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 
48 #include <asm/io.h>
49 #include <asm/system.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 
72 #define ACPI_PROCESSOR_LIMIT_USER	0
73 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
74 
75 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
76 ACPI_MODULE_NAME("processor_driver");
77 
78 MODULE_AUTHOR("Paul Diefenbaugh");
79 MODULE_DESCRIPTION("ACPI Processor Driver");
80 MODULE_LICENSE("GPL");
81 
82 static int acpi_processor_add(struct acpi_device *device);
83 static int acpi_processor_remove(struct acpi_device *device, int type);
84 static void acpi_processor_notify(struct acpi_device *device, u32 event);
85 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
86 static int acpi_processor_handle_eject(struct acpi_processor *pr);
87 
88 
89 static const struct acpi_device_id processor_device_ids[] = {
90 	{ACPI_PROCESSOR_OBJECT_HID, 0},
91 	{"ACPI0007", 0},
92 	{"", 0},
93 };
94 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
95 
96 static struct acpi_driver acpi_processor_driver = {
97 	.name = "processor",
98 	.class = ACPI_PROCESSOR_CLASS,
99 	.ids = processor_device_ids,
100 	.ops = {
101 		.add = acpi_processor_add,
102 		.remove = acpi_processor_remove,
103 		.suspend = acpi_processor_suspend,
104 		.resume = acpi_processor_resume,
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 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
284 			return -ENODEV;
285 		}
286 
287 		/*
288 		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
289 		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
290 		 *      arch/xxx/acpi.c
291 		 */
292 		pr->acpi_id = object.processor.proc_id;
293 	} else {
294 		/*
295 		 * Declared with "Device" statement; match _UID.
296 		 * Note that we don't handle string _UIDs yet.
297 		 */
298 		unsigned long long value;
299 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
300 						NULL, &value);
301 		if (ACPI_FAILURE(status)) {
302 			printk(KERN_ERR PREFIX
303 			    "Evaluating processor _UID [%#x]\n", status);
304 			return -ENODEV;
305 		}
306 		device_declaration = 1;
307 		pr->acpi_id = value;
308 	}
309 	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
310 
311 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
312 	if (!cpu0_initialized && (cpu_index == -1) &&
313 	    (num_online_cpus() == 1)) {
314 		cpu_index = 0;
315 	}
316 
317 	cpu0_initialized = 1;
318 
319 	pr->id = cpu_index;
320 
321 	/*
322 	 *  Extra Processor objects may be enumerated on MP systems with
323 	 *  less than the max # of CPUs. They should be ignored _iff
324 	 *  they are physically not present.
325 	 */
326 	if (pr->id == -1) {
327 		if (ACPI_FAILURE
328 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
329 			return -ENODEV;
330 		}
331 	}
332 	/*
333 	 * On some boxes several processors use the same processor bus id.
334 	 * But they are located in different scope. For example:
335 	 * \_SB.SCK0.CPU0
336 	 * \_SB.SCK1.CPU0
337 	 * Rename the processor device bus id. And the new bus id will be
338 	 * generated as the following format:
339 	 * CPU+CPU ID.
340 	 */
341 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
342 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
343 			  pr->acpi_id));
344 
345 	if (!object.processor.pblk_address)
346 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
347 	else if (object.processor.pblk_length != 6)
348 		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
349 			    object.processor.pblk_length);
350 	else {
351 		pr->throttling.address = object.processor.pblk_address;
352 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
353 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
354 
355 		pr->pblk = object.processor.pblk_address;
356 
357 		/*
358 		 * We don't care about error returns - we just try to mark
359 		 * these reserved so that nobody else is confused into thinking
360 		 * that this region might be unused..
