arch/x86/kernel/cpu/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 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
  51                 "acpi-cpufreq", msg)
  52
  53 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  54 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  55 MODULE_LICENSE("GPL");
  56
  57 enum {
  58         UNDEFINED_CAPABLE = 0,
  59         SYSTEM_INTEL_MSR_CAPABLE,
  60         SYSTEM_IO_CAPABLE,
  61 };
  62
  63 #define INTEL_MSR_RANGE         (0xffff)
  64
  65 struct acpi_cpufreq_data {
  66         struct acpi_processor_performance *acpi_data;
  67         struct cpufreq_frequency_table *freq_table;
  68         unsigned int resume;
  69         unsigned int cpu_feature;
  70 };
  71
  72 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
  73
  74 /* acpi_perf_data is a pointer to percpu data. */
  75 static struct acpi_processor_performance __percpu *acpi_perf_data;
  76
  77 static struct cpufreq_driver acpi_cpufreq_driver;
  78
  79 static unsigned int acpi_pstate_strict;
  80
  81 static int check_est_cpu(unsigned int cpuid)
  82 {
  83         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  84
  85         return cpu_has(cpu, X86_FEATURE_EST);
  86 }
  87
  88 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  89 {
  90         struct acpi_processor_performance *perf;
  91         int i;
  92
  93         perf = data->acpi_data;
  94
  95         for (i = 0; i < perf->state_count; i++) {
  96                 if (value == perf->states[i].status)
  97                         return data->freq_table[i].frequency;
  98         }
  99         return 0;
 100 }
 101
 102 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 103 {
 104         int i;
 105         struct acpi_processor_performance *perf;
 106
 107         msr &= INTEL_MSR_RANGE;
 108         perf = data->acpi_data;
 109
 110         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 111                 if (msr == perf->states[data->freq_table[i].index].status)
 112                         return data->freq_table[i].frequency;
 113         }
 114         return data->freq_table[0].frequency;
 115 }
 116
 117 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 118 {
 119         switch (data->cpu_feature) {
 120         case SYSTEM_INTEL_MSR_CAPABLE:
 121                 return extract_msr(val, data);
 122         case SYSTEM_IO_CAPABLE:
 123                 return extract_io(val, data);
 124         default:
 125                 return 0;
 126         }
 127 }
 128
 129 struct msr_addr {
 130         u32 reg;
 131 };
 132
 133 struct io_addr {
 134         u16 port;
 135         u8 bit_width;
 136 };
 137
 138 struct drv_cmd {
 139         unsigned int type;
 140         const struct cpumask *mask;
 141         union {
 142                 struct msr_addr msr;
 143                 struct io_addr io;
 144         } addr;
 145         u32 val;
 146 };
 147
 148 /* Called via smp_call_function_single(), on the target CPU */
 149 static void do_drv_read(void *_cmd)
 150 {
 151         struct drv_cmd *cmd = _cmd;
 152         u32 h;
 153
 154         switch (cmd->type) {
 155         case SYSTEM_INTEL_MSR_CAPABLE:
 156                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 157                 break;
 158         case SYSTEM_IO_CAPABLE:
 159                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 160                                 &cmd->val,
 161                                 (u32)cmd->addr.io.bit_width);
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167
 168 /* Called via smp_call_function_many(), on the target CPUs */
 169 static void do_drv_write(void *_cmd)
 170 {
 171         struct drv_cmd *cmd = _cmd;
 172         u32 lo, hi;
 173
 174         switch (cmd->type) {
 175         case SYSTEM_INTEL_MSR_CAPABLE:
 176                 rdmsr(cmd->addr.msr.reg, lo, hi);
 177                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
 178                 wrmsr(cmd->addr.msr.reg, lo, hi);
 179                 break;
 180         case SYSTEM_IO_CAPABLE:
 181                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 182                                 cmd->val,
 183                                 (u32)cmd->addr.io.bit_width);
 184                 break;
 185         default:
 186                 break;
 187         }
 188 }
 189
 190 static void drv_read(struct drv_cmd *cmd)
 191 {
 192         int err;
 193         cmd->val = 0;
 194
 195         err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
 196         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
 197 }
 198
 199 static void drv_write(struct drv_cmd *cmd)
 200 {
 201         int this_cpu;
 202
 203         this_cpu = get_cpu();
 204         if (cpumask_test_cpu(this_cpu, cmd->mask))
 205                 do_drv_write(cmd);
 206         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
