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); 58 module_param(max_cstate, uint, 0644); 59 60 static unsigned int nocst = 0; 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 = 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 clear_thread_flag(TIF_POLLING_NRFLAG); 210 smp_mb__after_clear_bit(); 211 if (!need_resched()) 212 safe_halt(); 213 set_thread_flag(TIF_POLLING_NRFLAG); 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 clear_thread_flag(TIF_POLLING_NRFLAG); 334 smp_mb__after_clear_bit(); 335 if (need_resched()) { 336 set_thread_flag(TIF_POLLING_NRFLAG); 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 /* Re-enable interrupts */ 373 local_irq_enable(); 374 set_thread_flag(TIF_POLLING_NRFLAG); 375 /* Compute time (ticks) that we were actually asleep */ 376 sleep_ticks = 377 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; 378 break; 379 380 case ACPI_STATE_C3: 381 382 if (pr->flags.bm_check) { 383 if (atomic_inc_return(&c3_cpu_count) == 384 num_online_cpus()) { 385 /* 386 * All CPUs are trying to go to C3 387 * Disable bus master arbitration 388 */ 389 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, 390 ACPI_MTX_DO_NOT_LOCK); 391 } 392 } else { 393 /* SMP with no shared cache... Invalidate cache */ 394 ACPI_FLUSH_CPU_CACHE(); 395 } 396 397 /* Get start time (ticks) */ 398 t1 = inl(acpi_fadt.xpm_tmr_blk.address); 399 /* Invoke C3 */ 400 inb(cx->address); 401 /* Dummy op - must do something useless after P_LVL3 read */ 402 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 403 /* Get end time (ticks) */ 404 t2 = inl(acpi_fadt.xpm_tmr_blk.address); 405 if (pr->flags.bm_check) { 406 /* Enable bus master arbitration */ 407 atomic_dec(&c3_cpu_count); 408 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, 409 ACPI_MTX_DO_NOT_LOCK); 410 } 411 412 /* Re-enable interrupts */ 413 local_irq_enable(); 414 set_thread_flag(TIF_POLLING_NRFLAG); 415 /* Compute time (ticks) that we were actually asleep */ 416 sleep_ticks = 417 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; 418 break; 419 420 default: 421 local_irq_enable(); 422 return; 423 } 424 425 next_state = pr->power.state; 426 427 #ifdef CONFIG_HOTPLUG_CPU 428 /* Don't do promotion/demotion */ 429 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) && 430 !pr->flags.has_cst && !acpi_fadt.plvl2_up) { 431 next_state = cx; 432 goto end; 433 } 434 #endif 435 436 /* 437 * Promotion? 438 * ---------- 439 * Track the number of longs (time asleep is greater than threshold) 440 * and promote when the count threshold is reached. Note that bus 441 * mastering activity may prevent promotions. 442 * Do not promote above max_cstate. 443 */ 444 if (cx->promotion.state && 445 ((cx->promotion.state - pr->power.states) <= max_cstate)) { 446 if (sleep_ticks > cx->promotion.threshold.ticks) { 447 cx->promotion.count++; 448 cx->demotion.count = 0; 449 if (cx->promotion.count >= 450 cx->promotion.threshold.count) { 451 if (pr->flags.bm_check) { 452 if (! 453 (pr->power.bm_activity & cx-> 454 promotion.threshold.bm)) { 455 next_state = 456 cx->promotion.state; 457 goto end; 458 } 459 } else { 460 next_state = cx->promotion.state; 461 goto end; 462 } 463 } 464 } 465 } 466 467 /* 468 * Demotion? 469 * --------- 470 * Track the number of shorts (time asleep is less than time threshold) 471 * and demote when the usage threshold is reached. 472 */ 473 if (cx->demotion.state) { 474 if (sleep_ticks < cx->demotion.threshold.ticks) { 475 cx->demotion.count++; 476 cx->promotion.count = 0; 477 if (cx->demotion.count >= cx->demotion.threshold.count) { 478 next_state = cx->demotion.state; 479 goto end; 480 } 481 } 482 } 483 484 end: 485 /* 486 * Demote if current state exceeds max_cstate 487 */ 488 if ((pr->power.state - pr->power.states) > max_cstate) { 489 if (cx->demotion.state) 490 next_state = cx->demotion.state; 491 } 492 493 /* 494 * New Cx State? 