isci: cleanup request allocation

Rather than return an error code and update a pointer that was passed by
reference just return the request object directly (or null if allocation
failed).

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

3 files changed, 121 insertions, 223 deletions

diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 9d7531ad9a74..f0813d076c50 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -3510,172 +3510,110 @@ static enum sci_status isci_io_request_build(
         return SCI_SUCCESS;
 }
 
-/**
- * isci_request_alloc_core() - This function gets the request object from the
- *    isci_host dma cache.
- * @isci_host: This parameter specifies the ISCI host object
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @isci_device: This parameter is the pointer to the isci remote device object
- *    that is the destination for this request.
- * @gfp_flags: This parameter specifies the os allocation flags.
- *
- * SCI_SUCCESS on successfull completion, or specific failure code.
- */
-static int isci_request_alloc_core(
-        struct isci_host *isci_host,
-        struct isci_request **isci_request,
-        struct isci_remote_device *isci_device,
-        gfp_t gfp_flags)
+static struct isci_request *isci_request_alloc_core(struct isci_host *ihost,
+                                                    struct isci_remote_device *idev,
+                                                    gfp_t gfp_flags)
 {
-        int ret = 0;
         dma_addr_t handle;
-        struct isci_request *request;
-
+        struct isci_request *ireq;
 
-        /* get pointer to dma memory. This actually points
-         * to both the isci_remote_device object and the
-         * sci object. The isci object is at the beginning
-         * of the memory allocated here.
-         */
-        request = dma_pool_alloc(isci_host->dma_pool, gfp_flags, &handle);
-        if (!request) {
-                dev_warn(&isci_host->pdev->dev,
+        ireq = dma_pool_alloc(ihost->dma_pool, gfp_flags, &handle);
+        if (!ireq) {
+                dev_warn(&ihost->pdev->dev,
                          "%s: dma_pool_alloc returned NULL\n", __func__);
-                return -ENOMEM;
+                return NULL;
         }
 
         /* initialize the request object.       */
-        spin_lock_init(&request->state_lock);
-        request->request_daddr = handle;
-        request->isci_host = isci_host;
-        request->isci_device = isci_device;
-        request->io_request_completion = NULL;
-        request->terminated = false;
+        spin_lock_init(&ireq->state_lock);
+        ireq->request_daddr = handle;
+        ireq->isci_host = ihost;
+        ireq->isci_device = idev;
+        ireq->io_request_completion = NULL;
+        ireq->terminated = false;
 
-        request->num_sg_entries = 0;
+        ireq->num_sg_entries = 0;
 
-        request->complete_in_target = false;
+        ireq->complete_in_target = false;
 
-        INIT_LIST_HEAD(&request->completed_node);
-        INIT_LIST_HEAD(&request->dev_node);
+        INIT_LIST_HEAD(&ireq->completed_node);
+        INIT_LIST_HEAD(&ireq->dev_node);
 
-        *isci_request = request;
-        isci_request_change_state(request, allocated);
+        isci_request_change_state(ireq, allocated);
 
-        return ret;
+        return ireq;
 }
 
-static int isci_request_alloc_io(
-        struct isci_host *isci_host,
-        struct sas_task *task,
-        struct isci_request **isci_request,
-        struct isci_remote_device *isci_device,
-        gfp_t gfp_flags)
+static struct isci_request *isci_request_alloc_io(struct isci_host *ihost,
+                                                  struct sas_task *task,
+                                                  struct isci_remote_device *idev,
+                                                  gfp_t gfp_flags)
 {
-        int retval = isci_request_alloc_core(isci_host, isci_request,
-                                             isci_device, gfp_flags);
-
-        if (!retval) {
-                (*isci_request)->ttype_ptr.io_task_ptr = task;
-                (*isci_request)->ttype                 = io_task;
+        struct isci_request *ireq;
 
-                task->lldd_task = *isci_request;
+        ireq = isci_request_alloc_core(ihost, idev, gfp_flags);
+        if (ireq) {
+                ireq->ttype_ptr.io_task_ptr = task;
+                ireq->ttype = io_task;
+                task->lldd_task = ireq;
         }
-        return retval;
+        return ireq;
 }
 
