xref: /openbmc/linux/drivers/tee/amdtee/core.c (revision c4e78957)
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 		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 	mutex_destroy(&ctxdata->shm_mutex);
89 	kfree(ctxdata);
90 
91 	ctx->data = NULL;
92 }
93 
94 /**
95  * alloc_session() - Allocate a session structure
96  * @ctxdata:    TEE Context data structure
97  * @session:    Session ID for which 'struct amdtee_session' structure is to be
98  *              allocated.
99  *
100  * Scans the TEE context's session list to check if TA is already loaded in to
101  * TEE. If yes, returns the 'session' structure for that TA. Else allocates,
102  * initializes a new 'session' structure and adds it to context's session list.
103  *
104  * The caller must hold a mutex.
105  *
106  * Returns:
107  * 'struct amdtee_session *' on success and NULL on failure.
108  */
109 static struct amdtee_session *alloc_session(struct amdtee_context_data *ctxdata,
110 					    u32 session)
111 {
112 	struct amdtee_session *sess;
113 	u32 ta_handle = get_ta_handle(session);
114 
115 	/* Scan session list to check if TA is already loaded in to TEE */
116 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
117 		if (sess->ta_handle == ta_handle) {
118 			kref_get(&sess->refcount);
119 			return sess;
120 		}
121 
122 	/* Allocate a new session and add to list */
123 	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
124 	if (sess) {
125 		sess->ta_handle = ta_handle;
126 		kref_init(&sess->refcount);
127 		spin_lock_init(&sess->lock);
128 		list_add(&sess->list_node, &ctxdata->sess_list);
129 	}
130 
131 	return sess;
132 }
133 
134 /* Requires mutex to be held */
135 static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
136 					   u32 session)
137 {
138 	u32 ta_handle = get_ta_handle(session);
139 	u32 index = get_session_index(session);
140 	struct amdtee_session *sess;
141 
142 	if (index >= TEE_NUM_SESSIONS)
143 		return NULL;
144 
145 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
146 		if (ta_handle == sess->ta_handle &&
147 		    test_bit(index, sess->sess_mask))
148 			return sess;
149 
150 	return NULL;
151 }
152 
153 u32 get_buffer_id(struct tee_shm *shm)
154 {
155 	struct amdtee_context_data *ctxdata = shm->ctx->data;
156 	struct amdtee_shm_data *shmdata;
157 	u32 buf_id = 0;
158 
159 	mutex_lock(&ctxdata->shm_mutex);
160 	list_for_each_entry(shmdata, &ctxdata->shm_list, shm_node)
161 		if (shmdata->kaddr == shm->kaddr) {
162 			buf_id = shmdata->buf_id;
163 			break;
164 		}
165 	mutex_unlock(&ctxdata->shm_mutex);
166 
167 	return buf_id;
168 }
169 
170 static DEFINE_MUTEX(drv_mutex);
171 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
172 			  size_t *ta_size)
173 {
174 	const struct firmware *fw;
175 	char fw_name[TA_PATH_MAX];
176 	struct {
177 		u32 lo;
178 		u16 mid;
179 		u16 hi_ver;
180 		u8 seq_n[8];
181 	} *uuid = ptr;
182 	int n, rc = 0;
183 
184 	n = snprintf(fw_name, TA_PATH_MAX,
185 		     "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
186 		     TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
187 		     uuid->seq_n[0], uuid->seq_n[1],
188 		     uuid->seq_n[2], uuid->seq_n[3],
189 		     uuid->seq_n[4], uuid->seq_n[5],
190 		     uuid->seq_n[6], uuid->seq_n[7]);
191 	if (n < 0 || n >= TA_PATH_MAX) {
192 		pr_err("failed to get firmware name\n");
193 		return -EINVAL;
194 	}
195 
196 	mutex_lock(&drv_mutex);
197 	n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
198 	if (n) {
199 		pr_err("failed to load firmware %s\n", fw_name);
200 		rc = -ENOMEM;
201 		goto unlock;
202 	}
203 
204 	*ta_size = roundup(fw->size, PAGE_SIZE);
205 	*ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
