arch/x86/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/dmi.h>
  36
  37 #include <linux/acpi.h>
  38 #include <acpi/processor.h>
  39
  40 #include <asm/io.h>
  41 #include <asm/msr.h>
  42 #include <asm/processor.h>
  43 #include <asm/cpufeature.h>
  44 #include <asm/delay.h>
  45 #include <asm/uaccess.h>
  46
  47 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
  48
  49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  51 MODULE_LICENSE("GPL");
  52
  53 enum {
  54         UNDEFINED_CAPABLE = 0,
  55         SYSTEM_INTEL_MSR_CAPABLE,
  56         SYSTEM_IO_CAPABLE,
  57 };
  58
  59 #define INTEL_MSR_RANGE         (0xffff)
  60 #define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
  61
  62 struct acpi_cpufreq_data {
  63         struct acpi_processor_performance *acpi_data;
  64         struct cpufreq_frequency_table *freq_table;
  65         unsigned int max_freq;
  66         unsigned int resume;
  67         unsigned int cpu_feature;
  68 };
  69
  70 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
  71
  72 /* acpi_perf_data is a pointer to percpu data. */
  73 static struct acpi_processor_performance *acpi_perf_data;
  74
  75 static struct cpufreq_driver acpi_cpufreq_driver;
  76
  77 static unsigned int acpi_pstate_strict;
  78
  79 static int check_est_cpu(unsigned int cpuid)
  80 {
  81         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  82
  83         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
  84             !cpu_has(cpu, X86_FEATURE_EST))
  85                 return 0;
  86
  87         return 1;
  88 }
  89
  90 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  91 {
  92         struct acpi_processor_performance *perf;
  93         int i;
  94
  95         perf = data->acpi_data;
  96
  97         for (i=0; i<perf->state_count; i++) {
  98                 if (value == perf->states[i].status)
  99                         return data->freq_table[i].frequency;
 100         }
 101         return 0;
 102 }
 103
 104 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 105 {
 106         int i;
 107         struct acpi_processor_performance *perf;
 108
 109         msr &= INTEL_MSR_RANGE;
 110         perf = data->acpi_data;
 111
 112         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 113                 if (msr == perf->states[data->freq_table[i].index].status)
 114                         return data->freq_table[i].frequency;
 115         }
 116         return data->freq_table[0].frequency;
 117 }
 118
 119 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 120 {
 121         switch (data->cpu_feature) {
 122         case SYSTEM_INTEL_MSR_CAPABLE:
 123                 return extract_msr(val, data);
 124         case SYSTEM_IO_CAPABLE:
 125                 return extract_io(val, data);
 126         default:
 127                 return 0;
 128         }
 129 }
 130
 131 struct msr_addr {
 132         u32 reg;
 133 };
 134
 135 struct io_addr {
 136         u16 port;
 137         u8 bit_width;
 138 };
 139
 140 typedef union {
 141         struct msr_addr msr;
 142         struct io_addr io;
 143 } drv_addr_union;
 144
 145 struct drv_cmd {
 146         unsigned int type;
 147         cpumask_t mask;
 148         drv_addr_union addr;
 149         u32 val;
 150 };
 151
 152 static void do_drv_read(struct drv_cmd *cmd)
 153 {
 154         u32 h;
 155
 156         switch (cmd->type) {
 157         case SYSTEM_INTEL_MSR_CAPABLE:
 158                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 159                 break;
 160         case SYSTEM_IO_CAPABLE:
 161                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 162                                 &cmd->val,
 163                                 (u32)cmd->addr.io.bit_width);
 164                 break;
 165         default:
 166                 break;
 167         }
 168 }
 169
 170 static void do_drv_write(struct drv_cmd *cmd)
 171 {
 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         cpumask_t saved_mask = current->cpus_allowed;
 193         cmd->val = 0;
 194
 195         set_cpus_allowed_ptr(current, &cmd->mask);
 196         do_drv_read(cmd);
 197         set_cpus_allowed_ptr(current, &saved_mask);
 198 }
 199
 200 static void drv_write(struct drv_cmd *cmd)
 201 {
 202         cpumask_t saved_mask = current->cpus_allowed;
 203         cpumask_of_cpu_ptr_declare(cpu_mask);
 204         unsigned int i;
 205
 206         for_each_cpu_mask_nr(i, cmd->mask) {
 207                 cpumask_of_cpu_ptr_next(cpu_mask, i);
 208                 set_cpus_allowed_ptr(current, cpu_mask);
 209                 do_drv_write(cmd);
 210         }
 211
 212         set_cpus_allowed_ptr(current, &saved_mask);
 213         return;
 214 }
 215
 216 static u32 get_cur_val(const cpumask_t *mask)
 217 {
 218         struct acpi_processor_performance *perf;
 219         struct drv_cmd cmd;
 220
 221         if (unlikely(cpus_empty(*mask)))
 222                 return 0;
 223
 224         switch (per_cpu(drv_data, first_cpu(*mask))->cpu_feature) {
 225         case SYSTEM_INTEL_MSR_CAPABLE:
 226                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 227                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 228                 break;
 229         case SYSTEM_IO_CAPABLE:
 230                 cmd.type = SYSTEM_IO_CAPABLE;
 231                 perf = per_cpu(drv_data, first_cpu(*mask))->acpi_data;
 232                 cmd.addr.io.port = perf->control_register.address;
 233                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 234                 break;
 235         default:
 236                 return 0;
 237         }
 238
 239         cmd.mask = *mask;
 240
 241         drv_read(&cmd);
 242
 243         dprintk("get_cur_val = %u\n", cmd.val);
 244
 245         return cmd.val;
 246 }
 247
 248 /*
 249  * Return the measured active (C0) frequency on this CPU since last call
 250  * to this function.
 251  * Input: cpu number
 252  * Return: Average CPU frequency in terms of max frequency (zero on error)
 253  *
 254  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 255  * over a period of time, while CPU is in C0 state.
 256  * IA32_MPERF counts at the rate of max advertised frequency
 257  * IA32_APERF counts at the rate of actual CPU frequency
 258  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 259  * no meaning should be associated with absolute values of these MSRs.
 260  */
 261 static unsigned int get_measured_perf(unsigned int cpu)
 262 {
 263         union {
 264                 struct {
 265                         u32 lo;
 266                         u32 hi;
 267                 } split;
 268                 u64 whole;
 269         } aperf_cur, mperf_cur;
 270
 271         cpumask_t saved_mask;
 272         cpumask_of_cpu_ptr(cpu_mask, cpu);
 273         unsigned int perf_percent;
 274         unsigned int retval;
 275
 276         saved_mask = current->cpus_allowed;
 277         set_cpus_allowed_ptr(current, cpu_mask);
 278         if (get_cpu() != cpu) {
 279                 /* We were not able to run on requested processor */
 280                 put_cpu();
 281                 return 0;
 282         }
 283
 284         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
 285         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
 286
 287         wrmsr(MSR_IA32_APERF, 0,0);
 288         wrmsr(MSR_IA32_MPERF, 0,0);
 289
 290 #ifdef __i386__
 291         /*
 292          * We dont want to do 64 bit divide with 32 bit kernel
 293          * Get an approximate value. Return failure in case we cannot get
 294          * an approximate value.
