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 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
  77 static unsigned int latency_factor __read_mostly = 2;
  78 module_param(latency_factor, uint, 0644);
  79
  80 static s64 us_to_pm_timer_ticks(s64 t)
  81 {
  82         return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
  83 }
  84 /*
  85  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  86  * For now disable this. Probably a bug somewhere else.
  87  *
  88  * To skip this limit, boot/load with a large max_cstate limit.
  89  */
  90 static int set_max_cstate(const struct dmi_system_id *id)
  91 {
  92         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  93                 return 0;
  94
  95         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  96                " Override with \"processor.max_cstate=%d\"\n", id->ident,
  97                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  98
  99         max_cstate = (long)id->driver_data;
 100
 101         return 0;
 102 }
 103
 104 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 105    callers to only run once -AK */
 106 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 107         { set_max_cstate, "Clevo 5600D", {
 108           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 109           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 110          (void *)2},
 111         {},
 112 };
 113
 114
 115 /*
 116  * Callers should disable interrupts before the call and enable
 117  * interrupts after return.
 118  */
 119 static void acpi_safe_halt(void)
 120 {
 121         current_thread_info()->status &= ~TS_POLLING;
 122         /*
 123          * TS_POLLING-cleared state must be visible before we
 124          * test NEED_RESCHED:
 125          */
 126         smp_mb();
 127         if (!need_resched()) {
 128                 safe_halt();
 129                 local_irq_disable();
 130         }
 131         current_thread_info()->status |= TS_POLLING;
 132 }
 133
 134 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 135
 136 /*
 137  * Some BIOS implementations switch to C3 in the published C2 state.
 138  * This seems to be a common problem on AMD boxen, but other vendors
 139  * are affected too. We pick the most conservative approach: we assume
 140  * that the local APIC stops in both C2 and C3.
 141  */
 142 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 143                                    struct acpi_processor_cx *cx)
 144 {
 145         struct acpi_processor_power *pwr = &pr->power;
 146         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 147
 148         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 149                 return;
 150
 151         if (boot_cpu_has(X86_FEATURE_AMDC1E))
 152                 type = ACPI_STATE_C1;
 153
 154         /*
 155          * Check, if one of the previous states already marked the lapic
 156          * unstable
 157          */
 158         if (pwr->timer_broadcast_on_state < state)
 159                 return;
 160
 161         if (cx->type >= type)
 162                 pr->power.timer_broadcast_on_state = state;
 163 }
 164
 165 static void lapic_timer_propagate_broadcast(void *arg)
 166 {
 167         struct acpi_processor *pr = (struct acpi_processor *) arg;
 168         unsigned long reason;
 169
 170         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 171                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 172
 173         clockevents_notify(reason, &pr->id);
 174 }
 175
 176 /* Power(C) State timer broadcast control */
 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 178                                        struct acpi_processor_cx *cx,
 179                                        int broadcast)
 180 {
 181         int state = cx - pr->power.states;
 182
 183         if (state >= pr->power.timer_broadcast_on_state) {
 184                 unsigned long reason;
 185
 186                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 187                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 188                 clockevents_notify(reason, &pr->id);
 189         }
 190 }
 191
 192 #else
 193
 194 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 195                                    struct acpi_processor_cx *cstate) { }
 196 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 197 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 198                                        struct acpi_processor_cx *cx,
 199                                        int broadcast)
 200 {
 201 }
 202
 203 #endif
 204
 205 /*
 206  * Suspend / resume control
 207  */
 208 static int acpi_idle_suspend;
 209 static u32 saved_bm_rld;
 210
 211 static void acpi_idle_bm_rld_save(void)
 212 {
 213         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 214 }
 215 static void acpi_idle_bm_rld_restore(void)
 216 {
 217         u32 resumed_bm_rld;
 218
 219         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 220
 221         if (resumed_bm_rld != saved_bm_rld)
 222                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 223 }
 224
 225 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 226 {
 227         if (acpi_idle_suspend == 1)
 228                 return 0;
 229
 230         acpi_idle_bm_rld_save();
 231         acpi_idle_suspend = 1;
 232         return 0;
 233 }
 234
 235 int acpi_processor_resume(struct acpi_device * device)
 236 {
 237         if (acpi_idle_suspend == 0)
 238                 return 0;
 239
 240         acpi_idle_bm_rld_restore();
 241         acpi_idle_suspend = 0;
 242         return 0;
 243 }
 244
 245 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 246 static void tsc_check_state(int state)
 247 {
 248         switch (boot_cpu_data.x86_vendor) {
 249         case X86_VENDOR_AMD:
 250         case X86_VENDOR_INTEL:
 251                 /*
 252                  * AMD Fam10h TSC will tick in all
 253                  * C/P/S0/S1 states when this bit is set.
