* followed by a EUI-64 identifier (PCIe Device Serial Number)
         */
        struct pci_dev *pdev = pf->pdev;
-       char *opt_fw_filename = NULL;
-       u32 dword;
-       u8 dsn[8];
-       int pos;
+       char *opt_fw_filename;
+       u64 dsn;
 
        /* Determine the name of the optional file using the DSN (two
         * dwords following the start of the DSN Capability).
         */
-       pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DSN);
-       if (pos) {
-               opt_fw_filename = kzalloc(NAME_MAX, GFP_KERNEL);
-               if (!opt_fw_filename)
-                       return NULL;
-
-               pci_read_config_dword(pdev, pos + 4, &dword);
-               put_unaligned_le32(dword, &dsn[0]);
-               pci_read_config_dword(pdev, pos + 8, &dword);
-               put_unaligned_le32(dword, &dsn[4]);
-               snprintf(opt_fw_filename, NAME_MAX,
-                        "%sice-%02x%02x%02x%02x%02x%02x%02x%02x.pkg",
-                        ICE_DDP_PKG_PATH,
-                        dsn[7], dsn[6], dsn[5], dsn[4],
-                        dsn[3], dsn[2], dsn[1], dsn[0]);
-       }
+       dsn = pci_get_dsn(pdev);
+       if (!dsn)
+               return NULL;
+
+       opt_fw_filename = kzalloc(NAME_MAX, GFP_KERNEL);
+       if (!opt_fw_filename)
+               return NULL;
+
+       snprintf(opt_fw_filename, NAME_MAX, "%sice-%016llX.pkg",
+                ICE_DDP_PKG_PATH, dsn);
 
        return opt_fw_filename;
 }