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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2015 ARM Limited
12 */
13
14#define pr_fmt(fmt) "psci: " fmt
15
16#include <linux/acpi.h>
17#include <linux/arm-smccc.h>
18#include <linux/cpuidle.h>
19#include <linux/errno.h>
20#include <linux/linkage.h>
21#include <linux/of.h>
22#include <linux/pm.h>
23#include <linux/printk.h>
24#include <linux/psci.h>
25#include <linux/reboot.h>
26#include <linux/slab.h>
27#include <linux/suspend.h>
28
29#include <uapi/linux/psci.h>
30
31#include <asm/cpuidle.h>
32#include <asm/cputype.h>
33#include <asm/system_misc.h>
34#include <asm/smp_plat.h>
35#include <asm/suspend.h>
36
37/*
38 * While a 64-bit OS can make calls with SMC32 calling conventions, for some
39 * calls it is necessary to use SMC64 to pass or return 64-bit values.
40 * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
41 * (native-width) function ID.
42 */
43#ifdef CONFIG_64BIT
44#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN64_##name
45#else
46#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN_##name
47#endif
48
49/*
50 * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
51 * calls to its resident CPU, so we must avoid issuing those. We never migrate
52 * a Trusted OS even if it claims to be capable of migration -- doing so will
53 * require cooperation with a Trusted OS driver.
54 */
55static int resident_cpu = -1;
56
57bool psci_tos_resident_on(int cpu)
58{
59 return cpu == resident_cpu;
60}
61
62struct psci_operations psci_ops;
63
64typedef unsigned long (psci_fn)(unsigned long, unsigned long,
65 unsigned long, unsigned long);
66static psci_fn *invoke_psci_fn;
67
68enum psci_function {
69 PSCI_FN_CPU_SUSPEND,
70 PSCI_FN_CPU_ON,
71 PSCI_FN_CPU_OFF,
72 PSCI_FN_MIGRATE,
73 PSCI_FN_MAX,
74};
75
76static u32 psci_function_id[PSCI_FN_MAX];
77
78#define PSCI_0_2_POWER_STATE_MASK \
79 (PSCI_0_2_POWER_STATE_ID_MASK | \
80 PSCI_0_2_POWER_STATE_TYPE_MASK | \
81 PSCI_0_2_POWER_STATE_AFFL_MASK)
82
83#define PSCI_1_0_EXT_POWER_STATE_MASK \
84 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
85 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
86
87static u32 psci_cpu_suspend_feature;
88
89static inline bool psci_has_ext_power_state(void)
90{
91 return psci_cpu_suspend_feature &
92 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
93}
94
95static inline bool psci_power_state_loses_context(u32 state)
96{
97 const u32 mask = psci_has_ext_power_state() ?
98 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
99 PSCI_0_2_POWER_STATE_TYPE_MASK;
100
101 return state & mask;
102}
103
104static inline bool psci_power_state_is_valid(u32 state)
105{
106 const u32 valid_mask = psci_has_ext_power_state() ?
107 PSCI_1_0_EXT_POWER_STATE_MASK :
108 PSCI_0_2_POWER_STATE_MASK;
109
110 return !(state & ~valid_mask);
111}
112
113static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
114 unsigned long arg0, unsigned long arg1,
115 unsigned long arg2)
116{
117 struct arm_smccc_res res;
118
119 arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
120 return res.a0;
121}
122
123static unsigned long __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 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_get_version(void)
151{
152 return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
153}
154
155static int psci_cpu_suspend(u32 state, unsigned long entry_point)
156{
157 int err;
158 u32 fn;
159
160 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
161 err = invoke_psci_fn(fn, state, entry_point, 0);
162 return psci_to_linux_errno(err);
163}
164
165static int psci_cpu_off(u32 state)
166{
167 int err;
168 u32 fn;
169
170 fn = psci_function_id[PSCI_FN_CPU_OFF];
171 err = invoke_psci_fn(fn, state, 0, 0);
172 return psci_to_linux_errno(err);
173}
174
175static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
176{
177 int err;
178 u32 fn;
179
180 fn = psci_function_id[PSCI_FN_CPU_ON];
181 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
