xref: /linux/drivers/acpi/processor_driver.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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/cpu.h>
50 #include <asm/delay.h>
51 #include <asm/uaccess.h>
52 #include <asm/processor.h>
53 #include <asm/smp.h>
54 #include <asm/acpi.h>
55 
56 #include <acpi/acpi_bus.h>
57 #include <acpi/acpi_drivers.h>
58 #include <acpi/processor.h>
59 
60 #define PREFIX "ACPI: "
61 
62 #define ACPI_PROCESSOR_CLASS		"processor"
63 #define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
64 #define ACPI_PROCESSOR_FILE_INFO	"info"
65 #define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
66 #define ACPI_PROCESSOR_FILE_LIMIT	"limit"
67 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
68 #define ACPI_PROCESSOR_NOTIFY_POWER	0x81
69 #define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82
70 #define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
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(struct acpi_processor *pr);
86 static int acpi_processor_handle_eject(struct acpi_processor *pr);
87 static int acpi_processor_start(struct acpi_processor *pr);
88 
89 static const struct acpi_device_id processor_device_ids[] = {
90 	{ACPI_PROCESSOR_OBJECT_HID, 0},
91 	{ACPI_PROCESSOR_DEVICE_HID, 0},
92 	{"", 0},
93 };
94 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
95 
96 static SIMPLE_DEV_PM_OPS(acpi_processor_pm,
97 			 acpi_processor_suspend, acpi_processor_resume);
98 
99 static struct acpi_driver acpi_processor_driver = {
100 	.name = "processor",
101 	.class = ACPI_PROCESSOR_CLASS,
102 	.ids = processor_device_ids,
103 	.ops = {
104 		.add = acpi_processor_add,
105 		.remove = acpi_processor_remove,
106 		.notify = acpi_processor_notify,
107 		},
108 	.drv.pm = &acpi_processor_pm,
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 /* --------------------------------------------------------------------------
248                                  Driver Interface
249    -------------------------------------------------------------------------- */
250 
251 static int acpi_processor_get_info(struct acpi_device *device)
252 {
253 	acpi_status status = 0;
254 	union acpi_object object = { 0 };
255 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
256 	struct acpi_processor *pr;
257 	int cpu_index, device_declaration = 0;
258 	static int cpu0_initialized;
259 
260 	pr = acpi_driver_data(device);
261 	if (!pr)
262 		return -EINVAL;
263 
264 	if (num_online_cpus() > 1)
265 		errata.smp = TRUE;
266 
267 	acpi_processor_errata(pr);
268 
269 	/*
270 	 * Check to see if we have bus mastering arbitration control.  This
271 	 * is required for proper C3 usage (to maintain cache coherency).
272 	 */
273 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
274 		pr->flags.bm_control = 1;
275 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
276 				  "Bus mastering arbitration control present\n"));
277 	} else
278 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
279 				  "No bus mastering arbitration control\n"));
280 
281 	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
282 		/* Declared with "Processor" statement; match ProcessorID */
283 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
284 		if (ACPI_FAILURE(status)) {
285 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
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 			printk(KERN_ERR PREFIX
305 			    "Evaluating processor _UID [%#x]\n", status);
306 			return -ENODEV;
307 		}
308 		device_declaration = 1;
309 		pr->acpi_id = value;
310 	}
311 	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
312 
313 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
314 	if (!cpu0_initialized && (cpu_index == -1) &&
315 	    (num_online_cpus() == 1)) {
316 		cpu_index = 0;
317 	}
318 
319 	cpu0_initialized = 1;
320 
321 	pr->id = cpu_index;
322 
323 	/*
324 	 *  Extra Processor objects may be enumerated on MP systems with
325 	 *  less than the max # of CPUs. They should be ignored _iff
326 	 *  they are physically not present.
