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 /* T40 can not handle C3 idle state */ 100 { set_max_cstate, "IBM ThinkPad T40", { 101 DMI_MATCH(DMI_SYS_VENDOR, "IBM"), 102 DMI_MATCH(DMI_PRODUCT_NAME, "23737CU")}, 103 (void *)2}, 104 {}, 105 }; 106 107 108 /* 109 * Callers should disable interrupts before the call and enable 110 * interrupts after return. 111 */ 112 static void __cpuidle acpi_safe_halt(void) 113 { 114 if (!tif_need_resched()) { 115 safe_halt(); 116 local_irq_disable(); 117 } 118 } 119 120 #ifdef ARCH_APICTIMER_STOPS_ON_C3 121 122 /* 123 * Some BIOS implementations switch to C3 in the published C2 state. 124 * This seems to be a common problem on AMD boxen, but other vendors 125 * are affected too. We pick the most conservative approach: we assume 126 * that the local APIC stops in both C2 and C3. 127 */ 128 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 129 struct acpi_processor_cx *cx) 130 { 131 struct acpi_processor_power *pwr = &pr->power; 132 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 133 134 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 135 return; 136 137 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 138 type = ACPI_STATE_C1; 139 140 /* 141 * Check, if one of the previous states already marked the lapic 142 * unstable 143 */ 144 if (pwr->timer_broadcast_on_state < state) 145 return; 146 147 if (cx->type >= type) 148 pr->power.timer_broadcast_on_state = state; 149 } 150 151 static void __lapic_timer_propagate_broadcast(void *arg) 152 { 153 struct acpi_processor *pr = (struct acpi_processor *) arg; 154 155 if (pr->power.timer_broadcast_on_state < INT_MAX) 156 tick_broadcast_enable(); 157 else 158 tick_broadcast_disable(); 159 } 160 161 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 162 { 163 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 164 (void *)pr, 1); 165 } 166 167 /* Power(C) State timer broadcast control */ 168 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 169 struct acpi_processor_cx *cx) 170 { 171 return cx - pr->power.states >= pr->power.timer_broadcast_on_state; 172 } 173 174 #else 175 176 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 177 struct acpi_processor_cx *cstate) { } 178 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 179 180 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr, 181 struct acpi_processor_cx *cx) 182 { 183 return false; 184 } 185 186 #endif 187 188 #if defined(CONFIG_X86) 189 static void tsc_check_state(int state) 190 { 191 switch (boot_cpu_data.x86_vendor) { 192 case X86_VENDOR_HYGON: 193 case X86_VENDOR_AMD: 194 case X86_VENDOR_INTEL: 195 case X86_VENDOR_CENTAUR: 196 case X86_VENDOR_ZHAOXIN: 197 /* 198 * AMD Fam10h TSC will tick in all 199 * C/P/S0/S1 states when this bit is set. 200 */ 201 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 202 return; 203 fallthrough; 204 default: 205 /* TSC could halt in idle, so notify users */ 206 if (state > ACPI_STATE_C1) 207 mark_tsc_unstable("TSC halts in idle"); 208 } 209 } 210 #else 211 static void tsc_check_state(int state) { return; } 212 #endif 213 214 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 215 { 216 217 if (!pr->pblk) 218 return -ENODEV; 219 220 /* if info is obtained from pblk/fadt, type equals state */ 221 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 222 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 223 224 #ifndef CONFIG_HOTPLUG_CPU 225 /* 226 * Check for P_LVL2_UP flag before entering C2 and above on 227 * an SMP system. 228 */ 229 if ((num_online_cpus() > 1) && 230 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 231 return -ENODEV; 232 #endif 233 234 /* determine C2 and C3 address from pblk */ 235 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 236 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 237 238 /* determine latencies from FADT */ 239 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 240 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 241 242 /* 243 * FADT specified C2 latency must be less than or equal to 244 * 100 microseconds. 