drivers/firmware/psci/psci.c

   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  */
  48 static int resident_cpu = -1;
  49 struct psci_operations psci_ops;
  50 static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
  51
  52 bool psci_tos_resident_on(int cpu)
  53 {
  54         return cpu == resident_cpu;
  55 }
  56
  57 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
  58                                 unsigned long, unsigned long);
  59 static psci_fn *invoke_psci_fn;
  60
  61 static struct psci_0_1_function_ids psci_0_1_function_ids;
  62
  63 struct psci_0_1_function_ids get_psci_0_1_function_ids(void)
  64 {
  65         return psci_0_1_function_ids;
  66 }
  67
  68 #define PSCI_0_2_POWER_STATE_MASK               \
  69                                 (PSCI_0_2_POWER_STATE_ID_MASK | \
  70                                 PSCI_0_2_POWER_STATE_TYPE_MASK | \
  71                                 PSCI_0_2_POWER_STATE_AFFL_MASK)
  72
  73 #define PSCI_1_0_EXT_POWER_STATE_MASK           \
  74                                 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
  75                                 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
  76
  77 static u32 psci_cpu_suspend_feature;
  78 static bool psci_system_reset2_supported;
  79
  80 static inline bool psci_has_ext_power_state(void)
  81 {
  82         return psci_cpu_suspend_feature &
  83                                 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
  84 }
  85
  86 bool psci_has_osi_support(void)
  87 {
  88         return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
  89 }
  90
  91 static inline bool psci_power_state_loses_context(u32 state)
  92 {
  93         const u32 mask = psci_has_ext_power_state() ?
  94                                         PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
  95                                         PSCI_0_2_POWER_STATE_TYPE_MASK;
  96
  97         return state & mask;
  98 }
  99
 100 bool psci_power_state_is_valid(u32 state)
 101 {
 102         const u32 valid_mask = psci_has_ext_power_state() ?
 103                                PSCI_1_0_EXT_POWER_STATE_MASK :
 104                                PSCI_0_2_POWER_STATE_MASK;
 105
 106         return !(state & ~valid_mask);
 107 }
 108
 109 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
 110                         unsigned long arg0, unsigned long arg1,
 111                         unsigned long arg2)
 112 {
 113         struct arm_smccc_res res;
 114
 115         arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 116         return res.a0;
 117 }
 118
 119 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
 120                         unsigned long arg0, unsigned long arg1,
 121                         unsigned long arg2)
 122 {
 123         struct arm_smccc_res res;
 124
 125         arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 126         return res.a0;
 127 }
 128
 129 static int psci_to_linux_errno(int errno)
 130 {
 131         switch (errno) {
 132         case PSCI_RET_SUCCESS:
 133                 return 0;
 134         case PSCI_RET_NOT_SUPPORTED:
 135                 return -EOPNOTSUPP;
 136         case PSCI_RET_INVALID_PARAMS:
 137         case PSCI_RET_INVALID_ADDRESS:
 138                 return -EINVAL;
 139         case PSCI_RET_DENIED:
 140                 return -EPERM;
 141         };
 142
 143         return -EINVAL;
 144 }
 145
 146 static u32 psci_0_1_get_version(void)
 147 {
 148         return PSCI_VERSION(0, 1);
 149 }
 150
 151 static u32 psci_0_2_get_version(void)
 152 {
 153         return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 154 }
 155
 156 int psci_set_osi_mode(bool enable)
 157 {
 158         unsigned long suspend_mode;
 159         int err;
 160
 161         suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
 162                         PSCI_1_0_SUSPEND_MODE_PC;
 163
 164         err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
 165         return psci_to_linux_errno(err);
 166 }
 167
 168 static int __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
 169 {
 170         int err;
 171
 172         err = invoke_psci_fn(fn, state, entry_point, 0);
 173         return psci_to_linux_errno(err);
 174 }
 175
 176 static int psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
 177 {
 178         return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
 179                                   state, entry_point);
 180 }
 181
 182 static int psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
 183 {
 184         return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
 185                                   state, entry_point);
 186 }
 187
 188 static int __psci_cpu_off(u32 fn, u32 state)
 189 {
 190         int err;
 191
 192         err = invoke_psci_fn(fn, state, 0, 0);
 193         return psci_to_linux_errno(err);
 194 }
 195
 196 static int psci_0_1_cpu_off(u32 state)
 197 {
 198         return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
 199 }
 200
 201 static int psci_0_2_cpu_off(u32 state)
 202 {
 203         return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
 204 }
 205
 206 static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
 207 {
 208         int err;
 209
 210         err = invoke_psci_fn(fn, cpuid, entry_point, 0);
 211         return psci_to_linux_errno(err);
 212 }
 213
 214 static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
 215 {
 216         return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
 217 }
 218
