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 
28 #include "sas_internal.h"
29 
30 #include <scsi/scsi_transport.h>
31 #include <scsi/scsi_transport_sas.h>
32 #include "../scsi_sas_internal.h"
33 
34 static int sas_discover_expander(struct domain_device *dev);
35 static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr);
36 static int sas_configure_phy(struct domain_device *dev, int phy_id,
37 			     u8 *sas_addr, int include);
38 static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr);
39 
40 /* ---------- SMP task management ---------- */
41 
42 static void smp_task_timedout(unsigned long _task)
43 {
44 	struct sas_task *task = (void *) _task;
45 	unsigned long flags;
46 
47 	spin_lock_irqsave(&task->task_state_lock, flags);
48 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
49 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
50 	spin_unlock_irqrestore(&task->task_state_lock, flags);
51 
52 	complete(&task->completion);
53 }
54 
55 static void smp_task_done(struct sas_task *task)
56 {
57 	if (!del_timer(&task->timer))
58 		return;
59 	complete(&task->completion);
60 }
61 
62 /* Give it some long enough timeout. In seconds. */
63 #define SMP_TIMEOUT 10
64 
65 static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
66 			    void *resp, int resp_size)
67 {
68 	int res, retry;
69 	struct sas_task *task = NULL;
70 	struct sas_internal *i =
71 		to_sas_internal(dev->port->ha->core.shost->transportt);
72 
73 	for (retry = 0; retry < 3; retry++) {
74 		task = sas_alloc_task(GFP_KERNEL);
75 		if (!task)
76 			return -ENOMEM;
77 
78 		task->dev = dev;
79 		task->task_proto = dev->tproto;
80 		sg_init_one(&task->smp_task.smp_req, req, req_size);
81 		sg_init_one(&task->smp_task.smp_resp, resp, resp_size);
82 
83 		task->task_done = smp_task_done;
84 
85 		task->timer.data = (unsigned long) task;
86 		task->timer.function = smp_task_timedout;
87 		task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
88 		add_timer(&task->timer);
89 
90 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
91 
92 		if (res) {
93 			del_timer(&task->timer);
94 			SAS_DPRINTK("executing SMP task failed:%d\n", res);
95 			goto ex_err;
96 		}
97 
98 		wait_for_completion(&task->completion);
99 		res = -ECOMM;
100 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
101 			SAS_DPRINTK("smp task timed out or aborted\n");
102 			i->dft->lldd_abort_task(task);
103 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
104 				SAS_DPRINTK("SMP task aborted and not done\n");
105 				goto ex_err;
106 			}
107 		}
108 		if (task->task_status.resp == SAS_TASK_COMPLETE &&
109 		    task->task_status.stat == SAM_GOOD) {
110 			res = 0;
111 			break;
112 		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
113 		      task->task_status.stat == SAS_DATA_UNDERRUN) {
114 			/* no error, but return the number of bytes of
115 			 * underrun */
116 			res = task->task_status.residual;
117 			break;
118 		} if (task->task_status.resp == SAS_TASK_COMPLETE &&
119 		      task->task_status.stat == SAS_DATA_OVERRUN) {
120 			res = -EMSGSIZE;
121 			break;
122 		} else {
123 			SAS_DPRINTK("%s: task to dev %016llx response: 0x%x "
124 				    "status 0x%x\n", __func__,
125 				    SAS_ADDR(dev->sas_addr),
126 				    task->task_status.resp,
127 				    task->task_status.stat);
128 			sas_free_task(task);
129 			task = NULL;
130 		}
131 	}
132 ex_err:
133 	BUG_ON(retry == 3 && task != NULL);
134 	if (task != NULL) {
135 		sas_free_task(task);
136 	}
137 	return res;
138 }
139 
140 /* ---------- Allocations ---------- */
141 
142 static inline void *alloc_smp_req(int size)
143 {
144 	u8 *p = kzalloc(size, GFP_KERNEL);
145 	if (p)
146 		p[0] = SMP_REQUEST;
147 	return p;
148 }
149 
150 static inline void *alloc_smp_resp(int size)
151 {
152 	return kzalloc(size, GFP_KERNEL);
153 }
154 
155 /* ---------- Expander configuration ---------- */
156 
157 static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
158 			   void *disc_resp)
159 {
160 	struct expander_device *ex = &dev->ex_dev;
161 	struct ex_phy *phy = &ex->ex_phy[phy_id];
162 	struct smp_resp *resp = disc_resp;
163 	struct discover_resp *dr = &resp->disc;
164 	struct sas_rphy *rphy = dev->rphy;
165 	int rediscover = (phy->phy != NULL);
166 
167 	if (!rediscover) {
168 		phy->phy = sas_phy_alloc(&rphy->dev, phy_id);
169 
170 		/* FIXME: error_handling */
171 		BUG_ON(!phy->phy);
172 	}
173 
174 	switch (resp->result) {
175 	case SMP_RESP_PHY_VACANT:
176 		phy->phy_state = PHY_VACANT;
177 		return;
178 	default:
179 		phy->phy_state = PHY_NOT_PRESENT;
180 		return;
181 	case SMP_RESP_FUNC_ACC:
182 		phy->phy_state = PHY_EMPTY; /* do not know yet */
183 		break;
184 	}
185 
186 	phy->phy_id = phy_id;
187 	phy->attached_dev_type = dr->attached_dev_type;
188 	phy->linkrate = dr->linkrate;
189 	phy->attached_sata_host = dr->attached_sata_host;
190 	phy->attached_sata_dev  = dr->attached_sata_dev;
191 	phy->attached_sata_ps   = dr->attached_sata_ps;
192 	phy->attached_iproto = dr->iproto << 1;
193 	phy->attached_tproto = dr->tproto << 1;
194 	memcpy(phy->attached_sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE);
195 	phy->attached_phy_id = dr->attached_phy_id;
196 	phy->phy_change_count = dr->change_count;
197 	phy->routing_attr = dr->routing_attr;
198 	phy->virtual = dr->virtual;
199 	phy->last_da_index = -1;
200 
201 	phy->phy->identify.initiator_port_protocols = phy->attached_iproto;
202 	phy->phy->identify.target_port_protocols = phy->attached_tproto;
203 	phy->phy->identify.phy_identifier = phy_id;
204 	phy->phy->minimum_linkrate_hw = dr->hmin_linkrate;
205 	phy->phy->maximum_linkrate_hw = dr->hmax_linkrate;
206 	phy->phy->minimum_linkrate = dr->pmin_linkrate;
207 	phy->phy->maximum_linkrate = dr->pmax_linkrate;
208 	phy->phy->negotiated_linkrate = phy->linkrate;
209 
210 	if (!rediscover)
211 		sas_phy_add(phy->phy);
212 
213 	SAS_DPRINTK("ex %016llx phy%02d:%c attached: %016llx\n",
214 		    SAS_ADDR(dev->sas_addr), phy->phy_id,
215 		    phy->routing_attr == TABLE_ROUTING ? 'T' :
216 		    phy->routing_attr == DIRECT_ROUTING ? 'D' :
217 		    phy->routing_attr == SUBTRACTIVE_ROUTING ? 'S' : '?',
218 		    SAS_ADDR(phy->attached_sas_addr));
219 
220 	return;
221 }
222 
223 #define DISCOVER_REQ_SIZE  16
224 #define DISCOVER_RESP_SIZE 56
225 
226 static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
227 				      u8 *disc_resp, int single)
228 {
229 	int i, res;
230 
231 	disc_req[9] = single;
232 	for (i = 1 ; i < 3; i++) {
233 		struct discover_resp *dr;
234 
235 		res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
236 				       disc_resp, DISCOVER_RESP_SIZE);
237 		if (res)
238 			return res;
239 		/* This is detecting a failure to transmit inital
240 		 * dev to host FIS as described in section G.5 of
241 		 * sas-2 r 04b */
242 		dr = &((struct smp_resp *)disc_resp)->disc;
243 		if (!(dr->attached_dev_type == 0 &&
244 		      dr->attached_sata_dev))
245 			break;
246 		/* In order to generate the dev to host FIS, we
247 		 * send a link reset to the expander port */
248 		sas_smp_phy_control(dev, single, PHY_FUNC_LINK_RESET, NULL);
249 		/* Wait for the reset to trigger the negotiation */
250 		msleep(500);
251 	}
252 	sas_set_ex_phy(dev, single, disc_resp);
253 	return 0;
254 }
255 
256 static int sas_ex_phy_discover(struct domain_device *dev, int single)
257 {
258 	struct expander_device *ex = &dev->ex_dev;
259 	int  res = 0;
260 	u8   *disc_req;
261 	u8   *disc_resp;
262 
263 	disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
264 	if (!disc_req)
265 		return -ENOMEM;
266 
267 	disc_resp = alloc_smp_req(DISCOVER_RESP_SIZE);
268 	if (!disc_resp) {
269 		kfree(disc_req);
270 		return -ENOMEM;
271 	}
272 
273 	disc_req[1] = SMP_DISCOVER;
274 
275 	if (0 <= single && single < ex->num_phys) {
276 		res = sas_ex_phy_discover_helper(dev, disc_req, disc_resp, single);
277 	} else {
278 		int i;
279 
280 		for (i = 0; i < ex->num_phys; i++) {
