isci: uplevel request infrastructure

* Consolidate tiny header files
* Move files out of core/ (drop core/scic_sds_ prefix)
* Merge core/scic_sds_request.[ch] into request.[ch]
* Cleanup request.c namespace (clean forward declarations and global
  namespace pollution)

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 1701 insertions, 315 deletions

diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 4961ee34709..857ad067f11 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -54,407 +54,1128 @@
  */
 
 #include "isci.h"
-#include "scic_io_request.h"
-#include "scic_task_request.h"
 #include "scic_port.h"
 #include "task.h"
 #include "request.h"
 #include "sata.h"
 #include "scu_completion_codes.h"
-#include "scic_sds_request.h"
 #include "sas.h"
 
-static enum sci_status isci_request_ssp_request_construct(
-	struct isci_request *request)
+/**
+ * This method returns the sgl element pair for the specificed sgl_pair index.
+ * @sci_req: This parameter specifies the IO request for which to retrieve
+ *    the Scatter-Gather List element pair.
+ * @sgl_pair_index: This parameter specifies the index into the SGL element
+ *    pair to be retrieved.
+ *
+ * This method returns a pointer to an struct scu_sgl_element_pair.
+ */
+static struct scu_sgl_element_pair *scic_sds_request_get_sgl_element_pair(
+	struct scic_sds_request *sci_req,
+	u32 sgl_pair_index
+	) {
+	struct scu_task_context *task_context;
+
+	task_context = (struct scu_task_context *)sci_req->task_context_buffer;
+
+	if (sgl_pair_index == 0) {
+		return &task_context->sgl_pair_ab;
+	} else if (sgl_pair_index == 1) {
+		return &task_context->sgl_pair_cd;
+	}
+
+	return &sci_req->sg_table[sgl_pair_index - 2];
+}
+
+/**
+ * This function will build the SGL list for an IO request.
+ * @sci_req: This parameter specifies the IO request for which to build
+ *    the Scatter-Gather List.
+ *
+ */
+void scic_sds_request_build_sgl(struct scic_sds_request *sds_request)
 {
-	enum sci_status status;
+	struct isci_request *isci_request = sci_req_to_ireq(sds_request);
+	struct isci_host *isci_host = isci_request->isci_host;
+	struct sas_task *task = isci_request_access_task(isci_request);
+	struct scatterlist *sg = NULL;
+	dma_addr_t dma_addr;
+	u32 sg_idx = 0;
+	struct scu_sgl_element_pair *scu_sg   = NULL;
+	struct scu_sgl_element_pair *prev_sg  = NULL;
+
+	if (task->num_scatter > 0) {
+		sg = task->scatter;
+
+		while (sg) {
+			scu_sg = scic_sds_request_get_sgl_element_pair(
+					sds_request,
+					sg_idx);
+
+			SCU_SGL_COPY(scu_sg->A, sg);
+
+			sg = sg_next(sg);
+
+			if (sg) {
+				SCU_SGL_COPY(scu_sg->B, sg);
+				sg = sg_next(sg);
+			} else
+				SCU_SGL_ZERO(scu_sg->B);
+
+			if (prev_sg) {
+				dma_addr =
+					scic_io_request_get_dma_addr(
+							sds_request,
+							scu_sg);
+
+				prev_sg->next_pair_upper =
+					upper_32_bits(dma_addr);
+				prev_sg->next_pair_lower =
+					lower_32_bits(dma_addr);
+			}
+
+			prev_sg = scu_sg;
+			sg_idx++;
+		}
+	} else {	/* handle when no sg */
+		scu_sg = scic_sds_request_get_sgl_element_pair(sds_request,
+							       sg_idx);
 
-	dev_dbg(&request->isci_host->pdev->dev,
-		"%s: request = %p\n",
-		__func__,
-		request);
-	status = scic_io_request_construct_basic_ssp(&request->sci);
-	return status;
+		dma_addr = dma_map_single(&isci_host->pdev->dev,
+					  task->scatter,
+					  task->total_xfer_len,
+					  task->data_dir);
+
+		isci_request->zero_scatter_daddr = dma_addr;
+
+		scu_sg->A.length = task->total_xfer_len;
+		scu_sg->A.address_upper = upper_32_bits(dma_addr);
+		scu_sg->A.address_lower = lower_32_bits(dma_addr);
+	}
+
+	if (scu_sg) {
+		scu_sg->next_pair_upper = 0;
+		scu_sg->next_pair_lower = 0;
+	}
 }
 
-static enum sci_status isci_request_stp_request_construct(
-	struct isci_request *request)
+static void scic_sds_ssp_io_request_assign_buffers(struct scic_sds_request *sci_req)
 {
-	struct sas_task *task = isci_request_access_task(request);
-	enum sci_status status;
-	struct host_to_dev_fis *register_fis;
+	if (sci_req->was_tag_assigned_by_user == false)
+		sci_req->task_context_buffer = &sci_req->tc;
+}
 
-	dev_dbg(&request->isci_host->pdev->dev,
-		"%s: request = %p\n",
-		__func__,
-		request);
+static void scic_sds_io_request_build_ssp_command_iu(struct scic_sds_request *sci_req)
+{
+	struct ssp_cmd_iu *cmd_iu;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+	struct sas_task *task = isci_request_access_task(ireq);
 
-	/* Get the host_to_dev_fis from the core and copy
-	 * the fis from the task into it.
-	 */
-	register_fis = isci_sata_task_to_fis_copy(task);
+	cmd_iu = &sci_req->ssp.cmd;
 
-	status = scic_io_request_construct_basic_sata(&request->sci);
+	memcpy(cmd_iu->LUN, task->ssp_task.LUN, 8);
+	cmd_iu->add_cdb_len = 0;
+	cmd_iu->_r_a = 0;
+	cmd_iu->_r_b = 0;
+	cmd_iu->en_fburst = 0; /* unsupported */
+	cmd_iu->task_prio = task->ssp_task.task_prio;
+	cmd_iu->task_attr = task->ssp_task.task_attr;
+	cmd_iu->_r_c = 0;
 
-	/* Set the ncq tag in the fis, from the queue
-	 * command in the task.
-	 */
-	if (isci_sata_is_task_ncq(task)) {
+	sci_swab32_cpy(&cmd_iu->cdb, task->ssp_task.cdb,
+		       sizeof(task->ssp_task.cdb) / sizeof(u32));
+}
 
-		isci_sata_set_ncq_tag(
-			register_fis,
-			task
-			);
+static void scic_sds_task_request_build_ssp_task_iu(struct scic_sds_request *sci_req)
+{
+	struct ssp_task_iu *task_iu;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+	struct sas_task *task = isci_request_access_task(ireq);
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);
+
+	task_iu = &sci_req->ssp.tmf;
+
+	memset(task_iu, 0, sizeof(struct ssp_task_iu));
+
+	memcpy(task_iu->LUN, task->ssp_task.LUN, 8);
+
+	task_iu->task_func = isci_tmf->tmf_code;
+	task_iu->task_tag =
+		(ireq->ttype == tmf_task) ?
+		isci_tmf->io_tag :
+		SCI_CONTROLLER_INVALID_IO_TAG;
+}
+
+/**
+ * This method is will fill in the SCU Task Context for any type of SSP request.
+ * @sci_req:
+ * @task_context:
+ *
+ */
+static void scu_ssp_reqeust_construct_task_context(
+	struct scic_sds_request *sds_request,
+	struct scu_task_context *task_context)
+{
+	dma_addr_t dma_addr;
+	struct scic_sds_controller *controller;
+	struct scic_sds_remote_device *target_device;
+	struct scic_sds_port *target_port;
+
+	controller = scic_sds_request_get_controller(sds_request);
+	target_device = scic_sds_request_get_device(sds_request);
+	target_port = scic_sds_request_get_port(sds_request);
+
+	/* Fill in the TC with the its required data */
+	task_context->abort = 0;
+	task_context->priority = 0;
+	task_context->initiator_request = 1;
+	task_context->connection_rate = target_device->connection_rate;
+	task_context->protocol_engine_index =
+		scic_sds_controller_get_protocol_engine_group(controller);
+	task_context->logical_port_index =
+		scic_sds_port_get_index(target_port);
+	task_context->protocol_type = SCU_TASK_CONTEXT_PROTOCOL_SSP;
+	task_context->valid = SCU_TASK_CONTEXT_VALID;
+	task_context->context_type = SCU_TASK_CONTEXT_TYPE;
+
+	task_context->remote_node_index =
+		scic_sds_remote_device_get_index(sds_request->target_device);
+	task_context->command_code = 0;
+
+	task_context->link_layer_control = 0;
+	task_context->do_not_dma_ssp_good_response = 1;
+	task_context->strict_ordering = 0;
+	task_context->control_frame = 0;
+	task_context->timeout_enable = 0;
+	task_context->block_guard_enable = 0;
+
+	task_context->address_modifier = 0;
+
+	/* task_context->type.ssp.tag = sci_req->io_tag; */
+	task_context->task_phase = 0x01;
+
+	if (sds_request->was_tag_assigned_by_user) {
+		/*
+		 * Build the task context now since we have already read
+		 * the data
+		 */
+		sds_request->post_context =
+			(SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC |
+			 (scic_sds_controller_get_protocol_engine_group(
+							controller) <<
+			  SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
+			 (scic_sds_port_get_index(target_port) <<
+			  SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
+			 scic_sds_io_tag_get_index(sds_request->io_tag));
+	} else {
+		/*
+		 * Build the task context now since we have already read
+		 * the data
+		 *
+		 * I/O tag index is not assigned because we have to wait
+		 * until we get a TCi
+		 */
+		sds_request->post_context =
+			(SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC |
+			 (scic_sds_controller_get_protocol_engine_group(
+							owning_controller) <<
+			  SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
+			 (scic_sds_port_get_index(target_port) <<
+			  SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT));
 	}
 
