drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26 #define pr_fmt(fmt) "ACPI: " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <linux/sched.h>       /* need_resched() */
  32 #include <linux/tick.h>
  33 #include <linux/cpuidle.h>
  34 #include <linux/cpu.h>
  35 #include <acpi/processor.h>
  36
  37 /*
  38  * Include the apic definitions for x86 to have the APIC timer related defines
  39  * available also for UP (on SMP it gets magically included via linux/smp.h).
  40  * asm/acpi.h is not an option, as it would require more include magic. Also
  41  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  42  */
  43 #ifdef CONFIG_X86
  44 #include <asm/apic.h>
  45 #endif
  46
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("processor_idle");
  50
  51 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  52
  53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  54 module_param(max_cstate, uint, 0000);
  55 static unsigned int nocst __read_mostly;
  56 module_param(nocst, uint, 0000);
  57 static int bm_check_disable __read_mostly;
  58 module_param(bm_check_disable, uint, 0000);
  59
  60 static unsigned int latency_factor __read_mostly = 2;
  61 module_param(latency_factor, uint, 0644);
  62
  63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  64
  65 struct cpuidle_driver acpi_idle_driver = {
  66         .name =         "acpi_idle",
  67         .owner =        THIS_MODULE,
  68 };
  69
  70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  71 static
  72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  73
  74 static int disabled_by_idle_boot_param(void)
  75 {
  76         return boot_option_idle_override == IDLE_POLL ||
  77                 boot_option_idle_override == IDLE_HALT;
  78 }
  79
  80 /*
  81  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  82  * For now disable this. Probably a bug somewhere else.
  83  *
  84  * To skip this limit, boot/load with a large max_cstate limit.
  85  */
  86 static int set_max_cstate(const struct dmi_system_id *id)
  87 {
  88         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  89                 return 0;
  90
  91         pr_notice("%s detected - limiting to C%ld max_cstate."
  92                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  93                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  94
  95         max_cstate = (long)id->driver_data;
  96
  97         return 0;
  98 }
  99
 100 static const struct dmi_system_id processor_power_dmi_table[] = {
 101         { set_max_cstate, "Clevo 5600D", {
 102           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 103           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 104          (void *)2},
 105         { set_max_cstate, "Pavilion zv5000", {
 106           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 107           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 108          (void *)1},
 109         { set_max_cstate, "Asus L8400B", {
 110           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 111           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 112          (void *)1},
 113         {},
 114 };
 115
 116
 117 /*
 118  * Callers should disable interrupts before the call and enable
 119  * interrupts after return.
 120  */
 121 static void __cpuidle acpi_safe_halt(void)
 122 {
 123         if (!tif_need_resched()) {
 124                 safe_halt();
 125                 local_irq_disable();
 126         }
 127 }
 128
 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 130
 131 /*
 132  * Some BIOS implementations switch to C3 in the published C2 state.
 133  * This seems to be a common problem on AMD boxen, but other vendors
 134  * are affected too. We pick the most conservative approach: we assume
 135  * that the local APIC stops in both C2 and C3.
 136  */
 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 138                                    struct acpi_processor_cx *cx)
 139 {
 140         struct acpi_processor_power *pwr = &pr->power;
 141         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 142
 143         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 144                 return;
 145
 146         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 147                 type = ACPI_STATE_C1;
 148
 149         /*
 150          * Check, if one of the previous states already marked the lapic
 151          * unstable
 152          */
 153         if (pwr->timer_broadcast_on_state < state)
 154                 return;
 155
 156         if (cx->type >= type)
 157                 pr->power.timer_broadcast_on_state = state;
 158 }
 159
 160 static void __lapic_timer_propagate_broadcast(void *arg)
 161 {
 162         struct acpi_processor *pr = (struct acpi_processor *) arg;
 163
 164         if (pr->power.timer_broadcast_on_state < INT_MAX)
 165                 tick_broadcast_enable();
 166         else
 167                 tick_broadcast_disable();
 168 }
 169
 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 171 {
 172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 173                                  (void *)pr, 1);
 174 }
 175
 176 /* Power(C) State timer broadcast control */
 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 178                                        struct acpi_processor_cx *cx,
 179                                        int broadcast)
 180 {
 181         int state = cx - pr->power.states;
 182
 183         if (state >= pr->power.timer_broadcast_on_state) {
 184                 if (broadcast)
 185                         tick_broadcast_enter();
 186                 else
 187                         tick_broadcast_exit();
 188         }
 189 }
 190
 191 #else
 192
 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 194                                    struct acpi_processor_cx *cstate) { }
 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 197                                        struct acpi_processor_cx *cx,
 198                                        int broadcast)
 199 {
 200 }
 201
 202 #endif
 203
 204 #if defined(CONFIG_X86)
 205 static void tsc_check_state(int state)
 206 {
 207         switch (boot_cpu_data.x86_vendor) {
 208         case X86_VENDOR_AMD:
 209         case X86_VENDOR_INTEL:
 210                 /*
 211                  * AMD Fam10h TSC will tick in all
 212                  * C/P/S0/S1 states when this bit is set.
