isci: rename / clean up scic_sds_stp_request

* Rename scic_sds_stp_request to isci_stp_request
* Remove the unused fields and union indirection

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

2 files changed, 89 insertions, 142 deletions

diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 3c7ed4e61b4a..8520626b02fa 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -433,24 +433,20 @@ static enum sci_status
 scic_sds_stp_pio_request_construct(struct scic_sds_request *sci_req,
                                    bool copy_rx_frame)
 {
-        struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
-        struct scic_sds_stp_pio_request *pio = &stp_req->type.pio;
+        struct isci_stp_request *stp_req = &sci_req->stp.req;
 
         scu_stp_raw_request_construct_task_context(sci_req);
 
-        pio->current_transfer_bytes = 0;
-        pio->ending_error = 0;
-        pio->ending_status = 0;
-
-        pio->request_current.sgl_offset = 0;
-        pio->request_current.sgl_set = SCU_SGL_ELEMENT_PAIR_A;
+        stp_req->status = 0;
+        stp_req->sgl.offset = 0;
+        stp_req->sgl.set = SCU_SGL_ELEMENT_PAIR_A;
 
         if (copy_rx_frame) {
                 scic_sds_request_build_sgl(sci_req);
-                pio->request_current.sgl_index = 0;
+                stp_req->sgl.index = 0;
         } else {
                 /* The user does not want the data copied to the SGL buffer location */
-                pio->request_current.sgl_index = -1;
+                stp_req->sgl.index = -1;
         }
 
         return SCI_SUCCESS;
@@ -1151,22 +1147,22 @@ void scic_stp_io_request_set_ncq_tag(struct scic_sds_request *req,
         req->tc->type.stp.ncq_tag = ncq_tag;
 }
 
-static struct scu_sgl_element *pio_sgl_next(struct scic_sds_stp_request *stp_req)
+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 scic_sds_request *sci_req = to_sci_req(stp_req);
-        struct scic_sds_request_pio_sgl *pio_sgl = &stp_req->type.pio.request_current;
+        struct isci_stp_pio_sgl *pio_sgl = &stp_req->sgl;
 
-        sgl_pair = to_sgl_element_pair(sci_req, pio_sgl->sgl_index);
+        sgl_pair = to_sgl_element_pair(sci_req, pio_sgl->index);
         if (!sgl_pair)
                 sgl = NULL;
-        else if (pio_sgl->sgl_set == SCU_SGL_ELEMENT_PAIR_A) {
+        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->sgl_set = SCU_SGL_ELEMENT_PAIR_B;
+                        pio_sgl->set = SCU_SGL_ELEMENT_PAIR_B;
                         sgl = &sgl_pair->B;
                 }
         } else {
@@ -1174,9 +1170,9 @@ static struct scu_sgl_element *pio_sgl_next(struct scic_sds_stp_request *stp_req
                     sgl_pair->next_pair_upper == 0) {
                         sgl = NULL;
                 } else {
-                        pio_sgl->sgl_index++;
-                        pio_sgl->sgl_set = SCU_SGL_ELEMENT_PAIR_A;
-                        sgl_pair = to_sgl_element_pair(sci_req, pio_sgl->sgl_index);
+                        pio_sgl->index++;
+                        pio_sgl->set = SCU_SGL_ELEMENT_PAIR_A;
+                        sgl_pair = to_sgl_element_pair(sci_req, pio_sgl->index);
                         sgl = &sgl_pair->A;
                 }
         }
@@ -1221,7 +1217,7 @@ static enum sci_status scic_sds_stp_request_pio_data_out_trasmit_data_frame(
         struct scic_sds_request *sci_req,
         u32 length)
 {
-        struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
+        struct isci_stp_request *stp_req = &sci_req->stp.req;
         struct scu_task_context *task_context = sci_req->tc;
         struct scu_sgl_element_pair *sgl_pair;
         struct scu_sgl_element *current_sgl;
@@ -1229,8 +1225,8 @@ static enum sci_status scic_sds_stp_request_pio_data_out_trasmit_data_frame(
         /* 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(sci_req, stp_req->type.pio.request_current.sgl_index);
-        if (stp_req->type.pio.request_current.sgl_set == SCU_SGL_ELEMENT_PAIR_A)
+        sgl_pair = to_sgl_element_pair(sci_req, 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;
@@ -1247,54 +1243,48 @@ static enum sci_status scic_sds_stp_request_pio_data_out_trasmit_data_frame(
 
 static enum sci_status scic_sds_stp_request_pio_data_out_transmit_data(struct scic_sds_request *sci_req)
 {
-
-        struct scu_sgl_element *current_sgl;
-        u32 sgl_offset;
-        u32 remaining_bytes_in_current_sgl = 0;
-        enum sci_status status = SCI_SUCCESS;
-        struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
+        struct isci_stp_request *stp_req = &sci_req->stp.req;
         struct scu_sgl_element_pair *sgl_pair;
+        struct scu_sgl_element *sgl;
+        enum sci_status status;
+        u32 offset;
+        u32 len = 0;
 
