1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * processor_idle - idle state submodule to the ACPI processor driver 4 * 5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de> 8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 9 * - Added processor hotplug support 10 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 11 * - Added support for C3 on SMP 12 */ 13 #define pr_fmt(fmt) "ACPI: " fmt 14 15 #include <linux/module.h> 16 #include <linux/acpi.h> 17 #include <linux/dmi.h> 18 #include <linux/sched.h> /* need_resched() */ 19 #include <linux/tick.h> 20 #include <linux/cpuidle.h> 21 #include <linux/cpu.h> 22 #include <acpi/processor.h> 23 24 /* 25 * Include the apic definitions for x86 to have the APIC timer related defines 26 * available also for UP (on SMP it gets magically included via linux/smp.h). 27 * asm/acpi.h is not an option, as it would require more include magic. Also 28 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 29 */ 30 #ifdef CONFIG_X86 31 #include <asm/apic.h> 32 #endif 33 34 #define ACPI_PROCESSOR_CLASS "processor" 35 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 36 ACPI_MODULE_NAME("processor_idle"); 37 38 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) 39 40 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 41 module_param(max_cstate, uint, 0000); 42 static unsigned int nocst __read_mostly; 43 module_param(nocst, uint, 0000); 44 static int bm_check_disable __read_mostly; 45 module_param(bm_check_disable, uint, 0000); 46 47 static unsigned int latency_factor __read_mostly = 2; 48 module_param(latency_factor, uint, 0644); 49 50 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 51 52 struct cpuidle_driver acpi_idle_driver = { 53 .name = "acpi_idle", 54 .owner = THIS_MODULE, 55 }; 56 57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 58 static 59 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 60 61 static int disabled_by_idle_boot_param(void) 62 { 63 return boot_option_idle_override == IDLE_POLL || 64 boot_option_idle_override == IDLE_HALT; 65 } 66 67 /* 68 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 69 * For now disable this. Probably a bug somewhere else. 70 * 71 * To skip this limit, boot/load with a large max_cstate limit. 72 */ 73 static int set_max_cstate(const struct dmi_system_id *id) 74 { 75 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 76 return 0; 77 78 pr_notice("%s detected - limiting to C%ld max_cstate." 79 " Override with \"processor.max_cstate=%d\"\n", id->ident, 80 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 81 82 max_cstate = (long)id->driver_data; 83 84 return 0; 85 } 86 87 static const struct dmi_system_id processor_power_dmi_table[] = { 88 { set_max_cstate, "Clevo 5600D", { 89 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 90 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 91 (void *)2}, 92 { set_max_cstate, "Pavilion zv5000", { 93 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 94 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 95 (void *)1}, 96 { set_max_cstate, "Asus L8400B", { 97 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 98 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 99 (void *)1}, 100 {}, 101 }; 102 103 104 /* 105 * Callers should disable interrupts before the call and enable 106 * interrupts after return. 107 */ 108 static void __cpuidle acpi_safe_halt(void) 109 { 110 if (!tif_need_resched()) { 111 safe_halt(); 112 local_irq_disable(); 113 } 114 } 115 116 #ifdef ARCH_APICTIMER_STOPS_ON_C3 117 118 /* 119 * Some BIOS implementations switch to C3 in the published C2 state. 120 * This seems to be a common problem on AMD boxen, but other vendors 121 * are affected too. We pick the most conservative approach: we assume 122 * that the local APIC stops in both C2 and C3. 