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) 2013 ARM Limited 12 * 13 * Author: Will Deacon <will.deacon@arm.com> 14 */ 15 16 #define pr_fmt(fmt) "psci: " fmt 17 18 #include <linux/init.h> 19 #include <linux/of.h> 20 #include <linux/smp.h> 21 #include <linux/reboot.h> 22 #include <linux/pm.h> 23 #include <linux/delay.h> 24 #include <linux/slab.h> 25 #include <uapi/linux/psci.h> 26 27 #include <asm/compiler.h> 28 #include <asm/cpu_ops.h> 29 #include <asm/errno.h> 30 #include <asm/psci.h> 31 #include <asm/smp_plat.h> 32 #include <asm/suspend.h> 33 #include <asm/system_misc.h> 34 35 #define PSCI_POWER_STATE_TYPE_STANDBY 0 36 #define PSCI_POWER_STATE_TYPE_POWER_DOWN 1 37 38 struct psci_power_state { 39 u16 id; 40 u8 type; 41 u8 affinity_level; 42 }; 43 44 struct psci_operations { 45 int (*cpu_suspend)(struct psci_power_state state, 46 unsigned long entry_point); 47 int (*cpu_off)(struct psci_power_state state); 48 int (*cpu_on)(unsigned long cpuid, unsigned long entry_point); 49 int (*migrate)(unsigned long cpuid); 50 int (*affinity_info)(unsigned long target_affinity, 51 unsigned long lowest_affinity_level); 52 int (*migrate_info_type)(void); 53 }; 54 55 static struct psci_operations psci_ops; 56 57 static int (*invoke_psci_fn)(u64, u64, u64, u64); 58 typedef int (*psci_initcall_t)(const struct device_node *); 59 60 asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64); 61 asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64); 62 63 enum psci_function { 64 PSCI_FN_CPU_SUSPEND, 65 PSCI_FN_CPU_ON, 66 PSCI_FN_CPU_OFF, 67 PSCI_FN_MIGRATE, 68 PSCI_FN_AFFINITY_INFO, 69 PSCI_FN_MIGRATE_INFO_TYPE, 70 PSCI_FN_MAX, 71 }; 72 73 static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state); 74 75 static u32 psci_function_id[PSCI_FN_MAX]; 76 77 static int psci_to_linux_errno(int errno) 78 { 79 switch (errno) { 80 case PSCI_RET_SUCCESS: 81 return 0; 82 case PSCI_RET_NOT_SUPPORTED: 83 return -EOPNOTSUPP; 84 case PSCI_RET_INVALID_PARAMS: 85 return -EINVAL; 86 case PSCI_RET_DENIED: 87 return -EPERM; 88 }; 89 90 return -EINVAL; 91 } 92 93 static u32 psci_power_state_pack(struct psci_power_state state) 94 { 95 return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT) 96 & PSCI_0_2_POWER_STATE_ID_MASK) | 97 ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT) 98 & PSCI_0_2_POWER_STATE_TYPE_MASK) | 99 ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT) 100 & PSCI_0_2_POWER_STATE_AFFL_MASK); 101 } 102 103 static void psci_power_state_unpack(u32 power_state, 104 struct psci_power_state *state) 105 { 106 state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >> 107 PSCI_0_2_POWER_STATE_ID_SHIFT; 108 state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >> 109 PSCI_0_2_POWER_STATE_TYPE_SHIFT; 110 state->affinity_level = 111 (power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >> 112 PSCI_0_2_POWER_STATE_AFFL_SHIFT; 113 } 114 115 static int psci_get_version(void) 116 { 117 int err; 118 119 err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); 120 return err; 121 } 122 123 static int psci_cpu_suspend(struct psci_power_state state, 124 unsigned long entry_point) 125 { 126 int err; 127 u32 fn, power_state; 128 129 fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; 130 power_state = psci_power_state_pack(state); 131 err = invoke_psci_fn(fn, power_state, entry_point, 