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 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 int psci_set_osi_mode(void) 166 { 167 int err; 168 169 err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, 170 PSCI_1_0_SUSPEND_MODE_OSI, 0, 0); 171 return psci_to_linux_errno(err); 172 } 173 174 static int psci_cpu_suspend(u32 state, unsigned long entry_point) 175 { 176 int err; 177 u32 fn; 178 179 fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; 180 err = invoke_psci_fn(fn, state, entry_point, 0); 181 return psci_to_linux_errno(err); 182 } 183 184 static int psci_cpu_off(u32 state) 185 { 186 int err; 187 u32 fn; 188 189 fn = psci_function_id[PSCI_FN_CPU_OFF]; 190 err = invoke_psci_fn(fn, state, 0, 0); 191 return psci_to_linux_errno(err); 192 } 193 194 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) 195 { 196 int err; 197 u32 fn; 198 199 fn = psci_function_id[PSCI_FN_CPU_ON]; 200 err = invoke_psci_fn(fn, cpuid, entry_point, 0); 201 return psci_to_linux_errno(err); 202 } 203 204 static int psci_migrate(unsigned long cpuid) 205 { 206 int err; 207 u32 fn; 208 209 fn = psci_function_id[PSCI_FN_MIGRATE]; 210 err = invoke_psci_fn(fn, cpuid, 0, 0); 211 return psci_to_linux_errno(err); 212 } 213 214 static int psci_affinity_info(unsigned long target_affinity, 215 unsigned long lowest_affinity_level) 216 { 217 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO), 218 target_affinity, lowest_affinity_level, 0); 219 } 220 221 static int psci_migrate_info_type(void) 222 { 223 return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0); 224 } 225 226 static unsigned long psci_migrate_info_up_cpu(void) 227 { 228 return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU), 229 0, 0, 0); 230 } 231 232 static void set_conduit(enum arm_smccc_conduit conduit) 233 { 234 switch (conduit) { 235 case SMCCC_CONDUIT_HVC: 236 invoke_psci_fn = __invoke_psci_fn_hvc; 237 break; 238 case SMCCC_CONDUIT_SMC: 239 invoke_psci_fn = __invoke_psci_fn_smc; 240 break; 241 default: 242 WARN(1, "Unexpected PSCI conduit %d\n", conduit); 243 } 244 245 psci_ops.conduit = conduit; 246 } 247 248 static int get_set_conduit_method(struct device_node *np) 249 { 250 const char *method; 251 252 pr_info("probing for conduit method from DT.\n"); 253 254 if (of_property_read_string(np, "method", &method)) { 255 pr_warn("missing \"method\" property\n"); 256 return -ENXIO; 257 } 258 259 if (!strcmp("hvc", method)) { 260 set_conduit(SMCCC_CONDUIT_HVC); 261 } else if (!strcmp("smc", method)) { 262 set_conduit(SMCCC_CONDUIT_SMC); 263 } else { 264 pr_warn("invalid \"method\" property: %s\n", method); 265 return -EINVAL; 266 } 267 return 0; 268 } 269 270 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) 271 { 272 if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && 273 psci_system_reset2_supported) { 274 /* 275 * reset_type[31] = 0 (architectural) 276 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET) 277 * cookie = 0 (ignored by the implementation) 278 */ 279 invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0); 280 } else { 281 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); 282 } 283 } 284 285 static void psci_sys_poweroff(void) 286 { 287 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); 288 } 289 290 static int __init psci_features(u32 psci_func_id) 291 { 292 return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES, 293 psci_func_id, 0, 0); 294 } 295 296 #ifdef CONFIG_CPU_IDLE 297 static int psci_suspend_finisher(unsigned long state) 298 { 299 u32 power_state = state; 300 301 return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume)); 302 } 303 304 int psci_cpu_suspend_enter(u32 state) 305 { 306 int ret; 307 308 if (!psci_power_state_loses_context(state)) 309 ret = psci_ops.cpu_suspend(state, 