drivers/acpi/processor_idle.c

   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/tick.h>
  20 #include <linux/cpuidle.h>
  21 #include <linux/cpu.h>
  22 #include <acpi/processor.h>
  23
  24 /*
  25  * Include the apic definitions for x86 to have the APIC timer related defines
  26  * available also for UP (on SMP it gets magically included via linux/smp.h).
  27  * asm/acpi.h is not an option, as it would require more include magic. Also
  28  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  29  */
  30 #ifdef CONFIG_X86
  31 #include <asm/apic.h>
  32 #include <asm/cpu.h>
  33 #endif
  34
  35 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  36 ACPI_MODULE_NAME("processor_idle");
  37
  38 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  39
  40 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  41 module_param(max_cstate, uint, 0000);
  42 static unsigned int nocst __read_mostly;
  43 module_param(nocst, uint, 0000);
  44 static int bm_check_disable __read_mostly;
  45 module_param(bm_check_disable, uint, 0000);
  46
  47 static unsigned int latency_factor __read_mostly = 2;
  48 module_param(latency_factor, uint, 0644);
  49
  50 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  51
  52 struct cpuidle_driver acpi_idle_driver = {
  53         .name =         "acpi_idle",
  54         .owner =        THIS_MODULE,
  55 };
  56
  57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  58 static
  59 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  60
  61 static int disabled_by_idle_boot_param(void)
  62 {
  63         return boot_option_idle_override == IDLE_POLL ||
  64                 boot_option_idle_override == IDLE_HALT;
  65 }
  66
  67 /*
  68  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  69  * For now disable this. Probably a bug somewhere else.
  70  *
  71  * To skip this limit, boot/load with a large max_cstate limit.
  72  */
  73 static int set_max_cstate(const struct dmi_system_id *id)
  74 {
  75         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  76                 return 0;
  77
  78         pr_notice("%s detected - limiting to C%ld max_cstate."
  79                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  80                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  81
  82         max_cstate = (long)id->driver_data;
  83
  84         return 0;
  85 }
  86
  87 static const struct dmi_system_id processor_power_dmi_table[] = {
  88         { set_max_cstate, "Clevo 5600D", {
  89           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  90           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  91          (void *)2},
  92         { set_max_cstate, "Pavilion zv5000", {
  93           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  94           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  95          (void *)1},
  96         { set_max_cstate, "Asus L8400B", {
  97           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  98           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
  99          (void *)1},
 100         {},
 101 };
 102
 103
 104 /*
 105  * Callers should disable interrupts before the call and enable
 106  * interrupts after return.
 107  */
 108 static void __cpuidle acpi_safe_halt(void)
 109 {
 110         if (!tif_need_resched()) {
 111                 safe_halt();
 112                 local_irq_disable();
 113         }
 114 }
 115
 116 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 117
 118 /*
 119  * Some BIOS implementations switch to C3 in the published C2 state.
 120  * This seems to be a common problem on AMD boxen, but other vendors
 121  * are affected too. We pick the most conservative approach: we assume
 122  * that the local APIC stops in both C2 and C3.
 123  */
 124 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 125                                    struct acpi_processor_cx *cx)
 126 {
 127         struct acpi_processor_power *pwr = &pr->power;
 128         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 129
 130         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 131                 return;
 132
 133         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 134                 type = ACPI_STATE_C1;
 135
 136         /*
 137          * Check, if one of the previous states already marked the lapic
 138          * unstable
 139          */
 140         if (pwr->timer_broadcast_on_state < state)
 141                 return;
 142
 143         if (cx->type >= type)
 144                 pr->power.timer_broadcast_on_state = state;
 145 }
 146
 147 static void __lapic_timer_propagate_broadcast(void *arg)
 148 {
 149         struct acpi_processor *pr = (struct acpi_processor *) arg;
 150
 151         if (pr->power.timer_broadcast_on_state < INT_MAX)
 152                 tick_broadcast_enable();
 153         else
 154                 tick_broadcast_disable();
 155 }
 156
 157 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 158 {
 159         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 160                                  (void *)pr, 1);
 161 }
 162
 163 /* Power(C) State timer broadcast control */
 164 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 165                                         struct acpi_processor_cx *cx)
 166 {
 167         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 168 }
 169
 170 #else
 171
 172 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 173                                    struct acpi_processor_cx *cstate) { }
 174 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 175
 176 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 177                                         struct acpi_processor_cx *cx)
 178 {
 179         return false;
 180 }
 181
 182 #endif
 183
 184 #if defined(CONFIG_X86)
 185 static void tsc_check_state(int state)
 186 {
 187         switch (boot_cpu_data.x86_vendor) {
 188         case X86_VENDOR_HYGON:
 189         case X86_VENDOR_AMD:
 190         case X86_VENDOR_INTEL:
 191         case X86_VENDOR_CENTAUR:
 192         case X86_VENDOR_ZHAOXIN:
 193                 /*
 194                  * AMD Fam10h TSC will tick in all
 195                  * C/P/S0/S1 states when this bit is set.
