xref: /linux/drivers/acpi/processor_core.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
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 
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 ACPI_PROCESSOR_COMPONENT	0x01000000
62 #define ACPI_PROCESSOR_CLASS		"processor"
63 #define ACPI_PROCESSOR_DRIVER_NAME	"ACPI Processor Driver"
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 
71 #define ACPI_PROCESSOR_LIMIT_USER	0
72 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
73 
74 #define ACPI_STA_PRESENT 0x00000001
75 
76 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
77 ACPI_MODULE_NAME("acpi_processor")
78 
79     MODULE_AUTHOR("Paul Diefenbaugh");
80 MODULE_DESCRIPTION(ACPI_PROCESSOR_DRIVER_NAME);
81 MODULE_LICENSE("GPL");
82 
83 static int acpi_processor_add(struct acpi_device *device);
84 static int acpi_processor_start(struct acpi_device *device);
85 static int acpi_processor_remove(struct acpi_device *device, int type);
86 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file);
87 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data);
88 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
89 static int acpi_processor_handle_eject(struct acpi_processor *pr);
90 
91 static struct acpi_driver acpi_processor_driver = {
92 	.name = ACPI_PROCESSOR_DRIVER_NAME,
93 	.class = ACPI_PROCESSOR_CLASS,
94 	.ids = ACPI_PROCESSOR_HID,
95 	.ops = {
96 		.add = acpi_processor_add,
97 		.remove = acpi_processor_remove,
98 		.start = acpi_processor_start,
99 		},
100 };
101 
102 #define INSTALL_NOTIFY_HANDLER		1
103 #define UNINSTALL_NOTIFY_HANDLER	2
104 
105 static struct file_operations acpi_processor_info_fops = {
106 	.open = acpi_processor_info_open_fs,
107 	.read = seq_read,
108 	.llseek = seq_lseek,
109 	.release = single_release,
110 };
111 
112 struct acpi_processor *processors[NR_CPUS];
113 struct acpi_processor_errata errata;
114 
115 /* --------------------------------------------------------------------------
116                                 Errata Handling
117    -------------------------------------------------------------------------- */
118 
119 static int acpi_processor_errata_piix4(struct pci_dev *dev)
120 {
121 	u8 rev = 0;
122 	u8 value1 = 0;
123 	u8 value2 = 0;
124 
125 	ACPI_FUNCTION_TRACE("acpi_processor_errata_piix4");
126 
127 	if (!dev)
128 		return_VALUE(-EINVAL);
129 
130 	/*
131 	 * Note that 'dev' references the PIIX4 ACPI Controller.
132 	 */
133 
134 	pci_read_config_byte(dev, PCI_REVISION_ID, &rev);
135 
136 	switch (rev) {
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 (rev) {
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_VALUE(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 	ACPI_FUNCTION_TRACE("acpi_processor_errata");
230 
231 	if (!pr)
232 		return_VALUE(-EINVAL);
233 
234 	/*
235 	 * PIIX4
236 	 */
237 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
238 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
239 			     PCI_ANY_ID, NULL);
240 	if (dev) {
241 		result = acpi_processor_errata_piix4(dev);
242 		pci_dev_put(dev);
243 	}
244 
245 	return_VALUE(result);
246 }
247 
248 /* --------------------------------------------------------------------------
249                               Common ACPI processor fucntions
250    -------------------------------------------------------------------------- */
251 
252 /*
253  * _PDC is required for a BIOS-OS handshake for most of the newer
254  * ACPI processor features.
