1 /* 2 * acpi_processor.c - ACPI Processor Driver ($Revision: 71 $) 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 Dominik Brodowski <linux@brodo.de> 7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 8 * - Added processor hotplug support 9 * 10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or (at 15 * your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, but 18 * WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 * General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License along 23 * with this program; if not, write to the Free Software Foundation, Inc., 24 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 25 * 26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 27 * TBD: 28 * 1. Make # power states dynamic. 29 * 2. Support duty_cycle values that span bit 4. 30 * 3. Optimize by having scheduler determine business instead of 31 * having us try to calculate it here. 32 * 4. Need C1 timing -- must modify kernel (IRQ handler) to get this. 33 */ 34 35 #include <linux/kernel.h> 36 #include <linux/module.h> 37 #include <linux/init.h> 38 #include <linux/types.h> 39 #include <linux/pci.h> 40 #include <linux/pm.h> 41 #include <linux/cpufreq.h> 42 #include <linux/cpu.h> 43 #include <linux/dmi.h> 44 #include <linux/moduleparam.h> 45 #include <linux/cpuidle.h> 46 #include <linux/slab.h> 47 #include <linux/acpi.h> 48 #include <linux/memory_hotplug.h> 49 50 #include <asm/io.h> 51 #include <asm/cpu.h> 52 #include <asm/delay.h> 53 #include <asm/uaccess.h> 54 #include <asm/processor.h> 55 #include <asm/smp.h> 56 #include <asm/acpi.h> 57 58 #include <acpi/acpi_bus.h> 59 #include <acpi/acpi_drivers.h> 60 #include <acpi/processor.h> 61 62 #define PREFIX "ACPI: " 63 64 #define ACPI_PROCESSOR_CLASS "processor" 65 #define ACPI_PROCESSOR_DEVICE_NAME "Processor" 66 #define ACPI_PROCESSOR_FILE_INFO "info" 67 #define ACPI_PROCESSOR_FILE_THROTTLING "throttling" 68 #define ACPI_PROCESSOR_FILE_LIMIT "limit" 69 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 70 #define ACPI_PROCESSOR_NOTIFY_POWER 0x81 71 #define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 72 #define ACPI_PROCESSOR_DEVICE_HID "ACPI0007" 73 74 #define ACPI_PROCESSOR_LIMIT_USER 0 75 #define ACPI_PROCESSOR_LIMIT_THERMAL 1 76 77 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 78 ACPI_MODULE_NAME("processor_driver"); 79 80 MODULE_AUTHOR("Paul Diefenbaugh"); 81 MODULE_DESCRIPTION("ACPI Processor Driver"); 82 MODULE_LICENSE("GPL"); 83 84 static int acpi_processor_add(struct acpi_device *device); 85 static int acpi_processor_remove(struct acpi_device *device); 86 static void acpi_processor_notify(struct acpi_device *device, u32 event); 87 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr); 88 static int acpi_processor_handle_eject(struct acpi_processor *pr); 89 static int acpi_processor_start(struct acpi_processor *pr); 90 91 static const struct acpi_device_id processor_device_ids[] = { 92 {ACPI_PROCESSOR_OBJECT_HID, 0}, 93 {ACPI_PROCESSOR_DEVICE_HID, 0}, 94 {"", 0}, 95 }; 96 MODULE_DEVICE_TABLE(acpi, processor_device_ids); 97 98 static struct acpi_driver acpi_processor_driver = { 99 .name = "processor", 100 .class = ACPI_PROCESSOR_CLASS, 101 .ids = processor_device_ids, 102 .ops = { 103 .add = acpi_processor_add, 104 .remove = acpi_processor_remove, 105 .notify = acpi_processor_notify, 106 }, 107 }; 108 109 #define INSTALL_NOTIFY_HANDLER 1 110 #define UNINSTALL_NOTIFY_HANDLER 2 111 112 DEFINE_PER_CPU(struct acpi_processor *, processors); 113 EXPORT_PER_CPU_SYMBOL(processors); 114 115 struct acpi_processor_errata errata __read_mostly; 116 117 /* -------------------------------------------------------------------------- 118 Errata Handling 119 -------------------------------------------------------------------------- */ 120 121 static int acpi_processor_errata_piix4(struct pci_dev *dev) 122 { 123 u8 value1 = 0; 124 u8 value2 = 0; 125 126 127 if (!dev) 128 return -EINVAL; 129 130 /* 131 * Note that 'dev' references the PIIX4 ACPI Controller. 