summaryrefslogtreecommitdiffstats
path: root/drivers/tee/optee/core.c
blob: 0987074d7ed0b97d17f6cbc201e156631099bf0d (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
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, Linaro Limited
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/arm-smccc.h>
#include <linux/crash_dump.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
#include "optee_private.h"
#include "optee_smc.h"
#include "shm_pool.h"

#define DRIVER_NAME "optee"

#define OPTEE_SHM_NUM_PRIV_PAGES	CONFIG_OPTEE_SHM_NUM_PRIV_PAGES

/**
 * optee_from_msg_param() - convert from OPTEE_MSG parameters to
 *			    struct tee_param
 * @params:	subsystem internal parameter representation
 * @num_params:	number of elements in the parameter arrays
 * @msg_params:	OPTEE_MSG parameters
 * Returns 0 on success or <0 on failure
 */
int optee_from_msg_param(struct tee_param *params, size_t num_params,
			 const struct optee_msg_param *msg_params)
{
	int rc;
	size_t n;
	struct tee_shm *shm;
	phys_addr_t pa;

	for (n = 0; n < num_params; n++) {
		struct tee_param *p = params + n;
		const struct optee_msg_param *mp = msg_params + n;
		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;

		switch (attr) {
		case OPTEE_MSG_ATTR_TYPE_NONE:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
			memset(&p->u, 0, sizeof(p->u));
			break;
		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
				  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
			p->u.value.a = mp->u.value.a;
			p->u.value.b = mp->u.value.b;
			p->u.value.c = mp->u.value.c;
			break;
		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
				  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
			p->u.memref.size = mp->u.tmem.size;
			shm = (struct tee_shm *)(unsigned long)
				mp->u.tmem.shm_ref;
			if (!shm) {
				p->u.memref.shm_offs = 0;
				p->u.memref.shm = NULL;
				break;
			}
			rc = tee_shm_get_pa(shm, 0, &pa);
			if (rc)
				return rc;
			p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
			p->u.memref.shm = shm;
			break;
		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
				  attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
			p->u.memref.size = mp->u.rmem.size;
			shm = (struct tee_shm *)(unsigned long)
				mp->u.rmem.shm_ref;

			if (!shm) {
				p->u.memref.shm_offs = 0;
				p->u.memref.shm = NULL;
				break;
			}
			p->u.memref.shm_offs = mp->u.rmem.offs;
			p->u.memref.shm = shm;

			break;

		default:
			return -EINVAL;
		}
	}
	return 0;
}

static int to_msg_param_tmp_mem(struct optee_msg_param *mp,
				const struct tee_param *p)
{
	int rc;
	phys_addr_t pa;

	mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT + p->attr -
		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;

	mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
	mp->u.tmem.size = p->u.memref.size;

	if (!p->u.memref.shm) {
		mp->u.tmem.buf_ptr = 0;
		return 0;
	}

	rc = tee_shm_get_pa(p->u.memref.shm, p->u.memref.shm_offs, &pa);
	if (rc)
		return rc;

	mp->u.tmem.buf_ptr = pa;
	mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
		    OPTEE_MSG_ATTR_CACHE_SHIFT;

	return 0;
}

static int to_msg_param_reg_mem(struct optee_msg_param *mp,
				const struct tee_param *p)
{
	mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;

	mp->u.rmem.shm_ref = (unsigned long)p->u.memref.shm;
	mp->u.rmem.size = p->u.memref.size;
	mp->u.rmem.offs = p->u.memref.shm_offs;
	return 0;
}

/**
 * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
 * @msg_params:	OPTEE_MSG parameters
 * @num_params:	number of elements in the parameter arrays
 * @params:	subsystem itnernal parameter representation
 * Returns 0 on success or <0 on failure
 */
int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
		       const struct tee_param *params)
{
	int rc;
	size_t n;

	for (n = 0; n < num_params; n++) {
		const struct tee_param *p = params + n;
		struct optee_msg_param *mp = msg_params + n;

		switch (p->attr) {
		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
			memset(&mp->u, 0, sizeof(mp->u));
			break;
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
				   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
			mp->u.value.a = p->u.value.a;
			mp->u.value.b = p->u.value.b;
			mp->u.value.c = p->u.value.c;
			break;
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
			if (tee_shm_is_registered(p->u.memref.shm))
				rc = to_msg_param_reg_mem(mp, p);
			else
				rc = to_msg_param_tmp_mem(mp, p);
			if (rc)
				return rc;
			break;
		default:
			return -EINVAL;
		}
	}
	return 0;
}

static void optee_get_version(struct tee_device *teedev,
			      struct tee_ioctl_version_data *vers)
{
	struct tee_ioctl_version_data v = {
		.impl_id = TEE_IMPL_ID_OPTEE,
		.impl_caps = TEE_OPTEE_CAP_TZ,
		.gen_caps = TEE_GEN_CAP_GP,
	};
	struct optee *optee = tee_get_drvdata(teedev);

