1 /* 2 * processor_idle - idle state submodule to the ACPI processor driver 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de> 7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 8 * - Added processor hotplug support 9 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 10 * - Added support for C3 on SMP 11 * 12 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License as published by 16 * the Free Software Foundation; either version 2 of the License, or (at 17 * your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 * 24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 25 */ 26 #define pr_fmt(fmt) "ACPI: " fmt 27 28 #include <linux/module.h> 29 #include <linux/acpi.h> 30 #include <linux/dmi.h> 31 #include <linux/sched.h> /* need_resched() */ 32 #include <linux/tick.h> 33 #include <linux/cpuidle.h> 34 #include <linux/cpu.h> 35 #include <acpi/processor.h> 36 37 /* 38 * Include the apic definitions for x86 to have the APIC timer related defines 39 * available also for UP (on SMP it gets magically included via linux/smp.h). 40 * asm/acpi.h is not an option, as it would require more include magic. Also 41 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 42 */ 43 #ifdef CONFIG_X86 44 #include <asm/apic.h> 45 #endif 46 47 #define ACPI_PROCESSOR_CLASS "processor" 48 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 49 ACPI_MODULE_NAME("processor_idle"); 50 51 #define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) 52 53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 54 module_param(max_cstate, uint, 0000); 55 static unsigned int nocst __read_mostly; 56 module_param(nocst, uint, 0000); 57 static int bm_check_disable __read_mostly; 58 module_param(bm_check_disable, uint, 0000); 59 60 static unsigned int latency_factor __read_mostly = 2; 61 module_param(latency_factor, uint, 0644); 62 63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 64 65 struct cpuidle_driver acpi_idle_driver = { 66 .name = "acpi_idle", 67 .owner = THIS_MODULE, 68 }; 69 70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE 71 static 72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate); 73 74 static int disabled_by_idle_boot_param(void) 75 { 76 return boot_option_idle_override == IDLE_POLL || 77 boot_option_idle_override == IDLE_HALT; 78 } 79 80 /* 81 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 82 * For now disable this. Probably a bug somewhere else. 83 * 84 * To skip this limit, boot/load with a large max_cstate limit. 85 */ 86 static int set_max_cstate(const struct dmi_system_id *id) 87 { 88 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 89 return 0; 90 91 pr_notice("%s detected - limiting to C%ld max_cstate." 92 " Override with \"processor.max_cstate=%d\"\n", id->ident, 93 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 94 95 max_cstate = (long)id->driver_data; 96 97 return 0; 98 } 99 100 static const struct dmi_system_id processor_power_dmi_table[] = { 101 { set_max_cstate, "Clevo 5600D", { 102 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 103 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 104 (void *)2}, 105 { set_max_cstate, "Pavilion zv5000", { 106 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 107 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 108 (void *)1}, 109 { set_max_cstate, "Asus L8400B", { 110 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 111 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 112 (void *)1}, 113 {}, 114 }; 115 116 117 /* 118 * Callers should disable interrupts before the call and enable 119 * interrupts after return. 120 */ 121 static void __cpuidle acpi_safe_halt(void) 122 { 123 if (!tif_need_resched()) { 124 safe_halt(); 125 local_irq_disable(); 126 } 127 } 128 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3 130 131 /* 132 * Some BIOS implementations switch to C3 in the published C2 state. 133 * This seems to be a common problem on AMD boxen, but other vendors 134 * are affected too. We pick the most conservative approach: we assume 135 * that the local APIC stops in both C2 and C3. 136 */ 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 138 struct acpi_processor_cx *cx) 139 { 140 struct acpi_processor_power *pwr = &pr->power; 141 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 142 143 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 144 return; 145 146 if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) 147 type = ACPI_STATE_C1; 148 149 /* 150 * Check, if one of the previous states already marked the lapic 151 * unstable 152 */ 153 if (pwr->timer_broadcast_on_state < state) 154 return; 155 156 if (cx->type >= type) 157 pr->power.timer_broadcast_on_state = state; 158 } 159 160 static void __lapic_timer_propagate_broadcast(void *arg) 161 { 162 struct acpi_processor *pr = (struct acpi_processor *) arg; 163 164 if (pr->power.timer_broadcast_on_state < INT_MAX) 165 tick_broadcast_enable(); 166 else 167 tick_broadcast_disable(); 168 } 169 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 171 { 172 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 173 (void *)pr, 1); 174 } 175 176 /* Power(C) State timer broadcast control */ 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 178 struct acpi_processor_cx *cx, 179 int broadcast) 180 { 