isci: Intel(R) C600 Series Chipset Storage Control Unit Driver

Support for the up to 2x4-port 6Gb/s SAS controllers embedded in the
chipset.

This is a snapshot of the first publicly available version of the driver,
commit 4c1db2d0 in the 'historical' branch.

   git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci.git historical

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 1691 insertions, 0 deletions

diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
new file mode 100644
index 000000000000..5e6f55863407
--- /dev/null
+++ b/drivers/scsi/isci/task.c
@@ -0,0 +1,1691 @@
+/*
+ * 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 <linux/completion.h>
+#include "scic_task_request.h"
+#include "scic_remote_device.h"
+#include "scic_io_request.h"
+#include "scic_sds_remote_device.h"
+#include "scic_sds_remote_node_context.h"
+#include "isci.h"
+#include "request.h"
+#include "sata.h"
+#include "task.h"
+
+
+/**
+ * isci_task_execute_task() - This function is one of the SAS Domain Template
+ *    functions. This function is called by libsas to send a task down to
+ *    hardware.
+ * @task: This parameter specifies the SAS task to send.
+ * @num: This parameter specifies the number of tasks to queue.
+ * @gfp_flags: This parameter specifies the context of this call.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
+{
+	struct isci_host *isci_host;
+	struct isci_request *request = NULL;
+	struct isci_remote_device *device;
+	unsigned long flags;
+	unsigned long quiesce_flags = 0;
+	int ret;
+	enum sci_status status;
+
+
+	dev_dbg(task->dev->port->ha->dev, "%s: num=%d\n", __func__, num);
+
+	if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
+
+		isci_task_complete_for_upper_layer(
+			task,
+			SAS_TASK_UNDELIVERED,
+			SAM_STAT_TASK_ABORTED,
+			isci_perform_normal_io_completion
+			);
+
+		return 0;  /* The I/O was accepted (and failed). */
+	}
+	if ((task->dev == NULL) || (task->dev->port == NULL)) {
+
+		/* Indicate SAS_TASK_UNDELIVERED, so that the scsi midlayer
+		 * removes the target.
+		 */
+		isci_task_complete_for_upper_layer(
+			task,
+			SAS_TASK_UNDELIVERED,
+			SAS_DEVICE_UNKNOWN,
+			isci_perform_normal_io_completion
+			);
+		return 0;  /* The I/O was accepted (and failed). */
+	}
+	isci_host = isci_host_from_sas_ha(task->dev->port->ha);
+
+	/* Check if we have room for more tasks */
+	ret = isci_host_can_queue(isci_host, num);
+
+	if (ret) {
+		dev_warn(task->dev->port->ha->dev, "%s: queue full\n", __func__);
+		return ret;
+	}
+
+	do {
+		dev_dbg(task->dev->port->ha->dev,
+			"task = %p, num = %d; dev = %p; cmd = %p\n",
+			    task, num, task->dev, task->uldd_task);
+
+		if ((task->dev == NULL) || (task->dev->port == NULL)) {
+			dev_warn(task->dev->port->ha->dev,
+				 "%s: task %p's port or dev == NULL!\n",
+				 __func__, task);
+
+			/* Indicate SAS_TASK_UNDELIVERED, so that the scsi
+			 * midlayer removes the target.
+			 */
+			isci_task_complete_for_upper_layer(
+				task,
+				SAS_TASK_UNDELIVERED,
+				SAS_DEVICE_UNKNOWN,
+				isci_perform_normal_io_completion
+				);
+			/* We don't have a valid host reference, so we
+			 * can't control the host queueing condition.
+			 */
+			continue;
+		}
+
+		device = isci_dev_from_domain_dev(task->dev);
+
+		isci_host = isci_host_from_sas_ha(task->dev->port->ha);
+
+		/* check if the controller hasn't started or if the device
+		 * is ready but not accepting IO.
+		 */
+		if (device) {
+
+			spin_lock_irqsave(&device->host_quiesce_lock,
+					  quiesce_flags);
+		}
+		/* From this point onward, any process that needs to guarantee
+		 * that there is no kernel I/O being started will have to wait
+		 * for the quiesce spinlock.
+		 */
+
+		if (isci_host_get_state(isci_host) == isci_starting ||
+		    (device && ((isci_remote_device_get_state(device) == isci_ready) ||
+		    (isci_remote_device_get_state(device) == isci_host_quiesce)))) {
+
+			/* Forces a retry from scsi mid layer. */
+			dev_warn(task->dev->port->ha->dev,
+				 "%s: task %p: isci_host->status = %d, "
+				 "device = %p\n",
+				 __func__,
+				 task,
+				 isci_host_get_state(isci_host),
+				 device);
+
+			if (device)
+				dev_dbg(task->dev->port->ha->dev,
+					"%s: device->status = 0x%x\n",
+					__func__,
+					isci_remote_device_get_state(device));
+
+			/* Indicate QUEUE_FULL so that the scsi midlayer
+			 * retries.
+			 */
+			isci_task_complete_for_upper_layer(
+				task,
+				SAS_TASK_COMPLETE,
+				SAS_QUEUE_FULL,
+				isci_perform_normal_io_completion
+				);
+			isci_host_can_dequeue(isci_host, 1);
+		}
+		/* the device is going down... */
+		else if (!device || (isci_ready_for_io != isci_remote_device_get_state(device))) {
+
+			dev_dbg(task->dev->port->ha->dev,
+				"%s: task %p: isci_host->status = %d, "
+				"device = %p\n",
+				__func__,
+				task,
+				isci_host_get_state(isci_host),
+				device);
+
+			if (device)
+				dev_dbg(task->dev->port->ha->dev,
+					"%s: device->status = 0x%x\n",
+					__func__,
+					isci_remote_device_get_state(device));
+
+			/* Indicate SAS_TASK_UNDELIVERED, so that the scsi
+			 * midlayer removes the target.
+			 */
+			isci_task_complete_for_upper_layer(
+				task,
+				SAS_TASK_UNDELIVERED,
+				SAS_DEVICE_UNKNOWN,
+				isci_perform_normal_io_completion
+				);
+			isci_host_can_dequeue(isci_host, 1);
+
+		} else {
+			/* build and send the request. */
+			status = isci_request_execute(isci_host, task, &request,
+						      gfp_flags);
+
+			if (status == SCI_SUCCESS) {
+				spin_lock_irqsave(&task->task_state_lock, flags);
+				task->task_state_flags |= SAS_TASK_AT_INITIATOR;
+				spin_unlock_irqrestore(&task->task_state_lock, flags);
+			} else {
+				/* Indicate QUEUE_FULL so that the scsi
+				 * midlayer retries. if the request
+				 * failed for remote device reasons,
+				 * it gets returned as
+				 * SAS_TASK_UNDELIVERED next time
+				 * through.