182 return psci_to_linux_errno(err);
183}
184
185static int psci_migrate(unsigned long cpuid)
186{
187 int err;
188 u32 fn;
189
190 fn = psci_function_id[PSCI_FN_MIGRATE];
191 err = invoke_psci_fn(fn, cpuid, 0, 0);
192 return psci_to_linux_errno(err);
193}
194
195static int psci_affinity_info(unsigned long target_affinity,
196 unsigned long lowest_affinity_level)
197{
198 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
199 target_affinity, lowest_affinity_level, 0);
200}
201
202static int psci_migrate_info_type(void)
203{
204 return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
205}
206
207static unsigned long psci_migrate_info_up_cpu(void)
208{
209 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
210 0, 0, 0);
211}
212
213static int get_set_conduit_method(struct device_node *np)
214{
215 const char *method;
216
217 pr_info("probing for conduit method from DT.\n");
218
219 if (of_property_read_string(np, "method", &method)) {
220 pr_warn("missing \"method\" property\n");
221 return -ENXIO;
222 }
223
224 if (!strcmp("hvc", method)) {
225 invoke_psci_fn = __invoke_psci_fn_hvc;
226 } else if (!strcmp("smc", method)) {
227 invoke_psci_fn = __invoke_psci_fn_smc;
228 } else {
229 pr_warn("invalid \"method\" property: %s\n", method);
230 return -EINVAL;
231 }
232 return 0;
233}
234
235static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
236{
237 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
238}
239
240static void psci_sys_poweroff(void)
241{
242 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
243}
244
245static int __init psci_features(u32 psci_func_id)
246{
247 return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
248 psci_func_id, 0, 0);
249}
250
251#ifdef CONFIG_CPU_IDLE
252static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
253
254static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
255{
256 int i, ret, count = 0;
257 u32 *psci_states;
258 struct device_node *state_node;
259
260 /* Count idle states */
261 while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
262 count))) {
263 count++;
264 of_node_put(state_node);
265 }
266
267 if (!count)
268 return -ENODEV;
269
270 psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
271 if (!psci_states)
272 return -ENOMEM;
273
274 for (i = 0; i < count; i++) {
275 u32 state;
276
277 state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
278
279 ret = of_property_read_u32(state_node,
280 "arm,psci-suspend-param",
281 &state);
282 if (ret) {
283 pr_warn(" * %s missing arm,psci-suspend-param property\n",
284 state_node->full_name);
285 of_node_put(state_node);
286 goto free_mem;
287 }
288
289 of_node_put(state_node);
290 pr_debug("psci-power-state %#x index %d\n", state, i);
291 if (!psci_power_state_is_valid(state)) {
292 pr_warn("Invalid PSCI power state %#x\n", state);
293 ret = -EINVAL;
294 goto free_mem;
295 }
296 psci_states[i] = state;
297 }
298 /* Idle states parsed correctly, initialize per-cpu pointer */
299 per_cpu(psci_power_state, cpu) = psci_states;
300 return 0;
301
302free_mem:
303 kfree(psci_states);
304 return ret;
305}
306
307#ifdef CONFIG_ACPI
308#include <acpi/processor.h>
309
310static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
311{
312 int i, count;
313 u32 *psci_states;
314 struct acpi_lpi_state *lpi;
315 struct acpi_processor *pr = per_cpu(processors, cpu);
316
317 if (unlikely(!pr || !pr->flags.has_lpi))
318 return -EINVAL;
319
320 count = pr->power.count - 1;
321 if (count <= 0)
322 return -ENODEV;
323
324 psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
325 if (!psci_states)
326 return -ENOMEM;
327
328 for (i = 0; i < count; i++) {
329 u32 state;
330
331 lpi = &pr->power.lpi_states[i + 1];
332 /*
333 * Only bits[31:0] represent a PSCI power_state while
334 * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
335 */
336 state = lpi->address;
337 if (!psci_power_state_is_valid(state)) {
338 pr_warn("Invalid PSCI power state %#x\n", state);
339 kfree(psci_states);
