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-rw-r--r--drivers/char/hw_random/Kconfig15
-rw-r--r--drivers/char/hw_random/Makefile1
-rw-r--r--drivers/char/hw_random/optee-rng.c298
3 files changed, 314 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index dac895dc01b9..25a7d8ffdb5d 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -424,6 +424,21 @@ config HW_RANDOM_EXYNOS
424 will be called exynos-trng. 424 will be called exynos-trng.
425 425
426 If unsure, say Y. 426 If unsure, say Y.
427
428config HW_RANDOM_OPTEE
429 tristate "OP-TEE based Random Number Generator support"
430 depends on OPTEE
431 default HW_RANDOM
432 help
433 This driver provides support for OP-TEE based Random Number
434 Generator on ARM SoCs where hardware entropy sources are not
435 accessible to normal world (Linux).
436
437 To compile this driver as a module, choose M here: the module
438 will be called optee-rng.
439
440 If unsure, say Y.
441
427endif # HW_RANDOM 442endif # HW_RANDOM
428 443
429config UML_RANDOM 444config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index e35ec3ce3a20..7c9ef4a7667f 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o
38obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o 38obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o
39obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o 39obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o
40obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o 40obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o
41obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o
diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c
new file mode 100644
index 000000000000..2b9fc8ac5500
--- /dev/null
+++ b/drivers/char/hw_random/optee-rng.c
@@ -0,0 +1,298 @@
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2018-2019 Linaro Ltd.
4 */
5
6#include <linux/delay.h>
7#include <linux/of.h>
8#include <linux/hw_random.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/tee_drv.h>
13#include <linux/uuid.h>
14
15#define DRIVER_NAME "optee-rng"
16
17#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001
18
19/*
20 * TA_CMD_GET_ENTROPY - Get Entropy from RNG
21 *
22 * param[0] (inout memref) - Entropy buffer memory reference
23 * param[1] unused
24 * param[2] unused
25 * param[3] unused
26 *
27 * Result:
28 * TEE_SUCCESS - Invoke command success
29 * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
30 * TEE_ERROR_NOT_SUPPORTED - Requested entropy size greater than size of pool
31 * TEE_ERROR_HEALTH_TEST_FAIL - Continuous health testing failed
32 */
33#define TA_CMD_GET_ENTROPY 0x0
34
35/*
36 * TA_CMD_GET_RNG_INFO - Get RNG information
37 *
38 * param[0] (out value) - value.a: RNG data-rate in bytes per second
39 * value.b: Quality/Entropy per 1024 bit of data
40 * param[1] unused
41 * param[2] unused
42 * param[3] unused
43 *
44 * Result:
45 * TEE_SUCCESS - Invoke command success
46 * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
47 */
48#define TA_CMD_GET_RNG_INFO 0x1
49
50#define MAX_ENTROPY_REQ_SZ (4 * 1024)
51
52/**
53 * struct optee_rng_private - OP-TEE Random Number Generator private data
54 * @dev: OP-TEE based RNG device.
55 * @ctx: OP-TEE context handler.
56 * @session_id: RNG TA session identifier.
57 * @data_rate: RNG data rate.
58 * @entropy_shm_pool: Memory pool shared with RNG device.
59 * @optee_rng: OP-TEE RNG driver structure.
60 */
61struct optee_rng_private {
62 struct device *dev;
63 struct tee_context *ctx;
64 u32 session_id;
65 u32 data_rate;
66 struct tee_shm *entropy_shm_pool;
67 struct hwrng optee_rng;
68};
69
70#define to_optee_rng_private(r) \
71 container_of(r, struct optee_rng_private, optee_rng)
72
73static size_t get_optee_rng_data(struct optee_rng_private *pvt_data,
74 void *buf, size_t req_size)
75{
76 u32 ret = 0;
77 u8 *rng_data = NULL;
78 size_t rng_size = 0;
79 struct tee_ioctl_invoke_arg inv_arg = {0};
80 struct tee_param param[4] = {0};
81
82 /* Invoke TA_CMD_GET_ENTROPY function of Trusted App */
83 inv_arg.func = TA_CMD_GET_ENTROPY;
84 inv_arg.session = pvt_data->session_id;
85 inv_arg.num_params = 4;
86
87 /* Fill invoke cmd params */
88 param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT;
89 param[0].u.memref.shm = pvt_data->entropy_shm_pool;
90 param[0].u.memref.size = req_size;
91 param[0].u.memref.shm_offs = 0;
92
93 ret = tee_client_invoke_func(pvt_data->ctx, &inv_arg, param);
94 if ((ret < 0) || (inv_arg.ret != 0)) {
95 dev_err(pvt_data->dev, "TA_CMD_GET_ENTROPY invoke err: %x\n",
96 inv_arg.ret);
97 return 0;
98 }
99
100 rng_data = tee_shm_get_va(pvt_data->entropy_shm_pool, 0);
101 if (IS_ERR(rng_data)) {
102 dev_err(pvt_data->dev, "tee_shm_get_va failed\n");
103 return 0;
104 }
105
106 rng_size = param[0].u.memref.size;
107 memcpy(buf, rng_data, rng_size);
108
109 return rng_size;
110}
111
112static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
