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