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 * You should have received a copy of the GNU General Public License along 25 * with this program; if not, write to the Free Software Foundation, Inc., 26 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 27 * 28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 29 */ 30 31 #include <linux/module.h> 32 #include <linux/acpi.h> 33 #include <linux/dmi.h> 34 #include <linux/sched.h> /* need_resched() */ 35 #include <linux/clockchips.h> 36 #include <linux/cpuidle.h> 37 #include <linux/syscore_ops.h> 38 #include <acpi/processor.h> 39 40 /* 41 * Include the apic definitions for x86 to have the APIC timer related defines 42 * available also for UP (on SMP it gets magically included via linux/smp.h). 43 * asm/acpi.h is not an option, as it would require more include magic. Also 44 * creating an empty asm-ia64/apic.h would just trade pest vs. cholera. 45 */ 46 #ifdef CONFIG_X86 47 #include <asm/apic.h> 48 #endif 49 50 #define PREFIX "ACPI: " 51 52 #define ACPI_PROCESSOR_CLASS "processor" 53 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 54 ACPI_MODULE_NAME("processor_idle"); 55 56 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; 57 module_param(max_cstate, uint, 0000); 58 static unsigned int nocst __read_mostly; 59 module_param(nocst, uint, 0000); 60 static int bm_check_disable __read_mostly; 61 module_param(bm_check_disable, uint, 0000); 62 63 static unsigned int latency_factor __read_mostly = 2; 64 module_param(latency_factor, uint, 0644); 65 66 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device); 67 68 static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], 69 acpi_cstate); 70 71 static int disabled_by_idle_boot_param(void) 72 { 73 return boot_option_idle_override == IDLE_POLL || 74 boot_option_idle_override == IDLE_HALT; 75 } 76 77 /* 78 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3. 79 * For now disable this. Probably a bug somewhere else. 80 * 81 * To skip this limit, boot/load with a large max_cstate limit. 82 */ 83 static int set_max_cstate(const struct dmi_system_id *id) 84 { 85 if (max_cstate > ACPI_PROCESSOR_MAX_POWER) 86 return 0; 87 88 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate." 89 " Override with \"processor.max_cstate=%d\"\n", id->ident, 90 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1); 91 92 max_cstate = (long)id->driver_data; 93 94 return 0; 95 } 96 97 static struct dmi_system_id processor_power_dmi_table[] = { 98 { set_max_cstate, "Clevo 5600D", { 99 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"), 100 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")}, 101 (void *)2}, 102 { set_max_cstate, "Pavilion zv5000", { 103 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 104 DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")}, 105 (void *)1}, 106 { set_max_cstate, "Asus L8400B", { 107 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 108 DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")}, 109 (void *)1}, 110 {}, 111 }; 112 113 114 /* 115 * Callers should disable interrupts before the call and enable 116 * interrupts after return. 117 */ 118 static void acpi_safe_halt(void) 119 { 120 if (!tif_need_resched()) { 121 safe_halt(); 122 local_irq_disable(); 123 } 124 } 125 126 #ifdef ARCH_APICTIMER_STOPS_ON_C3 127 128 /* 129 * Some BIOS implementations switch to C3 in the published C2 state. 130 * This seems to be a common problem on AMD boxen, but other vendors 131 * are affected too. We pick the most conservative approach: we assume 132 * that the local APIC stops in both C2 and C3. 