255  */
256 
257 int acpi_processor_set_pdc(struct acpi_processor *pr,
258 			   struct acpi_object_list *pdc_in)
259 {
260 	acpi_status status = AE_OK;
261 	u32 arg0_buf[3];
262 	union acpi_object arg0 = { ACPI_TYPE_BUFFER };
263 	struct acpi_object_list no_object = { 1, &arg0 };
264 	struct acpi_object_list *pdc;
265 
266 	ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
267 
268 	arg0.buffer.length = 12;
269 	arg0.buffer.pointer = (u8 *) arg0_buf;
270 	arg0_buf[0] = ACPI_PDC_REVISION_ID;
271 	arg0_buf[1] = 0;
272 	arg0_buf[2] = 0;
273 
274 	pdc = (pdc_in) ? pdc_in : &no_object;
275 
276 	status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
277 
278 	if ((ACPI_FAILURE(status)) && (pdc_in))
279 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
280 				  "Error evaluating _PDC, using legacy perf. control...\n"));
281 
282 	return_VALUE(status);
283 }
284 
285 /* --------------------------------------------------------------------------
286                               FS Interface (/proc)
287    -------------------------------------------------------------------------- */
288 
289 static struct proc_dir_entry *acpi_processor_dir = NULL;
290 
291 static int acpi_processor_info_seq_show(struct seq_file *seq, void *offset)
292 {
293 	struct acpi_processor *pr = (struct acpi_processor *)seq->private;
294 
295 	ACPI_FUNCTION_TRACE("acpi_processor_info_seq_show");
296 
297 	if (!pr)
298 		goto end;
299 
300 	seq_printf(seq, "processor id:            %d\n"
301 		   "acpi id:                 %d\n"
302 		   "bus mastering control:   %s\n"
303 		   "power management:        %s\n"
304 		   "throttling control:      %s\n"
305 		   "limit interface:         %s\n",
306 		   pr->id,
307 		   pr->acpi_id,
308 		   pr->flags.bm_control ? "yes" : "no",
309 		   pr->flags.power ? "yes" : "no",
310 		   pr->flags.throttling ? "yes" : "no",
311 		   pr->flags.limit ? "yes" : "no");
312 
313       end:
314 	return_VALUE(0);
315 }
316 
317 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
318 {
319 	return single_open(file, acpi_processor_info_seq_show,
320 			   PDE(inode)->data);
321 }
322 
323 static int acpi_processor_add_fs(struct acpi_device *device)
324 {
325 	struct proc_dir_entry *entry = NULL;
326 
327 	ACPI_FUNCTION_TRACE("acpi_processor_add_fs");
328 
329 	if (!acpi_device_dir(device)) {
330 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
331 						     acpi_processor_dir);
332 		if (!acpi_device_dir(device))
333 			return_VALUE(-ENODEV);
334 	}
335 	acpi_device_dir(device)->owner = THIS_MODULE;
336 
337 	/* 'info' [R] */
338 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_INFO,
339 				  S_IRUGO, acpi_device_dir(device));
340 	if (!entry)
341 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
342 				  "Unable to create '%s' fs entry\n",
343 				  ACPI_PROCESSOR_FILE_INFO));
344 	else {
345 		entry->proc_fops = &acpi_processor_info_fops;
346 		entry->data = acpi_driver_data(device);
347 		entry->owner = THIS_MODULE;
348 	}
349 
350 	/* 'throttling' [R/W] */
351 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
352 				  S_IFREG | S_IRUGO | S_IWUSR,
353 				  acpi_device_dir(device));
354 	if (!entry)
355 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
356 				  "Unable to create '%s' fs entry\n",
357 				  ACPI_PROCESSOR_FILE_THROTTLING));
358 	else {
359 		entry->proc_fops = &acpi_processor_throttling_fops;
360 		entry->proc_fops->write = acpi_processor_write_throttling;
361 		entry->data = acpi_driver_data(device);
362 		entry->owner = THIS_MODULE;
363 	}
364 
365 	/* 'limit' [R/W] */
366 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
367 				  S_IFREG | S_IRUGO | S_IWUSR,
368 				  acpi_device_dir(device));
369 	if (!entry)
370 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
371 				  "Unable to create '%s' fs entry\n",
372 				  ACPI_PROCESSOR_FILE_LIMIT));
373 	else {
374 		entry->proc_fops = &acpi_processor_limit_fops;
375 		entry->proc_fops->write = acpi_processor_write_limit;
376 		entry->data = acpi_driver_data(device);
377 		entry->owner = THIS_MODULE;
378 	}
379 
380 	return_VALUE(0);
381 }
382 
383 static int acpi_processor_remove_fs(struct acpi_device *device)
384 {
385 	ACPI_FUNCTION_TRACE("acpi_processor_remove_fs");
386 
387 	if (acpi_device_dir(device)) {
388 		remove_proc_entry(ACPI_PROCESSOR_FILE_INFO,
389 				  acpi_device_dir(device));
390 		remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
391 				  acpi_device_dir(device));