-	return status;
+	/*
+	 * Copy the physical address for the command buffer to the
+	 * SCU Task Context
+	 */
+	dma_addr = scic_io_request_get_dma_addr(sds_request,
+						&sds_request->ssp.cmd);
+
+	task_context->command_iu_upper = upper_32_bits(dma_addr);
+	task_context->command_iu_lower = lower_32_bits(dma_addr);
+
+	/*
+	 * Copy the physical address for the response buffer to the
+	 * SCU Task Context
+	 */
+	dma_addr = scic_io_request_get_dma_addr(sds_request,
+						&sds_request->ssp.rsp);
+
+	task_context->response_iu_upper = upper_32_bits(dma_addr);
+	task_context->response_iu_lower = lower_32_bits(dma_addr);
 }
 
-/*
- * isci_smp_request_build() - This function builds the smp request.
- * @ireq: This parameter points to the isci_request allocated in the
- *    request construct function.
+/**
+ * This method is will fill in the SCU Task Context for a SSP IO request.
+ * @sci_req:
  *
- * SCI_SUCCESS on successfull completion, or specific failure code.
  */
-static enum sci_status isci_smp_request_build(struct isci_request *ireq)
+static void scu_ssp_io_request_construct_task_context(
+	struct scic_sds_request *sci_req,
+	enum dma_data_direction dir,
+	u32 len)
 {
-	enum sci_status status = SCI_FAILURE;
-	struct sas_task *task = isci_request_access_task(ireq);
-	struct scic_sds_request *sci_req = &ireq->sci;
+	struct scu_task_context *task_context;
 
-	dev_dbg(&ireq->isci_host->pdev->dev,
-		"%s: request = %p\n", __func__, ireq);
+	task_context = scic_sds_request_get_task_context(sci_req);
 
-	dev_dbg(&ireq->isci_host->pdev->dev,
-		"%s: smp_req len = %d\n",
-		__func__,
-		task->smp_task.smp_req.length);
+	scu_ssp_reqeust_construct_task_context(sci_req, task_context);
 
-	/* copy the smp_command to the address; */
-	sg_copy_to_buffer(&task->smp_task.smp_req, 1,
-			  &sci_req->smp.cmd,
-			  sizeof(struct smp_req));
+	task_context->ssp_command_iu_length =
+		sizeof(struct ssp_cmd_iu) / sizeof(u32);
+	task_context->type.ssp.frame_type = SSP_COMMAND;
 
-	status = scic_io_request_construct_smp(sci_req);
-	if (status != SCI_SUCCESS)
-		dev_warn(&ireq->isci_host->pdev->dev,
-			 "%s: failed with status = %d\n",
-			 __func__,
-			 status);
+	switch (dir) {
+	case DMA_FROM_DEVICE:
+	case DMA_NONE:
+	default:
+		task_context->task_type = SCU_TASK_TYPE_IOREAD;
+		break;
+	case DMA_TO_DEVICE:
+		task_context->task_type = SCU_TASK_TYPE_IOWRITE;
+		break;
+	}
 
-	return status;
+	task_context->transfer_length_bytes = len;
+
+	if (task_context->transfer_length_bytes > 0)
+		scic_sds_request_build_sgl(sci_req);
+}
+
+static void scic_sds_ssp_task_request_assign_buffers(struct scic_sds_request *sci_req)
+{
+	if (sci_req->was_tag_assigned_by_user == false)
+		sci_req->task_context_buffer = &sci_req->tc;
 }
 
 /**
- * isci_io_request_build() - This function builds the io 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.
- * @sci_device: This parameter is the handle for the sci core's remote device
- *    object that is the destination for this request.
+ * This method will fill in the SCU Task Context for a SSP Task request.  The
+ *    following important settings are utilized: -# priority ==
+ *    SCU_TASK_PRIORITY_HIGH.  This ensures that the task request is issued
+ *    ahead of other task destined for the same Remote Node. -# task_type ==
+ *    SCU_TASK_TYPE_IOREAD.  This simply indicates that a normal request type
+ *    (i.e. non-raw frame) is being utilized to perform task management. -#
+ *    control_frame == 1.  This ensures that the proper endianess is set so
+ *    that the bytes are transmitted in the right order for a task frame.
+ * @sci_req: This parameter specifies the task request object being
+ *    constructed.
  *
- * SCI_SUCCESS on successfull completion, or specific failure code.
  */
-static enum sci_status isci_io_request_build(
-	struct isci_host *isci_host,
-	struct isci_request *request,
-	struct isci_remote_device *isci_device)
+static void scu_ssp_task_request_construct_task_context(
+	struct scic_sds_request *sci_req)
 {
-	enum sci_status status = SCI_SUCCESS;
-	struct sas_task *task = isci_request_access_task(request);
-	struct scic_sds_remote_device *sci_device = &isci_device->sci;
+	struct scu_task_context *task_context;
 
-	dev_dbg(&isci_host->pdev->dev,
-		"%s: isci_device = 0x%p; request = %p, "
-		"num_scatter = %d\n",
-		__func__,
-		isci_device,
-		request,
-		task->num_scatter);
+	task_context = scic_sds_request_get_task_context(sci_req);
 
-	/* map the sgl addresses, if present.
-	 * libata does the mapping for sata devices
-	 * before we get the request.
-	 */
-	if (task->num_scatter &&
-	    !sas_protocol_ata(task->task_proto) &&
-	    !(SAS_PROTOCOL_SMP & task->task_proto)) {
+	scu_ssp_reqeust_construct_task_context(sci_req, task_context);
 
-		request->num_sg_entries = dma_map_sg(
-			&isci_host->pdev->dev,
-			task->scatter,
-			task->num_scatter,
-			task->data_dir
-			);
+	task_context->control_frame                = 1;
+	task_context->priority                     = SCU_TASK_PRIORITY_HIGH;
+	task_context->task_type                    = SCU_TASK_TYPE_RAW_FRAME;
+	task_context->transfer_length_bytes        = 0;
+	task_context->type.ssp.frame_type          = SSP_TASK;
+	task_context->ssp_command_iu_length =
+		sizeof(struct ssp_task_iu) / sizeof(u32);
+}
 
-		if (request->num_sg_entries == 0)
-			return SCI_FAILURE_INSUFFICIENT_RESOURCES;
-	}
 
-	/* build the common request object. For now,
-	 * we will let the core allocate the IO tag.
-	 */
-	status = scic_io_request_construct(&isci_host->sci, sci_device,
-					   SCI_CONTROLLER_INVALID_IO_TAG,
-					   &request->sci);
+/**
+ * This method constructs the SSP Command IU data for this ssp passthrough
+ *    comand request object.
+ * @sci_req: This parameter specifies the request object for which the SSP
+ *    command information unit is being built.
+ *
+ * enum sci_status, returns invalid parameter is cdb > 16
+ */
 
-	if (status != SCI_SUCCESS) {
-		dev_warn(&isci_host->pdev->dev,
-			 "%s: failed request construct\n",
-			 __func__);
-		return SCI_FAILURE;
+
+/**
+ * This method constructs the SATA request object.
+ * @sci_req:
+ * @sat_protocol:
+ * @transfer_length:
+ * @data_direction:
+ * @copy_rx_frame:
+ *
+ * enum sci_status
+ */
+static enum sci_status
+scic_io_request_construct_sata(struct scic_sds_request *sci_req,
+			       u32 len,
+			       enum dma_data_direction dir,
+			       bool copy)
+{
+	enum sci_status status = SCI_SUCCESS;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+	struct sas_task *task = isci_request_access_task(ireq);
+
+	/* check for management protocols */
+	if (ireq->ttype == tmf_task) {
+		struct isci_tmf *tmf = isci_request_access_tmf(ireq);
+
+		if (tmf->tmf_code == isci_tmf_sata_srst_high ||
+		    tmf->tmf_code == isci_tmf_sata_srst_low)
+			return scic_sds_stp_soft_reset_request_construct(sci_req);
+		else {
+			dev_err(scic_to_dev(sci_req->owning_controller),
+				"%s: Request 0x%p received un-handled SAT "
+				"management protocol 0x%x.\n",
+				__func__, sci_req, tmf->tmf_code);
+
+			return SCI_FAILURE;
+		}
 	}
 
-	switch (task->task_proto) {
-	case SAS_PROTOCOL_SMP:
-		status = isci_smp_request_build(request);
-		break;
-	case SAS_PROTOCOL_SSP:
-		status = isci_request_ssp_request_construct(request);
-		break;
-	case SAS_PROTOCOL_SATA:
-	case SAS_PROTOCOL_STP:
-	case SAS_PROTOCOL_SATA | SAS_PROTOCOL_STP:
-		status = isci_request_stp_request_construct(request);
-		break;
-	default:
-		dev_warn(&isci_host->pdev->dev,
-			 "%s: unknown protocol\n", __func__);
+	if (!sas_protocol_ata(task->task_proto)) {
+		dev_err(scic_to_dev(sci_req->owning_controller),
+			"%s: Non-ATA protocol in SATA path: 0x%x\n",
+			__func__,
+			task->task_proto);
 		return SCI_FAILURE;
+
 	}
 
