1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * processor_idle - idle state submodule to the ACPI processor driver 4 * 5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de> 8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 9 * - Added processor hotplug support 10 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 11 * - Added support for C3 on SMP 12 */ 13 #define pr_fmt(fmt) "ACPI: " fmt 14 15 #include <linux/module.h> 16 #include <linux/acpi.h> 17 #include <linux/dmi.h> 18 #include <linux/sched.h> /* need_resched() */ 19 #include <linux/sort.h> 20 #include <linux/tick.h> 21 #include <linux/cpuidle.h> 22 #include <linux/cpu.h> 23 #include <linux/minmax.h> 24 #include <linux/perf_event.h> 25 #include <acpi/processor.h> 26 #include <linux/context_tracking.h> 27 28 /* 29 * Include the apic definitions for x86 to have the APIC timer related defines 30 * available also for UP (on SMP it gets magically included via linux/smp.h). 31 * asm/acpi.h is not an option, as it would require more include magic. Also 32 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 33 */ 34 #ifdef CONFIG_X86 35 #include <asm/apic.h> 36 #include <asm/cpu.h> 37 #endif 38 39 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) 40 41 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 42 module_param(max_cstate, uint, 0400); 43 static bool nocst __read_mostly; 44 module_param(nocst, bool, 0400); 45 static bool bm_check_disable __read_mostly; 46 module_param(bm_check_disable, bool, 0400); 47 48 static unsigned int latency_factor __read_mostly = 2; 49 module_param(latency_factor, uint, 0644); 50 51 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 52 53 struct cpuidle_driver acpi_idle_driver = { 54 .name = "acpi_idle", 55 .owner = THIS_MODULE, 56 }; 57 58 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 59 static 60 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 61 62 static int disabled_by_idle_boot_param(void) 63 { 64 return boot_option_idle_override == IDLE_POLL || 65 boot_option_idle_override == IDLE_HALT; 66 } 67 68 /* 69 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 70 * For now disable this. Probably a bug somewhere else. 71 * 72 * To skip this limit, boot/load with a large max_cstate limit. 73 */ 74 static int set_max_cstate(const struct dmi_system_id *id) 75 { 76 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 77 return 0; 78 79 pr_notice("%s detected - limiting to C%ld max_cstate." 80 " Override with \"processor.max_cstate=%d\"\n", id->ident, 81 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 82 83 max_cstate = (long)id->driver_data; 84 85 return 0; 86 } 87 88 static const struct dmi_system_id processor_power_dmi_table[] = { 89 { set_max_cstate, "Clevo 5600D", { 90 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 91 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 92 (void *)2}, 93 { set_max_cstate, "Pavilion zv5000", { 94 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 95 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 96 (void *)1}, 97 { set_max_cstate, "Asus L8400B", { 98 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 99 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 100 (void *)1}, 101 {}, 102 }; 103 104 105 /* 106 * Callers should disable interrupts before the call and enable 107 * interrupts after return. 108 */ 109 static void __cpuidle acpi_safe_halt(void) 110 { 111 if (!tif_need_resched()) { 112 raw_safe_halt(); 113 raw_local_irq_disable(); 114 } 115 } 116 117 #ifdef ARCH_APICTIMER_STOPS_ON_C3 118 119 /* 120 * Some BIOS implementations switch to C3 in the published C2 state. 121 * This seems to be a common problem on AMD boxen, but other vendors 122 * are affected too. We pick the most conservative approach: we assume 123 * that the local APIC stops in both C2 and C3. 124 */ 125 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 126 struct acpi_processor_cx *cx) 127 { 128 struct acpi_processor_power *pwr = &pr->power; 129 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 130 131 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 132 return; 133 134 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 135 type = ACPI_STATE_C1; 136 137 /* 138 * Check, if one of the previous states already marked the lapic 139 * unstable 140 */ 141 if (pwr->timer_broadcast_on_state < state) 142 return; 143 144 if (cx->type >= type) 145 pr->power.timer_broadcast_on_state = state; 146 } 147 148 static void __lapic_timer_propagate_broadcast(void *arg) 149 { 150 struct acpi_processor *pr = arg; 151 152 if (pr->power.timer_broadcast_on_state < INT_MAX) 153 tick_broadcast_enable(); 154 else 155 tick_broadcast_disable(); 156 } 157 158 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 159 { 160 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 161 (void *)pr, 1); 162 } 163 164 /* Power(C) State timer broadcast control */ 165 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 166 struct acpi_processor_cx *cx) 167 { 168 return cx - pr->power.states >= pr->power.timer_broadcast_on_state; 169 } 170 171 #else 172 173 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 174 struct acpi_processor_cx *cstate) { } 175 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 176 177 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 178 struct acpi_processor_cx *cx) 179 { 180 return false; 181 } 182 183 #endif 184 185 #if defined(CONFIG_X86) 186 static void tsc_check_state(int state) 187 { 188 switch (boot_cpu_data.x86_vendor) { 189 case X86_VENDOR_HYGON: 190 case X86_VENDOR_AMD: 191 case X86_VENDOR_INTEL: 192 case X86_VENDOR_CENTAUR: 193 case X86_VENDOR_ZHAOXIN: 194 /* 195 * AMD Fam10h TSC will tick in all 196 * C/P/S0/S1 states when this bit is set. 197 */ 198 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 199 return; 200 fallthrough; 201 default: 202 /* TSC could halt in idle, so notify users */ 203 if (state > ACPI_STATE_C1) 204 mark_tsc_unstable("TSC halts in idle"); 205 } 206 } 207 #else 208 static void tsc_check_state(int state) { return; } 209 #endif 210 211 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 212 { 213 214 if (!pr->pblk) 215 return -ENODEV; 216 217 /* if info is obtained from pblk/fadt, type equals state */ 218 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 219 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 220 221 #ifndef CONFIG_HOTPLUG_CPU 222 /* 223 * Check for P_LVL2_UP flag before entering C2 and above on 224 * an SMP system. 225 */ 226 if ((num_online_cpus() > 1) && 227 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 228 return -ENODEV; 229 #endif 230 231 /* determine C2 and C3 address from pblk */ 232 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 233 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 234 235 /* determine latencies from FADT */ 236 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 237 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 238 239 /* 240 * FADT specified C2 latency must be less than or equal to 241 * 100 microseconds. 242 */ 243 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 244 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n", 245 acpi_gbl_FADT.c2_latency); 246 /* invalidate C2 */ 247 pr->power.states[ACPI_STATE_C2].address = 0; 248 } 249 250 /* 251 * FADT supplied C3 latency must be less than or equal to 252 * 1000 microseconds. 253 */ 254 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 255 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n", 256 acpi_gbl_FADT.c3_latency); 257 /* invalidate C3 */ 258 pr->power.states[ACPI_STATE_C3].address = 0; 259 } 260 261 acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n", 262 pr->power.states[ACPI_STATE_C2].address, 263 pr->power.states[ACPI_STATE_C3].address); 264 265 snprintf(pr->power.states[ACPI_STATE_C2].desc, 266 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x", 267 pr->power.states[ACPI_STATE_C2].address); 268 snprintf(pr->power.states[ACPI_STATE_C3].desc, 269 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x", 270 pr->power.states[ACPI_STATE_C3].address); 271 272 return 0; 273 } 274 275 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 276 { 277 if (!pr->power.states[ACPI_STATE_C1].valid) { 278 /* set the first C-State to C1 */ 279 /* all processors need to support C1 */ 280 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 281 pr->power.states[ACPI_STATE_C1].valid = 1; 282 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 283 284 snprintf(pr->power.states[ACPI_STATE_C1].desc, 285 ACPI_CX_DESC_LEN, "ACPI HLT"); 286 } 287 /* the C0 state only exists as a filler in our array */ 288 pr->power.states[ACPI_STATE_C0].valid = 1; 289 return 0; 290 } 291 292 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 293 { 294 int ret; 295 296 if (nocst) 297 return -ENODEV; 298 299 ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power); 300 if (ret) 301 return ret; 302 303 if (!pr->power.count) 304 return -EFAULT; 305 306 pr->flags.has_cst = 1; 307 return 0; 308 } 309 310 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 311 struct acpi_processor_cx *cx) 312 { 313 static int bm_check_flag = -1; 314 static int bm_control_flag = -1; 315 316 317 if (!cx->address) 318 return; 319 320 /* 321 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 322 * DMA transfers are used by any ISA device to avoid livelock. 323 * Note that we could disable Type-F DMA (as recommended by 324 * the erratum), but this is known to disrupt certain ISA 325 * devices thus we take the conservative approach. 