drivers/acpi/processor_perflib.c

   1 /*
   2  * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
   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) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  *
  11  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2 of the License, or (at
  16  *  your option) any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful, but
  19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  *  General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License along
  24  *  with this program; if not, write to the Free Software Foundation, Inc.,
  25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  26  *
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/cpufreq.h>
  33
  34 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
  35 #include <linux/proc_fs.h>
  36 #include <linux/seq_file.h>
  37
  38 #include <asm/uaccess.h>
  39 #endif
  40
  41 #include <acpi/acpi_bus.h>
  42 #include <acpi/processor.h>
  43
  44 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  45 #define ACPI_PROCESSOR_CLASS            "processor"
  46 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
  47 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("acpi_processor")
  50
  51 static DECLARE_MUTEX(performance_sem);
  52
  53 /*
  54  * _PPC support is implemented as a CPUfreq policy notifier:
  55  * This means each time a CPUfreq driver registered also with
  56  * the ACPI core is asked to change the speed policy, the maximum
  57  * value is adjusted so that it is within the platform limit.
  58  *
  59  * Also, when a new platform limit value is detected, the CPUfreq
  60  * policy is adjusted accordingly.
  61  */
  62
  63 #define PPC_REGISTERED   1
  64 #define PPC_IN_USE       2
  65
  66 static int acpi_processor_ppc_status = 0;
  67
  68 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
  69                                        unsigned long event, void *data)
  70 {
  71         struct cpufreq_policy *policy = data;
  72         struct acpi_processor *pr;
  73         unsigned int ppc = 0;
  74
  75         down(&performance_sem);
  76
  77         if (event != CPUFREQ_INCOMPATIBLE)
  78                 goto out;
  79
  80         pr = processors[policy->cpu];
  81         if (!pr || !pr->performance)
  82                 goto out;
  83
  84         ppc = (unsigned int)pr->performance_platform_limit;
  85         if (!ppc)
  86                 goto out;
  87
  88         if (ppc > pr->performance->state_count)
  89                 goto out;
  90
  91         cpufreq_verify_within_limits(policy, 0,
  92                                      pr->performance->states[ppc].
  93                                      core_frequency * 1000);
  94
  95       out:
  96         up(&performance_sem);
  97
  98         return 0;
  99 }
 100
 101 static struct notifier_block acpi_ppc_notifier_block = {
 102         .notifier_call = acpi_processor_ppc_notifier,
 103 };
 104
 105 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 106 {
 107         acpi_status status = 0;
 108         unsigned long ppc = 0;
 109
 110         ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");
 111
 112         if (!pr)
 113                 return_VALUE(-EINVAL);
 114
 115         /*
 116          * _PPC indicates the maximum state currently supported by the platform
 117          * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
 118          */
 119         status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
 120
 121         if (status != AE_NOT_FOUND)
 122                 acpi_processor_ppc_status |= PPC_IN_USE;
 123
 124         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 125                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
 126                 return_VALUE(-ENODEV);
 127         }
 128
 129         pr->performance_platform_limit = (int)ppc;
 130
 131         return_VALUE(0);
 132 }
 133
 134 int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
 135 {
 136         int ret = acpi_processor_get_platform_limit(pr);
 137         if (ret < 0)
 138                 return (ret);
 139         else
 140                 return cpufreq_update_policy(pr->id);
 141 }
 142
 143 void acpi_processor_ppc_init(void)
 144 {
 145         if (!cpufreq_register_notifier
 146             (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
 147                 acpi_processor_ppc_status |= PPC_REGISTERED;
 148         else
 149                 printk(KERN_DEBUG
 150                        "Warning: Processor Platform Limit not supported.\n");
 151 }
 152
 153 void acpi_processor_ppc_exit(void)
 154 {
 155         if (acpi_processor_ppc_status & PPC_REGISTERED)
 156                 cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
 157                                             CPUFREQ_POLICY_NOTIFIER);
 158
 159         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 160 }
 161
 162 static int acpi_processor_get_performance_control(struct acpi_processor *pr)
 163 {
 164         int result = 0;
 165         acpi_status status = 0;
 166         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 167         union acpi_object *pct = NULL;
 168         union acpi_object obj = { 0 };
 169
 170         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");
 171
 172         status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
 173         if (ACPI_FAILURE(status)) {
 174                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
 175                 return_VALUE(-ENODEV);
 176         }
 177
 178         pct = (union acpi_object *)buffer.pointer;
 179         if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
 180             || (pct->package.count != 2)) {
 181                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
 182                 result = -EFAULT;
 183                 goto end;
 184         }
 185
 186         /*
 187          * control_register
 188          */
 189
 190         obj = pct->package.elements[0];
 191
 192         if ((obj.type != ACPI_TYPE_BUFFER)
 193             || (obj.buffer.length < sizeof(struct acpi_pct_register))
 194             || (obj.buffer.pointer == NULL)) {
 195                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 196                                   "Invalid _PCT data (control_register)\n"));
