git.oblomov.eu Git - linux-2.6/blob - 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 struct acpi_cpufreq_data *drv_data[NR_CPUS];
  71 /* acpi_perf_data is a pointer to percpu data. */
  72 static struct acpi_processor_performance *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         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
  83             !cpu_has(cpu, X86_FEATURE_EST))
  84                 return 0;
  85
  86         return 1;
  87 }
  88
  89 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  90 {
  91         struct acpi_processor_performance *perf;
  92         int i;
  93
  94         perf = data->acpi_data;
  95
  96         for (i=0; i<perf->state_count; i++) {
  97                 if (value == perf->states[i].status)
  98                         return data->freq_table[i].frequency;
  99         }
 100         return 0;
 101 }
 102
 103 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 104 {
 105         int i;
 106         struct acpi_processor_performance *perf;
 107
 108         msr &= INTEL_MSR_RANGE;
 109         perf = data->acpi_data;
 110
 111         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 112                 if (msr == perf->states[data->freq_table[i].index].status)
 113                         return data->freq_table[i].frequency;
 114         }
 115         return data->freq_table[0].frequency;
 116 }
 117
 118 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 119 {
 120         switch (data->cpu_feature) {
 121         case SYSTEM_INTEL_MSR_CAPABLE:
 122                 return extract_msr(val, data);
 123         case SYSTEM_IO_CAPABLE:
 124                 return extract_io(val, data);
 125         default:
 126                 return 0;
 127         }
 128 }
 129
 130 struct msr_addr {
 131         u32 reg;
 132 };
 133
 134 struct io_addr {
 135         u16 port;
 136         u8 bit_width;
 137 };
 138
 139 typedef union {
 140         struct msr_addr msr;
 141         struct io_addr io;
 142 } drv_addr_union;
 143
 144 struct drv_cmd {
 145         unsigned int type;
 146         cpumask_t mask;
 147         drv_addr_union addr;
 148         u32 val;
 149 };
 150
 151 static void do_drv_read(struct drv_cmd *cmd)
 152 {
 153         u32 h;
 154
 155         switch (cmd->type) {
 156         case SYSTEM_INTEL_MSR_CAPABLE:
 157                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 158                 break;
 159         case SYSTEM_IO_CAPABLE:
 160                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 161                                 &cmd->val,
 162                                 (u32)cmd->addr.io.bit_width);
 163                 break;
 164         default:
 165                 break;
 166         }
 167 }
 168
 169 static void do_drv_write(struct drv_cmd *cmd)
 170 {
 171         u32 lo, hi;
 172
 173         switch (cmd->type) {
 174         case SYSTEM_INTEL_MSR_CAPABLE:
 175                 rdmsr(cmd->addr.msr.reg, lo, hi);
 176                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
 177                 wrmsr(cmd->addr.msr.reg, lo, hi);
 178                 break;
 179         case SYSTEM_IO_CAPABLE:
 180                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 181                                 cmd->val,
 182                                 (u32)cmd->addr.io.bit_width);
 183                 break;
 184         default:
 185                 break;
 186         }
 187 }
 188
 189 static void drv_read(struct drv_cmd *cmd)
 190 {
 191         cpumask_t saved_mask = current->cpus_allowed;
 192         cmd->val = 0;
 193
 194         set_cpus_allowed(current, cmd->mask);
 195         do_drv_read(cmd);
 196         set_cpus_allowed(current, saved_mask);
 197 }
 198
 199 static void drv_write(struct drv_cmd *cmd)
 200 {
 201         cpumask_t saved_mask = current->cpus_allowed;
 202         unsigned int i;
 203
 204         for_each_cpu_mask(i, cmd->mask) {
 205                 set_cpus_allowed(current, cpumask_of_cpu(i));
 206                 do_drv_write(cmd);
 207         }
 208
 209         set_cpus_allowed(current, saved_mask);
 210         return;
 211 }
 212
 213 static u32 get_cur_val(cpumask_t mask)
 214 {
 215         struct acpi_processor_performance *perf;
 216         struct drv_cmd cmd;
 217
 218         if (unlikely(cpus_empty(mask)))
 219                 return 0;
 220
 221         switch (drv_data[first_cpu(mask)]->cpu_feature) {
 222         case SYSTEM_INTEL_MSR_CAPABLE:
 223                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 224                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 225                 break;
 226         case SYSTEM_IO_CAPABLE:
 227                 cmd.type = SYSTEM_IO_CAPABLE;
 228                 perf = drv_data[first_cpu(mask)]->acpi_data;
 229                 cmd.addr.io.port = perf->control_register.address;
 230                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 231                 break;
 232         default:
 233                 return 0;
 234         }
 235
 236         cmd.mask = mask;
 237
 238         drv_read(&cmd);
 239
 240         dprintk("get_cur_val = %u\n", cmd.val);
 241
 242         return cmd.val;
 243 }
 244
 245 /*
 246  * Return the measured active (C0) frequency on this CPU since last call
 247  * to this function.