132 */ 133 134 switch (dev->revision) { 135 case 0: 136 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n")); 137 break; 138 case 1: 139 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n")); 140 break; 141 case 2: 142 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n")); 143 break; 144 case 3: 145 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n")); 146 break; 147 default: 148 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n")); 149 break; 150 } 151 152 switch (dev->revision) { 153 154 case 0: /* PIIX4 A-step */ 155 case 1: /* PIIX4 B-step */ 156 /* 157 * See specification changes #13 ("Manual Throttle Duty Cycle") 158 * and #14 ("Enabling and Disabling Manual Throttle"), plus 159 * erratum #5 ("STPCLK# Deassertion Time") from the January 160 * 2002 PIIX4 specification update. Applies to only older 161 * PIIX4 models. 162 */ 163 errata.piix4.throttle = 1; 164 165 case 2: /* PIIX4E */ 166 case 3: /* PIIX4M */ 167 /* 168 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA 169 * Livelock") from the January 2002 PIIX4 specification update. 170 * Applies to all PIIX4 models. 171 */ 172 173 /* 174 * BM-IDE 175 * ------ 176 * Find the PIIX4 IDE Controller and get the Bus Master IDE 177 * Status register address. We'll use this later to read 178 * each IDE controller's DMA status to make sure we catch all 179 * DMA activity. 180 */ 181 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 182 PCI_DEVICE_ID_INTEL_82371AB, 183 PCI_ANY_ID, PCI_ANY_ID, NULL); 184 if (dev) { 185 errata.piix4.bmisx = pci_resource_start(dev, 4); 186 pci_dev_put(dev); 187 } 188 189 /* 190 * Type-F DMA 191 * ---------- 192 * Find the PIIX4 ISA Controller and read the Motherboard 193 * DMA controller's status to see if Type-F (Fast) DMA mode 194 * is enabled (bit 7) on either channel. Note that we'll 195 * disable C3 support if this is enabled, as some legacy 196 * devices won't operate well if fast DMA is disabled. 197 */ 198 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 199 PCI_DEVICE_ID_INTEL_82371AB_0, 200 PCI_ANY_ID, PCI_ANY_ID, NULL); 201 if (dev) { 202 pci_read_config_byte(dev, 0x76, &value1); 203 pci_read_config_byte(dev, 0x77, &value2); 204 if ((value1 & 0x80) || (value2 & 0x80)) 205 errata.piix4.fdma = 1; 206 pci_dev_put(dev); 207 } 208 209 break; 210 } 211 212 if (errata.piix4.bmisx) 213 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 214 "Bus master activity detection (BM-IDE) erratum enabled\n")); 215 if (errata.piix4.fdma) 216 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 217 "Type-F DMA livelock erratum (C3 disabled)\n")); 218 219 return 0; 220 } 221 222 static int acpi_processor_errata(struct acpi_processor *pr) 223 { 224 int result = 0; 225 struct pci_dev *dev = NULL; 226 227 228 if (!pr) 229 return -EINVAL; 230 231 /* 232 * PIIX4 233 */ 234 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 235 PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID, 236 PCI_ANY_ID, NULL); 237 if (dev) { 238 result = acpi_processor_errata_piix4(dev); 239 pci_dev_put(dev); 240 } 241 242 return result; 243 } 244 245 /* -------------------------------------------------------------------------- 246 Driver Interface 247 -------------------------------------------------------------------------- */ 248 249 static int acpi_processor_get_info(struct acpi_device *device) 250 { 251 acpi_status status = 0; 252 union acpi_object object = { 0 }; 253 struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; 254 struct acpi_processor *pr; 255 int cpu_index, device_declaration = 0; 256 static int cpu0_initialized; 257 258 pr = acpi_driver_data(device); 259 if (!pr) 260 return -EINVAL; 261 262 if (num_online_cpus() > 1) 263 errata.smp = TRUE; 264 265 acpi_processor_errata(pr); 266 267 /* 268 * Check to see if we have bus mastering arbitration control. This 269 * is required for proper C3 usage (to maintain cache coherency). 