linux/drivers/acpi/processor_idle.c
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   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/module.h>
  32#include <linux/acpi.h>
  33#include <linux/dmi.h>
  34#include <linux/sched.h>       /* need_resched() */
  35#include <linux/clockchips.h>
  36#include <linux/cpuidle.h>
  37
  38/*
  39 * Include the apic definitions for x86 to have the APIC timer related defines
  40 * available also for UP (on SMP it gets magically included via linux/smp.h).
  41 * asm/acpi.h is not an option, as it would require more include magic. Also
  42 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  43 */
  44#ifdef CONFIG_X86
  45#include <asm/apic.h>
  46#endif
  47
  48#include <acpi/acpi_bus.h>
  49#include <acpi/processor.h>
  50
  51#define PREFIX "ACPI: "
  52
  53#define ACPI_PROCESSOR_CLASS            "processor"
  54#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  55ACPI_MODULE_NAME("processor_idle");
  56
  57static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  58module_param(max_cstate, uint, 0000);
  59static unsigned int nocst __read_mostly;
  60module_param(nocst, uint, 0000);
  61static int bm_check_disable __read_mostly;
  62module_param(bm_check_disable, uint, 0000);
  63
  64static unsigned int latency_factor __read_mostly = 2;
  65module_param(latency_factor, uint, 0644);
  66
  67static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  68
  69static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
  70                                                                acpi_cstate);
  71
  72static int disabled_by_idle_boot_param(void)
  73{
  74        return boot_option_idle_override == IDLE_POLL ||
  75                boot_option_idle_override == IDLE_HALT;
  76}
  77
  78/*
  79 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  80 * For now disable this. Probably a bug somewhere else.
  81 *
  82 * To skip this limit, boot/load with a large max_cstate limit.
  83 */
  84static int set_max_cstate(const struct dmi_system_id *id)
  85{
  86        if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  87                return 0;
  88
  89        printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  90               " Override with \"processor.max_cstate=%d\"\n", id->ident,
  91               (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  92
  93        max_cstate = (long)id->driver_data;
  94
  95        return 0;
  96}
  97
  98/* Actually this shouldn't be __cpuinitdata, would be better to fix the
  99   callers to only run once -AK */
 100static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 101        { set_max_cstate, "Clevo 5600D", {
 102          DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 103          DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 104         (void *)2},
 105        { set_max_cstate, "Pavilion zv5000", {
 106          DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 107          DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 108         (void *)1},
 109        { set_max_cstate, "Asus L8400B", {
 110          DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 111          DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 112         (void *)1},
 113        {},
 114};
 115
 116
 117/*
 118 * Callers should disable interrupts before the call and enable
 119 * interrupts after return.
 120 */
 121static void acpi_safe_halt(void)
 122{
 123        current_thread_info()->status &= ~TS_POLLING;
 124        /*
 125         * TS_POLLING-cleared state must be visible before we
 126         * test NEED_RESCHED:
 127         */
 128        smp_mb();
 129        if (!need_resched()) {
 130                safe_halt();
 131                local_irq_disable();
 132        }
 133        current_thread_info()->status |= TS_POLLING;
 134}
 135
 136#ifdef ARCH_APICTIMER_STOPS_ON_C3
 137
 138/*
 139 * Some BIOS implementations switch to C3 in the published C2 state.
 140 * This seems to be a common problem on AMD boxen, but other vendors
 141 * are affected too. We pick the most conservative approach: we assume
 142 * that the local APIC stops in both C2 and C3.
