Merge branch 'scsi-fixes'

1 files changed, 1501 insertions, 0 deletions

diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
new file mode 100644
index 000000000000..b6e6368c2665
--- /dev/null
+++ b/drivers/scsi/isci/remote_device.c
@@ -0,0 +1,1501 @@
+/*
+ * 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.h>
+#include "isci.h"
+#include "port.h"
+#include "remote_device.h"
+#include "request.h"
+#include "remote_node_context.h"
+#include "scu_event_codes.h"
+#include "task.h"
+
+/**
+ * isci_remote_device_not_ready() - This function is called by the ihost when
+ *    the remote device is not ready. We mark the isci device as ready (not
+ *    "ready_for_io") and signal the waiting proccess.
+ * @isci_host: This parameter specifies the isci host object.
+ * @isci_device: This parameter specifies the remote device
+ *
+ * sci_lock is held on entrance to this function.
+ */
+static void isci_remote_device_not_ready(struct isci_host *ihost,
+				  struct isci_remote_device *idev, u32 reason)
+{
+	struct isci_request *ireq;
+
+	dev_dbg(&ihost->pdev->dev,
+		"%s: isci_device = %p\n", __func__, idev);
+
+	switch (reason) {
+	case SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED:
+		set_bit(IDEV_GONE, &idev->flags);
+		break;
+	case SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED:
+		set_bit(IDEV_IO_NCQERROR, &idev->flags);
+
+		/* Kill all outstanding requests for the device. */
+		list_for_each_entry(ireq, &idev->reqs_in_process, dev_node) {
+
+			dev_dbg(&ihost->pdev->dev,
+				"%s: isci_device = %p request = %p\n",
+				__func__, idev, ireq);
+
+			sci_controller_terminate_request(ihost,
+							  idev,
+							  ireq);
+		}
+		/* Fall through into the default case... */
+	default:
+		clear_bit(IDEV_IO_READY, &idev->flags);
+		break;
+	}
+}
+
+/**
+ * isci_remote_device_ready() - This function is called by the ihost when the
+ *    remote device is ready. We mark the isci device as ready and signal the
+ *    waiting proccess.
+ * @ihost: our valid isci_host
+ * @idev: remote device
+ *
+ */
+static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+	dev_dbg(&ihost->pdev->dev,
+		"%s: idev = %p\n", __func__, idev);
+
+	clear_bit(IDEV_IO_NCQERROR, &idev->flags);
+	set_bit(IDEV_IO_READY, &idev->flags);
+	if (test_and_clear_bit(IDEV_START_PENDING, &idev->flags))
+		wake_up(&ihost->eventq);
+}
+
+/* called once the remote node context is ready to be freed.
+ * The remote device can now report that its stop operation is complete. none
+ */
+static void rnc_destruct_done(void *_dev)
+{
+	struct isci_remote_device *idev = _dev;
+
+	BUG_ON(idev->started_request_count != 0);
+	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
+}
+
+static enum sci_status sci_remote_device_terminate_requests(struct isci_remote_device *idev)
+{
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+	enum sci_status status  = SCI_SUCCESS;
+	u32 i;
+
+	for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
+		struct isci_request *ireq = ihost->reqs[i];
+		enum sci_status s;
+
+		if (!test_bit(IREQ_ACTIVE, &ireq->flags) ||
+		    ireq->target_device != idev)
+			continue;
+
+		s = sci_controller_terminate_request(ihost, idev, ireq);
+		if (s != SCI_SUCCESS)
+			status = s;
+	}
+
+	return status;
+}
+
+enum sci_status sci_remote_device_stop(struct isci_remote_device *idev,
+					u32 timeout)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_DEV_STOPPED:
+		return SCI_SUCCESS;
+	case SCI_DEV_STARTING:
+		/* device not started so there had better be no requests */
+		BUG_ON(idev->started_request_count != 0);
+		sci_remote_node_context_destruct(&idev->rnc,
+						      rnc_destruct_done, idev);
+		/* Transition to the stopping state and wait for the
+		 * remote node to complete being posted and invalidated.
+		 */
+		sci_change_state(sm, SCI_DEV_STOPPING);
+		return SCI_SUCCESS;
+	case SCI_DEV_READY:
+	case SCI_STP_DEV_IDLE:
+	case SCI_STP_DEV_CMD:
+	case SCI_STP_DEV_NCQ:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_STP_DEV_AWAIT_RESET:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_SMP_DEV_CMD:
+		sci_change_state(sm, SCI_DEV_STOPPING);
+		if (idev->started_request_count == 0) {
+			sci_remote_node_context_destruct(&idev->rnc,
+							      rnc_destruct_done, idev);
+			return SCI_SUCCESS;
+		} else
+			return sci_remote_device_terminate_requests(idev);
+		break;
+	case SCI_DEV_STOPPING:
+		/* All requests should have been terminated, but if there is an
+		 * attempt to stop a device already in the stopping state, then
+		 * try again to terminate.
