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
  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
  61 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  62 #define ACPI_PROCESSOR_CLASS            "processor"
  63 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  64 ACPI_MODULE_NAME("processor_idle");
  65 #define ACPI_PROCESSOR_FILE_POWER       "power"
  66 #define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
  67 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  68 #ifndef CONFIG_CPU_IDLE
  69 #define C2_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
  70 #define C3_OVERHEAD                     4       /* 1us (3.579 ticks per us) */
  71 static void (*pm_idle_save) (void) __read_mostly;
  72 #else
  73 #define C2_OVERHEAD                     1       /* 1us */
  74 #define C3_OVERHEAD                     1       /* 1us */
  75 #endif
  76 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  77
  78 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  79 #ifdef CONFIG_CPU_IDLE
  80 module_param(max_cstate, uint, 0000);
  81 #else
  82 module_param(max_cstate, uint, 0644);
  83 #endif
  84 static unsigned int nocst __read_mostly;
  85 module_param(nocst, uint, 0000);
  86
  87 #ifndef CONFIG_CPU_IDLE
  88 /*
  89  * bm_history -- bit-mask with a bit per jiffy of bus-master activity
  90  * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
  91  * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
  92  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
  93  * reduce history for more aggressive entry into C3
  94  */
  95 static unsigned int bm_history __read_mostly =
  96     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
  97 module_param(bm_history, uint, 0644);
  98
  99 static int acpi_processor_set_power_policy(struct acpi_processor *pr);
 100
 101 #else   /* CONFIG_CPU_IDLE */
 102 static unsigned int latency_factor __read_mostly = 2;
 103 module_param(latency_factor, uint, 0644);
 104 #endif
 105
 106 /*
 107  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
 108  * For now disable this. Probably a bug somewhere else.
 109  *
 110  * To skip this limit, boot/load with a large max_cstate limit.
 111  */
 112 static int set_max_cstate(const struct dmi_system_id *id)
 113 {
 114         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
 115                 return 0;
 116
 117         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
 118                " Override with \"processor.max_cstate=%d\"\n", id->ident,
 119                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 120
 121         max_cstate = (long)id->driver_data;
 122
 123         return 0;
 124 }
 125
 126 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 127    callers to only run once -AK */
 128 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 129         { set_max_cstate, "IBM ThinkPad R40e", {
 130           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 131           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
 132         { set_max_cstate, "IBM ThinkPad R40e", {
 133           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 134           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
 135         { set_max_cstate, "IBM ThinkPad R40e", {
 136           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 137           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
 138         { set_max_cstate, "IBM ThinkPad R40e", {
 139           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 140           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
 141         { set_max_cstate, "IBM ThinkPad R40e", {
 142           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 143           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
 144         { set_max_cstate, "IBM ThinkPad R40e", {
 145           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 146           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
 147         { set_max_cstate, "IBM ThinkPad R40e", {
 148           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 149           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
 150         { set_max_cstate, "IBM ThinkPad R40e", {
 151           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 152           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
 153         { set_max_cstate, "IBM ThinkPad R40e", {
 154           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 155           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
 156         { set_max_cstate, "IBM ThinkPad R40e", {
 157           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 158           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
 159         { set_max_cstate, "IBM ThinkPad R40e", {
 160           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 161           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
 162         { set_max_cstate, "IBM ThinkPad R40e", {
 163           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 164           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
 165         { set_max_cstate, "IBM ThinkPad R40e", {
 166           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 167           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
 168         { set_max_cstate, "IBM ThinkPad R40e", {
 169           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 170           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
 171         { set_max_cstate, "IBM ThinkPad R40e", {
 172           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 173           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
 174         { set_max_cstate, "IBM ThinkPad R40e", {
 175           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 176           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
 177         { set_max_cstate, "Medion 41700", {
 178           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 179           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
 180         { set_max_cstate, "Clevo 5600D", {
 181           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 182           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 183          (void *)2},
 184         {},
 185 };
 186
 187 static inline u32 ticks_elapsed(u32 t1, u32 t2)
 188 {
 189         if (t2 >= t1)
 190                 return (t2 - t1);
 191         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 192                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 193         else
 194                 return ((0xFFFFFFFF - t1) + t2);
 195 }
 196
 197 static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
 198 {
 199         if (t2 >= t1)
 200                 return PM_TIMER_TICKS_TO_US(t2 - t1);
 201         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 202                 return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 203         else
 204                 return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
 205 }
 206
 207 /*
 208  * Callers should disable interrupts before the call and enable
 209  * interrupts after return.
 210  */
 211 static void acpi_safe_halt(void)
 212 {
 213         current_thread_info()->status &= ~TS_POLLING;
 214         /*
 215          * TS_POLLING-cleared state must be visible before we
 216          * test NEED_RESCHED:
 217          */
 218         smp_mb();
 219         if (!need_resched())
 220                 safe_halt();
 221         current_thread_info()->status |= TS_POLLING;
 222 }
 223
 224 #ifndef CONFIG_CPU_IDLE
 225
 226 static void
 227 acpi_processor_power_activate(struct acpi_processor *pr,
 228                               struct acpi_processor_cx *new)
 229 {
 230         struct acpi_processor_cx *old;
 231
 232         if (!pr || !new)
 233                 return;
 234
 235         old = pr->power.state;
 236
 237         if (old)
 238                 old->promotion.count = 0;
 239         new->demotion.count = 0;
 240
 241         /* Cleanup from old state. */
 242         if (old) {
 243                 switch (old->type) {
 244                 case ACPI_STATE_C3:
 245                         /* Disable bus master reload */
 246                         if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
 247                                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
 248                         break;
 249                 }
 250         }
 251
 252         /* Prepare to use new state. */
 253         switch (new->type) {
 254         case ACPI_STATE_C3:
 255                 /* Enable bus master reload */
 256                 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
 257                         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 258                 break;
 259         }
 260
 261         pr->power.state = new;
 262
 263         return;
 264 }
 265
 266 static atomic_t c3_cpu_count;
 267
 268 /* Common C-state entry for C2, C3, .. */
 269 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
 270 {
 271         if (cstate->entry_method == ACPI_CSTATE_FFH) {
 272                 /* Call into architectural FFH based C-state */
 273                 acpi_processor_ffh_cstate_enter(cstate);
 274         } else {
 275                 int unused;
 276                 /* IO port based C-state */
 277                 inb(cstate->address);
 278                 /* Dummy wait op - must do something useless after P_LVL2 read
 279                    because chipsets cannot guarantee that STPCLK# signal
 280                    gets asserted in time to freeze execution properly. */
 281                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 282         }
 283 }
 284 #endif /* !CONFIG_CPU_IDLE */
 285
 286 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 287
 288 /*
 289  * Some BIOS implementations switch to C3 in the published C2 state.