 207         put_cpu();
 208 }
 209
 210 static u32 get_cur_val(const struct cpumask *mask)
 211 {
 212         struct acpi_processor_performance *perf;
 213         struct drv_cmd cmd;
 214
 215         if (unlikely(cpumask_empty(mask)))
 216                 return 0;
 217
 218         switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
 219         case SYSTEM_INTEL_MSR_CAPABLE:
 220                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 221                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 222                 break;
 223         case SYSTEM_IO_CAPABLE:
 224                 cmd.type = SYSTEM_IO_CAPABLE;
 225                 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
 226                 cmd.addr.io.port = perf->control_register.address;
 227                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 228                 break;
 229         default:
 230                 return 0;
 231         }
 232
 233         cmd.mask = mask;
 234         drv_read(&cmd);
 235
 236         dprintk("get_cur_val = %u\n", cmd.val);
 237
 238         return cmd.val;
 239 }
 240
 241 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 242 {
 243         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
 244         unsigned int freq;
 245         unsigned int cached_freq;
 246
 247         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 248
 249         if (unlikely(data == NULL ||
 250                      data->acpi_data == NULL || data->freq_table == NULL)) {
 251                 return 0;
 252         }
 253
 254         cached_freq = data->freq_table[data->acpi_data->state].frequency;
 255         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
 256         if (freq != cached_freq) {
 257                 /*
 258                  * The dreaded BIOS frequency change behind our back.
 259                  * Force set the frequency on next target call.
 260                  */
 261                 data->resume = 1;
 262         }
 263
 264         dprintk("cur freq = %u\n", freq);
 265
 266         return freq;
 267 }
 268
 269 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
 270                                 struct acpi_cpufreq_data *data)
 271 {
 272         unsigned int cur_freq;
 273         unsigned int i;
 274
 275         for (i = 0; i < 100; i++) {
 276                 cur_freq = extract_freq(get_cur_val(mask), data);
 277                 if (cur_freq == freq)
 278                         return 1;
 279                 udelay(10);
 280         }
 281         return 0;
 282 }
 283
 284 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 285                                unsigned int target_freq, unsigned int relation)
 286 {
 287         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 288         struct acpi_processor_performance *perf;
 289         struct cpufreq_freqs freqs;
 290         struct drv_cmd cmd;
 291         unsigned int next_state = 0; /* Index into freq_table */
 292         unsigned int next_perf_state = 0; /* Index into perf table */
 293         unsigned int i;
 294         int result = 0;
 295
 296         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 297
 298         if (unlikely(data == NULL ||
 299              data->acpi_data == NULL || data->freq_table == NULL)) {
 300                 return -ENODEV;
 301         }
 302
 303         perf = data->acpi_data;
 304         result = cpufreq_frequency_table_target(policy,
 305                                                 data->freq_table,
 306                                                 target_freq,
 307                                                 relation, &next_state);
 308         if (unlikely(result)) {
 309                 result = -ENODEV;
 310                 goto out;
 311         }
 312
 313         next_perf_state = data->freq_table[next_state].index;
 314         if (perf->state == next_perf_state) {
 315                 if (unlikely(data->resume)) {
 316                         dprintk("Called after resume, resetting to P%d\n",
 317                                 next_perf_state);
 318                         data->resume = 0;
 319                 } else {
 320                         dprintk("Already at target state (P%d)\n",
 321                                 next_perf_state);
 322                         goto out;
 323                 }
 324         }
 325
 326         switch (data->cpu_feature) {
 327         case SYSTEM_INTEL_MSR_CAPABLE:
 328                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 329                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 330                 cmd.val = (u32) perf->states[next_perf_state].control;
 331                 break;
 332         case SYSTEM_IO_CAPABLE:
 333                 cmd.type = SYSTEM_IO_CAPABLE;
 334                 cmd.addr.io.port = perf->control_register.address;
