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 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 25 */ 26 #define pr_fmt(fmt) "ACPI: " fmt 27 28 #include <linux/module.h> 29 #include <linux/acpi.h> 30 #include <linux/dmi.h> 31 #include <linux/sched.h> /* need_resched() */ 32 #include <linux/tick.h> 33 #include <linux/cpuidle.h> 34 #include <acpi/processor.h> 35 36 /* 37 * Include the apic definitions for x86 to have the APIC timer related defines 38 * available also for UP (on SMP it gets magically included via linux/smp.h). 39 * asm/acpi.h is not an option, as it would require more include magic. Also 40 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 41 */ 42 #ifdef CONFIG_X86 43 #include <asm/apic.h> 44 #endif 45 46 #define ACPI_PROCESSOR_CLASS "processor" 47 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 48 ACPI_MODULE_NAME("processor_idle"); 49 50 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 51 module_param(max_cstate, uint, 0000); 52 static unsigned int nocst __read_mostly; 53 module_param(nocst, uint, 0000); 54 static int bm_check_disable __read_mostly; 55 module_param(bm_check_disable, uint, 0000); 56 57 static unsigned int latency_factor __read_mostly = 2; 58 module_param(latency_factor, uint, 0644); 59 60 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 61 62 static 63 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 64 65 static int disabled_by_idle_boot_param(void) 66 { 67 return boot_option_idle_override == IDLE_POLL || 68 boot_option_idle_override == IDLE_HALT; 69 } 70 71 /* 72 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 73 * For now disable this. Probably a bug somewhere else. 74 * 75 * To skip this limit, boot/load with a large max_cstate limit. 76 */ 77 static int set_max_cstate(const struct dmi_system_id *id) 78 { 79 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 80 return 0; 81 82 pr_notice("%s detected - limiting to C%ld max_cstate." 83 " Override with \"processor.max_cstate=%d\"\n", id->ident, 84 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 85 86 max_cstate = (long)id->driver_data; 87 88 return 0; 89 } 90 91 static const struct dmi_system_id processor_power_dmi_table[] = { 92 { set_max_cstate, "Clevo 5600D", { 93 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 94 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 95 (void *)2}, 96 { set_max_cstate, "Pavilion zv5000", { 97 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 98 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 99 (void *)1}, 100 { set_max_cstate, "Asus L8400B", { 101 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 102 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 103 (void *)1}, 104 {}, 105 }; 106 107 108 /* 109 * Callers should disable interrupts before the call and enable 110 * interrupts after return. 111 */ 112 static void acpi_safe_halt(void) 113 { 114 if (!tif_need_resched()) { 115 safe_halt(); 116 local_irq_disable(); 117 } 118 } 119 120 #ifdef ARCH_APICTIMER_STOPS_ON_C3 121 122 /* 123 * Some BIOS implementations switch to C3 in the published C2 state. 124 * This seems to be a common problem on AMD boxen, but other vendors 125 * are affected too. We pick the most conservative approach: we assume 126 * that the local APIC stops in both C2 and C3. 127 */ 128 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 129 struct acpi_processor_cx *cx) 130 { 131 struct acpi_processor_power *pwr = &pr->power; 132 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 133 134 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 135 return; 136 137 if (amd_e400_c1e_detected) 138 type = ACPI_STATE_C1; 139 140 /* 141 * Check, if one of the previous states already marked the lapic 142 * unstable 143 */ 144 if (pwr->timer_broadcast_on_state < state) 145 return; 146 147 if (cx->type >= type) 148 pr->power.timer_broadcast_on_state = state; 149 } 150 151 static void __lapic_timer_propagate_broadcast(void *arg) 152 { 153 struct acpi_processor *pr = (struct acpi_processor *) arg; 154 155 if (pr->power.timer_broadcast_on_state < INT_MAX) 156 tick_broadcast_enable(); 157 else 158 tick_broadcast_disable(); 159 } 160 161 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 162 { 163 