181 int state = cx - pr->power.states; 182 183 if (state >= pr->power.timer_broadcast_on_state) { 184 if (broadcast) 185 tick_broadcast_enter(); 186 else 187 tick_broadcast_exit(); 188 } 189 } 190 191 #else 192 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 194 struct acpi_processor_cx *cstate) { } 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 197 struct acpi_processor_cx *cx, 198 int broadcast) 199 { 200 } 201 202 #endif 203 204 #if defined(CONFIG_X86) 205 static void tsc_check_state(int state) 206 { 207 switch (boot_cpu_data.x86_vendor) { 208 case X86_VENDOR_HYGON: 209 case X86_VENDOR_AMD: 210 case X86_VENDOR_INTEL: 211 case X86_VENDOR_CENTAUR: 212 /* 213 * AMD Fam10h TSC will tick in all 214 * C/P/S0/S1 states when this bit is set. 215 */ 216 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 217 return; 218 219 /*FALL THROUGH*/ 220 default: 221 /* TSC could halt in idle, so notify users */ 222 if (state > ACPI_STATE_C1) 223 mark_tsc_unstable("TSC halts in idle"); 224 } 225 } 226 #else 227 static void tsc_check_state(int state) { return; } 228 #endif 229 230 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 231 { 232 233 if (!pr->pblk) 234 return -ENODEV; 235 236 /* if info is obtained from pblk/fadt, type equals state */ 237 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 238 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 239 240 #ifndef CONFIG_HOTPLUG_CPU 241 /* 242 * Check for P_LVL2_UP flag before entering C2 and above on 243 * an SMP system. 244 */ 245 if ((num_online_cpus() > 1) && 246 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 247 return -ENODEV; 248 #endif 249 250 /* determine C2 and C3 address from pblk */ 251 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 252 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 253 254 /* determine latencies from FADT */ 255 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 256 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 257 258 /* 259 * FADT specified C2 latency must be less than or equal to 260 * 100 microseconds. 261 */ 262 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 263 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 264 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 265 /* invalidate C2 */ 266 pr->power.states[ACPI_STATE_C2].address = 0; 267 } 268 269 /* 270 * FADT supplied C3 latency must be less than or equal to 271 * 1000 microseconds. 272 */ 273 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 274 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 275 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 276 /* invalidate C3 */ 277 pr->power.states[ACPI_STATE_C3].address = 0; 278 } 279 280 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 281 "lvl2[0x%08x] lvl3[0x%08x]\n", 282 pr->power.states[ACPI_STATE_C2].address, 283 pr->power.states[ACPI_STATE_C3].address)); 284 285 snprintf(pr->power.states[ACPI_STATE_C2].desc, 286 ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x", 287 pr->power.states[ACPI_STATE_C2].address); 288 snprintf(pr->power.states[ACPI_STATE_C3].desc, 289 ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x", 290 pr->power.states[ACPI_STATE_C3].address); 291 292 return 0; 293 } 294 295 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 296 { 297 if (!pr->power.states[ACPI_STATE_C1].valid) { 298 /* set the first C-State to C1 */ 299 /* all processors need to support C1 */ 300 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 301 pr->power.states[ACPI_STATE_C1].valid = 1; 302 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 303 304 snprintf(pr->power.states[ACPI_STATE_C1].desc, 305 ACPI_CX_DESC_LEN, "ACPI HLT"); 306 } 307 /* the C0 state only exists as a filler in our array */ 308 pr->power.states[ACPI_STATE_C0].valid = 1; 309 return 0; 310 } 311 312 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 313 { 314 acpi_status status; 315 u64 count; 316 int current_count; 317 int i, ret = 0; 318 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 319 union acpi_object *cst; 320 321 if (nocst) 322 return -ENODEV; 323 324 current_count = 0; 325 326 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 327 if (ACPI_FAILURE(status)) { 328 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 329 return -ENODEV; 330 } 331 332 cst = buffer.pointer; 333 334 /* There must be at least 2 elements */ 335 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 336 pr_err("not enough elements in _CST\n"); 337 ret = -EFAULT; 338 goto end; 339 } 340 341 count = cst->package.elements[0].integer.value; 342 343 /* Validate number of power states. */ 344 if (count < 1 || count != cst->package.count - 1) { 345 pr_err("count given by _CST is not valid\n"); 346 ret = -EFAULT; 347 goto end; 348 } 349 350 /* Tell driver that at least _CST is supported. */ 351 pr->flags.has_cst = 1; 352 353 for (i = 1; i <= count; i++) { 354 union acpi_object *element; 355 union acpi_object *obj; 356 struct acpi_power_register *reg; 357 struct acpi_processor_cx cx; 358 359 memset(&cx, 0, sizeof(cx)); 360 361 element = &(cst->package.elements[i]); 362 if (element->type != ACPI_TYPE_PACKAGE) 363 continue; 364 365 if (element->package.count != 4) 366 continue; 367 368 obj = &(element->package.elements[0]); 369 370 if (obj->type != ACPI_TYPE_BUFFER) 