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