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 <acpi/processor.h> 25 26 /* 27 * Include the apic definitions for x86 to have the APIC timer related defines 28 * available also for UP (on SMP it gets magically included via linux/smp.h). 29 * asm/acpi.h is not an option, as it would require more include magic. Also 30 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 31 */ 32 #ifdef CONFIG_X86 33 #include <asm/apic.h> 34 #include <asm/cpu.h> 35 #endif 36 37 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) 38 39 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 40 module_param(max_cstate, uint, 0000); 41 static unsigned int nocst __read_mostly; 42 module_param(nocst, uint, 0000); 43 static int bm_check_disable __read_mostly; 44 module_param(bm_check_disable, uint, 0000); 45 46 static unsigned int latency_factor __read_mostly = 2; 47 module_param(latency_factor, uint, 0644); 48 49 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 50 51 struct cpuidle_driver acpi_idle_driver = { 52 .name = "acpi_idle", 53 .owner = THIS_MODULE, 54 }; 55 56 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 57 static 58 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 59 60 static int disabled_by_idle_boot_param(void) 61 { 62 return boot_option_idle_override == IDLE_POLL || 63 boot_option_idle_override == IDLE_HALT; 64 } 65 66 /* 67 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 68 * For now disable this. Probably a bug somewhere else. 69 * 70 * To skip this limit, boot/load with a large max_cstate limit. 71 */ 72 static int set_max_cstate(const struct dmi_system_id *id) 73 { 74 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 75 return 0; 76 77 pr_notice("%s detected - limiting to C%ld max_cstate." 78 " Override with \"processor.max_cstate=%d\"\n", id->ident, 79 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 80 81 max_cstate = (long)id->driver_data; 82 83 return 0; 84 } 85 86 static const struct dmi_system_id processor_power_dmi_table[] = { 87 { set_max_cstate, "Clevo 5600D", { 88 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 89 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 90 (void *)2}, 91 { set_max_cstate, "Pavilion zv5000", { 92 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 93 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 94 (void *)1}, 95 { set_max_cstate, "Asus L8400B", { 96 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 97 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 98 (void *)1}, 99 {}, 100 }; 101 102 103 /* 104 * Callers should disable interrupts before the call and enable 105 * interrupts after return. 106 */ 107 static void __cpuidle acpi_safe_halt(void) 108 { 109 if (!tif_need_resched()) { 110 safe_halt(); 111 local_irq_disable(); 112 } 113 } 114 115 #ifdef ARCH_APICTIMER_STOPS_ON_C3 116 117 /* 118 * Some BIOS implementations switch to C3 in the published C2 state. 119 * This seems to be a common problem on AMD boxen, but other vendors 120 * are affected too. We pick the most conservative approach: we assume 121 * that the local APIC stops in both C2 and C3. 122 */ 123 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 124 struct acpi_processor_cx *cx) 125 { 126 struct acpi_processor_power *pwr = &pr->power; 127 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 128 129 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 130 return; 131 132 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 133 type = ACPI_STATE_C1; 134 135 /* 136 * Check, if one of the previous states already marked the lapic 137 * unstable 138 */ 139 if (pwr->timer_broadcast_on_state < state) 140 return; 141 142 if (cx->type >= type) 143 pr->power.timer_broadcast_on_state = state; 144 } 145 146 static void __lapic_timer_propagate_broadcast(void *arg) 147 { 148 struct acpi_processor *pr = (struct acpi_processor *) arg; 149 150 if (pr->power.timer_broadcast_on_state < INT_MAX) 151 tick_broadcast_enable(); 152 else 153 tick_broadcast_disable(); 154 } 155 156 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 157 { 158 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 159 (void *)pr, 1); 160 } 161 162 /* Power(C) State timer broadcast control */ 163 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 164 struct acpi_processor_cx *cx) 165 { 166 return cx - pr->power.states >= pr->power.timer_broadcast_on_state; 