xref: /openbmc/linux/drivers/tee/amdtee/core.c (revision aa017ab9)
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 static struct amdtee_shm_context shmctx;
24 
25 static void amdtee_get_version(struct tee_device *teedev,
26 			       struct tee_ioctl_version_data *vers)
27 {
28 	struct tee_ioctl_version_data v = {
29 		.impl_id = TEE_IMPL_ID_AMDTEE,
30 		.impl_caps = 0,
31 		.gen_caps = TEE_GEN_CAP_GP,
32 	};
33 	*vers = v;
34 }
35 
36 static int amdtee_open(struct tee_context *ctx)
37 {
38 	struct amdtee_context_data *ctxdata;
39 
40 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
41 	if (!ctxdata)
42 		return -ENOMEM;
43 
44 	INIT_LIST_HEAD(&ctxdata->sess_list);
45 	INIT_LIST_HEAD(&shmctx.shmdata_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 	}
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 	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 	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
143 		if (ta_handle == sess->ta_handle &&
144 		    test_bit(index, sess->sess_mask))
145 			return sess;
146 
147 	return NULL;
148 }
149 
150 u32 get_buffer_id(struct tee_shm *shm)
151 {
152 	u32 buf_id = 0;
153 	struct amdtee_shm_data *shmdata;
154 
155 	list_for_each_entry(shmdata, &shmctx.shmdata_list, shm_node)
156 		if (shmdata->kaddr == shm->kaddr) {
157 			buf_id = shmdata->buf_id;
158 			break;
159 		}
160 
161 	return buf_id;
162 }
163 
164 static DEFINE_MUTEX(drv_mutex);
165 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
166 			  size_t *ta_size)
167 {
168 	const struct firmware *fw;
169 	char fw_name[TA_PATH_MAX];
170 	struct {
171 		u32 lo;
172 		u16 mid;
173 		u16 hi_ver;
174 		u8 seq_n[8];
175 	} *uuid = ptr;
176 	int n, rc = 0;
177 
178 	n = snprintf(fw_name, TA_PATH_MAX,
179 		     "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
180 		     TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
181 		     uuid->seq_n[0], uuid->seq_n[1],
182 		     uuid->seq_n[2], uuid->seq_n[3],
183 		     uuid->seq_n[4], uuid->seq_n[5],
184 		     uuid->seq_n[6], uuid->seq_n[7]);
185 	if (n < 0 || n >= TA_PATH_MAX) {
186 		pr_err("failed to get firmware name\n");
187 		return -EINVAL;
188 	}
189 
190 	mutex_lock(&drv_mutex);
191 	n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
192 	if (n) {
193 		pr_err("failed to load firmware %s\n", fw_name);
194 		rc = -ENOMEM;
195 		goto unlock;
196 	}
197 
198 	*ta_size = roundup(fw->size, PAGE_SIZE);
199 	*ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
200 	if (IS_ERR(*ta)) {
201 		pr_err("%s: get_free_pages failed 0x%llx\n", __func__,
202 		       (u64)*ta);
203 		rc = -ENOMEM;
204 		goto rel_fw;
205 	}
206 
207 	memcpy(*ta, fw->data, fw->size);
208 rel_fw:
209 	release_firmware(fw);
210 unlock:
211 	mutex_unlock(&drv_mutex);
212 	return rc;
213 }
214 
215 int amdtee_open_session(struct tee_context *ctx,
216 			struct tee_ioctl_open_session_arg *arg,
217 			struct tee_param *param)
218 {
219 	struct amdtee_context_data *ctxdata = ctx->data;
220 	struct amdtee_session *sess = NULL;
221 	u32 session_info;
222 	size_t ta_size;
223 	int rc, i;
224 	void *ta;
225 
226 	if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
227 		pr_err("unsupported client login method\n");
228 		return -EINVAL;
229 	}
230 
231 	rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
232 	if (rc) {
233 		pr_err("failed to copy TA binary\n");
234 		return rc;
235 	}
236 
237 	/* Load the TA binary into TEE environment */
238 	handle_load_ta(ta, ta_size, arg);
239 	if (arg->ret == TEEC_SUCCESS) {
