drivers/acpi/processor_idle.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_idle - idle state submodule to the ACPI processor driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  *                      - Added processor hotplug support
  10  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  11  *                      - Added support for C3 on SMP
  12  */
  13 #define pr_fmt(fmt) "ACPI: " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/acpi.h>
  17 #include <linux/dmi.h>
  18 #include <linux/sched.h>       /* need_resched() */
  19 #include <linux/sort.h>
  20 #include <linux/tick.h>
  21 #include <linux/cpuidle.h>
  22 #include <linux/cpu.h>
  23 #include <acpi/processor.h>
  24
  25 /*
  26  * Include the apic definitions for x86 to have the APIC timer related defines
  27  * available also for UP (on SMP it gets magically included via linux/smp.h).
  28  * asm/acpi.h is not an option, as it would require more include magic. Also
  29  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  30  */
  31 #ifdef CONFIG_X86
  32 #include <asm/apic.h>
  33 #include <asm/cpu.h>
  34 #endif
  35
  36 #define ACPI_PROCESSOR_CLASS            "processor"
  37 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  38 ACPI_MODULE_NAME("processor_idle");
  39
  40 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  41
  42 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  43 module_param(max_cstate, uint, 0000);
  44 static unsigned int nocst __read_mostly;
  45 module_param(nocst, uint, 0000);
  46 static int bm_check_disable __read_mostly;
  47 module_param(bm_check_disable, uint, 0000);
  48
  49 static unsigned int latency_factor __read_mostly = 2;
  50 module_param(latency_factor, uint, 0644);
  51
  52 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  53
  54 struct cpuidle_driver acpi_idle_driver = {
  55         .name =         "acpi_idle",
  56         .owner =        THIS_MODULE,
  57 };
  58
  59 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  60 static
  61 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  62
  63 static int disabled_by_idle_boot_param(void)
  64 {
  65         return boot_option_idle_override == IDLE_POLL ||
  66                 boot_option_idle_override == IDLE_HALT;
  67 }
  68
  69 /*
  70  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  71  * For now disable this. Probably a bug somewhere else.
  72  *
  73  * To skip this limit, boot/load with a large max_cstate limit.
  74  */
  75 static int set_max_cstate(const struct dmi_system_id *id)
  76 {
  77         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  78                 return 0;
  79
  80         pr_notice("%s detected - limiting to C%ld max_cstate."
  81                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  82                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  83
  84         max_cstate = (long)id->driver_data;
  85
  86         return 0;
  87 }
  88
  89 static const struct dmi_system_id processor_power_dmi_table[] = {
  90         { set_max_cstate, "Clevo 5600D", {
  91           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  92           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  93          (void *)2},
  94         { set_max_cstate, "Pavilion zv5000", {
  95           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  96           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  97          (void *)1},
  98         { set_max_cstate, "Asus L8400B", {
  99           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 100           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 101          (void *)1},
 102         {},
 103 };
 104
 105
 106 /*
 107  * Callers should disable interrupts before the call and enable
 108  * interrupts after return.
 109  */
 110 static void __cpuidle acpi_safe_halt(void)
 111 {
 112         if (!tif_need_resched()) {
 113                 safe_halt();
 114                 local_irq_disable();
 115         }
 116 }
 117
 118 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 119
 120 /*
 121  * Some BIOS implementations switch to C3 in the published C2 state.
 122  * This seems to be a common problem on AMD boxen, but other vendors
 123  * are affected too. We pick the most conservative approach: we assume
 124  * that the local APIC stops in both C2 and C3.
 125  */
 126 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 127                                    struct acpi_processor_cx *cx)
 128 {
 129         struct acpi_processor_power *pwr = &pr->power;
 130         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 131
 132         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 133                 return;
 134
 135         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 136                 type = ACPI_STATE_C1;
 137
 138         /*
 139          * Check, if one of the previous states already marked the lapic
 140          * unstable
 141          */
 142         if (pwr->timer_broadcast_on_state < state)
 143                 return;
 144
 145         if (cx->type >= type)
 146                 pr->power.timer_broadcast_on_state = state;
 147 }
 148
 149 static void __lapic_timer_propagate_broadcast(void *arg)
 150 {
 151         struct acpi_processor *pr = (struct acpi_processor *) arg;
 152
 153         if (pr->power.timer_broadcast_on_state < INT_MAX)
 154                 tick_broadcast_enable();
 155         else
 156                 tick_broadcast_disable();
 157 }
 158
 159 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 160 {
 161         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 162                                  (void *)pr, 1);
 163 }
 164
 165 /* Power(C) State timer broadcast control */
 166 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 167                                         struct acpi_processor_cx *cx)
 168 {
 169         return cx - pr->power.states >= pr->power.timer_broadcast_on_state;
 170 }
 171
 172 #else
 173
 174 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 175                                    struct acpi_processor_cx *cstate) { }
 176 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 177
 178 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 179                                         struct acpi_processor_cx *cx)
 180 {
 181         return false;
 182 }
 183
 184 #endif
 185
 186 #if defined(CONFIG_X86)
 187 static void tsc_check_state(int state)
 188 {
 189         switch (boot_cpu_data.x86_vendor) {
 190         case X86_VENDOR_HYGON:
 191         case X86_VENDOR_AMD:
 192         case X86_VENDOR_INTEL:
 193         case X86_VENDOR_CENTAUR:
 194         case X86_VENDOR_ZHAOXIN:
 195                 /*
 196                  * AMD Fam10h TSC will tick in all
 197                  * C/P/S0/S1 states when this bit is set.