123 */ 124 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 125 struct acpi_processor_cx *cx) 126 { 127 struct acpi_processor_power *pwr = &pr->power; 128 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 129 130 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 131 return; 132 133 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 134 type = ACPI_STATE_C1; 135 136 /* 137 * Check, if one of the previous states already marked the lapic 138 * unstable 139 */ 140 if (pwr->timer_broadcast_on_state < state) 141 return; 142 143 if (cx->type >= type) 144 pr->power.timer_broadcast_on_state = state; 145 } 146 147 static void __lapic_timer_propagate_broadcast(void *arg) 148 { 149 struct acpi_processor *pr = (struct acpi_processor *) arg; 150 151 if (pr->power.timer_broadcast_on_state < INT_MAX) 152 tick_broadcast_enable(); 153 else 154 tick_broadcast_disable(); 155 } 156 157 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 158 { 159 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 160 (void *)pr, 1); 161 } 162 163 /* Power(C) State timer broadcast control */ 164 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 165 struct acpi_processor_cx *cx, 166 int broadcast) 167 { 168 int state = cx - pr->power.states; 169 170 if (state >= pr->power.timer_broadcast_on_state) { 171 if (broadcast) 172 tick_broadcast_enter(); 173 else 174 tick_broadcast_exit(); 175 } 176 } 177 178 #else 179 180 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 181 struct acpi_processor_cx *cstate) { } 182 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 183 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 184 struct acpi_processor_cx *cx, 185 int broadcast) 186 { 187 } 188 189 #endif 190 191 #if defined(CONFIG_X86) 192 static void tsc_check_state(int state) 193 { 194 switch (boot_cpu_data.x86_vendor) { 195 case X86_VENDOR_HYGON: 196 case X86_VENDOR_AMD: 197 case X86_VENDOR_INTEL: 198 case X86_VENDOR_CENTAUR: 199 case X86_VENDOR_ZHAOXIN: 200 /* 201 * AMD Fam10h TSC will tick in all 202 * C/P/S0/S1 states when this bit is set. 203 */ 204 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 205 return; 206 207 /*FALL THROUGH*/ 208 default: 209 /* TSC could halt in idle, so notify users */ 210 if (state > ACPI_STATE_C1) 211 mark_tsc_unstable("TSC halts in idle"); 212 } 213 } 214 #else 215 static void tsc_check_state(int state) { return; } 216 #endif 217 218 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 219 { 220 221 if (!pr->pblk) 222 return -ENODEV; 223 224 /* if info is obtained from pblk/fadt, type equals state */ 225 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 226 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 227 228 #ifndef CONFIG_HOTPLUG_CPU 229 /* 230 * Check for P_LVL2_UP flag before entering C2 and above on 231 * an SMP system. 232 */ 233 if ((num_online_cpus() > 1) && 234 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 235 return -ENODEV; 236 #endif 237 238 /* determine C2 and C3 address from pblk */ 239 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 240 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 241 242 /* determine latencies from FADT */ 243 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 244 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 245 246 /* 247 * FADT specified C2 latency must be less than or equal to 248 * 100 microseconds. 249 */ 250 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 251 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 252 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 253 /* invalidate C2 */ 254 pr->power.states[ACPI_STATE_C2].address = 0; 255 } 256 257 /* 258 * FADT supplied C3 latency must be less than or equal to 259 * 1000 microseconds. 