sfc: Search VPD with pci_vpd_find_ro_info_keyword()

Use pci_vpd_find_ro_info_keyword() to search for keywords in VPD to
simplify the code.

Replace netif_err() with pci_err() because the netdevice isn't registered
yet, which results in very ugly messages.

Use kmemdup_nul() instead of open-coding it.

Link: https://lore.kernel.org/r/bf5d4ba9-61a9-2bfe-19ec-75472732d74d@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/net/ethernet/sfc/efx.c

@@ -905,67 +905,30 @@ static void efx_pci_remove(struct pci_dev *pci_dev)
 static void efx_probe_vpd_strings(struct efx_nic *efx)
 {
 	struct pci_dev *dev = efx->pci_dev;
-	int ro_start, ro_size, i, j;
-	unsigned int vpd_size;
+	unsigned int vpd_size, kw_len;
 	u8 *vpd_data;
+	int start;
 
 	vpd_data = pci_vpd_alloc(dev, &vpd_size);
 	if (IS_ERR(vpd_data)) {
 		pci_warn(dev, "Unable to read VPD\n");
 		return;
 	}
 
-	/* Get the Read only section */
-	ro_start = pci_vpd_find_tag(vpd_data, vpd_size, PCI_VPD_LRDT_RO_DATA);
-	if (ro_start < 0) {
-		netif_err(efx, drv, efx->net_dev, "VPD Read-only not found\n");
-		goto out;
-	}
-
-	ro_size = pci_vpd_lrdt_size(&vpd_data[ro_start]);
-	j = ro_size;
-	i = ro_start + PCI_VPD_LRDT_TAG_SIZE;
-	if (i + j > vpd_size)
-		j = vpd_size - i;
-
-	/* Get the Part number */
-	i = pci_vpd_find_info_keyword(vpd_data, i, j, "PN");
-	if (i < 0) {
-		netif_err(efx, drv, efx->net_dev, "Part number not found\n");
-		goto out;
-	}
-
-	j = pci_vpd_info_field_size(&vpd_data[i]);
-	i += PCI_VPD_INFO_FLD_HDR_SIZE;
-	if (i + j > vpd_size) {
-		netif_err(efx, drv, efx->net_dev, "Incomplete part number\n");
-		goto out;
-	}
-
-	netif_info(efx, drv, efx->net_dev,
-		   "Part Number : %.*s\n", j, &vpd_data[i]);
-
-	i = ro_start + PCI_VPD_LRDT_TAG_SIZE;
-	j = ro_size;
-	i = pci_vpd_find_info_keyword(vpd_data, i, j, "SN");
-	if (i < 0) {
-		netif_err(efx, drv, efx->net_dev, "Serial number not found\n");
-		goto out;
-	}
-
-	j = pci_vpd_info_field_size(&vpd_data[i]);
-	i += PCI_VPD_INFO_FLD_HDR_SIZE;
-	if (i + j > vpd_size) {
-		netif_err(efx, drv, efx->net_dev, "Incomplete serial number\n");
-		goto out;
-	}
+	start = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
+					     PCI_VPD_RO_KEYWORD_PARTNO, &kw_len);
+	if (start < 0)
+		pci_err(dev, "Part number not found or incomplete\n");
+	else
+		pci_info(dev, "Part Number : %.*s\n", kw_len, vpd_data + start);
 
-	efx->vpd_sn = kmalloc(j + 1, GFP_KERNEL);
-	if (!efx->vpd_sn)
-		goto out;
+	start = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
+					     PCI_VPD_RO_KEYWORD_SERIALNO, &kw_len);
+	if (start < 0)
+		pci_err(dev, "Serial number not found or incomplete\n");
+	else
+		efx->vpd_sn = kmemdup_nul(vpd_data + start, kw_len, GFP_KERNEL);
 
-	snprintf(efx->vpd_sn, j + 1, "%s", &vpd_data[i]);
-out:
 	kfree(vpd_data);
 }