drivers/acpi/processor_idle.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_idle - idle state submodule to the ACPI processor driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  *                      - Added processor hotplug support
  10  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  11  *                      - Added support for C3 on SMP
  12  */
  13 #define pr_fmt(fmt) "ACPI: " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/acpi.h>
  17 #include <linux/dmi.h>
  18 #include <linux/sched.h>       /* need_resched() */
  19 #include <linux/tick.h>
  20 #include <linux/cpuidle.h>
  21 #include <linux/cpu.h>
  22 #include <acpi/processor.h>
  23
  24 /*
  25  * Include the apic definitions for x86 to have the APIC timer related defines
  26  * available also for UP (on SMP it gets magically included via linux/smp.h).
  27  * asm/acpi.h is not an option, as it would require more include magic. Also
  28  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  29  */
  30 #ifdef CONFIG_X86
  31 #include <asm/apic.h>
  32 #endif
  33
  34 #define ACPI_PROCESSOR_CLASS            "processor"
  35 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  36 ACPI_MODULE_NAME("processor_idle");
  37
  38 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  39
  40 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  41 module_param(max_cstate, uint, 0000);
  42 static unsigned int nocst __read_mostly;
  43 module_param(nocst, uint, 0000);
  44 static int bm_check_disable __read_mostly;
  45 module_param(bm_check_disable, uint, 0000);
  46
  47 static unsigned int latency_factor __read_mostly = 2;
  48 module_param(latency_factor, uint, 0644);
  49
  50 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  51
  52 struct cpuidle_driver acpi_idle_driver = {
  53         .name =         "acpi_idle",
  54         .owner =        THIS_MODULE,
  55 };
  56
  57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  58 static
  59 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  60
  61 static int disabled_by_idle_boot_param(void)
  62 {
  63         return boot_option_idle_override == IDLE_POLL ||
  64                 boot_option_idle_override == IDLE_HALT;
  65 }
  66
  67 /*
  68  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  69  * For now disable this. Probably a bug somewhere else.
  70  *
  71  * To skip this limit, boot/load with a large max_cstate limit.
  72  */
  73 static int set_max_cstate(const struct dmi_system_id *id)
  74 {
  75         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  76                 return 0;
  77
  78         pr_notice("%s detected - limiting to C%ld max_cstate."
  79                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  80                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  81
  82         max_cstate = (long)id->driver_data;
  83
  84         return 0;
  85 }
  86
  87 static const struct dmi_system_id processor_power_dmi_table[] = {
  88         { set_max_cstate, "Clevo 5600D", {
  89           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  90           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  91          (void *)2},
  92         { set_max_cstate, "Pavilion zv5000", {
  93           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  94           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  95          (void *)1},
  96         { set_max_cstate, "Asus L8400B", {
  97           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  98           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
  99          (void *)1},
 100         {},
 101 };
 102
 103
 104 /*
 105  * Callers should disable interrupts before the call and enable
 106  * interrupts after return.
 107  */
 108 static void __cpuidle acpi_safe_halt(void)
 109 {
 110         if (!tif_need_resched()) {
 111                 safe_halt();
 112                 local_irq_disable();
 113         }
 114 }
 115
 116 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 117
 118 /*
 119  * Some BIOS implementations switch to C3 in the published C2 state.
 120  * This seems to be a common problem on AMD boxen, but other vendors
 121  * are affected too. We pick the most conservative approach: we assume
 122  * that the local APIC stops in both C2 and C3.
 123  */
 124 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 125                                    struct acpi_processor_cx *cx)
 126 {
 127         struct acpi_processor_power *pwr = &pr->power;
 128         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 129
 130         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 131                 return;
 132
 133         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 134                 type = ACPI_STATE_C1;
 135
 136         /*
 137          * Check, if one of the previous states already marked the lapic
 138          * unstable
 139          */
 140         if (pwr->timer_broadcast_on_state < state)
 141                 return;
 142
 143         if (cx->type >= type)
 144                 pr->power.timer_broadcast_on_state = state;
 145 }
 146
 147 static void __lapic_timer_propagate_broadcast(void *arg)
 148 {
 149         struct acpi_processor *pr = (struct acpi_processor *) arg;
 150
 151         if (pr->power.timer_broadcast_on_state < INT_MAX)
 152                 tick_broadcast_enable();
 153         else
 154                 tick_broadcast_disable();
 155 }
 156
 157 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 158 {
 159         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 160                                  (void *)pr, 1);
 161 }
 162
 163 /* Power(C) State timer broadcast control */
 164 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 165                                         struct acpi_processor_cx *cx)
 166 {
 167         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 168 }
 169
 170 #else
 171
 172 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 173                                    struct acpi_processor_cx *cstate) { }
 174 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 175
 176 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 177                                         struct acpi_processor_cx *cx)
 178 {
 179         return false;
 180 }
 181
 182 #endif
 183
 184 #if defined(CONFIG_X86)
 185 static void tsc_check_state(int state)
 186 {
 187         switch (boot_cpu_data.x86_vendor) {
 188         case X86_VENDOR_HYGON:
 189         case X86_VENDOR_AMD:
 190         case X86_VENDOR_INTEL:
 191         case X86_VENDOR_CENTAUR:
 192         case X86_VENDOR_ZHAOXIN:
 193                 /*
 194                  * AMD Fam10h TSC will tick in all
 195                  * C/P/S0/S1 states when this bit is set.
