summaryrefslogtreecommitdiff
path: root/drivers/tee/optee/call.c
blob: 13b0269a0abc2c21b31468de587347fa715aa9ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, Linaro Limited
 */
#include <linux/arm-smccc.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "optee_private.h"
#include "optee_smc.h"

struct optee_call_waiter {
	struct list_head list_node;
	struct completion c;
};

static void optee_cq_wait_init(struct optee_call_queue *cq,
			       struct optee_call_waiter *w)
{
	/*
	 * We're preparing to make a call to secure world. In case we can't
	 * allocate a thread in secure world we'll end up waiting in
	 * optee_cq_wait_for_completion().
	 *
	 * Normally if there's no contention in secure world the call will
	 * complete and we can cleanup directly with optee_cq_wait_final().
	 */
	mutex_lock(&cq->mutex);

	/*
	 * We add ourselves to the queue, but we don't wait. This
	 * guarantees that we don't lose a completion if secure world
	 * returns busy and another thread just exited and try to complete
	 * someone.
	 */
	init_completion(&w->c);
	list_add_tail(&w->list_node, &cq->waiters);

	mutex_unlock(&cq->mutex);
}

static void optee_cq_wait_for_completion(struct optee_call_queue *cq,
					 struct optee_call_waiter *w)
{
	wait_for_completion(&w->c);

	mutex_lock(&cq->mutex);

	/* Move to end of list to get out of the way for other waiters */
	list_del(&w->list_node);
	reinit_completion(&w->c);
	list_add_tail(&w->list_node, &cq->waiters);

	mutex_unlock(&cq->mutex);
}

static void optee_cq_complete_one(struct optee_call_queue *cq)
{
	struct optee_call_waiter *w;

	list_for_each_entry(w, &cq->waiters, list_node) {
		if (!completion_done(&w->c)) {
			complete(&w->c);
			break;
		}
	}
}

static void optee_cq_wait_final(struct optee_call_queue *cq,
				struct optee_call_waiter *w)
{
	/*
	 * We're done with the call to secure world. The thread in secure
	 * world that was used for this call is now available for some
	 * other task to use.
	 */
	mutex_lock(&cq->mutex);

	/* Get out of the list */
	list_del(&w->list_node);

	/* Wake up one eventual waiting task */
	optee_cq_complete_one(cq);

	/*
	 * If we're completed we've got a completion from another task that
	 * was just done with its call to secure world. Since yet another
	 * thread now is available in secure world wake up another eventual
	 * waiting task.
	 */
	if (completion_done(&w->c))
		optee_cq_complete_one(cq);

	mutex_unlock(&cq->mutex);
}

/* Requires the filpstate mutex to be held */
static struct optee_session *find_session(struct optee_context_data *ctxdata,
					  u32 session_id)
{
	struct optee_session *sess;

	list_for_each_entry(sess, &ctxdata->sess_list, list_node)
		if (sess->session_id == session_id)
			return sess;

	return NULL;
}

/**
 * optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world
 * @ctx:	calling context
 * @parg:	physical address of message to pass to secure world
 *
 * Does and SMC to OP-TEE in secure world and handles eventual resulting
 * Remote Procedure Calls (RPC) from OP-TEE.
 *
 * Returns return code from secure world, 0 is OK
 */
u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
{
	struct optee *optee = tee_get_drvdata(ctx->teedev);
	struct optee_call_waiter w;
	struct optee_rpc_param param = { };
	struct optee_call_ctx call_ctx = { };
	u32 ret;

	param.a0 = OPTEE_SMC_CALL_WITH_ARG;
	reg_pair_from_64(&param.a1, &param.a2, parg);
	/* Initialize waiter */
	optee_cq_wait_init(&optee->call_queue, &w);
	while (true) {
		struct arm_smccc_res res;

		optee->invoke_fn(param.a0, param.a1, param.a2, param.a3,
				 param.a4, param.a5, param.a6, param.a7,
				 &res);

		if (res.a0 == OPTEE_SMC_RETURN_ETHREAD_LIMIT) {
			/*
			 * Out of threads in secure world, wait for a thread
			 * become available.
			 */
			optee_cq_wait_for_completion(&optee->call_queue, &w);
		} else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) {
			might_sleep();
			param.a0 = res.a0;
			param.a1 = res.a1;
			param.a2 = res.a2;
			param.a3 = res.a3;
			optee_handle_rpc(ctx, &param, &call_ctx);
		} else {
			ret = res.a0;
			break;
		}
	}

