drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26 #define pr_fmt(fmt) "ACPI: " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <linux/sched.h>       /* need_resched() */
  32 #include <linux/tick.h>
  33 #include <linux/cpuidle.h>
  34 #include <linux/cpu.h>
  35 #include <acpi/processor.h>
  36
  37 /*
  38  * Include the apic definitions for x86 to have the APIC timer related defines
  39  * available also for UP (on SMP it gets magically included via linux/smp.h).
  40  * asm/acpi.h is not an option, as it would require more include magic. Also
  41  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  42  */
  43 #ifdef CONFIG_X86
  44 #include <asm/apic.h>
  45 #endif
  46
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("processor_idle");
  50
  51 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  52
  53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  54 module_param(max_cstate, uint, 0000);
  55 static unsigned int nocst __read_mostly;
  56 module_param(nocst, uint, 0000);
  57 static int bm_check_disable __read_mostly;
  58 module_param(bm_check_disable, uint, 0000);
  59
  60 static unsigned int latency_factor __read_mostly = 2;
  61 module_param(latency_factor, uint, 0644);
  62
  63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  64
  65 struct cpuidle_driver acpi_idle_driver = {
  66         .name =         "acpi_idle",
  67         .owner =        THIS_MODULE,
  68 };
  69
  70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  71 static
  72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  73
  74 static int disabled_by_idle_boot_param(void)
  75 {
  76         return boot_option_idle_override == IDLE_POLL ||
  77                 boot_option_idle_override == IDLE_HALT;
  78 }
  79
  80 /*
  81  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  82  * For now disable this. Probably a bug somewhere else.
  83  *
  84  * To skip this limit, boot/load with a large max_cstate limit.
  85  */
  86 static int set_max_cstate(const struct dmi_system_id *id)
  87 {
  88         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  89                 return 0;
  90
  91         pr_notice("%s detected - limiting to C%ld max_cstate."
  92                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  93                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  94
  95         max_cstate = (long)id->driver_data;
  96
  97         return 0;
  98 }
  99
 100 static const struct dmi_system_id processor_power_dmi_table[] = {
 101         { set_max_cstate, "Clevo 5600D", {
 102           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 103           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 104          (void *)2},
 105         { set_max_cstate, "Pavilion zv5000", {
 106           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 107           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 108          (void *)1},
 109         { set_max_cstate, "Asus L8400B", {
 110           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 111           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 112          (void *)1},
 113         {},
 114 };
 115
 116
 117 /*
 118  * Callers should disable interrupts before the call and enable
 119  * interrupts after return.
 120  */
 121 static void __cpuidle acpi_safe_halt(void)
 122 {
 123         if (!tif_need_resched()) {
 124                 safe_halt();
 125                 local_irq_disable();
 126         }
 127 }
 128
 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 130
 131 /*
 132  * Some BIOS implementations switch to C3 in the published C2 state.
 133  * This seems to be a common problem on AMD boxen, but other vendors
 134  * are affected too. We pick the most conservative approach: we assume
 135  * that the local APIC stops in both C2 and C3.
 136  */
 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 138                                    struct acpi_processor_cx *cx)
 139 {
 140         struct acpi_processor_power *pwr = &pr->power;
 141         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 142
 143         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 144                 return;
 145
 146         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 147                 type = ACPI_STATE_C1;
 148
 149         /*
 150          * Check, if one of the previous states already marked the lapic
 151          * unstable
 152          */
 153         if (pwr->timer_broadcast_on_state < state)
 154                 return;
 155
 156         if (cx->type >= type)
 157                 pr->power.timer_broadcast_on_state = state;
 158 }
 159
 160 static void __lapic_timer_propagate_broadcast(void *arg)
 161 {
 162         struct acpi_processor *pr = (struct acpi_processor *) arg;
 163
 164         if (pr->power.timer_broadcast_on_state < INT_MAX)
 165                 tick_broadcast_enable();
 166         else
 167                 tick_broadcast_disable();
 168 }
 169
 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 171 {
 172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 173                                  (void *)pr, 1);
 174 }
 175
 176 /* Power(C) State timer broadcast control */
 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 178                                        struct acpi_processor_cx *cx,
 179                                        int broadcast)
 180 {
 181         int state = cx - pr->power.states;
 182
 183         if (state >= pr->power.timer_broadcast_on_state) {
 184                 if (broadcast)
 185                         tick_broadcast_enter();
 186                 else
 187                         tick_broadcast_exit();
 188         }
 189 }
 190
 191 #else
 192
 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 194                                    struct acpi_processor_cx *cstate) { }
 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 197                                        struct acpi_processor_cx *cx,
 198                                        int broadcast)
 199 {
 200 }
 201
 202 #endif
 203
 204 #if defined(CONFIG_X86)
 205 static void tsc_check_state(int state)
 206 {
 207         switch (boot_cpu_data.x86_vendor) {
 208         case X86_VENDOR_AMD:
 209         case X86_VENDOR_INTEL:
 210         case X86_VENDOR_CENTAUR:
 211                 /*
 212                  * AMD Fam10h TSC will tick in all
 213                  * C/P/S0/S1 states when this bit is set.
