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 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  52 module_param(max_cstate, uint, 0000);
  53 static unsigned int nocst __read_mostly;
  54 module_param(nocst, uint, 0000);
  55 static int bm_check_disable __read_mostly;
  56 module_param(bm_check_disable, uint, 0000);
  57
  58 static unsigned int latency_factor __read_mostly = 2;
  59 module_param(latency_factor, uint, 0644);
  60
  61 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  62
  63 struct cpuidle_driver acpi_idle_driver = {
  64         .name =         "acpi_idle",
  65         .owner =        THIS_MODULE,
  66 };
  67
  68 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  69 static
  70 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  71
  72 static int disabled_by_idle_boot_param(void)
  73 {
  74         return boot_option_idle_override == IDLE_POLL ||
  75                 boot_option_idle_override == IDLE_HALT;
  76 }
  77
  78 /*
  79  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  80  * For now disable this. Probably a bug somewhere else.
  81  *
  82  * To skip this limit, boot/load with a large max_cstate limit.
  83  */
  84 static int set_max_cstate(const struct dmi_system_id *id)
  85 {
  86         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  87                 return 0;
  88
  89         pr_notice("%s detected - limiting to C%ld max_cstate."
  90                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  91                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  92
  93         max_cstate = (long)id->driver_data;
  94
  95         return 0;
  96 }
  97
  98 static const struct dmi_system_id processor_power_dmi_table[] = {
  99         { set_max_cstate, "Clevo 5600D", {
 100           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 101           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 102          (void *)2},
 103         { set_max_cstate, "Pavilion zv5000", {
 104           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 105           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 106          (void *)1},
 107         { set_max_cstate, "Asus L8400B", {
 108           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 109           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 110          (void *)1},
 111         {},
 112 };
 113
 114
 115 /*
 116  * Callers should disable interrupts before the call and enable
 117  * interrupts after return.
 118  */
 119 static void __cpuidle acpi_safe_halt(void)
 120 {
 121         if (!tif_need_resched()) {
 122                 safe_halt();
 123                 local_irq_disable();
 124         }
 125 }
 126
 127 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 128
 129 /*
 130  * Some BIOS implementations switch to C3 in the published C2 state.
 131  * This seems to be a common problem on AMD boxen, but other vendors
 132  * are affected too. We pick the most conservative approach: we assume
 133  * that the local APIC stops in both C2 and C3.
 134  */
 135 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 136                                    struct acpi_processor_cx *cx)
 137 {
 138         struct acpi_processor_power *pwr = &pr->power;
 139         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 140
 141         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 142                 return;
 143
 144         if (amd_e400_c1e_detected)
 145                 type = ACPI_STATE_C1;
 146
 147         /*
 148          * Check, if one of the previous states already marked the lapic
 149          * unstable
 150          */
 151         if (pwr->timer_broadcast_on_state < state)
 152                 return;
 153
 154         if (cx->type >= type)
 155                 pr->power.timer_broadcast_on_state = state;
 156 }
 157
 158 static void __lapic_timer_propagate_broadcast(void *arg)
 159 {
 160         struct acpi_processor *pr = (struct acpi_processor *) arg;
 161
 162         if (pr->power.timer_broadcast_on_state < INT_MAX)
 163                 tick_broadcast_enable();
 164         else
 165                 tick_broadcast_disable();
 166 }
 167
 168 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 169 {
 170         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 171                                  (void *)pr, 1);
 172 }
 173
 174 /* Power(C) State timer broadcast control */
 175 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 176                                        struct acpi_processor_cx *cx,
 177                                        int broadcast)
 178 {
 179         int state = cx - pr->power.states;
 180
 181         if (state >= pr->power.timer_broadcast_on_state) {
 182                 if (broadcast)
 183                         tick_broadcast_enter();
 184                 else
 185                         tick_broadcast_exit();
 186         }
 187 }
 188
 189 #else
 190
 191 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 192                                    struct acpi_processor_cx *cstate) { }
 193 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 194 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 195                                        struct acpi_processor_cx *cx,
 196                                        int broadcast)
 197 {
 198 }
 199
 200 #endif
 201
 202 #if defined(CONFIG_X86)
 203 static void tsc_check_state(int state)
 204 {
 205         switch (boot_cpu_data.x86_vendor) {
 206         case X86_VENDOR_AMD:
 207         case X86_VENDOR_INTEL:
 208                 /*
 209                  * AMD Fam10h TSC will tick in all
 210                  * C/P/S0/S1 states when this bit is set.
 211                  */
 212                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 213                         return;
 214
 215                 /*FALL THROUGH*/
 216         default:
 217                 /* TSC could halt in idle, so notify users */
 218                 if (state > ACPI_STATE_C1)
 219                         mark_tsc_unstable("TSC halts in idle");
 220         }
 221 }
 222 #else
 223 static void tsc_check_state(int state) { return; }
 224 #endif
 225
 226 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 227 {
 228
 229         if (!pr->pblk)
 230                 return -ENODEV;
 231
 232         /* if info is obtained from pblk/fadt, type equals state */
 233         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 234         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 235
 236 #ifndef CONFIG_HOTPLUG_CPU
 237         /*
 238          * Check for P_LVL2_UP flag before entering C2 and above on
 239          * an SMP system.