 213                  */
 214                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 215                         return;
 216
 217                 /*FALL THROUGH*/
 218         default:
 219                 /* TSC could halt in idle, so notify users */
 220                 if (state > ACPI_STATE_C1)
 221                         mark_tsc_unstable("TSC halts in idle");
 222         }
 223 }
 224 #else
 225 static void tsc_check_state(int state) { return; }
 226 #endif
 227
 228 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 229 {
 230
 231         if (!pr->pblk)
 232                 return -ENODEV;
 233
 234         /* if info is obtained from pblk/fadt, type equals state */
 235         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 236         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 237
 238 #ifndef CONFIG_HOTPLUG_CPU
 239         /*
 240          * Check for P_LVL2_UP flag before entering C2 and above on
 241          * an SMP system.
 242          */
 243         if ((num_online_cpus() > 1) &&
 244             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 245                 return -ENODEV;
 246 #endif
 247
 248         /* determine C2 and C3 address from pblk */
 249         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 250         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 251
 252         /* determine latencies from FADT */
 253         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 254         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 255
 256         /*
 257          * FADT specified C2 latency must be less than or equal to
 258          * 100 microseconds.
 259          */
 260         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 261                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 262                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 263                 /* invalidate C2 */
 264                 pr->power.states[ACPI_STATE_C2].address = 0;
 265         }
 266
 267         /*
 268          * FADT supplied C3 latency must be less than or equal to
 269          * 1000 microseconds.
 270          */
 271         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 272                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 273                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 274                 /* invalidate C3 */
 275                 pr->power.states[ACPI_STATE_C3].address = 0;
 276         }
 277
 278         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 279                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 280                           pr->power.states[ACPI_STATE_C2].address,
 281                           pr->power.states[ACPI_STATE_C3].address));
 282
 283         return 0;
 284 }
 285
 286 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 287 {
 288         if (!pr->power.states[ACPI_STATE_C1].valid) {
 289                 /* set the first C-State to C1 */
 290                 /* all processors need to support C1 */
 291                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 292                 pr->power.states[ACPI_STATE_C1].valid = 1;
 293                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 294
 295                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 296                          ACPI_CX_DESC_LEN, "ACPI HLT");
 297         }
 298         /* the C0 state only exists as a filler in our array */
 299         pr->power.states[ACPI_STATE_C0].valid = 1;
 300         return 0;
 301 }
 302
 303 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 304 {
 305         acpi_status status;
 306         u64 count;
 307         int current_count;
 308         int i, ret = 0;
 309         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 310         union acpi_object *cst;
 311
 312         if (nocst)
 313                 return -ENODEV;
 314
 315         current_count = 0;
 316
 317         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 318         if (ACPI_FAILURE(status)) {
 319                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 320                 return -ENODEV;
 321         }
 322
 323         cst = buffer.pointer;
 324
 325         /* There must be at least 2 elements */
 326         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 327                 pr_err("not enough elements in _CST\n");
 328                 ret = -EFAULT;
 329                 goto end;
 330         }
 331
 332         count = cst->package.elements[0].integer.value;
 333
 334         /* Validate number of power states. */
 335         if (count < 1 || count != cst->package.count - 1) {
 336                 pr_err("count given by _CST is not valid\n");
 337                 ret = -EFAULT;
 338                 goto end;
 339         }
 340
 341         /* Tell driver that at least _CST is supported. */
 342         pr->flags.has_cst = 1;
 343
 344         for (i = 1; i <= count; i++) {
 345                 union acpi_object *element;
 346                 union acpi_object *obj;
 347                 struct acpi_power_register *reg;
 348                 struct acpi_processor_cx cx;
 349
 350                 memset(&cx, 0, sizeof(cx));
 351
 352                 element = &(cst->package.elements[i]);
 353                 if (element->type != ACPI_TYPE_PACKAGE)
 354                         continue;
 355
 356                 if (element->package.count != 4)
 357                         continue;
 358
 359                 obj = &(element->package.elements[0]);
 360
 361                 if (obj->type != ACPI_TYPE_BUFFER)
 362                         continue;
 363
 364                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 365
 366                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 367                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 368                         continue;
 369
 370                 /* There should be an easy way to extract an integer... */
 371                 obj = &(element->package.elements[1]);
 372                 if (obj->type != ACPI_TYPE_INTEGER)
 373                         continue;
 374
 375                 cx.type = obj->integer.value;
 376                 /*
 377                  * Some buggy BIOSes won't list C1 in _CST -
 378                  * Let acpi_processor_get_power_info_default() handle them later
 379                  */
 380                 if (i == 1 && cx.type != ACPI_STATE_C1)
 381                         current_count++;
 382
 383                 cx.address = reg->address;
 384                 cx.index = current_count + 1;
 385
 386                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 387                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 388                         if (acpi_processor_ffh_cstate_probe
 389                                         (pr->id, &cx, reg) == 0) {
 390                                 cx.entry_method = ACPI_CSTATE_FFH;
 391                         } else if (cx.type == ACPI_STATE_C1) {
 392                                 /*
 393                                  * C1 is a special case where FIXED_HARDWARE
 394                                  * can be handled in non-MWAIT way as well.
 395                                  * In that case, save this _CST entry info.
 396                                  * Otherwise, ignore this info and continue.
 397                                  */
 398                                 cx.entry_method = ACPI_CSTATE_HALT;
 399                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 400                         } else {
 401                                 continue;
 402                         }
 403                         if (cx.type == ACPI_STATE_C1 &&
 404                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 405                                 /*
 406                                  * In most cases the C1 space_id obtained from
 407                                  * _CST object is FIXED_HARDWARE access mode.
