xref: /rk3399_ARM-atf/services/spd/tspd/tspd_main.c (revision 532ed6183868036e4a4f83cd7a71b93266a3bdb7)
1 /*
2  * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  * Redistributions of source code must retain the above copyright notice, this
8  * list of conditions and the following disclaimer.
9  *
10  * Redistributions in binary form must reproduce the above copyright notice,
11  * this list of conditions and the following disclaimer in the documentation
12  * and/or other materials provided with the distribution.
13  *
14  * Neither the name of ARM nor the names of its contributors may be used
15  * to endorse or promote products derived from this software without specific
16  * prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 
32 /*******************************************************************************
33  * This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a
34  * plug-in component to the Secure Monitor, registered as a runtime service. The
35  * SPD is expected to be a functional extension of the Secure Payload (SP) that
36  * executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting
37  * the Trusted OS/Applications range to the dispatcher. The SPD will either
38  * handle the request locally or delegate it to the Secure Payload. It is also
39  * responsible for initialising and maintaining communication with the SP.
40  ******************************************************************************/
41 #include <arch_helpers.h>
42 #include <assert.h>
43 #include <bl_common.h>
44 #include <bl31.h>
45 #include <context_mgmt.h>
46 #include <debug.h>
47 #include <errno.h>
48 #include <platform.h>
49 #include <runtime_svc.h>
50 #include <stddef.h>
51 #include <string.h>
52 #include <tsp.h>
53 #include <uuid.h>
54 #include "tspd_private.h"
55 
56 /*******************************************************************************
57  * Address of the entrypoint vector table in the Secure Payload. It is
58  * initialised once on the primary core after a cold boot.
59  ******************************************************************************/
60 tsp_vectors_t *tsp_vectors;
61 
62 /*******************************************************************************
63  * Array to keep track of per-cpu Secure Payload state
64  ******************************************************************************/
65 tsp_context_t tspd_sp_context[TSPD_CORE_COUNT];
66 
67 
68 /* TSP UID */
69 DEFINE_SVC_UUID(tsp_uuid,
70 		0x5b3056a0, 0x3291, 0x427b, 0x98, 0x11,
71 		0x71, 0x68, 0xca, 0x50, 0xf3, 0xfa);
72 
73 int32_t tspd_init(void);
74 
75 /*
76  * This helper function handles Secure EL1 preemption. The preemption could be
77  * due Non Secure interrupts or EL3 interrupts. In both the cases we context
78  * switch to the normal world and in case of EL3 interrupts, it will again be
79  * routed to EL3 which will get handled at the exception vectors.
80  */
81 uint64_t tspd_handle_sp_preemption(void *handle)
82 {
83 	cpu_context_t *ns_cpu_context;
84 
85 	assert(handle == cm_get_context(SECURE));
86 	cm_el1_sysregs_context_save(SECURE);
87 	/* Get a reference to the non-secure context */
88 	ns_cpu_context = cm_get_context(NON_SECURE);
89 	assert(ns_cpu_context);
90 
91 	/*
92 	 * To allow Secure EL1 interrupt handler to re-enter TSP while TSP
93 	 * is preempted, the secure system register context which will get
94 	 * overwritten must be additionally saved. This is currently done
95 	 * by the TSPD S-EL1 interrupt handler.
96 	 */
97 
98 	/*
99 	 * Restore non-secure state.
100 	 */
101 	cm_el1_sysregs_context_restore(NON_SECURE);
102 	cm_set_next_eret_context(NON_SECURE);
103 
104 	/*
105 	 * The TSP was preempted during STD SMC execution.
106 	 * Return back to the normal world with SMC_PREEMPTED as error
107 	 * code in x0.
108 	 */
109 	SMC_RET1(ns_cpu_context, SMC_PREEMPTED);
110 }
111 
112 /*******************************************************************************
113  * This function is the handler registered for S-EL1 interrupts by the TSPD. It
114  * validates the interrupt and upon success arranges entry into the TSP at
115  * 'tsp_sel1_intr_entry()' for handling the interrupt.
