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_HYGON: 209 case X86_VENDOR_AMD: 210 case X86_VENDOR_INTEL: 211 case X86_VENDOR_CENTAUR: 212 /* 213 * AMD Fam10h TSC will tick in all 214 * C/P/S0/S1 states when this bit is set. 215 */ 216 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 217 return; 218 219 /*FALL THROUGH*/ 220 default: 221 /* TSC could halt in idle, so notify users */ 222 if (state > ACPI_STATE_C1) 223 mark_tsc_unstable("TSC halts in idle"); 224 } 225 } 226 #else 227 static void tsc_check_state(int state) { return; } 228 #endif 229 230 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 231 { 232 233 if (!pr->pblk) 234 return -ENODEV; 235 236 /* if info is obtained from pblk/fadt, type equals state */ 237 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 238 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 239 240 #ifndef CONFIG_HOTPLUG_CPU 241 /* 242 * Check for P_LVL2_UP flag before entering C2 and above on 243 * an SMP system. 244 */ 245 if ((num_online_cpus() > 1) && 246 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 247 return -ENODEV; 248 #endif 249 250 /* determine C2 and C3 address from pblk */ 251 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 252 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 253 254 /* determine latencies from FADT */ 255 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 256 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 257 258 /* 259 * FADT specified C2 latency must be less than or equal to 260 * 100 microseconds. 261 */ 262 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 263 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 264 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 265 /* invalidate C2 */ 266 pr->power.states[ACPI_STATE_C2].address = 0; 267 } 268 269 /* 270 * FADT supplied C3 latency must be less than or equal to 271 * 1000 microseconds. 272 */ 273 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 274 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 275 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 276 /* invalidate C3 */ 277 pr->power.states[ACPI_STATE_C3].address = 0; 278 } 279 280 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 281 "lvl2[0x%08x] lvl3[0x%08x]\n", 282 pr->power.states[ACPI_STATE_C2].address, 283 pr->power.states[ACPI_STATE_C3].address)); 284 285 return 0; 286 } 287 288 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 289 { 290 if (!pr->power.states[ACPI_STATE_C1].valid) { 291 /* set the first C-State to C1 */ 292 /* all processors need to support C1 */ 293 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 294 pr->power.states[ACPI_STATE_C1].valid = 1; 295 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 296 297 snprintf(pr->power.states[ACPI_STATE_C1].desc, 298 ACPI_CX_DESC_LEN, "ACPI HLT"); 299 } 300 /* the C0 state only exists as a filler in our array */ 301 pr->power.states[ACPI_STATE_C0].valid = 1; 302 return 0; 303 } 304 305 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 306 { 307 acpi_status status; 308 u64 count; 309 int current_count; 310 int i, ret = 0; 311 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 312 union acpi_object *cst; 313 314 if (nocst) 315 return -ENODEV; 316 317 current_count = 0; 318 319 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 320 if (ACPI_FAILURE(status)) { 321 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 322 return -ENODEV; 323 } 324 325 cst = buffer.pointer; 326 327 /* There must be at least 2 elements */ 328 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 329 pr_err("not enough elements in _CST\n"); 330 ret = -EFAULT; 331 goto end; 332 } 333 334 count = cst->package.elements[0].integer.value; 335 336 /* Validate number of power states. */ 337 if (count < 1 || count != cst->package.count - 1) { 338 pr_err("count given by _CST is not valid\n"); 339 ret = -EFAULT; 340 goto end; 341 } 342 343 /* Tell driver that at least _CST is supported. */ 344 pr->flags.has_cst = 1; 345 346 for (i = 1; i <= count; i++) { 347 union acpi_object *element; 348 union acpi_object *obj; 349 struct acpi_power_register *reg; 350 struct acpi_processor_cx cx; 351 352 memset(&cx, 0, sizeof(cx)); 353 354 element = &(cst->package.elements[i]); 355 if (element->type != ACPI_TYPE_PACKAGE) 356 continue; 357 358 if (element->package.count != 4) 359 continue; 360 361 obj = &(element->package.elements[0]); 362 363 if (obj->type != ACPI_TYPE_BUFFER) 364 continue; 365 366 reg = (struct