err.no Git - linux-2.6/blob - arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c

   1 /*
   2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
   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/sched.h>        /* current */
  36 #include <linux/dmi.h>
  37
  38 #include <linux/acpi.h>
  39 #include <acpi/processor.h>
  40
  41 #include <asm/io.h>
  42 #include <asm/msr.h>
  43 #include <asm/processor.h>
  44 #include <asm/cpufeature.h>
  45 #include <asm/delay.h>
  46 #include <asm/uaccess.h>
  47
  48 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
  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 struct acpi_cpufreq_data *drv_data[NR_CPUS];
  70 static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
  71
  72 static struct cpufreq_driver acpi_cpufreq_driver;
  73
  74 static unsigned int acpi_pstate_strict;
  75
  76 static int check_est_cpu(unsigned int cpuid)
  77 {
  78         struct cpuinfo_x86 *cpu = &cpu_data[cpuid];
  79
  80         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
  81             !cpu_has(cpu, X86_FEATURE_EST))
  82                 return 0;
  83
  84         return 1;
  85 }
  86
  87 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  88 {
  89         struct acpi_processor_performance *perf;
  90         int i;
  91
  92         perf = data->acpi_data;
  93
  94         for (i = 0; i < perf->state_count; i++) {
  95                 if (value == perf->states[i].status)
  96                         return data->freq_table[i].frequency;
  97         }
  98         return 0;
  99 }
 100
 101 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 102 {
 103         int i;
 104
 105         msr &= INTEL_MSR_RANGE;
 106         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 107                 if (msr == data->freq_table[i].index)
 108                         return data->freq_table[i].frequency;
 109         }
 110         return data->freq_table[0].frequency;
 111 }
 112
 113 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 114 {
 115         switch (data->cpu_feature) {
 116         case SYSTEM_INTEL_MSR_CAPABLE:
 117                 return extract_msr(val, data);
 118         case SYSTEM_IO_CAPABLE:
 119                 return extract_io(val, data);
 120         default:
 121                 return 0;
 122         }
 123 }
 124
 125 static void wrport(u16 port, u8 bit_width, u32 value)
 126 {
 127         if (bit_width <= 8) {
 128                 outb(value, port);
 129         } else if (bit_width <= 16) {
 130                 outw(value, port);
 131         } else if (bit_width <= 32) {
 132                 outl(value, port);
 133         }
 134 }
 135
 136 static void rdport(u16 port, u8 bit_width, u32 * ret)
 137 {
 138         *ret = 0;
 139         if (bit_width <= 8) {
 140                 *ret = inb(port);
 141         } else if (bit_width <= 16) {
 142                 *ret = inw(port);
 143         } else if (bit_width <= 32) {
 144                 *ret = inl(port);
 145         }
 146 }
 147
 148 struct msr_addr {
 149         u32 reg;
 150 };
 151
 152 struct io_addr {
 153         u16 port;
 154         u8 bit_width;
 155 };
 156
 157 typedef union {
 158         struct msr_addr msr;
 159         struct io_addr io;
 160 } drv_addr_union;
 161
 162 struct drv_cmd {
 163         unsigned int type;
 164         cpumask_t mask;
 165         drv_addr_union addr;
 166         u32 val;
 167 };
 168
 169 static void do_drv_read(struct drv_cmd *cmd)
 170 {
 171         u32 h;
 172
 173         switch (cmd->type) {
 174         case SYSTEM_INTEL_MSR_CAPABLE:
 175                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 176                 break;
 177         case SYSTEM_IO_CAPABLE:
 178                 rdport(cmd->addr.io.port, cmd->addr.io.bit_width, &cmd->val);
 179                 break;
 180         default:
 181                 break;
 182         }
 183 }
 184
 185 static void do_drv_write(struct drv_cmd *cmd)
 186 {
 187         u32 h = 0;
 188
 189         switch (cmd->type) {
 190         case SYSTEM_INTEL_MSR_CAPABLE:
 191                 wrmsr(cmd->addr.msr.reg, cmd->val, h);
 192                 break;
 193         case SYSTEM_IO_CAPABLE:
 194                 wrport(cmd->addr.io.port, cmd->addr.io.bit_width, cmd->val);
 195                 break;
 196         default:
 197                 break;
 198         }
 199 }
 200
 201 static inline void drv_read(struct drv_cmd *cmd)
 202 {
 203         cpumask_t saved_mask = current->cpus_allowed;
 204         cmd->val = 0;
 205
 206         set_cpus_allowed(current, cmd->mask);
 207         do_drv_read(cmd);
 208         set_cpus_allowed(current, saved_mask);
 209
 210 }
 211
 212 static void drv_write(struct drv_cmd *cmd)
 213 {
 214         cpumask_t saved_mask = current->cpus_allowed;
