1 /*
2  * This file is provided under a dual BSD/GPLv2 license.  When using or
3  * redistributing this file, you may do so under either license.
4  *
5  * GPL LICENSE SUMMARY
6  *
7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21  * The full GNU General Public License is included in this distribution
22  * in the file called LICENSE.GPL.
23  *
24  * BSD LICENSE
25  *
26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
27  * All rights reserved.
28  *
29  * Redistribution and use in source and binary forms, with or without
30  * modification, are permitted provided that the following conditions
31  * are met:
32  *
33  *   * Redistributions of source code must retain the above copyright
34  *     notice, this list of conditions and the following disclaimer.
35  *   * Redistributions in binary form must reproduce the above copyright
36  *     notice, this list of conditions and the following disclaimer in
37  *     the documentation and/or other materials provided with the
38  *     distribution.
39  *   * Neither the name of Intel Corporation nor the names of its
40  *     contributors may be used to endorse or promote products derived
41  *     from this software without specific prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54  */
55 #include <scsi/sas.h>
56 #include "isci.h"
57 #include "port.h"
58 #include "remote_device.h"
59 #include "request.h"
60 #include "remote_node_context.h"
61 #include "scu_event_codes.h"
62 #include "task.h"
63 
64 /**
65  * isci_remote_device_not_ready() - This function is called by the ihost when
66  *    the remote device is not ready. We mark the isci device as ready (not
67  *    "ready_for_io") and signal the waiting proccess.
68  * @isci_host: This parameter specifies the isci host object.
69  * @isci_device: This parameter specifies the remote device
70  *
71  * sci_lock is held on entrance to this function.
72  */
73 static void isci_remote_device_not_ready(struct isci_host *ihost,
74 				  struct isci_remote_device *idev, u32 reason)
75 {
76 	struct isci_request *ireq;
77 
78 	dev_dbg(&ihost->pdev->dev,
79 		"%s: isci_device = %p\n", __func__, idev);
80 
81 	switch (reason) {
82 	case SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED:
83 		set_bit(IDEV_GONE, &idev->flags);
84 		break;
85 	case SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED:
86 		set_bit(IDEV_IO_NCQERROR, &idev->flags);
87 
88 		/* Kill all outstanding requests for the device. */
89 		list_for_each_entry(ireq, &idev->reqs_in_process, dev_node) {
90 
91 			dev_dbg(&ihost->pdev->dev,
92 				"%s: isci_device = %p request = %p\n",
93 				__func__, idev, ireq);
94 
95 			sci_controller_terminate_request(ihost,
96 							  idev,
97 							  ireq);
98 		}
99 		/* Fall through into the default case... */
100 	default:
101 		clear_bit(IDEV_IO_READY, &idev->flags);
102 		break;
103 	}
104 }
105 
106 /**
107  * isci_remote_device_ready() - This function is called by the ihost when the
108  *    remote device is ready. We mark the isci device as ready and signal the
109  *    waiting proccess.
110  * @ihost: our valid isci_host
111  * @idev: remote device
112  *
113  */
114 static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote_device *idev)
115 {
116 	dev_dbg(&ihost->pdev->dev,
117 		"%s: idev = %p\n", __func__, idev);
118 
119 	clear_bit(IDEV_IO_NCQERROR, &idev->flags);
120 	set_bit(IDEV_IO_READY, &idev->flags);
121 	if (test_and_clear_bit(IDEV_START_PENDING, &idev->flags))
122 		wake_up(&ihost->eventq);
123 }
124 
125 /* called once the remote node context is ready to be freed.
126  * The remote device can now report that its stop operation is complete. none
127  */
128 static void rnc_destruct_done(void *_dev)
129 {
130 	struct isci_remote_device *idev = _dev;
131 
132 	BUG_ON(idev->started_request_count != 0);
133 	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
134 }
135 
136 static enum sci_status sci_remote_device_terminate_requests(struct isci_remote_device *idev)
137 {
138 	struct isci_host *ihost = idev->owning_port->owning_controller;
139 	enum sci_status status  = SCI_SUCCESS;
140 	u32 i;
141 
142 	for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
143 		struct isci_request *ireq = ihost->reqs[i];
144 		enum sci_status s;
145 
146 		if (!test_bit(IREQ_ACTIVE, &ireq->flags) ||
147 		    ireq->target_device != idev)
148 			continue;
149 
150 		s = sci_controller_terminate_request(ihost, idev, ireq);
151 		if (s != SCI_SUCCESS)
152 			status = s;
153 	}
154 
155 	return status;
156 }
157 
158 enum sci_status sci_remote_device_stop(struct isci_remote_device *idev,
159 					u32 timeout)
160 {
161 	struct sci_base_state_machine *sm = &idev->sm;
162 	enum sci_remote_device_states state = sm->current_state_id;
163 
164 	switch (state) {
165 	case SCI_DEV_INITIAL:
166 	case SCI_DEV_FAILED:
167 	case SCI_DEV_FINAL:
168 	default:
169 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
170 			 __func__, state);
171 		return SCI_FAILURE_INVALID_STATE;
172 	case SCI_DEV_STOPPED:
173 		return SCI_SUCCESS;
174 	case SCI_DEV_STARTING:
175 		/* device not started so there had better be no requests */
176 		BUG_ON(idev->started_request_count != 0);
177 		sci_remote_node_context_destruct(&idev->rnc,
178 						      rnc_destruct_done, idev);
179 		/* Transition to the stopping state and wait for the
180 		 * remote node to complete being posted and invalidated.
181 		 */
182 		sci_change_state(sm, SCI_DEV_STOPPING);
183 		return SCI_SUCCESS;
184 	case SCI_DEV_READY:
185 	case SCI_STP_DEV_IDLE:
186 	case SCI_STP_DEV_CMD:
187 	case SCI_STP_DEV_NCQ:
188 	case SCI_STP_DEV_NCQ_ERROR:
189 	case SCI_STP_DEV_AWAIT_RESET:
190 	case SCI_SMP_DEV_IDLE:
191 	case SCI_SMP_DEV_CMD:
192 		sci_change_state(sm, SCI_DEV_STOPPING);
193 		if (idev->started_request_count == 0) {
194 			sci_remote_node_context_destruct(&idev->rnc,
195 							      rnc_destruct_done, idev);
196 			return SCI_SUCCESS;
197 		} else
198 			return sci_remote_device_terminate_requests(idev);
199 		break;
200 	case SCI_DEV_STOPPING:
201 		/* All requests should have been terminated, but if there is an
202 		 * attempt to stop a device already in the stopping state, then
203 		 * try again to terminate.
