arch/ia64/kernel/cpufreq/acpi-cpufreq.c

   1 /*
   2  * arch/ia64/kernel/cpufreq/acpi-cpufreq.c
   3  * This file provides the ACPI based P-state support. This
   4  * module works with generic cpufreq infrastructure. Most of
   5  * the code is based on i386 version
   6  * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
   7  *
   8  * Copyright (C) 2005 Intel Corp
   9  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/cpufreq.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/seq_file.h>
  18 #include <asm/io.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/pal.h>
  21
  22 #include <linux/acpi.h>
  23 #include <acpi/processor.h>
  24
  25 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
  26
  27 MODULE_AUTHOR("Venkatesh Pallipadi");
  28 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  29 MODULE_LICENSE("GPL");
  30
  31
  32 struct cpufreq_acpi_io {
  33         struct acpi_processor_performance       acpi_data;
  34         struct cpufreq_frequency_table          *freq_table;
  35         unsigned int                            resume;
  36 };
  37
  38 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
  39
  40 static struct cpufreq_driver acpi_cpufreq_driver;
  41
  42
  43 static int
  44 processor_set_pstate (
  45         u32     value)
  46 {
  47         s64 retval;
  48
  49         dprintk("processor_set_pstate\n");
  50
  51         retval = ia64_pal_set_pstate((u64)value);
  52
  53         if (retval) {
  54                 dprintk("Failed to set freq to 0x%x, with error 0x%x\n",
  55                         value, retval);
  56                 return -ENODEV;
  57         }
  58         return (int)retval;
  59 }
  60
  61
  62 static int
  63 processor_get_pstate (
  64         u32     *value)
  65 {
  66         u64     pstate_index = 0;
  67         s64     retval;
  68
  69         dprintk("processor_get_pstate\n");
  70
  71         retval = ia64_pal_get_pstate(&pstate_index);
  72         *value = (u32) pstate_index;
  73
  74         if (retval)
  75                 dprintk("Failed to get current freq with "
  76                         "error 0x%x, idx 0x%x\n", retval, *value);
  77
  78         return (int)retval;
  79 }
  80
  81
  82 /* To be used only after data->acpi_data is initialized */
  83 static unsigned
  84 extract_clock (
  85         struct cpufreq_acpi_io *data,
  86         unsigned value,
  87         unsigned int cpu)
  88 {
  89         unsigned long i;
  90
  91         dprintk("extract_clock\n");
  92
  93         for (i = 0; i < data->acpi_data.state_count; i++) {
  94                 if (value >= data->acpi_data.states[i].control)
  95                         return data->acpi_data.states[i].core_frequency;
  96         }
  97         return data->acpi_data.states[i-1].core_frequency;
  98 }
  99
 100
 101 static unsigned int
 102 processor_get_freq (
 103         struct cpufreq_acpi_io  *data,
 104         unsigned int            cpu)
 105 {
 106         int                     ret = 0;
 107         u32                     value = 0;
 108         cpumask_t               saved_mask;
 109         unsigned long           clock_freq;
 110
 111         dprintk("processor_get_freq\n");
 112
 113         saved_mask = current->cpus_allowed;
 114         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 115         if (smp_processor_id() != cpu) {
 116                 ret = -EAGAIN;
 117                 goto migrate_end;
 118         }
 119
 120         /*
 121          * processor_get_pstate gets the average frequency since the
 122          * last get. So, do two PAL_get_freq()...
 123          */
 124         ret = processor_get_pstate(&value);
 125         ret = processor_get_pstate(&value);
 126
 127         if (ret) {
 128                 set_cpus_allowed(current, saved_mask);
 129                 printk(KERN_WARNING "get performance failed with error %d\n",
 130                        ret);
 131                 ret = -EAGAIN;
 132                 goto migrate_end;
 133         }
 134         clock_freq = extract_clock(data, value, cpu);
 135         ret = (clock_freq*1000);
 136
 137 migrate_end:
 138         set_cpus_allowed(current, saved_mask);
 139         return ret;
 140 }
 141
 142
 143 static int
 144 processor_set_freq (
 145         struct cpufreq_acpi_io  *data,
 146         unsigned int            cpu,
 147         int                     state)
 148 {
 149         int                     ret = 0;
 150         u32                     value = 0;
 151         struct cpufreq_freqs    cpufreq_freqs;
 152         cpumask_t               saved_mask;
 153         int                     retval;
 154
 155         dprintk("processor_set_freq\n");
 156
 157         saved_mask = current->cpus_allowed;
 158         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 159         if (smp_processor_id() != cpu) {
 160                 retval = -EAGAIN;
 161                 goto migrate_end;
 162         }
 163
 164         if (state == data->acpi_data.state) {
 165                 if (unlikely(data->resume)) {
 166                         dprintk("Called after resume, resetting to P%d\n", state);
 167                         data->resume = 0;
 168                 } else {
 169                         dprintk("Already at target state (P%d)\n", state);
 170                         retval = 0;
 171                         goto migrate_end;
 172                 }
 173         }
 174
 175         dprintk("Transitioning from P%d to P%d\n",
 176                 data->acpi_data.state, state);
 177
 178         /* cpufreq frequency struct */
 179         cpufreq_freqs.cpu = cpu;
 180         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
 181         cpufreq_freqs.new = data->freq_table[state].frequency;
 182
 183         /* notify cpufreq */
 184         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 185
 186         /*
 187          * First we write the target state's 'control' value to the
 188          * control_register.
