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 <[email protected]>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <[email protected]>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <[email protected]>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <[email protected]>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26 #define pr_fmt(fmt) "ACPI: " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <linux/sched.h>       /* need_resched() */
  32 #include <linux/tick.h>
  33 #include <linux/cpuidle.h>
  34 #include <linux/cpu.h>
  35 #include <acpi/processor.h>
  36
  37 /*
  38  * Include the apic definitions for x86 to have the APIC timer related defines
  39  * available also for UP (on SMP it gets magically included via linux/smp.h).
  40  * asm/acpi.h is not an option, as it would require more include magic. Also
  41  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  42  */
  43 #ifdef CONFIG_X86
  44 #include <asm/apic.h>
  45 #endif
  46
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("processor_idle");
  50
  51 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  52
  53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  54 module_param(max_cstate, uint, 0000);
  55 static unsigned int nocst __read_mostly;
  56 module_param(nocst, uint, 0000);
  57 static int bm_check_disable __read_mostly;
  58 module_param(bm_check_disable, uint, 0000);
  59
  60 static unsigned int latency_factor __read_mostly = 2;
  61 module_param(latency_factor, uint, 0644);
  62
  63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  64
  65 struct cpuidle_driver acpi_idle_driver = {
  66         .name =         "acpi_idle",
  67         .owner =        THIS_MODULE,
  68 };
  69
  70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  71 static
  72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  73
  74 static int disabled_by_idle_boot_param(void)
  75 {
  76         return boot_option_idle_override == IDLE_POLL ||
  77                 boot_option_idle_override == IDLE_HALT;
  78 }
  79
  80 /*
  81  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  82  * For now disable this. Probably a bug somewhere else.
  83  *
  84  * To skip this limit, boot/load with a large max_cstate limit.
  85  */
  86 static int set_max_cstate(const struct dmi_system_id *id)
  87 {
  88         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  89                 return 0;
  90
  91         pr_notice("%s detected - limiting to C%ld max_cstate."
  92                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  93                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  94
  95         max_cstate = (long)id->driver_data;
  96
  97         return 0;
  98 }
  99
 100 static const struct dmi_system_id processor_power_dmi_table[] = {
 101         { set_max_cstate, "Clevo 5600D", {
 102           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 103           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 104          (void *)2},
 105         { set_max_cstate, "Pavilion zv5000", {
 106           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 107           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 108          (void *)1},
 109         { set_max_cstate, "Asus L8400B", {
 110           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 111           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 112          (void *)1},
 113         {},
 114 };
 115
 116
 117 /*
 118  * Callers should disable interrupts before the call and enable
 119  * interrupts after return.
 120  */
 121 static void __cpuidle acpi_safe_halt(void)
 122 {
 123         if (!tif_need_resched()) {
 124                 safe_halt();
 125                 local_irq_disable();
 126         }
 127 }
 128
 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 130
 131 /*
 132  * Some BIOS implementations switch to C3 in the published C2 state.
 133  * This seems to be a common problem on AMD boxen, but other vendors
 134  * are affected too. We pick the most conservative approach: we assume
 135  * that the local APIC stops in both C2 and C3.
 136  */
 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 138                                    struct acpi_processor_cx *cx)
 139 {
 140         struct acpi_processor_power *pwr = &pr->power;
 141         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 142
 143         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 144                 return;
 145
 146         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 147                 type = ACPI_STATE_C1;
 148
 149         /*
 150          * Check, if one of the previous states already marked the lapic
 151          * unstable
 152          */
 153         if (pwr->timer_broadcast_on_state < state)
 154                 return;
 155
 156         if (cx->type >= type)
 157                 pr->power.timer_broadcast_on_state = state;
 158 }
 159
 160 static void __lapic_timer_propagate_broadcast(void *arg)
 161 {
 162         struct acpi_processor *pr = (struct acpi_processor *) arg;
 163
 164         if (pr->power.timer_broadcast_on_state < INT_MAX)
 165                 tick_broadcast_enable();
 166         else
 167                 tick_broadcast_disable();
 168 }
 169
 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 171 {
 172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 173                                  (void *)pr, 1);
 174 }
 175
 176 /* Power(C) State timer broadcast control */
 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 178                                        struct acpi_processor_cx *cx,
 179                                        int broadcast)
 180 {
 181         int state = cx - pr->power.states;
 182
 183         if (state >= pr->power.timer_broadcast_on_state) {
 184                 if (broadcast)
 185                         tick_broadcast_enter();
 186                 else
 187                         tick_broadcast_exit();
 188         }
 189 }
 190
 191 #else
 192
 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 194                                    struct acpi_processor_cx *cstate) { }
 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 197                                        struct acpi_processor_cx *cx,
 198                                        int broadcast)
 199 {
 200 }
 201
 202 #endif
 203
 204 #if defined(CONFIG_X86)
 205 static void tsc_check_state(int state)
 206 {
 207         switch (boot_cpu_data.x86_vendor) {
 208         case X86_VENDOR_HYGON:
 209         case X86_VENDOR_AMD:
 210         case X86_VENDOR_INTEL:
 211         case X86_VENDOR_CENTAUR:
 212                 /*
 213                  * AMD Fam10h TSC will tick in all
 214                  * C/P/S0/S1 states when this bit is set.
