1 /*
2  * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <string.h>
9 
10 #include <arch.h>
11 #include <arch_helpers.h>
12 #include <common/debug.h>
13 #include <lib/pmf/pmf.h>
14 #include <lib/runtime_instr.h>
15 #include <lib/smccc.h>
16 #include <plat/common/platform.h>
17 #include <services/arm_arch_svc.h>
18 
19 #include "psci_private.h"
20 
21 /*******************************************************************************
22  * PSCI frontend api for servicing SMCs. Described in the PSCI spec.
23  ******************************************************************************/
psci_cpu_on(u_register_t target_cpu,uintptr_t entrypoint,u_register_t context_id)24 int psci_cpu_on(u_register_t target_cpu,
25 		uintptr_t entrypoint,
26 		u_register_t context_id)
27 
28 {
29 	int rc;
30 	entry_point_info_t ep;
31 
32 	/* Validate the target CPU */
33 	if (!is_valid_mpidr(target_cpu))
34 		return PSCI_E_INVALID_PARAMS;
35 
36 	/* Validate the entry point and get the entry_point_info */
37 	rc = psci_validate_entry_point(&ep, entrypoint, context_id);
38 	if (rc != PSCI_E_SUCCESS)
39 		return rc;
40 
41 	/*
42 	 * To turn this cpu on, specify which power
43 	 * levels need to be turned on
44 	 */
45 	return psci_cpu_on_start(target_cpu, &ep);
46 }
47 
psci_version(void)48 unsigned int psci_version(void)
49 {
50 	return PSCI_MAJOR_VER | PSCI_MINOR_VER;
51 }
52 
psci_cpu_suspend(unsigned int power_state,uintptr_t entrypoint,u_register_t context_id)53 int psci_cpu_suspend(unsigned int power_state,
54 		     uintptr_t entrypoint,
55 		     u_register_t context_id)
56 {
57 	int rc;
58 	unsigned int target_pwrlvl, is_power_down_state;
59 	entry_point_info_t ep;
60 	psci_power_state_t state_info = { {PSCI_LOCAL_STATE_RUN} };
61 	plat_local_state_t cpu_pd_state;
62 #if PSCI_OS_INIT_MODE
63 	unsigned int cpu_idx = plat_my_core_pos();
64 	plat_local_state_t prev[PLAT_MAX_PWR_LVL];
65 #endif
66 
67 	/* Validate the power_state parameter */
68 	rc = psci_validate_power_state(power_state, &state_info);
69 	if (rc != PSCI_E_SUCCESS) {
70 		assert(rc == PSCI_E_INVALID_PARAMS);
71 		return rc;
72 	}
73 
74 	/*
75 	 * Get the value of the state type bit from the power state parameter.
76 	 */
77 	is_power_down_state = psci_get_pstate_type(power_state);
78 
79 	/* Sanity check the requested suspend levels */
80 	assert(psci_validate_suspend_req(&state_info, is_power_down_state)
81 			== PSCI_E_SUCCESS);
82 
83 	target_pwrlvl = psci_find_target_suspend_lvl(&state_info);
84 	if (target_pwrlvl == PSCI_INVALID_PWR_LVL) {
85 		ERROR("Invalid target power level for suspend operation\n");
86 		panic();
87 	}
88 
89 	/* Fast path for CPU standby.*/
90 	if (is_cpu_standby_req(is_power_down_state, target_pwrlvl)) {
91 		if  (psci_plat_pm_ops->cpu_standby == NULL)
92 			return PSCI_E_INVALID_PARAMS;
93 
94 		/*
95 		 * Set the state of the CPU power domain to the platform
96 		 * specific retention state and enter the standby state.
97 		 */
98 		cpu_pd_state = state_info.pwr_domain_state[PSCI_CPU_PWR_LVL];
99 		psci_set_cpu_local_state(cpu_pd_state);
100 
101 #if PSCI_OS_INIT_MODE
102 		/*
103 		 * If in OS-initiated mode, save a copy of the previous
104 		 * requested local power states and update the new requested
105 		 * local power states for this CPU.
