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/sort.h>
  33 #include <linux/tick.h>
  34 #include <linux/cpuidle.h>
  35 #include <linux/cpu.h>
  36 #include <acpi/processor.h>
  37
  38 /*
  39  * Include the apic definitions for x86 to have the APIC timer related defines
  40  * available also for UP (on SMP it gets magically included via linux/smp.h).
  41  * asm/acpi.h is not an option, as it would require more include magic. Also
  42  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  43  */
  44 #ifdef CONFIG_X86
  45 #include <asm/apic.h>
  46 #endif
  47
  48 #define ACPI_PROCESSOR_CLASS            "processor"
  49 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  50 ACPI_MODULE_NAME("processor_idle");
  51
  52 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  53
  54 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  55 module_param(max_cstate, uint, 0000);
  56 static unsigned int nocst __read_mostly;
  57 module_param(nocst, uint, 0000);
  58 static int bm_check_disable __read_mostly;
  59 module_param(bm_check_disable, uint, 0000);
  60
  61 static unsigned int latency_factor __read_mostly = 2;
  62 module_param(latency_factor, uint, 0644);
  63
  64 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  65
  66 struct cpuidle_driver acpi_idle_driver = {
  67         .name =         "acpi_idle",
  68         .owner =        THIS_MODULE,
  69 };
  70
  71 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  72 static
  73 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  74
  75 static int disabled_by_idle_boot_param(void)
  76 {
  77         return boot_option_idle_override == IDLE_POLL ||
  78                 boot_option_idle_override == IDLE_HALT;
  79 }
  80
  81 /*
  82  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  83  * For now disable this. Probably a bug somewhere else.
  84  *
  85  * To skip this limit, boot/load with a large max_cstate limit.
  86  */
  87 static int set_max_cstate(const struct dmi_system_id *id)
  88 {
  89         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  90                 return 0;
  91
  92         pr_notice("%s detected - limiting to C%ld max_cstate."
  93                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  94                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  95
  96         max_cstate = (long)id->driver_data;
  97
  98         return 0;
  99 }
 100
 101 static const struct dmi_system_id processor_power_dmi_table[] = {
 102         { set_max_cstate, "Clevo 5600D", {
 103           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 104           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 105          (void *)2},
 106         { set_max_cstate, "Pavilion zv5000", {
 107           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 108           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 109          (void *)1},
 110         { set_max_cstate, "Asus L8400B", {
 111           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 112           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 113          (void *)1},
 114         {},
 115 };
 116
 117
 118 /*
 119  * Callers should disable interrupts before the call and enable
 120  * interrupts after return.
 121  */
 122 static void __cpuidle acpi_safe_halt(void)
 123 {
 124         if (!tif_need_resched()) {
 125                 safe_halt();
 126                 local_irq_disable();
 127         }
 128 }
 129
 130 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 131
 132 /*
 133  * Some BIOS implementations switch to C3 in the published C2 state.
 134  * This seems to be a common problem on AMD boxen, but other vendors
 135  * are affected too. We pick the most conservative approach: we assume
 136  * that the local APIC stops in both C2 and C3.