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 164 (void *)pr, 1); 165 } 166 167 /* Power(C) State timer broadcast control */ 168 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 169 struct acpi_processor_cx *cx, 170 int broadcast) 171 { 172 int state = cx - pr->power.states; 173 174 if (state >= pr->power.timer_broadcast_on_state) { 175 if (broadcast) 176 tick_broadcast_enter(); 177 else 178 tick_broadcast_exit(); 179 } 180 } 181 182 #else 183 184 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 185 struct acpi_processor_cx *cstate) { } 186 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 187 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 188 struct acpi_processor_cx *cx, 189 int broadcast) 190 { 191 } 192 193 #endif 194 195 #if defined(CONFIG_X86) 196 static void tsc_check_state(int state) 197 { 198 switch (boot_cpu_data.x86_vendor) { 199 case X86_VENDOR_AMD: 200 case X86_VENDOR_INTEL: 201 /* 202 * AMD Fam10h TSC will tick in all 203 * C/P/S0/S1 states when this bit is set. 204 */ 205 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 206 return; 207 208 /*FALL THROUGH*/ 209 default: 210 /* TSC could halt in idle, so notify users */ 211 if (state > ACPI_STATE_C1) 212 mark_tsc_unstable("TSC halts in idle"); 213 } 214 } 215 #else 216 static void tsc_check_state(int state) { return; } 217 #endif 218 219 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 220 { 221 222 if (!pr->pblk) 223 return -ENODEV; 224 225 /* if info is obtained from pblk/fadt, type equals state */ 226 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 227 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 228 229 #ifndef CONFIG_HOTPLUG_CPU 230 /* 231 * Check for P_LVL2_UP flag before entering C2 and above on 232 * an SMP system. 233 */ 234 if ((num_online_cpus() > 1) && 235 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 236 return -ENODEV; 237 #endif 238 239 /* determine C2 and C3 address from pblk */ 240 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 241 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 242 243 /* determine latencies from FADT */ 244 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 245 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 246 247 /* 248 * FADT specified C2 latency must be less than or equal to 249 * 100 microseconds. 250 */ 251 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 252 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 253 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 254 /* invalidate C2 */ 255 pr->power.states[ACPI_STATE_C2].address = 0; 256 } 257 258 /* 259 * FADT supplied C3 latency must be less than or equal to 260 * 1000 microseconds. 261 */ 262 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 263 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 264 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 265 /* invalidate C3 */ 266 pr->power.states[ACPI_STATE_C3].address = 0; 267 } 268 269 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 270 "lvl2[0x%08x] lvl3[0x%08x]\n", 271 pr->power.states[ACPI_STATE_C2].address, 272 pr->power.states[ACPI_STATE_C3].address)); 273 274 return 0; 275 } 276 277 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 278 { 279 if (!pr->power.states[ACPI_STATE_C1].valid) { 280 /* set the first C-State to C1 */ 281 /* all processors need to support C1 */ 282 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 283 pr->power.states[ACPI_STATE_C1].valid = 1; 284 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 285 } 286 /* the C0 state only exists as a filler in our array */ 287 pr->power.states[ACPI_STATE_C0].valid = 1; 288 return 0; 289 } 290 291 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 292 { 293 acpi_status status; 294 u64 count; 295 int current_count; 296 int i, ret = 0; 297 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 298 union acpi_object *cst; 299 300 301 if (nocst) 302 return -ENODEV; 303 304 current_count = 0; 305 306 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 307 if (ACPI_FAILURE(status)) { 308 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 309 return -ENODEV; 310 } 311 312 cst = buffer.pointer; 313 314 /* There must be at least 2 elements */ 315 