327 	 */
328 	if (pr->id == -1) {
329 		if (ACPI_FAILURE(acpi_processor_hotadd_init(pr)))
330 			return -ENODEV;
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 		/* CPU got physically hotplugged and onlined the first time:
429 		 * Initialize missing things
430 		 */
431 		if (pr->flags.need_hotplug_init) {
432 			printk(KERN_INFO "Will online and init hotplugged "
433 			       "CPU: %d\n", pr->id);
434 			WARN(acpi_processor_start(pr), "Failed to start CPU:"
435 				" %d\n", pr->id);
436 			pr->flags.need_hotplug_init = 0;
437 		/* Normal CPU soft online event */
438 		} else {
439 			acpi_processor_ppc_has_changed(pr, 0);
440 			acpi_processor_hotplug(pr);
441 			acpi_processor_reevaluate_tstate(pr, action);
442 			acpi_processor_tstate_has_changed(pr);
443 		}
444 	}
445 	if (action == CPU_DEAD && pr) {
446 		/* invalidate the flag.throttling after one CPU is offline */
447 		acpi_processor_reevaluate_tstate(pr, action);
448 	}
449 	return NOTIFY_OK;
450 }
451 
452 static struct notifier_block acpi_cpu_notifier =
453 {
454 	    .notifier_call = acpi_cpu_soft_notify,
455 };
456 
457 /*
458  * acpi_processor_start() is called by the cpu_hotplug_notifier func:
459  * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the
460  * root cause seem to be that acpi_processor_uninstall_hotplug_notify()
461  * is in the module_exit (__exit) func. Allowing acpi_processor_start()
462  * to not be in __cpuinit section, but being called from __cpuinit funcs
463  * via __ref looks like the right thing to do here.
464  */
465 static __ref int acpi_processor_start(struct acpi_processor *pr)
466 {
467 	struct acpi_device *device = per_cpu(processor_device_array, pr->id);
468 	int result = 0;
469 
470 #ifdef CONFIG_CPU_FREQ
471 	acpi_processor_ppc_has_changed(pr, 0);
472 	acpi_processor_load_module(pr);
473 #endif
474 	acpi_processor_get_throttling_info(pr);
475 	acpi_processor_get_limit_info(pr);
476 
477 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
478 		acpi_processor_power_init(pr, device);
479 
480 	pr->cdev = thermal_cooling_device_register("Processor", device,
481 						   &processor_cooling_ops);
482 	if (IS_ERR(pr->cdev)) {
483 		result = PTR_ERR(pr->cdev);
484 		goto err_power_exit;
485 	}
486 
487 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
488 		pr->cdev->id);
489 
490 	result = sysfs_create_link(&device->dev.kobj,
491 				   &pr->cdev->device.kobj,
492 				   "thermal_cooling");
493 	if (result) {
494 		printk(KERN_ERR PREFIX "Create sysfs link\n");
495 		goto err_thermal_unregister;
496 	}
497 	result = sysfs_create_link(&pr->cdev->device.kobj,
498 				   &device->dev.kobj,
499 				   "device");
500 	if (result) {
501 		printk(KERN_ERR PREFIX "Create sysfs link\n");
502 		goto err_remove_sysfs_thermal;
503 	}
504 
505 	return 0;
506 
507 err_remove_sysfs_thermal:
508 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
509 err_thermal_unregister:
510 	thermal_cooling_device_unregister(pr->cdev);
511 err_power_exit:
512 	acpi_processor_power_exit(pr, device);
513 
514 	return result;
515 }
516 
517 /*
518  * Do not put anything in here which needs the core to be online.
519  * For example MSR access or setting up things which check for cpuinfo_x86
520  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
521  * Such things have to be put in and set up above in acpi_processor_start()
522  */
523 static int __cpuinit acpi_processor_add(struct acpi_device *device)
524 {
525 	struct acpi_processor *pr = NULL;
526 	int result = 0;
527 	struct device *dev;
528 
529 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
530 	if (!pr)
531 		return -ENOMEM;
532 
533 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
534 		result = -ENOMEM;
535 		goto err_free_pr;
536 	}
537 
538 	pr->handle = device->handle;
539 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
540 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
541 	device->driver_data = pr;
542 
543 	result = acpi_processor_get_info(device);
544 	if (result) {
545 		/* Processor is physically not present */
546 		return 0;
547 	}
548 
549 #ifdef CONFIG_SMP
550 	if (pr->id >= setup_max_cpus && pr->id != 0)
551 		return 0;
552 #endif
553 
554 	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
555 
556 	/*
557 	 * Buggy BIOS check
558 	 * ACPI id of processors can be reported wrongly by the BIOS.
