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
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/cpufreq.h>
  34
  35 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
  36 #include <linux/proc_fs.h>
  37 #include <linux/seq_file.h>
  38
  39 #include <asm/uaccess.h>
  40 #endif
  41
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/processor.h>
  44
  45
  46 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
  49 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
  50 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  51 ACPI_MODULE_NAME                ("acpi_processor")
  52
  53
  54 static DECLARE_MUTEX(performance_sem);
  55
  56 /*
  57  * _PPC support is implemented as a CPUfreq policy notifier:
  58  * This means each time a CPUfreq driver registered also with
  59  * the ACPI core is asked to change the speed policy, the maximum
  60  * value is adjusted so that it is within the platform limit.
  61  *
  62  * Also, when a new platform limit value is detected, the CPUfreq
  63  * policy is adjusted accordingly.
  64  */
  65
  66 #define PPC_REGISTERED   1
  67 #define PPC_IN_USE       2
  68
  69 static int acpi_processor_ppc_status = 0;
  70
  71 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
  72         unsigned long event,
  73         void *data)
  74 {
  75         struct cpufreq_policy *policy = data;
  76         struct acpi_processor *pr;
  77         unsigned int ppc = 0;
  78
  79         down(&performance_sem);
  80
  81         if (event != CPUFREQ_INCOMPATIBLE)
  82                 goto out;
  83
  84         pr = processors[policy->cpu];
  85         if (!pr || !pr->performance)
  86                 goto out;
  87
  88         ppc = (unsigned int) pr->performance_platform_limit;
  89         if (!ppc)
  90                 goto out;
  91
  92         if (ppc > pr->performance->state_count)
  93                 goto out;
  94
  95         cpufreq_verify_within_limits(policy, 0,
  96                 pr->performance->states[ppc].core_frequency * 1000);
  97
  98  out:
  99         up(&performance_sem);
 100
 101         return 0;
 102 }
 103
 104
 105 static struct notifier_block acpi_ppc_notifier_block = {
 106         .notifier_call = acpi_processor_ppc_notifier,
 107 };
 108
 109
 110 static int
 111 acpi_processor_get_platform_limit (
 112         struct acpi_processor*  pr)
 113 {
 114         acpi_status             status = 0;
 115         unsigned long           ppc = 0;
 116
 117         ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");
 118
 119         if (!pr)
 120                 return_VALUE(-EINVAL);
 121
 122         /*
 123          * _PPC indicates the maximum state currently supported by the platform
 124          * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
 125          */
 126         status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
 127
 128         if (status != AE_NOT_FOUND)
 129                 acpi_processor_ppc_status |= PPC_IN_USE;
 130
 131         if(ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 132                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
 133                 return_VALUE(-ENODEV);
 134         }
 135
 136         pr->performance_platform_limit = (int) ppc;
 137
 138         return_VALUE(0);
 139 }
 140
 141
 142 int acpi_processor_ppc_has_changed(
 143         struct acpi_processor *pr)
 144 {
 145         int ret = acpi_processor_get_platform_limit(pr);
 146         if (ret < 0)
 147                 return (ret);
 148         else
 149                 return cpufreq_update_policy(pr->id);
 150 }
 151
 152
 153 void acpi_processor_ppc_init(void) {
 154         if (!cpufreq_register_notifier(&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
 155                 acpi_processor_ppc_status |= PPC_REGISTERED;
 156         else
 157                 printk(KERN_DEBUG "Warning: Processor Platform Limit not supported.\n");
 158 }
 159
 160
 161 void acpi_processor_ppc_exit(void) {
 162         if (acpi_processor_ppc_status & PPC_REGISTERED)
 163                 cpufreq_unregister_notifier(&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER);
 164
 165         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 166 }
 167
 168
 169 static int
 170 acpi_processor_get_performance_control (
 171         struct acpi_processor *pr)
 172 {
 173         int                     result = 0;
 174         acpi_status             status = 0;
 175         struct acpi_buffer      buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 176         union acpi_object       *pct = NULL;
 177         union acpi_object       obj = {0};
 178
 179         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");
 180
 181         status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
 182         if(ACPI_FAILURE(status)) {
 183                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
 184                 return_VALUE(-ENODEV);
 185         }
 186
 187         pct = (union acpi_object *) buffer.pointer;
 188         if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
 189                 || (pct->package.count != 2)) {
 190                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
 191                 result = -EFAULT;
 192                 goto end;
 193         }
 194
 195         /*
 196          * control_register
 197          */
 198
 199         obj = pct->package.elements[0];
 200
 201         if ((obj.type != ACPI_TYPE_BUFFER)
 202                 || (obj.buffer.length < sizeof(struct acpi_pct_register))
 203                 || (obj.buffer.pointer == NULL)) {
 204                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 205                         "Invalid _PCT data (control_register)\n"));
 206                 result = -EFAULT;
 207                 goto end;
 208         }
 209         memcpy(&pr->performance->control_register, obj.buffer.pointer, sizeof(struct acpi_pct_register));
 210
 211
 212         /*
 213          * status_register