 143 */
 144static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 145                                   struct acpi_processor_cx *cx)
 146{
 147        struct acpi_processor_power *pwr = &pr->power;
 148        u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 149
 150        if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 151                return;
 152
 153        if (amd_e400_c1e_detected)
 154                type = ACPI_STATE_C1;
 155
 156        /*
 157         * Check, if one of the previous states already marked the lapic
 158         * unstable
 159         */
 160        if (pwr->timer_broadcast_on_state < state)
 161                return;
 162
 163        if (cx->type >= type)
 164                pr->power.timer_broadcast_on_state = state;
 165}
 166
 167static void __lapic_timer_propagate_broadcast(void *arg)
 168{
 169        struct acpi_processor *pr = (struct acpi_processor *) arg;
 170        unsigned long reason;
 171
 172        reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 173                CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 174
 175        clockevents_notify(reason, &pr->id);
 176}
 177
 178static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 179{
 180        smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 181                                 (void *)pr, 1);
 182}
 183
 184/* Power(C) State timer broadcast control */
 185static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 186                                       struct acpi_processor_cx *cx,
 187                                       int broadcast)
 188{
 189        int state = cx - pr->power.states;
 190
 191        if (state >= pr->power.timer_broadcast_on_state) {
 192                unsigned long reason;
 193
 194                reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 195                        CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 196                clockevents_notify(reason, &pr->id);
 197        }
 198}
 199
 200#else
 201
 202static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 203                                   struct acpi_processor_cx *cstate) { }
 204static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 205static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 206                                       struct acpi_processor_cx *cx,
 207                                       int broadcast)
 208{
 209}
 210
 211#endif
 212
 213static u32 saved_bm_rld;
 214
 215static void acpi_idle_bm_rld_save(void)
 216{
 217        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 218}
 219static void acpi_idle_bm_rld_restore(void)
 220{
 221        u32 resumed_bm_rld;
 222
 223        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 224
 225        if (resumed_bm_rld != saved_bm_rld)
 226                acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 227}
 228
 229int acpi_processor_suspend(struct device *dev)
 230{
 231        acpi_idle_bm_rld_save();
 232        return 0;
 233}
 234
 235int acpi_processor_resume(struct device *dev)
 236{
 237        acpi_idle_bm_rld_restore();
 238        return 0;
 239}
 240
 241#if defined(CONFIG_X86)
 242static 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
 262static void tsc_check_state(int state) { return; }
 263#endif
 264
 265static 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.c2_latency;
 294        pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 295
 296        /*
 297         * FADT specified C2 latency must be less than or equal to
 298         * 100 microseconds.
 299         */
 300        if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 301                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 302                        "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 303                /* invalidate C2 */
 304                pr->power.states[ACPI_STATE_C2].address = 0;
 305        }
 306
 307        /*
 308         * FADT supplied C3 latency must be less than or equal to
 309         * 1000 microseconds.
 310         */
 311        if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 312                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 313                        "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 314                /* invalidate C3 */
 315                pr->power.states[ACPI_STATE_C3].address = 0;
 316        }
 317
 318        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 319                          "lvl2[0x%08x] lvl3[0x%08x]\n",
 320                          pr->power.states[ACPI_STATE_C2].address,
 321                          pr->power.states[ACPI_STATE_C3].address));
 322
 323        return 0;
 324}
 325
 326static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 327{
 328        if (!pr->power.states[ACPI_STATE_C1].valid) {
 329                /* set the first C-State to C1 */
 330                /* all processors need to support C1 */
 331                pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 332                pr->power.states[ACPI_STATE_C1].valid = 1;
 333                pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 334        }
 335        /* the C0 state only exists as a filler in our array */
 336        pr->power.states[ACPI_STATE_C0].valid = 1;
 337        return 0;
 338}
 339
 340static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 341{
 342        acpi_status status = 0;
 343        u64 count;
 344        int current_count;
 345        int i;
 346        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 347        union acpi_object *cst;
 348
 349
 350        if (nocst)
 351                return -ENODEV;
 352
 353        current_count = 0;
 354
 355        status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 356        if (ACPI_FAILURE(status)) {
 357                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 358                return -ENODEV;
 359        }
 360
 361        cst = buffer.pointer;
 362
 363        /* There must be at least 2 elements */
 364        if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 365                printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 366                status = -EFAULT;
 367                goto end;
 368        }
 369
 370        count = cst->package.elements[0].integer.value;
 371
 372        /* Validate number of power states. */
 373        if (count < 1 || count != cst->package.count - 1) {
 374                printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 375                status = -EFAULT;
 376                goto end;
 377        }
 378
 379        /* Tell driver that at least _CST is supported. */
 380        pr->flags.has_cst = 1;
 381
 382        for (i = 1; i <= count; i++) {
 383                union acpi_object *element;
 384                union acpi_object *obj;
 385                struct acpi_power_register *reg;
 386                struct acpi_processor_cx cx;
 387
 388                memset(&cx, 0, sizeof(cx));
 389
 390                element = &(cst->package.elements[i]);
 391                if (element->type != ACPI_TYPE_PACKAGE)
 392                        continue;
 393
 394                if (element->package.count != 4)
 395                        continue;
 396
 397                obj = &(element->package.elements[0]);
 398
 399                if (obj->type != ACPI_TYPE_BUFFER)
 400                        continue;
 401
 402                reg = (struct acpi_power_register *)obj->buffer.pointer;
 403
 404                if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 405                    (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 406                        continue;
 407
 408                /* There should be an easy way to extract an integer... */
 409                obj = &(element->package.elements[1]);
 410                if (obj->type != ACPI_TYPE_INTEGER)
 411                        continue;
 412
 413                cx.type = obj->integer.value;
 414                /*
 415                 * Some buggy BIOSes won't list C1 in _CST -
 416                 * Let acpi_processor_get_power_info_default() handle them later
 417                 */
 418                if (i == 1 && cx.type != ACPI_STATE_C1)
 419                        current_count++;
 420
 421                cx.address = reg->address;
 422                cx.index = current_count + 1;
 423
 424                cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 425                if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 426                        if (acpi_processor_ffh_cstate_probe
 427                                        (pr->id, &cx, reg) == 0) {
 428                                cx.entry_method = ACPI_CSTATE_FFH;
 429                        } else if (cx.type == ACPI_STATE_C1) {
 430                                /*
 431                                 * C1 is a special case where FIXED_HARDWARE
 432                                 * can be handled in non-MWAIT way as well.
