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  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 */
 50static int resident_cpu = -1;
 51struct psci_operations psci_ops;
 52static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
 53
 54bool psci_tos_resident_on(int cpu)
 55{
 56	return cpu == resident_cpu;
 57}
 58
 59typedef unsigned long (psci_fn)(unsigned long, unsigned long,
 60				unsigned long, unsigned long);
 61static psci_fn *invoke_psci_fn;
 62
 63static struct psci_0_1_function_ids psci_0_1_function_ids;
 64
 65struct 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
 79static u32 psci_cpu_suspend_feature;
 80static bool psci_system_reset2_supported;
 81static bool psci_system_off2_hibernate_supported;
 82
 83static inline bool psci_has_ext_power_state(void)
 84{
 85	return psci_cpu_suspend_feature &
 86				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
 87}
 88
 89bool psci_has_osi_support(void)
 90{
 91	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
 92}
 93
 94static inline bool psci_power_state_loses_context(u32 state)
 95{
 96	const u32 mask = psci_has_ext_power_state() ?
 97					PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
 98					PSCI_0_2_POWER_STATE_TYPE_MASK;
 99
100	return state & mask;
101}
102
103bool psci_power_state_is_valid(u32 state)
104{
105	const u32 valid_mask = psci_has_ext_power_state() ?
106			       PSCI_1_0_EXT_POWER_STATE_MASK :
107			       PSCI_0_2_POWER_STATE_MASK;
108
109	return !(state & ~valid_mask);
110}
111
112static __always_inline unsigned long
113__invoke_psci_fn_hvc(unsigned long function_id,
114		     unsigned long arg0, unsigned long arg1,
115		     unsigned long arg2)
116{
117	struct arm_smccc_res res;
118
119	arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
120	return res.a0;
121}
122
123static __always_inline unsigned long
124__invoke_psci_fn_smc(unsigned long function_id,
125		     unsigned long arg0, unsigned long arg1,
126		     unsigned long arg2)
127{
128	struct arm_smccc_res res;
129
130	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
131	return res.a0;
132}
133
134static __always_inline int psci_to_linux_errno(int errno)
135{
136	switch (errno) {
137	case PSCI_RET_SUCCESS:
138		return 0;
139	case PSCI_RET_NOT_SUPPORTED:
140		return -EOPNOTSUPP;
141	case PSCI_RET_INVALID_PARAMS:
142	case PSCI_RET_INVALID_ADDRESS:
143		return -EINVAL;
144	case PSCI_RET_DENIED:
145		return -EPERM;
146	}
147
148	return -EINVAL;
149}
150
151static u32 psci_0_1_get_version(void)
152{
153	return PSCI_VERSION(0, 1);
154}
155
156static u32 psci_0_2_get_version(void)
157{
158	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
159}
160
161int psci_set_osi_mode(bool enable)
162{
163	unsigned long suspend_mode;
164	int err;
165
166	suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
167			PSCI_1_0_SUSPEND_MODE_PC;
168
169	err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
170	if (err < 0)
171		pr_info(FW_BUG "failed to set %s mode: %d\n",
172				enable ? "OSI" : "PC", err);
173	return psci_to_linux_errno(err);
174}
175
176static __always_inline int
177__psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
178{
179	int err;
180
181	err = invoke_psci_fn(fn, state, entry_point, 0);
182	return psci_to_linux_errno(err);
183}
184
185static __always_inline int
186psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
187{
188	return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
189				  state, entry_point);
190}
191
192static __always_inline int
193psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
194{
195	return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
196				  state, entry_point);
197}
198
199static int __psci_cpu_off(u32 fn, u32 state)
200{
201	int err;
202
203	err = invoke_psci_fn(fn, state, 0, 0);
204	return psci_to_linux_errno(err);
205}
206
207static int psci_0_1_cpu_off(u32 state)
208{
209	return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
210}
211
212static int psci_0_2_cpu_off(u32 state)
213{
214	return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
215}
216
217static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
218{
219	int err;
220
221	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
222	return psci_to_linux_errno(err);
