pci: Add VPD information field helper functions

This patch adds a preprocessor constant to describe the PCI VPD
information field header size and an inline function to extract the
size of the information field itself.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 23 insertions, 8 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index fd43feb5a350..b808707f83ff 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -7784,14 +7784,15 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
                         goto vpd_done;
 
                 while (i < (block_end - 2)) {
-                        int len = data[i + 2];
+                        int len = pci_vpd_info_field_size(&data[i]);
 
-                        if (i + 3 + len > block_end)
+                        if (i + PCI_VPD_INFO_FLD_HDR_SIZE + len > block_end)
                                 goto vpd_done;
 
                         if (data[i] == 'M' && data[i + 1] == 'N') {
                                 if (len != 4 ||
-                                    memcmp(&data[i + 3], "1028", 4))
+                                    memcmp(&data[i + PCI_VPD_INFO_FLD_HDR_SIZE],
+                                           "1028", 4))
                                         goto vpd_done;
                                 mn_match = true;
 
@@ -7800,9 +7801,9 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
                                         goto vpd_done;
 
                                 v0_len = len;
-                                v0_str = &data[i + 3];
+                                v0_str = &data[i + PCI_VPD_INFO_FLD_HDR_SIZE];
                         }
-                        i += 3 + len;
+                        i += PCI_VPD_INFO_FLD_HDR_SIZE + len;
 
                         if (mn_match && v0_str) {
                                 memcpy(bp->fw_version, v0_str, v0_len);
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 76ad141ab448..f59f36910e98 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -12604,9 +12604,9 @@ static void __devinit tg3_read_partno(struct tg3 *tp)
                 while (i < (block_end - 2)) {
                         if (vpd_data[i + 0] == 'P' &&
                             vpd_data[i + 1] == 'N') {
-                                int partno_len = vpd_data[i + 2];
+                                int partno_len = pci_vpd_info_field_size(&vpd_data[i]);
 
-                                i += 3;
+                                i += PCI_VPD_INFO_FLD_HDR_SIZE;
                                 if (partno_len > TG3_BPN_SIZE ||
                                     (partno_len + i) > TG3_NVM_VPD_LEN)
                                         goto out_not_found;
@@ -12617,7 +12617,8 @@ static void __devinit tg3_read_partno(struct tg3 *tp)
                                 /* Success. */
                                 return;
                         }
-                        i += 3 + vpd_data[i + 2];
+                        i += PCI_VPD_INFO_FLD_HDR_SIZE +
+                             pci_vpd_info_field_size(&vpd_data[i]);
                 }
 
                 /* Part number not found. */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e30ceea7345b..cfff32fc6e35 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1373,6 +1373,8 @@ void pci_request_acs(void);
 #define PCI_VPD_LRDT_TAG_SIZE           3
 #define PCI_VPD_SRDT_TAG_SIZE           1
 
+#define PCI_VPD_INFO_FLD_HDR_SIZE       3
+
 /**
  * pci_vpd_lrdt_size - Extracts the Large Resource Data Type length
  * @lrdt: Pointer to the beginning of the Large Resource Data Type tag
@@ -1396,6 +1398,17 @@ static inline u8 pci_vpd_srdt_size(const u8 *srdt)
 }
 
 /**
+ * pci_vpd_info_field_size - Extracts the information field length
+ * @lrdt: Pointer to the beginning of an information field header
+ *
+ * Returns the extracted information field length.
+ */
+static inline u8 pci_vpd_info_field_size(const u8 *info_field)
+{
+        return info_field[2];
+}
+
+/**
  * pci_vpd_find_tag - Locates the Resource Data Type tag provided
  * @buf: Pointer to buffered vpd data
  * @off: The offset into the buffer at which to begin the search