281 			res = sas_ex_phy_discover_helper(dev, disc_req,
282 							 disc_resp, i);
283 			if (res)
284 				goto out_err;
285 		}
286 	}
287 out_err:
288 	kfree(disc_resp);
289 	kfree(disc_req);
290 	return res;
291 }
292 
293 static int sas_expander_discover(struct domain_device *dev)
294 {
295 	struct expander_device *ex = &dev->ex_dev;
296 	int res = -ENOMEM;
297 
298 	ex->ex_phy = kzalloc(sizeof(*ex->ex_phy)*ex->num_phys, GFP_KERNEL);
299 	if (!ex->ex_phy)
300 		return -ENOMEM;
301 
302 	res = sas_ex_phy_discover(dev, -1);
303 	if (res)
304 		goto out_err;
305 
306 	return 0;
307  out_err:
308 	kfree(ex->ex_phy);
309 	ex->ex_phy = NULL;
310 	return res;
311 }
312 
313 #define MAX_EXPANDER_PHYS 128
314 
315 static void ex_assign_report_general(struct domain_device *dev,
316 					    struct smp_resp *resp)
317 {
318 	struct report_general_resp *rg = &resp->rg;
319 
320 	dev->ex_dev.ex_change_count = be16_to_cpu(rg->change_count);
321 	dev->ex_dev.max_route_indexes = be16_to_cpu(rg->route_indexes);
322 	dev->ex_dev.num_phys = min(rg->num_phys, (u8)MAX_EXPANDER_PHYS);
323 	dev->ex_dev.conf_route_table = rg->conf_route_table;
324 	dev->ex_dev.configuring = rg->configuring;
325 	memcpy(dev->ex_dev.enclosure_logical_id, rg->enclosure_logical_id, 8);
326 }
327 
328 #define RG_REQ_SIZE   8
329 #define RG_RESP_SIZE 32
330 
331 static int sas_ex_general(struct domain_device *dev)
332 {
333 	u8 *rg_req;
334 	struct smp_resp *rg_resp;
335 	int res;
336 	int i;
337 
338 	rg_req = alloc_smp_req(RG_REQ_SIZE);
339 	if (!rg_req)
340 		return -ENOMEM;
341 
342 	rg_resp = alloc_smp_resp(RG_RESP_SIZE);
343 	if (!rg_resp) {
344 		kfree(rg_req);
345 		return -ENOMEM;
346 	}
347 
348 	rg_req[1] = SMP_REPORT_GENERAL;
349 
350 	for (i = 0; i < 5; i++) {
351 		res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
352 				       RG_RESP_SIZE);
353 
354 		if (res) {
355 			SAS_DPRINTK("RG to ex %016llx failed:0x%x\n",
356 				    SAS_ADDR(dev->sas_addr), res);
357 			goto out;
358 		} else if (rg_resp->result != SMP_RESP_FUNC_ACC) {
359 			SAS_DPRINTK("RG:ex %016llx returned SMP result:0x%x\n",
360 				    SAS_ADDR(dev->sas_addr), rg_resp->result);
361 			res = rg_resp->result;
362 			goto out;
363 		}
364 
365 		ex_assign_report_general(dev, rg_resp);
366 
367 		if (dev->ex_dev.configuring) {
368 			SAS_DPRINTK("RG: ex %llx self-configuring...\n",
369 				    SAS_ADDR(dev->sas_addr));
370 			schedule_timeout_interruptible(5*HZ);
371 		} else
372 			break;
373 	}
374 out:
375 	kfree(rg_req);
376 	kfree(rg_resp);
377 	return res;
378 }
379 
380 static void ex_assign_manuf_info(struct domain_device *dev, void
381 					*_mi_resp)
382 {
383 	u8 *mi_resp = _mi_resp;
384 	struct sas_rphy *rphy = dev->rphy;
385 	struct sas_expander_device *edev = rphy_to_expander_device(rphy);
386 
387 	memcpy(edev->vendor_id, mi_resp + 12, SAS_EXPANDER_VENDOR_ID_LEN);
388 	memcpy(edev->product_id, mi_resp + 20, SAS_EXPANDER_PRODUCT_ID_LEN);
389 	memcpy(edev->product_rev, mi_resp + 36,
390 	       SAS_EXPANDER_PRODUCT_REV_LEN);
391 
392 	if (mi_resp[8] & 1) {
393 		memcpy(edev->component_vendor_id, mi_resp + 40,
394 		       SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN);
395 		edev->component_id = mi_resp[48] << 8 | mi_resp[49];
396 		edev->component_revision_id = mi_resp[50];
397 	}
398 }
399 
400 #define MI_REQ_SIZE   8
401 #define MI_RESP_SIZE 64
402 
403 static int sas_ex_manuf_info(struct domain_device *dev)
404 {
405 	u8 *mi_req;
406 	u8 *mi_resp;
407 	int res;
408 
409 	mi_req = alloc_smp_req(MI_REQ_SIZE);
410 	if (!mi_req)
411 		return -ENOMEM;
412 
413 	mi_resp = alloc_smp_resp(MI_RESP_SIZE);
414 	if (!mi_resp) {
415 		kfree(mi_req);
416 		return -ENOMEM;
417 	}
418 
419 	mi_req[1] = SMP_REPORT_MANUF_INFO;
420 
421 	res = smp_execute_task(dev, mi_req, MI_REQ_SIZE, mi_resp,MI_RESP_SIZE);
422 	if (res) {
423 		SAS_DPRINTK("MI: ex %016llx failed:0x%x\n",
424 			    SAS_ADDR(dev->sas_addr), res);
425 		goto out;
426 	} else if (mi_resp[2] != SMP_RESP_FUNC_ACC) {
427 		SAS_DPRINTK("MI ex %016llx returned SMP result:0x%x\n",
428 			    SAS_ADDR(dev->sas_addr), mi_resp[2]);
429 		goto out;
430 	}
431 
432 	ex_assign_manuf_info(dev, mi_resp);
433 out:
434 	kfree(mi_req);
435 	kfree(mi_resp);
436 	return res;
437 }
438 
439 #define PC_REQ_SIZE  44
440 #define PC_RESP_SIZE 8
441 
442 int sas_smp_phy_control(struct domain_device *dev, int phy_id,
443 			enum phy_func phy_func,
444 			struct sas_phy_linkrates *rates)
445 {
446 	u8 *pc_req;
447 	u8 *pc_resp;
448 	int res;
449 
450 	pc_req = alloc_smp_req(PC_REQ_SIZE);
451 	if (!pc_req)
452 		return -ENOMEM;
453 
454 	pc_resp = alloc_smp_resp(PC_RESP_SIZE);
455 	if (!pc_resp) {
456 		kfree(pc_req);
457 		return -ENOMEM;
458 	}
459 
460 	pc_req[1] = SMP_PHY_CONTROL;
461 	pc_req[9] = phy_id;
462 	pc_req[10]= phy_func;
463 	if (rates) {
464 		pc_req[32] = rates->minimum_linkrate << 4;
465 		pc_req[33] = rates->maximum_linkrate << 4;
466 	}
467 
468 	res = smp_execute_task(dev, pc_req, PC_REQ_SIZE, pc_resp,PC_RESP_SIZE);
469 
470 	kfree(pc_resp);
471 	kfree(pc_req);
472 	return res;
473 }
474 
475 static void sas_ex_disable_phy(struct domain_device *dev, int phy_id)
476 {
477 	struct expander_device *ex = &dev->ex_dev;
478 	struct ex_phy *phy = &ex->ex_phy[phy_id];
479 
480 	sas_smp_phy_control(dev, phy_id, PHY_FUNC_DISABLE, NULL);
481 	phy->linkrate = SAS_PHY_DISABLED;
482 }
483 
484 static void sas_ex_disable_port(struct domain_device *dev, u8 *sas_addr)
485 {
486 	struct expander_device *ex = &dev->ex_dev;
487 	int i;
488 
489 	for (i = 0; i < ex->num_phys; i++) {
490 		struct ex_phy *phy = &ex->ex_phy[i];
491 
492 		if (phy->phy_state == PHY_VACANT ||
493 		    phy->phy_state == PHY_NOT_PRESENT)
494 			continue;
495 
496 		if (SAS_ADDR(phy->attached_sas_addr) == SAS_ADDR(sas_addr))
497 			sas_ex_disable_phy(dev, i);
498 	}
499 }
500 
501 static int sas_dev_present_in_domain(struct asd_sas_port *port,
502 					    u8 *sas_addr)
503 {
504 	struct domain_device *dev;
505 
506 	if (SAS_ADDR(port->sas_addr) == SAS_ADDR(sas_addr))
507 		return 1;
508 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
509 		if (SAS_ADDR(dev->sas_addr) == SAS_ADDR(sas_addr))
510 			return 1;
511 	}
512 	return 0;
513 }
514 
515 #define RPEL_REQ_SIZE	16
516 #define RPEL_RESP_SIZE	32
517 int sas_smp_get_phy_events(struct sas_phy *phy)
518 {
519 	int res;
520 	u8 *req;
521 	u8 *resp;
522 	struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
523 	struct domain_device *dev = sas_find_dev_by_rphy(rphy);
524 
525 	req = alloc_smp_req(RPEL_REQ_SIZE);
526 	if (!req)
527 		return -ENOMEM;
528 
529 	resp = alloc_smp_resp(RPEL_RESP_SIZE);
530 	if (!resp) {
531 		kfree(req);
532 		return -ENOMEM;
533 	}
534 
535 	req[1] = SMP_REPORT_PHY_ERR_LOG;
536 	req[9] = phy->number;
537 
538 	res = smp_execute_task(dev, req, RPEL_REQ_SIZE,
539 			            resp, RPEL_RESP_SIZE);
540 
541 	if (!res)
542 		goto out;
543 
544 	phy->invalid_dword_count = scsi_to_u32(&resp[12]);
545 	phy->running_disparity_error_count = scsi_to_u32(&resp[16]);
546 	phy->loss_of_dword_sync_count = scsi_to_u32(&resp[20]);
547 	phy->phy_reset_problem_count = scsi_to_u32(&resp[24]);
548 
549  out:
550 	kfree(resp);
551 	return res;
552 
553 }
554 
555 #ifdef CONFIG_SCSI_SAS_ATA
556 
557 #define RPS_REQ_SIZE  16
558 #define RPS_RESP_SIZE 60
559 
560 static int sas_get_report_phy_sata(struct domain_device *dev,
561 					  int phy_id,
562 					  struct smp_resp *rps_resp)
563 {
564 	int res;
565 	u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE);
566 	u8 *resp = (u8 *)rps_resp;
567 
568 	if (!rps_req)
569 		return -ENOMEM;
570 
571 	rps_req[1] = SMP_REPORT_PHY_SATA;
572 	rps_req[9] = phy_id;
573 
574 	res = smp_execute_task(dev, rps_req, RPS_REQ_SIZE,
575 			            rps_resp, RPS_RESP_SIZE);
576 
577 	/* 0x34 is the FIS type for the D2H fis.  There's a potential
578 	 * standards cockup here.  sas-2 explicitly specifies the FIS
579 	 * should be encoded so that FIS type is in resp[24].