-        sgl_offset = stp_req->type.pio.request_current.sgl_offset;
-        sgl_pair = to_sgl_element_pair(sci_req, stp_req->type.pio.request_current.sgl_index);
+        offset = stp_req->sgl.offset;
+        sgl_pair = to_sgl_element_pair(sci_req, stp_req->sgl.index);
         if (WARN_ONCE(!sgl_pair, "%s: null sgl element", __func__))
                 return SCI_FAILURE;
 
-        if (stp_req->type.pio.request_current.sgl_set == SCU_SGL_ELEMENT_PAIR_A) {
-                current_sgl = &sgl_pair->A;
-                remaining_bytes_in_current_sgl = sgl_pair->A.length - sgl_offset;
+        if (stp_req->sgl.set == SCU_SGL_ELEMENT_PAIR_A) {
+                sgl = &sgl_pair->A;
+                len = sgl_pair->A.length - offset;
         } else {
-                current_sgl = &sgl_pair->B;
-                remaining_bytes_in_current_sgl = sgl_pair->B.length - sgl_offset;
+                sgl = &sgl_pair->B;
+                len = sgl_pair->B.length - offset;
         }
 
-        if (stp_req->type.pio.pio_transfer_bytes > 0) {
-                if (stp_req->type.pio.pio_transfer_bytes >= remaining_bytes_in_current_sgl) {
-                        /* recycle the TC and send the H2D Data FIS from (current sgl + sgl_offset) and length = remaining_bytes_in_current_sgl */
-                        status = scic_sds_stp_request_pio_data_out_trasmit_data_frame(sci_req, remaining_bytes_in_current_sgl);
-                        if (status == SCI_SUCCESS) {
-                                stp_req->type.pio.pio_transfer_bytes -= remaining_bytes_in_current_sgl;
-
-                                /* update the current sgl, sgl_offset and save for future */
-                                current_sgl = pio_sgl_next(stp_req);
-                                sgl_offset = 0;
-                        }
-                } else if (stp_req->type.pio.pio_transfer_bytes < remaining_bytes_in_current_sgl) {
-                        /* recycle the TC and send the H2D Data FIS from (current sgl + sgl_offset) and length = type.pio.pio_transfer_bytes */
-                        scic_sds_stp_request_pio_data_out_trasmit_data_frame(sci_req, stp_req->type.pio.pio_transfer_bytes);
+        if (stp_req->pio_len == 0)
+                return SCI_SUCCESS;
 
-                        if (status == SCI_SUCCESS) {
-                                /* Sgl offset will be adjusted and saved for future */
-                                sgl_offset += stp_req->type.pio.pio_transfer_bytes;
-                                current_sgl->address_lower += stp_req->type.pio.pio_transfer_bytes;
-                                stp_req->type.pio.pio_transfer_bytes = 0;
-                        }
-                }
+        if (stp_req->pio_len >= len) {
+                status = scic_sds_stp_request_pio_data_out_trasmit_data_frame(sci_req, 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) {
+                scic_sds_stp_request_pio_data_out_trasmit_data_frame(sci_req, 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;
         }
 
-        if (status == SCI_SUCCESS) {
-                stp_req->type.pio.request_current.sgl_offset = sgl_offset;
-        }
+        stp_req->sgl.offset = offset;
 
