linux/drivers/cpufreq/acpi-cpufreq.c
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   1/*
   2 * acpi-cpufreq.c - ACPI Processor P-States 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) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   7 *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8 *
   9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10 *
  11 *  This program is free software; you can redistribute it and/or modify
  12 *  it under the terms of the GNU General Public License as published by
  13 *  the Free Software Foundation; either version 2 of the License, or (at
  14 *  your option) any later version.
  15 *
  16 *  This program is distributed in the hope that it will be useful, but
  17 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 *  General Public License for more details.
  20 *
  21 *  You should have received a copy of the GNU General Public License along
  22 *  with this program; if not, write to the Free Software Foundation, Inc.,
  23 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  24 *
  25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26 */
  27
  28#include <linux/kernel.h>
  29#include <linux/module.h>
  30#include <linux/init.h>
  31#include <linux/smp.h>
  32#include <linux/sched.h>
  33#include <linux/cpufreq.h>
  34#include <linux/compiler.h>
  35#include <linux/dmi.h>
  36#include <linux/slab.h>
  37
  38#include <linux/acpi.h>
  39#include <linux/io.h>
  40#include <linux/delay.h>
  41#include <linux/uaccess.h>
  42
  43#include <acpi/processor.h>
  44
  45#include <asm/msr.h>
  46#include <asm/processor.h>
  47#include <asm/cpufeature.h>
  48
  49MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  50MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  51MODULE_LICENSE("GPL");
  52
  53#define PFX "acpi-cpufreq: "
  54
  55enum {
  56        UNDEFINED_CAPABLE = 0,
  57        SYSTEM_INTEL_MSR_CAPABLE,
  58        SYSTEM_AMD_MSR_CAPABLE,
  59        SYSTEM_IO_CAPABLE,
  60};
  61
  62#define INTEL_MSR_RANGE         (0xffff)
  63#define AMD_MSR_RANGE           (0x7)
  64
  65#define MSR_K7_HWCR_CPB_DIS     (1ULL << 25)
  66
  67struct acpi_cpufreq_data {
  68        struct acpi_processor_performance *acpi_data;
  69        struct cpufreq_frequency_table *freq_table;
  70        unsigned int resume;
  71        unsigned int cpu_feature;
  72        cpumask_var_t freqdomain_cpus;
  73};
  74
  75static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
  76
  77/* acpi_perf_data is a pointer to percpu data. */
  78static struct acpi_processor_performance __percpu *acpi_perf_data;
  79
  80static struct cpufreq_driver acpi_cpufreq_driver;
  81
  82static unsigned int acpi_pstate_strict;
  83static bool boost_enabled, boost_supported;
  84static struct msr __percpu *msrs;
  85
  86static bool boost_state(unsigned int cpu)
  87{
  88        u32 lo, hi;
  89        u64 msr;
  90
  91        switch (boot_cpu_data.x86_vendor) {
  92        case X86_VENDOR_INTEL:
  93                rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
  94                msr = lo | ((u64)hi << 32);
  95                return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
  96        case X86_VENDOR_AMD:
  97                rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
  98                msr = lo | ((u64)hi << 32);
  99                return !(msr & MSR_K7_HWCR_CPB_DIS);
 100        }
 101        return false;
 102}
 103
 104static void boost_set_msrs(bool enable, const struct cpumask *cpumask)
 105{
 106        u32 cpu;
 107        u32 msr_addr;
 108        u64 msr_mask;
 109
 110        switch (boot_cpu_data.x86_vendor) {
 111        case X86_VENDOR_INTEL:
 112                msr_addr = MSR_IA32_MISC_ENABLE;
 113                msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
 114                break;
 115        case X86_VENDOR_AMD:
 116                msr_addr = MSR_K7_HWCR;
 117                msr_mask = MSR_K7_HWCR_CPB_DIS;
 118                break;
 119        default:
 120                return;
 121        }
 122
 123        rdmsr_on_cpus(cpumask, msr_addr, msrs);
 124
 125        for_each_cpu(cpu, cpumask) {
 126                struct msr *reg = per_cpu_ptr(msrs, cpu);
 127                if (enable)
 128                        reg->q &= ~msr_mask;
 129                else
