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_HYGON:
 209         case X86_VENDOR_AMD:
 210         case X86_VENDOR_INTEL:
 211         case X86_VENDOR_CENTAUR:
 212                 /*
 213                  * AMD Fam10h TSC will tick in all
 214                  * C/P/S0/S1 states when this bit is set.
 215                  */
 216                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 217                         return;
 218
 219                 /*FALL THROUGH*/
 220         default:
 221                 /* TSC could halt in idle, so notify users */
 222                 if (state > ACPI_STATE_C1)
 223                         mark_tsc_unstable("TSC halts in idle");
 224         }
 225 }
 226 #else
 227 static void tsc_check_state(int state) { return; }
 228 #endif
 229
 230 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 231 {
 232
 233         if (!pr->pblk)
 234                 return -ENODEV;
 235
 236         /* if info is obtained from pblk/fadt, type equals state */
 237         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 238         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 239
 240 #ifndef CONFIG_HOTPLUG_CPU
 241         /*
 242          * Check for P_LVL2_UP flag before entering C2 and above on
 243          * an SMP system.
 244          */
 245         if ((num_online_cpus() > 1) &&
 246             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 247                 return -ENODEV;
 248 #endif
 249
 250         /* determine C2 and C3 address from pblk */
 251         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 252         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 253
 254         /* determine latencies from FADT */
 255         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 256         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 257
 258         /*
 259          * FADT specified C2 latency must be less than or equal to
 260          * 100 microseconds.
 261          */
 262         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 263                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 264                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 265                 /* invalidate C2 */
 266                 pr->power.states[ACPI_STATE_C2].address = 0;
 267         }
 268
 269         /*
 270          * FADT supplied C3 latency must be less than or equal to
 271          * 1000 microseconds.
 272          */
 273         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 274                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 275                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 276                 /* invalidate C3 */
 277                 pr->power.states[ACPI_STATE_C3].address = 0;
 278         }
 279
 280         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 281                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 282                           pr->power.states[ACPI_STATE_C2].address,
 283                           pr->power.states[ACPI_STATE_C3].address));
 284
 285         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 286                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 287                          pr->power.states[ACPI_STATE_C2].address);
 288         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 289                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 290                          pr->power.states[ACPI_STATE_C3].address);
 291
 292         return 0;
 293 }
 294
 295 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 296 {
 297         if (!pr->power.states[ACPI_STATE_C1].valid) {
 298                 /* set the first C-State to C1 */
 299                 /* all processors need to support C1 */
 300                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 301                 pr->power.states[ACPI_STATE_C1].valid = 1;
 302                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 303
 304                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 305                          ACPI_CX_DESC_LEN, "ACPI HLT");
 306         }
 307         /* the C0 state only exists as a filler in our array */
 308         pr->power.states[ACPI_STATE_C0].valid = 1;
 309         return 0;
 310 }
 311
 312 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 313 {
 314         acpi_status status;
 315         u64 count;
 316         int current_count;
 317         int i, ret = 0;
 318         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 319         union acpi_object *cst;
 320
 321         if (nocst)
 322                 return -ENODEV;
 323
 324         current_count = 0;
 325
 326         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 327         if (ACPI_FAILURE(status)) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 329                 return -ENODEV;
 330         }
 331
 332         cst = buffer.pointer;
 333
 334         /* There must be at least 2 elements */
 335         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 336                 pr_err("not enough elements in _CST\n");
 337                 ret = -EFAULT;
 338                 goto end;
 339         }
 340
 341         count = cst->package.elements[0].integer.value;
 342
 343         /* Validate number of power states. */
 344         if (count < 1 || count != cst->package.count - 1) {
 345                 pr_err("count given by _CST is not valid\n");
 346                 ret = -EFAULT;
 347                 goto end;
 348         }
 349
 350         /* Tell driver that at least _CST is supported. */
 351         pr->flags.has_cst = 1;
 352
 353         for (i = 1; i <= count; i++) {
 354                 union acpi_object *element;
 355                 union acpi_object *obj;
 356                 struct acpi_power_register *reg;
 357                 struct acpi_processor_cx cx;
 358
 359                 memset(&cx, 0, sizeof(cx));
 360
 361                 element = &(cst->package.elements[i]);
 362                 if (element->type != ACPI_TYPE_PACKAGE)
 363                         continue;
 364
 365                 if (element->package.count != 4)
 366                         continue;
 367
 368                 obj = &(element->package.elements[0]);
 369
 370                 if (obj->type != ACPI_TYPE_BUFFER)
 371                         continue;
 372
 373                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 374
 375                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 376                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 377                         continue;
 378
 379                 /* There should be an easy way to extract an integer... */
 380                 obj = &(element->package.elements[1]);
 381                 if (obj->type != ACPI_TYPE_INTEGER)
 382                         continue;
 383
 384                 cx.type = obj->integer.value;
 385                 /*
 386                  * Some buggy BIOSes won't list C1 in _CST -
 387                  * Let acpi_processor_get_power_info_default() handle them later
 388                  */
 389                 if (i == 1 && cx.type != ACPI_STATE_C1)
 390                         current_count++;
 391
 392                 cx.address = reg->address;
 393                 cx.index = current_count + 1;
 394
 395                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 396                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 397                         if (acpi_processor_ffh_cstate_probe
 398                                         (pr->id, &cx, reg) == 0) {
 399                                 cx.entry_method = ACPI_CSTATE_FFH;
 400                         } else if (cx.type == ACPI_STATE_C1) {
 401                                 /*
 402                                  * C1 is a special case where FIXED_HARDWARE
 403                                  * can be handled in non-MWAIT way as well.
