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 struct cpuidle_driver acpi_idle_driver = { 63 .name = "acpi_idle", 64 .owner = THIS_MODULE, 65 }; 66 67 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 68 static 69 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 70 71 static int disabled_by_idle_boot_param(void) 72 { 73 return boot_option_idle_override == IDLE_POLL || 74 boot_option_idle_override == IDLE_HALT; 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(const struct dmi_system_id *id) 84 { 85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 86 return 0; 87 88 pr_notice("%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 static const struct dmi_system_id processor_power_dmi_table[] = { 98 { set_max_cstate, "Clevo 5600D", { 99 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 100 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 101 (void *)2}, 102 { set_max_cstate, "Pavilion zv5000", { 103 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 104 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 105 (void *)1}, 106 { set_max_cstate, "Asus L8400B", { 107 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 108 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 109 (void *)1}, 110 {}, 111 }; 112 113 114 /* 115 * Callers should disable interrupts before the call and enable 116 * interrupts after return. 117 */ 118 static void acpi_safe_halt(void) 119 { 120 if (!tif_need_resched()) { 121 safe_halt(); 122 local_irq_disable(); 123 } 124 } 125 126 #ifdef ARCH_APICTIMER_STOPS_ON_C3 127 128 /* 129 * Some BIOS implementations switch to C3 in the published C2 state. 130 * This seems to be a common problem on AMD boxen, but other vendors 131 * are affected too. We pick the most conservative approach: we assume 132 * that the local APIC stops in both C2 and C3. 133 */ 134 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 135 struct acpi_processor_cx *cx) 136 { 137 struct acpi_processor_power *pwr = &pr->power; 138 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 139 140 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 141 return; 142 143 if (amd_e400_c1e_detected) 144 type = ACPI_STATE_C1; 145 146 /* 147 * Check, if one of the previous states already marked the lapic 148 * unstable 149 */ 150 if (pwr->timer_broadcast_on_state < state) 151 return; 152 153 if (cx->type >= type) 154 pr->power.timer_broadcast_on_state = state; 155 } 156 157 static void __lapic_timer_propagate_broadcast(void *arg) 158 { 159 struct acpi_processor *pr = (struct acpi_processor *) arg; 160 161 if (pr->power.timer_broadcast_on_state < INT_MAX) 162 tick_broadcast_enable(); 163 else 164 tick_broadcast_disable(); 165 } 166 167 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 168 { 169 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 170 (void *)pr, 1); 171 } 172 173 /* Power(C) State timer broadcast control */ 174 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 175 struct acpi_processor_cx *cx, 176 int broadcast) 177 { 178 int state = cx - pr->power.states; 179 180 if (state >= pr->power.timer_broadcast_on_state) { 181 if (broadcast) 182 tick_broadcast_enter(); 183 else 184 tick_broadcast_exit(); 185 } 186 } 187 188 #else 189 190 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 191 struct acpi_processor_cx *cstate) { } 192 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 193 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 194 struct acpi_processor_cx *cx, 195 int broadcast) 196 { 197 } 198 199 #endif 200 201 #if defined(CONFIG_X86) 202 static void tsc_check_state(int state) 203 { 204 switch (boot_cpu_data.x86_vendor) { 205 case X86_VENDOR_AMD: 206 case X86_VENDOR_INTEL: 207 /* 208 * AMD Fam10h TSC will tick in all 209 * C/P/S0/S1 states when this bit is set. 210 */ 211 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 212 return; 213 214 /*FALL THROUGH*/ 215 default: 216 /* TSC could halt in idle, so notify users */ 217 if (state > ACPI_STATE_C1) 218 mark_tsc_unstable("TSC halts in idle"); 219 } 220 } 221 #else 222 static void tsc_check_state(int state) { return; } 223 #endif 224 225 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 226 { 227 228 if (!pr->pblk) 229 return -ENODEV; 230 231 /* if info is obtained from pblk/fadt, type equals state */ 232 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 233 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 234 235 #ifndef CONFIG_HOTPLUG_CPU 236 /* 237 * Check for P_LVL2_UP flag before entering C2 and above on 238 * an SMP system. 239 */ 240 if ((num_online_cpus() > 1) && 241 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 242 return -ENODEV; 243 #endif 244 245 /* determine C2 and C3 address from pblk */ 246 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 247 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 248 249 /* determine latencies from FADT */ 250 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 251 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 252 253 /* 254 * FADT specified C2 latency must be less than or equal to 255 * 100 microseconds. 