linux/drivers/acpi/processor_throttling.c
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   1/*
   2 * processor_throttling.c - Throttling submodule of 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       Dominik Brodowski <linux@brodo.de>
   7 *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8 *                      - Added processor hotplug support
   9 *
  10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11 *
  12 *  This program is free software; you can redistribute it and/or modify
  13 *  it under the terms of the GNU General Public License as published by
  14 *  the Free Software Foundation; either version 2 of the License, or (at
  15 *  your option) any later version.
  16 *
  17 *  This program is distributed in the hope that it will be useful, but
  18 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 *  General Public License for more details.
  21 *
  22 *  You should have received a copy of the GNU General Public License along
  23 *  with this program; if not, write to the Free Software Foundation, Inc.,
  24 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25 *
  26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27 */
  28
  29#include <linux/kernel.h>
  30#include <linux/module.h>
  31#include <linux/slab.h>
  32#include <linux/init.h>
  33#include <linux/sched.h>
  34#include <linux/cpufreq.h>
  35
  36#include <asm/io.h>
  37#include <asm/uaccess.h>
  38
  39#include <acpi/acpi_bus.h>
  40#include <acpi/acpi_drivers.h>
  41#include <acpi/processor.h>
  42
  43#define PREFIX "ACPI: "
  44
  45#define ACPI_PROCESSOR_CLASS            "processor"
  46#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  47ACPI_MODULE_NAME("processor_throttling");
  48
  49/* ignore_tpc:
  50 *  0 -> acpi processor driver doesn't ignore _TPC values
  51 *  1 -> acpi processor driver ignores _TPC values
  52 */
  53static int ignore_tpc;
  54module_param(ignore_tpc, int, 0644);
  55MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  56
  57struct throttling_tstate {
  58        unsigned int cpu;               /* cpu nr */
  59        int target_state;               /* target T-state */
  60};
  61
  62#define THROTTLING_PRECHANGE       (1)
  63#define THROTTLING_POSTCHANGE      (2)
  64
  65static int acpi_processor_get_throttling(struct acpi_processor *pr);
  66int acpi_processor_set_throttling(struct acpi_processor *pr,
  67                                                int state, bool force);
  68
  69static int acpi_processor_update_tsd_coord(void)
  70{
  71        int count, count_target;
  72        int retval = 0;
  73        unsigned int i, j;
  74        cpumask_var_t covered_cpus;
  75        struct acpi_processor *pr, *match_pr;
  76        struct acpi_tsd_package *pdomain, *match_pdomain;
  77        struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  78
  79        if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  80                return -ENOMEM;
  81
  82        /*
  83         * Now that we have _TSD data from all CPUs, lets setup T-state
  84         * coordination between all CPUs.
  85         */
  86        for_each_possible_cpu(i) {
  87                pr = per_cpu(processors, i);
  88                if (!pr)
  89                        continue;
  90
  91                /* Basic validity check for domain info */
  92                pthrottling = &(pr->throttling);
  93
  94                /*
  95                 * If tsd package for one cpu is invalid, the coordination
  96                 * among all CPUs is thought as invalid.
  97                 * Maybe it is ugly.
  98                 */
  99                if (!pthrottling->tsd_valid_flag) {
 100                        retval = -EINVAL;
 101                        break;
 102                }
 103        }
 104        if (retval)
 105                goto err_ret;
 106
 107        for_each_possible_cpu(i) {
 108                pr = per_cpu(processors, i);
 109                if (!pr)
 110                        continue;
 111
 112                if (cpumask_test_cpu(i, covered_cpus))
 113                        continue;
 114                pthrottling = &pr->throttling;
 115
 116                pdomain = &(pthrottling->domain_info);
 117                cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 118                cpumask_set_cpu(i, covered_cpus);
 119                /*
 120                 * If the number of processor in the TSD domain is 1, it is
 121                 * unnecessary to parse the coordination for this CPU.
 122                 */
 123                if (pdomain->num_processors <= 1)
 124                        continue;
 125
 126                /* Validate the Domain info */
 127                count_target = pdomain->num_processors;
 128                count = 1;
 129
 130                for_each_possible_cpu(j) {
 131                        if (i == j)
 132                                continue;
 133
 134                        match_pr = per_cpu(processors, j);
 135                        if (!match_pr)
 136                                continue;
 137
 138                        match_pthrottling = &(match_pr->throttling);
 139                        match_pdomain = &(match_pthrottling->domain_info);
 140                        if (match_pdomain->domain != pdomain->domain)
 141                                continue;
 142
 143                        /* Here i and j are in the same domain.
 144                         * If two TSD packages have the same domain, they
 145                         * should have the same num_porcessors and
 146                         * coordination type. Otherwise it will be regarded
 147                         * as illegal.