 215                  */
 216                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 217                         return;
 218
 219                 /*FALL THROUGH*/
 220         default:
 221                 /* TSC could halt in idle, so notify users */
 222                 if (state > ACPI_STATE_C1)
 223                         mark_tsc_unstable("TSC halts in idle");
 224         }
 225 }
 226 #else
 227 static void tsc_check_state(int state) { return; }
 228 #endif
 229
 230 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 231 {
 232
 233         if (!pr->pblk)
 234                 return -ENODEV;
 235
 236         /* if info is obtained from pblk/fadt, type equals state */
 237         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 238         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 239
 240 #ifndef CONFIG_HOTPLUG_CPU
 241         /*
 242          * Check for P_LVL2_UP flag before entering C2 and above on
 243          * an SMP system.
 244          */
 245         if ((num_online_cpus() > 1) &&
 246             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 247                 return -ENODEV;
 248 #endif
 249
 250         /* determine C2 and C3 address from pblk */
 251         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 252         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 253
 254         /* determine latencies from FADT */
 255         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 256         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 257
 258         /*
 259          * FADT specified C2 latency must be less than or equal to
 260          * 100 microseconds.
 261          */
 262         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 263                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 264                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 265                 /* invalidate C2 */
 266                 pr->power.states[ACPI_STATE_C2].address = 0;
 267         }
 268
 269         /*
 270          * FADT supplied C3 latency must be less than or equal to
 271          * 1000 microseconds.
 272          */
 273         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 274                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 275                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 276                 /* invalidate C3 */
 277                 pr->power.states[ACPI_STATE_C3].address = 0;
 278         }
 279
 280         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 281                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 282                           pr->power.states[ACPI_STATE_C2].address,
 283                           pr->power.states[ACPI_STATE_C3].address));
 284
 285         return 0;
 286 }
 287
 288 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 289 {
 290         if (!pr->power.states[ACPI_STATE_C1].valid) {
 291                 /* set the first C-State to C1 */
 292                 /* all processors need to support C1 */
 293                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 294                 pr->power.states[ACPI_STATE_C1].valid = 1;
 295                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 296
 297                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 298                          ACPI_CX_DESC_LEN, "ACPI HLT");
 299         }
 300         /* the C0 state only exists as a filler in our array */
 301         pr->power.states[ACPI_STATE_C0].valid = 1;
 302         return 0;
 303 }
 304
 305 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 306 {
 307         acpi_status status;
 308         u64 count;
 309         int current_count;
 310         int i, ret = 0;
 311         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 312         union acpi_object *cst;
 313
 314         if (nocst)
 315                 return -ENODEV;
 316
 317         current_count = 0;
 318
 319         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 320         if (ACPI_FAILURE(status)) {
 321                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 322                 return -ENODEV;
 323         }
 324
 325         cst = buffer.pointer;
 326
 327         /* There must be at least 2 elements */
 328         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 329                 pr_err("not enough elements in _CST\n");
 330                 ret = -EFAULT;
 331                 goto end;
 332         }
 333
 334         count = cst->package.elements[0].integer.value;
 335
 336         /* Validate number of power states. */
 337         if (count < 1 || count != cst->package.count - 1) {
 338                 pr_err("count given by _CST is not valid\n");
 339                 ret = -EFAULT;
 340                 goto end;
 341         }
 342
 343         /* Tell driver that at least _CST is supported. */
 344         pr->flags.has_cst = 1;
 345
 346         for (i = 1; i <= count; i++) {
 347                 union acpi_object *element;
 348                 union acpi_object *obj;
 349                 struct acpi_power_register *reg;
 350                 struct acpi_processor_cx cx;
 351
 352                 memset(&cx, 0, sizeof(cx));
 353
 354                 element = &(cst->package.elements[i]);
 355                 if (element->type != ACPI_TYPE_PACKAGE)
 356                         continue;
 357
 358                 if (element->package.count != 4)
 359                         continue;
 360
 361                 obj = &(element->package.elements[0]);
 362
 363                 if (obj->type != ACPI_TYPE_BUFFER)
 364                         continue;
 365
 366                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 367
 368                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 369                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 370                         continue;
 371
 372                 /* There should be an easy way to extract an integer... */
 373                 obj = &(element->package.elements[1]);
 374                 if (obj->type != ACPI_TYPE_INTEGER)
 375                         continue;
 376
 377                 cx.type = obj->integer.value;
 378                 /*
 379                  * Some buggy BIOSes won't list C1 in _CST -
 380                  * Let acpi_processor_get_power_info_default() handle them later
 381                  */
 382                 if (i == 1 && cx.type != ACPI_STATE_C1)
 383                         current_count++;
 384
 385                 cx.address = reg->address;
 386                 cx.index = current_count + 1;
 387
 388                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 389                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 390                         if (acpi_processor_ffh_cstate_probe
 391                                         (pr->id, &cx, reg) == 0) {
 392                                 cx.entry_method = ACPI_CSTATE_FFH;
 393                         } else if (cx.type == ACPI_STATE_C1) {
 394                                 /*
 395                                  * C1 is a special case where FIXED_HARDWARE
 396                                  * can be handled in non-MWAIT way as well.
 397                                  * In that case, save this _CST entry info.
 398                                  * Otherwise, ignore this info and continue.
