xref: /linux/drivers/acpi/processor_core.c (revision aeb3f46252e26acdc60a1a8e31fb1ca6319d9a07)
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_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 
71 #define ACPI_PROCESSOR_LIMIT_USER	0
72 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
73 
74 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
75 ACPI_MODULE_NAME("processor_core");
76 
77 MODULE_AUTHOR("Paul Diefenbaugh");
78 MODULE_DESCRIPTION("ACPI Processor Driver");
79 MODULE_LICENSE("GPL");
80 
81 static int acpi_processor_add(struct acpi_device *device);
82 static int acpi_processor_start(struct acpi_device *device);
83 static int acpi_processor_remove(struct acpi_device *device, int type);
84 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file);
85 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data);
86 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
87 static int acpi_processor_handle_eject(struct acpi_processor *pr);
88 extern int acpi_processor_tstate_has_changed(struct acpi_processor *pr);
89 
90 
91 static const struct acpi_device_id processor_device_ids[] = {
92 	{ACPI_PROCESSOR_HID, 0},
93 	{"", 0},
94 };
95 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
96 
97 static struct acpi_driver acpi_processor_driver = {
98 	.name = "processor",
99 	.class = ACPI_PROCESSOR_CLASS,
100 	.ids = processor_device_ids,
101 	.ops = {
102 		.add = acpi_processor_add,
103 		.remove = acpi_processor_remove,
104 		.start = acpi_processor_start,
105 		},
106 };
107 
108 #define INSTALL_NOTIFY_HANDLER		1
109 #define UNINSTALL_NOTIFY_HANDLER	2
110 
111 static const struct file_operations acpi_processor_info_fops = {
112 	.open = acpi_processor_info_open_fs,
113 	.read = seq_read,
114 	.llseek = seq_lseek,
115 	.release = single_release,
116 };
117 
118 struct acpi_processor *processors[NR_CPUS];
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 /* --------------------------------------------------------------------------
250                               Common ACPI processor functions
251    -------------------------------------------------------------------------- */
252 
253 /*
254  * _PDC is required for a BIOS-OS handshake for most of the newer
255  * ACPI processor features.
256  */
257 static int acpi_processor_set_pdc(struct acpi_processor *pr)
258 {
259 	struct acpi_object_list *pdc_in = pr->pdc;
260 	acpi_status status = AE_OK;
261 
262 
263 	if (!pdc_in)
264 		return status;
265 
266 	status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
267 
268 	if (ACPI_FAILURE(status))
269 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
270 		    "Could not evaluate _PDC, using legacy perf. control...\n"));
271 
272 	return status;
273 }
274 
275 /* --------------------------------------------------------------------------
276                               FS Interface (/proc)
277    -------------------------------------------------------------------------- */
278 
279 static struct proc_dir_entry *acpi_processor_dir = NULL;
280 
281 static int acpi_processor_info_seq_show(struct seq_file *seq, void *offset)
282 {
283 	struct acpi_processor *pr = seq->private;
284 
285 
286 	if (!pr)
287 		goto end;
288 
289 	seq_printf(seq, "processor id:            %d\n"
290 		   "acpi id:                 %d\n"
291 		   "bus mastering control:   %s\n"
292 		   "power management:        %s\n"
293 		   "throttling control:      %s\n"
294 		   "limit interface:         %s\n",
295 		   pr->id,
296 		   pr->acpi_id,
297 		   pr->flags.bm_control ? "yes" : "no",
298 		   pr->flags.power ? "yes" : "no",
299 		   pr->flags.throttling ? "yes" : "no",
300 		   pr->flags.limit ? "yes" : "no");
301 
302       end:
303 	return 0;
304 }
305 
306 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
307 {
308 	return single_open(file, acpi_processor_info_seq_show,
309 			   PDE(inode)->data);
310 }
311 
312 static int acpi_processor_add_fs(struct acpi_device *device)
313 {
314 	struct proc_dir_entry *entry = NULL;
315 
316 
317 	if (!acpi_device_dir(device)) {
318 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
319 						     acpi_processor_dir);
320 		if (!acpi_device_dir(device))
321 			return -ENODEV;
322 	}
323 	acpi_device_dir(device)->owner = THIS_MODULE;
324 
325 	/* 'info' [R] */