 214          */
 215
 216         obj = pct->package.elements[1];
 217
 218         if ((obj.type != ACPI_TYPE_BUFFER)
 219                 || (obj.buffer.length < sizeof(struct acpi_pct_register))
 220                 || (obj.buffer.pointer == NULL)) {
 221                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 222                         "Invalid _PCT data (status_register)\n"));
 223                 result = -EFAULT;
 224                 goto end;
 225         }
 226
 227         memcpy(&pr->performance->status_register, obj.buffer.pointer, sizeof(struct acpi_pct_register));
 228
 229 end:
 230         acpi_os_free(buffer.pointer);
 231
 232         return_VALUE(result);
 233 }
 234
 235
 236 static int
 237 acpi_processor_get_performance_states (
 238         struct acpi_processor   *pr)
 239 {
 240         int                     result = 0;
 241         acpi_status             status = AE_OK;
 242         struct acpi_buffer      buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 243         struct acpi_buffer      format = {sizeof("NNNNNN"), "NNNNNN"};
 244         struct acpi_buffer      state = {0, NULL};
 245         union acpi_object       *pss = NULL;
 246         int                     i;
 247
 248         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
 249
 250         status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
 251         if(ACPI_FAILURE(status)) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
 253                 return_VALUE(-ENODEV);
 254         }
 255
 256         pss = (union acpi_object *) buffer.pointer;
 257         if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
 258                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
 259                 result = -EFAULT;
 260                 goto end;
 261         }
 262
 263         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
 264                 pss->package.count));
 265
 266         pr->performance->state_count = pss->package.count;
 267         pr->performance->states = kmalloc(sizeof(struct acpi_processor_px) * pss->package.count, GFP_KERNEL);
 268         if (!pr->performance->states) {
 269                 result = -ENOMEM;
 270                 goto end;
 271         }
 272
 273         for (i = 0; i < pr->performance->state_count; i++) {
 274
 275                 struct acpi_processor_px *px = &(pr->performance->states[i]);
 276
 277                 state.length = sizeof(struct acpi_processor_px);
 278                 state.pointer = px;
 279
 280                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 281
 282                 status = acpi_extract_package(&(pss->package.elements[i]),
 283                         &format, &state);
 284                 if (ACPI_FAILURE(status)) {
 285                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
 286                         result = -EFAULT;
 287                         kfree(pr->performance->states);
 288                         goto end;
 289                 }
 290
 291                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 292                         "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
 293                         i,
 294                         (u32) px->core_frequency,
 295                         (u32) px->power,
 296                         (u32) px->transition_latency,
 297                         (u32) px->bus_master_latency,
 298                         (u32) px->control,
 299                         (u32) px->status));
 300
 301                 if (!px->core_frequency) {
 302                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data: freq is zero\n"));
 303                         result = -EFAULT;
 304                         kfree(pr->performance->states);
 305                         goto end;
 306                 }
 307         }
 308
 309 end:
 310         acpi_os_free(buffer.pointer);
 311
 312         return_VALUE(result);
 313 }
 314
 315
 316 static int
 317 acpi_processor_get_performance_info (
 318         struct acpi_processor   *pr)
 319 {
 320         int                     result = 0;
 321         acpi_status             status = AE_OK;
 322         acpi_handle             handle = NULL;
 323
 324         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");
 325
 326         if (!pr || !pr->performance || !pr->handle)
 327                 return_VALUE(-EINVAL);
 328
 329         acpi_processor_set_pdc(pr, pr->performance->pdc);
 330
 331         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 332         if (ACPI_FAILURE(status)) {
 333                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                         "ACPI-based processor performance control unavailable\n"));
 335                 return_VALUE(-ENODEV);
 336         }
 337
 338         result = acpi_processor_get_performance_control(pr);
 339         if (result)
 340                 return_VALUE(result);
 341
 342         result = acpi_processor_get_performance_states(pr);
 343         if (result)
 344                 return_VALUE(result);
 345
 346         result = acpi_processor_get_platform_limit(pr);
 347         if (result)
 348                 return_VALUE(result);
 349
 350         return_VALUE(0);
 351 }
 352
 353
 354 int acpi_processor_notify_smm(struct module *calling_module) {
 355         acpi_status             status;
 356         static int              is_done = 0;
 357
 358         ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
 359
 360         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 361                 return_VALUE(-EBUSY);
 362
 363         if (!try_module_get(calling_module))
 364                 return_VALUE(-EINVAL);
 365
 366         /* is_done is set to negative if an error occured,
 367          * and to postitive if _no_ error occured, but SMM
 368          * was already notified. This avoids double notification
 369          * which might lead to unexpected results...
