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

source code of linux/drivers/firmware/psci/psci.c