xref: /rk3399_ARM-atf/lib/psci/psci_common.c (revision b0408e87f7dfbdfe3e00cd3c1421b2939dd209ca)
1 /*
2  * Copyright (c) 2013-2017, 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 #include <arch.h>
32 #include <arch_helpers.h>
33 #include <assert.h>
34 #include <bl_common.h>
35 #include <context.h>
36 #include <context_mgmt.h>
37 #include <debug.h>
38 #include <platform.h>
39 #include <string.h>
40 #include <utils.h>
41 #include "psci_private.h"
42 
43 /*
44  * SPD power management operations, expected to be supplied by the registered
45  * SPD on successful SP initialization
46  */
47 const spd_pm_ops_t *psci_spd_pm;
48 
49 /*
50  * PSCI requested local power state map. This array is used to store the local
51  * power states requested by a CPU for power levels from level 1 to
52  * PLAT_MAX_PWR_LVL. It does not store the requested local power state for power
53  * level 0 (PSCI_CPU_PWR_LVL) as the requested and the target power state for a
54  * CPU are the same.
55  *
56  * During state coordination, the platform is passed an array containing the
57  * local states requested for a particular non cpu power domain by each cpu
58  * within the domain.
59  *
60  * TODO: Dense packing of the requested states will cause cache thrashing
61  * when multiple power domains write to it. If we allocate the requested
62  * states at each power level in a cache-line aligned per-domain memory,
63  * the cache thrashing can be avoided.
64  */
65 static plat_local_state_t
66 	psci_req_local_pwr_states[PLAT_MAX_PWR_LVL][PLATFORM_CORE_COUNT];
67 
68 
69 /*******************************************************************************
70  * Arrays that hold the platform's power domain tree information for state
71  * management of power domains.
72  * Each node in the array 'psci_non_cpu_pd_nodes' corresponds to a power domain
73  * which is an ancestor of a CPU power domain.
74  * Each node in the array 'psci_cpu_pd_nodes' corresponds to a cpu power domain
75  ******************************************************************************/
76 non_cpu_pd_node_t psci_non_cpu_pd_nodes[PSCI_NUM_NON_CPU_PWR_DOMAINS]
77 #if USE_COHERENT_MEM
78 __section("tzfw_coherent_mem")
79 #endif
80 ;
81 
82 /* Lock for PSCI state coordination */
83 DEFINE_PSCI_LOCK(psci_locks[PSCI_NUM_NON_CPU_PWR_DOMAINS]);
84 
85 cpu_pd_node_t psci_cpu_pd_nodes[PLATFORM_CORE_COUNT];
86 
87 /*******************************************************************************
88  * Pointer to functions exported by the platform to complete power mgmt. ops
89  ******************************************************************************/
90 const plat_psci_ops_t *psci_plat_pm_ops;
91 
92 /******************************************************************************
93  * Check that the maximum power level supported by the platform makes sense
94  *****************************************************************************/
95 CASSERT(PLAT_MAX_PWR_LVL <= PSCI_MAX_PWR_LVL && \
96 		PLAT_MAX_PWR_LVL >= PSCI_CPU_PWR_LVL, \
97 		assert_platform_max_pwrlvl_check);
98 
99 /*
100  * The plat_local_state used by the platform is one of these types: RUN,
101  * RETENTION and OFF. The platform can define further sub-states for each type
102  * apart from RUN. This categorization is done to verify the sanity of the
103  * psci_power_state passed by the platform and to print debug information. The
104  * categorization is done on the basis of the following conditions:
105  *
106  * 1. If (plat_local_state == 0) then the category is STATE_TYPE_RUN.
107  *
108  * 2. If (0 < plat_local_state <= PLAT_MAX_RET_STATE), then the category is
109  *    STATE_TYPE_RETN.
110  *
111  * 3. If (plat_local_state > PLAT_MAX_RET_STATE), then the category is
112  *    STATE_TYPE_OFF.
113  */
114 typedef enum plat_local_state_type {
115 	STATE_TYPE_RUN = 0,
116 	STATE_TYPE_RETN,
117 	STATE_TYPE_OFF
118 } plat_local_state_type_t;
119 
120 /* The macro used to categorize plat_local_state. */
121 #define find_local_state_type(plat_local_state)					\
122 		((plat_local_state) ? ((plat_local_state > PLAT_MAX_RET_STATE)	\
123 		? STATE_TYPE_OFF : STATE_TYPE_RETN)				\
124 		: STATE_TYPE_RUN)
125 
126 /******************************************************************************
127  * Check that the maximum retention level supported by the platform is less
128  * than the maximum off level.
129  *****************************************************************************/
130 CASSERT(PLAT_MAX_RET_STATE < PLAT_MAX_OFF_STATE, \
131 		assert_platform_max_off_and_retn_state_check);
132 
133 /******************************************************************************
134  * This function ensures that the power state parameter in a CPU_SUSPEND request
135  * is valid. If so, it returns the requested states for each power level.
136  *****************************************************************************/
137 int psci_validate_power_state(unsigned int power_state,
138 			      psci_power_state_t *state_info)
139 {
140 	/* Check SBZ bits in power state are zero */
141 	if (psci_check_power_state(power_state))
142 		return PSCI_E_INVALID_PARAMS;
143 
144 	assert(psci_plat_pm_ops->validate_power_state);
145 
146 	/* Validate the power_state using platform pm_ops */
147 	return psci_plat_pm_ops->validate_power_state(power_state, state_info);
148 }
149 
150 /******************************************************************************
151  * This function retrieves the `psci_power_state_t` for system suspend from
152  * the platform.
