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/module.h>
  32 #include <linux/acpi.h>
  33 #include <linux/dmi.h>
  34 #include <linux/sched.h>       /* need_resched() */
  35 #include <linux/clockchips.h>
  36 #include <linux/cpuidle.h>
  37 #include <linux/syscore_ops.h>
  38
  39 /*
  40  * Include the apic definitions for x86 to have the APIC timer related defines
  41  * available also for UP (on SMP it gets magically included via linux/smp.h).
  42  * asm/acpi.h is not an option, as it would require more include magic. Also
  43  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  44  */
  45 #ifdef CONFIG_X86
  46 #include <asm/apic.h>
  47 #endif
  48
  49 #include <acpi/acpi_bus.h>
  50 #include <acpi/processor.h>
  51
  52 #define PREFIX "ACPI: "
  53
  54 #define ACPI_PROCESSOR_CLASS            "processor"
  55 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  56 ACPI_MODULE_NAME("processor_idle");
  57
  58 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  59 module_param(max_cstate, uint, 0000);
  60 static unsigned int nocst __read_mostly;
  61 module_param(nocst, uint, 0000);
  62 static int bm_check_disable __read_mostly;
  63 module_param(bm_check_disable, uint, 0000);
  64
  65 static unsigned int latency_factor __read_mostly = 2;
  66 module_param(latency_factor, uint, 0644);
  67
  68 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  69
  70 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
  71                                                                 acpi_cstate);
  72
  73 static int disabled_by_idle_boot_param(void)
  74 {
  75         return boot_option_idle_override == IDLE_POLL ||
  76                 boot_option_idle_override == IDLE_HALT;
  77 }
  78
  79 /*
  80  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  81  * For now disable this. Probably a bug somewhere else.
  82  *
  83  * To skip this limit, boot/load with a large max_cstate limit.
  84  */
  85 static int set_max_cstate(const struct dmi_system_id *id)
  86 {
  87         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  88                 return 0;
  89
  90         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  91                " Override with \"processor.max_cstate=%d\"\n", id->ident,
  92                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  93
  94         max_cstate = (long)id->driver_data;
  95
  96         return 0;
  97 }
  98
  99 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 100    callers to only run once -AK */
 101 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 102         { set_max_cstate, "Clevo 5600D", {
 103           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 104           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 105          (void *)2},
 106         { set_max_cstate, "Pavilion zv5000", {
 107           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 108           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 109          (void *)1},
 110         { set_max_cstate, "Asus L8400B", {
 111           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 112           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 113          (void *)1},
 114         {},
 115 };
 116
 117
 118 /*
 119  * Callers should disable interrupts before the call and enable
 120  * interrupts after return.
 121  */
 122 static void acpi_safe_halt(void)
 123 {
 124         current_thread_info()->status &= ~TS_POLLING;
 125         /*
 126          * TS_POLLING-cleared state must be visible before we
 127          * test NEED_RESCHED:
 128          */
 129         smp_mb();
 130         if (!need_resched()) {
 131                 safe_halt();
 132                 local_irq_disable();
 133         }
 134         current_thread_info()->status |= TS_POLLING;
 135 }
 136
 137 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 138
 139 /*
 140  * Some BIOS implementations switch to C3 in the published C2 state.
 141  * This seems to be a common problem on AMD boxen, but other vendors
 142  * are affected too. We pick the most conservative approach: we assume
 143  * that the local APIC stops in both C2 and C3.
