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 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 42 #include <asm/io.h> 43 #include <asm/uaccess.h> 44 45 #include <acpi/acpi_bus.h> 46 #include <acpi/processor.h> 47 48 #define ACPI_PROCESSOR_COMPONENT 0x01000000 49 #define ACPI_PROCESSOR_CLASS "processor" 50 #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver" 51 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 52 ACPI_MODULE_NAME("acpi_processor") 53 #define ACPI_PROCESSOR_FILE_POWER "power" 54 #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000) 55 #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 56 #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */ 57 static void (*pm_idle_save) (void) __read_mostly; 58 module_param(max_cstate, uint, 0644); 59 60 static unsigned int nocst __read_mostly; 61 module_param(nocst, uint, 0000); 62 63 /* 64 * bm_history -- bit-mask with a bit per jiffy of bus-master activity 65 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms 66 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms 67 * 100 HZ: 0x0000000F: 4 jiffies = 40ms 68 * reduce history for more aggressive entry into C3 69 */ 70 static unsigned int bm_history __read_mostly = 71 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1)); 72 module_param(bm_history, uint, 0644); 73 /* -------------------------------------------------------------------------- 74 Power Management 75 -------------------------------------------------------------------------- */ 76 77 /* 78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 79 * For now disable this. Probably a bug somewhere else. 80 * 81 * To skip this limit, boot/load with a large max_cstate limit. 82 */ 83 static int set_max_cstate(struct dmi_system_id *id) 84 { 85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 86 return 0; 87 88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate." 89 " Override with \"processor.max_cstate=%d\"\n", id->ident, 90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 91 92 max_cstate = (long)id->driver_data; 93 94 return 0; 95 } 96 97 /* Actually this shouldn't be __cpuinitdata, would be better to fix the 98 callers to only run once -AK */ 99 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = { 100 { set_max_cstate, "IBM ThinkPad R40e", { 101 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 102 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1}, 103 { set_max_cstate, "IBM ThinkPad R40e", { 104 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 105 DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1}, 106 { set_max_cstate, "IBM ThinkPad R40e", { 107 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 108 DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1}, 109 { set_max_cstate, "IBM ThinkPad R40e", { 110 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 111 DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1}, 112 { set_max_cstate, "IBM ThinkPad R40e", { 113 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 114 DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1}, 115 { set_max_cstate, "IBM ThinkPad R40e", { 116 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 117 DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1}, 118 { set_max_cstate, "IBM ThinkPad R40e", { 119 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 120 DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1}, 121 { set_max_cstate, "IBM ThinkPad R40e", { 122 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 123 DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1}, 124 { set_max_cstate, "IBM ThinkPad R40e", { 125 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 126 DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1}, 127 { set_max_cstate, "IBM ThinkPad R40e", { 128 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 129 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1}, 130 { set_max_cstate, "IBM ThinkPad R40e", { 131 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 132 DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1}, 133 { set_max_cstate, "IBM ThinkPad R40e", { 134 