+				 */
+				isci_task_complete_for_upper_layer(
+						task,
+						SAS_TASK_COMPLETE,
+						SAS_QUEUE_FULL,
+						isci_perform_normal_io_completion
+						);
+				isci_host_can_dequeue(isci_host, 1);
+			}
+		}
+		if (device) {
+			spin_unlock_irqrestore(&device->host_quiesce_lock,
+					       quiesce_flags
+					       );
+		}
+		task = list_entry(task->list.next, struct sas_task, list);
+	} while (--num > 0);
+	return 0;
+}
+
+
+
+/**
+ * isci_task_request_build() - This function builds the task request object.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @request: This parameter points to the isci_request object allocated in the
+ *    request construct function.
+ * @tmf: This parameter is the task management struct to be built
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+static enum sci_status isci_task_request_build(
+	struct isci_host *isci_host,
+	struct isci_request **isci_request,
+	struct isci_tmf *isci_tmf)
+{
+	struct scic_sds_remote_device *sci_device;
+	enum sci_status status = SCI_FAILURE;
+	struct isci_request *request;
+	struct isci_remote_device *isci_device;
+/*	struct sci_sas_identify_address_frame_protocols dev_protocols; */
+	struct smp_discover_response_protocols dev_protocols;
+
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_tmf = %p\n", __func__, isci_tmf);
+
+	isci_device = isci_tmf->device;
+	sci_device = isci_device->sci_device_handle;
+
+	/* do common allocation and init of request object. */
+	status = isci_request_alloc_tmf(
+		isci_host,
+		isci_tmf,
+		&request,
+		isci_device,
+		GFP_ATOMIC
+		);
+
+	if (status != SCI_SUCCESS)
+		goto out;
+
+	/* let the core do it's construct. */
+	status = scic_task_request_construct(
+		isci_host->core_controller,
+		sci_device,
+		SCI_CONTROLLER_INVALID_IO_TAG,
+		request,
+		request->sci_request_mem_ptr,
+		&request->sci_request_handle
+		);
+
+	if (status != SCI_SUCCESS) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: scic_task_request_construct failed - "
+			 "status = 0x%x\n",
+			 __func__,
+			 status);
+		goto errout;
+	}
+
+	sci_object_set_association(
+		request->sci_request_handle,
+		request
+		);
+
+	scic_remote_device_get_protocols(
+		sci_device,
+		&dev_protocols
+		);
+
+	/* let the core do it's protocol
+	 * specific construction.
+	 */
+	if (dev_protocols.u.bits.attached_ssp_target) {
+
+		isci_tmf->proto = SAS_PROTOCOL_SSP;
+		status = scic_task_request_construct_ssp(
+			request->sci_request_handle
+			);
+		if (status != SCI_SUCCESS)
+			goto errout;
+	}
+
+	if (dev_protocols.u.bits.attached_stp_target) {
+
+		isci_tmf->proto = SAS_PROTOCOL_SATA;
+		status = isci_sata_management_task_request_build(request);
+
+		if (status != SCI_SUCCESS)
+			goto errout;
+	}
+
+	goto out;
+
+ errout:
+
+	/* release the dma memory if we fail. */
+	isci_request_free(isci_host, request);
+	request = NULL;
+
+ out:
+	*isci_request = request;
+	return status;
+}
+
+/**
+ * isci_tmf_timeout_cb() - This function is called as a kernel callback when
+ *    the timeout period for the TMF has expired.
+ *
+ *
+ */
+static void isci_tmf_timeout_cb(void *tmf_request_arg)
+{
+	struct isci_request *request = (struct isci_request *)tmf_request_arg;
+	struct isci_tmf *tmf = isci_request_access_tmf(request);
+	enum sci_status status;
+
+	BUG_ON(request->ttype != tmf_task);
+
+	/* This task management request has timed-out.  Terminate the request
+	 * so that the request eventually completes to the requestor in the
+	 * request completion callback path.
+	 */
+	/* Note - the timer callback function itself has provided spinlock
+	 * exclusion from the start and completion paths.  No need to take
+	 * the request->isci_host->scic_lock here.
+	 */
+
+	if (tmf->timeout_timer != NULL) {
+		/* Call the users callback, if any. */
+		if (tmf->cb_state_func != NULL)
+			tmf->cb_state_func(isci_tmf_timed_out, tmf,
+					   tmf->cb_data);
+
+		/* Terminate the TMF transmit request. */
+		status = scic_controller_terminate_request(
+			request->isci_host->core_controller,
+			request->isci_device->sci_device_handle,
+			request->sci_request_handle
+			);
+
+		dev_dbg(&request->isci_host->pdev->dev,
+			"%s: tmf_request = %p; tmf = %p; status = %d\n",
+			__func__, request, tmf, status);
+	} else
+		dev_dbg(&request->isci_host->pdev->dev,
+			"%s: timer already canceled! "
+			"tmf_request = %p; tmf = %p\n",
+			__func__, request, tmf);
+
+	/* No need to unlock since the caller to this callback is doing it for
+	 * us.
+	 * request->isci_host->scic_lock
+	 */
+}
+
+/**
+ * isci_task_execute_tmf() - This function builds and sends a task request,
+ *    then waits for the completion.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @tmf: This parameter is the pointer to the task management structure for
+ *    this request.
+ * @timeout_ms: This parameter specifies the timeout period for the task
+ *    management request.
+ *
+ * TMF_RESP_FUNC_COMPLETE on successful completion of the TMF (this includes
+ * error conditions reported in the IU status), or TMF_RESP_FUNC_FAILED.
+ */
+int isci_task_execute_tmf(
+	struct isci_host *isci_host,
+	struct isci_tmf *tmf,
+	unsigned long timeout_ms)
+{
+	DECLARE_COMPLETION_ONSTACK(completion);
+	enum sci_status status = SCI_FAILURE;
+	struct scic_sds_remote_device *sci_device;
+	struct isci_remote_device *isci_device = tmf->device;
+	struct isci_request *request;
+	int ret = TMF_RESP_FUNC_FAILED;
+	unsigned long flags;
+
+	/* sanity check, return TMF_RESP_FUNC_FAILED
+	 * if the device is not there and ready.