133 */ 134 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 135 struct acpi_processor_cx *cx) 136 { 137 struct acpi_processor_power *pwr = &pr->power; 138 u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2; 139 140 if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) 141 return; 142 143 if (amd_e400_c1e_detected) 144 type = ACPI_STATE_C1; 145 146 /* 147 * Check, if one of the previous states already marked the lapic 148 * unstable 149 */ 150 if (pwr->timer_broadcast_on_state < state) 151 return; 152 153 if (cx->type >= type) 154 pr->power.timer_broadcast_on_state = state; 155 } 156 157 static void __lapic_timer_propagate_broadcast(void *arg) 158 { 159 struct acpi_processor *pr = (struct acpi_processor *) arg; 160 unsigned long reason; 161 162 reason = pr->power.timer_broadcast_on_state < INT_MAX ? 163 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF; 164 165 clockevents_notify(reason, &pr->id); 166 } 167 168 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) 169 { 170 smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast, 171 (void *)pr, 1); 172 } 173 174 /* Power(C) State timer broadcast control */ 175 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 176 struct acpi_processor_cx *cx, 177 int broadcast) 178 { 179 int state = cx - pr->power.states; 180 181 if (state >= pr->power.timer_broadcast_on_state) { 182 unsigned long reason; 183 184 reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER : 185 CLOCK_EVT_NOTIFY_BROADCAST_EXIT; 186 clockevents_notify(reason, &pr->id); 187 } 188 } 189 190 #else 191 192 static void lapic_timer_check_state(int state, struct acpi_processor *pr, 193 struct acpi_processor_cx *cstate) { } 194 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } 195 static void lapic_timer_state_broadcast(struct acpi_processor *pr, 196 struct acpi_processor_cx *cx, 197 int broadcast) 198 { 199 } 200 201 #endif 202 203 #ifdef CONFIG_PM_SLEEP 204 static u32 saved_bm_rld; 205 206 static int acpi_processor_suspend(void) 207 { 208 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld); 209 return 0; 210 } 211 212 static void acpi_processor_resume(void) 213 { 214 u32 resumed_bm_rld = 0; 215 216 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld); 217 if (resumed_bm_rld == saved_bm_rld) 218 return; 219 220 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld); 221 } 222 223 static struct syscore_ops acpi_processor_syscore_ops = { 224 .suspend = acpi_processor_suspend, 225 .resume = acpi_processor_resume, 226 }; 227 228 void acpi_processor_syscore_init(void) 229 { 230 register_syscore_ops(&acpi_processor_syscore_ops); 231 } 232 233 void acpi_processor_syscore_exit(void) 234 { 235 unregister_syscore_ops(&acpi_processor_syscore_ops); 236 } 237 #endif /* CONFIG_PM_SLEEP */ 238 239 #if defined(CONFIG_X86) 240 static void tsc_check_state(int state) 241 { 242 switch (boot_cpu_data.x86_vendor) { 243 case X86_VENDOR_AMD: 244 case X86_VENDOR_INTEL: 245 /* 246 * AMD Fam10h TSC will tick in all 247 * C/P/S0/S1 states when this bit is set. 248 */ 249 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) 250 return; 251 252 /*FALL THROUGH*/ 253 default: 254 /* TSC could halt in idle, so notify users */ 255 if (state > ACPI_STATE_C1) 256 mark_tsc_unstable("TSC halts in idle"); 257 } 258 } 259 #else 260 static void tsc_check_state(int state) { return; } 261 #endif 262 263 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr) 264 { 265 266 if (!pr->pblk) 267 return -ENODEV; 268 269 /* if info is obtained from pblk/fadt, type equals state */ 270 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2; 271 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3; 272 273 #ifndef CONFIG_HOTPLUG_CPU 274 /* 275 * Check for P_LVL2_UP flag before entering C2 and above on 276 * an SMP system. 