[PATCH for-next v2 12/18] RDMA/rxe: Remove __rxe_do_task()

[Bob Pearson <rpearsonhpe@gmail.com>]

The subroutine __rxe_do_task is not thread safe. It is only
used in the rxe_qp_reset() and rxe_qp_do_cleanup() routines.
After changes in error handling in the tasklet functions the
queues can be drained by calling them once outside of the
tasklet code. This allows __rxe_do_task() to be removed.

Signed-off-by: Ian Ziemba <ian.ziemba@hpe.com>
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_qp.c   | 60 ++++++++++++++--------------
 drivers/infiniband/sw/rxe/rxe_task.c | 13 ------
 drivers/infiniband/sw/rxe/rxe_task.h |  6 ---
 3 files changed, 29 insertions(+), 50 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
index 3691eb97c576..50f6b8b8ad9d 100644
--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -477,28 +477,23 @@ static void rxe_qp_reset(struct rxe_qp *qp)
 {
 	/* stop tasks from running */
 	rxe_disable_task(&qp->resp.task);
-
-	/* stop request/comp */
-	if (qp->sq.queue) {
-		rxe_disable_task(&qp->comp.task);
-		rxe_disable_task(&qp->req.task);
-	}
+	rxe_disable_task(&qp->comp.task);
+	rxe_disable_task(&qp->req.task);
 
 	/* move qp to the reset state */
 	qp->req.state = QP_STATE_RESET;
 	qp->comp.state = QP_STATE_RESET;
 	qp->resp.state = QP_STATE_RESET;
 
-	/* let state machines reset themselves drain work and packet queues
-	 * etc.
-	 */
-	__rxe_do_task(&qp->resp.task);
+	/* drain work and packet queues */
+	rxe_responder(qp);
+	rxe_completer(qp);
+	rxe_requester(qp);
 
-	if (qp->sq.queue) {
-		__rxe_do_task(&qp->comp.task);
-		__rxe_do_task(&qp->req.task);
+	if (qp->rq.queue)
+		rxe_queue_reset(qp->rq.queue);
+	if (qp->sq.queue)
 		rxe_queue_reset(qp->sq.queue);
-	}
 
 	/* cleanup attributes */
 	atomic_set(&qp->ssn, 0);
@@ -521,11 +516,8 @@ static void rxe_qp_reset(struct rxe_qp *qp)
 
 	/* reenable tasks */
 	rxe_enable_task(&qp->resp.task);
-
-	if (qp->sq.queue) {
-		rxe_enable_task(&qp->comp.task);
-		rxe_enable_task(&qp->req.task);
-	}
+	rxe_enable_task(&qp->comp.task);
+	rxe_enable_task(&qp->req.task);
 }
 
 /* drain the send queue */
@@ -543,15 +535,25 @@ static void rxe_qp_drain(struct rxe_qp *qp)
 /* move the qp to the error state */
 void rxe_qp_error(struct rxe_qp *qp)
 {
+	/* stop tasks from running */
+	rxe_disable_task(&qp->resp.task);
+	rxe_disable_task(&qp->comp.task);
+	rxe_disable_task(&qp->req.task);
+
 	qp->req.state = QP_STATE_ERROR;
 	qp->resp.state = QP_STATE_ERROR;
 	qp->comp.state = QP_STATE_ERROR;
 	qp->attr.qp_state = IB_QPS_ERR;
 
 	/* drain work and packet queues */
-	rxe_sched_task(&qp->resp.task);
-	rxe_sched_task(&qp->comp.task);
-	rxe_sched_task(&qp->req.task);
+	rxe_responder(qp);
+	rxe_completer(qp);
+	rxe_requester(qp);
+
+	/* reenable tasks */
+	rxe_enable_task(&qp->resp.task);
+	rxe_enable_task(&qp->comp.task);
+	rxe_enable_task(&qp->req.task);
 }
 
 /* called by the modify qp verb */
@@ -770,24 +772,20 @@ static void rxe_qp_do_cleanup(struct work_struct *work)
 
 	qp->valid = 0;
 	qp->qp_timeout_jiffies = 0;
-	rxe_cleanup_task(&qp->resp.task);
 
 	if (qp_type(qp) == IB_QPT_RC) {
 		del_timer_sync(&qp->retrans_timer);
 		del_timer_sync(&qp->rnr_nak_timer);
 	}
 
+	rxe_cleanup_task(&qp->resp.task);
 	rxe_cleanup_task(&qp->req.task);
 	rxe_cleanup_task(&qp->comp.task);
 
-	/* flush out any receive wr's or pending requests */
-	if (qp->req.task.func)
-		__rxe_do_task(&qp->req.task);
-
-	if (qp->sq.queue) {
-		__rxe_do_task(&qp->comp.task);
-		__rxe_do_task(&qp->req.task);
-	}
+	/* drain any receive wr's or pending requests */
+	rxe_responder(qp);
+	rxe_completer(qp);
+	rxe_requester(qp);
 
 	if (qp->sq.queue)
 		rxe_queue_cleanup(qp->sq.queue);
diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c
index 8dfbfa164eff..120693c9a795 100644
--- a/drivers/infiniband/sw/rxe/rxe_task.c
+++ b/drivers/infiniband/sw/rxe/rxe_task.c
@@ -6,19 +6,6 @@
 
 #include "rxe.h"
 
-int __rxe_do_task(struct rxe_task *task)
-
-{
-	int ret;
-
-	while ((ret = task->func(task->arg)) == 0)
-		;
-
-	task->ret = ret;
-
-	return ret;
-}
-
 /*
  * this locking is due to a potential race where
  * a second caller finds the task already running
diff --git a/drivers/infiniband/sw/rxe/rxe_task.h b/drivers/infiniband/sw/rxe/rxe_task.h
index 31963129ff7a..d594468fcf56 100644
--- a/drivers/infiniband/sw/rxe/rxe_task.h
+++ b/drivers/infiniband/sw/rxe/rxe_task.h
@@ -48,12 +48,6 @@ struct rxe_task {
 int rxe_init_task(struct rxe_task *task, void *arg, int (*func)(void *),
 		  enum rxe_task_type type);
 
-/*
- * raw call to func in loop without any checking
- * can call when tasklets are disabled
- */
-int __rxe_do_task(struct rxe_task *task);
-
 void rxe_run_task(struct rxe_task *task);
 
 void rxe_sched_task(struct rxe_task *task);
-- 
2.34.1