 254                  */
 255                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 256                         return;
 257
 258                 /*FALL THROUGH*/
 259         default:
 260                 /* TSC could halt in idle, so notify users */
 261                 if (state > ACPI_STATE_C1)
 262                         mark_tsc_unstable("TSC halts in idle");
 263         }
 264 }
 265 #else
 266 static void tsc_check_state(int state) { return; }
 267 #endif
 268
 269 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 270 {
 271
 272         if (!pr)
 273                 return -EINVAL;
 274
 275         if (!pr->pblk)
 276                 return -ENODEV;
 277
 278         /* if info is obtained from pblk/fadt, type equals state */
 279         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 280         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 281
 282 #ifndef CONFIG_HOTPLUG_CPU
 283         /*
 284          * Check for P_LVL2_UP flag before entering C2 and above on
 285          * an SMP system.
 286          */
 287         if ((num_online_cpus() > 1) &&
 288             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 289                 return -ENODEV;
 290 #endif
 291
 292         /* determine C2 and C3 address from pblk */
 293         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 294         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 295
 296         /* determine latencies from FADT */
 297         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 298         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 299
 300         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 301                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 302                           pr->power.states[ACPI_STATE_C2].address,
 303                           pr->power.states[ACPI_STATE_C3].address));
 304
 305         return 0;
 306 }
 307
 308 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 309 {
 310         if (!pr->power.states[ACPI_STATE_C1].valid) {
 311                 /* set the first C-State to C1 */
 312                 /* all processors need to support C1 */
 313                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 314                 pr->power.states[ACPI_STATE_C1].valid = 1;
 315                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 316         }
 317         /* the C0 state only exists as a filler in our array */
 318         pr->power.states[ACPI_STATE_C0].valid = 1;
 319         return 0;
 320 }
 321
 322 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 323 {
 324         acpi_status status = 0;
 325         acpi_integer count;
 326         int current_count;
 327         int i;
 328         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 329         union acpi_object *cst;
 330
 331
 332         if (nocst)
 333                 return -ENODEV;
 334
 335         current_count = 0;
 336
 337         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 338         if (ACPI_FAILURE(status)) {
 339                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 340                 return -ENODEV;
 341         }
 342
 343         cst = buffer.pointer;
 344
 345         /* There must be at least 2 elements */
 346         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 347                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 348                 status = -EFAULT;
 349                 goto end;
 350         }
 351
 352         count = cst->package.elements[0].integer.value;
 353
 354         /* Validate number of power states. */
 355         if (count < 1 || count != cst->package.count - 1) {
 356                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 357                 status = -EFAULT;
 358                 goto end;
 359         }
 360
 361         /* Tell driver that at least _CST is supported. */
 362         pr->flags.has_cst = 1;
 363
 364         for (i = 1; i <= count; i++) {
 365                 union acpi_object *element;
 366                 union acpi_object *obj;
 367                 struct acpi_power_register *reg;
 368                 struct acpi_processor_cx cx;
 369
 370                 memset(&cx, 0, sizeof(cx));
 371
 372                 element = &(cst->package.elements[i]);
 373                 if (element->type != ACPI_TYPE_PACKAGE)
 374                         continue;
 375
 376                 if (element->package.count != 4)
 377                         continue;
 378
 379                 obj = &(element->package.elements[0]);
 380
 381                 if (obj->type != ACPI_TYPE_BUFFER)
 382                         continue;
 383
 384                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 385
 386                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 387                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 388                         continue;
 389
 390                 /* There should be an easy way to extract an integer... */
 391                 obj = &(element->package.elements[1]);
 392                 if (obj->type != ACPI_TYPE_INTEGER)
 393                         continue;
 394
 395                 cx.type = obj->integer.value;
 396                 /*
 397                  * Some buggy BIOSes won't list C1 in _CST -
 398                  * Let acpi_processor_get_power_info_default() handle them later
 399                  */
 400                 if (i == 1 && cx.type != ACPI_STATE_C1)
 401                         current_count++;
 402
 403                 cx.address = reg->address;
 404                 cx.index = current_count + 1;
 405
 406                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 407                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 408                         if (acpi_processor_ffh_cstate_probe
 409                                         (pr->id, &cx, reg) == 0) {
 410                                 cx.entry_method = ACPI_CSTATE_FFH;
 411                         } else if (cx.type == ACPI_STATE_C1) {
 412                                 /*
 413                                  * C1 is a special case where FIXED_HARDWARE
 414                                  * can be handled in non-MWAIT way as well.
