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