167 } 168 169 #else 170 171 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 172 struct acpi_processor_cx *cstate) { } 173 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 174 175 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 176 struct acpi_processor_cx *cx) 177 { 178 return false; 179 } 180 181 #endif 182 183 #if defined(CONFIG_X86) 184 static void tsc_check_state(int state) 185 { 186 switch (boot_cpu_data.x86_vendor) { 187 case X86_VENDOR_HYGON: 188 case X86_VENDOR_AMD: 189 case X86_VENDOR_INTEL: 190 case X86_VENDOR_CENTAUR: 191 case X86_VENDOR_ZHAOXIN: 192 /* 193 * AMD Fam10h TSC will tick in all 194 * C/P/S0/S1 states when this bit is set. 195 */ 196 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 197 return; 198 fallthrough; 199 default: 200 /* TSC could halt in idle, so notify users */ 201 if (state > ACPI_STATE_C1) 202 mark_tsc_unstable("TSC halts in idle"); 203 } 204 } 205 #else 206 static void tsc_check_state(int state) { return; } 207 #endif 208 209 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 210 { 211 212 if (!pr->pblk) 213 return -ENODEV; 214 215 /* if info is obtained from pblk/fadt, type equals state */ 216 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 217 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 218 219 #ifndef CONFIG_HOTPLUG_CPU 220 /* 221 * Check for P_LVL2_UP flag before entering C2 and above on 222 * an SMP system. 223 */ 224 if ((num_online_cpus() > 1) && 225 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 226 return -ENODEV; 227 #endif 228 229 /* determine C2 and C3 address from pblk */ 230 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 231 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 232 233 /* determine latencies from FADT */ 234 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 235 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 236 237 /* 238 * FADT specified C2 latency must be less than or equal to 239 * 100 microseconds. 240 */ 241 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 242 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n", 243 acpi_gbl_FADT.c2_latency); 244 /* invalidate C2 */ 245 pr->power.states[ACPI_STATE_C2].address = 0; 246 } 247 248 /* 249 * FADT supplied C3 latency must be less than or equal to 250 * 1000 microseconds. 251 */ 252 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 253 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n", 254 acpi_gbl_FADT.c3_latency); 255 /* invalidate C3 */ 256 pr->power.states[ACPI_STATE_C3].address = 0; 257 } 258 259 acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n", 260 pr->power.states[ACPI_STATE_C2].address, 261 pr->power.states[ACPI_STATE_C3].address); 262 263 snprintf(pr->power.states[ACPI_STATE_C2].desc, 264 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x", 265 pr->power.states[ACPI_STATE_C2].address); 266 snprintf(pr->power.states[ACPI_STATE_C3].desc, 267 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x", 268 pr->power.states[ACPI_STATE_C3].address); 269 270 return 0; 271 } 272 273 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 274 { 275 if (!pr->power.states[ACPI_STATE_C1].valid) { 276 /* set the first C-State to C1 */ 277 /* all processors need to support C1 */ 278 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 279 pr->power.states[ACPI_STATE_C1].valid = 1; 280 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 281 282 snprintf(pr->power.states[ACPI_STATE_C1].desc, 283 ACPI_CX_DESC_LEN, "ACPI HLT"); 284 } 285 /* the C0 state only exists as a filler in our array */ 286 pr->power.states[ACPI_STATE_C0].valid = 1; 287 return 0; 288 } 289 290 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 291 { 292 int ret; 293 294 if (nocst) 295 return -ENODEV; 296 297 ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power); 298 if (ret) 299 return ret; 300 301 if (!pr->power.count) 302 return -EFAULT; 303 304 pr->flags.has_cst = 1; 305 return 0; 306 } 307 308 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 309 struct acpi_processor_cx *cx) 310 { 311 static int bm_check_flag = -1; 312 static int bm_control_flag = -1; 313 314 315 if (!cx->address) 316 return; 317 318 /* 319 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 320 * DMA transfers are used by any ISA device to avoid livelock. 