113{
114 struct optee_rng_private *pvt_data = to_optee_rng_private(rng);
115 size_t read = 0, rng_size = 0;
116 int timeout = 1;
117 u8 *data = buf;
118
119 if (max > MAX_ENTROPY_REQ_SZ)
120 max = MAX_ENTROPY_REQ_SZ;
121
122 while (read == 0) {
123 rng_size = get_optee_rng_data(pvt_data, data, (max - read));
124
125 data += rng_size;
126 read += rng_size;
127
128 if (wait) {
129 if (timeout-- == 0)
130 return read;
131 msleep((1000 * (max - read)) / pvt_data->data_rate);
132 } else {
133 return read;
134 }
135 }
136
137 return read;
138}
139
140static int optee_rng_init(struct hwrng *rng)
141{
142 struct optee_rng_private *pvt_data = to_optee_rng_private(rng);
143 struct tee_shm *entropy_shm_pool = NULL;
144
145 entropy_shm_pool = tee_shm_alloc(pvt_data->ctx, MAX_ENTROPY_REQ_SZ,
146 TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
147 if (IS_ERR(entropy_shm_pool)) {
148 dev_err(pvt_data->dev, "tee_shm_alloc failed\n");
149 return PTR_ERR(entropy_shm_pool);
150 }
151
152 pvt_data->entropy_shm_pool = entropy_shm_pool;
153
154 return 0;
155}
156
157static void optee_rng_cleanup(struct hwrng *rng)
158{
159 struct optee_rng_private *pvt_data = to_optee_rng_private(rng);
160
161 tee_shm_free(pvt_data->entropy_shm_pool);
162}
163
164static struct optee_rng_private pvt_data = {
165 .optee_rng = {
166 .name = DRIVER_NAME,
167 .init = optee_rng_init,
168 .cleanup = optee_rng_cleanup,
169 .read = optee_rng_read,
170 }
171};
172
173static int get_optee_rng_info(struct device *dev)
174{
175 u32 ret = 0;
176 struct tee_ioctl_invoke_arg inv_arg = {0};
177 struct tee_param param[4] = {0};
178
179 /* Invoke TA_CMD_GET_RNG_INFO function of Trusted App */
180 inv_arg.func = TA_CMD_GET_RNG_INFO;
181 inv_arg.session = pvt_data.session_id;
182 inv_arg.num_params = 4;
183
184 /* Fill invoke cmd params */
185 param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
186
187 ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
188 if ((ret < 0) || (inv_arg.ret != 0)) {
189 dev_err(dev, "TA_CMD_GET_RNG_INFO invoke err: %x\n",
190 inv_arg.ret);
191 return -EINVAL;
192 }
193
194 pvt_data.data_rate = param[0].u.value.a;
195 pvt_data.optee_rng.quality = param[0].u.value.b;
196
197 return 0;
198}
199
200static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
201{
202 if (ver->impl_id == TEE_IMPL_ID_OPTEE)
203 return 1;
204 else
205 return 0;
206}
207
208static int optee_rng_probe(struct device *dev)
209{
210 struct tee_client_device *rng_device = to_tee_client_device(dev);
211 int ret = 0, err = -ENODEV;
212 struct tee_ioctl_open_session_arg sess_arg = {0};
213
214 /* Open context with TEE driver */
215 pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
216 NULL);
217 if (IS_ERR(pvt_data.ctx))
218 return -ENODEV;
219
220 /* Open session with hwrng Trusted App */
221 memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
222 sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
223 sess_arg.num_params = 0;
224
225 ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
226 if ((ret < 0) || (sess_arg.ret != 0)) {
227 dev_err(dev, "tee_client_open_session failed, err: %x\n",
228 sess_arg.ret);
229 err = -EINVAL;
230 goto out_ctx;
231 }
232 pvt_data.session_id = sess_arg.session;
233
234 err = get_optee_rng_info(dev);
235 if (err)
236 goto out_sess;
237
238 err = hwrng_register(&pvt_data.optee_rng);
239 if (err) {
240 dev_err(dev, "hwrng registration failed (%d)\n", err);
241 goto out_sess;
242 }
243
244 pvt_data.dev = dev;
245
246 return 0;
247
248out_sess:
249 tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
250out_ctx:
251 tee_client_close_context(pvt_data.ctx);
252
253 return err;
254}
255
256static int optee_rng_remove(struct device *dev)
257{
258 hwrng_unregister(&pvt_data.optee_rng);
259 tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
260 tee_client_close_context(pvt_data.ctx);
261
262 return 0;
263}
264
265const struct tee_client_device_id optee_rng_id_table[] = {
266 {UUID_INIT(0xab7a617c, 0xb8e7, 0x4d8f,
267 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64)},
268 {}
269};
270
271MODULE_DEVICE_TABLE(tee, optee_rng_id_table);
272
273static struct tee_client_driver optee_rng_driver = {
274 .id_table = optee_rng_id_table,
275 .driver = {
276 .name = DRIVER_NAME,
277 .bus = &tee_bus_type,
278 .probe = optee_rng_probe,
279 .remove = optee_rng_remove,
280 },
281};
282
283static int __init optee_rng_mod_init(void)
284{
285 return driver_register(&optee_rng_driver.driver);
286}
287
288static void __exit optee_rng_mod_exit(void)
289{
290 driver_unregister(&optee_rng_driver.driver);
291}
292
293module_init(optee_rng_mod_init);
294module_exit(optee_rng_mod_exit);
295
296MODULE_LICENSE("GPL v2");
297MODULE_AUTHOR("Sumit Garg <sumit.garg@linaro.org>");
298MODULE_DESCRIPTION("OP-TEE based random number generator driver");
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-26 21:25:03 -0500