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 <acpi/processor.h>
  35
  36 /*
  37  * Include the apic definitions for x86 to have the APIC timer related defines
  38  * available also for UP (on SMP it gets magically included via linux/smp.h).
  39  * asm/acpi.h is not an option, as it would require more include magic. Also
  40  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  41  */
  42 #ifdef CONFIG_X86
  43 #include <asm/apic.h>
  44 #endif
  45
  46 #define ACPI_PROCESSOR_CLASS            "processor"
  47 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  48 ACPI_MODULE_NAME("processor_idle");
  49
  50 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  51 module_param(max_cstate, uint, 0000);
  52 static unsigned int nocst __read_mostly;
  53 module_param(nocst, uint, 0000);
  54 static int bm_check_disable __read_mostly;
  55 module_param(bm_check_disable, uint, 0000);
  56
  57 static unsigned int latency_factor __read_mostly = 2;
  58 module_param(latency_factor, uint, 0644);
  59
  60 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  61
  62 struct cpuidle_driver acpi_idle_driver = {
  63         .name =         "acpi_idle",
  64         .owner =        THIS_MODULE,
  65 };
  66
  67 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  68 static
  69 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  70
  71 static int disabled_by_idle_boot_param(void)
  72 {
  73         return boot_option_idle_override == IDLE_POLL ||
  74                 boot_option_idle_override == IDLE_HALT;
  75 }
  76
  77 /*
  78  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  79  * For now disable this. Probably a bug somewhere else.
  80  *
  81  * To skip this limit, boot/load with a large max_cstate limit.
  82  */
  83 static int set_max_cstate(const struct dmi_system_id *id)
  84 {
  85         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  86                 return 0;
  87
  88         pr_notice("%s detected - limiting to C%ld max_cstate."
  89                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  90                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  91
  92         max_cstate = (long)id->driver_data;
  93
  94         return 0;
  95 }
  96
  97 static const struct dmi_system_id processor_power_dmi_table[] = {
  98         { set_max_cstate, "Clevo 5600D", {
  99           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 100           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 101          (void *)2},
 102         { set_max_cstate, "Pavilion zv5000", {
 103           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 104           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 105          (void *)1},
 106         { set_max_cstate, "Asus L8400B", {
 107           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 108           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 109          (void *)1},
 110         {},
 111 };
 112
 113
 114 /*
 115  * Callers should disable interrupts before the call and enable
 116  * interrupts after return.
 117  */
 118 static void acpi_safe_halt(void)
 119 {
 120         if (!tif_need_resched()) {
 121                 safe_halt();
 122                 local_irq_disable();
 123         }
 124 }
 125
 126 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 127
 128 /*
 129  * Some BIOS implementations switch to C3 in the published C2 state.
 130  * This seems to be a common problem on AMD boxen, but other vendors
 131  * are affected too. We pick the most conservative approach: we assume
 132  * that the local APIC stops in both C2 and C3.
 133  */
 134 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 135                                    struct acpi_processor_cx *cx)
 136 {
 137         struct acpi_processor_power *pwr = &pr->power;
 138         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 139
 140         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 141                 return;
 142
 143         if (amd_e400_c1e_detected)
 144                 type = ACPI_STATE_C1;
 145
 146         /*
 147          * Check, if one of the previous states already marked the lapic
 148          * unstable
 149          */
 150         if (pwr->timer_broadcast_on_state < state)
 151                 return;
 152
 153         if (cx->type >= type)
 154                 pr->power.timer_broadcast_on_state = state;
 155 }
 156
 157 static void __lapic_timer_propagate_broadcast(void *arg)
 158 {
 159         struct acpi_processor *pr = (struct acpi_processor *) arg;
 160
 161         if (pr->power.timer_broadcast_on_state < INT_MAX)
 162                 tick_broadcast_enable();
 163         else
 164                 tick_broadcast_disable();
 165 }
 166
 167 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 168 {
 169         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 170                                  (void *)pr, 1);
 171 }
 172
 173 /* Power(C) State timer broadcast control */
 174 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 175                                        struct acpi_processor_cx *cx,
 176                                        int broadcast)
 177 {
 178         int state = cx - pr->power.states;
 179
 180         if (state >= pr->power.timer_broadcast_on_state) {
 181                 if (broadcast)
 182                         tick_broadcast_enter();
 183                 else
 184                         tick_broadcast_exit();
 185         }
 186 }
 187
 188 #else
 189
 190 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 191                                    struct acpi_processor_cx *cstate) { }
 192 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 193 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 194                                        struct acpi_processor_cx *cx,
 195                                        int broadcast)
 196 {
 197 }
 198
 199 #endif
 200
 201 #if defined(CONFIG_X86)
 202 static void tsc_check_state(int state)
 203 {
 204         switch (boot_cpu_data.x86_vendor) {
 205         case X86_VENDOR_AMD:
 206         case X86_VENDOR_INTEL:
 207                 /*
 208                  * AMD Fam10h TSC will tick in all
 209                  * C/P/S0/S1 states when this bit is set.