 408                                  * But when the option of idle=halt is added,
 409                                  * the entry_method type should be changed from
 410                                  * CSTATE_FFH to CSTATE_HALT.
 411                                  * When the option of idle=nomwait is added,
 412                                  * the C1 entry_method type should be
 413                                  * CSTATE_HALT.
 414                                  */
 415                                 cx.entry_method = ACPI_CSTATE_HALT;
 416                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 417                         }
 418                 } else {
 419                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 420                                  cx.address);
 421                 }
 422
 423                 if (cx.type == ACPI_STATE_C1) {
 424                         cx.valid = 1;
 425                 }
 426
 427                 obj = &(element->package.elements[2]);
 428                 if (obj->type != ACPI_TYPE_INTEGER)
 429                         continue;
 430
 431                 cx.latency = obj->integer.value;
 432
 433                 obj = &(element->package.elements[3]);
 434                 if (obj->type != ACPI_TYPE_INTEGER)
 435                         continue;
 436
 437                 current_count++;
 438                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 439
 440                 /*
 441                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 442                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 443                  */
 444                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 445                         pr_warn("Limiting number of power states to max (%d)\n",
 446                                 ACPI_PROCESSOR_MAX_POWER);
 447                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 448                         break;
 449                 }
 450         }
 451
 452         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 453                           current_count));
 454
 455         /* Validate number of power states discovered */
 456         if (current_count < 2)
 457                 ret = -EFAULT;
 458
 459       end:
 460         kfree(buffer.pointer);
 461
 462         return ret;
 463 }
 464
 465 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 466                                            struct acpi_processor_cx *cx)
 467 {
 468         static int bm_check_flag = -1;
 469         static int bm_control_flag = -1;
 470
 471
 472         if (!cx->address)
 473                 return;
 474
 475         /*
 476          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 477          * DMA transfers are used by any ISA device to avoid livelock.
 478          * Note that we could disable Type-F DMA (as recommended by
 479          * the erratum), but this is known to disrupt certain ISA
 480          * devices thus we take the conservative approach.
 481          */
 482         else if (errata.piix4.fdma) {
 483                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 484                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 485                 return;
 486         }
 487
 488         /* All the logic here assumes flags.bm_check is same across all CPUs */
 489         if (bm_check_flag == -1) {
 490                 /* Determine whether bm_check is needed based on CPU  */
 491                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 492                 bm_check_flag = pr->flags.bm_check;
 493                 bm_control_flag = pr->flags.bm_control;
 494         } else {
 495                 pr->flags.bm_check = bm_check_flag;
 496                 pr->flags.bm_control = bm_control_flag;
 497         }
 498
 499         if (pr->flags.bm_check) {
 500                 if (!pr->flags.bm_control) {
 501                         if (pr->flags.has_cst != 1) {
 502                                 /* bus mastering control is necessary */
 503                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 504                                         "C3 support requires BM control\n"));
 505                                 return;
 506                         } else {
 507                                 /* Here we enter C3 without bus mastering */
 508                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 509                                         "C3 support without BM control\n"));
 510                         }
 511                 }
 512         } else {
 513                 /*
 514                  * WBINVD should be set in fadt, for C3 state to be
 515                  * supported on when bm_check is not required.
 516                  */
 517                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 518                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 519                                           "Cache invalidation should work properly"
 520                                           " for C3 to be enabled on SMP systems\n"));
 521                         return;
 522                 }
 523         }
 524
 525         /*
 526          * Otherwise we've met all of our C3 requirements.
 527          * Normalize the C3 latency to expidite policy.  Enable
 528          * checking of bus mastering status (bm_check) so we can
 529          * use this in our C3 policy
 530          */
 531         cx->valid = 1;
 532
 533         /*
 534          * On older chipsets, BM_RLD needs to be set
 535          * in order for Bus Master activity to wake the
 536          * system from C3.  Newer chipsets handle DMA
 537          * during C3 automatically and BM_RLD is a NOP.
 538          * In either case, the proper way to
 539          * handle BM_RLD is to set it and leave it set.