321 * Note that we could disable Type-F DMA (as recommended by 322 * the erratum), but this is known to disrupt certain ISA 323 * devices thus we take the conservative approach. 324 */ 325 else if (errata.piix4.fdma) { 326 acpi_handle_debug(pr->handle, 327 "C3 not supported on PIIX4 with Type-F DMA\n"); 328 return; 329 } 330 331 /* All the logic here assumes flags.bm_check is same across all CPUs */ 332 if (bm_check_flag == -1) { 333 /* Determine whether bm_check is needed based on CPU */ 334 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 335 bm_check_flag = pr->flags.bm_check; 336 bm_control_flag = pr->flags.bm_control; 337 } else { 338 pr->flags.bm_check = bm_check_flag; 339 pr->flags.bm_control = bm_control_flag; 340 } 341 342 if (pr->flags.bm_check) { 343 if (!pr->flags.bm_control) { 344 if (pr->flags.has_cst != 1) { 345 /* bus mastering control is necessary */ 346 acpi_handle_debug(pr->handle, 347 "C3 support requires BM control\n"); 348 return; 349 } else { 350 /* Here we enter C3 without bus mastering */ 351 acpi_handle_debug(pr->handle, 352 "C3 support without BM control\n"); 353 } 354 } 355 } else { 356 /* 357 * WBINVD should be set in fadt, for C3 state to be 358 * supported on when bm_check is not required. 359 */ 360 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 361 acpi_handle_debug(pr->handle, 362 "Cache invalidation should work properly" 363 " for C3 to be enabled on SMP systems\n"); 364 return; 365 } 366 } 367 368 /* 369 * Otherwise we've met all of our C3 requirements. 370 * Normalize the C3 latency to expidite policy. Enable 371 * checking of bus mastering status (bm_check) so we can 372 * use this in our C3 policy 373 */ 374 cx->valid = 1; 375 376 /* 377 * On older chipsets, BM_RLD needs to be set 378 * in order for Bus Master activity to wake the 379 * system from C3. Newer chipsets handle DMA 380 * during C3 automatically and BM_RLD is a NOP. 381 * In either case, the proper way to 382 * handle BM_RLD is to set it and leave it set. 383 */ 384 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 385 386 return; 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 void wait_for_freeze(void) 527 { 528 #ifdef CONFIG_X86 529 /* No delay is needed if we are in guest */ 530 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) 531 return; 532 #endif 533 /* Dummy wait op - must do something useless after P_LVL2 read 534 because chipsets cannot guarantee that STPCLK# signal 535 gets asserted in time to freeze execution properly. */ 536 inl(acpi_gbl_FADT.xpm_timer_block.address); 537 } 538 539 /** 540 * acpi_idle_do_entry - enter idle state using the appropriate method 541 * @cx: cstate data 542 * 543 * Caller disables interrupt before call and enables interrupt after return. 544 */ 545 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 546 { 547 if (cx->entry_method == ACPI_CSTATE_FFH) { 548 /* Call into architectural FFH based C-state */ 549 acpi_processor_ffh_cstate_enter(cx); 550 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 551 acpi_safe_halt(); 552 } else { 553 /* IO port based C-state */ 554 inb(cx->address); 555 wait_for_freeze(); 556 } 557 } 558 559 /** 560 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 561 * @dev: the target CPU 562 * @index: the index of suggested state 563 */ 564 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 565 { 566 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 567 568 ACPI_FLUSH_CPU_CACHE(); 569 570 while (1) { 571 572 if (cx->entry_method == ACPI_CSTATE_HALT) 573 safe_halt(); 574 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 575 inb(cx->address); 576 wait_for_freeze(); 577 } else 578 return -ENODEV; 579 580 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU) 581 cond_wakeup_cpu0(); 582 #endif 583 } 584 585 /* Never reached */ 586 return 0; 587 } 588 589 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 590 { 591 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 592 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 593 } 594 595 static int c3_cpu_count; 596 static DEFINE_RAW_SPINLOCK(c3_lock); 597 598 /** 599 * acpi_idle_enter_bm - enters C3 with proper BM handling 600 * @drv: cpuidle driver 601 * @pr: Target processor 602 * @cx: Target state context 603 * @index: index of target state 604 */ 605 static int acpi_idle_enter_bm(struct cpuidle_driver *drv, 606 struct acpi_processor *pr, 607 struct acpi_processor_cx *cx, 608 int index) 609 { 610 static struct acpi_processor_cx safe_cx = { 611 .entry_method = ACPI_CSTATE_HALT, 612 }; 613 614 /* 615 * disable bus master 616 * bm_check implies we need ARB_DIS 617 * bm_control implies whether we can do ARB_DIS 618 * 619 * That leaves a case where bm_check is set and bm_control is not set. 620 * In that case we cannot do much, we enter C3 without doing anything. 