xref: /openbmc/linux/drivers/firmware/psci/psci.c (revision d47a97bd) 
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_warn("failed to set %s mode: %d\n", enable ? "OSI" : "PC", err);
171 	return psci_to_linux_errno(err);
172 }
173 
174 static __always_inline int
175 __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
176 {
177 	int err;
178 
179 	err = invoke_psci_fn(fn, state, entry_point, 0);
180 	return psci_to_linux_errno(err);
181 }
182 
183 static __always_inline int
184 psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
185 {
186 	return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
187 				  state, entry_point);
188 }
189 
190 static __always_inline int
191 psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
192 {
193 	return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
194 				  state, entry_point);
195 }
196 
197 static int __psci_cpu_off(u32 fn, u32 state)
198 {
199 	int err;
200 
201 	err = invoke_psci_fn(fn, state, 0, 0);
202 	return psci_to_linux_errno(err);
203 }
204 
205 static int psci_0_1_cpu_off(u32 state)
206 {
207 	return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
208 }
209 
210 static int psci_0_2_cpu_off(u32 state)
211 {
212 	return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
213 }
214 
215 static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
216 {
217 	int err;
218 
219 	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
220 	return psci_to_linux_errno(err);
221 }
222 
223 static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
224 {
225 	return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
226 }
227 
228 static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
229 {
230 	return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
231 }
232 
233 static int __psci_migrate(u32 fn, unsigned long cpuid)
234 {
235 	int err;
236 
237 	err = invoke_psci_fn(fn, cpuid, 0, 0);
238 	return psci_to_linux_errno(err);
239 }
240 
241 static int psci_0_1_migrate(unsigned long cpuid)
242 {
243 	return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
244 }
245 
246 static int psci_0_2_migrate(unsigned long cpuid)
247 {
248 	return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
249 }
250 
251 static int psci_affinity_info(unsigned long target_affinity,
252 		unsigned long lowest_affinity_level)
253 {
254 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
255 			      target_affinity, lowest_affinity_level, 0);
256 }
257 
258 static int psci_migrate_info_type(void)
259 {
260 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
261 }
262 
263 static unsigned long psci_migrate_info_up_cpu(void)
264 {
265 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
266 			      0, 0, 0);
267 }
268 
269 static void set_conduit(enum arm_smccc_conduit conduit)
270 {
271 	switch (conduit) {
272 	case SMCCC_CONDUIT_HVC:
273 		invoke_psci_fn = __invoke_psci_fn_hvc;
274 		break;
275 	case SMCCC_CONDUIT_SMC:
276 		invoke_psci_fn = __invoke_psci_fn_smc;
277 		break;
278 	default:
279 		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
280 	}
281 
282 	psci_conduit = conduit;
283 }
284 
285 static int get_set_conduit_method(const struct device_node *np)
286 {
287 	const char *method;
288 
289 	pr_info("probing for conduit method from DT.\n");
290 
291 	if (of_property_read_string(np, "method", &method)) {
292 		pr_warn("missing \"method\" property\n");
293 		return -ENXIO;
294 	}
295 
296 	if (!strcmp("hvc", method)) {
297 		set_conduit(SMCCC_CONDUIT_HVC);
298 	} else if (!strcmp("smc", method)) {
299 		set_conduit(SMCCC_CONDUIT_SMC);
300 	} else {
301 		pr_warn("invalid \"method\" property: %s\n", method);
302 		return -EINVAL;
303 	}
304 	return 0;
305 }
306 
307 static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
308 			  void *data)
309 {
310 	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
311 	    psci_system_reset2_supported) {
312 		/*
313 		 * reset_type[31] = 0 (architectural)
314 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
315 		 * cookie = 0 (ignored by the implementation)
316 		 */
317 		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
318 	} else {
319 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
320 	}
321 
322 	return NOTIFY_DONE;
323 }
324 
325 static struct notifier_block psci_sys_reset_nb = {
326 	.notifier_call = psci_sys_reset,
327 	.priority = 129,
328 };
329 
330 static void psci_sys_poweroff(void)
331 {
332 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
333 }
334 
335 static int psci_features(u32 psci_func_id)
336 {
337 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
