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 #endif
  33
  34 #define ACPI_PROCESSOR_CLASS            "processor"
  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 void lapic_timer_state_broadcast(struct acpi_processor *pr,
 165                                        struct acpi_processor_cx *cx,
 166                                        int broadcast)
 167 {
 168         int state = cx - pr->power.states;
 169
 170         if (state >= pr->power.timer_broadcast_on_state) {
 171                 if (broadcast)
 172                         tick_broadcast_enter();
 173                 else
 174                         tick_broadcast_exit();
 175         }
 176 }
 177
 178 #else
 179
 180 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 181                                    struct acpi_processor_cx *cstate) { }
 182 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 183 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 184                                        struct acpi_processor_cx *cx,
 185                                        int broadcast)
 186 {
 187 }
 188
 189 #endif
 190
 191 #if defined(CONFIG_X86)
 192 static void tsc_check_state(int state)
 193 {
 194         switch (boot_cpu_data.x86_vendor) {
 195         case X86_VENDOR_HYGON:
 196         case X86_VENDOR_AMD:
 197         case X86_VENDOR_INTEL:
 198         case X86_VENDOR_CENTAUR:
 199         case X86_VENDOR_ZHAOXIN:
 200                 /*
 201                  * AMD Fam10h TSC will tick in all
 202                  * C/P/S0/S1 states when this bit is set.
 203                  */
 204                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 205                         return;
 206
 207                 /*FALL THROUGH*/
 208         default:
 209                 /* TSC could halt in idle, so notify users */
 210                 if (state > ACPI_STATE_C1)
 211                         mark_tsc_unstable("TSC halts in idle");
 212         }
 213 }
 214 #else
 215 static void tsc_check_state(int state) { return; }
 216 #endif
 217
 218 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 219 {
 220
 221         if (!pr->pblk)
 222                 return -ENODEV;
 223
 224         /* if info is obtained from pblk/fadt, type equals state */
 225         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 226         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 227
 228 #ifndef CONFIG_HOTPLUG_CPU
 229         /*
 230          * Check for P_LVL2_UP flag before entering C2 and above on
 231          * an SMP system.
 232          */
 233         if ((num_online_cpus() > 1) &&
 234             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 235                 return -ENODEV;
 236 #endif
 237
 238         /* determine C2 and C3 address from pblk */
 239         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 240         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 241
 242         /* determine latencies from FADT */
 243         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 244         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 245
 246         /*
 247          * FADT specified C2 latency must be less than or equal to
 248          * 100 microseconds.
 249          */
 250         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 251                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 252                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 253                 /* invalidate C2 */
 254                 pr->power.states[ACPI_STATE_C2].address = 0;
 255         }
 256
 257         /*
 258          * FADT supplied C3 latency must be less than or equal to
 259          * 1000 microseconds.
 260          */
 261         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 264                 /* invalidate C3 */
 265                 pr->power.states[ACPI_STATE_C3].address = 0;
 266         }
 267
 268         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 269                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 270                           pr->power.states[ACPI_STATE_C2].address,
 271                           pr->power.states[ACPI_STATE_C3].address));
 272
 273         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 274                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 275                          pr->power.states[ACPI_STATE_C2].address);
 276         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 277                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 278                          pr->power.states[ACPI_STATE_C3].address);
 279
 280         return 0;
 281 }
 282
 283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 284 {
 285         if (!pr->power.states[ACPI_STATE_C1].valid) {
 286                 /* set the first C-State to C1 */
 287                 /* all processors need to support C1 */
 288                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 289                 pr->power.states[ACPI_STATE_C1].valid = 1;
 290                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 291
 292                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 293                          ACPI_CX_DESC_LEN, "ACPI HLT");
 294         }
 295         /* the C0 state only exists as a filler in our array */
 296         pr->power.states[ACPI_STATE_C0].valid = 1;
 297         return 0;
 298 }
 299
 300 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 301 {
 302         int ret;
 303
 304         if (nocst)
 305                 return -ENODEV;
 306
 307         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 308         if (ret)
 309                 return ret;
 310
 311         if (!pr->power.count)
 312                 return -EFAULT;
 313
 314         pr->flags.has_cst = 1;
 315         return 0;
 316 }
 317
 318 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 319                                            struct acpi_processor_cx *cx)
 320 {
 321         static int bm_check_flag = -1;
 322         static int bm_control_flag = -1;
 323
 324
 325         if (!cx->address)
 326                 return;
 327
 328         /*
 329          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 330          * DMA transfers are used by any ISA device to avoid livelock.