621 */ 622 bool dis_bm = pr->flags.bm_control; 623 624 /* If we can skip BM, demote to a safe state. */ 625 if (!cx->bm_sts_skip && acpi_idle_bm_check()) { 626 dis_bm = false; 627 index = drv->safe_state_index; 628 if (index >= 0) { 629 cx = this_cpu_read(acpi_cstate[index]); 630 } else { 631 cx = &safe_cx; 632 index = -EBUSY; 633 } 634 } 635 636 if (dis_bm) { 637 raw_spin_lock(&c3_lock); 638 c3_cpu_count++; 639 /* Disable bus master arbitration when all CPUs are in C3 */ 640 if (c3_cpu_count == num_online_cpus()) 641 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 642 raw_spin_unlock(&c3_lock); 643 } 644 645 rcu_idle_enter(); 646 647 acpi_idle_do_entry(cx); 648 649 rcu_idle_exit(); 650 651 /* Re-enable bus master arbitration */ 652 if (dis_bm) { 653 raw_spin_lock(&c3_lock); 654 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 655 c3_cpu_count--; 656 raw_spin_unlock(&c3_lock); 657 } 658 659 return index; 660 } 661 662 static int acpi_idle_enter(struct cpuidle_device *dev, 663 struct cpuidle_driver *drv, int index) 664 { 665 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 666 struct acpi_processor *pr; 667 668 pr = __this_cpu_read(processors); 669 if (unlikely(!pr)) 670 return -EINVAL; 671 672 if (cx->type != ACPI_STATE_C1) { 673 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) 674 return acpi_idle_enter_bm(drv, pr, cx, index); 675 676 /* C2 to C1 demotion. */ 677 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 678 index = ACPI_IDLE_STATE_START; 679 cx = per_cpu(acpi_cstate[index], dev->cpu); 680 } 681 } 682 683 if (cx->type == ACPI_STATE_C3) 684 ACPI_FLUSH_CPU_CACHE(); 685 686 acpi_idle_do_entry(cx); 687 688 return index; 689 } 690 691 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, 692 struct cpuidle_driver *drv, int index) 693 { 694 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 695 696 if (cx->type == ACPI_STATE_C3) { 697 struct acpi_processor *pr = __this_cpu_read(processors); 698 699 if (unlikely(!pr)) 700 return 0; 701 702 if (pr->flags.bm_check) { 703 u8 bm_sts_skip = cx->bm_sts_skip; 704 705 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */ 706 cx->bm_sts_skip = 1; 707 acpi_idle_enter_bm(drv, pr, cx, index); 708 cx->bm_sts_skip = bm_sts_skip; 709 710 return 0; 711 } else { 712 ACPI_FLUSH_CPU_CACHE(); 713 } 714 } 715 acpi_idle_do_entry(cx); 716 717 return 0; 718 } 719 720 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 721 struct cpuidle_device *dev) 722 { 723 int i, count = ACPI_IDLE_STATE_START; 724 struct acpi_processor_cx *cx; 725 struct cpuidle_state *state; 726 727 if (max_cstate == 0) 728 max_cstate = 1; 729 730 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 731 state = &acpi_idle_driver.states[count]; 732 cx = &pr->power.states[i]; 733 734 if (!cx->valid) 735 continue; 736 737 per_cpu(acpi_cstate[count], dev->cpu) = cx; 738 739 if (lapic_timer_needs_broadcast(pr, cx)) 740 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 741 742 if (cx->type == ACPI_STATE_C3) { 743 state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; 744 if (pr->flags.bm_check) 745 state->flags |= CPUIDLE_FLAG_RCU_IDLE; 746 } 747 748 count++; 749 if (count == CPUIDLE_STATE_MAX) 750 break; 751 } 752 753 if (!count) 754 return -EINVAL; 755 756 return 0; 757 } 758 759 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 760 { 761 int i, count; 762 struct acpi_processor_cx *cx; 763 struct cpuidle_state *state; 764 struct cpuidle_driver *drv = &acpi_idle_driver; 765 766 if (max_cstate == 0) 767 max_cstate = 1; 768 769 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 770 cpuidle_poll_state_init(drv); 771 count = 1; 772 } else { 773 count = 0; 774 } 775 776 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 777 cx = &pr->power.states[i]; 778 779 if (!cx->valid) 780 continue; 781 782 state = &drv->states[count]; 783 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 784 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 