 137  */
 138 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 139                                    struct acpi_processor_cx *cx)
 140 {
 141         struct acpi_processor_power *pwr = &pr->power;
 142         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 143
 144         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 145                 return;
 146
 147         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 148                 type = ACPI_STATE_C1;
 149
 150         /*
 151          * Check, if one of the previous states already marked the lapic
 152          * unstable
 153          */
 154         if (pwr->timer_broadcast_on_state < state)
 155                 return;
 156
 157         if (cx->type >= type)
 158                 pr->power.timer_broadcast_on_state = state;
 159 }
 160
 161 static void __lapic_timer_propagate_broadcast(void *arg)
 162 {
 163         struct acpi_processor *pr = (struct acpi_processor *) arg;
 164
 165         if (pr->power.timer_broadcast_on_state < INT_MAX)
 166                 tick_broadcast_enable();
 167         else
 168                 tick_broadcast_disable();
 169 }
 170
 171 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 172 {
 173         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 174                                  (void *)pr, 1);
 175 }
 176
 177 /* Power(C) State timer broadcast control */
 178 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 179                                        struct acpi_processor_cx *cx,
 180                                        int broadcast)
 181 {
 182         int state = cx - pr->power.states;
 183
 184         if (state >= pr->power.timer_broadcast_on_state) {
 185                 if (broadcast)
 186                         tick_broadcast_enter();
 187                 else
 188                         tick_broadcast_exit();
 189         }
 190 }
 191
 192 #else
 193
 194 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 195                                    struct acpi_processor_cx *cstate) { }
 196 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 197 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 198                                        struct acpi_processor_cx *cx,
 199                                        int broadcast)
 200 {
 201 }
 202
 203 #endif
 204
 205 #if defined(CONFIG_X86)
 206 static void tsc_check_state(int state)
 207 {
 208         switch (boot_cpu_data.x86_vendor) {
 209         case X86_VENDOR_AMD:
 210         case X86_VENDOR_INTEL:
 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_cst_latency_cmp(const void *a, const void *b)
 545 {
 546         const struct acpi_processor_cx *x = a, *y = b;
 547
 548         if (!(x->valid && y->valid))
 549                 return 0;
 550         if (x->latency > y->latency)
 551                 return 1;
 552         if (x->latency < y->latency)
 553                 return -1;
 554         return 0;
 555 }
 556 static void acpi_cst_latency_swap(void *a, void *b, int n)
 557 {
 558         struct acpi_processor_cx *x = a, *y = b;
 559         u32 tmp;
 560
 561         if (!(x->valid && y->valid))
 562                 return;
 563         tmp = x->latency;
 564         x->latency = y->latency;
 565         y->latency = tmp;
 566 }
 567
 568 static int acpi_processor_power_verify(struct acpi_processor *pr)
 569 {
 570         unsigned int i;
 571         unsigned int working = 0;
 572         unsigned int last_latency = 0;
 573         unsigned int last_type = 0;
 574         bool buggy_latency = false;
 575
 576         pr->power.timer_broadcast_on_state = INT_MAX;
 577
 578         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 579                 struct acpi_processor_cx *cx = &pr->power.states[i];
 580
 581                 switch (cx->type) {
 582                 case ACPI_STATE_C1:
 583                         cx->valid = 1;
 584                         break;
 585
 586                 case ACPI_STATE_C2:
 587                         if (!cx->address)
 588                                 break;
 589                         cx->valid = 1;
 590                         break;
 591
 592                 case ACPI_STATE_C3:
 593                         acpi_processor_power_verify_c3(pr, cx);
 594                         break;
 595                 }
 596                 if (!cx->valid)
 597                         continue;
 598                 if (cx->type >= last_type && cx->latency < last_latency)
 599                         buggy_latency = true;
 600                 last_latency = cx->latency;
 601                 last_type = cx->type;
 602
 603                 lapic_timer_check_state(i, pr, cx);
 604                 tsc_check_state(cx->type);
 605                 working++;
 606         }
 607
 608         if (buggy_latency) {
 609                 pr_notice("FW issue: working around C-state latencies out of order\n");
 610                 sort(&pr->power.states[1], max_cstate,
 611                      sizeof(struct acpi_processor_cx),
 612                      acpi_cst_latency_cmp,
 613                      acpi_cst_latency_swap);
 614         }
 615
 616         lapic_timer_propagate_broadcast(pr);
 617
 618         return (working);
 619 }
 620
 621 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 622 {
 623         unsigned int i;
 624         int result;
 625
 626
 627         /* NOTE: the idle thread may not be running while calling
 628          * this function */
 629
 630         /* Zero initialize all the C-states info. */
 631         memset(pr->power.states, 0, sizeof(pr->power.states));
 632
 633         result = acpi_processor_get_power_info_cst(pr);
 634         if (result == -ENODEV)
 635                 result = acpi_processor_get_power_info_fadt(pr);
 636
 637         if (result)
 638                 return result;
 639
 640         acpi_processor_get_power_info_default(pr);
 641
 642         pr->power.count = acpi_processor_power_verify(pr);
 643
 644         /*
 645          * if one state of type C2 or C3 is available, mark this
 646          * CPU as being "idle manageable"
 647          */
 648         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 649                 if (pr->power.states[i].valid) {
 650                         pr->power.count = i;
 651                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 652                                 pr->flags.power = 1;
 653                 }
 654         }
 655
 656         return 0;
 657 }
 658
 659 /**
 660  * acpi_idle_bm_check - checks if bus master activity was detected
 661  */
 662 static int acpi_idle_bm_check(void)
 663 {
 664         u32 bm_status = 0;
 665
 666         if (bm_check_disable)
 667                 return 0;
 668
 669         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 670         if (bm_status)
 671                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 672         /*
 673          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 674          * the true state of bus mastering activity; forcing us to
 675          * manually check the BMIDEA bit of each IDE channel.
