pci: Add helper to find a VPD resource data type

This patch adds the pci_vpd_find_tag() helper function to find VPD
resource data types in a buffer.

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>

5 files changed, 65 insertions, 42 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 084ef102b8c4..fd43feb5a350 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -7769,28 +7769,12 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
         }
 
         for (i = 0; i <= BNX2_VPD_LEN - 3; ) {
-                unsigned char val = data[i];
                 unsigned int block_end;
 
-                if (val & PCI_VPD_LRDT) {
-                        if (i + PCI_VPD_LRDT_TAG_SIZE > BNX2_VPD_LEN)
-                                break;
-
-                        if (val != PCI_VPD_LRDT_RO_DATA) {
-                                i += PCI_VPD_LRDT_TAG_SIZE +
-                                     pci_vpd_lrdt_size(&data[i]);
-
-                                continue;
-                        }
-                } else {
-                        if ((val & PCI_VPD_SRDT_TIN_MASK) == PCI_VPD_STIN_END)
-                                break;
-
-                        i += PCI_VPD_SRDT_TAG_SIZE +
-                             pci_vpd_srdt_size(&data[i]);
-
-                        continue;
-                }
+                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]));
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index ed57a62b3ac8..76ad141ab448 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -12547,7 +12547,7 @@ skip_phy_reset:
 static void __devinit tg3_read_partno(struct tg3 *tp)
 {
         unsigned char vpd_data[TG3_NVM_VPD_LEN];   /* in little-endian format */
-        unsigned int i;
+        int i;
         u32 magic;
 
         if ((tp->tg3_flags3 & TG3_FLG3_NO_NVRAM) ||
@@ -12586,28 +12586,12 @@ 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 char val = vpd_data[i];
                 unsigned int block_end;
 
-                if (val & PCI_VPD_LRDT) {
-                        if (i + PCI_VPD_LRDT_TAG_SIZE > TG3_NVM_VPD_LEN)
-                                break;
-
-                        if (val != PCI_VPD_LRDT_RO_DATA) {
-                                i += PCI_VPD_LRDT_TAG_SIZE +
-                                     pci_vpd_lrdt_size(&vpd_data[i]);
-
-                                continue;
-                        }
-                } else {
-                        if ((val & PCI_VPD_SRDT_TIN_MASK) == PCI_VPD_STIN_END)
-                                break;
-
-                        i += PCI_VPD_SRDT_TAG_SIZE +
-                             pci_vpd_srdt_size(&vpd_data[i]);
-
-                        continue;
-                }
+                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]);
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 4df48d58eaa6..b2f6d777a084 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -4,7 +4,7 @@
 
 obj-y           += access.o bus.o probe.o remove.o pci.o quirks.o \
                         pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
-                        irq.o
+                        irq.o vpd.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSFS) += slot.o
 
diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
new file mode 100644
index 000000000000..6bc554576f8d
--- /dev/null
+++ b/drivers/pci/vpd.c
@@ -0,0 +1,43 @@
+/*
+ * File:        vpd.c
+ * Purpose:     Provide PCI VPD support
+ *
+ * Copyright (C) 2010 Broadcom Corporation.
+ */
+
+#include <linux/pci.h>
+
+int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
+{
+        int i;
+
+        for (i = off; i < len; ) {
+                u8 val = buf[i];
+
+                if (val & PCI_VPD_LRDT) {
+                        /* Don't return success of the tag isn't complete */
+                        if (i + PCI_VPD_LRDT_TAG_SIZE > len)
+                                break;
+
+                        if (val == rdt)
+                                return i;
+
+                        i += PCI_VPD_LRDT_TAG_SIZE +
+                             pci_vpd_lrdt_size(&buf[i]);
+                } else {
+                        u8 tag = val & ~PCI_VPD_SRDT_LEN_MASK;
+
+                        if (tag == rdt)
+                                return i;
+
+                        if (tag == PCI_VPD_SRDT_END)
+                                break;
+
+                        i += PCI_VPD_SRDT_TAG_SIZE +
+                             pci_vpd_srdt_size(&buf[i]);
+                }
+        }
+
+        return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(pci_vpd_find_tag);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 198d062640b7..e30ceea7345b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1395,5 +1395,17 @@ static inline u8 pci_vpd_srdt_size(const u8 *srdt)
         return (*srdt) & PCI_VPD_SRDT_LEN_MASK;
 }
 
+/**
+ * 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
+ * @len: The length of the vpd buffer
+ * @rdt: The Resource Data Type to search for
+ *
+ * Returns the index where the Resource Data Type was found or
+ * -ENOENT otherwise.
+ */
+int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt);
+
 #endif /* __KERNEL__ */
 #endif /* LINUX_PCI_H */