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  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/slab.h>
  36 #include <linux/acpi.h>
  37 #include <linux/dmi.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/sched.h>        /* need_resched() */
  40 #include <linux/pm_qos.h>
  41 #include <linux/clockchips.h>
  42 #include <linux/cpuidle.h>
  43 #include <linux/irqflags.h>
  44
  45 /*
  46  * Include the apic definitions for x86 to have the APIC timer related defines
  47  * available also for UP (on SMP it gets magically included via linux/smp.h).
  48  * asm/acpi.h is not an option, as it would require more include magic. Also
  49  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  50  */
  51 #ifdef CONFIG_X86
  52 #include <asm/apic.h>
  53 #endif
  54
  55 #include <asm/io.h>
  56 #include <asm/uaccess.h>
  57
  58 #include <acpi/acpi_bus.h>
  59 #include <acpi/processor.h>
  60 #include <asm/processor.h>
  61
  62 #define PREFIX "ACPI: "
  63
  64 #define ACPI_PROCESSOR_CLASS            "processor"
  65 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  66 ACPI_MODULE_NAME("processor_idle");
  67 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  68 #define C2_OVERHEAD                     1       /* 1us */
  69 #define C3_OVERHEAD                     1       /* 1us */
  70 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  71
  72 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  73 module_param(max_cstate, uint, 0000);
  74 static unsigned int nocst __read_mostly;
  75 module_param(nocst, uint, 0000);
  76 static int bm_check_disable __read_mostly;
  77 module_param(bm_check_disable, uint, 0000);
  78
  79 static unsigned int latency_factor __read_mostly = 2;
  80 module_param(latency_factor, uint, 0644);
  81
  82 static int disabled_by_idle_boot_param(void)
  83 {
  84         return boot_option_idle_override == IDLE_POLL ||
  85                 boot_option_idle_override == IDLE_FORCE_MWAIT ||
  86                 boot_option_idle_override == IDLE_HALT;
  87 }
  88
  89 /*
  90  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  91  * For now disable this. Probably a bug somewhere else.
  92  *
  93  * To skip this limit, boot/load with a large max_cstate limit.
  94  */
  95 static int set_max_cstate(const struct dmi_system_id *id)
  96 {
  97         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  98                 return 0;
  99
 100         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
 101                " Override with \"processor.max_cstate=%d\"\n", id->ident,
 102                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 103
 104         max_cstate = (long)id->driver_data;
 105
 106         return 0;
 107 }
 108
 109 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 110    callers to only run once -AK */
 111 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 112         { set_max_cstate, "Clevo 5600D", {
 113           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 114           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 115          (void *)2},
 116         { set_max_cstate, "Pavilion zv5000", {
 117           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 118           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 119          (void *)1},
 120         { set_max_cstate, "Asus L8400B", {
 121           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 122           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 123          (void *)1},
 124         {},
 125 };
 126
 127
 128 /*
 129  * Callers should disable interrupts before the call and enable
 130  * interrupts after return.
 131  */
 132 static void acpi_safe_halt(void)
 133 {
 134         current_thread_info()->status &= ~TS_POLLING;
 135         /*
 136          * TS_POLLING-cleared state must be visible before we
 137          * test NEED_RESCHED:
 138          */
 139         smp_mb();
 140         if (!need_resched()) {
 141                 safe_halt();
 142                 local_irq_disable();
 143         }
 144         current_thread_info()->status |= TS_POLLING;
 145 }
 146
 147 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 148
 149 /*
 150  * Some BIOS implementations switch to C3 in the published C2 state.
 151  * This seems to be a common problem on AMD boxen, but other vendors
 152  * are affected too. We pick the most conservative approach: we assume
 153  * that the local APIC stops in both C2 and C3.