 676          */
 677         else if (errata.piix4.bmisx) {
 678                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 679                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 680                         bm_status = 1;
 681         }
 682         return bm_status;
 683 }
 684
 685 /**
 686  * acpi_idle_do_entry - enter idle state using the appropriate method
 687  * @cx: cstate data
 688  *
 689  * Caller disables interrupt before call and enables interrupt after return.
 690  */
 691 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 692 {
 693         if (cx->entry_method == ACPI_CSTATE_FFH) {
 694                 /* Call into architectural FFH based C-state */
 695                 acpi_processor_ffh_cstate_enter(cx);
 696         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 697                 acpi_safe_halt();
 698         } else {
 699                 /* IO port based C-state */
 700                 inb(cx->address);
 701                 /* Dummy wait op - must do something useless after P_LVL2 read
 702                    because chipsets cannot guarantee that STPCLK# signal
 703                    gets asserted in time to freeze execution properly. */
 704                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 705         }
 706 }
 707
 708 /**
 709  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 710  * @dev: the target CPU
 711  * @index: the index of suggested state
 712  */
 713 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 714 {
 715         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 716
 717         ACPI_FLUSH_CPU_CACHE();
 718
 719         while (1) {
 720
 721                 if (cx->entry_method == ACPI_CSTATE_HALT)
 722                         safe_halt();
 723                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 724                         inb(cx->address);
 725                         /* See comment in acpi_idle_do_entry() */
 726                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 727                 } else
 728                         return -ENODEV;
 729         }
 730
 731         /* Never reached */
 732         return 0;
 733 }
 734
 735 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 736 {
 737         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 738                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 739 }
 740
 741 static int c3_cpu_count;
 742 static DEFINE_RAW_SPINLOCK(c3_lock);
 743
 744 /**
 745  * acpi_idle_enter_bm - enters C3 with proper BM handling
 746  * @pr: Target processor
 747  * @cx: Target state context
 748  * @timer_bc: Whether or not to change timer mode to broadcast
 749  */
 750 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 751                                struct acpi_processor_cx *cx, bool timer_bc)
 752 {
 753         acpi_unlazy_tlb(smp_processor_id());
 754
 755         /*
 756          * Must be done before busmaster disable as we might need to
 757          * access HPET !
 758          */
 759         if (timer_bc)
 760                 lapic_timer_state_broadcast(pr, cx, 1);
 761
 762         /*
 763          * disable bus master
 764          * bm_check implies we need ARB_DIS
 765          * bm_control implies whether we can do ARB_DIS
 766          *
 767          * That leaves a case where bm_check is set and bm_control is
 768          * not set. In that case we cannot do much, we enter C3
 769          * without doing anything.
