1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2005 IBM Corporation 4 * 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 platform 15 */ 16 17 #include <linux/seq_file.h> 18 #include <linux/fs.h> 19 #include <linux/security.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/acpi.h> 23 #include <linux/tpm_eventlog.h> 24 25 #include "../tpm.h" 26 #include "common.h" 27 28 struct acpi_tcpa { 29 struct acpi_table_header hdr; 30 u16 platform_class; 31 union { 32 struct client_hdr { 33 u32 log_max_len __packed; 34 u64 log_start_addr __packed; 35 } client; 36 struct server_hdr { 37 u16 reserved; 38 u64 log_max_len __packed; 39 u64 log_start_addr __packed; 40 } server; 41 }; 42 }; 43 44 /* read binary bios log */ 45 int tpm_read_log_acpi(struct tpm_chip *chip) 46 { 47 struct acpi_tcpa *buff; 48 acpi_status status; 49 void __iomem *virt; 50 u64 len, start; 51 struct tpm_bios_log *log; 52 struct acpi_table_tpm2 *tbl; 53 struct acpi_tpm2_phy *tpm2_phy; 54 int format; 55 56 log = &chip->log; 57 58 /* Unfortuntely ACPI does not associate the event log with a specific 59 * TPM, like PPI. Thus all ACPI TPMs will read the same log. 60 */ 61 if (!chip->acpi_dev_handle) 62 return -ENODEV; 63 64 if (chip->flags & TPM_CHIP_FLAG_TPM2) { 65 status = acpi_get_table("TPM2", 1, 66 (struct acpi_table_header **)&tbl); 67 if (ACPI_FAILURE(status)) 68 return -ENODEV; 69 70 if (tbl->header.length < 71 sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) 72 return -ENODEV; 73 74 tpm2_phy = (void *)tbl + sizeof(*tbl); 75 len = tpm2_phy->log_area_minimum_length; 76 77 start = tpm2_phy->log_area_start_address; 78 if (!start || !len) 79 return -ENODEV; 80 81 format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2; 82 } else { 83 /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */ 84 status = acpi_get_table(ACPI_SIG_TCPA, 1, 85 (struct acpi_table_header **)&buff); 86 if (ACPI_FAILURE(status)) 87 return -ENODEV; 88 89 switch (buff->platform_class) { 90 case BIOS_SERVER: 91 len = buff->server.log_max_len; 92 start = buff->server.log_start_addr; 93 break; 94 case BIOS_CLIENT: 95 default: 96 len = buff->client.log_max_len; 97 start = buff->client.log_start_addr; 98 break; 99 } 100 101 format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; 102 } 103 if (!len) { 104 dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__); 105 return -EIO; 106 } 107 108 /* malloc EventLog space */ 109 log->bios_event_log = kmalloc(len, GFP_KERNEL); 110 if (!log->bios_event_log) 111 return -ENOMEM; 112 113 log->bios_event_log_end = log->bios_event_log + len; 114 115 virt = acpi_os_map_iomem(start, len); 116 if (!virt) 117 goto err; 118 119 memcpy_fromio(log->bios_event_log, virt, len); 120 121 acpi_os_unmap_iomem(virt, len); 122 return format; 123 124 err: 125 kfree(log->bios_event_log); 126 log->bios_event_log = NULL; 127 return -EIO; 128 129 } 130