pci: Add helper to search for VPD keywords

This patch adds the pci_vpd_find_info_keyword() helper function to
find information field keywords within read-only and read-write large
resource data type sections.

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>

4 files changed, 78 insertions, 43 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index b808707f83ff..bc23bfb687c3 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -7769,48 +7769,54 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
         }
 
         for (i = 0; i <= BNX2_VPD_LEN - 3; ) {
-                unsigned int block_end;
+                int j;
+                unsigned int block_end, rosize;
 
                 i = pci_vpd_find_tag(data, i, BNX2_VPD_LEN,
                                      PCI_VPD_LRDT_RO_DATA);
                 if (i < 0)
                         break;
 
-                block_end = (i + PCI_VPD_LRDT_TAG_SIZE +
-                            pci_vpd_lrdt_size(&data[i]));
+                rosize = pci_vpd_lrdt_size(&data[i]);
+                block_end = i + PCI_VPD_LRDT_TAG_SIZE + rosize;
                 i += PCI_VPD_LRDT_TAG_SIZE;
 
                 if (block_end > BNX2_VPD_LEN)
                         goto vpd_done;
 
-                while (i < (block_end - 2)) {
-                        int len = pci_vpd_info_field_size(&data[i]);
+                j = pci_vpd_find_info_keyword(data, i, rosize,
+                                              PCI_VPD_RO_KEYWORD_MFR_ID);
+                if (j > 0) {
+                        int len = pci_vpd_info_field_size(&data[j]);
 
-                        if (i + PCI_VPD_INFO_FLD_HDR_SIZE + len > block_end)
+                        if (j + PCI_VPD_INFO_FLD_HDR_SIZE + len > block_end ||
+                            len != 4 ||
+                            memcmp(&data[j + PCI_VPD_INFO_FLD_HDR_SIZE],
+                                   "1028", 4))
                                 goto vpd_done;
 
-                        if (data[i] == 'M' && data[i + 1] == 'N') {
-                                if (len != 4 ||
-                                    memcmp(&data[i + PCI_VPD_INFO_FLD_HDR_SIZE],
-                                           "1028", 4))
-                                        goto vpd_done;
-                                mn_match = true;
+                        mn_match = true;
+                }
 
-                        } else if (data[i] == 'V' && data[i + 1] == '0') {
-                                if (len > BNX2_MAX_VER_SLEN)
-                                        goto vpd_done;
+                j = pci_vpd_find_info_keyword(data, i, rosize,
+                                              PCI_VPD_RO_KEYWORD_VENDOR0);
+                if (j > 0) {
+                        int len = pci_vpd_info_field_size(&data[j]);
 
-                                v0_len = len;
-                                v0_str = &data[i + PCI_VPD_INFO_FLD_HDR_SIZE];
-                        }
-                        i += PCI_VPD_INFO_FLD_HDR_SIZE + len;
-
-                        if (mn_match && v0_str) {
-                                memcpy(bp->fw_version, v0_str, v0_len);
-                                bp->fw_version[v0_len] = ' ';
+                        j += PCI_VPD_INFO_FLD_HDR_SIZE;
+                        if (j + len > block_end || len > BNX2_MAX_VER_SLEN)
                                 goto vpd_done;
-                        }
+
+                        v0_len = len;
+                        v0_str = &data[j];
                 }
+
+                if (mn_match && v0_str) {
+                        memcpy(bp->fw_version, v0_str, v0_len);
+                        bp->fw_version[v0_len] = ' ';
+                        goto vpd_done;
+                }
+
                 goto vpd_done;
         }
 
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index f59f36910e98..204c565caa5a 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -12586,39 +12586,33 @@ static void __devinit tg3_read_partno(struct tg3 *tp)
 
         /* Now parse and find the part number. */
         for (i = 0; i < TG3_NVM_VPD_LEN - 2; ) {
-                unsigned int block_end;
+                unsigned int block_end, rosize;
 
                 i = pci_vpd_find_tag(vpd_data, i, TG3_NVM_VPD_LEN,
                                      PCI_VPD_LRDT_RO_DATA);
                 if (i < 0)
                         break;
 
