xref: /linux/drivers/firmware/psci/psci.c (revision e7d759f31ca295d589f7420719c311870bb3166f) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright (C) 2015 ARM Limited
5  */
6 
7 #define pr_fmt(fmt) "psci: " fmt
8 
9 #include <linux/acpi.h>
10 #include <linux/arm-smccc.h>
11 #include <linux/cpuidle.h>
12 #include <linux/debugfs.h>
13 #include <linux/errno.h>
14 #include <linux/linkage.h>
15 #include <linux/of.h>
16 #include <linux/pm.h>
17 #include <linux/printk.h>
18 #include <linux/psci.h>
19 #include <linux/reboot.h>
20 #include <linux/slab.h>
21 #include <linux/suspend.h>
22 
23 #include <uapi/linux/psci.h>
24 
25 #include <asm/cpuidle.h>
26 #include <asm/cputype.h>
27 #include <asm/hypervisor.h>
28 #include <asm/system_misc.h>
29 #include <asm/smp_plat.h>
30 #include <asm/suspend.h>
31 
32 /*
33  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
34  * calls it is necessary to use SMC64 to pass or return 64-bit values.
35  * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
36  * (native-width) function ID.
37  */
38 #ifdef CONFIG_64BIT
39 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN64_##name
40 #else
41 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN_##name
42 #endif
43 
44 /*
45  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
46  * calls to its resident CPU, so we must avoid issuing those. We never migrate
47  * a Trusted OS even if it claims to be capable of migration -- doing so will
48  * require cooperation with a Trusted OS driver.
49  */
50 static int resident_cpu = -1;
51 struct psci_operations psci_ops;
52 static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
53 
54 bool psci_tos_resident_on(int cpu)
55 {
56 	return cpu == resident_cpu;
57 }
58 
59 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
60 				unsigned long, unsigned long);
61 static psci_fn *invoke_psci_fn;
62 
63 static struct psci_0_1_function_ids psci_0_1_function_ids;
64 
65 struct psci_0_1_function_ids get_psci_0_1_function_ids(void)
66 {
67 	return psci_0_1_function_ids;
68 }
69 
70 #define PSCI_0_2_POWER_STATE_MASK		\
71 				(PSCI_0_2_POWER_STATE_ID_MASK | \
72 				PSCI_0_2_POWER_STATE_TYPE_MASK | \
73 				PSCI_0_2_POWER_STATE_AFFL_MASK)
74 
75 #define PSCI_1_0_EXT_POWER_STATE_MASK		\
76 				(PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
77 				PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
78 
79 static u32 psci_cpu_suspend_feature;
80 static bool psci_system_reset2_supported;
81 
82 static inline bool psci_has_ext_power_state(void)
83 {
84 	return psci_cpu_suspend_feature &
85 				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
86 }
87 
88 bool psci_has_osi_support(void)
89 {
90 	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
91 }
92 
93 static inline bool psci_power_state_loses_context(u32 state)
94 {
95 	const u32 mask = psci_has_ext_power_state() ?
96 					PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
97 					PSCI_0_2_POWER_STATE_TYPE_MASK;
98 
99 	return state & mask;
100 }
101 
102 bool psci_power_state_is_valid(u32 state)
103 {
104 	const u32 valid_mask = psci_has_ext_power_state() ?
