1b51fe55314d49af1a2bf422d29ebe5e852b0123
[linux-2.6.git] / drivers / scsi / isci / remote_node_context.c
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
56 #include "host.h"
57 #include "isci.h"
58 #include "remote_device.h"
59 #include "remote_node_context.h"
60 #include "scu_event_codes.h"
61 #include "scu_task_context.h"
62
63
64 /**
65  *
66  * @sci_rnc: The RNC for which the is posted request is being made.
67  *
68  * This method will return true if the RNC is not in the initial state.  In all
69  * other states the RNC is considered active and this will return true. The
70  * destroy request of the state machine drives the RNC back to the initial
71  * state.  If the state machine changes then this routine will also have to be
72  * changed. bool true if the state machine is not in the initial state false if
73  * the state machine is in the initial state
74  */
75
76 /**
77  *
78  * @sci_rnc: The state of the remote node context object to check.
79  *
80  * This method will return true if the remote node context is in a READY state
81  * otherwise it will return false bool true if the remote node context is in
82  * the ready state. false if the remote node context is not in the ready state.
83  */
84 bool scic_sds_remote_node_context_is_ready(
85         struct scic_sds_remote_node_context *sci_rnc)
86 {
87         u32 current_state = sci_rnc->sm.current_state_id;
88
89         if (current_state == SCI_RNC_READY) {
90                 return true;
91         }
92
93         return false;
94 }
95
96 /**
97  *
98  * @sci_dev: The remote device to use to construct the RNC buffer.
99  * @rnc: The buffer into which the remote device data will be copied.
100  *
101  * This method will construct the RNC buffer for this remote device object. none
102  */
103 static void scic_sds_remote_node_context_construct_buffer(
104         struct scic_sds_remote_node_context *sci_rnc)
105 {
106         struct scic_sds_remote_device *sci_dev = rnc_to_dev(sci_rnc);
107         struct domain_device *dev = sci_dev_to_domain(sci_dev);
108         int rni = sci_rnc->remote_node_index;
109         union scu_remote_node_context *rnc;
110         struct scic_sds_controller *scic;
111         __le64 sas_addr;
112
113         scic = scic_sds_remote_device_get_controller(sci_dev);
114         rnc = scic_sds_controller_get_remote_node_context_buffer(scic, rni);
115
116         memset(rnc, 0, sizeof(union scu_remote_node_context)
117                 * scic_sds_remote_device_node_count(sci_dev));
118
119         rnc->ssp.remote_node_index = rni;
120         rnc->ssp.remote_node_port_width = sci_dev->device_port_width;
121         rnc->ssp.logical_port_index = sci_dev->owning_port->physical_port_index;
122
123         /* sas address is __be64, context ram format is __le64 */
124         sas_addr = cpu_to_le64(SAS_ADDR(dev->sas_addr));
125         rnc->ssp.remote_sas_address_hi = upper_32_bits(sas_addr);
126         rnc->ssp.remote_sas_address_lo = lower_32_bits(sas_addr);
127
128         rnc->ssp.nexus_loss_timer_enable = true;
129         rnc->ssp.check_bit               = false;
130         rnc->ssp.is_valid                = false;
131         rnc->ssp.is_remote_node_context  = true;
132         rnc->ssp.function_number         = 0;
133
134         rnc->ssp.arbitration_wait_time = 0;
135
136         if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) {
137                 rnc->ssp.connection_occupancy_timeout =
138                         scic->user_parameters.sds1.stp_max_occupancy_timeout;
139                 rnc->ssp.connection_inactivity_timeout =
140                         scic->user_parameters.sds1.stp_inactivity_timeout;
141         } else {
142                 rnc->ssp.connection_occupancy_timeout  =
143                         scic->user_parameters.sds1.ssp_max_occupancy_timeout;
144                 rnc->ssp.connection_inactivity_timeout =
145                         scic->user_parameters.sds1.ssp_inactivity_timeout;
146         }
147
148         rnc->ssp.initial_arbitration_wait_time = 0;