495 * ------------- 496 * If we're going to start using a new Cx state we must clean up 497 * from the previous and prepare to use the new. 498 */ 499 if (next_state != pr->power.state) 500 acpi_processor_power_activate(pr, next_state); 501 } 502 503 static int acpi_processor_set_power_policy(struct acpi_processor *pr) 504 { 505 unsigned int i; 506 unsigned int state_is_set = 0; 507 struct acpi_processor_cx *lower = NULL; 508 struct acpi_processor_cx *higher = NULL; 509 struct acpi_processor_cx *cx; 510 511 ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy"); 512 513 if (!pr) 514 return_VALUE(-EINVAL); 515 516 /* 517 * This function sets the default Cx state policy (OS idle handler). 518 * Our scheme is to promote quickly to C2 but more conservatively 519 * to C3. We're favoring C2 for its characteristics of low latency 520 * (quick response), good power savings, and ability to allow bus 521 * mastering activity. Note that the Cx state policy is completely 522 * customizable and can be altered dynamically. 523 */ 524 525 /* startup state */ 526 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 527 cx = &pr->power.states[i]; 528 if (!cx->valid) 529 continue; 530 531 if (!state_is_set) 532 pr->power.state = cx; 533 state_is_set++; 534 break; 535 } 536 537 if (!state_is_set) 538 return_VALUE(-ENODEV); 539 540 /* demotion */ 541 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 542 cx = &pr->power.states[i]; 543 if (!cx->valid) 544 continue; 545 546 if (lower) { 547 cx->demotion.state = lower; 548 cx->demotion.threshold.ticks = cx->latency_ticks; 549 cx->demotion.threshold.count = 1; 550 if (cx->type == ACPI_STATE_C3) 551 cx->demotion.threshold.bm = bm_history; 552 } 553 554 lower = cx; 555 } 556 557 /* promotion */ 558 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) { 559 cx = &pr->power.states[i]; 560 if (!cx->valid) 561 continue; 562 563 if (higher) { 564 cx->promotion.state = higher; 565 cx->promotion.threshold.ticks = cx->latency_ticks; 566 if (cx->type >= ACPI_STATE_C2) 567 cx->promotion.threshold.count = 4; 568 else 569 cx->promotion.threshold.count = 10; 570 if (higher->type == ACPI_STATE_C3) 571 cx->promotion.threshold.bm = bm_history; 572 } 573 574 higher = cx; 575 } 576 577 return_VALUE(0); 578 } 579 580 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 581 { 582 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt"); 583 584 if (!pr) 585 return_VALUE(-EINVAL); 586 587 if (!pr->pblk) 588 return_VALUE(-ENODEV); 589 590 /* if info is obtained from pblk/fadt, type equals state */ 591 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 592 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 593 594 #ifndef CONFIG_HOTPLUG_CPU 595 /* 596 * Check for P_LVL2_UP flag before entering C2 and above on 597 * an SMP system. 598 */ 599 if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up) 600 return_VALUE(-ENODEV); 601 #endif 602 603 /* determine C2 and C3 address from pblk */ 604 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 605 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 606 607 /* determine latencies from FADT */ 608 pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat; 609 pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat; 610 611 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 612 "lvl2[0x%08x] lvl3[0x%08x]\n", 613 pr->power.states[ACPI_STATE_C2].address, 614 pr->power.states[ACPI_STATE_C3].address)); 615 616 return_VALUE(0); 617 } 618 619 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr) 620 { 621 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1"); 622 623 /* Zero initialize all the C-states info. */ 624 memset(pr->power.states, 0, sizeof(pr->power.states)); 625 626 /* set the first C-State to C1 */ 627 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 628 629 /* the C0 state only exists as a filler in our array, 630 * and all processors need to support C1 */ 631 pr->power.states[ACPI_STATE_C0].valid = 1; 632 pr->power.states[ACPI_STATE_C1].valid = 1; 633 634 return_VALUE(0); 635 } 636 637 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 638 { 639 acpi_status status = 0; 640 acpi_integer count; 641 int current_count; 642 int i; 643 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 644 union acpi_object *cst; 645 646 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst"); 647 648 if (nocst) 649 return_VALUE(-ENODEV); 650 651 current_count = 1; 652 653 /* Zero initialize C2 onwards and prepare for fresh CST lookup */ 654 for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++) 655 memset(&(pr->power.states[i]), 0, 656 sizeof(struct acpi_processor_cx)); 657 658 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 659 if (ACPI_FAILURE(status)) { 660 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 661 return_VALUE(-ENODEV); 662 } 663 664 cst = (union acpi_object *)buffer.pointer; 665 666 /* There must be at least 2 elements */ 667 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 668 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 669 "not enough elements in _CST\n")); 670 status = -EFAULT; 671 goto end; 672 } 673 674 count = cst->package.elements[0].integer.value; 675 676 /* Validate number of power states. */ 677 if (count < 1 || count != cst->package.count - 1) { 678 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 679 "count given by _CST is not valid\n")); 680 status = -EFAULT; 681 goto end; 682 } 683 684 /* Tell driver that at least _CST is supported. */ 685 pr->flags.has_cst = 1; 686 687 for (i = 1; i <= count; i++) { 688 union acpi_object *element; 689 union acpi_object *obj; 690 struct acpi_power_register *reg; 691 struct acpi_processor_cx cx; 692 693 memset(&cx, 0, sizeof(cx)); 694 695 element = (union acpi_object *)&(cst->package.elements[i]); 696 if (element->type != ACPI_TYPE_PACKAGE) 697 continue; 698 699 if (element->package.count != 4) 700 continue; 701 702 obj = (union acpi_object *)&(element->package.elements[0]); 703 704 if (obj->type != ACPI_TYPE_BUFFER) 705 continue; 706 707 reg = (struct acpi_power_register *)obj->buffer.pointer; 708 709 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 710 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 711 continue; 712 713 cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ? 714 0 : reg->address; 715 716 /* There should be an easy way to extract an integer... */ 717 obj = (union acpi_object *)&(element->package.elements[1]); 718 if (obj->type != ACPI_TYPE_INTEGER) 719 continue; 720 721 cx.type = obj->integer.value; 722 723 if ((cx.type != ACPI_STATE_C1) && 724 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) 725 continue; 726 727 if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3)) 728 continue; 729 730 obj = (union acpi_object *)&(element->package.elements[2]); 731 if (obj->type != ACPI_TYPE_INTEGER) 732 continue; 733 734 cx.latency = obj->integer.value; 735 736 obj = (union acpi_object *)&(element->package.elements[3]); 737 if (obj->type != ACPI_TYPE_INTEGER) 738 continue; 739 740 cx.power = obj->integer.value; 741 742 current_count++; 743 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 744 745 /* 746 * We support total ACPI_PROCESSOR_MAX_POWER - 1 747 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 748 */ 749 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 750 printk(KERN_WARNING 751 "Limiting