drivers/cpufreq/acpi-cpufreq.c

   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 #include "mperf.h"
  49
  50 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  51 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  52 MODULE_LICENSE("GPL");
  53
  54 enum {
  55         UNDEFINED_CAPABLE = 0,
  56         SYSTEM_INTEL_MSR_CAPABLE,
  57         SYSTEM_IO_CAPABLE,
  58 };
  59
  60 #define INTEL_MSR_RANGE         (0xffff)
  61
  62 struct acpi_cpufreq_data {
  63         struct acpi_processor_performance *acpi_data;
  64         struct cpufreq_frequency_table *freq_table;
  65         unsigned int resume;
  66         unsigned int cpu_feature;
  67 };
  68
  69 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
  70
  71 /* acpi_perf_data is a pointer to percpu data. */
  72 static struct acpi_processor_performance __percpu *acpi_perf_data;
  73
  74 static struct cpufreq_driver acpi_cpufreq_driver;
  75
  76 static unsigned int acpi_pstate_strict;
  77
  78 static int check_est_cpu(unsigned int cpuid)
  79 {
  80         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  81
  82         return cpu_has(cpu, X86_FEATURE_EST);
  83 }
  84
  85 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  86 {
  87         struct acpi_processor_performance *perf;
  88         int i;
  89
  90         perf = data->acpi_data;
  91
  92         for (i = 0; i < perf->state_count; i++) {
  93                 if (value == perf->states[i].status)
  94                         return data->freq_table[i].frequency;
  95         }
  96         return 0;
  97 }
  98
  99 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 100 {
 101         int i;
 102         struct acpi_processor_performance *perf;
 103
 104         msr &= INTEL_MSR_RANGE;
 105         perf = data->acpi_data;
 106
 107         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 108                 if (msr == perf->states[data->freq_table[i].index].status)
 109                         return data->freq_table[i].frequency;
 110         }
 111         return data->freq_table[0].frequency;
 112 }
 113
 114 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 115 {
 116         switch (data->cpu_feature) {
 117         case SYSTEM_INTEL_MSR_CAPABLE:
 118                 return extract_msr(val, data);
 119         case SYSTEM_IO_CAPABLE:
 120                 return extract_io(val, data);
 121         default:
 122                 return 0;
 123         }
 124 }
 125
 126 struct msr_addr {
 127         u32 reg;
 128 };
 129
 130 struct io_addr {
 131         u16 port;
 132         u8 bit_width;
 133 };
 134
 135 struct drv_cmd {
 136         unsigned int type;
 137         const struct cpumask *mask;
 138         union {
 139                 struct msr_addr msr;
 140                 struct io_addr io;
 141         } addr;
 142         u32 val;
 143 };
 144
 145 /* Called via smp_call_function_single(), on the target CPU */
 146 static void do_drv_read(void *_cmd)
 147 {
 148         struct drv_cmd *cmd = _cmd;
 149         u32 h;
 150
 151         switch (cmd->type) {
 152         case SYSTEM_INTEL_MSR_CAPABLE:
 153                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 154                 break;
 155         case SYSTEM_IO_CAPABLE:
 156                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 157                                 &cmd->val,
 158                                 (u32)cmd->addr.io.bit_width);
 159                 break;
 160         default:
 161                 break;
 162         }
 163 }
 164
 165 /* Called via smp_call_function_many(), on the target CPUs */
 166 static void do_drv_write(void *_cmd)
 167 {
 168         struct drv_cmd *cmd = _cmd;
 169         u32 lo, hi;
 170
 171         switch (cmd->type) {
 172         case SYSTEM_INTEL_MSR_CAPABLE:
 173                 rdmsr(cmd->addr.msr.reg, lo, hi);
 174                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
 175                 wrmsr(cmd->addr.msr.reg, lo, hi);
 176                 break;
 177         case SYSTEM_IO_CAPABLE:
 178                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 179                                 cmd->val,
 180                                 (u32)cmd->addr.io.bit_width);
 181                 break;
 182         default:
 183                 break;
 184         }
 185 }
 186
 187 static void drv_read(struct drv_cmd *cmd)
 188 {
 189         int err;
 190         cmd->val = 0;
 191
 192         err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
 193         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
 194 }
 195
 196 static void drv_write(struct drv_cmd *cmd)
 197 {
 198         int this_cpu;
 199
 200         this_cpu = get_cpu();
 201         if (cpumask_test_cpu(this_cpu, cmd->mask))
 202                 do_drv_write(cmd);
 203         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
 204         put_cpu();
