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 <linux/cpu.h> 35 #include <acpi/processor.h> 36 37 /* 38 * Include the apic definitions for x86 to have the APIC timer related defines 39 * available also for UP (on SMP it gets magically included via linux/smp.h). 40 * asm/acpi.h is not an option, as it would require more include magic. Also 41 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 42 */ 43 #ifdef CONFIG_X86 44 #include <asm/apic.h> 45 #endif 46 47 #define ACPI_PROCESSOR_CLASS "processor" 48 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 49 ACPI_MODULE_NAME("processor_idle"); 50 51 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) 52 53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 54 module_param(max_cstate, uint, 0000); 55 static unsigned int nocst __read_mostly; 56 module_param(nocst, uint, 0000); 57 static int bm_check_disable __read_mostly; 58 module_param(bm_check_disable, uint, 0000); 59 60 static unsigned int latency_factor __read_mostly = 2; 61 module_param(latency_factor, uint, 0644); 62 63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 64 65 struct cpuidle_driver acpi_idle_driver = { 66 .name = "acpi_idle", 67 .owner = THIS_MODULE, 68 }; 69 70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 71 static 72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 73 74 static int disabled_by_idle_boot_param(void) 75 { 76 return boot_option_idle_override == IDLE_POLL || 77 boot_option_idle_override == IDLE_HALT; 78 } 79 80 /* 81 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 82 * For now disable this. Probably a bug somewhere else. 83 * 84 * To skip this limit, boot/load with a large max_cstate limit. 85 */ 86 static int set_max_cstate(const struct dmi_system_id *id) 87 { 88 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 89 return 0; 90 91 pr_notice("%s detected - limiting to C%ld max_cstate." 92 " Override with \"processor.max_cstate=%d\"\n", id->ident, 93 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 94 95 max_cstate = (long)id->driver_data; 96 97 return 0; 98 } 99 100 static const struct dmi_system_id processor_power_dmi_table[] = { 101 { set_max_cstate, "Clevo 5600D", { 102 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 103 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 104 (void *)2}, 105 { set_max_cstate, "Pavilion zv5000", { 106 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 107 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 108 (void *)1}, 109 { set_max_cstate, "Asus L8400B", { 110 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 111 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 112 (void *)1}, 113 {}, 114 }; 115 116 117 /* 118 * Callers should disable interrupts before the call and enable 119 * interrupts after return. 120 */ 121 static void __cpuidle acpi_safe_halt(void) 122 { 123 if (!tif_need_resched()) { 124 safe_halt(); 125 local_irq_disable(); 126 } 127 } 128 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3 130 131 /* 132 * Some BIOS implementations switch to C3 in the published C2 state. 133 * This seems to be a common problem on AMD boxen, but other vendors 134 * are affected too. We pick the most conservative approach: we assume 135 * that the local APIC stops in both C2 and C3. 136 */ 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 138 struct acpi_processor_cx *cx) 139 { 140 struct acpi_processor_power *pwr = &pr->power; 141 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 142 143 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 144 return; 145 146 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 147 type = ACPI_STATE_C1; 148 149 /* 150 * Check, if one of the previous states already marked the lapic 151 * unstable 152 */ 153 if (pwr->timer_broadcast_on_state < state) 154 return; 155 156 if (cx->type >= type) 157 pr->power.timer_broadcast_on_state = state; 158 } 159 160 static void __lapic_timer_propagate_broadcast(void *arg) 161 { 162 struct acpi_processor *pr = (struct acpi_processor *) arg; 163 164 if (pr->power.timer_broadcast_on_state < INT_MAX) 165 tick_broadcast_enable(); 166 else 167 tick_broadcast_disable(); 168 } 169 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 171 { 172 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 173 (void *)pr, 1); 174 } 175 176 /* Power(C) State timer broadcast control */ 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 178 struct acpi_processor_cx *cx, 179 int broadcast) 180 { 181 int state = cx - pr->power.states; 182 183 if (state >= pr->power.timer_broadcast_on_state) { 184 if (broadcast) 185 tick_broadcast_enter(); 186 else 187 tick_broadcast_exit(); 188 } 189 } 190 191 #else 192 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 194 struct acpi_processor_cx *cstate) { } 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 197 struct acpi_processor_cx *cx, 198 int broadcast) 199 { 200 } 201 202 #endif 203 204 #if defined(CONFIG_X86) 205 static void tsc_check_state(int state) 206 { 207 switch (boot_cpu_data.x86_vendor) { 208 case X86_VENDOR_AMD: 209 case X86_VENDOR_INTEL: 