy_id, u8 *attached_sas_addr)
1594 {
1595 	int res;
1596 	struct smp_resp *disc_resp;
1597 	struct discover_resp *dr;
1598 
1599 	disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
1600 	if (!disc_resp)
1601 		return -ENOMEM;
1602 	dr = &disc_resp->disc;
1603 
1604 	res = sas_get_phy_discover(dev, phy_id, disc_resp);
1605 	if (!res) {
1606 		memcpy(attached_sas_addr,disc_resp->disc.attached_sas_addr,8);
1607 		if (dr->attached_dev_type == 0)
1608 			memset(attached_sas_addr, 0, 8);
1609 	}
1610 	kfree(disc_resp);
1611 	return res;
1612 }
1613 
1614 static int sas_find_bcast_phy(struct domain_device *dev, int *phy_id,
1615 			      int from_phy, bool update)
1616 {
1617 	struct expander_device *ex = &dev->ex_dev;
1618 	int res = 0;
1619 	int i;
1620 
1621 	for (i = from_phy; i < ex->num_phys; i++) {
1622 		int phy_change_count = 0;
1623 
1624 		res = sas_get_phy_change_count(dev, i, &phy_change_count);
1625 		if (res)
1626 			goto out;
1627 		else if (phy_change_count != ex->ex_phy[i].phy_change_count) {
1628 			if (update)
1629 				ex->ex_phy[i].phy_change_count =
1630 					phy_change_count;
1631 			*phy_id = i;
1632 			return 0;
1633 		}
1634 	}
1635 out:
1636 	return res;
1637 }
1638 
1639 static int sas_get_ex_change_count(struct domain_device *dev, int *ecc)
1640 {
1641 	int res;
1642 	u8  *rg_req;
1643 	struct smp_resp  *rg_resp;
1644 
1645 	rg_req = alloc_smp_req(RG_REQ_SIZE);
1646 	if (!rg_req)
1647 		return -ENOMEM;
1648 
1649 	rg_resp = alloc_smp_resp(RG_RESP_SIZE);
1650 	if (!rg_resp) {
1651 		kfree(rg_req);
1652 		return -ENOMEM;
1653 	}
1654 
1655 	rg_req[1] = SMP_REPORT_GENERAL;
1656 
1657 	res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
1658 			       RG_RESP_SIZE);
1659 	if (res)
1660 		goto out;
1661 	if (rg_resp->result != SMP_RESP_FUNC_ACC) {
1662 		res = rg_resp->result;
1663 		goto out;
1664 	}
1665 
1666 	*ecc = be16_to_cpu(rg_resp->rg.change_count);
1667 out:
1668 	kfree(rg_resp);
1669 	kfree(rg_req);
1670 	return res;
1671 }
1672 /**
1673  * sas_find_bcast_dev -  find the device issue BROADCAST(CHANGE).
1674  * @dev:domain device to be detect.
1675  * @src_dev: the device which originated BROADCAST(CHANGE).
1676  *
1677  * Add self-configuration expander suport. Suppose two expander cascading,
1678  * when the first level expander is self-configuring, hotplug the disks in
1679  * second level expander, BROADCAST(CHANGE) will not only be originated
1680  * in the second level expander, but also be originated in the first level
1681  * expander (see SAS protocol SAS 2r-14, 7.11 for detail), it is to say,
1682  * expander changed count in two level expanders will all increment at least
1683  * once, but the phy which chang count has changed is the source device which
1684  * we concerned.
1685  */
1686 
1687 static int sas_find_bcast_dev(struct domain_device *dev,
1688 			      struct domain_device **src_dev)
1689 {
1690 	struct expander_device *ex = &dev->ex_dev;
1691 	int ex_change_count = -1;
1692 	int phy_id = -1;
1693 	int res;
1694 	struct domain_device *ch;
1695 
1696 	res = sas_get_ex_change_count(dev, &ex_change_count);
1697 	if (res)
1698 		goto out;
1699 	if (ex_change_count != -1 && ex_change_count != ex->ex_change_count) {
1700 		/* Just detect if this expander phys phy change count changed,
1701 		* in order to determine if this expander originate BROADCAST,
1702 		* and do not update phy change count field in our structure.