 198                  */
 199                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 200                         return;
 201                 fallthrough;
 202         default:
 203                 /* TSC could halt in idle, so notify users */
 204                 if (state > ACPI_STATE_C1)
 205                         mark_tsc_unstable("TSC halts in idle");
 206         }
 207 }
 208 #else
 209 static void tsc_check_state(int state) { return; }
 210 #endif
 211
 212 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 213 {
 214
 215         if (!pr->pblk)
 216                 return -ENODEV;
 217
 218         /* if info is obtained from pblk/fadt, type equals state */
 219         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 220         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 221
 222 #ifndef CONFIG_HOTPLUG_CPU
 223         /*
 224          * Check for P_LVL2_UP flag before entering C2 and above on
 225          * an SMP system.
 226          */
 227         if ((num_online_cpus() > 1) &&
 228             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 229                 return -ENODEV;
 230 #endif
 231
 232         /* determine C2 and C3 address from pblk */
 233         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 234         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 235
 236         /* determine latencies from FADT */
 237         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 238         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 239
 240         /*
 241          * FADT specified C2 latency must be less than or equal to
 242          * 100 microseconds.
 243          */
 244         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 245                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 246                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 247                 /* invalidate C2 */
 248                 pr->power.states[ACPI_STATE_C2].address = 0;
 249         }
 250
 251         /*
 252          * FADT supplied C3 latency must be less than or equal to
 253          * 1000 microseconds.
 254          */
 255         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 256                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 257                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 258                 /* invalidate C3 */
 259                 pr->power.states[ACPI_STATE_C3].address = 0;
 260         }
 261
 262         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 264                           pr->power.states[ACPI_STATE_C2].address,
 265                           pr->power.states[ACPI_STATE_C3].address));
 266
 267         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 268                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 269                          pr->power.states[ACPI_STATE_C2].address);
 270         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 271                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 272                          pr->power.states[ACPI_STATE_C3].address);
 273
 274         return 0;
 275 }
 276
 277 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 278 {
 279         if (!pr->power.states[ACPI_STATE_C1].valid) {
 280                 /* set the first C-State to C1 */
 281                 /* all processors need to support C1 */
 282                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 283                 pr->power.states[ACPI_STATE_C1].valid = 1;
 284                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 285
 286                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 287                          ACPI_CX_DESC_LEN, "ACPI HLT");
 288         }
 289         /* the C0 state only exists as a filler in our array */
 290         pr->power.states[ACPI_STATE_C0].valid = 1;
 291         return 0;
 292 }
 293
 294 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 295 {
 296         int ret;
 297
 298         if (nocst)
 299                 return -ENODEV;
 300
 301         ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
 302         if (ret)
 303                 return ret;
 304
 305         if (!pr->power.count)
 306                 return -EFAULT;
 307
 308         pr->flags.has_cst = 1;
 309         return 0;
 310 }
 311
 312 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 313                                            struct acpi_processor_cx *cx)
 314 {
 315         static int bm_check_flag = -1;
 316         static int bm_control_flag = -1;
 317
 318
 319         if (!cx->address)
 320                 return;
 321
 322         /*
 323          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 324          * DMA transfers are used by any ISA device to avoid livelock.
 325          * Note that we could disable Type-F DMA (as recommended by
 326          * the erratum), but this is known to disrupt certain ISA
 327          * devices thus we take the conservative approach.
 328          */
 329         else if (errata.piix4.fdma) {
 330                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 331                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 332                 return;
 333         }
 334
 335         /* All the logic here assumes flags.bm_check is same across all CPUs */
 336         if (bm_check_flag == -1) {
 337                 /* Determine whether bm_check is needed based on CPU  */
 338                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 339                 bm_check_flag = pr->flags.bm_check;
 340                 bm_control_flag = pr->flags.bm_control;
 341         } else {
 342                 pr->flags.bm_check = bm_check_flag;
 343                 pr->flags.bm_control = bm_control_flag;
 344         }
 345
 346         if (pr->flags.bm_check) {
 347                 if (!pr->flags.bm_control) {
 348                         if (pr->flags.has_cst != 1) {
 349                                 /* bus mastering control is necessary */
 350                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 351                                         "C3 support requires BM control\n"));
 352                                 return;
 353                         } else {
 354                                 /* Here we enter C3 without bus mastering */
 355                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 356                                         "C3 support without BM control\n"));
 357                         }
 358                 }
 359         } else {
 360                 /*
 361                  * WBINVD should be set in fadt, for C3 state to be
 362                  * supported on when bm_check is not required.
 363                  */
 364                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 365                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 366                                           "Cache invalidation should work properly"
 367                                           " for C3 to be enabled on SMP systems\n"));
 368                         return;
 369                 }
 370         }
 371
 372         /*
 373          * Otherwise we've met all of our C3 requirements.