 196                  */
 197                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 198                         return;
 199                 fallthrough;
 200         default:
 201                 /* TSC could halt in idle, so notify users */
 202                 if (state > ACPI_STATE_C1)
 203                         mark_tsc_unstable("TSC halts in idle");
 204         }
 205 }
 206 #else
 207 static void tsc_check_state(int state) { return; }
 208 #endif
 209
 210 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 211 {
 212
 213         if (!pr->pblk)
 214                 return -ENODEV;
 215
 216         /* if info is obtained from pblk/fadt, type equals state */
 217         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 218         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 219
 220 #ifndef CONFIG_HOTPLUG_CPU
 221         /*
 222          * Check for P_LVL2_UP flag before entering C2 and above on
 223          * an SMP system.
 224          */
 225         if ((num_online_cpus() > 1) &&
 226             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 227                 return -ENODEV;
 228 #endif
 229
 230         /* determine C2 and C3 address from pblk */
 231         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 232         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 233
 234         /* determine latencies from FADT */
 235         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 236         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 237
 238         /*
 239          * FADT specified C2 latency must be less than or equal to
 240          * 100 microseconds.
 241          */
 242         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 243                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 244                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 245                 /* invalidate C2 */
 246                 pr->power.states[ACPI_STATE_C2].address = 0;
 247         }
 248
 249         /*
 250          * FADT supplied C3 latency must be less than or equal to
 251          * 1000 microseconds.
 252          */
 253         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 254                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 255                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 256                 /* invalidate C3 */
 257                 pr->power.states[ACPI_STATE_C3].address = 0;
 258         }
 259
 260         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 261                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 262                           pr->power.states[ACPI_STATE_C2].address,
 263                           pr->power.states[ACPI_STATE_C3].address));
 264
 265         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 266                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 267                          pr->power.states[ACPI_STATE_C2].address);
 268         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 269                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 270                          pr->power.states[ACPI_STATE_C3].address);
 271
 272         return 0;
 273 }
 274
 275 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 276 {
 277         if (!pr->power.states[ACPI_STATE_C1].valid) {
 278                 /* set the first C-State to C1 */
 279                 /* all processors need to support C1 */
 280                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 281                 pr->power.states[ACPI_STATE_C1].valid = 1;
 282                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 283
 284                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 285                          ACPI_CX_DESC_LEN, "ACPI HLT");
 286         }
 287         /* the C0 state only exists as a filler in our array */
 288         pr->power.states[ACPI_STATE_C0].valid = 1;
 289         return 0;
 290 }
 291
 292 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 293 {
 294         int ret;
 295
 296         if (nocst)
 297                 return -ENODEV;
 298
 299         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 300         if (ret)
 301                 return ret;
 302
 303         if (!pr->power.count)
 304                 return -EFAULT;
 305
 306         pr->flags.has_cst = 1;
 307         return 0;
 308 }
 309
 310 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 311                                            struct acpi_processor_cx *cx)
 312 {
 313         static int bm_check_flag = -1;
 314         static int bm_control_flag = -1;
 315
 316
 317         if (!cx->address)
 318                 return;
 319
 320         /*
 321          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 322          * DMA transfers are used by any ISA device to avoid livelock.
 323          * Note that we could disable Type-F DMA (as recommended by
 324          * the erratum), but this is known to disrupt certain ISA
 325          * devices thus we take the conservative approach.
 326          */
 327         else if (errata.piix4.fdma) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 329                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 330                 return;
 331         }
 332
 333         /* All the logic here assumes flags.bm_check is same across all CPUs */
 334         if (bm_check_flag == -1) {
 335                 /* Determine whether bm_check is needed based on CPU  */
 336                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 337                 bm_check_flag = pr->flags.bm_check;
 338                 bm_control_flag = pr->flags.bm_control;
 339         } else {
 340                 pr->flags.bm_check = bm_check_flag;
 341                 pr->flags.bm_control = bm_control_flag;
 342         }
 343
 344         if (pr->flags.bm_check) {
 345                 if (!pr->flags.bm_control) {
 346                         if (pr->flags.has_cst != 1) {
 347                                 /* bus mastering control is necessary */
 348                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                         "C3 support requires BM control\n"));
 350                                 return;
 351                         } else {
 352                                 /* Here we enter C3 without bus mastering */
 353                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 354                                         "C3 support without BM control\n"));
 355                         }
 356                 }
 357         } else {
 358                 /*
 359                  * WBINVD should be set in fadt, for C3 state to be
 360                  * supported on when bm_check is not required.