260 */ 261 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 262 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 263 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 264 /* invalidate C3 */ 265 pr->power.states[ACPI_STATE_C3].address = 0; 266 } 267 268 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 269 "lvl2[0x%08x] lvl3[0x%08x]\n", 270 pr->power.states[ACPI_STATE_C2].address, 271 pr->power.states[ACPI_STATE_C3].address)); 272 273 snprintf(pr->power.states[ACPI_STATE_C2].desc, 274 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x", 275 pr->power.states[ACPI_STATE_C2].address); 276 snprintf(pr->power.states[ACPI_STATE_C3].desc, 277 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x", 278 pr->power.states[ACPI_STATE_C3].address); 279 280 return 0; 281 } 282 283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 284 { 285 if (!pr->power.states[ACPI_STATE_C1].valid) { 286 /* set the first C-State to C1 */ 287 /* all processors need to support C1 */ 288 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 289 pr->power.states[ACPI_STATE_C1].valid = 1; 290 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 291 292 snprintf(pr->power.states[ACPI_STATE_C1].desc, 293 ACPI_CX_DESC_LEN, "ACPI HLT"); 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 static void wait_for_freeze(void) 646 { 647 #ifdef CONFIG_X86 648 /* No delay is needed if we are in guest */ 649 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) 650 return; 651 #endif 652 /* Dummy wait op - must do something useless after P_LVL2 read 653 because chipsets cannot guarantee that STPCLK# signal 654 gets asserted in time to freeze execution properly. */ 655 inl(acpi_gbl_FADT.xpm_timer_block.address); 656 } 657 658 /** 659 * acpi_idle_do_entry - enter idle state using the appropriate method 660 * @cx: cstate data 661 * 662 * Caller disables interrupt before call and enables interrupt after return. 663 */ 664 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 665 { 666 if (cx->entry_method == ACPI_CSTATE_FFH) { 667 /* Call into architectural FFH based C-state */ 668 acpi_processor_ffh_cstate_enter(cx); 669 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 670 acpi_safe_halt(); 671 } else { 672 /* IO port based C-state */ 673 inb(cx->address); 674 wait_for_freeze(); 675 } 676 } 677 678 /** 679 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 680 * @dev: the target CPU 681 * @index: the index of suggested state 682 */ 683 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 684 { 685 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 686 687 ACPI_FLUSH_CPU_CACHE(); 688 689 while (1) { 690 691 if (cx->entry_method == ACPI_CSTATE_HALT) 692 safe_halt(); 693 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 694 inb(cx->address); 695 wait_for_freeze(); 696 } else 697 return -ENODEV; 698 } 699 700 /* Never reached */ 701 return 0; 702 } 703 704 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 705 { 706 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 707 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 708 } 709 710 static int c3_cpu_count; 711 static DEFINE_RAW_SPINLOCK(c3_lock); 712 713 /** 714 * acpi_idle_enter_bm - enters C3 with proper BM handling 715 * @pr: Target processor 716 * @cx: Target state context 717 * @timer_bc: Whether or not to change timer mode to broadcast 718 */ 719 static void acpi_idle_enter_bm(struct acpi_processor *pr, 720 struct acpi_processor_cx *cx, bool timer_bc) 721 { 722 acpi_unlazy_tlb(smp_processor_id()); 723 724 /* 725 * Must be done before busmaster disable as we might need to 726 * access HPET ! 727 */ 728 if (timer_bc) 729 lapic_timer_state_broadcast(pr, cx, 1); 730 731 /* 732 * disable bus master 733 * bm_check implies we need ARB_DIS 734 * bm_control implies whether we can do ARB_DIS 735 * 736 * That leaves a case where bm_check is set and bm_control is 737 * not set. In that case we cannot do much, we enter C3 738 * without doing anything. 739 */ 740 if (pr->flags.bm_control) { 741 raw_spin_lock(&c3_lock); 742 c3_cpu_count++; 743 /* Disable bus master arbitration when all CPUs are in C3 */ 744 if (c3_cpu_count == num_online_cpus()) 745 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 746 raw_spin_unlock(&c3_lock); 747 } 748 749 acpi_idle_do_entry(cx); 750 751 /* Re-enable bus master arbitration */ 752 if (pr->flags.bm_control) { 753 raw_spin_lock(&c3_lock); 754 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 755 c3_cpu_count--; 756 raw_spin_unlock(&c3_lock); 757 } 758 759 if (timer_bc) 760 lapic_timer_state_broadcast(pr, cx, 0); 761 } 762 763 static int acpi_idle_enter(struct cpuidle_device *dev, 764 struct cpuidle_driver *drv, int index) 765 { 766 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 767 struct acpi_processor *pr; 768 769 pr = __this_cpu_read(processors); 770 if (unlikely(!pr)) 771 return -EINVAL; 772 773 if (cx->type != ACPI_STATE_C1) { 774 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 775 index = ACPI_IDLE_STATE_START; 776 cx = per_cpu(acpi_cstate[index], dev->cpu); 777 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 778 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 779 acpi_idle_enter_bm(pr, cx, true); 780 return index; 781 } else if (drv->safe_state_index >= 0) { 782 index = drv->safe_state_index; 783 cx = per_cpu(acpi_cstate[index], dev->cpu); 784 } else { 785 acpi_safe_halt(); 786 return -EBUSY; 787 } 788 } 789 } 790 791 lapic_timer_state_broadcast(pr, cx, 1); 792 793 if (cx->type == ACPI_STATE_C3) 794 ACPI_FLUSH_CPU_CACHE(); 795 796 acpi_idle_do_entry(cx); 797 798 lapic_timer_state_broadcast(pr, cx, 0); 799 800 return index; 801 } 802 803 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, 804 struct cpuidle_driver *drv, int index) 805 { 806 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 807 808 if (cx->type == ACPI_STATE_C3) { 809 struct acpi_processor *pr = __this_cpu_read(processors); 810 811 if (unlikely(!pr)) 812 return; 813 814 if (pr->flags.bm_check) { 815 acpi_idle_enter_bm(pr, cx, false); 816 return; 817 } else { 818 ACPI_FLUSH_CPU_CACHE(); 819 } 820 } 821 acpi_idle_do_entry(cx); 822 } 823 824 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 825 struct cpuidle_device *dev) 826 { 827 int i, count = ACPI_IDLE_STATE_START; 828 struct acpi_processor_cx *cx; 829 830 if (max_cstate == 0) 831 max_cstate = 1; 832 833 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 834 cx = &pr->power.states[i]; 835 836 if (!cx->valid) 837 continue; 838 839 per_cpu(acpi_cstate[count], dev->cpu) = cx; 840 841 count++; 842 if (count == CPUIDLE_STATE_MAX) 843 break; 844 } 845 846 if (!count) 847 return -EINVAL; 848 849 return 0; 850 } 851 852 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 853 { 854 int i, count; 855 struct acpi_processor_cx *cx; 856 struct cpuidle_state *state; 857 struct cpuidle_driver *drv = &acpi_idle_driver; 858 859 if (max_cstate == 0) 860 max_cstate = 1; 861 862 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 863 cpuidle_poll_state_init(drv); 864 count = 1; 865 } else { 866 count = 0; 867 } 868 869 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 870 cx = &pr->power.states[i]; 871 872 if (!cx->valid) 873 continue; 874 875 state = &drv->states[count]; 876 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 877 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 878 state->exit_latency = cx->latency; 879 state->target_residency = cx->latency * latency_factor; 880 state->enter = acpi_idle_enter; 881 882 state->flags = 0; 883 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 884 state->enter_dead = acpi_idle_play_dead; 885 drv->safe_state_index = count; 886 } 887 /* 888 * Halt-induced C1 is not good for ->enter_s2idle, because it 889 * re-enables interrupts on exit. Moreover, C1 is generally not 890 * particularly interesting from the suspend-to-idle angle, so 891 * avoid C1 and the situations in which we may need to fall back 892 * to it altogether. 893 */ 894 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 895 state->enter_s2idle = acpi_idle_enter_s2idle; 896 897 count++; 898 if (count == CPUIDLE_STATE_MAX) 899 break; 900 } 901 902 drv->state_count = count; 903 904 if (!count) 905 return -EINVAL; 906 907 return 0; 908 } 909 910 static inline void acpi_processor_cstate_first_run_checks(void) 911 { 912 acpi_status status; 913 static int first_run; 914 915 if (first_run) 916 return; 917 dmi_check_system(processor_power_dmi_table); 918 max_cstate = acpi_processor_cstate_check(max_cstate); 919 if (max_cstate < ACPI_C_STATES_MAX) 920 pr_notice("ACPI: processor limited to max C-state %d\n", 921 max_cstate); 922 first_run++; 923 924 if (acpi_gbl_FADT.cst_control && !nocst) { 