 215         unsigned int i;
 216
 217         for_each_cpu_mask(i, cmd->mask) {
 218                 set_cpus_allowed(current, cpumask_of_cpu(i));
 219                 do_drv_write(cmd);
 220         }
 221
 222         set_cpus_allowed(current, saved_mask);
 223         return;
 224 }
 225
 226 static u32 get_cur_val(cpumask_t mask)
 227 {
 228         struct acpi_processor_performance *perf;
 229         struct drv_cmd cmd;
 230
 231         if (unlikely(cpus_empty(mask)))
 232                 return 0;
 233
 234         switch (drv_data[first_cpu(mask)]->cpu_feature) {
 235         case SYSTEM_INTEL_MSR_CAPABLE:
 236                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 237                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 238                 break;
 239         case SYSTEM_IO_CAPABLE:
 240                 cmd.type = SYSTEM_IO_CAPABLE;
 241                 perf = drv_data[first_cpu(mask)]->acpi_data;
 242                 cmd.addr.io.port = perf->control_register.address;
 243                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 244                 break;
 245         default:
 246                 return 0;
 247         }
 248
 249         cmd.mask = mask;
 250
 251         drv_read(&cmd);
 252
 253         dprintk("get_cur_val = %u\n", cmd.val);
 254
 255         return cmd.val;
 256 }
 257
 258 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 259 {
 260         struct acpi_cpufreq_data *data = drv_data[cpu];
 261         unsigned int freq;
 262
 263         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 264
 265         if (unlikely(data == NULL ||
 266                      data->acpi_data == NULL || data->freq_table == NULL)) {
 267                 return 0;
 268         }
 269
 270         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
 271         dprintk("cur freq = %u\n", freq);
 272
 273         return freq;
 274 }
 275
 276 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
 277                                 struct acpi_cpufreq_data *data)
 278 {
 279         unsigned int cur_freq;
 280         unsigned int i;
 281
 282         for (i = 0; i < 100; i++) {
 283                 cur_freq = extract_freq(get_cur_val(mask), data);
 284                 if (cur_freq == freq)
 285                         return 1;
 286                 udelay(10);
 287         }
 288         return 0;
 289 }
 290
 291 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 292                                unsigned int target_freq, unsigned int relation)
 293 {
 294         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 295         struct acpi_processor_performance *perf;
 296         struct cpufreq_freqs freqs;
 297         cpumask_t online_policy_cpus;
 298         struct drv_cmd cmd;
 299         unsigned int msr;
 300         unsigned int next_state = 0;
 301         unsigned int next_perf_state = 0;
 302         unsigned int i;
 303         int result = 0;
 304
 305         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 306
 307         if (unlikely(data == NULL ||
 308                      data->acpi_data == NULL || data->freq_table == NULL)) {
 309                 return -ENODEV;
 310         }
 311
 312         perf = data->acpi_data;
 313         result = cpufreq_frequency_table_target(policy,
 314                                                 data->freq_table,
 315                                                 target_freq,
 316                                                 relation, &next_state);
 317         if (unlikely(result))
 318                 return -ENODEV;
 319
 320 #ifdef CONFIG_HOTPLUG_CPU
 321         /* cpufreq holds the hotplug lock, so we are safe from here on */
 322         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 323 #else
 324         online_policy_cpus = policy->cpus;
 325 #endif
 326
 327         next_perf_state = data->freq_table[next_state].index;
 328         if (perf->state == next_perf_state) {
 329                 if (unlikely(data->resume)) {
 330                         dprintk("Called after resume, resetting to P%d\n",
 331                                 next_perf_state);
 332                         data->resume = 0;
 333                 } else {
 334                         dprintk("Already at target state (P%d)\n",
 335                                 next_perf_state);
 336                         return 0;
 337                 }
 338         }
 339
 340         switch (data->cpu_feature) {
 341         case SYSTEM_INTEL_MSR_CAPABLE:
 342                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 343                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 344                 msr =
 345                     (u32) perf->states[next_perf_state].