 205 }
 206
 207 static u32 get_cur_val(const struct cpumask *mask)
 208 {
 209         struct acpi_processor_performance *perf;
 210         struct drv_cmd cmd;
 211
 212         if (unlikely(cpumask_empty(mask)))
 213                 return 0;
 214
 215         switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
 216         case SYSTEM_INTEL_MSR_CAPABLE:
 217                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 218                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 219                 break;
 220         case SYSTEM_IO_CAPABLE:
 221                 cmd.type = SYSTEM_IO_CAPABLE;
 222                 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
 223                 cmd.addr.io.port = perf->control_register.address;
 224                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 225                 break;
 226         default:
 227                 return 0;
 228         }
 229
 230         cmd.mask = mask;
 231         drv_read(&cmd);
 232
 233         pr_debug("get_cur_val = %u\n", cmd.val);
 234
 235         return cmd.val;
 236 }
 237
 238 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 239 {
 240         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
 241         unsigned int freq;
 242         unsigned int cached_freq;
 243
 244         pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
 245
 246         if (unlikely(data == NULL ||
 247                      data->acpi_data == NULL || data->freq_table == NULL)) {
 248                 return 0;
 249         }
 250
 251         cached_freq = data->freq_table[data->acpi_data->state].frequency;
 252         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
 253         if (freq != cached_freq) {
 254                 /*
 255                  * The dreaded BIOS frequency change behind our back.
 256                  * Force set the frequency on next target call.
 257                  */
 258                 data->resume = 1;
 259         }
 260
 261         pr_debug("cur freq = %u\n", freq);
 262
 263         return freq;
 264 }
 265
 266 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
 267                                 struct acpi_cpufreq_data *data)
 268 {
 269         unsigned int cur_freq;
 270         unsigned int i;
 271
 272         for (i = 0; i < 100; i++) {
 273                 cur_freq = extract_freq(get_cur_val(mask), data);
 274                 if (cur_freq == freq)
 275                         return 1;
 276                 udelay(10);
 277         }
 278         return 0;
 279 }
 280
 281 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 282                                unsigned int target_freq, unsigned int relation)
 283 {
 284         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 285         struct acpi_processor_performance *perf;
 286         struct cpufreq_freqs freqs;
 287         struct drv_cmd cmd;
 288         unsigned int next_state = 0; /* Index into freq_table */
 289         unsigned int next_perf_state = 0; /* Index into perf table */
 290         unsigned int i;
 291         int result = 0;
 292
 293         pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 294
 295         if (unlikely(data == NULL ||
 296              data->acpi_data == NULL || data->freq_table == NULL)) {
 297                 return -ENODEV;
 298         }
 299
 300         perf = data->acpi_data;
 301         result = cpufreq_frequency_table_target(policy,
 302                                                 data->freq_table,
 303                                                 target_freq,
 304                                                 relation, &next_state);
 305         if (unlikely(result)) {
 306                 result = -ENODEV;
 307                 goto out;
 308         }
 309
 310         next_perf_state = data->freq_table[next_state].index;
 311         if (perf->state == next_perf_state) {
 312                 if (unlikely(data->resume)) {
 313                         pr_debug("Called after resume, resetting to P%d\n",
 314                                 next_perf_state);
 315                         data->resume = 0;
 316                 } else {
 317                         pr_debug("Already at target state (P%d)\n",
 318                                 next_perf_state);
 319                         goto out;
 320                 }
 321         }
 322
 323         switch (data->cpu_feature) {
 324         case SYSTEM_INTEL_MSR_CAPABLE:
 325                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 326                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 327                 cmd.val = (u32) perf->states[next_perf_state].control;
 328                 break;
 329         case SYSTEM_IO_CAPABLE:
 330                 cmd.type = SYSTEM_IO_CAPABLE;
 331                 cmd.addr.io.port = perf->control_register.address;