 154  */
 155 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 156                                    struct acpi_processor_cx *cx)
 157 {
 158         struct acpi_processor_power *pwr = &pr->power;
 159         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 160
 161         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 162                 return;
 163
 164         if (amd_e400_c1e_detected)
 165                 type = ACPI_STATE_C1;
 166
 167         /*
 168          * Check, if one of the previous states already marked the lapic
 169          * unstable
 170          */
 171         if (pwr->timer_broadcast_on_state < state)
 172                 return;
 173
 174         if (cx->type >= type)
 175                 pr->power.timer_broadcast_on_state = state;
 176 }
 177
 178 static void __lapic_timer_propagate_broadcast(void *arg)
 179 {
 180         struct acpi_processor *pr = (struct acpi_processor *) arg;
 181         unsigned long reason;
 182
 183         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 184                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 185
 186         clockevents_notify(reason, &pr->id);
 187 }
 188
 189 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 190 {
 191         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 192                                  (void *)pr, 1);
 193 }
 194
 195 /* Power(C) State timer broadcast control */
 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 197                                        struct acpi_processor_cx *cx,
 198                                        int broadcast)
 199 {
 200         int state = cx - pr->power.states;
 201
 202         if (state >= pr->power.timer_broadcast_on_state) {
 203                 unsigned long reason;
 204
 205                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 206                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 207                 clockevents_notify(reason, &pr->id);
 208         }
 209 }
 210
 211 #else
 212
 213 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 214                                    struct acpi_processor_cx *cstate) { }
 215 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 216 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 217                                        struct acpi_processor_cx *cx,
 218                                        int broadcast)
 219 {
 220 }
 221
 222 #endif
 223
 224 static u32 saved_bm_rld;
 225
 226 static void acpi_idle_bm_rld_save(void)
 227 {
 228         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 229 }
 230 static void acpi_idle_bm_rld_restore(void)
 231 {
 232         u32 resumed_bm_rld;
 233
 234         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 235
 236         if (resumed_bm_rld != saved_bm_rld)
 237                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 238 }
 239
 240 int acpi_processor_suspend(struct device *dev)
 241 {
 242         acpi_idle_bm_rld_save();
 243         return 0;
 244 }
 245
 246 int acpi_processor_resume(struct device *dev)
 247 {
 248         acpi_idle_bm_rld_restore();
 249         return 0;
 250 }
 251
 252 #if defined(CONFIG_X86)
 253 static void tsc_check_state(int state)
 254 {
 255         switch (boot_cpu_data.x86_vendor) {
 256         case X86_VENDOR_AMD:
 257         case X86_VENDOR_INTEL:
 258                 /*
 259                  * AMD Fam10h TSC will tick in all
 260                  * C/P/S0/S1 states when this bit is set.
 261                  */
 262                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 263                         return;
 264
 265                 /*FALL THROUGH*/
 266         default:
 267                 /* TSC could halt in idle, so notify users */
 268                 if (state > ACPI_STATE_C1)
 269                         mark_tsc_unstable("TSC halts in idle");
 270         }
 271 }
 272 #else
 273 static void tsc_check_state(int state) { return; }
 274 #endif
 275
 276 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 277 {
 278
 279         if (!pr)
 280                 return -EINVAL;
 281
 282         if (!pr->pblk)
 283                 return -ENODEV;
 284
 285         /* if info is obtained from pblk/fadt, type equals state */
 286         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 287         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 288
 289 #ifndef CONFIG_HOTPLUG_CPU
 290         /*
 291          * Check for P_LVL2_UP flag before entering C2 and above on
 292          * an SMP system.
 293          */
 294         if ((num_online_cpus() > 1) &&
 295             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 296                 return -ENODEV;
 297 #endif
 298
 299         /* determine C2 and C3 address from pblk */
 300         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 301         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 302
 303         /* determine latencies from FADT */
 304         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 305         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 306
 307         /*
 308          * FADT specified C2 latency must be less than or equal to
 309          * 100 microseconds.
 310          */
 311         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 312                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 313                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 314                 /* invalidate C2 */
 315                 pr->power.states[ACPI_STATE_C2].address = 0;
 316         }
 317
 318         /*
 319          * FADT supplied C3 latency must be less than or equal to
 320          * 1000 microseconds.
 321          */
 322         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 323                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 324                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 325                 /* invalidate C3 */
 326                 pr->power.states[ACPI_STATE_C3].address = 0;
 327         }
 328
 329         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 330                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 331                           pr->power.states[ACPI_STATE_C2].address,
 332                           pr->power.states[ACPI_STATE_C3].address));
 333
 334         return 0;
 335 }
 336
 337 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 338 {
 339         if (!pr->power.states[ACPI_STATE_C1].valid) {
 340                 /* set the first C-State to C1 */
 341                 /* all processors need to support C1 */
 342                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 343                 pr->power.states[ACPI_STATE_C1].valid = 1;
 344                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 345         }
 346         /* the C0 state only exists as a filler in our array */
 347         pr->power.states[ACPI_STATE_C0].valid = 1;
 348         return 0;
 349 }
 350
 351 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 352 {
 353         acpi_status status = 0;
 354         u64 count;
 355         int current_count;
 356         int i;
 357         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 358         union acpi_object *cst;
 359
 360
 361         if (nocst)
 362                 return -ENODEV;
 363