245 */ 246 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 247 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n", 248 acpi_gbl_FADT.c2_latency); 249 /* invalidate C2 */ 250 pr->power.states[ACPI_STATE_C2].address = 0; 251 } 252 253 /* 254 * FADT supplied C3 latency must be less than or equal to 255 * 1000 microseconds. 256 */ 257 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 258 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n", 259 acpi_gbl_FADT.c3_latency); 260 /* invalidate C3 */ 261 pr->power.states[ACPI_STATE_C3].address = 0; 262 } 263 264 acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n", 265 pr->power.states[ACPI_STATE_C2].address, 266 pr->power.states[ACPI_STATE_C3].address); 267 268 snprintf(pr->power.states[ACPI_STATE_C2].desc, 269 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x", 270 pr->power.states[ACPI_STATE_C2].address); 271 snprintf(pr->power.states[ACPI_STATE_C3].desc, 272 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x", 273 pr->power.states[ACPI_STATE_C3].address); 274 275 return 0; 276 } 277 278 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 279 { 280 if (!pr->power.states[ACPI_STATE_C1].valid) { 281 /* set the first C-State to C1 */ 282 /* all processors need to support C1 */ 283 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 284 pr->power.states[ACPI_STATE_C1].valid = 1; 285 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 286 287 snprintf(pr->power.states[ACPI_STATE_C1].desc, 288 ACPI_CX_DESC_LEN, "ACPI HLT"); 289 } 290 /* the C0 state only exists as a filler in our array */ 291 pr->power.states[ACPI_STATE_C0].valid = 1; 292 return 0; 293 } 294 295 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 296 { 297 int ret; 298 299 if (nocst) 300 return -ENODEV; 301 302 ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power); 303 if (ret) 304 return ret; 305 306 if (!pr->power.count) 307 return -EFAULT; 308 309 pr->flags.has_cst = 1; 310 return 0; 311 } 312 313 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 314 struct acpi_processor_cx *cx) 315 { 316 static int bm_check_flag = -1; 317 static int bm_control_flag = -1; 318 319 320 if (!cx->address) 321 return; 322 323 /* 324 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 325 * DMA transfers are used by any ISA device to avoid livelock. 326 * Note that we could disable Type-F DMA (as recommended by 327 * the erratum), but this is known to disrupt certain ISA 328 * devices thus we take the conservative approach. 329 */ 330 else if (errata.piix4.fdma) { 331 acpi_handle_debug(pr->handle, 332 "C3 not supported on PIIX4 with Type-F DMA\n"); 333 return; 334 } 335 336 /* All the logic here assumes flags.bm_check is same across all CPUs */ 337 if (bm_check_flag == -1) { 338 /* Determine whether bm_check is needed based on CPU */ 339 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 340 bm_check_flag = pr->flags.bm_check; 341 bm_control_flag = pr->flags.bm_control; 342 } else { 343 pr->flags.bm_check = bm_check_flag; 344 pr->flags.bm_control = bm_control_flag; 345 } 346 347 if (pr->flags.bm_check) { 348 if (!pr->flags.bm_control) { 349 if (pr->flags.has_cst != 1) { 350 /* bus mastering control is necessary */ 351 acpi_handle_debug(pr->handle, 352 "C3 support requires BM control\n"); 353 return; 354 } else { 355 /* Here we enter C3 without bus mastering */ 356 acpi_handle_debug(pr->handle, 357 "C3 support without BM control\n"); 358 } 359 } 360 } else { 361 /* 362 * WBINVD should be set in fadt, for C3 state to be 363 * supported on when bm_check is not required. 364 */ 365 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 366 acpi_handle_debug(pr->handle, 367 "Cache invalidation should work properly" 368 " for C3 to be enabled on SMP systems\n"); 369 return; 370 } 371 } 372 373 /* 374 * Otherwise we've met all of our C3 requirements. 