drivers/pci/vpd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * File:        vpd.c
   4  * Purpose:     Provide PCI VPD support
   5  *
   6  * Copyright (C) 2010 Broadcom Corporation.
   7  */
   8
   9 #include <linux/pci.h>
  10 #include <linux/export.h>
  11
  12 int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
  13 {
  14         int i;
  15
  16         for (i = off; i < len; ) {
  17                 u8 val = buf[i];
  18
  19                 if (val & PCI_VPD_LRDT) {
  20                         /* Don't return success of the tag isn't complete */
  21                         if (i + PCI_VPD_LRDT_TAG_SIZE > len)
  22                                 break;
  23
  24                         if (val == rdt)
  25                                 return i;
  26
  27                         i += PCI_VPD_LRDT_TAG_SIZE +
  28                              pci_vpd_lrdt_size(&buf[i]);
  29                 } else {
  30                         u8 tag = val & ~PCI_VPD_SRDT_LEN_MASK;
  31
  32                         if (tag == rdt)
  33                                 return i;
  34
  35                         if (tag == PCI_VPD_SRDT_END)
  36                                 break;
  37
  38                         i += PCI_VPD_SRDT_TAG_SIZE +
  39                              pci_vpd_srdt_size(&buf[i]);
  40                 }
  41         }
  42
  43         return -ENOENT;
  44 }
  45 EXPORT_SYMBOL_GPL(pci_vpd_find_tag);
  46
  47 int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
  48                               unsigned int len, const char *kw)
  49 {
  50         int i;
  51
  52         for (i = off; i + PCI_VPD_INFO_FLD_HDR_SIZE <= off + len;) {
  53                 if (buf[i + 0] == kw[0] &&
  54                     buf[i + 1] == kw[1])
  55                         return i;
  56
  57                 i += PCI_VPD_INFO_FLD_HDR_SIZE +
  58                      pci_vpd_info_field_size(&buf[i]);
  59         }
  60
  61         return -ENOENT;
  62 }
  63 EXPORT_SYMBOL_GPL(pci_vpd_find_info_keyword);