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