361 		 *
362 		 * (In particular, allocating the IO range for Cardbus)
363 		 */
364 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
365 	}
366 
367 	/*
368 	 * If ACPI describes a slot number for this CPU, we can use it
369 	 * ensure we get the right value in the "physical id" field
370 	 * of /proc/cpuinfo
371 	 */
372 	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
373 	if (ACPI_SUCCESS(status))
374 		arch_fix_phys_package_id(pr->id, object.integer.value);
375 
376 	return 0;
377 }
378 
379 static DEFINE_PER_CPU(void *, processor_device_array);
380 
381 static void acpi_processor_notify(struct acpi_device *device, u32 event)
382 {
383 	struct acpi_processor *pr = acpi_driver_data(device);
384 	int saved;
385 
386 	if (!pr)
387 		return;
388 
389 	switch (event) {
390 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
391 		saved = pr->performance_platform_limit;
392 		acpi_processor_ppc_has_changed(pr, 1);
393 		if (saved == pr->performance_platform_limit)
394 			break;
395 		acpi_bus_generate_proc_event(device, event,
396 					pr->performance_platform_limit);
397 		acpi_bus_generate_netlink_event(device->pnp.device_class,
398 						  dev_name(&device->dev), event,
399 						  pr->performance_platform_limit);
400 		break;
401 	case ACPI_PROCESSOR_NOTIFY_POWER:
402 		acpi_processor_cst_has_changed(pr);
403 		acpi_bus_generate_proc_event(device, event, 0);
404 		acpi_bus_generate_netlink_event(device->pnp.device_class,
405 						  dev_name(&device->dev), event, 0);
406 		break;
407 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
408 		acpi_processor_tstate_has_changed(pr);
409 		acpi_bus_generate_proc_event(device, event, 0);
410 		acpi_bus_generate_netlink_event(device->pnp.device_class,
411 						  dev_name(&device->dev), event, 0);
412 	default:
413 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
414 				  "Unsupported event [0x%x]\n", event));
415 		break;
416 	}
417 
418 	return;
419 }
420 
421 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
422 		unsigned long action, void *hcpu)
423 {
424 	unsigned int cpu = (unsigned long)hcpu;
425 	struct acpi_processor *pr = per_cpu(processors, cpu);
426 
427 	if (action == CPU_ONLINE && pr) {
428 		acpi_processor_ppc_has_changed(pr, 0);
429 		acpi_processor_cst_has_changed(pr);
430 		acpi_processor_reevaluate_tstate(pr, action);
431 		acpi_processor_tstate_has_changed(pr);
432 	}
433 	if (action == CPU_DEAD && pr) {
434 		/* invalidate the flag.throttling after one CPU is offline */
435 		acpi_processor_reevaluate_tstate(pr, action);
436 	}
437 	return NOTIFY_OK;
438 }
439 
440 static struct notifier_block acpi_cpu_notifier =
441 {
442 	    .notifier_call = acpi_cpu_soft_notify,
443 };
444 
445 static int __cpuinit acpi_processor_add(struct acpi_device *device)
446 {
447 	struct acpi_processor *pr = NULL;
448 	int result = 0;
449 	struct sys_device *sysdev;
450 
451 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
452 	if (!pr)
453 		return -ENOMEM;
454 
455 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
456 		kfree(pr);
457 		return -ENOMEM;
458 	}
459 
460 	pr->handle = device->handle;
461 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
462 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
463 	device->driver_data = pr;
464 
465 	result = acpi_processor_get_info(device);
466 	if (result) {
467 		/* Processor is physically not present */
468 		return 0;
469 	}
470 
471 #ifdef CONFIG_SMP
472 	if (pr->id >= setup_max_cpus && pr->id != 0)
473 		return 0;
474 #endif
475 
476 	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
477 
478 	/*
479 	 * Buggy BIOS check
480 	 * ACPI id of processors can be reported wrongly by the BIOS.
481 	 * Don't trust it blindly
482 	 */
483 	if (per_cpu(processor_device_array, pr->id) != NULL &&
484 	    per_cpu(processor_device_array, pr->id) != device) {
485 		printk(KERN_WARNING "BIOS reported wrong ACPI id "
486 			"for the processor\n");
487 		result = -ENODEV;
488 		goto err_free_cpumask;
489 	}
490 	per_cpu(processor_device_array, pr->id) = device;
491 
492 	per_cpu(processors, pr->id) = pr;
493 
494 	sysdev = get_cpu_sysdev(pr->id);
495 	if (sysfs_create_link(&device->dev.kobj, &sysdev->kobj, "sysdev")) {
496 		result = -EFAULT;
497 		goto err_free_cpumask;
498 	}
499 
500 #ifdef CONFIG_CPU_FREQ
501 	acpi_processor_ppc_has_changed(pr, 0);
502 #endif
503 	acpi_processor_get_throttling_info(pr);
504 	acpi_processor_get_limit_info(pr);
505 