 364         current_count = 0;
 365
 366         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 367         if (ACPI_FAILURE(status)) {
 368                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 369                 return -ENODEV;
 370         }
 371
 372         cst = buffer.pointer;
 373
 374         /* There must be at least 2 elements */
 375         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 376                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 377                 status = -EFAULT;
 378                 goto end;
 379         }
 380
 381         count = cst->package.elements[0].integer.value;
 382
 383         /* Validate number of power states. */
 384         if (count < 1 || count != cst->package.count - 1) {
 385                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 386                 status = -EFAULT;
 387                 goto end;
 388         }
 389
 390         /* Tell driver that at least _CST is supported. */
 391         pr->flags.has_cst = 1;
 392
 393         for (i = 1; i <= count; i++) {
 394                 union acpi_object *element;
 395                 union acpi_object *obj;
 396                 struct acpi_power_register *reg;
 397                 struct acpi_processor_cx cx;
 398
 399                 memset(&cx, 0, sizeof(cx));
 400
 401                 element = &(cst->package.elements[i]);
 402                 if (element->type != ACPI_TYPE_PACKAGE)
 403                         continue;
 404
 405                 if (element->package.count != 4)
 406                         continue;
 407
 408                 obj = &(element->package.elements[0]);
 409
 410                 if (obj->type != ACPI_TYPE_BUFFER)
 411                         continue;
 412
 413                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 414
 415                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 416                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 417                         continue;
 418
 419                 /* There should be an easy way to extract an integer... */
 420                 obj = &(element->package.elements[1]);
 421                 if (obj->type != ACPI_TYPE_INTEGER)
 422                         continue;
 423
 424                 cx.type = obj->integer.value;
 425                 /*
 426                  * Some buggy BIOSes won't list C1 in _CST -
 427                  * Let acpi_processor_get_power_info_default() handle them later
 428                  */
 429                 if (i == 1 && cx.type != ACPI_STATE_C1)
 430                         current_count++;
 431
 432                 cx.address = reg->address;
 433                 cx.index = current_count + 1;
 434
 435                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 436                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 437                         if (acpi_processor_ffh_cstate_probe
 438                                         (pr->id, &cx, reg) == 0) {
 439                                 cx.entry_method = ACPI_CSTATE_FFH;
 440                         } else if (cx.type == ACPI_STATE_C1) {
 441                                 /*
 442                                  * C1 is a special case where FIXED_HARDWARE
 443                                  * can be handled in non-MWAIT way as well.
 444                                  * In that case, save this _CST entry info.
 445                                  * Otherwise, ignore this info and continue.
 446                                  */
 447                                 cx.entry_method = ACPI_CSTATE_HALT;
 448                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 449                         } else {
 450                                 continue;
 451                         }
 452                         if (cx.type == ACPI_STATE_C1 &&
 453                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 454                                 /*
 455                                  * In most cases the C1 space_id obtained from
 456                                  * _CST object is FIXED_HARDWARE access mode.
 457                                  * But when the option of idle=halt is added,
 458                                  * the entry_method type should be changed from
 459                                  * CSTATE_FFH to CSTATE_HALT.
 460                                  * When the option of idle=nomwait is added,
 461                                  * the C1 entry_method type should be
 462                                  * CSTATE_HALT.
 463                                  */
 464                                 cx.entry_method = ACPI_CSTATE_HALT;
 465                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 466                         }
 467                 } else {
 468                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 469                                  cx.address);
 470                 }
 471
 472                 if (cx.type == ACPI_STATE_C1) {
 473                         cx.valid = 1;
 474                 }
 475
 476                 obj = &(element->package.elements[2]);
 477                 if (obj->type != ACPI_TYPE_INTEGER)
 478                         continue;
 479
 480                 cx.latency = obj->integer.value;
 481
 482                 obj = &(element->package.elements[3]);
 483                 if (obj->type != ACPI_TYPE_INTEGER)
 484                         continue;
 485
 486                 cx.power = obj->integer.value;
 487
 488                 current_count++;
 489                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 490
 491                 /*
 492                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 493                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 494                  */
 495                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 496                         printk(KERN_WARNING
 497                                "Limiting number of power states to max (%d)\n",
 498                                ACPI_PROCESSOR_MAX_POWER);
 499                         printk(KERN_WARNING
 500                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 501                         break;
 502                 }
 503         }
 504
 505         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 506                           current_count));
 507
 508         /* Validate number of power states discovered */
 509         if (current_count < 2)
 510                 status = -EFAULT;
 511
 512       end:
 513         kfree(buffer.pointer);
 514
 515         return status;
 516 }
 517
 518 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 519                                            struct acpi_processor_cx *cx)
 520 {
 521         static int bm_check_flag = -1;
 522         static int bm_control_flag = -1;
 523
 524
 525         if (!cx->address)
 526                 return;
 527
 528         /*
 529          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 530          * DMA transfers are used by any ISA device to avoid livelock.
 531          * Note that we could disable Type-F DMA (as recommended by
 532          * the erratum), but this is known to disrupt certain ISA
 533          * devices thus we take the conservative approach.