 770          */
 771         if (pr->flags.bm_control) {
 772                 raw_spin_lock(&c3_lock);
 773                 c3_cpu_count++;
 774                 /* Disable bus master arbitration when all CPUs are in C3 */
 775                 if (c3_cpu_count == num_online_cpus())
 776                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 777                 raw_spin_unlock(&c3_lock);
 778         }
 779
 780         acpi_idle_do_entry(cx);
 781
 782         /* Re-enable bus master arbitration */
 783         if (pr->flags.bm_control) {
 784                 raw_spin_lock(&c3_lock);
 785                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 786                 c3_cpu_count--;
 787                 raw_spin_unlock(&c3_lock);
 788         }
 789
 790         if (timer_bc)
 791                 lapic_timer_state_broadcast(pr, cx, 0);
 792 }
 793
 794 static int acpi_idle_enter(struct cpuidle_device *dev,
 795                            struct cpuidle_driver *drv, int index)
 796 {
 797         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 798         struct acpi_processor *pr;
 799
 800         pr = __this_cpu_read(processors);
 801         if (unlikely(!pr))
 802                 return -EINVAL;
 803
 804         if (cx->type != ACPI_STATE_C1) {
 805                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 806                         index = ACPI_IDLE_STATE_START;
 807                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 808                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 809                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 810                                 acpi_idle_enter_bm(pr, cx, true);
 811                                 return index;
 812                         } else if (drv->safe_state_index >= 0) {
 813                                 index = drv->safe_state_index;
 814                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 815                         } else {
 816                                 acpi_safe_halt();
 817                                 return -EBUSY;
 818                         }
 819                 }
 820         }
 821
 822         lapic_timer_state_broadcast(pr, cx, 1);
 823
 824         if (cx->type == ACPI_STATE_C3)
 825                 ACPI_FLUSH_CPU_CACHE();
 826
 827         acpi_idle_do_entry(cx);
 828
 829         lapic_timer_state_broadcast(pr, cx, 0);
 830
 831         return index;
 832 }
 833
 834 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 835                                    struct cpuidle_driver *drv, int index)
 836 {
 837         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 838
 839         if (cx->type == ACPI_STATE_C3) {
 840                 struct acpi_processor *pr = __this_cpu_read(processors);
 841
 842                 if (unlikely(!pr))
 843                         return;
 844
 845                 if (pr->flags.bm_check) {
 846                         acpi_idle_enter_bm(pr, cx, false);
 847                         return;
 848                 } else {
 849                         ACPI_FLUSH_CPU_CACHE();
 850                 }
 851         }
 852         acpi_idle_do_entry(cx);
 853 }
 854
 855 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 856                                            struct cpuidle_device *dev)
 857 {
 858         int i, count = ACPI_IDLE_STATE_START;
 859         struct acpi_processor_cx *cx;
 860
 861         if (max_cstate == 0)
 862                 max_cstate = 1;
 863
 864         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 865                 cx = &pr->power.states[i];
 866
 867                 if (!cx->valid)
 868                         continue;
 869
 870                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 871
 872                 count++;
 873                 if (count == CPUIDLE_STATE_MAX)
 874                         break;
 875         }
 876
 877         if (!count)
 878                 return -EINVAL;
 879
 880         return 0;
 881 }
 882
 883 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 884 {
 885         int i, count;
 886         struct acpi_processor_cx *cx;
 887         struct cpuidle_state *state;
 888         struct cpuidle_driver *drv = &acpi_idle_driver;
 889
 890         if (max_cstate == 0)
 891                 max_cstate = 1;
 892
 893         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 894                 cpuidle_poll_state_init(drv);
 895                 count = 1;
 896         } else {
 897                 count = 0;
 898         }
 899
 900         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 901                 cx = &pr->power.states[i];
 902
 903                 if (!cx->valid)
 904                         continue;
 905
 906                 state = &drv->states[count];
 907                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 908                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 909                 state->exit_latency = cx->latency;
 910                 state->target_residency = cx->latency * latency_factor;
 911                 state->enter = acpi_idle_enter;
 912
 913                 state->flags = 0;
 914                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 915                         state->enter_dead = acpi_idle_play_dead;
 916                         drv->safe_state_index = count;
 917                 }
 918                 /*
 919                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 920                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 921                  * particularly interesting from the suspend-to-idle angle, so
 922                  * avoid C1 and the situations in which we may need to fall back
 923                  * to it altogether.