 290  * This seems to be a common problem on AMD boxen, but other vendors
 291  * are affected too. We pick the most conservative approach: we assume
 292  * that the local APIC stops in both C2 and C3.
 293  */
 294 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 295                                    struct acpi_processor_cx *cx)
 296 {
 297         struct acpi_processor_power *pwr = &pr->power;
 298         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 299
 300         /*
 301          * Check, if one of the previous states already marked the lapic
 302          * unstable
 303          */
 304         if (pwr->timer_broadcast_on_state < state)
 305                 return;
 306
 307         if (cx->type >= type)
 308                 pr->power.timer_broadcast_on_state = state;
 309 }
 310
 311 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
 312 {
 313         unsigned long reason;
 314
 315         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 316                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 317
 318         clockevents_notify(reason, &pr->id);
 319 }
 320
 321 /* Power(C) State timer broadcast control */
 322 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 323                                        struct acpi_processor_cx *cx,
 324                                        int broadcast)
 325 {
 326         int state = cx - pr->power.states;
 327
 328         if (state >= pr->power.timer_broadcast_on_state) {
 329                 unsigned long reason;
 330
 331                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 332                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 333                 clockevents_notify(reason, &pr->id);
 334         }
 335 }
 336
 337 #else
 338
 339 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 340                                    struct acpi_processor_cx *cstate) { }
 341 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
 342 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 343                                        struct acpi_processor_cx *cx,
 344                                        int broadcast)
 345 {
 346 }
 347
 348 #endif
 349
 350 /*
 351  * Suspend / resume control
 352  */
 353 static int acpi_idle_suspend;
 354
 355 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 356 {
 357         acpi_idle_suspend = 1;
 358         return 0;
 359 }
 360
 361 int acpi_processor_resume(struct acpi_device * device)
 362 {
 363         acpi_idle_suspend = 0;
 364         return 0;
 365 }
 366
 367 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
 368 static int tsc_halts_in_c(int state)
 369 {
 370         switch (boot_cpu_data.x86_vendor) {
 371         case X86_VENDOR_AMD:
 372                 /*
 373                  * AMD Fam10h TSC will tick in all
 374                  * C/P/S0/S1 states when this bit is set.
 375                  */
 376                 if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
 377                         return 0;
 378                 /*FALL THROUGH*/
 379         case X86_VENDOR_INTEL:
 380                 /* Several cases known where TSC halts in C2 too */
 381         default:
 382                 return state > ACPI_STATE_C1;
 383         }
 384 }
 385 #endif
 386
 387 #ifndef CONFIG_CPU_IDLE
 388 static void acpi_processor_idle(void)
 389 {
 390         struct acpi_processor *pr = NULL;
 391         struct acpi_processor_cx *cx = NULL;
 392         struct acpi_processor_cx *next_state = NULL;
 393         int sleep_ticks = 0;
 394         u32 t1, t2 = 0;
 395
 396         /*
 397          * Interrupts must be disabled during bus mastering calculations and
 398          * for C2/C3 transitions.
 399          */
 400         local_irq_disable();
 401
 402         pr = processors[smp_processor_id()];
 403         if (!pr) {
 404                 local_irq_enable();
 405                 return;
 406         }
 407
 408         /*
 409          * Check whether we truly need to go idle, or should
 410          * reschedule:
 411          */
 412         if (unlikely(need_resched())) {
 413                 local_irq_enable();
 414                 return;
 415         }
 416
 417         cx = pr->power.state;
 418         if (!cx || acpi_idle_suspend) {
 419                 if (pm_idle_save)
 420                         pm_idle_save();
 421                 else
 422                         acpi_safe_halt();
 423
 424                 local_irq_enable();
 425                 return;
 426         }
 427
 428         /*
 429          * Check BM Activity
 430          * -----------------
 431          * Check for bus mastering activity (if required), record, and check
 432          * for demotion.
 433          */
 434         if (pr->flags.bm_check) {
 435                 u32 bm_status = 0;
 436                 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
 437
 438                 if (diff > 31)
 439                         diff = 31;
 440
 441                 pr->power.bm_activity <<= diff;
 442
 443                 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 444                 if (bm_status) {
 445                         pr->power.bm_activity |= 0x1;
 446                         acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 447                 }
 448                 /*
 449                  * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 450                  * the true state of bus mastering activity; forcing us to
 451                  * manually check the BMIDEA bit of each IDE channel.
 452                  */
 453                 else if (errata.piix4.bmisx) {
 454                         if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 455                             || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 456                                 pr->power.bm_activity |= 0x1;
 457                 }
 458
 459                 pr->power.bm_check_timestamp = jiffies;
 460
 461                 /*
 462                  * If bus mastering is or was active this jiffy, demote
 463                  * to avoid a faulty transition.  Note that the processor
 464                  * won't enter a low-power state during this call (to this
 465                  * function) but should upon the next.
 466                  *
 467                  * TBD: A better policy might be to fallback to the demotion
 468                  *      state (use it for this quantum only) istead of
 469                  *      demoting -- and rely on duration as our sole demotion
 470                  *      qualification.  This may, however, introduce DMA
 471                  *      issues (e.g. floppy DMA transfer overrun/underrun).
 472                  */
 473                 if ((pr->power.bm_activity & 0x1) &&
 474                     cx->demotion.threshold.bm) {
 475                         local_irq_enable();
 476                         next_state = cx->demotion.state;
 477                         goto end;
 478                 }
 479         }
 480
 481 #ifdef CONFIG_HOTPLUG_CPU
 482         /*
 483          * Check for P_LVL2_UP flag before entering C2 and above on
 484          * an SMP system. We do it here instead of doing it at _CST/P_LVL
 485          * detection phase, to work cleanly with logical CPU hotplug.
 486          */
 487         if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 488             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 489                 cx = &pr->power.states[ACPI_STATE_C1];
 490 #endif
 491
 492         /*
 493          * Sleep:
 494          * ------
 495          * Invoke the current Cx state to put the processor to sleep.
 496          */
 497         if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
 498                 current_thread_info()->status &= ~TS_POLLING;
 499                 /*
 500                  * TS_POLLING-cleared state must be visible before we
 501                  * test NEED_RESCHED:
 502                  */
 503                 smp_mb();
 504                 if (need_resched()) {
 505                         current_thread_info()->status |= TS_POLLING;
 506                         local_irq_enable();
 507                         return;
 508                 }
 509         }
 510
 511         switch (cx->type) {
 512
 513         case ACPI_STATE_C1:
 514                 /*
 515                  * Invoke C1.
 516                  * Use the appropriate idle routine, the one that would
 517                  * be used without acpi C-states.
 518                  */
 519                 if (pm_idle_save)
 520                         pm_idle_save();
 521                 else
 522                         acpi_safe_halt();
 523
 524                 /*
 525                  * TBD: Can't get time duration while in C1, as resumes
 526                  *      go to an ISR rather than here.  Need to instrument
 527                  *      base interrupt handler.