925 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 926 acpi_gbl_FADT.cst_control, 8); 927 if (ACPI_FAILURE(status)) 928 ACPI_EXCEPTION((AE_INFO, status, 929 "Notifying BIOS of _CST ability failed")); 930 } 931 } 932 #else 933 934 static inline int disabled_by_idle_boot_param(void) { return 0; } 935 static inline void acpi_processor_cstate_first_run_checks(void) { } 936 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 937 { 938 return -ENODEV; 939 } 940 941 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 942 struct cpuidle_device *dev) 943 { 944 return -EINVAL; 945 } 946 947 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 948 { 949 return -EINVAL; 950 } 951 952 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 953 954 struct acpi_lpi_states_array { 955 unsigned int size; 956 unsigned int composite_states_size; 957 struct acpi_lpi_state *entries; 958 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 959 }; 960 961 static int obj_get_integer(union acpi_object *obj, u32 *value) 962 { 963 if (obj->type != ACPI_TYPE_INTEGER) 964 return -EINVAL; 965 966 *value = obj->integer.value; 967 return 0; 968 } 969 970 static int acpi_processor_evaluate_lpi(acpi_handle handle, 971 struct acpi_lpi_states_array *info) 972 { 973 acpi_status status; 974 int ret = 0; 975 int pkg_count, state_idx = 1, loop; 976 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 977 union acpi_object *lpi_data; 978 struct acpi_lpi_state *lpi_state; 979 980 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 981 if (ACPI_FAILURE(status)) { 982 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 983 return -ENODEV; 984 } 985 986 lpi_data = buffer.pointer; 987 988 /* There must be at least 4 elements = 3 elements + 1 package */ 989 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 990 lpi_data->package.count < 4) { 991 pr_debug("not enough elements in _LPI\n"); 992 ret = -ENODATA; 993 goto end; 994 } 995 996 pkg_count = lpi_data->package.elements[2].integer.value; 997 998 /* Validate number of power states. */ 999 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 1000 pr_debug("count given by _LPI is not valid\n"); 1001 ret = -ENODATA; 1002 goto end; 1003 } 1004 1005 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 1006 if (!lpi_state) { 1007 ret = -ENOMEM; 1008 goto end; 1009 } 1010 1011 info->size = pkg_count; 1012 info->entries = lpi_state; 1013 1014 /* LPI States start at index 3 */ 1015 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 1016 union acpi_object *element, *pkg_elem, *obj; 1017 1018 element = &lpi_data->package.elements[loop]; 1019 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1020 continue; 1021 1022 pkg_elem = element->package.elements; 1023 1024 obj = pkg_elem + 6; 1025 if (obj->type == ACPI_TYPE_BUFFER) { 1026 struct acpi_power_register *reg; 1027 1028 reg = (struct acpi_power_register *)obj->buffer.pointer; 1029 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1030 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1031 continue; 1032 1033 lpi_state->address = reg->address; 1034 lpi_state->entry_method = 1035 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1036 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1037 } else if (obj->type == ACPI_TYPE_INTEGER) { 1038 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1039 lpi_state->address = obj->integer.value; 1040 } else { 1041 continue; 1042 } 1043 1044 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1045 1046 obj = pkg_elem + 9; 1047 if (obj->type == ACPI_TYPE_STRING) 1048 strlcpy(lpi_state->desc, obj->string.pointer, 1049 ACPI_CX_DESC_LEN); 1050 1051 lpi_state->index = state_idx; 1052 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1053 pr_debug("No min. residency found, assuming 10 us\n"); 1054 lpi_state->min_residency = 10; 1055 } 1056 1057 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1058 pr_debug("No wakeup residency found, assuming 10 us\n"); 1059 lpi_state->wake_latency = 10; 1060 } 1061 1062 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1063 