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