 210                  */
 211                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 212                         return;
 213
 214                 /*FALL THROUGH*/
 215         default:
 216                 /* TSC could halt in idle, so notify users */
 217                 if (state > ACPI_STATE_C1)
 218                         mark_tsc_unstable("TSC halts in idle");
 219         }
 220 }
 221 #else
 222 static void tsc_check_state(int state) { return; }
 223 #endif
 224
 225 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 226 {
 227
 228         if (!pr->pblk)
 229                 return -ENODEV;
 230
 231         /* if info is obtained from pblk/fadt, type equals state */
 232         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 233         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 234
 235 #ifndef CONFIG_HOTPLUG_CPU
 236         /*
 237          * Check for P_LVL2_UP flag before entering C2 and above on
 238          * an SMP system.
 239          */
 240         if ((num_online_cpus() > 1) &&
 241             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 242                 return -ENODEV;
 243 #endif
 244
 245         /* determine C2 and C3 address from pblk */
 246         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 247         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 248
 249         /* determine latencies from FADT */
 250         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 251         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 252
 253         /*
 254          * FADT specified C2 latency must be less than or equal to
 255          * 100 microseconds.
 256          */
 257         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 258                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 259                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 260                 /* invalidate C2 */
 261                 pr->power.states[ACPI_STATE_C2].address = 0;
 262         }
 263
 264         /*
 265          * FADT supplied C3 latency must be less than or equal to
 266          * 1000 microseconds.
 267          */
 268         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 269                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 270                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 271                 /* invalidate C3 */
 272                 pr->power.states[ACPI_STATE_C3].address = 0;
 273         }
 274
 275         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 276                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 277                           pr->power.states[ACPI_STATE_C2].address,
 278                           pr->power.states[ACPI_STATE_C3].address));
 279
 280         return 0;
 281 }
 282
 283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 284 {
 285         if (!pr->power.states[ACPI_STATE_C1].valid) {
 286                 /* set the first C-State to C1 */
 287                 /* all processors need to support C1 */
 288                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 289                 pr->power.states[ACPI_STATE_C1].valid = 1;
 290                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 291         }
 292         /* the C0 state only exists as a filler in our array */
 293         pr->power.states[ACPI_STATE_C0].valid = 1;
 294         return 0;
 295 }
 296
 297 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 298 {
 299         acpi_status status;
 300         u64 count;
 301         int current_count;
 302         int i, ret = 0;
 303         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 304         union acpi_object *cst;
 305
 306         if (nocst)
 307                 return -ENODEV;
 308
 309         current_count = 0;
 310
 311         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 312         if (ACPI_FAILURE(status)) {
 313                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 314                 return -ENODEV;
 315         }
 316
 317         cst = buffer.pointer;
 318
 319         /* There must be at least 2 elements */
 320         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 321                 pr_err("not enough elements in _CST\n");
 322                 ret = -EFAULT;
 323                 goto end;
 324         }
 325
 326         count = cst->package.elements[0].integer.value;
 327
 328         /* Validate number of power states. */
 329         if (count < 1 || count != cst->package.count - 1) {
 330                 pr_err("count given by _CST is not valid\n");
 331                 ret = -EFAULT;
 332                 goto end;
 333         }
 334
 335         /* Tell driver that at least _CST is supported. */
 336         pr->flags.has_cst = 1;
 337
 338         for (i = 1; i <= count; i++) {
 339                 union acpi_object *element;
 340                 union acpi_object *obj;
 341                 struct acpi_power_register *reg;
 342                 struct acpi_processor_cx cx;
 343
 344                 memset(&cx, 0, sizeof(cx));
 345
 346                 element = &(cst->package.elements[i]);
 347                 if (element->type != ACPI_TYPE_PACKAGE)
 348                         continue;
 349
 350                 if (element->package.count != 4)
 351                         continue;
 352
 353                 obj = &(element->package.elements[0]);
 354
 355                 if (obj->type != ACPI_TYPE_BUFFER)
 356                         continue;
 357
 358                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 359
 360                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 361                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 362                         continue;
 363
 364                 /* There should be an easy way to extract an integer... */
 365                 obj = &(element->package.elements[1]);
 366                 if (obj->type != ACPI_TYPE_INTEGER)
 367                         continue;
 368
 369                 cx.type = obj->integer.value;
 370                 /*
 371                  * Some buggy BIOSes won't list C1 in _CST -
 372                  * Let acpi_processor_get_power_info_default() handle them later
 373                  */
 374                 if (i == 1 && cx.type != ACPI_STATE_C1)
 375                         current_count++;
 376
 377                 cx.address = reg->address;
 378                 cx.index = current_count + 1;
 379
 380                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 381                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 382                         if (acpi_processor_ffh_cstate_probe
 383                                         (pr->id, &cx, reg) == 0) {
 384                                 cx.entry_method = ACPI_CSTATE_FFH;
 385                         } else if (cx.type == ACPI_STATE_C1) {
 386                                 /*
 387                                  * C1 is a special case where FIXED_HARDWARE
 388                                  * can be handled in non-MWAIT way as well.
 389                                  * In that case, save this _CST entry info.
 390                                  * Otherwise, ignore this info and continue.
 391                                  */
 392                                 cx.entry_method = ACPI_CSTATE_HALT;
 393                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 394                         } else {
 395                                 continue;
 396                         }
 397                         if (cx.type == ACPI_STATE_C1 &&
 398                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 399                                 /*
 400                                  * In most cases the C1 space_id obtained from
 401                                  * _CST object is FIXED_HARDWARE access mode.
