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#include <linux/syscore_ops.h>
  38
  39/*
  40 * Include the apic definitions for x86 to have the APIC timer related defines
  41 * available also for UP (on SMP it gets magically included via linux/smp.h).
  42 * asm/acpi.h is not an option, as it would require more include magic. Also
  43 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  44 */
  45#ifdef CONFIG_X86
  46#include <asm/apic.h>
  47#endif
  48
  49#include <acpi/acpi_bus.h>
  50#include <acpi/processor.h>
  51
  52#define PREFIX "ACPI: "
  53
  54#define ACPI_PROCESSOR_CLASS            "processor"
  55#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  56ACPI_MODULE_NAME("processor_idle");
  57
  58static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  59module_param(max_cstate, uint, 0000);
  60static unsigned int nocst __read_mostly;
  61module_param(nocst, uint, 0000);
  62static int bm_check_disable __read_mostly;
  63module_param(bm_check_disable, uint, 0000);
  64
  65static unsigned int latency_factor __read_mostly = 2;
  66module_param(latency_factor, uint, 0644);
  67
  68static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  69
  70static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
  71                                                                acpi_cstate);
  72
  73static int disabled_by_idle_boot_param(void)
  74{
  75        return boot_option_idle_override == IDLE_POLL ||
  76                boot_option_idle_override == IDLE_HALT;
  77}
  78
  79/*
  80 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  81 * For now disable this. Probably a bug somewhere else.
  82 *
  83 * To skip this limit, boot/load with a large max_cstate limit.
  84 */
  85static int set_max_cstate(const struct dmi_system_id *id)
  86{
  87        if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  88                return 0;
  89
  90        printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  91               " Override with \"processor.max_cstate=%d\"\n", id->ident,
  92               (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  93
  94        max_cstate = (long)id->driver_data;
  95
  96        return 0;
  97}
  98
  99static struct dmi_system_id processor_power_dmi_table[] = {
 100        { set_max_cstate, "Clevo 5600D", {
 101          DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 102          DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 103         (void *)2},
 104        { set_max_cstate, "Pavilion zv5000", {
 105          DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 106          DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 107         (void *)1},
 108        { set_max_cstate, "Asus L8400B", {
 109          DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 110          DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 111         (void *)1},
 112        {},
 113};
 114
 115
 116/*
 117 * Callers should disable interrupts before the call and enable
 118 * interrupts after return.
 119 */
 120static void acpi_safe_halt(void)
 121{
 122        current_thread_info()->status &= ~TS_POLLING;
 123        /*
 124         * TS_POLLING-cleared state must be visible before we
 125         * test NEED_RESCHED:
 126         */
 127        smp_mb();
 128        if (!need_resched()) {
 129                safe_halt();
 130                local_irq_disable();
 131        }
 132        current_thread_info()->status |= TS_POLLING;
 133}
 134
 135#ifdef ARCH_APICTIMER_STOPS_ON_C3
 136
 137/*
 138 * Some BIOS implementations switch to C3 in the published C2 state.
 139 * This seems to be a common problem on AMD boxen, but other vendors
 140 * are affected too. We pick the most conservative approach: we assume
 141 * that the local APIC stops in both C2 and C3.
 142 */
 143static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 144                                   struct acpi_processor_cx *cx)
 145{
 146        struct acpi_processor_power *pwr = &pr->power;
 147        u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 148
 149        if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 150                return;
 151
 152        if (amd_e400_c1e_detected)
 153                type = ACPI_STATE_C1;
 154
 155        /*
 156         * Check, if one of the previous states already marked the lapic
 157         * unstable
 158         */
 159        if (pwr->timer_broadcast_on_state < state)
 160                return;
 161
 162        if (cx->type >= type)
 163                pr->power.timer_broadcast_on_state = state;
 164}
 165
 166static void __lapic_timer_propagate_broadcast(void *arg)
 167{
 168        struct acpi_processor *pr = (struct acpi_processor *) arg;
 169        unsigned long reason;
 170
 171        reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 172                CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 173
 174        clockevents_notify(reason, &pr->id);
 175}
 176
 177static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 178{
 179        smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 180                                 (void *)pr, 1);
 181}
 182
 183/* Power(C) State timer broadcast control */
 184static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 185                                       struct acpi_processor_cx *cx,
 186                                       int broadcast)
 187{
 188        int state = cx - pr->power.states;
 189
 190        if (state >= pr->power.timer_broadcast_on_state) {
 191                unsigned long reason;
 192
 193                reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 194                        CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 195                clockevents_notify(reason, &pr->id);
 196        }
 197}
 198
 199#else
 200
 201static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 202                                   struct acpi_processor_cx *cstate) { }
 203static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 204static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 205                                       struct acpi_processor_cx *cx,