204 		 */
205 		return sci_remote_device_terminate_requests(idev);
206 	case SCI_DEV_RESETTING:
207 		sci_change_state(sm, SCI_DEV_STOPPING);
208 		return SCI_SUCCESS;
209 	}
210 }
211 
212 enum sci_status sci_remote_device_reset(struct isci_remote_device *idev)
213 {
214 	struct sci_base_state_machine *sm = &idev->sm;
215 	enum sci_remote_device_states state = sm->current_state_id;
216 
217 	switch (state) {
218 	case SCI_DEV_INITIAL:
219 	case SCI_DEV_STOPPED:
220 	case SCI_DEV_STARTING:
221 	case SCI_SMP_DEV_IDLE:
222 	case SCI_SMP_DEV_CMD:
223 	case SCI_DEV_STOPPING:
224 	case SCI_DEV_FAILED:
225 	case SCI_DEV_RESETTING:
226 	case SCI_DEV_FINAL:
227 	default:
228 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
229 			 __func__, state);
230 		return SCI_FAILURE_INVALID_STATE;
231 	case SCI_DEV_READY:
232 	case SCI_STP_DEV_IDLE:
233 	case SCI_STP_DEV_CMD:
234 	case SCI_STP_DEV_NCQ:
235 	case SCI_STP_DEV_NCQ_ERROR:
236 	case SCI_STP_DEV_AWAIT_RESET:
237 		sci_change_state(sm, SCI_DEV_RESETTING);
238 		return SCI_SUCCESS;
239 	}
240 }
241 
242 enum sci_status sci_remote_device_reset_complete(struct isci_remote_device *idev)
243 {
244 	struct sci_base_state_machine *sm = &idev->sm;
245 	enum sci_remote_device_states state = sm->current_state_id;
246 
247 	if (state != SCI_DEV_RESETTING) {
248 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
249 			 __func__, state);
250 		return SCI_FAILURE_INVALID_STATE;
251 	}
252 
253 	sci_change_state(sm, SCI_DEV_READY);
254 	return SCI_SUCCESS;
255 }
256 
257 enum sci_status sci_remote_device_suspend(struct isci_remote_device *idev,
258 					       u32 suspend_type)
259 {
260 	struct sci_base_state_machine *sm = &idev->sm;
261 	enum sci_remote_device_states state = sm->current_state_id;
262 
263 	if (state != SCI_STP_DEV_CMD) {
264 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
265 			 __func__, state);
266 		return SCI_FAILURE_INVALID_STATE;
267 	}
268 
269 	return sci_remote_node_context_suspend(&idev->rnc,
270 						    suspend_type, NULL, NULL);
271 }
272 
273 enum sci_status sci_remote_device_frame_handler(struct isci_remote_device *idev,
274 						     u32 frame_index)
275 {
276 	struct sci_base_state_machine *sm = &idev->sm;
277 	enum sci_remote_device_states state = sm->current_state_id;
278 	struct isci_host *ihost = idev->owning_port->owning_controller;
279 	enum sci_status status;
280 
281 	switch (state) {
282 	case SCI_DEV_INITIAL:
283 	case SCI_DEV_STOPPED:
284 	case SCI_DEV_STARTING:
285 	case SCI_STP_DEV_IDLE:
286 	case SCI_SMP_DEV_IDLE:
287 	case SCI_DEV_FINAL:
288 	default:
289 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
290 			 __func__, state);
291 		/* Return the frame back to the controller */
292 		sci_controller_release_frame(ihost, frame_index);
293 		return SCI_FAILURE_INVALID_STATE;
294 	case SCI_DEV_READY:
295 	case SCI_STP_DEV_NCQ_ERROR:
296 	case SCI_STP_DEV_AWAIT_RESET:
297 	case SCI_DEV_STOPPING:
298 	case SCI_DEV_FAILED:
299 	case SCI_DEV_RESETTING: {
300 		struct isci_request *ireq;
301 		struct ssp_frame_hdr hdr;
302 		void *frame_header;
303 		ssize_t word_cnt;
304 
305 		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
306 								       frame_index,
307 								       &frame_header);
308 		if (status != SCI_SUCCESS)
309 			return status;
310 
311 		word_cnt = sizeof(hdr) / sizeof(u32);
312 		sci_swab32_cpy(&hdr, frame_header, word_cnt);
313 
314 		ireq = sci_request_by_tag(ihost, be16_to_cpu(hdr.tag));
315 		if (ireq && ireq->target_device == idev) {
316 			/* The IO request is now in charge of releasing the frame */
317 			status = sci_io_request_frame_handler(ireq, frame_index);
318 		} else {
319 			/* We could not map this tag to a valid IO
320 			 * request Just toss the frame and continue
321 			 */
322 			sci_controller_release_frame(ihost, frame_index);
323 		}
324 		break;
325 	}
326 	case SCI_STP_DEV_NCQ: {
327 		struct dev_to_host_fis *hdr;
328 
329 		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
330 								       frame_index,
331 								       (void **)&hdr);
332 		if (status != SCI_SUCCESS)
333 			return status;
334 
335 		if (hdr->fis_type == FIS_SETDEVBITS &&
336 		    (hdr->status & ATA_ERR)) {
337 			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
338 
339 			/* TODO Check sactive and complete associated IO if any. */
340 			sci_change_state(sm, SCI_STP_DEV_NCQ_ERROR);
341 		} else if (hdr->fis_type == FIS_REGD2H &&
342 			   (hdr->status & ATA_ERR)) {
343 			/*
344 			 * Some devices return D2H FIS when an NCQ error is detected.
345 			 * Treat this like an SDB error FIS ready reason.
346 			 */
347 			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
348 			sci_change_state(&idev->sm, SCI_STP_DEV_NCQ_ERROR);
349 		} else
350 			status = SCI_FAILURE;
351 
352 		sci_controller_release_frame(ihost, frame_index);
353 		break;
354 	}
355 	case SCI_STP_DEV_CMD:
356 	case SCI_SMP_DEV_CMD:
357 		/* The device does not process any UF received from the hardware while
358 		 * in this state.  All unsolicited frames are forwarded to the io request
359 		 * object.
