Merge tag 'tpmdd-next-20190625' of git://git.infradead.org/users/jjs/linux-tpmdd
[muen/linux.git] / drivers / firmware / efi / tpm.c
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
19 static int 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  */
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         unsigned 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                 goto out;
67
68         final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl));
69
70         if (!final_tbl) {
71                 pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n",
72                        efi.tpm_final_log);
73                 efi.tpm_final_log = EFI_INVALID_TABLE_ADDR;
74                 ret = -ENOMEM;
75                 goto out;
76         }
77
78         tbl_size = tpm2_calc_event_log_size((void *)efi.tpm_final_log
79                                             + sizeof(final_tbl->version)
80                                             + sizeof(final_tbl->nr_events),
81                                             final_tbl->nr_events,
82                                             log_tbl->log);
83         memblock_reserve((unsigned long)final_tbl,
84                          tbl_size + sizeof(*final_tbl));
85         early_memunmap(final_tbl, sizeof(*final_tbl));
86         efi_tpm_final_log_size = tbl_size;
87
88 out:
89         early_memunmap(log_tbl, sizeof(*log_tbl));
90         return ret;
91 }
92