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/sort.h>
  20 #include <linux/tick.h>
  21 #include <linux/cpuidle.h>
  22 #include <linux/cpu.h>
  23 #include <linux/minmax.h>
  24 #include <linux/perf_event.h>
  25 #include <acpi/processor.h>
  26 #include <linux/context_tracking.h>
  27
  28 /*
  29  * Include the apic definitions for x86 to have the APIC timer related defines
  30  * available also for UP (on SMP it gets magically included via linux/smp.h).
  31  * asm/acpi.h is not an option, as it would require more include magic. Also
  32  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  33  */
  34 #ifdef CONFIG_X86
  35 #include <asm/apic.h>
  36 #include <asm/cpu.h>
  37 #endif
  38
  39 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  40
  41 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  42 module_param(max_cstate, uint, 0400);
  43 static bool nocst __read_mostly;
  44 module_param(nocst, bool, 0400);
  45 static bool bm_check_disable __read_mostly;
  46 module_param(bm_check_disable, bool, 0400);
  47
  48 static unsigned int latency_factor __read_mostly = 2;
  49 module_param(latency_factor, uint, 0644);
  50
  51 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  52
  53 struct cpuidle_driver acpi_idle_driver = {
  54         .name =         "acpi_idle",
  55         .owner =        THIS_MODULE,
  56 };
  57
  58 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  59 static
  60 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  61
  62 static int disabled_by_idle_boot_param(void)
  63 {
  64         return boot_option_idle_override == IDLE_POLL ||
  65                 boot_option_idle_override == IDLE_HALT;
  66 }
  67
  68 /*
  69  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  70  * For now disable this. Probably a bug somewhere else.
  71  *
  72  * To skip this limit, boot/load with a large max_cstate limit.
  73  */
  74 static int set_max_cstate(const struct dmi_system_id *id)
  75 {
  76         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  77                 return 0;
  78
  79         pr_notice("%s detected - limiting to C%ld max_cstate."
  80                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  81                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  82
  83         max_cstate = (long)id->driver_data;
  84
  85         return 0;
  86 }
  87
  88 static const struct dmi_system_id processor_power_dmi_table[] = {
  89         { set_max_cstate, "Clevo 5600D", {
  90           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  91           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  92          (void *)2},
  93         { set_max_cstate, "Pavilion zv5000", {
  94           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  95           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  96          (void *)1},
  97         { set_max_cstate, "Asus L8400B", {
  98           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  99           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 100          (void *)1},
 101         {},
 102 };
 103
 104
 105 /*
 106  * Callers should disable interrupts before the call and enable
 107  * interrupts after return.
 108  */
 109 static void __cpuidle acpi_safe_halt(void)
 110 {
 111         if (!tif_need_resched()) {
 112                 safe_halt();
 113                 local_irq_disable();
 114         }
 115 }
 116
 117 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 118
 119 /*
 120  * Some BIOS implementations switch to C3 in the published C2 state.
 121  * This seems to be a common problem on AMD boxen, but other vendors
 122  * are affected too. We pick the most conservative approach: we assume
 123  * that the local APIC stops in both C2 and C3.
 124  */
 125 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 126                                    struct acpi_processor_cx *cx)
 127 {
 128         struct acpi_processor_power *pwr = &pr->power;
 129         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 130
 131         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 132                 return;
 133
 134         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 135                 type = ACPI_STATE_C1;
 136
 137         /*
 138          * Check, if one of the previous states already marked the lapic
 139          * unstable
 140          */
 141         if (pwr->timer_broadcast_on_state < state)
 142                 return;
 143
 144         if (cx->type >= type)
 145                 pr->power.timer_broadcast_on_state = state;
 146 }
 147
 148 static void __lapic_timer_propagate_broadcast(void *arg)
 149 {
 150         struct acpi_processor *pr = (struct acpi_processor *) arg;
 151
 152         if (pr->power.timer_broadcast_on_state < INT_MAX)
 153                 tick_broadcast_enable();
 154         else
 155                 tick_broadcast_disable();
 156 }
 157
 158 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 159 {
 160         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 161                                  (void *)pr, 1);
 162 }
 163
 164 /* Power(C) State timer broadcast control */
 165 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 166                                         struct acpi_processor_cx *cx)
 167 {
 168         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 169 }
 170
 171 #else
 172
 173 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 174                                    struct acpi_processor_cx *cstate) { }
 175 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 176
 177 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 178                                         struct acpi_processor_cx *cx)
 179 {
 180         return false;
 181 }
 182
 183 #endif
 184
 185 #if defined(CONFIG_X86)
 186 static void tsc_check_state(int state)
 187 {
 188         switch (boot_cpu_data.x86_vendor) {
 189         case X86_VENDOR_HYGON:
 190         case X86_VENDOR_AMD:
 191         case X86_VENDOR_INTEL:
 192         case X86_VENDOR_CENTAUR:
 193         case X86_VENDOR_ZHAOXIN:
 194                 /*
 195                  * AMD Fam10h TSC will tick in all
 196                  * C/P/S0/S1 states when this bit is set.