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 316 pr_err("not enough elements in _CST\n"); 317 ret = -EFAULT; 318 goto end; 319 } 320 321 count = cst->package.elements[0].integer.value; 322 323 /* Validate number of power states. */ 324 if (count < 1 || count != cst->package.count - 1) { 325 pr_err("count given by _CST is not valid\n"); 326 ret = -EFAULT; 327 goto end; 328 } 329 330 /* Tell driver that at least _CST is supported. */ 331 pr->flags.has_cst = 1; 332 333 for (i = 1; i <= count; i++) { 334 union acpi_object *element; 335 union acpi_object *obj; 336 struct acpi_power_register *reg; 337 struct acpi_processor_cx cx; 338 339 memset(&cx, 0, sizeof(cx)); 340 341 element = &(cst->package.elements[i]); 342 if (element->type != ACPI_TYPE_PACKAGE) 343 continue; 344 345 if (element->package.count != 4) 346 continue; 347 348 obj = &(element->package.elements[0]); 349 350 if (obj->type != ACPI_TYPE_BUFFER) 351 continue; 352 353 reg = (struct acpi_power_register *)obj->buffer.pointer; 354 355 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 356 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 357 continue; 358 359 /* There should be an easy way to extract an integer... */ 360 obj = &(element->package.elements[1]); 361 if (obj->type != ACPI_TYPE_INTEGER) 362 continue; 363 364 cx.type = obj->integer.value; 365 /* 366 * Some buggy BIOSes won't list C1 in _CST - 367 * Let acpi_processor_get_power_info_default() handle them later 368 */ 369 if (i == 1 && cx.type != ACPI_STATE_C1) 370 current_count++; 371 372 cx.address = reg->address; 373 cx.index = current_count + 1; 374 375 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 376 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 377 if (acpi_processor_ffh_cstate_probe 378 (pr->id, &cx, reg) == 0) { 379 cx.entry_method = ACPI_CSTATE_FFH; 380 } else if (cx.type == ACPI_STATE_C1) { 381 /* 382 * C1 is a special case where FIXED_HARDWARE 383 * can be handled in non-MWAIT way as well. 384 * In that case, save this _CST entry info. 385 * Otherwise, ignore this info and continue. 386 */ 387 cx.entry_method = ACPI_CSTATE_HALT; 388 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 389 } else { 390 continue; 391 } 392 if (cx.type == ACPI_STATE_C1 && 393 (boot_option_idle_override == IDLE_NOMWAIT)) { 394 /* 395 * In most cases the C1 space_id obtained from 396 * _CST object is FIXED_HARDWARE access mode. 397 * But when the option of idle=halt is added, 398 * the entry_method type should be changed from 399 * CSTATE_FFH to CSTATE_HALT. 400 * When the option of idle=nomwait is added, 401 * the C1 entry_method type should be 402 * CSTATE_HALT. 403 */ 404 cx.entry_method = ACPI_CSTATE_HALT; 405 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 406 } 407 } else { 408 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 409 cx.address); 410 } 411 412 if (cx.type == ACPI_STATE_C1) { 413 cx.valid = 1; 414 } 415 416 obj = &(element->package.elements[2]); 417 if (obj->type != ACPI_TYPE_INTEGER) 418 continue; 419 420 cx.latency = obj->integer.value; 421 422 obj = &(element->package.elements[3]); 423 if (obj->type != ACPI_TYPE_INTEGER) 424 continue; 425 426 current_count++; 427 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 428 429 /* 430 * We support total ACPI_PROCESSOR_MAX_POWER - 1 431 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 432 */ 433 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 434 pr_warn("Limiting number of power states to max (%d)\n", 435 ACPI_PROCESSOR_MAX_POWER); 436 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 437 break; 438 } 439 } 440 441 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 442 current_count)); 443 444 /* Validate number of power states discovered */ 445 if (current_count < 2) 446 ret = -EFAULT; 447 448 end: 449 kfree(buffer.pointer); 450 451 return ret; 452 } 453 454 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 455 struct acpi_processor_cx *cx) 456 { 457 static int bm_check_flag = -1; 458 static int bm_control_flag = -1; 459 460 461 if (!cx->address) 462 return; 463 464 /* 465 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 466 * DMA transfers are used by any ISA device to avoid livelock. 