aboutsummaryrefslogtreecommitdiff
path: root/services/std_svc/spm/spci.c
blob: 44a0acd6f93c58f0712a8ffda41f24aca50e1910 (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
774
775
/*
 * Copyright (c) 2018, Arm Limited. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <assert.h>
#include <errno.h>
#include <string.h>

#include <common/debug.h>
#include <lib/el3_runtime/context_mgmt.h>
#include <lib/smccc.h>
#include <lib/spinlock.h>
#include <lib/utils.h>
#include <services/spci_svc.h>
#include <services/sprt_svc.h>
#include <smccc_helpers.h>
#include <sprt_host.h>

#include "spm_private.h"

/*******************************************************************************
 * Macros to print UUIDs.
 ******************************************************************************/
#define PRINT_UUID_FORMAT	"%08x-%08x-%08x-%08x"
#define PRINT_UUID_ARGS(x)	x[0], x[1], x[2], x[3]

/*******************************************************************************
 * Array of structs that contains information about all handles of Secure
 * Services that are currently open.
 ******************************************************************************/
typedef enum spci_handle_status {
	HANDLE_STATUS_CLOSED = 0,
	HANDLE_STATUS_OPEN,
} spci_handle_status_t;

typedef struct spci_handle {
	/* 16-bit value used as reference in all SPCI calls */
	uint16_t handle;

	/* Client ID of the client that requested the handle */
	uint16_t client_id;

	/* Current status of the handle */
	spci_handle_status_t status;

	/*
	 * Context of the Secure Partition that provides the Secure Service
	 * referenced by this handle.
	 */
	sp_context_t *sp_ctx;

	/*
	 * The same handle might be used for multiple requests, keep a reference
	 * counter of them.
	 */
	unsigned int num_active_requests;
} spci_handle_t;

static spci_handle_t spci_handles[PLAT_SPCI_HANDLES_MAX_NUM];
static spinlock_t spci_handles_lock;

/*
 * Given a handle and a client ID, return the element of the spci_handles
 * array that contains the information of the handle. It can only return open
 * handles. It returns NULL if it couldn't find the element in the array.
 */
static spci_handle_t *spci_handle_info_get(uint16_t handle, uint16_t client_id)
{
	size_t i;

	for (i = 0; i < ARRAY_SIZE(spci_handles); i++) {
		spci_handle_t *h = &(spci_handles[i]);

		/* Only check for open handles */
		if (h->status == HANDLE_STATUS_CLOSED) {
			continue;
		}

		/* Check if either the handle or the client ID are different */
		if ((h->handle != handle) || (h->client_id != client_id)) {
			continue;
		}

		return h;
	}

	return NULL;
}

/*
 * Returns a unique value for a handle. This function must be called while
 * spci_handles_lock is locked. It returns 0 on success, -1 on error.
 */
static int spci_create_handle_value(uint16_t *handle)
{
	/*
	 * Trivial implementation that relies on the fact that any handle will
	 * be closed before 2^16 more handles have been opened.
	 */
	static uint16_t handle_count;

	*handle = handle_count;

	handle_count++;

	return 0;
}

/*******************************************************************************
 * Returns a unique token for a Secure Service request.
 ******************************************************************************/
static uint32_t spci_create_token_value(void)
{
	/*
	 * Trivial implementation that relies on the fact that any response will
	 * be read before 2^32 more service requests have been done.
	 */
	static uint32_t token_count;

	return token_count++;
}

/*******************************************************************************
 * This function looks for a Secure Partition that has a Secure Service
 * identified by the given UUID. It returns a handle that the client can use to
 * access the service, and an SPCI_*** error code.
 ******************************************************************************/
static uint64_t spci_service_handle_open_poll(void *handle, u_register_t x1,
			u_register_t x2, u_register_t x3, u_register_t x4,
			u_register_t x5, u_register_t x6, u_register_t x7)
{
	unsigned int i;
	sp_context_t *sp_ptr;
	uint16_t service_handle;