360 		 */
361 		status = sci_io_request_frame_handler(idev->working_request, frame_index);
362 		break;
363 	}
364 
365 	return status;
366 }
367 
368 static bool is_remote_device_ready(struct isci_remote_device *idev)
369 {
370 
371 	struct sci_base_state_machine *sm = &idev->sm;
372 	enum sci_remote_device_states state = sm->current_state_id;
373 
374 	switch (state) {
375 	case SCI_DEV_READY:
376 	case SCI_STP_DEV_IDLE:
377 	case SCI_STP_DEV_CMD:
378 	case SCI_STP_DEV_NCQ:
379 	case SCI_STP_DEV_NCQ_ERROR:
380 	case SCI_STP_DEV_AWAIT_RESET:
381 	case SCI_SMP_DEV_IDLE:
382 	case SCI_SMP_DEV_CMD:
383 		return true;
384 	default:
385 		return false;
386 	}
387 }
388 
389 enum sci_status sci_remote_device_event_handler(struct isci_remote_device *idev,
390 						     u32 event_code)
391 {
392 	struct sci_base_state_machine *sm = &idev->sm;
393 	enum sci_remote_device_states state = sm->current_state_id;
394 	enum sci_status status;
395 
396 	switch (scu_get_event_type(event_code)) {
397 	case SCU_EVENT_TYPE_RNC_OPS_MISC:
398 	case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
399 	case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
400 		status = sci_remote_node_context_event_handler(&idev->rnc, event_code);
401 		break;
402 	case SCU_EVENT_TYPE_PTX_SCHEDULE_EVENT:
403 		if (scu_get_event_code(event_code) == SCU_EVENT_IT_NEXUS_TIMEOUT) {
404 			status = SCI_SUCCESS;
405 
406 			/* Suspend the associated RNC */
407 			sci_remote_node_context_suspend(&idev->rnc,
408 							      SCI_SOFTWARE_SUSPENSION,
409 							      NULL, NULL);
410 
411 			dev_dbg(scirdev_to_dev(idev),
412 				"%s: device: %p event code: %x: %s\n",
413 				__func__, idev, event_code,
414 				is_remote_device_ready(idev)
415 				? "I_T_Nexus_Timeout event"
416 				: "I_T_Nexus_Timeout event in wrong state");
417 
418 			break;
419 		}
420 	/* Else, fall through and treat as unhandled... */
421 	default:
422 		dev_dbg(scirdev_to_dev(idev),
423 			"%s: device: %p event code: %x: %s\n",
424 			__func__, idev, event_code,
425 			is_remote_device_ready(idev)
426 			? "unexpected event"
427 			: "unexpected event in wrong state");
428 		status = SCI_FAILURE_INVALID_STATE;
429 		break;
430 	}
431 
432 	if (status != SCI_SUCCESS)
433 		return status;
434 
435 	if (state == SCI_STP_DEV_IDLE) {
436 
437 		/* We pick up suspension events to handle specifically to this
438 		 * state. We resume the RNC right away.
439 		 */
440 		if (scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX ||
441 		    scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX)
442 			status = sci_remote_node_context_resume(&idev->rnc, NULL, NULL);
443 	}
444 
445 	return status;
446 }
447 
448 static void sci_remote_device_start_request(struct isci_remote_device *idev,
449 						 struct isci_request *ireq,
450 						 enum sci_status status)
451 {
452 	struct isci_port *iport = idev->owning_port;
453 
454 	/* cleanup requests that failed after starting on the port */
455 	if (status != SCI_SUCCESS)
456 		sci_port_complete_io(iport, idev, ireq);
457 	else {
458 		kref_get(&idev->kref);
459 		idev->started_request_count++;
460 	}
461 }
462 
463 enum sci_status sci_remote_device_start_io(struct isci_host *ihost,
464 						struct isci_remote_device *idev,
465 						struct isci_request *ireq)
466 {
467 	struct sci_base_state_machine *sm = &idev->sm;
468 	enum sci_remote_device_states state = sm->current_state_id;
469 	struct isci_port *iport = idev->owning_port;
470 	enum sci_status status;
471 
472 	switch (state) {
473 	case SCI_DEV_INITIAL:
474 	case SCI_DEV_STOPPED:
475 	case SCI_DEV_STARTING:
476 	case SCI_STP_DEV_NCQ_ERROR:
477 	case SCI_DEV_STOPPING:
478 	case SCI_DEV_FAILED:
479 	case SCI_DEV_RESETTING:
480 	case SCI_DEV_FINAL:
481 	default:
482 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
483 			 __func__, state);
484 		return SCI_FAILURE_INVALID_STATE;
485 	case SCI_DEV_READY:
486 		/* attempt to start an io request for this device object. The remote
487 		 * device object will issue the start request for the io and if
488 		 * successful it will start the request for the port object then
489 		 * increment its own request count.
490 		 */
491 		status = sci_port_start_io(iport, idev, ireq);
492 		if (status != SCI_SUCCESS)
493 			return status;
494 
495 		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
496 		if (status != SCI_SUCCESS)
497 			break;
498 
499 		status = sci_request_start(ireq);
500 		break;
501 	case SCI_STP_DEV_IDLE: {
502 		/* handle the start io operation for a sata device that is in
503 		 * the command idle state. - Evalute the type of IO request to
504 		 * be started - If its an NCQ request change to NCQ substate -
505 		 * If its any other command change to the CMD substate
506 		 *
507 		 * If this is a softreset we may want to have a different
508 		 * substate.
509 		 */
510 		enum sci_remote_device_states new_state;
511 		struct sas_task *task = isci_request_access_task(ireq);
512 
513 		status = sci_port_start_io(iport, idev, ireq);
514 		if (status != SCI_SUCCESS)
515 			return status;
516 
517 		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
518 		if (status != SCI_SUCCESS)
519 			break;
520 
521 		status = sci_request_start(ireq);
522 		if (status != SCI_SUCCESS)
523 			break;
524 
525 		if (task->ata_task.use_ncq)
526 			new_state = SCI_STP_DEV_NCQ;
527 		else {
528 			idev->working_request = ireq;
529 			new_state = SCI_STP_DEV_CMD;
530 		}
531 		sci_change_state(sm, new_state);
532 		break;
533 	}
534 	case SCI_STP_DEV_NCQ: {
535 		struct sas_task *task = isci_request_access_task(ireq);
536 
537 		if (task->ata_task.use_ncq) {
538 			status = sci_port_start_io(iport, idev, ireq);
539 			if (status != SCI_SUCCESS)
540 				return status;
541 
542 			status = sci_remote_node_context_start_io(&idev->rnc, ireq);
543 			if (status != SCI_SUCCESS)
544 				break;
545 
546 			status = sci_request_start(ireq);
547 		} else
548 			return SCI_FAILURE_INVALID_STATE;
549 		break;
550 	}
551 	case SCI_STP_DEV_AWAIT_RESET:
552 		return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
553 	case SCI_SMP_DEV_IDLE:
554 		status = sci_port_start_io(iport, idev, ireq);
555 		if (status != SCI_SUCCESS)
556 			return status;
557 
558 		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
559 		if (status != SCI_SUCCESS)
560 			break;
561 
562 		status = sci_request_start(ireq);
563 		if (status != SCI_SUCCESS)
564 			break;
565 
566 		idev->working_request = ireq;
567 		sci_change_state(&idev->sm, SCI_SMP_DEV_CMD);
568 		break;
569 	case SCI_STP_DEV_CMD:
570 	case SCI_SMP_DEV_CMD:
571 		/* device is already handling a command it can not accept new commands
572 		 * until this one is complete.