326 */ 327 if (errata.piix4.fdma) { 328 acpi_handle_debug(pr->handle, 329 "C3 not supported on PIIX4 with Type-F DMA\n"); 330 return; 331 } 332 333 /* All the logic here assumes flags.bm_check is same across all CPUs */ 334 if (bm_check_flag == -1) { 335 /* Determine whether bm_check is needed based on CPU */ 336 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 337 bm_check_flag = pr->flags.bm_check; 338 bm_control_flag = pr->flags.bm_control; 339 } else { 340 pr->flags.bm_check = bm_check_flag; 341 pr->flags.bm_control = bm_control_flag; 342 } 343 344 if (pr->flags.bm_check) { 345 if (!pr->flags.bm_control) { 346 if (pr->flags.has_cst != 1) { 347 /* bus mastering control is necessary */ 348 acpi_handle_debug(pr->handle, 349 "C3 support requires BM control\n"); 350 return; 351 } else { 352 /* Here we enter C3 without bus mastering */ 353 acpi_handle_debug(pr->handle, 354 "C3 support without BM control\n"); 355 } 356 } 357 } else { 358 /* 359 * WBINVD should be set in fadt, for C3 state to be 360 * supported on when bm_check is not required. 361 */ 362 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 363 acpi_handle_debug(pr->handle, 364 "Cache invalidation should work properly" 365 " for C3 to be enabled on SMP systems\n"); 366 return; 367 } 368 } 369 370 /* 371 * Otherwise we've met all of our C3 requirements. 372 * Normalize the C3 latency to expidite policy. Enable 373 * checking of bus mastering status (bm_check) so we can 374 * use this in our C3 policy 375 */ 376 cx->valid = 1; 377 378 /* 379 * On older chipsets, BM_RLD needs to be set 380 * in order for Bus Master activity to wake the 381 * system from C3. Newer chipsets handle DMA 382 * during C3 automatically and BM_RLD is a NOP. 383 * In either case, the proper way to 384 * handle BM_RLD is to set it and leave it set. 385 */ 386 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 387 } 388 389 static int acpi_cst_latency_cmp(const void *a, const void *b) 390 { 391 const struct acpi_processor_cx *x = a, *y = b; 392 393 if (!(x->valid && y->valid)) 394 return 0; 395 if (x->latency > y->latency) 396 return 1; 397 if (x->latency < y->latency) 398 return -1; 399 return 0; 400 } 401 static void acpi_cst_latency_swap(void *a, void *b, int n) 402 { 403 struct acpi_processor_cx *x = a, *y = b; 404 405 if (!(x->valid && y->valid)) 406 return; 407 swap(x->latency, y->latency); 408 } 409 410 static int acpi_processor_power_verify(struct acpi_processor *pr) 411 { 412 unsigned int i; 413 unsigned int working = 0; 414 unsigned int last_latency = 0; 415 unsigned int last_type = 0; 416 bool buggy_latency = false; 417 418 pr->power.timer_broadcast_on_state = INT_MAX; 419 420 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 421 struct acpi_processor_cx *cx = &pr->power.states[i]; 422 423 switch (cx->type) { 424 case ACPI_STATE_C1: 425 cx->valid = 1; 426 break; 427 428 case ACPI_STATE_C2: 429 if (!cx->address) 430 break; 431 cx->valid = 1; 432 break; 433 434 case ACPI_STATE_C3: 435 acpi_processor_power_verify_c3(pr, cx); 436 break; 437 } 438 if (!cx->valid) 439 continue; 440 if (cx->type >= last_type && cx->latency < last_latency) 441 buggy_latency = true; 442 last_latency = cx->latency; 443 last_type = cx->type; 444 445 lapic_timer_check_state(i, pr, cx); 446 tsc_check_state(cx->type); 447 working++; 448 } 449 450 if (buggy_latency) { 451 pr_notice("FW issue: working around C-state latencies out of order\n"); 452 sort(&pr->power.states[1], max_cstate, 453 sizeof(struct acpi_processor_cx), 454 acpi_cst_latency_cmp, 455 acpi_cst_latency_swap); 456 } 457 458 lapic_timer_propagate_broadcast(pr); 459 460 return working; 461 } 462 463 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 464 { 465 unsigned int i; 466 int result; 467 468 469 /* NOTE: the idle thread may not be running while calling 470 * this function */ 471 472 /* Zero initialize all the C-states info. */ 473 memset(pr->power.states, 0, sizeof(pr->power.states)); 474 475 result = acpi_processor_get_power_info_cst(pr); 476 if (result == -ENODEV) 477 result = acpi_processor_get_power_info_fadt(pr); 478 479 if (result) 480 return result; 481 482 acpi_processor_get_power_info_default(pr); 483 484 pr->power.count = acpi_processor_power_verify(pr); 485 486 /* 487 * if one state of type C2 or C3 is available, mark this 488 * CPU as being "idle manageable" 489 */ 490 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 491 if (pr->power.states[i].valid) { 492 pr->power.count = i; 493 pr->flags.power = 1; 494 } 495 } 496 497 return 0; 498 } 499 500 /** 501 * acpi_idle_bm_check - checks if bus master activity was detected 502 */ 503 static int acpi_idle_bm_check(void) 504 { 505 u32 bm_status = 0; 506 507 if (bm_check_disable) 508 return 0; 509 510 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 511 if (bm_status) 512 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 513 /* 514 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 515 * the true state of bus mastering activity; forcing us to 516 * manually check the BMIDEA bit of each IDE channel. 