1703 		*/
1704 		res = sas_find_bcast_phy(dev, &phy_id, 0, false);
1705 		if (phy_id != -1) {
1706 			*src_dev = dev;
1707 			ex->ex_change_count = ex_change_count;
1708 			SAS_DPRINTK("Expander phy change count has changed\n");
1709 			return res;
1710 		} else
1711 			SAS_DPRINTK("Expander phys DID NOT change\n");
1712 	}
1713 	list_for_each_entry(ch, &ex->children, siblings) {
1714 		if (ch->dev_type == EDGE_DEV || ch->dev_type == FANOUT_DEV) {
1715 			res = sas_find_bcast_dev(ch, src_dev);
1716 			if (src_dev)
1717 				return res;
1718 		}
1719 	}
1720 out:
1721 	return res;
1722 }
1723 
1724 static void sas_unregister_ex_tree(struct domain_device *dev)
1725 {
1726 	struct expander_device *ex = &dev->ex_dev;
1727 	struct domain_device *child, *n;
1728 
1729 	list_for_each_entry_safe(child, n, &ex->children, siblings) {
1730 		child->gone = 1;
1731 		if (child->dev_type == EDGE_DEV ||
1732 		    child->dev_type == FANOUT_DEV)
1733 			sas_unregister_ex_tree(child);
1734 		else
1735 			sas_unregister_dev(child);
1736 	}
1737 	sas_unregister_dev(dev);
1738 }
1739 
1740 static void sas_unregister_devs_sas_addr(struct domain_device *parent,
1741 					 int phy_id, bool last)
1742 {
1743 	struct expander_device *ex_dev = &parent->ex_dev;
1744 	struct ex_phy *phy = &ex_dev->ex_phy[phy_id];
1745 	struct domain_device *child, *n;
1746 	if (last) {
1747 		list_for_each_entry_safe(child, n,
1748 			&ex_dev->children, siblings) {
1749 			if (SAS_ADDR(child->sas_addr) ==
1750 			    SAS_ADDR(phy->attached_sas_addr)) {
1751 				child->gone = 1;
1752 				if (child->dev_type == EDGE_DEV ||
1753 				    child->dev_type == FANOUT_DEV)
1754 					sas_unregister_ex_tree(child);
1755 				else
1756 					sas_unregister_dev(child);
1757 				break;
1758 			}
1759 		}
1760 		parent->gone = 1;
1761 		sas_disable_routing(parent, phy->attached_sas_addr);
1762 	}
1763 	memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
1764 	sas_port_delete_phy(phy->port, phy->phy);
1765 	if (phy->port->num_phys == 0)
1766 		sas_port_delete(phy->port);
1767 	phy->port = NULL;
1768 }
1769 
1770 static int sas_discover_bfs_by_root_level(struct domain_device *root,
1771 					  const int level)
1772 {
1773 	struct expander_device *ex_root = &root->ex_dev;
1774 	struct domain_device *child;
1775 	int res = 0;
1776 
1777 	list_for_each_entry(child, &ex_root->children, siblings) {
1778 		if (child->dev_type == EDGE_DEV ||
1779 		    child->dev_type == FANOUT_DEV) {
1780 			struct sas_expander_device *ex =
1781 				rphy_to_expander_device(child->rphy);
1782 
1783 			if (level > ex->level)
1784 				res = sas_discover_bfs_by_root_level(child,
1785 								     level);
1786 			else if (level == ex->level)
1787 				res = sas_ex_discover_devices(child, -1);
1788 		}
1789 	}
1790 	return res;
1791 }
1792 
1793 static int sas_discover_bfs_by_root(struct domain_device *dev)
1794 {
1795 	int res;
1796 	struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);
1797 	int level = ex->level+1;
1798 
1799 	res = sas_ex_discover_devices(dev, -1);
1800 	if (res)
1801 		goto out;
1802 	do {
1803 		res = sas_discover_bfs_by_root_level(dev, level);
1804 		mb();
1805 		level += 1;
1806 	} while (level <= dev->port->disc.max_level);