 189          */
 190
 191         value = (u32) data->acpi_data.states[state].control;
 192
 193         dprintk("Transitioning to state: 0x%08x\n", value);
 194
 195         ret = processor_set_pstate(value);
 196         if (ret) {
 197                 unsigned int tmp = cpufreq_freqs.new;
 198                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 199                 cpufreq_freqs.new = cpufreq_freqs.old;
 200                 cpufreq_freqs.old = tmp;
 201                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 202                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 203                 printk(KERN_WARNING "Transition failed with error %d\n", ret);
 204                 retval = -ENODEV;
 205                 goto migrate_end;
 206         }
 207
 208         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 209
 210         data->acpi_data.state = state;
 211
 212         retval = 0;
 213
 214 migrate_end:
 215         set_cpus_allowed(current, saved_mask);
 216         return (retval);
 217 }
 218
 219
 220 static unsigned int
 221 acpi_cpufreq_get (
 222         unsigned int            cpu)
 223 {
 224         struct cpufreq_acpi_io *data = acpi_io_data[cpu];
 225
 226         dprintk("acpi_cpufreq_get\n");
 227
 228         return processor_get_freq(data, cpu);
 229 }
 230
 231
 232 static int
 233 acpi_cpufreq_target (
 234         struct cpufreq_policy   *policy,
 235         unsigned int target_freq,
 236         unsigned int relation)
 237 {
 238         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 239         unsigned int next_state = 0;
 240         unsigned int result = 0;
 241
 242         dprintk("acpi_cpufreq_setpolicy\n");
 243
 244         result = cpufreq_frequency_table_target(policy,
 245                         data->freq_table, target_freq, relation, &next_state);
 246         if (result)
 247                 return (result);
 248
 249         result = processor_set_freq(data, policy->cpu, next_state);
 250
 251         return (result);
 252 }
 253
 254
 255 static int
 256 acpi_cpufreq_verify (
 257         struct cpufreq_policy   *policy)
 258 {
 259         unsigned int result = 0;
 260         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 261
 262         dprintk("acpi_cpufreq_verify\n");
 263
 264         result = cpufreq_frequency_table_verify(policy,
 265                         data->freq_table);
 266
 267         return (result);
 268 }
 269
 270
 271 static int
 272 acpi_cpufreq_cpu_init (
 273         struct cpufreq_policy   *policy)
 274 {
 275         unsigned int            i;
 276         unsigned int            cpu = policy->cpu;
 277         struct cpufreq_acpi_io  *data;
 278         unsigned int            result = 0;
 279
 280         dprintk("acpi_cpufreq_cpu_init\n");
 281
 282         data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 283         if (!data)
 284                 return (-ENOMEM);
 285
 286         memset(data, 0, sizeof(struct cpufreq_acpi_io));
 287
 288         acpi_io_data[cpu] = data;
 289
 290         result = acpi_processor_register_performance(&data->acpi_data, cpu);
 291
 292         if (result)
 293                 goto err_free;
 294
 295         /* capability check */
 296         if (data->acpi_data.state_count <= 1) {
 297                 dprintk("No P-States\n");
 298                 result = -ENODEV;
 299                 goto err_unreg;
 300         }
 301
 302         if ((data->acpi_data.control_register.space_id !=
 303                                         ACPI_ADR_SPACE_FIXED_HARDWARE) ||
 304             (data->acpi_data.status_register.space_id !=
 305                                         ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 306                 dprintk("Unsupported address space [%d, %d]\n",
 307                         (u32) (data->acpi_data.control_register.space_id),
 308                         (u32) (data->acpi_data.status_register.space_id));
 309                 result = -ENODEV;
 310                 goto err_unreg;
 311         }
 312
 313         /* alloc freq_table */
 314         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
 315                                    (data->acpi_data.state_count + 1),
 316                                    GFP_KERNEL);
 317         if (!data->freq_table) {
 318                 result = -ENOMEM;
 319                 goto err_unreg;
 320         }
 321