 924                  */
 925                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 926                         state->enter_s2idle = acpi_idle_enter_s2idle;
 927
 928                 count++;
 929                 if (count == CPUIDLE_STATE_MAX)
 930                         break;
 931         }
 932
 933         drv->state_count = count;
 934
 935         if (!count)
 936                 return -EINVAL;
 937
 938         return 0;
 939 }
 940
 941 static inline void acpi_processor_cstate_first_run_checks(void)
 942 {
 943         acpi_status status;
 944         static int first_run;
 945
 946         if (first_run)
 947                 return;
 948         dmi_check_system(processor_power_dmi_table);
 949         max_cstate = acpi_processor_cstate_check(max_cstate);
 950         if (max_cstate < ACPI_C_STATES_MAX)
 951                 pr_notice("ACPI: processor limited to max C-state %d\n",
 952                           max_cstate);
 953         first_run++;
 954
 955         if (acpi_gbl_FADT.cst_control && !nocst) {
 956                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 957                                             acpi_gbl_FADT.cst_control, 8);
 958                 if (ACPI_FAILURE(status))
 959                         ACPI_EXCEPTION((AE_INFO, status,
 960                                         "Notifying BIOS of _CST ability failed"));
 961         }
 962 }
 963 #else
 964
 965 static inline int disabled_by_idle_boot_param(void) { return 0; }
 966 static inline void acpi_processor_cstate_first_run_checks(void) { }
 967 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 968 {
 969         return -ENODEV;
 970 }
 971
 972 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 973                                            struct cpuidle_device *dev)
 974 {
 975         return -EINVAL;
 976 }
 977
 978 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 979 {
 980         return -EINVAL;
 981 }
 982
 983 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 984
 985 struct acpi_lpi_states_array {
 986         unsigned int size;
 987         unsigned int composite_states_size;
 988         struct acpi_lpi_state *entries;
 989         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 990 };
 991
 992 static int obj_get_integer(union acpi_object *obj, u32 *value)
 993 {
 994         if (obj->type != ACPI_TYPE_INTEGER)
 995                 return -EINVAL;
 996
 997         *value = obj->integer.value;
 998         return 0;
 999 }
1000
1001 static int acpi_processor_evaluate_lpi(acpi_handle handle,
1002                                        struct acpi_lpi_states_array *info)
1003 {
1004         acpi_status status;
1005         int ret = 0;
1006         int pkg_count, state_idx = 1, loop;
1007         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1008         union acpi_object *lpi_data;
1009         struct acpi_lpi_state *lpi_state;
1010
1011         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
1012         if (ACPI_FAILURE(status)) {
1013                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
1014                 return -ENODEV;
1015         }
1016
1017         lpi_data = buffer.pointer;
1018
1019         /* There must be at least 4 elements = 3 elements + 1 package */
1020         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
1021             lpi_data->package.count < 4) {
1022                 pr_debug("not enough elements in _LPI\n");
1023                 ret = -ENODATA;
1024                 goto end;
1025         }
1026
1027         pkg_count = lpi_data->package.elements[2].integer.value;
1028
1029         /* Validate number of power states. */
1030         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
1031                 pr_debug("count given by _LPI is not valid\n");
1032                 ret = -ENODATA;
1033                 goto end;
1034         }
1035
1036         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1037         if (!lpi_state) {
1038                 ret = -ENOMEM;
1039                 goto end;
1040         }
1041
1042         info->size = pkg_count;
1043         info->entries = lpi_state;
1044
1045         /* LPI States start at index 3 */
1046         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1047                 union acpi_object *element, *pkg_elem, *obj;
1048
1049                 element = &lpi_data->package.elements[loop];
1050                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1051                         continue;
1052
1053                 pkg_elem = element->package.elements;
1054
1055                 obj = pkg_elem + 6;
1056                 if (obj->type == ACPI_TYPE_BUFFER) {
1057                         struct acpi_power_register *reg;
1058
1059                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1060                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1061                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1062                                 continue;
1063
1064                         lpi_state->address = reg->address;
1065                         lpi_state->entry_method =
1066                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1067                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1068                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1069                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1070                         lpi_state->address = obj->integer.value;
1071                 } else {
1072                         continue;
1073                 }
1074
1075                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1076
1077                 obj = pkg_elem + 9;
1078                 if (obj->type == ACPI_TYPE_STRING)
1079                         strlcpy(lpi_state->desc, obj->string.pointer,
1080                                 ACPI_CX_DESC_LEN);
1081
1082                 lpi_state->index = state_idx;
1083                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1084                         pr_debug("No min. residency found, assuming 10 us\n");
