xref: /openbmc/linux/drivers/acpi/processor_driver.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 #ifdef CONFIG_ACPI_PROCFS
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #endif
47 #include <linux/dmi.h>
48 #include <linux/moduleparam.h>
49 #include <linux/cpuidle.h>
50 #include <linux/slab.h>
51 
52 #include <asm/io.h>
53 #include <asm/system.h>
54 #include <asm/cpu.h>
55 #include <asm/delay.h>
56 #include <asm/uaccess.h>
57 #include <asm/processor.h>
58 #include <asm/smp.h>
59 #include <asm/acpi.h>
60 
61 #include <acpi/acpi_bus.h>
62 #include <acpi/acpi_drivers.h>
63 #include <acpi/processor.h>
64 
65 #define PREFIX "ACPI: "
66 
67 #define ACPI_PROCESSOR_CLASS		"processor"
68 #define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
69 #define ACPI_PROCESSOR_FILE_INFO	"info"
70 #define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
71 #define ACPI_PROCESSOR_FILE_LIMIT	"limit"
72 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
73 #define ACPI_PROCESSOR_NOTIFY_POWER	0x81
74 #define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82
75 
76 #define ACPI_PROCESSOR_LIMIT_USER	0
77 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
78 
79 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
80 ACPI_MODULE_NAME("processor_driver");
81 
82 MODULE_AUTHOR("Paul Diefenbaugh");
83 MODULE_DESCRIPTION("ACPI Processor Driver");
84 MODULE_LICENSE("GPL");
85 
86 static int acpi_processor_add(struct acpi_device *device);
87 static int acpi_processor_remove(struct acpi_device *device, int type);
88 static void acpi_processor_notify(struct acpi_device *device, u32 event);
89 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
90 static int acpi_processor_handle_eject(struct acpi_processor *pr);
91 
92 
93 static const struct acpi_device_id processor_device_ids[] = {
94 	{ACPI_PROCESSOR_OBJECT_HID, 0},
95 	{"ACPI0007", 0},
96 	{"", 0},
97 };
98 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
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 		.suspend = acpi_processor_suspend,
108 		.resume = acpi_processor_resume,
109 		.notify = acpi_processor_notify,
110 		},
111 };
112 
113 #define INSTALL_NOTIFY_HANDLER		1
114 #define UNINSTALL_NOTIFY_HANDLER	2
115 
116 DEFINE_PER_CPU(struct acpi_processor *, processors);
117 EXPORT_PER_CPU_SYMBOL(processors);
118 
119 struct acpi_processor_errata errata __read_mostly;
120 
121 /* --------------------------------------------------------------------------
122                                 Errata Handling
123    -------------------------------------------------------------------------- */
124 
125 static int acpi_processor_errata_piix4(struct pci_dev *dev)
126 {
127 	u8 value1 = 0;
128 	u8 value2 = 0;
129 
130 
131 	if (!dev)
132 		return -EINVAL;
133 
134 	/*
135 	 * Note that 'dev' references the PIIX4 ACPI Controller.
136 	 */
137 
138 	switch (dev->revision) {
139 	case 0:
140 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
141 		break;
142 	case 1:
143 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
144 		break;
145 	case 2:
146 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
147 		break;
148 	case 3:
149 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
150 		break;
151 	default:
152 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
153 		break;
154 	}
155 
156 	switch (dev->revision) {
157 
158 	case 0:		/* PIIX4 A-step */
159 	case 1:		/* PIIX4 B-step */
160 		/*
161 		 * See specification changes #13 ("Manual Throttle Duty Cycle")
162 		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
163 		 * erratum #5 ("STPCLK# Deassertion Time") from the January
164 		 * 2002 PIIX4 specification update.  Applies to only older
165 		 * PIIX4 models.
166 		 */
167 		errata.piix4.throttle = 1;
168 
169 	case 2:		/* PIIX4E */
170 	case 3:		/* PIIX4M */
171 		/*
172 		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
173 		 * Livelock") from the January 2002 PIIX4 specification update.
174 		 * Applies to all PIIX4 models.
175 		 */
176 
177 		/*
178 		 * BM-IDE
179 		 * ------
180 		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
181 		 * Status register address.  We'll use this later to read
182 		 * each IDE controller's DMA status to make sure we catch all
183 		 * DMA activity.
