1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3 * Copyright (c) 2020, ARM Limited. All rights reserved.
4 */
5
6 #include <compiler.h>
7 #include <kernel/dt.h>
8 #include <kernel/tpm.h>
9 #include <libfdt.h>
10 #include <mm/core_memprot.h>
11 #include <string.h>
12
13 static void *tpm_log_addr;
14 static size_t tpm_log_size;
15
16 /*
17 * Check whether the node at @offs contains TPM Event Log information or not.
18 *
19 * @offs is the offset of the node that describes the device in @fdt.
20 * @buf will contain the phy address of the TPM Event log.
21 * @size will contain the size of the mapped area.
22 *
23 * Returns the size of the mapped area or < 0 on failure.
24 */
25 #ifdef CFG_DT
read_dt_tpm_log_info(void * fdt,int node,paddr_t * buf,size_t * size)26 static int read_dt_tpm_log_info(void *fdt, int node, paddr_t *buf,
27 size_t *size)
28 {
29 const uint32_t *property = NULL;
30 const uint64_t zero_addr = 0;
31 int len_prop = 0;
32 paddr_t log_addr = 0;
33 int err = 0;
34
35 /*
36 * Get the TPM Log address.
37 */
38 property = fdt_getprop(fdt, node, "tpm_event_log_sm_addr", &len_prop);
39
40 if (!property || len_prop != sizeof(uint32_t) * 2)
41 return -1;
42
43 log_addr = fdt32_to_cpu(property[1]);
44
45 err = fdt_setprop(fdt, node, "tpm_event_log_sm_addr", &zero_addr,
46 sizeof(uint32_t) * 2);
47 if (err < 0) {
48 EMSG("Error setting property DTB to zero\n");
49 return err;
50 }
51
52 /*
53 * Get the TPM Log size.
54 */
55 property = fdt_getprop(fdt, node, "tpm_event_log_size", &len_prop);
56
57 if (!property || len_prop != sizeof(uint32_t))
58 return -1;
59
60 *size = fdt32_to_cpu(property[0]);
61 *buf = log_addr;
62
63 return *size;
64 }
65 #endif
66
get_tpm_phys_params(void * fdt __maybe_unused,paddr_t * addr,size_t * size)67 static void get_tpm_phys_params(void *fdt __maybe_unused,
68 paddr_t *addr, size_t *size)
69 {
70 #ifdef CFG_DT
71 int node = 0;
72 const char *dt_tpm_match_table = {
73 "arm,tpm_event_log",
74 };
75
76 if (!fdt) {
77 EMSG("TPM: No DTB found");
78 return;
79 }
80
81 node = fdt_node_offset_by_compatible(fdt, -1, dt_tpm_match_table);
82
83 if (node < 0) {
84 EMSG("TPM: Fail to find TPM node %i", node);
85 return;
86 }
87
88 if (read_dt_tpm_log_info((void *)fdt, node, addr, size) < 0) {
89 EMSG("TPM: Fail to retrieve DTB properties from node %i",
90 node);
91 return;
92 }
93 #else
94 *size = CFG_TPM_MAX_LOG_SIZE;
95 *addr = CFG_TPM_LOG_BASE_ADDR;
96 #endif /* CFG_DT */
97 }
98
tpm_get_event_log(void * buf,size_t * size)99 TEE_Result tpm_get_event_log(void *buf, size_t *size)
100 {
101 const size_t buf_size = *size;
102
103 *size = tpm_log_size;
104 if (!buf) {
105 EMSG("TPM: Invalid buffer");
106 return TEE_ERROR_BAD_PARAMETERS;
107 }
108
109 if (buf_size < tpm_log_size) {
110 EMSG("TPM: Not enough space for the log: %zu, %lu",
111 buf_size, tpm_log_size);
112 return TEE_ERROR_SHORT_BUFFER;
113 }
114
115 memcpy(buf, tpm_log_addr, tpm_log_size);
116
117 return TEE_SUCCESS;
118 }
119
tpm_map_log_area(void * fdt)120 void tpm_map_log_area(void *fdt)
121 {
122 paddr_t log_addr = 0;
123 unsigned int rounded_size = 0;
124
125 get_tpm_phys_params(fdt, &log_addr, &tpm_log_size);
126
127 DMSG("TPM Event log PA: %#" PRIxPA, log_addr);
128 DMSG("TPM Event log size: %zu Bytes", tpm_log_size);
129
130 rounded_size = ROUNDUP(tpm_log_size, SMALL_PAGE_SIZE);
131
132 tpm_log_addr = core_mmu_add_mapping(MEM_AREA_RAM_SEC, log_addr,
133 rounded_size);
134 if (!tpm_log_addr) {
135 EMSG("TPM: Failed to map TPM log memory");
136 return;
137 }
138 }
139