153  *****************************************************************************/
154 void psci_query_sys_suspend_pwrstate(psci_power_state_t *state_info)
155 {
156 	/*
157 	 * Assert that the required pm_ops hook is implemented to ensure that
158 	 * the capability detected during psci_setup() is valid.
159 	 */
160 	assert(psci_plat_pm_ops->get_sys_suspend_power_state);
161 
162 	/*
163 	 * Query the platform for the power_state required for system suspend
164 	 */
165 	psci_plat_pm_ops->get_sys_suspend_power_state(state_info);
166 }
167 
168 /*******************************************************************************
169  * This function verifies that the all the other cores in the system have been
170  * turned OFF and the current CPU is the last running CPU in the system.
171  * Returns 1 (true) if the current CPU is the last ON CPU or 0 (false)
172  * otherwise.
173  ******************************************************************************/
174 unsigned int psci_is_last_on_cpu(void)
175 {
176 	unsigned int cpu_idx, my_idx = plat_my_core_pos();
177 
178 	for (cpu_idx = 0; cpu_idx < PLATFORM_CORE_COUNT; cpu_idx++) {
179 		if (cpu_idx == my_idx) {
180 			assert(psci_get_aff_info_state() == AFF_STATE_ON);
181 			continue;
182 		}
183 
184 		if (psci_get_aff_info_state_by_idx(cpu_idx) != AFF_STATE_OFF)
185 			return 0;
186 	}
187 
188 	return 1;
189 }
190 
191 /*******************************************************************************
192  * Routine to return the maximum power level to traverse to after a cpu has
193  * been physically powered up. It is expected to be called immediately after
194  * reset from assembler code.
195  ******************************************************************************/
196 static unsigned int get_power_on_target_pwrlvl(void)
197 {
198 	unsigned int pwrlvl;
199 
200 	/*
201 	 * Assume that this cpu was suspended and retrieve its target power
202 	 * level. If it is invalid then it could only have been turned off
203 	 * earlier. PLAT_MAX_PWR_LVL will be the highest power level a
204 	 * cpu can be turned off to.
205 	 */
206 	pwrlvl = psci_get_suspend_pwrlvl();
207 	if (pwrlvl == PSCI_INVALID_PWR_LVL)
208 		pwrlvl = PLAT_MAX_PWR_LVL;
209 	return pwrlvl;
210 }
211 
212 /******************************************************************************
213  * Helper function to update the requested local power state array. This array
214  * does not store the requested state for the CPU power level. Hence an
215  * assertion is added to prevent us from accessing the wrong index.
216  *****************************************************************************/
217 static void psci_set_req_local_pwr_state(unsigned int pwrlvl,
218 					 unsigned int cpu_idx,
219 					 plat_local_state_t req_pwr_state)
220 {
221 	assert(pwrlvl > PSCI_CPU_PWR_LVL);
222 	psci_req_local_pwr_states[pwrlvl - 1][cpu_idx] = req_pwr_state;
223 }
224 
225 /******************************************************************************
226  * This function initializes the psci_req_local_pwr_states.
227  *****************************************************************************/
228 void psci_init_req_local_pwr_states(void)
229 {
230 	/* Initialize the requested state of all non CPU power domains as OFF */
231 	memset(&psci_req_local_pwr_states, PLAT_MAX_OFF_STATE,
232 			sizeof(psci_req_local_pwr_states));
233 }
234 
235 /******************************************************************************
236  * Helper function to return a reference to an array containing the local power
237  * states requested by each cpu for a power domain at 'pwrlvl'. The size of the
238  * array will be the number of cpu power domains of which this power domain is
239  * an ancestor. These requested states will be used to determine a suitable
240  * target state for this power domain during psci state coordination. An
241  * assertion is added to prevent us from accessing the CPU power level.
242  *****************************************************************************/
243 static plat_local_state_t *psci_get_req_local_pwr_states(unsigned int pwrlvl,
244 							 unsigned int cpu_idx)
245 {
246 	assert(pwrlvl > PSCI_CPU_PWR_LVL);
247 
248 	return &psci_req_local_pwr_states[pwrlvl - 1][cpu_idx];
249 }
250 
251 /*
252  * psci_non_cpu_pd_nodes can be placed either in normal memory or coherent
253  * memory.
254  *
255  * With !USE_COHERENT_MEM, psci_non_cpu_pd_nodes is placed in normal memory,
256  * it's accessed by both cached and non-cached participants. To serve the common
257  * minimum, perform a cache flush before read and after write so that non-cached
258  * participants operate on latest data in main memory.
259  *
260  * When USE_COHERENT_MEM is used, psci_non_cpu_pd_nodes is placed in coherent
261  * memory. With HW_ASSISTED_COHERENCY, all PSCI participants are cache-coherent.
262  * In both cases, no cache operations are required.
263  */
264 
265 /*
266  * Retrieve local state of non-CPU power domain node from a non-cached CPU,
267  * after any required cache maintenance operation.