256 */ 257 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 258 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 259 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 260 /* invalidate C2 */ 261 pr->power.states[ACPI_STATE_C2].address = 0; 262 } 263 264 /* 265 * FADT supplied C3 latency must be less than or equal to 266 * 1000 microseconds. 267 */ 268 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 269 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 270 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 271 /* invalidate C3 */ 272 pr->power.states[ACPI_STATE_C3].address = 0; 273 } 274 275 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 276 "lvl2[0x%08x] lvl3[0x%08x]\n", 277 pr->power.states[ACPI_STATE_C2].address, 278 pr->power.states[ACPI_STATE_C3].address)); 279 280 return 0; 281 } 282 283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 284 { 285 if (!pr->power.states[ACPI_STATE_C1].valid) { 286 /* set the first C-State to C1 */ 287 /* all processors need to support C1 */ 288 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 289 pr->power.states[ACPI_STATE_C1].valid = 1; 290 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 291 } 292 /* the C0 state only exists as a filler in our array */ 293 pr->power.states[ACPI_STATE_C0].valid = 1; 294 return 0; 295 } 296 297 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 298 { 299 acpi_status status; 300 u64 count; 301 int current_count; 302 int i, ret = 0; 303 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 304 union acpi_object *cst; 305 306 if (nocst) 307 return -ENODEV; 308 309 current_count = 0; 310 311 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 312 if (ACPI_FAILURE(status)) { 313 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 314 return -ENODEV; 315 } 316 317 cst = buffer.pointer; 318 319 /* There must be at least 2 elements */ 320 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 321 pr_err("not enough elements in _CST\n"); 322 ret = -EFAULT; 323 goto end; 324 } 325 326 count = cst->package.elements[0].integer.value; 327 328 /* Validate number of power states. */ 329 if (count < 1 || count != cst->package.count - 1) { 330 pr_err("count given by _CST is not valid\n"); 331 ret = -EFAULT; 332 goto end; 333 } 334 335 /* Tell driver that at least _CST is supported. */ 336 pr->flags.has_cst = 1; 337 338 for (i = 1; i <= count; i++) { 339 union acpi_object *element; 340 union acpi_object *obj; 341 struct acpi_power_register *reg; 342 struct acpi_processor_cx cx; 343 344 memset(&cx, 0, sizeof(cx)); 345 346 element = &(cst->package.elements[i]); 347 if (element->type != ACPI_TYPE_PACKAGE) 348 continue; 349 350 if (element->package.count != 4) 351 continue; 352 353 obj = &(element->package.elements[0]); 354 355 if (obj->type != ACPI_TYPE_BUFFER) 356 continue; 357 358 reg = (struct acpi_power_register *)obj->buffer.pointer; 359 360 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 361 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 362 continue; 363 364 /* There should be an easy way to extract an integer... */ 365 obj = &(element->package.elements[1]); 366 if (obj->type != ACPI_TYPE_INTEGER) 367 continue; 368 369 cx.type = obj->integer.value; 370 /* 371 * Some buggy BIOSes won't list C1 in _CST - 372 * Let acpi_processor_get_power_info_default() handle them later 373 */ 374 if (i == 1 && cx.type != ACPI_STATE_C1) 375 current_count++; 376 377 cx.address = reg->address; 378 cx.index = current_count + 1; 379 380 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 381 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 382 if (acpi_processor_ffh_cstate_probe 383 (pr->id, &cx, reg) == 0) { 384 cx.entry_method = ACPI_CSTATE_FFH; 385 } else if (cx.type == ACPI_STATE_C1) { 386 /* 387 * C1 is a special case where FIXED_HARDWARE 388 * can be handled in non-MWAIT way as well. 389 * In that case, save this _CST entry info. 390 * Otherwise, ignore this info and continue. 391 */ 392 cx.entry_method = ACPI_CSTATE_HALT; 393 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 394 } else { 395 continue; 396 } 397 if (cx.type == ACPI_STATE_C1 && 398 (boot_option_idle_override == IDLE_NOMWAIT)) { 399 /* 400 * In most cases the C1 space_id obtained from 401 * _CST object is FIXED_HARDWARE access mode. 402 * But when the option of idle=halt is added, 403 * the entry_method type should be changed from 404 * CSTATE_FFH to CSTATE_HALT. 405 * When the option of idle=nomwait is added, 406 * the C1 entry_method type should be 407 * CSTATE_HALT. 408 */ 409 cx.entry_method = ACPI_CSTATE_HALT; 410 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 411 } 412 } else { 413 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 