 399                                  */
 400                                 cx.entry_method = ACPI_CSTATE_HALT;
 401                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 402                         } else {
 403                                 continue;
 404                         }
 405                         if (cx.type == ACPI_STATE_C1 &&
 406                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 407                                 /*
 408                                  * In most cases the C1 space_id obtained from
 409                                  * _CST object is FIXED_HARDWARE access mode.
 410                                  * But when the option of idle=halt is added,
 411                                  * the entry_method type should be changed from
 412                                  * CSTATE_FFH to CSTATE_HALT.
 413                                  * When the option of idle=nomwait is added,
 414                                  * the C1 entry_method type should be
 415                                  * CSTATE_HALT.
 416                                  */
 417                                 cx.entry_method = ACPI_CSTATE_HALT;
 418                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 419                         }
 420                 } else {
 421                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 422                                  cx.address);
 423                 }
 424
 425                 if (cx.type == ACPI_STATE_C1) {
 426                         cx.valid = 1;
 427                 }
 428
 429                 obj = &(element->package.elements[2]);
 430                 if (obj->type != ACPI_TYPE_INTEGER)
 431                         continue;
 432
 433                 cx.latency = obj->integer.value;
 434
 435                 obj = &(element->package.elements[3]);
 436                 if (obj->type != ACPI_TYPE_INTEGER)
 437                         continue;
 438
 439                 current_count++;
 440                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 441
 442                 /*
 443                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 444                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 445                  */
 446                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 447                         pr_warn("Limiting number of power states to max (%d)\n",
 448                                 ACPI_PROCESSOR_MAX_POWER);
 449                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 450                         break;
 451                 }
 452         }
 453
 454         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 455                           current_count));
 456
 457         /* Validate number of power states discovered */
 458         if (current_count < 2)
 459                 ret = -EFAULT;
 460
 461       end:
 462         kfree(buffer.pointer);
 463
 464         return ret;
 465 }
 466
 467 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 468                                            struct acpi_processor_cx *cx)
 469 {
 470         static int bm_check_flag = -1;
 471         static int bm_control_flag = -1;
 472
 473
 474         if (!cx->address)
 475                 return;
 476
 477         /*
 478          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 479          * DMA transfers are used by any ISA device to avoid livelock.
 480          * Note that we could disable Type-F DMA (as recommended by
 481          * the erratum), but this is known to disrupt certain ISA
 482          * devices thus we take the conservative approach.
 483          */
 484         else if (errata.piix4.fdma) {
 485                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 486                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 487                 return;
 488         }
 489
 490         /* All the logic here assumes flags.bm_check is same across all CPUs */
 491         if (bm_check_flag == -1) {
 492                 /* Determine whether bm_check is needed based on CPU  */
 493                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 494                 bm_check_flag = pr->flags.bm_check;
 495                 bm_control_flag = pr->flags.bm_control;
 496         } else {
 497                 pr->flags.bm_check = bm_check_flag;
 498                 pr->flags.bm_control = bm_control_flag;
 499         }
 500
 501         if (pr->flags.bm_check) {
 502                 if (!pr->flags.bm_control) {
 503                         if (pr->flags.has_cst != 1) {
 504                                 /* bus mastering control is necessary */
 505                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 506                                         "C3 support requires BM control\n"));
 507                                 return;
 508                         } else {
 509                                 /* Here we enter C3 without bus mastering */
 510                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 511                                         "C3 support without BM control\n"));
 512                         }
 513                 }
 514         } else {
 515                 /*
 516                  * WBINVD should be set in fadt, for C3 state to be
 517                  * supported on when bm_check is not required.
 518                  */
 519                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 520                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 521                                           "Cache invalidation should work properly"
 522                                           " for C3 to be enabled on SMP systems\n"));
 523                         return;
 524                 }
 525         }
 526
 527         /*
 528          * Otherwise we've met all of our C3 requirements.
 529          * Normalize the C3 latency to expidite policy.  Enable
 530          * checking of bus mastering status (bm_check) so we can
 531          * use this in our C3 policy
 532          */
 533         cx->valid = 1;
 534
 535         /*
 536          * On older chipsets, BM_RLD needs to be set
 537          * in order for Bus Master activity to wake the
 538          * system from C3.  Newer chipsets handle DMA
 539          * during C3 automatically and BM_RLD is a NOP.
 540          * In either case, the proper way to
 541          * handle BM_RLD is to set it and leave it set.
