drivers/pci/vpd.c

   1 /*
   2  * File:        vpd.c
   3  * Purpose:     Provide PCI VPD support
   4  *
   5  * Copyright (C) 2010 Broadcom Corporation.
   6  */
   7
   8 #include <linux/pci.h>
   9
  10 int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
  11 {
  12         int i;
  13
  14         for (i = off; i < len; ) {
  15                 u8 val = buf[i];
  16
  17                 if (val & PCI_VPD_LRDT) {
  18                         /* Don't return success of the tag isn't complete */
  19                         if (i + PCI_VPD_LRDT_TAG_SIZE > len)
  20                                 break;
  21
  22                         if (val == rdt)
  23                                 return i;
  24
  25                         i += PCI_VPD_LRDT_TAG_SIZE +
  26                              pci_vpd_lrdt_size(&buf[i]);
  27                 } else {
  28                         u8 tag = val & ~PCI_VPD_SRDT_LEN_MASK;
  29
  30                         if (tag == rdt)
  31                                 return i;
  32
  33                         if (tag == PCI_VPD_SRDT_END)
  34                                 break;
  35
  36                         i += PCI_VPD_SRDT_TAG_SIZE +
  37                              pci_vpd_srdt_size(&buf[i]);
  38                 }
  39         }
  40
  41         return -ENOENT;
  42 }
  43 EXPORT_SYMBOL_GPL(pci_vpd_find_tag);