         return status;
 }
@@ -1309,7 +1299,7 @@ static enum sci_status scic_sds_stp_request_pio_data_out_transmit_data(struct sc
  * specified data region. enum sci_status
  */
 static enum sci_status
-scic_sds_stp_request_pio_data_in_copy_data_buffer(struct scic_sds_stp_request *stp_req,
+scic_sds_stp_request_pio_data_in_copy_data_buffer(struct isci_stp_request *stp_req,
                                                   u8 *data_buf, u32 len)
 {
         struct scic_sds_request *sci_req;
@@ -1356,7 +1346,7 @@ scic_sds_stp_request_pio_data_in_copy_data_buffer(struct scic_sds_stp_request *s
  * Copy the data buffer to the io request data region. enum sci_status
  */
 static enum sci_status scic_sds_stp_request_pio_data_in_copy_data(
-        struct scic_sds_stp_request *sci_req,
+        struct isci_stp_request *stp_req,
         u8 *data_buffer)
 {
         enum sci_status status;
@@ -1364,19 +1354,19 @@ static enum sci_status scic_sds_stp_request_pio_data_in_copy_data(
         /*
          * If there is less than 1K remaining in the transfer request
          * copy just the data for the transfer */
-        if (sci_req->type.pio.pio_transfer_bytes < SCU_MAX_FRAME_BUFFER_SIZE) {
+        if (stp_req->pio_len < SCU_MAX_FRAME_BUFFER_SIZE) {
                 status = scic_sds_stp_request_pio_data_in_copy_data_buffer(
-                        sci_req, data_buffer, sci_req->type.pio.pio_transfer_bytes);
+                        stp_req, data_buffer, stp_req->pio_len);
 
                 if (status == SCI_SUCCESS)
-                        sci_req->type.pio.pio_transfer_bytes = 0;
+                        stp_req->pio_len = 0;
         } else {
                 /* We are transfering the whole frame so copy */
                 status = scic_sds_stp_request_pio_data_in_copy_data_buffer(
-                        sci_req, data_buffer, SCU_MAX_FRAME_BUFFER_SIZE);
+                        stp_req, data_buffer, SCU_MAX_FRAME_BUFFER_SIZE);
 
                 if (status == SCI_SUCCESS)
-                        sci_req->type.pio.pio_transfer_bytes -= SCU_MAX_FRAME_BUFFER_SIZE;
+                        stp_req->pio_len -= SCU_MAX_FRAME_BUFFER_SIZE;
         }
 
         return status;
@@ -1419,18 +1409,18 @@ pio_data_out_tx_done_tc_event(struct scic_sds_request *sci_req,
 {
         enum sci_status status = SCI_SUCCESS;
         bool all_frames_transferred = false;
-        struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
+        struct isci_stp_request *stp_req = &sci_req->stp.req;
 
         switch (SCU_GET_COMPLETION_TL_STATUS(completion_code)) {
         case SCU_MAKE_COMPLETION_STATUS(SCU_TASK_DONE_GOOD):
                 /* Transmit data */
-                if (stp_req->type.pio.pio_transfer_bytes != 0) {
+                if (stp_req->pio_len != 0) {
                         status = scic_sds_stp_request_pio_data_out_transmit_data(sci_req);
                         if (status == SCI_SUCCESS) {
-                                if (stp_req->type.pio.pio_transfer_bytes == 0)
+                                if (stp_req->pio_len == 0)
                                         all_frames_transferred = true;
                         }
-                } else if (stp_req->type.pio.pio_transfer_bytes == 0) {
+                } 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
@@ -1507,7 +1497,7 @@ scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
                                   u32 frame_index)
 {
         struct scic_sds_controller *scic = sci_req->owning_controller;
-        struct scic_sds_stp_request *stp_req = &sci_req->stp.req;
+        struct isci_stp_request *stp_req = &sci_req->stp.req;
         enum sci_base_request_states state;
         enum sci_status status;
         ssize_t word_cnt;
@@ -1727,16 +1717,16 @@ scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
                          */
 
                         /* transfer_count: first 16bits in the 4th dword */
-                        stp_req->type.pio.pio_transfer_bytes = frame_buffer[3] & 0xffff;
+                        stp_req->pio_len = frame_buffer[3] & 0xffff;
 
-                        /* ending_status: 4th byte in the 3rd dword */
-                        stp_req->type.pio.ending_status = (frame_buffer[2] >> 24) & 0xff;
+                        /* status: 4th byte in the 3rd dword */
+                        stp_req->status = (frame_buffer[2] >> 24) & 0xff;
 
                         scic_sds_controller_copy_sata_response(&sci_req->stp.rsp,
                                                                frame_header,
                                                                frame_buffer);
 
-                        sci_req->stp.rsp.status = stp_req->type.pio.ending_status;
+                        sci_req->stp.rsp.status = stp_req->status;
 
                         /* The next state is dependent on whether the
                          * request was PIO Data-in or Data out
@@ -1839,9 +1829,9 @@ scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
                         return status;
                 }
 
