Quelle  remote_node_context.c   Sprache: C

/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <scsi/sas_ata.h>
#include "host.h"
#include "isci.h"
#include "remote_device.h"
#include "remote_node_context.h"
#include "scu_event_codes.h"
#include "scu_task_context.h"

#undef C
#define C(a) (#a)
const char *rnc_state_name(enum scis_sds_remote_node_context_states state)
{
 static const char * const strings[] = RNC_STATES;

 if (state >= ARRAY_SIZE(strings))
  return "UNKNOWN";

 return strings[state];
}
#undef C

/**
 * sci_remote_node_context_is_ready()
 * @sci_rnc: The state of the remote node context object to check.
 *
 * This method will return true if the remote node context is in a READY state
 * otherwise it will return false bool true if the remote node context is in
 * the ready state. false if the remote node context is not in the ready state.
 */
bool sci_remote_node_context_is_ready(
 struct sci_remote_node_context *sci_rnc)
{
 u32 current_state = sci_rnc->sm.current_state_id;

 if (current_state == SCI_RNC_READY) {
  return true;
 }

 return false;
}

bool sci_remote_node_context_is_suspended(struct sci_remote_node_context *sci_rnc)
{
 u32 current_state = sci_rnc->sm.current_state_id;

 if (current_state == SCI_RNC_TX_RX_SUSPENDED)
  return true;
 return false;
}

static union scu_remote_node_context *sci_rnc_by_id(struct isci_host *ihost, u16 id)
{
 if (id < ihost->remote_node_entries &&
     ihost->device_table[id])
  return &ihost->remote_node_context_table[id];

 return NULL;
}

static void sci_remote_node_context_construct_buffer(struct sci_remote_node_context *sci_rnc)
{
 struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 struct domain_device *dev = idev->domain_dev;
 int rni = sci_rnc->remote_node_index;
 union scu_remote_node_context *rnc;
 struct isci_host *ihost;
 __le64 sas_addr;

 ihost = idev->owning_port->owning_controller;
 rnc = sci_rnc_by_id(ihost, rni);

 memset(rnc, 0, sizeof(union scu_remote_node_context)
  * sci_remote_device_node_count(idev));

 rnc->ssp.remote_node_index = rni;
 rnc->ssp.remote_node_port_width = idev->device_port_width;
 rnc->ssp.logical_port_index = idev->owning_port->physical_port_index;

 /* sas address is __be64, context ram format is __le64 */
 sas_addr = cpu_to_le64(SAS_ADDR(dev->sas_addr));
 rnc->ssp.remote_sas_address_hi = upper_32_bits(sas_addr);
 rnc->ssp.remote_sas_address_lo = lower_32_bits(sas_addr);

 rnc->ssp.nexus_loss_timer_enable = true;
 rnc->ssp.check_bit               = false;
 rnc->ssp.is_valid                = false;
 rnc->ssp.is_remote_node_context  = true;
 rnc->ssp.function_number         = 0;

 rnc->ssp.arbitration_wait_time = 0;

 if (dev_is_sata(dev)) {
  rnc->ssp.connection_occupancy_timeout =
   ihost->user_parameters.stp_max_occupancy_timeout;
  rnc->ssp.connection_inactivity_timeout =
   ihost->user_parameters.stp_inactivity_timeout;
 } else {
  rnc->ssp.connection_occupancy_timeout  =
   ihost->user_parameters.ssp_max_occupancy_timeout;
  rnc->ssp.connection_inactivity_timeout =
   ihost->user_parameters.ssp_inactivity_timeout;
 }

 rnc->ssp.initial_arbitration_wait_time = 0;

 /* Open Address Frame Parameters */
 rnc->ssp.oaf_connection_rate = idev->connection_rate;
 rnc->ssp.oaf_features = 0;
 rnc->ssp.oaf_source_zone_group = 0;
 rnc->ssp.oaf_more_compatibility_features = 0;
}
/*
 * This method will setup the remote node context object so it will transition
 * to its ready state.  If the remote node context is already setup to
 * transition to its final state then this function does nothing. none
 */
static void sci_remote_node_context_setup_to_resume(
 struct sci_remote_node_context *sci_rnc,
 scics_sds_remote_node_context_callback callback,
 void *callback_parameter,
 enum sci_remote_node_context_destination_state dest_param)
{
 if (sci_rnc->destination_state != RNC_DEST_FINAL) {
  sci_rnc->destination_state = dest_param;
  if (callback != NULL) {
   sci_rnc->user_callback = callback;
   sci_rnc->user_cookie   = callback_parameter;
  }
 }
}

