xref: /linux/drivers/tee/amdtee/core.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2019 Advanced Micro Devices, Inc.
4  */
5 
6 #include <linux/errno.h>
7 #include <linux/io.h>
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/string.h>
11 #include <linux/device.h>
12 #include <linux/tee_drv.h>
13 #include <linux/types.h>
14 #include <linux/mm.h>
15 #include <linux/uaccess.h>
16 #include <linux/firmware.h>
17 #include "amdtee_private.h"
18 #include "../tee_private.h"
19 #include <linux/psp-tee.h>
20 
21 static struct amdtee_driver_data *drv_data;
22 static DEFINE_MUTEX(session_list_mutex);
23 
24 static void amdtee_get_version(struct tee_device *teedev,
25 			       struct tee_ioctl_version_data *vers)
26 {
27 	struct tee_ioctl_version_data v = {
28 		.impl_id = TEE_IMPL_ID_AMDTEE,
29 		.impl_caps = 0,
30 		.gen_caps = TEE_GEN_CAP_GP,
31 	};
32 	*vers = v;
33 }
34 
35 static int amdtee_open(struct tee_context *ctx)
36 {
37 	struct amdtee_context_data *ctxdata;
38 
39 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
40 	if (!ctxdata)
41 		return -ENOMEM;
42 
43 	INIT_LIST_HEAD(&ctxdata->sess_list);
44 	INIT_LIST_HEAD(&ctxdata->shm_list);
45 	mutex_init(&ctxdata->shm_mutex);
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 	}
63 
64 	/* Unload Trusted Application once all sessions are closed */
65 	handle_unload_ta(sess->ta_handle);
66 	kfree(sess);
67 }
68 
69 static void amdtee_release(struct tee_context *ctx)
70 {
71 	struct amdtee_context_data *ctxdata = ctx->data;
72 
73 	if (!ctxdata)
74 		return;
75 
76 	while (true) {
77 		struct amdtee_session *sess;
78 
79 		sess = list_first_entry_or_null(&ctxdata->sess_list,
80 						struct amdtee_session,
81 						list_node);
82 
83 		if (!sess)
84 			break;
85 
86 		list_del(&sess->list_node);
87 		release_session(sess);
88 	}
89 	mutex_destroy(&ctxdata->shm_mutex);
90 	kfree(ctxdata);
91 
92 	ctx->data = NULL;
93 }
94 
95 /**
96  * alloc_session() - Allocate a session structure
97  * @ctxdata:    TEE Context data structure
98  * @session:    Session ID for which 'struct amdtee_session' structure is to be
99  *              allocated.
100  *
101  * Scans the TEE context's session list to check if TA is already loaded in to
102  * TEE. If yes, returns the 'session' structure for that TA. Else allocates,
103  * initializes a new 'session' structure and adds it to context's session list.
104  *
105  * The caller must hold a mutex.
106  *
107  * Returns:
108  * 'struct amdtee_session *' on success and NULL on failure.
