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 #define C2_OVERHEAD                     1       /* 1us */
  70 #define C3_OVERHEAD                     1       /* 1us */
  71 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  72
  73 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  74 module_param(max_cstate, uint, 0000);
  75 static unsigned int nocst __read_mostly;
  76 module_param(nocst, uint, 0000);
  77
  78 static unsigned int latency_factor __read_mostly = 2;
  79 module_param(latency_factor, uint, 0644);
  80
  81 /*
  82  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  83  * For now disable this. Probably a bug somewhere else.
  84  *
  85  * To skip this limit, boot/load with a large max_cstate limit.
  86  */
  87 static int set_max_cstate(const struct dmi_system_id *id)
  88 {
  89         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  90                 return 0;
  91
  92         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  93                " Override with \"processor.max_cstate=%d\"\n", id->ident,
  94                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  95
  96         max_cstate = (long)id->driver_data;
  97
  98         return 0;
  99 }
 100
 101 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 102    callers to only run once -AK */
 103 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 104         { set_max_cstate, "IBM ThinkPad R40e", {
 105           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 106           DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
 107         { set_max_cstate, "IBM ThinkPad R40e", {
 108           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 109           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
 110         { set_max_cstate, "IBM ThinkPad R40e", {
 111           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 112           DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
 113         { set_max_cstate, "IBM ThinkPad R40e", {
 114           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 115           DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
 116         { set_max_cstate, "IBM ThinkPad R40e", {
 117           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 118           DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
 119         { set_max_cstate, "IBM ThinkPad R40e", {
 120           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 121           DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
 122         { set_max_cstate, "IBM ThinkPad R40e", {
 123           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 124           DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
 125         { set_max_cstate, "IBM ThinkPad R40e", {
 126           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 127           DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
 128         { set_max_cstate, "IBM ThinkPad R40e", {
 129           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 130           DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
 131         { set_max_cstate, "IBM ThinkPad R40e", {
 132           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 133           DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
 134         { set_max_cstate, "IBM ThinkPad R40e", {
 135           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 136           DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
 137         { set_max_cstate, "IBM ThinkPad R40e", {
 138           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 139           DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
 140         { set_max_cstate, "IBM ThinkPad R40e", {
 141           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 142           DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
 143         { set_max_cstate, "IBM ThinkPad R40e", {
 144           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 145           DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
 146         { set_max_cstate, "IBM ThinkPad R40e", {
 147           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 148           DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
 149         { set_max_cstate, "IBM ThinkPad R40e", {
 150           DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
 151           DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
 152         { set_max_cstate, "Medion 41700", {
 153           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 154           DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
 155         { set_max_cstate, "Clevo 5600D", {
 156           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 157           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 158          (void *)2},
 159         {},
 160 };
 161
 162 static inline u32 ticks_elapsed(u32 t1, u32 t2)
 163 {
 164         if (t2 >= t1)
 165                 return (t2 - t1);
 166         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 167                 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 168         else
 169                 return ((0xFFFFFFFF - t1) + t2);
 170 }
 171
 172 static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
 173 {
 174         if (t2 >= t1)
 175                 return PM_TIMER_TICKS_TO_US(t2 - t1);
 176         else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
 177                 return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
 178         else
 179                 return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
 180 }
 181
 182 /*
 183  * Callers should disable interrupts before the call and enable
 184  * interrupts after return.
 185  */
 186 static void acpi_safe_halt(void)
 187 {
 188         current_thread_info()->status &= ~TS_POLLING;
 189         /*
 190          * TS_POLLING-cleared state must be visible before we
 191          * test NEED_RESCHED:
 192          */
 193         smp_mb();
 194         if (!need_resched()) {
 195                 safe_halt();
 196                 local_irq_disable();
 197         }
 198         current_thread_info()->status |= TS_POLLING;
 199 }
 200
 201 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 202
 203 /*
 204  * Some BIOS implementations switch to C3 in the published C2 state.
 205  * This seems to be a common problem on AMD boxen, but other vendors
 206  * are affected too. We pick the most conservative approach: we assume
 207  * that the local APIC stops in both C2 and C3.
