1 /* 2 * processor_idle - idle state submodule to the ACPI processor driver 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de> 7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 8 * - Added processor hotplug support 9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 10 * - Added support for C3 on SMP 11 * 12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License as published by 16 * the Free Software Foundation; either version 2 of the License, or (at 17 * your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License along 25 * with this program; if not, write to the Free Software Foundation, Inc., 26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 27 * 28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 29 */ 30 31 #include <linux/kernel.h> 32 #include <linux/module.h> 33 #include <linux/init.h> 34 #include <linux/cpufreq.h> 35 #include <linux/proc_fs.h> 36 #include <linux/seq_file.h> 37 #include <linux/acpi.h> 38 #include <linux/dmi.h> 39 #include <linux/moduleparam.h> 40 #include <linux/sched.h> /* need_resched() */ 41 #include <linux/pm_qos_params.h> 42 #include <linux/clockchips.h> 43 #include <linux/cpuidle.h> 44 45 /* 46 * Include the apic definitions for x86 to have the APIC timer related defines 47 * available also for UP (on SMP it gets magically included via linux/smp.h). 48 * asm/acpi.h is not an option, as it would require more include magic. Also 49 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 50 */ 51 #ifdef CONFIG_X86 52 #include <asm/apic.h> 53 #endif 54 55 #include <asm/io.h> 56 #include <asm/uaccess.h> 57 58 #include <acpi/acpi_bus.h> 59 #include <acpi/processor.h> 60 61 #define ACPI_PROCESSOR_COMPONENT 0x01000000 62 #define ACPI_PROCESSOR_CLASS "processor" 63 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 64 ACPI_MODULE_NAME("processor_idle"); 65 #define ACPI_PROCESSOR_FILE_POWER "power" 66 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000) 67 #define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY) 68 #ifndef CONFIG_CPU_IDLE 69 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 70 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 71 static void (*pm_idle_save) (void) __read_mostly; 72 #else 73 #define C2_OVERHEAD 1 /* 1us */ 74 #define C3_OVERHEAD 1 /* 1us */ 75 #endif 76 #define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000)) 77 78 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 79 #ifdef CONFIG_CPU_IDLE 80 module_param(max_cstate, uint, 0000); 81 #else 82 module_param(max_cstate, uint, 0644); 83 #endif 84 static unsigned int nocst __read_mostly; 85 module_param(nocst, uint, 0000); 86 87 #ifndef CONFIG_CPU_IDLE 88 /* 89 * bm_history -- bit-mask with a bit per jiffy of bus-master activity 90 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms 91 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms 92 * 100 HZ: 0x0000000F: 4 jiffies = 40ms 93 * reduce history for more aggressive entry into C3 94 */ 95 static unsigned int bm_history __read_mostly = 96 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1)); 97 module_param(bm_history, uint, 0644); 98 99 static int acpi_processor_set_power_policy(struct acpi_processor *pr); 100 101 #else /* CONFIG_CPU_IDLE */ 102 static unsigned int latency_factor __read_mostly = 2; 103 module_param(latency_factor, uint, 0644); 104 #endif 105 106 /* 107 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 108 * For now disable this. Probably a bug somewhere else. 109 * 110 * To skip this limit, boot/load with a large max_cstate limit. 111 */ 112 static int set_max_cstate(const struct dmi_system_id *id) 113 { 114 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 115 return 0; 116 117 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate." 118 " Override with \"processor.max_cstate=%d\"\n", id->ident, 119 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 120 121 max_cstate = (long)id->driver_data; 122 123 return 0; 124 } 125 126 /* Actually this shouldn't be __cpuinitdata, would be better to fix the 127 callers to only run once -AK */ 128 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = { 129 { set_max_cstate, "IBM ThinkPad R40e", { 130 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 131 DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1}, 132 { set_max_cstate, "IBM ThinkPad R40e", { 133 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 134 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1}, 135 { set_max_cstate, "IBM ThinkPad R40e", { 136 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 137 DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1}, 138 { set_max_cstate, "IBM ThinkPad R40e", { 139 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 140 DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1}, 141 { set_max_cstate, "IBM ThinkPad R40e", { 142 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 143 DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1}, 144 { set_max_cstate, "IBM ThinkPad R40e", { 145 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 146 DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1}, 147 { set_max_cstate, "IBM ThinkPad R40e", { 148 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 149 DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1}, 150 { set_max_cstate, "IBM ThinkPad R40e", { 151 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 152 DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1}, 153 { set_max_cstate, "IBM ThinkPad R40e", { 154 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 155 DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1}, 156 { set_max_cstate, "IBM ThinkPad R40e", { 157 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 158 DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1}, 159 { set_max_cstate, "IBM ThinkPad R40e", { 160 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 161 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1}, 162 { set_max_cstate, "IBM ThinkPad R40e", { 163 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 164 DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1}, 165 { set_max_cstate, "IBM ThinkPad R40e", { 166 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 167 DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1}, 168 { set_max_cstate, "IBM ThinkPad R40e", { 169 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 170 DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1}, 171 { set_max_cstate, "IBM ThinkPad R40e", { 172 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 173 DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1}, 174 { set_max_cstate, "IBM ThinkPad R40e", { 175 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 