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 <acpi/processor.h>
  24
  25 /*
  26  * Include the apic definitions for x86 to have the APIC timer related defines
  27  * available also for UP (on SMP it gets magically included via linux/smp.h).
  28  * asm/acpi.h is not an option, as it would require more include magic. Also
  29  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  30  */
  31 #ifdef CONFIG_X86
  32 #include <asm/apic.h>
  33 #include <asm/cpu.h>
  34 #endif
  35
  36 #define ACPI_PROCESSOR_CLASS            "processor"
  37 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  38 ACPI_MODULE_NAME("processor_idle");
  39
  40 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  41
  42 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  43 module_param(max_cstate, uint, 0000);
  44 static unsigned int nocst __read_mostly;
  45 module_param(nocst, uint, 0000);
  46 static int bm_check_disable __read_mostly;
  47 module_param(bm_check_disable, uint, 0000);
  48
  49 static unsigned int latency_factor __read_mostly = 2;
  50 module_param(latency_factor, uint, 0644);
  51
  52 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  53
  54 struct cpuidle_driver acpi_idle_driver = {
  55         .name =         "acpi_idle",
  56         .owner =        THIS_MODULE,
  57 };
  58
  59 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  60 static
  61 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  62
  63 static int disabled_by_idle_boot_param(void)
  64 {
  65         return boot_option_idle_override == IDLE_POLL ||
  66                 boot_option_idle_override == IDLE_HALT;
  67 }
  68
  69 /*
  70  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  71  * For now disable this. Probably a bug somewhere else.
  72  *
  73  * To skip this limit, boot/load with a large max_cstate limit.
  74  */
  75 static int set_max_cstate(const struct dmi_system_id *id)
  76 {
  77         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  78                 return 0;
  79
  80         pr_notice("%s detected - limiting to C%ld max_cstate."
  81                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  82                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  83
  84         max_cstate = (long)id->driver_data;
  85
  86         return 0;
  87 }
  88
  89 static const struct dmi_system_id processor_power_dmi_table[] = {
  90         { set_max_cstate, "Clevo 5600D", {
  91           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  92           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  93          (void *)2},
  94         { set_max_cstate, "Pavilion zv5000", {
  95           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  96           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  97          (void *)1},
  98         { set_max_cstate, "Asus L8400B", {
  99           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 100           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 101          (void *)1},
 102         {},
 103 };
 104
 105
 106 /*
 107  * Callers should disable interrupts before the call and enable
 108  * interrupts after return.
 109  */
 110 static void __cpuidle acpi_safe_halt(void)
 111 {
 112         if (!tif_need_resched()) {
 113                 safe_halt();
 114                 local_irq_disable();
 115         }
 116 }
 117
 118 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 119
 120 /*
 121  * Some BIOS implementations switch to C3 in the published C2 state.
 122  * This seems to be a common problem on AMD boxen, but other vendors
 123  * are affected too. We pick the most conservative approach: we assume
 124  * that the local APIC stops in both C2 and C3.
 125  */
 126 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 127                                    struct acpi_processor_cx *cx)
 128 {
 129         struct acpi_processor_power *pwr = &pr->power;
 130         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 131
 132         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 133                 return;
 134
 135         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 136                 type = ACPI_STATE_C1;
 137
 138         /*
 139          * Check, if one of the previous states already marked the lapic
 140          * unstable
 141          */
 142         if (pwr->timer_broadcast_on_state < state)
 143                 return;
 144
 145         if (cx->type >= type)
 146                 pr->power.timer_broadcast_on_state = state;
 147 }
 148
 149 static void __lapic_timer_propagate_broadcast(void *arg)
 150 {
 151         struct acpi_processor *pr = (struct acpi_processor *) arg;
 152
 153         if (pr->power.timer_broadcast_on_state < INT_MAX)
 154                 tick_broadcast_enable();
 155         else
 156                 tick_broadcast_disable();
 157 }
 158
 159 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 160 {
 161         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 162                                  (void *)pr, 1);
 163 }
 164
 165 /* Power(C) State timer broadcast control */
 166 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 167                                         struct acpi_processor_cx *cx)
 168 {
 169         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 170 }
 171
 172 #else
 173
 174 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 175                                    struct acpi_processor_cx *cstate) { }
 176 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 177
 178 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 179                                         struct acpi_processor_cx *cx)
 180 {
 181         return false;
 182 }
 183
 184 #endif
 185
 186 #if defined(CONFIG_X86)
 187 static void tsc_check_state(int state)
 188 {
 189         switch (boot_cpu_data.x86_vendor) {
 190         case X86_VENDOR_HYGON:
 191         case X86_VENDOR_AMD:
 192         case X86_VENDOR_INTEL:
 193         case X86_VENDOR_CENTAUR:
 194         case X86_VENDOR_ZHAOXIN:
 195                 /*
 196                  * AMD Fam10h TSC will tick in all
 197                  * C/P/S0/S1 states when this bit is set.
