xref: /linux/drivers/acpi/processor_driver.c (revision c053784454550cf750399caa65482b31ffbe3c57)
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/proc_fs.h>
44 #include <linux/seq_file.h>
45 #include <linux/dmi.h>
46 #include <linux/moduleparam.h>
47 #include <linux/cpuidle.h>
48 #include <linux/slab.h>
49 
50 #include <asm/io.h>
51 #include <asm/system.h>
52 #include <asm/cpu.h>
53 #include <asm/delay.h>
54 #include <asm/uaccess.h>
55 #include <asm/processor.h>
56 #include <asm/smp.h>
57 #include <asm/acpi.h>
58 
59 #include <acpi/acpi_bus.h>
60 #include <acpi/acpi_drivers.h>
61 #include <acpi/processor.h>
62 
63 #define PREFIX "ACPI: "
64 
65 #define ACPI_PROCESSOR_CLASS		"processor"
66 #define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
67 #define ACPI_PROCESSOR_FILE_INFO	"info"
68 #define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
69 #define ACPI_PROCESSOR_FILE_LIMIT	"limit"
70 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
71 #define ACPI_PROCESSOR_NOTIFY_POWER	0x81
72 #define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82
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, int type);
86 static void acpi_processor_notify(struct acpi_device *device, u32 event);
87 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
88 static int acpi_processor_handle_eject(struct acpi_processor *pr);
89 
90 
91 static const struct acpi_device_id processor_device_ids[] = {
92 	{ACPI_PROCESSOR_OBJECT_HID, 0},
93 	{"ACPI0007", 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 		.suspend = acpi_processor_suspend,
106 		.resume = acpi_processor_resume,
107 		.notify = acpi_processor_notify,
108 		},
109 };
110 
111 #define INSTALL_NOTIFY_HANDLER		1
112 #define UNINSTALL_NOTIFY_HANDLER	2
113 
114 DEFINE_PER_CPU(struct acpi_processor *, processors);
115 EXPORT_PER_CPU_SYMBOL(processors);
116 
117 struct acpi_processor_errata errata __read_mostly;
118 
119 /* --------------------------------------------------------------------------
120                                 Errata Handling
121    -------------------------------------------------------------------------- */
122 
123 static int acpi_processor_errata_piix4(struct pci_dev *dev)
124 {
125 	u8 value1 = 0;
126 	u8 value2 = 0;
127 
128 
129 	if (!dev)
130 		return -EINVAL;
131 
132 	/*
133 	 * Note that 'dev' references the PIIX4 ACPI Controller.
134 	 */
135 
136 	switch (dev->revision) {
137 	case 0:
138 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
139 		break;
140 	case 1:
141 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
142 		break;
143 	case 2:
144 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
145 		break;
146 	case 3:
147 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
148 		break;
149 	default:
150 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
151 		break;
152 	}
153 
154 	switch (dev->revision) {
155 
156 	case 0:		/* PIIX4 A-step */
157 	case 1:		/* PIIX4 B-step */
158 		/*
159 		 * See specification changes #13 ("Manual Throttle Duty Cycle")
160 		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
161 		 * erratum #5 ("STPCLK# Deassertion Time") from the January
162 		 * 2002 PIIX4 specification update.  Applies to only older
163 		 * PIIX4 models.
164 		 */
165 		errata.piix4.throttle = 1;
166 
167 	case 2:		/* PIIX4E */
168 	case 3:		/* PIIX4M */
169 		/*
170 		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
171 		 * Livelock") from the January 2002 PIIX4 specification update.
172 		 * Applies to all PIIX4 models.
173 		 */
174 
175 		/*
176 		 * BM-IDE
177 		 * ------
178 		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
179 		 * Status register address.  We'll use this later to read
180 		 * each IDE controller's DMA status to make sure we catch all
181 		 * DMA activity.
182 		 */
183 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
184 				     PCI_DEVICE_ID_INTEL_82371AB,
185 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
186 		if (dev) {
187 			errata.piix4.bmisx = pci_resource_start(dev, 4);
188 			pci_dev_put(dev);
189 		}
190 
191 		/*
192 		 * Type-F DMA
193 		 * ----------
194 		 * Find the PIIX4 ISA Controller and read the Motherboard
195 		 * DMA controller's status to see if Type-F (Fast) DMA mode
196 		 * is enabled (bit 7) on either channel.  Note that we'll
197 		 * disable C3 support if this is enabled, as some legacy
198 		 * devices won't operate well if fast DMA is disabled.