785 state->exit_latency = cx->latency; 786 state->target_residency = cx->latency * latency_factor; 787 state->enter = acpi_idle_enter; 788 789 state->flags = 0; 790 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 || 791 cx->type == ACPI_STATE_C3) { 792 state->enter_dead = acpi_idle_play_dead; 793 if (cx->type != ACPI_STATE_C3) 794 drv->safe_state_index = count; 795 } 796 /* 797 * Halt-induced C1 is not good for ->enter_s2idle, because it 798 * re-enables interrupts on exit. Moreover, C1 is generally not 799 * particularly interesting from the suspend-to-idle angle, so 800 * avoid C1 and the situations in which we may need to fall back 801 * to it altogether. 802 */ 803 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 804 state->enter_s2idle = acpi_idle_enter_s2idle; 805 806 count++; 807 if (count == CPUIDLE_STATE_MAX) 808 break; 809 } 810 811 drv->state_count = count; 812 813 if (!count) 814 return -EINVAL; 815 816 return 0; 817 } 818 819 static inline void acpi_processor_cstate_first_run_checks(void) 820 { 821 static int first_run; 822 823 if (first_run) 824 return; 825 dmi_check_system(processor_power_dmi_table); 826 max_cstate = acpi_processor_cstate_check(max_cstate); 827 if (max_cstate < ACPI_C_STATES_MAX) 828 pr_notice("processor limited to max C-state %d\n", max_cstate); 829 830 first_run++; 831 832 if (nocst) 833 return; 834 835 acpi_processor_claim_cst_control(); 836 } 837 #else 838 839 static inline int disabled_by_idle_boot_param(void) { return 0; } 840 static inline void acpi_processor_cstate_first_run_checks(void) { } 841 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 842 { 843 return -ENODEV; 844 } 845 846 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 847 struct cpuidle_device *dev) 848 { 849 return -EINVAL; 850 } 851 852 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 853 { 854 return -EINVAL; 855 } 856 857 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 858 859 struct acpi_lpi_states_array { 860 unsigned int size; 861 unsigned int composite_states_size; 862 struct acpi_lpi_state *entries; 863 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 864 }; 865 866 static int obj_get_integer(union acpi_object *obj, u32 *value) 867 { 868 if (obj->type != ACPI_TYPE_INTEGER) 869 return -EINVAL; 870 871 *value = obj->integer.value; 872 return 0; 873 } 874 875 static int acpi_processor_evaluate_lpi(acpi_handle handle, 876 struct acpi_lpi_states_array *info) 877 { 878 acpi_status status; 879 int ret = 0; 880 int pkg_count, state_idx = 1, loop; 881 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 882 union acpi_object *lpi_data; 883 struct acpi_lpi_state *lpi_state; 884 885 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 886 if (ACPI_FAILURE(status)) { 887 acpi_handle_debug(handle, "No _LPI, giving up\n"); 888 return -ENODEV; 889 } 890 891 lpi_data = buffer.pointer; 892 893 /* There must be at least 4 elements = 3 elements + 1 package */ 894 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 895 lpi_data->package.count < 4) { 896 pr_debug("not enough elements in _LPI\n"); 897 ret = -ENODATA; 898 goto end; 899 } 900 901 pkg_count = lpi_data->package.elements[2].integer.value; 902 903 /* Validate number of power states. */ 904 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 905 pr_debug("count given by _LPI is not valid\n"); 906 ret = -ENODATA; 907 goto end; 908 } 909 910 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 911 if (!lpi_state) { 912 ret = -ENOMEM; 913 goto end; 914 } 915 916 info->size = pkg_count; 917 info->entries = lpi_state; 918 919 /* LPI States start at index 3 */ 920 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 921 union acpi_object *element, *pkg_elem, *obj; 922 923 element = &lpi_data->package.elements[loop]; 924 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 925 continue; 926 927 pkg_elem = element->package.elements; 928 929 obj = pkg_elem + 6; 930 if (obj->type == ACPI_TYPE_BUFFER) { 931 struct acpi_power_register *reg; 932 933 reg = (struct acpi_power_register *)obj->buffer.pointer; 934 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 935 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 936 continue; 937 938 lpi_state->address = reg->address; 939 lpi_state->entry_method = 940 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 941 