 214                  */
 215                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 216                         return;
 217
 218                 /*FALL THROUGH*/
 219         default:
 220                 /* TSC could halt in idle, so notify users */
 221                 if (state > ACPI_STATE_C1)
 222                         mark_tsc_unstable("TSC halts in idle");
 223         }
 224 }
 225 #else
 226 static void tsc_check_state(int state) { return; }
 227 #endif
 228
 229 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 230 {
 231
 232         if (!pr->pblk)
 233                 return -ENODEV;
 234
 235         /* if info is obtained from pblk/fadt, type equals state */
 236         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 237         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 238
 239 #ifndef CONFIG_HOTPLUG_CPU
 240         /*
 241          * Check for P_LVL2_UP flag before entering C2 and above on
 242          * an SMP system.
 243          */
 244         if ((num_online_cpus() > 1) &&
 245             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 246                 return -ENODEV;
 247 #endif
 248
 249         /* determine C2 and C3 address from pblk */
 250         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 251         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 252
 253         /* determine latencies from FADT */
 254         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 255         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 256
 257         /*
 258          * FADT specified C2 latency must be less than or equal to
 259          * 100 microseconds.
 260          */
 261         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 264                 /* invalidate C2 */
 265                 pr->power.states[ACPI_STATE_C2].address = 0;
 266         }
 267
 268         /*
 269          * FADT supplied C3 latency must be less than or equal to
 270          * 1000 microseconds.
 271          */
 272         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 273                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 274                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 275                 /* invalidate C3 */
 276                 pr->power.states[ACPI_STATE_C3].address = 0;
 277         }
 278
 279         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 280                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 281                           pr->power.states[ACPI_STATE_C2].address,
 282                           pr->power.states[ACPI_STATE_C3].address));
 283
 284         return 0;
 285 }
 286
 287 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 288 {
 289         if (!pr->power.states[ACPI_STATE_C1].valid) {
 290                 /* set the first C-State to C1 */
 291                 /* all processors need to support C1 */
 292                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 293                 pr->power.states[ACPI_STATE_C1].valid = 1;
 294                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 295         }
 296         /* the C0 state only exists as a filler in our array */
 297         pr->power.states[ACPI_STATE_C0].valid = 1;
 298         return 0;
 299 }
 300
 301 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 302 {
 303         acpi_status status;
 304         u64 count;
 305         int current_count;
 306         int i, ret = 0;
 307         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 308         union acpi_object *cst;
 309
 310         if (nocst)
 311                 return -ENODEV;
 312
 313         current_count = 0;
 314
 315         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 316         if (ACPI_FAILURE(status)) {
 317                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 318                 return -ENODEV;
 319         }
 320
 321         cst = buffer.pointer;
 322
 323         /* There must be at least 2 elements */
 324         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 325                 pr_err("not enough elements in _CST\n");
 326                 ret = -EFAULT;
 327                 goto end;
 328         }
 329
 330         count = cst->package.elements[0].integer.value;
 331
 332         /* Validate number of power states. */
 333         if (count < 1 || count != cst->package.count - 1) {
 334                 pr_err("count given by _CST is not valid\n");
 335                 ret = -EFAULT;
 336                 goto end;
 337         }
 338
 339         /* Tell driver that at least _CST is supported. */
 340         pr->flags.has_cst = 1;
 341
 342         for (i = 1; i <= count; i++) {
 343                 union acpi_object *element;
 344                 union acpi_object *obj;
 345                 struct acpi_power_register *reg;
 346                 struct acpi_processor_cx cx;
 347
 348                 memset(&cx, 0, sizeof(cx));
 349
 350                 element = &(cst->package.elements[i]);
 351                 if (element->type != ACPI_TYPE_PACKAGE)
 352                         continue;
 353
 354                 if (element->package.count != 4)
 355                         continue;
 356
 357                 obj = &(element->package.elements[0]);
 358
 359                 if (obj->type != ACPI_TYPE_BUFFER)
 360                         continue;
 361
 362                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 363
 364                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 365                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 366                         continue;
 367
 368                 /* There should be an easy way to extract an integer... */
 369                 obj = &(element->package.elements[1]);
 370                 if (obj->type != ACPI_TYPE_INTEGER)
 371                         continue;
 372
 373                 cx.type = obj->integer.value;
 374                 /*
 375                  * Some buggy BIOSes won't list C1 in _CST -
 376                  * Let acpi_processor_get_power_info_default() handle them later
 377                  */
 378                 if (i == 1 && cx.type != ACPI_STATE_C1)
 379                         current_count++;
 380
 381                 cx.address = reg->address;
 382                 cx.index = current_count + 1;
 383
 384                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 385                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 386                         if (acpi_processor_ffh_cstate_probe
 387                                         (pr->id, &cx, reg) == 0) {
 388                                 cx.entry_method = ACPI_CSTATE_FFH;
 389                         } else if (cx.type == ACPI_STATE_C1) {
 390                                 /*
 391                                  * C1 is a special case where FIXED_HARDWARE
 392                                  * can be handled in non-MWAIT way as well.
 393                                  * In that case, save this _CST entry info.
 394                                  * Otherwise, ignore this info and continue.
 395                                  */
 396                                 cx.entry_method = ACPI_CSTATE_HALT;
 397                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 398                         } else {
 399                                 continue;
 400                         }
 401                         if (cx.type == ACPI_STATE_C1 &&
 402                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 403                                 /*
 404                                  * In most cases the C1 space_id obtained from
 405                                  * _CST object is FIXED_HARDWARE access mode.