277 */ 278 if ((num_online_cpus() > 1) && 279 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) 280 return -ENODEV; 281 #endif 282 283 /* determine C2 and C3 address from pblk */ 284 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4; 285 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5; 286 287 /* determine latencies from FADT */ 288 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency; 289 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency; 290 291 /* 292 * FADT specified C2 latency must be less than or equal to 293 * 100 microseconds. 294 */ 295 if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) { 296 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 297 "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency)); 298 /* invalidate C2 */ 299 pr->power.states[ACPI_STATE_C2].address = 0; 300 } 301 302 /* 303 * FADT supplied C3 latency must be less than or equal to 304 * 1000 microseconds. 305 */ 306 if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) { 307 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 308 "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency)); 309 /* invalidate C3 */ 310 pr->power.states[ACPI_STATE_C3].address = 0; 311 } 312 313 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 314 "lvl2[0x%08x] lvl3[0x%08x]\n", 315 pr->power.states[ACPI_STATE_C2].address, 316 pr->power.states[ACPI_STATE_C3].address)); 317 318 return 0; 319 } 320 321 static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 322 { 323 if (!pr->power.states[ACPI_STATE_C1].valid) { 324 /* set the first C-State to C1 */ 325 /* all processors need to support C1 */ 326 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; 327 pr->power.states[ACPI_STATE_C1].valid = 1; 328 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; 329 } 330 /* the C0 state only exists as a filler in our array */ 331 pr->power.states[ACPI_STATE_C0].valid = 1; 332 return 0; 333 } 334 335 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 336 { 337 acpi_status status; 338 u64 count; 339 int current_count; 340 int i, ret = 0; 341 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 342 union acpi_object *cst; 343 344 345 if (nocst) 346 return -ENODEV; 347 348 current_count = 0; 349 350 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer); 351 if (ACPI_FAILURE(status)) { 352 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n")); 353 return -ENODEV; 354 } 355 356 cst = buffer.pointer; 357 358 /* There must be at least 2 elements */ 359 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) { 360 printk(KERN_ERR PREFIX "not enough elements in _CST\n"); 361 ret = -EFAULT; 362 goto end; 363 } 364 365 count = cst->package.elements[0].integer.value; 366 367 /* Validate number of power states. */ 368 if (count < 1 || count != cst->package.count - 1) { 369 printk(KERN_ERR PREFIX "count given by _CST is not valid\n"); 370 ret = -EFAULT; 371 goto end; 372 } 373 374 /* Tell driver that at least _CST is supported. */ 375 pr->flags.has_cst = 1; 376 377 for (i = 1; i <= count; i++) { 378 union acpi_object *element; 379 union acpi_object *obj; 380 struct acpi_power_register *reg; 381 struct acpi_processor_cx cx; 382 383 memset(&cx, 0, sizeof(cx)); 384 385 element = &(cst->package.elements[i]); 386 if (element->type != ACPI_TYPE_PACKAGE) 387 continue; 388 389 if (element->package.count != 4) 390 continue; 391 392 obj = &(element->package.elements[0]); 393 394 if (obj->type != ACPI_TYPE_BUFFER) 395 continue; 396 397 reg = (struct acpi_power_register *)obj->buffer.pointer; 398 399 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && 400 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) 401 continue; 402 403 /* There should be an easy way to extract an integer... */ 404 obj = &(element->package.elements[1]); 405 if (obj->type != ACPI_TYPE_INTEGER) 406 continue; 407 408 cx.type = obj->integer.value; 409 /* 410 * Some buggy BIOSes won't list C1 