1085                         lpi_state->min_residency = 10;
1086                 }
1087
1088                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1089                         pr_debug("No wakeup residency found, assuming 10 us\n");
1090                         lpi_state->wake_latency = 10;
1091                 }
1092
1093                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1094                         lpi_state->flags = 0;
1095
1096                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1097                         lpi_state->arch_flags = 0;
1098
1099                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1100                         lpi_state->res_cnt_freq = 1;
1101
1102                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1103                         lpi_state->enable_parent_state = 0;
1104         }
1105
1106         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1107 end:
1108         kfree(buffer.pointer);
1109         return ret;
1110 }
1111
1112 /*
1113  * flat_state_cnt - the number of composite LPI states after the process of flattening
1114  */
1115 static int flat_state_cnt;
1116
1117 /**
1118  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1119  *
1120  * @local: local LPI state
1121  * @parent: parent LPI state
1122  * @result: composite LPI state
1123  */
1124 static bool combine_lpi_states(struct acpi_lpi_state *local,
1125                                struct acpi_lpi_state *parent,
1126                                struct acpi_lpi_state *result)
1127 {
1128         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1129                 if (!parent->address) /* 0 means autopromotable */
1130                         return false;
1131                 result->address = local->address + parent->address;
1132         } else {
1133                 result->address = parent->address;
1134         }
1135
1136         result->min_residency = max(local->min_residency, parent->min_residency);
1137         result->wake_latency = local->wake_latency + parent->wake_latency;
1138         result->enable_parent_state = parent->enable_parent_state;
1139         result->entry_method = local->entry_method;
1140
1141         result->flags = parent->flags;
1142         result->arch_flags = parent->arch_flags;
1143         result->index = parent->index;
1144
1145         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1146         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1147         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1148         return true;
1149 }
1150
1151 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1152
1153 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1154                                   struct acpi_lpi_state *t)
1155 {
1156         curr_level->composite_states[curr_level->composite_states_size++] = t;
1157 }
1158
1159 static int flatten_lpi_states(struct acpi_processor *pr,
1160                               struct acpi_lpi_states_array *curr_level,
1161                               struct acpi_lpi_states_array *prev_level)
1162 {
1163         int i, j, state_count = curr_level->size;
1164         struct acpi_lpi_state *p, *t = curr_level->entries;
1165
1166         curr_level->composite_states_size = 0;
1167         for (j = 0; j < state_count; j++, t++) {
1168                 struct acpi_lpi_state *flpi;
1169
1170                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1171                         continue;
1172
1173                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1174                         pr_warn("Limiting number of LPI states to max (%d)\n",
1175                                 ACPI_PROCESSOR_MAX_POWER);
1176                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1177                         break;
1178                 }
1179
1180                 flpi = &pr->power.lpi_states[flat_state_cnt];
1181
1182                 if (!prev_level) { /* leaf/processor node */
1183                         memcpy(flpi, t, sizeof(*t));
1184                         stash_composite_state(curr_level, flpi);
1185                         flat_state_cnt++;
1186                         continue;
1187                 }
1188
1189                 for (i = 0; i < prev_level->composite_states_size; i++) {
1190                         p = prev_level->composite_states[i];
1191                         if (t->index <= p->enable_parent_state &&
1192                             combine_lpi_states(p, t, flpi)) {
1193                                 stash_composite_state(curr_level, flpi);
1194                                 flat_state_cnt++;
1195                                 flpi++;
1196                         }
1197                 }
1198         }
1199
1200         kfree(curr_level->entries);
1201         return 0;
1202 }
1203
1204 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1205 {
1206         int ret, i;
1207         acpi_status status;
1208         acpi_handle handle = pr->handle, pr_ahandle;
1209         struct acpi_device *d = NULL;
1210         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1211
1212         if (!osc_pc_lpi_support_confirmed)
1213                 return -EOPNOTSUPP;
1214
1215         if (!acpi_has_method(handle, "_LPI"))
1216                 return -EINVAL;
1217
1218         flat_state_cnt = 0;
1219         prev = &info[0];
1220         curr = &info[1];
1221         handle = pr->handle;
1222         ret = acpi_processor_evaluate_lpi(handle, prev);
1223         if (ret)
1224                 return ret;
1225         flatten_lpi_states(pr, prev, NULL);
1226
1227         status = acpi_get_parent(handle, &pr_ahandle);
1228         while (ACPI_SUCCESS(status)) {
1229                 acpi_bus_get_device(pr_ahandle, &d);
1230                 handle = pr_ahandle;
1231
1232                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1233                         break;
1234
1235                 /* can be optional ? */