 406                                  * But when the option of idle=halt is added,
 407                                  * the entry_method type should be changed from
 408                                  * CSTATE_FFH to CSTATE_HALT.
 409                                  * When the option of idle=nomwait is added,
 410                                  * the C1 entry_method type should be
 411                                  * CSTATE_HALT.
 412                                  */
 413                                 cx.entry_method = ACPI_CSTATE_HALT;
 414                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 415                         }
 416                 } else {
 417                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 418                                  cx.address);
 419                 }
 420
 421                 if (cx.type == ACPI_STATE_C1) {
 422                         cx.valid = 1;
 423                 }
 424
 425                 obj = &(element->package.elements[2]);
 426                 if (obj->type != ACPI_TYPE_INTEGER)
 427                         continue;
 428
 429                 cx.latency = obj->integer.value;
 430
 431                 obj = &(element->package.elements[3]);
 432                 if (obj->type != ACPI_TYPE_INTEGER)
 433                         continue;
 434
 435                 current_count++;
 436                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 437
 438                 /*
 439                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 440                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 441                  */
 442                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 443                         pr_warn("Limiting number of power states to max (%d)\n",
 444                                 ACPI_PROCESSOR_MAX_POWER);
 445                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 446                         break;
 447                 }
 448         }
 449
 450         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 451                           current_count));
 452
 453         /* Validate number of power states discovered */
 454         if (current_count < 2)
 455                 ret = -EFAULT;
 456
 457       end:
 458         kfree(buffer.pointer);
 459
 460         return ret;
 461 }
 462
 463 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 464                                            struct acpi_processor_cx *cx)
 465 {
 466         static int bm_check_flag = -1;
 467         static int bm_control_flag = -1;
 468
 469
 470         if (!cx->address)
 471                 return;
 472
 473         /*
 474          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 475          * DMA transfers are used by any ISA device to avoid livelock.
 476          * Note that we could disable Type-F DMA (as recommended by
 477          * the erratum), but this is known to disrupt certain ISA
 478          * devices thus we take the conservative approach.
 479          */
 480         else if (errata.piix4.fdma) {
 481                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 482                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 483                 return;
 484         }
 485
 486         /* All the logic here assumes flags.bm_check is same across all CPUs */
 487         if (bm_check_flag == -1) {
 488                 /* Determine whether bm_check is needed based on CPU  */
 489                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 490                 bm_check_flag = pr->flags.bm_check;
 491                 bm_control_flag = pr->flags.bm_control;
 492         } else {
 493                 pr->flags.bm_check = bm_check_flag;
 494                 pr->flags.bm_control = bm_control_flag;
 495         }
 496
 497         if (pr->flags.bm_check) {
 498                 if (!pr->flags.bm_control) {
 499                         if (pr->flags.has_cst != 1) {
 500                                 /* bus mastering control is necessary */
 501                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 502                                         "C3 support requires BM control\n"));
 503                                 return;
 504                         } else {
 505                                 /* Here we enter C3 without bus mastering */
 506                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 507                                         "C3 support without BM control\n"));
 508                         }
 509                 }
 510         } else {
 511                 /*
 512                  * WBINVD should be set in fadt, for C3 state to be
 513                  * supported on when bm_check is not required.
 514                  */
 515                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 516                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 517                                           "Cache invalidation should work properly"
 518                                           " for C3 to be enabled on SMP systems\n"));
 519                         return;
 520                 }
 521         }
 522
 523         /*
 524          * Otherwise we've met all of our C3 requirements.
 525          * Normalize the C3 latency to expidite policy.  Enable
 526          * checking of bus mastering status (bm_check) so we can
 527          * use this in our C3 policy
 528          */
 529         cx->valid = 1;
 530
 531         /*
 532          * On older chipsets, BM_RLD needs to be set
 533          * in order for Bus Master activity to wake the
 534          * system from C3.  Newer chipsets handle DMA
 535          * during C3 automatically and BM_RLD is a NOP.
 536          * In either case, the proper way to
 537          * handle BM_RLD is to set it and leave it set.
