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/errno.h>
  18 #include <linux/linkage.h>
  19 #include <linux/of.h>
  20 #include <linux/pm.h>
  21 #include <linux/printk.h>
  22 #include <linux/psci.h>
  23 #include <linux/reboot.h>
  24 #include <linux/suspend.h>
  25
  26 #include <uapi/linux/psci.h>
  27
  28 #include <asm/cputype.h>
  29 #include <asm/system_misc.h>
  30 #include <asm/smp_plat.h>
  31 #include <asm/suspend.h>
  32
  33 /*
  34  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
  35  * calls it is necessary to use SMC64 to pass or return 64-bit values.
  36  * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
  37  * (native-width) function ID.
  38  */
  39 #ifdef CONFIG_64BIT
  40 #define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN64_##name
  41 #else
  42 #define PSCI_FN_NATIVE(version, name)   PSCI_##version##_FN_##name
  43 #endif
  44
  45 /*
  46  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
  47  * calls to its resident CPU, so we must avoid issuing those. We never migrate
  48  * a Trusted OS even if it claims to be capable of migration -- doing so will
  49  * require cooperation with a Trusted OS driver.
  50  */
  51 static int resident_cpu = -1;
  52
  53 bool psci_tos_resident_on(int cpu)
  54 {
  55         return cpu == resident_cpu;
  56 }
  57
  58 struct psci_operations psci_ops;
  59
  60 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
  61                                 unsigned long, unsigned long);
  62 static psci_fn *invoke_psci_fn;
  63
  64 enum psci_function {
  65         PSCI_FN_CPU_SUSPEND,
  66         PSCI_FN_CPU_ON,
  67         PSCI_FN_CPU_OFF,
  68         PSCI_FN_MIGRATE,
  69         PSCI_FN_MAX,
  70 };
  71
  72 static u32 psci_function_id[PSCI_FN_MAX];
  73
  74 #define PSCI_0_2_POWER_STATE_MASK               \
  75                                 (PSCI_0_2_POWER_STATE_ID_MASK | \
  76                                 PSCI_0_2_POWER_STATE_TYPE_MASK | \
  77                                 PSCI_0_2_POWER_STATE_AFFL_MASK)
  78
  79 #define PSCI_1_0_EXT_POWER_STATE_MASK           \
  80                                 (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
  81                                 PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
  82
  83 static u32 psci_cpu_suspend_feature;
  84
  85 static inline bool psci_has_ext_power_state(void)
  86 {
  87         return psci_cpu_suspend_feature &
  88                                 PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
  89 }
  90
  91 bool psci_power_state_loses_context(u32 state)
  92 {
  93         const u32 mask = psci_has_ext_power_state() ?
  94                                         PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
  95                                         PSCI_0_2_POWER_STATE_TYPE_MASK;
  96
  97         return state & mask;
  98 }
  99
 100 bool psci_power_state_is_valid(u32 state)
 101 {
 102         const u32 valid_mask = psci_has_ext_power_state() ?
 103                                PSCI_1_0_EXT_POWER_STATE_MASK :
 104                                PSCI_0_2_POWER_STATE_MASK;
 105
 106         return !(state & ~valid_mask);
 107 }
 108
 109 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
 110                         unsigned long arg0, unsigned long arg1,
 111                         unsigned long arg2)
 112 {
 113         struct arm_smccc_res res;
 114
 115         arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 116         return res.a0;
 117 }
 118
 119 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
 120                         unsigned long arg0, unsigned long arg1,
 121                         unsigned long arg2)
 122 {
 123         struct arm_smccc_res res;
 124
 125         arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
 126         return res.a0;
 127 }
 128
 129 static int psci_to_linux_errno(int errno)
 130 {
 131         switch (errno) {
 132         case PSCI_RET_SUCCESS:
 133                 return 0;
 134         case PSCI_RET_NOT_SUPPORTED:
 135                 return -EOPNOTSUPP;
 136         case PSCI_RET_INVALID_PARAMS:
 137         case PSCI_RET_INVALID_ADDRESS:
 138                 return -EINVAL;
 139         case PSCI_RET_DENIED:
 140                 return -EPERM;
 141         };
 142
 143         return -EINVAL;
 144 }
 145
 146 static u32 psci_get_version(void)
 147 {
 148         return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
 149 }
 150
 151 static int psci_cpu_suspend(u32 state, unsigned long entry_point)
 152 {
 153         int err;
 154         u32 fn;
 155
 156         fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
 157         err = invoke_psci_fn(fn, state, entry_point, 0);
 158         return psci_to_linux_errno(err);
 159 }
 160
 161 static int psci_cpu_off(u32 state)
 162 {
 163         int err;
 164         u32 fn;
 165
 166         fn = psci_function_id[PSCI_FN_CPU_OFF];
 167         err = invoke_psci_fn(fn, state, 0, 0);
 168         return psci_to_linux_errno(err);
 169 }
 170