 534          */
 535         else if (errata.piix4.fdma) {
 536                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 537                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 538                 return;
 539         }
 540
 541         /* All the logic here assumes flags.bm_check is same across all CPUs */
 542         if (bm_check_flag == -1) {
 543                 /* Determine whether bm_check is needed based on CPU  */
 544                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 545                 bm_check_flag = pr->flags.bm_check;
 546                 bm_control_flag = pr->flags.bm_control;
 547         } else {
 548                 pr->flags.bm_check = bm_check_flag;
 549                 pr->flags.bm_control = bm_control_flag;
 550         }
 551
 552         if (pr->flags.bm_check) {
 553                 if (!pr->flags.bm_control) {
 554                         if (pr->flags.has_cst != 1) {
 555                                 /* bus mastering control is necessary */
 556                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 557                                         "C3 support requires BM control\n"));
 558                                 return;
 559                         } else {
 560                                 /* Here we enter C3 without bus mastering */
 561                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 562                                         "C3 support without BM control\n"));
 563                         }
 564                 }
 565         } else {
 566                 /*
 567                  * WBINVD should be set in fadt, for C3 state to be
 568                  * supported on when bm_check is not required.
 569                  */
 570                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 571                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 572                                           "Cache invalidation should work properly"
 573                                           " for C3 to be enabled on SMP systems\n"));
 574                         return;
 575                 }
 576         }
 577
 578         /*
 579          * Otherwise we've met all of our C3 requirements.
 580          * Normalize the C3 latency to expidite policy.  Enable
 581          * checking of bus mastering status (bm_check) so we can
 582          * use this in our C3 policy
 583          */
 584         cx->valid = 1;
 585
 586         /*
 587          * On older chipsets, BM_RLD needs to be set
 588          * in order for Bus Master activity to wake the
 589          * system from C3.  Newer chipsets handle DMA
 590          * during C3 automatically and BM_RLD is a NOP.
 591          * In either case, the proper way to
 592          * handle BM_RLD is to set it and leave it set.
 593          */
 594         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 595
 596         return;
 597 }
 598
 599 static int acpi_processor_power_verify(struct acpi_processor *pr)
 600 {
 601         unsigned int i;
 602         unsigned int working = 0;
 603
 604         pr->power.timer_broadcast_on_state = INT_MAX;
 605
 606         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 607                 struct acpi_processor_cx *cx = &pr->power.states[i];
 608
 609                 switch (cx->type) {
 610                 case ACPI_STATE_C1:
 611                         cx->valid = 1;
 612                         break;
 613
 614                 case ACPI_STATE_C2:
 615                         if (!cx->address)
 616                                 break;
 617                         cx->valid = 1;
 618                         break;
 619
 620                 case ACPI_STATE_C3:
 621                         acpi_processor_power_verify_c3(pr, cx);
 622                         break;
 623                 }
 624                 if (!cx->valid)
 625                         continue;
 626
 627                 lapic_timer_check_state(i, pr, cx);
 628                 tsc_check_state(cx->type);
 629                 working++;
 630         }
 631
 632         lapic_timer_propagate_broadcast(pr);
 633
 634         return (working);
 635 }
 636
 637 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 638 {
 639         unsigned int i;
 640         int result;
 641
 642
 643         /* NOTE: the idle thread may not be running while calling
 644          * this function */
 645
 646         /* Zero initialize all the C-states info. */
 647         memset(pr->power.states, 0, sizeof(pr->power.states));
 648
 649         result = acpi_processor_get_power_info_cst(pr);
 650         if (result == -ENODEV)
 651                 result = acpi_processor_get_power_info_fadt(pr);
 652
 653         if (result)
 654                 return result;
 655
 656         acpi_processor_get_power_info_default(pr);
 657
 658         pr->power.count = acpi_processor_power_verify(pr);
 659
 660         /*
 661          * if one state of type C2 or C3 is available, mark this
 662          * CPU as being "idle manageable"
 663          */
 664         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 665                 if (pr->power.states[i].valid) {
 666                         pr->power.count = i;
 667                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 668                                 pr->flags.power = 1;
 669                 }
 670         }
 671
 672         return 0;
 673 }
 674
 675 /**
 676  * acpi_idle_bm_check - checks if bus master activity was detected
 677  */
 678 static int acpi_idle_bm_check(void)
 679 {
 680         u32 bm_status = 0;
 681
 682         if (bm_check_disable)
 683                 return 0;
 684
 685         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 686         if (bm_status)
 687                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 688         /*
 689          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 690          * the true state of bus mastering activity; forcing us to
 691          * manually check the BMIDEA bit of each IDE channel.