270 */ 271 if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) { 272 pr->flags.bm_control = 1; 273 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 274 "Bus mastering arbitration control present\n")); 275 } else 276 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 277 "No bus mastering arbitration control\n")); 278 279 if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) { 280 /* Declared with "Processor" statement; match ProcessorID */ 281 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer); 282 if (ACPI_FAILURE(status)) { 283 dev_err(&device->dev, 284 "Failed to evaluate processor object (0x%x)\n", 285 status); 286 return -ENODEV; 287 } 288 289 /* 290 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP. 291 * >>> 'acpi_get_processor_id(acpi_id, &id)' in 292 * arch/xxx/acpi.c 293 */ 294 pr->acpi_id = object.processor.proc_id; 295 } else { 296 /* 297 * Declared with "Device" statement; match _UID. 298 * Note that we don't handle string _UIDs yet. 299 */ 300 unsigned long long value; 301 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID, 302 NULL, &value); 303 if (ACPI_FAILURE(status)) { 304 dev_err(&device->dev, 305 "Failed to evaluate processor _UID (0x%x)\n", 306 status); 307 return -ENODEV; 308 } 309 device_declaration = 1; 310 pr->acpi_id = value; 311 } 312 cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id); 313 314 /* Handle UP system running SMP kernel, with no LAPIC in MADT */ 315 if (!cpu0_initialized && (cpu_index == -1) && 316 (num_online_cpus() == 1)) { 317 cpu_index = 0; 318 } 319 320 cpu0_initialized = 1; 321 322 pr->id = cpu_index; 323 324 /* 325 * Extra Processor objects may be enumerated on MP systems with 326 * less than the max # of CPUs. They should be ignored _iff 327 * they are physically not present. 328 */ 329 if (pr->id == -1) { 330 if (ACPI_FAILURE(acpi_processor_hotadd_init(pr))) 331 return -ENODEV; 332 } 333 /* 334 * On some boxes several processors use the same processor bus id. 335 * But they are located in different scope. For example: 336 * \_SB.SCK0.CPU0 337 * \_SB.SCK1.CPU0 338 * Rename the processor device bus id. And the new bus id will be 339 * generated as the following format: 340 * CPU+CPU ID. 341 */ 342 sprintf(acpi_device_bid(device), "CPU%X", pr->id); 343 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id, 344 pr->acpi_id)); 345 346 if (!object.processor.pblk_address) 347 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n")); 348 else if (object.processor.pblk_length != 6) 349 dev_err(&device->dev, "Invalid PBLK length [%d]\n", 350 object.processor.pblk_length); 351 else { 352 pr->throttling.address = object.processor.pblk_address; 353 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset; 354 pr->throttling.duty_width = acpi_gbl_FADT.duty_width; 355 356 pr->pblk = object.processor.pblk_address; 357 358 /* 359 * We don't care about error returns - we just try to mark 360 * these reserved so that nobody else is confused into thinking 361 * that this region might be unused.. 362 * 363 * (In particular, allocating the IO range for Cardbus) 364 */ 365 request_region(pr->throttling.address, 6, "ACPI CPU throttle"); 366 } 367 368 /* 369 * If ACPI describes a slot number for this CPU, we can use it 370 * ensure we get the right value in the "physical id" field 371 * of /proc/cpuinfo 372 */ 373 status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer); 374 if (ACPI_SUCCESS(status)) 375 arch_fix_phys_package_id(pr->id, object.integer.value); 376 377 return 0; 378 } 379 380 static DEFINE_PER_CPU(void *, processor_device_array); 381 382 static void acpi_processor_notify(struct acpi_device *device, u32 event) 383 { 384 struct acpi_processor *pr = acpi_driver_data(device); 385 int saved; 386 387 if (!pr) 388 return; 389 390 switch (event) { 391 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE: 