net/mlx5: Check capability for fw_reset

Functions which can't access MFRL (Management Firmware Reset Level)
register, have no use of fw_reset structures or events. Remove fw_reset
structures allocation and registration for fw reset events notifications
for these functions.

Having the devlink param enable_remote_dev_reset on functions that don't
have this capability is misleading as these functions are not allowed to
influence the reset flow. Hence, this patch removes this parameter for
such functions.

In addition, return not supported on devlink reload action fw_activate
for these functions.

Fixes: 38b9f903 ("net/mlx5: Handle sync reset request event")
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -157,6 +157,12 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 		return -EOPNOTSUPP;
 	}
 
+	if (action == DEVLINK_RELOAD_ACTION_FW_ACTIVATE &&
+	    !dev->priv.fw_reset) {
+		NL_SET_ERR_MSG_MOD(extack, "FW activate is unsupported for this function");
+		return -EOPNOTSUPP;
+	}
+
 	if (mlx5_core_is_pf(dev) && pci_num_vf(pdev))
 		NL_SET_ERR_MSG_MOD(extack, "reload while VFs are present is unfavorable");
 

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

@@ -703,19 +703,30 @@ void mlx5_fw_reset_events_start(struct mlx5_core_dev *dev)
 {
 	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
 
+	if (!fw_reset)
+		return;
+
 	MLX5_NB_INIT(&fw_reset->nb, fw_reset_event_notifier, GENERAL_EVENT);
 	mlx5_eq_notifier_register(dev, &fw_reset->nb);
 }
 
 void mlx5_fw_reset_events_stop(struct mlx5_core_dev *dev)
 {
-	mlx5_eq_notifier_unregister(dev, &dev->priv.fw_reset->nb);
+	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
+
+	if (!fw_reset)
+		return;
+
+	mlx5_eq_notifier_unregister(dev, &fw_reset->nb);
 }
 
 void mlx5_drain_fw_reset(struct mlx5_core_dev *dev)
 {
 	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
 
+	if (!fw_reset)
+		return;
+
 	set_bit(MLX5_FW_RESET_FLAGS_DROP_NEW_REQUESTS, &fw_reset->reset_flags);
 	cancel_work_sync(&fw_reset->fw_live_patch_work);
 	cancel_work_sync(&fw_reset->reset_request_work);
@@ -733,9 +744,13 @@ static const struct devlink_param mlx5_fw_reset_devlink_params[] = {
 
 int mlx5_fw_reset_init(struct mlx5_core_dev *dev)
 {
-	struct mlx5_fw_reset *fw_reset = kzalloc(sizeof(*fw_reset), GFP_KERNEL);
+	struct mlx5_fw_reset *fw_reset;
 	int err;
 
+	if (!MLX5_CAP_MCAM_REG(dev, mfrl))
+		return 0;
+
+	fw_reset = kzalloc(sizeof(*fw_reset), GFP_KERNEL);
 	if (!fw_reset)
 		return -ENOMEM;
 	fw_reset->wq = create_singlethread_workqueue("mlx5_fw_reset_events");
@@ -771,6 +786,9 @@ void mlx5_fw_reset_cleanup(struct mlx5_core_dev *dev)
 {
 	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
 
+	if (!fw_reset)
+		return;
+
 	devl_params_unregister(priv_to_devlink(dev),
 			       mlx5_fw_reset_devlink_params,
 			       ARRAY_SIZE(mlx5_fw_reset_devlink_params));

include/linux/mlx5/mlx5_ifc.h

@@ -10261,7 +10261,9 @@ struct mlx5_ifc_mcam_access_reg_bits {
 
 	u8         regs_63_to_46[0x12];
 	u8         mrtc[0x1];
-	u8         regs_44_to_32[0xd];
+	u8         regs_44_to_41[0x4];
+	u8         mfrl[0x1];
+	u8         regs_39_to_32[0x8];
 
 	u8         regs_31_to_10[0x16];
 	u8         mtmp[0x1];