net/mlx5: Fix crash upon suspend/resume

Currently a Linux system with the mlx5 NIC always crashes upon
hibernation - suspend/resume.

Add basic callbacks so the NIC could be suspended and resumed.

Fixes: 9603b61d ("mlx5: Move pci device handling from mlx5_ib to mlx5_core")
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -1549,6 +1549,22 @@ static void shutdown(struct pci_dev *pdev)
 	mlx5_pci_disable_device(dev);
 }
 
+static int mlx5_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	struct mlx5_core_dev *dev = pci_get_drvdata(pdev);
+
+	mlx5_unload_one(dev, false);
+
+	return 0;
+}
+
+static int mlx5_resume(struct pci_dev *pdev)
+{
+	struct mlx5_core_dev *dev = pci_get_drvdata(pdev);
+
+	return mlx5_load_one(dev, false);
+}
+
 static const struct pci_device_id mlx5_core_pci_table[] = {
 	{ PCI_VDEVICE(MELLANOX, PCI_DEVICE_ID_MELLANOX_CONNECTIB) },
 	{ PCI_VDEVICE(MELLANOX, 0x1012), MLX5_PCI_DEV_IS_VF},	/* Connect-IB VF */
@@ -1592,6 +1608,8 @@ static struct pci_driver mlx5_core_driver = {
 	.id_table       = mlx5_core_pci_table,
 	.probe          = init_one,
 	.remove         = remove_one,
+	.suspend        = mlx5_suspend,
+	.resume         = mlx5_resume,
 	.shutdown	= shutdown,
 	.err_handler	= &mlx5_err_handler,
 	.sriov_configure   = mlx5_core_sriov_configure,