 542          */
 543         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 544
 545         return;
 546 }
 547
 548 static int acpi_processor_power_verify(struct acpi_processor *pr)
 549 {
 550         unsigned int i;
 551         unsigned int working = 0;
 552
 553         pr->power.timer_broadcast_on_state = INT_MAX;
 554
 555         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 556                 struct acpi_processor_cx *cx = &pr->power.states[i];
 557
 558                 switch (cx->type) {
 559                 case ACPI_STATE_C1:
 560                         cx->valid = 1;
 561                         break;
 562
 563                 case ACPI_STATE_C2:
 564                         if (!cx->address)
 565                                 break;
 566                         cx->valid = 1;
 567                         break;
 568
 569                 case ACPI_STATE_C3:
 570                         acpi_processor_power_verify_c3(pr, cx);
 571                         break;
 572                 }
 573                 if (!cx->valid)
 574                         continue;
 575
 576                 lapic_timer_check_state(i, pr, cx);
 577                 tsc_check_state(cx->type);
 578                 working++;
 579         }
 580
 581         lapic_timer_propagate_broadcast(pr);
 582
 583         return (working);
 584 }
 585
 586 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 587 {
 588         unsigned int i;
 589         int result;
 590
 591
 592         /* NOTE: the idle thread may not be running while calling
 593          * this function */
 594
 595         /* Zero initialize all the C-states info. */
 596         memset(pr->power.states, 0, sizeof(pr->power.states));
 597
 598         result = acpi_processor_get_power_info_cst(pr);
 599         if (result == -ENODEV)
 600                 result = acpi_processor_get_power_info_fadt(pr);
 601
 602         if (result)
 603                 return result;
 604
 605         acpi_processor_get_power_info_default(pr);
 606
 607         pr->power.count = acpi_processor_power_verify(pr);
 608
 609         /*
 610          * if one state of type C2 or C3 is available, mark this
 611          * CPU as being "idle manageable"
 612          */
 613         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 614                 if (pr->power.states[i].valid) {
 615                         pr->power.count = i;
 616                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 617                                 pr->flags.power = 1;
 618                 }
 619         }
 620
 621         return 0;
 622 }
 623
 624 /**
 625  * acpi_idle_bm_check - checks if bus master activity was detected
 626  */
 627 static int acpi_idle_bm_check(void)
 628 {
 629         u32 bm_status = 0;
 630
 631         if (bm_check_disable)
 632                 return 0;
 633
 634         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 635         if (bm_status)
 636                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 637         /*
 638          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 639          * the true state of bus mastering activity; forcing us to
 640          * manually check the BMIDEA bit of each IDE channel.
 641          */
 642         else if (errata.piix4.bmisx) {
 643                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 644                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 645                         bm_status = 1;
 646         }
 647         return bm_status;
 648 }
 649
 650 /**
 651  * acpi_idle_do_entry - enter idle state using the appropriate method
 652  * @cx: cstate data
 653  *
 654  * Caller disables interrupt before call and enables interrupt after return.
 655  */
 656 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 657 {
 658         if (cx->entry_method == ACPI_CSTATE_FFH) {
 659                 /* Call into architectural FFH based C-state */
 660                 acpi_processor_ffh_cstate_enter(cx);
 661         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 662                 acpi_safe_halt();
 663         } else {
 664                 /* IO port based C-state */
 665                 inb(cx->address);
 666                 /* Dummy wait op - must do something useless after P_LVL2 read
 667                    because chipsets cannot guarantee that STPCLK# signal
 668                    gets asserted in time to freeze execution properly. */
 669                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 670         }
 671 }
 672
 673 /**
 674  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 675  * @dev: the target CPU
 676  * @index: the index of suggested state
 677  */
 678 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 679 {
 680         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 681
 682         ACPI_FLUSH_CPU_CACHE();
 683
 684         while (1) {
 685
 686                 if (cx->entry_method == ACPI_CSTATE_HALT)
 687                         safe_halt();
 688                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 689                         inb(cx->address);
 690                         /* See comment in acpi_idle_do_entry() */
 691                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 692                 } else
 693                         return -ENODEV;
 694         }
 695
 696         /* Never reached */
 697         return 0;
 698 }
 699
 700 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 701 {
 702         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 703                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 704 }
 705
 706 static int c3_cpu_count;
 707 static DEFINE_RAW_SPINLOCK(c3_lock);
 708
 709 /**
 710  * acpi_idle_enter_bm - enters C3 with proper BM handling
 711  * @pr: Target processor
 712  * @cx: Target state context
 713  * @timer_bc: Whether or not to change timer mode to broadcast
 714  */
 715 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 716                                struct acpi_processor_cx *cx, bool timer_bc)
 717 {
 718         acpi_unlazy_tlb(smp_processor_id());
 719
 720         /*
 721          * Must be done before busmaster disable as we might need to
 722          * access HPET !
 723          */
 724         if (timer_bc)
 725                 lapic_timer_state_broadcast(pr, cx, 1);
 726
 727         /*
 728          * disable bus master
 729          * bm_check implies we need ARB_DIS
 730          * bm_control implies whether we can do ARB_DIS
 731          *
 732          * That leaves a case where bm_check is set and bm_control is
 733          * not set. In that case we cannot do much, we enter C3
 734          * without doing anything.
