xref: /openbmc/linux/drivers/firmware/psci/psci.c (revision 3aa139aa9fdc138a84243dc49dc18d9b40e1c6e4) 
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  */
48 static int resident_cpu = -1;
49 struct psci_operations psci_ops;
50 static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
51 
52 bool psci_tos_resident_on(int cpu)
53 {
54 	return cpu == resident_cpu;
55 }
56 
57 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
58 				unsigned long, unsigned long);
59 static psci_fn *invoke_psci_fn;
60 
61 static struct psci_0_1_function_ids psci_0_1_function_ids;
62 
63 struct psci_0_1_function_ids get_psci_0_1_function_ids(void)
64 {
65 	return psci_0_1_function_ids;
66 }
67 
68 #define PSCI_0_2_POWER_STATE_MASK		\
69 				(PSCI_0_2_POWER_STATE_ID_MASK | \
70 				PSCI_0_2_POWER_STATE_TYPE_MASK | \
71 				PSCI_0_2_POWER_STATE_AFFL_MASK)
72 
73 #define PSCI_1_0_EXT_POWER_STATE_MASK		\
74 				(PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
75 				PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
76 
77 static u32 psci_cpu_suspend_feature;
78 static bool psci_system_reset2_supported;
79 
80 static inline bool psci_has_ext_power_state(void)
81 {
82 	return psci_cpu_suspend_feature &
83 				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
84 }
85 
86 bool psci_has_osi_support(void)
87 {
88 	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
89 }
90 
91 static inline bool psci_power_state_loses_context(u32 state)
92 {
93 	const u32 mask = psci_has_ext_power_state() ?
94 					PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
95 					PSCI_0_2_POWER_STATE_TYPE_MASK;
96 
97 	return state & mask;
98 }
99 
100 bool psci_power_state_is_valid(u32 state)
101 {
102 	const u32 valid_mask = psci_has_ext_power_state() ?
103 			       PSCI_1_0_EXT_POWER_STATE_MASK :
104 			       PSCI_0_2_POWER_STATE_MASK;
105 
106 	return !(state & ~valid_mask);
107 }
108 
109 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
110 			unsigned long arg0, unsigned long arg1,
111 			unsigned long arg2)
112 {
113 	struct arm_smccc_res res;
114 
115 	arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
116 	return res.a0;
117 }
118 
119 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
120 			unsigned long arg0, unsigned long arg1,
121 			unsigned long arg2)
122 {
123 	struct arm_smccc_res res;
124 
125 	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
126 	return res.a0;
127 }
128 
129 static int psci_to_linux_errno(int errno)
130 {
131 	switch (errno) {
132 	case PSCI_RET_SUCCESS:
133 		return 0;
134 	case PSCI_RET_NOT_SUPPORTED:
135 		return -EOPNOTSUPP;
136 	case PSCI_RET_INVALID_PARAMS:
137 	case PSCI_RET_INVALID_ADDRESS:
138 		return -EINVAL;
139 	case PSCI_RET_DENIED:
140 		return -EPERM;
141 	};
142 
143 	return -EINVAL;
144 }
145 
146 static u32 psci_0_1_get_version(void)
147 {
148 	return PSCI_VERSION(0, 1);
149 }
150 
151 static u32 psci_0_2_get_version(void)
152 {
153 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
154 }
155 
156 int psci_set_osi_mode(bool enable)
157 {
158 	unsigned long suspend_mode;
159 	int err;
160 
161 	suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
162 			PSCI_1_0_SUSPEND_MODE_PC;
163 
164 	err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
165 	return psci_to_linux_errno(err);
166 }
167 
168 static int __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
169 {
170 	int err;
171 
172 	err = invoke_psci_fn(fn, state, entry_point, 0);
173 	return psci_to_linux_errno(err);
174 }
175 
176 static int psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
177 {
178 	return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
179 				  state, entry_point);
180 }
181 
182 static int psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
183 {
184 	return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
185 				  state, entry_point);
186 }
187 
188 static int __psci_cpu_off(u32 fn, u32 state)
189 {
190 	int err;
191 
192 	err = invoke_psci_fn(fn, state, 0, 0);
193 	return psci_to_linux_errno(err);
194 }
195 
196 static int psci_0_1_cpu_off(u32 state)
197 {
198 	return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
199 }
200 
201 static int psci_0_2_cpu_off(u32 state)
202 {
203 	return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
204 }
205 
206 static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
207 {
208 	int err;
209 
210 	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
211 	return psci_to_linux_errno(err);
212 }
213 
214 static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
215 {
216 	return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
217 }
218 
219 static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
