drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/slab.h>
  36 #include <linux/acpi.h>
  37 #include <linux/dmi.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/sched.h>        /* need_resched() */
  40 #include <linux/pm_qos.h>
  41 #include <linux/clockchips.h>
  42 #include <linux/cpuidle.h>
  43 #include <linux/irqflags.h>
  44
  45 /*
  46  * Include the apic definitions for x86 to have the APIC timer related defines
  47  * available also for UP (on SMP it gets magically included via linux/smp.h).
  48  * asm/acpi.h is not an option, as it would require more include magic. Also
  49  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  50  */
  51 #ifdef CONFIG_X86
  52 #include <asm/apic.h>
  53 #endif
  54
  55 #include <asm/io.h>
  56 #include <asm/uaccess.h>
  57
  58 #include <acpi/acpi_bus.h>
  59 #include <acpi/processor.h>
  60 #include <asm/processor.h>
  61
  62 #define PREFIX "ACPI: "
  63
  64 #define ACPI_PROCESSOR_CLASS            "processor"
  65 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  66 ACPI_MODULE_NAME("processor_idle");
  67 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  68 #define C2_OVERHEAD                     1       /* 1us */
  69 #define C3_OVERHEAD                     1       /* 1us */
  70 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  71
  72 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  73 module_param(max_cstate, uint, 0000);
  74 static unsigned int nocst __read_mostly;
  75 module_param(nocst, uint, 0000);
  76 static int bm_check_disable __read_mostly;
  77 module_param(bm_check_disable, uint, 0000);
  78
  79 static unsigned int latency_factor __read_mostly = 2;
  80 module_param(latency_factor, uint, 0644);
  81
  82 static int disabled_by_idle_boot_param(void)
  83 {
  84         return boot_option_idle_override == IDLE_POLL ||
  85                 boot_option_idle_override == IDLE_FORCE_MWAIT ||
  86                 boot_option_idle_override == IDLE_HALT;
  87 }
  88
  89 /*
  90  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  91  * For now disable this. Probably a bug somewhere else.
  92  *
  93  * To skip this limit, boot/load with a large max_cstate limit.
  94  */
  95 static int set_max_cstate(const struct dmi_system_id *id)
  96 {
  97         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  98                 return 0;
  99
 100         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
 101                " Override with \"processor.max_cstate=%d\"\n", id->ident,
 102                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 103
 104         max_cstate = (long)id->driver_data;
 105
 106         return 0;
 107 }
 108
 109 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 110    callers to only run once -AK */
 111 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 112         { set_max_cstate, "Clevo 5600D", {
 113           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 114           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 115          (void *)2},
 116         { set_max_cstate, "Pavilion zv5000", {
 117           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 118           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 119          (void *)1},
 120         { set_max_cstate, "Asus L8400B", {
 121           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 122           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 123          (void *)1},
 124         {},
 125 };
 126
 127
 128 #ifndef CONFIG_PROCESSOR_EXTERNAL_CONTROL
 129 /*
 130  * Callers should disable interrupts before the call and enable
 131  * interrupts after return.
 132  */
 133 static void acpi_safe_halt(void)
 134 {
 135         current_thread_info()->status &= ~TS_POLLING;
 136         /*
 137          * TS_POLLING-cleared state must be visible before we
 138          * test NEED_RESCHED:
 139          */
 140         smp_mb();
 141         if (!need_resched()) {
 142                 safe_halt();
 143                 local_irq_disable();
 144         }
 145         current_thread_info()->status |= TS_POLLING;
 146 }
 147 #endif
 148
 149 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 150
 151 /*
 152  * Some BIOS implementations switch to C3 in the published C2 state.
 153  * This seems to be a common problem on AMD boxen, but other vendors
 154  * are affected too. We pick the most conservative approach: we assume
 155  * that the local APIC stops in both C2 and C3.