1807 out:
1808 	return res;
1809 }
1810 
1811 static int sas_discover_new(struct domain_device *dev, int phy_id)
1812 {
1813 	struct ex_phy *ex_phy = &dev->ex_dev.ex_phy[phy_id];
1814 	struct domain_device *child;
1815 	bool found = false;
1816 	int res, i;
1817 
1818 	SAS_DPRINTK("ex %016llx phy%d new device attached\n",
1819 		    SAS_ADDR(dev->sas_addr), phy_id);
1820 	res = sas_ex_phy_discover(dev, phy_id);
1821 	if (res)
1822 		goto out;
1823 	/* to support the wide port inserted */
1824 	for (i = 0; i < dev->ex_dev.num_phys; i++) {
1825 		struct ex_phy *ex_phy_temp = &dev->ex_dev.ex_phy[i];
1826 		if (i == phy_id)
1827 			continue;
1828 		if (SAS_ADDR(ex_phy_temp->attached_sas_addr) ==
1829 		    SAS_ADDR(ex_phy->attached_sas_addr)) {
1830 			found = true;
1831 			break;
1832 		}
1833 	}
1834 	if (found) {
1835 		sas_ex_join_wide_port(dev, phy_id);
1836 		return 0;
1837 	}
1838 	res = sas_ex_discover_devices(dev, phy_id);
1839 	if (!res)
1840 		goto out;
1841 	list_for_each_entry(child, &dev->ex_dev.children, siblings) {
1842 		if (SAS_ADDR(child->sas_addr) ==
1843 		    SAS_ADDR(ex_phy->attached_sas_addr)) {
1844 			if (child->dev_type == EDGE_DEV ||
1845 			    child->dev_type == FANOUT_DEV)
1846 				res = sas_discover_bfs_by_root(child);
1847 			break;
1848 		}
1849 	}
1850 out:
1851 	return res;
1852 }
1853 
1854 static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
1855 {
1856 	struct expander_device *ex = &dev->ex_dev;
1857 	struct ex_phy *phy = &ex->ex_phy[phy_id];
1858 	u8 attached_sas_addr[8];
1859 	int res;
1860 
1861 	res = sas_get_phy_attached_sas_addr(dev, phy_id, attached_sas_addr);
1862 	switch (res) {
1863 	case SMP_RESP_NO_PHY:
1864 		phy->phy_state = PHY_NOT_PRESENT;
1865 		sas_unregister_devs_sas_addr(dev, phy_id, last);
1866 		goto out; break;
1867 	case SMP_RESP_PHY_VACANT:
1868 		phy->phy_state = PHY_VACANT;
1869 		sas_unregister_devs_sas_addr(dev, phy_id, last);
1870 		goto out; break;
1871 	case SMP_RESP_FUNC_ACC:
1872 		break;
1873 	}
1874 
1875 	if (SAS_ADDR(attached_sas_addr) == 0) {
1876 		phy->phy_state = PHY_EMPTY;
1877 		sas_unregister_devs_sas_addr(dev, phy_id, last);
1878 	} else if (SAS_ADDR(attached_sas_addr) ==
1879 		   SAS_ADDR(phy->attached_sas_addr)) {
1880 		SAS_DPRINTK("ex %016llx phy 0x%x broadcast flutter\n",
1881 			    SAS_ADDR(dev->sas_addr), phy_id);
1882 		sas_ex_phy_discover(dev, phy_id);
1883 	} else
1884 		res = sas_discover_new(dev, phy_id);
1885 out:
1886 	return res;
1887 }
1888 
1889 /**
1890  * sas_rediscover - revalidate the domain.
1891  * @dev:domain device to be detect.
1892  * @phy_id: the phy id will be detected.
1893  *
1894  * NOTE: this process _must_ quit (return) as soon as any connection
1895  * errors are encountered.  Connection recovery is done elsewhere.
1896  * Discover process only interrogates devices in order to discover the
1897  * domain.For plugging out, we un-register the device only when it is
1898  * the last phy in the port, for other phys in this port, we just delete it
1899  * from the port.For inserting, we do discovery when it is the
1900  * first phy,for other phys in this port, we add it to the port to
1901  * forming the wide-port.
