xref: /openbmc/linux/drivers/acpi/processor_core.c (revision 64c70b1c)
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 
70 #define ACPI_PROCESSOR_LIMIT_USER	0
71 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
72 
73 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
74 ACPI_MODULE_NAME("processor_core");
75 
76 MODULE_AUTHOR("Paul Diefenbaugh");
77 MODULE_DESCRIPTION("ACPI Processor Driver");
78 MODULE_LICENSE("GPL");
79 
80 static int acpi_processor_add(struct acpi_device *device);
81 static int acpi_processor_start(struct acpi_device *device);
82 static int acpi_processor_remove(struct acpi_device *device, int type);
83 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file);
84 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data);
85 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
86 static int acpi_processor_handle_eject(struct acpi_processor *pr);
87 
88 static struct acpi_driver acpi_processor_driver = {
89 	.name = "processor",
90 	.class = ACPI_PROCESSOR_CLASS,
91 	.ids = ACPI_PROCESSOR_HID,
92 	.ops = {
93 		.add = acpi_processor_add,
94 		.remove = acpi_processor_remove,
95 		.start = acpi_processor_start,
96 		},
97 };
98 
99 #define INSTALL_NOTIFY_HANDLER		1
100 #define UNINSTALL_NOTIFY_HANDLER	2
101 
102 static const struct file_operations acpi_processor_info_fops = {
103 	.open = acpi_processor_info_open_fs,
104 	.read = seq_read,
105 	.llseek = seq_lseek,
106 	.release = single_release,
107 };
108 
109 struct acpi_processor *processors[NR_CPUS];
110 struct acpi_processor_errata errata __read_mostly;
111 
112 /* --------------------------------------------------------------------------
113                                 Errata Handling
114    -------------------------------------------------------------------------- */
115 
116 static int acpi_processor_errata_piix4(struct pci_dev *dev)
117 {
118 	u8 rev = 0;
119 	u8 value1 = 0;
120 	u8 value2 = 0;
121 
122 
123 	if (!dev)
124 		return -EINVAL;
125 
126 	/*
127 	 * Note that 'dev' references the PIIX4 ACPI Controller.
128 	 */
129 
130 	pci_read_config_byte(dev, PCI_REVISION_ID, &rev);
131 
132 	switch (rev) {
133 	case 0:
134 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
135 		break;
136 	case 1:
137 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
138 		break;
139 	case 2:
140 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
141 		break;
142 	case 3:
143 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
144 		break;
145 	default:
146 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
147 		break;
148 	}
149 
150 	switch (rev) {
151 
152 	case 0:		/* PIIX4 A-step */
153 	case 1:		/* PIIX4 B-step */
154 		/*
155 		 * See specification changes #13 ("Manual Throttle Duty Cycle")
156 		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
157 		 * erratum #5 ("STPCLK# Deassertion Time") from the January
158 		 * 2002 PIIX4 specification update.  Applies to only older
159 		 * PIIX4 models.
160 		 */
161 		errata.piix4.throttle = 1;
162 
163 	case 2:		/* PIIX4E */
164 	case 3:		/* PIIX4M */
165 		/*
166 		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
167 		 * Livelock") from the January 2002 PIIX4 specification update.
168 		 * Applies to all PIIX4 models.
169 		 */
170 
171 		/*
172 		 * BM-IDE
173 		 * ------
174 		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
175 		 * Status register address.  We'll use this later to read
176 		 * each IDE controller's DMA status to make sure we catch all
177 		 * DMA activity.
178 		 */
179 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
180 				     PCI_DEVICE_ID_INTEL_82371AB,
181 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
182 		if (dev) {
183 			errata.piix4.bmisx = pci_resource_start(dev, 4);
184 			pci_dev_put(dev);
185 		}
186 
187 		/*
188 		 * Type-F DMA
189 		 * ----------
190 		 * Find the PIIX4 ISA Controller and read the Motherboard
191 		 * DMA controller's status to see if Type-F (Fast) DMA mode
192 		 * is enabled (bit 7) on either channel.  Note that we'll
193 		 * disable C3 support if this is enabled, as some legacy
194 		 * devices won't operate well if fast DMA is disabled.