392 saved = pr->performance_platform_limit; 393 acpi_processor_ppc_has_changed(pr, 1); 394 if (saved == pr->performance_platform_limit) 395 break; 396 acpi_bus_generate_proc_event(device, event, 397 pr->performance_platform_limit); 398 acpi_bus_generate_netlink_event(device->pnp.device_class, 399 dev_name(&device->dev), event, 400 pr->performance_platform_limit); 401 break; 402 case ACPI_PROCESSOR_NOTIFY_POWER: 403 acpi_processor_cst_has_changed(pr); 404 acpi_bus_generate_proc_event(device, event, 0); 405 acpi_bus_generate_netlink_event(device->pnp.device_class, 406 dev_name(&device->dev), event, 0); 407 break; 408 case ACPI_PROCESSOR_NOTIFY_THROTTLING: 409 acpi_processor_tstate_has_changed(pr); 410 acpi_bus_generate_proc_event(device, event, 0); 411 acpi_bus_generate_netlink_event(device->pnp.device_class, 412 dev_name(&device->dev), event, 0); 413 break; 414 default: 415 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 416 "Unsupported event [0x%x]\n", event)); 417 break; 418 } 419 420 return; 421 } 422 423 static int acpi_cpu_soft_notify(struct notifier_block *nfb, 424 unsigned long action, void *hcpu) 425 { 426 unsigned int cpu = (unsigned long)hcpu; 427 struct acpi_processor *pr = per_cpu(processors, cpu); 428 429 if (action == CPU_ONLINE && pr) { 430 /* CPU got physically hotplugged and onlined the first time: 431 * Initialize missing things 432 */ 433 if (pr->flags.need_hotplug_init) { 434 pr_info("Will online and init hotplugged CPU: %d\n", 435 pr->id); 436 WARN(acpi_processor_start(pr), "Failed to start CPU:" 437 " %d\n", pr->id); 438 pr->flags.need_hotplug_init = 0; 439 /* Normal CPU soft online event */ 440 } else { 441 acpi_processor_ppc_has_changed(pr, 0); 442 acpi_processor_hotplug(pr); 443 acpi_processor_reevaluate_tstate(pr, action); 444 acpi_processor_tstate_has_changed(pr); 445 } 446 } 447 if (action == CPU_DEAD && pr) { 448 /* invalidate the flag.throttling after one CPU is offline */ 449 acpi_processor_reevaluate_tstate(pr, action); 450 } 451 return NOTIFY_OK; 452 } 453 454 static struct notifier_block acpi_cpu_notifier = 455 { 456 .notifier_call = acpi_cpu_soft_notify, 457 }; 458 459 /* 460 * acpi_processor_start() is called by the cpu_hotplug_notifier func: 461 * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the 462 * root cause seem to be that acpi_processor_uninstall_hotplug_notify() 463 * is in the module_exit (__exit) func. Allowing acpi_processor_start() 464 * to not be in __cpuinit section, but being called from __cpuinit funcs 465 * via __ref looks like the right thing to do here. 466 */ 467 static __ref int acpi_processor_start(struct acpi_processor *pr) 468 { 469 struct acpi_device *device = per_cpu(processor_device_array, pr->id); 470 int result = 0; 471 472 #ifdef CONFIG_CPU_FREQ 473 acpi_processor_ppc_has_changed(pr, 0); 474 acpi_processor_load_module(pr); 475 #endif 476 acpi_processor_get_throttling_info(pr); 477 acpi_processor_get_limit_info(pr); 478 479 if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) 480 acpi_processor_power_init(pr); 481 482 pr->cdev = thermal_cooling_device_register("Processor", device, 483 &processor_cooling_ops); 484 if (IS_ERR(pr->cdev)) { 485 result = PTR_ERR(pr->cdev); 486 goto err_power_exit; 487 } 488 489 dev_dbg(&device->dev, "registered as cooling_device%d\n", 490 pr->cdev->id); 491 492 result = sysfs_create_link(&device->dev.kobj, 493 &pr->cdev->device.kobj, 494 "thermal_cooling"); 495 if (result) { 496 dev_err(&device->dev, 497 "Failed to create sysfs link 'thermal_cooling'\n"); 498 goto err_thermal_unregister; 499 } 500 result = sysfs_create_link(&pr->cdev->device.kobj, 501 &device->dev.kobj, 502 "device"); 503 if (result) { 504 dev_err(&pr->cdev->device, 505 "Failed to create sysfs link 'device'\n"); 506 goto err_remove_sysfs_thermal; 507 } 508 509 return 0; 510 511 err_remove_sysfs_thermal: 512 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 513 err_thermal_unregister: 514 thermal_cooling_device_unregister(pr->cdev); 515 err_power_exit: 516 acpi_processor_power_exit(pr); 517 518 return result; 519 } 520 521 /* 522 * Do not put anything in here which needs the core to be online. 