 196                  */
 197                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 198                         return;
 199                 fallthrough;
 200         default:
 201                 /* TSC could halt in idle, so notify users */
 202                 if (state > ACPI_STATE_C1)
 203                         mark_tsc_unstable("TSC halts in idle");
 204         }
 205 }
 206 #else
 207 static void tsc_check_state(int state) { return; }
 208 #endif
 209
 210 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 211 {
 212
 213         if (!pr->pblk)
 214                 return -ENODEV;
 215
 216         /* if info is obtained from pblk/fadt, type equals state */
 217         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 218         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 219
 220 #ifndef CONFIG_HOTPLUG_CPU
 221         /*
 222          * Check for P_LVL2_UP flag before entering C2 and above on
 223          * an SMP system.
 224          */
 225         if ((num_online_cpus() > 1) &&
 226             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 227                 return -ENODEV;
 228 #endif
 229
 230         /* determine C2 and C3 address from pblk */
 231         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 232         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 233
 234         /* determine latencies from FADT */
 235         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 236         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 237
 238         /*
 239          * FADT specified C2 latency must be less than or equal to
 240          * 100 microseconds.
 241          */
 242         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 243                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 244                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 245                 /* invalidate C2 */
 246                 pr->power.states[ACPI_STATE_C2].address = 0;
 247         }
 248
 249         /*
 250          * FADT supplied C3 latency must be less than or equal to
 251          * 1000 microseconds.
 252          */
 253         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 254                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 255                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 256                 /* invalidate C3 */
 257                 pr->power.states[ACPI_STATE_C3].address = 0;
 258         }
 259
 260         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 261                           "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         else if (errata.piix4.fdma) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 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_DEBUG_PRINT((ACPI_DB_INFO,
 349                                         "C3 support requires BM control\n"));
 350                                 return;
 351                         } else {
 352                                 /* Here we enter C3 without bus mastering */
 353                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 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_DEBUG_PRINT((ACPI_DB_INFO,
 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         return;
 389 }
 390
 391 static int acpi_processor_power_verify(struct acpi_processor *pr)
 392 {
 393         unsigned int i;
 394         unsigned int working = 0;
 395
 396         pr->power.timer_broadcast_on_state = INT_MAX;
 397
 398         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 399                 struct acpi_processor_cx *cx = &pr->power.states[i];
 400
 401                 switch (cx->type) {
 402                 case ACPI_STATE_C1:
 403                         cx->valid = 1;
 404                         break;
 405
 406                 case ACPI_STATE_C2:
 407                         if (!cx->address)
 408                                 break;
 409                         cx->valid = 1;
 410                         break;
 411
 412                 case ACPI_STATE_C3:
 413                         acpi_processor_power_verify_c3(pr, cx);
 414                         break;
 415                 }
 416                 if (!cx->valid)
 417                         continue;
 418
 419                 lapic_timer_check_state(i, pr, cx);
 420                 tsc_check_state(cx->type);
 421                 working++;
 422         }
 423
 424         lapic_timer_propagate_broadcast(pr);
 425
 426         return (working);
 427 }
 428
 429 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 430 {
 431         unsigned int i;
 432         int result;
 433
 434
 435         /* NOTE: the idle thread may not be running while calling
 436          * this function */
 437
 438         /* Zero initialize all the C-states info. */
 439         memset(pr->power.states, 0, sizeof(pr->power.states));
 440
 441         result = acpi_processor_get_power_info_cst(pr);
 442         if (result == -ENODEV)
 443                 result = acpi_processor_get_power_info_fadt(pr);
 444
 445         if (result)
 446                 return result;
 447
 448         acpi_processor_get_power_info_default(pr);
 449
 450         pr->power.count = acpi_processor_power_verify(pr);
 451
 452         /*
 453          * if one state of type C2 or C3 is available, mark this
 454          * CPU as being "idle manageable"
 455          */
 456         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 457                 if (pr->power.states[i].valid) {
 458                         pr->power.count = i;
 459                         pr->flags.power = 1;
 460                 }
 461         }
 462
 463         return 0;
 464 }
 465
 466 /**
 467  * acpi_idle_bm_check - checks if bus master activity was detected
 468  */
 469 static int acpi_idle_bm_check(void)
 470 {
 471         u32 bm_status = 0;
 472
 473         if (bm_check_disable)
 474                 return 0;
 475
 476         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 477         if (bm_status)
 478                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 479         /*
 480          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 481          * the true state of bus mastering activity; forcing us to
 482          * manually check the BMIDEA bit of each IDE channel.