268  */
269 static plat_local_state_t get_non_cpu_pd_node_local_state(
270 		unsigned int parent_idx)
271 {
272 #if !USE_COHERENT_MEM || !HW_ASSISTED_COHERENCY
273 	flush_dcache_range(
274 			(uintptr_t) &psci_non_cpu_pd_nodes[parent_idx],
275 			sizeof(psci_non_cpu_pd_nodes[parent_idx]));
276 #endif
277 	return psci_non_cpu_pd_nodes[parent_idx].local_state;
278 }
279 
280 /*
281  * Update local state of non-CPU power domain node from a cached CPU; perform
282  * any required cache maintenance operation afterwards.
283  */
284 static void set_non_cpu_pd_node_local_state(unsigned int parent_idx,
285 		plat_local_state_t state)
286 {
287 	psci_non_cpu_pd_nodes[parent_idx].local_state = state;
288 #if !USE_COHERENT_MEM || !HW_ASSISTED_COHERENCY
289 	flush_dcache_range(
290 			(uintptr_t) &psci_non_cpu_pd_nodes[parent_idx],
291 			sizeof(psci_non_cpu_pd_nodes[parent_idx]));
292 #endif
293 }
294 
295 /******************************************************************************
296  * Helper function to return the current local power state of each power domain
297  * from the current cpu power domain to its ancestor at the 'end_pwrlvl'. This
298  * function will be called after a cpu is powered on to find the local state
299  * each power domain has emerged from.
300  *****************************************************************************/
301 void psci_get_target_local_pwr_states(unsigned int end_pwrlvl,
302 				      psci_power_state_t *target_state)
303 {
304 	unsigned int parent_idx, lvl;
305 	plat_local_state_t *pd_state = target_state->pwr_domain_state;
306 
307 	pd_state[PSCI_CPU_PWR_LVL] = psci_get_cpu_local_state();
308 	parent_idx = psci_cpu_pd_nodes[plat_my_core_pos()].parent_node;
309 
310 	/* Copy the local power state from node to state_info */
311 	for (lvl = PSCI_CPU_PWR_LVL + 1; lvl <= end_pwrlvl; lvl++) {
312 		pd_state[lvl] = get_non_cpu_pd_node_local_state(parent_idx);
313 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
314 	}
315 
316 	/* Set the the higher levels to RUN */
317 	for (; lvl <= PLAT_MAX_PWR_LVL; lvl++)
318 		target_state->pwr_domain_state[lvl] = PSCI_LOCAL_STATE_RUN;
319 }
320 
321 /******************************************************************************
322  * Helper function to set the target local power state that each power domain
323  * from the current cpu power domain to its ancestor at the 'end_pwrlvl' will
324  * enter. This function will be called after coordination of requested power
325  * states has been done for each power level.
326  *****************************************************************************/
327 static void psci_set_target_local_pwr_states(unsigned int end_pwrlvl,
328 					const psci_power_state_t *target_state)
329 {
330 	unsigned int parent_idx, lvl;
331 	const plat_local_state_t *pd_state = target_state->pwr_domain_state;
332 
333 	psci_set_cpu_local_state(pd_state[PSCI_CPU_PWR_LVL]);
334 
335 	/*
336 	 * Need to flush as local_state might be accessed with Data Cache
337 	 * disabled during power on
338 	 */
339 	psci_flush_cpu_data(psci_svc_cpu_data.local_state);
340 
341 	parent_idx = psci_cpu_pd_nodes[plat_my_core_pos()].parent_node;
342 
343 	/* Copy the local_state from state_info */
344 	for (lvl = 1; lvl <= end_pwrlvl; lvl++) {
345 		set_non_cpu_pd_node_local_state(parent_idx, pd_state[lvl]);
346 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
347 	}
348 }
349 
350 
351 /*******************************************************************************
352  * PSCI helper function to get the parent nodes corresponding to a cpu_index.
353  ******************************************************************************/
354 void psci_get_parent_pwr_domain_nodes(unsigned int cpu_idx,
355 				      unsigned int end_lvl,
356 				      unsigned int node_index[])
357 {
358 	unsigned int parent_node = psci_cpu_pd_nodes[cpu_idx].parent_node;
359 	int i;
360 
361 	for (i = PSCI_CPU_PWR_LVL + 1; i <= end_lvl; i++) {
362 		*node_index++ = parent_node;
363 		parent_node = psci_non_cpu_pd_nodes[parent_node].parent_node;
364 	}
365 }
366 
367 /******************************************************************************
368  * This function is invoked post CPU power up and initialization. It sets the
369  * affinity info state, target power state and requested power state for the
370  * current CPU and all its ancestor power domains to RUN.
371  *****************************************************************************/
372 void psci_set_pwr_domains_to_run(unsigned int end_pwrlvl)
373 {
374 	unsigned int parent_idx, cpu_idx = plat_my_core_pos(), lvl;
375 	parent_idx = psci_cpu_pd_nodes[cpu_idx].parent_node;
376 
377 	/* Reset the local_state to RUN for the non cpu power domains. */
378 	for (lvl = PSCI_CPU_PWR_LVL + 1; lvl <= end_pwrlvl; lvl++) {
379 		set_non_cpu_pd_node_local_state(parent_idx,
380 				PSCI_LOCAL_STATE_RUN);
381 		psci_set_req_local_pwr_state(lvl,
382 					     cpu_idx,
383 					     PSCI_LOCAL_STATE_RUN);
384 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
385 	}
386 
387 	/* Set the affinity info state to ON */
388 	psci_set_aff_info_state(AFF_STATE_ON);
389 
390 	psci_set_cpu_local_state(PSCI_LOCAL_STATE_RUN);
391 	psci_flush_cpu_data(psci_svc_cpu_data);
392 }
393 
394 /******************************************************************************
395  * This function is passed the local power states requested for each power
396  * domain (state_info) between the current CPU domain and its ancestors until
397  * the target power level (end_pwrlvl). It updates the array of requested power
398  * states with this information.