	/* Bits 31:16 of w7 are reserved (MBZ). */
	assert((x7 & 0xFFFF0000U) == 0);

	uint16_t client_id = x7 & 0x0000FFFFU;
	uint32_t uuid[4] = { x1, x2, x3, x4 };

	/* Get pointer to the Secure Partition that handles this service */
	sp_ptr = spm_sp_get_by_uuid(&uuid);
	if (sp_ptr == NULL) {
		WARN("SPCI: Service requested by client 0x%04x not found\n",
		     client_id);
		WARN("SPCI:   UUID: " PRINT_UUID_FORMAT "\n",
		     PRINT_UUID_ARGS(uuid));

		SMC_RET2(handle, SPCI_NOT_PRESENT, 0);
	}

	/* Get lock of the array of handles */
	spin_lock(&spci_handles_lock);

	/*
	 * We need to record the client ID and Secure Partition that correspond
	 * to this handle. Look for the first free entry in the array.
	 */
	for (i = 0; i < PLAT_SPCI_HANDLES_MAX_NUM; i++) {
		if (spci_handles[i].status == HANDLE_STATUS_CLOSED) {
			break;
		}
	}

	if (i == PLAT_SPCI_HANDLES_MAX_NUM) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI: Can't open more handles. Client 0x%04x\n",
		     client_id);
		WARN("SPCI:   UUID: " PRINT_UUID_FORMAT "\n",
		     PRINT_UUID_ARGS(uuid));

		SMC_RET2(handle, SPCI_NO_MEMORY, 0);
	}

	/* Create new handle value */
	if (spci_create_handle_value(&service_handle) != 0) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI: Can't create a new handle value. Client 0x%04x\n",
		     client_id);
		WARN("SPCI:   UUID: " PRINT_UUID_FORMAT "\n",
		     PRINT_UUID_ARGS(uuid));

		SMC_RET2(handle, SPCI_NO_MEMORY, 0);
	}

	/* Save all information about this handle */
	spci_handles[i].status = HANDLE_STATUS_OPEN;
	spci_handles[i].client_id = client_id;
	spci_handles[i].handle = service_handle;
	spci_handles[i].num_active_requests = 0U;
	spci_handles[i].sp_ctx = sp_ptr;

	/* Release lock of the array of handles */
	spin_unlock(&spci_handles_lock);

	VERBOSE("SPCI: Service handle request by client 0x%04x: 0x%04x\n",
		client_id, service_handle);
	VERBOSE("SPCI:   UUID: " PRINT_UUID_FORMAT "\n", PRINT_UUID_ARGS(uuid));

	/* The handle is returned in the top 16 bits of x1 */
	SMC_RET2(handle, SPCI_SUCCESS, ((uint32_t)service_handle) << 16);
}

/*******************************************************************************
 * This function closes a handle that a specific client uses to access a Secure
 * Service. It returns a SPCI_*** error code.
 ******************************************************************************/
static uint64_t spci_service_handle_close(void *handle, u_register_t x1)
{
	spci_handle_t *handle_info;
	uint16_t client_id = x1 & 0x0000FFFFU;
	uint16_t service_handle = (x1 >> 16) & 0x0000FFFFU;

	spin_lock(&spci_handles_lock);

	handle_info = spci_handle_info_get(service_handle, client_id);

	if (handle_info == NULL) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI: Tried to close invalid handle 0x%04x by client 0x%04x\n",
		     service_handle, client_id);

		SMC_RET1(handle, SPCI_INVALID_PARAMETER);
	}

	if (handle_info->status != HANDLE_STATUS_OPEN) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI: Tried to close handle 0x%04x by client 0x%04x in status %d\n",
			service_handle, client_id, handle_info->status);

		SMC_RET1(handle, SPCI_INVALID_PARAMETER);
	}

	if (handle_info->num_active_requests != 0U) {
		spin_unlock(&spci_handles_lock);

