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) 2013 ARM Limited
12 *
13 * Author: Will Deacon <will.deacon@arm.com>
14 */
15
16 #define pr_fmt(fmt) "psci: " fmt
17
18 #include <linux/acpi.h>
19 #include <linux/init.h>
20 #include <linux/of.h>
21 #include <linux/smp.h>
22 #include <linux/reboot.h>
23 #include <linux/pm.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <uapi/linux/psci.h>
27
28 #include <asm/acpi.h>
29 #include <asm/compiler.h>
30 #include <asm/cpu_ops.h>
31 #include <asm/errno.h>
32 #include <asm/psci.h>
33 #include <asm/smp_plat.h>
34 #include <asm/suspend.h>
35 #include <asm/system_misc.h>
36
37 #define PSCI_POWER_STATE_TYPE_STANDBY 0
38 #define PSCI_POWER_STATE_TYPE_POWER_DOWN 1
39
40 struct psci_power_state {
41 u16 id;
42 u8 type;
43 u8 affinity_level;
44 };
45
46 struct psci_operations {
47 int (*cpu_suspend)(struct psci_power_state state,
48 unsigned long entry_point);
49 int (*cpu_off)(struct psci_power_state state);
50 int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
51 int (*migrate)(unsigned long cpuid);
52 int (*affinity_info)(unsigned long target_affinity,
53 unsigned long lowest_affinity_level);
54 int (*migrate_info_type)(void);
55 };
56
57 static struct psci_operations psci_ops;
58
59 static int (*invoke_psci_fn)(u64, u64, u64, u64);
60 typedef int (*psci_initcall_t)(const struct device_node *);
61
62 asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64);
63 asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64);
64
65 enum psci_function {
66 PSCI_FN_CPU_SUSPEND,
67 PSCI_FN_CPU_ON,
68 PSCI_FN_CPU_OFF,
69 PSCI_FN_MIGRATE,
70 PSCI_FN_AFFINITY_INFO,
71 PSCI_FN_MIGRATE_INFO_TYPE,
72 PSCI_FN_MAX,
73 };
74
75 static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
76
77 static u32 psci_function_id[PSCI_FN_MAX];
78
psci_to_linux_errno(int errno)79 static int psci_to_linux_errno(int errno)
80 {
81 switch (errno) {
82 case PSCI_RET_SUCCESS:
83 return 0;
84 case PSCI_RET_NOT_SUPPORTED:
85 return -EOPNOTSUPP;
86 case PSCI_RET_INVALID_PARAMS:
87 return -EINVAL;
88 case PSCI_RET_DENIED:
89 return -EPERM;
90 };
91
92 return -EINVAL;
93 }
94
psci_power_state_pack(struct psci_power_state state)95 static u32 psci_power_state_pack(struct psci_power_state state)
96 {
97 return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
98 & PSCI_0_2_POWER_STATE_ID_MASK) |
99 ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
100 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
101 ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
102 & PSCI_0_2_POWER_STATE_AFFL_MASK);
103 }
104
psci_power_state_unpack(u32 power_state,struct psci_power_state * state)105 static void psci_power_state_unpack(u32 power_state,
106 struct psci_power_state *state)
107 {
108 state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
109 PSCI_0_2_POWER_STATE_ID_SHIFT;
110 state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
111 PSCI_0_2_POWER_STATE_TYPE_SHIFT;
112 state->affinity_level =
113 (power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
114 PSCI_0_2_POWER_STATE_AFFL_SHIFT;
115 }
116
psci_get_version(void)117 static int psci_get_version(void)
118 {
119 int err;
120
121 err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
122 return err;
123 }
124
psci_cpu_suspend(struct psci_power_state state,unsigned long entry_point)125 static int psci_cpu_suspend(struct psci_power_state state,
126 unsigned long entry_point)
127 {
128 int err;
129 u32 fn, power_state;
130
131 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
132 power_state = psci_power_state_pack(state);
133 err = invoke_psci_fn(fn, power_state, entry_point, 0);
134 return psci_to_linux_errno(err);
135 }
136
psci_cpu_off(struct psci_power_state state)137 static int psci_cpu_off(struct psci_power_state state)
138 {
139 int err;
140 u32 fn, power_state;
141
142 fn = psci_function_id[PSCI_FN_CPU_OFF];
143 power_state = psci_power_state_pack(state);
144 err = invoke_psci_fn(fn, power_state, 0, 0);
145 return psci_to_linux_errno(err);
146 }
147
psci_cpu_on(unsigned long cpuid,unsigned long entry_point)148 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
149 {
150 int err;
151 u32 fn;
152
153 fn = psci_function_id[PSCI_FN_CPU_ON];
154 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
155 return psci_to_linux_errno(err);
156 }
157
psci_migrate(unsigned long cpuid)158 static int psci_migrate(unsigned long cpuid)
159 {
160 int err;