 148                         */
 149                        if (match_pdomain->num_processors != count_target) {
 150                                retval = -EINVAL;
 151                                goto err_ret;
 152                        }
 153
 154                        if (pdomain->coord_type != match_pdomain->coord_type) {
 155                                retval = -EINVAL;
 156                                goto err_ret;
 157                        }
 158
 159                        cpumask_set_cpu(j, covered_cpus);
 160                        cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 161                        count++;
 162                }
 163                for_each_possible_cpu(j) {
 164                        if (i == j)
 165                                continue;
 166
 167                        match_pr = per_cpu(processors, j);
 168                        if (!match_pr)
 169                                continue;
 170
 171                        match_pthrottling = &(match_pr->throttling);
 172                        match_pdomain = &(match_pthrottling->domain_info);
 173                        if (match_pdomain->domain != pdomain->domain)
 174                                continue;
 175
 176                        /*
 177                         * If some CPUS have the same domain, they
 178                         * will have the same shared_cpu_map.
 179                         */
 180                        cpumask_copy(match_pthrottling->shared_cpu_map,
 181                                     pthrottling->shared_cpu_map);
 182                }
 183        }
 184
 185err_ret:
 186        free_cpumask_var(covered_cpus);
 187
 188        for_each_possible_cpu(i) {
 189                pr = per_cpu(processors, i);
 190                if (!pr)
 191                        continue;
 192
 193                /*
 194                 * Assume no coordination on any error parsing domain info.
 195                 * The coordination type will be forced as SW_ALL.
 196                 */
 197                if (retval) {
 198                        pthrottling = &(pr->throttling);
 199                        cpumask_clear(pthrottling->shared_cpu_map);
 200                        cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 201                        pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 202                }
 203        }
 204
 205        return retval;
 206}
 207
 208/*
 209 * Update the T-state coordination after the _TSD
 210 * data for all cpus is obtained.
 211 */
 212void acpi_processor_throttling_init(void)
 213{
 214        if (acpi_processor_update_tsd_coord()) {
 215                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 216                        "Assume no T-state coordination\n"));
 217        }
 218
 219        return;
 220}
 221
 222static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 223{
 224        struct throttling_tstate *p_tstate = data;
 225        struct acpi_processor *pr;
 226        unsigned int cpu ;
 227        int target_state;
 228        struct acpi_processor_limit *p_limit;
 229        struct acpi_processor_throttling *p_throttling;
 230
 231        cpu = p_tstate->cpu;
 232        pr = per_cpu(processors, cpu);
 233        if (!pr) {
 234                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 235                return 0;
 236        }
 237        if (!pr->flags.throttling) {
 238                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 239                                "unsupported on CPU %d\n", cpu));
 240                return 0;
 241        }
 242        target_state = p_tstate->target_state;
 243        p_throttling = &(pr->throttling);
 244        switch (event) {
 245        case THROTTLING_PRECHANGE:
 246                /*
 247                 * Prechange event is used to choose one proper t-state,
 248                 * which meets the limits of thermal, user and _TPC.
 249                 */
 250                p_limit = &pr->limit;
 251                if (p_limit->thermal.tx > target_state)
 252                        target_state = p_limit->thermal.tx;
 253                if (p_limit->user.tx > target_state)
 254                        target_state = p_limit->user.tx;
 255                if (pr->throttling_platform_limit > target_state)
 256                        target_state = pr->throttling_platform_limit;
 257                if (target_state >= p_throttling->state_count) {
 258                        printk(KERN_WARNING
 259                                "Exceed the limit of T-state \n");
 260                        target_state = p_throttling->state_count - 1;
 261                }
 262                p_tstate->target_state = target_state;
 263                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 264                                "target T-state of CPU %d is T%d\n",
 265                                cpu, target_state));
 266                break;
 267        case THROTTLING_POSTCHANGE:
 268                /*
 269                 * Postchange event is only used to update the
 270                 * T-state flag of acpi_processor_throttling.