 402                                  * But when the option of idle=halt is added,
 403                                  * the entry_method type should be changed from
 404                                  * CSTATE_FFH to CSTATE_HALT.
 405                                  * When the option of idle=nomwait is added,
 406                                  * the C1 entry_method type should be
 407                                  * CSTATE_HALT.
 408                                  */
 409                                 cx.entry_method = ACPI_CSTATE_HALT;
 410                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 411                         }
 412                 } else {
 413                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 414                                  cx.address);
 415                 }
 416
 417                 if (cx.type == ACPI_STATE_C1) {
 418                         cx.valid = 1;
 419                 }
 420
 421                 obj = &(element->package.elements[2]);
 422                 if (obj->type != ACPI_TYPE_INTEGER)
 423                         continue;
 424
 425                 cx.latency = obj->integer.value;
 426
 427                 obj = &(element->package.elements[3]);
 428                 if (obj->type != ACPI_TYPE_INTEGER)
 429                         continue;
 430
 431                 current_count++;
 432                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 433
 434                 /*
 435                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 436                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 437                  */
 438                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 439                         pr_warn("Limiting number of power states to max (%d)\n",
 440                                 ACPI_PROCESSOR_MAX_POWER);
 441                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 442                         break;
 443                 }
 444         }
 445
 446         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 447                           current_count));
 448
 449         /* Validate number of power states discovered */
 450         if (current_count < 2)
 451                 ret = -EFAULT;
 452
 453       end:
 454         kfree(buffer.pointer);
 455
 456         return ret;
 457 }
 458
 459 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 460                                            struct acpi_processor_cx *cx)
 461 {
 462         static int bm_check_flag = -1;
 463         static int bm_control_flag = -1;
 464
 465
 466         if (!cx->address)
 467                 return;
 468
 469         /*
 470          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 471          * DMA transfers are used by any ISA device to avoid livelock.
 472          * Note that we could disable Type-F DMA (as recommended by
 473          * the erratum), but this is known to disrupt certain ISA
 474          * devices thus we take the conservative approach.
 475          */
 476         else if (errata.piix4.fdma) {
 477                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 478                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 479                 return;
 480         }
 481
 482         /* All the logic here assumes flags.bm_check is same across all CPUs */
 483         if (bm_check_flag == -1) {
 484                 /* Determine whether bm_check is needed based on CPU  */
 485                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 486                 bm_check_flag = pr->flags.bm_check;
 487                 bm_control_flag = pr->flags.bm_control;
 488         } else {
 489                 pr->flags.bm_check = bm_check_flag;
 490                 pr->flags.bm_control = bm_control_flag;
 491         }
 492
 493         if (pr->flags.bm_check) {
 494                 if (!pr->flags.bm_control) {
 495                         if (pr->flags.has_cst != 1) {
 496                                 /* bus mastering control is necessary */
 497                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 498                                         "C3 support requires BM control\n"));
 499                                 return;
 500                         } else {
 501                                 /* Here we enter C3 without bus mastering */
 502                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 503                                         "C3 support without BM control\n"));
 504                         }
 505                 }
 506         } else {
 507                 /*
 508                  * WBINVD should be set in fadt, for C3 state to be
 509                  * supported on when bm_check is not required.
 510                  */
 511                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 512                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 513                                           "Cache invalidation should work properly"
 514                                           " for C3 to be enabled on SMP systems\n"));
 515                         return;
 516                 }
 517         }
 518
 519         /*
 520          * Otherwise we've met all of our C3 requirements.
 521          * Normalize the C3 latency to expidite policy.  Enable
 522          * checking of bus mastering status (bm_check) so we can
 523          * use this in our C3 policy
 524          */
 525         cx->valid = 1;
 526
 527         /*
 528          * On older chipsets, BM_RLD needs to be set
 529          * in order for Bus Master activity to wake the
 530          * system from C3.  Newer chipsets handle DMA
 531          * during C3 automatically and BM_RLD is a NOP.
 532          * In either case, the proper way to
 533          * handle BM_RLD is to set it and leave it set.
