drivers/cpufreq/acpi-cpufreq.c

   1 /*
   2  * acpi-cpufreq.c - ACPI Processor P-States Driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *
   9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or (at
  14  *  your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful, but
  17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *  General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with this program; if not, write to the Free Software Foundation, Inc.,
  23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  24  *
  25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/smp.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/compiler.h>
  35 #include <linux/dmi.h>
  36 #include <linux/slab.h>
  37
  38 #include <linux/acpi.h>
  39 #include <linux/io.h>
  40 #include <linux/delay.h>
  41 #include <linux/uaccess.h>
  42
  43 #include <acpi/processor.h>
  44
  45 #include <asm/msr.h>
  46 #include <asm/processor.h>
  47 #include <asm/cpufeature.h>
  48 #include "mperf.h"
  49
  50 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  51 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  52 MODULE_LICENSE("GPL");
  53
  54 #define PFX "acpi-cpufreq: "
  55
  56 enum {
  57         UNDEFINED_CAPABLE = 0,
  58         SYSTEM_INTEL_MSR_CAPABLE,
  59         SYSTEM_AMD_MSR_CAPABLE,
  60         SYSTEM_IO_CAPABLE,
  61 };
  62
  63 #define INTEL_MSR_RANGE         (0xffff)
  64 #define AMD_MSR_RANGE           (0x7)
  65
  66 struct acpi_cpufreq_data {
  67         struct acpi_processor_performance *acpi_data;
  68         struct cpufreq_frequency_table *freq_table;
  69         unsigned int resume;
  70         unsigned int cpu_feature;
  71 };
  72
  73 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
  74
  75 /* acpi_perf_data is a pointer to percpu data. */
  76 static struct acpi_processor_performance __percpu *acpi_perf_data;
  77
  78 static struct cpufreq_driver acpi_cpufreq_driver;
  79
  80 static unsigned int acpi_pstate_strict;
  81
  82 static int check_est_cpu(unsigned int cpuid)
  83 {
  84         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  85
  86         return cpu_has(cpu, X86_FEATURE_EST);
  87 }
  88
  89 static int check_amd_hwpstate_cpu(unsigned int cpuid)
  90 {
  91         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
  92
  93         return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
  94 }
  95
  96 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  97 {
  98         struct acpi_processor_performance *perf;
  99         int i;
 100
 101         perf = data->acpi_data;
 102
 103         for (i = 0; i < perf->state_count; i++) {
 104                 if (value == perf->states[i].status)
 105                         return data->freq_table[i].frequency;
 106         }
 107         return 0;
 108 }
 109
 110 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 111 {
 112         int i;
 113         struct acpi_processor_performance *perf;
 114
 115         if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
 116                 msr &= AMD_MSR_RANGE;
 117         else
 118                 msr &= INTEL_MSR_RANGE;
 119
 120         perf = data->acpi_data;
 121
 122         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 123                 if (msr == perf->states[data->freq_table[i].index].status)
 124                         return data->freq_table[i].frequency;
 125         }
 126         return data->freq_table[0].frequency;
 127 }
 128
 129 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 130 {
 131         switch (data->cpu_feature) {
 132         case SYSTEM_INTEL_MSR_CAPABLE:
 133         case SYSTEM_AMD_MSR_CAPABLE:
 134                 return extract_msr(val, data);
 135         case SYSTEM_IO_CAPABLE:
 136                 return extract_io(val, data);
 137         default:
 138                 return 0;
 139         }
 140 }
 141
 142 struct msr_addr {
 143         u32 reg;
 144 };
 145
 146 struct io_addr {
 147         u16 port;
 148         u8 bit_width;
 149 };
 150
 151 struct drv_cmd {
 152         unsigned int type;
 153         const struct cpumask *mask;
 154         union {
 155                 struct msr_addr msr;
 156                 struct io_addr io;
 157         } addr;
 158         u32 val;
 159 };
 160
 161 /* Called via smp_call_function_single(), on the target CPU */
 162 static void do_drv_read(void *_cmd)
 163 {
 164         struct drv_cmd *cmd = _cmd;
 165         u32 h;
 166
 167         switch (cmd->type) {
 168         case SYSTEM_INTEL_MSR_CAPABLE:
 169         case SYSTEM_AMD_MSR_CAPABLE:
 170                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 171                 break;
 172         case SYSTEM_IO_CAPABLE:
 173                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 174                                 &cmd->val,
 175                                 (u32)cmd->addr.io.bit_width);
 176                 break;
 177         default:
 178                 break;
 179         }
 180 }
 181
 182 /* Called via smp_call_function_many(), on the target CPUs */
 183 static void do_drv_write(void *_cmd)
 184 {
 185         struct drv_cmd *cmd = _cmd;
 186         u32 lo, hi;
 187
 188         switch (cmd->type) {
 189         case SYSTEM_INTEL_MSR_CAPABLE:
 190                 rdmsr(cmd->addr.msr.reg, lo, hi);
 191                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
 192                 wrmsr(cmd->addr.msr.reg, lo, hi);
 193                 break;
 194         case SYSTEM_AMD_MSR_CAPABLE:
 195                 wrmsr(cmd->addr.msr.reg, cmd->val, 0);