 433                                 * In that case, save this _CST entry info.
 434                                 * Otherwise, ignore this info and continue.
 435                                 */
 436                                cx.entry_method = ACPI_CSTATE_HALT;
 437                                snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 438                        } else {
 439                                continue;
 440                        }
 441                        if (cx.type == ACPI_STATE_C1 &&
 442                            (boot_option_idle_override == IDLE_NOMWAIT)) {
 443                                /*
 444                                 * In most cases the C1 space_id obtained from
 445                                 * _CST object is FIXED_HARDWARE access mode.
 446                                 * But when the option of idle=halt is added,
 447                                 * the entry_method type should be changed from
 448                                 * CSTATE_FFH to CSTATE_HALT.
 449                                 * When the option of idle=nomwait is added,
 450                                 * the C1 entry_method type should be
 451                                 * CSTATE_HALT.
 452                                 */
 453                                cx.entry_method = ACPI_CSTATE_HALT;
 454                                snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 455                        }
 456                } else {
 457                        snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 458                                 cx.address);
 459                }
 460
 461                if (cx.type == ACPI_STATE_C1) {
 462                        cx.valid = 1;
 463                }
 464
 465                obj = &(element->package.elements[2]);
 466                if (obj->type != ACPI_TYPE_INTEGER)
 467                        continue;
 468
 469                cx.latency = obj->integer.value;
 470
 471                obj = &(element->package.elements[3]);
 472                if (obj->type != ACPI_TYPE_INTEGER)
 473                        continue;
 474
 475                current_count++;
 476                memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 477
 478                /*
 479                 * We support total ACPI_PROCESSOR_MAX_POWER - 1
 480                 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 481                 */
 482                if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 483                        printk(KERN_WARNING
 484                               "Limiting number of power states to max (%d)\n",
 485                               ACPI_PROCESSOR_MAX_POWER);
 486                        printk(KERN_WARNING
 487                               "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 488                        break;
 489                }
 490        }
 491
 492        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 493                          current_count));
 494
 495        /* Validate number of power states discovered */
 496        if (current_count < 2)
 497                status = -EFAULT;
 498
 499      end:
 500        kfree(buffer.pointer);
 501
 502        return status;
 503}
 504
 505static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 506                                           struct acpi_processor_cx *cx)
 507{
 508        static int bm_check_flag = -1;
 509        static int bm_control_flag = -1;
 510
 511
 512        if (!cx->address)
 513                return;
 514
 515        /*
 516         * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 517         * DMA transfers are used by any ISA device to avoid livelock.
 518         * Note that we could disable Type-F DMA (as recommended by
 519         * the erratum), but this is known to disrupt certain ISA
 520         * devices thus we take the conservative approach.
