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         acpi_processor_set_pdc(pr, pr->performance->pdc);
 319
 320         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 321         if (ACPI_FAILURE(status)) {
 322                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 323                                   "ACPI-based processor performance control unavailable\n"));
 324                 return_VALUE(-ENODEV);
 325         }
 326
 327         result = acpi_processor_get_performance_control(pr);
 328         if (result)
 329                 return_VALUE(result);
 330
 331         result = acpi_processor_get_performance_states(pr);
 332         if (result)
 333                 return_VALUE(result);
 334
 335         result = acpi_processor_get_platform_limit(pr);
 336         if (result)
 337                 return_VALUE(result);
 338
 339         return_VALUE(0);
 340 }
 341
 342 int acpi_processor_notify_smm(struct module *calling_module)
 343 {
 344         acpi_status status;
 345         static int is_done = 0;
 346
 347         ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
 348
 349         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 350                 return_VALUE(-EBUSY);
 351
 352         if (!try_module_get(calling_module))
 353                 return_VALUE(-EINVAL);
 354
 355         /* is_done is set to negative if an error occured,
 356          * and to postitive if _no_ error occured, but SMM
 357          * was already notified. This avoids double notification
 358          * which might lead to unexpected results...
 359          */
 360         if (is_done > 0) {
 361                 module_put(calling_module);
 362                 return_VALUE(0);
 363         } else if (is_done < 0) {
 364                 module_put(calling_module);
 365                 return_VALUE(is_done);
 366         }
 367
 368         is_done = -EIO;
 369
 370         /* Can't write pstate_cnt to smi_cmd if either value is zero */
 371         if ((!acpi_fadt.smi_cmd) || (!acpi_fadt.pstate_cnt)) {
 372                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_cnt\n"));
 373                 module_put(calling_module);
 374                 return_VALUE(0);
 375         }
 376
 377         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 378                           "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n",
 379                           acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 380
 381         /* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
 382          * it anyway, so we need to support it... */
 383         if (acpi_fadt_is_v1) {
 384                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 385                                   "Using v1.0 FADT reserved value for pstate_cnt\n"));
 386         }
 387
 388         status = acpi_os_write_port(acpi_fadt.smi_cmd,
 389                                     (u32) acpi_fadt.pstate_cnt, 8);
 390         if (ACPI_FAILURE(status)) {
 391                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 392                                   "Failed to write pstate_cnt [0x%x] to "
 393                                   "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt,
 394                                   acpi_fadt.smi_cmd));
 395                 module_put(calling_module);
 396                 return_VALUE(status);
 397         }
 398
 399         /* Success. If there's no _PPC, we need to fear nothing, so
 400          * we can allow the cpufreq driver to be rmmod'ed. */
 401         is_done = 1;
 402
 403         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 404                 module_put(calling_module);
 405
 406         return_VALUE(0);
 407 }
 408
 409 EXPORT_SYMBOL(acpi_processor_notify_smm);
 410
 411 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
 412 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
 413
 414 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
 415 static struct file_operations acpi_processor_perf_fops = {
 416         .open = acpi_processor_perf_open_fs,
 417         .read = seq_read,
 418         .llseek = seq_lseek,
 419         .release = single_release,
 420 };
 421
 422 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
 423 {
 424         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
 425         int i;
 426
 427         ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
 428
 429         if (!pr)
 430                 goto end;
 431
 432         if (!pr->performance) {
 433                 seq_puts(seq, "<not supported>\n");
 434                 goto end;
 435         }
 436
 437         seq_printf(seq, "state count:             %d\n"
 438                    "active state:            P%d\n",
 439                    pr->performance->state_count, pr->performance->state);
 440
 441         seq_puts(seq, "states:\n");
 442         for (i = 0; i < pr->performance->state_count; i++)
 443                 seq_printf(seq,
 444                            "   %cP%d:                  %d MHz, %d mW, %d uS\n",
 445                            (i == pr->performance->state ? '*' : ' '), i,
 446                            (u32) pr->performance->states[i].core_frequency,
 447                            (u32) pr->performance->states[i].power,
 448                            (u32) pr->performance->states[i].transition_latency);
 449
 450       end:
 451         return_VALUE(0);
 452 }
 453
 454 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
 455 {
 456         return single_open(file, acpi_processor_perf_seq_show,
