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/config.h>
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/cpufreq.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/seq_file.h>
  34 #include <asm/io.h>
  35 #include <asm/delay.h>
  36 #include <asm/uaccess.h>
  37
  38 #include <linux/acpi.h>
  39 #include <acpi/processor.h>
  40
  41 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
  42
  43 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  44 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  45 MODULE_LICENSE("GPL");
  46
  47
  48 struct cpufreq_acpi_io {
  49         struct acpi_processor_performance       acpi_data;
  50         struct cpufreq_frequency_table          *freq_table;
  51 };
  52
  53 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
  54
  55
  56 static int
  57 acpi_processor_write_port(
  58         u16     port,
  59         u8      bit_width,
  60         u32     value)
  61 {
  62         if (bit_width <= 8) {
  63                 outb(value, port);
  64         } else if (bit_width <= 16) {
  65                 outw(value, port);
  66         } else if (bit_width <= 32) {
  67                 outl(value, port);
  68         } else {
  69                 return -ENODEV;
  70         }
  71         return 0;
  72 }
  73
  74 static int
  75 acpi_processor_read_port(
  76         u16     port,
  77         u8      bit_width,
  78         u32     *ret)
  79 {
  80         *ret = 0;
  81         if (bit_width <= 8) {
  82                 *ret = inb(port);
  83         } else if (bit_width <= 16) {
  84                 *ret = inw(port);
  85         } else if (bit_width <= 32) {
  86                 *ret = inl(port);
  87         } else {
  88                 return -ENODEV;
  89         }
  90         return 0;
  91 }
  92
  93 static int
  94 acpi_processor_set_performance (
  95         struct cpufreq_acpi_io  *data,
  96         unsigned int            cpu,
  97         int                     state)
  98 {
  99         u16                     port = 0;
 100         u8                      bit_width = 0;
 101         int                     ret = 0;
 102         u32                     value = 0;
 103         int                     i = 0;
 104         struct cpufreq_freqs    cpufreq_freqs;
 105         cpumask_t               saved_mask;
 106         int                     retval;
 107
 108         dprintk("acpi_processor_set_performance\n");
 109
 110         /*
 111          * TBD: Use something other than set_cpus_allowed.
 112          * As set_cpus_allowed is a bit racy,
 113          * with any other set_cpus_allowed for this process.
 114          */
 115         saved_mask = current->cpus_allowed;
 116         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 117         if (smp_processor_id() != cpu) {
 118                 return (-EAGAIN);
 119         }
 120
 121         if (state == data->acpi_data.state) {
 122                 dprintk("Already at target state (P%d)\n", state);
 123                 retval = 0;
 124                 goto migrate_end;
 125         }
 126
 127         dprintk("Transitioning from P%d to P%d\n",
 128                 data->acpi_data.state, state);
 129
 130         /* cpufreq frequency struct */
 131         cpufreq_freqs.cpu = cpu;
 132         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
 133         cpufreq_freqs.new = data->freq_table[state].frequency;
 134
 135         /* notify cpufreq */
 136         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 137
 138         /*
 139          * First we write the target state's 'control' value to the
 140          * control_register.
 141          */
 142
 143         port = data->acpi_data.control_register.address;
 144         bit_width = data->acpi_data.control_register.bit_width;
 145         value = (u32) data->acpi_data.states[state].control;
 146
 147         dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
 148
 149         ret = acpi_processor_write_port(port, bit_width, value);
 150         if (ret) {
 151                 dprintk("Invalid port width 0x%04x\n", bit_width);
 152                 retval = ret;
 153                 goto migrate_end;
 154         }
 155
 156         /*
 157          * Then we read the 'status_register' and compare the value with the
 158          * target state's 'status' to make sure the transition was successful.
 159          * Note that we'll poll for up to 1ms (100 cycles of 10us) before
 160          * giving up.
