xref: /linux/drivers/tee/amdtee/core.c (revision 84a1e6179bd24dc10e47f6fa2b36f0ed345e68d8)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2019 Advanced Micro Devices, Inc.
4  */
5 
6  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/errno.h>
9 #include <linux/device.h>
10 #include <linux/firmware.h>
11 #include <linux/io.h>
12 #include <linux/mm.h>
13 #include <linux/module.h>
14 #include <linux/psp-tee.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <linux/tee_core.h>
18 #include <linux/types.h>
19 #include <linux/uaccess.h>
20 
21 #include "amdtee_private.h"
22 
23 static struct amdtee_driver_data *drv_data;
24 static DEFINE_MUTEX(session_list_mutex);
25 
26 static void amdtee_get_version(struct tee_device *teedev,
27 			       struct tee_ioctl_version_data *vers)
28 {
29 	struct tee_ioctl_version_data v = {
30 		.impl_id = TEE_IMPL_ID_AMDTEE,
31 		.impl_caps = 0,
32 		.gen_caps = TEE_GEN_CAP_GP,
33 	};
34 	*vers = v;
35 }
36 
37 static int amdtee_open(struct tee_context *ctx)
38 {
39 	struct amdtee_context_data *ctxdata;
40 
41 	ctxdata = kzalloc_obj(*ctxdata);
42 	if (!ctxdata)
43 		return -ENOMEM;
44 
45 	INIT_LIST_HEAD(&ctxdata->sess_list);
46 
47 	ctx->data = ctxdata;
48 	return 0;
49 }
50 
51 static void release_session(struct amdtee_session *sess)
52 {
53 	int i;
54 
55 	/* Close any open session */
56 	for (i = 0; i < TEE_NUM_SESSIONS; ++i) {
57 		/* Check if session entry 'i' is valid */
58 		if (!test_bit(i, sess->sess_mask))
59 			continue;
60 
61 		handle_close_session(sess->ta_handle, sess->session_info[i]);
62 		handle_unload_ta(sess->ta_handle);
63 	}
64 
65 	kfree(sess);
66 }
67 
68 static void amdtee_release(struct tee_context *ctx)
69 {
70 	struct amdtee_context_data *ctxdata = ctx->data;
71 
72 	if (!ctxdata)
73 		return;
74 
75 	while (true) {
76 		struct amdtee_session *sess;
77 
78 		sess = list_first_entry_or_null(&ctxdata->sess_list,
79 						struct amdtee_session,
80 						list_node);
81 
82 		if (!sess)
83 			break;
84 
85 		list_del(&sess->list_node);
86 		release_session(sess);
87 	}
88 	kfree(ctxdata);
89 
90 	ctx->data = NULL;
91 }
92 
93 /**
94  * alloc_session() - Allocate a session structure
95  * @ctxdata:    TEE Context data structure
96  * @session:    Session ID for which 'struct amdtee_session' structure is to be
97  *              allocated.
98  *
99  * Scans the TEE context's session list to check if TA is already loaded in to
100  * TEE. If yes, returns the 'session' structure for that TA. Else allocates,
101  * initializes a new 'session' structure and adds it to context's session list.
102  *
103  * The caller must hold a mutex.
104  *
105  * Returns:
106  * 'struct amdtee_session *' on success and NULL on failure.