184 		 */
185 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
186 				     PCI_DEVICE_ID_INTEL_82371AB,
187 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
188 		if (dev) {
189 			errata.piix4.bmisx = pci_resource_start(dev, 4);
190 			pci_dev_put(dev);
191 		}
192 
193 		/*
194 		 * Type-F DMA
195 		 * ----------
196 		 * Find the PIIX4 ISA Controller and read the Motherboard
197 		 * DMA controller's status to see if Type-F (Fast) DMA mode
198 		 * is enabled (bit 7) on either channel.  Note that we'll
199 		 * disable C3 support if this is enabled, as some legacy
200 		 * devices won't operate well if fast DMA is disabled.
201 		 */
202 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
203 				     PCI_DEVICE_ID_INTEL_82371AB_0,
204 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
205 		if (dev) {
206 			pci_read_config_byte(dev, 0x76, &value1);
207 			pci_read_config_byte(dev, 0x77, &value2);
208 			if ((value1 & 0x80) || (value2 & 0x80))
209 				errata.piix4.fdma = 1;
210 			pci_dev_put(dev);
211 		}
212 
213 		break;
214 	}
215 
216 	if (errata.piix4.bmisx)
217 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
218 				  "Bus master activity detection (BM-IDE) erratum enabled\n"));
219 	if (errata.piix4.fdma)
220 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
221 				  "Type-F DMA livelock erratum (C3 disabled)\n"));
222 
223 	return 0;
224 }
225 
226 static int acpi_processor_errata(struct acpi_processor *pr)
227 {
228 	int result = 0;
229 	struct pci_dev *dev = NULL;
230 
231 
232 	if (!pr)
233 		return -EINVAL;
234 
235 	/*
236 	 * PIIX4
237 	 */
238 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
239 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
240 			     PCI_ANY_ID, NULL);
241 	if (dev) {
242 		result = acpi_processor_errata_piix4(dev);
243 		pci_dev_put(dev);
244 	}
245 
246 	return result;
247 }
248 
249 #ifdef CONFIG_ACPI_PROCFS
250 static struct proc_dir_entry *acpi_processor_dir = NULL;
251 
252 static int __cpuinit acpi_processor_add_fs(struct acpi_device *device)
253 {
254 	struct proc_dir_entry *entry = NULL;
255 
256 
257 	if (!acpi_device_dir(device)) {
258 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
259 						     acpi_processor_dir);
260 		if (!acpi_device_dir(device))
261 			return -ENODEV;
262 	}
263 
264 	/* 'throttling' [R/W] */
265 	entry = proc_create_data(ACPI_PROCESSOR_FILE_THROTTLING,
266 				 S_IFREG | S_IRUGO | S_IWUSR,
267 				 acpi_device_dir(device),
268 				 &acpi_processor_throttling_fops,
269 				 acpi_driver_data(device));
270 	if (!entry)
271 		return -EIO;
272 	return 0;
273 }
274 static int acpi_processor_remove_fs(struct acpi_device *device)
275 {
276 
277 	if (acpi_device_dir(device)) {
278 		remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
279 				  acpi_device_dir(device));
280 		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
281 		acpi_device_dir(device) = NULL;
282 	}
283 
284 	return 0;
285 }
286 #else
287 static inline int acpi_processor_add_fs(struct acpi_device *device)
288 {
289 	return 0;
290 }
291 static inline int acpi_processor_remove_fs(struct acpi_device *device)
292 {
293 	return 0;
294 }
295 #endif
296 /* --------------------------------------------------------------------------
297                                  Driver Interface
298    -------------------------------------------------------------------------- */
299 
300 static int acpi_processor_get_info(struct acpi_device *device)
301 {
302 	acpi_status status = 0;
303 	union acpi_object object = { 0 };
304 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
305 	struct acpi_processor *pr;
306 	int cpu_index, device_declaration = 0;
307 	static int cpu0_initialized;
308 
309 	pr = acpi_driver_data(device);
310 	if (!pr)
311 		return -EINVAL;
312 
313 	if (num_online_cpus() > 1)
314 		errata.smp = TRUE;
315 
316 	acpi_processor_errata(pr);
317 
318 	/*
319 	 * Check to see if we have bus mastering arbitration control.  This
320 	 * is required for proper C3 usage (to maintain cache coherency).