 197                  */
 198                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 199                         return;
 200                 fallthrough;
 201         default:
 202                 /* TSC could halt in idle, so notify users */
 203                 if (state > ACPI_STATE_C1)
 204                         mark_tsc_unstable("TSC halts in idle");
 205         }
 206 }
 207 #else
 208 static void tsc_check_state(int state) { return; }
 209 #endif
 210
 211 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 212 {
 213
 214         if (!pr->pblk)
 215                 return -ENODEV;
 216
 217         /* if info is obtained from pblk/fadt, type equals state */
 218         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 219         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 220
 221 #ifndef CONFIG_HOTPLUG_CPU
 222         /*
 223          * Check for P_LVL2_UP flag before entering C2 and above on
 224          * an SMP system.
 225          */
 226         if ((num_online_cpus() > 1) &&
 227             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 228                 return -ENODEV;
 229 #endif
 230
 231         /* determine C2 and C3 address from pblk */
 232         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 233         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 234
 235         /* determine latencies from FADT */
 236         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 237         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 238
 239         /*
 240          * FADT specified C2 latency must be less than or equal to
 241          * 100 microseconds.
 242          */
 243         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 244                 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n",
 245                                   acpi_gbl_FADT.c2_latency);
 246                 /* invalidate C2 */
 247                 pr->power.states[ACPI_STATE_C2].address = 0;
 248         }
 249
 250         /*
 251          * FADT supplied C3 latency must be less than or equal to
 252          * 1000 microseconds.
 253          */
 254         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 255                 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n",
 256                                   acpi_gbl_FADT.c3_latency);
 257                 /* invalidate C3 */
 258                 pr->power.states[ACPI_STATE_C3].address = 0;
 259         }
 260
 261         acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n",
 262                           pr->power.states[ACPI_STATE_C2].address,
 263                           pr->power.states[ACPI_STATE_C3].address);
 264
 265         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 266                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 267                          pr->power.states[ACPI_STATE_C2].address);
 268         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 269                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 270                          pr->power.states[ACPI_STATE_C3].address);
 271
 272         return 0;
 273 }
 274
 275 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 276 {
 277         if (!pr->power.states[ACPI_STATE_C1].valid) {
 278                 /* set the first C-State to C1 */
 279                 /* all processors need to support C1 */
 280                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 281                 pr->power.states[ACPI_STATE_C1].valid = 1;
 282                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 283
 284                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 285                          ACPI_CX_DESC_LEN, "ACPI HLT");
 286         }
 287         /* the C0 state only exists as a filler in our array */
 288         pr->power.states[ACPI_STATE_C0].valid = 1;
 289         return 0;
 290 }
 291
 292 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 293 {
 294         int ret;
 295
 296         if (nocst)
 297                 return -ENODEV;
 298
 299         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 300         if (ret)
 301                 return ret;
 302
 303         if (!pr->power.count)
 304                 return -EFAULT;
 305
 306         pr->flags.has_cst = 1;
 307         return 0;
 308 }
 309
 310 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 311                                            struct acpi_processor_cx *cx)
 312 {
 313         static int bm_check_flag = -1;
 314         static int bm_control_flag = -1;
 315
 316
 317         if (!cx->address)
 318                 return;
 319
 320         /*
 321          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 322          * DMA transfers are used by any ISA device to avoid livelock.
 323          * Note that we could disable Type-F DMA (as recommended by
 324          * the erratum), but this is known to disrupt certain ISA
 325          * devices thus we take the conservative approach.
 326          */
 327         else if (errata.piix4.fdma) {
 328                 acpi_handle_debug(pr->handle,
 329                                   "C3 not supported on PIIX4 with Type-F DMA\n");
 330                 return;
 331         }
 332
 333         /* All the logic here assumes flags.bm_check is same across all CPUs */
 334         if (bm_check_flag == -1) {
 335                 /* Determine whether bm_check is needed based on CPU  */
 336                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 337                 bm_check_flag = pr->flags.bm_check;
 338                 bm_control_flag = pr->flags.bm_control;
 339         } else {
 340                 pr->flags.bm_check = bm_check_flag;
 341                 pr->flags.bm_control = bm_control_flag;
 342         }
 343
 344         if (pr->flags.bm_check) {
 345                 if (!pr->flags.bm_control) {
 346                         if (pr->flags.has_cst != 1) {
 347                                 /* bus mastering control is necessary */
 348                                 acpi_handle_debug(pr->handle,
 349                                                   "C3 support requires BM control\n");
 350                                 return;
 351                         } else {
 352                                 /* Here we enter C3 without bus mastering */
 353                                 acpi_handle_debug(pr->handle,
 354                                                   "C3 support without BM control\n");
 355                         }
 356                 }
 357         } else {
 358                 /*
 359                  * WBINVD should be set in fadt, for C3 state to be
 360                  * supported on when bm_check is not required.
 361                  */
 362                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 363                         acpi_handle_debug(pr->handle,
 364                                           "Cache invalidation should work properly"
 365                                           " for C3 to be enabled on SMP systems\n");
 366                         return;
 367                 }
 368         }
 369
 370         /*
 371          * Otherwise we've met all of our C3 requirements.