109  */
110 static struct amdtee_session *alloc_session(struct amdtee_context_data *ctxdata,
111 					    u32 session)
112 {
113 	struct amdtee_session *sess;
114 	u32 ta_handle = get_ta_handle(session);
115 
116 	/* Scan session list to check if TA is already loaded in to TEE */
117 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
118 		if (sess->ta_handle == ta_handle) {
119 			kref_get(&sess->refcount);
120 			return sess;
121 		}
122 
123 	/* Allocate a new session and add to list */
124 	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
125 	if (sess) {
126 		sess->ta_handle = ta_handle;
127 		kref_init(&sess->refcount);
128 		spin_lock_init(&sess->lock);
129 		list_add(&sess->list_node, &ctxdata->sess_list);
130 	}
131 
132 	return sess;
133 }
134 
135 /* Requires mutex to be held */
136 static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
137 					   u32 session)
138 {
139 	u32 ta_handle = get_ta_handle(session);
140 	u32 index = get_session_index(session);
141 	struct amdtee_session *sess;
142 
143 	if (index >= TEE_NUM_SESSIONS)
144 		return NULL;
145 
146 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
147 		if (ta_handle == sess->ta_handle &&
148 		    test_bit(index, sess->sess_mask))
149 			return sess;
150 
151 	return NULL;
152 }
153 
154 u32 get_buffer_id(struct tee_shm *shm)
155 {
156 	struct amdtee_context_data *ctxdata = shm->ctx->data;
157 	struct amdtee_shm_data *shmdata;
158 	u32 buf_id = 0;
159 
160 	mutex_lock(&ctxdata->shm_mutex);
161 	list_for_each_entry(shmdata, &ctxdata->shm_list, shm_node)
162 		if (shmdata->kaddr == shm->kaddr) {
163 			buf_id = shmdata->buf_id;
164 			break;
165 		}
166 	mutex_unlock(&ctxdata->shm_mutex);
167 
168 	return buf_id;
169 }
170 
171 static DEFINE_MUTEX(drv_mutex);
172 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
173 			  size_t *ta_size)
174 {
175 	const struct firmware *fw;
176 	char fw_name[TA_PATH_MAX];
177 	struct {
178 		u32 lo;
179 		u16 mid;
180 		u16 hi_ver;
181 		u8 seq_n[8];
182 	} *uuid = ptr;
183 	int n, rc = 0;
184 
185 	n = snprintf(fw_name, TA_PATH_MAX,
186 		     "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
187 		     TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
188 		     uuid->seq_n[0], uuid->seq_n[1],
189 		     uuid->seq_n[2], uuid->seq_n[3],
190 		     uuid->seq_n[4], uuid->seq_n[5],
191 		     uuid->seq_n[6], uuid->seq_n[7]);
192 	if (n < 0 || n >= TA_PATH_MAX) {
193 		pr_err("failed to get firmware name\n");
194 		return -EINVAL;
195 	}
196 
197 	mutex_lock(&drv_mutex);
198 	n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
199 	if (n) {
200 		pr_err("failed to load firmware %s\n", fw_name);
201 		rc = -ENOMEM;
202 		goto unlock;
203 	}
204 
205 	*ta_size = roundup(fw->size, PAGE_SIZE);
206 	*ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
207 	if (IS_ERR(*ta)) {
208 		pr_err("%s: get_free_pages failed 0x%llx\n", __func__,
209 		       (u64)*ta);
210 		rc = -ENOMEM;
211 		goto rel_fw;
212 	}
213 
214 	memcpy(*ta, fw->data, fw->size);
215 rel_fw:
216 	release_firmware(fw);
217 unlock:
218 	mutex_unlock(&drv_mutex);
219 	return rc;
220 }
221 
222 static void destroy_session(struct kref *ref)
223 {
224 	struct amdtee_session *sess = container_of(ref, struct amdtee_session,
225 						   refcount);
226 
227 	/* Unload the TA from TEE */
228 	handle_unload_ta(sess->ta_handle);
229 	mutex_lock(&session_list_mutex);
230 	list_del(&sess->list_node);
231 	mutex_unlock(&session_list_mutex);
232 	kfree(sess);
233 }
234 
235 int amdtee_open_session(struct tee_context *ctx,
236 			struct tee_ioctl_open_session_arg *arg,
237 			struct tee_param *param)
238 {
239 	struct amdtee_context_data *ctxdata = ctx->data;
240 	struct amdtee_session *sess = NULL;