375 * Normalize the C3 latency to expidite policy. Enable 376 * checking of bus mastering status (bm_check) so we can 377 * use this in our C3 policy 378 */ 379 cx->valid = 1; 380 381 /* 382 * On older chipsets, BM_RLD needs to be set 383 * in order for Bus Master activity to wake the 384 * system from C3. Newer chipsets handle DMA 385 * during C3 automatically and BM_RLD is a NOP. 386 * In either case, the proper way to 387 * handle BM_RLD is to set it and leave it set. 388 */ 389 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 390 391 return; 392 } 393 394 static int acpi_cst_latency_cmp(const void *a, const void *b) 395 { 396 const struct acpi_processor_cx *x = a, *y = b; 397 398 if (!(x->valid && y->valid)) 399 return 0; 400 if (x->latency > y->latency) 401 return 1; 402 if (x->latency < y->latency) 403 return -1; 404 return 0; 405 } 406 static void acpi_cst_latency_swap(void *a, void *b, int n) 407 { 408 struct acpi_processor_cx *x = a, *y = b; 409 410 if (!(x->valid && y->valid)) 411 return; 412 swap(x->latency, y->latency); 413 } 414 415 static int acpi_processor_power_verify(struct acpi_processor *pr) 416 { 417 unsigned int i; 418 unsigned int working = 0; 419 unsigned int last_latency = 0; 420 unsigned int last_type = 0; 421 bool buggy_latency = false; 422 423 pr->power.timer_broadcast_on_state = INT_MAX; 424 425 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 426 struct acpi_processor_cx *cx = &pr->power.states[i]; 427 428 switch (cx->type) { 429 case ACPI_STATE_C1: 430 cx->valid = 1; 431 break; 432 433 case ACPI_STATE_C2: 434 if (!cx->address) 435 break; 436 cx->valid = 1; 437 break; 438 439 case ACPI_STATE_C3: 440 acpi_processor_power_verify_c3(pr, cx); 441 break; 442 } 443 if (!cx->valid) 444 continue; 445 if (cx->type >= last_type && cx->latency < last_latency) 446 buggy_latency = true; 447 last_latency = cx->latency; 448 last_type = cx->type; 449 450 lapic_timer_check_state(i, pr, cx); 451 tsc_check_state(cx->type); 452 working++; 453 } 454 455 if (buggy_latency) { 456 pr_notice("FW issue: working around C-state latencies out of order\n"); 457 sort(&pr->power.states[1], max_cstate, 458 sizeof(struct acpi_processor_cx), 459 acpi_cst_latency_cmp, 460 acpi_cst_latency_swap); 461 } 462 463 lapic_timer_propagate_broadcast(pr); 464 465 return (working); 466 } 467 468 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 469 { 470 unsigned int i; 471 int result; 472 473 474 /* NOTE: the idle thread may not be running while calling 475 * this function */ 476 477 /* Zero initialize all the C-states info. */ 478 memset(pr->power.states, 0, sizeof(pr->power.states)); 479 480 result = acpi_processor_get_power_info_cst(pr); 481 if (result == -ENODEV) 482 result = acpi_processor_get_power_info_fadt(pr); 483 484 if (result) 485 return result; 486 487 acpi_processor_get_power_info_default(pr); 488 489 pr->power.count = acpi_processor_power_verify(pr); 490 491 /* 492 * if one state of type C2 or C3 is available, mark this 493 * CPU as being "idle manageable" 494 */ 495 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 496 if (pr->power.states[i].valid) { 497 pr->power.count = i; 498 pr->flags.power = 1; 499 } 500 } 501 502 return 0; 503 } 504 505 /** 506 * acpi_idle_bm_check - checks if bus master activity was detected 507 */ 508 static int acpi_idle_bm_check(void) 509 { 510 u32 bm_status = 0; 511 512 if (bm_check_disable) 513 return 0; 514 515 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 516 if (bm_status) 517 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 518 /* 519 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 520 * the true state of bus mastering activity; forcing us to 521 * manually check the BMIDEA bit of each IDE channel. 522 */ 523 else if (errata.piix4.bmisx) { 524 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 525 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 526 bm_status = 1; 527 } 528 return bm_status; 529 } 530 531 static void wait_for_freeze(void) 532 { 533 #ifdef CONFIG_X86 534 /* No delay is needed if we are in guest */ 535 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) 536 return; 537 #endif 538 /* Dummy wait op - must do something useless after P_LVL2 read 539 because chipsets cannot guarantee that STPCLK# signal 540 gets asserted in time to freeze execution properly. */ 541 inl(acpi_gbl_FADT.xpm_timer_block.address); 542 } 543 544 /** 545 * acpi_idle_do_entry - enter idle state using the appropriate method 546 * @cx: cstate data 547 * 548 * Caller disables interrupt before call and enables interrupt after return. 