195 		 */
196 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
197 				     PCI_DEVICE_ID_INTEL_82371AB_0,
198 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
199 		if (dev) {
200 			pci_read_config_byte(dev, 0x76, &value1);
201 			pci_read_config_byte(dev, 0x77, &value2);
202 			if ((value1 & 0x80) || (value2 & 0x80))
203 				errata.piix4.fdma = 1;
204 			pci_dev_put(dev);
205 		}
206 
207 		break;
208 	}
209 
210 	if (errata.piix4.bmisx)
211 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
212 				  "Bus master activity detection (BM-IDE) erratum enabled\n"));
213 	if (errata.piix4.fdma)
214 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
215 				  "Type-F DMA livelock erratum (C3 disabled)\n"));
216 
217 	return 0;
218 }
219 
220 static int acpi_processor_errata(struct acpi_processor *pr)
221 {
222 	int result = 0;
223 	struct pci_dev *dev = NULL;
224 
225 
226 	if (!pr)
227 		return -EINVAL;
228 
229 	/*
230 	 * PIIX4
231 	 */
232 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
233 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
234 			     PCI_ANY_ID, NULL);
235 	if (dev) {
236 		result = acpi_processor_errata_piix4(dev);
237 		pci_dev_put(dev);
238 	}
239 
240 	return result;
241 }
242 
243 /* --------------------------------------------------------------------------
244                               Common ACPI processor functions
245    -------------------------------------------------------------------------- */
246 
247 /*
248  * _PDC is required for a BIOS-OS handshake for most of the newer
249  * ACPI processor features.
250  */
251 static int acpi_processor_set_pdc(struct acpi_processor *pr)
252 {
253 	struct acpi_object_list *pdc_in = pr->pdc;
254 	acpi_status status = AE_OK;
255 
256 
257 	if (!pdc_in)
258 		return status;
259 
260 	status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
261 
262 	if (ACPI_FAILURE(status))
263 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
264 		    "Could not evaluate _PDC, using legacy perf. control...\n"));
265 
266 	return status;
267 }
268 
269 /* --------------------------------------------------------------------------
270                               FS Interface (/proc)
271    -------------------------------------------------------------------------- */
272 
273 static struct proc_dir_entry *acpi_processor_dir = NULL;
274 
275 static int acpi_processor_info_seq_show(struct seq_file *seq, void *offset)
276 {
277 	struct acpi_processor *pr = seq->private;
278 
279 
280 	if (!pr)
281 		goto end;
282 
283 	seq_printf(seq, "processor id:            %d\n"
284 		   "acpi id:                 %d\n"
285 		   "bus mastering control:   %s\n"
286 		   "power management:        %s\n"
287 		   "throttling control:      %s\n"
288 		   "limit interface:         %s\n",
289 		   pr->id,
290 		   pr->acpi_id,
291 		   pr->flags.bm_control ? "yes" : "no",
292 		   pr->flags.power ? "yes" : "no",
293 		   pr->flags.throttling ? "yes" : "no",
294 		   pr->flags.limit ? "yes" : "no");
295 
296       end:
297 	return 0;
298 }
299 
300 static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
301 {
302 	return single_open(file, acpi_processor_info_seq_show,
303 			   PDE(inode)->data);
304 }
305 
306 static int acpi_processor_add_fs(struct acpi_device *device)
307 {
308 	struct proc_dir_entry *entry = NULL;
309 
310 
311 	if (!acpi_device_dir(device)) {
312 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
313 						     acpi_processor_dir);
314 		if (!acpi_device_dir(device))
315 			return -ENODEV;
316 	}
317 	acpi_device_dir(device)->owner = THIS_MODULE;
318 
319 	/* 'info' [R] */
320 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_INFO,
321 				  S_IRUGO, acpi_device_dir(device));
322 	if (!entry)
323 		return -EIO;
324 	else {
325 		entry->proc_fops = &acpi_processor_info_fops;
326 		entry->data = acpi_driver_data(device);
327 		entry->owner = THIS_MODULE;
328 	}
329 
330 	/* 'throttling' [R/W] */
331 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
332 				  S_IFREG | S_IRUGO | S_IWUSR,