 521         */
 522        else if (errata.piix4.fdma) {
 523                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 524                                  "C3 not supported on PIIX4 with Type-F DMA\n"));
 525                return;
 526        }
 527
 528        /* All the logic here assumes flags.bm_check is same across all CPUs */
 529        if (bm_check_flag == -1) {
 530                /* Determine whether bm_check is needed based on CPU  */
 531                acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 532                bm_check_flag = pr->flags.bm_check;
 533                bm_control_flag = pr->flags.bm_control;
 534        } else {
 535                pr->flags.bm_check = bm_check_flag;
 536                pr->flags.bm_control = bm_control_flag;
 537        }
 538
 539        if (pr->flags.bm_check) {
 540                if (!pr->flags.bm_control) {
 541                        if (pr->flags.has_cst != 1) {
 542                                /* bus mastering control is necessary */
 543                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 544                                        "C3 support requires BM control\n"));
 545                                return;
 546                        } else {
 547                                /* Here we enter C3 without bus mastering */
 548                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 549                                        "C3 support without BM control\n"));
 550                        }
 551                }
 552        } else {
 553                /*
 554                 * WBINVD should be set in fadt, for C3 state to be
 555                 * supported on when bm_check is not required.
 556                 */
 557                if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 558                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 559                                          "Cache invalidation should work properly"
 560                                          " for C3 to be enabled on SMP systems\n"));
 561                        return;
 562                }
 563        }
 564
 565        /*
 566         * Otherwise we've met all of our C3 requirements.
 567         * Normalize the C3 latency to expidite policy.  Enable
 568         * checking of bus mastering status (bm_check) so we can
 569         * use this in our C3 policy
 570         */
 571        cx->valid = 1;
 572
 573        /*
 574         * On older chipsets, BM_RLD needs to be set
 575         * in order for Bus Master activity to wake the
 576         * system from C3.  Newer chipsets handle DMA
 577         * during C3 automatically and BM_RLD is a NOP.
 578         * In either case, the proper way to
 579         * handle BM_RLD is to set it and leave it set.
 580         */
 581        acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 582
 583        return;
 584}
 585
 586static int acpi_processor_power_verify(struct acpi_processor *pr)
 587{
 588        unsigned int i;
 589        unsigned int working = 0;
 590
 591        pr->power.timer_broadcast_on_state = INT_MAX;
 592
 593        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 594                struct acpi_processor_cx *cx = &pr->power.states[i];
 595
 596                switch (cx->type) {
 597                case ACPI_STATE_C1:
 598                        cx->valid = 1;
 599                        break;
 600
 601                case ACPI_STATE_C2:
 602                        if (!cx->address)
 603                                break;
 604                        cx->valid = 1; 
 605                        break;
 606
 607                case ACPI_STATE_C3:
 608                        acpi_processor_power_verify_c3(pr, cx);
 609                        break;
 610                }
 611                if (!cx->valid)
 612                        continue;
 613
 614                lapic_timer_check_state(i, pr, cx);
 615                tsc_check_state(cx->type);
 616                working++;
 617        }
 618
 619        lapic_timer_propagate_broadcast(pr);
 620
 621        return (working);
 622}
 623
 624static int acpi_processor_get_power_info(struct acpi_processor *pr)
 625{
 626        unsigned int i;
 627        int result;
 628
 629
 630        /* NOTE: the idle thread may not be running while calling
 631         * this function */
 632
 633        /* Zero initialize all the C-states info. */
 634        memset(pr->power.states, 0, sizeof(pr->power.states));
 635
 636        result = acpi_processor_get_power_info_cst(pr);
 637        if (result == -ENODEV)
 638                result = acpi_processor_get_power_info_fadt(pr);
 639
 640        if (result)
 641                return result;
 642
 643        acpi_processor_get_power_info_default(pr);
 644
 645        pr->power.count = acpi_processor_power_verify(pr);
 646
 647        /*
 648         * if one state of type C2 or C3 is available, mark this
 649         * CPU as being "idle manageable"
 650         */
 651        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 652                if (pr->power.states[i].valid) {
 653                        pr->power.count = i;
 654                        if (pr->power.states[i].type >= ACPI_STATE_C2)
 655                                pr->flags.power = 1;
 656                }
 657        }
 658
 659        return 0;
 660}
 661
 662/**
 663 * acpi_idle_bm_check - checks if bus master activity was detected
 664 */
 665static int acpi_idle_bm_check(void)
 666{
 667        u32 bm_status = 0;
 668
 669        if (bm_check_disable)
 670                return 0;
 671
 672        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 673        if (bm_status)
 674                acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 675        /*
 676         * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 677         * the true state of bus mastering activity; forcing us to
 678         * manually check the BMIDEA bit of each IDE channel.
