git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/acpi.h>
  38 #include <linux/dmi.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>        /* need_resched() */
  41 #include <linux/pm_qos_params.h>
  42 #include <linux/clockchips.h>
  43 #include <linux/cpuidle.h>
  44 #include <linux/irqflags.h>
  45
  46 /*
  47  * Include the apic definitions for x86 to have the APIC timer related defines
  48  * available also for UP (on SMP it gets magically included via linux/smp.h).
  49  * asm/acpi.h is not an option, as it would require more include magic. Also
  50  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  51  */
  52 #ifdef CONFIG_X86
  53 #include <asm/apic.h>
  54 #endif
  55
  56 #include <asm/io.h>
  57 #include <asm/uaccess.h>
  58
  59 #include <acpi/acpi_bus.h>
  60 #include <acpi/processor.h>
  61 #include <asm/processor.h>
  62
  63 #define ACPI_PROCESSOR_CLASS            "processor"
  64 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  65 ACPI_MODULE_NAME("processor_idle");
  66 #define ACPI_PROCESSOR_FILE_POWER       "power"
  67 #define 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 acpi_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         /*
 152          * Check, if one of the previous states already marked the lapic
 153          * unstable
 154          */
 155         if (pwr->timer_broadcast_on_state < state)
 156                 return;
 157
 158         if (cx->type >= type)
 159                 pr->power.timer_broadcast_on_state = state;
 160 }
 161
 162 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
 163 {
 164         unsigned long reason;
 165
 166         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 167                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 168
 169         clockevents_notify(reason, &pr->id);
 170 }
 171
 172 /* Power(C) State timer broadcast control */
 173 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 174                                        struct acpi_processor_cx *cx,
 175                                        int broadcast)
 176 {
 177         int state = cx - pr->power.states;
 178
 179         if (state >= pr->power.timer_broadcast_on_state) {
 180                 unsigned long reason;
 181
 182                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 183                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 184                 clockevents_notify(reason, &pr->id);
 185         }
 186 }
 187
 188 #else
 189
 190 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 191                                    struct acpi_processor_cx *cstate) { }
 192 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
 193 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 194                                        struct acpi_processor_cx *cx,
 195                                        int broadcast)
 196 {
 197 }
 198
 199 #endif
 200
 201 /*
 202  * Suspend / resume control
 203  */
 204 static int acpi_idle_suspend;
 205 static u32 saved_bm_rld;
 206
 207 static void acpi_idle_bm_rld_save(void)
 208 {
 209         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 210 }
 211 static void acpi_idle_bm_rld_restore(void)
 212 {
 213         u32 resumed_bm_rld;
 214
 215         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 216
 217         if (resumed_bm_rld != saved_bm_rld)
 218                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 219 }
 220
 221 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 222 {
 223         if (acpi_idle_suspend == 1)
 224                 return 0;
 225
 226         acpi_idle_bm_rld_save();
 227         acpi_idle_suspend = 1;
 228         return 0;
 229 }
 230
 231 int acpi_processor_resume(struct acpi_device * device)
 232 {
 233         if (acpi_idle_suspend == 0)
 234                 return 0;
 235
 236         acpi_idle_bm_rld_restore();
 237         acpi_idle_suspend = 0;
 238         return 0;
 239 }
 240
 241 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 242 static void tsc_check_state(int state)
 243 {
 244         switch (boot_cpu_data.x86_vendor) {
 245         case X86_VENDOR_AMD:
 246         case X86_VENDOR_INTEL:
 247                 /*
 248                  * AMD Fam10h TSC will tick in all
 249                  * C/P/S0/S1 states when this bit is set.
 250                  */
 251                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 252                         return;
 253
 254                 /*FALL THROUGH*/
 255         default:
 256                 /* TSC could halt in idle, so notify users */
 257                 if (state > ACPI_STATE_C1)
 258                         mark_tsc_unstable("TSC halts in idle");
 259         }
 260 }
 261 #else
 262 static void tsc_check_state(int state) { return; }
 263 #endif
 264
 265 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 266 {
 267
 268         if (!pr)
 269                 return -EINVAL;
 270
 271         if (!pr->pblk)
 272                 return -ENODEV;
 273
 274         /* if info is obtained from pblk/fadt, type equals state */
 275         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 276         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 277
 278 #ifndef CONFIG_HOTPLUG_CPU
 279         /*
 280          * Check for P_LVL2_UP flag before entering C2 and above on
 281          * an SMP system.