 248  * Input: cpu number
 249  * Return: Average CPU frequency in terms of max frequency (zero on error)
 250  *
 251  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 252  * over a period of time, while CPU is in C0 state.
 253  * IA32_MPERF counts at the rate of max advertised frequency
 254  * IA32_APERF counts at the rate of actual CPU frequency
 255  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 256  * no meaning should be associated with absolute values of these MSRs.
 257  */
 258 static unsigned int get_measured_perf(unsigned int cpu)
 259 {
 260         union {
 261                 struct {
 262                         u32 lo;
 263                         u32 hi;
 264                 } split;
 265                 u64 whole;
 266         } aperf_cur, mperf_cur;
 267
 268         cpumask_t saved_mask;
 269         unsigned int perf_percent;
 270         unsigned int retval;
 271
 272         saved_mask = current->cpus_allowed;
 273         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 274         if (get_cpu() != cpu) {
 275                 /* We were not able to run on requested processor */
 276                 put_cpu();
 277                 return 0;
 278         }
 279
 280         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
 281         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
 282
 283         wrmsr(MSR_IA32_APERF, 0,0);
 284         wrmsr(MSR_IA32_MPERF, 0,0);
 285
 286 #ifdef __i386__
 287         /*
 288          * We dont want to do 64 bit divide with 32 bit kernel
 289          * Get an approximate value. Return failure in case we cannot get
 290          * an approximate value.
 291          */
 292         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
 293                 int shift_count;
 294                 u32 h;
 295
 296                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
 297                 shift_count = fls(h);
 298
 299                 aperf_cur.whole >>= shift_count;
 300                 mperf_cur.whole >>= shift_count;
 301         }
 302
 303         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
 304                 int shift_count = 7;
 305                 aperf_cur.split.lo >>= shift_count;
 306                 mperf_cur.split.lo >>= shift_count;
 307         }
 308
 309         if (aperf_cur.split.lo && mperf_cur.split.lo)
 310                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
 311         else
 312                 perf_percent = 0;
 313
 314 #else
 315         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
 316                 int shift_count = 7;
 317                 aperf_cur.whole >>= shift_count;
 318                 mperf_cur.whole >>= shift_count;
 319         }
 320
 321         if (aperf_cur.whole && mperf_cur.whole)
 322                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
 323         else
 324                 perf_percent = 0;
 325
 326 #endif
 327
 328         retval = drv_data[cpu]->max_freq * perf_percent / 100;
 329
 330         put_cpu();
 331         set_cpus_allowed(current, saved_mask);
 332
 333         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
 334         return retval;
 335 }
 336
 337 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 338 {
 339         struct acpi_cpufreq_data *data = drv_data[cpu];
 340         unsigned int freq;
 341
 342         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 343
 344         if (unlikely(data == NULL ||
 345                      data->acpi_data == NULL || data->freq_table == NULL)) {
 346                 return 0;
 347         }
 348
 349         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
 350         dprintk("cur freq = %u\n", freq);
 351
 352         return freq;
 353 }
 354
 355 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
 356                                 struct acpi_cpufreq_data *data)
 357 {
 358         unsigned int cur_freq;
 359         unsigned int i;
 360
 361         for (i=0; i<100; i++) {
 362                 cur_freq = extract_freq(get_cur_val(mask), data);
 363                 if (cur_freq == freq)
 364                         return 1;
 365                 udelay(10);
 366         }
 367         return 0;
 368 }
 369
 370 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 371                                unsigned int target_freq, unsigned int relation)
 372 {
 373         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 374         struct acpi_processor_performance *perf;
 375         struct cpufreq_freqs freqs;
 376         cpumask_t online_policy_cpus;
 377         struct drv_cmd cmd;
 378         unsigned int next_state = 0; /* Index into freq_table */
 379         unsigned int next_perf_state = 0; /* Index into perf table */
 380         unsigned int i;
 381         int result = 0;
 382
 383         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 384
 385         if (unlikely(data == NULL ||