+	 */
+	if (!isci_device ||
+	    ((isci_ready_for_io != isci_remote_device_get_state(isci_device)) &&
+	    (isci_host_quiesce != isci_remote_device_get_state(isci_device)))) {
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: isci_device = %p not ready (%d)\n",
+			__func__,
+			isci_device,
+			isci_remote_device_get_state(isci_device));
+		return TMF_RESP_FUNC_FAILED;
+	} else
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: isci_device = %p\n",
+			__func__, isci_device);
+
+	sci_device = isci_device->sci_device_handle;
+
+	/* Assign the pointer to the TMF's completion kernel wait structure. */
+	tmf->complete = &completion;
+
+	isci_task_request_build(
+		isci_host,
+		&request,
+		tmf
+		);
+
+	if (!request) {
+		dev_warn(&isci_host->pdev->dev,
+			"%s: isci_task_request_build failed\n",
+			__func__);
+		return TMF_RESP_FUNC_FAILED;
+	}
+
+	/* Allocate the TMF timeout timer. */
+	tmf->timeout_timer = isci_timer_create(
+		&isci_host->timer_list_struct,
+		isci_host,
+		request,
+		isci_tmf_timeout_cb
+		);
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	/* Start the timer. */
+	if (tmf->timeout_timer)
+		isci_timer_start(tmf->timeout_timer, timeout_ms);
+	else
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: isci_timer_create failed!!!!\n",
+			 __func__);
+
+	/* start the TMF io. */
+	status = scic_controller_start_task(
+		isci_host->core_controller,
+		sci_device,
+		request->sci_request_handle,
+		SCI_CONTROLLER_INVALID_IO_TAG
+		);
+
+	if (status != SCI_SUCCESS) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: start_io failed - status = 0x%x, request = %p\n",
+			 __func__,
+			 status,
+			 request);
+		goto cleanup_request;
+	}
+
+	/* Call the users callback, if any. */
+	if (tmf->cb_state_func != NULL)
+		tmf->cb_state_func(isci_tmf_started, tmf, tmf->cb_data);
+
+	/* Change the state of the TMF-bearing request to "started". */
+	isci_request_change_state(request, started);
+
+	/* add the request to the remote device request list. */
+	list_add(&request->dev_node, &isci_device->reqs_in_process);
+
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	/* Wait for the TMF to complete, or a timeout. */
+	wait_for_completion(&completion);
+
+	isci_print_tmf(tmf);
+
+	if (tmf->status == SCI_SUCCESS)
+		ret =  TMF_RESP_FUNC_COMPLETE;
+	else if (tmf->status == SCI_FAILURE_IO_RESPONSE_VALID) {
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: tmf.status == "
+			"SCI_FAILURE_IO_RESPONSE_VALID\n",
+			__func__);
+		ret =  TMF_RESP_FUNC_COMPLETE;
+	}
+	/* Else - leave the default "failed" status alone. */
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: completed request = %p\n",
+		__func__,
+		request);
+
+	if (request->io_request_completion != NULL) {
+
+		/* The fact that this is non-NULL for a TMF request
+		 * means there is a thread waiting for this TMF to
+		 * finish.
+		 */
+		complete(request->io_request_completion);
+	}
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+ cleanup_request:
+
+	/* Clean up the timer if needed. */
+	if (tmf->timeout_timer) {
+		isci_timer_stop(tmf->timeout_timer);
+		isci_timer_free(&isci_host->timer_list_struct,
+				tmf->timeout_timer);
+		tmf->timeout_timer = NULL;
+	}
+
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	isci_request_free(isci_host, request);
+
+	return ret;
+}
+
+void isci_task_build_tmf(
+	struct isci_tmf *tmf,
+	struct isci_remote_device *isci_device,
+	enum isci_tmf_function_codes code,
+	void (*tmf_sent_cb)(enum isci_tmf_cb_state,
+			    struct isci_tmf *,
+			    void *),
+	void *cb_data)
+{
+	dev_dbg(&isci_device->isci_port->isci_host->pdev->dev,
+		"%s: isci_device = %p\n", __func__, isci_device);
+
+	memset(tmf, 0, sizeof(*tmf));
+
+	tmf->device        = isci_device;
+	tmf->tmf_code      = code;
+	tmf->timeout_timer = NULL;
+	tmf->cb_state_func = tmf_sent_cb;
+	tmf->cb_data       = cb_data;
+}
+
+static struct isci_request *isci_task_get_request_from_task(
+	struct sas_task *task,
+	struct isci_host **isci_host,
+	struct isci_remote_device **isci_device)
+{
+
+	struct isci_request *request = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&task->task_state_lock, flags);
+
+	request = task->lldd_task;
+
+	/* If task is already done, the request isn't valid */
+	if (!(task->task_state_flags & SAS_TASK_STATE_DONE) &&
+	    (task->task_state_flags & SAS_TASK_AT_INITIATOR) &&
+	    (request != NULL)) {
+
+		if (isci_host != NULL)
+			*isci_host = request->isci_host;
+
+		if (isci_device != NULL)
+			*isci_device = request->isci_device;
+	}
+
+	spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+	return request;
+}
+
+/**
+ * isci_task_validate_request_to_abort() - This function checks the given I/O
+ *    against the "started" state.  If the request is still "started", it's
+ *    state is changed to aborted. NOTE: isci_host->scic_lock MUST BE HELD
+ *    BEFORE CALLING THIS FUNCTION.
+ * @isci_request: This parameter specifies the request object to control.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @isci_device: This is the device to which the request is pending.
+ * @aborted_io_completion: This is a completion structure that will be added to
+ *    the request in case it is changed to aborting; this completion is
+ *    triggered when the request is fully completed.
+ *
+ * Either "started" on successful change of the task status to "aborted", or
+ * "unallocated" if the task cannot be controlled.
