xref: /linux/drivers/tee/amdtee/core.c (revision ff1f855804cdbbb6db7b9b6df6cab783d1a40d66)
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 
46 	ctx->data = ctxdata;
47 	return 0;
48 }
49 
50 static void release_session(struct amdtee_session *sess)
51 {
52 	int i;
53 
54 	/* Close any open session */
55 	for (i = 0; i < TEE_NUM_SESSIONS; ++i) {
56 		/* Check if session entry 'i' is valid */
57 		if (!test_bit(i, sess->sess_mask))
58 			continue;
59 
60 		handle_close_session(sess->ta_handle, sess->session_info[i]);
61 	}
62 
63 	/* Unload Trusted Application once all sessions are closed */
64 	handle_unload_ta(sess->ta_handle);
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(sizeof(*sess), GFP_KERNEL);
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 u32 get_buffer_id(struct tee_shm *shm)
153 {
154 	struct amdtee_context_data *ctxdata = shm->ctx->data;
155 	struct amdtee_shm_data *shmdata;
156 	u32 buf_id = 0;
157 
158 	list_for_each_entry(shmdata, &ctxdata->shm_list, shm_node)
159 		if (shmdata->kaddr == shm->kaddr) {
160 			buf_id = shmdata->buf_id;
161 			break;
162 		}
163 
164 	return buf_id;
165 }
166 
167 static DEFINE_MUTEX(drv_mutex);
168 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
169 			  size_t *ta_size)
170 {
171 	const struct firmware *fw;
172 	char fw_name[TA_PATH_MAX];
173 	struct {
174 		u32 lo;
175 		u16 mid;
176 		u16 hi_ver;
177 		u8 seq_n[8];
178 	} *uuid = ptr;
179 	int n, rc = 0;
180 
181 	n = snprintf(fw_name, TA_PATH_MAX,
182 		     "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
183 		     TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
184 		     uuid->seq_n[0], uuid->seq_n[1],
185 		     uuid->seq_n[2], uuid->seq_n[3],
186 		     uuid->seq_n[4], uuid->seq_n[5],
187 		     uuid->seq_n[6], uuid->seq_n[7]);
188 	if (n < 0 || n >= TA_PATH_MAX) {
189 		pr_err("failed to get firmware name\n");
190 		return -EINVAL;
191 	}
192 
193 	mutex_lock(&drv_mutex);
194 	n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
195 	if (n) {
196 		pr_err("failed to load firmware %s\n", fw_name);
197 		rc = -ENOMEM;
198 		goto unlock;
199 	}
200 
201 	*ta_size = roundup(fw->size, PAGE_SIZE);
202 	*ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
203 	if (IS_ERR(*ta)) {
204 		pr_err("%s: get_free_pages failed 0x%llx\n", __func__,
205 		       (u64)*ta);
206 		rc = -ENOMEM;
207 		goto rel_fw;
208 	}
209 
210 	memcpy(*ta, fw->data, fw->size);
211 rel_fw:
212 	release_firmware(fw);
213 unlock:
214 	mutex_unlock(&drv_mutex);
215 	return rc;
216 }
217 
218 static void destroy_session(struct kref *ref)
219 {
220 	struct amdtee_session *sess = container_of(ref, struct amdtee_session,
221 						   refcount);
222 
223 	/* Unload the TA from TEE */
224 	handle_unload_ta(sess->ta_handle);
225 	mutex_lock(&session_list_mutex);
226 	list_del(&sess->list_node);
227 	mutex_unlock(&session_list_mutex);
228 	kfree(sess);
229 }
230 
231 int amdtee_open_session(struct tee_context *ctx,
232 			struct tee_ioctl_open_session_arg *arg,
233 			struct tee_param *param)
234 {
235 	struct amdtee_context_data *ctxdata = ctx->data;
236 	struct amdtee_session *sess = NULL;
237 	u32 session_info;
238 	size_t ta_size;
239 	int rc, i;
240 	void *ta;
241 
242 	if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
243 		pr_err("unsupported client login method\n");
244 		return -EINVAL;
245 	}
246 
247 	rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
248 	if (rc) {
249 		pr_err("failed to copy TA binary\n");