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 135 DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1}, 136 { set_max_cstate, "IBM ThinkPad R40e", { 137 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 138 DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1}, 139 { set_max_cstate, "IBM ThinkPad R40e", { 140 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 141 DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1}, 142 { set_max_cstate, "IBM ThinkPad R40e", { 143 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"), 144 DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1}, 145 { set_max_cstate, "Medion 41700", { 146 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 147 DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1}, 148 { set_max_cstate, "Clevo 5600D", { 149 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 150 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 151 (void *)2}, 152 {}, 153 }; 154 155 static inline u32 ticks_elapsed(u32 t1, u32 t2) 156 { 157 if (t2 >= t1) 158 return (t2 - t1); 159 else if (!acpi_fadt.tmr_val_ext) 160 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF); 161 else 162 return ((0xFFFFFFFF - t1) + t2); 163 } 164 165 static void 166 acpi_processor_power_activate(struct acpi_processor *pr, 167 struct acpi_processor_cx *new) 168 { 169 struct acpi_processor_cx *old; 170 171 if (!pr || !new) 172 return; 173 174 old = pr->power.state; 175 176 if (old) 177 old->promotion.count = 0; 178 new->demotion.count = 0; 179 180 /* Cleanup from old state. */ 181 if (old) { 182 switch (old->type) { 183 case ACPI_STATE_C3: 184 /* Disable bus master reload */ 185 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check) 186 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, 187 ACPI_MTX_DO_NOT_LOCK); 188 break; 189 } 190 } 191 192 /* Prepare to use new state. */ 193 switch (new->type) { 194 case ACPI_STATE_C3: 195 /* Enable bus master reload */ 196 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check) 197 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, 198 ACPI_MTX_DO_NOT_LOCK); 199 break; 200 } 201 202 pr->power.state = new; 203 204 return; 205 } 206 207 static void acpi_safe_halt(void) 208 { 209 current_thread_info()->status &= ~TS_POLLING; 210 smp_mb__after_clear_bit(); 211 if (!need_resched()) 212 safe_halt(); 213 current_thread_info()->status |= TS_POLLING; 214 } 215 216 static atomic_t c3_cpu_count; 217 218 static void acpi_processor_idle(void) 219 { 220 struct acpi_processor *pr = NULL; 221 struct acpi_processor_cx *cx = NULL; 222 struct acpi_processor_cx *next_state = NULL; 223 int sleep_ticks = 0; 224 u32 t1, t2 = 0; 225 226 pr = processors[smp_processor_id()]; 227 if (!pr) 228 return; 229 230 /* 231 * Interrupts must be disabled during bus mastering calculations and 232 * for C2/C3 transitions. 233 */ 234 local_irq_disable(); 235 236 /* 237 * Check whether we truly need to go idle, or should 238 * reschedule: 239 */ 240 if (unlikely(need_resched())) { 241 local_irq_enable(); 242 return; 243 } 244 245 cx = pr->power.state; 246 if (!cx) { 247 if (pm_idle_save) 248 pm_idle_save(); 249 else 250 acpi_safe_halt(); 251 return; 252 } 253 254 /* 255 * Check BM Activity 256 * ----------------- 257 * Check for bus mastering activity (if required), record, and check 258 * for demotion. 259 */ 260 if (pr->flags.bm_check) { 261 u32 bm_status = 0; 262 unsigned long diff = jiffies - pr->power.bm_check_timestamp; 263 264 if (diff > 32) 265 diff = 32; 266 267 while (diff) { 268 /* if we didn't get called, assume there was busmaster activity */ 269 diff--; 270 if (diff) 271 pr->power.bm_activity |= 0x1; 272 pr->power.bm_activity <<= 1; 273 } 274 275 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, 276 &bm_status, ACPI_MTX_DO_NOT_LOCK); 277 if (bm_status) { 278 pr->power.bm_activity++; 279 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 280 1, ACPI_MTX_DO_NOT_LOCK); 281 } 282 /* 283 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 284 * the true state of bus mastering activity; forcing us to 285 * manually check the BMIDEA bit of each IDE channel. 