517 */ 518 else if (errata.piix4.bmisx) { 519 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 520 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 521 bm_status = 1; 522 } 523 return bm_status; 524 } 525 526 static __cpuidle void io_idle(unsigned long addr) 527 { 528 /* IO port based C-state */ 529 inb(addr); 530 531 #ifdef CONFIG_X86 532 /* No delay is needed if we are in guest */ 533 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) 534 return; 535 /* 536 * Modern (>=Nehalem) Intel systems use ACPI via intel_idle, 537 * not this code. Assume that any Intel systems using this 538 * are ancient and may need the dummy wait. This also assumes 539 * that the motivating chipset issue was Intel-only. 540 */ 541 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) 542 return; 543 #endif 544 /* 545 * Dummy wait op - must do something useless after P_LVL2 read 546 * because chipsets cannot guarantee that STPCLK# signal gets 547 * asserted in time to freeze execution properly 548 * 549 * This workaround has been in place since the original ACPI 550 * implementation was merged, circa 2002. 551 * 552 * If a profile is pointing to this instruction, please first 553 * consider moving your system to a more modern idle 554 * mechanism. 555 */ 556 inl(acpi_gbl_FADT.xpm_timer_block.address); 557 } 558 559 /** 560 * acpi_idle_do_entry - enter idle state using the appropriate method 561 * @cx: cstate data 562 * 563 * Caller disables interrupt before call and enables interrupt after return. 564 */ 565 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 566 { 567 perf_lopwr_cb(true); 568 569 if (cx->entry_method == ACPI_CSTATE_FFH) { 570 /* Call into architectural FFH based C-state */ 571 acpi_processor_ffh_cstate_enter(cx); 572 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 573 acpi_safe_halt(); 574 } else { 575 io_idle(cx->address); 576 } 577 578 perf_lopwr_cb(false); 579 } 580 581 /** 582 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 583 * @dev: the target CPU 584 * @index: the index of suggested state 585 */ 586 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 587 { 588 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 589 590 ACPI_FLUSH_CPU_CACHE(); 591 592 while (1) { 593 594 if (cx->entry_method == ACPI_CSTATE_HALT) 595 raw_safe_halt(); 596 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 597 io_idle(cx->address); 598 } else 599 return -ENODEV; 600 } 601 602 /* Never reached */ 603 return 0; 604 } 605 606 static __always_inline bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 607 { 608 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 609 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 610 } 611 612 static int c3_cpu_count; 613 static DEFINE_RAW_SPINLOCK(c3_lock); 614 615 /** 616 * acpi_idle_enter_bm - enters C3 with proper BM handling 617 * @drv: cpuidle driver 618 * @pr: Target processor 619 * @cx: Target state context 620 * @index: index of target state 621 */ 622 static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv, 623 struct acpi_processor *pr, 624 struct acpi_processor_cx *cx, 625 int index) 626 { 627 static struct acpi_processor_cx safe_cx = { 628 .entry_method = ACPI_CSTATE_HALT, 629 }; 630 631 /* 632 * disable bus master 633 * bm_check implies we need ARB_DIS 634 * bm_control implies whether we can do ARB_DIS 635 * 636 * That leaves a case where bm_check is set and bm_control is not set. 637 * In that case we cannot do much, we enter C3 without doing anything. 638 */ 639 bool dis_bm = pr->flags.bm_control; 640 641 instrumentation_begin(); 642 643 /* If we can skip BM, demote to a safe state. */ 644 if (!cx->bm_sts_skip && acpi_idle_bm_check()) { 645 dis_bm = false; 646 index = drv->safe_state_index; 647 if (index >= 0) { 648 cx = this_cpu_read(acpi_cstate[index]); 649 } else { 650 cx = &safe_cx; 651 index = -EBUSY; 652 } 653 } 654 655 if (dis_bm) { 656 raw_spin_lock(&c3_lock); 657 c3_cpu_count++; 658 /* Disable bus master arbitration when all CPUs are in C3 */ 659 if (c3_cpu_count == num_online_cpus()) 660 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 661 raw_spin_unlock(&c3_lock); 662 } 663 664 ct_cpuidle_enter(); 665 666 acpi_idle_do_entry(cx); 667 668 ct_cpuidle_exit(); 669 670 /* Re-enable bus master arbitration */ 671 if (dis_bm) { 672 raw_spin_lock(&c3_lock); 673 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 674 c3_cpu_count--; 675 raw_spin_unlock(&c3_lock); 676 } 677 678 instrumentation_end(); 679 680 return index; 681 } 682 683 static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev, 684 struct cpuidle_driver *drv, int index) 685 { 686 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 687 struct acpi_processor *pr; 688 689 pr = __this_cpu_read(processors); 690 if (unlikely(!pr)) 691 return -EINVAL; 692 693 if (cx->type != ACPI_STATE_C1) { 694 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) 695 return acpi_idle_enter_bm(drv, pr, cx, index); 696 697 /* C2 to C1 demotion. */ 698 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 699 index = ACPI_IDLE_STATE_START; 700 cx = per_cpu(acpi_cstate[index], dev->cpu); 701 } 702 } 703 704 if (cx->type == ACPI_STATE_C3) 705 ACPI_FLUSH_CPU_CACHE(); 706 707 acpi_idle_do_entry(cx); 708 709 return index; 710 } 711 712 