210 /* 211 * AMD Fam10h TSC will tick in all 212 * C/P/S0/S1 states when this bit is set. 213 */ 214 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 215 return; 216 217 /*FALL THROUGH*/ 218 default: 219 /* TSC could halt in idle, so notify users */ 220 if (state > ACPI_STATE_C1) 221 mark_tsc_unstable("TSC halts in idle"); 222 } 223 } 224 #else 225 static void tsc_check_state(int state) { return; } 226 #endif 227 228 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 229 { 230 231 if (!pr->pblk) 232 return -ENODEV; 233 234 /* if info is obtained from pblk/fadt, type equals state */ 235 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 236 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 237 238 #ifndef CONFIG_HOTPLUG_CPU 239 /* 240 * Check for P_LVL2_UP flag before entering C2 and above on 241 * an SMP system. 242 */ 243 if ((num_online_cpus() > 1) && 244 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 245 return -ENODEV; 246 #endif 247 248 /* determine C2 and C3 address from pblk */ 249 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 250 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 251 252 /* determine latencies from FADT */ 253 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 254 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 255 256 /* 257 * FADT specified C2 latency must be less than or equal to 258 * 100 microseconds. 259 */ 260 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 261 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 262 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 263 /* invalidate C2 */ 264 pr->power.states[ACPI_STATE_C2].address = 0; 265 } 266 267 /* 268 * FADT supplied C3 latency must be less than or equal to 269 * 1000 microseconds. 270 */ 271 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 272 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 273 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 274 /* invalidate C3 */ 275 pr->power.states[ACPI_STATE_C3].address = 0; 276 } 277 278 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 279 "lvl2[0x%08x] lvl3[0x%08x]\n", 280 pr->power.states[ACPI_STATE_C2].address, 281 pr->power.states[ACPI_STATE_C3].address)); 282 283 return 0; 284 } 285 286 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 287 { 288 if (!pr->power.states[ACPI_STATE_C1].valid) { 289 /* set the first C-State to C1 */ 290 /* all processors need to support C1 */ 291 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 292 pr->power.states[ACPI_STATE_C1].valid = 1; 293 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 294 } 295 /* the C0 state only exists as a filler in our array */ 296 pr->power.states[ACPI_STATE_C0].valid = 1; 297 return 0; 298 } 299 300 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 301 { 302 acpi_status status; 303 u64 count; 304 int current_count; 305 int i, ret = 0; 306 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 307 union acpi_object *cst; 308 309 if (nocst) 310 return -ENODEV; 311 312 current_count = 0; 313 314 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 315 if (ACPI_FAILURE(status)) { 316 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 317 return -ENODEV; 318 } 319 320 cst = buffer.pointer; 321 322 /* There must be at least 2 elements */ 323 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 324 pr_err("not enough elements in _CST\n"); 325 ret = -EFAULT; 326 goto end; 327 } 328 329 count = cst->package.elements[0].integer.value; 330 331 /* Validate number of power states. */ 332 if (count < 1 || count != cst->package.count - 1) { 333 pr_err("count given by _CST is not valid\n"); 334 ret = -EFAULT; 335 goto end; 336 } 337 338 /* Tell driver that at least _CST is supported. */ 339 pr->flags.has_cst = 1; 340 341 for (i = 1; i <= count; i++) { 342 union acpi_object *element; 343 union acpi_object *obj; 344 struct acpi_power_register *reg; 345 struct acpi_processor_cx cx; 346 347 memset(&cx, 0, sizeof(cx)); 348 349 element = &(cst->package.elements[i]); 350 if (element->type != ACPI_TYPE_PACKAGE) 351 continue; 352 353 if (element->package.count != 4) 354 continue; 355 356 obj = &(element->package.elements[0]); 357 358 if (obj->type != ACPI_TYPE_BUFFER) 359 continue; 360 361 reg = (struct acpi_power_register *)obj->buffer.pointer; 362 363 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 364 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 365 continue; 366 367 /* There should be an easy way to extract an integer... */ 368 obj = &(element->package.elements[1]); 369 if (obj->type != ACPI_TYPE_INTEGER) 370 continue; 371 372 cx.type = obj->integer.value; 373 /* 374 * Some buggy BIOSes won't list C1 in _CST - 375 * Let acpi_processor_get_power_info_default() handle them later 376 */ 377 if (i == 1 && cx.type != ACPI_STATE_C1) 378 current_count++; 379 380 cx.address = reg->address; 381 cx.index = current_count + 1; 382 383 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 384 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 385 if (acpi_processor_ffh_cstate_probe 386 (pr->id, &cx, reg) == 0) { 387 cx.entry_method = ACPI_CSTATE_FFH; 388 } else if (cx.type == ACPI_STATE_C1) { 389 /* 390 * C1 is a special case where FIXED_HARDWARE 391 * can be handled in non-MWAIT way as well. 392 * In that case, save this _CST entry info. 393 * Otherwise, ignore this info and continue. 