xref: /rk3399_ARM-atf/services/std_svc/spmd/spmd_main.c (revision 75e1dfa038fd2f88959dd7b618984e54ee4fa594)
1 /*
2  * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <errno.h>
9 #include <string.h>
10 
11 #include <arch_helpers.h>
12 #include <arch/aarch64/arch_features.h>
13 #include <bl31/bl31.h>
14 #include <common/debug.h>
15 #include <common/runtime_svc.h>
16 #include <lib/el3_runtime/context_mgmt.h>
17 #include <lib/smccc.h>
18 #include <lib/spinlock.h>
19 #include <lib/utils.h>
20 #include <plat/common/common_def.h>
21 #include <plat/common/platform.h>
22 #include <platform_def.h>
23 #include <services/ffa_svc.h>
24 #include <services/spmd_svc.h>
25 #include <smccc_helpers.h>
26 #include "spmd_private.h"
27 
28 /*******************************************************************************
29  * SPM Core context information.
30  ******************************************************************************/
31 static spmd_spm_core_context_t spm_core_context[PLATFORM_CORE_COUNT];
32 
33 /*******************************************************************************
34  * SPM Core attribute information read from its manifest.
35  ******************************************************************************/
36 static spmc_manifest_attribute_t spmc_attrs;
37 
38 /*******************************************************************************
39  * SPM Core entry point information. Discovered on the primary core and reused
40  * on secondary cores.
41  ******************************************************************************/
42 static entry_point_info_t *spmc_ep_info;
43 
44 /*******************************************************************************
45  * SPM Core context on CPU based on mpidr.
46  ******************************************************************************/
47 spmd_spm_core_context_t *spmd_get_context_by_mpidr(uint64_t mpidr)
48 {
49 	return &spm_core_context[plat_core_pos_by_mpidr(mpidr)];
50 }
51 
52 /*******************************************************************************
53  * SPM Core context on current CPU get helper.
54  ******************************************************************************/
55 spmd_spm_core_context_t *spmd_get_context(void)
56 {
57 	return spmd_get_context_by_mpidr(read_mpidr());
58 }
59 
60 /*******************************************************************************
61  * SPM Core entry point information get helper.
62  ******************************************************************************/
63 entry_point_info_t *spmd_spmc_ep_info_get(void)
64 {
65 	return spmc_ep_info;
66 }
67 
68 /*******************************************************************************
69  * SPM Core ID getter.
70  ******************************************************************************/
71 uint16_t spmd_spmc_id_get(void)
72 {
73 	return spmc_attrs.spmc_id;
74 }
75 
76 /*******************************************************************************
77  * Static function declaration.
78  ******************************************************************************/
79 static int32_t spmd_init(void);
80 static int spmd_spmc_init(void *pm_addr);
81 static uint64_t spmd_ffa_error_return(void *handle,
82 				       int error_code);
83 static uint64_t spmd_smc_forward(uint32_t smc_fid,
84 				 bool secure_origin,
85 				 uint64_t x1,
86 				 uint64_t x2,
87 				 uint64_t x3,
88 				 uint64_t x4,
89 				 void *handle);
90 
91 /*******************************************************************************
92  * This function takes an SPMC context pointer and performs a synchronous
93  * SPMC entry.
94  ******************************************************************************/
95 uint64_t spmd_spm_core_sync_entry(spmd_spm_core_context_t *spmc_ctx)
96 {
97 	uint64_t rc;
98 
99 	assert(spmc_ctx != NULL);
100 
101 	cm_set_context(&(spmc_ctx->cpu_ctx), SECURE);
102 
103 	/* Restore the context assigned above */
104 	cm_el1_sysregs_context_restore(SECURE);
105 #if SPMD_SPM_AT_SEL2
106 	cm_el2_sysregs_context_restore(SECURE);
107 #endif
108 	cm_set_next_eret_context(SECURE);
109 
110 	/* Enter SPMC */
111 	rc = spmd_spm_core_enter(&spmc_ctx->c_rt_ctx);
112 
113 	/* Save secure state */
114 	cm_el1_sysregs_context_save(SECURE);
115 #if SPMD_SPM_AT_SEL2
116 	cm_el2_sysregs_context_save(SECURE);
117 #endif
118 
119 	return rc;
120 }
121 
122 /*******************************************************************************
123  * This function returns to the place where spmd_spm_core_sync_entry() was
124  * called originally.