in _CST - 411 * Let acpi_processor_get_power_info_default() handle them later 412 */ 413 if (i == 1 && cx.type != ACPI_STATE_C1) 414 current_count++; 415 416 cx.address = reg->address; 417 cx.index = current_count + 1; 418 419 cx.entry_method = ACPI_CSTATE_SYSTEMIO; 420 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { 421 if (acpi_processor_ffh_cstate_probe 422 (pr->id, &cx, reg) == 0) { 423 cx.entry_method = ACPI_CSTATE_FFH; 424 } else if (cx.type == ACPI_STATE_C1) { 425 /* 426 * C1 is a special case where FIXED_HARDWARE 427 * can be handled in non-MWAIT way as well. 428 * In that case, save this _CST entry info. 429 * Otherwise, ignore this info and continue. 430 */ 431 cx.entry_method = ACPI_CSTATE_HALT; 432 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 433 } else { 434 continue; 435 } 436 if (cx.type == ACPI_STATE_C1 && 437 (boot_option_idle_override == IDLE_NOMWAIT)) { 438 /* 439 * In most cases the C1 space_id obtained from 440 * _CST object is FIXED_HARDWARE access mode. 441 * But when the option of idle=halt is added, 442 * the entry_method type should be changed from 443 * CSTATE_FFH to CSTATE_HALT. 444 * When the option of idle=nomwait is added, 445 * the C1 entry_method type should be 446 * CSTATE_HALT. 447 */ 448 cx.entry_method = ACPI_CSTATE_HALT; 449 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT"); 450 } 451 } else { 452 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x", 453 cx.address); 454 } 455 456 if (cx.type == ACPI_STATE_C1) { 457 cx.valid = 1; 458 } 459 460 obj = &(element->package.elements[2]); 461 if (obj->type != ACPI_TYPE_INTEGER) 462 continue; 463 464 cx.latency = obj->integer.value; 465 466 obj = &(element->package.elements[3]); 467 if (obj->type != ACPI_TYPE_INTEGER) 468 continue; 469 470 current_count++; 471 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx)); 472 473 /* 474 * We support total ACPI_PROCESSOR_MAX_POWER - 1 475 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1) 476 */ 477 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) { 478 printk(KERN_WARNING 479 "Limiting number of power states to max (%d)\n", 480 ACPI_PROCESSOR_MAX_POWER); 481 printk(KERN_WARNING 482 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); 483 break; 484 } 485 } 486 487 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", 488 current_count)); 489 490 /* Validate number of power states discovered */ 491 if (current_count < 2) 492 ret = -EFAULT; 493 494 end: 495 kfree(buffer.pointer); 496 497 return ret; 498 } 499 500 static void acpi_processor_power_verify_c3(struct acpi_processor *pr, 501 struct acpi_processor_cx *cx) 502 { 503 static int bm_check_flag = -1; 504 static int bm_control_flag = -1; 505 506 507 if (!cx->address) 508 return; 509 510 /* 511 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 512 * DMA transfers are used by any ISA device to avoid livelock. 513 * Note that we could disable Type-F DMA (as recommended by 514 * the erratum), but this is known to disrupt certain ISA 515 * devices thus we take the conservative approach. 516 */ 517 else if (errata.piix4.fdma) { 518 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 519 "C3 not supported on PIIX4 with Type-F DMA\n")); 520 return; 521 } 522 523 /* All the logic here assumes flags.bm_check is same across all CPUs */ 524 if (bm_check_flag == -1) { 525 /* Determine whether bm_check is needed based on CPU */ 526 acpi_processor_power_init_bm_check(&(pr->flags), pr->id); 527 bm_check_flag = pr->flags.bm_check; 528 bm_control_flag = pr->flags.bm_control; 529 } else { 530 pr->flags.bm_check = bm_check_flag; 531 pr->flags.bm_control = bm_control_flag; 532 } 533 534 if (pr->flags.bm_check) { 535 if (!pr->flags.bm_control) { 536 if (pr->flags.has_cst != 1) { 537 /* bus mastering control is necessary */ 538 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 539 "C3 support requires BM control\n")); 540 return; 541 } else { 542 /* Here we enter C3 without bus mastering */ 543 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 544 "C3 support without BM control\n")); 545 } 546 } 547 } else { 548 /* 549 * WBINVD should be set in fadt, for C3 state to be 550 * supported on when bm_check is not required. 