 346                     control & INTEL_MSR_RANGE;
 347                 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 348                 break;
 349         case SYSTEM_IO_CAPABLE:
 350                 cmd.type = SYSTEM_IO_CAPABLE;
 351                 cmd.addr.io.port = perf->control_register.address;
 352                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 353                 cmd.val = (u32) perf->states[next_perf_state].control;
 354                 break;
 355         default:
 356                 return -ENODEV;
 357         }
 358
 359         cpus_clear(cmd.mask);
 360
 361         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 362                 cmd.mask = online_policy_cpus;
 363         else
 364                 cpu_set(policy->cpu, cmd.mask);
 365
 366         freqs.old = data->freq_table[perf->state].frequency;
 367         freqs.new = data->freq_table[next_perf_state].frequency;
 368         for_each_cpu_mask(i, cmd.mask) {
 369                 freqs.cpu = i;
 370                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 371         }
 372
 373         drv_write(&cmd);
 374
 375         if (acpi_pstate_strict) {
 376                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 377                         dprintk("acpi_cpufreq_target failed (%d)\n",
 378                                 policy->cpu);
 379                         return -EAGAIN;
 380                 }
 381         }
 382
 383         for_each_cpu_mask(i, cmd.mask) {
 384                 freqs.cpu = i;
 385                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 386         }
 387         perf->state = next_perf_state;
 388
 389         return result;
 390 }
 391
 392 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 393 {
 394         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 395
 396         dprintk("acpi_cpufreq_verify\n");
 397
 398         return cpufreq_frequency_table_verify(policy, data->freq_table);
 399 }
 400
 401 static unsigned long
 402 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 403 {
 404         struct acpi_processor_performance *perf = data->acpi_data;
 405
 406         if (cpu_khz) {
 407                 /* search the closest match to cpu_khz */
 408                 unsigned int i;
 409                 unsigned long freq;
 410                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 411
 412                 for (i = 0; i < (perf->state_count - 1); i++) {
 413                         freq = freqn;
 414                         freqn = perf->states[i + 1].core_frequency * 1000;
 415                         if ((2 * cpu_khz) > (freqn + freq)) {
 416                                 perf->state = i;
 417                                 return freq;
 418                         }
 419                 }
 420                 perf->state = perf->state_count - 1;
 421                 return freqn;
 422         } else {
 423                 /* assume CPU is at P0... */
 424                 perf->state = 0;
 425                 return perf->states[0].core_frequency * 1000;
 426         }
 427 }
 428
 429 /*
 430  * acpi_cpufreq_early_init - initialize ACPI P-States library
 431  *
 432  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 433  * in order to determine correct frequency and voltage pairings. We can
 434  * do _PDC and _PSD and find out the processor dependency for the
 435  * actual init that will happen later...
 436  */
 437 static int acpi_cpufreq_early_init(void)
 438 {
 439         struct acpi_processor_performance *data;
 440         cpumask_t covered;
 441         unsigned int i, j;
 442
 443         dprintk("acpi_cpufreq_early_init\n");
 444
 445         for_each_possible_cpu(i) {
 446                 data = kzalloc(sizeof(struct acpi_processor_performance),
 447                                GFP_KERNEL);
 448                 if (!data) {
 449                         for_each_cpu_mask(j, covered) {
 450                                 kfree(acpi_perf_data[j]);
 451                                 acpi_perf_data[j] = NULL;
 452                         }
 453                         return -ENOMEM;
 454                 }
 455                 acpi_perf_data[i] = data;
 456                 cpu_set(i, covered);
 457         }
 458
 459         /* Do initialization in ACPI core */
 460         acpi_processor_preregister_performance(acpi_perf_data);
 461         return 0;
 462 }
 463
 464 /*
 465  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 466  * or do it in BIOS firmware and won't inform about it to OS. If not
 467  * detected, this has a side effect of making CPU run at a different speed
 468  * than OS intended it to run at. Detect it and handle it cleanly.
