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
psci_tos_resident_on(int cpu)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 enum 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
69 static 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
80 static u32 psci_cpu_suspend_feature;
81 static bool psci_system_reset2_supported;
82
psci_has_ext_power_state(void)83 static 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
psci_has_osi_support(void)89 bool psci_has_osi_support(void)
90 {
91 return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
92 }
93
psci_power_state_loses_context(u32 state)94 static 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
psci_power_state_is_valid(u32 state)103 bool 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
__invoke_psci_fn_hvc(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)112 static 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
__invoke_psci_fn_smc(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)122 static 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
psci_to_linux_errno(int errno)132 static 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
psci_get_version(void)149 static u32 psci_get_version(void)
150 {
151 return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
152 }
153
psci_set_osi_mode(bool enable)154 int 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
psci_cpu_suspend(u32 state,unsigned long entry_point)166 static 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
psci_cpu_off(u32 state)176 static 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
psci_cpu_on(unsigned long cpuid,unsigned long entry_point)186 static 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
psci_migrate(unsigned long cpuid)196 static 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
psci_affinity_info(unsigned long target_affinity,unsigned long lowest_affinity_level)206 static 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
psci_migrate_info_type(void)213 static int psci_migrate_info_type(void)
214 {
215 return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
216 }
217
psci_migrate_info_up_cpu(void)218 static 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
set_conduit(enum arm_smccc_conduit conduit)224 static 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
get_set_conduit_method(struct device_node * np)240 static 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
psci_sys_reset(enum reboot_mode reboot_mode,const char * cmd)262 static 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
psci_sys_poweroff(void)277 static void psci_sys_poweroff(void)
278 {
279 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
280 }
281
psci_features(u32 psci_func_id)282 static 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
psci_suspend_finisher(unsigned long state)289 static int psci_suspend_finisher(unsigned long state)
290 {
291 u32 power_state = state;
292
293 return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume));
294 }
295
psci_cpu_suspend_enter(u32 state)296 int psci_cpu_suspend_enter(u32 state)
297 {
298 int ret;
299
300 if (!psci_power_state_loses_context(state))
301 ret = psci_ops.cpu_suspend(state, 0);
302 else
303 ret = cpu_suspend(state, psci_suspend_finisher);
304
305 return ret;
306 }
307 #endif
308
psci_system_suspend(unsigned long unused)309 static int psci_system_suspend(unsigned long unused)
310 {
311 return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
312 __pa_symbol(cpu_resume), 0, 0);
313 }
314
psci_system_suspend_enter(suspend_state_t state)315 static int psci_system_suspend_enter(suspend_state_t state)
316 {
317 return cpu_suspend(0, psci_system_suspend);
318 }
319
320 static const struct platform_suspend_ops psci_suspend_ops = {
321 .valid = suspend_valid_only_mem,
322 .enter = psci_system_suspend_enter,
323 };
324
psci_init_system_reset2(void)325 static void __init psci_init_system_reset2(void)
326 {
327 int ret;
328
329 ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
330
331 if (ret != PSCI_RET_NOT_SUPPORTED)
332 psci_system_reset2_supported = true;
333 }
334
psci_init_system_suspend(void)335 static void __init psci_init_system_suspend(void)
336 {
337 int ret;
338
339 if (!IS_ENABLED(CONFIG_SUSPEND))
340 return;
341
342 ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
343
344 if (ret != PSCI_RET_NOT_SUPPORTED)
345 suspend_set_ops(&psci_suspend_ops);
346 }
347
psci_init_cpu_suspend(void)348 static void __init psci_init_cpu_suspend(void)
349 {
350 int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
351
352 if (feature != PSCI_RET_NOT_SUPPORTED)
353 psci_cpu_suspend_feature = feature;
354 }
355
356 /*
357 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
358 * return DENIED (which would be fatal).
359 */
psci_init_migrate(void)360 static void __init psci_init_migrate(void)
361 {
362 unsigned long cpuid;
363 int type, cpu = -1;
364
365 type = psci_ops.migrate_info_type();
366
367 if (type == PSCI_0_2_TOS_MP) {
368 pr_info("Trusted OS migration not required\n");
369 return;
370 }
371
372 if (type == PSCI_RET_NOT_SUPPORTED) {
373 pr_info("MIGRATE_INFO_TYPE not supported.\n");
374 return;
375 }
376
377 if (type != PSCI_0_2_TOS_UP_MIGRATE &&
378 type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
379 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
380 return;
381 }
382
383 cpuid = psci_migrate_info_up_cpu();
384 if (cpuid & ~MPIDR_HWID_BITMASK) {
385 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
386 cpuid);
387 return;
388 }
389
390 cpu = get_logical_index(cpuid);
391 resident_cpu = cpu >= 0 ? cpu : -1;
392
393 pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
394 }
395
psci_init_smccc(void)396 static void __init psci_init_smccc(void)
397 {
398 u32 ver = ARM_SMCCC_VERSION_1_0;
399 int feature;
400
401 feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
402
403 if (feature != PSCI_RET_NOT_SUPPORTED) {
404 u32 ret;
405 ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
406 if (ret >= ARM_SMCCC_VERSION_1_1) {
407 arm_smccc_version_init(ret, psci_conduit);
408 ver = ret;
409 }
410 }
411
412 /*
413 * Conveniently, the SMCCC and PSCI versions are encoded the
414 * same way. No, this isn't accidental.