392 		remove_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
393 				  acpi_device_dir(device));
394 		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
395 		acpi_device_dir(device) = NULL;
396 	}
397 
398 	return_VALUE(0);
399 }
400 
401 /* Use the acpiid in MADT to map cpus in case of SMP */
402 #ifndef CONFIG_SMP
403 #define convert_acpiid_to_cpu(acpi_id) (0xff)
404 #else
405 
406 #ifdef CONFIG_IA64
407 #define arch_acpiid_to_apicid 	ia64_acpiid_to_sapicid
408 #define arch_cpu_to_apicid 	ia64_cpu_to_sapicid
409 #define ARCH_BAD_APICID		(0xffff)
410 #else
411 #define arch_acpiid_to_apicid 	x86_acpiid_to_apicid
412 #define arch_cpu_to_apicid 	x86_cpu_to_apicid
413 #define ARCH_BAD_APICID		(0xff)
414 #endif
415 
416 static u8 convert_acpiid_to_cpu(u8 acpi_id)
417 {
418 	u16 apic_id;
419 	int i;
420 
421 	apic_id = arch_acpiid_to_apicid[acpi_id];
422 	if (apic_id == ARCH_BAD_APICID)
423 		return -1;
424 
425 	for (i = 0; i < NR_CPUS; i++) {
426 		if (arch_cpu_to_apicid[i] == apic_id)
427 			return i;
428 	}
429 	return -1;
430 }
431 #endif
432 
433 /* --------------------------------------------------------------------------
434                                  Driver Interface
435    -------------------------------------------------------------------------- */
436 
437 static int acpi_processor_get_info(struct acpi_processor *pr)
438 {
439 	acpi_status status = 0;
440 	union acpi_object object = { 0 };
441 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
442 	u8 cpu_index;
443 	static int cpu0_initialized;
444 
445 	ACPI_FUNCTION_TRACE("acpi_processor_get_info");
446 
447 	if (!pr)
448 		return_VALUE(-EINVAL);
449 
450 	if (num_online_cpus() > 1)
451 		errata.smp = TRUE;
452 
453 	acpi_processor_errata(pr);
454 
455 	/*
456 	 * Check to see if we have bus mastering arbitration control.  This
457 	 * is required for proper C3 usage (to maintain cache coherency).
458 	 */
459 	if (acpi_fadt.V1_pm2_cnt_blk && acpi_fadt.pm2_cnt_len) {
460 		pr->flags.bm_control = 1;
461 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
462 				  "Bus mastering arbitration control present\n"));
463 	} else
464 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
465 				  "No bus mastering arbitration control\n"));
466 
467 	/*
468 	 * Evalute the processor object.  Note that it is common on SMP to
469 	 * have the first (boot) processor with a valid PBLK address while
470 	 * all others have a NULL address.
471 	 */
472 	status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
473 	if (ACPI_FAILURE(status)) {
474 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
475 				  "Error evaluating processor object\n"));
476 		return_VALUE(-ENODEV);
477 	}
478 
479 	/*
480 	 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
481 	 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in arch/xxx/acpi.c
482 	 */
483 	pr->acpi_id = object.processor.proc_id;
484 
485 	cpu_index = convert_acpiid_to_cpu(pr->acpi_id);
486 
487 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
488 	if (!cpu0_initialized && (cpu_index == 0xff) &&
489 	    (num_online_cpus() == 1)) {
490 		cpu_index = 0;
491 	}
492 
493 	cpu0_initialized = 1;
494 
495 	pr->id = cpu_index;
496 
497 	/*
498 	 *  Extra Processor objects may be enumerated on MP systems with
499 	 *  less than the max # of CPUs. They should be ignored _iff
500 	 *  they are physically not present.
501 	 */
502 	if (cpu_index >= NR_CPUS) {
503 		if (ACPI_FAILURE
504 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
505 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
506 					  "Error getting cpuindex for acpiid 0x%x\n",
507 					  pr->acpi_id));
508 			return_VALUE(-ENODEV);
509 		}
510 	}
511 
512 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
513 			  pr->acpi_id));
514 
515 	if (!object.processor.pblk_address)
516 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
517 	else if (object.processor.pblk_length != 6)
518 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid PBLK length [%d]\n",
519 				  object.processor.pblk_length));
520 	else {
521 		pr->throttling.address = object.processor.pblk_address;
522 		pr->throttling.duty_offset = acpi_fadt.duty_offset;
523 		pr->throttling.duty_width = acpi_fadt.duty_width;
524 
525 		pr->pblk = object.processor.pblk_address;
526 
527 		/*
528 		 * We don't care about error returns - we just try to mark
529 		 * these reserved so that nobody else is confused into thinking
530 		 * that this region might be unused..