206 	if (!*ta) {
207 		pr_err("%s: get_free_pages failed\n", __func__);
208 		rc = -ENOMEM;
209 		goto rel_fw;
210 	}
211 
212 	memcpy(*ta, fw->data, fw->size);
213 rel_fw:
214 	release_firmware(fw);
215 unlock:
216 	mutex_unlock(&drv_mutex);
217 	return rc;
218 }
219 
220 static void destroy_session(struct kref *ref)
221 {
222 	struct amdtee_session *sess = container_of(ref, struct amdtee_session,
223 						   refcount);
224 
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, ta_handle;
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 	ta_handle = get_ta_handle(arg->session);
259 
260 	mutex_lock(&session_list_mutex);
261 	sess = alloc_session(ctxdata, arg->session);
262 	mutex_unlock(&session_list_mutex);
263 
264 	if (!sess) {
265 		handle_unload_ta(ta_handle);
266 		rc = -ENOMEM;
267 		goto out;
268 	}
269 
270 	/* Find an empty session index for the given TA */
271 	spin_lock(&sess->lock);
272 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
273 	if (i < TEE_NUM_SESSIONS)
274 		set_bit(i, sess->sess_mask);
275 	spin_unlock(&sess->lock);
276 
277 	if (i >= TEE_NUM_SESSIONS) {
278 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
279 		handle_unload_ta(ta_handle);
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 		handle_unload_ta(ta_handle);
293 		kref_put(&sess->refcount, destroy_session);
294 		goto out;
295 	}
296 
297 	sess->session_info[i] = session_info;
298 	set_session_id(ta_handle, i, &arg->session);
299 out:
300 	free_pages((u64)ta, get_order(ta_size));
301 	return rc;
302 }
303 
304 int amdtee_close_session(struct tee_context *ctx, u32 session)
305 {
306 	struct amdtee_context_data *ctxdata = ctx->data;
307 	u32 i, ta_handle, session_info;
308 	struct amdtee_session *sess;
309 
310 	pr_debug("%s: sid = 0x%x\n", __func__, session);
311 
312 	/*
313 	 * Check that the session is valid and clear the session
314 	 * usage bit
315 	 */
316 	mutex_lock(&session_list_mutex);
317 	sess = find_session(ctxdata, session);
318 	if (sess) {
319 		ta_handle = get_ta_handle(session);
320 		i = get_session_index(session);
321 		session_info = sess->session_info[i];
322 		spin_lock(&sess->lock);
323 		clear_bit(i, sess->sess_mask);
324 		spin_unlock(&sess->lock);
325 	}
326 	mutex_unlock(&session_list_mutex);
327 
328 	if (!sess)
329 		return -EINVAL;
330 
331 	/* Close the session */
332 	handle_close_session(ta_handle, session_info);
333 	handle_unload_ta(ta_handle);
334 
335 	kref_put(&sess->refcount, destroy_session);
336 
337 	return 0;
338 }
339 
340 int amdtee_map_shmem(struct tee_shm *shm)
341 {
342 	struct amdtee_context_data *ctxdata;
343 	struct amdtee_shm_data *shmnode;
344 	struct shmem_desc shmem;
345 	int rc, count;
346 	u32 buf_id;
347 
348 	if (!shm)
349 		return -EINVAL;
350 
351 	shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
352 	if (!shmnode)
353 		return -ENOMEM;
354 
355 	count = 1;
356 	shmem.kaddr = shm->kaddr;
357 	shmem.size = shm->size;
358 
359 	/*
360 	 * Send a MAP command to TEE and get the corresponding
361 	 * buffer Id
362 	 */
363 	rc = handle_map_shmem(count, &shmem, &buf_id);
364 	if (rc) {
365 		pr_err("map_shmem failed: ret = %d\n", rc);
366 		kfree(shmnode);
367 		return rc;
368 	}
369 
370 	shmnode->kaddr = shm->kaddr;
371 	shmnode->buf_id = buf_id;
372 	ctxdata = shm->ctx->data;
373 	mutex_lock(&ctxdata->shm_mutex);
374 	list_add(&shmnode->shm_node, &ctxdata->shm_list);
375 	mutex_unlock(&ctxdata->shm_mutex);
376 
377 	pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
378 
379 	return 0;
380 }
381 
382 void amdtee_unmap_shmem(struct tee_shm *shm)
383 {
384 	struct amdtee_context_data *ctxdata;
385 	struct amdtee_shm_data *shmnode;