 692          */
 693         else if (errata.piix4.bmisx) {
 694                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 695                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 696                         bm_status = 1;
 697         }
 698         return bm_status;
 699 }
 700
 701 /**
 702  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 703  * @cx: cstate data
 704  *
 705  * Caller disables interrupt before call and enables interrupt after return.
 706  */
 707 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 708 {
 709         /* Don't trace irqs off for idle */
 710         stop_critical_timings();
 711         if (cx->entry_method == ACPI_CSTATE_FFH) {
 712                 /* Call into architectural FFH based C-state */
 713                 acpi_processor_ffh_cstate_enter(cx);
 714         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 715                 acpi_safe_halt();
 716         } else {
 717                 /* IO port based C-state */
 718                 inb(cx->address);
 719                 /* Dummy wait op - must do something useless after P_LVL2 read
 720                    because chipsets cannot guarantee that STPCLK# signal
 721                    gets asserted in time to freeze execution properly. */
 722                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 723         }
 724         start_critical_timings();
 725 }
 726
 727 /**
 728  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 729  * @dev: the target CPU
 730  * @drv: cpuidle driver containing cpuidle state info
 731  * @index: index of target state
 732  *
 733  * This is equivalent to the HALT instruction.
 734  */
 735 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 736                 struct cpuidle_driver *drv, int index)
 737 {
 738         ktime_t  kt1, kt2;
 739         s64 idle_time;
 740         struct acpi_processor *pr;
 741         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 742         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 743
 744         pr = __this_cpu_read(processors);
 745         dev->last_residency = 0;
 746
 747         if (unlikely(!pr))
 748                 return -EINVAL;
 749
 750         local_irq_disable();
 751
 752
 753         lapic_timer_state_broadcast(pr, cx, 1);
 754         kt1 = ktime_get_real();
 755         acpi_idle_do_entry(cx);
 756         kt2 = ktime_get_real();
 757         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 758
 759         /* Update device last_residency*/
 760         dev->last_residency = (int)idle_time;
 761
 762         local_irq_enable();
 763         lapic_timer_state_broadcast(pr, cx, 0);
 764
 765         return index;
 766 }
 767
 768
 769 /**
 770  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 771  * @dev: the target CPU
 772  * @index: the index of suggested state
 773  */
 774 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 775 {
 776         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 777         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 778
 779         ACPI_FLUSH_CPU_CACHE();
 780
 781         while (1) {
 782
 783                 if (cx->entry_method == ACPI_CSTATE_HALT)
 784                         safe_halt();
 785                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 786                         inb(cx->address);
 787                         /* See comment in acpi_idle_do_entry() */
 788                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 789                 } else
 790                         return -ENODEV;
 791         }
 792
 793         /* Never reached */
 794         return 0;
 795 }
 796
 797 /**
 798  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 799  * @dev: the target CPU
 800  * @drv: cpuidle driver with cpuidle state information
 801  * @index: the index of suggested state
 802  */
 803 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 804                 struct cpuidle_driver *drv, int index)
 805 {
 806         struct acpi_processor *pr;
 807         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 808         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 809         ktime_t  kt1, kt2;
 810         s64 idle_time_ns;
 811         s64 idle_time;
 812
 813         pr = __this_cpu_read(processors);
 814         dev->last_residency = 0;
 815
 816         if (unlikely(!pr))
 817                 return -EINVAL;
 818
 819         local_irq_disable();
 820
 821
 822         if (cx->entry_method != ACPI_CSTATE_FFH) {
 823                 current_thread_info()->status &= ~TS_POLLING;
 824                 /*
 825                  * TS_POLLING-cleared state must be visible before we test
 826                  * NEED_RESCHED:
 827                  */
 828                 smp_mb();
 829
 830                 if (unlikely(need_resched())) {
 831                         current_thread_info()->status |= TS_POLLING;
 832                         local_irq_enable();
 833                         return -EINVAL;
 834                 }
 835         }
 836
 837         /*
 838          * Must be done before busmaster disable as we might need to
 839          * access HPET !