 528                  *
 529                  * Note: the TSC better not stop in C1, sched_clock() will
 530                  *       skew otherwise.
 531                  */
 532                 sleep_ticks = 0xFFFFFFFF;
 533                 local_irq_enable();
 534                 break;
 535
 536         case ACPI_STATE_C2:
 537                 /* Get start time (ticks) */
 538                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 539                 /* Tell the scheduler that we are going deep-idle: */
 540                 sched_clock_idle_sleep_event();
 541                 /* Invoke C2 */
 542                 acpi_state_timer_broadcast(pr, cx, 1);
 543                 acpi_cstate_enter(cx);
 544                 /* Get end time (ticks) */
 545                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 546
 547 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
 548                 /* TSC halts in C2, so notify users */
 549                 if (tsc_halts_in_c(ACPI_STATE_C2))
 550                         mark_tsc_unstable("possible TSC halt in C2");
 551 #endif
 552                 /* Compute time (ticks) that we were actually asleep */
 553                 sleep_ticks = ticks_elapsed(t1, t2);
 554
 555                 /* Tell the scheduler how much we idled: */
 556                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 557
 558                 /* Re-enable interrupts */
 559                 local_irq_enable();
 560                 /* Do not account our idle-switching overhead: */
 561                 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
 562
 563                 current_thread_info()->status |= TS_POLLING;
 564                 acpi_state_timer_broadcast(pr, cx, 0);
 565                 break;
 566
 567         case ACPI_STATE_C3:
 568                 acpi_unlazy_tlb(smp_processor_id());
 569                 /*
 570                  * Must be done before busmaster disable as we might
 571                  * need to access HPET !
 572                  */
 573                 acpi_state_timer_broadcast(pr, cx, 1);
 574                 /*
 575                  * disable bus master
 576                  * bm_check implies we need ARB_DIS
 577                  * !bm_check implies we need cache flush
 578                  * bm_control implies whether we can do ARB_DIS
 579                  *
 580                  * That leaves a case where bm_check is set and bm_control is
 581                  * not set. In that case we cannot do much, we enter C3
 582                  * without doing anything.
 583                  */
 584                 if (pr->flags.bm_check && pr->flags.bm_control) {
 585                         if (atomic_inc_return(&c3_cpu_count) ==
 586                             num_online_cpus()) {
 587                                 /*
 588                                  * All CPUs are trying to go to C3
 589                                  * Disable bus master arbitration
 590                                  */
 591                                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
 592                         }
 593                 } else if (!pr->flags.bm_check) {
 594                         /* SMP with no shared cache... Invalidate cache  */
 595                         ACPI_FLUSH_CPU_CACHE();
 596                 }
 597
 598                 /* Get start time (ticks) */
 599                 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 600                 /* Invoke C3 */
 601                 /* Tell the scheduler that we are going deep-idle: */
 602                 sched_clock_idle_sleep_event();
 603                 acpi_cstate_enter(cx);
 604                 /* Get end time (ticks) */
 605                 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 606                 if (pr->flags.bm_check && pr->flags.bm_control) {
 607                         /* Enable bus master arbitration */
 608                         atomic_dec(&c3_cpu_count);
 609                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
 610                 }
 611
 612 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
 613                 /* TSC halts in C3, so notify users */
 614                 if (tsc_halts_in_c(ACPI_STATE_C3))
 615                         mark_tsc_unstable("TSC halts in C3");
 616 #endif
 617                 /* Compute time (ticks) that we were actually asleep */
 618                 sleep_ticks = ticks_elapsed(t1, t2);
 619                 /* Tell the scheduler how much we idled: */
 620                 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 621
 622                 /* Re-enable interrupts */
 623                 local_irq_enable();
 624                 /* Do not account our idle-switching overhead: */
 625                 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
 626
 627                 current_thread_info()->status |= TS_POLLING;
 628                 acpi_state_timer_broadcast(pr, cx, 0);
 629                 break;
 630
 631         default:
 632                 local_irq_enable();
 633                 return;
 634         }
 635         cx->usage++;
 636         if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
 637                 cx->time += sleep_ticks;
 638
 639         next_state = pr->power.state;
 640
 641 #ifdef CONFIG_HOTPLUG_CPU
 642         /* Don't do promotion/demotion */
 643         if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 644             !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
 645                 next_state = cx;
 646                 goto end;
 647         }
 648 #endif
 649
 650         /*
 651          * Promotion?
 652          * ----------
 653          * Track the number of longs (time asleep is greater than threshold)
 654          * and promote when the count threshold is reached.  Note that bus
 655          * mastering activity may prevent promotions.
 656          * Do not promote above max_cstate.
 657          */
 658         if (cx->promotion.state &&
 659             ((cx->promotion.state - pr->power.states) <= max_cstate)) {
 660                 if (sleep_ticks > cx->promotion.threshold.ticks &&
 661                   cx->promotion.state->latency <=
 662                                 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
 663                         cx->promotion.count++;
 664                         cx->demotion.count = 0;
 665                         if (cx->promotion.count >=
 666                             cx->promotion.threshold.count) {
 667                                 if (pr->flags.bm_check) {
 668                                         if (!
 669                                             (pr->power.bm_activity & cx->
 670                                              promotion.threshold.bm)) {
 671                                                 next_state =
 672                                                     cx->promotion.state;
 673                                                 goto end;
 674                                         }
 675                                 } else {
 676                                         next_state = cx->promotion.state;
 677                                         goto end;
 678                                 }
 679                         }
 680                 }
 681         }
 682
 683         /*
 684          * Demotion?
 685          * ---------
 686          * Track the number of shorts (time asleep is less than time threshold)
 687          * and demote when the usage threshold is reached.
 688          */
 689         if (cx->demotion.state) {
 690                 if (sleep_ticks < cx->demotion.threshold.ticks) {
 691                         cx->demotion.count++;
 692                         cx->promotion.count = 0;
 693                         if (cx->demotion.count >= cx->demotion.threshold.count) {
 694                                 next_state = cx->demotion.state;
 695                                 goto end;
 696                         }
 697                 }
 698         }
 699
 700       end:
 701         /*
 702          * Demote if current state exceeds max_cstate
 703          * or if the latency of the current state is unacceptable
 704          */
 705         if ((pr->power.state - pr->power.states) > max_cstate ||
 706                 pr->power.state->latency >
 707                                 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
 708                 if (cx->demotion.state)
 709                         next_state = cx->demotion.state;
 710         }
 711
 712         /*
 713          * New Cx State?
 714          * -------------
 715          * If we're going to start using a new Cx state we must clean up
 716          * from the previous and prepare to use the new.