acpi_power_register *)obj->buffer.pointer; 367 368 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 369 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 370 continue; 371 372 /* There should be an easy way to extract an integer... */ 373 obj = &(element->package.elements[1]); 374 if (obj->type != ACPI_TYPE_INTEGER) 375 continue; 376 377 cx.type = obj->integer.value; 378 /* 379 * Some buggy BIOSes won't list C1 in _CST - 380 * Let acpi_processor_get_power_info_default() handle them later 381 */ 382 if (i == 1 && cx.type != ACPI_STATE_C1) 383 current_count++; 384 385 cx.address = reg->address; 386 cx.index = current_count + 1; 387 388 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 389 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 390 if (acpi_processor_ffh_cstate_probe 391 (pr->id, &cx, reg) == 0) { 392 cx.entry_method = ACPI_CSTATE_FFH; 393 } else if (cx.type == ACPI_STATE_C1) { 394 /* 395 * C1 is a special case where FIXED_HARDWARE 396 * can be handled in non-MWAIT way as well. 397 * In that case, save this _CST entry info. 398 * Otherwise, ignore this info and continue. 399 */ 400 cx.entry_method = ACPI_CSTATE_HALT; 401 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 402 } else { 403 continue; 404 } 405 if (cx.type == ACPI_STATE_C1 && 406 (boot_option_idle_override == IDLE_NOMWAIT)) { 407 /* 408 * In most cases the C1 space_id obtained from 409 * _CST object is FIXED_HARDWARE access mode. 410 * But when the option of idle=halt is added, 411 * the entry_method type should be changed from 412 * CSTATE_FFH to CSTATE_HALT. 413 * When the option of idle=nomwait is added, 414 * the C1 entry_method type should be 415 * CSTATE_HALT. 416 */ 417 cx.entry_method = ACPI_CSTATE_HALT; 418 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 419 } 420 } else { 421 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 422 cx.address); 423 } 424 425 if (cx.type == ACPI_STATE_C1) { 426 cx.valid = 1; 427 } 428 429 obj = &(element->package.elements[2]); 430 if (obj->type != ACPI_TYPE_INTEGER) 431 continue; 432 433 cx.latency = obj->integer.value; 434 435 obj = &(element->package.elements[3]); 436 if (obj->type != ACPI_TYPE_INTEGER) 437 continue; 438 439 current_count++; 440 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 441 442 /* 443 * We support total ACPI_PROCESSOR_MAX_POWER - 1 444 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 445 */ 446 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 447 pr_warn("Limiting number of power states to max (%d)\n", 448 ACPI_PROCESSOR_MAX_POWER); 449 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 450 break; 451 } 452 } 453 454 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 455 current_count)); 456 457 /* Validate number of power states discovered */ 458 if (current_count < 2) 459 ret = -EFAULT; 460 461 end: 462 kfree(buffer.pointer); 463 464 return ret; 465 } 466 467 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 468 struct acpi_processor_cx *cx) 469 { 470 static int bm_check_flag = -1; 471 static int bm_control_flag = -1; 472 473 474 if (!cx->address) 475 return; 476 477 /* 478 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 479 * DMA transfers are used by any ISA device to avoid livelock. 480 * Note that we could disable Type-F DMA (as recommended by 481 * the erratum), but this is known to disrupt certain ISA 482 * devices thus we take the conservative approach. 483 */ 484 else if (errata.piix4.fdma) { 485 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 486 "C3 not supported on PIIX4 with Type-F DMA\n")); 487 return; 488 } 489 490 /* All the logic here assumes flags.bm_check is same across all CPUs */ 491 if (bm_check_flag == -1) { 492 /* Determine whether bm_check is needed based on CPU */ 493 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 494 bm_check_flag = pr->flags.bm_check; 495 bm_control_flag = pr->flags.bm_control; 496 } else { 497 pr->flags.bm_check = bm_check_flag; 498 pr->flags.bm_control = bm_control_flag; 499 } 500 501 if (pr->flags.bm_check) { 502 if (!pr->flags.bm_control) { 503 if (pr->flags.has_cst != 1) { 504 /* bus mastering control is necessary */ 505 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 506 "C3 support requires BM control\n")); 507 return; 508 } else { 509 /* Here we enter C3 without bus mastering */ 510 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 511 "C3 support without BM control\n")); 512 } 513 } 514 } else { 515 /* 516 * WBINVD should be set in fadt, for C3 state to be 517 * supported on when bm_check is not required. 