326 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_INFO,
327 				  S_IRUGO, acpi_device_dir(device));
328 	if (!entry)
329 		return -EIO;
330 	else {
331 		entry->proc_fops = &acpi_processor_info_fops;
332 		entry->data = acpi_driver_data(device);
333 		entry->owner = THIS_MODULE;
334 	}
335 
336 	/* 'throttling' [R/W] */
337 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
338 				  S_IFREG | S_IRUGO | S_IWUSR,
339 				  acpi_device_dir(device));
340 	if (!entry)
341 		return -EIO;
342 	else {
343 		entry->proc_fops = &acpi_processor_throttling_fops;
344 		entry->data = acpi_driver_data(device);
345 		entry->owner = THIS_MODULE;
346 	}
347 
348 	/* 'limit' [R/W] */
349 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
350 				  S_IFREG | S_IRUGO | S_IWUSR,
351 				  acpi_device_dir(device));
352 	if (!entry)
353 		return -EIO;
354 	else {
355 		entry->proc_fops = &acpi_processor_limit_fops;
356 		entry->data = acpi_driver_data(device);
357 		entry->owner = THIS_MODULE;
358 	}
359 
360 	return 0;
361 }
362 
363 static int acpi_processor_remove_fs(struct acpi_device *device)
364 {
365 
366 	if (acpi_device_dir(device)) {
367 		remove_proc_entry(ACPI_PROCESSOR_FILE_INFO,
368 				  acpi_device_dir(device));
369 		remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
370 				  acpi_device_dir(device));
371 		remove_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
372 				  acpi_device_dir(device));
373 		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
374 		acpi_device_dir(device) = NULL;
375 	}
376 
377 	return 0;
378 }
379 
380 /* Use the acpiid in MADT to map cpus in case of SMP */
381 
382 #ifndef CONFIG_SMP
383 static int get_cpu_id(acpi_handle handle, u32 acpi_id) {return -1;}
384 #else
385 
386 static struct acpi_table_madt *madt;
387 
388 static int map_lapic_id(struct acpi_subtable_header *entry,
389 		 u32 acpi_id, int *apic_id)
390 {
391 	struct acpi_madt_local_apic *lapic =
392 		(struct acpi_madt_local_apic *)entry;
393 	if ((lapic->lapic_flags & ACPI_MADT_ENABLED) &&
394 	    lapic->processor_id == acpi_id) {
395 		*apic_id = lapic->id;
396 		return 1;
397 	}
398 	return 0;
399 }
400 
401 static int map_lsapic_id(struct acpi_subtable_header *entry,
402 		  u32 acpi_id, int *apic_id)
403 {
404 	struct acpi_madt_local_sapic *lsapic =
405 		(struct acpi_madt_local_sapic *)entry;
406 	/* Only check enabled APICs*/
407 	if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
408 		/* First check against id */
409 		if (lsapic->processor_id == acpi_id) {
410 			*apic_id = (lsapic->id << 8) | lsapic->eid;
411 			return 1;
412 		/* Check against optional uid */
413 		} else if (entry->length >= 16 &&
414 			lsapic->uid == acpi_id) {
415 			*apic_id = lsapic->uid;
416 			return 1;
417 		}
418 	}
419 	return 0;
420 }
421 
422 #ifdef CONFIG_IA64
423 #define arch_cpu_to_apicid 	ia64_cpu_to_sapicid
424 #else
425 #define arch_cpu_to_apicid 	x86_cpu_to_apicid
426 #endif
427 
428 static int map_madt_entry(u32 acpi_id)
429 {
430 	unsigned long madt_end, entry;
431 	int apic_id = -1;
432 
433 	if (!madt)
434 		return apic_id;
435 
436 	entry = (unsigned long)madt;
437 	madt_end = entry + madt->header.length;
438 
439 	/* Parse all entries looking for a match. */
440 
441 	entry += sizeof(struct acpi_table_madt);
442 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
443 		struct acpi_subtable_header *header =
444 			(struct acpi_subtable_header *)entry;
445 		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
446 			if (map_lapic_id(header, acpi_id, &apic_id))
447 				break;
448 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
449 			if (map_lsapic_id(header, acpi_id, &apic_id))
450 				break;
451 		}
452 		entry += header->length;
453 	}
454 	return apic_id;
455 }
456 
457 static int map_mat_entry(acpi_handle handle, u32 acpi_id)
458 {
459 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
460 	union acpi_object *obj;
461 	struct acpi_subtable_header *header;
462 	int apic_id = -1;
463 
464 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
465 		goto exit;
466 
467 	if (!buffer.length || !buffer.pointer)
468 		goto exit;
469 
470 	obj = buffer.pointer;
471 	if (obj->type != ACPI_TYPE_BUFFER ||
472 	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
473 		goto exit;