286 */ 287 else if (errata.piix4.bmisx) { 288 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 289 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 290 pr->power.bm_activity++; 291 } 292 293 pr->power.bm_check_timestamp = jiffies; 294 295 /* 296 * Apply bus mastering demotion policy. Automatically demote 297 * to avoid a faulty transition. Note that the processor 298 * won't enter a low-power state during this call (to this 299 * funciton) but should upon the next. 300 * 301 * TBD: A better policy might be to fallback to the demotion 302 * state (use it for this quantum only) istead of 303 * demoting -- and rely on duration as our sole demotion 304 * qualification. This may, however, introduce DMA 305 * issues (e.g. floppy DMA transfer overrun/underrun). 306 */ 307 if (pr->power.bm_activity & cx->demotion.threshold.bm) { 308 local_irq_enable(); 309 next_state = cx->demotion.state; 310 goto end; 311 } 312 } 313 314 #ifdef CONFIG_HOTPLUG_CPU 315 /* 316 * Check for P_LVL2_UP flag before entering C2 and above on 317 * an SMP system. We do it here instead of doing it at _CST/P_LVL 318 * detection phase, to work cleanly with logical CPU hotplug. 319 */ 320 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 321 !pr->flags.has_cst && !acpi_fadt.plvl2_up) 322 cx = &pr->power.states[ACPI_STATE_C1]; 323 #endif 324 325 cx->usage++; 326 327 /* 328 * Sleep: 329 * ------ 330 * Invoke the current Cx state to put the processor to sleep. 331 */ 332 if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) { 333 current_thread_info()->status &= ~TS_POLLING; 334 smp_mb__after_clear_bit(); 335 if (need_resched()) { 336 current_thread_info()->status |= TS_POLLING; 337 local_irq_enable(); 338 return; 339 } 340 } 341 342 switch (cx->type) { 343 344 case ACPI_STATE_C1: 345 /* 346 * Invoke C1. 347 * Use the appropriate idle routine, the one that would 348 * be used without acpi C-states. 349 */ 350 if (pm_idle_save) 351 pm_idle_save(); 352 else 353 acpi_safe_halt(); 354 355 /* 356 * TBD: Can't get time duration while in C1, as resumes 357 * go to an ISR rather than here. Need to instrument 358 * base interrupt handler. 359 */ 360 sleep_ticks = 0xFFFFFFFF; 361 break; 362 363 case ACPI_STATE_C2: 364 /* Get start time (ticks) */ 365 t1 = inl(acpi_fadt.xpm_tmr_blk.address); 366 /* Invoke C2 */ 367 inb(cx->address); 368 /* Dummy op - must do something useless after P_LVL2 read */ 369 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 370 /* Get end time (ticks) */ 371 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 372 373 #ifdef CONFIG_GENERIC_TIME 374 /* TSC halts in C2, so notify users */ 375 mark_tsc_unstable(); 376 #endif 377 /* Re-enable interrupts */ 378 local_irq_enable(); 379 current_thread_info()->status |= TS_POLLING; 380 /* Compute time (ticks) that we were actually asleep */ 381 sleep_ticks = 382 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; 383 break; 384 385 case ACPI_STATE_C3: 386 387 if (pr->flags.bm_check) { 388 if (atomic_inc_return(&c3_cpu_count) == 389 num_online_cpus()) { 390 /* 391 * All CPUs are trying to go to C3 392 * Disable bus master arbitration 393 */ 394 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, 395 ACPI_MTX_DO_NOT_LOCK); 396 } 397 } else { 398 /* SMP with no shared cache... Invalidate cache */ 399 ACPI_FLUSH_CPU_CACHE(); 400 } 401 402 /* Get start time (ticks) */ 403 t1 = inl(acpi_fadt.xpm_tmr_blk.address); 404 /* Invoke C3 */ 405 inb(cx->address); 406 /* Dummy op - must do something useless after P_LVL3 read */ 407 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 408 /* Get end time (ticks) */ 409 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 410 if (pr->flags.bm_check) { 411 /* Enable bus master arbitration */ 412 atomic_dec(&c3_cpu_count); 413 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, 414 ACPI_MTX_DO_NOT_LOCK); 415 } 416 417 #ifdef CONFIG_GENERIC_TIME 418 /* TSC halts in C3, so notify users */ 419 mark_tsc_unstable(); 420 #endif 421 /* Re-enable interrupts */ 422 local_irq_enable(); 423 current_thread_info()->status |= TS_POLLING; 424 /* Compute time (ticks) that we were actually asleep */ 425 sleep_ticks = 426 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; 427 break; 428 429 default: 430 local_irq_enable(); 431 return; 432 } 433 434 next_state = pr->power.state; 435 436 #ifdef CONFIG_HOTPLUG_CPU 437 /* Don't do promotion/demotion */ 438 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) && 439 !pr->flags.has_cst && !acpi_fadt.plvl2_up) { 440 next_state = cx; 441 goto end; 442 } 443 #endif 444 445 /* 446 * Promotion? 