 372          * Normalize the C3 latency to expidite policy.  Enable
 373          * checking of bus mastering status (bm_check) so we can
 374          * use this in our C3 policy
 375          */
 376         cx->valid = 1;
 377
 378         /*
 379          * On older chipsets, BM_RLD needs to be set
 380          * in order for Bus Master activity to wake the
 381          * system from C3.  Newer chipsets handle DMA
 382          * during C3 automatically and BM_RLD is a NOP.
 383          * In either case, the proper way to
 384          * handle BM_RLD is to set it and leave it set.
 385          */
 386         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 387
 388         return;
 389 }
 390
 391 static int acpi_cst_latency_cmp(const void *a, const void *b)
 392 {
 393         const struct acpi_processor_cx *x = a, *y = b;
 394
 395         if (!(x->valid && y->valid))
 396                 return 0;
 397         if (x->latency > y->latency)
 398                 return 1;
 399         if (x->latency < y->latency)
 400                 return -1;
 401         return 0;
 402 }
 403 static void acpi_cst_latency_swap(void *a, void *b, int n)
 404 {
 405         struct acpi_processor_cx *x = a, *y = b;
 406
 407         if (!(x->valid && y->valid))
 408                 return;
 409         swap(x->latency, y->latency);
 410 }
 411
 412 static int acpi_processor_power_verify(struct acpi_processor *pr)
 413 {
 414         unsigned int i;
 415         unsigned int working = 0;
 416         unsigned int last_latency = 0;
 417         unsigned int last_type = 0;
 418         bool buggy_latency = false;
 419
 420         pr->power.timer_broadcast_on_state = INT_MAX;
 421
 422         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 423                 struct acpi_processor_cx *cx = &pr->power.states[i];
 424
 425                 switch (cx->type) {
 426                 case ACPI_STATE_C1:
 427                         cx->valid = 1;
 428                         break;
 429
 430                 case ACPI_STATE_C2:
 431                         if (!cx->address)
 432                                 break;
 433                         cx->valid = 1;
 434                         break;
 435
 436                 case ACPI_STATE_C3:
 437                         acpi_processor_power_verify_c3(pr, cx);
 438                         break;
 439                 }
 440                 if (!cx->valid)
 441                         continue;
 442                 if (cx->type >= last_type && cx->latency < last_latency)
 443                         buggy_latency = true;
 444                 last_latency = cx->latency;
 445                 last_type = cx->type;
 446
 447                 lapic_timer_check_state(i, pr, cx);
 448                 tsc_check_state(cx->type);
 449                 working++;
 450         }
 451
 452         if (buggy_latency) {
 453                 pr_notice("FW issue: working around C-state latencies out of order\n");
 454                 sort(&pr->power.states[1], max_cstate,
 455                      sizeof(struct acpi_processor_cx),
 456                      acpi_cst_latency_cmp,
 457                      acpi_cst_latency_swap);
 458         }
 459
 460         lapic_timer_propagate_broadcast(pr);
 461
 462         return (working);
 463 }
 464
 465 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 466 {
 467         unsigned int i;
 468         int result;
 469
 470
 471         /* NOTE: the idle thread may not be running while calling
 472          * this function */
 473
 474         /* Zero initialize all the C-states info. */
 475         memset(pr->power.states, 0, sizeof(pr->power.states));
 476
 477         result = acpi_processor_get_power_info_cst(pr);
 478         if (result == -ENODEV)
 479                 result = acpi_processor_get_power_info_fadt(pr);
 480
 481         if (result)
 482                 return result;
 483
 484         acpi_processor_get_power_info_default(pr);
 485
 486         pr->power.count = acpi_processor_power_verify(pr);
 487
 488         /*
 489          * if one state of type C2 or C3 is available, mark this
 490          * CPU as being "idle manageable"
 491          */
 492         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 493                 if (pr->power.states[i].valid) {
 494                         pr->power.count = i;
 495                         pr->flags.power = 1;
 496                 }
 497         }
 498
 499         return 0;
 500 }
 501
 502 /**
 503  * acpi_idle_bm_check - checks if bus master activity was detected
 504  */
 505 static int acpi_idle_bm_check(void)
 506 {
 507         u32 bm_status = 0;
 508
 509         if (bm_check_disable)
 510                 return 0;
 511
 512         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 513         if (bm_status)
 514                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 515         /*
 516          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 517          * the true state of bus mastering activity; forcing us to
 518          * manually check the BMIDEA bit of each IDE channel.
 519          */
 520         else if (errata.piix4.bmisx) {
 521                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 522                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 523                         bm_status = 1;
 524         }
 525         return bm_status;
 526 }
 527
 528 static void wait_for_freeze(void)
 529 {
 530 #ifdef  CONFIG_X86
 531         /* No delay is needed if we are in guest */
 532         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 533                 return;
 534 #endif
 535         /* Dummy wait op - must do something useless after P_LVL2 read
 536            because chipsets cannot guarantee that STPCLK# signal
 537            gets asserted in time to freeze execution properly. */
 538         inl(acpi_gbl_FADT.xpm_timer_block.address);
 539 }
 540
 541 /**
 542  * acpi_idle_do_entry - enter idle state using the appropriate method
 543  * @cx: cstate data
 544  *
 545  * Caller disables interrupt before call and enables interrupt after return.