371 continue; 372 373 reg = (struct acpi_power_register *)obj->buffer.pointer; 374 375 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 376 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 377 continue; 378 379 /* There should be an easy way to extract an integer... */ 380 obj = &(element->package.elements[1]); 381 if (obj->type != ACPI_TYPE_INTEGER) 382 continue; 383 384 cx.type = obj->integer.value; 385 /* 386 * Some buggy BIOSes won't list C1 in _CST - 387 * Let acpi_processor_get_power_info_default() handle them later 388 */ 389 if (i == 1 && cx.type != ACPI_STATE_C1) 390 current_count++; 391 392 cx.address = reg->address; 393 cx.index = current_count + 1; 394 395 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 396 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 397 if (acpi_processor_ffh_cstate_probe 398 (pr->id, &cx, reg) == 0) { 399 cx.entry_method = ACPI_CSTATE_FFH; 400 } else if (cx.type == ACPI_STATE_C1) { 401 /* 402 * C1 is a special case where FIXED_HARDWARE 403 * can be handled in non-MWAIT way as well. 404 * In that case, save this _CST entry info. 405 * Otherwise, ignore this info and continue. 406 */ 407 cx.entry_method = ACPI_CSTATE_HALT; 408 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 409 } else { 410 continue; 411 } 412 if (cx.type == ACPI_STATE_C1 && 413 (boot_option_idle_override == IDLE_NOMWAIT)) { 414 /* 415 * In most cases the C1 space_id obtained from 416 * _CST object is FIXED_HARDWARE access mode. 417 * But when the option of idle=halt is added, 418 * the entry_method type should be changed from 419 * CSTATE_FFH to CSTATE_HALT. 420 * When the option of idle=nomwait is added, 421 * the C1 entry_method type should be 422 * CSTATE_HALT. 423 */ 424 cx.entry_method = ACPI_CSTATE_HALT; 425 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 426 } 427 } else { 428 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 429 cx.address); 430 } 431 432 if (cx.type == ACPI_STATE_C1) { 433 cx.valid = 1; 434 } 435 436 obj = &(element->package.elements[2]); 437 if (obj->type != ACPI_TYPE_INTEGER) 438 continue; 439 440 cx.latency = obj->integer.value; 441 442 obj = &(element->package.elements[3]); 443 if (obj->type != ACPI_TYPE_INTEGER) 444 continue; 445 446 current_count++; 447 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 448 449 /* 450 * We support total ACPI_PROCESSOR_MAX_POWER - 1 451 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 452 */ 453 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 454 pr_warn("Limiting number of power states to max (%d)\n", 455 ACPI_PROCESSOR_MAX_POWER); 456 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 457 break; 458 } 459 } 460 461 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 462 current_count)); 463 464 /* Validate number of power states discovered */ 465 if (current_count < 2) 466 ret = -EFAULT; 467 468 end: 469 kfree(buffer.pointer); 470 471 return ret; 472 } 473 474 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 475 struct acpi_processor_cx *cx) 476 { 477 static int bm_check_flag = -1; 478 static int bm_control_flag = -1; 479 480 481 if (!cx->address) 482 return; 483 484 /* 485 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 486 * DMA transfers are used by any ISA device to avoid livelock. 487 * Note that we could disable Type-F DMA (as recommended by 488 * the erratum), but this is known to disrupt certain ISA 489 * devices thus we take the conservative approach. 490 */ 491 else if (errata.piix4.fdma) { 492 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 493 "C3 not supported on PIIX4 with Type-F DMA\n")); 494 return; 495 } 496 497 /* All the logic here assumes flags.bm_check is same across all CPUs */ 498 if (bm_check_flag == -1) { 499 /* Determine whether bm_check is needed based on CPU */ 500 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 501 bm_check_flag = pr->flags.bm_check; 502 bm_control_flag = pr->flags.bm_control; 503 } else { 504 pr->flags.bm_check = bm_check_flag; 505 pr->flags.bm_control = bm_control_flag; 506 } 507 508 if (pr->flags.bm_check) { 509 if (!pr->flags.bm_control) { 510 if (pr->flags.has_cst != 1) { 511 /* bus mastering control is necessary */ 512 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 513 "C3 support requires BM control\n")); 514 return; 515 } else { 516 /* Here we enter C3 without bus mastering */ 517 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 518 "C3 support without BM control\n")); 519 } 520 } 521 } else { 522 /* 523 * WBINVD should be set in fadt, for C3 state to be 524 * supported on when bm_check is not required. 525 */ 526 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 527 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 528 "Cache invalidation should work properly" 529 " for C3 to be enabled on SMP systems\n")); 530 return; 531 } 532 } 533 534 /* 535 * Otherwise we've met all of our C3 requirements. 