 144  */
 145 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 146                                    struct acpi_processor_cx *cx)
 147 {
 148         struct acpi_processor_power *pwr = &pr->power;
 149         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 150
 151         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 152                 return;
 153
 154         if (amd_e400_c1e_detected)
 155                 type = ACPI_STATE_C1;
 156
 157         /*
 158          * Check, if one of the previous states already marked the lapic
 159          * unstable
 160          */
 161         if (pwr->timer_broadcast_on_state < state)
 162                 return;
 163
 164         if (cx->type >= type)
 165                 pr->power.timer_broadcast_on_state = state;
 166 }
 167
 168 static void __lapic_timer_propagate_broadcast(void *arg)
 169 {
 170         struct acpi_processor *pr = (struct acpi_processor *) arg;
 171         unsigned long reason;
 172
 173         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 174                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 175
 176         clockevents_notify(reason, &pr->id);
 177 }
 178
 179 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 180 {
 181         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 182                                  (void *)pr, 1);
 183 }
 184
 185 /* Power(C) State timer broadcast control */
 186 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 187                                        struct acpi_processor_cx *cx,
 188                                        int broadcast)
 189 {
 190         int state = cx - pr->power.states;
 191
 192         if (state >= pr->power.timer_broadcast_on_state) {
 193                 unsigned long reason;
 194
 195                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 196                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 197                 clockevents_notify(reason, &pr->id);
 198         }
 199 }
 200
 201 #else
 202
 203 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 204                                    struct acpi_processor_cx *cstate) { }
 205 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 206 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 207                                        struct acpi_processor_cx *cx,
 208                                        int broadcast)
 209 {
 210 }
 211
 212 #endif
 213
 214 #ifdef CONFIG_PM_SLEEP
 215 static u32 saved_bm_rld;
 216
 217 int acpi_processor_suspend(void)
 218 {
 219         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 220         return 0;
 221 }
 222
 223 void acpi_processor_resume(void)
 224 {
 225         u32 resumed_bm_rld;
 226
 227         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 228         if (resumed_bm_rld == saved_bm_rld)
 229                 return;
 230
 231         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 232 }
 233
 234 static struct syscore_ops acpi_processor_syscore_ops = {
 235         .suspend = acpi_processor_suspend,
 236         .resume = acpi_processor_resume,
 237 };
 238
 239 void acpi_processor_syscore_init(void)
 240 {
 241         register_syscore_ops(&acpi_processor_syscore_ops);
 242 }
 243
 244 void acpi_processor_syscore_exit(void)
 245 {
 246         unregister_syscore_ops(&acpi_processor_syscore_ops);
 247 }
 248 #endif /* CONFIG_PM_SLEEP */
 249
 250 #if defined(CONFIG_X86)
 251 static void tsc_check_state(int state)
 252 {
 253         switch (boot_cpu_data.x86_vendor) {
 254         case X86_VENDOR_AMD:
 255         case X86_VENDOR_INTEL:
 256                 /*
 257                  * AMD Fam10h TSC will tick in all
 258                  * C/P/S0/S1 states when this bit is set.
 259                  */
 260                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 261                         return;
 262
 263                 /*FALL THROUGH*/
 264         default:
 265                 /* TSC could halt in idle, so notify users */
 266                 if (state > ACPI_STATE_C1)
 267                         mark_tsc_unstable("TSC halts in idle");
 268         }
 269 }
 270 #else
 271 static void tsc_check_state(int state) { return; }
 272 #endif
 273
 274 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 275 {
 276
 277         if (!pr)
 278                 return -EINVAL;
 279
 280         if (!pr->pblk)
 281                 return -ENODEV;
 282
 283         /* if info is obtained from pblk/fadt, type equals state */
 284         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 285         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 286
 287 #ifndef CONFIG_HOTPLUG_CPU
 288         /*
 289          * Check for P_LVL2_UP flag before entering C2 and above on
 290          * an SMP system.
 291          */
 292         if ((num_online_cpus() > 1) &&
 293             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 294                 return -ENODEV;
 295 #endif
 296
 297         /* determine C2 and C3 address from pblk */
 298         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 299         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 300
 301         /* determine latencies from FADT */
 302         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 303         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 304
 305         /*
 306          * FADT specified C2 latency must be less than or equal to
 307          * 100 microseconds.
 308          */
 309         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 310                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 311                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 312                 /* invalidate C2 */
 313                 pr->power.states[ACPI_STATE_C2].address = 0;
 314         }
 315
 316         /*
 317          * FADT supplied C3 latency must be less than or equal to
 318          * 1000 microseconds.
