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
 140 static void rdport(u16 port, u8 bit_width, u32 * ret)
 141 {
 142         *ret = 0;
 143         if (bit_width <= 8) {
 144                 *ret = inb(port);
 145         } else if (bit_width <= 16) {
 146                 *ret = inw(port);
 147         } else if (bit_width <= 32) {
 148                 *ret = inl(port);
 149         }
 150 }
 151
 152 struct msr_addr {
 153         u32 reg;
 154 };
 155
 156 struct io_addr {
 157         u16 port;
 158         u8 bit_width;
 159 };
 160
 161 typedef union {
 162         struct msr_addr msr;
 163         struct io_addr io;
 164 } drv_addr_union;
 165
 166 struct drv_cmd {
 167         unsigned int type;
 168         cpumask_t mask;
 169         drv_addr_union addr;
 170         u32 val;
 171 };
 172
 173 static void do_drv_read(struct drv_cmd *cmd)
 174 {
 175         u32 h;
 176
 177         switch (cmd->type) {
 178         case SYSTEM_INTEL_MSR_CAPABLE:
 179                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 180                 break;
 181         case SYSTEM_IO_CAPABLE:
 182                 rdport(cmd->addr.io.port, cmd->addr.io.bit_width, &cmd->val);
 183                 break;
 184         default:
 185                 break;
 186         }
 187 }
 188
 189 static void do_drv_write(struct drv_cmd *cmd)
 190 {
 191         u32 h = 0;
 192
 193         switch (cmd->type) {
 194         case SYSTEM_INTEL_MSR_CAPABLE:
 195                 wrmsr(cmd->addr.msr.reg, cmd->val, h);
 196                 break;
 197         case SYSTEM_IO_CAPABLE:
 198                 wrport(cmd->addr.io.port, cmd->addr.io.bit_width, cmd->val);
 199                 break;
 200         default:
 201                 break;
 202         }
 203 }
 204
 205 static inline void drv_read(struct drv_cmd *cmd)
 206 {
 207         cpumask_t saved_mask = current->cpus_allowed;
 208         cmd->val = 0;
 209
 210         set_cpus_allowed(current, cmd->mask);
 211         do_drv_read(cmd);
 212         set_cpus_allowed(current, saved_mask);
 213
 214 }
 215
 216 static void drv_write(struct drv_cmd *cmd)
 217 {
 218         cpumask_t saved_mask = current->cpus_allowed;
 219         unsigned int i;
 220
 221         for_each_cpu_mask(i, cmd->mask) {
 222                 set_cpus_allowed(current, cpumask_of_cpu(i));
 223                 do_drv_write(cmd);
 224         }
 225
 226         set_cpus_allowed(current, saved_mask);
 227         return;
 228 }
 229
 230 static u32 get_cur_val(cpumask_t mask)
 231 {
 232         struct acpi_processor_performance *perf;
 233         struct drv_cmd cmd;
 234
 235         if (unlikely(cpus_empty(mask)))
 236                 return 0;
 237
 238         switch (drv_data[first_cpu(mask)]->cpu_feature) {
 239         case SYSTEM_INTEL_MSR_CAPABLE:
 240                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 241                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 242                 break;
 243         case SYSTEM_IO_CAPABLE:
 244                 cmd.type = SYSTEM_IO_CAPABLE;
 245                 perf = drv_data[first_cpu(mask)]->acpi_data;
 246                 cmd.addr.io.port = perf->control_register.address;
 247                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 248                 break;
 249         default:
 250                 return 0;
 251         }
 252
 253         cmd.mask = mask;
 254
 255         drv_read(&cmd);
 256
 257         dprintk("get_cur_val = %u\n", cmd.val);
 258
 259         return cmd.val;
 260 }
 261
 262 /*
 263  * Return the measured active (C0) frequency on this CPU since last call
 264  * to this function.
 265  * Input: cpu number
 266  * Return: Average CPU frequency in terms of max frequency (zero on error)
 267  *
 268  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 269  * over a period of time, while CPU is in C0 state.
 270  * IA32_MPERF counts at the rate of max advertised frequency
 271  * IA32_APERF counts at the rate of actual CPU frequency
 272  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 273  * no meaning should be associated with absolute values of these MSRs.