-                if (stp_req->type.pio.request_current.sgl_index < 0) {
+                if (stp_req->sgl.index < 0) {
                         sci_req->saved_rx_frame_index = frame_index;
-                        stp_req->type.pio.pio_transfer_bytes = 0;
+                        stp_req->pio_len = 0;
                 } else {
                         scic_sds_unsolicited_frame_control_get_buffer(&scic->uf_control,
                                                                       frame_index,
@@ -1857,11 +1847,10 @@ scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
                 /* Check for the end of the transfer, are there more
                  * bytes remaining for this data transfer
                  */
-                if (status != SCI_SUCCESS ||
-                    stp_req->type.pio.pio_transfer_bytes != 0)
+                if (status != SCI_SUCCESS || stp_req->pio_len != 0)
                         return status;
 
-                if ((stp_req->type.pio.ending_status & ATA_BUSY) == 0) {
+                if ((stp_req->status & ATA_BUSY) == 0) {
                         scic_sds_request_set_status(sci_req,
                                                     SCU_TASK_DONE_CHECK_RESPONSE,
                                                     SCI_FAILURE_IO_RESPONSE_VALID);
diff --git a/drivers/scsi/isci/request.h b/drivers/scsi/isci/request.h
index 7628decbd535..7fd98531d1f2 100644
--- a/drivers/scsi/isci/request.h
+++ b/drivers/scsi/isci/request.h
@@ -89,67 +89,25 @@ enum sci_request_protocol {
         SCIC_STP_PROTOCOL
 }; /* XXX remove me, use sas_task.{dev|task_proto} instead */;
 
-struct scic_sds_stp_request {
-        union {
-                u32 ncq;
-
-                u32 udma;
-
-                struct scic_sds_stp_pio_request {
-                        /*
-                         * Total transfer for the entire PIO request recorded
-                         * at request constuction time.
-                         *
-                         * @todo Should we just decrement this value for each
-                         * byte of data transitted or received to elemenate
-                         * the current_transfer_bytes field?
-                         */
-                        u32 total_transfer_bytes;
-
-                        /*
-                         * Total number of bytes received/transmitted in data
-                         * frames since the start of the IO request.  At the
-                         * end of the IO request this should equal the
-                         * total_transfer_bytes.
-                         */
-                        u32 current_transfer_bytes;
-
-                        /*
-                         * The number of bytes requested in the in the PIO
-                         * setup.
-                         */
-                        u32 pio_transfer_bytes;
-
-                        /*
-                         * PIO Setup ending status value to tell us if we need
-                         * to wait for another FIS or if the transfer is
-                         * complete. On the receipt of a D2H FIS this will be
-                         * the status field of that FIS.
-                         */
-                        u8 ending_status;
-
-                        /*
-                         * On receipt of a D2H FIS this will be the ending
-                         * error field if the ending_status has the
-                         * SATA_STATUS_ERR bit set.
-                         */
-                        u8 ending_error;
-
-                        struct scic_sds_request_pio_sgl {
-                                int sgl_index;
-                                u8 sgl_set;
-                                u32 sgl_offset;
-                        } request_current;
-                } pio;
-
-                struct {
-                        /*
-                         * The number of bytes requested in the PIO setup
-                         * before CDB data frame.
-                         */
-                        u32 device_preferred_cdb_length;
-                } packet;
-        } type;
+/**
+ * isci_stp_request - extra request infrastructure to handle pio/atapi protocol
+ * @pio_len - number of bytes requested at PIO setup
+ * @status - pio setup ending status value to tell us if we need
+ *           to wait for another fis or if the transfer is complete.  Upon 
+ *           receipt of a d2h fis this will be the status field of that fis.
+ * @sgl - track pio transfer progress as we iterate through the sgl
+ * @device_cdb_len - atapi device advertises it's transfer constraints at setup
+ */
+struct isci_stp_request {
+        u32 pio_len;
+        u8 status;
+
+        struct isci_stp_pio_sgl {
+                int index;
+                u8 set;
+                u32 offset;
+        } sgl;
+        u32 device_cdb_len;
 };
 
 struct scic_sds_request {
@@ -235,14 +193,14 @@ struct scic_sds_request {
                 } smp;
 
                 struct {
-                        struct scic_sds_stp_request req;
+                        struct isci_stp_request req;
                         struct host_to_dev_fis cmd;
                         struct dev_to_host_fis rsp;
                 } stp;
         };
 };
 
-static inline struct scic_sds_request *to_sci_req(struct scic_sds_stp_request *stp_req)
+static inline struct scic_sds_request *to_sci_req(struct isci_stp_request *stp_req)
 {
         struct scic_sds_request *sci_req;