 271                 */
 272                p_throttling->state = target_state;
 273                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 274                                "CPU %d is switched to T%d\n",
 275                                cpu, target_state));
 276                break;
 277        default:
 278                printk(KERN_WARNING
 279                        "Unsupported Throttling notifier event\n");
 280                break;
 281        }
 282
 283        return 0;
 284}
 285
 286/*
 287 * _TPC - Throttling Present Capabilities
 288 */
 289static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 290{
 291        acpi_status status = 0;
 292        unsigned long long tpc = 0;
 293
 294        if (!pr)
 295                return -EINVAL;
 296
 297        if (ignore_tpc)
 298                goto end;
 299
 300        status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 301        if (ACPI_FAILURE(status)) {
 302                if (status != AE_NOT_FOUND) {
 303                        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 304                }
 305                return -ENODEV;
 306        }
 307
 308end:
 309        pr->throttling_platform_limit = (int)tpc;
 310        return 0;
 311}
 312
 313int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 314{
 315        int result = 0;
 316        int throttling_limit;
 317        int current_state;
 318        struct acpi_processor_limit *limit;
 319        int target_state;
 320
 321        if (ignore_tpc)
 322                return 0;
 323
 324        result = acpi_processor_get_platform_limit(pr);
 325        if (result) {
 326                /* Throttling Limit is unsupported */
 327                return result;
 328        }
 329
 330        throttling_limit = pr->throttling_platform_limit;
 331        if (throttling_limit >= pr->throttling.state_count) {
 332                /* Uncorrect Throttling Limit */
 333                return -EINVAL;
 334        }
 335
 336        current_state = pr->throttling.state;
 337        if (current_state > throttling_limit) {
 338                /*
 339                 * The current state can meet the requirement of
 340                 * _TPC limit. But it is reasonable that OSPM changes
 341                 * t-states from high to low for better performance.
 342                 * Of course the limit condition of thermal
 343                 * and user should be considered.
 344                 */
 345                limit = &pr->limit;
 346                target_state = throttling_limit;
 347                if (limit->thermal.tx > target_state)
 348                        target_state = limit->thermal.tx;
 349                if (limit->user.tx > target_state)
 350                        target_state = limit->user.tx;
 351        } else if (current_state == throttling_limit) {
 352                /*
 353                 * Unnecessary to change the throttling state
 354                 */
 355                return 0;
 356        } else {
 357                /*
 358                 * If the current state is lower than the limit of _TPC, it
 359                 * will be forced to switch to the throttling state defined
 360                 * by throttling_platfor_limit.
 361                 * Because the previous state meets with the limit condition
 362                 * of thermal and user, it is unnecessary to check it again.
 363                 */
 364                target_state = throttling_limit;
 365        }
 366        return acpi_processor_set_throttling(pr, target_state, false);
 367}
 368
 369/*
 370 * This function is used to reevaluate whether the T-state is valid
 371 * after one CPU is onlined/offlined.
 372 * It is noted that it won't reevaluate the following properties for
 373 * the T-state.
 374 *      1. Control method.
 375 *      2. the number of supported T-state
 376 *      3. TSD domain
 377 */
 378void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 379                                        unsigned long action)
 380{
 381        int result = 0;
 382
 383        if (action == CPU_DEAD) {
 384                /* When one CPU is offline, the T-state throttling
 385                 * will be invalidated.
 386                 */
 387                pr->flags.throttling = 0;
 388                return;
 389        }
 390        /* the following is to recheck whether the T-state is valid for
 391         * the online CPU
 392         */
 393        if (!pr->throttling.state_count) {
 394                /* If the number of T-state is invalid, it is
 395                 * invalidated.
 396                 */
 397                pr->flags.throttling = 0;
 398                return;
 399        }
 400        pr->flags.throttling = 1;
 401
 402        /* Disable throttling (if enabled).  We'll let subsequent
 403         * policy (e.g.thermal) decide to lower performance if it
 404         * so chooses, but for now we'll crank up the speed.
 405         */
 406
 407        result = acpi_processor_get_throttling(pr);
 408        if (result)
 409                goto end;
 410
 411        if (pr->throttling.state) {
 412                result = acpi_processor_set_throttling(pr, 0, false);
 413                if (result)
 414                        goto end;
 415        }
 416
 417end:
 418        if (result)
 419                pr->flags.throttling = 0;
 420}
 421/*
 422 * _PTC - Processor Throttling Control (and status) register location
 423 */
 424static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 425{
 426        int result = 0;
 427        acpi_status status = 0;
 428        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 429        union acpi_object *ptc = NULL;
 430        union acpi_object obj = { 0 };
 431        struct acpi_processor_throttling *throttling;
 432
 433        status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 434        if (ACPI_FAILURE(status)) {
 435                if (status != AE_NOT_FOUND) {
 436                        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 437                }
 438                return -ENODEV;
 439        }
 440
 441        ptc = (union acpi_object *)buffer.pointer;
 442        if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 443            || (ptc->package.count != 2)) {
 444                printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 445                result = -EFAULT;
 446                goto end;
 447        }
 448
 449        /*
 450         * control_register
 451         */
 452
 453        obj = ptc->package.elements[0];
 454
 455        if ((obj.type != ACPI_TYPE_BUFFER)
 456            || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 457            || (obj.buffer.pointer == NULL)) {
 458                printk(KERN_ERR PREFIX
 459                       "Invalid _PTC data (control_register)\n");
 460                result = -EFAULT;
 461                goto end;
 462        }
 463        memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 464               sizeof(struct acpi_ptc_register));
 465
 466        /*
 467         * status_register
 468         */
 469
 470        obj = ptc->package.elements[1];
 471
 472        if ((obj.type != ACPI_TYPE_BUFFER)
 473            || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 474            || (obj.buffer.pointer == NULL)) {
 475                printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 476                result = -EFAULT;
 477                goto end;
 478        }
 479
 480        memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 481               sizeof(struct acpi_ptc_register));
 482
 483        throttling = &pr->throttling;
 484