573 		 */
574 		return SCI_FAILURE_INVALID_STATE;
575 	}
576 
577 	sci_remote_device_start_request(idev, ireq, status);
578 	return status;
579 }
580 
581 static enum sci_status common_complete_io(struct isci_port *iport,
582 					  struct isci_remote_device *idev,
583 					  struct isci_request *ireq)
584 {
585 	enum sci_status status;
586 
587 	status = sci_request_complete(ireq);
588 	if (status != SCI_SUCCESS)
589 		return status;
590 
591 	status = sci_port_complete_io(iport, idev, ireq);
592 	if (status != SCI_SUCCESS)
593 		return status;
594 
595 	sci_remote_device_decrement_request_count(idev);
596 	return status;
597 }
598 
599 enum sci_status sci_remote_device_complete_io(struct isci_host *ihost,
600 						   struct isci_remote_device *idev,
601 						   struct isci_request *ireq)
602 {
603 	struct sci_base_state_machine *sm = &idev->sm;
604 	enum sci_remote_device_states state = sm->current_state_id;
605 	struct isci_port *iport = idev->owning_port;
606 	enum sci_status status;
607 
608 	switch (state) {
609 	case SCI_DEV_INITIAL:
610 	case SCI_DEV_STOPPED:
611 	case SCI_DEV_STARTING:
612 	case SCI_STP_DEV_IDLE:
613 	case SCI_SMP_DEV_IDLE:
614 	case SCI_DEV_FAILED:
615 	case SCI_DEV_FINAL:
616 	default:
617 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
618 			 __func__, state);
619 		return SCI_FAILURE_INVALID_STATE;
620 	case SCI_DEV_READY:
621 	case SCI_STP_DEV_AWAIT_RESET:
622 	case SCI_DEV_RESETTING:
623 		status = common_complete_io(iport, idev, ireq);
624 		break;
625 	case SCI_STP_DEV_CMD:
626 	case SCI_STP_DEV_NCQ:
627 	case SCI_STP_DEV_NCQ_ERROR:
628 		status = common_complete_io(iport, idev, ireq);
629 		if (status != SCI_SUCCESS)
630 			break;
631 
632 		if (ireq->sci_status == SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
633 			/* This request causes hardware error, device needs to be Lun Reset.
634 			 * So here we force the state machine to IDLE state so the rest IOs
635 			 * can reach RNC state handler, these IOs will be completed by RNC with
636 			 * status of "DEVICE_RESET_REQUIRED", instead of "INVALID STATE".
637 			 */
638 			sci_change_state(sm, SCI_STP_DEV_AWAIT_RESET);
639 		} else if (idev->started_request_count == 0)
640 			sci_change_state(sm, SCI_STP_DEV_IDLE);
641 		break;
642 	case SCI_SMP_DEV_CMD:
643 		status = common_complete_io(iport, idev, ireq);
644 		if (status != SCI_SUCCESS)
645 			break;
646 		sci_change_state(sm, SCI_SMP_DEV_IDLE);
647 		break;
648 	case SCI_DEV_STOPPING:
649 		status = common_complete_io(iport, idev, ireq);
650 		if (status != SCI_SUCCESS)
651 			break;
652 
653 		if (idev->started_request_count == 0)
654 			sci_remote_node_context_destruct(&idev->rnc,
655 							 rnc_destruct_done,
656 							 idev);
657 		break;
658 	}
659 
660 	if (status != SCI_SUCCESS)
661 		dev_err(scirdev_to_dev(idev),
662 			"%s: Port:0x%p Device:0x%p Request:0x%p Status:0x%x "
663 			"could not complete\n", __func__, iport,
664 			idev, ireq, status);
665 	else
666 		isci_put_device(idev);
667 
668 	return status;
669 }
670 
671 static void sci_remote_device_continue_request(void *dev)
672 {
673 	struct isci_remote_device *idev = dev;
674 
675 	/* we need to check if this request is still valid to continue. */
676 	if (idev->working_request)
677 		sci_controller_continue_io(idev->working_request);
678 }
679 
680 enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
681 						  struct isci_remote_device *idev,
682 						  struct isci_request *ireq)
683 {
684 	struct sci_base_state_machine *sm = &idev->sm;
685 	enum sci_remote_device_states state = sm->current_state_id;
686 	struct isci_port *iport = idev->owning_port;
687 	enum sci_status status;
688 
689 	switch (state) {
690 	case SCI_DEV_INITIAL:
691 	case SCI_DEV_STOPPED:
692 	case SCI_DEV_STARTING:
693 	case SCI_SMP_DEV_IDLE:
694 	case SCI_SMP_DEV_CMD:
695 	case SCI_DEV_STOPPING:
696 	case SCI_DEV_FAILED:
697 	case SCI_DEV_RESETTING:
698 	case SCI_DEV_FINAL:
699 	default:
700 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
701 			 __func__, state);
702 		return SCI_FAILURE_INVALID_STATE;
703 	case SCI_STP_DEV_IDLE:
704 	case SCI_STP_DEV_CMD:
705 	case SCI_STP_DEV_NCQ:
706 	case SCI_STP_DEV_NCQ_ERROR:
707 	case SCI_STP_DEV_AWAIT_RESET:
708 		status = sci_port_start_io(iport, idev, ireq);
709 		if (status != SCI_SUCCESS)
710 			return status;
711 
712 		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
713 		if (status != SCI_SUCCESS)
714 			goto out;
715 
716 		status = sci_request_start(ireq);
717 		if (status != SCI_SUCCESS)
718 			goto out;
719 
720 		/* Note: If the remote device state is not IDLE this will
721 		 * replace the request that probably resulted in the task
722 		 * management request.
723 		 */
724 		idev->working_request = ireq;
725 		sci_change_state(sm, SCI_STP_DEV_CMD);
726 
727 		/* The remote node context must cleanup the TCi to NCQ mapping
728 		 * table.  The only way to do this correctly is to either write
729 		 * to the TLCR register or to invalidate and repost the RNC. In
730 		 * either case the remote node context state machine will take
731 		 * the correct action when the remote node context is suspended
732 		 * and later resumed.
733 		 */
734 		sci_remote_node_context_suspend(&idev->rnc,
735 				SCI_SOFTWARE_SUSPENSION, NULL, NULL);
736 		sci_remote_node_context_resume(&idev->rnc,
737 				sci_remote_device_continue_request,
738 						    idev);
739 
740 	out:
741 		sci_remote_device_start_request(idev, ireq, status);
742 		/* We need to let the controller start request handler know that
743 		 * it can't post TC yet. We will provide a callback function to
744 		 * post TC when RNC gets resumed.
745 		 */
746 		return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
747 	case SCI_DEV_READY:
748 		status = sci_port_start_io(iport, idev, ireq);
749 		if (status != SCI_SUCCESS)
750 			return status;
751 
752 		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
753 		if (status != SCI_SUCCESS)
754 			break;
755 
756 		status = sci_request_start(ireq);
757 		break;
758 	}
759 	sci_remote_device_start_request(idev, ireq, status);
760 
761 	return status;
762 }
763 
764 void sci_remote_device_post_request(struct isci_remote_device *idev, u32 request)
765 {
766 	struct isci_port *iport = idev->owning_port;
767 	u32 context;
768 
769 	context = request |
770 		  (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
771 		  (iport->physical_port_index << SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
772 		  idev->rnc.remote_node_index;
773 
774 	sci_controller_post_request(iport->owning_controller, context);
775 }
776 
777 /* called once the remote node context has transisitioned to a
778  * ready state.  This is the indication that the remote device object can also
779  * transition to ready.
