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

#include <scsi/scsi_cmnd.h>
#include "isci.h"
#include "task.h"
#include "request.h"
#include "scu_completion_codes.h"
#include "scu_event_codes.h"
#include "sas.h"

#undef C
#define C(a) (#a)
const char *req_state_name(enum sci_base_request_states state)
{
        static const char * const strings[] = REQUEST_STATES;

        return strings[state];
}
#undef C

static struct scu_sgl_element_pair *to_sgl_element_pair(struct isci_request *ireq,
                                                        int idx)
{
        if (idx == 0)
                return &ireq->tc->sgl_pair_ab;
        else if (idx == 1)
                return &ireq->tc->sgl_pair_cd;
        else if (idx < 0)
                return NULL;
        else
                return &ireq->sg_table[idx - 2];
}

static dma_addr_t to_sgl_element_pair_dma(struct isci_host *ihost,
                                          struct isci_request *ireq, u32 idx)
{
        u32 offset;

        if (idx == 0) {
                offset = (void *) &ireq->tc->sgl_pair_ab -
                         (void *) &ihost->task_context_table[0];
                return ihost->tc_dma + offset;
        } else if (idx == 1) {
                offset = (void *) &ireq->tc->sgl_pair_cd -
                         (void *) &ihost->task_context_table[0];
                return ihost->tc_dma + offset;
        }

        return sci_io_request_get_dma_addr(ireq, &ireq->sg_table[idx - 2]);
}

static void init_sgl_element(struct scu_sgl_element *e, struct scatterlist *sg)
{
        e->length = sg_dma_len(sg);
        e->address_upper = upper_32_bits(sg_dma_address(sg));
        e->address_lower = lower_32_bits(sg_dma_address(sg));
        e->address_modifier = 0;
}

static void sci_request_build_sgl(struct isci_request *ireq)
{
        struct isci_host *ihost = ireq->isci_host;
        struct sas_task *task = isci_request_access_task(ireq);
        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 = to_sgl_element_pair(ireq, sg_idx);
                        init_sgl_element(&scu_sg->A, sg);
                        sg = sg_next(sg);
                        if (sg) {
                                init_sgl_element(&scu_sg->B, sg);
                                sg = sg_next(sg);
                        } else
                                memset(&scu_sg->B, 0, sizeof(scu_sg->B));

                        if (prev_sg) {
                                dma_addr = to_sgl_element_pair_dma(ihost,
                                                                   ireq,
                                                                   sg_idx);

                                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 = to_sgl_element_pair(ireq, sg_idx);

                dma_addr = dma_map_single(&ihost->pdev->dev,
                                          task->scatter,
                                          task->total_xfer_len,
                                          task->data_dir);

                ireq->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 void sci_io_request_build_ssp_command_iu(struct isci_request *ireq)
{
        struct ssp_cmd_iu *cmd_iu;
        struct sas_task *task = isci_request_access_task(ireq);

        cmd_iu = &ireq->ssp.cmd;

        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 = 0;
        cmd_iu->task_attr = task->ssp_task.task_attr;
        cmd_iu->_r_c = 0;

        sci_swab32_cpy(&cmd_iu->cdb, task->ssp_task.cmd->cmnd,
                       (task->ssp_task.cmd->cmd_len+3) / sizeof(u32));
}

static void sci_task_request_build_ssp_task_iu(struct isci_request *ireq)
{
        struct ssp_task_iu *task_iu;
        struct sas_task *task = isci_request_access_task(ireq);
        struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);

        task_iu = &ireq->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 =
                (test_bit(IREQ_TMF, &ireq->flags)) ?
                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.
 */
static void scu_ssp_request_construct_task_context(
        struct isci_request *ireq,
        struct scu_task_context *task_context)
{
        dma_addr_t dma_addr;
        struct isci_remote_device *idev;
        struct isci_port *iport;

        idev = ireq->target_device;
        iport = idev->owning_port;

        /* Fill in the TC with its required data */
        task_context->abort = 0;
        task_context->priority = 0;
        task_context->initiator_request = 1;
        task_context->connection_rate = idev->connection_rate;
        task_context->protocol_engine_index = ISCI_PEG;
        task_context->logical_port_index = iport->physical_port_index;
        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 = idev->rnc.remote_node_index;
        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 = ireq->io_tag; */
        task_context->task_phase = 0x01;

        ireq->post_context = (SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC |
                              (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
                              (iport->physical_port_index <<
                               SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
                              ISCI_TAG_TCI(ireq->io_tag));

        /*
         * Copy the physical address for the command buffer to the
         * SCU Task Context
         */
        dma_addr = sci_io_request_get_dma_addr(ireq, &ireq->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 = sci_io_request_get_dma_addr(ireq, &ireq->ssp.rsp);

        task_context->response_iu_upper = upper_32_bits(dma_addr);
        task_context->response_iu_lower = lower_32_bits(dma_addr);
}

static u8 scu_bg_blk_size(struct scsi_device *sdp)
{
        switch (sdp->sector_size) {
        case 512:
                return 0;
        case 1024:
                return 1;
        case 4096:
                return 3;
        default:
                return 0xff;
        }
}

static u32 scu_dif_bytes(u32 len, u32 sector_size)
{
        return (len >> ilog2(sector_size)) * 8;
}

static void scu_ssp_ireq_dif_insert(struct isci_request *ireq, u8 type, u8 op)
{
        struct scu_task_context *tc = ireq->tc;
        struct scsi_cmnd *scmd = ireq->ttype_ptr.io_task_ptr->uldd_task;
        u8 blk_sz = scu_bg_blk_size(scmd->device);

        tc->block_guard_enable = 1;
        tc->blk_prot_en = 1;
        tc->blk_sz = blk_sz;
        /* DIF write insert */
        tc->blk_prot_func = 0x2;

        tc->transfer_length_bytes += scu_dif_bytes(tc->transfer_length_bytes,
                                                   scmd->device->sector_size);

        /* always init to 0, used by hw */
        tc->interm_crc_val = 0;

        tc->init_crc_seed = 0;
        tc->app_tag_verify = 0;
        tc->app_tag_gen = 0;
        tc->ref_tag_seed_verify = 0;

        /* always init to same as bg_blk_sz */
        tc->UD_bytes_immed_val = scmd->device->sector_size;

        tc->reserved_DC_0 = 0;

        /* always init to 8 */
        tc->DIF_bytes_immed_val = 8;

        tc->reserved_DC_1 = 0;
        tc->bgc_blk_sz = scmd->device->sector_size;
        tc->reserved_E0_0 = 0;
        tc->app_tag_gen_mask = 0;

        /** setup block guard control **/
        tc->bgctl = 0;

        /* DIF write insert */
        tc->bgctl_f.op = 0x2;

        tc->app_tag_verify_mask = 0;

        /* must init to 0 for hw */
        tc->blk_guard_err = 0;

        tc->reserved_E8_0 = 0;

        if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2))
                tc->ref_tag_seed_gen = scsi_prot_ref_tag(scmd);
        else if (type & SCSI_PROT_DIF_TYPE3)
                tc->ref_tag_seed_gen = 0;
}

static void scu_ssp_ireq_dif_strip(struct isci_request *ireq, u8 type, u8 op)
{
        struct scu_task_context *tc = ireq->tc;
        struct scsi_cmnd *scmd = ireq->ttype_ptr.io_task_ptr->uldd_task;
        u8 blk_sz = scu_bg_blk_size(scmd->device);

        tc->block_guard_enable = 1;
        tc->blk_prot_en = 1;
        tc->blk_sz = blk_sz;
        /* DIF read strip */
        tc->blk_prot_func = 0x1;

        tc->transfer_length_bytes += scu_dif_bytes(tc->transfer_length_bytes,
                                                   scmd->device->sector_size);

        /* always init to 0, used by hw */
        tc->interm_crc_val = 0;

        tc->init_crc_seed = 0;
        tc->app_tag_verify = 0;
        tc->app_tag_gen = 0;

        if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2))
                tc->ref_tag_seed_verify = scsi_prot_ref_tag(scmd);
        else if (type & SCSI_PROT_DIF_TYPE3)
                tc->ref_tag_seed_verify = 0;

        /* always init to same as bg_blk_sz */
        tc->UD_bytes_immed_val = scmd->device->sector_size;

        tc->reserved_DC_0 = 0;

        /* always init to 8 */
        tc->DIF_bytes_immed_val = 8;

        tc->reserved_DC_1 = 0;
        tc->bgc_blk_sz = scmd->device->sector_size;
        tc->reserved_E0_0 = 0;
        tc->app_tag_gen_mask = 0;

        /** setup block guard control **/
        tc->bgctl = 0;

        /* DIF read strip */
        tc->bgctl_f.crc_verify = 1;
        tc->bgctl_f.op = 0x1;
        if ((type & SCSI_PROT_DIF_TYPE1) || (type & SCSI_PROT_DIF_TYPE2)) {
                tc->bgctl_f.ref_tag_chk = 1;
                tc->bgctl_f.app_f_detect = 1;
        } else if (type & SCSI_PROT_DIF_TYPE3)
                tc->bgctl_f.app_ref_f_detect = 1;

        tc->app_tag_verify_mask = 0;

        /* must init to 0 for hw */
        tc->blk_guard_err = 0;

        tc->reserved_E8_0 = 0;
        tc->ref_tag_seed_gen = 0;
}

/*
 * This method is will fill in the SCU Task Context for a SSP IO request.
 */
static void scu_ssp_io_request_construct_task_context(struct isci_request *ireq,
                                                      enum dma_data_direction dir,
                                                      u32 len)
{
        struct scu_task_context *task_context = ireq->tc;
        struct sas_task *sas_task = ireq->ttype_ptr.io_task_ptr;
        struct scsi_cmnd *scmd = sas_task->uldd_task;
        u8 prot_type = scsi_get_prot_type(scmd);
        u8 prot_op = scsi_get_prot_op(scmd);

        scu_ssp_request_construct_task_context(ireq, task_context);

        task_context->ssp_command_iu_length =
                sizeof(struct ssp_cmd_iu) / sizeof(u32);
        task_context->type.ssp.frame_type = SSP_COMMAND;

        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;
        }

        task_context->transfer_length_bytes = len;

        if (task_context->transfer_length_bytes > 0)
                sci_request_build_sgl(ireq);

        if (prot_type != SCSI_PROT_DIF_TYPE0) {
                if (prot_op == SCSI_PROT_READ_STRIP)
                        scu_ssp_ireq_dif_strip(ireq, prot_type, prot_op);
                else if (prot_op == SCSI_PROT_WRITE_INSERT)
                        scu_ssp_ireq_dif_insert(ireq, prot_type, prot_op);
        }
}

/**
 * scu_ssp_task_request_construct_task_context() - 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 endianness is set so that the bytes are
 *    transmitted in the right order for a task frame.
 * @ireq: This parameter specifies the task request object being constructed.
 */
static void scu_ssp_task_request_construct_task_context(struct isci_request *ireq)
{
        struct scu_task_context *task_context = ireq->tc;

        scu_ssp_request_construct_task_context(ireq, task_context);

        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);
}

/**
 * scu_sata_request_construct_task_context()
 * This method is will fill in the SCU Task Context for any type of SATA
 *    request.  This is called from the various SATA constructors.
 * @ireq: The general IO request object which is to be used in
 *    constructing the SCU task context.
 * @task_context: The buffer pointer for the SCU task context which is being
 *    constructed.
 *
 * The general io request construction is complete. The buffer assignment for
 * the command buffer is complete. none Revisit task context construction to
 * determine what is common for SSP/SMP/STP task context structures.
 */
static void scu_sata_request_construct_task_context(
        struct isci_request *ireq,
        struct scu_task_context *task_context)
{
        dma_addr_t dma_addr;
        struct isci_remote_device *idev;
        struct isci_port *iport;

        idev = ireq->target_device;
        iport = idev->owning_port;

        /* Fill in the TC with its required data */
        task_context->abort = 0;
        task_context->priority = SCU_TASK_PRIORITY_NORMAL;
        task_context->initiator_request = 1;
        task_context->connection_rate = idev->connection_rate;
        task_context->protocol_engine_index = ISCI_PEG;
        task_context->logical_port_index = iport->physical_port_index;
        task_context->protocol_type = SCU_TASK_CONTEXT_PROTOCOL_STP;
        task_context->valid = SCU_TASK_CONTEXT_VALID;
        task_context->context_type = SCU_TASK_CONTEXT_TYPE;

        task_context->remote_node_index = idev->rnc.remote_node_index;
        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->task_phase = 0x01;

        task_context->ssp_command_iu_length =
                (sizeof(struct host_to_dev_fis) - sizeof(u32)) / sizeof(u32);