 415                                  * In that case, save this _CST entry info.
 416                                  * Otherwise, ignore this info and continue.
 417                                  */
 418                                 cx.entry_method = ACPI_CSTATE_HALT;
 419                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 420                         } else {
 421                                 continue;
 422                         }
 423                         if (cx.type == ACPI_STATE_C1 &&
 424                                         (idle_halt || idle_nomwait)) {
 425                                 /*
 426                                  * In most cases the C1 space_id obtained from
 427                                  * _CST object is FIXED_HARDWARE access mode.
 428                                  * But when the option of idle=halt is added,
 429                                  * the entry_method type should be changed from
 430                                  * CSTATE_FFH to CSTATE_HALT.
 431                                  * When the option of idle=nomwait is added,
 432                                  * the C1 entry_method type should be
 433                                  * CSTATE_HALT.
 434                                  */
 435                                 cx.entry_method = ACPI_CSTATE_HALT;
 436                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 437                         }
 438                 } else {
 439                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 440                                  cx.address);
 441                 }
 442
 443                 if (cx.type == ACPI_STATE_C1) {
 444                         cx.valid = 1;
 445                 }
 446
 447                 obj = &(element->package.elements[2]);
 448                 if (obj->type != ACPI_TYPE_INTEGER)
 449                         continue;
 450
 451                 cx.latency = obj->integer.value;
 452
 453                 obj = &(element->package.elements[3]);
 454                 if (obj->type != ACPI_TYPE_INTEGER)
 455                         continue;
 456
 457                 cx.power = obj->integer.value;
 458
 459                 current_count++;
 460                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 461
 462                 /*
 463                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 464                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 465                  */
 466                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 467                         printk(KERN_WARNING
 468                                "Limiting number of power states to max (%d)\n",
 469                                ACPI_PROCESSOR_MAX_POWER);
 470                         printk(KERN_WARNING
 471                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 472                         break;
 473                 }
 474         }
 475
 476         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 477                           current_count));
 478
 479         /* Validate number of power states discovered */
 480         if (current_count < 2)
 481                 status = -EFAULT;
 482
 483       end:
 484         kfree(buffer.pointer);
 485
 486         return status;
 487 }
 488
 489 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 490 {
 491
 492         if (!cx->address)
 493                 return;
 494
 495         /*
 496          * C2 latency must be less than or equal to 100
 497          * microseconds.
 498          */
 499         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 500                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 501                                   "latency too large [%d]\n", cx->latency));
 502                 return;
 503         }
 504
 505         /*
 506          * Otherwise we've met all of our C2 requirements.
 507          * Normalize the C2 latency to expidite policy
 508          */
 509         cx->valid = 1;
 510
 511         cx->latency_ticks = cx->latency;
 512
 513         return;
 514 }
 515
 516 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 517                                            struct acpi_processor_cx *cx)
 518 {
 519         static int bm_check_flag = -1;
 520         static int bm_control_flag = -1;
 521
 522
 523         if (!cx->address)
 524                 return;
 525
 526         /*
 527          * C3 latency must be less than or equal to 1000
 528          * microseconds.
 529          */
 530         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 531                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 532                                   "latency too large [%d]\n", cx->latency));
 533                 return;
 534         }
 535
 536         /*
 537          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 538          * DMA transfers are used by any ISA device to avoid livelock.
 539          * Note that we could disable Type-F DMA (as recommended by
 540          * the erratum), but this is known to disrupt certain ISA
 541          * devices thus we take the conservative approach.