 386              data->acpi_data == NULL || data->freq_table == NULL)) {
 387                 return -ENODEV;
 388         }
 389
 390         perf = data->acpi_data;
 391         result = cpufreq_frequency_table_target(policy,
 392                                                 data->freq_table,
 393                                                 target_freq,
 394                                                 relation, &next_state);
 395         if (unlikely(result))
 396                 return -ENODEV;
 397
 398 #ifdef CONFIG_HOTPLUG_CPU
 399         /* cpufreq holds the hotplug lock, so we are safe from here on */
 400         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 401 #else
 402         online_policy_cpus = policy->cpus;
 403 #endif
 404
 405         next_perf_state = data->freq_table[next_state].index;
 406         if (perf->state == next_perf_state) {
 407                 if (unlikely(data->resume)) {
 408                         dprintk("Called after resume, resetting to P%d\n",
 409                                 next_perf_state);
 410                         data->resume = 0;
 411                 } else {
 412                         dprintk("Already at target state (P%d)\n",
 413                                 next_perf_state);
 414                         return 0;
 415                 }
 416         }
 417
 418         switch (data->cpu_feature) {
 419         case SYSTEM_INTEL_MSR_CAPABLE:
 420                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 421                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 422                 cmd.val = (u32) perf->states[next_perf_state].control;
 423                 break;
 424         case SYSTEM_IO_CAPABLE:
 425                 cmd.type = SYSTEM_IO_CAPABLE;
 426                 cmd.addr.io.port = perf->control_register.address;
 427                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 428                 cmd.val = (u32) perf->states[next_perf_state].control;
 429                 break;
 430         default:
 431                 return -ENODEV;
 432         }
 433
 434         cpus_clear(cmd.mask);
 435
 436         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 437                 cmd.mask = online_policy_cpus;
 438         else
 439                 cpu_set(policy->cpu, cmd.mask);
 440
 441         freqs.old = perf->states[perf->state].core_frequency * 1000;
 442         freqs.new = data->freq_table[next_state].frequency;
 443         for_each_cpu_mask(i, cmd.mask) {
 444                 freqs.cpu = i;
 445                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 446         }
 447
 448         drv_write(&cmd);
 449
 450         if (acpi_pstate_strict) {
 451                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 452                         dprintk("acpi_cpufreq_target failed (%d)\n",
 453                                 policy->cpu);
 454                         return -EAGAIN;
 455                 }
 456         }
 457
 458         for_each_cpu_mask(i, cmd.mask) {
 459                 freqs.cpu = i;
 460                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 461         }
 462         perf->state = next_perf_state;
 463
 464         return result;
 465 }
 466
 467 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 468 {
 469         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 470
 471         dprintk("acpi_cpufreq_verify\n");
 472
 473         return cpufreq_frequency_table_verify(policy, data->freq_table);
 474 }
 475
 476 static unsigned long
 477 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 478 {
 479         struct acpi_processor_performance *perf = data->acpi_data;
 480
 481         if (cpu_khz) {
 482                 /* search the closest match to cpu_khz */
 483                 unsigned int i;
 484                 unsigned long freq;
 485                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 486
 487                 for (i=0; i<(perf->state_count-1); i++) {
 488                         freq = freqn;
 489                         freqn = perf->states[i+1].core_frequency * 1000;
 490                         if ((2 * cpu_khz) > (freqn + freq)) {
 491                                 perf->state = i;
 492                                 return freq;
 493                         }
 494                 }
 495                 perf->state = perf->state_count-1;
 496                 return freqn;
 497         } else {
 498                 /* assume CPU is at P0... */
 499                 perf->state = 0;
 500                 return perf->states[0].core_frequency * 1000;
 501         }
 502 }
 503
 504 /*
 505  * acpi_cpufreq_early_init - initialize ACPI P-States library
 506  *
 507  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 508  * in order to determine correct frequency and voltage pairings. We can
 509  * do _PDC and _PSD and find out the processor dependency for the
 510  * actual init that will happen later...