+	/* non data */
+	if (task->data_dir == DMA_NONE)
+		return scic_sds_stp_non_data_request_construct(sci_req);
+
+	/* NCQ */
+	if (task->ata_task.use_ncq)
+		return scic_sds_stp_ncq_request_construct(sci_req, len, dir);
+
+	/* DMA */
+	if (task->ata_task.dma_xfer)
+		return scic_sds_stp_udma_request_construct(sci_req, len, dir);
+	else /* PIO */
+		return scic_sds_stp_pio_request_construct(sci_req, copy);
+
+	return status;
+}
+
+static enum sci_status scic_io_request_construct_basic_ssp(struct scic_sds_request *sci_req)
+{
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+	struct sas_task *task = isci_request_access_task(ireq);
+
+	sci_req->protocol = SCIC_SSP_PROTOCOL;
+
+	scu_ssp_io_request_construct_task_context(sci_req,
+						  task->data_dir,
+						  task->total_xfer_len);
+
+	scic_sds_io_request_build_ssp_command_iu(sci_req);
+
+	sci_base_state_machine_change_state(
+			&sci_req->state_machine,
+			SCI_BASE_REQUEST_STATE_CONSTRUCTED);
+
+	return SCI_SUCCESS;
+}
+
+enum sci_status scic_task_request_construct_ssp(
+	struct scic_sds_request *sci_req)
+{
+	/* Construct the SSP Task SCU Task Context */
+	scu_ssp_task_request_construct_task_context(sci_req);
+
+	/* Fill in the SSP Task IU */
+	scic_sds_task_request_build_ssp_task_iu(sci_req);
+
+	sci_base_state_machine_change_state(&sci_req->state_machine,
+		SCI_BASE_REQUEST_STATE_CONSTRUCTED);
+
 	return SCI_SUCCESS;
 }
 
 
+static enum sci_status scic_io_request_construct_basic_sata(struct scic_sds_request *sci_req)
+{
+	enum sci_status status;
+	struct scic_sds_stp_request *stp_req;
+	bool copy = false;
+	struct isci_request *isci_request = sci_req_to_ireq(sci_req);
+	struct sas_task *task = isci_request_access_task(isci_request);
+
+	stp_req = &sci_req->stp.req;
+	sci_req->protocol = SCIC_STP_PROTOCOL;
+
+	copy = (task->data_dir == DMA_NONE) ? false : true;
+
+	status = scic_io_request_construct_sata(sci_req,
+						task->total_xfer_len,
+						task->data_dir,
+						copy);
+
+	if (status == SCI_SUCCESS)
+		sci_base_state_machine_change_state(&sci_req->state_machine,
+			SCI_BASE_REQUEST_STATE_CONSTRUCTED);
+
+	return status;
+}
+
+
+enum sci_status scic_task_request_construct_sata(struct scic_sds_request *sci_req)
+{
+	enum sci_status status = SCI_SUCCESS;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+
+	/* check for management protocols */
+	if (ireq->ttype == tmf_task) {
+		struct isci_tmf *tmf = isci_request_access_tmf(ireq);
+
+		if (tmf->tmf_code == isci_tmf_sata_srst_high ||
+		    tmf->tmf_code == isci_tmf_sata_srst_low) {
+			status = scic_sds_stp_soft_reset_request_construct(sci_req);
+		} else {
+			dev_err(scic_to_dev(sci_req->owning_controller),
+				"%s: Request 0x%p received un-handled SAT "
+				"Protocol 0x%x.\n",
+				__func__, sci_req, tmf->tmf_code);
+
+			return SCI_FAILURE;
+		}
+	}
+
+	if (status == SCI_SUCCESS)
+		sci_base_state_machine_change_state(
+				&sci_req->state_machine,
+				SCI_BASE_REQUEST_STATE_CONSTRUCTED);
+
+	return status;
+}
+
 /**
- * isci_request_alloc_core() - This function gets the request object from the
- *    isci_host dma cache.
- * @isci_host: This parameter specifies the ISCI host object
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @isci_device: This parameter is the pointer to the isci remote device object
- *    that is the destination for this request.
- * @gfp_flags: This parameter specifies the os allocation flags.
- *
- * SCI_SUCCESS on successfull completion, or specific failure code.
+ * sci_req_tx_bytes - bytes transferred when reply underruns request
+ * @sci_req: request that was terminated early
  */
-static int isci_request_alloc_core(
-	struct isci_host *isci_host,
-	struct isci_request **isci_request,
-	struct isci_remote_device *isci_device,
-	gfp_t gfp_flags)
+#define SCU_TASK_CONTEXT_SRAM 0x200000
+static u32 sci_req_tx_bytes(struct scic_sds_request *sci_req)
 {
-	int ret = 0;
-	dma_addr_t handle;
-	struct isci_request *request;
+	struct scic_sds_controller *scic = sci_req->owning_controller;
+	u32 ret_val = 0;
 
+	if (readl(&scic->smu_registers->address_modifier) == 0) {
+		void __iomem *scu_reg_base = scic->scu_registers;
 
-	/* get pointer to dma memory. This actually points
-	 * to both the isci_remote_device object and the
-	 * sci object. The isci object is at the beginning
-	 * of the memory allocated here.
-	 */
-	request = dma_pool_alloc(isci_host->dma_pool, gfp_flags, &handle);
-	if (!request) {
-		dev_warn(&isci_host->pdev->dev,
-			 "%s: dma_pool_alloc returned NULL\n", __func__);
-		return -ENOMEM;
+		/* get the bytes of data from the Address == BAR1 + 20002Ch + (256*TCi) where
+		 *   BAR1 is the scu_registers
+		 *   0x20002C = 0x200000 + 0x2c
+		 *            = start of task context SRAM + offset of (type.ssp.data_offset)
+		 *   TCi is the io_tag of struct scic_sds_request
+		 */
+		ret_val = readl(scu_reg_base +
+				(SCU_TASK_CONTEXT_SRAM + offsetof(struct scu_task_context, type.ssp.data_offset)) +
+				((sizeof(struct scu_task_context)) * scic_sds_io_tag_get_index(sci_req->io_tag)));
 	}
 
-	/* initialize the request object.	*/
-	spin_lock_init(&request->state_lock);
-	request->request_daddr = handle;
-	request->isci_host = isci_host;
-	request->isci_device = isci_device;
-	request->io_request_completion = NULL;
-	request->terminated = false;
+	return ret_val;
+}
 
-	request->num_sg_entries = 0;
+enum sci_status
+scic_sds_request_start(struct scic_sds_request *request)
+{
+	if (request->device_sequence !=
+	    scic_sds_remote_device_get_sequence(request->target_device))
+		return SCI_FAILURE;
 
-	request->complete_in_target = false;
+	if (request->state_handlers->start_handler)
+		return request->state_handlers->start_handler(request);
 
-	INIT_LIST_HEAD(&request->completed_node);
-	INIT_LIST_HEAD(&request->dev_node);
+	dev_warn(scic_to_dev(request->owning_controller),
+		 "%s: SCIC IO Request requested to start while in wrong "
+		 "state %d\n",
+		 __func__,
+		 sci_base_state_machine_get_state(&request->state_machine));
 
-	*isci_request = request;
-	isci_request_change_state(request, allocated);
+	return SCI_FAILURE_INVALID_STATE;
+}
 
-	return ret;
+enum sci_status
+scic_sds_io_request_terminate(struct scic_sds_request *request)
+{
+	if (request->state_handlers->abort_handler)
+		return request->state_handlers->abort_handler(request);
+
+	dev_warn(scic_to_dev(request->owning_controller),
+		"%s: SCIC IO Request requested to abort while in wrong "
+		"state %d\n",
+		__func__,
+		sci_base_state_machine_get_state(&request->state_machine));
+
+	return SCI_FAILURE_INVALID_STATE;
 }
 
-static int isci_request_alloc_io(
-	struct isci_host *isci_host,
-	struct sas_task *task,
-	struct isci_request **isci_request,
-	struct isci_remote_device *isci_device,
-	gfp_t gfp_flags)
+enum sci_status scic_sds_io_request_event_handler(
+	struct scic_sds_request *request,
+	u32 event_code)
 {
-	int retval = isci_request_alloc_core(isci_host, isci_request,
-					     isci_device, gfp_flags);
+	if (request->state_handlers->event_handler)
+		return request->state_handlers->event_handler(request, event_code);
 
-	if (!retval) {
-		(*isci_request)->ttype_ptr.io_task_ptr = task;
-		(*isci_request)->ttype                 = io_task;
+	dev_warn(scic_to_dev(request->owning_controller),
+		 "%s: SCIC IO Request given event code notification %x while "
+		 "in wrong state %d\n",
+		 __func__,
+		 event_code,
+		 sci_base_state_machine_get_state(&request->state_machine));
 
-		task->lldd_task = *isci_request;
-	}
-	return retval;
+	return SCI_FAILURE_INVALID_STATE;
 }
 