 219 static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
 220 {
 221         return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
 222 }
 223
 224 static int __psci_migrate(u32 fn, unsigned long cpuid)
 225 {
 226         int err;
 227
 228         err = invoke_psci_fn(fn, cpuid, 0, 0);
 229         return psci_to_linux_errno(err);
 230 }
 231
 232 static int psci_0_1_migrate(unsigned long cpuid)
 233 {
 234         return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
 235 }
 236
 237 static int psci_0_2_migrate(unsigned long cpuid)
 238 {
 239         return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
 240 }
 241
 242 static int psci_affinity_info(unsigned long target_affinity,
 243                 unsigned long lowest_affinity_level)
 244 {
 245         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
 246                               target_affinity, lowest_affinity_level, 0);
 247 }
 248
 249 static int psci_migrate_info_type(void)
 250 {
 251         return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 252 }
 253
 254 static unsigned long psci_migrate_info_up_cpu(void)
 255 {
 256         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
 257                               0, 0, 0);
 258 }
 259
 260 static void set_conduit(enum arm_smccc_conduit conduit)
 261 {
 262         switch (conduit) {
 263         case SMCCC_CONDUIT_HVC:
 264                 invoke_psci_fn = __invoke_psci_fn_hvc;
 265                 break;
 266         case SMCCC_CONDUIT_SMC:
 267                 invoke_psci_fn = __invoke_psci_fn_smc;
 268                 break;
 269         default:
 270                 WARN(1, "Unexpected PSCI conduit %d\n", conduit);
 271         }
 272
 273         psci_conduit = conduit;
 274 }
 275
 276 static int get_set_conduit_method(struct device_node *np)
 277 {
 278         const char *method;
 279
 280         pr_info("probing for conduit method from DT.\n");
 281
 282         if (of_property_read_string(np, "method", &method)) {
 283                 pr_warn("missing \"method\" property\n");
 284                 return -ENXIO;
 285         }
 286
 287         if (!strcmp("hvc", method)) {
 288                 set_conduit(SMCCC_CONDUIT_HVC);
 289         } else if (!strcmp("smc", method)) {
 290                 set_conduit(SMCCC_CONDUIT_SMC);
 291         } else {
 292                 pr_warn("invalid \"method\" property: %s\n", method);
 293                 return -EINVAL;
 294         }
 295         return 0;
 296 }
 297
 298 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
 299 {
 300         if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
 301             psci_system_reset2_supported) {
 302                 /*
 303                  * reset_type[31] = 0 (architectural)
 304                  * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
 305                  * cookie = 0 (ignored by the implementation)
 306                  */
 307                 invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
 308         } else {
 309                 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
 310         }
 311 }
 312
 313 static void psci_sys_poweroff(void)
 314 {
 315         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
 316 }
 317
 318 static int __init psci_features(u32 psci_func_id)
 319 {
 320         return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
 321                               psci_func_id, 0, 0);
 322 }
 323
 324 #ifdef CONFIG_CPU_IDLE
 325 static int psci_suspend_finisher(unsigned long state)
 326 {
 327         u32 power_state = state;
 328
 329         return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume));
 330 }
 331
 332 int psci_cpu_suspend_enter(u32 state)
 333 {
 334         int ret;
 335
 336         if (!psci_power_state_loses_context(state))
 337                 ret = psci_ops.cpu_suspend(state, 0);
 338         else
 339                 ret = cpu_suspend(state, psci_suspend_finisher);
 340
 341         return ret;
 342 }
 343 #endif
 344
 345 static int psci_system_suspend(unsigned long unused)
 346 {
 347         return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
 348                               __pa_symbol(cpu_resume), 0, 0);
 349 }
 350
 351 static int psci_system_suspend_enter(suspend_state_t state)
 352 {
 353         return cpu_suspend(0, psci_system_suspend);
 354 }
 355
 356 static const struct platform_suspend_ops psci_suspend_ops = {
 357         .valid          = suspend_valid_only_mem,
 358         .enter          = psci_system_suspend_enter,
 359 };
 360
 361 static void __init psci_init_system_reset2(void)
 362 {
 363         int ret;
 364
 365         ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
 366
 367         if (ret != PSCI_RET_NOT_SUPPORTED)
 368                 psci_system_reset2_supported = true;
 369 }
 370
 371 static void __init psci_init_system_suspend(void)
 372 {
 373         int ret;
 374
 375         if (!IS_ENABLED(CONFIG_SUSPEND))
 376                 return;
 377
 378         ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
 379
 380         if (ret != PSCI_RET_NOT_SUPPORTED)
 381                 suspend_set_ops(&psci_suspend_ops);
 382 }
 383
 384 static void __init psci_init_cpu_suspend(void)
 385 {
 386         int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
 387
 388         if (feature != PSCI_RET_NOT_SUPPORTED)
 389                 psci_cpu_suspend_feature = feature;
 390 }
 391
 392 /*
 393  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
 394  * return DENIED (which would be fatal).
