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

   1 /*
   2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
   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  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/cpufreq.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/seq_file.h>
  33 #include <linux/compiler.h>
  34 #include <linux/sched.h>        /* current */
  35 #include <linux/dmi.h>
  36 #include <asm/io.h>
  37 #include <asm/delay.h>
  38 #include <asm/uaccess.h>
  39
  40 #include <linux/acpi.h>
  41 #include <acpi/processor.h>
  42
  43 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
  44
  45 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  46 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  47 MODULE_LICENSE("GPL");
  48
  49
  50 struct cpufreq_acpi_io {
  51         struct acpi_processor_performance       *acpi_data;
  52         struct cpufreq_frequency_table          *freq_table;
  53         unsigned int                            resume;
  54 };
  55
  56 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
  57 static struct acpi_processor_performance        *acpi_perf_data[NR_CPUS];
  58
  59 static struct cpufreq_driver acpi_cpufreq_driver;
  60
  61 static unsigned int acpi_pstate_strict;
  62
  63 static int
  64 acpi_processor_write_port(
  65         u16     port,
  66         u8      bit_width,
  67         u32     value)
  68 {
  69         if (bit_width <= 8) {
  70                 outb(value, port);
  71         } else if (bit_width <= 16) {
  72                 outw(value, port);
  73         } else if (bit_width <= 32) {
  74                 outl(value, port);
  75         } else {
  76                 return -ENODEV;
  77         }
  78         return 0;
  79 }
  80
  81 static int
  82 acpi_processor_read_port(
  83         u16     port,
  84         u8      bit_width,
  85         u32     *ret)
  86 {
  87         *ret = 0;
  88         if (bit_width <= 8) {
  89                 *ret = inb(port);
  90         } else if (bit_width <= 16) {
  91                 *ret = inw(port);
  92         } else if (bit_width <= 32) {
  93                 *ret = inl(port);
  94         } else {
  95                 return -ENODEV;
  96         }
  97         return 0;
  98 }
  99
 100 static int
 101 acpi_processor_set_performance (
 102         struct cpufreq_acpi_io  *data,
 103         unsigned int            cpu,
 104         int                     state)
 105 {
 106         u16                     port = 0;
 107         u8                      bit_width = 0;
 108         int                     i = 0;
 109         int                     ret = 0;
 110         u32                     value = 0;
 111         int                     retval;
 112         struct acpi_processor_performance       *perf;
 113
 114         dprintk("acpi_processor_set_performance\n");
 115
 116         retval = 0;
 117         perf = data->acpi_data;
 118         if (state == perf->state) {
 119                 if (unlikely(data->resume)) {
 120                         dprintk("Called after resume, resetting to P%d\n", state);
 121                         data->resume = 0;
 122                 } else {
 123                         dprintk("Already at target state (P%d)\n", state);
 124                         return (retval);
 125                 }
 126         }
 127
 128         dprintk("Transitioning from P%d to P%d\n", perf->state, state);
 129
 130         /*
 131          * First we write the target state's 'control' value to the
 132          * control_register.
 133          */
 134
 135         port = perf->control_register.address;
 136         bit_width = perf->control_register.bit_width;
 137         value = (u32) perf->states[state].control;
 138
 139         dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
 140
 141         ret = acpi_processor_write_port(port, bit_width, value);
 142         if (ret) {
 143                 dprintk("Invalid port width 0x%04x\n", bit_width);
 144                 return (ret);
 145         }
 146
 147         /*
 148          * Assume the write went through when acpi_pstate_strict is not used.
 149          * As read status_register is an expensive operation and there
 150          * are no specific error cases where an IO port write will fail.
 151          */
 152         if (acpi_pstate_strict) {
 153                 /* Then we read the 'status_register' and compare the value
 154                  * with the target state's 'status' to make sure the
 155                  * transition was successful.
 156                  * Note that we'll poll for up to 1ms (100 cycles of 10us)
 157                  * before giving up.