333 				  acpi_device_dir(device));
334 	if (!entry)
335 		return -EIO;
336 	else {
337 		entry->proc_fops = &acpi_processor_throttling_fops;
338 		entry->data = acpi_driver_data(device);
339 		entry->owner = THIS_MODULE;
340 	}
341 
342 	/* 'limit' [R/W] */
343 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
344 				  S_IFREG | S_IRUGO | S_IWUSR,
345 				  acpi_device_dir(device));
346 	if (!entry)
347 		return -EIO;
348 	else {
349 		entry->proc_fops = &acpi_processor_limit_fops;
350 		entry->data = acpi_driver_data(device);
351 		entry->owner = THIS_MODULE;
352 	}
353 
354 	return 0;
355 }
356 
357 static int acpi_processor_remove_fs(struct acpi_device *device)
358 {
359 
360 	if (acpi_device_dir(device)) {
361 		remove_proc_entry(ACPI_PROCESSOR_FILE_INFO,
362 				  acpi_device_dir(device));
363 		remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
364 				  acpi_device_dir(device));
365 		remove_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
366 				  acpi_device_dir(device));
367 		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
368 		acpi_device_dir(device) = NULL;
369 	}
370 
371 	return 0;
372 }
373 
374 /* Use the acpiid in MADT to map cpus in case of SMP */
375 
376 #ifndef CONFIG_SMP
377 static int get_cpu_id(acpi_handle handle, u32 acpi_id) {return -1;}
378 #else
379 
380 static struct acpi_table_madt *madt;
381 
382 static int map_lapic_id(struct acpi_subtable_header *entry,
383 		 u32 acpi_id, int *apic_id)
384 {
385 	struct acpi_madt_local_apic *lapic =
386 		(struct acpi_madt_local_apic *)entry;
387 	if ((lapic->lapic_flags & ACPI_MADT_ENABLED) &&
388 	    lapic->processor_id == acpi_id) {
389 		*apic_id = lapic->id;
390 		return 1;
391 	}
392 	return 0;
393 }
394 
395 static int map_lsapic_id(struct acpi_subtable_header *entry,
396 		  u32 acpi_id, int *apic_id)
397 {
398 	struct acpi_madt_local_sapic *lsapic =
399 		(struct acpi_madt_local_sapic *)entry;
400 	/* Only check enabled APICs*/
401 	if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
402 		/* First check against id */
403 		if (lsapic->processor_id == acpi_id) {
404 			*apic_id = (lsapic->id << 8) | lsapic->eid;
405 			return 1;
406 		/* Check against optional uid */
407 		} else if (entry->length >= 16 &&
408 			lsapic->uid == acpi_id) {
409 			*apic_id = lsapic->uid;
410 			return 1;
411 		}
412 	}
413 	return 0;
414 }
415 
416 #ifdef CONFIG_IA64
417 #define arch_cpu_to_apicid 	ia64_cpu_to_sapicid
418 #else
419 #define arch_cpu_to_apicid 	x86_cpu_to_apicid
420 #endif
421 
422 static int map_madt_entry(u32 acpi_id)
423 {
424 	unsigned long madt_end, entry;
425 	int apic_id = -1;
426 
427 	if (!madt)
428 		return apic_id;
429 
430 	entry = (unsigned long)madt;
431 	madt_end = entry + madt->header.length;
432 
433 	/* Parse all entries looking for a match. */
434 
435 	entry += sizeof(struct acpi_table_madt);
436 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
437 		struct acpi_subtable_header *header =
438 			(struct acpi_subtable_header *)entry;
439 		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
440 			if (map_lapic_id(header, acpi_id, &apic_id))
441 				break;
442 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
443 			if (map_lsapic_id(header, acpi_id, &apic_id))
444 				break;
445 		}
446 		entry += header->length;
447 	}
448 	return apic_id;
449 }
450 
451 static int map_mat_entry(acpi_handle handle, u32 acpi_id)
452 {
453 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
454 	union acpi_object *obj;
455 	struct acpi_subtable_header *header;
456 	int apic_id = -1;
457 
458 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
459 		goto exit;
460 
461 	if (!buffer.length || !buffer.pointer)
462 		goto exit;
463 
464 	obj = buffer.pointer;
465 	if (obj->type != ACPI_TYPE_BUFFER ||
466 	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
467 		goto exit;
468 	}
469 
470 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
471 	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
472 		map_lapic_id(header, acpi_id, &apic_id);
473 	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