	optee_rpc_finalize_call(&call_ctx);
	/*
	 * We're done with our thread in secure world, if there's any
	 * thread waiters wake up one.
	 */
	optee_cq_wait_final(&optee->call_queue, &w);

	return ret;
}

static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,
				   struct optee_msg_arg **msg_arg,
				   phys_addr_t *msg_parg)
{
	int rc;
	struct tee_shm *shm;
	struct optee_msg_arg *ma;

	shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params),
			    TEE_SHM_MAPPED);
	if (IS_ERR(shm))
		return shm;

	ma = tee_shm_get_va(shm, 0);
	if (IS_ERR(ma)) {
		rc = PTR_ERR(ma);
		goto out;
	}

	rc = tee_shm_get_pa(shm, 0, msg_parg);
	if (rc)
		goto out;

	memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
	ma->num_params = num_params;
	*msg_arg = ma;
out:
	if (rc) {
		tee_shm_free(shm);
		return ERR_PTR(rc);
	}

	return shm;
}

int optee_open_session(struct tee_context *ctx,
		       struct tee_ioctl_open_session_arg *arg,
		       struct tee_param *param)
{
	struct optee_context_data *ctxdata = ctx->data;
	int rc;
	struct tee_shm *shm;
	struct optee_msg_arg *msg_arg;
	phys_addr_t msg_parg;
	struct optee_session *sess = NULL;

	/* +2 for the meta parameters added below */
	shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg);
	if (IS_ERR(shm))
		return PTR_ERR(shm);

	msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
	msg_arg->cancel_id = arg->cancel_id;

	/*
	 * Initialize and add the meta parameters needed when opening a
	 * session.
	 */
	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
				  OPTEE_MSG_ATTR_META;
	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
				  OPTEE_MSG_ATTR_META;
	memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
	memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid));
	msg_arg->params[1].u.value.c = arg->clnt_login;

	rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param);
	if (rc)
		goto out;

	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
	if (!sess) {
		rc = -ENOMEM;
		goto out;
	}

	if (optee_do_call_with_arg(ctx, msg_parg)) {
		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
	}

	if (msg_arg->ret == TEEC_SUCCESS) {
		/* A new session has been created, add it to the list. */
		sess->session_id = msg_arg->session;
		mutex_lock(&ctxdata->mutex);
		list_add(&sess->list_node, &ctxdata->sess_list);
		mutex_unlock(&ctxdata->mutex);
	} else {
		kfree(sess);
	}

	if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) {
		arg->ret = TEEC_ERROR_COMMUNICATION;
		arg->ret_origin = TEEC_ORIGIN_COMMS;
		/* Close session again to avoid leakage */
		optee_close_session(ctx, msg_arg->session);
	} else {
		arg->session = msg_arg->session;
		arg->ret = msg_arg->ret;
		arg->ret_origin = msg_arg->ret_origin;
	}
out:
	tee_shm_free(shm);

	return rc;
}

int optee_close_session(struct tee_context *ctx, u32 session)
{
	struct optee_context_data *ctxdata = ctx->data;
	struct tee_shm *shm;
	struct optee_msg_arg *msg_arg;
	phys_addr_t msg_parg;
	struct optee_session *sess;

	/* Check that the session is valid and remove it from the list */
	mutex_lock(&ctxdata->mutex);
	sess = find_session(ctxdata, session);
	if (sess)
		list_del(&sess->list_node);
	mutex_unlock(&ctxdata->mutex);
	if (!sess)
		return -EINVAL;
	kfree(sess);

	shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
	if (IS_ERR(shm))
		return PTR_ERR(shm);

	msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
	msg_arg->session = session;
	optee_do_call_with_arg(ctx, msg_parg);

	tee_shm_free(shm);
	return 0;
}

int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
		      struct tee_param *param)
{
	struct optee_context_data *ctxdata = ctx->data;
	struct tee_shm *shm;
	struct optee_msg_arg *msg_arg;
	phys_addr_t msg_parg;
	struct optee_session *sess;
	int rc;