 538          */
 539         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 540
 541         return;
 542 }
 543
 544 static int acpi_processor_power_verify(struct acpi_processor *pr)
 545 {
 546         unsigned int i;
 547         unsigned int working = 0;
 548
 549         pr->power.timer_broadcast_on_state = INT_MAX;
 550
 551         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 552                 struct acpi_processor_cx *cx = &pr->power.states[i];
 553
 554                 switch (cx->type) {
 555                 case ACPI_STATE_C1:
 556                         cx->valid = 1;
 557                         break;
 558
 559                 case ACPI_STATE_C2:
 560                         if (!cx->address)
 561                                 break;
 562                         cx->valid = 1;
 563                         break;
 564
 565                 case ACPI_STATE_C3:
 566                         acpi_processor_power_verify_c3(pr, cx);
 567                         break;
 568                 }
 569                 if (!cx->valid)
 570                         continue;
 571
 572                 lapic_timer_check_state(i, pr, cx);
 573                 tsc_check_state(cx->type);
 574                 working++;
 575         }
 576
 577         lapic_timer_propagate_broadcast(pr);
 578
 579         return (working);
 580 }
 581
 582 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 583 {
 584         unsigned int i;
 585         int result;
 586
 587
 588         /* NOTE: the idle thread may not be running while calling
 589          * this function */
 590
 591         /* Zero initialize all the C-states info. */
 592         memset(pr->power.states, 0, sizeof(pr->power.states));
 593
 594         result = acpi_processor_get_power_info_cst(pr);
 595         if (result == -ENODEV)
 596                 result = acpi_processor_get_power_info_fadt(pr);
 597
 598         if (result)
 599                 return result;
 600
 601         acpi_processor_get_power_info_default(pr);
 602
 603         pr->power.count = acpi_processor_power_verify(pr);
 604
 605         /*
 606          * if one state of type C2 or C3 is available, mark this
 607          * CPU as being "idle manageable"
 608          */
 609         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 610                 if (pr->power.states[i].valid) {
 611                         pr->power.count = i;
 612                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 613                                 pr->flags.power = 1;
 614                 }
 615         }
 616
 617         return 0;
 618 }
 619
 620 /**
 621  * acpi_idle_bm_check - checks if bus master activity was detected
 622  */
 623 static int acpi_idle_bm_check(void)
 624 {
 625         u32 bm_status = 0;
 626
 627         if (bm_check_disable)
 628                 return 0;
 629
 630         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 631         if (bm_status)
 632                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 633         /*
 634          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 635          * the true state of bus mastering activity; forcing us to
 636          * manually check the BMIDEA bit of each IDE channel.
 637          */
 638         else if (errata.piix4.bmisx) {
 639                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 640                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 641                         bm_status = 1;
 642         }
 643         return bm_status;
 644 }
 645
 646 /**
 647  * acpi_idle_do_entry - enter idle state using the appropriate method
 648  * @cx: cstate data
 649  *
 650  * Caller disables interrupt before call and enables interrupt after return.
 651  */
 652 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 653 {
 654         if (cx->entry_method == ACPI_CSTATE_FFH) {
 655                 /* Call into architectural FFH based C-state */
 656                 acpi_processor_ffh_cstate_enter(cx);
 657         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 658                 acpi_safe_halt();
 659         } else {
 660                 /* IO port based C-state */
 661                 inb(cx->address);
 662                 /* Dummy wait op - must do something useless after P_LVL2 read
 663                    because chipsets cannot guarantee that STPCLK# signal
 664                    gets asserted in time to freeze execution properly. */
 665                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 666         }
 667 }
 668
 669 /**
 670  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 671  * @dev: the target CPU
 672  * @index: the index of suggested state
 673  */
 674 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 675 {
 676         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 677
 678         ACPI_FLUSH_CPU_CACHE();
 679
 680         while (1) {
 681
 682                 if (cx->entry_method == ACPI_CSTATE_HALT)
 683                         safe_halt();
 684                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 685                         inb(cx->address);
 686                         /* See comment in acpi_idle_do_entry() */
 687                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 688                 } else
 689                         return -ENODEV;
 690         }
 691
 692         /* Never reached */
 693         return 0;
 694 }
 695
 696 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 697 {
 698         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 699                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 700 }
 701
 702 static int c3_cpu_count;
 703 static DEFINE_RAW_SPINLOCK(c3_lock);
 704
 705 /**
 706  * acpi_idle_enter_bm - enters C3 with proper BM handling
 707  * @pr: Target processor
 708  * @cx: Target state context
 709  * @timer_bc: Whether or not to change timer mode to broadcast
 710  */
 711 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 712                                struct acpi_processor_cx *cx, bool timer_bc)
 713 {
 714         acpi_unlazy_tlb(smp_processor_id());
 715
 716         /*
 717          * Must be done before busmaster disable as we might need to
 718          * access HPET !
 719          */
 720         if (timer_bc)
 721                 lapic_timer_state_broadcast(pr, cx, 1);
 722
 723         /*
 724          * disable bus master
 725          * bm_check implies we need ARB_DIS
 726          * bm_control implies whether we can do ARB_DIS
 727          *
 728          * That leaves a case where bm_check is set and bm_control is
 729          * not set. In that case we cannot do much, we enter C3
 730          * without doing anything.