 395  */
 396 static void __init psci_init_migrate(void)
 397 {
 398         unsigned long cpuid;
 399         int type, cpu = -1;
 400
 401         type = psci_ops.migrate_info_type();
 402
 403         if (type == PSCI_0_2_TOS_MP) {
 404                 pr_info("Trusted OS migration not required\n");
 405                 return;
 406         }
 407
 408         if (type == PSCI_RET_NOT_SUPPORTED) {
 409                 pr_info("MIGRATE_INFO_TYPE not supported.\n");
 410                 return;
 411         }
 412
 413         if (type != PSCI_0_2_TOS_UP_MIGRATE &&
 414             type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
 415                 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
 416                 return;
 417         }
 418
 419         cpuid = psci_migrate_info_up_cpu();
 420         if (cpuid & ~MPIDR_HWID_BITMASK) {
 421                 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
 422                         cpuid);
 423                 return;
 424         }
 425
 426         cpu = get_logical_index(cpuid);
 427         resident_cpu = cpu >= 0 ? cpu : -1;
 428
 429         pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
 430 }
 431
 432 static void __init psci_init_smccc(void)
 433 {
 434         u32 ver = ARM_SMCCC_VERSION_1_0;
 435         int feature;
 436
 437         feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
 438
 439         if (feature != PSCI_RET_NOT_SUPPORTED) {
 440                 u32 ret;
 441                 ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
 442                 if (ret >= ARM_SMCCC_VERSION_1_1) {
 443                         arm_smccc_version_init(ret, psci_conduit);
 444                         ver = ret;
 445                 }
 446         }
 447
 448         /*
 449          * Conveniently, the SMCCC and PSCI versions are encoded the
 450          * same way. No, this isn't accidental.
 451          */
 452         pr_info("SMC Calling Convention v%d.%d\n",
 453                 PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
 454
 455 }
 456
 457 static void __init psci_0_2_set_functions(void)
 458 {
 459         pr_info("Using standard PSCI v0.2 function IDs\n");
 460
 461         psci_ops = (struct psci_operations){
 462                 .get_version = psci_0_2_get_version,
 463                 .cpu_suspend = psci_0_2_cpu_suspend,
 464                 .cpu_off = psci_0_2_cpu_off,
 465                 .cpu_on = psci_0_2_cpu_on,
 466                 .migrate = psci_0_2_migrate,
 467                 .affinity_info = psci_affinity_info,
 468                 .migrate_info_type = psci_migrate_info_type,
 469         };
 470
 471         arm_pm_restart = psci_sys_reset;
 472
 473         pm_power_off = psci_sys_poweroff;
 474 }
 475
 476 /*
 477  * Probe function for PSCI firmware versions >= 0.2
 478  */
 479 static int __init psci_probe(void)
 480 {
 481         u32 ver = psci_0_2_get_version();
 482
 483         pr_info("PSCIv%d.%d detected in firmware.\n",
 484                         PSCI_VERSION_MAJOR(ver),
 485                         PSCI_VERSION_MINOR(ver));
 486
 487         if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
 488                 pr_err("Conflicting PSCI version detected.\n");
 489                 return -EINVAL;
 490         }
 491
 492         psci_0_2_set_functions();
 493
 494         psci_init_migrate();
 495
 496         if (PSCI_VERSION_MAJOR(ver) >= 1) {
 497                 psci_init_smccc();
 498                 psci_init_cpu_suspend();
 499                 psci_init_system_suspend();
 500                 psci_init_system_reset2();
 501         }
 502
 503         return 0;
 504 }
 505
 506 typedef int (*psci_initcall_t)(const struct device_node *);
 507
 508 /*
 509  * PSCI init function for PSCI versions >=0.2
 510  *
 511  * Probe based on PSCI PSCI_VERSION function
 512  */
 513 static int __init psci_0_2_init(struct device_node *np)
 514 {
 515         int err;
 516
 517         err = get_set_conduit_method(np);
 518         if (err)
 519                 return err;
 520
 521         /*
 522          * Starting with v0.2, the PSCI specification introduced a call
 523          * (PSCI_VERSION) that allows probing the firmware version, so
 524          * that PSCI function IDs and version specific initialization
 525          * can be carried out according to the specific version reported
 526          * by firmware
 527          */
 528         return psci_probe();
 529 }
 530
 531 /*
 532  * PSCI < v0.2 get PSCI Function IDs via DT.