 542          */
 543         else if (errata.piix4.fdma) {
 544                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 545                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 546                 return;
 547         }
 548
 549         /* All the logic here assumes flags.bm_check is same across all CPUs */
 550         if (bm_check_flag == -1) {
 551                 /* Determine whether bm_check is needed based on CPU  */
 552                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 553                 bm_check_flag = pr->flags.bm_check;
 554                 bm_control_flag = pr->flags.bm_control;
 555         } else {
 556                 pr->flags.bm_check = bm_check_flag;
 557                 pr->flags.bm_control = bm_control_flag;
 558         }
 559
 560         if (pr->flags.bm_check) {
 561                 if (!pr->flags.bm_control) {
 562                         if (pr->flags.has_cst != 1) {
 563                                 /* bus mastering control is necessary */
 564                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 565                                         "C3 support requires BM control\n"));
 566                                 return;
 567                         } else {
 568                                 /* Here we enter C3 without bus mastering */
 569                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 570                                         "C3 support without BM control\n"));
 571                         }
 572                 }
 573         } else {
 574                 /*
 575                  * WBINVD should be set in fadt, for C3 state to be
 576                  * supported on when bm_check is not required.
 577                  */
 578                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 579                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 580                                           "Cache invalidation should work properly"
 581                                           " for C3 to be enabled on SMP systems\n"));
 582                         return;
 583                 }
 584         }
 585
 586         /*
 587          * Otherwise we've met all of our C3 requirements.
 588          * Normalize the C3 latency to expidite policy.  Enable
 589          * checking of bus mastering status (bm_check) so we can
 590          * use this in our C3 policy
 591          */
 592         cx->valid = 1;
 593
 594         cx->latency_ticks = cx->latency;
 595         /*
 596          * On older chipsets, BM_RLD needs to be set
 597          * in order for Bus Master activity to wake the
 598          * system from C3.  Newer chipsets handle DMA
 599          * during C3 automatically and BM_RLD is a NOP.
 600          * In either case, the proper way to
 601          * handle BM_RLD is to set it and leave it set.
 602          */
 603         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 604
 605         return;
 606 }
 607
 608 static int acpi_processor_power_verify(struct acpi_processor *pr)
 609 {
 610         unsigned int i;
 611         unsigned int working = 0;
 612
 613         pr->power.timer_broadcast_on_state = INT_MAX;
 614
 615         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 616                 struct acpi_processor_cx *cx = &pr->power.states[i];
 617
 618                 switch (cx->type) {
 619                 case ACPI_STATE_C1:
 620                         cx->valid = 1;
 621                         break;
 622
 623                 case ACPI_STATE_C2:
 624                         acpi_processor_power_verify_c2(cx);
 625                         break;
 626
 627                 case ACPI_STATE_C3:
 628                         acpi_processor_power_verify_c3(pr, cx);
 629                         break;
 630                 }
 631                 if (!cx->valid)
 632                         continue;
 633
 634                 lapic_timer_check_state(i, pr, cx);
 635                 tsc_check_state(cx->type);
 636                 working++;
 637         }
 638
 639         smp_call_function_single(pr->id, lapic_timer_propagate_broadcast,
 640                                  pr, 1);
 641
 642         return (working);
 643 }
 644
 645 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 646 {
 647         unsigned int i;
 648         int result;
 649
 650
 651         /* NOTE: the idle thread may not be running while calling
 652          * this function */
 653
 654         /* Zero initialize all the C-states info. */
 655         memset(pr->power.states, 0, sizeof(pr->power.states));
 656
 657         result = acpi_processor_get_power_info_cst(pr);
 658         if (result == -ENODEV)
 659                 result = acpi_processor_get_power_info_fadt(pr);
 660
 661         if (result)
 662                 return result;
 663
 664         acpi_processor_get_power_info_default(pr);
 665
 666         pr->power.count = acpi_processor_power_verify(pr);
 667
 668         /*
 669          * if one state of type C2 or C3 is available, mark this
 670          * CPU as being "idle manageable"
 671          */
 672         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 673                 if (pr->power.states[i].valid) {
 674                         pr->power.count = i;
 675                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 676                                 pr->flags.power = 1;
 677                 }