 198                  */
 199                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 200                         return;
 201                 fallthrough;
 202         default:
 203                 /* TSC could halt in idle, so notify users */
 204                 if (state > ACPI_STATE_C1)
 205                         mark_tsc_unstable("TSC halts in idle");
 206         }
 207 }
 208 #else
 209 static void tsc_check_state(int state) { return; }
 210 #endif
 211
 212 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 213 {
 214
 215         if (!pr->pblk)
 216                 return -ENODEV;
 217
 218         /* if info is obtained from pblk/fadt, type equals state */
 219         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 220         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 221
 222 #ifndef CONFIG_HOTPLUG_CPU
 223         /*
 224          * Check for P_LVL2_UP flag before entering C2 and above on
 225          * an SMP system.
 226          */
 227         if ((num_online_cpus() > 1) &&
 228             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 229                 return -ENODEV;
 230 #endif
 231
 232         /* determine C2 and C3 address from pblk */
 233         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 234         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 235
 236         /* determine latencies from FADT */
 237         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 238         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 239
 240         /*
 241          * FADT specified C2 latency must be less than or equal to
 242          * 100 microseconds.
 243          */
 244         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 245                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 246                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 247                 /* invalidate C2 */
 248                 pr->power.states[ACPI_STATE_C2].address = 0;
 249         }
 250
 251         /*
 252          * FADT supplied C3 latency must be less than or equal to
 253          * 1000 microseconds.
 254          */
 255         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 257                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 258                 /* invalidate C3 */
 259                 pr->power.states[ACPI_STATE_C3].address = 0;
 260         }
 261
 262         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 264                           pr->power.states[ACPI_STATE_C2].address,
 265                           pr->power.states[ACPI_STATE_C3].address));
 266
 267         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 268                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 269                          pr->power.states[ACPI_STATE_C2].address);
 270         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 271                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 272                          pr->power.states[ACPI_STATE_C3].address);
 273
 274         return 0;
 275 }
 276
 277 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 278 {
 279         if (!pr->power.states[ACPI_STATE_C1].valid) {
 280                 /* set the first C-State to C1 */
 281                 /* all processors need to support C1 */
 282                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 283                 pr->power.states[ACPI_STATE_C1].valid = 1;
 284                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 285
 286                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 287                          ACPI_CX_DESC_LEN, "ACPI HLT");
 288         }
 289         /* the C0 state only exists as a filler in our array */
 290         pr->power.states[ACPI_STATE_C0].valid = 1;
 291         return 0;
 292 }
 293
 294 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 295 {
 296         int ret;
 297
 298         if (nocst)
 299                 return -ENODEV;
 300
 301         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 302         if (ret)
 303                 return ret;
 304
 305         if (!pr->power.count)
 306                 return -EFAULT;
 307
 308         pr->flags.has_cst = 1;
 309         return 0;
 310 }
 311
 312 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 313                                            struct acpi_processor_cx *cx)
 314 {
 315         static int bm_check_flag = -1;
 316         static int bm_control_flag = -1;
 317
 318
 319         if (!cx->address)
 320                 return;
 321
 322         /*
 323          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 324          * DMA transfers are used by any ISA device to avoid livelock.
 325          * Note that we could disable Type-F DMA (as recommended by
 326          * the erratum), but this is known to disrupt certain ISA
 327          * devices thus we take the conservative approach.
 328          */
 329         else if (errata.piix4.fdma) {
 330                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 331                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 332                 return;
 333         }
 334
 335         /* All the logic here assumes flags.bm_check is same across all CPUs */
 336         if (bm_check_flag == -1) {
 337                 /* Determine whether bm_check is needed based on CPU  */
 338                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 339                 bm_check_flag = pr->flags.bm_check;
 340                 bm_control_flag = pr->flags.bm_control;
 341         } else {
 342                 pr->flags.bm_check = bm_check_flag;
 343                 pr->flags.bm_control = bm_control_flag;
 344         }
 345
 346         if (pr->flags.bm_check) {
 347                 if (!pr->flags.bm_control) {
 348                         if (pr->flags.has_cst != 1) {
 349                                 /* bus mastering control is necessary */
 350                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 351                                         "C3 support requires BM control\n"));
 352                                 return;
 353                         } else {
 354                                 /* Here we enter C3 without bus mastering */
 355                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 356                                         "C3 support without BM control\n"));
 357                         }
 358                 }
 359         } else {
 360                 /*
 361                  * WBINVD should be set in fadt, for C3 state to be
 362                  * supported on when bm_check is not required.
 363                  */
 364                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 365                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 366                                           "Cache invalidation should work properly"
 367                                           " for C3 to be enabled on SMP systems\n"));
 368                         return;
 369                 }
 370         }
 371
 372         /*
 373          * Otherwise we've met all of our C3 requirements.
 374          * Normalize the C3 latency to expidite policy.  Enable
 375          * checking of bus mastering status (bm_check) so we can
 376          * use this in our C3 policy
 377          */
 378         cx->valid = 1;
 379
 380         /*
 381          * On older chipsets, BM_RLD needs to be set
 382          * in order for Bus Master activity to wake the
 383          * system from C3.  Newer chipsets handle DMA
 384          * during C3 automatically and BM_RLD is a NOP.