+		 */
+		return sci_remote_device_terminate_requests(idev);
+	case SCI_DEV_RESETTING:
+		sci_change_state(sm, SCI_DEV_STOPPING);
+		return SCI_SUCCESS;
+	}
+}
+
+enum sci_status sci_remote_device_reset(struct isci_remote_device *idev)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_STOPPED:
+	case SCI_DEV_STARTING:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_SMP_DEV_CMD:
+	case SCI_DEV_STOPPING:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_RESETTING:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_DEV_READY:
+	case SCI_STP_DEV_IDLE:
+	case SCI_STP_DEV_CMD:
+	case SCI_STP_DEV_NCQ:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_STP_DEV_AWAIT_RESET:
+		sci_change_state(sm, SCI_DEV_RESETTING);
+		return SCI_SUCCESS;
+	}
+}
+
+enum sci_status sci_remote_device_reset_complete(struct isci_remote_device *idev)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+
+	if (state != SCI_DEV_RESETTING) {
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	}
+
+	sci_change_state(sm, SCI_DEV_READY);
+	return SCI_SUCCESS;
+}
+
+enum sci_status sci_remote_device_suspend(struct isci_remote_device *idev,
+					       u32 suspend_type)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+
+	if (state != SCI_STP_DEV_CMD) {
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	}
+
+	return sci_remote_node_context_suspend(&idev->rnc,
+						    suspend_type, NULL, NULL);
+}
+
+enum sci_status sci_remote_device_frame_handler(struct isci_remote_device *idev,
+						     u32 frame_index)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+	enum sci_status status;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_STOPPED:
+	case SCI_DEV_STARTING:
+	case SCI_STP_DEV_IDLE:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		/* Return the frame back to the controller */
+		sci_controller_release_frame(ihost, frame_index);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_DEV_READY:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_STP_DEV_AWAIT_RESET:
+	case SCI_DEV_STOPPING:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_RESETTING: {
+		struct isci_request *ireq;
+		struct ssp_frame_hdr hdr;
+		void *frame_header;
+		ssize_t word_cnt;
+
+		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
+								       frame_index,
+								       &frame_header);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		word_cnt = sizeof(hdr) / sizeof(u32);
+		sci_swab32_cpy(&hdr, frame_header, word_cnt);
+
+		ireq = sci_request_by_tag(ihost, be16_to_cpu(hdr.tag));
+		if (ireq && ireq->target_device == idev) {
+			/* The IO request is now in charge of releasing the frame */
+			status = sci_io_request_frame_handler(ireq, frame_index);
+		} else {
+			/* We could not map this tag to a valid IO
+			 * request Just toss the frame and continue
+			 */
+			sci_controller_release_frame(ihost, frame_index);
+		}
+		break;
+	}
+	case SCI_STP_DEV_NCQ: {
+		struct dev_to_host_fis *hdr;
+
+		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
+								       frame_index,
+								       (void **)&hdr);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		if (hdr->fis_type == FIS_SETDEVBITS &&
+		    (hdr->status & ATA_ERR)) {
+			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
+
+			/* TODO Check sactive and complete associated IO if any. */
+			sci_change_state(sm, SCI_STP_DEV_NCQ_ERROR);
+		} else if (hdr->fis_type == FIS_REGD2H &&
+			   (hdr->status & ATA_ERR)) {
+			/*
+			 * Some devices return D2H FIS when an NCQ error is detected.
+			 * Treat this like an SDB error FIS ready reason.
+			 */
+			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
+			sci_change_state(&idev->sm, SCI_STP_DEV_NCQ_ERROR);
+		} else
+			status = SCI_FAILURE;
+
+		sci_controller_release_frame(ihost, frame_index);
+		break;
+	}
+	case SCI_STP_DEV_CMD:
+	case SCI_SMP_DEV_CMD:
+		/* The device does not process any UF received from the hardware while
+		 * in this state.  All unsolicited frames are forwarded to the io request
+		 * object.
+		 */
+		status = sci_io_request_frame_handler(idev->working_request, frame_index);
+		break;
+	}
+
+	return status;
+}
+
+static bool is_remote_device_ready(struct isci_remote_device *idev)
+{
+
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+
+	switch (state) {
+	case SCI_DEV_READY:
+	case SCI_STP_DEV_IDLE:
+	case SCI_STP_DEV_CMD:
+	case SCI_STP_DEV_NCQ:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_STP_DEV_AWAIT_RESET:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_SMP_DEV_CMD:
+		return true;
+	default:
+		return false;
+	}
+}
+
+enum sci_status sci_remote_device_event_handler(struct isci_remote_device *idev,
+						     u32 event_code)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	enum sci_status status;
+
+	switch (scu_get_event_type(event_code)) {
+	case SCU_EVENT_TYPE_RNC_OPS_MISC:
+	case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
+	case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
+		status = sci_remote_node_context_event_handler(&idev->rnc, event_code);
+		break;
+	case SCU_EVENT_TYPE_PTX_SCHEDULE_EVENT:
+		if (scu_get_event_code(event_code) == SCU_EVENT_IT_NEXUS_TIMEOUT) {
+			status = SCI_SUCCESS;
+
+			/* Suspend the associated RNC */
+			sci_remote_node_context_suspend(&idev->rnc,
+							      SCI_SOFTWARE_SUSPENSION,
+							      NULL, NULL);
+
+			dev_dbg(scirdev_to_dev(idev),
+				"%s: device: %p event code: %x: %s\n",
+				__func__, idev, event_code,
+				is_remote_device_ready(idev)
+				? "I_T_Nexus_Timeout event"
+				: "I_T_Nexus_Timeout event in wrong state");
+
+			break;
+		}
+	/* Else, fall through and treat as unhandled... */
+	default:
+		dev_dbg(scirdev_to_dev(idev),
+			"%s: device: %p event code: %x: %s\n",
+			__func__, idev, event_code,
+			is_remote_device_ready(idev)
+			? "unexpected event"
+			: "unexpected event in wrong state");
+		status = SCI_FAILURE_INVALID_STATE;
+		break;
+	}
+
+	if (status != SCI_SUCCESS)
+		return status;
+
+	if (state == SCI_STP_DEV_IDLE) {
+
+		/* We pick up suspension events to handle specifically to this
+		 * state. We resume the RNC right away.