 678         }
 679
 680         return 0;
 681 }
 682
 683 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 684 {
 685         struct acpi_processor *pr = seq->private;
 686         unsigned int i;
 687
 688
 689         if (!pr)
 690                 goto end;
 691
 692         seq_printf(seq, "active state:            C%zd\n"
 693                    "max_cstate:              C%d\n"
 694                    "maximum allowed latency: %d usec\n",
 695                    pr->power.state ? pr->power.state - pr->power.states : 0,
 696                    max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
 697
 698         seq_puts(seq, "states:\n");
 699
 700         for (i = 1; i <= pr->power.count; i++) {
 701                 seq_printf(seq, "   %cC%d:                  ",
 702                            (&pr->power.states[i] ==
 703                             pr->power.state ? '*' : ' '), i);
 704
 705                 if (!pr->power.states[i].valid) {
 706                         seq_puts(seq, "<not supported>\n");
 707                         continue;
 708                 }
 709
 710                 switch (pr->power.states[i].type) {
 711                 case ACPI_STATE_C1:
 712                         seq_printf(seq, "type[C1] ");
 713                         break;
 714                 case ACPI_STATE_C2:
 715                         seq_printf(seq, "type[C2] ");
 716                         break;
 717                 case ACPI_STATE_C3:
 718                         seq_printf(seq, "type[C3] ");
 719                         break;
 720                 default:
 721                         seq_printf(seq, "type[--] ");
 722                         break;
 723                 }
 724
 725                 if (pr->power.states[i].promotion.state)
 726                         seq_printf(seq, "promotion[C%zd] ",
 727                                    (pr->power.states[i].promotion.state -
 728                                     pr->power.states));
 729                 else
 730                         seq_puts(seq, "promotion[--] ");
 731
 732                 if (pr->power.states[i].demotion.state)
 733                         seq_printf(seq, "demotion[C%zd] ",
 734                                    (pr->power.states[i].demotion.state -
 735                                     pr->power.states));
 736                 else
 737                         seq_puts(seq, "demotion[--] ");
 738
 739                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
 740                            pr->power.states[i].latency,
 741                            pr->power.states[i].usage,
 742                            (unsigned long long)pr->power.states[i].time);
 743         }
 744
 745       end:
 746         return 0;
 747 }
 748
 749 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 750 {
 751         return single_open(file, acpi_processor_power_seq_show,
 752                            PDE(inode)->data);
 753 }
 754
 755 static const struct file_operations acpi_processor_power_fops = {
 756         .owner = THIS_MODULE,
 757         .open = acpi_processor_power_open_fs,
 758         .read = seq_read,
 759         .llseek = seq_lseek,
 760         .release = single_release,
 761 };
 762
 763
 764 /**
 765  * acpi_idle_bm_check - checks if bus master activity was detected
 766  */
 767 static int acpi_idle_bm_check(void)
 768 {
 769         u32 bm_status = 0;
 770
 771         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 772         if (bm_status)
 773                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 774         /*
 775          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 776          * the true state of bus mastering activity; forcing us to
 777          * manually check the BMIDEA bit of each IDE channel.
 778          */
 779         else if (errata.piix4.bmisx) {
 780                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 781                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 782                         bm_status = 1;
 783         }
 784         return bm_status;
 785 }
 786
 787 /**
 788  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 789  * @cx: cstate data
 790  *
 791  * Caller disables interrupt before call and enables interrupt after return.
 792  */
 793 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 794 {
 795         /* Don't trace irqs off for idle */
 796         stop_critical_timings();
 797         if (cx->entry_method == ACPI_CSTATE_FFH) {
 798                 /* Call into architectural FFH based C-state */
 799                 acpi_processor_ffh_cstate_enter(cx);
 800         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 801                 acpi_safe_halt();
 802         } else {
 803                 int unused;
 804                 /* IO port based C-state */
 805                 inb(cx->address);
 806                 /* Dummy wait op - must do something useless after P_LVL2 read
 807                    because chipsets cannot guarantee that STPCLK# signal
 808                    gets asserted in time to freeze execution properly. */
 809                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 810         }
 811         start_critical_timings();
 812 }
 813
 814 /**
 815  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 816  * @dev: the target CPU
 817  * @state: the state data
 818  *
 819  * This is equivalent to the HALT instruction.
