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 <acpi/processor.h>
  25
  26 /*
  27  * Include the apic definitions for x86 to have the APIC timer related defines
  28  * available also for UP (on SMP it gets magically included via linux/smp.h).
  29  * asm/acpi.h is not an option, as it would require more include magic. Also
  30  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  31  */
  32 #ifdef CONFIG_X86
  33 #include <asm/apic.h>
  34 #include <asm/cpu.h>
  35 #endif
  36
  37 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  38
  39 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  40 module_param(max_cstate, uint, 0000);
  41 static unsigned int nocst __read_mostly;
  42 module_param(nocst, uint, 0000);
  43 static int bm_check_disable __read_mostly;
  44 module_param(bm_check_disable, uint, 0000);
  45
  46 static unsigned int latency_factor __read_mostly = 2;
  47 module_param(latency_factor, uint, 0644);
  48
  49 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  50
  51 struct cpuidle_driver acpi_idle_driver = {
  52         .name =         "acpi_idle",
  53         .owner =        THIS_MODULE,
  54 };
  55
  56 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  57 static
  58 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  59
  60 static int disabled_by_idle_boot_param(void)
  61 {
  62         return boot_option_idle_override == IDLE_POLL ||
  63                 boot_option_idle_override == IDLE_HALT;
  64 }
  65
  66 /*
  67  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  68  * For now disable this. Probably a bug somewhere else.
  69  *
  70  * To skip this limit, boot/load with a large max_cstate limit.
  71  */
  72 static int set_max_cstate(const struct dmi_system_id *id)
  73 {
  74         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  75                 return 0;
  76
  77         pr_notice("%s detected - limiting to C%ld max_cstate."
  78                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  79                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  80
  81         max_cstate = (long)id->driver_data;
  82
  83         return 0;
  84 }
  85
  86 static const struct dmi_system_id processor_power_dmi_table[] = {
  87         { set_max_cstate, "Clevo 5600D", {
  88           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  89           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  90          (void *)2},
  91         { set_max_cstate, "Pavilion zv5000", {
  92           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  93           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  94          (void *)1},
  95         { set_max_cstate, "Asus L8400B", {
  96           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  97           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
  98          (void *)1},
  99         /* T40 can not handle C3 idle state */
 100         { set_max_cstate, "IBM ThinkPad T40", {
 101           DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
 102           DMI_MATCH(DMI_PRODUCT_NAME, "23737CU")},
 103          (void *)2},
 104         {},
 105 };
 106
 107
 108 /*
 109  * Callers should disable interrupts before the call and enable
 110  * interrupts after return.
 111  */
 112 static void __cpuidle acpi_safe_halt(void)
 113 {
 114         if (!tif_need_resched()) {
 115                 safe_halt();
 116                 local_irq_disable();
 117         }
 118 }
 119
 120 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 121
 122 /*
 123  * Some BIOS implementations switch to C3 in the published C2 state.
 124  * This seems to be a common problem on AMD boxen, but other vendors
 125  * are affected too. We pick the most conservative approach: we assume
 126  * that the local APIC stops in both C2 and C3.
 127  */
 128 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 129                                    struct acpi_processor_cx *cx)
 130 {
 131         struct acpi_processor_power *pwr = &pr->power;
 132         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 133
 134         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 135                 return;
 136
 137         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 138                 type = ACPI_STATE_C1;
 139
 140         /*
 141          * Check, if one of the previous states already marked the lapic
 142          * unstable
 143          */
 144         if (pwr->timer_broadcast_on_state < state)
 145                 return;
 146
 147         if (cx->type >= type)
 148                 pr->power.timer_broadcast_on_state = state;
 149 }
 150
 151 static void __lapic_timer_propagate_broadcast(void *arg)
 152 {
 153         struct acpi_processor *pr = (struct acpi_processor *) arg;
 154
 155         if (pr->power.timer_broadcast_on_state < INT_MAX)
 156                 tick_broadcast_enable();
 157         else
 158                 tick_broadcast_disable();
 159 }
 160
 161 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 162 {
 163         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 164                                  (void *)pr, 1);
 165 }
 166
 167 /* Power(C) State timer broadcast control */
 168 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 169                                         struct acpi_processor_cx *cx)
 170 {
 171         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 172 }
 173
 174 #else
 175
 176 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 177                                    struct acpi_processor_cx *cstate) { }
 178 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 179
 180 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 181                                         struct acpi_processor_cx *cx)
 182 {
 183         return false;
 184 }
 185
 186 #endif
 187
 188 #if defined(CONFIG_X86)
 189 static void tsc_check_state(int state)
 190 {
 191         switch (boot_cpu_data.x86_vendor) {
 192         case X86_VENDOR_HYGON:
 193         case X86_VENDOR_AMD:
 194         case X86_VENDOR_INTEL:
 195         case X86_VENDOR_CENTAUR:
 196         case X86_VENDOR_ZHAOXIN:
 197                 /*
 198                  * AMD Fam10h TSC will tick in all
 199                  * C/P/S0/S1 states when this bit is set.