 546  */
 547 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 548 {
 549         perf_lopwr_cb(true);
 550
 551         if (cx->entry_method == ACPI_CSTATE_FFH) {
 552                 /* Call into architectural FFH based C-state */
 553                 acpi_processor_ffh_cstate_enter(cx);
 554         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 555                 acpi_safe_halt();
 556         } else {
 557                 /* IO port based C-state */
 558                 inb(cx->address);
 559                 wait_for_freeze();
 560         }
 561
 562         perf_lopwr_cb(false);
 563 }
 564
 565 /**
 566  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 567  * @dev: the target CPU
 568  * @index: the index of suggested state
 569  */
 570 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 571 {
 572         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 573
 574         ACPI_FLUSH_CPU_CACHE();
 575
 576         while (1) {
 577
 578                 if (cx->entry_method == ACPI_CSTATE_HALT)
 579                         safe_halt();
 580                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 581                         inb(cx->address);
 582                         wait_for_freeze();
 583                 } else
 584                         return -ENODEV;
 585
 586 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
 587                 cond_wakeup_cpu0();
 588 #endif
 589         }
 590
 591         /* Never reached */
 592         return 0;
 593 }
 594
 595 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 596 {
 597         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 598                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 599 }
 600
 601 static int c3_cpu_count;
 602 static DEFINE_RAW_SPINLOCK(c3_lock);
 603
 604 /**
 605  * acpi_idle_enter_bm - enters C3 with proper BM handling
 606  * @drv: cpuidle driver
 607  * @pr: Target processor
 608  * @cx: Target state context
 609  * @index: index of target state
 610  */
 611 static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv,
 612                                struct acpi_processor *pr,
 613                                struct acpi_processor_cx *cx,
 614                                int index)
 615 {
 616         static struct acpi_processor_cx safe_cx = {
 617                 .entry_method = ACPI_CSTATE_HALT,
 618         };
 619
 620         /*
 621          * disable bus master
 622          * bm_check implies we need ARB_DIS
 623          * bm_control implies whether we can do ARB_DIS
 624          *
 625          * That leaves a case where bm_check is set and bm_control is not set.
 626          * In that case we cannot do much, we enter C3 without doing anything.
 627          */
 628         bool dis_bm = pr->flags.bm_control;
 629
 630         /* If we can skip BM, demote to a safe state. */
 631         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 632                 dis_bm = false;
 633                 index = drv->safe_state_index;
 634                 if (index >= 0) {
 635                         cx = this_cpu_read(acpi_cstate[index]);
 636                 } else {
 637                         cx = &safe_cx;
 638                         index = -EBUSY;
 639                 }
 640         }
 641
 642         if (dis_bm) {
 643                 raw_spin_lock(&c3_lock);
 644                 c3_cpu_count++;
 645                 /* Disable bus master arbitration when all CPUs are in C3 */
 646                 if (c3_cpu_count == num_online_cpus())
 647                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 648                 raw_spin_unlock(&c3_lock);
 649         }
 650
 651         ct_idle_enter();
 652
 653         acpi_idle_do_entry(cx);
 654
 655         ct_idle_exit();
 656
 657         /* Re-enable bus master arbitration */
 658         if (dis_bm) {
 659                 raw_spin_lock(&c3_lock);
 660                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 661                 c3_cpu_count--;
 662                 raw_spin_unlock(&c3_lock);
 663         }
 664
 665         return index;
 666 }
 667
 668 static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev,
 669                            struct cpuidle_driver *drv, int index)
 670 {
 671         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 672         struct acpi_processor *pr;
 673
 674         pr = __this_cpu_read(processors);
 675         if (unlikely(!pr))
 676                 return -EINVAL;
 677
 678         if (cx->type != ACPI_STATE_C1) {
 679                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 680                         return acpi_idle_enter_bm(drv, pr, cx, index);
 681
 682                 /* C2 to C1 demotion. */
 683                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 684                         index = ACPI_IDLE_STATE_START;
 685                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 686                 }
 687         }
 688
 689         if (cx->type == ACPI_STATE_C3)
 690                 ACPI_FLUSH_CPU_CACHE();
 691
 692         acpi_idle_do_entry(cx);
 693
 694         return index;
 695 }
 696
 697 static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 698                                   struct cpuidle_driver *drv, int index)
 699 {
 700         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 701
 702         if (cx->type == ACPI_STATE_C3) {
 703                 struct acpi_processor *pr = __this_cpu_read(processors);
 704
 705                 if (unlikely(!pr))
 706                         return 0;
 707
 708                 if (pr->flags.bm_check) {
 709                         u8 bm_sts_skip = cx->bm_sts_skip;
 710
 711                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 712                         cx->bm_sts_skip = 1;
 713                         acpi_idle_enter_bm(drv, pr, cx, index);
 714                         cx->bm_sts_skip = bm_sts_skip;
 715
 716                         return 0;
 717                 } else {
 718                         ACPI_FLUSH_CPU_CACHE();
 719                 }
 720         }
 721         acpi_idle_do_entry(cx);
 722
 723         return 0;
 724 }
 725
 726 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 727                                            struct cpuidle_device *dev)
 728 {
