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