 208  */
 209 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 210                                    struct acpi_processor_cx *cx)
 211 {
 212         struct acpi_processor_power *pwr = &pr->power;
 213         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 214
 215         /*
 216          * Check, if one of the previous states already marked the lapic
 217          * unstable
 218          */
 219         if (pwr->timer_broadcast_on_state < state)
 220                 return;
 221
 222         if (cx->type >= type)
 223                 pr->power.timer_broadcast_on_state = state;
 224 }
 225
 226 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
 227 {
 228         unsigned long reason;
 229
 230         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 231                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 232
 233         clockevents_notify(reason, &pr->id);
 234 }
 235
 236 /* Power(C) State timer broadcast control */
 237 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 238                                        struct acpi_processor_cx *cx,
 239                                        int broadcast)
 240 {
 241         int state = cx - pr->power.states;
 242
 243         if (state >= pr->power.timer_broadcast_on_state) {
 244                 unsigned long reason;
 245
 246                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 247                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 248                 clockevents_notify(reason, &pr->id);
 249         }
 250 }
 251
 252 #else
 253
 254 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 255                                    struct acpi_processor_cx *cstate) { }
 256 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
 257 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 258                                        struct acpi_processor_cx *cx,
 259                                        int broadcast)
 260 {
 261 }
 262
 263 #endif
 264
 265 /*
 266  * Suspend / resume control
 267  */
 268 static int acpi_idle_suspend;
 269
 270 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 271 {
 272         acpi_idle_suspend = 1;
 273         return 0;
 274 }
 275
 276 int acpi_processor_resume(struct acpi_device * device)
 277 {
 278         acpi_idle_suspend = 0;
 279         return 0;
 280 }
 281
 282 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 283 static int tsc_halts_in_c(int state)
 284 {
 285         switch (boot_cpu_data.x86_vendor) {
 286         case X86_VENDOR_AMD:
 287         case X86_VENDOR_INTEL:
 288                 /*
 289                  * AMD Fam10h TSC will tick in all
 290                  * C/P/S0/S1 states when this bit is set.
 291                  */
 292                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 293                         return 0;
 294
 295                 /*FALL THROUGH*/
 296         default:
 297                 return state > ACPI_STATE_C1;
 298         }
 299 }
 300 #endif
 301
 302 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 303 {
 304
 305         if (!pr)
 306                 return -EINVAL;
 307
 308         if (!pr->pblk)
 309                 return -ENODEV;
 310
 311         /* if info is obtained from pblk/fadt, type equals state */
 312         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 313         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 314
 315 #ifndef CONFIG_HOTPLUG_CPU
 316         /*
 317          * Check for P_LVL2_UP flag before entering C2 and above on
 318          * an SMP system.
 319          */
 320         if ((num_online_cpus() > 1) &&
 321             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 322                 return -ENODEV;
 323 #endif
 324
 325         /* determine C2 and C3 address from pblk */
 326         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 327         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 328
 329         /* determine latencies from FADT */
 330         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 331         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 332
 333         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 335                           pr->power.states[ACPI_STATE_C2].address,
 336                           pr->power.states[ACPI_STATE_C3].address));
 337
 338         return 0;
 339 }
 340
 341 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 342 {
 343         if (!pr->power.states[ACPI_STATE_C1].valid) {
 344                 /* set the first C-State to C1 */
 345                 /* all processors need to support C1 */
 346                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 347                 pr->power.states[ACPI_STATE_C1].valid = 1;
 348                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 349         }
 350         /* the C0 state only exists as a filler in our array */
 351         pr->power.states[ACPI_STATE_C0].valid = 1;
 352         return 0;
 353 }
 354
 355 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 356 {
 357         acpi_status status = 0;
 358         acpi_integer count;
 359         int current_count;
 360         int i;
 361         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 362         union acpi_object *cst;
 363
 364
 365         if (nocst)
 366                 return -ENODEV;
 367
 368         current_count = 0;
 369
 370         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 371         if (ACPI_FAILURE(status)) {
 372                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 373                 return -ENODEV;
 374         }
 375
 376         cst = buffer.pointer;
 377
 378         /* There must be at least 2 elements */
 379         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 380                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 381                 status = -EFAULT;
 382                 goto end;
 383         }
 384
 385         count = cst->package.elements[0].integer.value;
 386
 387         /* Validate number of power states. */
 388         if (count < 1 || count != cst->package.count - 1) {
 389                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 390                 status = -EFAULT;
 391                 goto end;
 392         }
 393
 394         /* Tell driver that at least _CST is supported. */
 395         pr->flags.has_cst = 1;
 396
 397         for (i = 1; i <= count; i++) {
 398                 union acpi_object *element;
 399                 union acpi_object *obj;
 400                 struct acpi_power_register *reg;