580 	 * However, some expanders endian reverse this.  Undo the
581 	 * reversal here */
582 	if (!res && resp[27] == 0x34 && resp[24] != 0x34) {
583 		int i;
584 
585 		for (i = 0; i < 5; i++) {
586 			int j = 24 + (i*4);
587 			u8 a, b;
588 			a = resp[j + 0];
589 			b = resp[j + 1];
590 			resp[j + 0] = resp[j + 3];
591 			resp[j + 1] = resp[j + 2];
592 			resp[j + 2] = b;
593 			resp[j + 3] = a;
594 		}
595 	}
596 
597 	kfree(rps_req);
598 	return res;
599 }
600 #endif
601 
602 static void sas_ex_get_linkrate(struct domain_device *parent,
603 				       struct domain_device *child,
604 				       struct ex_phy *parent_phy)
605 {
606 	struct expander_device *parent_ex = &parent->ex_dev;
607 	struct sas_port *port;
608 	int i;
609 
610 	child->pathways = 0;
611 
612 	port = parent_phy->port;
613 
614 	for (i = 0; i < parent_ex->num_phys; i++) {
615 		struct ex_phy *phy = &parent_ex->ex_phy[i];
616 
617 		if (phy->phy_state == PHY_VACANT ||
618 		    phy->phy_state == PHY_NOT_PRESENT)
619 			continue;
620 
621 		if (SAS_ADDR(phy->attached_sas_addr) ==
622 		    SAS_ADDR(child->sas_addr)) {
623 
624 			child->min_linkrate = min(parent->min_linkrate,
625 						  phy->linkrate);
626 			child->max_linkrate = max(parent->max_linkrate,
627 						  phy->linkrate);
628 			child->pathways++;
629 			sas_port_add_phy(port, phy->phy);
630 		}
631 	}
632 	child->linkrate = min(parent_phy->linkrate, child->max_linkrate);
633 	child->pathways = min(child->pathways, parent->pathways);
634 }
635 
636 static struct domain_device *sas_ex_discover_end_dev(
637 	struct domain_device *parent, int phy_id)
638 {
639 	struct expander_device *parent_ex = &parent->ex_dev;
640 	struct ex_phy *phy = &parent_ex->ex_phy[phy_id];
641 	struct domain_device *child = NULL;
642 	struct sas_rphy *rphy;
643 	int res;
644 
645 	if (phy->attached_sata_host || phy->attached_sata_ps)
646 		return NULL;
647 
648 	child = kzalloc(sizeof(*child), GFP_KERNEL);
649 	if (!child)
650 		return NULL;
651 
652 	child->parent = parent;
653 	child->port   = parent->port;
654 	child->iproto = phy->attached_iproto;
655 	memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
656 	sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
657 	if (!phy->port) {
658 		phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
659 		if (unlikely(!phy->port))
660 			goto out_err;
661 		if (unlikely(sas_port_add(phy->port) != 0)) {
662 			sas_port_free(phy->port);
663 			goto out_err;
664 		}
665 	}
666 	sas_ex_get_linkrate(parent, child, phy);
667 
668 #ifdef CONFIG_SCSI_SAS_ATA
669 	if ((phy->attached_tproto & SAS_PROTOCOL_STP) || phy->attached_sata_dev) {
670 		child->dev_type = SATA_DEV;
671 		if (phy->attached_tproto & SAS_PROTOCOL_STP)
672 			child->tproto = phy->attached_tproto;
673 		if (phy->attached_sata_dev)
674 			child->tproto |= SATA_DEV;
675 		res = sas_get_report_phy_sata(parent, phy_id,
676 					      &child->sata_dev.rps_resp);
677 		if (res) {
678 			SAS_DPRINTK("report phy sata to %016llx:0x%x returned "
679 				    "0x%x\n", SAS_ADDR(parent->sas_addr),
680 				    phy_id, res);
681 			goto out_free;
682 		}
683 		memcpy(child->frame_rcvd, &child->sata_dev.rps_resp.rps.fis,
684 		       sizeof(struct dev_to_host_fis));
685 
686 		rphy = sas_end_device_alloc(phy->port);
687 		if (unlikely(!rphy))
688 			goto out_free;
689 
690 		sas_init_dev(child);
691 
692 		child->rphy = rphy;
693 
694 		spin_lock_irq(&parent->port->dev_list_lock);
695 		list_add_tail(&child->dev_list_node, &parent->port->dev_list);
696 		spin_unlock_irq(&parent->port->dev_list_lock);
697 
698 		res = sas_discover_sata(child);
699 		if (res) {
700 			SAS_DPRINTK("sas_discover_sata() for device %16llx at "
701 				    "%016llx:0x%x returned 0x%x\n",
702 				    SAS_ADDR(child->sas_addr),
703 				    SAS_ADDR(parent->sas_addr), phy_id, res);
704 			goto out_list_del;
705 		}
706 	} else
707 #endif
708 	  if (phy->attached_tproto & SAS_PROTOCOL_SSP) {
709 		child->dev_type = SAS_END_DEV;
710 		rphy = sas_end_device_alloc(phy->port);
711 		/* FIXME: error handling */
712 		if (unlikely(!rphy))
713 			goto out_free;
714 		child->tproto = phy->attached_tproto;
715 		sas_init_dev(child);
716 
717 		child->rphy = rphy;
718 		sas_fill_in_rphy(child, rphy);
719 
720 		spin_lock_irq(&parent->port->dev_list_lock);
721 		list_add_tail(&child->dev_list_node, &parent->port->dev_list);
722 		spin_unlock_irq(&parent->port->dev_list_lock);
723 
724 		res = sas_discover_end_dev(child);
725 		if (res) {
726 			SAS_DPRINTK("sas_discover_end_dev() for device %16llx "
727 				    "at %016llx:0x%x returned 0x%x\n",
728 				    SAS_ADDR(child->sas_addr),
729 				    SAS_ADDR(parent->sas_addr), phy_id, res);
730 			goto out_list_del;
731 		}
732 	} else {
733 		SAS_DPRINTK("target proto 0x%x at %016llx:0x%x not handled\n",
734 			    phy->attached_tproto, SAS_ADDR(parent->sas_addr),
735 			    phy_id);
736 		goto out_free;
737 	}
738 
739 	list_add_tail(&child->siblings, &parent_ex->children);
740 	return child;
741 
742  out_list_del:
743 	sas_rphy_free(child->rphy);
744 	child->rphy = NULL;
745 	list_del(&child->dev_list_node);
746  out_free:
747 	sas_port_delete(phy->port);
748  out_err:
749 	phy->port = NULL;
750 	kfree(child);
751 	return NULL;
752 }
753 
754 /* See if this phy is part of a wide port */
755 static int sas_ex_join_wide_port(struct domain_device *parent, int phy_id)
756 {
757 	struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
758 	int i;
759 
760 	for (i = 0; i < parent->ex_dev.num_phys; i++) {
761 		struct ex_phy *ephy = &parent->ex_dev.ex_phy[i];
762 
763 		if (ephy == phy)
764 			continue;
765 
766 		if (!memcmp(phy->attached_sas_addr, ephy->attached_sas_addr,
767 			    SAS_ADDR_SIZE) && ephy->port) {
768 			sas_port_add_phy(ephy->port, phy->phy);
769 			phy->phy_state = PHY_DEVICE_DISCOVERED;
770 			return 0;
771 		}
772 	}
773 
774 	return -ENODEV;
775 }
776 
777 static struct domain_device *sas_ex_discover_expander(
778 	struct domain_device *parent, int phy_id)
779 {
780 	struct sas_expander_device *parent_ex = rphy_to_expander_device(parent->rphy);
781 	struct ex_phy *phy = &parent->ex_dev.ex_phy[phy_id];
782 	struct domain_device *child = NULL;
783 	struct sas_rphy *rphy;
784 	struct sas_expander_device *edev;
785 	struct asd_sas_port *port;
786 	int res;
787 
788 	if (phy->routing_attr == DIRECT_ROUTING) {
789 		SAS_DPRINTK("ex %016llx:0x%x:D <--> ex %016llx:0x%x is not "
790 			    "allowed\n",
791 			    SAS_ADDR(parent->sas_addr), phy_id,
792 			    SAS_ADDR(phy->attached_sas_addr),
793 			    phy->attached_phy_id);
794 		return NULL;
795 	}
796 	child = kzalloc(sizeof(*child), GFP_KERNEL);
797 	if (!child)
798 		return NULL;
799 
800 	phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
801 	/* FIXME: better error handling */
802 	BUG_ON(sas_port_add(phy->port) != 0);
803 
804 