 820  */
 821 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 822                               struct cpuidle_state *state)
 823 {
 824         ktime_t  kt1, kt2;
 825         s64 idle_time;
 826         struct acpi_processor *pr;
 827         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 828
 829         pr = __get_cpu_var(processors);
 830
 831         if (unlikely(!pr))
 832                 return 0;
 833
 834         local_irq_disable();
 835
 836         /* Do not access any ACPI IO ports in suspend path */
 837         if (acpi_idle_suspend) {
 838                 local_irq_enable();
 839                 cpu_relax();
 840                 return 0;
 841         }
 842
 843         lapic_timer_state_broadcast(pr, cx, 1);
 844         kt1 = ktime_get_real();
 845         acpi_idle_do_entry(cx);
 846         kt2 = ktime_get_real();
 847         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 848
 849         local_irq_enable();
 850         cx->usage++;
 851         lapic_timer_state_broadcast(pr, cx, 0);
 852
 853         return idle_time;
 854 }
 855
 856 /**
 857  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 858  * @dev: the target CPU
 859  * @state: the state data
 860  */
 861 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 862                                   struct cpuidle_state *state)
 863 {
 864         struct acpi_processor *pr;
 865         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 866         ktime_t  kt1, kt2;
 867         s64 idle_time;
 868         s64 sleep_ticks = 0;
 869
 870         pr = __get_cpu_var(processors);
 871
 872         if (unlikely(!pr))
 873                 return 0;
 874
 875         if (acpi_idle_suspend)
 876                 return(acpi_idle_enter_c1(dev, state));
 877
 878         local_irq_disable();
 879         current_thread_info()->status &= ~TS_POLLING;
 880         /*
 881          * TS_POLLING-cleared state must be visible before we test
 882          * NEED_RESCHED:
 883          */
 884         smp_mb();
 885
 886         if (unlikely(need_resched())) {
 887                 current_thread_info()->status |= TS_POLLING;
 888                 local_irq_enable();
 889                 return 0;
 890         }
 891
 892         /*
 893          * Must be done before busmaster disable as we might need to
 894          * access HPET !
 895          */
 896         lapic_timer_state_broadcast(pr, cx, 1);
 897
 898         if (cx->type == ACPI_STATE_C3)
 899                 ACPI_FLUSH_CPU_CACHE();
 900
 901         kt1 = ktime_get_real();
 902         /* Tell the scheduler that we are going deep-idle: */
 903         sched_clock_idle_sleep_event();
 904         acpi_idle_do_entry(cx);
 905         kt2 = ktime_get_real();
 906         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 907
 908         sleep_ticks = us_to_pm_timer_ticks(idle_time);
 909
 910         /* Tell the scheduler how much we idled: */
 911         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 912
 913         local_irq_enable();
 914         current_thread_info()->status |= TS_POLLING;
 915
 916         cx->usage++;
 917
 918         lapic_timer_state_broadcast(pr, cx, 0);
 919         cx->time += sleep_ticks;
 920         return idle_time;
 921 }
 922
 923 static int c3_cpu_count;
 924 static DEFINE_SPINLOCK(c3_lock);
 925
 926 /**
 927  * acpi_idle_enter_bm - enters C3 with proper BM handling
 928  * @dev: the target CPU
 929  * @state: the state data
 930  *
 931  * If BM is detected, the deepest non-C3 idle state is entered instead.
 932  */
 933 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 934                               struct cpuidle_state *state)
 935 {
 936         struct acpi_processor *pr;
 937         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 938         ktime_t  kt1, kt2;
 939         s64 idle_time;
 940         s64 sleep_ticks = 0;
 941
 942
 943         pr = __get_cpu_var(processors);
 944
 945         if (unlikely(!pr))
 946                 return 0;
 947
 948         if (acpi_idle_suspend)
 949                 return(acpi_idle_enter_c1(dev, state));
 950
 951         if (acpi_idle_bm_check()) {
 952                 if (dev->safe_state) {
 953                         dev->last_state = dev->safe_state;
 954                         return dev->safe_state->enter(dev, dev->safe_state);
 955                 } else {
 956                         local_irq_disable();
 957                         acpi_safe_halt();
 958                         local_irq_enable();
 959                         return 0;
 960                 }
 961         }
 962
 963         local_irq_disable();
 964         current_thread_info()->status &= ~TS_POLLING;
 965         /*
 966          * TS_POLLING-cleared state must be visible before we test
 967          * NEED_RESCHED:
 968          */
 969         smp_mb();
 970
 971         if (unlikely(need_resched())) {
 972                 current_thread_info()->status |= TS_POLLING;
 973                 local_irq_enable();
 974                 return 0;
 975         }
 976
 977         acpi_unlazy_tlb(smp_processor_id());
 978
 979         /* Tell the scheduler that we are going deep-idle: */
 980         sched_clock_idle_sleep_event();
 981         /*
 982          * Must be done before busmaster disable as we might need to
 983          * access HPET !