531 		 *
532 		 * (In particular, allocating the IO range for Cardbus)
533 		 */
534 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
535 	}
536 
537 #ifdef CONFIG_CPU_FREQ
538 	acpi_processor_ppc_has_changed(pr);
539 #endif
540 	acpi_processor_get_throttling_info(pr);
541 	acpi_processor_get_limit_info(pr);
542 
543 	return_VALUE(0);
544 }
545 
546 static int acpi_processor_start(struct acpi_device *device)
547 {
548 	int result = 0;
549 	acpi_status status = AE_OK;
550 	struct acpi_processor *pr;
551 
552 	ACPI_FUNCTION_TRACE("acpi_processor_start");
553 
554 	pr = acpi_driver_data(device);
555 
556 	result = acpi_processor_get_info(pr);
557 	if (result) {
558 		/* Processor is physically not present */
559 		return_VALUE(0);
560 	}
561 
562 	BUG_ON((pr->id >= NR_CPUS) || (pr->id < 0));
563 
564 	processors[pr->id] = pr;
565 
566 	result = acpi_processor_add_fs(device);
567 	if (result)
568 		goto end;
569 
570 	status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
571 					     acpi_processor_notify, pr);
572 	if (ACPI_FAILURE(status)) {
573 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
574 				  "Error installing device notify handler\n"));
575 	}
576 
577 	acpi_processor_power_init(pr, device);
578 
579 	if (pr->flags.throttling) {
580 		printk(KERN_INFO PREFIX "%s [%s] (supports",
581 		       acpi_device_name(device), acpi_device_bid(device));
582 		printk(" %d throttling states", pr->throttling.state_count);
583 		printk(")\n");
584 	}
585 
586       end:
587 
588 	return_VALUE(result);
589 }
590 
591 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
592 {
593 	struct acpi_processor *pr = (struct acpi_processor *)data;
594 	struct acpi_device *device = NULL;
595 
596 	ACPI_FUNCTION_TRACE("acpi_processor_notify");
597 
598 	if (!pr)
599 		return_VOID;
600 
601 	if (acpi_bus_get_device(pr->handle, &device))
602 		return_VOID;
603 
604 	switch (event) {
605 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
606 		acpi_processor_ppc_has_changed(pr);
607 		acpi_bus_generate_event(device, event,
608 					pr->performance_platform_limit);
609 		break;
610 	case ACPI_PROCESSOR_NOTIFY_POWER:
611 		acpi_processor_cst_has_changed(pr);
612 		acpi_bus_generate_event(device, event, 0);
613 		break;
614 	default:
615 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
616 				  "Unsupported event [0x%x]\n", event));
617 		break;
618 	}
619 
620 	return_VOID;
621 }
622 
623 static int acpi_processor_add(struct acpi_device *device)
624 {
625 	struct acpi_processor *pr = NULL;
626 
627 	ACPI_FUNCTION_TRACE("acpi_processor_add");
628 
629 	if (!device)
630 		return_VALUE(-EINVAL);
631 
632 	pr = kmalloc(sizeof(struct acpi_processor), GFP_KERNEL);
633 	if (!pr)
634 		return_VALUE(-ENOMEM);
635 	memset(pr, 0, sizeof(struct acpi_processor));
636 
637 	pr->handle = device->handle;
638 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
639 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
640 	acpi_driver_data(device) = pr;
641 
642 	return_VALUE(0);
643 }
644 
645 static int acpi_processor_remove(struct acpi_device *device, int type)
646 {
647 	acpi_status status = AE_OK;
648 	struct acpi_processor *pr = NULL;
649 
650 	ACPI_FUNCTION_TRACE("acpi_processor_remove");
651 
652 	if (!device || !acpi_driver_data(device))
653 		return_VALUE(-EINVAL);
654 
655 	pr = (struct acpi_processor *)acpi_driver_data(device);
656 
657 	if (pr->id >= NR_CPUS) {
658 		kfree(pr);
659 		return_VALUE(0);
660 	}
661 
662 	if (type == ACPI_BUS_REMOVAL_EJECT) {
663 		if (acpi_processor_handle_eject(pr))
664 			return_VALUE(-EINVAL);
665 	}
666 
667 	acpi_processor_power_exit(pr, device);
668 
669 	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
670 					    acpi_processor_notify);
671 	if (ACPI_FAILURE(status)) {
672 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
673 				  "Error removing notify handler\n"));
674 	}
675 
676 	acpi_processor_remove_fs(device);
677 