 401                 struct acpi_processor_cx cx;
 402
 403                 memset(&cx, 0, sizeof(cx));
 404
 405                 element = &(cst->package.elements[i]);
 406                 if (element->type != ACPI_TYPE_PACKAGE)
 407                         continue;
 408
 409                 if (element->package.count != 4)
 410                         continue;
 411
 412                 obj = &(element->package.elements[0]);
 413
 414                 if (obj->type != ACPI_TYPE_BUFFER)
 415                         continue;
 416
 417                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 418
 419                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 420                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 421                         continue;
 422
 423                 /* There should be an easy way to extract an integer... */
 424                 obj = &(element->package.elements[1]);
 425                 if (obj->type != ACPI_TYPE_INTEGER)
 426                         continue;
 427
 428                 cx.type = obj->integer.value;
 429                 /*
 430                  * Some buggy BIOSes won't list C1 in _CST -
 431                  * Let acpi_processor_get_power_info_default() handle them later
 432                  */
 433                 if (i == 1 && cx.type != ACPI_STATE_C1)
 434                         current_count++;
 435
 436                 cx.address = reg->address;
 437                 cx.index = current_count + 1;
 438
 439                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 440                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 441                         if (acpi_processor_ffh_cstate_probe
 442                                         (pr->id, &cx, reg) == 0) {
 443                                 cx.entry_method = ACPI_CSTATE_FFH;
 444                         } else if (cx.type == ACPI_STATE_C1) {
 445                                 /*
 446                                  * C1 is a special case where FIXED_HARDWARE
 447                                  * can be handled in non-MWAIT way as well.
 448                                  * In that case, save this _CST entry info.
 449                                  * Otherwise, ignore this info and continue.
 450                                  */
 451                                 cx.entry_method = ACPI_CSTATE_HALT;
 452                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 453                         } else {
 454                                 continue;
 455                         }
 456                         if (cx.type == ACPI_STATE_C1 &&
 457                                         (idle_halt || idle_nomwait)) {
 458                                 /*
 459                                  * In most cases the C1 space_id obtained from
 460                                  * _CST object is FIXED_HARDWARE access mode.
 461                                  * But when the option of idle=halt is added,
 462                                  * the entry_method type should be changed from
 463                                  * CSTATE_FFH to CSTATE_HALT.
 464                                  * When the option of idle=nomwait is added,
 465                                  * the C1 entry_method type should be
 466                                  * CSTATE_HALT.
 467                                  */
 468                                 cx.entry_method = ACPI_CSTATE_HALT;
 469                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 470                         }
 471                 } else {
 472                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 473                                  cx.address);
 474                 }
 475
 476                 if (cx.type == ACPI_STATE_C1) {
 477                         cx.valid = 1;
 478                 }
 479
 480                 obj = &(element->package.elements[2]);
 481                 if (obj->type != ACPI_TYPE_INTEGER)
 482                         continue;
 483
 484                 cx.latency = obj->integer.value;
 485
 486                 obj = &(element->package.elements[3]);
 487                 if (obj->type != ACPI_TYPE_INTEGER)
 488                         continue;
 489
 490                 cx.power = obj->integer.value;
 491
 492                 current_count++;
 493                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 494
 495                 /*
 496                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 497                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 498                  */
 499                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 500                         printk(KERN_WARNING
 501                                "Limiting number of power states to max (%d)\n",
 502                                ACPI_PROCESSOR_MAX_POWER);
 503                         printk(KERN_WARNING
 504                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 505                         break;
 506                 }
 507         }
 508
 509         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 510                           current_count));
 511
 512         /* Validate number of power states discovered */
 513         if (current_count < 2)
 514                 status = -EFAULT;
 515
 516       end:
 517         kfree(buffer.pointer);
 518
 519         return status;
 520 }
 521
 522 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 523 {
 524
 525         if (!cx->address)
 526                 return;
 527
 528         /*
 529          * C2 latency must be less than or equal to 100
 530          * microseconds.
 531          */
 532         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 533                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 534                                   "latency too large [%d]\n", cx->latency));
 535                 return;
 536         }
 537
 538         /*
 539          * Otherwise we've met all of our C2 requirements.
 540          * Normalize the C2 latency to expidite policy
 541          */
 542         cx->valid = 1;
 543
 544         cx->latency_ticks = cx->latency;
 545
 546         return;
 547 }
 548
 549 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 550                                            struct acpi_processor_cx *cx)
 551 {
 552         static int bm_check_flag;
 553
 554
 555         if (!cx->address)
 556                 return;
 557
 558         /*
 559          * C3 latency must be less than or equal to 1000
 560          * microseconds.