	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
		v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
	*vers = v;
}

static void optee_bus_scan(struct work_struct *work)
{
	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
}

static int optee_open(struct tee_context *ctx)
{
	struct optee_context_data *ctxdata;
	struct tee_device *teedev = ctx->teedev;
	struct optee *optee = tee_get_drvdata(teedev);

	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
	if (!ctxdata)
		return -ENOMEM;

	if (teedev == optee->supp_teedev) {
		bool busy = true;

		mutex_lock(&optee->supp.mutex);
		if (!optee->supp.ctx) {
			busy = false;
			optee->supp.ctx = ctx;
		}
		mutex_unlock(&optee->supp.mutex);
		if (busy) {
			kfree(ctxdata);
			return -EBUSY;
		}

		if (!optee->scan_bus_done) {
			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
			optee->scan_bus_wq = create_workqueue("optee_bus_scan");
			if (!optee->scan_bus_wq) {
				kfree(ctxdata);
				return -ECHILD;
			}
			queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
			optee->scan_bus_done = true;
		}
	}
	mutex_init(&ctxdata->mutex);
	INIT_LIST_HEAD(&ctxdata->sess_list);

	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
		ctx->cap_memref_null  = true;
	else
		ctx->cap_memref_null = false;

	ctx->data = ctxdata;
	return 0;
}

static void optee_release(struct tee_context *ctx)
{
	struct optee_context_data *ctxdata = ctx->data;
	struct tee_device *teedev = ctx->teedev;
	struct optee *optee = tee_get_drvdata(teedev);
	struct tee_shm *shm;
	struct optee_msg_arg *arg = NULL;
	phys_addr_t parg;
	struct optee_session *sess;
	struct optee_session *sess_tmp;

	if (!ctxdata)
		return;

	shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED);
	if (!IS_ERR(shm)) {
		arg = tee_shm_get_va(shm, 0);
		/*
		 * If va2pa fails for some reason, we can't call into
		 * secure world, only free the memory. Secure OS will leak
		 * sessions and finally refuse more sessions, but we will
		 * at least let normal world reclaim its memory.
		 */
		if (!IS_ERR(arg))
			if (tee_shm_va2pa(shm, arg, &parg))
				arg = NULL; /* prevent usage of parg below */
	}

	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
				 list_node) {
		list_del(&sess->list_node);
		if (!IS_ERR_OR_NULL(arg)) {
			memset(arg, 0, sizeof(*arg));
			arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
			arg->session = sess->session_id;
			optee_do_call_with_arg(ctx, parg);
		}
		kfree(sess);
	}
	kfree(ctxdata);

	if (!IS_ERR(shm))
		tee_shm_free(shm);

	ctx->data = NULL;

	if (teedev == optee->supp_teedev) {
		if (optee->scan_bus_wq) {
			destroy_workqueue(optee->scan_bus_wq);
			optee->scan_bus_wq = NULL;
		}
		optee_supp_release(&optee->supp);
	}
}

static const struct tee_driver_ops optee_ops = {
	.get_version = optee_get_version,
	.open = optee_open,
	.release = optee_release,
	.open_session = optee_open_session,
	.close_session = optee_close_session,
	.invoke_func = optee_invoke_func,
	.cancel_req = optee_cancel_req,
	.shm_register = optee_shm_register,
	.shm_unregister = optee_shm_unregister,
};

static const struct tee_desc optee_desc = {
	.name = DRIVER_NAME "-clnt",
	.ops = &optee_ops,
	.owner = THIS_MODULE,
};

static const struct tee_driver_ops optee_supp_ops = {
	.get_version = optee_get_version,
	.open = optee_open,
	.release = optee_release,
	.supp_recv = optee_supp_recv,
	.supp_send = optee_supp_send,
	.shm_register = optee_shm_register_supp,
	.shm_unregister = optee_shm_unregister_supp,
};

static const struct tee_desc optee_supp_desc = {
	.name = DRIVER_NAME "-supp",
	.ops = &optee_supp_ops,
	.owner = THIS_MODULE,
	.flags = TEE_DESC_PRIVILEGED,
};

static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
{
	struct arm_smccc_res res;

	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);

	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
		return true;
	return false;
}

static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_call_get_os_revision_result result;
	} res = {
		.result = {
			.build_id = 0
		}
	};

	invoke_fn(OPTEE_SMC_CALL_GET_OS_REVISION, 0, 0, 0, 0, 0, 0, 0,
		  &res.smccc);

	if (res.result.build_id)
		pr_info("revision %lu.%lu (%08lx)", res.result.major,
			res.result.minor, res.result.build_id);
	else
		pr_info("revision %lu.%lu", res.result.major, res.result.minor);
}

static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_calls_revision_result result;
	} res;