220 {
221 	return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
222 }
223 
224 static int __psci_migrate(u32 fn, unsigned long cpuid)
225 {
226 	int err;
227 
228 	err = invoke_psci_fn(fn, cpuid, 0, 0);
229 	return psci_to_linux_errno(err);
230 }
231 
232 static int psci_0_1_migrate(unsigned long cpuid)
233 {
234 	return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
235 }
236 
237 static int psci_0_2_migrate(unsigned long cpuid)
238 {
239 	return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
240 }
241 
242 static int psci_affinity_info(unsigned long target_affinity,
243 		unsigned long lowest_affinity_level)
244 {
245 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
246 			      target_affinity, lowest_affinity_level, 0);
247 }
248 
249 static int psci_migrate_info_type(void)
250 {
251 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
252 }
253 
254 static unsigned long psci_migrate_info_up_cpu(void)
255 {
256 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
257 			      0, 0, 0);
258 }
259 
260 static void set_conduit(enum arm_smccc_conduit conduit)
261 {
262 	switch (conduit) {
263 	case SMCCC_CONDUIT_HVC:
264 		invoke_psci_fn = __invoke_psci_fn_hvc;
265 		break;
266 	case SMCCC_CONDUIT_SMC:
267 		invoke_psci_fn = __invoke_psci_fn_smc;
268 		break;
269 	default:
270 		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
271 	}
272 
273 	psci_conduit = conduit;
274 }
275 
276 static int get_set_conduit_method(struct device_node *np)
277 {
278 	const char *method;
279 
280 	pr_info("probing for conduit method from DT.\n");
281 
282 	if (of_property_read_string(np, "method", &method)) {
283 		pr_warn("missing \"method\" property\n");
284 		return -ENXIO;
285 	}
286 
287 	if (!strcmp("hvc", method)) {
288 		set_conduit(SMCCC_CONDUIT_HVC);
289 	} else if (!strcmp("smc", method)) {
290 		set_conduit(SMCCC_CONDUIT_SMC);
291 	} else {
292 		pr_warn("invalid \"method\" property: %s\n", method);
293 		return -EINVAL;
294 	}
295 	return 0;
296 }
297 
298 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
299 {
300 	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
301 	    psci_system_reset2_supported) {
302 		/*
303 		 * reset_type[31] = 0 (architectural)
304 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
305 		 * cookie = 0 (ignored by the implementation)
306 		 */
307 		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
308 	} else {
309 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
310 	}
311 }
312 
313 static void psci_sys_poweroff(void)
314 {
315 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
316 }
317 
318 static int __init psci_features(u32 psci_func_id)
319 {
320 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
321 			      psci_func_id, 0, 0);
322 }
323 
324 #ifdef CONFIG_CPU_IDLE
325 static int psci_suspend_finisher(unsigned long state)
326 {
327 	u32 power_state = state;
328 	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
329 
330 	return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
331 }
332 
333 int psci_cpu_suspend_enter(u32 state)
334 {
335 	int ret;
336 
337 	if (!psci_power_state_loses_context(state))
338 		ret = psci_ops.cpu_suspend(state, 0);
339 	else
340 		ret = cpu_suspend(state, psci_suspend_finisher);
341 
342 	return ret;
343 }
344 #endif
345 
346 static int psci_system_suspend(unsigned long unused)
347 {
348 	phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
349 
350 	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
351 			      pa_cpu_resume, 0, 0);
352 }
353 
354 static int psci_system_suspend_enter(suspend_state_t state)
355 {
356 	return cpu_suspend(0, psci_system_suspend);
357 }
358 
359 static const struct platform_suspend_ops psci_suspend_ops = {
360 	.valid          = suspend_valid_only_mem,
361 	.enter          = psci_system_suspend_enter,
362 };
363 
364 static void __init psci_init_system_reset2(void)
365 {
366 	int ret;
367 
368 	ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
369 
370 	if (ret != PSCI_RET_NOT_SUPPORTED)
371 		psci_system_reset2_supported = true;
372 }
373 
374 static void __init psci_init_system_suspend(void)
375 {
376 	int ret;
377 
378 	if (!IS_ENABLED(CONFIG_SUSPEND))
379 		return;
380 
381 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
382 
383 	if (ret != PSCI_RET_NOT_SUPPORTED)
384 		suspend_set_ops(&psci_suspend_ops);
385 }
386 
387 static void __init psci_init_cpu_suspend(void)
388 {
389 	int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
390 
391 	if (feature != PSCI_RET_NOT_SUPPORTED)
392 		psci_cpu_suspend_feature = feature;
393 }
394 
395 /*
396  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
397  * return DENIED (which would be fatal).
