isci: make sgl explicit/aligned request object member

Towards unifying request objects we need all members to be defined in the
object and not carved out of anonymous buffer space.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

7 files changed, 19 insertions, 64 deletions

diff --git a/drivers/scsi/isci/core/scic_sds_request.c b/drivers/scsi/isci/core/scic_sds_request.c
index fd7bd334fa4b..189a7999726c 100644
--- a/drivers/scsi/isci/core/scic_sds_request.c
+++ b/drivers/scsi/isci/core/scic_sds_request.c
@@ -212,8 +212,7 @@ static u32 scic_sds_ssp_request_get_object_size(void)
         return sizeof(struct scic_sds_request)
                + scic_ssp_io_request_get_object_size()
                + sizeof(struct scu_task_context)
-               + SMP_CACHE_BYTES
-               + sizeof(struct scu_sgl_element_pair) * SCU_MAX_SGL_ELEMENT_PAIRS;
+               + SMP_CACHE_BYTES;
 }
 
 /**
@@ -239,7 +238,7 @@ static struct scu_sgl_element_pair *scic_sds_request_get_sgl_element_pair(
                 return &task_context->sgl_pair_cd;
         }
 
-        return &sci_req->sgl_element_pair_buffer[sgl_pair_index - 2];
+        return &sci_req->sg_table[sgl_pair_index - 2];
 }
 
 /**
@@ -328,11 +327,6 @@ static void scic_sds_ssp_io_request_assign_buffers(
                 scic_sds_ssp_request_get_command_buffer(sci_req);
         sci_req->response_buffer =
                 scic_sds_ssp_request_get_response_buffer(sci_req);
-        sci_req->sgl_element_pair_buffer =
-                scic_sds_ssp_request_get_sgl_element_buffer(sci_req);
-        sci_req->sgl_element_pair_buffer =
-                PTR_ALIGN(sci_req->sgl_element_pair_buffer,
-                          sizeof(struct scu_sgl_element_pair));
 
         if (sci_req->was_tag_assigned_by_user == false) {
                 sci_req->task_context_buffer =
@@ -535,7 +529,6 @@ static void scic_sds_ssp_task_request_assign_buffers(
                 scic_sds_ssp_task_request_get_command_buffer(sci_req);
         sci_req->response_buffer =
                 scic_sds_ssp_task_request_get_response_buffer(sci_req);
-        sci_req->sgl_element_pair_buffer = NULL;
 
         if (sci_req->was_tag_assigned_by_user == false) {
                 sci_req->task_context_buffer =
diff --git a/drivers/scsi/isci/core/scic_sds_request.h b/drivers/scsi/isci/core/scic_sds_request.h
index c93f3ed8946d..83d737adbc48 100644
--- a/drivers/scsi/isci/core/scic_sds_request.h
+++ b/drivers/scsi/isci/core/scic_sds_request.h
@@ -60,6 +60,7 @@
 #include "sci_base_state_machine.h"
 #include "scu_task_context.h"
 #include "scic_sds_stp_request.h"
+#include "scu_constants.h"
 
 struct scic_sds_controller;
 struct scic_sds_remote_device;
@@ -183,7 +184,10 @@ struct scic_sds_request {
         void *command_buffer;
         void *response_buffer;
         struct scu_task_context *task_context_buffer;
-        struct scu_sgl_element_pair *sgl_element_pair_buffer;
+
+        /* could be larger with sg chaining */
+        #define SCU_SGL_SIZE ((SCU_IO_REQUEST_SGE_COUNT + 1) / 2)
+        struct scu_sgl_element_pair sg_table[SCU_SGL_SIZE] __attribute__ ((aligned(32)));
 
         /**
          * This field indicates if this request is a task management request or
@@ -328,14 +332,6 @@ struct scic_sds_io_request_state_handler {
 extern const struct sci_base_state scic_sds_io_request_started_task_mgmt_substate_table[];
 
 /**
- *
- *
- * This macro returns the maximum number of SGL element paris that we will
- * support in a single IO request.
- */
-#define SCU_MAX_SGL_ELEMENT_PAIRS ((SCU_IO_REQUEST_SGE_COUNT + 1) / 2)
-
-/**
  * scic_sds_request_get_controller() -
  *
  * This macro will return the controller for this io request object
diff --git a/drivers/scsi/isci/core/scic_sds_smp_request.c b/drivers/scsi/isci/core/scic_sds_smp_request.c
index 1f8773d3b793..cb1adef1d559 100644
--- a/drivers/scsi/isci/core/scic_sds_smp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_smp_request.c
@@ -131,7 +131,6 @@ void scic_sds_smp_request_assign_buffers(
                 scic_sds_smp_request_get_command_buffer(sci_req);
         sci_req->response_buffer =
                 scic_sds_smp_request_get_response_buffer(sci_req);
-        sci_req->sgl_element_pair_buffer = NULL;
 
         if (sci_req->was_tag_assigned_by_user == false) {
                 sci_req->task_context_buffer =
diff --git a/drivers/scsi/isci/core/scic_sds_stp_request.c b/drivers/scsi/isci/core/scic_sds_stp_request.c
index 7dba40fc2585..013af11df62b 100644
--- a/drivers/scsi/isci/core/scic_sds_stp_request.c
+++ b/drivers/scsi/isci/core/scic_sds_stp_request.c
@@ -106,18 +106,6 @@
                  ))
 