	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);

	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
		return true;
	return false;
}

static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
					    u32 *sec_caps)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_exchange_capabilities_result result;
	} res;
	u32 a1 = 0;

	/*
	 * TODO This isn't enough to tell if it's UP system (from kernel
	 * point of view) or not, is_smp() returns the the information
	 * needed, but can't be called directly from here.
	 */
	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;

	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
		  &res.smccc);

	if (res.result.status != OPTEE_SMC_RETURN_OK)
		return false;

	*sec_caps = res.result.capabilities;
	return true;
}

static struct tee_shm_pool *optee_config_dyn_shm(void)
{
	struct tee_shm_pool_mgr *priv_mgr;
	struct tee_shm_pool_mgr *dmabuf_mgr;
	void *rc;

	rc = optee_shm_pool_alloc_pages();
	if (IS_ERR(rc))
		return rc;
	priv_mgr = rc;

	rc = optee_shm_pool_alloc_pages();
	if (IS_ERR(rc)) {
		tee_shm_pool_mgr_destroy(priv_mgr);
		return rc;
	}
	dmabuf_mgr = rc;

	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
	if (IS_ERR(rc)) {
		tee_shm_pool_mgr_destroy(priv_mgr);
		tee_shm_pool_mgr_destroy(dmabuf_mgr);
	}

	return rc;
}

static struct tee_shm_pool *
optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
{
	union {
		struct arm_smccc_res smccc;
		struct optee_smc_get_shm_config_result result;
	} res;
	unsigned long vaddr;
	phys_addr_t paddr;
	size_t size;
	phys_addr_t begin;
	phys_addr_t end;
	void *va;
	struct tee_shm_pool_mgr *priv_mgr;
	struct tee_shm_pool_mgr *dmabuf_mgr;
	void *rc;
	const int sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;

	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
	if (res.result.status != OPTEE_SMC_RETURN_OK) {
		pr_err("static shm service not available\n");
		return ERR_PTR(-ENOENT);
	}

	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
		pr_err("only normal cached shared memory supported\n");
		return ERR_PTR(-EINVAL);
	}

	begin = roundup(res.result.start, PAGE_SIZE);
	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
	paddr = begin;
	size = end - begin;

	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
		pr_err("too small shared memory area\n");
		return ERR_PTR(-EINVAL);
	}

	va = memremap(paddr, size, MEMREMAP_WB);
	if (!va) {
		pr_err("shared memory ioremap failed\n");
		return ERR_PTR(-EINVAL);
	}
	vaddr = (unsigned long)va;

	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
					    3 /* 8 bytes aligned */);
	if (IS_ERR(rc))
		goto err_memunmap;
	priv_mgr = rc;

	vaddr += sz;
	paddr += sz;
	size -= sz;

	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
	if (IS_ERR(rc))
		goto err_free_priv_mgr;
	dmabuf_mgr = rc;

	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
	if (IS_ERR(rc))
		goto err_free_dmabuf_mgr;

	*memremaped_shm = va;

	return rc;

err_free_dmabuf_mgr:
	tee_shm_pool_mgr_destroy(dmabuf_mgr);
err_free_priv_mgr:
	tee_shm_pool_mgr_destroy(priv_mgr);
err_memunmap:
	memunmap(va);
	return rc;
}

/* Simple wrapper functions to be able to use a function pointer */
static void optee_smccc_smc(unsigned long a0, unsigned long a1,
			    unsigned long a2, unsigned long a3,
			    unsigned long a4, unsigned long a5,
			    unsigned long a6, unsigned long a7,
			    struct arm_smccc_res *res)
{
	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
}

static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
			    unsigned long a2, unsigned long a3,
			    unsigned long a4, unsigned long a5,
			    unsigned long a6, unsigned long a7,
			    struct arm_smccc_res *res)
{
	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
}

static optee_invoke_fn *get_invoke_func(struct device *dev)
{
	const char *method;

	pr_info("probing for conduit method.\n");

	if (device_property_read_string(dev, "method", &method)) {
		pr_warn("missing \"method\" property\n");
		return ERR_PTR(-ENXIO);
	}

	if (!strcmp("hvc", method))
		return optee_smccc_hvc;
	else if (!strcmp("smc", method))
		return optee_smccc_smc;

	pr_warn("invalid \"method\" property: %s\n", method);
	return ERR_PTR(-EINVAL);
}

/* optee_remove - Device Removal Routine
 * @pdev: platform device information struct
 *
 * optee_remove is called by platform subsystem to alert the driver
 * that it should release the device
 */

static int optee_remove(struct platform_device *pdev)
{
	struct optee *optee = platform_get_drvdata(pdev);