518 */ 519 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 520 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 521 "Cache invalidation should work properly" 522 " for C3 to be enabled on SMP systems\n")); 523 return; 524 } 525 } 526 527 /* 528 * Otherwise we've met all of our C3 requirements. 529 * Normalize the C3 latency to expidite policy. Enable 530 * checking of bus mastering status (bm_check) so we can 531 * use this in our C3 policy 532 */ 533 cx->valid = 1; 534 535 /* 536 * On older chipsets, BM_RLD needs to be set 537 * in order for Bus Master activity to wake the 538 * system from C3. Newer chipsets handle DMA 539 * during C3 automatically and BM_RLD is a NOP. 540 * In either case, the proper way to 541 * handle BM_RLD is to set it and leave it set. 542 */ 543 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 544 545 return; 546 } 547 548 static int acpi_processor_power_verify(struct acpi_processor *pr) 549 { 550 unsigned int i; 551 unsigned int working = 0; 552 553 pr->power.timer_broadcast_on_state = INT_MAX; 554 555 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 556 struct acpi_processor_cx *cx = &pr->power.states[i]; 557 558 switch (cx->type) { 559 case ACPI_STATE_C1: 560 cx->valid = 1; 561 break; 562 563 case ACPI_STATE_C2: 564 if (!cx->address) 565 break; 566 cx->valid = 1; 567 break; 568 569 case ACPI_STATE_C3: 570 acpi_processor_power_verify_c3(pr, cx); 571 break; 572 } 573 if (!cx->valid) 574 continue; 575 576 lapic_timer_check_state(i, pr, cx); 577 tsc_check_state(cx->type); 578 working++; 579 } 580 581 lapic_timer_propagate_broadcast(pr); 582 583 return (working); 584 } 585 586 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 587 { 588 unsigned int i; 589 int result; 590 591 592 /* NOTE: the idle thread may not be running while calling 593 * this function */ 594 595 /* Zero initialize all the C-states info. */ 596 memset(pr->power.states, 0, sizeof(pr->power.states)); 597 598 result = acpi_processor_get_power_info_cst(pr); 599 if (result == -ENODEV) 600 result = acpi_processor_get_power_info_fadt(pr); 601 602 if (result) 603 return result; 604 605 acpi_processor_get_power_info_default(pr); 606 607 pr->power.count = acpi_processor_power_verify(pr); 608 609 /* 610 * if one state of type C2 or C3 is available, mark this 611 * CPU as being "idle manageable" 612 */ 613 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 614 if (pr->power.states[i].valid) { 615 pr->power.count = i; 616 if (pr->power.states[i].type >= ACPI_STATE_C2) 617 pr->flags.power = 1; 618 } 619 } 620 621 return 0; 622 } 623 624 /** 625 * acpi_idle_bm_check - checks if bus master activity was detected 626 */ 627 static int acpi_idle_bm_check(void) 628 { 629 u32 bm_status = 0; 630 631 if (bm_check_disable) 632 return 0; 633 634 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 635 if (bm_status) 636 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 637 /* 638 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 639 * the true state of bus mastering activity; forcing us to 640 * manually check the BMIDEA bit of each IDE channel. 641 */ 642 else if (errata.piix4.bmisx) { 643 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 644 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 645 bm_status = 1; 646 } 647 return bm_status; 648 } 649 650 /** 651 * acpi_idle_do_entry - enter idle state using the appropriate method 652 * @cx: cstate data 653 * 654 * Caller disables interrupt before call and enables interrupt after return. 655 */ 656 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 657 { 658 if (cx->entry_method == ACPI_CSTATE_FFH) { 659 /* Call into architectural FFH based C-state */ 660 acpi_processor_ffh_cstate_enter(cx); 661 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 662 acpi_safe_halt(); 663 } else { 664 /* IO port based C-state */ 665 inb(cx->address); 666 /* Dummy wait op - must do something useless after P_LVL2 read 667 because chipsets cannot guarantee that STPCLK# signal 668 gets asserted in time to freeze execution properly. */ 669 inl(acpi_gbl_FADT.xpm_timer_block.address); 670 } 671 } 672 673 /** 674 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 675 * @dev: the target CPU 676 * @index: the index of suggested state 677 */ 678 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 679 { 680 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 681 682 