241 	u32 session_info;
242 	size_t ta_size;
243 	int rc, i;
244 	void *ta;
245 
246 	if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
247 		pr_err("unsupported client login method\n");
248 		return -EINVAL;
249 	}
250 
251 	rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
252 	if (rc) {
253 		pr_err("failed to copy TA binary\n");
254 		return rc;
255 	}
256 
257 	/* Load the TA binary into TEE environment */
258 	handle_load_ta(ta, ta_size, arg);
259 	if (arg->ret != TEEC_SUCCESS)
260 		goto out;
261 
262 	mutex_lock(&session_list_mutex);
263 	sess = alloc_session(ctxdata, arg->session);
264 	mutex_unlock(&session_list_mutex);
265 
266 	if (!sess) {
267 		rc = -ENOMEM;
268 		goto out;
269 	}
270 
271 	/* Find an empty session index for the given TA */
272 	spin_lock(&sess->lock);
273 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
274 	if (i < TEE_NUM_SESSIONS)
275 		set_bit(i, sess->sess_mask);
276 	spin_unlock(&sess->lock);
277 
278 	if (i >= TEE_NUM_SESSIONS) {
279 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
280 		kref_put(&sess->refcount, destroy_session);
281 		rc = -ENOMEM;
282 		goto out;
283 	}
284 
285 	/* Open session with loaded TA */
286 	handle_open_session(arg, &session_info, param);
287 	if (arg->ret != TEEC_SUCCESS) {
288 		pr_err("open_session failed %d\n", arg->ret);
289 		spin_lock(&sess->lock);
290 		clear_bit(i, sess->sess_mask);
291 		spin_unlock(&sess->lock);
292 		kref_put(&sess->refcount, destroy_session);
293 		goto out;
294 	}
295 
296 	sess->session_info[i] = session_info;
297 	set_session_id(sess->ta_handle, i, &arg->session);
298 out:
299 	free_pages((u64)ta, get_order(ta_size));
300 	return rc;
301 }
302 
303 int amdtee_close_session(struct tee_context *ctx, u32 session)
304 {
305 	struct amdtee_context_data *ctxdata = ctx->data;
306 	u32 i, ta_handle, session_info;
307 	struct amdtee_session *sess;
308 
309 	pr_debug("%s: sid = 0x%x\n", __func__, session);
310 
311 	/*
312 	 * Check that the session is valid and clear the session
313 	 * usage bit
314 	 */
315 	mutex_lock(&session_list_mutex);
316 	sess = find_session(ctxdata, session);
317 	if (sess) {
318 		ta_handle = get_ta_handle(session);
319 		i = get_session_index(session);
320 		session_info = sess->session_info[i];
321 		spin_lock(&sess->lock);
322 		clear_bit(i, sess->sess_mask);
323 		spin_unlock(&sess->lock);
324 	}
325 	mutex_unlock(&session_list_mutex);
326 
327 	if (!sess)
328 		return -EINVAL;
329 
330 	/* Close the session */
331 	handle_close_session(ta_handle, session_info);
332 
333 	kref_put(&sess->refcount, destroy_session);
334 
335 	return 0;
336 }
337 
338 int amdtee_map_shmem(struct tee_shm *shm)
339 {
340 	struct amdtee_context_data *ctxdata;
341 	struct amdtee_shm_data *shmnode;
342 	struct shmem_desc shmem;
343 	int rc, count;
344 	u32 buf_id;
345 
346 	if (!shm)
347 		return -EINVAL;
348 
349 	shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
350 	if (!shmnode)
351 		return -ENOMEM;
352 
353 	count = 1;
354 	shmem.kaddr = shm->kaddr;
355 	shmem.size = shm->size;
356 
357 	/*
358 	 * Send a MAP command to TEE and get the corresponding
359 	 * buffer Id
360 	 */
361 	rc = handle_map_shmem(count, &shmem, &buf_id);
362 	if (rc) {
363 		pr_err("map_shmem failed: ret = %d\n", rc);
364 		kfree(shmnode);
365 		return rc;
366 	}
367 
368 	shmnode->kaddr = shm->kaddr;
369 	shmnode->buf_id = buf_id;
370 	ctxdata = shm->ctx->data;
371 	mutex_lock(&ctxdata->shm_mutex);
372 	list_add(&shmnode->shm_node, &ctxdata->shm_list);
373 	mutex_unlock(&ctxdata->shm_mutex);
374 
375 	pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
376 
377 	return 0;
378 }
379 
380 void amdtee_unmap_shmem(struct tee_shm *shm)
381 {
382 	struct amdtee_context_data *ctxdata;