 206                                       int broadcast)
 207{
 208}
 209
 210#endif
 211
 212#ifdef CONFIG_PM_SLEEP
 213static u32 saved_bm_rld;
 214
 215static int acpi_processor_suspend(void)
 216{
 217        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 218        return 0;
 219}
 220
 221static void acpi_processor_resume(void)
 222{
 223        u32 resumed_bm_rld;
 224
 225        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 226        if (resumed_bm_rld == saved_bm_rld)
 227                return;
 228
 229        acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 230}
 231
 232static struct syscore_ops acpi_processor_syscore_ops = {
 233        .suspend = acpi_processor_suspend,
 234        .resume = acpi_processor_resume,
 235};
 236
 237void acpi_processor_syscore_init(void)
 238{
 239        register_syscore_ops(&acpi_processor_syscore_ops);
 240}
 241
 242void acpi_processor_syscore_exit(void)
 243{
 244        unregister_syscore_ops(&acpi_processor_syscore_ops);
 245}
 246#endif /* CONFIG_PM_SLEEP */
 247
 248#if defined(CONFIG_X86)
 249static void tsc_check_state(int state)
 250{
 251        switch (boot_cpu_data.x86_vendor) {
 252        case X86_VENDOR_AMD:
 253        case X86_VENDOR_INTEL:
 254                /*
 255                 * AMD Fam10h TSC will tick in all
 256                 * C/P/S0/S1 states when this bit is set.
 257                 */
 258                if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 259                        return;
 260
 261                /*FALL THROUGH*/
 262        default:
 263                /* TSC could halt in idle, so notify users */
 264                if (state > ACPI_STATE_C1)
 265                        mark_tsc_unstable("TSC halts in idle");
 266        }
 267}
 268#else
 269static void tsc_check_state(int state) { return; }
 270#endif
 271
 272static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 273{
 274
 275        if (!pr)
 276                return -EINVAL;
 277
 278        if (!pr->pblk)
 279                return -ENODEV;
 280
 281        /* if info is obtained from pblk/fadt, type equals state */
 282        pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 283        pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 284
 285#ifndef CONFIG_HOTPLUG_CPU
 286        /*
 287         * Check for P_LVL2_UP flag before entering C2 and above on
 288         * an SMP system.
 289         */
 290        if ((num_online_cpus() > 1) &&
 291            !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 292                return -ENODEV;
 293#endif
 294
 295        /* determine C2 and C3 address from pblk */
 296        pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 297        pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 298
 299        /* determine latencies from FADT */
 300        pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 301        pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 302
 303        /*
 304         * FADT specified C2 latency must be less than or equal to
 305         * 100 microseconds.
 306         */
 307        if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 308                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 309                        "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 310                /* invalidate C2 */
 311                pr->power.states[ACPI_STATE_C2].address = 0;
 312        }
 313
 314        /*
 315         * FADT supplied C3 latency must be less than or equal to
 316         * 1000 microseconds.
 317         */
 318        if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 319                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 320                        "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 321                /* invalidate C3 */
 322                pr->power.states[ACPI_STATE_C3].address = 0;
 323        }
 324
 325        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 326                          "lvl2[0x%08x] lvl3[0x%08x]\n",
 327                          pr->power.states[ACPI_STATE_C2].address,
 328                          pr->power.states[ACPI_STATE_C3].address));
 329
 330        return 0;
 331}
 332
 333static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 334{
 335        if (!pr->power.states[ACPI_STATE_C1].valid) {
 336                /* set the first C-State to C1 */
 337                /* all processors need to support C1 */
 338                pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 339                pr->power.states[ACPI_STATE_C1].valid = 1;
 340                pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 341        }
 342        /* the C0 state only exists as a filler in our array */
 343        pr->power.states[ACPI_STATE_C0].valid = 1;
 344        return 0;
 345}
 346
 347static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 348{
 349        acpi_status status = 0;
 350        u64 count;
 351        int current_count;
 352        int i;
 353        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 354        union acpi_object *cst;
 355
 356
 357        if (nocst)
 358                return -ENODEV;
 359
 360        current_count = 0;
 361
 362        status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 363        if (ACPI_FAILURE(status)) {
 364                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 365                return -ENODEV;
 366        }
 367
 368        cst = buffer.pointer;
 369
 370        /* There must be at least 2 elements */
 371        if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 372                printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 373                status = -EFAULT;
 374                goto end;
 375        }
 376
 377        count = cst->package.elements[0].integer.value;
 378
 379        /* Validate number of power states. */
 380        if (count < 1 || count != cst->package.count - 1) {
 381                printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 382                status = -EFAULT;
 383                goto end;
 384        }
 385