340 return -EINVAL;
341 }
342 psci_states[i] = state;
343 }
344 /* Idle states parsed correctly, initialize per-cpu pointer */
345 per_cpu(psci_power_state, cpu) = psci_states;
346 return 0;
347}
348#else
349static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
350{
351 return -EINVAL;
352}
353#endif
354
355int psci_cpu_init_idle(unsigned int cpu)
356{
357 struct device_node *cpu_node;
358 int ret;
359
360 /*
361 * If the PSCI cpu_suspend function hook has not been initialized
362 * idle states must not be enabled, so bail out
363 */
364 if (!psci_ops.cpu_suspend)
365 return -EOPNOTSUPP;
366
367 if (!acpi_disabled)
368 return psci_acpi_cpu_init_idle(cpu);
369
370 cpu_node = of_get_cpu_node(cpu, NULL);
371 if (!cpu_node)
372 return -ENODEV;
373
374 ret = psci_dt_cpu_init_idle(cpu_node, cpu);
375
376 of_node_put(cpu_node);
377
378 return ret;
379}
380
381static int psci_suspend_finisher(unsigned long index)
382{
383 u32 *state = __this_cpu_read(psci_power_state);
384
385 return psci_ops.cpu_suspend(state[index - 1],
386 virt_to_phys(cpu_resume));
387}
388
389int psci_cpu_suspend_enter(unsigned long index)
390{
391 int ret;
392 u32 *state = __this_cpu_read(psci_power_state);
393 /*
394 * idle state index 0 corresponds to wfi, should never be called
395 * from the cpu_suspend operations
396 */
397 if (WARN_ON_ONCE(!index))
398 return -EINVAL;
399
400 if (!psci_power_state_loses_context(state[index - 1]))
401 ret = psci_ops.cpu_suspend(state[index - 1], 0);
402 else
403 ret = cpu_suspend(index, psci_suspend_finisher);
404
405 return ret;
406}
407
408/* ARM specific CPU idle operations */
409#ifdef CONFIG_ARM
410static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
411 .suspend = psci_cpu_suspend_enter,
412 .init = psci_dt_cpu_init_idle,
413};
414
415CPUIDLE_METHOD_OF_DECLARE(psci, "psci", &psci_cpuidle_ops);
416#endif
417#endif
418
419static int psci_system_suspend(unsigned long unused)
420{
421 return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
422 virt_to_phys(cpu_resume), 0, 0);
423}
424
425static int psci_system_suspend_enter(suspend_state_t state)
426{
427 return cpu_suspend(0, psci_system_suspend);
428}
429
430static const struct platform_suspend_ops psci_suspend_ops = {
431 .valid = suspend_valid_only_mem,
432 .enter = psci_system_suspend_enter,
433};
434
435static void __init psci_init_system_suspend(void)
436{
437 int ret;
438
439 if (!IS_ENABLED(CONFIG_SUSPEND))
440 return;
441
442 ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
443
444 if (ret != PSCI_RET_NOT_SUPPORTED)
445 suspend_set_ops(&psci_suspend_ops);
446}
447
448static void __init psci_init_cpu_suspend(void)
449{
450 int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
451
452 if (feature != PSCI_RET_NOT_SUPPORTED)
453 psci_cpu_suspend_feature = feature;
454}
455
456/*
457 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
458 * return DENIED (which would be fatal).
459 */
460static void __init psci_init_migrate(void)
461{
462 unsigned long cpuid;
463 int type, cpu = -1;
464
465 type = psci_ops.migrate_info_type();
466
467 if (type == PSCI_0_2_TOS_MP) {
468 pr_info("Trusted OS migration not required\n");
469 return;
470 }
471
472 if (type == PSCI_RET_NOT_SUPPORTED) {
473 pr_info("MIGRATE_INFO_TYPE not supported.\n");
474 return;
475 }
476
477 if (type != PSCI_0_2_TOS_UP_MIGRATE &&
478 type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
479 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
480 return;
481 }
482
483 cpuid = psci_migrate_info_up_cpu();
484 if (cpuid & ~MPIDR_HWID_BITMASK) {
485 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
486 cpuid);
487 return;
488 }
489
490 cpu = get_logical_index(cpuid);
491 resident_cpu = cpu >= 0 ? cpu : -1;
492
493 pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
494}
495
496static void __init psci_0_2_set_functions(void)
497{
498 pr_info("Using standard PSCI v0.2 function IDs\n");
499 psci_function_id[PSCI_FN_CPU_SUSPEND] =
500 PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