116  ******************************************************************************/
117 static uint64_t tspd_sel1_interrupt_handler(uint32_t id,
118 					    uint32_t flags,
119 					    void *handle,
120 					    void *cookie)
121 {
122 	uint32_t linear_id;
123 	tsp_context_t *tsp_ctx;
124 
125 	/* Check the security state when the exception was generated */
126 	assert(get_interrupt_src_ss(flags) == NON_SECURE);
127 
128 	/* Sanity check the pointer to this cpu's context */
129 	assert(handle == cm_get_context(NON_SECURE));
130 
131 	/* Save the non-secure context before entering the TSP */
132 	cm_el1_sysregs_context_save(NON_SECURE);
133 
134 	/* Get a reference to this cpu's TSP context */
135 	linear_id = plat_my_core_pos();
136 	tsp_ctx = &tspd_sp_context[linear_id];
137 	assert(&tsp_ctx->cpu_ctx == cm_get_context(SECURE));
138 
139 	/*
140 	 * Determine if the TSP was previously preempted. Its last known
141 	 * context has to be preserved in this case.
142 	 * The TSP should return control to the TSPD after handling this
143 	 * S-EL1 interrupt. Preserve essential EL3 context to allow entry into
144 	 * the TSP at the S-EL1 interrupt entry point using the 'cpu_context'
145 	 * structure. There is no need to save the secure system register
146 	 * context since the TSP is supposed to preserve it during S-EL1
147 	 * interrupt handling.
148 	 */
149 	if (get_std_smc_active_flag(tsp_ctx->state)) {
150 		tsp_ctx->saved_spsr_el3 = SMC_GET_EL3(&tsp_ctx->cpu_ctx,
151 						      CTX_SPSR_EL3);
152 		tsp_ctx->saved_elr_el3 = SMC_GET_EL3(&tsp_ctx->cpu_ctx,
153 						     CTX_ELR_EL3);
154 #if TSP_NS_INTR_ASYNC_PREEMPT
155 		/*Need to save the previously interrupted secure context */
156 		memcpy(&tsp_ctx->sp_ctx, &tsp_ctx->cpu_ctx, TSPD_SP_CTX_SIZE);
157 #endif
158 	}
159 
160 	cm_el1_sysregs_context_restore(SECURE);
161 	cm_set_elr_spsr_el3(SECURE, (uint64_t) &tsp_vectors->sel1_intr_entry,
162 		    SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS));
163 
164 	cm_set_next_eret_context(SECURE);
165 
166 	/*
167 	 * Tell the TSP that it has to handle a S-EL1 interrupt synchronously.
168 	 * Also the instruction in normal world where the interrupt was
169 	 * generated is passed for debugging purposes. It is safe to retrieve
170 	 * this address from ELR_EL3 as the secure context will not take effect
171 	 * until el3_exit().
172 	 */
173 	SMC_RET2(&tsp_ctx->cpu_ctx, TSP_HANDLE_SEL1_INTR_AND_RETURN, read_elr_el3());
174 }
175 
176 #if TSP_NS_INTR_ASYNC_PREEMPT
177 /*******************************************************************************
178  * This function is the handler registered for Non secure interrupts by the
179  * TSPD. It validates the interrupt and upon success arranges entry into the
180  * normal world for handling the interrupt.
181  ******************************************************************************/
182 static uint64_t tspd_ns_interrupt_handler(uint32_t id,
183 					    uint32_t flags,
184 					    void *handle,
185 					    void *cookie)
186 {
187 	/* Check the security state when the exception was generated */
188 	assert(get_interrupt_src_ss(flags) == SECURE);
189 
190 	/*
191 	 * Disable the routing of NS interrupts from secure world to EL3 while
192 	 * interrupted on this core.
193 	 */
194 	disable_intr_rm_local(INTR_TYPE_NS, SECURE);
195 
196 	return tspd_handle_sp_preemption(handle);
197 }
198 #endif
199 
200 /*******************************************************************************
201  * Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
202  * (aarch32/aarch64) if not already known and initialises the context for entry
203  * into the SP for its initialisation.
204  ******************************************************************************/
205 int32_t tspd_setup(void)
206 {
207 	entry_point_info_t *tsp_ep_info;
208 	uint32_t linear_id;
209 
210 	linear_id = plat_my_core_pos();
211 
212 	/*
213 	 * Get information about the Secure Payload (BL32) image. Its
214 	 * absence is a critical failure.  TODO: Add support to
215 	 * conditionally include the SPD service
216 	 */
217 	tsp_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
218 	if (!tsp_ep_info) {
219 		WARN("No TSP provided by BL2 boot loader, Booting device"
220 			" without TSP initialization. SMC`s destined for TSP"
221 			" will return SMC_UNK\n");
222 		return 1;
223 	}
224 
225 	/*
226 	 * If there's no valid entry point for SP, we return a non-zero value
227 	 * signalling failure initializing the service. We bail out without
228 	 * registering any handlers
229 	 */
230 	if (!tsp_ep_info->pc)
231 		return 1;
232 
233 	/*
234 	 * We could inspect the SP image and determine its execution
235 	 * state i.e whether AArch32 or AArch64. Assuming it's AArch64
236 	 * for the time being.