 /**
- * isci_request_alloc_tmf() - This function gets the request object from the
- *    isci_host dma cache and initializes the relevant fields as a sas_task.
- * @isci_host: This parameter specifies the ISCI host object
- * @sas_task: This parameter is the task struct from the upper layer driver.
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @isci_device: This parameter is the pointer to the isci remote device object
- *    that is the destination for this request.
- * @gfp_flags: This parameter specifies the os allocation flags.
  *
- * SCI_SUCCESS on successfull completion, or specific failure code.
+ * @sci_req: The SCIC_SDS_IO_REQUEST_T object for which the start
+ *    operation is to be executed.
+ * @frame_index: The frame index returned by the hardware for the reqeust
+ *    object.
+ *
+ * This method invokes the core state frame handler for the
+ * SCIC_SDS_IO_REQUEST_T object. enum sci_status
  */
-int isci_request_alloc_tmf(
-	struct isci_host *isci_host,
-	struct isci_tmf *isci_tmf,
-	struct isci_request **isci_request,
-	struct isci_remote_device *isci_device,
-	gfp_t gfp_flags)
+enum sci_status scic_sds_io_request_frame_handler(
+	struct scic_sds_request *request,
+	u32 frame_index)
 {
-	int retval = isci_request_alloc_core(isci_host, isci_request,
-					     isci_device, gfp_flags);
+	if (request->state_handlers->frame_handler)
+		return request->state_handlers->frame_handler(request, frame_index);
+
+	dev_warn(scic_to_dev(request->owning_controller),
+		 "%s: SCIC IO Request given unexpected frame %x while in "
+		 "state %d\n",
+		 __func__,
+		 frame_index,
+		 sci_base_state_machine_get_state(&request->state_machine));
+
+	scic_sds_controller_release_frame(request->owning_controller, frame_index);
+	return SCI_FAILURE_INVALID_STATE;
+}
 
-	if (!retval) {
+/*
+ * This function copies response data for requests returning response data
+ *    instead of sense data.
+ * @sci_req: This parameter specifies the request object for which to copy
+ *    the response data.
+ */
+void scic_sds_io_request_copy_response(struct scic_sds_request *sci_req)
+{
+	void *resp_buf;
+	u32 len;
+	struct ssp_response_iu *ssp_response;
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+	struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);
 
-		(*isci_request)->ttype_ptr.tmf_task_ptr = isci_tmf;
-		(*isci_request)->ttype = tmf_task;
+	ssp_response = &sci_req->ssp.rsp;
+
+	resp_buf = &isci_tmf->resp.resp_iu;
+
+	len = min_t(u32,
+		    SSP_RESP_IU_MAX_SIZE,
+		    be32_to_cpu(ssp_response->response_data_len));
+
+	memcpy(resp_buf, ssp_response->resp_data, len);
+}
+
+/*
+ * This method implements the action taken when a constructed
+ * SCIC_SDS_IO_REQUEST_T object receives a scic_sds_request_start() request.
+ * This method will, if necessary, allocate a TCi for the io request object and
+ * then will, if necessary, copy the constructed TC data into the actual TC
+ * buffer.  If everything is successful the post context field is updated with
+ * the TCi so the controller can post the request to the hardware. enum sci_status
+ * SCI_SUCCESS SCI_FAILURE_INSUFFICIENT_RESOURCES
+ */
+static enum sci_status scic_sds_request_constructed_state_start_handler(
+	struct scic_sds_request *request)
+{
+	struct scu_task_context *task_context;
+
+	if (request->io_tag == SCI_CONTROLLER_INVALID_IO_TAG) {
+		request->io_tag =
+			scic_controller_allocate_io_tag(request->owning_controller);
 	}
-	return retval;
+
+	/* Record the IO Tag in the request */
+	if (request->io_tag != SCI_CONTROLLER_INVALID_IO_TAG) {
+		task_context = request->task_context_buffer;
+
+		task_context->task_index = scic_sds_io_tag_get_index(request->io_tag);
+
+		switch (task_context->protocol_type) {
+		case SCU_TASK_CONTEXT_PROTOCOL_SMP:
+		case SCU_TASK_CONTEXT_PROTOCOL_SSP:
+			/* SSP/SMP Frame */
+			task_context->type.ssp.tag = request->io_tag;
+			task_context->type.ssp.target_port_transfer_tag = 0xFFFF;
+			break;
+
+		case SCU_TASK_CONTEXT_PROTOCOL_STP:
+			/*
+			 * STP/SATA Frame
+			 * task_context->type.stp.ncq_tag = request->ncq_tag; */
+			break;
+
+		case SCU_TASK_CONTEXT_PROTOCOL_NONE:
+			/* / @todo When do we set no protocol type? */
+			break;
+
+		default:
+			/* This should never happen since we build the IO requests */
+			break;
+		}
+
+		/*
+		 * Check to see if we need to copy the task context buffer
+		 * or have been building into the task context buffer */
+		if (request->was_tag_assigned_by_user == false) {
+			scic_sds_controller_copy_task_context(
+				request->owning_controller, request);
+		}
+
+		/* Add to the post_context the io tag value */
+		request->post_context |= scic_sds_io_tag_get_index(request->io_tag);
+
+		/* Everything is good go ahead and change state */
+		sci_base_state_machine_change_state(&request->state_machine,
+			SCI_BASE_REQUEST_STATE_STARTED);
+
+		return SCI_SUCCESS;
+	}
+
+	return SCI_FAILURE_INSUFFICIENT_RESOURCES;
 }
 
-/**
- * isci_request_execute() - This function allocates the isci_request object,
- *    all fills in some common fields.
- * @isci_host: This parameter specifies the ISCI host object
- * @sas_task: This parameter is the task struct from the upper layer driver.
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @gfp_flags: This parameter specifies the os allocation flags.
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_terminate() request. Since the request
+ * has not yet been posted to the hardware the request transitions to the
+ * completed state. enum sci_status SCI_SUCCESS
+ */
+static enum sci_status scic_sds_request_constructed_state_abort_handler(
+	struct scic_sds_request *request)
+{
+	/*
+	 * This request has been terminated by the user make sure that the correct
+	 * status code is returned */
+	scic_sds_request_set_status(request,
+		SCU_TASK_DONE_TASK_ABORT,
+		SCI_FAILURE_IO_TERMINATED);
+
+	sci_base_state_machine_change_state(&request->state_machine,
+		SCI_BASE_REQUEST_STATE_COMPLETED);
+	return SCI_SUCCESS;
+}
+
+/*
+ * *****************************************************************************
+ * *  STARTED STATE HANDLERS
+ * ***************************************************************************** */
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_terminate() request. Since the request
+ * has been posted to the hardware the io request state is changed to the
+ * aborting state. enum sci_status SCI_SUCCESS
+ */
+enum sci_status scic_sds_request_started_state_abort_handler(
+	struct scic_sds_request *request)
+{
+	if (request->has_started_substate_machine)
+		sci_base_state_machine_stop(&request->started_substate_machine);
+
+	sci_base_state_machine_change_state(&request->state_machine,
+		SCI_BASE_REQUEST_STATE_ABORTING);
+	return SCI_SUCCESS;
+}
+
+/*
+ * scic_sds_request_started_state_tc_completion_handler() - This method process
+ *    TC (task context) completions for normal IO request (i.e. Task/Abort
+ *    Completions of type 0).  This method will update the
+ *    SCIC_SDS_IO_REQUEST_T::status field.
+ * @sci_req: This parameter specifies the request for which a completion
+ *    occurred.
+ * @completion_code: This parameter specifies the completion code received from
+ *    the SCU.
  *
- * SCI_SUCCESS on successfull completion, or specific failure code.
  */
-int isci_request_execute(
-	struct isci_host *isci_host,
-	struct sas_task *task,
-	struct isci_request **isci_request,
-	gfp_t gfp_flags)
+static enum sci_status
+scic_sds_request_started_state_tc_completion_handler(struct scic_sds_request *sci_req,
+						     u32 completion_code)
 {
-	int ret = 0;
-	struct scic_sds_remote_device *sci_device;
-	enum sci_status status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
-	struct isci_remote_device *isci_device;
-	struct isci_request *request;
-	unsigned long flags;
+	u8 datapres;
+	struct ssp_response_iu *resp_iu;
 
-	isci_device = task->dev->lldd_dev;
-	sci_device = &isci_device->sci;
+	/*
+	 * TODO: Any SDMA return code of other than 0 is bad
+	 *       decode 0x003C0000 to determine SDMA status
+	 */
+	switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
+		scic_sds_request_set_status(sci_req,
+					    SCU_TASK_DONE_GOOD,
+					    SCI_SUCCESS);
+		break;
 
-	/* do common allocation and init of request object. */
-	ret = isci_request_alloc_io(
-		isci_host,
-		task,
-		&request,
-		isci_device,
-		gfp_flags
-		);
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_EARLY_RESP):
+	{
+		/*
+		 * There are times when the SCU hardware will return an early
+		 * response because the io request specified more data than is
+		 * returned by the target device (mode pages, inquiry data,
+		 * etc.).  We must check the response stats to see if this is
+		 * truly a failed request or a good request that just got
+		 * completed early.
+		 */
+		struct ssp_response_iu *resp = &sci_req->ssp.rsp;
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
+
+		sci_swab32_cpy(&sci_req->ssp.rsp,
+			       &sci_req->ssp.rsp,
+			       word_cnt);
+
+		if (resp->status == 0) {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_TASK_DONE_GOOD,
+				SCI_SUCCESS_IO_DONE_EARLY);
+		} else {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_TASK_DONE_CHECK_RESPONSE,
+				SCI_FAILURE_IO_RESPONSE_VALID);
+		}
+	}
+	break;
 
