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 /** 646 * acpi_idle_do_entry - enter idle state using the appropriate method 647 * @cx: cstate data 648 * 649 * Caller disables interrupt before call and enables interrupt after return. 650 */ 651 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 652 { 653 if (cx->entry_method == ACPI_CSTATE_FFH) { 654 /* Call into architectural FFH based C-state */ 655 acpi_processor_ffh_cstate_enter(cx); 656 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 657 acpi_safe_halt(); 658 } else { 659 /* IO port based C-state */ 660 inb(cx->address); 661 /* Dummy wait op - must do something useless after P_LVL2 read 662 because chipsets cannot guarantee that STPCLK# signal 663 gets asserted in time to freeze execution properly. */ 664 inl(acpi_gbl_FADT.xpm_timer_block.address); 665 } 666 } 667 668 /** 669 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 670 * @dev: the target CPU 671 * @index: the index of suggested state 672 */ 673 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 674 { 675 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 676 677 ACPI_FLUSH_CPU_CACHE(); 678 679 while (1) { 680 681 if (cx->entry_method == ACPI_CSTATE_HALT) 682 safe_halt(); 683 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 684 inb(cx->address); 685 /* See comment in acpi_idle_do_entry() */ 686 inl(acpi_gbl_FADT.xpm_timer_block.address); 687 } else 688 return -ENODEV; 689 } 690 691 /* Never reached */ 692 return 0; 693 } 694 695 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 696 { 697 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 698 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 699 } 700 701 static int c3_cpu_count; 702 static DEFINE_RAW_SPINLOCK(c3_lock); 703 704 /** 705 * acpi_idle_enter_bm - enters C3 with proper BM handling 706 * @pr: Target processor 707 * @cx: Target state context 708 * @timer_bc: Whether or not to change timer mode to broadcast 709 */ 710 static void acpi_idle_enter_bm(struct acpi_processor *pr, 711 struct acpi_processor_cx *cx, bool timer_bc) 712 { 713 acpi_unlazy_tlb(smp_processor_id()); 714 715 /* 716 * Must be done before busmaster disable as we might need to 717 * access HPET ! 718 */ 719 if (timer_bc) 720 lapic_timer_state_broadcast(pr, cx, 1); 721 722 /* 723 * disable bus master 724 * bm_check implies we need ARB_DIS 725 * bm_control implies whether we can do ARB_DIS 726 * 727 * That leaves a case where bm_check is set and bm_control is 728 * not set. In that case we cannot do much, we enter C3 729 * without doing anything. 730 */ 731 if (pr->flags.bm_control) { 732 raw_spin_lock(&c3_lock); 733 c3_cpu_count++; 734 /* Disable bus master arbitration when all CPUs are in C3 */ 735 if (c3_cpu_count == num_online_cpus()) 736 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 737 raw_spin_unlock(&c3_lock); 738 } 739 740 acpi_idle_do_entry(cx); 741 742 /* Re-enable bus master arbitration */ 743 if (pr->flags.bm_control) { 744 raw_spin_lock(&c3_lock); 745 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 746 c3_cpu_count--; 747 raw_spin_unlock(&c3_lock); 748 } 749 750 if (timer_bc) 751 lapic_timer_state_broadcast(pr, cx, 0); 752 } 753 754 static int acpi_idle_enter(struct cpuidle_device *dev, 755 struct cpuidle_driver *drv, int index) 756 { 757 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 758 struct acpi_processor *pr; 759 760 pr = __this_cpu_read(processors); 761 if (unlikely(!pr)) 762 return -EINVAL; 763 764 if (cx->type != ACPI_STATE_C1) { 765 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 766 index = ACPI_IDLE_STATE_START; 767 cx = per_cpu(acpi_cstate[index], dev->cpu); 768 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 769 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 770 acpi_idle_enter_bm(pr, cx, true); 771 return index; 772 } else if (drv->safe_state_index >= 0) { 773 index = drv->safe_state_index; 774 cx = per_cpu(acpi_cstate[index], dev->cpu); 775 } else { 776 acpi_safe_halt(); 777 return -EBUSY; 778 } 779 } 780 } 781 782 lapic_timer_state_broadcast(pr, cx, 1); 783 784 if (cx->type == ACPI_STATE_C3) 785 ACPI_FLUSH_CPU_CACHE(); 786 787 acpi_idle_do_entry(cx); 788 789 lapic_timer_state_broadcast(pr, cx, 0); 790 791 return index; 792 } 793 794 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, 795 struct cpuidle_driver *drv, int index) 796 { 797 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 798 799 if (cx->type == ACPI_STATE_C3) { 800 struct acpi_processor *pr = __this_cpu_read(processors); 801 802 if (unlikely(!pr)) 803 return; 804 805 if (pr->flags.bm_check) { 806 acpi_idle_enter_bm(pr, cx, false); 807 return; 808 } else { 809 ACPI_FLUSH_CPU_CACHE(); 810 } 811 } 812 acpi_idle_do_entry(cx); 813 } 814 815 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 816 struct cpuidle_device *dev) 817 { 818 int i, count = ACPI_IDLE_STATE_START; 819 struct acpi_processor_cx *cx; 820 821 if (max_cstate == 0) 822 max_cstate = 1; 823 824 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 825 cx = &pr->power.states[i]; 826 827 if (!cx->valid) 828 continue; 829 830 per_cpu(acpi_cstate[count], dev->cpu) = cx; 831 832 count++; 833 if (count == CPUIDLE_STATE_MAX) 834 break; 835 } 836 837 if (!count) 838 return -EINVAL; 839 840 return 0; 841 } 842 843 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 844 { 845 int i, count; 846 struct acpi_processor_cx *cx; 847 struct cpuidle_state *state; 848 struct cpuidle_driver *drv = &acpi_idle_driver; 849 850 if (max_cstate == 0) 851 max_cstate = 1; 852 853 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 854 cpuidle_poll_state_init(drv); 855 count = 1; 856 } else { 857 count = 0; 858 } 859 860 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 861 cx = &pr->power.states[i]; 862 863 if (!cx->valid) 864 continue; 865 866 state = &drv->states[count]; 867 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 868 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 869 state->exit_latency = cx->latency; 870 state->target_residency = cx->latency * latency_factor; 871 state->enter = acpi_idle_enter; 872 873 state->flags = 0; 874 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 875 state->enter_dead = acpi_idle_play_dead; 876 drv->safe_state_index = count; 877 } 878 /* 879 * Halt-induced C1 is not good for ->enter_s2idle, because it 880 * re-enables interrupts on exit. Moreover, C1 is generally not 881 * particularly interesting from the suspend-to-idle angle, so 882 * avoid C1 and the situations in which we may need to fall back 883 * to it altogether. 884 */ 885 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 886 state->enter_s2idle = acpi_idle_enter_s2idle; 887 888 count++; 889 if (count == CPUIDLE_STATE_MAX) 890 break; 891 } 892 893 drv->state_count = count; 894 895 if (!count) 896 return -EINVAL; 897 898 return 0; 899 } 900 901 static inline void acpi_processor_cstate_first_run_checks(void) 902 { 903 acpi_status status; 904 static int first_run; 905 906 if (first_run) 907 return; 908 dmi_check_system(processor_power_dmi_table); 909 max_cstate = acpi_processor_cstate_check(max_cstate); 910 if (max_cstate < ACPI_C_STATES_MAX) 911 pr_notice("ACPI: processor limited to max C-state %d\n", 912 max_cstate); 913 first_run++; 914 915 if (acpi_gbl_FADT.cst_control && !nocst) { 916 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 917 acpi_gbl_FADT.cst_control, 8); 918 if (ACPI_FAILURE(status)) 919 ACPI_EXCEPTION((AE_INFO, status, 920 "Notifying BIOS of _CST ability failed")); 921 } 922 } 923 #else 924 925 static inline int disabled_by_idle_boot_param(void) { return 0; } 926 static inline void acpi_processor_cstate_first_run_checks(void) { } 927 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 928 { 929 return -ENODEV; 930 } 931 932 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 933 struct