399  *
400  * Then, for each level (apart from the CPU level) until the 'end_pwrlvl', it
401  * retrieves the states requested by all the cpus of which the power domain at
402  * that level is an ancestor. It passes this information to the platform to
403  * coordinate and return the target power state. If the target state for a level
404  * is RUN then subsequent levels are not considered. At the CPU level, state
405  * coordination is not required. Hence, the requested and the target states are
406  * the same.
407  *
408  * The 'state_info' is updated with the target state for each level between the
409  * CPU and the 'end_pwrlvl' and returned to the caller.
410  *
411  * This function will only be invoked with data cache enabled and while
412  * powering down a core.
413  *****************************************************************************/
414 void psci_do_state_coordination(unsigned int end_pwrlvl,
415 				psci_power_state_t *state_info)
416 {
417 	unsigned int lvl, parent_idx, cpu_idx = plat_my_core_pos();
418 	unsigned int start_idx, ncpus;
419 	plat_local_state_t target_state, *req_states;
420 
421 	assert(end_pwrlvl <= PLAT_MAX_PWR_LVL);
422 	parent_idx = psci_cpu_pd_nodes[cpu_idx].parent_node;
423 
424 	/* For level 0, the requested state will be equivalent
425 	   to target state */
426 	for (lvl = PSCI_CPU_PWR_LVL + 1; lvl <= end_pwrlvl; lvl++) {
427 
428 		/* First update the requested power state */
429 		psci_set_req_local_pwr_state(lvl, cpu_idx,
430 					     state_info->pwr_domain_state[lvl]);
431 
432 		/* Get the requested power states for this power level */
433 		start_idx = psci_non_cpu_pd_nodes[parent_idx].cpu_start_idx;
434 		req_states = psci_get_req_local_pwr_states(lvl, start_idx);
435 
436 		/*
437 		 * Let the platform coordinate amongst the requested states at
438 		 * this power level and return the target local power state.
439 		 */
440 		ncpus = psci_non_cpu_pd_nodes[parent_idx].ncpus;
441 		target_state = plat_get_target_pwr_state(lvl,
442 							 req_states,
443 							 ncpus);
444 
445 		state_info->pwr_domain_state[lvl] = target_state;
446 
447 		/* Break early if the negotiated target power state is RUN */
448 		if (is_local_state_run(state_info->pwr_domain_state[lvl]))
449 			break;
450 
451 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
452 	}
453 
454 	/*
455 	 * This is for cases when we break out of the above loop early because
456 	 * the target power state is RUN at a power level < end_pwlvl.
457 	 * We update the requested power state from state_info and then
458 	 * set the target state as RUN.
459 	 */
460 	for (lvl = lvl + 1; lvl <= end_pwrlvl; lvl++) {
461 		psci_set_req_local_pwr_state(lvl, cpu_idx,
462 					     state_info->pwr_domain_state[lvl]);
463 		state_info->pwr_domain_state[lvl] = PSCI_LOCAL_STATE_RUN;
464 
465 	}
466 
467 	/* Update the target state in the power domain nodes */
468 	psci_set_target_local_pwr_states(end_pwrlvl, state_info);
469 }
470 
471 /******************************************************************************
472  * This function validates a suspend request by making sure that if a standby
473  * state is requested then no power level is turned off and the highest power
474  * level is placed in a standby/retention state.
475  *
476  * It also ensures that the state level X will enter is not shallower than the
477  * state level X + 1 will enter.
478  *
479  * This validation will be enabled only for DEBUG builds as the platform is
480  * expected to perform these validations as well.
481  *****************************************************************************/
482 int psci_validate_suspend_req(const psci_power_state_t *state_info,
483 			      unsigned int is_power_down_state)
484 {
485 	unsigned int max_off_lvl, target_lvl, max_retn_lvl;
486 	plat_local_state_t state;
487 	plat_local_state_type_t req_state_type, deepest_state_type;
488 	int i;
489 
490 	/* Find the target suspend power level */
491 	target_lvl = psci_find_target_suspend_lvl(state_info);
492 	if (target_lvl == PSCI_INVALID_PWR_LVL)
493 		return PSCI_E_INVALID_PARAMS;
494 
495 	/* All power domain levels are in a RUN state to begin with */
496 	deepest_state_type = STATE_TYPE_RUN;
497 
498 	for (i = target_lvl; i >= PSCI_CPU_PWR_LVL; i--) {
499 		state = state_info->pwr_domain_state[i];
500 		req_state_type = find_local_state_type(state);
501 
502 		/*
503 		 * While traversing from the highest power level to the lowest,
504 		 * the state requested for lower levels has to be the same or
505 		 * deeper i.e. equal to or greater than the state at the higher
506 		 * levels. If this condition is true, then the requested state
507 		 * becomes the deepest state encountered so far.