176 DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1}, 177 { set_max_cstate, "Medion 41700", { 178 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 179 DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1}, 180 { set_max_cstate, "Clevo 5600D", { 181 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 182 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 183 (void *)2}, 184 {}, 185 }; 186 187 static inline u32 ticks_elapsed(u32 t1, u32 t2) 188 { 189 if (t2 >= t1) 190 return (t2 - t1); 191 else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER)) 192 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF); 193 else 194 return ((0xFFFFFFFF - t1) + t2); 195 } 196 197 static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2) 198 { 199 if (t2 >= t1) 200 return PM_TIMER_TICKS_TO_US(t2 - t1); 201 else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER)) 202 return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF); 203 else 204 return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2); 205 } 206 207 /* 208 * Callers should disable interrupts before the call and enable 209 * interrupts after return. 210 */ 211 static void acpi_safe_halt(void) 212 { 213 current_thread_info()->status &= ~TS_POLLING; 214 /* 215 * TS_POLLING-cleared state must be visible before we 216 * test NEED_RESCHED: 217 */ 218 smp_mb(); 219 if (!need_resched()) 220 safe_halt(); 221 current_thread_info()->status |= TS_POLLING; 222 } 223 224 #ifndef CONFIG_CPU_IDLE 225 226 static void 227 acpi_processor_power_activate(struct acpi_processor *pr, 228 struct acpi_processor_cx *new) 229 { 230 struct acpi_processor_cx *old; 231 232 if (!pr || !new) 233 return; 234 235 old = pr->power.state; 236 237 if (old) 238 old->promotion.count = 0; 239 new->demotion.count = 0; 240 241 /* Cleanup from old state. */ 242 if (old) { 243 switch (old->type) { 244 case ACPI_STATE_C3: 245 /* Disable bus master reload */ 246 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check) 247 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0); 248 break; 249 } 250 } 251 252 /* Prepare to use new state. */ 253 switch (new->type) { 254 case ACPI_STATE_C3: 255 /* Enable bus master reload */ 256 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check) 257 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 258 break; 259 } 260 261 pr->power.state = new; 262 263 return; 264 } 265 266 static atomic_t c3_cpu_count; 267 268 /* Common C-state entry for C2, C3, .. */ 269 static void acpi_cstate_enter(struct acpi_processor_cx *cstate) 270 { 271 if (cstate->entry_method == ACPI_CSTATE_FFH) { 272 /* Call into architectural FFH based C-state */ 273 acpi_processor_ffh_cstate_enter(cstate); 274 } else { 275 int unused; 276 /* IO port based C-state */ 277 inb(cstate->address); 278 /* Dummy wait op - must do something useless after P_LVL2 read 279 because chipsets cannot guarantee that STPCLK# signal 280 gets asserted in time to freeze execution properly. */ 281 unused = inl(acpi_gbl_FADT.xpm_timer_block.address); 282 } 283 } 284 #endif /* !CONFIG_CPU_IDLE */ 285 286 #ifdef ARCH_APICTIMER_STOPS_ON_C3 287 288 /* 289 * Some BIOS implementations switch to C3 in the published C2 state. 290 * This seems to be a common problem on AMD boxen, but other vendors 291 * are affected too. We pick the most conservative approach: we assume 292 * that the local APIC stops in both C2 and C3. 293 */ 294 static void acpi_timer_check_state(int state, struct acpi_processor *pr, 295 struct acpi_processor_cx *cx) 296 { 297 struct acpi_processor_power *pwr = &pr->power; 298 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 299 300 /* 301 * Check, if one of the previous states already marked the lapic 302 * unstable 303 */ 304 if (pwr->timer_broadcast_on_state < state) 305 return; 306 307 if (cx->type >= type) 308 pr->power.timer_broadcast_on_state = state; 309 } 310 311 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) 312 { 313 unsigned long reason; 314 315 reason = pr->power.timer_broadcast_on_state < INT_MAX ? 316 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF; 317 318 clockevents_notify(reason, &pr->id); 319 } 320 321 /* Power(C) State timer broadcast control */ 322 static void acpi_state_timer_broadcast(struct acpi_processor *pr, 323 struct acpi_processor_cx *cx, 324 int broadcast) 325 { 326 int state = cx - pr->power.states; 327 328 if (state >= pr->power.timer_broadcast_on_state) { 329 unsigned long reason; 330 331 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER : 332 CLOCK_EVT_NOTIFY_BROADCAST_EXIT; 333 clockevents_notify(reason, &pr->id); 334 } 335 } 336 337 #else 338 339 static void acpi_timer_check_state(int state, struct acpi_processor *pr, 340 struct acpi_processor_cx *cstate) { } 341 static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { } 342 static void acpi_state_timer_broadcast(struct acpi_processor *pr, 343 struct acpi_processor_cx *cx, 344 int broadcast) 345 { 346 } 347 348 #endif 349 350 /* 351 * Suspend / resume control 352 */ 353 static int acpi_idle_suspend; 354 355 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) 356 { 357 acpi_idle_suspend = 1; 358 return 0; 359 } 360 361 int acpi_processor_resume(struct acpi_device * device) 362 { 363 acpi_idle_suspend = 0; 364 return 0; 365 } 366 367 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) 368 static int tsc_halts_in_c(int state) 369 { 370 switch (boot_cpu_data.x86_vendor) { 371 case X86_VENDOR_AMD: 372 /* 373 * AMD Fam10h TSC will tick in all 374 * C/P/S0/S1 states when this bit is set. 375 */ 376 if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) 377 return 0; 378 /*FALL THROUGH*/ 379 case X86_VENDOR_INTEL: 380 /* Several cases known where TSC halts in C2 too */ 381 default: 382 return state > ACPI_STATE_C1; 383 } 384 } 385 #endif 386 387 #ifndef CONFIG_CPU_IDLE 388 static void acpi_processor_idle(void) 389 { 390 struct acpi_processor *pr = NULL; 391 struct acpi_processor_cx *cx = NULL; 392 struct acpi_processor_cx *next_state = NULL; 393 int sleep_ticks = 0; 394 u32 t1, t2 = 0; 395 396 /* 397 * Interrupts must be disabled during bus mastering calculations and 398 * for C2/C3 transitions. 399 */ 400 local_irq_disable(); 401 402 pr = processors[smp_processor_id()]; 403 if (!pr) { 404 local_irq_enable(); 405 return; 406 } 407 408 /* 409 * Check whether we truly need to go idle, or should 410 * reschedule: 411 */ 412 if (unlikely(need_resched())) { 413 local_irq_enable(); 414 return; 415 } 416 417 cx = pr->power.state; 418 if (!cx || acpi_idle_suspend) { 419 if (pm_idle_save) 420 pm_idle_save(); 421 else 422 acpi_safe_halt(); 423 424 local_irq_enable(); 425 return; 426 } 427 428 /* 429 * Check BM Activity 430 * ----------------- 431 * Check for bus mastering activity (if required), record, and check 432 * for demotion. 