 735          */
 736         if (pr->flags.bm_control) {
 737                 raw_spin_lock(&c3_lock);
 738                 c3_cpu_count++;
 739                 /* Disable bus master arbitration when all CPUs are in C3 */
 740                 if (c3_cpu_count == num_online_cpus())
 741                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 742                 raw_spin_unlock(&c3_lock);
 743         }
 744
 745         acpi_idle_do_entry(cx);
 746
 747         /* Re-enable bus master arbitration */
 748         if (pr->flags.bm_control) {
 749                 raw_spin_lock(&c3_lock);
 750                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 751                 c3_cpu_count--;
 752                 raw_spin_unlock(&c3_lock);
 753         }
 754
 755         if (timer_bc)
 756                 lapic_timer_state_broadcast(pr, cx, 0);
 757 }
 758
 759 static int acpi_idle_enter(struct cpuidle_device *dev,
 760                            struct cpuidle_driver *drv, int index)
 761 {
 762         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 763         struct acpi_processor *pr;
 764
 765         pr = __this_cpu_read(processors);
 766         if (unlikely(!pr))
 767                 return -EINVAL;
 768
 769         if (cx->type != ACPI_STATE_C1) {
 770                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 771                         index = ACPI_IDLE_STATE_START;
 772                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 773                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 774                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 775                                 acpi_idle_enter_bm(pr, cx, true);
 776                                 return index;
 777                         } else if (drv->safe_state_index >= 0) {
 778                                 index = drv->safe_state_index;
 779                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 780                         } else {
 781                                 acpi_safe_halt();
 782                                 return -EBUSY;
 783                         }
 784                 }
 785         }
 786
 787         lapic_timer_state_broadcast(pr, cx, 1);
 788
 789         if (cx->type == ACPI_STATE_C3)
 790                 ACPI_FLUSH_CPU_CACHE();
 791
 792         acpi_idle_do_entry(cx);
 793
 794         lapic_timer_state_broadcast(pr, cx, 0);
 795
 796         return index;
 797 }
 798
 799 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 800                                    struct cpuidle_driver *drv, int index)
 801 {
 802         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 803
 804         if (cx->type == ACPI_STATE_C3) {
 805                 struct acpi_processor *pr = __this_cpu_read(processors);
 806
 807                 if (unlikely(!pr))
 808                         return;
 809
 810                 if (pr->flags.bm_check) {
 811                         acpi_idle_enter_bm(pr, cx, false);
 812                         return;
 813                 } else {
 814                         ACPI_FLUSH_CPU_CACHE();
 815                 }
 816         }
 817         acpi_idle_do_entry(cx);
 818 }
 819
 820 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 821                                            struct cpuidle_device *dev)
 822 {
 823         int i, count = ACPI_IDLE_STATE_START;
 824         struct acpi_processor_cx *cx;
 825
 826         if (max_cstate == 0)
 827                 max_cstate = 1;
 828
 829         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 830                 cx = &pr->power.states[i];
 831
 832                 if (!cx->valid)
 833                         continue;
 834
 835                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 836
 837                 count++;
 838                 if (count == CPUIDLE_STATE_MAX)
 839                         break;
 840         }
 841
 842         if (!count)
 843                 return -EINVAL;
 844
 845         return 0;
 846 }
 847
 848 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 849 {
 850         int i, count;
 851         struct acpi_processor_cx *cx;
 852         struct cpuidle_state *state;
 853         struct cpuidle_driver *drv = &acpi_idle_driver;
 854
 855         if (max_cstate == 0)
 856                 max_cstate = 1;
 857
 858         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 859                 cpuidle_poll_state_init(drv);
 860                 count = 1;
 861         } else {
 862                 count = 0;
 863         }
 864
 865         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 866                 cx = &pr->power.states[i];
 867
 868                 if (!cx->valid)
 869                         continue;
 870
 871                 state = &drv->states[count];
 872                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 873                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 874                 state->exit_latency = cx->latency;
 875                 state->target_residency = cx->latency * latency_factor;
 876                 state->enter = acpi_idle_enter;
 877
 878                 state->flags = 0;
 879                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 880                         state->enter_dead = acpi_idle_play_dead;
 881                         drv->safe_state_index = count;
 882                 }
 883                 /*
 884                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 885                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 886                  * particularly interesting from the suspend-to-idle angle, so
 887                  * avoid C1 and the situations in which we may need to fall back
 888                  * to it altogether.
 889                  */
 890                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 891                         state->enter_s2idle = acpi_idle_enter_s2idle;
 892
 893                 count++;
 894                 if (count == CPUIDLE_STATE_MAX)
 895                         break;
 896         }
 897
 898         drv->state_count = count;
 899
 900         if (!count)
 901                 return -EINVAL;
 902
 903         return 0;
 904 }
 905
 906 static inline void acpi_processor_cstate_first_run_checks(void)
 907 {
 908         acpi_status status;
 909         static int first_run;
 910
 911         if (first_run)
 912                 return;
 913         dmi_check_system(processor_power_dmi_table);
 914         max_cstate = acpi_processor_cstate_check(max_cstate);
 915         if (max_cstate < ACPI_C_STATES_MAX)
 916                 pr_notice("ACPI: processor limited to max C-state %d\n",
 917                           max_cstate);
 918         first_run++;
 919
 920         if (acpi_gbl_FADT.cst_control && !nocst) {
 921                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 922                                             acpi_gbl_FADT.cst_control, 8);
 923                 if (ACPI_FAILURE(status))
 924                         ACPI_EXCEPTION((AE_INFO, status,