237 	 */
238 	tspd_init_tsp_ep_state(tsp_ep_info,
239 				TSP_AARCH64,
240 				tsp_ep_info->pc,
241 				&tspd_sp_context[linear_id]);
242 
243 #if TSP_INIT_ASYNC
244 	bl31_set_next_image_type(SECURE);
245 #else
246 	/*
247 	 * All TSPD initialization done. Now register our init function with
248 	 * BL31 for deferred invocation
249 	 */
250 	bl31_register_bl32_init(&tspd_init);
251 #endif
252 	return 0;
253 }
254 
255 /*******************************************************************************
256  * This function passes control to the Secure Payload image (BL32) for the first
257  * time on the primary cpu after a cold boot. It assumes that a valid secure
258  * context has already been created by tspd_setup() which can be directly used.
259  * It also assumes that a valid non-secure context has been initialised by PSCI
260  * so it does not need to save and restore any non-secure state. This function
261  * performs a synchronous entry into the Secure payload. The SP passes control
262  * back to this routine through a SMC.
263  ******************************************************************************/
264 int32_t tspd_init(void)
265 {
266 	uint32_t linear_id = plat_my_core_pos();
267 	tsp_context_t *tsp_ctx = &tspd_sp_context[linear_id];
268 	entry_point_info_t *tsp_entry_point;
269 	uint64_t rc;
270 
271 	/*
272 	 * Get information about the Secure Payload (BL32) image. Its
273 	 * absence is a critical failure.
274 	 */
275 	tsp_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
276 	assert(tsp_entry_point);
277 
278 	cm_init_my_context(tsp_entry_point);
279 
280 	/*
281 	 * Arrange for an entry into the test secure payload. It will be
282 	 * returned via TSP_ENTRY_DONE case
283 	 */
284 	rc = tspd_synchronous_sp_entry(tsp_ctx);
285 	assert(rc != 0);
286 
287 	return rc;
288 }
289 
290 
291 /*******************************************************************************
292  * This function is responsible for handling all SMCs in the Trusted OS/App
293  * range from the non-secure state as defined in the SMC Calling Convention
294  * Document. It is also responsible for communicating with the Secure payload
295  * to delegate work and return results back to the non-secure state. Lastly it
296  * will also return any information that the secure payload needs to do the
297  * work assigned to it.
298  ******************************************************************************/
299 uint64_t tspd_smc_handler(uint32_t smc_fid,
300 			 uint64_t x1,
301 			 uint64_t x2,
302 			 uint64_t x3,
303 			 uint64_t x4,
304 			 void *cookie,
305 			 void *handle,
306 			 uint64_t flags)
307 {
308 	cpu_context_t *ns_cpu_context;
309 	uint32_t linear_id = plat_my_core_pos(), ns;
310 	tsp_context_t *tsp_ctx = &tspd_sp_context[linear_id];
311 	uint64_t rc;
312 #if TSP_INIT_ASYNC
313 	entry_point_info_t *next_image_info;
314 #endif
315 
316 	/* Determine which security state this SMC originated from */
317 	ns = is_caller_non_secure(flags);
318 
319 	switch (smc_fid) {
320 
321 	/*
322 	 * This function ID is used by TSP to indicate that it was
323 	 * preempted by a normal world IRQ.
324 	 *
325 	 */
326 	case TSP_PREEMPTED:
327 		if (ns)
328 			SMC_RET1(handle, SMC_UNK);
329 
330 		return tspd_handle_sp_preemption(handle);
331 
332 	/*
333 	 * This function ID is used only by the TSP to indicate that it has
334 	 * finished handling a S-EL1 interrupt or was preempted by a higher
335 	 * priority pending EL3 interrupt. Execution should resume
336 	 * in the normal world.
337 	 */
338 	case TSP_HANDLED_S_EL1_INTR:
339 		if (ns)
340 			SMC_RET1(handle, SMC_UNK);
341 
342 		assert(handle == cm_get_context(SECURE));
343 
344 		/*
345 		 * Restore the relevant EL3 state which saved to service
346 		 * this SMC.