 385          * In either case, the proper way to
 386          * handle BM_RLD is to set it and leave it set.
 387          */
 388         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 389
 390         return;
 391 }
 392
 393 static int acpi_cst_latency_cmp(const void *a, const void *b)
 394 {
 395         const struct acpi_processor_cx *x = a, *y = b;
 396
 397         if (!(x->valid && y->valid))
 398                 return 0;
 399         if (x->latency > y->latency)
 400                 return 1;
 401         if (x->latency < y->latency)
 402                 return -1;
 403         return 0;
 404 }
 405 static void acpi_cst_latency_swap(void *a, void *b, int n)
 406 {
 407         struct acpi_processor_cx *x = a, *y = b;
 408         u32 tmp;
 409
 410         if (!(x->valid && y->valid))
 411                 return;
 412         tmp = x->latency;
 413         x->latency = y->latency;
 414         y->latency = tmp;
 415 }
 416
 417 static int acpi_processor_power_verify(struct acpi_processor *pr)
 418 {
 419         unsigned int i;
 420         unsigned int working = 0;
 421         unsigned int last_latency = 0;
 422         unsigned int last_type = 0;
 423         bool buggy_latency = false;
 424
 425         pr->power.timer_broadcast_on_state = INT_MAX;
 426
 427         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 428                 struct acpi_processor_cx *cx = &pr->power.states[i];
 429
 430                 switch (cx->type) {
 431                 case ACPI_STATE_C1:
 432                         cx->valid = 1;
 433                         break;
 434
 435                 case ACPI_STATE_C2:
 436                         if (!cx->address)
 437                                 break;
 438                         cx->valid = 1;
 439                         break;
 440
 441                 case ACPI_STATE_C3:
 442                         acpi_processor_power_verify_c3(pr, cx);
 443                         break;
 444                 }
 445                 if (!cx->valid)
 446                         continue;
 447                 if (cx->type >= last_type && cx->latency < last_latency)
 448                         buggy_latency = true;
 449                 last_latency = cx->latency;
 450                 last_type = cx->type;
 451
 452                 lapic_timer_check_state(i, pr, cx);
 453                 tsc_check_state(cx->type);
 454                 working++;
 455         }
 456
 457         if (buggy_latency) {
 458                 pr_notice("FW issue: working around C-state latencies out of order\n");
 459                 sort(&pr->power.states[1], max_cstate,
 460                      sizeof(struct acpi_processor_cx),
 461                      acpi_cst_latency_cmp,
 462                      acpi_cst_latency_swap);
 463         }
 464
 465         lapic_timer_propagate_broadcast(pr);
 466
 467         return (working);
 468 }
 469
 470 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 471 {
 472         unsigned int i;
 473         int result;
 474
 475
 476         /* NOTE: the idle thread may not be running while calling
 477          * this function */
 478
 479         /* Zero initialize all the C-states info. */
 480         memset(pr->power.states, 0, sizeof(pr->power.states));
 481
 482         result = acpi_processor_get_power_info_cst(pr);
 483         if (result == -ENODEV)
 484                 result = acpi_processor_get_power_info_fadt(pr);
 485
 486         if (result)
 487                 return result;
 488
 489         acpi_processor_get_power_info_default(pr);
 490
 491         pr->power.count = acpi_processor_power_verify(pr);
 492
 493         /*
 494          * if one state of type C2 or C3 is available, mark this
 495          * CPU as being "idle manageable"
 496          */
 497         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 498                 if (pr->power.states[i].valid) {
 499                         pr->power.count = i;
 500                         pr->flags.power = 1;
 501                 }
 502         }
 503
 504         return 0;
 505 }
 506
 507 /**
 508  * acpi_idle_bm_check - checks if bus master activity was detected
 509  */
 510 static int acpi_idle_bm_check(void)
 511 {
 512         u32 bm_status = 0;
 513
 514         if (bm_check_disable)
 515                 return 0;
 516
 517         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 518         if (bm_status)
 519                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 520         /*
 521          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 522          * the true state of bus mastering activity; forcing us to
 523          * manually check the BMIDEA bit of each IDE channel.
 524          */
 525         else if (errata.piix4.bmisx) {
 526                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 527                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 528                         bm_status = 1;
 529         }
 530         return bm_status;
 531 }
 532
 533 static void wait_for_freeze(void)
 534 {
 535 #ifdef  CONFIG_X86
 536         /* No delay is needed if we are in guest */
 537         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 538                 return;
 539 #endif
 540         /* Dummy wait op - must do something useless after P_LVL2 read
 541            because chipsets cannot guarantee that STPCLK# signal
 542            gets asserted in time to freeze execution properly. */
 543         inl(acpi_gbl_FADT.xpm_timer_block.address);
 544 }
 545
 546 /**
 547  * acpi_idle_do_entry - enter idle state using the appropriate method
 548  * @cx: cstate data
 549  *
 550  * Caller disables interrupt before call and enables interrupt after return.