 240          */
 241         if ((num_online_cpus() > 1) &&
 242             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 243                 return -ENODEV;
 244 #endif
 245
 246         /* determine C2 and C3 address from pblk */
 247         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 248         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 249
 250         /* determine latencies from FADT */
 251         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 252         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 253
 254         /*
 255          * FADT specified C2 latency must be less than or equal to
 256          * 100 microseconds.
 257          */
 258         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 259                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 260                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 261                 /* invalidate C2 */
 262                 pr->power.states[ACPI_STATE_C2].address = 0;
 263         }
 264
 265         /*
 266          * FADT supplied C3 latency must be less than or equal to
 267          * 1000 microseconds.
 268          */
 269         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 270                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 271                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 272                 /* invalidate C3 */
 273                 pr->power.states[ACPI_STATE_C3].address = 0;
 274         }
 275
 276         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 277                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 278                           pr->power.states[ACPI_STATE_C2].address,
 279                           pr->power.states[ACPI_STATE_C3].address));
 280
 281         return 0;
 282 }
 283
 284 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 285 {
 286         if (!pr->power.states[ACPI_STATE_C1].valid) {
 287                 /* set the first C-State to C1 */
 288                 /* all processors need to support C1 */
 289                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 290                 pr->power.states[ACPI_STATE_C1].valid = 1;
 291                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 292         }
 293         /* the C0 state only exists as a filler in our array */
 294         pr->power.states[ACPI_STATE_C0].valid = 1;
 295         return 0;
 296 }
 297
 298 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 299 {
 300         acpi_status status;
 301         u64 count;
 302         int current_count;
 303         int i, ret = 0;
 304         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 305         union acpi_object *cst;
 306
 307         if (nocst)
 308                 return -ENODEV;
 309
 310         current_count = 0;
 311
 312         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 313         if (ACPI_FAILURE(status)) {
 314                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 315                 return -ENODEV;
 316         }
 317
 318         cst = buffer.pointer;
 319
 320         /* There must be at least 2 elements */
 321         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 322                 pr_err("not enough elements in _CST\n");
 323                 ret = -EFAULT;
 324                 goto end;
 325         }
 326
 327         count = cst->package.elements[0].integer.value;
 328
 329         /* Validate number of power states. */
 330         if (count < 1 || count != cst->package.count - 1) {
 331                 pr_err("count given by _CST is not valid\n");
 332                 ret = -EFAULT;
 333                 goto end;
 334         }
 335
 336         /* Tell driver that at least _CST is supported. */
 337         pr->flags.has_cst = 1;
 338
 339         for (i = 1; i <= count; i++) {
 340                 union acpi_object *element;
 341                 union acpi_object *obj;
 342                 struct acpi_power_register *reg;
 343                 struct acpi_processor_cx cx;
 344
 345                 memset(&cx, 0, sizeof(cx));
 346
 347                 element = &(cst->package.elements[i]);
 348                 if (element->type != ACPI_TYPE_PACKAGE)
 349                         continue;
 350
 351                 if (element->package.count != 4)
 352                         continue;
 353
 354                 obj = &(element->package.elements[0]);
 355
 356                 if (obj->type != ACPI_TYPE_BUFFER)
 357                         continue;
 358
 359                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 360
 361                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 362                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 363                         continue;
 364
 365                 /* There should be an easy way to extract an integer... */
 366                 obj = &(element->package.elements[1]);
 367                 if (obj->type != ACPI_TYPE_INTEGER)
 368                         continue;
 369
 370                 cx.type = obj->integer.value;
 371                 /*
 372                  * Some buggy BIOSes won't list C1 in _CST -
 373                  * Let acpi_processor_get_power_info_default() handle them later
 374                  */
 375                 if (i == 1 && cx.type != ACPI_STATE_C1)
 376                         current_count++;
 377
 378                 cx.address = reg->address;
 379                 cx.index = current_count + 1;
 380
 381                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 382                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 383                         if (acpi_processor_ffh_cstate_probe
 384                                         (pr->id, &cx, reg) == 0) {
 385                                 cx.entry_method = ACPI_CSTATE_FFH;
 386                         } else if (cx.type == ACPI_STATE_C1) {
 387                                 /*
 388                                  * C1 is a special case where FIXED_HARDWARE
 389                                  * can be handled in non-MWAIT way as well.
 390                                  * In that case, save this _CST entry info.
 391                                  * Otherwise, ignore this info and continue.
 392                                  */
 393                                 cx.entry_method = ACPI_CSTATE_HALT;
 394                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 395                         } else {
 396                                 continue;
 397                         }
 398                         if (cx.type == ACPI_STATE_C1 &&
 399                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 400                                 /*
 401                                  * In most cases the C1 space_id obtained from
 402                                  * _CST object is FIXED_HARDWARE access mode.
 403                                  * But when the option of idle=halt is added,
 404                                  * the entry_method type should be changed from
 405                                  * CSTATE_FFH to CSTATE_HALT.
 406                                  * When the option of idle=nomwait is added,
 407                                  * the C1 entry_method type should be
 408                                  * CSTATE_HALT.
