[PATCH for-next v2 17/18] RDMA/rxe: Add workqueue support for tasks

[Bob Pearson <rpearsonhpe@gmail.com>]

Add a third task type RXE_TASK_TYPE_WORKQUEUE to rxe_task.c.

Signed-off-by: Ian Ziemba <ian.ziemba@hpe.com>
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe.c      |  9 +++-
 drivers/infiniband/sw/rxe/rxe_task.c | 69 ++++++++++++++++++++++++++++
 drivers/infiniband/sw/rxe/rxe_task.h | 10 +++-
 3 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
index 51daac5c4feb..6d80218334ca 100644
--- a/drivers/infiniband/sw/rxe/rxe.c
+++ b/drivers/infiniband/sw/rxe/rxe.c
@@ -210,10 +210,16 @@ static int __init rxe_module_init(void)
 {
 	int err;
 
-	err = rxe_net_init();
+	err = rxe_alloc_wq();
 	if (err)
 		return err;
 
+	err = rxe_net_init();
+	if (err) {
+		rxe_destroy_wq();
+		return err;
+	}
+
 	rdma_link_register(&rxe_link_ops);
 	pr_info("loaded\n");
 	return 0;
@@ -224,6 +230,7 @@ static void __exit rxe_module_exit(void)
 	rdma_link_unregister(&rxe_link_ops);
 	ib_unregister_driver(RDMA_DRIVER_RXE);
 	rxe_net_exit();
+	rxe_destroy_wq();
 
 	pr_info("unloaded\n");
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c
index da175f2a0dbf..9b8c9d28ee46 100644
--- a/drivers/infiniband/sw/rxe/rxe_task.c
+++ b/drivers/infiniband/sw/rxe/rxe_task.c
@@ -6,6 +6,22 @@
 
 #include "rxe.h"
 
+static struct workqueue_struct *rxe_wq;
+
+int rxe_alloc_wq(void)
+{
+	rxe_wq = alloc_workqueue("rxe_wq", WQ_CPU_INTENSIVE, WQ_MAX_ACTIVE);
+	if (!rxe_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void rxe_destroy_wq(void)
+{
+	destroy_workqueue(rxe_wq);
+}
+
 static bool task_is_idle(struct rxe_task *task)
 {
 	spin_lock_bh(&task->lock);
@@ -198,6 +217,53 @@ static void tsklet_init(struct rxe_task *task)
 	task->ops = &tsklet_ops;
 }
 
+static void work_sched(struct rxe_task *task)
+{
+	if (task_is_idle(task))
+		queue_work(rxe_wq, &task->work);
+}
+
+static void work_do_task(struct work_struct *work)
+{
+	do_task(container_of(work, struct rxe_task, work));
+}
+
+static void work_run(struct rxe_task *task)
+{
+	if (task_is_idle(task))
+		do_task(task);
+}
+
+static void work_enable(struct rxe_task *task)
+{
+	enable_task(task);
+}
+
+static void work_disable(struct rxe_task *task)
+{
+	disable_task(task);
+	flush_workqueue(rxe_wq);
+}
+
+static void work_cleanup(struct rxe_task *task)
+{
+	cleanup_task(task);
+}
+
+static const struct rxe_task_ops work_ops = {
+	.sched = work_sched,
+	.run = work_run,
+	.enable = work_enable,
+	.disable = work_disable,
+	.cleanup = work_cleanup,
+};
+
+static void work_init(struct rxe_task *task)
+{
+	INIT_WORK(&task->work, work_do_task);
+	task->ops = &work_ops;
+}
+
 int rxe_init_task(struct rxe_task *task, void *arg, int (*func)(void *),
 		  enum rxe_task_type type)
 {
@@ -215,6 +281,9 @@ int rxe_init_task(struct rxe_task *task, void *arg, int (*func)(void *),
 	case RXE_TASK_TYPE_TASKLET:
 		tsklet_init(task);
 		break;
+	case RXE_TASK_TYPE_WORKQUEUE:
+		work_init(task);
+		break;
 	default:
 		pr_debug("%s: invalid task type = %d\n", __func__, type);
 		return -EINVAL;
diff --git a/drivers/infiniband/sw/rxe/rxe_task.h b/drivers/infiniband/sw/rxe/rxe_task.h
index 2c4ef4d339f1..d1156b935635 100644
--- a/drivers/infiniband/sw/rxe/rxe_task.h
+++ b/drivers/infiniband/sw/rxe/rxe_task.h
@@ -20,6 +20,7 @@ struct rxe_task_ops {
 enum rxe_task_type {
 	RXE_TASK_TYPE_INLINE	= 0,
 	RXE_TASK_TYPE_TASKLET	= 1,
+	RXE_TASK_TYPE_WORKQUEUE	= 2,
 };
 
 enum {
@@ -36,7 +37,10 @@ enum {
  * called again.
  */
 struct rxe_task {
-	struct tasklet_struct		tasklet;
+	union {
+		struct tasklet_struct		tasklet;
+		struct work_struct		work;
+	};
 	int				state;
 	spinlock_t			lock;
 	void				*arg;
@@ -47,6 +51,10 @@ struct rxe_task {
 	enum rxe_task_type		type;
 };
 
+int rxe_alloc_wq(void);
+
+void rxe_destroy_wq(void);
+
 int rxe_init_task(struct rxe_task *task, void *arg, int (*func)(void *),
 		  enum rxe_task_type type);
 
-- 
2.34.1