780  */
781 static void remote_device_resume_done(void *_dev)
782 {
783 	struct isci_remote_device *idev = _dev;
784 
785 	if (is_remote_device_ready(idev))
786 		return;
787 
788 	/* go 'ready' if we are not already in a ready state */
789 	sci_change_state(&idev->sm, SCI_DEV_READY);
790 }
791 
792 static void sci_stp_remote_device_ready_idle_substate_resume_complete_handler(void *_dev)
793 {
794 	struct isci_remote_device *idev = _dev;
795 	struct isci_host *ihost = idev->owning_port->owning_controller;
796 
797 	/* For NCQ operation we do not issue a isci_remote_device_not_ready().
798 	 * As a result, avoid sending the ready notification.
799 	 */
800 	if (idev->sm.previous_state_id != SCI_STP_DEV_NCQ)
801 		isci_remote_device_ready(ihost, idev);
802 }
803 
804 static void sci_remote_device_initial_state_enter(struct sci_base_state_machine *sm)
805 {
806 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
807 
808 	/* Initial state is a transitional state to the stopped state */
809 	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
810 }
811 
812 /**
813  * sci_remote_device_destruct() - free remote node context and destruct
814  * @remote_device: This parameter specifies the remote device to be destructed.
815  *
816  * Remote device objects are a limited resource.  As such, they must be
817  * protected.  Thus calls to construct and destruct are mutually exclusive and
818  * non-reentrant. The return value shall indicate if the device was
819  * successfully destructed or if some failure occurred. enum sci_status This value
820  * is returned if the device is successfully destructed.
821  * SCI_FAILURE_INVALID_REMOTE_DEVICE This value is returned if the supplied
822  * device isn't valid (e.g. it's already been destoryed, the handle isn't
823  * valid, etc.).
824  */
825 static enum sci_status sci_remote_device_destruct(struct isci_remote_device *idev)
826 {
827 	struct sci_base_state_machine *sm = &idev->sm;
828 	enum sci_remote_device_states state = sm->current_state_id;
829 	struct isci_host *ihost;
830 
831 	if (state != SCI_DEV_STOPPED) {
832 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
833 			 __func__, state);
834 		return SCI_FAILURE_INVALID_STATE;
835 	}
836 
837 	ihost = idev->owning_port->owning_controller;
838 	sci_controller_free_remote_node_context(ihost, idev,
839 						     idev->rnc.remote_node_index);
840 	idev->rnc.remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
841 	sci_change_state(sm, SCI_DEV_FINAL);
842 
843 	return SCI_SUCCESS;
844 }
845 
846 /**
847  * isci_remote_device_deconstruct() - This function frees an isci_remote_device.
848  * @ihost: This parameter specifies the isci host object.
849  * @idev: This parameter specifies the remote device to be freed.
850  *
851  */
852 static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_remote_device *idev)
853 {
854 	dev_dbg(&ihost->pdev->dev,
855 		"%s: isci_device = %p\n", __func__, idev);
856 
857 	/* There should not be any outstanding io's. All paths to
858 	 * here should go through isci_remote_device_nuke_requests.
859 	 * If we hit this condition, we will need a way to complete
860 	 * io requests in process */
861 	BUG_ON(!list_empty(&idev->reqs_in_process));
862 
863 	sci_remote_device_destruct(idev);
864 	list_del_init(&idev->node);
865 	isci_put_device(idev);
866 }
867 
868 static void sci_remote_device_stopped_state_enter(struct sci_base_state_machine *sm)
869 {
870 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
871 	struct isci_host *ihost = idev->owning_port->owning_controller;
872 	u32 prev_state;
873 
874 	/* If we are entering from the stopping state let the SCI User know that
875 	 * the stop operation has completed.
876 	 */
877 	prev_state = idev->sm.previous_state_id;
878 	if (prev_state == SCI_DEV_STOPPING)
879 		isci_remote_device_deconstruct(ihost, idev);
880 
881 	sci_controller_remote_device_stopped(ihost, idev);
882 }
883 
884 static void sci_remote_device_starting_state_enter(struct sci_base_state_machine *sm)
885 {
886 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
887 	struct isci_host *ihost = idev->owning_port->owning_controller;
888 
889 	isci_remote_device_not_ready(ihost, idev,
890 				     SCIC_REMOTE_DEVICE_NOT_READY_START_REQUESTED);
891 }
892 
893 static void sci_remote_device_ready_state_enter(struct sci_base_state_machine *sm)
894 {
895 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
896 	struct isci_host *ihost = idev->owning_port->owning_controller;
897 	struct domain_device *dev = idev->domain_dev;
898 
899 	if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_SATA)) {
900 		sci_change_state(&idev->sm, SCI_STP_DEV_IDLE);
901 	} else if (dev_is_expander(dev)) {
902 		sci_change_state(&idev->sm, SCI_SMP_DEV_IDLE);
903 	} else
904 		isci_remote_device_ready(ihost, idev);
905 }
906 
907 static void sci_remote_device_ready_state_exit(struct sci_base_state_machine *sm)
908 {
909 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
910 	struct domain_device *dev = idev->domain_dev;
911 
912 	if (dev->dev_type == SAS_END_DEV) {
913 		struct isci_host *ihost = idev->owning_port->owning_controller;
914 
915 		isci_remote_device_not_ready(ihost, idev,
916 					     SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED);
917 	}
918 }
919 
920 static void sci_remote_device_resetting_state_enter(struct sci_base_state_machine *sm)
921 {
922 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
923 
924 	sci_remote_node_context_suspend(
925 		&idev->rnc, SCI_SOFTWARE_SUSPENSION, NULL, NULL);
926 }
927 
928 static void sci_remote_device_resetting_state_exit(struct sci_base_state_machine *sm)
929 {
930 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
931 
932 	sci_remote_node_context_resume(&idev->rnc, NULL, NULL);
933 }
934 
935 static void sci_stp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
936 {
937 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
938 
939 	idev->working_request = NULL;
940 	if (sci_remote_node_context_is_ready(&idev->rnc)) {
941 		/*
942 		 * Since the RNC is ready, it's alright to finish completion
943 		 * processing (e.g. signal the remote device is ready). */
944 		sci_stp_remote_device_ready_idle_substate_resume_complete_handler(idev);
945 	} else {
946 		sci_remote_node_context_resume(&idev->rnc,
947 			sci_stp_remote_device_ready_idle_substate_resume_complete_handler,
948 			idev);
949 	}
950 }
951 
952 static void sci_stp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
953 {
954 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
955 	struct isci_host *ihost = idev->owning_port->owning_controller;
956 
957 	BUG_ON(idev->working_request == NULL);
958 
959 	isci_remote_device_not_ready(ihost, idev,
960 				     SCIC_REMOTE_DEVICE_NOT_READY_SATA_REQUEST_STARTED);
961 }
962 
963 static void sci_stp_remote_device_ready_ncq_error_substate_enter(struct sci_base_state_machine *sm)
964 {
965 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
966 	struct isci_host *ihost = idev->owning_port->owning_controller;
967 
968 	if (idev->not_ready_reason == SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED)