 295          */
 296         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
 297                 int shift_count;
 298                 u32 h;
 299
 300                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
 301                 shift_count = fls(h);
 302
 303                 aperf_cur.whole >>= shift_count;
 304                 mperf_cur.whole >>= shift_count;
 305         }
 306
 307         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
 308                 int shift_count = 7;
 309                 aperf_cur.split.lo >>= shift_count;
 310                 mperf_cur.split.lo >>= shift_count;
 311         }
 312
 313         if (aperf_cur.split.lo && mperf_cur.split.lo)
 314                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
 315         else
 316                 perf_percent = 0;
 317
 318 #else
 319         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
 320                 int shift_count = 7;
 321                 aperf_cur.whole >>= shift_count;
 322                 mperf_cur.whole >>= shift_count;
 323         }
 324
 325         if (aperf_cur.whole && mperf_cur.whole)
 326                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
 327         else
 328                 perf_percent = 0;
 329
 330 #endif
 331
 332         retval = per_cpu(drv_data, cpu)->max_freq * perf_percent / 100;
 333
 334         put_cpu();
 335         set_cpus_allowed_ptr(current, &saved_mask);
 336
 337         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
 338         return retval;
 339 }
 340
 341 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 342 {
 343         cpumask_of_cpu_ptr(cpu_mask, cpu);
 344         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
 345         unsigned int freq;
 346         unsigned int cached_freq;
 347
 348         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 349
 350         if (unlikely(data == NULL ||
 351                      data->acpi_data == NULL || data->freq_table == NULL)) {
 352                 return 0;
 353         }
 354
 355         cached_freq = data->freq_table[data->acpi_data->state].frequency;
 356         freq = extract_freq(get_cur_val(cpu_mask), data);
 357         if (freq != cached_freq) {
 358                 /*
 359                  * The dreaded BIOS frequency change behind our back.
 360                  * Force set the frequency on next target call.
 361                  */
 362                 data->resume = 1;
 363         }
 364
 365         dprintk("cur freq = %u\n", freq);
 366
 367         return freq;
 368 }
 369
 370 static unsigned int check_freqs(const cpumask_t *mask, unsigned int freq,
 371                                 struct acpi_cpufreq_data *data)
 372 {
 373         unsigned int cur_freq;
 374         unsigned int i;
 375
 376         for (i=0; i<100; i++) {
 377                 cur_freq = extract_freq(get_cur_val(mask), data);
 378                 if (cur_freq == freq)
 379                         return 1;
 380                 udelay(10);
 381         }
 382         return 0;
 383 }
 384
 385 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 386                                unsigned int target_freq, unsigned int relation)
 387 {
 388         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
 389         struct acpi_processor_performance *perf;
 390         struct cpufreq_freqs freqs;
 391         cpumask_t online_policy_cpus;
 392         struct drv_cmd cmd;
 393         unsigned int next_state = 0; /* Index into freq_table */
 394         unsigned int next_perf_state = 0; /* Index into perf table */
 395         unsigned int i;
 396         int result = 0;
 397
 398         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 399
 400         if (unlikely(data == NULL ||
 401              data->acpi_data == NULL || data->freq_table == NULL)) {
 402                 return -ENODEV;
 403         }
 404
 405         perf = data->acpi_data;
 406         result = cpufreq_frequency_table_target(policy,
 407                                                 data->freq_table,
 408                                                 target_freq,
 409                                                 relation, &next_state);
 410         if (unlikely(result))
 411                 return -ENODEV;
 412
 413 #ifdef CONFIG_HOTPLUG_CPU
 414         /* cpufreq holds the hotplug lock, so we are safe from here on */
 415         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 416 #else
 417         online_policy_cpus = policy->cpus;
 418 #endif
 419
 420         next_perf_state = data->freq_table[next_state].index;
 421         if (perf->state == next_perf_state) {
 422                 if (unlikely(data->resume)) {
 423                         dprintk("Called after resume, resetting to P%d\n",