 361                  */
 362                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 363                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 364                                           "Cache invalidation should work properly"
 365                                           " for C3 to be enabled on SMP systems\n"));
 366                         return;
 367                 }
 368         }
 369
 370         /*
 371          * Otherwise we've met all of our C3 requirements.
 372          * Normalize the C3 latency to expidite policy.  Enable
 373          * checking of bus mastering status (bm_check) so we can
 374          * use this in our C3 policy
 375          */
 376         cx->valid = 1;
 377
 378         /*
 379          * On older chipsets, BM_RLD needs to be set
 380          * in order for Bus Master activity to wake the
 381          * system from C3.  Newer chipsets handle DMA
 382          * during C3 automatically and BM_RLD is a NOP.
 383          * In either case, the proper way to
 384          * handle BM_RLD is to set it and leave it set.
 385          */
 386         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 387
 388         return;
 389 }
 390
 391 static int acpi_processor_power_verify(struct acpi_processor *pr)
 392 {
 393         unsigned int i;
 394         unsigned int working = 0;
 395
 396         pr->power.timer_broadcast_on_state = INT_MAX;
 397
 398         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 399                 struct acpi_processor_cx *cx = &pr->power.states[i];
 400
 401                 switch (cx->type) {
 402                 case ACPI_STATE_C1:
 403                         cx->valid = 1;
 404                         break;
 405
 406                 case ACPI_STATE_C2:
 407                         if (!cx->address)
 408                                 break;
 409                         cx->valid = 1;
 410                         break;
 411
 412                 case ACPI_STATE_C3:
 413                         acpi_processor_power_verify_c3(pr, cx);
 414                         break;
 415                 }
 416                 if (!cx->valid)
 417                         continue;
 418
 419                 lapic_timer_check_state(i, pr, cx);
 420                 tsc_check_state(cx->type);
 421                 working++;
 422         }
 423
 424         lapic_timer_propagate_broadcast(pr);
 425
 426         return (working);
 427 }
 428
 429 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 430 {
 431         unsigned int i;
 432         int result;
 433
 434
 435         /* NOTE: the idle thread may not be running while calling
 436          * this function */
 437
 438         /* Zero initialize all the C-states info. */
 439         memset(pr->power.states, 0, sizeof(pr->power.states));
 440
 441         result = acpi_processor_get_power_info_cst(pr);
 442         if (result == -ENODEV)
 443                 result = acpi_processor_get_power_info_fadt(pr);
 444
 445         if (result)
 446                 return result;
 447
 448         acpi_processor_get_power_info_default(pr);
 449
 450         pr->power.count = acpi_processor_power_verify(pr);
 451
 452         /*
 453          * if one state of type C2 or C3 is available, mark this
 454          * CPU as being "idle manageable"
 455          */
 456         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 457                 if (pr->power.states[i].valid) {
 458                         pr->power.count = i;
 459                         pr->flags.power = 1;
 460                 }
 461         }
 462
 463         return 0;
 464 }
 465
 466 /**
 467  * acpi_idle_bm_check - checks if bus master activity was detected
 468  */
 469 static int acpi_idle_bm_check(void)
 470 {
 471         u32 bm_status = 0;
 472
 473         if (bm_check_disable)
 474                 return 0;
 475
 476         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 477         if (bm_status)
 478                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 479         /*
 480          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 481          * the true state of bus mastering activity; forcing us to
 482          * manually check the BMIDEA bit of each IDE channel.
 483          */
 484         else if (errata.piix4.bmisx) {
 485                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 486                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 487                         bm_status = 1;
 488         }
 489         return bm_status;
 490 }
 491
 492 static void wait_for_freeze(void)
 493 {
 494 #ifdef  CONFIG_X86
 495         /* No delay is needed if we are in guest */
 496         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 497                 return;
 498 #endif
 499         /* Dummy wait op - must do something useless after P_LVL2 read
 500            because chipsets cannot guarantee that STPCLK# signal
 501            gets asserted in time to freeze execution properly. */
 502         inl(acpi_gbl_FADT.xpm_timer_block.address);
 503 }
 504
 505 /**
 506  * acpi_idle_do_entry - enter idle state using the appropriate method
 507  * @cx: cstate data
 508  *
 509  * Caller disables interrupt before call and enables interrupt after return.