 386        /* Tell driver that at least _CST is supported. */
 387        pr->flags.has_cst = 1;
 388
 389        for (i = 1; i <= count; i++) {
 390                union acpi_object *element;
 391                union acpi_object *obj;
 392                struct acpi_power_register *reg;
 393                struct acpi_processor_cx cx;
 394
 395                memset(&cx, 0, sizeof(cx));
 396
 397                element = &(cst->package.elements[i]);
 398                if (element->type != ACPI_TYPE_PACKAGE)
 399                        continue;
 400
 401                if (element->package.count != 4)
 402                        continue;
 403
 404                obj = &(element->package.elements[0]);
 405
 406                if (obj->type != ACPI_TYPE_BUFFER)
 407                        continue;
 408
 409                reg = (struct acpi_power_register *)obj->buffer.pointer;
 410
 411                if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 412                    (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 413                        continue;
 414
 415                /* There should be an easy way to extract an integer... */
 416                obj = &(element->package.elements[1]);
 417                if (obj->type != ACPI_TYPE_INTEGER)
 418                        continue;
 419
 420                cx.type = obj->integer.value;
 421                /*
 422                 * Some buggy BIOSes won't list C1 in _CST -
 423                 * Let acpi_processor_get_power_info_default() handle them later
 424                 */
 425                if (i == 1 && cx.type != ACPI_STATE_C1)
 426                        current_count++;
 427
 428                cx.address = reg->address;
 429                cx.index = current_count + 1;
 430
 431                cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 432                if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 433                        if (acpi_processor_ffh_cstate_probe
 434                                        (pr->id, &cx, reg) == 0) {
 435                                cx.entry_method = ACPI_CSTATE_FFH;
 436                        } else if (cx.type == ACPI_STATE_C1) {
 437                                /*
 438                                 * C1 is a special case where FIXED_HARDWARE
 439                                 * can be handled in non-MWAIT way as well.
 440                                 * In that case, save this _CST entry info.
 441                                 * Otherwise, ignore this info and continue.
 442                                 */
 443                                cx.entry_method = ACPI_CSTATE_HALT;
 444                                snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 445                        } else {
 446                                continue;
 447                        }
 448                        if (cx.type == ACPI_STATE_C1 &&
 449                            (boot_option_idle_override == IDLE_NOMWAIT)) {
 450                                /*
 451                                 * In most cases the C1 space_id obtained from
 452                                 * _CST object is FIXED_HARDWARE access mode.
 453                                 * But when the option of idle=halt is added,
 454                                 * the entry_method type should be changed from
 455                                 * CSTATE_FFH to CSTATE_HALT.
 456                                 * When the option of idle=nomwait is added,
 457                                 * the C1 entry_method type should be
 458                                 * CSTATE_HALT.
 459                                 */
 460                                cx.entry_method = ACPI_CSTATE_HALT;
 461                                snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 462                        }
 463                } else {
 464                        snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 465                                 cx.address);
 466                }
 467
 468                if (cx.type == ACPI_STATE_C1) {
 469                        cx.valid = 1;
 470                }
 471
 472                obj = &(element->package.elements[2]);
 473                if (obj->type != ACPI_TYPE_INTEGER)
 474                        continue;
 475
 476                cx.latency = obj->integer.value;
 477
 478                obj = &(element->package.elements[3]);
 479                if (obj->type != ACPI_TYPE_INTEGER)
 480                        continue;
 481
 482                current_count++;
 483                memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 484
 485                /*
 486                 * We support total ACPI_PROCESSOR_MAX_POWER - 1
 487                 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 488                 */
 489                if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 490                        printk(KERN_WARNING
 491                               "Limiting number of power states to max (%d)\n",
 492                               ACPI_PROCESSOR_MAX_POWER);
 493                        printk(KERN_WARNING
 494                               "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 495                        break;
 496                }
 497        }
 498
 499        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 500                          current_count));
 501
 502        /* Validate number of power states discovered */
 503        if (current_count < 2)
 504                status = -EFAULT;
 505
 506      end:
 507        kfree(buffer.pointer);
 508
 509        return status;
 510}
 511
 512static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 513                                           struct acpi_processor_cx *cx)
 514{
 515        static int bm_check_flag = -1;
 516        static int bm_control_flag = -1;
 517
 518
 519        if (!cx->address)
 520                return;
 521
 522        /*
 523         * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 524         * DMA transfers are used by any ISA device to avoid livelock.