        /* Set the first word of the H2D REG FIS */
        task_context->type.words[0] = *(u32 *)&ireq->stp.cmd;

        ireq->post_context = (SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC |
                              (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
                              (iport->physical_port_index <<
                               SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
                              ISCI_TAG_TCI(ireq->io_tag));
        /*
         * Copy the physical address for the command buffer to the SCU Task
         * Context. We must offset the command buffer by 4 bytes because the
         * first 4 bytes are transfered in the body of the TC.
         */
        dma_addr = sci_io_request_get_dma_addr(ireq,
                                                ((char *) &ireq->stp.cmd) +
                                                sizeof(u32));

        task_context->command_iu_upper = upper_32_bits(dma_addr);
        task_context->command_iu_lower = lower_32_bits(dma_addr);

        /* SATA Requests do not have a response buffer */
        task_context->response_iu_upper = 0;
        task_context->response_iu_lower = 0;
}

static void scu_stp_raw_request_construct_task_context(struct isci_request *ireq)
{
        struct scu_task_context *task_context = ireq->tc;

        scu_sata_request_construct_task_context(ireq, task_context);

        task_context->control_frame         = 0;
        task_context->priority              = SCU_TASK_PRIORITY_NORMAL;
        task_context->task_type             = SCU_TASK_TYPE_SATA_RAW_FRAME;
        task_context->type.stp.fis_type     = FIS_REGH2D;
        task_context->transfer_length_bytes = sizeof(struct host_to_dev_fis) - sizeof(u32);
}

static enum sci_status sci_stp_pio_request_construct(struct isci_request *ireq,
                                                          bool copy_rx_frame)
{
        struct isci_stp_request *stp_req = &ireq->stp.req;

        scu_stp_raw_request_construct_task_context(ireq);

        stp_req->status = 0;
        stp_req->sgl.offset = 0;
        stp_req->sgl.set = SCU_SGL_ELEMENT_PAIR_A;

        if (copy_rx_frame) {
                sci_request_build_sgl(ireq);
                stp_req->sgl.index = 0;
        } else {
                /* The user does not want the data copied to the SGL buffer location */
                stp_req->sgl.index = -1;
        }

        return SCI_SUCCESS;
}

/*
 * sci_stp_optimized_request_construct()
 * @ireq: This parameter specifies the request to be constructed as an
 *    optimized request.
 * @optimized_task_type: This parameter specifies whether the request is to be
 *    an UDMA request or a NCQ request. - A value of 0 indicates UDMA. - A
 *    value of 1 indicates NCQ.
 *
 * This method will perform request construction common to all types of STP
 * requests that are optimized by the silicon (i.e. UDMA, NCQ). This method
 * returns an indication as to whether the construction was successful.
 */
static void sci_stp_optimized_request_construct(struct isci_request *ireq,
                                                     u8 optimized_task_type,
                                                     u32 len,
                                                     enum dma_data_direction dir)
{
        struct scu_task_context *task_context = ireq->tc;

        /* Build the STP task context structure */
        scu_sata_request_construct_task_context(ireq, task_context);

        /* Copy over the SGL elements */
        sci_request_build_sgl(ireq);

        /* Copy over the number of bytes to be transfered */
        task_context->transfer_length_bytes = len;

        if (dir == DMA_TO_DEVICE) {
                /*
                 * The difference between the DMA IN and DMA OUT request task type
                 * values are consistent with the difference between FPDMA READ
                 * and FPDMA WRITE values.  Add the supplied task type parameter
                 * to this difference to set the task type properly for this
                 * DATA OUT (WRITE) case. */
                task_context->task_type = optimized_task_type + (SCU_TASK_TYPE_DMA_OUT
                                                                 - SCU_TASK_TYPE_DMA_IN);
        } else {
                /*
                 * For the DATA IN (READ) case, simply save the supplied
                 * optimized task type. */
                task_context->task_type = optimized_task_type;
        }
}

static void sci_atapi_construct(struct isci_request *ireq)
{
        struct host_to_dev_fis *h2d_fis = &ireq->stp.cmd;
        struct sas_task *task;

        /* To simplify the implementation we take advantage of the
         * silicon's partial acceleration of atapi protocol (dma data
         * transfers), so we promote all commands to dma protocol.  This
         * breaks compatibility with ATA_HORKAGE_ATAPI_MOD16_DMA drives.
         */
        h2d_fis->features |= ATAPI_PKT_DMA;

        scu_stp_raw_request_construct_task_context(ireq);

        task = isci_request_access_task(ireq);
        if (task->data_dir == DMA_NONE)
                task->total_xfer_len = 0;

        /* clear the response so we can detect arrivial of an
         * unsolicited h2d fis
         */
        ireq->stp.rsp.fis_type = 0;
}

static enum sci_status
sci_io_request_construct_sata(struct isci_request *ireq,
                               u32 len,
                               enum dma_data_direction dir,
                               bool copy)
{
        enum sci_status status = SCI_SUCCESS;
        struct sas_task *task = isci_request_access_task(ireq);
        struct domain_device *dev = ireq->target_device->domain_dev;

        /* check for management protocols */
        if (test_bit(IREQ_TMF, &ireq->flags)) {
                struct isci_tmf *tmf = isci_request_access_tmf(ireq);

                dev_err(&ireq->owning_controller->pdev->dev,
                        "%s: Request 0x%p received un-handled SAT "
                        "management protocol 0x%x.\n",
                        __func__, ireq, tmf->tmf_code);

                return SCI_FAILURE;
        }

        if (!sas_protocol_ata(task->task_proto)) {
                dev_err(&ireq->owning_controller->pdev->dev,
                        "%s: Non-ATA protocol in SATA path: 0x%x\n",
                        __func__,
                        task->task_proto);
                return SCI_FAILURE;

        }

        /* ATAPI */
        if (dev->sata_dev.class == ATA_DEV_ATAPI &&
            task->ata_task.fis.command == ATA_CMD_PACKET) {
                sci_atapi_construct(ireq);
                return SCI_SUCCESS;
        }

        /* non data */
        if (task->data_dir == DMA_NONE) {
                scu_stp_raw_request_construct_task_context(ireq);
                return SCI_SUCCESS;
        }

        /* NCQ */
        if (task->ata_task.use_ncq) {
                sci_stp_optimized_request_construct(ireq,
                                                         SCU_TASK_TYPE_FPDMAQ_READ,
                                                         len, dir);
                return SCI_SUCCESS;
        }

        /* DMA */
        if (task->ata_task.dma_xfer) {
                sci_stp_optimized_request_construct(ireq,
                                                         SCU_TASK_TYPE_DMA_IN,
                                                         len, dir);
                return SCI_SUCCESS;
        } else /* PIO */
                return sci_stp_pio_request_construct(ireq, copy);

        return status;
}

static enum sci_status sci_io_request_construct_basic_ssp(struct isci_request *ireq)
{
        struct sas_task *task = isci_request_access_task(ireq);

        ireq->protocol = SAS_PROTOCOL_SSP;

        scu_ssp_io_request_construct_task_context(ireq,
                                                  task->data_dir,
                                                  task->total_xfer_len);

        sci_io_request_build_ssp_command_iu(ireq);

        sci_change_state(&ireq->sm, SCI_REQ_CONSTRUCTED);

        return SCI_SUCCESS;
}

void sci_task_request_construct_ssp(struct isci_request *ireq)
{
        /* Construct the SSP Task SCU Task Context */
        scu_ssp_task_request_construct_task_context(ireq);

        /* Fill in the SSP Task IU */
        sci_task_request_build_ssp_task_iu(ireq);

        sci_change_state(&ireq->sm, SCI_REQ_CONSTRUCTED);
}

static enum sci_status sci_io_request_construct_basic_sata(struct isci_request *ireq)
{
        enum sci_status status;
        bool copy = false;
        struct sas_task *task = isci_request_access_task(ireq);

        ireq->protocol = SAS_PROTOCOL_STP;

        copy = (task->data_dir == DMA_NONE) ? false : true;

        status = sci_io_request_construct_sata(ireq,
                                                task->total_xfer_len,
                                                task->data_dir,
                                                copy);

        if (status == SCI_SUCCESS)
                sci_change_state(&ireq->sm, SCI_REQ_CONSTRUCTED);

        return status;
}

#define SCU_TASK_CONTEXT_SRAM 0x200000
/**
 * sci_req_tx_bytes - bytes transferred when reply underruns request
 * @ireq: request that was terminated early
 */
static u32 sci_req_tx_bytes(struct isci_request *ireq)
{
        struct isci_host *ihost = ireq->owning_controller;
        u32 ret_val = 0;

        if (readl(&ihost->smu_registers->address_modifier) == 0) {
                void __iomem *scu_reg_base = ihost->scu_registers;

                /* 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 sci_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)) * ISCI_TAG_TCI(ireq->io_tag)));
        }

        return ret_val;
}

enum sci_status sci_request_start(struct isci_request *ireq)
{
        enum sci_base_request_states state;
        struct scu_task_context *tc = ireq->tc;
        struct isci_host *ihost = ireq->owning_controller;

        state = ireq->sm.current_state_id;
        if (state != SCI_REQ_CONSTRUCTED) {
                dev_warn(&ihost->pdev->dev,
                        "%s: SCIC IO Request requested to start while in wrong "
                         "state %d\n", __func__, state);
                return SCI_FAILURE_INVALID_STATE;
        }

        tc->task_index = ISCI_TAG_TCI(ireq->io_tag);

        switch (tc->protocol_type) {
        case SCU_TASK_CONTEXT_PROTOCOL_SMP:
        case SCU_TASK_CONTEXT_PROTOCOL_SSP:
                /* SSP/SMP Frame */
                tc->type.ssp.tag = ireq->io_tag;
                tc->type.ssp.target_port_transfer_tag = 0xFFFF;
                break;

        case SCU_TASK_CONTEXT_PROTOCOL_STP:
                /* STP/SATA Frame
                 * tc->type.stp.ncq_tag = ireq->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;
        }

        /* Add to the post_context the io tag value */
        ireq->post_context |= ISCI_TAG_TCI(ireq->io_tag);

        /* Everything is good go ahead and change state */
        sci_change_state(&ireq->sm, SCI_REQ_STARTED);

        return SCI_SUCCESS;
}

enum sci_status
sci_io_request_terminate(struct isci_request *ireq)
{
        enum sci_base_request_states state;

        state = ireq->sm.current_state_id;

        switch (state) {
        case SCI_REQ_CONSTRUCTED:
                /* Set to make sure no HW terminate posting is done: */
                set_bit(IREQ_TC_ABORT_POSTED, &ireq->flags);
                ireq->scu_status = SCU_TASK_DONE_TASK_ABORT;
                ireq->sci_status = SCI_FAILURE_IO_TERMINATED;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                return SCI_SUCCESS;
        case SCI_REQ_STARTED:
        case SCI_REQ_TASK_WAIT_TC_COMP:
        case SCI_REQ_SMP_WAIT_RESP:
        case SCI_REQ_SMP_WAIT_TC_COMP:
        case SCI_REQ_STP_UDMA_WAIT_TC_COMP:
        case SCI_REQ_STP_UDMA_WAIT_D2H:
        case SCI_REQ_STP_NON_DATA_WAIT_H2D:
        case SCI_REQ_STP_NON_DATA_WAIT_D2H:
        case SCI_REQ_STP_PIO_WAIT_H2D:
        case SCI_REQ_STP_PIO_WAIT_FRAME:
        case SCI_REQ_STP_PIO_DATA_IN:
        case SCI_REQ_STP_PIO_DATA_OUT:
        case SCI_REQ_ATAPI_WAIT_H2D:
        case SCI_REQ_ATAPI_WAIT_PIO_SETUP:
        case SCI_REQ_ATAPI_WAIT_D2H:
        case SCI_REQ_ATAPI_WAIT_TC_COMP:
                /* Fall through and change state to ABORTING... */
        case SCI_REQ_TASK_WAIT_TC_RESP:
                /* The task frame was already confirmed to have been
                 * sent by the SCU HW.  Since the state machine is
                 * now only waiting for the task response itself,
                 * abort the request and complete it immediately
                 * and don't wait for the task response.
                 */
                sci_change_state(&ireq->sm, SCI_REQ_ABORTING);
                fallthrough;    /* and handle like ABORTING */
        case SCI_REQ_ABORTING:
                if (!isci_remote_device_is_safe_to_abort(ireq->target_device))
                        set_bit(IREQ_PENDING_ABORT, &ireq->flags);
                else
                        clear_bit(IREQ_PENDING_ABORT, &ireq->flags);
                /* If the request is only waiting on the remote device
                 * suspension, return SUCCESS so the caller will wait too.
                 */
                return SCI_SUCCESS;
        case SCI_REQ_COMPLETED:
        default:
                dev_warn(&ireq->owning_controller->pdev->dev,
                         "%s: SCIC IO Request requested to abort while in wrong "
                         "state %d\n", __func__, ireq->sm.current_state_id);
                break;
        }

        return SCI_FAILURE_INVALID_STATE;
}

enum sci_status sci_request_complete(struct isci_request *ireq)
{
        enum sci_base_request_states state;
        struct isci_host *ihost = ireq->owning_controller;

        state = ireq->sm.current_state_id;
        if (WARN_ONCE(state != SCI_REQ_COMPLETED,
                      "isci: request completion from wrong state (%s)\n",
                      req_state_name(state)))
                return SCI_FAILURE_INVALID_STATE;

        if (ireq->saved_rx_frame_index != SCU_INVALID_FRAME_INDEX)
                sci_controller_release_frame(ihost,
                                                  ireq->saved_rx_frame_index);