 274  */
 275 static unsigned int get_measured_perf(unsigned int cpu)
 276 {
 277         union {
 278                 struct {
 279                         u32 lo;
 280                         u32 hi;
 281                 } split;
 282                 u64 whole;
 283         } aperf_cur, mperf_cur;
 284
 285         cpumask_t saved_mask;
 286         unsigned int perf_percent;
 287         unsigned int retval;
 288
 289         saved_mask = current->cpus_allowed;
 290         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 291         if (get_cpu() != cpu) {
 292                 /* We were not able to run on requested processor */
 293                 put_cpu();
 294                 return 0;
 295         }
 296
 297         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
 298         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
 299
 300         wrmsr(MSR_IA32_APERF, 0,0);
 301         wrmsr(MSR_IA32_MPERF, 0,0);
 302
 303 #ifdef __i386__
 304         /*
 305          * We dont want to do 64 bit divide with 32 bit kernel
 306          * Get an approximate value. Return failure in case we cannot get
 307          * an approximate value.
 308          */
 309         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
 310                 int shift_count;
 311                 u32 h;
 312
 313                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
 314                 shift_count = fls(h);
 315
 316                 aperf_cur.whole >>= shift_count;
 317                 mperf_cur.whole >>= shift_count;
 318         }
 319
 320         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
 321                 int shift_count = 7;
 322                 aperf_cur.split.lo >>= shift_count;
 323                 mperf_cur.split.lo >>= shift_count;
 324         }
 325
 326         if (aperf_cur.split.lo && mperf_cur.split.lo) {
 327                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
 328         } else {
 329                 perf_percent = 0;
 330         }
 331
 332 #else
 333         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
 334                 int shift_count = 7;
 335                 aperf_cur.whole >>= shift_count;
 336                 mperf_cur.whole >>= shift_count;
 337         }
 338
 339         if (aperf_cur.whole && mperf_cur.whole) {
 340                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
 341         } else {
 342                 perf_percent = 0;
 343         }
 344
 345 #endif
 346
 347         retval = drv_data[cpu]->max_freq * perf_percent / 100;
 348
 349         put_cpu();
 350         set_cpus_allowed(current, saved_mask);
 351
 352         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
 353         return retval;
 354 }
 355
 356 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 357 {
 358         struct acpi_cpufreq_data *data = drv_data[cpu];
 359         unsigned int freq;
 360
 361         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 362
 363         if (unlikely(data == NULL ||
 364                      data->acpi_data == NULL || data->freq_table == NULL)) {
 365                 return 0;
 366         }
 367
 368         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
 369         dprintk("cur freq = %u\n", freq);
 370
 371         return freq;
 372 }
 373
 374 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
 375                                 struct acpi_cpufreq_data *data)
 376 {
 377         unsigned int cur_freq;
 378         unsigned int i;
 379
 380         for (i = 0; i < 100; i++) {
 381                 cur_freq = extract_freq(get_cur_val(mask), data);
 382                 if (cur_freq == freq)
 383                         return 1;
 384                 udelay(10);
 385         }
 386         return 0;
 387 }
 388
 389 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 390                                unsigned int target_freq, unsigned int relation)
 391 {
 392         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 393         struct acpi_processor_performance *perf;
 394         struct cpufreq_freqs freqs;
 395         cpumask_t online_policy_cpus;
 396         struct drv_cmd cmd;
 397         unsigned int msr;
 398         unsigned int next_state = 0;
 399         unsigned int next_perf_state = 0;
 400         unsigned int i;
 401         int result = 0;
 402
 403         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 404
 405         if (unlikely(data == NULL ||
 406                      data->acpi_data == NULL || data->freq_table == NULL)) {
 407                 return -ENODEV;
 408         }
 409
 410         perf = data->acpi_data;
 411         result = cpufreq_frequency_table_target(policy,
 412                                                 data->freq_table,
 413                                                 target_freq,
 414                                                 relation, &next_state);
 415         if (unlikely(result))
 416                 return -ENODEV;
 417
 418 #ifdef CONFIG_HOTPLUG_CPU
 419         /* cpufreq holds the hotplug lock, so we are safe from here on */
 420         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 421 #else
 422         online_policy_cpus = policy->cpus;
 423 #endif
 424
 425         next_perf_state = data->freq_table[next_state].index;
 426         if (perf->state == next_perf_state) {
 427                 if (unlikely(data->resume)) {
 428                         dprintk("Called after resume, resetting to P%d\n",
 429                                 next_perf_state);
 430                         data->resume = 0;
 431                 } else {
 432                         dprintk("Already at target state (P%d)\n",
 433                                 next_perf_state);
 434                         return 0;
 435                 }
 436         }
 437
 438         switch (data->cpu_feature) {
 439         case SYSTEM_INTEL_MSR_CAPABLE:
 440                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 441                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 442                 msr =
 443                     (u32) perf->states[next_perf_state].