 282          */
 283         if ((num_online_cpus() > 1) &&
 284             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 285                 return -ENODEV;
 286 #endif
 287
 288         /* determine C2 and C3 address from pblk */
 289         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 290         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 291
 292         /* determine latencies from FADT */
 293         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 294         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 295
 296         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 297                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 298                           pr->power.states[ACPI_STATE_C2].address,
 299                           pr->power.states[ACPI_STATE_C3].address));
 300
 301         return 0;
 302 }
 303
 304 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 305 {
 306         if (!pr->power.states[ACPI_STATE_C1].valid) {
 307                 /* set the first C-State to C1 */
 308                 /* all processors need to support C1 */
 309                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 310                 pr->power.states[ACPI_STATE_C1].valid = 1;
 311                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 312         }
 313         /* the C0 state only exists as a filler in our array */
 314         pr->power.states[ACPI_STATE_C0].valid = 1;
 315         return 0;
 316 }
 317
 318 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 319 {
 320         acpi_status status = 0;
 321         acpi_integer count;
 322         int current_count;
 323         int i;
 324         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 325         union acpi_object *cst;
 326
 327
 328         if (nocst)
 329                 return -ENODEV;
 330
 331         current_count = 0;
 332
 333         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 334         if (ACPI_FAILURE(status)) {
 335                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 336                 return -ENODEV;
 337         }
 338
 339         cst = buffer.pointer;
 340
 341         /* There must be at least 2 elements */
 342         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 343                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 344                 status = -EFAULT;
 345                 goto end;
 346         }
 347
 348         count = cst->package.elements[0].integer.value;
 349
 350         /* Validate number of power states. */
 351         if (count < 1 || count != cst->package.count - 1) {
 352                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 353                 status = -EFAULT;
 354                 goto end;
 355         }
 356
 357         /* Tell driver that at least _CST is supported. */
 358         pr->flags.has_cst = 1;
 359
 360         for (i = 1; i <= count; i++) {
 361                 union acpi_object *element;
 362                 union acpi_object *obj;
 363                 struct acpi_power_register *reg;
 364                 struct acpi_processor_cx cx;
 365
 366                 memset(&cx, 0, sizeof(cx));
 367
 368                 element = &(cst->package.elements[i]);
 369                 if (element->type != ACPI_TYPE_PACKAGE)
 370                         continue;
 371
 372                 if (element->package.count != 4)
 373                         continue;
 374
 375                 obj = &(element->package.elements[0]);
 376
 377                 if (obj->type != ACPI_TYPE_BUFFER)
 378                         continue;
 379
 380                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 381
 382                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 383                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 384                         continue;
 385
 386                 /* There should be an easy way to extract an integer... */
 387                 obj = &(element->package.elements[1]);
 388                 if (obj->type != ACPI_TYPE_INTEGER)
 389                         continue;
 390
 391                 cx.type = obj->integer.value;
 392                 /*
 393                  * Some buggy BIOSes won't list C1 in _CST -
 394                  * Let acpi_processor_get_power_info_default() handle them later
 395                  */
 396                 if (i == 1 && cx.type != ACPI_STATE_C1)
 397                         current_count++;
 398
 399                 cx.address = reg->address;
 400                 cx.index = current_count + 1;
 401
 402                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 403                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 404                         if (acpi_processor_ffh_cstate_probe
 405                                         (pr->id, &cx, reg) == 0) {
 406                                 cx.entry_method = ACPI_CSTATE_FFH;
 407                         } else if (cx.type == ACPI_STATE_C1) {
 408                                 /*
 409                                  * C1 is a special case where FIXED_HARDWARE
 410                                  * can be handled in non-MWAIT way as well.
 411                                  * In that case, save this _CST entry info.
 412                                  * Otherwise, ignore this info and continue.
