git.oblomov.eu Git - linux-2.6/blob - 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/proc_fs.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/acpi.h>
  38 #include <linux/dmi.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>        /* need_resched() */
  41 #include <linux/pm_qos_params.h>
  42 #include <linux/clockchips.h>
  43 #include <linux/cpuidle.h>
  44 #include <linux/irqflags.h>
  45
  46 /*
  47  * Include the apic definitions for x86 to have the APIC timer related defines
  48  * available also for UP (on SMP it gets magically included via linux/smp.h).
  49  * asm/acpi.h is not an option, as it would require more include magic. Also
  50  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  51  */
  52 #ifdef CONFIG_X86
  53 #include <asm/apic.h>
  54 #endif
  55
  56 #include <asm/io.h>
  57 #include <asm/uaccess.h>
  58
  59 #include <acpi/acpi_bus.h>
  60 #include <acpi/processor.h>
  61 #include <asm/processor.h>
  62
  63 #define ACPI_PROCESSOR_CLASS            "processor"
  64 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  65 ACPI_MODULE_NAME("processor_idle");
  66 #define ACPI_PROCESSOR_FILE_POWER       "power"
  67 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
  68 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  69 #ifndef CONFIG_CPU_IDLE
  70 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
  71 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
  72 static void (*pm_idle_save) (void) __read_mostly;
  73 #else
  74 #define C2_OVERHEAD                     1       /* 1us */
  75 #define C3_OVERHEAD                     1       /* 1us */
  76 #endif
  77 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  78
  79 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  80 #ifdef CONFIG_CPU_IDLE
  81 module_param(max_cstate, uint, 0000);
  82 #else
  83 module_param(max_cstate, uint, 0644);
  84 #endif
  85 static unsigned int nocst __read_mostly;
  86 module_param(nocst, uint, 0000);
  87
  88 #ifndef CONFIG_CPU_IDLE
  89 /*
  90  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
  91  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
  92  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
  93  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
  94  * reduce history for more aggressive entry into C3
  95  */
  96 static unsigned int bm_history __read_mostly =
  97     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
  98 module_param(bm_history, uint, 0644);
  99
 100 static int acpi_processor_set_power_policy(struct acpi_processor *pr);
 101
 102 #else   /* CONFIG_CPU_IDLE */
 103 static unsigned int latency_factor __read_mostly = 2;
 104 module_param(latency_factor, uint, 0644);
 105 #endif
 106
 107 /*
 108  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
 109  * For now disable this. Probably a bug somewhere else.
 110  *
 111  * To skip this limit, boot/load with a large max_cstate limit.
 112  */
 113 static int set_max_cstate(const struct dmi_system_id *id)
 114 {
 115         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
 116                 return 0;
 117
 118         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
 119                " Override with \"processor.max_cstate=%d\"\n", id->ident,
 120                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 121
 122         max_cstate = (long)id->driver_data;
 123
 124         return 0;
 125 }
 126
 127 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 128    callers to only run once -AK */
 129 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 130         { set_max_cstate, "IBM ThinkPad R40e", {
 131           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 132           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
 133         { set_max_cstate, "IBM ThinkPad R40e", {
 134           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 135           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
 136         { set_max_cstate, "IBM ThinkPad R40e", {
 137           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 138           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
 139         { set_max_cstate, "IBM ThinkPad R40e", {
 140           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 141           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
 142         { set_max_cstate, "IBM ThinkPad R40e", {
 143           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 144           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
 145         { set_max_cstate, "IBM ThinkPad R40e", {
 146           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 147           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
 148         { set_max_cstate, "IBM ThinkPad R40e", {
 149           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 150           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
 151         { set_max_cstate, "IBM ThinkPad R40e", {
 152           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 153           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
 154         { set_max_cstate, "IBM ThinkPad R40e", {
 155           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 156           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
 157         { set_max_cstate, "IBM ThinkPad R40e", {
 158           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 159           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
 160         { set_max_cstate, "IBM ThinkPad R40e", {
 161           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 162           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
 163         { set_max_cstate, "IBM ThinkPad R40e", {
 164           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 165           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
 166         { set_max_cstate, "IBM ThinkPad R40e", {
 167           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 168           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
 169         { set_max_cstate, "IBM ThinkPad R40e", {
 170           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 171           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
 172         { set_max_cstate, "IBM ThinkPad R40e", {
 173           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 174           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
 175         { set_max_cstate, "IBM ThinkPad R40e", {
 176           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 177           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
 178         { set_max_cstate, "Medion 41700", {
 179           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 180           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
 181         { set_max_cstate, "Clevo 5600D", {
 182           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 183           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 184          (void *)2},
 185         {},
 186 };
 187
 188 static inline u32 ticks_elapsed(u32 t1, u32 t2)
 189 {
 190         if (t2 >= t1)
 191                 return (t2 - t1);
 192         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 193                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 194         else
 195                 return ((0xFFFFFFFF - t1) + t2);
 196 }
 197
 198 static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
 199 {
 200         if (t2 >= t1)
 201                 return PM_TIMER_TICKS_TO_US(t2 - t1);
 202         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 203                 return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 204         else
 205                 return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
 206 }
 207
 208 /*
 209  * Callers should disable interrupts before the call and enable
 210  * interrupts after return.
 211  */
 212 static void acpi_safe_halt(void)
 213 {
 214         current_thread_info()->status &= ~TS_POLLING;
 215         /*
 216          * TS_POLLING-cleared state must be visible before we
 217          * test NEED_RESCHED:
 218          */
 219         smp_mb();
 220         if (!need_resched()) {
 221                 safe_halt();
 222                 local_irq_disable();
 223         }
 224         current_thread_info()->status |= TS_POLLING;
 225 }
 226
 227 #ifndef CONFIG_CPU_IDLE
 228
 229 static void
 230 acpi_processor_power_activate(struct acpi_processor *pr,
 231                               struct acpi_processor_cx *new)
 232 {
 233         struct acpi_processor_cx *old;
 234
 235         if (!pr || !new)
 236                 return;
 237
 238         old = pr->power.state;
 239
 240         if (old)
 241                 old->promotion.count = 0;
 242         new->demotion.count = 0;
 243
 244         /* Cleanup from old state. */
 245         if (old) {
 246                 switch (old->type) {
 247                 case ACPI_STATE_C3:
 248                         /* Disable bus master reload */
 249                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
 250                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
 251                         break;
 252                 }
 253         }
 254
 255         /* Prepare to use new state. */
 256         switch (new->type) {
 257         case ACPI_STATE_C3:
 258                 /* Enable bus master reload */
 259                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
 260                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 261                 break;
 262         }
 263
 264         pr->power.state = new;
 265
 266         return;
 267 }
 268
 269 static atomic_t c3_cpu_count;
 270
 271 /* Common C-state entry for C2, C3, .. */
 272 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
 273 {
 274         /* Don't trace irqs off for idle */
 275         stop_critical_timings();
 276         if (cstate->entry_method == ACPI_CSTATE_FFH) {
 277                 /* Call into architectural FFH based C-state */
 278                 acpi_processor_ffh_cstate_enter(cstate);
 279         } else {
 280                 int unused;
 281                 /* IO port based C-state */
 282                 inb(cstate->address);
 283                 /* Dummy wait op - must do something useless after P_LVL2 read
 284                    because chipsets cannot guarantee that STPCLK# signal
 285                    gets asserted in time to freeze execution properly. */
 286                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 287         }
 288         start_critical_timings();
 289 }
 290 #endif /* !CONFIG_CPU_IDLE */
 291
 292 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 293
 294 /*
 295  * Some BIOS implementations switch to C3 in the published C2 state.