-	if (ret)
-		goto out;
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_CHECK_RESPONSE):
+	{
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
 
-	status = isci_io_request_build(isci_host, request, isci_device);
-	if (status != SCI_SUCCESS) {
-		dev_warn(&isci_host->pdev->dev,
-			 "%s: request_construct failed - status = 0x%x\n",
-			 __func__,
-			 status);
-		goto out;
+		sci_swab32_cpy(&sci_req->ssp.rsp,
+			       &sci_req->ssp.rsp,
+			       word_cnt);
+
+		scic_sds_request_set_status(sci_req,
+					    SCU_TASK_DONE_CHECK_RESPONSE,
+					    SCI_FAILURE_IO_RESPONSE_VALID);
+		break;
 	}
 
-	spin_lock_irqsave(&isci_host->scic_lock, flags);
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_RESP_LEN_ERR):
+		/*
+		 * / @todo With TASK_DONE_RESP_LEN_ERR is the response frame
+		 * guaranteed to be received before this completion status is
+		 * posted?
+		 */
+		resp_iu = &sci_req->ssp.rsp;
+		datapres = resp_iu->datapres;
+
+		if ((datapres == 0x01) || (datapres == 0x02)) {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_TASK_DONE_CHECK_RESPONSE,
+				SCI_FAILURE_IO_RESPONSE_VALID);
+		} else
+			scic_sds_request_set_status(
+				sci_req, SCU_TASK_DONE_GOOD, SCI_SUCCESS);
+		break;
 
-	/* send the request, let the core assign the IO TAG.	*/
-	status = scic_controller_start_io(&isci_host->sci, sci_device,
-					  &request->sci,
-					  SCI_CONTROLLER_INVALID_IO_TAG);
-	if (status != SCI_SUCCESS &&
-	    status != SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
-		dev_warn(&isci_host->pdev->dev,
-			 "%s: failed request start (0x%x)\n",
-			 __func__, status);
-		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
-		goto out;
+	/* only stp device gets suspended. */
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_ACK_NAK_TO):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_LL_PERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_NAK_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_DATA_LEN_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_LL_ABORT_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_XR_WD_LEN):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_MAX_PLD_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_UNEXP_RESP):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_UNEXP_SDBFIS):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_REG_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SDB_ERR):
+		if (sci_req->protocol == SCIC_STP_PROTOCOL) {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
+				SCU_COMPLETION_TL_STATUS_SHIFT,
+				SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED);
+		} else {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
+				SCU_COMPLETION_TL_STATUS_SHIFT,
+				SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR);
+		}
+		break;
+
+	/* both stp/ssp device gets suspended */
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_LF_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_WRONG_DESTINATION):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_BAD_DESTINATION):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_ZONE_VIOLATION):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_STP_RESOURCES_BUSY):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_PROTOCOL_NOT_SUPPORTED):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_OPEN_REJECT_CONNECTION_RATE_NOT_SUPPORTED):
+		scic_sds_request_set_status(
+			sci_req,
+			SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
+			SCU_COMPLETION_TL_STATUS_SHIFT,
+			SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED);
+		break;
+
+	/* neither ssp nor stp gets suspended. */
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_NAK_CMD_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_UNEXP_XR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_XR_IU_LEN_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SDMA_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_OFFSET_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_EXCESS_DATA):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SMP_RESP_TO_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SMP_UFI_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SMP_FRM_TYPE_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_SMP_LL_RX_ERR):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_UNEXP_DATA):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_OPEN_FAIL):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_VIIT_ENTRY_NV):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_IIT_ENTRY_NV):
+	case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_RNCNV_OUTBOUND):
+	default:
+		scic_sds_request_set_status(
+			sci_req,
+			SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
+			SCU_COMPLETION_TL_STATUS_SHIFT,
+			SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR);
+		break;
 	}
 
-	/* Either I/O started OK, or the core has signaled that
-	 * the device needs a target reset.
-	 *
-	 * In either case, hold onto the I/O for later.
-	 *
-	 * Update it's status and add it to the list in the
-	 * remote device object.
+	/*
+	 * TODO: This is probably wrong for ACK/NAK timeout conditions
 	 */
-	isci_request_change_state(request, started);
-	list_add(&request->dev_node, &isci_device->reqs_in_process);
 
-	if (status == SCI_SUCCESS) {
-		/* Save the tag for possible task mgmt later. */
-		request->io_tag = scic_io_request_get_io_tag(&request->sci);
+	/* In all cases we will treat this as the completion of the IO req. */
+	sci_base_state_machine_change_state(
+			&sci_req->state_machine,
+			SCI_BASE_REQUEST_STATE_COMPLETED);
+	return SCI_SUCCESS;
+}
+
+enum sci_status
+scic_sds_io_request_tc_completion(struct scic_sds_request *request, u32 completion_code)
+{
+	if (request->state_machine.current_state_id == SCI_BASE_REQUEST_STATE_STARTED &&
+	    request->has_started_substate_machine == false)
+		return scic_sds_request_started_state_tc_completion_handler(request, completion_code);
+	else if (request->state_handlers->tc_completion_handler)
+		return request->state_handlers->tc_completion_handler(request, completion_code);
+
+	dev_warn(scic_to_dev(request->owning_controller),
+		"%s: SCIC IO Request given task completion notification %x "
+		"while in wrong state %d\n",
+		__func__,
+		completion_code,
+		sci_base_state_machine_get_state(&request->state_machine));
+
+	return SCI_FAILURE_INVALID_STATE;
+
+}
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_frame_handler() request. This method
+ * first determines the frame type received.  If this is a response frame then
+ * the response data is copied to the io request response buffer for processing
+ * at completion time. If the frame type is not a response buffer an error is
+ * logged. enum sci_status SCI_SUCCESS SCI_FAILURE_INVALID_PARAMETER_VALUE
+ */
+static enum sci_status
+scic_sds_request_started_state_frame_handler(struct scic_sds_request *sci_req,
+					     u32 frame_index)
+{
+	enum sci_status status;
+	u32 *frame_header;
+	struct ssp_frame_hdr ssp_hdr;
+	ssize_t word_cnt;
+
+	status = scic_sds_unsolicited_frame_control_get_header(
+		&(scic_sds_request_get_controller(sci_req)->uf_control),
+		frame_index,
+		(void **)&frame_header);
+
+	word_cnt = sizeof(struct ssp_frame_hdr) / sizeof(u32);
+	sci_swab32_cpy(&ssp_hdr, frame_header, word_cnt);
+
+	if (ssp_hdr.frame_type == SSP_RESPONSE) {
+		struct ssp_response_iu *resp_iu;
+		ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);
+
+		status = scic_sds_unsolicited_frame_control_get_buffer(
+			&(scic_sds_request_get_controller(sci_req)->uf_control),
+			frame_index,
+			(void **)&resp_iu);
+
+		sci_swab32_cpy(&sci_req->ssp.rsp,
+			       resp_iu, word_cnt);
+
+		resp_iu = &sci_req->ssp.rsp;
+
+		if ((resp_iu->datapres == 0x01) ||
+		    (resp_iu->datapres == 0x02)) {
+			scic_sds_request_set_status(
+				sci_req,
+				SCU_TASK_DONE_CHECK_RESPONSE,
+				SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR);
+		} else
+			scic_sds_request_set_status(
+				sci_req, SCU_TASK_DONE_GOOD, SCI_SUCCESS);
 	} else {
-		/* The request did not really start in the
-		 * hardware, so clear the request handle
-		 * here so no terminations will be done.
-		 */
-		request->terminated = true;
+		/* This was not a response frame why did it get forwarded? */
+		dev_err(scic_to_dev(sci_req->owning_controller),
+			"%s: SCIC IO Request 0x%p received unexpected "
+			"frame %d type 0x%02x\n",
+			__func__,
+			sci_req,
+			frame_index,
+			ssp_hdr.frame_type);
 	}
-	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
 
-	if (status ==
-	    SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
-		/* Signal libsas that we need the SCSI error
-		* handler thread to work on this I/O and that
-		* we want a device reset.
-		*/
-		spin_lock_irqsave(&task->task_state_lock, flags);
-		task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
-		spin_unlock_irqrestore(&task->task_state_lock, flags);
+	/*
+	 * In any case we are done with this frame buffer return it to the
+	 * controller
+	 */
+	scic_sds_controller_release_frame(
+		sci_req->owning_controller, frame_index);
 
-		/* Cause this task to be scheduled in the SCSI error
-		* handler thread.
-		*/
-		isci_execpath_callback(isci_host, task,
-				       sas_task_abort);
+	return SCI_SUCCESS;
+}
 