805 	switch (phy->attached_dev_type) {
806 	case EDGE_DEV:
807 		rphy = sas_expander_alloc(phy->port,
808 					  SAS_EDGE_EXPANDER_DEVICE);
809 		break;
810 	case FANOUT_DEV:
811 		rphy = sas_expander_alloc(phy->port,
812 					  SAS_FANOUT_EXPANDER_DEVICE);
813 		break;
814 	default:
815 		rphy = NULL;	/* shut gcc up */
816 		BUG();
817 	}
818 	port = parent->port;
819 	child->rphy = rphy;
820 	edev = rphy_to_expander_device(rphy);
821 	child->dev_type = phy->attached_dev_type;
822 	child->parent = parent;
823 	child->port = port;
824 	child->iproto = phy->attached_iproto;
825 	child->tproto = phy->attached_tproto;
826 	memcpy(child->sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE);
827 	sas_hash_addr(child->hashed_sas_addr, child->sas_addr);
828 	sas_ex_get_linkrate(parent, child, phy);
829 	edev->level = parent_ex->level + 1;
830 	parent->port->disc.max_level = max(parent->port->disc.max_level,
831 					   edev->level);
832 	sas_init_dev(child);
833 	sas_fill_in_rphy(child, rphy);
834 	sas_rphy_add(rphy);
835 
836 	spin_lock_irq(&parent->port->dev_list_lock);
837 	list_add_tail(&child->dev_list_node, &parent->port->dev_list);
838 	spin_unlock_irq(&parent->port->dev_list_lock);
839 
840 	res = sas_discover_expander(child);
841 	if (res) {
842 		kfree(child);
843 		return NULL;
844 	}
845 	list_add_tail(&child->siblings, &parent->ex_dev.children);
846 	return child;
847 }
848 
849 static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
850 {
851 	struct expander_device *ex = &dev->ex_dev;
852 	struct ex_phy *ex_phy = &ex->ex_phy[phy_id];
853 	struct domain_device *child = NULL;
854 	int res = 0;
855 
856 	/* Phy state */
857 	if (ex_phy->linkrate == SAS_SATA_SPINUP_HOLD) {
858 		if (!sas_smp_phy_control(dev, phy_id, PHY_FUNC_LINK_RESET, NULL))
859 			res = sas_ex_phy_discover(dev, phy_id);
860 		if (res)
861 			return res;
862 	}
863 
864 	/* Parent and domain coherency */
865 	if (!dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
866 			     SAS_ADDR(dev->port->sas_addr))) {
867 		sas_add_parent_port(dev, phy_id);
868 		return 0;
869 	}
870 	if (dev->parent && (SAS_ADDR(ex_phy->attached_sas_addr) ==
871 			    SAS_ADDR(dev->parent->sas_addr))) {
872 		sas_add_parent_port(dev, phy_id);
873 		if (ex_phy->routing_attr == TABLE_ROUTING)
874 			sas_configure_phy(dev, phy_id, dev->port->sas_addr, 1);
875 		return 0;
876 	}
877 
878 	if (sas_dev_present_in_domain(dev->port, ex_phy->attached_sas_addr))
879 		sas_ex_disable_port(dev, ex_phy->attached_sas_addr);
880 
881 	if (ex_phy->attached_dev_type == NO_DEVICE) {
882 		if (ex_phy->routing_attr == DIRECT_ROUTING) {
883 			memset(ex_phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
884 			sas_configure_routing(dev, ex_phy->attached_sas_addr);
885 		}
886 		return 0;
887 	} else if (ex_phy->linkrate == SAS_LINK_RATE_UNKNOWN)
888 		return 0;
889 
890 	if (ex_phy->attached_dev_type != SAS_END_DEV &&
891 	    ex_phy->attached_dev_type != FANOUT_DEV &&
892 	    ex_phy->attached_dev_type != EDGE_DEV) {
893 		SAS_DPRINTK("unknown device type(0x%x) attached to ex %016llx "
894 			    "phy 0x%x\n", ex_phy->attached_dev_type,
895 			    SAS_ADDR(dev->sas_addr),
896 			    phy_id);
897 		return 0;
898 	}
899 
900 	res = sas_configure_routing(dev, ex_phy->attached_sas_addr);
901 	if (res) {
902 		SAS_DPRINTK("configure routing for dev %016llx "
903 			    "reported 0x%x. Forgotten\n",
904 			    SAS_ADDR(ex_phy->attached_sas_addr), res);
905 		sas_disable_routing(dev, ex_phy->attached_sas_addr);
906 		return res;
907 	}
908 
909 	res = sas_ex_join_wide_port(dev, phy_id);
910 	if (!res) {
911 		SAS_DPRINTK("Attaching ex phy%d to wide port %016llx\n",
912 			    phy_id, SAS_ADDR(ex_phy->attached_sas_addr));
913 		return res;
914 	}
915 
916 	switch (ex_phy->attached_dev_type) {
917 	case SAS_END_DEV:
918 		child = sas_ex_discover_end_dev(dev, phy_id);
919 		break;
920 	case FANOUT_DEV:
921 		if (SAS_ADDR(dev->port->disc.fanout_sas_addr)) {
922 			SAS_DPRINTK("second fanout expander %016llx phy 0x%x "
923 				    "attached to ex %016llx phy 0x%x\n",
924 				    SAS_ADDR(ex_phy->attached_sas_addr),
925 				    ex_phy->attached_phy_id,
926 				    SAS_ADDR(dev->sas_addr),
927 				    phy_id);
928 			sas_ex_disable_phy(dev, phy_id);
929 			break;
930 		} else
931 			memcpy(dev->port->disc.fanout_sas_addr,
932 			       ex_phy->attached_sas_addr, SAS_ADDR_SIZE);
933 		/* fallthrough */
934 	case EDGE_DEV:
935 		child = sas_ex_discover_expander(dev, phy_id);
936 		break;
937 	default:
938 		break;
939 	}
940 
941 	if (child) {
942 		int i;
943 
944 		for (i = 0; i < ex->num_phys; i++) {
945 			if (ex->ex_phy[i].phy_state == PHY_VACANT ||
946 			    ex->ex_phy[i].phy_state == PHY_NOT_PRESENT)
947 				continue;
948 
949 			if (SAS_ADDR(ex->ex_phy[i].attached_sas_addr) ==
950 			    SAS_ADDR(child->sas_addr))
951 				ex->ex_phy[i].phy_state= PHY_DEVICE_DISCOVERED;
952 		}
953 	}
954 
955 	return res;
956 }
957 
958 static int sas_find_sub_addr(struct domain_device *dev, u8 *sub_addr)
959 {
960 	struct expander_device *ex = &dev->ex_dev;
961 	int i;
962 
963 	for (i = 0; i < ex->num_phys; i++) {
964 		struct ex_phy *phy = &ex->ex_phy[i];
965 
966 		if (phy->phy_state == PHY_VACANT ||
967 		    phy->phy_state == PHY_NOT_PRESENT)
968 			continue;
969 
970 		if ((phy->attached_dev_type == EDGE_DEV ||
971 		     phy->attached_dev_type == FANOUT_DEV) &&
972 		    phy->routing_attr == SUBTRACTIVE_ROUTING) {
973 
974 			memcpy(sub_addr, phy->attached_sas_addr,SAS_ADDR_SIZE);
975 
976 			return 1;
977 		}
978 	}
979 	return 0;
980 }
981 
982 static int sas_check_level_subtractive_boundary(struct domain_device *dev)
983 {
984 	struct expander_device *ex = &dev->ex_dev;
985 	struct domain_device *child;
986 	u8 sub_addr[8] = {0, };
987 
988 	list_for_each_entry(child, &ex->children, siblings) {
989 		if (child->dev_type != EDGE_DEV &&
990 		    child->dev_type != FANOUT_DEV)
991 			continue;
992 		if (sub_addr[0] == 0) {
993 			sas_find_sub_addr(child, sub_addr);
994 			continue;
995 		} else {
996 			u8 s2[8];
997 
998 			if (sas_find_sub_addr(child, s2) &&
999 			    (SAS_ADDR(sub_addr) != SAS_ADDR(s2))) {
1000 
1001 				SAS_DPRINTK("ex %016llx->%016llx-?->%016llx "
1002 					    "diverges from subtractive "
1003 					    "boundary %016llx\n",
1004 					    SAS_ADDR(dev->sas_addr),
1005 					    SAS_ADDR(child->sas_addr),
1006 					    SAS_ADDR(s2),
1007 					    SAS_ADDR(sub_addr));
1008 
1009 				sas_ex_disable_port(child, s2);
1010 			}
1011 		}
1012 	}
1013 	return 0;
1014 }
1015 /**
1016  * sas_ex_discover_devices -- discover devices attached to this expander
1017  * dev: pointer to the expander domain device
1018  * single: if you want to do a single phy, else set to -1;
1019  *
1020  * Configure this expander for use with its devices and register the
1021  * devices of this expander.