549 */ 550 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 551 { 552 if (cx->entry_method == ACPI_CSTATE_FFH) { 553 /* Call into architectural FFH based C-state */ 554 acpi_processor_ffh_cstate_enter(cx); 555 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 556 acpi_safe_halt(); 557 } else { 558 /* IO port based C-state */ 559 inb(cx->address); 560 wait_for_freeze(); 561 } 562 } 563 564 /** 565 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 566 * @dev: the target CPU 567 * @index: the index of suggested state 568 */ 569 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 570 { 571 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 572 573 if (cx->type == ACPI_STATE_C3) 574 ACPI_FLUSH_CPU_CACHE(); 575 576 while (1) { 577 578 if (cx->entry_method == ACPI_CSTATE_HALT) 579 safe_halt(); 580 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 581 inb(cx->address); 582 wait_for_freeze(); 583 } else 584 return -ENODEV; 585 586 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU) 587 cond_wakeup_cpu0(); 588 #endif 589 } 590 591 /* Never reached */ 592 return 0; 593 } 594 595 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 596 { 597 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 598 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 599 } 600 601 static int c3_cpu_count; 602 static DEFINE_RAW_SPINLOCK(c3_lock); 603 604 /** 605 * acpi_idle_enter_bm - enters C3 with proper BM handling 606 * @drv: cpuidle driver 607 * @pr: Target processor 608 * @cx: Target state context 609 * @index: index of target state 610 */ 611 static int acpi_idle_enter_bm(struct cpuidle_driver *drv, 612 struct acpi_processor *pr, 613 struct acpi_processor_cx *cx, 614 int index) 615 { 616 static struct acpi_processor_cx safe_cx = { 617 .entry_method = ACPI_CSTATE_HALT, 618 }; 619 620 /* 621 * disable bus master 622 * bm_check implies we need ARB_DIS 623 * bm_control implies whether we can do ARB_DIS 624 * 625 * That leaves a case where bm_check is set and bm_control is not set. 626 * In that case we cannot do much, we enter C3 without doing anything. 627 */ 628 bool dis_bm = pr->flags.bm_control; 629 630 /* If we can skip BM, demote to a safe state. */ 631 if (!cx->bm_sts_skip && acpi_idle_bm_check()) { 632 dis_bm = false; 633 index = drv->safe_state_index; 634 if (index >= 0) { 635 cx = this_cpu_read(acpi_cstate[index]); 636 } else { 637 cx = &safe_cx; 638 index = -EBUSY; 639 } 640 } 641 642 if (dis_bm) { 643 raw_spin_lock(&c3_lock); 644 c3_cpu_count++; 645 /* Disable bus master arbitration when all CPUs are in C3 */ 646 if (c3_cpu_count == num_online_cpus()) 647 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 648 raw_spin_unlock(&c3_lock); 649 } 650 651 rcu_idle_enter(); 652 653 acpi_idle_do_entry(cx); 654 655 rcu_idle_exit(); 656 657 /* Re-enable bus master arbitration */ 658 if (dis_bm) { 659 raw_spin_lock(&c3_lock); 660 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 661 c3_cpu_count--; 662 raw_spin_unlock(&c3_lock); 663 } 664 665 return index; 666 } 667 668 static int acpi_idle_enter(struct cpuidle_device *dev, 669 struct cpuidle_driver *drv, int index) 670 { 671 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 672 struct acpi_processor *pr; 673 674 pr = __this_cpu_read(processors); 675 if (unlikely(!pr)) 676 return -EINVAL; 677 678 if (cx->type != ACPI_STATE_C1) { 679 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) 680 return acpi_idle_enter_bm(drv, pr, cx, index); 681 682 /* C2 to C1 demotion. */ 683 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 684 index = ACPI_IDLE_STATE_START; 685 cx = per_cpu(acpi_cstate[index], dev->cpu); 686 } 687 } 688 689 if (cx->type == ACPI_STATE_C3) 690 ACPI_FLUSH_CPU_CACHE(); 691 692 acpi_idle_do_entry(cx); 693 694 return index; 695 } 696 697 