-		/* Change the status, since we are holding
-		* the I/O until it is managed by the SCSI
-		* error handler.
-		*/
-		status = SCI_SUCCESS;
+/*
+ * *****************************************************************************
+ * *  COMPLETED STATE HANDLERS
+ * ***************************************************************************** */
+
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_complete() request. This method frees up
+ * any io request resources that have been allocated and transitions the
+ * request to its final state. Consider stopping the state machine instead of
+ * transitioning to the final state? enum sci_status SCI_SUCCESS
+ */
+static enum sci_status scic_sds_request_completed_state_complete_handler(
+	struct scic_sds_request *request)
+{
+	if (request->was_tag_assigned_by_user != true) {
+		scic_controller_free_io_tag(
+			request->owning_controller, request->io_tag);
 	}
 
- out:
-	if (status != SCI_SUCCESS) {
-		/* release dma memory on failure. */
-		isci_request_free(isci_host, request);
-		request = NULL;
-		ret = SCI_FAILURE;
+	if (request->saved_rx_frame_index != SCU_INVALID_FRAME_INDEX) {
+		scic_sds_controller_release_frame(
+			request->owning_controller, request->saved_rx_frame_index);
 	}
 
-	*isci_request = request;
-	return ret;
+	sci_base_state_machine_change_state(&request->state_machine,
+		SCI_BASE_REQUEST_STATE_FINAL);
+	return SCI_SUCCESS;
+}
+
+/*
+ * *****************************************************************************
+ * *  ABORTING STATE HANDLERS
+ * ***************************************************************************** */
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_terminate() request. This method is the
+ * io request aborting state abort handlers.  On receipt of a multiple
+ * terminate requests the io request will transition to the completed state.
+ * This should not happen in normal operation. enum sci_status SCI_SUCCESS
+ */
+static enum sci_status scic_sds_request_aborting_state_abort_handler(
+	struct scic_sds_request *request)
+{
+	sci_base_state_machine_change_state(&request->state_machine,
+		SCI_BASE_REQUEST_STATE_COMPLETED);
+	return SCI_SUCCESS;
+}
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_task_completion() request. This method
+ * decodes the completion type waiting for the abort task complete
+ * notification. When the abort task complete is received the io request
+ * transitions to the completed state. enum sci_status SCI_SUCCESS
+ */
+static enum sci_status scic_sds_request_aborting_state_tc_completion_handler(
+	struct scic_sds_request *sci_req,
+	u32 completion_code)
+{
+	switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
+	case (SCU_TASK_DONE_GOOD << SCU_COMPLETION_TL_STATUS_SHIFT):
+	case (SCU_TASK_DONE_TASK_ABORT << SCU_COMPLETION_TL_STATUS_SHIFT):
+		scic_sds_request_set_status(
+			sci_req, SCU_TASK_DONE_TASK_ABORT, SCI_FAILURE_IO_TERMINATED
+			);
+
+		sci_base_state_machine_change_state(&sci_req->state_machine,
+			SCI_BASE_REQUEST_STATE_COMPLETED);
+		break;
+
+	default:
+		/*
+		 * Unless we get some strange error wait for the task abort to complete
+		 * TODO: Should there be a state change for this completion? */
+		break;
+	}
+
+	return SCI_SUCCESS;
+}
+
+/*
+ * This method implements the action to be taken when an SCIC_SDS_IO_REQUEST_T
+ * object receives a scic_sds_request_frame_handler() request. This method
+ * discards the unsolicited frame since we are waiting for the abort task
+ * completion. enum sci_status SCI_SUCCESS
+ */
+static enum sci_status scic_sds_request_aborting_state_frame_handler(
+	struct scic_sds_request *sci_req,
+	u32 frame_index)
+{
+	/* TODO: Is it even possible to get an unsolicited frame in the aborting state? */
+
+	scic_sds_controller_release_frame(
+		sci_req->owning_controller, frame_index);
+
+	return SCI_SUCCESS;
 }
 
+static const struct scic_sds_io_request_state_handler scic_sds_request_state_handler_table[] = {
+	[SCI_BASE_REQUEST_STATE_INITIAL] = {
+	},
+	[SCI_BASE_REQUEST_STATE_CONSTRUCTED] = {
+		.start_handler		= scic_sds_request_constructed_state_start_handler,
+		.abort_handler		= scic_sds_request_constructed_state_abort_handler,
+	},
+	[SCI_BASE_REQUEST_STATE_STARTED] = {
+		.abort_handler		= scic_sds_request_started_state_abort_handler,
+		.tc_completion_handler	= scic_sds_request_started_state_tc_completion_handler,
+		.frame_handler		= scic_sds_request_started_state_frame_handler,
+	},
+	[SCI_BASE_REQUEST_STATE_COMPLETED] = {
+		.complete_handler	= scic_sds_request_completed_state_complete_handler,
+	},
+	[SCI_BASE_REQUEST_STATE_ABORTING] = {
+		.abort_handler		= scic_sds_request_aborting_state_abort_handler,
+		.tc_completion_handler	= scic_sds_request_aborting_state_tc_completion_handler,
+		.frame_handler		= scic_sds_request_aborting_state_frame_handler,
+	},
+	[SCI_BASE_REQUEST_STATE_FINAL] = {
+	},
+};
+
 
 /**
  * isci_request_process_response_iu() - This function sets the status and
@@ -541,7 +1262,7 @@ static void isci_request_handle_controller_specific_errors(
 {
 	unsigned int cstatus;
 
-	cstatus = scic_request_get_controller_status(&request->sci);
+	cstatus = request->sci.scu_status;
 
 	dev_dbg(&request->isci_host->pdev->dev,
 		"%s: %p SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR "
@@ -833,20 +1554,9 @@ static void isci_task_save_for_upper_layer_completion(
 	}
 }
 
-/**
- * isci_request_io_request_complete() - This function is called by the sci core
- *    when an io 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_request_io_request_complete(
-	struct        isci_host *isci_host,
-	struct        isci_request *request,
-	enum sci_io_status completion_status)
+static void isci_request_io_request_complete(struct isci_host *isci_host,
+					     struct isci_request *request,
+					     enum sci_io_status completion_status)
 {
 	struct sas_task *task = isci_request_access_task(request);
 	struct ssp_response_iu *resp_iu;
@@ -1035,8 +1745,7 @@ void isci_request_io_request_complete(
 				 * There is a possibility that less data than
 				 * the maximum was transferred.
 				 */
-				u32 transferred_length
-					= scic_io_request_get_number_of_bytes_transferred(&request->sci);
+				u32 transferred_length = sci_req_tx_bytes(&request->sci);
 
 				task->task_status.residual
 					= task->total_xfer_len - transferred_length;
@@ -1158,3 +1867,680 @@ void isci_request_io_request_complete(
 