 534          */
 535         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 536
 537         return;
 538 }
 539
 540 static int acpi_processor_power_verify(struct acpi_processor *pr)
 541 {
 542         unsigned int i;
 543         unsigned int working = 0;
 544
 545         pr->power.timer_broadcast_on_state = INT_MAX;
 546
 547         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 548                 struct acpi_processor_cx *cx = &pr->power.states[i];
 549
 550                 switch (cx->type) {
 551                 case ACPI_STATE_C1:
 552                         cx->valid = 1;
 553                         break;
 554
 555                 case ACPI_STATE_C2:
 556                         if (!cx->address)
 557                                 break;
 558                         cx->valid = 1;
 559                         break;
 560
 561                 case ACPI_STATE_C3:
 562                         acpi_processor_power_verify_c3(pr, cx);
 563                         break;
 564                 }
 565                 if (!cx->valid)
 566                         continue;
 567
 568                 lapic_timer_check_state(i, pr, cx);
 569                 tsc_check_state(cx->type);
 570                 working++;
 571         }
 572
 573         lapic_timer_propagate_broadcast(pr);
 574
 575         return (working);
 576 }
 577
 578 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 579 {
 580         unsigned int i;
 581         int result;
 582
 583
 584         /* NOTE: the idle thread may not be running while calling
 585          * this function */
 586
 587         /* Zero initialize all the C-states info. */
 588         memset(pr->power.states, 0, sizeof(pr->power.states));
 589
 590         result = acpi_processor_get_power_info_cst(pr);
 591         if (result == -ENODEV)
 592                 result = acpi_processor_get_power_info_fadt(pr);
 593
 594         if (result)
 595                 return result;
 596
 597         acpi_processor_get_power_info_default(pr);
 598
 599         pr->power.count = acpi_processor_power_verify(pr);
 600
 601         /*
 602          * if one state of type C2 or C3 is available, mark this
 603          * CPU as being "idle manageable"
 604          */
 605         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 606                 if (pr->power.states[i].valid) {
 607                         pr->power.count = i;
 608                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 609                                 pr->flags.power = 1;
 610                 }
 611         }
 612
 613         return 0;
 614 }
 615
 616 /**
 617  * acpi_idle_bm_check - checks if bus master activity was detected
 618  */
 619 static int acpi_idle_bm_check(void)
 620 {
 621         u32 bm_status = 0;
 622
 623         if (bm_check_disable)
 624                 return 0;
 625
 626         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 627         if (bm_status)
 628                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 629         /*
 630          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 631          * the true state of bus mastering activity; forcing us to
 632          * manually check the BMIDEA bit of each IDE channel.
 633          */
 634         else if (errata.piix4.bmisx) {
 635                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 636                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 637                         bm_status = 1;
 638         }
 639         return bm_status;
 640 }
 641
 642 /**
 643  * acpi_idle_do_entry - enter idle state using the appropriate method
 644  * @cx: cstate data
 645  *
 646  * Caller disables interrupt before call and enables interrupt after return.
 647  */
 648 static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 649 {
 650         if (cx->entry_method == ACPI_CSTATE_FFH) {
 651                 /* Call into architectural FFH based C-state */
 652                 acpi_processor_ffh_cstate_enter(cx);
 653         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 654                 acpi_safe_halt();
 655         } else {
 656                 /* IO port based C-state */
 657                 inb(cx->address);
 658                 /* Dummy wait op - must do something useless after P_LVL2 read
 659                    because chipsets cannot guarantee that STPCLK# signal
 660                    gets asserted in time to freeze execution properly. */
 661                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 662         }
 663 }
 664
 665 /**
 666  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 667  * @dev: the target CPU
 668  * @index: the index of suggested state
 669  */
 670 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 671 {
 672         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 673
 674         ACPI_FLUSH_CPU_CACHE();
 675
 676         while (1) {
 677
 678                 if (cx->entry_method == ACPI_CSTATE_HALT)
 679                         safe_halt();
 680                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 681                         inb(cx->address);
 682                         /* See comment in acpi_idle_do_entry() */
 683                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 684                 } else
 685                         return -ENODEV;
 686         }
 687
 688         /* Never reached */
 689         return 0;
 690 }
 691
 692 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 693 {
 694         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 695                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 696 }
 697
 698 static int c3_cpu_count;
 699 static DEFINE_RAW_SPINLOCK(c3_lock);
 700
 701 /**
 702  * acpi_idle_enter_bm - enters C3 with proper BM handling
 703  * @pr: Target processor
 704  * @cx: Target state context
 705  * @timer_bc: Whether or not to change timer mode to broadcast
 706  */
 707 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 708                                struct acpi_processor_cx *cx, bool timer_bc)
 709 {
 710         acpi_unlazy_tlb(smp_processor_id());
 711
 712         /*
 713          * Must be done before busmaster disable as we might need to
 714          * access HPET !
 715          */
 716         if (timer_bc)
 717                 lapic_timer_state_broadcast(pr, cx, 1);
 718
 719         /*
 720          * disable bus master
 721          * bm_check implies we need ARB_DIS
 722          * bm_control implies whether we can do ARB_DIS
 723          *
 724          * That leaves a case where bm_check is set and bm_control is
 725          * not set. In that case we cannot do much, we enter C3
 726          * without doing anything.