		/* A handle can't be closed if there are requests left */
		WARN("SPCI: Tried to close handle 0x%04x by client 0x%04x with %d requests left\n",
			service_handle, client_id,
			handle_info->num_active_requests);

		SMC_RET1(handle, SPCI_BUSY);
	}

	memset(handle_info, 0, sizeof(spci_handle_t));

	handle_info->status = HANDLE_STATUS_CLOSED;

	spin_unlock(&spci_handles_lock);

	VERBOSE("SPCI: Closed handle 0x%04x by client 0x%04x.\n",
		service_handle, client_id);

	SMC_RET1(handle, SPCI_SUCCESS);
}

/*******************************************************************************
 * This function requests a Secure Service from a given handle and client ID.
 ******************************************************************************/
static uint64_t spci_service_request_blocking(void *handle,
			uint32_t smc_fid, u_register_t x1, u_register_t x2,
			u_register_t x3, u_register_t x4, u_register_t x5,
			u_register_t x6, u_register_t x7)
{
	spci_handle_t *handle_info;
	sp_context_t *sp_ctx;
	cpu_context_t *cpu_ctx;
	uint32_t rx0;
	u_register_t rx1, rx2, rx3;
	uint16_t request_handle, client_id;

	/* Get handle array lock */
	spin_lock(&spci_handles_lock);

	/* Get pointer to struct of this open handle and client ID. */
	request_handle = (x7 >> 16U) & 0x0000FFFFU;
	client_id = x7 & 0x0000FFFFU;

	handle_info = spci_handle_info_get(request_handle, client_id);
	if (handle_info == NULL) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI_SERVICE_TUN_REQUEST_BLOCKING: Not found.\n");
		WARN("  Handle 0x%04x. Client ID 0x%04x\n", request_handle,
		     client_id);

		SMC_RET1(handle, SPCI_BUSY);
	}

	/* Get pointer to the Secure Partition that handles the service */
	sp_ctx = handle_info->sp_ctx;
	assert(sp_ctx != NULL);
	cpu_ctx = &(sp_ctx->cpu_ctx);

	/* Blocking requests are only allowed if the queue is empty */
	if (handle_info->num_active_requests > 0) {
		spin_unlock(&spci_handles_lock);

		SMC_RET1(handle, SPCI_BUSY);
	}

	if (spm_sp_request_increase_if_zero(sp_ctx) == -1) {
		spin_unlock(&spci_handles_lock);

		SMC_RET1(handle, SPCI_BUSY);
	}

	/* Prevent this handle from being closed */
	handle_info->num_active_requests += 1;

	/* Release handle lock */
	spin_unlock(&spci_handles_lock);

	/* Save the Normal world context */
	cm_el1_sysregs_context_save(NON_SECURE);

	/* Wait until the Secure Partition is idle and set it to busy. */
	sp_state_wait_switch(sp_ctx, SP_STATE_IDLE, SP_STATE_BUSY);

	/* Pass arguments to the Secure Partition */
	struct sprt_queue_entry_message message = {
		.type = SPRT_MSG_TYPE_SERVICE_TUN_REQUEST,
		.client_id = client_id,
		.service_handle = request_handle,
		.session_id = x6,
		.token = 0, /* No token needed for blocking requests */
		.args = {smc_fid, x1, x2, x3, x4, x5}
	};

	spin_lock(&(sp_ctx->spm_sp_buffer_lock));
	int rc = sprt_push_message((void *)sp_ctx->spm_sp_buffer_base, &message,
				   SPRT_QUEUE_NUM_BLOCKING);
	spin_unlock(&(sp_ctx->spm_sp_buffer_lock));
	if (rc != 0) {
		/*
		 * This shouldn't happen, blocking requests can only be made if
		 * the request queue is empty.
		 */
		assert(rc == -ENOMEM);
		ERROR("SPCI_SERVICE_TUN_REQUEST_BLOCKING: Queue is full.\n");
		panic();
	}

