xref: /openbmc/linux/drivers/acpi/bus.c (revision afb46f79)
1 /*
2  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
3  *
4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or (at
11  *  your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24 
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/kernel.h>
29 #include <linux/list.h>
30 #include <linux/sched.h>
31 #include <linux/pm.h>
32 #include <linux/device.h>
33 #include <linux/proc_fs.h>
34 #include <linux/acpi.h>
35 #include <linux/slab.h>
36 #include <linux/regulator/machine.h>
37 #ifdef CONFIG_X86
38 #include <asm/mpspec.h>
39 #endif
40 #include <linux/pci.h>
41 #include <acpi/apei.h>
42 #include <linux/dmi.h>
43 #include <linux/suspend.h>
44 
45 #include "internal.h"
46 
47 #define _COMPONENT		ACPI_BUS_COMPONENT
48 ACPI_MODULE_NAME("bus");
49 
50 struct acpi_device *acpi_root;
51 struct proc_dir_entry *acpi_root_dir;
52 EXPORT_SYMBOL(acpi_root_dir);
53 
54 #ifdef CONFIG_X86
55 static int set_copy_dsdt(const struct dmi_system_id *id)
56 {
57 	printk(KERN_NOTICE "%s detected - "
58 		"force copy of DSDT to local memory\n", id->ident);
59 	acpi_gbl_copy_dsdt_locally = 1;
60 	return 0;
61 }
62 
63 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
64 	/*
65 	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
66 	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
67 	 */
68 	{
69 	 .callback = set_copy_dsdt,
70 	 .ident = "TOSHIBA Satellite",
71 	 .matches = {
72 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
73 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
74 		},
75 	},
76 	{}
77 };
78 #else
79 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
80 	{}
81 };
82 #endif
83 
84 /* --------------------------------------------------------------------------
85                                 Device Management
86    -------------------------------------------------------------------------- */
87 
88 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
89 				       unsigned long long *sta)
90 {
91 	acpi_status status;
92 
93 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
94 	if (ACPI_SUCCESS(status))
95 		return AE_OK;
96 
97 	if (status == AE_NOT_FOUND) {
98 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
99 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
100 		return AE_OK;
101 	}
102 	return status;
103 }
104 
105 int acpi_bus_get_status(struct acpi_device *device)
106 {
107 	acpi_status status;
108 	unsigned long long sta;
109 
110 	status = acpi_bus_get_status_handle(device->handle, &sta);
111 	if (ACPI_FAILURE(status))
112 		return -ENODEV;
113 
114 	acpi_set_device_status(device, sta);
115 
116 	if (device->status.functional && !device->status.present) {
117 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
118 		       "functional but not present;\n",
119 			device->pnp.bus_id, (u32)sta));
120 	}
121 
122 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
123 			  device->pnp.bus_id, (u32)sta));
124 	return 0;
125 }
126 EXPORT_SYMBOL(acpi_bus_get_status);
127 
128 void acpi_bus_private_data_handler(acpi_handle handle,
129 				   void *context)
130 {
131 	return;
132 }
133 EXPORT_SYMBOL(acpi_bus_private_data_handler);
134 
135 int acpi_bus_get_private_data(acpi_handle handle, void **data)
136 {
137 	acpi_status status;
138 
139 	if (!*data)
140 		return -EINVAL;
141 
142 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
143 	if (ACPI_FAILURE(status) || !*data) {
144 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
145 				handle));
146 		return -ENODEV;
147 	}
148 
149 	return 0;
150 }
151 EXPORT_SYMBOL(acpi_bus_get_private_data);
152 
153 void acpi_bus_no_hotplug(acpi_handle handle)
154 {
155 	struct acpi_device *adev = NULL;
156 
157 	acpi_bus_get_device(handle, &adev);
158 	if (adev)
159 		adev->flags.no_hotplug = true;
160 }
161 EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
162 
163 static void acpi_print_osc_error(acpi_handle handle,