 551  */
 552 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 553 {
 554         if (cx->entry_method == ACPI_CSTATE_FFH) {
 555                 /* Call into architectural FFH based C-state */
 556                 acpi_processor_ffh_cstate_enter(cx);
 557         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 558                 acpi_safe_halt();
 559         } else {
 560                 /* IO port based C-state */
 561                 inb(cx->address);
 562                 wait_for_freeze();
 563         }
 564 }
 565
 566 /**
 567  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 568  * @dev: the target CPU
 569  * @index: the index of suggested state
 570  */
 571 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 572 {
 573         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 574
 575         ACPI_FLUSH_CPU_CACHE();
 576
 577         while (1) {
 578
 579                 if (cx->entry_method == ACPI_CSTATE_HALT)
 580                         safe_halt();
 581                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 582                         inb(cx->address);
 583                         wait_for_freeze();
 584                 } else
 585                         return -ENODEV;
 586
 587 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
 588                 cond_wakeup_cpu0();
 589 #endif
 590         }
 591
 592         /* Never reached */
 593         return 0;
 594 }
 595
 596 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 597 {
 598         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 599                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 600 }
 601
 602 static int c3_cpu_count;
 603 static DEFINE_RAW_SPINLOCK(c3_lock);
 604
 605 /**
 606  * acpi_idle_enter_bm - enters C3 with proper BM handling
 607  * @drv: cpuidle driver
 608  * @pr: Target processor
 609  * @cx: Target state context
 610  * @index: index of target state
 611  */
 612 static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv,
 613                                struct acpi_processor *pr,
 614                                struct acpi_processor_cx *cx,
 615                                int index)
 616 {
 617         static struct acpi_processor_cx safe_cx = {
 618                 .entry_method = ACPI_CSTATE_HALT,
 619         };
 620
 621         /*
 622          * disable bus master
 623          * bm_check implies we need ARB_DIS
 624          * bm_control implies whether we can do ARB_DIS
 625          *
 626          * That leaves a case where bm_check is set and bm_control is not set.
 627          * In that case we cannot do much, we enter C3 without doing anything.
 628          */
 629         bool dis_bm = pr->flags.bm_control;
 630
 631         /* If we can skip BM, demote to a safe state. */
 632         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 633                 dis_bm = false;
 634                 index = drv->safe_state_index;
 635                 if (index >= 0) {
 636                         cx = this_cpu_read(acpi_cstate[index]);
 637                 } else {
 638                         cx = &safe_cx;
 639                         index = -EBUSY;
 640                 }
 641         }
 642
 643         if (dis_bm) {
 644                 raw_spin_lock(&c3_lock);
 645                 c3_cpu_count++;
 646                 /* Disable bus master arbitration when all CPUs are in C3 */
 647                 if (c3_cpu_count == num_online_cpus())
 648                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 649                 raw_spin_unlock(&c3_lock);
 650         }
 651
 652         rcu_idle_enter();
 653
 654         acpi_idle_do_entry(cx);
 655
 656         rcu_idle_exit();
 657
 658         /* Re-enable bus master arbitration */
 659         if (dis_bm) {
 660                 raw_spin_lock(&c3_lock);
 661                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 662                 c3_cpu_count--;
 663                 raw_spin_unlock(&c3_lock);
 664         }
 665
 666         return index;
 667 }
 668
 669 static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev,
 670                            struct cpuidle_driver *drv, int index)
 671 {
 672         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 673         struct acpi_processor *pr;
 674
 675         pr = __this_cpu_read(processors);
 676         if (unlikely(!pr))
 677                 return -EINVAL;
 678
 679         if (cx->type != ACPI_STATE_C1) {
 680                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 681                         return acpi_idle_enter_bm(drv, pr, cx, index);
 682
 683                 /* C2 to C1 demotion. */
 684                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 685                         index = ACPI_IDLE_STATE_START;
 686                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 687                 }
 688         }
 689
 690         if (cx->type == ACPI_STATE_C3)
 691                 ACPI_FLUSH_CPU_CACHE();
 692
 693         acpi_idle_do_entry(cx);
 694
 695         return index;
 696 }
 697
 698 static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 699                                   struct cpuidle_driver *drv, int index)
 700 {
 701         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 702
 703         if (cx->type == ACPI_STATE_C3) {
 704                 struct acpi_processor *pr = __this_cpu_read(processors);
 705
 706                 if (unlikely(!pr))
 707                         return 0;
 708
 709                 if (pr->flags.bm_check) {
 710                         u8 bm_sts_skip = cx->bm_sts_skip;
 711
 712                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 713                         cx->bm_sts_skip = 1;
 714                         acpi_idle_enter_bm(drv, pr, cx, index);
 715                         cx->bm_sts_skip = bm_sts_skip;
 716
 717                         return 0;
 718                 } else {
 719                         ACPI_FLUSH_CPU_CACHE();
 720                 }
 721         }
 722         acpi_idle_do_entry(cx);
 723
 724         return 0;
 725 }
 726
 727 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 728                                            struct cpuidle_device *dev)
 729 {
 730         int i, count = ACPI_IDLE_STATE_START;
 731         struct acpi_processor_cx *cx;
 732         struct cpuidle_state *state;
 733
 734         if (max_cstate == 0)
 735                 max_cstate = 1;
 736
 737         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 738                 state = &acpi_idle_driver.states[count];
 739                 cx = &pr->power.states[i];
 740
 741                 if (!cx->valid)
 742                         continue;
 743
 744                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 745