223}
224
225static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
226{
227	return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
228}
229
230static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
231{
232	return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
233}
234
235static int __psci_migrate(u32 fn, unsigned long cpuid)
236{
237	int err;
238
239	err = invoke_psci_fn(fn, cpuid, 0, 0);
240	return psci_to_linux_errno(err);
241}
242
243static int psci_0_1_migrate(unsigned long cpuid)
244{
245	return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
246}
247
248static int psci_0_2_migrate(unsigned long cpuid)
249{
250	return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
251}
252
253static int psci_affinity_info(unsigned long target_affinity,
254		unsigned long lowest_affinity_level)
255{
256	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
257			      target_affinity, lowest_affinity_level, 0);
258}
259
260static int psci_migrate_info_type(void)
261{
262	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
263}
264
265static unsigned long psci_migrate_info_up_cpu(void)
266{
267	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
268			      0, 0, 0);
269}
270
271static void set_conduit(enum arm_smccc_conduit conduit)
272{
273	switch (conduit) {
274	case SMCCC_CONDUIT_HVC:
275		invoke_psci_fn = __invoke_psci_fn_hvc;
276		break;
277	case SMCCC_CONDUIT_SMC:
278		invoke_psci_fn = __invoke_psci_fn_smc;
279		break;
280	default:
281		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
282	}
283
284	psci_conduit = conduit;
285}
286
287static int get_set_conduit_method(const struct device_node *np)
288{
289	const char *method;
290
291	pr_info("probing for conduit method from DT.\n");
292
293	if (of_property_read_string(np, "method", &method)) {
294		pr_warn("missing \"method\" property\n");
295		return -ENXIO;
296	}
297
298	if (!strcmp("hvc", method)) {
299		set_conduit(SMCCC_CONDUIT_HVC);
300	} else if (!strcmp("smc", method)) {
301		set_conduit(SMCCC_CONDUIT_SMC);
302	} else {
303		pr_warn("invalid \"method\" property: %s\n", method);
304		return -EINVAL;
305	}
306	return 0;
307}
308
309static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
310			  void *data)
311{
312	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
313	    psci_system_reset2_supported) {
314		/*
315		 * reset_type[31] = 0 (architectural)
316		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
317		 * cookie = 0 (ignored by the implementation)
318		 */
319		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
320	} else {
321		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
322	}
323
324	return NOTIFY_DONE;
325}
326
327static struct notifier_block psci_sys_reset_nb = {
328	.notifier_call = psci_sys_reset,
329	.priority = 129,
330};
331
332static void psci_sys_poweroff(void)
333{
334	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
335}
336
337#ifdef CONFIG_HIBERNATION
338static int psci_sys_hibernate(struct sys_off_data *data)
339{
340	/*
341	 * If no hibernate type is specified SYSTEM_OFF2 defaults to selecting
342	 * HIBERNATE_OFF.
343	 *
344	 * There are hypervisors in the wild that do not align with the spec and
345	 * reject calls that explicitly provide a hibernate type. For
346	 * compatibility with these nonstandard implementations, pass 0 as the
347	 * type.
348	 */
349	if (system_entering_hibernation())
350		invoke_psci_fn(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2), 0, 0, 0);
351	return NOTIFY_DONE;
352}
353
354static int __init psci_hibernate_init(void)
355{
356	if (psci_system_off2_hibernate_supported) {
357		/* Higher priority than EFI shutdown, but only for hibernate */
358		register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
359					 SYS_OFF_PRIO_FIRMWARE + 2,
360					 psci_sys_hibernate, NULL);
361	}
362	return 0;
363}
364subsys_initcall(psci_hibernate_init);
365#endif
366
367static int psci_features(u32 psci_func_id)
368{
369	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
370			      psci_func_id, 0, 0);
371}
372
373#ifdef CONFIG_DEBUG_FS
374
375#define PSCI_ID(ver, _name) \
376	{ .fn = PSCI_##ver##_FN_##_name, .name = #_name, }
377#define PSCI_ID_NATIVE(ver, _name) \