lpi_state->flags = 0; 1064 1065 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1066 lpi_state->arch_flags = 0; 1067 1068 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1069 lpi_state->res_cnt_freq = 1; 1070 1071 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1072 lpi_state->enable_parent_state = 0; 1073 } 1074 1075 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1076 end: 1077 kfree(buffer.pointer); 1078 return ret; 1079 } 1080 1081 /* 1082 * flat_state_cnt - the number of composite LPI states after the process of flattening 1083 */ 1084 static int flat_state_cnt; 1085 1086 /** 1087 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1088 * 1089 * @local: local LPI state 1090 * @parent: parent LPI state 1091 * @result: composite LPI state 1092 */ 1093 static bool combine_lpi_states(struct acpi_lpi_state *local, 1094 struct acpi_lpi_state *parent, 1095 struct acpi_lpi_state *result) 1096 { 1097 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1098 if (!parent->address) /* 0 means autopromotable */ 1099 return false; 1100 result->address = local->address + parent->address; 1101 } else { 1102 result->address = parent->address; 1103 } 1104 1105 result->min_residency = max(local->min_residency, parent->min_residency); 1106 result->wake_latency = local->wake_latency + parent->wake_latency; 1107 result->enable_parent_state = parent->enable_parent_state; 1108 result->entry_method = local->entry_method; 1109 1110 result->flags = parent->flags; 1111 result->arch_flags = parent->arch_flags; 1112 result->index = parent->index; 1113 1114 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1115 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1116 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1117 return true; 1118 } 1119 1120 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1121 1122 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1123 struct acpi_lpi_state *t) 1124 { 1125 curr_level->composite_states[curr_level->composite_states_size++] = t; 1126 } 1127 1128 static int flatten_lpi_states(struct acpi_processor *pr, 1129 struct acpi_lpi_states_array *curr_level, 1130 struct acpi_lpi_states_array *prev_level) 1131 { 1132 int i, j, state_count = curr_level->size; 1133 struct acpi_lpi_state *p, *t = curr_level->entries; 1134 1135 curr_level->composite_states_size = 0; 1136 for (j = 0; j < state_count; j++, t++) { 1137 struct acpi_lpi_state *flpi; 1138 1139 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1140 continue; 1141 1142 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1143 pr_warn("Limiting number of LPI states to max (%d)\n", 1144 ACPI_PROCESSOR_MAX_POWER); 1145 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1146 break; 1147 } 1148 1149 flpi = &pr->power.lpi_states[flat_state_cnt]; 1150 1151 if (!prev_level) { /* leaf/processor node */ 1152 memcpy(flpi, t, sizeof(*t)); 1153 stash_composite_state(curr_level, flpi); 1154 flat_state_cnt++; 1155 continue; 1156 } 1157 1158 for (i = 0; i < prev_level->composite_states_size; i++) { 1159 p = prev_level->composite_states[i]; 1160 if (t->index <= p->enable_parent_state && 1161 combine_lpi_states(p, t, flpi)) { 1162 stash_composite_state(curr_level, flpi); 1163 flat_state_cnt++; 1164 flpi++; 1165 } 1166 } 1167 } 1168 1169 kfree(curr_level->entries); 1170 return 0; 1171 } 1172 1173 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1174 { 1175 int ret, i; 1176 acpi_status status; 1177 acpi_handle handle = pr->handle, pr_ahandle; 1178 struct acpi_device *d = NULL; 1179 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1180 1181 if (!osc_pc_lpi_support_confirmed) 1182 return -EOPNOTSUPP; 1183 1184 if (!acpi_has_method(handle, "_LPI")) 1185 return -EINVAL; 1186 1187 flat_state_cnt = 0; 1188 prev = &info[0]; 1189 curr = &info[1]; 1190 handle = pr->handle; 1191 ret = acpi_processor_evaluate_lpi(handle, prev); 1192 if (ret) 1193 return ret; 1194 flatten_lpi_states(pr, prev, NULL); 1195 1196 status = acpi_get_parent(handle, &pr_ahandle); 1197 while (ACPI_SUCCESS(status)) { 1198 