 374          * Normalize the C3 latency to expidite policy.  Enable
 375          * checking of bus mastering status (bm_check) so we can
 376          * use this in our C3 policy
 377          */
 378         cx->valid = 1;
 379
 380         /*
 381          * On older chipsets, BM_RLD needs to be set
 382          * in order for Bus Master activity to wake the
 383          * system from C3.  Newer chipsets handle DMA
 384          * during C3 automatically and BM_RLD is a NOP.
 385          * In either case, the proper way to
 386          * handle BM_RLD is to set it and leave it set.
 387          */
 388         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 389
 390         return;
 391 }
 392
 393 static int acpi_cst_latency_cmp(const void *a, const void *b)
 394 {
 395         const struct acpi_processor_cx *x = a, *y = b;
 396
 397         if (!(x->valid && y->valid))
 398                 return 0;
 399         if (x->latency > y->latency)
 400                 return 1;
 401         if (x->latency < y->latency)
 402                 return -1;
 403         return 0;
 404 }
 405 static void acpi_cst_latency_swap(void *a, void *b, int n)
 406 {
 407         struct acpi_processor_cx *x = a, *y = b;
 408         u32 tmp;
 409
 410         if (!(x->valid && y->valid))
 411                 return;
 412         tmp = x->latency;
 413         x->latency = y->latency;
 414         y->latency = tmp;
 415 }
 416
 417 static int acpi_processor_power_verify(struct acpi_processor *pr)
 418 {
 419         unsigned int i;
 420         unsigned int working = 0;
 421         unsigned int last_latency = 0;
 422         unsigned int last_type = 0;
 423         bool buggy_latency = false;
 424
 425         pr->power.timer_broadcast_on_state = INT_MAX;
 426
 427         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 428                 struct acpi_processor_cx *cx = &pr->power.states[i];
 429
 430                 switch (cx->type) {
 431                 case ACPI_STATE_C1:
 432                         cx->valid = 1;
 433                         break;
 434
 435                 case ACPI_STATE_C2:
 436                         if (!cx->address)
 437                                 break;
 438                         cx->valid = 1;
 439                         break;
 440
 441                 case ACPI_STATE_C3:
 442                         acpi_processor_power_verify_c3(pr, cx);
 443                         break;
 444                 }
 445                 if (!cx->valid)
 446                         continue;
 447                 if (cx->type >= last_type && cx->latency < last_latency)
 448                         buggy_latency = true;
 449                 last_latency = cx->latency;
 450                 last_type = cx->type;
 451
 452                 lapic_timer_check_state(i, pr, cx);
 453                 tsc_check_state(cx->type);
 454                 working++;
 455         }
 456
 457         if (buggy_latency) {
 458                 pr_notice("FW issue: working around C-state latencies out of order\n");
 459                 sort(&pr->power.states[1], max_cstate,
 460                      sizeof(struct acpi_processor_cx),
 461                      acpi_cst_latency_cmp,
 462                      acpi_cst_latency_swap);
 463         }
 464
 465         lapic_timer_propagate_broadcast(pr);
 466
 467         return (working);
 468 }
 469
 470 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 471 {
 472         unsigned int i;
 473         int result;
 474
 475
 476         /* NOTE: the idle thread may not be running while calling
 477          * this function */
 478
 479         /* Zero initialize all the C-states info. */
 480         memset(pr->power.states, 0, sizeof(pr->power.states));
 481
 482         result = acpi_processor_get_power_info_cst(pr);
 483         if (result == -ENODEV)
 484                 result = acpi_processor_get_power_info_fadt(pr);
 485
 486         if (result)
 487                 return result;
 488
 489         acpi_processor_get_power_info_default(pr);
 490
 491         pr->power.count = acpi_processor_power_verify(pr);
 492
 493         /*
 494          * if one state of type C2 or C3 is available, mark this
 495          * CPU as being "idle manageable"
 496          */
 497         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 498                 if (pr->power.states[i].valid) {
 499                         pr->power.count = i;
 500                         pr->flags.power = 1;
 501                 }
 502         }
 503
 504         return 0;
 505 }
 506
 507 /**
 508  * acpi_idle_bm_check - checks if bus master activity was detected
 509  */
 510 static int acpi_idle_bm_check(void)
 511 {
 512         u32 bm_status = 0;
 513
 514         if (bm_check_disable)
 515                 return 0;
 516
 517         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 518         if (bm_status)
 519                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 520         /*
 521          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 522          * the true state of bus mastering activity; forcing us to
 523          * manually check the BMIDEA bit of each IDE channel.
 524          */
 525         else if (errata.piix4.bmisx) {
 526                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 527                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 528                         bm_status = 1;
 529         }
 530         return bm_status;
 531 }
 532
 533 static void wait_for_freeze(void)
 534 {
 535 #ifdef  CONFIG_X86
 536         /* No delay is needed if we are in guest */
 537         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 538                 return;
 539         /*
 540          * Modern (>=Nehalem) Intel systems use ACPI via intel_idle,
 541          * not this code.  Assume that any Intel systems using this
 542          * are ancient and may need the dummy wait.  This also assumes
 543          * that the motivating chipset issue was Intel-only.
 544          */
 545         if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
 546                 return;
 547 #endif
 548         /*
 549          * Dummy wait op - must do something useless after P_LVL2 read
 550          * because chipsets cannot guarantee that STPCLK# signal gets
 551          * asserted in time to freeze execution properly
 552          *
 553          * This workaround has been in place since the original ACPI
 554          * implementation was merged, circa 2002.
