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 struct msr_addr {
 130         u32 reg;
 131 };
 132
 133 struct io_addr {
 134         u16 port;
 135         u8 bit_width;
 136 };
 137
 138 typedef union {
 139         struct msr_addr msr;
 140         struct io_addr io;
 141 } drv_addr_union;
 142
 143 struct drv_cmd {
 144         unsigned int type;
 145         cpumask_t mask;
 146         drv_addr_union addr;
 147         u32 val;
 148 };
 149
 150 static void do_drv_read(struct drv_cmd *cmd)
 151 {
 152         u32 h;
 153
 154         switch (cmd->type) {
 155         case SYSTEM_INTEL_MSR_CAPABLE:
 156                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
 157                 break;
 158         case SYSTEM_IO_CAPABLE:
 159                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
 160                                 &cmd->val,
 161                                 (u32)cmd->addr.io.bit_width);
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167
 168 static void do_drv_write(struct drv_cmd *cmd)
 169 {
 170         u32 h = 0;
 171
 172         switch (cmd->type) {
 173         case SYSTEM_INTEL_MSR_CAPABLE:
 174                 wrmsr(cmd->addr.msr.reg, cmd->val, h);
 175                 break;
 176         case SYSTEM_IO_CAPABLE:
 177                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
 178                                 cmd->val,
 179                                 (u32)cmd->addr.io.bit_width);
 180                 break;
 181         default:
 182                 break;
 183         }
 184 }
 185
 186 static void drv_read(struct drv_cmd *cmd)
 187 {
 188         cpumask_t saved_mask = current->cpus_allowed;
 189         cmd->val = 0;
 190
 191         set_cpus_allowed(current, cmd->mask);
 192         do_drv_read(cmd);
 193         set_cpus_allowed(current, saved_mask);
 194 }
 195
 196 static void drv_write(struct drv_cmd *cmd)
 197 {
 198         cpumask_t saved_mask = current->cpus_allowed;
 199         unsigned int i;
 200
 201         for_each_cpu_mask(i, cmd->mask) {
 202                 set_cpus_allowed(current, cpumask_of_cpu(i));
 203                 do_drv_write(cmd);
 204         }
 205
 206         set_cpus_allowed(current, saved_mask);
 207         return;
 208 }
 209
 210 static u32 get_cur_val(cpumask_t mask)
 211 {
 212         struct acpi_processor_performance *perf;
 213         struct drv_cmd cmd;
 214
 215         if (unlikely(cpus_empty(mask)))
 216                 return 0;
 217
 218         switch (drv_data[first_cpu(mask)]->cpu_feature) {
 219         case SYSTEM_INTEL_MSR_CAPABLE:
 220                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 221                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
 222                 break;
 223         case SYSTEM_IO_CAPABLE:
 224                 cmd.type = SYSTEM_IO_CAPABLE;
 225                 perf = drv_data[first_cpu(mask)]->acpi_data;
 226                 cmd.addr.io.port = perf->control_register.address;
 227                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 228                 break;
 229         default:
 230                 return 0;
 231         }
 232
 233         cmd.mask = mask;
 234
 235         drv_read(&cmd);
 236
 237         dprintk("get_cur_val = %u\n", cmd.val);
 238
 239         return cmd.val;
 240 }
 241
 242 /*
 243  * Return the measured active (C0) frequency on this CPU since last call
 244  * to this function.
 245  * Input: cpu number
 246  * Return: Average CPU frequency in terms of max frequency (zero on error)
 247  *
 248  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 249  * over a period of time, while CPU is in C0 state.
 250  * IA32_MPERF counts at the rate of max advertised frequency
 251  * IA32_APERF counts at the rate of actual CPU frequency
 252  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 253  * no meaning should be associated with absolute values of these MSRs.