 156  */
 157 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 158                                    struct acpi_processor_cx *cx)
 159 {
 160         struct acpi_processor_power *pwr = &pr->power;
 161         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 162
 163         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 164                 return;
 165
 166         if (amd_e400_c1e_detected)
 167                 type = ACPI_STATE_C1;
 168
 169         /*
 170          * Check, if one of the previous states already marked the lapic
 171          * unstable
 172          */
 173         if (pwr->timer_broadcast_on_state < state)
 174                 return;
 175
 176         if (cx->type >= type)
 177                 pr->power.timer_broadcast_on_state = state;
 178 }
 179
 180 static void __lapic_timer_propagate_broadcast(void *arg)
 181 {
 182         struct acpi_processor *pr = (struct acpi_processor *) arg;
 183         unsigned long reason;
 184
 185         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 186                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 187
 188         clockevents_notify(reason, &pr->id);
 189 }
 190
 191 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 192 {
 193         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 194                                  (void *)pr, 1);
 195 }
 196
 197 /* Power(C) State timer broadcast control */
 198 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 199                                        struct acpi_processor_cx *cx,
 200                                        int broadcast)
 201 {
 202         int state = cx - pr->power.states;
 203
 204         if (state >= pr->power.timer_broadcast_on_state) {
 205                 unsigned long reason;
 206
 207                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 208                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 209                 clockevents_notify(reason, &pr->id);
 210         }
 211 }
 212
 213 #else
 214
 215 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 216                                    struct acpi_processor_cx *cstate) { }
 217 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 218 static inline void lapic_timer_state_broadcast(struct acpi_processor *pr,
 219                                        struct acpi_processor_cx *cx,
 220                                        int broadcast)
 221 {
 222 }
 223
 224 #endif
 225
 226 /*
 227  * Suspend / resume control
 228  */
 229 static u32 saved_bm_rld;
 230
 231 static void acpi_idle_bm_rld_save(void)
 232 {
 233         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 234 }
 235 static void acpi_idle_bm_rld_restore(void)
 236 {
 237         u32 resumed_bm_rld;
 238
 239         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 240
 241         if (resumed_bm_rld != saved_bm_rld)
 242                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 243 }
 244
 245 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 246 {
 247         acpi_idle_bm_rld_save();
 248         return 0;
 249 }
 250
 251 int acpi_processor_resume(struct acpi_device * device)
 252 {
 253         acpi_idle_bm_rld_restore();
 254         return 0;
 255 }
 256
 257 #if defined(CONFIG_X86) && !defined(CONFIG_PROCESSOR_EXTERNAL_CONTROL)
 258 static void tsc_check_state(int state)
 259 {
 260         switch (boot_cpu_data.x86_vendor) {
 261         case X86_VENDOR_AMD:
 262         case X86_VENDOR_INTEL:
 263                 /*
 264                  * AMD Fam10h TSC will tick in all
 265                  * C/P/S0/S1 states when this bit is set.
 266                  */
 267                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 268                         return;
 269
 270                 /*FALL THROUGH*/
 271         default:
 272                 /* TSC could halt in idle, so notify users */
 273                 if (state > ACPI_STATE_C1)
 274                         mark_tsc_unstable("TSC halts in idle");
 275         }
 276 }
 277 #else
 278 static void tsc_check_state(int state) { return; }
 279 #endif
 280
 281 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 282 {
 283
 284         if (!pr)
 285                 return -EINVAL;
 286
 287         if (!pr->pblk)
 288                 return -ENODEV;
 289
 290         /* if info is obtained from pblk/fadt, type equals state */
 291         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 292         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 293
 294 #ifndef CONFIG_HOTPLUG_CPU
 295         /*
 296          * Check for P_LVL2_UP flag before entering C2 and above on
 297          * an SMP system.
 298          */
 299         if ((num_online_cpus() > 1) &&
 300             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 301                 return -ENODEV;
 302 #endif
 303
 304         /* determine C2 and C3 address from pblk */
 305         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 306         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 307
 308         /* determine latencies from FADT */
 309         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 310         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 311
 312         /*
 313          * FADT specified C2 latency must be less than or equal to
 314          * 100 microseconds.
 315          */
 316         if (acpi_gbl_FADT.C2latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 317                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 318                         "C2 latency too large [%d]\n", acpi_gbl_FADT.C2latency));
 319                 /* invalidate C2 */
 320                 pr->power.states[ACPI_STATE_C2].address = 0;
 321         }
 322
 323         /*
 324          * FADT supplied C3 latency must be less than or equal to
 325          * 1000 microseconds.
 326          */
 327         if (acpi_gbl_FADT.C3latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 329                         "C3 latency too large [%d]\n", acpi_gbl_FADT.C3latency));
 330                 /* invalidate C3 */
 331                 pr->power.states[ACPI_STATE_C3].address = 0;
 332         }
 333
 334         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 335                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 336                           pr->power.states[ACPI_STATE_C2].address,
 337                           pr->power.states[ACPI_STATE_C3].address));
 338
 339         return 0;
 340 }
 341
 342 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 343 {
 344         if (!pr->power.states[ACPI_STATE_C1].valid) {
 345                 /* set the first C-State to C1 */
 346                 /* all processors need to support C1 */
 347                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 348                 pr->power.states[ACPI_STATE_C1].valid = 1;
 349                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 350         }
 351         /* the C0 state only exists as a filler in our array */
 352         pr->power.states[ACPI_STATE_C0].valid = 1;
 353         return 0;
 354 }
 355
 356 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 357 {
 358         acpi_status status = 0;
 359         u64 count;
 360         int current_count;
 361         int i;
 362         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 363         union acpi_object *cst;
 364
 365
 366         if (nocst)
 367                 return -ENODEV;
 368
 369         current_count = 0;