+		 */
+		if (scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX ||
+		    scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX)
+			status = sci_remote_node_context_resume(&idev->rnc, NULL, NULL);
+	}
+
+	return status;
+}
+
+static void sci_remote_device_start_request(struct isci_remote_device *idev,
+						 struct isci_request *ireq,
+						 enum sci_status status)
+{
+	struct isci_port *iport = idev->owning_port;
+
+	/* cleanup requests that failed after starting on the port */
+	if (status != SCI_SUCCESS)
+		sci_port_complete_io(iport, idev, ireq);
+	else {
+		kref_get(&idev->kref);
+		idev->started_request_count++;
+	}
+}
+
+enum sci_status sci_remote_device_start_io(struct isci_host *ihost,
+						struct isci_remote_device *idev,
+						struct isci_request *ireq)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	struct isci_port *iport = idev->owning_port;
+	enum sci_status status;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_STOPPED:
+	case SCI_DEV_STARTING:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_DEV_STOPPING:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_RESETTING:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_DEV_READY:
+		/* attempt to start an io request for this device object. The remote
+		 * device object will issue the start request for the io and if
+		 * successful it will start the request for the port object then
+		 * increment its own request count.
+		 */
+		status = sci_port_start_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		status = sci_request_start(ireq);
+		break;
+	case SCI_STP_DEV_IDLE: {
+		/* handle the start io operation for a sata device that is in
+		 * the command idle state. - Evalute the type of IO request to
+		 * be started - If its an NCQ request change to NCQ substate -
+		 * If its any other command change to the CMD substate
+		 *
+		 * If this is a softreset we may want to have a different
+		 * substate.
+		 */
+		enum sci_remote_device_states new_state;
+		struct sas_task *task = isci_request_access_task(ireq);
+
+		status = sci_port_start_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		status = sci_request_start(ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		if (task->ata_task.use_ncq)
+			new_state = SCI_STP_DEV_NCQ;
+		else {
+			idev->working_request = ireq;
+			new_state = SCI_STP_DEV_CMD;
+		}
+		sci_change_state(sm, new_state);
+		break;
+	}
+	case SCI_STP_DEV_NCQ: {
+		struct sas_task *task = isci_request_access_task(ireq);
+
+		if (task->ata_task.use_ncq) {
+			status = sci_port_start_io(iport, idev, ireq);
+			if (status != SCI_SUCCESS)
+				return status;
+
+			status = sci_remote_node_context_start_io(&idev->rnc, ireq);
+			if (status != SCI_SUCCESS)
+				break;
+
+			status = sci_request_start(ireq);
+		} else
+			return SCI_FAILURE_INVALID_STATE;
+		break;
+	}
+	case SCI_STP_DEV_AWAIT_RESET:
+		return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
+	case SCI_SMP_DEV_IDLE:
+		status = sci_port_start_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		status = sci_request_start(ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		idev->working_request = ireq;
+		sci_change_state(&idev->sm, SCI_SMP_DEV_CMD);
+		break;
+	case SCI_STP_DEV_CMD:
+	case SCI_SMP_DEV_CMD:
+		/* device is already handling a command it can not accept new commands
+		 * until this one is complete.
+		 */
+		return SCI_FAILURE_INVALID_STATE;
+	}
+
+	sci_remote_device_start_request(idev, ireq, status);
+	return status;
+}
+
+static enum sci_status common_complete_io(struct isci_port *iport,
+					  struct isci_remote_device *idev,
+					  struct isci_request *ireq)
+{
+	enum sci_status status;
+
+	status = sci_request_complete(ireq);
+	if (status != SCI_SUCCESS)
+		return status;
+
+	status = sci_port_complete_io(iport, idev, ireq);
+	if (status != SCI_SUCCESS)
+		return status;
+
+	sci_remote_device_decrement_request_count(idev);
+	return status;
+}
+
+enum sci_status sci_remote_device_complete_io(struct isci_host *ihost,
+						   struct isci_remote_device *idev,
+						   struct isci_request *ireq)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	struct isci_port *iport = idev->owning_port;
+	enum sci_status status;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_STOPPED:
+	case SCI_DEV_STARTING:
+	case SCI_STP_DEV_IDLE:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_DEV_READY:
+	case SCI_STP_DEV_AWAIT_RESET:
+	case SCI_DEV_RESETTING:
+		status = common_complete_io(iport, idev, ireq);
+		break;
+	case SCI_STP_DEV_CMD:
+	case SCI_STP_DEV_NCQ:
+	case SCI_STP_DEV_NCQ_ERROR:
+		status = common_complete_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		if (ireq->sci_status == SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
+			/* This request causes hardware error, device needs to be Lun Reset.
+			 * So here we force the state machine to IDLE state so the rest IOs
+			 * can reach RNC state handler, these IOs will be completed by RNC with
+			 * status of "DEVICE_RESET_REQUIRED", instead of "INVALID STATE".
