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