 331          * Note that we could disable Type-F DMA (as recommended by
 332          * the erratum), but this is known to disrupt certain ISA
 333          * devices thus we take the conservative approach.
 334          */
 335         else if (errata.piix4.fdma) {
 336                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 337                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 338                 return;
 339         }
 340
 341         /* All the logic here assumes flags.bm_check is same across all CPUs */
 342         if (bm_check_flag == -1) {
 343                 /* Determine whether bm_check is needed based on CPU  */
 344                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 345                 bm_check_flag = pr->flags.bm_check;
 346                 bm_control_flag = pr->flags.bm_control;
 347         } else {
 348                 pr->flags.bm_check = bm_check_flag;
 349                 pr->flags.bm_control = bm_control_flag;
 350         }
 351
 352         if (pr->flags.bm_check) {
 353                 if (!pr->flags.bm_control) {
 354                         if (pr->flags.has_cst != 1) {
 355                                 /* bus mastering control is necessary */
 356                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 357                                         "C3 support requires BM control\n"));
 358                                 return;
 359                         } else {
 360                                 /* Here we enter C3 without bus mastering */
 361                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 362                                         "C3 support without BM control\n"));
 363                         }
 364                 }
 365         } else {
 366                 /*
 367                  * WBINVD should be set in fadt, for C3 state to be
 368                  * supported on when bm_check is not required.
 369                  */
 370                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 371                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 372                                           "Cache invalidation should work properly"
 373                                           " for C3 to be enabled on SMP systems\n"));
 374                         return;
 375                 }
 376         }
 377
 378         /*
 379          * Otherwise we've met all of our C3 requirements.
 380          * Normalize the C3 latency to expidite policy.  Enable
 381          * checking of bus mastering status (bm_check) so we can
 382          * use this in our C3 policy
 383          */
 384         cx->valid = 1;
 385
 386         /*
 387          * On older chipsets, BM_RLD needs to be set
 388          * in order for Bus Master activity to wake the
 389          * system from C3.  Newer chipsets handle DMA
 390          * during C3 automatically and BM_RLD is a NOP.
 391          * In either case, the proper way to
 392          * handle BM_RLD is to set it and leave it set.
 393          */
 394         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 395
 396         return;
 397 }
 398
 399 static int acpi_processor_power_verify(struct acpi_processor *pr)
 400 {
 401         unsigned int i;
 402         unsigned int working = 0;
 403
 404         pr->power.timer_broadcast_on_state = INT_MAX;
 405
 406         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 407                 struct acpi_processor_cx *cx = &pr->power.states[i];
 408
 409                 switch (cx->type) {
 410                 case ACPI_STATE_C1:
 411                         cx->valid = 1;
 412                         break;
 413
 414                 case ACPI_STATE_C2:
 415                         if (!cx->address)
 416                                 break;
 417                         cx->valid = 1;
 418                         break;
 419
 420                 case ACPI_STATE_C3:
 421                         acpi_processor_power_verify_c3(pr, cx);
 422                         break;
 423                 }
 424                 if (!cx->valid)
 425                         continue;
 426
 427                 lapic_timer_check_state(i, pr, cx);
 428                 tsc_check_state(cx->type);
 429                 working++;
 430         }
 431
 432         lapic_timer_propagate_broadcast(pr);
 433
 434         return (working);
 435 }
 436
 437 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 438 {
 439         unsigned int i;
 440         int result;
 441
 442
 443         /* NOTE: the idle thread may not be running while calling
 444          * this function */
 445
 446         /* Zero initialize all the C-states info. */
 447         memset(pr->power.states, 0, sizeof(pr->power.states));
 448
 449         result = acpi_processor_get_power_info_cst(pr);
 450         if (result == -ENODEV)
 451                 result = acpi_processor_get_power_info_fadt(pr);
 452
 453         if (result)
 454                 return result;
 455
 456         acpi_processor_get_power_info_default(pr);
 457
 458         pr->power.count = acpi_processor_power_verify(pr);
 459
 460         /*
 461          * if one state of type C2 or C3 is available, mark this
 462          * CPU as being "idle manageable"
 463          */
 464         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 465                 if (pr->power.states[i].valid) {
 466                         pr->power.count = i;
 467                         pr->flags.power = 1;
 468                 }
 469         }
 470
 471         return 0;
 472 }
 473
 474 /**
 475  * acpi_idle_bm_check - checks if bus master activity was detected
 476  */
 477 static int acpi_idle_bm_check(void)
 478 {
 479         u32 bm_status = 0;
 480
 481         if (bm_check_disable)
 482                 return 0;
 483
 484         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 485         if (bm_status)
 486                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 487         /*
 488          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 489          * the true state of bus mastering activity; forcing us to
 490          * manually check the BMIDEA bit of each IDE channel.