347 		 */
348 		if (get_std_smc_active_flag(tsp_ctx->state)) {
349 			SMC_SET_EL3(&tsp_ctx->cpu_ctx,
350 				    CTX_SPSR_EL3,
351 				    tsp_ctx->saved_spsr_el3);
352 			SMC_SET_EL3(&tsp_ctx->cpu_ctx,
353 				    CTX_ELR_EL3,
354 				    tsp_ctx->saved_elr_el3);
355 #if TSP_NS_INTR_ASYNC_PREEMPT
356 			/*
357 			 * Need to restore the previously interrupted
358 			 * secure context.
359 			 */
360 			memcpy(&tsp_ctx->cpu_ctx, &tsp_ctx->sp_ctx,
361 				TSPD_SP_CTX_SIZE);
362 #endif
363 		}
364 
365 		/* Get a reference to the non-secure context */
366 		ns_cpu_context = cm_get_context(NON_SECURE);
367 		assert(ns_cpu_context);
368 
369 		/*
370 		 * Restore non-secure state. There is no need to save the
371 		 * secure system register context since the TSP was supposed
372 		 * to preserve it during S-EL1 interrupt handling.
373 		 */
374 		cm_el1_sysregs_context_restore(NON_SECURE);
375 		cm_set_next_eret_context(NON_SECURE);
376 
377 		SMC_RET0((uint64_t) ns_cpu_context);
378 
379 	/*
380 	 * This function ID is used only by the SP to indicate it has
381 	 * finished initialising itself after a cold boot
382 	 */
383 	case TSP_ENTRY_DONE:
384 		if (ns)
385 			SMC_RET1(handle, SMC_UNK);
386 
387 		/*
388 		 * Stash the SP entry points information. This is done
389 		 * only once on the primary cpu
390 		 */
391 		assert(tsp_vectors == NULL);
392 		tsp_vectors = (tsp_vectors_t *) x1;
393 
394 		if (tsp_vectors) {
395 			set_tsp_pstate(tsp_ctx->state, TSP_PSTATE_ON);
396 
397 			/*
398 			 * TSP has been successfully initialized. Register power
399 			 * managemnt hooks with PSCI
400 			 */
401 			psci_register_spd_pm_hook(&tspd_pm);
402 
403 			/*
404 			 * Register an interrupt handler for S-EL1 interrupts
405 			 * when generated during code executing in the
406 			 * non-secure state.
407 			 */
408 			flags = 0;
409 			set_interrupt_rm_flag(flags, NON_SECURE);
410 			rc = register_interrupt_type_handler(INTR_TYPE_S_EL1,
411 						tspd_sel1_interrupt_handler,
412 						flags);
413 			if (rc)
414 				panic();
415 
416 #if TSP_NS_INTR_ASYNC_PREEMPT
417 			/*
418 			 * Register an interrupt handler for NS interrupts when
419 			 * generated during code executing in secure state are
420 			 * routed to EL3.
421 			 */
422 			flags = 0;
423 			set_interrupt_rm_flag(flags, SECURE);
424 
425 			rc = register_interrupt_type_handler(INTR_TYPE_NS,
426 						tspd_ns_interrupt_handler,
427 						flags);
428 			if (rc)
429 				panic();
430 
431 			/*
432 			 * Disable the NS interrupt locally.
433 			 */
434 			disable_intr_rm_local(INTR_TYPE_NS, SECURE);
435 #endif
436 		}
437 
438 
439 #if TSP_INIT_ASYNC
440 		/* Save the Secure EL1 system register context */
441 		assert(cm_get_context(SECURE) == &tsp_ctx->cpu_ctx);
442 		cm_el1_sysregs_context_save(SECURE);
443 
444 		/* Program EL3 registers to enable entry into the next EL */
445 		next_image_info = bl31_plat_get_next_image_ep_info(NON_SECURE);
446 		assert(next_image_info);
447 		assert(NON_SECURE ==
448 				GET_SECURITY_STATE(next_image_info->h.attr));
449 
450 		cm_init_my_context(next_image_info);
451 		cm_prepare_el3_exit(NON_SECURE);
452 		SMC_RET0(cm_get_context(NON_SECURE));
453 #else
454 		/*
455 		 * SP reports completion. The SPD must have initiated
456 		 * the original request through a synchronous entry
457 		 * into the SP. Jump back to the original C runtime
458 		 * context.