415 */
416 pr_info("SMC Calling Convention v%d.%d\n",
417 PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
418
419 }
420
psci_0_2_set_functions(void)421 static void __init psci_0_2_set_functions(void)
422 {
423 pr_info("Using standard PSCI v0.2 function IDs\n");
424 psci_ops.get_version = psci_get_version;
425
426 psci_function_id[PSCI_FN_CPU_SUSPEND] =
427 PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
428 psci_ops.cpu_suspend = psci_cpu_suspend;
429
430 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
431 psci_ops.cpu_off = psci_cpu_off;
432
433 psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
434 psci_ops.cpu_on = psci_cpu_on;
435
436 psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
437 psci_ops.migrate = psci_migrate;
438
439 psci_ops.affinity_info = psci_affinity_info;
440
441 psci_ops.migrate_info_type = psci_migrate_info_type;
442
443 arm_pm_restart = psci_sys_reset;
444
445 pm_power_off = psci_sys_poweroff;
446 }
447
448 /*
449 * Probe function for PSCI firmware versions >= 0.2
450 */
psci_probe(void)451 static int __init psci_probe(void)
452 {
453 u32 ver = psci_get_version();
454
455 pr_info("PSCIv%d.%d detected in firmware.\n",
456 PSCI_VERSION_MAJOR(ver),
457 PSCI_VERSION_MINOR(ver));
458
459 if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
460 pr_err("Conflicting PSCI version detected.\n");
461 return -EINVAL;
462 }
463
464 psci_0_2_set_functions();
465
466 psci_init_migrate();
467
468 if (PSCI_VERSION_MAJOR(ver) >= 1) {
469 psci_init_smccc();
470 psci_init_cpu_suspend();
471 psci_init_system_suspend();
472 psci_init_system_reset2();
473 }
474
475 return 0;
476 }
477
478 typedef int (*psci_initcall_t)(const struct device_node *);
479
480 /*
481 * PSCI init function for PSCI versions >=0.2
482 *
483 * Probe based on PSCI PSCI_VERSION function
484 */
psci_0_2_init(struct device_node * np)485 static int __init psci_0_2_init(struct device_node *np)
486 {
487 int err;
488
489 err = get_set_conduit_method(np);
490 if (err)
491 return err;
492
493 /*
494 * Starting with v0.2, the PSCI specification introduced a call
495 * (PSCI_VERSION) that allows probing the firmware version, so
496 * that PSCI function IDs and version specific initialization
497 * can be carried out according to the specific version reported
498 * by firmware
499 */
500 return psci_probe();
501 }
502
503 /*
504 * PSCI < v0.2 get PSCI Function IDs via DT.
505 */
psci_0_1_init(struct device_node * np)506 static int __init psci_0_1_init(struct device_node *np)
507 {
508 u32 id;
509 int err;
510
511 err = get_set_conduit_method(np);
512 if (err)
513 return err;
514
515 pr_info("Using PSCI v0.1 Function IDs from DT\n");
516
517 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
518 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
519 psci_ops.cpu_suspend = psci_cpu_suspend;
520 }
521
522 if (!of_property_read_u32(np, "cpu_off", &id)) {
523 psci_function_id[PSCI_FN_CPU_OFF] = id;
524 psci_ops.cpu_off = psci_cpu_off;
525 }
526
527 if (!of_property_read_u32(np, "cpu_on", &id)) {
528 psci_function_id[PSCI_FN_CPU_ON] = id;
529 psci_ops.cpu_on = psci_cpu_on;
530 }
531
532 if (!of_property_read_u32(np, "migrate", &id)) {
533 psci_function_id[PSCI_FN_MIGRATE] = id;
534 psci_ops.migrate = psci_migrate;
535 }
536
537 return 0;
538 }
539
psci_1_0_init(struct device_node * np)540 static int __init psci_1_0_init(struct device_node *np)
541 {
542 int err;
543
544 err = psci_0_2_init(np);
545 if (err)
546 return err;
547
548 if (psci_has_osi_support()) {
549 pr_info("OSI mode supported.\n");
550
551 /* Default to PC mode. */
552 psci_set_osi_mode(false);
553 }
554
555 return 0;
556 }
557
558 static const struct of_device_id psci_of_match[] __initconst = {
559 { .compatible = "arm,psci", .data = psci_0_1_init},
560 { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
561 { .compatible = "arm,psci-1.0", .data = psci_1_0_init},
562 {},
563 };
564
psci_dt_init(void)565 int __init psci_dt_init(void)
566 {
567 struct device_node *np;
568 const struct of_device_id *matched_np;
569 psci_initcall_t init_fn;
570 int ret;
571
572 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
573
574 if (!np || !of_device_is_available(np))
575 return -ENODEV;
576
577 init_fn = (psci_initcall_t)matched_np->data;
578 ret = init_fn(np);
579
580 of_node_put(np);
581 return ret;
582 }
583
584 #ifdef CONFIG_ACPI
585 /*
586 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
587 * explicitly clarified in SBBR
588 */
psci_acpi_init(void)589 int __init psci_acpi_init(void)
590 {
591 if (!acpi_psci_present()) {
592 pr_info("is not implemented in ACPI.\n");
593 return -EOPNOTSUPP;
594 }
595
596 pr_info("probing for conduit method from ACPI.\n");
597
598 if (acpi_psci_use_hvc())
599 set_conduit(SMCCC_CONDUIT_HVC);
600 else
601 set_conduit(SMCCC_CONDUIT_SMC);
602
603 return psci_probe();
604 }
605 #endif
606