acpi_bus_get_device(pr_ahandle, &d); 1199 handle = pr_ahandle; 1200 1201 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1202 break; 1203 1204 /* can be optional ? */ 1205 if (!acpi_has_method(handle, "_LPI")) 1206 break; 1207 1208 ret = acpi_processor_evaluate_lpi(handle, curr); 1209 if (ret) 1210 break; 1211 1212 /* flatten all the LPI states in this level of hierarchy */ 1213 flatten_lpi_states(pr, curr, prev); 1214 1215 tmp = prev, prev = curr, curr = tmp; 1216 1217 status = acpi_get_parent(handle, &pr_ahandle); 1218 } 1219 1220 pr->power.count = flat_state_cnt; 1221 /* reset the index after flattening */ 1222 for (i = 0; i < pr->power.count; i++) 1223 pr->power.lpi_states[i].index = i; 1224 1225 /* Tell driver that _LPI is supported. */ 1226 pr->flags.has_lpi = 1; 1227 pr->flags.power = 1; 1228 1229 return 0; 1230 } 1231 1232 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1233 { 1234 return -ENODEV; 1235 } 1236 1237 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1238 { 1239 return -ENODEV; 1240 } 1241 1242 /** 1243 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1244 * @dev: the target CPU 1245 * @drv: cpuidle driver containing cpuidle state info 1246 * @index: index of target state 1247 * 1248 * Return: 0 for success or negative value for error 1249 */ 1250 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1251 struct cpuidle_driver *drv, int index) 1252 { 1253 struct acpi_processor *pr; 1254 struct acpi_lpi_state *lpi; 1255 1256 pr = __this_cpu_read(processors); 1257 1258 if (unlikely(!pr)) 1259 return -EINVAL; 1260 1261 lpi = &pr->power.lpi_states[index]; 1262 if (lpi->entry_method == ACPI_CSTATE_FFH) 1263 return acpi_processor_ffh_lpi_enter(lpi); 1264 1265 return -EINVAL; 1266 } 1267 1268 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1269 { 1270 int i; 1271 struct acpi_lpi_state *lpi; 1272 struct cpuidle_state *state; 1273 struct cpuidle_driver *drv = &acpi_idle_driver; 1274 1275 if (!pr->flags.has_lpi) 1276 return -EOPNOTSUPP; 1277 1278 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1279 lpi = &pr->power.lpi_states[i]; 1280 1281 state = &drv->states[i]; 1282 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1283 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1284 state->exit_latency = lpi->wake_latency; 1285 state->target_residency = lpi->min_residency; 1286 if (lpi->arch_flags) 1287 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1288 state->enter = acpi_idle_lpi_enter; 1289 drv->safe_state_index = i; 1290 } 1291 1292 drv->state_count = i; 1293 1294 return 0; 1295 } 1296 1297 /** 1298 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1299 * global state data i.e. idle routines 1300 * 1301 * @pr: the ACPI processor 1302 */ 1303 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1304 { 1305 int i; 1306 struct cpuidle_driver *drv = &acpi_idle_driver; 1307 1308 if (!pr->flags.power_setup_done || !pr->flags.power) 1309 return -EINVAL; 1310 1311 drv->safe_state_index = -1; 1312 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1313 drv->states[i].name[0] = '\0'; 1314 drv->states[i].desc[0] = '\0'; 1315 } 1316 1317 if (pr->flags.has_lpi) 1318 return acpi_processor_setup_lpi_states(pr); 1319 1320 return acpi_processor_setup_cstates(pr); 1321 } 1322 1323 /** 1324 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1325 * device i.e. per-cpu data 1326 * 1327 * @pr: the ACPI processor 1328 * @dev : the cpuidle device 1329 */ 1330 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1331 struct cpuidle_device *dev) 1332 { 1333 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1334 return -EINVAL; 1335 1336 dev->cpu = pr->id; 1337 if (pr->flags.has_lpi) 1338 return acpi_processor_ffh_lpi_probe(pr->id); 1339 1340 return acpi_processor_setup_cpuidle_cx(pr, dev); 1341 } 1342 1343 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1344 { 1345 int ret; 1346 1347 ret = acpi_processor_get_lpi_info(pr); 1348 if (ret) 1349 ret = acpi_processor_get_cstate_info(pr); 1350 1351 return ret; 1352 } 1353 1354 int acpi_processor_hotplug(struct