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
psci_tos_resident_on(int cpu)50 bool psci_tos_resident_on(int cpu)
51 {
52 return cpu == resident_cpu;
53 }
54
55 struct psci_operations psci_ops = {
56 .conduit = PSCI_CONDUIT_NONE,
57 .smccc_version = SMCCC_VERSION_1_0,
58 };
59
60 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
61 unsigned long, unsigned long);
62 static psci_fn *invoke_psci_fn;
63
64 enum psci_function {
65 PSCI_FN_CPU_SUSPEND,
66 PSCI_FN_CPU_ON,
67 PSCI_FN_CPU_OFF,
68 PSCI_FN_MIGRATE,
69 PSCI_FN_MAX,
70 };
71
72 static u32 psci_function_id[PSCI_FN_MAX];
73
74 #define PSCI_0_2_POWER_STATE_MASK \
75 (PSCI_0_2_POWER_STATE_ID_MASK | \
76 PSCI_0_2_POWER_STATE_TYPE_MASK | \
77 PSCI_0_2_POWER_STATE_AFFL_MASK)
78
79 #define PSCI_1_0_EXT_POWER_STATE_MASK \
80 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
81 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
82
83 static u32 psci_cpu_suspend_feature;
84 static bool psci_system_reset2_supported;
85
psci_has_ext_power_state(void)86 static inline bool psci_has_ext_power_state(void)
87 {
88 return psci_cpu_suspend_feature &
89 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
90 }
91
psci_has_osi_support(void)92 static inline bool psci_has_osi_support(void)
93 {
94 return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
95 }
96
psci_power_state_loses_context(u32 state)97 static inline bool psci_power_state_loses_context(u32 state)
98 {
99 const u32 mask = psci_has_ext_power_state() ?
100 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
101 PSCI_0_2_POWER_STATE_TYPE_MASK;
102
103 return state & mask;
104 }
105
psci_power_state_is_valid(u32 state)106 bool psci_power_state_is_valid(u32 state)
107 {
108 const u32 valid_mask = psci_has_ext_power_state() ?
109 PSCI_1_0_EXT_POWER_STATE_MASK :
110 PSCI_0_2_POWER_STATE_MASK;
111
112 return !(state & ~valid_mask);
113 }
114
__invoke_psci_fn_hvc(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)115 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
116 unsigned long arg0, unsigned long arg1,
117 unsigned long arg2)
118 {
119 struct arm_smccc_res res;
120
121 arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
122 return res.a0;
123 }
124
__invoke_psci_fn_smc(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)125 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
126 unsigned long arg0, unsigned long arg1,
127 unsigned long arg2)
128 {
129 struct arm_smccc_res res;
130
131 arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
132 return res.a0;
133 }
134
psci_to_linux_errno(int errno)135 static int psci_to_linux_errno(int errno)
136 {
137 switch (errno) {
138 case PSCI_RET_SUCCESS:
139 return 0;
140 case PSCI_RET_NOT_SUPPORTED:
141 return -EOPNOTSUPP;
142 case PSCI_RET_INVALID_PARAMS:
143 case PSCI_RET_INVALID_ADDRESS:
144 return -EINVAL;
145 case PSCI_RET_DENIED:
146 return -EPERM;
147 };
148
149 return -EINVAL;
150 }
151
psci_get_version(void)152 static u32 psci_get_version(void)
153 {
154 return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
155 }
156
psci_cpu_suspend(u32 state,unsigned long entry_point)157 static int psci_cpu_suspend(u32 state, unsigned long entry_point)
158 {
159 int err;
160 u32 fn;
161
162 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
163 err = invoke_psci_fn(fn, state, entry_point, 0);
164 return psci_to_linux_errno(err);
165 }
166
psci_cpu_off(u32 state)167 static int psci_cpu_off(u32 state)
168 {
169 int err;
170 u32 fn;
171
172 fn = psci_function_id[PSCI_FN_CPU_OFF];
173 err = invoke_psci_fn(fn, state, 0, 0);
174 return psci_to_linux_errno(err);
175 }
176
psci_cpu_on(unsigned long cpuid,unsigned long entry_point)177 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
178 {
179 int err;
180 u32 fn;
181
182 fn = psci_function_id[PSCI_FN_CPU_ON];
183 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
184 return psci_to_linux_errno(err);
185 }
186
psci_migrate(unsigned long cpuid)187 static int psci_migrate(unsigned long cpuid)
188 {
189 int err;
190 u32 fn;
191
192 fn = psci_function_id[PSCI_FN_MIGRATE];
193 err = invoke_psci_fn(fn, cpuid, 0, 0);
194 return psci_to_linux_errno(err);
195 }
196
psci_affinity_info(unsigned long target_affinity,unsigned long lowest_affinity_level)197 static int psci_affinity_info(unsigned long target_affinity,
