sfc: Add a PROBED state for EF100 VDPA use.

For VDPA we need to tear down the driver to the point where it
has various control channels like MCDI, but it no longer has
a network device. This adds a state corresponding to
that mode that will be used when VDPA support is added.
Signed-off-by: Jonathan Cooper <jonathan.s.cooper@amd.com>
Co-developed-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef100_netdev.c

@@ -291,7 +291,7 @@ void ef100_unregister_netdev(struct efx_nic *efx)
 {
 	if (efx_dev_registered(efx)) {
 		efx_fini_mcdi_logging(efx);
-		efx->state = STATE_UNINIT;
+		efx->state = STATE_PROBED;
 		unregister_netdev(efx->net_dev);
 	}
 }

drivers/net/ethernet/sfc/efx_common.c

@@ -1222,8 +1222,10 @@ static pci_ers_result_t efx_io_error_detected(struct pci_dev *pdev,
 
 		efx_device_detach_sync(efx);
 
-		efx_stop_all(efx);
-		efx_disable_interrupts(efx);
+		if (efx_net_active(efx->state)) {
+			efx_stop_all(efx);
+			efx_disable_interrupts(efx);
+		}
 
 		status = PCI_ERS_RESULT_NEED_RESET;
 	} else {

drivers/net/ethernet/sfc/efx_common.h

@@ -43,10 +43,11 @@ void efx_start_monitor(struct efx_nic *efx);
 int __efx_reconfigure_port(struct efx_nic *efx);
 int efx_reconfigure_port(struct efx_nic *efx);
 
-#define EFX_ASSERT_RESET_SERIALISED(efx)		\
-	do {						\
-		if (efx->state != STATE_UNINIT)		\
-			ASSERT_RTNL();			\
+#define EFX_ASSERT_RESET_SERIALISED(efx)				\
+	do {								\
+		if ((efx)->state != STATE_UNINIT &&			\
+		    (efx)->state != STATE_PROBED)			\
+			ASSERT_RTNL();					\
 	} while (0)
 
 int efx_try_recovery(struct efx_nic *efx);

drivers/net/ethernet/sfc/net_driver.h

@@ -623,7 +623,8 @@ enum efx_int_mode {
 
 enum nic_state {
 	STATE_UNINIT = 0,	/* device being probed/removed */
-	STATE_NET_DOWN,		/* hardware probed and netdev registered */
+	STATE_PROBED,		/* hardware probed */
+	STATE_NET_DOWN,		/* netdev registered */
 	STATE_NET_UP,		/* ready for traffic */
 	STATE_DISABLED,		/* device disabled due to hardware errors */