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, 698 struct cpuidle_driver *drv, int index) 699 { 700 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 701 702 if (cx->type == ACPI_STATE_C3) { 703 struct acpi_processor *pr = __this_cpu_read(processors); 704 705 if (unlikely(!pr)) 706 return 0; 707 708 if (pr->flags.bm_check) { 709 u8 bm_sts_skip = cx->bm_sts_skip; 710 711 /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */ 712 cx->bm_sts_skip = 1; 713 acpi_idle_enter_bm(drv, pr, cx, index); 714 cx->bm_sts_skip = bm_sts_skip; 715 716 return 0; 717 } else { 718 ACPI_FLUSH_CPU_CACHE(); 719 } 720 } 721 acpi_idle_do_entry(cx); 722 723 return 0; 724 } 725 726 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 727 struct cpuidle_device *dev) 728 { 729 int i, count = ACPI_IDLE_STATE_START; 730 struct acpi_processor_cx *cx; 731 struct cpuidle_state *state; 732 733 if (max_cstate == 0) 734 max_cstate = 1; 735 736 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 737 state = &acpi_idle_driver.states[count]; 738 cx = &pr->power.states[i]; 739 740 if (!cx->valid) 741 continue; 742 743 per_cpu(acpi_cstate[count], dev->cpu) = cx; 744 745 if (lapic_timer_needs_broadcast(pr, cx)) 746 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 747 748 if (cx->type == ACPI_STATE_C3) { 749 state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; 750 if (pr->flags.bm_check) 751 state->flags |= CPUIDLE_FLAG_RCU_IDLE; 752 } 753 754 count++; 755 if (count == CPUIDLE_STATE_MAX) 756 break; 757 } 758 759 if (!count) 760 return -EINVAL; 761 762 return 0; 763 } 764 765 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 766 { 767 int i, count; 768 struct acpi_processor_cx *cx; 769 struct cpuidle_state *state; 770 struct cpuidle_driver *drv = &acpi_idle_driver; 771 772 if (max_cstate == 0) 773 max_cstate = 1; 774 775 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 776 cpuidle_poll_state_init(drv); 777 count = 1; 778 } else { 779 count = 0; 780 } 781 782 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 783 cx = &pr->power.states[i]; 784 785 if (!cx->valid) 786 continue; 787 788 state = &drv->states[count]; 789 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 790 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 791 state->exit_latency = cx->latency; 792 state->target_residency = cx->latency * latency_factor; 793 state->enter = acpi_idle_enter; 794 795 state->flags = 0; 796 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 || 797 cx->type == ACPI_STATE_C3) { 798 state->enter_dead = acpi_idle_play_dead; 799 drv->safe_state_index = count; 800 } 801 /* 802 * Halt-induced C1 is not good for ->enter_s2idle, because it 803 * re-enables interrupts on exit. Moreover, C1 is generally not 804 * particularly interesting from the suspend-to-idle angle, so 805 * avoid C1 and the situations in which we may need to fall back 806 * to it altogether. 807 */ 808 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 809 state->enter_s2idle = acpi_idle_enter_s2idle; 810 811 count++; 812 if (count == CPUIDLE_STATE_MAX) 813 break; 814 } 815 816 drv->state_count = count; 817 818 if (!count) 819 return -EINVAL; 820 821 return 0; 822 } 823 824 static inline void acpi_processor_cstate_first_run_checks(void) 825 { 826 static int first_run; 827 828 if (first_run) 829 return; 830 dmi_check_system(processor_power_dmi_table); 831 max_cstate = acpi_processor_cstate_check(max_cstate); 832 if (max_cstate < ACPI_C_STATES_MAX) 833 pr_notice("processor limited to max C-state %d\n", max_cstate); 834 835 first_run++; 836 837 if (nocst) 838 return; 839 840 acpi_processor_claim_cst_control(); 841 } 842 #else 843 844 static inline int disabled_by_idle_boot_param(void) { return 0; } 845 static inline void acpi_processor_cstate_first_run_checks(void) { } 846 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 847 { 848 return -ENODEV; 849 } 850 851 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 852 struct cpuidle_device *dev) 853 { 854 return -EINVAL; 855 } 856 857 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 