cpuidle_device *dev) 934 { 935 return -EINVAL; 936 } 937 938 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 939 { 940 return -EINVAL; 941 } 942 943 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 944 945 struct acpi_lpi_states_array { 946 unsigned int size; 947 unsigned int composite_states_size; 948 struct acpi_lpi_state *entries; 949 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 950 }; 951 952 static int obj_get_integer(union acpi_object *obj, u32 *value) 953 { 954 if (obj->type != ACPI_TYPE_INTEGER) 955 return -EINVAL; 956 957 *value = obj->integer.value; 958 return 0; 959 } 960 961 static int acpi_processor_evaluate_lpi(acpi_handle handle, 962 struct acpi_lpi_states_array *info) 963 { 964 acpi_status status; 965 int ret = 0; 966 int pkg_count, state_idx = 1, loop; 967 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 968 union acpi_object *lpi_data; 969 struct acpi_lpi_state *lpi_state; 970 971 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 972 if (ACPI_FAILURE(status)) { 973 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 974 return -ENODEV; 975 } 976 977 lpi_data = buffer.pointer; 978 979 /* There must be at least 4 elements = 3 elements + 1 package */ 980 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 981 lpi_data->package.count < 4) { 982 pr_debug("not enough elements in _LPI\n"); 983 ret = -ENODATA; 984 goto end; 985 } 986 987 pkg_count = lpi_data->package.elements[2].integer.value; 988 989 /* Validate number of power states. */ 990 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 991 pr_debug("count given by _LPI is not valid\n"); 992 ret = -ENODATA; 993 goto end; 994 } 995 996 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 997 if (!lpi_state) { 998 ret = -ENOMEM; 999 goto end; 1000 } 1001 1002 info->size = pkg_count; 1003 info->entries = lpi_state; 1004 1005 /* LPI States start at index 3 */ 1006 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 1007 union acpi_object *element, *pkg_elem, *obj; 1008 1009 element = &lpi_data->package.elements[loop]; 1010 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1011 continue; 1012 1013 pkg_elem = element->package.elements; 1014 1015 obj = pkg_elem + 6; 1016 if (obj->type == ACPI_TYPE_BUFFER) { 1017 struct acpi_power_register *reg; 1018 1019 reg = (struct acpi_power_register *)obj->buffer.pointer; 1020 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1021 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1022 continue; 1023 1024 lpi_state->address = reg->address; 1025 lpi_state->entry_method = 1026 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1027 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1028 } else if (obj->type == ACPI_TYPE_INTEGER) { 1029 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1030 lpi_state->address = obj->integer.value; 1031 } else { 1032 continue; 1033 } 1034 1035 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1036 1037 obj = pkg_elem + 9; 1038 if (obj->type == ACPI_TYPE_STRING) 1039 strlcpy(lpi_state->desc, obj->string.pointer, 1040 ACPI_CX_DESC_LEN); 1041 1042 lpi_state->index = state_idx; 1043 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1044 pr_debug("No min. residency found, assuming 10 us\n"); 1045 lpi_state->min_residency = 10; 1046 } 1047 1048 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1049 pr_debug("No wakeup residency found, assuming 10 us\n"); 1050 lpi_state->wake_latency = 10; 1051 } 1052 1053 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1054 lpi_state->flags = 0; 1055 1056 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1057 lpi_state->arch_flags = 0; 1058 1059 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1060 lpi_state->res_cnt_freq = 1; 1061 1062 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1063 lpi_state->enable_parent_state = 0; 1064 } 1065 1066 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1067 end: 1068 