 196                 break;
 197         case SYSTEM_IO_CAPABLE:
 198                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 199                                 cmd->val,
 200                                 (u32)cmd->addr.io.bit_width);
 201                 break;
 202         default:
 203                 break;
 204         }
 205 }
 206
 207 static void drv_read(struct drv_cmd *cmd)
 208 {
 209         int err;
 210         cmd->val = 0;
 211
 212         err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
 213         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
 214 }
 215
 216 static void drv_write(struct drv_cmd *cmd)
 217 {
 218         int this_cpu;
 219
 220         this_cpu = get_cpu();
 221         if (cpumask_test_cpu(this_cpu, cmd->mask))
 222                 do_drv_write(cmd);
 223         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
 224         put_cpu();
 225 }
 226
 227 static u32 get_cur_val(const struct cpumask *mask)
 228 {
 229         struct acpi_processor_performance *perf;
 230         struct drv_cmd cmd;
 231
 232         if (unlikely(cpumask_empty(mask)))
 233                 return 0;
 234
 235         switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
 236         case SYSTEM_INTEL_MSR_CAPABLE:
 237                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 238                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 239                 break;
 240         case SYSTEM_AMD_MSR_CAPABLE:
 241                 cmd.type = SYSTEM_AMD_MSR_CAPABLE;
 242                 cmd.addr.msr.reg = MSR_AMD_PERF_STATUS;
 243                 break;
 244         case SYSTEM_IO_CAPABLE:
 245                 cmd.type = SYSTEM_IO_CAPABLE;
 246                 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
 247                 cmd.addr.io.port = perf->control_register.address;
 248                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 249                 break;
 250         default:
 251                 return 0;
 252         }
 253
 254         cmd.mask = mask;
 255         drv_read(&cmd);
 256
 257         pr_debug("get_cur_val = %u\n", cmd.val);
 258
 259         return cmd.val;
 260 }
 261
 262 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 263 {
 264         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
 265         unsigned int freq;
 266         unsigned int cached_freq;
 267
 268         pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
 269
 270         if (unlikely(data == NULL ||
 271                      data->acpi_data == NULL || data->freq_table == NULL)) {
 272                 return 0;
 273         }
 274
 275         cached_freq = data->freq_table[data->acpi_data->state].frequency;
 276         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
 277         if (freq != cached_freq) {
 278                 /*
 279                  * The dreaded BIOS frequency change behind our back.
 280                  * Force set the frequency on next target call.
 281                  */
 282                 data->resume = 1;
 283         }
 284
 285         pr_debug("cur freq = %u\n", freq);
 286
 287         return freq;
 288 }
 289
 290 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
 291                                 struct acpi_cpufreq_data *data)
 292 {
 293         unsigned int cur_freq;
 294         unsigned int i;
 295
 296         for (i = 0; i < 100; i++) {
 297                 cur_freq = extract_freq(get_cur_val(mask), data);
 298                 if (cur_freq == freq)
 299                         return 1;
 300                 udelay(10);
 301         }
 302         return 0;
 303 }
 304
 305 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 306                                unsigned int target_freq, unsigned int relation)
 307 {
 308         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 309         struct acpi_processor_performance *perf;
 310         struct cpufreq_freqs freqs;
 311         struct drv_cmd cmd;
 312         unsigned int next_state = 0; /* Index into freq_table */
 313         unsigned int next_perf_state = 0; /* Index into perf table */
 314         unsigned int i;
 315         int result = 0;
 316
 317         pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 318
 319         if (unlikely(data == NULL ||
 320              data->acpi_data == NULL || data->freq_table == NULL)) {
 321                 return -ENODEV;
 322         }
 323
 324         perf = data->acpi_data;
 325         result = cpufreq_frequency_table_target(policy,
 326                                                 data->freq_table,
 327                                                 target_freq,
 328                                                 relation, &next_state);
 329         if (unlikely(result)) {
 330                 result = -ENODEV;
 331                 goto out;
 332         }
 333
 334         next_perf_state = data->freq_table[next_state].index;
 335         if (perf->state == next_perf_state) {
 336                 if (unlikely(data->resume)) {
 337                         pr_debug("Called after resume, resetting to P%d\n",
 338                                 next_perf_state);
 339                         data->resume = 0;
 340                 } else {
 341                         pr_debug("Already at target state (P%d)\n",
 342                                 next_perf_state);
 343                         goto out;
 344                 }
 345         }
 346
 347         switch (data->cpu_feature) {
 348         case SYSTEM_INTEL_MSR_CAPABLE:
 349                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 350                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 351                 cmd.val = (u32) perf->states[next_perf_state].control;
 352                 break;
 353         case SYSTEM_AMD_MSR_CAPABLE:
 354                 cmd.type = SYSTEM_AMD_MSR_CAPABLE;
 355                 cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
 356                 cmd.val = (u32) perf->states[next_perf_state].control;
 357                 break;
 358         case SYSTEM_IO_CAPABLE:
 359                 cmd.type = SYSTEM_IO_CAPABLE;
 360                 cmd.addr.io.port = perf->control_register.address;
 361                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 362                 cmd.val = (u32) perf->states[next_perf_state].control;
 363                 break;
 364         default:
 365                 result = -ENODEV;
 366                 goto out;
 367         }
 368
 369         /* cpufreq holds the hotplug lock, so we are safe from here on */
 370         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 371                 cmd.mask = policy->cpus;
 372         else
 373                 cmd.mask = cpumask_of(policy->cpu);
 374
 375         freqs.old = perf->states[perf->state].core_frequency * 1000;
 376         freqs.new = data->freq_table[next_state].frequency;
 377         for_each_cpu(i, policy->cpus) {
 378                 freqs.cpu = i;
 379                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 380         }
 381
 382         drv_write(&cmd);
 383
 384         if (acpi_pstate_strict) {
 385                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 386                         pr_debug("acpi_cpufreq_target failed (%d)\n",
 387                                 policy->cpu);
 388                         result = -EAGAIN;
 389                         goto out;
 390                 }
 391         }
 392
 393         for_each_cpu(i, policy->cpus) {
 394                 freqs.cpu = i;
 395                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 396         }
 397         perf->state = next_perf_state;
 398
 399 out:
 400         return result;
 401 }
 402
 403 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 404 {
 405         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 406
 407         pr_debug("acpi_cpufreq_verify\n");
 408
 409         return cpufreq_frequency_table_verify(policy, data->freq_table);
 410 }
 411
 412 static unsigned long
 413 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 414 {
 415         struct acpi_processor_performance *perf = data->acpi_data;
 416
 417         if (cpu_khz) {
 418                 /* search the closest match to cpu_khz */
 419                 unsigned int i;
 420                 unsigned long freq;
 421                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 422
 423                 for (i = 0; i < (perf->state_count-1); i++) {
 424                         freq = freqn;
 425                         freqn = perf->states[i+1].core_frequency * 1000;
 426                         if ((2 * cpu_khz) > (freqn + freq)) {
 427                                 perf->state = i;
 428                                 return freq;
 429                         }
 430                 }
 431                 perf->state = perf->state_count-1;
 432                 return freqn;
 433         } else {
 434                 /* assume CPU is at P0... */
 435                 perf->state = 0;
 436                 return perf->states[0].core_frequency * 1000;
 437         }
 438 }
 439
 440 static void free_acpi_perf_data(void)
 441 {
 442         unsigned int i;
 443
 444         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 445         for_each_possible_cpu(i)
 446                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 447                                  ->shared_cpu_map);
 448         free_percpu(acpi_perf_data);
 449 }
 450
 451 /*
 452  * acpi_cpufreq_early_init - initialize ACPI P-States library
 453  *
 454  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 455  * in order to determine correct frequency and voltage pairings. We can
 456  * do _PDC and _PSD and find out the processor dependency for the
 457  * actual init that will happen later...
 458  */
 459 static int __init acpi_cpufreq_early_init(void)
 460 {
 461         unsigned int i;
 462         pr_debug("acpi_cpufreq_early_init\n");
 463
 464         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 465         if (!acpi_perf_data) {
 466                 pr_debug("Memory allocation error for acpi_perf_data.\n");
 467                 return -ENOMEM;
 468         }
 469         for_each_possible_cpu(i) {
 470                 if (!zalloc_cpumask_var_node(
 471                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 472                         GFP_KERNEL, cpu_to_node(i))) {
 473
 474                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 475                         free_acpi_perf_data();
 476                         return -ENOMEM;
 477                 }
 478         }
 479
 480         /* Do initialization in ACPI core */
 481         acpi_processor_preregister_performance(acpi_perf_data);
 482         return 0;
 483 }
 484
 485 #ifdef CONFIG_SMP
 486 /*
 487  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 488  * or do it in BIOS firmware and won't inform about it to OS. If not
 489  * detected, this has a side effect of making CPU run at a different speed
 490  * than OS intended it to run at. Detect it and handle it cleanly.