 727          */
 728         if (pr->flags.bm_control) {
 729                 raw_spin_lock(&c3_lock);
 730                 c3_cpu_count++;
 731                 /* Disable bus master arbitration when all CPUs are in C3 */
 732                 if (c3_cpu_count == num_online_cpus())
 733                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 734                 raw_spin_unlock(&c3_lock);
 735         }
 736
 737         acpi_idle_do_entry(cx);
 738
 739         /* Re-enable bus master arbitration */
 740         if (pr->flags.bm_control) {
 741                 raw_spin_lock(&c3_lock);
 742                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 743                 c3_cpu_count--;
 744                 raw_spin_unlock(&c3_lock);
 745         }
 746
 747         if (timer_bc)
 748                 lapic_timer_state_broadcast(pr, cx, 0);
 749 }
 750
 751 static int acpi_idle_enter(struct cpuidle_device *dev,
 752                            struct cpuidle_driver *drv, int index)
 753 {
 754         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 755         struct acpi_processor *pr;
 756
 757         pr = __this_cpu_read(processors);
 758         if (unlikely(!pr))
 759                 return -EINVAL;
 760
 761         if (cx->type != ACPI_STATE_C1) {
 762                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 763                         index = CPUIDLE_DRIVER_STATE_START;
 764                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 765                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 766                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 767                                 acpi_idle_enter_bm(pr, cx, true);
 768                                 return index;
 769                         } else if (drv->safe_state_index >= 0) {
 770                                 index = drv->safe_state_index;
 771                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 772                         } else {
 773                                 acpi_safe_halt();
 774                                 return -EBUSY;
 775                         }
 776                 }
 777         }
 778
 779         lapic_timer_state_broadcast(pr, cx, 1);
 780
 781         if (cx->type == ACPI_STATE_C3)
 782                 ACPI_FLUSH_CPU_CACHE();
 783
 784         acpi_idle_do_entry(cx);
 785
 786         lapic_timer_state_broadcast(pr, cx, 0);
 787
 788         return index;
 789 }
 790
 791 static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
 792                                    struct cpuidle_driver *drv, int index)
 793 {
 794         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 795
 796         if (cx->type == ACPI_STATE_C3) {
 797                 struct acpi_processor *pr = __this_cpu_read(processors);
 798
 799                 if (unlikely(!pr))
 800                         return;
 801
 802                 if (pr->flags.bm_check) {
 803                         acpi_idle_enter_bm(pr, cx, false);
 804                         return;
 805                 } else {
 806                         ACPI_FLUSH_CPU_CACHE();
 807                 }
 808         }
 809         acpi_idle_do_entry(cx);
 810 }
 811
 812 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 813                                            struct cpuidle_device *dev)
 814 {
 815         int i, count = CPUIDLE_DRIVER_STATE_START;
 816         struct acpi_processor_cx *cx;
 817
 818         if (max_cstate == 0)
 819                 max_cstate = 1;
 820
 821         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 822                 cx = &pr->power.states[i];
 823
 824                 if (!cx->valid)
 825                         continue;
 826
 827                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 828
 829                 count++;
 830                 if (count == CPUIDLE_STATE_MAX)
 831                         break;
 832         }
 833
 834         if (!count)
 835                 return -EINVAL;
 836
 837         return 0;
 838 }
 839
 840 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 841 {
 842         int i, count = CPUIDLE_DRIVER_STATE_START;
 843         struct acpi_processor_cx *cx;
 844         struct cpuidle_state *state;
 845         struct cpuidle_driver *drv = &acpi_idle_driver;
 846
 847         if (max_cstate == 0)
 848                 max_cstate = 1;
 849
 850         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 851                 cx = &pr->power.states[i];
 852
 853                 if (!cx->valid)
 854                         continue;
 855
 856                 state = &drv->states[count];
 857                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 858                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 859                 state->exit_latency = cx->latency;
 860                 state->target_residency = cx->latency * latency_factor;
 861                 state->enter = acpi_idle_enter;
 862
 863                 state->flags = 0;
 864                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 865                         state->enter_dead = acpi_idle_play_dead;
 866                         drv->safe_state_index = count;
 867                 }
 868                 /*
 869                  * Halt-induced C1 is not good for ->enter_freeze, because it
 870                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 871                  * particularly interesting from the suspend-to-idle angle, so
 872                  * avoid C1 and the situations in which we may need to fall back
 873                  * to it altogether.
 874                  */
 875                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 876                         state->enter_freeze = acpi_idle_enter_freeze;
 877
 878                 count++;
 879                 if (count == CPUIDLE_STATE_MAX)
 880                         break;
 881         }
 882
 883         drv->state_count = count;
 884
 885         if (!count)
 886                 return -EINVAL;
 887
 888         return 0;
 889 }
 890
 891 static inline void acpi_processor_cstate_first_run_checks(void)
 892 {
 893         acpi_status status;
 894         static int first_run;
 895
 896         if (first_run)
 897                 return;
 898         dmi_check_system(processor_power_dmi_table);
 899         max_cstate = acpi_processor_cstate_check(max_cstate);
 900         if (max_cstate < ACPI_C_STATES_MAX)
 901                 pr_notice("ACPI: processor limited to max C-state %d\n",
 902                           max_cstate);
 903         first_run++;
 904
 905         if (acpi_gbl_FADT.cst_control && !nocst) {
 906                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 907                                             acpi_gbl_FADT.cst_control, 8);
 908                 if (ACPI_FAILURE(status))
 909                         ACPI_EXCEPTION((AE_INFO, status,
 910                                         "Notifying BIOS of _CST ability failed"));