459 		 */
460 		tspd_synchronous_sp_exit(tsp_ctx, x1);
461 #endif
462 
463 	/*
464 	 * These function IDs are used only by the SP to indicate it has
465 	 * finished:
466 	 * 1. turning itself on in response to an earlier psci
467 	 *    cpu_on request
468 	 * 2. resuming itself after an earlier psci cpu_suspend
469 	 *    request.
470 	 */
471 	case TSP_ON_DONE:
472 	case TSP_RESUME_DONE:
473 
474 	/*
475 	 * These function IDs are used only by the SP to indicate it has
476 	 * finished:
477 	 * 1. suspending itself after an earlier psci cpu_suspend
478 	 *    request.
479 	 * 2. turning itself off in response to an earlier psci
480 	 *    cpu_off request.
481 	 */
482 	case TSP_OFF_DONE:
483 	case TSP_SUSPEND_DONE:
484 	case TSP_SYSTEM_OFF_DONE:
485 	case TSP_SYSTEM_RESET_DONE:
486 		if (ns)
487 			SMC_RET1(handle, SMC_UNK);
488 
489 		/*
490 		 * SP reports completion. The SPD must have initiated the
491 		 * original request through a synchronous entry into the SP.
492 		 * Jump back to the original C runtime context, and pass x1 as
493 		 * return value to the caller
494 		 */
495 		tspd_synchronous_sp_exit(tsp_ctx, x1);
496 
497 		/*
498 		 * Request from non-secure client to perform an
499 		 * arithmetic operation or response from secure
500 		 * payload to an earlier request.
501 		 */
502 	case TSP_FAST_FID(TSP_ADD):
503 	case TSP_FAST_FID(TSP_SUB):
504 	case TSP_FAST_FID(TSP_MUL):
505 	case TSP_FAST_FID(TSP_DIV):
506 
507 	case TSP_STD_FID(TSP_ADD):
508 	case TSP_STD_FID(TSP_SUB):
509 	case TSP_STD_FID(TSP_MUL):
510 	case TSP_STD_FID(TSP_DIV):
511 		if (ns) {
512 			/*
513 			 * This is a fresh request from the non-secure client.
514 			 * The parameters are in x1 and x2. Figure out which
515 			 * registers need to be preserved, save the non-secure
516 			 * state and send the request to the secure payload.
517 			 */
518 			assert(handle == cm_get_context(NON_SECURE));
519 
520 			/* Check if we are already preempted */
521 			if (get_std_smc_active_flag(tsp_ctx->state))
522 				SMC_RET1(handle, SMC_UNK);
523 
524 			cm_el1_sysregs_context_save(NON_SECURE);
525 
526 			/* Save x1 and x2 for use by TSP_GET_ARGS call below */
527 			store_tsp_args(tsp_ctx, x1, x2);
528 
529 			/*
530 			 * We are done stashing the non-secure context. Ask the
531 			 * secure payload to do the work now.
532 			 */
533 
534 			/*
535 			 * Verify if there is a valid context to use, copy the
536 			 * operation type and parameters to the secure context
537 			 * and jump to the fast smc entry point in the secure
538 			 * payload. Entry into S-EL1 will take place upon exit
539 			 * from this function.
540 			 */
541 			assert(&tsp_ctx->cpu_ctx == cm_get_context(SECURE));
542 
543 			/* Set appropriate entry for SMC.
544 			 * We expect the TSP to manage the PSTATE.I and PSTATE.F
545 			 * flags as appropriate.
546 			 */
547 			if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_FAST) {
548 				cm_set_elr_el3(SECURE, (uint64_t)
549 						&tsp_vectors->fast_smc_entry);
550 			} else {
551 				set_std_smc_active_flag(tsp_ctx->state);
552 				cm_set_elr_el3(SECURE, (uint64_t)
553 						&tsp_vectors->std_smc_entry);
554 #if TSP_NS_INTR_ASYNC_PREEMPT
555 				/*
556 				 * Enable the routing of NS interrupts to EL3
557 				 * during STD SMC processing on this core.
558 				 */
559 				enable_intr_rm_local(INTR_TYPE_NS, SECURE);
560 #endif
561 			}
562 
563 			cm_el1_sysregs_context_restore(SECURE);
564 			cm_set_next_eret_context(SECURE);
565 			SMC_RET3(&tsp_ctx->cpu_ctx, smc_fid, x1, x2);
566 		} else {
567 			/*
568 			 * This is the result from the secure client of an
569 			 * earlier request. The results are in x1-x3. Copy it
570 			 * into the non-secure context, save the secure state
571 			 * and return to the non-secure state.