 161          */
 162
 163         port = data->acpi_data.status_register.address;
 164         bit_width = data->acpi_data.status_register.bit_width;
 165
 166         dprintk("Looking for 0x%08x from port 0x%04x\n",
 167                 (u32) data->acpi_data.states[state].status, port);
 168
 169         for (i=0; i<100; i++) {
 170                 ret = acpi_processor_read_port(port, bit_width, &value);
 171                 if (ret) {
 172                         dprintk("Invalid port width 0x%04x\n", bit_width);
 173                         retval = ret;
 174                         goto migrate_end;
 175                 }
 176                 if (value == (u32) data->acpi_data.states[state].status)
 177                         break;
 178                 udelay(10);
 179         }
 180
 181         /* notify cpufreq */
 182         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 183
 184         if (value != (u32) data->acpi_data.states[state].status) {
 185                 unsigned int tmp = cpufreq_freqs.new;
 186                 cpufreq_freqs.new = cpufreq_freqs.old;
 187                 cpufreq_freqs.old = tmp;
 188                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 189                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 190                 printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
 191                 retval = -ENODEV;
 192                 goto migrate_end;
 193         }
 194
 195         dprintk("Transition successful after %d microseconds\n", i * 10);
 196
 197         data->acpi_data.state = state;
 198
 199         retval = 0;
 200 migrate_end:
 201         set_cpus_allowed(current, saved_mask);
 202         return (retval);
 203 }
 204
 205
 206 static int
 207 acpi_cpufreq_target (
 208         struct cpufreq_policy   *policy,
 209         unsigned int target_freq,
 210         unsigned int relation)
 211 {
 212         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 213         unsigned int next_state = 0;
 214         unsigned int result = 0;
 215
 216         dprintk("acpi_cpufreq_setpolicy\n");
 217
 218         result = cpufreq_frequency_table_target(policy,
 219                         data->freq_table,
 220                         target_freq,
 221                         relation,
 222                         &next_state);
 223         if (result)
 224                 return (result);
 225
 226         result = acpi_processor_set_performance (data, policy->cpu, next_state);
 227
 228         return (result);
 229 }
 230
 231
 232 static int
 233 acpi_cpufreq_verify (
 234         struct cpufreq_policy   *policy)
 235 {
 236         unsigned int result = 0;
 237         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 238
 239         dprintk("acpi_cpufreq_verify\n");
 240
 241         result = cpufreq_frequency_table_verify(policy,
 242                         data->freq_table);
 243
 244         return (result);
 245 }
 246
 247
 248 static unsigned long
 249 acpi_cpufreq_guess_freq (
 250         struct cpufreq_acpi_io  *data,
 251         unsigned int            cpu)
 252 {
 253         if (cpu_khz) {
 254                 /* search the closest match to cpu_khz */
 255                 unsigned int i;
 256                 unsigned long freq;
 257                 unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
 258
 259                 for (i=0; i < (data->acpi_data.state_count - 1); i++) {
 260                         freq = freqn;
 261                         freqn = data->acpi_data.states[i+1].core_frequency * 1000;
 262                         if ((2 * cpu_khz) > (freqn + freq)) {
 263                                 data->acpi_data.state = i;
 264                                 return (freq);
 265                         }
 266                 }
 267                 data->acpi_data.state = data->acpi_data.state_count - 1;
 268                 return (freqn);
 269         } else
 270                 /* assume CPU is at P0... */
 271                 data->acpi_data.state = 0;
 272                 return data->acpi_data.states[0].core_frequency * 1000;
 273
 274 }
 275
 276
 277 /*
 278  * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
 279  * of this driver
 280  * @perf: processor-specific acpi_io_data struct
 281  * @cpu: CPU being initialized
 282  *
 283  * To avoid issues with legacy OSes, some BIOSes require to be informed of
 284  * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC
 285  * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
 286  * driver/acpi/processor.c
 287  */
 288 static void
 289 acpi_processor_cpu_init_pdc_est(
 290                 struct acpi_processor_performance *perf,
 291                 unsigned int cpu,
 292                 struct acpi_object_list *obj_list
 293                 )
 294 {
 295         union acpi_object *obj;
 296         u32 *buf;
 297         struct cpuinfo_x86 *c = cpu_data + cpu;
 298         dprintk("acpi_processor_cpu_init_pdc_est\n");
 299
 300         if (!cpu_has(c, X86_FEATURE_EST))
 301                 return;
 302
 303         /* Initialize pdc. It will be used later. */
 304         if (!obj_list)
 305                 return;
 306
 307         if (!(obj_list->count && obj_list->pointer))
 308                 return;
 309
 310         obj = obj_list->pointer;
 311         if ((obj->buffer.length == 12) && obj->buffer.pointer) {
 312                 buf = (u32 *)obj->buffer.pointer;
 313                 buf[0] = ACPI_PDC_REVISION_ID;
 314                 buf[1] = 1;
 315                 buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
 316                 perf->pdc = obj_list;
 317         }
 318         return;
 319 }
 320
 321
 322 /* CPU specific PDC initialization */
 323 static void
 324 acpi_processor_cpu_init_pdc(
 325                 struct acpi_processor_performance *perf,
 326                 unsigned int cpu,
 327                 struct acpi_object_list *obj_list
 328                 )
 329 {
 330         struct cpuinfo_x86 *c = cpu_data + cpu;
 331         dprintk("acpi_processor_cpu_init_pdc\n");
 332         perf->pdc = NULL;