433 */ 434 if (pr->flags.bm_check) { 435 u32 bm_status = 0; 436 unsigned long diff = jiffies - pr->power.bm_check_timestamp; 437 438 if (diff > 31) 439 diff = 31; 440 441 pr->power.bm_activity <<= diff; 442 443 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 444 if (bm_status) { 445 pr->power.bm_activity |= 0x1; 446 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 447 } 448 /* 449 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 450 * the true state of bus mastering activity; forcing us to 451 * manually check the BMIDEA bit of each IDE channel. 452 */ 453 else if (errata.piix4.bmisx) { 454 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 455 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 456 pr->power.bm_activity |= 0x1; 457 } 458 459 pr->power.bm_check_timestamp = jiffies; 460 461 /* 462 * If bus mastering is or was active this jiffy, demote 463 * to avoid a faulty transition. Note that the processor 464 * won't enter a low-power state during this call (to this 465 * function) but should upon the next. 466 * 467 * TBD: A better policy might be to fallback to the demotion 468 * state (use it for this quantum only) istead of 469 * demoting -- and rely on duration as our sole demotion 470 * qualification. This may, however, introduce DMA 471 * issues (e.g. floppy DMA transfer overrun/underrun). 472 */ 473 if ((pr->power.bm_activity & 0x1) && 474 cx->demotion.threshold.bm) { 475 local_irq_enable(); 476 next_state = cx->demotion.state; 477 goto end; 478 } 479 } 480 481 #ifdef CONFIG_HOTPLUG_CPU 482 /* 483 * Check for P_LVL2_UP flag before entering C2 and above on 484 * an SMP system. We do it here instead of doing it at _CST/P_LVL 485 * detection phase, to work cleanly with logical CPU hotplug. 486 */ 487 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 488 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 489 cx = &pr->power.states[ACPI_STATE_C1]; 490 #endif 491 492 /* 493 * Sleep: 494 * ------ 495 * Invoke the current Cx state to put the processor to sleep. 496 */ 497 if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) { 498 current_thread_info()->status &= ~TS_POLLING; 499 /* 500 * TS_POLLING-cleared state must be visible before we 501 * test NEED_RESCHED: 502 */ 503 smp_mb(); 504 if (need_resched()) { 505 current_thread_info()->status |= TS_POLLING; 506 local_irq_enable(); 507 return; 508 } 509 } 510 511 switch (cx->type) { 512 513 case ACPI_STATE_C1: 514 /* 515 * Invoke C1. 516 * Use the appropriate idle routine, the one that would 517 * be used without acpi C-states. 518 */ 519 if (pm_idle_save) 520 pm_idle_save(); 521 else 522 acpi_safe_halt(); 523 524 /* 525 * TBD: Can't get time duration while in C1, as resumes 526 * go to an ISR rather than here. Need to instrument 527 * base interrupt handler. 528 * 529 * Note: the TSC better not stop in C1, sched_clock() will 530 * skew otherwise. 531 */ 532 sleep_ticks = 0xFFFFFFFF; 533 local_irq_enable(); 534 break; 535 536 case ACPI_STATE_C2: 537 /* Get start time (ticks) */ 538 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); 539 /* Tell the scheduler that we are going deep-idle: */ 540 sched_clock_idle_sleep_event(); 541 /* Invoke C2 */ 542 acpi_state_timer_broadcast(pr, cx, 1); 543 acpi_cstate_enter(cx); 544 /* Get end time (ticks) */ 545 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); 546 547 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) 548 /* TSC halts in C2, so notify users */ 549 if (tsc_halts_in_c(ACPI_STATE_C2)) 550 mark_tsc_unstable("possible TSC halt in C2"); 551 #endif 552 /* Compute time (ticks) that we were actually asleep */ 553 sleep_ticks = ticks_elapsed(t1, t2); 554 555 /* Tell the scheduler how much we idled: */ 556 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); 557 558 /* Re-enable interrupts */ 559 local_irq_enable(); 560 /* Do not account our idle-switching overhead: */ 561 sleep_ticks -= cx->latency_ticks + C2_OVERHEAD; 562 563 current_thread_info()->status |= TS_POLLING; 564 acpi_state_timer_broadcast(pr, cx, 0); 565 break; 566 567 case ACPI_STATE_C3: 568 acpi_unlazy_tlb(smp_processor_id()); 569 /* 570 * Must be done before busmaster disable as we might 571 * need to access HPET ! 572 */ 573 acpi_state_timer_broadcast(pr, cx, 1); 574 /* 575 * disable bus master 576 * bm_check implies we need ARB_DIS 577 * !bm_check implies we need cache flush 578 * bm_control implies whether we can do ARB_DIS 579 * 580 * That leaves a case where bm_check is set and bm_control is 581 * not set. In that case we cannot do much, we enter C3 582 * without doing anything. 583 */ 584 if (pr->flags.bm_check && pr->flags.bm_control) { 585 if (atomic_inc_return(&c3_cpu_count) == 586 num_online_cpus()) { 587 /* 588 * All CPUs are trying to go to C3 589 * Disable bus master arbitration 590 */ 591 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1); 592 } 593 } else if (!pr->flags.bm_check) { 594 /* SMP with no shared cache... Invalidate cache */ 595 ACPI_FLUSH_CPU_CACHE(); 596 } 597 598 /* Get start time (ticks) */ 599 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); 600 /* Invoke C3 */ 601 /* Tell the scheduler that we are going deep-idle: */ 602 sched_clock_idle_sleep_event(); 603 acpi_cstate_enter(cx); 604 /* Get end time (ticks) */ 605 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); 606 if (pr->flags.bm_check && pr->flags.bm_control) { 607 /* Enable bus master arbitration */ 608 atomic_dec(&c3_cpu_count); 609 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0); 610 } 611 612 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) 613 /* TSC halts in C3, so notify users */ 614 if (tsc_halts_in_c(ACPI_STATE_C3)) 615 mark_tsc_unstable("TSC halts in C3"); 616 #endif 617 /* Compute time (ticks) that we were actually asleep */ 618 sleep_ticks = ticks_elapsed(t1, t2); 619 /* Tell the scheduler how much we idled: */ 620 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); 621 622 /* Re-enable interrupts */ 623 local_irq_enable(); 624 /* Do not account our idle-switching overhead: */ 625 sleep_ticks -= cx->latency_ticks + C3_OVERHEAD; 626 627 current_thread_info()->status |= TS_POLLING; 628 acpi_state_timer_broadcast(pr, cx, 0); 629 break; 630 631 default: 632 local_irq_enable(); 633 return; 634 } 635 cx->usage++; 636 if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0)) 637 cx->time += sleep_ticks; 638 639 next_state = pr->power.state; 640 641 #ifdef CONFIG_HOTPLUG_CPU 642 /* Don't do promotion/demotion */ 643 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) && 644 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) { 645 next_state = cx; 646 goto end; 647 } 648 #endif 649 650 /* 651 * Promotion? 