536 * Normalize the C3 latency to expidite policy. Enable 537 * checking of bus mastering status (bm_check) so we can 538 * use this in our C3 policy 539 */ 540 cx->valid = 1; 541 542 /* 543 * On older chipsets, BM_RLD needs to be set 544 * in order for Bus Master activity to wake the 545 * system from C3. Newer chipsets handle DMA 546 * during C3 automatically and BM_RLD is a NOP. 547 * In either case, the proper way to 548 * handle BM_RLD is to set it and leave it set. 549 */ 550 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 551 552 return; 553 } 554 555 static int acpi_processor_power_verify(struct acpi_processor *pr) 556 { 557 unsigned int i; 558 unsigned int working = 0; 559 560 pr->power.timer_broadcast_on_state = INT_MAX; 561 562 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 563 struct acpi_processor_cx *cx = &pr->power.states[i]; 564 565 switch (cx->type) { 566 case ACPI_STATE_C1: 567 cx->valid = 1; 568 break; 569 570 case ACPI_STATE_C2: 571 if (!cx->address) 572 break; 573 cx->valid = 1; 574 break; 575 576 case ACPI_STATE_C3: 577 acpi_processor_power_verify_c3(pr, cx); 578 break; 579 } 580 if (!cx->valid) 581 continue; 582 583 lapic_timer_check_state(i, pr, cx); 584 tsc_check_state(cx->type); 585 working++; 586 } 587 588 lapic_timer_propagate_broadcast(pr); 589 590 return (working); 591 } 592 593 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 594 { 595 unsigned int i; 596 int result; 597 598 599 /* NOTE: the idle thread may not be running while calling 600 * this function */ 601 602 /* Zero initialize all the C-states info. */ 603 memset(pr->power.states, 0, sizeof(pr->power.states)); 604 605 result = acpi_processor_get_power_info_cst(pr); 606 if (result == -ENODEV) 607 result = acpi_processor_get_power_info_fadt(pr); 608 609 if (result) 610 return result; 611 612 acpi_processor_get_power_info_default(pr); 613 614 pr->power.count = acpi_processor_power_verify(pr); 615 616 /* 617 * if one state of type C2 or C3 is available, mark this 618 * CPU as being "idle manageable" 619 */ 620 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 621 if (pr->power.states[i].valid) { 622 pr->power.count = i; 623 if (pr->power.states[i].type >= ACPI_STATE_C2) 624 pr->flags.power = 1; 625 } 626 } 627 628 return 0; 629 } 630 631 /** 632 * acpi_idle_bm_check - checks if bus master activity was detected 633 */ 634 static int acpi_idle_bm_check(void) 635 { 636 u32 bm_status = 0; 637 638 if (bm_check_disable) 639 return 0; 640 641 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 642 if (bm_status) 643 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 644 /* 645 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 646 * the true state of bus mastering activity; forcing us to 647 * manually check the BMIDEA bit of each IDE channel. 648 */ 649 else if (errata.piix4.bmisx) { 650 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 651 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 652 bm_status = 1; 653 } 654 return bm_status; 655 } 656 657 /** 658 * acpi_idle_do_entry - enter idle state using the appropriate method 659 * @cx: cstate data 660 * 661 * Caller disables interrupt before call and enables interrupt after return. 662 */ 663 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx) 664 { 665 if (cx->entry_method == ACPI_CSTATE_FFH) { 666 /* Call into architectural FFH based C-state */ 667 acpi_processor_ffh_cstate_enter(cx); 668 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 669 acpi_safe_halt(); 670 } else { 671 /* IO port based C-state */ 672 inb(cx->address); 673 /* Dummy wait op - must do something useless after P_LVL2 read 674 because chipsets cannot guarantee that STPCLK# signal 675 gets asserted in time to freeze execution properly. */ 676 inl(acpi_gbl_FADT.xpm_timer_block.address); 677 } 678 } 679 680 /** 681 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 682 * @dev: the target CPU 683 * @index: the index of suggested state 684 */ 685 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 686 { 687 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 688 689 ACPI_FLUSH_CPU_CACHE(); 690 691 while (1) { 692 693 if (cx->entry_method == ACPI_CSTATE_HALT) 694 safe_halt(); 695 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 696 inb(cx->address); 697 /* See comment in acpi_idle_do_entry() */ 698 inl(acpi_gbl_FADT.xpm_timer_block.address); 699 } else 700 return -ENODEV; 701 } 702 703 /* Never reached */ 704 return 0; 705 } 706 707 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 708 { 709 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && 710 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); 711 } 712 713 static int c3_cpu_count; 714 static DEFINE_RAW_SPINLOCK(c3_lock); 715 716 /** 717 * acpi_idle_enter_bm - enters C3 with proper BM handling 718 * @pr: Target processor 719 * @cx: Target state context 720 * @timer_bc: Whether or not to change timer mode to broadcast 721 */ 722 static void acpi_idle_enter_bm(struct acpi_processor *pr, 723 struct acpi_processor_cx *cx, bool timer_bc) 724 { 725 acpi_unlazy_tlb(smp_processor_id()); 726 727 /* 728 * Must be done before busmaster disable as we might need to 729 * access HPET ! 730 */ 731 if (timer_bc) 732 lapic_timer_state_broadcast(pr, cx, 1); 733 734 /* 735 * disable bus master 736 * bm_check implies we need ARB_DIS 737 * bm_control implies whether we can do ARB_DIS 738 * 739 * That leaves a case where bm_check is set and bm_control is 740 * not set. In that case we cannot do much, we enter C3 741 * without doing anything. 