 491          */
 492         else if (errata.piix4.bmisx) {
 493                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 494                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 495                         bm_status = 1;
 496         }
 497         return bm_status;
 498 }
 499
 500 static void wait_for_freeze(void)
 501 {
 502 #ifdef  CONFIG_X86
 503         /* No delay is needed if we are in guest */
 504         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 505                 return;
 506 #endif
 507         /* Dummy wait op - must do something useless after P_LVL2 read
 508            because chipsets cannot guarantee that STPCLK# signal
 509            gets asserted in time to freeze execution properly. */
 510         inl(acpi_gbl_FADT.xpm_timer_block.address);
 511 }
 512
 513 /**
 514  * acpi_idle_do_entry - enter idle state using the appropriate method
 515  * @cx: cstate data
 516  *
 517  * Caller disables interrupt before call and enables interrupt after return.
 518  */
 519 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 520 {
 521         if (cx->entry_method == ACPI_CSTATE_FFH) {
 522                 /* Call into architectural FFH based C-state */
 523                 acpi_processor_ffh_cstate_enter(cx);
 524         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 525                 acpi_safe_halt();
 526         } else {
 527                 /* IO port based C-state */
 528                 inb(cx->address);
 529                 wait_for_freeze();
 530         }
 531 }
 532
 533 /**
 534  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 535  * @dev: the target CPU
 536  * @index: the index of suggested state
 537  */
 538 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 539 {
 540         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 541
 542         ACPI_FLUSH_CPU_CACHE();
 543
 544         while (1) {
 545
 546                 if (cx->entry_method == ACPI_CSTATE_HALT)
 547                         safe_halt();
 548                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 549                         inb(cx->address);
 550                         wait_for_freeze();
 551                 } else
 552                         return -ENODEV;
 553         }
 554
 555         /* Never reached */
 556         return 0;
 557 }
 558
 559 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 560 {
 561         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 562                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 563 }
 564
 565 static int c3_cpu_count;
 566 static DEFINE_RAW_SPINLOCK(c3_lock);
 567
 568 /**
 569  * acpi_idle_enter_bm - enters C3 with proper BM handling
 570  * @pr: Target processor
 571  * @cx: Target state context
 572  * @timer_bc: Whether or not to change timer mode to broadcast
 573  */
 574 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 575                                struct acpi_processor_cx *cx, bool timer_bc)
 576 {
 577         acpi_unlazy_tlb(smp_processor_id());
 578
 579         /*
 580          * Must be done before busmaster disable as we might need to
 581          * access HPET !
 582          */
 583         if (timer_bc)
 584                 lapic_timer_state_broadcast(pr, cx, 1);
 585
 586         /*
 587          * disable bus master
 588          * bm_check implies we need ARB_DIS
 589          * bm_control implies whether we can do ARB_DIS
 590          *
 591          * That leaves a case where bm_check is set and bm_control is
 592          * not set. In that case we cannot do much, we enter C3
 593          * without doing anything.