199 		 */
200 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
201 				     PCI_DEVICE_ID_INTEL_82371AB_0,
202 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
203 		if (dev) {
204 			pci_read_config_byte(dev, 0x76, &value1);
205 			pci_read_config_byte(dev, 0x77, &value2);
206 			if ((value1 & 0x80) || (value2 & 0x80))
207 				errata.piix4.fdma = 1;
208 			pci_dev_put(dev);
209 		}
210 
211 		break;
212 	}
213 
214 	if (errata.piix4.bmisx)
215 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
216 				  "Bus master activity detection (BM-IDE) erratum enabled\n"));
217 	if (errata.piix4.fdma)
218 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
219 				  "Type-F DMA livelock erratum (C3 disabled)\n"));
220 
221 	return 0;
222 }
223 
224 static int acpi_processor_errata(struct acpi_processor *pr)
225 {
226 	int result = 0;
227 	struct pci_dev *dev = NULL;
228 
229 
230 	if (!pr)
231 		return -EINVAL;
232 
233 	/*
234 	 * PIIX4
235 	 */
236 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
237 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
238 			     PCI_ANY_ID, NULL);
239 	if (dev) {
240 		result = acpi_processor_errata_piix4(dev);
241 		pci_dev_put(dev);
242 	}
243 
244 	return result;
245 }
246 
247 static struct proc_dir_entry *acpi_processor_dir = NULL;
248 
249 static int __cpuinit acpi_processor_add_fs(struct acpi_device *device)
250 {
251 	struct proc_dir_entry *entry = NULL;
252 
253 
254 	if (!acpi_device_dir(device)) {
255 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
256 						     acpi_processor_dir);
257 		if (!acpi_device_dir(device))
258 			return -ENODEV;
259 	}
260 
261 	/* 'throttling' [R/W] */
262 	entry = proc_create_data(ACPI_PROCESSOR_FILE_THROTTLING,
263 				 S_IFREG | S_IRUGO | S_IWUSR,
264 				 acpi_device_dir(device),
265 				 &acpi_processor_throttling_fops,
266 				 acpi_driver_data(device));
267 	if (!entry)
268 		return -EIO;
269 	return 0;
270 }
271 static int acpi_processor_remove_fs(struct acpi_device *device)
272 {
273 
274 	if (acpi_device_dir(device)) {
275 		remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
276 				  acpi_device_dir(device));
277 		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
278 		acpi_device_dir(device) = NULL;
279 	}
280 
281 	return 0;
282 }
283 
284 /* --------------------------------------------------------------------------
285                                  Driver Interface
286    -------------------------------------------------------------------------- */
287 
288 static int acpi_processor_get_info(struct acpi_device *device)
289 {
290 	acpi_status status = 0;
291 	union acpi_object object = { 0 };
292 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
293 	struct acpi_processor *pr;
294 	int cpu_index, device_declaration = 0;
295 	static int cpu0_initialized;
296 
297 	pr = acpi_driver_data(device);
298 	if (!pr)
299 		return -EINVAL;
300 
301 	if (num_online_cpus() > 1)
302 		errata.smp = TRUE;
303 
304 	acpi_processor_errata(pr);
305 
306 	/*
307 	 * Check to see if we have bus mastering arbitration control.  This
308 	 * is required for proper C3 usage (to maintain cache coherency).
309 	 */
310 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
311 		pr->flags.bm_control = 1;
312 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
313 				  "Bus mastering arbitration control present\n"));
314 	} else
315 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
316 				  "No bus mastering arbitration control\n"));
317 
318 	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
319 		/* Declared with "Processor" statement; match ProcessorID */
320 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
321 		if (ACPI_FAILURE(status)) {
322 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
323 			return -ENODEV;
324 		}
325 
326 		/*
327 		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
328 		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
329 		 *      arch/xxx/acpi.c
330 		 */
331 		pr->acpi_id = object.processor.proc_id;
332 	} else {
333 		/*
334 		 * Declared with "Device" statement; match _UID.
335 		 * Note that we don't handle string _UIDs yet.