338 			      psci_func_id, 0, 0);
339 }
340 
341 #ifdef CONFIG_DEBUG_FS
342 
343 #define PSCI_ID(ver, _name) \
344 	{ .fn = PSCI_##ver##_FN_##_name, .name = #_name, }
345 #define PSCI_ID_NATIVE(ver, _name) \
346 	{ .fn = PSCI_FN_NATIVE(ver, _name), .name = #_name, }
347 
348 /* A table of all optional functions */
349 static const struct {
350 	u32 fn;
351 	const char *name;
352 } psci_fn_ids[] = {
353 	PSCI_ID_NATIVE(0_2, MIGRATE),
354 	PSCI_ID(0_2, MIGRATE_INFO_TYPE),
355 	PSCI_ID_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
356 	PSCI_ID(1_0, CPU_FREEZE),
357 	PSCI_ID_NATIVE(1_0, CPU_DEFAULT_SUSPEND),
358 	PSCI_ID_NATIVE(1_0, NODE_HW_STATE),
359 	PSCI_ID_NATIVE(1_0, SYSTEM_SUSPEND),
360 	PSCI_ID(1_0, SET_SUSPEND_MODE),
361 	PSCI_ID_NATIVE(1_0, STAT_RESIDENCY),
362 	PSCI_ID_NATIVE(1_0, STAT_COUNT),
363 	PSCI_ID_NATIVE(1_1, SYSTEM_RESET2),
364 	PSCI_ID(1_1, MEM_PROTECT),
365 	PSCI_ID_NATIVE(1_1, MEM_PROTECT_CHECK_RANGE),
366 };
367 
368 static int psci_debugfs_read(struct seq_file *s, void *data)
369 {
370 	int feature, type, i;
371 	u32 ver;
372 
373 	ver = psci_ops.get_version();
374 	seq_printf(s, "PSCIv%d.%d\n",
375 		   PSCI_VERSION_MAJOR(ver),
376 		   PSCI_VERSION_MINOR(ver));
377 
378 	/* PSCI_FEATURES is available only starting from 1.0 */
379 	if (PSCI_VERSION_MAJOR(ver) < 1)
380 		return 0;
381 
382 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
383 	if (feature != PSCI_RET_NOT_SUPPORTED) {
384 		ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
385 		seq_printf(s, "SMC Calling Convention v%d.%d\n",
386 			   PSCI_VERSION_MAJOR(ver),
387 			   PSCI_VERSION_MINOR(ver));
388 	} else {
389 		seq_puts(s, "SMC Calling Convention v1.0 is assumed\n");
390 	}
391 
392 	feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
393 	if (feature < 0) {
394 		seq_printf(s, "PSCI_FEATURES(CPU_SUSPEND) error (%d)\n", feature);
395 	} else {
396 		seq_printf(s, "OSI is %ssupported\n",
397 			   (feature & BIT(0)) ? "" : "not ");
398 		seq_printf(s, "%s StateID format is used\n",
399 			   (feature & BIT(1)) ? "Extended" : "Original");
400 	}
401 
402 	type = psci_ops.migrate_info_type();
403 	if (type == PSCI_0_2_TOS_UP_MIGRATE ||
404 	    type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
405 		unsigned long cpuid;
406 
407 		seq_printf(s, "Trusted OS %smigrate capable\n",
408 			   type == PSCI_0_2_TOS_UP_NO_MIGRATE ? "not " : "");
409 		cpuid = psci_migrate_info_up_cpu();
410 		seq_printf(s, "Trusted OS resident on physical CPU 0x%lx (#%d)\n",
411 			   cpuid, resident_cpu);
412 	} else if (type == PSCI_0_2_TOS_MP) {
413 		seq_puts(s, "Trusted OS migration not required\n");
414 	} else {
415 		if (type != PSCI_RET_NOT_SUPPORTED)
416 			seq_printf(s, "MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
417 	}
418 
419 	for (i = 0; i < ARRAY_SIZE(psci_fn_ids); i++) {
420 		feature = psci_features(psci_fn_ids[i].fn);
421 		if (feature == PSCI_RET_NOT_SUPPORTED)
422 			continue;
423 		if (feature < 0)
424 			seq_printf(s, "PSCI_FEATURES(%s) error (%d)\n",
425 				   psci_fn_ids[i].name, feature);
426 		else
427 			seq_printf(s, "%s is supported\n", psci_fn_ids[i].name);
428 	}
429 
430 	return 0;
431 }
432 
433 static int psci_debugfs_open(struct inode *inode, struct file *f)
434 {
435 	return single_open(f, psci_debugfs_read, NULL);
436 }
437 
438 static const struct file_operations psci_debugfs_ops = {
439 	.owner = THIS_MODULE,
440 	.open = psci_debugfs_open,
441 	.release = single_release,
442 	.read = seq_read,
443 	.llseek = seq_lseek
444 };
445 
446 static int __init psci_debugfs_init(void)
447 {
448 	if (!invoke_psci_fn || !psci_ops.get_version)
449 		return 0;
450 
451 	return PTR_ERR_OR_ZERO(debugfs_create_file("psci", 0444, NULL, NULL,
452 						   &psci_debugfs_ops));
453 }
454 late_initcall(psci_debugfs_init)
455 #endif
456 
457 #ifdef CONFIG_CPU_IDLE
458 static noinstr int psci_suspend_finisher(unsigned long state)
459 {
460 	u32 power_state = state;
461 	phys_addr_t pa_cpu_resume;
462 
463 	pa_cpu_resume = __pa_symbol_nodebug((unsigned long)cpu_resume);
464 
465 	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
466 }
467 
468 int psci_cpu_suspend_enter(u32 state)
469 {
470 	int ret;
471 
472 	if (!psci_power_state_loses_context(state)) {
473 		struct arm_cpuidle_irq_context context;
474 
475 		ct_cpuidle_enter();
476 		arm_cpuidle_save_irq_context(&context);
477 		ret = psci_ops.cpu_suspend(state, 0);
478 		arm_cpuidle_restore_irq_context(&context);
479 		ct_cpuidle_exit();
480 	} else {
481 		/*
482 		 * ARM64 cpu_suspend() wants to do ct_cpuidle_*() itself.