164 	struct acpi_osc_context *context, char *error)
165 {
166 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
167 	int i;
168 
169 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
170 		printk(KERN_DEBUG "%s\n", error);
171 	else {
172 		printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
173 		kfree(buffer.pointer);
174 	}
175 	printk(KERN_DEBUG"_OSC request data:");
176 	for (i = 0; i < context->cap.length; i += sizeof(u32))
177 		printk("%x ", *((u32 *)(context->cap.pointer + i)));
178 	printk("\n");
179 }
180 
181 acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
182 {
183 	int i;
184 	static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
185 		24, 26, 28, 30, 32, 34};
186 
187 	if (strlen(str) != 36)
188 		return AE_BAD_PARAMETER;
189 	for (i = 0; i < 36; i++) {
190 		if (i == 8 || i == 13 || i == 18 || i == 23) {
191 			if (str[i] != '-')
192 				return AE_BAD_PARAMETER;
193 		} else if (!isxdigit(str[i]))
194 			return AE_BAD_PARAMETER;
195 	}
196 	for (i = 0; i < 16; i++) {
197 		uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
198 		uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
199 	}
200 	return AE_OK;
201 }
202 EXPORT_SYMBOL_GPL(acpi_str_to_uuid);
203 
204 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
205 {
206 	acpi_status status;
207 	struct acpi_object_list input;
208 	union acpi_object in_params[4];
209 	union acpi_object *out_obj;
210 	u8 uuid[16];
211 	u32 errors;
212 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
213 
214 	if (!context)
215 		return AE_ERROR;
216 	if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
217 		return AE_ERROR;
218 	context->ret.length = ACPI_ALLOCATE_BUFFER;
219 	context->ret.pointer = NULL;
220 
221 	/* Setting up input parameters */
222 	input.count = 4;
223 	input.pointer = in_params;
224 	in_params[0].type 		= ACPI_TYPE_BUFFER;
225 	in_params[0].buffer.length 	= 16;
226 	in_params[0].buffer.pointer	= uuid;
227 	in_params[1].type 		= ACPI_TYPE_INTEGER;
228 	in_params[1].integer.value 	= context->rev;
229 	in_params[2].type 		= ACPI_TYPE_INTEGER;
230 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
231 	in_params[3].type		= ACPI_TYPE_BUFFER;
232 	in_params[3].buffer.length 	= context->cap.length;
233 	in_params[3].buffer.pointer 	= context->cap.pointer;
234 
235 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
236 	if (ACPI_FAILURE(status))
237 		return status;
238 
239 	if (!output.length)
240 		return AE_NULL_OBJECT;
241 
242 	out_obj = output.pointer;
243 	if (out_obj->type != ACPI_TYPE_BUFFER
244 		|| out_obj->buffer.length != context->cap.length) {
245 		acpi_print_osc_error(handle, context,
246 			"_OSC evaluation returned wrong type");
247 		status = AE_TYPE;
248 		goto out_kfree;
249 	}
250 	/* Need to ignore the bit0 in result code */
251 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
252 	if (errors) {
253 		if (errors & OSC_REQUEST_ERROR)
254 			acpi_print_osc_error(handle, context,
255 				"_OSC request failed");
256 		if (errors & OSC_INVALID_UUID_ERROR)
257 			acpi_print_osc_error(handle, context,
258 				"_OSC invalid UUID");
259 		if (errors & OSC_INVALID_REVISION_ERROR)
260 			acpi_print_osc_error(handle, context,
261 				"_OSC invalid revision");
262 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
263 			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
264 			    & OSC_QUERY_ENABLE)
265 				goto out_success;
266 			status = AE_SUPPORT;
267 			goto out_kfree;
268 		}
269 		status = AE_ERROR;
270 		goto out_kfree;
271 	}
272 out_success:
273 	context->ret.length = out_obj->buffer.length;
274 	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
275 				       context->ret.length, GFP_KERNEL);
276 	if (!context->ret.pointer) {
277 		status =  AE_NO_MEMORY;
278 		goto out_kfree;
279 	}
280 	status =  AE_OK;
281 
282 out_kfree:
283 	kfree(output.pointer);
284 	if (status != AE_OK)
285 		context->ret.pointer = NULL;