742 */ 743 if (pr->flags.bm_control) { 744 raw_spin_lock(&c3_lock); 745 c3_cpu_count++; 746 /* Disable bus master arbitration when all CPUs are in C3 */ 747 if (c3_cpu_count == num_online_cpus()) 748 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 749 raw_spin_unlock(&c3_lock); 750 } 751 752 acpi_idle_do_entry(cx); 753 754 /* Re-enable bus master arbitration */ 755 if (pr->flags.bm_control) { 756 raw_spin_lock(&c3_lock); 757 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 758 c3_cpu_count--; 759 raw_spin_unlock(&c3_lock); 760 } 761 762 if (timer_bc) 763 lapic_timer_state_broadcast(pr, cx, 0); 764 } 765 766 static int acpi_idle_enter(struct cpuidle_device *dev, 767 struct cpuidle_driver *drv, int index) 768 { 769 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 770 struct acpi_processor *pr; 771 772 pr = __this_cpu_read(processors); 773 if (unlikely(!pr)) 774 return -EINVAL; 775 776 if (cx->type != ACPI_STATE_C1) { 777 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { 778 index = ACPI_IDLE_STATE_START; 779 cx = per_cpu(acpi_cstate[index], dev->cpu); 780 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 781 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 782 acpi_idle_enter_bm(pr, cx, true); 783 return index; 784 } else if (drv->safe_state_index >= 0) { 785 index = drv->safe_state_index; 786 cx = per_cpu(acpi_cstate[index], dev->cpu); 787 } else { 788 acpi_safe_halt(); 789 return -EBUSY; 790 } 791 } 792 } 793 794 lapic_timer_state_broadcast(pr, cx, 1); 795 796 if (cx->type == ACPI_STATE_C3) 797 ACPI_FLUSH_CPU_CACHE(); 798 799 acpi_idle_do_entry(cx); 800 801 lapic_timer_state_broadcast(pr, cx, 0); 802 803 return index; 804 } 805 806 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, 807 struct cpuidle_driver *drv, int index) 808 { 809 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 810 811 if (cx->type == ACPI_STATE_C3) { 812 struct acpi_processor *pr = __this_cpu_read(processors); 813 814 if (unlikely(!pr)) 815 return; 816 817 if (pr->flags.bm_check) { 818 acpi_idle_enter_bm(pr, cx, false); 819 return; 820 } else { 821 ACPI_FLUSH_CPU_CACHE(); 822 } 823 } 824 acpi_idle_do_entry(cx); 825 } 826 827 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 828 struct cpuidle_device *dev) 829 { 830 int i, count = ACPI_IDLE_STATE_START; 831 struct acpi_processor_cx *cx; 832 833 if (max_cstate == 0) 834 max_cstate = 1; 835 836 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 837 cx = &pr->power.states[i]; 838 839 if (!cx->valid) 840 continue; 841 842 per_cpu(acpi_cstate[count], dev->cpu) = cx; 843 844 count++; 845 if (count == CPUIDLE_STATE_MAX) 846 break; 847 } 848 849 if (!count) 850 return -EINVAL; 851 852 return 0; 853 } 854 855 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 856 { 857 int i, count; 858 struct acpi_processor_cx *cx; 859 struct cpuidle_state *state; 860 struct cpuidle_driver *drv = &acpi_idle_driver; 861 862 if (max_cstate == 0) 863 max_cstate = 1; 864 865 if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { 866 cpuidle_poll_state_init(drv); 867 count = 1; 868 } else { 869 count = 0; 870 } 871 872 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 873 cx = &pr->power.states[i]; 874 875 if (!cx->valid) 876 continue; 877 878 state = &drv->states[count]; 879 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 880 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 881 state->exit_latency = cx->latency; 882 state->target_residency = cx->latency * latency_factor; 883 state->enter = acpi_idle_enter; 884 885 state->flags = 0; 886 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 887 state->enter_dead = acpi_idle_play_dead; 888 drv->safe_state_index = count; 889 } 890 /* 891 * Halt-induced C1 is not good for ->enter_s2idle, because it 892 * re-enables interrupts on exit. Moreover, C1 is generally not 893 * particularly interesting from the suspend-to-idle angle, so 894 * avoid C1 and the situations in which we may need to fall back 895 * to it altogether. 896 */ 897 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) 898 state->enter_s2idle = acpi_idle_enter_s2idle; 899 900 count++; 901 if (count == CPUIDLE_STATE_MAX) 902 break; 903 } 904 905 drv->state_count = count; 906 907 if (!count) 908 return -EINVAL; 909 910 return 0; 911 } 912 913 static inline void acpi_processor_cstate_first_run_checks(void) 914 { 915 acpi_status status; 916 static int first_run; 917 918 if (first_run) 919 return; 920 dmi_check_system(processor_power_dmi_table); 921 max_cstate = acpi_processor_cstate_check(max_cstate); 922 if (max_cstate < ACPI_C_STATES_MAX) 923 pr_notice("ACPI: processor limited to max C-state %d\n", 924 max_cstate); 925 first_run++; 926 927 if (acpi_gbl_FADT.cst_control && !nocst) { 928 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 929 acpi_gbl_FADT.cst_control, 8); 930 if (ACPI_FAILURE(status)) 931 ACPI_EXCEPTION((AE_INFO, status, 932 "Notifying BIOS of _CST ability failed")); 933 } 934 } 935 #else 936 937 static inline int disabled_by_idle_boot_param(void) { return 0; } 938 static inline void acpi_processor_cstate_first_run_checks(void) { } 939 static int acpi_processor_get_cstate_info(struct acpi_processor *pr) 940 { 941 return -ENODEV; 942 } 943 944 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 945 struct cpuidle_device *dev) 946 { 947 return -EINVAL; 948 } 949 950 static int acpi_processor_setup_cstates(struct