386 	u32 buf_id;
387 
388 	if (!shm)
389 		return;
390 
391 	buf_id = get_buffer_id(shm);
392 	/* Unmap the shared memory from TEE */
393 	handle_unmap_shmem(buf_id);
394 
395 	ctxdata = shm->ctx->data;
396 	mutex_lock(&ctxdata->shm_mutex);
397 	list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
398 		if (buf_id == shmnode->buf_id) {
399 			list_del(&shmnode->shm_node);
400 			kfree(shmnode);
401 			break;
402 		}
403 	mutex_unlock(&ctxdata->shm_mutex);
404 }
405 
406 int amdtee_invoke_func(struct tee_context *ctx,
407 		       struct tee_ioctl_invoke_arg *arg,
408 		       struct tee_param *param)
409 {
410 	struct amdtee_context_data *ctxdata = ctx->data;
411 	struct amdtee_session *sess;
412 	u32 i, session_info;
413 
414 	/* Check that the session is valid */
415 	mutex_lock(&session_list_mutex);
416 	sess = find_session(ctxdata, arg->session);
417 	if (sess) {
418 		i = get_session_index(arg->session);
419 		session_info = sess->session_info[i];
420 	}
421 	mutex_unlock(&session_list_mutex);
422 
423 	if (!sess)
424 		return -EINVAL;
425 
426 	handle_invoke_cmd(arg, session_info, param);
427 
428 	return 0;
429 }
430 
431 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
432 {
433 	return -EINVAL;
434 }
435 
436 static const struct tee_driver_ops amdtee_ops = {
437 	.get_version = amdtee_get_version,
438 	.open = amdtee_open,
439 	.release = amdtee_release,
440 	.open_session = amdtee_open_session,
441 	.close_session = amdtee_close_session,
442 	.invoke_func = amdtee_invoke_func,
443 	.cancel_req = amdtee_cancel_req,
444 };
445 
446 static const struct tee_desc amdtee_desc = {
447 	.name = DRIVER_NAME "-clnt",
448 	.ops = &amdtee_ops,
449 	.owner = THIS_MODULE,
450 };
451 
452 static int __init amdtee_driver_init(void)
453 {
454 	struct tee_device *teedev;
455 	struct tee_shm_pool *pool;
456 	struct amdtee *amdtee;
457 	int rc;
458 
459 	rc = psp_check_tee_status();
460 	if (rc) {
461 		pr_err("amd-tee driver: tee not present\n");
462 		return rc;
463 	}
464 
465 	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
466 	if (!drv_data)
467 		return -ENOMEM;
468 
469 	amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
470 	if (!amdtee) {
471 		rc = -ENOMEM;
472 		goto err_kfree_drv_data;
473 	}
474 
475 	pool = amdtee_config_shm();
476 	if (IS_ERR(pool)) {
477 		pr_err("shared pool configuration error\n");
478 		rc = PTR_ERR(pool);
479 		goto err_kfree_amdtee;
480 	}
481 
482 	teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
483 	if (IS_ERR(teedev)) {
484 		rc = PTR_ERR(teedev);
485 		goto err_free_pool;
486 	}
487 	amdtee->teedev = teedev;
488 
489 	rc = tee_device_register(amdtee->teedev);
490 	if (rc)
491 		goto err_device_unregister;
492 
493 	amdtee->pool = pool;
494 
495 	drv_data->amdtee = amdtee;
496 
497 	pr_info("amd-tee driver initialization successful\n");
498 	return 0;
499 
500 err_device_unregister:
501 	tee_device_unregister(amdtee->teedev);
502 
503 err_free_pool:
504 	tee_shm_pool_free(pool);
505 
506 err_kfree_amdtee:
507 	kfree(amdtee);
508 
509 err_kfree_drv_data:
510 	kfree(drv_data);
511 	drv_data = NULL;
512 
513 	pr_err("amd-tee driver initialization failed\n");
514 	return rc;
515 }
516 module_init(amdtee_driver_init);
517 
518 static void __exit amdtee_driver_exit(void)
519 {
520 	struct amdtee *amdtee;
521 
522 	if (!drv_data || !drv_data->amdtee)
523 		return;
524 
525 	amdtee = drv_data->amdtee;
526 
527 	tee_device_unregister(amdtee->teedev);
528 	tee_shm_pool_free(amdtee->pool);
529 }
530 module_exit(amdtee_driver_exit);
531 
532 MODULE_AUTHOR(DRIVER_AUTHOR);
533 MODULE_DESCRIPTION("AMD-TEE driver");
534 MODULE_VERSION("1.0");
535 MODULE_LICENSE("Dual MIT/GPL");
536