 200                  */
 201                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 202                         return;
 203                 fallthrough;
 204         default:
 205                 /* TSC could halt in idle, so notify users */
 206                 if (state > ACPI_STATE_C1)
 207                         mark_tsc_unstable("TSC halts in idle");
 208         }
 209 }
 210 #else
 211 static void tsc_check_state(int state) { return; }
 212 #endif
 213
 214 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 215 {
 216
 217         if (!pr->pblk)
 218                 return -ENODEV;
 219
 220         /* if info is obtained from pblk/fadt, type equals state */
 221         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 222         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 223
 224 #ifndef CONFIG_HOTPLUG_CPU
 225         /*
 226          * Check for P_LVL2_UP flag before entering C2 and above on
 227          * an SMP system.
 228          */
 229         if ((num_online_cpus() > 1) &&
 230             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 231                 return -ENODEV;
 232 #endif
 233
 234         /* determine C2 and C3 address from pblk */
 235         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 236         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 237
 238         /* determine latencies from FADT */
 239         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 240         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 241
 242         /*
 243          * FADT specified C2 latency must be less than or equal to
 244          * 100 microseconds.
 245          */
 246         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 247                 acpi_handle_debug(pr->handle, "C2 latency too large [%d]\n",
 248                                   acpi_gbl_FADT.c2_latency);
 249                 /* invalidate C2 */
 250                 pr->power.states[ACPI_STATE_C2].address = 0;
 251         }
 252
 253         /*
 254          * FADT supplied C3 latency must be less than or equal to
 255          * 1000 microseconds.
 256          */
 257         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 258                 acpi_handle_debug(pr->handle, "C3 latency too large [%d]\n",
 259                                   acpi_gbl_FADT.c3_latency);
 260                 /* invalidate C3 */
 261                 pr->power.states[ACPI_STATE_C3].address = 0;
 262         }
 263
 264         acpi_handle_debug(pr->handle, "lvl2[0x%08x] lvl3[0x%08x]\n",
 265                           pr->power.states[ACPI_STATE_C2].address,
 266                           pr->power.states[ACPI_STATE_C3].address);
 267
 268         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 269                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 270                          pr->power.states[ACPI_STATE_C2].address);
 271         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 272                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 273                          pr->power.states[ACPI_STATE_C3].address);
 274
 275         return 0;
 276 }
 277
 278 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 279 {
 280         if (!pr->power.states[ACPI_STATE_C1].valid) {
 281                 /* set the first C-State to C1 */
 282                 /* all processors need to support C1 */
 283                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 284                 pr->power.states[ACPI_STATE_C1].valid = 1;
 285                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 286
 287                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 288                          ACPI_CX_DESC_LEN, "ACPI HLT");
 289         }
 290         /* the C0 state only exists as a filler in our array */
 291         pr->power.states[ACPI_STATE_C0].valid = 1;
 292         return 0;
 293 }
 294
 295 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 296 {
 297         int ret;
 298
 299         if (nocst)
 300                 return -ENODEV;
 301
 302         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 303         if (ret)
 304                 return ret;
 305
 306         if (!pr->power.count)
 307                 return -EFAULT;
 308
 309         pr->flags.has_cst = 1;
 310         return 0;
 311 }
 312
 313 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 314                                            struct acpi_processor_cx *cx)
 315 {
 316         static int bm_check_flag = -1;
 317         static int bm_control_flag = -1;
 318
 319
 320         if (!cx->address)
 321                 return;
 322
 323         /*
 324          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 325          * DMA transfers are used by any ISA device to avoid livelock.
 326          * Note that we could disable Type-F DMA (as recommended by
 327          * the erratum), but this is known to disrupt certain ISA
 328          * devices thus we take the conservative approach.
 329          */
 330         else if (errata.piix4.fdma) {
 331                 acpi_handle_debug(pr->handle,
 332                                   "C3 not supported on PIIX4 with Type-F DMA\n");
 333                 return;
 334         }
 335
 336         /* All the logic here assumes flags.bm_check is same across all CPUs */
 337         if (bm_check_flag == -1) {
 338                 /* Determine whether bm_check is needed based on CPU  */
 339                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 340                 bm_check_flag = pr->flags.bm_check;
 341                 bm_control_flag = pr->flags.bm_control;
 342         } else {
 343                 pr->flags.bm_check = bm_check_flag;
 344                 pr->flags.bm_control = bm_control_flag;
 345         }
 346
 347         if (pr->flags.bm_check) {
 348                 if (!pr->flags.bm_control) {
 349                         if (pr->flags.has_cst != 1) {
 350                                 /* bus mastering control is necessary */
 351                                 acpi_handle_debug(pr->handle,
 352                                                   "C3 support requires BM control\n");
 353                                 return;
 354                         } else {
 355                                 /* Here we enter C3 without bus mastering */
 356                                 acpi_handle_debug(pr->handle,
 357                                                   "C3 support without BM control\n");
 358                         }
 359                 }
 360         } else {
 361                 /*
 362                  * WBINVD should be set in fadt, for C3 state to be
 363                  * supported on when bm_check is not required.
 364                  */
 365                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 366                         acpi_handle_debug(pr->handle,
 367                                           "Cache invalidation should work properly"
 368                                           " for C3 to be enabled on SMP systems\n");
 369                         return;
 370                 }
 371         }
 372
 373         /*
 374          * Otherwise we've met all of our C3 requirements.