149
150         /* Open Address Frame Parameters */
151         rnc->ssp.oaf_connection_rate = sci_dev->connection_rate;
152         rnc->ssp.oaf_features = 0;
153         rnc->ssp.oaf_source_zone_group = 0;
154         rnc->ssp.oaf_more_compatibility_features = 0;
155 }
156
157 /**
158  *
159  * @sci_rnc:
160  * @callback:
161  * @callback_parameter:
162  *
163  * This method will setup the remote node context object so it will transition
164  * to its ready state.  If the remote node context is already setup to
165  * transition to its final state then this function does nothing. none
166  */
167 static void scic_sds_remote_node_context_setup_to_resume(
168         struct scic_sds_remote_node_context *sci_rnc,
169         scics_sds_remote_node_context_callback callback,
170         void *callback_parameter)
171 {
172         if (sci_rnc->destination_state != SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL) {
173                 sci_rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY;
174                 sci_rnc->user_callback     = callback;
175                 sci_rnc->user_cookie       = callback_parameter;
176         }
177 }
178
179 static void scic_sds_remote_node_context_setup_to_destory(
180         struct scic_sds_remote_node_context *sci_rnc,
181         scics_sds_remote_node_context_callback callback,
182         void *callback_parameter)
183 {
184         sci_rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL;
185         sci_rnc->user_callback     = callback;
186         sci_rnc->user_cookie       = callback_parameter;
187 }
188
189 /**
190  *
191  *
192  * This method just calls the user callback function and then resets the
193  * callback.
194  */
195 static void scic_sds_remote_node_context_notify_user(
196         struct scic_sds_remote_node_context *rnc)
197 {
198         if (rnc->user_callback != NULL) {
199                 (*rnc->user_callback)(rnc->user_cookie);
200
201                 rnc->user_callback = NULL;
202                 rnc->user_cookie = NULL;
203         }
204 }
205
206 static void scic_sds_remote_node_context_continue_state_transitions(struct scic_sds_remote_node_context *rnc)
207 {
208         if (rnc->destination_state == SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY)
209                 scic_sds_remote_node_context_resume(rnc, rnc->user_callback,
210                                                     rnc->user_cookie);
211 }
212
213 /**
214  *
215  * @sci_rnc: The remote node context object that is to be validated.
216  *
217  * This method will mark the rnc buffer as being valid and post the request to
218  * the hardware. none
219  */
220 static void scic_sds_remote_node_context_validate_context_buffer(
221         struct scic_sds_remote_node_context *sci_rnc)
222 {
223         struct scic_sds_remote_device *sci_dev = rnc_to_dev(sci_rnc);
224         struct domain_device *dev = sci_dev_to_domain(sci_dev);
225         union scu_remote_node_context *rnc_buffer;
226
227         rnc_buffer = scic_sds_controller_get_remote_node_context_buffer(
228                 scic_sds_remote_device_get_controller(sci_dev),
229                 sci_rnc->remote_node_index
230                 );
231
232         rnc_buffer->ssp.is_valid = true;
233
234         if (!sci_dev->is_direct_attached &&
235             (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP))) {
236                 scic_sds_remote_device_post_request(sci_dev,
237                                                     SCU_CONTEXT_COMMAND_POST_RNC_96);
238         } else {
239                 scic_sds_remote_device_post_request(sci_dev, SCU_CONTEXT_COMMAND_POST_RNC_32);
240
241                 if (sci_dev->is_direct_attached) {
242                         scic_sds_port_setup_transports(sci_dev->owning_port,
243                                                        sci_rnc->remote_node_index);
244                 }
245         }
246 }
247
248 /**
249  *
250  * @sci_rnc: The remote node context object that is to be invalidated.
