tpm_acpi.c revision a40695edad6a69561b299272028c172e2d981666
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 <acpi/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 __attribute__ ((packed)); 37 u64 log_start_addr __attribute__ ((packed)); 38 } client; 39 struct server_hdr { 40 u16 reserved; 41 u64 log_max_len __attribute__ ((packed)); 42 u64 log_start_addr __attribute__ ((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_memory(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_memory(virt, len); 108 return 0; 109} 110