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