106 		 */
107 		if (psci_suspend_mode == OS_INIT) {
108 			psci_update_req_local_pwr_states(target_pwrlvl, cpu_idx,
109 							 &state_info, prev);
110 		}
111 #endif
112 
113 #if ENABLE_PSCI_STAT
114 		plat_psci_stat_accounting_start(&state_info);
115 #endif
116 
117 #if ENABLE_RUNTIME_INSTRUMENTATION
118 		PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
119 		    RT_INSTR_ENTER_HW_LOW_PWR,
120 		    PMF_NO_CACHE_MAINT);
121 #endif
122 
123 		psci_plat_pm_ops->cpu_standby(cpu_pd_state);
124 
125 		/* Upon exit from standby, set the state back to RUN. */
126 		psci_set_cpu_local_state(PSCI_LOCAL_STATE_RUN);
127 
128 #if PSCI_OS_INIT_MODE
129 		/*
130 		 * If in OS-initiated mode, restore the previous requested
131 		 * local power states for this CPU.
132 		 */
133 		if (psci_suspend_mode == OS_INIT) {
134 			psci_restore_req_local_pwr_states(cpu_idx, prev);
135 		}
136 #endif
137 
138 #if ENABLE_RUNTIME_INSTRUMENTATION
139 		PMF_CAPTURE_TIMESTAMP(rt_instr_svc,
140 		    RT_INSTR_EXIT_HW_LOW_PWR,
141 		    PMF_NO_CACHE_MAINT);
142 #endif
143 
144 #if ENABLE_PSCI_STAT
145 		plat_psci_stat_accounting_stop(&state_info);
146 
147 		/* Update PSCI stats */
148 		psci_stats_update_pwr_up(PSCI_CPU_PWR_LVL, &state_info);
149 #endif
150 
151 		return PSCI_E_SUCCESS;
152 	}
153 
154 	/*
155 	 * If a power down state has been requested, we need to verify entry
156 	 * point and program entry information.
157 	 */
158 	if (is_power_down_state != 0U) {
159 		rc = psci_validate_entry_point(&ep, entrypoint, context_id);
160 		if (rc != PSCI_E_SUCCESS)
161 			return rc;
162 	}
163 
164 	/*
165 	 * Do what is needed to enter the power down state. Upon success,
166 	 * enter the final wfi which will power down this CPU. This function
167 	 * might return if the power down was abandoned for any reason, e.g.
168 	 * arrival of an interrupt
169 	 */
170 	rc = psci_cpu_suspend_start(&ep,
171 				    target_pwrlvl,
172 				    &state_info,
173 				    is_power_down_state);
174 
175 	return rc;
176 }
177 
178 
psci_system_suspend(uintptr_t entrypoint,u_register_t context_id)179 int psci_system_suspend(uintptr_t entrypoint, u_register_t context_id)
180 {
181 	int rc;
182 	psci_power_state_t state_info;
183 	entry_point_info_t ep;
184 
185 	/* Check if the current CPU is the last ON CPU in the system */
186 	if (!psci_is_last_on_cpu())
187 		return PSCI_E_DENIED;
188 
189 	/* Validate the entry point and get the entry_point_info */
190 	rc = psci_validate_entry_point(&ep, entrypoint, context_id);
191 	if (rc != PSCI_E_SUCCESS)
192 		return rc;
193 
194 	/* Query the psci_power_state for system suspend */
195 	psci_query_sys_suspend_pwrstate(&state_info);
196 
197 	/*
198 	 * Check if platform allows suspend to Highest power level
199 	 * (System level)
200 	 */
201 	if (psci_find_target_suspend_lvl(&state_info) < PLAT_MAX_PWR_LVL)
202 		return PSCI_E_DENIED;
203 
204 	/* Ensure that the psci_power_state makes sense */
205 	assert(psci_validate_suspend_req(&state_info, PSTATE_TYPE_POWERDOWN)
206 						== PSCI_E_SUCCESS);
207 	assert(is_local_state_off(
208 			state_info.pwr_domain_state[PLAT_MAX_PWR_LVL]) != 0);
209 
210 	/*
211 	 * Do what is needed to enter the system suspend state. This function
212 	 * might return if the power down was abandoned for any reason, e.g.
