isci: preallocate requests

the dma_pool interface is optimized for object_size << page_size which
is not the case with isci_request objects and the dma_pool routines show
up in the top of the profile.

The old io_request_table which tracked whether tci slots were in-flight
or not is replaced with an IREQ_ACTIVE flag per request.

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

6 files changed, 85 insertions, 139 deletions

diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c
index c99fab53dd0c..0884ae3253e5 100644
--- a/drivers/scsi/isci/host.c
+++ b/drivers/scsi/isci/host.c
@@ -255,14 +255,14 @@ static bool scic_sds_controller_error_isr(struct scic_sds_controller *scic)
 static void scic_sds_controller_task_completion(struct scic_sds_controller *scic,
                                                 u32 completion_entry)
 {
-        u32 index;
-        struct scic_sds_request *sci_req;
-
-        index = SCU_GET_COMPLETION_INDEX(completion_entry);
-        sci_req = scic->io_request_table[index];
+        u32 index = SCU_GET_COMPLETION_INDEX(completion_entry);
+        struct isci_host *ihost = scic_to_ihost(scic);
+        struct isci_request *ireq = ihost->reqs[index];
+        struct scic_sds_request *sci_req = &ireq->sci;
 
         /* Make sure that we really want to process this IO request */
-        if (sci_req && sci_req->io_tag != SCI_CONTROLLER_INVALID_IO_TAG &&
+        if (test_bit(IREQ_ACTIVE, &ireq->flags) &&
+            sci_req->io_tag != SCI_CONTROLLER_INVALID_IO_TAG &&
             ISCI_TAG_SEQ(sci_req->io_tag) == scic->io_request_sequence[index])
                 /* Yep this is a valid io request pass it along to the io request handler */
                 scic_sds_io_request_tc_completion(sci_req, completion_entry);
@@ -280,7 +280,7 @@ static void scic_sds_controller_sdma_completion(struct scic_sds_controller *scic
         switch (scu_get_command_request_type(completion_entry)) {
         case SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC:
         case SCU_CONTEXT_COMMAND_REQUEST_TYPE_DUMP_TC:
-                io_request = scic->io_request_table[index];
+                io_request = &scic_to_ihost(scic)->reqs[index]->sci;
                 dev_warn(scic_to_dev(scic),
                          "%s: SCIC SDS Completion type SDMA %x for io request "
                          "%p\n",
@@ -418,7 +418,7 @@ static void scic_sds_controller_event_completion(struct scic_sds_controller *sci
                 break;
 
         case SCU_EVENT_TYPE_TRANSPORT_ERROR:
-                io_request = scic->io_request_table[index];
+                io_request = &ihost->reqs[index]->sci;
                 scic_sds_io_request_event_handler(io_request, completion_entry);
                 break;
 
@@ -426,7 +426,7 @@ static void scic_sds_controller_event_completion(struct scic_sds_controller *sci
                 switch (scu_get_event_specifier(completion_entry)) {
                 case SCU_EVENT_SPECIFIC_SMP_RESPONSE_NO_PE:
                 case SCU_EVENT_SPECIFIC_TASK_TIMEOUT:
-                        io_request = scic->io_request_table[index];
+                        io_request = &ihost->reqs[index]->sci;
                         if (io_request != NULL)
                                 scic_sds_io_request_event_handler(io_request, completion_entry);
                         else
@@ -1187,9 +1187,6 @@ static void isci_host_completion_routine(unsigned long data)
                 spin_lock_irq(&isci_host->scic_lock);
                 isci_free_tag(isci_host, request->sci.io_tag);
                 spin_unlock_irq(&isci_host->scic_lock);
-
-                /* Free the request object. */
-                isci_request_free(isci_host, request);
         }
         list_for_each_entry_safe(request, next_request, &errored_request_list,
                                  completed_node) {
@@ -1227,9 +1224,6 @@ static void isci_host_completion_routine(unsigned long data)
                         list_del_init(&request->dev_node);
                         isci_free_tag(isci_host, request->sci.io_tag);
                         spin_unlock_irq(&isci_host->scic_lock);
-
-                        /* Free the request object. */
-                        isci_request_free(isci_host, request);
                 }
         }
 
@@ -2469,13 +2463,6 @@ int isci_host_init(struct isci_host *isci_host)
         if (err)
                 return err;
 
-        isci_host->dma_pool = dmam_pool_create(DRV_NAME, &isci_host->pdev->dev,
-                                               sizeof(struct isci_request),
-                                               SLAB_HWCACHE_ALIGN, 0);
-
-        if (!isci_host->dma_pool)
-                return -ENOMEM;
-
         for (i = 0; i < SCI_MAX_PORTS; i++)
                 isci_port_init(&isci_host->ports[i], isci_host, i);
 
@@ -2489,6 +2476,25 @@ int isci_host_init(struct isci_host *isci_host)
                 INIT_LIST_HEAD(&idev->node);
         }
 
+        for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
+                struct isci_request *ireq;
+                dma_addr_t dma;
+
+                ireq = dmam_alloc_coherent(&isci_host->pdev->dev,
+                                           sizeof(struct isci_request), &dma,
+                                           GFP_KERNEL);
+                if (!ireq)
+                        return -ENOMEM;
+
+                ireq->sci.tc = &isci_host->sci.task_context_table[i];
+                ireq->sci.owning_controller = &isci_host->sci;
+                spin_lock_init(&ireq->state_lock);
+                ireq->request_daddr = dma;
+                ireq->isci_host = isci_host;
+
+                isci_host->reqs[i] = ireq;
+        }
+
         return 0;
 }
 
@@ -2602,12 +2608,13 @@ struct scic_sds_request *scic_request_by_tag(struct scic_sds_controller *scic, u
         task_index = ISCI_TAG_TCI(io_tag);
 
         if (task_index < scic->task_context_entries) {
-                if (scic->io_request_table[task_index] != NULL) {
+                struct isci_request *ireq = scic_to_ihost(scic)->reqs[task_index];
+
+                if (test_bit(IREQ_ACTIVE, &ireq->flags)) {
                         task_sequence = ISCI_TAG_SEQ(io_tag);
 
-                        if (task_sequence == scic->io_request_sequence[task_index]) {
-                                return scic->io_request_table[task_index];
-                        }
+                        if (task_sequence == scic->io_request_sequence[task_index])
+                                return &ireq->sci;
                 }
         }
 
@@ -2820,7 +2827,7 @@ enum sci_status scic_controller_start_io(struct scic_sds_controller *scic,
         if (status != SCI_SUCCESS)
                 return status;
 
-        scic->io_request_table[ISCI_TAG_TCI(req->io_tag)] = req;
+        set_bit(IREQ_ACTIVE, &sci_req_to_ireq(req)->flags);
         scic_sds_controller_post_request(scic, scic_sds_request_get_post_context(req));
         return SCI_SUCCESS;
 }
@@ -2897,7 +2904,7 @@ enum sci_status scic_controller_complete_io(
                         return status;
 
                 index = ISCI_TAG_TCI(request->io_tag);
-                scic->io_request_table[index] = NULL;
+                clear_bit(IREQ_ACTIVE, &sci_req_to_ireq(request)->flags);
                 return SCI_SUCCESS;
         default:
                 dev_warn(scic_to_dev(scic), "invalid state to complete I/O");
@@ -2915,7 +2922,7 @@ enum sci_status scic_controller_continue_io(struct scic_sds_request *sci_req)