105 			       PSCI_1_0_EXT_POWER_STATE_MASK :
106 			       PSCI_0_2_POWER_STATE_MASK;
107 
108 	return !(state & ~valid_mask);
109 }
110 
111 static __always_inline unsigned long
112 __invoke_psci_fn_hvc(unsigned long function_id,
113 		     unsigned long arg0, unsigned long arg1,
114 		     unsigned long arg2)
115 {
116 	struct arm_smccc_res res;
117 
118 	arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
119 	return res.a0;
120 }
121 
122 static __always_inline unsigned long
123 __invoke_psci_fn_smc(unsigned long function_id,
124 		     unsigned long arg0, unsigned long arg1,
125 		     unsigned long arg2)
126 {
127 	struct arm_smccc_res res;
128 
129 	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
130 	return res.a0;
131 }
132 
133 static __always_inline int psci_to_linux_errno(int errno)
134 {
135 	switch (errno) {
136 	case PSCI_RET_SUCCESS:
137 		return 0;
138 	case PSCI_RET_NOT_SUPPORTED:
139 		return -EOPNOTSUPP;
140 	case PSCI_RET_INVALID_PARAMS:
141 	case PSCI_RET_INVALID_ADDRESS:
142 		return -EINVAL;
143 	case PSCI_RET_DENIED:
144 		return -EPERM;
145 	}
146 
147 	return -EINVAL;
148 }
149 
150 static u32 psci_0_1_get_version(void)
151 {
152 	return PSCI_VERSION(0, 1);
153 }
154 
155 static u32 psci_0_2_get_version(void)
156 {
157 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
158 }
159 
160 int psci_set_osi_mode(bool enable)
161 {
162 	unsigned long suspend_mode;
163 	int err;
164 
165 	suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
166 			PSCI_1_0_SUSPEND_MODE_PC;
167 
168 	err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
169 	if (err < 0)
170 		pr_info(FW_BUG "failed to set %s mode: %d\n",
171 				enable ? "OSI" : "PC", err);
172 	return psci_to_linux_errno(err);
173 }
174 
175 static __always_inline int
176 __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
177 {
178 	int err;
179 
180 	err = invoke_psci_fn(fn, state, entry_point, 0);
181 	return psci_to_linux_errno(err);
182 }
183 
184 static __always_inline int
185 psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
186 {
187 	return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
188 				  state, entry_point);
189 }
190 
191 static __always_inline int
192 psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
193 {
194 	return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
195 				  state, entry_point);
196 }
197 
198 static int __psci_cpu_off(u32 fn, u32 state)
199 {
200 	int err;
201 
202 	err = invoke_psci_fn(fn, state, 0, 0);
203 	return psci_to_linux_errno(err);
204 }
205 
206 static int psci_0_1_cpu_off(u32 state)
207 {
208 	return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
209 }
210 
211 static int psci_0_2_cpu_off(u32 state)
212 {
213 	return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
214 }
215 
216 static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
217 {
218 	int err;
219 
220 	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
221 	return psci_to_linux_errno(err);
222 }
223 
224 static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
225 {
226 	return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
227 }
228 
229 static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
230 {
231 	return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
232 }
233 
234 static int __psci_migrate(u32 fn, unsigned long cpuid)
235 {
236 	int err;
237 
238 	err = invoke_psci_fn(fn, cpuid, 0, 0);
239 	return psci_to_linux_errno(err);
240 }
241 
242 static int psci_0_1_migrate(unsigned long cpuid)
243 {
244 	return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