394 */ 395 cx.entry_method = ACPI_CSTATE_HALT; 396 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 397 } else { 398 continue; 399 } 400 if (cx.type == ACPI_STATE_C1 && 401 (boot_option_idle_override == IDLE_NOMWAIT)) { 402 /* 403 * In most cases the C1 space_id obtained from 404 * _CST object is FIXED_HARDWARE access mode. 405 * But when the option of idle=halt is added, 406 * the entry_method type should be changed from 407 * CSTATE_FFH to CSTATE_HALT. 408 * When the option of idle=nomwait is added, 409 * the C1 entry_method type should be 410 * CSTATE_HALT. 411 */ 412 cx.entry_method = ACPI_CSTATE_HALT; 413 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 414 } 415 } else { 416 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 417 cx.address); 418 } 419 420 if (cx.type == ACPI_STATE_C1) { 421 cx.valid = 1; 422 } 423 424 obj = &(element->package.elements[2]); 425 if (obj->type != ACPI_TYPE_INTEGER) 426 continue; 427 428 cx.latency = obj->integer.value; 429 430 obj = &(element->package.elements[3]); 431 if (obj->type != ACPI_TYPE_INTEGER) 432 continue; 433 434 current_count++; 435 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 436 437 /* 438 * We support total ACPI_PROCESSOR_MAX_POWER - 1 439 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 440 */ 441 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 442 pr_warn("Limiting number of power states to max (%d)\n", 443 ACPI_PROCESSOR_MAX_POWER); 444 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 445 break; 446 } 447 } 448 449 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 450 current_count)); 451 452 /* Validate number of power states discovered */ 453 if (current_count < 2) 454 ret = -EFAULT; 455 456 end: 457 kfree(buffer.pointer); 458 459 return ret; 460 } 461 462 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 463 struct acpi_processor_cx *cx) 464 { 465 static int bm_check_flag = -1; 466 static int bm_control_flag = -1; 467 468 469 if (!cx->address) 470 return; 471 472 /* 473 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 474 * DMA transfers are used by any ISA device to avoid livelock. 475 * Note that we could disable Type-F DMA (as recommended by 476 * the erratum), but this is known to disrupt certain ISA 477 * devices thus we take the conservative approach. 478 */ 479 else if (errata.piix4.fdma) { 480 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 481 "C3 not supported on PIIX4 with Type-F DMA\n")); 482 return; 483 } 484 485 /* All the logic here assumes flags.bm_check is same across all CPUs */ 486 if (bm_check_flag == -1) { 487 /* Determine whether bm_check is needed based on CPU */ 488 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 489 bm_check_flag = pr->flags.bm_check; 490 bm_control_flag = pr->flags.bm_control; 491 } else { 492 pr->flags.bm_check = bm_check_flag; 493 pr->flags.bm_control = bm_control_flag; 494 } 495 496 if (pr->flags.bm_check) { 497 if (!pr->flags.bm_control) { 498 if (pr->flags.has_cst != 1) { 499 /* bus mastering control is necessary */ 500 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 501 "C3 support requires BM control\n")); 502 return; 503 } else { 504 /* Here we enter C3 without bus mastering */ 505 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 506 "C3 support without BM control\n")); 507 } 508 } 509 } else { 510 /* 511 * WBINVD should be set in fadt, for C3 state to be 512 * supported on when bm_check is not required. 513 */ 514 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 515 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 516 "Cache invalidation should work properly" 517 " for C3 to be enabled on SMP systems\n")); 518 return; 519 } 520 } 521 522 /* 523 * Otherwise we've met all of our C3 requirements. 524 * Normalize the C3 latency to expidite policy. Enable 525 * checking of bus mastering status (bm_check) so we can 526 * use this in our C3 policy 527 */ 528 cx->valid = 1; 529 530 /* 531 * On older chipsets, BM_RLD needs to be set 532 * in order for Bus Master activity to wake the 533 * system from C3. Newer chipsets handle DMA 534 * during C3 automatically and BM_RLD is a NOP. 535 * In either case, the proper way to 536 * handle BM_RLD is to set it and leave it set. 537 */ 538 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 539 540 return; 541 } 542 543 static int acpi_processor_power_verify(struct acpi_processor *pr) 544 { 545 unsigned int i; 546 unsigned int working = 0; 547 548 pr->power.timer_broadcast_on_state = INT_MAX; 549 550 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 551 struct acpi_processor_cx *cx = &pr->power.states[i]; 552 553 switch (cx->type) { 554 case ACPI_STATE_C1: 555 cx->valid = 1; 556 break; 557 558 case ACPI_STATE_C2: 559 if (!cx->address) 560 break; 561 cx->valid = 1; 562 break; 