 424                                 next_perf_state);
 425                         data->resume = 0;
 426                 } else {
 427                         dprintk("Already at target state (P%d)\n",
 428                                 next_perf_state);
 429                         return 0;
 430                 }
 431         }
 432
 433         switch (data->cpu_feature) {
 434         case SYSTEM_INTEL_MSR_CAPABLE:
 435                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 436                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 437                 cmd.val = (u32) perf->states[next_perf_state].control;
 438                 break;
 439         case SYSTEM_IO_CAPABLE:
 440                 cmd.type = SYSTEM_IO_CAPABLE;
 441                 cmd.addr.io.port = perf->control_register.address;
 442                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 443                 cmd.val = (u32) perf->states[next_perf_state].control;
 444                 break;
 445         default:
 446                 return -ENODEV;
 447         }
 448
 449         cpus_clear(cmd.mask);
 450
 451         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 452                 cmd.mask = online_policy_cpus;
 453         else
 454                 cpu_set(policy->cpu, cmd.mask);
 455
 456         freqs.old = perf->states[perf->state].core_frequency * 1000;
 457         freqs.new = data->freq_table[next_state].frequency;
 458         for_each_cpu_mask_nr(i, cmd.mask) {
 459                 freqs.cpu = i;
 460                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 461         }
 462
 463         drv_write(&cmd);
 464
 465         if (acpi_pstate_strict) {
 466                 if (!check_freqs(&cmd.mask, freqs.new, data)) {
 467                         dprintk("acpi_cpufreq_target failed (%d)\n",
 468                                 policy->cpu);
 469                         return -EAGAIN;
 470                 }
 471         }
 472
 473         for_each_cpu_mask_nr(i, cmd.mask) {
 474                 freqs.cpu = i;
 475                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 476         }
 477         perf->state = next_perf_state;
 478
 479         return result;
 480 }
 481
 482 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 483 {
 484         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
 485
 486         dprintk("acpi_cpufreq_verify\n");
 487
 488         return cpufreq_frequency_table_verify(policy, data->freq_table);
 489 }
 490
 491 static unsigned long
 492 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 493 {
 494         struct acpi_processor_performance *perf = data->acpi_data;
 495
 496         if (cpu_khz) {
 497                 /* search the closest match to cpu_khz */
 498                 unsigned int i;
 499                 unsigned long freq;
 500                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 501
 502                 for (i=0; i<(perf->state_count-1); i++) {
 503                         freq = freqn;
 504                         freqn = perf->states[i+1].core_frequency * 1000;
 505                         if ((2 * cpu_khz) > (freqn + freq)) {
 506                                 perf->state = i;
 507                                 return freq;
 508                         }
 509                 }
 510                 perf->state = perf->state_count-1;
 511                 return freqn;
 512         } else {
 513                 /* assume CPU is at P0... */
 514                 perf->state = 0;
 515                 return perf->states[0].core_frequency * 1000;
 516         }
 517 }
 518
 519 /*
 520  * acpi_cpufreq_early_init - initialize ACPI P-States library
 521  *
 522  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 523  * in order to determine correct frequency and voltage pairings. We can
 524  * do _PDC and _PSD and find out the processor dependency for the
 525  * actual init that will happen later...
 526  */
 527 static int __init acpi_cpufreq_early_init(void)
 528 {
 529         dprintk("acpi_cpufreq_early_init\n");
 530
 531         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 532         if (!acpi_perf_data) {
 533                 dprintk("Memory allocation error for acpi_perf_data.\n");
 534                 return -ENOMEM;
 535         }
 536
 537         /* Do initialization in ACPI core */
 538         acpi_processor_preregister_performance(acpi_perf_data);
 539         return 0;
 540 }
 541
 542 #ifdef CONFIG_SMP
 543 /*
 544  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 545  * or do it in BIOS firmware and won't inform about it to OS. If not
 546  * detected, this has a side effect of making CPU run at a different speed
 547  * than OS intended it to run at. Detect it and handle it cleanly.