 296  * This seems to be a common problem on AMD boxen, but other vendors
 297  * are affected too. We pick the most conservative approach: we assume
 298  * that the local APIC stops in both C2 and C3.
 299  */
 300 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 301                                    struct acpi_processor_cx *cx)
 302 {
 303         struct acpi_processor_power *pwr = &pr->power;
 304         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 305
 306         /*
 307          * Check, if one of the previous states already marked the lapic
 308          * unstable
 309          */
 310         if (pwr->timer_broadcast_on_state < state)
 311                 return;
 312
 313         if (cx->type >= type)
 314                 pr->power.timer_broadcast_on_state = state;
 315 }
 316
 317 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
 318 {
 319         unsigned long reason;
 320
 321         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 322                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 323
 324         clockevents_notify(reason, &pr->id);
 325 }
 326
 327 /* Power(C) State timer broadcast control */
 328 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 329                                        struct acpi_processor_cx *cx,
 330                                        int broadcast)
 331 {
 332         int state = cx - pr->power.states;
 333
 334         if (state >= pr->power.timer_broadcast_on_state) {
 335                 unsigned long reason;
 336
 337                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 338                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 339                 clockevents_notify(reason, &pr->id);
 340         }
 341 }
 342
 343 #else
 344
 345 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 346                                    struct acpi_processor_cx *cstate) { }
 347 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
 348 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 349                                        struct acpi_processor_cx *cx,
 350                                        int broadcast)
 351 {
 352 }
 353
 354 #endif
 355
 356 /*
 357  * Suspend / resume control
 358  */
 359 static int acpi_idle_suspend;
 360
 361 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 362 {
 363         acpi_idle_suspend = 1;
 364         return 0;
 365 }
 366
 367 int acpi_processor_resume(struct acpi_device * device)
 368 {
 369         acpi_idle_suspend = 0;
 370         return 0;
 371 }
 372
 373 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 374 static int tsc_halts_in_c(int state)
 375 {
 376         switch (boot_cpu_data.x86_vendor) {
 377         case X86_VENDOR_AMD:
 378         case X86_VENDOR_INTEL:
 379                 /*
 380                  * AMD Fam10h TSC will tick in all
 381                  * C/P/S0/S1 states when this bit is set.
 382                  */
 383                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 384                         return 0;
 385
 386                 /*FALL THROUGH*/
 387         default:
 388                 return state > ACPI_STATE_C1;
 389         }
 390 }
 391 #endif
 392
 393 #ifndef CONFIG_CPU_IDLE
 394 static void acpi_processor_idle(void)
 395 {
 396         struct acpi_processor *pr = NULL;
 397         struct acpi_processor_cx *cx = NULL;
 398         struct acpi_processor_cx *next_state = NULL;
 399         int sleep_ticks = 0;
 400         u32 t1, t2 = 0;
 401
 402         /*
 403          * Interrupts must be disabled during bus mastering calculations and
 404          * for C2/C3 transitions.
 405          */
 406         local_irq_disable();
 407
 408         pr = __get_cpu_var(processors);
 409         if (!pr) {
 410                 local_irq_enable();
 411                 return;
 412         }
 413
 414         /*
 415          * Check whether we truly need to go idle, or should
 416          * reschedule:
 417          */
 418         if (unlikely(need_resched())) {
 419                 local_irq_enable();
 420                 return;
 421         }
 422
 423         cx = pr->power.state;
 424         if (!cx || acpi_idle_suspend) {
 425                 if (pm_idle_save) {
 426                         pm_idle_save(); /* enables IRQs */
 427                 } else {
 428                         acpi_safe_halt();
 429                         local_irq_enable();
 430                 }
 431
 432                 return;
 433         }
 434
 435         /*
 436          * Check BM Activity
 437          * -----------------
 438          * Check for bus mastering activity (if required), record, and check
 439          * for demotion.
 440          */
 441         if (pr->flags.bm_check) {
 442                 u32 bm_status = 0;
 443                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
 444
 445                 if (diff > 31)
 446                         diff = 31;
 447
 448                 pr->power.bm_activity <<= diff;
 449
 450                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 451                 if (bm_status) {
 452                         pr->power.bm_activity |= 0x1;
 453                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 454                 }
 455                 /*
 456                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 457                  * the true state of bus mastering activity; forcing us to
 458                  * manually check the BMIDEA bit of each IDE channel.
 459                  */
 460                 else if (errata.piix4.bmisx) {
 461                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 462                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 463                                 pr->power.bm_activity |= 0x1;
 464                 }
 465
 466                 pr->power.bm_check_timestamp = jiffies;
 467
 468                 /*
 469                  * If bus mastering is or was active this jiffy, demote
 470                  * to avoid a faulty transition.  Note that the processor
 471                  * won't enter a low-power state during this call (to this
 472                  * function) but should upon the next.
 473                  *
 474                  * TBD: A better policy might be to fallback to the demotion
 475                  *      state (use it for this quantum only) istead of
 476                  *      demoting -- and rely on duration as our sole demotion
 477                  *      qualification.  This may, however, introduce DMA
 478                  *      issues (e.g. floppy DMA transfer overrun/underrun).
 479                  */
 480                 if ((pr->power.bm_activity & 0x1) &&
 481                     cx->demotion.threshold.bm) {
 482                         local_irq_enable();
 483                         next_state = cx->demotion.state;
 484                         goto end;
 485                 }
 486         }
 487
 488 #ifdef CONFIG_HOTPLUG_CPU
 489         /*
 490          * Check for P_LVL2_UP flag before entering C2 and above on
 491          * an SMP system. We do it here instead of doing it at _CST/P_LVL
 492          * detection phase, to work cleanly with logical CPU hotplug.
 493          */
 494         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 495             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 496                 cx = &pr->power.states[ACPI_STATE_C1];
 497 #endif
 498
 499         /*
 500          * Sleep:
 501          * ------
 502          * Invoke the current Cx state to put the processor to sleep.
 503          */
 504         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
 505                 current_thread_info()->status &= ~TS_POLLING;
 506                 /*
 507                  * TS_POLLING-cleared state must be visible before we
 508                  * test NEED_RESCHED:
 509                  */
 510                 smp_mb();
 511                 if (need_resched()) {
 512                         current_thread_info()->status |= TS_POLLING;
 513                         local_irq_enable();
 514                         return;
 515                 }
 516         }
 517
 518         switch (cx->type) {
 519
 520         case ACPI_STATE_C1:
 521                 /*
 522                  * Invoke C1.