1022  */
1023 static int sas_ex_discover_devices(struct domain_device *dev, int single)
1024 {
1025 	struct expander_device *ex = &dev->ex_dev;
1026 	int i = 0, end = ex->num_phys;
1027 	int res = 0;
1028 
1029 	if (0 <= single && single < end) {
1030 		i = single;
1031 		end = i+1;
1032 	}
1033 
1034 	for ( ; i < end; i++) {
1035 		struct ex_phy *ex_phy = &ex->ex_phy[i];
1036 
1037 		if (ex_phy->phy_state == PHY_VACANT ||
1038 		    ex_phy->phy_state == PHY_NOT_PRESENT ||
1039 		    ex_phy->phy_state == PHY_DEVICE_DISCOVERED)
1040 			continue;
1041 
1042 		switch (ex_phy->linkrate) {
1043 		case SAS_PHY_DISABLED:
1044 		case SAS_PHY_RESET_PROBLEM:
1045 		case SAS_SATA_PORT_SELECTOR:
1046 			continue;
1047 		default:
1048 			res = sas_ex_discover_dev(dev, i);
1049 			if (res)
1050 				break;
1051 			continue;
1052 		}
1053 	}
1054 
1055 	if (!res)
1056 		sas_check_level_subtractive_boundary(dev);
1057 
1058 	return res;
1059 }
1060 
1061 static int sas_check_ex_subtractive_boundary(struct domain_device *dev)
1062 {
1063 	struct expander_device *ex = &dev->ex_dev;
1064 	int i;
1065 	u8  *sub_sas_addr = NULL;
1066 
1067 	if (dev->dev_type != EDGE_DEV)
1068 		return 0;
1069 
1070 	for (i = 0; i < ex->num_phys; i++) {
1071 		struct ex_phy *phy = &ex->ex_phy[i];
1072 
1073 		if (phy->phy_state == PHY_VACANT ||
1074 		    phy->phy_state == PHY_NOT_PRESENT)
1075 			continue;
1076 
1077 		if ((phy->attached_dev_type == FANOUT_DEV ||
1078 		     phy->attached_dev_type == EDGE_DEV) &&
1079 		    phy->routing_attr == SUBTRACTIVE_ROUTING) {
1080 
1081 			if (!sub_sas_addr)
1082 				sub_sas_addr = &phy->attached_sas_addr[0];
1083 			else if (SAS_ADDR(sub_sas_addr) !=
1084 				 SAS_ADDR(phy->attached_sas_addr)) {
1085 
1086 				SAS_DPRINTK("ex %016llx phy 0x%x "
1087 					    "diverges(%016llx) on subtractive "
1088 					    "boundary(%016llx). Disabled\n",
1089 					    SAS_ADDR(dev->sas_addr), i,
1090 					    SAS_ADDR(phy->attached_sas_addr),
1091 					    SAS_ADDR(sub_sas_addr));
1092 				sas_ex_disable_phy(dev, i);
1093 			}
1094 		}
1095 	}
1096 	return 0;
1097 }
1098 
1099 static void sas_print_parent_topology_bug(struct domain_device *child,
1100 						 struct ex_phy *parent_phy,
1101 						 struct ex_phy *child_phy)
1102 {
1103 	static const char ra_char[] = {
1104 		[DIRECT_ROUTING] = 'D',
1105 		[SUBTRACTIVE_ROUTING] = 'S',
1106 		[TABLE_ROUTING] = 'T',
1107 	};
1108 	static const char *ex_type[] = {
1109 		[EDGE_DEV] = "edge",
1110 		[FANOUT_DEV] = "fanout",
1111 	};
1112 	struct domain_device *parent = child->parent;
1113 
1114 	sas_printk("%s ex %016llx phy 0x%x <--> %s ex %016llx phy 0x%x "
1115 		   "has %c:%c routing link!\n",
1116 
1117 		   ex_type[parent->dev_type],
1118 		   SAS_ADDR(parent->sas_addr),
1119 		   parent_phy->phy_id,
1120 
1121 		   ex_type[child->dev_type],
1122 		   SAS_ADDR(child->sas_addr),
1123 		   child_phy->phy_id,
1124 
1125 		   ra_char[parent_phy->routing_attr],
1126 		   ra_char[child_phy->routing_attr]);
1127 }
1128 
1129 static int sas_check_eeds(struct domain_device *child,
1130 				 struct ex_phy *parent_phy,
1131 				 struct ex_phy *child_phy)
1132 {
1133 	int res = 0;
1134 	struct domain_device *parent = child->parent;
1135 
1136 	if (SAS_ADDR(parent->port->disc.fanout_sas_addr) != 0) {
1137 		res = -ENODEV;
1138 		SAS_DPRINTK("edge ex %016llx phy S:0x%x <--> edge ex %016llx "
1139 			    "phy S:0x%x, while there is a fanout ex %016llx\n",
1140 			    SAS_ADDR(parent->sas_addr),
1141 			    parent_phy->phy_id,
1142 			    SAS_ADDR(child->sas_addr),
1143 			    child_phy->phy_id,
1144 			    SAS_ADDR(parent->port->disc.fanout_sas_addr));
1145 	} else if (SAS_ADDR(parent->port->disc.eeds_a) == 0) {
1146 		memcpy(parent->port->disc.eeds_a, parent->sas_addr,
1147 		       SAS_ADDR_SIZE);
1148 		memcpy(parent->port->disc.eeds_b, child->sas_addr,
1149 		       SAS_ADDR_SIZE);
1150 	} else if (((SAS_ADDR(parent->port->disc.eeds_a) ==
1151 		    SAS_ADDR(parent->sas_addr)) ||
1152 		   (SAS_ADDR(parent->port->disc.eeds_a) ==
1153 		    SAS_ADDR(child->sas_addr)))
1154 		   &&
1155 		   ((SAS_ADDR(parent->port->disc.eeds_b) ==
1156 		     SAS_ADDR(parent->sas_addr)) ||
1157 		    (SAS_ADDR(parent->port->disc.eeds_b) ==
1158 		     SAS_ADDR(child->sas_addr))))
1159 		;
1160 	else {
1161 		res = -ENODEV;
1162 		SAS_DPRINTK("edge ex %016llx phy 0x%x <--> edge ex %016llx "
1163 			    "phy 0x%x link forms a third EEDS!\n",
1164 			    SAS_ADDR(parent->sas_addr),
1165 			    parent_phy->phy_id,
1166 			    SAS_ADDR(child->sas_addr),
1167 			    child_phy->phy_id);
1168 	}
1169 
1170 	return res;
1171 }
1172 
1173 /* Here we spill over 80 columns.  It is intentional.