 485        if ((throttling->control_register.bit_width +
 486                throttling->control_register.bit_offset) > 32) {
 487                printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 488                result = -EFAULT;
 489                goto end;
 490        }
 491
 492        if ((throttling->status_register.bit_width +
 493                throttling->status_register.bit_offset) > 32) {
 494                printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 495                result = -EFAULT;
 496                goto end;
 497        }
 498
 499      end:
 500        kfree(buffer.pointer);
 501
 502        return result;
 503}
 504
 505/*
 506 * _TSS - Throttling Supported States
 507 */
 508static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 509{
 510        int result = 0;
 511        acpi_status status = AE_OK;
 512        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 513        struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 514        struct acpi_buffer state = { 0, NULL };
 515        union acpi_object *tss = NULL;
 516        int i;
 517
 518        status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 519        if (ACPI_FAILURE(status)) {
 520                if (status != AE_NOT_FOUND) {
 521                        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 522                }
 523                return -ENODEV;
 524        }
 525
 526        tss = buffer.pointer;
 527        if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 528                printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 529                result = -EFAULT;
 530                goto end;
 531        }
 532
 533        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 534                          tss->package.count));
 535
 536        pr->throttling.state_count = tss->package.count;
 537        pr->throttling.states_tss =
 538            kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 539                    GFP_KERNEL);
 540        if (!pr->throttling.states_tss) {
 541                result = -ENOMEM;
 542                goto end;
 543        }
 544
 545        for (i = 0; i < pr->throttling.state_count; i++) {
 546
 547                struct acpi_processor_tx_tss *tx =
 548                    (struct acpi_processor_tx_tss *)&(pr->throttling.
 549                                                      states_tss[i]);
 550
 551                state.length = sizeof(struct acpi_processor_tx_tss);
 552                state.pointer = tx;
 553
 554                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 555
 556                status = acpi_extract_package(&(tss->package.elements[i]),
 557                                              &format, &state);
 558                if (ACPI_FAILURE(status)) {
 559                        ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 560                        result = -EFAULT;
 561                        kfree(pr->throttling.states_tss);
 562                        goto end;
 563                }
 564
 565                if (!tx->freqpercentage) {
 566                        printk(KERN_ERR PREFIX
 567                               "Invalid _TSS data: freq is zero\n");
 568                        result = -EFAULT;
 569                        kfree(pr->throttling.states_tss);
 570                        goto end;
 571                }
 572        }
 573
 574      end:
 575        kfree(buffer.pointer);
 576
 577        return result;
 578}
 579
 580/*
 581 * _TSD - T-State Dependencies
 582 */
 583static int acpi_processor_get_tsd(struct acpi_processor *pr)
 584{
 585        int result = 0;
 586        acpi_status status = AE_OK;
 587        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 588        struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 589        struct acpi_buffer state = { 0, NULL };
 590        union acpi_object *tsd = NULL;
 591        struct acpi_tsd_package *pdomain;
 592        struct acpi_processor_throttling *pthrottling;
 593
 594        pthrottling = &pr->throttling;
 595        pthrottling->tsd_valid_flag = 0;
 596
 597        status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 598        if (ACPI_FAILURE(status)) {
 599                if (status != AE_NOT_FOUND) {
 600                        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 601                }
 602                return -ENODEV;
 603        }
 604
 605        tsd = buffer.pointer;
 606        if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 607                printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 608                result = -EFAULT;
 609                goto end;
 610        }
 611
 612        if (tsd->package.count != 1) {
 613                printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 614                result = -EFAULT;
 615                goto end;
 616        }
 617
 618        pdomain = &(pr->throttling.domain_info);
 619
 620        state.length = sizeof(struct acpi_tsd_package);
 621        state.pointer = pdomain;
 622
 623        status = acpi_extract_package(&(tsd->package.elements[0]),
 624                                      &format, &state);
 625        if (ACPI_FAILURE(status)) {
 626                printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 627                result = -EFAULT;
 628                goto end;
 629        }
 630
 631        if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 632                printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 633                result = -EFAULT;
 634                goto end;
 635        }
 636
 637        if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 638                printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 639                result = -EFAULT;
 640                goto end;
 641        }
 642
 643        pthrottling = &pr->throttling;
 644        pthrottling->tsd_valid_flag = 1;
 645        pthrottling->shared_type = pdomain->coord_type;
 646        cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 647        /*
 648         * If the coordination type is not defined in ACPI spec,
 649         * the tsd_valid_flag will be clear and coordination type
 650         * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 651         */
 652        if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 653                pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 654                pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 655                pthrottling->tsd_valid_flag = 0;
 656                pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 657        }
 658
 659      end:
 660        kfree(buffer.pointer);
 661        return result;
 662}
 663
 664/* --------------------------------------------------------------------------
 665                              Throttling Control
 666   -------------------------------------------------------------------------- */
 667static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 668{
 669        int state = 0;
 670        u32 value = 0;
 671        u32 duty_mask = 0;
 672        u32 duty_value = 0;
 673
 674        if (!pr)
 675                return -EINVAL;
 676
 677        if (!pr->flags.throttling)
 678                return -ENODEV;
 679
 680        pr->throttling.state = 0;
 681
 682        duty_mask = pr->throttling.state_count - 1;
 683
 684        duty_mask <<= pr->throttling.duty_offset;
 685
 686        local_irq_disable();
 687
 688        value = inl(pr->throttling.address);
 689
 690        /*
 691         * Compute the current throttling state when throttling is enabled
 692         * (bit 4 is on).