 332                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 333                 cmd.val = (u32) perf->states[next_perf_state].control;
 334                 break;
 335         default:
 336                 result = -ENODEV;
 337                 goto out;
 338         }
 339
 340         /* cpufreq holds the hotplug lock, so we are safe from here on */
 341         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 342                 cmd.mask = policy->cpus;
 343         else
 344                 cmd.mask = cpumask_of(policy->cpu);
 345
 346         freqs.old = perf->states[perf->state].core_frequency * 1000;
 347         freqs.new = data->freq_table[next_state].frequency;
 348         for_each_cpu(i, policy->cpus) {
 349                 freqs.cpu = i;
 350                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 351         }
 352
 353         drv_write(&cmd);
 354
 355         if (acpi_pstate_strict) {
 356                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 357                         pr_debug("acpi_cpufreq_target failed (%d)\n",
 358                                 policy->cpu);
 359                         result = -EAGAIN;
 360                         goto out;
 361                 }
 362         }
 363
 364         for_each_cpu(i, policy->cpus) {
 365                 freqs.cpu = i;
 366                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 367         }
 368         perf->state = next_perf_state;
 369
 370 out:
 371         return result;
 372 }
 373
 374 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 375 {
 376         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 377
 378         pr_debug("acpi_cpufreq_verify\n");
 379
 380         return cpufreq_frequency_table_verify(policy, data->freq_table);
 381 }
 382
 383 static unsigned long
 384 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 385 {
 386         struct acpi_processor_performance *perf = data->acpi_data;
 387
 388         if (cpu_khz) {
 389                 /* search the closest match to cpu_khz */
 390                 unsigned int i;
 391                 unsigned long freq;
 392                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 393
 394                 for (i = 0; i < (perf->state_count-1); i++) {
 395                         freq = freqn;
 396                         freqn = perf->states[i+1].core_frequency * 1000;
 397                         if ((2 * cpu_khz) > (freqn + freq)) {
 398                                 perf->state = i;
 399                                 return freq;
 400                         }
 401                 }
 402                 perf->state = perf->state_count-1;
 403                 return freqn;
 404         } else {
 405                 /* assume CPU is at P0... */
 406                 perf->state = 0;
 407                 return perf->states[0].core_frequency * 1000;
 408         }
 409 }
 410
 411 static void free_acpi_perf_data(void)
 412 {
 413         unsigned int i;
 414
 415         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 416         for_each_possible_cpu(i)
 417                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 418                                  ->shared_cpu_map);
 419         free_percpu(acpi_perf_data);
 420 }
 421
 422 /*
 423  * acpi_cpufreq_early_init - initialize ACPI P-States library
 424  *
 425  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 426  * in order to determine correct frequency and voltage pairings. We can
 427  * do _PDC and _PSD and find out the processor dependency for the
 428  * actual init that will happen later...
 429  */
 430 static int __init acpi_cpufreq_early_init(void)
 431 {
 432         unsigned int i;
 433         pr_debug("acpi_cpufreq_early_init\n");
 434
 435         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 436         if (!acpi_perf_data) {
 437                 pr_debug("Memory allocation error for acpi_perf_data.\n");
 438                 return -ENOMEM;
 439         }
 440         for_each_possible_cpu(i) {
 441                 if (!zalloc_cpumask_var_node(
 442                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 443                         GFP_KERNEL, cpu_to_node(i))) {
 444
 445                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 446                         free_acpi_perf_data();
 447                         return -ENOMEM;
 448                 }
 449         }
 450
 451         /* Do initialization in ACPI core */
 452         acpi_processor_preregister_performance(acpi_perf_data);
 453         return 0;
 454 }
 455
 456 #ifdef CONFIG_SMP
 457 /*
 458  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 459  * or do it in BIOS firmware and won't inform about it to OS. If not
 460  * detected, this has a side effect of making CPU run at a different speed
 461  * than OS intended it to run at. Detect it and handle it cleanly.
