git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   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, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/acpi.h>
  38 #include <linux/dmi.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>        /* need_resched() */
  41 #include <linux/pm_qos_params.h>
  42 #include <linux/clockchips.h>
  43 #include <linux/cpuidle.h>
  44 #include <linux/irqflags.h>
  45
  46 /*
  47  * Include the apic definitions for x86 to have the APIC timer related defines
  48  * available also for UP (on SMP it gets magically included via linux/smp.h).
  49  * asm/acpi.h is not an option, as it would require more include magic. Also
  50  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  51  */
  52 #ifdef CONFIG_X86
  53 #include <asm/apic.h>
  54 #endif
  55
  56 #include <asm/io.h>
  57 #include <asm/uaccess.h>
  58
  59 #include <acpi/acpi_bus.h>
  60 #include <acpi/processor.h>
  61 #include <asm/processor.h>
  62
  63 #define ACPI_PROCESSOR_CLASS            "processor"
  64 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  65 ACPI_MODULE_NAME("processor_idle");
  66 #define ACPI_PROCESSOR_FILE_POWER       "power"
  67 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  68 #define C2_OVERHEAD                     1       /* 1us */
  69 #define C3_OVERHEAD                     1       /* 1us */
  70 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  71
  72 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  73 module_param(max_cstate, uint, 0000);
  74 static unsigned int nocst __read_mostly;
  75 module_param(nocst, uint, 0000);
  76
  77 static unsigned int latency_factor __read_mostly = 2;
  78 module_param(latency_factor, uint, 0644);
  79
  80 static s64 us_to_pm_timer_ticks(s64 t)
  81 {
  82         return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
  83 }
  84 /*
  85  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  86  * For now disable this. Probably a bug somewhere else.
  87  *
  88  * To skip this limit, boot/load with a large max_cstate limit.
  89  */
  90 static int set_max_cstate(const struct dmi_system_id *id)
  91 {
  92         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  93                 return 0;
  94
  95         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  96                " Override with \"processor.max_cstate=%d\"\n", id->ident,
  97                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  98
  99         max_cstate = (long)id->driver_data;
 100
 101         return 0;
 102 }
 103
 104 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 105    callers to only run once -AK */
 106 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 107         { set_max_cstate, "Clevo 5600D", {
 108           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 109           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 110          (void *)2},
 111         {},
 112 };
 113
 114
 115 /*
 116  * Callers should disable interrupts before the call and enable
 117  * interrupts after return.
 118  */
 119 static void acpi_safe_halt(void)
 120 {
 121         current_thread_info()->status &= ~TS_POLLING;
 122         /*
 123          * TS_POLLING-cleared state must be visible before we
 124          * test NEED_RESCHED:
 125          */
 126         smp_mb();
 127         if (!need_resched()) {
 128                 safe_halt();
 129                 local_irq_disable();
 130         }
 131         current_thread_info()->status |= TS_POLLING;
 132 }
 133
 134 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 135
 136 /*
 137  * Some BIOS implementations switch to C3 in the published C2 state.
 138  * This seems to be a common problem on AMD boxen, but other vendors
 139  * are affected too. We pick the most conservative approach: we assume
 140  * that the local APIC stops in both C2 and C3.
 141  */
 142 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 143                                    struct acpi_processor_cx *cx)
 144 {
 145         struct acpi_processor_power *pwr = &pr->power;
 146         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 147
 148         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 149                 return;
 150
 151         /*
 152          * Check, if one of the previous states already marked the lapic
 153          * unstable
 154          */
 155         if (pwr->timer_broadcast_on_state < state)
 156                 return;
 157
 158         if (cx->type >= type)
 159                 pr->power.timer_broadcast_on_state = state;
 160 }
 161
 162 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
 163 {
 164         unsigned long reason;
 165
 166         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 167                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 168
 169         clockevents_notify(reason, &pr->id);
 170 }
 171
 172 /* Power(C) State timer broadcast control */
 173 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 174                                        struct acpi_processor_cx *cx,
 175                                        int broadcast)
 176 {
 177         int state = cx - pr->power.states;
 178
 179         if (state >= pr->power.timer_broadcast_on_state) {
 180                 unsigned long reason;
 181
 182                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 183                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 184                 clockevents_notify(reason, &pr->id);
 185         }
 186 }
 187
 188 #else
 189
 190 static void acpi_timer_check_state(int state, struct acpi_processor *pr,
 191                                    struct acpi_processor_cx *cstate) { }
 192 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
 193 static void acpi_state_timer_broadcast(struct acpi_processor *pr,
 194                                        struct acpi_processor_cx *cx,
 195                                        int broadcast)
 196 {
 197 }
 198
 199 #endif
 200
 201 /*
 202  * Suspend / resume control
 203  */
 204 static int acpi_idle_suspend;
 205
 206 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 207 {
 208         acpi_idle_suspend = 1;
 209         return 0;
 210 }
 211
 212 int acpi_processor_resume(struct acpi_device * device)
 213 {
 214         acpi_idle_suspend = 0;
 215         return 0;
 216 }
 217
 218 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 219 static int tsc_halts_in_c(int state)
 220 {
 221         switch (boot_cpu_data.x86_vendor) {
 222         case X86_VENDOR_AMD:
 223         case X86_VENDOR_INTEL:
 224                 /*
 225                  * AMD Fam10h TSC will tick in all
 226                  * C/P/S0/S1 states when this bit is set.