 693         */
 694        if (value & 0x10) {
 695                duty_value = value & duty_mask;
 696                duty_value >>= pr->throttling.duty_offset;
 697
 698                if (duty_value)
 699                        state = pr->throttling.state_count - duty_value;
 700        }
 701
 702        pr->throttling.state = state;
 703
 704        local_irq_enable();
 705
 706        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 707                          "Throttling state is T%d (%d%% throttling applied)\n",
 708                          state, pr->throttling.states[state].performance));
 709
 710        return 0;
 711}
 712
 713#ifdef CONFIG_X86
 714static int acpi_throttling_rdmsr(u64 *value)
 715{
 716        u64 msr_high, msr_low;
 717        u64 msr = 0;
 718        int ret = -1;
 719
 720        if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 721                !this_cpu_has(X86_FEATURE_ACPI)) {
 722                printk(KERN_ERR PREFIX
 723                        "HARDWARE addr space,NOT supported yet\n");
 724        } else {
 725                msr_low = 0;
 726                msr_high = 0;
 727                rdmsr_safe(MSR_IA32_THERM_CONTROL,
 728                        (u32 *)&msr_low , (u32 *) &msr_high);
 729                msr = (msr_high << 32) | msr_low;
 730                *value = (u64) msr;
 731                ret = 0;
 732        }
 733        return ret;
 734}
 735
 736static int acpi_throttling_wrmsr(u64 value)
 737{
 738        int ret = -1;
 739        u64 msr;
 740
 741        if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 742                !this_cpu_has(X86_FEATURE_ACPI)) {
 743                printk(KERN_ERR PREFIX
 744                        "HARDWARE addr space,NOT supported yet\n");
 745        } else {
 746                msr = value;
 747                wrmsr_safe(MSR_IA32_THERM_CONTROL,
 748                        msr & 0xffffffff, msr >> 32);
 749                ret = 0;
 750        }
 751        return ret;
 752}
 753#else
 754static int acpi_throttling_rdmsr(u64 *value)
 755{
 756        printk(KERN_ERR PREFIX
 757                "HARDWARE addr space,NOT supported yet\n");
 758        return -1;
 759}
 760
 761static int acpi_throttling_wrmsr(u64 value)
 762{
 763        printk(KERN_ERR PREFIX
 764                "HARDWARE addr space,NOT supported yet\n");
 765        return -1;
 766}
 767#endif
 768
 769static int acpi_read_throttling_status(struct acpi_processor *pr,
 770                                        u64 *value)
 771{
 772        u32 bit_width, bit_offset;
 773        u32 ptc_value;
 774        u64 ptc_mask;
 775        struct acpi_processor_throttling *throttling;
 776        int ret = -1;
 777
 778        throttling = &pr->throttling;
 779        switch (throttling->status_register.space_id) {
 780        case ACPI_ADR_SPACE_SYSTEM_IO:
 781                bit_width = throttling->status_register.bit_width;
 782                bit_offset = throttling->status_register.bit_offset;
 783
 784                acpi_os_read_port((acpi_io_address) throttling->status_register.