125  ******************************************************************************/
126 __dead2 void spmd_spm_core_sync_exit(uint64_t rc)
127 {
128 	spmd_spm_core_context_t *ctx = spmd_get_context();
129 
130 	/* Get current CPU context from SPMC context */
131 	assert(cm_get_context(SECURE) == &(ctx->cpu_ctx));
132 
133 	/*
134 	 * The SPMD must have initiated the original request through a
135 	 * synchronous entry into SPMC. Jump back to the original C runtime
136 	 * context with the value of rc in x0;
137 	 */
138 	spmd_spm_core_exit(ctx->c_rt_ctx, rc);
139 
140 	panic();
141 }
142 
143 /*******************************************************************************
144  * Jump to the SPM Core for the first time.
145  ******************************************************************************/
146 static int32_t spmd_init(void)
147 {
148 	spmd_spm_core_context_t *ctx = spmd_get_context();
149 	uint64_t rc;
150 	unsigned int linear_id = plat_my_core_pos();
151 	unsigned int core_id;
152 
153 	VERBOSE("SPM Core init start.\n");
154 	ctx->state = SPMC_STATE_ON_PENDING;
155 
156 	/* Set the SPMC context state on other CPUs to OFF */
157 	for (core_id = 0U; core_id < PLATFORM_CORE_COUNT; core_id++) {
158 		if (core_id != linear_id) {
159 			spm_core_context[core_id].state = SPMC_STATE_OFF;
160 			spm_core_context[core_id].secondary_ep.entry_point = 0UL;
161 		}
162 	}
163 
164 	rc = spmd_spm_core_sync_entry(ctx);
165 	if (rc != 0ULL) {
166 		ERROR("SPMC initialisation failed 0x%llx\n", rc);
167 		return 0;
168 	}
169 
170 	ctx->state = SPMC_STATE_ON;
171 
172 	VERBOSE("SPM Core init end.\n");
173 
174 	return 1;
175 }
176 
177 /*******************************************************************************
178  * Loads SPMC manifest and inits SPMC.
179  ******************************************************************************/
180 static int spmd_spmc_init(void *pm_addr)
181 {
182 	spmd_spm_core_context_t *spm_ctx = spmd_get_context();
183 	uint32_t ep_attr;
184 	int rc;
185 
186 	/* Load the SPM Core manifest */
187 	rc = plat_spm_core_manifest_load(&spmc_attrs, pm_addr);
188 	if (rc != 0) {
189 		WARN("No or invalid SPM Core manifest image provided by BL2\n");
190 		return rc;
191 	}
192 
193 	/*
194 	 * Ensure that the SPM Core version is compatible with the SPM
195 	 * Dispatcher version.
196 	 */
197 	if ((spmc_attrs.major_version != FFA_VERSION_MAJOR) ||
198 	    (spmc_attrs.minor_version > FFA_VERSION_MINOR)) {
199 		WARN("Unsupported FFA version (%u.%u)\n",
200 		     spmc_attrs.major_version, spmc_attrs.minor_version);
201 		return -EINVAL;
202 	}
203 
204 	VERBOSE("FFA version (%u.%u)\n", spmc_attrs.major_version,
205 	     spmc_attrs.minor_version);
206 
207 	VERBOSE("SPM Core run time EL%x.\n",
208 	     SPMD_SPM_AT_SEL2 ? MODE_EL2 : MODE_EL1);
209 
210 	/* Validate the SPMC ID, Ensure high bit is set */
211 	if (((spmc_attrs.spmc_id >> SPMC_SECURE_ID_SHIFT) &
212 			SPMC_SECURE_ID_MASK) == 0U) {
213 		WARN("Invalid ID (0x%x) for SPMC.\n", spmc_attrs.spmc_id);
214 		return -EINVAL;
215 	}
216 
217 	/* Validate the SPM Core execution state */
218 	if ((spmc_attrs.exec_state != MODE_RW_64) &&
219 	    (spmc_attrs.exec_state != MODE_RW_32)) {
220 		WARN("Unsupported %s%x.\n", "SPM Core execution state 0x",
221 		     spmc_attrs.exec_state);
222 		return -EINVAL;
223 	}
224 
225 	VERBOSE("%s%x.\n", "SPM Core execution state 0x",
226 		spmc_attrs.exec_state);
227 
228 #if SPMD_SPM_AT_SEL2
229 	/* Ensure manifest has not requested AArch32 state in S-EL2 */
230 	if (spmc_attrs.exec_state == MODE_RW_32) {
231 		WARN("AArch32 state at S-EL2 is not supported.\n");
232 		return -EINVAL;
233 	}
234 
235 	/*
236 	 * Check if S-EL2 is supported on this system if S-EL2
237 	 * is required for SPM
238 	 */
239 	if (!is_armv8_4_sel2_present()) {
240 		WARN("SPM Core run time S-EL2 is not supported.\n");
241 		return -EINVAL;
242 	}
243 #endif /* SPMD_SPM_AT_SEL2 */
244 
245 	/* Initialise an entrypoint to set up the CPU context */
246 	ep_attr = SECURE | EP_ST_ENABLE;
247 	if ((read_sctlr_el3() & SCTLR_EE_BIT) != 0ULL) {
248 		ep_attr |= EP_EE_BIG;
249 	}
250 
251 	SET_PARAM_HEAD(spmc_ep_info, PARAM_EP, VERSION_1, ep_attr);
252 
253 	/*
254 	 * Populate SPSR for SPM Core based upon validated parameters from the
255 	 * manifest.
