1/*
 2 * Copyright (C) 2017 Google
 3 *
 4 * Authors:
 5 *      Thiebaud Weksteen <tweek@google.com>
 6 *
 7 * This program is free software; you can redistribute it and/or
 8 * modify it under the terms of the GNU General Public License
 9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 */
13
14#include <linux/efi.h>
15#include <linux/tpm_eventlog.h>
16
17#include "tpm.h"
18
19/* read binary bios log from EFI configuration table */
20int tpm_read_log_efi(struct tpm_chip *chip)
21{
22
23	struct linux_efi_tpm_eventlog *log_tbl;
24	struct tpm_bios_log *log;
25	u32 log_size;
26	u8 tpm_log_version;
27
28	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
29		return -ENODEV;
30
31	if (efi.tpm_log == EFI_INVALID_TABLE_ADDR)
32		return -ENODEV;
33
34	log = &chip->log;
35
36	log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl), MEMREMAP_WB);
37	if (!log_tbl) {
38		pr_err("Could not map UEFI TPM log table !\n");
39		return -ENOMEM;
40	}
41
42	log_size = log_tbl->size;
43	memunmap(log_tbl);
44
45	log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl) + log_size,
46			   MEMREMAP_WB);
47	if (!log_tbl) {
48		pr_err("Could not map UEFI TPM log table payload!\n");
49		return -ENOMEM;
50	}
51
52	/* malloc EventLog space */
53	log->bios_event_log = kmalloc(log_size, GFP_KERNEL);
54	if (!log->bios_event_log)
55		goto err_memunmap;
56	memcpy(log->bios_event_log, log_tbl->log, log_size);
57	log->bios_event_log_end = log->bios_event_log + log_size;
58
59	tpm_log_version = log_tbl->version;
60	memunmap(log_tbl);
61	return tpm_log_version;
62
63err_memunmap:
64	memunmap(log_tbl);
65	return -ENOMEM;
66}