 375          * Normalize the C3 latency to expidite policy.  Enable
 376          * checking of bus mastering status (bm_check) so we can
 377          * use this in our C3 policy
 378          */
 379         cx->valid = 1;
 380
 381         /*
 382          * On older chipsets, BM_RLD needs to be set
 383          * in order for Bus Master activity to wake the
 384          * system from C3.  Newer chipsets handle DMA
 385          * during C3 automatically and BM_RLD is a NOP.
 386          * In either case, the proper way to
 387          * handle BM_RLD is to set it and leave it set.
 388          */
 389         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 390
 391         return;
 392 }
 393
 394 static int acpi_cst_latency_cmp(const void *a, const void *b)
 395 {
 396         const struct acpi_processor_cx *x = a, *y = b;
 397
 398         if (!(x->valid && y->valid))
 399                 return 0;
 400         if (x->latency > y->latency)
 401                 return 1;
 402         if (x->latency < y->latency)
 403                 return -1;
 404         return 0;
 405 }
 406 static void acpi_cst_latency_swap(void *a, void *b, int n)
 407 {
 408         struct acpi_processor_cx *x = a, *y = b;
 409
 410         if (!(x->valid && y->valid))
 411                 return;
 412         swap(x->latency, y->latency);
 413 }
 414
 415 static int acpi_processor_power_verify(struct acpi_processor *pr)
 416 {
 417         unsigned int i;
 418         unsigned int working = 0;
 419         unsigned int last_latency = 0;
 420         unsigned int last_type = 0;
 421         bool buggy_latency = false;
 422
 423         pr->power.timer_broadcast_on_state = INT_MAX;
 424
 425         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 426                 struct acpi_processor_cx *cx = &pr->power.states[i];
 427
 428                 switch (cx->type) {
 429                 case ACPI_STATE_C1:
 430                         cx->valid = 1;
 431                         break;
 432
 433                 case ACPI_STATE_C2:
 434                         if (!cx->address)
 435                                 break;
 436                         cx->valid = 1;
 437                         break;
 438
 439                 case ACPI_STATE_C3:
 440                         acpi_processor_power_verify_c3(pr, cx);
 441                         break;
 442                 }
 443                 if (!cx->valid)
 444                         continue;
 445                 if (cx->type >= last_type && cx->latency < last_latency)
 446                         buggy_latency = true;
 447                 last_latency = cx->latency;
 448                 last_type = cx->type;
 449
 450                 lapic_timer_check_state(i, pr, cx);
 451                 tsc_check_state(cx->type);
 452                 working++;
 453         }
 454
 455         if (buggy_latency) {
 456                 pr_notice("FW issue: working around C-state latencies out of order\n");
 457                 sort(&pr->power.states[1], max_cstate,
 458                      sizeof(struct acpi_processor_cx),
 459                      acpi_cst_latency_cmp,
 460                      acpi_cst_latency_swap);
 461         }
 462
 463         lapic_timer_propagate_broadcast(pr);
 464
 465         return (working);
 466 }
 467
 468 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 469 {
 470         unsigned int i;
 471         int result;
 472
 473
 474         /* NOTE: the idle thread may not be running while calling
 475          * this function */
 476
 477         /* Zero initialize all the C-states info. */
 478         memset(pr->power.states, 0, sizeof(pr->power.states));
 479
 480         result = acpi_processor_get_power_info_cst(pr);
 481         if (result == -ENODEV)
 482                 result = acpi_processor_get_power_info_fadt(pr);
 483
 484         if (result)
 485                 return result;
 486
 487         acpi_processor_get_power_info_default(pr);
 488
 489         pr->power.count = acpi_processor_power_verify(pr);
 490
 491         /*
 492          * if one state of type C2 or C3 is available, mark this
 493          * CPU as being "idle manageable"
 494          */
 495         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 496                 if (pr->power.states[i].valid) {
 497                         pr->power.count = i;
 498                         pr->flags.power = 1;
 499                 }
 500         }
 501
 502         return 0;
 503 }
 504
 505 /**
 506  * acpi_idle_bm_check - checks if bus master activity was detected
 507  */
 508 static int acpi_idle_bm_check(void)
 509 {
 510         u32 bm_status = 0;
 511
 512         if (bm_check_disable)
 513                 return 0;
 514
 515         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 516         if (bm_status)
 517                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 518         /*
 519          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 520          * the true state of bus mastering activity; forcing us to
 521          * manually check the BMIDEA bit of each IDE channel.
 522          */
 523         else if (errata.piix4.bmisx) {
 524                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 525                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 526                         bm_status = 1;
 527         }
 528         return bm_status;
 529 }
 530
 531 static void wait_for_freeze(void)
 532 {
 533 #ifdef  CONFIG_X86
 534         /* No delay is needed if we are in guest */
 535         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 536                 return;
 537 #endif
 538         /* Dummy wait op - must do something useless after P_LVL2 read
 539            because chipsets cannot guarantee that STPCLK# signal
 540            gets asserted in time to freeze execution properly. */
 541         inl(acpi_gbl_FADT.xpm_timer_block.address);
 542 }
 543
 544 /**
 545  * acpi_idle_do_entry - enter idle state using the appropriate method
 546  * @cx: cstate data
 547  *
 548  * Caller disables interrupt before call and enables interrupt after return.