 540          */
 541         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 542
 543         return;
 544 }
 545
 546 static int acpi_processor_power_verify(struct acpi_processor *pr)
 547 {
 548         unsigned int i;
 549         unsigned int working = 0;
 550
 551         pr->power.timer_broadcast_on_state = INT_MAX;
 552
 553         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 554                 struct acpi_processor_cx *cx = &pr->power.states[i];
 555
 556                 switch (cx->type) {
 557                 case ACPI_STATE_C1:
 558                         cx->valid = 1;
 559                         break;
 560
 561                 case ACPI_STATE_C2:
 562                         if (!cx->address)
 563                                 break;
 564                         cx->valid = 1;
 565                         break;
 566
 567                 case ACPI_STATE_C3:
 568                         acpi_processor_power_verify_c3(pr, cx);
 569                         break;
 570                 }
 571                 if (!cx->valid)
 572                         continue;
 573
 574                 lapic_timer_check_state(i, pr, cx);
 575                 tsc_check_state(cx->type);
 576                 working++;
 577         }
 578
 579         lapic_timer_propagate_broadcast(pr);
 580
 581         return (working);
 582 }
 583
 584 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 585 {
 586         unsigned int i;
 587         int result;
 588
 589
 590         /* NOTE: the idle thread may not be running while calling
 591          * this function */
 592
 593         /* Zero initialize all the C-states info. */
 594         memset(pr->power.states, 0, sizeof(pr->power.states));
 595
 596         result = acpi_processor_get_power_info_cst(pr);
 597         if (result == -ENODEV)
 598                 result = acpi_processor_get_power_info_fadt(pr);
 599
 600         if (result)
 601                 return result;
 602
 603         acpi_processor_get_power_info_default(pr);
 604
 605         pr->power.count = acpi_processor_power_verify(pr);
 606
 607         /*
 608          * if one state of type C2 or C3 is available, mark this
 609          * CPU as being "idle manageable"
 610          */
 611         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 612                 if (pr->power.states[i].valid) {
 613                         pr->power.count = i;
 614                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 615                                 pr->flags.power = 1;
 616                 }
 617         }
 618
 619         return 0;
 620 }
 621
 622 /**
 623  * acpi_idle_bm_check - checks if bus master activity was detected
 624  */
 625 static int acpi_idle_bm_check(void)
 626 {
 627         u32 bm_status = 0;
 628
 629         if (bm_check_disable)
 630                 return 0;
 631
 632         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 633         if (bm_status)
 634                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 635         /*
 636          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 637          * the true state of bus mastering activity; forcing us to
 638          * manually check the BMIDEA bit of each IDE channel.
 639          */
 640         else if (errata.piix4.bmisx) {
 641                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 642                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 643                         bm_status = 1;
 644         }
 645         return bm_status;
 646 }
 647
 648 /**
 649  * acpi_idle_do_entry - enter idle state using the appropriate method
 650  * @cx: cstate data
 651  *
 652  * Caller disables interrupt before call and enables interrupt after return.
 653  */
 654 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 655 {
 656         if (cx->entry_method == ACPI_CSTATE_FFH) {
 657                 /* Call into architectural FFH based C-state */
 658                 acpi_processor_ffh_cstate_enter(cx);
 659         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 660                 acpi_safe_halt();
 661         } else {
 662                 /* IO port based C-state */
 663                 inb(cx->address);
 664                 /* Dummy wait op - must do something useless after P_LVL2 read
 665                    because chipsets cannot guarantee that STPCLK# signal
 666                    gets asserted in time to freeze execution properly. */
 667                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 668         }
 669 }
 670
 671 /**
 672  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 673  * @dev: the target CPU
 674  * @index: the index of suggested state
 675  */
 676 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 677 {
 678         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 679
 680         ACPI_FLUSH_CPU_CACHE();
 681
 682         while (1) {
 683
 684                 if (cx->entry_method == ACPI_CSTATE_HALT)
 685                         safe_halt();
 686                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 687                         inb(cx->address);
 688                         /* See comment in acpi_idle_do_entry() */
 689                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 690                 } else
 691                         return -ENODEV;
 692         }
 693
 694         /* Never reached */
 695         return 0;
 696 }
 697
 698 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 699 {
 700         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 701                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 702 }
 703
 704 static int c3_cpu_count;
 705 static DEFINE_RAW_SPINLOCK(c3_lock);
 706
 707 /**
 708  * acpi_idle_enter_bm - enters C3 with proper BM handling
 709  * @pr: Target processor
 710  * @cx: Target state context
 711  * @timer_bc: Whether or not to change timer mode to broadcast
 712  */
 713 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 714                                struct acpi_processor_cx *cx, bool timer_bc)
 715 {
 716         acpi_unlazy_tlb(smp_processor_id());
 717
 718         /*
 719          * Must be done before busmaster disable as we might need to
 720          * access HPET !
 721          */
 722         if (timer_bc)
 723                 lapic_timer_state_broadcast(pr, cx, 1);
 724
 725         /*
 726          * disable bus master
 727          * bm_check implies we need ARB_DIS
 728          * bm_control implies whether we can do ARB_DIS
 729          *
 730          * That leaves a case where bm_check is set and bm_control is
 731          * not set. In that case we cannot do much, we enter C3
 732          * without doing anything.