 469  */
 470 static int bios_with_sw_any_bug;
 471
 472 static int sw_any_bug_found(struct dmi_system_id *d)
 473 {
 474         bios_with_sw_any_bug = 1;
 475         return 0;
 476 }
 477
 478 static struct dmi_system_id sw_any_bug_dmi_table[] = {
 479         {
 480                 .callback = sw_any_bug_found,
 481                 .ident = "Supermicro Server X6DLP",
 482                 .matches = {
 483                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 484                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 485                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 486                 },
 487         },
 488         { }
 489 };
 490
 491 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 492 {
 493         unsigned int i;
 494         unsigned int valid_states = 0;
 495         unsigned int cpu = policy->cpu;
 496         struct acpi_cpufreq_data *data;
 497         unsigned int l, h;
 498         unsigned int result = 0;
 499         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
 500         struct acpi_processor_performance *perf;
 501
 502         dprintk("acpi_cpufreq_cpu_init\n");
 503
 504         if (!acpi_perf_data[cpu])
 505                 return -ENODEV;
 506
 507         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 508         if (!data)
 509                 return -ENOMEM;
 510
 511         data->acpi_data = acpi_perf_data[cpu];
 512         drv_data[cpu] = data;
 513
 514         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
 515                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 516         }
 517
 518         result = acpi_processor_register_performance(data->acpi_data, cpu);
 519         if (result)
 520                 goto err_free;
 521
 522         perf = data->acpi_data;
 523         policy->shared_type = perf->shared_type;
 524         /*
 525          * Will let policy->cpus know about dependency only when software
 526          * coordination is required.
 527          */
 528         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 529             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 530                 policy->cpus = perf->shared_cpu_map;
 531         }
 532
 533 #ifdef CONFIG_SMP
 534         dmi_check_system(sw_any_bug_dmi_table);
 535         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 536                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 537                 policy->cpus = cpu_core_map[cpu];
 538         }
 539 #endif
 540
 541         /* capability check */
 542         if (perf->state_count <= 1) {
 543                 dprintk("No P-States\n");
 544                 result = -ENODEV;
 545                 goto err_unreg;
 546         }
 547
 548         if (perf->control_register.space_id != perf->status_register.space_id) {
 549                 result = -ENODEV;
 550                 goto err_unreg;
 551         }
 552
 553         switch (perf->control_register.space_id) {
 554         case ACPI_ADR_SPACE_SYSTEM_IO:
 555                 dprintk("SYSTEM IO addr space\n");
 556                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 557                 break;
 558         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 559                 dprintk("HARDWARE addr space\n");
 560                 if (!check_est_cpu(cpu)) {
 561                         result = -ENODEV;
 562                         goto err_unreg;
 563                 }
 564                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 565                 break;
 566         default:
 567                 dprintk("Unknown addr space %d\n",
 568                         (u32) (perf->control_register.space_id));
 569                 result = -ENODEV;
 570                 goto err_unreg;
 571         }
 572
 573         data->freq_table =
 574             kmalloc(sizeof(struct cpufreq_frequency_table) *
 575                     (perf->state_count + 1), GFP_KERNEL);
 576         if (!data->freq_table) {
 577                 result = -ENOMEM;
 578                 goto err_unreg;
 579         }
 580
 581         /* detect transition latency */
 582         policy->cpuinfo.transition_latency = 0;
 583         for (i = 0; i < perf->state_count; i++) {
 584                 if ((perf->states[i].transition_latency * 1000) >
 585                     policy->cpuinfo.transition_latency)
 586                         policy->cpuinfo.transition_latency =
 587                             perf->states[i].transition_latency * 1000;
 588         }
 589         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 590
 591         /* table init */