652 * ---------- 653 * Track the number of longs (time asleep is greater than threshold) 654 * and promote when the count threshold is reached. Note that bus 655 * mastering activity may prevent promotions. 656 * Do not promote above max_cstate. 657 */ 658 if (cx->promotion.state && 659 ((cx->promotion.state - pr->power.states) <= max_cstate)) { 660 if (sleep_ticks > cx->promotion.threshold.ticks && 661 cx->promotion.state->latency <= 662 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) { 663 cx->promotion.count++; 664 cx->demotion.count = 0; 665 if (cx->promotion.count >= 666 cx->promotion.threshold.count) { 667 if (pr->flags.bm_check) { 668 if (! 669 (pr->power.bm_activity & cx-> 670 promotion.threshold.bm)) { 671 next_state = 672 cx->promotion.state; 673 goto end; 674 } 675 } else { 676 next_state = cx->promotion.state; 677 goto end; 678 } 679 } 680 } 681 } 682 683 /* 684 * Demotion? 685 * --------- 686 * Track the number of shorts (time asleep is less than time threshold) 687 * and demote when the usage threshold is reached. 688 */ 689 if (cx->demotion.state) { 690 if (sleep_ticks < cx->demotion.threshold.ticks) { 691 cx->demotion.count++; 692 cx->promotion.count = 0; 693 if (cx->demotion.count >= cx->demotion.threshold.count) { 694 next_state = cx->demotion.state; 695 goto end; 696 } 697 } 698 } 699 700 end: 701 /* 702 * Demote if current state exceeds max_cstate 703 * or if the latency of the current state is unacceptable 704 */ 705 if ((pr->power.state - pr->power.states) > max_cstate || 706 pr->power.state->latency > 707 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) { 708 if (cx->demotion.state) 709 next_state = cx->demotion.state; 710 } 711 712 /* 713 * New Cx State? 714 * ------------- 715 * If we're going to start using a new Cx state we must clean up 716 * from the previous and prepare to use the new. 717 */ 718 if (next_state != pr->power.state) 719 acpi_processor_power_activate(pr, next_state); 720 } 721 722 static int acpi_processor_set_power_policy(struct acpi_processor *pr) 723 { 724 unsigned int i; 725 unsigned int state_is_set = 0; 726 struct acpi_processor_cx *lower = NULL; 727 struct acpi_processor_cx *higher = NULL; 728 struct acpi_processor_cx *cx; 729 730 731 if (!pr) 732 return -EINVAL; 733 734 /* 735 * This function sets the default Cx state policy (OS idle handler). 736 * Our scheme is to promote quickly to C2 but more conservatively 737 * to C3. We're favoring C2 for its characteristics of low latency 738 * (quick response), good power savings, and ability to allow bus 739 * mastering activity. Note that the Cx state policy is completely 740 * customizable and can be altered dynamically. 741 */ 742 743 /* startup state */ 744 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 745 cx = &pr->power.states[i]; 746 if (!cx->valid) 747 continue; 748 749 if (!state_is_set) 750 pr->power.state = cx; 751 state_is_set++; 752 break; 753 } 754 755 if (!state_is_set) 756 return -ENODEV; 757 758 /* demotion */ 759 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 760 cx = &pr->power.states[i]; 761 if (!cx->valid) 762 continue; 763 764 if (lower) { 765 cx->demotion.state = lower; 766 cx->demotion.threshold.ticks = cx->latency_ticks; 767 cx->demotion.threshold.count = 1; 768 if (cx->type == ACPI_STATE_C3) 769 cx->demotion.threshold.bm = bm_history; 770 } 771 772 lower = cx; 773 } 774 775 /* promotion */ 776 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) { 777 cx = &pr->power.states[i]; 778 if (!cx->valid) 779 continue; 780 781 if (higher) { 782 cx->promotion.state = higher; 783 cx->promotion.threshold.ticks = cx->latency_ticks; 784 if (cx->type >= ACPI_STATE_C2) 785 cx->promotion.threshold.count = 4; 786 else 787 cx->promotion.threshold.count = 10; 788 if (higher->type == ACPI_STATE_C3) 789 cx->promotion.threshold.bm = bm_history; 790 } 791 792 higher = cx; 793 } 794 795 return 0; 796 } 797 #endif /* !CONFIG_CPU_IDLE */ 798 799 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 800 { 801 802 if (!pr) 803 return -EINVAL; 804 805 if (!pr->pblk) 806 return -ENODEV; 807 808 /* if info is obtained from pblk/fadt, type equals state */ 809 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 810 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 811 812 #ifndef CONFIG_HOTPLUG_CPU 813 /* 814 * Check for P_LVL2_UP flag before entering C2 and above on 815 * an SMP system. 816 */ 817 if ((num_online_cpus() > 1) && 818 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 819 return -ENODEV; 820 #endif 821 822 /* determine C2 and C3 address from pblk */ 823 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 824 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 825 826 /* determine latencies from FADT */ 827 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency; 828 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency; 829 830 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 831 "lvl2[0x%08x] lvl3[0x%08x]\n", 832 pr->power.states[ACPI_STATE_C2].address, 833 pr->power.states[ACPI_STATE_C3].address)); 834 835 return 0; 836 } 837 838 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 839 { 840 if (!pr->power.states[ACPI_STATE_C1].valid) { 841 /* set the first C-State to C1 */ 842 /* all processors need to support C1 */ 843 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 844 pr->power.states[ACPI_STATE_C1].valid = 1; 845 } 846 /* the C0 state only exists as a filler in our array */ 847 pr->power.states[ACPI_STATE_C0].valid = 1; 848 return 0; 849 } 850 851 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 852 { 853 acpi_status status = 0; 854 acpi_integer count; 855 int current_count; 856 int i; 857 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 858 union acpi_object *cst; 859 860 861 if (nocst) 862 return -ENODEV; 863 864 current_count = 0; 865 866 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 867 if (ACPI_FAILURE(status)) { 868 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 869 return -ENODEV; 870 } 871 872 cst = buffer.pointer; 873 874 /* There must be at least 2 elements */ 875 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 876 printk(KERN_ERR PREFIX "not enough elements in _CST\n"); 877 status = -EFAULT; 878 goto end; 879 } 880 881 count = cst->package.elements[0].integer.value; 882 883 /* Validate number of power states. */ 884 if (count < 1 || count != cst->package.count - 1) { 885 printk(KERN_ERR PREFIX "count given by _CST is not valid\n"); 886 status = -EFAULT; 887 goto end; 888 } 889 890 /* Tell driver that at least _CST is supported. */ 891 pr->flags.has_cst = 1; 892 893 for (i = 1; i <= count; i++) { 894 union acpi_object *element; 895 union acpi_object *obj; 896 struct acpi_power_register *reg; 897 struct acpi_processor_cx cx; 898 899 memset(&cx, 0, sizeof(cx)); 900 901 element = &(cst->package.elements[i]); 902 if (element->type != ACPI_TYPE_PACKAGE) 903 continue; 904 905 if (element->package.count != 4) 906 continue; 907 908 obj = &(element->package.elements[0]); 909 910 if (obj->type != ACPI_TYPE_BUFFER) 911 continue; 912 913 reg = (struct acpi_power_register *)obj->buffer.pointer; 914 915 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 916 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 917 continue; 918 919 /* There should be an easy way to extract an integer... */ 920 obj = &(element->package.elements[1]); 921 if (obj->type != ACPI_TYPE_INTEGER) 922 continue; 923 924 cx.type = obj->integer.value; 925 /* 926 * Some buggy BIOSes won't list C1 in _CST - 927 * Let acpi_processor_get_power_info_default() handle them later 928 */ 929 if (i == 1 && cx.type != ACPI_STATE_C1) 930 current_count++; 931 932 cx.address = reg->address; 933 cx.index = current_count + 1; 934 935 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 936 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 937 if (acpi_processor_ffh_cstate_probe 938 (pr->id, &cx, reg) == 0) { 939 cx.entry_method = ACPI_CSTATE_FFH; 940 } else if (cx.type == ACPI_STATE_C1) { 941 /* 942 * C1 is a special case where FIXED_HARDWARE 943 * can be handled in non-MWAIT way as well. 944 * In that case, save this _CST entry info. 945 * Otherwise, ignore this info and continue. 946 */ 947 cx.entry_method = ACPI_CSTATE_HALT; 948 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 949 } else { 950 continue; 951 } 952 } else { 953 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 954 cx.address); 955 } 956 957 958 obj = &(element->package.elements[2]); 959 if (obj->type != ACPI_TYPE_INTEGER) 960 continue; 961 962 cx.latency = obj->integer.value; 963 964 obj = &(element->package.elements[3]); 965 if (obj->type != ACPI_TYPE_INTEGER) 966 continue; 967 968 cx.power = obj->integer.value; 969 970 current_count++; 971 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 972 973 /* 974 * We support total ACPI_PROCESSOR_MAX_POWER - 1 975 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 976 */ 977 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 978 printk(KERN_WARNING 979 "Limiting number of power states to max (%d)\n", 980 ACPI_PROCESSOR_MAX_POWER); 981 printk(KERN_WARNING 982 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 983 break; 984 } 985 } 986 987 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 988 current_count)); 989 990 /* Validate number of power states discovered */ 991 if (current_count < 2) 992 status = -EFAULT; 993 994 end: 995 kfree(buffer.pointer); 996 997 return status; 998 } 999 1000 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) 1001 { 1002 1003 if (!cx->address) 1004 return; 1005 1006 /* 1007 * C2 latency must be less than or equal to 100 1008 * microseconds. 1009 */ 1010 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 1011 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1012 "latency too large [%d]\n", cx->latency)); 1013 return; 1014 } 1015 1016 /* 1017 * Otherwise we've met all of our C2 requirements. 1018 * Normalize the C2 latency to expidite policy 1019 */ 1020 cx->valid = 1; 1021 1022 #ifndef CONFIG_CPU_IDLE 1023 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 1024 #else 1025 cx->latency_ticks = cx->latency; 1026 #endif 1027 1028 return; 1029 } 1030 1031 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 1032 struct acpi_processor_cx *cx) 1033 { 1034 static int bm_check_flag; 1035 1036 1037 if (!cx->address) 1038 return; 1039 1040 /* 1041 * C3 latency must be less than or equal to 1000 1042 * microseconds. 1043 */ 1044 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 1045 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1046 "latency too large [%d]\n", cx->latency)); 1047 return; 1048 } 1049 1050 /* 1051 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 1052 * DMA transfers are used by any ISA device to avoid livelock. 1053 * Note that we could disable Type-F DMA (as recommended by 1054 * the erratum), but this is known to disrupt certain ISA 1055 * devices thus we take the conservative approach. 1056 */ 1057 else if (errata.piix4.fdma) { 1058 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1059 "C3 not supported on PIIX4 with Type-F DMA\n")); 1060 return; 1061 } 1062 1063 /* All the logic here assumes flags.bm_check is same across all CPUs */ 1064 if (!bm_check_flag) { 1065 /* Determine whether bm_check is needed based on CPU */ 1066 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 1067 bm_check_flag = pr->flags.bm_check; 1068 } else { 1069 pr->flags.bm_check = bm_check_flag; 1070 } 1071 1072 if (pr->flags.bm_check) { 1073 if (!pr->flags.bm_control) { 1074 if (pr->flags.has_cst != 1) { 1075 /* bus mastering control is necessary */ 1076 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1077 "C3 support requires BM control\n")); 1078 return; 1079 } else { 1080 /* Here we enter C3 without bus mastering */ 1081 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1082 "C3 support without BM control\n")); 1083 } 1084 } 1085 } else { 1086 /* 1087 * WBINVD should be set in fadt, for C3 state to be 1088 * supported on when bm_check is not required. 1089 */ 1090 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 1091 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1092 "Cache invalidation should work properly" 1093 " for C3 to be enabled on SMP systems\n")); 1094 return; 1095 } 1096 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0); 1097 } 1098 1099 /* 1100 * Otherwise we've met all of our C3 requirements. 