 733          */
 734         if (pr->flags.bm_control) {
 735                 raw_spin_lock(&c3_lock);
 736                 c3_cpu_count++;
 737                 /* Disable bus master arbitration when all CPUs are in C3 */
 738                 if (c3_cpu_count == num_online_cpus())
 739                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 740                 raw_spin_unlock(&c3_lock);
 741         }
 742
 743         acpi_idle_do_entry(cx);
 744
 745         /* Re-enable bus master arbitration */
 746         if (pr->flags.bm_control) {
 747                 raw_spin_lock(&c3_lock);
 748                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 749                 c3_cpu_count--;
 750                 raw_spin_unlock(&c3_lock);
 751         }
 752
 753         if (timer_bc)
 754                 lapic_timer_state_broadcast(pr, cx, 0);
 755 }
 756
 757 static int acpi_idle_enter(struct cpuidle_device *dev,
 758                            struct cpuidle_driver *drv, int index)
 759 {
 760         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 761         struct acpi_processor *pr;
 762
 763         pr = __this_cpu_read(processors);
 764         if (unlikely(!pr))
 765                 return -EINVAL;
 766
 767         if (cx->type != ACPI_STATE_C1) {
 768                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 769                         index = ACPI_IDLE_STATE_START;
 770                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 771                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 772                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 773                                 acpi_idle_enter_bm(pr, cx, true);
 774                                 return index;
 775                         } else if (drv->safe_state_index >= 0) {
 776                                 index = drv->safe_state_index;
 777                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 778                         } else {
 779                                 acpi_safe_halt();
 780                                 return -EBUSY;
 781                         }
 782                 }
 783         }
 784
 785         lapic_timer_state_broadcast(pr, cx, 1);
 786
 787         if (cx->type == ACPI_STATE_C3)
 788                 ACPI_FLUSH_CPU_CACHE();
 789
 790         acpi_idle_do_entry(cx);
 791
 792         lapic_timer_state_broadcast(pr, cx, 0);
 793
 794         return index;
 795 }
 796
 797 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 798                                    struct cpuidle_driver *drv, int index)
 799 {
 800         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 801
 802         if (cx->type == ACPI_STATE_C3) {
 803                 struct acpi_processor *pr = __this_cpu_read(processors);
 804
 805                 if (unlikely(!pr))
 806                         return;
 807
 808                 if (pr->flags.bm_check) {
 809                         acpi_idle_enter_bm(pr, cx, false);
 810                         return;
 811                 } else {
 812                         ACPI_FLUSH_CPU_CACHE();
 813                 }
 814         }
 815         acpi_idle_do_entry(cx);
 816 }
 817
 818 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 819                                            struct cpuidle_device *dev)
 820 {
 821         int i, count = ACPI_IDLE_STATE_START;
 822         struct acpi_processor_cx *cx;
 823
 824         if (max_cstate == 0)
 825                 max_cstate = 1;
 826
 827         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 828                 cx = &pr->power.states[i];
 829
 830                 if (!cx->valid)
 831                         continue;
 832
 833                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 834
 835                 count++;
 836                 if (count == CPUIDLE_STATE_MAX)
 837                         break;
 838         }
 839
 840         if (!count)
 841                 return -EINVAL;
 842
 843         return 0;
 844 }
 845
 846 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 847 {
 848         int i, count;
 849         struct acpi_processor_cx *cx;
 850         struct cpuidle_state *state;
 851         struct cpuidle_driver *drv = &acpi_idle_driver;
 852
 853         if (max_cstate == 0)
 854                 max_cstate = 1;
 855
 856         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 857                 cpuidle_poll_state_init(drv);
 858                 count = 1;
 859         } else {
 860                 count = 0;
 861         }
 862
 863         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 864                 cx = &pr->power.states[i];
 865
 866                 if (!cx->valid)
 867                         continue;
 868
 869                 state = &drv->states[count];
 870                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 871                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 872                 state->exit_latency = cx->latency;
 873                 state->target_residency = cx->latency * latency_factor;
 874                 state->enter = acpi_idle_enter;
 875
 876                 state->flags = 0;
 877                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 878                         state->enter_dead = acpi_idle_play_dead;
 879                         drv->safe_state_index = count;
 880                 }
 881                 /*
 882                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 883                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 884                  * particularly interesting from the suspend-to-idle angle, so
 885                  * avoid C1 and the situations in which we may need to fall back
 886                  * to it altogether.
 887                  */
 888                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 889                         state->enter_s2idle = acpi_idle_enter_s2idle;
 890
 891                 count++;
 892                 if (count == CPUIDLE_STATE_MAX)
 893                         break;
 894         }
 895
 896         drv->state_count = count;
 897
 898         if (!count)
 899                 return -EINVAL;
 900
 901         return 0;
 902 }
 903
 904 static inline void acpi_processor_cstate_first_run_checks(void)
 905 {
 906         acpi_status status;
 907         static int first_run;
 908
 909         if (first_run)
 910                 return;
 911         dmi_check_system(processor_power_dmi_table);
 912         max_cstate = acpi_processor_cstate_check(max_cstate);
 913         if (max_cstate < ACPI_C_STATES_MAX)
 914                 pr_notice("ACPI: processor limited to max C-state %d\n",
 915                           max_cstate);
 916         first_run++;
 917
 918         if (acpi_gbl_FADT.cst_control && !nocst) {
 919                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 920                                             acpi_gbl_FADT.cst_control, 8);
 921                 if (ACPI_FAILURE(status))
 922                         ACPI_EXCEPTION((AE_INFO, status,