 549  */
 550 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 551 {
 552         if (cx->entry_method == ACPI_CSTATE_FFH) {
 553                 /* Call into architectural FFH based C-state */
 554                 acpi_processor_ffh_cstate_enter(cx);
 555         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 556                 acpi_safe_halt();
 557         } else {
 558                 /* IO port based C-state */
 559                 inb(cx->address);
 560                 wait_for_freeze();
 561         }
 562 }
 563
 564 /**
 565  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 566  * @dev: the target CPU
 567  * @index: the index of suggested state
 568  */
 569 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 570 {
 571         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 572
 573         ACPI_FLUSH_CPU_CACHE();
 574
 575         while (1) {
 576
 577                 if (cx->entry_method == ACPI_CSTATE_HALT)
 578                         safe_halt();
 579                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 580                         inb(cx->address);
 581                         wait_for_freeze();
 582                 } else
 583                         return -ENODEV;
 584
 585 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
 586                 cond_wakeup_cpu0();
 587 #endif
 588         }
 589
 590         /* Never reached */
 591         return 0;
 592 }
 593
 594 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 595 {
 596         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 597                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 598 }
 599
 600 static int c3_cpu_count;
 601 static DEFINE_RAW_SPINLOCK(c3_lock);
 602
 603 /**
 604  * acpi_idle_enter_bm - enters C3 with proper BM handling
 605  * @drv: cpuidle driver
 606  * @pr: Target processor
 607  * @cx: Target state context
 608  * @index: index of target state
 609  */
 610 static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
 611                                struct acpi_processor *pr,
 612                                struct acpi_processor_cx *cx,
 613                                int index)
 614 {
 615         static struct acpi_processor_cx safe_cx = {
 616                 .entry_method = ACPI_CSTATE_HALT,
 617         };
 618
 619         /*
 620          * disable bus master
 621          * bm_check implies we need ARB_DIS
 622          * bm_control implies whether we can do ARB_DIS
 623          *
 624          * That leaves a case where bm_check is set and bm_control is not set.
 625          * In that case we cannot do much, we enter C3 without doing anything.
 626          */
 627         bool dis_bm = pr->flags.bm_control;
 628
 629         /* If we can skip BM, demote to a safe state. */
 630         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 631                 dis_bm = false;
 632                 index = drv->safe_state_index;
 633                 if (index >= 0) {
 634                         cx = this_cpu_read(acpi_cstate[index]);
 635                 } else {
 636                         cx = &safe_cx;
 637                         index = -EBUSY;
 638                 }
 639         }
 640
 641         if (dis_bm) {
 642                 raw_spin_lock(&c3_lock);
 643                 c3_cpu_count++;
 644                 /* Disable bus master arbitration when all CPUs are in C3 */
 645                 if (c3_cpu_count == num_online_cpus())
 646                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 647                 raw_spin_unlock(&c3_lock);
 648         }
 649
 650         rcu_idle_enter();
 651
 652         acpi_idle_do_entry(cx);
 653
 654         rcu_idle_exit();
 655
 656         /* Re-enable bus master arbitration */
 657         if (dis_bm) {
 658                 raw_spin_lock(&c3_lock);
 659                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 660                 c3_cpu_count--;
 661                 raw_spin_unlock(&c3_lock);
 662         }
 663
 664         return index;
 665 }
 666
 667 static int acpi_idle_enter(struct cpuidle_device *dev,
 668                            struct cpuidle_driver *drv, int index)
 669 {
 670         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 671         struct acpi_processor *pr;
 672
 673         pr = __this_cpu_read(processors);
 674         if (unlikely(!pr))
 675                 return -EINVAL;
 676
 677         if (cx->type != ACPI_STATE_C1) {
 678                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 679                         return acpi_idle_enter_bm(drv, pr, cx, index);
 680
 681                 /* C2 to C1 demotion. */
 682                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 683                         index = ACPI_IDLE_STATE_START;
 684                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 685                 }
 686         }
 687
 688         if (cx->type == ACPI_STATE_C3)
 689                 ACPI_FLUSH_CPU_CACHE();
 690
 691         acpi_idle_do_entry(cx);
 692
 693         return index;
 694 }
 695
 696 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 697                                   struct cpuidle_driver *drv, int index)
 698 {
 699         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 700
 701         if (cx->type == ACPI_STATE_C3) {
 702                 struct acpi_processor *pr = __this_cpu_read(processors);
 703
 704                 if (unlikely(!pr))
 705                         return 0;
 706
 707                 if (pr->flags.bm_check) {
 708                         u8 bm_sts_skip = cx->bm_sts_skip;
 709
 710                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 711                         cx->bm_sts_skip = 1;
 712                         acpi_idle_enter_bm(drv, pr, cx, index);
 713                         cx->bm_sts_skip = bm_sts_skip;
 714
 715                         return 0;
 716                 } else {
 717                         ACPI_FLUSH_CPU_CACHE();
 718                 }
 719         }
 720         acpi_idle_do_entry(cx);
 721
 722         return 0;
 723 }
 724
 725 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 726                                            struct cpuidle_device *dev)
 727 {
 728         int i, count = ACPI_IDLE_STATE_START;