506 
507 	if (cpuidle_get_driver() == &acpi_idle_driver)
508 		acpi_processor_power_init(pr, device);
509 
510 	pr->cdev = thermal_cooling_device_register("Processor", device,
511 						&processor_cooling_ops);
512 	if (IS_ERR(pr->cdev)) {
513 		result = PTR_ERR(pr->cdev);
514 		goto err_power_exit;
515 	}
516 
517 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
518 		 pr->cdev->id);
519 
520 	result = sysfs_create_link(&device->dev.kobj,
521 				   &pr->cdev->device.kobj,
522 				   "thermal_cooling");
523 	if (result) {
524 		printk(KERN_ERR PREFIX "Create sysfs link\n");
525 		goto err_thermal_unregister;
526 	}
527 	result = sysfs_create_link(&pr->cdev->device.kobj,
528 				   &device->dev.kobj,
529 				   "device");
530 	if (result) {
531 		printk(KERN_ERR PREFIX "Create sysfs link\n");
532 		goto err_remove_sysfs;
533 	}
534 
535 	return 0;
536 
537 err_remove_sysfs:
538 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
539 err_thermal_unregister:
540 	thermal_cooling_device_unregister(pr->cdev);
541 err_power_exit:
542 	acpi_processor_power_exit(pr, device);
543 err_free_cpumask:
544 	free_cpumask_var(pr->throttling.shared_cpu_map);
545 
546 	return result;
547 }
548 
549 static int acpi_processor_remove(struct acpi_device *device, int type)
550 {
551 	struct acpi_processor *pr = NULL;
552 
553 
554 	if (!device || !acpi_driver_data(device))
555 		return -EINVAL;
556 
557 	pr = acpi_driver_data(device);
558 
559 	if (pr->id >= nr_cpu_ids)
560 		goto free;
561 
562 	if (type == ACPI_BUS_REMOVAL_EJECT) {
563 		if (acpi_processor_handle_eject(pr))
564 			return -EINVAL;
565 	}
566 
567 	acpi_processor_power_exit(pr, device);
568 
569 	sysfs_remove_link(&device->dev.kobj, "sysdev");
570 
571 	if (pr->cdev) {
572 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
573 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
574 		thermal_cooling_device_unregister(pr->cdev);
575 		pr->cdev = NULL;
576 	}
577 
578 	per_cpu(processors, pr->id) = NULL;
579 	per_cpu(processor_device_array, pr->id) = NULL;
580 
581 free:
582 	free_cpumask_var(pr->throttling.shared_cpu_map);
583 	kfree(pr);
584 
585 	return 0;
586 }
587 
588 #ifdef CONFIG_ACPI_HOTPLUG_CPU
589 /****************************************************************************
590  * 	Acpi processor hotplug support 				       	    *
591  ****************************************************************************/
592 
593 static int is_processor_present(acpi_handle handle)
594 {
595 	acpi_status status;
596 	unsigned long long sta = 0;
597 
598 
599 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
600 
601 	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
602 		return 1;
603 
604 	/*
605 	 * _STA is mandatory for a processor that supports hot plug
606 	 */
607 	if (status == AE_NOT_FOUND)
608 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
609 				"Processor does not support hot plug\n"));
610 	else
611 		ACPI_EXCEPTION((AE_INFO, status,
612 				"Processor Device is not present"));
613 	return 0;
614 }
615 
616 static
617 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
618 {
619 	acpi_handle phandle;
620 	struct acpi_device *pdev;
621 
622 
623 	if (acpi_get_parent(handle, &phandle)) {
624 		return -ENODEV;
625 	}
626 
627 	if (acpi_bus_get_device(phandle, &pdev)) {
628 		return -ENODEV;
629 	}
630 
631 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
632 		return -ENODEV;
633 	}
634 
635 	return 0;
636 }
637 
638 static void __ref acpi_processor_hotplug_notify(acpi_handle handle,
639 						u32 event, void *data)
640 {
641 	struct acpi_processor *pr;
642 	struct acpi_device *device = NULL;
643 	int result;
644 
645 
646 	switch (event) {
647 	case ACPI_NOTIFY_BUS_CHECK:
648 	case ACPI_NOTIFY_DEVICE_CHECK:
649 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
650 		"Processor driver received %s event\n",
651 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
652 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
653 
654 		if (!is_processor_present(handle))
655 			break;
656 
657 		if (acpi_bus_get_device(handle, &device)) {
658 			result = acpi_processor_device_add(handle, &device);
659 			if (result)
660 				printk(KERN_ERR PREFIX
661 					    "Unable to add the device\n");
662 			break;
663 		}
664 		break;
665 	case ACPI_NOTIFY_EJECT_REQUEST:
666 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
667 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
668 