 483          */
 484         else if (errata.piix4.bmisx) {
 485                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 486                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 487                         bm_status = 1;
 488         }
 489         return bm_status;
 490 }
 491
 492 static void wait_for_freeze(void)
 493 {
 494 #ifdef  CONFIG_X86
 495         /* No delay is needed if we are in guest */
 496         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 497                 return;
 498 #endif
 499         /* Dummy wait op - must do something useless after P_LVL2 read
 500            because chipsets cannot guarantee that STPCLK# signal
 501            gets asserted in time to freeze execution properly. */
 502         inl(acpi_gbl_FADT.xpm_timer_block.address);
 503 }
 504
 505 /**
 506  * acpi_idle_do_entry - enter idle state using the appropriate method
 507  * @cx: cstate data
 508  *
 509  * Caller disables interrupt before call and enables interrupt after return.
 510  */
 511 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 512 {
 513         if (cx->entry_method == ACPI_CSTATE_FFH) {
 514                 /* Call into architectural FFH based C-state */
 515                 acpi_processor_ffh_cstate_enter(cx);
 516         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 517                 acpi_safe_halt();
 518         } else {
 519                 /* IO port based C-state */
 520                 inb(cx->address);
 521                 wait_for_freeze();
 522         }
 523 }
 524
 525 /**
 526  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 527  * @dev: the target CPU
 528  * @index: the index of suggested state
 529  */
 530 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 531 {
 532         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 533
 534         ACPI_FLUSH_CPU_CACHE();
 535
 536         while (1) {
 537
 538                 if (cx->entry_method == ACPI_CSTATE_HALT)
 539                         safe_halt();
 540                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 541                         inb(cx->address);
 542                         wait_for_freeze();
 543                 } else
 544                         return -ENODEV;
 545
 546 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
 547                 /* If NMI wants to wake up CPU0, start CPU0. */
 548                 if (wakeup_cpu0())
 549                         start_cpu0();
 550 #endif
 551         }
 552
 553         /* Never reached */
 554         return 0;
 555 }
 556
 557 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 558 {
 559         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 560                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 561 }
 562
 563 static int c3_cpu_count;
 564 static DEFINE_RAW_SPINLOCK(c3_lock);
 565
 566 /**
 567  * acpi_idle_enter_bm - enters C3 with proper BM handling
 568  * @drv: cpuidle driver
 569  * @pr: Target processor
 570  * @cx: Target state context
 571  * @index: index of target state
 572  */
 573 static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
 574                                struct acpi_processor *pr,
 575                                struct acpi_processor_cx *cx,
 576                                int index)
 577 {
 578         static struct acpi_processor_cx safe_cx = {
 579                 .entry_method = ACPI_CSTATE_HALT,
 580         };
 581
 582         /*
 583          * disable bus master
 584          * bm_check implies we need ARB_DIS
 585          * bm_control implies whether we can do ARB_DIS
 586          *
 587          * That leaves a case where bm_check is set and bm_control is not set.
 588          * In that case we cannot do much, we enter C3 without doing anything.
