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