 717          */
 718         if (next_state != pr->power.state)
 719                 acpi_processor_power_activate(pr, next_state);
 720 }
 721
 722 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
 723 {
 724         unsigned int i;
 725         unsigned int state_is_set = 0;
 726         struct acpi_processor_cx *lower = NULL;
 727         struct acpi_processor_cx *higher = NULL;
 728         struct acpi_processor_cx *cx;
 729
 730
 731         if (!pr)
 732                 return -EINVAL;
 733
 734         /*
 735          * This function sets the default Cx state policy (OS idle handler).
 736          * Our scheme is to promote quickly to C2 but more conservatively
 737          * to C3.  We're favoring C2  for its characteristics of low latency
 738          * (quick response), good power savings, and ability to allow bus
 739          * mastering activity.  Note that the Cx state policy is completely
 740          * customizable and can be altered dynamically.
 741          */
 742
 743         /* startup state */
 744         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 745                 cx = &pr->power.states[i];
 746                 if (!cx->valid)
 747                         continue;
 748
 749                 if (!state_is_set)
 750                         pr->power.state = cx;
 751                 state_is_set++;
 752                 break;
 753         }
 754
 755         if (!state_is_set)
 756                 return -ENODEV;
 757
 758         /* demotion */
 759         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 760                 cx = &pr->power.states[i];
 761                 if (!cx->valid)
 762                         continue;
 763
 764                 if (lower) {
 765                         cx->demotion.state = lower;
 766                         cx->demotion.threshold.ticks = cx->latency_ticks;
 767                         cx->demotion.threshold.count = 1;
 768                         if (cx->type == ACPI_STATE_C3)
 769                                 cx->demotion.threshold.bm = bm_history;
 770                 }
 771
 772                 lower = cx;
 773         }
 774
 775         /* promotion */
 776         for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
 777                 cx = &pr->power.states[i];
 778                 if (!cx->valid)
 779                         continue;
 780
 781                 if (higher) {
 782                         cx->promotion.state = higher;
 783                         cx->promotion.threshold.ticks = cx->latency_ticks;
 784                         if (cx->type >= ACPI_STATE_C2)
 785                                 cx->promotion.threshold.count = 4;
 786                         else
 787                                 cx->promotion.threshold.count = 10;
 788                         if (higher->type == ACPI_STATE_C3)
 789                                 cx->promotion.threshold.bm = bm_history;
 790                 }
 791
 792                 higher = cx;
 793         }
 794
 795         return 0;
 796 }
 797 #endif /* !CONFIG_CPU_IDLE */
 798
 799 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 800 {
 801
 802         if (!pr)
 803                 return -EINVAL;
 804
 805         if (!pr->pblk)
 806                 return -ENODEV;
 807
 808         /* if info is obtained from pblk/fadt, type equals state */
 809         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 810         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 811
 812 #ifndef CONFIG_HOTPLUG_CPU
 813         /*
 814          * Check for P_LVL2_UP flag before entering C2 and above on
 815          * an SMP system.
 816          */
 817         if ((num_online_cpus() > 1) &&
 818             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 819                 return -ENODEV;
 820 #endif
 821
 822         /* determine C2 and C3 address from pblk */
 823         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 824         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 825
 826         /* determine latencies from FADT */
 827         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 828         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 829
 830         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 831                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 832                           pr->power.states[ACPI_STATE_C2].address,
 833                           pr->power.states[ACPI_STATE_C3].address));
 834
 835         return 0;
 836 }
 837
 838 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 839 {
 840         if (!pr->power.states[ACPI_STATE_C1].valid) {
 841                 /* set the first C-State to C1 */
 842                 /* all processors need to support C1 */
 843                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 844                 pr->power.states[ACPI_STATE_C1].valid = 1;
 845         }
 846         /* the C0 state only exists as a filler in our array */
 847         pr->power.states[ACPI_STATE_C0].valid = 1;
 848         return 0;
 849 }
 850
 851 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 852 {
 853         acpi_status status = 0;
 854         acpi_integer count;
 855         int current_count;
 856         int i;
 857         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 858         union acpi_object *cst;
 859
 860
 861         if (nocst)
 862                 return -ENODEV;
 863
 864         current_count = 0;
 865
 866         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 867         if (ACPI_FAILURE(status)) {
 868                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 869                 return -ENODEV;
 870         }
 871
 872         cst = buffer.pointer;
 873
 874         /* There must be at least 2 elements */
 875         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 876                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 877                 status = -EFAULT;
 878                 goto end;
 879         }
 880
 881         count = cst->package.elements[0].integer.value;
 882
 883         /* Validate number of power states. */
 884         if (count < 1 || count != cst->package.count - 1) {
 885                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 886                 status = -EFAULT;
 887                 goto end;
 888         }
 889
 890         /* Tell driver that at least _CST is supported. */
 891         pr->flags.has_cst = 1;
 892
 893         for (i = 1; i <= count; i++) {
 894                 union acpi_object *element;
 895                 union acpi_object *obj;
 896                 struct acpi_power_register *reg;
 897                 struct acpi_processor_cx cx;
 898
 899                 memset(&cx, 0, sizeof(cx));
 900
 901                 element = &(cst->package.elements[i]);
 902                 if (element->type != ACPI_TYPE_PACKAGE)
 903                         continue;
 904
 905                 if (element->package.count != 4)
 906                         continue;
 907
 908                 obj = &(element->package.elements[0]);
 909
 910                 if (obj->type != ACPI_TYPE_BUFFER)
 911                         continue;
 912
 913                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 914
 915                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 916                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 917                         continue;
 918
 919                 /* There should be an easy way to extract an integer... */
 920                 obj = &(element->package.elements[1]);
 921                 if (obj->type != ACPI_TYPE_INTEGER)
 922                         continue;
 923
 924                 cx.type = obj->integer.value;
 925                 /*
 926                  * Some buggy BIOSes won't list C1 in _CST -
 927                  * Let acpi_processor_get_power_info_default() handle them later
 928                  */
 929                 if (i == 1 && cx.type != ACPI_STATE_C1)
 930                         current_count++;
 931
 932                 cx.address = reg->address;
 933                 cx.index = current_count + 1;
 934
 935                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 936                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 937                         if (acpi_processor_ffh_cstate_probe
 938                                         (pr->id, &cx, reg) == 0) {
 939                                 cx.entry_method = ACPI_CSTATE_FFH;
 940                         } else if (cx.type == ACPI_STATE_C1) {
 941                                 /*
 942                                  * C1 is a special case where FIXED_HARDWARE
 943                                  * can be handled in non-MWAIT way as well.
 944                                  * In that case, save this _CST entry info.
 945                                  * Otherwise, ignore this info and continue.