250 		return rc;
251 	}
252 
253 	/* Load the TA binary into TEE environment */
254 	handle_load_ta(ta, ta_size, arg);
255 	if (arg->ret != TEEC_SUCCESS)
256 		goto out;
257 
258 	mutex_lock(&session_list_mutex);
259 	sess = alloc_session(ctxdata, arg->session);
260 	mutex_unlock(&session_list_mutex);
261 
262 	if (!sess) {
263 		rc = -ENOMEM;
264 		goto out;
265 	}
266 
267 	/* Find an empty session index for the given TA */
268 	spin_lock(&sess->lock);
269 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
270 	if (i < TEE_NUM_SESSIONS)
271 		set_bit(i, sess->sess_mask);
272 	spin_unlock(&sess->lock);
273 
274 	if (i >= TEE_NUM_SESSIONS) {
275 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
276 		kref_put(&sess->refcount, destroy_session);
277 		rc = -ENOMEM;
278 		goto out;
279 	}
280 
281 	/* Open session with loaded TA */
282 	handle_open_session(arg, &session_info, param);
283 	if (arg->ret != TEEC_SUCCESS) {
284 		pr_err("open_session failed %d\n", arg->ret);
285 		spin_lock(&sess->lock);
286 		clear_bit(i, sess->sess_mask);
287 		spin_unlock(&sess->lock);
288 		kref_put(&sess->refcount, destroy_session);
289 		goto out;
290 	}
291 
292 	sess->session_info[i] = session_info;
293 	set_session_id(sess->ta_handle, i, &arg->session);
294 out:
295 	free_pages((u64)ta, get_order(ta_size));
296 	return rc;
297 }
298 
299 int amdtee_close_session(struct tee_context *ctx, u32 session)
300 {
301 	struct amdtee_context_data *ctxdata = ctx->data;
302 	u32 i, ta_handle, session_info;
303 	struct amdtee_session *sess;
304 
305 	pr_debug("%s: sid = 0x%x\n", __func__, session);
306 
307 	/*
308 	 * Check that the session is valid and clear the session
309 	 * usage bit
310 	 */
311 	mutex_lock(&session_list_mutex);
312 	sess = find_session(ctxdata, session);
313 	if (sess) {
314 		ta_handle = get_ta_handle(session);
315 		i = get_session_index(session);
316 		session_info = sess->session_info[i];
317 		spin_lock(&sess->lock);
318 		clear_bit(i, sess->sess_mask);
319 		spin_unlock(&sess->lock);
320 	}
321 	mutex_unlock(&session_list_mutex);
322 
323 	if (!sess)
324 		return -EINVAL;
325 
326 	/* Close the session */
327 	handle_close_session(ta_handle, session_info);
328 
329 	kref_put(&sess->refcount, destroy_session);
330 
331 	return 0;
332 }
333 
334 int amdtee_map_shmem(struct tee_shm *shm)
335 {
336 	struct amdtee_context_data *ctxdata;
337 	struct amdtee_shm_data *shmnode;
338 	struct shmem_desc shmem;
339 	int rc, count;
340 	u32 buf_id;
341 
342 	if (!shm)
343 		return -EINVAL;
344 
345 	shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
346 	if (!shmnode)
347 		return -ENOMEM;
348 
349 	count = 1;
350 	shmem.kaddr = shm->kaddr;
351 	shmem.size = shm->size;
352 
353 	/*
354 	 * Send a MAP command to TEE and get the corresponding
355 	 * buffer Id
356 	 */
357 	rc = handle_map_shmem(count, &shmem, &buf_id);
358 	if (rc) {
359 		pr_err("map_shmem failed: ret = %d\n", rc);
360 		kfree(shmnode);
361 		return rc;
362 	}
363 
364 	shmnode->kaddr = shm->kaddr;
365 	shmnode->buf_id = buf_id;
366 	ctxdata = shm->ctx->data;
367 	list_add(&shmnode->shm_node, &ctxdata->shm_list);
368 
369 	pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
370 
371 	return 0;
372 }
373 
374 void amdtee_unmap_shmem(struct tee_shm *shm)
375 {
376 	struct amdtee_context_data *ctxdata;
377 	struct amdtee_shm_data *shmnode;
378 	u32 buf_id;
379 
380 	if (!shm)
381 		return;
382 
383 	buf_id = get_buffer_id(shm);
384 	/* Unmap the shared memory from TEE */