 746                 if (lapic_timer_needs_broadcast(pr, cx))
 747                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 748
 749                 if (cx->type == ACPI_STATE_C3) {
 750                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 751                         if (pr->flags.bm_check)
 752                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 753                 }
 754
 755                 count++;
 756                 if (count == CPUIDLE_STATE_MAX)
 757                         break;
 758         }
 759
 760         if (!count)
 761                 return -EINVAL;
 762
 763         return 0;
 764 }
 765
 766 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 767 {
 768         int i, count;
 769         struct acpi_processor_cx *cx;
 770         struct cpuidle_state *state;
 771         struct cpuidle_driver *drv = &acpi_idle_driver;
 772
 773         if (max_cstate == 0)
 774                 max_cstate = 1;
 775
 776         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 777                 cpuidle_poll_state_init(drv);
 778                 count = 1;
 779         } else {
 780                 count = 0;
 781         }
 782
 783         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 784                 cx = &pr->power.states[i];
 785
 786                 if (!cx->valid)
 787                         continue;
 788
 789                 state = &drv->states[count];
 790                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 791                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 792                 state->exit_latency = cx->latency;
 793                 state->target_residency = cx->latency * latency_factor;
 794                 state->enter = acpi_idle_enter;
 795
 796                 state->flags = 0;
 797                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 798                         state->enter_dead = acpi_idle_play_dead;
 799                         drv->safe_state_index = count;
 800                 }
 801                 /*
 802                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 803                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 804                  * particularly interesting from the suspend-to-idle angle, so
 805                  * avoid C1 and the situations in which we may need to fall back
 806                  * to it altogether.
 807                  */
 808                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 809                         state->enter_s2idle = acpi_idle_enter_s2idle;
 810
 811                 count++;
 812                 if (count == CPUIDLE_STATE_MAX)
 813                         break;
 814         }
 815
 816         drv->state_count = count;
 817
 818         if (!count)
 819                 return -EINVAL;
 820
 821         return 0;
 822 }
 823
 824 static inline void acpi_processor_cstate_first_run_checks(void)
 825 {
 826         static int first_run;
 827
 828         if (first_run)
 829                 return;
 830         dmi_check_system(processor_power_dmi_table);
 831         max_cstate = acpi_processor_cstate_check(max_cstate);
 832         if (max_cstate < ACPI_C_STATES_MAX)
 833                 pr_notice("ACPI: processor limited to max C-state %d\n",
 834                           max_cstate);
 835         first_run++;
 836
 837         if (nocst)
 838                 return;
 839
 840         acpi_processor_claim_cst_control();
 841 }
 842 #else
 843
 844 static inline int disabled_by_idle_boot_param(void) { return 0; }
 845 static inline void acpi_processor_cstate_first_run_checks(void) { }
 846 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 847 {
 848         return -ENODEV;
 849 }
 850
 851 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 852                                            struct cpuidle_device *dev)
 853 {
 854         return -EINVAL;
 855 }
 856
 857 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 858 {
 859         return -EINVAL;
 860 }
 861
 862 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 863
 864 struct acpi_lpi_states_array {
 865         unsigned int size;
 866         unsigned int composite_states_size;
 867         struct acpi_lpi_state *entries;
 868         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 869 };
 870
 871 static int obj_get_integer(union acpi_object *obj, u32 *value)
 872 {
 873         if (obj->type != ACPI_TYPE_INTEGER)
 874                 return -EINVAL;
 875
 876         *value = obj->integer.value;
 877         return 0;
 878 }
 879
 880 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 881                                        struct acpi_lpi_states_array *info)
 882 {
 883         acpi_status status;
 884         int ret = 0;
 885         int pkg_count, state_idx = 1, loop;
 886         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 887         union acpi_object *lpi_data;
 888         struct acpi_lpi_state *lpi_state;
 889
 890         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 891         if (ACPI_FAILURE(status)) {
 892                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 893                 return -ENODEV;
 894         }
 895
 896         lpi_data = buffer.pointer;
 897
 898         /* There must be at least 4 elements = 3 elements + 1 package */
 899         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 900             lpi_data->package.count < 4) {
 901                 pr_debug("not enough elements in _LPI\n");
 902                 ret = -ENODATA;
 903                 goto end;
 904         }
 905
 906         pkg_count = lpi_data->package.elements[2].integer.value;
 907
 908         /* Validate number of power states. */
 909         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 910                 pr_debug("count given by _LPI is not valid\n");
 911                 ret = -ENODATA;
 912                 goto end;
 913         }
 914
 915         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 916         if (!lpi_state) {
 917                 ret = -ENOMEM;
 918                 goto end;
 919         }
 920
 921         info->size = pkg_count;
 922         info->entries = lpi_state;
 923
 924         /* LPI States start at index 3 */
 925         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 926                 union acpi_object *element, *pkg_elem, *obj;
 927
 928                 element = &lpi_data->package.elements[loop];
 929                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 930                         continue;
 931
 932                 pkg_elem = element->package.elements;
 933
 934                 obj = pkg_elem + 6;
 935                 if (obj->type == ACPI_TYPE_BUFFER) {
 936                         struct acpi_power_register *reg;