 227                  */
 228                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 229                         return 0;
 230
 231                 /*FALL THROUGH*/
 232         default:
 233                 return state > ACPI_STATE_C1;
 234         }
 235 }
 236 #endif
 237
 238 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 239 {
 240
 241         if (!pr)
 242                 return -EINVAL;
 243
 244         if (!pr->pblk)
 245                 return -ENODEV;
 246
 247         /* if info is obtained from pblk/fadt, type equals state */
 248         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 249         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 250
 251 #ifndef CONFIG_HOTPLUG_CPU
 252         /*
 253          * Check for P_LVL2_UP flag before entering C2 and above on
 254          * an SMP system.
 255          */
 256         if ((num_online_cpus() > 1) &&
 257             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 258                 return -ENODEV;
 259 #endif
 260
 261         /* determine C2 and C3 address from pblk */
 262         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 263         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 264
 265         /* determine latencies from FADT */
 266         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 267         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 268
 269         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 270                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 271                           pr->power.states[ACPI_STATE_C2].address,
 272                           pr->power.states[ACPI_STATE_C3].address));
 273
 274         return 0;
 275 }
 276
 277 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 278 {
 279         if (!pr->power.states[ACPI_STATE_C1].valid) {
 280                 /* set the first C-State to C1 */
 281                 /* all processors need to support C1 */
 282                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 283                 pr->power.states[ACPI_STATE_C1].valid = 1;
 284                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 285         }
 286         /* the C0 state only exists as a filler in our array */
 287         pr->power.states[ACPI_STATE_C0].valid = 1;
 288         return 0;
 289 }
 290
 291 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 292 {
 293         acpi_status status = 0;
 294         acpi_integer count;
 295         int current_count;
 296         int i;
 297         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 298         union acpi_object *cst;
 299
 300
 301         if (nocst)
 302                 return -ENODEV;
 303
 304         current_count = 0;
 305
 306         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 307         if (ACPI_FAILURE(status)) {
 308                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 309                 return -ENODEV;
 310         }
 311
 312         cst = buffer.pointer;
 313
 314         /* There must be at least 2 elements */
 315         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 316                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 317                 status = -EFAULT;
 318                 goto end;
 319         }
 320
 321         count = cst->package.elements[0].integer.value;
 322
 323         /* Validate number of power states. */
 324         if (count < 1 || count != cst->package.count - 1) {
 325                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 326                 status = -EFAULT;
 327                 goto end;
 328         }
 329
 330         /* Tell driver that at least _CST is supported. */
 331         pr->flags.has_cst = 1;
 332
 333         for (i = 1; i <= count; i++) {
 334                 union acpi_object *element;
 335                 union acpi_object *obj;
 336                 struct acpi_power_register *reg;
 337                 struct acpi_processor_cx cx;
 338
 339                 memset(&cx, 0, sizeof(cx));
 340
 341                 element = &(cst->package.elements[i]);
 342                 if (element->type != ACPI_TYPE_PACKAGE)
 343                         continue;
 344
 345                 if (element->package.count != 4)
 346                         continue;
 347
 348                 obj = &(element->package.elements[0]);
 349
 350                 if (obj->type != ACPI_TYPE_BUFFER)
 351                         continue;
 352
 353                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 354
 355                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 356                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 357                         continue;
 358
 359                 /* There should be an easy way to extract an integer... */
 360                 obj = &(element->package.elements[1]);
 361                 if (obj->type != ACPI_TYPE_INTEGER)
 362                         continue;
 363
 364                 cx.type = obj->integer.value;
 365                 /*
 366                  * Some buggy BIOSes won't list C1 in _CST -
 367                  * Let acpi_processor_get_power_info_default() handle them later
 368                  */
 369                 if (i == 1 && cx.type != ACPI_STATE_C1)
 370                         current_count++;
 371
 372                 cx.address = reg->address;
 373                 cx.index = current_count + 1;
 374
 375                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 376                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 377                         if (acpi_processor_ffh_cstate_probe
 378                                         (pr->id, &cx, reg) == 0) {
 379                                 cx.entry_method = ACPI_CSTATE_FFH;
 380                         } else if (cx.type == ACPI_STATE_C1) {
 381                                 /*
 382                                  * C1 is a special case where FIXED_HARDWARE
 383                                  * can be handled in non-MWAIT way as well.