669 		if (acpi_bus_get_device(handle, &device)) {
670 			printk(KERN_ERR PREFIX
671 				    "Device don't exist, dropping EJECT\n");
672 			break;
673 		}
674 		pr = acpi_driver_data(device);
675 		if (!pr) {
676 			printk(KERN_ERR PREFIX
677 				    "Driver data is NULL, dropping EJECT\n");
678 			return;
679 		}
680 		break;
681 	default:
682 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
683 				  "Unsupported event [0x%x]\n", event));
684 		break;
685 	}
686 
687 	return;
688 }
689 
690 static acpi_status
691 processor_walk_namespace_cb(acpi_handle handle,
692 			    u32 lvl, void *context, void **rv)
693 {
694 	acpi_status status;
695 	int *action = context;
696 	acpi_object_type type = 0;
697 
698 	status = acpi_get_type(handle, &type);
699 	if (ACPI_FAILURE(status))
700 		return (AE_OK);
701 
702 	if (type != ACPI_TYPE_PROCESSOR)
703 		return (AE_OK);
704 
705 	switch (*action) {
706 	case INSTALL_NOTIFY_HANDLER:
707 		acpi_install_notify_handler(handle,
708 					    ACPI_SYSTEM_NOTIFY,
709 					    acpi_processor_hotplug_notify,
710 					    NULL);
711 		break;
712 	case UNINSTALL_NOTIFY_HANDLER:
713 		acpi_remove_notify_handler(handle,
714 					   ACPI_SYSTEM_NOTIFY,
715 					   acpi_processor_hotplug_notify);
716 		break;
717 	default:
718 		break;
719 	}
720 
721 	return (AE_OK);
722 }
723 
724 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
725 {
726 
727 	if (!is_processor_present(handle)) {
728 		return AE_ERROR;
729 	}
730 
731 	if (acpi_map_lsapic(handle, p_cpu))
732 		return AE_ERROR;
733 
734 	if (arch_register_cpu(*p_cpu)) {
735 		acpi_unmap_lsapic(*p_cpu);
736 		return AE_ERROR;
737 	}
738 
739 	return AE_OK;
740 }
741 
742 static int acpi_processor_handle_eject(struct acpi_processor *pr)
743 {
744 	if (cpu_online(pr->id))
745 		cpu_down(pr->id);
746 
747 	arch_unregister_cpu(pr->id);
748 	acpi_unmap_lsapic(pr->id);
749 	return (0);
750 }
751 #else
752 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
753 {
754 	return AE_ERROR;
755 }
756 static int acpi_processor_handle_eject(struct acpi_processor *pr)
757 {
758 	return (-EINVAL);
759 }
760 #endif
761 
762 static
763 void acpi_processor_install_hotplug_notify(void)
764 {
765 #ifdef CONFIG_ACPI_HOTPLUG_CPU
766 	int action = INSTALL_NOTIFY_HANDLER;
767 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
768 			    ACPI_ROOT_OBJECT,
769 			    ACPI_UINT32_MAX,
770 			    processor_walk_namespace_cb, NULL, &action, NULL);
771 #endif
772 	register_hotcpu_notifier(&acpi_cpu_notifier);
773 }
774 
775 static
776 void acpi_processor_uninstall_hotplug_notify(void)
777 {
778 #ifdef CONFIG_ACPI_HOTPLUG_CPU
779 	int action = UNINSTALL_NOTIFY_HANDLER;
780 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
781 			    ACPI_ROOT_OBJECT,
782 			    ACPI_UINT32_MAX,
783 			    processor_walk_namespace_cb, NULL, &action, NULL);
784 #endif
785 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
786 }
787 
788 /*
789  * We keep the driver loaded even when ACPI is not running.
790  * This is needed for the powernow-k8 driver, that works even without
791  * ACPI, but needs symbols from this driver
792  */
793 
794 static int __init acpi_processor_init(void)
795 {
796 	int result = 0;
797 
798 	if (acpi_disabled)
799 		return 0;
800 
801 	memset(&errata, 0, sizeof(errata));
802 
803 	if (!cpuidle_register_driver(&acpi_idle_driver)) {
804 		printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
805 			acpi_idle_driver.name);
806 	} else {
807 		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s\n",
808 			cpuidle_get_driver()->name);
809 	}
810 
811 	result = acpi_bus_register_driver(&acpi_processor_driver);
812 	if (result < 0)
813 		goto out_cpuidle;
814 
815 	acpi_processor_install_hotplug_notify();
816 
817 	acpi_thermal_cpufreq_init();
818 
819 	acpi_processor_ppc_init();
820 
821 	acpi_processor_throttling_init();
822 
823 	return 0;
824 
825 out_cpuidle:
826 	cpuidle_unregister_driver(&acpi_idle_driver);
827 
828 	return result;
829 }
830 
831 static void __exit acpi_processor_exit(void)
832 {
833 	if (acpi_disabled)
834 		return;
835 
836 	acpi_processor_ppc_exit();
837 
838 	acpi_thermal_cpufreq_exit();
839 
840 	acpi_processor_uninstall_hotplug_notify();
841 
842 	acpi_bus_unregister_driver(&acpi_processor_driver);
843 
844 	cpuidle_unregister_driver(&acpi_idle_driver);
845 
846 	return;
847 }
848 
849 module_init(acpi_processor_init);
850 module_exit(acpi_processor_exit);
851 
852 MODULE_ALIAS("processor");
853