256 	 */
257 	if (spmc_attrs.exec_state == MODE_RW_32) {
258 		spmc_ep_info->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM,
259 						 SPSR_E_LITTLE,
260 						 DAIF_FIQ_BIT |
261 						 DAIF_IRQ_BIT |
262 						 DAIF_ABT_BIT);
263 	} else {
264 
265 #if SPMD_SPM_AT_SEL2
266 		static const uint32_t runtime_el = MODE_EL2;
267 #else
268 		static const uint32_t runtime_el = MODE_EL1;
269 #endif
270 		spmc_ep_info->spsr = SPSR_64(runtime_el,
271 					     MODE_SP_ELX,
272 					     DISABLE_ALL_EXCEPTIONS);
273 	}
274 
275 	/* Initialise SPM Core context with this entry point information */
276 	cm_setup_context(&spm_ctx->cpu_ctx, spmc_ep_info);
277 
278 	/* Reuse PSCI affinity states to mark this SPMC context as off */
279 	spm_ctx->state = AFF_STATE_OFF;
280 
281 	INFO("SPM Core setup done.\n");
282 
283 	/* Register power management hooks with PSCI */
284 	psci_register_spd_pm_hook(&spmd_pm);
285 
286 	/* Register init function for deferred init. */
287 	bl31_register_bl32_init(&spmd_init);
288 
289 	return 0;
290 }
291 
292 /*******************************************************************************
293  * Initialize context of SPM Core.
294  ******************************************************************************/
295 int spmd_setup(void)
296 {
297 	void *spmc_manifest;
298 	int rc;
299 
300 	spmc_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
301 	if (spmc_ep_info == NULL) {
302 		WARN("No SPM Core image provided by BL2 boot loader.\n");
303 		return -EINVAL;
304 	}
305 
306 	/* Under no circumstances will this parameter be 0 */
307 	assert(spmc_ep_info->pc != 0ULL);
308 
309 	/*
310 	 * Check if BL32 ep_info has a reference to 'tos_fw_config'. This will
311 	 * be used as a manifest for the SPM Core at the next lower EL/mode.