static void sci_remote_node_context_setup_to_destroy(
 struct sci_remote_node_context *sci_rnc,
 scics_sds_remote_node_context_callback callback,
 void *callback_parameter)
{
 struct isci_host *ihost = idev_to_ihost(rnc_to_dev(sci_rnc));

 sci_rnc->destination_state = RNC_DEST_FINAL;
 sci_rnc->user_callback     = callback;
 sci_rnc->user_cookie       = callback_parameter;

 wake_up(&ihost->eventq);
}

/*
 * This method just calls the user callback function and then resets the
 * callback.
 */
static void sci_remote_node_context_notify_user(
 struct sci_remote_node_context *rnc)
{
 if (rnc->user_callback != NULL) {
  (*rnc->user_callback)(rnc->user_cookie);

  rnc->user_callback = NULL;
  rnc->user_cookie = NULL;
 }
}

static void sci_remote_node_context_continue_state_transitions(struct sci_remote_node_context *rnc)
{
 switch (rnc->destination_state) {
 case RNC_DEST_READY:
 case RNC_DEST_SUSPENDED_RESUME:
  rnc->destination_state = RNC_DEST_READY;
  fallthrough;
 case RNC_DEST_FINAL:
  sci_remote_node_context_resume(rnc, rnc->user_callback,
            rnc->user_cookie);
  break;
 default:
  rnc->destination_state = RNC_DEST_UNSPECIFIED;
  break;
 }
}

static void sci_remote_node_context_validate_context_buffer(struct sci_remote_node_context *sci_rnc)
{
 union scu_remote_node_context *rnc_buffer;
 struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 struct domain_device *dev = idev->domain_dev;
 struct isci_host *ihost = idev->owning_port->owning_controller;

 rnc_buffer = sci_rnc_by_id(ihost, sci_rnc->remote_node_index);

 rnc_buffer->ssp.is_valid = true;

 if (dev_is_sata(dev) && dev->parent) {
  sci_remote_device_post_request(idev, SCU_CONTEXT_COMMAND_POST_RNC_96);
 } else {
  sci_remote_device_post_request(idev, SCU_CONTEXT_COMMAND_POST_RNC_32);

  if (!dev->parent)
   sci_port_setup_transports(idev->owning_port,
        sci_rnc->remote_node_index);
 }
}

static void sci_remote_node_context_invalidate_context_buffer(struct sci_remote_node_context *sci_rnc)
{
 union scu_remote_node_context *rnc_buffer;
 struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 struct isci_host *ihost = idev->owning_port->owning_controller;

 rnc_buffer = sci_rnc_by_id(ihost, sci_rnc->remote_node_index);

 rnc_buffer->ssp.is_valid = false;

 sci_remote_device_post_request(rnc_to_dev(sci_rnc),
           SCU_CONTEXT_COMMAND_POST_RNC_INVALIDATE);
}

static void sci_remote_node_context_initial_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
 struct isci_remote_device *idev = rnc_to_dev(rnc);
 struct isci_host *ihost = idev->owning_port->owning_controller;

 /* Check to see if we have gotten back to the initial state because
 * someone requested to destroy the remote node context object.
 */
 if (sm->previous_state_id == SCI_RNC_INVALIDATING) {
  rnc->destination_state = RNC_DEST_UNSPECIFIED;
  sci_remote_node_context_notify_user(rnc);

  smp_wmb();
  wake_up(&ihost->eventq);
 }
}

static void sci_remote_node_context_posting_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *sci_rnc = container_of(sm, typeof(*sci_rnc), sm);

 sci_remote_node_context_validate_context_buffer(sci_rnc);
}

static void sci_remote_node_context_invalidating_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);

 /* Terminate all outstanding requests. */
 sci_remote_device_terminate_requests(rnc_to_dev(rnc));
 sci_remote_node_context_invalidate_context_buffer(rnc);
}

static void sci_remote_node_context_resuming_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
 struct isci_remote_device *idev;
 struct domain_device *dev;

 idev = rnc_to_dev(rnc);
 dev = idev->domain_dev;