 319          */
 320         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 321                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 322                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 323                 /* invalidate C3 */
 324                 pr->power.states[ACPI_STATE_C3].address = 0;
 325         }
 326
 327         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 328                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 329                           pr->power.states[ACPI_STATE_C2].address,
 330                           pr->power.states[ACPI_STATE_C3].address));
 331
 332         return 0;
 333 }
 334
 335 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 336 {
 337         if (!pr->power.states[ACPI_STATE_C1].valid) {
 338                 /* set the first C-State to C1 */
 339                 /* all processors need to support C1 */
 340                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 341                 pr->power.states[ACPI_STATE_C1].valid = 1;
 342                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 343         }
 344         /* the C0 state only exists as a filler in our array */
 345         pr->power.states[ACPI_STATE_C0].valid = 1;
 346         return 0;
 347 }
 348
 349 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 350 {
 351         acpi_status status = 0;
 352         u64 count;
 353         int current_count;
 354         int i;
 355         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 356         union acpi_object *cst;
 357
 358
 359         if (nocst)
 360                 return -ENODEV;
 361
 362         current_count = 0;
 363
 364         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 365         if (ACPI_FAILURE(status)) {
 366                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 367                 return -ENODEV;
 368         }
 369
 370         cst = buffer.pointer;
 371
 372         /* There must be at least 2 elements */
 373         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 374                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 375                 status = -EFAULT;
 376                 goto end;
 377         }
 378
 379         count = cst->package.elements[0].integer.value;
 380
 381         /* Validate number of power states. */
 382         if (count < 1 || count != cst->package.count - 1) {
 383                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 384                 status = -EFAULT;
 385                 goto end;
 386         }
 387
 388         /* Tell driver that at least _CST is supported. */
 389         pr->flags.has_cst = 1;
 390
 391         for (i = 1; i <= count; i++) {
 392                 union acpi_object *element;
 393                 union acpi_object *obj;
 394                 struct acpi_power_register *reg;
 395                 struct acpi_processor_cx cx;
 396
 397                 memset(&cx, 0, sizeof(cx));
 398
 399                 element = &(cst->package.elements[i]);
 400                 if (element->type != ACPI_TYPE_PACKAGE)
 401                         continue;
 402
 403                 if (element->package.count != 4)
 404                         continue;
 405
 406                 obj = &(element->package.elements[0]);
 407
 408                 if (obj->type != ACPI_TYPE_BUFFER)
 409                         continue;
 410
 411                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 412
 413                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 414                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 415                         continue;
 416
 417                 /* There should be an easy way to extract an integer... */
 418                 obj = &(element->package.elements[1]);
 419                 if (obj->type != ACPI_TYPE_INTEGER)
 420                         continue;
 421
 422                 cx.type = obj->integer.value;
 423                 /*
 424                  * Some buggy BIOSes won't list C1 in _CST -
 425                  * Let acpi_processor_get_power_info_default() handle them later
 426                  */
 427                 if (i == 1 && cx.type != ACPI_STATE_C1)
 428                         current_count++;
 429
 430                 cx.address = reg->address;
 431                 cx.index = current_count + 1;
 432
 433                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 434                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 435                         if (acpi_processor_ffh_cstate_probe
 436                                         (pr->id, &cx, reg) == 0) {
 437                                 cx.entry_method = ACPI_CSTATE_FFH;
 438                         } else if (cx.type == ACPI_STATE_C1) {
 439                                 /*
 440                                  * C1 is a special case where FIXED_HARDWARE
 441                                  * can be handled in non-MWAIT way as well.
 442                                  * In that case, save this _CST entry info.
 443                                  * Otherwise, ignore this info and continue.
 444                                  */
 445                                 cx.entry_method = ACPI_CSTATE_HALT;
 446                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 447                         } else {
 448                                 continue;
 449                         }
 450                         if (cx.type == ACPI_STATE_C1 &&
 451                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 452                                 /*
 453                                  * In most cases the C1 space_id obtained from
 454                                  * _CST object is FIXED_HARDWARE access mode.
 455                                  * But when the option of idle=halt is added,
 456                                  * the entry_method type should be changed from
 457                                  * CSTATE_FFH to CSTATE_HALT.
 458                                  * When the option of idle=nomwait is added,
 459                                  * the C1 entry_method type should be
 460                                  * CSTATE_HALT.
 461                                  */
 462                                 cx.entry_method = ACPI_CSTATE_HALT;
 463                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 464                         }
 465                 } else {
 466                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 467                                  cx.address);
 468                 }
 469
 470                 if (cx.type == ACPI_STATE_C1) {
 471                         cx.valid = 1;
 472                 }
 473
 474                 obj = &(element->package.elements[2]);
 475                 if (obj->type != ACPI_TYPE_INTEGER)
 476                         continue;
 477
 478                 cx.latency = obj->integer.value;
 479
 480                 obj = &(element->package.elements[3]);
 481                 if (obj->type != ACPI_TYPE_INTEGER)
 482                         continue;
 483
 484                 current_count++;
 485                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 486
 487                 /*
 488                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 489                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 490                  */
 491                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 492                         printk(KERN_WARNING
 493                                "Limiting number of power states to max (%d)\n",
 494                                ACPI_PROCESSOR_MAX_POWER);
 495                         printk(KERN_WARNING
 496                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 497                         break;
 498                 }
 499         }
 500
 501         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 502                           current_count));
 503
 504         /* Validate number of power states discovered */
 505         if (current_count < 2)
 506                 status = -EFAULT;
 507
 508       end:
 509         kfree(buffer.pointer);
 510
 511         return status;
 512 }
 513
 514 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 515                                            struct acpi_processor_cx *cx)
 516 {
 517         static int bm_check_flag = -1;
 518         static int bm_control_flag = -1;
 519
 520
 521         if (!cx->address)
 522                 return;
 523
 524         /*
 525          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 526          * DMA transfers are used by any ISA device to avoid livelock.