 409                                  */
 410                                 cx.entry_method = ACPI_CSTATE_HALT;
 411                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 412                         }
 413                 } else {
 414                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 415                                  cx.address);
 416                 }
 417
 418                 if (cx.type == ACPI_STATE_C1) {
 419                         cx.valid = 1;
 420                 }
 421
 422                 obj = &(element->package.elements[2]);
 423                 if (obj->type != ACPI_TYPE_INTEGER)
 424                         continue;
 425
 426                 cx.latency = obj->integer.value;
 427
 428                 obj = &(element->package.elements[3]);
 429                 if (obj->type != ACPI_TYPE_INTEGER)
 430                         continue;
 431
 432                 current_count++;
 433                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 434
 435                 /*
 436                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 437                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 438                  */
 439                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 440                         pr_warn("Limiting number of power states to max (%d)\n",
 441                                 ACPI_PROCESSOR_MAX_POWER);
 442                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 443                         break;
 444                 }
 445         }
 446
 447         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 448                           current_count));
 449
 450         /* Validate number of power states discovered */
 451         if (current_count < 2)
 452                 ret = -EFAULT;
 453
 454       end:
 455         kfree(buffer.pointer);
 456
 457         return ret;
 458 }
 459
 460 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 461                                            struct acpi_processor_cx *cx)
 462 {
 463         static int bm_check_flag = -1;
 464         static int bm_control_flag = -1;
 465
 466
 467         if (!cx->address)
 468                 return;
 469
 470         /*
 471          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 472          * DMA transfers are used by any ISA device to avoid livelock.
 473          * Note that we could disable Type-F DMA (as recommended by
 474          * the erratum), but this is known to disrupt certain ISA
 475          * devices thus we take the conservative approach.
 476          */
 477         else if (errata.piix4.fdma) {
 478                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 479                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 480                 return;
 481         }
 482
 483         /* All the logic here assumes flags.bm_check is same across all CPUs */
 484         if (bm_check_flag == -1) {
 485                 /* Determine whether bm_check is needed based on CPU  */
 486                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 487                 bm_check_flag = pr->flags.bm_check;
 488                 bm_control_flag = pr->flags.bm_control;
 489         } else {
 490                 pr->flags.bm_check = bm_check_flag;
 491                 pr->flags.bm_control = bm_control_flag;
 492         }
 493
 494         if (pr->flags.bm_check) {
 495                 if (!pr->flags.bm_control) {
 496                         if (pr->flags.has_cst != 1) {
 497                                 /* bus mastering control is necessary */
 498                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 499                                         "C3 support requires BM control\n"));
 500                                 return;
 501                         } else {
 502                                 /* Here we enter C3 without bus mastering */
 503                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 504                                         "C3 support without BM control\n"));
 505                         }
 506                 }
 507         } else {
 508                 /*
 509                  * WBINVD should be set in fadt, for C3 state to be
 510                  * supported on when bm_check is not required.
 511                  */
 512                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 513                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 514                                           "Cache invalidation should work properly"
 515                                           " for C3 to be enabled on SMP systems\n"));
 516                         return;
 517                 }
 518         }
 519
 520         /*
 521          * Otherwise we've met all of our C3 requirements.
 522          * Normalize the C3 latency to expidite policy.  Enable
 523          * checking of bus mastering status (bm_check) so we can
 524          * use this in our C3 policy
 525          */
 526         cx->valid = 1;
 527
 528         /*
 529          * On older chipsets, BM_RLD needs to be set
 530          * in order for Bus Master activity to wake the
 531          * system from C3.  Newer chipsets handle DMA
 532          * during C3 automatically and BM_RLD is a NOP.
 533          * In either case, the proper way to
 534          * handle BM_RLD is to set it and leave it set.
 535          */
 536         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 537
 538         return;
 539 }
 540
 541 static int acpi_processor_power_verify(struct acpi_processor *pr)
 542 {
 543         unsigned int i;
 544         unsigned int working = 0;
 545
 546         pr->power.timer_broadcast_on_state = INT_MAX;
 547
 548         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 549                 struct acpi_processor_cx *cx = &pr->power.states[i];
 550
 551                 switch (cx->type) {
 552                 case ACPI_STATE_C1:
 553                         cx->valid = 1;
 554                         break;
 555
 556                 case ACPI_STATE_C2:
 557                         if (!cx->address)
 558                                 break;
 559                         cx->valid = 1;
 560                         break;
 561
 562                 case ACPI_STATE_C3:
 563                         acpi_processor_power_verify_c3(pr, cx);
 564                         break;
 565                 }
 566                 if (!cx->valid)
 567                         continue;
 568
 569                 lapic_timer_check_state(i, pr, cx);
 570                 tsc_check_state(cx->type);
 571                 working++;
 572         }
 573
 574         lapic_timer_propagate_broadcast(pr);
 575
 576         return (working);
 577 }
 578
 579 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 580 {
 581         unsigned int i;
 582         int result;
 583
 584
 585         /* NOTE: the idle thread may not be running while calling
 586          * this function */
 587
 588         /* Zero initialize all the C-states info. */
 589         memset(pr->power.states, 0, sizeof(pr->power.states));
 590
 591         result = acpi_processor_get_power_info_cst(pr);
 592         if (result == -ENODEV)
 593                 result = acpi_processor_get_power_info_fadt(pr);
 594
 595         if (result)
 596                 return result;
 597
 598         acpi_processor_get_power_info_default(pr);
 599
 600         pr->power.count = acpi_processor_power_verify(pr);
 601
 602         /*
 603          * if one state of type C2 or C3 is available, mark this
 604          * CPU as being "idle manageable"
 605          */
 606         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 607                 if (pr->power.states[i].valid) {
 608                         pr->power.count = i;
 609                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 610                                 pr->flags.power = 1;
 611                 }
 612         }
 613
 614         return 0;
 615 }
 616
 617 /**
 618  * acpi_idle_bm_check - checks if bus master activity was detected
 619  */
 620 static int acpi_idle_bm_check(void)
 621 {
 622         u32 bm_status = 0;
 623
 624         if (bm_check_disable)
 625                 return 0;
 626
 627         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 628         if (bm_status)
 629                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 630         /*
 631          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 632          * the true state of bus mastering activity; forcing us to
 633          * manually check the BMIDEA bit of each IDE channel.