 911         }
 912 }
 913 #else
 914
 915 static inline int disabled_by_idle_boot_param(void) { return 0; }
 916 static inline void acpi_processor_cstate_first_run_checks(void) { }
 917 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 918 {
 919         return -ENODEV;
 920 }
 921
 922 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 923                                            struct cpuidle_device *dev)
 924 {
 925         return -EINVAL;
 926 }
 927
 928 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 929 {
 930         return -EINVAL;
 931 }
 932
 933 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 934
 935 struct acpi_lpi_states_array {
 936         unsigned int size;
 937         unsigned int composite_states_size;
 938         struct acpi_lpi_state *entries;
 939         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 940 };
 941
 942 static int obj_get_integer(union acpi_object *obj, u32 *value)
 943 {
 944         if (obj->type != ACPI_TYPE_INTEGER)
 945                 return -EINVAL;
 946
 947         *value = obj->integer.value;
 948         return 0;
 949 }
 950
 951 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 952                                        struct acpi_lpi_states_array *info)
 953 {
 954         acpi_status status;
 955         int ret = 0;
 956         int pkg_count, state_idx = 1, loop;
 957         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 958         union acpi_object *lpi_data;
 959         struct acpi_lpi_state *lpi_state;
 960
 961         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 962         if (ACPI_FAILURE(status)) {
 963                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 964                 return -ENODEV;
 965         }
 966
 967         lpi_data = buffer.pointer;
 968
 969         /* There must be at least 4 elements = 3 elements + 1 package */
 970         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 971             lpi_data->package.count < 4) {
 972                 pr_debug("not enough elements in _LPI\n");
 973                 ret = -ENODATA;
 974                 goto end;
 975         }
 976
 977         pkg_count = lpi_data->package.elements[2].integer.value;
 978
 979         /* Validate number of power states. */
 980         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 981                 pr_debug("count given by _LPI is not valid\n");
 982                 ret = -ENODATA;
 983                 goto end;
 984         }
 985
 986         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 987         if (!lpi_state) {
 988                 ret = -ENOMEM;
 989                 goto end;
 990         }
 991
 992         info->size = pkg_count;
 993         info->entries = lpi_state;
 994
 995         /* LPI States start at index 3 */
 996         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
 997                 union acpi_object *element, *pkg_elem, *obj;
 998
 999                 element = &lpi_data->package.elements[loop];
1000                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1001                         continue;
1002
1003                 pkg_elem = element->package.elements;
1004
1005                 obj = pkg_elem + 6;
1006                 if (obj->type == ACPI_TYPE_BUFFER) {
1007                         struct acpi_power_register *reg;
1008
1009                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1010                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1011                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1012                                 continue;
1013
1014                         lpi_state->address = reg->address;
1015                         lpi_state->entry_method =
1016                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1017                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1018                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1019                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1020                         lpi_state->address = obj->integer.value;
1021                 } else {
1022                         continue;
1023                 }
1024
1025                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1026
1027                 obj = pkg_elem + 9;
1028                 if (obj->type == ACPI_TYPE_STRING)
1029                         strlcpy(lpi_state->desc, obj->string.pointer,
1030                                 ACPI_CX_DESC_LEN);
1031
1032                 lpi_state->index = state_idx;
1033                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1034                         pr_debug("No min. residency found, assuming 10 us\n");
1035                         lpi_state->min_residency = 10;
1036                 }
1037
1038                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1039                         pr_debug("No wakeup residency found, assuming 10 us\n");
1040                         lpi_state->wake_latency = 10;
1041                 }
1042
1043                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1044                         lpi_state->flags = 0;
1045
1046                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1047                         lpi_state->arch_flags = 0;
1048
1049                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1050                         lpi_state->res_cnt_freq = 1;
1051
1052                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1053                         lpi_state->enable_parent_state = 0;
1054         }
1055
1056         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1057 end:
1058         kfree(buffer.pointer);
1059         return ret;
1060 }
1061
1062 /*
1063  * flat_state_cnt - the number of composite LPI states after the process of flattening
1064  */
1065 static int flat_state_cnt;
1066
1067 /**
1068  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1069  *
1070  * @local: local LPI state
1071  * @parent: parent LPI state
1072  * @result: composite LPI state
1073  */
1074 static bool combine_lpi_states(struct acpi_lpi_state *local,
1075                                struct acpi_lpi_state *parent,
1076                                struct acpi_lpi_state *result)
1077 {
1078         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1079                 if (!parent->address) /* 0 means autopromotable */
1080                         return false;
1081                 result->address = local->address + parent->address;
1082         } else {
1083                 result->address = parent->address;
1084         }
1085
1086         result->min_residency = max(local->min_residency, parent->min_residency);
1087         result->wake_latency = local->wake_latency + parent->wake_latency;
1088         result->enable_parent_state = parent->enable_parent_state;
1089         result->entry_method = local->entry_method;
1090
1091         result->flags = parent->flags;