559 	 * Don't trust it blindly
560 	 */
561 	if (per_cpu(processor_device_array, pr->id) != NULL &&
562 	    per_cpu(processor_device_array, pr->id) != device) {
563 		printk(KERN_WARNING "BIOS reported wrong ACPI id "
564 			"for the processor\n");
565 		result = -ENODEV;
566 		goto err_free_cpumask;
567 	}
568 	per_cpu(processor_device_array, pr->id) = device;
569 
570 	per_cpu(processors, pr->id) = pr;
571 
572 	dev = get_cpu_device(pr->id);
573 	if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
574 		result = -EFAULT;
575 		goto err_clear_processor;
576 	}
577 
578 	/*
579 	 * Do not start hotplugged CPUs now, but when they
580 	 * are onlined the first time
581 	 */
582 	if (pr->flags.need_hotplug_init)
583 		return 0;
584 
585 	result = acpi_processor_start(pr);
586 	if (result)
587 		goto err_remove_sysfs;
588 
589 	return 0;
590 
591 err_remove_sysfs:
592 	sysfs_remove_link(&device->dev.kobj, "sysdev");
593 err_clear_processor:
594 	/*
595 	 * processor_device_array is not cleared to allow checks for buggy BIOS
596 	 */
597 	per_cpu(processors, pr->id) = NULL;
598 err_free_cpumask:
599 	free_cpumask_var(pr->throttling.shared_cpu_map);
600 err_free_pr:
601 	kfree(pr);
602 	return result;
603 }
604 
605 static int acpi_processor_remove(struct acpi_device *device, int type)
606 {
607 	struct acpi_processor *pr = NULL;
608 
609 
610 	if (!device || !acpi_driver_data(device))
611 		return -EINVAL;
612 
613 	pr = acpi_driver_data(device);
614 
615 	if (pr->id >= nr_cpu_ids)
616 		goto free;
617 
618 	if (type == ACPI_BUS_REMOVAL_EJECT) {
619 		if (acpi_processor_handle_eject(pr))
620 			return -EINVAL;
621 	}
622 
623 	acpi_processor_power_exit(pr, device);
624 
625 	sysfs_remove_link(&device->dev.kobj, "sysdev");
626 
627 	if (pr->cdev) {
628 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
629 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
630 		thermal_cooling_device_unregister(pr->cdev);
631 		pr->cdev = NULL;
632 	}
633 
634 	per_cpu(processors, pr->id) = NULL;
635 	per_cpu(processor_device_array, pr->id) = NULL;
636 
637 free:
638 	free_cpumask_var(pr->throttling.shared_cpu_map);
639 	kfree(pr);
640 
641 	return 0;
642 }
643 
644 #ifdef CONFIG_ACPI_HOTPLUG_CPU
645 /****************************************************************************
646  * 	Acpi processor hotplug support 				       	    *
647  ****************************************************************************/
648 
649 static int is_processor_present(acpi_handle handle)
650 {
651 	acpi_status status;
652 	unsigned long long sta = 0;
653 
654 
655 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
656 
657 	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
658 		return 1;
659 
660 	/*
661 	 * _STA is mandatory for a processor that supports hot plug
662 	 */
663 	if (status == AE_NOT_FOUND)
664 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
665 				"Processor does not support hot plug\n"));
666 	else
667 		ACPI_EXCEPTION((AE_INFO, status,
668 				"Processor Device is not present"));
669 	return 0;
670 }
671 
672 static
673 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
674 {
675 	acpi_handle phandle;
676 	struct acpi_device *pdev;
677 
678 
679 	if (acpi_get_parent(handle, &phandle)) {
680 		return -ENODEV;
681 	}
682 
683 	if (acpi_bus_get_device(phandle, &pdev)) {
684 		return -ENODEV;
685 	}
686 
687 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
688 		return -ENODEV;
689 	}
690 
691 	return 0;
692 }
693 
694 static void acpi_processor_hotplug_notify(acpi_handle handle,
695 					  u32 event, void *data)
696 {
697 	struct acpi_processor *pr;
698 	struct acpi_device *device = NULL;
699 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
700 	int result;
701 
702 	switch (event) {
703 	case ACPI_NOTIFY_BUS_CHECK:
704 	case ACPI_NOTIFY_DEVICE_CHECK:
705 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
706 		"Processor driver received %s event\n",
707 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
708 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
709 
710 		if (!is_processor_present(handle))
711 			break;
712 
713 		if (!acpi_bus_get_device(handle, &device))
714 			break;
715 
716 		result = acpi_processor_device_add(handle, &device);
717 		if (result) {
718 			printk(KERN_ERR PREFIX "Unable to add the device\n");
719 			break;
720 		}
721 
722 		ost_code = ACPI_OST_SC_SUCCESS;
723 		break;
724 
725 	case ACPI_NOTIFY_EJECT_REQUEST:
726 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
727 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
728 
729 		if (acpi_bus_get_device(handle, &device)) {
730 			printk(KERN_ERR PREFIX
731 				    "Device don't exist, dropping EJECT\n");
732 			break;
733 		}
734 		pr = acpi_driver_data(device);
735 		if (!pr) {
736 			printk(KERN_ERR PREFIX
737 				    "Driver data is NULL, dropping EJECT\n");
738 			break;
739 		}
740 
741 		/* REVISIT: update when eject is supported */
742 		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
743 		break;
744 
745 	default:
746 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
747 				  "Unsupported event [0x%x]\n", event));
748 
749 		/* non-hotplug event; possibly handled by other handler */
750 		return;
751 	}
752 
753 	/* Inform firmware that the hotplug operation has completed */
754 	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
755 	return;
756 }
757 
758 static acpi_status is_processor_device(acpi_handle handle)
759 {
760 	struct acpi_device_info *info;
761 	char *hid;
762 	acpi_status status;
763 
764 	status = acpi_get_object_info(handle, &info);
765 	if (ACPI_FAILURE(status))
766 		return status;
767 
768 	if (info->type == ACPI_TYPE_PROCESSOR) {
769 		kfree(info);
770 		return AE_OK;	/* found a processor object */
771 	}
772 
773 	if (!(info->valid & ACPI_VALID_HID)) {
774 		kfree(info);
775 		return AE_ERROR;
776 	}
777 
778 	hid = info->hardware_id.string;
779 	if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
780 		kfree(info);
781 		return AE_ERROR;
782 	}
783 
784 	kfree(info);
785 	return AE_OK;	/* found a processor device object */
786 }
787 
788 static acpi_status
789 processor_walk_namespace_cb(acpi_handle handle,
790 			    u32 lvl, void *context, void **rv)
791 {
792 	acpi_status status;
793 	int *action = context;
794 
795 	status = is_processor_device(handle);
796 	if (ACPI_FAILURE(status))
797 		return AE_OK;	/* not a processor; continue to walk */
798 
799 	switch (*action) {
800 	case INSTALL_NOTIFY_HANDLER:
801 		acpi_install_notify_handler(handle,
802 					    ACPI_SYSTEM_NOTIFY,
803 					    acpi_processor_hotplug_notify,
804 					    NULL);
805 		break;
806 	case UNINSTALL_NOTIFY_HANDLER:
807 		acpi_remove_notify_handler(handle,
808 					   ACPI_SYSTEM_NOTIFY,
809 					   acpi_processor_hotplug_notify);
810 		break;
811 	default:
812 		break;
813 	}
814 
815 	/* found a processor; skip walking underneath */
816 	return AE_CTRL_DEPTH;
817 }
818 
819 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
820 {
821 	acpi_handle handle = pr->handle;
822 
823 	if (!is_processor_present(handle)) {
824 		return AE_ERROR;
825 	}
826 
827 	if (acpi_map_lsapic(handle, &pr->id))
828 		return AE_ERROR;
829 
830 	if (arch_register_cpu(pr->id)) {
831 		acpi_unmap_lsapic(pr->id);
832 		return AE_ERROR;
833 	}
834 
835 	/* CPU got hot-plugged, but cpu_data is not initialized yet
836 	 * Set flag to delay cpu_idle/throttling initialization
837 	 * in:
838 	 * acpi_processor_add()
839 	 *   acpi_processor_get_info()
840 	 * and do it when the CPU gets online the first time
841 	 * TBD: Cleanup above functions and try to do this more elegant.