ACPI_FLUSH_CPU_CACHE(); 683 684 while (1) { 685 686 if (cx->entry_method == ACPI_CSTATE_HALT) 687 safe_halt(); 688 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 689 inb(cx->address); 690 /* See comment in acpi_idle_do_entry() */ 691 inl(acpi_gbl_FADT.xpm_timer_block.address); 692 } else 693 return -ENODEV; 694 } 695 696 /* Never reached */ 697 return 0; 698 } 699 700 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 701 { 702 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 703 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 704 } 705 706 static int c3_cpu_count; 707 static DEFINE_RAW_SPINLOCK(c3_lock); 708 709 /** 710 * acpi_idle_enter_bm - enters C3 with proper BM handling 711 * @pr: Target processor 712 * @cx: Target state context 713 * @timer_bc: Whether or not to change timer mode to broadcast 714 */ 715 static void acpi_idle_enter_bm(struct acpi_processor *pr, 716 struct acpi_processor_cx *cx, bool timer_bc) 717 { 718 acpi_unlazy_tlb(smp_processor_id()); 719 720 /* 721 * Must be done before busmaster disable as we might need to 722 * access HPET ! 723 */ 724 if (timer_bc) 725 lapic_timer_state_broadcast(pr, cx, 1); 726 727 /* 728 * disable bus master 729 * bm_check implies we need ARB_DIS 730 * bm_control implies whether we can do ARB_DIS 731 * 732 * That leaves a case where bm_check is set and bm_control is 733 * not set. In that case we cannot do much, we enter C3 734 * without doing anything. 735 */ 736 if (pr->flags.bm_control) { 737 raw_spin_lock(&c3_lock); 738 c3_cpu_count++; 739 /* Disable bus master arbitration when all CPUs are in C3 */ 740 if (c3_cpu_count == num_online_cpus()) 741 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 742 raw_spin_unlock(&c3_lock); 743 } 744 745 acpi_idle_do_entry(cx); 746 747 /* Re-enable bus master arbitration */ 748 if (pr->flags.bm_control) { 749 raw_spin_lock(&c3_lock); 750 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 751 c3_cpu_count--; 752 raw_spin_unlock(&c3_lock); 753 } 754 755 if (timer_bc) 756 lapic_timer_state_broadcast(pr, cx, 0); 757 } 758 759 static int acpi_idle_enter(struct cpuidle_device *dev, 760 struct cpuidle_driver *drv, int index) 761 { 762 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 763 struct acpi_processor *pr; 764 765 pr = __this_cpu_read(processors); 766 if (unlikely(!pr)) 767 return -EINVAL; 768 769 if (cx->type != ACPI_STATE_C1) { 770 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 771 index = ACPI_IDLE_STATE_START; 772 cx = per_cpu(acpi_cstate[index], dev->cpu); 773 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 774 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 775 acpi_idle_enter_bm(pr, cx, true); 776 return index; 777 } else if (drv->safe_state_index >= 0) { 778 index = drv->safe_state_index; 779 cx = per_cpu(acpi_cstate[index], dev->cpu); 780 } else { 781 acpi_safe_halt(); 782 return -EBUSY; 783 } 784 } 785 } 786 787 lapic_timer_state_broadcast(pr, cx, 1); 788 789 if (cx->type == ACPI_STATE_C3) 790 ACPI_FLUSH_CPU_CACHE(); 791 792 acpi_idle_do_entry(cx); 793 794 lapic_timer_state_broadcast(pr, cx, 0); 795 796 return index; 797 } 798 799 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, 800 struct cpuidle_driver *drv, int index) 801 { 802 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 803 804 if (cx->type == ACPI_STATE_C3) { 805 struct acpi_processor *pr = __this_cpu_read(processors); 806 807 if (unlikely(!pr)) 808 return; 809 810 if (pr->flags.bm_check) { 811 acpi_idle_enter_bm(pr, cx, false); 812 return; 813 } else { 814 ACPI_FLUSH_CPU_CACHE(); 815 } 816 } 817 acpi_idle_do_entry(cx); 818 } 819 820 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 821 struct cpuidle_device *dev) 822 { 823 int i, count = ACPI_IDLE_STATE_START; 824 struct acpi_processor_cx *cx; 825 826 if (max_cstate == 0) 827 max_cstate = 1; 828 829 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 830 cx = &pr->power.states[i]; 831 832 if (!cx->valid) 833 continue; 834 835 per_cpu(acpi_cstate[count], dev->cpu) = cx; 836 837 count++; 838 if (count == CPUIDLE_STATE_MAX) 839 break; 840 } 841 842 if (!count) 843 return -EINVAL; 844 845 return 0; 846 } 847 848 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 849 { 850 int i, count; 851 struct acpi_processor_cx *cx; 852 struct cpuidle_state *state; 853 struct cpuidle_driver *drv = &acpi_idle_driver; 854 855 if (max_cstate == 0) 856 max_cstate = 1; 857 858 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 859 