drivers/firmware/psci.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * Copyright (C) 2015 ARM Limited
  12  */
  13
  14 #define pr_fmt(fmt) "psci: " fmt
  15
  16 #include <linux/acpi.h>
  17 #include <linux/arm-smccc.h>
  18 #include <linux/cpuidle.h>
  19 #include <linux/errno.h>
  20 #include <linux/linkage.h>
  21 #include <linux/of.h>
  22 #include <linux/pm.h>
  23 #include <linux/printk.h>
  24 #include <linux/psci.h>
  25 #include <linux/reboot.h>
  26 #include <linux/slab.h>
  27 #include <linux/suspend.h>
  28
  29 #include <uapi/linux/psci.h>
  30
  31 #include <asm/cpuidle.h>
  32 #include <asm/cputype.h>
  33 #include <asm/system_misc.h>
  34 #include <asm/smp_plat.h>
  35 #include <asm/suspend.h>
  36
  37 /*
  38  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
  39  * calls it is necessary to use SMC64 to pass or return 64-bit values.
  40  * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
  41  * (native-width) function ID.
  42  */
  43 #ifdef CONFIG_64BIT
  44 #define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN64_##name
  45 #else
  46 #define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN_##name
  47 #endif
  48
  49 /*
  50  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
  51  * calls to its resident CPU, so we must avoid issuing those. We never migrate
  52  * a Trusted OS even if it claims to be capable of migration -- doing so will
  53  * require cooperation with a Trusted OS driver.
  54  */
  55 static int resident_cpu = -1;
  56
  57 bool psci_tos_resident_on(int cpu)
  58 {
  59         return cpu == resident_cpu;
  60 }
  61
  62 struct psci_operations psci_ops;
  63
  64 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
  65                                 unsigned long, unsigned long);
  66 static psci_fn *invoke_psci_fn;
  67
  68 enum psci_function {
  69         PSCI_FN_CPU_SUSPEND,
  70         PSCI_FN_CPU_ON,
  71         PSCI_FN_CPU_OFF,
  72         PSCI_FN_MIGRATE,
  73         PSCI_FN_MAX,
  74 };
  75
  76 static u32 psci_function_id[PSCI_FN_MAX];
  77
  78 #define PSCI_0_2_POWER_STATE_MASK               \
  79                                 (PSCI_0_2_POWER_STATE_ID_MASK | \
  80                                 PSCI_0_2_POWER_STATE_TYPE_MASK | \
  81                                 PSCI_0_2_POWER_STATE_AFFL_MASK)
  82
  83 #define PSCI_1_0_EXT_POWER_STATE_MASK           \
  84                                 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
  85                                 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
  86
  87 static u32 psci_cpu_suspend_feature;
  88
  89 static inline bool psci_has_ext_power_state(void)
  90 {
  91         return psci_cpu_suspend_feature &
  92                                 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
  93 }
  94
  95 static inline bool psci_power_state_loses_context(u32 state)
  96 {
  97         const u32 mask = psci_has_ext_power_state() ?
  98                                         PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
  99                                         PSCI_0_2_POWER_STATE_TYPE_MASK;
 100
 101         return state & mask;
 102 }
 103
 104 static inline bool psci_power_state_is_valid(u32 state)
 105 {
 106         const u32 valid_mask = psci_has_ext_power_state() ?