551 */ 552 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) { 553 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 554 "Cache invalidation should work properly" 555 " for C3 to be enabled on SMP systems\n")); 556 return; 557 } 558 } 559 560 /* 561 * Otherwise we've met all of our C3 requirements. 562 * Normalize the C3 latency to expidite policy. Enable 563 * checking of bus mastering status (bm_check) so we can 564 * use this in our C3 policy 565 */ 566 cx->valid = 1; 567 568 /* 569 * On older chipsets, BM_RLD needs to be set 570 * in order for Bus Master activity to wake the 571 * system from C3. Newer chipsets handle DMA 572 * during C3 automatically and BM_RLD is a NOP. 573 * In either case, the proper way to 574 * handle BM_RLD is to set it and leave it set. 575 */ 576 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1); 577 578 return; 579 } 580 581 static int acpi_processor_power_verify(struct acpi_processor *pr) 582 { 583 unsigned int i; 584 unsigned int working = 0; 585 586 pr->power.timer_broadcast_on_state = INT_MAX; 587 588 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 589 struct acpi_processor_cx *cx = &pr->power.states[i]; 590 591 switch (cx->type) { 592 case ACPI_STATE_C1: 593 cx->valid = 1; 594 break; 595 596 case ACPI_STATE_C2: 597 if (!cx->address) 598 break; 599 cx->valid = 1; 600 break; 601 602 case ACPI_STATE_C3: 603 acpi_processor_power_verify_c3(pr, cx); 604 break; 605 } 606 if (!cx->valid) 607 continue; 608 609 lapic_timer_check_state(i, pr, cx); 610 tsc_check_state(cx->type); 611 working++; 612 } 613 614 lapic_timer_propagate_broadcast(pr); 615 616 return (working); 617 } 618 619 static int acpi_processor_get_power_info(struct acpi_processor *pr) 620 { 621 unsigned int i; 622 int result; 623 624 625 /* NOTE: the idle thread may not be running while calling 626 * this function */ 627 628 /* Zero initialize all the C-states info. */ 629 memset(pr->power.states, 0, sizeof(pr->power.states)); 630 631 result = acpi_processor_get_power_info_cst(pr); 632 if (result == -ENODEV) 633 result = acpi_processor_get_power_info_fadt(pr); 634 635 if (result) 636 return result; 637 638 acpi_processor_get_power_info_default(pr); 639 640 pr->power.count = acpi_processor_power_verify(pr); 641 642 /* 643 * if one state of type C2 or C3 is available, mark this 644 * CPU as being "idle manageable" 645 */ 646 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) { 647 if (pr->power.states[i].valid) { 648 pr->power.count = i; 649 if (pr->power.states[i].type >= ACPI_STATE_C2) 650 pr->flags.power = 1; 651 } 652 } 653 654 return 0; 655 } 656 657 /** 658 * acpi_idle_bm_check - checks if bus master activity was detected 659 */ 660 static int acpi_idle_bm_check(void) 661 { 662 u32 bm_status = 0; 663 664 if (bm_check_disable) 665 return 0; 666 667 acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); 668 if (bm_status) 669 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); 670 /* 671 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect 672 * the true state of bus mastering activity; forcing us to 673 * manually check the BMIDEA bit of each IDE channel. 674 */ 675 else if (errata.piix4.bmisx) { 676 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 677 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01)) 678 bm_status = 1; 679 } 680 return bm_status; 681 } 682 683 /** 684 * acpi_idle_do_entry - enter idle state using the appropriate method 685 * @cx: cstate data 686 * 687 * Caller disables interrupt before call and enables interrupt after return. 