107  */
108 static struct amdtee_session *alloc_session(struct amdtee_context_data *ctxdata,
109 					    u32 session)
110 {
111 	struct amdtee_session *sess;
112 	u32 ta_handle = get_ta_handle(session);
113 
114 	/* Scan session list to check if TA is already loaded in to TEE */
115 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
116 		if (sess->ta_handle == ta_handle) {
117 			kref_get(&sess->refcount);
118 			return sess;
119 		}
120 
121 	/* Allocate a new session and add to list */
122 	sess = kzalloc_obj(*sess);
123 	if (sess) {
124 		sess->ta_handle = ta_handle;
125 		kref_init(&sess->refcount);
126 		spin_lock_init(&sess->lock);
127 		list_add(&sess->list_node, &ctxdata->sess_list);
128 	}
129 
130 	return sess;
131 }
132 
133 /* Requires mutex to be held */
134 static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
135 					   u32 session)
136 {
137 	u32 ta_handle = get_ta_handle(session);
138 	u32 index = get_session_index(session);
139 	struct amdtee_session *sess;
140 
141 	if (index >= TEE_NUM_SESSIONS)
142 		return NULL;
143 
144 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
145 		if (ta_handle == sess->ta_handle &&
146 		    test_bit(index, sess->sess_mask))
147 			return sess;
148 
149 	return NULL;
150 }
151 
152 static DEFINE_MUTEX(drv_mutex);
153 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
154 			  size_t *ta_size)
155 {
156 	const struct firmware *fw;
157 	char fw_name[TA_PATH_MAX];
158 	struct {
159 		u32 lo;
160 		u16 mid;
161 		u16 hi_ver;
162 		u8 seq_n[8];
163 	} *uuid = ptr;
164 	int n, rc = 0;
165 
166 	n = snprintf(fw_name, TA_PATH_MAX,
167 		     "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
168 		     TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
169 		     uuid->seq_n[0], uuid->seq_n[1],
170 		     uuid->seq_n[2], uuid->seq_n[3],
171 		     uuid->seq_n[4], uuid->seq_n[5],
172 		     uuid->seq_n[6], uuid->seq_n[7]);
173 	if (n < 0 || n >= TA_PATH_MAX) {
174 		pr_err("failed to get firmware name\n");
175 		return -EINVAL;
176 	}
177 
178 	mutex_lock(&drv_mutex);
179 	n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
180 	if (n) {
181 		pr_err("failed to load firmware %s\n", fw_name);
182 		rc = -ENOMEM;
183 		goto unlock;
184 	}
185 
186 	*ta_size = roundup(fw->size, PAGE_SIZE);
187 	*ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
188 	if (!*ta) {
189 		pr_err("%s: get_free_pages failed\n", __func__);
190 		rc = -ENOMEM;
191 		goto rel_fw;
192 	}
193 
194 	memcpy(*ta, fw->data, fw->size);
195 rel_fw:
196 	release_firmware(fw);
197 unlock:
198 	mutex_unlock(&drv_mutex);
199 	return rc;
200 }
201 
202 /* mutex must be held by caller */
203 static void destroy_session(struct kref *ref)
204 {
205 	struct amdtee_session *sess = container_of(ref, struct amdtee_session,
206 						   refcount);
207 
208 	list_del(&sess->list_node);
209 	mutex_unlock(&session_list_mutex);
210 	kfree(sess);
211 }
212 
213 int amdtee_open_session(struct tee_context *ctx,
214 			struct tee_ioctl_open_session_arg *arg,
215 			struct tee_param *param)
216 {
217 	struct amdtee_context_data *ctxdata = ctx->data;
218 	struct amdtee_session *sess = NULL;
219 	u32 session_info, ta_handle;
220 	size_t ta_size;
221 	int rc, i;
222 	void *ta;
223 
224 	if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