        /* XXX can we just stop the machine and remove the 'final' state? */
        sci_change_state(&ireq->sm, SCI_REQ_FINAL);
        return SCI_SUCCESS;
}

enum sci_status sci_io_request_event_handler(struct isci_request *ireq,
                                                  u32 event_code)
{
        enum sci_base_request_states state;
        struct isci_host *ihost = ireq->owning_controller;

        state = ireq->sm.current_state_id;

        if (state != SCI_REQ_STP_PIO_DATA_IN) {
                dev_warn(&ihost->pdev->dev, "%s: (%x) in wrong state %s\n",
                         __func__, event_code, req_state_name(state));

                return SCI_FAILURE_INVALID_STATE;
        }

        switch (scu_get_event_specifier(event_code)) {
        case SCU_TASK_DONE_CRC_ERR << SCU_EVENT_SPECIFIC_CODE_SHIFT:
                /* We are waiting for data and the SCU has R_ERR the data frame.
                 * Go back to waiting for the D2H Register FIS
                 */
                sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_WAIT_FRAME);
                return SCI_SUCCESS;
        default:
                dev_err(&ihost->pdev->dev,
                        "%s: pio request unexpected event %#x\n",
                        __func__, event_code);

                /* TODO Should we fail the PIO request when we get an
                 * unexpected event?
                 */
                return SCI_FAILURE;
        }
}

/*
 * 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.
 */
static void sci_io_request_copy_response(struct isci_request *ireq)
{
        void *resp_buf;
        u32 len;
        struct ssp_response_iu *ssp_response;
        struct isci_tmf *isci_tmf = isci_request_access_tmf(ireq);

        ssp_response = &ireq->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);
}

static enum sci_status
request_started_state_tc_event(struct isci_request *ireq,
                               u32 completion_code)
{
        struct ssp_response_iu *resp_iu;
        u8 datapres;

        /* 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):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                break;
        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 = &ireq->ssp.rsp;
                ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);

                sci_swab32_cpy(&ireq->ssp.rsp,
                               &ireq->ssp.rsp,
                               word_cnt);

                if (resp->status == 0) {
                        ireq->scu_status = SCU_TASK_DONE_GOOD;
                        ireq->sci_status = SCI_SUCCESS_IO_DONE_EARLY;
                } else {
                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                }
                break;
        }
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_CHECK_RESPONSE): {
                ssize_t word_cnt = SSP_RESP_IU_MAX_SIZE / sizeof(u32);

                sci_swab32_cpy(&ireq->ssp.rsp,
                               &ireq->ssp.rsp,
                               word_cnt);

                ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                break;
        }

        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 = &ireq->ssp.rsp;
                datapres = resp_iu->datapres;

                if (datapres == SAS_DATAPRES_RESPONSE_DATA ||
                    datapres == SAS_DATAPRES_SENSE_DATA) {
                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                } else {
                        ireq->scu_status = SCU_TASK_DONE_GOOD;
                        ireq->sci_status = SCI_SUCCESS;
                }
                break;
        /* 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 (ireq->protocol == SAS_PROTOCOL_STP) {
                        ireq->scu_status = SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
                                           SCU_COMPLETION_TL_STATUS_SHIFT;
                        ireq->sci_status = SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
                } else {
                        ireq->scu_status = SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
                                           SCU_COMPLETION_TL_STATUS_SHIFT;
                        ireq->sci_status = 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):
                ireq->scu_status = SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
                                   SCU_COMPLETION_TL_STATUS_SHIFT;
                ireq->sci_status = 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:
                ireq->scu_status = SCU_GET_COMPLETION_TL_STATUS(completion_code) >>
                                   SCU_COMPLETION_TL_STATUS_SHIFT;
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                break;
        }

        /*
         * TODO: This is probably wrong for ACK/NAK timeout conditions
         */

        /* In all cases we will treat this as the completion of the IO req. */
        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
        return SCI_SUCCESS;
}

static enum sci_status
request_aborting_state_tc_event(struct isci_request *ireq,
                                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):
                ireq->scu_status = SCU_TASK_DONE_TASK_ABORT;
                ireq->sci_status = SCI_FAILURE_IO_TERMINATED;
                sci_change_state(&ireq->sm, SCI_REQ_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;
}

static enum sci_status ssp_task_request_await_tc_event(struct isci_request *ireq,
                                                       u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_TASK_WAIT_TC_RESP);
                break;
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_ACK_NAK_TO):
                /* Currently, the decision is to simply allow the task request
                 * to timeout if the task IU wasn't received successfully.
                 * There is a potential for receiving multiple task responses if
                 * we decide to send the task IU again.
                 */
                dev_warn(&ireq->owning_controller->pdev->dev,
                         "%s: TaskRequest:0x%p CompletionCode:%x - "
                         "ACK/NAK timeout\n", __func__, ireq,
                         completion_code);

                sci_change_state(&ireq->sm, SCI_REQ_TASK_WAIT_TC_RESP);
                break;
        default:
                /*
                 * All other completion status cause the IO to be complete.
                 * If a NAK was received, then it is up to the user to retry
                 * the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static enum sci_status
smp_request_await_response_tc_event(struct isci_request *ireq,
                                    u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                /* In the AWAIT RESPONSE state, any TC completion is
                 * unexpected.  but if the TC has success status, we
                 * complete the IO anyway.
                 */
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        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):
                /* These status has been seen in a specific LSI
                 * expander, which sometimes is not able to send smp
                 * response within 2 ms. This causes our hardware break
                 * the connection and set TC completion with one of
                 * these SMP_XXX_XX_ERR status. For these type of error,
                 * we ask ihost user to retry the request.
                 */
                ireq->scu_status = SCU_TASK_DONE_SMP_RESP_TO_ERR;
                ireq->sci_status = SCI_FAILURE_RETRY_REQUIRED;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        default:
                /* All other completion status cause the IO to be complete.  If a NAK
                 * was received, then it is up to the user to retry the request
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static enum sci_status
smp_request_await_tc_event(struct isci_request *ireq,
                           u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        default:
                /* All other completion status cause the IO to be
                 * complete.  If a NAK was received, then it is up to
                 * the user to retry the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static struct scu_sgl_element *pio_sgl_next(struct isci_stp_request *stp_req)
{
        struct scu_sgl_element *sgl;
        struct scu_sgl_element_pair *sgl_pair;
        struct isci_request *ireq = to_ireq(stp_req);
        struct isci_stp_pio_sgl *pio_sgl = &stp_req->sgl;

        sgl_pair = to_sgl_element_pair(ireq, pio_sgl->index);
        if (!sgl_pair)
                sgl = NULL;
        else if (pio_sgl->set == SCU_SGL_ELEMENT_PAIR_A) {
                if (sgl_pair->B.address_lower == 0 &&
                    sgl_pair->B.address_upper == 0) {
                        sgl = NULL;
                } else {
                        pio_sgl->set = SCU_SGL_ELEMENT_PAIR_B;
                        sgl = &sgl_pair->B;
                }
        } else {
                if (sgl_pair->next_pair_lower == 0 &&
                    sgl_pair->next_pair_upper == 0) {
                        sgl = NULL;
                } else {
                        pio_sgl->index++;
                        pio_sgl->set = SCU_SGL_ELEMENT_PAIR_A;
                        sgl_pair = to_sgl_element_pair(ireq, pio_sgl->index);
                        sgl = &sgl_pair->A;
                }
        }

        return sgl;
}

static enum sci_status
stp_request_non_data_await_h2d_tc_event(struct isci_request *ireq,
                                        u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_STP_NON_DATA_WAIT_D2H);
                break;

        default:
                /* All other completion status cause the IO to be
                 * complete.  If a NAK was received, then it is up to
                 * the user to retry the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

#define SCU_MAX_FRAME_BUFFER_SIZE  0x400  /* 1K is the maximum SCU frame data payload */

/* transmit DATA_FIS from (current sgl + offset) for input
 * parameter length. current sgl and offset is alreay stored in the IO request
 */
static enum sci_status sci_stp_request_pio_data_out_trasmit_data_frame(
        struct isci_request *ireq,
        u32 length)
{
        struct isci_stp_request *stp_req = &ireq->stp.req;
        struct scu_task_context *task_context = ireq->tc;
        struct scu_sgl_element_pair *sgl_pair;
        struct scu_sgl_element *current_sgl;

        /* Recycle the TC and reconstruct it for sending out DATA FIS containing
         * for the data from current_sgl+offset for the input length
         */
        sgl_pair = to_sgl_element_pair(ireq, stp_req->sgl.index);
        if (stp_req->sgl.set == SCU_SGL_ELEMENT_PAIR_A)
                current_sgl = &sgl_pair->A;
        else
                current_sgl = &sgl_pair->B;

        /* update the TC */
        task_context->command_iu_upper = current_sgl->address_upper;
        task_context->command_iu_lower = current_sgl->address_lower;
        task_context->transfer_length_bytes = length;
        task_context->type.stp.fis_type = FIS_DATA;

        /* send the new TC out. */
        return sci_controller_continue_io(ireq);
}

static enum sci_status sci_stp_request_pio_data_out_transmit_data(struct isci_request *ireq)
{
        struct isci_stp_request *stp_req = &ireq->stp.req;
        struct scu_sgl_element_pair *sgl_pair;
        enum sci_status status = SCI_SUCCESS;
        struct scu_sgl_element *sgl;
        u32 offset;
        u32 len = 0;

        offset = stp_req->sgl.offset;
        sgl_pair = to_sgl_element_pair(ireq, stp_req->sgl.index);
        if (WARN_ONCE(!sgl_pair, "%s: null sgl element", __func__))
                return SCI_FAILURE;

        if (stp_req->sgl.set == SCU_SGL_ELEMENT_PAIR_A) {
                sgl = &sgl_pair->A;
                len = sgl_pair->A.length - offset;
        } else {
                sgl = &sgl_pair->B;
                len = sgl_pair->B.length - offset;
        }

        if (stp_req->pio_len == 0)
                return SCI_SUCCESS;

        if (stp_req->pio_len >= len) {
                status = sci_stp_request_pio_data_out_trasmit_data_frame(ireq, len);
                if (status != SCI_SUCCESS)
                        return status;
                stp_req->pio_len -= len;

                /* update the current sgl, offset and save for future */
                sgl = pio_sgl_next(stp_req);
                offset = 0;
        } else if (stp_req->pio_len < len) {
                sci_stp_request_pio_data_out_trasmit_data_frame(ireq, stp_req->pio_len);

                /* Sgl offset will be adjusted and saved for future */
                offset += stp_req->pio_len;
                sgl->address_lower += stp_req->pio_len;
                stp_req->pio_len = 0;
        }

        stp_req->sgl.offset = offset;

        return status;
}

/**
 * sci_stp_request_pio_data_in_copy_data_buffer()
 * @stp_req: The request that is used for the SGL processing.
 * @data_buf: The buffer of data to be copied.
 * @len: The length of the data transfer.
 *
 * Copy the data from the buffer for the length specified to the IO request SGL
 * specified data region. enum sci_status
 */
static enum sci_status
sci_stp_request_pio_data_in_copy_data_buffer(struct isci_stp_request *stp_req,
                                             u8 *data_buf, u32 len)
{
        struct isci_request *ireq;
        u8 *src_addr;
        int copy_len;
        struct sas_task *task;
        struct scatterlist *sg;
        void *kaddr;
        int total_len = len;

        ireq = to_ireq(stp_req);
        task = isci_request_access_task(ireq);
        src_addr = data_buf;

        if (task->num_scatter > 0) {
                sg = task->scatter;

                while (total_len > 0) {
                        struct page *page = sg_page(sg);

                        copy_len = min_t(int, total_len, sg_dma_len(sg));
                        kaddr = kmap_atomic(page);
                        memcpy(kaddr + sg->offset, src_addr, copy_len);
                        kunmap_atomic(kaddr);
                        total_len -= copy_len;
                        src_addr += copy_len;
                        sg = sg_next(sg);
                }
        } else {
                BUG_ON(task->total_xfer_len < total_len);
                memcpy(task->scatter, src_addr, total_len);
        }

        return SCI_SUCCESS;
}

/**
 * sci_stp_request_pio_data_in_copy_data()
 * @stp_req: The PIO DATA IN request that is to receive the data.
 * @data_buffer: The buffer to copy from.
 *
 * Copy the data buffer to the io request data region. enum sci_status
 */
static enum sci_status sci_stp_request_pio_data_in_copy_data(
        struct isci_stp_request *stp_req,
        u8 *data_buffer)
{
        enum sci_status status;