 370          */
 371         if (is_done > 0) {
 372                 module_put(calling_module);
 373                 return_VALUE(0);
 374         }
 375         else if (is_done < 0) {
 376                 module_put(calling_module);
 377                 return_VALUE(is_done);
 378         }
 379
 380         is_done = -EIO;
 381
 382         /* Can't write pstate_cnt to smi_cmd if either value is zero */
 383         if ((!acpi_fadt.smi_cmd) ||
 384             (!acpi_fadt.pstate_cnt)) {
 385                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 386                         "No SMI port or pstate_cnt\n"));
 387                 module_put(calling_module);
 388                 return_VALUE(0);
 389         }
 390
 391         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 392
 393         /* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
 394          * it anyway, so we need to support it... */
 395         if (acpi_fadt_is_v1) {
 396                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Using v1.0 FADT reserved value for pstate_cnt\n"));
 397         }
 398
 399         status = acpi_os_write_port (acpi_fadt.smi_cmd,
 400                                      (u32) acpi_fadt.pstate_cnt, 8);
 401         if (ACPI_FAILURE (status)) {
 402                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 403                                   "Failed to write pstate_cnt [0x%x] to "
 404                                   "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 405                 module_put(calling_module);
 406                 return_VALUE(status);
 407         }
 408
 409         /* Success. If there's no _PPC, we need to fear nothing, so
 410          * we can allow the cpufreq driver to be rmmod'ed. */
 411         is_done = 1;
 412
 413         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 414                 module_put(calling_module);
 415
 416         return_VALUE(0);
 417 }
 418 EXPORT_SYMBOL(acpi_processor_notify_smm);
 419
 420
 421 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
 422 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
 423
 424 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
 425 static struct file_operations acpi_processor_perf_fops = {
 426         .open           = acpi_processor_perf_open_fs,
 427         .read           = seq_read,
 428         .llseek         = seq_lseek,
 429         .release        = single_release,
 430 };
 431
 432 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
 433 {
 434         struct acpi_processor   *pr = (struct acpi_processor *)seq->private;
 435         int                     i;
 436
 437         ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
 438
 439         if (!pr)
 440                 goto end;
 441
 442         if (!pr->performance) {
 443                 seq_puts(seq, "<not supported>\n");
 444                 goto end;
 445         }
 446
 447         seq_printf(seq, "state count:             %d\n"
 448                         "active state:            P%d\n",
 449                         pr->performance->state_count,
 450                         pr->performance->state);
 451
 452         seq_puts(seq, "states:\n");
 453         for (i = 0; i < pr->performance->state_count; i++)
 454                 seq_printf(seq, "   %cP%d:                  %d MHz, %d mW, %d uS\n",
 455                         (i == pr->performance->state?'*':' '), i,
 456                         (u32) pr->performance->states[i].core_frequency,
 457                         (u32) pr->performance->states[i].power,
 458                         (u32) pr->performance->states[i].transition_latency);
 459
 460 end:
 461         return_VALUE(0);
 462 }
 463
 464 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
 465 {
 466         return single_open(file, acpi_processor_perf_seq_show,
 467                                                 PDE(inode)->data);
 468 }
 469
 470 static ssize_t
 471 acpi_processor_write_performance (
 472         struct file             *file,
 473         const char              __user *buffer,
 474         size_t                  count,
 475         loff_t                  *data)
 476 {
 477         int                     result = 0;
 478         struct seq_file         *m = (struct seq_file *) file->private_data;
 479         struct acpi_processor   *pr = (struct acpi_processor *) m->private;
 480         struct acpi_processor_performance *perf;
 481         char                    state_string[12] = {'\0'};
 482         unsigned int            new_state = 0;
 483         struct cpufreq_policy   policy;
 484
 485         ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
 486