	/*
	 * Ask OP-TEE to free all cached shared memory objects to decrease
	 * reference counters and also avoid wild pointers in secure world
	 * into the old shared memory range.
	 */
	optee_disable_shm_cache(optee);

	/*
	 * The two devices have to be unregistered before we can free the
	 * other resources.
	 */
	tee_device_unregister(optee->supp_teedev);
	tee_device_unregister(optee->teedev);

	tee_shm_pool_free(optee->pool);
	if (optee->memremaped_shm)
		memunmap(optee->memremaped_shm);
	optee_wait_queue_exit(&optee->wait_queue);
	optee_supp_uninit(&optee->supp);
	mutex_destroy(&optee->call_queue.mutex);

	kfree(optee);

	return 0;
}

/* optee_shutdown - Device Removal Routine
 * @pdev: platform device information struct
 *
 * platform_shutdown is called by the platform subsystem to alert
 * the driver that a shutdown, reboot, or kexec is happening and
 * device must be disabled.
 */
static void optee_shutdown(struct platform_device *pdev)
{
	optee_disable_shm_cache(platform_get_drvdata(pdev));
}

static int optee_probe(struct platform_device *pdev)
{
	optee_invoke_fn *invoke_fn;
	struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
	struct optee *optee = NULL;
	void *memremaped_shm = NULL;
	struct tee_device *teedev;
	u32 sec_caps;
	int rc;

	/*
	 * The kernel may have crashed at the same time that all available
	 * secure world threads were suspended and we cannot reschedule the
	 * suspended threads without access to the crashed kernel's wait_queue.
	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
	 * kdump kernel.
	 */
	if (is_kdump_kernel())
		return -ENODEV;

	invoke_fn = get_invoke_func(&pdev->dev);
	if (IS_ERR(invoke_fn))
		return PTR_ERR(invoke_fn);

	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
		pr_warn("api uid mismatch\n");
		return -EINVAL;
	}

	optee_msg_get_os_revision(invoke_fn);

	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
		pr_warn("api revision mismatch\n");
		return -EINVAL;
	}

	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
		pr_warn("capabilities mismatch\n");
		return -EINVAL;
	}

	/*
	 * Try to use dynamic shared memory if possible
	 */
	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
		pool = optee_config_dyn_shm();

	/*
	 * If dynamic shared memory is not available or failed - try static one
	 */
	if (IS_ERR(pool) && (sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
		pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);

	if (IS_ERR(pool))
		return PTR_ERR(pool);

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

	optee->invoke_fn = invoke_fn;
	optee->sec_caps = sec_caps;

	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
	if (IS_ERR(teedev)) {
		rc = PTR_ERR(teedev);
		goto err;
	}
	optee->teedev = teedev;

	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
	if (IS_ERR(teedev)) {
		rc = PTR_ERR(teedev);
		goto err;
	}
	optee->supp_teedev = teedev;

	rc = tee_device_register(optee->teedev);
	if (rc)
		goto err;

	rc = tee_device_register(optee->supp_teedev);
	if (rc)
		goto err;

	mutex_init(&optee->call_queue.mutex);
	INIT_LIST_HEAD(&optee->call_queue.waiters);
	optee_wait_queue_init(&optee->wait_queue);
	optee_supp_init(&optee->supp);
	optee->memremaped_shm = memremaped_shm;
	optee->pool = pool;

	optee_enable_shm_cache(optee);

	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
		pr_info("dynamic shared memory is enabled\n");

	platform_set_drvdata(pdev, optee);

	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
	if (rc) {
		optee_remove(pdev);
		return rc;
	}

	pr_info("initialized driver\n");
	return 0;
err:
	if (optee) {
		/*
		 * tee_device_unregister() is safe to call even if the
		 * devices hasn't been registered with
		 * tee_device_register() yet.
		 */
		tee_device_unregister(optee->supp_teedev);
		tee_device_unregister(optee->teedev);
		kfree(optee);
	}
	if (pool)
		tee_shm_pool_free(pool);
	if (memremaped_shm)
		memunmap(memremaped_shm);
	return rc;
}

static const struct of_device_id optee_dt_match[] = {
	{ .compatible = "linaro,optee-tz" },
	{},
};
MODULE_DEVICE_TABLE(of, optee_dt_match);

static struct platform_driver optee_driver = {
	.probe  = optee_probe,
	.remove = optee_remove,
	.shutdown = optee_shutdown,
	.driver = {
		.name = "optee",
		.of_match_table = optee_dt_match,
	},
};
module_platform_driver(optee_driver);

MODULE_AUTHOR("Linaro");
MODULE_DESCRIPTION("OP-TEE driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:optee");