 491  */
 492 static int bios_with_sw_any_bug;
 493
 494 static int sw_any_bug_found(const struct dmi_system_id *d)
 495 {
 496         bios_with_sw_any_bug = 1;
 497         return 0;
 498 }
 499
 500 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 501         {
 502                 .callback = sw_any_bug_found,
 503                 .ident = "Supermicro Server X6DLP",
 504                 .matches = {
 505                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 506                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 507                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 508                 },
 509         },
 510         { }
 511 };
 512
 513 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
 514 {
 515         /* Intel Xeon Processor 7100 Series Specification Update
 516          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
 517          * AL30: A Machine Check Exception (MCE) Occurring during an
 518          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
 519          * Both Processor Cores to Lock Up. */
 520         if (c->x86_vendor == X86_VENDOR_INTEL) {
 521                 if ((c->x86 == 15) &&
 522                     (c->x86_model == 6) &&
 523                     (c->x86_mask == 8)) {
 524                         printk(KERN_INFO "acpi-cpufreq: Intel(R) "
 525                             "Xeon(R) 7100 Errata AL30, processors may "
 526                             "lock up on frequency changes: disabling "
 527                             "acpi-cpufreq.\n");
 528                         return -ENODEV;
 529                     }
 530                 }
 531         return 0;
 532 }
 533 #endif
 534
 535 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 536 {
 537         unsigned int i;
 538         unsigned int valid_states = 0;
 539         unsigned int cpu = policy->cpu;
 540         struct acpi_cpufreq_data *data;
 541         unsigned int result = 0;
 542         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 543         struct acpi_processor_performance *perf;
 544 #ifdef CONFIG_SMP
 545         static int blacklisted;
 546 #endif
 547
 548         pr_debug("acpi_cpufreq_cpu_init\n");
 549
 550 #ifdef CONFIG_SMP
 551         if (blacklisted)
 552                 return blacklisted;
 553         blacklisted = acpi_cpufreq_blacklist(c);
 554         if (blacklisted)
 555                 return blacklisted;
 556 #endif
 557
 558         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 559         if (!data)
 560                 return -ENOMEM;
 561
 562         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
 563         per_cpu(acfreq_data, cpu) = data;
 564
 565         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 566                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 567
 568         result = acpi_processor_register_performance(data->acpi_data, cpu);
 569         if (result)
 570                 goto err_free;
 571
 572         perf = data->acpi_data;
 573         policy->shared_type = perf->shared_type;
 574
 575         /*
 576          * Will let policy->cpus know about dependency only when software
 577          * coordination is required.
 578          */
 579         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 580             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 581                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
 582         }
 583         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
 584
 585 #ifdef CONFIG_SMP
 586         dmi_check_system(sw_any_bug_dmi_table);
 587         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
 588                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 589                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
 590         }
 591
 592         if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
 593                 cpumask_clear(policy->cpus);
 594                 cpumask_set_cpu(cpu, policy->cpus);
 595                 cpumask_copy(policy->related_cpus, cpu_sibling_mask(cpu));
 596                 policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
 597                 pr_info_once(PFX "overriding BIOS provided _PSD data\n");
 598         }
 599 #endif
 600
 601         /* capability check */
 602         if (perf->state_count <= 1) {
 603                 pr_debug("No P-States\n");
 604                 result = -ENODEV;
 605                 goto err_unreg;
 606         }
 607
 608         if (perf->control_register.space_id != perf->status_register.space_id) {
 609                 result = -ENODEV;
 610                 goto err_unreg;
 611         }
 612
 613         switch (perf->control_register.space_id) {
 614         case ACPI_ADR_SPACE_SYSTEM_IO:
 615                 pr_debug("SYSTEM IO addr space\n");
 616                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 617                 break;
 618         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 619                 pr_debug("HARDWARE addr space\n");
 620                 if (check_est_cpu(cpu)) {
 621                         data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 622                         break;
 623                 }
 624                 if (check_amd_hwpstate_cpu(cpu)) {
 625                         data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
 626                         break;
 627                 }
 628                 result = -ENODEV;
 629                 goto err_unreg;
 630         default:
 631                 pr_debug("Unknown addr space %d\n",
 632                         (u32) (perf->control_register.space_id));