 946                                  */
 947                                 cx.entry_method = ACPI_CSTATE_HALT;
 948                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 949                         } else {
 950                                 continue;
 951                         }
 952                 } else {
 953                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 954                                  cx.address);
 955                 }
 956
 957
 958                 obj = &(element->package.elements[2]);
 959                 if (obj->type != ACPI_TYPE_INTEGER)
 960                         continue;
 961
 962                 cx.latency = obj->integer.value;
 963
 964                 obj = &(element->package.elements[3]);
 965                 if (obj->type != ACPI_TYPE_INTEGER)
 966                         continue;
 967
 968                 cx.power = obj->integer.value;
 969
 970                 current_count++;
 971                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 972
 973                 /*
 974                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 975                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 976                  */
 977                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 978                         printk(KERN_WARNING
 979                                "Limiting number of power states to max (%d)\n",
 980                                ACPI_PROCESSOR_MAX_POWER);
 981                         printk(KERN_WARNING
 982                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 983                         break;
 984                 }
 985         }
 986
 987         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 988                           current_count));
 989
 990         /* Validate number of power states discovered */
 991         if (current_count < 2)
 992                 status = -EFAULT;
 993
 994       end:
 995         kfree(buffer.pointer);
 996
 997         return status;
 998 }
 999
1000 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
1001 {
1002
1003         if (!cx->address)
1004                 return;
1005
1006         /*
1007          * C2 latency must be less than or equal to 100
1008          * microseconds.
1009          */
1010         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
1011                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1012                                   "latency too large [%d]\n", cx->latency));
1013                 return;
1014         }
1015
1016         /*
1017          * Otherwise we've met all of our C2 requirements.
1018          * Normalize the C2 latency to expidite policy
1019          */
1020         cx->valid = 1;
1021
1022 #ifndef CONFIG_CPU_IDLE
1023         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1024 #else
1025         cx->latency_ticks = cx->latency;
1026 #endif
1027
1028         return;
1029 }
1030
1031 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
1032                                            struct acpi_processor_cx *cx)
1033 {
1034         static int bm_check_flag;
1035
1036
1037         if (!cx->address)
1038                 return;
1039
1040         /*
1041          * C3 latency must be less than or equal to 1000
1042          * microseconds.
1043          */
1044         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
1045                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1046                                   "latency too large [%d]\n", cx->latency));
1047                 return;
1048         }
1049
1050         /*
1051          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
1052          * DMA transfers are used by any ISA device to avoid livelock.
1053          * Note that we could disable Type-F DMA (as recommended by
1054          * the erratum), but this is known to disrupt certain ISA
1055          * devices thus we take the conservative approach.
1056          */
1057         else if (errata.piix4.fdma) {
1058                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1059                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
1060                 return;
1061         }
1062
1063         /* All the logic here assumes flags.bm_check is same across all CPUs */
1064         if (!bm_check_flag) {
1065                 /* Determine whether bm_check is needed based on CPU  */
1066                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
1067                 bm_check_flag = pr->flags.bm_check;
1068         } else {
1069                 pr->flags.bm_check = bm_check_flag;
1070         }
1071
1072         if (pr->flags.bm_check) {
1073                 if (!pr->flags.bm_control) {
1074                         if (pr->flags.has_cst != 1) {
1075                                 /* bus mastering control is necessary */
1076                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1077                                         "C3 support requires BM control\n"));
1078                                 return;
1079                         } else {
1080                                 /* Here we enter C3 without bus mastering */
1081                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1082                                         "C3 support without BM control\n"));
1083                         }
1084                 }
1085         } else {
1086                 /*
1087                  * WBINVD should be set in fadt, for C3 state to be
1088                  * supported on when bm_check is not required.
1089                  */
1090                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
1091                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1092                                           "Cache invalidation should work properly"
1093                                           " for C3 to be enabled on SMP systems\n"));
1094                         return;
1095                 }
1096                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1097         }
1098
1099         /*
1100          * Otherwise we've met all of our C3 requirements.
1101          * Normalize the C3 latency to expidite policy.  Enable
1102          * checking of bus mastering status (bm_check) so we can
1103          * use this in our C3 policy
1104          */
1105         cx->valid = 1;
1106
1107 #ifndef CONFIG_CPU_IDLE
1108         cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
1109 #else
1110         cx->latency_ticks = cx->latency;
1111 #endif
1112
1113         return;
1114 }
1115
1116 static int acpi_processor_power_verify(struct acpi_processor *pr)
1117 {
1118         unsigned int i;
1119         unsigned int working = 0;
1120
1121         pr->power.timer_broadcast_on_state = INT_MAX;
1122
1123         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1124                 struct acpi_processor_cx *cx = &pr->power.states[i];
1125
1126                 switch (cx->type) {
1127                 case ACPI_STATE_C1:
1128                         cx->valid = 1;
1129                         break;
1130
1131                 case ACPI_STATE_C2:
1132                         acpi_processor_power_verify_c2(cx);
1133                         if (cx->valid)
1134                                 acpi_timer_check_state(i, pr, cx);
1135                         break;
1136
1137                 case ACPI_STATE_C3:
1138                         acpi_processor_power_verify_c3(pr, cx);
1139                         if (cx->valid)
1140                                 acpi_timer_check_state(i, pr, cx);
1141                         break;
1142                 }
1143
1144                 if (cx->valid)
1145                         working++;
1146         }
1147
1148         acpi_propagate_timer_broadcast(pr);
1149
1150         return (working);
1151 }
1152
1153 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1154 {
1155         unsigned int i;
1156         int result;
1157
1158
1159         /* NOTE: the idle thread may not be running while calling
1160          * this function */
1161
1162         /* Zero initialize all the C-states info. */
1163         memset(pr->power.states, 0, sizeof(pr->power.states));
1164
1165         result = acpi_processor_get_power_info_cst(pr);
1166         if (result == -ENODEV)
1167                 result = acpi_processor_get_power_info_fadt(pr);
1168
1169         if (result)
1170                 return result;
1171
1172         acpi_processor_get_power_info_default(pr);
1173
1174         pr->power.count = acpi_processor_power_verify(pr);
1175
1176 #ifndef CONFIG_CPU_IDLE
1177         /*
1178          * Set Default Policy
1179          * ------------------
1180          * Now that we know which states are supported, set the default
1181          * policy.  Note that this policy can be changed dynamically
1182          * (e.g. encourage deeper sleeps to conserve battery life when
1183          * not on AC).