	/* Jump to the Secure Partition. */
	rx0 = spm_sp_synchronous_entry(sp_ctx, 0);

	/* Verify returned value */
	if (rx0 != SPRT_PUT_RESPONSE_AARCH64) {
		ERROR("SPM: %s: Unexpected x0 value 0x%x\n", __func__, rx0);
		panic();
	}

	rx1 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X3);
	rx2 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X4);
	rx3 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X5);

	/* Flag Secure Partition as idle. */
	assert(sp_ctx->state == SP_STATE_BUSY);
	sp_state_set(sp_ctx, SP_STATE_IDLE);

	/* Decrease count of requests. */
	spin_lock(&spci_handles_lock);
	handle_info->num_active_requests -= 1;
	spin_unlock(&spci_handles_lock);
	spm_sp_request_decrease(sp_ctx);

	/* Restore non-secure state */
	cm_el1_sysregs_context_restore(NON_SECURE);
	cm_set_next_eret_context(NON_SECURE);

	SMC_RET4(handle, SPCI_SUCCESS, rx1, rx2, rx3);
}

/*******************************************************************************
 * This function requests a Secure Service from a given handle and client ID.
 ******************************************************************************/
static uint64_t spci_service_request_start(void *handle,
			uint32_t smc_fid, u_register_t x1, u_register_t x2,
			u_register_t x3, u_register_t x4, u_register_t x5,
			u_register_t x6, u_register_t x7)
{
	spci_handle_t *handle_info;
	sp_context_t *sp_ctx;
	cpu_context_t *cpu_ctx;
	uint16_t request_handle, client_id;
	uint32_t token;

	/* Get handle array lock */
	spin_lock(&spci_handles_lock);

	/* Get pointer to struct of this open handle and client ID. */
	request_handle = (x7 >> 16U) & 0x0000FFFFU;
	client_id = x7 & 0x0000FFFFU;

	handle_info = spci_handle_info_get(request_handle, client_id);
	if (handle_info == NULL) {
		spin_unlock(&spci_handles_lock);

		WARN("SPCI_SERVICE_TUN_REQUEST_START: Not found.\n"
		     "  Handle 0x%04x. Client ID 0x%04x\n", request_handle,
		     client_id);

		SMC_RET1(handle, SPCI_INVALID_PARAMETER);
	}

	/* Get pointer to the Secure Partition that handles the service */
	sp_ctx = handle_info->sp_ctx;
	assert(sp_ctx != NULL);
	cpu_ctx = &(sp_ctx->cpu_ctx);

	/* Prevent this handle from being closed */
	handle_info->num_active_requests += 1;

	spm_sp_request_increase(sp_ctx);

	/* Create new token for this request */
	token = spci_create_token_value();

	/* Release handle lock */
	spin_unlock(&spci_handles_lock);

	/* Pass arguments to the Secure Partition */
	struct sprt_queue_entry_message message = {
		.type = SPRT_MSG_TYPE_SERVICE_TUN_REQUEST,
		.client_id = client_id,
		.service_handle = request_handle,
		.session_id = x6,
		.token = token,
		.args = {smc_fid, x1, x2, x3, x4, x5}
	};

	spin_lock(&(sp_ctx->spm_sp_buffer_lock));
	int rc = sprt_push_message((void *)sp_ctx->spm_sp_buffer_base, &message,
				   SPRT_QUEUE_NUM_NON_BLOCKING);
	spin_unlock(&(sp_ctx->spm_sp_buffer_lock));
	if (rc != 0) {
		WARN("SPCI_SERVICE_TUN_REQUEST_START: SPRT queue full.\n"
		     "  Handle 0x%04x. Client ID 0x%04x\n", request_handle,
		     client_id);
		SMC_RET1(handle, SPCI_NO_MEMORY);
	}