 525         * Note that we could disable Type-F DMA (as recommended by
 526         * the erratum), but this is known to disrupt certain ISA
 527         * devices thus we take the conservative approach.
 528         */
 529        else if (errata.piix4.fdma) {
 530                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 531                                  "C3 not supported on PIIX4 with Type-F DMA\n"));
 532                return;
 533        }
 534
 535        /* All the logic here assumes flags.bm_check is same across all CPUs */
 536        if (bm_check_flag == -1) {
 537                /* Determine whether bm_check is needed based on CPU  */
 538                acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 539                bm_check_flag = pr->flags.bm_check;
 540                bm_control_flag = pr->flags.bm_control;
 541        } else {
 542                pr->flags.bm_check = bm_check_flag;
 543                pr->flags.bm_control = bm_control_flag;
 544        }
 545
 546        if (pr->flags.bm_check) {
 547                if (!pr->flags.bm_control) {
 548                        if (pr->flags.has_cst != 1) {
 549                                /* bus mastering control is necessary */
 550                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 551                                        "C3 support requires BM control\n"));
 552                                return;
 553                        } else {
 554                                /* Here we enter C3 without bus mastering */
 555                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 556                                        "C3 support without BM control\n"));
 557                        }
 558                }
 559        } else {
 560                /*
 561                 * WBINVD should be set in fadt, for C3 state to be
 562                 * supported on when bm_check is not required.
 563                 */
 564                if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 565                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 566                                          "Cache invalidation should work properly"
 567                                          " for C3 to be enabled on SMP systems\n"));
 568                        return;
 569                }
 570        }
 571
 572        /*
 573         * Otherwise we've met all of our C3 requirements.
 574         * Normalize the C3 latency to expidite policy.  Enable
 575         * checking of bus mastering status (bm_check) so we can
 576         * use this in our C3 policy
 577         */
 578        cx->valid = 1;
 579
 580        /*
 581         * On older chipsets, BM_RLD needs to be set
 582         * in order for Bus Master activity to wake the
 583         * system from C3.  Newer chipsets handle DMA
 584         * during C3 automatically and BM_RLD is a NOP.
 585         * In either case, the proper way to
 586         * handle BM_RLD is to set it and leave it set.
 587         */
 588        acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 589
 590        return;
 591}
 592
 593static int acpi_processor_power_verify(struct acpi_processor *pr)
 594{
 595        unsigned int i;
 596        unsigned int working = 0;
 597
 598        pr->power.timer_broadcast_on_state = INT_MAX;
 599
 600        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 601                struct acpi_processor_cx *cx = &pr->power.states[i];
 602
 603                switch (cx->type) {
 604                case ACPI_STATE_C1:
 605                        cx->valid = 1;
 606                        break;
 607
 608                case ACPI_STATE_C2:
 609                        if (!cx->address)
 610                                break;
 611                        cx->valid = 1; 
 612                        break;
 613
 614                case ACPI_STATE_C3:
 615                        acpi_processor_power_verify_c3(pr, cx);
 616                        break;
 617                }
 618                if (!cx->valid)
 619                        continue;
 620
 621                lapic_timer_check_state(i, pr, cx);
 622                tsc_check_state(cx->type);
 623                working++;
 624        }
 625
 626        lapic_timer_propagate_broadcast(pr);
 627
 628        return (working);
 629}
 630
 631static int acpi_processor_get_power_info(struct acpi_processor *pr)
 632{
 633        unsigned int i;
 634        int result;
 635
 636
 637        /* NOTE: the idle thread may not be running while calling
 638         * this function */
 639
 640        /* Zero initialize all the C-states info. */
 641        memset(pr->power.states, 0, sizeof(pr->power.states));
 642
 643        result = acpi_processor_get_power_info_cst(pr);
 644        if (result == -ENODEV)
 645                result = acpi_processor_get_power_info_fadt(pr);
 646
 647        if (result)
 648                return result;
 649
 650        acpi_processor_get_power_info_default(pr);
 651
 652        pr->power.count = acpi_processor_power_verify(pr);
 653
 654        /*
 655         * if one state of type C2 or C3 is available, mark this
 656         * CPU as being "idle manageable"
 657         */
 658        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 659                if (pr->power.states[i].valid) {
 660                        pr->power.count = i;
 661                        if (pr->power.states[i].type >= ACPI_STATE_C2)
 662                                pr->flags.power = 1;
 663                }
 664        }
 665
 666        return 0;
 667}
 668
 669/**
 670 * acpi_idle_bm_check - checks if bus master activity was detected
 671 */
 672static int acpi_idle_bm_check(void)
 673{
 674        u32 bm_status = 0;
 675
 676        if (bm_check_disable)
 677                return 0;
 678
 679        acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 680        if (bm_status)
 681                acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 682        /*
 683         * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 684         * the true state of bus mastering activity; forcing us to
 685         * manually check the BMIDEA bit of each IDE channel.