 523                  * Use the appropriate idle routine, the one that would
 524                  * be used without acpi C-states.
 525                  */
 526                 if (pm_idle_save) {
 527                         pm_idle_save(); /* enables IRQs */
 528                 } else {
 529                         acpi_safe_halt();
 530                         local_irq_enable();
 531                 }
 532
 533                 /*
 534                  * TBD: Can't get time duration while in C1, as resumes
 535                  *      go to an ISR rather than here.  Need to instrument
 536                  *      base interrupt handler.
 537                  *
 538                  * Note: the TSC better not stop in C1, sched_clock() will
 539                  *       skew otherwise.
 540                  */
 541                 sleep_ticks = 0xFFFFFFFF;
 542
 543                 break;
 544
 545         case ACPI_STATE_C2:
 546                 /* Get start time (ticks) */
 547                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 548                 /* Tell the scheduler that we are going deep-idle: */
 549                 sched_clock_idle_sleep_event();
 550                 /* Invoke C2 */
 551                 acpi_state_timer_broadcast(pr, cx, 1);
 552                 acpi_cstate_enter(cx);
 553                 /* Get end time (ticks) */
 554                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 555
 556 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 557                 /* TSC halts in C2, so notify users */
 558                 if (tsc_halts_in_c(ACPI_STATE_C2))
 559                         mark_tsc_unstable("possible TSC halt in C2");
 560 #endif
 561                 /* Compute time (ticks) that we were actually asleep */
 562                 sleep_ticks = ticks_elapsed(t1, t2);
 563
 564                 /* Tell the scheduler how much we idled: */
 565                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 566
 567                 /* Re-enable interrupts */
 568                 local_irq_enable();
 569                 /* Do not account our idle-switching overhead: */
 570                 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
 571
 572                 current_thread_info()->status |= TS_POLLING;
 573                 acpi_state_timer_broadcast(pr, cx, 0);
 574                 break;
 575
 576         case ACPI_STATE_C3:
 577                 acpi_unlazy_tlb(smp_processor_id());
 578                 /*
 579                  * Must be done before busmaster disable as we might
 580                  * need to access HPET !
 581                  */
 582                 acpi_state_timer_broadcast(pr, cx, 1);
 583                 /*
 584                  * disable bus master
 585                  * bm_check implies we need ARB_DIS
 586                  * !bm_check implies we need cache flush
 587                  * bm_control implies whether we can do ARB_DIS
 588                  *
 589                  * That leaves a case where bm_check is set and bm_control is
 590                  * not set. In that case we cannot do much, we enter C3
 591                  * without doing anything.
 592                  */
 593                 if (pr->flags.bm_check && pr->flags.bm_control) {
 594                         if (atomic_inc_return(&c3_cpu_count) ==
 595                             num_online_cpus()) {
 596                                 /*
 597                                  * All CPUs are trying to go to C3
 598                                  * Disable bus master arbitration
 599                                  */
 600                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
 601                         }
 602                 } else if (!pr->flags.bm_check) {
 603                         /* SMP with no shared cache... Invalidate cache  */
 604                         ACPI_FLUSH_CPU_CACHE();
 605                 }
 606
 607                 /* Get start time (ticks) */
 608                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 609                 /* Invoke C3 */
 610                 /* Tell the scheduler that we are going deep-idle: */
 611                 sched_clock_idle_sleep_event();
 612                 acpi_cstate_enter(cx);
 613                 /* Get end time (ticks) */
 614                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 615                 if (pr->flags.bm_check && pr->flags.bm_control) {
 616                         /* Enable bus master arbitration */
 617                         atomic_dec(&c3_cpu_count);
 618                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
 619                 }
 620
 621 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 622                 /* TSC halts in C3, so notify users */
 623                 if (tsc_halts_in_c(ACPI_STATE_C3))
 624                         mark_tsc_unstable("TSC halts in C3");
 625 #endif
 626                 /* Compute time (ticks) that we were actually asleep */
 627                 sleep_ticks = ticks_elapsed(t1, t2);
 628                 /* Tell the scheduler how much we idled: */
 629                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 630
 631                 /* Re-enable interrupts */
 632                 local_irq_enable();
 633                 /* Do not account our idle-switching overhead: */
 634                 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
 635
 636                 current_thread_info()->status |= TS_POLLING;
 637                 acpi_state_timer_broadcast(pr, cx, 0);
 638                 break;
 639
 640         default:
 641                 local_irq_enable();
 642                 return;
 643         }
 644         cx->usage++;
 645         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
 646                 cx->time += sleep_ticks;
 647
 648         next_state = pr->power.state;
 649
 650 #ifdef CONFIG_HOTPLUG_CPU
 651         /* Don't do promotion/demotion */
 652         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 653             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
 654                 next_state = cx;
 655                 goto end;
 656         }
 657 #endif
 658
 659         /*
 660          * Promotion?
 661          * ----------
 662          * Track the number of longs (time asleep is greater than threshold)
 663          * and promote when the count threshold is reached.  Note that bus
 664          * mastering activity may prevent promotions.
 665          * Do not promote above max_cstate.
 666          */
 667         if (cx->promotion.state &&
 668             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
 669                 if (sleep_ticks > cx->promotion.threshold.ticks &&
 670                   cx->promotion.state->latency <=
 671                                 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
 672                         cx->promotion.count++;
 673                         cx->demotion.count = 0;
 674                         if (cx->promotion.count >=
 675                             cx->promotion.threshold.count) {
 676                                 if (pr->flags.bm_check) {
 677                                         if (!
 678                                             (pr->power.bm_activity & cx->
 679                                              promotion.threshold.bm)) {
 680                                                 next_state =
 681                                                     cx->promotion.state;
 682                                                 goto end;
 683                                         }
 684                                 } else {
 685                                         next_state = cx->promotion.state;
 686                                         goto end;
 687                                 }
 688                         }
 689                 }
 690         }
 691
 692         /*
 693          * Demotion?
 694          * ---------
 695          * Track the number of shorts (time asleep is less than time threshold)
 696          * and demote when the usage threshold is reached.
 697          */
 698         if (cx->demotion.state) {
 699                 if (sleep_ticks < cx->demotion.threshold.ticks) {
 700                         cx->demotion.count++;
 701                         cx->promotion.count = 0;
 702                         if (cx->demotion.count >= cx->demotion.threshold.count) {
 703                                 next_state = cx->demotion.state;
 704                                 goto end;
 705                         }
 706                 }
 707         }
 708
 709       end:
 710         /*
 711          * Demote if current state exceeds max_cstate
 712          * or if the latency of the current state is unacceptable
 713          */
 714         if ((pr->power.state - pr->power.states) > max_cstate ||
 715                 pr->power.state->latency >
 716                                 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
 717                 if (cx->demotion.state)
 718                         next_state = cx->demotion.state;
 719         }
 720
 721         /*
 722          * New Cx State?
 723          * -------------
 724          * If we're going to start using a new Cx state we must clean up
 725          * from the previous and prepare to use the new.