474 		map_lsapic_id(header, acpi_id, &apic_id);
475 	}
476 
477 exit:
478 	if (buffer.pointer)
479 		kfree(buffer.pointer);
480 	return apic_id;
481 }
482 
483 static int get_cpu_id(acpi_handle handle, u32 acpi_id)
484 {
485 	int i;
486 	int apic_id = -1;
487 
488 	apic_id = map_mat_entry(handle, acpi_id);
489 	if (apic_id == -1)
490 		apic_id = map_madt_entry(acpi_id);
491 	if (apic_id == -1)
492 		return apic_id;
493 
494 	for (i = 0; i < NR_CPUS; ++i) {
495 		if (arch_cpu_to_apicid[i] == apic_id)
496 			return i;
497 	}
498 	return -1;
499 }
500 #endif
501 
502 /* --------------------------------------------------------------------------
503                                  Driver Interface
504    -------------------------------------------------------------------------- */
505 
506 static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
507 {
508 	acpi_status status = 0;
509 	union acpi_object object = { 0 };
510 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
511 	int cpu_index;
512 	static int cpu0_initialized;
513 
514 
515 	if (!pr)
516 		return -EINVAL;
517 
518 	if (num_online_cpus() > 1)
519 		errata.smp = TRUE;
520 
521 	acpi_processor_errata(pr);
522 
523 	/*
524 	 * Check to see if we have bus mastering arbitration control.  This
525 	 * is required for proper C3 usage (to maintain cache coherency).
526 	 */
527 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
528 		pr->flags.bm_control = 1;
529 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
530 				  "Bus mastering arbitration control present\n"));
531 	} else
532 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
533 				  "No bus mastering arbitration control\n"));
534 
535 	/* Check if it is a Device with HID and UID */
536 	if (has_uid) {
537 		unsigned long value;
538 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
539 						NULL, &value);
540 		if (ACPI_FAILURE(status)) {
541 			printk(KERN_ERR PREFIX "Evaluating processor _UID\n");
542 			return -ENODEV;
543 		}
544 		pr->acpi_id = value;
545 	} else {
546 		/*
547 		* Evalute the processor object.  Note that it is common on SMP to
548 		* have the first (boot) processor with a valid PBLK address while
549 		* all others have a NULL address.
550 		*/
551 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
552 		if (ACPI_FAILURE(status)) {
553 			printk(KERN_ERR PREFIX "Evaluating processor object\n");
554 			return -ENODEV;
555 		}
556 
557 		/*
558 		* TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
559 		*      >>> 'acpi_get_processor_id(acpi_id, &id)' in arch/xxx/acpi.c
560 		*/
561 		pr->acpi_id = object.processor.proc_id;
562 	}
563 	cpu_index = get_cpu_id(pr->handle, pr->acpi_id);
564 
565 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
566 	if (!cpu0_initialized && (cpu_index == -1) &&
567 	    (num_online_cpus() == 1)) {
568 		cpu_index = 0;
569 	}
570 
571 	cpu0_initialized = 1;
572 
573 	pr->id = cpu_index;
574 
575 	/*
576 	 *  Extra Processor objects may be enumerated on MP systems with
577 	 *  less than the max # of CPUs. They should be ignored _iff
578 	 *  they are physically not present.
579 	 */
580 	if (pr->id == -1) {
581 		if (ACPI_FAILURE
582 		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
583 			return -ENODEV;
584 		}
585 	}
586 
587 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
588 			  pr->acpi_id));
589 
590 	if (!object.processor.pblk_address)
591 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
592 	else if (object.processor.pblk_length != 6)
593 		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
594 			    object.processor.pblk_length);
595 	else {
596 		pr->throttling.address = object.processor.pblk_address;
597 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
598 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
599 
600 		pr->pblk = object.processor.pblk_address;
601 
602 		/*
603 		 * We don't care about error returns - we just try to mark
604 		 * these reserved so that nobody else is confused into thinking
605 		 * that this region might be unused..