+			 */
+			sci_change_state(sm, SCI_STP_DEV_AWAIT_RESET);
+		} else if (idev->started_request_count == 0)
+			sci_change_state(sm, SCI_STP_DEV_IDLE);
+		break;
+	case SCI_SMP_DEV_CMD:
+		status = common_complete_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+		sci_change_state(sm, SCI_SMP_DEV_IDLE);
+		break;
+	case SCI_DEV_STOPPING:
+		status = common_complete_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		if (idev->started_request_count == 0)
+			sci_remote_node_context_destruct(&idev->rnc,
+							 rnc_destruct_done,
+							 idev);
+		break;
+	}
+
+	if (status != SCI_SUCCESS)
+		dev_err(scirdev_to_dev(idev),
+			"%s: Port:0x%p Device:0x%p Request:0x%p Status:0x%x "
+			"could not complete\n", __func__, iport,
+			idev, ireq, status);
+	else
+		isci_put_device(idev);
+
+	return status;
+}
+
+static void sci_remote_device_continue_request(void *dev)
+{
+	struct isci_remote_device *idev = dev;
+
+	/* we need to check if this request is still valid to continue. */
+	if (idev->working_request)
+		sci_controller_continue_io(idev->working_request);
+}
+
+enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
+						  struct isci_remote_device *idev,
+						  struct isci_request *ireq)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	struct isci_port *iport = idev->owning_port;
+	enum sci_status status;
+
+	switch (state) {
+	case SCI_DEV_INITIAL:
+	case SCI_DEV_STOPPED:
+	case SCI_DEV_STARTING:
+	case SCI_SMP_DEV_IDLE:
+	case SCI_SMP_DEV_CMD:
+	case SCI_DEV_STOPPING:
+	case SCI_DEV_FAILED:
+	case SCI_DEV_RESETTING:
+	case SCI_DEV_FINAL:
+	default:
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	case SCI_STP_DEV_IDLE:
+	case SCI_STP_DEV_CMD:
+	case SCI_STP_DEV_NCQ:
+	case SCI_STP_DEV_NCQ_ERROR:
+	case SCI_STP_DEV_AWAIT_RESET:
+		status = sci_port_start_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
+		if (status != SCI_SUCCESS)
+			goto out;
+
+		status = sci_request_start(ireq);
+		if (status != SCI_SUCCESS)
+			goto out;
+
+		/* Note: If the remote device state is not IDLE this will
+		 * replace the request that probably resulted in the task
+		 * management request.
+		 */
+		idev->working_request = ireq;
+		sci_change_state(sm, SCI_STP_DEV_CMD);
+
+		/* The remote node context must cleanup the TCi to NCQ mapping
+		 * table.  The only way to do this correctly is to either write
+		 * to the TLCR register or to invalidate and repost the RNC. In
+		 * either case the remote node context state machine will take
+		 * the correct action when the remote node context is suspended
+		 * and later resumed.
+		 */
+		sci_remote_node_context_suspend(&idev->rnc,
+				SCI_SOFTWARE_SUSPENSION, NULL, NULL);
+		sci_remote_node_context_resume(&idev->rnc,
+				sci_remote_device_continue_request,
+						    idev);
+
+	out:
+		sci_remote_device_start_request(idev, ireq, status);
+		/* We need to let the controller start request handler know that
+		 * it can't post TC yet. We will provide a callback function to
+		 * post TC when RNC gets resumed.
+		 */
+		return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
+	case SCI_DEV_READY:
+		status = sci_port_start_io(iport, idev, ireq);
+		if (status != SCI_SUCCESS)
+			return status;
+
+		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
+		if (status != SCI_SUCCESS)
+			break;
+
+		status = sci_request_start(ireq);
+		break;
+	}
+	sci_remote_device_start_request(idev, ireq, status);
+
+	return status;
+}
+
+void sci_remote_device_post_request(struct isci_remote_device *idev, u32 request)
+{
+	struct isci_port *iport = idev->owning_port;
+	u32 context;
+
+	context = request |
+		  (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
+		  (iport->physical_port_index << SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
+		  idev->rnc.remote_node_index;
+
+	sci_controller_post_request(iport->owning_controller, context);
+}
+
+/* called once the remote node context has transisitioned to a
+ * ready state.  This is the indication that the remote device object can also
+ * transition to ready.
+ */
+static void remote_device_resume_done(void *_dev)
+{
+	struct isci_remote_device *idev = _dev;
+
+	if (is_remote_device_ready(idev))
+		return;
+
+	/* go 'ready' if we are not already in a ready state */
+	sci_change_state(&idev->sm, SCI_DEV_READY);
+}
+
+static void sci_stp_remote_device_ready_idle_substate_resume_complete_handler(void *_dev)
+{
+	struct isci_remote_device *idev = _dev;
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	/* For NCQ operation we do not issue a isci_remote_device_not_ready().
+	 * As a result, avoid sending the ready notification.
+	 */
+	if (idev->sm.previous_state_id != SCI_STP_DEV_NCQ)
+		isci_remote_device_ready(ihost, idev);
+}
+
+static void sci_remote_device_initial_state_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+
+	/* Initial state is a transitional state to the stopped state */
+	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
+}
+
+/**
+ * sci_remote_device_destruct() - free remote node context and destruct
+ * @remote_device: This parameter specifies the remote device to be destructed.
+ *
+ * Remote device objects are a limited resource.  As such, they must be
+ * protected.  Thus calls to construct and destruct are mutually exclusive and
+ * non-reentrant. The return value shall indicate if the device was
+ * successfully destructed or if some failure occurred. enum sci_status This value
+ * is returned if the device is successfully destructed.
+ * SCI_FAILURE_INVALID_REMOTE_DEVICE This value is returned if the supplied
+ * device isn't valid (e.g. it's already been destoryed, the handle isn't
+ * valid, etc.).