 923                                         "Notifying BIOS of _CST ability failed"));
 924         }
 925 }
 926 #else
 927
 928 static inline int disabled_by_idle_boot_param(void) { return 0; }
 929 static inline void acpi_processor_cstate_first_run_checks(void) { }
 930 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 931 {
 932         return -ENODEV;
 933 }
 934
 935 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 936                                            struct cpuidle_device *dev)
 937 {
 938         return -EINVAL;
 939 }
 940
 941 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 942 {
 943         return -EINVAL;
 944 }
 945
 946 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 947
 948 struct acpi_lpi_states_array {
 949         unsigned int size;
 950         unsigned int composite_states_size;
 951         struct acpi_lpi_state *entries;
 952         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 953 };
 954
 955 static int obj_get_integer(union acpi_object *obj, u32 *value)
 956 {
 957         if (obj->type != ACPI_TYPE_INTEGER)
 958                 return -EINVAL;
 959
 960         *value = obj->integer.value;
 961         return 0;
 962 }
 963
 964 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 965                                        struct acpi_lpi_states_array *info)
 966 {
 967         acpi_status status;
 968         int ret = 0;
 969         int pkg_count, state_idx = 1, loop;
 970         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 971         union acpi_object *lpi_data;
 972         struct acpi_lpi_state *lpi_state;
 973
 974         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 975         if (ACPI_FAILURE(status)) {
 976                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 977                 return -ENODEV;
 978         }
 979
 980         lpi_data = buffer.pointer;
 981
 982         /* There must be at least 4 elements = 3 elements + 1 package */
 983         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 984             lpi_data->package.count < 4) {
 985                 pr_debug("not enough elements in _LPI\n");
 986                 ret = -ENODATA;
 987                 goto end;
 988         }
 989
 990         pkg_count = lpi_data->package.elements[2].integer.value;
 991
 992         /* Validate number of power states. */
 993         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 994                 pr_debug("count given by _LPI is not valid\n");
 995                 ret = -ENODATA;
 996                 goto end;
 997         }
 998
 999         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1000         if (!lpi_state) {
1001                 ret = -ENOMEM;
1002                 goto end;
1003         }
1004
1005         info->size = pkg_count;
1006         info->entries = lpi_state;
1007
1008         /* LPI States start at index 3 */
1009         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1010                 union acpi_object *element, *pkg_elem, *obj;
1011
1012                 element = &lpi_data->package.elements[loop];
1013                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1014                         continue;
1015
1016                 pkg_elem = element->package.elements;
1017
1018                 obj = pkg_elem + 6;
1019                 if (obj->type == ACPI_TYPE_BUFFER) {
1020                         struct acpi_power_register *reg;
1021
1022                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1023                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1024                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1025                                 continue;
1026
1027                         lpi_state->address = reg->address;
1028                         lpi_state->entry_method =
1029                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1030                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1031                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1032                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1033                         lpi_state->address = obj->integer.value;
1034                 } else {
1035                         continue;
1036                 }
1037
1038                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1039
1040                 obj = pkg_elem + 9;
1041                 if (obj->type == ACPI_TYPE_STRING)
1042                         strlcpy(lpi_state->desc, obj->string.pointer,
1043                                 ACPI_CX_DESC_LEN);
1044
1045                 lpi_state->index = state_idx;
1046                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1047                         pr_debug("No min. residency found, assuming 10 us\n");
1048                         lpi_state->min_residency = 10;
1049                 }
1050
1051                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1052                         pr_debug("No wakeup residency found, assuming 10 us\n");
1053                         lpi_state->wake_latency = 10;
1054                 }
1055
1056                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1057                         lpi_state->flags = 0;
1058
1059                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1060                         lpi_state->arch_flags = 0;
1061
1062                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1063                         lpi_state->res_cnt_freq = 1;
1064
1065                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1066                         lpi_state->enable_parent_state = 0;
1067         }
1068
1069         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1070 end:
1071         kfree(buffer.pointer);
1072         return ret;
1073 }
1074
1075 /*
1076  * flat_state_cnt - the number of composite LPI states after the process of flattening
1077  */
1078 static int flat_state_cnt;
1079
1080 /**
1081  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1082  *
1083  * @local: local LPI state
1084  * @parent: parent LPI state
1085  * @result: composite LPI state
1086  */
1087 static bool combine_lpi_states(struct acpi_lpi_state *local,
1088                                struct acpi_lpi_state *parent,
1089                                struct acpi_lpi_state *result)
1090 {
1091         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1092                 if (!parent->address) /* 0 means autopromotable */
1093                         return false;
1094                 result->address = local->address + parent->address;
1095         } else {
1096                 result->address = parent->address;
1097         }
1098
1099         result->min_residency = max(local->min_residency, parent->min_residency);
1100         result->wake_latency = local->wake_latency + parent->wake_latency;
1101         result->enable_parent_state = parent->enable_parent_state;
1102         result->entry_method = local->entry_method;
1103
1104         result->flags = parent->flags;
