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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2005 IBM Corporation4 *5 * Authors:6 * Seiji Munetoh <munetoh@jp.ibm.com>7 * Stefan Berger <stefanb@us.ibm.com>8 * Reiner Sailer <sailer@watson.ibm.com>9 * Kylene Hall <kjhall@us.ibm.com>10 * Nayna Jain <nayna@linux.vnet.ibm.com>11 *12 * Maintained by: <tpmdd-devel@lists.sourceforge.net>13 *14 * Access to the event log extended by the TCG BIOS of PC platform15 */16 17#include <linux/device.h>18#include <linux/seq_file.h>19#include <linux/fs.h>20#include <linux/security.h>21#include <linux/module.h>22#include <linux/slab.h>23#include <linux/acpi.h>24#include <linux/tpm_eventlog.h>25 26#include "../tpm.h"27#include "common.h"28 29struct acpi_tcpa {30 struct acpi_table_header hdr;31 u16 platform_class;32 union {33 struct client_hdr {34 u32 log_max_len __packed;35 u64 log_start_addr __packed;36 } client;37 struct server_hdr {38 u16 reserved;39 u64 log_max_len __packed;40 u64 log_start_addr __packed;41 } server;42 };43};44 45/* Check that the given log is indeed a TPM2 log. */46static bool tpm_is_tpm2_log(void *bios_event_log, u64 len)47{48 struct tcg_efi_specid_event_head *efispecid;49 struct tcg_pcr_event *event_header;50 int n;51 52 if (len < sizeof(*event_header))53 return false;54 len -= sizeof(*event_header);55 event_header = bios_event_log;56 57 if (len < sizeof(*efispecid))58 return false;59 efispecid = (struct tcg_efi_specid_event_head *)event_header->event;60 61 n = memcmp(efispecid->signature, TCG_SPECID_SIG,62 sizeof(TCG_SPECID_SIG));63 return n == 0;64}65 66/* read binary bios log */67int tpm_read_log_acpi(struct tpm_chip *chip)68{69 struct acpi_tcpa *buff;70 acpi_status status;71 void __iomem *virt;72 u64 len, start;73 struct tpm_bios_log *log;74 struct acpi_table_tpm2 *tbl;75 struct acpi_tpm2_phy *tpm2_phy;76 int format;77 int ret;78 79 log = &chip->log;80 81 /* Unfortuntely ACPI does not associate the event log with a specific82 * TPM, like PPI. Thus all ACPI TPMs will read the same log.83 */84 if (!chip->acpi_dev_handle)85 return -ENODEV;86 87 if (chip->flags & TPM_CHIP_FLAG_TPM2) {88 status = acpi_get_table("TPM2", 1,89 (struct acpi_table_header **)&tbl);90 if (ACPI_FAILURE(status))91 return -ENODEV;92 93 if (tbl->header.length <94 sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) {95 acpi_put_table((struct acpi_table_header *)tbl);96 return -ENODEV;97 }98 99 tpm2_phy = (void *)tbl + sizeof(*tbl);100 len = tpm2_phy->log_area_minimum_length;101 102 start = tpm2_phy->log_area_start_address;103 if (!start || !len) {104 acpi_put_table((struct acpi_table_header *)tbl);105 return -ENODEV;106 }107 108 acpi_put_table((struct acpi_table_header *)tbl);109 format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;110 } else {111 /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */112 status = acpi_get_table(ACPI_SIG_TCPA, 1,113 (struct acpi_table_header **)&buff);114 if (ACPI_FAILURE(status))115 return -ENODEV;116 117 switch (buff->platform_class) {118 case BIOS_SERVER:119 len = buff->server.log_max_len;120 start = buff->server.log_start_addr;121 break;122 case BIOS_CLIENT:123 default:124 len = buff->client.log_max_len;125 start = buff->client.log_start_addr;126 break;127 }128 129 acpi_put_table((struct acpi_table_header *)buff);130 format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;131 }132 133 if (!len) {134 dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);135 return -EIO;136 }137 138 /* malloc EventLog space */139 log->bios_event_log = devm_kmalloc(&chip->dev, len, GFP_KERNEL);140 if (!log->bios_event_log)141 return -ENOMEM;142 143 log->bios_event_log_end = log->bios_event_log + len;144 145 virt = acpi_os_map_iomem(start, len);146 if (!virt) {147 dev_warn(&chip->dev, "%s: Failed to map ACPI memory\n", __func__);148 /* try EFI log next */149 ret = -ENODEV;150 goto err;151 }152 153 memcpy_fromio(log->bios_event_log, virt, len);154 155 acpi_os_unmap_iomem(virt, len);156 157 if (chip->flags & TPM_CHIP_FLAG_TPM2 &&158 !tpm_is_tpm2_log(log->bios_event_log, len)) {159 /* try EFI log next */160 ret = -ENODEV;161 goto err;162 }163 164 return format;165 166err:167 devm_kfree(&chip->dev, log->bios_event_log);168 log->bios_event_log = NULL;169 return ret;170}171