 984          */
 985         lapic_timer_state_broadcast(pr, cx, 1);
 986
 987         kt1 = ktime_get_real();
 988         /*
 989          * disable bus master
 990          * bm_check implies we need ARB_DIS
 991          * !bm_check implies we need cache flush
 992          * bm_control implies whether we can do ARB_DIS
 993          *
 994          * That leaves a case where bm_check is set and bm_control is
 995          * not set. In that case we cannot do much, we enter C3
 996          * without doing anything.
 997          */
 998         if (pr->flags.bm_check && pr->flags.bm_control) {
 999                 spin_lock(&c3_lock);
1000                 c3_cpu_count++;
1001                 /* Disable bus master arbitration when all CPUs are in C3 */
1002                 if (c3_cpu_count == num_online_cpus())
1003                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
1004                 spin_unlock(&c3_lock);
1005         } else if (!pr->flags.bm_check) {
1006                 ACPI_FLUSH_CPU_CACHE();
1007         }
1008
1009         acpi_idle_do_entry(cx);
1010
1011         /* Re-enable bus master arbitration */
1012         if (pr->flags.bm_check && pr->flags.bm_control) {
1013                 spin_lock(&c3_lock);
1014                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1015                 c3_cpu_count--;
1016                 spin_unlock(&c3_lock);
1017         }
1018         kt2 = ktime_get_real();
1019         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
1020
1021         sleep_ticks = us_to_pm_timer_ticks(idle_time);
1022         /* Tell the scheduler how much we idled: */
1023         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1024
1025         local_irq_enable();
1026         current_thread_info()->status |= TS_POLLING;
1027
1028         cx->usage++;
1029
1030         lapic_timer_state_broadcast(pr, cx, 0);
1031         cx->time += sleep_ticks;
1032         return idle_time;
1033 }
1034
1035 struct cpuidle_driver acpi_idle_driver = {
1036         .name =         "acpi_idle",
1037         .owner =        THIS_MODULE,
1038 };
1039
1040 /**
1041  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1042  * @pr: the ACPI processor
1043  */
1044 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1045 {
1046         int i, count = CPUIDLE_DRIVER_STATE_START;
1047         struct acpi_processor_cx *cx;
1048         struct cpuidle_state *state;
1049         struct cpuidle_device *dev = &pr->power.dev;
1050
1051         if (!pr->flags.power_setup_done)
1052                 return -EINVAL;
1053
1054         if (pr->flags.power == 0) {
1055                 return -EINVAL;
1056         }
1057
1058         dev->cpu = pr->id;
1059         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1060                 dev->states[i].name[0] = '\0';
1061                 dev->states[i].desc[0] = '\0';
1062         }
1063
1064         if (max_cstate == 0)
1065                 max_cstate = 1;
1066
1067         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1068                 cx = &pr->power.states[i];
1069                 state = &dev->states[count];
1070
1071                 if (!cx->valid)
1072                         continue;
1073
1074 #ifdef CONFIG_HOTPLUG_CPU
1075                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1076                     !pr->flags.has_cst &&
1077                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1078                         continue;
1079 #endif
1080                 cpuidle_set_statedata(state, cx);
1081
1082                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1083                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1084                 state->exit_latency = cx->latency;
1085                 state->target_residency = cx->latency * latency_factor;
1086                 state->power_usage = cx->power;
1087
1088                 state->flags = 0;
1089                 switch (cx->type) {
1090                         case ACPI_STATE_C1:
1091                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1092                         if (cx->entry_method == ACPI_CSTATE_FFH)
1093                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1094
1095                         state->enter = acpi_idle_enter_c1;
1096                         dev->safe_state = state;
1097                         break;
1098
1099                         case ACPI_STATE_C2:
1100                         state->flags |= CPUIDLE_FLAG_BALANCED;
1101                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1102                         state->enter = acpi_idle_enter_simple;
1103                         dev->safe_state = state;
1104                         break;
1105
1106                         case ACPI_STATE_C3:
1107                         state->flags |= CPUIDLE_FLAG_DEEP;
1108                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1109                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1110                         state->enter = pr->flags.bm_check ?