 130                        reg->q |= msr_mask;
 131        }
 132
 133        wrmsr_on_cpus(cpumask, msr_addr, msrs);
 134}
 135
 136static ssize_t _store_boost(const char *buf, size_t count)
 137{
 138        int ret;
 139        unsigned long val = 0;
 140
 141        if (!boost_supported)
 142                return -EINVAL;
 143
 144        ret = kstrtoul(buf, 10, &val);
 145        if (ret || (val > 1))
 146                return -EINVAL;
 147
 148        if ((val && boost_enabled) || (!val && !boost_enabled))
 149                return count;
 150
 151        get_online_cpus();
 152
 153        boost_set_msrs(val, cpu_online_mask);
 154
 155        put_online_cpus();
 156
 157        boost_enabled = val;
 158        pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
 159
 160        return count;
 161}
 162
 163static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr,
 164                                  const char *buf, size_t count)
 165{
 166        return _store_boost(buf, count);
 167}
 168
 169static ssize_t show_global_boost(struct kobject *kobj,
 170                                 struct attribute *attr, char *buf)
 171{
 172        return sprintf(buf, "%u\n", boost_enabled);
 173}
 174
 175static struct global_attr global_boost = __ATTR(boost, 0644,
 176                                                show_global_boost,
 177                                                store_global_boost);
 178
 179static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
 180{
 181        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 182
 183        return cpufreq_show_cpus(data->freqdomain_cpus, buf);
 184}
 185
 186cpufreq_freq_attr_ro(freqdomain_cpus);
 187
 188#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
 189static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
 190                         size_t count)
 191{
 192        return _store_boost(buf, count);
 193}
 194
 195static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
 196{
 197        return sprintf(buf, "%u\n", boost_enabled);
 198}
 199
 200cpufreq_freq_attr_rw(cpb);
 201#endif
 202
 203static int check_est_cpu(unsigned int cpuid)
 204{
 205        struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
 206
 207        return cpu_has(cpu, X86_FEATURE_EST);
 208}
 209
 210static int check_amd_hwpstate_cpu(unsigned int cpuid)
 211{
 212        struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
 213
 214        return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
 215}
 216
 217static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
 218{
 219        struct acpi_processor_performance *perf;
 220        int i;
 221
 222        perf = data->acpi_data;
 223
 224        for (i = 0; i < perf->state_count; i++) {
 225                if (value == perf->states[i].status)
 226                        return data->freq_table[i].frequency;
 227        }
 228        return 0;
 229}
 230
 231static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 232{
 233        int i;
 234        struct acpi_processor_performance *perf;
 235
 236        if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
 237                msr &= AMD_MSR_RANGE;
 238        else
 239                msr &= INTEL_MSR_RANGE;
 240
 241        perf = data->acpi_data;
 242
 243        for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 244                if (msr == perf->states[data->freq_table[i].driver_data].status)
 245                        return data->freq_table[i].frequency;
 246        }
 247        return data->freq_table[0].frequency;
 248}
 249
 250static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 251{
 252        switch (data->cpu_feature) {
 253        case SYSTEM_INTEL_MSR_CAPABLE:
 254        case SYSTEM_AMD_MSR_CAPABLE:
 255                return extract_msr(val, data);
 256        case SYSTEM_IO_CAPABLE:
 257                return extract_io(val, data);
 258        default:
 259                return 0;
 260        }
 261}
 262
 263struct msr_addr {
 264        u32 reg;
 265};
 266
 267struct io_addr {
 268        u16 port;
 269        u8 bit_width;
 270};
 271
 272struct drv_cmd {
 273        unsigned int type;
 274        const struct cpumask *mask;
 275        union {
 276                struct msr_addr msr;
 277                struct io_addr io;