 511  */
 512 static int __init acpi_cpufreq_early_init(void)
 513 {
 514         dprintk("acpi_cpufreq_early_init\n");
 515
 516         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 517         if (!acpi_perf_data) {
 518                 dprintk("Memory allocation error for acpi_perf_data.\n");
 519                 return -ENOMEM;
 520         }
 521
 522         /* Do initialization in ACPI core */
 523         acpi_processor_preregister_performance(acpi_perf_data);
 524         return 0;
 525 }
 526
 527 #ifdef CONFIG_SMP
 528 /*
 529  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 530  * or do it in BIOS firmware and won't inform about it to OS. If not
 531  * detected, this has a side effect of making CPU run at a different speed
 532  * than OS intended it to run at. Detect it and handle it cleanly.
 533  */
 534 static int bios_with_sw_any_bug;
 535
 536 static int sw_any_bug_found(const struct dmi_system_id *d)
 537 {
 538         bios_with_sw_any_bug = 1;
 539         return 0;
 540 }
 541
 542 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 543         {
 544                 .callback = sw_any_bug_found,
 545                 .ident = "Supermicro Server X6DLP",
 546                 .matches = {
 547                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 548                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 549                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 550                 },
 551         },
 552         { }
 553 };
 554 #endif
 555
 556 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 557 {
 558         unsigned int i;
 559         unsigned int valid_states = 0;
 560         unsigned int cpu = policy->cpu;
 561         struct acpi_cpufreq_data *data;
 562         unsigned int result = 0;
 563         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 564         struct acpi_processor_performance *perf;
 565
 566         dprintk("acpi_cpufreq_cpu_init\n");
 567
 568         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 569         if (!data)
 570                 return -ENOMEM;
 571
 572         data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
 573         drv_data[cpu] = data;
 574
 575         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 576                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 577
 578         result = acpi_processor_register_performance(data->acpi_data, cpu);
 579         if (result)
 580                 goto err_free;
 581
 582         perf = data->acpi_data;
 583         policy->shared_type = perf->shared_type;
 584
 585         /*
 586          * Will let policy->cpus know about dependency only when software
 587          * coordination is required.
 588          */
 589         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 590             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 591                 policy->cpus = perf->shared_cpu_map;
 592         }
 593
 594 #ifdef CONFIG_SMP
 595         dmi_check_system(sw_any_bug_dmi_table);
 596         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 597                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 598                 policy->cpus = per_cpu(cpu_core_map, cpu);
 599         }
 600 #endif
 601
 602         /* capability check */
 603         if (perf->state_count <= 1) {
 604                 dprintk("No P-States\n");
 605                 result = -ENODEV;
 606                 goto err_unreg;
 607         }
 608
 609         if (perf->control_register.space_id != perf->status_register.space_id) {
 610                 result = -ENODEV;
 611                 goto err_unreg;
 612         }
 613
 614         switch (perf->control_register.space_id) {
 615         case ACPI_ADR_SPACE_SYSTEM_IO:
 616                 dprintk("SYSTEM IO addr space\n");
 617                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 618                 break;
 619         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 620                 dprintk("HARDWARE addr space\n");
 621                 if (!check_est_cpu(cpu)) {
 622                         result = -ENODEV;
 623                         goto err_unreg;
 624                 }
 625                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 626                 break;
 627         default:
 628                 dprintk("Unknown addr space %d\n",
 629                         (u32) (perf->control_register.space_id));
 630                 result = -ENODEV;
 631                 goto err_unreg;
 632         }
 633
 634         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 635                     (perf->state_count+1), GFP_KERNEL);
 636         if (!data->freq_table) {
 637                 result = -ENOMEM;
 638                 goto err_unreg;
 639         }
 640
 641         /* detect transition latency */
 642         policy->cpuinfo.transition_latency = 0;
 643         for (i=0; i<perf->state_count; i++) {
 644                 if ((perf->states[i].transition_latency * 1000) >
 645                     policy->cpuinfo.transition_latency)
 646                         policy->cpuinfo.transition_latency =