 589          */
 590         bool dis_bm = pr->flags.bm_control;
 591
 592         /* If we can skip BM, demote to a safe state. */
 593         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 594                 dis_bm = false;
 595                 index = drv->safe_state_index;
 596                 if (index >= 0) {
 597                         cx = this_cpu_read(acpi_cstate[index]);
 598                 } else {
 599                         cx = &safe_cx;
 600                         index = -EBUSY;
 601                 }
 602         }
 603
 604         if (dis_bm) {
 605                 raw_spin_lock(&c3_lock);
 606                 c3_cpu_count++;
 607                 /* Disable bus master arbitration when all CPUs are in C3 */
 608                 if (c3_cpu_count == num_online_cpus())
 609                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 610                 raw_spin_unlock(&c3_lock);
 611         }
 612
 613         rcu_idle_enter();
 614
 615         acpi_idle_do_entry(cx);
 616
 617         rcu_idle_exit();
 618
 619         /* Re-enable bus master arbitration */
 620         if (dis_bm) {
 621                 raw_spin_lock(&c3_lock);
 622                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 623                 c3_cpu_count--;
 624                 raw_spin_unlock(&c3_lock);
 625         }
 626
 627         return index;
 628 }
 629
 630 static int acpi_idle_enter(struct cpuidle_device *dev,
 631                            struct cpuidle_driver *drv, int index)
 632 {
 633         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 634         struct acpi_processor *pr;
 635
 636         pr = __this_cpu_read(processors);
 637         if (unlikely(!pr))
 638                 return -EINVAL;
 639
 640         if (cx->type != ACPI_STATE_C1) {
 641                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 642                         return acpi_idle_enter_bm(drv, pr, cx, index);
 643
 644                 /* C2 to C1 demotion. */
 645                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 646                         index = ACPI_IDLE_STATE_START;
 647                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 648                 }
 649         }
 650
 651         if (cx->type == ACPI_STATE_C3)
 652                 ACPI_FLUSH_CPU_CACHE();
 653
 654         acpi_idle_do_entry(cx);
 655
 656         return index;
 657 }
 658
 659 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 660                                   struct cpuidle_driver *drv, int index)
 661 {
 662         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 663
 664         if (cx->type == ACPI_STATE_C3) {
 665                 struct acpi_processor *pr = __this_cpu_read(processors);
 666
 667                 if (unlikely(!pr))
 668                         return 0;
 669
 670                 if (pr->flags.bm_check) {
 671                         u8 bm_sts_skip = cx->bm_sts_skip;
 672
 673                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 674                         cx->bm_sts_skip = 1;
 675                         acpi_idle_enter_bm(drv, pr, cx, index);
 676                         cx->bm_sts_skip = bm_sts_skip;
 677
 678                         return 0;
 679                 } else {
 680                         ACPI_FLUSH_CPU_CACHE();
 681                 }
 682         }
 683         acpi_idle_do_entry(cx);
 684
 685         return 0;
 686 }
 687
 688 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 689                                            struct cpuidle_device *dev)
 690 {
 691         int i, count = ACPI_IDLE_STATE_START;
 692         struct acpi_processor_cx *cx;
 693         struct cpuidle_state *state;
 694
 695         if (max_cstate == 0)
 696                 max_cstate = 1;
 697
 698         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 699                 state = &acpi_idle_driver.states[count];
 700                 cx = &pr->power.states[i];
 701
 702                 if (!cx->valid)
 703                         continue;
 704
 705                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 706
 707                 if (lapic_timer_needs_broadcast(pr, cx))
 708                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 709
 710                 if (cx->type == ACPI_STATE_C3) {
 711                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 712                         if (pr->flags.bm_check)
 713                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 714                 }
 715
 716                 count++;
 717                 if (count == CPUIDLE_STATE_MAX)
 718                         break;
 719         }
 720
 721         if (!count)
 722                 return -EINVAL;
 723
 724         return 0;
 725 }
 726
 727 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 728 {
 729         int i, count;
 730         struct acpi_processor_cx *cx;
 731         struct cpuidle_state *state;
 732         struct cpuidle_driver *drv = &acpi_idle_driver;
 733
 734         if (max_cstate == 0)
 735                 max_cstate = 1;
 736
 737         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 738                 cpuidle_poll_state_init(drv);
 739                 count = 1;
 740         } else {
 741                 count = 0;
 742         }
 743
 744         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 745                 cx = &pr->power.states[i];
 746
 747                 if (!cx->valid)
 748                         continue;
 749
 750                 state = &drv->states[count];
 751                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 752                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 753                 state->exit_latency = cx->latency;
 754                 state->target_residency = cx->latency * latency_factor;
 755                 state->enter = acpi_idle_enter;
 756
 757                 state->flags = 0;
 758                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 759                         state->enter_dead = acpi_idle_play_dead;
 760                         drv->safe_state_index = count;
 761                 }
 762                 /*
 763                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 764                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 765                  * particularly interesting from the suspend-to-idle angle, so
 766                  * avoid C1 and the situations in which we may need to fall back
 767                  * to it altogether.
