bnxt_en: Restore MSIX after disabling SRIOV.

After SRIOV has been enabled and disabled, the MSIX vectors assigned to
the VFs have to be re-initialized.  Otherwise they cannot be re-used by
the PF.  For example, increasing the number of PF rings after disabling
SRIOV may fail if the PF uses MSIX vectors previously assigned to the VFs.

To fix this, we add logic in bnxt_restore_pf_fw_resources() to close the
NIC, clear and re-init MSIX, and re-open the NIC.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -8061,11 +8061,23 @@ static int bnxt_set_dflt_rings(struct bnxt *bp, bool sh)
 	return rc;
 }
 
-void bnxt_restore_pf_fw_resources(struct bnxt *bp)
+int bnxt_restore_pf_fw_resources(struct bnxt *bp)
 {
+	int rc;
+
 	ASSERT_RTNL();
+	if (bnxt_ulp_registered(bp->edev, BNXT_ROCE_ULP))
+		return 0;
+
 	bnxt_hwrm_func_qcaps(bp);
-	bnxt_subtract_ulp_resources(bp, BNXT_ROCE_ULP);
+	__bnxt_close_nic(bp, true, false);
+	bnxt_clear_int_mode(bp);
+	rc = bnxt_init_int_mode(bp);
+	if (rc)
+		dev_close(bp->dev);
+	else
+		rc = bnxt_open_nic(bp, true, false);
+	return rc;
 }
 
 static int bnxt_init_mac_addr(struct bnxt *bp)

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1432,7 +1432,7 @@ int bnxt_check_rings(struct bnxt *bp, int tx, int rx, bool sh, int tcs,
 		     int tx_xdp);
 int bnxt_setup_mq_tc(struct net_device *dev, u8 tc);
 int bnxt_get_max_rings(struct bnxt *, int *, int *, bool);
-void bnxt_restore_pf_fw_resources(struct bnxt *bp);
+int bnxt_restore_pf_fw_resources(struct bnxt *bp);
 int bnxt_port_attr_get(struct bnxt *bp, struct switchdev_attr *attr);
 void bnxt_dim_work(struct work_struct *work);
 int bnxt_hwrm_set_ring_coal(struct bnxt *bp, struct bnxt_napi *bnapi);