447 * ---------- 448 * Track the number of longs (time asleep is greater than threshold) 449 * and promote when the count threshold is reached. Note that bus 450 * mastering activity may prevent promotions. 451 * Do not promote above max_cstate. 452 */ 453 if (cx->promotion.state && 454 ((cx->promotion.state - pr->power.states) <= max_cstate)) { 455 if (sleep_ticks > cx->promotion.threshold.ticks) { 456 cx->promotion.count++; 457 cx->demotion.count = 0; 458 if (cx->promotion.count >= 459 cx->promotion.threshold.count) { 460 if (pr->flags.bm_check) { 461 if (! 462 (pr->power.bm_activity & cx-> 463 promotion.threshold.bm)) { 464 next_state = 465 cx->promotion.state; 466 goto end; 467 } 468 } else { 469 next_state = cx->promotion.state; 470 goto end; 471 } 472 } 473 } 474 } 475 476 /* 477 * Demotion? 478 * --------- 479 * Track the number of shorts (time asleep is less than time threshold) 480 * and demote when the usage threshold is reached. 481 */ 482 if (cx->demotion.state) { 483 if (sleep_ticks < cx->demotion.threshold.ticks) { 484 cx->demotion.count++; 485 cx->promotion.count = 0; 486 if (cx->demotion.count >= cx->demotion.threshold.count) { 487 next_state = cx->demotion.state; 488 goto end; 489 } 490 } 491 } 492 493 end: 494 /* 495 * Demote if current state exceeds max_cstate 496 */ 497 if ((pr->power.state - pr->power.states) > max_cstate) { 498 if (cx->demotion.state) 499 next_state = cx->demotion.state; 500 } 501 502 /* 503 * New Cx State? 504 * ------------- 505 * If we're going to start using a new Cx state we must clean up 506 * from the previous and prepare to use the new. 507 */ 508 if (next_state != pr->power.state) 509 acpi_processor_power_activate(pr, next_state); 510 } 511 512 static int acpi_processor_set_power_policy(struct acpi_processor *pr) 513 { 514 unsigned int i; 515 unsigned int state_is_set = 0; 516 struct acpi_processor_cx *lower = NULL; 517 struct acpi_processor_cx *higher = NULL; 518 struct acpi_processor_cx *cx; 519 520 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy"); 521 522 if (!pr) 523 return_VALUE(-EINVAL); 524 525 /* 526 * This function sets the default Cx state policy (OS idle handler). 527 * Our scheme is to promote quickly to C2 but more conservatively 528 * to C3. We're favoring C2 for its characteristics of low latency 529 * (quick response), good power savings, and ability to allow bus 530 * mastering activity. Note that the Cx state policy is completely 531 * customizable and can be altered dynamically. 532 */ 533 534 /* startup state */ 535 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 536 cx = &pr->power.states[i]; 537 if (!cx->valid) 538 continue; 539 540 if (!state_is_set) 541 pr->power.state = cx; 542 state_is_set++; 543 break; 544 } 545 546 if (!state_is_set) 547 return_VALUE(-ENODEV); 548 549 /* demotion */ 550 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 551 cx = &pr->power.states[i]; 552 if (!cx->valid) 553 continue; 554 555 if (lower) { 556 cx->demotion.state = lower; 557 cx->demotion.threshold.ticks = cx->latency_ticks; 558 cx->demotion.threshold.count = 1; 559 if (cx->type == ACPI_STATE_C3) 560 cx->demotion.threshold.bm = bm_history; 561 } 562 563 lower = cx; 564 } 565 566 /* promotion */ 567 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) { 568 cx = &pr->power.states[i]; 569 if (!cx->valid) 570 continue; 571 572 if (higher) { 573 cx->promotion.state = higher; 574 cx->promotion.threshold.ticks = cx->latency_ticks; 575 if (cx->type >= ACPI_STATE_C2) 576 cx->promotion.threshold.count = 4; 577 else 578 cx->promotion.threshold.count = 10; 579 if (higher->type == ACPI_STATE_C3) 580 cx->promotion.threshold.bm = bm_history; 581 } 582 583 higher = cx; 584 } 585 586 return_VALUE(0); 587 } 588 589 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 590 { 591 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt"); 592 593 if (!pr) 594 return_VALUE(-EINVAL); 595 596 if (!pr->pblk) 597 return_VALUE(-ENODEV); 598 599 /* if info is obtained from pblk/fadt, type equals state */ 600 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 601 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 602 603 #ifndef CONFIG_HOTPLUG_CPU 604 /* 605 * Check for P_LVL2_UP flag before entering C2 and above on 606 * an SMP system. 