 594          */
 595         if (pr->flags.bm_control) {
 596                 raw_spin_lock(&c3_lock);
 597                 c3_cpu_count++;
 598                 /* Disable bus master arbitration when all CPUs are in C3 */
 599                 if (c3_cpu_count == num_online_cpus())
 600                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 601                 raw_spin_unlock(&c3_lock);
 602         }
 603
 604         acpi_idle_do_entry(cx);
 605
 606         /* Re-enable bus master arbitration */
 607         if (pr->flags.bm_control) {
 608                 raw_spin_lock(&c3_lock);
 609                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 610                 c3_cpu_count--;
 611                 raw_spin_unlock(&c3_lock);
 612         }
 613
 614         if (timer_bc)
 615                 lapic_timer_state_broadcast(pr, cx, 0);
 616 }
 617
 618 static int acpi_idle_enter(struct cpuidle_device *dev,
 619                            struct cpuidle_driver *drv, int index)
 620 {
 621         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 622         struct acpi_processor *pr;
 623
 624         pr = __this_cpu_read(processors);
 625         if (unlikely(!pr))
 626                 return -EINVAL;
 627
 628         if (cx->type != ACPI_STATE_C1) {
 629                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 630                         index = ACPI_IDLE_STATE_START;
 631                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 632                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 633                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 634                                 acpi_idle_enter_bm(pr, cx, true);
 635                                 return index;
 636                         } else if (drv->safe_state_index >= 0) {
 637                                 index = drv->safe_state_index;
 638                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 639                         } else {
 640                                 acpi_safe_halt();
 641                                 return -EBUSY;
 642                         }
 643                 }
 644         }
 645
 646         lapic_timer_state_broadcast(pr, cx, 1);
 647
 648         if (cx->type == ACPI_STATE_C3)
 649                 ACPI_FLUSH_CPU_CACHE();
 650
 651         acpi_idle_do_entry(cx);
 652
 653         lapic_timer_state_broadcast(pr, cx, 0);
 654
 655         return index;
 656 }
 657
 658 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 659                                    struct cpuidle_driver *drv, int index)
 660 {
 661         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 662
 663         if (cx->type == ACPI_STATE_C3) {
 664                 struct acpi_processor *pr = __this_cpu_read(processors);
 665
 666                 if (unlikely(!pr))
 667                         return;
 668
 669                 if (pr->flags.bm_check) {
 670                         acpi_idle_enter_bm(pr, cx, false);
 671                         return;
 672                 } else {
 673                         ACPI_FLUSH_CPU_CACHE();
 674                 }
 675         }
 676         acpi_idle_do_entry(cx);
 677 }
 678
 679 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 680                                            struct cpuidle_device *dev)
 681 {
 682         int i, count = ACPI_IDLE_STATE_START;
 683         struct acpi_processor_cx *cx;
 684
 685         if (max_cstate == 0)
 686                 max_cstate = 1;
 687
 688         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 689                 cx = &pr->power.states[i];
 690
 691                 if (!cx->valid)
 692                         continue;
 693
 694                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 695
 696                 count++;
 697                 if (count == CPUIDLE_STATE_MAX)
 698                         break;
 699         }
 700
 701         if (!count)
 702                 return -EINVAL;
 703
 704         return 0;
 705 }
 706
 707 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 708 {
 709         int i, count;
 710         struct acpi_processor_cx *cx;
 711         struct cpuidle_state *state;
 712         struct cpuidle_driver *drv = &acpi_idle_driver;
 713
 714         if (max_cstate == 0)
 715                 max_cstate = 1;
 716
 717         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 718                 cpuidle_poll_state_init(drv);
 719                 count = 1;
 720         } else {
 721                 count = 0;
 722         }
 723
 724         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 725                 cx = &pr->power.states[i];
 726
 727                 if (!cx->valid)
 728                         continue;
 729
 730                 state = &drv->states[count];
 731                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 732                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 733                 state->exit_latency = cx->latency;
 734                 state->target_residency = cx->latency * latency_factor;
 735                 state->enter = acpi_idle_enter;
 736
 737                 state->flags = 0;
 738                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 739                         state->enter_dead = acpi_idle_play_dead;
 740                         drv->safe_state_index = count;
 741                 }
 742                 /*
 743                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 744                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 745                  * particularly interesting from the suspend-to-idle angle, so
 746                  * avoid C1 and the situations in which we may need to fall back
 747                  * to it altogether.