 679         */
 680        else if (errata.piix4.bmisx) {
 681                if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 682                    || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 683                        bm_status = 1;
 684        }
 685        return bm_status;
 686}
 687
 688/**
 689 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 690 * @cx: cstate data
 691 *
 692 * Caller disables interrupt before call and enables interrupt after return.
 693 */
 694static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 695{
 696        /* Don't trace irqs off for idle */
 697        stop_critical_timings();
 698        if (cx->entry_method == ACPI_CSTATE_FFH) {
 699                /* Call into architectural FFH based C-state */
 700                acpi_processor_ffh_cstate_enter(cx);
 701        } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 702                acpi_safe_halt();
 703        } else {
 704                /* IO port based C-state */
 705                inb(cx->address);
 706                /* Dummy wait op - must do something useless after P_LVL2 read
 707                   because chipsets cannot guarantee that STPCLK# signal
 708                   gets asserted in time to freeze execution properly. */
 709                inl(acpi_gbl_FADT.xpm_timer_block.address);
 710        }
 711        start_critical_timings();
 712}
 713
 714/**
 715 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 716 * @dev: the target CPU
 717 * @drv: cpuidle driver containing cpuidle state info
 718 * @index: index of target state
 719 *
 720 * This is equivalent to the HALT instruction.
 721 */
 722static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 723                struct cpuidle_driver *drv, int index)
 724{
 725        struct acpi_processor *pr;
 726        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 727
 728        pr = __this_cpu_read(processors);
 729
 730        if (unlikely(!pr))
 731                return -EINVAL;
 732
 733        lapic_timer_state_broadcast(pr, cx, 1);
 734        acpi_idle_do_entry(cx);
 735
 736        lapic_timer_state_broadcast(pr, cx, 0);
 737
 738        return index;
 739}
 740
 741
 742/**
 743 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 744 * @dev: the target CPU
 745 * @index: the index of suggested state
 746 */
 747static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 748{
 749        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 750
 751        ACPI_FLUSH_CPU_CACHE();
 752
 753        while (1) {
 754
 755                if (cx->entry_method == ACPI_CSTATE_HALT)
 756                        safe_halt();
 757                else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 758                        inb(cx->address);
 759                        /* See comment in acpi_idle_do_entry() */
 760                        inl(acpi_gbl_FADT.xpm_timer_block.address);
 761                } else
 762                        return -ENODEV;
 763        }
 764
 765        /* Never reached */
 766        return 0;
 767}
 768
 769/**
 770 * acpi_idle_enter_simple - enters an ACPI state without BM handling
 771 * @dev: the target CPU
 772 * @drv: cpuidle driver with cpuidle state information
 773 * @index: the index of suggested state
 774 */
 775static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 776                struct cpuidle_driver *drv, int index)
 777{
 778        struct acpi_processor *pr;
 779        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 780
 781        pr = __this_cpu_read(processors);
 782
 783        if (unlikely(!pr))
 784                return -EINVAL;
 785
 786        if (cx->entry_method != ACPI_CSTATE_FFH) {
 787                current_thread_info()->status &= ~TS_POLLING;
 788                /*
 789                 * TS_POLLING-cleared state must be visible before we test
 790                 * NEED_RESCHED:
 791                 */
 792                smp_mb();
 793
 794                if (unlikely(need_resched())) {
 795                        current_thread_info()->status |= TS_POLLING;
 796                        return -EINVAL;
 797                }
 798        }
 799
 800        /*
 801         * Must be done before busmaster disable as we might need to
 802         * access HPET !
 803         */
 804        lapic_timer_state_broadcast(pr, cx, 1);
 805
 806        if (cx->type == ACPI_STATE_C3)
 807                ACPI_FLUSH_CPU_CACHE();
 808
 809        /* Tell the scheduler that we are going deep-idle: */
 810        sched_clock_idle_sleep_event();
 811        acpi_idle_do_entry(cx);
 812
 813        sched_clock_idle_wakeup_event(0);
 814
 815        if (cx->entry_method != ACPI_CSTATE_FFH)
 816                current_thread_info()->status |= TS_POLLING;
 817
 818        lapic_timer_state_broadcast(pr, cx, 0);
 819        return index;
 820}
 821
 822static int c3_cpu_count;
 823static DEFINE_RAW_SPINLOCK(c3_lock);
 824
 825/**
 826 * acpi_idle_enter_bm - enters C3 with proper BM handling
 827 * @dev: the target CPU
 828 * @drv: cpuidle driver containing state data
 829 * @index: the index of suggested state
 830 *
 831 * If BM is detected, the deepest non-C3 idle state is entered instead.
