arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c

   1 /*
   2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *
   9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or (at
  14  *  your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful, but
  17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *  General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with this program; if not, write to the Free Software Foundation, Inc.,
  23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  24  *
  25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/smp.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/compiler.h>
  35 #include <linux/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 static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
  72
  73 static struct cpufreq_driver acpi_cpufreq_driver;
  74
  75 static unsigned int acpi_pstate_strict;
  76
  77 static int check_est_cpu(unsigned int cpuid)
  78 {
  79         struct cpuinfo_x86 *cpu = &cpu_data[cpuid];
  80
  81         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
  82             !cpu_has(cpu, X86_FEATURE_EST))
  83                 return 0;
  84
  85         return 1;
  86 }
  87
  88 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
  89 {
  90         struct acpi_processor_performance *perf;
  91         int i;
  92
  93         perf = data->acpi_data;
  94
  95         for (i=0; i<perf->state_count; i++) {
  96                 if (value == perf->states[i].status)
  97                         return data->freq_table[i].frequency;
  98         }
  99         return 0;
 100 }
 101
 102 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
 103 {
 104         int i;
 105         struct acpi_processor_performance *perf;
 106
 107         msr &= INTEL_MSR_RANGE;
 108         perf = data->acpi_data;
 109
 110         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
 111                 if (msr == perf->states[data->freq_table[i].index].status)
 112                         return data->freq_table[i].frequency;
 113         }
 114         return data->freq_table[0].frequency;
 115 }
 116
 117 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 118 {
 119         switch (data->cpu_feature) {
 120         case SYSTEM_INTEL_MSR_CAPABLE:
 121                 return extract_msr(val, data);
 122         case SYSTEM_IO_CAPABLE:
 123                 return extract_io(val, data);
 124         default:
 125                 return 0;
 126         }
 127 }
 128
 129 static void wrport(u16 port, u8 bit_width, u32 value)
 130 {
 131         if (bit_width <= 8)
 132                 outb(value, port);
 133         else if (bit_width <= 16)
 134                 outw(value, port);
 135         else if (bit_width <= 32)
 136                 outl(value, port);
 137 }
 138
 139 static void rdport(u16 port, u8 bit_width, u32 * ret)
 140 {
 141         *ret = 0;
 142         if (bit_width <= 8)
 143                 *ret = inb(port);
 144         else if (bit_width <= 16)
 145                 *ret = inw(port);
 146         else if (bit_width <= 32)
 147                 *ret = inl(port);
 148 }
 149
 150 struct msr_addr {
 151         u32 reg;
 152 };
 153
 154 struct io_addr {
 155         u16 port;
 156         u8 bit_width;
 157 };
 158
 159 typedef union {
 160         struct msr_addr msr;
 161         struct io_addr io;
 162 } drv_addr_union;
 163
 164 struct drv_cmd {
 165         unsigned int type;
 166         cpumask_t mask;
 167         drv_addr_union addr;
 168         u32 val;
 169 };
 170
 171 static void do_drv_read(struct drv_cmd *cmd)
 172 {
 173         u32 h;
 174
 175         switch (cmd->type) {
 176         case SYSTEM_INTEL_MSR_CAPABLE:
 177                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 178                 break;
 179         case SYSTEM_IO_CAPABLE:
 180                 rdport(cmd->addr.io.port, cmd->addr.io.bit_width, &cmd->val);
 181                 break;
 182         default:
 183                 break;
 184         }
 185 }
 186
 187 static void do_drv_write(struct drv_cmd *cmd)
 188 {
 189         u32 h = 0;
 190
 191         switch (cmd->type) {
 192         case SYSTEM_INTEL_MSR_CAPABLE:
 193                 wrmsr(cmd->addr.msr.reg, cmd->val, h);
 194                 break;
 195         case SYSTEM_IO_CAPABLE:
 196                 wrport(cmd->addr.io.port, cmd->addr.io.bit_width, cmd->val);
 197                 break;
 198         default:
 199                 break;
 200         }
 201 }
 202
 203 static void drv_read(struct drv_cmd *cmd)
 204 {
 205         cpumask_t saved_mask = current->cpus_allowed;
 206         cmd->val = 0;
 207
 208         set_cpus_allowed(current, cmd->mask);
 209         do_drv_read(cmd);
 210         set_cpus_allowed(current, saved_mask);
 211 }
 212
 213 static void drv_write(struct drv_cmd *cmd)
 214 {
 215         cpumask_t saved_mask = current->cpus_allowed;
 216         unsigned int i;
 217
 218         for_each_cpu_mask(i, cmd->mask) {
 219                 set_cpus_allowed(current, cpumask_of_cpu(i));
 220                 do_drv_write(cmd);
 221         }
 222
 223         set_cpus_allowed(current, saved_mask);
 224         return;
 225 }
 226
 227 static u32 get_cur_val(cpumask_t mask)
 228 {
 229         struct acpi_processor_performance *perf;
 230         struct drv_cmd cmd;
 231
 232         if (unlikely(cpus_empty(mask)))
 233                 return 0;
 234
 235         switch (drv_data[first_cpu(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_IO_CAPABLE:
 241                 cmd.type = SYSTEM_IO_CAPABLE;
 242                 perf = drv_data[first_cpu(mask)]->acpi_data;
 243                 cmd.addr.io.port = perf->control_register.address;
 244                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 245                 break;
 246         default:
 247                 return 0;
 248         }
 249
 250         cmd.mask = mask;
 251
 252         drv_read(&cmd);
 253
 254         dprintk("get_cur_val = %u\n", cmd.val);
 255
 256         return cmd.val;
 257 }
 258
 259 /*
 260  * Return the measured active (C0) frequency on this CPU since last call
 261  * to this function.
 262  * Input: cpu number
 263  * Return: Average CPU frequency in terms of max frequency (zero on error)
 264  *
 265  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 266  * over a period of time, while CPU is in C0 state.
 267  * IA32_MPERF counts at the rate of max advertised frequency
 268  * IA32_APERF counts at the rate of actual CPU frequency
 269  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 270  * no meaning should be associated with absolute values of these MSRs.
 271  */
 272 static unsigned int get_measured_perf(unsigned int cpu)
 273 {
 274         union {
 275                 struct {
 276                         u32 lo;
 277                         u32 hi;
 278                 } split;
 279                 u64 whole;
 280         } aperf_cur, mperf_cur;
 281
 282         cpumask_t saved_mask;
 283         unsigned int perf_percent;
 284         unsigned int retval;
 285
 286         saved_mask = current->cpus_allowed;
 287         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 288         if (get_cpu() != cpu) {
 289                 /* We were not able to run on requested processor */
 290                 put_cpu();
 291                 return 0;
 292         }
 293
 294         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
 295         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
 296
 297         wrmsr(MSR_IA32_APERF, 0,0);
 298         wrmsr(MSR_IA32_MPERF, 0,0);
 299
 300 #ifdef __i386__
 301         /*
 302          * We dont want to do 64 bit divide with 32 bit kernel
 303          * Get an approximate value. Return failure in case we cannot get
 304          * an approximate value.
 305          */
 306         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
 307                 int shift_count;
 308                 u32 h;
 309
 310                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
 311                 shift_count = fls(h);
 312
 313                 aperf_cur.whole >>= shift_count;
 314                 mperf_cur.whole >>= shift_count;
 315         }
 316
 317         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
 318                 int shift_count = 7;
 319                 aperf_cur.split.lo >>= shift_count;
 320                 mperf_cur.split.lo >>= shift_count;
 321         }
 322
 323         if (aperf_cur.split.lo && mperf_cur.split.lo)
 324                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
 325         else
 326                 perf_percent = 0;
 327
 328 #else
 329         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
 330                 int shift_count = 7;
 331                 aperf_cur.whole >>= shift_count;
 332                 mperf_cur.whole >>= shift_count;
 333         }
 334
 335         if (aperf_cur.whole && mperf_cur.whole)
 336                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
 337         else
 338                 perf_percent = 0;
 339
 340 #endif
 341
 342         retval = drv_data[cpu]->max_freq * perf_percent / 100;
 343
 344         put_cpu();
 345         set_cpus_allowed(current, saved_mask);
 346
 347         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
 348         return retval;
 349 }
 350
 351 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 352 {
 353         struct acpi_cpufreq_data *data = drv_data[cpu];
 354         unsigned int freq;
 355
 356         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 357
 358         if (unlikely(data == NULL ||
 359                      data->acpi_data == NULL || data->freq_table == NULL)) {
 360                 return 0;
 361         }
 362
 363         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
 364         dprintk("cur freq = %u\n", freq);
 365
 366         return freq;
 367 }
 368
 369 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
 370                                 struct acpi_cpufreq_data *data)
 371 {
 372         unsigned int cur_freq;
 373         unsigned int i;
 374
 375         for (i=0; i<100; i++) {
 376                 cur_freq = extract_freq(get_cur_val(mask), data);
 377                 if (cur_freq == freq)
 378                         return 1;
 379                 udelay(10);
 380         }
 381         return 0;
 382 }
 383
 384 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 385                                unsigned int target_freq, unsigned int relation)
 386 {
 387         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 388         struct acpi_processor_performance *perf;
 389         struct cpufreq_freqs freqs;
 390         cpumask_t online_policy_cpus;
 391         struct drv_cmd cmd;
 392         unsigned int msr;
 393         unsigned int next_state = 0;
 394         unsigned int next_perf_state = 0;
 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                 msr =
 438                     (u32) perf->states[next_perf_state].