563 564 case ACPI_STATE_C3: 565 acpi_processor_power_verify_c3(pr, cx); 566 break; 567 } 568 if (!cx->valid) 569 continue; 570 571 lapic_timer_check_state(i, pr, cx); 572 tsc_check_state(cx->type); 573 working++; 574 } 575 576 lapic_timer_propagate_broadcast(pr); 577 578 return (working); 579 } 580 581 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 582 { 583 unsigned int i; 584 int result; 585 586 587 /* NOTE: the idle thread may not be running while calling 588 * this function */ 589 590 /* Zero initialize all the C-states info. */ 591 memset(pr->power.states, 0, sizeof(pr->power.states)); 592 593 result = acpi_processor_get_power_info_cst(pr); 594 if (result == -ENODEV) 595 result = acpi_processor_get_power_info_fadt(pr); 596 597 if (result) 598 return result; 599 600 acpi_processor_get_power_info_default(pr); 601 602 pr->power.count = acpi_processor_power_verify(pr); 603 604 /* 605 * if one state of type C2 or C3 is available, mark this 606 * CPU as being "idle manageable" 607 */ 608 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 609 if (pr->power.states[i].valid) { 610 pr->power.count = i; 611 if (pr->power.states[i].type >= ACPI_STATE_C2) 612 pr->flags.power = 1; 613 } 614 } 615 616 return 0; 617 } 618 619 /** 620 * acpi_idle_bm_check - checks if bus master activity was detected 621 */ 622 static int acpi_idle_bm_check(void) 623 { 624 u32 bm_status = 0; 625 626 if (bm_check_disable) 627 return 0; 628 629 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 630 if (bm_status) 631 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 632 /* 633 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 634 * the true state of bus mastering activity; forcing us to 635 * manually check the BMIDEA bit of each IDE channel. 636 */ 637 else if (errata.piix4.bmisx) { 638 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 639 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 640 bm_status = 1; 641 } 642 return bm_status; 643 } 644 645 /** 646 * acpi_idle_do_entry - enter idle state using the appropriate method 647 * @cx: cstate data 648 * 649 * Caller disables interrupt before call and enables interrupt after return. 650 */ 651 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 652 { 653 if (cx->entry_method == ACPI_CSTATE_FFH) { 654 /* Call into architectural FFH based C-state */ 655 acpi_processor_ffh_cstate_enter(cx); 656 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 657 acpi_safe_halt(); 658 } else { 659 /* IO port based C-state */ 660 inb(cx->address); 661 /* Dummy wait op - must do something useless after P_LVL2 read 662 because chipsets cannot guarantee that STPCLK# signal 663 gets asserted in time to freeze execution properly. */ 664 inl(acpi_gbl_FADT.xpm_timer_block.address); 665 } 666 } 667 668 /** 669 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 670 * @dev: the target CPU 671 * @index: the index of suggested state 672 */ 673 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 674 { 675 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 676 677 ACPI_FLUSH_CPU_CACHE(); 678 679 while (1) { 680 681 if (cx->entry_method == ACPI_CSTATE_HALT) 682 safe_halt(); 683 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 684 inb(cx->address); 685 /* See comment in acpi_idle_do_entry() */ 686 inl(acpi_gbl_FADT.xpm_timer_block.address); 687 } else 688 return -ENODEV; 689 } 690 691 /* Never reached */ 692 return 0; 693 } 694 695 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 696 { 697 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 698 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 699 } 700 701 static int c3_cpu_count; 702 static DEFINE_RAW_SPINLOCK(c3_lock); 703 704 /** 705 * acpi_idle_enter_bm - enters C3 with proper BM handling 706 * @pr: Target processor 707 * @cx: Target state context 708 * @timer_bc: Whether or not to change timer mode to broadcast 709 */ 710 static void acpi_idle_enter_bm(struct acpi_processor *pr, 711 struct acpi_processor_cx *cx, bool timer_bc) 712 { 713 /* 714 * Must be done before busmaster disable as we might need to 715 * access HPET ! 716 */ 717 if (timer_bc) 718 lapic_timer_state_broadcast(pr, cx, 1); 719 720 /* 721 * disable bus master 722 * bm_check implies we need ARB_DIS 723 * bm_control implies whether we can do ARB_DIS 724 * 725 * That leaves a case where bm_check is set and bm_control is 726 * not set. In that case we cannot do much, we enter C3 727 * without doing anything. 