 278        } addr;
 279        u32 val;
 280};
 281
 282/* Called via smp_call_function_single(), on the target CPU */
 283static void do_drv_read(void *_cmd)
 284{
 285        struct drv_cmd *cmd = _cmd;
 286        u32 h;
 287
 288        switch (cmd->type) {
 289        case SYSTEM_INTEL_MSR_CAPABLE:
 290        case SYSTEM_AMD_MSR_CAPABLE:
 291                rdmsr(cmd->addr.msr.reg, cmd->val, h);
 292                break;
 293        case SYSTEM_IO_CAPABLE:
 294                acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 295                                &cmd->val,
 296                                (u32)cmd->addr.io.bit_width);
 297                break;
 298        default:
 299                break;
 300        }
 301}
 302
 303/* Called via smp_call_function_many(), on the target CPUs */
 304static void do_drv_write(void *_cmd)
 305{
 306        struct drv_cmd *cmd = _cmd;
 307        u32 lo, hi;
 308
 309        switch (cmd->type) {
 310        case SYSTEM_INTEL_MSR_CAPABLE:
 311                rdmsr(cmd->addr.msr.reg, lo, hi);
 312                lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
 313                wrmsr(cmd->addr.msr.reg, lo, hi);
 314                break;
 315        case SYSTEM_AMD_MSR_CAPABLE:
 316                wrmsr(cmd->addr.msr.reg, cmd->val, 0);
 317                break;
 318        case SYSTEM_IO_CAPABLE:
 319                acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 320                                cmd->val,
 321                                (u32)cmd->addr.io.bit_width);
 322                break;
 323        default:
 324                break;
 325        }
 326}
 327
 328static void drv_read(struct drv_cmd *cmd)
 329{
 330        int err;
 331        cmd->val = 0;
 332
 333        err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
 334        WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
 335}
 336
 337static void drv_write(struct drv_cmd *cmd)
 338{
 339        int this_cpu;
 340
 341        this_cpu = get_cpu();
 342        if (cpumask_test_cpu(this_cpu, cmd->mask))
 343                do_drv_write(cmd);
 344        smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
 345        put_cpu();
 346}
 347
 348static u32 get_cur_val(const struct cpumask *mask)
 349{
 350        struct acpi_processor_performance *perf;
 351        struct drv_cmd cmd;
 352
 353        if (unlikely(cpumask_empty(mask)))
 354                return 0;
 355
 356        switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
 357        case SYSTEM_INTEL_MSR_CAPABLE:
 358                cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 359                cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 360                break;
 361        case SYSTEM_AMD_MSR_CAPABLE:
 362                cmd.type = SYSTEM_AMD_MSR_CAPABLE;
 363                cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
 364                break;
 365        case SYSTEM_IO_CAPABLE:
 366                cmd.type = SYSTEM_IO_CAPABLE;
 367                perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
 368                cmd.addr.io.port = perf->control_register.address;
 369                cmd.addr.io.bit_width = perf->control_register.bit_width;
 370                break;
 371        default:
 372                return 0;
 373        }
 374
 375        cmd.mask = mask;
 376        drv_read(&cmd);
 377
 378        pr_debug("get_cur_val = %u\n", cmd.val);
 379
 380        return cmd.val;
 381}
 382
 383static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 384{
 385        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
 386        unsigned int freq;
 387        unsigned int cached_freq;
 388
 389        pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
 390
 391        if (unlikely(data == NULL ||
 392                     data->acpi_data == NULL || data->freq_table == NULL)) {
 393                return 0;
 394        }
 395
 396        cached_freq = data->freq_table[data->acpi_data->state].frequency;
 397        freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
 398        if (freq != cached_freq) {
 399                /*
 400                 * The dreaded BIOS frequency change behind our back.
 401                 * Force set the frequency on next target call.