1184          */
1185         result = acpi_processor_set_power_policy(pr);
1186         if (result)
1187                 return result;
1188 #endif
1189
1190         /*
1191          * if one state of type C2 or C3 is available, mark this
1192          * CPU as being "idle manageable"
1193          */
1194         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
1195                 if (pr->power.states[i].valid) {
1196                         pr->power.count = i;
1197                         if (pr->power.states[i].type >= ACPI_STATE_C2)
1198                                 pr->flags.power = 1;
1199                 }
1200         }
1201
1202         return 0;
1203 }
1204
1205 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1206 {
1207         struct acpi_processor *pr = seq->private;
1208         unsigned int i;
1209
1210
1211         if (!pr)
1212                 goto end;
1213
1214         seq_printf(seq, "active state:            C%zd\n"
1215                    "max_cstate:              C%d\n"
1216                    "bus master activity:     %08x\n"
1217                    "maximum allowed latency: %d usec\n",
1218                    pr->power.state ? pr->power.state - pr->power.states : 0,
1219                    max_cstate, (unsigned)pr->power.bm_activity,
1220                    pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
1221
1222         seq_puts(seq, "states:\n");
1223
1224         for (i = 1; i <= pr->power.count; i++) {
1225                 seq_printf(seq, "   %cC%d:                  ",
1226                            (&pr->power.states[i] ==
1227                             pr->power.state ? '*' : ' '), i);
1228
1229                 if (!pr->power.states[i].valid) {
1230                         seq_puts(seq, "<not supported>\n");
1231                         continue;
1232                 }
1233
1234                 switch (pr->power.states[i].type) {
1235                 case ACPI_STATE_C1:
1236                         seq_printf(seq, "type[C1] ");
1237                         break;
1238                 case ACPI_STATE_C2:
1239                         seq_printf(seq, "type[C2] ");
1240                         break;
1241                 case ACPI_STATE_C3:
1242                         seq_printf(seq, "type[C3] ");
1243                         break;
1244                 default:
1245                         seq_printf(seq, "type[--] ");
1246                         break;
1247                 }
1248
1249                 if (pr->power.states[i].promotion.state)
1250                         seq_printf(seq, "promotion[C%zd] ",
1251                                    (pr->power.states[i].promotion.state -
1252                                     pr->power.states));
1253                 else
1254                         seq_puts(seq, "promotion[--] ");
1255
1256                 if (pr->power.states[i].demotion.state)
1257                         seq_printf(seq, "demotion[C%zd] ",
1258                                    (pr->power.states[i].demotion.state -
1259                                     pr->power.states));
1260                 else
1261                         seq_puts(seq, "demotion[--] ");
1262
1263                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
1264                            pr->power.states[i].latency,
1265                            pr->power.states[i].usage,
1266                            (unsigned long long)pr->power.states[i].time);
1267         }
1268
1269       end:
1270         return 0;
1271 }
1272
1273 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1274 {
1275         return single_open(file, acpi_processor_power_seq_show,
1276                            PDE(inode)->data);
1277 }
1278
1279 static const struct file_operations acpi_processor_power_fops = {
1280         .open = acpi_processor_power_open_fs,
1281         .read = seq_read,
1282         .llseek = seq_lseek,
1283         .release = single_release,
1284 };
1285
1286 #ifndef CONFIG_CPU_IDLE
1287
1288 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1289 {
1290         int result = 0;
1291
1292
1293         if (!pr)
1294                 return -EINVAL;
1295
1296         if (nocst) {
1297                 return -ENODEV;
1298         }
1299
1300         if (!pr->flags.power_setup_done)
1301                 return -ENODEV;
1302
1303         /* Fall back to the default idle loop */
1304         pm_idle = pm_idle_save;
1305         synchronize_sched();    /* Relies on interrupts forcing exit from idle. */
1306
1307         pr->flags.power = 0;
1308         result = acpi_processor_get_power_info(pr);
1309         if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1310                 pm_idle = acpi_processor_idle;
1311
1312         return result;
1313 }
1314
1315 #ifdef CONFIG_SMP
1316 static void smp_callback(void *v)
1317 {
1318         /* we already woke the CPU up, nothing more to do */
1319 }
1320
1321 /*
1322  * This function gets called when a part of the kernel has a new latency
1323  * requirement.  This means we need to get all processors out of their C-state,
1324  * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1325  * wakes them all right up.
1326  */
1327 static int acpi_processor_latency_notify(struct notifier_block *b,
1328                 unsigned long l, void *v)
1329 {
1330         smp_call_function(smp_callback, NULL, 0, 1);
1331         return NOTIFY_OK;
1332 }
1333
1334 static struct notifier_block acpi_processor_latency_notifier = {
1335         .notifier_call = acpi_processor_latency_notify,
1336 };
1337
1338 #endif
1339
1340 #else /* CONFIG_CPU_IDLE */
1341
1342 /**
1343  * acpi_idle_bm_check - checks if bus master activity was detected
1344  */
1345 static int acpi_idle_bm_check(void)
1346 {
1347         u32 bm_status = 0;
1348
1349         acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
1350         if (bm_status)
1351                 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1352         /*
1353          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
1354          * the true state of bus mastering activity; forcing us to
1355          * manually check the BMIDEA bit of each IDE channel.
1356          */
1357         else if (errata.piix4.bmisx) {
1358                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
1359                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
1360                         bm_status = 1;
1361         }
1362         return bm_status;
1363 }
1364
1365 /**
1366  * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
1367  * @pr: the processor
1368  * @target: the new target state
1369  */
1370 static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
1371                                            struct acpi_processor_cx *target)
1372 {
1373         if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
1374                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
1375                 pr->flags.bm_rld_set = 0;
1376         }
1377
1378         if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
1379                 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
1380                 pr->flags.bm_rld_set = 1;
1381         }
1382 }
1383
1384 /**
1385  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
1386  * @cx: cstate data
1387  *
1388  * Caller disables interrupt before call and enables interrupt after return.
1389  */
1390 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
1391 {
1392         if (cx->entry_method == ACPI_CSTATE_FFH) {
1393                 /* Call into architectural FFH based C-state */
1394                 acpi_processor_ffh_cstate_enter(cx);
1395         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
1396                 acpi_safe_halt();
1397         } else {
1398                 int unused;
1399                 /* IO port based C-state */
1400                 inb(cx->address);
1401                 /* Dummy wait op - must do something useless after P_LVL2 read
1402                    because chipsets cannot guarantee that STPCLK# signal
1403                    gets asserted in time to freeze execution properly. */
1404                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
1405         }
1406 }
1407
1408 /**
1409  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
1410  * @dev: the target CPU
1411  * @state: the state data
1412  *
1413  * This is equivalent to the HALT instruction.