467 * Note that we could disable Type-F DMA (as recommended by 468 * the erratum), but this is known to disrupt certain ISA 469 * devices thus we take the conservative approach. 470 */ 471 else if (errata.piix4.fdma) { 472 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 473 "C3 not supported on PIIX4 with Type-F DMA\n")); 474 return; 475 } 476 477 /* All the logic here assumes flags.bm_check is same across all CPUs */ 478 if (bm_check_flag == -1) { 479 /* Determine whether bm_check is needed based on CPU */ 480 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 481 bm_check_flag = pr->flags.bm_check; 482 bm_control_flag = pr->flags.bm_control; 483 } else { 484 pr->flags.bm_check = bm_check_flag; 485 pr->flags.bm_control = bm_control_flag; 486 } 487 488 if (pr->flags.bm_check) { 489 if (!pr->flags.bm_control) { 490 if (pr->flags.has_cst != 1) { 491 /* bus mastering control is necessary */ 492 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 493 "C3 support requires BM control\n")); 494 return; 495 } else { 496 /* Here we enter C3 without bus mastering */ 497 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 498 "C3 support without BM control\n")); 499 } 500 } 501 } else { 502 /* 503 * WBINVD should be set in fadt, for C3 state to be 504 * supported on when bm_check is not required. 505 */ 506 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 507 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 508 "Cache invalidation should work properly" 509 " for C3 to be enabled on SMP systems\n")); 510 return; 511 } 512 } 513 514 /* 515 * Otherwise we've met all of our C3 requirements. 516 * Normalize the C3 latency to expidite policy. Enable 517 * checking of bus mastering status (bm_check) so we can 518 * use this in our C3 policy 519 */ 520 cx->valid = 1; 521 522 /* 523 * On older chipsets, BM_RLD needs to be set 524 * in order for Bus Master activity to wake the 525 * system from C3. Newer chipsets handle DMA 526 * during C3 automatically and BM_RLD is a NOP. 527 * In either case, the proper way to 528 * handle BM_RLD is to set it and leave it set. 529 */ 530 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 531 532 return; 533 } 534 535 static int acpi_processor_power_verify(struct acpi_processor *pr) 536 { 537 unsigned int i; 538 unsigned int working = 0; 539 540 pr->power.timer_broadcast_on_state = INT_MAX; 541 542 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 543 struct acpi_processor_cx *cx = &pr->power.states[i]; 544 545 switch (cx->type) { 546 case ACPI_STATE_C1: 547 cx->valid = 1; 548 break; 549 550 case ACPI_STATE_C2: 551 if (!cx->address) 552 break; 553 cx->valid = 1; 554 break; 555 556 case ACPI_STATE_C3: 557 acpi_processor_power_verify_c3(pr, cx); 558 break; 559 } 560 if (!cx->valid) 561 continue; 562 563 lapic_timer_check_state(i, pr, cx); 564 tsc_check_state(cx->type); 565 working++; 566 } 567 568 lapic_timer_propagate_broadcast(pr); 569 570 return (working); 571 } 572 573 static int acpi_processor_get_power_info(struct acpi_processor *pr) 574 { 575 unsigned int i; 576 int result; 577 578 579 /* NOTE: the idle thread may not be running while calling 580 * this function */ 581 582 /* Zero initialize all the C-states info. */ 583 memset(pr->power.states, 0, sizeof(pr->power.states)); 584 585 result = acpi_processor_get_power_info_cst(pr); 586 if (result == -ENODEV) 587 result = acpi_processor_get_power_info_fadt(pr); 588 589 if (result) 590 return result; 591 592 acpi_processor_get_power_info_default(pr); 593 594 pr->power.count = acpi_processor_power_verify(pr); 595 596 /* 597 * if one state of type C2 or C3 is available, mark this 598 * CPU as being "idle manageable" 599 */ 600 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 601 if (pr->power.states[i].valid) { 602 pr->power.count = i; 603 if (pr->power.states[i].type >= ACPI_STATE_C2) 604 pr->flags.power = 1; 605 } 606 } 607 608 return 0; 609 } 610 611 /** 612 * acpi_idle_bm_check - checks if bus master activity was detected 613 */ 614 static int acpi_idle_bm_check(void) 615 { 616 u32 bm_status = 0; 617 618 if (bm_check_disable) 619 return 0; 620 621 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 622 if (bm_status) 623 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 624 /* 625 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 626 * the true state of bus mastering activity; forcing us to 627 * manually check the BMIDEA bit of each IDE channel. 