 413                                  */
 414                                 cx.entry_method = ACPI_CSTATE_HALT;
 415                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 416                         } else {
 417                                 continue;
 418                         }
 419                         if (cx.type == ACPI_STATE_C1 &&
 420                                         (idle_halt || idle_nomwait)) {
 421                                 /*
 422                                  * In most cases the C1 space_id obtained from
 423                                  * _CST object is FIXED_HARDWARE access mode.
 424                                  * But when the option of idle=halt is added,
 425                                  * the entry_method type should be changed from
 426                                  * CSTATE_FFH to CSTATE_HALT.
 427                                  * When the option of idle=nomwait is added,
 428                                  * the C1 entry_method type should be
 429                                  * CSTATE_HALT.
 430                                  */
 431                                 cx.entry_method = ACPI_CSTATE_HALT;
 432                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 433                         }
 434                 } else {
 435                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 436                                  cx.address);
 437                 }
 438
 439                 if (cx.type == ACPI_STATE_C1) {
 440                         cx.valid = 1;
 441                 }
 442
 443                 obj = &(element->package.elements[2]);
 444                 if (obj->type != ACPI_TYPE_INTEGER)
 445                         continue;
 446
 447                 cx.latency = obj->integer.value;
 448
 449                 obj = &(element->package.elements[3]);
 450                 if (obj->type != ACPI_TYPE_INTEGER)
 451                         continue;
 452
 453                 cx.power = obj->integer.value;
 454
 455                 current_count++;
 456                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 457
 458                 /*
 459                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 460                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 461                  */
 462                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 463                         printk(KERN_WARNING
 464                                "Limiting number of power states to max (%d)\n",
 465                                ACPI_PROCESSOR_MAX_POWER);
 466                         printk(KERN_WARNING
 467                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 468                         break;
 469                 }
 470         }
 471
 472         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 473                           current_count));
 474
 475         /* Validate number of power states discovered */
 476         if (current_count < 2)
 477                 status = -EFAULT;
 478
 479       end:
 480         kfree(buffer.pointer);
 481
 482         return status;
 483 }
 484
 485 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 486 {
 487
 488         if (!cx->address)
 489                 return;
 490
 491         /*
 492          * C2 latency must be less than or equal to 100
 493          * microseconds.
 494          */
 495         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 496                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 497                                   "latency too large [%d]\n", cx->latency));
 498                 return;
 499         }
 500
 501         /*
 502          * Otherwise we've met all of our C2 requirements.
 503          * Normalize the C2 latency to expidite policy
 504          */
 505         cx->valid = 1;
 506
 507         cx->latency_ticks = cx->latency;
 508
 509         return;
 510 }
 511
 512 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 513                                            struct acpi_processor_cx *cx)
 514 {
 515         static int bm_check_flag;
 516
 517
 518         if (!cx->address)
 519                 return;
 520
 521         /*
 522          * C3 latency must be less than or equal to 1000
 523          * microseconds.
 524          */
 525         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 526                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 527                                   "latency too large [%d]\n", cx->latency));
 528                 return;
 529         }
 530
 531         /*
 532          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 533          * DMA transfers are used by any ISA device to avoid livelock.
 534          * Note that we could disable Type-F DMA (as recommended by
 535          * the erratum), but this is known to disrupt certain ISA
 536          * devices thus we take the conservative approach.
 537          */
 538         else if (errata.piix4.fdma) {
 539                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 540                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 541                 return;
 542         }
 543
 544         /* All the logic here assumes flags.bm_check is same across all CPUs */
 545         if (!bm_check_flag) {
 546                 /* Determine whether bm_check is needed based on CPU  */
 547                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 548                 bm_check_flag = pr->flags.bm_check;
 549         } else {
 550                 pr->flags.bm_check = bm_check_flag;
 551         }
 552
 553         if (pr->flags.bm_check) {
 554                 if (!pr->flags.bm_control) {
 555                         if (pr->flags.has_cst != 1) {
 556                                 /* bus mastering control is necessary */
 557                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 558                                         "C3 support requires BM control\n"));
 559                                 return;
 560                         } else {
 561                                 /* Here we enter C3 without bus mastering */
 562                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 563                                         "C3 support without BM control\n"));
 564                         }
 565                 }
 566         } else {
 567                 /*
 568                  * WBINVD should be set in fadt, for C3 state to be
 569                  * supported on when bm_check is not required.