312 	 */
313 	spmc_manifest = (void *)spmc_ep_info->args.arg0;
314 	if (spmc_manifest == NULL) {
315 		ERROR("Invalid or absent SPM Core manifest.\n");
316 		return -EINVAL;
317 	}
318 
319 	/* Load manifest, init SPMC */
320 	rc = spmd_spmc_init(spmc_manifest);
321 	if (rc != 0) {
322 		WARN("Booting device without SPM initialization.\n");
323 	}
324 
325 	return rc;
326 }
327 
328 /*******************************************************************************
329  * Forward SMC to the other security state
330  ******************************************************************************/
331 static uint64_t spmd_smc_forward(uint32_t smc_fid,
332 				 bool secure_origin,
333 				 uint64_t x1,
334 				 uint64_t x2,
335 				 uint64_t x3,
336 				 uint64_t x4,
337 				 void *handle)
338 {
339 	unsigned int secure_state_in = (secure_origin) ? SECURE : NON_SECURE;
340 	unsigned int secure_state_out = (!secure_origin) ? SECURE : NON_SECURE;
341 
342 	/* Save incoming security state */
343 	cm_el1_sysregs_context_save(secure_state_in);
344 #if SPMD_SPM_AT_SEL2
345 	cm_el2_sysregs_context_save(secure_state_in);
346 #endif
347 
348 	/* Restore outgoing security state */
349 	cm_el1_sysregs_context_restore(secure_state_out);
350 #if SPMD_SPM_AT_SEL2
351 	cm_el2_sysregs_context_restore(secure_state_out);
352 #endif
353 	cm_set_next_eret_context(secure_state_out);
354 
355 	SMC_RET8(cm_get_context(secure_state_out), smc_fid, x1, x2, x3, x4,
356 			SMC_GET_GP(handle, CTX_GPREG_X5),
357 			SMC_GET_GP(handle, CTX_GPREG_X6),
358 			SMC_GET_GP(handle, CTX_GPREG_X7));
359 }
360 
361 /*******************************************************************************
362  * Return FFA_ERROR with specified error code
363  ******************************************************************************/
364 static uint64_t spmd_ffa_error_return(void *handle, int error_code)
365 {
366 	SMC_RET8(handle, FFA_ERROR,
367 		 FFA_TARGET_INFO_MBZ, error_code,
368 		 FFA_PARAM_MBZ, FFA_PARAM_MBZ, FFA_PARAM_MBZ,
369 		 FFA_PARAM_MBZ, FFA_PARAM_MBZ);
370 }
371 
372 /*******************************************************************************
373  * spmd_check_address_in_binary_image
374  ******************************************************************************/
375 bool spmd_check_address_in_binary_image(uint64_t address)
376 {
377 	assert(!check_uptr_overflow(spmc_attrs.load_address, spmc_attrs.binary_size));
378 
379 	return ((address >= spmc_attrs.load_address) &&
380 		(address < (spmc_attrs.load_address + spmc_attrs.binary_size)));
381 }
382 
383 /******************************************************************************
384  * spmd_is_spmc_message
385  *****************************************************************************/
386 static bool spmd_is_spmc_message(unsigned int ep)
387 {
388 	return ((ffa_endpoint_destination(ep) == SPMD_DIRECT_MSG_ENDPOINT_ID)
389 		&& (ffa_endpoint_source(ep) == spmc_attrs.spmc_id));
390 }
391 
392 /******************************************************************************
393  * spmd_handle_spmc_message
394  *****************************************************************************/
395 static int spmd_handle_spmc_message(unsigned long long msg,
396 		unsigned long long parm1, unsigned long long parm2,
397 		unsigned long long parm3, unsigned long long parm4)
398 {
399 	VERBOSE("%s %llx %llx %llx %llx %llx\n", __func__,
400 		msg, parm1, parm2, parm3, parm4);
401 
402 	switch (msg) {
403 	case SPMD_DIRECT_MSG_SET_ENTRY_POINT:
404 		return spmd_pm_secondary_core_set_ep(parm1, parm2, parm3);
405 	default:
406 		break;
407 	}
408 
409 	return -EINVAL;
410 }
411 
412 /*******************************************************************************
413  * This function handles all SMCs in the range reserved for FFA. Each call is
414  * either forwarded to the other security state or handled by the SPM dispatcher
415  ******************************************************************************/
416 uint64_t spmd_smc_handler(uint32_t smc_fid,
417 			  uint64_t x1,
418 			  uint64_t x2,
419 			  uint64_t x3,
420 			  uint64_t x4,
421 			  void *cookie,
422 			  void *handle,
423 			  uint64_t flags)
424 {
425 	spmd_spm_core_context_t *ctx = spmd_get_context();
426 	bool secure_origin;
427 	int32_t ret;
428 	uint32_t input_version;
429 
430 	/* Determine which security state this SMC originated from */
431 	secure_origin = is_caller_secure(flags);
432 
433 	INFO("SPM: 0x%x 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
434 	     smc_fid, x1, x2, x3, x4, SMC_GET_GP(handle, CTX_GPREG_X5),
435 	     SMC_GET_GP(handle, CTX_GPREG_X6),
436 	     SMC_GET_GP(handle, CTX_GPREG_X7));
437 
438 	switch (smc_fid) {
439 	case FFA_ERROR:
440 		/*
441 		 * Check if this is the first invocation of this interface on
442 		 * this CPU. If so, then indicate that the SPM Core initialised
443 		 * unsuccessfully.