 555          *
 556          * If a profile is pointing to this instruction, please first
 557          * consider moving your system to a more modern idle
 558          * mechanism.
 559          */
 560         inl(acpi_gbl_FADT.xpm_timer_block.address);
 561 }
 562
 563 /**
 564  * acpi_idle_do_entry - enter idle state using the appropriate method
 565  * @cx: cstate data
 566  *
 567  * Caller disables interrupt before call and enables interrupt after return.
 568  */
 569 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 570 {
 571         if (cx->entry_method == ACPI_CSTATE_FFH) {
 572                 /* Call into architectural FFH based C-state */
 573                 acpi_processor_ffh_cstate_enter(cx);
 574         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 575                 acpi_safe_halt();
 576         } else {
 577                 /* IO port based C-state */
 578                 inb(cx->address);
 579                 wait_for_freeze();
 580         }
 581 }
 582
 583 /**
 584  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 585  * @dev: the target CPU
 586  * @index: the index of suggested state
 587  */
 588 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 589 {
 590         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 591
 592         ACPI_FLUSH_CPU_CACHE();
 593
 594         while (1) {
 595
 596                 if (cx->entry_method == ACPI_CSTATE_HALT)
 597                         safe_halt();
 598                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 599                         inb(cx->address);
 600                         wait_for_freeze();
 601                 } else
 602                         return -ENODEV;
 603
 604 #if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
 605                 cond_wakeup_cpu0();
 606 #endif
 607         }
 608
 609         /* Never reached */
 610         return 0;
 611 }
 612
 613 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 614 {
 615         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 616                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 617 }
 618
 619 static int c3_cpu_count;
 620 static DEFINE_RAW_SPINLOCK(c3_lock);
 621
 622 /**
 623  * acpi_idle_enter_bm - enters C3 with proper BM handling
 624  * @drv: cpuidle driver
 625  * @pr: Target processor
 626  * @cx: Target state context
 627  * @index: index of target state
 628  */
 629 static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv,
 630                                struct acpi_processor *pr,
 631                                struct acpi_processor_cx *cx,
 632                                int index)
 633 {
 634         static struct acpi_processor_cx safe_cx = {
 635                 .entry_method = ACPI_CSTATE_HALT,
 636         };
 637
 638         /*
 639          * disable bus master
 640          * bm_check implies we need ARB_DIS
 641          * bm_control implies whether we can do ARB_DIS
 642          *
 643          * That leaves a case where bm_check is set and bm_control is not set.
 644          * In that case we cannot do much, we enter C3 without doing anything.
 645          */
 646         bool dis_bm = pr->flags.bm_control;
 647
 648         /* If we can skip BM, demote to a safe state. */
 649         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 650                 dis_bm = false;
 651                 index = drv->safe_state_index;
 652                 if (index >= 0) {
 653                         cx = this_cpu_read(acpi_cstate[index]);
 654                 } else {
 655                         cx = &safe_cx;
 656                         index = -EBUSY;
 657                 }
 658         }
 659
 660         if (dis_bm) {
 661                 raw_spin_lock(&c3_lock);
 662                 c3_cpu_count++;
 663                 /* Disable bus master arbitration when all CPUs are in C3 */
 664                 if (c3_cpu_count == num_online_cpus())
 665                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 666                 raw_spin_unlock(&c3_lock);
 667         }
 668
 669         rcu_idle_enter();
 670
 671         acpi_idle_do_entry(cx);
 672
 673         rcu_idle_exit();
 674
 675         /* Re-enable bus master arbitration */
 676         if (dis_bm) {
 677                 raw_spin_lock(&c3_lock);
 678                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 679                 c3_cpu_count--;
 680                 raw_spin_unlock(&c3_lock);
 681         }
 682
 683         return index;
 684 }
 685
 686 static int __cpuidle acpi_idle_enter(struct cpuidle_device *dev,
 687                            struct cpuidle_driver *drv, int index)
 688 {
 689         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 690         struct acpi_processor *pr;
 691
 692         pr = __this_cpu_read(processors);
 693         if (unlikely(!pr))
 694                 return -EINVAL;
 695
 696         if (cx->type != ACPI_STATE_C1) {
 697                 if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check)
 698                         return acpi_idle_enter_bm(drv, pr, cx, index);
 699
 700                 /* C2 to C1 demotion. */
 701                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 702                         index = ACPI_IDLE_STATE_START;
 703                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 704                 }
 705         }
 706
 707         if (cx->type == ACPI_STATE_C3)
 708                 ACPI_FLUSH_CPU_CACHE();
 709
 710         acpi_idle_do_entry(cx);
 711
 712         return index;
 713 }
 714
 715 static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 716                                   struct cpuidle_driver *drv, int index)
 717 {
 718         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 719
 720         if (cx->type == ACPI_STATE_C3) {
 721                 struct acpi_processor *pr = __this_cpu_read(processors);
 722
 723                 if (unlikely(!pr))
 724                         return 0;
 725
 726                 if (pr->flags.bm_check) {
 727                         u8 bm_sts_skip = cx->bm_sts_skip;
 728
 729                         /* Don't check BM_STS, do an unconditional ARB_DIS for S2IDLE */
 730                         cx->bm_sts_skip = 1;
 731                         acpi_idle_enter_bm(drv, pr, cx, index);
 732                         cx->bm_sts_skip = bm_sts_skip;
 733
 734                         return 0;