 726          */
 727         if (next_state != pr->power.state)
 728                 acpi_processor_power_activate(pr, next_state);
 729 }
 730
 731 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
 732 {
 733         unsigned int i;
 734         unsigned int state_is_set = 0;
 735         struct acpi_processor_cx *lower = NULL;
 736         struct acpi_processor_cx *higher = NULL;
 737         struct acpi_processor_cx *cx;
 738
 739
 740         if (!pr)
 741                 return -EINVAL;
 742
 743         /*
 744          * This function sets the default Cx state policy (OS idle handler).
 745          * Our scheme is to promote quickly to C2 but more conservatively
 746          * to C3.  We're favoring C2  for its characteristics of low latency
 747          * (quick response), good power savings, and ability to allow bus
 748          * mastering activity.  Note that the Cx state policy is completely
 749          * customizable and can be altered dynamically.
 750          */
 751
 752         /* startup state */
 753         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 754                 cx = &pr->power.states[i];
 755                 if (!cx->valid)
 756                         continue;
 757
 758                 if (!state_is_set)
 759                         pr->power.state = cx;
 760                 state_is_set++;
 761                 break;
 762         }
 763
 764         if (!state_is_set)
 765                 return -ENODEV;
 766
 767         /* demotion */
 768         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 769                 cx = &pr->power.states[i];
 770                 if (!cx->valid)
 771                         continue;
 772
 773                 if (lower) {
 774                         cx->demotion.state = lower;
 775                         cx->demotion.threshold.ticks = cx->latency_ticks;
 776                         cx->demotion.threshold.count = 1;
 777                         if (cx->type == ACPI_STATE_C3)
 778                                 cx->demotion.threshold.bm = bm_history;
 779                 }
 780
 781                 lower = cx;
 782         }
 783
 784         /* promotion */
 785         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
 786                 cx = &pr->power.states[i];
 787                 if (!cx->valid)
 788                         continue;
 789
 790                 if (higher) {
 791                         cx->promotion.state = higher;
 792                         cx->promotion.threshold.ticks = cx->latency_ticks;
 793                         if (cx->type >= ACPI_STATE_C2)
 794                                 cx->promotion.threshold.count = 4;
 795                         else
 796                                 cx->promotion.threshold.count = 10;
 797                         if (higher->type == ACPI_STATE_C3)
 798                                 cx->promotion.threshold.bm = bm_history;
 799                 }
 800
 801                 higher = cx;
 802         }
 803
 804         return 0;
 805 }
 806 #endif /* !CONFIG_CPU_IDLE */
 807
 808 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 809 {
 810
 811         if (!pr)
 812                 return -EINVAL;
 813
 814         if (!pr->pblk)
 815                 return -ENODEV;
 816
 817         /* if info is obtained from pblk/fadt, type equals state */
 818         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 819         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 820
 821 #ifndef CONFIG_HOTPLUG_CPU
 822         /*
 823          * Check for P_LVL2_UP flag before entering C2 and above on
 824          * an SMP system.
 825          */
 826         if ((num_online_cpus() > 1) &&
 827             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 828                 return -ENODEV;
 829 #endif
 830
 831         /* determine C2 and C3 address from pblk */
 832         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 833         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 834
 835         /* determine latencies from FADT */
 836         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 837         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 838
 839         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 840                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 841                           pr->power.states[ACPI_STATE_C2].address,
 842                           pr->power.states[ACPI_STATE_C3].address));
 843
 844         return 0;
 845 }
 846
 847 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 848 {
 849         if (!pr->power.states[ACPI_STATE_C1].valid) {
 850                 /* set the first C-State to C1 */
 851                 /* all processors need to support C1 */
 852                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 853                 pr->power.states[ACPI_STATE_C1].valid = 1;
 854                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 855         }
 856         /* the C0 state only exists as a filler in our array */
 857         pr->power.states[ACPI_STATE_C0].valid = 1;
 858         return 0;
 859 }
 860
 861 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 862 {
 863         acpi_status status = 0;
 864         acpi_integer count;
 865         int current_count;
 866         int i;
 867         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 868         union acpi_object *cst;
 869
 870
 871         if (nocst)
 872                 return -ENODEV;
 873
 874         current_count = 0;
 875
 876         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 877         if (ACPI_FAILURE(status)) {
 878                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 879                 return -ENODEV;
 880         }
 881
 882         cst = buffer.pointer;
 883
 884         /* There must be at least 2 elements */
 885         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 886                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 887                 status = -EFAULT;
 888                 goto end;
 889         }
 890
 891         count = cst->package.elements[0].integer.value;
 892
 893         /* Validate number of power states. */
 894         if (count < 1 || count != cst->package.count - 1) {
 895                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 896                 status = -EFAULT;
 897                 goto end;
 898         }
 899
 900         /* Tell driver that at least _CST is supported. */
 901         pr->flags.has_cst = 1;
 902
 903         for (i = 1; i <= count; i++) {
 904                 union acpi_object *element;
 905                 union acpi_object *obj;
 906                 struct acpi_power_register *reg;
 907                 struct acpi_processor_cx cx;
 908
 909                 memset(&cx, 0, sizeof(cx));
 910
 911                 element = &(cst->package.elements[i]);
 912                 if (element->type != ACPI_TYPE_PACKAGE)
 913                         continue;
 914
 915                 if (element->package.count != 4)
 916                         continue;
 917
 918                 obj = &(element->package.elements[0]);
 919
 920                 if (obj->type != ACPI_TYPE_BUFFER)
 921                         continue;
 922
 923                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 924
 925                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 926                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 927                         continue;
 928
 929                 /* There should be an easy way to extract an integer... */
 930                 obj = &(element->package.elements[1]);
 931                 if (obj->type != ACPI_TYPE_INTEGER)
 932                         continue;
 933
 934                 cx.type = obj->integer.value;
 935                 /*
 936                  * Some buggy BIOSes won't list C1 in _CST -
 937                  * Let acpi_processor_get_power_info_default() handle them later
 938                  */
 939                 if (i == 1 && cx.type != ACPI_STATE_C1)
 940                         current_count++;
 941
 942                 cx.address = reg->address;
 943                 cx.index = current_count + 1;
 944
 945                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 946                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 947                         if (acpi_processor_ffh_cstate_probe
 948                                         (pr->id, &cx, reg) == 0) {
 949                                 cx.entry_method = ACPI_CSTATE_FFH;
 950                         } else if (cx.type == ACPI_STATE_C1) {
 951                                 /*
 952                                  * C1 is a special case where FIXED_HARDWARE
 953                                  * can be handled in non-MWAIT way as well.
 954                                  * In that case, save this _CST entry info.
 955                                  * Otherwise, ignore this info and continue.
 956                                  */
 957                                 cx.entry_method = ACPI_CSTATE_HALT;
 958                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 959                         } else {
 960                                 continue;
 961                         }
 962                         if (cx.type == ACPI_STATE_C1 &&
 963                                         (idle_halt || idle_nomwait)) {
 964                                 /*
 965                                  * In most cases the C1 space_id obtained from
 966                                  * _CST object is FIXED_HARDWARE access mode.
 967                                  * But when the option of idle=halt is added,
 968                                  * the entry_method type should be changed from
 969                                  * CSTATE_FFH to CSTATE_HALT.