 768                  */
 769                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 770                         state->enter_s2idle = acpi_idle_enter_s2idle;
 771
 772                 count++;
 773                 if (count == CPUIDLE_STATE_MAX)
 774                         break;
 775         }
 776
 777         drv->state_count = count;
 778
 779         if (!count)
 780                 return -EINVAL;
 781
 782         return 0;
 783 }
 784
 785 static inline void acpi_processor_cstate_first_run_checks(void)
 786 {
 787         static int first_run;
 788
 789         if (first_run)
 790                 return;
 791         dmi_check_system(processor_power_dmi_table);
 792         max_cstate = acpi_processor_cstate_check(max_cstate);
 793         if (max_cstate < ACPI_C_STATES_MAX)
 794                 pr_notice("ACPI: processor limited to max C-state %d\n",
 795                           max_cstate);
 796         first_run++;
 797
 798         if (nocst)
 799                 return;
 800
 801         acpi_processor_claim_cst_control();
 802 }
 803 #else
 804
 805 static inline int disabled_by_idle_boot_param(void) { return 0; }
 806 static inline void acpi_processor_cstate_first_run_checks(void) { }
 807 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 808 {
 809         return -ENODEV;
 810 }
 811
 812 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 813                                            struct cpuidle_device *dev)
 814 {
 815         return -EINVAL;
 816 }
 817
 818 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 819 {
 820         return -EINVAL;
 821 }
 822
 823 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 824
 825 struct acpi_lpi_states_array {
 826         unsigned int size;
 827         unsigned int composite_states_size;
 828         struct acpi_lpi_state *entries;
 829         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 830 };
 831
 832 static int obj_get_integer(union acpi_object *obj, u32 *value)
 833 {
 834         if (obj->type != ACPI_TYPE_INTEGER)
 835                 return -EINVAL;
 836
 837         *value = obj->integer.value;
 838         return 0;
 839 }
 840
 841 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 842                                        struct acpi_lpi_states_array *info)
 843 {
 844         acpi_status status;
 845         int ret = 0;
 846         int pkg_count, state_idx = 1, loop;
 847         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 848         union acpi_object *lpi_data;
 849         struct acpi_lpi_state *lpi_state;
 850
 851         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 852         if (ACPI_FAILURE(status)) {
 853                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 854                 return -ENODEV;
 855         }
 856
 857         lpi_data = buffer.pointer;
 858
 859         /* There must be at least 4 elements = 3 elements + 1 package */
 860         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 861             lpi_data->package.count < 4) {
 862                 pr_debug("not enough elements in _LPI\n");
 863                 ret = -ENODATA;
 864                 goto end;
 865         }
 866
 867         pkg_count = lpi_data->package.elements[2].integer.value;
 868
 869         /* Validate number of power states. */
 870         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 871                 pr_debug("count given by _LPI is not valid\n");
 872                 ret = -ENODATA;
 873                 goto end;
 874         }
 875
 876         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 877         if (!lpi_state) {
 878                 ret = -ENOMEM;
 879                 goto end;
 880         }
 881
 882         info->size = pkg_count;
 883         info->entries = lpi_state;
 884
 885         /* LPI States start at index 3 */
 886         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 887                 union acpi_object *element, *pkg_elem, *obj;
 888
 889                 element = &lpi_data->package.elements[loop];
 890                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 891                         continue;
 892
 893                 pkg_elem = element->package.elements;
 894
 895                 obj = pkg_elem + 6;
 896                 if (obj->type == ACPI_TYPE_BUFFER) {
 897                         struct acpi_power_register *reg;
 898
 899                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 900                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 901                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 902                                 continue;
 903
 904                         lpi_state->address = reg->address;
 905                         lpi_state->entry_method =
 906                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 907                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 908                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 909                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 910                         lpi_state->address = obj->integer.value;
 911                 } else {
 912                         continue;
 913                 }
 914
 915                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 916
 917                 obj = pkg_elem + 9;
 918                 if (obj->type == ACPI_TYPE_STRING)
 919                         strlcpy(lpi_state->desc, obj->string.pointer,
 920                                 ACPI_CX_DESC_LEN);
 921
 922                 lpi_state->index = state_idx;
 923                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 924                         pr_debug("No min. residency found, assuming 10 us\n");
 925                         lpi_state->min_residency = 10;
 926                 }
 927
 928                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 929                         pr_debug("No wakeup residency found, assuming 10 us\n");