 254  */
 255 static unsigned int get_measured_perf(unsigned int cpu)
 256 {
 257         union {
 258                 struct {
 259                         u32 lo;
 260                         u32 hi;
 261                 } split;
 262                 u64 whole;
 263         } aperf_cur, mperf_cur;
 264
 265         cpumask_t saved_mask;
 266         unsigned int perf_percent;
 267         unsigned int retval;
 268
 269         saved_mask = current->cpus_allowed;
 270         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 271         if (get_cpu() != cpu) {
 272                 /* We were not able to run on requested processor */
 273                 put_cpu();
 274                 return 0;
 275         }
 276
 277         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
 278         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
 279
 280         wrmsr(MSR_IA32_APERF, 0,0);
 281         wrmsr(MSR_IA32_MPERF, 0,0);
 282
 283 #ifdef __i386__
 284         /*
 285          * We dont want to do 64 bit divide with 32 bit kernel
 286          * Get an approximate value. Return failure in case we cannot get
 287          * an approximate value.
 288          */
 289         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
 290                 int shift_count;
 291                 u32 h;
 292
 293                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
 294                 shift_count = fls(h);
 295
 296                 aperf_cur.whole >>= shift_count;
 297                 mperf_cur.whole >>= shift_count;
 298         }
 299
 300         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
 301                 int shift_count = 7;
 302                 aperf_cur.split.lo >>= shift_count;
 303                 mperf_cur.split.lo >>= shift_count;
 304         }
 305
 306         if (aperf_cur.split.lo && mperf_cur.split.lo)
 307                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
 308         else
 309                 perf_percent = 0;
 310
 311 #else
 312         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
 313                 int shift_count = 7;
 314                 aperf_cur.whole >>= shift_count;
 315                 mperf_cur.whole >>= shift_count;
 316         }
 317
 318         if (aperf_cur.whole && mperf_cur.whole)
 319                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
 320         else
 321                 perf_percent = 0;
 322
 323 #endif
 324
 325         retval = drv_data[cpu]->max_freq * perf_percent / 100;
 326
 327         put_cpu();
 328         set_cpus_allowed(current, saved_mask);
 329
 330         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
 331         return retval;
 332 }
 333
 334 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 335 {
 336         struct acpi_cpufreq_data *data = drv_data[cpu];
 337         unsigned int freq;
 338
 339         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
 340
 341         if (unlikely(data == NULL ||
 342                      data->acpi_data == NULL || data->freq_table == NULL)) {
 343                 return 0;
 344         }
 345
 346         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
 347         dprintk("cur freq = %u\n", freq);
 348
 349         return freq;
 350 }
 351
 352 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
 353                                 struct acpi_cpufreq_data *data)
 354 {
 355         unsigned int cur_freq;
 356         unsigned int i;
 357
 358         for (i=0; i<100; i++) {
 359                 cur_freq = extract_freq(get_cur_val(mask), data);
 360                 if (cur_freq == freq)
 361                         return 1;
 362                 udelay(10);
 363         }
 364         return 0;
 365 }
 366
 367 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 368                                unsigned int target_freq, unsigned int relation)
 369 {
 370         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 371         struct acpi_processor_performance *perf;
 372         struct cpufreq_freqs freqs;
 373         cpumask_t online_policy_cpus;
 374         struct drv_cmd cmd;
 375         unsigned int msr;
 376         unsigned int next_state = 0; /* Index into freq_table */
 377         unsigned int next_perf_state = 0; /* Index into perf table */
 378         unsigned int i;
 379         int result = 0;
 380
 381         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
 382
 383         if (unlikely(data == NULL ||
 384              data->acpi_data == NULL || data->freq_table == NULL)) {
 385                 return -ENODEV;
 386         }
 387
 388         perf = data->acpi_data;
 389         result = cpufreq_frequency_table_target(policy,
 390                                                 data->freq_table,
 391                                                 target_freq,
 392                                                 relation, &next_state);
 393         if (unlikely(result))
 394                 return -ENODEV;
 395
 396 #ifdef CONFIG_HOTPLUG_CPU
 397         /* cpufreq holds the hotplug lock, so we are safe from here on */
 398         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 399 #else
 400         online_policy_cpus = policy->cpus;
 401 #endif
 402
 403         next_perf_state = data->freq_table[next_state].index;
 404         if (perf->state == next_perf_state) {
 405                 if (unlikely(data->resume)) {
 406                         dprintk("Called after resume, resetting to P%d\n",
 407                                 next_perf_state);
 408                         data->resume = 0;
 409                 } else {
 410                         dprintk("Already at target state (P%d)\n",
 411                                 next_perf_state);
 412                         return 0;
 413                 }
 414         }
 415
 416         switch (data->cpu_feature) {
 417         case SYSTEM_INTEL_MSR_CAPABLE:
 418                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
 419                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
 420                 msr =
 421                     (u32) perf->states[next_perf_state].