	/* Try to enter the partition. If it's not possible, simply return. */
	if (sp_state_try_switch(sp_ctx, SP_STATE_IDLE, SP_STATE_BUSY) != 0) {
		SMC_RET2(handle, SPCI_SUCCESS, token);
	}

	/* Save the Normal world context */
	cm_el1_sysregs_context_save(NON_SECURE);

	/*
	 * This request is non-blocking and needs to be interruptible by
	 * non-secure interrupts. Enable their routing to EL3 during the
	 * processing of the Secure Partition's service on this core.
	 */

	/* Jump to the Secure Partition. */
	uint64_t ret = spm_sp_synchronous_entry(sp_ctx, 1);

	/* Verify returned values */
	if (ret == SPRT_PUT_RESPONSE_AARCH64) {
		uint32_t token;
		uint64_t rx1, rx2, rx3, x6;

		token = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X1);
		rx1 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X3);
		rx2 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X4);
		rx3 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X5);
		x6 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X6);

		uint16_t client_id = x6 & 0xFFFFU;
		uint16_t service_handle = x6 >> 16;

		int rc = spm_response_add(client_id, service_handle, token,
					  rx1, rx2, rx3);
		if (rc != 0) {
			/*
			 * This is error fatal because we can't return to the SP
			 * from this SMC. The SP has crashed.
			 */
			panic();
		}
	} else if ((ret != SPRT_YIELD_AARCH64) &&
		   (ret != SPM_SECURE_PARTITION_PREEMPTED)) {
		ERROR("SPM: %s: Unexpected x0 value 0x%llx\n", __func__, ret);
		panic();
	}

	/* Flag Secure Partition as idle. */
	assert(sp_ctx->state == SP_STATE_BUSY);
	sp_state_set(sp_ctx, SP_STATE_IDLE);

	/* Restore non-secure state */
	cm_el1_sysregs_context_restore(NON_SECURE);
	cm_set_next_eret_context(NON_SECURE);

	SMC_RET2(handle, SPCI_SUCCESS, token);
}

/*******************************************************************************
 * This function returns the response of a Secure Service given a handle, a
 * client ID and a token. If not available, it will schedule a Secure Partition
 * and give it CPU time.
 ******************************************************************************/
static uint64_t spci_service_request_resume(void *handle, u_register_t x1,
					    u_register_t x7)
{
	int rc;
	u_register_t rx1 = 0, rx2 = 0, rx3 = 0;
	spci_handle_t *handle_info;
	sp_context_t *sp_ctx;
	cpu_context_t *cpu_ctx;
	uint32_t token = (uint32_t) x1;
	uint16_t client_id = x7 & 0x0000FFFF;
	uint16_t service_handle = (x7 >> 16) & 0x0000FFFF;

	/* Get pointer to struct of this open handle and client ID. */
	spin_lock(&spci_handles_lock);

	handle_info = spci_handle_info_get(service_handle, client_id);
	if (handle_info == NULL) {
		spin_unlock(&spci_handles_lock);
		WARN("SPCI_SERVICE_REQUEST_RESUME: Not found.\n"
		     "Handle 0x%04x. Client ID 0x%04x, Token 0x%08x.\n",
		     client_id, service_handle, token);

		SMC_RET1(handle, SPCI_INVALID_PARAMETER);
	}

	/* Get pointer to the Secure Partition that handles the service */
	sp_ctx = handle_info->sp_ctx;
	assert(sp_ctx != NULL);
	cpu_ctx = &(sp_ctx->cpu_ctx);

	spin_unlock(&spci_handles_lock);

	/* Look for a valid response in the global queue */
	rc = spm_response_get(client_id, service_handle, token,
			      &rx1, &rx2, &rx3);
	if (rc == 0) {
		/* Decrease request count */
		spin_lock(&spci_handles_lock);
		handle_info->num_active_requests -= 1;
		spin_unlock(&spci_handles_lock);
		spm_sp_request_decrease(sp_ctx);

