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