414 cx.address); 415 } 416 417 if (cx.type == ACPI_STATE_C1) { 418 cx.valid = 1; 419 } 420 421 obj = &(element->package.elements[2]); 422 if (obj->type != ACPI_TYPE_INTEGER) 423 continue; 424 425 cx.latency = obj->integer.value; 426 427 obj = &(element->package.elements[3]); 428 if (obj->type != ACPI_TYPE_INTEGER) 429 continue; 430 431 current_count++; 432 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 433 434 /* 435 * We support total ACPI_PROCESSOR_MAX_POWER - 1 436 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 437 */ 438 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 439 pr_warn("Limiting number of power states to max (%d)\n", 440 ACPI_PROCESSOR_MAX_POWER); 441 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 442 break; 443 } 444 } 445 446 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 447 current_count)); 448 449 /* Validate number of power states discovered */ 450 if (current_count < 2) 451 ret = -EFAULT; 452 453 end: 454 kfree(buffer.pointer); 455 456 return ret; 457 } 458 459 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 460 struct acpi_processor_cx *cx) 461 { 462 static int bm_check_flag = -1; 463 static int bm_control_flag = -1; 464 465 466 if (!cx->address) 467 return; 468 469 /* 470 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 471 * DMA transfers are used by any ISA device to avoid livelock. 472 * Note that we could disable Type-F DMA (as recommended by 473 * the erratum), but this is known to disrupt certain ISA 474 * devices thus we take the conservative approach. 475 */ 476 else if (errata.piix4.fdma) { 477 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 478 "C3 not supported on PIIX4 with Type-F DMA\n")); 479 return; 480 } 481 482 /* All the logic here assumes flags.bm_check is same across all CPUs */ 483 if (bm_check_flag == -1) { 484 /* Determine whether bm_check is needed based on CPU */ 485 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 486 bm_check_flag = pr->flags.bm_check; 487 bm_control_flag = pr->flags.bm_control; 488 } else { 489 pr->flags.bm_check = bm_check_flag; 490 pr->flags.bm_control = bm_control_flag; 491 } 492 493 if (pr->flags.bm_check) { 494 if (!pr->flags.bm_control) { 495 if (pr->flags.has_cst != 1) { 496 /* bus mastering control is necessary */ 497 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 498 "C3 support requires BM control\n")); 499 return; 500 } else { 501 /* Here we enter C3 without bus mastering */ 502 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 503 "C3 support without BM control\n")); 504 } 505 } 506 } else { 507 /* 508 * WBINVD should be set in fadt, for C3 state to be 509 * supported on when bm_check is not required. 510 */ 511 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 512 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 513 "Cache invalidation should work properly" 514 " for C3 to be enabled on SMP systems\n")); 515 return; 516 } 517 } 518 519 /* 520 * Otherwise we've met all of our C3 requirements. 521 * Normalize the C3 latency to expidite policy. Enable 522 * checking of bus mastering status (bm_check) so we can 523 * use this in our C3 policy 524 */ 525 cx->valid = 1; 526 527 /* 528 * On older chipsets, BM_RLD needs to be set 529 * in order for Bus Master activity to wake the 530 * system from C3. Newer chipsets handle DMA 531 * during C3 automatically and BM_RLD is a NOP. 532 * In either case, the proper way to 533 * handle BM_RLD is to set it and leave it set. 534 */ 535 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 536 537 return; 538 } 539 540 static int acpi_processor_power_verify(struct acpi_processor *pr) 541 { 542 unsigned int i; 543 unsigned int working = 0; 544 545 pr->power.timer_broadcast_on_state = INT_MAX; 546 547 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 548 struct acpi_processor_cx *cx = &pr->power.states[i]; 549 550 switch (cx->type) { 551 case ACPI_STATE_C1: 552 cx->valid = 1; 553 break; 554 555 case ACPI_STATE_C2: 556 if (!cx->address) 557 break; 558 cx->valid = 1; 559 break; 560 561 case ACPI_STATE_C3: 562 acpi_processor_power_verify_c3(pr, cx); 563 break; 564 } 565 if (!cx->valid) 566 continue; 567 568 lapic_timer_check_state(i, pr, cx); 569 tsc_check_state(cx->type); 570 working++; 571 } 572 573 lapic_timer_propagate_broadcast(pr); 574 575 return (working); 576 } 577 578 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 579 { 580 unsigned int i; 581 int result; 582 583 584 /* NOTE: the idle thread may not be running while calling 585 * this function */ 586 587 /* Zero initialize all the C-states info. */ 588 memset(pr->power.states, 0, sizeof(pr->power.states)); 589 590 result = acpi_processor_get_power_info_cst(pr); 591 if (result == -ENODEV) 592 result = acpi_processor_get_power_info_fadt(pr); 593 594 if (result) 595 return result; 596 597 acpi_processor_get_power_info_default(pr); 598 599 pr->power.count = acpi_processor_power_verify(pr); 600 601 /* 602 * if one state of type C2 or C3 is available, mark this 603 * CPU as being "idle manageable" 604 */ 605 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 606 if (pr->power.states[i].valid) { 607 pr->power.count = i; 608 if (pr->power.states[i].type >= ACPI_STATE_C2) 609 pr->flags.power = 1; 610 } 611 } 612 613 return 0; 614 } 615 616 /** 617 * acpi_idle_bm_check - checks if bus master activity was detected 618 */ 619 static int acpi_idle_bm_check(void) 620 { 621 u32 bm_status = 0; 622 623 if (bm_check_disable) 624 return 0; 625 626 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 627 if (bm_status) 628 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 629 /* 630 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 631 * the true state of bus mastering activity; forcing us to 632 * manually check the BMIDEA bit of each IDE channel. 633 */ 634 else if (errata.piix4.bmisx) { 635 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 636 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 637 bm_status = 1; 638 } 639 return bm_status; 640 } 641 642 /** 643 * acpi_idle_do_entry - enter idle state using the appropriate method 644 * @cx: cstate data 645 * 646 * Caller disables interrupt before call and enables interrupt after return. 647 */ 648 static void acpi_idle_do_entry(struct acpi_processor_cx *cx) 649 { 650 if (cx->entry_method == ACPI_CSTATE_FFH) { 651 /* Call into architectural FFH based C-state */ 652 acpi_processor_ffh_cstate_enter(cx); 653 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 654 acpi_safe_halt(); 655 } else { 656 /* IO port based C-state */ 657 inb(cx->address); 658 /* Dummy wait op - must do something useless after P_LVL2 read 659 because chipsets cannot guarantee that STPCLK# signal 660 gets asserted in time to freeze execution properly. */ 661 inl(acpi_gbl_FADT.xpm_timer_block.address); 662 } 663 } 664 665 /** 666 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 667 * @dev: the target CPU 668 * @index: the index of suggested state 669 */ 670 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 671 { 672 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 673 674 ACPI_FLUSH_CPU_CACHE(); 675 676 while (1) { 677 678 if (cx->entry_method == ACPI_CSTATE_HALT) 679 safe_halt(); 680 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 681 inb(cx->address); 682 /* See comment in acpi_idle_do_entry() */ 683 inl(acpi_gbl_FADT.xpm_timer_block.address); 684 } else 685 return -ENODEV; 686 } 687 688 /* Never reached */ 689 return 0; 690 } 691 692 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 693 { 694 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 695 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 696 } 697 698 static int c3_cpu_count; 699 static DEFINE_RAW_SPINLOCK(c3_lock); 700 701 /** 702 * acpi_idle_enter_bm - enters C3 with proper BM handling 703 * @pr: Target processor 704 * @cx: Target state context 705 * @timer_bc: Whether or not to change timer mode to broadcast 706 */ 707 static void acpi_idle_enter_bm(struct acpi_processor *pr, 708 struct acpi_processor_cx *cx, bool timer_bc) 709 { 710 acpi_unlazy_tlb(smp_processor_id()); 711 712 /* 713 * Must be done before busmaster disable as we might need to 714 * access HPET ! 715 */ 716 if (timer_bc) 717 lapic_timer_state_broadcast(pr, cx, 1); 718 719 /* 720 * disable bus master 721 * bm_check implies we need ARB_DIS 722 * bm_control implies whether we can do ARB_DIS 723 * 724 * That leaves a case where bm_check is set and bm_control is 725 * not set. In that case we cannot do much, we enter C3 726 * without doing anything. 727 */ 728 if (pr->flags.bm_control) { 729 raw_spin_lock(&c3_lock); 730 c3_cpu_count++; 731 /* Disable bus master arbitration when all CPUs are in C3 */ 732 if (c3_cpu_count == num_online_cpus()) 733 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 734 raw_spin_unlock(&c3_lock); 735 } 736 737 acpi_idle_do_entry(cx); 738 739 /* Re-enable bus master arbitration */ 740 if (pr->flags.bm_control) { 741 raw_spin_lock(&c3_lock); 742 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 743 c3_cpu_count--; 744 raw_spin_unlock(&c3_lock); 745 } 746 747 if (timer_bc) 748 lapic_timer_state_broadcast(pr, cx, 0); 749 } 750 751 static int acpi_idle_enter(struct cpuidle_device *dev, 752 struct cpuidle_driver *drv, int index) 753 { 754 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 755 struct acpi_processor *pr; 756 757 pr = __this_cpu_read(processors); 758 if (unlikely(!pr)) 759 return -EINVAL; 760 761 if (cx->type != ACPI_STATE_C1) { 762 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 763 index = CPUIDLE_DRIVER_STATE_START; 764 cx = per_cpu(acpi_cstate[index], dev->cpu); 765 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 766 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 767 acpi_idle_enter_bm(pr, cx, true); 768 