cpuidle_poll_state_init(drv); 860 count = 1; 861 } else { 862 count = 0; 863 } 864 865 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 866 cx = &pr->power.states[i]; 867 868 if (!cx->valid) 869 continue; 870 871 state = &drv->states[count]; 872 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 873 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 874 state->exit_latency = cx->latency; 875 state->target_residency = cx->latency * latency_factor; 876 state->enter = acpi_idle_enter; 877 878 state->flags = 0; 879 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 880 state->enter_dead = acpi_idle_play_dead; 881 drv->safe_state_index = count; 882 } 883 /* 884 * Halt-induced C1 is not good for ->enter_s2idle, because it 885 * re-enables interrupts on exit. Moreover, C1 is generally not 886 * particularly interesting from the suspend-to-idle angle, so 887 * avoid C1 and the situations in which we may need to fall back 888 * to it altogether. 889 */ 890 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 891 state->enter_s2idle = acpi_idle_enter_s2idle; 892 893 count++; 894 if (count == CPUIDLE_STATE_MAX) 895 break; 896 } 897 898 drv->state_count = count; 899 900 if (!count) 901 return -EINVAL; 902 903 return 0; 904 } 905 906 static inline void acpi_processor_cstate_first_run_checks(void) 907 { 908 acpi_status status; 909 static int first_run; 910 911 if (first_run) 912 return; 913 dmi_check_system(processor_power_dmi_table); 914 max_cstate = acpi_processor_cstate_check(max_cstate); 915 if (max_cstate < ACPI_C_STATES_MAX) 916 pr_notice("ACPI: processor limited to max C-state %d\n", 917 max_cstate); 918 first_run++; 919 920 if (acpi_gbl_FADT.cst_control && !nocst) { 921 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 922 acpi_gbl_FADT.cst_control, 8); 923 if (ACPI_FAILURE(status)) 924 ACPI_EXCEPTION((AE_INFO, status, 925 "Notifying BIOS of _CST ability failed")); 926 } 927 } 928 #else 929 930 static inline int disabled_by_idle_boot_param(void) { return 0; } 931 static inline void acpi_processor_cstate_first_run_checks(void) { } 932 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 933 { 934 return -ENODEV; 935 } 936 937 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 938 struct cpuidle_device *dev) 939 { 940 return -EINVAL; 941 } 942 943 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 944 { 945 return -EINVAL; 946 } 947 948 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 949 950 struct acpi_lpi_states_array { 951 unsigned int size; 952 unsigned int composite_states_size; 953 struct acpi_lpi_state *entries; 954 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 955 }; 956 957 static int obj_get_integer(union acpi_object *obj, u32 *value) 958 { 959 if (obj->type != ACPI_TYPE_INTEGER) 960 return -EINVAL; 961 962 *value = obj->integer.value; 963 return 0; 964 } 965 966 static int acpi_processor_evaluate_lpi(acpi_handle handle, 967 struct acpi_lpi_states_array *info) 968 { 969 acpi_status status; 970 int ret = 0; 971 int pkg_count, state_idx = 1, loop; 972 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 973 union acpi_object *lpi_data; 974 struct acpi_lpi_state *lpi_state; 975 976 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 977 if (ACPI_FAILURE(status)) { 978 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 979 return -ENODEV; 980 } 981 982 lpi_data = buffer.pointer; 983 984 /* There must be at least 4 elements = 3 elements + 1 package */ 985 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 986 lpi_data->package.count < 4) { 987 pr_debug("not enough elements in _LPI\n"); 988 ret = -ENODATA; 989 goto end; 990 } 991 992 pkg_count = lpi_data->package.elements[2].integer.value; 993 994 /* Validate number of power states. */ 995 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 996 pr_debug("count given by _LPI is not valid\n"); 997 ret = -ENODATA; 998 goto end; 999 } 1000 1001 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 1002 if (!lpi_state) { 1003 ret = -ENOMEM; 1004 goto end; 1005 } 1006 1007 info->size = pkg_count; 1008 info->entries = lpi_state; 1009 1010 /* LPI States start at index 3 */ 1011 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 1012 union acpi_object *element, *pkg_elem, *obj; 1013 1014 element = &lpi_data->package.elements[loop]; 1015 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1016 continue; 1017 1018 pkg_elem = element->package.elements; 1019 1020 obj = pkg_elem + 6; 1021 if (obj->type == ACPI_TYPE_BUFFER) { 