728 */ 729 if (pr->flags.bm_control) { 730 raw_spin_lock(&c3_lock); 731 c3_cpu_count++; 732 /* Disable bus master arbitration when all CPUs are in C3 */ 733 if (c3_cpu_count == num_online_cpus()) 734 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 735 raw_spin_unlock(&c3_lock); 736 } 737 738 acpi_idle_do_entry(cx); 739 740 /* Re-enable bus master arbitration */ 741 if (pr->flags.bm_control) { 742 raw_spin_lock(&c3_lock); 743 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 744 c3_cpu_count--; 745 raw_spin_unlock(&c3_lock); 746 } 747 748 if (timer_bc) 749 lapic_timer_state_broadcast(pr, cx, 0); 750 } 751 752 static int acpi_idle_enter(struct cpuidle_device *dev, 753 struct cpuidle_driver *drv, int index) 754 { 755 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 756 struct acpi_processor *pr; 757 758 pr = __this_cpu_read(processors); 759 if (unlikely(!pr)) 760 return -EINVAL; 761 762 if (cx->type != ACPI_STATE_C1) { 763 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 764 index = ACPI_IDLE_STATE_START; 765 cx = per_cpu(acpi_cstate[index], dev->cpu); 766 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 767 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 768 acpi_idle_enter_bm(pr, cx, true); 769 return index; 770 } else if (drv->safe_state_index >= 0) { 771 index = drv->safe_state_index; 772 cx = per_cpu(acpi_cstate[index], dev->cpu); 773 } else { 774 acpi_safe_halt(); 775 return -EBUSY; 776 } 777 } 778 } 779 780 lapic_timer_state_broadcast(pr, cx, 1); 781 782 if (cx->type == ACPI_STATE_C3) 783 ACPI_FLUSH_CPU_CACHE(); 784 785 acpi_idle_do_entry(cx); 786 787 lapic_timer_state_broadcast(pr, cx, 0); 788 789 return index; 790 } 791 792 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, 793 struct cpuidle_driver *drv, int index) 794 { 795 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 796 797 if (cx->type == ACPI_STATE_C3) { 798 struct acpi_processor *pr = __this_cpu_read(processors); 799 800 if (unlikely(!pr)) 801 return; 802 803 if (pr->flags.bm_check) { 804 acpi_idle_enter_bm(pr, cx, false); 805 return; 806 } else { 807 ACPI_FLUSH_CPU_CACHE(); 808 } 809 } 810 acpi_idle_do_entry(cx); 811 } 812 813 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 814 struct cpuidle_device *dev) 815 { 816 int i, count = ACPI_IDLE_STATE_START; 817 struct acpi_processor_cx *cx; 818 819 if (max_cstate == 0) 820 max_cstate = 1; 821 822 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 823 cx = &pr->power.states[i]; 824 825 if (!cx->valid) 826 continue; 827 828 per_cpu(acpi_cstate[count], dev->cpu) = cx; 829 830 count++; 831 if (count == CPUIDLE_STATE_MAX) 832 break; 833 } 834 835 if (!count) 836 return -EINVAL; 837 838 return 0; 839 } 840 841 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 842 { 843 int i, count; 844 struct acpi_processor_cx *cx; 845 struct cpuidle_state *state; 846 struct cpuidle_driver *drv = &acpi_idle_driver; 847 848 if (max_cstate == 0) 849 max_cstate = 1; 850 851 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 852 cpuidle_poll_state_init(drv); 853 count = 1; 854 } else { 855 count = 0; 856 } 857 858 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 859 cx = &pr->power.states[i]; 860 861 if (!cx->valid) 862 continue; 863 864 state = &drv->states[count]; 865 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 866 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 867 state->exit_latency = cx->latency; 868 state->target_residency = cx->latency * latency_factor; 869 state->enter = acpi_idle_enter; 870 871 state->flags = 0; 872 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 873 state->enter_dead = acpi_idle_play_dead; 874 drv->safe_state_index = count; 875 } 876 /* 877 * Halt-induced C1 is not good for ->enter_s2idle, because it 878 * re-enables interrupts on exit. Moreover, C1 is generally not 879 * particularly interesting from the suspend-to-idle angle, so 880 * avoid C1 and the situations in which we may need to fall back 881 * to it altogether. 882 */ 883 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 884 state->enter_s2idle = acpi_idle_enter_s2idle; 885 886 count++; 887 if (count == CPUIDLE_STATE_MAX) 888 break; 889 } 890 891 drv->state_count = count; 892 893 if (!count) 894 return -EINVAL; 895 896 return 0; 897 } 898 899 static inline void acpi_processor_cstate_first_run_checks(void) 900 { 901 acpi_status status; 902 static int first_run; 903 904 if (first_run) 905 return; 906 dmi_check_system(processor_power_dmi_table); 907 max_cstate = acpi_processor_cstate_check(max_cstate); 908 if (max_cstate < ACPI_C_STATES_MAX) 909 pr_notice("ACPI: processor limited to max C-state %d\n", 910 max_cstate); 911 first_run++; 912 913 if (acpi_gbl_FADT.cst_control && !nocst) { 914 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 915 acpi_gbl_FADT.cst_control, 8); 916 if (ACPI_FAILURE(status)) 917 ACPI_EXCEPTION((AE_INFO, status, 918 "Notifying BIOS of _CST ability failed")); 919 } 920 } 921 #else 922 923 static inline int disabled_by_idle_boot_param(void) { return 0; } 924 static inline void acpi_processor_cstate_first_run_checks(void) { } 925 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 926 { 927 return -ENODEV; 928 } 929 930 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 931 struct cpuidle_device *dev) 932 { 933 return -EINVAL; 934 } 935 936 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 937 { 938 return -EINVAL; 939 } 940 941 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 942 943 struct acpi_lpi_states_array { 944 unsigned int size; 945 unsigned int composite_states_size; 946 struct acpi_lpi_state *entries; 947 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 948 }; 949 950 static int