 370
 371         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 372         if (ACPI_FAILURE(status)) {
 373                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 374                 return -ENODEV;
 375         }
 376
 377         cst = buffer.pointer;
 378
 379         /* There must be at least 2 elements */
 380         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 381                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 382                 status = -EFAULT;
 383                 goto end;
 384         }
 385
 386         count = cst->package.elements[0].integer.value;
 387
 388         /* Validate number of power states. */
 389         if (count < 1 || count != cst->package.count - 1) {
 390                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 391                 status = -EFAULT;
 392                 goto end;
 393         }
 394
 395         /* Tell driver that at least _CST is supported. */
 396         pr->flags.has_cst = 1;
 397
 398         for (i = 1; i <= count; i++) {
 399                 union acpi_object *element;
 400                 union acpi_object *obj;
 401                 struct acpi_power_register *reg;
 402                 struct acpi_processor_cx cx;
 403
 404                 memset(&cx, 0, sizeof(cx));
 405
 406                 element = &(cst->package.elements[i]);
 407                 if (element->type != ACPI_TYPE_PACKAGE)
 408                         continue;
 409
 410                 if (element->package.count != 4)
 411                         continue;
 412
 413                 obj = &(element->package.elements[0]);
 414
 415                 if (obj->type != ACPI_TYPE_BUFFER)
 416                         continue;
 417
 418                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 419
 420                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 421                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 422                         continue;
 423
 424                 /* There should be an easy way to extract an integer... */
 425                 obj = &(element->package.elements[1]);
 426                 if (obj->type != ACPI_TYPE_INTEGER)
 427                         continue;
 428
 429                 cx.type = obj->integer.value;
 430                 /*
 431                  * Some buggy BIOSes won't list C1 in _CST -
 432                  * Let acpi_processor_get_power_info_default() handle them later
 433                  */
 434                 if (i == 1 && cx.type != ACPI_STATE_C1)
 435                         current_count++;
 436
 437                 cx.address = reg->address;
 438                 cx.index = current_count + 1;
 439
 440                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 441                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 442                         if (acpi_processor_ffh_cstate_probe
 443                                         (pr->id, &cx, reg) == 0) {
 444                                 cx.entry_method = ACPI_CSTATE_FFH;
 445                         } else if (cx.type == ACPI_STATE_C1) {
 446                                 /*
 447                                  * C1 is a special case where FIXED_HARDWARE
 448                                  * can be handled in non-MWAIT way as well.
 449                                  * In that case, save this _CST entry info.
 450                                  * Otherwise, ignore this info and continue.
 451                                  */
 452                                 cx.entry_method = ACPI_CSTATE_HALT;
 453                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 454                         /* This doesn't apply to external control case */
 455                         } else if (!processor_pm_external()) {
 456                                 continue;
 457                         }
 458                         if (cx.type == ACPI_STATE_C1 &&
 459                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 460                                 /*
 461                                  * In most cases the C1 space_id obtained from
 462                                  * _CST object is FIXED_HARDWARE access mode.
 463                                  * But when the option of idle=halt is added,
 464                                  * the entry_method type should be changed from
 465                                  * CSTATE_FFH to CSTATE_HALT.
 466                                  * When the option of idle=nomwait is added,
 467                                  * the C1 entry_method type should be
 468                                  * CSTATE_HALT.
 469                                  */
 470                                 cx.entry_method = ACPI_CSTATE_HALT;
 471                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 472                         }
 473                 } else {
 474                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 475                                  cx.address);
 476                 }
 477
 478                 if (cx.type == ACPI_STATE_C1) {
 479                         cx.valid = 1;
 480                 }
 481
 482                 obj = &(element->package.elements[2]);
 483                 if (obj->type != ACPI_TYPE_INTEGER)
 484                         continue;
 485
 486                 cx.latency = obj->integer.value;
 487
 488                 obj = &(element->package.elements[3]);
 489                 if (obj->type != ACPI_TYPE_INTEGER)
 490                         continue;
 491
 492                 cx.power = obj->integer.value;
 493
 494 #ifdef CONFIG_PROCESSOR_EXTERNAL_CONTROL
 495                 /* cache control methods to notify external logic */
 496                 if (processor_pm_external())
 497                         memcpy(&cx.reg, reg, sizeof(*reg));
 498 #endif
 499
 500                 current_count++;
 501                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 502
 503                 /*
 504                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 505                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 506                  */
 507                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 508                         printk(KERN_WARNING
 509                                "Limiting number of power states to max (%d)\n",
 510                                ACPI_PROCESSOR_MAX_POWER);
 511                         printk(KERN_WARNING
 512                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 513                         break;
 514                 }
 515         }
 516
 517         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 518                           current_count));
 519
 520         /* Validate number of power states discovered */
 521         if (current_count < (processor_pm_external() ? 1 : 2))
 522                 status = -EFAULT;
 523
 524       end:
 525         kfree(buffer.pointer);
 526
 527         return status;
 528 }
 529
 530 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 531                                            struct acpi_processor_cx *cx)
 532 {
 533         static int bm_check_flag = -1;
 534         static int bm_control_flag = -1;
 535
 536
 537         if (!cx->address)
 538                 return;
 539
 540         /*
 541          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 542          * DMA transfers are used by any ISA device to avoid livelock.