398  */
399 static void __init psci_init_migrate(void)
400 {
401 	unsigned long cpuid;
402 	int type, cpu = -1;
403 
404 	type = psci_ops.migrate_info_type();
405 
406 	if (type == PSCI_0_2_TOS_MP) {
407 		pr_info("Trusted OS migration not required\n");
408 		return;
409 	}
410 
411 	if (type == PSCI_RET_NOT_SUPPORTED) {
412 		pr_info("MIGRATE_INFO_TYPE not supported.\n");
413 		return;
414 	}
415 
416 	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
417 	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
418 		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
419 		return;
420 	}
421 
422 	cpuid = psci_migrate_info_up_cpu();
423 	if (cpuid & ~MPIDR_HWID_BITMASK) {
424 		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
425 			cpuid);
426 		return;
427 	}
428 
429 	cpu = get_logical_index(cpuid);
430 	resident_cpu = cpu >= 0 ? cpu : -1;
431 
432 	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
433 }
434 
435 static void __init psci_init_smccc(void)
436 {
437 	u32 ver = ARM_SMCCC_VERSION_1_0;
438 	int feature;
439 
440 	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
441 
442 	if (feature != PSCI_RET_NOT_SUPPORTED) {
443 		u32 ret;
444 		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
445 		if (ret >= ARM_SMCCC_VERSION_1_1) {
446 			arm_smccc_version_init(ret, psci_conduit);
447 			ver = ret;
448 		}
449 	}
450 
451 	/*
452 	 * Conveniently, the SMCCC and PSCI versions are encoded the
453 	 * same way. No, this isn't accidental.
454 	 */
455 	pr_info("SMC Calling Convention v%d.%d\n",
456 		PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
457 
458 }
459 
460 static void __init psci_0_2_set_functions(void)
461 {
462 	pr_info("Using standard PSCI v0.2 function IDs\n");
463 
464 	psci_ops = (struct psci_operations){
465 		.get_version = psci_0_2_get_version,
466 		.cpu_suspend = psci_0_2_cpu_suspend,
467 		.cpu_off = psci_0_2_cpu_off,
468 		.cpu_on = psci_0_2_cpu_on,
469 		.migrate = psci_0_2_migrate,
470 		.affinity_info = psci_affinity_info,
471 		.migrate_info_type = psci_migrate_info_type,
472 	};
473 
474 	arm_pm_restart = psci_sys_reset;
475 
476 	pm_power_off = psci_sys_poweroff;
477 }
478 
479 /*
480  * Probe function for PSCI firmware versions >= 0.2
481  */
482 static int __init psci_probe(void)
483 {
484 	u32 ver = psci_0_2_get_version();
485 
486 	pr_info("PSCIv%d.%d detected in firmware.\n",
487 			PSCI_VERSION_MAJOR(ver),
488 			PSCI_VERSION_MINOR(ver));
489 
490 	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
491 		pr_err("Conflicting PSCI version detected.\n");
492 		return -EINVAL;
493 	}
494 
495 	psci_0_2_set_functions();
496 
497 	psci_init_migrate();
498 
499 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
500 		psci_init_smccc();
501 		psci_init_cpu_suspend();
502 		psci_init_system_suspend();
503 		psci_init_system_reset2();
504 	}
505 
506 	return 0;
507 }
508 
509 typedef int (*psci_initcall_t)(const struct device_node *);
510 
511 /*
512  * PSCI init function for PSCI versions >=0.2
513  *
514  * Probe based on PSCI PSCI_VERSION function
515  */
516 static int __init psci_0_2_init(struct device_node *np)
517 {
518 	int err;
519 
520 	err = get_set_conduit_method(np);
521 	if (err)
522 		return err;
523 
524 	/*
525 	 * Starting with v0.2, the PSCI specification introduced a call
526 	 * (PSCI_VERSION) that allows probing the firmware version, so
527 	 * that PSCI function IDs and version specific initialization
528 	 * can be carried out according to the specific version reported
529 	 * by firmware
530 	 */
531 	return psci_probe();
532 }
533 
534 /*
535  * PSCI < v0.2 get PSCI Function IDs via DT.