969 		isci_remote_device_not_ready(ihost, idev,
970 					     idev->not_ready_reason);
971 }
972 
973 static void sci_smp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
974 {
975 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
976 	struct isci_host *ihost = idev->owning_port->owning_controller;
977 
978 	isci_remote_device_ready(ihost, idev);
979 }
980 
981 static void sci_smp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
982 {
983 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
984 	struct isci_host *ihost = idev->owning_port->owning_controller;
985 
986 	BUG_ON(idev->working_request == NULL);
987 
988 	isci_remote_device_not_ready(ihost, idev,
989 				     SCIC_REMOTE_DEVICE_NOT_READY_SMP_REQUEST_STARTED);
990 }
991 
992 static void sci_smp_remote_device_ready_cmd_substate_exit(struct sci_base_state_machine *sm)
993 {
994 	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
995 
996 	idev->working_request = NULL;
997 }
998 
999 static const struct sci_base_state sci_remote_device_state_table[] = {
1000 	[SCI_DEV_INITIAL] = {
1001 		.enter_state = sci_remote_device_initial_state_enter,
1002 	},
1003 	[SCI_DEV_STOPPED] = {
1004 		.enter_state = sci_remote_device_stopped_state_enter,
1005 	},
1006 	[SCI_DEV_STARTING] = {
1007 		.enter_state = sci_remote_device_starting_state_enter,
1008 	},
1009 	[SCI_DEV_READY] = {
1010 		.enter_state = sci_remote_device_ready_state_enter,
1011 		.exit_state  = sci_remote_device_ready_state_exit
1012 	},
1013 	[SCI_STP_DEV_IDLE] = {
1014 		.enter_state = sci_stp_remote_device_ready_idle_substate_enter,
1015 	},
1016 	[SCI_STP_DEV_CMD] = {
1017 		.enter_state = sci_stp_remote_device_ready_cmd_substate_enter,
1018 	},
1019 	[SCI_STP_DEV_NCQ] = { },
1020 	[SCI_STP_DEV_NCQ_ERROR] = {
1021 		.enter_state = sci_stp_remote_device_ready_ncq_error_substate_enter,
1022 	},
1023 	[SCI_STP_DEV_AWAIT_RESET] = { },
1024 	[SCI_SMP_DEV_IDLE] = {
1025 		.enter_state = sci_smp_remote_device_ready_idle_substate_enter,
1026 	},
1027 	[SCI_SMP_DEV_CMD] = {
1028 		.enter_state = sci_smp_remote_device_ready_cmd_substate_enter,
1029 		.exit_state  = sci_smp_remote_device_ready_cmd_substate_exit,
1030 	},
1031 	[SCI_DEV_STOPPING] = { },
1032 	[SCI_DEV_FAILED] = { },
1033 	[SCI_DEV_RESETTING] = {
1034 		.enter_state = sci_remote_device_resetting_state_enter,
1035 		.exit_state  = sci_remote_device_resetting_state_exit
1036 	},
1037 	[SCI_DEV_FINAL] = { },
1038 };
1039 
1040 /**
1041  * sci_remote_device_construct() - common construction
1042  * @sci_port: SAS/SATA port through which this device is accessed.
1043  * @sci_dev: remote device to construct
1044  *
1045  * This routine just performs benign initialization and does not
1046  * allocate the remote_node_context which is left to
1047  * sci_remote_device_[de]a_construct().  sci_remote_device_destruct()
1048  * frees the remote_node_context(s) for the device.
1049  */
1050 static void sci_remote_device_construct(struct isci_port *iport,
1051 				  struct isci_remote_device *idev)
1052 {
1053 	idev->owning_port = iport;
1054 	idev->started_request_count = 0;
1055 
1056 	sci_init_sm(&idev->sm, sci_remote_device_state_table, SCI_DEV_INITIAL);
1057 
1058 	sci_remote_node_context_construct(&idev->rnc,
1059 					       SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX);
1060 }
1061 
1062 /**
1063  * sci_remote_device_da_construct() - construct direct attached device.
1064  *
1065  * The information (e.g. IAF, Signature FIS, etc.) necessary to build
1066  * the device is known to the SCI Core since it is contained in the
1067  * sci_phy object.  Remote node context(s) is/are a global resource
1068  * allocated by this routine, freed by sci_remote_device_destruct().
1069  *
1070  * Returns:
1071  * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
1072  * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
1073  * sata-only controller instance.
1074  * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
1075  */
1076 static enum sci_status sci_remote_device_da_construct(struct isci_port *iport,
1077 						       struct isci_remote_device *idev)
1078 {
1079 	enum sci_status status;
1080 	struct domain_device *dev = idev->domain_dev;
1081 
1082 	sci_remote_device_construct(iport, idev);
1083 
1084 	/*
1085 	 * This information is request to determine how many remote node context
1086 	 * entries will be needed to store the remote node.
1087 	 */
1088 	idev->is_direct_attached = true;
1089 	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
1090 								  idev,
1091 								  &idev->rnc.remote_node_index);
1092 
1093 	if (status != SCI_SUCCESS)
1094 		return status;
1095 
1096 	if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
1097 	    (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
1098 		/* pass */;
1099 	else
1100 		return SCI_FAILURE_UNSUPPORTED_PROTOCOL;
1101 
1102 	idev->connection_rate = sci_port_get_max_allowed_speed(iport);
1103 
1104 	/* / @todo Should I assign the port width by reading all of the phys on the port? */
1105 	idev->device_port_width = 1;
1106 
1107 	return SCI_SUCCESS;
1108 }
1109 
1110 /**
1111  * sci_remote_device_ea_construct() - construct expander attached device
1112  *
1113  * Remote node context(s) is/are a global resource allocated by this
1114  * routine, freed by sci_remote_device_destruct().
1115  *
1116  * Returns:
1117  * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
1118  * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
1119  * sata-only controller instance.
1120  * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
1121  */
1122 static enum sci_status sci_remote_device_ea_construct(struct isci_port *iport,
1123 						       struct isci_remote_device *idev)
1124 {
1125 	struct domain_device *dev = idev->domain_dev;
1126 	enum sci_status status;
1127 
1128 	sci_remote_device_construct(iport, idev);
1129 
1130 	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
1131 								  idev,
1132 								  &idev->rnc.remote_node_index);
1133 	if (status != SCI_SUCCESS)
1134 		return status;
1135 
1136 	if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
1137 	    (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
1138 		/* pass */;
1139 	else
1140 		return SCI_FAILURE_UNSUPPORTED_PROTOCOL;
1141 
1142 	/*
1143 	 * For SAS-2 the physical link rate is actually a logical link
1144 	 * rate that incorporates multiplexing.  The SCU doesn't
1145 	 * incorporate multiplexing and for the purposes of the
1146 	 * connection the logical link rate is that same as the
1147 	 * physical.  Furthermore, the SAS-2 and SAS-1.1 fields overlay
1148 	 * one another, so this code works for both situations. */
1149 	idev->connection_rate = min_t(u16, sci_port_get_max_allowed_speed(iport),
1150 					 dev->linkrate);
1151 
1152 	/* / @todo Should I assign the port width by reading all of the phys on the port? */
1153 	idev->device_port_width = 1;
1154 
1155 	return SCI_SUCCESS;
1156 }
1157 
1158 /**
1159  * sci_remote_device_start() - This method will start the supplied remote
1160  *    device.  This method enables normal IO requests to flow through to the
1161  *    remote device.