 937
 938                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 939                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 940                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 941                                 continue;
 942
 943                         lpi_state->address = reg->address;
 944                         lpi_state->entry_method =
 945                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 946                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 947                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 948                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 949                         lpi_state->address = obj->integer.value;
 950                 } else {
 951                         continue;
 952                 }
 953
 954                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 955
 956                 obj = pkg_elem + 9;
 957                 if (obj->type == ACPI_TYPE_STRING)
 958                         strlcpy(lpi_state->desc, obj->string.pointer,
 959                                 ACPI_CX_DESC_LEN);
 960
 961                 lpi_state->index = state_idx;
 962                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 963                         pr_debug("No min. residency found, assuming 10 us\n");
 964                         lpi_state->min_residency = 10;
 965                 }
 966
 967                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 968                         pr_debug("No wakeup residency found, assuming 10 us\n");
 969                         lpi_state->wake_latency = 10;
 970                 }
 971
 972                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 973                         lpi_state->flags = 0;
 974
 975                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 976                         lpi_state->arch_flags = 0;
 977
 978                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 979                         lpi_state->res_cnt_freq = 1;
 980
 981                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 982                         lpi_state->enable_parent_state = 0;
 983         }
 984
 985         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 986 end:
 987         kfree(buffer.pointer);
 988         return ret;
 989 }
 990
 991 /*
 992  * flat_state_cnt - the number of composite LPI states after the process of flattening
 993  */
 994 static int flat_state_cnt;
 995
 996 /**
 997  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 998  *
 999  * @local: local LPI state
1000  * @parent: parent LPI state
1001  * @result: composite LPI state
1002  */
1003 static bool combine_lpi_states(struct acpi_lpi_state *local,
1004                                struct acpi_lpi_state *parent,
1005                                struct acpi_lpi_state *result)
1006 {
1007         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1008                 if (!parent->address) /* 0 means autopromotable */
1009                         return false;
1010                 result->address = local->address + parent->address;
1011         } else {
1012                 result->address = parent->address;
1013         }
1014
1015         result->min_residency = max(local->min_residency, parent->min_residency);
1016         result->wake_latency = local->wake_latency + parent->wake_latency;
1017         result->enable_parent_state = parent->enable_parent_state;
1018         result->entry_method = local->entry_method;
1019
1020         result->flags = parent->flags;
1021         result->arch_flags = parent->arch_flags;
1022         result->index = parent->index;
1023
1024         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1025         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1026         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1027         return true;
1028 }
1029
1030 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1031
1032 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1033                                   struct acpi_lpi_state *t)
1034 {
1035         curr_level->composite_states[curr_level->composite_states_size++] = t;
1036 }
1037
1038 static int flatten_lpi_states(struct acpi_processor *pr,
1039                               struct acpi_lpi_states_array *curr_level,
1040                               struct acpi_lpi_states_array *prev_level)
1041 {
1042         int i, j, state_count = curr_level->size;
1043         struct acpi_lpi_state *p, *t = curr_level->entries;
1044
1045         curr_level->composite_states_size = 0;
1046         for (j = 0; j < state_count; j++, t++) {
1047                 struct acpi_lpi_state *flpi;
1048
1049                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1050                         continue;
1051
1052                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1053                         pr_warn("Limiting number of LPI states to max (%d)\n",
1054                                 ACPI_PROCESSOR_MAX_POWER);
1055                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1056                         break;
1057                 }
1058
1059                 flpi = &pr->power.lpi_states[flat_state_cnt];
1060
1061                 if (!prev_level) { /* leaf/processor node */
1062                         memcpy(flpi, t, sizeof(*t));
1063                         stash_composite_state(curr_level, flpi);
1064                         flat_state_cnt++;
1065                         continue;
1066                 }
1067
1068                 for (i = 0; i < prev_level->composite_states_size; i++) {
1069                         p = prev_level->composite_states[i];
1070                         if (t->index <= p->enable_parent_state &&
1071                             combine_lpi_states(p, t, flpi)) {
1072                                 stash_composite_state(curr_level, flpi);
1073                                 flat_state_cnt++;
1074                                 flpi++;
1075                         }
1076                 }
1077         }
1078
1079         kfree(curr_level->entries);
1080         return 0;
1081 }
1082
1083 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1084 {
1085         return -EOPNOTSUPP;
1086 }
1087
1088 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1089 {
1090         int ret, i;
1091         acpi_status status;
1092         acpi_handle handle = pr->handle, pr_ahandle;
1093         struct acpi_device *d = NULL;
1094         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1095
1096         /* make sure our architecture has support */
1097         ret = acpi_processor_ffh_lpi_probe(pr->id);
1098         if (ret == -EOPNOTSUPP)
1099                 return ret;
1100