 570                  */
 571                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 572                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 573                                           "Cache invalidation should work properly"
 574                                           " for C3 to be enabled on SMP systems\n"));
 575                         return;
 576                 }
 577         }
 578
 579         /*
 580          * Otherwise we've met all of our C3 requirements.
 581          * Normalize the C3 latency to expidite policy.  Enable
 582          * checking of bus mastering status (bm_check) so we can
 583          * use this in our C3 policy
 584          */
 585         cx->valid = 1;
 586
 587         cx->latency_ticks = cx->latency;
 588         /*
 589          * On older chipsets, BM_RLD needs to be set
 590          * in order for Bus Master activity to wake the
 591          * system from C3.  Newer chipsets handle DMA
 592          * during C3 automatically and BM_RLD is a NOP.
 593          * In either case, the proper way to
 594          * handle BM_RLD is to set it and leave it set.
 595          */
 596         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 597
 598         return;
 599 }
 600
 601 static int acpi_processor_power_verify(struct acpi_processor *pr)
 602 {
 603         unsigned int i;
 604         unsigned int working = 0;
 605
 606         pr->power.timer_broadcast_on_state = INT_MAX;
 607
 608         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 609                 struct acpi_processor_cx *cx = &pr->power.states[i];
 610
 611                 switch (cx->type) {
 612                 case ACPI_STATE_C1:
 613                         cx->valid = 1;
 614                         break;
 615
 616                 case ACPI_STATE_C2:
 617                         acpi_processor_power_verify_c2(cx);
 618                         if (cx->valid)
 619                                 acpi_timer_check_state(i, pr, cx);
 620                         break;
 621
 622                 case ACPI_STATE_C3:
 623                         acpi_processor_power_verify_c3(pr, cx);
 624                         if (cx->valid)
 625                                 acpi_timer_check_state(i, pr, cx);
 626                         break;
 627                 }
 628                 if (cx->valid)
 629                         tsc_check_state(cx->type);
 630
 631                 if (cx->valid)
 632                         working++;
 633         }
 634
 635         acpi_propagate_timer_broadcast(pr);
 636
 637         return (working);
 638 }
 639
 640 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 641 {
 642         unsigned int i;
 643         int result;
 644
 645
 646         /* NOTE: the idle thread may not be running while calling
 647          * this function */
 648
 649         /* Zero initialize all the C-states info. */
 650         memset(pr->power.states, 0, sizeof(pr->power.states));
 651
 652         result = acpi_processor_get_power_info_cst(pr);
 653         if (result == -ENODEV)
 654                 result = acpi_processor_get_power_info_fadt(pr);
 655
 656         if (result)
 657                 return result;
 658
 659         acpi_processor_get_power_info_default(pr);
 660
 661         pr->power.count = acpi_processor_power_verify(pr);
 662
 663         /*
 664          * if one state of type C2 or C3 is available, mark this
 665          * CPU as being "idle manageable"
 666          */
 667         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 668                 if (pr->power.states[i].valid) {
 669                         pr->power.count = i;
 670                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 671                                 pr->flags.power = 1;
 672                 }
 673         }
 674
 675         return 0;
 676 }
 677
 678 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 679 {
 680         struct acpi_processor *pr = seq->private;
 681         unsigned int i;
 682
 683
 684         if (!pr)
 685                 goto end;
 686
 687         seq_printf(seq, "active state:            C%zd\n"
 688                    "max_cstate:              C%d\n"
 689                    "maximum allowed latency: %d usec\n",
 690                    pr->power.state ? pr->power.state - pr->power.states : 0,
 691                    max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
 692
 693         seq_puts(seq, "states:\n");
 694
 695         for (i = 1; i <= pr->power.count; i++) {
 696                 seq_printf(seq, "   %cC%d:                  ",