 527          * Note that we could disable Type-F DMA (as recommended by
 528          * the erratum), but this is known to disrupt certain ISA
 529          * devices thus we take the conservative approach.
 530          */
 531         else if (errata.piix4.fdma) {
 532                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 533                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 534                 return;
 535         }
 536
 537         /* All the logic here assumes flags.bm_check is same across all CPUs */
 538         if (bm_check_flag == -1) {
 539                 /* Determine whether bm_check is needed based on CPU  */
 540                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 541                 bm_check_flag = pr->flags.bm_check;
 542                 bm_control_flag = pr->flags.bm_control;
 543         } else {
 544                 pr->flags.bm_check = bm_check_flag;
 545                 pr->flags.bm_control = bm_control_flag;
 546         }
 547
 548         if (pr->flags.bm_check) {
 549                 if (!pr->flags.bm_control) {
 550                         if (pr->flags.has_cst != 1) {
 551                                 /* bus mastering control is necessary */
 552                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 553                                         "C3 support requires BM control\n"));
 554                                 return;
 555                         } else {
 556                                 /* Here we enter C3 without bus mastering */
 557                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 558                                         "C3 support without BM control\n"));
 559                         }
 560                 }
 561         } else {
 562                 /*
 563                  * WBINVD should be set in fadt, for C3 state to be
 564                  * supported on when bm_check is not required.
 565                  */
 566                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 567                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 568                                           "Cache invalidation should work properly"
 569                                           " for C3 to be enabled on SMP systems\n"));
 570                         return;
 571                 }
 572         }
 573
 574         /*
 575          * Otherwise we've met all of our C3 requirements.
 576          * Normalize the C3 latency to expidite policy.  Enable
 577          * checking of bus mastering status (bm_check) so we can
 578          * use this in our C3 policy
 579          */
 580         cx->valid = 1;
 581
 582         /*
 583          * On older chipsets, BM_RLD needs to be set
 584          * in order for Bus Master activity to wake the
 585          * system from C3.  Newer chipsets handle DMA
 586          * during C3 automatically and BM_RLD is a NOP.
 587          * In either case, the proper way to
 588          * handle BM_RLD is to set it and leave it set.
 589          */
 590         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 591
 592         return;
 593 }
 594
 595 static int acpi_processor_power_verify(struct acpi_processor *pr)
 596 {
 597         unsigned int i;
 598         unsigned int working = 0;
 599
 600         pr->power.timer_broadcast_on_state = INT_MAX;
 601
 602         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 603                 struct acpi_processor_cx *cx = &pr->power.states[i];
 604
 605                 switch (cx->type) {
 606                 case ACPI_STATE_C1:
 607                         cx->valid = 1;
 608                         break;
 609
 610                 case ACPI_STATE_C2:
 611                         if (!cx->address)
 612                                 break;
 613                         cx->valid = 1;
 614                         break;
 615
 616                 case ACPI_STATE_C3:
 617                         acpi_processor_power_verify_c3(pr, cx);
 618                         break;
 619                 }
 620                 if (!cx->valid)
 621                         continue;
 622
 623                 lapic_timer_check_state(i, pr, cx);
 624                 tsc_check_state(cx->type);
 625                 working++;
 626         }
 627
 628         lapic_timer_propagate_broadcast(pr);
 629
 630         return (working);
 631 }
 632
 633 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 634 {
 635         unsigned int i;
 636         int result;
 637
 638
 639         /* NOTE: the idle thread may not be running while calling
 640          * this function */
 641
 642         /* Zero initialize all the C-states info. */
 643         memset(pr->power.states, 0, sizeof(pr->power.states));
 644
 645         result = acpi_processor_get_power_info_cst(pr);
 646         if (result == -ENODEV)
 647                 result = acpi_processor_get_power_info_fadt(pr);
 648
 649         if (result)
 650                 return result;
 651
 652         acpi_processor_get_power_info_default(pr);
 653
 654         pr->power.count = acpi_processor_power_verify(pr);
 655
 656         /*
 657          * if one state of type C2 or C3 is available, mark this
 658          * CPU as being "idle manageable"
 659          */
 660         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 661                 if (pr->power.states[i].valid) {
 662                         pr->power.count = i;
 663                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 664                                 pr->flags.power = 1;
 665                 }
 666         }
 667
 668         return 0;
 669 }
 670
 671 /**
 672  * acpi_idle_bm_check - checks if bus master activity was detected
 673  */
 674 static int acpi_idle_bm_check(void)
 675 {
 676         u32 bm_status = 0;
 677
 678         if (bm_check_disable)
 679                 return 0;
 680
 681         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 682         if (bm_status)
 683                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 684         /*
 685          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 686          * the true state of bus mastering activity; forcing us to
 687          * manually check the BMIDEA bit of each IDE channel.