+ */
+static enum isci_request_status isci_task_validate_request_to_abort(
+	struct isci_request *isci_request,
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	struct completion *aborted_io_completion)
+{
+	enum isci_request_status old_state = unallocated;
+
+	/* Only abort the task if it's in the
+	 *  device's request_in_process list
+	 */
+	if (isci_request && !list_empty(&isci_request->dev_node)) {
+		old_state = isci_request_change_started_to_aborted(
+			isci_request, aborted_io_completion);
+
+		/* Only abort requests in the started state. */
+		if (old_state != started)
+			old_state = unallocated;
+	}
+
+	return old_state;
+}
+
+static void isci_request_cleanup_completed_loiterer(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	struct isci_request *isci_request)
+{
+	struct sas_task *task = isci_request_access_task(isci_request);
+	unsigned long flags;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device=%p, request=%p, task=%p\n",
+		__func__, isci_device, isci_request,
+		isci_request->ttype_ptr.io_task_ptr);
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+	list_del_init(&isci_request->dev_node);
+	if (task != NULL)
+		task->lldd_task = NULL;
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	isci_request_free(isci_host, isci_request);
+}
+/**
+ * isci_terminate_request_core() - This function will terminate the given
+ *    request, and wait for it to complete.  This function must only be called
+ *    from a thread that can wait.  Note that the request is terminated and
+ *    completed (back to the host, if started there).
+ * @isci_host: This SCU.
+ * @isci_device: The target.
+ * @isci_request: The I/O request to be terminated.
+ *
+ *
+ */
+static void isci_terminate_request_core(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	struct isci_request *isci_request,
+	struct completion *request_completion)
+{
+	enum sci_status status                 = SCI_SUCCESS;
+	bool was_terminated         = false;
+	bool needs_cleanup_handling = false;
+	enum isci_request_status request_status;
+	unsigned long flags;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: device = %p; request = %p\n",
+		__func__, isci_device, isci_request);
+
+	/* Peek at the current status of the request.  This will tell
+	 * us if there was special handling on the request such that it
+	 * needs to be detached and freed here.
+	 */
+	spin_lock_irqsave(&isci_request->state_lock, flags);
+	request_status = isci_request_get_state(isci_request);
+
+	/* TMFs are in their own thread */
+	if ((isci_request->ttype == io_task) &&
+	    ((request_status == aborted) ||
+	     (request_status == aborting) ||
+	     (request_status == terminating)))
+		/* The completion routine won't free a request in
+		 * the aborted/aborting/terminating state, so we do
+		 * it here.
+		 */
+		needs_cleanup_handling = true;
+
+	spin_unlock_irqrestore(&isci_request->state_lock, flags);
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+	/* Make sure the request wasn't just sitting around signalling
+	 * device condition (if the request handle is NULL, then the
+	 * request completed but needed additional handling here).
+	 */
+	if (isci_request->sci_request_handle != NULL) {
+		was_terminated = true;
+		status = scic_controller_terminate_request(
+			isci_host->core_controller,
+			isci_device->sci_device_handle,
+			isci_request->sci_request_handle
+			);
+	}
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	/*
+	 * The only time the request to terminate will
+	 * fail is when the io request is completed and
+	 * being aborted.
+	 */
+	if (status != SCI_SUCCESS)
+		dev_err(&isci_host->pdev->dev,
+			"%s: scic_controller_terminate_request"
+			" returned = 0x%x\n",
+			__func__,
+			status);
+	else {
+		if (was_terminated) {
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: before completion wait (%p)\n",
+				__func__,
+				request_completion);
+
+			/* Wait here for the request to complete. */
+			wait_for_completion(request_completion);
+
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: after completion wait (%p)\n",
+				__func__,
+				request_completion);
+		}
+
+		if (needs_cleanup_handling)
+			isci_request_cleanup_completed_loiterer(
+				isci_host, isci_device, isci_request
+				);
+	}
+}
+static void isci_terminate_request(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	struct isci_request *isci_request,
+	enum isci_request_status new_request_state)
+{
+	enum isci_request_status old_state;
+
+	DECLARE_COMPLETION_ONSTACK(request_completion);
+	unsigned long flags;
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	/* Change state to "new_request_state" if it is currently "started" */
+	old_state = isci_request_change_started_to_newstate(
+		isci_request,
+		&request_completion,
+		new_request_state
+		);
+
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	if (old_state == started)
+		/* This request was not already being aborted. If it had been,
+		 * then the aborting I/O (ie. the TMF request) would not be in
+		 * the aborting state, and thus would be terminated here.  Note
+		 * that since the TMF completion's call to the kernel function
+		 * "complete()" does not happen until the pending I/O request
+		 * terminate fully completes, we do not have to implement a
+		 * special wait here for already aborting requests - the
+		 * termination of the TMF request will force the request
+		 * to finish it's already started terminate.
+		 */
+		isci_terminate_request_core(isci_host, isci_device,
+					    isci_request, &request_completion);
+}
+
+/**
+ * isci_terminate_pending_requests() - This function will change the all of the
+ *    requests on the given device's state to "aborting", will terminate the
+ *    requests, and wait for them to complete.  This function must only be
+ *    called from a thread that can wait.  Note that the requests are all
+ *    terminated and completed (back to the host, if started there).
+ * @isci_host: This parameter specifies SCU.
+ * @isci_device: This parameter specifies the target.
+ *
+ *
+ */
+void isci_terminate_pending_requests(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	enum isci_request_status new_request_state)
+{
+	struct isci_request *isci_request;
+	struct sas_task *task;
+	bool done = false;
+	unsigned long flags;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device = %p (new request state = %d)\n",
+		__func__, isci_device, new_request_state);
+
+	#define ISCI_TERMINATE_SHOW_PENDING_REQUESTS
+	#ifdef ISCI_TERMINATE_SHOW_PENDING_REQUESTS
+	{
+		struct isci_request *request;
+
+		/* Only abort the task if it's in the
+		 * device's request_in_process list
+		 */
+		list_for_each_entry(request,
+				    &isci_device->reqs_in_process,
+				    dev_node)
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: isci_device = %p; request is on "
+				"reqs_in_process list: %p\n",
+				__func__, isci_device, request);
+	}
+	#endif /* ISCI_TERMINATE_SHOW_PENDING_REQUESTS */
+
+	/* Clean up all pending requests. */
+	do {
+		spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+		if (list_empty(&isci_device->reqs_in_process)) {
+
+			done = true;
+			spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: isci_device = %p; done.\n",
+				__func__, isci_device);
+		} else {
+			/* The list was not empty - grab the first request. */
+			isci_request = list_first_entry(
+				&isci_device->reqs_in_process,
+				struct isci_request, dev_node
+				);
+			/* Note that we are not expecting to have to control
+			 * the target to abort the request.
+			 */
+			isci_request->complete_in_target = true;
+
+			spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+			/* Get the libsas task reference. */
+			task = isci_request_access_task(isci_request);
+
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: isci_device=%p request=%p; task=%p\n",
+				__func__, isci_device, isci_request, task);
+
+			/* Mark all still pending I/O with the selected next
+			 * state.