1162  * @remote_device: This parameter specifies the device to be started.
1163  * @timeout: This parameter specifies the number of milliseconds in which the
1164  *    start operation should complete.
1165  *
1166  * An indication of whether the device was successfully started. SCI_SUCCESS
1167  * This value is returned if the device was successfully started.
1168  * SCI_FAILURE_INVALID_PHY This value is returned if the user attempts to start
1169  * the device when there have been no phys added to it.
1170  */
1171 static enum sci_status sci_remote_device_start(struct isci_remote_device *idev,
1172 						u32 timeout)
1173 {
1174 	struct sci_base_state_machine *sm = &idev->sm;
1175 	enum sci_remote_device_states state = sm->current_state_id;
1176 	enum sci_status status;
1177 
1178 	if (state != SCI_DEV_STOPPED) {
1179 		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
1180 			 __func__, state);
1181 		return SCI_FAILURE_INVALID_STATE;
1182 	}
1183 
1184 	status = sci_remote_node_context_resume(&idev->rnc,
1185 						     remote_device_resume_done,
1186 						     idev);
1187 	if (status != SCI_SUCCESS)
1188 		return status;
1189 
1190 	sci_change_state(sm, SCI_DEV_STARTING);
1191 
1192 	return SCI_SUCCESS;
1193 }
1194 
1195 static enum sci_status isci_remote_device_construct(struct isci_port *iport,
1196 						    struct isci_remote_device *idev)
1197 {
1198 	struct isci_host *ihost = iport->isci_host;
1199 	struct domain_device *dev = idev->domain_dev;
1200 	enum sci_status status;
1201 
1202 	if (dev->parent && dev_is_expander(dev->parent))
1203 		status = sci_remote_device_ea_construct(iport, idev);
1204 	else
1205 		status = sci_remote_device_da_construct(iport, idev);
1206 
1207 	if (status != SCI_SUCCESS) {
1208 		dev_dbg(&ihost->pdev->dev, "%s: construct failed: %d\n",
1209 			__func__, status);
1210 
1211 		return status;
1212 	}
1213 
1214 	/* start the device. */
1215 	status = sci_remote_device_start(idev, ISCI_REMOTE_DEVICE_START_TIMEOUT);
1216 
1217 	if (status != SCI_SUCCESS)
1218 		dev_warn(&ihost->pdev->dev, "remote device start failed: %d\n",
1219 			 status);
1220 
1221 	return status;
1222 }
1223 
1224 void isci_remote_device_nuke_requests(struct isci_host *ihost, struct isci_remote_device *idev)
1225 {
1226 	DECLARE_COMPLETION_ONSTACK(aborted_task_completion);
1227 
1228 	dev_dbg(&ihost->pdev->dev,
1229 		"%s: idev = %p\n", __func__, idev);
1230 
1231 	/* Cleanup all requests pending for this device. */
1232 	isci_terminate_pending_requests(ihost, idev);
1233 
1234 	dev_dbg(&ihost->pdev->dev,
1235 		"%s: idev = %p, done\n", __func__, idev);
1236 }
1237 
1238 /**
1239  * This function builds the isci_remote_device when a libsas dev_found message
1240  *    is received.
1241  * @isci_host: This parameter specifies the isci host object.
1242  * @port: This parameter specifies the isci_port conected to this device.
1243  *
1244  * pointer to new isci_remote_device.
1245  */
1246 static struct isci_remote_device *
1247 isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport)
1248 {
1249 	struct isci_remote_device *idev;
1250 	int i;
1251 
1252 	for (i = 0; i < SCI_MAX_REMOTE_DEVICES; i++) {
1253 		idev = &ihost->devices[i];
1254 		if (!test_and_set_bit(IDEV_ALLOCATED, &idev->flags))
1255 			break;
1256 	}
1257 
1258 	if (i >= SCI_MAX_REMOTE_DEVICES) {
1259 		dev_warn(&ihost->pdev->dev, "%s: failed\n", __func__);
1260 		return NULL;
1261 	}
1262 
1263 	if (WARN_ONCE(!list_empty(&idev->reqs_in_process), "found requests in process\n"))
1264 		return NULL;
1265 
1266 	if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n"))
1267 		return NULL;
1268 
1269 	return idev;
1270 }
1271 
1272 void isci_remote_device_release(struct kref *kref)
1273 {
1274 	struct isci_remote_device *idev = container_of(kref, typeof(*idev), kref);
1275 	struct isci_host *ihost = idev->isci_port->isci_host;
1276 
1277 	idev->domain_dev = NULL;
1278 	idev->isci_port = NULL;
1279 	clear_bit(IDEV_START_PENDING, &idev->flags);
1280 	clear_bit(IDEV_STOP_PENDING, &idev->flags);
1281 	clear_bit(IDEV_IO_READY, &idev->flags);
1282 	clear_bit(IDEV_GONE, &idev->flags);
1283 	clear_bit(IDEV_EH, &idev->flags);
1284 	smp_mb__before_clear_bit();
1285 	clear_bit(IDEV_ALLOCATED, &idev->flags);
1286 	wake_up(&ihost->eventq);
1287 }
1288 
1289 /**
1290  * isci_remote_device_stop() - This function is called internally to stop the
1291  *    remote device.
1292  * @isci_host: This parameter specifies the isci host object.
1293  * @isci_device: This parameter specifies the remote device.
1294  *
1295  * The status of the ihost request to stop.
1296  */
1297 enum sci_status isci_remote_device_stop(struct isci_host *ihost, struct isci_remote_device *idev)
1298 {
1299 	enum sci_status status;
1300 	unsigned long flags;
1301 
1302 	dev_dbg(&ihost->pdev->dev,
1303 		"%s: isci_device = %p\n", __func__, idev);
1304 
1305 	spin_lock_irqsave(&ihost->scic_lock, flags);
1306 	idev->domain_dev->lldd_dev = NULL; /* disable new lookups */
1307 	set_bit(IDEV_GONE, &idev->flags);
1308 	spin_unlock_irqrestore(&ihost->scic_lock, flags);
1309 
1310 	/* Kill all outstanding requests. */
1311 	isci_remote_device_nuke_requests(ihost, idev);
1312 
1313 	set_bit(IDEV_STOP_PENDING, &idev->flags);
1314 
1315 	spin_lock_irqsave(&ihost->scic_lock, flags);
1316 	status = sci_remote_device_stop(idev, 50);
1317 	spin_unlock_irqrestore(&ihost->scic_lock, flags);
1318 
1319 	/* Wait for the stop complete callback. */
1320 	if (WARN_ONCE(status != SCI_SUCCESS, "failed to stop device\n"))
1321 		/* nothing to wait for */;
1322 	else
1323 		wait_for_device_stop(ihost, idev);
1324 
1325 	return status;
1326 }
1327 
1328 /**
1329  * isci_remote_device_gone() - This function is called by libsas when a domain
1330  *    device is removed.