474 	}
475 
476 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
477 	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
478 		map_lapic_id(header, acpi_id, &apic_id);
479 	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
480 		map_lsapic_id(header, acpi_id, &apic_id);
481 	}
482 
483 exit:
484 	if (buffer.pointer)
485 		kfree(buffer.pointer);
486 	return apic_id;
487 }
488 
489 static int get_cpu_id(acpi_handle handle, u32 acpi_id)
490 {
491 	int i;
492 	int apic_id = -1;
493 
494 	apic_id = map_mat_entry(handle, acpi_id);
495 	if (apic_id == -1)
496 		apic_id = map_madt_entry(acpi_id);
497 	if (apic_id == -1)
498 		return apic_id;
499 
500 	for (i = 0; i < NR_CPUS; ++i) {
501 		if (arch_cpu_to_apicid[i] == apic_id)
502 			return i;
503 	}
504 	return -1;
505 }
506 #endif
507 
508 /* --------------------------------------------------------------------------
509                                  Driver Interface
510    -------------------------------------------------------------------------- */
511 
512 static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
513 {
514 	acpi_status status = 0;
515 	union acpi_object object = { 0 };
516 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
517 	int cpu_index;
518 	static int cpu0_initialized;
519 
520 
521 	if (!pr)
522 		return -EINVAL;
523 
524 	if (num_online_cpus() > 1)
525 		errata.smp = TRUE;
526 
527 	acpi_processor_errata(pr);
528 
529 	/*
530 	 * Check to see if we have bus mastering arbitration control.  This
531 	 * is required for proper C3 usage (to maintain cache coherency).
532 	 */
533 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
534 		pr->flags.bm_control = 1;
535 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
536 				  "Bus mastering arbitration control present\n"));
537 	} else
538 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
539 				  "No bus mastering arbitration control\n"));
540 
541 	/* Check if it is a Device with HID and UID */
542 	if (has_uid) {
543 		unsigned long value;
544 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
545 						NULL, &value);
546 		if (ACPI_FAILURE(status)) {
547 			printk(KERN_ERR PREFIX "Evaluating processor _UID\n");
548 			return -ENODEV;
549 		}
550 		pr->acpi_id = value;
551 	} else {
552 		/*
553 		* Evalute the processor object.  Note that it is common on SMP to
554 		* have the first (boot) processor with a valid PBLK address while
555 		* all others have a NULL address.
556 		*/
557 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
558 		if (ACPI_FAILURE(status)) {
559 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
560 			return -ENODEV;
561 		}
562 
563 		/*
564 		* TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
565 		*      >>> 'acpi_get_processor_id(acpi_id, &id)' in arch/xxx/acpi.c
566 		*/
567 		pr->acpi_id = object.processor.proc_id;
568 	}
569 	cpu_index = get_cpu_id(pr->handle, pr->acpi_id);
570 
571 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
572 	if (!cpu0_initialized && (cpu_index == -1) &&
573 	    (num_online_cpus() == 1)) {
574 		cpu_index = 0;
575 	}
576 
577 	cpu0_initialized = 1;
578 
579 	pr->id = cpu_index;
580 
581 	/*
582 	 *  Extra Processor objects may be enumerated on MP systems with
583 	 *  less than the max # of CPUs. They should be ignored _iff
584 	 *  they are physically not present.
585 	 */
586 	if (pr->id == -1) {
587 		if (ACPI_FAILURE
588 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
589 			return -ENODEV;
590 		}
591 	}
592 
593 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
594 			  pr->acpi_id));
595 
596 	if (!object.processor.pblk_address)
597 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
598 	else if (object.processor.pblk_length != 6)
599 		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
600 			    object.processor.pblk_length);
601 	else {
602 		pr->throttling.address = object.processor.pblk_address;
603 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
604 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
605 
606 		pr->pblk = object.processor.pblk_address;
607 
608 		/*
609 		 * We don't care about error returns - we just try to mark
610 		 * these reserved so that nobody else is confused into thinking
611 		 * that this region might be unused..
