xref: /linux/drivers/tee/optee/core.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015-2021, Linaro Limited
4  * Copyright (c) 2016, EPAM Systems
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/crash_dump.h>
10 #include <linux/errno.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/rpmb.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/tee_core.h>
17 #include <linux/types.h>
18 #include "optee_private.h"
19 
20 struct blocking_notifier_head optee_rpmb_intf_added =
21 	BLOCKING_NOTIFIER_INIT(optee_rpmb_intf_added);
22 
23 static int rpmb_add_dev(struct device *dev)
24 {
25 	blocking_notifier_call_chain(&optee_rpmb_intf_added, 0,
26 				     to_rpmb_dev(dev));
27 
28 	return 0;
29 }
30 
31 static struct class_interface rpmb_class_intf = {
32 	.add_dev = rpmb_add_dev,
33 };
34 
35 void optee_bus_scan_rpmb(struct work_struct *work)
36 {
37 	struct optee *optee = container_of(work, struct optee,
38 					   rpmb_scan_bus_work);
39 	int ret;
40 
41 	if (!optee->rpmb_scan_bus_done) {
42 		ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);
43 		optee->rpmb_scan_bus_done = !ret;
44 		if (ret && ret != -ENODEV)
45 			pr_info("Scanning for RPMB device: ret %d\n", ret);
46 	}
47 }
48 
49 int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action,
50 			 void *data)
51 {
52 	struct optee *optee = container_of(intf, struct optee, rpmb_intf);
53 
54 	schedule_work(&optee->rpmb_scan_bus_work);
55 
56 	return 0;
57 }
58 
59 static void optee_bus_scan(struct work_struct *work)
60 {
61 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
62 }
63 
64 static ssize_t rpmb_routing_model_show(struct device *dev,
65 				       struct device_attribute *attr, char *buf)
66 {
67 	struct optee *optee = dev_get_drvdata(dev);
68 	const char *s;
69 
70 	if (optee->in_kernel_rpmb_routing)
71 		s = "kernel";
72 	else
73 		s = "user";
74 
75 	return scnprintf(buf, PAGE_SIZE, "%s\n", s);
76 }
77 static DEVICE_ATTR_RO(rpmb_routing_model);
78 
79 static struct attribute *optee_dev_attrs[] = {
80 	&dev_attr_rpmb_routing_model.attr,
81 	NULL
82 };
83 
84 ATTRIBUTE_GROUPS(optee_dev);
85 
86 void optee_set_dev_group(struct optee *optee)
87 {
88 	tee_device_set_dev_groups(optee->teedev, optee_dev_groups);
89 	tee_device_set_dev_groups(optee->supp_teedev, optee_dev_groups);
90 }
91 
92 int optee_open(struct tee_context *ctx, bool cap_memref_null)
93 {
94 	struct optee_context_data *ctxdata;
95 	struct tee_device *teedev = ctx->teedev;
96 	struct optee *optee = tee_get_drvdata(teedev);
97 
98 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
99 	if (!ctxdata)
100 		return -ENOMEM;
101 
102 	if (teedev == optee->supp_teedev) {
103 		bool busy = true;
104 
105 		mutex_lock(&optee->supp.mutex);
106 		if (!optee->supp.ctx) {
107 			busy = false;
108 			optee->supp.ctx = ctx;
109 		}
110 		mutex_unlock(&optee->supp.mutex);
111 		if (busy) {
112 			kfree(ctxdata);
113 			return -EBUSY;
114 		}
115 
116 		if (!optee->scan_bus_done) {
117 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
118 			schedule_work(&optee->scan_bus_work);
119 			optee->scan_bus_done = true;
120 		}
121 	}
122 	mutex_init(&ctxdata->mutex);
123 	INIT_LIST_HEAD(&ctxdata->sess_list);
124 
125 	ctx->cap_memref_null = cap_memref_null;
126 	ctx->data = ctxdata;
127 	return 0;
128 }
129 
130 static void optee_release_helper(struct tee_context *ctx,