+ */
+static enum sci_status sci_remote_device_destruct(struct isci_remote_device *idev)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	struct isci_host *ihost;
+
+	if (state != SCI_DEV_STOPPED) {
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	}
+
+	ihost = idev->owning_port->owning_controller;
+	sci_controller_free_remote_node_context(ihost, idev,
+						     idev->rnc.remote_node_index);
+	idev->rnc.remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
+	sci_change_state(sm, SCI_DEV_FINAL);
+
+	return SCI_SUCCESS;
+}
+
+/**
+ * isci_remote_device_deconstruct() - This function frees an isci_remote_device.
+ * @ihost: This parameter specifies the isci host object.
+ * @idev: This parameter specifies the remote device to be freed.
+ *
+ */
+static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+	dev_dbg(&ihost->pdev->dev,
+		"%s: isci_device = %p\n", __func__, idev);
+
+	/* There should not be any outstanding io's. All paths to
+	 * here should go through isci_remote_device_nuke_requests.
+	 * If we hit this condition, we will need a way to complete
+	 * io requests in process */
+	BUG_ON(!list_empty(&idev->reqs_in_process));
+
+	sci_remote_device_destruct(idev);
+	list_del_init(&idev->node);
+	isci_put_device(idev);
+}
+
+static void sci_remote_device_stopped_state_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+	u32 prev_state;
+
+	/* If we are entering from the stopping state let the SCI User know that
+	 * the stop operation has completed.
+	 */
+	prev_state = idev->sm.previous_state_id;
+	if (prev_state == SCI_DEV_STOPPING)
+		isci_remote_device_deconstruct(ihost, idev);
+
+	sci_controller_remote_device_stopped(ihost, idev);
+}
+
+static void sci_remote_device_starting_state_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	isci_remote_device_not_ready(ihost, idev,
+				     SCIC_REMOTE_DEVICE_NOT_READY_START_REQUESTED);
+}
+
+static void sci_remote_device_ready_state_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+	struct domain_device *dev = idev->domain_dev;
+
+	if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_SATA)) {
+		sci_change_state(&idev->sm, SCI_STP_DEV_IDLE);
+	} else if (dev_is_expander(dev)) {
+		sci_change_state(&idev->sm, SCI_SMP_DEV_IDLE);
+	} else
+		isci_remote_device_ready(ihost, idev);
+}
+
+static void sci_remote_device_ready_state_exit(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct domain_device *dev = idev->domain_dev;
+
+	if (dev->dev_type == SAS_END_DEV) {
+		struct isci_host *ihost = idev->owning_port->owning_controller;
+
+		isci_remote_device_not_ready(ihost, idev,
+					     SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED);
+	}
+}
+
+static void sci_remote_device_resetting_state_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+
+	sci_remote_node_context_suspend(
+		&idev->rnc, SCI_SOFTWARE_SUSPENSION, NULL, NULL);
+}
+
+static void sci_remote_device_resetting_state_exit(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+
+	sci_remote_node_context_resume(&idev->rnc, NULL, NULL);
+}
+
+static void sci_stp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+
+	idev->working_request = NULL;
+	if (sci_remote_node_context_is_ready(&idev->rnc)) {
+		/*
+		 * Since the RNC is ready, it's alright to finish completion
+		 * processing (e.g. signal the remote device is ready). */
+		sci_stp_remote_device_ready_idle_substate_resume_complete_handler(idev);
+	} else {
+		sci_remote_node_context_resume(&idev->rnc,
+			sci_stp_remote_device_ready_idle_substate_resume_complete_handler,
+			idev);
+	}
+}
+
+static void sci_stp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	BUG_ON(idev->working_request == NULL);
+
+	isci_remote_device_not_ready(ihost, idev,
+				     SCIC_REMOTE_DEVICE_NOT_READY_SATA_REQUEST_STARTED);
+}
+
+static void sci_stp_remote_device_ready_ncq_error_substate_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	if (idev->not_ready_reason == SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED)
+		isci_remote_device_not_ready(ihost, idev,
+					     idev->not_ready_reason);
+}
+
+static void sci_smp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	isci_remote_device_ready(ihost, idev);
+}
+
+static void sci_smp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+
+	BUG_ON(idev->working_request == NULL);
+
+	isci_remote_device_not_ready(ihost, idev,
+				     SCIC_REMOTE_DEVICE_NOT_READY_SMP_REQUEST_STARTED);
+}
+
+static void sci_smp_remote_device_ready_cmd_substate_exit(struct sci_base_state_machine *sm)
+{
+	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
+
+	idev->working_request = NULL;
+}
+
+static const struct sci_base_state sci_remote_device_state_table[] = {
+	[SCI_DEV_INITIAL] = {
+		.enter_state = sci_remote_device_initial_state_enter,
+	},
+	[SCI_DEV_STOPPED] = {
+		.enter_state = sci_remote_device_stopped_state_enter,
+	},
+	[SCI_DEV_STARTING] = {
+		.enter_state = sci_remote_device_starting_state_enter,
+	},
+	[SCI_DEV_READY] = {
+		.enter_state = sci_remote_device_ready_state_enter,
+		.exit_state  = sci_remote_device_ready_state_exit
+	},
+	[SCI_STP_DEV_IDLE] = {
+		.enter_state = sci_stp_remote_device_ready_idle_substate_enter,
+	},
+	[SCI_STP_DEV_CMD] = {
+		.enter_state = sci_stp_remote_device_ready_cmd_substate_enter,
+	},
+	[SCI_STP_DEV_NCQ] = { },
+	[SCI_STP_DEV_NCQ_ERROR] = {
+		.enter_state = sci_stp_remote_device_ready_ncq_error_substate_enter,
+	},
+	[SCI_STP_DEV_AWAIT_RESET] = { },
+	[SCI_SMP_DEV_IDLE] = {
+		.enter_state = sci_smp_remote_device_ready_idle_substate_enter,
+	},
+	[SCI_SMP_DEV_CMD] = {
+		.enter_state = sci_smp_remote_device_ready_cmd_substate_enter,
+		.exit_state  = sci_smp_remote_device_ready_cmd_substate_exit,
+	},
+	[SCI_DEV_STOPPING] = { },
+	[SCI_DEV_FAILED] = { },
+	[SCI_DEV_RESETTING] = {
+		.enter_state = sci_remote_device_resetting_state_enter,
+		.exit_state  = sci_remote_device_resetting_state_exit
+	},
+	[SCI_DEV_FINAL] = { },
+};
+
+/**
+ * sci_remote_device_construct() - common construction
+ * @sci_port: SAS/SATA port through which this device is accessed.