 840          */
 841         lapic_timer_state_broadcast(pr, cx, 1);
 842
 843         if (cx->type == ACPI_STATE_C3)
 844                 ACPI_FLUSH_CPU_CACHE();
 845
 846         kt1 = ktime_get_real();
 847         /* Tell the scheduler that we are going deep-idle: */
 848         sched_clock_idle_sleep_event();
 849         acpi_idle_do_entry(cx);
 850         kt2 = ktime_get_real();
 851         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
 852         idle_time = idle_time_ns;
 853         do_div(idle_time, NSEC_PER_USEC);
 854
 855         /* Update device last_residency*/
 856         dev->last_residency = (int)idle_time;
 857
 858         /* Tell the scheduler how much we idled: */
 859         sched_clock_idle_wakeup_event(idle_time_ns);
 860
 861         local_irq_enable();
 862         if (cx->entry_method != ACPI_CSTATE_FFH)
 863                 current_thread_info()->status |= TS_POLLING;
 864
 865         lapic_timer_state_broadcast(pr, cx, 0);
 866         return index;
 867 }
 868
 869 static int c3_cpu_count;
 870 static DEFINE_RAW_SPINLOCK(c3_lock);
 871
 872 /**
 873  * acpi_idle_enter_bm - enters C3 with proper BM handling
 874  * @dev: the target CPU
 875  * @drv: cpuidle driver containing state data
 876  * @index: the index of suggested state
 877  *
 878  * If BM is detected, the deepest non-C3 idle state is entered instead.
 879  */
 880 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 881                 struct cpuidle_driver *drv, int index)
 882 {
 883         struct acpi_processor *pr;
 884         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 885         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 886         ktime_t  kt1, kt2;
 887         s64 idle_time_ns;
 888         s64 idle_time;
 889
 890
 891         pr = __this_cpu_read(processors);
 892         dev->last_residency = 0;
 893
 894         if (unlikely(!pr))
 895                 return -EINVAL;
 896
 897         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 898                 if (drv->safe_state_index >= 0) {
 899                         return drv->states[drv->safe_state_index].enter(dev,
 900                                                 drv, drv->safe_state_index);
 901                 } else {
 902                         local_irq_disable();
 903                         acpi_safe_halt();
 904                         local_irq_enable();
 905                         return -EBUSY;
 906                 }
 907         }
 908
 909         local_irq_disable();
 910
 911
 912         if (cx->entry_method != ACPI_CSTATE_FFH) {
 913                 current_thread_info()->status &= ~TS_POLLING;
 914                 /*
 915                  * TS_POLLING-cleared state must be visible before we test
 916                  * NEED_RESCHED:
 917                  */
 918                 smp_mb();
 919
 920                 if (unlikely(need_resched())) {
 921                         current_thread_info()->status |= TS_POLLING;
 922                         local_irq_enable();
 923                         return -EINVAL;
 924                 }
 925         }
 926
 927         acpi_unlazy_tlb(smp_processor_id());
 928
 929         /* Tell the scheduler that we are going deep-idle: */
 930         sched_clock_idle_sleep_event();
 931         /*
 932          * Must be done before busmaster disable as we might need to
 933          * access HPET !
 934          */
 935         lapic_timer_state_broadcast(pr, cx, 1);
 936
 937         kt1 = ktime_get_real();
 938         /*
 939          * disable bus master
 940          * bm_check implies we need ARB_DIS
 941          * !bm_check implies we need cache flush
 942          * bm_control implies whether we can do ARB_DIS
 943          *
 944          * That leaves a case where bm_check is set and bm_control is
 945          * not set. In that case we cannot do much, we enter C3
 946          * without doing anything.
 947          */
 948         if (pr->flags.bm_check && pr->flags.bm_control) {
 949                 raw_spin_lock(&c3_lock);
 950                 c3_cpu_count++;
 951                 /* Disable bus master arbitration when all CPUs are in C3 */
 952                 if (c3_cpu_count == num_online_cpus())
 953                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 954                 raw_spin_unlock(&c3_lock);
 955         } else if (!pr->flags.bm_check) {
 956                 ACPI_FLUSH_CPU_CACHE();
 957         }
 958
 959         acpi_idle_do_entry(cx);
 960
 961         /* Re-enable bus master arbitration */
 962         if (pr->flags.bm_check && pr->flags.bm_control) {
 963                 raw_spin_lock(&c3_lock);
 964                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 965                 c3_cpu_count--;
 966                 raw_spin_unlock(&c3_lock);
 967         }
 968         kt2 = ktime_get_real();
 969         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
 970         idle_time = idle_time_ns;
 971         do_div(idle_time, NSEC_PER_USEC);
 972
 973         /* Update device last_residency*/
 974         dev->last_residency = (int)idle_time;
 975
 976         /* Tell the scheduler how much we idled: */
 977         sched_clock_idle_wakeup_event(idle_time_ns);
 978
 979         local_irq_enable();
 980         if (cx->entry_method != ACPI_CSTATE_FFH)
 981                 current_thread_info()->status |= TS_POLLING;
 982
 983         lapic_timer_state_broadcast(pr, cx, 0);
 984         return index;
 985 }
 986
 987 struct cpuidle_driver acpi_idle_driver = {
 988         .name =         "acpi_idle",
 989         .owner =        THIS_MODULE,
 990 };
 991
 992 /**
 993  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
 994  * device i.e. per-cpu data
 995  *
 996  * @pr: the ACPI processor
 997  */
 998 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
 999 {
1000         int i, count = CPUIDLE_DRIVER_STATE_START;
1001         struct acpi_processor_cx *cx;
1002         struct cpuidle_state_usage *state_usage;