 970                                  * When the option of idle=nomwait is added,
 971                                  * the C1 entry_method type should be
 972                                  * CSTATE_HALT.
 973                                  */
 974                                 cx.entry_method = ACPI_CSTATE_HALT;
 975                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 976                         }
 977                 } else {
 978                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 979                                  cx.address);
 980                 }
 981
 982                 if (cx.type == ACPI_STATE_C1) {
 983                         cx.valid = 1;
 984                 }
 985
 986                 obj = &(element->package.elements[2]);
 987                 if (obj->type != ACPI_TYPE_INTEGER)
 988                         continue;
 989
 990                 cx.latency = obj->integer.value;
 991
 992                 obj = &(element->package.elements[3]);
 993                 if (obj->type != ACPI_TYPE_INTEGER)
 994                         continue;
 995
 996                 cx.power = obj->integer.value;
 997
 998                 current_count++;
 999                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
1000
1001                 /*
1002                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
1003                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
1004                  */
1005                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
1006                         printk(KERN_WARNING
1007                                "Limiting number of power states to max (%d)\n",
1008                                ACPI_PROCESSOR_MAX_POWER);
1009                         printk(KERN_WARNING
1010                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1011                         break;
1012                 }
1013         }
1014
1015         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
1016                           current_count));
1017
1018         /* Validate number of power states discovered */
1019         if (current_count < 2)
1020                 status = -EFAULT;
1021
1022       end:
1023         kfree(buffer.pointer);
1024
1025         return status;
1026 }
1027
1028 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
1029 {
1030
1031         if (!cx->address)
1032                 return;
1033
1034         /*
1035          * C2 latency must be less than or equal to 100
1036          * microseconds.
1037          */
1038         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
1039                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1040                                   "latency too large [%d]\n", cx->latency));
1041                 return;
1042         }
1043
1044         /*
1045          * Otherwise we've met all of our C2 requirements.
1046          * Normalize the C2 latency to expidite policy
1047          */
1048         cx->valid = 1;
1049
1050 #ifndef CONFIG_CPU_IDLE
1051         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1052 #else
1053         cx->latency_ticks = cx->latency;
1054 #endif
1055
1056         return;
1057 }
1058
1059 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
1060                                            struct acpi_processor_cx *cx)
1061 {
1062         static int bm_check_flag;
1063
1064
1065         if (!cx->address)
1066                 return;
1067
1068         /*
1069          * C3 latency must be less than or equal to 1000
1070          * microseconds.
1071          */
1072         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
1073                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1074                                   "latency too large [%d]\n", cx->latency));
1075                 return;
1076         }
1077
1078         /*
1079          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
1080          * DMA transfers are used by any ISA device to avoid livelock.
1081          * Note that we could disable Type-F DMA (as recommended by
1082          * the erratum), but this is known to disrupt certain ISA
1083          * devices thus we take the conservative approach.
1084          */
1085         else if (errata.piix4.fdma) {
1086                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1087                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
1088                 return;
1089         }
1090
1091         /* All the logic here assumes flags.bm_check is same across all CPUs */
1092         if (!bm_check_flag) {
1093                 /* Determine whether bm_check is needed based on CPU  */
1094                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
1095                 bm_check_flag = pr->flags.bm_check;
1096         } else {
1097                 pr->flags.bm_check = bm_check_flag;
1098         }
1099
1100         if (pr->flags.bm_check) {
1101                 if (!pr->flags.bm_control) {
1102                         if (pr->flags.has_cst != 1) {
1103                                 /* bus mastering control is necessary */
1104                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1105                                         "C3 support requires BM control\n"));
1106                                 return;
1107                         } else {
1108                                 /* Here we enter C3 without bus mastering */
1109                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1110                                         "C3 support without BM control\n"));
1111                         }
1112                 }
1113         } else {
1114                 /*
1115                  * WBINVD should be set in fadt, for C3 state to be
1116                  * supported on when bm_check is not required.
1117                  */
1118                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
1119                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1120                                           "Cache invalidation should work properly"
1121                                           " for C3 to be enabled on SMP systems\n"));
1122                         return;
1123                 }
1124                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1125         }
1126
1127         /*
1128          * Otherwise we've met all of our C3 requirements.
1129          * Normalize the C3 latency to expidite policy.  Enable
1130          * checking of bus mastering status (bm_check) so we can
1131          * use this in our C3 policy
1132          */
1133         cx->valid = 1;
1134
1135 #ifndef CONFIG_CPU_IDLE
1136         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1137 #else
1138         cx->latency_ticks = cx->latency;
1139 #endif
1140
1141         return;
1142 }
1143
1144 static int acpi_processor_power_verify(struct acpi_processor *pr)
1145 {
1146         unsigned int i;
1147         unsigned int working = 0;
1148
1149         pr->power.timer_broadcast_on_state = INT_MAX;
1150
1151         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1152                 struct acpi_processor_cx *cx = &pr->power.states[i];
1153
1154                 switch (cx->type) {
1155                 case ACPI_STATE_C1:
1156                         cx->valid = 1;
1157                         break;
1158
1159                 case ACPI_STATE_C2:
1160                         acpi_processor_power_verify_c2(cx);
1161                         if (cx->valid)
1162                                 acpi_timer_check_state(i, pr, cx);
1163                         break;
1164
1165                 case ACPI_STATE_C3:
1166                         acpi_processor_power_verify_c3(pr, cx);
1167                         if (cx->valid)
1168                                 acpi_timer_check_state(i, pr, cx);
1169                         break;
1170                 }
1171
1172                 if (cx->valid)
1173                         working++;
1174         }
1175
1176         acpi_propagate_timer_broadcast(pr);
1177
1178         return (working);
1179 }
1180
1181 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1182 {
1183         unsigned int i;
1184         int result;
1185
1186
1187         /* NOTE: the idle thread may not be running while calling
1188          * this function */
1189
1190         /* Zero initialize all the C-states info. */
1191         memset(pr->power.states, 0, sizeof(pr->power.states));
1192
1193         result = acpi_processor_get_power_info_cst(pr);
1194         if (result == -ENODEV)
1195                 result = acpi_processor_get_power_info_fadt(pr);
1196
1197         if (result)
1198                 return result;
1199
1200         acpi_processor_get_power_info_default(pr);
1201
1202         pr->power.count = acpi_processor_power_verify(pr);
1203
1204 #ifndef CONFIG_CPU_IDLE
1205         /*
1206          * Set Default Policy
1207          * ------------------
1208          * Now that we know which states are supported, set the default
1209          * policy.  Note that this policy can be changed dynamically
1210          * (e.g. encourage deeper sleeps to conserve battery life when
1211          * not on AC).