 729         struct acpi_processor_cx *cx;
 730         struct cpuidle_state *state;
 731
 732         if (max_cstate == 0)
 733                 max_cstate = 1;
 734
 735         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 736                 state = &acpi_idle_driver.states[count];
 737                 cx = &pr->power.states[i];
 738
 739                 if (!cx->valid)
 740                         continue;
 741
 742                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 743
 744                 if (lapic_timer_needs_broadcast(pr, cx))
 745                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 746
 747                 if (cx->type == ACPI_STATE_C3) {
 748                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 749                         if (pr->flags.bm_check)
 750                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 751                 }
 752
 753                 count++;
 754                 if (count == CPUIDLE_STATE_MAX)
 755                         break;
 756         }
 757
 758         if (!count)
 759                 return -EINVAL;
 760
 761         return 0;
 762 }
 763
 764 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 765 {
 766         int i, count;
 767         struct acpi_processor_cx *cx;
 768         struct cpuidle_state *state;
 769         struct cpuidle_driver *drv = &acpi_idle_driver;
 770
 771         if (max_cstate == 0)
 772                 max_cstate = 1;
 773
 774         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 775                 cpuidle_poll_state_init(drv);
 776                 count = 1;
 777         } else {
 778                 count = 0;
 779         }
 780
 781         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 782                 cx = &pr->power.states[i];
 783
 784                 if (!cx->valid)
 785                         continue;
 786
 787                 state = &drv->states[count];
 788                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 789                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 790                 state->exit_latency = cx->latency;
 791                 state->target_residency = cx->latency * latency_factor;
 792                 state->enter = acpi_idle_enter;
 793
 794                 state->flags = 0;
 795                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 ||
 796                     cx->type == ACPI_STATE_C3) {
 797                         state->enter_dead = acpi_idle_play_dead;
 798                         drv->safe_state_index = count;
 799                 }
 800                 /*
 801                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 802                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 803                  * particularly interesting from the suspend-to-idle angle, so
 804                  * avoid C1 and the situations in which we may need to fall back
 805                  * to it altogether.
 806                  */
 807                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 808                         state->enter_s2idle = acpi_idle_enter_s2idle;
 809
 810                 count++;
 811                 if (count == CPUIDLE_STATE_MAX)
 812                         break;
 813         }
 814
 815         drv->state_count = count;
 816
 817         if (!count)
 818                 return -EINVAL;
 819
 820         return 0;
 821 }
 822
 823 static inline void acpi_processor_cstate_first_run_checks(void)
 824 {
 825         static int first_run;
 826
 827         if (first_run)
 828                 return;
 829         dmi_check_system(processor_power_dmi_table);
 830         max_cstate = acpi_processor_cstate_check(max_cstate);
 831         if (max_cstate < ACPI_C_STATES_MAX)
 832                 pr_notice("processor limited to max C-state %d\n", max_cstate);
 833
 834         first_run++;
 835
 836         if (nocst)
 837                 return;
 838
 839         acpi_processor_claim_cst_control();
 840 }
 841 #else
 842
 843 static inline int disabled_by_idle_boot_param(void) { return 0; }
 844 static inline void acpi_processor_cstate_first_run_checks(void) { }
 845 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 846 {
 847         return -ENODEV;
 848 }
 849
 850 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 851                                            struct cpuidle_device *dev)
 852 {
 853         return -EINVAL;
 854 }
 855
 856 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 857 {
 858         return -EINVAL;
 859 }
 860
 861 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 862
 863 struct acpi_lpi_states_array {
 864         unsigned int size;
 865         unsigned int composite_states_size;
 866         struct acpi_lpi_state *entries;
 867         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 868 };
 869
 870 static int obj_get_integer(union acpi_object *obj, u32 *value)
 871 {
 872         if (obj->type != ACPI_TYPE_INTEGER)
 873                 return -EINVAL;
 874
 875         *value = obj->integer.value;
 876         return 0;
 877 }
 878
 879 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 880                                        struct acpi_lpi_states_array *info)
 881 {
 882         acpi_status status;
 883         int ret = 0;
 884         int pkg_count, state_idx = 1, loop;
 885         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 886         union acpi_object *lpi_data;
 887         struct acpi_lpi_state *lpi_state;
 888
 889         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 890         if (ACPI_FAILURE(status)) {
 891                 acpi_handle_debug(handle, "No _LPI, giving up\n");
 892                 return -ENODEV;
 893         }
 894
 895         lpi_data = buffer.pointer;
 896
 897         /* There must be at least 4 elements = 3 elements + 1 package */
 898         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 899             lpi_data->package.count < 4) {
 900                 pr_debug("not enough elements in _LPI\n");
 901                 ret = -ENODATA;
 902                 goto end;
 903         }
 904
 905         pkg_count = lpi_data->package.elements[2].integer.value;
 906
 907         /* Validate number of power states. */
 908         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 909                 pr_debug("count given by _LPI is not valid\n");