 422                     control & INTEL_MSR_RANGE;
 423                 cmd.val = get_cur_val(online_policy_cpus);
 424                 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
 425                 break;
 426         case SYSTEM_IO_CAPABLE:
 427                 cmd.type = SYSTEM_IO_CAPABLE;
 428                 cmd.addr.io.port = perf->control_register.address;
 429                 cmd.addr.io.bit_width = perf->control_register.bit_width;
 430                 cmd.val = (u32) perf->states[next_perf_state].control;
 431                 break;
 432         default:
 433                 return -ENODEV;
 434         }
 435
 436         cpus_clear(cmd.mask);
 437
 438         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
 439                 cmd.mask = online_policy_cpus;
 440         else
 441                 cpu_set(policy->cpu, cmd.mask);
 442
 443         freqs.old = perf->states[perf->state].core_frequency * 1000;
 444         freqs.new = data->freq_table[next_state].frequency;
 445         for_each_cpu_mask(i, cmd.mask) {
 446                 freqs.cpu = i;
 447                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 448         }
 449
 450         drv_write(&cmd);
 451
 452         if (acpi_pstate_strict) {
 453                 if (!check_freqs(cmd.mask, freqs.new, data)) {
 454                         dprintk("acpi_cpufreq_target failed (%d)\n",
 455                                 policy->cpu);
 456                         return -EAGAIN;
 457                 }
 458         }
 459
 460         for_each_cpu_mask(i, cmd.mask) {
 461                 freqs.cpu = i;
 462                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 463         }
 464         perf->state = next_perf_state;
 465
 466         return result;
 467 }
 468
 469 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
 470 {
 471         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 472
 473         dprintk("acpi_cpufreq_verify\n");
 474
 475         return cpufreq_frequency_table_verify(policy, data->freq_table);
 476 }
 477
 478 static unsigned long
 479 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 480 {
 481         struct acpi_processor_performance *perf = data->acpi_data;
 482
 483         if (cpu_khz) {
 484                 /* search the closest match to cpu_khz */
 485                 unsigned int i;
 486                 unsigned long freq;
 487                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 488
 489                 for (i=0; i<(perf->state_count-1); i++) {
 490                         freq = freqn;
 491                         freqn = perf->states[i+1].core_frequency * 1000;
 492                         if ((2 * cpu_khz) > (freqn + freq)) {
 493                                 perf->state = i;
 494                                 return freq;
 495                         }
 496                 }
 497                 perf->state = perf->state_count-1;
 498                 return freqn;
 499         } else {
 500                 /* assume CPU is at P0... */
 501                 perf->state = 0;
 502                 return perf->states[0].core_frequency * 1000;
 503         }
 504 }
 505
 506 /*
 507  * acpi_cpufreq_early_init - initialize ACPI P-States library
 508  *
 509  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 510  * in order to determine correct frequency and voltage pairings. We can
 511  * do _PDC and _PSD and find out the processor dependency for the
 512  * actual init that will happen later...
 513  */
 514 static int acpi_cpufreq_early_init(void)
 515 {
 516         struct acpi_processor_performance *data;
 517         cpumask_t covered;
 518         unsigned int i, j;
 519
 520         dprintk("acpi_cpufreq_early_init\n");
 521
 522         for_each_possible_cpu(i) {
 523                 data = kzalloc(sizeof(struct acpi_processor_performance),
 524                                GFP_KERNEL);
 525                 if (!data) {
 526                         for_each_cpu_mask(j, covered) {
 527                                 kfree(acpi_perf_data[j]);
 528                                 acpi_perf_data[j] = NULL;
 529                         }
 530                         return -ENOMEM;
 531                 }
 532                 acpi_perf_data[i] = data;
 533                 cpu_set(i, covered);
 534         }
 535
 536         /* Do initialization in ACPI core */
 537         acpi_processor_preregister_performance(acpi_perf_data);
 538         return 0;
 539 }
 540
 541 #ifdef CONFIG_SMP
 542 /*
 543  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 544  * or do it in BIOS firmware and won't inform about it to OS. If not
 545  * detected, this has a side effect of making CPU run at a different speed
 546  * than OS intended it to run at. Detect it and handle it cleanly.