508 		 */
509 		if (req_state_type < deepest_state_type)
510 			return PSCI_E_INVALID_PARAMS;
511 		deepest_state_type = req_state_type;
512 	}
513 
514 	/* Find the highest off power level */
515 	max_off_lvl = psci_find_max_off_lvl(state_info);
516 
517 	/* The target_lvl is either equal to the max_off_lvl or max_retn_lvl */
518 	max_retn_lvl = PSCI_INVALID_PWR_LVL;
519 	if (target_lvl != max_off_lvl)
520 		max_retn_lvl = target_lvl;
521 
522 	/*
523 	 * If this is not a request for a power down state then max off level
524 	 * has to be invalid and max retention level has to be a valid power
525 	 * level.
526 	 */
527 	if (!is_power_down_state && (max_off_lvl != PSCI_INVALID_PWR_LVL ||
528 				    max_retn_lvl == PSCI_INVALID_PWR_LVL))
529 		return PSCI_E_INVALID_PARAMS;
530 
531 	return PSCI_E_SUCCESS;
532 }
533 
534 /******************************************************************************
535  * This function finds the highest power level which will be powered down
536  * amongst all the power levels specified in the 'state_info' structure
537  *****************************************************************************/
538 unsigned int psci_find_max_off_lvl(const psci_power_state_t *state_info)
539 {
540 	int i;
541 
542 	for (i = PLAT_MAX_PWR_LVL; i >= PSCI_CPU_PWR_LVL; i--) {
543 		if (is_local_state_off(state_info->pwr_domain_state[i]))
544 			return i;
545 	}
546 
547 	return PSCI_INVALID_PWR_LVL;
548 }
549 
550 /******************************************************************************
551  * This functions finds the level of the highest power domain which will be
552  * placed in a low power state during a suspend operation.
553  *****************************************************************************/
554 unsigned int psci_find_target_suspend_lvl(const psci_power_state_t *state_info)
555 {
556 	int i;
557 
558 	for (i = PLAT_MAX_PWR_LVL; i >= PSCI_CPU_PWR_LVL; i--) {
559 		if (!is_local_state_run(state_info->pwr_domain_state[i]))
560 			return i;
561 	}
562 
563 	return PSCI_INVALID_PWR_LVL;
564 }
565 
566 /*******************************************************************************
567  * This function is passed a cpu_index and the highest level in the topology
568  * tree that the operation should be applied to. It picks up locks in order of
569  * increasing power domain level in the range specified.
570  ******************************************************************************/
571 void psci_acquire_pwr_domain_locks(unsigned int end_pwrlvl,
572 				   unsigned int cpu_idx)
573 {
574 	unsigned int parent_idx = psci_cpu_pd_nodes[cpu_idx].parent_node;
575 	unsigned int level;
576 
577 	/* No locking required for level 0. Hence start locking from level 1 */
578 	for (level = PSCI_CPU_PWR_LVL + 1; level <= end_pwrlvl; level++) {
579 		psci_lock_get(&psci_non_cpu_pd_nodes[parent_idx]);
580 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
581 	}
582 }
583 
584 /*******************************************************************************
585  * This function is passed a cpu_index and the highest level in the topology
586  * tree that the operation should be applied to. It releases the locks in order
587  * of decreasing power domain level in the range specified.
588  ******************************************************************************/
589 void psci_release_pwr_domain_locks(unsigned int end_pwrlvl,
590 				   unsigned int cpu_idx)
591 {
592 	unsigned int parent_idx, parent_nodes[PLAT_MAX_PWR_LVL] = {0};
593 	int level;
594 
595 	/* Get the parent nodes */
596 	psci_get_parent_pwr_domain_nodes(cpu_idx, end_pwrlvl, parent_nodes);
597 
598 	/* Unlock top down. No unlocking required for level 0. */
599 	for (level = end_pwrlvl; level >= PSCI_CPU_PWR_LVL + 1; level--) {
600 		parent_idx = parent_nodes[level - 1];
601 		psci_lock_release(&psci_non_cpu_pd_nodes[parent_idx]);
602 	}
603 }
604 
605 /*******************************************************************************
606  * Simple routine to determine whether a mpidr is valid or not.
607  ******************************************************************************/
608 int psci_validate_mpidr(u_register_t mpidr)
609 {
610 	if (plat_core_pos_by_mpidr(mpidr) < 0)
611 		return PSCI_E_INVALID_PARAMS;
612 
613 	return PSCI_E_SUCCESS;
614 }
615 
616 /*******************************************************************************
617  * This function determines the full entrypoint information for the requested
618  * PSCI entrypoint on power on/resume and returns it.