 543          * Note that we could disable Type-F DMA (as recommended by
 544          * the erratum), but this is known to disrupt certain ISA
 545          * devices thus we take the conservative approach.
 546          */
 547         else if (errata.piix4.fdma) {
 548                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 549                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 550                 return;
 551         }
 552
 553         /* All the logic here assumes flags.bm_check is same across all CPUs */
 554         if (bm_check_flag == -1) {
 555                 /* Determine whether bm_check is needed based on CPU  */
 556                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 557                 bm_check_flag = pr->flags.bm_check;
 558                 bm_control_flag = pr->flags.bm_control;
 559         } else {
 560                 pr->flags.bm_check = bm_check_flag;
 561                 pr->flags.bm_control = bm_control_flag;
 562         }
 563
 564         if (pr->flags.bm_check) {
 565                 if (!pr->flags.bm_control) {
 566                         if (pr->flags.has_cst != 1) {
 567                                 /* bus mastering control is necessary */
 568                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 569                                         "C3 support requires BM control\n"));
 570                                 return;
 571                         } else {
 572                                 /* Here we enter C3 without bus mastering */
 573                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 574                                         "C3 support without BM control\n"));
 575                         }
 576                 }
 577         } else {
 578                 /*
 579                  * WBINVD should be set in fadt, for C3 state to be
 580                  * supported on when bm_check is not required.
 581                  */
 582                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 583                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 584                                           "Cache invalidation should work properly"
 585                                           " for C3 to be enabled on SMP systems\n"));
 586                         return;
 587                 }
 588         }
 589
 590         /*
 591          * Otherwise we've met all of our C3 requirements.
 592          * Normalize the C3 latency to expidite policy.  Enable
 593          * checking of bus mastering status (bm_check) so we can
 594          * use this in our C3 policy
 595          */
 596         cx->valid = 1;
 597
 598         cx->latency_ticks = cx->latency;
 599         /*
 600          * On older chipsets, BM_RLD needs to be set
 601          * in order for Bus Master activity to wake the
 602          * system from C3.  Newer chipsets handle DMA
 603          * during C3 automatically and BM_RLD is a NOP.
 604          * In either case, the proper way to
 605          * handle BM_RLD is to set it and leave it set.
 606          */
 607         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 608
 609         return;
 610 }
 611
 612 static int acpi_processor_power_verify(struct acpi_processor *pr)
 613 {
 614         unsigned int i;
 615         unsigned int working = 0;
 616
 617 #ifndef CONFIG_PROCESSOR_EXTERNAL_CONTROL
 618         pr->power.timer_broadcast_on_state = INT_MAX;
 619 #endif
 620
 621         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 622                 struct acpi_processor_cx *cx = &pr->power.states[i];
 623
 624                 switch (cx->type) {
 625                 case ACPI_STATE_C1:
 626                         cx->valid = 1;
 627                         break;
 628
 629                 case ACPI_STATE_C2:
 630                         if (!cx->address)
 631                                 break;
 632                         cx->valid = 1;
 633                         cx->latency_ticks = cx->latency; /* Normalize latency */
 634                         break;
 635
 636                 case ACPI_STATE_C3:
 637                         acpi_processor_power_verify_c3(pr, cx);
 638                         break;
 639                 }
 640                 if (!cx->valid)
 641                         continue;
 642
 643                 lapic_timer_check_state(i, pr, cx);
 644                 tsc_check_state(cx->type);
 645                 working++;
 646         }
 647
 648         lapic_timer_propagate_broadcast(pr);
 649
 650         return (working);
 651 }
 652
 653 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 654 {
 655         unsigned int i;
 656         int result;
 657
 658
 659         /* NOTE: the idle thread may not be running while calling
 660          * this function */
 661
 662         /* Zero initialize all the C-states info. */
 663         memset(pr->power.states, 0, sizeof(pr->power.states));
 664
 665         result = acpi_processor_get_power_info_cst(pr);
 666         if (result == -ENODEV)
 667                 result = acpi_processor_get_power_info_fadt(pr);
 668
 669         if (result)
 670                 return result;
 671
 672         acpi_processor_get_power_info_default(pr);
 673
 674         pr->power.count = acpi_processor_power_verify(pr);
 675
 676         /*
 677          * if one state of type C2 or C3 is available, mark this
 678          * CPU as being "idle manageable"
 679          */
 680         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 681                 if (pr->power.states[i].valid) {
 682                         pr->power.count = i;
 683                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 684                                 pr->flags.power = 1;
 685                 }
 686         }
 687
 688         return 0;
 689 }
 690
 691 #ifndef CONFIG_PROCESSOR_EXTERNAL_CONTROL
 692 /**
 693  * acpi_idle_bm_check - checks if bus master activity was detected
 694  */
 695 static int acpi_idle_bm_check(void)
 696 {
 697         u32 bm_status = 0;
 698
 699         if (bm_check_disable)
 700                 return 0;
 701
 702         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 703         if (bm_status)
 704                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 705         /*
 706          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 707          * the true state of bus mastering activity; forcing us to
 708          * manually check the BMIDEA bit of each IDE channel.
