WIP FPC-III support

[linux/fpc-iii.git] / drivers / scsi / isci / remote_node_context.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_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;
}
/**
 *
 * @sci_rnc:
 * @callback:
 * @callback_parameter:
 *
 * 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)
                        ? "<abort active>" : "<normal>");

        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;
        }
}