628 */ 629 else if (errata.piix4.bmisx) { 630 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 631 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 632 bm_status = 1; 633 } 634 return bm_status; 635 } 636 637 /** 638 * acpi_idle_do_entry - enter idle state using the appropriate method 639 * @cx: cstate data 640 * 641 * Caller disables interrupt before call and enables interrupt after return. 642 */ 643 static void acpi_idle_do_entry(struct acpi_processor_cx *cx) 644 { 645 if (cx->entry_method == ACPI_CSTATE_FFH) { 646 /* Call into architectural FFH based C-state */ 647 acpi_processor_ffh_cstate_enter(cx); 648 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 649 acpi_safe_halt(); 650 } else { 651 /* IO port based C-state */ 652 inb(cx->address); 653 /* Dummy wait op - must do something useless after P_LVL2 read 654 because chipsets cannot guarantee that STPCLK# signal 655 gets asserted in time to freeze execution properly. */ 656 inl(acpi_gbl_FADT.xpm_timer_block.address); 657 } 658 } 659 660 /** 661 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 662 * @dev: the target CPU 663 * @index: the index of suggested state 664 */ 665 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 666 { 667 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 668 669 ACPI_FLUSH_CPU_CACHE(); 670 671 while (1) { 672 673 if (cx->entry_method == ACPI_CSTATE_HALT) 674 safe_halt(); 675 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 676 inb(cx->address); 677 /* See comment in acpi_idle_do_entry() */ 678 inl(acpi_gbl_FADT.xpm_timer_block.address); 679 } else 680 return -ENODEV; 681 } 682 683 /* Never reached */ 684 return 0; 685 } 686 687 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 688 { 689 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 690 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 691 } 692 693 static int c3_cpu_count; 694 static DEFINE_RAW_SPINLOCK(c3_lock); 695 696 /** 697 * acpi_idle_enter_bm - enters C3 with proper BM handling 698 * @pr: Target processor 699 * @cx: Target state context 700 * @timer_bc: Whether or not to change timer mode to broadcast 701 */ 702 static void acpi_idle_enter_bm(struct acpi_processor *pr, 703 struct acpi_processor_cx *cx, bool timer_bc) 704 { 705 acpi_unlazy_tlb(smp_processor_id()); 706 707 /* 708 * Must be done before busmaster disable as we might need to 709 * access HPET ! 710 */ 711 if (timer_bc) 712 lapic_timer_state_broadcast(pr, cx, 1); 713 714 /* 715 * disable bus master 716 * bm_check implies we need ARB_DIS 717 * bm_control implies whether we can do ARB_DIS 718 * 719 * That leaves a case where bm_check is set and bm_control is 720 * not set. In that case we cannot do much, we enter C3 721 * without doing anything. 722 */ 723 if (pr->flags.bm_control) { 724 raw_spin_lock(&c3_lock); 725 c3_cpu_count++; 726 /* Disable bus master arbitration when all CPUs are in C3 */ 727 if (c3_cpu_count == num_online_cpus()) 728 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 729 raw_spin_unlock(&c3_lock); 730 } 731 732 acpi_idle_do_entry(cx); 733 734 /* Re-enable bus master arbitration */ 735 if (pr->flags.bm_control) { 736 raw_spin_lock(&c3_lock); 737 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 738 c3_cpu_count--; 739 raw_spin_unlock(&c3_lock); 740 } 741 742 if (timer_bc) 743 lapic_timer_state_broadcast(pr, cx, 0); 744 } 745 746 static int acpi_idle_enter(struct cpuidle_device *dev, 747 struct cpuidle_driver *drv, int index) 748 { 749 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 750 struct acpi_processor *pr; 751 752 pr = __this_cpu_read(processors); 753 if (unlikely(!pr)) 754 return -EINVAL; 755 756 if (cx->type != ACPI_STATE_C1) { 757 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 758 index = CPUIDLE_DRIVER_STATE_START; 759 cx = per_cpu(acpi_cstate[index], dev->cpu); 760 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 761 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 762 acpi_idle_enter_bm(pr, cx, true); 763 return index; 764 } else if (drv->safe_state_index >= 0) { 765 index = drv->safe_state_index; 766 cx = per_cpu(acpi_cstate[index], dev->cpu); 767 } else { 768 acpi_safe_halt(); 769 return -EBUSY; 770 } 771 } 772 } 773 774 lapic_timer_state_broadcast(pr, cx, 1); 775 776 if (cx->type == ACPI_STATE_C3) 777 ACPI_FLUSH_CPU_CACHE(); 778 779 acpi_idle_do_entry(cx); 780 781 lapic_timer_state_broadcast(pr, cx, 0); 782 783 return index; 784 } 785 786 static void acpi_idle_enter_freeze(struct cpuidle_device *dev, 787 struct cpuidle_driver *drv, int index) 788 { 789 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 790 791 if (cx->type == ACPI_STATE_C3) { 792 struct acpi_processor *pr = __this_cpu_read(processors); 793 794 if (unlikely(!pr)) 795 return; 796 797 if (pr->flags.bm_check) { 798 acpi_idle_enter_bm(pr, cx, false); 799 return; 800 } else { 801 ACPI_FLUSH_CPU_CACHE(); 802 } 803 } 804 acpi_idle_do_entry(cx); 805 } 806 807 struct cpuidle_driver acpi_idle_driver = { 808 .name = "acpi_idle", 809 .owner = THIS_MODULE, 810 }; 811 812 /** 813 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE 814 * device i.e. per-cpu data 815 * 816 * @pr: the ACPI processor 817 * @dev : the cpuidle device 818 */ 819 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 820 struct cpuidle_device *dev) 821 { 822 int i, count = CPUIDLE_DRIVER_STATE_START; 823 struct acpi_processor_cx *cx; 824 825 if (!pr->flags.power_setup_done) 826 return -EINVAL; 827 828 if (pr->flags.power == 0) { 829 return -EINVAL; 830 } 831 832 if (!dev) 833 return -EINVAL; 834 835 dev->cpu = pr->id; 836 837 if (max_cstate == 0) 838 max_cstate = 1; 839 840 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 841 cx = &pr->power.states[i]; 842 843 if (!cx->valid) 844 continue; 845 846 per_cpu(acpi_cstate[count], dev->cpu) = cx; 847 848 count++; 849 if (count == CPUIDLE_STATE_MAX) 850 break; 851 } 852 853 if (!count) 854 return -EINVAL; 855 856 return 0; 857 } 858 859 /** 860 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle 861 * global state data i.e. idle routines 862 * 863 * @pr: the ACPI processor 864 */ 865 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 866 { 867 int i, count = CPUIDLE_DRIVER_STATE_START; 868 struct acpi_processor_cx *cx; 869 struct cpuidle_state *state; 870 struct cpuidle_driver *drv = &acpi_idle_driver; 871 872 if (!pr->flags.power_setup_done) 873 return -EINVAL; 874 875 if (pr->flags.power == 0) 876 return -EINVAL; 877 878 drv->safe_state_index = -1; 879 for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 880 drv->states[i].name[0] = '\0'; 881 drv->states[i].desc[0] = '\0'; 882 } 883 884 if (max_cstate == 0) 885 max_cstate = 1; 886 887 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 888 cx = &pr->power.states[i]; 889 890 if (!cx->valid) 891 continue; 892 893 state = &drv->states[count]; 894 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 895 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 896 state->exit_latency = cx->latency; 897 state->target_residency = cx->latency * latency_factor; 898 state->enter = acpi_idle_enter; 899 900 state->flags = 0; 901 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 902 state->enter_dead = acpi_idle_play_dead; 903 drv->safe_state_index = count; 904 } 905 /* 906 * Halt-induced C1 is not good for ->enter_freeze, because it 907 * re-enables interrupts on exit. Moreover, C1 is generally not 908 * particularly interesting from the suspend-to-idle angle, so 909 * avoid C1 and the situations in which we may need to fall back 910 * to it altogether. 911 */ 912 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 913 state->enter_freeze = acpi_idle_enter_freeze; 914 915 count++; 916 if (count == CPUIDLE_STATE_MAX) 917 break; 918 } 919 920 drv->state_count = count; 921 922 if (!count) 923 return -EINVAL; 924 925 return 0; 926 } 927 928 int acpi_processor_hotplug(struct acpi_processor *pr) 929 { 930 int ret = 0; 931 struct cpuidle_device *dev; 932 933 if (disabled_by_idle_boot_param()) 934 return 0; 935 936 if (nocst) 937 return -ENODEV; 938 939 if (!pr->flags.power_setup_done) 940 return -ENODEV; 941 942 dev = per_cpu(acpi_cpuidle_device, pr->id); 943 cpuidle_pause_and_lock(); 944 cpuidle_disable_device(dev); 945 acpi_processor_get_power_info(pr); 