336 		 */
337 		unsigned long long value;
338 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
339 						NULL, &value);
340 		if (ACPI_FAILURE(status)) {
341 			printk(KERN_ERR PREFIX
342 			    "Evaluating processor _UID [%#x]\n", status);
343 			return -ENODEV;
344 		}
345 		device_declaration = 1;
346 		pr->acpi_id = value;
347 	}
348 	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
349 
350 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
351 	if (!cpu0_initialized && (cpu_index == -1) &&
352 	    (num_online_cpus() == 1)) {
353 		cpu_index = 0;
354 	}
355 
356 	cpu0_initialized = 1;
357 
358 	pr->id = cpu_index;
359 
360 	/*
361 	 *  Extra Processor objects may be enumerated on MP systems with
362 	 *  less than the max # of CPUs. They should be ignored _iff
363 	 *  they are physically not present.
364 	 */
365 	if (pr->id == -1) {
366 		if (ACPI_FAILURE
367 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
368 			return -ENODEV;
369 		}
370 	}
371 	/*
372 	 * On some boxes several processors use the same processor bus id.
373 	 * But they are located in different scope. For example:
374 	 * \_SB.SCK0.CPU0
375 	 * \_SB.SCK1.CPU0
376 	 * Rename the processor device bus id. And the new bus id will be
377 	 * generated as the following format:
378 	 * CPU+CPU ID.
379 	 */
380 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
381 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
382 			  pr->acpi_id));
383 
384 	if (!object.processor.pblk_address)
385 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
386 	else if (object.processor.pblk_length != 6)
387 		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
388 			    object.processor.pblk_length);
389 	else {
390 		pr->throttling.address = object.processor.pblk_address;
391 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
392 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
393 
394 		pr->pblk = object.processor.pblk_address;
395 
396 		/*
397 		 * We don't care about error returns - we just try to mark
398 		 * these reserved so that nobody else is confused into thinking
399 		 * that this region might be unused..
400 		 *
401 		 * (In particular, allocating the IO range for Cardbus)
402 		 */
403 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
404 	}
405 
406 	/*
407 	 * If ACPI describes a slot number for this CPU, we can use it
408 	 * ensure we get the right value in the "physical id" field
409 	 * of /proc/cpuinfo
410 	 */
411 	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
412 	if (ACPI_SUCCESS(status))
413 		arch_fix_phys_package_id(pr->id, object.integer.value);
414 
415 	return 0;
416 }
417 
418 static DEFINE_PER_CPU(void *, processor_device_array);
419 
420 static void acpi_processor_notify(struct acpi_device *device, u32 event)
421 {
422 	struct acpi_processor *pr = acpi_driver_data(device);
423 	int saved;
424 
425 	if (!pr)
426 		return;
427 
428 	switch (event) {
429 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
430 		saved = pr->performance_platform_limit;
431 		acpi_processor_ppc_has_changed(pr, 1);
432 		if (saved == pr->performance_platform_limit)
433 			break;
434 		acpi_bus_generate_proc_event(device, event,
435 					pr->performance_platform_limit);
436 		acpi_bus_generate_netlink_event(device->pnp.device_class,
437 						  dev_name(&device->dev), event,
438 						  pr->performance_platform_limit);
439 		break;
440 	case ACPI_PROCESSOR_NOTIFY_POWER:
441 		acpi_processor_cst_has_changed(pr);
442 		acpi_bus_generate_proc_event(device, event, 0);
443 		acpi_bus_generate_netlink_event(device->pnp.device_class,
444 						  dev_name(&device->dev), event, 0);
445 		break;
446 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
447 		acpi_processor_tstate_has_changed(pr);
448 		acpi_bus_generate_proc_event(device, event, 0);
449 		acpi_bus_generate_netlink_event(device->pnp.device_class,
450 						  dev_name(&device->dev), event, 0);
451 	default:
452 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
453 				  "Unsupported event [0x%x]\n", event));
454 		break;
455 	}
456 
457 	return;
458 }
459 
460 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
461 		unsigned long action, void *hcpu)
462 {
463 	unsigned int cpu = (unsigned long)hcpu;
464 	struct acpi_processor *pr = per_cpu(processors, cpu);
465 
466 	if (action == CPU_ONLINE && pr) {
467 		acpi_processor_ppc_has_changed(pr, 0);
468 		acpi_processor_cst_has_changed(pr);
469 		acpi_processor_tstate_has_changed(pr);
470 	}
471 	return NOTIFY_OK;
472 }
473 
474 static struct notifier_block acpi_cpu_notifier =
475 {
476 	    .notifier_call = acpi_cpu_soft_notify,
477 };
478 
479 static int __cpuinit acpi_processor_add(struct acpi_device *device)
480 {
481 	struct acpi_processor *pr = NULL;
482 	int result = 0;
483 	struct sys_device *sysdev;
484 
485 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
486 	if (!pr)
487 		return -ENOMEM;
488 
489 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
490 		kfree(pr);
491 		return -ENOMEM;
492 	}
493 
494 	pr->handle = device->handle;
495 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
496 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
497 	device->driver_data = pr;
498 
499 	result = acpi_processor_get_info(device);
500 	if (result) {
501 		/* Processor is physically not present */
502 		return 0;
503 	}
504 
505 #ifdef CONFIG_SMP
506 	if (pr->id >= setup_max_cpus && pr->id != 0)
507 		return 0;
508 #endif
509 
510 	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
511 
512 	/*
513 	 * Buggy BIOS check
514 	 * ACPI id of processors can be reported wrongly by the BIOS.