 735                 } else {
 736                         ACPI_FLUSH_CPU_CACHE();
 737                 }
 738         }
 739         acpi_idle_do_entry(cx);
 740
 741         return 0;
 742 }
 743
 744 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 745                                            struct cpuidle_device *dev)
 746 {
 747         int i, count = ACPI_IDLE_STATE_START;
 748         struct acpi_processor_cx *cx;
 749         struct cpuidle_state *state;
 750
 751         if (max_cstate == 0)
 752                 max_cstate = 1;
 753
 754         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 755                 state = &acpi_idle_driver.states[count];
 756                 cx = &pr->power.states[i];
 757
 758                 if (!cx->valid)
 759                         continue;
 760
 761                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 762
 763                 if (lapic_timer_needs_broadcast(pr, cx))
 764                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 765
 766                 if (cx->type == ACPI_STATE_C3) {
 767                         state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
 768                         if (pr->flags.bm_check)
 769                                 state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 770                 }
 771
 772                 count++;
 773                 if (count == CPUIDLE_STATE_MAX)
 774                         break;
 775         }
 776
 777         if (!count)
 778                 return -EINVAL;
 779
 780         return 0;
 781 }
 782
 783 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 784 {
 785         int i, count;
 786         struct acpi_processor_cx *cx;
 787         struct cpuidle_state *state;
 788         struct cpuidle_driver *drv = &acpi_idle_driver;
 789
 790         if (max_cstate == 0)
 791                 max_cstate = 1;
 792
 793         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 794                 cpuidle_poll_state_init(drv);
 795                 count = 1;
 796         } else {
 797                 count = 0;
 798         }
 799
 800         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 801                 cx = &pr->power.states[i];
 802
 803                 if (!cx->valid)
 804                         continue;
 805
 806                 state = &drv->states[count];
 807                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 808                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 809                 state->exit_latency = cx->latency;
 810                 state->target_residency = cx->latency * latency_factor;
 811                 state->enter = acpi_idle_enter;
 812
 813                 state->flags = 0;
 814                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 815                         state->enter_dead = acpi_idle_play_dead;
 816                         drv->safe_state_index = count;
 817                 }
 818                 /*
 819                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 820                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 821                  * particularly interesting from the suspend-to-idle angle, so
 822                  * avoid C1 and the situations in which we may need to fall back
 823                  * to it altogether.
 824                  */
 825                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 826                         state->enter_s2idle = acpi_idle_enter_s2idle;
 827
 828                 count++;
 829                 if (count == CPUIDLE_STATE_MAX)
 830                         break;
 831         }
 832
 833         drv->state_count = count;
 834
 835         if (!count)
 836                 return -EINVAL;
 837
 838         return 0;
 839 }
 840
 841 static inline void acpi_processor_cstate_first_run_checks(void)
 842 {
 843         static int first_run;
 844
 845         if (first_run)
 846                 return;
 847         dmi_check_system(processor_power_dmi_table);
 848         max_cstate = acpi_processor_cstate_check(max_cstate);
 849         if (max_cstate < ACPI_C_STATES_MAX)
 850                 pr_notice("ACPI: processor limited to max C-state %d\n",
 851                           max_cstate);
 852         first_run++;
 853
 854         if (nocst)
 855                 return;
 856
 857         acpi_processor_claim_cst_control();
 858 }
 859 #else
 860
 861 static inline int disabled_by_idle_boot_param(void) { return 0; }
 862 static inline void acpi_processor_cstate_first_run_checks(void) { }
 863 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 864 {
 865         return -ENODEV;
 866 }
 867
 868 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 869                                            struct cpuidle_device *dev)
 870 {
 871         return -EINVAL;
 872 }
 873
 874 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 875 {
 876         return -EINVAL;
 877 }
 878
 879 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 880
 881 struct acpi_lpi_states_array {
 882         unsigned int size;
 883         unsigned int composite_states_size;
 884         struct acpi_lpi_state *entries;
 885         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 886 };
 887
 888 static int obj_get_integer(union acpi_object *obj, u32 *value)
 889 {
 890         if (obj->type != ACPI_TYPE_INTEGER)
 891                 return -EINVAL;
 892
 893         *value = obj->integer.value;
 894         return 0;
 895 }
 896
 897 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 898                                        struct acpi_lpi_states_array *info)
 899 {
 900         acpi_status status;
 901         int ret = 0;
 902         int pkg_count, state_idx = 1, loop;
 903         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 904         union acpi_object *lpi_data;
 905         struct acpi_lpi_state *lpi_state;
 906
 907         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 908         if (ACPI_FAILURE(status)) {
 909                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 910                 return -ENODEV;
 911         }
 912
 913         lpi_data = buffer.pointer;
 914
 915         /* There must be at least 4 elements = 3 elements + 1 package */
 916         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 917             lpi_data->package.count < 4) {
 918                 pr_debug("not enough elements in _LPI\n");
