root/drivers/char/tpm/eventlog/acpi.c

DEFINITIONS

1. tpm_read_log_acpi

   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 }