225 		pr_err("unsupported client login method\n");
226 		return -EINVAL;
227 	}
228 
229 	rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
230 	if (rc) {
231 		pr_err("failed to copy TA binary\n");
232 		return rc;
233 	}
234 
235 	/* Load the TA binary into TEE environment */
236 	handle_load_ta(ta, ta_size, arg);
237 	if (arg->ret != TEEC_SUCCESS)
238 		goto out;
239 
240 	ta_handle = get_ta_handle(arg->session);
241 
242 	mutex_lock(&session_list_mutex);
243 	sess = alloc_session(ctxdata, arg->session);
244 	mutex_unlock(&session_list_mutex);
245 
246 	if (!sess) {
247 		handle_unload_ta(ta_handle);
248 		rc = -ENOMEM;
249 		goto out;
250 	}
251 
252 	/* Open session with loaded TA */
253 	handle_open_session(arg, &session_info, param);
254 	if (arg->ret != TEEC_SUCCESS) {
255 		pr_err("open_session failed %d\n", arg->ret);
256 		handle_unload_ta(ta_handle);
257 		kref_put_mutex(&sess->refcount, destroy_session,
258 			       &session_list_mutex);
259 		goto out;
260 	}
261 
262 	/* Find an empty session index for the given TA */
263 	spin_lock(&sess->lock);
264 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
265 	if (i < TEE_NUM_SESSIONS) {
266 		sess->session_info[i] = session_info;
267 		set_session_id(ta_handle, i, &arg->session);
268 		set_bit(i, sess->sess_mask);
269 	}
270 	spin_unlock(&sess->lock);
271 
272 	if (i >= TEE_NUM_SESSIONS) {
273 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
274 		handle_close_session(ta_handle, session_info);
275 		handle_unload_ta(ta_handle);
276 		kref_put_mutex(&sess->refcount, destroy_session,
277 			       &session_list_mutex);
278 		rc = -ENOMEM;
279 		goto out;
280 	}
281 
282 out:
283 	free_pages((u64)ta, get_order(ta_size));
284 	return rc;
285 }
286 
287 int amdtee_close_session(struct tee_context *ctx, u32 session)
288 {
289 	struct amdtee_context_data *ctxdata = ctx->data;
290 	u32 i, ta_handle, session_info;
291 	struct amdtee_session *sess;
292 
293 	pr_debug("%s: sid = 0x%x\n", __func__, session);
294 
295 	/*
296 	 * Check that the session is valid and clear the session
297 	 * usage bit
298 	 */
299 	mutex_lock(&session_list_mutex);
300 	sess = find_session(ctxdata, session);
301 	if (sess) {
302 		ta_handle = get_ta_handle(session);
303 		i = get_session_index(session);
304 		session_info = sess->session_info[i];
305 		spin_lock(&sess->lock);
306 		clear_bit(i, sess->sess_mask);
307 		spin_unlock(&sess->lock);
308 	}
309 	mutex_unlock(&session_list_mutex);
310 
311 	if (!sess)
312 		return -EINVAL;
313 
314 	/* Close the session */
315 	handle_close_session(ta_handle, session_info);
316 	handle_unload_ta(ta_handle);
317 
318 	kref_put_mutex(&sess->refcount, destroy_session, &session_list_mutex);
319 
320 	return 0;
321 }
322 
323 int amdtee_map_shmem(struct tee_shm *shm)
324 {
325 	struct shmem_desc shmem;
326 	int rc, count;
327 	u32 buf_id;
328 
329 	if (!shm)
330 		return -EINVAL;
331 
332 	count = 1;
333 	shmem.kaddr = shm->kaddr;
334 	shmem.size = shm->size;
335 
336 	/*
337 	 * Send a MAP command to TEE and get the corresponding
338 	 * buffer Id
339 	 */
340 	rc = handle_map_shmem(count, &shmem, &buf_id);
341 	if (rc) {
342 		pr_err("map_shmem failed: ret = %d\n", rc);
343 		return rc;
344 	}
345 
346 	shm->sec_world_id = buf_id;
347 
348 	pr_debug("buf_id :[%x] kaddr[%p]\n", buf_id, shm->kaddr);
349 