 561          */
 562         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 563                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 564                                   "latency too large [%d]\n", cx->latency));
 565                 return;
 566         }
 567
 568         /*
 569          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 570          * DMA transfers are used by any ISA device to avoid livelock.
 571          * Note that we could disable Type-F DMA (as recommended by
 572          * the erratum), but this is known to disrupt certain ISA
 573          * devices thus we take the conservative approach.
 574          */
 575         else if (errata.piix4.fdma) {
 576                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 577                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 578                 return;
 579         }
 580
 581         /* All the logic here assumes flags.bm_check is same across all CPUs */
 582         if (!bm_check_flag) {
 583                 /* Determine whether bm_check is needed based on CPU  */
 584                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 585                 bm_check_flag = pr->flags.bm_check;
 586         } else {
 587                 pr->flags.bm_check = bm_check_flag;
 588         }
 589
 590         if (pr->flags.bm_check) {
 591                 if (!pr->flags.bm_control) {
 592                         if (pr->flags.has_cst != 1) {
 593                                 /* bus mastering control is necessary */
 594                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 595                                         "C3 support requires BM control\n"));
 596                                 return;
 597                         } else {
 598                                 /* Here we enter C3 without bus mastering */
 599                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 600                                         "C3 support without BM control\n"));
 601                         }
 602                 }
 603         } else {
 604                 /*
 605                  * WBINVD should be set in fadt, for C3 state to be
 606                  * supported on when bm_check is not required.
 607                  */
 608                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 609                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 610                                           "Cache invalidation should work properly"
 611                                           " for C3 to be enabled on SMP systems\n"));
 612                         return;
 613                 }
 614         }
 615
 616         /*
 617          * Otherwise we've met all of our C3 requirements.
 618          * Normalize the C3 latency to expidite policy.  Enable
 619          * checking of bus mastering status (bm_check) so we can
 620          * use this in our C3 policy
 621          */
 622         cx->valid = 1;
 623
 624         cx->latency_ticks = cx->latency;
 625         /*
 626          * On older chipsets, BM_RLD needs to be set
 627          * in order for Bus Master activity to wake the
 628          * system from C3.  Newer chipsets handle DMA
 629          * during C3 automatically and BM_RLD is a NOP.
 630          * In either case, the proper way to
 631          * handle BM_RLD is to set it and leave it set.
 632          */
 633         acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 634
 635         return;
 636 }
 637
 638 static int acpi_processor_power_verify(struct acpi_processor *pr)
 639 {
 640         unsigned int i;
 641         unsigned int working = 0;
 642
 643         pr->power.timer_broadcast_on_state = INT_MAX;
 644
 645         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 646                 struct acpi_processor_cx *cx = &pr->power.states[i];
 647
 648                 switch (cx->type) {
 649                 case ACPI_STATE_C1:
 650                         cx->valid = 1;
 651                         break;
 652
 653                 case ACPI_STATE_C2:
 654                         acpi_processor_power_verify_c2(cx);
 655                         if (cx->valid)
 656                                 acpi_timer_check_state(i, pr, cx);
 657                         break;
 658
 659                 case ACPI_STATE_C3:
 660                         acpi_processor_power_verify_c3(pr, cx);
 661                         if (cx->valid)
 662                                 acpi_timer_check_state(i, pr, cx);
 663                         break;
 664                 }
 665
 666                 if (cx->valid)
 667                         working++;
 668         }
 669
 670         acpi_propagate_timer_broadcast(pr);
 671
 672         return (working);
 673 }
 674
 675 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 676 {
 677         unsigned int i;
 678         int result;
 679
 680
 681         /* NOTE: the idle thread may not be running while calling
 682          * this function */
 683
 684         /* Zero initialize all the C-states info. */
 685         memset(pr->power.states, 0, sizeof(pr->power.states));
 686
 687         result = acpi_processor_get_power_info_cst(pr);
 688         if (result == -ENODEV)
 689                 result = acpi_processor_get_power_info_fadt(pr);
 690
 691         if (result)
 692                 return result;
 693
 694         acpi_processor_get_power_info_default(pr);
 695
 696         pr->power.count = acpi_processor_power_verify(pr);
 697
 698         /*
 699          * if one state of type C2 or C3 is available, mark this
 700          * CPU as being "idle manageable"
 701          */
 702         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 703                 if (pr->power.states[i].valid) {