1101         if (!osc_pc_lpi_support_confirmed)
1102                 return -EOPNOTSUPP;
1103
1104         if (!acpi_has_method(handle, "_LPI"))
1105                 return -EINVAL;
1106
1107         flat_state_cnt = 0;
1108         prev = &info[0];
1109         curr = &info[1];
1110         handle = pr->handle;
1111         ret = acpi_processor_evaluate_lpi(handle, prev);
1112         if (ret)
1113                 return ret;
1114         flatten_lpi_states(pr, prev, NULL);
1115
1116         status = acpi_get_parent(handle, &pr_ahandle);
1117         while (ACPI_SUCCESS(status)) {
1118                 acpi_bus_get_device(pr_ahandle, &d);
1119                 handle = pr_ahandle;
1120
1121                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1122                         break;
1123
1124                 /* can be optional ? */
1125                 if (!acpi_has_method(handle, "_LPI"))
1126                         break;
1127
1128                 ret = acpi_processor_evaluate_lpi(handle, curr);
1129                 if (ret)
1130                         break;
1131
1132                 /* flatten all the LPI states in this level of hierarchy */
1133                 flatten_lpi_states(pr, curr, prev);
1134
1135                 tmp = prev, prev = curr, curr = tmp;
1136
1137                 status = acpi_get_parent(handle, &pr_ahandle);
1138         }
1139
1140         pr->power.count = flat_state_cnt;
1141         /* reset the index after flattening */
1142         for (i = 0; i < pr->power.count; i++)
1143                 pr->power.lpi_states[i].index = i;
1144
1145         /* Tell driver that _LPI is supported. */
1146         pr->flags.has_lpi = 1;
1147         pr->flags.power = 1;
1148
1149         return 0;
1150 }
1151
1152 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1153 {
1154         return -ENODEV;
1155 }
1156
1157 /**
1158  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1159  * @dev: the target CPU
1160  * @drv: cpuidle driver containing cpuidle state info
1161  * @index: index of target state
1162  *
1163  * Return: 0 for success or negative value for error
1164  */
1165 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1166                                struct cpuidle_driver *drv, int index)
1167 {
1168         struct acpi_processor *pr;
1169         struct acpi_lpi_state *lpi;
1170
1171         pr = __this_cpu_read(processors);
1172
1173         if (unlikely(!pr))
1174                 return -EINVAL;
1175
1176         lpi = &pr->power.lpi_states[index];
1177         if (lpi->entry_method == ACPI_CSTATE_FFH)
1178                 return acpi_processor_ffh_lpi_enter(lpi);
1179
1180         return -EINVAL;
1181 }
1182
1183 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1184 {
1185         int i;
1186         struct acpi_lpi_state *lpi;
1187         struct cpuidle_state *state;
1188         struct cpuidle_driver *drv = &acpi_idle_driver;
1189
1190         if (!pr->flags.has_lpi)
1191                 return -EOPNOTSUPP;
1192
1193         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1194                 lpi = &pr->power.lpi_states[i];
1195
1196                 state = &drv->states[i];
1197                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1198                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1199                 state->exit_latency = lpi->wake_latency;
1200                 state->target_residency = lpi->min_residency;
1201                 if (lpi->arch_flags)
1202                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1203                 state->enter = acpi_idle_lpi_enter;
1204                 drv->safe_state_index = i;
1205         }
1206
1207         drv->state_count = i;
1208
1209         return 0;
1210 }
1211
1212 /**
1213  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1214  * global state data i.e. idle routines
1215  *
1216  * @pr: the ACPI processor
1217  */
1218 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1219 {
1220         int i;
1221         struct cpuidle_driver *drv = &acpi_idle_driver;
1222
1223         if (!pr->flags.power_setup_done || !pr->flags.power)
1224                 return -EINVAL;
1225
1226         drv->safe_state_index = -1;
1227         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1228                 drv->states[i].name[0] = '\0';
1229                 drv->states[i].desc[0] = '\0';
1230         }
1231
1232         if (pr->flags.has_lpi)
1233                 return acpi_processor_setup_lpi_states(pr);
1234
1235         return acpi_processor_setup_cstates(pr);
1236 }
1237
1238 /**
1239  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1240  * device i.e. per-cpu data
1241  *
1242  * @pr: the ACPI processor
1243  * @dev : the cpuidle device
1244  */
1245 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1246                                             struct cpuidle_device *dev)
1247 {
1248         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1249                 return -EINVAL;
1250
1251         dev->cpu = pr->id;
1252         if (pr->flags.has_lpi)
1253                 return acpi_processor_ffh_lpi_probe(pr->id);
1254
1255         return acpi_processor_setup_cpuidle_cx(pr, dev);
1256 }
1257
1258 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1259 {
1260         int ret;
1261
1262         ret = acpi_processor_get_lpi_info(pr);
1263         if (ret)
1264                 ret = acpi_processor_get_cstate_info(pr);
1265
1266         return ret;
1267 }
1268
1269 int acpi_processor_hotplug(struct acpi_processor *pr)
1270 {
1271         int ret = 0;
1272         struct cpuidle_device *dev;
1273
1274         if (disabled_by_idle_boot_param())
1275                 return 0;
1276
1277         if (!pr->flags.power_setup_done)
1278                 return -ENODEV;
1279
1280         dev = per_cpu(acpi_cpuidle_device, pr->id);
1281         cpuidle_pause_and_lock();
1282         cpuidle_disable_device(dev);
1283         ret = acpi_processor_get_power_info(pr);
1284         if (!ret && pr->flags.power) {
1285                 acpi_processor_setup_cpuidle_dev(pr, dev);
1286                 ret = cpuidle_enable_device(dev);
1287         }
1288         cpuidle_resume_and_unlock();
1289
1290         return ret;
1291 }
1292
1293 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1294 {
1295         int cpu;
1296         struct acpi_processor *_pr;
1297         struct cpuidle_device *dev;
1298
1299         if (disabled_by_idle_boot_param())
1300                 return 0;
1301
1302         if (!pr->flags.power_setup_done)
1303                 return -ENODEV;
1304
1305         /*
1306          * FIXME:  Design the ACPI notification to make it once per
1307          * system instead of once per-cpu.  This condition is a hack
1308          * to make the code that updates C-States be called once.
