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