 731          */
 732         if (pr->flags.bm_control) {
 733                 raw_spin_lock(&c3_lock);
 734                 c3_cpu_count++;
 735                 /* Disable bus master arbitration when all CPUs are in C3 */
 736                 if (c3_cpu_count == num_online_cpus())
 737                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 738                 raw_spin_unlock(&c3_lock);
 739         }
 740
 741         acpi_idle_do_entry(cx);
 742
 743         /* Re-enable bus master arbitration */
 744         if (pr->flags.bm_control) {
 745                 raw_spin_lock(&c3_lock);
 746                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 747                 c3_cpu_count--;
 748                 raw_spin_unlock(&c3_lock);
 749         }
 750
 751         if (timer_bc)
 752                 lapic_timer_state_broadcast(pr, cx, 0);
 753 }
 754
 755 static int acpi_idle_enter(struct cpuidle_device *dev,
 756                            struct cpuidle_driver *drv, int index)
 757 {
 758         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 759         struct acpi_processor *pr;
 760
 761         pr = __this_cpu_read(processors);
 762         if (unlikely(!pr))
 763                 return -EINVAL;
 764
 765         if (cx->type != ACPI_STATE_C1) {
 766                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 767                         index = ACPI_IDLE_STATE_START;
 768                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 769                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 770                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 771                                 acpi_idle_enter_bm(pr, cx, true);
 772                                 return index;
 773                         } else if (drv->safe_state_index >= 0) {
 774                                 index = drv->safe_state_index;
 775                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 776                         } else {
 777                                 acpi_safe_halt();
 778                                 return -EBUSY;
 779                         }
 780                 }
 781         }
 782
 783         lapic_timer_state_broadcast(pr, cx, 1);
 784
 785         if (cx->type == ACPI_STATE_C3)
 786                 ACPI_FLUSH_CPU_CACHE();
 787
 788         acpi_idle_do_entry(cx);
 789
 790         lapic_timer_state_broadcast(pr, cx, 0);
 791
 792         return index;
 793 }
 794
 795 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 796                                    struct cpuidle_driver *drv, int index)
 797 {
 798         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 799
 800         if (cx->type == ACPI_STATE_C3) {
 801                 struct acpi_processor *pr = __this_cpu_read(processors);
 802
 803                 if (unlikely(!pr))
 804                         return;
 805
 806                 if (pr->flags.bm_check) {
 807                         acpi_idle_enter_bm(pr, cx, false);
 808                         return;
 809                 } else {
 810                         ACPI_FLUSH_CPU_CACHE();
 811                 }
 812         }
 813         acpi_idle_do_entry(cx);
 814 }
 815
 816 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 817                                            struct cpuidle_device *dev)
 818 {
 819         int i, count = ACPI_IDLE_STATE_START;
 820         struct acpi_processor_cx *cx;
 821
 822         if (max_cstate == 0)
 823                 max_cstate = 1;
 824
 825         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 826                 cx = &pr->power.states[i];
 827
 828                 if (!cx->valid)
 829                         continue;
 830
 831                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 832
 833                 count++;
 834                 if (count == CPUIDLE_STATE_MAX)
 835                         break;
 836         }
 837
 838         if (!count)
 839                 return -EINVAL;
 840
 841         return 0;
 842 }
 843
 844 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 845 {
 846         int i, count;
 847         struct acpi_processor_cx *cx;
 848         struct cpuidle_state *state;
 849         struct cpuidle_driver *drv = &acpi_idle_driver;
 850
 851         if (max_cstate == 0)
 852                 max_cstate = 1;
 853
 854         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 855                 cpuidle_poll_state_init(drv);
 856                 count = 1;
 857         } else {
 858                 count = 0;
 859         }
 860
 861         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 862                 cx = &pr->power.states[i];
 863
 864                 if (!cx->valid)
 865                         continue;
 866
 867                 state = &drv->states[count];
 868                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 869                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 870                 state->exit_latency = cx->latency;
 871                 state->target_residency = cx->latency * latency_factor;
 872                 state->enter = acpi_idle_enter;
 873
 874                 state->flags = 0;
 875                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 876                         state->enter_dead = acpi_idle_play_dead;
 877                         drv->safe_state_index = count;
 878                 }
 879                 /*
 880                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 881                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 882                  * particularly interesting from the suspend-to-idle angle, so
 883                  * avoid C1 and the situations in which we may need to fall back
 884                  * to it altogether.
 885                  */
 886                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 887                         state->enter_s2idle = acpi_idle_enter_s2idle;
 888
 889                 count++;
 890                 if (count == CPUIDLE_STATE_MAX)
 891                         break;
 892         }
 893
 894         drv->state_count = count;
 895
 896         if (!count)
 897                 return -EINVAL;
 898
 899         return 0;
 900 }
 901
 902 static inline void acpi_processor_cstate_first_run_checks(void)
 903 {
 904         acpi_status status;
 905         static int first_run;
 906
 907         if (first_run)
 908                 return;
 909         dmi_check_system(processor_power_dmi_table);
 910         max_cstate = acpi_processor_cstate_check(max_cstate);
 911         if (max_cstate < ACPI_C_STATES_MAX)
 912                 pr_notice("ACPI: processor limited to max C-state %d\n",
 913                           max_cstate);
 914         first_run++;
 915
 916         if (acpi_gbl_FADT.cst_control && !nocst) {
 917                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 918                                             acpi_gbl_FADT.cst_control, 8);
 919                 if (ACPI_FAILURE(status))
 920                         ACPI_EXCEPTION((AE_INFO, status,