 197                 result = -EFAULT;
 198                 goto end;
 199         }
 200         memcpy(&pr->performance->control_register, obj.buffer.pointer,
 201                sizeof(struct acpi_pct_register));
 202
 203         /*
 204          * status_register
 205          */
 206
 207         obj = pct->package.elements[1];
 208
 209         if ((obj.type != ACPI_TYPE_BUFFER)
 210             || (obj.buffer.length < sizeof(struct acpi_pct_register))
 211             || (obj.buffer.pointer == NULL)) {
 212                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 213                                   "Invalid _PCT data (status_register)\n"));
 214                 result = -EFAULT;
 215                 goto end;
 216         }
 217
 218         memcpy(&pr->performance->status_register, obj.buffer.pointer,
 219                sizeof(struct acpi_pct_register));
 220
 221       end:
 222         acpi_os_free(buffer.pointer);
 223
 224         return_VALUE(result);
 225 }
 226
 227 static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 228 {
 229         int result = 0;
 230         acpi_status status = AE_OK;
 231         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 232         struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
 233         struct acpi_buffer state = { 0, NULL };
 234         union acpi_object *pss = NULL;
 235         int i;
 236
 237         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
 238
 239         status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
 240         if (ACPI_FAILURE(status)) {
 241                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
 242                 return_VALUE(-ENODEV);
 243         }
 244
 245         pss = (union acpi_object *)buffer.pointer;
 246         if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
 247                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
 248                 result = -EFAULT;
 249                 goto end;
 250         }
 251
 252         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
 253                           pss->package.count));
 254
 255         pr->performance->state_count = pss->package.count;
 256         pr->performance->states =
 257             kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
 258                     GFP_KERNEL);
 259         if (!pr->performance->states) {
 260                 result = -ENOMEM;
 261                 goto end;
 262         }
 263
 264         for (i = 0; i < pr->performance->state_count; i++) {
 265
 266                 struct acpi_processor_px *px = &(pr->performance->states[i]);
 267
 268                 state.length = sizeof(struct acpi_processor_px);
 269                 state.pointer = px;
 270
 271                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 272
 273                 status = acpi_extract_package(&(pss->package.elements[i]),
 274                                               &format, &state);
 275                 if (ACPI_FAILURE(status)) {
 276                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 277                                           "Invalid _PSS data\n"));
 278                         result = -EFAULT;
 279                         kfree(pr->performance->states);
 280                         goto end;
 281                 }
 282
 283                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 284                                   "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
 285                                   i,
 286                                   (u32) px->core_frequency,
 287                                   (u32) px->power,
 288                                   (u32) px->transition_latency,
 289                                   (u32) px->bus_master_latency,
 290                                   (u32) px->control, (u32) px->status));
 291
 292                 if (!px->core_frequency) {
 293                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 294                                           "Invalid _PSS data: freq is zero\n"));
 295                         result = -EFAULT;
 296                         kfree(pr->performance->states);
 297                         goto end;
 298                 }
 299         }
 300
 301       end:
 302         acpi_os_free(buffer.pointer);
 303
 304         return_VALUE(result);
 305 }
 306
 307 static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 308 {
 309         int result = 0;
 310         acpi_status status = AE_OK;
 311         acpi_handle handle = NULL;
 312
 313         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");
 314
 315         if (!pr || !pr->performance || !pr->handle)
 316                 return_VALUE(-EINVAL);
 317
 318         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 319         if (ACPI_FAILURE(status)) {
 320                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 321                                   "ACPI-based processor performance control unavailable\n"));
 322                 return_VALUE(-ENODEV);
 323         }
 324
 325         result = acpi_processor_get_performance_control(pr);
 326         if (result)
 327                 return_VALUE(result);
 328
 329         result = acpi_processor_get_performance_states(pr);
 330         if (result)
 331                 return_VALUE(result);
 332
 333         result = acpi_processor_get_platform_limit(pr);
 334         if (result)
 335                 return_VALUE(result);
 336
 337         return_VALUE(0);
 338 }
 339
 340 int acpi_processor_notify_smm(struct module *calling_module)
 341 {
 342         acpi_status status;
 343         static int is_done = 0;
 344
 345         ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
 346
 347         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 348                 return_VALUE(-EBUSY);
 349
 350         if (!try_module_get(calling_module))
 351                 return_VALUE(-EINVAL);
 352
 353         /* is_done is set to negative if an error occured,
 354          * and to postitive if _no_ error occured, but SMM
 355          * was already notified. This avoids double notification
 356          * which might lead to unexpected results...