 688          */
 689         else if (errata.piix4.bmisx) {
 690                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 691                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 692                         bm_status = 1;
 693         }
 694         return bm_status;
 695 }
 696
 697 /**
 698  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 699  * @cx: cstate data
 700  *
 701  * Caller disables interrupt before call and enables interrupt after return.
 702  */
 703 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 704 {
 705         /* Don't trace irqs off for idle */
 706         stop_critical_timings();
 707         if (cx->entry_method == ACPI_CSTATE_FFH) {
 708                 /* Call into architectural FFH based C-state */
 709                 acpi_processor_ffh_cstate_enter(cx);
 710         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 711                 acpi_safe_halt();
 712         } else {
 713                 /* IO port based C-state */
 714                 inb(cx->address);
 715                 /* Dummy wait op - must do something useless after P_LVL2 read
 716                    because chipsets cannot guarantee that STPCLK# signal
 717                    gets asserted in time to freeze execution properly. */
 718                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 719         }
 720         start_critical_timings();
 721 }
 722
 723 /**
 724  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 725  * @dev: the target CPU
 726  * @drv: cpuidle driver containing cpuidle state info
 727  * @index: index of target state
 728  *
 729  * This is equivalent to the HALT instruction.
 730  */
 731 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 732                 struct cpuidle_driver *drv, int index)
 733 {
 734         struct acpi_processor *pr;
 735         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 736
 737         pr = __this_cpu_read(processors);
 738
 739         if (unlikely(!pr))
 740                 return -EINVAL;
 741
 742         lapic_timer_state_broadcast(pr, cx, 1);
 743         acpi_idle_do_entry(cx);
 744
 745         lapic_timer_state_broadcast(pr, cx, 0);
 746
 747         return index;
 748 }
 749
 750
 751 /**
 752  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 753  * @dev: the target CPU
 754  * @index: the index of suggested state
 755  */
 756 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 757 {
 758         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 759
 760         ACPI_FLUSH_CPU_CACHE();
 761
 762         while (1) {
 763
 764                 if (cx->entry_method == ACPI_CSTATE_HALT)
 765                         safe_halt();
 766                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 767                         inb(cx->address);
 768                         /* See comment in acpi_idle_do_entry() */
 769                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 770                 } else
 771                         return -ENODEV;
 772         }
 773
 774         /* Never reached */
 775         return 0;
 776 }
 777
 778 /**
 779  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 780  * @dev: the target CPU
 781  * @drv: cpuidle driver with cpuidle state information
 782  * @index: the index of suggested state
 783  */
 784 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 785                 struct cpuidle_driver *drv, int index)
 786 {
 787         struct acpi_processor *pr;
 788         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 789
 790         pr = __this_cpu_read(processors);
 791
 792         if (unlikely(!pr))
 793                 return -EINVAL;
 794
 795         if (cx->entry_method != ACPI_CSTATE_FFH) {
 796                 current_thread_info()->status &= ~TS_POLLING;
 797                 /*
 798                  * TS_POLLING-cleared state must be visible before we test
 799                  * NEED_RESCHED:
 800                  */
 801                 smp_mb();
 802
 803                 if (unlikely(need_resched())) {
 804                         current_thread_info()->status |= TS_POLLING;
 805                         return -EINVAL;
 806                 }
 807         }
 808
 809         /*
 810          * Must be done before busmaster disable as we might need to
 811          * access HPET !
