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