 921                                         "Notifying BIOS of _CST ability failed"));
 922         }
 923 }
 924 #else
 925
 926 static inline int disabled_by_idle_boot_param(void) { return 0; }
 927 static inline void acpi_processor_cstate_first_run_checks(void) { }
 928 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 929 {
 930         return -ENODEV;
 931 }
 932
 933 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 934                                            struct cpuidle_device *dev)
 935 {
 936         return -EINVAL;
 937 }
 938
 939 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 940 {
 941         return -EINVAL;
 942 }
 943
 944 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 945
 946 struct acpi_lpi_states_array {
 947         unsigned int size;
 948         unsigned int composite_states_size;
 949         struct acpi_lpi_state *entries;
 950         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 951 };
 952
 953 static int obj_get_integer(union acpi_object *obj, u32 *value)
 954 {
 955         if (obj->type != ACPI_TYPE_INTEGER)
 956                 return -EINVAL;
 957
 958         *value = obj->integer.value;
 959         return 0;
 960 }
 961
 962 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 963                                        struct acpi_lpi_states_array *info)
 964 {
 965         acpi_status status;
 966         int ret = 0;
 967         int pkg_count, state_idx = 1, loop;
 968         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 969         union acpi_object *lpi_data;
 970         struct acpi_lpi_state *lpi_state;
 971
 972         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 973         if (ACPI_FAILURE(status)) {
 974                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 975                 return -ENODEV;
 976         }
 977
 978         lpi_data = buffer.pointer;
 979
 980         /* There must be at least 4 elements = 3 elements + 1 package */
 981         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 982             lpi_data->package.count < 4) {
 983                 pr_debug("not enough elements in _LPI\n");
 984                 ret = -ENODATA;
 985                 goto end;
 986         }
 987
 988         pkg_count = lpi_data->package.elements[2].integer.value;
 989
 990         /* Validate number of power states. */
 991         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 992                 pr_debug("count given by _LPI is not valid\n");
 993                 ret = -ENODATA;
 994                 goto end;
 995         }
 996
 997         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 998         if (!lpi_state) {
 999                 ret = -ENOMEM;
1000                 goto end;
1001         }
1002
1003         info->size = pkg_count;
1004         info->entries = lpi_state;
1005
1006         /* LPI States start at index 3 */
1007         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1008                 union acpi_object *element, *pkg_elem, *obj;
1009
1010                 element = &lpi_data->package.elements[loop];
1011                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1012                         continue;
1013
1014                 pkg_elem = element->package.elements;
1015
1016                 obj = pkg_elem + 6;
1017                 if (obj->type == ACPI_TYPE_BUFFER) {
1018                         struct acpi_power_register *reg;
1019
1020                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1021                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1022                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1023                                 continue;
1024
1025                         lpi_state->address = reg->address;
1026                         lpi_state->entry_method =
1027                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1028                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1029                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1030                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1031                         lpi_state->address = obj->integer.value;
1032                 } else {
1033                         continue;
1034                 }
1035
1036                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1037
1038                 obj = pkg_elem + 9;
1039                 if (obj->type == ACPI_TYPE_STRING)
1040                         strlcpy(lpi_state->desc, obj->string.pointer,
1041                                 ACPI_CX_DESC_LEN);
1042
1043                 lpi_state->index = state_idx;
1044                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1045                         pr_debug("No min. residency found, assuming 10 us\n");
1046                         lpi_state->min_residency = 10;
1047                 }
1048
1049                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1050                         pr_debug("No wakeup residency found, assuming 10 us\n");
1051                         lpi_state->wake_latency = 10;
1052                 }
1053
1054                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1055                         lpi_state->flags = 0;
1056
1057                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1058                         lpi_state->arch_flags = 0;
1059
1060                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1061                         lpi_state->res_cnt_freq = 1;
1062
1063                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1064                         lpi_state->enable_parent_state = 0;
1065         }
1066
1067         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1068 end:
1069         kfree(buffer.pointer);
1070         return ret;
1071 }
1072
1073 /*
1074  * flat_state_cnt - the number of composite LPI states after the process of flattening
1075  */
1076 static int flat_state_cnt;
1077
1078 /**
1079  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1080  *
1081  * @local: local LPI state
1082  * @parent: parent LPI state
1083  * @result: composite LPI state
1084  */
1085 static bool combine_lpi_states(struct acpi_lpi_state *local,
1086                                struct acpi_lpi_state *parent,
1087                                struct acpi_lpi_state *result)
1088 {
1089         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1090                 if (!parent->address) /* 0 means autopromotable */
1091                         return false;
1092                 result->address = local->address + parent->address;
1093         } else {
1094                 result->address = parent->address;
1095         }
1096
1097         result->min_residency = max(local->min_residency, parent->min_residency);
1098         result->wake_latency = local->wake_latency + parent->wake_latency;
1099         result->enable_parent_state = parent->enable_parent_state;
1100         result->entry_method = local->entry_method;
1101
1102         result->flags = parent->flags;