688 */ 689 static void acpi_idle_do_entry(struct acpi_processor_cx *cx) 690 { 691 if (cx->entry_method == ACPI_CSTATE_FFH) { 692 /* Call into architectural FFH based C-state */ 693 acpi_processor_ffh_cstate_enter(cx); 694 } else if (cx->entry_method == ACPI_CSTATE_HALT) { 695 acpi_safe_halt(); 696 } else { 697 /* IO port based C-state */ 698 inb(cx->address); 699 /* Dummy wait op - must do something useless after P_LVL2 read 700 because chipsets cannot guarantee that STPCLK# signal 701 gets asserted in time to freeze execution properly. */ 702 inl(acpi_gbl_FADT.xpm_timer_block.address); 703 } 704 } 705 706 /** 707 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 708 * @dev: the target CPU 709 * @index: the index of suggested state 710 */ 711 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 712 { 713 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 714 715 ACPI_FLUSH_CPU_CACHE(); 716 717 while (1) { 718 719 if (cx->entry_method == ACPI_CSTATE_HALT) 720 safe_halt(); 721 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 722 inb(cx->address); 723 /* See comment in acpi_idle_do_entry() */ 724 inl(acpi_gbl_FADT.xpm_timer_block.address); 725 } else 726 return -ENODEV; 727 } 728 729 /* Never reached */ 730 return 0; 731 } 732 733 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) 734 { 735 return IS_ENABLED(CONFIG_HOTPLUG_CPU) && num_online_cpus() > 1 && 736 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED) && 737 !pr->flags.has_cst; 738 } 739 740 static int c3_cpu_count; 741 static DEFINE_RAW_SPINLOCK(c3_lock); 742 743 /** 744 * acpi_idle_enter_bm - enters C3 with proper BM handling 745 * @pr: Target processor 746 * @cx: Target state context 747 */ 748 static void acpi_idle_enter_bm(struct acpi_processor *pr, 749 struct acpi_processor_cx *cx) 750 { 751 acpi_unlazy_tlb(smp_processor_id()); 752 753 /* 754 * Must be done before busmaster disable as we might need to 755 * access HPET ! 756 */ 757 lapic_timer_state_broadcast(pr, cx, 1); 758 759 /* 760 * disable bus master 761 * bm_check implies we need ARB_DIS 762 * bm_control implies whether we can do ARB_DIS 763 * 764 * That leaves a case where bm_check is set and bm_control is 765 * not set. In that case we cannot do much, we enter C3 766 * without doing anything. 767 */ 768 if (pr->flags.bm_control) { 769 raw_spin_lock(&c3_lock); 770 c3_cpu_count++; 771 /* Disable bus master arbitration when all CPUs are in C3 */ 772 if (c3_cpu_count == num_online_cpus()) 773 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 774 raw_spin_unlock(&c3_lock); 775 } 776 777 acpi_idle_do_entry(cx); 778 779 /* Re-enable bus master arbitration */ 780 if (pr->flags.bm_control) { 781 raw_spin_lock(&c3_lock); 782 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 783 c3_cpu_count--; 784 raw_spin_unlock(&c3_lock); 785 } 786 787 lapic_timer_state_broadcast(pr, cx, 0); 788 } 789 790 static int acpi_idle_enter(struct cpuidle_device *dev, 791 struct cpuidle_driver *drv, int index) 792 { 793 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 794 struct acpi_processor *pr; 795 796 pr = __this_cpu_read(processors); 797 if (unlikely(!pr)) 798 return -EINVAL; 799 800 if (cx->type != ACPI_STATE_C1) { 801 if (acpi_idle_fallback_to_c1(pr)) { 802 index = CPUIDLE_DRIVER_STATE_START; 803 cx = per_cpu(acpi_cstate[index], dev->cpu); 804 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { 805 if (cx->bm_sts_skip || !acpi_idle_bm_check()) { 806 acpi_idle_enter_bm(pr, cx); 807 return index; 808 } else if (drv->safe_state_index >= 0) { 809 index = drv->safe_state_index; 