 384                                  * In that case, save this _CST entry info.
 385                                  * Otherwise, ignore this info and continue.
 386                                  */
 387                                 cx.entry_method = ACPI_CSTATE_HALT;
 388                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 389                         } else {
 390                                 continue;
 391                         }
 392                         if (cx.type == ACPI_STATE_C1 &&
 393                                         (idle_halt || idle_nomwait)) {
 394                                 /*
 395                                  * In most cases the C1 space_id obtained from
 396                                  * _CST object is FIXED_HARDWARE access mode.
 397                                  * But when the option of idle=halt is added,
 398                                  * the entry_method type should be changed from
 399                                  * CSTATE_FFH to CSTATE_HALT.
 400                                  * When the option of idle=nomwait is added,
 401                                  * the C1 entry_method type should be
 402                                  * CSTATE_HALT.
 403                                  */
 404                                 cx.entry_method = ACPI_CSTATE_HALT;
 405                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 406                         }
 407                 } else {
 408                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 409                                  cx.address);
 410                 }
 411
 412                 if (cx.type == ACPI_STATE_C1) {
 413                         cx.valid = 1;
 414                 }
 415
 416                 obj = &(element->package.elements[2]);
 417                 if (obj->type != ACPI_TYPE_INTEGER)
 418                         continue;
 419
 420                 cx.latency = obj->integer.value;
 421
 422                 obj = &(element->package.elements[3]);
 423                 if (obj->type != ACPI_TYPE_INTEGER)
 424                         continue;
 425
 426                 cx.power = obj->integer.value;
 427
 428                 current_count++;
 429                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 430
 431                 /*
 432                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 433                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 434                  */
 435                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 436                         printk(KERN_WARNING
 437                                "Limiting number of power states to max (%d)\n",
 438                                ACPI_PROCESSOR_MAX_POWER);
 439                         printk(KERN_WARNING
 440                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 441                         break;
 442                 }
 443         }
 444
 445         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 446                           current_count));
 447
 448         /* Validate number of power states discovered */
 449         if (current_count < 2)
 450                 status = -EFAULT;
 451
 452       end:
 453         kfree(buffer.pointer);
 454
 455         return status;
 456 }
 457
 458 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 459 {
 460
 461         if (!cx->address)
 462                 return;
 463
 464         /*
 465          * C2 latency must be less than or equal to 100
 466          * microseconds.
 467          */
 468         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 469                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 470                                   "latency too large [%d]\n", cx->latency));
 471                 return;
 472         }
 473
 474         /*
 475          * Otherwise we've met all of our C2 requirements.
 476          * Normalize the C2 latency to expidite policy
 477          */
 478         cx->valid = 1;
 479
 480         cx->latency_ticks = cx->latency;
 481
 482         return;
 483 }
 484
 485 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 486                                            struct acpi_processor_cx *cx)
 487 {
 488         static int bm_check_flag;
 489
 490
 491         if (!cx->address)
 492                 return;
 493
 494         /*
 495          * C3 latency must be less than or equal to 1000
 496          * microseconds.
 497          */
 498         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 499                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 500                                   "latency too large [%d]\n", cx->latency));
 501                 return;
 502         }
 503
 504         /*
 505          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 506          * DMA transfers are used by any ISA device to avoid livelock.