 812          */
 813         lapic_timer_state_broadcast(pr, cx, 1);
 814
 815         if (cx->type == ACPI_STATE_C3)
 816                 ACPI_FLUSH_CPU_CACHE();
 817
 818         /* Tell the scheduler that we are going deep-idle: */
 819         sched_clock_idle_sleep_event();
 820         acpi_idle_do_entry(cx);
 821
 822         sched_clock_idle_wakeup_event(0);
 823
 824         if (cx->entry_method != ACPI_CSTATE_FFH)
 825                 current_thread_info()->status |= TS_POLLING;
 826
 827         lapic_timer_state_broadcast(pr, cx, 0);
 828         return index;
 829 }
 830
 831 static int c3_cpu_count;
 832 static DEFINE_RAW_SPINLOCK(c3_lock);
 833
 834 /**
 835  * acpi_idle_enter_bm - enters C3 with proper BM handling
 836  * @dev: the target CPU
 837  * @drv: cpuidle driver containing state data
 838  * @index: the index of suggested state
 839  *
 840  * If BM is detected, the deepest non-C3 idle state is entered instead.
 841  */
 842 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 843                 struct cpuidle_driver *drv, int index)
 844 {
 845         struct acpi_processor *pr;
 846         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 847
 848         pr = __this_cpu_read(processors);
 849
 850         if (unlikely(!pr))
 851                 return -EINVAL;
 852
 853         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 854                 if (drv->safe_state_index >= 0) {
 855                         return drv->states[drv->safe_state_index].enter(dev,
 856                                                 drv, drv->safe_state_index);
 857                 } else {
 858                         acpi_safe_halt();
 859                         return -EBUSY;
 860                 }
 861         }
 862
 863         if (cx->entry_method != ACPI_CSTATE_FFH) {
 864                 current_thread_info()->status &= ~TS_POLLING;
 865                 /*
 866                  * TS_POLLING-cleared state must be visible before we test
 867                  * NEED_RESCHED:
 868                  */
 869                 smp_mb();
 870
 871                 if (unlikely(need_resched())) {
 872                         current_thread_info()->status |= TS_POLLING;
 873                         return -EINVAL;
 874                 }
 875         }
 876
 877         acpi_unlazy_tlb(smp_processor_id());
 878
 879         /* Tell the scheduler that we are going deep-idle: */
 880         sched_clock_idle_sleep_event();
 881         /*
 882          * Must be done before busmaster disable as we might need to
 883          * access HPET !
 884          */
 885         lapic_timer_state_broadcast(pr, cx, 1);
 886
 887         /*
 888          * disable bus master
 889          * bm_check implies we need ARB_DIS
 890          * !bm_check implies we need cache flush
 891          * bm_control implies whether we can do ARB_DIS
 892          *
 893          * That leaves a case where bm_check is set and bm_control is
 894          * not set. In that case we cannot do much, we enter C3
 895          * without doing anything.
 896          */
 897         if (pr->flags.bm_check && pr->flags.bm_control) {
 898                 raw_spin_lock(&c3_lock);
 899                 c3_cpu_count++;
 900                 /* Disable bus master arbitration when all CPUs are in C3 */
 901                 if (c3_cpu_count == num_online_cpus())
 902                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 903                 raw_spin_unlock(&c3_lock);
 904         } else if (!pr->flags.bm_check) {
 905                 ACPI_FLUSH_CPU_CACHE();
 906         }
 907
 908         acpi_idle_do_entry(cx);
 909
 910         /* Re-enable bus master arbitration */
 911         if (pr->flags.bm_check && pr->flags.bm_control) {
 912                 raw_spin_lock(&c3_lock);
 913                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 914                 c3_cpu_count--;
 915                 raw_spin_unlock(&c3_lock);
 916         }
 917
 918         sched_clock_idle_wakeup_event(0);
 919
 920         if (cx->entry_method != ACPI_CSTATE_FFH)
 921                 current_thread_info()->status |= TS_POLLING;
 922
 923         lapic_timer_state_broadcast(pr, cx, 0);
 924         return index;
 925 }
 926
 927 struct cpuidle_driver acpi_idle_driver = {
 928         .name =         "acpi_idle",
 929         .owner =        THIS_MODULE,
 930 };
 931
 932 /**
 933  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
 934  * device i.e. per-cpu data
 935  *
 936  * @pr: the ACPI processor
 937  * @dev : the cpuidle device
 938  */
 939 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 940                                            struct cpuidle_device *dev)
 941 {
 942         int i, count = CPUIDLE_DRIVER_STATE_START;
 943         struct acpi_processor_cx *cx;
 944
 945         if (!pr->flags.power_setup_done)
 946                 return -EINVAL;
 947
 948         if (pr->flags.power == 0) {
 949                 return -EINVAL;
 950         }
 951
 952         if (!dev)
 953                 return -EINVAL;
 954
 955         dev->cpu = pr->id;
 956
 957         if (max_cstate == 0)
 958                 max_cstate = 1;
 959
 960         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 961                 cx = &pr->power.states[i];
 962
 963                 if (!cx->valid)
 964                         continue;
 965
 966 #ifdef CONFIG_HOTPLUG_CPU