static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev, 713 struct cpuidle_driver *drv, int index) 714 { 715 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 716 717 if (cx->type == ACPI_STATE_C3) { 718 struct acpi_processor *pr = __this_cpu_read(processors); 719 720 if (unlikely(!pr)) 721 return 0; 722 723 if (pr->flags.bm_check) { 724 u8 bm_sts_skip = cx->bm_sts_skip; 725 726 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */ 727 cx->bm_sts_skip = 1; 728 acpi_idle_enter_bm(drv, pr, cx, index); 729 cx->bm_sts_skip = bm_sts_skip; 730 731 return 0; 732 } else { 733 ACPI_FLUSH_CPU_CACHE(); 734 } 735 } 736 acpi_idle_do_entry(cx); 737 738 return 0; 739 } 740 741 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 742 struct cpuidle_device *dev) 743 { 744 int i, count = ACPI_IDLE_STATE_START; 745 struct acpi_processor_cx *cx; 746 struct cpuidle_state *state; 747 748 if (max_cstate == 0) 749 max_cstate = 1; 750 751 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 752 state = &acpi_idle_driver.states[count]; 753 cx = &pr->power.states[i]; 754 755 if (!cx->valid) 756 continue; 757 758 per_cpu(acpi_cstate[count], dev->cpu) = cx; 759 760 if (lapic_timer_needs_broadcast(pr, cx)) 761 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 762 763 if (cx->type == ACPI_STATE_C3) { 764 state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; 765 if (pr->flags.bm_check) 766 state->flags |= CPUIDLE_FLAG_RCU_IDLE; 767 } 768 769 count++; 770 if (count == CPUIDLE_STATE_MAX) 771 break; 772 } 773 774 if (!count) 775 return -EINVAL; 776 777 return 0; 778 } 779 780 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 781 { 782 int i, count; 783 struct acpi_processor_cx *cx; 784 struct cpuidle_state *state; 785 struct cpuidle_driver *drv = &acpi_idle_driver; 786 787 if (max_cstate == 0) 788 max_cstate = 1; 789 790 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 791 cpuidle_poll_state_init(drv); 792 count = 1; 793 } else { 794 count = 0; 795 } 796 797 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 798 cx = &pr->power.states[i]; 799 800 if (!cx->valid) 801 continue; 802 803 state = &drv->states[count]; 804 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 805 strscpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 806 state->exit_latency = cx->latency; 807 state->target_residency = cx->latency * latency_factor; 808 state->enter = acpi_idle_enter; 809 810 state->flags = 0; 811 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 || 812 cx->type == ACPI_STATE_C3) { 813 state->enter_dead = acpi_idle_play_dead; 814 if (cx->type != ACPI_STATE_C3) 815 drv->safe_state_index = count; 816 } 817 /* 818 * Halt-induced C1 is not good for ->enter_s2idle, because it 819 * re-enables interrupts on exit. Moreover, C1 is generally not 820 * particularly interesting from the suspend-to-idle angle, so 821 * avoid C1 and the situations in which we may need to fall back 822 * to it altogether. 823 */ 824 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 825 state->enter_s2idle = acpi_idle_enter_s2idle; 826 827 count++; 828 if (count == CPUIDLE_STATE_MAX) 829 break; 830 } 831 832 drv->state_count = count; 833 834 if (!count) 835 return -EINVAL; 836 837 return 0; 838 } 839 840 static inline void acpi_processor_cstate_first_run_checks(void) 841 { 842 static int first_run; 843 844 if (first_run) 845 return; 846 dmi_check_system(processor_power_dmi_table); 847 max_cstate = acpi_processor_cstate_check(max_cstate); 848 if (max_cstate < ACPI_C_STATES_MAX) 849 pr_notice("processor limited to max C-state %d\n", max_cstate); 850 851 first_run++; 852 853 if (nocst) 854 return; 855 856 acpi_processor_claim_cst_control(); 857 } 858 #else 859 860 static inline int disabled_by_idle_boot_param(void) { return 0; } 861 static inline void acpi_processor_cstate_first_run_checks(void) { } 862 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 863 { 864 return -ENODEV; 865 } 866 867 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 868 struct cpuidle_device *dev) 869 { 870 return -EINVAL; 871 } 872 873 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 874 { 875 return -EINVAL; 876 } 877 878 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 879 880 struct acpi_lpi_states_array { 881 unsigned int size; 882 unsigned int composite_states_size; 883 struct acpi_lpi_state *entries; 884 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 885 }; 886 887 static int obj_get_integer(union acpi_object *obj, u32 *value) 888 { 889 if (obj->type != ACPI_TYPE_INTEGER) 890 return -EINVAL; 891 892 *value = obj->integer.value; 893 return 0; 894 } 895 896 static int acpi_processor_evaluate_lpi(acpi_handle handle, 897 struct acpi_lpi_states_array *info) 898 { 899 acpi_status status; 900 int ret = 0; 901 int pkg_count, state_idx = 1, loop; 902 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 903 union acpi_object *lpi_data; 904 struct acpi_lpi_state *lpi_state; 905 906 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 