 507          * Note that we could disable Type-F DMA (as recommended by
 508          * the erratum), but this is known to disrupt certain ISA
 509          * devices thus we take the conservative approach.
 510          */
 511         else if (errata.piix4.fdma) {
 512                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 513                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 514                 return;
 515         }
 516
 517         /* All the logic here assumes flags.bm_check is same across all CPUs */
 518         if (!bm_check_flag) {
 519                 /* Determine whether bm_check is needed based on CPU  */
 520                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 521                 bm_check_flag = pr->flags.bm_check;
 522         } else {
 523                 pr->flags.bm_check = bm_check_flag;
 524         }
 525
 526         if (pr->flags.bm_check) {
 527                 if (!pr->flags.bm_control) {
 528                         if (pr->flags.has_cst != 1) {
 529                                 /* bus mastering control is necessary */
 530                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 531                                         "C3 support requires BM control\n"));
 532                                 return;
 533                         } else {
 534                                 /* Here we enter C3 without bus mastering */
 535                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 536                                         "C3 support without BM control\n"));
 537                         }
 538                 }
 539         } else {
 540                 /*
 541                  * WBINVD should be set in fadt, for C3 state to be
 542                  * supported on when bm_check is not required.
 543                  */
 544                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 545                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 546                                           "Cache invalidation should work properly"
 547                                           " for C3 to be enabled on SMP systems\n"));
 548                         return;
 549                 }
 550         }
 551
 552         /*
 553          * Otherwise we've met all of our C3 requirements.
 554          * Normalize the C3 latency to expidite policy.  Enable
 555          * checking of bus mastering status (bm_check) so we can
 556          * use this in our C3 policy
 557          */
 558         cx->valid = 1;
 559
 560         cx->latency_ticks = cx->latency;
 561         /*
 562          * On older chipsets, BM_RLD needs to be set
 563          * in order for Bus Master activity to wake the
 564          * system from C3.  Newer chipsets handle DMA
 565          * during C3 automatically and BM_RLD is a NOP.
 566          * In either case, the proper way to
 567          * handle BM_RLD is to set it and leave it set.
 568          */
 569         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 570
 571         return;
 572 }
 573
 574 static int acpi_processor_power_verify(struct acpi_processor *pr)
 575 {
 576         unsigned int i;
 577         unsigned int working = 0;
 578
 579         pr->power.timer_broadcast_on_state = INT_MAX;
 580
 581         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 582                 struct acpi_processor_cx *cx = &pr->power.states[i];
 583
 584 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 585                 /* TSC could halt in idle, so notify users */
 586                 if (tsc_halts_in_c(cx->type))
 587                         mark_tsc_unstable("TSC halts in idle");;
 588 #endif
 589                 switch (cx->type) {
 590                 case ACPI_STATE_C1:
 591                         cx->valid = 1;
 592                         break;
 593
 594                 case ACPI_STATE_C2:
 595                         acpi_processor_power_verify_c2(cx);
 596                         if (cx->valid)
 597                                 acpi_timer_check_state(i, pr, cx);
 598                         break;
 599
 600                 case ACPI_STATE_C3:
 601                         acpi_processor_power_verify_c3(pr, cx);
 602                         if (cx->valid)
 603                                 acpi_timer_check_state(i, pr, cx);
 604                         break;
 605                 }
 606
 607                 if (cx->valid)
 608                         working++;
 609         }
 610
 611         acpi_propagate_timer_broadcast(pr);
 612
 613         return (working);
 614 }
 615
 616 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 617 {
 618         unsigned int i;
 619         int result;
 620
 621
 622         /* NOTE: the idle thread may not be running while calling
 623          * this function */
 624
 625         /* Zero initialize all the C-states info. */
 626         memset(pr->power.states, 0, sizeof(pr->power.states));
 627
 628         result = acpi_processor_get_power_info_cst(pr);
 629         if (result == -ENODEV)
 630                 result = acpi_processor_get_power_info_fadt(pr);
 631
 632         if (result)
 633                 return result;
 634
 635         acpi_processor_get_power_info_default(pr);
 636
 637         pr->power.count = acpi_processor_power_verify(pr);
 638
 639         /*
 640          * if one state of type C2 or C3 is available, mark this
 641          * CPU as being "idle manageable"
 642          */
 643         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 644                 if (pr->power.states[i].valid) {
 645                         pr->power.count = i;