obj_get_integer(union acpi_object *obj, u32 *value) 951 { 952 if (obj->type != ACPI_TYPE_INTEGER) 953 return -EINVAL; 954 955 *value = obj->integer.value; 956 return 0; 957 } 958 959 static int acpi_processor_evaluate_lpi(acpi_handle handle, 960 struct acpi_lpi_states_array *info) 961 { 962 acpi_status status; 963 int ret = 0; 964 int pkg_count, state_idx = 1, loop; 965 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 966 union acpi_object *lpi_data; 967 struct acpi_lpi_state *lpi_state; 968 969 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 970 if (ACPI_FAILURE(status)) { 971 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 972 return -ENODEV; 973 } 974 975 lpi_data = buffer.pointer; 976 977 /* There must be at least 4 elements = 3 elements + 1 package */ 978 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 979 lpi_data->package.count < 4) { 980 pr_debug("not enough elements in _LPI\n"); 981 ret = -ENODATA; 982 goto end; 983 } 984 985 pkg_count = lpi_data->package.elements[2].integer.value; 986 987 /* Validate number of power states. */ 988 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 989 pr_debug("count given by _LPI is not valid\n"); 990 ret = -ENODATA; 991 goto end; 992 } 993 994 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 995 if (!lpi_state) { 996 ret = -ENOMEM; 997 goto end; 998 } 999 1000 info->size = pkg_count; 1001 info->entries = lpi_state; 1002 1003 /* LPI States start at index 3 */ 1004 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 1005 union acpi_object *element, *pkg_elem, *obj; 1006 1007 element = &lpi_data->package.elements[loop]; 1008 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1009 continue; 1010 1011 pkg_elem = element->package.elements; 1012 1013 obj = pkg_elem + 6; 1014 if (obj->type == ACPI_TYPE_BUFFER) { 1015 struct acpi_power_register *reg; 1016 1017 reg = (struct acpi_power_register *)obj->buffer.pointer; 1018 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1019 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1020 continue; 1021 1022 lpi_state->address = reg->address; 1023 lpi_state->entry_method = 1024 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1025 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1026 } else if (obj->type == ACPI_TYPE_INTEGER) { 1027 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1028 lpi_state->address = obj->integer.value; 1029 } else { 1030 continue; 1031 } 1032 1033 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1034 1035 obj = pkg_elem + 9; 1036 if (obj->type == ACPI_TYPE_STRING) 1037 strlcpy(lpi_state->desc, obj->string.pointer, 1038 ACPI_CX_DESC_LEN); 1039 1040 lpi_state->index = state_idx; 1041 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1042 pr_debug("No min. residency found, assuming 10 us\n"); 1043 lpi_state->min_residency = 10; 1044 } 1045 1046 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1047 pr_debug("No wakeup residency found, assuming 10 us\n"); 1048 lpi_state->wake_latency = 10; 1049 } 1050 1051 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1052 lpi_state->flags = 0; 1053 1054 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1055 lpi_state->arch_flags = 0; 1056 1057 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1058 lpi_state->res_cnt_freq = 1; 1059 1060 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1061 lpi_state->enable_parent_state = 0; 1062 } 1063 1064 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1065 end: 1066 kfree(buffer.pointer); 1067 return ret; 1068 } 1069 1070 /* 1071 * flat_state_cnt - the number of composite LPI states after the process of flattening 1072 */ 1073 static int flat_state_cnt; 1074 1075 /** 1076 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1077 * 1078 * @local: local LPI state 1079 * @parent: parent LPI state 1080 * @result: composite LPI state 1081 */ 1082 static bool combine_lpi_states(struct acpi_lpi_state *local, 1083 struct acpi_lpi_state *parent, 1084 struct acpi_lpi_state *result) 1085 { 1086 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1087 if (!parent->address) /* 0 means autopromotable */ 1088 return false; 1089 result->address = local->address + parent->address; 1090 } else { 1091 result->address = parent->address; 1092 } 1093 1094 result->min_residency = max(local->min_residency, parent->min_residency); 1095 result->wake_latency = local->wake_latency + parent->wake_latency; 1096 result->enable_parent_state = parent->enable_parent_state; 1097 result->entry_method = local->entry_method; 1098 1099 result->flags = parent->flags; 1100 result->arch_flags = parent->arch_flags; 1101 result->index = parent->index; 1102 1103 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1104 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1105 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1106 return true; 1107 } 1108 1109 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1110 1111 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1112 struct acpi_lpi_state *t) 1113 { 1114 curr_level->composite_states[curr_level->composite_states_size++] = t; 