251  *
252  * This method will update the RNC buffer and post the invalidate request. none
253  */
254 static void scic_sds_remote_node_context_invalidate_context_buffer(
255         struct scic_sds_remote_node_context *sci_rnc)
256 {
257         union scu_remote_node_context *rnc_buffer;
258
259         rnc_buffer = scic_sds_controller_get_remote_node_context_buffer(
260                 scic_sds_remote_device_get_controller(rnc_to_dev(sci_rnc)),
261                 sci_rnc->remote_node_index);
262
263         rnc_buffer->ssp.is_valid = false;
264
265         scic_sds_remote_device_post_request(rnc_to_dev(sci_rnc),
266                                             SCU_CONTEXT_COMMAND_POST_RNC_INVALIDATE);
267 }
268
269 static void scic_sds_remote_node_context_initial_state_enter(struct sci_base_state_machine *sm)
270 {
271         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
272
273         /* Check to see if we have gotten back to the initial state because
274          * someone requested to destroy the remote node context object.
275          */
276         if (sm->previous_state_id == SCI_RNC_INVALIDATING) {
277                 rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
278                 scic_sds_remote_node_context_notify_user(rnc);
279         }
280 }
281
282 static void scic_sds_remote_node_context_posting_state_enter(struct sci_base_state_machine *sm)
283 {
284         struct scic_sds_remote_node_context *sci_rnc = container_of(sm, typeof(*sci_rnc), sm);
285
286         scic_sds_remote_node_context_validate_context_buffer(sci_rnc);
287 }
288
289 static void scic_sds_remote_node_context_invalidating_state_enter(struct sci_base_state_machine *sm)
290 {
291         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
292
293         scic_sds_remote_node_context_invalidate_context_buffer(rnc);
294 }
295
296 static void scic_sds_remote_node_context_resuming_state_enter(struct sci_base_state_machine *sm)
297 {
298         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
299         struct scic_sds_remote_device *sci_dev;
300         struct domain_device *dev;
301
302         sci_dev = rnc_to_dev(rnc);
303         dev = sci_dev_to_domain(sci_dev);
304
305         /*
306          * For direct attached SATA devices we need to clear the TLCR
307          * NCQ to TCi tag mapping on the phy and in cases where we
308          * resume because of a target reset we also need to update
309          * the STPTLDARNI register with the RNi of the device
310          */
311         if ((dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) &&
312             sci_dev->is_direct_attached)
313                 scic_sds_port_setup_transports(sci_dev->owning_port,
314                                                rnc->remote_node_index);
315
316         scic_sds_remote_device_post_request(sci_dev, SCU_CONTEXT_COMMAND_POST_RNC_RESUME);
317 }
318
319 static void scic_sds_remote_node_context_ready_state_enter(struct sci_base_state_machine *sm)
320 {
321         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
322
323         rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
324
325         if (rnc->user_callback)
326                 scic_sds_remote_node_context_notify_user(rnc);
327 }
328
329 static void scic_sds_remote_node_context_tx_suspended_state_enter(struct sci_base_state_machine *sm)
330 {
331         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
332
333         scic_sds_remote_node_context_continue_state_transitions(rnc);
334 }
335
336 static void scic_sds_remote_node_context_tx_rx_suspended_state_enter(struct sci_base_state_machine *sm)
337 {
338         struct scic_sds_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
339
340         scic_sds_remote_node_context_continue_state_transitions(rnc);
341 }
342
343 static const struct sci_base_state scic_sds_remote_node_context_state_table[] = {
344         [SCI_RNC_INITIAL] = {
345                 .enter_state = scic_sds_remote_node_context_initial_state_enter,
346         },
347         [SCI_RNC_POSTING] = {
348                 .enter_state = scic_sds_remote_node_context_posting_state_enter,
349         },
350         [SCI_RNC_INVALIDATING] = {
351                 .enter_state = scic_sds_remote_node_context_invalidating_state_enter,
352         },
353         [SCI_RNC_RESUMING] = {
354                 .enter_state = scic_sds_remote_node_context_resuming_state_enter,
355         },
356         [SCI_RNC_READY] = {
357                 .enter_state = scic_sds_remote_node_context_ready_state_enter,
358         },
359         [SCI_RNC_TX_SUSPENDED] = {
360                 .enter_state = scic_sds_remote_node_context_tx_suspended_state_enter,
361         },
