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