 510  */
 511 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 512 {
 513         if (cx->entry_method == ACPI_CSTATE_FFH) {
 514                 /* Call into architectural FFH based C-state */
 515                 acpi_processor_ffh_cstate_enter(cx);
 516         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 517                 acpi_safe_halt();
 518         } else {
 519                 /* IO port based C-state */
 520                 inb(cx->address);
 521                 wait_for_freeze();
 522         }
 523 }
 524
 525 /**
 526  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 527  * @dev: the target CPU
 528  * @index: the index of suggested state
 529  */
 530 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 531 {
 532         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 533
 534         ACPI_FLUSH_CPU_CACHE();
 535
 536         while (1) {
 537
 538                 if (cx->entry_method == ACPI_CSTATE_HALT)
 539                         safe_halt();
 540                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 541                         inb(cx->address);
 542                         wait_for_freeze();
 543                 } else
 544                         return -ENODEV;
 545         }
 546
 547         /* Never reached */
 548         return 0;
 549 }
 550
 551 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 552 {
 553         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 554                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 555 }
 556
 557 static int c3_cpu_count;
 558 static DEFINE_RAW_SPINLOCK(c3_lock);
 559
 560 /**
 561  * acpi_idle_enter_bm - enters C3 with proper BM handling
 562  * @drv: cpuidle driver
 563  * @pr: Target processor
 564  * @cx: Target state context
 565  * @index: index of target state
 566  */
 567 static int acpi_idle_enter_bm(struct cpuidle_driver *drv,
 568                                struct acpi_processor *pr,
 569                                struct acpi_processor_cx *cx,
 570                                int index)
 571 {
 572         static struct acpi_processor_cx safe_cx = {
 573                 .entry_method = ACPI_CSTATE_HALT,
 574         };
 575
 576         /*
 577          * disable bus master
 578          * bm_check implies we need ARB_DIS
 579          * bm_control implies whether we can do ARB_DIS
 580          *
 581          * That leaves a case where bm_check is set and bm_control is not set.
 582          * In that case we cannot do much, we enter C3 without doing anything.
 583          */
 584         bool dis_bm = pr->flags.bm_control;
 585
 586         /* If we can skip BM, demote to a safe state. */
 587         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 588                 dis_bm = false;
 589                 index = drv->safe_state_index;
 590                 if (index >= 0) {
 591                         cx = this_cpu_read(acpi_cstate[index]);
 592                 } else {
 593                         cx = &safe_cx;
 594                         index = -EBUSY;
 595                 }
 596         }
 597
 598         if (dis_bm) {
 599                 raw_spin_lock(&c3_lock);
 600                 c3_cpu_count++;
 601                 /* Disable bus master arbitration when all CPUs are in C3 */
 602                 if (c3_cpu_count == num_online_cpus())
 603                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 604                 raw_spin_unlock(&c3_lock);
 605         }
 606
 607         rcu_idle_enter();
 608
 609         acpi_idle_do_entry(cx);
 610
 611         rcu_idle_exit();
 612
 613         /* Re-enable bus master arbitration */
 614         if (dis_bm) {
 615                 raw_spin_lock(&c3_lock);
 616                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 617                 c3_cpu_count--;
 618                 raw_spin_unlock(&c3_lock);
 619         }
 620
 621         return index;
 622 }
 623
 624 static int acpi_idle_enter(struct cpuidle_device *dev,
 625                            struct cpuidle_driver *drv, int index)
 626 {
 627         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 628         struct acpi_processor *pr;
 629
 630         pr = __this_cpu_read(processors);
 631         if (unlikely(!pr))
 632                 return -EINVAL;
 633
 634         if (cx->type != ACPI_STATE_C1) {
 635                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 636                         return acpi_idle_enter_bm(drv, pr, cx, index);
 637
 638                 /* C2 to C1 demotion. */
 639                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 640                         index = ACPI_IDLE_STATE_START;
 641                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 642                 }
 643         }
 644
 645         if (cx->type == ACPI_STATE_C3)
 646                 ACPI_FLUSH_CPU_CACHE();
 647
 648         acpi_idle_do_entry(cx);
 649
 650         return index;
 651 }
 652
 653 static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 654                                   struct cpuidle_driver *drv, int index)
 655 {
 656         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 657
 658         if (cx->type == ACPI_STATE_C3) {
 659                 struct acpi_processor *pr = __this_cpu_read(processors);
 660
 661                 if (unlikely(!pr))
 662                         return 0;
 663
 664                 if (pr->flags.bm_check) {
 665                         u8 bm_sts_skip = cx->bm_sts_skip;
 666
 667                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 668                         cx->bm_sts_skip = 1;
 669                         acpi_idle_enter_bm(drv, pr, cx, index);
 670                         cx->bm_sts_skip = bm_sts_skip;
 671
 672                         return 0;
 673                 } else {
 674                         ACPI_FLUSH_CPU_CACHE();
 675                 }
 676         }
 677         acpi_idle_do_entry(cx);
 678
 679         return 0;
 680 }
 681
 682 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 683                                            struct cpuidle_device *dev)
 684 {
 685         int i, count = ACPI_IDLE_STATE_START;
 686         struct acpi_processor_cx *cx;
 687         struct cpuidle_state *state;
 688
 689         if (max_cstate == 0)
 690                 max_cstate = 1;
 691
 692         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 693                 state = &acpi_idle_driver.states[count];
 694                 cx = &pr->power.states[i];
 695
 696                 if (!cx->valid)
 697                         continue;
 698
 699                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 700
 701                 if (lapic_timer_needs_broadcast(pr, cx))