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 942 } else if (obj->type == ACPI_TYPE_INTEGER) { 943 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 944 lpi_state->address = obj->integer.value; 945 } else { 946 continue; 947 } 948 949 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 950 951 obj = pkg_elem + 9; 952 if (obj->type == ACPI_TYPE_STRING) 953 strlcpy(lpi_state->desc, obj->string.pointer, 954 ACPI_CX_DESC_LEN); 955 956 lpi_state->index = state_idx; 957 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 958 pr_debug("No min. residency found, assuming 10 us\n"); 959 lpi_state->min_residency = 10; 960 } 961 962 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 963 pr_debug("No wakeup residency found, assuming 10 us\n"); 964 lpi_state->wake_latency = 10; 965 } 966 967 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 968 lpi_state->flags = 0; 969 970 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 971 lpi_state->arch_flags = 0; 972 973 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 974 lpi_state->res_cnt_freq = 1; 975 976 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 977 lpi_state->enable_parent_state = 0; 978 } 979 980 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 981 end: 982 kfree(buffer.pointer); 983 return ret; 984 } 985 986 /* 987 * flat_state_cnt - the number of composite LPI states after the process of flattening 988 */ 989 static int flat_state_cnt; 990 991 /** 992 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 993 * 994 * @local: local LPI state 995 * @parent: parent LPI state 996 * @result: composite LPI state 997 */ 998 static bool combine_lpi_states(struct acpi_lpi_state *local, 999 struct acpi_lpi_state *parent, 1000 struct acpi_lpi_state *result) 1001 { 1002 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1003 if (!parent->address) /* 0 means autopromotable */ 1004 return false; 1005 result->address = local->address + parent->address; 1006 } else { 1007 result->address = parent->address; 1008 } 1009 1010 result->min_residency = max(local->min_residency, parent->min_residency); 1011 result->wake_latency = local->wake_latency + parent->wake_latency; 1012 result->enable_parent_state = parent->enable_parent_state; 1013 result->entry_method = local->entry_method; 1014 1015 result->flags = parent->flags; 1016 result->arch_flags = parent->arch_flags; 1017 result->index = parent->index; 1018 1019 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1020 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1021 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1022 return true; 1023 } 1024 1025 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1026 1027 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1028 struct acpi_lpi_state *t) 1029 { 1030 curr_level->composite_states[curr_level->composite_states_size++] = t; 1031 } 1032 1033 static int flatten_lpi_states(struct acpi_processor *pr, 1034 struct acpi_lpi_states_array *curr_level, 1035 struct acpi_lpi_states_array *prev_level) 1036 { 1037 int i, j, state_count = curr_level->size; 1038 struct acpi_lpi_state *p, *t = curr_level->entries; 1039 1040 curr_level->composite_states_size = 0; 1041 for (j = 0; j < state_count; j++, t++) { 1042 struct acpi_lpi_state *flpi; 1043 1044 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1045 continue; 1046 1047 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1048 pr_warn("Limiting number of LPI states to max (%d)\n", 1049 ACPI_PROCESSOR_MAX_POWER); 1050 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1051 break; 1052 } 1053 1054 flpi = &pr->power.lpi_states[flat_state_cnt]; 1055 1056 if (!prev_level) { /* leaf/processor node */ 1057 memcpy(flpi, t, sizeof(*t)); 1058 stash_composite_state(curr_level, flpi); 1059 flat_state_cnt++; 1060 continue; 1061 } 1062 1063 for (i = 0; i < prev_level->composite_states_size; i++) { 1064 p = prev_level->composite_states[i]; 1065 if (t->index <= p->enable_parent_state && 1066 combine_lpi_states(p, t, flpi)) { 1067 stash_composite_state(curr_level, flpi); 1068 flat_state_cnt++; 1069 flpi++; 1070 } 1071 } 1072 } 1073 1074 kfree(curr_level->entries); 1075 return 0; 1076 } 1077 1078 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1079 { 1080 return -EOPNOTSUPP; 1081 } 1082 1083 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1084 { 1085 int