 107                                PSCI_1_0_EXT_POWER_STATE_MASK :
 108                                PSCI_0_2_POWER_STATE_MASK;
 109
 110         return !(state & ~valid_mask);
 111 }
 112
 113 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
 114                         unsigned long arg0, unsigned long arg1,
 115                         unsigned long arg2)
 116 {
 117         struct arm_smccc_res res;
 118
 119         arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 120         return res.a0;
 121 }
 122
 123 static unsigned long __invoke_psci_fn_smc(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_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 130         return res.a0;
 131 }
 132
 133 static int psci_to_linux_errno(int errno)
 134 {
 135         switch (errno) {
 136         case PSCI_RET_SUCCESS:
 137                 return 0;
 138         case PSCI_RET_NOT_SUPPORTED:
 139                 return -EOPNOTSUPP;
 140         case PSCI_RET_INVALID_PARAMS:
 141         case PSCI_RET_INVALID_ADDRESS:
 142                 return -EINVAL;
 143         case PSCI_RET_DENIED:
 144                 return -EPERM;
 145         };
 146
 147         return -EINVAL;
 148 }
 149
 150 static u32 psci_get_version(void)
 151 {
 152         return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 153 }
 154
 155 static int psci_cpu_suspend(u32 state, unsigned long entry_point)
 156 {
 157         int err;
 158         u32 fn;
 159
 160         fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
 161         err = invoke_psci_fn(fn, state, entry_point, 0);
 162         return psci_to_linux_errno(err);
 163 }
 164
 165 static int psci_cpu_off(u32 state)
 166 {
 167         int err;
 168         u32 fn;
 169
 170         fn = psci_function_id[PSCI_FN_CPU_OFF];
 171         err = invoke_psci_fn(fn, state, 0, 0);
 172         return psci_to_linux_errno(err);
 173 }
 174
 175 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
 176 {
 177         int err;
 178         u32 fn;
 179
 180         fn = psci_function_id[PSCI_FN_CPU_ON];
 181         err = invoke_psci_fn(fn, cpuid, entry_point, 0);
 182         return psci_to_linux_errno(err);
 183 }
 184
 185 static int psci_migrate(unsigned long cpuid)
 186 {
 187         int err;
 188         u32 fn;
 189
 190         fn = psci_function_id[PSCI_FN_MIGRATE];
 191         err = invoke_psci_fn(fn, cpuid, 0, 0);
 192         return psci_to_linux_errno(err);
 193 }
 194
 195 static int psci_affinity_info(unsigned long target_affinity,
 196                 unsigned long lowest_affinity_level)
 197 {
 198         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
 199                               target_affinity, lowest_affinity_level, 0);
 200 }
 201
 202 static int psci_migrate_info_type(void)
 203 {
 204         return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 205 }
 206
 207 static unsigned long psci_migrate_info_up_cpu(void)
 208 {
 209         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
 210                               0, 0, 0);
 211 }
 212
 213 static int get_set_conduit_method(struct device_node *np)
 214 {
 215         const char *method;
 216
 217         pr_info("probing for conduit method from DT.\n");
 218
 219         if (of_property_read_string(np, "method", &method)) {
 220                 pr_warn("missing \"method\" property\n");
 221                 return -ENXIO;
 222         }
 223
 224         if (!strcmp("hvc", method)) {
 225                 invoke_psci_fn = __invoke_psci_fn_hvc;
 226         } else if (!strcmp("smc", method)) {
 227                 invoke_psci_fn = __invoke_psci_fn_smc;
 228         } else {
 229                 pr_warn("invalid \"method\" property: %s\n", method);
 230                 return -EINVAL;
 231         }
 232         return 0;
 233 }
 234
 235 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
 236 {
 237         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
 238 }
 239
 240 static void psci_sys_poweroff(void)
 241 {
 242         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
 243 }
 244
 245 static int __init psci_features(u32 psci_func_id)
 246 {
 247         return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
 248                               psci_func_id, 0, 0);
 249 }
 250
 251 #ifdef CONFIG_CPU_IDLE
 252 static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
 253
 254 static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