 547  */
 548 static int bios_with_sw_any_bug;
 549
 550 static int sw_any_bug_found(struct dmi_system_id *d)
 551 {
 552         bios_with_sw_any_bug = 1;
 553         return 0;
 554 }
 555
 556 static struct dmi_system_id sw_any_bug_dmi_table[] = {
 557         {
 558                 .callback = sw_any_bug_found,
 559                 .ident = "Supermicro Server X6DLP",
 560                 .matches = {
 561                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 562                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 563                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 564                 },
 565         },
 566         { }
 567 };
 568 #endif
 569
 570 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 571 {
 572         unsigned int i;
 573         unsigned int valid_states = 0;
 574         unsigned int cpu = policy->cpu;
 575         struct acpi_cpufreq_data *data;
 576         unsigned int result = 0;
 577         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
 578         struct acpi_processor_performance *perf;
 579
 580         dprintk("acpi_cpufreq_cpu_init\n");
 581
 582         if (!acpi_perf_data[cpu])
 583                 return -ENODEV;
 584
 585         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
 586         if (!data)
 587                 return -ENOMEM;
 588
 589         data->acpi_data = acpi_perf_data[cpu];
 590         drv_data[cpu] = data;
 591
 592         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 593                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 594
 595         result = acpi_processor_register_performance(data->acpi_data, cpu);
 596         if (result)
 597                 goto err_free;
 598
 599         perf = data->acpi_data;
 600         policy->shared_type = perf->shared_type;
 601
 602         /*
 603          * Will let policy->cpus know about dependency only when software
 604          * coordination is required.
 605          */
 606         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 607             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 608                 policy->cpus = perf->shared_cpu_map;
 609         }
 610
 611 #ifdef CONFIG_SMP
 612         dmi_check_system(sw_any_bug_dmi_table);
 613         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 614                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 615                 policy->cpus = cpu_core_map[cpu];
 616         }
 617 #endif
 618
 619         /* capability check */
 620         if (perf->state_count <= 1) {
 621                 dprintk("No P-States\n");
 622                 result = -ENODEV;
 623                 goto err_unreg;
 624         }
 625
 626         if (perf->control_register.space_id != perf->status_register.space_id) {
 627                 result = -ENODEV;
 628                 goto err_unreg;
 629         }
 630
 631         switch (perf->control_register.space_id) {
 632         case ACPI_ADR_SPACE_SYSTEM_IO:
 633                 dprintk("SYSTEM IO addr space\n");
 634                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 635                 break;
 636         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 637                 dprintk("HARDWARE addr space\n");
 638                 if (!check_est_cpu(cpu)) {
 639                         result = -ENODEV;
 640                         goto err_unreg;
 641                 }
 642                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 643                 break;
 644         default:
 645                 dprintk("Unknown addr space %d\n",
 646                         (u32) (perf->control_register.space_id));
 647                 result = -ENODEV;
 648                 goto err_unreg;
 649         }
 650
 651         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 652                     (perf->state_count+1), GFP_KERNEL);
 653         if (!data->freq_table) {
 654                 result = -ENOMEM;
 655                 goto err_unreg;
 656         }
 657
 658         /* detect transition latency */
 659         policy->cpuinfo.transition_latency = 0;
 660         for (i=0; i<perf->state_count; i++) {
 661                 if ((perf->states[i].transition_latency * 1000) >
 662                     policy->cpuinfo.transition_latency)
 663                         policy->cpuinfo.transition_latency =
 664                             perf->states[i].transition_latency * 1000;
 665         }
 666         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 667
 668         data->max_freq = perf->states[0].core_frequency * 1000;
 669         /* table init */
 670         for (i=0; i<perf->state_count; i++) {
 671                 if (i>0 && perf->states[i].core_frequency ==
 672                     perf->states[i-1].core_frequency)
 673                         continue;