kfree(buffer.pointer); 1069 return ret; 1070 } 1071 1072 /* 1073 * flat_state_cnt - the number of composite LPI states after the process of flattening 1074 */ 1075 static int flat_state_cnt; 1076 1077 /** 1078 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1079 * 1080 * @local: local LPI state 1081 * @parent: parent LPI state 1082 * @result: composite LPI state 1083 */ 1084 static bool combine_lpi_states(struct acpi_lpi_state *local, 1085 struct acpi_lpi_state *parent, 1086 struct acpi_lpi_state *result) 1087 { 1088 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1089 if (!parent->address) /* 0 means autopromotable */ 1090 return false; 1091 result->address = local->address + parent->address; 1092 } else { 1093 result->address = parent->address; 1094 } 1095 1096 result->min_residency = max(local->min_residency, parent->min_residency); 1097 result->wake_latency = local->wake_latency + parent->wake_latency; 1098 result->enable_parent_state = parent->enable_parent_state; 1099 result->entry_method = local->entry_method; 1100 1101 result->flags = parent->flags; 1102 result->arch_flags = parent->arch_flags; 1103 result->index = parent->index; 1104 1105 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1106 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1107 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1108 return true; 1109 } 1110 1111 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1112 1113 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1114 struct acpi_lpi_state *t) 1115 { 1116 curr_level->composite_states[curr_level->composite_states_size++] = t; 1117 } 1118 1119 static int flatten_lpi_states(struct acpi_processor *pr, 1120 struct acpi_lpi_states_array *curr_level, 1121 struct acpi_lpi_states_array *prev_level) 1122 { 1123 int i, j, state_count = curr_level->size; 1124 struct acpi_lpi_state *p, *t = curr_level->entries; 1125 1126 curr_level->composite_states_size = 0; 1127 for (j = 0; j < state_count; j++, t++) { 1128 struct acpi_lpi_state *flpi; 1129 1130 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1131 continue; 1132 1133 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1134 pr_warn("Limiting number of LPI states to max (%d)\n", 1135 ACPI_PROCESSOR_MAX_POWER); 1136 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1137 break; 1138 } 1139 1140 flpi = &pr->power.lpi_states[flat_state_cnt]; 1141 1142 if (!prev_level) { /* leaf/processor node */ 1143 memcpy(flpi, t, sizeof(*t)); 1144 stash_composite_state(curr_level, flpi); 1145 flat_state_cnt++; 1146 continue; 1147 } 1148 1149 for (i = 0; i < prev_level->composite_states_size; i++) { 1150 p = prev_level->composite_states[i]; 1151 if (t->index <= p->enable_parent_state && 1152 combine_lpi_states(p, t, flpi)) { 1153 stash_composite_state(curr_level, flpi); 1154 flat_state_cnt++; 1155 flpi++; 1156 } 1157 } 1158 } 1159 1160 kfree(curr_level->entries); 1161 return 0; 1162 } 1163 1164 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1165 { 1166 int ret, i; 1167 acpi_status status; 1168 acpi_handle handle = pr->handle, pr_ahandle; 1169 struct acpi_device *d = NULL; 1170 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1171 1172 if (!osc_pc_lpi_support_confirmed) 1173 return -EOPNOTSUPP; 1174 1175 if (!acpi_has_method(handle, "_LPI")) 1176 return -EINVAL; 1177 1178 flat_state_cnt = 0; 1179 prev = &info[0]; 1180 curr = &info[1]; 1181 handle = pr->handle; 1182 ret = acpi_processor_evaluate_lpi(handle, prev); 1183 if (ret) 1184 return ret; 1185 flatten_lpi_states(pr, prev, NULL); 1186 1187 status = acpi_get_parent(handle, &pr_ahandle); 1188 while (ACPI_SUCCESS(status)) { 1189 acpi_bus_get_device(pr_ahandle, &d); 1190 handle = pr_ahandle; 1191 1192 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1193 break; 1194 1195 /* can be optional ? */ 1196 if (!acpi_has_method(handle, "_LPI")) 1197 break; 1198 1199 ret = acpi_processor_evaluate_lpi(handle, curr); 