 158                  */
 159
 160                 port = perf->status_register.address;
 161                 bit_width = perf->status_register.bit_width;
 162
 163                 dprintk("Looking for 0x%08x from port 0x%04x\n",
 164                         (u32) perf->states[state].status, port);
 165
 166                 for (i = 0; i < 100; i++) {
 167                         ret = acpi_processor_read_port(port, bit_width, &value);
 168                         if (ret) {
 169                                 dprintk("Invalid port width 0x%04x\n", bit_width);
 170                                 return (ret);
 171                         }
 172                         if (value == (u32) perf->states[state].status)
 173                                 break;
 174                         udelay(10);
 175                 }
 176         } else {
 177                 value = (u32) perf->states[state].status;
 178         }
 179
 180         if (unlikely(value != (u32) perf->states[state].status)) {
 181                 printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
 182                 retval = -ENODEV;
 183                 return (retval);
 184         }
 185
 186         dprintk("Transition successful after %d microseconds\n", i * 10);
 187
 188         perf->state = state;
 189         return (retval);
 190 }
 191
 192
 193 static int
 194 acpi_cpufreq_target (
 195         struct cpufreq_policy   *policy,
 196         unsigned int target_freq,
 197         unsigned int relation)
 198 {
 199         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 200         struct cpufreq_acpi_io *cpudata;
 201         struct acpi_processor_performance *perf;
 202         struct cpufreq_freqs freqs;
 203         cpumask_t online_policy_cpus;
 204         cpumask_t saved_mask;
 205         cpumask_t set_mask;
 206         cpumask_t covered_cpus;
 207         unsigned int cur_state = 0;
 208         unsigned int next_state = 0;
 209         unsigned int result = 0;
 210         unsigned int j;
 211         unsigned int tmp;
 212
 213         dprintk("acpi_cpufreq_setpolicy\n");
 214
 215         result = cpufreq_frequency_table_target(policy,
 216                         data->freq_table,
 217                         target_freq,
 218                         relation,
 219                         &next_state);
 220         if (unlikely(result))
 221                 return (result);
 222
 223         perf = data->acpi_data;
 224         cur_state = perf->state;
 225         freqs.old = data->freq_table[cur_state].frequency;
 226         freqs.new = data->freq_table[next_state].frequency;
 227
 228 #ifdef CONFIG_HOTPLUG_CPU
 229         /* cpufreq holds the hotplug lock, so we are safe from here on */
 230         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 231 #else
 232         online_policy_cpus = policy->cpus;
 233 #endif
 234
 235         for_each_cpu_mask(j, online_policy_cpus) {
 236                 freqs.cpu = j;
 237                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 238         }
 239
 240         /*
 241          * We need to call driver->target() on all or any CPU in
 242          * policy->cpus, depending on policy->shared_type.
 243          */
 244         saved_mask = current->cpus_allowed;
 245         cpus_clear(covered_cpus);
 246         for_each_cpu_mask(j, online_policy_cpus) {
 247                 /*
 248                  * Support for SMP systems.
 249                  * Make sure we are running on CPU that wants to change freq
 250                  */
 251                 cpus_clear(set_mask);
 252                 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
 253                         cpus_or(set_mask, set_mask, online_policy_cpus);
 254                 else
 255                         cpu_set(j, set_mask);
 256
 257                 set_cpus_allowed(current, set_mask);
 258                 if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
 259                         dprintk("couldn't limit to CPUs in this domain\n");
 260                         result = -EAGAIN;
 261                         break;
 262                 }
 263
 264                 cpudata = acpi_io_data[j];
 265                 result = acpi_processor_set_performance(cpudata, j, next_state);
 266                 if (result) {
 267                         result = -EAGAIN;
 268                         break;
 269                 }
 270
 271                 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
 272                         break;
 273
 274                 cpu_set(j, covered_cpus);
 275         }
 276
 277         for_each_cpu_mask(j, online_policy_cpus) {
 278                 freqs.cpu = j;
 279                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 280         }
 281
 282         if (unlikely(result)) {
 283                 /*
 284                  * We have failed halfway through the frequency change.
 285                  * We have sent callbacks to online_policy_cpus and
 286                  * acpi_processor_set_performance() has been called on
 287                  * coverd_cpus. Best effort undo..