number of power states to max (%d)\n", 752 ACPI_PROCESSOR_MAX_POWER); 753 printk(KERN_WARNING 754 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 755 break; 756 } 757 } 758 759 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 760 current_count)); 761 762 /* Validate number of power states discovered */ 763 if (current_count < 2) 764 status = -EFAULT; 765 766 end: 767 acpi_os_free(buffer.pointer); 768 769 return_VALUE(status); 770 } 771 772 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) 773 { 774 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2"); 775 776 if (!cx->address) 777 return_VOID; 778 779 /* 780 * C2 latency must be less than or equal to 100 781 * microseconds. 782 */ 783 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 784 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 785 "latency too large [%d]\n", cx->latency)); 786 return_VOID; 787 } 788 789 /* 790 * Otherwise we've met all of our C2 requirements. 791 * Normalize the C2 latency to expidite policy 792 */ 793 cx->valid = 1; 794 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 795 796 return_VOID; 797 } 798 799 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 800 struct acpi_processor_cx *cx) 801 { 802 static int bm_check_flag; 803 804 ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3"); 805 806 if (!cx->address) 807 return_VOID; 808 809 /* 810 * C3 latency must be less than or equal to 1000 811 * microseconds. 812 */ 813 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 814 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 815 "latency too large [%d]\n", cx->latency)); 816 return_VOID; 817 } 818 819 /* 820 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 821 * DMA transfers are used by any ISA device to avoid livelock. 822 * Note that we could disable Type-F DMA (as recommended by 823 * the erratum), but this is known to disrupt certain ISA 824 * devices thus we take the conservative approach. 825 */ 826 else if (errata.piix4.fdma) { 827 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 828 "C3 not supported on PIIX4 with Type-F DMA\n")); 829 return_VOID; 830 } 831 832 /* All the logic here assumes flags.bm_check is same across all CPUs */ 833 if (!bm_check_flag) { 834 /* Determine whether bm_check is needed based on CPU */ 835 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 836 bm_check_flag = pr->flags.bm_check; 837 } else { 838 pr->flags.bm_check = bm_check_flag; 839 } 840 841 if (pr->flags.bm_check) { 842 /* bus mastering control is necessary */ 843 if (!pr->flags.bm_control) { 844 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 845 "C3 support requires bus mastering control\n")); 846 return_VOID; 847 } 848 } else { 849 /* 850 * WBINVD should be set in fadt, for C3 state to be 851 * supported on when bm_check is not required. 852 */ 853 if (acpi_fadt.wb_invd != 1) { 854 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 855 "Cache invalidation should work properly" 856 " for C3 to be enabled on SMP systems\n")); 857 return_VOID; 858 } 859 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 860 0, ACPI_MTX_DO_NOT_LOCK); 861 } 862 863 /* 864 * Otherwise we've met all of our C3 requirements. 