678 	processors[pr->id] = NULL;
679 
680 	kfree(pr);
681 
682 	return_VALUE(0);
683 }
684 
685 #ifdef CONFIG_ACPI_HOTPLUG_CPU
686 /****************************************************************************
687  * 	Acpi processor hotplug support 				       	    *
688  ****************************************************************************/
689 
690 static int is_processor_present(acpi_handle handle);
691 
692 static int is_processor_present(acpi_handle handle)
693 {
694 	acpi_status status;
695 	unsigned long sta = 0;
696 
697 	ACPI_FUNCTION_TRACE("is_processor_present");
698 
699 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
700 	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_PRESENT)) {
701 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
702 				  "Processor Device is not present\n"));
703 		return_VALUE(0);
704 	}
705 	return_VALUE(1);
706 }
707 
708 static
709 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
710 {
711 	acpi_handle phandle;
712 	struct acpi_device *pdev;
713 	struct acpi_processor *pr;
714 
715 	ACPI_FUNCTION_TRACE("acpi_processor_device_add");
716 
717 	if (acpi_get_parent(handle, &phandle)) {
718 		return_VALUE(-ENODEV);
719 	}
720 
721 	if (acpi_bus_get_device(phandle, &pdev)) {
722 		return_VALUE(-ENODEV);
723 	}
724 
725 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
726 		return_VALUE(-ENODEV);
727 	}
728 
729 	acpi_bus_start(*device);
730 
731 	pr = acpi_driver_data(*device);
732 	if (!pr)
733 		return_VALUE(-ENODEV);
734 
735 	if ((pr->id >= 0) && (pr->id < NR_CPUS)) {
736 		kobject_hotplug(&(*device)->kobj, KOBJ_ONLINE);
737 	}
738 	return_VALUE(0);
739 }
740 
741 static void
742 acpi_processor_hotplug_notify(acpi_handle handle, u32 event, void *data)
743 {
744 	struct acpi_processor *pr;
745 	struct acpi_device *device = NULL;
746 	int result;
747 
748 	ACPI_FUNCTION_TRACE("acpi_processor_hotplug_notify");
749 
750 	switch (event) {
751 	case ACPI_NOTIFY_BUS_CHECK:
752 	case ACPI_NOTIFY_DEVICE_CHECK:
753 		printk("Processor driver received %s event\n",
754 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
755 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
756 
757 		if (!is_processor_present(handle))
758 			break;
759 
760 		if (acpi_bus_get_device(handle, &device)) {
761 			result = acpi_processor_device_add(handle, &device);
762 			if (result)
763 				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
764 						  "Unable to add the device\n"));
765 			break;
766 		}
767 
768 		pr = acpi_driver_data(device);
769 		if (!pr) {
770 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
771 					  "Driver data is NULL\n"));
772 			break;
773 		}
774 
775 		if (pr->id >= 0 && (pr->id < NR_CPUS)) {
776 			kobject_hotplug(&device->kobj, KOBJ_OFFLINE);
777 			break;
778 		}
779 
780 		result = acpi_processor_start(device);
781 		if ((!result) && ((pr->id >= 0) && (pr->id < NR_CPUS))) {
782 			kobject_hotplug(&device->kobj, KOBJ_ONLINE);
783 		} else {
784 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
785 					  "Device [%s] failed to start\n",
786 					  acpi_device_bid(device)));
787 		}
788 		break;
789 	case ACPI_NOTIFY_EJECT_REQUEST:
790 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
791 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
792 
793 		if (acpi_bus_get_device(handle, &device)) {
794 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
795 					  "Device don't exist, dropping EJECT\n"));
796 			break;
797 		}
798 		pr = acpi_driver_data(device);
799 		if (!pr) {
800 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
801 					  "Driver data is NULL, dropping EJECT\n"));
802 			return_VOID;
803 		}
804 
805 		if ((pr->id < NR_CPUS) && (cpu_present(pr->id)))
806 			kobject_hotplug(&device->kobj, KOBJ_OFFLINE);
807 		break;
808 	default:
809 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
810 				  "Unsupported event [0x%x]\n", event));
811 		break;
812 	}