607 */ 608 if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up) 609 return_VALUE(-ENODEV); 610 #endif 611 612 /* determine C2 and C3 address from pblk */ 613 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 614 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 615 616 /* determine latencies from FADT */ 617 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat; 618 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat; 619 620 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 621 "lvl2[0x%08x] lvl3[0x%08x]\n", 622 pr->power.states[ACPI_STATE_C2].address, 623 pr->power.states[ACPI_STATE_C3].address)); 624 625 return_VALUE(0); 626 } 627 628 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr) 629 { 630 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1"); 631 632 /* Zero initialize all the C-states info. */ 633 memset(pr->power.states, 0, sizeof(pr->power.states)); 634 635 /* set the first C-State to C1 */ 636 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 637 638 /* the C0 state only exists as a filler in our array, 639 * and all processors need to support C1 */ 640 pr->power.states[ACPI_STATE_C0].valid = 1; 641 pr->power.states[ACPI_STATE_C1].valid = 1; 642 643 return_VALUE(0); 644 } 645 646 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 647 { 648 acpi_status status = 0; 649 acpi_integer count; 650 int current_count; 651 int i; 652 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 653 union acpi_object *cst; 654 655 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst"); 656 657 if (nocst) 658 return_VALUE(-ENODEV); 659 660 current_count = 1; 661 662 /* Zero initialize C2 onwards and prepare for fresh CST lookup */ 663 for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++) 664 memset(&(pr->power.states[i]), 0, 665 sizeof(struct acpi_processor_cx)); 666 667 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 668 if (ACPI_FAILURE(status)) { 669 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 670 return_VALUE(-ENODEV); 671 } 672 673 cst = (union acpi_object *)buffer.pointer; 674 675 /* There must be at least 2 elements */ 676 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 677 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 678 "not enough elements in _CST\n")); 679 status = -EFAULT; 680 goto end; 681 } 682 683 count = cst->package.elements[0].integer.value; 684 685 /* Validate number of power states. */ 686 if (count < 1 || count != cst->package.count - 1) { 687 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 688 "count given by _CST is not valid\n")); 689 status = -EFAULT; 690 goto end; 691 } 692 693 /* Tell driver that at least _CST is supported. */ 694 pr->flags.has_cst = 1; 695 696 for (i = 1; i <= count; i++) { 697 union acpi_object *element; 698 union acpi_object *obj; 699 struct acpi_power_register *reg; 700 struct acpi_processor_cx cx; 701 702 memset(&cx, 0, sizeof(cx)); 703 704 element = (union acpi_object *)&(cst->package.elements[i]); 705 if (element->type != ACPI_TYPE_PACKAGE) 706 continue; 707 708 if (element->package.count != 4) 709 continue; 710 711 obj = (union acpi_object *)&(element->package.elements[0]); 712 713 if (obj->type != ACPI_TYPE_BUFFER) 714 continue; 715 716 reg = (struct acpi_power_register *)obj->buffer.pointer; 717 718 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 719 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 720 continue; 721 722 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ? 