 686         */
 687        else if (errata.piix4.bmisx) {
 688                if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 689                    || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 690                        bm_status = 1;
 691        }
 692        return bm_status;
 693}
 694
 695/**
 696 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 697 * @cx: cstate data
 698 *
 699 * Caller disables interrupt before call and enables interrupt after return.
 700 */
 701static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 702{
 703        /* Don't trace irqs off for idle */
 704        stop_critical_timings();
 705        if (cx->entry_method == ACPI_CSTATE_FFH) {
 706                /* Call into architectural FFH based C-state */
 707                acpi_processor_ffh_cstate_enter(cx);
 708        } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 709                acpi_safe_halt();
 710        } else {
 711                /* IO port based C-state */
 712                inb(cx->address);
 713                /* Dummy wait op - must do something useless after P_LVL2 read
 714                   because chipsets cannot guarantee that STPCLK# signal
 715                   gets asserted in time to freeze execution properly. */
 716                inl(acpi_gbl_FADT.xpm_timer_block.address);
 717        }
 718        start_critical_timings();
 719}
 720
 721/**
 722 * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 723 * @dev: the target CPU
 724 * @drv: cpuidle driver containing cpuidle state info
 725 * @index: index of target state
 726 *
 727 * This is equivalent to the HALT instruction.
 728 */
 729static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 730                struct cpuidle_driver *drv, int index)
 731{
 732        struct acpi_processor *pr;
 733        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 734
 735        pr = __this_cpu_read(processors);
 736
 737        if (unlikely(!pr))
 738                return -EINVAL;
 739
 740        lapic_timer_state_broadcast(pr, cx, 1);
 741        acpi_idle_do_entry(cx);
 742
 743        lapic_timer_state_broadcast(pr, cx, 0);
 744
 745        return index;
 746}
 747
 748
 749/**
 750 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 751 * @dev: the target CPU
 752 * @index: the index of suggested state
 753 */
 754static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 755{
 756        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 757
 758        ACPI_FLUSH_CPU_CACHE();
 759
 760        while (1) {
 761
 762                if (cx->entry_method == ACPI_CSTATE_HALT)
 763                        safe_halt();
 764                else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 765                        inb(cx->address);
 766                        /* See comment in acpi_idle_do_entry() */
 767                        inl(acpi_gbl_FADT.xpm_timer_block.address);
 768                } else
 769                        return -ENODEV;
 770        }
 771
 772        /* Never reached */
 773        return 0;
 774}
 775
 776/**
 777 * acpi_idle_enter_simple - enters an ACPI state without BM handling
 778 * @dev: the target CPU
 779 * @drv: cpuidle driver with cpuidle state information
 780 * @index: the index of suggested state
 781 */
 782static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 783                struct cpuidle_driver *drv, int index)
 784{
 785        struct acpi_processor *pr;
 786        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 787
 788        pr = __this_cpu_read(processors);
 789
 790        if (unlikely(!pr))
 791                return -EINVAL;
 792
 793        if (cx->entry_method != ACPI_CSTATE_FFH) {
 794                current_thread_info()->status &= ~TS_POLLING;
 795                /*
 796                 * TS_POLLING-cleared state must be visible before we test
 797                 * NEED_RESCHED:
 798                 */
 799                smp_mb();
 800
 801                if (unlikely(need_resched())) {
 802                        current_thread_info()->status |= TS_POLLING;
 803                        return -EINVAL;
 804                }
 805        }
 806
 807        /*
 808         * Must be done before busmaster disable as we might need to
 809         * access HPET !