1174  */
1175 static int sas_check_parent_topology(struct domain_device *child)
1176 {
1177 	struct expander_device *child_ex = &child->ex_dev;
1178 	struct expander_device *parent_ex;
1179 	int i;
1180 	int res = 0;
1181 
1182 	if (!child->parent)
1183 		return 0;
1184 
1185 	if (child->parent->dev_type != EDGE_DEV &&
1186 	    child->parent->dev_type != FANOUT_DEV)
1187 		return 0;
1188 
1189 	parent_ex = &child->parent->ex_dev;
1190 
1191 	for (i = 0; i < parent_ex->num_phys; i++) {
1192 		struct ex_phy *parent_phy = &parent_ex->ex_phy[i];
1193 		struct ex_phy *child_phy;
1194 
1195 		if (parent_phy->phy_state == PHY_VACANT ||
1196 		    parent_phy->phy_state == PHY_NOT_PRESENT)
1197 			continue;
1198 
1199 		if (SAS_ADDR(parent_phy->attached_sas_addr) != SAS_ADDR(child->sas_addr))
1200 			continue;
1201 
1202 		child_phy = &child_ex->ex_phy[parent_phy->attached_phy_id];
1203 
1204 		switch (child->parent->dev_type) {
1205 		case EDGE_DEV:
1206 			if (child->dev_type == FANOUT_DEV) {
1207 				if (parent_phy->routing_attr != SUBTRACTIVE_ROUTING ||
1208 				    child_phy->routing_attr != TABLE_ROUTING) {
1209 					sas_print_parent_topology_bug(child, parent_phy, child_phy);
1210 					res = -ENODEV;
1211 				}
1212 			} else if (parent_phy->routing_attr == SUBTRACTIVE_ROUTING) {
1213 				if (child_phy->routing_attr == SUBTRACTIVE_ROUTING) {
1214 					res = sas_check_eeds(child, parent_phy, child_phy);
1215 				} else if (child_phy->routing_attr != TABLE_ROUTING) {
1216 					sas_print_parent_topology_bug(child, parent_phy, child_phy);
1217 					res = -ENODEV;
1218 				}
1219 			} else if (parent_phy->routing_attr == TABLE_ROUTING &&
1220 				   child_phy->routing_attr != SUBTRACTIVE_ROUTING) {
1221 				sas_print_parent_topology_bug(child, parent_phy, child_phy);
1222 				res = -ENODEV;
1223 			}
1224 			break;
1225 		case FANOUT_DEV:
1226 			if (parent_phy->routing_attr != TABLE_ROUTING ||
1227 			    child_phy->routing_attr != SUBTRACTIVE_ROUTING) {
1228 				sas_print_parent_topology_bug(child, parent_phy, child_phy);
1229 				res = -ENODEV;
1230 			}
1231 			break;
1232 		default:
1233 			break;
1234 		}
1235 	}
1236 
1237 	return res;
1238 }
1239 
1240 #define RRI_REQ_SIZE  16
1241 #define RRI_RESP_SIZE 44
1242 
1243 static int sas_configure_present(struct domain_device *dev, int phy_id,
1244 				 u8 *sas_addr, int *index, int *present)
1245 {
1246 	int i, res = 0;
1247 	struct expander_device *ex = &dev->ex_dev;
1248 	struct ex_phy *phy = &ex->ex_phy[phy_id];
1249 	u8 *rri_req;
1250 	u8 *rri_resp;
1251 
1252 	*present = 0;
1253 	*index = 0;
1254 
1255 	rri_req = alloc_smp_req(RRI_REQ_SIZE);
1256 	if (!rri_req)
1257 		return -ENOMEM;
1258 
1259 	rri_resp = alloc_smp_resp(RRI_RESP_SIZE);
1260 	if (!rri_resp) {
1261 		kfree(rri_req);
1262 		return -ENOMEM;
1263 	}
1264 
1265 	rri_req[1] = SMP_REPORT_ROUTE_INFO;
1266 	rri_req[9] = phy_id;
1267 
1268 	for (i = 0; i < ex->max_route_indexes ; i++) {
1269 		*(__be16 *)(rri_req+6) = cpu_to_be16(i);
1270 		res = smp_execute_task(dev, rri_req, RRI_REQ_SIZE, rri_resp,
1271 				       RRI_RESP_SIZE);
1272 		if (res)
1273 			goto out;
1274 		res = rri_resp[2];
1275 		if (res == SMP_RESP_NO_INDEX) {
1276 			SAS_DPRINTK("overflow of indexes: dev %016llx "
1277 				    "phy 0x%x index 0x%x\n",
1278 				    SAS_ADDR(dev->sas_addr), phy_id, i);
1279 			goto out;
1280 		} else if (res != SMP_RESP_FUNC_ACC) {
1281 			SAS_DPRINTK("%s: dev %016llx phy 0x%x index 0x%x "
1282 				    "result 0x%x\n", __func__,
1283 				    SAS_ADDR(dev->sas_addr), phy_id, i, res);
1284 			goto out;
1285 		}
1286 		if (SAS_ADDR(sas_addr) != 0) {
1287 			if (SAS_ADDR(rri_resp+16) == SAS_ADDR(sas_addr)) {
1288 				*index = i;
1289 				if ((rri_resp[12] & 0x80) == 0x80)
1290 					*present = 0;
1291 				else
1292 					*present = 1;
1293 				goto out;
1294 			} else if (SAS_ADDR(rri_resp+16) == 0) {
1295 				*index = i;
1296 				*present = 0;
1297 				goto out;
1298 			}
1299 		} else if (SAS_ADDR(rri_resp+16) == 0 &&
1300 			   phy->last_da_index < i) {
1301 			phy->last_da_index = i;
1302 			*index = i;
1303 			*present = 0;
1304 			goto out;
1305 		}
1306 	}
1307 	res = -1;
1308 out:
1309 	kfree(rri_req);
1310 	kfree(rri_resp);
1311 	return res;
1312 }
1313 
1314 #define CRI_REQ_SIZE  44
1315 #define CRI_RESP_SIZE  8
1316 
1317 static int sas_configure_set(struct domain_device *dev, int phy_id,
1318 			     u8 *sas_addr, int index, int include)
1319 {
1320 	int res;
1321 	u8 *cri_req;
1322 	u8 *cri_resp;
1323 
1324 	cri_req = alloc_smp_req(CRI_REQ_SIZE);
1325 	if (!cri_req)
1326 		return -ENOMEM;
1327 
1328 	cri_resp = alloc_smp_resp(CRI_RESP_SIZE);
1329 	if (!cri_resp) {
1330 		kfree(cri_req);
1331 		return -ENOMEM;
1332 	}
1333 
1334 	cri_req[1] = SMP_CONF_ROUTE_INFO;
1335 	*(__be16 *)(cri_req+6) = cpu_to_be16(index);
1336 	cri_req[9] = phy_id;
1337 	if (SAS_ADDR(sas_addr) == 0 || !include)
1338 		cri_req[12] |= 0x80;
1339 	memcpy(cri_req+16, sas_addr, SAS_ADDR_SIZE);
1340 
1341 	res = smp_execute_task(dev, cri_req, CRI_REQ_SIZE, cri_resp,
1342 			       CRI_RESP_SIZE);
1343 	if (res)
1344 		goto out;
1345 	res = cri_resp[2];
1346 	if (res == SMP_RESP_NO_INDEX) {
1347 		SAS_DPRINTK("overflow of indexes: dev %016llx phy 0x%x "
1348 			    "index 0x%x\n",
1349 			    SAS_ADDR(dev->sas_addr), phy_id, index);
1350 	}
1351 out:
1352 	kfree(cri_req);
1353 	kfree(cri_resp);
1354 	return res;
1355 }
1356 
1357 static int sas_configure_phy(struct domain_device *dev, int phy_id,
1358 				    u8 *sas_addr, int include)
1359 {
1360 	int index;
1361 	int present;
1362 	int res;
1363 
1364 	res = sas_configure_present(dev, phy_id, sas_addr, &index, &present);
1365 	if (res)
1366 		return res;
1367 	if (include ^ present)
1368 		return sas_configure_set(dev, phy_id, sas_addr, index,include);
1369 
1370 	return res;
1371 }
1372 
1373 /**
1374  * sas_configure_parent -- configure routing table of parent
1375  * parent: parent expander
1376  * child: child expander
1377  * sas_addr: SAS port identifier of device directly attached to child
1378  */
1379 static int sas_configure_parent(struct domain_device *parent,
1380 				struct domain_device *child,
1381 				u8 *sas_addr, int include)
1382 {
1383 	struct expander_device *ex_parent = &parent->ex_dev;
1384 	int res = 0;
1385 	int i;
1386 
1387 	if (parent->parent) {
1388 		res = sas_configure_parent(parent->parent, parent, sas_addr,
1389 					   include);
1390 		if (res)
1391 			return res;
1392 	}
1393 
1394 	if (ex_parent->conf_route_table == 0) {
1395 		SAS_DPRINTK("ex %016llx has self-configuring routing table\n",
1396 			    SAS_ADDR(parent->sas_addr));
1397 		return 0;
1398 	}
1399 
1400 	for (i = 0; i < ex_parent->num_phys; i++) {
1401 		struct ex_phy *phy = &ex_parent->ex_phy[i];
1402 
1403 		if ((phy->routing_attr == TABLE_ROUTING) &&
1404 		    (SAS_ADDR(phy->attached_sas_addr) ==
1405 		     SAS_ADDR(child->sas_addr))) {
1406 			res = sas_configure_phy(parent, i, sas_addr, include);
1407 			if (res)
1408 				return res;
1409 		}
1410 	}
1411 
1412 	return res;
1413 }
1414 
1415 /**
1416  * sas_configure_routing -- configure routing
1417  * dev: expander device
1418  * sas_addr: port identifier of device directly attached to the expander device
1419  */
1420 static int sas_configure_routing(struct domain_device *dev, u8 *sas_addr)
1421 {
1422 	if (dev->parent)
1423 		return sas_configure_parent(dev->parent, dev, sas_addr, 1);
1424 	return 0;
1425 }
1426 
1427 static int sas_disable_routing(struct domain_device *dev,  u8 *sas_addr)
1428 {
1429 	if (dev->parent)
1430 		return sas_configure_parent(dev->parent, dev, sas_addr, 0);
1431 	return 0;
1432 }
1433 
1434 /**
1435  * sas_discover_expander -- expander discovery
1436  * @ex: pointer to expander domain device
1437  *
1438  * See comment in sas_discover_sata().