0); 310 else 311 ret = cpu_suspend(state, psci_suspend_finisher); 312 313 return ret; 314 } 315 #endif 316 317 static int psci_system_suspend(unsigned long unused) 318 { 319 return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND), 320 __pa_symbol(cpu_resume), 0, 0); 321 } 322 323 static int psci_system_suspend_enter(suspend_state_t state) 324 { 325 return cpu_suspend(0, psci_system_suspend); 326 } 327 328 static const struct platform_suspend_ops psci_suspend_ops = { 329 .valid = suspend_valid_only_mem, 330 .enter = psci_system_suspend_enter, 331 }; 332 333 static void __init psci_init_system_reset2(void) 334 { 335 int ret; 336 337 ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2)); 338 339 if (ret != PSCI_RET_NOT_SUPPORTED) 340 psci_system_reset2_supported = true; 341 } 342 343 static void __init psci_init_system_suspend(void) 344 { 345 int ret; 346 347 if (!IS_ENABLED(CONFIG_SUSPEND)) 348 return; 349 350 ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND)); 351 352 if (ret != PSCI_RET_NOT_SUPPORTED) 353 suspend_set_ops(&psci_suspend_ops); 354 } 355 356 static void __init psci_init_cpu_suspend(void) 357 { 358 int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]); 359 360 if (feature != PSCI_RET_NOT_SUPPORTED) 361 psci_cpu_suspend_feature = feature; 362 } 363 364 /* 365 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to 366 * return DENIED (which would be fatal). 367 */ 368 static void __init psci_init_migrate(void) 369 { 370 unsigned long cpuid; 371 int type, cpu = -1; 372 373 type = psci_ops.migrate_info_type(); 374 375 if (type == PSCI_0_2_TOS_MP) { 376 pr_info("Trusted OS migration not required\n"); 377 return; 378 } 379 380 if (type == PSCI_RET_NOT_SUPPORTED) { 381 pr_info("MIGRATE_INFO_TYPE not supported.\n"); 382 return; 383 } 384 385 if (type != PSCI_0_2_TOS_UP_MIGRATE && 386 type != PSCI_0_2_TOS_UP_NO_MIGRATE) { 387 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type); 388 return; 389 } 390 391 cpuid = psci_migrate_info_up_cpu(); 392 if (cpuid & ~MPIDR_HWID_BITMASK) { 393 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n", 394 cpuid); 395 return; 396 } 397 398 cpu = get_logical_index(cpuid); 399 resident_cpu = cpu >= 0 ? cpu : -1; 400 401 pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); 402 } 403 404 static void __init psci_init_smccc(void) 405 { 406 u32 ver = ARM_SMCCC_VERSION_1_0; 407 int feature; 408 409 feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID); 410 411 if (feature != PSCI_RET_NOT_SUPPORTED) { 412 u32 ret; 413 ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0); 414 if (ret == ARM_SMCCC_VERSION_1_1) { 415 psci_ops.smccc_version = SMCCC_VERSION_1_1; 416 ver = ret; 417 } 418 } 419 420 /* 421 * Conveniently, the SMCCC and PSCI versions are encoded the 422 * same way. No, this isn't accidental. 423 */ 424 pr_info("SMC Calling Convention v%d.%d\n", 425 PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver)); 426 427 } 428 429 static void __init psci_0_2_set_functions(void) 430 { 431 pr_info("Using standard PSCI v0.2 function IDs\n"); 432 psci_ops.get_version = psci_get_version; 433 434 psci_function_id[PSCI_FN_CPU_SUSPEND] = 435 PSCI_FN_NATIVE(0_2, CPU_SUSPEND); 436 psci_ops.cpu_suspend = psci_cpu_suspend; 437 438 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; 439 psci_ops.cpu_off = psci_cpu_off; 440 441 psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON); 442 psci_ops.cpu_on = psci_cpu_on; 443 444 psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE); 445 psci_ops.migrate = psci_migrate; 446 447 psci_ops.affinity_info = psci_affinity_info; 448 449 psci_ops.migrate_info_type = psci_migrate_info_type; 450 451 arm_pm_restart = psci_sys_reset; 452 453 pm_power_off = psci_sys_poweroff; 454 } 455 456 /* 457 * Probe function for PSCI firmware versions >= 0.2 458 */ 459 static int __init psci_probe(void) 460 { 461 u32 ver = psci_get_version(); 462 463 pr_info("PSCIv%d.