1212          */
1213         result = acpi_processor_set_power_policy(pr);
1214         if (result)
1215                 return result;
1216 #endif
1217
1218         /*
1219          * if one state of type C2 or C3 is available, mark this
1220          * CPU as being "idle manageable"
1221          */
1222         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1223                 if (pr->power.states[i].valid) {
1224                         pr->power.count = i;
1225                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1226                                 pr->flags.power = 1;
1227                 }
1228         }
1229
1230         return 0;
1231 }
1232
1233 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1234 {
1235         struct acpi_processor *pr = seq->private;
1236         unsigned int i;
1237
1238
1239         if (!pr)
1240                 goto end;
1241
1242         seq_printf(seq, "active state:            C%zd\n"
1243                    "max_cstate:              C%d\n"
1244                    "bus master activity:     %08x\n"
1245                    "maximum allowed latency: %d usec\n",
1246                    pr->power.state ? pr->power.state - pr->power.states : 0,
1247                    max_cstate, (unsigned)pr->power.bm_activity,
1248                    pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
1249
1250         seq_puts(seq, "states:\n");
1251
1252         for (i = 1; i <= pr->power.count; i++) {
1253                 seq_printf(seq, "   %cC%d:                  ",
1254                            (&pr->power.states[i] ==
1255                             pr->power.state ? '*' : ' '), i);
1256
1257                 if (!pr->power.states[i].valid) {
1258                         seq_puts(seq, "<not supported>\n");
1259                         continue;
1260                 }
1261
1262                 switch (pr->power.states[i].type) {
1263                 case ACPI_STATE_C1:
1264                         seq_printf(seq, "type[C1] ");
1265                         break;
1266                 case ACPI_STATE_C2:
1267                         seq_printf(seq, "type[C2] ");
1268                         break;
1269                 case ACPI_STATE_C3:
1270                         seq_printf(seq, "type[C3] ");
1271                         break;
1272                 default:
1273                         seq_printf(seq, "type[--] ");
1274                         break;
1275                 }
1276
1277                 if (pr->power.states[i].promotion.state)
1278                         seq_printf(seq, "promotion[C%zd] ",
1279                                    (pr->power.states[i].promotion.state -
1280                                     pr->power.states));
1281                 else
1282                         seq_puts(seq, "promotion[--] ");
1283
1284                 if (pr->power.states[i].demotion.state)
1285                         seq_printf(seq, "demotion[C%zd] ",
1286                                    (pr->power.states[i].demotion.state -
1287                                     pr->power.states));
1288                 else
1289                         seq_puts(seq, "demotion[--] ");
1290
1291                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1292                            pr->power.states[i].latency,
1293                            pr->power.states[i].usage,
1294                            (unsigned long long)pr->power.states[i].time);
1295         }
1296
1297       end:
1298         return 0;
1299 }
1300
1301 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1302 {
1303         return single_open(file, acpi_processor_power_seq_show,
1304                            PDE(inode)->data);
1305 }
1306
1307 static const struct file_operations acpi_processor_power_fops = {
1308         .owner = THIS_MODULE,
1309         .open = acpi_processor_power_open_fs,
1310         .read = seq_read,
1311         .llseek = seq_lseek,
1312         .release = single_release,
1313 };
1314
1315 #ifndef CONFIG_CPU_IDLE
1316
1317 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1318 {
1319         int result = 0;
1320
1321         if (boot_option_idle_override)
1322                 return 0;
1323
1324         if (!pr)
1325                 return -EINVAL;
1326
1327         if (nocst) {
1328                 return -ENODEV;
1329         }
1330
1331         if (!pr->flags.power_setup_done)
1332                 return -ENODEV;
1333
1334         /*
1335          * Fall back to the default idle loop, when pm_idle_save had
1336          * been initialized.
1337          */
1338         if (pm_idle_save) {
1339                 pm_idle = pm_idle_save;
1340                 /* Relies on interrupts forcing exit from idle. */
1341                 synchronize_sched();
1342         }
1343
1344         pr->flags.power = 0;
1345         result = acpi_processor_get_power_info(pr);
1346         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1347                 pm_idle = acpi_processor_idle;
1348
1349         return result;
1350 }
1351
1352 #ifdef CONFIG_SMP
1353 static void smp_callback(void *v)
1354 {
1355         /* we already woke the CPU up, nothing more to do */
1356 }
1357
1358 /*
1359  * This function gets called when a part of the kernel has a new latency
1360  * requirement.  This means we need to get all processors out of their C-state,
1361  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1362  * wakes them all right up.
1363  */
1364 static int acpi_processor_latency_notify(struct notifier_block *b,
1365                 unsigned long l, void *v)
1366 {
1367         smp_call_function(smp_callback, NULL, 1);
1368         return NOTIFY_OK;
1369 }
1370
1371 static struct notifier_block acpi_processor_latency_notifier = {
1372         .notifier_call = acpi_processor_latency_notify,
1373 };
1374
1375 #endif
1376
1377 #else /* CONFIG_CPU_IDLE */
1378
1379 /**
1380  * acpi_idle_bm_check - checks if bus master activity was detected
1381  */
1382 static int acpi_idle_bm_check(void)
1383 {
1384         u32 bm_status = 0;
1385
1386         acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
1387         if (bm_status)
1388                 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1389         /*
1390          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
1391          * the true state of bus mastering activity; forcing us to
1392          * manually check the BMIDEA bit of each IDE channel.
1393          */
1394         else if (errata.piix4.bmisx) {
1395                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
1396                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
1397                         bm_status = 1;
1398         }
1399         return bm_status;
1400 }
1401
1402 /**
1403  * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
1404  * @pr: the processor
1405  * @target: the new target state
1406  */
1407 static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
1408                                            struct acpi_processor_cx *target)
1409 {
1410         if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
1411                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1412                 pr->flags.bm_rld_set = 0;
1413         }
1414
1415         if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
1416                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
1417                 pr->flags.bm_rld_set = 1;
1418         }
1419 }
1420
1421 /**
1422  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
1423  * @cx: cstate data
1424  *
1425  * Caller disables interrupt before call and enables interrupt after return.
1426  */
1427 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
1428 {
1429         /* Don't trace irqs off for idle */
1430         stop_critical_timings();
1431         if (cx->entry_method == ACPI_CSTATE_FFH) {
1432                 /* Call into architectural FFH based C-state */
1433                 acpi_processor_ffh_cstate_enter(cx);
1434         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
1435                 acpi_safe_halt();
1436         } else {
1437                 int unused;
1438                 /* IO port based C-state */
1439                 inb(cx->address);
1440                 /* Dummy wait op - must do something useless after P_LVL2 read
1441                    because chipsets cannot guarantee that STPCLK# signal
1442                    gets asserted in time to freeze execution properly. */
1443                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
1444         }
1445         start_critical_timings();
1446 }
1447
1448 /**
1449  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
1450  * @dev: the target CPU
1451  * @state: the state data
1452  *
1453  * This is equivalent to the HALT instruction.
