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