net/mlx5e: Use pcie_bandwidth_available() to compute bandwidth

Use the new pci_bandwidth_available() function to calculate maximum
available bandwidth through the PCI chain instead of computing it ourselves
with mlx5e_get_pci_bw().

This is used to detect when the device is capable of more bandwidth than is
available in the current slot.  The driver may adjust compression settings
accordingly.

Note that pci_bandwidth_available() accounts for PCIe encoding overhead, so
it is more accurate than mlx5e_get_pci_bw() was.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
[bhelgaas: remove mlx5e_get_pci_bw() wrapper altogether]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tariq Toukan <tariqt@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 47bab842c5eea8656a68002440d616c7c94c4611..93291ec4a3d1f5df660ad37a387f689beddbd5bd 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3864,36 +3864,6 @@ void mlx5e_build_default_indir_rqt(u32 *indirection_rqt, int len,
                indirection_rqt[i] = i % num_channels;
 }
 
-static int mlx5e_get_pci_bw(struct mlx5_core_dev *mdev, u32 *pci_bw)
-{
-       enum pcie_link_width width;
-       enum pci_bus_speed speed;
-       int err = 0;
-
-       err = pcie_get_minimum_link(mdev->pdev, &speed, &width);
-       if (err)
-               return err;
-
-       if (speed == PCI_SPEED_UNKNOWN || width == PCIE_LNK_WIDTH_UNKNOWN)
-               return -EINVAL;
-
-       switch (speed) {
-       case PCIE_SPEED_2_5GT:
-               *pci_bw = 2500 * width;
-               break;
-       case PCIE_SPEED_5_0GT:
-               *pci_bw = 5000 * width;
-               break;
-       case PCIE_SPEED_8_0GT:
-               *pci_bw = 8000 * width;
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
 static bool cqe_compress_heuristic(u32 link_speed, u32 pci_bw)
 {
        return (link_speed && pci_bw &&
@@ -3979,7 +3949,7 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev,
        params->num_tc       = 1;
 
        mlx5e_get_max_linkspeed(mdev, &link_speed);
-       mlx5e_get_pci_bw(mdev, &pci_bw);
+       pci_bw = pcie_bandwidth_available(mdev->pdev, NULL, NULL, NULL);
        mlx5_core_dbg(mdev, "Max link speed = %d, PCI BW = %d\n",
                      link_speed, pci_bw);