 919                 ret = -ENODATA;
 920                 goto end;
 921         }
 922
 923         pkg_count = lpi_data->package.elements[2].integer.value;
 924
 925         /* Validate number of power states. */
 926         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 927                 pr_debug("count given by _LPI is not valid\n");
 928                 ret = -ENODATA;
 929                 goto end;
 930         }
 931
 932         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 933         if (!lpi_state) {
 934                 ret = -ENOMEM;
 935                 goto end;
 936         }
 937
 938         info->size = pkg_count;
 939         info->entries = lpi_state;
 940
 941         /* LPI States start at index 3 */
 942         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 943                 union acpi_object *element, *pkg_elem, *obj;
 944
 945                 element = &lpi_data->package.elements[loop];
 946                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
 947                         continue;
 948
 949                 pkg_elem = element->package.elements;
 950
 951                 obj = pkg_elem + 6;
 952                 if (obj->type == ACPI_TYPE_BUFFER) {
 953                         struct acpi_power_register *reg;
 954
 955                         reg = (struct acpi_power_register *)obj->buffer.pointer;
 956                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 957                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
 958                                 continue;
 959
 960                         lpi_state->address = reg->address;
 961                         lpi_state->entry_method =
 962                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
 963                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
 964                 } else if (obj->type == ACPI_TYPE_INTEGER) {
 965                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
 966                         lpi_state->address = obj->integer.value;
 967                 } else {
 968                         continue;
 969                 }
 970
 971                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
 972
 973                 obj = pkg_elem + 9;
 974                 if (obj->type == ACPI_TYPE_STRING)
 975                         strlcpy(lpi_state->desc, obj->string.pointer,
 976                                 ACPI_CX_DESC_LEN);
 977
 978                 lpi_state->index = state_idx;
 979                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
 980                         pr_debug("No min. residency found, assuming 10 us\n");
 981                         lpi_state->min_residency = 10;
 982                 }
 983
 984                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
 985                         pr_debug("No wakeup residency found, assuming 10 us\n");
 986                         lpi_state->wake_latency = 10;
 987                 }
 988
 989                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
 990                         lpi_state->flags = 0;
 991
 992                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
 993                         lpi_state->arch_flags = 0;
 994
 995                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
 996                         lpi_state->res_cnt_freq = 1;
 997
 998                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
 999                         lpi_state->enable_parent_state = 0;
1000         }
1001
1002         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1003 end:
1004         kfree(buffer.pointer);
1005         return ret;
1006 }
1007
1008 /*
1009  * flat_state_cnt - the number of composite LPI states after the process of flattening
1010  */
1011 static int flat_state_cnt;
1012
1013 /**
1014  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1015  *
1016  * @local: local LPI state
1017  * @parent: parent LPI state
1018  * @result: composite LPI state
1019  */
1020 static bool combine_lpi_states(struct acpi_lpi_state *local,
1021                                struct acpi_lpi_state *parent,
1022                                struct acpi_lpi_state *result)
1023 {
1024         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1025                 if (!parent->address) /* 0 means autopromotable */
1026                         return false;
1027                 result->address = local->address + parent->address;
1028         } else {
1029                 result->address = parent->address;
1030         }
1031
1032         result->min_residency = max(local->min_residency, parent->min_residency);
1033         result->wake_latency = local->wake_latency + parent->wake_latency;
1034         result->enable_parent_state = parent->enable_parent_state;
1035         result->entry_method = local->entry_method;
1036
1037         result->flags = parent->flags;
1038         result->arch_flags = parent->arch_flags;
1039         result->index = parent->index;
1040
1041         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1042         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1043         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1044         return true;
1045 }
1046
1047 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1048
1049 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1050                                   struct acpi_lpi_state *t)
1051 {
1052         curr_level->composite_states[curr_level->composite_states_size++] = t;
1053 }
1054
1055 static int flatten_lpi_states(struct acpi_processor *pr,
1056                               struct acpi_lpi_states_array *curr_level,
1057                               struct acpi_lpi_states_array *prev_level)
1058 {
1059         int i, j, state_count = curr_level->size;
1060         struct acpi_lpi_state *p, *t = curr_level->entries;
1061
1062         curr_level->composite_states_size = 0;
1063         for (j = 0; j < state_count; j++, t++) {
1064                 struct acpi_lpi_state *flpi;
1065
1066                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1067                         continue;
1068
1069                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1070                         pr_warn("Limiting number of LPI states to max (%d)\n",
1071                                 ACPI_PROCESSOR_MAX_POWER);