 674
 675                 data->freq_table[valid_states].index = i;
 676                 data->freq_table[valid_states].frequency =
 677                     perf->states[i].core_frequency * 1000;
 678                 valid_states++;
 679         }
 680         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 681         perf->state = 0;
 682
 683         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 684         if (result)
 685                 goto err_freqfree;
 686
 687         switch (perf->control_register.space_id) {
 688         case ACPI_ADR_SPACE_SYSTEM_IO:
 689                 /* Current speed is unknown and not detectable by IO port */
 690                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 691                 break;
 692         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 693                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 694                 policy->cur = get_cur_freq_on_cpu(cpu);
 695                 break;
 696         default:
 697                 break;
 698         }
 699
 700         /* notify BIOS that we exist */
 701         acpi_processor_notify_smm(THIS_MODULE);
 702
 703         /* Check for APERF/MPERF support in hardware */
 704         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
 705                 unsigned int ecx;
 706                 ecx = cpuid_ecx(6);
 707                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
 708                         acpi_cpufreq_driver.getavg = get_measured_perf;
 709         }
 710
 711         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 712         for (i = 0; i < perf->state_count; i++)
 713                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 714                         (i == perf->state ? '*' : ' '), i,
 715                         (u32) perf->states[i].core_frequency,
 716                         (u32) perf->states[i].power,
 717                         (u32) perf->states[i].transition_latency);
 718
 719         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 720
 721         /*
 722          * the first call to ->target() should result in us actually
 723          * writing something to the appropriate registers.
 724          */
 725         data->resume = 1;
 726
 727         return result;
 728
 729 err_freqfree:
 730         kfree(data->freq_table);
 731 err_unreg:
 732         acpi_processor_unregister_performance(perf, cpu);
 733 err_free:
 734         kfree(data);
 735         drv_data[cpu] = NULL;
 736
 737         return result;
 738 }
 739
 740 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 741 {
 742         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 743
 744         dprintk("acpi_cpufreq_cpu_exit\n");
 745
 746         if (data) {
 747                 cpufreq_frequency_table_put_attr(policy->cpu);
 748                 drv_data[policy->cpu] = NULL;
 749                 acpi_processor_unregister_performance(data->acpi_data,
 750                                                       policy->cpu);
 751                 kfree(data);
 752         }
 753
 754         return 0;
 755 }
 756
 757 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 758 {
 759         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
 760
 761         dprintk("acpi_cpufreq_resume\n");
 762
 763         data->resume = 1;
 764
 765         return 0;
 766 }
 767
 768 static struct freq_attr *acpi_cpufreq_attr[] = {
 769         &cpufreq_freq_attr_scaling_available_freqs,
 770         NULL,
 771 };
 772
 773 static struct cpufreq_driver acpi_cpufreq_driver = {
 774         .verify = acpi_cpufreq_verify,
 775         .target = acpi_cpufreq_target,
 776         .init = acpi_cpufreq_cpu_init,
 777         .exit = acpi_cpufreq_cpu_exit,
 778         .resume = acpi_cpufreq_resume,
 779         .name = "acpi-cpufreq",
 780         .owner = THIS_MODULE,
 781         .attr = acpi_cpufreq_attr,
 782 };
 783
 784 static int __init acpi_cpufreq_init(void)
 785 {
 786         dprintk("acpi_cpufreq_init\n");
 787
 788         acpi_cpufreq_early_init();
 789
 790         return cpufreq_register_driver(&acpi_cpufreq_driver);
 791 }
 792
 793 static void __exit acpi_cpufreq_exit(void)
 794 {
 795         unsigned int i;
 796         dprintk("acpi_cpufreq_exit\n");
 797
 798         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 799
 800         for_each_possible_cpu(i) {
 801                 kfree(acpi_perf_data[i]);
 802                 acpi_perf_data[i] = NULL;
 803         }
 804         return;
 805 }
 806
 807 module_param(acpi_pstate_strict, uint, 0644);
 808 MODULE_PARM_DESC(acpi_pstate_strict,
 809         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 810         "performed during frequency changes.");
 811
 812 late_initcall(acpi_cpufreq_init);
 813 module_exit(acpi_cpufreq_exit);
 814
 815 MODULE_ALIAS("acpi");