 592         for (i = 0; i < perf->state_count; i++) {
 593                 if (i > 0 && perf->states[i].core_frequency ==
 594                     perf->states[i - 1].core_frequency)
 595                         continue;
 596
 597                 data->freq_table[valid_states].index = i;
 598                 data->freq_table[valid_states].frequency =
 599                     perf->states[i].core_frequency * 1000;
 600                 valid_states++;
 601         }
 602         data->freq_table[perf->state_count].frequency = CPUFREQ_TABLE_END;
 603
 604         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 605         if (result) {
 606                 goto err_freqfree;
 607         }
 608
 609         switch (data->cpu_feature) {
 610         case ACPI_ADR_SPACE_SYSTEM_IO:
 611                 /* Current speed is unknown and not detectable by IO port */
 612                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 613                 break;
 614         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 615                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 616                 get_cur_freq_on_cpu(cpu);
 617                 break;
 618         default:
 619                 break;
 620         }
 621
 622         /* notify BIOS that we exist */
 623         acpi_processor_notify_smm(THIS_MODULE);
 624
 625         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 626         for (i = 0; i < perf->state_count; i++)
 627                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 628                         (i == perf->state ? '*' : ' '), i,
 629                         (u32) perf->states[i].core_frequency,
 630                         (u32) perf->states[i].power,
 631                         (u32) perf->states[i].transition_latency);
 632
 633         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 634
 635         /*
 636          * the first call to ->target() should result in us actually
 637          * writing something to the appropriate registers.
 638          */
 639         data->resume = 1;
 640
 641         return result;
 642
 643       err_freqfree:
 644         kfree(data->freq_table);
 645       err_unreg:
 646         acpi_processor_unregister_performance(perf, cpu);
 647       err_free:
 648         kfree(data);
 649         drv_data[cpu] = NULL;
 650
 651         return result;
 652 }
 653
 654 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 655 {
 656         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 657
 658         dprintk("acpi_cpufreq_cpu_exit\n");
 659
 660         if (data) {
 661                 cpufreq_frequency_table_put_attr(policy->cpu);
 662                 drv_data[policy->cpu] = NULL;
 663                 acpi_processor_unregister_performance(data->acpi_data,
 664                                                       policy->cpu);
 665                 kfree(data);
 666         }
 667
 668         return 0;
 669 }
 670
 671 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 672 {
 673         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 674
 675         dprintk("acpi_cpufreq_resume\n");
 676
 677         data->resume = 1;
 678
 679         return 0;
 680 }
 681
 682 static struct freq_attr *acpi_cpufreq_attr[] = {
 683         &cpufreq_freq_attr_scaling_available_freqs,
 684         NULL,
 685 };
 686
 687 static struct cpufreq_driver acpi_cpufreq_driver = {
 688         .verify = acpi_cpufreq_verify,
 689         .target = acpi_cpufreq_target,
 690         .init = acpi_cpufreq_cpu_init,
 691         .exit = acpi_cpufreq_cpu_exit,
 692         .resume = acpi_cpufreq_resume,
 693         .name = "acpi-cpufreq",
 694         .owner = THIS_MODULE,
 695         .attr = acpi_cpufreq_attr,
 696 };
 697
 698 static int __init acpi_cpufreq_init(void)
 699 {
 700         dprintk("acpi_cpufreq_init\n");
 701
 702         acpi_cpufreq_early_init();
 703
 704         return cpufreq_register_driver(&acpi_cpufreq_driver);
 705 }
 706
 707 static void __exit acpi_cpufreq_exit(void)
 708 {
 709         unsigned int i;
 710         dprintk("acpi_cpufreq_exit\n");
 711
 712         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 713
 714         for_each_possible_cpu(i) {
 715                 kfree(acpi_perf_data[i]);
 716                 acpi_perf_data[i] = NULL;
 717         }
 718         return;
 719 }
 720
 721 module_param(acpi_pstate_strict, uint, 0644);
 722 MODULE_PARM_DESC(acpi_pstate_strict,
 723                  "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
 724
 725 late_initcall(acpi_cpufreq_init);
 726 module_exit(acpi_cpufreq_exit);
 727
 728 MODULE_ALIAS("acpi");