1105         result->arch_flags = parent->arch_flags;
1106         result->index = parent->index;
1107
1108         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1109         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1110         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1111         return true;
1112 }
1113
1114 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1115
1116 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1117                                   struct acpi_lpi_state *t)
1118 {
1119         curr_level->composite_states[curr_level->composite_states_size++] = t;
1120 }
1121
1122 static int flatten_lpi_states(struct acpi_processor *pr,
1123                               struct acpi_lpi_states_array *curr_level,
1124                               struct acpi_lpi_states_array *prev_level)
1125 {
1126         int i, j, state_count = curr_level->size;
1127         struct acpi_lpi_state *p, *t = curr_level->entries;
1128
1129         curr_level->composite_states_size = 0;
1130         for (j = 0; j < state_count; j++, t++) {
1131                 struct acpi_lpi_state *flpi;
1132
1133                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1134                         continue;
1135
1136                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1137                         pr_warn("Limiting number of LPI states to max (%d)\n",
1138                                 ACPI_PROCESSOR_MAX_POWER);
1139                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1140                         break;
1141                 }
1142
1143                 flpi = &pr->power.lpi_states[flat_state_cnt];
1144
1145                 if (!prev_level) { /* leaf/processor node */
1146                         memcpy(flpi, t, sizeof(*t));
1147                         stash_composite_state(curr_level, flpi);
1148                         flat_state_cnt++;
1149                         continue;
1150                 }
1151
1152                 for (i = 0; i < prev_level->composite_states_size; i++) {
1153                         p = prev_level->composite_states[i];
1154                         if (t->index <= p->enable_parent_state &&
1155                             combine_lpi_states(p, t, flpi)) {
1156                                 stash_composite_state(curr_level, flpi);
1157                                 flat_state_cnt++;
1158                                 flpi++;
1159                         }
1160                 }
1161         }
1162
1163         kfree(curr_level->entries);
1164         return 0;
1165 }
1166
1167 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1168 {
1169         int ret, i;
1170         acpi_status status;
1171         acpi_handle handle = pr->handle, pr_ahandle;
1172         struct acpi_device *d = NULL;
1173         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1174
1175         if (!osc_pc_lpi_support_confirmed)
1176                 return -EOPNOTSUPP;
1177
1178         if (!acpi_has_method(handle, "_LPI"))
1179                 return -EINVAL;
1180
1181         flat_state_cnt = 0;
1182         prev = &info[0];
1183         curr = &info[1];
1184         handle = pr->handle;
1185         ret = acpi_processor_evaluate_lpi(handle, prev);
1186         if (ret)
1187                 return ret;
1188         flatten_lpi_states(pr, prev, NULL);
1189
1190         status = acpi_get_parent(handle, &pr_ahandle);
1191         while (ACPI_SUCCESS(status)) {
1192                 acpi_bus_get_device(pr_ahandle, &d);
1193                 handle = pr_ahandle;
1194
1195                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1196                         break;
1197
1198                 /* can be optional ? */
1199                 if (!acpi_has_method(handle, "_LPI"))
1200                         break;
1201
1202                 ret = acpi_processor_evaluate_lpi(handle, curr);
1203                 if (ret)
1204                         break;
1205
1206                 /* flatten all the LPI states in this level of hierarchy */
1207                 flatten_lpi_states(pr, curr, prev);
1208
1209                 tmp = prev, prev = curr, curr = tmp;
1210
1211                 status = acpi_get_parent(handle, &pr_ahandle);
1212         }
1213
1214         pr->power.count = flat_state_cnt;
1215         /* reset the index after flattening */
1216         for (i = 0; i < pr->power.count; i++)
1217                 pr->power.lpi_states[i].index = i;
1218
1219         /* Tell driver that _LPI is supported. */
1220         pr->flags.has_lpi = 1;
1221         pr->flags.power = 1;
1222
1223         return 0;
1224 }
1225
1226 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1227 {
1228         return -ENODEV;
1229 }
1230
1231 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1232 {
1233         return -ENODEV;
1234 }
1235
1236 /**
1237  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1238  * @dev: the target CPU
1239  * @drv: cpuidle driver containing cpuidle state info
1240  * @index: index of target state
1241  *
1242  * Return: 0 for success or negative value for error
1243  */
1244 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1245                                struct cpuidle_driver *drv, int index)
1246 {
1247         struct acpi_processor *pr;
1248         struct acpi_lpi_state *lpi;
1249
1250         pr = __this_cpu_read(processors);
1251
1252         if (unlikely(!pr))
1253                 return -EINVAL;
1254
1255         lpi = &pr->power.lpi_states[index];
1256         if (lpi->entry_method == ACPI_CSTATE_FFH)
1257                 return acpi_processor_ffh_lpi_enter(lpi);
1258
1259         return -EINVAL;
1260 }
1261
1262 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1263 {
1264         int i;
1265         struct acpi_lpi_state *lpi;
1266         struct cpuidle_state *state;
1267         struct cpuidle_driver *drv = &acpi_idle_driver;
1268
1269         if (!pr->flags.has_lpi)
1270                 return -EOPNOTSUPP;
1271
1272         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1273                 lpi = &pr->power.lpi_states[i];
1274
1275                 state = &drv->states[i];
1276                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1277                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1278                 state->exit_latency = lpi->wake_latency;
1279                 state->target_residency = lpi->min_residency;
1280                 if (lpi->arch_flags)
1281                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1282                 state->enter = acpi_idle_lpi_enter;
1283                 drv->safe_state_index = i;
1284         }
1285
1286         drv->state_count = i;
1287
1288         return 0;
1289 }
1290
1291 /**
1292  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1293  * global state data i.e. idle routines
1294  *
1295  * @pr: the ACPI processor
1296  */
1297 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1298 {
1299         int i;
1300         struct cpuidle_driver *drv = &acpi_idle_driver;
1301
1302         if (!pr->flags.power_setup_done || !pr->flags.power)