 335                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 336                 cmd.val = (u32) perf->states[next_perf_state].control;
 337                 break;
 338         default:
 339                 result = -ENODEV;
 340                 goto out;
 341         }
 342
 343         /* cpufreq holds the hotplug lock, so we are safe from here on */
 344         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 345                 cmd.mask = policy->cpus;
 346         else
 347                 cmd.mask = cpumask_of(policy->cpu);
 348
 349         freqs.old = perf->states[perf->state].core_frequency * 1000;
 350         freqs.new = data->freq_table[next_state].frequency;
 351         for_each_cpu(i, policy->cpus) {
 352                 freqs.cpu = i;
 353                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 354         }
 355
 356         drv_write(&cmd);
 357
 358         if (acpi_pstate_strict) {
 359                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 360                         dprintk("acpi_cpufreq_target failed (%d)\n",
 361                                 policy->cpu);
 362                         result = -EAGAIN;
 363                         goto out;
 364                 }
 365         }
 366
 367         for_each_cpu(i, policy->cpus) {
 368                 freqs.cpu = i;
 369                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 370         }
 371         perf->state = next_perf_state;
 372
 373 out:
 374         return result;
 375 }
 376
 377 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 378 {
 379         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 380
 381         dprintk("acpi_cpufreq_verify\n");
 382
 383         return cpufreq_frequency_table_verify(policy, data->freq_table);
 384 }
 385
 386 static unsigned long
 387 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 388 {
 389         struct acpi_processor_performance *perf = data->acpi_data;
 390
 391         if (cpu_khz) {
 392                 /* search the closest match to cpu_khz */
 393                 unsigned int i;
 394                 unsigned long freq;
 395                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 396
 397                 for (i = 0; i < (perf->state_count-1); i++) {
 398                         freq = freqn;
 399                         freqn = perf->states[i+1].core_frequency * 1000;
 400                         if ((2 * cpu_khz) > (freqn + freq)) {
 401                                 perf->state = i;
 402                                 return freq;
 403                         }
 404                 }
 405                 perf->state = perf->state_count-1;
 406                 return freqn;
 407         } else {
 408                 /* assume CPU is at P0... */
 409                 perf->state = 0;
 410                 return perf->states[0].core_frequency * 1000;
 411         }
 412 }
 413
 414 static void free_acpi_perf_data(void)
 415 {
 416         unsigned int i;
 417
 418         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 419         for_each_possible_cpu(i)
 420                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 421                                  ->shared_cpu_map);
 422         free_percpu(acpi_perf_data);
 423 }
 424
 425 /*
 426  * acpi_cpufreq_early_init - initialize ACPI P-States library
 427  *
 428  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 429  * in order to determine correct frequency and voltage pairings. We can
 430  * do _PDC and _PSD and find out the processor dependency for the
 431  * actual init that will happen later...
 432  */
 433 static int __init acpi_cpufreq_early_init(void)
 434 {
 435         unsigned int i;
 436         dprintk("acpi_cpufreq_early_init\n");
 437
 438         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 439         if (!acpi_perf_data) {
 440                 dprintk("Memory allocation error for acpi_perf_data.\n");
 441                 return -ENOMEM;
 442         }
 443         for_each_possible_cpu(i) {
 444                 if (!zalloc_cpumask_var_node(
 445                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 446                         GFP_KERNEL, cpu_to_node(i))) {
 447
 448                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 449                         free_acpi_perf_data();
 450                         return -ENOMEM;
 451                 }
 452         }
 453
 454         /* Do initialization in ACPI core */
 455         acpi_processor_preregister_performance(acpi_perf_data);
 456         return 0;
 457 }
 458
 459 #ifdef CONFIG_SMP
 460 /*
 461  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 462  * or do it in BIOS firmware and won't inform about it to OS. If not
 463  * detected, this has a side effect of making CPU run at a different speed
 464  * than OS intended it to run at. Detect it and handle it cleanly.