 832 */
 833static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 834                struct cpuidle_driver *drv, int index)
 835{
 836        struct acpi_processor *pr;
 837        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 838
 839        pr = __this_cpu_read(processors);
 840
 841        if (unlikely(!pr))
 842                return -EINVAL;
 843
 844        if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 845                if (drv->safe_state_index >= 0) {
 846                        return drv->states[drv->safe_state_index].enter(dev,
 847                                                drv, drv->safe_state_index);
 848                } else {
 849                        acpi_safe_halt();
 850                        return -EBUSY;
 851                }
 852        }
 853
 854        if (cx->entry_method != ACPI_CSTATE_FFH) {
 855                current_thread_info()->status &= ~TS_POLLING;
 856                /*
 857                 * TS_POLLING-cleared state must be visible before we test
 858                 * NEED_RESCHED:
 859                 */
 860                smp_mb();
 861
 862                if (unlikely(need_resched())) {
 863                        current_thread_info()->status |= TS_POLLING;
 864                        return -EINVAL;
 865                }
 866        }
 867
 868        acpi_unlazy_tlb(smp_processor_id());
 869
 870        /* Tell the scheduler that we are going deep-idle: */
 871        sched_clock_idle_sleep_event();
 872        /*
 873         * Must be done before busmaster disable as we might need to
 874         * access HPET !
 875         */
 876        lapic_timer_state_broadcast(pr, cx, 1);
 877
 878        /*
 879         * disable bus master
 880         * bm_check implies we need ARB_DIS
 881         * !bm_check implies we need cache flush
 882         * bm_control implies whether we can do ARB_DIS
 883         *
 884         * That leaves a case where bm_check is set and bm_control is
 885         * not set. In that case we cannot do much, we enter C3
 886         * without doing anything.
 887         */
 888        if (pr->flags.bm_check && pr->flags.bm_control) {
 889                raw_spin_lock(&c3_lock);
 890                c3_cpu_count++;
 891                /* Disable bus master arbitration when all CPUs are in C3 */
 892                if (c3_cpu_count == num_online_cpus())
 893                        acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 894                raw_spin_unlock(&c3_lock);
 895        } else if (!pr->flags.bm_check) {
 896                ACPI_FLUSH_CPU_CACHE();
 897        }
 898
 899        acpi_idle_do_entry(cx);
 900
 901        /* Re-enable bus master arbitration */
 902        if (pr->flags.bm_check && pr->flags.bm_control) {
 903                raw_spin_lock(&c3_lock);
 904                acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 905                c3_cpu_count--;
 906                raw_spin_unlock(&c3_lock);
 907        }
 908
 909        sched_clock_idle_wakeup_event(0);
 910
 911        if (cx->entry_method != ACPI_CSTATE_FFH)
 912                current_thread_info()->status |= TS_POLLING;
 913
 914        lapic_timer_state_broadcast(pr, cx, 0);
 915        return index;
 916}
 917
 918struct cpuidle_driver acpi_idle_driver = {
 919        .name =         "acpi_idle",
 920        .owner =        THIS_MODULE,
 921        .en_core_tk_irqen = 1,
 922};
 923
 924/**
 925 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
 926 * device i.e. per-cpu data
 927 *
 928 * @pr: the ACPI processor
 929 * @dev : the cpuidle device
 930 */
 931static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 932                                           struct cpuidle_device *dev)
 933{
 934        int i, count = CPUIDLE_DRIVER_STATE_START;
 935        struct acpi_processor_cx *cx;
 936
 937        if (!pr->flags.power_setup_done)
 938                return -EINVAL;
 939
 940        if (pr->flags.power == 0) {
 941                return -EINVAL;
 942        }
 943
 944        if (!dev)
 945                return -EINVAL;
 946
 947        dev->cpu = pr->id;
 948
 949        if (max_cstate == 0)
 950                max_cstate = 1;
 951
 952        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 953                cx = &pr->power.states[i];
 954
 955                if (!cx->valid)
 956                        continue;
 957
 958#ifdef CONFIG_HOTPLUG_CPU
 959                if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 960                    !pr->flags.has_cst &&
 961                    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 962                        continue;
 963#endif
 964                per_cpu(acpi_cstate[count], dev->cpu) = cx;
 965
 966                count++;
 967                if (count == CPUIDLE_STATE_MAX)
 968                        break;
 969        }
 970