1092         result->arch_flags = parent->arch_flags;
1093         result->index = parent->index;
1094
1095         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1096         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1097         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1098         return true;
1099 }
1100
1101 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1102
1103 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1104                                   struct acpi_lpi_state *t)
1105 {
1106         curr_level->composite_states[curr_level->composite_states_size++] = t;
1107 }
1108
1109 static int flatten_lpi_states(struct acpi_processor *pr,
1110                               struct acpi_lpi_states_array *curr_level,
1111                               struct acpi_lpi_states_array *prev_level)
1112 {
1113         int i, j, state_count = curr_level->size;
1114         struct acpi_lpi_state *p, *t = curr_level->entries;
1115
1116         curr_level->composite_states_size = 0;
1117         for (j = 0; j < state_count; j++, t++) {
1118                 struct acpi_lpi_state *flpi;
1119
1120                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1121                         continue;
1122
1123                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1124                         pr_warn("Limiting number of LPI states to max (%d)\n",
1125                                 ACPI_PROCESSOR_MAX_POWER);
1126                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1127                         break;
1128                 }
1129
1130                 flpi = &pr->power.lpi_states[flat_state_cnt];
1131
1132                 if (!prev_level) { /* leaf/processor node */
1133                         memcpy(flpi, t, sizeof(*t));
1134                         stash_composite_state(curr_level, flpi);
1135                         flat_state_cnt++;
1136                         continue;
1137                 }
1138
1139                 for (i = 0; i < prev_level->composite_states_size; i++) {
1140                         p = prev_level->composite_states[i];
1141                         if (t->index <= p->enable_parent_state &&
1142                             combine_lpi_states(p, t, flpi)) {
1143                                 stash_composite_state(curr_level, flpi);
1144                                 flat_state_cnt++;
1145                                 flpi++;
1146                         }
1147                 }
1148         }
1149
1150         kfree(curr_level->entries);
1151         return 0;
1152 }
1153
1154 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1155 {
1156         int ret, i;
1157         acpi_status status;
1158         acpi_handle handle = pr->handle, pr_ahandle;
1159         struct acpi_device *d = NULL;
1160         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1161
1162         if (!osc_pc_lpi_support_confirmed)
1163                 return -EOPNOTSUPP;
1164
1165         if (!acpi_has_method(handle, "_LPI"))
1166                 return -EINVAL;
1167
1168         flat_state_cnt = 0;
1169         prev = &info[0];
1170         curr = &info[1];
1171         handle = pr->handle;
1172         ret = acpi_processor_evaluate_lpi(handle, prev);
1173         if (ret)
1174                 return ret;
1175         flatten_lpi_states(pr, prev, NULL);
1176
1177         status = acpi_get_parent(handle, &pr_ahandle);
1178         while (ACPI_SUCCESS(status)) {
1179                 acpi_bus_get_device(pr_ahandle, &d);
1180                 handle = pr_ahandle;
1181
1182                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1183                         break;
1184
1185                 /* can be optional ? */
1186                 if (!acpi_has_method(handle, "_LPI"))
1187                         break;
1188
1189                 ret = acpi_processor_evaluate_lpi(handle, curr);
1190                 if (ret)
1191                         break;
1192
1193                 /* flatten all the LPI states in this level of hierarchy */
1194                 flatten_lpi_states(pr, curr, prev);
1195
1196                 tmp = prev, prev = curr, curr = tmp;
1197
1198                 status = acpi_get_parent(handle, &pr_ahandle);
1199         }
1200
1201         pr->power.count = flat_state_cnt;
1202         /* reset the index after flattening */
1203         for (i = 0; i < pr->power.count; i++)
1204                 pr->power.lpi_states[i].index = i;
1205
1206         /* Tell driver that _LPI is supported. */
1207         pr->flags.has_lpi = 1;
1208         pr->flags.power = 1;
1209
1210         return 0;
1211 }
1212
1213 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1214 {
1215         return -ENODEV;
1216 }
1217
1218 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1219 {
1220         return -ENODEV;
1221 }
1222
1223 /**
1224  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1225  * @dev: the target CPU
1226  * @drv: cpuidle driver containing cpuidle state info
1227  * @index: index of target state
1228  *
1229  * Return: 0 for success or negative value for error
1230  */
1231 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1232                                struct cpuidle_driver *drv, int index)
1233 {
1234         struct acpi_processor *pr;
1235         struct acpi_lpi_state *lpi;
1236
1237         pr = __this_cpu_read(processors);
1238
1239         if (unlikely(!pr))
1240                 return -EINVAL;
1241
1242         lpi = &pr->power.lpi_states[index];
1243         if (lpi->entry_method == ACPI_CSTATE_FFH)
1244                 return acpi_processor_ffh_lpi_enter(lpi);
1245
1246         return -EINVAL;
1247 }
1248
1249 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1250 {
1251         int i;
1252         struct acpi_lpi_state *lpi;
1253         struct cpuidle_state *state;
1254         struct cpuidle_driver *drv = &acpi_idle_driver;
1255
1256         if (!pr->flags.has_lpi)
1257                 return -EOPNOTSUPP;
1258
1259         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1260                 lpi = &pr->power.lpi_states[i];
1261
1262                 state = &drv->states[i];
1263                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1264                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1265                 state->exit_latency = lpi->wake_latency;
1266                 state->target_residency = lpi->min_residency;
1267                 if (lpi->arch_flags)
1268                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1269                 state->enter = acpi_idle_lpi_enter;
1270                 drv->safe_state_index = i;
1271         }
1272
1273         drv->state_count = i;
1274
1275         return 0;
1276 }
1277
1278 /**
1279  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1280  * global state data i.e. idle routines
1281  *
1282  * @pr: the ACPI processor
1283  */
1284 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1285 {
1286         int i;