 402                 */
 403                data->resume = 1;
 404        }
 405
 406        pr_debug("cur freq = %u\n", freq);
 407
 408        return freq;
 409}
 410
 411static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
 412                                struct acpi_cpufreq_data *data)
 413{
 414        unsigned int cur_freq;
 415        unsigned int i;
 416
 417        for (i = 0; i < 100; i++) {
 418                cur_freq = extract_freq(get_cur_val(mask), data);
 419                if (cur_freq == freq)
 420                        return 1;
 421                udelay(10);
 422        }
 423        return 0;
 424}
 425
 426static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 427                               unsigned int target_freq, unsigned int relation)
 428{
 429        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 430        struct acpi_processor_performance *perf;
 431        struct cpufreq_freqs freqs;
 432        struct drv_cmd cmd;
 433        unsigned int next_state = 0; /* Index into freq_table */
 434        unsigned int next_perf_state = 0; /* Index into perf table */
 435        int result = 0;
 436
 437        pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 438
 439        if (unlikely(data == NULL ||
 440             data->acpi_data == NULL || data->freq_table == NULL)) {
 441                return -ENODEV;
 442        }
 443
 444        perf = data->acpi_data;
 445        result = cpufreq_frequency_table_target(policy,
 446                                                data->freq_table,
 447                                                target_freq,
 448                                                relation, &next_state);
 449        if (unlikely(result)) {
 450                result = -ENODEV;
 451                goto out;
 452        }
 453
 454        next_perf_state = data->freq_table[next_state].driver_data;
 455        if (perf->state == next_perf_state) {
 456                if (unlikely(data->resume)) {
 457                        pr_debug("Called after resume, resetting to P%d\n",
 458                                next_perf_state);
 459                        data->resume = 0;
 460                } else {
 461                        pr_debug("Already at target state (P%d)\n",
 462                                next_perf_state);
 463                        goto out;
 464                }
 465        }
 466
 467        switch (data->cpu_feature) {
 468        case SYSTEM_INTEL_MSR_CAPABLE:
 469                cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 470                cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 471                cmd.val = (u32) perf->states[next_perf_state].control;
 472                break;
 473        case SYSTEM_AMD_MSR_CAPABLE:
 474                cmd.type = SYSTEM_AMD_MSR_CAPABLE;
 475                cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
 476                cmd.val = (u32) perf->states[next_perf_state].control;
 477                break;
 478        case SYSTEM_IO_CAPABLE:
 479                cmd.type = SYSTEM_IO_CAPABLE;
 480                cmd.addr.io.port = perf->control_register.address;
 481                cmd.addr.io.bit_width = perf->control_register.bit_width;
 482                cmd.val = (u32) perf->states[next_perf_state].control;
 483                break;
 484        default:
 485                result = -ENODEV;
 486                goto out;
 487        }
 488
 489        /* cpufreq holds the hotplug lock, so we are safe from here on */
 490        if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 491                cmd.mask = policy->cpus;
 492        else
 493                cmd.mask = cpumask_of(policy->cpu);
 494
 495        freqs.old = perf->states[perf->state].core_frequency * 1000;
 496        freqs.new = data->freq_table[next_state].frequency;
 497        cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 498
 499        drv_write(&cmd);
 500
 501        if (acpi_pstate_strict) {
 502                if (!check_freqs(cmd.mask, freqs.new, data)) {
 503                        pr_debug("acpi_cpufreq_target failed (%d)\n",
 504                                policy->cpu);
 505                        result = -EAGAIN;
 506                        freqs.new = freqs.old;
 507                }
 508        }
 509
 510        cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
 511
 512        if (!result)
 513                perf->state = next_perf_state;
 514
 515out:
 516        return result;
 517}
 518
 519static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 520{
 521        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 522
 523        pr_debug("acpi_cpufreq_verify\n");
 524
 525        return cpufreq_frequency_table_verify(policy, data->freq_table);
 526}
 527
 528static unsigned long
 529acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 530{
 531        struct acpi_processor_performance *perf = data->acpi_data;
 532
 533        if (cpu_khz) {
 534                /* search the closest match to cpu_khz */
 535                unsigned int i;
 536                unsigned long freq;
 537                unsigned long freqn = perf->states[0].core_frequency * 1000;
 538
 539                for (i = 0; i < (perf->state_count-1); i++) {
 540                        freq = freqn;
 541                        freqn = perf->states[i+1].core_frequency * 1000;
 542                        if ((2 * cpu_khz) > (freqn + freq)) {
 543                                perf->state = i;
 544                                return freq;
 545                        }
 546                }
 547                perf->state = perf->state_count-1;
 548                return freqn;
 549        } else {
 550                /* assume CPU is at P0... */
 551                perf->state = 0;
 552                return perf->states[0].core_frequency * 1000;
 553        }
 554}
 555
 556static void free_acpi_perf_data(void)
 557{
 558        unsigned int i;
 559
 560        /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 561        for_each_possible_cpu(i)
 562                free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 563                                 ->shared_cpu_map);
 564        free_percpu(acpi_perf_data);
 565}
 566
 567static int boost_notify(struct notifier_block *nb, unsigned long action,
 568                      void *hcpu)
 569{
 570        unsigned cpu = (long)hcpu;
 571        const struct cpumask *cpumask;
 572
 573        cpumask = get_cpu_mask(cpu);
 574
 575        /*
 576         * Clear the boost-disable bit on the CPU_DOWN path so that
 577         * this cpu cannot block the remaining ones from boosting. On
 578         * the CPU_UP path we simply keep the boost-disable flag in
 579         * sync with the current global state.