1454  */
1455 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
1456                               struct cpuidle_state *state)
1457 {
1458         u32 t1, t2;
1459         struct acpi_processor *pr;
1460         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1461
1462         pr = __get_cpu_var(processors);
1463
1464         if (unlikely(!pr))
1465                 return 0;
1466
1467         local_irq_disable();
1468
1469         /* Do not access any ACPI IO ports in suspend path */
1470         if (acpi_idle_suspend) {
1471                 acpi_safe_halt();
1472                 local_irq_enable();
1473                 return 0;
1474         }
1475
1476         if (pr->flags.bm_check)
1477                 acpi_idle_update_bm_rld(pr, cx);
1478
1479         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1480         acpi_idle_do_entry(cx);
1481         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1482
1483         local_irq_enable();
1484         cx->usage++;
1485
1486         return ticks_elapsed_in_us(t1, t2);
1487 }
1488
1489 /**
1490  * acpi_idle_enter_simple - enters an ACPI state without BM handling
1491  * @dev: the target CPU
1492  * @state: the state data
1493  */
1494 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
1495                                   struct cpuidle_state *state)
1496 {
1497         struct acpi_processor *pr;
1498         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1499         u32 t1, t2;
1500         int sleep_ticks = 0;
1501
1502         pr = __get_cpu_var(processors);
1503
1504         if (unlikely(!pr))
1505                 return 0;
1506
1507         if (acpi_idle_suspend)
1508                 return(acpi_idle_enter_c1(dev, state));
1509
1510         local_irq_disable();
1511         current_thread_info()->status &= ~TS_POLLING;
1512         /*
1513          * TS_POLLING-cleared state must be visible before we test
1514          * NEED_RESCHED:
1515          */
1516         smp_mb();
1517
1518         if (unlikely(need_resched())) {
1519                 current_thread_info()->status |= TS_POLLING;
1520                 local_irq_enable();
1521                 return 0;
1522         }
1523
1524         /*
1525          * Must be done before busmaster disable as we might need to
1526          * access HPET !
1527          */
1528         acpi_state_timer_broadcast(pr, cx, 1);
1529
1530         if (pr->flags.bm_check)
1531                 acpi_idle_update_bm_rld(pr, cx);
1532
1533         if (cx->type == ACPI_STATE_C3)
1534                 ACPI_FLUSH_CPU_CACHE();
1535
1536         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1537         /* Tell the scheduler that we are going deep-idle: */
1538         sched_clock_idle_sleep_event();
1539         acpi_idle_do_entry(cx);
1540         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1541
1542 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
1543         /* TSC could halt in idle, so notify users */
1544         if (tsc_halts_in_c(cx->type))
1545                 mark_tsc_unstable("TSC halts in idle");;
1546 #endif
1547         sleep_ticks = ticks_elapsed(t1, t2);
1548
1549         /* Tell the scheduler how much we idled: */
1550         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1551
1552         local_irq_enable();
1553         current_thread_info()->status |= TS_POLLING;
1554
1555         cx->usage++;
1556
1557         acpi_state_timer_broadcast(pr, cx, 0);
1558         cx->time += sleep_ticks;
1559         return ticks_elapsed_in_us(t1, t2);
1560 }
1561
1562 static int c3_cpu_count;
1563 static DEFINE_SPINLOCK(c3_lock);
1564
1565 /**
1566  * acpi_idle_enter_bm - enters C3 with proper BM handling
1567  * @dev: the target CPU
1568  * @state: the state data
1569  *
1570  * If BM is detected, the deepest non-C3 idle state is entered instead.
1571  */
1572 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
1573                               struct cpuidle_state *state)
1574 {
1575         struct acpi_processor *pr;
1576         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1577         u32 t1, t2;
1578         int sleep_ticks = 0;
1579
1580         pr = __get_cpu_var(processors);
1581
1582         if (unlikely(!pr))
1583                 return 0;
1584
1585         if (acpi_idle_suspend)
1586                 return(acpi_idle_enter_c1(dev, state));
1587
1588         if (acpi_idle_bm_check()) {
1589                 if (dev->safe_state) {
1590                         dev->last_state = dev->safe_state;
1591                         return dev->safe_state->enter(dev, dev->safe_state);
1592                 } else {
1593                         local_irq_disable();
1594                         acpi_safe_halt();
1595                         local_irq_enable();
1596                         return 0;
1597                 }
1598         }
1599
1600         local_irq_disable();
1601         current_thread_info()->status &= ~TS_POLLING;
1602         /*
1603          * TS_POLLING-cleared state must be visible before we test
1604          * NEED_RESCHED:
1605          */
1606         smp_mb();
1607
1608         if (unlikely(need_resched())) {
1609                 current_thread_info()->status |= TS_POLLING;
1610                 local_irq_enable();
1611                 return 0;
1612         }
1613
1614         acpi_unlazy_tlb(smp_processor_id());
1615
1616         /* Tell the scheduler that we are going deep-idle: */
1617         sched_clock_idle_sleep_event();
1618         /*
1619          * Must be done before busmaster disable as we might need to
1620          * access HPET !
1621          */
1622         acpi_state_timer_broadcast(pr, cx, 1);
1623
1624         acpi_idle_update_bm_rld(pr, cx);
1625
1626         /*
1627          * disable bus master
1628          * bm_check implies we need ARB_DIS
1629          * !bm_check implies we need cache flush
1630          * bm_control implies whether we can do ARB_DIS
1631          *
1632          * That leaves a case where bm_check is set and bm_control is
1633          * not set. In that case we cannot do much, we enter C3
1634          * without doing anything.
1635          */
1636         if (pr->flags.bm_check && pr->flags.bm_control) {
1637                 spin_lock(&c3_lock);
1638                 c3_cpu_count++;
1639                 /* Disable bus master arbitration when all CPUs are in C3 */
1640                 if (c3_cpu_count == num_online_cpus())
1641                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
1642                 spin_unlock(&c3_lock);
1643         } else if (!pr->flags.bm_check) {
1644                 ACPI_FLUSH_CPU_CACHE();
1645         }
1646
1647         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1648         acpi_idle_do_entry(cx);
1649         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1650
1651         /* Re-enable bus master arbitration */
1652         if (pr->flags.bm_check && pr->flags.bm_control) {
1653                 spin_lock(&c3_lock);
1654                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
1655                 c3_cpu_count--;
1656                 spin_unlock(&c3_lock);
1657         }
1658
1659 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
1660         /* TSC could halt in idle, so notify users */
1661         if (tsc_halts_in_c(ACPI_STATE_C3))
1662                 mark_tsc_unstable("TSC halts in idle");
1663 #endif
1664         sleep_ticks = ticks_elapsed(t1, t2);
1665         /* Tell the scheduler how much we idled: */
1666         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1667
1668         local_irq_enable();
1669         current_thread_info()->status |= TS_POLLING;
1670
1671         cx->usage++;
1672
1673         acpi_state_timer_broadcast(pr, cx, 0);
1674         cx->time += sleep_ticks;
1675         return ticks_elapsed_in_us(t1, t2);
1676 }
1677
1678 struct cpuidle_driver acpi_idle_driver = {
1679         .name =         "acpi_idle",
1680         .owner =        THIS_MODULE,
1681 };
1682
1683 /**
1684  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1685  * @pr: the ACPI processor
1686  */
1687 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1688 {
1689         int i, count = CPUIDLE_DRIVER_STATE_START;
1690         struct acpi_processor_cx *cx;
1691         struct cpuidle_state *state;
1692         struct cpuidle_device *dev = &pr->power.dev;
1693
1694         if (!pr->flags.power_setup_done)
1695                 return -EINVAL;
1696
1697         if (pr->flags.power == 0) {
1698                 return -EINVAL;
1699         }
1700
1701         dev->cpu = pr->id;
1702         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1703                 dev->states[i].name[0] = '\0';
1704                 dev->states[i].desc[0] = '\0';
1705         }
1706
1707         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1708                 cx = &pr->power.states[i];
1709                 state = &dev->states[count];
1710
1711                 if (!cx->valid)
1712                         continue;
1713
1714 #ifdef CONFIG_HOTPLUG_CPU
1715                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1716                     !pr->flags.has_cst &&
1717                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1718                         continue;
1719 #endif
1720                 cpuidle_set_statedata(state, cx);
1721
1722                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1723                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1724                 state->exit_latency = cx->latency;
1725                 state->target_residency = cx->latency * latency_factor;
1726                 state->power_usage = cx->power;
1727
1728                 state->flags = 0;
1729                 switch (cx->type) {
1730                         case ACPI_STATE_C1:
1731                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1732                         if (cx->entry_method == ACPI_CSTATE_FFH)
1733                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1734
1735                         state->enter = acpi_idle_enter_c1;
1736                         dev->safe_state = state;
1737                         break;
1738
1739                         case ACPI_STATE_C2:
1740                         state->flags |= CPUIDLE_FLAG_BALANCED;
1741                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1742                         state->enter = acpi_idle_enter_simple;
1743                         dev->safe_state = state;
1744                         break;
1745
1746                         case ACPI_STATE_C3:
1747                         state->flags |= CPUIDLE_FLAG_DEEP;
1748                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1749                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1750                         state->enter = pr->flags.bm_check ?
