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/errno.h>
13#include <linux/linkage.h>
14#include <linux/of.h>
15#include <linux/pm.h>
16#include <linux/printk.h>
17#include <linux/psci.h>
18#include <linux/reboot.h>
19#include <linux/slab.h>
20#include <linux/suspend.h>
21
22#include <uapi/linux/psci.h>
23
24#include <asm/cpuidle.h>
25#include <asm/cputype.h>
26#include <asm/system_misc.h>
27#include <asm/smp_plat.h>
28#include <asm/suspend.h>
29
30/*
31 * While a 64-bit OS can make calls with SMC32 calling conventions, for some
32 * calls it is necessary to use SMC64 to pass or return 64-bit values.
33 * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
34 * (native-width) function ID.
35 */
36#ifdef CONFIG_64BIT
37#define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN64_##name
38#else
39#define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN_##name
40#endif
41
42/*
43 * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
44 * calls to its resident CPU, so we must avoid issuing those. We never migrate
45 * a Trusted OS even if it claims to be capable of migration -- doing so will
46 * require cooperation with a Trusted OS driver.
47 */
48static int resident_cpu = -1;
49struct psci_operations psci_ops;
50static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
51
52bool psci_tos_resident_on(int cpu)
53{
54	return cpu == resident_cpu;
55}
56
57typedef unsigned long (psci_fn)(unsigned long, unsigned long,
58				unsigned long, unsigned long);
59static psci_fn *invoke_psci_fn;
60
61enum psci_function {
62	PSCI_FN_CPU_SUSPEND,
63	PSCI_FN_CPU_ON,
64	PSCI_FN_CPU_OFF,
65	PSCI_FN_MIGRATE,
66	PSCI_FN_MAX,
67};
68
69static u32 psci_function_id[PSCI_FN_MAX];
70
71#define PSCI_0_2_POWER_STATE_MASK		\
72				(PSCI_0_2_POWER_STATE_ID_MASK | \
73				PSCI_0_2_POWER_STATE_TYPE_MASK | \
74				PSCI_0_2_POWER_STATE_AFFL_MASK)
75
76#define PSCI_1_0_EXT_POWER_STATE_MASK		\
77				(PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
78				PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
79
80static u32 psci_cpu_suspend_feature;
81static bool psci_system_reset2_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 unsigned long __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
122static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
123			unsigned long arg0, unsigned long arg1,
124			unsigned long arg2)
125{
126	struct arm_smccc_res res;
127
128	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
129	return res.a0;
130}
131
132static int psci_to_linux_errno(int errno)
133{
134	switch (errno) {
135	case PSCI_RET_SUCCESS:
136		return 0;
137	case PSCI_RET_NOT_SUPPORTED:
138		return -EOPNOTSUPP;
139	case PSCI_RET_INVALID_PARAMS:
140	case PSCI_RET_INVALID_ADDRESS:
141		return -EINVAL;
142	case PSCI_RET_DENIED:
143		return -EPERM;
144	};
145
146	return -EINVAL;
147}
148
149static u32 psci_get_version(void)
150{
151	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
152}
153
154int psci_set_osi_mode(bool enable)
155{
156	unsigned long suspend_mode;
157	int err;
158
159	suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
160			PSCI_1_0_SUSPEND_MODE_PC;
161
162	err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
163	return psci_to_linux_errno(err);
164}
165
166static int psci_cpu_suspend(u32 state, unsigned long entry_point)
167{
168	int err;
169	u32 fn;
170
171	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
172	err = invoke_psci_fn(fn, state, entry_point, 0);
173	return psci_to_linux_errno(err);
174}
175
176static int psci_cpu_off(u32 state)
177{
178	int err;
179	u32 fn;
180
181	fn = psci_function_id[PSCI_FN_CPU_OFF];
182	err = invoke_psci_fn(fn, state, 0, 0);
183	return psci_to_linux_errno(err);
184}
185
186static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
187{
188	int err;
189	u32 fn;
190
191	fn = psci_function_id[PSCI_FN_CPU_ON];
192	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
193	return psci_to_linux_errno(err);
194}
195
196static int psci_migrate(unsigned long cpuid)
197{
198	int err;
199	u32 fn;
200
201	fn = psci_function_id[PSCI_FN_MIGRATE];
202	err = invoke_psci_fn(fn, cpuid, 0, 0);
203	return psci_to_linux_errno(err);
204}
205
206static int psci_affinity_info(unsigned long target_affinity,
207		unsigned long lowest_affinity_level)
208{
209	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
210			      target_affinity, lowest_affinity_level, 0);
211}
212
213static int psci_migrate_info_type(void)
214{
215	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
216}
217
218static unsigned long psci_migrate_info_up_cpu(void)
219{
220	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
221			      0, 0, 0);
222}
223
224static void set_conduit(enum arm_smccc_conduit conduit)
225{
226	switch (conduit) {
227	case SMCCC_CONDUIT_HVC:
228		invoke_psci_fn = __invoke_psci_fn_hvc;