813 
814 	return_VOID;
815 }
816 
817 static acpi_status
818 processor_walk_namespace_cb(acpi_handle handle,
819 			    u32 lvl, void *context, void **rv)
820 {
821 	acpi_status status;
822 	int *action = context;
823 	acpi_object_type type = 0;
824 
825 	status = acpi_get_type(handle, &type);
826 	if (ACPI_FAILURE(status))
827 		return (AE_OK);
828 
829 	if (type != ACPI_TYPE_PROCESSOR)
830 		return (AE_OK);
831 
832 	switch (*action) {
833 	case INSTALL_NOTIFY_HANDLER:
834 		acpi_install_notify_handler(handle,
835 					    ACPI_SYSTEM_NOTIFY,
836 					    acpi_processor_hotplug_notify,
837 					    NULL);
838 		break;
839 	case UNINSTALL_NOTIFY_HANDLER:
840 		acpi_remove_notify_handler(handle,
841 					   ACPI_SYSTEM_NOTIFY,
842 					   acpi_processor_hotplug_notify);
843 		break;
844 	default:
845 		break;
846 	}
847 
848 	return (AE_OK);
849 }
850 
851 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
852 {
853 	ACPI_FUNCTION_TRACE("acpi_processor_hotadd_init");
854 
855 	if (!is_processor_present(handle)) {
856 		return_VALUE(AE_ERROR);
857 	}
858 
859 	if (acpi_map_lsapic(handle, p_cpu))
860 		return_VALUE(AE_ERROR);
861 
862 	if (arch_register_cpu(*p_cpu)) {
863 		acpi_unmap_lsapic(*p_cpu);
864 		return_VALUE(AE_ERROR);
865 	}
866 
867 	return_VALUE(AE_OK);
868 }
869 
870 static int acpi_processor_handle_eject(struct acpi_processor *pr)
871 {
872 	if (cpu_online(pr->id)) {
873 		return (-EINVAL);
874 	}
875 	arch_unregister_cpu(pr->id);
876 	acpi_unmap_lsapic(pr->id);
877 	return (0);
878 }
879 #else
880 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
881 {
882 	return AE_ERROR;
883 }
884 static int acpi_processor_handle_eject(struct acpi_processor *pr)
885 {
886 	return (-EINVAL);
887 }
888 #endif
889 
890 static
891 void acpi_processor_install_hotplug_notify(void)
892 {
893 #ifdef CONFIG_ACPI_HOTPLUG_CPU
894 	int action = INSTALL_NOTIFY_HANDLER;
895 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
896 			    ACPI_ROOT_OBJECT,
897 			    ACPI_UINT32_MAX,
898 			    processor_walk_namespace_cb, &action, NULL);
899 #endif
900 }
901 
902 static
903 void acpi_processor_uninstall_hotplug_notify(void)
904 {
905 #ifdef CONFIG_ACPI_HOTPLUG_CPU
906 	int action = UNINSTALL_NOTIFY_HANDLER;
907 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
908 			    ACPI_ROOT_OBJECT,
909 			    ACPI_UINT32_MAX,
910 			    processor_walk_namespace_cb, &action, NULL);
911 #endif
912 }
913 
914 /*
915  * We keep the driver loaded even when ACPI is not running.
916  * This is needed for the powernow-k8 driver, that works even without
917  * ACPI, but needs symbols from this driver
918  */
919 
920 static int __init acpi_processor_init(void)
921 {
922 	int result = 0;
923 
924 	ACPI_FUNCTION_TRACE("acpi_processor_init");
925 
926 	memset(&processors, 0, sizeof(processors));
927 	memset(&errata, 0, sizeof(errata));
928 
929 	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
930 	if (!acpi_processor_dir)
931 		return_VALUE(0);
932 	acpi_processor_dir->owner = THIS_MODULE;
933 
934 	result = acpi_bus_register_driver(&acpi_processor_driver);
935 	if (result < 0) {
936 		remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
937 		return_VALUE(0);
938 	}
939 
940 	acpi_processor_install_hotplug_notify();
941 
942 	acpi_thermal_cpufreq_init();
943 
944 	acpi_processor_ppc_init();
945 
946 	return_VALUE(0);
947 }
948 
949 static void __exit acpi_processor_exit(void)
950 {
951 	ACPI_FUNCTION_TRACE("acpi_processor_exit");
952 
953 	acpi_processor_ppc_exit();
954 
955 	acpi_thermal_cpufreq_exit();
956 
957 	acpi_processor_uninstall_hotplug_notify();
958 
959 	acpi_bus_unregister_driver(&acpi_processor_driver);
960 
961 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
962 
963 	return_VOID;
964 }
965 
966 module_init(acpi_processor_init);
967 module_exit(acpi_processor_exit);
968 
969 EXPORT_SYMBOL(acpi_processor_set_thermal_limit);
970 
971 MODULE_ALIAS("processor");
972