1101 * Normalize the C3 latency to expidite policy. Enable 1102 * checking of bus mastering status (bm_check) so we can 1103 * use this in our C3 policy 1104 */ 1105 cx->valid = 1; 1106 1107 #ifndef CONFIG_CPU_IDLE 1108 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 1109 #else 1110 cx->latency_ticks = cx->latency; 1111 #endif 1112 1113 return; 1114 } 1115 1116 static int acpi_processor_power_verify(struct acpi_processor *pr) 1117 { 1118 unsigned int i; 1119 unsigned int working = 0; 1120 1121 pr->power.timer_broadcast_on_state = INT_MAX; 1122 1123 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 1124 struct acpi_processor_cx *cx = &pr->power.states[i]; 1125 1126 switch (cx->type) { 1127 case ACPI_STATE_C1: 1128 cx->valid = 1; 1129 break; 1130 1131 case ACPI_STATE_C2: 1132 acpi_processor_power_verify_c2(cx); 1133 if (cx->valid) 1134 acpi_timer_check_state(i, pr, cx); 1135 break; 1136 1137 case ACPI_STATE_C3: 1138 acpi_processor_power_verify_c3(pr, cx); 1139 if (cx->valid) 1140 acpi_timer_check_state(i, pr, cx); 1141 break; 1142 } 1143 1144 if (cx->valid) 1145 working++; 1146 } 1147 1148 acpi_propagate_timer_broadcast(pr); 1149 1150 return (working); 1151 } 1152 1153 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1154 { 1155 unsigned int i; 1156 int result; 1157 1158 1159 /* NOTE: the idle thread may not be running while calling 1160 * this function */ 1161 1162 /* Zero initialize all the C-states info. */ 1163 memset(pr->power.states, 0, sizeof(pr->power.states)); 1164 1165 result = acpi_processor_get_power_info_cst(pr); 1166 if (result == -ENODEV) 1167 result = acpi_processor_get_power_info_fadt(pr); 1168 1169 if (result) 1170 return result; 1171 1172 acpi_processor_get_power_info_default(pr); 1173 1174 pr->power.count = acpi_processor_power_verify(pr); 1175 1176 #ifndef CONFIG_CPU_IDLE 1177 /* 1178 * Set Default Policy 1179 * ------------------ 1180 * Now that we know which states are supported, set the default 1181 * policy. Note that this policy can be changed dynamically 1182 * (e.g. encourage deeper sleeps to conserve battery life when 1183 * not on AC). 1184 */ 1185 result = acpi_processor_set_power_policy(pr); 1186 if (result) 1187 return result; 1188 #endif 1189 1190 /* 1191 * if one state of type C2 or C3 is available, mark this 1192 * CPU as being "idle manageable" 1193 */ 1194 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 1195 if (pr->power.states[i].valid) { 1196 pr->power.count = i; 1197 if (pr->power.states[i].type >= ACPI_STATE_C2) 1198 pr->flags.power = 1; 1199 } 1200 } 1201 1202 return 0; 1203 } 1204 1205 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) 1206 { 1207 struct acpi_processor *pr = seq->private; 1208 unsigned int i; 1209 1210 1211 if (!pr) 1212 goto end; 1213 1214 seq_printf(seq, "active state: C%zd\n" 1215 "max_cstate: C%d\n" 1216 "bus master activity: %08x\n" 1217 "maximum allowed latency: %d usec\n", 1218 pr->power.state ? pr->power.state - pr->power.states : 0, 1219 max_cstate, (unsigned)pr->power.bm_activity, 1220 pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)); 1221 1222 seq_puts(seq, "states:\n"); 1223 1224 for (i = 1; i <= pr->power.count; i++) { 1225 seq_printf(seq, " %cC%d: ", 1226 (&pr->power.states[i] == 1227 pr->power.state ? '*' : ' '), i); 1228 1229 if (!pr->power.states[i].valid) { 1230 seq_puts(seq, "<not supported>\n"); 1231 continue; 1232 } 1233 1234 switch (pr->power.states[i].type) { 1235 case ACPI_STATE_C1: 1236 seq_printf(seq, "type[C1] "); 1237 break; 1238 case ACPI_STATE_C2: 1239 seq_printf(seq, "type[C2] "); 1240 break; 1241 case ACPI_STATE_C3: 1242 seq_printf(seq, "type[C3] "); 1243 break; 1244 default: 1245 seq_printf(seq, "type[--] "); 1246 break; 1247 } 1248 1249 if (pr->power.states[i].promotion.state) 1250 seq_printf(seq, "promotion[C%zd] ", 1251 (pr->power.states[i].promotion.state - 1252 pr->power.states)); 1253 else 1254 seq_puts(seq, "promotion[--] "); 1255 1256 if (pr->power.states[i].demotion.state) 1257 seq_printf(seq, "demotion[C%zd] ", 1258 (pr->power.states[i].demotion.state - 1259 pr->power.states)); 1260 else 1261 seq_puts(seq, "demotion[--] "); 1262 1263 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n", 1264 pr->power.states[i].latency, 1265 pr->power.states[i].usage, 1266 (unsigned long long)pr->power.states[i].time); 1267 } 1268 1269 end: 1270 return 0; 1271 } 1272 1273 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file) 1274 { 1275 return single_open(file, acpi_processor_power_seq_show, 1276 PDE(inode)->data); 1277 } 1278 1279 static const struct file_operations acpi_processor_power_fops = { 1280 .open = acpi_processor_power_open_fs, 1281 .read = seq_read, 1282 .llseek = seq_lseek, 1283 .release = single_release, 1284 }; 1285 1286 #ifndef CONFIG_CPU_IDLE 1287 1288 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 1289 { 1290 int result = 0; 1291 1292 1293 if (!pr) 1294 return -EINVAL; 1295 1296 if (nocst) { 1297 return -ENODEV; 1298 } 1299 1300 if (!pr->flags.power_setup_done) 1301 return -ENODEV; 1302 1303 /* Fall back to the default idle loop */ 1304 pm_idle = pm_idle_save; 1305 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */ 1306 1307 pr->flags.power = 0; 1308 result = acpi_processor_get_power_info(pr); 1309 if ((pr->flags.power == 1) && (pr->flags.power_setup_done)) 1310 pm_idle = acpi_processor_idle; 1311 1312 return result; 1313 } 1314 1315 #ifdef CONFIG_SMP 1316 static void smp_callback(void *v) 1317 { 1318 /* we already woke the CPU up, nothing more to do */ 1319 } 1320 1321 /* 1322 * This function gets called when a part of the kernel has a new latency 1323 * requirement. This means we need to get all processors out of their C-state, 1324 * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that 1325 * wakes them all right up. 1326 */ 1327 static int acpi_processor_latency_notify(struct notifier_block *b, 1328 unsigned long l, void *v) 1329 { 1330 smp_call_function(smp_callback, NULL, 0, 1); 1331 return NOTIFY_OK; 1332 } 1333 1334 static struct notifier_block acpi_processor_latency_notifier = { 1335 .notifier_call = acpi_processor_latency_notify, 1336 }; 1337 1338 #endif 1339 1340 #else /* CONFIG_CPU_IDLE */ 1341 1342 /** 1343 * acpi_idle_bm_check - checks if bus master activity was detected 1344 */ 1345 static int acpi_idle_bm_check(void) 1346 { 1347 u32 bm_status = 0; 1348 1349 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 1350 if (bm_status) 1351 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 1352 /* 1353 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 1354 * the true state of bus mastering activity; forcing us to 1355 * manually check the BMIDEA bit of each IDE channel. 1356 */ 1357 else if (errata.piix4.bmisx) { 1358 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 1359 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 1360 bm_status = 1; 1361 } 1362 return bm_status; 1363 } 1364 1365 /** 1366 * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state 1367 * @pr: the processor 1368 * @target: the new target state 1369 */ 1370 static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr, 1371 struct acpi_processor_cx *target) 1372 { 1373 if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) { 1374 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0); 1375 pr->flags.bm_rld_set = 0; 1376 } 1377 1378 if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) { 1379 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 1380 pr->flags.bm_rld_set = 1; 1381 } 1382 } 1383 1384 /** 1385 * acpi_idle_do_entry - a helper function that does C2 and C3 type entry 1386 * @cx: cstate data 1387 * 1388 * Caller disables interrupt before call and enables interrupt after return. 