612 		 *
613 		 * (In particular, allocating the IO range for Cardbus)
614 		 */
615 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
616 	}
617 
618 #ifdef CONFIG_CPU_FREQ
619 	acpi_processor_ppc_has_changed(pr);
620 #endif
621 	acpi_processor_get_throttling_info(pr);
622 	acpi_processor_get_limit_info(pr);
623 
624 	return 0;
625 }
626 
627 static void *processor_device_array[NR_CPUS];
628 
629 static int __cpuinit acpi_processor_start(struct acpi_device *device)
630 {
631 	int result = 0;
632 	acpi_status status = AE_OK;
633 	struct acpi_processor *pr;
634 
635 
636 	pr = acpi_driver_data(device);
637 
638 	result = acpi_processor_get_info(pr, device->flags.unique_id);
639 	if (result) {
640 		/* Processor is physically not present */
641 		return 0;
642 	}
643 
644 	BUG_ON((pr->id >= NR_CPUS) || (pr->id < 0));
645 
646 	/*
647 	 * Buggy BIOS check
648 	 * ACPI id of processors can be reported wrongly by the BIOS.
649 	 * Don't trust it blindly
650 	 */
651 	if (processor_device_array[pr->id] != NULL &&
652 	    processor_device_array[pr->id] != device) {
653 		printk(KERN_WARNING "BIOS reported wrong ACPI id"
654 			"for the processor\n");
655 		return -ENODEV;
656 	}
657 	processor_device_array[pr->id] = device;
658 
659 	processors[pr->id] = pr;
660 
661 	result = acpi_processor_add_fs(device);
662 	if (result)
663 		goto end;
664 
665 	status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
666 					     acpi_processor_notify, pr);
667 
668 	/* _PDC call should be done before doing anything else (if reqd.). */
669 	arch_acpi_processor_init_pdc(pr);
670 	acpi_processor_set_pdc(pr);
671 
672 	acpi_processor_power_init(pr, device);
673 
674 	if (pr->flags.throttling) {
675 		printk(KERN_INFO PREFIX "%s [%s] (supports",
676 		       acpi_device_name(device), acpi_device_bid(device));
677 		printk(" %d throttling states", pr->throttling.state_count);
678 		printk(")\n");
679 	}
680 
681       end:
682 
683 	return result;
684 }
685 
686 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
687 {
688 	struct acpi_processor *pr = data;
689 	struct acpi_device *device = NULL;
690 
691 
692 	if (!pr)
693 		return;
694 
695 	if (acpi_bus_get_device(pr->handle, &device))
696 		return;
697 
698 	switch (event) {
699 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
700 		acpi_processor_ppc_has_changed(pr);
701 		acpi_bus_generate_event(device, event,
702 					pr->performance_platform_limit);
703 		break;
704 	case ACPI_PROCESSOR_NOTIFY_POWER:
705 		acpi_processor_cst_has_changed(pr);
706 		acpi_bus_generate_event(device, event, 0);
707 		break;
708 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
709 		acpi_processor_tstate_has_changed(pr);
710 		acpi_bus_generate_event(device, event, 0);
711 	default:
712 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
713 				  "Unsupported event [0x%x]\n", event));
714 		break;
715 	}
716 
717 	return;
718 }
719 
720 static int acpi_processor_add(struct acpi_device *device)
721 {
722 	struct acpi_processor *pr = NULL;
723 
724 
725 	if (!device)
726 		return -EINVAL;
727 
728 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
729 	if (!pr)
730 		return -ENOMEM;
731 
732 	pr->handle = device->handle;
733 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
734 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
735 	acpi_driver_data(device) = pr;
736 
737 	return 0;
738 }
739 
740 static int acpi_processor_remove(struct acpi_device *device, int type)
741 {
742 	acpi_status status = AE_OK;
743 	struct acpi_processor *pr = NULL;
744 
745 
746 	if (!device || !acpi_driver_data(device))
747 		return -EINVAL;
748 
749 	pr = acpi_driver_data(device);
750 
751 	if (pr->id >= NR_CPUS) {
752 		kfree(pr);
753 		return 0;
754 	}
755 
756 	if (type == ACPI_BUS_REMOVAL_EJECT) {
757 		if (acpi_processor_handle_eject(pr))
758 			return -EINVAL;