810 cx = per_cpu(acpi_cstate[index], dev->cpu); 811 } else { 812 acpi_safe_halt(); 813 return -EBUSY; 814 } 815 } 816 } 817 818 lapic_timer_state_broadcast(pr, cx, 1); 819 820 if (cx->type == ACPI_STATE_C3) 821 ACPI_FLUSH_CPU_CACHE(); 822 823 acpi_idle_do_entry(cx); 824 825 lapic_timer_state_broadcast(pr, cx, 0); 826 827 return index; 828 } 829 830 struct cpuidle_driver acpi_idle_driver = { 831 .name = "acpi_idle", 832 .owner = THIS_MODULE, 833 }; 834 835 /** 836 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE 837 * device i.e. per-cpu data 838 * 839 * @pr: the ACPI processor 840 * @dev : the cpuidle device 841 */ 842 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 843 struct cpuidle_device *dev) 844 { 845 int i, count = CPUIDLE_DRIVER_STATE_START; 846 struct acpi_processor_cx *cx; 847 848 if (!pr->flags.power_setup_done) 849 return -EINVAL; 850 851 if (pr->flags.power == 0) { 852 return -EINVAL; 853 } 854 855 if (!dev) 856 return -EINVAL; 857 858 dev->cpu = pr->id; 859 860 if (max_cstate == 0) 861 max_cstate = 1; 862 863 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 864 cx = &pr->power.states[i]; 865 866 if (!cx->valid) 867 continue; 868 869 per_cpu(acpi_cstate[count], dev->cpu) = cx; 870 871 count++; 872 if (count == CPUIDLE_STATE_MAX) 873 break; 874 } 875 876 if (!count) 877 return -EINVAL; 878 879 return 0; 880 } 881 882 /** 883 * acpi_processor_setup_cpuidle states- prepares and configures cpuidle 884 * global state data i.e. idle routines 885 * 886 * @pr: the ACPI processor 887 */ 888 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 889 { 890 int i, count = CPUIDLE_DRIVER_STATE_START; 891 struct acpi_processor_cx *cx; 892 struct cpuidle_state *state; 893 struct cpuidle_driver *drv = &acpi_idle_driver; 894 895 if (!pr->flags.power_setup_done) 896 return -EINVAL; 897 898 if (pr->flags.power == 0) 899 return -EINVAL; 900 901 drv->safe_state_index = -1; 902 for (i = 0; i < CPUIDLE_STATE_MAX; i++) { 903 drv->states[i].name[0] = '\0'; 904 drv->states[i].desc[0] = '\0'; 905 } 906 907 if (max_cstate == 0) 908 max_cstate = 1; 909 910 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { 911 cx = &pr->power.states[i]; 912 913 if (!cx->valid) 914 continue; 915 916 state = &drv->states[count]; 917 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); 918 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); 919 state->exit_latency = cx->latency; 920 state->target_residency = cx->latency * latency_factor; 921 state->enter = acpi_idle_enter; 922 923 state->flags = 0; 924 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { 925 state->enter_dead = acpi_idle_play_dead; 926 drv->safe_state_index = count; 927 } 928 929 count++; 930 if (count == CPUIDLE_STATE_MAX) 931 break; 932 } 933 934 drv->state_count = count; 935 936 if (!count) 937 return -EINVAL; 938 939 return 0; 940 } 941 942 int acpi_processor_hotplug(struct acpi_processor *pr) 943 { 944 int ret = 0; 945 struct cpuidle_device *dev; 946 947 if (disabled_by_idle_boot_param()) 948 return 0; 949 950 if (nocst) 951 return -ENODEV; 952 953 if (!pr->flags.power_setup_done) 954 return -ENODEV; 955 956 dev = per_cpu(acpi_cpuidle_device, pr->id); 957 cpuidle_pause_and_lock(); 958 cpuidle_disable_device(dev); 959 acpi_processor_get_power_info(pr); 960 if (pr->flags.power) { 961 acpi_processor_setup_cpuidle_cx(pr, dev); 962 ret = cpuidle_enable_device(dev); 963 } 964 cpuidle_resume_and_unlock(); 965 966 return ret; 967 } 968 969 int acpi_processor_cst_has_changed(struct acpi_processor *pr) 970 { 971 int cpu; 972 struct acpi_processor *_pr; 973 struct cpuidle_device *dev; 974 975 if (disabled_by_idle_boot_param()) 976 return 0; 977 978 if (nocst) 979 return -ENODEV; 980 981 if (!pr->flags.power_setup_done) 982 return -ENODEV; 983 984 /* 985 * FIXME: Design the ACPI notification to make it once per 986 * system instead of once per-cpu. This condition is a hack 987 * to make the code that updates C-States be called once. 988 */ 989 990 if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { 991 992 /* Protect against cpu-hotplug */ 993 get_online_cpus(); 994 cpuidle_pause_and_lock(); 995 996 /* Disable all cpuidle devices */ 997 for_each_online_cpu(cpu) { 998 _pr = per_cpu(processors, cpu); 999 if (!