 702                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 703
 704                 if (cx->type == ACPI_STATE_C3) {
 705                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 706                         if (pr->flags.bm_check)
 707                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 708                 }
 709
 710                 count++;
 711                 if (count == CPUIDLE_STATE_MAX)
 712                         break;
 713         }
 714
 715         if (!count)
 716                 return -EINVAL;
 717
 718         return 0;
 719 }
 720
 721 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 722 {
 723         int i, count;
 724         struct acpi_processor_cx *cx;
 725         struct cpuidle_state *state;
 726         struct cpuidle_driver *drv = &acpi_idle_driver;
 727
 728         if (max_cstate == 0)
 729                 max_cstate = 1;
 730
 731         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 732                 cpuidle_poll_state_init(drv);
 733                 count = 1;
 734         } else {
 735                 count = 0;
 736         }
 737
 738         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 739                 cx = &pr->power.states[i];
 740
 741                 if (!cx->valid)
 742                         continue;
 743
 744                 state = &drv->states[count];
 745                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 746                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 747                 state->exit_latency = cx->latency;
 748                 state->target_residency = cx->latency * latency_factor;
 749                 state->enter = acpi_idle_enter;
 750
 751                 state->flags = 0;
 752                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 753                         state->enter_dead = acpi_idle_play_dead;
 754                         drv->safe_state_index = count;
 755                 }
 756                 /*
 757                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 758                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 759                  * particularly interesting from the suspend-to-idle angle, so
 760                  * avoid C1 and the situations in which we may need to fall back
 761                  * to it altogether.
 762                  */
 763                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 764                         state->enter_s2idle = acpi_idle_enter_s2idle;
 765
 766                 count++;
 767                 if (count == CPUIDLE_STATE_MAX)
 768                         break;
 769         }
 770
 771         drv->state_count = count;
 772
 773         if (!count)
 774                 return -EINVAL;
 775
 776         return 0;
 777 }
 778
 779 static inline void acpi_processor_cstate_first_run_checks(void)
 780 {
 781         static int first_run;
 782
 783         if (first_run)
 784                 return;
 785         dmi_check_system(processor_power_dmi_table);
 786         max_cstate = acpi_processor_cstate_check(max_cstate);
 787         if (max_cstate < ACPI_C_STATES_MAX)
 788                 pr_notice("ACPI: processor limited to max C-state %d\n",
 789                           max_cstate);
 790         first_run++;
 791
 792         if (nocst)
 793                 return;
 794
 795         acpi_processor_claim_cst_control();
 796 }
 797 #else
 798
 799 static inline int disabled_by_idle_boot_param(void) { return 0; }
 800 static inline void acpi_processor_cstate_first_run_checks(void) { }
 801 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 802 {
 803         return -ENODEV;
 804 }
 805
 806 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 807                                            struct cpuidle_device *dev)
 808 {
 809         return -EINVAL;
 810 }
 811
 812 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 813 {
 814         return -EINVAL;
 815 }
 816
 817 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 818
 819 struct acpi_lpi_states_array {
 820         unsigned int size;
 821         unsigned int composite_states_size;
 822         struct acpi_lpi_state *entries;
 823         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 824 };
 825
 826 static int obj_get_integer(union acpi_object *obj, u32 *value)
 827 {
 828         if (obj->type != ACPI_TYPE_INTEGER)
 829                 return -EINVAL;
 830
 831         *value = obj->integer.value;
 832         return 0;
 833 }
 834
 835 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 836                                        struct acpi_lpi_states_array *info)
 837 {
 838         acpi_status status;
 839         int ret = 0;
 840         int pkg_count, state_idx = 1, loop;
 841         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 842         union acpi_object *lpi_data;
 843         struct acpi_lpi_state *lpi_state;
 844
 845         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 846         if (ACPI_FAILURE(status)) {
 847                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 848                 return -ENODEV;
 849         }
 850
 851         lpi_data = buffer.pointer;
 852
 853         /* There must be at least 4 elements = 3 elements + 1 package */
 854         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 855             lpi_data->package.count < 4) {
 856                 pr_debug("not enough elements in _LPI\n");
 857                 ret = -ENODATA;
 858                 goto end;
 859         }
 860
 861         pkg_count = lpi_data->package.elements[2].integer.value;
 862
 863         /* Validate number of power states. */
 864         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 865                 pr_debug("count given by _LPI is not valid\n");
 866                 ret = -ENODATA;
 867                 goto end;
 868         }
 869
 870         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 871         if (!lpi_state) {
 872                 ret = -ENOMEM;
 873                 goto end;
 874         }
 875
 876         info->size = pkg_count;
 877         info->entries = lpi_state;
 878
 879         /* LPI States start at index 3 */
 880         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 881                 union acpi_object *element, *pkg_elem, *obj;
 882
 883                 element = &lpi_data->package.elements[loop];
 884                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 885                         continue;
 886
 887                 pkg_elem = element->package.elements;
 888
 889                 obj = pkg_elem + 6;
 890                 if (obj->type == ACPI_TYPE_BUFFER) {