723 0 : reg->address; 724 725 /* There should be an easy way to extract an integer... */ 726 obj = (union acpi_object *)&(element->package.elements[1]); 727 if (obj->type != ACPI_TYPE_INTEGER) 728 continue; 729 730 cx.type = obj->integer.value; 731 732 if ((cx.type != ACPI_STATE_C1) && 733 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) 734 continue; 735 736 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3)) 737 continue; 738 739 obj = (union acpi_object *)&(element->package.elements[2]); 740 if (obj->type != ACPI_TYPE_INTEGER) 741 continue; 742 743 cx.latency = obj->integer.value; 744 745 obj = (union acpi_object *)&(element->package.elements[3]); 746 if (obj->type != ACPI_TYPE_INTEGER) 747 continue; 748 749 cx.power = obj->integer.value; 750 751 current_count++; 752 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 753 754 /* 755 * We support total ACPI_PROCESSOR_MAX_POWER - 1 756 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 757 */ 758 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 759 printk(KERN_WARNING 760 "Limiting number of power states to max (%d)\n", 761 ACPI_PROCESSOR_MAX_POWER); 762 printk(KERN_WARNING 763 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 764 break; 765 } 766 } 767 768 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 769 current_count)); 770 771 /* Validate number of power states discovered */ 772 if (current_count < 2) 773 status = -EFAULT; 774 775 end: 776 acpi_os_free(buffer.pointer); 777 778 return_VALUE(status); 779 } 780 781 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) 782 { 783 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2"); 784 785 if (!cx->address) 786 return_VOID; 787 788 /* 789 * C2 latency must be less than or equal to 100 790 * microseconds. 791 */ 792 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 793 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 794 "latency too large [%d]\n", cx->latency)); 795 return_VOID; 796 } 797 798 /* 799 * Otherwise we've met all of our C2 requirements. 800 * Normalize the C2 latency to expidite policy 801 */ 802 cx->valid = 1; 803 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 804 805 return_VOID; 806 } 807 808 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 809 struct acpi_processor_cx *cx) 810 { 811 static int bm_check_flag; 812 813 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3"); 814 815 if (!cx->address) 816 return_VOID; 817 818 /* 819 * C3 latency must be less than or equal to 1000 820 * microseconds. 821 */ 822 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 823 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 824 "latency too large [%d]\n", cx->latency)); 825 return_VOID; 826 } 827 828 /* 829 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 830 * DMA transfers are used by any ISA device to avoid livelock. 831 * Note that we could disable Type-F DMA (as recommended by 832 * the erratum), but this is known to disrupt certain ISA 833 * devices thus we take the conservative approach. 834 */ 835 else if (errata.piix4.fdma) { 836 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 837 "C3 not supported on PIIX4 with Type-F DMA\n")); 838 return_VOID; 839 } 840 841 /* All the logic here assumes flags.bm_check is same across all CPUs */ 842 if (!bm_check_flag) { 843 /* Determine whether bm_check is needed based on CPU */ 844 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 845 bm_check_flag = pr->flags.bm_check; 846 } else { 847 pr->flags.bm_check = bm_check_flag; 848 } 849 850 if (pr->flags.bm_check) { 851 /* bus mastering control is necessary */ 852 if (!pr->flags.bm_control) { 853 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 854 "C3 support requires bus mastering control\n")); 855 return_VOID; 856 } 857 } else { 858 /* 859 * WBINVD should be set in fadt, for C3 state to be 860 * supported on when bm_check is not required. 861 */ 862 if (acpi_fadt.wb_invd != 1) { 863 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 864 "Cache invalidation should work properly" 865 " for C3 to be enabled on SMP systems\n")); 866 return_VOID; 867 } 868 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 869 0, ACPI_MTX_DO_NOT_LOCK); 870 } 871 872 /* 873 * Otherwise we've met all of our C3 requirements. 