-/**
- * isci_request_alloc_tmf() - This function gets the request object from the
- *    isci_host dma cache and initializes the relevant fields as a sas_task.
- * @isci_host: This parameter specifies the ISCI host object
- * @sas_task: This parameter is the task struct from the upper layer driver.
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @isci_device: This parameter is the pointer to the isci remote device object
- *    that is the destination for this request.
- * @gfp_flags: This parameter specifies the os allocation flags.
- *
- * SCI_SUCCESS on successfull completion, or specific failure code.
- */
-int isci_request_alloc_tmf(
-        struct isci_host *isci_host,
-        struct isci_tmf *isci_tmf,
-        struct isci_request **isci_request,
-        struct isci_remote_device *isci_device,
-        gfp_t gfp_flags)
+struct isci_request *isci_request_alloc_tmf(struct isci_host *ihost,
+                                            struct isci_tmf *isci_tmf,
+                                            struct isci_remote_device *idev,
+                                            gfp_t gfp_flags)
 {
-        int retval = isci_request_alloc_core(isci_host, isci_request,
-                                             isci_device, gfp_flags);
-
-        if (!retval) {
+        struct isci_request *ireq;
 
-                (*isci_request)->ttype_ptr.tmf_task_ptr = isci_tmf;
-                (*isci_request)->ttype = tmf_task;
+        ireq = isci_request_alloc_core(ihost, idev, gfp_flags);
+        if (ireq) {
+                ireq->ttype_ptr.tmf_task_ptr = isci_tmf;
+                ireq->ttype = tmf_task;
         }
-        return retval;
+        return ireq;
 }
 
-/**
- * isci_request_execute() - This function allocates the isci_request object,
- *    all fills in some common fields.
- * @isci_host: This parameter specifies the ISCI host object
- * @sas_task: This parameter is the task struct from the upper layer driver.
- * @isci_request: This parameter will contain the pointer to the new
- *    isci_request object.
- * @gfp_flags: This parameter specifies the os allocation flags.
- *
- * SCI_SUCCESS on successfull completion, or specific failure code.
- */
-int isci_request_execute(
-        struct isci_host *isci_host,
-        struct sas_task *task,
-        struct isci_request **isci_request,
-        gfp_t gfp_flags)
+int isci_request_execute(struct isci_host *ihost, struct sas_task *task,
+                         gfp_t gfp_flags)
 {
-        int ret = 0;
-        struct scic_sds_remote_device *sci_device;
         enum sci_status status = SCI_FAILURE_UNSUPPORTED_PROTOCOL;
-        struct isci_remote_device *isci_device;
-        struct isci_request *request;
+        struct scic_sds_remote_device *sci_dev;
+        struct isci_remote_device *idev;
+        struct isci_request *ireq;
         unsigned long flags;
+        int ret = 0;
 
-        isci_device = task->dev->lldd_dev;
-        sci_device = &isci_device->sci;
+        idev = task->dev->lldd_dev;
+        sci_dev = &idev->sci;
 
         /* do common allocation and init of request object. */
-        ret = isci_request_alloc_io(
-                isci_host,
-                task,
-                &request,
-                isci_device,
-                gfp_flags
-                );
-
-        if (ret)
+        ireq = isci_request_alloc_io(ihost, task, idev, gfp_flags);
+        if (!ireq)
                 goto out;
 
-        status = isci_io_request_build(isci_host, request, isci_device);
+        status = isci_io_request_build(ihost, ireq, idev);
         if (status != SCI_SUCCESS) {
-                dev_warn(&isci_host->pdev->dev,
+                dev_warn(&ihost->pdev->dev,
                          "%s: request_construct failed - status = 0x%x\n",
                          __func__,
                          status);
                 goto out;
         }
 
-        spin_lock_irqsave(&isci_host->scic_lock, flags);
+        spin_lock_irqsave(&ihost->scic_lock, flags);
 
         /* send the request, let the core assign the IO TAG.    */
-        status = scic_controller_start_io(&isci_host->sci, sci_device,
-                                          &request->sci,
+        status = scic_controller_start_io(&ihost->sci, sci_dev,
+                                          &ireq->sci,
                                           SCI_CONTROLLER_INVALID_IO_TAG);
         if (status != SCI_SUCCESS &&
             status != SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
-                dev_warn(&isci_host->pdev->dev,
+                dev_warn(&ihost->pdev->dev,
                          "%s: failed request start (0x%x)\n",
                          __func__, status);
-                spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+                spin_unlock_irqrestore(&ihost->scic_lock, flags);
                 goto out;
         }
 