 /**
- * scic_sds_stp_request_get_sgl_element_buffer() -
- *
- * This macro returns the address of the sgl elment pairs in the io request
- * memory buffer
- */
-#define scic_sds_stp_request_get_sgl_element_buffer(memory) \
-        ((struct scu_sgl_element_pair *)(\
-                 ((char *)(scic_sds_stp_request_get_task_context_buffer(memory))) \
-                 + sizeof(struct scu_task_context) \
-                 ))
-
-/**
  *
  *
  * This method return the memory space required for STP PIO requests. u32
@@ -128,8 +116,7 @@ u32 scic_sds_stp_request_get_object_size(void)
                + sizeof(struct host_to_dev_fis)
                + sizeof(struct dev_to_host_fis)
                + sizeof(struct scu_task_context)
-               + SMP_CACHE_BYTES
-               + sizeof(struct scu_sgl_element_pair) * SCU_MAX_SGL_ELEMENT_PAIRS;
+               + SMP_CACHE_BYTES;
 }
 
 void scic_sds_stp_request_assign_buffers(struct scic_sds_request *sci_req)
@@ -138,9 +125,6 @@ void scic_sds_stp_request_assign_buffers(struct scic_sds_request *sci_req)
 
         sci_req->command_buffer = scic_sds_stp_request_get_h2d_reg_buffer(stp_req);
         sci_req->response_buffer = scic_sds_stp_request_get_response_buffer(stp_req);
-        sci_req->sgl_element_pair_buffer = scic_sds_stp_request_get_sgl_element_buffer(stp_req);
-        sci_req->sgl_element_pair_buffer = PTR_ALIGN(sci_req->sgl_element_pair_buffer,
-                                                     sizeof(struct scu_sgl_element_pair));
 
         if (sci_req->was_tag_assigned_by_user == false) {
                 sci_req->task_context_buffer =
diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index e01c2c98f4e9..9dd971a3fbb2 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -200,14 +200,10 @@ static enum sci_status isci_io_request_build(
         /* build the common request object. For now,
          * we will let the core allocate the IO tag.
          */
-        status = scic_io_request_construct(
-                &isci_host->sci,
-                sci_device,
-                SCI_CONTROLLER_INVALID_IO_TAG,
-                request,
-                request->sci_request_mem_ptr,
-                (struct scic_sds_request **)&request->sci_request_handle
-                );
+        status = scic_io_request_construct(&isci_host->sci, sci_device,
+                                           SCI_CONTROLLER_INVALID_IO_TAG,
+                                           request, request->sci_req,
+                                           &request->sci_request_handle);
 
         if (status != SCI_SUCCESS) {
                 dev_warn(&isci_host->pdev->dev,
@@ -277,8 +273,6 @@ static int isci_request_alloc_core(
 
         /* initialize the request object.       */
         spin_lock_init(&request->state_lock);
-        request->sci_request_mem_ptr = ((u8 *)request) +
-                                       sizeof(struct isci_request);
         request->request_daddr = handle;
         request->isci_host = isci_host;
         request->isci_device = isci_device;
diff --git a/drivers/scsi/isci/request.h b/drivers/scsi/isci/request.h
index 9c97715e54d8..ddfbf71c97e5 100644
--- a/drivers/scsi/isci/request.h
+++ b/drivers/scsi/isci/request.h
@@ -53,10 +53,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if !defined(_ISCI_REQUEST_H_)
+#ifndef _ISCI_REQUEST_H_
 #define _ISCI_REQUEST_H_
 
 #include "isci.h"
+#include "scic_sds_request.h"
 
 /**
  * struct isci_request_status - This enum defines the possible states of an I/O
@@ -80,16 +81,8 @@ enum task_type {
         tmf_task = 1
 };
 
-/**
- * struct isci_request - This class represents the request object used to track
- *    IO, smp and TMF request internal. It wraps the SCIC request object.
- *
- *
- */
 struct isci_request {
-
         struct scic_sds_request *sci_request_handle;
-
         enum isci_request_status status;
         enum task_type ttype;
         unsigned short io_tag;
@@ -105,7 +98,6 @@ struct isci_request {
         struct list_head completed_node;
         /* For use in the reqs_in_process list: */
         struct list_head dev_node;
-        void *sci_request_mem_ptr;
         spinlock_t state_lock;
         dma_addr_t request_daddr;
         dma_addr_t zero_scatter_daddr;
@@ -123,6 +115,7 @@ struct isci_request {
          * TMF was aborting is guaranteed to have completed.
          */
         struct completion *io_request_completion;
+        struct scic_sds_request sci_req[0] ____cacheline_aligned;
 };
 
 /**
diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
index 12f2df947362..7d5f79378452 100644
--- a/drivers/scsi/isci/task.c
+++ b/drivers/scsi/isci/task.c
@@ -298,14 +298,10 @@ static enum sci_status isci_task_request_build(
                 goto out;
 
         /* let the core do it's construct. */
-        status = scic_task_request_construct(
-                &isci_host->sci,
-                sci_device,
-                SCI_CONTROLLER_INVALID_IO_TAG,
-                request,
-                request->sci_request_mem_ptr,
-                &request->sci_request_handle
-                );
+        status = scic_task_request_construct(&isci_host->sci, sci_device,
+                                             SCI_CONTROLLER_INVALID_IO_TAG,
+                                             request, &request->sci_req,
+                                             &request->sci_request_handle);
 
         if (status != SCI_SUCCESS) {
                 dev_warn(&isci_host->pdev->dev,