 930                         lpi_state->wake_latency = 10;
 931                 }
 932
 933                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 934                         lpi_state->flags = 0;
 935
 936                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 937                         lpi_state->arch_flags = 0;
 938
 939                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 940                         lpi_state->res_cnt_freq = 1;
 941
 942                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 943                         lpi_state->enable_parent_state = 0;
 944         }
 945
 946         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 947 end:
 948         kfree(buffer.pointer);
 949         return ret;
 950 }
 951
 952 /*
 953  * flat_state_cnt - the number of composite LPI states after the process of flattening
 954  */
 955 static int flat_state_cnt;
 956
 957 /**
 958  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 959  *
 960  * @local: local LPI state
 961  * @parent: parent LPI state
 962  * @result: composite LPI state
 963  */
 964 static bool combine_lpi_states(struct acpi_lpi_state *local,
 965                                struct acpi_lpi_state *parent,
 966                                struct acpi_lpi_state *result)
 967 {
 968         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
 969                 if (!parent->address) /* 0 means autopromotable */
 970                         return false;
 971                 result->address = local->address + parent->address;
 972         } else {
 973                 result->address = parent->address;
 974         }
 975
 976         result->min_residency = max(local->min_residency, parent->min_residency);
 977         result->wake_latency = local->wake_latency + parent->wake_latency;
 978         result->enable_parent_state = parent->enable_parent_state;
 979         result->entry_method = local->entry_method;
 980
 981         result->flags = parent->flags;
 982         result->arch_flags = parent->arch_flags;
 983         result->index = parent->index;
 984
 985         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
 986         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
 987         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
 988         return true;
 989 }
 990
 991 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
 992
 993 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
 994                                   struct acpi_lpi_state *t)
 995 {
 996         curr_level->composite_states[curr_level->composite_states_size++] = t;
 997 }
 998
 999 static int flatten_lpi_states(struct acpi_processor *pr,
1000                               struct acpi_lpi_states_array *curr_level,
1001                               struct acpi_lpi_states_array *prev_level)
1002 {
1003         int i, j, state_count = curr_level->size;
1004         struct acpi_lpi_state *p, *t = curr_level->entries;
1005
1006         curr_level->composite_states_size = 0;
1007         for (j = 0; j < state_count; j++, t++) {
1008                 struct acpi_lpi_state *flpi;
1009
1010                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1011                         continue;
1012
1013                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1014                         pr_warn("Limiting number of LPI states to max (%d)\n",
1015                                 ACPI_PROCESSOR_MAX_POWER);
1016                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1017                         break;
1018                 }
1019
1020                 flpi = &pr->power.lpi_states[flat_state_cnt];
1021
1022                 if (!prev_level) { /* leaf/processor node */
1023                         memcpy(flpi, t, sizeof(*t));
1024                         stash_composite_state(curr_level, flpi);
1025                         flat_state_cnt++;
1026                         continue;
1027                 }
1028
1029                 for (i = 0; i < prev_level->composite_states_size; i++) {
1030                         p = prev_level->composite_states[i];
1031                         if (t->index <= p->enable_parent_state &&
1032                             combine_lpi_states(p, t, flpi)) {
1033                                 stash_composite_state(curr_level, flpi);
1034                                 flat_state_cnt++;
1035                                 flpi++;
1036                         }
1037                 }
1038         }
1039
1040         kfree(curr_level->entries);
1041         return 0;
1042 }
1043
1044 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1045 {
1046         int ret, i;
1047         acpi_status status;
1048         acpi_handle handle = pr->handle, pr_ahandle;
1049         struct acpi_device *d = NULL;
1050         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1051
1052         if (!osc_pc_lpi_support_confirmed)
1053                 return -EOPNOTSUPP;
1054
1055         if (!acpi_has_method(handle, "_LPI"))
1056                 return -EINVAL;
1057
1058         flat_state_cnt = 0;
1059         prev = &info[0];
1060         curr = &info[1];
1061         handle = pr->handle;
1062         ret = acpi_processor_evaluate_lpi(handle, prev);
1063         if (ret)
1064                 return ret;
1065         flatten_lpi_states(pr, prev, NULL);
1066
1067         status = acpi_get_parent(handle, &pr_ahandle);
1068         while (ACPI_SUCCESS(status)) {
1069                 acpi_bus_get_device(pr_ahandle, &d);
1070                 handle = pr_ahandle;
1071
1072                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1073                         break;
1074
1075                 /* can be optional ? */
1076                 if (!acpi_has_method(handle, "_LPI"))
1077                         break;
1078
1079                 ret = acpi_processor_evaluate_lpi(handle, curr);
