net/mlx5: FWTrace, Use async events chain

Remove the explicit call to mlx5_fw_tracer_event on
MLX5_EVENT_TYPE_DEVICE_TRACER and let fw tracer to register
its own handler when its ready.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c

@@ -30,6 +30,7 @@
  * SOFTWARE.
  */
 #define CREATE_TRACE_POINTS
+#include "lib/eq.h"
 #include "fw_tracer.h"
 #include "fw_tracer_tracepoint.h"
 
@@ -846,9 +847,9 @@ struct mlx5_fw_tracer *mlx5_fw_tracer_create(struct mlx5_core_dev *dev)
 	return ERR_PTR(err);
 }
 
-/* Create HW resources + start tracer
- * must be called before Async EQ is created
- */
+static int fw_tracer_event(struct notifier_block *nb, unsigned long action, void *data);
+
+/* Create HW resources + start tracer */
 int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer)
 {
 	struct mlx5_core_dev *dev;
@@ -874,6 +875,9 @@ int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer)
 		goto err_dealloc_pd;
 	}
 
+	MLX5_NB_INIT(&tracer->nb, fw_tracer_event, DEVICE_TRACER);
+	mlx5_eq_notifier_register(dev, &tracer->nb);
+
 	mlx5_fw_tracer_start(tracer);
 
 	return 0;
@@ -883,9 +887,7 @@ int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer)
 	return err;
 }
 
-/* Stop tracer + Cleanup HW resources
- * must be called after Async EQ is destroyed
- */
+/* Stop tracer + Cleanup HW resources */
 void mlx5_fw_tracer_cleanup(struct mlx5_fw_tracer *tracer)
 {
 	if (IS_ERR_OR_NULL(tracer))
@@ -893,7 +895,7 @@ void mlx5_fw_tracer_cleanup(struct mlx5_fw_tracer *tracer)
 
 	mlx5_core_dbg(tracer->dev, "FWTracer: Cleanup, is owner ? (%d)\n",
 		      tracer->owner);
-
+	mlx5_eq_notifier_unregister(tracer->dev, &tracer->nb);
 	cancel_work_sync(&tracer->ownership_change_work);
 	cancel_work_sync(&tracer->handle_traces_work);
 
@@ -922,12 +924,11 @@ void mlx5_fw_tracer_destroy(struct mlx5_fw_tracer *tracer)
 	kfree(tracer);
 }
 
-void mlx5_fw_tracer_event(struct mlx5_core_dev *dev, struct mlx5_eqe *eqe)
+static int fw_tracer_event(struct notifier_block *nb, unsigned long action, void *data)
 {
-	struct mlx5_fw_tracer *tracer = dev->tracer;
-
-	if (!tracer)
-		return;
+	struct mlx5_fw_tracer *tracer = mlx5_nb_cof(nb, struct mlx5_fw_tracer, nb);
+	struct mlx5_core_dev *dev = tracer->dev;
+	struct mlx5_eqe *eqe = data;
 
 	switch (eqe->sub_type) {
 	case MLX5_TRACER_SUBTYPE_OWNERSHIP_CHANGE:
@@ -942,6 +943,8 @@ void mlx5_fw_tracer_event(struct mlx5_core_dev *dev, struct mlx5_eqe *eqe)
 		mlx5_core_dbg(dev, "FWTracer: Event with unrecognized subtype: sub_type %d\n",
 			      eqe->sub_type);
 	}
+
+	return NOTIFY_OK;
 }
 
 EXPORT_TRACEPOINT_SYMBOL(mlx5_fw);

drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.h

@@ -55,6 +55,7 @@
 
 struct mlx5_fw_tracer {
 	struct mlx5_core_dev *dev;
+	struct mlx5_nb        nb;
 	bool owner;
 	u8   trc_ver;
 	struct workqueue_struct *work_queue;
@@ -170,6 +171,5 @@ struct mlx5_fw_tracer *mlx5_fw_tracer_create(struct mlx5_core_dev *dev);
 int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer);
 void mlx5_fw_tracer_cleanup(struct mlx5_fw_tracer *tracer);
 void mlx5_fw_tracer_destroy(struct mlx5_fw_tracer *tracer);
-void mlx5_fw_tracer_event(struct mlx5_core_dev *dev, struct mlx5_eqe *eqe);
 
 #endif

drivers/net/ethernet/mellanox/mlx5/core/eq.c

@@ -434,10 +434,6 @@ static irqreturn_t mlx5_eq_async_int(int irq, void *eq_ptr)
 			general_event_handler(dev, eqe);
 			break;
 
-		case MLX5_EVENT_TYPE_DEVICE_TRACER:
-			mlx5_fw_tracer_event(dev, eqe);
-			break;
-
 		default:
 			mlx5_core_warn(dev, "Unhandled event 0x%x on EQ 0x%x\n",
 				       eqe->type, eq->eqn);