scsi: isci: Drop SAS_TASK_AT_INITIATOR check in isci_task_abort_task()

In the queue path, move around when we assign sas_task->lldd_task such that
this pointer and the SAS_TASK_AT_INITIATOR flag are set atomically.  It is
also not required to clear SAS_TASK_AT_INITIATOR in isci_task_execute_task()
error path as it is also cleared immediately after in isci_task_refuse()
call.

Now the following items may be considered:

 - SAS_TASK_STATE_DONE and SAS_TASK_AT_INITIATOR are mutually exclusive
   apart from possibly when SAS_TASK_STATE_DONE is set in
   sas_scsi_find_task(), but that is after .lldd_abort_task, i.e. the
   considered callback, is called.

 - If isci_task_refuse() is called in the queue path, then
   sas_task->lldd_task and SAS_TASK_AT_INITIATOR are cleared atomically in
   isci_task_refuse().

 - In the completion path, SAS_TASK_STATE_DONE is set and
   SAS_TASK_AT_INITIATOR is cleared atomically before the
   sas_task.lldd_task is cleared later.

So in isci_task_abort_task() if SAS_TASK_STATE_DONE is not set and
sas_task.lldd_task is still set, then SAS_TASK_AT_INITIATOR must be set -
so we can drop this check on SAS_TASK_AT_INITIATOR.

[mkp: checkpatch]

Link: https://lore.kernel.org/r/1644489804-85730-2-git-send-email-john.garry@huawei.com
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 4 insertions, 8 deletions

diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index fcaa84a3c210..ad63704b660e 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -3406,9 +3406,9 @@ static struct isci_request *isci_request_from_tag(struct isci_host *ihost, u16 t
 	return ireq;
 }
 
-static struct isci_request *isci_io_request_from_tag(struct isci_host *ihost,
-						     struct sas_task *task,
-						     u16 tag)
+struct isci_request *isci_io_request_from_tag(struct isci_host *ihost,
+					      struct sas_task *task,
+					      u16 tag)
 {
 	struct isci_request *ireq;
 
@@ -3434,16 +3434,12 @@ struct isci_request *isci_tmf_request_from_tag(struct isci_host *ihost,
 }
 
 int isci_request_execute(struct isci_host *ihost, struct isci_remote_device *idev,
-			 struct sas_task *task, u16 tag)
+			 struct sas_task *task, struct isci_request *ireq)
 {
 	enum sci_status status;
-	struct isci_request *ireq;
 	unsigned long flags;
 	int ret = 0;
 
-	/* do common allocation and init of request object. */
-	ireq = isci_io_request_from_tag(ihost, task, tag);
-
 	status = isci_io_request_build(ihost, ireq, idev);
 	if (status != SCI_SUCCESS) {
 		dev_dbg(&ihost->pdev->dev,