1003         struct cpuidle_device *dev = &pr->power.dev;
1004
1005         if (!pr->flags.power_setup_done)
1006                 return -EINVAL;
1007
1008         if (pr->flags.power == 0) {
1009                 return -EINVAL;
1010         }
1011
1012         dev->cpu = pr->id;
1013
1014         if (max_cstate == 0)
1015                 max_cstate = 1;
1016
1017         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1018                 cx = &pr->power.states[i];
1019                 state_usage = &dev->states_usage[count];
1020
1021                 if (!cx->valid)
1022                         continue;
1023
1024 #ifdef CONFIG_HOTPLUG_CPU
1025                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1026                     !pr->flags.has_cst &&
1027                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1028                         continue;
1029 #endif
1030
1031                 cpuidle_set_statedata(state_usage, cx);
1032
1033                 count++;
1034                 if (count == CPUIDLE_STATE_MAX)
1035                         break;
1036         }
1037
1038         dev->state_count = count;
1039
1040         if (!count)
1041                 return -EINVAL;
1042
1043         return 0;
1044 }
1045
1046 /**
1047  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
1048  * global state data i.e. idle routines
1049  *
1050  * @pr: the ACPI processor
1051  */
1052 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1053 {
1054         int i, count = CPUIDLE_DRIVER_STATE_START;
1055         struct acpi_processor_cx *cx;
1056         struct cpuidle_state *state;
1057         struct cpuidle_driver *drv = &acpi_idle_driver;
1058
1059         if (!pr->flags.power_setup_done)
1060                 return -EINVAL;
1061
1062         if (pr->flags.power == 0)
1063                 return -EINVAL;
1064
1065         drv->safe_state_index = -1;
1066         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1067                 drv->states[i].name[0] = '\0';
1068                 drv->states[i].desc[0] = '\0';
1069         }
1070
1071         if (max_cstate == 0)
1072                 max_cstate = 1;
1073
1074         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1075                 cx = &pr->power.states[i];
1076
1077                 if (!cx->valid)
1078                         continue;
1079
1080 #ifdef CONFIG_HOTPLUG_CPU
1081                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1082                     !pr->flags.has_cst &&
1083                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1084                         continue;
1085 #endif
1086
1087                 state = &drv->states[count];
1088                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1089                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1090                 state->exit_latency = cx->latency;
1091                 state->target_residency = cx->latency * latency_factor;
1092
1093                 state->flags = 0;
1094                 switch (cx->type) {
1095                         case ACPI_STATE_C1:
1096                         if (cx->entry_method == ACPI_CSTATE_FFH)
1097                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1098
1099                         state->enter = acpi_idle_enter_c1;
1100                         state->enter_dead = acpi_idle_play_dead;
1101                         drv->safe_state_index = count;
1102                         break;
1103
1104                         case ACPI_STATE_C2:
1105                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1106                         state->enter = acpi_idle_enter_simple;
1107                         state->enter_dead = acpi_idle_play_dead;
1108                         drv->safe_state_index = count;
1109                         break;
1110
1111                         case ACPI_STATE_C3:
1112                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1113                         state->enter = pr->flags.bm_check ?
1114                                         acpi_idle_enter_bm :
1115                                         acpi_idle_enter_simple;
1116                         break;
1117                 }
1118
1119                 count++;
1120                 if (count == CPUIDLE_STATE_MAX)
1121                         break;
1122         }
1123
1124         drv->state_count = count;
1125
1126         if (!count)
1127                 return -EINVAL;
1128
1129         return 0;
1130 }
1131
1132 int acpi_processor_hotplug(struct acpi_processor *pr)
1133 {
1134         int ret = 0;
1135
1136         if (disabled_by_idle_boot_param())
1137                 return 0;
1138
1139         if (!pr)
1140                 return -EINVAL;
1141
1142         if (nocst) {
1143                 return -ENODEV;
1144         }
1145
1146         if (!pr->flags.power_setup_done)
1147                 return -ENODEV;
1148
1149         cpuidle_pause_and_lock();
1150         cpuidle_disable_device(&pr->power.dev);
1151         acpi_processor_get_power_info(pr);
1152         if (pr->flags.power) {
1153                 acpi_processor_setup_cpuidle_cx(pr);
1154                 ret = cpuidle_enable_device(&pr->power.dev);
1155         }
1156         cpuidle_resume_and_unlock();
1157
1158         return ret;
1159 }
1160
1161 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1162 {
1163         int cpu;
1164         struct acpi_processor *_pr;
1165
1166         if (disabled_by_idle_boot_param())
1167                 return 0;
1168
1169         if (!pr)
1170                 return -EINVAL;
1171
1172         if (nocst)
1173                 return -ENODEV;
1174
1175         if (!pr->flags.power_setup_done)
1176                 return -ENODEV;
1177
1178         /*
1179          * FIXME:  Design the ACPI notification to make it once per
1180          * system instead of once per-cpu.  This condition is a hack
1181          * to make the code that updates C-States be called once.