		SMC_RET4(handle, SPCI_SUCCESS, rx1, rx2, rx3);
	}

	/* Try to enter the partition. If it's not possible, simply return. */
	if (sp_state_try_switch(sp_ctx, SP_STATE_IDLE, SP_STATE_BUSY) != 0) {
		SMC_RET1(handle, SPCI_QUEUED);
	}

	/* Save the Normal world context */
	cm_el1_sysregs_context_save(NON_SECURE);

	/*
	 * This request is non-blocking and needs to be interruptible by
	 * non-secure interrupts. Enable their routing to EL3 during the
	 * processing of the Secure Partition's service on this core.
	 */

	/* Jump to the Secure Partition. */
	uint64_t ret = spm_sp_synchronous_entry(sp_ctx, 1);

	/* Verify returned values */
	if (ret == SPRT_PUT_RESPONSE_AARCH64) {
		uint32_t token;
		uint64_t rx1, rx2, rx3, x6;

		token = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X1);
		rx1 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X3);
		rx2 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X4);
		rx3 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X5);
		x6 = read_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X6);

		uint16_t client_id = x6 & 0xFFFFU;
		uint16_t service_handle = x6 >> 16;

		int rc = spm_response_add(client_id, service_handle, token,
					  rx1, rx2, rx3);
		if (rc != 0) {
			/*
			 * This is error fatal because we can't return to the SP
			 * from this SMC. The SP has crashed.
			 */
			panic();
		}
	} else if ((ret != SPRT_YIELD_AARCH64) &&
		   (ret != SPM_SECURE_PARTITION_PREEMPTED)) {
		ERROR("SPM: %s: Unexpected x0 value 0x%llx\n", __func__, ret);
		panic();
	}

	/* Flag Secure Partition as idle. */
	assert(sp_ctx->state == SP_STATE_BUSY);
	sp_state_set(sp_ctx, SP_STATE_IDLE);

	/* Restore non-secure state */
	cm_el1_sysregs_context_restore(NON_SECURE);
	cm_set_next_eret_context(NON_SECURE);

	/* Look for a valid response in the global queue */
	rc = spm_response_get(client_id, service_handle, token,
			      &rx1, &rx2, &rx3);
	if (rc != 0) {
		SMC_RET1(handle, SPCI_QUEUED);
	}

	/* Decrease request count */
	spin_lock(&spci_handles_lock);
	handle_info->num_active_requests -= 1;
	spin_unlock(&spci_handles_lock);
	spm_sp_request_decrease(sp_ctx);

	/* Return response */
	SMC_RET4(handle, SPCI_SUCCESS, rx1, rx2, rx3);
}

/*******************************************************************************
 * This function returns the response of a Secure Service given a handle, a
 * client ID and a token.
 ******************************************************************************/
static uint64_t spci_service_get_response(void *handle, u_register_t x1,
					    u_register_t x7)

{
	int rc;
	u_register_t rx1 = 0, rx2 = 0, rx3 = 0;
	spci_handle_t *handle_info;
	uint32_t token = (uint32_t) x1;
	uint16_t client_id = x7 & 0x0000FFFF;
	uint16_t service_handle = (x7 >> 16) & 0x0000FFFF;

	/* Get pointer to struct of this open handle and client ID. */

	spin_lock(&spci_handles_lock);

	handle_info = spci_handle_info_get(service_handle, client_id);
	if (handle_info == NULL) {
		spin_unlock(&spci_handles_lock);
		WARN("SPCI_SERVICE_GET_RESPONSE: Not found.\n"
		     "Handle 0x%04x. Client ID 0x%04x, Token 0x%08x.\n",
		     client_id, service_handle, token);

		SMC_RET1(handle, SPCI_INVALID_PARAMETER);
	}

	spin_unlock(&spci_handles_lock);