 646                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 647                                 pr->flags.power = 1;
 648                 }
 649         }
 650
 651         return 0;
 652 }
 653
 654 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 655 {
 656         struct acpi_processor *pr = seq->private;
 657         unsigned int i;
 658
 659
 660         if (!pr)
 661                 goto end;
 662
 663         seq_printf(seq, "active state:            C%zd\n"
 664                    "max_cstate:              C%d\n"
 665                    "bus master activity:     %08x\n"
 666                    "maximum allowed latency: %d usec\n",
 667                    pr->power.state ? pr->power.state - pr->power.states : 0,
 668                    max_cstate, (unsigned)pr->power.bm_activity,
 669                    pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
 670
 671         seq_puts(seq, "states:\n");
 672
 673         for (i = 1; i <= pr->power.count; i++) {
 674                 seq_printf(seq, "   %cC%d:                  ",
 675                            (&pr->power.states[i] ==
 676                             pr->power.state ? '*' : ' '), i);
 677
 678                 if (!pr->power.states[i].valid) {
 679                         seq_puts(seq, "<not supported>\n");
 680                         continue;
 681                 }
 682
 683                 switch (pr->power.states[i].type) {
 684                 case ACPI_STATE_C1:
 685                         seq_printf(seq, "type[C1] ");
 686                         break;
 687                 case ACPI_STATE_C2:
 688                         seq_printf(seq, "type[C2] ");
 689                         break;
 690                 case ACPI_STATE_C3:
 691                         seq_printf(seq, "type[C3] ");
 692                         break;
 693                 default:
 694                         seq_printf(seq, "type[--] ");
 695                         break;
 696                 }
 697
 698                 if (pr->power.states[i].promotion.state)
 699                         seq_printf(seq, "promotion[C%zd] ",
 700                                    (pr->power.states[i].promotion.state -
 701                                     pr->power.states));
 702                 else
 703                         seq_puts(seq, "promotion[--] ");
 704
 705                 if (pr->power.states[i].demotion.state)
 706                         seq_printf(seq, "demotion[C%zd] ",
 707                                    (pr->power.states[i].demotion.state -
 708                                     pr->power.states));
 709                 else
 710                         seq_puts(seq, "demotion[--] ");
 711
 712                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
 713                            pr->power.states[i].latency,
 714                            pr->power.states[i].usage,
 715                            (unsigned long long)pr->power.states[i].time);
 716         }
 717
 718       end:
 719         return 0;
 720 }
 721
 722 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 723 {
 724         return single_open(file, acpi_processor_power_seq_show,
 725                            PDE(inode)->data);
 726 }
 727
 728 static const struct file_operations acpi_processor_power_fops = {
 729         .owner = THIS_MODULE,
 730         .open = acpi_processor_power_open_fs,
 731         .read = seq_read,
 732         .llseek = seq_lseek,
 733         .release = single_release,
 734 };
 735
 736
 737 /**
 738  * acpi_idle_bm_check - checks if bus master activity was detected
 739  */
 740 static int acpi_idle_bm_check(void)
 741 {
 742         u32 bm_status = 0;
 743
 744         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 745         if (bm_status)
 746                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 747         /*
 748          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 749          * the true state of bus mastering activity; forcing us to
 750          * manually check the BMIDEA bit of each IDE channel.
 751          */
 752         else if (errata.piix4.bmisx) {
 753                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 754                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 755                         bm_status = 1;
 756         }
 757         return bm_status;
 758 }
 759
 760 /**
 761  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 762  * @cx: cstate data
 763  *
 764  * Caller disables interrupt before call and enables interrupt after return.
 765  */
 766 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 767 {
 768         /* Don't trace irqs off for idle */
 769         stop_critical_timings();
 770         if (cx->entry_method == ACPI_CSTATE_FFH) {
 771                 /* Call into architectural FFH based C-state */
 772                 acpi_processor_ffh_cstate_enter(cx);
 773         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 774                 acpi_safe_halt();
 775         } else {
 776                 int unused;
 777                 /* IO port based C-state */
 778                 inb(cx->address);
 779                 /* Dummy wait op - must do something useless after P_LVL2 read
 780                    because chipsets cannot guarantee that STPCLK# signal
 781                    gets asserted in time to freeze execution properly. */
 782                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 783         }
 784         start_critical_timings();
 785 }
 786
 787 /**
 788  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 789  * @dev: the target CPU
 790  * @state: the state data
 791  *
 792  * This is equivalent to the HALT instruction.