 910                 ret = -ENODATA;
 911                 goto end;
 912         }
 913
 914         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 915         if (!lpi_state) {
 916                 ret = -ENOMEM;
 917                 goto end;
 918         }
 919
 920         info->size = pkg_count;
 921         info->entries = lpi_state;
 922
 923         /* LPI States start at index 3 */
 924         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 925                 union acpi_object *element, *pkg_elem, *obj;
 926
 927                 element = &lpi_data->package.elements[loop];
 928                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 929                         continue;
 930
 931                 pkg_elem = element->package.elements;
 932
 933                 obj = pkg_elem + 6;
 934                 if (obj->type == ACPI_TYPE_BUFFER) {
 935                         struct acpi_power_register *reg;
 936
 937                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 938                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 939                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 940                                 continue;
 941
 942                         lpi_state->address = reg->address;
 943                         lpi_state->entry_method =
 944                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 945                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 946                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 947                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 948                         lpi_state->address = obj->integer.value;
 949                 } else {
 950                         continue;
 951                 }
 952
 953                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 954
 955                 obj = pkg_elem + 9;
 956                 if (obj->type == ACPI_TYPE_STRING)
 957                         strlcpy(lpi_state->desc, obj->string.pointer,
 958                                 ACPI_CX_DESC_LEN);
 959
 960                 lpi_state->index = state_idx;
 961                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 962                         pr_debug("No min. residency found, assuming 10 us\n");
 963                         lpi_state->min_residency = 10;
 964                 }
 965
 966                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 967                         pr_debug("No wakeup residency found, assuming 10 us\n");
 968                         lpi_state->wake_latency = 10;
 969                 }
 970
 971                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 972                         lpi_state->flags = 0;
 973
 974                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 975                         lpi_state->arch_flags = 0;
 976
 977                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 978                         lpi_state->res_cnt_freq = 1;
 979
 980                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 981                         lpi_state->enable_parent_state = 0;
 982         }
 983
 984         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 985 end:
 986         kfree(buffer.pointer);
 987         return ret;
 988 }
 989
 990 /*
 991  * flat_state_cnt - the number of composite LPI states after the process of flattening
 992  */
 993 static int flat_state_cnt;
 994
 995 /**
 996  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 997  *
 998  * @local: local LPI state
 999  * @parent: parent LPI state
1000  * @result: composite LPI state
1001  */
1002 static bool combine_lpi_states(struct acpi_lpi_state *local,
1003                                struct acpi_lpi_state *parent,
1004                                struct acpi_lpi_state *result)
1005 {
1006         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1007                 if (!parent->address) /* 0 means autopromotable */
1008                         return false;
1009                 result->address = local->address + parent->address;
1010         } else {
1011                 result->address = parent->address;
1012         }
1013
1014         result->min_residency = max(local->min_residency, parent->min_residency);
1015         result->wake_latency = local->wake_latency + parent->wake_latency;
1016         result->enable_parent_state = parent->enable_parent_state;
1017         result->entry_method = local->entry_method;
1018
1019         result->flags = parent->flags;
1020         result->arch_flags = parent->arch_flags;
1021         result->index = parent->index;
1022
1023         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1024         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1025         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1026         return true;
1027 }
1028
1029 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1030
1031 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1032                                   struct acpi_lpi_state *t)
1033 {
1034         curr_level->composite_states[curr_level->composite_states_size++] = t;
1035 }
1036
1037 static int flatten_lpi_states(struct acpi_processor *pr,
1038                               struct acpi_lpi_states_array *curr_level,
1039                               struct acpi_lpi_states_array *prev_level)
1040 {
1041         int i, j, state_count = curr_level->size;
1042         struct acpi_lpi_state *p, *t = curr_level->entries;
1043
1044         curr_level->composite_states_size = 0;
1045         for (j = 0; j < state_count; j++, t++) {
1046                 struct acpi_lpi_state *flpi;
1047
1048                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1049                         continue;
1050
1051                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1052                         pr_warn("Limiting number of LPI states to max (%d)\n",
1053                                 ACPI_PROCESSOR_MAX_POWER);
1054                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1055                         break;
1056                 }
1057
1058                 flpi = &pr->power.lpi_states[flat_state_cnt];
1059
1060                 if (!prev_level) { /* leaf/processor node */