 533  */
 534 static int __init psci_0_1_init(struct device_node *np)
 535 {
 536         u32 id;
 537         int err;
 538
 539         err = get_set_conduit_method(np);
 540         if (err)
 541                 return err;
 542
 543         pr_info("Using PSCI v0.1 Function IDs from DT\n");
 544
 545         psci_ops.get_version = psci_0_1_get_version;
 546
 547         if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 548                 psci_0_1_function_ids.cpu_suspend = id;
 549                 psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
 550         }
 551
 552         if (!of_property_read_u32(np, "cpu_off", &id)) {
 553                 psci_0_1_function_ids.cpu_off = id;
 554                 psci_ops.cpu_off = psci_0_1_cpu_off;
 555         }
 556
 557         if (!of_property_read_u32(np, "cpu_on", &id)) {
 558                 psci_0_1_function_ids.cpu_on = id;
 559                 psci_ops.cpu_on = psci_0_1_cpu_on;
 560         }
 561
 562         if (!of_property_read_u32(np, "migrate", &id)) {
 563                 psci_0_1_function_ids.migrate = id;
 564                 psci_ops.migrate = psci_0_1_migrate;
 565         }
 566
 567         return 0;
 568 }
 569
 570 static int __init psci_1_0_init(struct device_node *np)
 571 {
 572         int err;
 573
 574         err = psci_0_2_init(np);
 575         if (err)
 576                 return err;
 577
 578         if (psci_has_osi_support()) {
 579                 pr_info("OSI mode supported.\n");
 580
 581                 /* Default to PC mode. */
 582                 psci_set_osi_mode(false);
 583         }
 584
 585         return 0;
 586 }
 587
 588 static const struct of_device_id psci_of_match[] __initconst = {
 589         { .compatible = "arm,psci",     .data = psci_0_1_init},
 590         { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
 591         { .compatible = "arm,psci-1.0", .data = psci_1_0_init},
 592         {},
 593 };
 594
 595 int __init psci_dt_init(void)
 596 {
 597         struct device_node *np;
 598         const struct of_device_id *matched_np;
 599         psci_initcall_t init_fn;
 600         int ret;
 601
 602         np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
 603
 604         if (!np || !of_device_is_available(np))
 605                 return -ENODEV;
 606
 607         init_fn = (psci_initcall_t)matched_np->data;
 608         ret = init_fn(np);
 609
 610         of_node_put(np);
 611         return ret;
 612 }
 613
 614 #ifdef CONFIG_ACPI
 615 /*
 616  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
 617  * explicitly clarified in SBBR
 618  */
 619 int __init psci_acpi_init(void)
 620 {
 621         if (!acpi_psci_present()) {
 622                 pr_info("is not implemented in ACPI.\n");
 623                 return -EOPNOTSUPP;
 624         }
 625
 626         pr_info("probing for conduit method from ACPI.\n");
 627
 628         if (acpi_psci_use_hvc())
 629                 set_conduit(SMCCC_CONDUIT_HVC);
 630         else
 631                 set_conduit(SMCCC_CONDUIT_SMC);
 632
 633         return psci_probe();
 634 }
 635 #endif