1414  */
1415 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
1416                               struct cpuidle_state *state)
1417 {
1418         u32 t1, t2;
1419         struct acpi_processor *pr;
1420         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1421
1422         pr = processors[smp_processor_id()];
1423
1424         if (unlikely(!pr))
1425                 return 0;
1426
1427         local_irq_disable();
1428
1429         /* Do not access any ACPI IO ports in suspend path */
1430         if (acpi_idle_suspend) {
1431                 acpi_safe_halt();
1432                 local_irq_enable();
1433                 return 0;
1434         }
1435
1436         if (pr->flags.bm_check)
1437                 acpi_idle_update_bm_rld(pr, cx);
1438
1439         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1440         acpi_idle_do_entry(cx);
1441         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1442
1443         local_irq_enable();
1444         cx->usage++;
1445
1446         return ticks_elapsed_in_us(t1, t2);
1447 }
1448
1449 /**
1450  * acpi_idle_enter_simple - enters an ACPI state without BM handling
1451  * @dev: the target CPU
1452  * @state: the state data
1453  */
1454 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
1455                                   struct cpuidle_state *state)
1456 {
1457         struct acpi_processor *pr;
1458         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1459         u32 t1, t2;
1460         int sleep_ticks = 0;
1461
1462         pr = processors[smp_processor_id()];
1463
1464         if (unlikely(!pr))
1465                 return 0;
1466
1467         if (acpi_idle_suspend)
1468                 return(acpi_idle_enter_c1(dev, state));
1469
1470         local_irq_disable();
1471         current_thread_info()->status &= ~TS_POLLING;
1472         /*
1473          * TS_POLLING-cleared state must be visible before we test
1474          * NEED_RESCHED:
1475          */
1476         smp_mb();
1477
1478         if (unlikely(need_resched())) {
1479                 current_thread_info()->status |= TS_POLLING;
1480                 local_irq_enable();
1481                 return 0;
1482         }
1483
1484         acpi_unlazy_tlb(smp_processor_id());
1485         /*
1486          * Must be done before busmaster disable as we might need to
1487          * access HPET !
1488          */
1489         acpi_state_timer_broadcast(pr, cx, 1);
1490
1491         if (pr->flags.bm_check)
1492                 acpi_idle_update_bm_rld(pr, cx);
1493
1494         if (cx->type == ACPI_STATE_C3)
1495                 ACPI_FLUSH_CPU_CACHE();
1496
1497         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1498         /* Tell the scheduler that we are going deep-idle: */
1499         sched_clock_idle_sleep_event();
1500         acpi_idle_do_entry(cx);
1501         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1502
1503 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
1504         /* TSC could halt in idle, so notify users */
1505         if (tsc_halts_in_c(cx->type))
1506                 mark_tsc_unstable("TSC halts in idle");;
1507 #endif
1508         sleep_ticks = ticks_elapsed(t1, t2);
1509
1510         /* Tell the scheduler how much we idled: */
1511         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1512
1513         local_irq_enable();
1514         current_thread_info()->status |= TS_POLLING;
1515
1516         cx->usage++;
1517
1518         acpi_state_timer_broadcast(pr, cx, 0);
1519         cx->time += sleep_ticks;
1520         return ticks_elapsed_in_us(t1, t2);
1521 }
1522
1523 static int c3_cpu_count;
1524 static DEFINE_SPINLOCK(c3_lock);
1525
1526 /**
1527  * acpi_idle_enter_bm - enters C3 with proper BM handling
1528  * @dev: the target CPU
1529  * @state: the state data
1530  *
1531  * If BM is detected, the deepest non-C3 idle state is entered instead.
1532  */
1533 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
1534                               struct cpuidle_state *state)
1535 {
1536         struct acpi_processor *pr;
1537         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
1538         u32 t1, t2;
1539         int sleep_ticks = 0;
1540
1541         pr = processors[smp_processor_id()];
1542
1543         if (unlikely(!pr))
1544                 return 0;
1545
1546         if (acpi_idle_suspend)
1547                 return(acpi_idle_enter_c1(dev, state));
1548
1549         if (acpi_idle_bm_check()) {
1550                 if (dev->safe_state) {
1551                         return dev->safe_state->enter(dev, dev->safe_state);
1552                 } else {
1553                         local_irq_disable();
1554                         acpi_safe_halt();
1555                         local_irq_enable();
1556                         return 0;
1557                 }
1558         }
1559
1560         local_irq_disable();
1561         current_thread_info()->status &= ~TS_POLLING;
1562         /*
1563          * TS_POLLING-cleared state must be visible before we test
1564          * NEED_RESCHED:
1565          */
1566         smp_mb();
1567
1568         if (unlikely(need_resched())) {
1569                 current_thread_info()->status |= TS_POLLING;
1570                 local_irq_enable();
1571                 return 0;
1572         }
1573
1574         /* Tell the scheduler that we are going deep-idle: */
1575         sched_clock_idle_sleep_event();
1576         /*
1577          * Must be done before busmaster disable as we might need to
1578          * access HPET !
1579          */
1580         acpi_state_timer_broadcast(pr, cx, 1);
1581
1582         acpi_idle_update_bm_rld(pr, cx);
1583
1584         /*
1585          * disable bus master
1586          * bm_check implies we need ARB_DIS
1587          * !bm_check implies we need cache flush
1588          * bm_control implies whether we can do ARB_DIS
1589          *
1590          * That leaves a case where bm_check is set and bm_control is
1591          * not set. In that case we cannot do much, we enter C3
1592          * without doing anything.
1593          */
1594         if (pr->flags.bm_check && pr->flags.bm_control) {
1595                 spin_lock(&c3_lock);
1596                 c3_cpu_count++;
1597                 /* Disable bus master arbitration when all CPUs are in C3 */
1598                 if (c3_cpu_count == num_online_cpus())
1599                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
1600                 spin_unlock(&c3_lock);
1601         } else if (!pr->flags.bm_check) {
1602                 ACPI_FLUSH_CPU_CACHE();
1603         }
1604
1605         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1606         acpi_idle_do_entry(cx);
1607         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1608
1609         /* Re-enable bus master arbitration */
1610         if (pr->flags.bm_check && pr->flags.bm_control) {
1611                 spin_lock(&c3_lock);
1612                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
1613                 c3_cpu_count--;
1614                 spin_unlock(&c3_lock);
1615         }
1616
1617 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
1618         /* TSC could halt in idle, so notify users */
1619         if (tsc_halts_in_c(ACPI_STATE_C3))
1620                 mark_tsc_unstable("TSC halts in idle");
1621 #endif
1622         sleep_ticks = ticks_elapsed(t1, t2);
1623         /* Tell the scheduler how much we idled: */
1624         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1625
1626         local_irq_enable();
1627         current_thread_info()->status |= TS_POLLING;
1628
1629         cx->usage++;
1630
1631         acpi_state_timer_broadcast(pr, cx, 0);
1632         cx->time += sleep_ticks;
1633         return ticks_elapsed_in_us(t1, t2);
1634 }
1635
1636 struct cpuidle_driver acpi_idle_driver = {
1637         .name =         "acpi_idle",
1638         .owner =        THIS_MODULE,
1639 };
1640
1641 /**
1642  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1643  * @pr: the ACPI processor
1644  */
1645 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1646 {
1647         int i, count = CPUIDLE_DRIVER_STATE_START;
1648         struct acpi_processor_cx *cx;
1649         struct cpuidle_state *state;
1650         struct cpuidle_device *dev = &pr->power.dev;
1651
1652         if (!pr->flags.power_setup_done)
1653                 return -EINVAL;
1654
1655         if (pr->flags.power == 0) {
1656                 return -EINVAL;
1657         }
1658
1659         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1660                 dev->states[i].name[0] = '\0';
1661                 dev->states[i].desc[0] = '\0';
1662         }
1663
1664         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1665                 cx = &pr->power.states[i];
1666                 state = &dev->states[count];
1667
1668                 if (!cx->valid)
1669                         continue;
1670
1671 #ifdef CONFIG_HOTPLUG_CPU
1672                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1673                     !pr->flags.has_cst &&
1674                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1675                         continue;
1676 #endif
1677                 cpuidle_set_statedata(state, cx);
1678
1679                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1680                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1681                 state->exit_latency = cx->latency;
1682                 state->target_residency = cx->latency * latency_factor;
1683                 state->power_usage = cx->power;
1684
1685                 state->flags = 0;
1686                 switch (cx->type) {
1687                         case ACPI_STATE_C1:
1688                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1689                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1690                         state->enter = acpi_idle_enter_c1;
1691                         dev->safe_state = state;
1692                         break;
1693
1694                         case ACPI_STATE_C2:
1695                         state->flags |= CPUIDLE_FLAG_BALANCED;
1696                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1697                         state->enter = acpi_idle_enter_simple;
1698                         dev->safe_state = state;
1699                         break;
1700
1701                         case ACPI_STATE_C3:
1702                         state->flags |= CPUIDLE_FLAG_DEEP;
1703                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1704                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1705                         state->enter = pr->flags.bm_check ?