161 u32 fn;
162
163 fn = psci_function_id[PSCI_FN_MIGRATE];
164 err = invoke_psci_fn(fn, cpuid, 0, 0);
165 return psci_to_linux_errno(err);
166 }
167
psci_affinity_info(unsigned long target_affinity,unsigned long lowest_affinity_level)168 static int psci_affinity_info(unsigned long target_affinity,
169 unsigned long lowest_affinity_level)
170 {
171 int err;
172 u32 fn;
173
174 fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
175 err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
176 return err;
177 }
178
psci_migrate_info_type(void)179 static int psci_migrate_info_type(void)
180 {
181 int err;
182 u32 fn;
183
184 fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
185 err = invoke_psci_fn(fn, 0, 0, 0);
186 return err;
187 }
188
cpu_psci_cpu_init_idle(struct device_node * cpu_node,unsigned int cpu)189 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
190 unsigned int cpu)
191 {
192 int i, ret, count = 0;
193 struct psci_power_state *psci_states;
194 struct device_node *state_node;
195
196 /*
197 * If the PSCI cpu_suspend function hook has not been initialized
198 * idle states must not be enabled, so bail out
199 */
200 if (!psci_ops.cpu_suspend)
201 return -EOPNOTSUPP;
202
203 /* Count idle states */
204 while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
205 count))) {
206 count++;
207 of_node_put(state_node);
208 }
209
210 if (!count)
211 return -ENODEV;
212
213 psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
214 if (!psci_states)
215 return -ENOMEM;
216
217 for (i = 0; i < count; i++) {
218 u32 psci_power_state;
219
220 state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
221
222 ret = of_property_read_u32(state_node,
223 "arm,psci-suspend-param",
224 &psci_power_state);
225 if (ret) {
226 pr_warn(" * %s missing arm,psci-suspend-param property\n",
227 state_node->full_name);
228 of_node_put(state_node);
229 goto free_mem;
230 }
231
232 of_node_put(state_node);
233 pr_debug("psci-power-state %#x index %d\n", psci_power_state,
234 i);
235 psci_power_state_unpack(psci_power_state, &psci_states[i]);
236 }
237 /* Idle states parsed correctly, initialize per-cpu pointer */
238 per_cpu(psci_power_state, cpu) = psci_states;
239 return 0;
240
241 free_mem:
242 kfree(psci_states);
243 return ret;
244 }
245
get_set_conduit_method(struct device_node * np)246 static int get_set_conduit_method(struct device_node *np)
247 {
248 const char *method;
249
250 pr_info("probing for conduit method from DT.\n");
251
252 if (of_property_read_string(np, "method", &method)) {
253 pr_warn("missing \"method\" property\n");
254 return -ENXIO;
255 }
256
257 if (!strcmp("hvc", method)) {
258 invoke_psci_fn = __invoke_psci_fn_hvc;
259 } else if (!strcmp("smc", method)) {
260 invoke_psci_fn = __invoke_psci_fn_smc;
261 } else {
262 pr_warn("invalid \"method\" property: %s\n", method);
263 return -EINVAL;
264 }
265 return 0;
266 }
267
psci_sys_reset(enum reboot_mode reboot_mode,const char * cmd)268 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
269 {
270 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
271 }
272
psci_sys_poweroff(void)273 static void psci_sys_poweroff(void)
274 {
275 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
276 }
277
psci_0_2_set_functions(void)278 static void __init psci_0_2_set_functions(void)
279 {
280 pr_info("Using standard PSCI v0.2 function IDs\n");
281 psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
282 psci_ops.cpu_suspend = psci_cpu_suspend;
283
284 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
285 psci_ops.cpu_off = psci_cpu_off;
286
287 psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
288 psci_ops.cpu_on = psci_cpu_on;
289
290 psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
291 psci_ops.migrate = psci_migrate;
292
293 psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
294 psci_ops.affinity_info = psci_affinity_info;
295
296 psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
297 PSCI_0_2_FN_MIGRATE_INFO_TYPE;
298 psci_ops.migrate_info_type = psci_migrate_info_type;
299
300 arm_pm_restart = psci_sys_reset;
301
302 pm_power_off = psci_sys_poweroff;
303 }
304
305 /*
306 * Probe function for PSCI firmware versions >= 0.2
307 */
psci_probe(void)308 static int __init psci_probe(void)
309 {
310 int ver = psci_get_version();
311
312 if (ver == PSCI_RET_NOT_SUPPORTED) {
313 /*
314 * PSCI versions >=0.2 mandates implementation of
315 * PSCI_VERSION.