        /*
         * If there is less than 1K remaining in the transfer request
         * copy just the data for the transfer */
        if (stp_req->pio_len < SCU_MAX_FRAME_BUFFER_SIZE) {
                status = sci_stp_request_pio_data_in_copy_data_buffer(
                        stp_req, data_buffer, stp_req->pio_len);

                if (status == SCI_SUCCESS)
                        stp_req->pio_len = 0;
        } else {
                /* We are transfering the whole frame so copy */
                status = sci_stp_request_pio_data_in_copy_data_buffer(
                        stp_req, data_buffer, SCU_MAX_FRAME_BUFFER_SIZE);

                if (status == SCI_SUCCESS)
                        stp_req->pio_len -= SCU_MAX_FRAME_BUFFER_SIZE;
        }

        return status;
}

static enum sci_status
stp_request_pio_await_h2d_completion_tc_event(struct isci_request *ireq,
                                              u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_WAIT_FRAME);
                break;

        default:
                /* All other completion status cause the IO to be
                 * complete.  If a NAK was received, then it is up to
                 * the user to retry the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static enum sci_status
pio_data_out_tx_done_tc_event(struct isci_request *ireq,
                              u32 completion_code)
{
        enum sci_status status = SCI_SUCCESS;
        bool all_frames_transferred = false;
        struct isci_stp_request *stp_req = &ireq->stp.req;

        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                /* Transmit data */
                if (stp_req->pio_len != 0) {
                        status = sci_stp_request_pio_data_out_transmit_data(ireq);
                        if (status == SCI_SUCCESS) {
                                if (stp_req->pio_len == 0)
                                        all_frames_transferred = true;
                        }
                } else if (stp_req->pio_len == 0) {
                        /*
                         * this will happen if the all data is written at the
                         * first time after the pio setup fis is received
                         */
                        all_frames_transferred  = true;
                }

                /* all data transferred. */
                if (all_frames_transferred) {
                        /*
                         * Change the state to SCI_REQ_STP_PIO_DATA_IN
                         * and wait for PIO_SETUP fis / or D2H REg fis. */
                        sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_WAIT_FRAME);
                }
                break;

        default:
                /*
                 * All other completion status cause the IO to be complete.
                 * If a NAK was received, then it is up to the user to retry
                 * the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return status;
}

static enum sci_status sci_stp_request_udma_general_frame_handler(struct isci_request *ireq,
                                                                       u32 frame_index)
{
        struct isci_host *ihost = ireq->owning_controller;
        struct dev_to_host_fis *frame_header;
        enum sci_status status;
        u32 *frame_buffer;

        status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                               frame_index,
                                                               (void **)&frame_header);

        if ((status == SCI_SUCCESS) &&
            (frame_header->fis_type == FIS_REGD2H)) {
                sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                              frame_index,
                                                              (void **)&frame_buffer);

                sci_controller_copy_sata_response(&ireq->stp.rsp,
                                                       frame_header,
                                                       frame_buffer);
        }

        sci_controller_release_frame(ihost, frame_index);

        return status;
}

static enum sci_status process_unsolicited_fis(struct isci_request *ireq,
                                               u32 frame_index)
{
        struct isci_host *ihost = ireq->owning_controller;
        enum sci_status status;
        struct dev_to_host_fis *frame_header;
        u32 *frame_buffer;

        status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                          frame_index,
                                                          (void **)&frame_header);

        if (status != SCI_SUCCESS)
                return status;

        if (frame_header->fis_type != FIS_REGD2H) {
                dev_err(&ireq->isci_host->pdev->dev,
                        "%s ERROR: invalid fis type 0x%X\n",
                        __func__, frame_header->fis_type);
                return SCI_FAILURE;
        }

        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                 frame_index,
                                                 (void **)&frame_buffer);

        sci_controller_copy_sata_response(&ireq->stp.rsp,
                                          (u32 *)frame_header,
                                          frame_buffer);

        /* Frame has been decoded return it to the controller */
        sci_controller_release_frame(ihost, frame_index);

        return status;
}

static enum sci_status atapi_d2h_reg_frame_handler(struct isci_request *ireq,
                                                   u32 frame_index)
{
        struct sas_task *task = isci_request_access_task(ireq);
        enum sci_status status;

        status = process_unsolicited_fis(ireq, frame_index);

        if (status == SCI_SUCCESS) {
                if (ireq->stp.rsp.status & ATA_ERR)
                        status = SCI_FAILURE_IO_RESPONSE_VALID;
        } else {
                status = SCI_FAILURE_IO_RESPONSE_VALID;
        }

        if (status != SCI_SUCCESS) {
                ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                ireq->sci_status = status;
        } else {
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
        }

        /* the d2h ufi is the end of non-data commands */
        if (task->data_dir == DMA_NONE)
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);

        return status;
}

static void scu_atapi_reconstruct_raw_frame_task_context(struct isci_request *ireq)
{
        struct ata_device *dev = sas_to_ata_dev(ireq->target_device->domain_dev);
        void *atapi_cdb = ireq->ttype_ptr.io_task_ptr->ata_task.atapi_packet;
        struct scu_task_context *task_context = ireq->tc;

        /* fill in the SCU Task Context for a DATA fis containing CDB in Raw Frame
         * type. The TC for previous Packet fis was already there, we only need to
         * change the H2D fis content.
         */
        memset(&ireq->stp.cmd, 0, sizeof(struct host_to_dev_fis));
        memcpy(((u8 *)&ireq->stp.cmd + sizeof(u32)), atapi_cdb, ATAPI_CDB_LEN);
        memset(&(task_context->type.stp), 0, sizeof(struct stp_task_context));
        task_context->type.stp.fis_type = FIS_DATA;
        task_context->transfer_length_bytes = dev->cdb_len;
}

static void scu_atapi_construct_task_context(struct isci_request *ireq)
{
        struct ata_device *dev = sas_to_ata_dev(ireq->target_device->domain_dev);
        struct sas_task *task = isci_request_access_task(ireq);
        struct scu_task_context *task_context = ireq->tc;
        int cdb_len = dev->cdb_len;

        /* reference: SSTL 1.13.4.2
         * task_type, sata_direction
         */
        if (task->data_dir == DMA_TO_DEVICE) {
                task_context->task_type = SCU_TASK_TYPE_PACKET_DMA_OUT;
                task_context->sata_direction = 0;
        } else {
                /* todo: for NO_DATA command, we need to send out raw frame. */
                task_context->task_type = SCU_TASK_TYPE_PACKET_DMA_IN;
                task_context->sata_direction = 1;
        }

        memset(&task_context->type.stp, 0, sizeof(task_context->type.stp));
        task_context->type.stp.fis_type = FIS_DATA;

        memset(&ireq->stp.cmd, 0, sizeof(ireq->stp.cmd));
        memcpy(&ireq->stp.cmd.lbal, task->ata_task.atapi_packet, cdb_len);
        task_context->ssp_command_iu_length = cdb_len / sizeof(u32);

        /* task phase is set to TX_CMD */
        task_context->task_phase = 0x1;

        /* retry counter */
        task_context->stp_retry_count = 0;

        /* data transfer size. */
        task_context->transfer_length_bytes = task->total_xfer_len;

        /* setup sgl */
        sci_request_build_sgl(ireq);
}

enum sci_status
sci_io_request_frame_handler(struct isci_request *ireq,
                                  u32 frame_index)
{
        struct isci_host *ihost = ireq->owning_controller;
        struct isci_stp_request *stp_req = &ireq->stp.req;
        enum sci_base_request_states state;
        enum sci_status status;
        ssize_t word_cnt;

        state = ireq->sm.current_state_id;
        switch (state)  {
        case SCI_REQ_STARTED: {
                struct ssp_frame_hdr ssp_hdr;
                void *frame_header;

                sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                              frame_index,
                                                              &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);

                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                      frame_index,
                                                                      (void **)&resp_iu);

                        sci_swab32_cpy(&ireq->ssp.rsp, resp_iu, word_cnt);

                        resp_iu = &ireq->ssp.rsp;

                        if (resp_iu->datapres == SAS_DATAPRES_RESPONSE_DATA ||
                            resp_iu->datapres == SAS_DATAPRES_SENSE_DATA) {
                                ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                        } else {
                                ireq->scu_status = SCU_TASK_DONE_GOOD;
                                ireq->sci_status = SCI_SUCCESS;
                        }
                } else {
                        /* not a response frame, why did it get forwarded? */
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC IO Request 0x%p received unexpected "
                                "frame %d type 0x%02x\n", __func__, ireq,
                                frame_index, ssp_hdr.frame_type);
                }

                /*
                 * In any case we are done with this frame buffer return it to
                 * the controller
                 */
                sci_controller_release_frame(ihost, frame_index);

                return SCI_SUCCESS;
        }

        case SCI_REQ_TASK_WAIT_TC_RESP:
                sci_io_request_copy_response(ireq);
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                sci_controller_release_frame(ihost, frame_index);
                return SCI_SUCCESS;

        case SCI_REQ_SMP_WAIT_RESP: {
                struct sas_task *task = isci_request_access_task(ireq);
                struct scatterlist *sg = &task->smp_task.smp_resp;
                void *frame_header, *kaddr;
                u8 *rsp;

                sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                         frame_index,
                                                         &frame_header);
                kaddr = kmap_atomic(sg_page(sg));
                rsp = kaddr + sg->offset;
                sci_swab32_cpy(rsp, frame_header, 1);

                if (rsp[0] == SMP_RESPONSE) {
                        void *smp_resp;

                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                 frame_index,
                                                                 &smp_resp);

                        word_cnt = (sg->length/4)-1;
                        if (word_cnt > 0)
                                word_cnt = min_t(unsigned int, word_cnt,
                                                 SCU_UNSOLICITED_FRAME_BUFFER_SIZE/4);
                        sci_swab32_cpy(rsp + 4, smp_resp, word_cnt);

                        ireq->scu_status = SCU_TASK_DONE_GOOD;
                        ireq->sci_status = SCI_SUCCESS;
                        sci_change_state(&ireq->sm, SCI_REQ_SMP_WAIT_TC_COMP);
                } else {
                        /*
                         * This was not a response frame why did it get
                         * forwarded?
                         */
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC SMP Request 0x%p received unexpected "
                                "frame %d type 0x%02x\n",
                                __func__,
                                ireq,
                                frame_index,
                                rsp[0]);

                        ireq->scu_status = SCU_TASK_DONE_SMP_FRM_TYPE_ERR;
                        ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                }
                kunmap_atomic(kaddr);

                sci_controller_release_frame(ihost, frame_index);

                return SCI_SUCCESS;
        }

        case SCI_REQ_STP_UDMA_WAIT_TC_COMP:
                return sci_stp_request_udma_general_frame_handler(ireq,
                                                                       frame_index);

        case SCI_REQ_STP_UDMA_WAIT_D2H:
                /* Use the general frame handler to copy the resposne data */
                status = sci_stp_request_udma_general_frame_handler(ireq, frame_index);

                if (status != SCI_SUCCESS)
                        return status;

                ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                return SCI_SUCCESS;

        case SCI_REQ_STP_NON_DATA_WAIT_D2H: {
                struct dev_to_host_fis *frame_header;
                u32 *frame_buffer;

                status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                                       frame_index,
                                                                       (void **)&frame_header);

                if (status != SCI_SUCCESS) {
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC IO Request 0x%p could not get frame "
                                "header for frame index %d, status %x\n",
                                __func__,
                                stp_req,
                                frame_index,
                                status);

                        return status;
                }

                switch (frame_header->fis_type) {
                case FIS_REGD2H:
                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                      frame_index,
                                                                      (void **)&frame_buffer);

                        sci_controller_copy_sata_response(&ireq->stp.rsp,
                                                               frame_header,
                                                               frame_buffer);

                        /* The command has completed with error */
                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                        break;

                default:
                        dev_warn(&ihost->pdev->dev,
                                 "%s: IO Request:0x%p Frame Id:%d protocol "
                                  "violation occurred\n", __func__, stp_req,
                                  frame_index);

                        ireq->scu_status = SCU_TASK_DONE_UNEXP_FIS;
                        ireq->sci_status = SCI_FAILURE_PROTOCOL_VIOLATION;
                        break;
                }

                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);