907 if (ACPI_FAILURE(status)) { 908 acpi_handle_debug(handle, "No _LPI, giving up\n"); 909 return -ENODEV; 910 } 911 912 lpi_data = buffer.pointer; 913 914 /* There must be at least 4 elements = 3 elements + 1 package */ 915 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 916 lpi_data->package.count < 4) { 917 pr_debug("not enough elements in _LPI\n"); 918 ret = -ENODATA; 919 goto end; 920 } 921 922 pkg_count = lpi_data->package.elements[2].integer.value; 923 924 /* Validate number of power states. */ 925 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 926 pr_debug("count given by _LPI is not valid\n"); 927 ret = -ENODATA; 928 goto end; 929 } 930 931 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 932 if (!lpi_state) { 933 ret = -ENOMEM; 934 goto end; 935 } 936 937 info->size = pkg_count; 938 info->entries = lpi_state; 939 940 /* LPI States start at index 3 */ 941 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 942 union acpi_object *element, *pkg_elem, *obj; 943 944 element = &lpi_data->package.elements[loop]; 945 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 946 continue; 947 948 pkg_elem = element->package.elements; 949 950 obj = pkg_elem + 6; 951 if (obj->type == ACPI_TYPE_BUFFER) { 952 struct acpi_power_register *reg; 953 954 reg = (struct acpi_power_register *)obj->buffer.pointer; 955 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 956 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 957 continue; 958 959 lpi_state->address = reg->address; 960 lpi_state->entry_method = 961 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 962 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 963 } else if (obj->type == ACPI_TYPE_INTEGER) { 964 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 965 lpi_state->address = obj->integer.value; 966 } else { 967 continue; 968 } 969 970 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 971 972 obj = pkg_elem + 9; 973 if (obj->type == ACPI_TYPE_STRING) 974 strscpy(lpi_state->desc, obj->string.pointer, 975 ACPI_CX_DESC_LEN); 976 977 lpi_state->index = state_idx; 978 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 979 pr_debug("No min. residency found, assuming 10 us\n"); 980 lpi_state->min_residency = 10; 981 } 982 983 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 984 pr_debug("No wakeup residency found, assuming 10 us\n"); 985 lpi_state->wake_latency = 10; 986 } 987 988 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 989 lpi_state->flags = 0; 990 991 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 992 lpi_state->arch_flags = 0; 993 994 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 995 lpi_state->res_cnt_freq = 1; 996 997 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 998 lpi_state->enable_parent_state = 0; 999 } 1000 1001 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1002 end: 1003 kfree(buffer.pointer); 1004 return ret; 1005 } 1006 1007 /* 1008 * flat_state_cnt - the number of composite LPI states after the process of flattening 1009 */ 1010 static int flat_state_cnt; 1011 1012 /** 1013 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1014 * 1015 * @local: local LPI state 1016 * @parent: parent LPI state 1017 * @result: composite LPI state 1018 */ 1019 static bool combine_lpi_states(struct acpi_lpi_state *local, 1020 struct acpi_lpi_state *parent, 1021 struct acpi_lpi_state *result) 1022 { 1023 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1024 if (!parent->address) /* 0 means autopromotable */ 1025 return false; 1026 result->address = local->address + parent->address; 1027 } else { 1028 result->address = parent->address; 1029 } 1030 1031 result->min_residency = max(local->min_residency, parent->min_residency); 1032 result->wake_latency = local->wake_latency + parent->wake_latency; 1033 result->enable_parent_state = parent->enable_parent_state; 1034 result->entry_method = local->entry_method; 1035 1036 result->flags = parent->flags; 1037 result->arch_flags = parent->arch_flags; 1038 result->index = parent->index; 1039 1040 strscpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1041 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1042 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1043 return true; 1044 } 1045 1046 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1047 1048 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1049 struct acpi_lpi_state *t) 1050 { 1051 curr_level->composite_states[curr_level->composite_states_size++] = t; 1052 } 1053 1054 static int flatten_lpi_states(struct acpi_processor *pr, 1055 struct acpi_lpi_states_array *curr_level, 1056 struct acpi_lpi_states_array *prev_level) 1057 { 1058 int i, j, state_count = curr_level->size; 1059 struct acpi_lpi_state *p, *t = curr_level->entries; 1060 1061 curr_level->composite_states_size = 0; 1062 for (j = 0; j < state_count; j++, t++) { 1063 struct acpi_lpi_state *flpi; 1064 1065 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1066 continue; 