 444                     control & INTEL_MSR_RANGE;
 445                 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 446                 break;
 447         case SYSTEM_IO_CAPABLE:
 448                 cmd.type = SYSTEM_IO_CAPABLE;
 449                 cmd.addr.io.port = perf->control_register.address;
 450                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 451                 cmd.val = (u32) perf->states[next_perf_state].control;
 452                 break;
 453         default:
 454                 return -ENODEV;
 455         }
 456
 457         cpus_clear(cmd.mask);
 458
 459         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 460                 cmd.mask = online_policy_cpus;
 461         else
 462                 cpu_set(policy->cpu, cmd.mask);
 463
 464         freqs.old = data->freq_table[perf->state].frequency;
 465         freqs.new = data->freq_table[next_perf_state].frequency;
 466         for_each_cpu_mask(i, cmd.mask) {
 467                 freqs.cpu = i;
 468                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 469         }
 470
 471         drv_write(&cmd);
 472
 473         if (acpi_pstate_strict) {
 474                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 475                         dprintk("acpi_cpufreq_target failed (%d)\n",
 476                                 policy->cpu);
 477                         return -EAGAIN;
 478                 }
 479         }
 480
 481         for_each_cpu_mask(i, cmd.mask) {
 482                 freqs.cpu = i;
 483                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 484         }
 485         perf->state = next_perf_state;
 486
 487         return result;
 488 }
 489
 490 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 491 {
 492         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 493
 494         dprintk("acpi_cpufreq_verify\n");
 495
 496         return cpufreq_frequency_table_verify(policy, data->freq_table);
 497 }
 498
 499 static unsigned long
 500 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 501 {
 502         struct acpi_processor_performance *perf = data->acpi_data;
 503
 504         if (cpu_khz) {
 505                 /* search the closest match to cpu_khz */
 506                 unsigned int i;
 507                 unsigned long freq;
 508                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 509
 510                 for (i = 0; i < (perf->state_count - 1); i++) {
 511                         freq = freqn;
 512                         freqn = perf->states[i + 1].core_frequency * 1000;
 513                         if ((2 * cpu_khz) > (freqn + freq)) {
 514                                 perf->state = i;
 515                                 return freq;
 516                         }
 517                 }
 518                 perf->state = perf->state_count - 1;
 519                 return freqn;
 520         } else {
 521                 /* assume CPU is at P0... */
 522                 perf->state = 0;
 523                 return perf->states[0].core_frequency * 1000;
 524         }
 525 }
 526
 527 /*
 528  * acpi_cpufreq_early_init - initialize ACPI P-States library
 529  *
 530  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 531  * in order to determine correct frequency and voltage pairings. We can
 532  * do _PDC and _PSD and find out the processor dependency for the
 533  * actual init that will happen later...
 534  */
 535 static int acpi_cpufreq_early_init(void)
 536 {
 537         struct acpi_processor_performance *data;
 538         cpumask_t covered;
 539         unsigned int i, j;
 540
 541         dprintk("acpi_cpufreq_early_init\n");
 542
 543         for_each_possible_cpu(i) {
 544                 data = kzalloc(sizeof(struct acpi_processor_performance),
 545                                GFP_KERNEL);
 546                 if (!data) {
 547                         for_each_cpu_mask(j, covered) {
 548                                 kfree(acpi_perf_data[j]);
 549                                 acpi_perf_data[j] = NULL;
 550                         }
 551                         return -ENOMEM;
 552                 }
 553                 acpi_perf_data[i] = data;
 554                 cpu_set(i, covered);
 555         }
 556
 557         /* Do initialization in ACPI core */
 558         acpi_processor_preregister_performance(acpi_perf_data);
 559         return 0;
 560 }
 561
 562 /*
 563  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 564  * or do it in BIOS firmware and won't inform about it to OS. If not
 565  * detected, this has a side effect of making CPU run at a different speed
 566  * than OS intended it to run at. Detect it and handle it cleanly.