1061                         memcpy(flpi, t, sizeof(*t));
1062                         stash_composite_state(curr_level, flpi);
1063                         flat_state_cnt++;
1064                         continue;
1065                 }
1066
1067                 for (i = 0; i < prev_level->composite_states_size; i++) {
1068                         p = prev_level->composite_states[i];
1069                         if (t->index <= p->enable_parent_state &&
1070                             combine_lpi_states(p, t, flpi)) {
1071                                 stash_composite_state(curr_level, flpi);
1072                                 flat_state_cnt++;
1073                                 flpi++;
1074                         }
1075                 }
1076         }
1077
1078         kfree(curr_level->entries);
1079         return 0;
1080 }
1081
1082 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1083 {
1084         return -EOPNOTSUPP;
1085 }
1086
1087 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1088 {
1089         int ret, i;
1090         acpi_status status;
1091         acpi_handle handle = pr->handle, pr_ahandle;
1092         struct acpi_device *d = NULL;
1093         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1094
1095         /* make sure our architecture has support */
1096         ret = acpi_processor_ffh_lpi_probe(pr->id);
1097         if (ret == -EOPNOTSUPP)
1098                 return ret;
1099
1100         if (!osc_pc_lpi_support_confirmed)
1101                 return -EOPNOTSUPP;
1102
1103         if (!acpi_has_method(handle, "_LPI"))
1104                 return -EINVAL;
1105
1106         flat_state_cnt = 0;
1107         prev = &info[0];
1108         curr = &info[1];
1109         handle = pr->handle;
1110         ret = acpi_processor_evaluate_lpi(handle, prev);
1111         if (ret)
1112                 return ret;
1113         flatten_lpi_states(pr, prev, NULL);
1114
1115         status = acpi_get_parent(handle, &pr_ahandle);
1116         while (ACPI_SUCCESS(status)) {
1117                 d = acpi_fetch_acpi_dev(pr_ahandle);
1118                 handle = pr_ahandle;
1119
1120                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1121                         break;
1122
1123                 /* can be optional ? */
1124                 if (!acpi_has_method(handle, "_LPI"))
1125                         break;
1126
1127                 ret = acpi_processor_evaluate_lpi(handle, curr);
1128                 if (ret)
1129                         break;
1130
1131                 /* flatten all the LPI states in this level of hierarchy */
1132                 flatten_lpi_states(pr, curr, prev);
1133
1134                 tmp = prev, prev = curr, curr = tmp;
1135
1136                 status = acpi_get_parent(handle, &pr_ahandle);
1137         }
1138
1139         pr->power.count = flat_state_cnt;
1140         /* reset the index after flattening */
1141         for (i = 0; i < pr->power.count; i++)
1142                 pr->power.lpi_states[i].index = i;
1143
1144         /* Tell driver that _LPI is supported. */
1145         pr->flags.has_lpi = 1;
1146         pr->flags.power = 1;
1147
1148         return 0;
1149 }
1150
1151 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1152 {
1153         return -ENODEV;
1154 }
1155
1156 /**
1157  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1158  * @dev: the target CPU
1159  * @drv: cpuidle driver containing cpuidle state info
1160  * @index: index of target state
1161  *
1162  * Return: 0 for success or negative value for error
1163  */
1164 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1165                                struct cpuidle_driver *drv, int index)
1166 {
1167         struct acpi_processor *pr;
1168         struct acpi_lpi_state *lpi;
1169
1170         pr = __this_cpu_read(processors);
1171
1172         if (unlikely(!pr))
1173                 return -EINVAL;
1174
1175         lpi = &pr->power.lpi_states[index];
1176         if (lpi->entry_method == ACPI_CSTATE_FFH)
1177                 return acpi_processor_ffh_lpi_enter(lpi);
1178
1179         return -EINVAL;
1180 }
1181
1182 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1183 {
1184         int i;
1185         struct acpi_lpi_state *lpi;
1186         struct cpuidle_state *state;
1187         struct cpuidle_driver *drv = &acpi_idle_driver;
1188
1189         if (!pr->flags.has_lpi)
1190                 return -EOPNOTSUPP;
1191
1192         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1193                 lpi = &pr->power.lpi_states[i];
1194
1195                 state = &drv->states[i];
1196                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1197                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1198                 state->exit_latency = lpi->wake_latency;
1199                 state->target_residency = lpi->min_residency;
1200                 if (lpi->arch_flags)
1201                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1202                 state->enter = acpi_idle_lpi_enter;
1203                 drv->safe_state_index = i;
1204         }
1205
1206         drv->state_count = i;
1207
1208         return 0;
1209 }
1210
1211 /**
1212  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1213  * global state data i.e. idle routines
1214  *
1215  * @pr: the ACPI processor
1216  */
1217 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1218 {
1219         int i;
1220         struct cpuidle_driver *drv = &acpi_idle_driver;
1221
1222         if (!pr->flags.power_setup_done || !pr->flags.power)
1223                 return -EINVAL;
1224
1225         drv->safe_state_index = -1;
1226         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1227                 drv->states[i].name[0] = '\0';
1228                 drv->states[i].desc[0] = '\0';
1229         }
1230
1231         if (pr->flags.has_lpi)
1232                 return acpi_processor_setup_lpi_states(pr);
1233
1234         return acpi_processor_setup_cstates(pr);
1235 }
1236
1237 /**
1238  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1239  * device i.e. per-cpu data
1240  *
1241  * @pr: the ACPI processor
1242  * @dev : the cpuidle device
1243  */
1244 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1245                                             struct cpuidle_device *dev)