 357          */
 358         if (is_done > 0) {
 359                 module_put(calling_module);
 360                 return_VALUE(0);
 361         } else if (is_done < 0) {
 362                 module_put(calling_module);
 363                 return_VALUE(is_done);
 364         }
 365
 366         is_done = -EIO;
 367
 368         /* Can't write pstate_cnt to smi_cmd if either value is zero */
 369         if ((!acpi_fadt.smi_cmd) || (!acpi_fadt.pstate_cnt)) {
 370                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_cnt\n"));
 371                 module_put(calling_module);
 372                 return_VALUE(0);
 373         }
 374
 375         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 376                           "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n",
 377                           acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 378
 379         /* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
 380          * it anyway, so we need to support it... */
 381         if (acpi_fadt_is_v1) {
 382                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 383                                   "Using v1.0 FADT reserved value for pstate_cnt\n"));
 384         }
 385
 386         status = acpi_os_write_port(acpi_fadt.smi_cmd,
 387                                     (u32) acpi_fadt.pstate_cnt, 8);
 388         if (ACPI_FAILURE(status)) {
 389                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 390                                   "Failed to write pstate_cnt [0x%x] to "
 391                                   "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt,
 392                                   acpi_fadt.smi_cmd));
 393                 module_put(calling_module);
 394                 return_VALUE(status);
 395         }
 396
 397         /* Success. If there's no _PPC, we need to fear nothing, so
 398          * we can allow the cpufreq driver to be rmmod'ed. */
 399         is_done = 1;
 400
 401         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 402                 module_put(calling_module);
 403
 404         return_VALUE(0);
 405 }
 406
 407 EXPORT_SYMBOL(acpi_processor_notify_smm);
 408
 409 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
 410 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
 411
 412 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
 413 static struct file_operations acpi_processor_perf_fops = {
 414         .open = acpi_processor_perf_open_fs,
 415         .read = seq_read,
 416         .llseek = seq_lseek,
 417         .release = single_release,
 418 };
 419
 420 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
 421 {
 422         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
 423         int i;
 424
 425         ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
 426
 427         if (!pr)
 428                 goto end;
 429
 430         if (!pr->performance) {
 431                 seq_puts(seq, "<not supported>\n");
 432                 goto end;
 433         }
 434
 435         seq_printf(seq, "state count:             %d\n"
 436                    "active state:            P%d\n",
 437                    pr->performance->state_count, pr->performance->state);
 438
 439         seq_puts(seq, "states:\n");
 440         for (i = 0; i < pr->performance->state_count; i++)
 441                 seq_printf(seq,
 442                            "   %cP%d:                  %d MHz, %d mW, %d uS\n",
 443                            (i == pr->performance->state ? '*' : ' '), i,
 444                            (u32) pr->performance->states[i].core_frequency,
 445                            (u32) pr->performance->states[i].power,
 446                            (u32) pr->performance->states[i].transition_latency);
 447
 448       end:
 449         return_VALUE(0);
 450 }
 451
 452 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
 453 {
 454         return single_open(file, acpi_processor_perf_seq_show,
 455                            PDE(inode)->data);
 456 }
 457
 458 static ssize_t
 459 acpi_processor_write_performance(struct file *file,
 460                                  const char __user * buffer,
 461                                  size_t count, loff_t * data)
 462 {
 463         int result = 0;
 464         struct seq_file *m = (struct seq_file *)file->private_data;
 465         struct acpi_processor *pr = (struct acpi_processor *)m->private;
 466         struct acpi_processor_performance *perf;
 467         char state_string[12] = { '\0' };
 468         unsigned int new_state = 0;
 469         struct cpufreq_policy policy;
 470
 471         ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
 472
 473         if (!pr || (count > sizeof(state_string) - 1))