 567  */
 568 static int bios_with_sw_any_bug;
 569
 570 static int sw_any_bug_found(struct dmi_system_id *d)
 571 {
 572         bios_with_sw_any_bug = 1;
 573         return 0;
 574 }
 575
 576 static struct dmi_system_id sw_any_bug_dmi_table[] = {
 577         {
 578                 .callback = sw_any_bug_found,
 579                 .ident = "Supermicro Server X6DLP",
 580                 .matches = {
 581                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 582                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 583                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 584                 },
 585         },
 586         { }
 587 };
 588
 589 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 590 {
 591         unsigned int i;
 592         unsigned int valid_states = 0;
 593         unsigned int cpu = policy->cpu;
 594         struct acpi_cpufreq_data *data;
 595         unsigned int result = 0;
 596         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
 597         struct acpi_processor_performance *perf;
 598
 599         dprintk("acpi_cpufreq_cpu_init\n");
 600
 601         if (!acpi_perf_data[cpu])
 602                 return -ENODEV;
 603
 604         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 605         if (!data)
 606                 return -ENOMEM;
 607
 608         data->acpi_data = acpi_perf_data[cpu];
 609         drv_data[cpu] = data;
 610
 611         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
 612                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 613         }
 614
 615         result = acpi_processor_register_performance(data->acpi_data, cpu);
 616         if (result)
 617                 goto err_free;
 618
 619         perf = data->acpi_data;
 620         policy->shared_type = perf->shared_type;
 621         /*
 622          * Will let policy->cpus know about dependency only when software
 623          * coordination is required.
 624          */
 625         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 626             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 627                 policy->cpus = perf->shared_cpu_map;
 628         }
 629
 630 #ifdef CONFIG_SMP
 631         dmi_check_system(sw_any_bug_dmi_table);
 632         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 633                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 634                 policy->cpus = cpu_core_map[cpu];
 635         }
 636 #endif
 637
 638         /* capability check */
 639         if (perf->state_count <= 1) {
 640                 dprintk("No P-States\n");
 641                 result = -ENODEV;
 642                 goto err_unreg;
 643         }
 644
 645         if (perf->control_register.space_id != perf->status_register.space_id) {
 646                 result = -ENODEV;
 647                 goto err_unreg;
 648         }
 649
 650         switch (perf->control_register.space_id) {
 651         case ACPI_ADR_SPACE_SYSTEM_IO:
 652                 dprintk("SYSTEM IO addr space\n");
 653                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 654                 break;
 655         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 656                 dprintk("HARDWARE addr space\n");
 657                 if (!check_est_cpu(cpu)) {
 658                         result = -ENODEV;
 659                         goto err_unreg;
 660                 }
 661                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 662                 break;
 663         default:
 664                 dprintk("Unknown addr space %d\n",
 665                         (u32) (perf->control_register.space_id));
 666                 result = -ENODEV;
 667                 goto err_unreg;
 668         }
 669
 670         data->freq_table =
 671             kmalloc(sizeof(struct cpufreq_frequency_table) *
 672                     (perf->state_count + 1), GFP_KERNEL);
 673         if (!data->freq_table) {
 674                 result = -ENOMEM;
 675                 goto err_unreg;
 676         }
 677
 678         /* detect transition latency */
 679         policy->cpuinfo.transition_latency = 0;
 680         for (i = 0; i < perf->state_count; i++) {
 681                 if ((perf->states[i].transition_latency * 1000) >
 682                     policy->cpuinfo.transition_latency)
 683                         policy->cpuinfo.transition_latency =
 684                             perf->states[i].transition_latency * 1000;
 685         }
 686         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 687
 688         data->max_freq = perf->states[0].core_frequency * 1000;
 689         /* table init */
 690         for (i = 0; i < perf->state_count; i++) {
 691                 if (i > 0 && perf->states[i].core_frequency ==
 692                     perf->states[i - 1].core_frequency)