383 	struct amdtee_shm_data *shmnode;
384 	u32 buf_id;
385 
386 	if (!shm)
387 		return;
388 
389 	buf_id = get_buffer_id(shm);
390 	/* Unmap the shared memory from TEE */
391 	handle_unmap_shmem(buf_id);
392 
393 	ctxdata = shm->ctx->data;
394 	mutex_lock(&ctxdata->shm_mutex);
395 	list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
396 		if (buf_id == shmnode->buf_id) {
397 			list_del(&shmnode->shm_node);
398 			kfree(shmnode);
399 			break;
400 		}
401 	mutex_unlock(&ctxdata->shm_mutex);
402 }
403 
404 int amdtee_invoke_func(struct tee_context *ctx,
405 		       struct tee_ioctl_invoke_arg *arg,
406 		       struct tee_param *param)
407 {
408 	struct amdtee_context_data *ctxdata = ctx->data;
409 	struct amdtee_session *sess;
410 	u32 i, session_info;
411 
412 	/* Check that the session is valid */
413 	mutex_lock(&session_list_mutex);
414 	sess = find_session(ctxdata, arg->session);
415 	if (sess) {
416 		i = get_session_index(arg->session);
417 		session_info = sess->session_info[i];
418 	}
419 	mutex_unlock(&session_list_mutex);
420 
421 	if (!sess)
422 		return -EINVAL;
423 
424 	handle_invoke_cmd(arg, session_info, param);
425 
426 	return 0;
427 }
428 
429 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
430 {
431 	return -EINVAL;
432 }
433 
434 static const struct tee_driver_ops amdtee_ops = {
435 	.get_version = amdtee_get_version,
436 	.open = amdtee_open,
437 	.release = amdtee_release,
438 	.open_session = amdtee_open_session,
439 	.close_session = amdtee_close_session,
440 	.invoke_func = amdtee_invoke_func,
441 	.cancel_req = amdtee_cancel_req,
442 };
443 
444 static const struct tee_desc amdtee_desc = {
445 	.name = DRIVER_NAME "-clnt",
446 	.ops = &amdtee_ops,
447 	.owner = THIS_MODULE,
448 };
449 
450 static int __init amdtee_driver_init(void)
451 {
452 	struct tee_device *teedev;
453 	struct tee_shm_pool *pool;
454 	struct amdtee *amdtee;
455 	int rc;
456 
457 	rc = psp_check_tee_status();
458 	if (rc) {
459 		pr_err("amd-tee driver: tee not present\n");
460 		return rc;
461 	}
462 
463 	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
464 	if (!drv_data)
465 		return -ENOMEM;
466 
467 	amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
468 	if (!amdtee) {
469 		rc = -ENOMEM;
470 		goto err_kfree_drv_data;
471 	}
472 
473 	pool = amdtee_config_shm();
474 	if (IS_ERR(pool)) {
475 		pr_err("shared pool configuration error\n");
476 		rc = PTR_ERR(pool);
477 		goto err_kfree_amdtee;
478 	}
479 
480 	teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
481 	if (IS_ERR(teedev)) {
482 		rc = PTR_ERR(teedev);
483 		goto err_free_pool;
484 	}
485 	amdtee->teedev = teedev;
486 
487 	rc = tee_device_register(amdtee->teedev);
488 	if (rc)
489 		goto err_device_unregister;
490 
491 	amdtee->pool = pool;
492 
493 	drv_data->amdtee = amdtee;
494 
495 	pr_info("amd-tee driver initialization successful\n");
496 	return 0;
497 
498 err_device_unregister:
499 	tee_device_unregister(amdtee->teedev);
500 
501 err_free_pool:
502 	tee_shm_pool_free(pool);
503 
504 err_kfree_amdtee:
505 	kfree(amdtee);
506 
507 err_kfree_drv_data:
508 	kfree(drv_data);
509 	drv_data = NULL;
510 
511 	pr_err("amd-tee driver initialization failed\n");
512 	return rc;
513 }
514 module_init(amdtee_driver_init);
515 
516 static void __exit amdtee_driver_exit(void)
517 {
518 	struct amdtee *amdtee;
519 
520 	if (!drv_data || !drv_data->amdtee)
521 		return;
522 
523 	amdtee = drv_data->amdtee;
524 
525 	tee_device_unregister(amdtee->teedev);
526 	tee_shm_pool_free(amdtee->pool);
527 }
528 module_exit(amdtee_driver_exit);
529 
530 MODULE_AUTHOR(DRIVER_AUTHOR);
531 MODULE_DESCRIPTION("AMD-TEE driver");
532 MODULE_VERSION("1.0");
533 MODULE_LICENSE("Dual MIT/GPL");
534