 580         */
 581
 582        switch (action) {
 583        case CPU_UP_PREPARE:
 584        case CPU_UP_PREPARE_FROZEN:
 585                boost_set_msrs(boost_enabled, cpumask);
 586                break;
 587
 588        case CPU_DOWN_PREPARE:
 589        case CPU_DOWN_PREPARE_FROZEN:
 590                boost_set_msrs(1, cpumask);
 591                break;
 592
 593        default:
 594                break;
 595        }
 596
 597        return NOTIFY_OK;
 598}
 599
 600
 601static struct notifier_block boost_nb = {
 602        .notifier_call          = boost_notify,
 603};
 604
 605/*
 606 * acpi_cpufreq_early_init - initialize ACPI P-States library
 607 *
 608 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 609 * in order to determine correct frequency and voltage pairings. We can
 610 * do _PDC and _PSD and find out the processor dependency for the
 611 * actual init that will happen later...
 612 */
 613static int __init acpi_cpufreq_early_init(void)
 614{
 615        unsigned int i;
 616        pr_debug("acpi_cpufreq_early_init\n");
 617
 618        acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 619        if (!acpi_perf_data) {
 620                pr_debug("Memory allocation error for acpi_perf_data.\n");
 621                return -ENOMEM;
 622        }
 623        for_each_possible_cpu(i) {
 624                if (!zalloc_cpumask_var_node(
 625                        &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 626                        GFP_KERNEL, cpu_to_node(i))) {
 627
 628                        /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 629                        free_acpi_perf_data();
 630                        return -ENOMEM;
 631                }
 632        }
 633
 634        /* Do initialization in ACPI core */
 635        acpi_processor_preregister_performance(acpi_perf_data);
 636        return 0;
 637}
 638
 639#ifdef CONFIG_SMP
 640/*
 641 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 642 * or do it in BIOS firmware and won't inform about it to OS. If not
 643 * detected, this has a side effect of making CPU run at a different speed
 644 * than OS intended it to run at. Detect it and handle it cleanly.
 645 */
 646static int bios_with_sw_any_bug;
 647
 648static int sw_any_bug_found(const struct dmi_system_id *d)
 649{
 650        bios_with_sw_any_bug = 1;
 651        return 0;
 652}
 653
 654static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 655        {
 656                .callback = sw_any_bug_found,
 657                .ident = "Supermicro Server X6DLP",
 658                .matches = {
 659                        DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 660                        DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 661                        DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 662                },
 663        },
 664        { }
 665};
 666
 667static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
 668{
 669        /* Intel Xeon Processor 7100 Series Specification Update
 670         * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
 671         * AL30: A Machine Check Exception (MCE) Occurring during an
 672         * Enhanced Intel SpeedStep Technology Ratio Change May Cause
 673         * Both Processor Cores to Lock Up. */
 674        if (c->x86_vendor == X86_VENDOR_INTEL) {
 675                if ((c->x86 == 15) &&
 676                    (c->x86_model == 6) &&
 677                    (c->x86_mask == 8)) {
 678                        printk(KERN_INFO "acpi-cpufreq: Intel(R) "
 679                            "Xeon(R) 7100 Errata AL30, processors may "
 680                            "lock up on frequency changes: disabling "
 681                            "acpi-cpufreq.\n");
 682                        return -ENODEV;
 683                    }
 684                }
 685        return 0;
 686}
 687#endif
 688
 689static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 690{
 691        unsigned int i;
 692        unsigned int valid_states = 0;
 693        unsigned int cpu = policy->cpu;
 694        struct acpi_cpufreq_data *data;
 695        unsigned int result = 0;
 696        struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 697        struct acpi_processor_performance *perf;
 698#ifdef CONFIG_SMP
 699        static int blacklisted;
 700#endif
 701
 702        pr_debug("acpi_cpufreq_cpu_init\n");
 703
 704#ifdef CONFIG_SMP
 705        if (blacklisted)
 706                return blacklisted;
 707        blacklisted = acpi_cpufreq_blacklist(c);
 708        if (blacklisted)
 709                return blacklisted;
 710#endif
 711
 712        data = kzalloc(sizeof(*data), GFP_KERNEL);
 713        if (!data)
 714                return -ENOMEM;
 715
 716        if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
 717                result = -ENOMEM;