321 	 */
322 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
323 		pr->flags.bm_control = 1;
324 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
325 				  "Bus mastering arbitration control present\n"));
326 	} else
327 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
328 				  "No bus mastering arbitration control\n"));
329 
330 	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
331 		/* Declared with "Processor" statement; match ProcessorID */
332 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
333 		if (ACPI_FAILURE(status)) {
334 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
335 			return -ENODEV;
336 		}
337 
338 		/*
339 		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
340 		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
341 		 *      arch/xxx/acpi.c
342 		 */
343 		pr->acpi_id = object.processor.proc_id;
344 	} else {
345 		/*
346 		 * Declared with "Device" statement; match _UID.
347 		 * Note that we don't handle string _UIDs yet.
348 		 */
349 		unsigned long long value;
350 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
351 						NULL, &value);
352 		if (ACPI_FAILURE(status)) {
353 			printk(KERN_ERR PREFIX
354 			    "Evaluating processor _UID [%#x]\n", status);
355 			return -ENODEV;
356 		}
357 		device_declaration = 1;
358 		pr->acpi_id = value;
359 	}
360 	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
361 
362 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
363 	if (!cpu0_initialized && (cpu_index == -1) &&
364 	    (num_online_cpus() == 1)) {
365 		cpu_index = 0;
366 	}
367 
368 	cpu0_initialized = 1;
369 
370 	pr->id = cpu_index;
371 
372 	/*
373 	 *  Extra Processor objects may be enumerated on MP systems with
374 	 *  less than the max # of CPUs. They should be ignored _iff
375 	 *  they are physically not present.
376 	 */
377 	if (pr->id == -1) {
378 		if (ACPI_FAILURE
379 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
380 			return -ENODEV;
381 		}
382 	}
383 	/*
384 	 * On some boxes several processors use the same processor bus id.
385 	 * But they are located in different scope. For example:
386 	 * \_SB.SCK0.CPU0
387 	 * \_SB.SCK1.CPU0
388 	 * Rename the processor device bus id. And the new bus id will be
389 	 * generated as the following format:
390 	 * CPU+CPU ID.
391 	 */
392 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
393 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
394 			  pr->acpi_id));
395 
396 	if (!object.processor.pblk_address)
397 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
398 	else if (object.processor.pblk_length != 6)
399 		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
400 			    object.processor.pblk_length);
401 	else {
402 		pr->throttling.address = object.processor.pblk_address;
403 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
404 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
405 
406 		pr->pblk = object.processor.pblk_address;
407 
408 		/*
409 		 * We don't care about error returns - we just try to mark
410 		 * these reserved so that nobody else is confused into thinking
411 		 * that this region might be unused..
412 		 *
413 		 * (In particular, allocating the IO range for Cardbus)
414 		 */
415 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
416 	}
417 
418 	/*
419 	 * If ACPI describes a slot number for this CPU, we can use it
420 	 * ensure we get the right value in the "physical id" field
421 	 * of /proc/cpuinfo
422 	 */
423 	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
424 	if (ACPI_SUCCESS(status))
425 		arch_fix_phys_package_id(pr->id, object.integer.value);
426 
427 	return 0;
428 }
429 
430 static DEFINE_PER_CPU(void *, processor_device_array);
431 
432 static void acpi_processor_notify(struct acpi_device *device, u32 event)
433 {
434 	struct acpi_processor *pr = acpi_driver_data(device);
435 	int saved;
436 
437 	if (!pr)
438 		return;
439 
440 	switch (event) {
441 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
442 		saved = pr->performance_platform_limit;
443 		acpi_processor_ppc_has_changed(pr, 1);
444 		if (saved == pr->performance_platform_limit)
445 			break;
446 		acpi_bus_generate_proc_event(device, event,