+ * @sci_dev: remote device to construct
+ *
+ * This routine just performs benign initialization and does not
+ * allocate the remote_node_context which is left to
+ * sci_remote_device_[de]a_construct().  sci_remote_device_destruct()
+ * frees the remote_node_context(s) for the device.
+ */
+static void sci_remote_device_construct(struct isci_port *iport,
+				  struct isci_remote_device *idev)
+{
+	idev->owning_port = iport;
+	idev->started_request_count = 0;
+
+	sci_init_sm(&idev->sm, sci_remote_device_state_table, SCI_DEV_INITIAL);
+
+	sci_remote_node_context_construct(&idev->rnc,
+					       SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX);
+}
+
+/**
+ * sci_remote_device_da_construct() - construct direct attached device.
+ *
+ * The information (e.g. IAF, Signature FIS, etc.) necessary to build
+ * the device is known to the SCI Core since it is contained in the
+ * sci_phy object.  Remote node context(s) is/are a global resource
+ * allocated by this routine, freed by sci_remote_device_destruct().
+ *
+ * Returns:
+ * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
+ * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
+ * sata-only controller instance.
+ * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
+ */
+static enum sci_status sci_remote_device_da_construct(struct isci_port *iport,
+						       struct isci_remote_device *idev)
+{
+	enum sci_status status;
+	struct domain_device *dev = idev->domain_dev;
+
+	sci_remote_device_construct(iport, idev);
+
+	/*
+	 * This information is request to determine how many remote node context
+	 * entries will be needed to store the remote node.
+	 */
+	idev->is_direct_attached = true;
+	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
+								  idev,
+								  &idev->rnc.remote_node_index);
+
+	if (status != SCI_SUCCESS)
+		return status;
+
+	if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
+	    (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
+		/* pass */;
+	else
+		return SCI_FAILURE_UNSUPPORTED_PROTOCOL;
+
+	idev->connection_rate = sci_port_get_max_allowed_speed(iport);
+
+	/* / @todo Should I assign the port width by reading all of the phys on the port? */
+	idev->device_port_width = 1;
+
+	return SCI_SUCCESS;
+}
+
+/**
+ * sci_remote_device_ea_construct() - construct expander attached device
+ *
+ * Remote node context(s) is/are a global resource allocated by this
+ * routine, freed by sci_remote_device_destruct().
+ *
+ * Returns:
+ * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
+ * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
+ * sata-only controller instance.
+ * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
+ */
+static enum sci_status sci_remote_device_ea_construct(struct isci_port *iport,
+						       struct isci_remote_device *idev)
+{
+	struct domain_device *dev = idev->domain_dev;
+	enum sci_status status;
+
+	sci_remote_device_construct(iport, idev);
+
+	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
+								  idev,
+								  &idev->rnc.remote_node_index);
+	if (status != SCI_SUCCESS)
+		return status;
+
+	if (dev->dev_type == SAS_END_DEV || dev->dev_type == SATA_DEV ||
+	    (dev->tproto & SAS_PROTOCOL_STP) || dev_is_expander(dev))
+		/* pass */;
+	else
+		return SCI_FAILURE_UNSUPPORTED_PROTOCOL;
+
+	/*
+	 * For SAS-2 the physical link rate is actually a logical link
+	 * rate that incorporates multiplexing.  The SCU doesn't
+	 * incorporate multiplexing and for the purposes of the
+	 * connection the logical link rate is that same as the
+	 * physical.  Furthermore, the SAS-2 and SAS-1.1 fields overlay
+	 * one another, so this code works for both situations. */
+	idev->connection_rate = min_t(u16, sci_port_get_max_allowed_speed(iport),
+					 dev->linkrate);
+
+	/* / @todo Should I assign the port width by reading all of the phys on the port? */
+	idev->device_port_width = 1;
+
+	return SCI_SUCCESS;
+}
+
+/**
+ * sci_remote_device_start() - This method will start the supplied remote
+ *    device.  This method enables normal IO requests to flow through to the
+ *    remote device.
+ * @remote_device: This parameter specifies the device to be started.
+ * @timeout: This parameter specifies the number of milliseconds in which the
+ *    start operation should complete.
+ *
+ * An indication of whether the device was successfully started. SCI_SUCCESS
+ * This value is returned if the device was successfully started.
+ * SCI_FAILURE_INVALID_PHY This value is returned if the user attempts to start
+ * the device when there have been no phys added to it.