_pr || !_pr->flags.power_setup_done) 1000 continue; 1001 dev = per_cpu(acpi_cpuidle_device, cpu); 1002 cpuidle_disable_device(dev); 1003 } 1004 1005 /* Populate Updated C-state information */ 1006 acpi_processor_get_power_info(pr); 1007 acpi_processor_setup_cpuidle_states(pr); 1008 1009 /* Enable all cpuidle devices */ 1010 for_each_online_cpu(cpu) { 1011 _pr = per_cpu(processors, cpu); 1012 if (!_pr || !_pr->flags.power_setup_done) 1013 continue; 1014 acpi_processor_get_power_info(_pr); 1015 if (_pr->flags.power) { 1016 dev = per_cpu(acpi_cpuidle_device, cpu); 1017 acpi_processor_setup_cpuidle_cx(_pr, dev); 1018 cpuidle_enable_device(dev); 1019 } 1020 } 1021 cpuidle_resume_and_unlock(); 1022 put_online_cpus(); 1023 } 1024 1025 return 0; 1026 } 1027 1028 static int acpi_processor_registered; 1029 1030 int acpi_processor_power_init(struct acpi_processor *pr) 1031 { 1032 acpi_status status; 1033 int retval; 1034 struct cpuidle_device *dev; 1035 static int first_run; 1036 1037 if (disabled_by_idle_boot_param()) 1038 return 0; 1039 1040 if (!first_run) { 1041 dmi_check_system(processor_power_dmi_table); 1042 max_cstate = acpi_processor_cstate_check(max_cstate); 1043 if (max_cstate < ACPI_C_STATES_MAX) 1044 printk(KERN_NOTICE 1045 "ACPI: processor limited to max C-state %d\n", 1046 max_cstate); 1047 first_run++; 1048 } 1049 1050 if (acpi_gbl_FADT.cst_control && !nocst) { 1051 status = 1052 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8); 1053 if (ACPI_FAILURE(status)) { 1054 ACPI_EXCEPTION((AE_INFO, status, 1055 "Notifying BIOS of _CST ability failed")); 1056 } 1057 } 1058 1059 acpi_processor_get_power_info(pr); 1060 pr->flags.power_setup_done = 1; 1061 1062 /* 1063 * Install the idle handler if processor power management is supported. 1064 * Note that we use previously set idle handler will be used on 1065 * platforms that only support C1. 1066 */ 1067 if (pr->flags.power) { 1068 /* Register acpi_idle_driver if not already registered */ 1069 if (!acpi_processor_registered) { 1070 acpi_processor_setup_cpuidle_states(pr); 1071 retval = cpuidle_register_driver(&acpi_idle_driver); 1072 if (retval) 1073 return retval; 1074 printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n", 1075 acpi_idle_driver.name); 1076 } 1077 1078 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1079 if (!dev) 1080 return -ENOMEM; 1081 per_cpu(acpi_cpuidle_device, pr->id) = dev; 1082 1083 acpi_processor_setup_cpuidle_cx(pr, dev); 1084 1085 /* Register per-cpu cpuidle_device. Cpuidle driver 1086 * must already be registered before registering device 1087 */ 1088 retval = cpuidle_register_device(dev); 1089 if (retval) { 1090 if (acpi_processor_registered == 0) 1091 cpuidle_unregister_driver(&acpi_idle_driver); 1092 return retval; 1093 } 1094 acpi_processor_registered++; 1095 } 1096 return 0; 1097 } 1098 1099 int acpi_processor_power_exit(struct acpi_processor *pr) 1100 { 1101 struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id); 1102 1103 if (disabled_by_idle_boot_param()) 1104 return 0; 1105 1106 if (pr->flags.power) { 1107 cpuidle_unregister_device(dev); 1108 acpi_processor_registered--; 1109 if (acpi_processor_registered == 0) 1110 cpuidle_unregister_driver(&acpi_idle_driver); 1111 } 1112 1113 pr->flags.power_setup_done = 0; 1114 return 0; 1115 } 1116