 487         if (!pr || (count > sizeof(state_string) - 1))
 488                 return_VALUE(-EINVAL);
 489
 490         perf = pr->performance;
 491         if (!perf)
 492                 return_VALUE(-EINVAL);
 493
 494         if (copy_from_user(state_string, buffer, count))
 495                 return_VALUE(-EFAULT);
 496
 497         state_string[count] = '\0';
 498         new_state = simple_strtoul(state_string, NULL, 0);
 499
 500         if (new_state >= perf->state_count)
 501                 return_VALUE(-EINVAL);
 502
 503         cpufreq_get_policy(&policy, pr->id);
 504
 505         policy.cpu = pr->id;
 506         policy.min = perf->states[new_state].core_frequency * 1000;
 507         policy.max = perf->states[new_state].core_frequency * 1000;
 508
 509         result = cpufreq_set_policy(&policy);
 510         if (result)
 511                 return_VALUE(result);
 512
 513         return_VALUE(count);
 514 }
 515
 516 static void
 517 acpi_cpufreq_add_file (
 518         struct acpi_processor *pr)
 519 {
 520         struct proc_dir_entry   *entry = NULL;
 521         struct acpi_device      *device = NULL;
 522
 523         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 524
 525         if (acpi_bus_get_device(pr->handle, &device))
 526                 return_VOID;
 527
 528         /* add file 'performance' [R/W] */
 529         entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 530                   S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
 531         if (!entry)
 532                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 533                         "Unable to create '%s' fs entry\n",
 534                         ACPI_PROCESSOR_FILE_PERFORMANCE));
 535         else {
 536                 entry->proc_fops = &acpi_processor_perf_fops;
 537                 entry->proc_fops->write = acpi_processor_write_performance;
 538                 entry->data = acpi_driver_data(device);
 539                 entry->owner = THIS_MODULE;
 540         }
 541         return_VOID;
 542 }
 543
 544 static void
 545 acpi_cpufreq_remove_file (
 546         struct acpi_processor *pr)
 547 {
 548         struct acpi_device      *device = NULL;
 549
 550         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 551
 552         if (acpi_bus_get_device(pr->handle, &device))
 553                 return_VOID;
 554
 555         /* remove file 'performance' */
 556         remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 557                   acpi_device_dir(device));
 558
 559         return_VOID;
 560 }
 561
 562 #else
 563 static void acpi_cpufreq_add_file (struct acpi_processor *pr) { return; }
 564 static void acpi_cpufreq_remove_file (struct acpi_processor *pr) { return; }
 565 #endif /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
 566
 567
 568 int
 569 acpi_processor_register_performance (
 570         struct acpi_processor_performance * performance,
 571         unsigned int cpu)
 572 {
 573         struct acpi_processor *pr;
 574
 575         ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
 576
 577         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 578                 return_VALUE(-EINVAL);
 579
 580         down(&performance_sem);
 581
 582         pr = processors[cpu];
 583         if (!pr) {
 584                 up(&performance_sem);
 585                 return_VALUE(-ENODEV);
 586         }
 587
 588         if (pr->performance) {
 589                 up(&performance_sem);
 590                 return_VALUE(-EBUSY);
 591         }
 592
 593         pr->performance = performance;
 594
 595         if (acpi_processor_get_performance_info(pr)) {
 596                 pr->performance = NULL;
 597                 up(&performance_sem);
 598                 return_VALUE(-EIO);
 599         }
 600
 601         acpi_cpufreq_add_file(pr);
 602
 603         up(&performance_sem);
 604         return_VALUE(0);
 605 }
 606 EXPORT_SYMBOL(acpi_processor_register_performance);
 607
 608
 609 void
 610 acpi_processor_unregister_performance (
 611         struct acpi_processor_performance * performance,
 612         unsigned int cpu)
 613 {
 614         struct acpi_processor *pr;
 615
 616         ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
 617
 618         down(&performance_sem);
 619
 620         pr = processors[cpu];
 621         if (!pr) {
 622                 up(&performance_sem);
 623                 return_VOID;
 624         }
 625
 626         kfree(pr->performance->states);
 627         pr->performance = NULL;
 628
 629         acpi_cpufreq_remove_file(pr);
 630
 631         up(&performance_sem);
 632
 633         return_VOID;
 634 }
 635 EXPORT_SYMBOL(acpi_processor_unregister_performance);