213 	 * arrival of an interrupt
214 	 */
215 	rc = psci_cpu_suspend_start(&ep,
216 				    PLAT_MAX_PWR_LVL,
217 				    &state_info,
218 				    PSTATE_TYPE_POWERDOWN);
219 
220 	return rc;
221 }
222 
psci_cpu_off(void)223 int psci_cpu_off(void)
224 {
225 	int rc;
226 	unsigned int target_pwrlvl = PLAT_MAX_PWR_LVL;
227 
228 	/*
229 	 * Do what is needed to power off this CPU and possible higher power
230 	 * levels if it able to do so. Upon success, enter the final wfi
231 	 * which will power down this CPU.
232 	 */
233 	rc = psci_do_cpu_off(target_pwrlvl);
234 
235 	/*
236 	 * The only error cpu_off can return is E_DENIED. So check if that's
237 	 * indeed the case.
238 	 */
239 	assert(rc == PSCI_E_DENIED);
240 
241 	return rc;
242 }
243 
psci_affinity_info(u_register_t target_affinity,unsigned int lowest_affinity_level)244 int psci_affinity_info(u_register_t target_affinity,
245 		       unsigned int lowest_affinity_level)
246 {
247 	unsigned int target_idx;
248 
249 	/* Validate the target affinity */
250 	if (!is_valid_mpidr(target_affinity))
251 		return PSCI_E_INVALID_PARAMS;
252 
253 	/* We dont support level higher than PSCI_CPU_PWR_LVL */
254 	if (lowest_affinity_level > PSCI_CPU_PWR_LVL)
255 		return PSCI_E_INVALID_PARAMS;
256 
257 	/* Calculate the cpu index of the target */
258 	target_idx = (unsigned int) plat_core_pos_by_mpidr(target_affinity);
259 
260 	/*
261 	 * Generic management:
262 	 * Perform cache maintanence ahead of reading the target CPU state to
263 	 * ensure that the data is not stale.
264 	 * There is a theoretical edge case where the cache may contain stale
265 	 * data for the target CPU data - this can occur under the following
266 	 * conditions:
267 	 * - the target CPU is in another cluster from the current
268 	 * - the target CPU was the last CPU to shutdown on its cluster
269 	 * - the cluster was removed from coherency as part of the CPU shutdown
270 	 *
271 	 * In this case the cache maintenace that was performed as part of the
272 	 * target CPUs shutdown was not seen by the current CPU's cluster. And
273 	 * so the cache may contain stale data for the target CPU.
274 	 */
275 	flush_cpu_data_by_index(target_idx,
276 				psci_svc_cpu_data.aff_info_state);
277 
278 	return psci_get_aff_info_state_by_idx(target_idx);
279 }
280 
psci_migrate(u_register_t target_cpu)281 int psci_migrate(u_register_t target_cpu)
282 {
283 	int rc;
284 	u_register_t resident_cpu_mpidr;
285 
286 	/* Validate the target cpu */
287 	if (!is_valid_mpidr(target_cpu))
288 		return PSCI_E_INVALID_PARAMS;
289 
290 	rc = psci_spd_migrate_info(&resident_cpu_mpidr);
291 	if (rc != PSCI_TOS_UP_MIG_CAP)
292 		return (rc == PSCI_TOS_NOT_UP_MIG_CAP) ?
293 			  PSCI_E_DENIED : PSCI_E_NOT_SUPPORTED;
294 
295 	/*
296 	 * Migrate should only be invoked on the CPU where
297 	 * the Secure OS is resident.