                /* Frame has been decoded return it to the controller */
                sci_controller_release_frame(ihost, frame_index);

                return status;
        }

        case SCI_REQ_STP_PIO_WAIT_FRAME: {
                struct sas_task *task = isci_request_access_task(ireq);
                struct dev_to_host_fis *frame_header;
                u32 *frame_buffer;

                status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                                       frame_index,
                                                                       (void **)&frame_header);

                if (status != SCI_SUCCESS) {
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC IO Request 0x%p could not get frame "
                                "header for frame index %d, status %x\n",
                                __func__, stp_req, frame_index, status);
                        return status;
                }

                switch (frame_header->fis_type) {
                case FIS_PIO_SETUP:
                        /* Get from the frame buffer the PIO Setup Data */
                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                      frame_index,
                                                                      (void **)&frame_buffer);

                        /* Get the data from the PIO Setup The SCU Hardware
                         * returns first word in the frame_header and the rest
                         * of the data is in the frame buffer so we need to
                         * back up one dword
                         */

                        /* transfer_count: first 16bits in the 4th dword */
                        stp_req->pio_len = frame_buffer[3] & 0xffff;

                        /* status: 4th byte in the 3rd dword */
                        stp_req->status = (frame_buffer[2] >> 24) & 0xff;

                        sci_controller_copy_sata_response(&ireq->stp.rsp,
                                                               frame_header,
                                                               frame_buffer);

                        ireq->stp.rsp.status = stp_req->status;

                        /* The next state is dependent on whether the
                         * request was PIO Data-in or Data out
                         */
                        if (task->data_dir == DMA_FROM_DEVICE) {
                                sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_DATA_IN);
                        } else if (task->data_dir == DMA_TO_DEVICE) {
                                /* Transmit data */
                                status = sci_stp_request_pio_data_out_transmit_data(ireq);
                                if (status != SCI_SUCCESS)
                                        break;
                                sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_DATA_OUT);
                        }
                        break;

                case FIS_SETDEVBITS:
                        sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_WAIT_FRAME);
                        break;

                case FIS_REGD2H:
                        if (frame_header->status & ATA_BUSY) {
                                /*
                                 * Now why is the drive sending a D2H Register
                                 * FIS when it is still busy?  Do nothing since
                                 * we are still in the right state.
                                 */
                                dev_dbg(&ihost->pdev->dev,
                                        "%s: SCIC PIO Request 0x%p received "
                                        "D2H Register FIS with BSY status "
                                        "0x%x\n",
                                        __func__,
                                        stp_req,
                                        frame_header->status);
                                break;
                        }

                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                      frame_index,
                                                                      (void **)&frame_buffer);

                        sci_controller_copy_sata_response(&ireq->stp.rsp,
                                                               frame_header,
                                                               frame_buffer);

                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                        break;

                default:
                        /* FIXME: what do we do here? */
                        break;
                }

                /* Frame is decoded return it to the controller */
                sci_controller_release_frame(ihost, frame_index);

                return status;
        }

        case SCI_REQ_STP_PIO_DATA_IN: {
                struct dev_to_host_fis *frame_header;
                struct sata_fis_data *frame_buffer;

                status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
                                                                       frame_index,
                                                                       (void **)&frame_header);

                if (status != SCI_SUCCESS) {
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC IO Request 0x%p could not get frame "
                                "header for frame index %d, status %x\n",
                                __func__,
                                stp_req,
                                frame_index,
                                status);
                        return status;
                }

                if (frame_header->fis_type != FIS_DATA) {
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC PIO Request 0x%p received frame %d "
                                "with fis type 0x%02x when expecting a data "
                                "fis.\n",
                                __func__,
                                stp_req,
                                frame_index,
                                frame_header->fis_type);

                        ireq->scu_status = SCU_TASK_DONE_GOOD;
                        ireq->sci_status = SCI_FAILURE_IO_REQUIRES_SCSI_ABORT;
                        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);

                        /* Frame is decoded return it to the controller */
                        sci_controller_release_frame(ihost, frame_index);
                        return status;
                }

                if (stp_req->sgl.index < 0) {
                        ireq->saved_rx_frame_index = frame_index;
                        stp_req->pio_len = 0;
                } else {
                        sci_unsolicited_frame_control_get_buffer(&ihost->uf_control,
                                                                      frame_index,
                                                                      (void **)&frame_buffer);

                        status = sci_stp_request_pio_data_in_copy_data(stp_req,
                                                                            (u8 *)frame_buffer);

                        /* Frame is decoded return it to the controller */
                        sci_controller_release_frame(ihost, frame_index);
                }

                /* Check for the end of the transfer, are there more
                 * bytes remaining for this data transfer
                 */
                if (status != SCI_SUCCESS || stp_req->pio_len != 0)
                        return status;

                if ((stp_req->status & ATA_BUSY) == 0) {
                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                } else {
                        sci_change_state(&ireq->sm, SCI_REQ_STP_PIO_WAIT_FRAME);
                }
                return status;
        }

        case SCI_REQ_ATAPI_WAIT_PIO_SETUP: {
                struct sas_task *task = isci_request_access_task(ireq);

                sci_controller_release_frame(ihost, frame_index);
                ireq->target_device->working_request = ireq;
                if (task->data_dir == DMA_NONE) {
                        sci_change_state(&ireq->sm, SCI_REQ_ATAPI_WAIT_TC_COMP);
                        scu_atapi_reconstruct_raw_frame_task_context(ireq);
                } else {
                        sci_change_state(&ireq->sm, SCI_REQ_ATAPI_WAIT_D2H);
                        scu_atapi_construct_task_context(ireq);
                }

                sci_controller_continue_io(ireq);
                return SCI_SUCCESS;
        }
        case SCI_REQ_ATAPI_WAIT_D2H:
                return atapi_d2h_reg_frame_handler(ireq, frame_index);
        case SCI_REQ_ABORTING:
                /*
                 * TODO: Is it even possible to get an unsolicited frame in the
                 * aborting state?
                 */
                sci_controller_release_frame(ihost, frame_index);
                return SCI_SUCCESS;

        default:
                dev_warn(&ihost->pdev->dev,
                         "%s: SCIC IO Request given unexpected frame %x while "
                         "in state %d\n",
                         __func__,
                         frame_index,
                         state);

                sci_controller_release_frame(ihost, frame_index);
                return SCI_FAILURE_INVALID_STATE;
        }
}

static enum sci_status stp_request_udma_await_tc_event(struct isci_request *ireq,
                                                       u32 completion_code)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_UNEXP_FIS):
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_REG_ERR):
                /* We must check ther response buffer to see if the D2H
                 * Register FIS was received before we got the TC
                 * completion.
                 */
                if (ireq->stp.rsp.fis_type == FIS_REGD2H) {
                        sci_remote_device_suspend(ireq->target_device,
                                                  SCI_SW_SUSPEND_NORMAL);

                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;
                        sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                } else {
                        /* If we have an error completion status for the
                         * TC then we can expect a D2H register FIS from
                         * the device so we must change state to wait
                         * for it
                         */
                        sci_change_state(&ireq->sm, SCI_REQ_STP_UDMA_WAIT_D2H);
                }
                break;

        /* TODO Check to see if any of these completion status need to
         * wait for the device to host register fis.
         */
        /* TODO We can retry the command for SCU_TASK_DONE_CMD_LL_R_ERR
         * - this comes only for B0
         */
        default:
                /* All other completion status cause the IO to be complete. */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static enum sci_status atapi_raw_completion(struct isci_request *ireq, u32 completion_code,
                                                  enum sci_base_request_states next)
{
        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, next);
                break;
        default:
                /* All other completion status cause the IO to be complete.
                 * If a NAK was received, then it is up to the user to retry
                 * the request.
                 */
                ireq->scu_status = SCU_NORMALIZE_COMPLETION_STATUS(completion_code);
                ireq->sci_status = SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR;

                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;
        }

        return SCI_SUCCESS;
}

static enum sci_status atapi_data_tc_completion_handler(struct isci_request *ireq,
                                                        u32 completion_code)
{
        struct isci_remote_device *idev = ireq->target_device;
        struct dev_to_host_fis *d2h = &ireq->stp.rsp;
        enum sci_status status = SCI_SUCCESS;

        switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
        case (SCU_TASK_DONE_GOOD << SCU_COMPLETION_TL_STATUS_SHIFT):
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;

        case (SCU_TASK_DONE_UNEXP_FIS << SCU_COMPLETION_TL_STATUS_SHIFT): {
                u16 len = sci_req_tx_bytes(ireq);

                /* likely non-error data underrun, workaround missing
                 * d2h frame from the controller
                 */
                if (d2h->fis_type != FIS_REGD2H) {
                        d2h->fis_type = FIS_REGD2H;
                        d2h->flags = (1 << 6);
                        d2h->status = 0x50;
                        d2h->error = 0;
                        d2h->lbal = 0;
                        d2h->byte_count_low = len & 0xff;
                        d2h->byte_count_high = len >> 8;
                        d2h->device = 0xa0;
                        d2h->lbal_exp = 0;
                        d2h->lbam_exp = 0;
                        d2h->lbah_exp = 0;
                        d2h->_r_a = 0;
                        d2h->sector_count = 0x3;
                        d2h->sector_count_exp = 0;
                        d2h->_r_b = 0;
                        d2h->_r_c = 0;
                        d2h->_r_d = 0;
                }

                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS_IO_DONE_EARLY;
                status = ireq->sci_status;

                /* the hw will have suspended the rnc, so complete the
                 * request upon pending resume
                 */
                sci_change_state(&idev->sm, SCI_STP_DEV_ATAPI_ERROR);
                break;
        }
        case (SCU_TASK_DONE_EXCESS_DATA << SCU_COMPLETION_TL_STATUS_SHIFT):
                /* In this case, there is no UF coming after.
                 * compelte the IO now.
                 */
                ireq->scu_status = SCU_TASK_DONE_GOOD;
                ireq->sci_status = SCI_SUCCESS;
                sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
                break;

        default:
                if (d2h->fis_type == FIS_REGD2H) {
                        /* UF received change the device state to ATAPI_ERROR */
                        status = ireq->sci_status;
                        sci_change_state(&idev->sm, SCI_STP_DEV_ATAPI_ERROR);
                } else {
                        /* If receiving any non-success TC status, no UF
                         * received yet, then an UF for the status fis
                         * is coming after (XXX: suspect this is
                         * actually a protocol error or a bug like the
                         * DONE_UNEXP_FIS case)
                         */
                        ireq->scu_status = SCU_TASK_DONE_CHECK_RESPONSE;
                        ireq->sci_status = SCI_FAILURE_IO_RESPONSE_VALID;

                        sci_change_state(&ireq->sm, SCI_REQ_ATAPI_WAIT_D2H);
                }
                break;
        }

        return status;
}

static int sci_request_smp_completion_status_is_tx_suspend(
        unsigned int completion_status)
{
        switch (completion_status) {
        case SCU_TASK_OPEN_REJECT_WRONG_DESTINATION:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3:
        case SCU_TASK_OPEN_REJECT_BAD_DESTINATION:
        case SCU_TASK_OPEN_REJECT_ZONE_VIOLATION:
                return 1;
        }
        return 0;
}

static int sci_request_smp_completion_status_is_tx_rx_suspend(
        unsigned int completion_status)
{
        return 0; /* There are no Tx/Rx SMP suspend conditions. */
}

static int sci_request_ssp_completion_status_is_tx_suspend(
        unsigned int completion_status)
{
        switch (completion_status) {
        case SCU_TASK_DONE_TX_RAW_CMD_ERR:
        case SCU_TASK_DONE_LF_ERR:
        case SCU_TASK_OPEN_REJECT_WRONG_DESTINATION:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3:
        case SCU_TASK_OPEN_REJECT_BAD_DESTINATION:
        case SCU_TASK_OPEN_REJECT_ZONE_VIOLATION:
        case SCU_TASK_OPEN_REJECT_STP_RESOURCES_BUSY:
        case SCU_TASK_OPEN_REJECT_PROTOCOL_NOT_SUPPORTED:
        case SCU_TASK_OPEN_REJECT_CONNECTION_RATE_NOT_SUPPORTED:
                return 1;
        }
        return 0;
}

static int sci_request_ssp_completion_status_is_tx_rx_suspend(
        unsigned int completion_status)
{
        return 0; /* There are no Tx/Rx SSP suspend conditions. */
}

static int sci_request_stpsata_completion_status_is_tx_suspend(
        unsigned int completion_status)
{
        switch (completion_status) {
        case SCU_TASK_DONE_TX_RAW_CMD_ERR:
        case SCU_TASK_DONE_LL_R_ERR:
        case SCU_TASK_DONE_LL_PERR:
        case SCU_TASK_DONE_REG_ERR:
        case SCU_TASK_DONE_SDB_ERR:
        case SCU_TASK_OPEN_REJECT_WRONG_DESTINATION:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2:
        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3:
        case SCU_TASK_OPEN_REJECT_BAD_DESTINATION:
        case SCU_TASK_OPEN_REJECT_ZONE_VIOLATION:
        case SCU_TASK_OPEN_REJECT_STP_RESOURCES_BUSY:
        case SCU_TASK_OPEN_REJECT_PROTOCOL_NOT_SUPPORTED:
        case SCU_TASK_OPEN_REJECT_CONNECTION_RATE_NOT_SUPPORTED:
                return 1;
        }
        return 0;
}


