1/*
  2 * Copyright (C) 2005 IBM Corporation
  3 *
  4 * Authors:
  5 *	Seiji Munetoh <munetoh@jp.ibm.com>
  6 *	Stefan Berger <stefanb@us.ibm.com>
  7 *	Reiner Sailer <sailer@watson.ibm.com>
  8 *	Kylene Hall <kjhall@us.ibm.com>
  9 *
 10 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 11 *
 12 * Access to the eventlog extended by the TCG BIOS of PC platform
 13 *
 14 * This program is free software; you can redistribute it and/or
 15 * modify it under the terms of the GNU General Public License
 16 * as published by the Free Software Foundation; either version
 17 * 2 of the License, or (at your option) any later version.
 18 *
 19 */
 20
 21#include <linux/seq_file.h>
 22#include <linux/fs.h>
 23#include <linux/security.h>
 24#include <linux/module.h>
 25#include <linux/slab.h>
 26#include <linux/acpi.h>
 27
 28#include "tpm.h"
 29#include "tpm_eventlog.h"
 30
 31struct acpi_tcpa {
 32	struct acpi_table_header hdr;
 33	u16 platform_class;
 34	union {
 35		struct client_hdr {
 36			u32 log_max_len __packed;
 37			u64 log_start_addr __packed;
 38		} client;
 39		struct server_hdr {
 40			u16 reserved;
 41			u64 log_max_len __packed;
 42			u64 log_start_addr __packed;
 43		} server;
 44	};
 45};
 46
 47/* read binary bios log */
 48int read_log(struct tpm_bios_log *log)
 49{
 50	struct acpi_tcpa *buff;
 51	acpi_status status;
 52	void __iomem *virt;
 53	u64 len, start;
 54
 55	if (log->bios_event_log != NULL) {
 56		printk(KERN_ERR
 57		       "%s: ERROR - Eventlog already initialized\n",
 58		       __func__);
 59		return -EFAULT;
 60	}
 61
 62	/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
 63	status = acpi_get_table(ACPI_SIG_TCPA, 1,
 64				(struct acpi_table_header **)&buff);
 65
 66	if (ACPI_FAILURE(status)) {
 67		printk(KERN_ERR "%s: ERROR - Could not get TCPA table\n",
 68		       __func__);
 69		return -EIO;
 70	}
 71
 72	switch(buff->platform_class) {
 73	case BIOS_SERVER:
 74		len = buff->server.log_max_len;
 75		start = buff->server.log_start_addr;
 76		break;
 77	case BIOS_CLIENT:
 78	default:
 79		len = buff->client.log_max_len;
 80		start = buff->client.log_start_addr;
 81		break;
 82	}
 83	if (!len) {
 84		printk(KERN_ERR "%s: ERROR - TCPA log area empty\n", __func__);
 85		return -EIO;
 86	}
 87
 88	/* malloc EventLog space */
 89	log->bios_event_log = kmalloc(len, GFP_KERNEL);
 90	if (!log->bios_event_log) {
 91		printk("%s: ERROR - Not enough  Memory for BIOS measurements\n",
 92			__func__);
 93		return -ENOMEM;
 94	}
 95
 96	log->bios_event_log_end = log->bios_event_log + len;
 97
 98	virt = acpi_os_map_iomem(start, len);
 99	if (!virt) {
100		kfree(log->bios_event_log);
101		printk("%s: ERROR - Unable to map memory\n", __func__);
102		return -EIO;
103	}
104
105	memcpy_fromio(log->bios_event_log, virt, len);
106
107	acpi_os_unmap_iomem(virt, len);
108	return 0;
109}