 697                            (&pr->power.states[i] ==
 698                             pr->power.state ? '*' : ' '), i);
 699
 700                 if (!pr->power.states[i].valid) {
 701                         seq_puts(seq, "<not supported>\n");
 702                         continue;
 703                 }
 704
 705                 switch (pr->power.states[i].type) {
 706                 case ACPI_STATE_C1:
 707                         seq_printf(seq, "type[C1] ");
 708                         break;
 709                 case ACPI_STATE_C2:
 710                         seq_printf(seq, "type[C2] ");
 711                         break;
 712                 case ACPI_STATE_C3:
 713                         seq_printf(seq, "type[C3] ");
 714                         break;
 715                 default:
 716                         seq_printf(seq, "type[--] ");
 717                         break;
 718                 }
 719
 720                 if (pr->power.states[i].promotion.state)
 721                         seq_printf(seq, "promotion[C%zd] ",
 722                                    (pr->power.states[i].promotion.state -
 723                                     pr->power.states));
 724                 else
 725                         seq_puts(seq, "promotion[--] ");
 726
 727                 if (pr->power.states[i].demotion.state)
 728                         seq_printf(seq, "demotion[C%zd] ",
 729                                    (pr->power.states[i].demotion.state -
 730                                     pr->power.states));
 731                 else
 732                         seq_puts(seq, "demotion[--] ");
 733
 734                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
 735                            pr->power.states[i].latency,
 736                            pr->power.states[i].usage,
 737                            (unsigned long long)pr->power.states[i].time);
 738         }
 739
 740       end:
 741         return 0;
 742 }
 743
 744 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 745 {
 746         return single_open(file, acpi_processor_power_seq_show,
 747                            PDE(inode)->data);
 748 }
 749
 750 static const struct file_operations acpi_processor_power_fops = {
 751         .owner = THIS_MODULE,
 752         .open = acpi_processor_power_open_fs,
 753         .read = seq_read,
 754         .llseek = seq_lseek,
 755         .release = single_release,
 756 };
 757
 758
 759 /**
 760  * acpi_idle_bm_check - checks if bus master activity was detected
 761  */
 762 static int acpi_idle_bm_check(void)
 763 {
 764         u32 bm_status = 0;
 765
 766         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 767         if (bm_status)
 768                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 769         /*
 770          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 771          * the true state of bus mastering activity; forcing us to
 772          * manually check the BMIDEA bit of each IDE channel.
 773          */
 774         else if (errata.piix4.bmisx) {
 775                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 776                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 777                         bm_status = 1;
 778         }
 779         return bm_status;
 780 }
 781
 782 /**
 783  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 784  * @cx: cstate data
 785  *
 786  * Caller disables interrupt before call and enables interrupt after return.
 787  */
 788 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 789 {
 790         /* Don't trace irqs off for idle */
 791         stop_critical_timings();
 792         if (cx->entry_method == ACPI_CSTATE_FFH) {
 793                 /* Call into architectural FFH based C-state */
 794                 acpi_processor_ffh_cstate_enter(cx);
 795         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 796                 acpi_safe_halt();
 797         } else {
 798                 int unused;
 799                 /* IO port based C-state */
 800                 inb(cx->address);
 801                 /* Dummy wait op - must do something useless after P_LVL2 read
 802                    because chipsets cannot guarantee that STPCLK# signal
 803                    gets asserted in time to freeze execution properly. */
 804                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 805         }
 806         start_critical_timings();
 807 }
 808
 809 /**
 810  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 811  * @dev: the target CPU
 812  * @state: the state data
 813  *
 814  * This is equivalent to the HALT instruction.