606 		 *
607 		 * (In particular, allocating the IO range for Cardbus)
608 		 */
609 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
610 	}
611 
612 #ifdef CONFIG_CPU_FREQ
613 	acpi_processor_ppc_has_changed(pr);
614 #endif
615 	acpi_processor_get_throttling_info(pr);
616 	acpi_processor_get_limit_info(pr);
617 
618 	return 0;
619 }
620 
621 static void *processor_device_array[NR_CPUS];
622 
623 static int __cpuinit acpi_processor_start(struct acpi_device *device)
624 {
625 	int result = 0;
626 	acpi_status status = AE_OK;
627 	struct acpi_processor *pr;
628 
629 
630 	pr = acpi_driver_data(device);
631 
632 	result = acpi_processor_get_info(pr, device->flags.unique_id);
633 	if (result) {
634 		/* Processor is physically not present */
635 		return 0;
636 	}
637 
638 	BUG_ON((pr->id >= NR_CPUS) || (pr->id < 0));
639 
640 	/*
641 	 * Buggy BIOS check
642 	 * ACPI id of processors can be reported wrongly by the BIOS.
643 	 * Don't trust it blindly
644 	 */
645 	if (processor_device_array[pr->id] != NULL &&
646 	    processor_device_array[pr->id] != device) {
647 		printk(KERN_WARNING "BIOS reported wrong ACPI id"
648 			"for the processor\n");
649 		return -ENODEV;
650 	}
651 	processor_device_array[pr->id] = device;
652 
653 	processors[pr->id] = pr;
654 
655 	result = acpi_processor_add_fs(device);
656 	if (result)
657 		goto end;
658 
659 	status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
660 					     acpi_processor_notify, pr);
661 
662 	/* _PDC call should be done before doing anything else (if reqd.). */
663 	arch_acpi_processor_init_pdc(pr);
664 	acpi_processor_set_pdc(pr);
665 
666 	acpi_processor_power_init(pr, device);
667 
668 	if (pr->flags.throttling) {
669 		printk(KERN_INFO PREFIX "%s [%s] (supports",
670 		       acpi_device_name(device), acpi_device_bid(device));
671 		printk(" %d throttling states", pr->throttling.state_count);
672 		printk(")\n");
673 	}
674 
675       end:
676 
677 	return result;
678 }
679 
680 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
681 {
682 	struct acpi_processor *pr = data;
683 	struct acpi_device *device = NULL;
684 
685 
686 	if (!pr)
687 		return;
688 
689 	if (acpi_bus_get_device(pr->handle, &device))
690 		return;
691 
692 	switch (event) {
693 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
694 		acpi_processor_ppc_has_changed(pr);
695 		acpi_bus_generate_event(device, event,
696 					pr->performance_platform_limit);
697 		break;
698 	case ACPI_PROCESSOR_NOTIFY_POWER:
699 		acpi_processor_cst_has_changed(pr);
700 		acpi_bus_generate_event(device, event, 0);
701 		break;
702 	default:
703 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
704 				  "Unsupported event [0x%x]\n", event));
705 		break;
706 	}
707 
708 	return;
709 }
710 
711 static int acpi_processor_add(struct acpi_device *device)
712 {
713 	struct acpi_processor *pr = NULL;
714 
715 
716 	if (!device)
717 		return -EINVAL;
718 
719 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
720 	if (!pr)
721 		return -ENOMEM;
722 
723 	pr->handle = device->handle;
724 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
725 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
726 	acpi_driver_data(device) = pr;
727 
728 	return 0;
729 }
730 
731 static int acpi_processor_remove(struct acpi_device *device, int type)
732 {
733 	acpi_status status = AE_OK;
734 	struct acpi_processor *pr = NULL;
735 
736 
737 	if (!device || !acpi_driver_data(device))
738 		return -EINVAL;
739 
740 	pr = acpi_driver_data(device);
741 
742 	if (pr->id >= NR_CPUS) {
743 		kfree(pr);
744 		return 0;
745 	}
746 
747 	if (type == ACPI_BUS_REMOVAL_EJECT) {
748 		if (acpi_processor_handle_eject(pr))
749 			return -EINVAL;
750 	}
751 
752 	acpi_processor_power_exit(pr, device);
753 
754 	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