523 * For example MSR access or setting up things which check for cpuinfo_x86 524 * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. 525 * Such things have to be put in and set up above in acpi_processor_start() 526 */ 527 static int __cpuinit acpi_processor_add(struct acpi_device *device) 528 { 529 struct acpi_processor *pr = NULL; 530 int result = 0; 531 struct device *dev; 532 533 pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); 534 if (!pr) 535 return -ENOMEM; 536 537 if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) { 538 result = -ENOMEM; 539 goto err_free_pr; 540 } 541 542 pr->handle = device->handle; 543 strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME); 544 strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS); 545 device->driver_data = pr; 546 547 result = acpi_processor_get_info(device); 548 if (result) { 549 /* Processor is physically not present */ 550 return 0; 551 } 552 553 #ifdef CONFIG_SMP 554 if (pr->id >= setup_max_cpus && pr->id != 0) 555 return 0; 556 #endif 557 558 BUG_ON(pr->id >= nr_cpu_ids); 559 560 /* 561 * Buggy BIOS check 562 * ACPI id of processors can be reported wrongly by the BIOS. 563 * Don't trust it blindly 564 */ 565 if (per_cpu(processor_device_array, pr->id) != NULL && 566 per_cpu(processor_device_array, pr->id) != device) { 567 dev_warn(&device->dev, 568 "BIOS reported wrong ACPI id %d for the processor\n", 569 pr->id); 570 result = -ENODEV; 571 goto err_free_cpumask; 572 } 573 per_cpu(processor_device_array, pr->id) = device; 574 575 per_cpu(processors, pr->id) = pr; 576 577 dev = get_cpu_device(pr->id); 578 if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) { 579 result = -EFAULT; 580 goto err_clear_processor; 581 } 582 583 /* 584 * Do not start hotplugged CPUs now, but when they 585 * are onlined the first time 586 */ 587 if (pr->flags.need_hotplug_init) 588 return 0; 589 590 result = acpi_processor_start(pr); 591 if (result) 592 goto err_remove_sysfs; 593 594 return 0; 595 596 err_remove_sysfs: 597 sysfs_remove_link(&device->dev.kobj, "sysdev"); 598 err_clear_processor: 599 /* 600 * processor_device_array is not cleared to allow checks for buggy BIOS 601 */ 602 per_cpu(processors, pr->id) = NULL; 603 err_free_cpumask: 604 free_cpumask_var(pr->throttling.shared_cpu_map); 605 err_free_pr: 606 kfree(pr); 607 return result; 608 } 609 610 static int acpi_processor_remove(struct acpi_device *device) 611 { 612 struct acpi_processor *pr = NULL; 613 614 615 if (!device || !acpi_driver_data(device)) 616 return -EINVAL; 617 618 pr = acpi_driver_data(device); 619 620 if (pr->id >= nr_cpu_ids) 621 goto free; 622 623 if (device->removal_type == ACPI_BUS_REMOVAL_EJECT) { 624 if (acpi_processor_handle_eject(pr)) 625 return -EINVAL; 626 } 627 628 acpi_processor_power_exit(pr); 629 630 sysfs_remove_link(&device->dev.kobj, "sysdev"); 631 632 if (pr->cdev) { 633 sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); 634 sysfs_remove_link(&pr->cdev->device.kobj, "device"); 635 thermal_cooling_device_unregister(pr->cdev); 636 pr->cdev = NULL; 637 } 638 639 per_cpu(processors, pr->id) = NULL; 640 per_cpu(processor_device_array, pr->id) = NULL; 641 try_offline_node(cpu_to_node(pr->id)); 642 643 free: 644 free_cpumask_var(pr->throttling.shared_cpu_map); 645 kfree(pr); 646 647 return 0; 648 } 649 650 #ifdef CONFIG_ACPI_HOTPLUG_CPU 651 /**************************************************************************** 652 * Acpi processor hotplug support * 653 ****************************************************************************/ 654 655 static int is_processor_present(acpi_handle handle) 656 { 657 acpi_status status; 658 unsigned long long sta = 0; 659 660 661 