From: Tariq Toukan <tariqt@mellanox.com>
Date: Wed, 17 Jan 2018 15:39:07 +0000 (+0200)
Subject: net/mlx5e: Unify slow PCI heuristic
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=0608d4dbaf4ee30a33def4c31b78bc664c80ff79;p=openwrt%2Fstaging%2Fblogic.git

net/mlx5e: Unify slow PCI heuristic

Get the link/pci speed query and logic into a single function.
Unify the heuristics and use a single PCI threshold (16G) for all.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 1d36d7569f44..46707826f27e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3902,16 +3902,20 @@ static int mlx5e_get_pci_bw(struct mlx5_core_dev *mdev, u32 *pci_bw)
 	return 0;
 }
 
-static bool cqe_compress_heuristic(u32 link_speed, u32 pci_bw)
+static bool slow_pci_heuristic(struct mlx5_core_dev *mdev)
 {
-	return (link_speed && pci_bw &&
-		(pci_bw < 40000) && (pci_bw < link_speed));
-}
+	u32 link_speed = 0;
+	u32 pci_bw = 0;
 
-static bool hw_lro_heuristic(u32 link_speed, u32 pci_bw)
-{
-	return !(link_speed && pci_bw &&
-		 (pci_bw <= 16000) && (pci_bw < link_speed));
+	mlx5e_get_max_linkspeed(mdev, &link_speed);
+	mlx5e_get_pci_bw(mdev, &pci_bw);
+	mlx5_core_dbg_once(mdev, "Max link speed = %d, PCI BW = %d\n",
+			   link_speed, pci_bw);
+
+#define MLX5E_SLOW_PCI_RATIO (2)
+
+	return link_speed && pci_bw &&
+		link_speed > MLX5E_SLOW_PCI_RATIO * pci_bw;
 }
 
 void mlx5e_set_tx_cq_mode_params(struct mlx5e_params *params, u8 cq_period_mode)
@@ -3980,17 +3984,10 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev,
 			    u16 max_channels)
 {
 	u8 cq_period_mode = 0;
-	u32 link_speed = 0;
-	u32 pci_bw = 0;
 
 	params->num_channels = max_channels;
 	params->num_tc       = 1;
 
-	mlx5e_get_max_linkspeed(mdev, &link_speed);
-	mlx5e_get_pci_bw(mdev, &pci_bw);
-	mlx5_core_dbg(mdev, "Max link speed = %d, PCI BW = %d\n",
-		      link_speed, pci_bw);
-
 	/* SQ */
 	params->log_sq_size = is_kdump_kernel() ?
 		MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE :
@@ -4000,7 +3997,7 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev,
 	params->rx_cqe_compress_def = false;
 	if (MLX5_CAP_GEN(mdev, cqe_compression) &&
 	    MLX5_CAP_GEN(mdev, vport_group_manager))
-		params->rx_cqe_compress_def = cqe_compress_heuristic(link_speed, pci_bw);
+		params->rx_cqe_compress_def = slow_pci_heuristic(mdev);
 
 	MLX5E_SET_PFLAG(params, MLX5E_PFLAG_RX_CQE_COMPRESS, params->rx_cqe_compress_def);
 
@@ -4011,7 +4008,7 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev,
 
 	/* TODO: && MLX5_CAP_ETH(mdev, lro_cap) */
 	if (params->rq_wq_type == MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ)
-		params->lro_en = hw_lro_heuristic(link_speed, pci_bw);
+		params->lro_en = !slow_pci_heuristic(mdev);
 	params->lro_timeout = mlx5e_choose_lro_timeout(mdev, MLX5E_DEFAULT_LRO_TIMEOUT);
 
 	/* CQ moderation params */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index 4e25f2b2e0bc..7d001fe6e631 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -50,6 +50,11 @@ extern uint mlx5_core_debug_mask;
 		 __func__, __LINE__, current->pid,			\
 		 ##__VA_ARGS__)
 
+#define mlx5_core_dbg_once(__dev, format, ...)				\
+	dev_dbg_once(&(__dev)->pdev->dev, "%s:%d:(pid %d): " format,	\
+		     __func__, __LINE__, current->pid,			\
+		     ##__VA_ARGS__)
+
 #define mlx5_core_dbg_mask(__dev, mask, format, ...)			\
 do {									\
 	if ((mask) & mlx5_core_debug_mask)				\