1115 } 1116 1117 static int flatten_lpi_states(struct acpi_processor *pr, 1118 struct acpi_lpi_states_array *curr_level, 1119 struct acpi_lpi_states_array *prev_level) 1120 { 1121 int i, j, state_count = curr_level->size; 1122 struct acpi_lpi_state *p, *t = curr_level->entries; 1123 1124 curr_level->composite_states_size = 0; 1125 for (j = 0; j < state_count; j++, t++) { 1126 struct acpi_lpi_state *flpi; 1127 1128 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1129 continue; 1130 1131 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1132 pr_warn("Limiting number of LPI states to max (%d)\n", 1133 ACPI_PROCESSOR_MAX_POWER); 1134 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1135 break; 1136 } 1137 1138 flpi = &pr->power.lpi_states[flat_state_cnt]; 1139 1140 if (!prev_level) { /* leaf/processor node */ 1141 memcpy(flpi, t, sizeof(*t)); 1142 stash_composite_state(curr_level, flpi); 1143 flat_state_cnt++; 1144 continue; 1145 } 1146 1147 for (i = 0; i < prev_level->composite_states_size; i++) { 1148 p = prev_level->composite_states[i]; 1149 if (t->index <= p->enable_parent_state && 1150 combine_lpi_states(p, t, flpi)) { 1151 stash_composite_state(curr_level, flpi); 1152 flat_state_cnt++; 1153 flpi++; 1154 } 1155 } 1156 } 1157 1158 kfree(curr_level->entries); 1159 return 0; 1160 } 1161 1162 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1163 { 1164 int ret, i; 1165 acpi_status status; 1166 acpi_handle handle = pr->handle, pr_ahandle; 1167 struct acpi_device *d = NULL; 1168 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1169 1170 if (!osc_pc_lpi_support_confirmed) 1171 return -EOPNOTSUPP; 1172 1173 if (!acpi_has_method(handle, "_LPI")) 1174 return -EINVAL; 1175 1176 flat_state_cnt = 0; 1177 prev = &info[0]; 1178 curr = &info[1]; 1179 handle = pr->handle; 1180 ret = acpi_processor_evaluate_lpi(handle, prev); 1181 if (ret) 1182 return ret; 1183 flatten_lpi_states(pr, prev, NULL); 1184 1185 status = acpi_get_parent(handle, &pr_ahandle); 1186 while (ACPI_SUCCESS(status)) { 1187 acpi_bus_get_device(pr_ahandle, &d); 1188 handle = pr_ahandle; 1189 1190 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1191 break; 1192 1193 /* can be optional ? */ 1194 if (!acpi_has_method(handle, "_LPI")) 1195 break; 1196 1197 ret = acpi_processor_evaluate_lpi(handle, curr); 1198 if (ret) 1199 break; 1200 1201 /* flatten all the LPI states in this level of hierarchy */ 1202 flatten_lpi_states(pr, curr, prev); 1203 1204 tmp = prev, prev = curr, curr = tmp; 1205 1206 status = acpi_get_parent(handle, &pr_ahandle); 1207 } 1208 1209 pr->power.count = flat_state_cnt; 1210 /* reset the index after flattening */ 1211 for (i = 0; i < pr->power.count; i++) 1212 pr->power.lpi_states[i].index = i; 1213 1214 /* Tell driver that _LPI is supported. */ 1215 pr->flags.has_lpi = 1; 1216 pr->flags.power = 1; 1217 1218 return 0; 1219 } 1220 1221 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1222 { 1223 return -ENODEV; 1224 } 1225 1226 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1227 { 1228 return -ENODEV; 1229 } 1230 1231 /** 1232 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1233 * @dev: the target CPU 1234 * @drv: cpuidle driver containing cpuidle state info 1235 * @index: index of target state 1236 * 1237 * Return: 0 for success or negative value for error 1238 */ 1239 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1240 struct cpuidle_driver *drv, int index) 1241 { 1242 struct acpi_processor *pr; 1243 struct acpi_lpi_state *lpi; 1244 1245 pr = __this_cpu_read(processors); 1246 1247 if (unlikely(!pr)) 1248 return -EINVAL; 1249 1250 lpi = &pr->power.lpi_states[index]; 1251 if (lpi->entry_method == ACPI_CSTATE_FFH) 1252 return acpi_processor_ffh_lpi_enter(lpi); 1253 1254 return -EINVAL; 1255 } 1256 1257 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1258 { 1259 int i; 1260 struct acpi_lpi_state *lpi; 1261 struct cpuidle_state *state; 1262 struct cpuidle_driver *drv = &acpi_idle_driver; 1263 1264 if (!pr->flags.has_lpi) 1265 return -EOPNOTSUPP; 1266 1267 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1268 lpi = &pr->power.lpi_states[i]; 1269 1270 state = &drv->states[i]; 1271 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1272 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1273 state->exit_latency = lpi->wake_latency; 1274 state->target_residency = lpi->min_residency; 1275 if (lpi->arch_flags) 1276 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1277 state->enter = acpi_idle_lpi_enter; 1278 drv->safe_state_index = i; 1279 } 1280 1281 drv->state_count = i; 1282 1283 return 0; 1284 } 1285 1286 /** 1287 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1288 * global state data i.e. idle routines 1289 * 1290 * @pr: the ACPI processor 1291 */ 1292 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1293 { 1294 int i; 1295 struct cpuidle_driver *drv = &acpi_idle_driver; 1296 1297 if (!pr->flags.power_setup_done || !pr->flags.power) 1298 return -EINVAL; 1299 1300 drv->safe_state_index = -1; 1301 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1302 