619  ******************************************************************************/
620 #ifdef AARCH32
621 static int psci_get_ns_ep_info(entry_point_info_t *ep,
622 			       uintptr_t entrypoint,
623 			       u_register_t context_id)
624 {
625 	u_register_t ep_attr;
626 	unsigned int aif, ee, mode;
627 	u_register_t scr = read_scr();
628 	u_register_t ns_sctlr, sctlr;
629 
630 	/* Switch to non secure state */
631 	write_scr(scr | SCR_NS_BIT);
632 	isb();
633 	ns_sctlr = read_sctlr();
634 
635 	sctlr = scr & SCR_HCE_BIT ? read_hsctlr() : ns_sctlr;
636 
637 	/* Return to original state */
638 	write_scr(scr);
639 	isb();
640 	ee = 0;
641 
642 	ep_attr = NON_SECURE | EP_ST_DISABLE;
643 	if (sctlr & SCTLR_EE_BIT) {
644 		ep_attr |= EP_EE_BIG;
645 		ee = 1;
646 	}
647 	SET_PARAM_HEAD(ep, PARAM_EP, VERSION_1, ep_attr);
648 
649 	ep->pc = entrypoint;
650 	zeromem(&ep->args, sizeof(ep->args));
651 	ep->args.arg0 = context_id;
652 
653 	mode = scr & SCR_HCE_BIT ? MODE32_hyp : MODE32_svc;
654 
655 	/*
656 	 * TODO: Choose async. exception bits if HYP mode is not
657 	 * implemented according to the values of SCR.{AW, FW} bits
658 	 */
659 	aif = SPSR_ABT_BIT | SPSR_IRQ_BIT | SPSR_FIQ_BIT;
660 
661 	ep->spsr = SPSR_MODE32(mode, entrypoint & 0x1, ee, aif);
662 
663 	return PSCI_E_SUCCESS;
664 }
665 
666 #else
667 static int psci_get_ns_ep_info(entry_point_info_t *ep,
668 			       uintptr_t entrypoint,
669 			       u_register_t context_id)
670 {
671 	u_register_t ep_attr, sctlr;
672 	unsigned int daif, ee, mode;
673 	u_register_t ns_scr_el3 = read_scr_el3();
674 	u_register_t ns_sctlr_el1 = read_sctlr_el1();
675 
676 	sctlr = ns_scr_el3 & SCR_HCE_BIT ? read_sctlr_el2() : ns_sctlr_el1;
677 	ee = 0;
678 
679 	ep_attr = NON_SECURE | EP_ST_DISABLE;
680 	if (sctlr & SCTLR_EE_BIT) {
681 		ep_attr |= EP_EE_BIG;
682 		ee = 1;
683 	}
684 	SET_PARAM_HEAD(ep, PARAM_EP, VERSION_1, ep_attr);
685 
686 	ep->pc = entrypoint;
687 	zeromem(&ep->args, sizeof(ep->args));
688 	ep->args.arg0 = context_id;
689 
690 	/*
691 	 * Figure out whether the cpu enters the non-secure address space
692 	 * in aarch32 or aarch64
693 	 */
694 	if (ns_scr_el3 & SCR_RW_BIT) {
695 
696 		/*
697 		 * Check whether a Thumb entry point has been provided for an
698 		 * aarch64 EL
699 		 */
700 		if (entrypoint & 0x1)
701 			return PSCI_E_INVALID_ADDRESS;
702 
703 		mode = ns_scr_el3 & SCR_HCE_BIT ? MODE_EL2 : MODE_EL1;
704 
705 		ep->spsr = SPSR_64(mode, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS);
706 	} else {
707 
708 		mode = ns_scr_el3 & SCR_HCE_BIT ? MODE32_hyp : MODE32_svc;
709 
710 		/*
711 		 * TODO: Choose async. exception bits if HYP mode is not
712 		 * implemented according to the values of SCR.{AW, FW} bits
713 		 */
714 		daif = DAIF_ABT_BIT | DAIF_IRQ_BIT | DAIF_FIQ_BIT;
715 
716 		ep->spsr = SPSR_MODE32(mode, entrypoint & 0x1, ee, daif);
717 	}
718 
719 	return PSCI_E_SUCCESS;
720 }
721 #endif
722 
723 /*******************************************************************************
724  * This function validates the entrypoint with the platform layer if the
725  * appropriate pm_ops hook is exported by the platform and returns the
726  * 'entry_point_info'.
727  ******************************************************************************/
728 int psci_validate_entry_point(entry_point_info_t *ep,
729 			      uintptr_t entrypoint,
730 			      u_register_t context_id)
731 {
732 	int rc;
733 
734 	/* Validate the entrypoint using platform psci_ops */
735 	if (psci_plat_pm_ops->validate_ns_entrypoint) {
736 		rc = psci_plat_pm_ops->validate_ns_entrypoint(entrypoint);
737 		if (rc != PSCI_E_SUCCESS)
738 			return PSCI_E_INVALID_ADDRESS;
739 	}
740 
741 	/*
742 	 * Verify and derive the re-entry information for
743 	 * the non-secure world from the non-secure state from
744 	 * where this call originated.
745 	 */
746 	rc = psci_get_ns_ep_info(ep, entrypoint, context_id);
747 	return rc;
748 }
749 
750 /*******************************************************************************
751  * Generic handler which is called when a cpu is physically powered on. It
752  * traverses the node information and finds the highest power level powered
753  * off and performs generic, architectural, platform setup and state management
754  * to power on that power level and power levels below it.
755  * e.g. For a cpu that's been powered on, it will call the platform specific
756  * code to enable the gic cpu interface and for a cluster it will enable
757  * coherency at the interconnect level in addition to gic cpu interface.
758  ******************************************************************************/
759 void psci_warmboot_entrypoint(void)
760 {
761 	unsigned int end_pwrlvl, cpu_idx = plat_my_core_pos();
762 	psci_power_state_t state_info = { {PSCI_LOCAL_STATE_RUN} };
763 
764 	/*
765 	 * Verify that we have been explicitly turned ON or resumed from
766 	 * suspend.
767 	 */
768 	if (psci_get_aff_info_state() == AFF_STATE_OFF) {
769 		ERROR("Unexpected affinity info state");
770 		panic();
771 	}
772 
773 	/*
774 	 * Get the maximum power domain level to traverse to after this cpu
775 	 * has been physically powered up.