 785                                  address, &ptc_value,
 786                                  (u32) (bit_width + bit_offset));
 787                ptc_mask = (1 << bit_width) - 1;
 788                *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 789                ret = 0;
 790                break;
 791        case ACPI_ADR_SPACE_FIXED_HARDWARE:
 792                ret = acpi_throttling_rdmsr(value);
 793                break;
 794        default:
 795                printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 796                       (u32) (throttling->status_register.space_id));
 797        }
 798        return ret;
 799}
 800
 801static int acpi_write_throttling_state(struct acpi_processor *pr,
 802                                u64 value)
 803{
 804        u32 bit_width, bit_offset;
 805        u64 ptc_value;
 806        u64 ptc_mask;
 807        struct acpi_processor_throttling *throttling;
 808        int ret = -1;
 809
 810        throttling = &pr->throttling;
 811        switch (throttling->control_register.space_id) {
 812        case ACPI_ADR_SPACE_SYSTEM_IO:
 813                bit_width = throttling->control_register.bit_width;
 814                bit_offset = throttling->control_register.bit_offset;
 815                ptc_mask = (1 << bit_width) - 1;
 816                ptc_value = value & ptc_mask;
 817
 818                acpi_os_write_port((acpi_io_address) throttling->
 819                                        control_register.address,
 820                                        (u32) (ptc_value << bit_offset),
 821                                        (u32) (bit_width + bit_offset));
 822                ret = 0;
 823                break;
 824        case ACPI_ADR_SPACE_FIXED_HARDWARE:
 825                ret = acpi_throttling_wrmsr(value);
 826                break;
 827        default:
 828                printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 829                       (u32) (throttling->control_register.space_id));
 830        }
 831        return ret;
 832}
 833
 834static int acpi_get_throttling_state(struct acpi_processor *pr,
 835                                u64 value)
 836{
 837        int i;
 838
 839        for (i = 0; i < pr->throttling.state_count; i++) {
 840                struct acpi_processor_tx_tss *tx =
 841                    (struct acpi_processor_tx_tss *)&(pr->throttling.
 842                                                      states_tss[i]);
 843                if (tx->control == value)
 844                        return i;
 845        }
 846        return -1;
 847}
 848
 849static int acpi_get_throttling_value(struct acpi_processor *pr,
 850                        int state, u64 *value)
 851{
 852        int ret = -1;
 853
 854        if (state >= 0 && state <= pr->throttling.state_count) {
 855                struct acpi_processor_tx_tss *tx =
 856                    (struct acpi_processor_tx_tss *)&(pr->throttling.
 857                                                      states_tss[state]);
 858                *value = tx->control;
 859                ret = 0;
 860        }
 861        return ret;
 862}
 863
 864static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 865{
 866        int state = 0;
 867        int ret;
 868        u64 value;
 869
 870        if (!pr)
 871                return -EINVAL;
 872
 873        if (!pr->flags.throttling)
 874                return -ENODEV;
 875
 876        pr->throttling.state = 0;
 877
 878        value = 0;
 879        ret = acpi_read_throttling_status(pr, &value);
 880        if (ret >= 0) {
 881                state = acpi_get_throttling_state(pr, value);
 882                if (state == -1) {
 883                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 884                                "Invalid throttling state, reset\n"));
 885                        state = 0;
 886                        ret = acpi_processor_set_throttling(pr, state, true);
 887                        if (ret)
 888                                return ret;
 889                }
 890                pr->throttling.state = state;
 891        }
 892
 893        return 0;
 894}
 895
 896static int acpi_processor_get_throttling(struct acpi_processor *pr)
 897{
 898        cpumask_var_t saved_mask;
 899        int ret;
 900
 901        if (!pr)
 902                return -EINVAL;
 903
 904        if (!pr->flags.throttling)
 905                return -ENODEV;
 906
 907        if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 908                return -ENOMEM;
 909
 910        /*
 911         * Migrate task to the cpu pointed by pr.
 912         */
 913        cpumask_copy(saved_mask, &current->cpus_allowed);
 914        /* FIXME: use work_on_cpu() */
 915        if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
 916                /* Can't migrate to the target pr->id CPU. Exit */
 917                free_cpumask_var(saved_mask);
 918                return -ENODEV;
 919        }
 920        ret = pr->throttling.acpi_processor_get_throttling(pr);
 921        /* restore the previous state */
 922        set_cpus_allowed_ptr(current, saved_mask);
 923        free_cpumask_var(saved_mask);
 924
 925        return ret;
 926}
 927
 928static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 929{
 930        int i, step;
 931
 932        if (!pr->throttling.address) {
 933                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 934                return -EINVAL;
 935        } else if (!pr->throttling.duty_width) {
 936                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 937                return -EINVAL;
 938        }
 939        /* TBD: Support duty_cycle values that span bit 4. */
 940        else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 941                printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 942                return -EINVAL;
 943        }
 944
 945        pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 946
 947        /*
 948         * Compute state values. Note that throttling displays a linear power
 949         * performance relationship (at 50% performance the CPU will consume
 950         * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 951         */
 952
 953        step = (1000 / pr->throttling.state_count);
 954
 955        for (i = 0; i < pr->throttling.state_count; i++) {
 956                pr->throttling.states[i].performance = 1000 - step * i;
 957                pr->throttling.states[i].power = 1000 - step * i;
 958        }
 959        return 0;
 960}
 961
 962static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 963                                              int state, bool force)
 964{
 965        u32 value = 0;
 966        u32 duty_mask = 0;
 967        u32 duty_value = 0;
 968
 969        if (!pr)
 970                return -EINVAL;
 971
 972        if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 973                return -EINVAL;
 974
 975        if (!pr->flags.throttling)
 976                return -ENODEV;
 977
 978        if (!force && (state == pr->throttling.state))
 979                return 0;
 980
 981        if (state < pr->throttling_platform_limit)
 982                return -EPERM;
 983        /*
 984         * Calculate the duty_value and duty_mask.