362         [SCI_RNC_TX_RX_SUSPENDED] = {
363                 .enter_state = scic_sds_remote_node_context_tx_rx_suspended_state_enter,
364         },
365         [SCI_RNC_AWAIT_SUSPENSION] = { },
366 };
367
368 void scic_sds_remote_node_context_construct(struct scic_sds_remote_node_context *rnc,
369                                             u16 remote_node_index)
370 {
371         memset(rnc, 0, sizeof(struct scic_sds_remote_node_context));
372
373         rnc->remote_node_index = remote_node_index;
374         rnc->destination_state = SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_UNSPECIFIED;
375
376         sci_init_sm(&rnc->sm, scic_sds_remote_node_context_state_table, SCI_RNC_INITIAL);
377 }
378
379 enum sci_status scic_sds_remote_node_context_event_handler(struct scic_sds_remote_node_context *sci_rnc,
380                                                            u32 event_code)
381 {
382         enum scis_sds_remote_node_context_states state;
383
384         state = sci_rnc->sm.current_state_id;
385         switch (state) {
386         case SCI_RNC_POSTING:
387                 switch (scu_get_event_code(event_code)) {
388                 case SCU_EVENT_POST_RNC_COMPLETE:
389                         sci_change_state(&sci_rnc->sm, SCI_RNC_READY);
390                         break;
391                 default:
392                         goto out;
393                 }
394                 break;
395         case SCI_RNC_INVALIDATING:
396                 if (scu_get_event_code(event_code) == SCU_EVENT_POST_RNC_INVALIDATE_COMPLETE) {
397                         if (sci_rnc->destination_state == SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_FINAL)
398                                 state = SCI_RNC_INITIAL;
399                         else
400                                 state = SCI_RNC_POSTING;
401                         sci_change_state(&sci_rnc->sm, state);
402                 } else {
403                         switch (scu_get_event_type(event_code)) {
404                         case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
405                         case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
406                                 /* We really dont care if the hardware is going to suspend
407                                  * the device since it's being invalidated anyway */
408                                 dev_dbg(scirdev_to_dev(rnc_to_dev(sci_rnc)),
409                                         "%s: SCIC Remote Node Context 0x%p was "
410                                         "suspeneded by hardware while being "
411                                         "invalidated.\n", __func__, sci_rnc);
412                                 break;
413                         default:
414                                 goto out;
415                         }
416                 }
417                 break;
418         case SCI_RNC_RESUMING:
419                 if (scu_get_event_code(event_code) == SCU_EVENT_POST_RCN_RELEASE) {
420                         sci_change_state(&sci_rnc->sm, SCI_RNC_READY);
421                 } else {
422                         switch (scu_get_event_type(event_code)) {
423                         case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
424                         case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
425                                 /* We really dont care if the hardware is going to suspend
426                                  * the device since it's being resumed anyway */
427                                 dev_dbg(scirdev_to_dev(rnc_to_dev(sci_rnc)),
428                                         "%s: SCIC Remote Node Context 0x%p was "
429                                         "suspeneded by hardware while being resumed.\n",
430                                         __func__, sci_rnc);
431                                 break;
432                         default:
433                                 goto out;
434                         }
435                 }
436                 break;
437         case SCI_RNC_READY:
438                 switch (scu_get_event_type(event_code)) {
439                 case SCU_EVENT_TL_RNC_SUSPEND_TX:
440                         sci_change_state(&sci_rnc->sm, SCI_RNC_TX_SUSPENDED);
441                         sci_rnc->suspension_code = scu_get_event_specifier(event_code);
442                         break;
443                 case SCU_EVENT_TL_RNC_SUSPEND_TX_RX:
444                         sci_change_state(&sci_rnc->sm, SCI_RNC_TX_RX_SUSPENDED);
445                         sci_rnc->suspension_code = scu_get_event_specifier(event_code);
446                         break;