316 */
317 pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
318 return -EOPNOTSUPP;
319 } else {
320 pr_info("PSCIv%d.%d detected in firmware.\n",
321 PSCI_VERSION_MAJOR(ver),
322 PSCI_VERSION_MINOR(ver));
323
324 if (PSCI_VERSION_MAJOR(ver) == 0 &&
325 PSCI_VERSION_MINOR(ver) < 2) {
326 pr_err("Conflicting PSCI version detected.\n");
327 return -EINVAL;
328 }
329 }
330
331 psci_0_2_set_functions();
332
333 return 0;
334 }
335
336 /*
337 * PSCI init function for PSCI versions >=0.2
338 *
339 * Probe based on PSCI PSCI_VERSION function
340 */
psci_0_2_init(struct device_node * np)341 static int __init psci_0_2_init(struct device_node *np)
342 {
343 int err;
344
345 err = get_set_conduit_method(np);
346
347 if (err)
348 goto out_put_node;
349 /*
350 * Starting with v0.2, the PSCI specification introduced a call
351 * (PSCI_VERSION) that allows probing the firmware version, so
352 * that PSCI function IDs and version specific initialization
353 * can be carried out according to the specific version reported
354 * by firmware
355 */
356 err = psci_probe();
357
358 out_put_node:
359 of_node_put(np);
360 return err;
361 }
362
363 /*
364 * PSCI < v0.2 get PSCI Function IDs via DT.
365 */
psci_0_1_init(struct device_node * np)366 static int __init psci_0_1_init(struct device_node *np)
367 {
368 u32 id;
369 int err;
370
371 err = get_set_conduit_method(np);
372
373 if (err)
374 goto out_put_node;
375
376 pr_info("Using PSCI v0.1 Function IDs from DT\n");
377
378 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
379 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
380 psci_ops.cpu_suspend = psci_cpu_suspend;
381 }
382
383 if (!of_property_read_u32(np, "cpu_off", &id)) {
384 psci_function_id[PSCI_FN_CPU_OFF] = id;
385 psci_ops.cpu_off = psci_cpu_off;
386 }
387
388 if (!of_property_read_u32(np, "cpu_on", &id)) {
389 psci_function_id[PSCI_FN_CPU_ON] = id;
390 psci_ops.cpu_on = psci_cpu_on;
391 }
392
393 if (!of_property_read_u32(np, "migrate", &id)) {
394 psci_function_id[PSCI_FN_MIGRATE] = id;
395 psci_ops.migrate = psci_migrate;
396 }
397
398 out_put_node:
399 of_node_put(np);
400 return err;
401 }
402
403 static const struct of_device_id psci_of_match[] __initconst = {
404 { .compatible = "arm,psci", .data = psci_0_1_init},
405 { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
406 {},
407 };
408
psci_dt_init(void)409 int __init psci_dt_init(void)
410 {
411 struct device_node *np;
412 const struct of_device_id *matched_np;
413 psci_initcall_t init_fn;
414
415 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
416
417 if (!np)
418 return -ENODEV;
419
420 init_fn = (psci_initcall_t)matched_np->data;
421 return init_fn(np);
422 }
423
424 /*
425 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
426 * explicitly clarified in SBBR
427 */
psci_acpi_init(void)428 int __init psci_acpi_init(void)
429 {
430 if (!acpi_psci_present()) {
431 pr_info("is not implemented in ACPI.\n");
432 return -EOPNOTSUPP;
433 }
434
435 pr_info("probing for conduit method from ACPI.\n");
436
437 if (acpi_psci_use_hvc())
438 invoke_psci_fn = __invoke_psci_fn_hvc;
439 else
440 invoke_psci_fn = __invoke_psci_fn_smc;
441
442 return psci_probe();
443 }
444
445 #ifdef CONFIG_SMP
446
cpu_psci_cpu_init(struct device_node * dn,unsigned int cpu)447 static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
448 {