 709          */
 710         else if (errata.piix4.bmisx) {
 711                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 712                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 713                         bm_status = 1;
 714         }
 715         return bm_status;
 716 }
 717
 718 /**
 719  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 720  * @cx: cstate data
 721  *
 722  * Caller disables interrupt before call and enables interrupt after return.
 723  */
 724 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 725 {
 726         /* Don't trace irqs off for idle */
 727         stop_critical_timings();
 728         if (cx->entry_method == ACPI_CSTATE_FFH) {
 729                 /* Call into architectural FFH based C-state */
 730                 acpi_processor_ffh_cstate_enter(cx);
 731         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 732                 acpi_safe_halt();
 733         } else {
 734                 /* IO port based C-state */
 735                 inb(cx->address);
 736                 /* Dummy wait op - must do something useless after P_LVL2 read
 737                    because chipsets cannot guarantee that STPCLK# signal
 738                    gets asserted in time to freeze execution properly. */
 739                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 740         }
 741         start_critical_timings();
 742 }
 743
 744 /**
 745  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 746  * @dev: the target CPU
 747  * @drv: cpuidle driver containing cpuidle state info
 748  * @index: index of target state
 749  *
 750  * This is equivalent to the HALT instruction.
 751  */
 752 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 753                 struct cpuidle_driver *drv, int index)
 754 {
 755         ktime_t  kt1, kt2;
 756         s64 idle_time;
 757         struct acpi_processor *pr;
 758         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 759         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 760
 761         pr = __this_cpu_read(processors);
 762         dev->last_residency = 0;
 763
 764         if (unlikely(!pr))
 765                 return -EINVAL;
 766
 767         local_irq_disable();
 768
 769         lapic_timer_state_broadcast(pr, cx, 1);
 770         kt1 = ktime_get_real();
 771         acpi_idle_do_entry(cx);
 772         kt2 = ktime_get_real();
 773         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 774
 775         /* Update device last_residency*/
 776         dev->last_residency = (int)idle_time;
 777
 778         local_irq_enable();
 779         cx->usage++;
 780         lapic_timer_state_broadcast(pr, cx, 0);
 781
 782         return index;
 783 }
 784
 785
 786 /**
 787  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 788  * @dev: the target CPU
 789  * @index: the index of suggested state
 790  */
 791 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 792 {
 793         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 794         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 795
 796         ACPI_FLUSH_CPU_CACHE();
 797
 798         while (1) {
 799
 800                 if (cx->entry_method == ACPI_CSTATE_HALT)
 801                         safe_halt();
 802                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 803                         inb(cx->address);
 804                         /* See comment in acpi_idle_do_entry() */
 805                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 806                 } else
 807                         return -ENODEV;
 808         }
 809
 810         /* Never reached */
 811         return 0;
 812 }
 813
 814 /**
 815  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 816  * @dev: the target CPU
 817  * @drv: cpuidle driver with cpuidle state information
 818  * @index: the index of suggested state
 819  */
 820 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 821                 struct cpuidle_driver *drv, int index)
 822 {
 823         struct acpi_processor *pr;
 824         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 825         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 826         ktime_t  kt1, kt2;
 827         s64 idle_time_ns;
 828         s64 idle_time;
 829
 830         pr = __this_cpu_read(processors);
 831         dev->last_residency = 0;
 832
 833         if (unlikely(!pr))
 834                 return -EINVAL;
 835
 836         local_irq_disable();
 837
 838         if (cx->entry_method != ACPI_CSTATE_FFH) {
 839                 current_thread_info()->status &= ~TS_POLLING;
 840                 /*
 841                  * TS_POLLING-cleared state must be visible before we test
 842                  * NEED_RESCHED:
 843                  */
 844                 smp_mb();
 845
 846                 if (unlikely(need_resched())) {
 847                         current_thread_info()->status |= TS_POLLING;
 848                         local_irq_enable();
 849                         return -EINVAL;
 850                 }
 851         }
 852
 853         /*
 854          * Must be done before busmaster disable as we might need to
 855          * access HPET !
 856          */
 857         lapic_timer_state_broadcast(pr, cx, 1);
 858
 859         if (cx->type == ACPI_STATE_C3)
 860                 ACPI_FLUSH_CPU_CACHE();
 861
 862         kt1 = ktime_get_real();
 863         /* Tell the scheduler that we are going deep-idle: */
 864         sched_clock_idle_sleep_event();
 865         acpi_idle_do_entry(cx);
 866         kt2 = ktime_get_real();
 867         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
 868         idle_time = idle_time_ns;
 869         do_div(idle_time, NSEC_PER_USEC);
 870
 871         /* Update device last_residency*/
 872         dev->last_residency = (int)idle_time;
 873
 874         /* Tell the scheduler how much we idled: */
 875         sched_clock_idle_wakeup_event(idle_time_ns);
 876
 877         local_irq_enable();
 878         if (cx->entry_method != ACPI_CSTATE_FFH)
 879                 current_thread_info()->status |= TS_POLLING;
 880
 881         cx->usage++;
 882
 883         lapic_timer_state_broadcast(pr, cx, 0);
 884         cx->time += idle_time;
 885         return index;
 886 }
 887
 888 static int c3_cpu_count;
 889 static DEFINE_RAW_SPINLOCK(c3_lock);
 890
 891 /**
 892  * acpi_idle_enter_bm - enters C3 with proper BM handling
 893  * @dev: the target CPU
 894  * @drv: cpuidle driver containing state data
 895  * @index: the index of suggested state
 896  *
 897  * If BM is detected, the deepest non-C3 idle state is entered instead.