1706                                         acpi_idle_enter_bm :
1707                                         acpi_idle_enter_simple;
1708                         break;
1709                 }
1710
1711                 count++;
1712                 if (count == CPUIDLE_STATE_MAX)
1713                         break;
1714         }
1715
1716         dev->state_count = count;
1717
1718         if (!count)
1719                 return -EINVAL;
1720
1721         return 0;
1722 }
1723
1724 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1725 {
1726         int ret;
1727
1728         if (!pr)
1729                 return -EINVAL;
1730
1731         if (nocst) {
1732                 return -ENODEV;
1733         }
1734
1735         if (!pr->flags.power_setup_done)
1736                 return -ENODEV;
1737
1738         cpuidle_pause_and_lock();
1739         cpuidle_disable_device(&pr->power.dev);
1740         acpi_processor_get_power_info(pr);
1741         acpi_processor_setup_cpuidle(pr);
1742         ret = cpuidle_enable_device(&pr->power.dev);
1743         cpuidle_resume_and_unlock();
1744
1745         return ret;
1746 }
1747
1748 #endif /* CONFIG_CPU_IDLE */
1749
1750 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1751                               struct acpi_device *device)
1752 {
1753         acpi_status status = 0;
1754         static int first_run;
1755         struct proc_dir_entry *entry = NULL;
1756         unsigned int i;
1757
1758
1759         if (!first_run) {
1760                 dmi_check_system(processor_power_dmi_table);
1761                 max_cstate = acpi_processor_cstate_check(max_cstate);
1762                 if (max_cstate < ACPI_C_STATES_MAX)
1763                         printk(KERN_NOTICE
1764                                "ACPI: processor limited to max C-state %d\n",
1765                                max_cstate);
1766                 first_run++;
1767 #if !defined(CONFIG_CPU_IDLE) && defined(CONFIG_SMP)
1768                 pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY,
1769                                 &acpi_processor_latency_notifier);
1770 #endif
1771         }
1772
1773         if (!pr)
1774                 return -EINVAL;
1775
1776         if (acpi_gbl_FADT.cst_control && !nocst) {
1777                 status =
1778                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1779                 if (ACPI_FAILURE(status)) {
1780                         ACPI_EXCEPTION((AE_INFO, status,
1781                                         "Notifying BIOS of _CST ability failed"));
1782                 }
1783         }
1784
1785         acpi_processor_get_power_info(pr);
1786         pr->flags.power_setup_done = 1;
1787
1788         /*
1789          * Install the idle handler if processor power management is supported.
1790          * Note that we use previously set idle handler will be used on
1791          * platforms that only support C1.
1792          */
1793         if ((pr->flags.power) && (!boot_option_idle_override)) {
1794 #ifdef CONFIG_CPU_IDLE
1795                 acpi_processor_setup_cpuidle(pr);
1796                 pr->power.dev.cpu = pr->id;
1797                 if (cpuidle_register_device(&pr->power.dev))
1798                         return -EIO;
1799 #endif
1800
1801                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1802                 for (i = 1; i <= pr->power.count; i++)
1803                         if (pr->power.states[i].valid)
1804                                 printk(" C%d[C%d]", i,
1805                                        pr->power.states[i].type);
1806                 printk(")\n");
1807
1808 #ifndef CONFIG_CPU_IDLE
1809                 if (pr->id == 0) {
1810                         pm_idle_save = pm_idle;
1811                         pm_idle = acpi_processor_idle;
1812                 }
1813 #endif
1814         }
1815
1816         /* 'power' [R] */
1817         entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1818                                   S_IRUGO, acpi_device_dir(device));
1819         if (!entry)
1820                 return -EIO;
1821         else {
1822                 entry->proc_fops = &acpi_processor_power_fops;
1823                 entry->data = acpi_driver_data(device);
1824                 entry->owner = THIS_MODULE;
1825         }
1826
1827         return 0;
1828 }
1829
1830 int acpi_processor_power_exit(struct acpi_processor *pr,
1831                               struct acpi_device *device)
1832 {
1833 #ifdef CONFIG_CPU_IDLE
1834         if ((pr->flags.power) && (!boot_option_idle_override))
1835                 cpuidle_unregister_device(&pr->power.dev);
1836 #endif
1837         pr->flags.power_setup_done = 0;
1838
1839         if (acpi_device_dir(device))
1840                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1841                                   acpi_device_dir(device));
1842
1843 #ifndef CONFIG_CPU_IDLE
1844
1845         /* Unregister the idle handler when processor #0 is removed. */
1846         if (pr->id == 0) {
1847                 pm_idle = pm_idle_save;
1848
1849                 /*
1850                  * We are about to unload the current idle thread pm callback
1851                  * (pm_idle), Wait for all processors to update cached/local
1852                  * copies of pm_idle before proceeding.
1853                  */
1854                 cpu_idle_wait();
1855 #ifdef CONFIG_SMP
1856                 pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY,
1857                                 &acpi_processor_latency_notifier);
1858 #endif
1859         }
1860 #endif
1861
1862         return 0;
1863 }