acpi_processor *pr) 951 { 952 return -EINVAL; 953 } 954 955 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ 956 957 struct acpi_lpi_states_array { 958 unsigned int size; 959 unsigned int composite_states_size; 960 struct acpi_lpi_state *entries; 961 struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; 962 }; 963 964 static int obj_get_integer(union acpi_object *obj, u32 *value) 965 { 966 if (obj->type != ACPI_TYPE_INTEGER) 967 return -EINVAL; 968 969 *value = obj->integer.value; 970 return 0; 971 } 972 973 static int acpi_processor_evaluate_lpi(acpi_handle handle, 974 struct acpi_lpi_states_array *info) 975 { 976 acpi_status status; 977 int ret = 0; 978 int pkg_count, state_idx = 1, loop; 979 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 980 union acpi_object *lpi_data; 981 struct acpi_lpi_state *lpi_state; 982 983 status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); 984 if (ACPI_FAILURE(status)) { 985 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); 986 return -ENODEV; 987 } 988 989 lpi_data = buffer.pointer; 990 991 /* There must be at least 4 elements = 3 elements + 1 package */ 992 if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || 993 lpi_data->package.count < 4) { 994 pr_debug("not enough elements in _LPI\n"); 995 ret = -ENODATA; 996 goto end; 997 } 998 999 pkg_count = lpi_data->package.elements[2].integer.value; 1000 1001 /* Validate number of power states. */ 1002 if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { 1003 pr_debug("count given by _LPI is not valid\n"); 1004 ret = -ENODATA; 1005 goto end; 1006 } 1007 1008 lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); 1009 if (!lpi_state) { 1010 ret = -ENOMEM; 1011 goto end; 1012 } 1013 1014 info->size = pkg_count; 1015 info->entries = lpi_state; 1016 1017 /* LPI States start at index 3 */ 1018 for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { 1019 union acpi_object *element, *pkg_elem, *obj; 1020 1021 element = &lpi_data->package.elements[loop]; 1022 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) 1023 continue; 1024 1025 pkg_elem = element->package.elements; 1026 1027 obj = pkg_elem + 6; 1028 if (obj->type == ACPI_TYPE_BUFFER) { 1029 struct acpi_power_register *reg; 1030 1031 reg = (struct acpi_power_register *)obj->buffer.pointer; 1032 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 1033 reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) 1034 continue; 1035 1036 lpi_state->address = reg->address; 1037 lpi_state->entry_method = 1038 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? 1039 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; 1040 } else if (obj->type == ACPI_TYPE_INTEGER) { 1041 lpi_state->entry_method = ACPI_CSTATE_INTEGER; 1042 lpi_state->address = obj->integer.value; 1043 } else { 1044 continue; 1045 } 1046 1047 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ 1048 1049 obj = pkg_elem + 9; 1050 if (obj->type == ACPI_TYPE_STRING) 1051 strlcpy(lpi_state->desc, obj->string.pointer, 1052 ACPI_CX_DESC_LEN); 1053 1054 lpi_state->index = state_idx; 1055 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { 1056 pr_debug("No min. residency found, assuming 10 us\n"); 1057 lpi_state->min_residency = 10; 1058 } 1059 1060 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { 1061 pr_debug("No wakeup residency found, assuming 10 us\n"); 1062 lpi_state->wake_latency = 10; 1063 } 1064 1065 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) 1066 lpi_state->flags = 0; 1067 1068 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) 1069 lpi_state->arch_flags = 0; 1070 1071 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) 1072 lpi_state->res_cnt_freq = 1; 1073 1074 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) 1075 lpi_state->enable_parent_state = 0; 1076 } 1077 1078 acpi_handle_debug(handle, "Found %d power states\n", state_idx); 1079 end: 1080 kfree(buffer.pointer); 1081 return ret; 1082 } 1083 1084 /* 1085 * flat_state_cnt - the number of composite LPI states after the process of flattening 1086 */ 1087 static int flat_state_cnt; 1088 1089 /** 1090 * combine_lpi_states - combine local and parent LPI states to form a composite LPI state 1091 * 1092 * @local: local LPI state 1093 * @parent: parent LPI state 1094 * @result: composite LPI state 1095 */ 1096 static bool combine_lpi_states(struct acpi_lpi_state *local, 1097 struct acpi_lpi_state *parent, 1098 struct acpi_lpi_state *result) 1099 { 1100 if (parent->entry_method == ACPI_CSTATE_INTEGER) { 1101 if (!parent->address) /* 0 means autopromotable */ 1102 return false; 1103 result->address = local->address + parent->address; 1104 } else { 1105 result->address = parent->address; 1106 } 1107 1108 result->min_residency = max(local->min_residency, parent->min_residency); 1109 result->wake_latency = local->wake_latency + parent->wake_latency; 1110 result->enable_parent_state = parent->enable_parent_state; 1111 result->entry_method = local->entry_method; 1112 1113 result->flags = parent->flags; 1114 result->arch_flags = parent->arch_flags; 1115 result->index = parent->index; 1116 1117 strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); 1118 strlcat(result->desc, "+", ACPI_CX_DESC_LEN); 1119 strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); 