865 * Normalize the C3 latency to expidite policy. Enable 866 * checking of bus mastering status (bm_check) so we can 867 * use this in our C3 policy 868 */ 869 cx->valid = 1; 870 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency); 871 872 return_VOID; 873 } 874 875 static int acpi_processor_power_verify(struct acpi_processor *pr) 876 { 877 unsigned int i; 878 unsigned int working = 0; 879 880 #ifdef ARCH_APICTIMER_STOPS_ON_C3 881 struct cpuinfo_x86 *c = cpu_data + pr->id; 882 cpumask_t mask = cpumask_of_cpu(pr->id); 883 884 if (c->x86_vendor == X86_VENDOR_INTEL) { 885 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1); 886 } 887 #endif 888 889 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 890 struct acpi_processor_cx *cx = &pr->power.states[i]; 891 892 switch (cx->type) { 893 case ACPI_STATE_C1: 894 cx->valid = 1; 895 break; 896 897 case ACPI_STATE_C2: 898 acpi_processor_power_verify_c2(cx); 899 break; 900 901 case ACPI_STATE_C3: 902 acpi_processor_power_verify_c3(pr, cx); 903 #ifdef ARCH_APICTIMER_STOPS_ON_C3 904 if (cx->valid && c->x86_vendor == X86_VENDOR_INTEL) { 905 on_each_cpu(switch_APIC_timer_to_ipi, 906 &mask, 1, 1); 907 } 908 #endif 909 break; 910 } 911 912 if (cx->valid) 913 working++; 914 } 915 916 return (working); 917 } 918 919 static int acpi_processor_get_power_info(struct acpi_processor *pr) 920 { 921 unsigned int i; 922 int result; 923 924 ACPI_FUNCTION_TRACE("acpi_processor_get_power_info"); 925 926 /* NOTE: the idle thread may not be running while calling 927 * this function */ 928 929 /* Adding C1 state */ 930 acpi_processor_get_power_info_default_c1(pr); 931 result = acpi_processor_get_power_info_cst(pr); 932 if (result == -ENODEV) 933 acpi_processor_get_power_info_fadt(pr); 934 935 pr->power.count = acpi_processor_power_verify(pr); 936 937 /* 938 * Set Default Policy 939 * ------------------ 940 * Now that we know which states are supported, set the default 941 * policy. Note that this policy can be changed dynamically 942 * (e.g. encourage deeper sleeps to conserve battery life when 943 * not on AC). 944 */ 945 result = acpi_processor_set_power_policy(pr); 946 if (result) 947 return_VALUE(result); 948 949 /* 950 * if one state of type C2 or C3 is available, mark this 951 * CPU as being "idle manageable" 952 */ 953 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 954 if (pr->power.states[i].valid) { 955 pr->power.count = i; 956 if (pr->power.states[i].type >= ACPI_STATE_C2) 957 pr->flags.power = 1; 958 } 959 } 960 961 return_VALUE(0); 962 } 963 964 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 965 { 966 int result = 0; 967 968 ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed"); 969 970 if (!pr) 971 return_VALUE(-EINVAL); 972 973 if (nocst) { 974 return_VALUE(-ENODEV); 975 } 976 977 if (!pr->flags.power_setup_done) 978 return_VALUE(-ENODEV); 979 980 /* Fall back to the default idle loop */ 981 pm_idle = pm_idle_save; 982 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */ 983 984 pr->flags.power = 0; 985 result = acpi_processor_get_power_info(pr); 986 if ((pr->flags.power == 1) && (pr->flags.power_setup_done)) 987 pm_idle = acpi_processor_idle; 988 989 return_VALUE(result); 990 } 991 992 /* proc interface */ 993 994 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset) 995 { 996 struct acpi_processor *pr = (struct acpi_processor *)seq->private; 997 unsigned int i; 998 999 ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show"); 1000 1001 if (!pr) 1002 goto end; 1003 1004 seq_printf(seq, "active state: C%zd\n" 1005 "max_cstate: C%d\n" 1006 "bus master activity: %08x\n", 1007 pr->power.state ? pr->power.state - pr->power.states : 0, 1008 max_cstate, (unsigned)pr->power.bm_activity); 1009 1010 seq_puts(seq, "states:\n"); 1011 1012 for (i = 1; i <= pr->power.count; i++) { 1013 seq_printf(seq, " %cC%d: ", 1014 (&pr->power.states[i] == 1015 pr->power.state ? '*' : ' '), i); 1016 1017 if (!pr->power.states[i].valid) { 1018 seq_puts(seq, "<not supported>\n"); 1019 continue; 1020 } 1021 1022 switch (pr->power.states[i].type) { 1023 case ACPI_STATE_C1: 1024 seq_printf(seq, "type[C1] "); 1025 break; 1026 case ACPI_STATE_C2: 1027 seq_printf(seq, "type[C2] "); 1028 break; 1029 case ACPI_STATE_C3: 1030 seq_printf(seq, "type[C3] "); 1031 break; 1032 