arch/arm64/kernel/psci.c

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