 693                         continue;
 694
 695                 data->freq_table[valid_states].index = i;
 696                 data->freq_table[valid_states].frequency =
 697                     perf->states[i].core_frequency * 1000;
 698                 valid_states++;
 699         }
 700         data->freq_table[perf->state_count].frequency = CPUFREQ_TABLE_END;
 701
 702         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 703         if (result) {
 704                 goto err_freqfree;
 705         }
 706
 707         switch (data->cpu_feature) {
 708         case ACPI_ADR_SPACE_SYSTEM_IO:
 709                 /* Current speed is unknown and not detectable by IO port */
 710                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 711                 break;
 712         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 713                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 714                 get_cur_freq_on_cpu(cpu);
 715                 break;
 716         default:
 717                 break;
 718         }
 719
 720         /* notify BIOS that we exist */
 721         acpi_processor_notify_smm(THIS_MODULE);
 722
 723         /* Check for APERF/MPERF support in hardware */
 724         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
 725                 unsigned int ecx;
 726                 ecx = cpuid_ecx(6);
 727                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY) {
 728                         acpi_cpufreq_driver.getavg = get_measured_perf;
 729                 }
 730         }
 731
 732         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 733         for (i = 0; i < perf->state_count; i++)
 734                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 735                         (i == perf->state ? '*' : ' '), i,
 736                         (u32) perf->states[i].core_frequency,
 737                         (u32) perf->states[i].power,
 738                         (u32) perf->states[i].transition_latency);
 739
 740         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 741
 742         /*
 743          * the first call to ->target() should result in us actually
 744          * writing something to the appropriate registers.
 745          */
 746         data->resume = 1;
 747
 748         return result;
 749
 750       err_freqfree:
 751         kfree(data->freq_table);
 752       err_unreg:
 753         acpi_processor_unregister_performance(perf, cpu);
 754       err_free:
 755         kfree(data);
 756         drv_data[cpu] = NULL;
 757
 758         return result;
 759 }
 760
 761 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 762 {
 763         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 764
 765         dprintk("acpi_cpufreq_cpu_exit\n");
 766
 767         if (data) {
 768                 cpufreq_frequency_table_put_attr(policy->cpu);
 769                 drv_data[policy->cpu] = NULL;
 770                 acpi_processor_unregister_performance(data->acpi_data,
 771                                                       policy->cpu);
 772                 kfree(data);
 773         }
 774
 775         return 0;
 776 }
 777
 778 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 779 {
 780         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 781
 782         dprintk("acpi_cpufreq_resume\n");
 783
 784         data->resume = 1;
 785
 786         return 0;
 787 }
 788
 789 static struct freq_attr *acpi_cpufreq_attr[] = {
 790         &cpufreq_freq_attr_scaling_available_freqs,
 791         NULL,
 792 };
 793
 794 static struct cpufreq_driver acpi_cpufreq_driver = {
 795         .verify = acpi_cpufreq_verify,
 796         .target = acpi_cpufreq_target,
 797         .init = acpi_cpufreq_cpu_init,
 798         .exit = acpi_cpufreq_cpu_exit,
 799         .resume = acpi_cpufreq_resume,
 800         .name = "acpi-cpufreq",
 801         .owner = THIS_MODULE,
 802         .attr = acpi_cpufreq_attr,
 803 };
 804
 805 static int __init acpi_cpufreq_init(void)
 806 {
 807         dprintk("acpi_cpufreq_init\n");
 808
 809         acpi_cpufreq_early_init();
 810
 811         return cpufreq_register_driver(&acpi_cpufreq_driver);
 812 }
 813
 814 static void __exit acpi_cpufreq_exit(void)
 815 {
 816         unsigned int i;
 817         dprintk("acpi_cpufreq_exit\n");
 818
 819         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 820
 821         for_each_possible_cpu(i) {
 822                 kfree(acpi_perf_data[i]);
 823                 acpi_perf_data[i] = NULL;
 824         }
 825         return;
 826 }
 827
 828 module_param(acpi_pstate_strict, uint, 0644);
 829 MODULE_PARM_DESC(acpi_pstate_strict,
 830                  "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
 831
 832 late_initcall(acpi_cpufreq_init);
 833 module_exit(acpi_cpufreq_exit);
 834
 835 MODULE_ALIAS("acpi");