 815  */
 816 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 817                               struct cpuidle_state *state)
 818 {
 819         ktime_t  kt1, kt2;
 820         s64 idle_time;
 821         struct acpi_processor *pr;
 822         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 823
 824         pr = __get_cpu_var(processors);
 825
 826         if (unlikely(!pr))
 827                 return 0;
 828
 829         local_irq_disable();
 830
 831         /* Do not access any ACPI IO ports in suspend path */
 832         if (acpi_idle_suspend) {
 833                 acpi_safe_halt();
 834                 local_irq_enable();
 835                 return 0;
 836         }
 837
 838         kt1 = ktime_get_real();
 839         acpi_idle_do_entry(cx);
 840         kt2 = ktime_get_real();
 841         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 842
 843         local_irq_enable();
 844         cx->usage++;
 845
 846         return idle_time;
 847 }
 848
 849 /**
 850  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 851  * @dev: the target CPU
 852  * @state: the state data
 853  */
 854 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 855                                   struct cpuidle_state *state)
 856 {
 857         struct acpi_processor *pr;
 858         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 859         ktime_t  kt1, kt2;
 860         s64 idle_time;
 861         s64 sleep_ticks = 0;
 862
 863         pr = __get_cpu_var(processors);
 864
 865         if (unlikely(!pr))
 866                 return 0;
 867
 868         if (acpi_idle_suspend)
 869                 return(acpi_idle_enter_c1(dev, state));
 870
 871         local_irq_disable();
 872         current_thread_info()->status &= ~TS_POLLING;
 873         /*
 874          * TS_POLLING-cleared state must be visible before we test
 875          * NEED_RESCHED:
 876          */
 877         smp_mb();
 878
 879         if (unlikely(need_resched())) {
 880                 current_thread_info()->status |= TS_POLLING;
 881                 local_irq_enable();
 882                 return 0;
 883         }
 884
 885         /*
 886          * Must be done before busmaster disable as we might need to
 887          * access HPET !
 888          */
 889         acpi_state_timer_broadcast(pr, cx, 1);
 890
 891         if (cx->type == ACPI_STATE_C3)
 892                 ACPI_FLUSH_CPU_CACHE();
 893
 894         kt1 = ktime_get_real();
 895         /* Tell the scheduler that we are going deep-idle: */
 896         sched_clock_idle_sleep_event();
 897         acpi_idle_do_entry(cx);
 898         kt2 = ktime_get_real();
 899         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 900
 901         sleep_ticks = us_to_pm_timer_ticks(idle_time);
 902
 903         /* Tell the scheduler how much we idled: */
 904         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 905
 906         local_irq_enable();
 907         current_thread_info()->status |= TS_POLLING;
 908
 909         cx->usage++;
 910
 911         acpi_state_timer_broadcast(pr, cx, 0);
 912         cx->time += sleep_ticks;
 913         return idle_time;
 914 }
 915
 916 static int c3_cpu_count;
 917 static DEFINE_SPINLOCK(c3_lock);
 918
 919 /**
 920  * acpi_idle_enter_bm - enters C3 with proper BM handling
 921  * @dev: the target CPU
 922  * @state: the state data
 923  *
 924  * If BM is detected, the deepest non-C3 idle state is entered instead.
 925  */
 926 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 927                               struct cpuidle_state *state)
 928 {
 929         struct acpi_processor *pr;
 930         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 931         ktime_t  kt1, kt2;
 932         s64 idle_time;
 933         s64 sleep_ticks = 0;
 934
 935
 936         pr = __get_cpu_var(processors);
 937
 938         if (unlikely(!pr))
 939                 return 0;
 940
 941         if (acpi_idle_suspend)
 942                 return(acpi_idle_enter_c1(dev, state));
 943
 944         if (acpi_idle_bm_check()) {
 945                 if (dev->safe_state) {
 946                         dev->last_state = dev->safe_state;
 947                         return dev->safe_state->enter(dev, dev->safe_state);
 948                 } else {
 949                         local_irq_disable();
 950                         acpi_safe_halt();
 951                         local_irq_enable();
 952                         return 0;
 953                 }
 954         }
 955
 956         local_irq_disable();
 957         current_thread_info()->status &= ~TS_POLLING;
 958         /*
 959          * TS_POLLING-cleared state must be visible before we test
 960          * NEED_RESCHED:
 961          */
 962         smp_mb();
 963
 964         if (unlikely(need_resched())) {
 965                 current_thread_info()->status |= TS_POLLING;
 966                 local_irq_enable();
 967                 return 0;
 968         }
 969
 970         acpi_unlazy_tlb(smp_processor_id());
 971
 972         /* Tell the scheduler that we are going deep-idle: */
 973         sched_clock_idle_sleep_event();
 974         /*
 975          * Must be done before busmaster disable as we might need to
 976          * access HPET !