483 		 */
484 		if (!IS_ENABLED(CONFIG_ARM64))
485 			ct_cpuidle_enter();
486 
487 		ret = cpu_suspend(state, psci_suspend_finisher);
488 
489 		if (!IS_ENABLED(CONFIG_ARM64))
490 			ct_cpuidle_exit();
491 	}
492 
493 	return ret;
494 }
495 #endif
496 
497 static int psci_system_suspend(unsigned long unused)
498 {
499 	phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
500 
501 	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
502 			      pa_cpu_resume, 0, 0);
503 }
504 
505 static int psci_system_suspend_enter(suspend_state_t state)
506 {
507 	return cpu_suspend(0, psci_system_suspend);
508 }
509 
510 static const struct platform_suspend_ops psci_suspend_ops = {
511 	.valid          = suspend_valid_only_mem,
512 	.enter          = psci_system_suspend_enter,
513 };
514 
515 static void __init psci_init_system_reset2(void)
516 {
517 	int ret;
518 
519 	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
520 
521 	if (ret != PSCI_RET_NOT_SUPPORTED)
522 		psci_system_reset2_supported = true;
523 }
524 
525 static void __init psci_init_system_suspend(void)
526 {
527 	int ret;
528 
529 	if (!IS_ENABLED(CONFIG_SUSPEND))
530 		return;
531 
532 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
533 
534 	if (ret != PSCI_RET_NOT_SUPPORTED)
535 		suspend_set_ops(&psci_suspend_ops);
536 }
537 
538 static void __init psci_init_cpu_suspend(void)
539 {
540 	int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
541 
542 	if (feature != PSCI_RET_NOT_SUPPORTED)
543 		psci_cpu_suspend_feature = feature;
544 }
545 
546 /*
547  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
548  * return DENIED (which would be fatal).
549  */
550 static void __init psci_init_migrate(void)
551 {
552 	unsigned long cpuid;
553 	int type, cpu = -1;
554 
555 	type = psci_ops.migrate_info_type();
556 
557 	if (type == PSCI_0_2_TOS_MP) {
558 		pr_info("Trusted OS migration not required\n");
559 		return;
560 	}
561 
562 	if (type == PSCI_RET_NOT_SUPPORTED) {
563 		pr_info("MIGRATE_INFO_TYPE not supported.\n");
564 		return;
565 	}
566 
567 	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
568 	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
569 		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
570 		return;
571 	}
572 
573 	cpuid = psci_migrate_info_up_cpu();
574 	if (cpuid & ~MPIDR_HWID_BITMASK) {
575 		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
576 			cpuid);
577 		return;
578 	}
579 
580 	cpu = get_logical_index(cpuid);
581 	resident_cpu = cpu >= 0 ? cpu : -1;
582 
583 	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
584 }
585 
586 static void __init psci_init_smccc(void)
587 {
588 	u32 ver = ARM_SMCCC_VERSION_1_0;
589 	int feature;
590 
591 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
592 
593 	if (feature != PSCI_RET_NOT_SUPPORTED) {
594 		u32 ret;
595 		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
596 		if (ret >= ARM_SMCCC_VERSION_1_1) {
597 			arm_smccc_version_init(ret, psci_conduit);
598 			ver = ret;
599 		}
600 	}
601 
602 	/*
603 	 * Conveniently, the SMCCC and PSCI versions are encoded the
604 	 * same way. No, this isn't accidental.