447 					pr->performance_platform_limit);
448 		acpi_bus_generate_netlink_event(device->pnp.device_class,
449 						  dev_name(&device->dev), event,
450 						  pr->performance_platform_limit);
451 		break;
452 	case ACPI_PROCESSOR_NOTIFY_POWER:
453 		acpi_processor_cst_has_changed(pr);
454 		acpi_bus_generate_proc_event(device, event, 0);
455 		acpi_bus_generate_netlink_event(device->pnp.device_class,
456 						  dev_name(&device->dev), event, 0);
457 		break;
458 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
459 		acpi_processor_tstate_has_changed(pr);
460 		acpi_bus_generate_proc_event(device, event, 0);
461 		acpi_bus_generate_netlink_event(device->pnp.device_class,
462 						  dev_name(&device->dev), event, 0);
463 	default:
464 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
465 				  "Unsupported event [0x%x]\n", event));
466 		break;
467 	}
468 
469 	return;
470 }
471 
472 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
473 		unsigned long action, void *hcpu)
474 {
475 	unsigned int cpu = (unsigned long)hcpu;
476 	struct acpi_processor *pr = per_cpu(processors, cpu);
477 
478 	if (action == CPU_ONLINE && pr) {
479 		acpi_processor_ppc_has_changed(pr, 0);
480 		acpi_processor_cst_has_changed(pr);
481 		acpi_processor_tstate_has_changed(pr);
482 	}
483 	return NOTIFY_OK;
484 }
485 
486 static struct notifier_block acpi_cpu_notifier =
487 {
488 	    .notifier_call = acpi_cpu_soft_notify,
489 };
490 
491 static int __cpuinit acpi_processor_add(struct acpi_device *device)
492 {
493 	struct acpi_processor *pr = NULL;
494 	int result = 0;
495 	struct sys_device *sysdev;
496 
497 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
498 	if (!pr)
499 		return -ENOMEM;
500 
501 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
502 		kfree(pr);
503 		return -ENOMEM;
504 	}
505 
506 	pr->handle = device->handle;
507 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
508 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
509 	device->driver_data = pr;
510 
511 	result = acpi_processor_get_info(device);
512 	if (result) {
513 		/* Processor is physically not present */
514 		return 0;
515 	}
516 
517 #ifdef CONFIG_SMP
518 	if (pr->id >= setup_max_cpus && pr->id != 0)
519 		return 0;
520 #endif
521 
522 	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
523 
524 	/*
525 	 * Buggy BIOS check
526 	 * ACPI id of processors can be reported wrongly by the BIOS.
527 	 * Don't trust it blindly
528 	 */
529 	if (per_cpu(processor_device_array, pr->id) != NULL &&
530 	    per_cpu(processor_device_array, pr->id) != device) {
531 		printk(KERN_WARNING "BIOS reported wrong ACPI id "
532 			"for the processor\n");
533 		result = -ENODEV;
534 		goto err_free_cpumask;
535 	}
536 	per_cpu(processor_device_array, pr->id) = device;
537 
538 	per_cpu(processors, pr->id) = pr;
539 
540 	result = acpi_processor_add_fs(device);
541 	if (result)
542 		goto err_free_cpumask;
543 
544 	sysdev = get_cpu_sysdev(pr->id);
545 	if (sysfs_create_link(&device->dev.kobj, &sysdev->kobj, "sysdev")) {
546 		result = -EFAULT;
547 		goto err_remove_fs;
548 	}
549 
550 #ifdef CONFIG_CPU_FREQ
551 	acpi_processor_ppc_has_changed(pr, 0);
552 #endif
553 	acpi_processor_get_throttling_info(pr);
554 	acpi_processor_get_limit_info(pr);
555 
556 
557 	if (cpuidle_get_driver() == &acpi_idle_driver)
558 		acpi_processor_power_init(pr, device);
559 
560 	pr->cdev = thermal_cooling_device_register("Processor", device,
561 						&processor_cooling_ops);
562 	if (IS_ERR(pr->cdev)) {
563 		result = PTR_ERR(pr->cdev);
564 		goto err_power_exit;
565 	}
566 
567 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
568 		 pr->cdev->id);
569 
570 	result = sysfs_create_link(&device->dev.kobj,
571 				   &pr->cdev->device.kobj,
572 				   "thermal_cooling");
573 	if (result) {
574 		printk(KERN_ERR PREFIX "Create sysfs link\n");
575 		goto err_thermal_unregister;
576 	}
577 	result = sysfs_create_link(&pr->cdev->device.kobj,
578 				   &device->dev.kobj,
579 				   "device");
580 	if (result) {
581 		printk(KERN_ERR PREFIX "Create sysfs link\n");
582 		goto err_remove_sysfs;
583 	}
584 
585 	return 0;
586 
587 err_remove_sysfs:
588 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