515 	 * Don't trust it blindly
516 	 */
517 	if (per_cpu(processor_device_array, pr->id) != NULL &&
518 	    per_cpu(processor_device_array, pr->id) != device) {
519 		printk(KERN_WARNING "BIOS reported wrong ACPI id "
520 			"for the processor\n");
521 		result = -ENODEV;
522 		goto err_free_cpumask;
523 	}
524 	per_cpu(processor_device_array, pr->id) = device;
525 
526 	per_cpu(processors, pr->id) = pr;
527 
528 	result = acpi_processor_add_fs(device);
529 	if (result)
530 		goto err_free_cpumask;
531 
532 	sysdev = get_cpu_sysdev(pr->id);
533 	if (sysfs_create_link(&device->dev.kobj, &sysdev->kobj, "sysdev")) {
534 		result = -EFAULT;
535 		goto err_remove_fs;
536 	}
537 
538 #ifdef CONFIG_CPU_FREQ
539 	acpi_processor_ppc_has_changed(pr, 0);
540 #endif
541 	acpi_processor_get_throttling_info(pr);
542 	acpi_processor_get_limit_info(pr);
543 
544 
545 	if (cpuidle_get_driver() == &acpi_idle_driver)
546 		acpi_processor_power_init(pr, device);
547 
548 	pr->cdev = thermal_cooling_device_register("Processor", device,
549 						&processor_cooling_ops);
550 	if (IS_ERR(pr->cdev)) {
551 		result = PTR_ERR(pr->cdev);
552 		goto err_power_exit;
553 	}
554 
555 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
556 		 pr->cdev->id);
557 
558 	result = sysfs_create_link(&device->dev.kobj,
559 				   &pr->cdev->device.kobj,
560 				   "thermal_cooling");
561 	if (result) {
562 		printk(KERN_ERR PREFIX "Create sysfs link\n");
563 		goto err_thermal_unregister;
564 	}
565 	result = sysfs_create_link(&pr->cdev->device.kobj,
566 				   &device->dev.kobj,
567 				   "device");
568 	if (result) {
569 		printk(KERN_ERR PREFIX "Create sysfs link\n");
570 		goto err_remove_sysfs;
571 	}
572 
573 	return 0;
574 
575 err_remove_sysfs:
576 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
577 err_thermal_unregister:
578 	thermal_cooling_device_unregister(pr->cdev);
579 err_power_exit:
580 	acpi_processor_power_exit(pr, device);
581 err_remove_fs:
582 	acpi_processor_remove_fs(device);
583 err_free_cpumask:
584 	free_cpumask_var(pr->throttling.shared_cpu_map);
585 
586 	return result;
587 }
588 
589 static int acpi_processor_remove(struct acpi_device *device, int type)
590 {
591 	struct acpi_processor *pr = NULL;
592 
593 
594 	if (!device || !acpi_driver_data(device))
595 		return -EINVAL;
596 
597 	pr = acpi_driver_data(device);
598 
599 	if (pr->id >= nr_cpu_ids)
600 		goto free;
601 
602 	if (type == ACPI_BUS_REMOVAL_EJECT) {
603 		if (acpi_processor_handle_eject(pr))
604 			return -EINVAL;
605 	}
606 
607 	acpi_processor_power_exit(pr, device);
608 
609 	sysfs_remove_link(&device->dev.kobj, "sysdev");
610 
611 	acpi_processor_remove_fs(device);
612 
613 	if (pr->cdev) {
614 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
615 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
616 		thermal_cooling_device_unregister(pr->cdev);
617 		pr->cdev = NULL;
618 	}
619 
620 	per_cpu(processors, pr->id) = NULL;
621 	per_cpu(processor_device_array, pr->id) = NULL;
622 
623 free:
624 	free_cpumask_var(pr->throttling.shared_cpu_map);
625 	kfree(pr);
626 
627 	return 0;
628 }
629 
630 #ifdef CONFIG_ACPI_HOTPLUG_CPU
631 /****************************************************************************
632  * 	Acpi processor hotplug support 				       	    *
633  ****************************************************************************/
634 
