xref: /linux/drivers/tee/optee/device.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
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 int optee_register_device(const uuid_t *device_uuid)
57 {
58 	struct tee_client_device *optee_device = NULL;
59 	int rc;
60 
61 	optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
62 	if (!optee_device)
63 		return -ENOMEM;
64 
65 	optee_device->dev.bus = &tee_bus_type;
66 	if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
67 		kfree(optee_device);
68 		return -ENOMEM;
69 	}
70 	uuid_copy(&optee_device->id.uuid, device_uuid);
71 
72 	rc = device_register(&optee_device->dev);
73 	if (rc) {
74 		pr_err("device registration failed, err: %d\n", rc);
75 		kfree(optee_device);
76 	}
77 
78 	return rc;
79 }
80 
81 static int __optee_enumerate_devices(u32 func)
82 {
83 	const uuid_t pta_uuid =
84 		UUID_INIT(0x7011a688, 0xddde, 0x4053,
85 			  0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
86 	struct tee_ioctl_open_session_arg sess_arg;
87 	struct tee_shm *device_shm = NULL;
88 	const uuid_t *device_uuid = NULL;
89 	struct tee_context *ctx = NULL;
90 	u32 shm_size = 0, idx, num_devices = 0;
91 	int rc;
92 
93 	memset(&sess_arg, 0, sizeof(sess_arg));
94 
95 	/* Open context with OP-TEE driver */
96 	ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
97 	if (IS_ERR(ctx))
98 		return -ENODEV;
99 
100 	/* Open session with device enumeration pseudo TA */
101 	export_uuid(sess_arg.uuid, &pta_uuid);
102 	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
103 	sess_arg.num_params = 0;
104 
105 	rc = tee_client_open_session(ctx, &sess_arg, NULL);
106 	if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
107 		/* Device enumeration pseudo TA not found */
108 		rc = 0;
109 		goto out_ctx;
110 	}
111 
112 	rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
113 	if (rc < 0 || !shm_size)
114 		goto out_sess;
115 
116 	device_shm = tee_shm_alloc(ctx, shm_size,
117 				   TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
118 	if (IS_ERR(device_shm)) {
119 		pr_err("tee_shm_alloc failed\n");
120 		rc = PTR_ERR(device_shm);
121 		goto out_sess;
122 	}
123 
124 	rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
125 	if (rc < 0)
126 		goto out_shm;
127 
128 	device_uuid = tee_shm_get_va(device_shm, 0);
129 	if (IS_ERR(device_uuid)) {
130 		pr_err("tee_shm_get_va failed\n");
131 		rc = PTR_ERR(device_uuid);
132 		goto out_shm;
133 	}
134 
135 	num_devices = shm_size / sizeof(uuid_t);
136 
137 	for (idx = 0; idx < num_devices; idx++) {
138 		rc = optee_register_device(&device_uuid[idx]);
139 		if (rc)
140 			goto out_shm;
141 	}
142 
143 out_shm:
144 	tee_shm_free(device_shm);
145 out_sess:
146 	tee_client_close_session(ctx, sess_arg.session);
147 out_ctx:
148 	tee_client_close_context(ctx);
149 
150 	return rc;
151 }
152 
153 int optee_enumerate_devices(u32 func)
154 {
155 	return  __optee_enumerate_devices(func);
156 }
157