 925                                         "Notifying BIOS of _CST ability failed"));
 926         }
 927 }
 928 #else
 929
 930 static inline int disabled_by_idle_boot_param(void) { return 0; }
 931 static inline void acpi_processor_cstate_first_run_checks(void) { }
 932 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 933 {
 934         return -ENODEV;
 935 }
 936
 937 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 938                                            struct cpuidle_device *dev)
 939 {
 940         return -EINVAL;
 941 }
 942
 943 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 944 {
 945         return -EINVAL;
 946 }
 947
 948 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 949
 950 struct acpi_lpi_states_array {
 951         unsigned int size;
 952         unsigned int composite_states_size;
 953         struct acpi_lpi_state *entries;
 954         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 955 };
 956
 957 static int obj_get_integer(union acpi_object *obj, u32 *value)
 958 {
 959         if (obj->type != ACPI_TYPE_INTEGER)
 960                 return -EINVAL;
 961
 962         *value = obj->integer.value;
 963         return 0;
 964 }
 965
 966 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 967                                        struct acpi_lpi_states_array *info)
 968 {
 969         acpi_status status;
 970         int ret = 0;
 971         int pkg_count, state_idx = 1, loop;
 972         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 973         union acpi_object *lpi_data;
 974         struct acpi_lpi_state *lpi_state;
 975
 976         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 977         if (ACPI_FAILURE(status)) {
 978                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 979                 return -ENODEV;
 980         }
 981
 982         lpi_data = buffer.pointer;
 983
 984         /* There must be at least 4 elements = 3 elements + 1 package */
 985         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 986             lpi_data->package.count < 4) {
 987                 pr_debug("not enough elements in _LPI\n");
 988                 ret = -ENODATA;
 989                 goto end;
 990         }
 991
 992         pkg_count = lpi_data->package.elements[2].integer.value;
 993
 994         /* Validate number of power states. */
 995         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 996                 pr_debug("count given by _LPI is not valid\n");
 997                 ret = -ENODATA;
 998                 goto end;
 999         }
1000
1001         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1002         if (!lpi_state) {
1003                 ret = -ENOMEM;
1004                 goto end;
1005         }
1006
1007         info->size = pkg_count;
1008         info->entries = lpi_state;
1009
1010         /* LPI States start at index 3 */
1011         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1012                 union acpi_object *element, *pkg_elem, *obj;
1013
1014                 element = &lpi_data->package.elements[loop];
1015                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1016                         continue;
1017
1018                 pkg_elem = element->package.elements;
1019
1020                 obj = pkg_elem + 6;
1021                 if (obj->type == ACPI_TYPE_BUFFER) {
1022                         struct acpi_power_register *reg;
1023
1024                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1025                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1026                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1027                                 continue;
1028
1029                         lpi_state->address = reg->address;
1030                         lpi_state->entry_method =
1031                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1032                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1033                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1034                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1035                         lpi_state->address = obj->integer.value;
1036                 } else {
1037                         continue;
1038                 }
1039
1040                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1041
1042                 obj = pkg_elem + 9;
1043                 if (obj->type == ACPI_TYPE_STRING)
1044                         strlcpy(lpi_state->desc, obj->string.pointer,
1045                                 ACPI_CX_DESC_LEN);
1046
1047                 lpi_state->index = state_idx;
1048                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1049                         pr_debug("No min. residency found, assuming 10 us\n");
1050                         lpi_state->min_residency = 10;
1051                 }
1052
1053                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1054                         pr_debug("No wakeup residency found, assuming 10 us\n");
1055                         lpi_state->wake_latency = 10;
1056                 }
1057
1058                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1059                         lpi_state->flags = 0;
1060
1061                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1062                         lpi_state->arch_flags = 0;
1063
1064                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1065                         lpi_state->res_cnt_freq = 1;
1066
1067                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1068                         lpi_state->enable_parent_state = 0;
1069         }
1070
1071         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1072 end:
1073         kfree(buffer.pointer);
1074         return ret;
1075 }
1076
1077 /*
1078  * flat_state_cnt - the number of composite LPI states after the process of flattening
1079  */
1080 static int flat_state_cnt;
1081
1082 /**
1083  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1084  *
1085  * @local: local LPI state
1086  * @parent: parent LPI state
1087  * @result: composite LPI state
1088  */
1089 static bool combine_lpi_states(struct acpi_lpi_state *local,
1090                                struct acpi_lpi_state *parent,
1091                                struct acpi_lpi_state *result)
1092 {
1093         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1094                 if (!parent->address) /* 0 means autopromotable */
1095                         return false;
1096                 result->address = local->address + parent->address;
1097         } else {
1098                 result->address = parent->address;
1099         }
1100
1101         result->min_residency = max(local->min_residency, parent->min_residency);
1102         result->wake_latency = local->wake_latency + parent->wake_latency;
1103         result->enable_parent_state = parent->enable_parent_state;
1104         result->entry_method = local->entry_method;
1105
1106         result->flags = parent->flags;
