cxgb4: extend VPD parsing

Current code parses the VPD RO section for keywords but makes static
assumptions about the location of the section.  Remove them and parse
the VPD to find it.
Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/cxgb4/t4_hw.c

@@ -330,18 +330,6 @@ int t4_edc_read(struct adapter *adap, int idx, u32 addr, __be32 *data, u64 *ecc)
 	return 0;
 }
 
-/*
- * Partial EEPROM Vital Product Data structure.  Includes only the ID and
- * VPD-R header.
- */
-struct t4_vpd_hdr {
-	u8  id_tag;
-	u8  id_len[2];
-	u8  id_data[ID_LEN];
-	u8  vpdr_tag;
-	u8  vpdr_len[2];
-};
-
 #define EEPROM_STAT_ADDR   0x7bfc
 #define VPD_BASE           0
 #define VPD_LEN            512
@@ -372,23 +360,36 @@ static int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	int i, ret;
 	int ec, sn;
 	u8 vpd[VPD_LEN], csum;
-	unsigned int vpdr_len;
-	const struct t4_vpd_hdr *v;
+	unsigned int vpdr_len, kw_offset, id_len;
 
 	ret = pci_read_vpd(adapter->pdev, VPD_BASE, sizeof(vpd), vpd);
 	if (ret < 0)
 		return ret;
 
-	v = (const struct t4_vpd_hdr *)vpd;
-	vpdr_len = pci_vpd_lrdt_size(&v->vpdr_tag);
-	if (vpdr_len + sizeof(struct t4_vpd_hdr) > VPD_LEN) {
+	if (vpd[0] != PCI_VPD_LRDT_ID_STRING) {
+		dev_err(adapter->pdev_dev, "missing VPD ID string\n");
+		return -EINVAL;
+	}
+
+	id_len = pci_vpd_lrdt_size(vpd);
+	if (id_len > ID_LEN)
+		id_len = ID_LEN;
+
+	i = pci_vpd_find_tag(vpd, 0, VPD_LEN, PCI_VPD_LRDT_RO_DATA);
+	if (i < 0) {
+		dev_err(adapter->pdev_dev, "missing VPD-R section\n");
+		return -EINVAL;
+	}
+
+	vpdr_len = pci_vpd_lrdt_size(&vpd[i]);
+	kw_offset = i + PCI_VPD_LRDT_TAG_SIZE;
+	if (vpdr_len + kw_offset > VPD_LEN) {
 		dev_err(adapter->pdev_dev, "bad VPD-R length %u\n", vpdr_len);
 		return -EINVAL;
 	}
 
 #define FIND_VPD_KW(var, name) do { \
-	var = pci_vpd_find_info_keyword(&v->id_tag, sizeof(struct t4_vpd_hdr), \
-					vpdr_len, name); \
+	var = pci_vpd_find_info_keyword(vpd, kw_offset, vpdr_len, name); \
 	if (var < 0) { \
 		dev_err(adapter->pdev_dev, "missing VPD keyword " name "\n"); \
 		return -EINVAL; \
@@ -410,7 +411,7 @@ static int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	FIND_VPD_KW(sn, "SN");
 #undef FIND_VPD_KW
 
-	memcpy(p->id, v->id_data, ID_LEN);
+	memcpy(p->id, vpd + PCI_VPD_LRDT_TAG_SIZE, id_len);
 	strim(p->id);
 	memcpy(p->ec, vpd + ec, EC_LEN);
 	strim(p->ec);