1200 if (ret) 1201 break; 1202 1203 /* flatten all the LPI states in this level of hierarchy */ 1204 flatten_lpi_states(pr, curr, prev); 1205 1206 tmp = prev, prev = curr, curr = tmp; 1207 1208 status = acpi_get_parent(handle, &pr_ahandle); 1209 } 1210 1211 pr->power.count = flat_state_cnt; 1212 /* reset the index after flattening */ 1213 for (i = 0; i < pr->power.count; i++) 1214 pr->power.lpi_states[i].index = i; 1215 1216 /* Tell driver that _LPI is supported. */ 1217 pr->flags.has_lpi = 1; 1218 pr->flags.power = 1; 1219 1220 return 0; 1221 } 1222 1223 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1224 { 1225 return -ENODEV; 1226 } 1227 1228 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1229 { 1230 return -ENODEV; 1231 } 1232 1233 /** 1234 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1235 * @dev: the target CPU 1236 * @drv: cpuidle driver containing cpuidle state info 1237 * @index: index of target state 1238 * 1239 * Return: 0 for success or negative value for error 1240 */ 1241 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1242 struct cpuidle_driver *drv, int index) 1243 { 1244 struct acpi_processor *pr; 1245 struct acpi_lpi_state *lpi; 1246 1247 pr = __this_cpu_read(processors); 1248 1249 if (unlikely(!pr)) 1250 return -EINVAL; 1251 1252 lpi = &pr->power.lpi_states[index]; 1253 if (lpi->entry_method == ACPI_CSTATE_FFH) 1254 return acpi_processor_ffh_lpi_enter(lpi); 1255 1256 return -EINVAL; 1257 } 1258 1259 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1260 { 1261 int i; 1262 struct acpi_lpi_state *lpi; 1263 struct cpuidle_state *state; 1264 struct cpuidle_driver *drv = &acpi_idle_driver; 1265 1266 if (!pr->flags.has_lpi) 1267 return -EOPNOTSUPP; 1268 1269 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1270 lpi = &pr->power.lpi_states[i]; 1271 1272 state = &drv->states[i]; 1273 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1274 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1275 state->exit_latency = lpi->wake_latency; 1276 state->target_residency = lpi->min_residency; 1277 if (lpi->arch_flags) 1278 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1279 state->enter = acpi_idle_lpi_enter; 1280 drv->safe_state_index = i; 1281 } 1282 1283 drv->state_count = i; 1284 1285 return 0; 1286 } 1287 1288 /** 1289 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1290 * global state data i.e. idle routines 1291 * 1292 * @pr: the ACPI processor 1293 */ 1294 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1295 { 1296 int i; 1297 struct cpuidle_driver *drv = &acpi_idle_driver; 1298 1299 if (!pr->flags.power_setup_done || !pr->flags.power) 1300 return -EINVAL; 1301 1302 drv->safe_state_index = -1; 1303 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1304 drv->states[i].name[0] = '\0'; 1305 drv->states[i].desc[0] = '\0'; 1306 } 1307 1308 if (pr->flags.has_lpi) 1309 return acpi_processor_setup_lpi_states(pr); 1310 1311 return acpi_processor_setup_cstates(pr); 1312 } 1313 1314 /** 1315 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1316 * device i.e. per-cpu data 1317 * 1318 * @pr: the ACPI processor 1319 * @dev : the cpuidle device 1320 */ 1321 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1322 struct cpuidle_device *dev) 1323 { 1324 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1325 return -EINVAL; 1326 1327 dev->cpu = pr->id; 1328 if (pr->flags.has_lpi) 1329 return acpi_processor_ffh_lpi_probe(pr->id); 1330 1331 return acpi_processor_setup_cpuidle_cx(pr, dev); 1332 } 1333 1334 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1335 { 1336 int ret; 1337 1338 ret = acpi_processor_get_lpi_info(pr); 1339 if (ret) 1340 ret = acpi_processor_get_cstate_info(pr); 1341 1342 return ret; 1343 } 1344 1345 int acpi_processor_hotplug(struct acpi_processor *pr) 1346 { 1347 int ret = 0; 1348 struct cpuidle_device *dev; 1349 1350 if (disabled_by_idle_boot_param()) 1351 return 0; 1352 