 171 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
 172 {
 173         int err;
 174         u32 fn;
 175
 176         fn = psci_function_id[PSCI_FN_CPU_ON];
 177         err = invoke_psci_fn(fn, cpuid, entry_point, 0);
 178         return psci_to_linux_errno(err);
 179 }
 180
 181 static int psci_migrate(unsigned long cpuid)
 182 {
 183         int err;
 184         u32 fn;
 185
 186         fn = psci_function_id[PSCI_FN_MIGRATE];
 187         err = invoke_psci_fn(fn, cpuid, 0, 0);
 188         return psci_to_linux_errno(err);
 189 }
 190
 191 static int psci_affinity_info(unsigned long target_affinity,
 192                 unsigned long lowest_affinity_level)
 193 {
 194         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
 195                               target_affinity, lowest_affinity_level, 0);
 196 }
 197
 198 static int psci_migrate_info_type(void)
 199 {
 200         return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
 201 }
 202
 203 static unsigned long psci_migrate_info_up_cpu(void)
 204 {
 205         return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
 206                               0, 0, 0);
 207 }
 208
 209 static int get_set_conduit_method(struct device_node *np)
 210 {
 211         const char *method;
 212
 213         pr_info("probing for conduit method from DT.\n");
 214
 215         if (of_property_read_string(np, "method", &method)) {
 216                 pr_warn("missing \"method\" property\n");
 217                 return -ENXIO;
 218         }
 219
 220         if (!strcmp("hvc", method)) {
 221                 invoke_psci_fn = __invoke_psci_fn_hvc;
 222         } else if (!strcmp("smc", method)) {
 223                 invoke_psci_fn = __invoke_psci_fn_smc;
 224         } else {
 225                 pr_warn("invalid \"method\" property: %s\n", method);
 226                 return -EINVAL;
 227         }
 228         return 0;
 229 }
 230
 231 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
 232 {
 233         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
 234 }
 235
 236 static void psci_sys_poweroff(void)
 237 {
 238         invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
 239 }
 240
 241 static int __init psci_features(u32 psci_func_id)
 242 {
 243         return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
 244                               psci_func_id, 0, 0);
 245 }
 246
 247 static int psci_system_suspend(unsigned long unused)
 248 {
 249         return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
 250                               virt_to_phys(cpu_resume), 0, 0);
 251 }
 252
 253 static int psci_system_suspend_enter(suspend_state_t state)
 254 {
 255         return cpu_suspend(0, psci_system_suspend);
 256 }
 257
 258 static const struct platform_suspend_ops psci_suspend_ops = {
 259         .valid          = suspend_valid_only_mem,
 260         .enter          = psci_system_suspend_enter,
 261 };
 262
 263 static void __init psci_init_system_suspend(void)
 264 {
 265         int ret;
 266
 267         if (!IS_ENABLED(CONFIG_SUSPEND))
 268                 return;
 269
 270         ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
 271
 272         if (ret != PSCI_RET_NOT_SUPPORTED)
 273                 suspend_set_ops(&psci_suspend_ops);
 274 }
 275
 276 static void __init psci_init_cpu_suspend(void)
 277 {
 278         int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
 279
 280         if (feature != PSCI_RET_NOT_SUPPORTED)
 281                 psci_cpu_suspend_feature = feature;
 282 }
 283
 284 /*
 285  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
 286  * return DENIED (which would be fatal).
 287  */
 288 static void __init psci_init_migrate(void)
 289 {
 290         unsigned long cpuid;
 291         int type, cpu = -1;
 292
 293         type = psci_ops.migrate_info_type();
 294
 295         if (type == PSCI_0_2_TOS_MP) {
 296                 pr_info("Trusted OS migration not required\n");
 297                 return;
 298         }
 299
 300         if (type == PSCI_RET_NOT_SUPPORTED) {
 301                 pr_info("MIGRATE_INFO_TYPE not supported.\n");
 302                 return;
 303         }
 304
 305         if (type != PSCI_0_2_TOS_UP_MIGRATE &&
 306             type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
 307                 pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
 308                 return;
 309         }
 310
 311         cpuid = psci_migrate_info_up_cpu();
 312         if (cpuid & ~MPIDR_HWID_BITMASK) {
 313                 pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
 314                         cpuid);
 315                 return;
 316         }
 317
 318         cpu = get_logical_index(cpuid);
 319         resident_cpu = cpu >= 0 ? cpu : -1;
 320
 321         pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
 322 }
 323
 324 static void __init psci_0_2_set_functions(void)
 325 {
 326         pr_info("Using standard PSCI v0.2 function IDs\n");
 327         psci_function_id[PSCI_FN_CPU_SUSPEND] =