acpi_processor *pr) 1355 { 1356 int ret = 0; 1357 struct cpuidle_device *dev; 1358 1359 if (disabled_by_idle_boot_param()) 1360 return 0; 1361 1362 if (!pr->flags.power_setup_done) 1363 return -ENODEV; 1364 1365 dev = per_cpu(acpi_cpuidle_device, pr->id); 1366 cpuidle_pause_and_lock(); 1367 cpuidle_disable_device(dev); 1368 ret = acpi_processor_get_power_info(pr); 1369 if (!ret && pr->flags.power) { 1370 acpi_processor_setup_cpuidle_dev(pr, dev); 1371 ret = cpuidle_enable_device(dev); 1372 } 1373 cpuidle_resume_and_unlock(); 1374 1375 return ret; 1376 } 1377 1378 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1379 { 1380 int cpu; 1381 struct acpi_processor *_pr; 1382 struct cpuidle_device *dev; 1383 1384 if (disabled_by_idle_boot_param()) 1385 return 0; 1386 1387 if (!pr->flags.power_setup_done) 1388 return -ENODEV; 1389 1390 /* 1391 * FIXME: Design the ACPI notification to make it once per 1392 * system instead of once per-cpu. This condition is a hack 1393 * to make the code that updates C-States be called once. 1394 */ 1395 1396 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1397 1398 /* Protect against cpu-hotplug */ 1399 get_online_cpus(); 1400 cpuidle_pause_and_lock(); 1401 1402 /* Disable all cpuidle devices */ 1403 for_each_online_cpu(cpu) { 1404 _pr = per_cpu(processors, cpu); 1405 if (!_pr || !_pr->flags.power_setup_done) 1406 continue; 1407 dev = per_cpu(acpi_cpuidle_device, cpu); 1408 cpuidle_disable_device(dev); 1409 } 1410 1411 /* Populate Updated C-state information */ 1412 acpi_processor_get_power_info(pr); 1413 acpi_processor_setup_cpuidle_states(pr); 1414 1415 /* Enable all cpuidle devices */ 1416 for_each_online_cpu(cpu) { 1417 _pr = per_cpu(processors, cpu); 1418 if (!_pr || !_pr->flags.power_setup_done) 1419 continue; 1420 acpi_processor_get_power_info(_pr); 1421 if (_pr->flags.power) { 1422 dev = per_cpu(acpi_cpuidle_device, cpu); 1423 acpi_processor_setup_cpuidle_dev(_pr, dev); 1424 cpuidle_enable_device(dev); 1425 } 1426 } 1427 cpuidle_resume_and_unlock(); 1428 put_online_cpus(); 1429 } 1430 1431 return 0; 1432 } 1433 1434 static int acpi_processor_registered; 1435 1436 int acpi_processor_power_init(struct acpi_processor *pr) 1437 { 1438 int retval; 1439 struct cpuidle_device *dev; 1440 1441 if (disabled_by_idle_boot_param()) 1442 return 0; 1443 1444 acpi_processor_cstate_first_run_checks(); 1445 1446 if (!acpi_processor_get_power_info(pr)) 1447 pr->flags.power_setup_done = 1; 1448 1449 /* 1450 * Install the idle handler if processor power management is supported. 1451 * Note that we use previously set idle handler will be used on 1452 * platforms that only support C1. 1453 */ 1454 if (pr->flags.power) { 1455 /* Register acpi_idle_driver if not already registered */ 1456 if (!acpi_processor_registered) { 1457 acpi_processor_setup_cpuidle_states(pr); 1458 retval = cpuidle_register_driver(&acpi_idle_driver); 1459 if (retval) 1460 return retval; 1461 pr_debug("%s registered with cpuidle\n", 1462 acpi_idle_driver.name); 1463 } 1464 1465 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1466 if (!dev) 1467 return -ENOMEM; 1468 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1469 1470 acpi_processor_setup_cpuidle_dev(pr, dev); 1471 1472 /* Register per-cpu cpuidle_device. Cpuidle driver 1473 * must already be registered before registering device 1474 */ 1475 retval = cpuidle_register_device(dev); 1476 if (retval) { 1477 if (acpi_processor_registered == 0) 1478 cpuidle_unregister_driver(&acpi_idle_driver); 1479 return retval; 1480 } 1481 acpi_processor_registered++; 1482 } 1483 return 0; 1484 } 1485 1486 int acpi_processor_power_exit(struct acpi_processor *pr) 1487 { 1488 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1489 1490 if (disabled_by_idle_boot_param()) 1491 return 0; 1492 1493 if (pr->flags.power) { 1494 cpuidle_unregister_device(dev); 1495 acpi_processor_registered--; 1496 if (acpi_processor_registered == 0) 1497 cpuidle_unregister_driver(&acpi_idle_driver); 1498 } 1499 1500 pr->flags.power_setup_done = 0; 1501 return 0; 1502 } 1503