858 { 859 return -EINVAL; 860 } 861 862 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 863 864 struct acpi_lpi_states_array { 865 unsigned int size; 866 unsigned int composite_states_size; 867 struct acpi_lpi_state *entries; 868 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 869 }; 870 871 static int obj_get_integer(union acpi_object *obj, u32 *value) 872 { 873 if (obj->type != ACPI_TYPE_INTEGER) 874 return -EINVAL; 875 876 *value = obj->integer.value; 877 return 0; 878 } 879 880 static int acpi_processor_evaluate_lpi(acpi_handle handle, 881 struct acpi_lpi_states_array *info) 882 { 883 acpi_status status; 884 int ret = 0; 885 int pkg_count, state_idx = 1, loop; 886 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 887 union acpi_object *lpi_data; 888 struct acpi_lpi_state *lpi_state; 889 890 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 891 if (ACPI_FAILURE(status)) { 892 acpi_handle_debug(handle, "No _LPI, giving up\n"); 893 return -ENODEV; 894 } 895 896 lpi_data = buffer.pointer; 897 898 /* There must be at least 4 elements = 3 elements + 1 package */ 899 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 900 lpi_data->package.count < 4) { 901 pr_debug("not enough elements in _LPI\n"); 902 ret = -ENODATA; 903 goto end; 904 } 905 906 pkg_count = lpi_data->package.elements[2].integer.value; 907 908 /* Validate number of power states. */ 909 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 910 pr_debug("count given by _LPI is not valid\n"); 911 ret = -ENODATA; 912 goto end; 913 } 914 915 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 916 if (!lpi_state) { 917 ret = -ENOMEM; 918 goto end; 919 } 920 921 info->size = pkg_count; 922 info->entries = lpi_state; 923 924 /* LPI States start at index 3 */ 925 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 926 union acpi_object *element, *pkg_elem, *obj; 927 928 element = &lpi_data->package.elements[loop]; 929 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 930 continue; 931 932 pkg_elem = element->package.elements; 933 934 obj = pkg_elem + 6; 935 if (obj->type == ACPI_TYPE_BUFFER) { 936 struct acpi_power_register *reg; 937 938 reg = (struct acpi_power_register *)obj->buffer.pointer; 939 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 940 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 941 continue; 942 943 lpi_state->address = reg->address; 944 lpi_state->entry_method = 945 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 946 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 947 } else if (obj->type == ACPI_TYPE_INTEGER) { 948 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 949 lpi_state->address = obj->integer.value; 950 } else { 951 continue; 952 } 953 954 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 955 956 obj = pkg_elem + 9; 957 if (obj->type == ACPI_TYPE_STRING) 958 strlcpy(lpi_state->desc, obj->string.pointer, 959 ACPI_CX_DESC_LEN); 960 961 lpi_state->index = state_idx; 962 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 963 pr_debug("No min. residency found, assuming 10 us\n"); 964 lpi_state->min_residency = 10; 965 } 966 967 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 968 pr_debug("No wakeup residency found, assuming 10 us\n"); 969 lpi_state->wake_latency = 10; 970 } 971 972 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 973 lpi_state->flags = 0; 974 975 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 976 lpi_state->arch_flags = 0; 977 978 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 979 lpi_state->res_cnt_freq = 1; 980 981 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 982 lpi_state->enable_parent_state = 0; 983 } 984 985 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 986 end: 987 kfree(buffer.pointer); 988 return ret; 989 } 990 991 /* 992 * flat_state_cnt - the number of composite LPI states after the process of flattening 993 */ 994 static int flat_state_cnt; 995 996 /** 997 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 998 * 999 * @local: local LPI state 1000 * @parent: parent LPI state 