755 					    acpi_processor_notify);
756 
757 	acpi_processor_remove_fs(device);
758 
759 	processors[pr->id] = NULL;
760 
761 	kfree(pr);
762 
763 	return 0;
764 }
765 
766 #ifdef CONFIG_ACPI_HOTPLUG_CPU
767 /****************************************************************************
768  * 	Acpi processor hotplug support 				       	    *
769  ****************************************************************************/
770 
771 static int is_processor_present(acpi_handle handle);
772 
773 static int is_processor_present(acpi_handle handle)
774 {
775 	acpi_status status;
776 	unsigned long sta = 0;
777 
778 
779 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
780 	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) {
781 		ACPI_EXCEPTION((AE_INFO, status, "Processor Device is not present"));
782 		return 0;
783 	}
784 	return 1;
785 }
786 
787 static
788 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
789 {
790 	acpi_handle phandle;
791 	struct acpi_device *pdev;
792 	struct acpi_processor *pr;
793 
794 
795 	if (acpi_get_parent(handle, &phandle)) {
796 		return -ENODEV;
797 	}
798 
799 	if (acpi_bus_get_device(phandle, &pdev)) {
800 		return -ENODEV;
801 	}
802 
803 	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
804 		return -ENODEV;
805 	}
806 
807 	acpi_bus_start(*device);
808 
809 	pr = acpi_driver_data(*device);
810 	if (!pr)
811 		return -ENODEV;
812 
813 	if ((pr->id >= 0) && (pr->id < NR_CPUS)) {
814 		kobject_uevent(&(*device)->dev.kobj, KOBJ_ONLINE);
815 	}
816 	return 0;
817 }
818 
819 static void
820 acpi_processor_hotplug_notify(acpi_handle handle, u32 event, void *data)
821 {
822 	struct acpi_processor *pr;
823 	struct acpi_device *device = NULL;
824 	int result;
825 
826 
827 	switch (event) {
828 	case ACPI_NOTIFY_BUS_CHECK:
829 	case ACPI_NOTIFY_DEVICE_CHECK:
830 		printk("Processor driver received %s event\n",
831 		       (event == ACPI_NOTIFY_BUS_CHECK) ?
832 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
833 
834 		if (!is_processor_present(handle))
835 			break;
836 
837 		if (acpi_bus_get_device(handle, &device)) {
838 			result = acpi_processor_device_add(handle, &device);
839 			if (result)
840 				printk(KERN_ERR PREFIX
841 					    "Unable to add the device\n");
842 			break;
843 		}
844 
845 		pr = acpi_driver_data(device);
846 		if (!pr) {
847 			printk(KERN_ERR PREFIX "Driver data is NULL\n");
848 			break;
849 		}
850 
851 		if (pr->id >= 0 && (pr->id < NR_CPUS)) {
852 			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
853 			break;
854 		}
855 
856 		result = acpi_processor_start(device);
857 		if ((!result) && ((pr->id >= 0) && (pr->id < NR_CPUS))) {
858 			kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
859 		} else {
860 			printk(KERN_ERR PREFIX "Device [%s] failed to start\n",
861 				    acpi_device_bid(device));
862 		}
863 		break;
864 	case ACPI_NOTIFY_EJECT_REQUEST:
865 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
866 				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
867 
868 		if (acpi_bus_get_device(handle, &device)) {
869 			printk(KERN_ERR PREFIX
870 				    "Device don't exist, dropping EJECT\n");
871 			break;
872 		}
873 		pr = acpi_driver_data(device);
874 		if (!pr) {
875 			printk(KERN_ERR PREFIX
876 				    "Driver data is NULL, dropping EJECT\n");
877 			return;
878 		}
879 
880 		if ((pr->id < NR_CPUS) && (cpu_present(pr->id)))
881 			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
882 		break;
883 	default:
884 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
885 				  "Unsupported event [0x%x]\n", event));
886 		break;
887 	}
888 
889 	return;
890 }
891 
892 static acpi_status
893 processor_walk_namespace_cb(acpi_handle handle,
894 			    u32 lvl, void *context, void **rv)