298 	 */
299 	if (resident_cpu_mpidr != read_mpidr_el1())
300 		return PSCI_E_NOT_PRESENT;
301 
302 	/* Check the validity of the specified target cpu */
303 	if (!is_valid_mpidr(target_cpu))
304 		return PSCI_E_INVALID_PARAMS;
305 
306 	assert((psci_spd_pm != NULL) && (psci_spd_pm->svc_migrate != NULL));
307 
308 	rc = psci_spd_pm->svc_migrate(read_mpidr_el1(), target_cpu);
309 	assert((rc == PSCI_E_SUCCESS) || (rc == PSCI_E_INTERN_FAIL));
310 
311 	return rc;
312 }
313 
psci_migrate_info_type(void)314 int psci_migrate_info_type(void)
315 {
316 	u_register_t resident_cpu_mpidr;
317 
318 	return psci_spd_migrate_info(&resident_cpu_mpidr);
319 }
320 
psci_migrate_info_up_cpu(void)321 u_register_t psci_migrate_info_up_cpu(void)
322 {
323 	u_register_t resident_cpu_mpidr;
324 	int rc;
325 
326 	/*
327 	 * Return value of this depends upon what
328 	 * psci_spd_migrate_info() returns.
329 	 */
330 	rc = psci_spd_migrate_info(&resident_cpu_mpidr);
331 	if ((rc != PSCI_TOS_NOT_UP_MIG_CAP) && (rc != PSCI_TOS_UP_MIG_CAP))
332 		return (u_register_t)(register_t) PSCI_E_INVALID_PARAMS;
333 
334 	return resident_cpu_mpidr;
335 }
336 
psci_node_hw_state(u_register_t target_cpu,unsigned int power_level)337 int psci_node_hw_state(u_register_t target_cpu,
338 		       unsigned int power_level)
339 {
340 	int rc;
341 
342 	/* Validate target_cpu */
343 	if (!is_valid_mpidr(target_cpu))
344 		return PSCI_E_INVALID_PARAMS;
345 
346 	/* Validate power_level against PLAT_MAX_PWR_LVL */
347 	if (power_level > PLAT_MAX_PWR_LVL)
348 		return PSCI_E_INVALID_PARAMS;
349 
350 	/*
351 	 * Dispatch this call to platform to query power controller, and pass on
352 	 * to the caller what it returns
353 	 */
354 	assert(psci_plat_pm_ops->get_node_hw_state != NULL);
355 	rc = psci_plat_pm_ops->get_node_hw_state(target_cpu, power_level);
356 	assert(((rc >= HW_ON) && (rc <= HW_STANDBY))
357 		|| (rc == PSCI_E_NOT_SUPPORTED)
358 		|| (rc == PSCI_E_INVALID_PARAMS));
359 	return rc;
360 }
361 
psci_features(unsigned int psci_fid)362 int psci_features(unsigned int psci_fid)
363 {
364 	unsigned int local_caps = psci_caps;
365 
366 	if (psci_fid == SMCCC_VERSION)
367 		return PSCI_E_SUCCESS;
368 
369 	/* Check if it is a 64 bit function */
370 	if (((psci_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_64)
371 		local_caps &= PSCI_CAP_64BIT_MASK;
372 
373 	/* Check for invalid fid */
374 	if (!(is_std_svc_call(psci_fid) && is_valid_fast_smc(psci_fid)
375 			&& is_psci_fid(psci_fid)))
376 		return PSCI_E_NOT_SUPPORTED;
377 
378 
379 	/* Check if the psci fid is supported or not */
380 	if ((local_caps & define_psci_cap(psci_fid)) == 0U)
381 		return PSCI_E_NOT_SUPPORTED;
382 
383 	/* Format the feature flags */
384 	if ((psci_fid == PSCI_CPU_SUSPEND_AARCH32) ||
385 	    (psci_fid == PSCI_CPU_SUSPEND_AARCH64)) {
386 		unsigned int ret = ((FF_PSTATE << FF_PSTATE_SHIFT) |
387 			(FF_SUPPORTS_OS_INIT_MODE << FF_MODE_SUPPORT_SHIFT));
388 		return (int)ret;
389 	}
390 
391 	/* Return 0 for all other fid's */
392 	return PSCI_E_SUCCESS;
393 }
394 
395 #if PSCI_OS_INIT_MODE
psci_set_suspend_mode(unsigned int mode)396 int psci_set_suspend_mode(unsigned int mode)
397 {
398 	if (psci_suspend_mode == mode) {
399 		return PSCI_E_SUCCESS;
400 	}
401 
402 	if (mode == PLAT_COORD) {
403 		/* Check if the current CPU is the last ON CPU in the system */
404 		if (!psci_is_last_on_cpu_safe()) {
405 			return PSCI_E_DENIED;
406 		}
407 	}
408 
409 	if (mode == OS_INIT) {
410 		/*
411 		 * Check if all CPUs in the system are ON or if the current
412 		 * CPU is the last ON CPU in the system.