 439                     control & INTEL_MSR_RANGE;
 440                 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 441                 break;
 442         case SYSTEM_IO_CAPABLE:
 443                 cmd.type = SYSTEM_IO_CAPABLE;
 444                 cmd.addr.io.port = perf->control_register.address;
 445                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 446                 cmd.val = (u32) perf->states[next_perf_state].control;
 447                 break;
 448         default:
 449                 return -ENODEV;
 450         }
 451
 452         cpus_clear(cmd.mask);
 453
 454         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 455                 cmd.mask = online_policy_cpus;
 456         else
 457                 cpu_set(policy->cpu, cmd.mask);
 458
 459         freqs.old = data->freq_table[perf->state].frequency;
 460         freqs.new = data->freq_table[next_perf_state].frequency;
 461         for_each_cpu_mask(i, cmd.mask) {
 462                 freqs.cpu = i;
 463                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 464         }
 465
 466         drv_write(&cmd);
 467
 468         if (acpi_pstate_strict) {
 469                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 470                         dprintk("acpi_cpufreq_target failed (%d)\n",
 471                                 policy->cpu);
 472                         return -EAGAIN;
 473                 }
 474         }
 475
 476         for_each_cpu_mask(i, cmd.mask) {
 477                 freqs.cpu = i;
 478                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 479         }
 480         perf->state = next_perf_state;
 481
 482         return result;
 483 }
 484
 485 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 486 {
 487         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 488
 489         dprintk("acpi_cpufreq_verify\n");
 490
 491         return cpufreq_frequency_table_verify(policy, data->freq_table);
 492 }
 493
 494 static unsigned long
 495 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 496 {
 497         struct acpi_processor_performance *perf = data->acpi_data;
 498
 499         if (cpu_khz) {
 500                 /* search the closest match to cpu_khz */
 501                 unsigned int i;
 502                 unsigned long freq;
 503                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 504
 505                 for (i=0; i<(perf->state_count-1); i++) {
 506                         freq = freqn;
 507                         freqn = perf->states[i+1].core_frequency * 1000;
 508                         if ((2 * cpu_khz) > (freqn + freq)) {
 509                                 perf->state = i;
 510                                 return freq;
 511                         }
 512                 }
 513                 perf->state = perf->state_count-1;
 514                 return freqn;
 515         } else {
 516                 /* assume CPU is at P0... */
 517                 perf->state = 0;
 518                 return perf->states[0].core_frequency * 1000;
 519         }
 520 }
 521
 522 /*
 523  * acpi_cpufreq_early_init - initialize ACPI P-States library
 524  *
 525  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 526  * in order to determine correct frequency and voltage pairings. We can
 527  * do _PDC and _PSD and find out the processor dependency for the
 528  * actual init that will happen later...