1107         result->arch_flags = parent->arch_flags;
1108         result->index = parent->index;
1109
1110         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1111         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1112         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1113         return true;
1114 }
1115
1116 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1117
1118 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1119                                   struct acpi_lpi_state *t)
1120 {
1121         curr_level->composite_states[curr_level->composite_states_size++] = t;
1122 }
1123
1124 static int flatten_lpi_states(struct acpi_processor *pr,
1125                               struct acpi_lpi_states_array *curr_level,
1126                               struct acpi_lpi_states_array *prev_level)
1127 {
1128         int i, j, state_count = curr_level->size;
1129         struct acpi_lpi_state *p, *t = curr_level->entries;
1130
1131         curr_level->composite_states_size = 0;
1132         for (j = 0; j < state_count; j++, t++) {
1133                 struct acpi_lpi_state *flpi;
1134
1135                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1136                         continue;
1137
1138                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1139                         pr_warn("Limiting number of LPI states to max (%d)\n",
1140                                 ACPI_PROCESSOR_MAX_POWER);
1141                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1142                         break;
1143                 }
1144
1145                 flpi = &pr->power.lpi_states[flat_state_cnt];
1146
1147                 if (!prev_level) { /* leaf/processor node */
1148                         memcpy(flpi, t, sizeof(*t));
1149                         stash_composite_state(curr_level, flpi);
1150                         flat_state_cnt++;
1151                         continue;
1152                 }
1153
1154                 for (i = 0; i < prev_level->composite_states_size; i++) {
1155                         p = prev_level->composite_states[i];
1156                         if (t->index <= p->enable_parent_state &&
1157                             combine_lpi_states(p, t, flpi)) {
1158                                 stash_composite_state(curr_level, flpi);
1159                                 flat_state_cnt++;
1160                                 flpi++;
1161                         }
1162                 }
1163         }
1164
1165         kfree(curr_level->entries);
1166         return 0;
1167 }
1168
1169 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1170 {
1171         int ret, i;
1172         acpi_status status;
1173         acpi_handle handle = pr->handle, pr_ahandle;
1174         struct acpi_device *d = NULL;
1175         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1176
1177         if (!osc_pc_lpi_support_confirmed)
1178                 return -EOPNOTSUPP;
1179
1180         if (!acpi_has_method(handle, "_LPI"))
1181                 return -EINVAL;
1182
1183         flat_state_cnt = 0;
1184         prev = &info[0];
1185         curr = &info[1];
1186         handle = pr->handle;
1187         ret = acpi_processor_evaluate_lpi(handle, prev);
1188         if (ret)
1189                 return ret;
1190         flatten_lpi_states(pr, prev, NULL);
1191
1192         status = acpi_get_parent(handle, &pr_ahandle);
1193         while (ACPI_SUCCESS(status)) {
1194                 acpi_bus_get_device(pr_ahandle, &d);
1195                 handle = pr_ahandle;
1196
1197                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1198                         break;
1199
1200                 /* can be optional ? */
1201                 if (!acpi_has_method(handle, "_LPI"))
1202                         break;
1203
1204                 ret = acpi_processor_evaluate_lpi(handle, curr);
1205                 if (ret)
1206                         break;
1207
1208                 /* flatten all the LPI states in this level of hierarchy */
1209                 flatten_lpi_states(pr, curr, prev);
1210
1211                 tmp = prev, prev = curr, curr = tmp;
1212
1213                 status = acpi_get_parent(handle, &pr_ahandle);
1214         }
1215
1216         pr->power.count = flat_state_cnt;
1217         /* reset the index after flattening */
1218         for (i = 0; i < pr->power.count; i++)
1219                 pr->power.lpi_states[i].index = i;
1220
1221         /* Tell driver that _LPI is supported. */
1222         pr->flags.has_lpi = 1;
1223         pr->flags.power = 1;
1224
1225         return 0;
1226 }
1227
1228 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1229 {
1230         return -ENODEV;
1231 }
1232
1233 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1234 {
1235         return -ENODEV;
1236 }
1237
1238 /**
1239  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1240  * @dev: the target CPU
1241  * @drv: cpuidle driver containing cpuidle state info
1242  * @index: index of target state
1243  *
1244  * Return: 0 for success or negative value for error
1245  */
1246 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1247                                struct cpuidle_driver *drv, int index)
1248 {
1249         struct acpi_processor *pr;
1250         struct acpi_lpi_state *lpi;
1251
1252         pr = __this_cpu_read(processors);
1253
1254         if (unlikely(!pr))
1255                 return -EINVAL;
1256
1257         lpi = &pr->power.lpi_states[index];
1258         if (lpi->entry_method == ACPI_CSTATE_FFH)
1259                 return acpi_processor_ffh_lpi_enter(lpi);
1260
1261         return -EINVAL;
1262 }
1263
1264 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1265 {
1266         int i;
1267         struct acpi_lpi_state *lpi;
1268         struct cpuidle_state *state;
1269         struct cpuidle_driver *drv = &acpi_idle_driver;
1270
1271         if (!pr->flags.has_lpi)
1272                 return -EOPNOTSUPP;
1273
1274         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1275                 lpi = &pr->power.lpi_states[i];
1276
1277                 state = &drv->states[i];
1278                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1279                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1280                 state->exit_latency = lpi->wake_latency;
1281                 state->target_residency = lpi->min_residency;
1282                 if (lpi->arch_flags)
1283                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1284                 state->enter = acpi_idle_lpi_enter;
1285                 drv->safe_state_index = i;
1286         }
1287
1288         drv->state_count = i;
1289
1290         return 0;
1291 }
1292
1293 /**
1294  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1295  * global state data i.e. idle routines
1296  *
1297  * @pr: the ACPI processor
1298  */
1299 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1300 {
1301         int i;
1302         struct cpuidle_driver *drv = &acpi_idle_driver;
1303
1304         if (!pr->flags.power_setup_done || !pr->flags.power)