1120 return true; 1121 } 1122 1123 #define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) 1124 1125 static void stash_composite_state(struct acpi_lpi_states_array *curr_level, 1126 struct acpi_lpi_state *t) 1127 { 1128 curr_level->composite_states[curr_level->composite_states_size++] = t; 1129 } 1130 1131 static int flatten_lpi_states(struct acpi_processor *pr, 1132 struct acpi_lpi_states_array *curr_level, 1133 struct acpi_lpi_states_array *prev_level) 1134 { 1135 int i, j, state_count = curr_level->size; 1136 struct acpi_lpi_state *p, *t = curr_level->entries; 1137 1138 curr_level->composite_states_size = 0; 1139 for (j = 0; j < state_count; j++, t++) { 1140 struct acpi_lpi_state *flpi; 1141 1142 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) 1143 continue; 1144 1145 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { 1146 pr_warn("Limiting number of LPI states to max (%d)\n", 1147 ACPI_PROCESSOR_MAX_POWER); 1148 pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 1149 break; 1150 } 1151 1152 flpi = &pr->power.lpi_states[flat_state_cnt]; 1153 1154 if (!prev_level) { /* leaf/processor node */ 1155 memcpy(flpi, t, sizeof(*t)); 1156 stash_composite_state(curr_level, flpi); 1157 flat_state_cnt++; 1158 continue; 1159 } 1160 1161 for (i = 0; i < prev_level->composite_states_size; i++) { 1162 p = prev_level->composite_states[i]; 1163 if (t->index <= p->enable_parent_state && 1164 combine_lpi_states(p, t, flpi)) { 1165 stash_composite_state(curr_level, flpi); 1166 flat_state_cnt++; 1167 flpi++; 1168 } 1169 } 1170 } 1171 1172 kfree(curr_level->entries); 1173 return 0; 1174 } 1175 1176 static int acpi_processor_get_lpi_info(struct acpi_processor *pr) 1177 { 1178 int ret, i; 1179 acpi_status status; 1180 acpi_handle handle = pr->handle, pr_ahandle; 1181 struct acpi_device *d = NULL; 1182 struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; 1183 1184 if (!osc_pc_lpi_support_confirmed) 1185 return -EOPNOTSUPP; 1186 1187 if (!acpi_has_method(handle, "_LPI")) 1188 return -EINVAL; 1189 1190 flat_state_cnt = 0; 1191 prev = &info[0]; 1192 curr = &info[1]; 1193 handle = pr->handle; 1194 ret = acpi_processor_evaluate_lpi(handle, prev); 1195 if (ret) 1196 return ret; 1197 flatten_lpi_states(pr, prev, NULL); 1198 1199 status = acpi_get_parent(handle, &pr_ahandle); 1200 while (ACPI_SUCCESS(status)) { 1201 acpi_bus_get_device(pr_ahandle, &d); 1202 handle = pr_ahandle; 1203 1204 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) 1205 break; 1206 1207 /* can be optional ? */ 1208 if (!acpi_has_method(handle, "_LPI")) 1209 break; 1210 1211 ret = acpi_processor_evaluate_lpi(handle, curr); 1212 if (ret) 1213 break; 1214 1215 /* flatten all the LPI states in this level of hierarchy */ 1216 flatten_lpi_states(pr, curr, prev); 1217 1218 tmp = prev, prev = curr, curr = tmp; 1219 1220 status = acpi_get_parent(handle, &pr_ahandle); 1221 } 1222 1223 pr->power.count = flat_state_cnt; 1224 /* reset the index after flattening */ 1225 for (i = 0; i < pr->power.count; i++) 1226 pr->power.lpi_states[i].index = i; 1227 1228 /* Tell driver that _LPI is supported. */ 1229 pr->flags.has_lpi = 1; 1230 pr->flags.power = 1; 1231 1232 return 0; 1233 } 1234 1235 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) 1236 { 1237 return -ENODEV; 1238 } 1239 1240 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 1241 { 1242 return -ENODEV; 1243 } 1244 1245 /** 1246 * acpi_idle_lpi_enter - enters an ACPI any LPI state 1247 * @dev: the target CPU 1248 * @drv: cpuidle driver containing cpuidle state info 1249 * @index: index of target state 1250 * 1251 * Return: 0 for success or negative value for error 1252 */ 1253 static int acpi_idle_lpi_enter(struct cpuidle_device *dev, 1254 struct cpuidle_driver *drv, int index) 1255 { 1256 struct acpi_processor *pr; 1257 struct acpi_lpi_state *lpi; 1258 1259 pr = __this_cpu_read(processors); 1260 1261 if (unlikely(!pr)) 1262 return -EINVAL; 1263 1264 lpi = &pr->power.lpi_states[index]; 1265 if (lpi->entry_method == ACPI_CSTATE_FFH) 1266 return acpi_processor_ffh_lpi_enter(lpi); 1267 1268 return -EINVAL; 1269 } 1270 1271 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 1272 { 1273 int i; 1274 struct acpi_lpi_state *lpi; 1275 struct cpuidle_state *state; 1276 struct cpuidle_driver *drv = &acpi_idle_driver; 1277 1278 if (!pr->flags.has_lpi) 1279 return -EOPNOTSUPP; 1280 1281 for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { 1282 lpi = &pr->power.lpi_states[i]; 1283 1284 state = &drv->states[i]; 1285 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); 1286 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); 1287 state->exit_latency = lpi->wake_latency; 1288 state->target_residency = lpi->min_residency; 1289 if (lpi->arch_flags) 1290 state->flags |= CPUIDLE_FLAG_TIMER_STOP; 1291 state->enter = acpi_idle_lpi_enter; 1292 drv->safe_state_index = i; 1293 } 1294 1295 drv->state_count = i; 1296 1297 return 0; 1298 } 1299 1300 /** 1301 * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle 1302 * global state data i.e. idle routines 1303 * 1304 * @pr: the ACPI processor 1305 */ 1306 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 1307 { 1308 int i; 1309 struct cpuidle_driver *drv = &acpi_idle_driver; 1310 1311 if (!pr->flags.power_setup_done || !pr->flags.power) 1312 return -EINVAL; 1313 1314 drv->safe_state_index = -1; 1315 for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { 1316 drv->states[i].name[0] = '\0'; 1317 drv->states[i].desc[0] = '\0'; 1318 } 1319 1320 if (pr->flags.has_lpi) 1321 return acpi_processor_setup_lpi_states(pr); 1322 1323 return acpi_processor_setup_cstates(pr); 1324 } 1325 1326 /** 1327 * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE 1328 * device i.e. per-cpu data 1329 * 1330 * @pr: the ACPI processor 1331 * @dev : the cpuidle device 1332 */ 1333 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, 1334 struct cpuidle_device *dev) 1335 { 1336 if (!pr->flags.power_setup_done || !pr->flags.power || !dev) 1337 return -EINVAL; 1338 1339 dev->cpu = pr->id; 1340 if (pr->flags.has_lpi) 1341 return acpi_processor_ffh_lpi_probe(pr->id); 1342 1343 return acpi_processor_setup_cpuidle_cx(pr, dev); 1344 } 1345 1346 static int acpi_processor_get_power_info(struct acpi_processor *pr) 1347 { 1348 int ret; 1349 1350 ret = acpi_processor_get_lpi_info(pr); 1351 if (ret) 1352 ret = acpi_processor_get_cstate_info(pr); 1353 1354 return ret; 1355 } 1356 1357 int acpi_processor_hotplug(struct acpi_processor *pr) 1358 { 1359 int ret = 0; 1360 struct cpuidle_device *dev; 1361 1362 if (disabled_by_idle_boot_param()) 1363 return 0; 1364 1365 if (!pr->flags.power_setup_done) 1366 return -ENODEV; 1367 1368 dev = per_cpu(acpi_cpuidle_device, pr->id); 1369 cpuidle_pause_and_lock(); 1370 cpuidle_disable_device(dev); 1371 ret = acpi_processor_get_power_info(pr); 1372 if (!ret && pr->flags.power) { 1373 acpi_processor_setup_cpuidle_dev(pr, dev); 1374 ret = cpuidle_enable_device(dev); 1375 } 1376 cpuidle_resume_and_unlock(); 1377 1378 return ret; 1379 } 1380 1381 int acpi_processor_power_state_has_changed(struct acpi_processor *pr) 1382 { 1383 int cpu; 1384 struct acpi_processor *_pr; 1385 struct cpuidle_device *dev; 1386 1387 if (disabled_by_idle_boot_param()) 1388 return 0; 1389 1390 if (!pr->flags.power_setup_done) 1391 return -ENODEV; 1392 1393 /* 1394 * FIXME: Design the ACPI notification to make it once per 1395 * system instead of once per-cpu. This condition is a hack 1396 * to make the code that updates C-States be called once. 1397 */ 1398 1399 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 1400 1401 /* Protect against cpu-hotplug */ 1402 get_online_cpus(); 1403 cpuidle_pause_and_lock(); 1404 1405 /* Disable all cpuidle devices */ 1406 for_each_online_cpu(cpu) { 1407 _pr = per_cpu(processors, cpu); 1408 if (!_pr || !_pr->flags.power_setup_done) 1409 continue; 1410 dev = per_cpu(acpi_cpuidle_device, cpu); 1411 cpuidle_disable_device(dev); 1412 } 1413 1414 /* Populate Updated C-state information */ 1415 acpi_processor_get_power_info(pr); 1416 acpi_processor_setup_cpuidle_states(pr); 1417 1418 /* Enable all cpuidle devices */ 1419 for_each_online_cpu(cpu) { 1420 _pr = per_cpu(processors, cpu); 1421 if (!_pr || !_pr->flags.power_setup_done) 1422 continue; 1423 acpi_processor_get_power_info(_pr); 1424 if (_pr->flags.power) { 1425 dev = per_cpu(acpi_cpuidle_device, cpu); 1426 acpi_processor_setup_cpuidle_dev(_pr, dev); 1427 cpuidle_enable_device(dev); 1428 } 1429 } 1430 cpuidle_resume_and_unlock(); 1431 put_online_cpus(); 1432 } 1433 1434 return 0; 1435 } 1436 1437 static int acpi_processor_registered; 1438 1439 int acpi_processor_power_init(struct acpi_processor *pr) 1440 { 1441 int retval; 1442 struct cpuidle_device *dev; 1443 1444 if (disabled_by_idle_boot_param()) 1445 return 0; 1446 1447 acpi_processor_cstate_first_run_checks(); 1448 1449 if (!acpi_processor_get_power_info(pr)) 1450 pr->flags.power_setup_done = 1; 1451 1452 /* 1453 * Install the idle handler if processor power management is supported. 1454 * Note that we use previously set idle handler will be used on 1455 * platforms that only support C1. 1456 */ 1457 if (pr->flags.power) { 1458 /* Register acpi_idle_driver if not already registered */ 1459 if (!acpi_processor_registered) { 1460 acpi_processor_setup_cpuidle_states(pr); 1461 retval = cpuidle_register_driver(&acpi_idle_driver); 1462 if (retval) 1463 return retval; 1464 pr_debug("%s registered with cpuidle\n", 1465 acpi_idle_driver.name); 1466 } 1467 1468 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1469 if (!dev) 1470 return -ENOMEM; 1471 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1472 1473 acpi_processor_setup_cpuidle_dev(pr, dev); 1474 1475 /* Register per-cpu cpuidle_device. Cpuidle driver 1476 * must already be registered before registering device 1477 */ 1478 retval = cpuidle_register_device(dev); 1479 if (retval) { 1480 if (acpi_processor_registered == 0) 1481 cpuidle_unregister_driver(&acpi_idle_driver); 1482 return retval; 1483 } 1484 acpi_processor_registered++; 1485 } 1486 return 0; 1487 } 1488 1489 int acpi_processor_power_exit(struct acpi_processor *pr) 1490 { 1491 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1492 1493 if (disabled_by_idle_boot_param()) 1494 return 0; 1495 1496 if (pr->flags.power) { 1497 cpuidle_unregister_device(dev); 1498 acpi_processor_registered--; 1499 if (acpi_processor_registered == 0) 1500 cpuidle_unregister_driver(&acpi_idle_driver); 1501 } 1502 1503 pr->flags.power_setup_done = 0; 1504 return 0; 1505 } 1506