xref: /optee_os/core/tee/tee_time_generic.c (revision 1bb929836182ecb96d2d9d268daa807c67596396)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2014, STMicroelectronics International N.V.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright notice,
10  * this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <kernel/panic.h>
30 #include <kernel/tee_time.h>
31 #include <string.h>
32 #include <stdlib.h>
33 #include <trace.h>
34 #include <utee_defines.h>
35 
36 struct tee_ta_time_offs {
37 	TEE_UUID uuid;
38 	TEE_Time offs;
39 	bool positive;
40 };
41 
42 static struct tee_ta_time_offs *tee_time_offs;
43 static size_t tee_time_num_offs;
44 
45 static TEE_Result tee_time_ta_get_offs(const TEE_UUID *uuid,
46 				       const TEE_Time **offs, bool *positive)
47 {
48 	size_t n;
49 
50 	for (n = 0; n < tee_time_num_offs; n++) {
51 		if (memcmp(uuid, &tee_time_offs[n].uuid, sizeof(TEE_UUID))
52 				== 0) {
53 			*offs = &tee_time_offs[n].offs;
54 			*positive = tee_time_offs[n].positive;
55 			return TEE_SUCCESS;
56 		}
57 	}
58 	return TEE_ERROR_TIME_NOT_SET;
59 }
60 
61 static TEE_Result tee_time_ta_set_offs(const TEE_UUID *uuid,
62 				       const TEE_Time *offs, bool positive)
63 {
64 	size_t n;
65 	struct tee_ta_time_offs *o;
66 
67 	for (n = 0; n < tee_time_num_offs; n++) {
68 		if (memcmp(uuid, &tee_time_offs[n].uuid, sizeof(TEE_UUID))
69 				== 0) {
70 			tee_time_offs[n].offs = *offs;
71 			tee_time_offs[n].positive = positive;
72 			return TEE_SUCCESS;
73 		}
74 	}
75 
76 	n = tee_time_num_offs + 1;
77 	o = realloc(tee_time_offs, n * sizeof(struct tee_ta_time_offs));
78 	if (!o)
79 		return TEE_ERROR_OUT_OF_MEMORY;
80 	tee_time_offs = o;
81 	tee_time_offs[tee_time_num_offs].uuid = *uuid;
82 	tee_time_offs[tee_time_num_offs].offs = *offs;
83 	tee_time_offs[tee_time_num_offs].positive = positive;
84 	tee_time_num_offs = n;
85 	return TEE_SUCCESS;
86 }
87 
88 TEE_Result tee_time_get_ta_time(const TEE_UUID *uuid, TEE_Time *time)
89 {
90 	TEE_Result res;
91 	const TEE_Time *offs;
92 	bool positive;
93 	TEE_Time t;
94 	TEE_Time t2;
95 
96 	res = tee_time_ta_get_offs(uuid, &offs, &positive);
97 	if (res != TEE_SUCCESS)
98 		return res;
99 
100 	res = tee_time_get_sys_time(&t);
101 	if (res != TEE_SUCCESS)
102 		return res;
103 
104 	if (positive) {
105 		TEE_TIME_ADD(t, *offs, t2);
106 
107 		/* Detect wrapping, the wrapped time should be returned. */
108 		if (TEE_TIME_LT(t2, t))
109 			res = TEE_ERROR_OVERFLOW;
110 	} else {
111 		TEE_TIME_SUB(t, *offs, t2);
112 
113 		/* Detect wrapping, the wrapped time should be returned. */
114 		if (TEE_TIME_LE(t, t2))
115 			res = TEE_ERROR_OVERFLOW;
116 	}
117 	*time = t2;
118 
119 	return res;
120 }
121 
122 TEE_Result tee_time_set_ta_time(const TEE_UUID *uuid, const TEE_Time *time)
123 {
124 	TEE_Result res;
125 	TEE_Time offs;
126 	TEE_Time t;
127 
128 	/* Check that time is normalized. */
129 	if (time->millis >= TEE_TIME_MILLIS_BASE)
130 		return TEE_ERROR_BAD_PARAMETERS;
131 
132 	res = tee_time_get_sys_time(&t);
133 	if (res != TEE_SUCCESS)
134 		return res;
135 
136 	if (TEE_TIME_LT(t, *time)) {
137 		TEE_TIME_SUB(*time, t, offs);
138 		return tee_time_ta_set_offs(uuid, &offs, true);
139 	} else {
140 		TEE_TIME_SUB(t, *time, offs);
141 		return tee_time_ta_set_offs(uuid, &offs, false);
142 	}
143 }
144 
145 void tee_time_busy_wait(uint32_t milliseconds_delay)
146 {
147 	TEE_Time curr;
148 	TEE_Time delta;
149 	TEE_Time end;
150 
151 	if (tee_time_get_sys_time(&curr) != TEE_SUCCESS)
152 		panic();
153 	delta.seconds = milliseconds_delay / 1000;
154 	delta.millis = milliseconds_delay % 1000;
155 	TEE_TIME_ADD(curr, delta, end);
156 
157 	while (TEE_TIME_LT(curr, end))
158 		if (tee_time_get_sys_time(&curr) != TEE_SUCCESS)
159 			panic();
160 }
161