 793  */
 794 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 795                               struct cpuidle_state *state)
 796 {
 797         ktime_t  kt1, kt2;
 798         s64 idle_time;
 799         struct acpi_processor *pr;
 800         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 801
 802         pr = __get_cpu_var(processors);
 803
 804         if (unlikely(!pr))
 805                 return 0;
 806
 807         local_irq_disable();
 808
 809         /* Do not access any ACPI IO ports in suspend path */
 810         if (acpi_idle_suspend) {
 811                 acpi_safe_halt();
 812                 local_irq_enable();
 813                 return 0;
 814         }
 815
 816         kt1 = ktime_get_real();
 817         acpi_idle_do_entry(cx);
 818         kt2 = ktime_get_real();
 819         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 820
 821         local_irq_enable();
 822         cx->usage++;
 823
 824         return idle_time;
 825 }
 826
 827 /**
 828  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 829  * @dev: the target CPU
 830  * @state: the state data
 831  */
 832 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 833                                   struct cpuidle_state *state)
 834 {
 835         struct acpi_processor *pr;
 836         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 837         ktime_t  kt1, kt2;
 838         s64 idle_time;
 839         s64 sleep_ticks = 0;
 840
 841         pr = __get_cpu_var(processors);
 842
 843         if (unlikely(!pr))
 844                 return 0;
 845
 846         if (acpi_idle_suspend)
 847                 return(acpi_idle_enter_c1(dev, state));
 848
 849         local_irq_disable();
 850         current_thread_info()->status &= ~TS_POLLING;
 851         /*
 852          * TS_POLLING-cleared state must be visible before we test
 853          * NEED_RESCHED:
 854          */
 855         smp_mb();
 856
 857         if (unlikely(need_resched())) {
 858                 current_thread_info()->status |= TS_POLLING;
 859                 local_irq_enable();
 860                 return 0;
 861         }
 862
 863         /*
 864          * Must be done before busmaster disable as we might need to
 865          * access HPET !
 866          */
 867         acpi_state_timer_broadcast(pr, cx, 1);
 868
 869         if (cx->type == ACPI_STATE_C3)
 870                 ACPI_FLUSH_CPU_CACHE();
 871
 872         kt1 = ktime_get_real();
 873         /* Tell the scheduler that we are going deep-idle: */
 874         sched_clock_idle_sleep_event();
 875         acpi_idle_do_entry(cx);
 876         kt2 = ktime_get_real();
 877         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 878
 879         sleep_ticks = us_to_pm_timer_ticks(idle_time);
 880
 881         /* Tell the scheduler how much we idled: */
 882         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 883
 884         local_irq_enable();
 885         current_thread_info()->status |= TS_POLLING;
 886
 887         cx->usage++;
 888
 889         acpi_state_timer_broadcast(pr, cx, 0);
 890         cx->time += sleep_ticks;
 891         return idle_time;
 892 }
 893
 894 static int c3_cpu_count;
 895 static DEFINE_SPINLOCK(c3_lock);
 896
 897 /**
 898  * acpi_idle_enter_bm - enters C3 with proper BM handling
 899  * @dev: the target CPU
 900  * @state: the state data
 901  *
 902  * If BM is detected, the deepest non-C3 idle state is entered instead.
 903  */
 904 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 905                               struct cpuidle_state *state)
 906 {
 907         struct acpi_processor *pr;
 908         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 909         ktime_t  kt1, kt2;
 910         s64 idle_time;
 911         s64 sleep_ticks = 0;
 912
 913
 914         pr = __get_cpu_var(processors);
 915
 916         if (unlikely(!pr))
 917                 return 0;
 918
 919         if (acpi_idle_suspend)
 920                 return(acpi_idle_enter_c1(dev, state));
 921
 922         if (acpi_idle_bm_check()) {
 923                 if (dev->safe_state) {
 924                         dev->last_state = dev->safe_state;
 925                         return dev->safe_state->enter(dev, dev->safe_state);
 926                 } else {
 927                         local_irq_disable();
 928                         acpi_safe_halt();
 929                         local_irq_enable();
 930                         return 0;
 931                 }
 932         }
 933
 934         local_irq_disable();
 935         current_thread_info()->status &= ~TS_POLLING;
 936         /*
 937          * TS_POLLING-cleared state must be visible before we test
 938          * NEED_RESCHED:
 939          */
 940         smp_mb();
 941
 942         if (unlikely(need_resched())) {
 943                 current_thread_info()->status |= TS_POLLING;
 944                 local_irq_enable();
 945                 return 0;
 946         }
 947
 948         acpi_unlazy_tlb(smp_processor_id());
 949
 950         /* Tell the scheduler that we are going deep-idle: */
 951         sched_clock_idle_sleep_event();
 952         /*
 953          * Must be done before busmaster disable as we might need to
 954          * access HPET !
