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 50 bool psci_tos_resident_on(int cpu) 51 { 52 return cpu == resident_cpu; 53 } 54 55 struct psci_operations psci_ops = { 56 .conduit = SMCCC_CONDUIT_NONE, 57 .smccc_version = SMCCC_VERSION_1_0, 58 }; 59 60 enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void) 61 { 62 if (psci_ops.smccc_version < SMCCC_VERSION_1_1) 63 return SMCCC_CONDUIT_NONE; 64 65 return psci_ops.conduit; 66 } 67 68 typedef unsigned long (psci_fn)(unsigned long, unsigned long, 69 unsigned long, unsigned long); 70 static psci_fn *invoke_psci_fn; 71 72 enum psci_function { 73 PSCI_FN_CPU_SUSPEND, 74 PSCI_FN_CPU_ON, 75 PSCI_FN_CPU_OFF, 76 PSCI_FN_MIGRATE, 77 PSCI_FN_MAX, 78 }; 79 80 static u32 psci_function_id[PSCI_FN_MAX]; 81 82 #define PSCI_0_2_POWER_STATE_MASK \ 83 (PSCI_0_2_POWER_STATE_ID_MASK | \ 84 PSCI_0_2_POWER_STATE_TYPE_MASK | \ 85 PSCI_0_2_POWER_STATE_AFFL_MASK) 86 87 #define PSCI_1_0_EXT_POWER_STATE_MASK \ 88 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \ 89 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK) 90 91 static u32 psci_cpu_suspend_feature; 92 static bool psci_system_reset2_supported; 93 94 static inline bool psci_has_ext_power_state(void) 95 { 96 return psci_cpu_suspend_feature & 97 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK; 98 } 99 100 static inline bool psci_has_osi_support(void) 101 { 102 return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED; 103 } 104 105 static inline bool psci_power_state_loses_context(u32 state) 106 { 107 const u32 mask = psci_has_ext_power_state() ? 108 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK : 109 PSCI_0_2_POWER_STATE_TYPE_MASK; 110 111 return state & mask; 112 } 113 114 bool psci_power_state_is_valid(u32 state) 115 { 116 const u32 valid_mask = psci_has_ext_power_state() ? 117 PSCI_1_0_EXT_POWER_STATE_MASK : 118 PSCI_0_2_POWER_STATE_MASK; 119 120 return !(state & ~valid_mask); 121 } 122 123 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id, 124 unsigned long arg0, unsigned long arg1, 125 unsigned long arg2) 126 { 127 struct arm_smccc_res res; 128 129 arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res); 130 return res.a0; 131 } 132 133 static unsigned long __invoke_psci_fn_smc(unsigned long function_id, 134 unsigned long arg0, unsigned long arg1, 135 unsigned long arg2) 136 { 137 struct arm_smccc_res res; 138 139 arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res); 140 return res.a0; 141 } 142 143 static int psci_to_linux_errno(int errno) 144 { 145 switch (errno) { 146 case PSCI_RET_SUCCESS: 147 return 0; 148 case PSCI_RET_NOT_SUPPORTED: 149 return -EOPNOTSUPP; 150 case PSCI_RET_INVALID_PARAMS: 151 case PSCI_RET_INVALID_ADDRESS: 152 return -EINVAL; 153 case PSCI_RET_DENIED: 154 return -EPERM; 155 }; 156 157 return -EINVAL; 158 } 159 160 static u32 psci_get_version(void) 161 { 162 return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); 163 } 164 165 static int psci_cpu_suspend(u32 state, unsigned long entry_point) 166 { 167 int err; 168 u32 fn; 169 170 fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; 171 err = invoke_psci_fn(fn, state, entry_point, 0); 172 return psci_to_linux_errno(err); 173 } 174 175 static int psci_cpu_off(u32 state) 176 { 177 int err; 178 u32 fn; 179 180 fn = psci_function_id[PSCI_FN_CPU_OFF]; 181 err = invoke_psci_fn(fn, state, 0, 0); 182 return psci_to_linux_errno(err); 183 } 184 185 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) 