776 	 */
777 	end_pwrlvl = get_power_on_target_pwrlvl();
778 
779 	/*
780 	 * This function acquires the lock corresponding to each power level so
781 	 * that by the time all locks are taken, the system topology is snapshot
782 	 * and state management can be done safely.
783 	 */
784 	psci_acquire_pwr_domain_locks(end_pwrlvl,
785 				      cpu_idx);
786 
787 #if ENABLE_PSCI_STAT
788 	plat_psci_stat_accounting_stop(&state_info);
789 #endif
790 
791 	psci_get_target_local_pwr_states(end_pwrlvl, &state_info);
792 
793 	/*
794 	 * This CPU could be resuming from suspend or it could have just been
795 	 * turned on. To distinguish between these 2 cases, we examine the
796 	 * affinity state of the CPU:
797 	 *  - If the affinity state is ON_PENDING then it has just been
798 	 *    turned on.
799 	 *  - Else it is resuming from suspend.
800 	 *
801 	 * Depending on the type of warm reset identified, choose the right set
802 	 * of power management handler and perform the generic, architecture
803 	 * and platform specific handling.
804 	 */
805 	if (psci_get_aff_info_state() == AFF_STATE_ON_PENDING)
806 		psci_cpu_on_finish(cpu_idx, &state_info);
807 	else
808 		psci_cpu_suspend_finish(cpu_idx, &state_info);
809 
810 	/*
811 	 * Set the requested and target state of this CPU and all the higher
812 	 * power domains which are ancestors of this CPU to run.
813 	 */
814 	psci_set_pwr_domains_to_run(end_pwrlvl);
815 
816 #if ENABLE_PSCI_STAT
817 	/*
818 	 * Update PSCI stats.
819 	 * Caches are off when writing stats data on the power down path.
820 	 * Since caches are now enabled, it's necessary to do cache
821 	 * maintenance before reading that same data.
822 	 */
823 	psci_stats_update_pwr_up(end_pwrlvl, &state_info);
824 #endif
825 
826 	/*
827 	 * This loop releases the lock corresponding to each power level
828 	 * in the reverse order to which they were acquired.
829 	 */
830 	psci_release_pwr_domain_locks(end_pwrlvl,
831 				      cpu_idx);
832 }
833 
834 /*******************************************************************************
835  * This function initializes the set of hooks that PSCI invokes as part of power
836  * management operation. The power management hooks are expected to be provided
837  * by the SPD, after it finishes all its initialization
838  ******************************************************************************/
839 void psci_register_spd_pm_hook(const spd_pm_ops_t *pm)
840 {
841 	assert(pm);
842 	psci_spd_pm = pm;
843 
844 	if (pm->svc_migrate)
845 		psci_caps |= define_psci_cap(PSCI_MIG_AARCH64);
846 
847 	if (pm->svc_migrate_info)
848 		psci_caps |= define_psci_cap(PSCI_MIG_INFO_UP_CPU_AARCH64)
849 				| define_psci_cap(PSCI_MIG_INFO_TYPE);
850 }
851 
852 /*******************************************************************************
853  * This function invokes the migrate info hook in the spd_pm_ops. It performs
854  * the necessary return value validation. If the Secure Payload is UP and
855  * migrate capable, it returns the mpidr of the CPU on which the Secure payload
856  * is resident through the mpidr parameter. Else the value of the parameter on
857  * return is undefined.
858  ******************************************************************************/
859 int psci_spd_migrate_info(u_register_t *mpidr)
860 {
861 	int rc;
862 
863 	if (!psci_spd_pm || !psci_spd_pm->svc_migrate_info)
864 		return PSCI_E_NOT_SUPPORTED;
865 
866 	rc = psci_spd_pm->svc_migrate_info(mpidr);
867 
868 	assert(rc == PSCI_TOS_UP_MIG_CAP || rc == PSCI_TOS_NOT_UP_MIG_CAP \
869 		|| rc == PSCI_TOS_NOT_PRESENT_MP || rc == PSCI_E_NOT_SUPPORTED);
870 
871 	return rc;
872 }
873 
874 
875 /*******************************************************************************
876  * This function prints the state of all power domains present in the
877  * system
878  ******************************************************************************/
879 void psci_print_power_domain_map(void)
880 {
881 #if LOG_LEVEL >= LOG_LEVEL_INFO
882 	unsigned int idx;
883 	plat_local_state_t state;
884 	plat_local_state_type_t state_type;
885 
886 	/* This array maps to the PSCI_STATE_X definitions in psci.h */
887 	static const char * const psci_state_type_str[] = {
888 		"ON",
889 		"RETENTION",
890 		"OFF",
891 	};
892 
893 	INFO("PSCI Power Domain Map:\n");
894 	for (idx = 0; idx < (PSCI_NUM_PWR_DOMAINS - PLATFORM_CORE_COUNT);
895 							idx++) {
896 		state_type = find_local_state_type(
897 				psci_non_cpu_pd_nodes[idx].local_state);
898 		INFO("  Domain Node : Level %u, parent_node %d,"
899 				" State %s (0x%x)\n",
900 				psci_non_cpu_pd_nodes[idx].level,
901 				psci_non_cpu_pd_nodes[idx].parent_node,
902 				psci_state_type_str[state_type],
903 				psci_non_cpu_pd_nodes[idx].local_state);
904 	}
905 
906 	for (idx = 0; idx < PLATFORM_CORE_COUNT; idx++) {
907 		state = psci_get_cpu_local_state_by_idx(idx);
908 		state_type = find_local_state_type(state);
909 		INFO("  CPU Node : MPID 0x%llx, parent_node %d,"
910 				" State %s (0x%x)\n",
911 				(unsigned long long)psci_cpu_pd_nodes[idx].mpidr,
912 				psci_cpu_pd_nodes[idx].parent_node,
913 				psci_state_type_str[state_type],
914 				psci_get_cpu_local_state_by_idx(idx));
915 	}
916 #endif
917 }
918 
919 #if ENABLE_PLAT_COMPAT
920 /*******************************************************************************
921  * PSCI Compatibility helper function to return the 'power_state' parameter of
922  * the PSCI CPU SUSPEND request for the current CPU. Returns PSCI_INVALID_DATA
923  * if not invoked within CPU_SUSPEND for the current CPU.