 704                         pr->power.count = i;
 705                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 706                                 pr->flags.power = 1;
 707                 }
 708         }
 709
 710         return 0;
 711 }
 712
 713 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 714 {
 715         struct acpi_processor *pr = seq->private;
 716         unsigned int i;
 717
 718
 719         if (!pr)
 720                 goto end;
 721
 722         seq_printf(seq, "active state:            C%zd\n"
 723                    "max_cstate:              C%d\n"
 724                    "bus master activity:     %08x\n"
 725                    "maximum allowed latency: %d usec\n",
 726                    pr->power.state ? pr->power.state - pr->power.states : 0,
 727                    max_cstate, (unsigned)pr->power.bm_activity,
 728                    pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
 729
 730         seq_puts(seq, "states:\n");
 731
 732         for (i = 1; i <= pr->power.count; i++) {
 733                 seq_printf(seq, "   %cC%d:                  ",
 734                            (&pr->power.states[i] ==
 735                             pr->power.state ? '*' : ' '), i);
 736
 737                 if (!pr->power.states[i].valid) {
 738                         seq_puts(seq, "<not supported>\n");
 739                         continue;
 740                 }
 741
 742                 switch (pr->power.states[i].type) {
 743                 case ACPI_STATE_C1:
 744                         seq_printf(seq, "type[C1] ");
 745                         break;
 746                 case ACPI_STATE_C2:
 747                         seq_printf(seq, "type[C2] ");
 748                         break;
 749                 case ACPI_STATE_C3:
 750                         seq_printf(seq, "type[C3] ");
 751                         break;
 752                 default:
 753                         seq_printf(seq, "type[--] ");
 754                         break;
 755                 }
 756
 757                 if (pr->power.states[i].promotion.state)
 758                         seq_printf(seq, "promotion[C%zd] ",
 759                                    (pr->power.states[i].promotion.state -
 760                                     pr->power.states));
 761                 else
 762                         seq_puts(seq, "promotion[--] ");
 763
 764                 if (pr->power.states[i].demotion.state)
 765                         seq_printf(seq, "demotion[C%zd] ",
 766                                    (pr->power.states[i].demotion.state -
 767                                     pr->power.states));
 768                 else
 769                         seq_puts(seq, "demotion[--] ");
 770
 771                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
 772                            pr->power.states[i].latency,
 773                            pr->power.states[i].usage,
 774                            (unsigned long long)pr->power.states[i].time);
 775         }
 776
 777       end:
 778         return 0;
 779 }
 780
 781 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 782 {
 783         return single_open(file, acpi_processor_power_seq_show,
 784                            PDE(inode)->data);
 785 }
 786
 787 static const struct file_operations acpi_processor_power_fops = {
 788         .owner = THIS_MODULE,
 789         .open = acpi_processor_power_open_fs,
 790         .read = seq_read,
 791         .llseek = seq_lseek,
 792         .release = single_release,
 793 };
 794
 795
 796 /**
 797  * acpi_idle_bm_check - checks if bus master activity was detected
 798  */
 799 static int acpi_idle_bm_check(void)
 800 {
 801         u32 bm_status = 0;
 802
 803         acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 804         if (bm_status)
 805                 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 806         /*
 807          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 808          * the true state of bus mastering activity; forcing us to
 809          * manually check the BMIDEA bit of each IDE channel.
 810          */
 811         else if (errata.piix4.bmisx) {
 812                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 813                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 814                         bm_status = 1;
 815         }
 816         return bm_status;
 817 }
 818
 819 /**
 820  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 821  * @cx: cstate data
 822  *
 823  * Caller disables interrupt before call and enables interrupt after return.
 824  */
 825 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 826 {
 827         /* Don't trace irqs off for idle */
 828         stop_critical_timings();
 829         if (cx->entry_method == ACPI_CSTATE_FFH) {
 830                 /* Call into architectural FFH based C-state */
 831                 acpi_processor_ffh_cstate_enter(cx);
 832         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 833                 acpi_safe_halt();
 834         } else {
 835                 int unused;
 836                 /* IO port based C-state */
 837                 inb(cx->address);
 838                 /* Dummy wait op - must do something useless after P_LVL2 read
 839                    because chipsets cannot guarantee that STPCLK# signal
 840                    gets asserted in time to freeze execution properly. */
 841                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 842         }
 843         start_critical_timings();
 844 }
 845
 846 /**
 847  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 848  * @dev: the target CPU
 849  * @state: the state data
 850  *
 851  * This is equivalent to the HALT instruction.