 /*
 * For direct attached SATA devices we need to clear the TLCR
 * NCQ to TCi tag mapping on the phy and in cases where we
 * resume because of a target reset we also need to update
 * the STPTLDARNI register with the RNi of the device
 */
 if (dev_is_sata(dev) && !dev->parent)
  sci_port_setup_transports(idev->owning_port, rnc->remote_node_index);

 sci_remote_device_post_request(idev, SCU_CONTEXT_COMMAND_POST_RNC_RESUME);
}

static void sci_remote_node_context_ready_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
 enum sci_remote_node_context_destination_state dest_select;
 int tell_user = 1;

 dest_select = rnc->destination_state;
 rnc->destination_state = RNC_DEST_UNSPECIFIED;

 if ((dest_select == RNC_DEST_SUSPENDED) ||
     (dest_select == RNC_DEST_SUSPENDED_RESUME)) {
  sci_remote_node_context_suspend(
   rnc, rnc->suspend_reason,
   SCI_SOFTWARE_SUSPEND_EXPECTED_EVENT);

  if (dest_select == RNC_DEST_SUSPENDED_RESUME)
   tell_user = 0;  /* Wait until ready again. */
 }
 if (tell_user)
  sci_remote_node_context_notify_user(rnc);
}

static void sci_remote_node_context_tx_suspended_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);

 sci_remote_node_context_continue_state_transitions(rnc);
}

static void sci_remote_node_context_tx_rx_suspended_state_enter(struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc = container_of(sm, typeof(*rnc), sm);
 struct isci_remote_device *idev = rnc_to_dev(rnc);
 struct isci_host *ihost = idev->owning_port->owning_controller;
 u32 new_count = rnc->suspend_count + 1;

 if (new_count == 0)
  rnc->suspend_count = 1;
 else
  rnc->suspend_count = new_count;
 smp_wmb();

 /* Terminate outstanding requests pending abort. */
 sci_remote_device_abort_requests_pending_abort(idev);

 wake_up(&ihost->eventq);
 sci_remote_node_context_continue_state_transitions(rnc);
}

static void sci_remote_node_context_await_suspend_state_exit(
 struct sci_base_state_machine *sm)
{
 struct sci_remote_node_context *rnc
  = container_of(sm, typeof(*rnc), sm);
 struct isci_remote_device *idev = rnc_to_dev(rnc);

 if (dev_is_sata(idev->domain_dev))
  isci_dev_set_hang_detection_timeout(idev, 0);
}

static const struct sci_base_state sci_remote_node_context_state_table[] = {
 [SCI_RNC_INITIAL] = {
  .enter_state = sci_remote_node_context_initial_state_enter,
 },
 [SCI_RNC_POSTING] = {
  .enter_state = sci_remote_node_context_posting_state_enter,
 },
 [SCI_RNC_INVALIDATING] = {
  .enter_state = sci_remote_node_context_invalidating_state_enter,
 },
 [SCI_RNC_RESUMING] = {
  .enter_state = sci_remote_node_context_resuming_state_enter,
 },
 [SCI_RNC_READY] = {
  .enter_state = sci_remote_node_context_ready_state_enter,
 },
 [SCI_RNC_TX_SUSPENDED] = {
  .enter_state = sci_remote_node_context_tx_suspended_state_enter,
 },
 [SCI_RNC_TX_RX_SUSPENDED] = {
  .enter_state = sci_remote_node_context_tx_rx_suspended_state_enter,
 },
 [SCI_RNC_AWAIT_SUSPENSION] = {
  .exit_state = sci_remote_node_context_await_suspend_state_exit,
 },
};

void sci_remote_node_context_construct(struct sci_remote_node_context *rnc,
         u16 remote_node_index)
{
 memset(rnc, 0, sizeof(struct sci_remote_node_context));

 rnc->remote_node_index = remote_node_index;
 rnc->destination_state = RNC_DEST_UNSPECIFIED;

 sci_init_sm(&rnc->sm, sci_remote_node_context_state_table, SCI_RNC_INITIAL);
}

enum sci_status sci_remote_node_context_event_handler(struct sci_remote_node_context *sci_rnc,
          u32 event_code)
{
 enum scis_sds_remote_node_context_states state;
 u32 next_state;