245 }
246 
247 static int psci_0_2_migrate(unsigned long cpuid)
248 {
249 	return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
250 }
251 
252 static int psci_affinity_info(unsigned long target_affinity,
253 		unsigned long lowest_affinity_level)
254 {
255 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
256 			      target_affinity, lowest_affinity_level, 0);
257 }
258 
259 static int psci_migrate_info_type(void)
260 {
261 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
262 }
263 
264 static unsigned long psci_migrate_info_up_cpu(void)
265 {
266 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
267 			      0, 0, 0);
268 }
269 
270 static void set_conduit(enum arm_smccc_conduit conduit)
271 {
272 	switch (conduit) {
273 	case SMCCC_CONDUIT_HVC:
274 		invoke_psci_fn = __invoke_psci_fn_hvc;
275 		break;
276 	case SMCCC_CONDUIT_SMC:
277 		invoke_psci_fn = __invoke_psci_fn_smc;
278 		break;
279 	default:
280 		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
281 	}
282 
283 	psci_conduit = conduit;
284 }
285 
286 static int get_set_conduit_method(const struct device_node *np)
287 {
288 	const char *method;
289 
290 	pr_info("probing for conduit method from DT.\n");
291 
292 	if (of_property_read_string(np, "method", &method)) {
293 		pr_warn("missing \"method\" property\n");
294 		return -ENXIO;
295 	}
296 
297 	if (!strcmp("hvc", method)) {
298 		set_conduit(SMCCC_CONDUIT_HVC);
299 	} else if (!strcmp("smc", method)) {
300 		set_conduit(SMCCC_CONDUIT_SMC);
301 	} else {
302 		pr_warn("invalid \"method\" property: %s\n", method);
303 		return -EINVAL;
304 	}
305 	return 0;
306 }
307 
308 static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
309 			  void *data)
310 {
311 	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
312 	    psci_system_reset2_supported) {
313 		/*
314 		 * reset_type[31] = 0 (architectural)
315 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
316 		 * cookie = 0 (ignored by the implementation)
317 		 */
318 		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
319 	} else {
320 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
321 	}
322 
323 	return NOTIFY_DONE;
324 }
325 
326 static struct notifier_block psci_sys_reset_nb = {
327 	.notifier_call = psci_sys_reset,
328 	.priority = 129,
329 };
330 
331 static void psci_sys_poweroff(void)
332 {
333 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
334 }
335 
336 static int psci_features(u32 psci_func_id)
337 {
338 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
339 			      psci_func_id, 0, 0);
340 }
341 
342 #ifdef CONFIG_DEBUG_FS
343 
344 #define PSCI_ID(ver, _name) \
345 	{ .fn = PSCI_##ver##_FN_##_name, .name = #_name, }
346 #define PSCI_ID_NATIVE(ver, _name) \
347 	{ .fn = PSCI_FN_NATIVE(ver, _name), .name = #_name, }
348 
349 /* A table of all optional functions */
350 static const struct {
351 	u32 fn;
352 	const char *name;
353 } psci_fn_ids[] = {
354 	PSCI_ID_NATIVE(0_2, MIGRATE),
355 	PSCI_ID(0_2, MIGRATE_INFO_TYPE),
356 	PSCI_ID_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
357 	PSCI_ID(1_0, CPU_FREEZE),
358 	PSCI_ID_NATIVE(1_0, CPU_DEFAULT_SUSPEND),
359 	PSCI_ID_NATIVE(1_0, NODE_HW_STATE),
360 	PSCI_ID_NATIVE(1_0, SYSTEM_SUSPEND),
361 	PSCI_ID(1_0, SET_SUSPEND_MODE),
362 	PSCI_ID_NATIVE(1_0, STAT_RESIDENCY),
363 	PSCI_ID_NATIVE(1_0, STAT_COUNT),
364 	PSCI_ID_NATIVE(1_1, SYSTEM_RESET2),
365 	PSCI_ID(1_1, MEM_PROTECT),
366 	PSCI_ID_NATIVE(1_1, MEM_PROTECT_CHECK_RANGE),
367 };
368 
369 static int psci_debugfs_read(struct seq_file *s, void *data)
