xref: /linux/drivers/firmware/psci/psci.c (revision 02680c23d7b3febe45ea3d4f9818c2b2dc89020a) 
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/hypervisor.h>
27 #include <asm/system_misc.h>
28 #include <asm/smp_plat.h>
29 #include <asm/suspend.h>
30 
31 /*
32  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
33  * calls it is necessary to use SMC64 to pass or return 64-bit values.
34  * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
35  * (native-width) function ID.
36  */
37 #ifdef CONFIG_64BIT
38 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN64_##name
39 #else
40 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN_##name
41 #endif
42 
43 /*
44  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
45  * calls to its resident CPU, so we must avoid issuing those. We never migrate
46  * a Trusted OS even if it claims to be capable of migration -- doing so will
47  * require cooperation with a Trusted OS driver.
48  */
49 static int resident_cpu = -1;
50 struct psci_operations psci_ops;
51 static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
52 
53 bool psci_tos_resident_on(int cpu)
54 {
55 	return cpu == resident_cpu;
56 }
57 
58 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
59 				unsigned long, unsigned long);
60 static psci_fn *invoke_psci_fn;
61 
62 static struct psci_0_1_function_ids psci_0_1_function_ids;
63 
64 struct psci_0_1_function_ids get_psci_0_1_function_ids(void)
65 {
66 	return psci_0_1_function_ids;
67 }
68 
69 #define PSCI_0_2_POWER_STATE_MASK		\
70 				(PSCI_0_2_POWER_STATE_ID_MASK | \
71 				PSCI_0_2_POWER_STATE_TYPE_MASK | \
72 				PSCI_0_2_POWER_STATE_AFFL_MASK)
73 
74 #define PSCI_1_0_EXT_POWER_STATE_MASK		\
75 				(PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
76 				PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
77 
78 static u32 psci_cpu_suspend_feature;
79 static bool psci_system_reset2_supported;
80 
81 static inline bool psci_has_ext_power_state(void)
82 {
83 	return psci_cpu_suspend_feature &
84 				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
85 }
86 
87 bool psci_has_osi_support(void)
88 {
89 	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
90 }
91 
92 static inline bool psci_power_state_loses_context(u32 state)
93 {
94 	const u32 mask = psci_has_ext_power_state() ?
95 					PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
96 					PSCI_0_2_POWER_STATE_TYPE_MASK;
97 
98 	return state & mask;
99 }
100 
101 bool psci_power_state_is_valid(u32 state)
102 {
103 	const u32 valid_mask = psci_has_ext_power_state() ?
104 			       PSCI_1_0_EXT_POWER_STATE_MASK :
105 			       PSCI_0_2_POWER_STATE_MASK;
106 
107 	return !(state & ~valid_mask);
108 }
109 
110 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
111 			unsigned long arg0, unsigned long arg1,
112 			unsigned long arg2)
113 {
114 	struct arm_smccc_res res;
115 
116 	arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
117 	return res.a0;
118 }
119 
120 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
121 			unsigned long arg0, unsigned long arg1,
122 			unsigned long arg2)
123 {
124 	struct arm_smccc_res res;
125 
126 	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
127 	return res.a0;
128 }
129 
130 static int psci_to_linux_errno(int errno)
131 {
132 	switch (errno) {
133 	case PSCI_RET_SUCCESS:
134 		return 0;
135 	case PSCI_RET_NOT_SUPPORTED:
136 		return -EOPNOTSUPP;
137 	case PSCI_RET_INVALID_PARAMS:
138 	case PSCI_RET_INVALID_ADDRESS:
139 		return -EINVAL;
140 	case PSCI_RET_DENIED:
141 		return -EPERM;
142 	}
143 
144 	return -EINVAL;
145 }
146 
147 static u32 psci_0_1_get_version(void)
148 {
149 	return PSCI_VERSION(0, 1);
150 }
151 
152 static u32 psci_0_2_get_version(void)
153 {
154 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
155 }
156 
157 int psci_set_osi_mode(bool enable)
158 {
159 	unsigned long suspend_mode;
160 	int err;