385 	handle_unmap_shmem(buf_id);
386 
387 	ctxdata = shm->ctx->data;
388 	list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
389 		if (buf_id == shmnode->buf_id) {
390 			list_del(&shmnode->shm_node);
391 			kfree(shmnode);
392 			break;
393 		}
394 }
395 
396 int amdtee_invoke_func(struct tee_context *ctx,
397 		       struct tee_ioctl_invoke_arg *arg,
398 		       struct tee_param *param)
399 {
400 	struct amdtee_context_data *ctxdata = ctx->data;
401 	struct amdtee_session *sess;
402 	u32 i, session_info;
403 
404 	/* Check that the session is valid */
405 	mutex_lock(&session_list_mutex);
406 	sess = find_session(ctxdata, arg->session);
407 	if (sess) {
408 		i = get_session_index(arg->session);
409 		session_info = sess->session_info[i];
410 	}
411 	mutex_unlock(&session_list_mutex);
412 
413 	if (!sess)
414 		return -EINVAL;
415 
416 	handle_invoke_cmd(arg, session_info, param);
417 
418 	return 0;
419 }
420 
421 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
422 {
423 	return -EINVAL;
424 }
425 
426 static const struct tee_driver_ops amdtee_ops = {
427 	.get_version = amdtee_get_version,
428 	.open = amdtee_open,
429 	.release = amdtee_release,
430 	.open_session = amdtee_open_session,
431 	.close_session = amdtee_close_session,
432 	.invoke_func = amdtee_invoke_func,
433 	.cancel_req = amdtee_cancel_req,
434 };
435 
436 static const struct tee_desc amdtee_desc = {
437 	.name = DRIVER_NAME "-clnt",
438 	.ops = &amdtee_ops,
439 	.owner = THIS_MODULE,
440 };
441 
442 static int __init amdtee_driver_init(void)
443 {
444 	struct tee_device *teedev;
445 	struct tee_shm_pool *pool;
446 	struct amdtee *amdtee;
447 	int rc;
448 
449 	rc = psp_check_tee_status();
450 	if (rc) {
451 		pr_err("amd-tee driver: tee not present\n");
452 		return rc;
453 	}
454 
455 	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
456 	if (!drv_data)
457 		return -ENOMEM;
458 
459 	amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
460 	if (!amdtee) {
461 		rc = -ENOMEM;
462 		goto err_kfree_drv_data;
463 	}
464 
465 	pool = amdtee_config_shm();
466 	if (IS_ERR(pool)) {
467 		pr_err("shared pool configuration error\n");
468 		rc = PTR_ERR(pool);
469 		goto err_kfree_amdtee;
470 	}
471 
472 	teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
473 	if (IS_ERR(teedev)) {
474 		rc = PTR_ERR(teedev);
475 		goto err_free_pool;
476 	}
477 	amdtee->teedev = teedev;
478 
479 	rc = tee_device_register(amdtee->teedev);
480 	if (rc)
481 		goto err_device_unregister;
482 
483 	amdtee->pool = pool;
484 
485 	drv_data->amdtee = amdtee;
486 
487 	pr_info("amd-tee driver initialization successful\n");
488 	return 0;
489 
490 err_device_unregister:
491 	tee_device_unregister(amdtee->teedev);
492 
493 err_free_pool:
494 	tee_shm_pool_free(pool);
495 
496 err_kfree_amdtee:
497 	kfree(amdtee);
498 
499 err_kfree_drv_data:
500 	kfree(drv_data);
501 	drv_data = NULL;
502 
503 	pr_err("amd-tee driver initialization failed\n");
504 	return rc;
505 }
506 module_init(amdtee_driver_init);
507 
508 static void __exit amdtee_driver_exit(void)
509 {
510 	struct amdtee *amdtee;
511 
512 	if (!drv_data || !drv_data->amdtee)
513 		return;
514 
515 	amdtee = drv_data->amdtee;
516 
517 	tee_device_unregister(amdtee->teedev);
518 	tee_shm_pool_free(amdtee->pool);
519 }
520 module_exit(amdtee_driver_exit);
521 
522 MODULE_AUTHOR(DRIVER_AUTHOR);
523 MODULE_DESCRIPTION("AMD-TEE driver");
524 MODULE_VERSION("1.0");
525 MODULE_LICENSE("Dual MIT/GPL");
526