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
16 int efi_tpm_final_log_size;
17 EXPORT_SYMBOL(efi_tpm_final_log_size);
18
tpm2_calc_event_log_size(void * data,int count,void * size_info)19 static 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 */
efi_tpm_eventlog_init(void)39 int __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((unsigned long)final_tbl,
101 tbl_size + sizeof(*final_tbl));
102 efi_tpm_final_log_size = tbl_size;
103
104 out_calc:
105 early_memunmap(final_tbl, sizeof(*final_tbl));
106 out:
107 early_memunmap(log_tbl, sizeof(*log_tbl));
108 return ret;
109 }
110
111