drv->states[i].name[0] = '\0'; 1303 drv->states[i].desc[0] = '\0'; 1304 } 1305 1306 if (pr->flags.has_lpi) 1307 return acpi_processor_setup_lpi_states(pr); 1308 1309 return acpi_processor_setup_cstates(pr); 1310 } 1311 1312 /** 1313 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1314 * device i.e. per-cpu data 1315 * 1316 * @pr: the ACPI processor 1317 * @dev : the cpuidle device 1318 */ 1319 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1320 struct cpuidle_device *dev) 1321 { 1322 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1323 return -EINVAL; 1324 1325 dev->cpu = pr->id; 1326 if (pr->flags.has_lpi) 1327 return acpi_processor_ffh_lpi_probe(pr->id); 1328 1329 return acpi_processor_setup_cpuidle_cx(pr, dev); 1330 } 1331 1332 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1333 { 1334 int ret; 1335 1336 ret = acpi_processor_get_lpi_info(pr); 1337 if (ret) 1338 ret = acpi_processor_get_cstate_info(pr); 1339 1340 return ret; 1341 } 1342 1343 int acpi_processor_hotplug(struct acpi_processor *pr) 1344 { 1345 int ret = 0; 1346 struct cpuidle_device *dev; 1347 1348 if (disabled_by_idle_boot_param()) 1349 return 0; 1350 1351 if (!pr->flags.power_setup_done) 1352 return -ENODEV; 1353 1354 dev = per_cpu(acpi_cpuidle_device, pr->id); 1355 cpuidle_pause_and_lock(); 1356 cpuidle_disable_device(dev); 1357 ret = acpi_processor_get_power_info(pr); 1358 if (!ret && pr->flags.power) { 1359 acpi_processor_setup_cpuidle_dev(pr, dev); 1360 ret = cpuidle_enable_device(dev); 1361 } 1362 cpuidle_resume_and_unlock(); 1363 1364 return ret; 1365 } 1366 1367 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1368 { 1369 int cpu; 1370 struct acpi_processor *_pr; 1371 struct cpuidle_device *dev; 1372 1373 if (disabled_by_idle_boot_param()) 1374 return 0; 1375 1376 if (!pr->flags.power_setup_done) 1377 return -ENODEV; 1378 1379 /* 1380 * FIXME: Design the ACPI notification to make it once per 1381 * system instead of once per-cpu. This condition is a hack 1382 * to make the code that updates C-States be called once. 1383 */ 1384 1385 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1386 1387 /* Protect against cpu-hotplug */ 1388 get_online_cpus(); 1389 cpuidle_pause_and_lock(); 1390 1391 /* Disable all cpuidle devices */ 1392 for_each_online_cpu(cpu) { 1393 _pr = per_cpu(processors, cpu); 1394 if (!_pr || !_pr->flags.power_setup_done) 1395 continue; 1396 dev = per_cpu(acpi_cpuidle_device, cpu); 1397 cpuidle_disable_device(dev); 1398 } 1399 1400 /* Populate Updated C-state information */ 1401 acpi_processor_get_power_info(pr); 1402 acpi_processor_setup_cpuidle_states(pr); 1403 1404 /* Enable all cpuidle devices */ 1405 for_each_online_cpu(cpu) { 1406 _pr = per_cpu(processors, cpu); 1407 if (!_pr || !_pr->flags.power_setup_done) 1408 continue; 1409 acpi_processor_get_power_info(_pr); 1410 if (_pr->flags.power) { 1411 dev = per_cpu(acpi_cpuidle_device, cpu); 1412 acpi_processor_setup_cpuidle_dev(_pr, dev); 1413 cpuidle_enable_device(dev); 1414 } 1415 } 1416 cpuidle_resume_and_unlock(); 1417 put_online_cpus(); 1418 } 1419 1420 return 0; 1421 } 1422 1423 static int acpi_processor_registered; 1424 1425 int acpi_processor_power_init(struct acpi_processor *pr) 1426 { 1427 int retval; 1428 struct cpuidle_device *dev; 1429 1430 if (disabled_by_idle_boot_param()) 1431 return 0; 1432 1433 acpi_processor_cstate_first_run_checks(); 1434 1435 if (!acpi_processor_get_power_info(pr)) 1436 pr->flags.power_setup_done = 1; 1437 1438 /* 1439 * Install the idle handler if processor power management is supported. 1440 * Note that we use previously set idle handler will be used on 1441 * platforms that only support C1. 1442 */ 1443 if (pr->flags.power) { 1444 /* Register acpi_idle_driver if not already registered */ 1445 if (!acpi_processor_registered) { 1446 acpi_processor_setup_cpuidle_states(pr); 1447 retval = cpuidle_register_driver(&acpi_idle_driver); 1448 if (retval) 1449 return retval; 1450 pr_debug("%s registered with cpuidle\n", 1451 acpi_idle_driver.name); 1452 } 1453 1454 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1455 if (!dev) 1456 return -ENOMEM; 1457 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1458 1459 acpi_processor_setup_cpuidle_dev(pr, dev); 1460 1461 /* Register per-cpu cpuidle_device. Cpuidle driver 1462 * must already be registered before registering device 1463 */ 1464 retval = cpuidle_register_device(dev); 1465 if (retval) { 1466 if (acpi_processor_registered == 0) 1467 cpuidle_unregister_driver(&acpi_idle_driver); 1468 return retval; 1469 } 1470 acpi_processor_registered++; 1471 } 1472 return 0; 1473 } 1474 1475 int acpi_processor_power_exit(struct acpi_processor *pr) 1476 { 1477 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1478 1479 if (disabled_by_idle_boot_param()) 1480 return 0; 1481 1482 if (pr->flags.power) { 1483 cpuidle_unregister_device(dev); 1484 acpi_processor_registered--; 1485 if (acpi_processor_registered == 0) 1486 cpuidle_unregister_driver(&acpi_idle_driver); 1487 } 1488 1489 pr->flags.power_setup_done = 0; 1490 return 0; 1491 } 1492