635 static int is_processor_present(acpi_handle handle)
636 {
637 	acpi_status status;
638 	unsigned long long sta = 0;
639 
640 
641 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
642 
643 	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
644 		return 1;
645 
646 	/*
647 	 * _STA is mandatory for a processor that supports hot plug
648 	 */
649 	if (status == AE_NOT_FOUND)
650 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
651 				"Processor does not support hot plug\n"));
652 	else
653 		ACPI_EXCEPTION((AE_INFO, status,
654 				"Processor Device is not present"));
655 	return 0;
656 }
657 
658 static
659 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
660 {
661 	acpi_handle phandle;
662 	struct acpi_device *pdev;
663 
664 
665 	if (acpi_get_parent(handle, &phandle)) {
666 		return -ENODEV;
667 	}
668 
669 	if (acpi_bus_get_device(phandle, &pdev)) {
670 		return -ENODEV;
671 	}
672 
673 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
674 		return -ENODEV;
675 	}
676 
677 	return 0;
678 }
679 
680 static void __ref acpi_processor_hotplug_notify(acpi_handle handle,
681 						u32 event, void *data)
682 {
683 	struct acpi_processor *pr;
684 	struct acpi_device *device = NULL;
685 	int result;
686 
687 
688 	switch (event) {
689 	case ACPI_NOTIFY_BUS_CHECK:
690 	case ACPI_NOTIFY_DEVICE_CHECK:
691 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
692 		"Processor driver received %s event\n",
693 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
694 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
695 
696 		if (!is_processor_present(handle))
697 			break;
698 
699 		if (acpi_bus_get_device(handle, &device)) {
700 			result = acpi_processor_device_add(handle, &device);
701 			if (result)
702 				printk(KERN_ERR PREFIX
703 					    "Unable to add the device\n");
704 			break;
705 		}
706 		break;
707 	case ACPI_NOTIFY_EJECT_REQUEST:
708 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
709 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
710 
711 		if (acpi_bus_get_device(handle, &device)) {
712 			printk(KERN_ERR PREFIX
713 				    "Device don't exist, dropping EJECT\n");
714 			break;
715 		}
716 		pr = acpi_driver_data(device);
717 		if (!pr) {
718 			printk(KERN_ERR PREFIX
719 				    "Driver data is NULL, dropping EJECT\n");
720 			return;
721 		}
722 		break;
723 	default:
724 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
725 				  "Unsupported event [0x%x]\n", event));
726 		break;
727 	}
728 
729 	return;
730 }
731 
732 static acpi_status
733 processor_walk_namespace_cb(acpi_handle handle,
734 			    u32 lvl, void *context, void **rv)
735 {
736 	acpi_status status;
737 	int *action = context;
738 	acpi_object_type type = 0;
739 
740 	status = acpi_get_type(handle, &type);
741 	if (ACPI_FAILURE(status))
742 		return (AE_OK);
743 
744 	if (type != ACPI_TYPE_PROCESSOR)
745 		return (AE_OK);
746 
747 	switch (*action) {
748 	case INSTALL_NOTIFY_HANDLER:
749 		acpi_install_notify_handler(handle,
750 					    ACPI_SYSTEM_NOTIFY,
751 					    acpi_processor_hotplug_notify,
752 					    NULL);
753 		break;
754 	case UNINSTALL_NOTIFY_HANDLER:
755 		acpi_remove_notify_handler(handle,
756 					   ACPI_SYSTEM_NOTIFY,
757 					   acpi_processor_hotplug_notify);
758 		break;
759 	default:
760 		break;
761 	}
762 
763 	return (AE_OK);
764 }
765 
766 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