 	isci_host_can_dequeue(isci_host, 1);
 }
+
+/**
+ * scic_sds_request_initial_state_enter() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_INITIAL state. This state is entered when the initial
+ * base request is constructed. Entry into the initial state sets all handlers
+ * for the io request object to their default handlers. none
+ */
+static void scic_sds_request_initial_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	SET_STATE_HANDLER(
+		sci_req,
+		scic_sds_request_state_handler_table,
+		SCI_BASE_REQUEST_STATE_INITIAL
+		);
+}
+
+/**
+ * scic_sds_request_constructed_state_enter() -
+ * @object: The io request object that is to enter the constructed state.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_CONSTRUCTED state. The method sets the state handlers
+ * for the the constructed state. none
+ */
+static void scic_sds_request_constructed_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	SET_STATE_HANDLER(
+		sci_req,
+		scic_sds_request_state_handler_table,
+		SCI_BASE_REQUEST_STATE_CONSTRUCTED
+		);
+}
+
+/**
+ * scic_sds_request_started_state_enter() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.  This is cast into a SCIC_SDS_IO_REQUEST object.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_STARTED state. If the io request object type is a
+ * SCSI Task request we must enter the started substate machine. none
+ */
+static void scic_sds_request_started_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	SET_STATE_HANDLER(
+		sci_req,
+		scic_sds_request_state_handler_table,
+		SCI_BASE_REQUEST_STATE_STARTED
+		);
+
+	/*
+	 * Most of the request state machines have a started substate machine so
+	 * start its execution on the entry to the started state. */
+	if (sci_req->has_started_substate_machine == true)
+		sci_base_state_machine_start(&sci_req->started_substate_machine);
+}
+
+/**
+ * scic_sds_request_started_state_exit() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.  This object is cast into a SCIC_SDS_IO_REQUEST
+ *    object.
+ *
+ * This method implements the actions taken when exiting the
+ * SCI_BASE_REQUEST_STATE_STARTED state. For task requests the action will be
+ * to stop the started substate machine. none
+ */
+static void scic_sds_request_started_state_exit(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	if (sci_req->has_started_substate_machine == true)
+		sci_base_state_machine_stop(&sci_req->started_substate_machine);
+}
+
+/**
+ * scic_sds_request_completed_state_enter() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.  This object is cast into a SCIC_SDS_IO_REQUEST
+ *    object.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_COMPLETED state.  This state is entered when the
+ * SCIC_SDS_IO_REQUEST has completed.  The method will decode the request
+ * completion status and convert it to an enum sci_status to return in the
+ * completion callback function. none
+ */
+static void scic_sds_request_completed_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+	struct scic_sds_controller *scic =
+		scic_sds_request_get_controller(sci_req);
+	struct isci_host *ihost = scic_to_ihost(scic);
+	struct isci_request *ireq = sci_req_to_ireq(sci_req);
+
+	SET_STATE_HANDLER(sci_req,
+			  scic_sds_request_state_handler_table,
+			  SCI_BASE_REQUEST_STATE_COMPLETED);
+
+	/* Tell the SCI_USER that the IO request is complete */
+	if (sci_req->is_task_management_request == false)
+		isci_request_io_request_complete(ihost, ireq,
+						 sci_req->sci_status);
+	else
+		isci_task_request_complete(ihost, ireq, sci_req->sci_status);
+}
+
+/**
+ * scic_sds_request_aborting_state_enter() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.  This object is cast into a SCIC_SDS_IO_REQUEST
+ *    object.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_ABORTING state. none
+ */
+static void scic_sds_request_aborting_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	/* Setting the abort bit in the Task Context is required by the silicon. */
+	sci_req->task_context_buffer->abort = 1;
+
+	SET_STATE_HANDLER(
+		sci_req,
+		scic_sds_request_state_handler_table,
+		SCI_BASE_REQUEST_STATE_ABORTING
+		);
+}
+
+/**
+ * scic_sds_request_final_state_enter() -
+ * @object: This parameter specifies the base object for which the state
+ *    transition is occurring.  This is cast into a SCIC_SDS_IO_REQUEST object.
+ *
+ * This method implements the actions taken when entering the
+ * SCI_BASE_REQUEST_STATE_FINAL state. The only action required is to put the
+ * state handlers in place. none
+ */
+static void scic_sds_request_final_state_enter(void *object)
+{
+	struct scic_sds_request *sci_req = object;
+
+	SET_STATE_HANDLER(
+		sci_req,
+		scic_sds_request_state_handler_table,
+		SCI_BASE_REQUEST_STATE_FINAL
+		);
+}
+
+static const struct sci_base_state scic_sds_request_state_table[] = {
+	[SCI_BASE_REQUEST_STATE_INITIAL] = {
+		.enter_state = scic_sds_request_initial_state_enter,
+	},
+	[SCI_BASE_REQUEST_STATE_CONSTRUCTED] = {
+		.enter_state = scic_sds_request_constructed_state_enter,
+	},
+	[SCI_BASE_REQUEST_STATE_STARTED] = {
+		.enter_state = scic_sds_request_started_state_enter,
+		.exit_state  = scic_sds_request_started_state_exit
+	},
+	[SCI_BASE_REQUEST_STATE_COMPLETED] = {
+		.enter_state = scic_sds_request_completed_state_enter,
+	},
+	[SCI_BASE_REQUEST_STATE_ABORTING] = {
+		.enter_state = scic_sds_request_aborting_state_enter,
+	},
+	[SCI_BASE_REQUEST_STATE_FINAL] = {
+		.enter_state = scic_sds_request_final_state_enter,
+	},
+};
+
+static void scic_sds_general_request_construct(struct scic_sds_controller *scic,
+					       struct scic_sds_remote_device *sci_dev,
+					       u16 io_tag, struct scic_sds_request *sci_req)
+{
+	sci_base_state_machine_construct(&sci_req->state_machine, sci_req,
+			scic_sds_request_state_table, SCI_BASE_REQUEST_STATE_INITIAL);
+	sci_base_state_machine_start(&sci_req->state_machine);
+
+	sci_req->io_tag = io_tag;
+	sci_req->owning_controller = scic;
+	sci_req->target_device = sci_dev;
+	sci_req->has_started_substate_machine = false;
+	sci_req->protocol = SCIC_NO_PROTOCOL;
+	sci_req->saved_rx_frame_index = SCU_INVALID_FRAME_INDEX;
+	sci_req->device_sequence = scic_sds_remote_device_get_sequence(sci_dev);
+
+	sci_req->sci_status   = SCI_SUCCESS;
+	sci_req->scu_status   = 0;
+	sci_req->post_context = 0xFFFFFFFF;
+
+	sci_req->is_task_management_request = false;
+
+	if (io_tag == SCI_CONTROLLER_INVALID_IO_TAG) {
+		sci_req->was_tag_assigned_by_user = false;
+		sci_req->task_context_buffer = NULL;
+	} else {
+		sci_req->was_tag_assigned_by_user = true;
+
+		sci_req->task_context_buffer =
+			scic_sds_controller_get_task_context_buffer(scic, io_tag);
+	}
+}
+
+static enum sci_status
+scic_io_request_construct(struct scic_sds_controller *scic,
+			  struct scic_sds_remote_device *sci_dev,
+			  u16 io_tag, struct scic_sds_request *sci_req)
+{
+	struct domain_device *dev = sci_dev_to_domain(sci_dev);
+	enum sci_status status = SCI_SUCCESS;
+
+	/* Build the common part of the request */
+	scic_sds_general_request_construct(scic, sci_dev, io_tag, sci_req);
+
+	if (sci_dev->rnc.remote_node_index ==
+			SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
+		return SCI_FAILURE_INVALID_REMOTE_DEVICE;
+
+	if (dev->dev_type == SAS_END_DEV)
+		scic_sds_ssp_io_request_assign_buffers(sci_req);
+	else if ((dev->dev_type == SATA_DEV) ||
+		 (dev->tproto & SAS_PROTOCOL_STP)) {
+		scic_sds_stp_request_assign_buffers(sci_req);
+		memset(&sci_req->stp.cmd, 0, sizeof(sci_req->stp.cmd));
+	} else if (dev_is_expander(dev)) {
+		scic_sds_smp_request_assign_buffers(sci_req);
+		memset(&sci_req->smp.cmd, 0, sizeof(sci_req->smp.cmd));
+	} else
+		status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
+
+	if (status == SCI_SUCCESS) {
+		memset(sci_req->task_context_buffer, 0,
+		       offsetof(struct scu_task_context, sgl_pair_ab));
+	}
+
+	return status;
+}
+
+enum sci_status scic_task_request_construct(struct scic_sds_controller *scic,
+					    struct scic_sds_remote_device *sci_dev,
+					    u16 io_tag, struct scic_sds_request *sci_req)
+{
+	struct domain_device *dev = sci_dev_to_domain(sci_dev);
+	enum sci_status status = SCI_SUCCESS;
+
+	/* Build the common part of the request */
+	scic_sds_general_request_construct(scic, sci_dev, io_tag, sci_req);
+
+	if (dev->dev_type == SAS_END_DEV) {
+		scic_sds_ssp_task_request_assign_buffers(sci_req);
+
+		sci_req->has_started_substate_machine = true;
+
+		/* Construct the started sub-state machine. */
+		sci_base_state_machine_construct(
+			&sci_req->started_substate_machine,
+			sci_req,
+			scic_sds_io_request_started_task_mgmt_substate_table,
+			SCIC_SDS_IO_REQUEST_STARTED_TASK_MGMT_SUBSTATE_AWAIT_TC_COMPLETION
+			);
+	} else if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP))
+		scic_sds_stp_request_assign_buffers(sci_req);
+	else
+		status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
+
+	if (status == SCI_SUCCESS) {
+		sci_req->is_task_management_request = true;
+		memset(sci_req->task_context_buffer, 0, sizeof(struct scu_task_context));
+	}
+
+	return status;
+}
+
+static enum sci_status isci_request_ssp_request_construct(
+	struct isci_request *request)
+{
+	enum sci_status status;
+
+	dev_dbg(&request->isci_host->pdev->dev,
+		"%s: request = %p\n",
+		__func__,
+		request);
+	status = scic_io_request_construct_basic_ssp(&request->sci);
+	return status;
+}
+
+static enum sci_status isci_request_stp_request_construct(
+	struct isci_request *request)
+{
+	struct sas_task *task = isci_request_access_task(request);
+	enum sci_status status;
+	struct host_to_dev_fis *register_fis;
+
+	dev_dbg(&request->isci_host->pdev->dev,
+		"%s: request = %p\n",
+		__func__,
+		request);
+
+	/* Get the host_to_dev_fis from the core and copy
+	 * the fis from the task into it.
+	 */
+	register_fis = isci_sata_task_to_fis_copy(task);
+
+	status = scic_io_request_construct_basic_sata(&request->sci);
+
+	/* Set the ncq tag in the fis, from the queue
+	 * command in the task.
+	 */
+	if (isci_sata_is_task_ncq(task)) {