161 
162 	suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
163 			PSCI_1_0_SUSPEND_MODE_PC;
164 
165 	err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
166 	return psci_to_linux_errno(err);
167 }
168 
169 static int __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
170 {
171 	int err;
172 
173 	err = invoke_psci_fn(fn, state, entry_point, 0);
174 	return psci_to_linux_errno(err);
175 }
176 
177 static int psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
178 {
179 	return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
180 				  state, entry_point);
181 }
182 
183 static int psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
184 {
185 	return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
186 				  state, entry_point);
187 }
188 
189 static int __psci_cpu_off(u32 fn, u32 state)
190 {
191 	int err;
192 
193 	err = invoke_psci_fn(fn, state, 0, 0);
194 	return psci_to_linux_errno(err);
195 }
196 
197 static int psci_0_1_cpu_off(u32 state)
198 {
199 	return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
200 }
201 
202 static int psci_0_2_cpu_off(u32 state)
203 {
204 	return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
205 }
206 
207 static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
208 {
209 	int err;
210 
211 	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
212 	return psci_to_linux_errno(err);
213 }
214 
215 static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
216 {
217 	return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
218 }
219 
220 static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
221 {
222 	return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
223 }
224 
225 static int __psci_migrate(u32 fn, unsigned long cpuid)
226 {
227 	int err;
228 
229 	err = invoke_psci_fn(fn, cpuid, 0, 0);
230 	return psci_to_linux_errno(err);
231 }
232 
233 static int psci_0_1_migrate(unsigned long cpuid)
234 {
235 	return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
236 }
237 
238 static int psci_0_2_migrate(unsigned long cpuid)
239 {
240 	return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
241 }
242 
243 static int psci_affinity_info(unsigned long target_affinity,
244 		unsigned long lowest_affinity_level)
245 {
246 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
247 			      target_affinity, lowest_affinity_level, 0);
248 }
249 
250 static int psci_migrate_info_type(void)
251 {
252 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
253 }
254 
255 static unsigned long psci_migrate_info_up_cpu(void)
256 {
257 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
258 			      0, 0, 0);
259 }
260 
261 static void set_conduit(enum arm_smccc_conduit conduit)
262 {
263 	switch (conduit) {
264 	case SMCCC_CONDUIT_HVC:
265 		invoke_psci_fn = __invoke_psci_fn_hvc;
266 		break;
267 	case SMCCC_CONDUIT_SMC:
268 		invoke_psci_fn = __invoke_psci_fn_smc;
269 		break;
270 	default:
271 		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
272 	}
273 
274 	psci_conduit = conduit;
275 }
276 
277 static int get_set_conduit_method(struct device_node *np)
278 {
279 	const char *method;
280 
281 	pr_info("probing for conduit method from DT.\n");
282 
283 	if (of_property_read_string(np, "method", &method)) {
284 		pr_warn("missing \"method\" property\n");
285 		return -ENXIO;
286 	}
287 
288 	if (!strcmp("hvc", method)) {
289 		set_conduit(SMCCC_CONDUIT_HVC);
290 	} else if (!strcmp("smc", method)) {
291 		set_conduit(SMCCC_CONDUIT_SMC);
292 	} else {
293 		pr_warn("invalid \"method\" property: %s\n", method);
294 		return -EINVAL;
295 	}
296 	return 0;
297 }
298 
299 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
300 {
301 	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
302 	    psci_system_reset2_supported) {
303 		/*
304 		 * reset_type[31] = 0 (architectural)
305 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