605 	 */
606 	pr_info("SMC Calling Convention v%d.%d\n",
607 		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
608 
609 }
610 
611 static void __init psci_0_2_set_functions(void)
612 {
613 	pr_info("Using standard PSCI v0.2 function IDs\n");
614 
615 	psci_ops = (struct psci_operations){
616 		.get_version = psci_0_2_get_version,
617 		.cpu_suspend = psci_0_2_cpu_suspend,
618 		.cpu_off = psci_0_2_cpu_off,
619 		.cpu_on = psci_0_2_cpu_on,
620 		.migrate = psci_0_2_migrate,
621 		.affinity_info = psci_affinity_info,
622 		.migrate_info_type = psci_migrate_info_type,
623 	};
624 
625 	register_restart_handler(&psci_sys_reset_nb);
626 
627 	pm_power_off = psci_sys_poweroff;
628 }
629 
630 /*
631  * Probe function for PSCI firmware versions >= 0.2
632  */
633 static int __init psci_probe(void)
634 {
635 	u32 ver = psci_0_2_get_version();
636 
637 	pr_info("PSCIv%d.%d detected in firmware.\n",
638 			PSCI_VERSION_MAJOR(ver),
639 			PSCI_VERSION_MINOR(ver));
640 
641 	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
642 		pr_err("Conflicting PSCI version detected.\n");
643 		return -EINVAL;
644 	}
645 
646 	psci_0_2_set_functions();
647 
648 	psci_init_migrate();
649 
650 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
651 		psci_init_smccc();
652 		psci_init_cpu_suspend();
653 		psci_init_system_suspend();
654 		psci_init_system_reset2();
655 		kvm_init_hyp_services();
656 	}
657 
658 	return 0;
659 }
660 
661 typedef int (*psci_initcall_t)(const struct device_node *);
662 
663 /*
664  * PSCI init function for PSCI versions >=0.2
665  *
666  * Probe based on PSCI PSCI_VERSION function
667  */
668 static int __init psci_0_2_init(const struct device_node *np)
669 {
670 	int err;
671 
672 	err = get_set_conduit_method(np);
673 	if (err)
674 		return err;
675 
676 	/*
677 	 * Starting with v0.2, the PSCI specification introduced a call
678 	 * (PSCI_VERSION) that allows probing the firmware version, so
679 	 * that PSCI function IDs and version specific initialization
680 	 * can be carried out according to the specific version reported
681 	 * by firmware
682 	 */
683 	return psci_probe();
684 }
685 
686 /*
687  * PSCI < v0.2 get PSCI Function IDs via DT.
688  */
689 static int __init psci_0_1_init(const struct device_node *np)
690 {
691 	u32 id;
692 	int err;
693 
694 	err = get_set_conduit_method(np);
695 	if (err)
696 		return err;
697 
698 	pr_info("Using PSCI v0.1 Function IDs from DT\n");
699 
700 	psci_ops.get_version = psci_0_1_get_version;
701 
702 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
703 		psci_0_1_function_ids.cpu_suspend = id;
704 		psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
705 	}
706 
707 	if (!of_property_read_u32(np, "cpu_off", &id)) {
708 		psci_0_1_function_ids.cpu_off = id;
709 		psci_ops.cpu_off = psci_0_1_cpu_off;
710 	}
711 
712 	if (!of_property_read_u32(np, "cpu_on", &id)) {
713 		psci_0_1_function_ids.cpu_on = id;
714 		psci_ops.cpu_on = psci_0_1_cpu_on;
715 	}
716 
717 	if (!of_property_read_u32(np, "migrate", &id)) {
718 		psci_0_1_function_ids.migrate = id;
719 		psci_ops.migrate = psci_0_1_migrate;
720 	}
721 
722 	return 0;
723 }
724 
725 static int __init psci_1_0_init(const struct device_node *np)
726 {
727 	int err;
728 
729 	err = psci_0_2_init(np);
730 	if (err)
731 		return err;
732 
733 	if (psci_has_osi_support()) {
734 		pr_info("OSI mode supported.\n");
735 
736 		/* Default to PC mode. */
737 		psci_set_osi_mode(false);
738 	}
739 
740 	return 0;
741 }
742 
743 static const struct of_device_id psci_of_match[] __initconst = {
744 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
745 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
746 	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
747 	{},
748 };
749 
750 int __init psci_dt_init(void)
751 {
752 	struct device_node *np;
753 	const struct of_device_id *matched_np;
754 	psci_initcall_t init_fn;
755 	int ret;
756 
757 	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
758 
759 	if (!np || !of_device_is_available(np))
760 		return -ENODEV;
761 
762 	init_fn = (psci_initcall_t)matched_np->data;
763 	ret = init_fn(np);
764 
765 	of_node_put(np);
766 	return ret;
767 }
768 
769 #ifdef CONFIG_ACPI
770 /*
771  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
772  * explicitly clarified in SBBR
773  */
774 int __init psci_acpi_init(void)
775 {
776 	if (!acpi_psci_present()) {
777 		pr_info("is not implemented in ACPI.\n");
778 		return -EOPNOTSUPP;
779 	}
780 
781 	pr_info("probing for conduit method from ACPI.\n");
782 
783 	if (acpi_psci_use_hvc())
784 		set_conduit(SMCCC_CONDUIT_HVC);
785 	else
786 		set_conduit(SMCCC_CONDUIT_SMC);
787 
788 	return psci_probe();
789 }
790 #endif
791