static int sci_request_stpsata_completion_status_is_tx_rx_suspend(
        unsigned int completion_status)
{
        switch (completion_status) {
        case SCU_TASK_DONE_LF_ERR:
        case SCU_TASK_DONE_LL_SY_TERM:
        case SCU_TASK_DONE_LL_LF_TERM:
        case SCU_TASK_DONE_BREAK_RCVD:
        case SCU_TASK_DONE_INV_FIS_LEN:
        case SCU_TASK_DONE_UNEXP_FIS:
        case SCU_TASK_DONE_UNEXP_SDBFIS:
        case SCU_TASK_DONE_MAX_PLD_ERR:
                return 1;
        }
        return 0;
}

static void sci_request_handle_suspending_completions(
        struct isci_request *ireq,
        u32 completion_code)
{
        int is_tx = 0;
        int is_tx_rx = 0;

        switch (ireq->protocol) {
        case SAS_PROTOCOL_SMP:
                is_tx = sci_request_smp_completion_status_is_tx_suspend(
                        completion_code);
                is_tx_rx = sci_request_smp_completion_status_is_tx_rx_suspend(
                        completion_code);
                break;
        case SAS_PROTOCOL_SSP:
                is_tx = sci_request_ssp_completion_status_is_tx_suspend(
                        completion_code);
                is_tx_rx = sci_request_ssp_completion_status_is_tx_rx_suspend(
                        completion_code);
                break;
        case SAS_PROTOCOL_STP:
                is_tx = sci_request_stpsata_completion_status_is_tx_suspend(
                        completion_code);
                is_tx_rx =
                        sci_request_stpsata_completion_status_is_tx_rx_suspend(
                                completion_code);
                break;
        default:
                dev_warn(&ireq->isci_host->pdev->dev,
                         "%s: request %p has no valid protocol\n",
                         __func__, ireq);
                break;
        }
        if (is_tx || is_tx_rx) {
                BUG_ON(is_tx && is_tx_rx);

                sci_remote_node_context_suspend(
                        &ireq->target_device->rnc,
                        SCI_HW_SUSPEND,
                        (is_tx_rx) ? SCU_EVENT_TL_RNC_SUSPEND_TX_RX
                                   : SCU_EVENT_TL_RNC_SUSPEND_TX);
        }
}

enum sci_status
sci_io_request_tc_completion(struct isci_request *ireq,
                             u32 completion_code)
{
        enum sci_base_request_states state;
        struct isci_host *ihost = ireq->owning_controller;

        state = ireq->sm.current_state_id;

        /* Decode those completions that signal upcoming suspension events. */
        sci_request_handle_suspending_completions(
                ireq, SCU_GET_COMPLETION_TL_STATUS(completion_code));

        switch (state) {
        case SCI_REQ_STARTED:
                return request_started_state_tc_event(ireq, completion_code);

        case SCI_REQ_TASK_WAIT_TC_COMP:
                return ssp_task_request_await_tc_event(ireq,
                                                       completion_code);

        case SCI_REQ_SMP_WAIT_RESP:
                return smp_request_await_response_tc_event(ireq,
                                                           completion_code);

        case SCI_REQ_SMP_WAIT_TC_COMP:
                return smp_request_await_tc_event(ireq, completion_code);

        case SCI_REQ_STP_UDMA_WAIT_TC_COMP:
                return stp_request_udma_await_tc_event(ireq,
                                                       completion_code);

        case SCI_REQ_STP_NON_DATA_WAIT_H2D:
                return stp_request_non_data_await_h2d_tc_event(ireq,
                                                               completion_code);

        case SCI_REQ_STP_PIO_WAIT_H2D:
                return stp_request_pio_await_h2d_completion_tc_event(ireq,
                                                                     completion_code);

        case SCI_REQ_STP_PIO_DATA_OUT:
                return pio_data_out_tx_done_tc_event(ireq, completion_code);

        case SCI_REQ_ABORTING:
                return request_aborting_state_tc_event(ireq,
                                                       completion_code);

        case SCI_REQ_ATAPI_WAIT_H2D:
                return atapi_raw_completion(ireq, completion_code,
                                            SCI_REQ_ATAPI_WAIT_PIO_SETUP);

        case SCI_REQ_ATAPI_WAIT_TC_COMP:
                return atapi_raw_completion(ireq, completion_code,
                                            SCI_REQ_ATAPI_WAIT_D2H);

        case SCI_REQ_ATAPI_WAIT_D2H:
                return atapi_data_tc_completion_handler(ireq, completion_code);

        default:
                dev_warn(&ihost->pdev->dev, "%s: %x in wrong state %s\n",
                         __func__, completion_code, req_state_name(state));
                return SCI_FAILURE_INVALID_STATE;
        }
}

/**
 * isci_request_process_response_iu() - This function sets the status and
 *    response iu, in the task struct, from the request object for the upper
 *    layer driver.
 * @task: This parameter is the task struct from the upper layer driver.
 * @resp_iu: This parameter points to the response iu of the completed request.
 * @dev: This parameter specifies the linux device struct.
 *
 * none.
 */
static void isci_request_process_response_iu(
        struct sas_task *task,
        struct ssp_response_iu *resp_iu,
        struct device *dev)
{
        dev_dbg(dev,
                "%s: resp_iu = %p "
                "resp_iu->status = 0x%x,\nresp_iu->datapres = %d "
                "resp_iu->response_data_len = %x, "
                "resp_iu->sense_data_len = %x\nresponse data: ",
                __func__,
                resp_iu,
                resp_iu->status,
                resp_iu->datapres,
                resp_iu->response_data_len,
                resp_iu->sense_data_len);

        task->task_status.stat = resp_iu->status;

        /* libsas updates the task status fields based on the response iu. */
        sas_ssp_task_response(dev, task, resp_iu);
}

/**
 * isci_request_set_open_reject_status() - This function prepares the I/O
 *    completion for OPEN_REJECT conditions.
 * @request: This parameter is the completed isci_request object.
 * @task: This parameter is the task struct from the upper layer driver.
 * @response_ptr: This parameter specifies the service response for the I/O.
 * @status_ptr: This parameter specifies the exec status for the I/O.
 * @open_rej_reason: This parameter specifies the encoded reason for the
 *    abandon-class reject.
 *
 * none.
 */
static void isci_request_set_open_reject_status(
        struct isci_request *request,
        struct sas_task *task,
        enum service_response *response_ptr,
        enum exec_status *status_ptr,
        enum sas_open_rej_reason open_rej_reason)
{
        /* Task in the target is done. */
        set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
        *response_ptr                     = SAS_TASK_UNDELIVERED;
        *status_ptr                       = SAS_OPEN_REJECT;
        task->task_status.open_rej_reason = open_rej_reason;
}

/**
 * isci_request_handle_controller_specific_errors() - This function decodes
 *    controller-specific I/O completion error conditions.
 * @idev: Remote device
 * @request: This parameter is the completed isci_request object.
 * @task: This parameter is the task struct from the upper layer driver.
 * @response_ptr: This parameter specifies the service response for the I/O.
 * @status_ptr: This parameter specifies the exec status for the I/O.
 *
 * none.
 */
static void isci_request_handle_controller_specific_errors(
        struct isci_remote_device *idev,
        struct isci_request *request,
        struct sas_task *task,
        enum service_response *response_ptr,
        enum exec_status *status_ptr)
{
        unsigned int cstatus;

        cstatus = request->scu_status;

        dev_dbg(&request->isci_host->pdev->dev,
                "%s: %p SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR "
                "- controller status = 0x%x\n",
                __func__, request, cstatus);

        /* Decode the controller-specific errors; most
         * important is to recognize those conditions in which
         * the target may still have a task outstanding that
         * must be aborted.
         *
         * Note that there are SCU completion codes being
         * named in the decode below for which SCIC has already
         * done work to handle them in a way other than as
         * a controller-specific completion code; these are left
         * in the decode below for completeness sake.
         */
        switch (cstatus) {
        case SCU_TASK_DONE_DMASETUP_DIRERR:
        /* Also SCU_TASK_DONE_SMP_FRM_TYPE_ERR: */
        case SCU_TASK_DONE_XFERCNT_ERR:
                /* Also SCU_TASK_DONE_SMP_UFI_ERR: */
                if (task->task_proto == SAS_PROTOCOL_SMP) {
                        /* SCU_TASK_DONE_SMP_UFI_ERR == Task Done. */
                        *response_ptr = SAS_TASK_COMPLETE;

                        /* See if the device has been/is being stopped. Note
                         * that we ignore the quiesce state, since we are
                         * concerned about the actual device state.
                         */
                        if (!idev)
                                *status_ptr = SAS_DEVICE_UNKNOWN;
                        else
                                *status_ptr = SAS_ABORTED_TASK;

                        set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                } else {
                        /* Task in the target is not done. */
                        *response_ptr = SAS_TASK_UNDELIVERED;

                        if (!idev)
                                *status_ptr = SAS_DEVICE_UNKNOWN;
                        else
                                *status_ptr = SAS_SAM_STAT_TASK_ABORTED;

                        clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                }

                break;

        case SCU_TASK_DONE_CRC_ERR:
        case SCU_TASK_DONE_NAK_CMD_ERR:
        case SCU_TASK_DONE_EXCESS_DATA:
        case SCU_TASK_DONE_UNEXP_FIS:
        /* Also SCU_TASK_DONE_UNEXP_RESP: */
        case SCU_TASK_DONE_VIIT_ENTRY_NV:       /* TODO - conditions? */
        case SCU_TASK_DONE_IIT_ENTRY_NV:        /* TODO - conditions? */
        case SCU_TASK_DONE_RNCNV_OUTBOUND:      /* TODO - conditions? */
                /* These are conditions in which the target
                 * has completed the task, so that no cleanup
                 * is necessary.
                 */
                *response_ptr = SAS_TASK_COMPLETE;

                /* See if the device has been/is being stopped. Note
                 * that we ignore the quiesce state, since we are
                 * concerned about the actual device state.
                 */
                if (!idev)
                        *status_ptr = SAS_DEVICE_UNKNOWN;
                else
                        *status_ptr = SAS_ABORTED_TASK;

                set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                break;


        /* Note that the only open reject completion codes seen here will be
         * abandon-class codes; all others are automatically retried in the SCU.
         */
        case SCU_TASK_OPEN_REJECT_WRONG_DESTINATION:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_WRONG_DEST);
                break;

        case SCU_TASK_OPEN_REJECT_ZONE_VIOLATION:

                /* Note - the return of AB0 will change when
                 * libsas implements detection of zone violations.
                 */
                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_RESV_AB0);
                break;

        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_RESV_AB1);
                break;

        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_RESV_AB2);
                break;

        case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_RESV_AB3);
                break;

        case SCU_TASK_OPEN_REJECT_BAD_DESTINATION:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_BAD_DEST);
                break;

        case SCU_TASK_OPEN_REJECT_STP_RESOURCES_BUSY:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_STP_NORES);
                break;

        case SCU_TASK_OPEN_REJECT_PROTOCOL_NOT_SUPPORTED:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_EPROTO);
                break;

        case SCU_TASK_OPEN_REJECT_CONNECTION_RATE_NOT_SUPPORTED:

                isci_request_set_open_reject_status(
                        request, task, response_ptr, status_ptr,
                        SAS_OREJ_CONN_RATE);
                break;

        case SCU_TASK_DONE_LL_R_ERR:
        /* Also SCU_TASK_DONE_ACK_NAK_TO: */
        case SCU_TASK_DONE_LL_PERR:
        case SCU_TASK_DONE_LL_SY_TERM:
        /* Also SCU_TASK_DONE_NAK_ERR:*/
        case SCU_TASK_DONE_LL_LF_TERM:
        /* Also SCU_TASK_DONE_DATA_LEN_ERR: */
        case SCU_TASK_DONE_LL_ABORT_ERR:
        case SCU_TASK_DONE_SEQ_INV_TYPE:
        /* Also SCU_TASK_DONE_UNEXP_XR: */
        case SCU_TASK_DONE_XR_IU_LEN_ERR:
        case SCU_TASK_DONE_INV_FIS_LEN:
        /* Also SCU_TASK_DONE_XR_WD_LEN: */
        case SCU_TASK_DONE_SDMA_ERR:
        case SCU_TASK_DONE_OFFSET_ERR:
        case SCU_TASK_DONE_MAX_PLD_ERR:
        case SCU_TASK_DONE_LF_ERR:
        case SCU_TASK_DONE_SMP_RESP_TO_ERR:  /* Escalate to dev reset? */
        case SCU_TASK_DONE_SMP_LL_RX_ERR:
        case SCU_TASK_DONE_UNEXP_DATA:
        case SCU_TASK_DONE_UNEXP_SDBFIS:
        case SCU_TASK_DONE_REG_ERR:
        case SCU_TASK_DONE_SDB_ERR:
        case SCU_TASK_DONE_TASK_ABORT:
        default:
                /* Task in the target is not done. */
                *response_ptr = SAS_TASK_UNDELIVERED;
                *status_ptr = SAS_SAM_STAT_TASK_ABORTED;

                if (task->task_proto == SAS_PROTOCOL_SMP)
                        set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                else
                        clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                break;
        }
}

static void isci_process_stp_response(struct sas_task *task, struct dev_to_host_fis *fis)
{
        struct task_status_struct *ts = &task->task_status;
        struct ata_task_resp *resp = (void *)&ts->buf[0];

        resp->frame_len = sizeof(*fis);
        memcpy(resp->ending_fis, fis, sizeof(*fis));
        ts->buf_valid_size = sizeof(*resp);