default: 1033 seq_printf(seq, "type[--] "); 1034 break; 1035 } 1036 1037 if (pr->power.states[i].promotion.state) 1038 seq_printf(seq, "promotion[C%zd] ", 1039 (pr->power.states[i].promotion.state - 1040 pr->power.states)); 1041 else 1042 seq_puts(seq, "promotion[--] "); 1043 1044 if (pr->power.states[i].demotion.state) 1045 seq_printf(seq, "demotion[C%zd] ", 1046 (pr->power.states[i].demotion.state - 1047 pr->power.states)); 1048 else 1049 seq_puts(seq, "demotion[--] "); 1050 1051 seq_printf(seq, "latency[%03d] usage[%08d]\n", 1052 pr->power.states[i].latency, 1053 pr->power.states[i].usage); 1054 } 1055 1056 end: 1057 return_VALUE(0); 1058 } 1059 1060 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file) 1061 { 1062 return single_open(file, acpi_processor_power_seq_show, 1063 PDE(inode)->data); 1064 } 1065 1066 static struct file_operations acpi_processor_power_fops = { 1067 .open = acpi_processor_power_open_fs, 1068 .read = seq_read, 1069 .llseek = seq_lseek, 1070 .release = single_release, 1071 }; 1072 1073 int acpi_processor_power_init(struct acpi_processor *pr, 1074 struct acpi_device *device) 1075 { 1076 acpi_status status = 0; 1077 static int first_run = 0; 1078 struct proc_dir_entry *entry = NULL; 1079 unsigned int i; 1080 1081 ACPI_FUNCTION_TRACE("acpi_processor_power_init"); 1082 1083 if (!first_run) { 1084 dmi_check_system(processor_power_dmi_table); 1085 if (max_cstate < ACPI_C_STATES_MAX) 1086 printk(KERN_NOTICE 1087 "ACPI: processor limited to max C-state %d\n", 1088 max_cstate); 1089 first_run++; 1090 } 1091 1092 if (!pr) 1093 return_VALUE(-EINVAL); 1094 1095 if (acpi_fadt.cst_cnt && !nocst) { 1096 status = 1097 acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8); 1098 if (ACPI_FAILURE(status)) { 1099 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 1100 "Notifying BIOS of _CST ability failed\n")); 1101 } 1102 } 1103 1104 acpi_processor_get_power_info(pr); 1105 1106 /* 1107 * Install the idle handler if processor power management is supported. 1108 * Note that we use previously set idle handler will be used on 1109 * platforms that only support C1. 1110 */ 1111 if ((pr->flags.power) && (!boot_option_idle_override)) { 1112 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id); 1113 for (i = 1; i <= pr->power.count; i++) 1114 if (pr->power.states[i].valid) 1115 printk(" C%d[C%d]", i, 1116 pr->power.states[i].type); 1117 printk(")\n"); 1118 1119 if (pr->id == 0) { 1120 pm_idle_save = pm_idle; 1121 pm_idle = acpi_processor_idle; 1122 } 1123 } 1124 1125 /* 'power' [R] */ 1126 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1127 S_IRUGO, acpi_device_dir(device)); 1128 if (!entry) 1129 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 1130 "Unable to create '%s' fs entry\n", 1131 ACPI_PROCESSOR_FILE_POWER)); 1132 else { 1133 entry->proc_fops = &acpi_processor_power_fops; 1134 entry->data = acpi_driver_data(device); 1135 entry->owner = THIS_MODULE; 1136 } 1137 1138 pr->flags.power_setup_done = 1; 1139 1140 return_VALUE(0); 1141 } 1142 1143 int acpi_processor_power_exit(struct acpi_processor *pr, 1144 struct acpi_device *device) 1145 { 1146 ACPI_FUNCTION_TRACE("acpi_processor_power_exit"); 1147 1148 pr->flags.power_setup_done = 0; 1149 1150 if (acpi_device_dir(device)) 1151 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER, 1152 acpi_device_dir(device)); 1153 1154 /* Unregister the idle handler when processor #0 is removed. */ 1155 if (pr->id == 0) { 1156 pm_idle = pm_idle_save; 1157 1158 /* 1159 * We are about to unload the current idle thread pm callback 1160 * (pm_idle), Wait for all processors to update cached/local 1161 * copies of pm_idle before proceeding. 1162 */ 1163 cpu_idle_wait(); 1164 } 1165 1166 return_VALUE(0); 1167 } 1168