net/mlx4: Use Kconfig flag to remove support of old gen2 Mellanox devices

Since Mellanox focus is on newer adapters, we would like to have the
ability to disable the support for old gen2 adapters.

This can be done by turning off the MLX4_CORE_GEN2 Kconfig flag.
We keep it turned on by default.
Signed-off-by: NSlava Shwartsman <slavash@mellanox.com>
Signed-off-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/Kconfig

@@ -38,3 +38,11 @@ config MLX4_DEBUG
 	  mlx4_core driver.  The output can be turned on via the
 	  debug_level module parameter (which can also be set after
 	  the driver is loaded through sysfs).
+
+config MLX4_CORE_GEN2
+	bool "Support for old gen2 Mellanox PCI IDs" if (MLX4_CORE)
+	depends on MLX4_CORE
+	default y
+	---help---
+	  Say Y here if you want to use old gen2 Mellanox devices in the
+	  driver.

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -4066,6 +4066,7 @@ int mlx4_restart_one(struct pci_dev *pdev)
 #define MLX_GN(id) { PCI_VDEVICE(MELLANOX, id), 0 }
 
 static const struct pci_device_id mlx4_pci_table[] = {
+#ifdef CONFIG_MLX4_CORE_GEN2
 	/* MT25408 "Hermon" */
 	MLX_SP(PCI_DEVICE_ID_MELLANOX_HERMON_SDR),	/* SDR */
 	MLX_SP(PCI_DEVICE_ID_MELLANOX_HERMON_DDR),	/* DDR */
@@ -4085,6 +4086,7 @@ static const struct pci_device_id mlx4_pci_table[] = {
 	MLX_SP(PCI_DEVICE_ID_MELLANOX_CONNECTX2),
 	/* MT25400 Family [ConnectX-2] */
 	MLX_VF(0x1002),					/* Virtual Function */
+#endif /* CONFIG_MLX4_CORE_GEN2 */
 	/* MT27500 Family [ConnectX-3] */
 	MLX_GN(PCI_DEVICE_ID_MELLANOX_CONNECTX3),
 	MLX_VF(0x1004),					/* Virtual Function */