413 		 */
414 		if (!(psci_are_all_cpus_on_safe() ||
415 		      psci_is_last_on_cpu_safe())) {
416 			return PSCI_E_DENIED;
417 		}
418 	}
419 
420 	psci_suspend_mode = mode;
421 	psci_flush_dcache_range((uintptr_t)&psci_suspend_mode,
422 				sizeof(psci_suspend_mode));
423 
424 	return PSCI_E_SUCCESS;
425 }
426 #endif
427 
428 /*******************************************************************************
429  * PSCI top level handler for servicing SMCs.
430  ******************************************************************************/
psci_smc_handler(uint32_t smc_fid,u_register_t x1,u_register_t x2,u_register_t x3,u_register_t x4,void * cookie,void * handle,u_register_t flags)431 u_register_t psci_smc_handler(uint32_t smc_fid,
432 			  u_register_t x1,
433 			  u_register_t x2,
434 			  u_register_t x3,
435 			  u_register_t x4,
436 			  void *cookie,
437 			  void *handle,
438 			  u_register_t flags)
439 {
440 	u_register_t ret;
441 
442 	if (is_caller_secure(flags))
443 		return (u_register_t)SMC_UNK;
444 
445 	/* Check the fid against the capabilities */
446 	if ((psci_caps & define_psci_cap(smc_fid)) == 0U)
447 		return (u_register_t)SMC_UNK;
448 
449 	if (((smc_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_32) {
450 		/* 32-bit PSCI function, clear top parameter bits */
451 
452 		uint32_t r1 = (uint32_t)x1;
453 		uint32_t r2 = (uint32_t)x2;
454 		uint32_t r3 = (uint32_t)x3;
455 
456 		switch (smc_fid) {
457 		case PSCI_VERSION:
458 			ret = (u_register_t)psci_version();
459 			break;
460 
461 		case PSCI_CPU_OFF:
462 			ret = (u_register_t)psci_cpu_off();
463 			break;
464 
465 		case PSCI_CPU_SUSPEND_AARCH32:
466 			ret = (u_register_t)psci_cpu_suspend(r1, r2, r3);
467 			break;
468 
469 		case PSCI_CPU_ON_AARCH32:
470 			ret = (u_register_t)psci_cpu_on(r1, r2, r3);
471 			break;
472 
473 		case PSCI_AFFINITY_INFO_AARCH32:
474 			ret = (u_register_t)psci_affinity_info(r1, r2);
475 			break;
476 
477 		case PSCI_MIG_AARCH32:
478 			ret = (u_register_t)psci_migrate(r1);
479 			break;
480 
481 		case PSCI_MIG_INFO_TYPE:
482 			ret = (u_register_t)psci_migrate_info_type();
483 			break;
484 
485 		case PSCI_MIG_INFO_UP_CPU_AARCH32:
486 			ret = psci_migrate_info_up_cpu();
487 			break;
488 
489 		case PSCI_NODE_HW_STATE_AARCH32:
490 			ret = (u_register_t)psci_node_hw_state(r1, r2);
491 			break;
492 
493 		case PSCI_SYSTEM_SUSPEND_AARCH32:
494 			ret = (u_register_t)psci_system_suspend(r1, r2);
495 			break;
496 
497 		case PSCI_SYSTEM_OFF:
498 			psci_system_off();
499 			/* We should never return from psci_system_off() */
500 			break;
501 
502 		case PSCI_SYSTEM_RESET:
503 			psci_system_reset();
504 			/* We should never return from psci_system_reset() */
505 			break;
506 
507 		case PSCI_FEATURES:
508 			ret = (u_register_t)psci_features(r1);
509 			break;
510 
511 #if PSCI_OS_INIT_MODE
512 		case PSCI_SET_SUSPEND_MODE:
513 			ret = (u_register_t)psci_set_suspend_mode(r1);
514 			break;
515 #endif
516 
517 #if ENABLE_PSCI_STAT
518 		case PSCI_STAT_RESIDENCY_AARCH32:
519 			ret = psci_stat_residency(r1, r2);
520 			break;
521 
522 		case PSCI_STAT_COUNT_AARCH32:
523 			ret = psci_stat_count(r1, r2);
524 			break;
525 #endif
526 		case PSCI_MEM_PROTECT:
527 			ret = psci_mem_protect(r1);
528 			break;
529 
530 		case PSCI_MEM_CHK_RANGE_AARCH32:
531 			ret = psci_mem_chk_range(r1, r2);
532 			break;
533 
534 		case PSCI_SYSTEM_RESET2_AARCH32:
535 			/* We should never return from psci_system_reset2() */
536 			ret = psci_system_reset2(r1, r2);
537 			break;
538 
539 		default:
540 			WARN("Unimplemented PSCI Call: 0x%x\n", smc_fid);
541 			ret = (u_register_t)SMC_UNK;
542 			break;
543 		}
544 	} else {
545 		/* 64-bit PSCI function */
546 
547 		switch (smc_fid) {
548 		case PSCI_CPU_SUSPEND_AARCH64:
549 			ret = (u_register_t)
550 				psci_cpu_suspend((unsigned int)x1, x2, x3);
551 			break;
552 
553 		case PSCI_CPU_ON_AARCH64:
554 			ret = (u_register_t)psci_cpu_on(x1, x2, x3);
555 			break;
556 
557 		case PSCI_AFFINITY_INFO_AARCH64:
558 			ret = (u_register_t)
559 				psci_affinity_info(x1, (unsigned int)x2);
560 			break;
561 
562 		case PSCI_MIG_AARCH64:
563 			ret = (u_register_t)psci_migrate(x1);
564 			break;
565 
566 		case PSCI_MIG_INFO_UP_CPU_AARCH64:
567 			ret = psci_migrate_info_up_cpu();
568 			break;
569 
570 		case PSCI_NODE_HW_STATE_AARCH64:
571 			ret = (u_register_t)psci_node_hw_state(
572 					x1, (unsigned int) x2);
573 			break;
574 
575 		case PSCI_SYSTEM_SUSPEND_AARCH64:
576 			ret = (u_register_t)psci_system_suspend(x1, x2);
577 			break;
578 
579 #if ENABLE_PSCI_STAT
580 		case PSCI_STAT_RESIDENCY_AARCH64:
581 			ret = psci_stat_residency(x1, (unsigned int) x2);
582 			break;
583 
584 		case PSCI_STAT_COUNT_AARCH64:
585 			ret = psci_stat_count(x1, (unsigned int) x2);
586 			break;
587 #endif
588 
589 		case PSCI_MEM_CHK_RANGE_AARCH64:
590 			ret = psci_mem_chk_range(x1, x2);
591 			break;
592 
593 		case PSCI_SYSTEM_RESET2_AARCH64:
594 			/* We should never return from psci_system_reset2() */
595 			ret = psci_system_reset2((uint32_t) x1, x2);
596 			break;
597 
598 		default:
599 			WARN("Unimplemented PSCI Call: 0x%x\n", smc_fid);
600 			ret = (u_register_t)SMC_UNK;
601 			break;
602 		}
603 	}
604 
605 	return ret;
606 }
607