350 	return 0;
351 }
352 
353 void amdtee_unmap_shmem(struct tee_shm *shm)
354 {
355 	u32 buf_id;
356 
357 	if (!shm)
358 		return;
359 
360 	buf_id = (u32)shm->sec_world_id;
361 	handle_unmap_shmem(buf_id);
362 	shm->sec_world_id = 0;
363 }
364 
365 int amdtee_invoke_func(struct tee_context *ctx,
366 		       struct tee_ioctl_invoke_arg *arg,
367 		       struct tee_param *param)
368 {
369 	struct amdtee_context_data *ctxdata = ctx->data;
370 	struct amdtee_session *sess;
371 	u32 i, session_info;
372 
373 	/* Check that the session is valid */
374 	mutex_lock(&session_list_mutex);
375 	sess = find_session(ctxdata, arg->session);
376 	if (sess) {
377 		i = get_session_index(arg->session);
378 		session_info = sess->session_info[i];
379 	}
380 	mutex_unlock(&session_list_mutex);
381 
382 	if (!sess)
383 		return -EINVAL;
384 
385 	handle_invoke_cmd(arg, session_info, param);
386 
387 	return 0;
388 }
389 
390 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
391 {
392 	return -EINVAL;
393 }
394 
395 static const struct tee_driver_ops amdtee_ops = {
396 	.get_version = amdtee_get_version,
397 	.open = amdtee_open,
398 	.release = amdtee_release,
399 	.open_session = amdtee_open_session,
400 	.close_session = amdtee_close_session,
401 	.invoke_func = amdtee_invoke_func,
402 	.cancel_req = amdtee_cancel_req,
403 };
404 
405 static const struct tee_desc amdtee_desc = {
406 	.name = DRIVER_NAME "-clnt",
407 	.ops = &amdtee_ops,
408 	.owner = THIS_MODULE,
409 };
410 
411 static int __init amdtee_driver_init(void)
412 {
413 	struct tee_device *teedev;
414 	struct tee_shm_pool *pool;
415 	struct amdtee *amdtee;
416 	int rc;
417 
418 	rc = psp_check_tee_status();
419 	if (rc) {
420 		pr_err("tee not present\n");
421 		return rc;
422 	}
423 
424 	drv_data = kzalloc_obj(*drv_data);
425 	if (!drv_data)
426 		return -ENOMEM;
427 
428 	amdtee = kzalloc_obj(*amdtee);
429 	if (!amdtee) {
430 		rc = -ENOMEM;
431 		goto err_kfree_drv_data;
432 	}
433 
434 	pool = amdtee_config_shm();
435 	if (IS_ERR(pool)) {
436 		pr_err("shared pool configuration error\n");
437 		rc = PTR_ERR(pool);
438 		goto err_kfree_amdtee;
439 	}
440 
441 	teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
442 	if (IS_ERR(teedev)) {
443 		rc = PTR_ERR(teedev);
444 		goto err_free_pool;
445 	}
446 	amdtee->teedev = teedev;
447 
448 	rc = tee_device_register(amdtee->teedev);
449 	if (rc)
450 		goto err_device_unregister;
451 
452 	amdtee->pool = pool;
453 
454 	drv_data->amdtee = amdtee;
455 
456 	return 0;
457 
458 err_device_unregister:
459 	tee_device_unregister(amdtee->teedev);
460 
461 err_free_pool:
462 	tee_shm_pool_free(pool);
463 
464 err_kfree_amdtee:
465 	kfree(amdtee);
466 
467 err_kfree_drv_data:
468 	kfree(drv_data);
469 	drv_data = NULL;
470 
471 	pr_err("initialization failed\n");
472 	return rc;
473 }
474 module_init(amdtee_driver_init);
475 
476 static void __exit amdtee_driver_exit(void)
477 {
478 	struct amdtee *amdtee;
479 
480 	if (!drv_data || !drv_data->amdtee)
481 		return;
482 
483 	amdtee = drv_data->amdtee;
484 
485 	tee_device_unregister(amdtee->teedev);
486 	tee_shm_pool_free(amdtee->pool);
487 }
488 module_exit(amdtee_driver_exit);
489 
490 MODULE_AUTHOR(DRIVER_AUTHOR);
491 MODULE_DESCRIPTION("AMD-TEE driver");
492 MODULE_VERSION("1.0");
493 MODULE_LICENSE("Dual MIT/GPL");
494