198 unsigned long lowest_affinity_level)
199 {
200 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
201 target_affinity, lowest_affinity_level, 0);
202 }
203
psci_migrate_info_type(void)204 static int psci_migrate_info_type(void)
205 {
206 return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
207 }
208
psci_migrate_info_up_cpu(void)209 static unsigned long psci_migrate_info_up_cpu(void)
210 {
211 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
212 0, 0, 0);
213 }
214
set_conduit(enum psci_conduit conduit)215 static void set_conduit(enum psci_conduit conduit)
216 {
217 switch (conduit) {
218 case PSCI_CONDUIT_HVC:
219 invoke_psci_fn = __invoke_psci_fn_hvc;
220 break;
221 case PSCI_CONDUIT_SMC:
222 invoke_psci_fn = __invoke_psci_fn_smc;
223 break;
224 default:
225 WARN(1, "Unexpected PSCI conduit %d\n", conduit);
226 }
227
228 psci_ops.conduit = conduit;
229 }
230
get_set_conduit_method(struct device_node * np)231 static int get_set_conduit_method(struct device_node *np)
232 {
233 const char *method;
234
235 pr_info("probing for conduit method from DT.\n");
236
237 if (of_property_read_string(np, "method", &method)) {
238 pr_warn("missing \"method\" property\n");
239 return -ENXIO;
240 }
241
242 if (!strcmp("hvc", method)) {
243 set_conduit(PSCI_CONDUIT_HVC);
244 } else if (!strcmp("smc", method)) {
245 set_conduit(PSCI_CONDUIT_SMC);
246 } else {
247 pr_warn("invalid \"method\" property: %s\n", method);
248 return -EINVAL;
249 }
250 return 0;
251 }
252
psci_sys_reset(enum reboot_mode reboot_mode,const char * cmd)253 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
254 {
255 if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
256 psci_system_reset2_supported) {
257 /*
258 * reset_type[31] = 0 (architectural)
259 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
260 * cookie = 0 (ignored by the implementation)
261 */
262 invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
263 } else {
264 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
265 }
266 }
267
psci_sys_poweroff(void)268 static void psci_sys_poweroff(void)
269 {
270 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
271 }
272
psci_features(u32 psci_func_id)273 static int __init psci_features(u32 psci_func_id)
274 {
275 return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
276 psci_func_id, 0, 0);
277 }
278
279 #ifdef CONFIG_CPU_IDLE
psci_suspend_finisher(unsigned long state)280 static int psci_suspend_finisher(unsigned long state)
281 {
282 u32 power_state = state;
283
284 return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume));
285 }
286
psci_cpu_suspend_enter(u32 state)287 int psci_cpu_suspend_enter(u32 state)
288 {
289 int ret;
290
291 if (!psci_power_state_loses_context(state))
292 ret = psci_ops.cpu_suspend(state, 0);
293 else
294 ret = cpu_suspend(state, psci_suspend_finisher);
295
296 return ret;
297 }
298 #endif
299
psci_system_suspend(unsigned long unused)300 static int psci_system_suspend(unsigned long unused)
301 {
302 return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
303 __pa_symbol(cpu_resume), 0, 0);
304 }
305
psci_system_suspend_enter(suspend_state_t state)306 static int psci_system_suspend_enter(suspend_state_t state)
307 {
308 return cpu_suspend(0, psci_system_suspend);
309 }
310
311 static const struct platform_suspend_ops psci_suspend_ops = {
312 .valid = suspend_valid_only_mem,
313 .enter = psci_system_suspend_enter,
314 };
315
psci_init_system_reset2(void)316 static void __init psci_init_system_reset2(void)
317 {
318 int ret;
319
320 ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
321
322 if (ret != PSCI_RET_NOT_SUPPORTED)
323 psci_system_reset2_supported = true;
324 }
325
psci_init_system_suspend(void)326 static void __init psci_init_system_suspend(void)
327 {
328 int ret;
329
330 if (!IS_ENABLED(CONFIG_SUSPEND))
331 return;
332
333 ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
334
335 if (ret != PSCI_RET_NOT_SUPPORTED)
336 suspend_set_ops(&psci_suspend_ops);
337 }
338
psci_init_cpu_suspend(void)339 static void __init psci_init_cpu_suspend(void)
340 {
341 int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
342
343 if (feature != PSCI_RET_NOT_SUPPORTED)
344 psci_cpu_suspend_feature = feature;
345 }
346
347 /*
348 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
349 * return DENIED (which would be fatal).