447                 default:
448                         goto out;
449                 }
450                 break;
451         case SCI_RNC_AWAIT_SUSPENSION:
452                 switch (scu_get_event_type(event_code)) {
453                 case SCU_EVENT_TL_RNC_SUSPEND_TX:
454                         sci_change_state(&sci_rnc->sm, SCI_RNC_TX_SUSPENDED);
455                         sci_rnc->suspension_code = scu_get_event_specifier(event_code);
456                         break;
457                 case SCU_EVENT_TL_RNC_SUSPEND_TX_RX:
458                         sci_change_state(&sci_rnc->sm, SCI_RNC_TX_RX_SUSPENDED);
459                         sci_rnc->suspension_code = scu_get_event_specifier(event_code);
460                         break;
461                 default:
462                         goto out;
463                 }
464                 break;
465         default:
466                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
467                          "%s: invalid state %d\n", __func__, state);
468                 return SCI_FAILURE_INVALID_STATE;
469         }
470         return SCI_SUCCESS;
471
472  out:
473         dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
474                  "%s: code: %#x state: %d\n", __func__, event_code, state);
475         return SCI_FAILURE;
476
477 }
478
479 enum sci_status scic_sds_remote_node_context_destruct(struct scic_sds_remote_node_context *sci_rnc,
480                                                       scics_sds_remote_node_context_callback cb_fn,
481                                                       void *cb_p)
482 {
483         enum scis_sds_remote_node_context_states state;
484
485         state = sci_rnc->sm.current_state_id;
486         switch (state) {
487         case SCI_RNC_INVALIDATING:
488                 scic_sds_remote_node_context_setup_to_destory(sci_rnc, cb_fn, cb_p);
489                 return SCI_SUCCESS;
490         case SCI_RNC_POSTING:
491         case SCI_RNC_RESUMING:
492         case SCI_RNC_READY:
493         case SCI_RNC_TX_SUSPENDED:
494         case SCI_RNC_TX_RX_SUSPENDED:
495         case SCI_RNC_AWAIT_SUSPENSION:
496                 scic_sds_remote_node_context_setup_to_destory(sci_rnc, cb_fn, cb_p);
497                 sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
498                 return SCI_SUCCESS;
499         case SCI_RNC_INITIAL:
500                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
501                          "%s: invalid state %d\n", __func__, state);
502                 /* We have decided that the destruct request on the remote node context
503                  * can not fail since it is either in the initial/destroyed state or is
504                  * can be destroyed.
505                  */
506                 return SCI_SUCCESS;
507         default:
508                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
509                          "%s: invalid state %d\n", __func__, state);
510                 return SCI_FAILURE_INVALID_STATE;
511         }
512 }
513
514 enum sci_status scic_sds_remote_node_context_suspend(struct scic_sds_remote_node_context *sci_rnc,
515                                                      u32 suspend_type,
516                                                      scics_sds_remote_node_context_callback cb_fn,
517                                                      void *cb_p)
518 {
519         enum scis_sds_remote_node_context_states state;
520
521         state = sci_rnc->sm.current_state_id;
522         if (state != SCI_RNC_READY) {
523                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
524                          "%s: invalid state %d\n", __func__, state);
525                 return SCI_FAILURE_INVALID_STATE;
526         }
527
528         sci_rnc->user_callback   = cb_fn;
529         sci_rnc->user_cookie     = cb_p;
530         sci_rnc->suspension_code = suspend_type;
531
532         if (suspend_type == SCI_SOFTWARE_SUSPENSION) {
533                 scic_sds_remote_device_post_request(rnc_to_dev(sci_rnc),
534                                                     SCU_CONTEXT_COMMAND_POST_RNC_SUSPEND_TX);
535         }
536
537         sci_change_state(&sci_rnc->sm, SCI_RNC_AWAIT_SUSPENSION);
538         return SCI_SUCCESS;
539 }
540
541 enum sci_status scic_sds_remote_node_context_resume(struct scic_sds_remote_node_context *sci_rnc,
542                                                     scics_sds_remote_node_context_callback cb_fn,
543                                                     void *cb_p)
544 {
545         enum scis_sds_remote_node_context_states state;
546
547         state = sci_rnc->sm.current_state_id;
548         switch (state) {