1246 {
1247         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1248                 return -EINVAL;
1249
1250         dev->cpu = pr->id;
1251         if (pr->flags.has_lpi)
1252                 return acpi_processor_ffh_lpi_probe(pr->id);
1253
1254         return acpi_processor_setup_cpuidle_cx(pr, dev);
1255 }
1256
1257 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1258 {
1259         int ret;
1260
1261         ret = acpi_processor_get_lpi_info(pr);
1262         if (ret)
1263                 ret = acpi_processor_get_cstate_info(pr);
1264
1265         return ret;
1266 }
1267
1268 int acpi_processor_hotplug(struct acpi_processor *pr)
1269 {
1270         int ret = 0;
1271         struct cpuidle_device *dev;
1272
1273         if (disabled_by_idle_boot_param())
1274                 return 0;
1275
1276         if (!pr->flags.power_setup_done)
1277                 return -ENODEV;
1278
1279         dev = per_cpu(acpi_cpuidle_device, pr->id);
1280         cpuidle_pause_and_lock();
1281         cpuidle_disable_device(dev);
1282         ret = acpi_processor_get_power_info(pr);
1283         if (!ret && pr->flags.power) {
1284                 acpi_processor_setup_cpuidle_dev(pr, dev);
1285                 ret = cpuidle_enable_device(dev);
1286         }
1287         cpuidle_resume_and_unlock();
1288
1289         return ret;
1290 }
1291
1292 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1293 {
1294         int cpu;
1295         struct acpi_processor *_pr;
1296         struct cpuidle_device *dev;
1297
1298         if (disabled_by_idle_boot_param())
1299                 return 0;
1300
1301         if (!pr->flags.power_setup_done)
1302                 return -ENODEV;
1303
1304         /*
1305          * FIXME:  Design the ACPI notification to make it once per
1306          * system instead of once per-cpu.  This condition is a hack
1307          * to make the code that updates C-States be called once.
1308          */
1309
1310         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1311
1312                 /* Protect against cpu-hotplug */
1313                 cpus_read_lock();
1314                 cpuidle_pause_and_lock();
1315
1316                 /* Disable all cpuidle devices */
1317                 for_each_online_cpu(cpu) {
1318                         _pr = per_cpu(processors, cpu);
1319                         if (!_pr || !_pr->flags.power_setup_done)
1320                                 continue;
1321                         dev = per_cpu(acpi_cpuidle_device, cpu);
1322                         cpuidle_disable_device(dev);
1323                 }
1324
1325                 /* Populate Updated C-state information */
1326                 acpi_processor_get_power_info(pr);
1327                 acpi_processor_setup_cpuidle_states(pr);
1328
1329                 /* Enable all cpuidle devices */
1330                 for_each_online_cpu(cpu) {
1331                         _pr = per_cpu(processors, cpu);
1332                         if (!_pr || !_pr->flags.power_setup_done)
1333                                 continue;
1334                         acpi_processor_get_power_info(_pr);
1335                         if (_pr->flags.power) {
1336                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1337                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1338                                 cpuidle_enable_device(dev);
1339                         }
1340                 }
1341                 cpuidle_resume_and_unlock();
1342                 cpus_read_unlock();
1343         }
1344
1345         return 0;
1346 }
1347
1348 static int acpi_processor_registered;
1349
1350 int acpi_processor_power_init(struct acpi_processor *pr)
1351 {
1352         int retval;
1353         struct cpuidle_device *dev;
1354
1355         if (disabled_by_idle_boot_param())
1356                 return 0;
1357
1358         acpi_processor_cstate_first_run_checks();
1359
1360         if (!acpi_processor_get_power_info(pr))
1361                 pr->flags.power_setup_done = 1;
1362
1363         /*
1364          * Install the idle handler if processor power management is supported.
1365          * Note that we use previously set idle handler will be used on
1366          * platforms that only support C1.
1367          */
1368         if (pr->flags.power) {
1369                 /* Register acpi_idle_driver if not already registered */
1370                 if (!acpi_processor_registered) {
1371                         acpi_processor_setup_cpuidle_states(pr);
1372                         retval = cpuidle_register_driver(&acpi_idle_driver);
1373                         if (retval)
1374                                 return retval;
1375                         pr_debug("%s registered with cpuidle\n",
1376                                  acpi_idle_driver.name);
1377                 }
1378
1379                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1380                 if (!dev)
1381                         return -ENOMEM;
1382                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1383
1384                 acpi_processor_setup_cpuidle_dev(pr, dev);
1385
1386                 /* Register per-cpu cpuidle_device. Cpuidle driver
1387                  * must already be registered before registering device
1388                  */
1389                 retval = cpuidle_register_device(dev);
1390                 if (retval) {
1391                         if (acpi_processor_registered == 0)
1392                                 cpuidle_unregister_driver(&acpi_idle_driver);
1393                         return retval;
1394                 }
1395                 acpi_processor_registered++;
1396         }
1397         return 0;
1398 }
1399
1400 int acpi_processor_power_exit(struct acpi_processor *pr)
1401 {
1402         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1403
1404         if (disabled_by_idle_boot_param())
1405                 return 0;
1406
1407         if (pr->flags.power) {
1408                 cpuidle_unregister_device(dev);
1409                 acpi_processor_registered--;
1410                 if (acpi_processor_registered == 0)
1411                         cpuidle_unregister_driver(&acpi_idle_driver);
1412         }
1413
1414         pr->flags.power_setup_done = 0;
1415         return 0;
1416 }