 748                  */
 749                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 750                         state->enter_s2idle = acpi_idle_enter_s2idle;
 751
 752                 count++;
 753                 if (count == CPUIDLE_STATE_MAX)
 754                         break;
 755         }
 756
 757         drv->state_count = count;
 758
 759         if (!count)
 760                 return -EINVAL;
 761
 762         return 0;
 763 }
 764
 765 static inline void acpi_processor_cstate_first_run_checks(void)
 766 {
 767         static int first_run;
 768
 769         if (first_run)
 770                 return;
 771         dmi_check_system(processor_power_dmi_table);
 772         max_cstate = acpi_processor_cstate_check(max_cstate);
 773         if (max_cstate < ACPI_C_STATES_MAX)
 774                 pr_notice("ACPI: processor limited to max C-state %d\n",
 775                           max_cstate);
 776         first_run++;
 777
 778         if (nocst)
 779                 return;
 780
 781         acpi_processor_claim_cst_control();
 782 }
 783 #else
 784
 785 static inline int disabled_by_idle_boot_param(void) { return 0; }
 786 static inline void acpi_processor_cstate_first_run_checks(void) { }
 787 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 788 {
 789         return -ENODEV;
 790 }
 791
 792 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 793                                            struct cpuidle_device *dev)
 794 {
 795         return -EINVAL;
 796 }
 797
 798 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 799 {
 800         return -EINVAL;
 801 }
 802
 803 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 804
 805 struct acpi_lpi_states_array {
 806         unsigned int size;
 807         unsigned int composite_states_size;
 808         struct acpi_lpi_state *entries;
 809         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 810 };
 811
 812 static int obj_get_integer(union acpi_object *obj, u32 *value)
 813 {
 814         if (obj->type != ACPI_TYPE_INTEGER)
 815                 return -EINVAL;
 816
 817         *value = obj->integer.value;
 818         return 0;
 819 }
 820
 821 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 822                                        struct acpi_lpi_states_array *info)
 823 {
 824         acpi_status status;
 825         int ret = 0;
 826         int pkg_count, state_idx = 1, loop;
 827         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 828         union acpi_object *lpi_data;
 829         struct acpi_lpi_state *lpi_state;
 830
 831         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 832         if (ACPI_FAILURE(status)) {
 833                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 834                 return -ENODEV;
 835         }
 836
 837         lpi_data = buffer.pointer;
 838
 839         /* There must be at least 4 elements = 3 elements + 1 package */
 840         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 841             lpi_data->package.count < 4) {
 842                 pr_debug("not enough elements in _LPI\n");
 843                 ret = -ENODATA;
 844                 goto end;
 845         }
 846
 847         pkg_count = lpi_data->package.elements[2].integer.value;
 848
 849         /* Validate number of power states. */
 850         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 851                 pr_debug("count given by _LPI is not valid\n");
 852                 ret = -ENODATA;
 853                 goto end;
 854         }
 855
 856         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 857         if (!lpi_state) {
 858                 ret = -ENOMEM;
 859                 goto end;
 860         }
 861
 862         info->size = pkg_count;
 863         info->entries = lpi_state;
 864
 865         /* LPI States start at index 3 */
 866         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 867                 union acpi_object *element, *pkg_elem, *obj;
 868
 869                 element = &lpi_data->package.elements[loop];
 870                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 871                         continue;
 872
 873                 pkg_elem = element->package.elements;
 874
 875                 obj = pkg_elem + 6;
 876                 if (obj->type == ACPI_TYPE_BUFFER) {
 877                         struct acpi_power_register *reg;
 878
 879                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 880                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 881                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 882                                 continue;
 883
 884                         lpi_state->address = reg->address;
 885                         lpi_state->entry_method =
 886                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 887                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 888                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 889                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 890                         lpi_state->address = obj->integer.value;
 891                 } else {
 892                         continue;
 893                 }
 894
 895                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 896
 897                 obj = pkg_elem + 9;
 898                 if (obj->type == ACPI_TYPE_STRING)
 899                         strlcpy(lpi_state->desc, obj->string.pointer,
 900                                 ACPI_CX_DESC_LEN);
 901
 902                 lpi_state->index = state_idx;
 903                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 904                         pr_debug("No min. residency found, assuming 10 us\n");
 905                         lpi_state->min_residency = 10;
 906                 }
 907
 908                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 909                         pr_debug("No wakeup residency found, assuming 10 us\n");