1072                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1073                         break;
1074                 }
1075
1076                 flpi = &pr->power.lpi_states[flat_state_cnt];
1077
1078                 if (!prev_level) { /* leaf/processor node */
1079                         memcpy(flpi, t, sizeof(*t));
1080                         stash_composite_state(curr_level, flpi);
1081                         flat_state_cnt++;
1082                         continue;
1083                 }
1084
1085                 for (i = 0; i < prev_level->composite_states_size; i++) {
1086                         p = prev_level->composite_states[i];
1087                         if (t->index <= p->enable_parent_state &&
1088                             combine_lpi_states(p, t, flpi)) {
1089                                 stash_composite_state(curr_level, flpi);
1090                                 flat_state_cnt++;
1091                                 flpi++;
1092                         }
1093                 }
1094         }
1095
1096         kfree(curr_level->entries);
1097         return 0;
1098 }
1099
1100 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1101 {
1102         return -EOPNOTSUPP;
1103 }
1104
1105 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1106 {
1107         int ret, i;
1108         acpi_status status;
1109         acpi_handle handle = pr->handle, pr_ahandle;
1110         struct acpi_device *d = NULL;
1111         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1112
1113         /* make sure our architecture has support */
1114         ret = acpi_processor_ffh_lpi_probe(pr->id);
1115         if (ret == -EOPNOTSUPP)
1116                 return ret;
1117
1118         if (!osc_pc_lpi_support_confirmed)
1119                 return -EOPNOTSUPP;
1120
1121         if (!acpi_has_method(handle, "_LPI"))
1122                 return -EINVAL;
1123
1124         flat_state_cnt = 0;
1125         prev = &info[0];
1126         curr = &info[1];
1127         handle = pr->handle;
1128         ret = acpi_processor_evaluate_lpi(handle, prev);
1129         if (ret)
1130                 return ret;
1131         flatten_lpi_states(pr, prev, NULL);
1132
1133         status = acpi_get_parent(handle, &pr_ahandle);
1134         while (ACPI_SUCCESS(status)) {
1135                 acpi_bus_get_device(pr_ahandle, &d);
1136                 handle = pr_ahandle;
1137
1138                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1139                         break;
1140
1141                 /* can be optional ? */
1142                 if (!acpi_has_method(handle, "_LPI"))
1143                         break;
1144
1145                 ret = acpi_processor_evaluate_lpi(handle, curr);
1146                 if (ret)
1147                         break;
1148
1149                 /* flatten all the LPI states in this level of hierarchy */
1150                 flatten_lpi_states(pr, curr, prev);
1151
1152                 tmp = prev, prev = curr, curr = tmp;
1153
1154                 status = acpi_get_parent(handle, &pr_ahandle);
1155         }
1156
1157         pr->power.count = flat_state_cnt;
1158         /* reset the index after flattening */
1159         for (i = 0; i < pr->power.count; i++)
1160                 pr->power.lpi_states[i].index = i;
1161
1162         /* Tell driver that _LPI is supported. */
1163         pr->flags.has_lpi = 1;
1164         pr->flags.power = 1;
1165
1166         return 0;
1167 }
1168
1169 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1170 {
1171         return -ENODEV;
1172 }
1173
1174 /**
1175  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1176  * @dev: the target CPU
1177  * @drv: cpuidle driver containing cpuidle state info
1178  * @index: index of target state
1179  *
1180  * Return: 0 for success or negative value for error
1181  */
1182 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1183                                struct cpuidle_driver *drv, int index)
1184 {
1185         struct acpi_processor *pr;
1186         struct acpi_lpi_state *lpi;
1187
1188         pr = __this_cpu_read(processors);
1189
1190         if (unlikely(!pr))
1191                 return -EINVAL;
1192
1193         lpi = &pr->power.lpi_states[index];
1194         if (lpi->entry_method == ACPI_CSTATE_FFH)
1195                 return acpi_processor_ffh_lpi_enter(lpi);
1196
1197         return -EINVAL;
1198 }
1199
1200 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1201 {
1202         int i;
1203         struct acpi_lpi_state *lpi;
1204         struct cpuidle_state *state;
1205         struct cpuidle_driver *drv = &acpi_idle_driver;
1206
1207         if (!pr->flags.has_lpi)
1208                 return -EOPNOTSUPP;
1209
1210         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1211                 lpi = &pr->power.lpi_states[i];
1212
1213                 state = &drv->states[i];
1214                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1215                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1216                 state->exit_latency = lpi->wake_latency;
1217                 state->target_residency = lpi->min_residency;
1218                 if (lpi->arch_flags)
1219                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1220                 state->enter = acpi_idle_lpi_enter;
1221                 drv->safe_state_index = i;
1222         }
1223
1224         drv->state_count = i;
1225
1226         return 0;
1227 }
1228
1229 /**
1230  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1231  * global state data i.e. idle routines
1232  *
1233  * @pr: the ACPI processor
1234  */
1235 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1236 {
1237         int i;
1238         struct cpuidle_driver *drv = &acpi_idle_driver;
1239
1240         if (!pr->flags.power_setup_done || !pr->flags.power)
1241                 return -EINVAL;
1242
1243         drv->safe_state_index = -1;
1244         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1245                 drv->states[i].name[0] = '\0';
1246                 drv->states[i].desc[0] = '\0';
1247         }
1248
1249         if (pr->flags.has_lpi)
1250                 return acpi_processor_setup_lpi_states(pr);
1251
1252         return acpi_processor_setup_cstates(pr);
1253 }
1254
1255 /**
1256  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1257  * device i.e. per-cpu data
1258  *
1259  * @pr: the ACPI processor
1260  * @dev : the cpuidle device
1261  */
