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
 21static struct amdtee_driver_data *drv_data;
 22static DEFINE_MUTEX(session_list_mutex);
 23
 24static 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
 35static 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
 51static 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
 68static 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 */
109static 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 */
135static 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
153u32 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
170static DEFINE_MUTEX(drv_mutex);
171static 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);
213rel_fw:
214	release_firmware(fw);
215unlock:
216	mutex_unlock(&drv_mutex);
217	return rc;
218}
219
220static 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
231int 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);
299out:
300	free_pages((u64)ta, get_order(ta_size));
301	return rc;
302}
303
304int 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
340int 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
382void 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
406int 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
431int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
432{
433	return -EINVAL;
434}
435
436static 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
446static const struct tee_desc amdtee_desc = {
447	.name = DRIVER_NAME "-clnt",
448	.ops = &amdtee_ops,
449	.owner = THIS_MODULE,
450};
451
452static 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
500err_device_unregister:
501	tee_device_unregister(amdtee->teedev);
502
503err_free_pool:
504	tee_shm_pool_free(pool);
505
506err_kfree_amdtee:
507	kfree(amdtee);
508
509err_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}
516module_init(amdtee_driver_init);
517
518static 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}
530module_exit(amdtee_driver_exit);
531
532MODULE_AUTHOR(DRIVER_AUTHOR);
533MODULE_DESCRIPTION("AMD-TEE driver");
534MODULE_VERSION("1.0");
535MODULE_LICENSE("Dual MIT/GPL");