 898  */
 899 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 900                 struct cpuidle_driver *drv, int index)
 901 {
 902         struct acpi_processor *pr;
 903         struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 904         struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 905         ktime_t  kt1, kt2;
 906         s64 idle_time_ns;
 907         s64 idle_time;
 908
 909
 910         pr = __this_cpu_read(processors);
 911         dev->last_residency = 0;
 912
 913         if (unlikely(!pr))
 914                 return -EINVAL;
 915
 916         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 917                 if (drv->safe_state_index >= 0) {
 918                         return drv->states[drv->safe_state_index].enter(dev,
 919                                                 drv, drv->safe_state_index);
 920                 } else {
 921                         local_irq_disable();
 922                         acpi_safe_halt();
 923                         local_irq_enable();
 924                         return -EINVAL;
 925                 }
 926         }
 927
 928         local_irq_disable();
 929
 930         if (cx->entry_method != ACPI_CSTATE_FFH) {
 931                 current_thread_info()->status &= ~TS_POLLING;
 932                 /*
 933                  * TS_POLLING-cleared state must be visible before we test
 934                  * NEED_RESCHED:
 935                  */
 936                 smp_mb();
 937
 938                 if (unlikely(need_resched())) {
 939                         current_thread_info()->status |= TS_POLLING;
 940                         local_irq_enable();
 941                         return -EINVAL;
 942                 }
 943         }
 944
 945         acpi_unlazy_tlb(smp_processor_id());
 946
 947         /* Tell the scheduler that we are going deep-idle: */
 948         sched_clock_idle_sleep_event();
 949         /*
 950          * Must be done before busmaster disable as we might need to
 951          * access HPET !
 952          */
 953         lapic_timer_state_broadcast(pr, cx, 1);
 954
 955         kt1 = ktime_get_real();
 956         /*
 957          * disable bus master
 958          * bm_check implies we need ARB_DIS
 959          * !bm_check implies we need cache flush
 960          * bm_control implies whether we can do ARB_DIS
 961          *
 962          * That leaves a case where bm_check is set and bm_control is
 963          * not set. In that case we cannot do much, we enter C3
 964          * without doing anything.
 965          */
 966         if (pr->flags.bm_check && pr->flags.bm_control) {
 967                 raw_spin_lock(&c3_lock);
 968                 c3_cpu_count++;
 969                 /* Disable bus master arbitration when all CPUs are in C3 */
 970                 if (c3_cpu_count == num_online_cpus())
 971                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 972                 raw_spin_unlock(&c3_lock);
 973         } else if (!pr->flags.bm_check) {
 974                 ACPI_FLUSH_CPU_CACHE();
 975         }
 976
 977         acpi_idle_do_entry(cx);
 978
 979         /* Re-enable bus master arbitration */
 980         if (pr->flags.bm_check && pr->flags.bm_control) {
 981                 raw_spin_lock(&c3_lock);
 982                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 983                 c3_cpu_count--;
 984                 raw_spin_unlock(&c3_lock);
 985         }
 986         kt2 = ktime_get_real();
 987         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
 988         idle_time = idle_time_ns;
 989         do_div(idle_time, NSEC_PER_USEC);
 990
 991         /* Update device last_residency*/
 992         dev->last_residency = (int)idle_time;
 993
 994         /* Tell the scheduler how much we idled: */
 995         sched_clock_idle_wakeup_event(idle_time_ns);
 996
 997         local_irq_enable();
 998         if (cx->entry_method != ACPI_CSTATE_FFH)
 999                 current_thread_info()->status |= TS_POLLING;
1000
1001         cx->usage++;
1002
1003         lapic_timer_state_broadcast(pr, cx, 0);
1004         cx->time += idle_time;
1005         return index;
1006 }
1007
1008 struct cpuidle_driver acpi_idle_driver = {
1009         .name =         "acpi_idle",
1010         .owner =        THIS_MODULE,
1011 };
1012
1013 /**
1014  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
1015  * device i.e. per-cpu data
1016  *
1017  * @pr: the ACPI processor
1018  */
1019 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
1020 {
1021         int i, count = CPUIDLE_DRIVER_STATE_START;
1022         struct acpi_processor_cx *cx;
1023         struct cpuidle_state_usage *state_usage;
1024         struct cpuidle_device *dev = &pr->power.dev;
1025
1026         if (!pr->flags.power_setup_done)
1027                 return -EINVAL;
1028
1029         if (pr->flags.power == 0) {
1030                 return -EINVAL;
1031         }
1032
1033         dev->cpu = pr->id;
1034
1035         if (max_cstate == 0)
1036                 max_cstate = 1;
1037
1038         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1039                 cx = &pr->power.states[i];
1040                 state_usage = &dev->states_usage[count];
1041
1042                 if (!cx->valid)
1043                         continue;
1044
1045 #ifdef CONFIG_HOTPLUG_CPU
1046                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1047                     !pr->flags.has_cst &&
1048                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1049                         continue;
1050 #endif
1051