229		break;
230	case SMCCC_CONDUIT_SMC:
231		invoke_psci_fn = __invoke_psci_fn_smc;
232		break;
233	default:
234		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
235	}
236
237	psci_conduit = conduit;
238}
239
240static int get_set_conduit_method(struct device_node *np)
241{
242	const char *method;
243
244	pr_info("probing for conduit method from DT.\n");
245
246	if (of_property_read_string(np, "method", &method)) {
247		pr_warn("missing \"method\" property\n");
248		return -ENXIO;
249	}
250
251	if (!strcmp("hvc", method)) {
252		set_conduit(SMCCC_CONDUIT_HVC);
253	} else if (!strcmp("smc", method)) {
254		set_conduit(SMCCC_CONDUIT_SMC);
255	} else {
256		pr_warn("invalid \"method\" property: %s\n", method);
257		return -EINVAL;
258	}
259	return 0;
260}
261
262static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
263{
264	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
265	    psci_system_reset2_supported) {
266		/*
267		 * reset_type[31] = 0 (architectural)
268		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
269		 * cookie = 0 (ignored by the implementation)
270		 */
271		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
272	} else {
273		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
274	}
275}
276
277static void psci_sys_poweroff(void)
278{
279	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
280}
281
282static int __init psci_features(u32 psci_func_id)
283{
284	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
285			      psci_func_id, 0, 0);
286}
287
288#ifdef CONFIG_CPU_IDLE
289static int psci_suspend_finisher(unsigned long state)
290{
291	u32 power_state = state;
292	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
293
294	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
295}
296
297int psci_cpu_suspend_enter(u32 state)
298{
299	int ret;
300
301	if (!psci_power_state_loses_context(state))
302		ret = psci_ops.cpu_suspend(state, 0);
303	else
304		ret = cpu_suspend(state, psci_suspend_finisher);
305
306	return ret;
307}
308#endif
309
310static int psci_system_suspend(unsigned long unused)
311{
312	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
313
314	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
315			      pa_cpu_resume, 0, 0);
316}
317
318static int psci_system_suspend_enter(suspend_state_t state)
319{
320	return cpu_suspend(0, psci_system_suspend);
321}
322
323static const struct platform_suspend_ops psci_suspend_ops = {
324	.valid          = suspend_valid_only_mem,
325	.enter          = psci_system_suspend_enter,
326};
327
328static void __init psci_init_system_reset2(void)
329{
330	int ret;
331
332	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
333
334	if (ret != PSCI_RET_NOT_SUPPORTED)
335		psci_system_reset2_supported = true;
336}
337
338static void __init psci_init_system_suspend(void)
339{
340	int ret;
341
342	if (!IS_ENABLED(CONFIG_SUSPEND))
343		return;
344
345	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
346
347	if (ret != PSCI_RET_NOT_SUPPORTED)
348		suspend_set_ops(&psci_suspend_ops);
349}
350
351static void __init psci_init_cpu_suspend(void)
352{
353	int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
354
355	if (feature != PSCI_RET_NOT_SUPPORTED)
356		psci_cpu_suspend_feature = feature;
357}
358
359/*
360 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
361 * return DENIED (which would be fatal).
362 */
363static void __init psci_init_migrate(void)
364{
365	unsigned long cpuid;
366	int type, cpu = -1;
367
368	type = psci_ops.migrate_info_type();
369
370	if (type == PSCI_0_2_TOS_MP) {
371		pr_info("Trusted OS migration not required\n");
372		return;
373	}
374
375	if (type == PSCI_RET_NOT_SUPPORTED) {
376		pr_info("MIGRATE_INFO_TYPE not supported.\n");
377		return;
378	}
379
380	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
381	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
382		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
383		return;
384	}
385
386	cpuid = psci_migrate_info_up_cpu();
387	if (cpuid & ~MPIDR_HWID_BITMASK) {
388		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
389			cpuid);
390		return;
391	}
392
393	cpu = get_logical_index(cpuid);
394	resident_cpu = cpu >= 0 ? cpu : -1;
395
396	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
397}
398
399static void __init psci_init_smccc(void)
400{
401	u32 ver = ARM_SMCCC_VERSION_1_0;
402	int feature;
403
404	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
405
406	if (feature != PSCI_RET_NOT_SUPPORTED) {
407		u32 ret;
408		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
409		if (ret >= ARM_SMCCC_VERSION_1_1) {
410			arm_smccc_version_init(ret, psci_conduit);
411			ver = ret;
412		}
413	}
414
415	/*
416	 * Conveniently, the SMCCC and PSCI versions are encoded the
417	 * same way. No, this isn't accidental.