 647                             perf->states[i].transition_latency * 1000;
 648         }
 649
 650         data->max_freq = perf->states[0].core_frequency * 1000;
 651         /* table init */
 652         for (i=0; i<perf->state_count; i++) {
 653                 if (i>0 && perf->states[i].core_frequency >=
 654                     data->freq_table[valid_states-1].frequency / 1000)
 655                         continue;
 656
 657                 data->freq_table[valid_states].index = i;
 658                 data->freq_table[valid_states].frequency =
 659                     perf->states[i].core_frequency * 1000;
 660                 valid_states++;
 661         }
 662         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 663         perf->state = 0;
 664
 665         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 666         if (result)
 667                 goto err_freqfree;
 668
 669         switch (perf->control_register.space_id) {
 670         case ACPI_ADR_SPACE_SYSTEM_IO:
 671                 /* Current speed is unknown and not detectable by IO port */
 672                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 673                 break;
 674         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 675                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 676                 policy->cur = get_cur_freq_on_cpu(cpu);
 677                 break;
 678         default:
 679                 break;
 680         }
 681
 682         /* notify BIOS that we exist */
 683         acpi_processor_notify_smm(THIS_MODULE);
 684
 685         /* Check for APERF/MPERF support in hardware */
 686         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
 687                 unsigned int ecx;
 688                 ecx = cpuid_ecx(6);
 689                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
 690                         acpi_cpufreq_driver.getavg = get_measured_perf;
 691         }
 692
 693         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 694         for (i = 0; i < perf->state_count; i++)
 695                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 696                         (i == perf->state ? '*' : ' '), i,
 697                         (u32) perf->states[i].core_frequency,
 698                         (u32) perf->states[i].power,
 699                         (u32) perf->states[i].transition_latency);
 700
 701         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 702
 703         /*
 704          * the first call to ->target() should result in us actually
 705          * writing something to the appropriate registers.
 706          */
 707         data->resume = 1;
 708
 709         return result;
 710
 711 err_freqfree:
 712         kfree(data->freq_table);
 713 err_unreg:
 714         acpi_processor_unregister_performance(perf, cpu);
 715 err_free:
 716         kfree(data);
 717         drv_data[cpu] = NULL;
 718
 719         return result;
 720 }
 721
 722 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 723 {
 724         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 725
 726         dprintk("acpi_cpufreq_cpu_exit\n");
 727
 728         if (data) {
 729                 cpufreq_frequency_table_put_attr(policy->cpu);
 730                 drv_data[policy->cpu] = NULL;
 731                 acpi_processor_unregister_performance(data->acpi_data,
 732                                                       policy->cpu);
 733                 kfree(data);
 734         }
 735
 736         return 0;
 737 }
 738
 739 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 740 {
 741         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 742
 743         dprintk("acpi_cpufreq_resume\n");
 744
 745         data->resume = 1;
 746
 747         return 0;
 748 }
 749
 750 static struct freq_attr *acpi_cpufreq_attr[] = {
 751         &cpufreq_freq_attr_scaling_available_freqs,
 752         NULL,
 753 };
 754
 755 static struct cpufreq_driver acpi_cpufreq_driver = {
 756         .verify = acpi_cpufreq_verify,
 757         .target = acpi_cpufreq_target,
 758         .init = acpi_cpufreq_cpu_init,
 759         .exit = acpi_cpufreq_cpu_exit,
 760         .resume = acpi_cpufreq_resume,
 761         .name = "acpi-cpufreq",
 762         .owner = THIS_MODULE,
 763         .attr = acpi_cpufreq_attr,
 764 };
 765
 766 static int __init acpi_cpufreq_init(void)
 767 {
 768         int ret;
 769
 770         dprintk("acpi_cpufreq_init\n");
 771
 772         ret = acpi_cpufreq_early_init();
 773         if (ret)
 774                 return ret;
 775
 776         return cpufreq_register_driver(&acpi_cpufreq_driver);
 777 }
 778
 779 static void __exit acpi_cpufreq_exit(void)
 780 {
 781         dprintk("acpi_cpufreq_exit\n");
 782
 783         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 784
 785         free_percpu(acpi_perf_data);
 786
 787         return;
 788 }
 789
 790 module_param(acpi_pstate_strict, uint, 0644);
 791 MODULE_PARM_DESC(acpi_pstate_strict,
 792         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 793         "performed during frequency changes.");
 794
 795 late_initcall(acpi_cpufreq_init);
 796 module_exit(acpi_cpufreq_exit);
 797
 798 MODULE_ALIAS("acpi");