 729         int i, count = ACPI_IDLE_STATE_START;
 730         struct acpi_processor_cx *cx;
 731         struct cpuidle_state *state;
 732
 733         if (max_cstate == 0)
 734                 max_cstate = 1;
 735
 736         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 737                 state = &acpi_idle_driver.states[count];
 738                 cx = &pr->power.states[i];
 739
 740                 if (!cx->valid)
 741                         continue;
 742
 743                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 744
 745                 if (lapic_timer_needs_broadcast(pr, cx))
 746                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 747
 748                 if (cx->type == ACPI_STATE_C3) {
 749                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 750                         if (pr->flags.bm_check)
 751                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 752                 }
 753
 754                 count++;
 755                 if (count == CPUIDLE_STATE_MAX)
 756                         break;
 757         }
 758
 759         if (!count)
 760                 return -EINVAL;
 761
 762         return 0;
 763 }
 764
 765 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 766 {
 767         int i, count;
 768         struct acpi_processor_cx *cx;
 769         struct cpuidle_state *state;
 770         struct cpuidle_driver *drv = &acpi_idle_driver;
 771
 772         if (max_cstate == 0)
 773                 max_cstate = 1;
 774
 775         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 776                 cpuidle_poll_state_init(drv);
 777                 count = 1;
 778         } else {
 779                 count = 0;
 780         }
 781
 782         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 783                 cx = &pr->power.states[i];
 784
 785                 if (!cx->valid)
 786                         continue;
 787
 788                 state = &drv->states[count];
 789                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 790                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 791                 state->exit_latency = cx->latency;
 792                 state->target_residency = cx->latency * latency_factor;
 793                 state->enter = acpi_idle_enter;
 794
 795                 state->flags = 0;
 796                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 ||
 797                     cx->type == ACPI_STATE_C3) {
 798                         state->enter_dead = acpi_idle_play_dead;
 799                         if (cx->type != ACPI_STATE_C3)
 800                                 drv->safe_state_index = count;
 801                 }
 802                 /*
 803                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 804                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 805                  * particularly interesting from the suspend-to-idle angle, so
 806                  * avoid C1 and the situations in which we may need to fall back
 807                  * to it altogether.
 808                  */
 809                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 810                         state->enter_s2idle = acpi_idle_enter_s2idle;
 811
 812                 count++;
 813                 if (count == CPUIDLE_STATE_MAX)
 814                         break;
 815         }
 816
 817         drv->state_count = count;
 818
 819         if (!count)
 820                 return -EINVAL;
 821
 822         return 0;
 823 }
 824
 825 static inline void acpi_processor_cstate_first_run_checks(void)
 826 {
 827         static int first_run;
 828
 829         if (first_run)
 830                 return;
 831         dmi_check_system(processor_power_dmi_table);
 832         max_cstate = acpi_processor_cstate_check(max_cstate);
 833         if (max_cstate < ACPI_C_STATES_MAX)
 834                 pr_notice("processor limited to max C-state %d\n", max_cstate);
 835
 836         first_run++;
 837
 838         if (nocst)
 839                 return;
 840
 841         acpi_processor_claim_cst_control();
 842 }
 843 #else
 844
 845 static inline int disabled_by_idle_boot_param(void) { return 0; }
 846 static inline void acpi_processor_cstate_first_run_checks(void) { }
 847 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 848 {
 849         return -ENODEV;
 850 }
 851
 852 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 853                                            struct cpuidle_device *dev)
 854 {
 855         return -EINVAL;
 856 }
 857
 858 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 859 {
 860         return -EINVAL;
 861 }
 862
 863 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 864
 865 struct acpi_lpi_states_array {
 866         unsigned int size;
 867         unsigned int composite_states_size;
 868         struct acpi_lpi_state *entries;
 869         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 870 };
 871
 872 static int obj_get_integer(union acpi_object *obj, u32 *value)
 873 {
 874         if (obj->type != ACPI_TYPE_INTEGER)
 875                 return -EINVAL;
 876
 877         *value = obj->integer.value;
 878         return 0;
 879 }
 880
 881 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 882                                        struct acpi_lpi_states_array *info)
 883 {
 884         acpi_status status;
 885         int ret = 0;
 886         int pkg_count, state_idx = 1, loop;
 887         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 888         union acpi_object *lpi_data;
 889         struct acpi_lpi_state *lpi_state;
 890
 891         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 892         if (ACPI_FAILURE(status)) {
 893                 acpi_handle_debug(handle, "No _LPI, giving up\n");
 894                 return -ENODEV;
 895         }
 896
 897         lpi_data = buffer.pointer;
 898
 899         /* There must be at least 4 elements = 3 elements + 1 package */
 900         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 901             lpi_data->package.count < 4) {
 902                 pr_debug("not enough elements in _LPI\n");
 903                 ret = -ENODATA;
 904                 goto end;
 905         }
 906
 907         pkg_count = lpi_data->package.elements[2].integer.value;
 908
 909         /* Validate number of power states. */