1305                 return -EINVAL;
1306
1307         drv->safe_state_index = -1;
1308         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1309                 drv->states[i].name[0] = '\0';
1310                 drv->states[i].desc[0] = '\0';
1311         }
1312
1313         if (pr->flags.has_lpi)
1314                 return acpi_processor_setup_lpi_states(pr);
1315
1316         return acpi_processor_setup_cstates(pr);
1317 }
1318
1319 /**
1320  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1321  * device i.e. per-cpu data
1322  *
1323  * @pr: the ACPI processor
1324  * @dev : the cpuidle device
1325  */
1326 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1327                                             struct cpuidle_device *dev)
1328 {
1329         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1330                 return -EINVAL;
1331
1332         dev->cpu = pr->id;
1333         if (pr->flags.has_lpi)
1334                 return acpi_processor_ffh_lpi_probe(pr->id);
1335
1336         return acpi_processor_setup_cpuidle_cx(pr, dev);
1337 }
1338
1339 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1340 {
1341         int ret;
1342
1343         ret = acpi_processor_get_lpi_info(pr);
1344         if (ret)
1345                 ret = acpi_processor_get_cstate_info(pr);
1346
1347         return ret;
1348 }
1349
1350 int acpi_processor_hotplug(struct acpi_processor *pr)
1351 {
1352         int ret = 0;
1353         struct cpuidle_device *dev;
1354
1355         if (disabled_by_idle_boot_param())
1356                 return 0;
1357
1358         if (!pr->flags.power_setup_done)
1359                 return -ENODEV;
1360
1361         dev = per_cpu(acpi_cpuidle_device, pr->id);
1362         cpuidle_pause_and_lock();
1363         cpuidle_disable_device(dev);
1364         ret = acpi_processor_get_power_info(pr);
1365         if (!ret && pr->flags.power) {
1366                 acpi_processor_setup_cpuidle_dev(pr, dev);
1367                 ret = cpuidle_enable_device(dev);
1368         }
1369         cpuidle_resume_and_unlock();
1370
1371         return ret;
1372 }
1373
1374 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1375 {
1376         int cpu;
1377         struct acpi_processor *_pr;
1378         struct cpuidle_device *dev;
1379
1380         if (disabled_by_idle_boot_param())
1381                 return 0;
1382
1383         if (!pr->flags.power_setup_done)
1384                 return -ENODEV;
1385
1386         /*
1387          * FIXME:  Design the ACPI notification to make it once per
1388          * system instead of once per-cpu.  This condition is a hack
1389          * to make the code that updates C-States be called once.
1390          */
1391
1392         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1393
1394                 /* Protect against cpu-hotplug */
1395                 get_online_cpus();
1396                 cpuidle_pause_and_lock();
1397
1398                 /* Disable all cpuidle devices */
1399                 for_each_online_cpu(cpu) {
1400                         _pr = per_cpu(processors, cpu);
1401                         if (!_pr || !_pr->flags.power_setup_done)
1402                                 continue;
1403                         dev = per_cpu(acpi_cpuidle_device, cpu);
1404                         cpuidle_disable_device(dev);
1405                 }
1406
1407                 /* Populate Updated C-state information */
1408                 acpi_processor_get_power_info(pr);
1409                 acpi_processor_setup_cpuidle_states(pr);
1410
1411                 /* Enable all cpuidle devices */
1412                 for_each_online_cpu(cpu) {
1413                         _pr = per_cpu(processors, cpu);
1414                         if (!_pr || !_pr->flags.power_setup_done)
1415                                 continue;
1416                         acpi_processor_get_power_info(_pr);
1417                         if (_pr->flags.power) {
1418                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1419                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1420                                 cpuidle_enable_device(dev);
1421                         }
1422                 }
1423                 cpuidle_resume_and_unlock();
1424                 put_online_cpus();
1425         }
1426
1427         return 0;
1428 }
1429
1430 static int acpi_processor_registered;
1431
1432 int acpi_processor_power_init(struct acpi_processor *pr)
1433 {
1434         int retval;
1435         struct cpuidle_device *dev;
1436
1437         if (disabled_by_idle_boot_param())
1438                 return 0;
1439
1440         acpi_processor_cstate_first_run_checks();
1441
1442         if (!acpi_processor_get_power_info(pr))
1443                 pr->flags.power_setup_done = 1;
1444
1445         /*
1446          * Install the idle handler if processor power management is supported.
1447          * Note that we use previously set idle handler will be used on
1448          * platforms that only support C1.
1449          */
1450         if (pr->flags.power) {
1451                 /* Register acpi_idle_driver if not already registered */
1452                 if (!acpi_processor_registered) {
1453                         acpi_processor_setup_cpuidle_states(pr);
1454                         retval = cpuidle_register_driver(&acpi_idle_driver);
1455                         if (retval)
1456                                 return retval;
1457                         pr_debug("%s registered with cpuidle\n",
1458                                  acpi_idle_driver.name);
1459                 }
1460
1461                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1462                 if (!dev)
1463                         return -ENOMEM;
1464                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1465
1466                 acpi_processor_setup_cpuidle_dev(pr, dev);
1467
1468                 /* Register per-cpu cpuidle_device. Cpuidle driver
1469                  * must already be registered before registering device
1470                  */
1471                 retval = cpuidle_register_device(dev);
1472                 if (retval) {
1473                         if (acpi_processor_registered == 0)
1474                                 cpuidle_unregister_driver(&acpi_idle_driver);
1475                         return retval;
1476                 }
1477                 acpi_processor_registered++;
1478         }
1479         return 0;
1480 }
1481
1482 int acpi_processor_power_exit(struct acpi_processor *pr)
1483 {
1484         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1485
1486         if (disabled_by_idle_boot_param())
1487                 return 0;
1488
1489         if (pr->flags.power) {
1490                 cpuidle_unregister_device(dev);
1491                 acpi_processor_registered--;
1492                 if (acpi_processor_registered == 0)
1493                         cpuidle_unregister_driver(&acpi_idle_driver);
1494         }
1495
1496         pr->flags.power_setup_done = 0;
1497         return 0;
1498 }