350 */
psci_init_migrate(void)351 static void __init psci_init_migrate(void)
352 {
353 unsigned long cpuid;
354 int type, cpu = -1;
355
356 type = psci_ops.migrate_info_type();
357
358 if (type == PSCI_0_2_TOS_MP) {
359 pr_info("Trusted OS migration not required\n");
360 return;
361 }
362
363 if (type == PSCI_RET_NOT_SUPPORTED) {
364 pr_info("MIGRATE_INFO_TYPE not supported.\n");
365 return;
366 }
367
368 if (type != PSCI_0_2_TOS_UP_MIGRATE &&
369 type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
370 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
371 return;
372 }
373
374 cpuid = psci_migrate_info_up_cpu();
375 if (cpuid & ~MPIDR_HWID_BITMASK) {
376 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
377 cpuid);
378 return;
379 }
380
381 cpu = get_logical_index(cpuid);
382 resident_cpu = cpu >= 0 ? cpu : -1;
383
384 pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
385 }
386
psci_init_smccc(void)387 static void __init psci_init_smccc(void)
388 {
389 u32 ver = ARM_SMCCC_VERSION_1_0;
390 int feature;
391
392 feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
393
394 if (feature != PSCI_RET_NOT_SUPPORTED) {
395 u32 ret;
396 ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
397 if (ret == ARM_SMCCC_VERSION_1_1) {
398 psci_ops.smccc_version = SMCCC_VERSION_1_1;
399 ver = ret;
400 }
401 }
402
403 /*
404 * Conveniently, the SMCCC and PSCI versions are encoded the
405 * same way. No, this isn't accidental.
406 */
407 pr_info("SMC Calling Convention v%d.%d\n",
408 PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
409
410 }
411
psci_0_2_set_functions(void)412 static void __init psci_0_2_set_functions(void)
413 {
414 pr_info("Using standard PSCI v0.2 function IDs\n");
415 psci_ops.get_version = psci_get_version;
416
417 psci_function_id[PSCI_FN_CPU_SUSPEND] =
418 PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
419 psci_ops.cpu_suspend = psci_cpu_suspend;
420
421 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
422 psci_ops.cpu_off = psci_cpu_off;
423
424 psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
425 psci_ops.cpu_on = psci_cpu_on;
426
427 psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
428 psci_ops.migrate = psci_migrate;
429
430 psci_ops.affinity_info = psci_affinity_info;
431
432 psci_ops.migrate_info_type = psci_migrate_info_type;
433
434 arm_pm_restart = psci_sys_reset;
435
436 pm_power_off = psci_sys_poweroff;
437 }
438
439 /*
440 * Probe function for PSCI firmware versions >= 0.2
441 */
psci_probe(void)442 static int __init psci_probe(void)
443 {
444 u32 ver = psci_get_version();
445
446 pr_info("PSCIv%d.%d detected in firmware.\n",
447 PSCI_VERSION_MAJOR(ver),
448 PSCI_VERSION_MINOR(ver));
449
450 if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
451 pr_err("Conflicting PSCI version detected.\n");
452 return -EINVAL;
453 }
454
455 psci_0_2_set_functions();
456
457 psci_init_migrate();
458
459 if (PSCI_VERSION_MAJOR(ver) >= 1) {
460 psci_init_smccc();
461 psci_init_cpu_suspend();
462 psci_init_system_suspend();
463 psci_init_system_reset2();
464 }
465
466 return 0;
467 }
468