759 	}
760 
761 	acpi_processor_power_exit(pr, device);
762 
763 	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
764 					    acpi_processor_notify);
765 
766 	acpi_processor_remove_fs(device);
767 
768 	processors[pr->id] = NULL;
769 
770 	kfree(pr);
771 
772 	return 0;
773 }
774 
775 #ifdef CONFIG_ACPI_HOTPLUG_CPU
776 /****************************************************************************
777  * 	Acpi processor hotplug support 				       	    *
778  ****************************************************************************/
779 
780 static int is_processor_present(acpi_handle handle);
781 
782 static int is_processor_present(acpi_handle handle)
783 {
784 	acpi_status status;
785 	unsigned long sta = 0;
786 
787 
788 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
789 	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) {
790 		ACPI_EXCEPTION((AE_INFO, status, "Processor Device is not present"));
791 		return 0;
792 	}
793 	return 1;
794 }
795 
796 static
797 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
798 {
799 	acpi_handle phandle;
800 	struct acpi_device *pdev;
801 	struct acpi_processor *pr;
802 
803 
804 	if (acpi_get_parent(handle, &phandle)) {
805 		return -ENODEV;
806 	}
807 
808 	if (acpi_bus_get_device(phandle, &pdev)) {
809 		return -ENODEV;
810 	}
811 
812 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
813 		return -ENODEV;
814 	}
815 
816 	acpi_bus_start(*device);
817 
818 	pr = acpi_driver_data(*device);
819 	if (!pr)
820 		return -ENODEV;
821 
822 	if ((pr->id >= 0) && (pr->id < NR_CPUS)) {
823 		kobject_uevent(&(*device)->dev.kobj, KOBJ_ONLINE);
824 	}
825 	return 0;
826 }
827 
828 static void
829 acpi_processor_hotplug_notify(acpi_handle handle, u32 event, void *data)
830 {
831 	struct acpi_processor *pr;
832 	struct acpi_device *device = NULL;
833 	int result;
834 
835 
836 	switch (event) {
837 	case ACPI_NOTIFY_BUS_CHECK:
838 	case ACPI_NOTIFY_DEVICE_CHECK:
839 		printk("Processor driver received %s event\n",
840 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
841 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
842 
843 		if (!is_processor_present(handle))
844 			break;
845 
846 		if (acpi_bus_get_device(handle, &device)) {
847 			result = acpi_processor_device_add(handle, &device);
848 			if (result)
849 				printk(KERN_ERR PREFIX
850 					    "Unable to add the device\n");
851 			break;
852 		}
853 
854 		pr = acpi_driver_data(device);
855 		if (!pr) {
856 			printk(KERN_ERR PREFIX "Driver data is NULL\n");
857 			break;
858 		}
859 
860 		if (pr->id >= 0 && (pr->id < NR_CPUS)) {
861 			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
862 			break;
863 		}
864 
865 		result = acpi_processor_start(device);
866 		if ((!result) && ((pr->id >= 0) && (pr->id < NR_CPUS))) {
867 			kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
868 		} else {
869 			printk(KERN_ERR PREFIX "Device [%s] failed to start\n",
870 				    acpi_device_bid(device));
871 		}
872 		break;
873 	case ACPI_NOTIFY_EJECT_REQUEST:
874 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
875 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
876 
877 		if (acpi_bus_get_device(handle, &device)) {
878 			printk(KERN_ERR PREFIX
879 				    "Device don't exist, dropping EJECT\n");
880 			break;
881 		}
882 		pr = acpi_driver_data(device);
883 		if (!pr) {
884 			printk(KERN_ERR PREFIX
885 				    "Driver data is NULL, dropping EJECT\n");
886 			return;
887 		}
888 
889 		if ((pr->id < NR_CPUS) && (cpu_present(pr->id)))
890 			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
891 		break;
892 	default:
893 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
894 				  "Unsupported event [0x%x]\n", event));
895 		break;
896 	}
897 
898 	return;
899 }
900 
901 static acpi_status
902 processor_walk_namespace_cb(acpi_handle handle,
