xref: /openbmc/linux/drivers/tee/optee/core.c (revision ee8ec048)
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 <linux/workqueue.h>
19 #include "optee_private.h"
20 
21 int optee_pool_op_alloc_helper(struct tee_shm_pool_mgr *poolm,
22 			       struct tee_shm *shm, size_t size,
23 			       int (*shm_register)(struct tee_context *ctx,
24 						   struct tee_shm *shm,
25 						   struct page **pages,
26 						   size_t num_pages,
27 						   unsigned long start))
28 {
29 	unsigned int order = get_order(size);
30 	struct page *page;
31 	int rc = 0;
32 
33 	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
34 	if (!page)
35 		return -ENOMEM;
36 
37 	shm->kaddr = page_address(page);
38 	shm->paddr = page_to_phys(page);
39 	shm->size = PAGE_SIZE << order;
40 
41 	if (shm_register) {
42 		unsigned int nr_pages = 1 << order, i;
43 		struct page **pages;
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] = page;
53 			page++;
54 		}
55 
56 		shm->flags |= TEE_SHM_REGISTER;
57 		rc = shm_register(shm->ctx, shm, pages, nr_pages,
58 				  (unsigned long)shm->kaddr);
59 		kfree(pages);
60 		if (rc)
61 			goto err;
62 	}
63 
64 	return 0;
65 
66 err:
67 	__free_pages(page, order);
68 	return rc;
69 }
70 
71 static void optee_bus_scan(struct work_struct *work)
72 {
73 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
74 }
75 
76 int optee_open(struct tee_context *ctx, bool cap_memref_null)
77 {
78 	struct optee_context_data *ctxdata;
79 	struct tee_device *teedev = ctx->teedev;
80 	struct optee *optee = tee_get_drvdata(teedev);
81 
82 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
83 	if (!ctxdata)
84 		return -ENOMEM;
85 
86 	if (teedev == optee->supp_teedev) {
87 		bool busy = true;
88 
89 		mutex_lock(&optee->supp.mutex);
90 		if (!optee->supp.ctx) {
91 			busy = false;
92 			optee->supp.ctx = ctx;
93 		}
94 		mutex_unlock(&optee->supp.mutex);
95 		if (busy) {
96 			kfree(ctxdata);
97 			return -EBUSY;
98 		}
99 
100 		if (!optee->scan_bus_done) {
101 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
102 			optee->scan_bus_wq = create_workqueue("optee_bus_scan");
103 			if (!optee->scan_bus_wq) {
104 				kfree(ctxdata);
105 				return -ECHILD;
106 			}
107 			queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
108 			optee->scan_bus_done = true;
109 		}
110 	}
111 	mutex_init(&ctxdata->mutex);
112 	INIT_LIST_HEAD(&ctxdata->sess_list);
113 
114 	ctx->cap_memref_null = cap_memref_null;
115 	ctx->data = ctxdata;
116 	return 0;
117 }
118 
119 static void optee_release_helper(struct tee_context *ctx,
120 				 int (*close_session)(struct tee_context *ctx,
121 						      u32 session))
122 {
123 	struct optee_context_data *ctxdata = ctx->data;
124 	struct optee_session *sess;
125 	struct optee_session *sess_tmp;
126 
127 	if (!ctxdata)
128 		return;
129 
130 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
131 				 list_node) {
132 		list_del(&sess->list_node);
133 		close_session(ctx, sess->session_id);
134 		kfree(sess);
135 	}
136 	kfree(ctxdata);
137 	ctx->data = NULL;
138 }
139 
140 void optee_release(struct tee_context *ctx)
141 {
142 	optee_release_helper(ctx, optee_close_session_helper);
143 }
144 
145 void optee_release_supp(struct tee_context *ctx)
146 {
147 	struct optee *optee = tee_get_drvdata(ctx->teedev);
148 
149 	optee_release_helper(ctx, optee_close_session_helper);
150 	if (optee->scan_bus_wq) {
151 		destroy_workqueue(optee->scan_bus_wq);
152 		optee->scan_bus_wq = NULL;
153 	}
154 	optee_supp_release(&optee->supp);
155 }
156 
157 void optee_remove_common(struct optee *optee)
158 {
159 	/* Unregister OP-TEE specific client devices on TEE bus */
160 	optee_unregister_devices();
161 
162 	/*
163 	 * The two devices have to be unregistered before we can free the
164 	 * other resources.
165 	 */
166 	tee_device_unregister(optee->supp_teedev);
167 	tee_device_unregister(optee->teedev);
168 
169 	tee_shm_pool_free(optee->pool);
170 	optee_wait_queue_exit(&optee->wait_queue);
171 	optee_supp_uninit(&optee->supp);
172 	mutex_destroy(&optee->call_queue.mutex);
173 }
174 
175 static int smc_abi_rc;
176 static int ffa_abi_rc;
177 
178 static int optee_core_init(void)
179 {
180 	/*
181 	 * The kernel may have crashed at the same time that all available
182 	 * secure world threads were suspended and we cannot reschedule the
183 	 * suspended threads without access to the crashed kernel's wait_queue.
184 	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
185 	 * kdump kernel.
186 	 */
187 	if (is_kdump_kernel())
188 		return -ENODEV;
189 
190 	smc_abi_rc = optee_smc_abi_register();
191 	ffa_abi_rc = optee_ffa_abi_register();
192 
193 	/* If both failed there's no point with this module */
194 	if (smc_abi_rc && ffa_abi_rc)
195 		return smc_abi_rc;
196 	return 0;
197 }
198 module_init(optee_core_init);
199 
200 static void optee_core_exit(void)
201 {
202 	if (!smc_abi_rc)
203 		optee_smc_abi_unregister();
204 	if (!ffa_abi_rc)
205 		optee_ffa_abi_unregister();
206 }
207 module_exit(optee_core_exit);
208 
209 MODULE_AUTHOR("Linaro");
210 MODULE_DESCRIPTION("OP-TEE driver");
211 MODULE_VERSION("1.0");
212 MODULE_LICENSE("GPL v2");
213 MODULE_ALIAS("platform:optee");
214