 462  */
 463 static int bios_with_sw_any_bug;
 464
 465 static int sw_any_bug_found(const struct dmi_system_id *d)
 466 {
 467         bios_with_sw_any_bug = 1;
 468         return 0;
 469 }
 470
 471 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 472         {
 473                 .callback = sw_any_bug_found,
 474                 .ident = "Supermicro Server X6DLP",
 475                 .matches = {
 476                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 477                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 478                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 479                 },
 480         },
 481         { }
 482 };
 483
 484 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
 485 {
 486         /* Intel Xeon Processor 7100 Series Specification Update
 487          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
 488          * AL30: A Machine Check Exception (MCE) Occurring during an
 489          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
 490          * Both Processor Cores to Lock Up. */
 491         if (c->x86_vendor == X86_VENDOR_INTEL) {
 492                 if ((c->x86 == 15) &&
 493                     (c->x86_model == 6) &&
 494                     (c->x86_mask == 8)) {
 495                         printk(KERN_INFO "acpi-cpufreq: Intel(R) "
 496                             "Xeon(R) 7100 Errata AL30, processors may "
 497                             "lock up on frequency changes: disabling "
 498                             "acpi-cpufreq.\n");
 499                         return -ENODEV;
 500                     }
 501                 }
 502         return 0;
 503 }
 504 #endif
 505
 506 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 507 {
 508         unsigned int i;
 509         unsigned int valid_states = 0;
 510         unsigned int cpu = policy->cpu;
 511         struct acpi_cpufreq_data *data;
 512         unsigned int result = 0;
 513         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 514         struct acpi_processor_performance *perf;
 515 #ifdef CONFIG_SMP
 516         static int blacklisted;
 517 #endif
 518
 519         pr_debug("acpi_cpufreq_cpu_init\n");
 520
 521 #ifdef CONFIG_SMP
 522         if (blacklisted)
 523                 return blacklisted;
 524         blacklisted = acpi_cpufreq_blacklist(c);
 525         if (blacklisted)
 526                 return blacklisted;
 527 #endif
 528
 529         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 530         if (!data)
 531                 return -ENOMEM;
 532
 533         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
 534         per_cpu(acfreq_data, cpu) = data;
 535
 536         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 537                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 538
 539         result = acpi_processor_register_performance(data->acpi_data, cpu);
 540         if (result)
 541                 goto err_free;
 542
 543         perf = data->acpi_data;
 544         policy->shared_type = perf->shared_type;
 545
 546         /*
 547          * Will let policy->cpus know about dependency only when software
 548          * coordination is required.
 549          */
 550         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 551             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 552                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
 553         }
 554         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
 555
 556 #ifdef CONFIG_SMP
 557         dmi_check_system(sw_any_bug_dmi_table);
 558         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
 559                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 560                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
 561         }
 562 #endif
 563
 564         /* capability check */
 565         if (perf->state_count <= 1) {
 566                 pr_debug("No P-States\n");
 567                 result = -ENODEV;
 568                 goto err_unreg;
 569         }
 570
 571         if (perf->control_register.space_id != perf->status_register.space_id) {
 572                 result = -ENODEV;
 573                 goto err_unreg;
 574         }
 575
 576         switch (perf->control_register.space_id) {
 577         case ACPI_ADR_SPACE_SYSTEM_IO:
 578                 pr_debug("SYSTEM IO addr space\n");
 579                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 580                 break;
 581         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 582                 pr_debug("HARDWARE addr space\n");
 583                 if (!check_est_cpu(cpu)) {
 584                         result = -ENODEV;
 585                         goto err_unreg;
 586                 }
 587                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 588                 break;
 589         default:
 590                 pr_debug("Unknown addr space %d\n",
 591                         (u32) (perf->control_register.space_id));
 592                 result = -ENODEV;
 593                 goto err_unreg;
 594         }
 595
 596         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 597                     (perf->state_count+1), GFP_KERNEL);
 598         if (!data->freq_table) {
 599                 result = -ENOMEM;
 600                 goto err_unreg;
 601         }
 602
 603         /* detect transition latency */
 604         policy->cpuinfo.transition_latency = 0;
 605         for (i = 0; i < perf->state_count; i++) {
 606                 if ((perf->states[i].transition_latency * 1000) >
 607                     policy->cpuinfo.transition_latency)
 608                         policy->cpuinfo.transition_latency =
 609                             perf->states[i].transition_latency * 1000;