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); 662 663 if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT)) 664 return 1; 665 666 /* 667 * _STA is mandatory for a processor that supports hot plug 668 */ 669 if (status == AE_NOT_FOUND) 670 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 671 "Processor does not support hot plug\n")); 672 else 673 ACPI_EXCEPTION((AE_INFO, status, 674 "Processor Device is not present")); 675 return 0; 676 } 677 678 static void acpi_processor_hotplug_notify(acpi_handle handle, 679 u32 event, void *data) 680 { 681 struct acpi_device *device = NULL; 682 struct acpi_eject_event *ej_event = NULL; 683 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ 684 acpi_status status; 685 int result; 686 687 acpi_scan_lock_acquire(); 688 689 switch (event) { 690 case ACPI_NOTIFY_BUS_CHECK: 691 case ACPI_NOTIFY_DEVICE_CHECK: 692 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 693 "Processor driver received %s event\n", 694 (event == ACPI_NOTIFY_BUS_CHECK) ? 695 "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK")); 696 697 if (!is_processor_present(handle)) 698 break; 699 700 if (!acpi_bus_get_device(handle, &device)) 701 break; 702 703 result = acpi_bus_scan(handle); 704 if (result) { 705 acpi_handle_err(handle, "Unable to add the device\n"); 706 break; 707 } 708 result = acpi_bus_get_device(handle, &device); 709 if (result) { 710 acpi_handle_err(handle, "Missing device object\n"); 711 break; 712 } 713 ost_code = ACPI_OST_SC_SUCCESS; 714 break; 715 716 case ACPI_NOTIFY_EJECT_REQUEST: 717 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 718 "received ACPI_NOTIFY_EJECT_REQUEST\n")); 719 720 if (acpi_bus_get_device(handle, &device)) { 721 acpi_handle_err(handle, 722 "Device don't exist, dropping EJECT\n"); 723 break; 724 } 725 if (!acpi_driver_data(device)) { 726 acpi_handle_err(handle, 727 "Driver data is NULL, dropping EJECT\n"); 728 break; 729 } 730 731 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL); 732 if (!ej_event) { 733 acpi_handle_err(handle, "No memory, dropping EJECT\n"); 734 break; 735 } 736 737 get_device(&device->dev); 738 ej_event->device = device; 739 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST; 740 /* The eject is carried out asynchronously. */ 741 status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, 742 ej_event); 743 if (ACPI_FAILURE(status)) { 744 put_device(&device->dev); 745 kfree(ej_event); 746 break; 747 } 748 goto out; 749 750 default: 751 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 752 "Unsupported event [0x%x]\n", event)); 753 754 /* non-hotplug event; possibly handled by other handler */ 755 goto out; 756 } 757 758 /* Inform firmware that the hotplug operation has completed */ 759 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL); 760 761 out: 762 acpi_scan_lock_release(); 763 } 764 765 static acpi_status is_processor_device(acpi_handle handle) 766 { 767 struct acpi_device_info *info; 768 char *hid; 769 acpi_status status; 770 771 status = acpi_get_object_info(handle, &info); 772 if (ACPI_FAILURE(status)) 773 return status; 774 775 if (info->type == ACPI_TYPE_PROCESSOR) { 776 kfree(info); 777 return AE_OK; /* found a processor object */ 778 } 779 780 if (!(info->valid & ACPI_VALID_HID)) { 781 kfree(info); 782 return AE_ERROR; 783 } 784 785 hid = info->hardware_id.string; 786 if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) { 787 kfree(info); 788 return AE_ERROR; 789 } 790 791 kfree(info); 792 return AE_OK; /* found a processor device object */ 793 } 794 795 static acpi_status 796 processor_walk_namespace_cb(acpi_handle handle, 797 u32 lvl, void *context, void **rv) 798 { 799 acpi_status status; 800 int *action = context; 801 802 status = is_processor_device(handle); 803 if (ACPI_FAILURE(status)) 804 return AE_OK; /* not a processor; continue to walk */ 805 806 switch (*action) { 807 case INSTALL_NOTIFY_HANDLER: 808 