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 53 if (chip->flags & TPM_CHIP_FLAG_TPM2) 54 return -ENODEV; 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 /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */ 65 status = acpi_get_table(ACPI_SIG_TCPA, 1, 66 (struct acpi_table_header **)&buff); 67 68 if (ACPI_FAILURE(status)) 69 return -ENODEV; 70 71 switch(buff->platform_class) { 72 case BIOS_SERVER: 73 len = buff->server.log_max_len; 74 start = buff->server.log_start_addr; 75 break; 76 case BIOS_CLIENT: 77 default: 78 len = buff->client.log_max_len; 79 start = buff->client.log_start_addr; 80 break; 81 } 82 if (!len) { 83 dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__); 84 return -EIO; 85 } 86 87 /* malloc EventLog space */ 88 log->bios_event_log = kmalloc(len, GFP_KERNEL); 89 if (!log->bios_event_log) 90 return -ENOMEM; 91 92 log->bios_event_log_end = log->bios_event_log + len; 93 94 virt = acpi_os_map_iomem(start, len); 95 if (!virt) 96 goto err; 97 98 memcpy_fromio(log->bios_event_log, virt, len); 99 100 acpi_os_unmap_iomem(virt, len); 101 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; 102 103 err: 104 kfree(log->bios_event_log); 105 log->bios_event_log = NULL; 106 return -EIO; 107 108 } 109