1052                 cpuidle_set_statedata(state_usage, cx);
1053
1054                 count++;
1055                 if (count == CPUIDLE_STATE_MAX)
1056                         break;
1057         }
1058
1059         dev->state_count = count;
1060
1061         if (!count)
1062                 return -EINVAL;
1063
1064         return 0;
1065 }
1066
1067 /**
1068  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
1069  * global state data i.e. idle routines
1070  *
1071  * @pr: the ACPI processor
1072  */
1073 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1074 {
1075         int i, count = CPUIDLE_DRIVER_STATE_START;
1076         struct acpi_processor_cx *cx;
1077         struct cpuidle_state *state;
1078         struct cpuidle_driver *drv = &acpi_idle_driver;
1079
1080         if (!pr->flags.power_setup_done)
1081                 return -EINVAL;
1082
1083         if (pr->flags.power == 0)
1084                 return -EINVAL;
1085
1086         drv->safe_state_index = -1;
1087         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1088                 drv->states[i].name[0] = '\0';
1089                 drv->states[i].desc[0] = '\0';
1090         }
1091
1092         if (max_cstate == 0)
1093                 max_cstate = 1;
1094
1095         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1096                 cx = &pr->power.states[i];
1097
1098                 if (!cx->valid)
1099                         continue;
1100
1101 #ifdef CONFIG_HOTPLUG_CPU
1102                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1103                     !pr->flags.has_cst &&
1104                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1105                         continue;
1106 #endif
1107
1108                 state = &drv->states[count];
1109                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1110                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1111                 state->exit_latency = cx->latency;
1112                 state->target_residency = cx->latency * latency_factor;
1113
1114                 state->flags = 0;
1115                 switch (cx->type) {
1116                         case ACPI_STATE_C1:
1117                         if (cx->entry_method == ACPI_CSTATE_FFH)
1118                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1119
1120                         state->enter = acpi_idle_enter_c1;
1121                         state->enter_dead = acpi_idle_play_dead;
1122                         drv->safe_state_index = count;
1123                         break;
1124
1125                         case ACPI_STATE_C2:
1126                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1127                         state->enter = acpi_idle_enter_simple;
1128                         state->enter_dead = acpi_idle_play_dead;
1129                         drv->safe_state_index = count;
1130                         break;
1131
1132                         case ACPI_STATE_C3:
1133                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1134                         state->enter = pr->flags.bm_check ?
1135                                         acpi_idle_enter_bm :
1136                                         acpi_idle_enter_simple;
1137                         break;
1138                 }
1139
1140                 count++;
1141                 if (count == CPUIDLE_STATE_MAX)
1142                         break;
1143         }
1144
1145         drv->state_count = count;
1146
1147         if (!count)
1148                 return -EINVAL;
1149
1150         return 0;
1151 }
1152 #else
1153 static void acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr) {}
1154 static void acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) {}
1155 #endif /* CONFIG_PROCESSOR_EXTERNAL_CONTROL */
1156
1157 int acpi_processor_hotplug(struct acpi_processor *pr)
1158 {
1159         int ret = 0;
1160
1161         if (disabled_by_idle_boot_param())
1162                 return 0;
1163
1164         if (!pr)
1165                 return -EINVAL;
1166
1167         if (nocst) {
1168                 return -ENODEV;
1169         }
1170
1171         if (!pr->flags.power_setup_done)
1172                 return -ENODEV;
1173
1174         if (processor_pm_external()) {
1175                 pr->flags.power = 0;
1176                 ret = acpi_processor_get_power_info(pr);
1177                 processor_notify_external(pr,
1178                         PROCESSOR_PM_CHANGE, PM_TYPE_IDLE);
1179                 return ret;
1180         }
1181
1182         cpuidle_pause_and_lock();
1183         cpuidle_disable_device(&pr->power.dev);
1184         acpi_processor_get_power_info(pr);
1185         if (pr->flags.power) {
1186                 acpi_processor_setup_cpuidle_cx(pr);
1187                 ret = cpuidle_enable_device(&pr->power.dev);
1188         }
1189         cpuidle_resume_and_unlock();
1190
1191         return ret;
1192 }
1193
1194 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1195 {
1196         int cpu;
1197         struct acpi_processor *_pr;
1198
1199         if (disabled_by_idle_boot_param())
1200                 return 0;
1201
1202         if (!pr)
1203                 return -EINVAL;
1204
1205         if (nocst)
1206                 return -ENODEV;
1207
1208         if (!pr->flags.power_setup_done)
1209                 return -ENODEV;
1210
1211         /*
1212          * FIXME:  Design the ACPI notification to make it once per
1213          * system instead of once per-cpu.  This condition is a hack
1214          * to make the code that updates C-States be called once.