 255 {
 256         int i, ret, count = 0;
 257         u32 *psci_states;
 258         struct device_node *state_node;
 259
 260         /* Count idle states */
 261         while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
 262                                               count))) {
 263                 count++;
 264                 of_node_put(state_node);
 265         }
 266
 267         if (!count)
 268                 return -ENODEV;
 269
 270         psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
 271         if (!psci_states)
 272                 return -ENOMEM;
 273
 274         for (i = 0; i < count; i++) {
 275                 u32 state;
 276
 277                 state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
 278
 279                 ret = of_property_read_u32(state_node,
 280                                            "arm,psci-suspend-param",
 281                                            &state);
 282                 if (ret) {
 283                         pr_warn(" * %s missing arm,psci-suspend-param property\n",
 284                                 state_node->full_name);
 285                         of_node_put(state_node);
 286                         goto free_mem;
 287                 }
 288
 289                 of_node_put(state_node);
 290                 pr_debug("psci-power-state %#x index %d\n", state, i);
 291                 if (!psci_power_state_is_valid(state)) {
 292                         pr_warn("Invalid PSCI power state %#x\n", state);
 293                         ret = -EINVAL;
 294                         goto free_mem;
 295                 }
 296                 psci_states[i] = state;
 297         }
 298         /* Idle states parsed correctly, initialize per-cpu pointer */
 299         per_cpu(psci_power_state, cpu) = psci_states;
 300         return 0;
 301
 302 free_mem:
 303         kfree(psci_states);
 304         return ret;
 305 }
 306
 307 #ifdef CONFIG_ACPI
 308 #include <acpi/processor.h>
 309
 310 static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
 311 {
 312         int i, count;
 313         u32 *psci_states;
 314         struct acpi_lpi_state *lpi;
 315         struct acpi_processor *pr = per_cpu(processors, cpu);
 316
 317         if (unlikely(!pr || !pr->flags.has_lpi))
 318                 return -EINVAL;
 319
 320         count = pr->power.count - 1;
 321         if (count <= 0)
 322                 return -ENODEV;
 323
 324         psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
 325         if (!psci_states)
 326                 return -ENOMEM;
 327
 328         for (i = 0; i < count; i++) {
 329                 u32 state;
 330
 331                 lpi = &pr->power.lpi_states[i + 1];
 332                 /*
 333                  * Only bits[31:0] represent a PSCI power_state while
 334                  * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
 335                  */
 336                 state = lpi->address;
 337                 if (!psci_power_state_is_valid(state)) {
 338                         pr_warn("Invalid PSCI power state %#x\n", state);
 339                         kfree(psci_states);
 340                         return -EINVAL;
 341                 }
 342                 psci_states[i] = state;
 343         }
 344         /* Idle states parsed correctly, initialize per-cpu pointer */
 345         per_cpu(psci_power_state, cpu) = psci_states;
 346         return 0;
 347 }
 348 #else
 349 static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
 350 {
 351         return -EINVAL;
 352 }
 353 #endif
 354
 355 int psci_cpu_init_idle(unsigned int cpu)
 356 {
 357         struct device_node *cpu_node;
 358         int ret;
 359
 360         /*
 361          * If the PSCI cpu_suspend function hook has not been initialized
 362          * idle states must not be enabled, so bail out
 363          */
 364         if (!psci_ops.cpu_suspend)
 365                 return -EOPNOTSUPP;
 366
 367         if (!acpi_disabled)
 368                 return psci_acpi_cpu_init_idle(cpu);
 369
 370         cpu_node = of_get_cpu_node(cpu, NULL);
 371         if (!cpu_node)
 372                 return -ENODEV;
 373
 374         ret = psci_dt_cpu_init_idle(cpu_node, cpu);
 375
 376         of_node_put(cpu_node);
 377
 378         return ret;
 379 }
 380
 381 static int psci_suspend_finisher(unsigned long index)
 382 {
 383         u32 *state = __this_cpu_read(psci_power_state);