+			 */
+			isci_terminate_request(isci_host, isci_device,
+					       isci_request, new_request_state
+					       );
+
+			/* Set the 'done' state on the task. */
+			if (task)
+				isci_task_all_done(task);
+		}
+	} while (!done);
+}
+
+/**
+ * isci_task_send_lu_reset_sas() - This function is called by of the SAS Domain
+ *    Template functions.
+ * @lun: This parameter specifies the lun to be reset.
+ *
+ * status, zero indicates success.
+ */
+static int isci_task_send_lu_reset_sas(
+	struct isci_host *isci_host,
+	struct isci_remote_device *isci_device,
+	u8 *lun)
+{
+	struct isci_tmf tmf;
+	int ret = TMF_RESP_FUNC_FAILED;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_host = %p, isci_device = %p\n",
+		__func__, isci_host, isci_device);
+	/* Send the LUN reset to the target.  By the time the call returns,
+	 * the TMF has fully exected in the target (in which case the return
+	 * value is "TMF_RESP_FUNC_COMPLETE", or the request timed-out (or
+	 * was otherwise unable to be executed ("TMF_RESP_FUNC_FAILED").
+	 */
+	isci_task_build_tmf(&tmf, isci_device, isci_tmf_ssp_lun_reset, NULL,
+			    NULL);
+
+	#define ISCI_LU_RESET_TIMEOUT_MS 2000 /* 2 second timeout. */
+	ret = isci_task_execute_tmf(isci_host, &tmf, ISCI_LU_RESET_TIMEOUT_MS);
+
+	if (ret == TMF_RESP_FUNC_COMPLETE)
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: %p: TMF_LU_RESET passed\n",
+			__func__, isci_device);
+	else
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: %p: TMF_LU_RESET failed (%x)\n",
+			__func__, isci_device, ret);
+
+	return ret;
+}
+
+/**
+ * isci_task_lu_reset() - This function is one of the SAS Domain Template
+ *    functions. This is one of the Task Management functoins called by libsas,
+ *    to reset the given lun. Note the assumption that while this call is
+ *    executing, no I/O will be sent by the host to the device.
+ * @lun: This parameter specifies the lun to be reset.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_lu_reset(
+	struct domain_device *domain_device,
+	u8 *lun)
+{
+	struct isci_host *isci_host = NULL;
+	struct isci_remote_device *isci_device = NULL;
+	int ret;
+	bool device_stopping = false;
+
+	if (domain_device == NULL) {
+		pr_warn("%s: domain_device == NULL\n", __func__);
+		return TMF_RESP_FUNC_FAILED;
+	}
+
+	isci_device = isci_dev_from_domain_dev(domain_device);
+
+	if (domain_device->port != NULL)
+		isci_host = isci_host_from_sas_ha(domain_device->port->ha);
+
+	pr_debug("%s: domain_device=%p, isci_host=%p; isci_device=%p\n",
+		 __func__, domain_device, isci_host, isci_device);
+
+	if (isci_device != NULL)
+		device_stopping = (isci_device->status == isci_stopping)
+				  || (isci_device->status == isci_stopped);
+
+	/* If there is a device reset pending on any request in the
+	 * device's list, fail this LUN reset request in order to
+	 * escalate to the device reset.
+	 */
+	if ((isci_device == NULL) ||
+	    (isci_host == NULL) ||
+	    ((isci_host != NULL) &&
+	     (isci_device != NULL) &&
+	     (device_stopping ||
+	      (isci_device_is_reset_pending(isci_host, isci_device))))) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: No dev (%p), no host (%p), or "
+			 "RESET PENDING: domain_device=%p\n",
+			 __func__, isci_device, isci_host, domain_device);
+		return TMF_RESP_FUNC_FAILED;
+	}
+
+	/* Stop I/O to the remote device. */
+	isci_device_set_host_quiesce_lock_state(isci_device, true);
+
+	/* Send the task management part of the reset. */
+	if (sas_protocol_ata(domain_device->tproto)) {
+		ret = isci_task_send_lu_reset_sata(
+			isci_host, isci_device, lun
+			);
+	} else
+		ret = isci_task_send_lu_reset_sas(isci_host, isci_device, lun);
+
+	/* If the LUN reset worked, all the I/O can now be terminated. */
+	if (ret == TMF_RESP_FUNC_COMPLETE)
+		/* Terminate all I/O now. */
+		isci_terminate_pending_requests(isci_host,
+						isci_device,
+						terminating);
+
+	/* Resume I/O to the remote device. */
+	isci_device_set_host_quiesce_lock_state(isci_device, false);
+
+	return ret;
+}
+
+
+/*	 int (*lldd_clear_nexus_port)(struct asd_sas_port *); */
+int isci_task_clear_nexus_port(struct asd_sas_port *port)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+
+
+int isci_task_clear_nexus_ha(struct sas_ha_struct *ha)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+int isci_task_I_T_nexus_reset(struct domain_device *dev)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+
+/* Task Management Functions. Must be called from process context.	 */
+
+/**
+ * isci_abort_task_process_cb() - This is a helper function for the abort task
+ *    TMF command.  It manages the request state with respect to the successful
+ *    transmission / completion of the abort task request.
+ * @cb_state: This parameter specifies when this function was called - after
+ *    the TMF request has been started and after it has timed-out.
+ * @tmf: This parameter specifies the TMF in progress.
+ *
+ *
+ */
+static void isci_abort_task_process_cb(
+	enum isci_tmf_cb_state cb_state,
+	struct isci_tmf *tmf,
+	void *cb_data)
+{
+	struct isci_request *old_request;
+
+	old_request = (struct isci_request *)cb_data;
+
+	dev_dbg(&old_request->isci_host->pdev->dev,
+		"%s: tmf=%p, old_request=%p\n",
+		__func__, tmf, old_request);
+
+	switch (cb_state) {
+
+	case isci_tmf_started:
+		/* The TMF has been started.  Nothing to do here, since the
+		 * request state was already set to "aborted" by the abort
+		 * task function.
+		 */
+		BUG_ON(old_request->status != aborted);
+		break;
+
+	case isci_tmf_timed_out:
+
+		/* Set the task's state to "aborting", since the abort task
+		 * function thread set it to "aborted" (above) in anticipation
+		 * of the task management request working correctly.  Since the
+		 * timeout has now fired, the TMF request failed.  We set the
+		 * state such that the request completion will indicate the
+		 * device is no longer present.