549         case SCI_RNC_INITIAL:
550                 if (sci_rnc->remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
551                         return SCI_FAILURE_INVALID_STATE;
552
553                 scic_sds_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
554                 scic_sds_remote_node_context_construct_buffer(sci_rnc);
555                 sci_change_state(&sci_rnc->sm, SCI_RNC_POSTING);
556                 return SCI_SUCCESS;
557         case SCI_RNC_POSTING:
558         case SCI_RNC_INVALIDATING:
559         case SCI_RNC_RESUMING:
560                 if (sci_rnc->destination_state != SCIC_SDS_REMOTE_NODE_DESTINATION_STATE_READY)
561                         return SCI_FAILURE_INVALID_STATE;
562
563                 sci_rnc->user_callback = cb_fn;
564                 sci_rnc->user_cookie   = cb_p;
565                 return SCI_SUCCESS;
566         case SCI_RNC_TX_SUSPENDED: {
567                 struct scic_sds_remote_device *sci_dev = rnc_to_dev(sci_rnc);
568                 struct domain_device *dev = sci_dev_to_domain(sci_dev);
569
570                 scic_sds_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
571
572                 /* TODO: consider adding a resume action of NONE, INVALIDATE, WRITE_TLCR */
573                 if (dev->dev_type == SAS_END_DEV || dev_is_expander(dev))
574                         sci_change_state(&sci_rnc->sm, SCI_RNC_RESUMING);
575                 else if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) {
576                         if (sci_dev->is_direct_attached) {
577                                 /* @todo Fix this since I am being silly in writing to the STPTLDARNI register. */
578                                 sci_change_state(&sci_rnc->sm, SCI_RNC_RESUMING);
579                         } else {
580                                 sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
581                         }
582                 } else
583                         return SCI_FAILURE;
584                 return SCI_SUCCESS;
585         }
586         case SCI_RNC_TX_RX_SUSPENDED:
587                 scic_sds_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
588                 sci_change_state(&sci_rnc->sm, SCI_RNC_RESUMING);
589                 return SCI_FAILURE_INVALID_STATE;
590         case SCI_RNC_AWAIT_SUSPENSION:
591                 scic_sds_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p);
592                 return SCI_SUCCESS;
593         default:
594                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
595                          "%s: invalid state %d\n", __func__, state);
596                 return SCI_FAILURE_INVALID_STATE;
597         }
598 }
599
600 enum sci_status scic_sds_remote_node_context_start_io(struct scic_sds_remote_node_context *sci_rnc,
601                                                              struct isci_request *ireq)
602 {
603         enum scis_sds_remote_node_context_states state;
604
605         state = sci_rnc->sm.current_state_id;
606
607         switch (state) {
608         case SCI_RNC_READY:
609                 return SCI_SUCCESS;
610         case SCI_RNC_TX_SUSPENDED:
611         case SCI_RNC_TX_RX_SUSPENDED:
612         case SCI_RNC_AWAIT_SUSPENSION:
613                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
614                          "%s: invalid state %d\n", __func__, state);
615                 return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
616         default:
617                 break;
618         }
619         dev_dbg(scirdev_to_dev(rnc_to_dev(sci_rnc)),
620                 "%s: requested to start IO while still resuming, %d\n",
621                 __func__, state);
622         return SCI_FAILURE_INVALID_STATE;
623 }
624
625 enum sci_status scic_sds_remote_node_context_start_task(struct scic_sds_remote_node_context *sci_rnc,
626                                                         struct isci_request *ireq)
627 {
628         enum scis_sds_remote_node_context_states state;
629
630         state = sci_rnc->sm.current_state_id;
631         switch (state) {
632         case SCI_RNC_RESUMING:
633         case SCI_RNC_READY:
634         case SCI_RNC_AWAIT_SUSPENSION:
635                 return SCI_SUCCESS;
636         case SCI_RNC_TX_SUSPENDED:
637         case SCI_RNC_TX_RX_SUSPENDED:
638                 scic_sds_remote_node_context_resume(sci_rnc, NULL, NULL);
639                 return SCI_SUCCESS;
640         default:
641                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
642                          "%s: invalid state %d\n", __func__, state);
643                 return SCI_FAILURE_INVALID_STATE;
644         }
645 }