 852  */
 853 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 854                               struct cpuidle_state *state)
 855 {
 856         u32 t1, t2;
 857         struct acpi_processor *pr;
 858         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 859
 860         pr = __get_cpu_var(processors);
 861
 862         if (unlikely(!pr))
 863                 return 0;
 864
 865         local_irq_disable();
 866
 867         /* Do not access any ACPI IO ports in suspend path */
 868         if (acpi_idle_suspend) {
 869                 acpi_safe_halt();
 870                 local_irq_enable();
 871                 return 0;
 872         }
 873
 874         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 875         acpi_idle_do_entry(cx);
 876         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 877
 878         local_irq_enable();
 879         cx->usage++;
 880
 881         return ticks_elapsed_in_us(t1, t2);
 882 }
 883
 884 /**
 885  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 886  * @dev: the target CPU
 887  * @state: the state data
 888  */
 889 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 890                                   struct cpuidle_state *state)
 891 {
 892         struct acpi_processor *pr;
 893         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 894         u32 t1, t2;
 895         int sleep_ticks = 0;
 896
 897         pr = __get_cpu_var(processors);
 898
 899         if (unlikely(!pr))
 900                 return 0;
 901
 902         if (acpi_idle_suspend)
 903                 return(acpi_idle_enter_c1(dev, state));
 904
 905         local_irq_disable();
 906         current_thread_info()->status &= ~TS_POLLING;
 907         /*
 908          * TS_POLLING-cleared state must be visible before we test
 909          * NEED_RESCHED:
 910          */
 911         smp_mb();
 912
 913         if (unlikely(need_resched())) {
 914                 current_thread_info()->status |= TS_POLLING;
 915                 local_irq_enable();
 916                 return 0;
 917         }
 918
 919         /*
 920          * Must be done before busmaster disable as we might need to
 921          * access HPET !
 922          */
 923         acpi_state_timer_broadcast(pr, cx, 1);
 924
 925         if (cx->type == ACPI_STATE_C3)
 926                 ACPI_FLUSH_CPU_CACHE();
 927
 928         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 929         /* Tell the scheduler that we are going deep-idle: */
 930         sched_clock_idle_sleep_event();
 931         acpi_idle_do_entry(cx);
 932         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
 933
 934 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 935         /* TSC could halt in idle, so notify users */
 936         if (tsc_halts_in_c(cx->type))
 937                 mark_tsc_unstable("TSC halts in idle");;
 938 #endif
 939         sleep_ticks = ticks_elapsed(t1, t2);
 940
 941         /* Tell the scheduler how much we idled: */
 942         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 943
 944         local_irq_enable();
 945         current_thread_info()->status |= TS_POLLING;
 946
 947         cx->usage++;
 948
 949         acpi_state_timer_broadcast(pr, cx, 0);
 950         cx->time += sleep_ticks;
 951         return ticks_elapsed_in_us(t1, t2);
 952 }
 953
 954 static int c3_cpu_count;
 955 static DEFINE_SPINLOCK(c3_lock);
 956
 957 /**
 958  * acpi_idle_enter_bm - enters C3 with proper BM handling
 959  * @dev: the target CPU
 960  * @state: the state data
 961  *
 962  * If BM is detected, the deepest non-C3 idle state is entered instead.
 963  */
 964 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 965                               struct cpuidle_state *state)
 966 {
 967         struct acpi_processor *pr;
 968         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 969         u32 t1, t2;
 970         int sleep_ticks = 0;
 971
 972         pr = __get_cpu_var(processors);
 973
 974         if (unlikely(!pr))
 975                 return 0;
 976
 977         if (acpi_idle_suspend)
 978                 return(acpi_idle_enter_c1(dev, state));
 979
 980         if (acpi_idle_bm_check()) {
 981                 if (dev->safe_state) {
 982                         dev->last_state = dev->safe_state;
 983                         return dev->safe_state->enter(dev, dev->safe_state);
 984                 } else {
 985                         local_irq_disable();
 986                         acpi_safe_halt();
 987                         local_irq_enable();
 988                         return 0;
 989                 }
 990         }
 991
 992         local_irq_disable();
 993         current_thread_info()->status &= ~TS_POLLING;
 994         /*
 995          * TS_POLLING-cleared state must be visible before we test
 996          * NEED_RESCHED:
 997          */
 998         smp_mb();
 999
1000         if (unlikely(need_resched())) {
1001                 current_thread_info()->status |= TS_POLLING;
1002                 local_irq_enable();
1003                 return 0;
1004         }
1005
1006         acpi_unlazy_tlb(smp_processor_id());
1007
1008         /* Tell the scheduler that we are going deep-idle: */
1009         sched_clock_idle_sleep_event();
1010         /*
1011          * Must be done before busmaster disable as we might need to
1012          * access HPET !