1751                                         acpi_idle_enter_bm :
1752                                         acpi_idle_enter_simple;
1753                         break;
1754                 }
1755
1756                 count++;
1757                 if (count == CPUIDLE_STATE_MAX)
1758                         break;
1759         }
1760
1761         dev->state_count = count;
1762
1763         if (!count)
1764                 return -EINVAL;
1765
1766         return 0;
1767 }
1768
1769 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1770 {
1771         int ret = 0;
1772
1773         if (boot_option_idle_override)
1774                 return 0;
1775
1776         if (!pr)
1777                 return -EINVAL;
1778
1779         if (nocst) {
1780                 return -ENODEV;
1781         }
1782
1783         if (!pr->flags.power_setup_done)
1784                 return -ENODEV;
1785
1786         cpuidle_pause_and_lock();
1787         cpuidle_disable_device(&pr->power.dev);
1788         acpi_processor_get_power_info(pr);
1789         if (pr->flags.power) {
1790                 acpi_processor_setup_cpuidle(pr);
1791                 ret = cpuidle_enable_device(&pr->power.dev);
1792         }
1793         cpuidle_resume_and_unlock();
1794
1795         return ret;
1796 }
1797
1798 #endif /* CONFIG_CPU_IDLE */
1799
1800 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1801                               struct acpi_device *device)
1802 {
1803         acpi_status status = 0;
1804         static int first_run;
1805         struct proc_dir_entry *entry = NULL;
1806         unsigned int i;
1807
1808         if (boot_option_idle_override)
1809                 return 0;
1810
1811         if (!first_run) {
1812                 if (idle_halt) {
1813                         /*
1814                          * When the boot option of "idle=halt" is added, halt
1815                          * is used for CPU IDLE.
1816                          * In such case C2/C3 is meaningless. So the max_cstate
1817                          * is set to one.
1818                          */
1819                         max_cstate = 1;
1820                 }
1821                 dmi_check_system(processor_power_dmi_table);
1822                 max_cstate = acpi_processor_cstate_check(max_cstate);
1823                 if (max_cstate < ACPI_C_STATES_MAX)
1824                         printk(KERN_NOTICE
1825                                "ACPI: processor limited to max C-state %d\n",
1826                                max_cstate);
1827                 first_run++;
1828 #if !defined(CONFIG_CPU_IDLE) && defined(CONFIG_SMP)
1829                 pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY,
1830                                 &acpi_processor_latency_notifier);
1831 #endif
1832         }
1833
1834         if (!pr)
1835                 return -EINVAL;
1836
1837         if (acpi_gbl_FADT.cst_control && !nocst) {
1838                 status =
1839                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1840                 if (ACPI_FAILURE(status)) {
1841                         ACPI_EXCEPTION((AE_INFO, status,
1842                                         "Notifying BIOS of _CST ability failed"));
1843                 }
1844         }
1845
1846         acpi_processor_get_power_info(pr);
1847         pr->flags.power_setup_done = 1;
1848
1849         /*
1850          * Install the idle handler if processor power management is supported.
1851          * Note that we use previously set idle handler will be used on
1852          * platforms that only support C1.
1853          */
1854         if (pr->flags.power) {
1855 #ifdef CONFIG_CPU_IDLE
1856                 acpi_processor_setup_cpuidle(pr);
1857                 if (cpuidle_register_device(&pr->power.dev))
1858                         return -EIO;
1859 #endif
1860
1861                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1862                 for (i = 1; i <= pr->power.count; i++)
1863                         if (pr->power.states[i].valid)
1864                                 printk(" C%d[C%d]", i,
1865                                        pr->power.states[i].type);
1866                 printk(")\n");
1867
1868 #ifndef CONFIG_CPU_IDLE
1869                 if (pr->id == 0) {
1870                         pm_idle_save = pm_idle;
1871                         pm_idle = acpi_processor_idle;
1872                 }
1873 #endif
1874         }
1875
1876         /* 'power' [R] */
1877         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1878                                  S_IRUGO, acpi_device_dir(device),
1879                                  &acpi_processor_power_fops,
1880                                  acpi_driver_data(device));
1881         if (!entry)
1882                 return -EIO;
1883         return 0;
1884 }
1885
1886 int acpi_processor_power_exit(struct acpi_processor *pr,
1887                               struct acpi_device *device)
1888 {
1889         if (boot_option_idle_override)
1890                 return 0;
1891
1892 #ifdef CONFIG_CPU_IDLE
1893         cpuidle_unregister_device(&pr->power.dev);
1894 #endif
1895         pr->flags.power_setup_done = 0;
1896
1897         if (acpi_device_dir(device))
1898                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1899                                   acpi_device_dir(device));
1900
1901 #ifndef CONFIG_CPU_IDLE
1902
1903         /* Unregister the idle handler when processor #0 is removed. */
1904         if (pr->id == 0) {
1905                 if (pm_idle_save)
1906                         pm_idle = pm_idle_save;
1907
1908                 /*
1909                  * We are about to unload the current idle thread pm callback
1910                  * (pm_idle), Wait for all processors to update cached/local
1911                  * copies of pm_idle before proceeding.
1912                  */
1913                 cpu_idle_wait();
1914 #ifdef CONFIG_SMP
1915                 pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY,
1916                                 &acpi_processor_latency_notifier);
1917 #endif
1918         }
1919 #endif
1920
1921         return 0;
1922 }