589 err_thermal_unregister:
590 	thermal_cooling_device_unregister(pr->cdev);
591 err_power_exit:
592 	acpi_processor_power_exit(pr, device);
593 err_remove_fs:
594 	acpi_processor_remove_fs(device);
595 err_free_cpumask:
596 	free_cpumask_var(pr->throttling.shared_cpu_map);
597 
598 	return result;
599 }
600 
601 static int acpi_processor_remove(struct acpi_device *device, int type)
602 {
603 	struct acpi_processor *pr = NULL;
604 
605 
606 	if (!device || !acpi_driver_data(device))
607 		return -EINVAL;
608 
609 	pr = acpi_driver_data(device);
610 
611 	if (pr->id >= nr_cpu_ids)
612 		goto free;
613 
614 	if (type == ACPI_BUS_REMOVAL_EJECT) {
615 		if (acpi_processor_handle_eject(pr))
616 			return -EINVAL;
617 	}
618 
619 	acpi_processor_power_exit(pr, device);
620 
621 	sysfs_remove_link(&device->dev.kobj, "sysdev");
622 
623 	acpi_processor_remove_fs(device);
624 
625 	if (pr->cdev) {
626 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
627 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
628 		thermal_cooling_device_unregister(pr->cdev);
629 		pr->cdev = NULL;
630 	}
631 
632 	per_cpu(processors, pr->id) = NULL;
633 	per_cpu(processor_device_array, pr->id) = NULL;
634 
635 free:
636 	free_cpumask_var(pr->throttling.shared_cpu_map);
637 	kfree(pr);
638 
639 	return 0;
640 }
641 
642 #ifdef CONFIG_ACPI_HOTPLUG_CPU
643 /****************************************************************************
644  * 	Acpi processor hotplug support 				       	    *
645  ****************************************************************************/
646 
647 static int is_processor_present(acpi_handle handle)
648 {
649 	acpi_status status;
650 	unsigned long long sta = 0;
651 
652 
653 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
654 
655 	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
656 		return 1;
657 
658 	/*
659 	 * _STA is mandatory for a processor that supports hot plug
660 	 */
661 	if (status == AE_NOT_FOUND)
662 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
663 				"Processor does not support hot plug\n"));
664 	else
665 		ACPI_EXCEPTION((AE_INFO, status,
666 				"Processor Device is not present"));
667 	return 0;
668 }
669 
670 static
671 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
672 {
673 	acpi_handle phandle;
674 	struct acpi_device *pdev;
675 
676 
677 	if (acpi_get_parent(handle, &phandle)) {
678 		return -ENODEV;
679 	}
680 
681 	if (acpi_bus_get_device(phandle, &pdev)) {
682 		return -ENODEV;
683 	}
684 
685 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
686 		return -ENODEV;
687 	}
688 
689 	return 0;
690 }
691 
692 static void __ref acpi_processor_hotplug_notify(acpi_handle handle,
693 						u32 event, void *data)
694 {
695 	struct acpi_processor *pr;
696 	struct acpi_device *device = NULL;
697 	int result;
698 
699 
700 	switch (event) {
701 	case ACPI_NOTIFY_BUS_CHECK:
702 	case ACPI_NOTIFY_DEVICE_CHECK:
703 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
704 		"Processor driver received %s event\n",
705 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
706 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
707 
708 		if (!is_processor_present(handle))
709 			break;
710 
711 		if (acpi_bus_get_device(handle, &device)) {
712 			result = acpi_processor_device_add(handle, &device);
713 			if (result)
714 				printk(KERN_ERR PREFIX
715 					    "Unable to add the device\n");
716 			break;
717 		}
718 		break;
719 	case ACPI_NOTIFY_EJECT_REQUEST:
720 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
721 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
722 
723 		if (acpi_bus_get_device(handle, &device)) {
724 			printk(KERN_ERR PREFIX
725 				    "Device don't exist, dropping EJECT\n");
726 			break;
727 		}
728 		pr = acpi_driver_data(device);
729 		if (!pr) {
730 			printk(KERN_ERR PREFIX
731 				    "Driver data is NULL, dropping EJECT\n");
732 			return;
733 		}
734 		break;
735 	default:
736 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
737 				  "Unsupported event [0x%x]\n", event));
738 		break;
739 	}
740 
741 	return;
742 }
743 
744 static acpi_status
745 processor_walk_namespace_cb(acpi_handle handle,
746 			    u32 lvl, void *context, void **rv)