1013          */
1014         acpi_state_timer_broadcast(pr, cx, 1);
1015
1016         /*
1017          * disable bus master
1018          * bm_check implies we need ARB_DIS
1019          * !bm_check implies we need cache flush
1020          * bm_control implies whether we can do ARB_DIS
1021          *
1022          * That leaves a case where bm_check is set and bm_control is
1023          * not set. In that case we cannot do much, we enter C3
1024          * without doing anything.
1025          */
1026         if (pr->flags.bm_check && pr->flags.bm_control) {
1027                 spin_lock(&c3_lock);
1028                 c3_cpu_count++;
1029                 /* Disable bus master arbitration when all CPUs are in C3 */
1030                 if (c3_cpu_count == num_online_cpus())
1031                         acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
1032                 spin_unlock(&c3_lock);
1033         } else if (!pr->flags.bm_check) {
1034                 ACPI_FLUSH_CPU_CACHE();
1035         }
1036
1037         t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1038         acpi_idle_do_entry(cx);
1039         t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
1040
1041         /* Re-enable bus master arbitration */
1042         if (pr->flags.bm_check && pr->flags.bm_control) {
1043                 spin_lock(&c3_lock);
1044                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
1045                 c3_cpu_count--;
1046                 spin_unlock(&c3_lock);
1047         }
1048
1049 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
1050         /* TSC could halt in idle, so notify users */
1051         if (tsc_halts_in_c(ACPI_STATE_C3))
1052                 mark_tsc_unstable("TSC halts in idle");
1053 #endif
1054         sleep_ticks = ticks_elapsed(t1, t2);
1055         /* Tell the scheduler how much we idled: */
1056         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1057
1058         local_irq_enable();
1059         current_thread_info()->status |= TS_POLLING;
1060
1061         cx->usage++;
1062
1063         acpi_state_timer_broadcast(pr, cx, 0);
1064         cx->time += sleep_ticks;
1065         return ticks_elapsed_in_us(t1, t2);
1066 }
1067
1068 struct cpuidle_driver acpi_idle_driver = {
1069         .name =         "acpi_idle",
1070         .owner =        THIS_MODULE,
1071 };
1072
1073 /**
1074  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1075  * @pr: the ACPI processor
1076  */
1077 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1078 {
1079         int i, count = CPUIDLE_DRIVER_STATE_START;
1080         struct acpi_processor_cx *cx;
1081         struct cpuidle_state *state;
1082         struct cpuidle_device *dev = &pr->power.dev;
1083
1084         if (!pr->flags.power_setup_done)
1085                 return -EINVAL;
1086
1087         if (pr->flags.power == 0) {
1088                 return -EINVAL;
1089         }
1090
1091         dev->cpu = pr->id;
1092         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1093                 dev->states[i].name[0] = '\0';
1094                 dev->states[i].desc[0] = '\0';
1095         }
1096
1097         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1098                 cx = &pr->power.states[i];
1099                 state = &dev->states[count];
1100
1101                 if (!cx->valid)
1102                         continue;
1103
1104 #ifdef CONFIG_HOTPLUG_CPU
1105                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1106                     !pr->flags.has_cst &&
1107                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1108                         continue;
1109 #endif
1110                 cpuidle_set_statedata(state, cx);
1111
1112                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1113                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1114                 state->exit_latency = cx->latency;
1115                 state->target_residency = cx->latency * latency_factor;
1116                 state->power_usage = cx->power;
1117
1118                 state->flags = 0;
1119                 switch (cx->type) {
1120                         case ACPI_STATE_C1:
1121                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1122                         if (cx->entry_method == ACPI_CSTATE_FFH)
1123                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1124
1125                         state->enter = acpi_idle_enter_c1;
1126                         dev->safe_state = state;
1127                         break;
1128
1129                         case ACPI_STATE_C2:
1130                         state->flags |= CPUIDLE_FLAG_BALANCED;
1131                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1132                         state->enter = acpi_idle_enter_simple;
1133                         dev->safe_state = state;
1134                         break;
1135
1136                         case ACPI_STATE_C3:
1137                         state->flags |= CPUIDLE_FLAG_DEEP;
1138                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1139                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1140                         state->enter = pr->flags.bm_check ?