1389 */ 1390 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx) 1391 { 1392 if (cx->entry_method == ACPI_CSTATE_FFH) { 1393 /* Call into architectural FFH based C-state */ 1394 acpi_processor_ffh_cstate_enter(cx); 1395 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 1396 acpi_safe_halt(); 1397 } else { 1398 int unused; 1399 /* IO port based C-state */ 1400 inb(cx->address); 1401 /* Dummy wait op - must do something useless after P_LVL2 read 1402 because chipsets cannot guarantee that STPCLK# signal 1403 gets asserted in time to freeze execution properly. */ 1404 unused = inl(acpi_gbl_FADT.xpm_timer_block.address); 1405 } 1406 } 1407 1408 /** 1409 * acpi_idle_enter_c1 - enters an ACPI C1 state-type 1410 * @dev: the target CPU 1411 * @state: the state data 1412 * 1413 * This is equivalent to the HALT instruction. 1414 */ 1415 static int acpi_idle_enter_c1(struct cpuidle_device *dev, 1416 struct cpuidle_state *state) 1417 { 1418 u32 t1, t2; 1419 struct acpi_processor *pr; 1420 struct acpi_processor_cx *cx = cpuidle_get_statedata(state); 1421 1422 pr = processors[smp_processor_id()]; 1423 1424 if (unlikely(!pr)) 1425 return 0; 1426 1427 local_irq_disable(); 1428 1429 /* Do not access any ACPI IO ports in suspend path */ 1430 if (acpi_idle_suspend) { 1431 acpi_safe_halt(); 1432 local_irq_enable(); 1433 return 0; 1434 } 1435 1436 if (pr->flags.bm_check) 1437 acpi_idle_update_bm_rld(pr, cx); 1438 1439 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1440 acpi_idle_do_entry(cx); 1441 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1442 1443 local_irq_enable(); 1444 cx->usage++; 1445 1446 return ticks_elapsed_in_us(t1, t2); 1447 } 1448 1449 /** 1450 * acpi_idle_enter_simple - enters an ACPI state without BM handling 1451 * @dev: the target CPU 1452 * @state: the state data 1453 */ 1454 static int acpi_idle_enter_simple(struct cpuidle_device *dev, 1455 struct cpuidle_state *state) 1456 { 1457 struct acpi_processor *pr; 1458 struct acpi_processor_cx *cx = cpuidle_get_statedata(state); 1459 u32 t1, t2; 1460 int sleep_ticks = 0; 1461 1462 pr = processors[smp_processor_id()]; 1463 1464 if (unlikely(!pr)) 1465 return 0; 1466 1467 if (acpi_idle_suspend) 1468 return(acpi_idle_enter_c1(dev, state)); 1469 1470 local_irq_disable(); 1471 current_thread_info()->status &= ~TS_POLLING; 1472 /* 1473 * TS_POLLING-cleared state must be visible before we test 1474 * NEED_RESCHED: 1475 */ 1476 smp_mb(); 1477 1478 if (unlikely(need_resched())) { 1479 current_thread_info()->status |= TS_POLLING; 1480 local_irq_enable(); 1481 return 0; 1482 } 1483 1484 acpi_unlazy_tlb(smp_processor_id()); 1485 /* 1486 * Must be done before busmaster disable as we might need to 1487 * access HPET ! 1488 */ 1489 acpi_state_timer_broadcast(pr, cx, 1); 1490 1491 if (pr->flags.bm_check) 1492 acpi_idle_update_bm_rld(pr, cx); 1493 1494 if (cx->type == ACPI_STATE_C3) 1495 ACPI_FLUSH_CPU_CACHE(); 1496 1497 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1498 /* Tell the scheduler that we are going deep-idle: */ 1499 sched_clock_idle_sleep_event(); 1500 acpi_idle_do_entry(cx); 1501 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1502 1503 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) 1504 /* TSC could halt in idle, so notify users */ 1505 if (tsc_halts_in_c(cx->type)) 1506 mark_tsc_unstable("TSC halts in idle");; 1507 #endif 1508 sleep_ticks = ticks_elapsed(t1, t2); 1509 1510 /* Tell the scheduler how much we idled: */ 1511 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); 1512 1513 local_irq_enable(); 1514 current_thread_info()->status |= TS_POLLING; 1515 1516 cx->usage++; 1517 1518 acpi_state_timer_broadcast(pr, cx, 0); 1519 cx->time += sleep_ticks; 1520 return ticks_elapsed_in_us(t1, t2); 1521 } 1522 1523 static int c3_cpu_count; 1524 static DEFINE_SPINLOCK(c3_lock); 1525 1526 /** 1527 * acpi_idle_enter_bm - enters C3 with proper BM handling 1528 * @dev: the target CPU 1529 * @state: the state data 1530 * 1531 * If BM is detected, the deepest non-C3 idle state is entered instead. 1532 */ 1533 static int acpi_idle_enter_bm(struct cpuidle_device *dev, 1534 struct cpuidle_state *state) 1535 { 1536 struct acpi_processor *pr; 1537 struct acpi_processor_cx *cx = cpuidle_get_statedata(state); 1538 u32 t1, t2; 1539 int sleep_ticks = 0; 1540 1541 pr = processors[smp_processor_id()]; 1542 1543 if (unlikely(!pr)) 1544 return 0; 1545 1546 if (acpi_idle_suspend) 1547 return(acpi_idle_enter_c1(dev, state)); 1548 1549 if (acpi_idle_bm_check()) { 1550 if (dev->safe_state) { 1551 return dev->safe_state->enter(dev, dev->safe_state); 1552 } else { 1553 local_irq_disable(); 1554 acpi_safe_halt(); 1555 local_irq_enable(); 1556 return 0; 1557 } 1558 } 1559 1560 local_irq_disable(); 1561 current_thread_info()->status &= ~TS_POLLING; 1562 /* 1563 * TS_POLLING-cleared state must be visible before we test 1564 * NEED_RESCHED: 1565 */ 1566 smp_mb(); 1567 1568 if (unlikely(need_resched())) { 1569 current_thread_info()->status |= TS_POLLING; 1570 local_irq_enable(); 1571 return 0; 1572 } 1573 1574 /* Tell the scheduler that we are going deep-idle: */ 1575 sched_clock_idle_sleep_event(); 1576 /* 1577 * Must be done before busmaster disable as we might need to 1578 * access HPET ! 1579 */ 1580 acpi_state_timer_broadcast(pr, cx, 1); 1581 1582 acpi_idle_update_bm_rld(pr, cx); 1583 1584 /* 1585 * disable bus master 1586 * bm_check implies we need ARB_DIS 1587 * !bm_check implies we need cache flush 1588 * bm_control implies whether we can do ARB_DIS 1589 * 1590 * That leaves a case where bm_check is set and bm_control is 1591 * not set. In that case we cannot do much, we enter C3 1592 * without doing anything. 