 955          */
 956         acpi_state_timer_broadcast(pr, cx, 1);
 957
 958         /*
 959          * disable bus master
 960          * bm_check implies we need ARB_DIS
 961          * !bm_check implies we need cache flush
 962          * bm_control implies whether we can do ARB_DIS
 963          *
 964          * That leaves a case where bm_check is set and bm_control is
 965          * not set. In that case we cannot do much, we enter C3
 966          * without doing anything.
 967          */
 968         if (pr->flags.bm_check && pr->flags.bm_control) {
 969                 spin_lock(&c3_lock);
 970                 c3_cpu_count++;
 971                 /* Disable bus master arbitration when all CPUs are in C3 */
 972                 if (c3_cpu_count == num_online_cpus())
 973                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 974                 spin_unlock(&c3_lock);
 975         } else if (!pr->flags.bm_check) {
 976                 ACPI_FLUSH_CPU_CACHE();
 977         }
 978
 979         kt1 = ktime_get_real();
 980         acpi_idle_do_entry(cx);
 981         kt2 = ktime_get_real();
 982         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 983
 984         /* Re-enable bus master arbitration */
 985         if (pr->flags.bm_check && pr->flags.bm_control) {
 986                 spin_lock(&c3_lock);
 987                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 988                 c3_cpu_count--;
 989                 spin_unlock(&c3_lock);
 990         }
 991
 992         sleep_ticks = us_to_pm_timer_ticks(idle_time);
 993         /* Tell the scheduler how much we idled: */
 994         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 995
 996         local_irq_enable();
 997         current_thread_info()->status |= TS_POLLING;
 998
 999         cx->usage++;
1000
1001         acpi_state_timer_broadcast(pr, cx, 0);
1002         cx->time += sleep_ticks;
1003         return idle_time;
1004 }
1005
1006 struct cpuidle_driver acpi_idle_driver = {
1007         .name =         "acpi_idle",
1008         .owner =        THIS_MODULE,
1009 };
1010
1011 /**
1012  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1013  * @pr: the ACPI processor
1014  */
1015 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1016 {
1017         int i, count = CPUIDLE_DRIVER_STATE_START;
1018         struct acpi_processor_cx *cx;
1019         struct cpuidle_state *state;
1020         struct cpuidle_device *dev = &pr->power.dev;
1021
1022         if (!pr->flags.power_setup_done)
1023                 return -EINVAL;
1024
1025         if (pr->flags.power == 0) {
1026                 return -EINVAL;
1027         }
1028
1029         dev->cpu = pr->id;
1030         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1031                 dev->states[i].name[0] = '\0';
1032                 dev->states[i].desc[0] = '\0';
1033         }
1034
1035         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1036                 cx = &pr->power.states[i];
1037                 state = &dev->states[count];
1038
1039                 if (!cx->valid)
1040                         continue;
1041
1042 #ifdef CONFIG_HOTPLUG_CPU
1043                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1044                     !pr->flags.has_cst &&
1045                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1046                         continue;
1047 #endif
1048                 cpuidle_set_statedata(state, cx);
1049
1050                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1051                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1052                 state->exit_latency = cx->latency;
1053                 state->target_residency = cx->latency * latency_factor;
1054                 state->power_usage = cx->power;
1055
1056                 state->flags = 0;
1057                 switch (cx->type) {
1058                         case ACPI_STATE_C1:
1059                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1060                         if (cx->entry_method == ACPI_CSTATE_FFH)
1061                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1062
1063                         state->enter = acpi_idle_enter_c1;
1064                         dev->safe_state = state;
1065                         break;
1066
1067                         case ACPI_STATE_C2:
1068                         state->flags |= CPUIDLE_FLAG_BALANCED;
1069                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1070                         state->enter = acpi_idle_enter_simple;
1071                         dev->safe_state = state;
1072                         break;
1073
1074                         case ACPI_STATE_C3:
1075                         state->flags |= CPUIDLE_FLAG_DEEP;
1076                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1077                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1078                         state->enter = pr->flags.bm_check ?