 610         }
 611
 612         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
 613         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
 614             policy->cpuinfo.transition_latency > 20 * 1000) {
 615                 policy->cpuinfo.transition_latency = 20 * 1000;
 616                 printk_once(KERN_INFO
 617                             "P-state transition latency capped at 20 uS\n");
 618         }
 619
 620         /* table init */
 621         for (i = 0; i < perf->state_count; i++) {
 622                 if (i > 0 && perf->states[i].core_frequency >=
 623                     data->freq_table[valid_states-1].frequency / 1000)
 624                         continue;
 625
 626                 data->freq_table[valid_states].index = i;
 627                 data->freq_table[valid_states].frequency =
 628                     perf->states[i].core_frequency * 1000;
 629                 valid_states++;
 630         }
 631         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 632         perf->state = 0;
 633
 634         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 635         if (result)
 636                 goto err_freqfree;
 637
 638         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
 639                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
 640
 641         switch (perf->control_register.space_id) {
 642         case ACPI_ADR_SPACE_SYSTEM_IO:
 643                 /* Current speed is unknown and not detectable by IO port */
 644                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 645                 break;
 646         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 647                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 648                 policy->cur = get_cur_freq_on_cpu(cpu);
 649                 break;
 650         default:
 651                 break;
 652         }
 653
 654         /* notify BIOS that we exist */
 655         acpi_processor_notify_smm(THIS_MODULE);
 656
 657         /* Check for APERF/MPERF support in hardware */
 658         if (cpu_has(c, X86_FEATURE_APERFMPERF))
 659                 acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
 660
 661         pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
 662         for (i = 0; i < perf->state_count; i++)
 663                 pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 664                         (i == perf->state ? '*' : ' '), i,
 665                         (u32) perf->states[i].core_frequency,
 666                         (u32) perf->states[i].power,
 667                         (u32) perf->states[i].transition_latency);
 668
 669         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 670
 671         /*
 672          * the first call to ->target() should result in us actually
 673          * writing something to the appropriate registers.
 674          */
 675         data->resume = 1;
 676
 677         return result;
 678
 679 err_freqfree:
 680         kfree(data->freq_table);
 681 err_unreg:
 682         acpi_processor_unregister_performance(perf, cpu);
 683 err_free:
 684         kfree(data);
 685         per_cpu(acfreq_data, cpu) = NULL;
 686
 687         return result;
 688 }
 689
 690 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 691 {
 692         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 693
 694         pr_debug("acpi_cpufreq_cpu_exit\n");
 695
 696         if (data) {
 697                 cpufreq_frequency_table_put_attr(policy->cpu);
 698                 per_cpu(acfreq_data, policy->cpu) = NULL;
 699                 acpi_processor_unregister_performance(data->acpi_data,
 700                                                       policy->cpu);
 701                 kfree(data->freq_table);
 702                 kfree(data);
 703         }
 704
 705         return 0;
 706 }
 707
 708 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 709 {
 710         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 711
 712         pr_debug("acpi_cpufreq_resume\n");
 713
 714         data->resume = 1;
 715
 716         return 0;
 717 }
 718
 719 static struct freq_attr *acpi_cpufreq_attr[] = {
 720         &cpufreq_freq_attr_scaling_available_freqs,
 721         NULL,
 722 };
 723
 724 static struct cpufreq_driver acpi_cpufreq_driver = {
 725         .verify         = acpi_cpufreq_verify,
 726         .target         = acpi_cpufreq_target,
 727         .bios_limit     = acpi_processor_get_bios_limit,
 728         .init           = acpi_cpufreq_cpu_init,
 729         .exit           = acpi_cpufreq_cpu_exit,
 730         .resume         = acpi_cpufreq_resume,
 731         .name           = "acpi-cpufreq",
 732         .owner          = THIS_MODULE,
 733         .attr           = acpi_cpufreq_attr,
 734 };
 735
 736 static int __init acpi_cpufreq_init(void)
 737 {
 738         int ret;
 739
 740         if (acpi_disabled)
 741                 return 0;
 742
 743         pr_debug("acpi_cpufreq_init\n");
 744
 745         ret = acpi_cpufreq_early_init();
 746         if (ret)
 747                 return ret;
 748
 749         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
 750         if (ret)
 751                 free_acpi_perf_data();
 752
 753         return ret;
 754 }
 755
 756 static void __exit acpi_cpufreq_exit(void)
 757 {
 758         pr_debug("acpi_cpufreq_exit\n");
 759
 760         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 761
 762         free_acpi_perf_data();
 763 }
 764
 765 module_param(acpi_pstate_strict, uint, 0644);
 766 MODULE_PARM_DESC(acpi_pstate_strict,
 767         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 768         "performed during frequency changes.");
 769
 770 late_initcall(acpi_cpufreq_init);
 771 module_exit(acpi_cpufreq_exit);
 772
 773 MODULE_ALIAS("acpi");