return index; 769 } else if (drv->safe_state_index >= 0) { 770 index = drv->safe_state_index; 771 cx = per_cpu(acpi_cstate[index], dev->cpu); 772 } else { 773 acpi_safe_halt(); 774 return -EBUSY; 775 } 776 } 777 } 778 779 lapic_timer_state_broadcast(pr, cx, 1); 780 781 if (cx->type == ACPI_STATE_C3) 782 ACPI_FLUSH_CPU_CACHE(); 783 784 acpi_idle_do_entry(cx); 785 786 lapic_timer_state_broadcast(pr, cx, 0); 787 788 return index; 789 } 790 791 static void acpi_idle_enter_freeze(struct cpuidle_device *dev, 792 struct cpuidle_driver *drv, int index) 793 { 794 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 795 796 if (cx->type == ACPI_STATE_C3) { 797 struct acpi_processor *pr = __this_cpu_read(processors); 798 799 if (unlikely(!pr)) 800 return; 801 802 if (pr->flags.bm_check) { 803 acpi_idle_enter_bm(pr, cx, false); 804 return; 805 } else { 806 ACPI_FLUSH_CPU_CACHE(); 807 } 808 } 809 acpi_idle_do_entry(cx); 810 } 811 812 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 813 struct cpuidle_device *dev) 814 { 815 int i, count = CPUIDLE_DRIVER_STATE_START; 816 struct acpi_processor_cx *cx; 817 818 if (max_cstate == 0) 819 max_cstate = 1; 820 821 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 822 cx = &pr->power.states[i]; 823 824 if (!cx->valid) 825 continue; 826 827 per_cpu(acpi_cstate[count], dev->cpu) = cx; 828 829 count++; 830 if (count == CPUIDLE_STATE_MAX) 831 break; 832 } 833 834 if (!count) 835 return -EINVAL; 836 837 return 0; 838 } 839 840 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 841 { 842 int i, count = CPUIDLE_DRIVER_STATE_START; 843 struct acpi_processor_cx *cx; 844 struct cpuidle_state *state; 845 struct cpuidle_driver *drv = &acpi_idle_driver; 846 847 if (max_cstate == 0) 848 max_cstate = 1; 849 850 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 851 cx = &pr->power.states[i]; 852 853 if (!cx->valid) 854 continue; 855 856 state = &drv->states[count]; 857 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 858 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 859 state->exit_latency = cx->latency; 860 state->target_residency = cx->latency * latency_factor; 861 state->enter = acpi_idle_enter; 862 863 state->flags = 0; 864 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 865 state->enter_dead = acpi_idle_play_dead; 866 drv->safe_state_index = count; 867 } 868 /* 869 * Halt-induced C1 is not good for ->enter_freeze, because it 870 * re-enables interrupts on exit. Moreover, C1 is generally not 871 * particularly interesting from the suspend-to-idle angle, so 872 * avoid C1 and the situations in which we may need to fall back 873 * to it altogether. 874 */ 875 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 876 state->enter_freeze = acpi_idle_enter_freeze; 877 878 count++; 879 if (count == CPUIDLE_STATE_MAX) 880 break; 881 } 882 883 drv->state_count = count; 884 885 if (!count) 886 return -EINVAL; 887 888 return 0; 889 } 890 891 static inline void acpi_processor_cstate_first_run_checks(void) 892 { 893 acpi_status status; 894 static int first_run; 895 896 if (first_run) 897 return; 898 dmi_check_system(processor_power_dmi_table); 899 max_cstate = acpi_processor_cstate_check(max_cstate); 900 if (max_cstate < ACPI_C_STATES_MAX) 901 pr_notice("ACPI: processor limited to max C-state %d\n", 902 max_cstate); 903 first_run++; 904 905 if (acpi_gbl_FADT.cst_control && !nocst) { 906 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 907 acpi_gbl_FADT.cst_control, 8); 908 if (ACPI_FAILURE(status)) 909 ACPI_EXCEPTION((AE_INFO, status, 910 "Notifying BIOS of _CST ability failed")); 911 } 912 } 913 #else 914 915 static inline int disabled_by_idle_boot_param(void) { return 0; } 916 static inline void acpi_processor_cstate_first_run_checks(void) { } 917 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 918 { 919 return -ENODEV; 920 } 921 922 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 923 struct cpuidle_device *dev) 924 { 925 return -EINVAL; 926 } 927 928 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 929 { 930 return -EINVAL; 931 } 932 933 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 934 935 struct acpi_lpi_states_array { 936 unsigned int size; 937 unsigned int composite_states_size; 938 struct acpi_lpi_state *entries; 939 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 940 }; 941 942 static int obj_get_integer(union acpi_object *obj, u32 *value) 943 { 944 if (obj->type != ACPI_TYPE_INTEGER) 945 return -EINVAL; 946 947 *value = obj->integer.value; 948 return 0; 949 } 950 951 static int acpi_processor_evaluate_lpi(acpi_handle handle, 952 struct acpi_lpi_states_array *info) 953 { 954 acpi_status status; 955 int ret = 0; 956 int pkg_count, state_idx = 1, loop; 957 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 958 union acpi_object *lpi_data; 959 struct acpi_lpi_state *lpi_state; 960 961 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 