drivers/pci/vpd.c

// SPDX-License-Identifier: GPL-2.0
/*
 * File:	vpd.c
 * Purpose:	Provide PCI VPD support
 *
 * Copyright (C) 2010 Broadcom Corporation.
 */

#include <linux/pci.h>
#include <linux/export.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);

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);