 977          */
 978         acpi_state_timer_broadcast(pr, cx, 1);
 979
 980         kt1 = ktime_get_real();
 981         /*
 982          * disable bus master
 983          * bm_check implies we need ARB_DIS
 984          * !bm_check implies we need cache flush
 985          * bm_control implies whether we can do ARB_DIS
 986          *
 987          * That leaves a case where bm_check is set and bm_control is
 988          * not set. In that case we cannot do much, we enter C3
 989          * without doing anything.
 990          */
 991         if (pr->flags.bm_check && pr->flags.bm_control) {
 992                 spin_lock(&c3_lock);
 993                 c3_cpu_count++;
 994                 /* Disable bus master arbitration when all CPUs are in C3 */
 995                 if (c3_cpu_count == num_online_cpus())
 996                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 997                 spin_unlock(&c3_lock);
 998         } else if (!pr->flags.bm_check) {
 999                 ACPI_FLUSH_CPU_CACHE();
1000         }
1001
1002         acpi_idle_do_entry(cx);
1003
1004         /* Re-enable bus master arbitration */
1005         if (pr->flags.bm_check && pr->flags.bm_control) {
1006                 spin_lock(&c3_lock);
1007                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1008                 c3_cpu_count--;
1009                 spin_unlock(&c3_lock);
1010         }
1011         kt2 = ktime_get_real();
1012         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
1013
1014         sleep_ticks = us_to_pm_timer_ticks(idle_time);
1015         /* Tell the scheduler how much we idled: */
1016         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1017
1018         local_irq_enable();
1019         current_thread_info()->status |= TS_POLLING;
1020
1021         cx->usage++;
1022
1023         acpi_state_timer_broadcast(pr, cx, 0);
1024         cx->time += sleep_ticks;
1025         return idle_time;
1026 }
1027
1028 struct cpuidle_driver acpi_idle_driver = {
1029         .name =         "acpi_idle",
1030         .owner =        THIS_MODULE,
1031 };
1032
1033 /**
1034  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1035  * @pr: the ACPI processor
1036  */
1037 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1038 {
1039         int i, count = CPUIDLE_DRIVER_STATE_START;
1040         struct acpi_processor_cx *cx;
1041         struct cpuidle_state *state;
1042         struct cpuidle_device *dev = &pr->power.dev;
1043
1044         if (!pr->flags.power_setup_done)
1045                 return -EINVAL;
1046
1047         if (pr->flags.power == 0) {
1048                 return -EINVAL;
1049         }
1050
1051         dev->cpu = pr->id;
1052         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1053                 dev->states[i].name[0] = '\0';
1054                 dev->states[i].desc[0] = '\0';
1055         }
1056
1057         if (max_cstate == 0)
1058                 max_cstate = 1;
1059
1060         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1061                 cx = &pr->power.states[i];
1062                 state = &dev->states[count];
1063
1064                 if (!cx->valid)
1065                         continue;
1066
1067 #ifdef CONFIG_HOTPLUG_CPU
1068                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1069                     !pr->flags.has_cst &&
1070                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1071                         continue;
1072 #endif
1073                 cpuidle_set_statedata(state, cx);
1074
1075                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1076                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1077                 state->exit_latency = cx->latency;
1078                 state->target_residency = cx->latency * latency_factor;
1079                 state->power_usage = cx->power;
1080
1081                 state->flags = 0;
1082                 switch (cx->type) {
1083                         case ACPI_STATE_C1:
1084                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1085                         if (cx->entry_method == ACPI_CSTATE_FFH)
1086                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1087
1088                         state->enter = acpi_idle_enter_c1;
1089                         dev->safe_state = state;
1090                         break;
1091
1092                         case ACPI_STATE_C2:
1093                         state->flags |= CPUIDLE_FLAG_BALANCED;
1094                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1095                         state->enter = acpi_idle_enter_simple;
1096                         dev->safe_state = state;
1097                         break;
1098
1099                         case ACPI_STATE_C3:
1100                         state->flags |= CPUIDLE_FLAG_DEEP;
1101                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1102                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1103                         state->enter = pr->flags.bm_check ?