1593 */ 1594 if (pr->flags.bm_check && pr->flags.bm_control) { 1595 spin_lock(&c3_lock); 1596 c3_cpu_count++; 1597 /* Disable bus master arbitration when all CPUs are in C3 */ 1598 if (c3_cpu_count == num_online_cpus()) 1599 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1); 1600 spin_unlock(&c3_lock); 1601 } else if (!pr->flags.bm_check) { 1602 ACPI_FLUSH_CPU_CACHE(); 1603 } 1604 1605 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1606 acpi_idle_do_entry(cx); 1607 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); 1608 1609 /* Re-enable bus master arbitration */ 1610 if (pr->flags.bm_check && pr->flags.bm_control) { 1611 spin_lock(&c3_lock); 1612 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0); 1613 c3_cpu_count--; 1614 spin_unlock(&c3_lock); 1615 } 1616 1617 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) 1618 /* TSC could halt in idle, so notify users */ 1619 if (tsc_halts_in_c(ACPI_STATE_C3)) 1620 mark_tsc_unstable("TSC halts in idle"); 1621 #endif 1622 sleep_ticks = ticks_elapsed(t1, t2); 1623 /* Tell the scheduler how much we idled: */ 1624 sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); 1625 1626 local_irq_enable(); 1627 current_thread_info()->status |= TS_POLLING; 1628 1629 cx->usage++; 1630 1631 acpi_state_timer_broadcast(pr, cx, 0); 1632 cx->time += sleep_ticks; 1633 return ticks_elapsed_in_us(t1, t2); 1634 } 1635 1636 struct cpuidle_driver acpi_idle_driver = { 1637 .name = "acpi_idle", 1638 .owner = THIS_MODULE, 1639 }; 1640 1641 /** 1642 * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE 1643 * @pr: the ACPI processor 1644 */ 1645 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) 1646 { 1647 int i, count = CPUIDLE_DRIVER_STATE_START; 1648 struct acpi_processor_cx *cx; 1649 struct cpuidle_state *state; 1650 struct cpuidle_device *dev = &pr->power.dev; 1651 1652 if (!pr->flags.power_setup_done) 1653 return -EINVAL; 1654 1655 if (pr->flags.power == 0) { 1656 return -EINVAL; 1657 } 1658 1659 for (i = 0; i < CPUIDLE_STATE_MAX; i++) { 1660 dev->states[i].name[0] = '\0'; 1661 dev->states[i].desc[0] = '\0'; 1662 } 1663 1664 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 1665 cx = &pr->power.states[i]; 1666 state = &dev->states[count]; 1667 1668 if (!cx->valid) 1669 continue; 1670 1671 #ifdef CONFIG_HOTPLUG_CPU 1672 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 1673 !pr->flags.has_cst && 1674 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 1675 continue; 1676 #endif 1677 cpuidle_set_statedata(state, cx); 1678 1679 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 1680 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 1681 state->exit_latency = cx->latency; 1682 state->target_residency = cx->latency * latency_factor; 1683 state->power_usage = cx->power; 1684 1685 state->flags = 0; 1686 switch (cx->type) { 1687 case ACPI_STATE_C1: 1688 state->flags |= CPUIDLE_FLAG_SHALLOW; 1689 state->flags |= CPUIDLE_FLAG_TIME_VALID; 1690 state->enter = acpi_idle_enter_c1; 1691 dev->safe_state = state; 1692 break; 1693 1694 case ACPI_STATE_C2: 1695 state->flags |= CPUIDLE_FLAG_BALANCED; 1696 state->flags |= CPUIDLE_FLAG_TIME_VALID; 1697 state->enter = acpi_idle_enter_simple; 1698 dev->safe_state = state; 1699 break; 1700 1701 case ACPI_STATE_C3: 1702 state->flags |= CPUIDLE_FLAG_DEEP; 1703 state->flags |= CPUIDLE_FLAG_TIME_VALID; 1704 state->flags |= CPUIDLE_FLAG_CHECK_BM; 1705 state->enter = pr->flags.bm_check ? 1706 acpi_idle_enter_bm : 1707 acpi_idle_enter_simple; 1708 break; 1709 } 1710 1711 count++; 1712 if (count == CPUIDLE_STATE_MAX) 1713 break; 1714 } 1715 1716 dev->state_count = count; 1717 1718 if (!count) 1719 return -EINVAL; 1720 1721 return 0; 1722 } 1723 1724 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 1725 { 1726 int ret; 1727 1728 if (!pr) 1729 return -EINVAL; 1730 1731 if (nocst) { 1732 return -ENODEV; 1733 } 1734 1735 if (!pr->flags.power_setup_done) 1736 return -ENODEV; 1737 1738 cpuidle_pause_and_lock(); 1739 cpuidle_disable_device(&pr->power.dev); 1740 acpi_processor_get_power_info(pr); 1741 acpi_processor_setup_cpuidle(pr); 1742 ret = cpuidle_enable_device(&pr->power.dev); 1743 cpuidle_resume_and_unlock(); 1744 1745 return ret; 1746 } 1747 1748 #endif /* CONFIG_CPU_IDLE */ 1749 1750 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, 1751 struct acpi_device *device) 1752 { 1753 acpi_status status = 0; 1754 static int first_run; 1755 struct proc_dir_entry *entry = NULL; 1756 unsigned int i; 1757 1758 1759 if (!first_run) { 1760 dmi_check_system(processor_power_dmi_table); 1761 max_cstate = acpi_processor_cstate_check(max_cstate); 1762 if (max_cstate < ACPI_C_STATES_MAX) 1763 printk(KERN_NOTICE 1764 "ACPI: processor limited to max C-state %d\n", 1765 max_cstate); 1766 first_run++; 1767 #if !defined(CONFIG_CPU_IDLE) && defined(CONFIG_SMP) 1768 pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, 1769 &acpi_processor_latency_notifier); 1770 #endif 1771 } 1772 1773 if (!pr) 1774 return -EINVAL; 1775 1776 if (acpi_gbl_FADT.cst_control && !nocst) { 1777 status = 1778 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8); 1779 if (ACPI_FAILURE(status)) { 1780 ACPI_EXCEPTION((AE_INFO, status, 1781 "Notifying BIOS of _CST ability failed")); 1782 } 1783 } 1784 1785 acpi_processor_get_power_info(pr); 1786 pr->flags.power_setup_done = 1; 1787 1788 /* 1789 * Install the idle handler if processor power management is supported. 1790 * Note that we use previously set idle handler will be used on 1791 * platforms that only support C1. 1792 */ 1793 if ((pr->flags.power) && (!boot_option_idle_override)) { 1794 #ifdef CONFIG_CPU_IDLE 1795 acpi_processor_setup_cpuidle(pr); 1796 pr->power.dev.cpu = pr->id; 1797 if (cpuidle_register_device(&pr->power.dev)) 1798 return -EIO; 1799 #endif 1800 1801 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id); 1802 for (i = 1; i <= pr->power.count; i++) 1803 if (pr->power.states[i].valid) 1804 printk(" C%d[C%d]", i, 1805 pr->power.states[i].type); 1806 printk(")\n"); 1807 1808 #ifndef CONFIG_CPU_IDLE 1809 if (pr->id == 0) { 1810 pm_idle_save = pm_idle; 1811 pm_idle = acpi_processor_idle; 1812 } 1813 #endif 1814 } 1815 1816 /* 'power' [R] */ 1817 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1818 S_IRUGO, acpi_device_dir(device)); 1819 if (!entry) 1820 return -EIO; 1821 else { 1822 entry->proc_fops = &acpi_processor_power_fops; 1823 entry->data = acpi_driver_data(device); 1824 entry->owner = THIS_MODULE; 1825 } 1826 1827 return 0; 1828 } 1829 1830 int acpi_processor_power_exit(struct acpi_processor *pr, 1831 struct acpi_device *device) 1832 { 1833 #ifdef CONFIG_CPU_IDLE 1834 if ((pr->flags.power) && (!boot_option_idle_override)) 1835 cpuidle_unregister_device(&pr->power.dev); 1836 #endif 1837 pr->flags.power_setup_done = 0; 1838 1839 if (acpi_device_dir(device)) 1840 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1841 acpi_device_dir(device)); 1842 1843 #ifndef CONFIG_CPU_IDLE 1844 1845 /* Unregister the idle handler when processor #0 is removed. */ 1846 if (pr->id == 0) { 1847 pm_idle = pm_idle_save; 1848 1849 /* 1850 * We are about to unload the current idle thread pm callback 1851 * (pm_idle), Wait for all processors to update cached/local 1852 * copies of pm_idle before proceeding. 1853 */ 1854 cpu_idle_wait(); 1855 #ifdef CONFIG_SMP 1856 pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY, 1857 &acpi_processor_latency_notifier); 1858 #endif 1859 } 1860 #endif 1861 1862 return 0; 1863 } 1864