895 {
896 	acpi_status status;
897 	int *action = context;
898 	acpi_object_type type = 0;
899 
900 	status = acpi_get_type(handle, &type);
901 	if (ACPI_FAILURE(status))
902 		return (AE_OK);
903 
904 	if (type != ACPI_TYPE_PROCESSOR)
905 		return (AE_OK);
906 
907 	switch (*action) {
908 	case INSTALL_NOTIFY_HANDLER:
909 		acpi_install_notify_handler(handle,
910 					    ACPI_SYSTEM_NOTIFY,
911 					    acpi_processor_hotplug_notify,
912 					    NULL);
913 		break;
914 	case UNINSTALL_NOTIFY_HANDLER:
915 		acpi_remove_notify_handler(handle,
916 					   ACPI_SYSTEM_NOTIFY,
917 					   acpi_processor_hotplug_notify);
918 		break;
919 	default:
920 		break;
921 	}
922 
923 	return (AE_OK);
924 }
925 
926 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
927 {
928 
929 	if (!is_processor_present(handle)) {
930 		return AE_ERROR;
931 	}
932 
933 	if (acpi_map_lsapic(handle, p_cpu))
934 		return AE_ERROR;
935 
936 	if (arch_register_cpu(*p_cpu)) {
937 		acpi_unmap_lsapic(*p_cpu);
938 		return AE_ERROR;
939 	}
940 
941 	return AE_OK;
942 }
943 
944 static int acpi_processor_handle_eject(struct acpi_processor *pr)
945 {
946 	if (cpu_online(pr->id)) {
947 		return (-EINVAL);
948 	}
949 	arch_unregister_cpu(pr->id);
950 	acpi_unmap_lsapic(pr->id);
951 	return (0);
952 }
953 #else
954 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
955 {
956 	return AE_ERROR;
957 }
958 static int acpi_processor_handle_eject(struct acpi_processor *pr)
959 {
960 	return (-EINVAL);
961 }
962 #endif
963 
964 static
965 void acpi_processor_install_hotplug_notify(void)
966 {
967 #ifdef CONFIG_ACPI_HOTPLUG_CPU
968 	int action = INSTALL_NOTIFY_HANDLER;
969 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
970 			    ACPI_ROOT_OBJECT,
971 			    ACPI_UINT32_MAX,
972 			    processor_walk_namespace_cb, &action, NULL);
973 #endif
974 }
975 
976 static
977 void acpi_processor_uninstall_hotplug_notify(void)
978 {
979 #ifdef CONFIG_ACPI_HOTPLUG_CPU
980 	int action = UNINSTALL_NOTIFY_HANDLER;
981 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
982 			    ACPI_ROOT_OBJECT,
983 			    ACPI_UINT32_MAX,
984 			    processor_walk_namespace_cb, &action, NULL);
985 #endif
986 }
987 
988 /*
989  * We keep the driver loaded even when ACPI is not running.
990  * This is needed for the powernow-k8 driver, that works even without
991  * ACPI, but needs symbols from this driver
992  */
993 
994 static int __init acpi_processor_init(void)
995 {
996 	int result = 0;
997 
998 
999 	memset(&processors, 0, sizeof(processors));
1000 	memset(&errata, 0, sizeof(errata));
1001 
1002 #ifdef CONFIG_SMP
1003 	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
1004 				(struct acpi_table_header **)&madt)))
1005 		madt = NULL;
1006 #endif
1007 
1008 	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1009 	if (!acpi_processor_dir)
1010 		return -ENOMEM;
1011 	acpi_processor_dir->owner = THIS_MODULE;
1012 
1013 	result = acpi_bus_register_driver(&acpi_processor_driver);
1014 	if (result < 0) {
1015 		remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1016 		return result;
1017 	}
1018 
1019 	acpi_processor_install_hotplug_notify();
1020 
1021 	acpi_thermal_cpufreq_init();
1022 
1023 	acpi_processor_ppc_init();
1024 
1025 	return 0;
1026 }
1027 
1028 static void __exit acpi_processor_exit(void)
1029 {
1030 
1031 	acpi_processor_ppc_exit();
1032 
1033 	acpi_thermal_cpufreq_exit();
1034 
1035 	acpi_processor_uninstall_hotplug_notify();
1036 
1037 	acpi_bus_unregister_driver(&acpi_processor_driver);
1038 
1039 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
1040 
1041 	return;
1042 }
1043 
1044 module_init(acpi_processor_init);
1045 module_exit(acpi_processor_exit);
1046 
1047 EXPORT_SYMBOL(acpi_processor_set_thermal_limit);
1048 
1049 MODULE_ALIAS("processor");
1050