370 {
371 	int feature, type, i;
372 	u32 ver;
373 
374 	ver = psci_ops.get_version();
375 	seq_printf(s, "PSCIv%d.%d\n",
376 		   PSCI_VERSION_MAJOR(ver),
377 		   PSCI_VERSION_MINOR(ver));
378 
379 	/* PSCI_FEATURES is available only starting from 1.0 */
380 	if (PSCI_VERSION_MAJOR(ver) < 1)
381 		return 0;
382 
383 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
384 	if (feature != PSCI_RET_NOT_SUPPORTED) {
385 		ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
386 		seq_printf(s, "SMC Calling Convention v%d.%d\n",
387 			   PSCI_VERSION_MAJOR(ver),
388 			   PSCI_VERSION_MINOR(ver));
389 	} else {
390 		seq_puts(s, "SMC Calling Convention v1.0 is assumed\n");
391 	}
392 
393 	feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
394 	if (feature < 0) {
395 		seq_printf(s, "PSCI_FEATURES(CPU_SUSPEND) error (%d)\n", feature);
396 	} else {
397 		seq_printf(s, "OSI is %ssupported\n",
398 			   (feature & BIT(0)) ? "" : "not ");
399 		seq_printf(s, "%s StateID format is used\n",
400 			   (feature & BIT(1)) ? "Extended" : "Original");
401 	}
402 
403 	type = psci_ops.migrate_info_type();
404 	if (type == PSCI_0_2_TOS_UP_MIGRATE ||
405 	    type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
406 		unsigned long cpuid;
407 
408 		seq_printf(s, "Trusted OS %smigrate capable\n",
409 			   type == PSCI_0_2_TOS_UP_NO_MIGRATE ? "not " : "");
410 		cpuid = psci_migrate_info_up_cpu();
411 		seq_printf(s, "Trusted OS resident on physical CPU 0x%lx (#%d)\n",
412 			   cpuid, resident_cpu);
413 	} else if (type == PSCI_0_2_TOS_MP) {
414 		seq_puts(s, "Trusted OS migration not required\n");
415 	} else {
416 		if (type != PSCI_RET_NOT_SUPPORTED)
417 			seq_printf(s, "MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
418 	}
419 
420 	for (i = 0; i < ARRAY_SIZE(psci_fn_ids); i++) {
421 		feature = psci_features(psci_fn_ids[i].fn);
422 		if (feature == PSCI_RET_NOT_SUPPORTED)
423 			continue;
424 		if (feature < 0)
425 			seq_printf(s, "PSCI_FEATURES(%s) error (%d)\n",
426 				   psci_fn_ids[i].name, feature);
427 		else
428 			seq_printf(s, "%s is supported\n", psci_fn_ids[i].name);
429 	}
430 
431 	return 0;
432 }
433 
434 static int psci_debugfs_open(struct inode *inode, struct file *f)
435 {
436 	return single_open(f, psci_debugfs_read, NULL);
437 }
438 
439 static const struct file_operations psci_debugfs_ops = {
440 	.owner = THIS_MODULE,
441 	.open = psci_debugfs_open,
442 	.release = single_release,
443 	.read = seq_read,
444 	.llseek = seq_lseek
445 };
446 
447 static int __init psci_debugfs_init(void)
448 {
449 	if (!invoke_psci_fn || !psci_ops.get_version)
450 		return 0;
451 
452 	return PTR_ERR_OR_ZERO(debugfs_create_file("psci", 0444, NULL, NULL,
453 						   &psci_debugfs_ops));
454 }
455 late_initcall(psci_debugfs_init)
456 #endif
457 
458 #ifdef CONFIG_CPU_IDLE
459 static noinstr int psci_suspend_finisher(unsigned long state)
460 {
461 	u32 power_state = state;
462 	phys_addr_t pa_cpu_resume;
463 
464 	pa_cpu_resume = __pa_symbol_nodebug((unsigned long)cpu_resume);
465 
466 	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
467 }
468 
469 int psci_cpu_suspend_enter(u32 state)
470 {
471 	int ret;
472 
473 	if (!psci_power_state_loses_context(state)) {
474 		struct arm_cpuidle_irq_context context;
475 
476 		ct_cpuidle_enter();
477 		arm_cpuidle_save_irq_context(&context);
478 		ret = psci_ops.cpu_suspend(state, 0);
479 		arm_cpuidle_restore_irq_context(&context);
480 		ct_cpuidle_exit();
481 	} else {
482 		/*
483 		 * ARM64 cpu_suspend() wants to do ct_cpuidle_*() itself.