0); 132 return psci_to_linux_errno(err); 133 } 134 135 static int psci_cpu_off(struct psci_power_state state) 136 { 137 int err; 138 u32 fn, power_state; 139 140 fn = psci_function_id[PSCI_FN_CPU_OFF]; 141 power_state = psci_power_state_pack(state); 142 err = invoke_psci_fn(fn, power_state, 0, 0); 143 return psci_to_linux_errno(err); 144 } 145 146 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) 147 { 148 int err; 149 u32 fn; 150 151 fn = psci_function_id[PSCI_FN_CPU_ON]; 152 err = invoke_psci_fn(fn, cpuid, entry_point, 0); 153 return psci_to_linux_errno(err); 154 } 155 156 static int psci_migrate(unsigned long cpuid) 157 { 158 int err; 159 u32 fn; 160 161 fn = psci_function_id[PSCI_FN_MIGRATE]; 162 err = invoke_psci_fn(fn, cpuid, 0, 0); 163 return psci_to_linux_errno(err); 164 } 165 166 static int psci_affinity_info(unsigned long target_affinity, 167 unsigned long lowest_affinity_level) 168 { 169 int err; 170 u32 fn; 171 172 fn = psci_function_id[PSCI_FN_AFFINITY_INFO]; 173 err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0); 174 return err; 175 } 176 177 static int psci_migrate_info_type(void) 178 { 179 int err; 180 u32 fn; 181 182 fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE]; 183 err = invoke_psci_fn(fn, 0, 0, 0); 184 return err; 185 } 186 187 static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node, 188 unsigned int cpu) 189 { 190 int i, ret, count = 0; 191 struct psci_power_state *psci_states; 192 struct device_node *state_node; 193 194 /* 195 * If the PSCI cpu_suspend function hook has not been initialized 196 * idle states must not be enabled, so bail out 197 */ 198 if (!psci_ops.cpu_suspend) 199 return -EOPNOTSUPP; 200 201 /* Count idle states */ 202 while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states", 203 count))) { 204 count++; 205 of_node_put(state_node); 206 } 207 208 if (!count) 209 return -ENODEV; 210 211 psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); 212 if (!psci_states) 213 return -ENOMEM; 214 215 for (i = 0; i < count; i++) { 216 u32 psci_power_state; 217 218 state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); 219 220 ret = of_property_read_u32(state_node, 221 "arm,psci-suspend-param", 222 &psci_power_state); 223 if (ret) { 224 pr_warn(" * %s missing arm,psci-suspend-param property\n", 225 state_node->full_name); 226 of_node_put(state_node); 227 goto free_mem; 228 } 229 230 of_node_put(state_node); 231 pr_debug("psci-power-state %#x index %d\n", psci_power_state, 232 i); 233 psci_power_state_unpack(psci_power_state, &psci_states[i]); 234 } 235 /* Idle states parsed correctly, initialize per-cpu pointer */ 236 per_cpu(psci_power_state, cpu) = psci_states; 237 return 0; 238 239 free_mem: 240 kfree(psci_states); 241 return ret; 242 } 243 244 static int get_set_conduit_method(struct device_node *np) 245 { 246 const char *method; 247 248 pr_info("probing for conduit method from DT.\n"); 249 250 if (of_property_read_string(np, "method", &method)) { 251 pr_warn("missing \"method\" property\n"); 252 return -ENXIO; 253 } 254 255 if (!strcmp("hvc", method)) { 256 invoke_psci_fn = __invoke_psci_fn_hvc; 257 } else if (!strcmp("smc", method)) { 258 invoke_psci_fn = __invoke_psci_fn_smc; 259 } else { 260 pr_warn("invalid \"method\" property: %s\n", method); 261 return -EINVAL; 262 } 263 return 0; 264 } 265 266 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) 267 { 268 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); 269 } 270 271 static void psci_sys_poweroff(void) 272 { 273 invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); 274 } 275 276 /* 277 * PSCI Function IDs for v0.2+ are well defined so use 278 * standard values. 