diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 5883b244647f..dee13eedde8b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -11751,20 +11751,16 @@ static int bnxt_init_mac_addr(struct bnxt *bp)
 static int bnxt_pcie_dsn_get(struct bnxt *bp, u8 dsn[])
 {
 	struct pci_dev *pdev = bp->pdev;
-	int pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DSN);
-	u32 dw;
+	u64 qword;
 
-	if (!pos) {
-		netdev_info(bp->dev, "Unable do read adapter's DSN\n");
+	qword = pci_get_dsn(pdev);
+	if (!qword) {
+		netdev_info(bp->dev, "Unable to read adapter's DSN\n");
 		return -EOPNOTSUPP;
 	}
 
-	/* DSN (two dw) is at an offset of 4 from the cap pos */
-	pos += 4;
-	pci_read_config_dword(pdev, pos, &dw);
-	put_unaligned_le32(dw, &dsn[0]);
-	pci_read_config_dword(pdev, pos + 4, &dw);
-	put_unaligned_le32(dw, &dsn[4]);
+	put_unaligned_le64(qword, dsn);
+
 	bp->flags |= BNXT_FLAG_DSN_VALID;
 	return 0;
 }
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 3aa3fc37c70e..b94a668b5c28 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -3087,30 +3087,22 @@ static char *ice_get_opt_fw_name(struct ice_pf *pf)
 	 * 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;
+	dsn = pci_get_dsn(pdev);
+	if (!dsn)
+		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]);
-	}
+	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;
 }
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c
index ccd852ad62a4..ec7a11d13fdc 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c
@@ -968,8 +968,7 @@ int ixgbe_fcoe_get_hbainfo(struct net_device *netdev,
 {
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
 	struct ixgbe_hw *hw = &adapter->hw;
-	int i, pos;
-	u8 buf[8];
+	u64 dsn;
 
 	if (!info)
 		return -EINVAL;
@@ -985,17 +984,11 @@ int ixgbe_fcoe_get_hbainfo(struct net_device *netdev,
 	/* Serial Number */
 
 	/* Get the PCI-e Device Serial Number Capability */
-	pos = pci_find_ext_capability(adapter->pdev, PCI_EXT_CAP_ID_DSN);
-	if (pos) {
-		pos += 4;
-		for (i = 0; i < 8; i++)
-			pci_read_config_byte(adapter->pdev, pos + i, &buf[i]);
-
+	dsn = pci_get_dsn(adapter->pdev);
+	if (dsn)
 		snprintf(info->serial_number, sizeof(info->serial_number),
-			 "%02X%02X%02X%02X%02X%02X%02X%02X",
-			 buf[7], buf[6], buf[5], buf[4],
-			 buf[3], buf[2], buf[1], buf[0]);
-	} else
+			 "%016llX", dsn);
+	else
 		snprintf(info->serial_number, sizeof(info->serial_number),
 			 "Unknown");
 
diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c
index b454db283aef..8fde6c1f681b 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c
@@ -1247,19 +1247,16 @@ static void nfp6000_free(struct nfp_cpp *cpp)
 static int nfp6000_read_serial(struct device *dev, u8 *serial)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
-	int pos;
-	u32 reg;
+	u64 dsn;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DSN);
-	if (!pos) {
+	dsn = pci_get_dsn(pdev);
+	if (!dsn) {
 		dev_err(dev, "can't find PCIe Serial Number Capability\n");
 		return -EINVAL;
 	}
 
-	pci_read_config_dword(pdev, pos + 4, &reg);
-	put_unaligned_be16(reg >> 16, serial + 4);
-	pci_read_config_dword(pdev, pos + 8, &reg);
-	put_unaligned_be32(reg, serial);
+	put_unaligned_be32((u32)(dsn >> 32), serial);
+	put_unaligned_be16((u16)(dsn >> 16), serial + 4);
 
 	return 0;
 }
@@ -1267,18 +1264,15 @@ static int nfp6000_read_serial(struct device *dev, u8 *serial)
 static int nfp6000_get_interface(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
-	int pos;
-	u32 reg;
+	u64 dsn;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DSN);
-	if (!pos) {
+	dsn = pci_get_dsn(pdev);
+	if (!dsn) {
 		dev_err(dev, "can't find PCIe Serial Number Capability\n");
 		return -EINVAL;
 	}
 