378	{ .fn = PSCI_FN_NATIVE(ver, _name), .name = #_name, }
379
380/* A table of all optional functions */
381static const struct {
382	u32 fn;
383	const char *name;
384} psci_fn_ids[] = {
385	PSCI_ID_NATIVE(0_2, MIGRATE),
386	PSCI_ID(0_2, MIGRATE_INFO_TYPE),
387	PSCI_ID_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
388	PSCI_ID(1_0, CPU_FREEZE),
389	PSCI_ID_NATIVE(1_0, CPU_DEFAULT_SUSPEND),
390	PSCI_ID_NATIVE(1_0, NODE_HW_STATE),
391	PSCI_ID_NATIVE(1_0, SYSTEM_SUSPEND),
392	PSCI_ID(1_0, SET_SUSPEND_MODE),
393	PSCI_ID_NATIVE(1_0, STAT_RESIDENCY),
394	PSCI_ID_NATIVE(1_0, STAT_COUNT),
395	PSCI_ID_NATIVE(1_1, SYSTEM_RESET2),
396	PSCI_ID(1_1, MEM_PROTECT),
397	PSCI_ID_NATIVE(1_1, MEM_PROTECT_CHECK_RANGE),
398	PSCI_ID_NATIVE(1_3, SYSTEM_OFF2),
399};
400
401static int psci_debugfs_read(struct seq_file *s, void *data)
402{
403	int feature, type, i;
404	u32 ver;
405
406	ver = psci_ops.get_version();
407	seq_printf(s, "PSCIv%d.%d\n",
408		   PSCI_VERSION_MAJOR(ver),
409		   PSCI_VERSION_MINOR(ver));
410
411	/* PSCI_FEATURES is available only starting from 1.0 */
412	if (PSCI_VERSION_MAJOR(ver) < 1)
413		return 0;
414
415	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
416	if (feature != PSCI_RET_NOT_SUPPORTED) {
417		ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
418		seq_printf(s, "SMC Calling Convention v%d.%d\n",
419			   PSCI_VERSION_MAJOR(ver),
420			   PSCI_VERSION_MINOR(ver));
421	} else {
422		seq_puts(s, "SMC Calling Convention v1.0 is assumed\n");
423	}
424
425	feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
426	if (feature < 0) {
427		seq_printf(s, "PSCI_FEATURES(CPU_SUSPEND) error (%d)\n", feature);
428	} else {
429		seq_printf(s, "OSI is %ssupported\n",
430			   (feature & BIT(0)) ? "" : "not ");
431		seq_printf(s, "%s StateID format is used\n",
432			   (feature & BIT(1)) ? "Extended" : "Original");
433	}
434
435	type = psci_ops.migrate_info_type();
436	if (type == PSCI_0_2_TOS_UP_MIGRATE ||
437	    type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
438		unsigned long cpuid;
439
440		seq_printf(s, "Trusted OS %smigrate capable\n",
441			   type == PSCI_0_2_TOS_UP_NO_MIGRATE ? "not " : "");
442		cpuid = psci_migrate_info_up_cpu();
443		seq_printf(s, "Trusted OS resident on physical CPU 0x%lx (#%d)\n",
444			   cpuid, resident_cpu);
445	} else if (type == PSCI_0_2_TOS_MP) {
446		seq_puts(s, "Trusted OS migration not required\n");
447	} else {
448		if (type != PSCI_RET_NOT_SUPPORTED)
449			seq_printf(s, "MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
450	}
451
452	for (i = 0; i < ARRAY_SIZE(psci_fn_ids); i++) {
453		feature = psci_features(psci_fn_ids[i].fn);
454		if (feature == PSCI_RET_NOT_SUPPORTED)
455			continue;
456		if (feature < 0)
457			seq_printf(s, "PSCI_FEATURES(%s) error (%d)\n",
458				   psci_fn_ids[i].name, feature);
459		else
460			seq_printf(s, "%s is supported\n", psci_fn_ids[i].name);
461	}
462
463	return 0;
464}
465
466static int psci_debugfs_open(struct inode *inode, struct file *f)
467{
468	return single_open(f, psci_debugfs_read, NULL);
469}
470
471static const struct file_operations psci_debugfs_ops = {
472	.owner = THIS_MODULE,
473	.open = psci_debugfs_open,
474	.release = single_release,
475	.read = seq_read,
476	.llseek = seq_lseek
477};
478
479static int __init psci_debugfs_init(void)
480{
481	if (!invoke_psci_fn || !psci_ops.get_version)
482		return 0;
483
484	return PTR_ERR_OR_ZERO(debugfs_create_file("psci", 0444, NULL, NULL,
485						   &psci_debugfs_ops));
486}
487late_initcall(psci_debugfs_init)
488#endif
489
490#ifdef CONFIG_CPU_IDLE
491static noinstr int psci_suspend_finisher(unsigned long state)
492{
493	u32 power_state = state;
494	phys_addr_t pa_cpu_resume;
495
496	pa_cpu_resume = __pa_symbol_nodebug((unsigned long)cpu_resume);
497
498	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
499}
500
501int psci_cpu_suspend_enter(u32 state)
502{
503	int ret;
504
505	if (!psci_power_state_loses_context(state)) {
506		struct arm_cpuidle_irq_context context;
507
508		ct_cpuidle_enter();
509		arm_cpuidle_save_irq_context(&context);
510		ret = psci_ops.cpu_suspend(state, 0);
511		arm_cpuidle_restore_irq_context(&context);
512		ct_cpuidle_exit();
513	} else {
514		/*
515		 * ARM64 cpu_suspend() wants to do ct_cpuidle_*() itself.