+		 */
+		isci_request_change_state(old_request, aborting);
+		break;
+
+	default:
+		dev_err(&old_request->isci_host->pdev->dev,
+			"%s: Bad cb_state (%d): tmf=%p, old_request=%p\n",
+			__func__, cb_state, tmf, old_request);
+		break;
+	}
+}
+
+/**
+ * isci_task_abort_task() - This function is one of the SAS Domain Template
+ *    functions. This function is called by libsas to abort a specified task.
+ * @task: This parameter specifies the SAS task to abort.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_abort_task(struct sas_task *task)
+{
+	DECLARE_COMPLETION_ONSTACK(aborted_io_completion);
+	struct isci_request *old_request = NULL;
+	struct isci_remote_device *isci_device = NULL;
+	struct isci_host *isci_host = NULL;
+	struct isci_tmf tmf;
+	int ret = TMF_RESP_FUNC_FAILED;
+	unsigned long flags;
+	bool any_dev_reset, device_stopping;
+
+	/* Get the isci_request reference from the task.  Note that
+	 * this check does not depend on the pending request list
+	 * in the device, because tasks driving resets may land here
+	 * after completion in the core.
+	 */
+	old_request = isci_task_get_request_from_task(task, &isci_host,
+						      &isci_device);
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: task = %p\n", __func__, task);
+
+	/* Check if the device has been / is currently being removed.
+	 * If so, no task management will be done, and the I/O will
+	 * be terminated.
+	 */
+	device_stopping = (isci_device->status == isci_stopping)
+			  || (isci_device->status == isci_stopped);
+
+#ifdef NOMORE
+	/* This abort task function is the first stop of the libsas error
+	 * handler thread. Since libsas is executing in a thread with a
+	 * referernce to the "task" parameter, that task cannot be completed
+	 * directly back to the upper layers.  In order to make sure that
+	 * the task is managed correctly if this abort task fails, set the
+	 * "SAS_TASK_STATE_ABORTED" bit now such that completions up the
+	 * stack will be intercepted and only allowed to happen in the
+	 * libsas SCSI error handler thread.
+	 */
+	spin_lock_irqsave(&task->task_state_lock, flags);
+	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
+	spin_unlock_irqrestore(&task->task_state_lock, flags);
+#endif  /* NOMORE */
+
+	/* This version of the driver will fail abort requests for
+	 * SATA/STP.  Failing the abort request this way will cause the
+	 * SCSI error handler thread to escalate to LUN reset
+	 */
+	if (sas_protocol_ata(task->task_proto) && !device_stopping) {
+		dev_warn(&isci_host->pdev->dev,
+			    " task %p is for a STP/SATA device;"
+			    " returning TMF_RESP_FUNC_FAILED\n"
+			    " to cause a LUN reset...\n", task);
+		return TMF_RESP_FUNC_FAILED;
+	}
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: old_request == %p\n", __func__, old_request);
+
+	spin_lock_irqsave(&task->task_state_lock, flags);
+
+	/* Don't do resets to stopping devices. */
+	if (device_stopping)
+		task->task_state_flags &= ~SAS_TASK_NEED_DEV_RESET;
+
+	/* See if there is a pending device reset for this device. */
+	any_dev_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
+
+	spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+	if ((isci_device != NULL) && !device_stopping)
+		any_dev_reset = any_dev_reset
+				|| isci_device_is_reset_pending(isci_host,
+								isci_device
+								);
+
+	/* If the extraction of the request reference from the task
+	 * failed, then the request has been completed (or if there is a
+	 * pending reset then this abort request function must be failed
+	 * in order to escalate to the target reset).
+	 */
+	if ((old_request == NULL) ||
+	    ((old_request != NULL) &&
+	     (old_request->sci_request_handle == NULL) &&
+	     (old_request->complete_in_target)) ||
+	     any_dev_reset) {
+
+		spin_lock_irqsave(&task->task_state_lock, flags);
+
+		/* If the device reset task flag is set, fail the task
+		 * management request.  Otherwise, the original request
+		 * has completed.
+		 */
+		if (any_dev_reset) {
+
+			/* Turn off the task's DONE to make sure this
+			 * task is escalated to a target reset.
+			 */
+			task->task_state_flags &= ~SAS_TASK_STATE_DONE;
+
+			/* Fail the task management request in order to
+			 * escalate to the target reset.
+			 */
+			ret = TMF_RESP_FUNC_FAILED;
+
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: Failing task abort in order to "
+				"escalate to target reset because\n"
+				"SAS_TASK_NEED_DEV_RESET is set for "
+				"task %p on dev %p\n",
+				__func__, task, isci_device);
+
+		} else {
+			ret = TMF_RESP_FUNC_COMPLETE;
+
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: abort task not needed for %p\n",
+				__func__, task);
+
+			/* The request has already completed and there
+			 * is nothing to do here other than to set the task
+			 * done bit, and indicate that the task abort function
+			 * was sucessful.
+			 */
+			isci_set_task_doneflags(task);
+
+			/* Set the abort bit to make sure that libsas sticks the
+			 * task in the completed task queue.
+			 */
+/*			task->task_state_flags |= SAS_TASK_STATE_ABORTED; */
+
+			/* Check for the situation where the request was
+			 * left around on the device list but the
+			 * request already completed.
+			 */
+			if (old_request && !old_request->sci_request_handle) {
+
+				isci_request_cleanup_completed_loiterer(
+					isci_host, isci_device, old_request
+					);
+			}
+		}
+		spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+		return ret;
+	}
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	/* Sanity check the request status, and set the I/O kernel completion
+	 * struct that will be triggered when the request completes.
+	 */
+	if (isci_task_validate_request_to_abort(
+		    old_request,
+		    isci_host,
+		    isci_device,
+		    &aborted_io_completion)
+	    == unallocated) {
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: old_request not valid for device = %p\n",
+			__func__,
+			isci_device);
+		old_request = NULL;
+	}
+
+	if (!old_request) {
+
+		/* There is no isci_request attached to the sas_task.
+		 * It must have been completed and detached.