962 if (ACPI_FAILURE(status)) { 963 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 964 return -ENODEV; 965 } 966 967 lpi_data = buffer.pointer; 968 969 /* There must be at least 4 elements = 3 elements + 1 package */ 970 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 971 lpi_data->package.count < 4) { 972 pr_debug("not enough elements in _LPI\n"); 973 ret = -ENODATA; 974 goto end; 975 } 976 977 pkg_count = lpi_data->package.elements[2].integer.value; 978 979 /* Validate number of power states. */ 980 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 981 pr_debug("count given by _LPI is not valid\n"); 982 ret = -ENODATA; 983 goto end; 984 } 985 986 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 987 if (!lpi_state) { 988 ret = -ENOMEM; 989 goto end; 990 } 991 992 info->size = pkg_count; 993 info->entries = lpi_state; 994 995 /* LPI States start at index 3 */ 996 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 997 union acpi_object *element, *pkg_elem, *obj; 998 999 element = &lpi_data->package.elements[loop]; 1000 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1001 continue; 1002 1003 pkg_elem = element->package.elements; 1004 1005 obj = pkg_elem + 6; 1006 if (obj->type == ACPI_TYPE_BUFFER) { 1007 struct acpi_power_register *reg; 1008 1009 reg = (struct acpi_power_register *)obj->buffer.pointer; 1010 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1011 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1012 continue; 1013 1014 lpi_state->address = reg->address; 1015 lpi_state->entry_method = 1016 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1017 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1018 } else if (obj->type == ACPI_TYPE_INTEGER) { 1019 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1020 lpi_state->address = obj->integer.value; 1021 } else { 1022 continue; 1023 } 1024 1025 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1026 1027 obj = pkg_elem + 9; 1028 if (obj->type == ACPI_TYPE_STRING) 1029 strlcpy(lpi_state->desc, obj->string.pointer, 1030 ACPI_CX_DESC_LEN); 1031 1032 lpi_state->index = state_idx; 1033 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1034 pr_debug("No min. residency found, assuming 10 us\n"); 1035 lpi_state->min_residency = 10; 1036 } 1037 1038 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1039 pr_debug("No wakeup residency found, assuming 10 us\n"); 1040 lpi_state->wake_latency = 10; 1041 } 1042 1043 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1044 lpi_state->flags = 0; 1045 1046 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1047 lpi_state->arch_flags = 0; 1048 1049 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1050 lpi_state->res_cnt_freq = 1; 1051 1052 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1053 lpi_state->enable_parent_state = 0; 1054 } 1055 1056 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1057 end: 1058 kfree(buffer.pointer); 1059 return ret; 1060 } 1061 1062 /* 1063 * flat_state_cnt - the number of composite LPI states after the process of flattening 1064 */ 1065 static int flat_state_cnt; 1066 1067 /** 1068 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1069 * 1070 * @local: local LPI state 1071 * @parent: parent LPI state 1072 * @result: composite LPI state 1073 */ 1074 static bool combine_lpi_states(struct acpi_lpi_state *local, 1075 struct acpi_lpi_state *parent, 1076 struct acpi_lpi_state *result) 1077 { 1078 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1079 if (!parent->address) /* 0 means autopromotable */ 1080 return false; 1081 result->address = local->address + parent->address; 1082 } else { 1083 result->address = parent->address; 1084 } 1085 1086 result->min_residency = max(local->min_residency, parent->min_residency); 1087 result->wake_latency = local->wake_latency + parent->wake_latency; 1088 result->enable_parent_state = parent->enable_parent_state; 1089 result->entry_method = local->entry_method; 1090 1091 result->flags = parent->flags; 1092 result->arch_flags = parent->arch_flags; 1093 result->index = parent->index; 1094 1095 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1096 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1097 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1098 return true; 1099 } 1100 1101 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1102 1103 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1104 struct acpi_lpi_state *t) 1105 { 1106 curr_level->composite_states[curr_level->composite_states_size++] = t; 1107 } 1108 1109 static int flatten_lpi_states(struct acpi_processor *pr, 1110 struct acpi_lpi_states_array *curr_level, 1111 struct acpi_lpi_states_array *prev_level) 1112 { 1113 int i, j, state_count = curr_level->size; 1114 struct acpi_lpi_state *p, *t = curr_level->entries; 1115 1116 curr_level->composite_states_size = 0; 1117 for (j = 0; j < state_count; j++, t++) { 