279 */ 280 static int __init psci_0_2_init(struct device_node *np) 281 { 282 int err, ver; 283 284 err = get_set_conduit_method(np); 285 286 if (err) 287 goto out_put_node; 288 289 ver = psci_get_version(); 290 291 if (ver == PSCI_RET_NOT_SUPPORTED) { 292 /* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */ 293 pr_err("PSCI firmware does not comply with the v0.2 spec.\n"); 294 err = -EOPNOTSUPP; 295 goto out_put_node; 296 } else { 297 pr_info("PSCIv%d.%d detected in firmware.\n", 298 PSCI_VERSION_MAJOR(ver), 299 PSCI_VERSION_MINOR(ver)); 300 301 if (PSCI_VERSION_MAJOR(ver) == 0 && 302 PSCI_VERSION_MINOR(ver) < 2) { 303 err = -EINVAL; 304 pr_err("Conflicting PSCI version detected.\n"); 305 goto out_put_node; 306 } 307 } 308 309 pr_info("Using standard PSCI v0.2 function IDs\n"); 310 psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND; 311 psci_ops.cpu_suspend = psci_cpu_suspend; 312 313 psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; 314 psci_ops.cpu_off = psci_cpu_off; 315 316 psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON; 317 psci_ops.cpu_on = psci_cpu_on; 318 319 psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE; 320 psci_ops.migrate = psci_migrate; 321 322 psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO; 323 psci_ops.affinity_info = psci_affinity_info; 324 325 psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = 326 PSCI_0_2_FN_MIGRATE_INFO_TYPE; 327 psci_ops.migrate_info_type = psci_migrate_info_type; 328 329 arm_pm_restart = psci_sys_reset; 330 331 pm_power_off = psci_sys_poweroff; 332 333 out_put_node: 334 of_node_put(np); 335 return err; 336 } 337 338 /* 339 * PSCI < v0.2 get PSCI Function IDs via DT. 340 */ 341 static int __init psci_0_1_init(struct device_node *np) 342 { 343 u32 id; 344 int err; 345 346 err = get_set_conduit_method(np); 347 348 if (err) 349 goto out_put_node; 350 351 pr_info("Using PSCI v0.1 Function IDs from DT\n"); 352 353 if (!of_property_read_u32(np, "cpu_suspend", &id)) { 354 psci_function_id[PSCI_FN_CPU_SUSPEND] = id; 355 psci_ops.cpu_suspend = psci_cpu_suspend; 356 } 357 358 if (!of_property_read_u32(np, "cpu_off", &id)) { 359 psci_function_id[PSCI_FN_CPU_OFF] = id; 360 psci_ops.cpu_off = psci_cpu_off; 361 } 362 363 if (!of_property_read_u32(np, "cpu_on", &id)) { 364 psci_function_id[PSCI_FN_CPU_ON] = id; 365 psci_ops.cpu_on = psci_cpu_on; 366 } 367 368 if (!of_property_read_u32(np, "migrate", &id)) { 369 psci_function_id[PSCI_FN_MIGRATE] = id; 370 psci_ops.migrate = psci_migrate; 371 } 372 373 out_put_node: 374 of_node_put(np); 375 return err; 376 } 377 378 static const struct of_device_id psci_of_match[] __initconst = { 379 { .compatible = "arm,psci", .data = psci_0_1_init}, 380 { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, 381 {}, 382 }; 383 384 int __init psci_init(void) 385 { 386 struct device_node *np; 387 const struct of_device_id *matched_np; 388 psci_initcall_t init_fn; 389 390 np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); 