1236                 if (!acpi_has_method(handle, "_LPI"))
1237                         break;
1238
1239                 ret = acpi_processor_evaluate_lpi(handle, curr);
1240                 if (ret)
1241                         break;
1242
1243                 /* flatten all the LPI states in this level of hierarchy */
1244                 flatten_lpi_states(pr, curr, prev);
1245
1246                 tmp = prev, prev = curr, curr = tmp;
1247
1248                 status = acpi_get_parent(handle, &pr_ahandle);
1249         }
1250
1251         pr->power.count = flat_state_cnt;
1252         /* reset the index after flattening */
1253         for (i = 0; i < pr->power.count; i++)
1254                 pr->power.lpi_states[i].index = i;
1255
1256         /* Tell driver that _LPI is supported. */
1257         pr->flags.has_lpi = 1;
1258         pr->flags.power = 1;
1259
1260         return 0;
1261 }
1262
1263 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1264 {
1265         return -ENODEV;
1266 }
1267
1268 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1269 {
1270         return -ENODEV;
1271 }
1272
1273 /**
1274  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1275  * @dev: the target CPU
1276  * @drv: cpuidle driver containing cpuidle state info
1277  * @index: index of target state
1278  *
1279  * Return: 0 for success or negative value for error
1280  */
1281 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1282                                struct cpuidle_driver *drv, int index)
1283 {
1284         struct acpi_processor *pr;
1285         struct acpi_lpi_state *lpi;
1286
1287         pr = __this_cpu_read(processors);
1288
1289         if (unlikely(!pr))
1290                 return -EINVAL;
1291
1292         lpi = &pr->power.lpi_states[index];
1293         if (lpi->entry_method == ACPI_CSTATE_FFH)
1294                 return acpi_processor_ffh_lpi_enter(lpi);
1295
1296         return -EINVAL;
1297 }
1298
1299 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1300 {
1301         int i;
1302         struct acpi_lpi_state *lpi;
1303         struct cpuidle_state *state;
1304         struct cpuidle_driver *drv = &acpi_idle_driver;
1305
1306         if (!pr->flags.has_lpi)
1307                 return -EOPNOTSUPP;
1308
1309         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1310                 lpi = &pr->power.lpi_states[i];
1311
1312                 state = &drv->states[i];
1313                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1314                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1315                 state->exit_latency = lpi->wake_latency;
1316                 state->target_residency = lpi->min_residency;
1317                 if (lpi->arch_flags)
1318                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1319                 state->enter = acpi_idle_lpi_enter;
1320                 drv->safe_state_index = i;
1321         }
1322
1323         drv->state_count = i;
1324
1325         return 0;
1326 }
1327
1328 /**
1329  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1330  * global state data i.e. idle routines
1331  *
1332  * @pr: the ACPI processor
1333  */
1334 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1335 {
1336         int i;
1337         struct cpuidle_driver *drv = &acpi_idle_driver;
1338
1339         if (!pr->flags.power_setup_done || !pr->flags.power)
1340                 return -EINVAL;
1341
1342         drv->safe_state_index = -1;
1343         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1344                 drv->states[i].name[0] = '\0';
1345                 drv->states[i].desc[0] = '\0';
1346         }
1347
1348         if (pr->flags.has_lpi)
1349                 return acpi_processor_setup_lpi_states(pr);
1350
1351         return acpi_processor_setup_cstates(pr);
1352 }
1353
1354 /**
1355  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1356  * device i.e. per-cpu data
1357  *
1358  * @pr: the ACPI processor
1359  * @dev : the cpuidle device
1360  */
1361 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1362                                             struct cpuidle_device *dev)
1363 {
1364         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1365                 return -EINVAL;
1366
1367         dev->cpu = pr->id;
1368         if (pr->flags.has_lpi)
1369                 return acpi_processor_ffh_lpi_probe(pr->id);
1370
1371         return acpi_processor_setup_cpuidle_cx(pr, dev);
1372 }
1373
1374 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1375 {
1376         int ret;
1377
1378         ret = acpi_processor_get_lpi_info(pr);
1379         if (ret)
1380                 ret = acpi_processor_get_cstate_info(pr);
1381
1382         return ret;
1383 }
1384
1385 int acpi_processor_hotplug(struct acpi_processor *pr)
1386 {
1387         int ret = 0;
1388         struct cpuidle_device *dev;
1389
1390         if (disabled_by_idle_boot_param())
1391                 return 0;
1392
1393         if (!pr->flags.power_setup_done)
1394                 return -ENODEV;
1395
1396         dev = per_cpu(acpi_cpuidle_device, pr->id);
1397         cpuidle_pause_and_lock();
1398         cpuidle_disable_device(dev);
1399         ret = acpi_processor_get_power_info(pr);
1400         if (!ret && pr->flags.power) {
1401                 acpi_processor_setup_cpuidle_dev(pr, dev);
1402                 ret = cpuidle_enable_device(dev);
1403         }
1404         cpuidle_resume_and_unlock();
1405
1406         return ret;
1407 }
1408
1409 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1410 {
1411         int cpu;
1412         struct acpi_processor *_pr;
1413         struct cpuidle_device *dev;
1414
1415         if (disabled_by_idle_boot_param())
1416                 return 0;
1417
1418         if (!pr->flags.power_setup_done)
1419                 return -ENODEV;
1420
1421         /*
1422          * FIXME:  Design the ACPI notification to make it once per
1423          * system instead of once per-cpu.  This condition is a hack
1424          * to make the code that updates C-States be called once.
