xref: /linux/drivers/tee/optee/core.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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/mm.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/tee_drv.h>
17 #include <linux/types.h>
18 #include "optee_private.h"
19 
20 int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
21 			       size_t size, size_t align,
22 			       int (*shm_register)(struct tee_context *ctx,
23 						   struct tee_shm *shm,
24 						   struct page **pages,
25 						   size_t num_pages,
26 						   unsigned long start))
27 {
28 	size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE;
29 	struct page **pages;
30 	unsigned int i;
31 	int rc = 0;
32 
33 	/*
34 	 * Ignore alignment since this is already going to be page aligned
35 	 * and there's no need for any larger alignment.
36 	 */
37 	shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
38 				       GFP_KERNEL | __GFP_ZERO);
39 	if (!shm->kaddr)
40 		return -ENOMEM;
41 
42 	shm->paddr = virt_to_phys(shm->kaddr);
43 	shm->size = nr_pages * PAGE_SIZE;
44 
45 	pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
46 	if (!pages) {
47 		rc = -ENOMEM;
48 		goto err;
49 	}
50 
51 	for (i = 0; i < nr_pages; i++)
52 		pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE);
53 
54 	shm->pages = pages;
55 	shm->num_pages = nr_pages;
56 
57 	if (shm_register) {
58 		rc = shm_register(shm->ctx, shm, pages, nr_pages,
59 				  (unsigned long)shm->kaddr);
60 		if (rc)
61 			goto err;
62 	}
63 
64 	return 0;
65 err:
66 	free_pages_exact(shm->kaddr, shm->size);
67 	shm->kaddr = NULL;
68 	return rc;
69 }
70 
71 void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
72 			       int (*shm_unregister)(struct tee_context *ctx,
73 						     struct tee_shm *shm))
74 {
75 	if (shm_unregister)
76 		shm_unregister(shm->ctx, shm);
77 	free_pages_exact(shm->kaddr, shm->size);
78 	shm->kaddr = NULL;
79 	kfree(shm->pages);
80 	shm->pages = NULL;
81 }
82 
83 static void optee_bus_scan(struct work_struct *work)
84 {
85 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
86 }
87 
88 int optee_open(struct tee_context *ctx, bool cap_memref_null)
89 {
90 	struct optee_context_data *ctxdata;
91 	struct tee_device *teedev = ctx->teedev;
92 	struct optee *optee = tee_get_drvdata(teedev);
93 
94 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
95 	if (!ctxdata)
96 		return -ENOMEM;
97 
98 	if (teedev == optee->supp_teedev) {
99 		bool busy = true;
100 
101 		mutex_lock(&optee->supp.mutex);
102 		if (!optee->supp.ctx) {
103 			busy = false;
104 			optee->supp.ctx = ctx;
105 		}
106 		mutex_unlock(&optee->supp.mutex);
107 		if (busy) {
108 			kfree(ctxdata);
109 			return -EBUSY;
110 		}
111 
112 		if (!optee->scan_bus_done) {
113 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
114 			schedule_work(&optee->scan_bus_work);
115 			optee->scan_bus_done = true;
116 		}
117 	}
118 	mutex_init(&ctxdata->mutex);
119 	INIT_LIST_HEAD(&ctxdata->sess_list);
120 
121 	ctx->cap_memref_null = cap_memref_null;
122 	ctx->data = ctxdata;
123 	return 0;
124 }
125 
126 static void optee_release_helper(struct tee_context *ctx,
127 				 int (*close_session)(struct tee_context *ctx,
128 						      u32 session,
129 						      bool system_thread))
130 {
131 	struct optee_context_data *ctxdata = ctx->data;
132 	struct optee_session *sess;
133 	struct optee_session *sess_tmp;
134 
135 	if (!ctxdata)
136 		return;
137 
138 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
139 				 list_node) {
140 		list_del(&sess->list_node);
141 		close_session(ctx, sess->session_id, sess->use_sys_thread);
142 		kfree(sess);
143 	}
144 	kfree(ctxdata);
145 	ctx->data = NULL;
146 }
147 
148 void optee_release(struct tee_context *ctx)
149 {
150 	optee_release_helper(ctx, optee_close_session_helper);
151 }
152 
153 void optee_release_supp(struct tee_context *ctx)
154 {
155 	struct optee *optee = tee_get_drvdata(ctx->teedev);
156 
157 	optee_release_helper(ctx, optee_close_session_helper);
158 
159 	optee_supp_release(&optee->supp);
160 }
161 
162 void optee_remove_common(struct optee *optee)
163 {
164 	/* Unregister OP-TEE specific client devices on TEE bus */
165 	optee_unregister_devices();
166 
167 	optee_notif_uninit(optee);
168 	optee_shm_arg_cache_uninit(optee);
169 	teedev_close_context(optee->ctx);
170 	/*
171 	 * The two devices have to be unregistered before we can free the
172 	 * other resources.
173 	 */
174 	tee_device_unregister(optee->supp_teedev);
175 	tee_device_unregister(optee->teedev);
176 
177 	tee_shm_pool_free(optee->pool);
178 	optee_supp_uninit(&optee->supp);
179 	mutex_destroy(&optee->call_queue.mutex);
180 }
181 
182 static int smc_abi_rc;
183 static int ffa_abi_rc;
184 
185 static int __init optee_core_init(void)
186 {
187 	/*
188 	 * The kernel may have crashed at the same time that all available
189 	 * secure world threads were suspended and we cannot reschedule the
190 	 * suspended threads without access to the crashed kernel's wait_queue.
191 	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
192 	 * kdump kernel.
193 	 */
194 	if (is_kdump_kernel())
195 		return -ENODEV;
196 
197 	smc_abi_rc = optee_smc_abi_register();
198 	ffa_abi_rc = optee_ffa_abi_register();
199 
200 	/* If both failed there's no point with this module */
201 	if (smc_abi_rc && ffa_abi_rc)
202 		return smc_abi_rc;
203 	return 0;
204 }
205 module_init(optee_core_init);
206 
207 static void __exit optee_core_exit(void)
208 {
209 	if (!smc_abi_rc)
210 		optee_smc_abi_unregister();
211 	if (!ffa_abi_rc)
212 		optee_ffa_abi_unregister();
213 }
214 module_exit(optee_core_exit);
215 
216 MODULE_AUTHOR("Linaro");
217 MODULE_DESCRIPTION("OP-TEE driver");
218 MODULE_VERSION("1.0");
219 MODULE_LICENSE("GPL v2");
220 MODULE_ALIAS("platform:optee");
221