 529  */
 530 static int acpi_cpufreq_early_init(void)
 531 {
 532         struct acpi_processor_performance *data;
 533         cpumask_t covered;
 534         unsigned int i, j;
 535
 536         dprintk("acpi_cpufreq_early_init\n");
 537
 538         for_each_possible_cpu(i) {
 539                 data = kzalloc(sizeof(struct acpi_processor_performance),
 540                                GFP_KERNEL);
 541                 if (!data) {
 542                         for_each_cpu_mask(j, covered) {
 543                                 kfree(acpi_perf_data[j]);
 544                                 acpi_perf_data[j] = NULL;
 545                         }
 546                         return -ENOMEM;
 547                 }
 548                 acpi_perf_data[i] = data;
 549                 cpu_set(i, covered);
 550         }
 551
 552         /* Do initialization in ACPI core */
 553         acpi_processor_preregister_performance(acpi_perf_data);
 554         return 0;
 555 }
 556
 557 #ifdef CONFIG_SMP
 558 /*
 559  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 560  * or do it in BIOS firmware and won't inform about it to OS. If not
 561  * detected, this has a side effect of making CPU run at a different speed
 562  * than OS intended it to run at. Detect it and handle it cleanly.
 563  */
 564 static int bios_with_sw_any_bug;
 565
 566 static int sw_any_bug_found(struct dmi_system_id *d)
 567 {
 568         bios_with_sw_any_bug = 1;
 569         return 0;
 570 }
 571
 572 #ifdef CONFIG_SMP
 573 static struct dmi_system_id sw_any_bug_dmi_table[] = {
 574         {
 575                 .callback = sw_any_bug_found,
 576                 .ident = "Supermicro Server X6DLP",
 577                 .matches = {
 578                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 579                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 580                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 581                 },
 582         },
 583         { }
 584 };
 585 #endif
 586
 587 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 588 {
 589         unsigned int i;
 590         unsigned int valid_states = 0;
 591         unsigned int cpu = policy->cpu;
 592         struct acpi_cpufreq_data *data;
 593         unsigned int result = 0;
 594         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
 595         struct acpi_processor_performance *perf;
 596
 597         dprintk("acpi_cpufreq_cpu_init\n");
 598
 599         if (!acpi_perf_data[cpu])
 600                 return -ENODEV;
 601
 602         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 603         if (!data)
 604                 return -ENOMEM;
 605
 606         data->acpi_data = acpi_perf_data[cpu];
 607         drv_data[cpu] = data;
 608
 609         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 610                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 611
 612         result = acpi_processor_register_performance(data->acpi_data, cpu);
 613         if (result)
 614                 goto err_free;
 615
 616         perf = data->acpi_data;
 617         policy->shared_type = perf->shared_type;
 618
 619         /*
 620          * Will let policy->cpus know about dependency only when software
 621          * coordination is required.
 622          */
 623         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 624             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 625                 policy->cpus = perf->shared_cpu_map;
 626         }
 627
 628 #ifdef CONFIG_SMP
 629         dmi_check_system(sw_any_bug_dmi_table);
 630         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 631                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 632                 policy->cpus = cpu_core_map[cpu];
 633         }
 634 #endif
 635
 636         /* capability check */
 637         if (perf->state_count <= 1) {
 638                 dprintk("No P-States\n");
 639                 result = -ENODEV;
 640                 goto err_unreg;
 641         }
 642
 643         if (perf->control_register.space_id != perf->status_register.space_id) {
 644                 result = -ENODEV;
 645                 goto err_unreg;
 646         }
 647
 648         switch (perf->control_register.space_id) {
 649         case ACPI_ADR_SPACE_SYSTEM_IO:
 650                 dprintk("SYSTEM IO addr space\n");
 651                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 652                 break;
 653         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 654                 dprintk("HARDWARE addr space\n");
 655                 if (!check_est_cpu(cpu)) {
 656                         result = -ENODEV;
 657                         goto err_unreg;
 658                 }
 659                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 660                 break;
 661         default:
 662                 dprintk("Unknown addr space %d\n",
 663                         (u32) (perf->control_register.space_id));
 664                 result = -ENODEV;
 665                 goto err_unreg;
 666         }
 667
 668         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 669                     (perf->state_count+1), GFP_KERNEL);
 670         if (!data->freq_table) {
 671                 result = -ENOMEM;
 672                 goto err_unreg;
 673         }
 674
 675         /* detect transition latency */
 676         policy->cpuinfo.transition_latency = 0;
 677         for (i=0; i<perf->state_count; i++) {