-	pci_read_config_dword(pdev, pos + 4, &reg);
-
-	return reg & 0xffff;
+	return dsn & 0xffff;
 }
 
 static const struct nfp_cpp_operations nfp6000_pcie_ops = {
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c16b0ba2a895..86821313c007 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -580,6 +580,40 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap)
 }
 EXPORT_SYMBOL_GPL(pci_find_ext_capability);
 
+/**
+ * pci_get_dsn - Read and return the 8-byte Device Serial Number
+ * @dev: PCI device to query
+ *
+ * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial
+ * Number.
+ *
+ * Returns the DSN, or zero if the capability does not exist.
+ */
+u64 pci_get_dsn(struct pci_dev *dev)
+{
+	u32 dword;
+	u64 dsn;
+	int pos;
+
+	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
+	if (!pos)
+		return 0;
+
+	/*
+	 * The Device Serial Number is two dwords offset 4 bytes from the
+	 * capability position. The specification says that the first dword is
+	 * the lower half, and the second dword is the upper half.
+	 */
+	pos += 4;
+	pci_read_config_dword(dev, pos, &dword);
+	dsn = (u64)dword;
+	pci_read_config_dword(dev, pos + 4, &dword);
+	dsn |= ((u64)dword) << 32;
+
+	return dsn;
+}
+EXPORT_SYMBOL_GPL(pci_get_dsn);
+
 static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
 {
 	int rc, ttl = PCI_FIND_CAP_TTL;
diff --git a/drivers/scsi/qedf/qedf_main.c b/drivers/scsi/qedf/qedf_main.c
index 604856e72cfb..5b19f5175c5c 100644
--- a/drivers/scsi/qedf/qedf_main.c
+++ b/drivers/scsi/qedf/qedf_main.c
@@ -1577,8 +1577,7 @@ static void qedf_setup_fdmi(struct qedf_ctx *qedf)
 {
 	struct fc_lport *lport = qedf->lport;
 	struct fc_host_attrs *fc_host = shost_to_fc_host(lport->host);
-	u8 buf[8];
-	int i, pos;
+	u64 dsn;
 
 	/*
 	 * fdmi_enabled needs to be set for libfc to execute FDMI registration.
@@ -1591,18 +1590,11 @@ static void qedf_setup_fdmi(struct qedf_ctx *qedf)
 	 */
 
 	/* Get the PCI-e Device Serial Number Capability */
-	pos = pci_find_ext_capability(qedf->pdev, PCI_EXT_CAP_ID_DSN);
-	if (pos) {
-		pos += 4;
-		for (i = 0; i < 8; i++)
-			pci_read_config_byte(qedf->pdev, pos + i, &buf[i]);
-
+	dsn = pci_get_dsn(qedf->pdev);
+	if (dsn)
 		snprintf(fc_host->serial_number,
-		    sizeof(fc_host->serial_number),
-		    "%02X%02X%02X%02X%02X%02X%02X%02X",
-		    buf[7], buf[6], buf[5], buf[4],
-		    buf[3], buf[2], buf[1], buf[0]);
-	} else
+		    sizeof(fc_host->serial_number), "%016llX", dsn);
+	else
 		snprintf(fc_host->serial_number,
 		    sizeof(fc_host->serial_number), "Unknown");
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7beaf51e98ec..fc54b8922e66 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1052,6 +1052,8 @@ int pci_find_ht_capability(struct pci_dev *dev, int ht_cap);
 int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap);
 struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
 
+u64 pci_get_dsn(struct pci_dev *dev);
+
 struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
 			       struct pci_dev *from);
 struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
@@ -1707,6 +1709,9 @@ static inline int pci_find_next_capability(struct pci_dev *dev, u8 post,
 static inline int pci_find_ext_capability(struct pci_dev *dev, int cap)
 { return 0; }
 
+static inline u64 pci_get_dsn(struct pci_dev *dev)
+{ return 0; }
+
 /* Power management related routines */
 static inline int pci_save_state(struct pci_dev *dev) { return 0; }
 static inline void pci_restore_state(struct pci_dev *dev) { }