1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2017 Google, Inc.
4 *     Thiebaud Weksteen <tweek@google.com>
5 */
6
7#define TPM_MEMREMAP(start, size) early_memremap(start, size)
8#define TPM_MEMUNMAP(start, size) early_memunmap(start, size)
9
10#include <asm/early_ioremap.h>
11#include <linux/efi.h>
12#include <linux/init.h>
13#include <linux/memblock.h>
14#include <linux/tpm_eventlog.h>
15
16int efi_tpm_final_log_size;
17EXPORT_SYMBOL(efi_tpm_final_log_size);
18
19static int __init tpm2_calc_event_log_size(void *data, int count, void *size_info)
20{
21	struct tcg_pcr_event2_head *header;
22	int event_size, size = 0;
23
24	while (count > 0) {
25		header = data + size;
26		event_size = __calc_tpm2_event_size(header, size_info, true);
27		if (event_size == 0)
28			return -1;
29		size += event_size;
30		count--;
31	}
32
33	return size;
34}
35
36/*
37 * Reserve the memory associated with the TPM Event Log configuration table.
38 */
39int __init efi_tpm_eventlog_init(void)
40{
41	struct linux_efi_tpm_eventlog *log_tbl;
42	struct efi_tcg2_final_events_table *final_tbl;
43	int tbl_size;
44	int ret = 0;
45
46	if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) {
47		/*
48		 * We can't calculate the size of the final events without the
49		 * first entry in the TPM log, so bail here.
50		 */
51		return 0;
52	}
53
54	log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl));
55	if (!log_tbl) {
56		pr_err("Failed to map TPM Event Log table @ 0x%lx\n",
57		       efi.tpm_log);
58		efi.tpm_log = EFI_INVALID_TABLE_ADDR;
59		return -ENOMEM;
60	}
61
62	tbl_size = sizeof(*log_tbl) + log_tbl->size;
63	memblock_reserve(efi.tpm_log, tbl_size);
64
65	if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) {
66		pr_info("TPM Final Events table not present\n");
67		goto out;
68	} else if (log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
69		pr_warn(FW_BUG "TPM Final Events table invalid\n");
70		goto out;
71	}
72
73	final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl));
74
75	if (!final_tbl) {
76		pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n",
77		       efi.tpm_final_log);
78		efi.tpm_final_log = EFI_INVALID_TABLE_ADDR;
79		ret = -ENOMEM;
80		goto out;
81	}
82
83	tbl_size = 0;
84	if (final_tbl->nr_events != 0) {
85		void *events = (void *)efi.tpm_final_log
86				+ sizeof(final_tbl->version)
87				+ sizeof(final_tbl->nr_events);
88
89		tbl_size = tpm2_calc_event_log_size(events,
90						    final_tbl->nr_events,
91						    log_tbl->log);
92	}
93
94	if (tbl_size < 0) {
95		pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
96		ret = -EINVAL;
97		goto out_calc;
98	}
99
100	memblock_reserve(efi.tpm_final_log,
101			 tbl_size + sizeof(*final_tbl));
102	efi_tpm_final_log_size = tbl_size;
103
104out_calc:
105	early_memunmap(final_tbl, sizeof(*final_tbl));
106out:
107	early_memunmap(log_tbl, sizeof(*log_tbl));
108	return ret;
109}
110
111