516		 */
517		if (!IS_ENABLED(CONFIG_ARM64))
518			ct_cpuidle_enter();
519
520		ret = cpu_suspend(state, psci_suspend_finisher);
521
522		if (!IS_ENABLED(CONFIG_ARM64))
523			ct_cpuidle_exit();
524	}
525
526	return ret;
527}
528#endif
529
530static int psci_system_suspend(unsigned long unused)
531{
532	int err;
533	phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
534
535	err = invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
536			      pa_cpu_resume, 0, 0);
537	return psci_to_linux_errno(err);
538}
539
540static int psci_system_suspend_enter(suspend_state_t state)
541{
542	return cpu_suspend(0, psci_system_suspend);
543}
544
545static const struct platform_suspend_ops psci_suspend_ops = {
546	.valid          = suspend_valid_only_mem,
547	.enter          = psci_system_suspend_enter,
548};
549
550static void __init psci_init_system_reset2(void)
551{
552	int ret;
553
554	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
555
556	if (ret != PSCI_RET_NOT_SUPPORTED)
557		psci_system_reset2_supported = true;
558}
559
560static void __init psci_init_system_off2(void)
561{
562	int ret;
563
564	ret = psci_features(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2));
565	if (ret < 0)
566		return;
567
568	if (ret & PSCI_1_3_OFF_TYPE_HIBERNATE_OFF)
569		psci_system_off2_hibernate_supported = true;
570}
571
572static void __init psci_init_system_suspend(void)
573{
574	int ret;
575
576	if (!IS_ENABLED(CONFIG_SUSPEND))
577		return;
578
579	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
580
581	if (ret != PSCI_RET_NOT_SUPPORTED)
582		suspend_set_ops(&psci_suspend_ops);
583}
584
585static void __init psci_init_cpu_suspend(void)
586{
587	int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
588
589	if (feature != PSCI_RET_NOT_SUPPORTED)
590		psci_cpu_suspend_feature = feature;
591}
592
593/*
594 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
595 * return DENIED (which would be fatal).
596 */
597static void __init psci_init_migrate(void)
598{
599	unsigned long cpuid;
600	int type, cpu = -1;
601
602	type = psci_ops.migrate_info_type();
603
604	if (type == PSCI_0_2_TOS_MP) {
605		pr_info("Trusted OS migration not required\n");
606		return;
607	}
608
609	if (type == PSCI_RET_NOT_SUPPORTED) {
610		pr_info("MIGRATE_INFO_TYPE not supported.\n");
611		return;
612	}
613
614	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
615	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
616		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
617		return;
618	}
619
620	cpuid = psci_migrate_info_up_cpu();
621	if (cpuid & ~MPIDR_HWID_BITMASK) {
622		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
623			cpuid);
624		return;
625	}
626
627	cpu = get_logical_index(cpuid);
628	resident_cpu = cpu >= 0 ? cpu : -1;
629
630	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
631}
632
633static void __init psci_init_smccc(void)
634{
635	u32 ver = ARM_SMCCC_VERSION_1_0;
636	int feature;
637
638	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
639
640	if (feature != PSCI_RET_NOT_SUPPORTED) {
641		u32 ret;
642		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
643		if (ret >= ARM_SMCCC_VERSION_1_1) {
644			arm_smccc_version_init(ret, psci_conduit);
645			ver = ret;
646		}
647	}
648
649	/*
650	 * Conveniently, the SMCCC and PSCI versions are encoded the
651	 * same way. No, this isn't accidental.