 404                                  * In that case, save this _CST entry info.
 405                                  * Otherwise, ignore this info and continue.
 406                                  */
 407                                 cx.entry_method = ACPI_CSTATE_HALT;
 408                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 409                         } else {
 410                                 continue;
 411                         }
 412                         if (cx.type == ACPI_STATE_C1 &&
 413                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 414                                 /*
 415                                  * In most cases the C1 space_id obtained from
 416                                  * _CST object is FIXED_HARDWARE access mode.
 417                                  * But when the option of idle=halt is added,
 418                                  * the entry_method type should be changed from
 419                                  * CSTATE_FFH to CSTATE_HALT.
 420                                  * When the option of idle=nomwait is added,
 421                                  * the C1 entry_method type should be
 422                                  * CSTATE_HALT.
 423                                  */
 424                                 cx.entry_method = ACPI_CSTATE_HALT;
 425                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 426                         }
 427                 } else {
 428                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 429                                  cx.address);
 430                 }
 431
 432                 if (cx.type == ACPI_STATE_C1) {
 433                         cx.valid = 1;
 434                 }
 435
 436                 obj = &(element->package.elements[2]);
 437                 if (obj->type != ACPI_TYPE_INTEGER)
 438                         continue;
 439
 440                 cx.latency = obj->integer.value;
 441
 442                 obj = &(element->package.elements[3]);
 443                 if (obj->type != ACPI_TYPE_INTEGER)
 444                         continue;
 445
 446                 current_count++;
 447                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 448
 449                 /*
 450                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 451                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 452                  */
 453                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 454                         pr_warn("Limiting number of power states to max (%d)\n",
 455                                 ACPI_PROCESSOR_MAX_POWER);
 456                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 457                         break;
 458                 }
 459         }
 460
 461         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 462                           current_count));
 463
 464         /* Validate number of power states discovered */
 465         if (current_count < 2)
 466                 ret = -EFAULT;
 467
 468       end:
 469         kfree(buffer.pointer);
 470
 471         return ret;
 472 }
 473
 474 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 475                                            struct acpi_processor_cx *cx)
 476 {
 477         static int bm_check_flag = -1;
 478         static int bm_control_flag = -1;
 479
 480
 481         if (!cx->address)
 482                 return;
 483
 484         /*
 485          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 486          * DMA transfers are used by any ISA device to avoid livelock.
 487          * Note that we could disable Type-F DMA (as recommended by
 488          * the erratum), but this is known to disrupt certain ISA
 489          * devices thus we take the conservative approach.
 490          */
 491         else if (errata.piix4.fdma) {
 492                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 493                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 494                 return;
 495         }
 496
 497         /* All the logic here assumes flags.bm_check is same across all CPUs */
 498         if (bm_check_flag == -1) {
 499                 /* Determine whether bm_check is needed based on CPU  */
 500                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 501                 bm_check_flag = pr->flags.bm_check;
 502                 bm_control_flag = pr->flags.bm_control;
 503         } else {
 504                 pr->flags.bm_check = bm_check_flag;
 505                 pr->flags.bm_control = bm_control_flag;
 506         }
 507
 508         if (pr->flags.bm_check) {
 509                 if (!pr->flags.bm_control) {
 510                         if (pr->flags.has_cst != 1) {
 511                                 /* bus mastering control is necessary */
 512                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 513                                         "C3 support requires BM control\n"));
 514                                 return;
 515                         } else {
 516                                 /* Here we enter C3 without bus mastering */
 517                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 518                                         "C3 support without BM control\n"));
 519                         }
 520                 }
 521         } else {
 522                 /*
 523                  * WBINVD should be set in fadt, for C3 state to be
 524                  * supported on when bm_check is not required.
 525                  */
 526                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 527                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 528                                           "Cache invalidation should work properly"
 529                                           " for C3 to be enabled on SMP systems\n"));
 530                         return;
 531                 }
 532         }
 533
 534         /*
 535          * Otherwise we've met all of our C3 requirements.