 634          */
 635         else if (errata.piix4.bmisx) {
 636                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 637                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 638                         bm_status = 1;
 639         }
 640         return bm_status;
 641 }
 642
 643 /**
 644  * acpi_idle_do_entry - enter idle state using the appropriate method
 645  * @cx: cstate data
 646  *
 647  * Caller disables interrupt before call and enables interrupt after return.
 648  */
 649 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 650 {
 651         if (cx->entry_method == ACPI_CSTATE_FFH) {
 652                 /* Call into architectural FFH based C-state */
 653                 acpi_processor_ffh_cstate_enter(cx);
 654         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 655                 acpi_safe_halt();
 656         } else {
 657                 /* IO port based C-state */
 658                 inb(cx->address);
 659                 /* Dummy wait op - must do something useless after P_LVL2 read
 660                    because chipsets cannot guarantee that STPCLK# signal
 661                    gets asserted in time to freeze execution properly. */
 662                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 663         }
 664 }
 665
 666 /**
 667  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 668  * @dev: the target CPU
 669  * @index: the index of suggested state
 670  */
 671 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 672 {
 673         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 674
 675         ACPI_FLUSH_CPU_CACHE();
 676
 677         while (1) {
 678
 679                 if (cx->entry_method == ACPI_CSTATE_HALT)
 680                         safe_halt();
 681                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 682                         inb(cx->address);
 683                         /* See comment in acpi_idle_do_entry() */
 684                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 685                 } else
 686                         return -ENODEV;
 687         }
 688
 689         /* Never reached */
 690         return 0;
 691 }
 692
 693 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 694 {
 695         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 696                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 697 }
 698
 699 static int c3_cpu_count;
 700 static DEFINE_RAW_SPINLOCK(c3_lock);
 701
 702 /**
 703  * acpi_idle_enter_bm - enters C3 with proper BM handling
 704  * @pr: Target processor
 705  * @cx: Target state context
 706  * @timer_bc: Whether or not to change timer mode to broadcast
 707  */
 708 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 709                                struct acpi_processor_cx *cx, bool timer_bc)
 710 {
 711         acpi_unlazy_tlb(smp_processor_id());
 712
 713         /*
 714          * Must be done before busmaster disable as we might need to
 715          * access HPET !
 716          */
 717         if (timer_bc)
 718                 lapic_timer_state_broadcast(pr, cx, 1);
 719
 720         /*
 721          * disable bus master
 722          * bm_check implies we need ARB_DIS
 723          * bm_control implies whether we can do ARB_DIS
 724          *
 725          * That leaves a case where bm_check is set and bm_control is
 726          * not set. In that case we cannot do much, we enter C3
 727          * without doing anything.
 728          */
 729         if (pr->flags.bm_control) {
 730                 raw_spin_lock(&c3_lock);
 731                 c3_cpu_count++;
 732                 /* Disable bus master arbitration when all CPUs are in C3 */
 733                 if (c3_cpu_count == num_online_cpus())
 734                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 735                 raw_spin_unlock(&c3_lock);
 736         }
 737
 738         acpi_idle_do_entry(cx);
 739
 740         /* Re-enable bus master arbitration */
 741         if (pr->flags.bm_control) {
 742                 raw_spin_lock(&c3_lock);
 743                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 744                 c3_cpu_count--;
 745                 raw_spin_unlock(&c3_lock);
 746         }
 747
 748         if (timer_bc)
 749                 lapic_timer_state_broadcast(pr, cx, 0);
 750 }
 751
 752 static int acpi_idle_enter(struct cpuidle_device *dev,
 753                            struct cpuidle_driver *drv, int index)
 754 {
 755         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 756         struct acpi_processor *pr;
 757
 758         pr = __this_cpu_read(processors);
 759         if (unlikely(!pr))
 760                 return -EINVAL;
 761
 762         if (cx->type != ACPI_STATE_C1) {
 763                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 764                         index = CPUIDLE_DRIVER_STATE_START;
 765                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 766                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 767                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 768                                 acpi_idle_enter_bm(pr, cx, true);
 769                                 return index;
 770                         } else if (drv->safe_state_index >= 0) {
 771                                 index = drv->safe_state_index;
 772                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 773                         } else {
 774                                 acpi_safe_halt();
 775                                 return -EBUSY;
 776                         }
 777                 }
 778         }
 779
 780         lapic_timer_state_broadcast(pr, cx, 1);
 781
 782         if (cx->type == ACPI_STATE_C3)
 783                 ACPI_FLUSH_CPU_CACHE();
 784
 785         acpi_idle_do_entry(cx);
 786
 787         lapic_timer_state_broadcast(pr, cx, 0);
 788
 789         return index;
 790 }
 791
 792 static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
 793                                    struct cpuidle_driver *drv, int index)
 794 {
 795         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 796
 797         if (cx->type == ACPI_STATE_C3) {
 798                 struct acpi_processor *pr = __this_cpu_read(processors);
 799
 800                 if (unlikely(!pr))