1309          */
1310
1311         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1312
1313                 /* Protect against cpu-hotplug */
1314                 get_online_cpus();
1315                 cpuidle_pause_and_lock();
1316
1317                 /* Disable all cpuidle devices */
1318                 for_each_online_cpu(cpu) {
1319                         _pr = per_cpu(processors, cpu);
1320                         if (!_pr || !_pr->flags.power_setup_done)
1321                                 continue;
1322                         dev = per_cpu(acpi_cpuidle_device, cpu);
1323                         cpuidle_disable_device(dev);
1324                 }
1325
1326                 /* Populate Updated C-state information */
1327                 acpi_processor_get_power_info(pr);
1328                 acpi_processor_setup_cpuidle_states(pr);
1329
1330                 /* Enable all cpuidle devices */
1331                 for_each_online_cpu(cpu) {
1332                         _pr = per_cpu(processors, cpu);
1333                         if (!_pr || !_pr->flags.power_setup_done)
1334                                 continue;
1335                         acpi_processor_get_power_info(_pr);
1336                         if (_pr->flags.power) {
1337                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1338                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1339                                 cpuidle_enable_device(dev);
1340                         }
1341                 }
1342                 cpuidle_resume_and_unlock();
1343                 put_online_cpus();
1344         }
1345
1346         return 0;
1347 }
1348
1349 static int acpi_processor_registered;
1350
1351 int acpi_processor_power_init(struct acpi_processor *pr)
1352 {
1353         int retval;
1354         struct cpuidle_device *dev;
1355
1356         if (disabled_by_idle_boot_param())
1357                 return 0;
1358
1359         acpi_processor_cstate_first_run_checks();
1360
1361         if (!acpi_processor_get_power_info(pr))
1362                 pr->flags.power_setup_done = 1;
1363
1364         /*
1365          * Install the idle handler if processor power management is supported.
1366          * Note that we use previously set idle handler will be used on
1367          * platforms that only support C1.
1368          */
1369         if (pr->flags.power) {
1370                 /* Register acpi_idle_driver if not already registered */
1371                 if (!acpi_processor_registered) {
1372                         acpi_processor_setup_cpuidle_states(pr);
1373                         retval = cpuidle_register_driver(&acpi_idle_driver);
1374                         if (retval)
1375                                 return retval;
1376                         pr_debug("%s registered with cpuidle\n",
1377                                  acpi_idle_driver.name);
1378                 }
1379
1380                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1381                 if (!dev)
1382                         return -ENOMEM;
1383                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1384
1385                 acpi_processor_setup_cpuidle_dev(pr, dev);
1386
1387                 /* Register per-cpu cpuidle_device. Cpuidle driver
1388                  * must already be registered before registering device
1389                  */
1390                 retval = cpuidle_register_device(dev);
1391                 if (retval) {
1392                         if (acpi_processor_registered == 0)
1393                                 cpuidle_unregister_driver(&acpi_idle_driver);
1394                         return retval;
1395                 }
1396                 acpi_processor_registered++;
1397         }
1398         return 0;
1399 }
1400
1401 int acpi_processor_power_exit(struct acpi_processor *pr)
1402 {
1403         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1404
1405         if (disabled_by_idle_boot_param())
1406                 return 0;
1407
1408         if (pr->flags.power) {
1409                 cpuidle_unregister_device(dev);
1410                 acpi_processor_registered--;
1411                 if (acpi_processor_registered == 0)
1412                         cpuidle_unregister_driver(&acpi_idle_driver);
1413         }
1414
1415         pr->flags.power_setup_done = 0;
1416         return 0;
1417 }