 536          * Normalize the C3 latency to expidite policy.  Enable
 537          * checking of bus mastering status (bm_check) so we can
 538          * use this in our C3 policy
 539          */
 540         cx->valid = 1;
 541
 542         /*
 543          * On older chipsets, BM_RLD needs to be set
 544          * in order for Bus Master activity to wake the
 545          * system from C3.  Newer chipsets handle DMA
 546          * during C3 automatically and BM_RLD is a NOP.
 547          * In either case, the proper way to
 548          * handle BM_RLD is to set it and leave it set.
 549          */
 550         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 551
 552         return;
 553 }
 554
 555 static int acpi_processor_power_verify(struct acpi_processor *pr)
 556 {
 557         unsigned int i;
 558         unsigned int working = 0;
 559
 560         pr->power.timer_broadcast_on_state = INT_MAX;
 561
 562         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 563                 struct acpi_processor_cx *cx = &pr->power.states[i];
 564
 565                 switch (cx->type) {
 566                 case ACPI_STATE_C1:
 567                         cx->valid = 1;
 568                         break;
 569
 570                 case ACPI_STATE_C2:
 571                         if (!cx->address)
 572                                 break;
 573                         cx->valid = 1;
 574                         break;
 575
 576                 case ACPI_STATE_C3:
 577                         acpi_processor_power_verify_c3(pr, cx);
 578                         break;
 579                 }
 580                 if (!cx->valid)
 581                         continue;
 582
 583                 lapic_timer_check_state(i, pr, cx);
 584                 tsc_check_state(cx->type);
 585                 working++;
 586         }
 587
 588         lapic_timer_propagate_broadcast(pr);
 589
 590         return (working);
 591 }
 592
 593 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 594 {
 595         unsigned int i;
 596         int result;
 597
 598
 599         /* NOTE: the idle thread may not be running while calling
 600          * this function */
 601
 602         /* Zero initialize all the C-states info. */
 603         memset(pr->power.states, 0, sizeof(pr->power.states));
 604
 605         result = acpi_processor_get_power_info_cst(pr);
 606         if (result == -ENODEV)
 607                 result = acpi_processor_get_power_info_fadt(pr);
 608
 609         if (result)
 610                 return result;
 611
 612         acpi_processor_get_power_info_default(pr);
 613
 614         pr->power.count = acpi_processor_power_verify(pr);
 615
 616         /*
 617          * if one state of type C2 or C3 is available, mark this
 618          * CPU as being "idle manageable"
 619          */
 620         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 621                 if (pr->power.states[i].valid) {
 622                         pr->power.count = i;
 623                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 624                                 pr->flags.power = 1;
 625                 }
 626         }
 627
 628         return 0;
 629 }
 630
 631 /**
 632  * acpi_idle_bm_check - checks if bus master activity was detected
 633  */
 634 static int acpi_idle_bm_check(void)
 635 {
 636         u32 bm_status = 0;
 637
 638         if (bm_check_disable)
 639                 return 0;
 640
 641         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 642         if (bm_status)
 643                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 644         /*
 645          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 646          * the true state of bus mastering activity; forcing us to
 647          * manually check the BMIDEA bit of each IDE channel.
 648          */
 649         else if (errata.piix4.bmisx) {
 650                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 651                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 652                         bm_status = 1;
 653         }
 654         return bm_status;
 655 }
 656
 657 /**
 658  * acpi_idle_do_entry - enter idle state using the appropriate method
 659  * @cx: cstate data
 660  *
 661  * Caller disables interrupt before call and enables interrupt after return.
 662  */
 663 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 664 {
 665         if (cx->entry_method == ACPI_CSTATE_FFH) {
 666                 /* Call into architectural FFH based C-state */
 667                 acpi_processor_ffh_cstate_enter(cx);
 668         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 669                 acpi_safe_halt();
 670         } else {
 671                 /* IO port based C-state */
 672                 inb(cx->address);
 673                 /* Dummy wait op - must do something useless after P_LVL2 read
 674                    because chipsets cannot guarantee that STPCLK# signal
 675                    gets asserted in time to freeze execution properly. */
 676                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 677         }
 678 }
 679
 680 /**
 681  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 682  * @dev: the target CPU
 683  * @index: the index of suggested state
 684  */
 685 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 686 {
 687         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 688
 689         ACPI_FLUSH_CPU_CACHE();
 690
 691         while (1) {
 692
 693                 if (cx->entry_method == ACPI_CSTATE_HALT)
 694                         safe_halt();
 695                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 696                         inb(cx->address);
 697                         /* See comment in acpi_idle_do_entry() */
 698                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 699                 } else
 700                         return -ENODEV;
 701         }
 702
 703         /* Never reached */
 704         return 0;
 705 }
 706
 707 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 708 {
 709         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 710                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 711 }
 712
 713 static int c3_cpu_count;
 714 static DEFINE_RAW_SPINLOCK(c3_lock);
 715
 716 /**
 717  * acpi_idle_enter_bm - enters C3 with proper BM handling
 718  * @pr: Target processor
 719  * @cx: Target state context
 720  * @timer_bc: Whether or not to change timer mode to broadcast
 721  */
 722 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 723                                struct acpi_processor_cx *cx, bool timer_bc)
 724 {
 725         acpi_unlazy_tlb(smp_processor_id());
 726
 727         /*
 728          * Must be done before busmaster disable as we might need to
 729          * access HPET !