1118 struct acpi_lpi_state *flpi; 1119 1120 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1121 continue; 1122 1123 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1124 pr_warn("Limiting number of LPI states to max (%d)\n", 1125 ACPI_PROCESSOR_MAX_POWER); 1126 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1127 break; 1128 } 1129 1130 flpi = &pr->power.lpi_states[flat_state_cnt]; 1131 1132 if (!prev_level) { /* leaf/processor node */ 1133 memcpy(flpi, t, sizeof(*t)); 1134 stash_composite_state(curr_level, flpi); 1135 flat_state_cnt++; 1136 continue; 1137 } 1138 1139 for (i = 0; i < prev_level->composite_states_size; i++) { 1140 p = prev_level->composite_states[i]; 1141 if (t->index <= p->enable_parent_state && 1142 combine_lpi_states(p, t, flpi)) { 1143 stash_composite_state(curr_level, flpi); 1144 flat_state_cnt++; 1145 flpi++; 1146 } 1147 } 1148 } 1149 1150 kfree(curr_level->entries); 1151 return 0; 1152 } 1153 1154 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1155 { 1156 int ret, i; 1157 acpi_status status; 1158 acpi_handle handle = pr->handle, pr_ahandle; 1159 struct acpi_device *d = NULL; 1160 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1161 1162 if (!osc_pc_lpi_support_confirmed) 1163 return -EOPNOTSUPP; 1164 1165 if (!acpi_has_method(handle, "_LPI")) 1166 return -EINVAL; 1167 1168 flat_state_cnt = 0; 1169 prev = &info[0]; 1170 curr = &info[1]; 1171 handle = pr->handle; 1172 ret = acpi_processor_evaluate_lpi(handle, prev); 1173 if (ret) 1174 return ret; 1175 flatten_lpi_states(pr, prev, NULL); 1176 1177 status = acpi_get_parent(handle, &pr_ahandle); 1178 while (ACPI_SUCCESS(status)) { 1179 acpi_bus_get_device(pr_ahandle, &d); 1180 handle = pr_ahandle; 1181 1182 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1183 break; 1184 1185 /* can be optional ? */ 1186 if (!acpi_has_method(handle, "_LPI")) 1187 break; 1188 1189 ret = acpi_processor_evaluate_lpi(handle, curr); 1190 if (ret) 1191 break; 1192 1193 /* flatten all the LPI states in this level of hierarchy */ 1194 flatten_lpi_states(pr, curr, prev); 1195 1196 tmp = prev, prev = curr, curr = tmp; 1197 1198 status = acpi_get_parent(handle, &pr_ahandle); 1199 } 1200 1201 pr->power.count = flat_state_cnt; 1202 /* reset the index after flattening */ 1203 for (i = 0; i < pr->power.count; i++) 1204 pr->power.lpi_states[i].index = i; 1205 1206 /* Tell driver that _LPI is supported. */ 1207 pr->flags.has_lpi = 1; 1208 pr->flags.power = 1; 1209 1210 return 0; 1211 } 1212 1213 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1214 { 1215 return -ENODEV; 1216 } 1217 1218 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1219 { 1220 return -ENODEV; 1221 } 1222 1223 /** 1224 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1225 * @dev: the target CPU 1226 * @drv: cpuidle driver containing cpuidle state info 1227 * @index: index of target state 1228 * 1229 * Return: 0 for success or negative value for error 1230 */ 1231 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1232 struct cpuidle_driver *drv, int index) 1233 { 1234 struct acpi_processor *pr; 1235 struct acpi_lpi_state *lpi; 1236 1237 pr = __this_cpu_read(processors); 1238 1239 if (unlikely(!pr)) 1240 return -EINVAL; 1241 1242 lpi = &pr->power.lpi_states[index]; 1243 if (lpi->entry_method == ACPI_CSTATE_FFH) 1244 return acpi_processor_ffh_lpi_enter(lpi); 1245 1246 return -EINVAL; 1247 } 1248 1249 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1250 { 1251 int i; 1252 struct acpi_lpi_state *lpi; 1253 struct cpuidle_state *state; 1254 struct cpuidle_driver *drv = &acpi_idle_driver; 1255 1256 if (!pr->flags.has_lpi) 1257 return -EOPNOTSUPP; 1258 1259 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1260 lpi = &pr->power.lpi_states[i]; 1261 1262 state = &drv->states[i]; 1263 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1264 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1265 state->exit_latency = lpi->wake_latency; 1266 state->target_residency = lpi->min_residency; 1267 if (lpi->arch_flags) 1268 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1269 state->enter = acpi_idle_lpi_enter; 1270 drv->safe_state_index = i; 1271 } 1272 1273 drv->state_count = i; 1274 1275 return 0; 1276 } 1277 1278 /** 1279 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1280 * global state data i.e. idle routines 1281 * 1282 * @pr: the ACPI processor 1283 */ 1284 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1285 { 1286 int i; 1287 struct cpuidle_driver *drv = &acpi_idle_driver; 1288 1289 if (!pr->flags.power_setup_done || !pr->flags.power) 1290 return -EINVAL; 1291 1292 drv->safe_state_index = -1; 1293 for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1294 drv->states[i].name[0] = '\0'; 1295 drv->states[i].desc[0] = '\0'; 1296 } 1297 1298 if (pr->flags.has_lpi) 1299 return acpi_processor_setup_lpi_states(pr); 1300 1301 return