ret, i; 1086 acpi_status status; 1087 acpi_handle handle = pr->handle, pr_ahandle; 1088 struct acpi_device *d = NULL; 1089 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1090 1091 /* make sure our architecture has support */ 1092 ret = acpi_processor_ffh_lpi_probe(pr->id); 1093 if (ret == -EOPNOTSUPP) 1094 return ret; 1095 1096 if (!osc_pc_lpi_support_confirmed) 1097 return -EOPNOTSUPP; 1098 1099 if (!acpi_has_method(handle, "_LPI")) 1100 return -EINVAL; 1101 1102 flat_state_cnt = 0; 1103 prev = &info[0]; 1104 curr = &info[1]; 1105 handle = pr->handle; 1106 ret = acpi_processor_evaluate_lpi(handle, prev); 1107 if (ret) 1108 return ret; 1109 flatten_lpi_states(pr, prev, NULL); 1110 1111 status = acpi_get_parent(handle, &pr_ahandle); 1112 while (ACPI_SUCCESS(status)) { 1113 d = acpi_fetch_acpi_dev(pr_ahandle); 1114 handle = pr_ahandle; 1115 1116 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1117 break; 1118 1119 /* can be optional ? */ 1120 if (!acpi_has_method(handle, "_LPI")) 1121 break; 1122 1123 ret = acpi_processor_evaluate_lpi(handle, curr); 1124 if (ret) 1125 break; 1126 1127 /* flatten all the LPI states in this level of hierarchy */ 1128 flatten_lpi_states(pr, curr, prev); 1129 1130 tmp = prev, prev = curr, curr = tmp; 1131 1132 status = acpi_get_parent(handle, &pr_ahandle); 1133 } 1134 1135 pr->power.count = flat_state_cnt; 1136 /* reset the index after flattening */ 1137 for (i = 0; i < pr->power.count; i++) 1138 pr->power.lpi_states[i].index = i; 1139 1140 /* Tell driver that _LPI is supported. */ 1141 pr->flags.has_lpi = 1; 1142 pr->flags.power = 1; 1143 1144 return 0; 1145 } 1146 1147 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1148 { 1149 return -ENODEV; 1150 } 1151 1152 /** 1153 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1154 * @dev: the target CPU 1155 * @drv: cpuidle driver containing cpuidle state info 1156 * @index: index of target state 1157 * 1158 * Return: 0 for success or negative value for error 1159 */ 1160 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1161 struct cpuidle_driver *drv, int index) 1162 { 1163 struct acpi_processor *pr; 1164 struct acpi_lpi_state *lpi; 1165 1166 pr = __this_cpu_read(processors); 1167 1168 if (unlikely(!pr)) 1169 return -EINVAL; 1170 1171 lpi = &pr->power.lpi_states[index]; 1172 if (lpi->entry_method == ACPI_CSTATE_FFH) 1173 return acpi_processor_ffh_lpi_enter(lpi); 1174 1175 return -EINVAL; 1176 } 1177 1178 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1179 { 1180 int i; 1181 struct acpi_lpi_state *lpi; 1182 struct cpuidle_state *state; 1183 struct cpuidle_driver *drv = &acpi_idle_driver; 1184 1185 if (!pr->flags.has_lpi) 1186 return -EOPNOTSUPP; 1187 1188 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1189 lpi = &pr->power.lpi_states[i]; 1190 1191 state = &drv->states[i]; 1192 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1193 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1194 state->exit_latency = lpi->wake_latency; 1195 state->target_residency = lpi->min_residency; 1196 if (lpi->arch_flags) 1197 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1198 state->enter = acpi_idle_lpi_enter; 1199 drv->safe_state_index = i; 1200 } 1201 1202 drv->state_count = i; 1203 1204 return 0; 1205 } 1206 1207 /** 1208 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1209 * global state data i.e. idle routines 1210 * 1211 * @pr: the ACPI processor 1212 */ 1213 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1214 { 1215 int i; 1216 struct cpuidle_driver *drv = &acpi_idle_driver; 1217 1218 if (!pr->flags.power_setup_done || !pr->flags.power) 1219 return -EINVAL; 1220 1221 drv->safe_state_index = -1; 1222 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1223 drv->states[i].name[0] = '\0'; 1224 drv->states[i].desc[0] = '\0'; 1225 } 1226 1227 if (pr->flags.has_lpi) 1228 return acpi_processor_setup_lpi_states(pr); 1229 1230 return acpi_processor_setup_cstates(pr); 1231 } 1232 1233 /** 1234 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1235 * device i.e. per-cpu data 1236 * 1237 * @pr: the ACPI processor 1238 * @dev : the cpuidle device 1239 */ 1240 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1241 struct cpuidle_device *dev) 1242 { 1243 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1244 return -EINVAL; 1245 1246 dev->cpu = pr->id; 1247 if (pr->flags.has_lpi) 1248 return acpi_processor_ffh_lpi_probe(pr->id); 1249 1250 return acpi_processor_setup_cpuidle_cx(pr, dev); 1251 } 1252 1253 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1254 { 1255 int ret; 1256 1257 ret = acpi_processor_get_lpi_info(pr); 1258 if (ret) 1259 ret = acpi_processor_get_cstate_info(pr); 1260 1261 return ret; 1262 } 1263 1264 int acpi_processor_hotplug(struct acpi_processor *pr) 1265 { 1266 int ret = 0; 1267 struct cpuidle_device *dev; 1268 1269 if (disabled_by_idle_boot_param()) 1270 return 0; 1271 1272 if (!pr->flags.power_setup_done) 1273 return -ENODEV; 1274 1275 dev = per_cpu(acpi_cpuidle_device, pr->id); 1276 cpuidle_pause_and_lock(); 1277 cpuidle_disable_device(dev); 1278 ret = acpi_processor_get_power_info(pr); 1279 if (!ret && pr->flags.power) { 1280 acpi_processor_setup_cpuidle_dev(pr, dev); 1281 ret = cpuidle_enable_device(dev); 1282 } 1283 cpuidle_resume_and_unlock(); 1284 1285 return ret; 1286 } 1287 1288 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1289 { 1290 int cpu; 1291 struct acpi_processor *_pr; 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 /* 1301 * FIXME: Design the ACPI notification to make it once per 1302 * system instead of once per-cpu. This condition is a hack 1303 * to make the code that updates C-States be called once. 1304 */ 1305 1306 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1307 1308 /* Protect against cpu-hotplug */ 1309 cpus_read_lock(); 1310 cpuidle_pause_and_lock(); 1311 1312 /* Disable all cpuidle devices */ 1313 for_each_online_cpu(cpu) { 1314 _pr = per_cpu(processors, cpu); 1315 if (!_pr || !_pr->flags.power_setup_done) 1316 continue; 1317 dev = per_cpu(acpi_cpuidle_device, cpu); 1318 cpuidle_disable_device(dev); 1319 } 1320 1321 /* Populate Updated C-state information */ 1322 acpi_processor_get_power_info(pr); 1323 acpi_processor_setup_cpuidle_states(pr); 1324 1325 /* Enable all cpuidle devices */ 1326 for_each_online_cpu(cpu) { 1327 _pr = per_cpu(processors, cpu); 1328 if (!_pr || !_pr->flags.power_setup_done) 1329 continue; 1330 acpi_processor_get_power_info(_pr); 1331 if (_pr->flags.power) { 1332 dev = per_cpu(acpi_cpuidle_device, cpu); 1333 acpi_processor_setup_cpuidle_dev(_pr, dev); 1334 cpuidle_enable_device(dev); 1335 } 1336 } 1337 cpuidle_resume_and_unlock(); 1338 cpus_read_unlock(); 1339 } 1340 1341 return 0; 1342 } 1343 1344 static int acpi_processor_registered; 1345 1346 int acpi_processor_power_init(struct acpi_processor *pr) 1347 { 1348 int retval; 1349 struct cpuidle_device *dev; 1350 1351 if (disabled_by_idle_boot_param()) 1352 return 0; 1353 1354 acpi_processor_cstate_first_run_checks(); 1355 1356 if (!acpi_processor_get_power_info(pr)) 1357 pr->flags.power_setup_done = 1; 1358 1359 /* 1360 * Install the idle handler if processor power management is supported. 1361 * Note that we use previously set idle handler will be used on 1362 * platforms that only support C1. 1363 */ 1364 if (pr->flags.power) { 1365 /* Register acpi_idle_driver if not already registered */ 1366 if (!acpi_processor_registered) { 1367 acpi_processor_setup_cpuidle_states(pr); 1368 retval = cpuidle_register_driver(&acpi_idle_driver); 1369 if (retval) 1370 return retval; 1371 pr_debug("%s registered with cpuidle\n", 1372 acpi_idle_driver.name); 1373 } 1374 1375 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1376 if (!dev) 1377 return -ENOMEM; 1378 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1379 1380 acpi_processor_setup_cpuidle_dev(pr, dev); 1381 1382 /* Register per-cpu cpuidle_device. Cpuidle driver 1383 * must already be registered before registering device 1384 */ 1385 retval = cpuidle_register_device(dev); 1386 if (retval) { 1387 if (acpi_processor_registered == 0) 1388 cpuidle_unregister_driver(&acpi_idle_driver); 1389 return retval; 1390 } 1391 acpi_processor_registered++; 1392 } 1393 return 0; 1394 } 1395 1396 int acpi_processor_power_exit(struct acpi_processor *pr) 1397 { 1398 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1399 1400 if (disabled_by_idle_boot_param()) 1401 return 0; 1402 1403 if (pr->flags.power) { 1404 cpuidle_unregister_device(dev); 1405 acpi_processor_registered--; 1406 if (acpi_processor_registered == 0) 1407 cpuidle_unregister_driver(&acpi_idle_driver); 1408 } 1409 1410 pr->flags.power_setup_done = 0; 1411 return 0; 1412 } 1413