1303                 return -EINVAL;
1304
1305         drv->safe_state_index = -1;
1306         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1307                 drv->states[i].name[0] = '\0';
1308                 drv->states[i].desc[0] = '\0';
1309         }
1310
1311         if (pr->flags.has_lpi)
1312                 return acpi_processor_setup_lpi_states(pr);
1313
1314         return acpi_processor_setup_cstates(pr);
1315 }
1316
1317 /**
1318  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1319  * device i.e. per-cpu data
1320  *
1321  * @pr: the ACPI processor
1322  * @dev : the cpuidle device
1323  */
1324 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1325                                             struct cpuidle_device *dev)
1326 {
1327         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1328                 return -EINVAL;
1329
1330         dev->cpu = pr->id;
1331         if (pr->flags.has_lpi)
1332                 return acpi_processor_ffh_lpi_probe(pr->id);
1333
1334         return acpi_processor_setup_cpuidle_cx(pr, dev);
1335 }
1336
1337 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1338 {
1339         int ret;
1340
1341         ret = acpi_processor_get_lpi_info(pr);
1342         if (ret)
1343                 ret = acpi_processor_get_cstate_info(pr);
1344
1345         return ret;
1346 }
1347
1348 int acpi_processor_hotplug(struct acpi_processor *pr)
1349 {
1350         int ret = 0;
1351         struct cpuidle_device *dev;
1352
1353         if (disabled_by_idle_boot_param())
1354                 return 0;
1355
1356         if (!pr->flags.power_setup_done)
1357                 return -ENODEV;
1358
1359         dev = per_cpu(acpi_cpuidle_device, pr->id);
1360         cpuidle_pause_and_lock();
1361         cpuidle_disable_device(dev);
1362         ret = acpi_processor_get_power_info(pr);
1363         if (!ret && pr->flags.power) {
1364                 acpi_processor_setup_cpuidle_dev(pr, dev);
1365                 ret = cpuidle_enable_device(dev);
1366         }
1367         cpuidle_resume_and_unlock();
1368
1369         return ret;
1370 }
1371
1372 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1373 {
1374         int cpu;
1375         struct acpi_processor *_pr;
1376         struct cpuidle_device *dev;
1377
1378         if (disabled_by_idle_boot_param())
1379                 return 0;
1380
1381         if (!pr->flags.power_setup_done)
1382                 return -ENODEV;
1383
1384         /*
1385          * FIXME:  Design the ACPI notification to make it once per
1386          * system instead of once per-cpu.  This condition is a hack
1387          * to make the code that updates C-States be called once.
1388          */
1389
1390         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1391
1392                 /* Protect against cpu-hotplug */
1393                 get_online_cpus();
1394                 cpuidle_pause_and_lock();
1395
1396                 /* Disable all cpuidle devices */
1397                 for_each_online_cpu(cpu) {
1398                         _pr = per_cpu(processors, cpu);
1399                         if (!_pr || !_pr->flags.power_setup_done)
1400                                 continue;
1401                         dev = per_cpu(acpi_cpuidle_device, cpu);
1402                         cpuidle_disable_device(dev);
1403                 }
1404
1405                 /* Populate Updated C-state information */
1406                 acpi_processor_get_power_info(pr);
1407                 acpi_processor_setup_cpuidle_states(pr);
1408
1409                 /* Enable all cpuidle devices */
1410                 for_each_online_cpu(cpu) {
1411                         _pr = per_cpu(processors, cpu);
1412                         if (!_pr || !_pr->flags.power_setup_done)
1413                                 continue;
1414                         acpi_processor_get_power_info(_pr);
1415                         if (_pr->flags.power) {
1416                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1417                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1418                                 cpuidle_enable_device(dev);
1419                         }
1420                 }
1421                 cpuidle_resume_and_unlock();
1422                 put_online_cpus();
1423         }
1424
1425         return 0;
1426 }
1427
1428 static int acpi_processor_registered;
1429
1430 int acpi_processor_power_init(struct acpi_processor *pr)
1431 {
1432         int retval;
1433         struct cpuidle_device *dev;
1434
1435         if (disabled_by_idle_boot_param())
1436                 return 0;
1437
1438         acpi_processor_cstate_first_run_checks();
1439
1440         if (!acpi_processor_get_power_info(pr))
1441                 pr->flags.power_setup_done = 1;
1442
1443         /*
1444          * Install the idle handler if processor power management is supported.
1445          * Note that we use previously set idle handler will be used on
1446          * platforms that only support C1.
1447          */
1448         if (pr->flags.power) {
1449                 /* Register acpi_idle_driver if not already registered */
1450                 if (!acpi_processor_registered) {
1451                         acpi_processor_setup_cpuidle_states(pr);
1452                         retval = cpuidle_register_driver(&acpi_idle_driver);
1453                         if (retval)
1454                                 return retval;
1455                         pr_debug("%s registered with cpuidle\n",
1456                                  acpi_idle_driver.name);
1457                 }
1458
1459                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1460                 if (!dev)
1461                         return -ENOMEM;
1462                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1463
1464                 acpi_processor_setup_cpuidle_dev(pr, dev);
1465
1466                 /* Register per-cpu cpuidle_device. Cpuidle driver
1467                  * must already be registered before registering device
1468                  */
1469                 retval = cpuidle_register_device(dev);
1470                 if (retval) {
1471                         if (acpi_processor_registered == 0)
1472                                 cpuidle_unregister_driver(&acpi_idle_driver);
1473                         return retval;
1474                 }
1475                 acpi_processor_registered++;
1476         }
1477         return 0;
1478 }
1479
1480 int acpi_processor_power_exit(struct acpi_processor *pr)
1481 {
1482         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1483
1484         if (disabled_by_idle_boot_param())
1485                 return 0;
1486
1487         if (pr->flags.power) {
1488                 cpuidle_unregister_device(dev);
1489                 acpi_processor_registered--;
1490                 if (acpi_processor_registered == 0)
1491                         cpuidle_unregister_driver(&acpi_idle_driver);
1492         }
1493
1494         pr->flags.power_setup_done = 0;
1495         return 0;
1496 }