 474                 return_VALUE(-EINVAL);
 475
 476         perf = pr->performance;
 477         if (!perf)
 478                 return_VALUE(-EINVAL);
 479
 480         if (copy_from_user(state_string, buffer, count))
 481                 return_VALUE(-EFAULT);
 482
 483         state_string[count] = '\0';
 484         new_state = simple_strtoul(state_string, NULL, 0);
 485
 486         if (new_state >= perf->state_count)
 487                 return_VALUE(-EINVAL);
 488
 489         cpufreq_get_policy(&policy, pr->id);
 490
 491         policy.cpu = pr->id;
 492         policy.min = perf->states[new_state].core_frequency * 1000;
 493         policy.max = perf->states[new_state].core_frequency * 1000;
 494
 495         result = cpufreq_set_policy(&policy);
 496         if (result)
 497                 return_VALUE(result);
 498
 499         return_VALUE(count);
 500 }
 501
 502 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
 503 {
 504         struct proc_dir_entry *entry = NULL;
 505         struct acpi_device *device = NULL;
 506
 507         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 508
 509         if (acpi_bus_get_device(pr->handle, &device))
 510                 return_VOID;
 511
 512         /* add file 'performance' [R/W] */
 513         entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 514                                   S_IFREG | S_IRUGO | S_IWUSR,
 515                                   acpi_device_dir(device));
 516         if (!entry)
 517                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 518                                   "Unable to create '%s' fs entry\n",
 519                                   ACPI_PROCESSOR_FILE_PERFORMANCE));
 520         else {
 521                 entry->proc_fops = &acpi_processor_perf_fops;
 522                 entry->proc_fops->write = acpi_processor_write_performance;
 523                 entry->data = acpi_driver_data(device);
 524                 entry->owner = THIS_MODULE;
 525         }
 526         return_VOID;
 527 }
 528
 529 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
 530 {
 531         struct acpi_device *device = NULL;
 532
 533         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 534
 535         if (acpi_bus_get_device(pr->handle, &device))
 536                 return_VOID;
 537
 538         /* remove file 'performance' */
 539         remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 540                           acpi_device_dir(device));
 541
 542         return_VOID;
 543 }
 544
 545 #else
 546 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
 547 {
 548         return;
 549 }
 550 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
 551 {
 552         return;
 553 }
 554 #endif                          /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
 555
 556 int
 557 acpi_processor_register_performance(struct acpi_processor_performance
 558                                     *performance, unsigned int cpu)
 559 {
 560         struct acpi_processor *pr;
 561
 562         ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
 563
 564         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 565                 return_VALUE(-EINVAL);
 566
 567         down(&performance_sem);
 568
 569         pr = processors[cpu];
 570         if (!pr) {
 571                 up(&performance_sem);
 572                 return_VALUE(-ENODEV);
 573         }
 574
 575         if (pr->performance) {
 576                 up(&performance_sem);
 577                 return_VALUE(-EBUSY);
 578         }
 579
 580         pr->performance = performance;
 581
 582         if (acpi_processor_get_performance_info(pr)) {
 583                 pr->performance = NULL;
 584                 up(&performance_sem);
 585                 return_VALUE(-EIO);
 586         }
 587
 588         acpi_cpufreq_add_file(pr);
 589
 590         up(&performance_sem);
 591         return_VALUE(0);
 592 }
 593
 594 EXPORT_SYMBOL(acpi_processor_register_performance);
 595
 596 void
 597 acpi_processor_unregister_performance(struct acpi_processor_performance
 598                                       *performance, unsigned int cpu)
 599 {
 600         struct acpi_processor *pr;
 601
 602         ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
 603
 604         down(&performance_sem);
 605
 606         pr = processors[cpu];
 607         if (!pr) {
 608                 up(&performance_sem);
 609                 return_VOID;
 610         }
 611
 612         kfree(pr->performance->states);
 613         pr->performance = NULL;
 614
 615         acpi_cpufreq_remove_file(pr);
 616
 617         up(&performance_sem);
 618
 619         return_VOID;
 620 }
 621
 622 EXPORT_SYMBOL(acpi_processor_unregister_performance);