131 				 int (*close_session)(struct tee_context *ctx,
132 						      u32 session,
133 						      bool system_thread))
134 {
135 	struct optee_context_data *ctxdata = ctx->data;
136 	struct optee_session *sess;
137 	struct optee_session *sess_tmp;
138 
139 	if (!ctxdata)
140 		return;
141 
142 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
143 				 list_node) {
144 		list_del(&sess->list_node);
145 		close_session(ctx, sess->session_id, sess->use_sys_thread);
146 		kfree(sess);
147 	}
148 	kfree(ctxdata);
149 	ctx->data = NULL;
150 }
151 
152 void optee_release(struct tee_context *ctx)
153 {
154 	optee_release_helper(ctx, optee_close_session_helper);
155 }
156 
157 void optee_release_supp(struct tee_context *ctx)
158 {
159 	struct optee *optee = tee_get_drvdata(ctx->teedev);
160 
161 	optee_release_helper(ctx, optee_close_session_helper);
162 
163 	optee_supp_release(&optee->supp);
164 }
165 
166 void optee_remove_common(struct optee *optee)
167 {
168 	blocking_notifier_chain_unregister(&optee_rpmb_intf_added,
169 					   &optee->rpmb_intf);
170 	cancel_work_sync(&optee->rpmb_scan_bus_work);
171 	/* Unregister OP-TEE specific client devices on TEE bus */
172 	optee_unregister_devices();
173 
174 	optee_notif_uninit(optee);
175 	optee_shm_arg_cache_uninit(optee);
176 	teedev_close_context(optee->ctx);
177 	/*
178 	 * The two devices have to be unregistered before we can free the
179 	 * other resources.
180 	 */
181 	tee_device_unregister(optee->supp_teedev);
182 	tee_device_unregister(optee->teedev);
183 
184 	tee_shm_pool_free(optee->pool);
185 	optee_supp_uninit(&optee->supp);
186 	mutex_destroy(&optee->call_queue.mutex);
187 	rpmb_dev_put(optee->rpmb_dev);
188 	mutex_destroy(&optee->rpmb_dev_mutex);
189 }
190 
191 static int smc_abi_rc;
192 static int ffa_abi_rc;
193 static bool intf_is_regged;
194 
195 static int __init optee_core_init(void)
196 {
197 	int rc;
198 
199 	/*
200 	 * The kernel may have crashed at the same time that all available
201 	 * secure world threads were suspended and we cannot reschedule the
202 	 * suspended threads without access to the crashed kernel's wait_queue.
203 	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
204 	 * kdump kernel.
205 	 */
206 	if (is_kdump_kernel())
207 		return -ENODEV;
208 
209 	if (IS_REACHABLE(CONFIG_RPMB)) {
210 		rc = rpmb_interface_register(&rpmb_class_intf);
211 		if (rc)
212 			return rc;
213 		intf_is_regged = true;
214 	}
215 
216 	smc_abi_rc = optee_smc_abi_register();
217 	ffa_abi_rc = optee_ffa_abi_register();
218 
219 	/* If both failed there's no point with this module */
220 	if (smc_abi_rc && ffa_abi_rc) {
221 		if (IS_REACHABLE(CONFIG_RPMB)) {
222 			rpmb_interface_unregister(&rpmb_class_intf);
223 			intf_is_regged = false;
224 		}
225 		return smc_abi_rc;
226 	}
227 
228 	return 0;
229 }
230 module_init(optee_core_init);
231 
232 static void __exit optee_core_exit(void)
233 {
234 	if (IS_REACHABLE(CONFIG_RPMB) && intf_is_regged) {
235 		rpmb_interface_unregister(&rpmb_class_intf);
236 		intf_is_regged = false;
237 	}
238 
239 	if (!smc_abi_rc)
240 		optee_smc_abi_unregister();
241 	if (!ffa_abi_rc)
242 		optee_ffa_abi_unregister();
243 }
244 module_exit(optee_core_exit);
245 
246 MODULE_AUTHOR("Linaro");
247 MODULE_DESCRIPTION("OP-TEE driver");
248 MODULE_VERSION("1.0");
249 MODULE_LICENSE("GPL v2");
250 MODULE_ALIAS("platform:optee");
251