 810         */
 811        lapic_timer_state_broadcast(pr, cx, 1);
 812
 813        if (cx->type == ACPI_STATE_C3)
 814                ACPI_FLUSH_CPU_CACHE();
 815
 816        /* Tell the scheduler that we are going deep-idle: */
 817        sched_clock_idle_sleep_event();
 818        acpi_idle_do_entry(cx);
 819
 820        sched_clock_idle_wakeup_event(0);
 821
 822        if (cx->entry_method != ACPI_CSTATE_FFH)
 823                current_thread_info()->status |= TS_POLLING;
 824
 825        lapic_timer_state_broadcast(pr, cx, 0);
 826        return index;
 827}
 828
 829static int c3_cpu_count;
 830static DEFINE_RAW_SPINLOCK(c3_lock);
 831
 832/**
 833 * acpi_idle_enter_bm - enters C3 with proper BM handling
 834 * @dev: the target CPU
 835 * @drv: cpuidle driver containing state data
 836 * @index: the index of suggested state
 837 *
 838 * If BM is detected, the deepest non-C3 idle state is entered instead.
 839 */
 840static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 841                struct cpuidle_driver *drv, int index)
 842{
 843        struct acpi_processor *pr;
 844        struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 845
 846        pr = __this_cpu_read(processors);
 847
 848        if (unlikely(!pr))
 849                return -EINVAL;
 850
 851        if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 852                if (drv->safe_state_index >= 0) {
 853                        return drv->states[drv->safe_state_index].enter(dev,
 854                                                drv, drv->safe_state_index);
 855                } else {
 856                        acpi_safe_halt();
 857                        return -EBUSY;
 858                }
 859        }
 860
 861        if (cx->entry_method != ACPI_CSTATE_FFH) {
 862                current_thread_info()->status &= ~TS_POLLING;
 863                /*
 864                 * TS_POLLING-cleared state must be visible before we test
 865                 * NEED_RESCHED:
 866                 */
 867                smp_mb();
 868
 869                if (unlikely(need_resched())) {
 870                        current_thread_info()->status |= TS_POLLING;
 871                        return -EINVAL;
 872                }
 873        }
 874
 875        acpi_unlazy_tlb(smp_processor_id());
 876
 877        /* Tell the scheduler that we are going deep-idle: */
 878        sched_clock_idle_sleep_event();
 879        /*
 880         * Must be done before busmaster disable as we might need to
 881         * access HPET !
 882         */
 883        lapic_timer_state_broadcast(pr, cx, 1);
 884
 885        /*
 886         * disable bus master
 887         * bm_check implies we need ARB_DIS
 888         * !bm_check implies we need cache flush
 889         * bm_control implies whether we can do ARB_DIS
 890         *
 891         * That leaves a case where bm_check is set and bm_control is
 892         * not set. In that case we cannot do much, we enter C3
 893         * without doing anything.
 894         */
 895        if (pr->flags.bm_check && pr->flags.bm_control) {
 896                raw_spin_lock(&c3_lock);
 897                c3_cpu_count++;
 898                /* Disable bus master arbitration when all CPUs are in C3 */
 899                if (c3_cpu_count == num_online_cpus())
 900                        acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 901                raw_spin_unlock(&c3_lock);
 902        } else if (!pr->flags.bm_check) {
 903                ACPI_FLUSH_CPU_CACHE();
 904        }
 905
 906        acpi_idle_do_entry(cx);
 907
 908        /* Re-enable bus master arbitration */
 909        if (pr->flags.bm_check && pr->flags.bm_control) {
 910                raw_spin_lock(&c3_lock);
 911                acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 912                c3_cpu_count--;
 913                raw_spin_unlock(&c3_lock);
 914        }
 915
 916        sched_clock_idle_wakeup_event(0);
 917
 918        if (cx->entry_method != ACPI_CSTATE_FFH)
 919                current_thread_info()->status |= TS_POLLING;
 920
 921        lapic_timer_state_broadcast(pr, cx, 0);
 922        return index;
 923}
 924
 925struct cpuidle_driver acpi_idle_driver = {
 926        .name =         "acpi_idle",
 927        .owner =        THIS_MODULE,
 928};
 929
 930/**
 931 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
 932 * device i.e. per-cpu data
 933 *
 934 * @pr: the ACPI processor
 935 * @dev : the cpuidle device
 936 */
 937static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 938                                           struct cpuidle_device *dev)
 939{
 940        int i, count = CPUIDLE_DRIVER_STATE_START;
 941        struct acpi_processor_cx *cx;
 942
 943        if (!pr->flags.power_setup_done)
 944                return -EINVAL;
 945
 946        if (pr->flags.power == 0) {
 947                return -EINVAL;
 948        }
 949
 950        if (!dev)
 951                return -EINVAL;
 952
 953        dev->cpu = pr->id;
 954
 955        if (max_cstate == 0)
 956                max_cstate = 1;
 957
 958        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 959                cx = &pr->power.states[i];
 960
 961                if (!cx->valid)
 962                        continue;
 963
 964#ifdef CONFIG_HOTPLUG_CPU