1080                 if (ret)
1081                         break;
1082
1083                 /* flatten all the LPI states in this level of hierarchy */
1084                 flatten_lpi_states(pr, curr, prev);
1085
1086                 tmp = prev, prev = curr, curr = tmp;
1087
1088                 status = acpi_get_parent(handle, &pr_ahandle);
1089         }
1090
1091         pr->power.count = flat_state_cnt;
1092         /* reset the index after flattening */
1093         for (i = 0; i < pr->power.count; i++)
1094                 pr->power.lpi_states[i].index = i;
1095
1096         /* Tell driver that _LPI is supported. */
1097         pr->flags.has_lpi = 1;
1098         pr->flags.power = 1;
1099
1100         return 0;
1101 }
1102
1103 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1104 {
1105         return -ENODEV;
1106 }
1107
1108 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1109 {
1110         return -ENODEV;
1111 }
1112
1113 /**
1114  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1115  * @dev: the target CPU
1116  * @drv: cpuidle driver containing cpuidle state info
1117  * @index: index of target state
1118  *
1119  * Return: 0 for success or negative value for error
1120  */
1121 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1122                                struct cpuidle_driver *drv, int index)
1123 {
1124         struct acpi_processor *pr;
1125         struct acpi_lpi_state *lpi;
1126
1127         pr = __this_cpu_read(processors);
1128
1129         if (unlikely(!pr))
1130                 return -EINVAL;
1131
1132         lpi = &pr->power.lpi_states[index];
1133         if (lpi->entry_method == ACPI_CSTATE_FFH)
1134                 return acpi_processor_ffh_lpi_enter(lpi);
1135
1136         return -EINVAL;
1137 }
1138
1139 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1140 {
1141         int i;
1142         struct acpi_lpi_state *lpi;
1143         struct cpuidle_state *state;
1144         struct cpuidle_driver *drv = &acpi_idle_driver;
1145
1146         if (!pr->flags.has_lpi)
1147                 return -EOPNOTSUPP;
1148
1149         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1150                 lpi = &pr->power.lpi_states[i];
1151
1152                 state = &drv->states[i];
1153                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1154                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1155                 state->exit_latency = lpi->wake_latency;
1156                 state->target_residency = lpi->min_residency;
1157                 if (lpi->arch_flags)
1158                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1159                 state->enter = acpi_idle_lpi_enter;
1160                 drv->safe_state_index = i;
1161         }
1162
1163         drv->state_count = i;
1164
1165         return 0;
1166 }
1167
1168 /**
1169  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1170  * global state data i.e. idle routines
1171  *
1172  * @pr: the ACPI processor
1173  */
1174 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1175 {
1176         int i;
1177         struct cpuidle_driver *drv = &acpi_idle_driver;
1178
1179         if (!pr->flags.power_setup_done || !pr->flags.power)
1180                 return -EINVAL;
1181
1182         drv->safe_state_index = -1;
1183         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1184                 drv->states[i].name[0] = '\0';
1185                 drv->states[i].desc[0] = '\0';
1186         }
1187
1188         if (pr->flags.has_lpi)
1189                 return acpi_processor_setup_lpi_states(pr);
1190
1191         return acpi_processor_setup_cstates(pr);
1192 }
1193
1194 /**
1195  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1196  * device i.e. per-cpu data
1197  *
1198  * @pr: the ACPI processor
1199  * @dev : the cpuidle device
1200  */
1201 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1202                                             struct cpuidle_device *dev)
1203 {
1204         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1205                 return -EINVAL;
1206
1207         dev->cpu = pr->id;
1208         if (pr->flags.has_lpi)
1209                 return acpi_processor_ffh_lpi_probe(pr->id);
1210
1211         return acpi_processor_setup_cpuidle_cx(pr, dev);
1212 }
1213
1214 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1215 {
1216         int ret;
1217
1218         ret = acpi_processor_get_lpi_info(pr);
1219         if (ret)
1220                 ret = acpi_processor_get_cstate_info(pr);
1221
1222         return ret;
1223 }
1224
1225 int acpi_processor_hotplug(struct acpi_processor *pr)
1226 {
1227         int ret = 0;
1228         struct cpuidle_device *dev;
1229
1230         if (disabled_by_idle_boot_param())
1231                 return 0;
1232
1233         if (!pr->flags.power_setup_done)
1234                 return -ENODEV;
1235
1236         dev = per_cpu(acpi_cpuidle_device, pr->id);
1237         cpuidle_pause_and_lock();
1238         cpuidle_disable_device(dev);
1239         ret = acpi_processor_get_power_info(pr);
1240         if (!ret && pr->flags.power) {
1241                 acpi_processor_setup_cpuidle_dev(pr, dev);
1242                 ret = cpuidle_enable_device(dev);
1243         }
1244         cpuidle_resume_and_unlock();
1245
1246         return ret;
1247 }
1248
1249 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1250 {
1251         int cpu;
1252         struct acpi_processor *_pr;
1253         struct cpuidle_device *dev;
1254
1255         if (disabled_by_idle_boot_param())
1256                 return 0;
1257
1258         if (!pr->flags.power_setup_done)
1259                 return -ENODEV;
1260
1261         /*
1262          * FIXME:  Design the ACPI notification to make it once per
1263          * system instead of once per-cpu.  This condition is a hack
1264          * to make the code that updates C-States be called once.