 801                         return;
 802
 803                 if (pr->flags.bm_check) {
 804                         acpi_idle_enter_bm(pr, cx, false);
 805                         return;
 806                 } else {
 807                         ACPI_FLUSH_CPU_CACHE();
 808                 }
 809         }
 810         acpi_idle_do_entry(cx);
 811 }
 812
 813 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 814                                            struct cpuidle_device *dev)
 815 {
 816         int i, count = CPUIDLE_DRIVER_STATE_START;
 817         struct acpi_processor_cx *cx;
 818
 819         if (max_cstate == 0)
 820                 max_cstate = 1;
 821
 822         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 823                 cx = &pr->power.states[i];
 824
 825                 if (!cx->valid)
 826                         continue;
 827
 828                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 829
 830                 count++;
 831                 if (count == CPUIDLE_STATE_MAX)
 832                         break;
 833         }
 834
 835         if (!count)
 836                 return -EINVAL;
 837
 838         return 0;
 839 }
 840
 841 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 842 {
 843         int i, count = CPUIDLE_DRIVER_STATE_START;
 844         struct acpi_processor_cx *cx;
 845         struct cpuidle_state *state;
 846         struct cpuidle_driver *drv = &acpi_idle_driver;
 847
 848         if (max_cstate == 0)
 849                 max_cstate = 1;
 850
 851         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 852                 cx = &pr->power.states[i];
 853
 854                 if (!cx->valid)
 855                         continue;
 856
 857                 state = &drv->states[count];
 858                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 859                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 860                 state->exit_latency = cx->latency;
 861                 state->target_residency = cx->latency * latency_factor;
 862                 state->enter = acpi_idle_enter;
 863
 864                 state->flags = 0;
 865                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 866                         state->enter_dead = acpi_idle_play_dead;
 867                         drv->safe_state_index = count;
 868                 }
 869                 /*
 870                  * Halt-induced C1 is not good for ->enter_freeze, because it
 871                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 872                  * particularly interesting from the suspend-to-idle angle, so
 873                  * avoid C1 and the situations in which we may need to fall back
 874                  * to it altogether.
 875                  */
 876                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 877                         state->enter_freeze = acpi_idle_enter_freeze;
 878
 879                 count++;
 880                 if (count == CPUIDLE_STATE_MAX)
 881                         break;
 882         }
 883
 884         drv->state_count = count;
 885
 886         if (!count)
 887                 return -EINVAL;
 888
 889         return 0;
 890 }
 891
 892 static inline void acpi_processor_cstate_first_run_checks(void)
 893 {
 894         acpi_status status;
 895         static int first_run;
 896
 897         if (first_run)
 898                 return;
 899         dmi_check_system(processor_power_dmi_table);
 900         max_cstate = acpi_processor_cstate_check(max_cstate);
 901         if (max_cstate < ACPI_C_STATES_MAX)
 902                 pr_notice("ACPI: processor limited to max C-state %d\n",
 903                           max_cstate);
 904         first_run++;
 905
 906         if (acpi_gbl_FADT.cst_control && !nocst) {
 907                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 908                                             acpi_gbl_FADT.cst_control, 8);
 909                 if (ACPI_FAILURE(status))
 910                         ACPI_EXCEPTION((AE_INFO, status,
 911                                         "Notifying BIOS of _CST ability failed"));
 912         }
 913 }
 914 #else
 915
 916 static inline int disabled_by_idle_boot_param(void) { return 0; }
 917 static inline void acpi_processor_cstate_first_run_checks(void) { }
 918 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 919 {
 920         return -ENODEV;
 921 }
 922
 923 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 924                                            struct cpuidle_device *dev)
 925 {
 926         return -EINVAL;
 927 }
 928
 929 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 930 {
 931         return -EINVAL;
 932 }
 933
 934 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 935
 936 struct acpi_lpi_states_array {
 937         unsigned int size;
 938         unsigned int composite_states_size;
 939         struct acpi_lpi_state *entries;
 940         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 941 };
 942
 943 static int obj_get_integer(union acpi_object *obj, u32 *value)
 944 {
 945         if (obj->type != ACPI_TYPE_INTEGER)
 946                 return -EINVAL;
 947
 948         *value = obj->integer.value;
 949         return 0;
 950 }
 951
 952 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 953                                        struct acpi_lpi_states_array *info)
 954 {
 955         acpi_status status;
 956         int ret = 0;
 957         int pkg_count, state_idx = 1, loop;
 958         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 959         union acpi_object *lpi_data;
 960         struct acpi_lpi_state *lpi_state;
 961
 962         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 963         if (ACPI_FAILURE(status)) {
 964                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 965                 return -ENODEV;
 966         }
 967
 968         lpi_data = buffer.pointer;
 969
 970         /* There must be at least 4 elements = 3 elements + 1 package */
 971         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 972             lpi_data->package.count < 4) {
 973                 pr_debug("not enough elements in _LPI\n");
 974                 ret = -ENODATA;
 975                 goto end;
 976         }
 977