 965                if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 966                    !pr->flags.has_cst &&
 967                    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 968                        continue;
 969#endif
 970                per_cpu(acpi_cstate[count], dev->cpu) = cx;
 971
 972                count++;
 973                if (count == CPUIDLE_STATE_MAX)
 974                        break;
 975        }
 976
 977        dev->state_count = count;
 978
 979        if (!count)
 980                return -EINVAL;
 981
 982        return 0;
 983}
 984
 985/**
 986 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
 987 * global state data i.e. idle routines
 988 *
 989 * @pr: the ACPI processor
 990 */
 991static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 992{
 993        int i, count = CPUIDLE_DRIVER_STATE_START;
 994        struct acpi_processor_cx *cx;
 995        struct cpuidle_state *state;
 996        struct cpuidle_driver *drv = &acpi_idle_driver;
 997
 998        if (!pr->flags.power_setup_done)
 999                return -EINVAL;
1000
1001        if (pr->flags.power == 0)
1002                return -EINVAL;
1003
1004        drv->safe_state_index = -1;
1005        for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1006                drv->states[i].name[0] = '\0';
1007                drv->states[i].desc[0] = '\0';
1008        }
1009
1010        if (max_cstate == 0)
1011                max_cstate = 1;
1012
1013        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1014                cx = &pr->power.states[i];
1015
1016                if (!cx->valid)
1017                        continue;
1018
1019#ifdef CONFIG_HOTPLUG_CPU
1020                if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1021                    !pr->flags.has_cst &&
1022                    !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1023                        continue;
1024#endif
1025
1026                state = &drv->states[count];
1027                snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1028                strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1029                state->exit_latency = cx->latency;
1030                state->target_residency = cx->latency * latency_factor;
1031
1032                state->flags = 0;
1033                switch (cx->type) {
1034                        case ACPI_STATE_C1:
1035                        if (cx->entry_method == ACPI_CSTATE_FFH)
1036                                state->flags |= CPUIDLE_FLAG_TIME_VALID;
1037
1038                        state->enter = acpi_idle_enter_c1;
1039                        state->enter_dead = acpi_idle_play_dead;
1040                        drv->safe_state_index = count;
1041                        break;
1042
1043                        case ACPI_STATE_C2:
1044                        state->flags |= CPUIDLE_FLAG_TIME_VALID;
1045                        state->enter = acpi_idle_enter_simple;
1046                        state->enter_dead = acpi_idle_play_dead;
1047                        drv->safe_state_index = count;
1048                        break;
1049
1050                        case ACPI_STATE_C3:
1051                        state->flags |= CPUIDLE_FLAG_TIME_VALID;
1052                        state->enter = pr->flags.bm_check ?
1053                                        acpi_idle_enter_bm :
1054                                        acpi_idle_enter_simple;
1055                        break;
1056                }
1057
1058                count++;
1059                if (count == CPUIDLE_STATE_MAX)
1060                        break;
1061        }
1062
1063        drv->state_count = count;
1064
1065        if (!count)
1066                return -EINVAL;
1067
1068        return 0;
1069}
1070
1071int acpi_processor_hotplug(struct acpi_processor *pr)
1072{
1073        int ret = 0;
1074        struct cpuidle_device *dev;
1075
1076        if (disabled_by_idle_boot_param())
1077                return 0;
1078
1079        if (!pr)
1080                return -EINVAL;
1081
1082        if (nocst) {
1083                return -ENODEV;
1084        }
1085
1086        if (!pr->flags.power_setup_done)
1087                return -ENODEV;
1088
1089        dev = per_cpu(acpi_cpuidle_device, pr->id);
1090        cpuidle_pause_and_lock();
1091        cpuidle_disable_device(dev);
1092        acpi_processor_get_power_info(pr);
1093        if (pr->flags.power) {
1094                acpi_processor_setup_cpuidle_cx(pr, dev);
1095                ret = cpuidle_enable_device(dev);
1096        }
1097        cpuidle_resume_and_unlock();
1098
1099        return ret;
1100}
1101
1102int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1103{
1104        int cpu;
1105        struct acpi_processor *_pr;
1106        struct cpuidle_device *dev;
1107
1108        if (disabled_by_idle_boot_param())
1109                return 0;
1110
1111        if (!pr)
1112                return -EINVAL;
1113
1114        if (nocst)
1115                return -ENODEV;
1116
1117        if (!pr->flags.power_setup_done)
1118                return -ENODEV;
1119
1120        /*
1121         * FIXME:  Design the ACPI notification to make it once per
1122         * system instead of once per-cpu.  This condition is a hack
1123         * to make the code that updates C-States be called once.