1439  */
1440 static int sas_discover_expander(struct domain_device *dev)
1441 {
1442 	int res;
1443 
1444 	res = sas_notify_lldd_dev_found(dev);
1445 	if (res)
1446 		return res;
1447 
1448 	res = sas_ex_general(dev);
1449 	if (res)
1450 		goto out_err;
1451 	res = sas_ex_manuf_info(dev);
1452 	if (res)
1453 		goto out_err;
1454 
1455 	res = sas_expander_discover(dev);
1456 	if (res) {
1457 		SAS_DPRINTK("expander %016llx discovery failed(0x%x)\n",
1458 			    SAS_ADDR(dev->sas_addr), res);
1459 		goto out_err;
1460 	}
1461 
1462 	sas_check_ex_subtractive_boundary(dev);
1463 	res = sas_check_parent_topology(dev);
1464 	if (res)
1465 		goto out_err;
1466 	return 0;
1467 out_err:
1468 	sas_notify_lldd_dev_gone(dev);
1469 	return res;
1470 }
1471 
1472 static int sas_ex_level_discovery(struct asd_sas_port *port, const int level)
1473 {
1474 	int res = 0;
1475 	struct domain_device *dev;
1476 
1477 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
1478 		if (dev->dev_type == EDGE_DEV ||
1479 		    dev->dev_type == FANOUT_DEV) {
1480 			struct sas_expander_device *ex =
1481 				rphy_to_expander_device(dev->rphy);
1482 
1483 			if (level == ex->level)
1484 				res = sas_ex_discover_devices(dev, -1);
1485 			else if (level > 0)
1486 				res = sas_ex_discover_devices(port->port_dev, -1);
1487 
1488 		}
1489 	}
1490 
1491 	return res;
1492 }
1493 
1494 static int sas_ex_bfs_disc(struct asd_sas_port *port)
1495 {
1496 	int res;
1497 	int level;
1498 
1499 	do {
1500 		level = port->disc.max_level;
1501 		res = sas_ex_level_discovery(port, level);
1502 		mb();
1503 	} while (level < port->disc.max_level);
1504 
1505 	return res;
1506 }
1507 
1508 int sas_discover_root_expander(struct domain_device *dev)
1509 {
1510 	int res;
1511 	struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);
1512 
1513 	res = sas_rphy_add(dev->rphy);
1514 	if (res)
1515 		goto out_err;
1516 
1517 	ex->level = dev->port->disc.max_level; /* 0 */
1518 	res = sas_discover_expander(dev);
1519 	if (res)
1520 		goto out_err2;
1521 
1522 	sas_ex_bfs_disc(dev->port);
1523 
1524 	return res;
1525 
1526 out_err2:
1527 	sas_rphy_remove(dev->rphy);
1528 out_err:
1529 	return res;
1530 }
1531 
1532 /* ---------- Domain revalidation ---------- */
1533 
1534 static int sas_get_phy_discover(struct domain_device *dev,
1535 				int phy_id, struct smp_resp *disc_resp)
1536 {
1537 	int res;
1538 	u8 *disc_req;
1539 
1540 	disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
1541 	if (!disc_req)
1542 		return -ENOMEM;
1543 
1544 	disc_req[1] = SMP_DISCOVER;
1545 	disc_req[9] = phy_id;
1546 
1547 	res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE,
1548 			       disc_resp, DISCOVER_RESP_SIZE);
1549 	if (res)
1550 		goto out;
1551 	else if (disc_resp->result != SMP_RESP_FUNC_ACC) {
1552 		res = disc_resp->result;
1553 		goto out;
1554 	}
1555 out:
1556 	kfree(disc_req);
1557 	return res;
1558 }
1559 
1560 static int sas_get_phy_change_count(struct domain_device *dev,
1561 				    int phy_id, int *pcc)
1562 {
1563 	int res;
1564 	struct smp_resp *disc_resp;
1565 
1566 	disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
1567 	if (!disc_resp)
1568 		return -ENOMEM;
1569 
1570 	res = sas_get_phy_discover(dev, phy_id, disc_resp);
1571 	if (!res)
1572 		*pcc = disc_resp->disc.change_count;
1573 
1574 	kfree(disc_resp);
1575 	return res;
1576 }
1577 
1578 static int sas_get_phy_attached_sas_addr(struct domain_device *dev,
1579 					 int phy_id, u8 *attached_sas_addr)
1580 {
1581 	int res;
1582 	struct smp_resp *disc_resp;
1583 	struct discover_resp *dr;
1584 
1585 	disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
1586 	if (!disc_resp)
1587 		return -ENOMEM;
1588 	dr = &disc_resp->disc;
1589 
1590 	res = sas_get_phy_discover(dev, phy_id, disc_resp);
1591 	if (!res) {
1592 		memcpy(attached_sas_addr,disc_resp->disc.attached_sas_addr,8);
1593 		if (dr->attached_dev_type == 0)
1594 			memset(attached_sas_addr, 0, 8);
1595 	}
1596 	kfree(disc_resp);
1597 	return res;
1598 }
1599 
1600 static int sas_find_bcast_phy(struct domain_device *dev, int *phy_id,
1601 			      int from_phy)
1602 {
1603 	struct expander_device *ex = &dev->ex_dev;
1604 	int res = 0;
1605 	int i;
1606 
1607 	for (i = from_phy; i < ex->num_phys; i++) {
1608 		int phy_change_count = 0;
1609 
1610 		res = sas_get_phy_change_count(dev, i, &phy_change_count);
1611 		if (res)
1612 			goto out;
1613 		else if (phy_change_count != ex->ex_phy[i].phy_change_count) {
1614 			ex->ex_phy[i].phy_change_count = phy_change_count;
1615 			*phy_id = i;
1616 			return 0;
1617 		}
1618 	}
1619 out:
1620 	return res;
1621 }
1622 
1623 static int sas_get_ex_change_count(struct domain_device *dev, int *ecc)
1624 {
1625 	int res;
1626 	u8  *rg_req;
1627 	struct smp_resp  *rg_resp;
1628 
1629 	rg_req = alloc_smp_req(RG_REQ_SIZE);
1630 	if (!rg_req)
1631 		return -ENOMEM;
1632 
1633 	rg_resp = alloc_smp_resp(RG_RESP_SIZE);
1634 	if (!rg_resp) {
1635 		kfree(rg_req);
1636 		return -ENOMEM;
1637 	}
1638 
1639 	rg_req[1] = SMP_REPORT_GENERAL;
1640 
1641 	res = smp_execute_task(dev, rg_req, RG_REQ_SIZE, rg_resp,
1642 			       RG_RESP_SIZE);
1643 	if (res)
1644 		goto out;
1645 	if (rg_resp->result != SMP_RESP_FUNC_ACC) {
1646 		res = rg_resp->result;
1647 		goto out;
1648 	}
1649 
1650 	*ecc = be16_to_cpu(rg_resp->rg.change_count);
1651 out:
1652 	kfree(rg_resp);
1653 	kfree(rg_req);
1654 	return res;
1655 }
1656 
1657 static int sas_find_bcast_dev(struct domain_device *dev,
1658 			      struct domain_device **src_dev)
1659 {
1660 	struct expander_device *ex = &dev->ex_dev;
1661 	int ex_change_count = -1;
1662 	int res;
1663 
1664 	res = sas_get_ex_change_count(dev, &ex_change_count);
1665 	if (res)
1666 		goto out;
1667 	if (ex_change_count != -1 &&
1668 	    ex_change_count != ex->ex_change_count) {
1669 		*src_dev = dev;
1670 		ex->ex_change_count = ex_change_count;
1671 	} else {
1672 		struct domain_device *ch;
1673 
1674 		list_for_each_entry(ch, &ex->children, siblings) {
1675 			if (ch->dev_type == EDGE_DEV ||
1676 			    ch->dev_type == FANOUT_DEV) {
1677 				res = sas_find_bcast_dev(ch, src_dev);
1678 				if (src_dev)
1679 					return res;
1680 			}
1681 		}
1682 	}
1683 out:
1684 	return res;
1685 }
1686 
1687 static void sas_unregister_ex_tree(struct domain_device *dev)
1688 {
1689 	struct expander_device *ex = &dev->ex_dev;
1690 	struct domain_device *child, *n;
1691 
1692 	list_for_each_entry_safe(child, n, &ex->children, siblings) {
1693 		if (child->dev_type == EDGE_DEV ||
1694 		    child->dev_type == FANOUT_DEV)
1695 			sas_unregister_ex_tree(child);
1696 		else
1697 			sas_unregister_dev(child);
1698 	}
1699 	sas_unregister_dev(dev);
1700 }
1701 
1702 static void sas_unregister_devs_sas_addr(struct domain_device *parent,
1703 					 int phy_id)
1704 {
1705 	struct expander_device *ex_dev = &parent->ex_dev;
1706 	struct ex_phy *phy = &ex_dev->ex_phy[phy_id];
1707 	struct domain_device *child, *n;
1708 
1709 	list_for_each_entry_safe(child, n, &ex_dev->children, siblings) {
1710 		if (SAS_ADDR(child->sas_addr) ==
1711 		    SAS_ADDR(phy->attached_sas_addr)) {