 978         pkg_count = lpi_data->package.elements[2].integer.value;
 979
 980         /* Validate number of power states. */
 981         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 982                 pr_debug("count given by _LPI is not valid\n");
 983                 ret = -ENODATA;
 984                 goto end;
 985         }
 986
 987         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 988         if (!lpi_state) {
 989                 ret = -ENOMEM;
 990                 goto end;
 991         }
 992
 993         info->size = pkg_count;
 994         info->entries = lpi_state;
 995
 996         /* LPI States start at index 3 */
 997         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 998                 union acpi_object *element, *pkg_elem, *obj;
 999
1000                 element = &lpi_data->package.elements[loop];
1001                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1002                         continue;
1003
1004                 pkg_elem = element->package.elements;
1005
1006                 obj = pkg_elem + 6;
1007                 if (obj->type == ACPI_TYPE_BUFFER) {
1008                         struct acpi_power_register *reg;
1009
1010                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1011                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1012                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1013                                 continue;
1014
1015                         lpi_state->address = reg->address;
1016                         lpi_state->entry_method =
1017                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1018                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1019                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1020                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1021                         lpi_state->address = obj->integer.value;
1022                 } else {
1023                         continue;
1024                 }
1025
1026                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1027
1028                 obj = pkg_elem + 9;
1029                 if (obj->type == ACPI_TYPE_STRING)
1030                         strlcpy(lpi_state->desc, obj->string.pointer,
1031                                 ACPI_CX_DESC_LEN);
1032
1033                 lpi_state->index = state_idx;
1034                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1035                         pr_debug("No min. residency found, assuming 10 us\n");
1036                         lpi_state->min_residency = 10;
1037                 }
1038
1039                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1040                         pr_debug("No wakeup residency found, assuming 10 us\n");
1041                         lpi_state->wake_latency = 10;
1042                 }
1043
1044                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1045                         lpi_state->flags = 0;
1046
1047                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1048                         lpi_state->arch_flags = 0;
1049
1050                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1051                         lpi_state->res_cnt_freq = 1;
1052
1053                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1054                         lpi_state->enable_parent_state = 0;
1055         }
1056
1057         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1058 end:
1059         kfree(buffer.pointer);
1060         return ret;
1061 }
1062
1063 /*
1064  * flat_state_cnt - the number of composite LPI states after the process of flattening
1065  */
1066 static int flat_state_cnt;
1067
1068 /**
1069  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1070  *
1071  * @local: local LPI state
1072  * @parent: parent LPI state
1073  * @result: composite LPI state
1074  */
1075 static bool combine_lpi_states(struct acpi_lpi_state *local,
1076                                struct acpi_lpi_state *parent,
1077                                struct acpi_lpi_state *result)
1078 {
1079         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1080                 if (!parent->address) /* 0 means autopromotable */
1081                         return false;
1082                 result->address = local->address + parent->address;
1083         } else {
1084                 result->address = parent->address;
1085         }
1086
1087         result->min_residency = max(local->min_residency, parent->min_residency);
1088         result->wake_latency = local->wake_latency + parent->wake_latency;
1089         result->enable_parent_state = parent->enable_parent_state;
1090         result->entry_method = local->entry_method;
1091
1092         result->flags = parent->flags;
1093         result->arch_flags = parent->arch_flags;
1094         result->index = parent->index;
1095
1096         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1097         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1098         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1099         return true;
1100 }
1101
1102 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1103
1104 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1105                                   struct acpi_lpi_state *t)
1106 {
1107         curr_level->composite_states[curr_level->composite_states_size++] = t;
1108 }
1109
1110 static int flatten_lpi_states(struct acpi_processor *pr,
1111                               struct acpi_lpi_states_array *curr_level,
1112                               struct acpi_lpi_states_array *prev_level)
1113 {
1114         int i, j, state_count = curr_level->size;
1115         struct acpi_lpi_state *p, *t = curr_level->entries;
1116
1117         curr_level->composite_states_size = 0;
1118         for (j = 0; j < state_count; j++, t++) {
1119                 struct acpi_lpi_state *flpi;
1120
1121                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1122                         continue;
1123
1124                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1125                         pr_warn("Limiting number of LPI states to max (%d)\n",
1126                                 ACPI_PROCESSOR_MAX_POWER);