572 			 */
573 			assert(handle == cm_get_context(SECURE));
574 			cm_el1_sysregs_context_save(SECURE);
575 
576 			/* Get a reference to the non-secure context */
577 			ns_cpu_context = cm_get_context(NON_SECURE);
578 			assert(ns_cpu_context);
579 
580 			/* Restore non-secure state */
581 			cm_el1_sysregs_context_restore(NON_SECURE);
582 			cm_set_next_eret_context(NON_SECURE);
583 			if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_STD) {
584 				clr_std_smc_active_flag(tsp_ctx->state);
585 #if TSP_NS_INTR_ASYNC_PREEMPT
586 				/*
587 				 * Disable the routing of NS interrupts to EL3
588 				 * after STD SMC processing is finished on this
589 				 * core.
590 				 */
591 				disable_intr_rm_local(INTR_TYPE_NS, SECURE);
592 #endif
593 			}
594 
595 			SMC_RET3(ns_cpu_context, x1, x2, x3);
596 		}
597 
598 		break;
599 
600 		/*
601 		 * Request from non secure world to resume the preempted
602 		 * Standard SMC call.
603 		 */
604 	case TSP_FID_RESUME:
605 		/* RESUME should be invoked only by normal world */
606 		if (!ns) {
607 			assert(0);
608 			break;
609 		}
610 
611 		/*
612 		 * This is a resume request from the non-secure client.
613 		 * save the non-secure state and send the request to
614 		 * the secure payload.
615 		 */
616 		assert(handle == cm_get_context(NON_SECURE));
617 
618 		/* Check if we are already preempted before resume */
619 		if (!get_std_smc_active_flag(tsp_ctx->state))
620 			SMC_RET1(handle, SMC_UNK);
621 
622 		cm_el1_sysregs_context_save(NON_SECURE);
623 
624 		/*
625 		 * We are done stashing the non-secure context. Ask the
626 		 * secure payload to do the work now.
627 		 */
628 #if TSP_NS_INTR_ASYNC_PREEMPT
629 		/*
630 		 * Enable the routing of NS interrupts to EL3 during resumption
631 		 * of STD SMC call on this core.
632 		 */
633 		enable_intr_rm_local(INTR_TYPE_NS, SECURE);
634 #endif
635 
636 
637 
638 		/* We just need to return to the preempted point in
639 		 * TSP and the execution will resume as normal.
640 		 */
641 		cm_el1_sysregs_context_restore(SECURE);
642 		cm_set_next_eret_context(SECURE);
643 		SMC_RET0(&tsp_ctx->cpu_ctx);
644 
645 		/*
646 		 * This is a request from the secure payload for more arguments
647 		 * for an ongoing arithmetic operation requested by the
648 		 * non-secure world. Simply return the arguments from the non-
649 		 * secure client in the original call.
650 		 */
651 	case TSP_GET_ARGS:
652 		if (ns)
653 			SMC_RET1(handle, SMC_UNK);
654 
655 		get_tsp_args(tsp_ctx, x1, x2);
656 		SMC_RET2(handle, x1, x2);
657 
658 	case TOS_CALL_COUNT:
659 		/*
660 		 * Return the number of service function IDs implemented to
661 		 * provide service to non-secure
662 		 */
663 		SMC_RET1(handle, TSP_NUM_FID);
664 
665 	case TOS_UID:
666 		/* Return TSP UID to the caller */
667 		SMC_UUID_RET(handle, tsp_uuid);
668 
669 	case TOS_CALL_VERSION:
670 		/* Return the version of current implementation */
671 		SMC_RET2(handle, TSP_VERSION_MAJOR, TSP_VERSION_MINOR);
672 
673 	default:
674 		break;
675 	}
676 
677 	SMC_RET1(handle, SMC_UNK);
678 }
679 
680 /* Define a SPD runtime service descriptor for fast SMC calls */
681 DECLARE_RT_SVC(
682 	tspd_fast,
683 
684 	OEN_TOS_START,
685 	OEN_TOS_END,
686 	SMC_TYPE_FAST,
687 	tspd_setup,
688 	tspd_smc_handler
689 );
690 
691 /* Define a SPD runtime service descriptor for standard SMC calls */
692 DECLARE_RT_SVC(
693 	tspd_std,
694 
695 	OEN_TOS_START,
696 	OEN_TOS_END,
697 	SMC_TYPE_STD,
698 	NULL,
699 	tspd_smc_handler
700 );
701