 967                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
 968                     !pr->flags.has_cst &&
 969                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 970                         continue;
 971 #endif
 972                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 973
 974                 count++;
 975                 if (count == CPUIDLE_STATE_MAX)
 976                         break;
 977         }
 978
 979         dev->state_count = count;
 980
 981         if (!count)
 982                 return -EINVAL;
 983
 984         return 0;
 985 }
 986
 987 /**
 988  * acpi_processor_setup_cpuidle states- prepares and configures cpuidle
 989  * global state data i.e. idle routines
 990  *
 991  * @pr: the ACPI processor
 992  */
 993 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 994 {
 995         int i, count = CPUIDLE_DRIVER_STATE_START;
 996         struct acpi_processor_cx *cx;
 997         struct cpuidle_state *state;
 998         struct cpuidle_driver *drv = &acpi_idle_driver;
 999
1000         if (!pr->flags.power_setup_done)
1001                 return -EINVAL;
1002
1003         if (pr->flags.power == 0)
1004                 return -EINVAL;
1005
1006         drv->safe_state_index = -1;
1007         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1008                 drv->states[i].name[0] = '\0';
1009                 drv->states[i].desc[0] = '\0';
1010         }
1011
1012         if (max_cstate == 0)
1013                 max_cstate = 1;
1014
1015         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1016                 cx = &pr->power.states[i];
1017
1018                 if (!cx->valid)
1019                         continue;
1020
1021 #ifdef CONFIG_HOTPLUG_CPU
1022                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1023                     !pr->flags.has_cst &&
1024                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1025                         continue;
1026 #endif
1027
1028                 state = &drv->states[count];
1029                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1030                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1031                 state->exit_latency = cx->latency;
1032                 state->target_residency = cx->latency * latency_factor;
1033
1034                 state->flags = 0;
1035                 switch (cx->type) {
1036                         case ACPI_STATE_C1:
1037                         if (cx->entry_method == ACPI_CSTATE_FFH)
1038                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1039
1040                         state->enter = acpi_idle_enter_c1;
1041                         state->enter_dead = acpi_idle_play_dead;
1042                         drv->safe_state_index = count;
1043                         break;
1044
1045                         case ACPI_STATE_C2:
1046                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1047                         state->enter = acpi_idle_enter_simple;
1048                         state->enter_dead = acpi_idle_play_dead;
1049                         drv->safe_state_index = count;
1050                         break;
1051
1052                         case ACPI_STATE_C3:
1053                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1054                         state->enter = pr->flags.bm_check ?
1055                                         acpi_idle_enter_bm :
1056                                         acpi_idle_enter_simple;
1057                         break;
1058                 }
1059
1060                 count++;
1061                 if (count == CPUIDLE_STATE_MAX)
1062                         break;
1063         }
1064
1065         drv->state_count = count;
1066
1067         if (!count)
1068                 return -EINVAL;
1069
1070         return 0;
1071 }
1072
1073 int acpi_processor_hotplug(struct acpi_processor *pr)
1074 {
1075         int ret = 0;
1076         struct cpuidle_device *dev;
1077
1078         if (disabled_by_idle_boot_param())
1079                 return 0;
1080
1081         if (!pr)
1082                 return -EINVAL;
1083
1084         if (nocst) {
1085                 return -ENODEV;
1086         }
1087
1088         if (!pr->flags.power_setup_done)
1089                 return -ENODEV;
1090
1091         dev = per_cpu(acpi_cpuidle_device, pr->id);
1092         cpuidle_pause_and_lock();
1093         cpuidle_disable_device(dev);
1094         acpi_processor_get_power_info(pr);
1095         if (pr->flags.power) {
1096                 acpi_processor_setup_cpuidle_cx(pr, dev);
1097                 ret = cpuidle_enable_device(dev);
1098         }
1099         cpuidle_resume_and_unlock();
1100
1101         return ret;
1102 }
1103
1104 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1105 {
1106         int cpu;
1107         struct acpi_processor *_pr;
1108         struct cpuidle_device *dev;
1109
1110         if (disabled_by_idle_boot_param())
1111                 return 0;
1112
1113         if (!pr)
1114                 return -EINVAL;
1115
1116         if (nocst)
1117                 return -ENODEV;
1118
1119         if (!pr->flags.power_setup_done)
1120                 return -ENODEV;
1121
1122         /*
1123          * FIXME:  Design the ACPI notification to make it once per
1124          * system instead of once per-cpu.  This condition is a hack
1125          * to make the code that updates C-States be called once.