1067 1068 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1069 pr_warn("Limiting number of LPI states to max (%d)\n", 1070 ACPI_PROCESSOR_MAX_POWER); 1071 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1072 break; 1073 } 1074 1075 flpi = &pr->power.lpi_states[flat_state_cnt]; 1076 1077 if (!prev_level) { /* leaf/processor node */ 1078 memcpy(flpi, t, sizeof(*t)); 1079 stash_composite_state(curr_level, flpi); 1080 flat_state_cnt++; 1081 continue; 1082 } 1083 1084 for (i = 0; i < prev_level->composite_states_size; i++) { 1085 p = prev_level->composite_states[i]; 1086 if (t->index <= p->enable_parent_state && 1087 combine_lpi_states(p, t, flpi)) { 1088 stash_composite_state(curr_level, flpi); 1089 flat_state_cnt++; 1090 flpi++; 1091 } 1092 } 1093 } 1094 1095 kfree(curr_level->entries); 1096 return 0; 1097 } 1098 1099 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1100 { 1101 return -EOPNOTSUPP; 1102 } 1103 1104 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1105 { 1106 int ret, i; 1107 acpi_status status; 1108 acpi_handle handle = pr->handle, pr_ahandle; 1109 struct acpi_device *d = NULL; 1110 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1111 1112 /* make sure our architecture has support */ 1113 ret = acpi_processor_ffh_lpi_probe(pr->id); 1114 if (ret == -EOPNOTSUPP) 1115 return ret; 1116 1117 if (!osc_pc_lpi_support_confirmed) 1118 return -EOPNOTSUPP; 1119 1120 if (!acpi_has_method(handle, "_LPI")) 1121 return -EINVAL; 1122 1123 flat_state_cnt = 0; 1124 prev = &info[0]; 1125 curr = &info[1]; 1126 handle = pr->handle; 1127 ret = acpi_processor_evaluate_lpi(handle, prev); 1128 if (ret) 1129 return ret; 1130 flatten_lpi_states(pr, prev, NULL); 1131 1132 status = acpi_get_parent(handle, &pr_ahandle); 1133 while (ACPI_SUCCESS(status)) { 1134 d = acpi_fetch_acpi_dev(pr_ahandle); 1135 if (!d) 1136 break; 1137 1138 handle = pr_ahandle; 1139 1140 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1141 break; 1142 1143 /* can be optional ? */ 1144 if (!acpi_has_method(handle, "_LPI")) 1145 break; 1146 1147 ret = acpi_processor_evaluate_lpi(handle, curr); 1148 if (ret) 1149 break; 1150 1151 /* flatten all the LPI states in this level of hierarchy */ 1152 flatten_lpi_states(pr, curr, prev); 1153 1154 tmp = prev, prev = curr, curr = tmp; 1155 1156 status = acpi_get_parent(handle, &pr_ahandle); 1157 } 1158 1159 pr->power.count = flat_state_cnt; 1160 /* reset the index after flattening */ 1161 for (i = 0; i < pr->power.count; i++) 1162 pr->power.lpi_states[i].index = i; 1163 1164 /* Tell driver that _LPI is supported. */ 1165 pr->flags.has_lpi = 1; 1166 pr->flags.power = 1; 1167 1168 return 0; 1169 } 1170 1171 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1172 { 1173 return -ENODEV; 1174 } 1175 1176 /** 1177 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1178 * @dev: the target CPU 1179 * @drv: cpuidle driver containing cpuidle state info 1180 * @index: index of target state 1181 * 1182 * Return: 0 for success or negative value for error 1183 */ 1184 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1185 struct cpuidle_driver *drv, int index) 1186 { 1187 struct acpi_processor *pr; 1188 struct acpi_lpi_state *lpi; 1189 1190 pr = __this_cpu_read(processors); 1191 1192 if (unlikely(!pr)) 1193 return -EINVAL; 1194 1195 lpi = &pr->power.lpi_states[index]; 1196 if (lpi->entry_method == ACPI_CSTATE_FFH) 1197 return acpi_processor_ffh_lpi_enter(lpi); 1198 1199 return -EINVAL; 1200 } 1201 1202 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1203 { 1204 int i; 1205 struct acpi_lpi_state *lpi; 1206 struct cpuidle_state *state; 1207 struct cpuidle_driver *drv = &acpi_idle_driver; 1208 1209 if (!pr->flags.has_lpi) 1210 return -EOPNOTSUPP; 1211 1212 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1213 lpi = &pr->power.lpi_states[i]; 1214 1215 state = &drv->states[i]; 1216 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1217 strscpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1218 state->exit_latency = lpi->wake_latency; 1219 state->target_residency = lpi->min_residency; 1220 state->flags |= arch_get_idle_state_flags(lpi->arch_flags); 1221 if (i != 0 && lpi->entry_method == ACPI_CSTATE_FFH) 1222 state->flags |= CPUIDLE_FLAG_RCU_IDLE; 1223 state->enter = acpi_idle_lpi_enter; 1224 drv->safe_state_index = i; 1225 } 1226 1227 drv->state_count = i; 1228 1229 return 0; 1230 } 1231 1232 /** 1233 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1234 * global state data i.e. idle routines 1235 * 1236 * @pr: the ACPI processor 1237 */ 1238 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1239 { 1240 int i; 1241 struct cpuidle_driver *drv = &acpi_idle_driver; 1242 1243 if (!pr->flags.power_setup_done || !pr->flags.power) 1244 return -EINVAL; 1245 1246 drv->safe_state_index = -1; 1247 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1248 drv->states[i].name[0] = '\0'; 1249 drv->states[i].desc[0] = '\0'; 1250 } 1251 1252 if (pr->flags.has_lpi) 