 910                         lpi_state->wake_latency = 10;
 911                 }
 912
 913                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 914                         lpi_state->flags = 0;
 915
 916                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 917                         lpi_state->arch_flags = 0;
 918
 919                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 920                         lpi_state->res_cnt_freq = 1;
 921
 922                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 923                         lpi_state->enable_parent_state = 0;
 924         }
 925
 926         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 927 end:
 928         kfree(buffer.pointer);
 929         return ret;
 930 }
 931
 932 /*
 933  * flat_state_cnt - the number of composite LPI states after the process of flattening
 934  */
 935 static int flat_state_cnt;
 936
 937 /**
 938  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 939  *
 940  * @local: local LPI state
 941  * @parent: parent LPI state
 942  * @result: composite LPI state
 943  */
 944 static bool combine_lpi_states(struct acpi_lpi_state *local,
 945                                struct acpi_lpi_state *parent,
 946                                struct acpi_lpi_state *result)
 947 {
 948         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
 949                 if (!parent->address) /* 0 means autopromotable */
 950                         return false;
 951                 result->address = local->address + parent->address;
 952         } else {
 953                 result->address = parent->address;
 954         }
 955
 956         result->min_residency = max(local->min_residency, parent->min_residency);
 957         result->wake_latency = local->wake_latency + parent->wake_latency;
 958         result->enable_parent_state = parent->enable_parent_state;
 959         result->entry_method = local->entry_method;
 960
 961         result->flags = parent->flags;
 962         result->arch_flags = parent->arch_flags;
 963         result->index = parent->index;
 964
 965         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
 966         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
 967         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
 968         return true;
 969 }
 970
 971 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
 972
 973 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
 974                                   struct acpi_lpi_state *t)
 975 {
 976         curr_level->composite_states[curr_level->composite_states_size++] = t;
 977 }
 978
 979 static int flatten_lpi_states(struct acpi_processor *pr,
 980                               struct acpi_lpi_states_array *curr_level,
 981                               struct acpi_lpi_states_array *prev_level)
 982 {
 983         int i, j, state_count = curr_level->size;
 984         struct acpi_lpi_state *p, *t = curr_level->entries;
 985
 986         curr_level->composite_states_size = 0;
 987         for (j = 0; j < state_count; j++, t++) {
 988                 struct acpi_lpi_state *flpi;
 989
 990                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
 991                         continue;
 992
 993                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
 994                         pr_warn("Limiting number of LPI states to max (%d)\n",
 995                                 ACPI_PROCESSOR_MAX_POWER);
 996                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 997                         break;
 998                 }
 999
1000                 flpi = &pr->power.lpi_states[flat_state_cnt];
1001
1002                 if (!prev_level) { /* leaf/processor node */
1003                         memcpy(flpi, t, sizeof(*t));
1004                         stash_composite_state(curr_level, flpi);
1005                         flat_state_cnt++;
1006                         continue;
1007                 }
1008
1009                 for (i = 0; i < prev_level->composite_states_size; i++) {
1010                         p = prev_level->composite_states[i];
1011                         if (t->index <= p->enable_parent_state &&
1012                             combine_lpi_states(p, t, flpi)) {
1013                                 stash_composite_state(curr_level, flpi);
1014                                 flat_state_cnt++;
1015                                 flpi++;
1016                         }
1017                 }
1018         }
1019
1020         kfree(curr_level->entries);
1021         return 0;
1022 }
1023
1024 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1025 {
1026         int ret, i;
1027         acpi_status status;
1028         acpi_handle handle = pr->handle, pr_ahandle;
1029         struct acpi_device *d = NULL;
1030         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1031
1032         if (!osc_pc_lpi_support_confirmed)
1033                 return -EOPNOTSUPP;
1034
1035         if (!acpi_has_method(handle, "_LPI"))
1036                 return -EINVAL;
1037
1038         flat_state_cnt = 0;
1039         prev = &info[0];
1040         curr = &info[1];
1041         handle = pr->handle;
1042         ret = acpi_processor_evaluate_lpi(handle, prev);
1043         if (ret)
1044                 return ret;
1045         flatten_lpi_states(pr, prev, NULL);
1046
1047         status = acpi_get_parent(handle, &pr_ahandle);
1048         while (ACPI_SUCCESS(status)) {
1049                 acpi_bus_get_device(pr_ahandle, &d);
1050                 handle = pr_ahandle;
1051
1052                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1053                         break;
1054
1055                 /* can be optional ? */
1056                 if (!acpi_has_method(handle, "_LPI"))
1057                         break;
1058