1079                                         acpi_idle_enter_bm :
1080                                         acpi_idle_enter_simple;
1081                         break;
1082                 }
1083
1084                 count++;
1085                 if (count == CPUIDLE_STATE_MAX)
1086                         break;
1087         }
1088
1089         dev->state_count = count;
1090
1091         if (!count)
1092                 return -EINVAL;
1093
1094         return 0;
1095 }
1096
1097 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1098 {
1099         int ret = 0;
1100
1101         if (boot_option_idle_override)
1102                 return 0;
1103
1104         if (!pr)
1105                 return -EINVAL;
1106
1107         if (nocst) {
1108                 return -ENODEV;
1109         }
1110
1111         if (!pr->flags.power_setup_done)
1112                 return -ENODEV;
1113
1114         cpuidle_pause_and_lock();
1115         cpuidle_disable_device(&pr->power.dev);
1116         acpi_processor_get_power_info(pr);
1117         if (pr->flags.power) {
1118                 acpi_processor_setup_cpuidle(pr);
1119                 ret = cpuidle_enable_device(&pr->power.dev);
1120         }
1121         cpuidle_resume_and_unlock();
1122
1123         return ret;
1124 }
1125
1126 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1127                               struct acpi_device *device)
1128 {
1129         acpi_status status = 0;
1130         static int first_run;
1131         struct proc_dir_entry *entry = NULL;
1132         unsigned int i;
1133
1134         if (boot_option_idle_override)
1135                 return 0;
1136
1137         if (!first_run) {
1138                 if (idle_halt) {
1139                         /*
1140                          * When the boot option of "idle=halt" is added, halt
1141                          * is used for CPU IDLE.
1142                          * In such case C2/C3 is meaningless. So the max_cstate
1143                          * is set to one.
1144                          */
1145                         max_cstate = 1;
1146                 }
1147                 dmi_check_system(processor_power_dmi_table);
1148                 max_cstate = acpi_processor_cstate_check(max_cstate);
1149                 if (max_cstate < ACPI_C_STATES_MAX)
1150                         printk(KERN_NOTICE
1151                                "ACPI: processor limited to max C-state %d\n",
1152                                max_cstate);
1153                 first_run++;
1154         }
1155
1156         if (!pr)
1157                 return -EINVAL;
1158
1159         if (acpi_gbl_FADT.cst_control && !nocst) {
1160                 status =
1161                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1162                 if (ACPI_FAILURE(status)) {
1163                         ACPI_EXCEPTION((AE_INFO, status,
1164                                         "Notifying BIOS of _CST ability failed"));
1165                 }
1166         }
1167
1168         acpi_processor_get_power_info(pr);
1169         pr->flags.power_setup_done = 1;
1170
1171         /*
1172          * Install the idle handler if processor power management is supported.
1173          * Note that we use previously set idle handler will be used on
1174          * platforms that only support C1.
1175          */
1176         if (pr->flags.power) {
1177                 acpi_processor_setup_cpuidle(pr);
1178                 if (cpuidle_register_device(&pr->power.dev))
1179                         return -EIO;
1180
1181                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1182                 for (i = 1; i <= pr->power.count; i++)
1183                         if (pr->power.states[i].valid)
1184                                 printk(" C%d[C%d]", i,
1185                                        pr->power.states[i].type);
1186                 printk(")\n");
1187         }
1188
1189         /* 'power' [R] */
1190         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1191                                  S_IRUGO, acpi_device_dir(device),
1192                                  &acpi_processor_power_fops,
1193                                  acpi_driver_data(device));
1194         if (!entry)
1195                 return -EIO;
1196         return 0;
1197 }
1198
1199 int acpi_processor_power_exit(struct acpi_processor *pr,
1200                               struct acpi_device *device)
1201 {
1202         if (boot_option_idle_override)
1203                 return 0;
1204
1205         cpuidle_unregister_device(&pr->power.dev);
1206         pr->flags.power_setup_done = 0;
1207
1208         if (acpi_device_dir(device))
1209                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1210                                   acpi_device_dir(device));
1211
1212         return 0;
1213 }