1287         struct cpuidle_driver *drv = &acpi_idle_driver;
1288
1289         if (!pr->flags.power_setup_done || !pr->flags.power)
1290                 return -EINVAL;
1291
1292         drv->safe_state_index = -1;
1293         for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1294                 drv->states[i].name[0] = '\0';
1295                 drv->states[i].desc[0] = '\0';
1296         }
1297
1298         if (pr->flags.has_lpi)
1299                 return acpi_processor_setup_lpi_states(pr);
1300
1301         return acpi_processor_setup_cstates(pr);
1302 }
1303
1304 /**
1305  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1306  * device i.e. per-cpu data
1307  *
1308  * @pr: the ACPI processor
1309  * @dev : the cpuidle device
1310  */
1311 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1312                                             struct cpuidle_device *dev)
1313 {
1314         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1315                 return -EINVAL;
1316
1317         dev->cpu = pr->id;
1318         if (pr->flags.has_lpi)
1319                 return acpi_processor_ffh_lpi_probe(pr->id);
1320
1321         return acpi_processor_setup_cpuidle_cx(pr, dev);
1322 }
1323
1324 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1325 {
1326         int ret;
1327
1328         ret = acpi_processor_get_lpi_info(pr);
1329         if (ret)
1330                 ret = acpi_processor_get_cstate_info(pr);
1331
1332         return ret;
1333 }
1334
1335 int acpi_processor_hotplug(struct acpi_processor *pr)
1336 {
1337         int ret = 0;
1338         struct cpuidle_device *dev;
1339
1340         if (disabled_by_idle_boot_param())
1341                 return 0;
1342
1343         if (!pr->flags.power_setup_done)
1344                 return -ENODEV;
1345
1346         dev = per_cpu(acpi_cpuidle_device, pr->id);
1347         cpuidle_pause_and_lock();
1348         cpuidle_disable_device(dev);
1349         ret = acpi_processor_get_power_info(pr);
1350         if (!ret && pr->flags.power) {
1351                 acpi_processor_setup_cpuidle_dev(pr, dev);
1352                 ret = cpuidle_enable_device(dev);
1353         }
1354         cpuidle_resume_and_unlock();
1355
1356         return ret;
1357 }
1358
1359 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1360 {
1361         int cpu;
1362         struct acpi_processor *_pr;
1363         struct cpuidle_device *dev;
1364
1365         if (disabled_by_idle_boot_param())
1366                 return 0;
1367
1368         if (!pr->flags.power_setup_done)
1369                 return -ENODEV;
1370
1371         /*
1372          * FIXME:  Design the ACPI notification to make it once per
1373          * system instead of once per-cpu.  This condition is a hack
1374          * to make the code that updates C-States be called once.
1375          */
1376
1377         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1378
1379                 /* Protect against cpu-hotplug */
1380                 get_online_cpus();
1381                 cpuidle_pause_and_lock();
1382
1383                 /* Disable all cpuidle devices */
1384                 for_each_online_cpu(cpu) {
1385                         _pr = per_cpu(processors, cpu);
1386                         if (!_pr || !_pr->flags.power_setup_done)
1387                                 continue;
1388                         dev = per_cpu(acpi_cpuidle_device, cpu);
1389                         cpuidle_disable_device(dev);
1390                 }
1391
1392                 /* Populate Updated C-state information */
1393                 acpi_processor_get_power_info(pr);
1394                 acpi_processor_setup_cpuidle_states(pr);
1395
1396                 /* Enable 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                         acpi_processor_get_power_info(_pr);
1402                         if (_pr->flags.power) {
1403                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1404                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1405                                 cpuidle_enable_device(dev);
1406                         }
1407                 }
1408                 cpuidle_resume_and_unlock();
1409                 put_online_cpus();
1410         }
1411
1412         return 0;
1413 }
1414
1415 static int acpi_processor_registered;
1416
1417 int acpi_processor_power_init(struct acpi_processor *pr)
1418 {
1419         int retval;
1420         struct cpuidle_device *dev;
1421
1422         if (disabled_by_idle_boot_param())
1423                 return 0;
1424
1425         acpi_processor_cstate_first_run_checks();
1426
1427         if (!acpi_processor_get_power_info(pr))
1428                 pr->flags.power_setup_done = 1;
1429
1430         /*
1431          * Install the idle handler if processor power management is supported.
1432          * Note that we use previously set idle handler will be used on
1433          * platforms that only support C1.
1434          */
1435         if (pr->flags.power) {
1436                 /* Register acpi_idle_driver if not already registered */
1437                 if (!acpi_processor_registered) {
1438                         acpi_processor_setup_cpuidle_states(pr);
1439                         retval = cpuidle_register_driver(&acpi_idle_driver);
1440                         if (retval)
1441                                 return retval;
1442                         pr_debug("%s registered with cpuidle\n",
1443                                  acpi_idle_driver.name);
1444                 }
1445
1446                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1447                 if (!dev)
1448                         return -ENOMEM;
1449                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1450
1451                 acpi_processor_setup_cpuidle_dev(pr, dev);
1452
1453                 /* Register per-cpu cpuidle_device. Cpuidle driver
1454                  * must already be registered before registering device
1455                  */
1456                 retval = cpuidle_register_device(dev);
1457                 if (retval) {
1458                         if (acpi_processor_registered == 0)
1459                                 cpuidle_unregister_driver(&acpi_idle_driver);
1460                         return retval;
1461                 }
1462                 acpi_processor_registered++;
1463         }
1464         return 0;
1465 }
1466
1467 int acpi_processor_power_exit(struct acpi_processor *pr)
1468 {
1469         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1470
1471         if (disabled_by_idle_boot_param())
1472                 return 0;
1473
1474         if (pr->flags.power) {
1475                 cpuidle_unregister_device(dev);
1476                 acpi_processor_registered--;
1477                 if (acpi_processor_registered == 0)
1478                         cpuidle_unregister_driver(&acpi_idle_driver);
1479         }
1480
1481         pr->flags.power_setup_done = 0;
1482         return 0;
1483 }