xref: /linux/drivers/tee/optee/core.c (revision 55a42f78ffd386e01a5404419f8c5ded7db70a21)
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 int optee_set_dma_mask(struct optee *optee, u_int pa_width)
60 {
61 	u64 mask = DMA_BIT_MASK(min(64, pa_width));
62 
63 	return dma_coerce_mask_and_coherent(&optee->teedev->dev, mask);
64 }
65 
66 static void optee_bus_scan(struct work_struct *work)
67 {
68 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
69 }
70 
71 static ssize_t rpmb_routing_model_show(struct device *dev,
72 				       struct device_attribute *attr, char *buf)
73 {
74 	struct optee *optee = dev_get_drvdata(dev);
75 	const char *s;
76 
77 	if (optee->in_kernel_rpmb_routing)
78 		s = "kernel";
79 	else
80 		s = "user";
81 
82 	return sysfs_emit(buf, "%s\n", s);
83 }
84 static DEVICE_ATTR_RO(rpmb_routing_model);
85 
86 static struct attribute *optee_dev_attrs[] = {
87 	&dev_attr_rpmb_routing_model.attr,
88 	NULL
89 };
90 
91 ATTRIBUTE_GROUPS(optee_dev);
92 
93 void optee_set_dev_group(struct optee *optee)
94 {
95 	tee_device_set_dev_groups(optee->teedev, optee_dev_groups);
96 	tee_device_set_dev_groups(optee->supp_teedev, optee_dev_groups);
97 }
98 
99 int optee_open(struct tee_context *ctx, bool cap_memref_null)
100 {
101 	struct optee_context_data *ctxdata;
102 	struct tee_device *teedev = ctx->teedev;
103 	struct optee *optee = tee_get_drvdata(teedev);
104 
105 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
106 	if (!ctxdata)
107 		return -ENOMEM;
108 
109 	if (teedev == optee->supp_teedev) {
110 		bool busy = true;
111 
112 		mutex_lock(&optee->supp.mutex);
113 		if (!optee->supp.ctx) {
114 			busy = false;
115 			optee->supp.ctx = ctx;
116 		}
117 		mutex_unlock(&optee->supp.mutex);
118 		if (busy) {
119 			kfree(ctxdata);
120 			return -EBUSY;
121 		}
122 
123 		if (!optee->scan_bus_done) {
124 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
125 			schedule_work(&optee->scan_bus_work);
126 			optee->scan_bus_done = true;
127 		}
128 	}
129 	mutex_init(&ctxdata->mutex);
130 	INIT_LIST_HEAD(&ctxdata->sess_list);
131 
132 	ctx->cap_memref_null = cap_memref_null;
133 	ctx->data = ctxdata;
134 	return 0;
135 }
136 
137 static void optee_release_helper(struct tee_context *ctx,
138 				 int (*close_session)(struct tee_context *ctx,
139 						      u32 session,
140 						      bool system_thread))
141 {
142 	struct optee_context_data *ctxdata = ctx->data;
143 	struct optee_session *sess;
144 	struct optee_session *sess_tmp;
145 
146 	if (!ctxdata)
147 		return;
148 
149 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
150 				 list_node) {
151 		list_del(&sess->list_node);
152 		close_session(ctx, sess->session_id, sess->use_sys_thread);
153 		kfree(sess);
154 	}
155 	kfree(ctxdata);
156 	ctx->data = NULL;
157 }
158 
159 void optee_release(struct tee_context *ctx)
160 {
161 	optee_release_helper(ctx, optee_close_session_helper);
162 }
163 
164 void optee_release_supp(struct tee_context *ctx)
165 {
166 	struct optee *optee = tee_get_drvdata(ctx->teedev);
167 
168 	optee_release_helper(ctx, optee_close_session_helper);
169 
170 	optee_supp_release(&optee->supp);
171 }
172 
173 void optee_remove_common(struct optee *optee)
174 {
175 	blocking_notifier_chain_unregister(&optee_rpmb_intf_added,
176 					   &optee->rpmb_intf);
177 	cancel_work_sync(&optee->rpmb_scan_bus_work);
178 	/* Unregister OP-TEE specific client devices on TEE bus */
179 	optee_unregister_devices();
180 
181 	optee_notif_uninit(optee);
182 	optee_shm_arg_cache_uninit(optee);
183 	teedev_close_context(optee->ctx);
184 	/*
185 	 * The two devices have to be unregistered before we can free the
186 	 * other resources.
187 	 */
188 	tee_device_unregister(optee->supp_teedev);
189 	tee_device_unregister(optee->teedev);
190 
191 	tee_shm_pool_free(optee->pool);
192 	optee_supp_uninit(&optee->supp);
193 	mutex_destroy(&optee->call_queue.mutex);
194 	rpmb_dev_put(optee->rpmb_dev);
195 	mutex_destroy(&optee->rpmb_dev_mutex);
196 }
197 
198 static int smc_abi_rc;
199 static int ffa_abi_rc;
200 static bool intf_is_regged;
201 
202 static int __init optee_core_init(void)
203 {
204 	int rc;
205 
206 	/*
207 	 * The kernel may have crashed at the same time that all available
208 	 * secure world threads were suspended and we cannot reschedule the
209 	 * suspended threads without access to the crashed kernel's wait_queue.
210 	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
211 	 * kdump kernel.
212 	 */
213 	if (is_kdump_kernel())
214 		return -ENODEV;
215 
216 	if (IS_REACHABLE(CONFIG_RPMB)) {
217 		rc = rpmb_interface_register(&rpmb_class_intf);
218 		if (rc)
219 			return rc;
220 		intf_is_regged = true;
221 	}
222 
223 	smc_abi_rc = optee_smc_abi_register();
224 	ffa_abi_rc = optee_ffa_abi_register();
225 
226 	/* If both failed there's no point with this module */
227 	if (smc_abi_rc && ffa_abi_rc) {
228 		if (IS_REACHABLE(CONFIG_RPMB)) {
229 			rpmb_interface_unregister(&rpmb_class_intf);
230 			intf_is_regged = false;
231 		}
232 		return smc_abi_rc;
233 	}
234 
235 	return 0;
236 }
237 module_init(optee_core_init);
238 
239 static void __exit optee_core_exit(void)
240 {
241 	if (IS_REACHABLE(CONFIG_RPMB) && intf_is_regged) {
242 		rpmb_interface_unregister(&rpmb_class_intf);
243 		intf_is_regged = false;
244 	}
245 
246 	if (!smc_abi_rc)
247 		optee_smc_abi_unregister();
248 	if (!ffa_abi_rc)
249 		optee_ffa_abi_unregister();
250 }
251 module_exit(optee_core_exit);
252 
253 MODULE_AUTHOR("Linaro");
254 MODULE_DESCRIPTION("OP-TEE driver");
255 MODULE_VERSION("1.0");
256 MODULE_LICENSE("GPL v2");
257 MODULE_ALIAS("platform:optee");
258