1253 return acpi_processor_setup_lpi_states(pr); 1254 1255 return acpi_processor_setup_cstates(pr); 1256 } 1257 1258 /** 1259 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1260 * device i.e. per-cpu data 1261 * 1262 * @pr: the ACPI processor 1263 * @dev : the cpuidle device 1264 */ 1265 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1266 struct cpuidle_device *dev) 1267 { 1268 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1269 return -EINVAL; 1270 1271 dev->cpu = pr->id; 1272 if (pr->flags.has_lpi) 1273 return acpi_processor_ffh_lpi_probe(pr->id); 1274 1275 return acpi_processor_setup_cpuidle_cx(pr, dev); 1276 } 1277 1278 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1279 { 1280 int ret; 1281 1282 ret = acpi_processor_get_lpi_info(pr); 1283 if (ret) 1284 ret = acpi_processor_get_cstate_info(pr); 1285 1286 return ret; 1287 } 1288 1289 int acpi_processor_hotplug(struct acpi_processor *pr) 1290 { 1291 int ret = 0; 1292 struct cpuidle_device *dev; 1293 1294 if (disabled_by_idle_boot_param()) 1295 return 0; 1296 1297 if (!pr->flags.power_setup_done) 1298 return -ENODEV; 1299 1300 dev = per_cpu(acpi_cpuidle_device, pr->id); 1301 cpuidle_pause_and_lock(); 1302 cpuidle_disable_device(dev); 1303 ret = acpi_processor_get_power_info(pr); 1304 if (!ret && pr->flags.power) { 1305 acpi_processor_setup_cpuidle_dev(pr, dev); 1306 ret = cpuidle_enable_device(dev); 1307 } 1308 cpuidle_resume_and_unlock(); 1309 1310 return ret; 1311 } 1312 1313 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1314 { 1315 int cpu; 1316 struct acpi_processor *_pr; 1317 struct cpuidle_device *dev; 1318 1319 if (disabled_by_idle_boot_param()) 1320 return 0; 1321 1322 if (!pr->flags.power_setup_done) 1323 return -ENODEV; 1324 1325 /* 1326 * FIXME: Design the ACPI notification to make it once per 1327 * system instead of once per-cpu. This condition is a hack 1328 * to make the code that updates C-States be called once. 1329 */ 1330 1331 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1332 1333 /* Protect against cpu-hotplug */ 1334 cpus_read_lock(); 1335 cpuidle_pause_and_lock(); 1336 1337 /* Disable all cpuidle devices */ 1338 for_each_online_cpu(cpu) { 1339 _pr = per_cpu(processors, cpu); 1340 if (!_pr || !_pr->flags.power_setup_done) 1341 continue; 1342 dev = per_cpu(acpi_cpuidle_device, cpu); 1343 cpuidle_disable_device(dev); 1344 } 1345 1346 /* Populate Updated C-state information */ 1347 acpi_processor_get_power_info(pr); 1348 acpi_processor_setup_cpuidle_states(pr); 1349 1350 /* Enable all cpuidle devices */ 1351 for_each_online_cpu(cpu) { 1352 _pr = per_cpu(processors, cpu); 1353 if (!_pr || !_pr->flags.power_setup_done) 1354 continue; 1355 acpi_processor_get_power_info(_pr); 1356 if (_pr->flags.power) { 1357 dev = per_cpu(acpi_cpuidle_device, cpu); 1358 acpi_processor_setup_cpuidle_dev(_pr, dev); 1359 cpuidle_enable_device(dev); 1360 } 1361 } 1362 cpuidle_resume_and_unlock(); 1363 cpus_read_unlock(); 1364 } 1365 1366 return 0; 1367 } 1368 1369 static int acpi_processor_registered; 1370 1371 int acpi_processor_power_init(struct acpi_processor *pr) 1372 { 1373 int retval; 1374 struct cpuidle_device *dev; 1375 1376 if (disabled_by_idle_boot_param()) 1377 return 0; 1378 1379 acpi_processor_cstate_first_run_checks(); 1380 1381 if (!acpi_processor_get_power_info(pr)) 1382 pr->flags.power_setup_done = 1; 1383 1384 /* 1385 * Install the idle handler if processor power management is supported. 1386 * Note that we use previously set idle handler will be used on 1387 * platforms that only support C1. 1388 */ 1389 if (pr->flags.power) { 1390 /* Register acpi_idle_driver if not already registered */ 1391 if (!acpi_processor_registered) { 1392 acpi_processor_setup_cpuidle_states(pr); 1393 retval = cpuidle_register_driver(&acpi_idle_driver); 1394 if (retval) 1395 return retval; 1396 pr_debug("%s registered with cpuidle\n", 1397 acpi_idle_driver.name); 1398 } 1399 1400 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1401 if (!dev) 1402 return -ENOMEM; 1403 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1404 1405 acpi_processor_setup_cpuidle_dev(pr, dev); 1406 1407 /* Register per-cpu cpuidle_device. Cpuidle driver 1408 * must already be registered before registering device 1409 */ 1410 retval = cpuidle_register_device(dev); 1411 if (retval) { 1412 if (acpi_processor_registered == 0) 1413 cpuidle_unregister_driver(&acpi_idle_driver); 1414 return retval; 1415 } 1416 acpi_processor_registered++; 1417 } 1418 return 0; 1419 } 1420 1421 int acpi_processor_power_exit(struct acpi_processor *pr) 1422 { 1423 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1424 1425 if (disabled_by_idle_boot_param()) 1426 return 0; 1427 1428 if (pr->flags.power) { 1429 cpuidle_unregister_device(dev); 1430 acpi_processor_registered--; 1431 if (acpi_processor_registered == 0) 1432 cpuidle_unregister_driver(&acpi_idle_driver); 1433 } 1434 1435 pr->flags.power_setup_done = 0; 1436 return 0; 1437 } 1438