536  */
537 static int __init psci_0_1_init(struct device_node *np)
538 {
539 	u32 id;
540 	int err;
541 
542 	err = get_set_conduit_method(np);
543 	if (err)
544 		return err;
545 
546 	pr_info("Using PSCI v0.1 Function IDs from DT\n");
547 
548 	psci_ops.get_version = psci_0_1_get_version;
549 
550 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
551 		psci_0_1_function_ids.cpu_suspend = id;
552 		psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
553 	}
554 
555 	if (!of_property_read_u32(np, "cpu_off", &id)) {
556 		psci_0_1_function_ids.cpu_off = id;
557 		psci_ops.cpu_off = psci_0_1_cpu_off;
558 	}
559 
560 	if (!of_property_read_u32(np, "cpu_on", &id)) {
561 		psci_0_1_function_ids.cpu_on = id;
562 		psci_ops.cpu_on = psci_0_1_cpu_on;
563 	}
564 
565 	if (!of_property_read_u32(np, "migrate", &id)) {
566 		psci_0_1_function_ids.migrate = id;
567 		psci_ops.migrate = psci_0_1_migrate;
568 	}
569 
570 	return 0;
571 }
572 
573 static int __init psci_1_0_init(struct device_node *np)
574 {
575 	int err;
576 
577 	err = psci_0_2_init(np);
578 	if (err)
579 		return err;
580 
581 	if (psci_has_osi_support()) {
582 		pr_info("OSI mode supported.\n");
583 
584 		/* Default to PC mode. */
585 		psci_set_osi_mode(false);
586 	}
587 
588 	return 0;
589 }
590 
591 static const struct of_device_id psci_of_match[] __initconst = {
592 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
593 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
594 	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
595 	{},
596 };
597 
598 int __init psci_dt_init(void)
599 {
600 	struct device_node *np;
601 	const struct of_device_id *matched_np;
602 	psci_initcall_t init_fn;
603 	int ret;
604 
605 	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
606 
607 	if (!np || !of_device_is_available(np))
608 		return -ENODEV;
609 
610 	init_fn = (psci_initcall_t)matched_np->data;
611 	ret = init_fn(np);
612 
613 	of_node_put(np);
614 	return ret;
615 }
616 
617 #ifdef CONFIG_ACPI
618 /*
619  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
620  * explicitly clarified in SBBR
621  */
622 int __init psci_acpi_init(void)
623 {
624 	if (!acpi_psci_present()) {
625 		pr_info("is not implemented in ACPI.\n");
626 		return -EOPNOTSUPP;
627 	}
628 
629 	pr_info("probing for conduit method from ACPI.\n");
630 
631 	if (acpi_psci_use_hvc())
632 		set_conduit(SMCCC_CONDUIT_HVC);
633 	else
634 		set_conduit(SMCCC_CONDUIT_SMC);
635 
636 	return psci_probe();
637 }
638 #endif
639