1124         */
1125
1126        if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1127
1128                cpuidle_pause_and_lock();
1129                /* Protect against cpu-hotplug */
1130                get_online_cpus();
1131
1132                /* Disable all cpuidle devices */
1133                for_each_online_cpu(cpu) {
1134                        _pr = per_cpu(processors, cpu);
1135                        if (!_pr || !_pr->flags.power_setup_done)
1136                                continue;
1137                        dev = per_cpu(acpi_cpuidle_device, cpu);
1138                        cpuidle_disable_device(dev);
1139                }
1140
1141                /* Populate Updated C-state information */
1142                acpi_processor_get_power_info(pr);
1143                acpi_processor_setup_cpuidle_states(pr);
1144
1145                /* Enable all cpuidle devices */
1146                for_each_online_cpu(cpu) {
1147                        _pr = per_cpu(processors, cpu);
1148                        if (!_pr || !_pr->flags.power_setup_done)
1149                                continue;
1150                        acpi_processor_get_power_info(_pr);
1151                        if (_pr->flags.power) {
1152                                dev = per_cpu(acpi_cpuidle_device, cpu);
1153                                acpi_processor_setup_cpuidle_cx(_pr, dev);
1154                                cpuidle_enable_device(dev);
1155                        }
1156                }
1157                put_online_cpus();
1158                cpuidle_resume_and_unlock();
1159        }
1160
1161        return 0;
1162}
1163
1164static int acpi_processor_registered;
1165
1166int acpi_processor_power_init(struct acpi_processor *pr)
1167{
1168        acpi_status status = 0;
1169        int retval;
1170        struct cpuidle_device *dev;
1171        static int first_run;
1172
1173        if (disabled_by_idle_boot_param())
1174                return 0;
1175
1176        if (!first_run) {
1177                dmi_check_system(processor_power_dmi_table);
1178                max_cstate = acpi_processor_cstate_check(max_cstate);
1179                if (max_cstate < ACPI_C_STATES_MAX)
1180                        printk(KERN_NOTICE
1181                               "ACPI: processor limited to max C-state %d\n",
1182                               max_cstate);
1183                first_run++;
1184        }
1185
1186        if (!pr)
1187                return -EINVAL;
1188
1189        if (acpi_gbl_FADT.cst_control && !nocst) {
1190                status =
1191                    acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1192                if (ACPI_FAILURE(status)) {
1193                        ACPI_EXCEPTION((AE_INFO, status,
1194                                        "Notifying BIOS of _CST ability failed"));
1195                }
1196        }
1197
1198        acpi_processor_get_power_info(pr);
1199        pr->flags.power_setup_done = 1;
1200
1201        /*
1202         * Install the idle handler if processor power management is supported.
1203         * Note that we use previously set idle handler will be used on
1204         * platforms that only support C1.
1205         */
1206        if (pr->flags.power) {
1207                /* Register acpi_idle_driver if not already registered */
1208                if (!acpi_processor_registered) {
1209                        acpi_processor_setup_cpuidle_states(pr);
1210                        retval = cpuidle_register_driver(&acpi_idle_driver);
1211                        if (retval)
1212                                return retval;
1213                        printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1214                                        acpi_idle_driver.name);
1215                }
1216
1217                dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1218                if (!dev)
1219                        return -ENOMEM;
1220                per_cpu(acpi_cpuidle_device, pr->id) = dev;
1221
1222                acpi_processor_setup_cpuidle_cx(pr, dev);
1223
1224                /* Register per-cpu cpuidle_device. Cpuidle driver
1225                 * must already be registered before registering device
1226                 */
1227                retval = cpuidle_register_device(dev);
1228                if (retval) {
1229                        if (acpi_processor_registered == 0)
1230                                cpuidle_unregister_driver(&acpi_idle_driver);
1231                        return retval;
1232                }
1233                acpi_processor_registered++;
1234        }
1235        return 0;
1236}
1237
1238int acpi_processor_power_exit(struct acpi_processor *pr)
1239{
1240        struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1241
1242        if (disabled_by_idle_boot_param())
1243                return 0;
1244
1245        if (pr->flags.power) {
1246                cpuidle_unregister_device(dev);
1247                acpi_processor_registered--;
1248                if (acpi_processor_registered == 0)
1249                        cpuidle_unregister_driver(&acpi_idle_driver);
1250        }
1251
1252        pr->flags.power_setup_done = 0;
1253        return 0;
1254}
1255
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