	/* Look for a valid response in the global queue */
	rc = spm_response_get(client_id, service_handle, token,
			      &rx1, &rx2, &rx3);

	if (rc != 0) {
		SMC_RET1(handle, SPCI_QUEUED);
	}

	/* Decrease request count */
	spin_lock(&spci_handles_lock);
	handle_info->num_active_requests -= 1;
	sp_context_t *sp_ctx;
	sp_ctx = handle_info->sp_ctx;
	spin_unlock(&spci_handles_lock);
	spm_sp_request_decrease(sp_ctx);

	/* Return response */
	SMC_RET4(handle, SPCI_SUCCESS, rx1, rx2, rx3);
}

/*******************************************************************************
 * This function handles all SMCs in the range reserved for SPCI.
 ******************************************************************************/
uint64_t spci_smc_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2,
			  uint64_t x3, uint64_t x4, void *cookie, void *handle,
			  uint64_t flags)
{
	uint32_t spci_fid;

	/* SPCI only supported from the Non-secure world for now */
	if (is_caller_non_secure(flags) == SMC_FROM_SECURE) {
		SMC_RET1(handle, SMC_UNK);
	}

	if ((smc_fid & SPCI_FID_TUN_FLAG) == 0) {

		/* Miscellaneous calls */

		spci_fid = (smc_fid >> SPCI_FID_MISC_SHIFT) & SPCI_FID_MISC_MASK;

		switch (spci_fid) {

		case SPCI_FID_VERSION:
			SMC_RET1(handle, SPCI_VERSION_COMPILED);

		case SPCI_FID_SERVICE_HANDLE_OPEN:
		{
			if ((smc_fid & SPCI_SERVICE_HANDLE_OPEN_NOTIFY_BIT) != 0) {
				/* Not supported for now */
				WARN("SPCI_SERVICE_HANDLE_OPEN_NOTIFY not supported.\n");
				SMC_RET1(handle, SPCI_INVALID_PARAMETER);
			}

			uint64_t x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
			uint64_t x6 = SMC_GET_GP(handle, CTX_GPREG_X6);
			uint64_t x7 = SMC_GET_GP(handle, CTX_GPREG_X7);

			return spci_service_handle_open_poll(handle, x1, x2, x3,
							     x4, x5, x6, x7);
		}
		case SPCI_FID_SERVICE_HANDLE_CLOSE:
			return spci_service_handle_close(handle, x1);

		case SPCI_FID_SERVICE_REQUEST_BLOCKING:
		{
			uint64_t x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
			uint64_t x6 = SMC_GET_GP(handle, CTX_GPREG_X6);
			uint64_t x7 = SMC_GET_GP(handle, CTX_GPREG_X7);

			return spci_service_request_blocking(handle,
					smc_fid, x1, x2, x3, x4, x5, x6, x7);
		}

		case SPCI_FID_SERVICE_REQUEST_START:
		{
			uint64_t x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
			uint64_t x6 = SMC_GET_GP(handle, CTX_GPREG_X6);
			uint64_t x7 = SMC_GET_GP(handle, CTX_GPREG_X7);

			return spci_service_request_start(handle,
					smc_fid, x1, x2, x3, x4, x5, x6, x7);
		}

		case SPCI_FID_SERVICE_GET_RESPONSE:
		{
			uint64_t x7 = SMC_GET_GP(handle, CTX_GPREG_X7);

			return spci_service_get_response(handle, x1, x7);
		}

		default:
			break;
		}

	} else {

		/* Tunneled calls */

		spci_fid = (smc_fid >> SPCI_FID_TUN_SHIFT) & SPCI_FID_TUN_MASK;

		switch (spci_fid) {

		case SPCI_FID_SERVICE_REQUEST_RESUME:
		{
			uint64_t x7 = SMC_GET_GP(handle, CTX_GPREG_X7);

			return spci_service_request_resume(handle, x1, x7);
		}

		default:
			break;
		}
	}

	WARN("SPCI: Unsupported call 0x%08x\n", smc_fid);
	SMC_RET1(handle, SPCI_NOT_SUPPORTED);
}