1353 if (!pr->flags.power_setup_done) 1354 return -ENODEV; 1355 1356 dev = per_cpu(acpi_cpuidle_device, pr->id); 1357 cpuidle_pause_and_lock(); 1358 cpuidle_disable_device(dev); 1359 ret = acpi_processor_get_power_info(pr); 1360 if (!ret && pr->flags.power) { 1361 acpi_processor_setup_cpuidle_dev(pr, dev); 1362 ret = cpuidle_enable_device(dev); 1363 } 1364 cpuidle_resume_and_unlock(); 1365 1366 return ret; 1367 } 1368 1369 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1370 { 1371 int cpu; 1372 struct acpi_processor *_pr; 1373 struct cpuidle_device *dev; 1374 1375 if (disabled_by_idle_boot_param()) 1376 return 0; 1377 1378 if (!pr->flags.power_setup_done) 1379 return -ENODEV; 1380 1381 /* 1382 * FIXME: Design the ACPI notification to make it once per 1383 * system instead of once per-cpu. This condition is a hack 1384 * to make the code that updates C-States be called once. 1385 */ 1386 1387 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1388 1389 /* Protect against cpu-hotplug */ 1390 get_online_cpus(); 1391 cpuidle_pause_and_lock(); 1392 1393 /* Disable all cpuidle devices */ 1394 for_each_online_cpu(cpu) { 1395 _pr = per_cpu(processors, cpu); 1396 if (!_pr || !_pr->flags.power_setup_done) 1397 continue; 1398 dev = per_cpu(acpi_cpuidle_device, cpu); 1399 cpuidle_disable_device(dev); 1400 } 1401 1402 /* Populate Updated C-state information */ 1403 acpi_processor_get_power_info(pr); 1404 acpi_processor_setup_cpuidle_states(pr); 1405 1406 /* Enable all cpuidle devices */ 1407 for_each_online_cpu(cpu) { 1408 _pr = per_cpu(processors, cpu); 1409 if (!_pr || !_pr->flags.power_setup_done) 1410 continue; 1411 acpi_processor_get_power_info(_pr); 1412 if (_pr->flags.power) { 1413 dev = per_cpu(acpi_cpuidle_device, cpu); 1414 acpi_processor_setup_cpuidle_dev(_pr, dev); 1415 cpuidle_enable_device(dev); 1416 } 1417 } 1418 cpuidle_resume_and_unlock(); 1419 put_online_cpus(); 1420 } 1421 1422 return 0; 1423 } 1424 1425 static int acpi_processor_registered; 1426 1427 int acpi_processor_power_init(struct acpi_processor *pr) 1428 { 1429 int retval; 1430 struct cpuidle_device *dev; 1431 1432 if (disabled_by_idle_boot_param()) 1433 return 0; 1434 1435 acpi_processor_cstate_first_run_checks(); 1436 1437 if (!acpi_processor_get_power_info(pr)) 1438 pr->flags.power_setup_done = 1; 1439 1440 /* 1441 * Install the idle handler if processor power management is supported. 1442 * Note that we use previously set idle handler will be used on 1443 * platforms that only support C1. 1444 */ 1445 if (pr->flags.power) { 1446 /* Register acpi_idle_driver if not already registered */ 1447 if (!acpi_processor_registered) { 1448 acpi_processor_setup_cpuidle_states(pr); 1449 retval = cpuidle_register_driver(&acpi_idle_driver); 1450 if (retval) 1451 return retval; 1452 pr_debug("%s registered with cpuidle\n", 1453 acpi_idle_driver.name); 1454 } 1455 1456 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1457 if (!dev) 1458 return -ENOMEM; 1459 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1460 1461 acpi_processor_setup_cpuidle_dev(pr, dev); 1462 1463 /* Register per-cpu cpuidle_device. Cpuidle driver 1464 * must already be registered before registering device 1465 */ 1466 retval = cpuidle_register_device(dev); 1467 if (retval) { 1468 if (acpi_processor_registered == 0) 1469 cpuidle_unregister_driver(&acpi_idle_driver); 1470 return retval; 1471 } 1472 acpi_processor_registered++; 1473 } 1474 return 0; 1475 } 1476 1477 int acpi_processor_power_exit(struct acpi_processor *pr) 1478 { 1479 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1480 1481 if (disabled_by_idle_boot_param()) 1482 return 0; 1483 1484 if (pr->flags.power) { 1485 cpuidle_unregister_device(dev); 1486 acpi_processor_registered--; 1487 if (acpi_processor_registered == 0) 1488 cpuidle_unregister_driver(&acpi_idle_driver); 1489 } 1490 1491 pr->flags.power_setup_done = 0; 1492 return 0; 1493 } 1494