 384
 385         return psci_ops.cpu_suspend(state[index - 1],
 386                                     virt_to_phys(cpu_resume));
 387 }
 388
 389 int psci_cpu_suspend_enter(unsigned long index)
 390 {
 391         int ret;
 392         u32 *state = __this_cpu_read(psci_power_state);
 393         /*
 394          * idle state index 0 corresponds to wfi, should never be called
 395          * from the cpu_suspend operations
 396          */
 397         if (WARN_ON_ONCE(!index))
 398                 return -EINVAL;
 399
 400         if (!psci_power_state_loses_context(state[index - 1]))
 401                 ret = psci_ops.cpu_suspend(state[index - 1], 0);
 402         else
 403                 ret = cpu_suspend(index, psci_suspend_finisher);
 404
 405         return ret;
 406 }
 407
 408 /* ARM specific CPU idle operations */
 409 #ifdef CONFIG_ARM
 410 static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
 411         .suspend = psci_cpu_suspend_enter,
 412         .init = psci_dt_cpu_init_idle,
 413 };
 414
 415 CPUIDLE_METHOD_OF_DECLARE(psci, "psci", &psci_cpuidle_ops);
 416 #endif
 417 #endif
 418
 419 static int psci_system_suspend(unsigned long unused)
 420 {
 421         return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
 422                               virt_to_phys(cpu_resume), 0, 0);
 423 }
 424
 425 static int psci_system_suspend_enter(suspend_state_t state)
 426 {
 427         return cpu_suspend(0, psci_system_suspend);
 428 }
 429
 430 static const struct platform_suspend_ops psci_suspend_ops = {
 431         .valid          = suspend_valid_only_mem,
 432         .enter          = psci_system_suspend_enter,
 433 };
 434
 435 static void __init psci_init_system_suspend(void)
 436 {
 437         int ret;
 438
 439         if (!IS_ENABLED(CONFIG_SUSPEND))
 440                 return;
 441
 442         ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
 443
 444         if (ret != PSCI_RET_NOT_SUPPORTED)
 445                 suspend_set_ops(&psci_suspend_ops);
 446 }
 447
 448 static void __init psci_init_cpu_suspend(void)
 449 {
 450         int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
 451
 452         if (feature != PSCI_RET_NOT_SUPPORTED)
 453                 psci_cpu_suspend_feature = feature;
 454 }
 455
 456 /*
 457  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
 458  * return DENIED (which would be fatal).
 459  */
 460 static void __init psci_init_migrate(void)
 461 {
 462         unsigned long cpuid;
 463         int type, cpu = -1;
 464
 465         type = psci_ops.migrate_info_type();
 466
 467         if (type == PSCI_0_2_TOS_MP) {
 468                 pr_info("Trusted OS migration not required\n");
 469                 return;
 470         }
 471
 472         if (type == PSCI_RET_NOT_SUPPORTED) {
 473                 pr_info("MIGRATE_INFO_TYPE not supported.\n");
 474                 return;
 475         }
 476
 477         if (type != PSCI_0_2_TOS_UP_MIGRATE &&
 478             type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
 479                 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
 480                 return;
 481         }
 482
 483         cpuid = psci_migrate_info_up_cpu();
 484         if (cpuid & ~MPIDR_HWID_BITMASK) {
 485                 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
 486                         cpuid);
 487                 return;
 488         }
 489
 490         cpu = get_logical_index(cpuid);
 491         resident_cpu = cpu >= 0 ? cpu : -1;
 492
 493         pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
 494 }
 495
 496 static void __init psci_0_2_set_functions(void)
 497 {
 498         pr_info("Using standard PSCI v0.2 function IDs\n");
 499         psci_function_id[PSCI_FN_CPU_SUSPEND] =
 500                                         PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
 501         psci_ops.cpu_suspend = psci_cpu_suspend;
 502
 503         psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
 504         psci_ops.cpu_off = psci_cpu_off;
 505
 506         psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
 507         psci_ops.cpu_on = psci_cpu_on;
 508
 509         psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
 510         psci_ops.migrate = psci_migrate;
 511
 512         psci_ops.affinity_info = psci_affinity_info;
 513
 514         psci_ops.migrate_info_type = psci_migrate_info_type;
 515
 516         arm_pm_restart = psci_sys_reset;