 730          */
 731         if (timer_bc)
 732                 lapic_timer_state_broadcast(pr, cx, 1);
 733
 734         /*
 735          * disable bus master
 736          * bm_check implies we need ARB_DIS
 737          * bm_control implies whether we can do ARB_DIS
 738          *
 739          * That leaves a case where bm_check is set and bm_control is
 740          * not set. In that case we cannot do much, we enter C3
 741          * without doing anything.
 742          */
 743         if (pr->flags.bm_control) {
 744                 raw_spin_lock(&c3_lock);
 745                 c3_cpu_count++;
 746                 /* Disable bus master arbitration when all CPUs are in C3 */
 747                 if (c3_cpu_count == num_online_cpus())
 748                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 749                 raw_spin_unlock(&c3_lock);
 750         }
 751
 752         acpi_idle_do_entry(cx);
 753
 754         /* Re-enable bus master arbitration */
 755         if (pr->flags.bm_control) {
 756                 raw_spin_lock(&c3_lock);
 757                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 758                 c3_cpu_count--;
 759                 raw_spin_unlock(&c3_lock);
 760         }
 761
 762         if (timer_bc)
 763                 lapic_timer_state_broadcast(pr, cx, 0);
 764 }
 765
 766 static int acpi_idle_enter(struct cpuidle_device *dev,
 767                            struct cpuidle_driver *drv, int index)
 768 {
 769         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 770         struct acpi_processor *pr;
 771
 772         pr = __this_cpu_read(processors);
 773         if (unlikely(!pr))
 774                 return -EINVAL;
 775
 776         if (cx->type != ACPI_STATE_C1) {
 777                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 778                         index = ACPI_IDLE_STATE_START;
 779                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 780                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 781                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 782                                 acpi_idle_enter_bm(pr, cx, true);
 783                                 return index;
 784                         } else if (drv->safe_state_index >= 0) {
 785                                 index = drv->safe_state_index;
 786                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 787                         } else {
 788                                 acpi_safe_halt();
 789                                 return -EBUSY;
 790                         }
 791                 }
 792         }
 793
 794         lapic_timer_state_broadcast(pr, cx, 1);
 795
 796         if (cx->type == ACPI_STATE_C3)
 797                 ACPI_FLUSH_CPU_CACHE();
 798
 799         acpi_idle_do_entry(cx);
 800
 801         lapic_timer_state_broadcast(pr, cx, 0);
 802
 803         return index;
 804 }
 805
 806 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 807                                    struct cpuidle_driver *drv, int index)
 808 {
 809         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 810
 811         if (cx->type == ACPI_STATE_C3) {
 812                 struct acpi_processor *pr = __this_cpu_read(processors);
 813
 814                 if (unlikely(!pr))
 815                         return;
 816
 817                 if (pr->flags.bm_check) {
 818                         acpi_idle_enter_bm(pr, cx, false);
 819                         return;
 820                 } else {
 821                         ACPI_FLUSH_CPU_CACHE();
 822                 }
 823         }
 824         acpi_idle_do_entry(cx);
 825 }
 826
 827 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 828                                            struct cpuidle_device *dev)
 829 {
 830         int i, count = ACPI_IDLE_STATE_START;
 831         struct acpi_processor_cx *cx;
 832
 833         if (max_cstate == 0)
 834                 max_cstate = 1;
 835
 836         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 837                 cx = &pr->power.states[i];
 838
 839                 if (!cx->valid)
 840                         continue;
 841
 842                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 843
 844                 count++;
 845                 if (count == CPUIDLE_STATE_MAX)
 846                         break;
 847         }
 848
 849         if (!count)
 850                 return -EINVAL;
 851
 852         return 0;
 853 }
 854
 855 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 856 {
 857         int i, count;
 858         struct acpi_processor_cx *cx;
 859         struct cpuidle_state *state;
 860         struct cpuidle_driver *drv = &acpi_idle_driver;
 861
 862         if (max_cstate == 0)
 863                 max_cstate = 1;
 864
 865         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 866                 cpuidle_poll_state_init(drv);
 867                 count = 1;
 868         } else {
 869                 count = 0;
 870         }
 871
 872         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 873                 cx = &pr->power.states[i];
 874
 875                 if (!cx->valid)
 876                         continue;
 877
 878                 state = &drv->states[count];
 879                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 880                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 881                 state->exit_latency = cx->latency;
 882                 state->target_residency = cx->latency * latency_factor;
 883                 state->enter = acpi_idle_enter;
 884
 885                 state->flags = 0;
 886                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 887                         state->enter_dead = acpi_idle_play_dead;
 888                         drv->safe_state_index = count;
 889                 }
 890                 /*
 891                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 892                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 893                  * particularly interesting from the suspend-to-idle angle, so
 894                  * avoid C1 and the situations in which we may need to fall back
 895                  * to it altogether.