 322         /* detect transition latency */
 323         policy->cpuinfo.transition_latency = 0;
 324         for (i=0; i<data->acpi_data.state_count; i++) {
 325                 if ((data->acpi_data.states[i].transition_latency * 1000) >
 326                     policy->cpuinfo.transition_latency) {
 327                         policy->cpuinfo.transition_latency =
 328                             data->acpi_data.states[i].transition_latency * 1000;
 329                 }
 330         }
 331         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 332
 333         policy->cur = processor_get_freq(data, policy->cpu);
 334
 335         /* table init */
 336         for (i = 0; i <= data->acpi_data.state_count; i++)
 337         {
 338                 data->freq_table[i].index = i;
 339                 if (i < data->acpi_data.state_count) {
 340                         data->freq_table[i].frequency =
 341                               data->acpi_data.states[i].core_frequency * 1000;
 342                 } else {
 343                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
 344                 }
 345         }
 346
 347         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 348         if (result) {
 349                 goto err_freqfree;
 350         }
 351
 352         /* notify BIOS that we exist */
 353         acpi_processor_notify_smm(THIS_MODULE);
 354
 355         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
 356                "activated.\n", cpu);
 357
 358         for (i = 0; i < data->acpi_data.state_count; i++)
 359                 dprintk("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
 360                         (i == data->acpi_data.state?'*':' '), i,
 361                         (u32) data->acpi_data.states[i].core_frequency,
 362                         (u32) data->acpi_data.states[i].power,
 363                         (u32) data->acpi_data.states[i].transition_latency,
 364                         (u32) data->acpi_data.states[i].bus_master_latency,
 365                         (u32) data->acpi_data.states[i].status,
 366                         (u32) data->acpi_data.states[i].control);
 367
 368         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 369
 370         /* the first call to ->target() should result in us actually
 371          * writing something to the appropriate registers. */
 372         data->resume = 1;
 373
 374         return (result);
 375
 376  err_freqfree:
 377         kfree(data->freq_table);
 378  err_unreg:
 379         acpi_processor_unregister_performance(&data->acpi_data, cpu);
 380  err_free:
 381         kfree(data);
 382         acpi_io_data[cpu] = NULL;
 383
 384         return (result);
 385 }
 386
 387
 388 static int
 389 acpi_cpufreq_cpu_exit (
 390         struct cpufreq_policy   *policy)
 391 {
 392         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 393
 394         dprintk("acpi_cpufreq_cpu_exit\n");
 395
 396         if (data) {
 397                 cpufreq_frequency_table_put_attr(policy->cpu);
 398                 acpi_io_data[policy->cpu] = NULL;
 399                 acpi_processor_unregister_performance(&data->acpi_data,
 400                                                       policy->cpu);
 401                 kfree(data);
 402         }
 403
 404         return (0);
 405 }
 406
 407
 408 static struct freq_attr* acpi_cpufreq_attr[] = {
 409         &cpufreq_freq_attr_scaling_available_freqs,
 410         NULL,
 411 };
 412
 413
 414 static struct cpufreq_driver acpi_cpufreq_driver = {
 415         .verify         = acpi_cpufreq_verify,
 416         .target         = acpi_cpufreq_target,
 417         .get            = acpi_cpufreq_get,
 418         .init           = acpi_cpufreq_cpu_init,
 419         .exit           = acpi_cpufreq_cpu_exit,
 420         .name           = "acpi-cpufreq",
 421         .owner          = THIS_MODULE,
 422         .attr           = acpi_cpufreq_attr,
 423 };
 424
 425
 426 static int __init
 427 acpi_cpufreq_init (void)
 428 {
 429         dprintk("acpi_cpufreq_init\n");
 430
 431         return cpufreq_register_driver(&acpi_cpufreq_driver);
 432 }
 433
 434
 435 static void __exit
 436 acpi_cpufreq_exit (void)
 437 {
 438         dprintk("acpi_cpufreq_exit\n");
 439
 440         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 441         return;
 442 }
 443
 444
 445 late_initcall(acpi_cpufreq_init);
 446 module_exit(acpi_cpufreq_exit);
 447