418	 */
419	pr_info("SMC Calling Convention v%d.%d\n",
420		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
421
422}
423
424static void __init psci_0_2_set_functions(void)
425{
426	pr_info("Using standard PSCI v0.2 function IDs\n");
427	psci_ops.get_version = psci_get_version;
428
429	psci_function_id[PSCI_FN_CPU_SUSPEND] =
430					PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
431	psci_ops.cpu_suspend = psci_cpu_suspend;
432
433	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
434	psci_ops.cpu_off = psci_cpu_off;
435
436	psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
437	psci_ops.cpu_on = psci_cpu_on;
438
439	psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
440	psci_ops.migrate = psci_migrate;
441
442	psci_ops.affinity_info = psci_affinity_info;
443
444	psci_ops.migrate_info_type = psci_migrate_info_type;
445
446	arm_pm_restart = psci_sys_reset;
447
448	pm_power_off = psci_sys_poweroff;
449}
450
451/*
452 * Probe function for PSCI firmware versions >= 0.2
453 */
454static int __init psci_probe(void)
455{
456	u32 ver = psci_get_version();
457
458	pr_info("PSCIv%d.%d detected in firmware.\n",
459			PSCI_VERSION_MAJOR(ver),
460			PSCI_VERSION_MINOR(ver));
461
462	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
463		pr_err("Conflicting PSCI version detected.\n");
464		return -EINVAL;
465	}
466
467	psci_0_2_set_functions();
468
469	psci_init_migrate();
470
471	if (PSCI_VERSION_MAJOR(ver) >= 1) {
472		psci_init_smccc();
473		psci_init_cpu_suspend();
474		psci_init_system_suspend();
475		psci_init_system_reset2();
476	}
477
478	return 0;
479}
480
481typedef int (*psci_initcall_t)(const struct device_node *);
482
483/*
484 * PSCI init function for PSCI versions >=0.2
485 *
486 * Probe based on PSCI PSCI_VERSION function
487 */
488static int __init psci_0_2_init(struct device_node *np)
489{
490	int err;
491
492	err = get_set_conduit_method(np);
493	if (err)
494		return err;
495
496	/*
497	 * Starting with v0.2, the PSCI specification introduced a call
498	 * (PSCI_VERSION) that allows probing the firmware version, so
499	 * that PSCI function IDs and version specific initialization
500	 * can be carried out according to the specific version reported
501	 * by firmware
502	 */
503	return psci_probe();
504}
505
506/*
507 * PSCI < v0.2 get PSCI Function IDs via DT.
508 */
509static int __init psci_0_1_init(struct device_node *np)
510{
511	u32 id;
512	int err;
513
514	err = get_set_conduit_method(np);
515	if (err)
516		return err;
517
518	pr_info("Using PSCI v0.1 Function IDs from DT\n");
519
520	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
521		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
522		psci_ops.cpu_suspend = psci_cpu_suspend;
523	}
524
525	if (!of_property_read_u32(np, "cpu_off", &id)) {
526		psci_function_id[PSCI_FN_CPU_OFF] = id;
527		psci_ops.cpu_off = psci_cpu_off;
528	}
529
530	if (!of_property_read_u32(np, "cpu_on", &id)) {
531		psci_function_id[PSCI_FN_CPU_ON] = id;
532		psci_ops.cpu_on = psci_cpu_on;
533	}
534
535	if (!of_property_read_u32(np, "migrate", &id)) {
536		psci_function_id[PSCI_FN_MIGRATE] = id;
537		psci_ops.migrate = psci_migrate;
538	}
539
540	return 0;
541}
542
543static int __init psci_1_0_init(struct device_node *np)
544{
545	int err;
546
547	err = psci_0_2_init(np);
548	if (err)
549		return err;
550
551	if (psci_has_osi_support()) {
552		pr_info("OSI mode supported.\n");
553
554		/* Default to PC mode. */
555		psci_set_osi_mode(false);
556	}
557
558	return 0;
559}
560
561static const struct of_device_id psci_of_match[] __initconst = {
562	{ .compatible = "arm,psci",	.data = psci_0_1_init},
563	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
564	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
565	{},
566};
567
568int __init psci_dt_init(void)
569{
570	struct device_node *np;
571	const struct of_device_id *matched_np;
572	psci_initcall_t init_fn;
573	int ret;
574
575	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
576
577	if (!np || !of_device_is_available(np))
578		return -ENODEV;
579
580	init_fn = (psci_initcall_t)matched_np->data;
581	ret = init_fn(np);
582
583	of_node_put(np);
584	return ret;
585}
586
587#ifdef CONFIG_ACPI
588/*
589 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
590 * explicitly clarified in SBBR
591 */
592int __init psci_acpi_init(void)
593{
594	if (!acpi_psci_present()) {
595		pr_info("is not implemented in ACPI.\n");
596		return -EOPNOTSUPP;
597	}
598
599	pr_info("probing for conduit method from ACPI.\n");
600
601	if (acpi_psci_use_hvc())
602		set_conduit(SMCCC_CONDUIT_HVC);
603	else
604		set_conduit(SMCCC_CONDUIT_SMC);
605
606	return psci_probe();
607}
608#endif
609