 328                                         PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
 329         psci_ops.cpu_suspend = psci_cpu_suspend;
 330
 331         psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
 332         psci_ops.cpu_off = psci_cpu_off;
 333
 334         psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
 335         psci_ops.cpu_on = psci_cpu_on;
 336
 337         psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
 338         psci_ops.migrate = psci_migrate;
 339
 340         psci_ops.affinity_info = psci_affinity_info;
 341
 342         psci_ops.migrate_info_type = psci_migrate_info_type;
 343
 344         arm_pm_restart = psci_sys_reset;
 345
 346         pm_power_off = psci_sys_poweroff;
 347 }
 348
 349 /*
 350  * Probe function for PSCI firmware versions >= 0.2
 351  */
 352 static int __init psci_probe(void)
 353 {
 354         u32 ver = psci_get_version();
 355
 356         pr_info("PSCIv%d.%d detected in firmware.\n",
 357                         PSCI_VERSION_MAJOR(ver),
 358                         PSCI_VERSION_MINOR(ver));
 359
 360         if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
 361                 pr_err("Conflicting PSCI version detected.\n");
 362                 return -EINVAL;
 363         }
 364
 365         psci_0_2_set_functions();
 366
 367         psci_init_migrate();
 368
 369         if (PSCI_VERSION_MAJOR(ver) >= 1) {
 370                 psci_init_cpu_suspend();
 371                 psci_init_system_suspend();
 372         }
 373
 374         return 0;
 375 }
 376
 377 typedef int (*psci_initcall_t)(const struct device_node *);
 378
 379 /*
 380  * PSCI init function for PSCI versions >=0.2
 381  *
 382  * Probe based on PSCI PSCI_VERSION function
 383  */
 384 static int __init psci_0_2_init(struct device_node *np)
 385 {
 386         int err;
 387
 388         err = get_set_conduit_method(np);
 389
 390         if (err)
 391                 goto out_put_node;
 392         /*
 393          * Starting with v0.2, the PSCI specification introduced a call
 394          * (PSCI_VERSION) that allows probing the firmware version, so
 395          * that PSCI function IDs and version specific initialization
 396          * can be carried out according to the specific version reported
 397          * by firmware
 398          */
 399         err = psci_probe();
 400
 401 out_put_node:
 402         of_node_put(np);
 403         return err;
 404 }
 405
 406 /*
 407  * PSCI < v0.2 get PSCI Function IDs via DT.
 408  */
 409 static int __init psci_0_1_init(struct device_node *np)
 410 {
 411         u32 id;
 412         int err;
 413
 414         err = get_set_conduit_method(np);
 415
 416         if (err)
 417                 goto out_put_node;
 418
 419         pr_info("Using PSCI v0.1 Function IDs from DT\n");
 420
 421         if (!of_property_read_u32(np, "cpu_suspend", &id)) {
 422                 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
 423                 psci_ops.cpu_suspend = psci_cpu_suspend;
 424         }
 425
 426         if (!of_property_read_u32(np, "cpu_off", &id)) {
 427                 psci_function_id[PSCI_FN_CPU_OFF] = id;
 428                 psci_ops.cpu_off = psci_cpu_off;
 429         }
 430
 431         if (!of_property_read_u32(np, "cpu_on", &id)) {
 432                 psci_function_id[PSCI_FN_CPU_ON] = id;
 433                 psci_ops.cpu_on = psci_cpu_on;
 434         }
 435
 436         if (!of_property_read_u32(np, "migrate", &id)) {
 437                 psci_function_id[PSCI_FN_MIGRATE] = id;
 438                 psci_ops.migrate = psci_migrate;
 439         }
 440
 441 out_put_node:
 442         of_node_put(np);
 443         return err;
 444 }
 445
 446 static const struct of_device_id const psci_of_match[] __initconst = {
 447         { .compatible = "arm,psci",     .data = psci_0_1_init},
 448         { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
 449         { .compatible = "arm,psci-1.0", .data = psci_0_2_init},
 450         {},
 451 };
 452
 453 int __init psci_dt_init(void)
 454 {
 455         struct device_node *np;
 456         const struct of_device_id *matched_np;
 457         psci_initcall_t init_fn;
 458
 459         np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
 460
 461         if (!np)
 462                 return -ENODEV;
 463
 464         init_fn = (psci_initcall_t)matched_np->data;
 465         return init_fn(np);
 466 }
 467
 468 #ifdef CONFIG_ACPI
 469 /*
 470  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
 471  * explicitly clarified in SBBR
 472  */
 473 int __init psci_acpi_init(void)
 474 {
 475         if (!acpi_psci_present()) {
 476                 pr_info("is not implemented in ACPI.\n");
 477                 return -EOPNOTSUPP;
 478         }
 479
 480         pr_info("probing for conduit method from ACPI.\n");
 481
 482         if (acpi_psci_use_hvc())
 483                 invoke_psci_fn = __invoke_psci_fn_hvc;
 484         else
 485                 invoke_psci_fn = __invoke_psci_fn_smc;
 486
 487         return psci_probe();
 488 }
 489 #endif