1126          */
1127
1128         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1129
1130                 cpuidle_pause_and_lock();
1131                 /* Protect against cpu-hotplug */
1132                 get_online_cpus();
1133
1134                 /* Disable all cpuidle devices */
1135                 for_each_online_cpu(cpu) {
1136                         _pr = per_cpu(processors, cpu);
1137                         if (!_pr || !_pr->flags.power_setup_done)
1138                                 continue;
1139                         dev = per_cpu(acpi_cpuidle_device, cpu);
1140                         cpuidle_disable_device(dev);
1141                 }
1142
1143                 /* Populate Updated C-state information */
1144                 acpi_processor_get_power_info(pr);
1145                 acpi_processor_setup_cpuidle_states(pr);
1146
1147                 /* Enable all cpuidle devices */
1148                 for_each_online_cpu(cpu) {
1149                         _pr = per_cpu(processors, cpu);
1150                         if (!_pr || !_pr->flags.power_setup_done)
1151                                 continue;
1152                         acpi_processor_get_power_info(_pr);
1153                         if (_pr->flags.power) {
1154                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1155                                 acpi_processor_setup_cpuidle_cx(_pr, dev);
1156                                 cpuidle_enable_device(dev);
1157                         }
1158                 }
1159                 put_online_cpus();
1160                 cpuidle_resume_and_unlock();
1161         }
1162
1163         return 0;
1164 }
1165
1166 static int acpi_processor_registered;
1167
1168 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
1169 {
1170         acpi_status status = 0;
1171         int retval;
1172         struct cpuidle_device *dev;
1173         static int first_run;
1174
1175         if (disabled_by_idle_boot_param())
1176                 return 0;
1177
1178         if (!first_run) {
1179                 dmi_check_system(processor_power_dmi_table);
1180                 max_cstate = acpi_processor_cstate_check(max_cstate);
1181                 if (max_cstate < ACPI_C_STATES_MAX)
1182                         printk(KERN_NOTICE
1183                                "ACPI: processor limited to max C-state %d\n",
1184                                max_cstate);
1185                 first_run++;
1186         }
1187
1188         if (!pr)
1189                 return -EINVAL;
1190
1191         if (acpi_gbl_FADT.cst_control && !nocst) {
1192                 status =
1193                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1194                 if (ACPI_FAILURE(status)) {
1195                         ACPI_EXCEPTION((AE_INFO, status,
1196                                         "Notifying BIOS of _CST ability failed"));
1197                 }
1198         }
1199
1200         acpi_processor_get_power_info(pr);
1201         pr->flags.power_setup_done = 1;
1202
1203         /*
1204          * Install the idle handler if processor power management is supported.
1205          * Note that we use previously set idle handler will be used on
1206          * platforms that only support C1.
1207          */
1208         if (pr->flags.power) {
1209                 /* Register acpi_idle_driver if not already registered */
1210                 if (!acpi_processor_registered) {
1211                         acpi_processor_setup_cpuidle_states(pr);
1212                         retval = cpuidle_register_driver(&acpi_idle_driver);
1213                         if (retval)
1214                                 return retval;
1215                         printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
1216                                         acpi_idle_driver.name);
1217                 }
1218
1219                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1220                 if (!dev)
1221                         return -ENOMEM;
1222                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1223
1224                 acpi_processor_setup_cpuidle_cx(pr, dev);
1225
1226                 /* Register per-cpu cpuidle_device. Cpuidle driver
1227                  * must already be registered before registering device
1228                  */
1229                 retval = cpuidle_register_device(dev);
1230                 if (retval) {
1231                         if (acpi_processor_registered == 0)
1232                                 cpuidle_unregister_driver(&acpi_idle_driver);
1233                         return retval;
1234                 }
1235                 acpi_processor_registered++;
1236         }
1237         return 0;
1238 }
1239
1240 int acpi_processor_power_exit(struct acpi_processor *pr)
1241 {
1242         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1243
1244         if (disabled_by_idle_boot_param())
1245                 return 0;
1246
1247         if (pr->flags.power) {
1248                 cpuidle_unregister_device(dev);
1249                 acpi_processor_registered--;
1250                 if (acpi_processor_registered == 0)
1251                         cpuidle_unregister_driver(&acpi_idle_driver);
1252         }
1253
1254         pr->flags.power_setup_done = 0;
1255         return 0;
1256 }