 910         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 911                 pr_debug("count given by _LPI is not valid\n");
 912                 ret = -ENODATA;
 913                 goto end;
 914         }
 915
 916         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 917         if (!lpi_state) {
 918                 ret = -ENOMEM;
 919                 goto end;
 920         }
 921
 922         info->size = pkg_count;
 923         info->entries = lpi_state;
 924
 925         /* LPI States start at index 3 */
 926         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 927                 union acpi_object *element, *pkg_elem, *obj;
 928
 929                 element = &lpi_data->package.elements[loop];
 930                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 931                         continue;
 932
 933                 pkg_elem = element->package.elements;
 934
 935                 obj = pkg_elem + 6;
 936                 if (obj->type == ACPI_TYPE_BUFFER) {
 937                         struct acpi_power_register *reg;
 938
 939                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 940                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 941                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 942                                 continue;
 943
 944                         lpi_state->address = reg->address;
 945                         lpi_state->entry_method =
 946                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 947                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 948                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 949                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 950                         lpi_state->address = obj->integer.value;
 951                 } else {
 952                         continue;
 953                 }
 954
 955                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 956
 957                 obj = pkg_elem + 9;
 958                 if (obj->type == ACPI_TYPE_STRING)
 959                         strlcpy(lpi_state->desc, obj->string.pointer,
 960                                 ACPI_CX_DESC_LEN);
 961
 962                 lpi_state->index = state_idx;
 963                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 964                         pr_debug("No min. residency found, assuming 10 us\n");
 965                         lpi_state->min_residency = 10;
 966                 }
 967
 968                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 969                         pr_debug("No wakeup residency found, assuming 10 us\n");
 970                         lpi_state->wake_latency = 10;
 971                 }
 972
 973                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 974                         lpi_state->flags = 0;
 975
 976                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 977                         lpi_state->arch_flags = 0;
 978
 979                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 980                         lpi_state->res_cnt_freq = 1;
 981
 982                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 983                         lpi_state->enable_parent_state = 0;
 984         }
 985
 986         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 987 end:
 988         kfree(buffer.pointer);
 989         return ret;
 990 }
 991
 992 /*
 993  * flat_state_cnt - the number of composite LPI states after the process of flattening
 994  */
 995 static int flat_state_cnt;
 996
 997 /**
 998  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 999  *
1000  * @local: local LPI state
1001  * @parent: parent LPI state
1002  * @result: composite LPI state
1003  */
1004 static bool combine_lpi_states(struct acpi_lpi_state *local,
1005                                struct acpi_lpi_state *parent,
1006                                struct acpi_lpi_state *result)
1007 {
1008         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1009                 if (!parent->address) /* 0 means autopromotable */
1010                         return false;
1011                 result->address = local->address + parent->address;
1012         } else {
1013                 result->address = parent->address;
1014         }
1015
1016         result->min_residency = max(local->min_residency, parent->min_residency);
1017         result->wake_latency = local->wake_latency + parent->wake_latency;
1018         result->enable_parent_state = parent->enable_parent_state;
1019         result->entry_method = local->entry_method;
1020
1021         result->flags = parent->flags;
1022         result->arch_flags = parent->arch_flags;
1023         result->index = parent->index;
1024
1025         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1026         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1027         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1028         return true;
1029 }
1030
1031 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1032
1033 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1034                                   struct acpi_lpi_state *t)
1035 {
1036         curr_level->composite_states[curr_level->composite_states_size++] = t;
1037 }
1038
1039 static int flatten_lpi_states(struct acpi_processor *pr,
1040                               struct acpi_lpi_states_array *curr_level,
1041                               struct acpi_lpi_states_array *prev_level)
1042 {
1043         int i, j, state_count = curr_level->size;
1044         struct acpi_lpi_state *p, *t = curr_level->entries;
1045
1046         curr_level->composite_states_size = 0;
1047         for (j = 0; j < state_count; j++, t++) {
1048                 struct acpi_lpi_state *flpi;
1049
1050                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1051                         continue;
1052
1053                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1054                         pr_warn("Limiting number of LPI states to max (%d)\n",
1055                                 ACPI_PROCESSOR_MAX_POWER);
1056                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1057                         break;
1058                 }
1059
1060                 flpi = &pr->power.lpi_states[flat_state_cnt];