306 		 * cookie = 0 (ignored by the implementation)
307 		 */
308 		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
309 	} else {
310 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
311 	}
312 }
313 
314 static void psci_sys_poweroff(void)
315 {
316 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
317 }
318 
319 static int __init psci_features(u32 psci_func_id)
320 {
321 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
322 			      psci_func_id, 0, 0);
323 }
324 
325 #ifdef CONFIG_CPU_IDLE
326 static int psci_suspend_finisher(unsigned long state)
327 {
328 	u32 power_state = state;
329 	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
330 
331 	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
332 }
333 
334 int psci_cpu_suspend_enter(u32 state)
335 {
336 	int ret;
337 
338 	if (!psci_power_state_loses_context(state))
339 		ret = psci_ops.cpu_suspend(state, 0);
340 	else
341 		ret = cpu_suspend(state, psci_suspend_finisher);
342 
343 	return ret;
344 }
345 #endif
346 
347 static int psci_system_suspend(unsigned long unused)
348 {
349 	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
350 
351 	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
352 			      pa_cpu_resume, 0, 0);
353 }
354 
355 static int psci_system_suspend_enter(suspend_state_t state)
356 {
357 	return cpu_suspend(0, psci_system_suspend);
358 }
359 
360 static const struct platform_suspend_ops psci_suspend_ops = {
361 	.valid          = suspend_valid_only_mem,
362 	.enter          = psci_system_suspend_enter,
363 };
364 
365 static void __init psci_init_system_reset2(void)
366 {
367 	int ret;
368 
369 	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
370 
371 	if (ret != PSCI_RET_NOT_SUPPORTED)
372 		psci_system_reset2_supported = true;
373 }
374 
375 static void __init psci_init_system_suspend(void)
376 {
377 	int ret;
378 
379 	if (!IS_ENABLED(CONFIG_SUSPEND))
380 		return;
381 
382 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
383 
384 	if (ret != PSCI_RET_NOT_SUPPORTED)
385 		suspend_set_ops(&psci_suspend_ops);
386 }
387 
388 static void __init psci_init_cpu_suspend(void)
389 {
390 	int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
391 
392 	if (feature != PSCI_RET_NOT_SUPPORTED)
393 		psci_cpu_suspend_feature = feature;
394 }
395 
396 /*
397  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
398  * return DENIED (which would be fatal).
399  */
400 static void __init psci_init_migrate(void)
401 {
402 	unsigned long cpuid;
403 	int type, cpu = -1;
404 
405 	type = psci_ops.migrate_info_type();
406 
407 	if (type == PSCI_0_2_TOS_MP) {
408 		pr_info("Trusted OS migration not required\n");
409 		return;
410 	}
411 
412 	if (type == PSCI_RET_NOT_SUPPORTED) {
413 		pr_info("MIGRATE_INFO_TYPE not supported.\n");
414 		return;
415 	}
416 
417 	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
418 	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
419 		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
420 		return;
421 	}
422 
423 	cpuid = psci_migrate_info_up_cpu();
424 	if (cpuid & ~MPIDR_HWID_BITMASK) {
425 		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
426 			cpuid);
427 		return;
428 	}
429 
430 	cpu = get_logical_index(cpuid);
431 	resident_cpu = cpu >= 0 ? cpu : -1;
432 
433 	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
434 }
435 
436 static void __init psci_init_smccc(void)
437 {
438 	u32 ver = ARM_SMCCC_VERSION_1_0;
439 	int feature;
440 
441 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
442 
443 	if (feature != PSCI_RET_NOT_SUPPORTED) {
444 		u32 ret;
445 		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
446 		if (ret >= ARM_SMCCC_VERSION_1_1) {
447 			arm_smccc_version_init(ret, psci_conduit);
448 			ver = ret;
449 		}
450 	}
451 
452 	/*
453 	 * Conveniently, the SMCCC and PSCI versions are encoded the
454 	 * same way. No, this isn't accidental.