 548  */
 549 static int bios_with_sw_any_bug;
 550
 551 static int sw_any_bug_found(const struct dmi_system_id *d)
 552 {
 553         bios_with_sw_any_bug = 1;
 554         return 0;
 555 }
 556
 557 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 558         {
 559                 .callback = sw_any_bug_found,
 560                 .ident = "Supermicro Server X6DLP",
 561                 .matches = {
 562                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 563                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 564                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 565                 },
 566         },
 567         { }
 568 };
 569 #endif
 570
 571 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 572 {
 573         unsigned int i;
 574         unsigned int valid_states = 0;
 575         unsigned int cpu = policy->cpu;
 576         struct acpi_cpufreq_data *data;
 577         unsigned int result = 0;
 578         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 579         struct acpi_processor_performance *perf;
 580
 581         dprintk("acpi_cpufreq_cpu_init\n");
 582
 583         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 584         if (!data)
 585                 return -ENOMEM;
 586
 587         data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
 588         per_cpu(drv_data, cpu) = data;
 589
 590         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 591                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 592
 593         result = acpi_processor_register_performance(data->acpi_data, cpu);
 594         if (result)
 595                 goto err_free;
 596
 597         perf = data->acpi_data;
 598         policy->shared_type = perf->shared_type;
 599
 600         /*
 601          * Will let policy->cpus know about dependency only when software
 602          * coordination is required.
 603          */
 604         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 605             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 606                 policy->cpus = perf->shared_cpu_map;
 607         }
 608         policy->related_cpus = perf->shared_cpu_map;
 609
 610 #ifdef CONFIG_SMP
 611         dmi_check_system(sw_any_bug_dmi_table);
 612         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 613                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 614                 policy->cpus = per_cpu(cpu_core_map, cpu);
 615         }
 616 #endif
 617
 618         /* capability check */
 619         if (perf->state_count <= 1) {
 620                 dprintk("No P-States\n");
 621                 result = -ENODEV;
 622                 goto err_unreg;
 623         }
 624
 625         if (perf->control_register.space_id != perf->status_register.space_id) {
 626                 result = -ENODEV;
 627                 goto err_unreg;
 628         }
 629
 630         switch (perf->control_register.space_id) {
 631         case ACPI_ADR_SPACE_SYSTEM_IO:
 632                 dprintk("SYSTEM IO addr space\n");
 633                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 634                 break;
 635         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 636                 dprintk("HARDWARE addr space\n");
 637                 if (!check_est_cpu(cpu)) {
 638                         result = -ENODEV;
 639                         goto err_unreg;
 640                 }
 641                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 642                 break;
 643         default:
 644                 dprintk("Unknown addr space %d\n",
 645                         (u32) (perf->control_register.space_id));
 646                 result = -ENODEV;
 647                 goto err_unreg;
 648         }
 649
 650         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 651                     (perf->state_count+1), GFP_KERNEL);
 652         if (!data->freq_table) {
 653                 result = -ENOMEM;
 654                 goto err_unreg;
 655         }
 656
 657         /* detect transition latency */
 658         policy->cpuinfo.transition_latency = 0;
 659         for (i=0; i<perf->state_count; i++) {
 660                 if ((perf->states[i].transition_latency * 1000) >
 661                     policy->cpuinfo.transition_latency)
 662                         policy->cpuinfo.transition_latency =
 663                             perf->states[i].transition_latency * 1000;
 664         }
 665
 666         data->max_freq = perf->states[0].core_frequency * 1000;
 667         /* table init */
 668         for (i=0; i<perf->state_count; i++) {
 669                 if (i>0 && perf->states[i].core_frequency >=
 670                     data->freq_table[valid_states-1].frequency / 1000)
 671                         continue;
 672