1111                                         acpi_idle_enter_bm :
1112                                         acpi_idle_enter_simple;
1113                         break;
1114                 }
1115
1116                 count++;
1117                 if (count == CPUIDLE_STATE_MAX)
1118                         break;
1119         }
1120
1121         dev->state_count = count;
1122
1123         if (!count)
1124                 return -EINVAL;
1125
1126         return 0;
1127 }
1128
1129 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1130 {
1131         int ret = 0;
1132
1133         if (boot_option_idle_override)
1134                 return 0;
1135
1136         if (!pr)
1137                 return -EINVAL;
1138
1139         if (nocst) {
1140                 return -ENODEV;
1141         }
1142
1143         if (!pr->flags.power_setup_done)
1144                 return -ENODEV;
1145
1146         cpuidle_pause_and_lock();
1147         cpuidle_disable_device(&pr->power.dev);
1148         acpi_processor_get_power_info(pr);
1149         if (pr->flags.power) {
1150                 acpi_processor_setup_cpuidle(pr);
1151                 ret = cpuidle_enable_device(&pr->power.dev);
1152         }
1153         cpuidle_resume_and_unlock();
1154
1155         return ret;
1156 }
1157
1158 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1159                               struct acpi_device *device)
1160 {
1161         acpi_status status = 0;
1162         static int first_run;
1163         struct proc_dir_entry *entry = NULL;
1164         unsigned int i;
1165
1166         if (boot_option_idle_override)
1167                 return 0;
1168
1169         if (!first_run) {
1170                 if (idle_halt) {
1171                         /*
1172                          * When the boot option of "idle=halt" is added, halt
1173                          * is used for CPU IDLE.
1174                          * In such case C2/C3 is meaningless. So the max_cstate
1175                          * is set to one.
1176                          */
1177                         max_cstate = 1;
1178                 }
1179                 dmi_check_system(processor_power_dmi_table);
1180                 max_cstate = acpi_processor_cstate_check(max_cstate);
1181                 if (max_cstate < ACPI_C_STATES_MAX)
1182                         printk(KERN_NOTICE
1183                                "ACPI: processor limited to max C-state %d\n",
1184                                max_cstate);
1185                 first_run++;
1186         }
1187
1188         if (!pr)
1189                 return -EINVAL;
1190
1191         if (acpi_gbl_FADT.cst_control && !nocst) {
1192                 status =
1193                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1194                 if (ACPI_FAILURE(status)) {
1195                         ACPI_EXCEPTION((AE_INFO, status,
1196                                         "Notifying BIOS of _CST ability failed"));
1197                 }
1198         }
1199
1200         acpi_processor_get_power_info(pr);
1201         pr->flags.power_setup_done = 1;
1202
1203         /*
1204          * Install the idle handler if processor power management is supported.
1205          * Note that we use previously set idle handler will be used on
1206          * platforms that only support C1.
1207          */
1208         if (pr->flags.power) {
1209                 acpi_processor_setup_cpuidle(pr);
1210                 if (cpuidle_register_device(&pr->power.dev))
1211                         return -EIO;
1212
1213                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1214                 for (i = 1; i <= pr->power.count; i++)
1215                         if (pr->power.states[i].valid)
1216                                 printk(" C%d[C%d]", i,
1217                                        pr->power.states[i].type);
1218                 printk(")\n");
1219         }
1220
1221         /* 'power' [R] */
1222         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1223                                  S_IRUGO, acpi_device_dir(device),
1224                                  &acpi_processor_power_fops,
1225                                  acpi_driver_data(device));
1226         if (!entry)
1227                 return -EIO;
1228         return 0;
1229 }
1230
1231 int acpi_processor_power_exit(struct acpi_processor *pr,
1232                               struct acpi_device *device)
1233 {
1234         if (boot_option_idle_override)
1235                 return 0;
1236
1237         cpuidle_unregister_device(&pr->power.dev);
1238         pr->flags.power_setup_done = 0;
1239
1240         if (acpi_device_dir(device))
1241                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1242                                   acpi_device_dir(device));
1243
1244         return 0;
1245 }