-                block_end = i + PCI_VPD_LRDT_TAG_SIZE +
-                            pci_vpd_lrdt_size(&vpd_data[i]);
-
+                rosize = pci_vpd_lrdt_size(&vpd_data[i]);
+                block_end = i + PCI_VPD_LRDT_TAG_SIZE + rosize;
                 i += PCI_VPD_LRDT_TAG_SIZE;
 
                 if (block_end > TG3_NVM_VPD_LEN)
                         goto out_not_found;
 
-                while (i < (block_end - 2)) {
-                        if (vpd_data[i + 0] == 'P' &&
-                            vpd_data[i + 1] == 'N') {
-                                int partno_len = pci_vpd_info_field_size(&vpd_data[i]);
+                i = pci_vpd_find_info_keyword(vpd_data, i, rosize,
+                                              PCI_VPD_RO_KEYWORD_PARTNO);
+                if (i > 0) {
+                        u8 len = pci_vpd_info_field_size(&vpd_data[i]);
 
-                                i += PCI_VPD_INFO_FLD_HDR_SIZE;
-                                if (partno_len > TG3_BPN_SIZE ||
-                                    (partno_len + i) > TG3_NVM_VPD_LEN)
-                                        goto out_not_found;
+                        i += PCI_VPD_INFO_FLD_HDR_SIZE;
+                        if (len > TG3_BPN_SIZE ||
+                            (len + i) > TG3_NVM_VPD_LEN)
+                                break;
 
-                                memcpy(tp->board_part_number,
-                                       &vpd_data[i], partno_len);
+                        memcpy(tp->board_part_number, &vpd_data[i], len);
 
-                                /* Success. */
-                                return;
-                        }
-                        i += PCI_VPD_INFO_FLD_HDR_SIZE +
-                             pci_vpd_info_field_size(&vpd_data[i]);
+                        return;
                 }
 
                 /* Part number not found. */
diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
index 6bc554576f8d..a5a5ca17cfe6 100644
--- a/drivers/pci/vpd.c
+++ b/drivers/pci/vpd.c
@@ -41,3 +41,21 @@ int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
         return -ENOENT;
 }
 EXPORT_SYMBOL_GPL(pci_vpd_find_tag);
+
+int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
+                              unsigned int len, const char *kw)
+{
+        int i;
+
+        for (i = off; i + PCI_VPD_INFO_FLD_HDR_SIZE <= off + len;) {
+                if (buf[i + 0] == kw[0] &&
+                    buf[i + 1] == kw[1])
+                        return i;
+
+                i += PCI_VPD_INFO_FLD_HDR_SIZE +
+                     pci_vpd_info_field_size(&buf[i]);
+        }
+
+        return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(pci_vpd_find_info_keyword);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index cfff32fc6e35..1f4a52131c99 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1375,6 +1375,10 @@ void pci_request_acs(void);
 
 #define PCI_VPD_INFO_FLD_HDR_SIZE       3
 
+#define PCI_VPD_RO_KEYWORD_PARTNO       "PN"
+#define PCI_VPD_RO_KEYWORD_MFR_ID       "MN"
+#define PCI_VPD_RO_KEYWORD_VENDOR0      "V0"
+
 /**
  * pci_vpd_lrdt_size - Extracts the Large Resource Data Type length
  * @lrdt: Pointer to the beginning of the Large Resource Data Type tag
@@ -1420,5 +1424,18 @@ static inline u8 pci_vpd_info_field_size(const u8 *info_field)
  */
 int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt);
 
+/**
+ * pci_vpd_find_info_keyword - Locates an information field keyword in the VPD
+ * @buf: Pointer to buffered vpd data
+ * @off: The offset into the buffer at which to begin the search
+ * @len: The length of the buffer area, relative to off, in which to search
+ * @kw: The keyword to search for
+ *
+ * Returns the index where the information field keyword was found or
+ * -ENOENT otherwise.
+ */
+int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
+                              unsigned int len, const char *kw);
+
 #endif /* __KERNEL__ */
 #endif /* LINUX_PCI_H */