1104                                         acpi_idle_enter_bm :
1105                                         acpi_idle_enter_simple;
1106                         break;
1107                 }
1108
1109                 count++;
1110                 if (count == CPUIDLE_STATE_MAX)
1111                         break;
1112         }
1113
1114         dev->state_count = count;
1115
1116         if (!count)
1117                 return -EINVAL;
1118
1119         return 0;
1120 }
1121
1122 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1123 {
1124         int ret = 0;
1125
1126         if (boot_option_idle_override)
1127                 return 0;
1128
1129         if (!pr)
1130                 return -EINVAL;
1131
1132         if (nocst) {
1133                 return -ENODEV;
1134         }
1135
1136         if (!pr->flags.power_setup_done)
1137                 return -ENODEV;
1138
1139         cpuidle_pause_and_lock();
1140         cpuidle_disable_device(&pr->power.dev);
1141         acpi_processor_get_power_info(pr);
1142         if (pr->flags.power) {
1143                 acpi_processor_setup_cpuidle(pr);
1144                 ret = cpuidle_enable_device(&pr->power.dev);
1145         }
1146         cpuidle_resume_and_unlock();
1147
1148         return ret;
1149 }
1150
1151 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1152                               struct acpi_device *device)
1153 {
1154         acpi_status status = 0;
1155         static int first_run;
1156         struct proc_dir_entry *entry = NULL;
1157         unsigned int i;
1158
1159         if (boot_option_idle_override)
1160                 return 0;
1161
1162         if (!first_run) {
1163                 if (idle_halt) {
1164                         /*
1165                          * When the boot option of "idle=halt" is added, halt
1166                          * is used for CPU IDLE.
1167                          * In such case C2/C3 is meaningless. So the max_cstate
1168                          * is set to one.
1169                          */
1170                         max_cstate = 1;
1171                 }
1172                 dmi_check_system(processor_power_dmi_table);
1173                 max_cstate = acpi_processor_cstate_check(max_cstate);
1174                 if (max_cstate < ACPI_C_STATES_MAX)
1175                         printk(KERN_NOTICE
1176                                "ACPI: processor limited to max C-state %d\n",
1177                                max_cstate);
1178                 first_run++;
1179         }
1180
1181         if (!pr)
1182                 return -EINVAL;
1183
1184         if (acpi_gbl_FADT.cst_control && !nocst) {
1185                 status =
1186                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1187                 if (ACPI_FAILURE(status)) {
1188                         ACPI_EXCEPTION((AE_INFO, status,
1189                                         "Notifying BIOS of _CST ability failed"));
1190                 }
1191         }
1192
1193         acpi_processor_get_power_info(pr);
1194         pr->flags.power_setup_done = 1;
1195
1196         /*
1197          * Install the idle handler if processor power management is supported.
1198          * Note that we use previously set idle handler will be used on
1199          * platforms that only support C1.
1200          */
1201         if (pr->flags.power) {
1202                 acpi_processor_setup_cpuidle(pr);
1203                 if (cpuidle_register_device(&pr->power.dev))
1204                         return -EIO;
1205
1206                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1207                 for (i = 1; i <= pr->power.count; i++)
1208                         if (pr->power.states[i].valid)
1209                                 printk(" C%d[C%d]", i,
1210                                        pr->power.states[i].type);
1211                 printk(")\n");
1212         }
1213
1214         /* 'power' [R] */
1215         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1216                                  S_IRUGO, acpi_device_dir(device),
1217                                  &acpi_processor_power_fops,
1218                                  acpi_driver_data(device));
1219         if (!entry)
1220                 return -EIO;
1221         return 0;
1222 }
1223
1224 int acpi_processor_power_exit(struct acpi_processor *pr,
1225                               struct acpi_device *device)
1226 {
1227         if (boot_option_idle_override)
1228                 return 0;
1229
1230         cpuidle_unregister_device(&pr->power.dev);
1231         pr->flags.power_setup_done = 0;
1232
1233         if (acpi_device_dir(device))
1234                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1235                                   acpi_device_dir(device));
1236
1237         return 0;
1238 }