 896                  */
 897                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 898                         state->enter_s2idle = acpi_idle_enter_s2idle;
 899
 900                 count++;
 901                 if (count == CPUIDLE_STATE_MAX)
 902                         break;
 903         }
 904
 905         drv->state_count = count;
 906
 907         if (!count)
 908                 return -EINVAL;
 909
 910         return 0;
 911 }
 912
 913 static inline void acpi_processor_cstate_first_run_checks(void)
 914 {
 915         acpi_status status;
 916         static int first_run;
 917
 918         if (first_run)
 919                 return;
 920         dmi_check_system(processor_power_dmi_table);
 921         max_cstate = acpi_processor_cstate_check(max_cstate);
 922         if (max_cstate < ACPI_C_STATES_MAX)
 923                 pr_notice("ACPI: processor limited to max C-state %d\n",
 924                           max_cstate);
 925         first_run++;
 926
 927         if (acpi_gbl_FADT.cst_control && !nocst) {
 928                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 929                                             acpi_gbl_FADT.cst_control, 8);
 930                 if (ACPI_FAILURE(status))
 931                         ACPI_EXCEPTION((AE_INFO, status,
 932                                         "Notifying BIOS of _CST ability failed"));
 933         }
 934 }
 935 #else
 936
 937 static inline int disabled_by_idle_boot_param(void) { return 0; }
 938 static inline void acpi_processor_cstate_first_run_checks(void) { }
 939 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 940 {
 941         return -ENODEV;
 942 }
 943
 944 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 945                                            struct cpuidle_device *dev)
 946 {
 947         return -EINVAL;
 948 }
 949
 950 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 951 {
 952         return -EINVAL;
 953 }
 954
 955 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 956
 957 struct acpi_lpi_states_array {
 958         unsigned int size;
 959         unsigned int composite_states_size;
 960         struct acpi_lpi_state *entries;
 961         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 962 };
 963
 964 static int obj_get_integer(union acpi_object *obj, u32 *value)
 965 {
 966         if (obj->type != ACPI_TYPE_INTEGER)
 967                 return -EINVAL;
 968
 969         *value = obj->integer.value;
 970         return 0;
 971 }
 972
 973 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 974                                        struct acpi_lpi_states_array *info)
 975 {
 976         acpi_status status;
 977         int ret = 0;
 978         int pkg_count, state_idx = 1, loop;
 979         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 980         union acpi_object *lpi_data;
 981         struct acpi_lpi_state *lpi_state;
 982
 983         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 984         if (ACPI_FAILURE(status)) {
 985                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 986                 return -ENODEV;
 987         }
 988
 989         lpi_data = buffer.pointer;
 990
 991         /* There must be at least 4 elements = 3 elements + 1 package */
 992         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 993             lpi_data->package.count < 4) {
 994                 pr_debug("not enough elements in _LPI\n");
 995                 ret = -ENODATA;
 996                 goto end;
 997         }
 998
 999         pkg_count = lpi_data->package.elements[2].integer.value;
1000
1001         /* Validate number of power states. */
1002         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
1003                 pr_debug("count given by _LPI is not valid\n");
1004                 ret = -ENODATA;
1005                 goto end;
1006         }
1007
1008         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1009         if (!lpi_state) {
1010                 ret = -ENOMEM;
1011                 goto end;
1012         }
1013
1014         info->size = pkg_count;
1015         info->entries = lpi_state;
1016
1017         /* LPI States start at index 3 */
1018         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1019                 union acpi_object *element, *pkg_elem, *obj;
1020
1021                 element = &lpi_data->package.elements[loop];
1022                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1023                         continue;
1024
1025                 pkg_elem = element->package.elements;
1026
1027                 obj = pkg_elem + 6;
1028                 if (obj->type == ACPI_TYPE_BUFFER) {
1029                         struct acpi_power_register *reg;
1030
1031                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1032                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1033                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1034                                 continue;
1035
1036                         lpi_state->address = reg->address;
1037                         lpi_state->entry_method =
1038                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1039                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1040                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1041                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1042                         lpi_state->address = obj->integer.value;
1043                 } else {
1044                         continue;
1045                 }
1046
1047                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1048
1049                 obj = pkg_elem + 9;
1050                 if (obj->type == ACPI_TYPE_STRING)
1051                         strlcpy(lpi_state->desc, obj->string.pointer,
1052                                 ACPI_CX_DESC_LEN);
1053
1054                 lpi_state->index = state_idx;
1055                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1056                         pr_debug("No min. residency found, assuming 10 us\n");