 673                 data->freq_table[valid_states].index = i;
 674                 data->freq_table[valid_states].frequency =
 675                     perf->states[i].core_frequency * 1000;
 676                 valid_states++;
 677         }
 678         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 679         perf->state = 0;
 680
 681         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 682         if (result)
 683                 goto err_freqfree;
 684
 685         switch (perf->control_register.space_id) {
 686         case ACPI_ADR_SPACE_SYSTEM_IO:
 687                 /* Current speed is unknown and not detectable by IO port */
 688                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 689                 break;
 690         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 691                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 692                 policy->cur = get_cur_freq_on_cpu(cpu);
 693                 break;
 694         default:
 695                 break;
 696         }
 697
 698         /* notify BIOS that we exist */
 699         acpi_processor_notify_smm(THIS_MODULE);
 700
 701         /* Check for APERF/MPERF support in hardware */
 702         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
 703                 unsigned int ecx;
 704                 ecx = cpuid_ecx(6);
 705                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
 706                         acpi_cpufreq_driver.getavg = get_measured_perf;
 707         }
 708
 709         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 710         for (i = 0; i < perf->state_count; i++)
 711                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 712                         (i == perf->state ? '*' : ' '), i,
 713                         (u32) perf->states[i].core_frequency,
 714                         (u32) perf->states[i].power,
 715                         (u32) perf->states[i].transition_latency);
 716
 717         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 718
 719         /*
 720          * the first call to ->target() should result in us actually
 721          * writing something to the appropriate registers.
 722          */
 723         data->resume = 1;
 724
 725         return result;
 726
 727 err_freqfree:
 728         kfree(data->freq_table);
 729 err_unreg:
 730         acpi_processor_unregister_performance(perf, cpu);
 731 err_free:
 732         kfree(data);
 733         per_cpu(drv_data, cpu) = NULL;
 734
 735         return result;
 736 }
 737
 738 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 739 {
 740         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
 741
 742         dprintk("acpi_cpufreq_cpu_exit\n");
 743
 744         if (data) {
 745                 cpufreq_frequency_table_put_attr(policy->cpu);
 746                 per_cpu(drv_data, policy->cpu) = NULL;
 747                 acpi_processor_unregister_performance(data->acpi_data,
 748                                                       policy->cpu);
 749                 kfree(data);
 750         }
 751
 752         return 0;
 753 }
 754
 755 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 756 {
 757         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
 758
 759         dprintk("acpi_cpufreq_resume\n");
 760
 761         data->resume = 1;
 762
 763         return 0;
 764 }
 765
 766 static struct freq_attr *acpi_cpufreq_attr[] = {
 767         &cpufreq_freq_attr_scaling_available_freqs,
 768         NULL,
 769 };
 770
 771 static struct cpufreq_driver acpi_cpufreq_driver = {
 772         .verify = acpi_cpufreq_verify,
 773         .target = acpi_cpufreq_target,
 774         .init = acpi_cpufreq_cpu_init,
 775         .exit = acpi_cpufreq_cpu_exit,
 776         .resume = acpi_cpufreq_resume,
 777         .name = "acpi-cpufreq",
 778         .owner = THIS_MODULE,
 779         .attr = acpi_cpufreq_attr,
 780 };
 781
 782 static int __init acpi_cpufreq_init(void)
 783 {
 784         int ret;
 785
 786         dprintk("acpi_cpufreq_init\n");
 787
 788         ret = acpi_cpufreq_early_init();
 789         if (ret)
 790                 return ret;
 791
 792         return cpufreq_register_driver(&acpi_cpufreq_driver);
 793 }
 794
 795 static void __exit acpi_cpufreq_exit(void)
 796 {
 797         dprintk("acpi_cpufreq_exit\n");
 798
 799         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 800
 801         free_percpu(acpi_perf_data);
 802
 803         return;
 804 }
 805
 806 module_param(acpi_pstate_strict, uint, 0644);
 807 MODULE_PARM_DESC(acpi_pstate_strict,
 808         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 809         "performed during frequency changes.");
 810
 811 late_initcall(acpi_cpufreq_init);
 812 module_exit(acpi_cpufreq_exit);
 813
 814 MODULE_ALIAS("acpi");