 718                goto err_free;
 719        }
 720
 721        data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
 722        per_cpu(acfreq_data, cpu) = data;
 723
 724        if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 725                acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 726
 727        result = acpi_processor_register_performance(data->acpi_data, cpu);
 728        if (result)
 729                goto err_free_mask;
 730
 731        perf = data->acpi_data;
 732        policy->shared_type = perf->shared_type;
 733
 734        /*
 735         * Will let policy->cpus know about dependency only when software
 736         * coordination is required.
 737         */
 738        if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 739            policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 740                cpumask_copy(policy->cpus, perf->shared_cpu_map);
 741        }
 742        cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
 743
 744#ifdef CONFIG_SMP
 745        dmi_check_system(sw_any_bug_dmi_table);
 746        if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
 747                policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 748                cpumask_copy(policy->cpus, cpu_core_mask(cpu));
 749        }
 750
 751        if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
 752                cpumask_clear(policy->cpus);
 753                cpumask_set_cpu(cpu, policy->cpus);
 754                cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
 755                policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
 756                pr_info_once(PFX "overriding BIOS provided _PSD data\n");
 757        }
 758#endif
 759
 760        /* capability check */
 761        if (perf->state_count <= 1) {
 762                pr_debug("No P-States\n");
 763                result = -ENODEV;
 764                goto err_unreg;
 765        }
 766
 767        if (perf->control_register.space_id != perf->status_register.space_id) {
 768                result = -ENODEV;
 769                goto err_unreg;
 770        }
 771
 772        switch (perf->control_register.space_id) {
 773        case ACPI_ADR_SPACE_SYSTEM_IO:
 774                if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
 775                    boot_cpu_data.x86 == 0xf) {
 776                        pr_debug("AMD K8 systems must use native drivers.\n");
 777                        result = -ENODEV;
 778                        goto err_unreg;
 779                }
 780                pr_debug("SYSTEM IO addr space\n");
 781                data->cpu_feature = SYSTEM_IO_CAPABLE;
 782                break;
 783        case ACPI_ADR_SPACE_FIXED_HARDWARE:
 784                pr_debug("HARDWARE addr space\n");
 785                if (check_est_cpu(cpu)) {
 786                        data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 787                        break;
 788                }
 789                if (check_amd_hwpstate_cpu(cpu)) {
 790                        data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
 791                        break;
 792                }
 793                result = -ENODEV;
 794                goto err_unreg;
 795        default:
 796                pr_debug("Unknown addr space %d\n",
 797                        (u32) (perf->control_register.space_id));
 798                result = -ENODEV;
 799                goto err_unreg;
 800        }
 801
 802        data->freq_table = kmalloc(sizeof(*data->freq_table) *
 803                    (perf->state_count+1), GFP_KERNEL);
 804        if (!data->freq_table) {
 805                result = -ENOMEM;
 806                goto err_unreg;
 807        }
 808
 809        /* detect transition latency */
 810        policy->cpuinfo.transition_latency = 0;
 811        for (i = 0; i < perf->state_count; i++) {
 812                if ((perf->states[i].transition_latency * 1000) >
 813                    policy->cpuinfo.transition_latency)
 814                        policy->cpuinfo.transition_latency =
 815                            perf->states[i].transition_latency * 1000;
 816        }
 817
 818        /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
 819        if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
 820            policy->cpuinfo.transition_latency > 20 * 1000) {
 821                policy->cpuinfo.transition_latency = 20 * 1000;
 822                printk_once(KERN_INFO
 823                            "P-state transition latency capped at 20 uS\n");
 824        }
 825
 826        /* table init */
 827        for (i = 0; i < perf->state_count; i++) {
 828                if (i > 0 && perf->states[i].core_frequency >=
 829                    data->freq_table[valid_states-1].frequency / 1000)
 830                        continue;
 831