1057                         lpi_state->min_residency = 10;
1058                 }
1059
1060                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1061                         pr_debug("No wakeup residency found, assuming 10 us\n");
1062                         lpi_state->wake_latency = 10;
1063                 }
1064
1065                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1066                         lpi_state->flags = 0;
1067
1068                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1069                         lpi_state->arch_flags = 0;
1070
1071                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1072                         lpi_state->res_cnt_freq = 1;
1073
1074                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1075                         lpi_state->enable_parent_state = 0;
1076         }
1077
1078         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1079 end:
1080         kfree(buffer.pointer);
1081         return ret;
1082 }
1083
1084 /*
1085  * flat_state_cnt - the number of composite LPI states after the process of flattening
1086  */
1087 static int flat_state_cnt;
1088
1089 /**
1090  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1091  *
1092  * @local: local LPI state
1093  * @parent: parent LPI state
1094  * @result: composite LPI state
1095  */
1096 static bool combine_lpi_states(struct acpi_lpi_state *local,
1097                                struct acpi_lpi_state *parent,
1098                                struct acpi_lpi_state *result)
1099 {
1100         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1101                 if (!parent->address) /* 0 means autopromotable */
1102                         return false;
1103                 result->address = local->address + parent->address;
1104         } else {
1105                 result->address = parent->address;
1106         }
1107
1108         result->min_residency = max(local->min_residency, parent->min_residency);
1109         result->wake_latency = local->wake_latency + parent->wake_latency;
1110         result->enable_parent_state = parent->enable_parent_state;
1111         result->entry_method = local->entry_method;
1112
1113         result->flags = parent->flags;
1114         result->arch_flags = parent->arch_flags;
1115         result->index = parent->index;
1116
1117         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1118         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1119         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1120         return true;
1121 }
1122
1123 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1124
1125 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1126                                   struct acpi_lpi_state *t)
1127 {
1128         curr_level->composite_states[curr_level->composite_states_size++] = t;
1129 }
1130
1131 static int flatten_lpi_states(struct acpi_processor *pr,
1132                               struct acpi_lpi_states_array *curr_level,
1133                               struct acpi_lpi_states_array *prev_level)
1134 {
1135         int i, j, state_count = curr_level->size;
1136         struct acpi_lpi_state *p, *t = curr_level->entries;
1137
1138         curr_level->composite_states_size = 0;
1139         for (j = 0; j < state_count; j++, t++) {
1140                 struct acpi_lpi_state *flpi;
1141
1142                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1143                         continue;
1144
1145                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1146                         pr_warn("Limiting number of LPI states to max (%d)\n",
1147                                 ACPI_PROCESSOR_MAX_POWER);
1148                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1149                         break;
1150                 }
1151
1152                 flpi = &pr->power.lpi_states[flat_state_cnt];
1153
1154                 if (!prev_level) { /* leaf/processor node */
1155                         memcpy(flpi, t, sizeof(*t));
1156                         stash_composite_state(curr_level, flpi);
1157                         flat_state_cnt++;
1158                         continue;
1159                 }
1160
1161                 for (i = 0; i < prev_level->composite_states_size; i++) {
1162                         p = prev_level->composite_states[i];
1163                         if (t->index <= p->enable_parent_state &&
1164                             combine_lpi_states(p, t, flpi)) {
1165                                 stash_composite_state(curr_level, flpi);
1166                                 flat_state_cnt++;
1167                                 flpi++;
1168                         }
1169                 }
1170         }
1171
1172         kfree(curr_level->entries);
1173         return 0;
1174 }
1175
1176 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1177 {
1178         int ret, i;
1179         acpi_status status;
1180         acpi_handle handle = pr->handle, pr_ahandle;
1181         struct acpi_device *d = NULL;
1182         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1183
1184         if (!osc_pc_lpi_support_confirmed)
1185                 return -EOPNOTSUPP;
1186
1187         if (!acpi_has_method(handle, "_LPI"))
1188                 return -EINVAL;
1189
1190         flat_state_cnt = 0;
1191         prev = &info[0];
1192         curr = &info[1];
1193         handle = pr->handle;
1194         ret = acpi_processor_evaluate_lpi(handle, prev);
1195         if (ret)
1196                 return ret;
1197         flatten_lpi_states(pr, prev, NULL);
1198
1199         status = acpi_get_parent(handle, &pr_ahandle);
1200         while (ACPI_SUCCESS(status)) {
1201                 acpi_bus_get_device(pr_ahandle, &d);
1202                 handle = pr_ahandle;
1203
1204                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1205                         break;
1206
1207                 /* can be optional ? */