1127                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1128                         break;
1129                 }
1130
1131                 flpi = &pr->power.lpi_states[flat_state_cnt];
1132
1133                 if (!prev_level) { /* leaf/processor node */
1134                         memcpy(flpi, t, sizeof(*t));
1135                         stash_composite_state(curr_level, flpi);
1136                         flat_state_cnt++;
1137                         continue;
1138                 }
1139
1140                 for (i = 0; i < prev_level->composite_states_size; i++) {
1141                         p = prev_level->composite_states[i];
1142                         if (t->index <= p->enable_parent_state &&
1143                             combine_lpi_states(p, t, flpi)) {
1144                                 stash_composite_state(curr_level, flpi);
1145                                 flat_state_cnt++;
1146                                 flpi++;
1147                         }
1148                 }
1149         }
1150
1151         kfree(curr_level->entries);
1152         return 0;
1153 }
1154
1155 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1156 {
1157         int ret, i;
1158         acpi_status status;
1159         acpi_handle handle = pr->handle, pr_ahandle;
1160         struct acpi_device *d = NULL;
1161         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1162
1163         if (!osc_pc_lpi_support_confirmed)
1164                 return -EOPNOTSUPP;
1165
1166         if (!acpi_has_method(handle, "_LPI"))
1167                 return -EINVAL;
1168
1169         flat_state_cnt = 0;
1170         prev = &info[0];
1171         curr = &info[1];
1172         handle = pr->handle;
1173         ret = acpi_processor_evaluate_lpi(handle, prev);
1174         if (ret)
1175                 return ret;
1176         flatten_lpi_states(pr, prev, NULL);
1177
1178         status = acpi_get_parent(handle, &pr_ahandle);
1179         while (ACPI_SUCCESS(status)) {
1180                 acpi_bus_get_device(pr_ahandle, &d);
1181                 handle = pr_ahandle;
1182
1183                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1184                         break;
1185
1186                 /* can be optional ? */
1187                 if (!acpi_has_method(handle, "_LPI"))
1188                         break;
1189
1190                 ret = acpi_processor_evaluate_lpi(handle, curr);
1191                 if (ret)
1192                         break;
1193
1194                 /* flatten all the LPI states in this level of hierarchy */
1195                 flatten_lpi_states(pr, curr, prev);
1196
1197                 tmp = prev, prev = curr, curr = tmp;
1198
1199                 status = acpi_get_parent(handle, &pr_ahandle);
1200         }
1201
1202         pr->power.count = flat_state_cnt;
1203         /* reset the index after flattening */
1204         for (i = 0; i < pr->power.count; i++)
1205                 pr->power.lpi_states[i].index = i;
1206
1207         /* Tell driver that _LPI is supported. */
1208         pr->flags.has_lpi = 1;
1209         pr->flags.power = 1;
1210
1211         return 0;
1212 }
1213
1214 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1215 {
1216         return -ENODEV;
1217 }
1218
1219 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1220 {
1221         return -ENODEV;
1222 }
1223
1224 /**
1225  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1226  * @dev: the target CPU
1227  * @drv: cpuidle driver containing cpuidle state info
1228  * @index: index of target state
1229  *
1230  * Return: 0 for success or negative value for error
1231  */
1232 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1233                                struct cpuidle_driver *drv, int index)
1234 {
1235         struct acpi_processor *pr;
1236         struct acpi_lpi_state *lpi;
1237
1238         pr = __this_cpu_read(processors);
1239
1240         if (unlikely(!pr))
1241                 return -EINVAL;
1242
1243         lpi = &pr->power.lpi_states[index];
1244         if (lpi->entry_method == ACPI_CSTATE_FFH)
1245                 return acpi_processor_ffh_lpi_enter(lpi);
1246
1247         return -EINVAL;
1248 }
1249
1250 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1251 {
1252         int i;
1253         struct acpi_lpi_state *lpi;
1254         struct cpuidle_state *state;
1255         struct cpuidle_driver *drv = &acpi_idle_driver;
1256
1257         if (!pr->flags.has_lpi)
1258                 return -EOPNOTSUPP;
1259
1260         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1261                 lpi = &pr->power.lpi_states[i];
1262
1263                 state = &drv->states[i];
1264                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1265                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1266                 state->exit_latency = lpi->wake_latency;
1267                 state->target_residency = lpi->min_residency;
1268                 if (lpi->arch_flags)
1269                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1270                 state->enter = acpi_idle_lpi_enter;
1271                 drv->safe_state_index = i;
1272         }
1273
1274         drv->state_count = i;
1275
1276         return 0;
1277 }
1278
1279 /**
1280  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1281  * global state data i.e. idle routines
1282  *
1283  * @pr: the ACPI processor
1284  */
1285 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1286 {
1287         int i;
1288         struct cpuidle_driver *drv = &acpi_idle_driver;
1289
1290         if (!pr->flags.power_setup_done || !pr->flags.power)
1291                 return -EINVAL;
1292
1293         drv->safe_state_index = -1;
1294         for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1295                 drv->states[i].name[0] = '\0';
1296                 drv->states[i].desc[0] = '\0';
1297         }
1298
1299         if (pr->flags.has_lpi)
1300                 return acpi_processor_setup_lpi_states(pr);
1301
1302         return acpi_processor_setup_cstates(pr);
1303 }
1304
1305 /**
1306  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1307  * device i.e. per-cpu data
1308  *
1309  * @pr: the ACPI processor
1310  * @dev : the cpuidle device
1311  */
1312 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1313                                             struct cpuidle_device *dev)