 457                            PDE(inode)->data);
 458 }
 459
 460 static ssize_t
 461 acpi_processor_write_performance(struct file *file,
 462                                  const char __user * buffer,
 463                                  size_t count, loff_t * data)
 464 {
 465         int result = 0;
 466         struct seq_file *m = (struct seq_file *)file->private_data;
 467         struct acpi_processor *pr = (struct acpi_processor *)m->private;
 468         struct acpi_processor_performance *perf;
 469         char state_string[12] = { '\0' };
 470         unsigned int new_state = 0;
 471         struct cpufreq_policy policy;
 472
 473         ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
 474
 475         if (!pr || (count > sizeof(state_string) - 1))
 476                 return_VALUE(-EINVAL);
 477
 478         perf = pr->performance;
 479         if (!perf)
 480                 return_VALUE(-EINVAL);
 481
 482         if (copy_from_user(state_string, buffer, count))
 483                 return_VALUE(-EFAULT);
 484
 485         state_string[count] = '\0';
 486         new_state = simple_strtoul(state_string, NULL, 0);
 487
 488         if (new_state >= perf->state_count)
 489                 return_VALUE(-EINVAL);
 490
 491         cpufreq_get_policy(&policy, pr->id);
 492
 493         policy.cpu = pr->id;
 494         policy.min = perf->states[new_state].core_frequency * 1000;
 495         policy.max = perf->states[new_state].core_frequency * 1000;
 496
 497         result = cpufreq_set_policy(&policy);
 498         if (result)
 499                 return_VALUE(result);
 500
 501         return_VALUE(count);
 502 }
 503
 504 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
 505 {
 506         struct proc_dir_entry *entry = NULL;
 507         struct acpi_device *device = NULL;
 508
 509         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 510
 511         if (acpi_bus_get_device(pr->handle, &device))
 512                 return_VOID;
 513
 514         /* add file 'performance' [R/W] */
 515         entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 516                                   S_IFREG | S_IRUGO | S_IWUSR,
 517                                   acpi_device_dir(device));
 518         if (!entry)
 519                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 520                                   "Unable to create '%s' fs entry\n",
 521                                   ACPI_PROCESSOR_FILE_PERFORMANCE));
 522         else {
 523                 entry->proc_fops = &acpi_processor_perf_fops;
 524                 entry->proc_fops->write = acpi_processor_write_performance;
 525                 entry->data = acpi_driver_data(device);
 526                 entry->owner = THIS_MODULE;
 527         }
 528         return_VOID;
 529 }
 530
 531 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
 532 {
 533         struct acpi_device *device = NULL;
 534
 535         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 536
 537         if (acpi_bus_get_device(pr->handle, &device))
 538                 return_VOID;
 539
 540         /* remove file 'performance' */
 541         remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 542                           acpi_device_dir(device));
 543
 544         return_VOID;
 545 }
 546
 547 #else
 548 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
 549 {
 550         return;
 551 }
 552 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
 553 {
 554         return;
 555 }
 556 #endif                          /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
 557
 558 int
 559 acpi_processor_register_performance(struct acpi_processor_performance
 560                                     *performance, unsigned int cpu)
 561 {
 562         struct acpi_processor *pr;
 563
 564         ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
 565
 566         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 567                 return_VALUE(-EINVAL);
 568
 569         down(&performance_sem);
 570
 571         pr = processors[cpu];
 572         if (!pr) {
 573                 up(&performance_sem);
 574                 return_VALUE(-ENODEV);
 575         }
 576
 577         if (pr->performance) {
 578                 up(&performance_sem);
 579                 return_VALUE(-EBUSY);
 580         }
 581
 582         pr->performance = performance;
 583
 584         if (acpi_processor_get_performance_info(pr)) {
 585                 pr->performance = NULL;
 586                 up(&performance_sem);
 587                 return_VALUE(-EIO);
 588         }
 589
 590         acpi_cpufreq_add_file(pr);
 591
 592         up(&performance_sem);
 593         return_VALUE(0);
 594 }
 595
 596 EXPORT_SYMBOL(acpi_processor_register_performance);
 597
 598 void
 599 acpi_processor_unregister_performance(struct acpi_processor_performance
 600                                       *performance, unsigned int cpu)
 601 {
 602         struct acpi_processor *pr;
 603
 604         ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
 605
 606         down(&performance_sem);
 607
 608         pr = processors[cpu];
 609         if (!pr) {
 610                 up(&performance_sem);
 611                 return_VOID;
 612         }
 613
 614         kfree(pr->performance->states);
 615         pr->performance = NULL;
 616
 617         acpi_cpufreq_remove_file(pr);
 618
 619         up(&performance_sem);
 620
 621         return_VOID;
 622 }
 623
 624 EXPORT_SYMBOL(acpi_processor_unregister_performance);