946 if (pr->flags.power) { 947 acpi_processor_setup_cpuidle_cx(pr, dev); 948 ret = cpuidle_enable_device(dev); 949 } 950 cpuidle_resume_and_unlock(); 951 952 return ret; 953 } 954 955 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 956 { 957 int cpu; 958 struct acpi_processor *_pr; 959 struct cpuidle_device *dev; 960 961 if (disabled_by_idle_boot_param()) 962 return 0; 963 964 if (nocst) 965 return -ENODEV; 966 967 if (!pr->flags.power_setup_done) 968 return -ENODEV; 969 970 /* 971 * FIXME: Design the ACPI notification to make it once per 972 * system instead of once per-cpu. This condition is a hack 973 * to make the code that updates C-States be called once. 974 */ 975 976 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 977 978 /* Protect against cpu-hotplug */ 979 get_online_cpus(); 980 cpuidle_pause_and_lock(); 981 982 /* Disable all cpuidle devices */ 983 for_each_online_cpu(cpu) { 984 _pr = per_cpu(processors, cpu); 985 if (!_pr || !_pr->flags.power_setup_done) 986 continue; 987 dev = per_cpu(acpi_cpuidle_device, cpu); 988 cpuidle_disable_device(dev); 989 } 990 991 /* Populate Updated C-state information */ 992 acpi_processor_get_power_info(pr); 993 acpi_processor_setup_cpuidle_states(pr); 994 995 /* Enable all cpuidle devices */ 996 for_each_online_cpu(cpu) { 997 _pr = per_cpu(processors, cpu); 998 if (!_pr || !_pr->flags.power_setup_done) 999 continue; 1000 acpi_processor_get_power_info(_pr); 1001 if (_pr->flags.power) { 1002 dev = per_cpu(acpi_cpuidle_device, cpu); 1003 acpi_processor_setup_cpuidle_cx(_pr, dev); 1004 cpuidle_enable_device(dev); 1005 } 1006 } 1007 cpuidle_resume_and_unlock(); 1008 put_online_cpus(); 1009 } 1010 1011 return 0; 1012 } 1013 1014 static int acpi_processor_registered; 1015 1016 int acpi_processor_power_init(struct acpi_processor *pr) 1017 { 1018 acpi_status status; 1019 int retval; 1020 struct cpuidle_device *dev; 1021 static int first_run; 1022 1023 if (disabled_by_idle_boot_param()) 1024 return 0; 1025 1026 if (!first_run) { 1027 dmi_check_system(processor_power_dmi_table); 1028 max_cstate = acpi_processor_cstate_check(max_cstate); 1029 if (max_cstate < ACPI_C_STATES_MAX) 1030 printk(KERN_NOTICE 1031 "ACPI: processor limited to max C-state %d\n", 1032 max_cstate); 1033 first_run++; 1034 } 1035 1036 if (acpi_gbl_FADT.cst_control && !nocst) { 1037 status = 1038 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8); 1039 if (ACPI_FAILURE(status)) { 1040 ACPI_EXCEPTION((AE_INFO, status, 1041 "Notifying BIOS of _CST ability failed")); 1042 } 1043 } 1044 1045 acpi_processor_get_power_info(pr); 1046 pr->flags.power_setup_done = 1; 1047 1048 /* 1049 * Install the idle handler if processor power management is supported. 1050 * Note that we use previously set idle handler will be used on 1051 * platforms that only support C1. 1052 */ 1053 if (pr->flags.power) { 1054 /* Register acpi_idle_driver if not already registered */ 1055 if (!acpi_processor_registered) { 1056 acpi_processor_setup_cpuidle_states(pr); 1057 retval = cpuidle_register_driver(&acpi_idle_driver); 1058 if (retval) 1059 return retval; 1060 pr_debug("%s registered with cpuidle\n", 1061 acpi_idle_driver.name); 1062 } 1063 1064 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1065 if (!dev) 1066 return -ENOMEM; 1067 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1068 1069 acpi_processor_setup_cpuidle_cx(pr, dev); 1070 1071 /* Register per-cpu cpuidle_device. Cpuidle driver 1072 * must already be registered before registering device 1073 */ 1074 retval = cpuidle_register_device(dev); 1075 if (retval) { 1076 if (acpi_processor_registered == 0) 1077 cpuidle_unregister_driver(&acpi_idle_driver); 1078 return retval; 1079 } 1080 acpi_processor_registered++; 1081 } 1082 return 0; 1083 } 1084 1085 int acpi_processor_power_exit(struct acpi_processor *pr) 1086 { 1087 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1088 1089 if (disabled_by_idle_boot_param()) 1090 return 0; 1091 1092 if (pr->flags.power) { 1093 cpuidle_unregister_device(dev); 1094 acpi_processor_registered--; 1095 if (acpi_processor_registered == 0) 1096 cpuidle_unregister_driver(&acpi_idle_driver); 1097 } 1098 1099 pr->flags.power_setup_done = 0; 1100 return 0; 1101 } 1102