444 		 */
445 		if (secure_origin && (ctx->state == SPMC_STATE_ON_PENDING)) {
446 			spmd_spm_core_sync_exit(x2);
447 		}
448 
449 		return spmd_smc_forward(smc_fid, secure_origin,
450 					x1, x2, x3, x4, handle);
451 		break; /* not reached */
452 
453 	case FFA_VERSION:
454 		input_version = (uint32_t)(0xFFFFFFFF & x1);
455 		/*
456 		 * If caller is secure and SPMC was initialized,
457 		 * return FFA_VERSION of SPMD.
458 		 * If caller is non secure and SPMC was initialized,
459 		 * return SPMC's version.
460 		 * Sanity check to "input_version".
461 		 */
462 		if ((input_version & FFA_VERSION_BIT31_MASK) ||
463 			(ctx->state == SPMC_STATE_RESET)) {
464 			ret = FFA_ERROR_NOT_SUPPORTED;
465 		} else if (!secure_origin) {
466 			ret = MAKE_FFA_VERSION(spmc_attrs.major_version, spmc_attrs.minor_version);
467 		} else {
468 			ret = MAKE_FFA_VERSION(FFA_VERSION_MAJOR, FFA_VERSION_MINOR);
469 		}
470 
471 		SMC_RET8(handle, ret, FFA_TARGET_INFO_MBZ, FFA_TARGET_INFO_MBZ,
472 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ, FFA_PARAM_MBZ,
473 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ);
474 		break; /* not reached */
475 
476 	case FFA_FEATURES:
477 		/*
478 		 * This is an optional interface. Do the minimal checks and
479 		 * forward to SPM Core which will handle it if implemented.
480 		 */
481 
482 		/*
483 		 * Check if x1 holds a valid FFA fid. This is an
484 		 * optimization.
485 		 */
486 		if (!is_ffa_fid(x1)) {
487 			return spmd_ffa_error_return(handle,
488 						      FFA_ERROR_NOT_SUPPORTED);
489 		}
490 
491 		/* Forward SMC from Normal world to the SPM Core */
492 		if (!secure_origin) {
493 			return spmd_smc_forward(smc_fid, secure_origin,
494 						x1, x2, x3, x4, handle);
495 		}
496 
497 		/*
498 		 * Return success if call was from secure world i.e. all
499 		 * FFA functions are supported. This is essentially a
500 		 * nop.
501 		 */
502 		SMC_RET8(handle, FFA_SUCCESS_SMC32, x1, x2, x3, x4,
503 			 SMC_GET_GP(handle, CTX_GPREG_X5),
504 			 SMC_GET_GP(handle, CTX_GPREG_X6),
505 			 SMC_GET_GP(handle, CTX_GPREG_X7));
506 
507 		break; /* not reached */
508 
509 	case FFA_ID_GET:
510 		/*
511 		 * Returns the ID of the calling FFA component.