1103         result->arch_flags = parent->arch_flags;
1104         result->index = parent->index;
1105
1106         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1107         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1108         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1109         return true;
1110 }
1111
1112 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1113
1114 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1115                                   struct acpi_lpi_state *t)
1116 {
1117         curr_level->composite_states[curr_level->composite_states_size++] = t;
1118 }
1119
1120 static int flatten_lpi_states(struct acpi_processor *pr,
1121                               struct acpi_lpi_states_array *curr_level,
1122                               struct acpi_lpi_states_array *prev_level)
1123 {
1124         int i, j, state_count = curr_level->size;
1125         struct acpi_lpi_state *p, *t = curr_level->entries;
1126
1127         curr_level->composite_states_size = 0;
1128         for (j = 0; j < state_count; j++, t++) {
1129                 struct acpi_lpi_state *flpi;
1130
1131                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1132                         continue;
1133
1134                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1135                         pr_warn("Limiting number of LPI states to max (%d)\n",
1136                                 ACPI_PROCESSOR_MAX_POWER);
1137                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1138                         break;
1139                 }
1140
1141                 flpi = &pr->power.lpi_states[flat_state_cnt];
1142
1143                 if (!prev_level) { /* leaf/processor node */
1144                         memcpy(flpi, t, sizeof(*t));
1145                         stash_composite_state(curr_level, flpi);
1146                         flat_state_cnt++;
1147                         continue;
1148                 }
1149
1150                 for (i = 0; i < prev_level->composite_states_size; i++) {
1151                         p = prev_level->composite_states[i];
1152                         if (t->index <= p->enable_parent_state &&
1153                             combine_lpi_states(p, t, flpi)) {
1154                                 stash_composite_state(curr_level, flpi);
1155                                 flat_state_cnt++;
1156                                 flpi++;
1157                         }
1158                 }
1159         }
1160
1161         kfree(curr_level->entries);
1162         return 0;
1163 }
1164
1165 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1166 {
1167         int ret, i;
1168         acpi_status status;
1169         acpi_handle handle = pr->handle, pr_ahandle;
1170         struct acpi_device *d = NULL;
1171         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1172
1173         if (!osc_pc_lpi_support_confirmed)
1174                 return -EOPNOTSUPP;
1175
1176         if (!acpi_has_method(handle, "_LPI"))
1177                 return -EINVAL;
1178
1179         flat_state_cnt = 0;
1180         prev = &info[0];
1181         curr = &info[1];
1182         handle = pr->handle;
1183         ret = acpi_processor_evaluate_lpi(handle, prev);
1184         if (ret)
1185                 return ret;
1186         flatten_lpi_states(pr, prev, NULL);
1187
1188         status = acpi_get_parent(handle, &pr_ahandle);
1189         while (ACPI_SUCCESS(status)) {
1190                 acpi_bus_get_device(pr_ahandle, &d);
1191                 handle = pr_ahandle;
1192
1193                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1194                         break;
1195
1196                 /* can be optional ? */
1197                 if (!acpi_has_method(handle, "_LPI"))
1198                         break;
1199
1200                 ret = acpi_processor_evaluate_lpi(handle, curr);
1201                 if (ret)
1202                         break;
1203
1204                 /* flatten all the LPI states in this level of hierarchy */
1205                 flatten_lpi_states(pr, curr, prev);
1206
1207                 tmp = prev, prev = curr, curr = tmp;
1208
1209                 status = acpi_get_parent(handle, &pr_ahandle);
1210         }
1211
1212         pr->power.count = flat_state_cnt;
1213         /* reset the index after flattening */
1214         for (i = 0; i < pr->power.count; i++)
1215                 pr->power.lpi_states[i].index = i;
1216
1217         /* Tell driver that _LPI is supported. */
1218         pr->flags.has_lpi = 1;
1219         pr->flags.power = 1;
1220
1221         return 0;
1222 }
1223
1224 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1225 {
1226         return -ENODEV;
1227 }
1228
1229 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1230 {
1231         return -ENODEV;
1232 }
1233
1234 /**
1235  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1236  * @dev: the target CPU
1237  * @drv: cpuidle driver containing cpuidle state info
1238  * @index: index of target state
1239  *
1240  * Return: 0 for success or negative value for error
1241  */
1242 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1243                                struct cpuidle_driver *drv, int index)
1244 {
1245         struct acpi_processor *pr;
1246         struct acpi_lpi_state *lpi;
1247
1248         pr = __this_cpu_read(processors);
1249
1250         if (unlikely(!pr))
1251                 return -EINVAL;
1252
1253         lpi = &pr->power.lpi_states[index];
1254         if (lpi->entry_method == ACPI_CSTATE_FFH)
1255                 return acpi_processor_ffh_lpi_enter(lpi);
1256
1257         return -EINVAL;
1258 }
1259
1260 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1261 {
1262         int i;
1263         struct acpi_lpi_state *lpi;
1264         struct cpuidle_state *state;
1265         struct cpuidle_driver *drv = &acpi_idle_driver;
1266
1267         if (!pr->flags.has_lpi)
1268                 return -EOPNOTSUPP;
1269
1270         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1271                 lpi = &pr->power.lpi_states[i];
1272
1273                 state = &drv->states[i];
1274                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1275                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1276                 state->exit_latency = lpi->wake_latency;
1277                 state->target_residency = lpi->min_residency;
1278                 if (lpi->arch_flags)
1279                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1280                 state->enter = acpi_idle_lpi_enter;
1281                 drv->safe_state_index = i;
1282         }
1283
1284         drv->state_count = i;
1285
1286         return 0;
1287 }
1288
1289 /**
1290  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1291  * global state data i.e. idle routines
1292  *
1293  * @pr: the ACPI processor
1294  */
1295 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1296 {
1297         int i;
1298         struct cpuidle_driver *drv = &acpi_idle_driver;
1299
1300         if (!pr->flags.power_setup_done || !pr->flags.power)