455 	 */
456 	pr_info("SMC Calling Convention v%d.%d\n",
457 		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
458 
459 }
460 
461 static void __init psci_0_2_set_functions(void)
462 {
463 	pr_info("Using standard PSCI v0.2 function IDs\n");
464 
465 	psci_ops = (struct psci_operations){
466 		.get_version = psci_0_2_get_version,
467 		.cpu_suspend = psci_0_2_cpu_suspend,
468 		.cpu_off = psci_0_2_cpu_off,
469 		.cpu_on = psci_0_2_cpu_on,
470 		.migrate = psci_0_2_migrate,
471 		.affinity_info = psci_affinity_info,
472 		.migrate_info_type = psci_migrate_info_type,
473 	};
474 
475 	arm_pm_restart = psci_sys_reset;
476 
477 	pm_power_off = psci_sys_poweroff;
478 }
479 
480 /*
481  * Probe function for PSCI firmware versions >= 0.2
482  */
483 static int __init psci_probe(void)
484 {
485 	u32 ver = psci_0_2_get_version();
486 
487 	pr_info("PSCIv%d.%d detected in firmware.\n",
488 			PSCI_VERSION_MAJOR(ver),
489 			PSCI_VERSION_MINOR(ver));
490 
491 	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
492 		pr_err("Conflicting PSCI version detected.\n");
493 		return -EINVAL;
494 	}
495 
496 	psci_0_2_set_functions();
497 
498 	psci_init_migrate();
499 
500 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
501 		psci_init_smccc();
502 		psci_init_cpu_suspend();
503 		psci_init_system_suspend();
504 		psci_init_system_reset2();
505 		kvm_init_hyp_services();
506 	}
507 
508 	return 0;
509 }
510 
511 typedef int (*psci_initcall_t)(const struct device_node *);
512 
513 /*
514  * PSCI init function for PSCI versions >=0.2
515  *
516  * Probe based on PSCI PSCI_VERSION function
517  */
518 static int __init psci_0_2_init(struct device_node *np)
519 {
520 	int err;
521 
522 	err = get_set_conduit_method(np);
523 	if (err)
524 		return err;
525 
526 	/*
527 	 * Starting with v0.2, the PSCI specification introduced a call
528 	 * (PSCI_VERSION) that allows probing the firmware version, so
529 	 * that PSCI function IDs and version specific initialization
530 	 * can be carried out according to the specific version reported
531 	 * by firmware
532 	 */
533 	return psci_probe();
534 }
535 
536 /*
537  * PSCI < v0.2 get PSCI Function IDs via DT.
538  */
539 static int __init psci_0_1_init(struct device_node *np)
540 {
541 	u32 id;
542 	int err;
543 
544 	err = get_set_conduit_method(np);
545 	if (err)
546 		return err;
547 
548 	pr_info("Using PSCI v0.1 Function IDs from DT\n");
549 
550 	psci_ops.get_version = psci_0_1_get_version;
551 
552 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
553 		psci_0_1_function_ids.cpu_suspend = id;
554 		psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
555 	}
556 
557 	if (!of_property_read_u32(np, "cpu_off", &id)) {
558 		psci_0_1_function_ids.cpu_off = id;
559 		psci_ops.cpu_off = psci_0_1_cpu_off;
560 	}
561 
562 	if (!of_property_read_u32(np, "cpu_on", &id)) {
563 		psci_0_1_function_ids.cpu_on = id;
564 		psci_ops.cpu_on = psci_0_1_cpu_on;
565 	}
566 
567 	if (!of_property_read_u32(np, "migrate", &id)) {
568 		psci_0_1_function_ids.migrate = id;
569 		psci_ops.migrate = psci_0_1_migrate;
570 	}
571 
572 	return 0;
573 }
574 
575 static int __init psci_1_0_init(struct device_node *np)
576 {
577 	int err;
578 
579 	err = psci_0_2_init(np);
580 	if (err)
581 		return err;
582 
583 	if (psci_has_osi_support()) {
584 		pr_info("OSI mode supported.\n");
585 
586 		/* Default to PC mode. */
587 		psci_set_osi_mode(false);
588 	}
589 
590 	return 0;
591 }
592 
593 static const struct of_device_id psci_of_match[] __initconst = {
594 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
595 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
596 	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
597 	{},
598 };
599 
600 int __init psci_dt_init(void)
601 {
602 	struct device_node *np;
603 	const struct of_device_id *matched_np;
604 	psci_initcall_t init_fn;
605 	int ret;
606 
607 	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
608 
609 	if (!np || !of_device_is_available(np))
610 		return -ENODEV;
611 
612 	init_fn = (psci_initcall_t)matched_np->data;
613 	ret = init_fn(np);
614 
615 	of_node_put(np);
616 	return ret;
617 }
618 
619 #ifdef CONFIG_ACPI
620 /*
621  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
622  * explicitly clarified in SBBR
623  */
624 int __init psci_acpi_init(void)
625 {
626 	if (!acpi_psci_present()) {
627 		pr_info("is not implemented in ACPI.\n");
628 		return -EOPNOTSUPP;
629 	}
630 
631 	pr_info("probing for conduit method from ACPI.\n");
632 
633 	if (acpi_psci_use_hvc())
634 		set_conduit(SMCCC_CONDUIT_HVC);
635 	else
636 		set_conduit(SMCCC_CONDUIT_SMC);
637 
638 	return psci_probe();
639 }
640 #endif
641