1265          */
1266
1267         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1268
1269                 /* Protect against cpu-hotplug */
1270                 get_online_cpus();
1271                 cpuidle_pause_and_lock();
1272
1273                 /* Disable all cpuidle devices */
1274                 for_each_online_cpu(cpu) {
1275                         _pr = per_cpu(processors, cpu);
1276                         if (!_pr || !_pr->flags.power_setup_done)
1277                                 continue;
1278                         dev = per_cpu(acpi_cpuidle_device, cpu);
1279                         cpuidle_disable_device(dev);
1280                 }
1281
1282                 /* Populate Updated C-state information */
1283                 acpi_processor_get_power_info(pr);
1284                 acpi_processor_setup_cpuidle_states(pr);
1285
1286                 /* Enable all cpuidle devices */
1287                 for_each_online_cpu(cpu) {
1288                         _pr = per_cpu(processors, cpu);
1289                         if (!_pr || !_pr->flags.power_setup_done)
1290                                 continue;
1291                         acpi_processor_get_power_info(_pr);
1292                         if (_pr->flags.power) {
1293                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1294                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1295                                 cpuidle_enable_device(dev);
1296                         }
1297                 }
1298                 cpuidle_resume_and_unlock();
1299                 put_online_cpus();
1300         }
1301
1302         return 0;
1303 }
1304
1305 static int acpi_processor_registered;
1306
1307 int acpi_processor_power_init(struct acpi_processor *pr)
1308 {
1309         int retval;
1310         struct cpuidle_device *dev;
1311
1312         if (disabled_by_idle_boot_param())
1313                 return 0;
1314
1315         acpi_processor_cstate_first_run_checks();
1316
1317         if (!acpi_processor_get_power_info(pr))
1318                 pr->flags.power_setup_done = 1;
1319
1320         /*
1321          * Install the idle handler if processor power management is supported.
1322          * Note that we use previously set idle handler will be used on
1323          * platforms that only support C1.
1324          */
1325         if (pr->flags.power) {
1326                 /* Register acpi_idle_driver if not already registered */
1327                 if (!acpi_processor_registered) {
1328                         acpi_processor_setup_cpuidle_states(pr);
1329                         retval = cpuidle_register_driver(&acpi_idle_driver);
1330                         if (retval)
1331                                 return retval;
1332                         pr_debug("%s registered with cpuidle\n",
1333                                  acpi_idle_driver.name);
1334                 }
1335
1336                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1337                 if (!dev)
1338                         return -ENOMEM;
1339                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1340
1341                 acpi_processor_setup_cpuidle_dev(pr, dev);
1342
1343                 /* Register per-cpu cpuidle_device. Cpuidle driver
1344                  * must already be registered before registering device
1345                  */
1346                 retval = cpuidle_register_device(dev);
1347                 if (retval) {
1348                         if (acpi_processor_registered == 0)
1349                                 cpuidle_unregister_driver(&acpi_idle_driver);
1350                         return retval;
1351                 }
1352                 acpi_processor_registered++;
1353         }
1354         return 0;
1355 }
1356
1357 int acpi_processor_power_exit(struct acpi_processor *pr)
1358 {
1359         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1360
1361         if (disabled_by_idle_boot_param())
1362                 return 0;
1363
1364         if (pr->flags.power) {
1365                 cpuidle_unregister_device(dev);
1366                 acpi_processor_registered--;
1367                 if (acpi_processor_registered == 0)
1368                         cpuidle_unregister_driver(&acpi_idle_driver);
1369         }
1370
1371         pr->flags.power_setup_done = 0;
1372         return 0;
1373 }