xref: /openbmc/linux/drivers/tee/optee/device.c (revision c0d3b831)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2019 Linaro Ltd.
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/tee_drv.h>
11 #include <linux/uuid.h>
12 #include "optee_private.h"
13 
14 static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
15 {
16 	if (ver->impl_id == TEE_IMPL_ID_OPTEE)
17 		return 1;
18 	else
19 		return 0;
20 }
21 
22 static int get_devices(struct tee_context *ctx, u32 session,
23 		       struct tee_shm *device_shm, u32 *shm_size,
24 		       u32 func)
25 {
26 	int ret = 0;
27 	struct tee_ioctl_invoke_arg inv_arg;
28 	struct tee_param param[4];
29 
30 	memset(&inv_arg, 0, sizeof(inv_arg));
31 	memset(&param, 0, sizeof(param));
32 
33 	inv_arg.func = func;
34 	inv_arg.session = session;
35 	inv_arg.num_params = 4;
36 
37 	/* Fill invoke cmd params */
38 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
39 	param[0].u.memref.shm = device_shm;
40 	param[0].u.memref.size = *shm_size;
41 	param[0].u.memref.shm_offs = 0;
42 
43 	ret = tee_client_invoke_func(ctx, &inv_arg, param);
44 	if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
45 			  (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
46 		pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
47 		       inv_arg.ret);
48 		return -EINVAL;
49 	}
50 
51 	*shm_size = param[0].u.memref.size;
52 
53 	return 0;
54 }
55 
56 static void optee_release_device(struct device *dev)
57 {
58 	struct tee_client_device *optee_device = to_tee_client_device(dev);
59 
60 	kfree(optee_device);
61 }
62 
63 static int optee_register_device(const uuid_t *device_uuid)
64 {
65 	struct tee_client_device *optee_device = NULL;
66 	int rc;
67 
68 	optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
69 	if (!optee_device)
70 		return -ENOMEM;
71 
72 	optee_device->dev.bus = &tee_bus_type;
73 	optee_device->dev.release = optee_release_device;
74 	if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
75 		kfree(optee_device);
76 		return -ENOMEM;
77 	}
78 	uuid_copy(&optee_device->id.uuid, device_uuid);
79 
80 	rc = device_register(&optee_device->dev);
81 	if (rc) {
82 		pr_err("device registration failed, err: %d\n", rc);
83 		put_device(&optee_device->dev);
84 	}
85 
86 	return rc;
87 }
88 
89 static int __optee_enumerate_devices(u32 func)
90 {
91 	const uuid_t pta_uuid =
92 		UUID_INIT(0x7011a688, 0xddde, 0x4053,
93 			  0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
94 	struct tee_ioctl_open_session_arg sess_arg;
95 	struct tee_shm *device_shm = NULL;
96 	const uuid_t *device_uuid = NULL;
97 	struct tee_context *ctx = NULL;
98 	u32 shm_size = 0, idx, num_devices = 0;
99 	int rc;
100 
101 	memset(&sess_arg, 0, sizeof(sess_arg));
102 
103 	/* Open context with OP-TEE driver */
104 	ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
105 	if (IS_ERR(ctx))
106 		return -ENODEV;
107 
108 	/* Open session with device enumeration pseudo TA */
109 	export_uuid(sess_arg.uuid, &pta_uuid);
110 	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
111 	sess_arg.num_params = 0;
112 
113 	rc = tee_client_open_session(ctx, &sess_arg, NULL);
114 	if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
115 		/* Device enumeration pseudo TA not found */
116 		rc = 0;
117 		goto out_ctx;
118 	}
119 
120 	rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
121 	if (rc < 0 || !shm_size)
122 		goto out_sess;
123 
124 	device_shm = tee_shm_alloc_kernel_buf(ctx, shm_size);
125 	if (IS_ERR(device_shm)) {
126 		pr_err("tee_shm_alloc_kernel_buf failed\n");
127 		rc = PTR_ERR(device_shm);
128 		goto out_sess;
129 	}
130 
131 	rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
132 	if (rc < 0)
133 		goto out_shm;
134 
135 	device_uuid = tee_shm_get_va(device_shm, 0);
136 	if (IS_ERR(device_uuid)) {
137 		pr_err("tee_shm_get_va failed\n");
138 		rc = PTR_ERR(device_uuid);
139 		goto out_shm;
140 	}
141 
142 	num_devices = shm_size / sizeof(uuid_t);
143 
144 	for (idx = 0; idx < num_devices; idx++) {
145 		rc = optee_register_device(&device_uuid[idx]);
146 		if (rc)
147 			goto out_shm;
148 	}
149 
150 out_shm:
151 	tee_shm_free(device_shm);
152 out_sess:
153 	tee_client_close_session(ctx, sess_arg.session);
154 out_ctx:
155 	tee_client_close_context(ctx);
156 
157 	return rc;
158 }
159 
160 int optee_enumerate_devices(u32 func)
161 {
162 	return  __optee_enumerate_devices(func);
163 }
164 
165 static int __optee_unregister_device(struct device *dev, void *data)
166 {
167 	if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
168 		device_unregister(dev);
169 
170 	return 0;
171 }
172 
173 void optee_unregister_devices(void)
174 {
175 	bus_for_each_dev(&tee_bus_type, NULL, NULL,
176 			 __optee_unregister_device);
177 }
178