+		 */
+		dev_dbg(&isci_host->pdev->dev,
+			"%s: old_request == NULL\n",
+			__func__);
+
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+		/* Set the state on the task. */
+		isci_task_all_done(task);
+
+		return TMF_RESP_FUNC_COMPLETE;
+	}
+	if (task->task_proto == SAS_PROTOCOL_SMP || device_stopping) {
+
+		if (device_stopping)
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: device is stopping, thus no TMF\n",
+				__func__);
+		else
+			dev_dbg(&isci_host->pdev->dev,
+				"%s: request is SMP, thus no TMF\n",
+				__func__);
+
+		old_request->complete_in_target = true;
+
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+		/* Set the state on the task. */
+		isci_task_all_done(task);
+
+		ret = TMF_RESP_FUNC_COMPLETE;
+
+		/* Stopping and SMP devices are not sent a TMF, and are not
+		 * reset, but the outstanding I/O request is terminated here.
+		 *
+		 * Clean up the request on our side, and wait for the aborted
+		 * I/O to complete.
+		 */
+		isci_terminate_request_core(isci_host, isci_device, old_request,
+					    &aborted_io_completion);
+	} else {
+		/* Fill in the tmf stucture */
+		isci_task_build_tmf(&tmf, isci_device, isci_tmf_ssp_task_abort,
+				    isci_abort_task_process_cb, old_request);
+
+		tmf.io_tag = scic_io_request_get_io_tag(
+			old_request->sci_request_handle
+			);
+
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+		#define ISCI_ABORT_TASK_TIMEOUT_MS 500 /* half second timeout. */
+		ret = isci_task_execute_tmf(isci_host, &tmf,
+					    ISCI_ABORT_TASK_TIMEOUT_MS);
+
+		if (ret == TMF_RESP_FUNC_COMPLETE) {
+			old_request->complete_in_target = true;
+
+			/* Clean up the request on our side, and wait for the aborted I/O to
+			 * complete.
+			 */
+			isci_terminate_request_core(isci_host, isci_device, old_request,
+						    &aborted_io_completion);
+
+			/* Set the state on the task. */
+			isci_task_all_done(task);
+		} else
+			dev_err(&isci_host->pdev->dev,
+				"%s: isci_task_send_tmf failed\n",
+				__func__);
+	}
+
+	return ret;
+}
+
+/**
+ * isci_task_abort_task_set() - This function is one of the SAS Domain Template
+ *    functions. This is one of the Task Management functoins called by libsas,
+ *    to abort all task for the given lun.
+ * @d_device: This parameter specifies the domain device associated with this
+ *    request.
+ * @lun: This parameter specifies the lun associated with this request.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_abort_task_set(
+	struct domain_device *d_device,
+	u8 *lun)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+
+/**
+ * isci_task_clear_aca() - This function is one of the SAS Domain Template
+ *    functions. This is one of the Task Management functoins called by libsas.
+ * @d_device: This parameter specifies the domain device associated with this
+ *    request.
+ * @lun: This parameter specifies the lun	 associated with this request.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_clear_aca(
+	struct domain_device *d_device,
+	u8 *lun)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+
+
+/**
+ * isci_task_clear_task_set() - This function is one of the SAS Domain Template
+ *    functions. This is one of the Task Management functoins called by libsas.
+ * @d_device: This parameter specifies the domain device associated with this
+ *    request.
+ * @lun: This parameter specifies the lun	 associated with this request.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_clear_task_set(
+	struct domain_device *d_device,
+	u8 *lun)
+{
+	return TMF_RESP_FUNC_FAILED;
+}
+
+
+/**
+ * isci_task_query_task() - This function is implemented to cause libsas to
+ *    correctly escalate the failed abort to a LUN or target reset (this is
+ *    because sas_scsi_find_task libsas function does not correctly interpret
+ *    all return codes from the abort task call).  When TMF_RESP_FUNC_SUCC is
+ *    returned, libsas turns this into a LUN reset; when FUNC_FAILED is
+ *    returned, libsas will turn this into a target reset
+ * @task: This parameter specifies the sas task being queried.
+ * @lun: This parameter specifies the lun associated with this request.
+ *
+ * status, zero indicates success.
+ */
+int isci_task_query_task(
+	struct sas_task *task)
+{
+	/* See if there is a pending device reset for this device. */
+	if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET)
+		return TMF_RESP_FUNC_FAILED;
+	else
+		return TMF_RESP_FUNC_SUCC;
+}
+
+/**
+ * isci_task_request_complete() - This function is called by the sci core when
+ *    an task request completes.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @request: This parameter is the completed isci_request object.
+ * @completion_status: This parameter specifies the completion status from the
+ *    sci core.
+ *
+ * none.
+ */
+void isci_task_request_complete(
+	struct isci_host *isci_host,
+	struct isci_request *request,
+	enum sci_task_status completion_status)
+{
+	struct isci_remote_device *isci_device = request->isci_device;
+	enum isci_request_status old_state;
+	struct isci_tmf *tmf = isci_request_access_tmf(request);
+	struct completion *tmf_complete;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: request = %p, status=%d\n",
+		__func__, request, completion_status);
+
+	old_state = isci_request_change_state(request, completed);
+
+	tmf->status = completion_status;
+	request->complete_in_target = true;
+
+	if (SAS_PROTOCOL_SSP == tmf->proto) {
+
+		memcpy(&tmf->resp.resp_iu,
+		       scic_io_request_get_response_iu_address(
+			       request->sci_request_handle
+			       ),
+		       sizeof(struct sci_ssp_response_iu));
+
+	} else if (SAS_PROTOCOL_SATA == tmf->proto) {
+
+		memcpy(&tmf->resp.d2h_fis,
+		       scic_stp_io_request_get_d2h_reg_address(
+			       request->sci_request_handle
+			       ),
+		       sizeof(struct sata_fis_reg_d2h)
+		       );
+	}
+
+	/* Manage the timer if it is still running. */
+	if (tmf->timeout_timer) {
+
+		isci_timer_stop(tmf->timeout_timer);
+		isci_timer_free(&isci_host->timer_list_struct,
+				tmf->timeout_timer);
+		tmf->timeout_timer = NULL;
+	}
+
+	/* PRINT_TMF( ((struct isci_tmf *)request->task)); */
+	tmf_complete = tmf->complete;
+
+	scic_controller_complete_task(
+		isci_host->core_controller,
+		isci_device->sci_device_handle,
+		request->sci_request_handle
+		);
+	/* NULL the request handle to make sure it cannot be terminated
+	 *  or completed again.
+	 */
+	request->sci_request_handle = NULL;
+
+	isci_request_change_state(request, unallocated);
+	list_del_init(&request->dev_node);
+
+	/* The task management part completes last. */
+	complete(tmf_complete);
+}
+
+
+/**
+ * isci_task_ssp_request_get_lun() - This function is called by the sci core to
+ *    retrieve the lun for a given task request.