+ */
+static enum sci_status sci_remote_device_start(struct isci_remote_device *idev,
+						u32 timeout)
+{
+	struct sci_base_state_machine *sm = &idev->sm;
+	enum sci_remote_device_states state = sm->current_state_id;
+	enum sci_status status;
+
+	if (state != SCI_DEV_STOPPED) {
+		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %d\n",
+			 __func__, state);
+		return SCI_FAILURE_INVALID_STATE;
+	}
+
+	status = sci_remote_node_context_resume(&idev->rnc,
+						     remote_device_resume_done,
+						     idev);
+	if (status != SCI_SUCCESS)
+		return status;
+
+	sci_change_state(sm, SCI_DEV_STARTING);
+
+	return SCI_SUCCESS;
+}
+
+static enum sci_status isci_remote_device_construct(struct isci_port *iport,
+						    struct isci_remote_device *idev)
+{
+	struct isci_host *ihost = iport->isci_host;
+	struct domain_device *dev = idev->domain_dev;
+	enum sci_status status;
+
+	if (dev->parent && dev_is_expander(dev->parent))
+		status = sci_remote_device_ea_construct(iport, idev);
+	else
+		status = sci_remote_device_da_construct(iport, idev);
+
+	if (status != SCI_SUCCESS) {
+		dev_dbg(&ihost->pdev->dev, "%s: construct failed: %d\n",
+			__func__, status);
+
+		return status;
+	}
+
+	/* start the device. */
+	status = sci_remote_device_start(idev, ISCI_REMOTE_DEVICE_START_TIMEOUT);
+
+	if (status != SCI_SUCCESS)
+		dev_warn(&ihost->pdev->dev, "remote device start failed: %d\n",
+			 status);
+
+	return status;
+}
+
+void isci_remote_device_nuke_requests(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+	DECLARE_COMPLETION_ONSTACK(aborted_task_completion);
+
+	dev_dbg(&ihost->pdev->dev,
+		"%s: idev = %p\n", __func__, idev);
+
+	/* Cleanup all requests pending for this device. */
+	isci_terminate_pending_requests(ihost, idev);
+
+	dev_dbg(&ihost->pdev->dev,
+		"%s: idev = %p, done\n", __func__, idev);
+}
+
+/**
+ * This function builds the isci_remote_device when a libsas dev_found message
+ *    is received.
+ * @isci_host: This parameter specifies the isci host object.
+ * @port: This parameter specifies the isci_port conected to this device.
+ *
+ * pointer to new isci_remote_device.
+ */
+static struct isci_remote_device *
+isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport)
+{
+	struct isci_remote_device *idev;
+	int i;
+
+	for (i = 0; i < SCI_MAX_REMOTE_DEVICES; i++) {
+		idev = &ihost->devices[i];
+		if (!test_and_set_bit(IDEV_ALLOCATED, &idev->flags))
+			break;
+	}
+
+	if (i >= SCI_MAX_REMOTE_DEVICES) {
+		dev_warn(&ihost->pdev->dev, "%s: failed\n", __func__);
+		return NULL;
+	}
+
+	if (WARN_ONCE(!list_empty(&idev->reqs_in_process), "found requests in process\n"))
+		return NULL;
+
+	if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n"))
+		return NULL;
+
+	return idev;
+}
+
+void isci_remote_device_release(struct kref *kref)
+{
+	struct isci_remote_device *idev = container_of(kref, typeof(*idev), kref);
+	struct isci_host *ihost = idev->isci_port->isci_host;
+
+	idev->domain_dev = NULL;
+	idev->isci_port = NULL;
+	clear_bit(IDEV_START_PENDING, &idev->flags);
+	clear_bit(IDEV_STOP_PENDING, &idev->flags);
+	clear_bit(IDEV_IO_READY, &idev->flags);
+	clear_bit(IDEV_GONE, &idev->flags);
+	clear_bit(IDEV_EH, &idev->flags);
+	smp_mb__before_clear_bit();
+	clear_bit(IDEV_ALLOCATED, &idev->flags);
+	wake_up(&ihost->eventq);
+}
+
+/**
+ * isci_remote_device_stop() - This function is called internally to stop the
+ *    remote device.
+ * @isci_host: This parameter specifies the isci host object.
+ * @isci_device: This parameter specifies the remote device.
+ *
+ * The status of the ihost request to stop.
+ */
+enum sci_status isci_remote_device_stop(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+	enum sci_status status;
+	unsigned long flags;
+
+	dev_dbg(&ihost->pdev->dev,
+		"%s: isci_device = %p\n", __func__, idev);
+
+	spin_lock_irqsave(&ihost->scic_lock, flags);
+	idev->domain_dev->lldd_dev = NULL; /* disable new lookups */
+	set_bit(IDEV_GONE, &idev->flags);
+	spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+	/* Kill all outstanding requests. */
+	isci_remote_device_nuke_requests(ihost, idev);
+
+	set_bit(IDEV_STOP_PENDING, &idev->flags);
+
+	spin_lock_irqsave(&ihost->scic_lock, flags);
+	status = sci_remote_device_stop(idev, 50);
+	spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+	/* Wait for the stop complete callback. */
+	if (WARN_ONCE(status != SCI_SUCCESS, "failed to stop device\n"))
+		/* nothing to wait for */;
+	else
+		wait_for_device_stop(ihost, idev);
+
+	return status;
+}
+
+/**
+ * isci_remote_device_gone() - This function is called by libsas when a domain
+ *    device is removed.
+ * @domain_device: This parameter specifies the libsas domain device.