484 		 */
485 		if (!IS_ENABLED(CONFIG_ARM64))
486 			ct_cpuidle_enter();
487 
488 		ret = cpu_suspend(state, psci_suspend_finisher);
489 
490 		if (!IS_ENABLED(CONFIG_ARM64))
491 			ct_cpuidle_exit();
492 	}
493 
494 	return ret;
495 }
496 #endif
497 
498 static int psci_system_suspend(unsigned long unused)
499 {
500 	phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
501 
502 	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
503 			      pa_cpu_resume, 0, 0);
504 }
505 
506 static int psci_system_suspend_enter(suspend_state_t state)
507 {
508 	return cpu_suspend(0, psci_system_suspend);
509 }
510 
511 static const struct platform_suspend_ops psci_suspend_ops = {
512 	.valid          = suspend_valid_only_mem,
513 	.enter          = psci_system_suspend_enter,
514 };
515 
516 static void __init psci_init_system_reset2(void)
517 {
518 	int ret;
519 
520 	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
521 
522 	if (ret != PSCI_RET_NOT_SUPPORTED)
523 		psci_system_reset2_supported = true;
524 }
525 
526 static void __init psci_init_system_suspend(void)
527 {
528 	int ret;
529 
530 	if (!IS_ENABLED(CONFIG_SUSPEND))
531 		return;
532 
533 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
534 
535 	if (ret != PSCI_RET_NOT_SUPPORTED)
536 		suspend_set_ops(&psci_suspend_ops);
537 }
538 
539 static void __init psci_init_cpu_suspend(void)
540 {
541 	int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
542 
543 	if (feature != PSCI_RET_NOT_SUPPORTED)
544 		psci_cpu_suspend_feature = feature;
545 }
546 
547 /*
548  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
549  * return DENIED (which would be fatal).
550  */
551 static void __init psci_init_migrate(void)
552 {
553 	unsigned long cpuid;
554 	int type, cpu = -1;
555 
556 	type = psci_ops.migrate_info_type();
557 
558 	if (type == PSCI_0_2_TOS_MP) {
559 		pr_info("Trusted OS migration not required\n");
560 		return;
561 	}
562 
563 	if (type == PSCI_RET_NOT_SUPPORTED) {
564 		pr_info("MIGRATE_INFO_TYPE not supported.\n");
565 		return;
566 	}
567 
568 	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
569 	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
570 		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
571 		return;
572 	}
573 
574 	cpuid = psci_migrate_info_up_cpu();
575 	if (cpuid & ~MPIDR_HWID_BITMASK) {
576 		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
577 			cpuid);
578 		return;
579 	}
580 
581 	cpu = get_logical_index(cpuid);
582 	resident_cpu = cpu >= 0 ? cpu : -1;
583 
584 	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
585 }
586 
587 static void __init psci_init_smccc(void)
588 {
589 	u32 ver = ARM_SMCCC_VERSION_1_0;
590 	int feature;
591 
592 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
593 
594 	if (feature != PSCI_RET_NOT_SUPPORTED) {
595 		u32 ret;
596 		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
597 		if (ret >= ARM_SMCCC_VERSION_1_1) {
598 			arm_smccc_version_init(ret, psci_conduit);
599 			ver = ret;
600 		}
601 	}
602 
603 	/*
604 	 * Conveniently, the SMCCC and PSCI versions are encoded the
605 	 * same way. No, this isn't accidental.
606 	 */
607 	pr_info("SMC Calling Convention v%d.%d\n",
608 		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
609 
610 }
611 
612 static void __init psci_0_2_set_functions(void)
613 {
614 	pr_info("Using standard PSCI v0.2 function IDs\n");
615 
616 	psci_ops = (struct psci_operations){
617 		.get_version = psci_0_2_get_version,
618 		.cpu_suspend = psci_0_2_cpu_suspend,
619 		.cpu_off = psci_0_2_cpu_off,
620 		.cpu_on = psci_0_2_cpu_on,
621 		.migrate = psci_0_2_migrate,
622 		.affinity_info = psci_affinity_info,
623 		.migrate_info_type = psci_migrate_info_type,
624 	};
625 
626 	register_restart_handler(&psci_sys_reset_nb);
627 
628 	pm_power_off = psci_sys_poweroff;
629 }
630 
631 /*
632  * Probe function for PSCI firmware versions >= 0.2
633  */
634 static int __init psci_probe(void)
635 {
636 	u32 ver = psci_0_2_get_version();
637 
638 	pr_info("PSCIv%d.%d detected in firmware.\n",
639 			PSCI_VERSION_MAJOR(ver),
640 			PSCI_VERSION_MINOR(ver));
641 
642 	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
643 		pr_err("Conflicting PSCI version detected.\n");
644 		return -EINVAL;
645 	}
646 
647 	psci_0_2_set_functions();
648 
649 	psci_init_migrate();
650 
651 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
652 		psci_init_smccc();
653 		psci_init_cpu_suspend();
654 		psci_init_system_suspend();
655 		psci_init_system_reset2();
656 		kvm_init_hyp_services();
657 	}
658 
659 	return 0;
660 }
661 
662 typedef int (*psci_initcall_t)(const struct device_node *);
663 
664 /*
665  * PSCI init function for PSCI versions >=0.2
666  *
667  * Probe based on PSCI PSCI_VERSION function
668  */
669 static int __init psci_0_2_init(const struct device_node *np)
670 {
671 	int err;
672 
673 	err = get_set_conduit_method(np);
674 	if (err)
675 		return err;
676 
677 	/*
678 	 * Starting with v0.2, the PSCI specification introduced a call
679 	 * (PSCI_VERSION) that allows probing the firmware version, so
680 	 * that PSCI function IDs and version specific initialization
681 	 * can be carried out according to the specific version reported
682 	 * by firmware
683 	 */
684 	return psci_probe();
685 }
686 
687 /*
688  * PSCI < v0.2 get PSCI Function IDs via DT.