 832                data->freq_table[valid_states].driver_data = i;
 833                data->freq_table[valid_states].frequency =
 834                    perf->states[i].core_frequency * 1000;
 835                valid_states++;
 836        }
 837        data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 838        perf->state = 0;
 839
 840        result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 841        if (result)
 842                goto err_freqfree;
 843
 844        if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
 845                printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
 846
 847        switch (perf->control_register.space_id) {
 848        case ACPI_ADR_SPACE_SYSTEM_IO:
 849                /* Current speed is unknown and not detectable by IO port */
 850                policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 851                break;
 852        case ACPI_ADR_SPACE_FIXED_HARDWARE:
 853                acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 854                policy->cur = get_cur_freq_on_cpu(cpu);
 855                break;
 856        default:
 857                break;
 858        }
 859
 860        /* notify BIOS that we exist */
 861        acpi_processor_notify_smm(THIS_MODULE);
 862
 863        pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
 864        for (i = 0; i < perf->state_count; i++)
 865                pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 866                        (i == perf->state ? '*' : ' '), i,
 867                        (u32) perf->states[i].core_frequency,
 868                        (u32) perf->states[i].power,
 869                        (u32) perf->states[i].transition_latency);
 870
 871        cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 872
 873        /*
 874         * the first call to ->target() should result in us actually
 875         * writing something to the appropriate registers.
 876         */
 877        data->resume = 1;
 878
 879        return result;
 880
 881err_freqfree:
 882        kfree(data->freq_table);
 883err_unreg:
 884        acpi_processor_unregister_performance(perf, cpu);
 885err_free_mask:
 886        free_cpumask_var(data->freqdomain_cpus);
 887err_free:
 888        kfree(data);
 889        per_cpu(acfreq_data, cpu) = NULL;
 890
 891        return result;
 892}
 893
 894static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 895{
 896        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 897
 898        pr_debug("acpi_cpufreq_cpu_exit\n");
 899
 900        if (data) {
 901                cpufreq_frequency_table_put_attr(policy->cpu);
 902                per_cpu(acfreq_data, policy->cpu) = NULL;
 903                acpi_processor_unregister_performance(data->acpi_data,
 904                                                      policy->cpu);
 905                free_cpumask_var(data->freqdomain_cpus);
 906                kfree(data->freq_table);
 907                kfree(data);
 908        }
 909
 910        return 0;
 911}
 912
 913static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 914{
 915        struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 916
 917        pr_debug("acpi_cpufreq_resume\n");
 918
 919        data->resume = 1;
 920
 921        return 0;
 922}
 923
 924static struct freq_attr *acpi_cpufreq_attr[] = {
 925        &cpufreq_freq_attr_scaling_available_freqs,
 926        &freqdomain_cpus,
 927        NULL,   /* this is a placeholder for cpb, do not remove */
 928        NULL,
 929};
 930
 931static struct cpufreq_driver acpi_cpufreq_driver = {
 932        .verify         = acpi_cpufreq_verify,
 933        .target         = acpi_cpufreq_target,
 934        .bios_limit     = acpi_processor_get_bios_limit,
 935        .init           = acpi_cpufreq_cpu_init,
 936        .exit           = acpi_cpufreq_cpu_exit,
 937        .resume         = acpi_cpufreq_resume,
 938        .name           = "acpi-cpufreq",
 939        .attr           = acpi_cpufreq_attr,
 940};
 941
 942static void __init acpi_cpufreq_boost_init(void)
 943{
 944        if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
 945                msrs = msrs_alloc();
 946
 947                if (!msrs)
 948                        return;
 949
 950                boost_supported = true;
 951                boost_enabled = boost_state(0);
 952
 953                get_online_cpus();
 954
 955                /* Force all MSRs to the same value */
 956                boost_set_msrs(boost_enabled, cpu_online_mask);
 957
 958                register_cpu_notifier(&boost_nb);
 959
 960                put_online_cpus();
 961        } else
 962                global_boost.attr.mode = 0444;
 963
 964        /* We create the boost file in any case, though for systems without
 965         * hardware support it will be read-only and hardwired to return 0.