acpi_processor_setup_cstates(pr); 1302 } 1303 1304 /** 1305 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1306 * device i.e. per-cpu data 1307 * 1308 * @pr: the ACPI processor 1309 * @dev : the cpuidle device 1310 */ 1311 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1312 struct cpuidle_device *dev) 1313 { 1314 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1315 return -EINVAL; 1316 1317 dev->cpu = pr->id; 1318 if (pr->flags.has_lpi) 1319 return acpi_processor_ffh_lpi_probe(pr->id); 1320 1321 return acpi_processor_setup_cpuidle_cx(pr, dev); 1322 } 1323 1324 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1325 { 1326 int ret; 1327 1328 ret = acpi_processor_get_lpi_info(pr); 1329 if (ret) 1330 ret = acpi_processor_get_cstate_info(pr); 1331 1332 return ret; 1333 } 1334 1335 int acpi_processor_hotplug(struct acpi_processor *pr) 1336 { 1337 int ret = 0; 1338 struct cpuidle_device *dev; 1339 1340 if (disabled_by_idle_boot_param()) 1341 return 0; 1342 1343 if (!pr->flags.power_setup_done) 1344 return -ENODEV; 1345 1346 dev = per_cpu(acpi_cpuidle_device, pr->id); 1347 cpuidle_pause_and_lock(); 1348 cpuidle_disable_device(dev); 1349 ret = acpi_processor_get_power_info(pr); 1350 if (!ret && pr->flags.power) { 1351 acpi_processor_setup_cpuidle_dev(pr, dev); 1352 ret = cpuidle_enable_device(dev); 1353 } 1354 cpuidle_resume_and_unlock(); 1355 1356 return ret; 1357 } 1358 1359 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1360 { 1361 int cpu; 1362 struct acpi_processor *_pr; 1363 struct cpuidle_device *dev; 1364 1365 if (disabled_by_idle_boot_param()) 1366 return 0; 1367 1368 if (!pr->flags.power_setup_done) 1369 return -ENODEV; 1370 1371 /* 1372 * FIXME: Design the ACPI notification to make it once per 1373 * system instead of once per-cpu. This condition is a hack 1374 * to make the code that updates C-States be called once. 1375 */ 1376 1377 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1378 1379 /* Protect against cpu-hotplug */ 1380 get_online_cpus(); 1381 cpuidle_pause_and_lock(); 1382 1383 /* Disable all cpuidle devices */ 1384 for_each_online_cpu(cpu) { 1385 _pr = per_cpu(processors, cpu); 1386 if (!_pr || !_pr->flags.power_setup_done) 1387 continue; 1388 dev = per_cpu(acpi_cpuidle_device, cpu); 1389 cpuidle_disable_device(dev); 1390 } 1391 1392 /* Populate Updated C-state information */ 1393 acpi_processor_get_power_info(pr); 1394 acpi_processor_setup_cpuidle_states(pr); 1395 1396 /* Enable all cpuidle devices */ 1397 for_each_online_cpu(cpu) { 1398 _pr = per_cpu(processors, cpu); 1399 if (!_pr || !_pr->flags.power_setup_done) 1400 continue; 1401 acpi_processor_get_power_info(_pr); 1402 if (_pr->flags.power) { 1403 dev = per_cpu(acpi_cpuidle_device, cpu); 1404 acpi_processor_setup_cpuidle_dev(_pr, dev); 1405 cpuidle_enable_device(dev); 1406 } 1407 } 1408 cpuidle_resume_and_unlock(); 1409 put_online_cpus(); 1410 } 1411 1412 return 0; 1413 } 1414 1415 static int acpi_processor_registered; 1416 1417 int acpi_processor_power_init(struct acpi_processor *pr) 1418 { 1419 int retval; 1420 struct cpuidle_device *dev; 1421 1422 if (disabled_by_idle_boot_param()) 1423 return 0; 1424 1425 acpi_processor_cstate_first_run_checks(); 1426 1427 if (!acpi_processor_get_power_info(pr)) 1428 pr->flags.power_setup_done = 1; 1429 1430 /* 1431 * Install the idle handler if processor power management is supported. 1432 * Note that we use previously set idle handler will be used on 1433 * platforms that only support C1. 1434 */ 1435 if (pr->flags.power) { 1436 /* Register acpi_idle_driver if not already registered */ 1437 if (!acpi_processor_registered) { 1438 acpi_processor_setup_cpuidle_states(pr); 1439 retval = cpuidle_register_driver(&acpi_idle_driver); 1440 if (retval) 1441 return retval; 1442 pr_debug("%s registered with cpuidle\n", 1443 acpi_idle_driver.name); 1444 } 1445 1446 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1447 if (!dev) 1448 return -ENOMEM; 1449 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1450 1451 acpi_processor_setup_cpuidle_dev(pr, dev); 1452 1453 /* Register per-cpu cpuidle_device. Cpuidle driver 1454 * must already be registered before registering device 1455 */ 1456 retval = cpuidle_register_device(dev); 1457 if (retval) { 1458 if (acpi_processor_registered == 0) 1459 cpuidle_unregister_driver(&acpi_idle_driver); 1460 return retval; 1461 } 1462 acpi_processor_registered++; 1463 } 1464 return 0; 1465 } 1466 1467 int acpi_processor_power_exit(struct acpi_processor *pr) 1468 { 1469 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1470 1471 if (disabled_by_idle_boot_param()) 1472 return 0; 1473 1474 if (pr->flags.power) { 1475 cpuidle_unregister_device(dev); 1476 acpi_processor_registered--; 1477 if (acpi_processor_registered == 0) 1478 cpuidle_unregister_driver(&acpi_idle_driver); 1479 } 1480 1481 pr->flags.power_setup_done = 0; 1482 return 0; 1483 } 1484