1059                 ret = acpi_processor_evaluate_lpi(handle, curr);
1060                 if (ret)
1061                         break;
1062
1063                 /* flatten all the LPI states in this level of hierarchy */
1064                 flatten_lpi_states(pr, curr, prev);
1065
1066                 tmp = prev, prev = curr, curr = tmp;
1067
1068                 status = acpi_get_parent(handle, &pr_ahandle);
1069         }
1070
1071         pr->power.count = flat_state_cnt;
1072         /* reset the index after flattening */
1073         for (i = 0; i < pr->power.count; i++)
1074                 pr->power.lpi_states[i].index = i;
1075
1076         /* Tell driver that _LPI is supported. */
1077         pr->flags.has_lpi = 1;
1078         pr->flags.power = 1;
1079
1080         return 0;
1081 }
1082
1083 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1084 {
1085         return -ENODEV;
1086 }
1087
1088 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1089 {
1090         return -ENODEV;
1091 }
1092
1093 /**
1094  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1095  * @dev: the target CPU
1096  * @drv: cpuidle driver containing cpuidle state info
1097  * @index: index of target state
1098  *
1099  * Return: 0 for success or negative value for error
1100  */
1101 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1102                                struct cpuidle_driver *drv, int index)
1103 {
1104         struct acpi_processor *pr;
1105         struct acpi_lpi_state *lpi;
1106
1107         pr = __this_cpu_read(processors);
1108
1109         if (unlikely(!pr))
1110                 return -EINVAL;
1111
1112         lpi = &pr->power.lpi_states[index];
1113         if (lpi->entry_method == ACPI_CSTATE_FFH)
1114                 return acpi_processor_ffh_lpi_enter(lpi);
1115
1116         return -EINVAL;
1117 }
1118
1119 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1120 {
1121         int i;
1122         struct acpi_lpi_state *lpi;
1123         struct cpuidle_state *state;
1124         struct cpuidle_driver *drv = &acpi_idle_driver;
1125
1126         if (!pr->flags.has_lpi)
1127                 return -EOPNOTSUPP;
1128
1129         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1130                 lpi = &pr->power.lpi_states[i];
1131
1132                 state = &drv->states[i];
1133                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1134                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1135                 state->exit_latency = lpi->wake_latency;
1136                 state->target_residency = lpi->min_residency;
1137                 if (lpi->arch_flags)
1138                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1139                 state->enter = acpi_idle_lpi_enter;
1140                 drv->safe_state_index = i;
1141         }
1142
1143         drv->state_count = i;
1144
1145         return 0;
1146 }
1147
1148 /**
1149  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1150  * global state data i.e. idle routines
1151  *
1152  * @pr: the ACPI processor
1153  */
1154 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1155 {
1156         int i;
1157         struct cpuidle_driver *drv = &acpi_idle_driver;
1158
1159         if (!pr->flags.power_setup_done || !pr->flags.power)
1160                 return -EINVAL;
1161
1162         drv->safe_state_index = -1;
1163         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1164                 drv->states[i].name[0] = '\0';
1165                 drv->states[i].desc[0] = '\0';
1166         }
1167
1168         if (pr->flags.has_lpi)
1169                 return acpi_processor_setup_lpi_states(pr);
1170
1171         return acpi_processor_setup_cstates(pr);
1172 }
1173
1174 /**
1175  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1176  * device i.e. per-cpu data
1177  *
1178  * @pr: the ACPI processor
1179  * @dev : the cpuidle device
1180  */
1181 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1182                                             struct cpuidle_device *dev)
1183 {
1184         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1185                 return -EINVAL;
1186
1187         dev->cpu = pr->id;
1188         if (pr->flags.has_lpi)
1189                 return acpi_processor_ffh_lpi_probe(pr->id);
1190
1191         return acpi_processor_setup_cpuidle_cx(pr, dev);
1192 }
1193
1194 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1195 {
1196         int ret;
1197
1198         ret = acpi_processor_get_lpi_info(pr);
1199         if (ret)
1200                 ret = acpi_processor_get_cstate_info(pr);
1201
1202         return ret;
1203 }
1204
1205 int acpi_processor_hotplug(struct acpi_processor *pr)
1206 {
1207         int ret = 0;
1208         struct cpuidle_device *dev;
1209
1210         if (disabled_by_idle_boot_param())
1211                 return 0;
1212
1213         if (!pr->flags.power_setup_done)
1214                 return -ENODEV;
1215
1216         dev = per_cpu(acpi_cpuidle_device, pr->id);
1217         cpuidle_pause_and_lock();
1218         cpuidle_disable_device(dev);
1219         ret = acpi_processor_get_power_info(pr);
1220         if (!ret && pr->flags.power) {
1221                 acpi_processor_setup_cpuidle_dev(pr, dev);
1222                 ret = cpuidle_enable_device(dev);
1223         }
1224         cpuidle_resume_and_unlock();
1225
1226         return ret;
1227 }
1228
1229 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1230 {
1231         int cpu;
1232         struct acpi_processor *_pr;
1233         struct cpuidle_device *dev;
1234
1235         if (disabled_by_idle_boot_param())
1236                 return 0;
1237
1238         if (!pr->flags.power_setup_done)
1239                 return -ENODEV;
1240
1241         /*
1242          * FIXME:  Design the ACPI notification to make it once per
1243          * system instead of once per-cpu.  This condition is a hack
1244          * to make the code that updates C-States be called once.