	/* Check that the session is valid */
	mutex_lock(&ctxdata->mutex);
	sess = find_session(ctxdata, arg->session);
	mutex_unlock(&ctxdata->mutex);
	if (!sess)
		return -EINVAL;

	shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg);
	if (IS_ERR(shm))
		return PTR_ERR(shm);
	msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
	msg_arg->func = arg->func;
	msg_arg->session = arg->session;
	msg_arg->cancel_id = arg->cancel_id;

	rc = optee_to_msg_param(msg_arg->params, arg->num_params, param);
	if (rc)
		goto out;

	if (optee_do_call_with_arg(ctx, msg_parg)) {
		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
	}

	if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) {
		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
	}

	arg->ret = msg_arg->ret;
	arg->ret_origin = msg_arg->ret_origin;
out:
	tee_shm_free(shm);
	return rc;
}

int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
{
	struct optee_context_data *ctxdata = ctx->data;
	struct tee_shm *shm;
	struct optee_msg_arg *msg_arg;
	phys_addr_t msg_parg;
	struct optee_session *sess;

	/* Check that the session is valid */
	mutex_lock(&ctxdata->mutex);
	sess = find_session(ctxdata, session);
	mutex_unlock(&ctxdata->mutex);
	if (!sess)
		return -EINVAL;

	shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
	if (IS_ERR(shm))
		return PTR_ERR(shm);

	msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
	msg_arg->session = session;
	msg_arg->cancel_id = cancel_id;
	optee_do_call_with_arg(ctx, msg_parg);

	tee_shm_free(shm);
	return 0;
}

/**
 * optee_enable_shm_cache() - Enables caching of some shared memory allocation
 *			      in OP-TEE
 * @optee:	main service struct
 */
void optee_enable_shm_cache(struct optee *optee)
{
	struct optee_call_waiter w;

	/* We need to retry until secure world isn't busy. */
	optee_cq_wait_init(&optee->call_queue, &w);
	while (true) {
		struct arm_smccc_res res;

		optee->invoke_fn(OPTEE_SMC_ENABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
				 0, &res);
		if (res.a0 == OPTEE_SMC_RETURN_OK)
			break;
		optee_cq_wait_for_completion(&optee->call_queue, &w);
	}
	optee_cq_wait_final(&optee->call_queue, &w);
}

/**
 * optee_disable_shm_cache() - Disables caching of some shared memory allocation
 *			      in OP-TEE
 * @optee:	main service struct
 */
void optee_disable_shm_cache(struct optee *optee)
{
	struct optee_call_waiter w;

	/* We need to retry until secure world isn't busy. */
	optee_cq_wait_init(&optee->call_queue, &w);
	while (true) {
		union {
			struct arm_smccc_res smccc;
			struct optee_smc_disable_shm_cache_result result;
		} res;

		optee->invoke_fn(OPTEE_SMC_DISABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
				 0, &res.smccc);
		if (res.result.status == OPTEE_SMC_RETURN_ENOTAVAIL)
			break; /* All shm's freed */
		if (res.result.status == OPTEE_SMC_RETURN_OK) {
			struct tee_shm *shm;

			shm = reg_pair_to_ptr(res.result.shm_upper32,
					      res.result.shm_lower32);
			tee_shm_free(shm);
		} else {
			optee_cq_wait_for_completion(&optee->call_queue, &w);
		}
	}
	optee_cq_wait_final(&optee->call_queue, &w);
}

#define PAGELIST_ENTRIES_PER_PAGE				\
	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)

/**
 * optee_fill_pages_list() - write list of user pages to given shared
 * buffer.
 *
 * @dst: page-aligned buffer where list of pages will be stored
 * @pages: array of pages that represents shared buffer
 * @num_pages: number of entries in @pages
 * @page_offset: offset of user buffer from page start
 *
 * @dst should be big enough to hold list of user page addresses and
 *	links to the next pages of buffer
 */
void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
			   size_t page_offset)
{
	int n = 0;
	phys_addr_t optee_page;
	/*
	 * Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h
	 * for details.
	 */
	struct {
		u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
		u64 next_page_data;
	} *pages_data;