+ *
+ */
+void isci_remote_device_gone(struct domain_device *dev)
+{
+	struct isci_host *ihost = dev_to_ihost(dev);
+	struct isci_remote_device *idev = dev->lldd_dev;
+
+	dev_dbg(&ihost->pdev->dev,
+		"%s: domain_device = %p, isci_device = %p, isci_port = %p\n",
+		__func__, dev, idev, idev->isci_port);
+
+	isci_remote_device_stop(ihost, idev);
+}
+
+
+/**
+ * isci_remote_device_found() - This function is called by libsas when a remote
+ *    device is discovered. A remote device object is created and started. the
+ *    function then sleeps until the sci core device started message is
+ *    received.
+ * @domain_device: This parameter specifies the libsas domain device.
+ *
+ * status, zero indicates success.
+ */
+int isci_remote_device_found(struct domain_device *domain_dev)
+{
+	struct isci_host *isci_host = dev_to_ihost(domain_dev);
+	struct isci_port *isci_port;
+	struct isci_phy *isci_phy;
+	struct asd_sas_port *sas_port;
+	struct asd_sas_phy *sas_phy;
+	struct isci_remote_device *isci_device;
+	enum sci_status status;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: domain_device = %p\n", __func__, domain_dev);
+
+	wait_for_start(isci_host);
+
+	sas_port = domain_dev->port;
+	sas_phy = list_first_entry(&sas_port->phy_list, struct asd_sas_phy,
+				   port_phy_el);
+	isci_phy = to_iphy(sas_phy);
+	isci_port = isci_phy->isci_port;
+
+	/* we are being called for a device on this port,
+	 * so it has to come up eventually
+	 */
+	wait_for_completion(&isci_port->start_complete);
+
+	if ((isci_stopping == isci_port_get_state(isci_port)) ||
+	    (isci_stopped == isci_port_get_state(isci_port)))
+		return -ENODEV;
+
+	isci_device = isci_remote_device_alloc(isci_host, isci_port);
+	if (!isci_device)
+		return -ENODEV;
+
+	kref_init(&isci_device->kref);
+	INIT_LIST_HEAD(&isci_device->node);
+
+	spin_lock_irq(&isci_host->scic_lock);
+	isci_device->domain_dev = domain_dev;
+	isci_device->isci_port = isci_port;
+	list_add_tail(&isci_device->node, &isci_port->remote_dev_list);
+
+	set_bit(IDEV_START_PENDING, &isci_device->flags);
+	status = isci_remote_device_construct(isci_port, isci_device);
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device = %p\n",
+		__func__, isci_device);
+
+	if (status == SCI_SUCCESS) {
+		/* device came up, advertise it to the world */
+		domain_dev->lldd_dev = isci_device;
+	} else
+		isci_put_device(isci_device);
+	spin_unlock_irq(&isci_host->scic_lock);
+
+	/* wait for the device ready callback. */
+	wait_for_device_start(isci_host, isci_device);
+
+	return status == SCI_SUCCESS ? 0 : -ENODEV;
+}
+/**
+ * isci_device_is_reset_pending() - This function will check if there is any
+ *    pending reset condition on the device.
+ * @request: This parameter is the isci_device object.
+ *
+ * true if there is a reset pending for the device.
+ */
+bool isci_device_is_reset_pending(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device)
+{
+	struct isci_request *isci_request;
+	struct isci_request *tmp_req;
+	bool reset_is_pending = false;
+	unsigned long flags;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device = %p\n", __func__, isci_device);
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	/* Check for reset on all pending requests. */
+	list_for_each_entry_safe(isci_request, tmp_req,
+				 &isci_device->reqs_in_process, dev_node) {
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: isci_device = %p request = %p\n",
+			__func__, isci_device, isci_request);
+
+		if (isci_request->ttype == io_task) {
+			struct sas_task *task = isci_request_access_task(
+				isci_request);
+
+			spin_lock(&task->task_state_lock);
+			if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET)
+				reset_is_pending = true;
+			spin_unlock(&task->task_state_lock);
+		}
+	}
+
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device = %p reset_is_pending = %d\n",
+		__func__, isci_device, reset_is_pending);
+
+	return reset_is_pending;
+}
+
+/**
+ * isci_device_clear_reset_pending() - This function will clear if any pending
+ *    reset condition flags on the device.
+ * @request: This parameter is the isci_device object.
+ *
+ * true if there is a reset pending for the device.
+ */
+void isci_device_clear_reset_pending(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+	struct isci_request *isci_request;
+	struct isci_request *tmp_req;
+	unsigned long flags = 0;
+
+	dev_dbg(&ihost->pdev->dev, "%s: idev=%p, ihost=%p\n",
+		 __func__, idev, ihost);
+
+	spin_lock_irqsave(&ihost->scic_lock, flags);
+
+	/* Clear reset pending on all pending requests. */
+	list_for_each_entry_safe(isci_request, tmp_req,
+				 &idev->reqs_in_process, dev_node) {
+		dev_dbg(&ihost->pdev->dev, "%s: idev = %p request = %p\n",
+			 __func__, idev, isci_request);
+
+		if (isci_request->ttype == io_task) {
+
+			unsigned long flags2;
+			struct sas_task *task = isci_request_access_task(
+				isci_request);
+
+			spin_lock_irqsave(&task->task_state_lock, flags2);
+			task->task_state_flags &= ~SAS_TASK_NEED_DEV_RESET;
+			spin_unlock_irqrestore(&task->task_state_lock, flags2);
+		}
+	}
+	spin_unlock_irqrestore(&ihost->scic_lock, flags);
+}