391 392 if (!np) 393 return -ENODEV; 394 395 init_fn = (psci_initcall_t)matched_np->data; 396 return init_fn(np); 397 } 398 399 #ifdef CONFIG_SMP 400 401 static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu) 402 { 403 return 0; 404 } 405 406 static int __init cpu_psci_cpu_prepare(unsigned int cpu) 407 { 408 if (!psci_ops.cpu_on) { 409 pr_err("no cpu_on method, not booting CPU%d\n", cpu); 410 return -ENODEV; 411 } 412 413 return 0; 414 } 415 416 static int cpu_psci_cpu_boot(unsigned int cpu) 417 { 418 int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry)); 419 if (err) 420 pr_err("failed to boot CPU%d (%d)\n", cpu, err); 421 422 return err; 423 } 424 425 #ifdef CONFIG_HOTPLUG_CPU 426 static int cpu_psci_cpu_disable(unsigned int cpu) 427 { 428 /* Fail early if we don't have CPU_OFF support */ 429 if (!psci_ops.cpu_off) 430 return -EOPNOTSUPP; 431 return 0; 432 } 433 434 static void cpu_psci_cpu_die(unsigned int cpu) 435 { 436 int ret; 437 /* 438 * There are no known implementations of PSCI actually using the 439 * power state field, pass a sensible default for now. 440 */ 441 struct psci_power_state state = { 442 .type = PSCI_POWER_STATE_TYPE_POWER_DOWN, 443 }; 444 445 ret = psci_ops.cpu_off(state); 446 447 pr_crit("unable to power off CPU%u (%d)\n", cpu, ret); 448 } 449 450 static int cpu_psci_cpu_kill(unsigned int cpu) 451 { 452 int err, i; 453 454 if (!psci_ops.affinity_info) 455 return 1; 456 /* 457 * cpu_kill could race with cpu_die and we can 458 * potentially end up declaring this cpu undead 459 * while it is dying. So, try again a few times. 460 */ 461 462 for (i = 0; i < 10; i++) { 463 err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); 464 if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { 465 pr_info("CPU%d killed.\n", cpu); 466 return 1; 467 } 468 469 msleep(10); 470 pr_info("Retrying again to check for CPU kill\n"); 471 } 472 473 pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", 474 cpu, err); 475 /* Make op_cpu_kill() fail. */ 476 return 0; 477 } 478 #endif 479 #endif 480 481 static int psci_suspend_finisher(unsigned long index) 482 { 483 struct psci_power_state *state = __this_cpu_read(psci_power_state); 484 485 return psci_ops.cpu_suspend(state[index - 1], 486 virt_to_phys(cpu_resume)); 487 } 488 489 static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index) 490 { 491 int ret; 492 struct psci_power_state *state = __this_cpu_read(psci_power_state); 493 /* 494 * idle state index 0 corresponds to wfi, should never be called 495 * from the cpu_suspend operations 496 */ 497 if (WARN_ON_ONCE(!index)) 498 return -EINVAL; 499 500 if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY) 501 ret = psci_ops.cpu_suspend(state[index - 1], 0); 502 else 503 ret = __cpu_suspend(index, psci_suspend_finisher); 504 505 return ret; 506 } 507 508 const struct cpu_operations cpu_psci_ops = { 509 .name = "psci", 510 #ifdef CONFIG_CPU_IDLE 511 .cpu_init_idle = cpu_psci_cpu_init_idle, 512 .cpu_suspend = cpu_psci_cpu_suspend, 513 #endif 514 #ifdef CONFIG_SMP 515 .cpu_init = cpu_psci_cpu_init, 516 .cpu_prepare = cpu_psci_cpu_prepare, 517 .cpu_boot = cpu_psci_cpu_boot, 518 #ifdef CONFIG_HOTPLUG_CPU 519 .cpu_disable = cpu_psci_cpu_disable, 520 .cpu_die = cpu_psci_cpu_die, 521 .cpu_kill = cpu_psci_cpu_kill, 522 #endif 523 #endif 524 }; 525 526