186 { 187 int err; 188 u32 fn; 189 190 fn = psci_function_id[PSCI_FN_CPU_ON]; 191 err = invoke_psci_fn(fn, cpuid, entry_point, 0); 192 return psci_to_linux_errno(err); 193 } 194 195 static int psci_migrate(unsigned long cpuid) 196 { 197 int err; 198 u32 fn; 199 200 fn = psci_function_id[PSCI_FN_MIGRATE]; 201 err = invoke_psci_fn(fn, cpuid, 0, 0); 202 return psci_to_linux_errno(err); 203 } 204 205 static int psci_affinity_info(unsigned long target_affinity, 206 unsigned long lowest_affinity_level) 207 { 208 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO), 209 target_affinity, lowest_affinity_level, 0); 210 } 211 212 static int psci_migrate_info_type(void) 213 { 214 return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0); 215 } 216 217 static unsigned long psci_migrate_info_up_cpu(void) 218 { 219 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU), 220 0, 0, 0); 221 } 222 223 static void set_conduit(enum arm_smccc_conduit conduit) 224 { 225 switch (conduit) { 226 case SMCCC_CONDUIT_HVC: 227 invoke_psci_fn = __invoke_psci_fn_hvc; 228 break; 229 case SMCCC_CONDUIT_SMC: 230 invoke_psci_fn = __invoke_psci_fn_smc; 231 break; 232 default: 233 WARN(1, "Unexpected PSCI conduit %d\n", conduit); 234 } 235 236 psci_ops.conduit = conduit; 237 } 238 239 static int get_set_conduit_method(struct device_node *np) 240 { 241 const char *method; 242 243 pr_info("probing for conduit method from DT.\n"); 244 245 if (of_property_read_string(np, "method", &method)) { 246 pr_warn("missing \"method\" property\n"); 247 return -ENXIO; 248 } 249 250 if (!strcmp("hvc", method)) { 251 set_conduit(SMCCC_CONDUIT_HVC); 252 } else if (!strcmp("smc", method)) { 253 set_conduit(SMCCC_CONDUIT_SMC); 254 } else { 255 pr_warn("invalid \"method\" property: %s\n", method); 256 return -EINVAL; 257 } 258 return 0; 259 } 260 261 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) 262 { 263 if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && 264 psci_system_reset2_supported) { 265 /* 266 * reset_type[31] = 0 (architectural) 267 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET) 268 * cookie = 0 (ignored by the implementation) 269 */ 270 invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0); 271 } else { 272 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); 273 } 274 } 275 276 static void psci_sys_poweroff(void) 277 { 278 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); 279 } 280 281 static int __init psci_features(u32 psci_func_id) 282 { 283 return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES, 284 psci_func_id, 0, 0); 285 } 286 287 #ifdef CONFIG_CPU_IDLE 288 static int psci_suspend_finisher(unsigned long state) 289 { 290 u32 power_state = state; 291 292 return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume)); 293 } 294 295 int psci_cpu_suspend_enter(u32 state) 296 { 297 int ret; 298 299 if (!psci_power_state_loses_context(state)) 300 ret = psci_ops.cpu_suspend(state, 0); 301 else 302 ret = cpu_suspend(state, psci_suspend_finisher); 303 304 return ret; 305 } 306 #endif 307 308 static int psci_system_suspend(unsigned long unused) 309 { 310 return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND), 311 __pa_symbol(cpu_resume), 0, 0); 312 } 313 314 static int psci_system_suspend_enter(suspend_state_t state) 315 { 316 return cpu_suspend(0, psci_system_suspend); 317 } 318 319 static const struct platform_suspend_ops psci_suspend_ops = { 320 .valid = suspend_valid_only_mem, 321 .enter = psci_system_suspend_enter, 322 }; 323 324 static void __init psci_init_system_reset2(void) 325 { 326 int ret; 327 328 ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2)); 329 330 if (ret != PSCI_RET_NOT_SUPPORTED) 331 psci_system_reset2_supported = true; 332 } 333 334 static void __init psci_init_system_suspend(void) 335 { 336 int ret; 337 338 if (!IS_ENABLED(CONFIG_SUSPEND)) 339 return; 340 341 ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND)); 342 343 if (ret != PSCI_RET_NOT_SUPPORTED) 344 suspend_set_ops(&psci_suspend_ops); 345 } 346 347 static void __init psci_init_cpu_suspend(void) 348 { 349 int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]); 350 351 if (feature != PSCI_RET_NOT_SUPPORTED) 352 psci_cpu_suspend_feature = feature; 353 } 354 355 /* 356 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to 357 * return DENIED (which would be fatal). 358 */ 359 static void __init psci_init_migrate(void) 360 { 361 unsigned long cpuid; 362 int type, cpu = -1; 363 364 type = psci_ops.migrate_info_type(); 365 366 if (type == PSCI_0_2_TOS_MP) { 367 pr_info("Trusted OS migration not required\n"); 368 return; 369 } 370 371 if (type == PSCI_RET_NOT_SUPPORTED) { 372 pr_info("MIGRATE_INFO_TYPE not supported.\n"); 373 return; 374 } 375 376 if (type != PSCI_0_2_TOS_UP_MIGRATE && 377 type != PSCI_0_2_TOS_UP_NO_MIGRATE) { 378 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type); 379 return; 380 } 381 382 cpuid = psci_migrate_info_up_cpu(); 383 if (cpuid & ~MPIDR_HWID_BITMASK) { 384 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n", 385 cpuid); 386 return; 387 } 388 389 cpu = get_logical_index(cpuid); 390 resident_cpu = cpu >= 0 ? cpu : -1; 391 392 pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); 393 } 394 395 static void __init psci_init_smccc(void) 396 { 397 u32 ver = ARM_SMCCC_VERSION_1_0; 398 int feature; 399 400 feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID); 401 402 if (feature != PSCI_RET_NOT_SUPPORTED) { 403 u32 ret; 404 ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0); 405 if (ret == ARM_SMCCC_VERSION_1_1) { 406 psci_ops.smccc_version = SMCCC_VERSION_1_1; 407 ver = ret; 408 } 409 } 410 411 /* 412 * Conveniently, the SMCCC and PSCI versions are encoded the 413 * same way. No, this isn't accidental. 414 */ 415 pr_info("SMC Calling Convention v%d.%d\n", 416 PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver)); 417 418 } 419 420 static void __init psci_0_2_set_functions(void) 421 { 422 pr_info("Using standard PSCI v0.2 function IDs\n"); 423 psci_ops.get_version = psci_get_version; 424 425 psci_function_id[PSCI_FN_CPU_SUSPEND] = 426 PSCI_FN_NATIVE(0_2, CPU_SUSPEND); 427 psci_ops.cpu_suspend = psci_cpu_suspend; 428 429 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; 430 psci_ops.cpu_off = psci_cpu_off; 431 432 psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON); 433 psci_ops.cpu_on = psci_cpu_on; 434 435 psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE); 436 psci_ops.migrate = psci_migrate; 437 438 psci_ops.affinity_info = psci_affinity_info; 439 440 psci_ops.migrate_info_type = psci_migrate_info_type; 441 442 arm_pm_restart = psci_sys_reset; 443 444 pm_power_off = psci_sys_poweroff; 445 } 446 447 /* 448 * Probe function for PSCI firmware versions >= 0.2 449 */ 450 static int __init psci_probe(void) 451 { 452 u32 ver = psci_get_version(); 453 454 pr_info("PSCIv%d.%d detected in firmware.