1182          */
1183
1184         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1185
1186                 cpuidle_pause_and_lock();
1187                 /* Protect against cpu-hotplug */
1188                 get_online_cpus();
1189
1190                 /* Disable all cpuidle devices */
1191                 for_each_online_cpu(cpu) {
1192                         _pr = per_cpu(processors, cpu);
1193                         if (!_pr || !_pr->flags.power_setup_done)
1194                                 continue;
1195                         cpuidle_disable_device(&_pr->power.dev);
1196                 }
1197
1198                 /* Populate Updated C-state information */
1199                 acpi_processor_setup_cpuidle_states(pr);
1200
1201                 /* Enable all cpuidle devices */
1202                 for_each_online_cpu(cpu) {
1203                         _pr = per_cpu(processors, cpu);
1204                         if (!_pr || !_pr->flags.power_setup_done)
1205                                 continue;
1206                         acpi_processor_get_power_info(_pr);
1207                         if (_pr->flags.power) {
1208                                 acpi_processor_setup_cpuidle_cx(_pr);
1209                                 cpuidle_enable_device(&_pr->power.dev);
1210                         }
1211                 }
1212                 put_online_cpus();
1213                 cpuidle_resume_and_unlock();
1214         }
1215
1216         return 0;
1217 }
1218
1219 static int acpi_processor_registered;
1220
1221 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1222                               struct acpi_device *device)
1223 {
1224         acpi_status status = 0;
1225         int retval;
1226         static int first_run;
1227
1228         if (disabled_by_idle_boot_param())
1229                 return 0;
1230
1231         if (!first_run) {
1232                 dmi_check_system(processor_power_dmi_table);
1233                 max_cstate = acpi_processor_cstate_check(max_cstate);
1234                 if (max_cstate < ACPI_C_STATES_MAX)
1235                         printk(KERN_NOTICE
1236                                "ACPI: processor limited to max C-state %d\n",
1237                                max_cstate);
1238                 first_run++;
1239         }
1240
1241         if (!pr)
1242                 return -EINVAL;
1243
1244         if (acpi_gbl_FADT.cst_control && !nocst) {
1245                 status =
1246                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1247                 if (ACPI_FAILURE(status)) {
1248                         ACPI_EXCEPTION((AE_INFO, status,
1249                                         "Notifying BIOS of _CST ability failed"));
1250                 }
1251         }
1252
1253         acpi_processor_get_power_info(pr);
1254         pr->flags.power_setup_done = 1;
1255
1256         /*
1257          * Install the idle handler if processor power management is supported.
1258          * Note that we use previously set idle handler will be used on
1259          * platforms that only support C1.
1260          */
1261         if (pr->flags.power) {
1262                 /* Register acpi_idle_driver if not already registered */
1263                 if (!acpi_processor_registered) {
1264                         acpi_processor_setup_cpuidle_states(pr);
1265                         retval = cpuidle_register_driver(&acpi_idle_driver);
1266                         if (retval)
1267                                 return retval;
1268                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1269                                         acpi_idle_driver.name);
1270                 }
1271                 /* Register per-cpu cpuidle_device. Cpuidle driver
1272                  * must already be registered before registering device
1273                  */
1274                 acpi_processor_setup_cpuidle_cx(pr);
1275                 retval = cpuidle_register_device(&pr->power.dev);
1276                 if (retval) {
1277                         if (acpi_processor_registered == 0)
1278                                 cpuidle_unregister_driver(&acpi_idle_driver);
1279                         return retval;
1280                 }
1281                 acpi_processor_registered++;
1282         }
1283         return 0;
1284 }
1285
1286 int acpi_processor_power_exit(struct acpi_processor *pr,
1287                               struct acpi_device *device)
1288 {
1289         if (disabled_by_idle_boot_param())
1290                 return 0;
1291
1292         if (pr->flags.power) {
1293                 cpuidle_unregister_device(&pr->power.dev);
1294                 acpi_processor_registered--;
1295                 if (acpi_processor_registered == 0)
1296                         cpuidle_unregister_driver(&acpi_idle_driver);
1297         }
1298
1299         pr->flags.power_setup_done = 0;
1300         return 0;
1301 }