924  ******************************************************************************/
925 int psci_get_suspend_powerstate(void)
926 {
927 	/* Sanity check to verify that CPU is within CPU_SUSPEND */
928 	if (psci_get_aff_info_state() == AFF_STATE_ON &&
929 		!is_local_state_run(psci_get_cpu_local_state()))
930 		return psci_power_state_compat[plat_my_core_pos()];
931 
932 	return PSCI_INVALID_DATA;
933 }
934 
935 /*******************************************************************************
936  * PSCI Compatibility helper function to return the state id of the current
937  * cpu encoded in the 'power_state' parameter. Returns PSCI_INVALID_DATA
938  * if not invoked within CPU_SUSPEND for the current CPU.
939  ******************************************************************************/
940 int psci_get_suspend_stateid(void)
941 {
942 	unsigned int power_state;
943 	power_state = psci_get_suspend_powerstate();
944 	if (power_state != PSCI_INVALID_DATA)
945 		return psci_get_pstate_id(power_state);
946 
947 	return PSCI_INVALID_DATA;
948 }
949 
950 /*******************************************************************************
951  * PSCI Compatibility helper function to return the state id encoded in the
952  * 'power_state' parameter of the CPU specified by 'mpidr'. Returns
953  * PSCI_INVALID_DATA if the CPU is not in CPU_SUSPEND.
954  ******************************************************************************/
955 int psci_get_suspend_stateid_by_mpidr(unsigned long mpidr)
956 {
957 	int cpu_idx = plat_core_pos_by_mpidr(mpidr);
958 
959 	if (cpu_idx == -1)
960 		return PSCI_INVALID_DATA;
961 
962 	/* Sanity check to verify that the CPU is in CPU_SUSPEND */
963 	if (psci_get_aff_info_state_by_idx(cpu_idx) == AFF_STATE_ON &&
964 		!is_local_state_run(psci_get_cpu_local_state_by_idx(cpu_idx)))
965 		return psci_get_pstate_id(psci_power_state_compat[cpu_idx]);
966 
967 	return PSCI_INVALID_DATA;
968 }
969 
970 /*******************************************************************************
971  * This function returns highest affinity level which is in OFF
972  * state. The affinity instance with which the level is associated is
973  * determined by the caller.
974  ******************************************************************************/
975 unsigned int psci_get_max_phys_off_afflvl(void)
976 {
977 	psci_power_state_t state_info;
978 
979 	zeromem(&state_info, sizeof(state_info));
980 	psci_get_target_local_pwr_states(PLAT_MAX_PWR_LVL, &state_info);
981 
982 	return psci_find_target_suspend_lvl(&state_info);
983 }
984 
985 /*******************************************************************************
986  * PSCI Compatibility helper function to return target affinity level requested
987  * for the CPU_SUSPEND. This function assumes affinity levels correspond to
988  * power domain levels on the platform.
989  ******************************************************************************/
990 int psci_get_suspend_afflvl(void)
991 {
992 	return psci_get_suspend_pwrlvl();
993 }
994 
995 #endif
996 
997 /*******************************************************************************
998  * Initiate power down sequence, by calling power down operations registered for
999  * this CPU.
1000  ******************************************************************************/
1001 void psci_do_pwrdown_sequence(unsigned int power_level)
1002 {
1003 #if HW_ASSISTED_COHERENCY
1004 	/*
1005 	 * With hardware-assisted coherency, the CPU drivers only initiate the
1006 	 * power down sequence, without performing cache-maintenance operations
1007 	 * in software. Data caches and MMU remain enabled both before and after
1008 	 * this call.
1009 	 */
1010 	prepare_cpu_pwr_dwn(power_level);
1011 #else
1012 	/*
1013 	 * Without hardware-assisted coherency, the CPU drivers disable data
1014 	 * caches and MMU, then perform cache-maintenance operations in
1015 	 * software.
1016 	 *
1017 	 * We ought to call prepare_cpu_pwr_dwn() to initiate power down
1018 	 * sequence. We currently have data caches and MMU enabled, but the
1019 	 * function will return with data caches and MMU disabled. We must
1020 	 * ensure that the stack memory is flushed out to memory before we start
1021 	 * popping from it again.
1022 	 */
1023 	psci_do_pwrdown_cache_maintenance(power_level);
1024 #endif
1025 }
1026