 633                 result = -ENODEV;
 634                 goto err_unreg;
 635         }
 636
 637         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 638                     (perf->state_count+1), GFP_KERNEL);
 639         if (!data->freq_table) {
 640                 result = -ENOMEM;
 641                 goto err_unreg;
 642         }
 643
 644         /* detect transition latency */
 645         policy->cpuinfo.transition_latency = 0;
 646         for (i = 0; i < perf->state_count; i++) {
 647                 if ((perf->states[i].transition_latency * 1000) >
 648                     policy->cpuinfo.transition_latency)
 649                         policy->cpuinfo.transition_latency =
 650                             perf->states[i].transition_latency * 1000;
 651         }
 652
 653         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
 654         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
 655             policy->cpuinfo.transition_latency > 20 * 1000) {
 656                 policy->cpuinfo.transition_latency = 20 * 1000;
 657                 printk_once(KERN_INFO
 658                             "P-state transition latency capped at 20 uS\n");
 659         }
 660
 661         /* table init */
 662         for (i = 0; i < perf->state_count; i++) {
 663                 if (i > 0 && perf->states[i].core_frequency >=
 664                     data->freq_table[valid_states-1].frequency / 1000)
 665                         continue;
 666
 667                 data->freq_table[valid_states].index = i;
 668                 data->freq_table[valid_states].frequency =
 669                     perf->states[i].core_frequency * 1000;
 670                 valid_states++;
 671         }
 672         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 673         perf->state = 0;
 674
 675         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 676         if (result)
 677                 goto err_freqfree;
 678
 679         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
 680                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
 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 (boot_cpu_has(X86_FEATURE_APERFMPERF))
 700                 acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
 701
 702         pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
 703         for (i = 0; i < perf->state_count; i++)
 704                 pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 705                         (i == perf->state ? '*' : ' '), i,
 706                         (u32) perf->states[i].core_frequency,
 707                         (u32) perf->states[i].power,
 708                         (u32) perf->states[i].transition_latency);
 709
 710         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 711
 712         /*
 713          * the first call to ->target() should result in us actually
 714          * writing something to the appropriate registers.
 715          */
 716         data->resume = 1;
 717
 718         return result;
 719
 720 err_freqfree:
 721         kfree(data->freq_table);
 722 err_unreg:
 723         acpi_processor_unregister_performance(perf, cpu);
 724 err_free:
 725         kfree(data);
 726         per_cpu(acfreq_data, cpu) = NULL;
 727
 728         return result;
 729 }
 730
 731 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 732 {
 733         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 734
 735         pr_debug("acpi_cpufreq_cpu_exit\n");
 736
 737         if (data) {
 738                 cpufreq_frequency_table_put_attr(policy->cpu);
 739                 per_cpu(acfreq_data, policy->cpu) = NULL;
 740                 acpi_processor_unregister_performance(data->acpi_data,
 741                                                       policy->cpu);
 742                 kfree(data->freq_table);
 743                 kfree(data);
 744         }
 745
 746         return 0;
 747 }
 748
 749 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 750 {
 751         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 752
 753         pr_debug("acpi_cpufreq_resume\n");
 754
 755         data->resume = 1;
 756
 757         return 0;
 758 }
 759
 760 static struct freq_attr *acpi_cpufreq_attr[] = {
 761         &cpufreq_freq_attr_scaling_available_freqs,
 762         NULL,
 763 };
 764
 765 static struct cpufreq_driver acpi_cpufreq_driver = {
 766         .verify         = acpi_cpufreq_verify,
 767         .target         = acpi_cpufreq_target,
 768         .bios_limit     = acpi_processor_get_bios_limit,
 769         .init           = acpi_cpufreq_cpu_init,
 770         .exit           = acpi_cpufreq_cpu_exit,
 771         .resume         = acpi_cpufreq_resume,
 772         .name           = "acpi-cpufreq",
 773         .owner          = THIS_MODULE,
 774         .attr           = acpi_cpufreq_attr,
 775 };
 776
 777 static int __init acpi_cpufreq_init(void)
 778 {
 779         int ret;
 780
 781         if (acpi_disabled)
 782                 return 0;
 783
 784         pr_debug("acpi_cpufreq_init\n");
 785
 786         ret = acpi_cpufreq_early_init();
 787         if (ret)
 788                 return ret;
 789
 790         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
 791         if (ret)
 792                 free_acpi_perf_data();
 793
 794         return ret;
 795 }
 796
 797 static void __exit acpi_cpufreq_exit(void)
 798 {
 799         pr_debug("acpi_cpufreq_exit\n");
 800
 801         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 802
 803         free_acpi_perf_data();
 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");