240 		mutex_lock(&session_list_mutex);
241 		sess = alloc_session(ctxdata, arg->session);
242 		mutex_unlock(&session_list_mutex);
243 	}
244 
245 	if (arg->ret != TEEC_SUCCESS)
246 		goto out;
247 
248 	if (!sess) {
249 		rc = -ENOMEM;
250 		goto out;
251 	}
252 
253 	/* Find an empty session index for the given TA */
254 	spin_lock(&sess->lock);
255 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
256 	if (i < TEE_NUM_SESSIONS)
257 		set_bit(i, sess->sess_mask);
258 	spin_unlock(&sess->lock);
259 
260 	if (i >= TEE_NUM_SESSIONS) {
261 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
262 		rc = -ENOMEM;
263 		goto out;
264 	}
265 
266 	/* Open session with loaded TA */
267 	handle_open_session(arg, &session_info, param);
268 
269 	if (arg->ret == TEEC_SUCCESS) {
270 		sess->session_info[i] = session_info;
271 		set_session_id(sess->ta_handle, i, &arg->session);
272 	} else {
273 		pr_err("open_session failed %d\n", arg->ret);
274 		spin_lock(&sess->lock);
275 		clear_bit(i, sess->sess_mask);
276 		spin_unlock(&sess->lock);
277 	}
278 out:
279 	free_pages((u64)ta, get_order(ta_size));
280 	return rc;
281 }
282 
283 static void destroy_session(struct kref *ref)
284 {
285 	struct amdtee_session *sess = container_of(ref, struct amdtee_session,
286 						   refcount);
287 
288 	/* Unload the TA from TEE */
289 	handle_unload_ta(sess->ta_handle);
290 	mutex_lock(&session_list_mutex);
291 	list_del(&sess->list_node);
292 	mutex_unlock(&session_list_mutex);
293 	kfree(sess);
294 }
295 
296 int amdtee_close_session(struct tee_context *ctx, u32 session)
297 {
298 	struct amdtee_context_data *ctxdata = ctx->data;
299 	u32 i, ta_handle, session_info;
300 	struct amdtee_session *sess;
301 
302 	pr_debug("%s: sid = 0x%x\n", __func__, session);
303 
304 	/*
305 	 * Check that the session is valid and clear the session
306 	 * usage bit
307 	 */
308 	mutex_lock(&session_list_mutex);
309 	sess = find_session(ctxdata, session);
310 	if (sess) {
311 		ta_handle = get_ta_handle(session);
312 		i = get_session_index(session);
313 		session_info = sess->session_info[i];
314 		spin_lock(&sess->lock);
315 		clear_bit(i, sess->sess_mask);
316 		spin_unlock(&sess->lock);
317 	}
318 	mutex_unlock(&session_list_mutex);
319 
320 	if (!sess)
321 		return -EINVAL;
322 
323 	/* Close the session */
324 	handle_close_session(ta_handle, session_info);
325 
326 	kref_put(&sess->refcount, destroy_session);
327 
328 	return 0;
329 }
330 
331 int amdtee_map_shmem(struct tee_shm *shm)
332 {
333 	struct shmem_desc shmem;
334 	struct amdtee_shm_data *shmnode;
335 	int rc, count;
336 	u32 buf_id;
337 
338 	if (!shm)
339 		return -EINVAL;
340 
341 	shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
342 	if (!shmnode)
343 		return -ENOMEM;
344 
345 	count = 1;
346 	shmem.kaddr = shm->kaddr;
347 	shmem.size = shm->size;
348 
349 	/*
350 	 * Send a MAP command to TEE and get the corresponding
351 	 * buffer Id
352 	 */
353 	rc = handle_map_shmem(count, &shmem, &buf_id);
354 	if (rc) {
355 		pr_err("map_shmem failed: ret = %d\n", rc);
356 		kfree(shmnode);
357 		return rc;
358 	}
359 
360 	shmnode->kaddr = shm->kaddr;
361 	shmnode->buf_id = buf_id;
362 	list_add(&shmnode->shm_node, &shmctx.shmdata_list);
363 
364 	pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
365 
366 	return 0;
367 }
368 
369 void amdtee_unmap_shmem(struct tee_shm *shm)
370 {
371 	struct amdtee_shm_data *shmnode;
372 	u32 buf_id;
373 
374 	if (!shm)
375 		return;
376 
377 	buf_id = get_buffer_id(shm);
