sfc: introduce shutdown entry point in efx pci driver

Make the device inactive when the system shutdown callback has been
invoked. This is achieved by freezing the driver and disabling the
PCI bus mastering.
Co-developed-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://lore.kernel.org/r/20220906105620.26179-1-pieter.jansen-van-vuuren@amd.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/sfc/efx.c

@@ -1175,6 +1175,17 @@ static int efx_pm_freeze(struct device *dev)
 	return 0;
 }
 
+static void efx_pci_shutdown(struct pci_dev *pci_dev)
+{
+	struct efx_nic *efx = pci_get_drvdata(pci_dev);
+
+	if (!efx)
+		return;
+
+	efx_pm_freeze(&pci_dev->dev);
+	pci_disable_device(pci_dev);
+}
+
 static int efx_pm_thaw(struct device *dev)
 {
 	int rc;
@@ -1279,6 +1290,7 @@ static struct pci_driver efx_pci_driver = {
 	.probe		= efx_pci_probe,
 	.remove		= efx_pci_remove,
 	.driver.pm	= &efx_pm_ops,
+	.shutdown	= efx_pci_shutdown,
 	.err_handler	= &efx_err_handlers,
 #ifdef CONFIG_SFC_SRIOV
 	.sriov_configure = efx_pci_sriov_configure,

drivers/net/ethernet/sfc/siena/efx.c

@@ -1148,6 +1148,17 @@ static int efx_pm_freeze(struct device *dev)
 	return 0;
 }
 
+static void efx_pci_shutdown(struct pci_dev *pci_dev)
+{
+	struct efx_nic *efx = pci_get_drvdata(pci_dev);
+
+	if (!efx)
+		return;
+
+	efx_pm_freeze(&pci_dev->dev);
+	pci_disable_device(pci_dev);
+}
+
 static int efx_pm_thaw(struct device *dev)
 {
 	int rc;
@@ -1252,6 +1263,7 @@ static struct pci_driver efx_pci_driver = {
 	.probe		= efx_pci_probe,
 	.remove		= efx_pci_remove,
 	.driver.pm	= &efx_pm_ops,
+	.shutdown	= efx_pci_shutdown,
 	.err_handler	= &efx_siena_err_handlers,
 #ifdef CONFIG_SFC_SIENA_SRIOV
 	.sriov_configure = efx_pci_sriov_configure,