@@ -3687,21 +3625,21 @@ int isci_request_execute(
          * Update it's status and add it to the list in the
          * remote device object.
          */
-        list_add(&request->dev_node, &isci_device->reqs_in_process);
+        list_add(&ireq->dev_node, &idev->reqs_in_process);
 
         if (status == SCI_SUCCESS) {
                 /* Save the tag for possible task mgmt later. */
-                request->io_tag = request->sci.io_tag;
-                isci_request_change_state(request, started);
+                ireq->io_tag = ireq->sci.io_tag;
+                isci_request_change_state(ireq, started);
         } else {
                 /* The request did not really start in the
                  * hardware, so clear the request handle
                  * here so no terminations will be done.
                  */
-                request->terminated = true;
-                isci_request_change_state(request, completed);
+                ireq->terminated = true;
+                isci_request_change_state(ireq, completed);
         }
-        spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
         if (status ==
             SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
@@ -3716,7 +3654,7 @@ int isci_request_execute(
                 /* Cause this task to be scheduled in the SCSI error
                 * handler thread.
                 */
-                isci_execpath_callback(isci_host, task,
+                isci_execpath_callback(ihost, task,
                                        sas_task_abort);
 
                 /* Change the status, since we are holding
@@ -3729,11 +3667,10 @@ int isci_request_execute(
  out:
         if (status != SCI_SUCCESS) {
                 /* release dma memory on failure. */
-                isci_request_free(isci_host, request);
-                request = NULL;
+                isci_request_free(ihost, ireq);
+                ireq = NULL;
                 ret = SCI_FAILURE;
         }
 
-        *isci_request = request;
         return ret;
 }
diff --git a/drivers/scsi/isci/request.h b/drivers/scsi/isci/request.h
index ac9368c5a6b5..8de2542f081f 100644
--- a/drivers/scsi/isci/request.h
+++ b/drivers/scsi/isci/request.h
@@ -679,16 +679,13 @@ static inline void isci_request_free(struct isci_host *isci_host,
 
 #define isci_request_access_tmf(req) ((req)->ttype_ptr.tmf_task_ptr)
 
-int isci_request_alloc_tmf(struct isci_host *isci_host,
-                           struct isci_tmf *isci_tmf,
-                           struct isci_request **isci_request,
-                           struct isci_remote_device *isci_device,
-                           gfp_t gfp_flags);
-
+struct isci_request *isci_request_alloc_tmf(struct isci_host *ihost,
+                                            struct isci_tmf *isci_tmf,
+                                            struct isci_remote_device *idev,
+                                            gfp_t gfp_flags);
 
 int isci_request_execute(struct isci_host *isci_host,
                          struct sas_task *task,
-                         struct isci_request **request,
                          gfp_t gfp_flags);
 
 /**
diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
index 01032dc2c116..ded81cd1a781 100644
--- a/drivers/scsi/isci/task.c
+++ b/drivers/scsi/isci/task.c
@@ -146,7 +146,6 @@ static void isci_task_refuse(struct isci_host *ihost, struct sas_task *task,
 int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
 {
         struct isci_host *ihost = dev_to_ihost(task->dev);
-        struct isci_request *request = NULL;
         struct isci_remote_device *device;
         unsigned long flags;
         int ret;
@@ -226,8 +225,7 @@ int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
                                 spin_unlock_irqrestore(&task->task_state_lock, flags);
 
                                 /* build and send the request. */
-                                status = isci_request_execute(ihost, task, &request,
-                                                              gfp_flags);
+                                status = isci_request_execute(ihost, task, gfp_flags);
 
                                 if (status != SCI_SUCCESS) {
 
@@ -254,54 +252,34 @@ int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
         return 0;
 }
 
-
-
-/**
- * isci_task_request_build() - This function builds the task request object.
- * @isci_host: This parameter specifies the ISCI host object
- * @request: This parameter points to the isci_request object allocated in the
- *    request construct function.
- * @tmf: This parameter is the task management struct to be built
- *
- * SCI_SUCCESS on successfull completion, or specific failure code.
- */
-static enum sci_status isci_task_request_build(
-        struct isci_host *isci_host,
-        struct isci_request **isci_request,
-        struct isci_tmf *isci_tmf)
+static struct isci_request *isci_task_request_build(struct isci_host *ihost,
+                                                    struct isci_tmf *isci_tmf)
 {
-        struct scic_sds_remote_device *sci_device;
+        struct scic_sds_remote_device *sci_dev;
         enum sci_status status = SCI_FAILURE;
-        struct isci_request *request = NULL;
-        struct isci_remote_device *isci_device;
+        struct isci_request *ireq = NULL;
+        struct isci_remote_device *idev;
         struct domain_device *dev;
 