 985         */
 986        if (state) {
 987                duty_value = pr->throttling.state_count - state;
 988
 989                duty_value <<= pr->throttling.duty_offset;
 990
 991                /* Used to clear all duty_value bits */
 992                duty_mask = pr->throttling.state_count - 1;
 993
 994                duty_mask <<= acpi_gbl_FADT.duty_offset;
 995                duty_mask = ~duty_mask;
 996        }
 997
 998        local_irq_disable();
 999
1000        /*
1001         * Disable throttling by writing a 0 to bit 4.  Note that we must
1002         * turn it off before you can change the duty_value.
1003         */
1004        value = inl(pr->throttling.address);
1005        if (value & 0x10) {
1006                value &= 0xFFFFFFEF;
1007                outl(value, pr->throttling.address);
1008        }
1009
1010        /*
1011         * Write the new duty_value and then enable throttling.  Note
1012         * that a state value of 0 leaves throttling disabled.
1013         */
1014        if (state) {
1015                value &= duty_mask;
1016                value |= duty_value;
1017                outl(value, pr->throttling.address);
1018
1019                value |= 0x00000010;
1020                outl(value, pr->throttling.address);
1021        }
1022
1023        pr->throttling.state = state;
1024
1025        local_irq_enable();
1026
1027        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1028                          "Throttling state set to T%d (%d%%)\n", state,
1029                          (pr->throttling.states[state].performance ? pr->
1030                           throttling.states[state].performance / 10 : 0)));
1031
1032        return 0;
1033}
1034
1035static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1036                                             int state, bool force)
1037{
1038        int ret;
1039        u64 value;
1040
1041        if (!pr)
1042                return -EINVAL;
1043
1044        if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1045                return -EINVAL;
1046
1047        if (!pr->flags.throttling)
1048                return -ENODEV;
1049
1050        if (!force && (state == pr->throttling.state))
1051                return 0;
1052
1053        if (state < pr->throttling_platform_limit)
1054                return -EPERM;
1055
1056        value = 0;
1057        ret = acpi_get_throttling_value(pr, state, &value);
1058        if (ret >= 0) {
1059                acpi_write_throttling_state(pr, value);
1060                pr->throttling.state = state;
1061        }
1062
1063        return 0;
1064}
1065
1066int acpi_processor_set_throttling(struct acpi_processor *pr,
1067                                                int state, bool force)
1068{
1069        cpumask_var_t saved_mask;
1070        int ret = 0;
1071        unsigned int i;
1072        struct acpi_processor *match_pr;
1073        struct acpi_processor_throttling *p_throttling;
1074        struct throttling_tstate t_state;
1075        cpumask_var_t online_throttling_cpus;
1076
1077        if (!pr)
1078                return -EINVAL;
1079
1080        if (!pr->flags.throttling)
1081                return -ENODEV;
1082
1083        if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1084                return -EINVAL;
1085
1086        if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1087                return -ENOMEM;
1088
1089        if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1090                free_cpumask_var(saved_mask);
1091                return -ENOMEM;
1092        }
1093
1094        if (cpu_is_offline(pr->id)) {
1095                /*
1096                 * the cpu pointed by pr->id is offline. Unnecessary to change
1097                 * the throttling state any more.
1098                 */
1099                return -ENODEV;
1100        }
1101
1102        cpumask_copy(saved_mask, &current->cpus_allowed);
1103        t_state.target_state = state;
1104        p_throttling = &(pr->throttling);
1105        cpumask_and(online_throttling_cpus, cpu_online_mask,
1106                    p_throttling->shared_cpu_map);
1107        /*
1108         * The throttling notifier will be called for every
1109         * affected cpu in order to get one proper T-state.
1110         * The notifier event is THROTTLING_PRECHANGE.
1111         */
1112        for_each_cpu(i, online_throttling_cpus) {
1113                t_state.cpu = i;
1114                acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1115                                                        &t_state);
1116        }
1117        /*
1118         * The function of acpi_processor_set_throttling will be called
1119         * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1120         * it is necessary to call it for every affected cpu. Otherwise
1121         * it can be called only for the cpu pointed by pr.