        /* If an error is flagged let libata decode the fis */
        if (ac_err_mask(fis->status))
                ts->stat = SAS_PROTO_RESPONSE;
        else
                ts->stat = SAS_SAM_STAT_GOOD;

        ts->resp = SAS_TASK_COMPLETE;
}

static void isci_request_io_request_complete(struct isci_host *ihost,
                                             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;
        unsigned long task_flags;
        struct isci_remote_device *idev = request->target_device;
        enum service_response response = SAS_TASK_UNDELIVERED;
        enum exec_status status = SAS_ABORTED_TASK;

        dev_dbg(&ihost->pdev->dev,
                "%s: request = %p, task = %p, "
                "task->data_dir = %d completion_status = 0x%x\n",
                __func__, request, task, task->data_dir, completion_status);

        /* The request is done from an SCU HW perspective. */

        /* This is an active request being completed from the core. */
        switch (completion_status) {

        case SCI_IO_FAILURE_RESPONSE_VALID:
                dev_dbg(&ihost->pdev->dev,
                        "%s: SCI_IO_FAILURE_RESPONSE_VALID (%p/%p)\n",
                        __func__, request, task);

                if (sas_protocol_ata(task->task_proto)) {
                        isci_process_stp_response(task, &request->stp.rsp);
                } else if (SAS_PROTOCOL_SSP == task->task_proto) {

                        /* crack the iu response buffer. */
                        resp_iu = &request->ssp.rsp;
                        isci_request_process_response_iu(task, resp_iu,
                                                         &ihost->pdev->dev);

                } else if (SAS_PROTOCOL_SMP == task->task_proto) {

                        dev_err(&ihost->pdev->dev,
                                "%s: SCI_IO_FAILURE_RESPONSE_VALID: "
                                        "SAS_PROTOCOL_SMP protocol\n",
                                __func__);

                } else
                        dev_err(&ihost->pdev->dev,
                                "%s: unknown protocol\n", __func__);

                /* use the task status set in the task struct by the
                * isci_request_process_response_iu call.
                */
                set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                response = task->task_status.resp;
                status = task->task_status.stat;
                break;

        case SCI_IO_SUCCESS:
        case SCI_IO_SUCCESS_IO_DONE_EARLY:

                response = SAS_TASK_COMPLETE;
                status   = SAS_SAM_STAT_GOOD;
                set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);

                if (completion_status == SCI_IO_SUCCESS_IO_DONE_EARLY) {

                        /* This was an SSP / STP / SATA transfer.
                        * There is a possibility that less data than
                        * the maximum was transferred.
                        */
                        u32 transferred_length = sci_req_tx_bytes(request);

                        task->task_status.residual
                                = task->total_xfer_len - transferred_length;

                        /* If there were residual bytes, call this an
                        * underrun.
                        */
                        if (task->task_status.residual != 0)
                                status = SAS_DATA_UNDERRUN;

                        dev_dbg(&ihost->pdev->dev,
                                "%s: SCI_IO_SUCCESS_IO_DONE_EARLY %d\n",
                                __func__, status);

                } else
                        dev_dbg(&ihost->pdev->dev, "%s: SCI_IO_SUCCESS\n",
                                __func__);
                break;

        case SCI_IO_FAILURE_TERMINATED:

                dev_dbg(&ihost->pdev->dev,
                        "%s: SCI_IO_FAILURE_TERMINATED (%p/%p)\n",
                        __func__, request, task);

                /* The request was terminated explicitly. */
                set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                response = SAS_TASK_UNDELIVERED;

                /* See if the device has been/is being stopped. Note
                * that we ignore the quiesce state, since we are
                * concerned about the actual device state.
                */
                if (!idev)
                        status = SAS_DEVICE_UNKNOWN;
                else
                        status = SAS_ABORTED_TASK;
                break;

        case SCI_FAILURE_CONTROLLER_SPECIFIC_IO_ERR:

                isci_request_handle_controller_specific_errors(idev, request,
                                                               task, &response,
                                                               &status);
                break;

        case SCI_IO_FAILURE_REMOTE_DEVICE_RESET_REQUIRED:
                /* This is a special case, in that the I/O completion
                * is telling us that the device needs a reset.
                * In order for the device reset condition to be
                * noticed, the I/O has to be handled in the error
                * handler.  Set the reset flag and cause the
                * SCSI error thread to be scheduled.
                */
                spin_lock_irqsave(&task->task_state_lock, task_flags);
                task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
                spin_unlock_irqrestore(&task->task_state_lock, task_flags);

                /* Fail the I/O. */
                response = SAS_TASK_UNDELIVERED;
                status = SAS_SAM_STAT_TASK_ABORTED;

                clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                break;

        case SCI_FAILURE_RETRY_REQUIRED:

                /* Fail the I/O so it can be retried. */
                response = SAS_TASK_UNDELIVERED;
                if (!idev)
                        status = SAS_DEVICE_UNKNOWN;
                else
                        status = SAS_ABORTED_TASK;

                set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                break;


        default:
                /* Catch any otherwise unhandled error codes here. */
                dev_dbg(&ihost->pdev->dev,
                        "%s: invalid completion code: 0x%x - "
                                "isci_request = %p\n",
                        __func__, completion_status, request);

                response = SAS_TASK_UNDELIVERED;

                /* See if the device has been/is being stopped. Note
                * that we ignore the quiesce state, since we are
                * concerned about the actual device state.
                */
                if (!idev)
                        status = SAS_DEVICE_UNKNOWN;
                else
                        status = SAS_ABORTED_TASK;

                if (SAS_PROTOCOL_SMP == task->task_proto)
                        set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                else
                        clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
                break;
        }

        switch (task->task_proto) {
        case SAS_PROTOCOL_SSP:
                if (task->data_dir == DMA_NONE)
                        break;
                if (task->num_scatter == 0)
                        /* 0 indicates a single dma address */
                        dma_unmap_single(&ihost->pdev->dev,
                                         request->zero_scatter_daddr,
                                         task->total_xfer_len, task->data_dir);
                else  /* unmap the sgl dma addresses */
                        dma_unmap_sg(&ihost->pdev->dev, task->scatter,
                                     task->num_scatter, task->data_dir);
                break;
        case SAS_PROTOCOL_SMP: {
                struct scatterlist *sg = &task->smp_task.smp_req;
                struct smp_req *smp_req;
                void *kaddr;

                dma_unmap_sg(&ihost->pdev->dev, sg, 1, DMA_TO_DEVICE);

                /* need to swab it back in case the command buffer is re-used */
                kaddr = kmap_atomic(sg_page(sg));
                smp_req = kaddr + sg->offset;
                sci_swab32_cpy(smp_req, smp_req, sg->length / sizeof(u32));
                kunmap_atomic(kaddr);
                break;
        }
        default:
                break;
        }

        spin_lock_irqsave(&task->task_state_lock, task_flags);

        task->task_status.resp = response;
        task->task_status.stat = status;

        if (test_bit(IREQ_COMPLETE_IN_TARGET, &request->flags)) {
                /* Normal notification (task_done) */
                task->task_state_flags |= SAS_TASK_STATE_DONE;
                task->task_state_flags &= ~SAS_TASK_STATE_PENDING;
        }
        spin_unlock_irqrestore(&task->task_state_lock, task_flags);

        /* complete the io request to the core. */
        sci_controller_complete_io(ihost, request->target_device, request);

        /* set terminated handle so it cannot be completed or
         * terminated again, and to cause any calls into abort
         * task to recognize the already completed case.
         */
        set_bit(IREQ_TERMINATED, &request->flags);

        ireq_done(ihost, request, task);
}

static void sci_request_started_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_request *ireq = container_of(sm, typeof(*ireq), sm);
        struct domain_device *dev = ireq->target_device->domain_dev;
        enum sci_base_request_states state;
        struct sas_task *task;

        /* XXX as hch said always creating an internal sas_task for tmf
         * requests would simplify the driver
         */
        task = (test_bit(IREQ_TMF, &ireq->flags)) ? NULL : isci_request_access_task(ireq);

        /* all unaccelerated request types (non ssp or ncq) handled with
         * substates
         */
        if (!task && dev->dev_type == SAS_END_DEVICE) {
                state = SCI_REQ_TASK_WAIT_TC_COMP;
        } else if (task && task->task_proto == SAS_PROTOCOL_SMP) {
                state = SCI_REQ_SMP_WAIT_RESP;
        } else if (task && sas_protocol_ata(task->task_proto) &&
                   !task->ata_task.use_ncq) {
                if (dev->sata_dev.class == ATA_DEV_ATAPI &&
                        task->ata_task.fis.command == ATA_CMD_PACKET) {
                        state = SCI_REQ_ATAPI_WAIT_H2D;
                } else if (task->data_dir == DMA_NONE) {
                        state = SCI_REQ_STP_NON_DATA_WAIT_H2D;
                } else if (task->ata_task.dma_xfer) {
                        state = SCI_REQ_STP_UDMA_WAIT_TC_COMP;
                } else /* PIO */ {
                        state = SCI_REQ_STP_PIO_WAIT_H2D;
                }
        } else {
                /* SSP or NCQ are fully accelerated, no substates */
                return;
        }
        sci_change_state(sm, state);
}

static void sci_request_completed_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_request *ireq = container_of(sm, typeof(*ireq), sm);
        struct isci_host *ihost = ireq->owning_controller;

        /* Tell the SCI_USER that the IO request is complete */
        if (!test_bit(IREQ_TMF, &ireq->flags))
                isci_request_io_request_complete(ihost, ireq,
                                                 ireq->sci_status);
        else
                isci_task_request_complete(ihost, ireq, ireq->sci_status);
}

static void sci_request_aborting_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_request *ireq = container_of(sm, typeof(*ireq), sm);

        /* Setting the abort bit in the Task Context is required by the silicon. */
        ireq->tc->abort = 1;
}

static void sci_stp_request_started_non_data_await_h2d_completion_enter(struct sci_base_state_machine *sm)
{
        struct isci_request *ireq = container_of(sm, typeof(*ireq), sm);

        ireq->target_device->working_request = ireq;
}

static void sci_stp_request_started_pio_await_h2d_completion_enter(struct sci_base_state_machine *sm)
{
        struct isci_request *ireq = container_of(sm, typeof(*ireq), sm);

        ireq->target_device->working_request = ireq;
}

static const struct sci_base_state sci_request_state_table[] = {
        [SCI_REQ_INIT] = { },
        [SCI_REQ_CONSTRUCTED] = { },
        [SCI_REQ_STARTED] = {
                .enter_state = sci_request_started_state_enter,
        },
        [SCI_REQ_STP_NON_DATA_WAIT_H2D] = {
                .enter_state = sci_stp_request_started_non_data_await_h2d_completion_enter,
        },
        [SCI_REQ_STP_NON_DATA_WAIT_D2H] = { },
        [SCI_REQ_STP_PIO_WAIT_H2D] = {
                .enter_state = sci_stp_request_started_pio_await_h2d_completion_enter,
        },
        [SCI_REQ_STP_PIO_WAIT_FRAME] = { },
        [SCI_REQ_STP_PIO_DATA_IN] = { },
        [SCI_REQ_STP_PIO_DATA_OUT] = { },
        [SCI_REQ_STP_UDMA_WAIT_TC_COMP] = { },
        [SCI_REQ_STP_UDMA_WAIT_D2H] = { },
        [SCI_REQ_TASK_WAIT_TC_COMP] = { },
        [SCI_REQ_TASK_WAIT_TC_RESP] = { },
        [SCI_REQ_SMP_WAIT_RESP] = { },
        [SCI_REQ_SMP_WAIT_TC_COMP] = { },
        [SCI_REQ_ATAPI_WAIT_H2D] = { },
        [SCI_REQ_ATAPI_WAIT_PIO_SETUP] = { },
        [SCI_REQ_ATAPI_WAIT_D2H] = { },
        [SCI_REQ_ATAPI_WAIT_TC_COMP] = { },
        [SCI_REQ_COMPLETED] = {
                .enter_state = sci_request_completed_state_enter,
        },
        [SCI_REQ_ABORTING] = {
                .enter_state = sci_request_aborting_state_enter,
        },
        [SCI_REQ_FINAL] = { },
};

static void
sci_general_request_construct(struct isci_host *ihost,
                                   struct isci_remote_device *idev,
                                   struct isci_request *ireq)
{
        sci_init_sm(&ireq->sm, sci_request_state_table, SCI_REQ_INIT);

        ireq->target_device = idev;
        ireq->protocol = SAS_PROTOCOL_NONE;
        ireq->saved_rx_frame_index = SCU_INVALID_FRAME_INDEX;

        ireq->sci_status   = SCI_SUCCESS;
        ireq->scu_status   = 0;
        ireq->post_context = 0xFFFFFFFF;
}

static enum sci_status
sci_io_request_construct(struct isci_host *ihost,
                          struct isci_remote_device *idev,
                          struct isci_request *ireq)
{
        struct domain_device *dev = idev->domain_dev;
        enum sci_status status = SCI_SUCCESS;