1215          */
1216
1217         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1218
1219                 cpuidle_pause_and_lock();
1220                 /* Protect against cpu-hotplug */
1221                 get_online_cpus();
1222
1223                 /* Disable all cpuidle devices */
1224                 for_each_online_cpu(cpu) {
1225                         _pr = per_cpu(processors, cpu);
1226                         if (!_pr || !_pr->flags.power_setup_done)
1227                                 continue;
1228                         cpuidle_disable_device(&_pr->power.dev);
1229                 }
1230
1231                 /* Populate Updated C-state information */
1232                 acpi_processor_setup_cpuidle_states(pr);
1233
1234                 /* Enable all cpuidle devices */
1235                 for_each_online_cpu(cpu) {
1236                         _pr = per_cpu(processors, cpu);
1237                         if (!_pr || !_pr->flags.power_setup_done)
1238                                 continue;
1239                         acpi_processor_get_power_info(_pr);
1240                         if (_pr->flags.power) {
1241                                 acpi_processor_setup_cpuidle_cx(_pr);
1242                                 cpuidle_enable_device(&_pr->power.dev);
1243                         }
1244                 }
1245                 put_online_cpus();
1246                 cpuidle_resume_and_unlock();
1247         }
1248
1249         return 0;
1250 }
1251
1252 static int acpi_processor_registered;
1253
1254 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1255                               struct acpi_device *device)
1256 {
1257         acpi_status status = 0;
1258         static int first_run;
1259
1260         if (disabled_by_idle_boot_param())
1261                 return 0;
1262
1263         if (!first_run) {
1264                 dmi_check_system(processor_power_dmi_table);
1265                 max_cstate = acpi_processor_cstate_check(max_cstate);
1266                 if (max_cstate < ACPI_C_STATES_MAX)
1267                         printk(KERN_NOTICE
1268                                "ACPI: processor limited to max C-state %d\n",
1269                                max_cstate);
1270                 first_run++;
1271         }
1272
1273         if (!pr)
1274                 return -EINVAL;
1275
1276         if (acpi_gbl_FADT.cst_control && !nocst) {
1277                 status =
1278                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1279                 if (ACPI_FAILURE(status)) {
1280                         ACPI_EXCEPTION((AE_INFO, status,
1281                                         "Notifying BIOS of _CST ability failed"));
1282                 }
1283         }
1284
1285         acpi_processor_get_power_info(pr);
1286         pr->flags.power_setup_done = 1;
1287
1288 #ifndef CONFIG_PROCESSOR_EXTERNAL_CONTROL
1289         /*
1290          * Install the idle handler if processor power management is supported.
1291          * Note that we use previously set idle handler will be used on
1292          * platforms that only support C1.
1293          */
1294         if (pr->flags.power) {
1295                 int retval;
1296
1297                 /* Register acpi_idle_driver if not already registered */
1298                 if (!acpi_processor_registered) {
1299                         acpi_processor_setup_cpuidle_states(pr);
1300                         retval = cpuidle_register_driver(&acpi_idle_driver);
1301                         if (retval)
1302                                 return retval;
1303                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1304                                         acpi_idle_driver.name);
1305                 }
1306                 /* Register per-cpu cpuidle_device. Cpuidle driver
1307                  * must already be registered before registering device
1308                  */
1309                 acpi_processor_setup_cpuidle_cx(pr);
1310                 retval = cpuidle_register_device(&pr->power.dev);
1311                 if (retval) {
1312                         if (acpi_processor_registered == 0)
1313                                 cpuidle_unregister_driver(&acpi_idle_driver);
1314                         return retval;
1315                 }
1316                 acpi_processor_registered++;
1317         }
1318 #endif
1319
1320         if (processor_pm_external())
1321                 processor_notify_external(pr,
1322                         PROCESSOR_PM_INIT, PM_TYPE_IDLE);
1323
1324         return 0;
1325 }
1326
1327 int acpi_processor_power_exit(struct acpi_processor *pr,
1328                               struct acpi_device *device)
1329 {
1330         if (disabled_by_idle_boot_param())
1331                 return 0;
1332
1333         if (pr->flags.power) {
1334                 cpuidle_unregister_device(&pr->power.dev);
1335                 acpi_processor_registered--;
1336                 if (acpi_processor_registered == 0)
1337                         cpuidle_unregister_driver(&acpi_idle_driver);
1338         }
1339
1340         pr->flags.power_setup_done = 0;
1341         return 0;
1342 }