LXR linux/drivers/char/tpm/tpm

   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}
 110