1262 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1263                                             struct cpuidle_device *dev)
1264 {
1265         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1266                 return -EINVAL;
1267
1268         dev->cpu = pr->id;
1269         if (pr->flags.has_lpi)
1270                 return acpi_processor_ffh_lpi_probe(pr->id);
1271
1272         return acpi_processor_setup_cpuidle_cx(pr, dev);
1273 }
1274
1275 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1276 {
1277         int ret;
1278
1279         ret = acpi_processor_get_lpi_info(pr);
1280         if (ret)
1281                 ret = acpi_processor_get_cstate_info(pr);
1282
1283         return ret;
1284 }
1285
1286 int acpi_processor_hotplug(struct acpi_processor *pr)
1287 {
1288         int ret = 0;
1289         struct cpuidle_device *dev;
1290
1291         if (disabled_by_idle_boot_param())
1292                 return 0;
1293
1294         if (!pr->flags.power_setup_done)
1295                 return -ENODEV;
1296
1297         dev = per_cpu(acpi_cpuidle_device, pr->id);
1298         cpuidle_pause_and_lock();
1299         cpuidle_disable_device(dev);
1300         ret = acpi_processor_get_power_info(pr);
1301         if (!ret && pr->flags.power) {
1302                 acpi_processor_setup_cpuidle_dev(pr, dev);
1303                 ret = cpuidle_enable_device(dev);
1304         }
1305         cpuidle_resume_and_unlock();
1306
1307         return ret;
1308 }
1309
1310 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1311 {
1312         int cpu;
1313         struct acpi_processor *_pr;
1314         struct cpuidle_device *dev;
1315
1316         if (disabled_by_idle_boot_param())
1317                 return 0;
1318
1319         if (!pr->flags.power_setup_done)
1320                 return -ENODEV;
1321
1322         /*
1323          * FIXME:  Design the ACPI notification to make it once per
1324          * system instead of once per-cpu.  This condition is a hack
1325          * to make the code that updates C-States be called once.
1326          */
1327
1328         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1329
1330                 /* Protect against cpu-hotplug */
1331                 get_online_cpus();
1332                 cpuidle_pause_and_lock();
1333
1334                 /* Disable all cpuidle devices */
1335                 for_each_online_cpu(cpu) {
1336                         _pr = per_cpu(processors, cpu);
1337                         if (!_pr || !_pr->flags.power_setup_done)
1338                                 continue;
1339                         dev = per_cpu(acpi_cpuidle_device, cpu);
1340                         cpuidle_disable_device(dev);
1341                 }
1342
1343                 /* Populate Updated C-state information */
1344                 acpi_processor_get_power_info(pr);
1345                 acpi_processor_setup_cpuidle_states(pr);
1346
1347                 /* Enable all cpuidle devices */
1348                 for_each_online_cpu(cpu) {
1349                         _pr = per_cpu(processors, cpu);
1350                         if (!_pr || !_pr->flags.power_setup_done)
1351                                 continue;
1352                         acpi_processor_get_power_info(_pr);
1353                         if (_pr->flags.power) {
1354                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1355                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1356                                 cpuidle_enable_device(dev);
1357                         }
1358                 }
1359                 cpuidle_resume_and_unlock();
1360                 put_online_cpus();
1361         }
1362
1363         return 0;
1364 }
1365
1366 static int acpi_processor_registered;
1367
1368 int acpi_processor_power_init(struct acpi_processor *pr)
1369 {
1370         int retval;
1371         struct cpuidle_device *dev;
1372
1373         if (disabled_by_idle_boot_param())
1374                 return 0;
1375
1376         acpi_processor_cstate_first_run_checks();
1377
1378         if (!acpi_processor_get_power_info(pr))
1379                 pr->flags.power_setup_done = 1;
1380
1381         /*
1382          * Install the idle handler if processor power management is supported.
1383          * Note that we use previously set idle handler will be used on
1384          * platforms that only support C1.
1385          */
1386         if (pr->flags.power) {
1387                 /* Register acpi_idle_driver if not already registered */
1388                 if (!acpi_processor_registered) {
1389                         acpi_processor_setup_cpuidle_states(pr);
1390                         retval = cpuidle_register_driver(&acpi_idle_driver);
1391                         if (retval)
1392                                 return retval;
1393                         pr_debug("%s registered with cpuidle\n",
1394                                  acpi_idle_driver.name);
1395                 }
1396
1397                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1398                 if (!dev)
1399                         return -ENOMEM;
1400                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1401
1402                 acpi_processor_setup_cpuidle_dev(pr, dev);
1403
1404                 /* Register per-cpu cpuidle_device. Cpuidle driver
1405                  * must already be registered before registering device
1406                  */
1407                 retval = cpuidle_register_device(dev);
1408                 if (retval) {
1409                         if (acpi_processor_registered == 0)
1410                                 cpuidle_unregister_driver(&acpi_idle_driver);
1411                         return retval;
1412                 }
1413                 acpi_processor_registered++;
1414         }
1415         return 0;
1416 }
1417
1418 int acpi_processor_power_exit(struct acpi_processor *pr)
1419 {
1420         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1421
1422         if (disabled_by_idle_boot_param())
1423                 return 0;
1424
1425         if (pr->flags.power) {
1426                 cpuidle_unregister_device(dev);
1427                 acpi_processor_registered--;
1428                 if (acpi_processor_registered == 0)
1429                         cpuidle_unregister_driver(&acpi_idle_driver);
1430
1431                 kfree(dev);
1432         }
1433
1434         pr->flags.power_setup_done = 0;
1435         return 0;
1436 }