1208                 if (!acpi_has_method(handle, "_LPI"))
1209                         break;
1210
1211                 ret = acpi_processor_evaluate_lpi(handle, curr);
1212                 if (ret)
1213                         break;
1214
1215                 /* flatten all the LPI states in this level of hierarchy */
1216                 flatten_lpi_states(pr, curr, prev);
1217
1218                 tmp = prev, prev = curr, curr = tmp;
1219
1220                 status = acpi_get_parent(handle, &pr_ahandle);
1221         }
1222
1223         pr->power.count = flat_state_cnt;
1224         /* reset the index after flattening */
1225         for (i = 0; i < pr->power.count; i++)
1226                 pr->power.lpi_states[i].index = i;
1227
1228         /* Tell driver that _LPI is supported. */
1229         pr->flags.has_lpi = 1;
1230         pr->flags.power = 1;
1231
1232         return 0;
1233 }
1234
1235 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1236 {
1237         return -ENODEV;
1238 }
1239
1240 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1241 {
1242         return -ENODEV;
1243 }
1244
1245 /**
1246  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1247  * @dev: the target CPU
1248  * @drv: cpuidle driver containing cpuidle state info
1249  * @index: index of target state
1250  *
1251  * Return: 0 for success or negative value for error
1252  */
1253 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1254                                struct cpuidle_driver *drv, int index)
1255 {
1256         struct acpi_processor *pr;
1257         struct acpi_lpi_state *lpi;
1258
1259         pr = __this_cpu_read(processors);
1260
1261         if (unlikely(!pr))
1262                 return -EINVAL;
1263
1264         lpi = &pr->power.lpi_states[index];
1265         if (lpi->entry_method == ACPI_CSTATE_FFH)
1266                 return acpi_processor_ffh_lpi_enter(lpi);
1267
1268         return -EINVAL;
1269 }
1270
1271 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1272 {
1273         int i;
1274         struct acpi_lpi_state *lpi;
1275         struct cpuidle_state *state;
1276         struct cpuidle_driver *drv = &acpi_idle_driver;
1277
1278         if (!pr->flags.has_lpi)
1279                 return -EOPNOTSUPP;
1280
1281         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1282                 lpi = &pr->power.lpi_states[i];
1283
1284                 state = &drv->states[i];
1285                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1286                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1287                 state->exit_latency = lpi->wake_latency;
1288                 state->target_residency = lpi->min_residency;
1289                 if (lpi->arch_flags)
1290                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1291                 state->enter = acpi_idle_lpi_enter;
1292                 drv->safe_state_index = i;
1293         }
1294
1295         drv->state_count = i;
1296
1297         return 0;
1298 }
1299
1300 /**
1301  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1302  * global state data i.e. idle routines
1303  *
1304  * @pr: the ACPI processor
1305  */
1306 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1307 {
1308         int i;
1309         struct cpuidle_driver *drv = &acpi_idle_driver;
1310
1311         if (!pr->flags.power_setup_done || !pr->flags.power)
1312                 return -EINVAL;
1313
1314         drv->safe_state_index = -1;
1315         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1316                 drv->states[i].name[0] = '\0';
1317                 drv->states[i].desc[0] = '\0';
1318         }
1319
1320         if (pr->flags.has_lpi)
1321                 return acpi_processor_setup_lpi_states(pr);
1322
1323         return acpi_processor_setup_cstates(pr);
1324 }
1325
1326 /**
1327  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1328  * device i.e. per-cpu data
1329  *
1330  * @pr: the ACPI processor
1331  * @dev : the cpuidle device
1332  */
1333 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1334                                             struct cpuidle_device *dev)
1335 {
1336         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1337                 return -EINVAL;
1338
1339         dev->cpu = pr->id;
1340         if (pr->flags.has_lpi)
1341                 return acpi_processor_ffh_lpi_probe(pr->id);
1342
1343         return acpi_processor_setup_cpuidle_cx(pr, dev);
1344 }
1345
1346 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1347 {
1348         int ret;
1349
1350         ret = acpi_processor_get_lpi_info(pr);
1351         if (ret)
1352                 ret = acpi_processor_get_cstate_info(pr);
1353
1354         return ret;
1355 }
1356
1357 int acpi_processor_hotplug(struct acpi_processor *pr)
1358 {
1359         int ret = 0;
1360         struct cpuidle_device *dev;
1361
1362         if (disabled_by_idle_boot_param())
1363                 return 0;
1364
1365         if (!pr->flags.power_setup_done)
1366                 return -ENODEV;
1367
1368         dev = per_cpu(acpi_cpuidle_device, pr->id);
1369         cpuidle_pause_and_lock();
1370         cpuidle_disable_device(dev);
1371         ret = acpi_processor_get_power_info(pr);
1372         if (!ret && pr->flags.power) {
1373                 acpi_processor_setup_cpuidle_dev(pr, dev);
1374                 ret = cpuidle_enable_device(dev);
1375         }
1376         cpuidle_resume_and_unlock();
1377
1378         return ret;
1379 }
1380
1381 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1382 {
1383         int cpu;
1384         struct acpi_processor *_pr;
1385         struct cpuidle_device *dev;
1386
1387         if (disabled_by_idle_boot_param())
1388                 return 0;
1389
1390         if (!pr->flags.power_setup_done)
1391                 return -ENODEV;
1392
1393         /*
1394          * FIXME:  Design the ACPI notification to make it once per
1395          * system instead of once per-cpu.  This condition is a hack
1396          * to make the code that updates C-States be called once.