 891                         struct acpi_power_register *reg;
 892
 893                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 894                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 895                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 896                                 continue;
 897
 898                         lpi_state->address = reg->address;
 899                         lpi_state->entry_method =
 900                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 901                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 902                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 903                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 904                         lpi_state->address = obj->integer.value;
 905                 } else {
 906                         continue;
 907                 }
 908
 909                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 910
 911                 obj = pkg_elem + 9;
 912                 if (obj->type == ACPI_TYPE_STRING)
 913                         strlcpy(lpi_state->desc, obj->string.pointer,
 914                                 ACPI_CX_DESC_LEN);
 915
 916                 lpi_state->index = state_idx;
 917                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 918                         pr_debug("No min. residency found, assuming 10 us\n");
 919                         lpi_state->min_residency = 10;
 920                 }
 921
 922                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 923                         pr_debug("No wakeup residency found, assuming 10 us\n");
 924                         lpi_state->wake_latency = 10;
 925                 }
 926
 927                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 928                         lpi_state->flags = 0;
 929
 930                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 931                         lpi_state->arch_flags = 0;
 932
 933                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 934                         lpi_state->res_cnt_freq = 1;
 935
 936                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 937                         lpi_state->enable_parent_state = 0;
 938         }
 939
 940         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
 941 end:
 942         kfree(buffer.pointer);
 943         return ret;
 944 }
 945
 946 /*
 947  * flat_state_cnt - the number of composite LPI states after the process of flattening
 948  */
 949 static int flat_state_cnt;
 950
 951 /**
 952  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
 953  *
 954  * @local: local LPI state
 955  * @parent: parent LPI state
 956  * @result: composite LPI state
 957  */
 958 static bool combine_lpi_states(struct acpi_lpi_state *local,
 959                                struct acpi_lpi_state *parent,
 960                                struct acpi_lpi_state *result)
 961 {
 962         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
 963                 if (!parent->address) /* 0 means autopromotable */
 964                         return false;
 965                 result->address = local->address + parent->address;
 966         } else {
 967                 result->address = parent->address;
 968         }
 969
 970         result->min_residency = max(local->min_residency, parent->min_residency);
 971         result->wake_latency = local->wake_latency + parent->wake_latency;
 972         result->enable_parent_state = parent->enable_parent_state;
 973         result->entry_method = local->entry_method;
 974
 975         result->flags = parent->flags;
 976         result->arch_flags = parent->arch_flags;
 977         result->index = parent->index;
 978
 979         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
 980         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
 981         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
 982         return true;
 983 }
 984
 985 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
 986
 987 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
 988                                   struct acpi_lpi_state *t)
 989 {
 990         curr_level->composite_states[curr_level->composite_states_size++] = t;
 991 }
 992
 993 static int flatten_lpi_states(struct acpi_processor *pr,
 994                               struct acpi_lpi_states_array *curr_level,
 995                               struct acpi_lpi_states_array *prev_level)
 996 {
 997         int i, j, state_count = curr_level->size;
 998         struct acpi_lpi_state *p, *t = curr_level->entries;
 999
1000         curr_level->composite_states_size = 0;
1001         for (j = 0; j < state_count; j++, t++) {
1002                 struct acpi_lpi_state *flpi;
1003
1004                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1005                         continue;
1006
1007                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1008                         pr_warn("Limiting number of LPI states to max (%d)\n",
1009                                 ACPI_PROCESSOR_MAX_POWER);
1010                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1011                         break;
1012                 }
1013
1014                 flpi = &pr->power.lpi_states[flat_state_cnt];
1015
1016                 if (!prev_level) { /* leaf/processor node */
1017                         memcpy(flpi, t, sizeof(*t));
1018                         stash_composite_state(curr_level, flpi);
1019                         flat_state_cnt++;
1020                         continue;
1021                 }
1022
1023                 for (i = 0; i < prev_level->composite_states_size; i++) {
1024                         p = prev_level->composite_states[i];
1025                         if (t->index <= p->enable_parent_state &&
1026                             combine_lpi_states(p, t, flpi)) {
1027                                 stash_composite_state(curr_level, flpi);
1028                                 flat_state_cnt++;
1029                                 flpi++;
1030                         }
1031                 }
1032         }
1033
1034         kfree(curr_level->entries);
1035         return 0;
1036 }
1037
1038 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1039 {
1040         int ret, i;
1041         acpi_status status;
1042         acpi_handle handle = pr->handle, pr_ahandle;
1043         struct acpi_device *d = NULL;
1044         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1045
1046         if (!osc_pc_lpi_support_confirmed)
1047                 return -EOPNOTSUPP;
1048
1049         if (!acpi_has_method(handle, "_LPI"))
1050                 return -EINVAL;
1051