842 	 */
843 	printk(KERN_INFO "CPU %d got hotplugged\n", pr->id);
844 	pr->flags.need_hotplug_init = 1;
845 
846 	return AE_OK;
847 }
848 
849 static int acpi_processor_handle_eject(struct acpi_processor *pr)
850 {
851 	if (cpu_online(pr->id))
852 		cpu_down(pr->id);
853 
854 	arch_unregister_cpu(pr->id);
855 	acpi_unmap_lsapic(pr->id);
856 	return (0);
857 }
858 #else
859 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
860 {
861 	return AE_ERROR;
862 }
863 static int acpi_processor_handle_eject(struct acpi_processor *pr)
864 {
865 	return (-EINVAL);
866 }
867 #endif
868 
869 static
870 void acpi_processor_install_hotplug_notify(void)
871 {
872 #ifdef CONFIG_ACPI_HOTPLUG_CPU
873 	int action = INSTALL_NOTIFY_HANDLER;
874 	acpi_walk_namespace(ACPI_TYPE_ANY,
875 			    ACPI_ROOT_OBJECT,
876 			    ACPI_UINT32_MAX,
877 			    processor_walk_namespace_cb, NULL, &action, NULL);
878 #endif
879 	register_hotcpu_notifier(&acpi_cpu_notifier);
880 }
881 
882 static
883 void acpi_processor_uninstall_hotplug_notify(void)
884 {
885 #ifdef CONFIG_ACPI_HOTPLUG_CPU
886 	int action = UNINSTALL_NOTIFY_HANDLER;
887 	acpi_walk_namespace(ACPI_TYPE_ANY,
888 			    ACPI_ROOT_OBJECT,
889 			    ACPI_UINT32_MAX,
890 			    processor_walk_namespace_cb, NULL, &action, NULL);
891 #endif
892 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
893 }
894 
895 /*
896  * We keep the driver loaded even when ACPI is not running.
897  * This is needed for the powernow-k8 driver, that works even without
898  * ACPI, but needs symbols from this driver
899  */
900 
901 static int __init acpi_processor_init(void)
902 {
903 	int result = 0;
904 
905 	if (acpi_disabled)
906 		return 0;
907 
908 	memset(&errata, 0, sizeof(errata));
909 
910 	result = acpi_bus_register_driver(&acpi_processor_driver);
911 	if (result < 0)
912 		return result;
913 
914 	acpi_processor_install_hotplug_notify();
915 
916 	acpi_thermal_cpufreq_init();
917 
918 	acpi_processor_ppc_init();
919 
920 	acpi_processor_throttling_init();
921 
922 	return 0;
923 }
924 
925 static void __exit acpi_processor_exit(void)
926 {
927 	if (acpi_disabled)
928 		return;
929 
930 	acpi_processor_ppc_exit();
931 
932 	acpi_thermal_cpufreq_exit();
933 
934 	acpi_processor_uninstall_hotplug_notify();
935 
936 	acpi_bus_unregister_driver(&acpi_processor_driver);
937 
938 	return;
939 }
940 
941 module_init(acpi_processor_init);
942 module_exit(acpi_processor_exit);
943 
944 MODULE_ALIAS("processor");
945