1141                                         acpi_idle_enter_bm :
1142                                         acpi_idle_enter_simple;
1143                         break;
1144                 }
1145
1146                 count++;
1147                 if (count == CPUIDLE_STATE_MAX)
1148                         break;
1149         }
1150
1151         dev->state_count = count;
1152
1153         if (!count)
1154                 return -EINVAL;
1155
1156         return 0;
1157 }
1158
1159 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1160 {
1161         int ret = 0;
1162
1163         if (boot_option_idle_override)
1164                 return 0;
1165
1166         if (!pr)
1167                 return -EINVAL;
1168
1169         if (nocst) {
1170                 return -ENODEV;
1171         }
1172
1173         if (!pr->flags.power_setup_done)
1174                 return -ENODEV;
1175
1176         cpuidle_pause_and_lock();
1177         cpuidle_disable_device(&pr->power.dev);
1178         acpi_processor_get_power_info(pr);
1179         if (pr->flags.power) {
1180                 acpi_processor_setup_cpuidle(pr);
1181                 ret = cpuidle_enable_device(&pr->power.dev);
1182         }
1183         cpuidle_resume_and_unlock();
1184
1185         return ret;
1186 }
1187
1188 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1189                               struct acpi_device *device)
1190 {
1191         acpi_status status = 0;
1192         static int first_run;
1193         struct proc_dir_entry *entry = NULL;
1194         unsigned int i;
1195
1196         if (boot_option_idle_override)
1197                 return 0;
1198
1199         if (!first_run) {
1200                 if (idle_halt) {
1201                         /*
1202                          * When the boot option of "idle=halt" is added, halt
1203                          * is used for CPU IDLE.
1204                          * In such case C2/C3 is meaningless. So the max_cstate
1205                          * is set to one.
1206                          */
1207                         max_cstate = 1;
1208                 }
1209                 dmi_check_system(processor_power_dmi_table);
1210                 max_cstate = acpi_processor_cstate_check(max_cstate);
1211                 if (max_cstate < ACPI_C_STATES_MAX)
1212                         printk(KERN_NOTICE
1213                                "ACPI: processor limited to max C-state %d\n",
1214                                max_cstate);
1215                 first_run++;
1216         }
1217
1218         if (!pr)
1219                 return -EINVAL;
1220
1221         if (acpi_gbl_FADT.cst_control && !nocst) {
1222                 status =
1223                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1224                 if (ACPI_FAILURE(status)) {
1225                         ACPI_EXCEPTION((AE_INFO, status,
1226                                         "Notifying BIOS of _CST ability failed"));
1227                 }
1228         }
1229
1230         acpi_processor_get_power_info(pr);
1231         pr->flags.power_setup_done = 1;
1232
1233         /*
1234          * Install the idle handler if processor power management is supported.
1235          * Note that we use previously set idle handler will be used on
1236          * platforms that only support C1.
1237          */
1238         if (pr->flags.power) {
1239                 acpi_processor_setup_cpuidle(pr);
1240                 if (cpuidle_register_device(&pr->power.dev))
1241                         return -EIO;
1242
1243                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1244                 for (i = 1; i <= pr->power.count; i++)
1245                         if (pr->power.states[i].valid)
1246                                 printk(" C%d[C%d]", i,
1247                                        pr->power.states[i].type);
1248                 printk(")\n");
1249         }
1250
1251         /* 'power' [R] */
1252         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1253                                  S_IRUGO, acpi_device_dir(device),
1254                                  &acpi_processor_power_fops,
1255                                  acpi_driver_data(device));
1256         if (!entry)
1257                 return -EIO;
1258         return 0;
1259 }
1260
1261 int acpi_processor_power_exit(struct acpi_processor *pr,
1262                               struct acpi_device *device)
1263 {
1264         if (boot_option_idle_override)
1265                 return 0;
1266
1267         cpuidle_unregister_device(&pr->power.dev);
1268         pr->flags.power_setup_done = 0;
1269
1270         if (acpi_device_dir(device))
1271                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1272                                   acpi_device_dir(device));
1273
1274         return 0;
1275 }