652	 */
653	pr_info("SMC Calling Convention v%d.%d\n",
654		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
655
656}
657
658static void __init psci_0_2_set_functions(void)
659{
660	pr_info("Using standard PSCI v0.2 function IDs\n");
661
662	psci_ops = (struct psci_operations){
663		.get_version = psci_0_2_get_version,
664		.cpu_suspend = psci_0_2_cpu_suspend,
665		.cpu_off = psci_0_2_cpu_off,
666		.cpu_on = psci_0_2_cpu_on,
667		.migrate = psci_0_2_migrate,
668		.affinity_info = psci_affinity_info,
669		.migrate_info_type = psci_migrate_info_type,
670	};
671
672	register_restart_handler(&psci_sys_reset_nb);
673
674	pm_power_off = psci_sys_poweroff;
675}
676
677/*
678 * Probe function for PSCI firmware versions >= 0.2
679 */
680static int __init psci_probe(void)
681{
682	u32 ver = psci_0_2_get_version();
683
684	pr_info("PSCIv%d.%d detected in firmware.\n",
685			PSCI_VERSION_MAJOR(ver),
686			PSCI_VERSION_MINOR(ver));
687
688	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
689		pr_err("Conflicting PSCI version detected.\n");
690		return -EINVAL;
691	}
692
693	psci_0_2_set_functions();
694
695	psci_init_migrate();
696
697	if (PSCI_VERSION_MAJOR(ver) >= 1) {
698		psci_init_smccc();
699		psci_init_cpu_suspend();
700		psci_init_system_suspend();
701		psci_init_system_reset2();
702		psci_init_system_off2();
703		kvm_init_hyp_services();
704	}
705
706	return 0;
707}
708
709typedef int (*psci_initcall_t)(const struct device_node *);
710
711/*
712 * PSCI init function for PSCI versions >=0.2
713 *
714 * Probe based on PSCI PSCI_VERSION function
715 */
716static int __init psci_0_2_init(const struct device_node *np)
717{
718	int err;
719
720	err = get_set_conduit_method(np);
721	if (err)
722		return err;
723
724	/*
725	 * Starting with v0.2, the PSCI specification introduced a call
726	 * (PSCI_VERSION) that allows probing the firmware version, so
727	 * that PSCI function IDs and version specific initialization
728	 * can be carried out according to the specific version reported
729	 * by firmware
730	 */
731	return psci_probe();
732}
733
734/*
735 * PSCI < v0.2 get PSCI Function IDs via DT.
736 */
737static int __init psci_0_1_init(const struct device_node *np)
738{
739	u32 id;
740	int err;
741
742	err = get_set_conduit_method(np);
743	if (err)
744		return err;
745
746	pr_info("Using PSCI v0.1 Function IDs from DT\n");
747
748	psci_ops.get_version = psci_0_1_get_version;
749
750	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
751		psci_0_1_function_ids.cpu_suspend = id;
752		psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
753	}
754
755	if (!of_property_read_u32(np, "cpu_off", &id)) {
756		psci_0_1_function_ids.cpu_off = id;
757		psci_ops.cpu_off = psci_0_1_cpu_off;
758	}
759
760	if (!of_property_read_u32(np, "cpu_on", &id)) {
761		psci_0_1_function_ids.cpu_on = id;
762		psci_ops.cpu_on = psci_0_1_cpu_on;
763	}
764
765	if (!of_property_read_u32(np, "migrate", &id)) {
766		psci_0_1_function_ids.migrate = id;
767		psci_ops.migrate = psci_0_1_migrate;
768	}
769
770	return 0;
771}
772
773static int __init psci_1_0_init(const struct device_node *np)
774{
775	int err;
776
777	err = psci_0_2_init(np);
778	if (err)
779		return err;
780
781	if (psci_has_osi_support()) {
782		pr_info("OSI mode supported.\n");
783
784		/* Default to PC mode. */
785		psci_set_osi_mode(false);
786	}
787
788	return 0;
789}
790
791static const struct of_device_id psci_of_match[] __initconst = {
792	{ .compatible = "arm,psci",	.data = psci_0_1_init},
793	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
794	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
795	{},
796};
797
798int __init psci_dt_init(void)
799{
800	struct device_node *np;
801	const struct of_device_id *matched_np;
802	psci_initcall_t init_fn;
803	int ret;
804
805	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
806
807	if (!np || !of_device_is_available(np))
808		return -ENODEV;
809
810	init_fn = (psci_initcall_t)matched_np->data;
811	ret = init_fn(np);
812
813	of_node_put(np);
814	return ret;
815}
816
817#ifdef CONFIG_ACPI
818/*
819 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
820 * explicitly clarified in SBBR
821 */
822int __init psci_acpi_init(void)
823{
824	if (!acpi_psci_present()) {
825		pr_info("is not implemented in ACPI.\n");
826		return -EOPNOTSUPP;
827	}
828
829	pr_info("probing for conduit method from ACPI.\n");
830
831	if (acpi_psci_use_hvc())
832		set_conduit(SMCCC_CONDUIT_HVC);
833	else
834		set_conduit(SMCCC_CONDUIT_SMC);
835
836	return psci_probe();
837}
838#endif