 333         if (cpu_has(c, X86_FEATURE_EST))
 334                 acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
 335         return;
 336 }
 337
 338
 339 static int
 340 acpi_cpufreq_cpu_init (
 341         struct cpufreq_policy   *policy)
 342 {
 343         unsigned int            i;
 344         unsigned int            cpu = policy->cpu;
 345         struct cpufreq_acpi_io  *data;
 346         unsigned int            result = 0;
 347
 348         union acpi_object               arg0 = {ACPI_TYPE_BUFFER};
 349         u32                             arg0_buf[3];
 350         struct acpi_object_list         arg_list = {1, &arg0};
 351
 352         dprintk("acpi_cpufreq_cpu_init\n");
 353         /* setup arg_list for _PDC settings */
 354         arg0.buffer.length = 12;
 355         arg0.buffer.pointer = (u8 *) arg0_buf;
 356
 357         data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 358         if (!data)
 359                 return (-ENOMEM);
 360         memset(data, 0, sizeof(struct cpufreq_acpi_io));
 361
 362         acpi_io_data[cpu] = data;
 363
 364         acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
 365         result = acpi_processor_register_performance(&data->acpi_data, cpu);
 366         data->acpi_data.pdc = NULL;
 367
 368         if (result)
 369                 goto err_free;
 370
 371         /* capability check */
 372         if (data->acpi_data.state_count <= 1) {
 373                 dprintk("No P-States\n");
 374                 result = -ENODEV;
 375                 goto err_unreg;
 376         }
 377         if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
 378             (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
 379                 dprintk("Unsupported address space [%d, %d]\n",
 380                         (u32) (data->acpi_data.control_register.space_id),
 381                         (u32) (data->acpi_data.status_register.space_id));
 382                 result = -ENODEV;
 383                 goto err_unreg;
 384         }
 385
 386         /* alloc freq_table */
 387         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
 388         if (!data->freq_table) {
 389                 result = -ENOMEM;
 390                 goto err_unreg;
 391         }
 392
 393         /* detect transition latency */
 394         policy->cpuinfo.transition_latency = 0;
 395         for (i=0; i<data->acpi_data.state_count; i++) {
 396                 if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
 397                         policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
 398         }
 399         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 400
 401         /* The current speed is unknown and not detectable by ACPI...  */
 402         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 403
 404         /* table init */
 405         for (i=0; i<=data->acpi_data.state_count; i++)
 406         {
 407                 data->freq_table[i].index = i;
 408                 if (i<data->acpi_data.state_count)
 409                         data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
 410                 else
 411                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
 412         }
 413
 414         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 415         if (result) {
 416                 goto err_freqfree;
 417         }
 418
 419         /* notify BIOS that we exist */
 420         acpi_processor_notify_smm(THIS_MODULE);
 421
 422         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
 423                cpu);
 424         for (i = 0; i < data->acpi_data.state_count; i++)
 425                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
 426                         (i == data->acpi_data.state?'*':' '), i,
 427                         (u32) data->acpi_data.states[i].core_frequency,
 428                         (u32) data->acpi_data.states[i].power,
 429                         (u32) data->acpi_data.states[i].transition_latency);
 430
 431         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 432         return (result);
 433
 434  err_freqfree:
 435         kfree(data->freq_table);
 436  err_unreg:
 437         acpi_processor_unregister_performance(&data->acpi_data, cpu);
 438  err_free:
 439         kfree(data);
 440         acpi_io_data[cpu] = NULL;
 441
 442         return (result);
 443 }
 444
 445
 446 static int
 447 acpi_cpufreq_cpu_exit (
 448         struct cpufreq_policy   *policy)
 449 {
 450         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 451
 452
 453         dprintk("acpi_cpufreq_cpu_exit\n");
 454
 455         if (data) {
 456                 cpufreq_frequency_table_put_attr(policy->cpu);
 457                 acpi_io_data[policy->cpu] = NULL;
 458                 acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
 459                 kfree(data);
 460         }
 461
 462         return (0);
 463 }
 464
 465
 466 static struct freq_attr* acpi_cpufreq_attr[] = {
 467         &cpufreq_freq_attr_scaling_available_freqs,
 468         NULL,
 469 };
 470
 471 static struct cpufreq_driver acpi_cpufreq_driver = {
 472         .verify         = acpi_cpufreq_verify,
 473         .target         = acpi_cpufreq_target,
 474         .init           = acpi_cpufreq_cpu_init,
 475         .exit           = acpi_cpufreq_cpu_exit,
 476         .name           = "acpi-cpufreq",
 477         .owner          = THIS_MODULE,
 478         .attr           = acpi_cpufreq_attr,
 479 };
 480
 481
 482 static int __init
 483 acpi_cpufreq_init (void)
 484 {
 485         int                     result = 0;
 486
 487         dprintk("acpi_cpufreq_init\n");
 488
 489         result = cpufreq_register_driver(&acpi_cpufreq_driver);
 490
 491         return (result);
 492 }
 493
 494
 495 static void __exit
 496 acpi_cpufreq_exit (void)
 497 {
 498         dprintk("acpi_cpufreq_exit\n");
 499
 500         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 501
 502         return;
 503 }
 504
 505
 506 late_initcall(acpi_cpufreq_init);
 507 module_exit(acpi_cpufreq_exit);
 508
 509 MODULE_ALIAS("acpi");