+
+		isci_sata_set_ncq_tag(
+			register_fis,
+			task
+			);
+	}
+
+	return status;
+}
+
+/*
+ * isci_smp_request_build() - This function builds the smp request.
+ * @ireq: This parameter points to the isci_request allocated in the
+ *    request construct function.
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+static enum sci_status isci_smp_request_build(struct isci_request *ireq)
+{
+	enum sci_status status = SCI_FAILURE;
+	struct sas_task *task = isci_request_access_task(ireq);
+	struct scic_sds_request *sci_req = &ireq->sci;
+
+	dev_dbg(&ireq->isci_host->pdev->dev,
+		"%s: request = %p\n", __func__, ireq);
+
+	dev_dbg(&ireq->isci_host->pdev->dev,
+		"%s: smp_req len = %d\n",
+		__func__,
+		task->smp_task.smp_req.length);
+
+	/* copy the smp_command to the address; */
+	sg_copy_to_buffer(&task->smp_task.smp_req, 1,
+			  &sci_req->smp.cmd,
+			  sizeof(struct smp_req));
+
+	status = scic_io_request_construct_smp(sci_req);
+	if (status != SCI_SUCCESS)
+		dev_warn(&ireq->isci_host->pdev->dev,
+			 "%s: failed with status = %d\n",
+			 __func__,
+			 status);
+
+	return status;
+}
+
+/**
+ * isci_io_request_build() - This function builds the io 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.
+ * @sci_device: This parameter is the handle for the sci core's remote device
+ *    object that is the destination for this request.
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+static enum sci_status isci_io_request_build(
+	struct isci_host *isci_host,
+	struct isci_request *request,
+	struct isci_remote_device *isci_device)
+{
+	enum sci_status status = SCI_SUCCESS;
+	struct sas_task *task = isci_request_access_task(request);
+	struct scic_sds_remote_device *sci_device = &isci_device->sci;
+
+	dev_dbg(&isci_host->pdev->dev,
+		"%s: isci_device = 0x%p; request = %p, "
+		"num_scatter = %d\n",
+		__func__,
+		isci_device,
+		request,
+		task->num_scatter);
+
+	/* map the sgl addresses, if present.
+	 * libata does the mapping for sata devices
+	 * before we get the request.
+	 */
+	if (task->num_scatter &&
+	    !sas_protocol_ata(task->task_proto) &&
+	    !(SAS_PROTOCOL_SMP & task->task_proto)) {
+
+		request->num_sg_entries = dma_map_sg(
+			&isci_host->pdev->dev,
+			task->scatter,
+			task->num_scatter,
+			task->data_dir
+			);
+
+		if (request->num_sg_entries == 0)
+			return SCI_FAILURE_INSUFFICIENT_RESOURCES;
+	}
+
+	/* build the common request object. For now,
+	 * we will let the core allocate the IO tag.
+	 */
+	status = scic_io_request_construct(&isci_host->sci, sci_device,
+					   SCI_CONTROLLER_INVALID_IO_TAG,
+					   &request->sci);
+
+	if (status != SCI_SUCCESS) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: failed request construct\n",
+			 __func__);
+		return SCI_FAILURE;
+	}
+
+	switch (task->task_proto) {
+	case SAS_PROTOCOL_SMP:
+		status = isci_smp_request_build(request);
+		break;
+	case SAS_PROTOCOL_SSP:
+		status = isci_request_ssp_request_construct(request);
+		break;
+	case SAS_PROTOCOL_SATA:
+	case SAS_PROTOCOL_STP:
+	case SAS_PROTOCOL_SATA | SAS_PROTOCOL_STP:
+		status = isci_request_stp_request_construct(request);
+		break;
+	default:
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: unknown protocol\n", __func__);
+		return SCI_FAILURE;
+	}
+
+	return SCI_SUCCESS;
+}
+
+/**
+ * isci_request_alloc_core() - This function gets the request object from the
+ *    isci_host dma cache.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @isci_request: This parameter will contain the pointer to the new
+ *    isci_request object.
+ * @isci_device: This parameter is the pointer to the isci remote device object
+ *    that is the destination for this request.
+ * @gfp_flags: This parameter specifies the os allocation flags.
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+static int isci_request_alloc_core(
+	struct isci_host *isci_host,
+	struct isci_request **isci_request,
+	struct isci_remote_device *isci_device,
+	gfp_t gfp_flags)
+{
+	int ret = 0;
+	dma_addr_t handle;
+	struct isci_request *request;
+
+
+	/* get pointer to dma memory. This actually points
+	 * to both the isci_remote_device object and the
+	 * sci object. The isci object is at the beginning
+	 * of the memory allocated here.
+	 */
+	request = dma_pool_alloc(isci_host->dma_pool, gfp_flags, &handle);
+	if (!request) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: dma_pool_alloc returned NULL\n", __func__);
+		return -ENOMEM;
+	}
+
+	/* initialize the request object.	*/
+	spin_lock_init(&request->state_lock);
+	request->request_daddr = handle;
+	request->isci_host = isci_host;
+	request->isci_device = isci_device;
+	request->io_request_completion = NULL;
+	request->terminated = false;
+
+	request->num_sg_entries = 0;
+
+	request->complete_in_target = false;
+
+	INIT_LIST_HEAD(&request->completed_node);
+	INIT_LIST_HEAD(&request->dev_node);
+
+	*isci_request = request;
+	isci_request_change_state(request, allocated);
+
+	return ret;
+}
+
+static int isci_request_alloc_io(
+	struct isci_host *isci_host,
+	struct sas_task *task,
+	struct isci_request **isci_request,
+	struct isci_remote_device *isci_device,
+	gfp_t gfp_flags)
+{
+	int retval = isci_request_alloc_core(isci_host, isci_request,
+					     isci_device, gfp_flags);
+
+	if (!retval) {
+		(*isci_request)->ttype_ptr.io_task_ptr = task;
+		(*isci_request)->ttype                 = io_task;
+
+		task->lldd_task = *isci_request;
+	}
+	return retval;
+}
+
+/**
+ * isci_request_alloc_tmf() - This function gets the request object from the
+ *    isci_host dma cache and initializes the relevant fields as a sas_task.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @sas_task: This parameter is the task struct from the upper layer driver.
+ * @isci_request: This parameter will contain the pointer to the new
+ *    isci_request object.
+ * @isci_device: This parameter is the pointer to the isci remote device object
+ *    that is the destination for this request.
+ * @gfp_flags: This parameter specifies the os allocation flags.
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+int isci_request_alloc_tmf(
+	struct isci_host *isci_host,
+	struct isci_tmf *isci_tmf,
+	struct isci_request **isci_request,
+	struct isci_remote_device *isci_device,
+	gfp_t gfp_flags)
+{
+	int retval = isci_request_alloc_core(isci_host, isci_request,
+					     isci_device, gfp_flags);
+
+	if (!retval) {
+
+		(*isci_request)->ttype_ptr.tmf_task_ptr = isci_tmf;
+		(*isci_request)->ttype = tmf_task;
+	}
+	return retval;
+}
+
+/**
+ * isci_request_execute() - This function allocates the isci_request object,
+ *    all fills in some common fields.
+ * @isci_host: This parameter specifies the ISCI host object
+ * @sas_task: This parameter is the task struct from the upper layer driver.
+ * @isci_request: This parameter will contain the pointer to the new
+ *    isci_request object.
+ * @gfp_flags: This parameter specifies the os allocation flags.
+ *
+ * SCI_SUCCESS on successfull completion, or specific failure code.
+ */
+int isci_request_execute(
+	struct isci_host *isci_host,
+	struct sas_task *task,
+	struct isci_request **isci_request,
+	gfp_t gfp_flags)
+{
+	int ret = 0;
+	struct scic_sds_remote_device *sci_device;
+	enum sci_status status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
+	struct isci_remote_device *isci_device;
+	struct isci_request *request;
+	unsigned long flags;
+
+	isci_device = task->dev->lldd_dev;
+	sci_device = &isci_device->sci;
+
+	/* do common allocation and init of request object. */
+	ret = isci_request_alloc_io(
+		isci_host,
+		task,
+		&request,
+		isci_device,
+		gfp_flags
+		);
+
+	if (ret)
+		goto out;
+
+	status = isci_io_request_build(isci_host, request, isci_device);
+	if (status != SCI_SUCCESS) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: request_construct failed - status = 0x%x\n",
+			 __func__,
+			 status);
+		goto out;
+	}
+
+	spin_lock_irqsave(&isci_host->scic_lock, flags);
+
+	/* send the request, let the core assign the IO TAG.	*/
+	status = scic_controller_start_io(&isci_host->sci, sci_device,
+					  &request->sci,
+					  SCI_CONTROLLER_INVALID_IO_TAG);
+	if (status != SCI_SUCCESS &&
+	    status != SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
+		dev_warn(&isci_host->pdev->dev,
+			 "%s: failed request start (0x%x)\n",
+			 __func__, status);
+		spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+		goto out;
+	}
+
+	/* Either I/O started OK, or the core has signaled that
+	 * the device needs a target reset.
+	 *
+	 * In either case, hold onto the I/O for later.
+	 *
+	 * Update it's status and add it to the list in the
+	 * remote device object.
+	 */
+	isci_request_change_state(request, started);
+	list_add(&request->dev_node, &isci_device->reqs_in_process);
+
+	if (status == SCI_SUCCESS) {
+		/* Save the tag for possible task mgmt later. */
+		request->io_tag = request->sci.io_tag;
+	} else {
+		/* The request did not really start in the
+		 * hardware, so clear the request handle
+		 * here so no terminations will be done.
+		 */
+		request->terminated = true;
+	}
+	spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+
+	if (status ==
+	    SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
+		/* Signal libsas that we need the SCSI error
+		* handler thread to work on this I/O and that
+		* we want a device reset.
+		*/
+		spin_lock_irqsave(&task->task_state_lock, flags);
+		task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
+		spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+		/* Cause this task to be scheduled in the SCSI error
+		* handler thread.
+		*/
+		isci_execpath_callback(isci_host, task,
+				       sas_task_abort);
+
+		/* Change the status, since we are holding
+		* the I/O until it is managed by the SCSI
+		* error handler.
+		*/
+		status = SCI_SUCCESS;
+	}
+
+ out:
+	if (status != SCI_SUCCESS) {
+		/* release dma memory on failure. */
+		isci_request_free(isci_host, request);
+		request = NULL;
+		ret = SCI_FAILURE;
+	}
+
+	*isci_request = request;
+	return ret;
+}
+
+
+