1061
1062                 if (!prev_level) { /* leaf/processor node */
1063                         memcpy(flpi, t, sizeof(*t));
1064                         stash_composite_state(curr_level, flpi);
1065                         flat_state_cnt++;
1066                         continue;
1067                 }
1068
1069                 for (i = 0; i < prev_level->composite_states_size; i++) {
1070                         p = prev_level->composite_states[i];
1071                         if (t->index <= p->enable_parent_state &&
1072                             combine_lpi_states(p, t, flpi)) {
1073                                 stash_composite_state(curr_level, flpi);
1074                                 flat_state_cnt++;
1075                                 flpi++;
1076                         }
1077                 }
1078         }
1079
1080         kfree(curr_level->entries);
1081         return 0;
1082 }
1083
1084 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1085 {
1086         return -EOPNOTSUPP;
1087 }
1088
1089 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1090 {
1091         int ret, i;
1092         acpi_status status;
1093         acpi_handle handle = pr->handle, pr_ahandle;
1094         struct acpi_device *d = NULL;
1095         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1096
1097         /* make sure our architecture has support */
1098         ret = acpi_processor_ffh_lpi_probe(pr->id);
1099         if (ret == -EOPNOTSUPP)
1100                 return ret;
1101
1102         if (!osc_pc_lpi_support_confirmed)
1103                 return -EOPNOTSUPP;
1104
1105         if (!acpi_has_method(handle, "_LPI"))
1106                 return -EINVAL;
1107
1108         flat_state_cnt = 0;
1109         prev = &info[0];
1110         curr = &info[1];
1111         handle = pr->handle;
1112         ret = acpi_processor_evaluate_lpi(handle, prev);
1113         if (ret)
1114                 return ret;
1115         flatten_lpi_states(pr, prev, NULL);
1116
1117         status = acpi_get_parent(handle, &pr_ahandle);
1118         while (ACPI_SUCCESS(status)) {
1119                 d = acpi_fetch_acpi_dev(pr_ahandle);
1120                 handle = pr_ahandle;
1121
1122                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1123                         break;
1124
1125                 /* can be optional ? */
1126                 if (!acpi_has_method(handle, "_LPI"))
1127                         break;
1128
1129                 ret = acpi_processor_evaluate_lpi(handle, curr);
1130                 if (ret)
1131                         break;
1132
1133                 /* flatten all the LPI states in this level of hierarchy */
1134                 flatten_lpi_states(pr, curr, prev);
1135
1136                 tmp = prev, prev = curr, curr = tmp;
1137
1138                 status = acpi_get_parent(handle, &pr_ahandle);
1139         }
1140
1141         pr->power.count = flat_state_cnt;
1142         /* reset the index after flattening */
1143         for (i = 0; i < pr->power.count; i++)
1144                 pr->power.lpi_states[i].index = i;
1145
1146         /* Tell driver that _LPI is supported. */
1147         pr->flags.has_lpi = 1;
1148         pr->flags.power = 1;
1149
1150         return 0;
1151 }
1152
1153 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1154 {
1155         return -ENODEV;
1156 }
1157
1158 /**
1159  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1160  * @dev: the target CPU
1161  * @drv: cpuidle driver containing cpuidle state info
1162  * @index: index of target state
1163  *
1164  * Return: 0 for success or negative value for error
1165  */
1166 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1167                                struct cpuidle_driver *drv, int index)
1168 {
1169         struct acpi_processor *pr;
1170         struct acpi_lpi_state *lpi;
1171
1172         pr = __this_cpu_read(processors);
1173
1174         if (unlikely(!pr))
1175                 return -EINVAL;
1176
1177         lpi = &pr->power.lpi_states[index];
1178         if (lpi->entry_method == ACPI_CSTATE_FFH)
1179                 return acpi_processor_ffh_lpi_enter(lpi);
1180
1181         return -EINVAL;
1182 }
1183
1184 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1185 {
1186         int i;
1187         struct acpi_lpi_state *lpi;
1188         struct cpuidle_state *state;
1189         struct cpuidle_driver *drv = &acpi_idle_driver;
1190
1191         if (!pr->flags.has_lpi)
1192                 return -EOPNOTSUPP;
1193
1194         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1195                 lpi = &pr->power.lpi_states[i];
1196
1197                 state = &drv->states[i];
1198                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1199                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1200                 state->exit_latency = lpi->wake_latency;
1201                 state->target_residency = lpi->min_residency;
1202                 if (lpi->arch_flags)
1203                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1204                 state->enter = acpi_idle_lpi_enter;
1205                 drv->safe_state_index = i;
1206         }
1207
1208         drv->state_count = i;
1209
1210         return 0;
1211 }
1212
1213 /**
1214  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1215  * global state data i.e. idle routines
1216  *
1217  * @pr: the ACPI processor
1218  */
1219 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1220 {
1221         int i;
1222         struct cpuidle_driver *drv = &acpi_idle_driver;
1223
1224         if (!pr->flags.power_setup_done || !pr->flags.power)
1225                 return -EINVAL;
1226
1227         drv->safe_state_index = -1;
1228         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1229                 drv->states[i].name[0] = '\0';
1230                 drv->states[i].desc[0] = '\0';
1231         }
1232
1233         if (pr->flags.has_lpi)
1234                 return acpi_processor_setup_lpi_states(pr);
1235
1236         return acpi_processor_setup_cstates(pr);
1237 }
1238
1239 /**
1240  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1241  * device i.e. per-cpu data
1242  *
1243  * @pr: the ACPI processor
1244  * @dev : the cpuidle device
1245  */
1246 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1247                                             struct cpuidle_device *dev)