1245          */
1246
1247         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1248
1249                 /* Protect against cpu-hotplug */
1250                 get_online_cpus();
1251                 cpuidle_pause_and_lock();
1252
1253                 /* Disable all cpuidle devices */
1254                 for_each_online_cpu(cpu) {
1255                         _pr = per_cpu(processors, cpu);
1256                         if (!_pr || !_pr->flags.power_setup_done)
1257                                 continue;
1258                         dev = per_cpu(acpi_cpuidle_device, cpu);
1259                         cpuidle_disable_device(dev);
1260                 }
1261
1262                 /* Populate Updated C-state information */
1263                 acpi_processor_get_power_info(pr);
1264                 acpi_processor_setup_cpuidle_states(pr);
1265
1266                 /* Enable all cpuidle devices */
1267                 for_each_online_cpu(cpu) {
1268                         _pr = per_cpu(processors, cpu);
1269                         if (!_pr || !_pr->flags.power_setup_done)
1270                                 continue;
1271                         acpi_processor_get_power_info(_pr);
1272                         if (_pr->flags.power) {
1273                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1274                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1275                                 cpuidle_enable_device(dev);
1276                         }
1277                 }
1278                 cpuidle_resume_and_unlock();
1279                 put_online_cpus();
1280         }
1281
1282         return 0;
1283 }
1284
1285 static int acpi_processor_registered;
1286
1287 int acpi_processor_power_init(struct acpi_processor *pr)
1288 {
1289         int retval;
1290         struct cpuidle_device *dev;
1291
1292         if (disabled_by_idle_boot_param())
1293                 return 0;
1294
1295         acpi_processor_cstate_first_run_checks();
1296
1297         if (!acpi_processor_get_power_info(pr))
1298                 pr->flags.power_setup_done = 1;
1299
1300         /*
1301          * Install the idle handler if processor power management is supported.
1302          * Note that we use previously set idle handler will be used on
1303          * platforms that only support C1.
1304          */
1305         if (pr->flags.power) {
1306                 /* Register acpi_idle_driver if not already registered */
1307                 if (!acpi_processor_registered) {
1308                         acpi_processor_setup_cpuidle_states(pr);
1309                         retval = cpuidle_register_driver(&acpi_idle_driver);
1310                         if (retval)
1311                                 return retval;
1312                         pr_debug("%s registered with cpuidle\n",
1313                                  acpi_idle_driver.name);
1314                 }
1315
1316                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1317                 if (!dev)
1318                         return -ENOMEM;
1319                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1320
1321                 acpi_processor_setup_cpuidle_dev(pr, dev);
1322
1323                 /* Register per-cpu cpuidle_device. Cpuidle driver
1324                  * must already be registered before registering device
1325                  */
1326                 retval = cpuidle_register_device(dev);
1327                 if (retval) {
1328                         if (acpi_processor_registered == 0)
1329                                 cpuidle_unregister_driver(&acpi_idle_driver);
1330                         return retval;
1331                 }
1332                 acpi_processor_registered++;
1333         }
1334         return 0;
1335 }
1336
1337 int acpi_processor_power_exit(struct acpi_processor *pr)
1338 {
1339         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1340
1341         if (disabled_by_idle_boot_param())
1342                 return 0;
1343
1344         if (pr->flags.power) {
1345                 cpuidle_unregister_device(dev);
1346                 acpi_processor_registered--;
1347                 if (acpi_processor_registered == 0)
1348                         cpuidle_unregister_driver(&acpi_idle_driver);
1349         }
1350
1351         pr->flags.power_setup_done = 0;
1352         return 0;
1353 }