From: Wei Zhang <weizhang@nvidia.com>
Date: Thu, 12 Oct 2023 12:27:36 -0700
Subject: net/mlx5: Parallelize vhca event handling
Patch-mainline: v6.7-rc1
Git-commit: 3f7f31fff2510272334f3d0374c432bdaa4f1536
References: jsc#PED-3311

At present, mlx5 driver have a general purpose
event handler which not only handles vhca event
but also many other events. This incurs a huge
bottleneck because the event handler is
implemented by single threaded workqueue and all
events are forced to be handled in serial manner
even though application tries to create multiple
SFs simultaneously.

Introduce a dedicated vhca event handler which
manages SFs parallel creation.

Signed-off-by: Wei Zhang <weizhang@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/events.c        |    5 -
 drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h     |    3 
 drivers/net/ethernet/mellanox/mlx5/core/sf/vhca_event.c |   57 +++++++++++++++-
 include/linux/mlx5/driver.h                             |    1 
 4 files changed, 57 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/events.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/events.c
@@ -441,8 +441,3 @@ int mlx5_blocking_notifier_call_chain(st
 
 	return blocking_notifier_call_chain(&events->sw_nh, event, data);
 }
-
-void mlx5_events_work_enqueue(struct mlx5_core_dev *dev, struct work_struct *work)
-{
-	queue_work(dev->priv.events->wq, work);
-}
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -159,6 +159,8 @@ enum mlx5_semaphore_space_address {
 
 #define MLX5_DEFAULT_PROF       2
 #define MLX5_SF_PROF		3
+#define MLX5_NUM_FW_CMD_THREADS 8
+#define MLX5_DEV_MAX_WQS	MLX5_NUM_FW_CMD_THREADS
 
 static inline int mlx5_flexible_inlen(struct mlx5_core_dev *dev, size_t fixed,
 				      size_t item_size, size_t num_items,
@@ -347,7 +349,6 @@ int mlx5_vport_set_other_func_cap(struct
 #define mlx5_vport_get_other_func_general_cap(dev, vport, out)		\
 	mlx5_vport_get_other_func_cap(dev, vport, out, MLX5_CAP_GENERAL)
 
-void mlx5_events_work_enqueue(struct mlx5_core_dev *dev, struct work_struct *work);
 static inline u32 mlx5_sriov_get_vf_total_msix(struct pci_dev *pdev)
 {
 	struct mlx5_core_dev *dev = pci_get_drvdata(pdev);
--- a/drivers/net/ethernet/mellanox/mlx5/core/sf/vhca_event.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sf/vhca_event.c
@@ -21,6 +21,15 @@ struct mlx5_vhca_event_work {
 	struct mlx5_vhca_state_event event;
 };
 
+struct mlx5_vhca_event_handler {
+	struct workqueue_struct *wq;
+};
+
+struct mlx5_vhca_events {
+	struct mlx5_core_dev *dev;
+	struct mlx5_vhca_event_handler handler[MLX5_DEV_MAX_WQS];
+};
+
 int mlx5_cmd_query_vhca_state(struct mlx5_core_dev *dev, u16 function_id, u32 *out, u32 outlen)
 {
 	u32 in[MLX5_ST_SZ_DW(query_vhca_state_in)] = {};
@@ -99,6 +108,12 @@ static void mlx5_vhca_state_work_handler
 	kfree(work);
 }
 
+static void
+mlx5_vhca_events_work_enqueue(struct mlx5_core_dev *dev, int idx, struct work_struct *work)
+{
+	queue_work(dev->priv.vhca_events->handler[idx].wq, work);
+}
+
 static int
 mlx5_vhca_state_change_notifier(struct notifier_block *nb, unsigned long type, void *data)
 {
@@ -106,6 +121,7 @@ mlx5_vhca_state_change_notifier(struct n
 				mlx5_nb_cof(nb, struct mlx5_vhca_state_notifier, nb);
 	struct mlx5_vhca_event_work *work;
 	struct mlx5_eqe *eqe = data;
+	int wq_idx;
 
 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
 	if (!work)
@@ -113,7 +129,8 @@ mlx5_vhca_state_change_notifier(struct n
 	INIT_WORK(&work->work, &mlx5_vhca_state_work_handler);
 	work->notifier = notifier;
 	work->event.function_id = be16_to_cpu(eqe->data.vhca_state.function_id);
-	mlx5_events_work_enqueue(notifier->dev, &work->work);
+	wq_idx = work->event.function_id % MLX5_DEV_MAX_WQS;
+	mlx5_vhca_events_work_enqueue(notifier->dev, wq_idx, &work->work);
 	return NOTIFY_OK;
 }
 
@@ -132,28 +149,62 @@ void mlx5_vhca_state_cap_handle(struct m
 int mlx5_vhca_event_init(struct mlx5_core_dev *dev)
 {
 	struct mlx5_vhca_state_notifier *notifier;
+	char wq_name[MLX5_CMD_WQ_MAX_NAME];
+	struct mlx5_vhca_events *events;
+	int err, i;
 
 	if (!mlx5_vhca_event_supported(dev))
 		return 0;
 
-	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
-	if (!notifier)
+	events = kzalloc(sizeof(*events), GFP_KERNEL);
+	if (!events)
 		return -ENOMEM;
 
+	events->dev = dev;
+	dev->priv.vhca_events = events;
+	for (i = 0; i < MLX5_DEV_MAX_WQS; i++) {
+		snprintf(wq_name, MLX5_CMD_WQ_MAX_NAME, "mlx5_vhca_event%d", i);
+		events->handler[i].wq = create_singlethread_workqueue(wq_name);
+		if (!events->handler[i].wq) {
+			err = -ENOMEM;
+			goto err_create_wq;
+		}
+	}
+
+	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
+	if (!notifier) {
+		err = -ENOMEM;
+		goto err_notifier;
+	}
+
 	dev->priv.vhca_state_notifier = notifier;
 	notifier->dev = dev;
 	BLOCKING_INIT_NOTIFIER_HEAD(&notifier->n_head);
 	MLX5_NB_INIT(&notifier->nb, mlx5_vhca_state_change_notifier, VHCA_STATE_CHANGE);
 	return 0;
+
+err_notifier:
+err_create_wq:
+	for (--i; i >= 0; i--)
+		destroy_workqueue(events->handler[i].wq);
+	kfree(events);
+	return err;
 }
 
 void mlx5_vhca_event_cleanup(struct mlx5_core_dev *dev)
 {
+	struct mlx5_vhca_events *vhca_events;
+	int i;
+
 	if (!mlx5_vhca_event_supported(dev))
 		return;
 
 	kfree(dev->priv.vhca_state_notifier);
 	dev->priv.vhca_state_notifier = NULL;
+	vhca_events = dev->priv.vhca_events;
+	for (i = 0; i < MLX5_DEV_MAX_WQS; i++)
+		destroy_workqueue(vhca_events->handler[i].wq);
+	kvfree(vhca_events);
 }
 
 void mlx5_vhca_event_start(struct mlx5_core_dev *dev)
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -615,6 +615,7 @@ struct mlx5_priv {
 	int			adev_idx;
 	int			sw_vhca_id;
 	struct mlx5_events      *events;
+	struct mlx5_vhca_events *vhca_events;
 
 	struct mlx5_flow_steering *steering;
 	struct mlx5_mpfs        *mpfs;