%d detected in firmware.\n", 464 PSCI_VERSION_MAJOR(ver), 465 PSCI_VERSION_MINOR(ver)); 466 467 if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) { 468 pr_err("Conflicting PSCI version detected.\n"); 469 return -EINVAL; 470 } 471 472 psci_0_2_set_functions(); 473 474 psci_init_migrate(); 475 476 if (PSCI_VERSION_MAJOR(ver) >= 1) { 477 psci_init_smccc(); 478 psci_init_cpu_suspend(); 479 psci_init_system_suspend(); 480 psci_init_system_reset2(); 481 } 482 483 return 0; 484 } 485 486 typedef int (*psci_initcall_t)(const struct device_node *); 487 488 /* 489 * PSCI init function for PSCI versions >=0.2 490 * 491 * Probe based on PSCI PSCI_VERSION function 492 */ 493 static int __init psci_0_2_init(struct device_node *np) 494 { 495 int err; 496 497 err = get_set_conduit_method(np); 498 if (err) 499 return err; 500 501 /* 502 * Starting with v0.2, the PSCI specification introduced a call 503 * (PSCI_VERSION) that allows probing the firmware version, so 504 * that PSCI function IDs and version specific initialization 505 * can be carried out according to the specific version reported 506 * by firmware 507 */ 508 return psci_probe(); 509 } 510 511 /* 512 * PSCI < v0.2 get PSCI Function IDs via DT. 513 */ 514 static int __init psci_0_1_init(struct device_node *np) 515 { 516 u32 id; 517 int err; 518 519 err = get_set_conduit_method(np); 520 if (err) 521 return err; 522 523 pr_info("Using PSCI v0.1 Function IDs from DT\n"); 524 525 if (!of_property_read_u32(np, "cpu_suspend", &id)) { 526 psci_function_id[PSCI_FN_CPU_SUSPEND] = id; 527 psci_ops.cpu_suspend = psci_cpu_suspend; 528 } 529 530 if (!of_property_read_u32(np, "cpu_off", &id)) { 531 psci_function_id[PSCI_FN_CPU_OFF] = id; 532 psci_ops.cpu_off = psci_cpu_off; 533 } 534 535 if (!of_property_read_u32(np, "cpu_on", &id)) { 536 psci_function_id[PSCI_FN_CPU_ON] = id; 537 psci_ops.cpu_on = psci_cpu_on; 538 } 539 540 if (!of_property_read_u32(np, "migrate", &id)) { 541 psci_function_id[PSCI_FN_MIGRATE] = id; 542 psci_ops.migrate = psci_migrate; 543 } 544 545 return 0; 546 } 547 548 static int __init psci_1_0_init(struct device_node *np) 549 { 550 int err; 551 552 err = psci_0_2_init(np); 553 if (err) 554 return err; 555 556 if (psci_has_osi_support()) { 557 pr_info("OSI mode supported.\n"); 558 559 /* Default to PC mode. */ 560 invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, 561 PSCI_1_0_SUSPEND_MODE_PC, 0, 0); 562 } 563 564 return 0; 565 } 566 567 static const struct of_device_id psci_of_match[] __initconst = { 568 { .compatible = "arm,psci", .data = psci_0_1_init}, 569 { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, 570 { .compatible = "arm,psci-1.0", .data = psci_1_0_init}, 571 {}, 572 }; 573 574 int __init psci_dt_init(void) 575 { 576 struct device_node *np; 577 const struct of_device_id *matched_np; 578 psci_initcall_t init_fn; 579 int ret; 580 581 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); 582 583 if (!np || !of_device_is_available(np)) 584 return -ENODEV; 585 586 init_fn = (psci_initcall_t)matched_np->data; 587 ret = init_fn(np); 588 589 of_node_put(np); 590 return ret; 591 } 592 593 #ifdef CONFIG_ACPI 594 /* 595 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's 596 * explicitly clarified in SBBR 597 */ 598 int __init psci_acpi_init(void) 599 { 600 if (!acpi_psci_present()) { 601 pr_info("is not implemented in ACPI.\n"); 602 return -EOPNOTSUPP; 603 } 604 605 pr_info("probing for conduit method from ACPI.\n"); 606 607 if (acpi_psci_use_hvc()) 608 set_conduit(SMCCC_CONDUIT_HVC); 609 else 610 set_conduit(SMCCC_CONDUIT_SMC); 611 612 return psci_probe(); 613 } 614 #endif 615