acpi_install_notify_handler(handle, 809 ACPI_SYSTEM_NOTIFY, 810 acpi_processor_hotplug_notify, 811 NULL); 812 break; 813 case UNINSTALL_NOTIFY_HANDLER: 814 acpi_remove_notify_handler(handle, 815 ACPI_SYSTEM_NOTIFY, 816 acpi_processor_hotplug_notify); 817 break; 818 default: 819 break; 820 } 821 822 /* found a processor; skip walking underneath */ 823 return AE_CTRL_DEPTH; 824 } 825 826 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr) 827 { 828 acpi_handle handle = pr->handle; 829 830 if (!is_processor_present(handle)) { 831 return AE_ERROR; 832 } 833 834 if (acpi_map_lsapic(handle, &pr->id)) 835 return AE_ERROR; 836 837 if (arch_register_cpu(pr->id)) { 838 acpi_unmap_lsapic(pr->id); 839 return AE_ERROR; 840 } 841 842 /* CPU got hot-plugged, but cpu_data is not initialized yet 843 * Set flag to delay cpu_idle/throttling initialization 844 * in: 845 * acpi_processor_add() 846 * acpi_processor_get_info() 847 * and do it when the CPU gets online the first time 848 * TBD: Cleanup above functions and try to do this more elegant. 849 */ 850 pr_info("CPU %d got hotplugged\n", pr->id); 851 pr->flags.need_hotplug_init = 1; 852 853 return AE_OK; 854 } 855 856 static int acpi_processor_handle_eject(struct acpi_processor *pr) 857 { 858 if (cpu_online(pr->id)) 859 cpu_down(pr->id); 860 861 get_online_cpus(); 862 /* 863 * The cpu might become online again at this point. So we check whether 864 * the cpu has been onlined or not. If the cpu became online, it means 865 * that someone wants to use the cpu. So acpi_processor_handle_eject() 866 * returns -EAGAIN. 867 */ 868 if (unlikely(cpu_online(pr->id))) { 869 put_online_cpus(); 870 pr_warn("Failed to remove CPU %d, because other task " 871 "brought the CPU back online\n", pr->id); 872 return -EAGAIN; 873 } 874 arch_unregister_cpu(pr->id); 875 acpi_unmap_lsapic(pr->id); 876 put_online_cpus(); 877 return (0); 878 } 879 #else 880 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr) 881 { 882 return AE_ERROR; 883 } 884 static int acpi_processor_handle_eject(struct acpi_processor *pr) 885 { 886 return (-EINVAL); 887 } 888 #endif 889 890 static 891 void acpi_processor_install_hotplug_notify(void) 892 { 893 #ifdef CONFIG_ACPI_HOTPLUG_CPU 894 int action = INSTALL_NOTIFY_HANDLER; 895 acpi_walk_namespace(ACPI_TYPE_ANY, 896 ACPI_ROOT_OBJECT, 897 ACPI_UINT32_MAX, 898 processor_walk_namespace_cb, NULL, &action, NULL); 899 #endif 900 register_hotcpu_notifier(&acpi_cpu_notifier); 901 } 902 903 static 904 void acpi_processor_uninstall_hotplug_notify(void) 905 { 906 #ifdef CONFIG_ACPI_HOTPLUG_CPU 907 int action = UNINSTALL_NOTIFY_HANDLER; 908 acpi_walk_namespace(ACPI_TYPE_ANY, 909 ACPI_ROOT_OBJECT, 910 ACPI_UINT32_MAX, 911 processor_walk_namespace_cb, NULL, &action, NULL); 912 #endif 913 unregister_hotcpu_notifier(&acpi_cpu_notifier); 914 } 915 916 /* 917 * We keep the driver loaded even when ACPI is not running. 918 * This is needed for the powernow-k8 driver, that works even without 919 * ACPI, but needs symbols from this driver 920 */ 921 922 static int __init acpi_processor_init(void) 923 { 924 int result = 0; 925 926 if (acpi_disabled) 927 return 0; 928 929 result = acpi_bus_register_driver(&acpi_processor_driver); 930 if (result < 0) 931 return result; 932 933 acpi_processor_syscore_init(); 934 935 acpi_processor_install_hotplug_notify(); 936 937 acpi_thermal_cpufreq_init(); 938 939 acpi_processor_ppc_init(); 940 941 acpi_processor_throttling_init(); 942 943 return 0; 944 } 945 946 static void __exit acpi_processor_exit(void) 947 { 948 if (acpi_disabled) 949 return; 950 951 acpi_processor_ppc_exit(); 952 953 acpi_thermal_cpufreq_exit(); 954 955 acpi_processor_uninstall_hotplug_notify(); 956 957 acpi_processor_syscore_exit(); 958 959 acpi_bus_unregister_driver(&acpi_processor_driver); 960 961 return; 962 } 963 964 module_init(acpi_processor_init); 965 module_exit(acpi_processor_exit); 966 967 MODULE_ALIAS("processor"); 968