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