501 psci_ops.cpu_suspend = psci_cpu_suspend;
502
503 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
504 psci_ops.cpu_off = psci_cpu_off;
505
506 psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
507 psci_ops.cpu_on = psci_cpu_on;
508
509 psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
510 psci_ops.migrate = psci_migrate;
511
512 psci_ops.affinity_info = psci_affinity_info;
513
514 psci_ops.migrate_info_type = psci_migrate_info_type;
515
516 arm_pm_restart = psci_sys_reset;
517
518 pm_power_off = psci_sys_poweroff;
519}
520
521/*
522 * Probe function for PSCI firmware versions >= 0.2
523 */
524static int __init psci_probe(void)
525{
526 u32 ver = psci_get_version();
527
528 pr_info("PSCIv%d.%d detected in firmware.\n",
529 PSCI_VERSION_MAJOR(ver),
530 PSCI_VERSION_MINOR(ver));
531
532 if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
533 pr_err("Conflicting PSCI version detected.\n");
534 return -EINVAL;
535 }
536
537 psci_0_2_set_functions();
538
539 psci_init_migrate();
540
541 if (PSCI_VERSION_MAJOR(ver) >= 1) {
542 psci_init_cpu_suspend();
543 psci_init_system_suspend();
544 }
545
546 return 0;
547}
548
549typedef int (*psci_initcall_t)(const struct device_node *);
550
551/*
552 * PSCI init function for PSCI versions >=0.2
553 *
554 * Probe based on PSCI PSCI_VERSION function
555 */
556static int __init psci_0_2_init(struct device_node *np)
557{
558 int err;
559
560 err = get_set_conduit_method(np);
561
562 if (err)
563 goto out_put_node;
564 /*
565 * Starting with v0.2, the PSCI specification introduced a call
566 * (PSCI_VERSION) that allows probing the firmware version, so
567 * that PSCI function IDs and version specific initialization
568 * can be carried out according to the specific version reported
569 * by firmware
570 */
571 err = psci_probe();
572
573out_put_node:
574 of_node_put(np);
575 return err;
576}
577
578/*
579 * PSCI < v0.2 get PSCI Function IDs via DT.
580 */
581static int __init psci_0_1_init(struct device_node *np)
582{
583 u32 id;
584 int err;
585
586 err = get_set_conduit_method(np);
587
588 if (err)
589 goto out_put_node;
590
591 pr_info("Using PSCI v0.1 Function IDs from DT\n");
592
593 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
594 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
595 psci_ops.cpu_suspend = psci_cpu_suspend;
596 }
597
598 if (!of_property_read_u32(np, "cpu_off", &id)) {
599 psci_function_id[PSCI_FN_CPU_OFF] = id;
600 psci_ops.cpu_off = psci_cpu_off;
601 }
602
603 if (!of_property_read_u32(np, "cpu_on", &id)) {
604 psci_function_id[PSCI_FN_CPU_ON] = id;
605 psci_ops.cpu_on = psci_cpu_on;
606 }
607
608 if (!of_property_read_u32(np, "migrate", &id)) {
609 psci_function_id[PSCI_FN_MIGRATE] = id;
610 psci_ops.migrate = psci_migrate;
611 }
612
613out_put_node:
614 of_node_put(np);
615 return err;
616}
617
618static const struct of_device_id psci_of_match[] __initconst = {
619 { .compatible = "arm,psci", .data = psci_0_1_init},
620 { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
621 { .compatible = "arm,psci-1.0", .data = psci_0_2_init},
622 {},
623};
624
625int __init psci_dt_init(void)
626{
627 struct device_node *np;
628 const struct of_device_id *matched_np;
629 psci_initcall_t init_fn;
630
631 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
632
633 if (!np || !of_device_is_available(np))
634 return -ENODEV;
635
636 init_fn = (psci_initcall_t)matched_np->data;
637 return init_fn(np);
638}
639
640#ifdef CONFIG_ACPI
641/*
642 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
643 * explicitly clarified in SBBR
644 */
645int __init psci_acpi_init(void)
646{
647 if (!acpi_psci_present()) {
648 pr_info("is not implemented in ACPI.\n");
649 return -EOPNOTSUPP;
650 }
651
652 pr_info("probing for conduit method from ACPI.\n");
653
654 if (acpi_psci_use_hvc())
655 invoke_psci_fn = __invoke_psci_fn_hvc;
656 else
657 invoke_psci_fn = __invoke_psci_fn_smc;
658
659 return psci_probe();
660}
661#endif