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
14static 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
22static 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
56static 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
63static ssize_t need_supplicant_show(struct device *dev,
64				    struct device_attribute *attr,
65				    char *buf)
66{
67	return 0;
68}
69
70static DEVICE_ATTR_RO(need_supplicant);
71
72static int optee_register_device(const uuid_t *device_uuid, u32 func)
73{
74	struct tee_client_device *optee_device = NULL;
75	int rc;
76
77	optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
78	if (!optee_device)
79		return -ENOMEM;
80
81	optee_device->dev.bus = &tee_bus_type;
82	optee_device->dev.release = optee_release_device;
83	if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
84		kfree(optee_device);
85		return -ENOMEM;
86	}
87	uuid_copy(&optee_device->id.uuid, device_uuid);
88
89	rc = device_register(&optee_device->dev);
90	if (rc) {
91		pr_err("device registration failed, err: %d\n", rc);
92		put_device(&optee_device->dev);
93		return rc;
94	}
95
96	if (func == PTA_CMD_GET_DEVICES_SUPP)
97		device_create_file(&optee_device->dev,
98				   &dev_attr_need_supplicant);
99
100	return 0;
101}
102
103static int __optee_enumerate_devices(u32 func)
104{
105	const uuid_t pta_uuid =
106		UUID_INIT(0x7011a688, 0xddde, 0x4053,
107			  0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
108	struct tee_ioctl_open_session_arg sess_arg;
109	struct tee_shm *device_shm = NULL;
110	const uuid_t *device_uuid = NULL;
111	struct tee_context *ctx = NULL;
112	u32 shm_size = 0, idx, num_devices = 0;
113	int rc;
114
115	memset(&sess_arg, 0, sizeof(sess_arg));
116
117	/* Open context with OP-TEE driver */
118	ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
119	if (IS_ERR(ctx))
120		return -ENODEV;
121
122	/* Open session with device enumeration pseudo TA */
123	export_uuid(sess_arg.uuid, &pta_uuid);
124	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
125	sess_arg.num_params = 0;
126
127	rc = tee_client_open_session(ctx, &sess_arg, NULL);
128	if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
129		/* Device enumeration pseudo TA not found */
130		rc = 0;
131		goto out_ctx;
132	}
133
134	rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
135	if (rc < 0 || !shm_size)
136		goto out_sess;
137
138	device_shm = tee_shm_alloc_kernel_buf(ctx, shm_size);
139	if (IS_ERR(device_shm)) {
140		pr_err("tee_shm_alloc_kernel_buf failed\n");
141		rc = PTR_ERR(device_shm);
142		goto out_sess;
143	}
144
145	rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
146	if (rc < 0)
147		goto out_shm;
148
149	device_uuid = tee_shm_get_va(device_shm, 0);
150	if (IS_ERR(device_uuid)) {
151		pr_err("tee_shm_get_va failed\n");
152		rc = PTR_ERR(device_uuid);
153		goto out_shm;
154	}
155
156	num_devices = shm_size / sizeof(uuid_t);
157
158	for (idx = 0; idx < num_devices; idx++) {
159		rc = optee_register_device(&device_uuid[idx], func);
160		if (rc)
161			goto out_shm;
162	}
163
164out_shm:
165	tee_shm_free(device_shm);
166out_sess:
167	tee_client_close_session(ctx, sess_arg.session);
168out_ctx:
169	tee_client_close_context(ctx);
170
171	return rc;
172}
173
174int optee_enumerate_devices(u32 func)
175{
176	return  __optee_enumerate_devices(func);
177}
178
179static int __optee_unregister_device(struct device *dev, void *data)
180{
181	if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
182		device_unregister(dev);
183
184	return 0;
185}
186
187void optee_unregister_devices(void)
188{
189	bus_for_each_dev(&tee_bus_type, NULL, NULL,
190			 __optee_unregister_device);
191}
192