 state = sci_rnc->sm.current_state_id;
 switch (state) {
 case SCI_RNC_POSTING:
  switch (scu_get_event_code(event_code)) {
  case SCU_EVENT_POST_RNC_COMPLETE:
   sci_change_state(&sci_rnc->sm, SCI_RNC_READY);
   break;
  default:
   goto out;
  }
  break;
 case SCI_RNC_INVALIDATING:
  if (scu_get_event_code(event_code) == SCU_EVENT_POST_RNC_INVALIDATE_COMPLETE) {
   if (sci_rnc->destination_state == RNC_DEST_FINAL)
    next_state = SCI_RNC_INITIAL;
   else
    next_state = SCI_RNC_POSTING;
   sci_change_state(&sci_rnc->sm, next_state);
  } else {
   switch (scu_get_event_type(event_code)) {
   case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
   case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
    /* We really dont care if the hardware is going to suspend
 * the device since it's being invalidated anyway */
    dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
     "%s: SCIC Remote Node Context 0x%p was "
     "suspended by hardware while being "
     "invalidated.\n", __func__, sci_rnc);
    break;
   default:
    goto out;
   }
  }
  break;
 case SCI_RNC_RESUMING:
  if (scu_get_event_code(event_code) == SCU_EVENT_POST_RCN_RELEASE) {
   sci_change_state(&sci_rnc->sm, SCI_RNC_READY);
  } else {
   switch (scu_get_event_type(event_code)) {
   case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
   case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
    /* We really dont care if the hardware is going to suspend
 * the device since it's being resumed anyway */
    dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
     "%s: SCIC Remote Node Context 0x%p was "
     "suspended by hardware while being resumed.\n",
     __func__, sci_rnc);
    break;
   default:
    goto out;
   }
  }
  break;
 case SCI_RNC_READY:
  switch (scu_get_event_type(event_code)) {
  case SCU_EVENT_TL_RNC_SUSPEND_TX:
   sci_change_state(&sci_rnc->sm, SCI_RNC_TX_SUSPENDED);
   sci_rnc->suspend_type = scu_get_event_type(event_code);
   break;
  case SCU_EVENT_TL_RNC_SUSPEND_TX_RX:
   sci_change_state(&sci_rnc->sm, SCI_RNC_TX_RX_SUSPENDED);
   sci_rnc->suspend_type = scu_get_event_type(event_code);
   break;
  default:
   goto out;
  }
  break;
 case SCI_RNC_AWAIT_SUSPENSION:
  switch (scu_get_event_type(event_code)) {
  case SCU_EVENT_TL_RNC_SUSPEND_TX:
   next_state = SCI_RNC_TX_SUSPENDED;
   break;
  case SCU_EVENT_TL_RNC_SUSPEND_TX_RX:
   next_state = SCI_RNC_TX_RX_SUSPENDED;
   break;
  default:
   goto out;
  }
  if (sci_rnc->suspend_type == scu_get_event_type(event_code))
   sci_change_state(&sci_rnc->sm, next_state);
  break;
 default:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state: %s\n", __func__,
    rnc_state_name(state));
  return SCI_FAILURE_INVALID_STATE;
 }
 return SCI_SUCCESS;

 out:
 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
   "%s: code: %#x state: %s\n", __func__, event_code,
   rnc_state_name(state));
 return SCI_FAILURE;

}

enum sci_status sci_remote_node_context_destruct(struct sci_remote_node_context *sci_rnc,
            scics_sds_remote_node_context_callback cb_fn,
            void *cb_p)
{
 enum scis_sds_remote_node_context_states state;

 state = sci_rnc->sm.current_state_id;
 switch (state) {
 case SCI_RNC_INVALIDATING:
  sci_remote_node_context_setup_to_destroy(sci_rnc, cb_fn, cb_p);
  return SCI_SUCCESS;
 case SCI_RNC_POSTING:
 case SCI_RNC_RESUMING:
 case SCI_RNC_READY:
 case SCI_RNC_TX_SUSPENDED:
 case SCI_RNC_TX_RX_SUSPENDED:
  sci_remote_node_context_setup_to_destroy(sci_rnc, cb_fn, cb_p);
  sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
  return SCI_SUCCESS;
 case SCI_RNC_AWAIT_SUSPENSION:
  sci_remote_node_context_setup_to_destroy(sci_rnc, cb_fn, cb_p);
  return SCI_SUCCESS;
 case SCI_RNC_INITIAL:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state: %s\n", __func__,
    rnc_state_name(state));
  /* We have decided that the destruct request on the remote node context
 * can not fail since it is either in the initial/destroyed state or is
 * can be destroyed.
 */
  return SCI_SUCCESS;
 default:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state %s\n", __func__,
    rnc_state_name(state));
  return SCI_FAILURE_INVALID_STATE;
 }
}

enum sci_status sci_remote_node_context_suspend(
   struct sci_remote_node_context *sci_rnc,
   enum sci_remote_node_suspension_reasons suspend_reason,
   u32 suspend_type)
{
 enum scis_sds_remote_node_context_states state
  = sci_rnc->sm.current_state_id;
 struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 enum sci_status status = SCI_FAILURE_INVALID_STATE;
 enum sci_remote_node_context_destination_state dest_param =
  RNC_DEST_UNSPECIFIED;

 dev_dbg(scirdev_to_dev(idev),
  "%s: current state %s, current suspend_type %x dest state %d,"
   " arg suspend_reason %d, arg suspend_type %x",
  __func__, rnc_state_name(state), sci_rnc->suspend_type,
  sci_rnc->destination_state, suspend_reason,
  suspend_type);