\n", 455 PSCI_VERSION_MAJOR(ver), 456 PSCI_VERSION_MINOR(ver)); 457 458 if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) { 459 pr_err("Conflicting PSCI version detected.\n"); 460 return -EINVAL; 461 } 462 463 psci_0_2_set_functions(); 464 465 psci_init_migrate(); 466 467 if (PSCI_VERSION_MAJOR(ver) >= 1) { 468 psci_init_smccc(); 469 psci_init_cpu_suspend(); 470 psci_init_system_suspend(); 471 psci_init_system_reset2(); 472 } 473 474 return 0; 475 } 476 477 typedef int (*psci_initcall_t)(const struct device_node *); 478 479 /* 480 * PSCI init function for PSCI versions >=0.2 481 * 482 * Probe based on PSCI PSCI_VERSION function 483 */ 484 static int __init psci_0_2_init(struct device_node *np) 485 { 486 int err; 487 488 err = get_set_conduit_method(np); 489 if (err) 490 return err; 491 492 /* 493 * Starting with v0.2, the PSCI specification introduced a call 494 * (PSCI_VERSION) that allows probing the firmware version, so 495 * that PSCI function IDs and version specific initialization 496 * can be carried out according to the specific version reported 497 * by firmware 498 */ 499 return psci_probe(); 500 } 501 502 /* 503 * PSCI < v0.2 get PSCI Function IDs via DT. 504 */ 505 static int __init psci_0_1_init(struct device_node *np) 506 { 507 u32 id; 508 int err; 509 510 err = get_set_conduit_method(np); 511 if (err) 512 return err; 513 514 pr_info("Using PSCI v0.1 Function IDs from DT\n"); 515 516 if (!of_property_read_u32(np, "cpu_suspend", &id)) { 517 psci_function_id[PSCI_FN_CPU_SUSPEND] = id; 518 psci_ops.cpu_suspend = psci_cpu_suspend; 519 } 520 521 if (!of_property_read_u32(np, "cpu_off", &id)) { 522 psci_function_id[PSCI_FN_CPU_OFF] = id; 523 psci_ops.cpu_off = psci_cpu_off; 524 } 525 526 if (!of_property_read_u32(np, "cpu_on", &id)) { 527 psci_function_id[PSCI_FN_CPU_ON] = id; 528 psci_ops.cpu_on = psci_cpu_on; 529 } 530 531 if (!of_property_read_u32(np, "migrate", &id)) { 532 psci_function_id[PSCI_FN_MIGRATE] = id; 533 psci_ops.migrate = psci_migrate; 534 } 535 536 return 0; 537 } 538 539 static int __init psci_1_0_init(struct device_node *np) 540 { 541 int err; 542 543 err = psci_0_2_init(np); 544 if (err) 545 return err; 546 547 if (psci_has_osi_support()) 548 pr_info("OSI mode supported.\n"); 549 550 return 0; 551 } 552 553 static const struct of_device_id psci_of_match[] __initconst = { 554 { .compatible = "arm,psci", .data = psci_0_1_init}, 555 { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, 556 { .compatible = "arm,psci-1.0", .data = psci_1_0_init}, 557 {}, 558 }; 559 560 int __init psci_dt_init(void) 561 { 562 struct device_node *np; 563 const struct of_device_id *matched_np; 564 psci_initcall_t init_fn; 565 int ret; 566 567 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); 568 569 if (!np || !of_device_is_available(np)) 570 return -ENODEV; 571 572 init_fn = (psci_initcall_t)matched_np->data; 573 ret = init_fn(np); 574 575 of_node_put(np); 576 return ret; 577 } 578 579 #ifdef CONFIG_ACPI 580 /* 581 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's 582 * explicitly clarified in SBBR 583 */ 584 int __init psci_acpi_init(void) 585 { 586 if (!acpi_psci_present()) { 587 pr_info("is not implemented in ACPI.\n"); 588 return -EOPNOTSUPP; 589 } 590 591 pr_info("probing for conduit method from ACPI.\n"); 592 593 if (acpi_psci_use_hvc()) 594 set_conduit(SMCCC_CONDUIT_HVC); 595 else 596 set_conduit(SMCCC_CONDUIT_SMC); 597 598 return psci_probe(); 599 } 600 #endif 601