469 typedef int (*psci_initcall_t)(const struct device_node *);
470
471 /*
472 * PSCI init function for PSCI versions >=0.2
473 *
474 * Probe based on PSCI PSCI_VERSION function
475 */
psci_0_2_init(struct device_node * np)476 static int __init psci_0_2_init(struct device_node *np)
477 {
478 int err;
479
480 err = get_set_conduit_method(np);
481 if (err)
482 return err;
483
484 /*
485 * Starting with v0.2, the PSCI specification introduced a call
486 * (PSCI_VERSION) that allows probing the firmware version, so
487 * that PSCI function IDs and version specific initialization
488 * can be carried out according to the specific version reported
489 * by firmware
490 */
491 return psci_probe();
492 }
493
494 /*
495 * PSCI < v0.2 get PSCI Function IDs via DT.
496 */
psci_0_1_init(struct device_node * np)497 static int __init psci_0_1_init(struct device_node *np)
498 {
499 u32 id;
500 int err;
501
502 err = get_set_conduit_method(np);
503 if (err)
504 return err;
505
506 pr_info("Using PSCI v0.1 Function IDs from DT\n");
507
508 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
509 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
510 psci_ops.cpu_suspend = psci_cpu_suspend;
511 }
512
513 if (!of_property_read_u32(np, "cpu_off", &id)) {
514 psci_function_id[PSCI_FN_CPU_OFF] = id;
515 psci_ops.cpu_off = psci_cpu_off;
516 }
517
518 if (!of_property_read_u32(np, "cpu_on", &id)) {
519 psci_function_id[PSCI_FN_CPU_ON] = id;
520 psci_ops.cpu_on = psci_cpu_on;
521 }
522
523 if (!of_property_read_u32(np, "migrate", &id)) {
524 psci_function_id[PSCI_FN_MIGRATE] = id;
525 psci_ops.migrate = psci_migrate;
526 }
527
528 return 0;
529 }
530
psci_1_0_init(struct device_node * np)531 static int __init psci_1_0_init(struct device_node *np)
532 {
533 int err;
534
535 err = psci_0_2_init(np);
536 if (err)
537 return err;
538
539 if (psci_has_osi_support())
540 pr_info("OSI mode supported.\n");
541
542 return 0;
543 }
544
545 static const struct of_device_id psci_of_match[] __initconst = {
546 { .compatible = "arm,psci", .data = psci_0_1_init},
547 { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
548 { .compatible = "arm,psci-1.0", .data = psci_1_0_init},
549 {},
550 };
551
psci_dt_init(void)552 int __init psci_dt_init(void)
553 {
554 struct device_node *np;
555 const struct of_device_id *matched_np;
556 psci_initcall_t init_fn;
557 int ret;
558
559 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
560
561 if (!np || !of_device_is_available(np))
562 return -ENODEV;
563
564 init_fn = (psci_initcall_t)matched_np->data;
565 ret = init_fn(np);
566
567 of_node_put(np);
568 return ret;
569 }
570
571 #ifdef CONFIG_ACPI
572 /*
573 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
574 * explicitly clarified in SBBR
575 */
psci_acpi_init(void)576 int __init psci_acpi_init(void)
577 {
578 if (!acpi_psci_present()) {
579 pr_info("is not implemented in ACPI.\n");
580 return -EOPNOTSUPP;
581 }
582
583 pr_info("probing for conduit method from ACPI.\n");
584
585 if (acpi_psci_use_hvc())
586 set_conduit(PSCI_CONDUIT_HVC);
587 else
588 set_conduit(PSCI_CONDUIT_SMC);
589
590 return psci_probe();
591 }
592 #endif
593