 971        dev->state_count = count;
 972
 973        if (!count)
 974                return -EINVAL;
 975
 976        return 0;
 977}
 978
 979/**
 980 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
 981 * global state data i.e. idle routines
 982 *
 983 * @pr: the ACPI processor
 984 */
 985static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 986{
 987        int i, count = CPUIDLE_DRIVER_STATE_START;
 988        struct acpi_processor_cx *cx;
 989        struct cpuidle_state *state;
 990        struct cpuidle_driver *drv = &acpi_idle_driver;
 991
 992        if (!pr->flags.power_setup_done)
 993                return -EINVAL;
 994
 995        if (pr->flags.power == 0)
 996                return -EINVAL;
 997
 998        drv->safe_state_index = -1;
 999        for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1000                drv->states[i].name[0] = '\0';
1001                drv->states[i].desc[0] = '\0';
1002        }
1003
1004        if (max_cstate == 0)
1005                max_cstate = 1;
1006
1007        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1008                cx = &pr->power.states[i];
1009
1010                if (!cx->valid)
1011                        continue;
1012
1013#ifdef CONFIG_HOTPLUG_CPU
1014                if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1015                    !pr->flags.has_cst &&
1016                    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1017                        continue;
1018#endif
1019
1020                state = &drv->states[count];
1021                snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1022                strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1023                state->exit_latency = cx->latency;
1024                state->target_residency = cx->latency * latency_factor;
1025
1026                state->flags = 0;
1027                switch (cx->type) {
1028                        case ACPI_STATE_C1:
1029                        if (cx->entry_method == ACPI_CSTATE_FFH)
1030                                state->flags |= CPUIDLE_FLAG_TIME_VALID;
1031
1032                        state->enter = acpi_idle_enter_c1;
1033                        state->enter_dead = acpi_idle_play_dead;
1034                        drv->safe_state_index = count;
1035                        break;
1036
1037                        case ACPI_STATE_C2:
1038                        state->flags |= CPUIDLE_FLAG_TIME_VALID;
1039                        state->enter = acpi_idle_enter_simple;
1040                        state->enter_dead = acpi_idle_play_dead;
1041                        drv->safe_state_index = count;
1042                        break;
1043
1044                        case ACPI_STATE_C3:
1045                        state->flags |= CPUIDLE_FLAG_TIME_VALID;
1046                        state->enter = pr->flags.bm_check ?
1047                                        acpi_idle_enter_bm :
1048                                        acpi_idle_enter_simple;
1049                        break;
1050                }
1051
1052                count++;
1053                if (count == CPUIDLE_STATE_MAX)
1054                        break;
1055        }
1056
1057        drv->state_count = count;
1058
1059        if (!count)
1060                return -EINVAL;
1061
1062        return 0;
1063}
1064
1065int acpi_processor_hotplug(struct acpi_processor *pr)
1066{
1067        int ret = 0;
1068        struct cpuidle_device *dev;
1069
1070        if (disabled_by_idle_boot_param())
1071                return 0;
1072
1073        if (!pr)
1074                return -EINVAL;
1075
1076        if (nocst) {
1077                return -ENODEV;
1078        }
1079
1080        if (!pr->flags.power_setup_done)
1081                return -ENODEV;
1082
1083        dev = per_cpu(acpi_cpuidle_device, pr->id);
1084        cpuidle_pause_and_lock();
1085        cpuidle_disable_device(dev);
1086        acpi_processor_get_power_info(pr);
1087        if (pr->flags.power) {
1088                acpi_processor_setup_cpuidle_cx(pr, dev);
1089                ret = cpuidle_enable_device(dev);
1090        }
1091        cpuidle_resume_and_unlock();
1092
1093        return ret;
1094}
1095
1096int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1097{
1098        int cpu;
1099        struct acpi_processor *_pr;
1100        struct cpuidle_device *dev;
1101
1102        if (disabled_by_idle_boot_param())
1103                return 0;
1104
1105        if (!pr)
1106                return -EINVAL;
1107
1108        if (nocst)
1109                return -ENODEV;
1110
1111        if (!pr->flags.power_setup_done)
1112                return -ENODEV;
1113
1114        /*
1115         * FIXME:  Design the ACPI notification to make it once per
1116         * system instead of once per-cpu.  This condition is a hack
1117         * to make the code that updates C-States be called once.