+ * @request: This parameter is the isci_request object.
+ *
+ * lun for specified task request.
+ */
+u32 isci_task_ssp_request_get_lun(struct isci_request *request)
+{
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(request);
+
+	dev_dbg(&request->isci_host->pdev->dev,
+		"%s: lun = %d\n", __func__, isci_tmf->lun[0]);
+/* @todo: build lun from array of bytes to 32 bit */
+	return isci_tmf->lun[0];
+}
+
+/**
+ * isci_task_ssp_request_get_function() - This function is called by the sci
+ *    core to retrieve the function for a given task request.
+ * @request: This parameter is the isci_request object.
+ *
+ * function code for specified task request.
+ */
+u8 isci_task_ssp_request_get_function(struct isci_request *request)
+{
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(request);
+
+	dev_dbg(&request->isci_host->pdev->dev,
+		"%s: func = %d\n", __func__, isci_tmf->tmf_code);
+
+	return isci_tmf->tmf_code;
+}
+
+/**
+ * isci_task_ssp_request_get_io_tag_to_manage() - This function is called by
+ *    the sci core to retrieve the io tag for a given task request.
+ * @request: This parameter is the isci_request object.
+ *
+ * io tag for specified task request.
+ */
+u16 isci_task_ssp_request_get_io_tag_to_manage(struct isci_request *request)
+{
+	u16 io_tag = SCI_CONTROLLER_INVALID_IO_TAG;
+
+	if (tmf_task == request->ttype) {
+		struct isci_tmf *tmf = isci_request_access_tmf(request);
+		io_tag = tmf->io_tag;
+	}
+
+	dev_dbg(&request->isci_host->pdev->dev,
+		"%s: request = %p, io_tag = %d\n",
+		__func__, request, io_tag);
+
+	return io_tag;
+}
+
+/**
+ * isci_task_ssp_request_get_response_data_address() - This function is called
+ *    by the sci core to retrieve the response data address for a given task
+ *    request.
+ * @request: This parameter is the isci_request object.
+ *
+ * response data address for specified task request.
+ */
+void *isci_task_ssp_request_get_response_data_address(
+	struct isci_request *request)
+{
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(request);
+
+	return &isci_tmf->resp.resp_iu;
+}
+
+/**
+ * isci_task_ssp_request_get_response_data_length() - This function is called
+ *    by the sci core to retrieve the response data length for a given task
+ *    request.
+ * @request: This parameter is the isci_request object.
+ *
+ * response data length for specified task request.
+ */
+u32 isci_task_ssp_request_get_response_data_length(
+	struct isci_request *request)
+{
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(request);
+
+	return sizeof(isci_tmf->resp.resp_iu);
+}
+
+/**
+ * isci_bus_reset_handler() - This function performs a target reset of the
+ *    device referenced by "cmd'.  This function is exported through the
+ *    "struct scsi_host_template" structure such that it is called when an I/O
+ *    recovery process has escalated to a target reset. Note that this function
+ *    is called from the scsi error handler event thread, so may block on calls.
+ * @scsi_cmd: This parameter specifies the target to be reset.
+ *
+ * SUCCESS if the reset process was successful, else FAILED.
+ */
+int isci_bus_reset_handler(struct scsi_cmnd *cmd)
+{
+	unsigned long flags = 0;
+	struct isci_host *isci_host = NULL;
+	enum sci_status status;
+	int base_status;
+	struct isci_remote_device *isci_dev
+		= isci_dev_from_domain_dev(
+		sdev_to_domain_dev(cmd->device));
+
+	dev_dbg(&cmd->device->sdev_gendev,
+		"%s: cmd %p, isci_dev %p\n",
+		__func__, cmd, isci_dev);
+
+	if (!isci_dev) {
+		dev_warn(&cmd->device->sdev_gendev,
+			 "%s: isci_dev is GONE!\n",
+			 __func__);
+
+		return TMF_RESP_FUNC_COMPLETE; /* Nothing to reset. */
+	}
+
+	if (isci_dev->isci_port != NULL)
+		isci_host = isci_dev->isci_port->isci_host;
+
+	if (isci_host != NULL)
+		spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	status = scic_remote_device_reset(isci_dev->sci_device_handle);
+	if (status != SCI_SUCCESS) {
+
+		if (isci_host != NULL)
+			spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+		scmd_printk(KERN_WARNING, cmd,
+			    "%s: scic_remote_device_reset(%p) returned %d!\n",
+			    __func__, isci_dev, status);
+
+		return TMF_RESP_FUNC_FAILED;
+	}
+	if (isci_host != NULL)
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	/* Stop I/O to the remote device. */
+	isci_device_set_host_quiesce_lock_state(isci_dev, true);
+
+	/* Make sure all pending requests are able to be fully terminated. */
+	isci_device_clear_reset_pending(isci_dev);
+
+	/* Terminate in-progress I/O now. */
+	isci_remote_device_nuke_requests(isci_dev);
+
+	/* Call into the libsas default handler (which calls sas_phy_reset). */
+	base_status = sas_eh_bus_reset_handler(cmd);
+
+	if (base_status != SUCCESS) {
+
+		/* There can be cases where the resets to individual devices
+		 * behind an expander will fail because of an unplug of the
+		 * expander itself.
+		 */
+		scmd_printk(KERN_WARNING, cmd,
+			    "%s: sas_eh_bus_reset_handler(%p) returned %d!\n",
+			    __func__, cmd, base_status);
+	}
+
+	/* WHAT TO DO HERE IF sas_phy_reset FAILS? */
+
+	if (isci_host != NULL)
+		spin_lock_irqsave(&isci_host->scic_lock, flags);
+	status
+		= scic_remote_device_reset_complete(isci_dev->sci_device_handle);
+
+	if (isci_host != NULL)
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	if (status != SCI_SUCCESS) {
+		scmd_printk(KERN_WARNING, cmd,
+			    "%s: scic_remote_device_reset_complete(%p) "
+			    "returned %d!\n",
+			    __func__, isci_dev, status);
+	}
+	/* WHAT TO DO HERE IF scic_remote_device_reset_complete FAILS? */
+
+	dev_dbg(&cmd->device->sdev_gendev,
+		"%s: cmd %p, isci_dev %p complete.\n",
+		__func__, cmd, isci_dev);
+
+	/* Resume I/O to the remote device. */
+	isci_device_set_host_quiesce_lock_state(isci_dev, false);
+
+	return TMF_RESP_FUNC_COMPLETE;
+}