 966         */
 967        if (cpufreq_sysfs_create_file(&(global_boost.attr)))
 968                pr_warn(PFX "could not register global boost sysfs file\n");
 969        else
 970                pr_debug("registered global boost sysfs file\n");
 971}
 972
 973static void __exit acpi_cpufreq_boost_exit(void)
 974{
 975        cpufreq_sysfs_remove_file(&(global_boost.attr));
 976
 977        if (msrs) {
 978                unregister_cpu_notifier(&boost_nb);
 979
 980                msrs_free(msrs);
 981                msrs = NULL;
 982        }
 983}
 984
 985static int __init acpi_cpufreq_init(void)
 986{
 987        int ret;
 988
 989        if (acpi_disabled)
 990                return -ENODEV;
 991
 992        /* don't keep reloading if cpufreq_driver exists */
 993        if (cpufreq_get_current_driver())
 994                return -EEXIST;
 995
 996        pr_debug("acpi_cpufreq_init\n");
 997
 998        ret = acpi_cpufreq_early_init();
 999        if (ret)
1000                return ret;
1001
1002#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
1003        /* this is a sysfs file with a strange name and an even stranger
1004         * semantic - per CPU instantiation, but system global effect.
1005         * Lets enable it only on AMD CPUs for compatibility reasons and
1006         * only if configured. This is considered legacy code, which
1007         * will probably be removed at some point in the future.
1008         */
1009        if (check_amd_hwpstate_cpu(0)) {
1010                struct freq_attr **iter;
1011
1012                pr_debug("adding sysfs entry for cpb\n");
1013
1014                for (iter = acpi_cpufreq_attr; *iter != NULL; iter++)
1015                        ;
1016
1017                /* make sure there is a terminator behind it */
1018                if (iter[1] == NULL)
1019                        *iter = &cpb;
1020        }
1021#endif
1022
1023        ret = cpufreq_register_driver(&acpi_cpufreq_driver);
1024        if (ret)
1025                free_acpi_perf_data();
1026        else
1027                acpi_cpufreq_boost_init();
1028
1029        return ret;
1030}
1031
1032static void __exit acpi_cpufreq_exit(void)
1033{
1034        pr_debug("acpi_cpufreq_exit\n");
1035
1036        acpi_cpufreq_boost_exit();
1037
1038        cpufreq_unregister_driver(&acpi_cpufreq_driver);
1039
1040        free_acpi_perf_data();
1041}
1042
1043module_param(acpi_pstate_strict, uint, 0644);
1044MODULE_PARM_DESC(acpi_pstate_strict,
1045        "value 0 or non-zero. non-zero -> strict ACPI checks are "
1046        "performed during frequency changes.");
1047
1048late_initcall(acpi_cpufreq_init);
1049module_exit(acpi_cpufreq_exit);
1050
1051static const struct x86_cpu_id acpi_cpufreq_ids[] = {
1052        X86_FEATURE_MATCH(X86_FEATURE_ACPI),
1053        X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
1054        {}
1055};
1056MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
1057
1058static const struct acpi_device_id processor_device_ids[] = {
1059        {ACPI_PROCESSOR_OBJECT_HID, },
1060        {ACPI_PROCESSOR_DEVICE_HID, },
1061        {},
1062};
1063MODULE_DEVICE_TABLE(acpi, processor_device_ids);
1064
1065MODULE_ALIAS("acpi");
1066
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