1425          */
1426
1427         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1428
1429                 /* Protect against cpu-hotplug */
1430                 get_online_cpus();
1431                 cpuidle_pause_and_lock();
1432
1433                 /* Disable all cpuidle devices */
1434                 for_each_online_cpu(cpu) {
1435                         _pr = per_cpu(processors, cpu);
1436                         if (!_pr || !_pr->flags.power_setup_done)
1437                                 continue;
1438                         dev = per_cpu(acpi_cpuidle_device, cpu);
1439                         cpuidle_disable_device(dev);
1440                 }
1441
1442                 /* Populate Updated C-state information */
1443                 acpi_processor_get_power_info(pr);
1444                 acpi_processor_setup_cpuidle_states(pr);
1445
1446                 /* Enable all cpuidle devices */
1447                 for_each_online_cpu(cpu) {
1448                         _pr = per_cpu(processors, cpu);
1449                         if (!_pr || !_pr->flags.power_setup_done)
1450                                 continue;
1451                         acpi_processor_get_power_info(_pr);
1452                         if (_pr->flags.power) {
1453                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1454                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1455                                 cpuidle_enable_device(dev);
1456                         }
1457                 }
1458                 cpuidle_resume_and_unlock();
1459                 put_online_cpus();
1460         }
1461
1462         return 0;
1463 }
1464
1465 static int acpi_processor_registered;
1466
1467 int acpi_processor_power_init(struct acpi_processor *pr)
1468 {
1469         int retval;
1470         struct cpuidle_device *dev;
1471
1472         if (disabled_by_idle_boot_param())
1473                 return 0;
1474
1475         acpi_processor_cstate_first_run_checks();
1476
1477         if (!acpi_processor_get_power_info(pr))
1478                 pr->flags.power_setup_done = 1;
1479
1480         /*
1481          * Install the idle handler if processor power management is supported.
1482          * Note that we use previously set idle handler will be used on
1483          * platforms that only support C1.
1484          */
1485         if (pr->flags.power) {
1486                 /* Register acpi_idle_driver if not already registered */
1487                 if (!acpi_processor_registered) {
1488                         acpi_processor_setup_cpuidle_states(pr);
1489                         retval = cpuidle_register_driver(&acpi_idle_driver);
1490                         if (retval)
1491                                 return retval;
1492                         pr_debug("%s registered with cpuidle\n",
1493                                  acpi_idle_driver.name);
1494                 }
1495
1496                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1497                 if (!dev)
1498                         return -ENOMEM;
1499                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1500
1501                 acpi_processor_setup_cpuidle_dev(pr, dev);
1502
1503                 /* Register per-cpu cpuidle_device. Cpuidle driver
1504                  * must already be registered before registering device
1505                  */
1506                 retval = cpuidle_register_device(dev);
1507                 if (retval) {
1508                         if (acpi_processor_registered == 0)
1509                                 cpuidle_unregister_driver(&acpi_idle_driver);
1510                         return retval;
1511                 }
1512                 acpi_processor_registered++;
1513         }
1514         return 0;
1515 }
1516
1517 int acpi_processor_power_exit(struct acpi_processor *pr)
1518 {
1519         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1520
1521         if (disabled_by_idle_boot_param())
1522                 return 0;
1523
1524         if (pr->flags.power) {
1525                 cpuidle_unregister_device(dev);
1526                 acpi_processor_registered--;
1527                 if (acpi_processor_registered == 0)
1528                         cpuidle_unregister_driver(&acpi_idle_driver);
1529         }
1530
1531         pr->flags.power_setup_done = 0;
1532         return 0;
1533 }