-        dev_dbg(&isci_host->pdev->dev,
+        dev_dbg(&ihost->pdev->dev,
                 "%s: isci_tmf = %p\n", __func__, isci_tmf);
 
-        isci_device = isci_tmf->device;
-        sci_device = &isci_device->sci;
-        dev = isci_device->domain_dev;
+        idev = isci_tmf->device;
+        sci_dev = &idev->sci;
+        dev = idev->domain_dev;
 
         /* do common allocation and init of request object. */
-        status = isci_request_alloc_tmf(
-                isci_host,
-                isci_tmf,
-                &request,
-                isci_device,
-                GFP_ATOMIC
-                );
-
-        if (status != SCI_SUCCESS)
-                goto out;
+        ireq = isci_request_alloc_tmf(ihost, isci_tmf, idev, GFP_ATOMIC);
+        if (!ireq)
+                return NULL;
 
         /* let the core do it's construct. */
-        status = scic_task_request_construct(&isci_host->sci, sci_device,
+        status = scic_task_request_construct(&ihost->sci, sci_dev,
                                              SCI_CONTROLLER_INVALID_IO_TAG,
-                                             &request->sci);
+                                             &ireq->sci);
 
         if (status != SCI_SUCCESS) {
-                dev_warn(&isci_host->pdev->dev,
+                dev_warn(&ihost->pdev->dev,
                          "%s: scic_task_request_construct failed - "
                          "status = 0x%x\n",
                          __func__,
@@ -312,30 +290,23 @@ static enum sci_status isci_task_request_build(
         /* XXX convert to get this from task->tproto like other drivers */
         if (dev->dev_type == SAS_END_DEV) {
                 isci_tmf->proto = SAS_PROTOCOL_SSP;
-                status = scic_task_request_construct_ssp(&request->sci);
+                status = scic_task_request_construct_ssp(&ireq->sci);
                 if (status != SCI_SUCCESS)
                         goto errout;
         }
 
         if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP)) {
                 isci_tmf->proto = SAS_PROTOCOL_SATA;
-                status = isci_sata_management_task_request_build(request);
+                status = isci_sata_management_task_request_build(ireq);
 
                 if (status != SCI_SUCCESS)
                         goto errout;
         }
-
-        goto out;
-
+        return ireq;
  errout:
-
-        /* release the dma memory if we fail. */
-        isci_request_free(isci_host, request);
-        request = NULL;
-
- out:
-        *isci_request = request;
-        return status;
+        isci_request_free(ihost, ireq);
+        ireq = NULL;
+        return ireq;
 }
 
 /**
@@ -350,16 +321,14 @@ static enum sci_status isci_task_request_build(
  * TMF_RESP_FUNC_COMPLETE on successful completion of the TMF (this includes
  * error conditions reported in the IU status), or TMF_RESP_FUNC_FAILED.
  */
-int isci_task_execute_tmf(
-        struct isci_host *isci_host,
-        struct isci_tmf *tmf,
-        unsigned long timeout_ms)
+int isci_task_execute_tmf(struct isci_host *ihost, struct isci_tmf *tmf,
+                          unsigned long timeout_ms)
 {
         DECLARE_COMPLETION_ONSTACK(completion);
         enum sci_task_status status = SCI_TASK_FAILURE;
         struct scic_sds_remote_device *sci_device;
         struct isci_remote_device *isci_device = tmf->device;
-        struct isci_request *request;
+        struct isci_request *ireq;
         int ret = TMF_RESP_FUNC_FAILED;
         unsigned long flags;
         unsigned long timeleft;
@@ -368,13 +337,13 @@ int isci_task_execute_tmf(
          * if the device is not there and ready.
          */
         if (!isci_device || isci_device->status != isci_ready_for_io) {
-                dev_dbg(&isci_host->pdev->dev,
+                dev_dbg(&ihost->pdev->dev,
                         "%s: isci_device = %p not ready (%d)\n",
                         __func__,
                         isci_device, isci_device->status);
                 return TMF_RESP_FUNC_FAILED;
         } else
-                dev_dbg(&isci_host->pdev->dev,
+                dev_dbg(&ihost->pdev->dev,
                         "%s: isci_device = %p\n",
                         __func__, isci_device);
 