689  */
690 static int __init psci_0_1_init(const struct device_node *np)
691 {
692 	u32 id;
693 	int err;
694 
695 	err = get_set_conduit_method(np);
696 	if (err)
697 		return err;
698 
699 	pr_info("Using PSCI v0.1 Function IDs from DT\n");
700 
701 	psci_ops.get_version = psci_0_1_get_version;
702 
703 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
704 		psci_0_1_function_ids.cpu_suspend = id;
705 		psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
706 	}
707 
708 	if (!of_property_read_u32(np, "cpu_off", &id)) {
709 		psci_0_1_function_ids.cpu_off = id;
710 		psci_ops.cpu_off = psci_0_1_cpu_off;
711 	}
712 
713 	if (!of_property_read_u32(np, "cpu_on", &id)) {
714 		psci_0_1_function_ids.cpu_on = id;
715 		psci_ops.cpu_on = psci_0_1_cpu_on;
716 	}
717 
718 	if (!of_property_read_u32(np, "migrate", &id)) {
719 		psci_0_1_function_ids.migrate = id;
720 		psci_ops.migrate = psci_0_1_migrate;
721 	}
722 
723 	return 0;
724 }
725 
726 static int __init psci_1_0_init(const struct device_node *np)
727 {
728 	int err;
729 
730 	err = psci_0_2_init(np);
731 	if (err)
732 		return err;
733 
734 	if (psci_has_osi_support()) {
735 		pr_info("OSI mode supported.\n");
736 
737 		/* Default to PC mode. */
738 		psci_set_osi_mode(false);
739 	}
740 
741 	return 0;
742 }
743 
744 static const struct of_device_id psci_of_match[] __initconst = {
745 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
746 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
747 	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
748 	{},
749 };
750 
751 int __init psci_dt_init(void)
752 {
753 	struct device_node *np;
754 	const struct of_device_id *matched_np;
755 	psci_initcall_t init_fn;
756 	int ret;
757 
758 	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
759 
760 	if (!np || !of_device_is_available(np))
761 		return -ENODEV;
762 
763 	init_fn = (psci_initcall_t)matched_np->data;
764 	ret = init_fn(np);
765 
766 	of_node_put(np);
767 	return ret;
768 }
769 
770 #ifdef CONFIG_ACPI
771 /*
772  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
773  * explicitly clarified in SBBR
774  */
775 int __init psci_acpi_init(void)
776 {
777 	if (!acpi_psci_present()) {
778 		pr_info("is not implemented in ACPI.\n");
779 		return -EOPNOTSUPP;
780 	}
781 
782 	pr_info("probing for conduit method from ACPI.\n");
783 
784 	if (acpi_psci_use_hvc())
785 		set_conduit(SMCCC_CONDUIT_HVC);
786 	else
787 		set_conduit(SMCCC_CONDUIT_SMC);
788 
789 	return psci_probe();
790 }
791 #endif
792