1397          */
1398
1399         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1400
1401                 /* Protect against cpu-hotplug */
1402                 get_online_cpus();
1403                 cpuidle_pause_and_lock();
1404
1405                 /* Disable all cpuidle devices */
1406                 for_each_online_cpu(cpu) {
1407                         _pr = per_cpu(processors, cpu);
1408                         if (!_pr || !_pr->flags.power_setup_done)
1409                                 continue;
1410                         dev = per_cpu(acpi_cpuidle_device, cpu);
1411                         cpuidle_disable_device(dev);
1412                 }
1413
1414                 /* Populate Updated C-state information */
1415                 acpi_processor_get_power_info(pr);
1416                 acpi_processor_setup_cpuidle_states(pr);
1417
1418                 /* Enable all cpuidle devices */
1419                 for_each_online_cpu(cpu) {
1420                         _pr = per_cpu(processors, cpu);
1421                         if (!_pr || !_pr->flags.power_setup_done)
1422                                 continue;
1423                         acpi_processor_get_power_info(_pr);
1424                         if (_pr->flags.power) {
1425                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1426                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1427                                 cpuidle_enable_device(dev);
1428                         }
1429                 }
1430                 cpuidle_resume_and_unlock();
1431                 put_online_cpus();
1432         }
1433
1434         return 0;
1435 }
1436
1437 static int acpi_processor_registered;
1438
1439 int acpi_processor_power_init(struct acpi_processor *pr)
1440 {
1441         int retval;
1442         struct cpuidle_device *dev;
1443
1444         if (disabled_by_idle_boot_param())
1445                 return 0;
1446
1447         acpi_processor_cstate_first_run_checks();
1448
1449         if (!acpi_processor_get_power_info(pr))
1450                 pr->flags.power_setup_done = 1;
1451
1452         /*
1453          * Install the idle handler if processor power management is supported.
1454          * Note that we use previously set idle handler will be used on
1455          * platforms that only support C1.
1456          */
1457         if (pr->flags.power) {
1458                 /* Register acpi_idle_driver if not already registered */
1459                 if (!acpi_processor_registered) {
1460                         acpi_processor_setup_cpuidle_states(pr);
1461                         retval = cpuidle_register_driver(&acpi_idle_driver);
1462                         if (retval)
1463                                 return retval;
1464                         pr_debug("%s registered with cpuidle\n",
1465                                  acpi_idle_driver.name);
1466                 }
1467
1468                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1469                 if (!dev)
1470                         return -ENOMEM;
1471                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1472
1473                 acpi_processor_setup_cpuidle_dev(pr, dev);
1474
1475                 /* Register per-cpu cpuidle_device. Cpuidle driver
1476                  * must already be registered before registering device
1477                  */
1478                 retval = cpuidle_register_device(dev);
1479                 if (retval) {
1480                         if (acpi_processor_registered == 0)
1481                                 cpuidle_unregister_driver(&acpi_idle_driver);
1482                         return retval;
1483                 }
1484                 acpi_processor_registered++;
1485         }
1486         return 0;
1487 }
1488
1489 int acpi_processor_power_exit(struct acpi_processor *pr)
1490 {
1491         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1492
1493         if (disabled_by_idle_boot_param())
1494                 return 0;
1495
1496         if (pr->flags.power) {
1497                 cpuidle_unregister_device(dev);
1498                 acpi_processor_registered--;
1499                 if (acpi_processor_registered == 0)
1500                         cpuidle_unregister_driver(&acpi_idle_driver);
1501         }
1502
1503         pr->flags.power_setup_done = 0;
1504         return 0;
1505 }