1712 			if (child->dev_type == EDGE_DEV ||
1713 			    child->dev_type == FANOUT_DEV)
1714 				sas_unregister_ex_tree(child);
1715 			else
1716 				sas_unregister_dev(child);
1717 			break;
1718 		}
1719 	}
1720 	sas_disable_routing(parent, phy->attached_sas_addr);
1721 	memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
1722 	sas_port_delete_phy(phy->port, phy->phy);
1723 	if (phy->port->num_phys == 0)
1724 		sas_port_delete(phy->port);
1725 	phy->port = NULL;
1726 }
1727 
1728 static int sas_discover_bfs_by_root_level(struct domain_device *root,
1729 					  const int level)
1730 {
1731 	struct expander_device *ex_root = &root->ex_dev;
1732 	struct domain_device *child;
1733 	int res = 0;
1734 
1735 	list_for_each_entry(child, &ex_root->children, siblings) {
1736 		if (child->dev_type == EDGE_DEV ||
1737 		    child->dev_type == FANOUT_DEV) {
1738 			struct sas_expander_device *ex =
1739 				rphy_to_expander_device(child->rphy);
1740 
1741 			if (level > ex->level)
1742 				res = sas_discover_bfs_by_root_level(child,
1743 								     level);
1744 			else if (level == ex->level)
1745 				res = sas_ex_discover_devices(child, -1);
1746 		}
1747 	}
1748 	return res;
1749 }
1750 
1751 static int sas_discover_bfs_by_root(struct domain_device *dev)
1752 {
1753 	int res;
1754 	struct sas_expander_device *ex = rphy_to_expander_device(dev->rphy);
1755 	int level = ex->level+1;
1756 
1757 	res = sas_ex_discover_devices(dev, -1);
1758 	if (res)
1759 		goto out;
1760 	do {
1761 		res = sas_discover_bfs_by_root_level(dev, level);
1762 		mb();
1763 		level += 1;
1764 	} while (level <= dev->port->disc.max_level);
1765 out:
1766 	return res;
1767 }
1768 
1769 static int sas_discover_new(struct domain_device *dev, int phy_id)
1770 {
1771 	struct ex_phy *ex_phy = &dev->ex_dev.ex_phy[phy_id];
1772 	struct domain_device *child;
1773 	int res;
1774 
1775 	SAS_DPRINTK("ex %016llx phy%d new device attached\n",
1776 		    SAS_ADDR(dev->sas_addr), phy_id);
1777 	res = sas_ex_phy_discover(dev, phy_id);
1778 	if (res)
1779 		goto out;
1780 	res = sas_ex_discover_devices(dev, phy_id);
1781 	if (res)
1782 		goto out;
1783 	list_for_each_entry(child, &dev->ex_dev.children, siblings) {
1784 		if (SAS_ADDR(child->sas_addr) ==
1785 		    SAS_ADDR(ex_phy->attached_sas_addr)) {
1786 			if (child->dev_type == EDGE_DEV ||
1787 			    child->dev_type == FANOUT_DEV)
1788 				res = sas_discover_bfs_by_root(child);
1789 			break;
1790 		}
1791 	}
1792 out:
1793 	return res;
1794 }
1795 
1796 static int sas_rediscover_dev(struct domain_device *dev, int phy_id)
1797 {
1798 	struct expander_device *ex = &dev->ex_dev;
1799 	struct ex_phy *phy = &ex->ex_phy[phy_id];
1800 	u8 attached_sas_addr[8];
1801 	int res;
1802 
1803 	res = sas_get_phy_attached_sas_addr(dev, phy_id, attached_sas_addr);
1804 	switch (res) {
1805 	case SMP_RESP_NO_PHY:
1806 		phy->phy_state = PHY_NOT_PRESENT;
1807 		sas_unregister_devs_sas_addr(dev, phy_id);
1808 		goto out; break;
1809 	case SMP_RESP_PHY_VACANT:
1810 		phy->phy_state = PHY_VACANT;
1811 		sas_unregister_devs_sas_addr(dev, phy_id);
1812 		goto out; break;
1813 	case SMP_RESP_FUNC_ACC:
1814 		break;
1815 	}
1816 
1817 	if (SAS_ADDR(attached_sas_addr) == 0) {
1818 		phy->phy_state = PHY_EMPTY;
1819 		sas_unregister_devs_sas_addr(dev, phy_id);
1820 	} else if (SAS_ADDR(attached_sas_addr) ==
1821 		   SAS_ADDR(phy->attached_sas_addr)) {
1822 		SAS_DPRINTK("ex %016llx phy 0x%x broadcast flutter\n",
1823 			    SAS_ADDR(dev->sas_addr), phy_id);
1824 		sas_ex_phy_discover(dev, phy_id);
1825 	} else
1826 		res = sas_discover_new(dev, phy_id);
1827 out:
1828 	return res;
1829 }
1830 
1831 static int sas_rediscover(struct domain_device *dev, const int phy_id)
1832 {
1833 	struct expander_device *ex = &dev->ex_dev;
1834 	struct ex_phy *changed_phy = &ex->ex_phy[phy_id];
1835 	int res = 0;
1836 	int i;
1837 
1838 	SAS_DPRINTK("ex %016llx phy%d originated BROADCAST(CHANGE)\n",
1839 		    SAS_ADDR(dev->sas_addr), phy_id);
1840 
1841 	if (SAS_ADDR(changed_phy->attached_sas_addr) != 0) {
1842 		for (i = 0; i < ex->num_phys; i++) {
1843 			struct ex_phy *phy = &ex->ex_phy[i];
1844 
1845 			if (i == phy_id)
1846 				continue;
1847 			if (SAS_ADDR(phy->attached_sas_addr) ==
1848 			    SAS_ADDR(changed_phy->attached_sas_addr)) {
1849 				SAS_DPRINTK("phy%d part of wide port with "
1850 					    "phy%d\n", phy_id, i);
1851 				goto out;
1852 			}
1853 		}
1854 		res = sas_rediscover_dev(dev, phy_id);
1855 	} else
1856 		res = sas_discover_new(dev, phy_id);
1857 out:
1858 	return res;
1859 }
1860 
1861 /**
1862  * sas_revalidate_domain -- revalidate the domain
1863  * @port: port to the domain of interest
1864  *
1865  * NOTE: this process _must_ quit (return) as soon as any connection
1866  * errors are encountered.  Connection recovery is done elsewhere.
1867  * Discover process only interrogates devices in order to discover the
1868  * domain.
1869  */
1870 int sas_ex_revalidate_domain(struct domain_device *port_dev)
1871 {
1872 	int res;
1873 	struct domain_device *dev = NULL;
1874 
1875 	res = sas_find_bcast_dev(port_dev, &dev);
1876 	if (res)
1877 		goto out;
1878 	if (dev) {
1879 		struct expander_device *ex = &dev->ex_dev;
1880 		int i = 0, phy_id;
1881 
1882 		do {
1883 			phy_id = -1;
1884 			res = sas_find_bcast_phy(dev, &phy_id, i);
1885 			if (phy_id == -1)
1886 				break;
1887 			res = sas_rediscover(dev, phy_id);
1888 			i = phy_id + 1;
1889 		} while (i < ex->num_phys);
1890 	}
1891 out:
1892 	return res;
1893 }
1894 
1895 int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
1896 		    struct request *req)
1897 {
1898 	struct domain_device *dev;
1899 	int ret, type;
1900 	struct request *rsp = req->next_rq;
1901 
1902 	if (!rsp) {
1903 		printk("%s: space for a smp response is missing\n",
1904 		       __func__);
1905 		return -EINVAL;
1906 	}
1907 
1908 	/* no rphy means no smp target support (ie aic94xx host) */
1909 	if (!rphy)
1910 		return sas_smp_host_handler(shost, req, rsp);
1911 
1912 	type = rphy->identify.device_type;
1913 
1914 	if (type != SAS_EDGE_EXPANDER_DEVICE &&
1915 	    type != SAS_FANOUT_EXPANDER_DEVICE) {
1916 		printk("%s: can we send a smp request to a device?\n",
1917 		       __func__);
1918 		return -EINVAL;
1919 	}
1920 
1921 	dev = sas_find_dev_by_rphy(rphy);
1922 	if (!dev) {
1923 		printk("%s: fail to find a domain_device?\n", __func__);
1924 		return -EINVAL;
1925 	}
1926 
1927 	/* do we need to support multiple segments? */
1928 	if (req->bio->bi_vcnt > 1 || rsp->bio->bi_vcnt > 1) {
1929 		printk("%s: multiple segments req %u %u, rsp %u %u\n",
1930 		       __func__, req->bio->bi_vcnt, blk_rq_bytes(req),
1931 		       rsp->bio->bi_vcnt, blk_rq_bytes(rsp));
1932 		return -EINVAL;
1933 	}
1934 
1935 	ret = smp_execute_task(dev, bio_data(req->bio), blk_rq_bytes(req),
1936 			       bio_data(rsp->bio), blk_rq_bytes(rsp));
1937 	if (ret > 0) {
1938 		/* positive number is the untransferred residual */
1939 		rsp->resid_len = ret;
1940 		req->resid_len = 0;
1941 		ret = 0;
1942 	} else if (ret == 0) {
1943 		rsp->resid_len = 0;
1944 		req->resid_len = 0;
1945 	}
1946 
1947 	return ret;
1948 }
1949