@@ -383,64 +352,59 @@ int isci_task_execute_tmf(
         /* Assign the pointer to the TMF's completion kernel wait structure. */
         tmf->complete = &completion;
 
-        isci_task_request_build(
-                isci_host,
-                &request,
-                tmf
-                );
-
-        if (!request) {
-                dev_warn(&isci_host->pdev->dev,
+        ireq = isci_task_request_build(ihost, tmf);
+        if (!ireq) {
+                dev_warn(&ihost->pdev->dev,
                         "%s: isci_task_request_build failed\n",
                         __func__);
                 return TMF_RESP_FUNC_FAILED;
         }
 
-        spin_lock_irqsave(&isci_host->scic_lock, flags);
+        spin_lock_irqsave(&ihost->scic_lock, flags);
 
         /* start the TMF io. */
         status = scic_controller_start_task(
-                &isci_host->sci,
+                &ihost->sci,
                 sci_device,
-                &request->sci,
+                &ireq->sci,
                 SCI_CONTROLLER_INVALID_IO_TAG);
 
         if (status != SCI_TASK_SUCCESS) {
-                dev_warn(&isci_host->pdev->dev,
+                dev_warn(&ihost->pdev->dev,
                          "%s: start_io failed - status = 0x%x, request = %p\n",
                          __func__,
                          status,
-                         request);
-                spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+                         ireq);
+                spin_unlock_irqrestore(&ihost->scic_lock, flags);
                 goto cleanup_request;
         }
 
         if (tmf->cb_state_func != NULL)
                 tmf->cb_state_func(isci_tmf_started, tmf, tmf->cb_data);
 
-        isci_request_change_state(request, started);
+        isci_request_change_state(ireq, started);
 
         /* add the request to the remote device request list. */
-        list_add(&request->dev_node, &isci_device->reqs_in_process);
+        list_add(&ireq->dev_node, &isci_device->reqs_in_process);
 
-        spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
         /* Wait for the TMF to complete, or a timeout. */
         timeleft = wait_for_completion_timeout(&completion,
                                        jiffies + msecs_to_jiffies(timeout_ms));
 
         if (timeleft == 0) {
-                spin_lock_irqsave(&isci_host->scic_lock, flags);
+                spin_lock_irqsave(&ihost->scic_lock, flags);
 
                 if (tmf->cb_state_func != NULL)
                         tmf->cb_state_func(isci_tmf_timed_out, tmf, tmf->cb_data);
 
                 status = scic_controller_terminate_request(
-                        &request->isci_host->sci,
-                        &request->isci_device->sci,
-                        &request->sci);
+                        &ireq->isci_host->sci,
+                        &ireq->isci_device->sci,
+                        &ireq->sci);
 
-                spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+                spin_unlock_irqrestore(&ihost->scic_lock, flags);
         }
 
         isci_print_tmf(tmf);
@@ -448,7 +412,7 @@ int isci_task_execute_tmf(
         if (tmf->status == SCI_SUCCESS)
                 ret =  TMF_RESP_FUNC_COMPLETE;
         else if (tmf->status == SCI_FAILURE_IO_RESPONSE_VALID) {
-                dev_dbg(&isci_host->pdev->dev,
+                dev_dbg(&ihost->pdev->dev,
                         "%s: tmf.status == "
                         "SCI_FAILURE_IO_RESPONSE_VALID\n",
                         __func__);
@@ -456,18 +420,18 @@ int isci_task_execute_tmf(
         }
         /* Else - leave the default "failed" status alone. */
 
-        dev_dbg(&isci_host->pdev->dev,
+        dev_dbg(&ihost->pdev->dev,
                 "%s: completed request = %p\n",
                 __func__,
-                request);
+                ireq);
 
-        if (request->io_request_completion != NULL) {
+        if (ireq->io_request_completion != NULL) {
                 /* A thread is waiting for this TMF to finish. */
-                complete(request->io_request_completion);
+                complete(ireq->io_request_completion);
         }
 
  cleanup_request:
-        isci_request_free(isci_host, request);
+        isci_request_free(ihost, ireq);
         return ret;
 }