767 {
768 
769 	if (!is_processor_present(handle)) {
770 		return AE_ERROR;
771 	}
772 
773 	if (acpi_map_lsapic(handle, p_cpu))
774 		return AE_ERROR;
775 
776 	if (arch_register_cpu(*p_cpu)) {
777 		acpi_unmap_lsapic(*p_cpu);
778 		return AE_ERROR;
779 	}
780 
781 	return AE_OK;
782 }
783 
784 static int acpi_processor_handle_eject(struct acpi_processor *pr)
785 {
786 	if (cpu_online(pr->id))
787 		cpu_down(pr->id);
788 
789 	arch_unregister_cpu(pr->id);
790 	acpi_unmap_lsapic(pr->id);
791 	return (0);
792 }
793 #else
794 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
795 {
796 	return AE_ERROR;
797 }
798 static int acpi_processor_handle_eject(struct acpi_processor *pr)
799 {
800 	return (-EINVAL);
801 }
802 #endif
803 
804 static
805 void acpi_processor_install_hotplug_notify(void)
806 {
807 #ifdef CONFIG_ACPI_HOTPLUG_CPU
808 	int action = INSTALL_NOTIFY_HANDLER;
809 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
810 			    ACPI_ROOT_OBJECT,
811 			    ACPI_UINT32_MAX,
812 			    processor_walk_namespace_cb, NULL, &action, NULL);
813 #endif
814 	register_hotcpu_notifier(&acpi_cpu_notifier);
815 }
816 
817 static
818 void acpi_processor_uninstall_hotplug_notify(void)
819 {
820 #ifdef CONFIG_ACPI_HOTPLUG_CPU
821 	int action = UNINSTALL_NOTIFY_HANDLER;
822 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
823 			    ACPI_ROOT_OBJECT,
824 			    ACPI_UINT32_MAX,
825 			    processor_walk_namespace_cb, NULL, &action, NULL);
826 #endif
827 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
828 }
829 
830 /*
831  * We keep the driver loaded even when ACPI is not running.
832  * This is needed for the powernow-k8 driver, that works even without
833  * ACPI, but needs symbols from this driver
834  */
835 
836 static int __init acpi_processor_init(void)
837 {
838 	int result = 0;
839 
840 	if (acpi_disabled)
841 		return 0;
842 
843 	memset(&errata, 0, sizeof(errata));
844 
845 	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
846 	if (!acpi_processor_dir)
847 		return -ENOMEM;
848 
849 	if (!cpuidle_register_driver(&acpi_idle_driver)) {
850 		printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
851 			acpi_idle_driver.name);
852 	} else {
853 		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s\n",
854 			cpuidle_get_driver()->name);
855 	}
856 
857 	result = acpi_bus_register_driver(&acpi_processor_driver);
858 	if (result < 0)
859 		goto out_cpuidle;
860 
861 	acpi_processor_install_hotplug_notify();
862 
863 	acpi_thermal_cpufreq_init();
864 
865 	acpi_processor_ppc_init();
866 
867 	acpi_processor_throttling_init();
868 
869 	return 0;
870 
871 out_cpuidle:
872 	cpuidle_unregister_driver(&acpi_idle_driver);
873 
874 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
875 
876 	return result;
877 }
878 
879 static void __exit acpi_processor_exit(void)
880 {
881 	if (acpi_disabled)
882 		return;
883 
884 	acpi_processor_ppc_exit();
885 
886 	acpi_thermal_cpufreq_exit();
887 
888 	acpi_processor_uninstall_hotplug_notify();
889 
890 	acpi_bus_unregister_driver(&acpi_processor_driver);
891 
892 	cpuidle_unregister_driver(&acpi_idle_driver);
893 
894 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
895 
896 	return;
897 }
898 
899 module_init(acpi_processor_init);
900 module_exit(acpi_processor_exit);
901 
902 EXPORT_SYMBOL(acpi_processor_set_thermal_limit);
903 
904 MODULE_ALIAS("processor");
905