 465  */
 466 static int bios_with_sw_any_bug;
 467
 468 static int sw_any_bug_found(const struct dmi_system_id *d)
 469 {
 470         bios_with_sw_any_bug = 1;
 471         return 0;
 472 }
 473
 474 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 475         {
 476                 .callback = sw_any_bug_found,
 477                 .ident = "Supermicro Server X6DLP",
 478                 .matches = {
 479                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 480                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 481                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 482                 },
 483         },
 484         { }
 485 };
 486
 487 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
 488 {
 489         /* Intel Xeon Processor 7100 Series Specification Update
 490          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
 491          * AL30: A Machine Check Exception (MCE) Occurring during an
 492          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
 493          * Both Processor Cores to Lock Up. */
 494         if (c->x86_vendor == X86_VENDOR_INTEL) {
 495                 if ((c->x86 == 15) &&
 496                     (c->x86_model == 6) &&
 497                     (c->x86_mask == 8)) {
 498                         printk(KERN_INFO "acpi-cpufreq: Intel(R) "
 499                             "Xeon(R) 7100 Errata AL30, processors may "
 500                             "lock up on frequency changes: disabling "
 501                             "acpi-cpufreq.\n");
 502                         return -ENODEV;
 503                     }
 504                 }
 505         return 0;
 506 }
 507 #endif
 508
 509 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 510 {
 511         unsigned int i;
 512         unsigned int valid_states = 0;
 513         unsigned int cpu = policy->cpu;
 514         struct acpi_cpufreq_data *data;
 515         unsigned int result = 0;
 516         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 517         struct acpi_processor_performance *perf;
 518 #ifdef CONFIG_SMP
 519         static int blacklisted;
 520 #endif
 521
 522         dprintk("acpi_cpufreq_cpu_init\n");
 523
 524 #ifdef CONFIG_SMP
 525         if (blacklisted)
 526                 return blacklisted;
 527         blacklisted = acpi_cpufreq_blacklist(c);
 528         if (blacklisted)
 529                 return blacklisted;
 530 #endif
 531
 532         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 533         if (!data)
 534                 return -ENOMEM;
 535
 536         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
 537         per_cpu(acfreq_data, cpu) = data;
 538
 539         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 540                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 541
 542         result = acpi_processor_register_performance(data->acpi_data, cpu);
 543         if (result)
 544                 goto err_free;
 545
 546         perf = data->acpi_data;
 547         policy->shared_type = perf->shared_type;
 548
 549         /*
 550          * Will let policy->cpus know about dependency only when software
 551          * coordination is required.
 552          */
 553         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 554             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 555                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
 556         }
 557         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
 558
 559 #ifdef CONFIG_SMP
 560         dmi_check_system(sw_any_bug_dmi_table);
 561         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
 562                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 563                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
 564         }
 565 #endif
 566
 567         /* capability check */
 568         if (perf->state_count <= 1) {
 569                 dprintk("No P-States\n");
 570                 result = -ENODEV;
 571                 goto err_unreg;
 572         }
 573
 574         if (perf->control_register.space_id != perf->status_register.space_id) {
 575                 result = -ENODEV;
 576                 goto err_unreg;
 577         }
 578
 579         switch (perf->control_register.space_id) {
 580         case ACPI_ADR_SPACE_SYSTEM_IO:
 581                 dprintk("SYSTEM IO addr space\n");
 582                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 583                 break;
 584         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 585                 dprintk("HARDWARE addr space\n");
 586                 if (!check_est_cpu(cpu)) {
 587                         result = -ENODEV;
 588                         goto err_unreg;
 589                 }
 590                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 591                 break;
 592         default:
 593                 dprintk("Unknown addr space %d\n",
 594                         (u32) (perf->control_register.space_id));
 595                 result = -ENODEV;
 596                 goto err_unreg;
 597         }
 598
 599         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 600                     (perf->state_count+1), GFP_KERNEL);
 601         if (!data->freq_table) {
 602                 result = -ENOMEM;
 603                 goto err_unreg;
 604         }
 605
 606         /* detect transition latency */
 607         policy->cpuinfo.transition_latency = 0;
 608         for (i = 0; i < perf->state_count; i++) {
 609                 if ((perf->states[i].transition_latency * 1000) >
 610                     policy->cpuinfo.transition_latency)
 611                         policy->cpuinfo.transition_latency =
 612                             perf->states[i].transition_latency * 1000;