1248 {
1249         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1250                 return -EINVAL;
1251
1252         dev->cpu = pr->id;
1253         if (pr->flags.has_lpi)
1254                 return acpi_processor_ffh_lpi_probe(pr->id);
1255
1256         return acpi_processor_setup_cpuidle_cx(pr, dev);
1257 }
1258
1259 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1260 {
1261         int ret;
1262
1263         ret = acpi_processor_get_lpi_info(pr);
1264         if (ret)
1265                 ret = acpi_processor_get_cstate_info(pr);
1266
1267         return ret;
1268 }
1269
1270 int acpi_processor_hotplug(struct acpi_processor *pr)
1271 {
1272         int ret = 0;
1273         struct cpuidle_device *dev;
1274
1275         if (disabled_by_idle_boot_param())
1276                 return 0;
1277
1278         if (!pr->flags.power_setup_done)
1279                 return -ENODEV;
1280
1281         dev = per_cpu(acpi_cpuidle_device, pr->id);
1282         cpuidle_pause_and_lock();
1283         cpuidle_disable_device(dev);
1284         ret = acpi_processor_get_power_info(pr);
1285         if (!ret && pr->flags.power) {
1286                 acpi_processor_setup_cpuidle_dev(pr, dev);
1287                 ret = cpuidle_enable_device(dev);
1288         }
1289         cpuidle_resume_and_unlock();
1290
1291         return ret;
1292 }
1293
1294 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1295 {
1296         int cpu;
1297         struct acpi_processor *_pr;
1298         struct cpuidle_device *dev;
1299
1300         if (disabled_by_idle_boot_param())
1301                 return 0;
1302
1303         if (!pr->flags.power_setup_done)
1304                 return -ENODEV;
1305
1306         /*
1307          * FIXME:  Design the ACPI notification to make it once per
1308          * system instead of once per-cpu.  This condition is a hack
1309          * to make the code that updates C-States be called once.
1310          */
1311
1312         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1313
1314                 /* Protect against cpu-hotplug */
1315                 cpus_read_lock();
1316                 cpuidle_pause_and_lock();
1317
1318                 /* Disable all cpuidle devices */
1319                 for_each_online_cpu(cpu) {
1320                         _pr = per_cpu(processors, cpu);
1321                         if (!_pr || !_pr->flags.power_setup_done)
1322                                 continue;
1323                         dev = per_cpu(acpi_cpuidle_device, cpu);
1324                         cpuidle_disable_device(dev);
1325                 }
1326
1327                 /* Populate Updated C-state information */
1328                 acpi_processor_get_power_info(pr);
1329                 acpi_processor_setup_cpuidle_states(pr);
1330
1331                 /* Enable all cpuidle devices */
1332                 for_each_online_cpu(cpu) {
1333                         _pr = per_cpu(processors, cpu);
1334                         if (!_pr || !_pr->flags.power_setup_done)
1335                                 continue;
1336                         acpi_processor_get_power_info(_pr);
1337                         if (_pr->flags.power) {
1338                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1339                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1340                                 cpuidle_enable_device(dev);
1341                         }
1342                 }
1343                 cpuidle_resume_and_unlock();
1344                 cpus_read_unlock();
1345         }
1346
1347         return 0;
1348 }
1349
1350 static int acpi_processor_registered;
1351
1352 int acpi_processor_power_init(struct acpi_processor *pr)
1353 {
1354         int retval;
1355         struct cpuidle_device *dev;
1356
1357         if (disabled_by_idle_boot_param())
1358                 return 0;
1359
1360         acpi_processor_cstate_first_run_checks();
1361
1362         if (!acpi_processor_get_power_info(pr))
1363                 pr->flags.power_setup_done = 1;
1364
1365         /*
1366          * Install the idle handler if processor power management is supported.
1367          * Note that we use previously set idle handler will be used on
1368          * platforms that only support C1.
1369          */
1370         if (pr->flags.power) {
1371                 /* Register acpi_idle_driver if not already registered */
1372                 if (!acpi_processor_registered) {
1373                         acpi_processor_setup_cpuidle_states(pr);
1374                         retval = cpuidle_register_driver(&acpi_idle_driver);
1375                         if (retval)
1376                                 return retval;
1377                         pr_debug("%s registered with cpuidle\n",
1378                                  acpi_idle_driver.name);
1379                 }
1380
1381                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1382                 if (!dev)
1383                         return -ENOMEM;
1384                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1385
1386                 acpi_processor_setup_cpuidle_dev(pr, dev);
1387
1388                 /* Register per-cpu cpuidle_device. Cpuidle driver
1389                  * must already be registered before registering device
1390                  */
1391                 retval = cpuidle_register_device(dev);
1392                 if (retval) {
1393                         if (acpi_processor_registered == 0)
1394                                 cpuidle_unregister_driver(&acpi_idle_driver);
1395                         return retval;
1396                 }
1397                 acpi_processor_registered++;
1398         }
1399         return 0;
1400 }
1401
1402 int acpi_processor_power_exit(struct acpi_processor *pr)
1403 {
1404         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1405
1406         if (disabled_by_idle_boot_param())
1407                 return 0;
1408
1409         if (pr->flags.power) {
1410                 cpuidle_unregister_device(dev);
1411                 acpi_processor_registered--;
1412                 if (acpi_processor_registered == 0)
1413                         cpuidle_unregister_driver(&acpi_idle_driver);
1414         }
1415
1416         pr->flags.power_setup_done = 0;
1417         return 0;
1418 }