1022 struct acpi_power_register *reg; 1023 1024 reg = (struct acpi_power_register *)obj->buffer.pointer; 1025 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1026 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1027 continue; 1028 1029 lpi_state->address = reg->address; 1030 lpi_state->entry_method = 1031 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1032 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1033 } else if (obj->type == ACPI_TYPE_INTEGER) { 1034 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1035 lpi_state->address = obj->integer.value; 1036 } else { 1037 continue; 1038 } 1039 1040 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1041 1042 obj = pkg_elem + 9; 1043 if (obj->type == ACPI_TYPE_STRING) 1044 strlcpy(lpi_state->desc, obj->string.pointer, 1045 ACPI_CX_DESC_LEN); 1046 1047 lpi_state->index = state_idx; 1048 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1049 pr_debug("No min. residency found, assuming 10 us\n"); 1050 lpi_state->min_residency = 10; 1051 } 1052 1053 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1054 pr_debug("No wakeup residency found, assuming 10 us\n"); 1055 lpi_state->wake_latency = 10; 1056 } 1057 1058 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1059 lpi_state->flags = 0; 1060 1061 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1062 lpi_state->arch_flags = 0; 1063 1064 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1065 lpi_state->res_cnt_freq = 1; 1066 1067 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1068 lpi_state->enable_parent_state = 0; 1069 } 1070 1071 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1072 end: 1073 kfree(buffer.pointer); 1074 return ret; 1075 } 1076 1077 /* 1078 * flat_state_cnt - the number of composite LPI states after the process of flattening 1079 */ 1080 static int flat_state_cnt; 1081 1082 /** 1083 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1084 * 1085 * @local: local LPI state 1086 * @parent: parent LPI state 1087 * @result: composite LPI state 1088 */ 1089 static bool combine_lpi_states(struct acpi_lpi_state *local, 1090 struct acpi_lpi_state *parent, 1091 struct acpi_lpi_state *result) 1092 { 1093 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1094 if (!parent->address) /* 0 means autopromotable */ 1095 return false; 1096 result->address = local->address + parent->address; 1097 } else { 1098 result->address = parent->address; 1099 } 1100 1101 result->min_residency = max(local->min_residency, parent->min_residency); 1102 result->wake_latency = local->wake_latency + parent->wake_latency; 1103 result->enable_parent_state = parent->enable_parent_state; 1104 result->entry_method = local->entry_method; 1105 1106 result->flags = parent->flags; 1107 result->arch_flags = parent->arch_flags; 1108 result->index = parent->index; 1109 1110 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1111 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1112 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1113 return true; 1114 } 1115 1116 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1117 1118 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1119 struct acpi_lpi_state *t) 1120 { 1121 curr_level->composite_states[curr_level->composite_states_size++] = t; 1122 } 1123 1124 static int flatten_lpi_states(struct acpi_processor *pr, 1125 struct acpi_lpi_states_array *curr_level, 1126 struct acpi_lpi_states_array *prev_level) 1127 { 1128 int i, j, state_count = curr_level->size; 1129 struct acpi_lpi_state *p, *t = curr_level->entries; 1130 1131 curr_level->composite_states_size = 0; 1132 for (j = 0; j < state_count; j++, t++) { 1133 struct acpi_lpi_state *flpi; 1134 1135 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1136 continue; 1137 1138 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1139 pr_warn("Limiting number of LPI states to max (%d)\n", 1140 ACPI_PROCESSOR_MAX_POWER); 1141 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1142 break; 1143 } 1144 1145 flpi = &pr->power.lpi_states[flat_state_cnt]; 1146 1147 if (!prev_level) { /* leaf/processor node */ 1148 memcpy(flpi, t, sizeof(*t)); 1149 stash_composite_state(curr_level, flpi); 1150 flat_state_cnt++; 1151 continue; 1152 } 1153 1154 for (i = 0; i < prev_level->composite_states_size; i++) { 1155 p = prev_level->composite_states[i]; 1156 if (t->index <= p->enable_parent_state && 1157 combine_lpi_states(p, t, flpi)) { 1158 stash_composite_state(curr_level, flpi); 