	/*
	 * Currently OP-TEE uses 4k page size and it does not looks
	 * like this will change in the future.  On other hand, there are
	 * no know ARM architectures with page size < 4k.
	 * Thus the next built assert looks redundant. But the following
	 * code heavily relies on this assumption, so it is better be
	 * safe than sorry.
	 */
	BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);

	pages_data = (void *)dst;
	/*
	 * If linux page is bigger than 4k, and user buffer offset is
	 * larger than 4k/8k/12k/etc this will skip first 4k pages,
	 * because they bear no value data for OP-TEE.
	 */
	optee_page = page_to_phys(*pages) +
		round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);

	while (true) {
		pages_data->pages_list[n++] = optee_page;

		if (n == PAGELIST_ENTRIES_PER_PAGE) {
			pages_data->next_page_data =
				virt_to_phys(pages_data + 1);
			pages_data++;
			n = 0;
		}

		optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;
		if (!(optee_page & ~PAGE_MASK)) {
			if (!--num_pages)
				break;
			pages++;
			optee_page = page_to_phys(*pages);
		}
	}
}

/*
 * The final entry in each pagelist page is a pointer to the next
 * pagelist page.
 */
static size_t get_pages_list_size(size_t num_entries)
{
	int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);

	return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;
}

u64 *optee_allocate_pages_list(size_t num_entries)
{
	return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
}

void optee_free_pages_list(void *list, size_t num_entries)
{
	free_pages_exact(list, get_pages_list_size(num_entries));
}

static bool is_normal_memory(pgprot_t p)
{
#if defined(CONFIG_ARM)
	return (pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEALLOC;
#elif defined(CONFIG_ARM64)
	return (pgprot_val(p) & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL);
#else
#error "Unuspported architecture"
#endif
}

static int __check_mem_type(struct vm_area_struct *vma, unsigned long end)
{
	while (vma && is_normal_memory(vma->vm_page_prot)) {
		if (vma->vm_end >= end)
			return 0;
		vma = vma->vm_next;
	}

	return -EINVAL;
}

static int check_mem_type(unsigned long start, size_t num_pages)
{
	struct mm_struct *mm = current->mm;
	int rc;

	down_read(&mm->mmap_sem);
	rc = __check_mem_type(find_vma(mm, start),
			      start + num_pages * PAGE_SIZE);
	up_read(&mm->mmap_sem);

	return rc;
}

int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
		       struct page **pages, size_t num_pages,
		       unsigned long start)
{
	struct tee_shm *shm_arg = NULL;
	struct optee_msg_arg *msg_arg;
	u64 *pages_list;
	phys_addr_t msg_parg;
	int rc;

	if (!num_pages)
		return -EINVAL;

	rc = check_mem_type(start, num_pages);
	if (rc)
		return rc;

	pages_list = optee_allocate_pages_list(num_pages);
	if (!pages_list)
		return -ENOMEM;

	shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
	if (IS_ERR(shm_arg)) {
		rc = PTR_ERR(shm_arg);
		goto out;
	}

	optee_fill_pages_list(pages_list, pages, num_pages,
			      tee_shm_get_page_offset(shm));

	msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
	msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
				OPTEE_MSG_ATTR_NONCONTIG;
	msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
	msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
	/*
	 * In the least bits of msg_arg->params->u.tmem.buf_ptr we
	 * store buffer offset from 4k page, as described in OP-TEE ABI.
	 */
	msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
	  (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));

	if (optee_do_call_with_arg(ctx, msg_parg) ||
	    msg_arg->ret != TEEC_SUCCESS)
		rc = -EINVAL;

	tee_shm_free(shm_arg);
out:
	optee_free_pages_list(pages_list, num_pages);
	return rc;
}

int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
{
	struct tee_shm *shm_arg;
	struct optee_msg_arg *msg_arg;
	phys_addr_t msg_parg;
	int rc = 0;

	shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
	if (IS_ERR(shm_arg))
		return PTR_ERR(shm_arg);

	msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;

	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
	msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;

	if (optee_do_call_with_arg(ctx, msg_parg) ||
	    msg_arg->ret != TEEC_SUCCESS)
		rc = -EINVAL;
	tee_shm_free(shm_arg);
	return rc;
}

int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
			    struct page **pages, size_t num_pages,
			    unsigned long start)
{
	/*
	 * We don't want to register supplicant memory in OP-TEE.
	 * Instead information about it will be passed in RPC code.
	 */
	return check_mem_type(start, num_pages);
}

int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm)
{
	return 0;
}