1118         */
1119
1120        if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1121
1122                cpuidle_pause_and_lock();
1123                /* Protect against cpu-hotplug */
1124                get_online_cpus();
1125
1126                /* Disable all cpuidle devices */
1127                for_each_online_cpu(cpu) {
1128                        _pr = per_cpu(processors, cpu);
1129                        if (!_pr || !_pr->flags.power_setup_done)
1130                                continue;
1131                        dev = per_cpu(acpi_cpuidle_device, cpu);
1132                        cpuidle_disable_device(dev);
1133                }
1134
1135                /* Populate Updated C-state information */
1136                acpi_processor_get_power_info(pr);
1137                acpi_processor_setup_cpuidle_states(pr);
1138
1139                /* Enable all cpuidle devices */
1140                for_each_online_cpu(cpu) {
1141                        _pr = per_cpu(processors, cpu);
1142                        if (!_pr || !_pr->flags.power_setup_done)
1143                                continue;
1144                        acpi_processor_get_power_info(_pr);
1145                        if (_pr->flags.power) {
1146                                dev = per_cpu(acpi_cpuidle_device, cpu);
1147                                acpi_processor_setup_cpuidle_cx(_pr, dev);
1148                                cpuidle_enable_device(dev);
1149                        }
1150                }
1151                put_online_cpus();
1152                cpuidle_resume_and_unlock();
1153        }
1154
1155        return 0;
1156}
1157
1158static int acpi_processor_registered;
1159
1160int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
1161{
1162        acpi_status status = 0;
1163        int retval;
1164        struct cpuidle_device *dev;
1165        static int first_run;
1166
1167        if (disabled_by_idle_boot_param())
1168                return 0;
1169
1170        if (!first_run) {
1171                dmi_check_system(processor_power_dmi_table);
1172                max_cstate = acpi_processor_cstate_check(max_cstate);
1173                if (max_cstate < ACPI_C_STATES_MAX)
1174                        printk(KERN_NOTICE
1175                               "ACPI: processor limited to max C-state %d\n",
1176                               max_cstate);
1177                first_run++;
1178        }
1179
1180        if (!pr)
1181                return -EINVAL;
1182
1183        if (acpi_gbl_FADT.cst_control && !nocst) {
1184                status =
1185                    acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1186                if (ACPI_FAILURE(status)) {
1187                        ACPI_EXCEPTION((AE_INFO, status,
1188                                        "Notifying BIOS of _CST ability failed"));
1189                }
1190        }
1191
1192        acpi_processor_get_power_info(pr);
1193        pr->flags.power_setup_done = 1;
1194
1195        /*
1196         * Install the idle handler if processor power management is supported.
1197         * Note that we use previously set idle handler will be used on
1198         * platforms that only support C1.
1199         */
1200        if (pr->flags.power) {
1201                /* Register acpi_idle_driver if not already registered */
1202                if (!acpi_processor_registered) {
1203                        acpi_processor_setup_cpuidle_states(pr);
1204                        retval = cpuidle_register_driver(&acpi_idle_driver);
1205                        if (retval)
1206                                return retval;
1207                        printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1208                                        acpi_idle_driver.name);
1209                }
1210
1211                dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1212                if (!dev)
1213                        return -ENOMEM;
1214                per_cpu(acpi_cpuidle_device, pr->id) = dev;
1215
1216                acpi_processor_setup_cpuidle_cx(pr, dev);
1217
1218                /* Register per-cpu cpuidle_device. Cpuidle driver
1219                 * must already be registered before registering device
1220                 */
1221                retval = cpuidle_register_device(dev);
1222                if (retval) {
1223                        if (acpi_processor_registered == 0)
1224                                cpuidle_unregister_driver(&acpi_idle_driver);
1225                        return retval;
1226                }
1227                acpi_processor_registered++;
1228        }
1229        return 0;
1230}
1231
1232int acpi_processor_power_exit(struct acpi_processor *pr)
1233{
1234        struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1235
1236        if (disabled_by_idle_boot_param())
1237                return 0;
1238
1239        if (pr->flags.power) {
1240                cpuidle_unregister_device(dev);
1241                acpi_processor_registered--;
1242                if (acpi_processor_registered == 0)
1243                        cpuidle_unregister_driver(&acpi_idle_driver);
1244        }
1245
1246        pr->flags.power_setup_done = 0;
1247        return 0;
1248}
1249
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