1052         flat_state_cnt = 0;
1053         prev = &info[0];
1054         curr = &info[1];
1055         handle = pr->handle;
1056         ret = acpi_processor_evaluate_lpi(handle, prev);
1057         if (ret)
1058                 return ret;
1059         flatten_lpi_states(pr, prev, NULL);
1060
1061         status = acpi_get_parent(handle, &pr_ahandle);
1062         while (ACPI_SUCCESS(status)) {
1063                 acpi_bus_get_device(pr_ahandle, &d);
1064                 handle = pr_ahandle;
1065
1066                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1067                         break;
1068
1069                 /* can be optional ? */
1070                 if (!acpi_has_method(handle, "_LPI"))
1071                         break;
1072
1073                 ret = acpi_processor_evaluate_lpi(handle, curr);
1074                 if (ret)
1075                         break;
1076
1077                 /* flatten all the LPI states in this level of hierarchy */
1078                 flatten_lpi_states(pr, curr, prev);
1079
1080                 tmp = prev, prev = curr, curr = tmp;
1081
1082                 status = acpi_get_parent(handle, &pr_ahandle);
1083         }
1084
1085         pr->power.count = flat_state_cnt;
1086         /* reset the index after flattening */
1087         for (i = 0; i < pr->power.count; i++)
1088                 pr->power.lpi_states[i].index = i;
1089
1090         /* Tell driver that _LPI is supported. */
1091         pr->flags.has_lpi = 1;
1092         pr->flags.power = 1;
1093
1094         return 0;
1095 }
1096
1097 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1098 {
1099         return -ENODEV;
1100 }
1101
1102 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1103 {
1104         return -ENODEV;
1105 }
1106
1107 /**
1108  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1109  * @dev: the target CPU
1110  * @drv: cpuidle driver containing cpuidle state info
1111  * @index: index of target state
1112  *
1113  * Return: 0 for success or negative value for error
1114  */
1115 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1116                                struct cpuidle_driver *drv, int index)
1117 {
1118         struct acpi_processor *pr;
1119         struct acpi_lpi_state *lpi;
1120
1121         pr = __this_cpu_read(processors);
1122
1123         if (unlikely(!pr))
1124                 return -EINVAL;
1125
1126         lpi = &pr->power.lpi_states[index];
1127         if (lpi->entry_method == ACPI_CSTATE_FFH)
1128                 return acpi_processor_ffh_lpi_enter(lpi);
1129
1130         return -EINVAL;
1131 }
1132
1133 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1134 {
1135         int i;
1136         struct acpi_lpi_state *lpi;
1137         struct cpuidle_state *state;
1138         struct cpuidle_driver *drv = &acpi_idle_driver;
1139
1140         if (!pr->flags.has_lpi)
1141                 return -EOPNOTSUPP;
1142
1143         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1144                 lpi = &pr->power.lpi_states[i];
1145
1146                 state = &drv->states[i];
1147                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1148                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1149                 state->exit_latency = lpi->wake_latency;
1150                 state->target_residency = lpi->min_residency;
1151                 if (lpi->arch_flags)
1152                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1153                 state->enter = acpi_idle_lpi_enter;
1154                 drv->safe_state_index = i;
1155         }
1156
1157         drv->state_count = i;
1158
1159         return 0;
1160 }
1161
1162 /**
1163  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1164  * global state data i.e. idle routines
1165  *
1166  * @pr: the ACPI processor
1167  */
1168 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1169 {
1170         int i;
1171         struct cpuidle_driver *drv = &acpi_idle_driver;
1172
1173         if (!pr->flags.power_setup_done || !pr->flags.power)
1174                 return -EINVAL;
1175
1176         drv->safe_state_index = -1;
1177         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1178                 drv->states[i].name[0] = '\0';
1179                 drv->states[i].desc[0] = '\0';
1180         }
1181
1182         if (pr->flags.has_lpi)
1183                 return acpi_processor_setup_lpi_states(pr);
1184
1185         return acpi_processor_setup_cstates(pr);
1186 }
1187
1188 /**
1189  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1190  * device i.e. per-cpu data
1191  *
1192  * @pr: the ACPI processor
1193  * @dev : the cpuidle device
1194  */
1195 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1196                                             struct cpuidle_device *dev)
1197 {
1198         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1199                 return -EINVAL;
1200
1201         dev->cpu = pr->id;
1202         if (pr->flags.has_lpi)
1203                 return acpi_processor_ffh_lpi_probe(pr->id);
1204
1205         return acpi_processor_setup_cpuidle_cx(pr, dev);
1206 }
1207
1208 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1209 {
1210         int ret;
1211
1212         ret = acpi_processor_get_lpi_info(pr);
1213         if (ret)
1214                 ret = acpi_processor_get_cstate_info(pr);
1215
1216         return ret;
1217 }
1218
1219 int acpi_processor_hotplug(struct acpi_processor *pr)
1220 {
1221         int ret = 0;
1222         struct cpuidle_device *dev;
1223
1224         if (disabled_by_idle_boot_param())
1225                 return 0;
1226
1227         if (!pr->flags.power_setup_done)
1228                 return -ENODEV;
1229
1230         dev = per_cpu(acpi_cpuidle_device, pr->id);
1231         cpuidle_pause_and_lock();
1232         cpuidle_disable_device(dev);
1233         ret = acpi_processor_get_power_info(pr);
1234         if (!ret && pr->flags.power) {
1235                 acpi_processor_setup_cpuidle_dev(pr, dev);
1236                 ret = cpuidle_enable_device(dev);
1237         }
1238         cpuidle_resume_and_unlock();
1239
1240         return ret;
1241 }
1242
1243 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1244 {
1245         int cpu;
1246         struct acpi_processor *_pr;
1247         struct cpuidle_device *dev;
1248
1249         if (disabled_by_idle_boot_param())
1250                 return 0;
1251
1252         if (!pr->flags.power_setup_done)
1253                 return -ENODEV;
1254
1255         /*
1256          * FIXME:  Design the ACPI notification to make it once per
1257          * system instead of once per-cpu.  This condition is a hack
1258          * to make the code that updates C-States be called once.