449 return 0;
450 }
451
cpu_psci_cpu_prepare(unsigned int cpu)452 static int __init cpu_psci_cpu_prepare(unsigned int cpu)
453 {
454 if (!psci_ops.cpu_on) {
455 pr_err("no cpu_on method, not booting CPU%d\n", cpu);
456 return -ENODEV;
457 }
458
459 return 0;
460 }
461
cpu_psci_cpu_boot(unsigned int cpu)462 static int cpu_psci_cpu_boot(unsigned int cpu)
463 {
464 int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
465 if (err)
466 pr_err("failed to boot CPU%d (%d)\n", cpu, err);
467
468 return err;
469 }
470
471 #ifdef CONFIG_HOTPLUG_CPU
cpu_psci_cpu_disable(unsigned int cpu)472 static int cpu_psci_cpu_disable(unsigned int cpu)
473 {
474 /* Fail early if we don't have CPU_OFF support */
475 if (!psci_ops.cpu_off)
476 return -EOPNOTSUPP;
477 return 0;
478 }
479
cpu_psci_cpu_die(unsigned int cpu)480 static void cpu_psci_cpu_die(unsigned int cpu)
481 {
482 int ret;
483 /*
484 * There are no known implementations of PSCI actually using the
485 * power state field, pass a sensible default for now.
486 */
487 struct psci_power_state state = {
488 .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
489 };
490
491 ret = psci_ops.cpu_off(state);
492
493 pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
494 }
495
cpu_psci_cpu_kill(unsigned int cpu)496 static int cpu_psci_cpu_kill(unsigned int cpu)
497 {
498 int err, i;
499
500 if (!psci_ops.affinity_info)
501 return 1;
502 /*
503 * cpu_kill could race with cpu_die and we can
504 * potentially end up declaring this cpu undead
505 * while it is dying. So, try again a few times.
506 */
507
508 for (i = 0; i < 10; i++) {
509 err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
510 if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
511 pr_info("CPU%d killed.\n", cpu);
512 return 1;
513 }
514
515 msleep(10);
516 pr_info("Retrying again to check for CPU kill\n");
517 }
518
519 pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
520 cpu, err);
521 /* Make op_cpu_kill() fail. */
522 return 0;
523 }
524 #endif
525 #endif
526
psci_suspend_finisher(unsigned long index)527 static int psci_suspend_finisher(unsigned long index)
528 {
529 struct psci_power_state *state = __this_cpu_read(psci_power_state);
530
531 return psci_ops.cpu_suspend(state[index - 1],
532 virt_to_phys(cpu_resume));
533 }
534
cpu_psci_cpu_suspend(unsigned long index)535 static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
536 {
537 int ret;
538 struct psci_power_state *state = __this_cpu_read(psci_power_state);
539 /*
540 * idle state index 0 corresponds to wfi, should never be called
541 * from the cpu_suspend operations
542 */
543 if (WARN_ON_ONCE(!index))
544 return -EINVAL;
545
546 if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
547 ret = psci_ops.cpu_suspend(state[index - 1], 0);
548 else
549 ret = cpu_suspend(index, psci_suspend_finisher);
550
551 return ret;
552 }
553
554 const struct cpu_operations cpu_psci_ops = {
555 .name = "psci",
556 #ifdef CONFIG_CPU_IDLE
557 .cpu_init_idle = cpu_psci_cpu_init_idle,
558 .cpu_suspend = cpu_psci_cpu_suspend,
559 #endif
560 #ifdef CONFIG_SMP
561 .cpu_init = cpu_psci_cpu_init,
562 .cpu_prepare = cpu_psci_cpu_prepare,
563 .cpu_boot = cpu_psci_cpu_boot,
564 #ifdef CONFIG_HOTPLUG_CPU
565 .cpu_disable = cpu_psci_cpu_disable,
566 .cpu_die = cpu_psci_cpu_die,
567 .cpu_kill = cpu_psci_cpu_kill,
568 #endif
569 #endif
570 };
571
572