 678                 if ((perf->states[i].transition_latency * 1000) >
 679                     policy->cpuinfo.transition_latency)
 680                         policy->cpuinfo.transition_latency =
 681                             perf->states[i].transition_latency * 1000;
 682         }
 683         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 684
 685         data->max_freq = perf->states[0].core_frequency * 1000;
 686         /* table init */
 687         for (i=0; i<perf->state_count; i++) {
 688                 if (i>0 && perf->states[i].core_frequency ==
 689                     perf->states[i-1].core_frequency)
 690                         continue;
 691
 692                 data->freq_table[valid_states].index = i;
 693                 data->freq_table[valid_states].frequency =
 694                     perf->states[i].core_frequency * 1000;
 695                 valid_states++;
 696         }
 697         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 698
 699         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 700         if (result)
 701                 goto err_freqfree;
 702
 703         switch (data->cpu_feature) {
 704         case ACPI_ADR_SPACE_SYSTEM_IO:
 705                 /* Current speed is unknown and not detectable by IO port */
 706                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 707                 break;
 708         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 709                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 710                 get_cur_freq_on_cpu(cpu);
 711                 break;
 712         default:
 713                 break;
 714         }
 715
 716         /* notify BIOS that we exist */
 717         acpi_processor_notify_smm(THIS_MODULE);
 718
 719         /* Check for APERF/MPERF support in hardware */
 720         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
 721                 unsigned int ecx;
 722                 ecx = cpuid_ecx(6);
 723                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
 724                         acpi_cpufreq_driver.getavg = get_measured_perf;
 725         }
 726
 727         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 728         for (i = 0; i < perf->state_count; i++)
 729                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 730                         (i == perf->state ? '*' : ' '), i,
 731                         (u32) perf->states[i].core_frequency,
 732                         (u32) perf->states[i].power,
 733                         (u32) perf->states[i].transition_latency);
 734
 735         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 736
 737         /*
 738          * the first call to ->target() should result in us actually
 739          * writing something to the appropriate registers.
 740          */
 741         data->resume = 1;
 742
 743         return result;
 744
 745 err_freqfree:
 746         kfree(data->freq_table);
 747 err_unreg:
 748         acpi_processor_unregister_performance(perf, cpu);
 749 err_free:
 750         kfree(data);
 751         drv_data[cpu] = NULL;
 752
 753         return result;
 754 }
 755
 756 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 757 {
 758         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 759
 760         dprintk("acpi_cpufreq_cpu_exit\n");
 761
 762         if (data) {
 763                 cpufreq_frequency_table_put_attr(policy->cpu);
 764                 drv_data[policy->cpu] = NULL;
 765                 acpi_processor_unregister_performance(data->acpi_data,
 766                                                       policy->cpu);
 767                 kfree(data);
 768         }
 769
 770         return 0;
 771 }
 772
 773 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 774 {
 775         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 776
 777         dprintk("acpi_cpufreq_resume\n");
 778
 779         data->resume = 1;
 780
 781         return 0;
 782 }
 783
 784 static struct freq_attr *acpi_cpufreq_attr[] = {
 785         &cpufreq_freq_attr_scaling_available_freqs,
 786         NULL,
 787 };
 788
 789 static struct cpufreq_driver acpi_cpufreq_driver = {
 790         .verify = acpi_cpufreq_verify,
 791         .target = acpi_cpufreq_target,
 792         .init = acpi_cpufreq_cpu_init,
 793         .exit = acpi_cpufreq_cpu_exit,
 794         .resume = acpi_cpufreq_resume,
 795         .name = "acpi-cpufreq",
 796         .owner = THIS_MODULE,
 797         .attr = acpi_cpufreq_attr,
 798 };
 799
 800 static int __init acpi_cpufreq_init(void)
 801 {
 802         dprintk("acpi_cpufreq_init\n");
 803
 804         acpi_cpufreq_early_init();
 805
 806         return cpufreq_register_driver(&acpi_cpufreq_driver);
 807 }
 808
 809 static void __exit acpi_cpufreq_exit(void)
 810 {
 811         unsigned int i;
 812         dprintk("acpi_cpufreq_exit\n");
 813
 814         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 815
 816         for_each_possible_cpu(i) {
 817                 kfree(acpi_perf_data[i]);
 818                 acpi_perf_data[i] = NULL;
 819         }
 820         return;
 821 }
 822
 823 module_param(acpi_pstate_strict, uint, 0644);
 824 MODULE_PARM_DESC(acpi_pstate_strict,
 825         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 826         "performed during frequency changes.");
 827
 828 late_initcall(acpi_cpufreq_init);
 829 module_exit(acpi_cpufreq_exit);
 830
 831 MODULE_ALIAS("acpi");