1331  * @domain_device: This parameter specifies the libsas domain device.
1332  *
1333  */
1334 void isci_remote_device_gone(struct domain_device *dev)
1335 {
1336 	struct isci_host *ihost = dev_to_ihost(dev);
1337 	struct isci_remote_device *idev = dev->lldd_dev;
1338 
1339 	dev_dbg(&ihost->pdev->dev,
1340 		"%s: domain_device = %p, isci_device = %p, isci_port = %p\n",
1341 		__func__, dev, idev, idev->isci_port);
1342 
1343 	isci_remote_device_stop(ihost, idev);
1344 }
1345 
1346 
1347 /**
1348  * isci_remote_device_found() - This function is called by libsas when a remote
1349  *    device is discovered. A remote device object is created and started. the
1350  *    function then sleeps until the sci core device started message is
1351  *    received.
1352  * @domain_device: This parameter specifies the libsas domain device.
1353  *
1354  * status, zero indicates success.
1355  */
1356 int isci_remote_device_found(struct domain_device *domain_dev)
1357 {
1358 	struct isci_host *isci_host = dev_to_ihost(domain_dev);
1359 	struct isci_port *isci_port;
1360 	struct isci_phy *isci_phy;
1361 	struct asd_sas_port *sas_port;
1362 	struct asd_sas_phy *sas_phy;
1363 	struct isci_remote_device *isci_device;
1364 	enum sci_status status;
1365 
1366 	dev_dbg(&isci_host->pdev->dev,
1367 		"%s: domain_device = %p\n", __func__, domain_dev);
1368 
1369 	wait_for_start(isci_host);
1370 
1371 	sas_port = domain_dev->port;
1372 	sas_phy = list_first_entry(&sas_port->phy_list, struct asd_sas_phy,
1373 				   port_phy_el);
1374 	isci_phy = to_iphy(sas_phy);
1375 	isci_port = isci_phy->isci_port;
1376 
1377 	/* we are being called for a device on this port,
1378 	 * so it has to come up eventually
1379 	 */
1380 	wait_for_completion(&isci_port->start_complete);
1381 
1382 	if ((isci_stopping == isci_port_get_state(isci_port)) ||
1383 	    (isci_stopped == isci_port_get_state(isci_port)))
1384 		return -ENODEV;
1385 
1386 	isci_device = isci_remote_device_alloc(isci_host, isci_port);
1387 	if (!isci_device)
1388 		return -ENODEV;
1389 
1390 	kref_init(&isci_device->kref);
1391 	INIT_LIST_HEAD(&isci_device->node);
1392 
1393 	spin_lock_irq(&isci_host->scic_lock);
1394 	isci_device->domain_dev = domain_dev;
1395 	isci_device->isci_port = isci_port;
1396 	list_add_tail(&isci_device->node, &isci_port->remote_dev_list);
1397 
1398 	set_bit(IDEV_START_PENDING, &isci_device->flags);
1399 	status = isci_remote_device_construct(isci_port, isci_device);
1400 
1401 	dev_dbg(&isci_host->pdev->dev,
1402 		"%s: isci_device = %p\n",
1403 		__func__, isci_device);
1404 
1405 	if (status == SCI_SUCCESS) {
1406 		/* device came up, advertise it to the world */
1407 		domain_dev->lldd_dev = isci_device;
1408 	} else
1409 		isci_put_device(isci_device);
1410 	spin_unlock_irq(&isci_host->scic_lock);
1411 
1412 	/* wait for the device ready callback. */
1413 	wait_for_device_start(isci_host, isci_device);
1414 
1415 	return status == SCI_SUCCESS ? 0 : -ENODEV;
1416 }
1417 /**
1418  * isci_device_is_reset_pending() - This function will check if there is any
1419  *    pending reset condition on the device.
1420  * @request: This parameter is the isci_device object.
1421  *
1422  * true if there is a reset pending for the device.
1423  */
1424 bool isci_device_is_reset_pending(
1425 	struct isci_host *isci_host,
1426 	struct isci_remote_device *isci_device)
1427 {
1428 	struct isci_request *isci_request;
1429 	struct isci_request *tmp_req;
1430 	bool reset_is_pending = false;
1431 	unsigned long flags;
1432 
1433 	dev_dbg(&isci_host->pdev->dev,
1434 		"%s: isci_device = %p\n", __func__, isci_device);
1435 
1436 	spin_lock_irqsave(&isci_host->scic_lock, flags);
1437 
1438 	/* Check for reset on all pending requests. */
1439 	list_for_each_entry_safe(isci_request, tmp_req,
1440 				 &isci_device->reqs_in_process, dev_node) {
1441 		dev_dbg(&isci_host->pdev->dev,
1442 			"%s: isci_device = %p request = %p\n",
1443 			__func__, isci_device, isci_request);
1444 
1445 		if (isci_request->ttype == io_task) {
1446 			struct sas_task *task = isci_request_access_task(
1447 				isci_request);
1448 
1449 			spin_lock(&task->task_state_lock);
1450 			if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET)
1451 				reset_is_pending = true;
1452 			spin_unlock(&task->task_state_lock);
1453 		}
1454 	}
1455 
1456 	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
1457 
1458 	dev_dbg(&isci_host->pdev->dev,
1459 		"%s: isci_device = %p reset_is_pending = %d\n",
1460 		__func__, isci_device, reset_is_pending);
1461 
1462 	return reset_is_pending;
1463 }
1464 
1465 /**
1466  * isci_device_clear_reset_pending() - This function will clear if any pending
1467  *    reset condition flags on the device.
1468  * @request: This parameter is the isci_device object.
1469  *
1470  * true if there is a reset pending for the device.
1471  */
1472 void isci_device_clear_reset_pending(struct isci_host *ihost, struct isci_remote_device *idev)
1473 {
1474 	struct isci_request *isci_request;
1475 	struct isci_request *tmp_req;
1476 	unsigned long flags = 0;
1477 
1478 	dev_dbg(&ihost->pdev->dev, "%s: idev=%p, ihost=%p\n",
1479 		 __func__, idev, ihost);
1480 
1481 	spin_lock_irqsave(&ihost->scic_lock, flags);
1482 
1483 	/* Clear reset pending on all pending requests. */
1484 	list_for_each_entry_safe(isci_request, tmp_req,
1485 				 &idev->reqs_in_process, dev_node) {
1486 		dev_dbg(&ihost->pdev->dev, "%s: idev = %p request = %p\n",
1487 			 __func__, idev, isci_request);
1488 
1489 		if (isci_request->ttype == io_task) {
1490 
1491 			unsigned long flags2;
1492 			struct sas_task *task = isci_request_access_task(
1493 				isci_request);
1494 
1495 			spin_lock_irqsave(&task->task_state_lock, flags2);
1496 			task->task_state_flags &= ~SAS_TASK_NEED_DEV_RESET;
1497 			spin_unlock_irqrestore(&task->task_state_lock, flags2);
1498 		}
1499 	}
1500 	spin_unlock_irqrestore(&ihost->scic_lock, flags);
1501 }
1502