512 		 */
513 		if (!secure_origin) {
514 			SMC_RET8(handle, FFA_SUCCESS_SMC32,
515 				 FFA_TARGET_INFO_MBZ, FFA_NS_ENDPOINT_ID,
516 				 FFA_PARAM_MBZ, FFA_PARAM_MBZ,
517 				 FFA_PARAM_MBZ, FFA_PARAM_MBZ,
518 				 FFA_PARAM_MBZ);
519 		}
520 
521 		SMC_RET8(handle, FFA_SUCCESS_SMC32,
522 			 FFA_TARGET_INFO_MBZ, spmc_attrs.spmc_id,
523 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ,
524 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ,
525 			 FFA_PARAM_MBZ);
526 
527 		break; /* not reached */
528 
529 	case FFA_MSG_SEND_DIRECT_REQ_SMC32:
530 		if (secure_origin && spmd_is_spmc_message(x1)) {
531 			ret = spmd_handle_spmc_message(x3, x4,
532 				SMC_GET_GP(handle, CTX_GPREG_X5),
533 				SMC_GET_GP(handle, CTX_GPREG_X6),
534 				SMC_GET_GP(handle, CTX_GPREG_X7));
535 
536 			SMC_RET8(handle, FFA_SUCCESS_SMC32,
537 				FFA_TARGET_INFO_MBZ, ret,
538 				FFA_PARAM_MBZ, FFA_PARAM_MBZ,
539 				FFA_PARAM_MBZ, FFA_PARAM_MBZ,
540 				FFA_PARAM_MBZ);
541 		} else {
542 			/* Forward direct message to the other world */
543 			return spmd_smc_forward(smc_fid, secure_origin,
544 				x1, x2, x3, x4, handle);
545 		}
546 		break; /* Not reached */
547 
548 	case FFA_MSG_SEND_DIRECT_RESP_SMC32:
549 		if (secure_origin && spmd_is_spmc_message(x1)) {
550 			spmd_spm_core_sync_exit(0);
551 		} else {
552 			/* Forward direct message to the other world */
553 			return spmd_smc_forward(smc_fid, secure_origin,
554 				x1, x2, x3, x4, handle);
555 		}
556 		break; /* Not reached */
557 
558 	case FFA_RX_RELEASE:
559 	case FFA_RXTX_MAP_SMC32:
560 	case FFA_RXTX_MAP_SMC64:
561 	case FFA_RXTX_UNMAP:
562 	case FFA_PARTITION_INFO_GET:
563 		/*
564 		 * Should not be allowed to forward FFA_PARTITION_INFO_GET
565 		 * from Secure world to Normal world
566 		 *
567 		 * Fall through to forward the call to the other world
568 		 */
569 	case FFA_MSG_RUN:
570 		/* This interface must be invoked only by the Normal world */
571 
572 		if (secure_origin) {
573 			return spmd_ffa_error_return(handle,
574 						     FFA_ERROR_NOT_SUPPORTED);
575 		}
576 
577 		/* Fall through to forward the call to the other world */
578 	case FFA_MSG_SEND:
579 	case FFA_MSG_SEND_DIRECT_REQ_SMC64:
580 	case FFA_MSG_SEND_DIRECT_RESP_SMC64:
581 	case FFA_MEM_DONATE_SMC32:
582 	case FFA_MEM_DONATE_SMC64:
583 	case FFA_MEM_LEND_SMC32:
584 	case FFA_MEM_LEND_SMC64:
585 	case FFA_MEM_SHARE_SMC32:
586 	case FFA_MEM_SHARE_SMC64:
587 	case FFA_MEM_RETRIEVE_REQ_SMC32:
588 	case FFA_MEM_RETRIEVE_REQ_SMC64:
589 	case FFA_MEM_RETRIEVE_RESP:
590 	case FFA_MEM_RELINQUISH:
591 	case FFA_MEM_RECLAIM:
592 	case FFA_SUCCESS_SMC32:
593 	case FFA_SUCCESS_SMC64:
594 		/*
595 		 * TODO: Assume that no requests originate from EL3 at the
596 		 * moment. This will change if a SP service is required in
597 		 * response to secure interrupts targeted to EL3. Until then
598 		 * simply forward the call to the Normal world.
599 		 */
600 
601 		return spmd_smc_forward(smc_fid, secure_origin,
602 					x1, x2, x3, x4, handle);
603 		break; /* not reached */
604 
605 	case FFA_MSG_WAIT:
606 		/*
607 		 * Check if this is the first invocation of this interface on
608 		 * this CPU from the Secure world. If so, then indicate that the
609 		 * SPM Core initialised successfully.
610 		 */
611 		if (secure_origin && (ctx->state == SPMC_STATE_ON_PENDING)) {
612 			spmd_spm_core_sync_exit(0);
613 		}
614 
615 		/* Fall through to forward the call to the other world */
616 
617 	case FFA_MSG_YIELD:
618 		/* This interface must be invoked only by the Secure world */
619 		if (!secure_origin) {
620 			return spmd_ffa_error_return(handle,
621 						      FFA_ERROR_NOT_SUPPORTED);
622 		}
623 
624 		return spmd_smc_forward(smc_fid, secure_origin,
625 					x1, x2, x3, x4, handle);
626 		break; /* not reached */
627 
628 	default:
629 		WARN("SPM: Unsupported call 0x%08x\n", smc_fid);
630 		return spmd_ffa_error_return(handle, FFA_ERROR_NOT_SUPPORTED);
631 	}
632 }
633