1259          */
1260
1261         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1262
1263                 /* Protect against cpu-hotplug */
1264                 get_online_cpus();
1265                 cpuidle_pause_and_lock();
1266
1267                 /* Disable all cpuidle devices */
1268                 for_each_online_cpu(cpu) {
1269                         _pr = per_cpu(processors, cpu);
1270                         if (!_pr || !_pr->flags.power_setup_done)
1271                                 continue;
1272                         dev = per_cpu(acpi_cpuidle_device, cpu);
1273                         cpuidle_disable_device(dev);
1274                 }
1275
1276                 /* Populate Updated C-state information */
1277                 acpi_processor_get_power_info(pr);
1278                 acpi_processor_setup_cpuidle_states(pr);
1279
1280                 /* Enable all cpuidle devices */
1281                 for_each_online_cpu(cpu) {
1282                         _pr = per_cpu(processors, cpu);
1283                         if (!_pr || !_pr->flags.power_setup_done)
1284                                 continue;
1285                         acpi_processor_get_power_info(_pr);
1286                         if (_pr->flags.power) {
1287                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1288                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1289                                 cpuidle_enable_device(dev);
1290                         }
1291                 }
1292                 cpuidle_resume_and_unlock();
1293                 put_online_cpus();
1294         }
1295
1296         return 0;
1297 }
1298
1299 static int acpi_processor_registered;
1300
1301 int acpi_processor_power_init(struct acpi_processor *pr)
1302 {
1303         int retval;
1304         struct cpuidle_device *dev;
1305
1306         if (disabled_by_idle_boot_param())
1307                 return 0;
1308
1309         acpi_processor_cstate_first_run_checks();
1310
1311         if (!acpi_processor_get_power_info(pr))
1312                 pr->flags.power_setup_done = 1;
1313
1314         /*
1315          * Install the idle handler if processor power management is supported.
1316          * Note that we use previously set idle handler will be used on
1317          * platforms that only support C1.
1318          */
1319         if (pr->flags.power) {
1320                 /* Register acpi_idle_driver if not already registered */
1321                 if (!acpi_processor_registered) {
1322                         acpi_processor_setup_cpuidle_states(pr);
1323                         retval = cpuidle_register_driver(&acpi_idle_driver);
1324                         if (retval)
1325                                 return retval;
1326                         pr_debug("%s registered with cpuidle\n",
1327                                  acpi_idle_driver.name);
1328                 }
1329
1330                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1331                 if (!dev)
1332                         return -ENOMEM;
1333                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1334
1335                 acpi_processor_setup_cpuidle_dev(pr, dev);
1336
1337                 /* Register per-cpu cpuidle_device. Cpuidle driver
1338                  * must already be registered before registering device
1339                  */
1340                 retval = cpuidle_register_device(dev);
1341                 if (retval) {
1342                         if (acpi_processor_registered == 0)
1343                                 cpuidle_unregister_driver(&acpi_idle_driver);
1344                         return retval;
1345                 }
1346                 acpi_processor_registered++;
1347         }
1348         return 0;
1349 }
1350
1351 int acpi_processor_power_exit(struct acpi_processor *pr)
1352 {
1353         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1354
1355         if (disabled_by_idle_boot_param())
1356                 return 0;
1357
1358         if (pr->flags.power) {
1359                 cpuidle_unregister_device(dev);
1360                 acpi_processor_registered--;
1361                 if (acpi_processor_registered == 0)
1362                         cpuidle_unregister_driver(&acpi_idle_driver);
1363         }
1364
1365         pr->flags.power_setup_done = 0;
1366         return 0;
1367 }