        /* Build the common part of the request */
        sci_general_request_construct(ihost, idev, ireq);

        if (idev->rnc.remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
                return SCI_FAILURE_INVALID_REMOTE_DEVICE;

        if (dev->dev_type == SAS_END_DEVICE)
                /* pass */;
        else if (dev_is_sata(dev))
                memset(&ireq->stp.cmd, 0, sizeof(ireq->stp.cmd));
        else if (dev_is_expander(dev->dev_type))
                /* pass */;
        else
                return SCI_FAILURE_UNSUPPORTED_PROTOCOL;

        memset(ireq->tc, 0, offsetof(struct scu_task_context, sgl_pair_ab));

        return status;
}

enum sci_status sci_task_request_construct(struct isci_host *ihost,
                                            struct isci_remote_device *idev,
                                            u16 io_tag, struct isci_request *ireq)
{
        struct domain_device *dev = idev->domain_dev;
        enum sci_status status = SCI_SUCCESS;

        /* Build the common part of the request */
        sci_general_request_construct(ihost, idev, ireq);

        if (dev->dev_type == SAS_END_DEVICE || dev_is_sata(dev)) {
                set_bit(IREQ_TMF, &ireq->flags);
                memset(ireq->tc, 0, sizeof(struct scu_task_context));

                /* Set the protocol indicator. */
                if (dev_is_sata(dev))
                        ireq->protocol = SAS_PROTOCOL_STP;
                else
                        ireq->protocol = SAS_PROTOCOL_SSP;
        } else
                status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;

        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 = sci_io_request_construct_basic_ssp(request);
        return status;
}

static enum sci_status isci_request_stp_request_construct(struct isci_request *ireq)
{
        struct sas_task *task = isci_request_access_task(ireq);
        struct host_to_dev_fis *fis = &ireq->stp.cmd;
        struct ata_queued_cmd *qc = task->uldd_task;
        enum sci_status status;

        dev_dbg(&ireq->isci_host->pdev->dev,
                "%s: ireq = %p\n",
                __func__,
                ireq);

        memcpy(fis, &task->ata_task.fis, sizeof(struct host_to_dev_fis));
        if (!task->ata_task.device_control_reg_update)
                fis->flags |= 0x80;
        fis->flags &= 0xF0;

        status = sci_io_request_construct_basic_sata(ireq);

        if (qc && (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
                   qc->tf.command == ATA_CMD_FPDMA_READ ||
                   qc->tf.command == ATA_CMD_FPDMA_RECV ||
                   qc->tf.command == ATA_CMD_FPDMA_SEND ||
                   qc->tf.command == ATA_CMD_NCQ_NON_DATA)) {
                fis->sector_count = qc->tag << 3;
                ireq->tc->type.stp.ncq_tag = qc->tag;
        }

        return status;
}

static enum sci_status
sci_io_request_construct_smp(struct device *dev,
                              struct isci_request *ireq,
                              struct sas_task *task)
{
        struct scatterlist *sg = &task->smp_task.smp_req;
        struct isci_remote_device *idev;
        struct scu_task_context *task_context;
        struct isci_port *iport;
        struct smp_req *smp_req;
        void *kaddr;
        u8 req_len;
        u32 cmd;

        kaddr = kmap_atomic(sg_page(sg));
        smp_req = kaddr + sg->offset;
        /*
         * Look at the SMP requests' header fields; for certain SAS 1.x SMP
         * functions under SAS 2.0, a zero request length really indicates
         * a non-zero default length.
         */
        if (smp_req->req_len == 0) {
                switch (smp_req->func) {
                case SMP_DISCOVER:
                case SMP_REPORT_PHY_ERR_LOG:
                case SMP_REPORT_PHY_SATA:
                case SMP_REPORT_ROUTE_INFO:
                        smp_req->req_len = 2;
                        break;
                case SMP_CONF_ROUTE_INFO:
                case SMP_PHY_CONTROL:
                case SMP_PHY_TEST_FUNCTION:
                        smp_req->req_len = 9;
                        break;
                        /* Default - zero is a valid default for 2.0. */
                }
        }
        req_len = smp_req->req_len;
        sci_swab32_cpy(smp_req, smp_req, sg->length / sizeof(u32));
        cmd = *(u32 *) smp_req;
        kunmap_atomic(kaddr);

        if (!dma_map_sg(dev, sg, 1, DMA_TO_DEVICE))
                return SCI_FAILURE;

        ireq->protocol = SAS_PROTOCOL_SMP;

        /* byte swap the smp request. */

        task_context = ireq->tc;

        idev = ireq->target_device;
        iport = idev->owning_port;

        /*
         * Fill in the TC with its required data
         * 00h
         */
        task_context->priority = 0;
        task_context->initiator_request = 1;
        task_context->connection_rate = idev->connection_rate;
        task_context->protocol_engine_index = ISCI_PEG;
        task_context->logical_port_index = iport->physical_port_index;
        task_context->protocol_type = SCU_TASK_CONTEXT_PROTOCOL_SMP;
        task_context->abort = 0;
        task_context->valid = SCU_TASK_CONTEXT_VALID;
        task_context->context_type = SCU_TASK_CONTEXT_TYPE;

        /* 04h */
        task_context->remote_node_index = idev->rnc.remote_node_index;
        task_context->command_code = 0;
        task_context->task_type = SCU_TASK_TYPE_SMP_REQUEST;

        /* 08h */
        task_context->link_layer_control = 0;
        task_context->do_not_dma_ssp_good_response = 1;
        task_context->strict_ordering = 0;
        task_context->control_frame = 1;
        task_context->timeout_enable = 0;
        task_context->block_guard_enable = 0;

        /* 0ch */
        task_context->address_modifier = 0;

        /* 10h */
        task_context->ssp_command_iu_length = req_len;

        /* 14h */
        task_context->transfer_length_bytes = 0;

        /*
         * 18h ~ 30h, protocol specific
         * since commandIU has been build by framework at this point, we just
         * copy the frist DWord from command IU to this location. */
        memcpy(&task_context->type.smp, &cmd, sizeof(u32));

        /*
         * 40h
         * "For SMP you could program it to zero. We would prefer that way
         * so that done code will be consistent." - Venki
         */
        task_context->task_phase = 0;

        ireq->post_context = (SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC |
                              (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
                               (iport->physical_port_index <<
                                SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
                              ISCI_TAG_TCI(ireq->io_tag));
        /*
         * Copy the physical address for the command buffer to the SCU Task
         * Context command buffer should not contain command header.
         */
        task_context->command_iu_upper = upper_32_bits(sg_dma_address(sg));
        task_context->command_iu_lower = lower_32_bits(sg_dma_address(sg) + sizeof(u32));

        /* SMP response comes as UF, so no need to set response IU address. */
        task_context->response_iu_upper = 0;
        task_context->response_iu_lower = 0;

        sci_change_state(&ireq->sm, SCI_REQ_CONSTRUCTED);

        return SCI_SUCCESS;
}

/*
 * 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)
{
        struct sas_task *task = isci_request_access_task(ireq);
        struct device *dev = &ireq->isci_host->pdev->dev;
        enum sci_status status = SCI_FAILURE;

        status = sci_io_request_construct_smp(dev, ireq, task);
        if (status != SCI_SUCCESS)
                dev_dbg(&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.
 * @ihost: This parameter specifies the ISCI host object
 * @request: This parameter points to the isci_request object allocated in the
 *    request construct function.
 * @idev: 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 *ihost,
                                             struct isci_request *request,
                                             struct isci_remote_device *idev)
{
        enum sci_status status = SCI_SUCCESS;
        struct sas_task *task = isci_request_access_task(request);

        dev_dbg(&ihost->pdev->dev,
                "%s: idev = 0x%p; request = %p, "
                "num_scatter = %d\n",
                __func__,
                idev,
                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(
                        &ihost->pdev->dev,
                        task->scatter,
                        task->num_scatter,
                        task->data_dir
                        );

                if (request->num_sg_entries == 0)
                        return SCI_FAILURE_INSUFFICIENT_RESOURCES;
        }

        status = sci_io_request_construct(ihost, idev, request);

        if (status != SCI_SUCCESS) {
                dev_dbg(&ihost->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_dbg(&ihost->pdev->dev,
                         "%s: unknown protocol\n", __func__);
                return SCI_FAILURE;
        }

        return status;
}

static struct isci_request *isci_request_from_tag(struct isci_host *ihost, u16 tag)
{
        struct isci_request *ireq;

        ireq = ihost->reqs[ISCI_TAG_TCI(tag)];
        ireq->io_tag = tag;
        ireq->io_request_completion = NULL;
        ireq->flags = 0;
        ireq->num_sg_entries = 0;

        return ireq;
}

struct isci_request *isci_io_request_from_tag(struct isci_host *ihost,
                                              struct sas_task *task,
                                              u16 tag)
{
        struct isci_request *ireq;

        ireq = isci_request_from_tag(ihost, tag);
        ireq->ttype_ptr.io_task_ptr = task;
        clear_bit(IREQ_TMF, &ireq->flags);
        task->lldd_task = ireq;

        return ireq;
}

struct isci_request *isci_tmf_request_from_tag(struct isci_host *ihost,
                                               struct isci_tmf *isci_tmf,
                                               u16 tag)
{
        struct isci_request *ireq;

        ireq = isci_request_from_tag(ihost, tag);
        ireq->ttype_ptr.tmf_task_ptr = isci_tmf;
        set_bit(IREQ_TMF, &ireq->flags);

        return ireq;
}

int isci_request_execute(struct isci_host *ihost, struct isci_remote_device *idev,
                         struct sas_task *task, struct isci_request *ireq)
{
        enum sci_status status;
        unsigned long flags;
        int ret = 0;

        status = isci_io_request_build(ihost, ireq, idev);
        if (status != SCI_SUCCESS) {
                dev_dbg(&ihost->pdev->dev,
                         "%s: request_construct failed - status = 0x%x\n",
                         __func__,
                         status);
                return status;
        }

        spin_lock_irqsave(&ihost->scic_lock, flags);

        if (test_bit(IDEV_IO_NCQERROR, &idev->flags)) {

                if (isci_task_is_ncq_recovery(task)) {

                        /* The device is in an NCQ recovery state.  Issue the
                         * request on the task side.  Note that it will
                         * complete on the I/O request side because the
                         * request was built that way (ie.
                         * ireq->is_task_management_request is false).
                         */
                        status = sci_controller_start_task(ihost,
                                                            idev,
                                                            ireq);
                } else {
                        status = SCI_FAILURE;
                }
        } else {
                /* send the request, let the core assign the IO TAG.    */
                status = sci_controller_start_io(ihost, idev,
                                                  ireq);
        }

        if (status != SCI_SUCCESS &&
            status != SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
                dev_dbg(&ihost->pdev->dev,
                         "%s: failed request start (0x%x)\n",
                         __func__, status);
                spin_unlock_irqrestore(&ihost->scic_lock, flags);
                return status;
        }
        /* Either I/O started OK, or the core has signaled that
         * the device needs a target reset.
         */
        if (status != SCI_SUCCESS) {
                /* The request did not really start in the
                 * hardware, so clear the request handle
                 * here so no terminations will be done.
                 */
                set_bit(IREQ_TERMINATED, &ireq->flags);
        }
        spin_unlock_irqrestore(&ihost->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.
                 */
                sas_task_abort(task);

                /* Change the status, since we are holding
                 * the I/O until it is managed by the SCSI
                 * error handler.
                 */
                status = SCI_SUCCESS;
        }

        return ret;
}