1314 {
1315         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1316                 return -EINVAL;
1317
1318         dev->cpu = pr->id;
1319         if (pr->flags.has_lpi)
1320                 return acpi_processor_ffh_lpi_probe(pr->id);
1321
1322         return acpi_processor_setup_cpuidle_cx(pr, dev);
1323 }
1324
1325 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1326 {
1327         int ret;
1328
1329         ret = acpi_processor_get_lpi_info(pr);
1330         if (ret)
1331                 ret = acpi_processor_get_cstate_info(pr);
1332
1333         return ret;
1334 }
1335
1336 int acpi_processor_hotplug(struct acpi_processor *pr)
1337 {
1338         int ret = 0;
1339         struct cpuidle_device *dev;
1340
1341         if (disabled_by_idle_boot_param())
1342                 return 0;
1343
1344         if (!pr->flags.power_setup_done)
1345                 return -ENODEV;
1346
1347         dev = per_cpu(acpi_cpuidle_device, pr->id);
1348         cpuidle_pause_and_lock();
1349         cpuidle_disable_device(dev);
1350         ret = acpi_processor_get_power_info(pr);
1351         if (!ret && pr->flags.power) {
1352                 acpi_processor_setup_cpuidle_dev(pr, dev);
1353                 ret = cpuidle_enable_device(dev);
1354         }
1355         cpuidle_resume_and_unlock();
1356
1357         return ret;
1358 }
1359
1360 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1361 {
1362         int cpu;
1363         struct acpi_processor *_pr;
1364         struct cpuidle_device *dev;
1365
1366         if (disabled_by_idle_boot_param())
1367                 return 0;
1368
1369         if (!pr->flags.power_setup_done)
1370                 return -ENODEV;
1371
1372         /*
1373          * FIXME:  Design the ACPI notification to make it once per
1374          * system instead of once per-cpu.  This condition is a hack
1375          * to make the code that updates C-States be called once.
1376          */
1377
1378         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1379
1380                 /* Protect against cpu-hotplug */
1381                 get_online_cpus();
1382                 cpuidle_pause_and_lock();
1383
1384                 /* Disable all cpuidle devices */
1385                 for_each_online_cpu(cpu) {
1386                         _pr = per_cpu(processors, cpu);
1387                         if (!_pr || !_pr->flags.power_setup_done)
1388                                 continue;
1389                         dev = per_cpu(acpi_cpuidle_device, cpu);
1390                         cpuidle_disable_device(dev);
1391                 }
1392
1393                 /* Populate Updated C-state information */
1394                 acpi_processor_get_power_info(pr);
1395                 acpi_processor_setup_cpuidle_states(pr);
1396
1397                 /* Enable all cpuidle devices */
1398                 for_each_online_cpu(cpu) {
1399                         _pr = per_cpu(processors, cpu);
1400                         if (!_pr || !_pr->flags.power_setup_done)
1401                                 continue;
1402                         acpi_processor_get_power_info(_pr);
1403                         if (_pr->flags.power) {
1404                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1405                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1406                                 cpuidle_enable_device(dev);
1407                         }
1408                 }
1409                 cpuidle_resume_and_unlock();
1410                 put_online_cpus();
1411         }
1412
1413         return 0;
1414 }
1415
1416 static int acpi_processor_registered;
1417
1418 int acpi_processor_power_init(struct acpi_processor *pr)
1419 {
1420         int retval;
1421         struct cpuidle_device *dev;
1422
1423         if (disabled_by_idle_boot_param())
1424                 return 0;
1425
1426         acpi_processor_cstate_first_run_checks();
1427
1428         if (!acpi_processor_get_power_info(pr))
1429                 pr->flags.power_setup_done = 1;
1430
1431         /*
1432          * Install the idle handler if processor power management is supported.
1433          * Note that we use previously set idle handler will be used on
1434          * platforms that only support C1.
1435          */
1436         if (pr->flags.power) {
1437                 /* Register acpi_idle_driver if not already registered */
1438                 if (!acpi_processor_registered) {
1439                         acpi_processor_setup_cpuidle_states(pr);
1440                         retval = cpuidle_register_driver(&acpi_idle_driver);
1441                         if (retval)
1442                                 return retval;
1443                         pr_debug("%s registered with cpuidle\n",
1444                                  acpi_idle_driver.name);
1445                 }
1446
1447                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1448                 if (!dev)
1449                         return -ENOMEM;
1450                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1451
1452                 acpi_processor_setup_cpuidle_dev(pr, dev);
1453
1454                 /* Register per-cpu cpuidle_device. Cpuidle driver
1455                  * must already be registered before registering device
1456                  */
1457                 retval = cpuidle_register_device(dev);
1458                 if (retval) {
1459                         if (acpi_processor_registered == 0)
1460                                 cpuidle_unregister_driver(&acpi_idle_driver);
1461                         return retval;
1462                 }
1463                 acpi_processor_registered++;
1464         }
1465         return 0;
1466 }
1467
1468 int acpi_processor_power_exit(struct acpi_processor *pr)
1469 {
1470         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1471
1472         if (disabled_by_idle_boot_param())
1473                 return 0;
1474
1475         if (pr->flags.power) {
1476                 cpuidle_unregister_device(dev);
1477                 acpi_processor_registered--;
1478                 if (acpi_processor_registered == 0)
1479                         cpuidle_unregister_driver(&acpi_idle_driver);
1480         }
1481
1482         pr->flags.power_setup_done = 0;
1483         return 0;
1484 }