 288                  */
 289
 290                 if (!cpus_empty(covered_cpus)) {
 291                         for_each_cpu_mask(j, covered_cpus) {
 292                                 cpus_clear(set_mask);
 293                                 cpu_set(j, set_mask);
 294                                 set_cpus_allowed(current, set_mask);
 295                                 cpudata = acpi_io_data[j];
 296                                 acpi_processor_set_performance(cpudata,
 297                                                 j,
 298                                                 cur_state);
 299                         }
 300                 }
 301
 302                 tmp = freqs.new;
 303                 freqs.new = freqs.old;
 304                 freqs.old = tmp;
 305                 for_each_cpu_mask(j, online_policy_cpus) {
 306                         freqs.cpu = j;
 307                         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 308                         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 309                 }
 310         }
 311
 312         set_cpus_allowed(current, saved_mask);
 313         return (result);
 314 }
 315
 316
 317 static int
 318 acpi_cpufreq_verify (
 319         struct cpufreq_policy   *policy)
 320 {
 321         unsigned int result = 0;
 322         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 323
 324         dprintk("acpi_cpufreq_verify\n");
 325
 326         result = cpufreq_frequency_table_verify(policy,
 327                         data->freq_table);
 328
 329         return (result);
 330 }
 331
 332
 333 static unsigned long
 334 acpi_cpufreq_guess_freq (
 335         struct cpufreq_acpi_io  *data,
 336         unsigned int            cpu)
 337 {
 338         struct acpi_processor_performance       *perf = data->acpi_data;
 339
 340         if (cpu_khz) {
 341                 /* search the closest match to cpu_khz */
 342                 unsigned int i;
 343                 unsigned long freq;
 344                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 345
 346                 for (i = 0; i < (perf->state_count - 1); i++) {
 347                         freq = freqn;
 348                         freqn = perf->states[i+1].core_frequency * 1000;
 349                         if ((2 * cpu_khz) > (freqn + freq)) {
 350                                 perf->state = i;
 351                                 return (freq);
 352                         }
 353                 }
 354                 perf->state = perf->state_count - 1;
 355                 return (freqn);
 356         } else {
 357                 /* assume CPU is at P0... */
 358                 perf->state = 0;
 359                 return perf->states[0].core_frequency * 1000;
 360         }
 361 }
 362
 363
 364 /*
 365  * acpi_cpufreq_early_init - initialize ACPI P-States library
 366  *
 367  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 368  * in order to determine correct frequency and voltage pairings. We can
 369  * do _PDC and _PSD and find out the processor dependency for the
 370  * actual init that will happen later...
 371  */
 372 static int acpi_cpufreq_early_init_acpi(void)
 373 {
 374         struct acpi_processor_performance       *data;
 375         unsigned int                            i, j;
 376
 377         dprintk("acpi_cpufreq_early_init\n");
 378
 379         for_each_possible_cpu(i) {
 380                 data = kzalloc(sizeof(struct acpi_processor_performance),
 381                         GFP_KERNEL);
 382                 if (!data) {
 383                         for_each_possible_cpu(j) {
 384                                 kfree(acpi_perf_data[j]);
 385                                 acpi_perf_data[j] = NULL;
 386                         }
 387                         return (-ENOMEM);
 388                 }
 389                 acpi_perf_data[i] = data;
 390         }
 391
 392         /* Do initialization in ACPI core */
 393         return acpi_processor_preregister_performance(acpi_perf_data);
 394 }
 395
 396 /*
 397  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 398  * or do it in BIOS firmware and won't inform about it to OS. If not
 399  * detected, this has a side effect of making CPU run at a different speed
 400  * than OS intended it to run at. Detect it and handle it cleanly.
 401  */
 402 static int bios_with_sw_any_bug;
 403
 404 static int sw_any_bug_found(struct dmi_system_id *d)
 405 {
 406         bios_with_sw_any_bug = 1;
 407         return 0;
 408 }
 409
 410 static struct dmi_system_id sw_any_bug_dmi_table[] = {
 411         {
 412                 .callback = sw_any_bug_found,
 413                 .ident = "Supermicro Server X6DLP",
 414                 .matches = {
 415                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 416                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 417                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 418                 },
 419         },
 420         { }
 421 };
 422
 423 static int
 424 acpi_cpufreq_cpu_init (
 425         struct cpufreq_policy   *policy)
 426 {
 427         unsigned int            i;
 428         unsigned int            cpu = policy->cpu;
 429         struct cpufreq_acpi_io  *data;
 430         unsigned int            result = 0;
 431         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
 432         struct acpi_processor_performance       *perf;
 433
 434         dprintk("acpi_cpufreq_cpu_init\n");
 435
 436         if (!acpi_perf_data[cpu])
 437                 return (-ENODEV);
 438
 439         data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 440         if (!data)
 441                 return (-ENOMEM);
 442
 443         data->acpi_data = acpi_perf_data[cpu];
 444         acpi_io_data[cpu] = data;
 445
 446         result = acpi_processor_register_performance(data->acpi_data, cpu);
 447
 448         if (result)
 449                 goto err_free;
 450
 451         perf = data->acpi_data;
 452         policy->shared_type = perf->shared_type;
 453         /*
 454          * Will let policy->cpus know about dependency only when software
 455          * coordination is required.