903 			    u32 lvl, void *context, void **rv)
904 {
905 	acpi_status status;
906 	int *action = context;
907 	acpi_object_type type = 0;
908 
909 	status = acpi_get_type(handle, &type);
910 	if (ACPI_FAILURE(status))
911 		return (AE_OK);
912 
913 	if (type != ACPI_TYPE_PROCESSOR)
914 		return (AE_OK);
915 
916 	switch (*action) {
917 	case INSTALL_NOTIFY_HANDLER:
918 		acpi_install_notify_handler(handle,
919 					    ACPI_SYSTEM_NOTIFY,
920 					    acpi_processor_hotplug_notify,
921 					    NULL);
922 		break;
923 	case UNINSTALL_NOTIFY_HANDLER:
924 		acpi_remove_notify_handler(handle,
925 					   ACPI_SYSTEM_NOTIFY,
926 					   acpi_processor_hotplug_notify);
927 		break;
928 	default:
929 		break;
930 	}
931 
932 	return (AE_OK);
933 }
934 
935 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
936 {
937 
938 	if (!is_processor_present(handle)) {
939 		return AE_ERROR;
940 	}
941 
942 	if (acpi_map_lsapic(handle, p_cpu))
943 		return AE_ERROR;
944 
945 	if (arch_register_cpu(*p_cpu)) {
946 		acpi_unmap_lsapic(*p_cpu);
947 		return AE_ERROR;
948 	}
949 
950 	return AE_OK;
951 }
952 
953 static int acpi_processor_handle_eject(struct acpi_processor *pr)
954 {
955 	if (cpu_online(pr->id)) {
956 		return (-EINVAL);
957 	}
958 	arch_unregister_cpu(pr->id);
959 	acpi_unmap_lsapic(pr->id);
960 	return (0);
961 }
962 #else
963 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
964 {
965 	return AE_ERROR;
966 }
967 static int acpi_processor_handle_eject(struct acpi_processor *pr)
968 {
969 	return (-EINVAL);
970 }
971 #endif
972 
973 static
974 void acpi_processor_install_hotplug_notify(void)
975 {
976 #ifdef CONFIG_ACPI_HOTPLUG_CPU
977 	int action = INSTALL_NOTIFY_HANDLER;
978 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
979 			    ACPI_ROOT_OBJECT,
980 			    ACPI_UINT32_MAX,
981 			    processor_walk_namespace_cb, &action, NULL);
982 #endif
983 }
984 
985 static
986 void acpi_processor_uninstall_hotplug_notify(void)
987 {
988 #ifdef CONFIG_ACPI_HOTPLUG_CPU
989 	int action = UNINSTALL_NOTIFY_HANDLER;
990 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
991 			    ACPI_ROOT_OBJECT,
992 			    ACPI_UINT32_MAX,
993 			    processor_walk_namespace_cb, &action, NULL);
994 #endif
995 }
996 
997 /*
998  * We keep the driver loaded even when ACPI is not running.
999  * This is needed for the powernow-k8 driver, that works even without
1000  * ACPI, but needs symbols from this driver
1001  */
1002 
1003 static int __init acpi_processor_init(void)
1004 {
1005 	int result = 0;
1006 
1007 
1008 	memset(&processors, 0, sizeof(processors));
1009 	memset(&errata, 0, sizeof(errata));
1010 
1011 #ifdef CONFIG_SMP
1012 	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
1013 				(struct acpi_table_header **)&madt)))
1014 		madt = NULL;
1015 #endif
1016 
1017 	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1018 	if (!acpi_processor_dir)
1019 		return -ENOMEM;
1020 	acpi_processor_dir->owner = THIS_MODULE;
1021 
1022 	result = acpi_bus_register_driver(&acpi_processor_driver);
1023 	if (result < 0) {
1024 		remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1025 		return result;
1026 	}
1027 
1028 	acpi_processor_install_hotplug_notify();
1029 
1030 	acpi_thermal_cpufreq_init();
1031 
1032 	acpi_processor_ppc_init();
1033 
1034 	return 0;
1035 }
1036 
1037 static void __exit acpi_processor_exit(void)
1038 {
1039 
1040 	acpi_processor_ppc_exit();
1041 
1042 	acpi_thermal_cpufreq_exit();
1043 
1044 	acpi_processor_uninstall_hotplug_notify();
1045 
1046 	acpi_bus_unregister_driver(&acpi_processor_driver);
1047 
1048 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1049 
1050 	return;
1051 }
1052 
1053 module_init(acpi_processor_init);
1054 module_exit(acpi_processor_exit);
1055 
1056 EXPORT_SYMBOL(acpi_processor_set_thermal_limit);
1057 
1058 MODULE_ALIAS("processor");
1059