1001 * @result: composite LPI state 1002 */ 1003 static bool combine_lpi_states(struct acpi_lpi_state *local, 1004 struct acpi_lpi_state *parent, 1005 struct acpi_lpi_state *result) 1006 { 1007 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1008 if (!parent->address) /* 0 means autopromotable */ 1009 return false; 1010 result->address = local->address + parent->address; 1011 } else { 1012 result->address = parent->address; 1013 } 1014 1015 result->min_residency = max(local->min_residency, parent->min_residency); 1016 result->wake_latency = local->wake_latency + parent->wake_latency; 1017 result->enable_parent_state = parent->enable_parent_state; 1018 result->entry_method = local->entry_method; 1019 1020 result->flags = parent->flags; 1021 result->arch_flags = parent->arch_flags; 1022 result->index = parent->index; 1023 1024 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1025 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1026 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1027 return true; 1028 } 1029 1030 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1031 1032 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1033 struct acpi_lpi_state *t) 1034 { 1035 curr_level->composite_states[curr_level->composite_states_size++] = t; 1036 } 1037 1038 static int flatten_lpi_states(struct acpi_processor *pr, 1039 struct acpi_lpi_states_array *curr_level, 1040 struct acpi_lpi_states_array *prev_level) 1041 { 1042 int i, j, state_count = curr_level->size; 1043 struct acpi_lpi_state *p, *t = curr_level->entries; 1044 1045 curr_level->composite_states_size = 0; 1046 for (j = 0; j < state_count; j++, t++) { 1047 struct acpi_lpi_state *flpi; 1048 1049 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1050 continue; 1051 1052 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1053 pr_warn("Limiting number of LPI states to max (%d)\n", 1054 ACPI_PROCESSOR_MAX_POWER); 1055 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1056 break; 1057 } 1058 1059 flpi = &pr->power.lpi_states[flat_state_cnt]; 1060 1061 if (!prev_level) { /* leaf/processor node */ 1062 memcpy(flpi, t, sizeof(*t)); 1063 stash_composite_state(curr_level, flpi); 1064 flat_state_cnt++; 1065 continue; 1066 } 1067 1068 for (i = 0; i < prev_level->composite_states_size; i++) { 1069 p = prev_level->composite_states[i]; 1070 if (t->index <= p->enable_parent_state && 1071 combine_lpi_states(p, t, flpi)) { 1072 stash_composite_state(curr_level, flpi); 1073 flat_state_cnt++; 1074 flpi++; 1075 } 1076 } 1077 } 1078 1079 kfree(curr_level->entries); 1080 return 0; 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 if (!osc_pc_lpi_support_confirmed) 1092 return -EOPNOTSUPP; 1093 1094 if (!acpi_has_method(handle, "_LPI")) 1095 return -EINVAL; 1096 1097 flat_state_cnt = 0; 1098 prev = &info[0]; 1099 curr = &info[1]; 1100 handle = pr->handle; 1101 ret = acpi_processor_evaluate_lpi(handle, prev); 1102 if (ret) 1103 return ret; 1104 flatten_lpi_states(pr, prev, NULL); 1105 1106 status = acpi_get_parent(handle, &pr_ahandle); 1107 while (ACPI_SUCCESS(status)) { 1108 d = acpi_fetch_acpi_dev(pr_ahandle); 1109 handle = pr_ahandle; 1110 1111 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1112 break; 1113 1114 /* can be optional ? */ 1115 if (!acpi_has_method(handle, "_LPI")) 1116 break; 1117 1118 ret = acpi_processor_evaluate_lpi(handle, curr); 1119 if (ret) 1120 break; 1121 1122 /* flatten all the LPI states in this level of hierarchy */ 1123 flatten_lpi_states(pr, curr, prev); 1124 1125 tmp = prev, prev = curr, curr = tmp; 1126 1127 status = acpi_get_parent(handle, &pr_ahandle); 1128 } 1129 1130 pr->power.count = flat_state_cnt; 1131 /* reset the index after flattening */ 1132 for (i = 0; i < pr->power.count; i++) 1133 pr->power.lpi_states[i].index = i; 1134 1135 /* Tell driver that _LPI is supported. */ 1136 pr->flags.has_lpi = 1; 1137 pr->flags.power = 1; 1138 1139 return 0; 1140 } 1141 1142 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1143 { 1144 return -ENODEV; 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