 456          */
 457         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 458             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 459                 policy->cpus = perf->shared_cpu_map;
 460         }
 461
 462 #ifdef CONFIG_SMP
 463         dmi_check_system(sw_any_bug_dmi_table);
 464         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 465                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 466                 policy->cpus = cpu_core_map[cpu];
 467         }
 468 #endif
 469
 470         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
 471                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 472         }
 473
 474         /* capability check */
 475         if (perf->state_count <= 1) {
 476                 dprintk("No P-States\n");
 477                 result = -ENODEV;
 478                 goto err_unreg;
 479         }
 480
 481         if ((perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
 482             (perf->status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
 483                 dprintk("Unsupported address space [%d, %d]\n",
 484                         (u32) (perf->control_register.space_id),
 485                         (u32) (perf->status_register.space_id));
 486                 result = -ENODEV;
 487                 goto err_unreg;
 488         }
 489
 490         /* alloc freq_table */
 491         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (perf->state_count + 1), GFP_KERNEL);
 492         if (!data->freq_table) {
 493                 result = -ENOMEM;
 494                 goto err_unreg;
 495         }
 496
 497         /* detect transition latency */
 498         policy->cpuinfo.transition_latency = 0;
 499         for (i=0; i<perf->state_count; i++) {
 500                 if ((perf->states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
 501                         policy->cpuinfo.transition_latency = perf->states[i].transition_latency * 1000;
 502         }
 503         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 504
 505         /* The current speed is unknown and not detectable by ACPI...  */
 506         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 507
 508         /* table init */
 509         for (i=0; i<=perf->state_count; i++)
 510         {
 511                 data->freq_table[i].index = i;
 512                 if (i<perf->state_count)
 513                         data->freq_table[i].frequency = perf->states[i].core_frequency * 1000;
 514                 else
 515                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
 516         }
 517
 518         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 519         if (result) {
 520                 goto err_freqfree;
 521         }
 522
 523         /* notify BIOS that we exist */
 524         acpi_processor_notify_smm(THIS_MODULE);
 525
 526         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
 527                cpu);
 528         for (i = 0; i < perf->state_count; i++)
 529                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 530                         (i == perf->state?'*':' '), i,
 531                         (u32) perf->states[i].core_frequency,
 532                         (u32) perf->states[i].power,
 533                         (u32) perf->states[i].transition_latency);
 534
 535         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 536
 537         /*
 538          * the first call to ->target() should result in us actually
 539          * writing something to the appropriate registers.
 540          */
 541         data->resume = 1;
 542
 543         return (result);
 544
 545  err_freqfree:
 546         kfree(data->freq_table);
 547  err_unreg:
 548         acpi_processor_unregister_performance(perf, cpu);
 549  err_free:
 550         kfree(data);
 551         acpi_io_data[cpu] = NULL;
 552
 553         return (result);
 554 }
 555
 556
 557 static int
 558 acpi_cpufreq_cpu_exit (
 559         struct cpufreq_policy   *policy)
 560 {
 561         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 562
 563
 564         dprintk("acpi_cpufreq_cpu_exit\n");
 565
 566         if (data) {
 567                 cpufreq_frequency_table_put_attr(policy->cpu);
 568                 acpi_io_data[policy->cpu] = NULL;
 569                 acpi_processor_unregister_performance(data->acpi_data, policy->cpu);
 570                 kfree(data);
 571         }
 572
 573         return (0);
 574 }
 575
 576 static int
 577 acpi_cpufreq_resume (
 578         struct cpufreq_policy   *policy)
 579 {
 580         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 581
 582
 583         dprintk("acpi_cpufreq_resume\n");
 584
 585         data->resume = 1;
 586
 587         return (0);
 588 }
 589
 590
 591 static struct freq_attr* acpi_cpufreq_attr[] = {
 592         &cpufreq_freq_attr_scaling_available_freqs,
 593         NULL,
 594 };
 595
 596 static struct cpufreq_driver acpi_cpufreq_driver = {
 597         .verify = acpi_cpufreq_verify,
 598         .target = acpi_cpufreq_target,
 599         .init   = acpi_cpufreq_cpu_init,
 600         .exit   = acpi_cpufreq_cpu_exit,
 601         .resume = acpi_cpufreq_resume,
 602         .name   = "acpi-cpufreq",
 603         .owner  = THIS_MODULE,
 604         .attr   = acpi_cpufreq_attr,
 605 };
 606
 607
 608 static int __init
 609 acpi_cpufreq_init (void)
 610 {
 611         dprintk("acpi_cpufreq_init\n");
 612
 613         acpi_cpufreq_early_init_acpi();
 614
 615         return cpufreq_register_driver(&acpi_cpufreq_driver);
 616 }
 617
 618
 619 static void __exit
 620 acpi_cpufreq_exit (void)
 621 {
 622         unsigned int    i;
 623         dprintk("acpi_cpufreq_exit\n");
 624
 625         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 626
 627         for_each_possible_cpu(i) {
 628                 kfree(acpi_perf_data[i]);
 629                 acpi_perf_data[i] = NULL;
 630         }
 631         return;
 632 }
 633
 634 module_param(acpi_pstate_strict, uint, 0644);
 635 MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
 636
 637 late_initcall(acpi_cpufreq_init);
 638 module_exit(acpi_cpufreq_exit);
 639
 640 MODULE_ALIAS("acpi");