 517
 518         pm_power_off = psci_sys_poweroff;
 519 }
 520
 521 /*
 522  * Probe function for PSCI firmware versions >= 0.2
 523  */
 524 static int __init psci_probe(void)
 525 {
 526         u32 ver = psci_get_version();
 527
 528         pr_info("PSCIv%d.%d detected in firmware.\n",
 529                         PSCI_VERSION_MAJOR(ver),
 530                         PSCI_VERSION_MINOR(ver));
 531
 532         if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
 533                 pr_err("Conflicting PSCI version detected.\n");
 534                 return -EINVAL;
 535         }
 536
 537         psci_0_2_set_functions();
 538
 539         psci_init_migrate();
 540
 541         if (PSCI_VERSION_MAJOR(ver) >= 1) {
 542                 psci_init_cpu_suspend();
 543                 psci_init_system_suspend();
 544         }
 545
 546         return 0;
 547 }
 548
 549 typedef int (*psci_initcall_t)(const struct device_node *);
 550
 551 /*
 552  * PSCI init function for PSCI versions >=0.2
 553  *
 554  * Probe based on PSCI PSCI_VERSION function
 555  */
 556 static int __init psci_0_2_init(struct device_node *np)
 557 {
 558         int err;
 559
 560         err = get_set_conduit_method(np);
 561
 562         if (err)
 563                 goto out_put_node;
 564         /*
 565          * Starting with v0.2, the PSCI specification introduced a call
 566          * (PSCI_VERSION) that allows probing the firmware version, so
 567          * that PSCI function IDs and version specific initialization
 568          * can be carried out according to the specific version reported
 569          * by firmware
 570          */
 571         err = psci_probe();
 572
 573 out_put_node:
 574         of_node_put(np);
 575         return err;
 576 }
 577
 578 /*
 579  * PSCI < v0.2 get PSCI Function IDs via DT.
 580  */
 581 static int __init psci_0_1_init(struct device_node *np)
 582 {
 583         u32 id;
 584         int err;
 585
 586         err = get_set_conduit_method(np);
 587
 588         if (err)
 589                 goto out_put_node;
 590
 591         pr_info("Using PSCI v0.1 Function IDs from DT\n");
 592
 593         if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 594                 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 595                 psci_ops.cpu_suspend = psci_cpu_suspend;
 596         }
 597
 598         if (!of_property_read_u32(np, "cpu_off", &id)) {
 599                 psci_function_id[PSCI_FN_CPU_OFF] = id;
 600                 psci_ops.cpu_off = psci_cpu_off;
 601         }
 602
 603         if (!of_property_read_u32(np, "cpu_on", &id)) {
 604                 psci_function_id[PSCI_FN_CPU_ON] = id;
 605                 psci_ops.cpu_on = psci_cpu_on;
 606         }
 607
 608         if (!of_property_read_u32(np, "migrate", &id)) {
 609                 psci_function_id[PSCI_FN_MIGRATE] = id;
 610                 psci_ops.migrate = psci_migrate;
 611         }
 612
 613 out_put_node:
 614         of_node_put(np);
 615         return err;
 616 }
 617
 618 static const struct of_device_id psci_of_match[] __initconst = {
 619         { .compatible = "arm,psci",     .data = psci_0_1_init},
 620         { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
 621         { .compatible = "arm,psci-1.0", .data = psci_0_2_init},
 622         {},
 623 };
 624
 625 int __init psci_dt_init(void)
 626 {
 627         struct device_node *np;
 628         const struct of_device_id *matched_np;
 629         psci_initcall_t init_fn;
 630
 631         np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
 632
 633         if (!np || !of_device_is_available(np))
 634                 return -ENODEV;
 635
 636         init_fn = (psci_initcall_t)matched_np->data;
 637         return init_fn(np);
 638 }
 639
 640 #ifdef CONFIG_ACPI
 641 /*
 642  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
 643  * explicitly clarified in SBBR
 644  */
 645 int __init psci_acpi_init(void)
 646 {
 647         if (!acpi_psci_present()) {
 648                 pr_info("is not implemented in ACPI.\n");
 649                 return -EOPNOTSUPP;
 650         }
 651
 652         pr_info("probing for conduit method from ACPI.\n");
 653
 654         if (acpi_psci_use_hvc())
 655                 invoke_psci_fn = __invoke_psci_fn_hvc;
 656         else
 657                 invoke_psci_fn = __invoke_psci_fn_smc;
 658
 659         return psci_probe();
 660 }
 661 #endif