 /* Disable automatic state continuations if explicitly suspending. */
 if ((suspend_reason == SCI_HW_SUSPEND) ||
     (sci_rnc->destination_state == RNC_DEST_FINAL))
  dest_param = sci_rnc->destination_state;

 switch (state) {
 case SCI_RNC_READY:
  break;
 case SCI_RNC_INVALIDATING:
  if (sci_rnc->destination_state == RNC_DEST_FINAL) {
   dev_warn(scirdev_to_dev(idev),
     "%s: already destroying %p\n",
     __func__, sci_rnc);
   return SCI_FAILURE_INVALID_STATE;
  }
  fallthrough; /* and handle like SCI_RNC_POSTING */
 case SCI_RNC_RESUMING:
  fallthrough; /* and handle like SCI_RNC_POSTING */
 case SCI_RNC_POSTING:
  /* Set the destination state to AWAIT - this signals the
 * entry into the SCI_RNC_READY state that a suspension
 * needs to be done immediately.
 */
  if (sci_rnc->destination_state != RNC_DEST_FINAL)
   sci_rnc->destination_state = RNC_DEST_SUSPENDED;
  sci_rnc->suspend_type = suspend_type;
  sci_rnc->suspend_reason = suspend_reason;
  return SCI_SUCCESS;

 case SCI_RNC_TX_SUSPENDED:
  if (suspend_type == SCU_EVENT_TL_RNC_SUSPEND_TX)
   status = SCI_SUCCESS;
  break;
 case SCI_RNC_TX_RX_SUSPENDED:
  if (suspend_type == SCU_EVENT_TL_RNC_SUSPEND_TX_RX)
   status = SCI_SUCCESS;
  break;
 case SCI_RNC_AWAIT_SUSPENSION:
  if ((sci_rnc->suspend_type == SCU_EVENT_TL_RNC_SUSPEND_TX_RX)
      || (suspend_type == sci_rnc->suspend_type))
   return SCI_SUCCESS;
  break;
 default:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state %s\n", __func__,
    rnc_state_name(state));
  return SCI_FAILURE_INVALID_STATE;
 }
 sci_rnc->destination_state = dest_param;
 sci_rnc->suspend_type = suspend_type;
 sci_rnc->suspend_reason = suspend_reason;

 if (status == SCI_SUCCESS) { /* Already in the destination state? */
  struct isci_host *ihost = idev->owning_port->owning_controller;

  wake_up_all(&ihost->eventq); /* Let observers look. */
  return SCI_SUCCESS;
 }
 if ((suspend_reason == SCI_SW_SUSPEND_NORMAL) ||
     (suspend_reason == SCI_SW_SUSPEND_LINKHANG_DETECT)) {

  if (suspend_reason == SCI_SW_SUSPEND_LINKHANG_DETECT)
   isci_dev_set_hang_detection_timeout(idev, 0x00000001);

  sci_remote_device_post_request(
   idev, SCI_SOFTWARE_SUSPEND_CMD);
 }
 if (state != SCI_RNC_AWAIT_SUSPENSION)
  sci_change_state(&sci_rnc->sm, SCI_RNC_AWAIT_SUSPENSION);

 return SCI_SUCCESS;
}

enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *sci_rnc,
          scics_sds_remote_node_context_callback cb_fn,
          void *cb_p)
{
 enum scis_sds_remote_node_context_states state;
 struct isci_remote_device *idev = rnc_to_dev(sci_rnc);

 state = sci_rnc->sm.current_state_id;
 dev_dbg(scirdev_to_dev(idev),
  "%s: state %s, cb_fn = %p, cb_p = %p; dest_state = %d; "
   "dev resume path %s\n",
  __func__, rnc_state_name(state), cb_fn, cb_p,
  sci_rnc->destination_state,
  test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags)
   ? "" : "");

 switch (state) {
 case SCI_RNC_INITIAL:
  if (sci_rnc->remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
   return SCI_FAILURE_INVALID_STATE;

  sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p,
       RNC_DEST_READY);
  if (!test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags)) {
   sci_remote_node_context_construct_buffer(sci_rnc);
   sci_change_state(&sci_rnc->sm, SCI_RNC_POSTING);
  }
  return SCI_SUCCESS;

 case SCI_RNC_POSTING:
 case SCI_RNC_INVALIDATING:
 case SCI_RNC_RESUMING:
  /* We are still waiting to post when a resume was
 * requested.
 */
  switch (sci_rnc->destination_state) {
  case RNC_DEST_SUSPENDED:
  case RNC_DEST_SUSPENDED_RESUME:
   /* Previously waiting to suspend after posting.
 * Now continue onto resumption.
 */
   sci_remote_node_context_setup_to_resume(
    sci_rnc, cb_fn, cb_p,
    RNC_DEST_SUSPENDED_RESUME);
   break;
  default:
   sci_remote_node_context_setup_to_resume(
    sci_rnc, cb_fn, cb_p,
    RNC_DEST_READY);
   break;
  }
  return SCI_SUCCESS;

 case SCI_RNC_TX_SUSPENDED:
 case SCI_RNC_TX_RX_SUSPENDED:
  {
   struct domain_device *dev = idev->domain_dev;
   /* If this is an expander attached SATA device we must
 * invalidate and repost the RNC since this is the only
 * way to clear the TCi to NCQ tag mapping table for
 * the RNi. All other device types we can just resume.
 */
   sci_remote_node_context_setup_to_resume(
    sci_rnc, cb_fn, cb_p, RNC_DEST_READY);

   if (!test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags)) {
    if ((dev_is_sata(dev) && dev->parent) ||
        (sci_rnc->destination_state == RNC_DEST_FINAL))
     sci_change_state(&sci_rnc->sm,
        SCI_RNC_INVALIDATING);
    else
     sci_change_state(&sci_rnc->sm,
        SCI_RNC_RESUMING);
   }
  }
  return SCI_SUCCESS;

 case SCI_RNC_AWAIT_SUSPENSION:
  sci_remote_node_context_setup_to_resume(
   sci_rnc, cb_fn, cb_p, RNC_DEST_SUSPENDED_RESUME);
  return SCI_SUCCESS;
 default:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state %s\n", __func__,
    rnc_state_name(state));
  return SCI_FAILURE_INVALID_STATE;
 }
}

enum sci_status sci_remote_node_context_start_io(struct sci_remote_node_context *sci_rnc,
            struct isci_request *ireq)
{
 enum scis_sds_remote_node_context_states state;

 state = sci_rnc->sm.current_state_id;

 switch (state) {
 case SCI_RNC_READY:
  return SCI_SUCCESS;
 case SCI_RNC_TX_SUSPENDED:
 case SCI_RNC_TX_RX_SUSPENDED:
 case SCI_RNC_AWAIT_SUSPENSION:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state %s\n", __func__,
    rnc_state_name(state));
  return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
 default:
  dev_dbg(scirdev_to_dev(rnc_to_dev(sci_rnc)),
   "%s: invalid state %s\n", __func__,
   rnc_state_name(state));
  return SCI_FAILURE_INVALID_STATE;
 }
}

enum sci_status sci_remote_node_context_start_task(
 struct sci_remote_node_context *sci_rnc,
 struct isci_request *ireq,
 scics_sds_remote_node_context_callback cb_fn,
 void *cb_p)
{
 enum sci_status status = sci_remote_node_context_resume(sci_rnc,
        cb_fn, cb_p);
 if (status != SCI_SUCCESS)
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
   "%s: resume failed: %d\n", __func__, status);
 return status;
}

int sci_remote_node_context_is_safe_to_abort(
 struct sci_remote_node_context *sci_rnc)
{
 enum scis_sds_remote_node_context_states state;

 state = sci_rnc->sm.current_state_id;
 switch (state) {
 case SCI_RNC_INVALIDATING:
 case SCI_RNC_TX_RX_SUSPENDED:
  return 1;
 case SCI_RNC_POSTING:
 case SCI_RNC_RESUMING:
 case SCI_RNC_READY:
 case SCI_RNC_TX_SUSPENDED:
 case SCI_RNC_AWAIT_SUSPENSION:
 case SCI_RNC_INITIAL:
  return 0;
 default:
  dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
    "%s: invalid state %d\n", __func__, state);
  return 0;
 }
}