874 * Normalize the C3 latency to expidite policy. Enable 875 * checking of bus mastering status (bm_check) so we can 876 * use this in our C3 policy 877 */ 878 cx->valid = 1; 879 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 880 881 return_VOID; 882 } 883 884 static int acpi_processor_power_verify(struct acpi_processor *pr) 885 { 886 unsigned int i; 887 unsigned int working = 0; 888 889 #ifdef ARCH_APICTIMER_STOPS_ON_C3 890 int timer_broadcast = 0; 891 cpumask_t mask = cpumask_of_cpu(pr->id); 892 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1); 893 #endif 894 895 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 896 struct acpi_processor_cx *cx = &pr->power.states[i]; 897 898 switch (cx->type) { 899 case ACPI_STATE_C1: 900 cx->valid = 1; 901 break; 902 903 case ACPI_STATE_C2: 904 acpi_processor_power_verify_c2(cx); 905 #ifdef ARCH_APICTIMER_STOPS_ON_C3 906 /* Some AMD systems fake C3 as C2, but still 907 have timer troubles */ 908 if (cx->valid && 909 boot_cpu_data.x86_vendor == X86_VENDOR_AMD) 910 timer_broadcast++; 911 #endif 912 break; 913 914 case ACPI_STATE_C3: 915 acpi_processor_power_verify_c3(pr, cx); 916 #ifdef ARCH_APICTIMER_STOPS_ON_C3 917 if (cx->valid) 918 timer_broadcast++; 919 #endif 920 break; 921 } 922 923 if (cx->valid) 924 working++; 925 } 926 927 #ifdef ARCH_APICTIMER_STOPS_ON_C3 928 if (timer_broadcast) 929 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1); 930 #endif 931 932 return (working); 933 } 934 935 static int acpi_processor_get_power_info(struct acpi_processor *pr) 936 { 937 unsigned int i; 938 int result; 939 940 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info"); 941 942 /* NOTE: the idle thread may not be running while calling 943 * this function */ 944 945 /* Adding C1 state */ 946 acpi_processor_get_power_info_default_c1(pr); 947 result = acpi_processor_get_power_info_cst(pr); 948 if (result == -ENODEV) 949 acpi_processor_get_power_info_fadt(pr); 950 951 pr->power.count = acpi_processor_power_verify(pr); 952 953 /* 954 * Set Default Policy 955 * ------------------ 956 * Now that we know which states are supported, set the default 957 * policy. Note that this policy can be changed dynamically 958 * (e.g. encourage deeper sleeps to conserve battery life when 959 * not on AC). 960 */ 961 result = acpi_processor_set_power_policy(pr); 962 if (result) 963 return_VALUE(result); 964 965 /* 966 * if one state of type C2 or C3 is available, mark this 967 * CPU as being "idle manageable" 968 */ 969 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 970 if (pr->power.states[i].valid) { 971 pr->power.count = i; 972 if (pr->power.states[i].type >= ACPI_STATE_C2) 973 pr->flags.power = 1; 974 } 975 } 976 977 return_VALUE(0); 978 } 979 980 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 981 { 982 int result = 0; 983 984 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed"); 985 986 if (!pr) 987 return_VALUE(-EINVAL); 988 989 if (nocst) { 990 return_VALUE(-ENODEV); 991 } 992 993 if (!pr->flags.power_setup_done) 994 return_VALUE(-ENODEV); 995 996 /* Fall back to the default idle loop */ 997 pm_idle = pm_idle_save; 998 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */ 999 1000 pr->flags.power = 0; 1001 result = acpi_processor_get_power_info(pr); 1002 if ((pr->flags.power == 1) && (pr->flags.power_setup_done)) 1003 pm_idle = acpi_processor_idle; 1004 1005 return_VALUE(result); 1006 } 1007 1008 /* proc interface */ 1009 1010 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) 1011 { 1012 struct acpi_processor *pr = (struct acpi_processor *)seq->private; 1013 unsigned int i; 1014 1015 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show"); 1016 1017 if (!pr) 1018 goto end; 1019 1020 seq_printf(seq, "active state: C%zd\n" 1021 "max_cstate: C%d\n" 1022 "bus master activity: %08x\n", 1023 pr->power.state ? pr->power.state - pr->power.states : 0, 1024 max_cstate, (unsigned)pr->power.bm_activity); 1025 1026 seq_puts(seq, "states:\n"); 1027 1028 for (i = 1; i <= pr->power.count; i++) { 1029 seq_printf(seq, " %cC%d: ", 1030 (&pr->power.states[i] == 1031 pr->power.state ? '*' : ' '), i); 1032 1033 if (!pr->power.states[i].valid) { 1034 seq_puts(seq, "<not supported>\n"); 1035 continue; 1036 } 1037 1038 switch (pr->power.states[i].type) { 1039 case ACPI_STATE_C1: 1040 seq_printf(seq, "type[C1] "); 1041 break; 1042 case ACPI_STATE_C2: 1043 seq_printf(seq, "type[C2] "); 1044 break; 1045 case ACPI_STATE_C3: 1046 seq_printf(seq, "type[C3] "); 1047 break; 1048 default: 1049 seq_printf(seq, "type[--] "); 1050 break; 1051 } 1052 1053 if (pr->power.states[i].promotion.state) 1054 seq_printf(seq, "promotion[C%zd] ", 1055 (pr->power.states[i].promotion.state - 1056 pr->power.states)); 1057 else 1058 seq_puts(seq, "promotion[--] "); 1059 1060 if (pr->power.states[i].demotion.state) 1061 seq_printf(seq, "demotion[C%zd] ", 1062 (pr->power.states[i].demotion.state - 1063 pr->power.states)); 1064 else 1065 seq_puts(seq, "demotion[--] "); 1066 1067 seq_printf(seq, "latency[%03d] usage[%08d]\n", 1068 pr->power.states[i].latency, 1069 pr->power.states[i].usage); 1070 } 1071 1072 end: 1073 return_VALUE(0); 1074 } 1075 1076 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file) 1077 { 1078 return single_open(file, acpi_processor_power_seq_show, 1079 PDE(inode)->data); 1080 } 1081 1082 static struct file_operations acpi_processor_power_fops = { 1083 .open = acpi_processor_power_open_fs, 1084 .read = seq_read, 1085 .llseek = seq_lseek, 1086 .release = single_release, 1087 }; 1088 1089 int acpi_processor_power_init(struct acpi_processor *pr, 1090 struct acpi_device *device) 1091 { 1092 acpi_status status = 0; 1093 static int first_run; 1094 struct proc_dir_entry *entry = NULL; 1095 unsigned int i; 1096 1097 ACPI_FUNCTION_TRACE("acpi_processor_power_init"); 1098 1099 if (!first_run) { 1100 dmi_check_system(processor_power_dmi_table); 1101 if (max_cstate < ACPI_C_STATES_MAX) 1102 printk(KERN_NOTICE 1103 "ACPI: processor limited to max C-state %d\n", 1104 max_cstate); 1105 first_run++; 1106 } 1107 1108 if (!pr) 1109 return_VALUE(-EINVAL); 1110 1111 if (acpi_fadt.cst_cnt && !nocst) { 1112 status = 1113 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8); 1114 if (ACPI_FAILURE(status)) { 1115 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 1116 "Notifying BIOS of _CST ability failed\n")); 1117 } 1118 } 1119 1120 acpi_processor_get_power_info(pr); 1121 1122 /* 1123 * Install the idle handler if processor power management is supported. 1124 * Note that we use previously set idle handler will be used on 1125 * platforms that only support C1. 1126 */ 1127 if ((pr->flags.power) && (!boot_option_idle_override)) { 1128 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id); 1129 for (i = 1; i <= pr->power.count; i++) 1130 if (pr->power.states[i].valid) 1131 printk(" C%d[C%d]", i, 1132 pr->power.states[i].type); 1133 printk(")\n"); 1134 1135 if (pr->id == 0) { 1136 pm_idle_save = pm_idle; 1137 pm_idle = acpi_processor_idle; 1138 } 1139 } 1140 1141 /* 'power' [R] */ 1142 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1143 S_IRUGO, acpi_device_dir(device)); 1144 if (!entry) 1145 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 1146 "Unable to create '%s' fs entry\n", 1147 ACPI_PROCESSOR_FILE_POWER)); 1148 else { 1149 entry->proc_fops = &acpi_processor_power_fops; 1150 entry->data = acpi_driver_data(device); 1151 entry->owner = THIS_MODULE; 1152 } 1153 1154 pr->flags.power_setup_done = 1; 1155 1156 return_VALUE(0); 1157 } 1158 1159 int acpi_processor_power_exit(struct acpi_processor *pr, 1160 struct acpi_device *device) 1161 { 1162 ACPI_FUNCTION_TRACE("acpi_processor_power_exit"); 1163 1164 pr->flags.power_setup_done = 0; 1165 1166 if (acpi_device_dir(device)) 1167 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1168 acpi_device_dir(device)); 1169 1170 /* Unregister the idle handler when processor #0 is removed. */ 1171 if (pr->id == 0) { 1172 pm_idle = pm_idle_save; 1173 1174 /* 1175 * We are about to unload the current idle thread pm callback 1176 * (pm_idle), Wait for all processors to update cached/local 1177 * copies of pm_idle before proceeding. 1178 */ 1179 cpu_idle_wait(); 1180 } 1181 1182 return_VALUE(0); 1183 } 1184