 613         }
 614
 615         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
 616         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
 617             policy->cpuinfo.transition_latency > 20 * 1000) {
 618                 policy->cpuinfo.transition_latency = 20 * 1000;
 619                 printk_once(KERN_INFO
 620                             "P-state transition latency capped at 20 uS\n");
 621         }
 622
 623         /* table init */
 624         for (i = 0; i < perf->state_count; i++) {
 625                 if (i > 0 && perf->states[i].core_frequency >=
 626                     data->freq_table[valid_states-1].frequency / 1000)
 627                         continue;
 628
 629                 data->freq_table[valid_states].index = i;
 630                 data->freq_table[valid_states].frequency =
 631                     perf->states[i].core_frequency * 1000;
 632                 valid_states++;
 633         }
 634         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 635         perf->state = 0;
 636
 637         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 638         if (result)
 639                 goto err_freqfree;
 640
 641         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
 642                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
 643
 644         switch (perf->control_register.space_id) {
 645         case ACPI_ADR_SPACE_SYSTEM_IO:
 646                 /* Current speed is unknown and not detectable by IO port */
 647                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 648                 break;
 649         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 650                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 651                 policy->cur = get_cur_freq_on_cpu(cpu);
 652                 break;
 653         default:
 654                 break;
 655         }
 656
 657         /* notify BIOS that we exist */
 658         acpi_processor_notify_smm(THIS_MODULE);
 659
 660         /* Check for APERF/MPERF support in hardware */
 661         if (cpu_has(c, X86_FEATURE_APERFMPERF))
 662                 acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
 663
 664         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 665         for (i = 0; i < perf->state_count; i++)
 666                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 667                         (i == perf->state ? '*' : ' '), i,
 668                         (u32) perf->states[i].core_frequency,
 669                         (u32) perf->states[i].power,
 670                         (u32) perf->states[i].transition_latency);
 671
 672         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 673
 674         /*
 675          * the first call to ->target() should result in us actually
 676          * writing something to the appropriate registers.
 677          */
 678         data->resume = 1;
 679
 680         return result;
 681
 682 err_freqfree:
 683         kfree(data->freq_table);
 684 err_unreg:
 685         acpi_processor_unregister_performance(perf, cpu);
 686 err_free:
 687         kfree(data);
 688         per_cpu(acfreq_data, cpu) = NULL;
 689
 690         return result;
 691 }
 692
 693 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 694 {
 695         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 696
 697         dprintk("acpi_cpufreq_cpu_exit\n");
 698
 699         if (data) {
 700                 cpufreq_frequency_table_put_attr(policy->cpu);
 701                 per_cpu(acfreq_data, policy->cpu) = NULL;
 702                 acpi_processor_unregister_performance(data->acpi_data,
 703                                                       policy->cpu);
 704                 kfree(data->freq_table);
 705                 kfree(data);
 706         }
 707
 708         return 0;
 709 }
 710
 711 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 712 {
 713         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 714
 715         dprintk("acpi_cpufreq_resume\n");
 716
 717         data->resume = 1;
 718
 719         return 0;
 720 }
 721
 722 static struct freq_attr *acpi_cpufreq_attr[] = {
 723         &cpufreq_freq_attr_scaling_available_freqs,
 724         NULL,
 725 };
 726
 727 static struct cpufreq_driver acpi_cpufreq_driver = {
 728         .verify         = acpi_cpufreq_verify,
 729         .target         = acpi_cpufreq_target,
 730         .bios_limit     = acpi_processor_get_bios_limit,
 731         .init           = acpi_cpufreq_cpu_init,
 732         .exit           = acpi_cpufreq_cpu_exit,
 733         .resume         = acpi_cpufreq_resume,
 734         .name           = "acpi-cpufreq",
 735         .owner          = THIS_MODULE,
 736         .attr           = acpi_cpufreq_attr,
 737 };
 738
 739 static int __init acpi_cpufreq_init(void)
 740 {
 741         int ret;
 742
 743         if (acpi_disabled)
 744                 return 0;
 745
 746         dprintk("acpi_cpufreq_init\n");
 747
 748         ret = acpi_cpufreq_early_init();
 749         if (ret)
 750                 return ret;
 751
 752         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
 753         if (ret)
 754                 free_acpi_perf_data();
 755
 756         return ret;
 757 }
 758
 759 static void __exit acpi_cpufreq_exit(void)
 760 {
 761         dprintk("acpi_cpufreq_exit\n");
 762
 763         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 764
 765         free_percpu(acpi_perf_data);
 766 }
 767
 768 module_param(acpi_pstate_strict, uint, 0644);
 769 MODULE_PARM_DESC(acpi_pstate_strict,
 770         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 771         "performed during frequency changes.");
 772
 773 late_initcall(acpi_cpufreq_init);
 774 module_exit(acpi_cpufreq_exit);
 775
 776 MODULE_ALIAS("acpi");