747 {
748 	acpi_status status;
749 	int *action = context;
750 	acpi_object_type type = 0;
751 
752 	status = acpi_get_type(handle, &type);
753 	if (ACPI_FAILURE(status))
754 		return (AE_OK);
755 
756 	if (type != ACPI_TYPE_PROCESSOR)
757 		return (AE_OK);
758 
759 	switch (*action) {
760 	case INSTALL_NOTIFY_HANDLER:
761 		acpi_install_notify_handler(handle,
762 					    ACPI_SYSTEM_NOTIFY,
763 					    acpi_processor_hotplug_notify,
764 					    NULL);
765 		break;
766 	case UNINSTALL_NOTIFY_HANDLER:
767 		acpi_remove_notify_handler(handle,
768 					   ACPI_SYSTEM_NOTIFY,
769 					   acpi_processor_hotplug_notify);
770 		break;
771 	default:
772 		break;
773 	}
774 
775 	return (AE_OK);
776 }
777 
778 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
779 {
780 
781 	if (!is_processor_present(handle)) {
782 		return AE_ERROR;
783 	}
784 
785 	if (acpi_map_lsapic(handle, p_cpu))
786 		return AE_ERROR;
787 
788 	if (arch_register_cpu(*p_cpu)) {
789 		acpi_unmap_lsapic(*p_cpu);
790 		return AE_ERROR;
791 	}
792 
793 	return AE_OK;
794 }
795 
796 static int acpi_processor_handle_eject(struct acpi_processor *pr)
797 {
798 	if (cpu_online(pr->id))
799 		cpu_down(pr->id);
800 
801 	arch_unregister_cpu(pr->id);
802 	acpi_unmap_lsapic(pr->id);
803 	return (0);
804 }
805 #else
806 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
807 {
808 	return AE_ERROR;
809 }
810 static int acpi_processor_handle_eject(struct acpi_processor *pr)
811 {
812 	return (-EINVAL);
813 }
814 #endif
815 
816 static
817 void acpi_processor_install_hotplug_notify(void)
818 {
819 #ifdef CONFIG_ACPI_HOTPLUG_CPU
820 	int action = INSTALL_NOTIFY_HANDLER;
821 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
822 			    ACPI_ROOT_OBJECT,
823 			    ACPI_UINT32_MAX,
824 			    processor_walk_namespace_cb, NULL, &action, NULL);
825 #endif
826 	register_hotcpu_notifier(&acpi_cpu_notifier);
827 }
828 
829 static
830 void acpi_processor_uninstall_hotplug_notify(void)
831 {
832 #ifdef CONFIG_ACPI_HOTPLUG_CPU
833 	int action = UNINSTALL_NOTIFY_HANDLER;
834 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
835 			    ACPI_ROOT_OBJECT,
836 			    ACPI_UINT32_MAX,
837 			    processor_walk_namespace_cb, NULL, &action, NULL);
838 #endif
839 	unregister_hotcpu_notifier(&acpi_cpu_notifier);
840 }
841 
842 /*
843  * We keep the driver loaded even when ACPI is not running.
844  * This is needed for the powernow-k8 driver, that works even without
845  * ACPI, but needs symbols from this driver
846  */
847 
848 static int __init acpi_processor_init(void)
849 {
850 	int result = 0;
851 
852 	if (acpi_disabled)
853 		return 0;
854 
855 	memset(&errata, 0, sizeof(errata));
856 
857 #ifdef CONFIG_ACPI_PROCFS
858 	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
859 	if (!acpi_processor_dir)
860 		return -ENOMEM;
861 #endif
862 
863 	if (!cpuidle_register_driver(&acpi_idle_driver)) {
864 		printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
865 			acpi_idle_driver.name);
866 	} else {
867 		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s\n",
868 			cpuidle_get_driver()->name);
869 	}
870 
871 	result = acpi_bus_register_driver(&acpi_processor_driver);
872 	if (result < 0)
873 		goto out_cpuidle;
874 
875 	acpi_processor_install_hotplug_notify();
876 
877 	acpi_thermal_cpufreq_init();
878 
879 	acpi_processor_ppc_init();
880 
881 	acpi_processor_throttling_init();
882 
883 	return 0;
884 
885 out_cpuidle:
886 	cpuidle_unregister_driver(&acpi_idle_driver);
887 
888 #ifdef CONFIG_ACPI_PROCFS
889 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
890 #endif
891 
892 	return result;
893 }
894 
895 static void __exit acpi_processor_exit(void)
896 {
897 	if (acpi_disabled)
898 		return;
899 
900 	acpi_processor_ppc_exit();
901 
902 	acpi_thermal_cpufreq_exit();
903 
904 	acpi_processor_uninstall_hotplug_notify();
905 
906 	acpi_bus_unregister_driver(&acpi_processor_driver);
907 
908 	cpuidle_unregister_driver(&acpi_idle_driver);
909 
910 #ifdef CONFIG_ACPI_PROCFS
911 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
912 #endif
913 
914 	return;
915 }
916 
917 module_init(acpi_processor_init);
918 module_exit(acpi_processor_exit);
919 
920 MODULE_ALIAS("processor");
921