1902  */
1903 static int sas_rediscover(struct domain_device *dev, const int phy_id)
1904 {
1905 	struct expander_device *ex = &dev->ex_dev;
1906 	struct ex_phy *changed_phy = &ex->ex_phy[phy_id];
1907 	int res = 0;
1908 	int i;
1909 	bool last = true;	/* is this the last phy of the port */
1910 
1911 	SAS_DPRINTK("ex %016llx phy%d originated BROADCAST(CHANGE)\n",
1912 		    SAS_ADDR(dev->sas_addr), phy_id);
1913 
1914 	if (SAS_ADDR(changed_phy->attached_sas_addr) != 0) {
1915 		for (i = 0; i < ex->num_phys; i++) {
1916 			struct ex_phy *phy = &ex->ex_phy[i];
1917 
1918 			if (i == phy_id)
1919 				continue;
1920 			if (SAS_ADDR(phy->attached_sas_addr) ==
1921 			    SAS_ADDR(changed_phy->attached_sas_addr)) {
1922 				SAS_DPRINTK("phy%d part of wide port with "
1923 					    "phy%d\n", phy_id, i);
1924 				last = false;
1925 				break;
1926 			}
1927 		}
1928 		res = sas_rediscover_dev(dev, phy_id, last);
1929 	} else
1930 		res = sas_discover_new(dev, phy_id);
1931 	return res;
1932 }
1933 
1934 /**
1935  * sas_revalidate_domain -- revalidate the domain
1936  * @port: port to the domain of interest
1937  *
1938  * NOTE: this process _must_ quit (return) as soon as any connection
1939  * errors are encountered.  Connection recovery is done elsewhere.
1940  * Discover process only interrogates devices in order to discover the
1941  * domain.
1942  */
1943 int sas_ex_revalidate_domain(struct domain_device *port_dev)
1944 {
1945 	int res;
1946 	struct domain_device *dev = NULL;
1947 
1948 	res = sas_find_bcast_dev(port_dev, &dev);
1949 	if (res)
1950 		goto out;
1951 	if (dev) {
1952 		struct expander_device *ex = &dev->ex_dev;
1953 		int i = 0, phy_id;
1954 
1955 		do {
1956 			phy_id = -1;
1957 			res = sas_find_bcast_phy(dev, &phy_id, i, true);
1958 			if (phy_id == -1)
1959 				break;
1960 			res = sas_rediscover(dev, phy_id);
1961 			i = phy_id + 1;
1962 		} while (i < ex->num_phys);
1963 	}
1964 out:
1965 	return res;
1966 }
1967 
1968 int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
1969 		    struct request *req)
1970 {
1971 	struct domain_device *dev;
1972 	int ret, type;
1973 	struct request *rsp = req->next_rq;
1974 
1975 	if (!rsp) {
1976 		printk("%s: space for a smp response is missing\n",
1977 		       __func__);
1978 		return -EINVAL;
1979 	}
1980 
1981 	/* no rphy means no smp target support (ie aic94xx host) */
1982 	if (!rphy)
1983 		return sas_smp_host_handler(shost, req, rsp);
1984 
1985 	type = rphy->identify.device_type;
1986 
1987 	if (type != SAS_EDGE_EXPANDER_DEVICE &&
1988 	    type != SAS_FANOUT_EXPANDER_DEVICE) {
1989 		printk("%s: can we send a smp request to a device?\n",
1990 		       __func__);
1991 		return -EINVAL;
1992 	}
1993 
1994 	dev = sas_find_dev_by_rphy(rphy);
1995 	if (!dev) {
1996 		printk("%s: fail to find a domain_device?\n", __func__);
1997 		return -EINVAL;
1998 	}
1999 
2000 	/* do we need to support multiple segments? */
2001 	if (req->bio->bi_vcnt > 1 || rsp->bio->bi_vcnt > 1) {
2002 		printk("%s: multiple segments req %u %u, rsp %u %u\n",
2003 		       __func__, req->bio->bi_vcnt, blk_rq_bytes(req),
2004 		       rsp->bio->bi_vcnt, blk_rq_bytes(rsp));
2005 		return -EINVAL;
2006 	}
2007 
2008 	ret = smp_execute_task(dev, bio_data(req->bio), blk_rq_bytes(req),
2009 			       bio_data(rsp->bio), blk_rq_bytes(rsp));
2010 	if (ret > 0) {
2011 		/* positive number is the untransferred residual */
2012 		rsp->resid_len = ret;
2013 		req->resid_len = 0;
2014 		ret = 0;
2015 	} else if (ret == 0) {
2016 		rsp->resid_len = 0;
2017 		req->resid_len = 0;
2018 	}
2019 
2020 	return ret;
2021 }
2022