1159 flat_state_cnt++; 1160 flpi++; 1161 } 1162 } 1163 } 1164 1165 kfree(curr_level->entries); 1166 return 0; 1167 } 1168 1169 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1170 { 1171 int ret, i; 1172 acpi_status status; 1173 acpi_handle handle = pr->handle, pr_ahandle; 1174 struct acpi_device *d = NULL; 1175 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1176 1177 if (!osc_pc_lpi_support_confirmed) 1178 return -EOPNOTSUPP; 1179 1180 if (!acpi_has_method(handle, "_LPI")) 1181 return -EINVAL; 1182 1183 flat_state_cnt = 0; 1184 prev = &info[0]; 1185 curr = &info[1]; 1186 handle = pr->handle; 1187 ret = acpi_processor_evaluate_lpi(handle, prev); 1188 if (ret) 1189 return ret; 1190 flatten_lpi_states(pr, prev, NULL); 1191 1192 status = acpi_get_parent(handle, &pr_ahandle); 1193 while (ACPI_SUCCESS(status)) { 1194 acpi_bus_get_device(pr_ahandle, &d); 1195 handle = pr_ahandle; 1196 1197 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1198 break; 1199 1200 /* can be optional ? */ 1201 if (!acpi_has_method(handle, "_LPI")) 1202 break; 1203 1204 ret = acpi_processor_evaluate_lpi(handle, curr); 1205 if (ret) 1206 break; 1207 1208 /* flatten all the LPI states in this level of hierarchy */ 1209 flatten_lpi_states(pr, curr, prev); 1210 1211 tmp = prev, prev = curr, curr = tmp; 1212 1213 status = acpi_get_parent(handle, &pr_ahandle); 1214 } 1215 1216 pr->power.count = flat_state_cnt; 1217 /* reset the index after flattening */ 1218 for (i = 0; i < pr->power.count; i++) 1219 pr->power.lpi_states[i].index = i; 1220 1221 /* Tell driver that _LPI is supported. */ 1222 pr->flags.has_lpi = 1; 1223 pr->flags.power = 1; 1224 1225 return 0; 1226 } 1227 1228 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1229 { 1230 return -ENODEV; 1231 } 1232 1233 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1234 { 1235 return -ENODEV; 1236 } 1237 1238 /** 1239 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1240 * @dev: the target CPU 1241 * @drv: cpuidle driver containing cpuidle state info 1242 * @index: index of target state 1243 * 1244 * Return: 0 for success or negative value for error 1245 */ 1246 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1247 struct cpuidle_driver *drv, int index) 1248 { 1249 struct acpi_processor *pr; 1250 struct acpi_lpi_state *lpi; 1251 1252 pr = __this_cpu_read(processors); 1253 1254 if (unlikely(!pr)) 1255 return -EINVAL; 1256 1257 lpi = &pr->power.lpi_states[index]; 1258 if (lpi->entry_method == ACPI_CSTATE_FFH) 1259 return acpi_processor_ffh_lpi_enter(lpi); 1260 1261 return -EINVAL; 1262 } 1263 1264 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1265 { 1266 int i; 1267 struct acpi_lpi_state *lpi; 1268 struct cpuidle_state *state; 1269 struct cpuidle_driver *drv = &acpi_idle_driver; 1270 1271 if (!pr->flags.has_lpi) 1272 return -EOPNOTSUPP; 1273 1274 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1275 lpi = &pr->power.lpi_states[i]; 1276 1277 state = &drv->states[i]; 1278 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1279 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1280 state->exit_latency = lpi->wake_latency; 1281 state->target_residency = lpi->min_residency; 1282 if (lpi->arch_flags) 1283 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1284 state->enter = acpi_idle_lpi_enter; 1285 drv->safe_state_index = i; 1286 } 1287 1288 drv->state_count = i; 1289 1290 return 0; 1291 } 1292 1293 /** 1294 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1295 * global state data i.e. idle routines 1296 * 1297 * @pr: the ACPI processor 1298 */ 1299 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1300 { 1301 int i; 1302 struct cpuidle_driver *drv = &acpi_idle_driver; 1303 1304 if (!pr->flags.power_setup_done || !pr->flags.power) 1305 return -EINVAL; 1306 1307 drv->safe_state_index = -1; 1308 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1309 drv->states[i].name[0] = '\0'; 1310 drv->states[i].desc[0] = '\0'; 1311 } 1312 1313 if (pr->flags.has_lpi) 1314 return acpi_processor_setup_lpi_states(pr); 1315 1316 return acpi_processor_setup_cstates(pr); 1317 } 1318 1319 /** 1320 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1321 * device i.e. per-cpu data 1322 * 1323 * @pr: the ACPI processor 1324 * @dev : the cpuidle device 1325 */ 1326 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1327 struct cpuidle_device *dev) 1328 { 1329 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1330 return -EINVAL; 1331 1332 dev->cpu = pr->id; 1333 if (pr->flags.has_lpi) 1334 return acpi_processor_ffh_lpi_probe(pr->id); 1335 1336 return acpi_processor_setup_cpuidle_cx(pr, dev); 1337 } 1338 1339 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1340 { 1341 int ret; 1342 1343 ret = acpi_processor_get_lpi_info(pr); 1344 if (ret) 1345 ret = acpi_processor_get_cstate_info(pr); 1346 1347 return ret; 1348 } 1349 1350 int acpi_processor_hotplug(struct acpi_processor *pr) 1351 { 1352 int ret = 0; 1353 struct cpuidle_device *dev; 1354 1355 if (disabled_by_idle_boot_param()) 1356 return 0; 1357 1358 if (!pr->flags.power_setup_done) 1359 return -ENODEV; 1360 1361 dev = per_cpu(acpi_cpuidle_device, pr->id); 1362 cpuidle_pause_and_lock(); 1363 cpuidle_disable_device(dev); 1364 ret = acpi_processor_get_power_info(pr); 1365 if (!ret && pr->flags.power) { 1366 acpi_processor_setup_cpuidle_dev(pr, dev); 1367 ret = cpuidle_enable_device(dev); 1368 } 1369 cpuidle_resume_and_unlock(); 1370 1371 return ret; 1372 } 1373 1374 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1375 { 1376 int cpu; 1377 struct acpi_processor *_pr; 1378 struct cpuidle_device *dev; 1379 1380 if (disabled_by_idle_boot_param()) 1381 return 0; 1382 1383 if (!pr->flags.power_setup_done) 1384 return -ENODEV; 1385 1386 /* 1387 * FIXME: Design the ACPI notification to make it once per 1388 * system instead of once per-cpu. This condition is a hack 1389 * to make the code that updates C-States be called once. 1390 */ 1391 1392 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1393 1394 /* Protect against cpu-hotplug */ 1395 get_online_cpus(); 1396 cpuidle_pause_and_lock(); 1397 1398 /* Disable all cpuidle devices */ 1399 for_each_online_cpu(cpu) { 1400 _pr = per_cpu(processors, cpu); 1401 if (!_pr || !_pr->flags.power_setup_done) 1402 continue; 1403 dev = per_cpu(acpi_cpuidle_device, cpu); 1404 cpuidle_disable_device(dev); 1405 } 1406 1407 /* Populate Updated C-state information */ 1408 acpi_processor_get_power_info(pr); 1409 acpi_processor_setup_cpuidle_states(pr); 1410 1411 /* Enable all cpuidle devices */ 1412 for_each_online_cpu(cpu) { 1413 _pr = per_cpu(processors, cpu); 1414 if (!_pr || !_pr->flags.power_setup_done) 1415 continue; 1416 acpi_processor_get_power_info(_pr); 1417 if (_pr->flags.power) { 1418 dev = per_cpu(acpi_cpuidle_device, cpu); 1419 acpi_processor_setup_cpuidle_dev(_pr, dev); 1420 cpuidle_enable_device(dev); 1421 } 1422 } 1423 cpuidle_resume_and_unlock(); 1424 put_online_cpus(); 1425 } 1426 1427 return 0; 1428 } 1429 1430 static int acpi_processor_registered; 1431 1432 int acpi_processor_power_init(struct acpi_processor *pr) 1433 { 1434 int retval; 1435 struct cpuidle_device *dev; 1436 1437 if (disabled_by_idle_boot_param()) 1438 return 0; 1439 1440 acpi_processor_cstate_first_run_checks(); 1441 1442 if (!acpi_processor_get_power_info(pr)) 1443 pr->flags.power_setup_done = 1; 1444 1445 /* 1446 * Install the idle handler if processor power management is supported. 1447 * Note that we use previously set idle handler will be used on 1448 * platforms that only support C1. 1449 */ 1450 if (pr->flags.power) { 1451 /* Register acpi_idle_driver if not already registered */ 1452 if (!acpi_processor_registered) { 1453 acpi_processor_setup_cpuidle_states(pr); 1454 retval = cpuidle_register_driver(&acpi_idle_driver); 1455 if (retval) 1456 return retval; 1457 pr_debug("%s registered with cpuidle\n", 1458 acpi_idle_driver.name); 1459 } 1460 1461 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1462 if (!dev) 1463 return -ENOMEM; 1464 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1465 1466 acpi_processor_setup_cpuidle_dev(pr, dev); 1467 1468 /* Register per-cpu cpuidle_device. Cpuidle driver 1469 * must already be registered before registering device 1470 */ 1471 retval = cpuidle_register_device(dev); 1472 if (retval) { 1473 if (acpi_processor_registered == 0) 1474 cpuidle_unregister_driver(&acpi_idle_driver); 1475 return retval; 1476 } 1477 acpi_processor_registered++; 1478 } 1479 return 0; 1480 } 1481 1482 int acpi_processor_power_exit(struct acpi_processor *pr) 1483 { 1484 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1485 1486 if (disabled_by_idle_boot_param()) 1487 return 0; 1488 1489 if (pr->flags.power) { 1490 cpuidle_unregister_device(dev); 1491 acpi_processor_registered--; 1492 if (acpi_processor_registered == 0) 1493 cpuidle_unregister_driver(&acpi_idle_driver); 1494 } 1495 1496 pr->flags.power_setup_done = 0; 1497 return 0; 1498 } 1499