1301                 return -EINVAL;
1302
1303         drv->safe_state_index = -1;
1304         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1305                 drv->states[i].name[0] = '\0';
1306                 drv->states[i].desc[0] = '\0';
1307         }
1308
1309         if (pr->flags.has_lpi)
1310                 return acpi_processor_setup_lpi_states(pr);
1311
1312         return acpi_processor_setup_cstates(pr);
1313 }
1314
1315 /**
1316  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1317  * device i.e. per-cpu data
1318  *
1319  * @pr: the ACPI processor
1320  * @dev : the cpuidle device
1321  */
1322 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1323                                             struct cpuidle_device *dev)
1324 {
1325         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1326                 return -EINVAL;
1327
1328         dev->cpu = pr->id;
1329         if (pr->flags.has_lpi)
1330                 return acpi_processor_ffh_lpi_probe(pr->id);
1331
1332         return acpi_processor_setup_cpuidle_cx(pr, dev);
1333 }
1334
1335 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1336 {
1337         int ret;
1338
1339         ret = acpi_processor_get_lpi_info(pr);
1340         if (ret)
1341                 ret = acpi_processor_get_cstate_info(pr);
1342
1343         return ret;
1344 }
1345
1346 int acpi_processor_hotplug(struct acpi_processor *pr)
1347 {
1348         int ret = 0;
1349         struct cpuidle_device *dev;
1350
1351         if (disabled_by_idle_boot_param())
1352                 return 0;
1353
1354         if (!pr->flags.power_setup_done)
1355                 return -ENODEV;
1356
1357         dev = per_cpu(acpi_cpuidle_device, pr->id);
1358         cpuidle_pause_and_lock();
1359         cpuidle_disable_device(dev);
1360         ret = acpi_processor_get_power_info(pr);
1361         if (!ret && pr->flags.power) {
1362                 acpi_processor_setup_cpuidle_dev(pr, dev);
1363                 ret = cpuidle_enable_device(dev);
1364         }
1365         cpuidle_resume_and_unlock();
1366
1367         return ret;
1368 }
1369
1370 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1371 {
1372         int cpu;
1373         struct acpi_processor *_pr;
1374         struct cpuidle_device *dev;
1375
1376         if (disabled_by_idle_boot_param())
1377                 return 0;
1378
1379         if (!pr->flags.power_setup_done)
1380                 return -ENODEV;
1381
1382         /*
1383          * FIXME:  Design the ACPI notification to make it once per
1384          * system instead of once per-cpu.  This condition is a hack
1385          * to make the code that updates C-States be called once.
1386          */
1387
1388         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1389
1390                 /* Protect against cpu-hotplug */
1391                 get_online_cpus();
1392                 cpuidle_pause_and_lock();
1393
1394                 /* Disable all cpuidle devices */
1395                 for_each_online_cpu(cpu) {
1396                         _pr = per_cpu(processors, cpu);
1397                         if (!_pr || !_pr->flags.power_setup_done)
1398                                 continue;
1399                         dev = per_cpu(acpi_cpuidle_device, cpu);
1400                         cpuidle_disable_device(dev);
1401                 }
1402
1403                 /* Populate Updated C-state information */
1404                 acpi_processor_get_power_info(pr);
1405                 acpi_processor_setup_cpuidle_states(pr);
1406
1407                 /* Enable all cpuidle devices */
1408                 for_each_online_cpu(cpu) {
1409                         _pr = per_cpu(processors, cpu);
1410                         if (!_pr || !_pr->flags.power_setup_done)
1411                                 continue;
1412                         acpi_processor_get_power_info(_pr);
1413                         if (_pr->flags.power) {
1414                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1415                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1416                                 cpuidle_enable_device(dev);
1417                         }
1418                 }
1419                 cpuidle_resume_and_unlock();
1420                 put_online_cpus();
1421         }
1422
1423         return 0;
1424 }
1425
1426 static int acpi_processor_registered;
1427
1428 int acpi_processor_power_init(struct acpi_processor *pr)
1429 {
1430         int retval;
1431         struct cpuidle_device *dev;
1432
1433         if (disabled_by_idle_boot_param())
1434                 return 0;
1435
1436         acpi_processor_cstate_first_run_checks();
1437
1438         if (!acpi_processor_get_power_info(pr))
1439                 pr->flags.power_setup_done = 1;
1440
1441         /*
1442          * Install the idle handler if processor power management is supported.
1443          * Note that we use previously set idle handler will be used on
1444          * platforms that only support C1.
1445          */
1446         if (pr->flags.power) {
1447                 /* Register acpi_idle_driver if not already registered */
1448                 if (!acpi_processor_registered) {
1449                         acpi_processor_setup_cpuidle_states(pr);
1450                         retval = cpuidle_register_driver(&acpi_idle_driver);
1451                         if (retval)
1452                                 return retval;
1453                         pr_debug("%s registered with cpuidle\n",
1454                                  acpi_idle_driver.name);
1455                 }
1456
1457                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1458                 if (!dev)
1459                         return -ENOMEM;
1460                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1461
1462                 acpi_processor_setup_cpuidle_dev(pr, dev);
1463
1464                 /* Register per-cpu cpuidle_device. Cpuidle driver
1465                  * must already be registered before registering device
1466                  */
1467                 retval = cpuidle_register_device(dev);
1468                 if (retval) {
1469                         if (acpi_processor_registered == 0)
1470                                 cpuidle_unregister_driver(&acpi_idle_driver);
1471                         return retval;
1472                 }
1473                 acpi_processor_registered++;
1474         }
1475         return 0;
1476 }
1477
1478 int acpi_processor_power_exit(struct acpi_processor *pr)
1479 {
1480         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1481
1482         if (disabled_by_idle_boot_param())
1483                 return 0;
1484
1485         if (pr->flags.power) {
1486                 cpuidle_unregister_device(dev);
1487                 acpi_processor_registered--;
1488                 if (acpi_processor_registered == 0)
1489                         cpuidle_unregister_driver(&acpi_idle_driver);
1490         }
1491
1492         pr->flags.power_setup_done = 0;
1493         return 0;
1494 }