378 	/* Unmap the shared memory from TEE */
379 	handle_unmap_shmem(buf_id);
380 
381 	list_for_each_entry(shmnode, &shmctx.shmdata_list, shm_node)
382 		if (buf_id == shmnode->buf_id) {
383 			list_del(&shmnode->shm_node);
384 			kfree(shmnode);
385 			break;
386 		}
387 }
388 
389 int amdtee_invoke_func(struct tee_context *ctx,
390 		       struct tee_ioctl_invoke_arg *arg,
391 		       struct tee_param *param)
392 {
393 	struct amdtee_context_data *ctxdata = ctx->data;
394 	struct amdtee_session *sess;
395 	u32 i, session_info;
396 
397 	/* Check that the session is valid */
398 	mutex_lock(&session_list_mutex);
399 	sess = find_session(ctxdata, arg->session);
400 	if (sess) {
401 		i = get_session_index(arg->session);
402 		session_info = sess->session_info[i];
403 	}
404 	mutex_unlock(&session_list_mutex);
405 
406 	if (!sess)
407 		return -EINVAL;
408 
409 	handle_invoke_cmd(arg, session_info, param);
410 
411 	return 0;
412 }
413 
414 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
415 {
416 	return -EINVAL;
417 }
418 
419 static const struct tee_driver_ops amdtee_ops = {
420 	.get_version = amdtee_get_version,
421 	.open = amdtee_open,
422 	.release = amdtee_release,
423 	.open_session = amdtee_open_session,
424 	.close_session = amdtee_close_session,
425 	.invoke_func = amdtee_invoke_func,
426 	.cancel_req = amdtee_cancel_req,
427 };
428 
429 static const struct tee_desc amdtee_desc = {
430 	.name = DRIVER_NAME "-clnt",
431 	.ops = &amdtee_ops,
432 	.owner = THIS_MODULE,
433 };
434 
435 static int __init amdtee_driver_init(void)
436 {
437 	struct tee_device *teedev;
438 	struct tee_shm_pool *pool;
439 	struct amdtee *amdtee;
440 	int rc;
441 
442 	rc = psp_check_tee_status();
443 	if (rc) {
444 		pr_err("amd-tee driver: tee not present\n");
445 		return rc;
446 	}
447 
448 	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
449 	if (!drv_data)
450 		return -ENOMEM;
451 
452 	amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
453 	if (!amdtee) {
454 		rc = -ENOMEM;
455 		goto err_kfree_drv_data;
456 	}
457 
458 	pool = amdtee_config_shm();
459 	if (IS_ERR(pool)) {
460 		pr_err("shared pool configuration error\n");
461 		rc = PTR_ERR(pool);
462 		goto err_kfree_amdtee;
463 	}
464 
465 	teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
466 	if (IS_ERR(teedev)) {
467 		rc = PTR_ERR(teedev);
468 		goto err_free_pool;
469 	}
470 	amdtee->teedev = teedev;
471 
472 	rc = tee_device_register(amdtee->teedev);
473 	if (rc)
474 		goto err_device_unregister;
475 
476 	amdtee->pool = pool;
477 
478 	drv_data->amdtee = amdtee;
479 
480 	pr_info("amd-tee driver initialization successful\n");
481 	return 0;
482 
483 err_device_unregister:
484 	tee_device_unregister(amdtee->teedev);
485 
486 err_free_pool:
487 	tee_shm_pool_free(pool);
488 
489 err_kfree_amdtee:
490 	kfree(amdtee);
491 
492 err_kfree_drv_data:
493 	kfree(drv_data);
494 	drv_data = NULL;
495 
496 	pr_err("amd-tee driver initialization failed\n");
497 	return rc;
498 }
499 module_init(amdtee_driver_init);
500 
501 static void __exit amdtee_driver_exit(void)
502 {
503 	struct amdtee *amdtee;
504 
505 	if (!drv_data || !drv_data->amdtee)
506 		return;
507 
508 	amdtee = drv_data->amdtee;
509 
510 	tee_device_unregister(amdtee->teedev);
511 	tee_shm_pool_free(amdtee->pool);
512 }
513 module_exit(amdtee_driver_exit);
514 
515 MODULE_AUTHOR(DRIVER_AUTHOR);
516 MODULE_DESCRIPTION("AMD-TEE driver");
517 MODULE_VERSION("1.0");
518 MODULE_LICENSE("Dual MIT/GPL");
519