1122         */
1123        if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1124                /* FIXME: use work_on_cpu() */
1125                if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
1126                        /* Can't migrate to the pr->id CPU. Exit */
1127                        ret = -ENODEV;
1128                        goto exit;
1129                }
1130                ret = p_throttling->acpi_processor_set_throttling(pr,
1131                                                t_state.target_state, force);
1132        } else {
1133                /*
1134                 * When the T-state coordination is SW_ALL or HW_ALL,
1135                 * it is necessary to set T-state for every affected
1136                 * cpus.
1137                 */
1138                for_each_cpu(i, online_throttling_cpus) {
1139                        match_pr = per_cpu(processors, i);
1140                        /*
1141                         * If the pointer is invalid, we will report the
1142                         * error message and continue.
1143                         */
1144                        if (!match_pr) {
1145                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1146                                        "Invalid Pointer for CPU %d\n", i));
1147                                continue;
1148                        }
1149                        /*
1150                         * If the throttling control is unsupported on CPU i,
1151                         * we will report the error message and continue.
1152                         */
1153                        if (!match_pr->flags.throttling) {
1154                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1155                                        "Throttling Control is unsupported "
1156                                        "on CPU %d\n", i));
1157                                continue;
1158                        }
1159                        t_state.cpu = i;
1160                        /* FIXME: use work_on_cpu() */
1161                        if (set_cpus_allowed_ptr(current, cpumask_of(i)))
1162                                continue;
1163                        ret = match_pr->throttling.
1164                                acpi_processor_set_throttling(
1165                                match_pr, t_state.target_state, force);
1166                }
1167        }
1168        /*
1169         * After the set_throttling is called, the
1170         * throttling notifier is called for every
1171         * affected cpu to update the T-states.
1172         * The notifier event is THROTTLING_POSTCHANGE
1173         */
1174        for_each_cpu(i, online_throttling_cpus) {
1175                t_state.cpu = i;
1176                acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1177                                                        &t_state);
1178        }
1179        /* restore the previous state */
1180        /* FIXME: use work_on_cpu() */
1181        set_cpus_allowed_ptr(current, saved_mask);
1182exit:
1183        free_cpumask_var(online_throttling_cpus);
1184        free_cpumask_var(saved_mask);
1185        return ret;
1186}
1187
1188int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1189{
1190        int result = 0;
1191        struct acpi_processor_throttling *pthrottling;
1192
1193        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1194                          "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1195                          pr->throttling.address,
1196                          pr->throttling.duty_offset,
1197                          pr->throttling.duty_width));
1198
1199        /*
1200         * Evaluate _PTC, _TSS and _TPC
1201         * They must all be present or none of them can be used.
1202         */
1203        if (acpi_processor_get_throttling_control(pr) ||
1204                acpi_processor_get_throttling_states(pr) ||
1205                acpi_processor_get_platform_limit(pr))
1206        {
1207                pr->throttling.acpi_processor_get_throttling =
1208                    &acpi_processor_get_throttling_fadt;
1209                pr->throttling.acpi_processor_set_throttling =
1210                    &acpi_processor_set_throttling_fadt;
1211                if (acpi_processor_get_fadt_info(pr))
1212                        return 0;
1213        } else {
1214                pr->throttling.acpi_processor_get_throttling =
1215                    &acpi_processor_get_throttling_ptc;
1216                pr->throttling.acpi_processor_set_throttling =
1217                    &acpi_processor_set_throttling_ptc;
1218        }
1219
1220        /*
1221         * If TSD package for one CPU can't be parsed successfully, it means
1222         * that this CPU will have no coordination with other CPUs.
1223         */
1224        if (acpi_processor_get_tsd(pr)) {
1225                pthrottling = &pr->throttling;
1226                pthrottling->tsd_valid_flag = 0;
1227                cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1228                pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1229        }
1230
1231        /*
1232         * PIIX4 Errata: We don't support throttling on the original PIIX4.
1233         * This shouldn't be an issue as few (if any) mobile systems ever
1234         * used this part.
1235         */
1236        if (errata.piix4.throttle) {
1237                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1238                                  "Throttling not supported on PIIX4 A- or B-step\n"));
1239                return 0;
1240        }
1241
1242        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1243                          pr->throttling.state_count));
1244
1245        pr->flags.throttling = 1;
1246
1247        /*
1248         * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1249         * thermal) decide to lower performance if it so chooses, but for now
1250         * we'll crank up the speed.
1251         */
1252
1253        result = acpi_processor_get_throttling(pr);
1254        if (result)
1255                goto end;
1256
1257        if (pr->throttling.state) {
1258                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1259                                  "Disabling throttling (was T%d)\n",
1260                                  pr->throttling.state));
1261                result = acpi_processor_set_throttling(pr, 0, false);
1262                if (result)
1263                        goto end;
1264        }
1265
1266      end:
1267        if (result)
1268                pr->flags.throttling = 0;
1269
1270        return result;
1271}
1272
1273
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