286 	return status;
287 }
288 EXPORT_SYMBOL(acpi_run_osc);
289 
290 bool osc_sb_apei_support_acked;
291 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
292 static void acpi_bus_osc_support(void)
293 {
294 	u32 capbuf[2];
295 	struct acpi_osc_context context = {
296 		.uuid_str = sb_uuid_str,
297 		.rev = 1,
298 		.cap.length = 8,
299 		.cap.pointer = capbuf,
300 	};
301 	acpi_handle handle;
302 
303 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
304 	capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
305 #if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
306 			defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
307 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
308 #endif
309 
310 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
311 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
312 #endif
313 
314 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
315 
316 	if (!ghes_disable)
317 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
318 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
319 		return;
320 	if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
321 		u32 *capbuf_ret = context.ret.pointer;
322 		if (context.ret.length > OSC_SUPPORT_DWORD)
323 			osc_sb_apei_support_acked =
324 				capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
325 		kfree(context.ret.pointer);
326 	}
327 	/* do we need to check other returned cap? Sounds no */
328 }
329 
330 /* --------------------------------------------------------------------------
331                              Notification Handling
332    -------------------------------------------------------------------------- */
333 
334 /**
335  * acpi_bus_notify
336  * ---------------
337  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
338  */
339 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
340 {
341 	struct acpi_device *adev;
342 	struct acpi_driver *driver;
343 	acpi_status status;
344 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
345 
346 	switch (type) {
347 	case ACPI_NOTIFY_BUS_CHECK:
348 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
349 		break;
350 
351 	case ACPI_NOTIFY_DEVICE_CHECK:
352 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
353 		break;
354 
355 	case ACPI_NOTIFY_DEVICE_WAKE:
356 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
357 		break;
358 
359 	case ACPI_NOTIFY_EJECT_REQUEST:
360 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
361 		break;
362 
363 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
364 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
365 		/* TBD: Exactly what does 'light' mean? */
366 		break;
367 
368 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
369 		acpi_handle_err(handle, "Device cannot be configured due "
370 				"to a frequency mismatch\n");
371 		break;
372 
373 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
374 		acpi_handle_err(handle, "Device cannot be configured due "
375 				"to a bus mode mismatch\n");
376 		break;
377 
378 	case ACPI_NOTIFY_POWER_FAULT:
379 		acpi_handle_err(handle, "Device has suffered a power fault\n");
380 		break;
381 
382 	default:
383 		acpi_handle_warn(handle, "Unsupported event type 0x%x\n", type);
384 		ost_code = ACPI_OST_SC_UNRECOGNIZED_NOTIFY;
385 		goto err;
386 	}
387 
388 	adev = acpi_bus_get_acpi_device(handle);
389 	if (!adev)
390 		goto err;
391 
392 	driver = adev->driver;
393 	if (driver && driver->ops.notify &&
394 	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
395 		driver->ops.notify(adev, type);
396 
397 	switch (type) {
398 	case ACPI_NOTIFY_BUS_CHECK:
399 	case ACPI_NOTIFY_DEVICE_CHECK:
400 	case ACPI_NOTIFY_EJECT_REQUEST:
401 		status = acpi_hotplug_schedule(adev, type);
402 		if (ACPI_SUCCESS(status))
403 			return;
404 	default:
405 		break;
406 	}
407 	acpi_bus_put_acpi_device(adev);
408 	return;
409 
410  err:
411 	acpi_evaluate_ost(handle, type, ost_code, NULL);
412 }
413 
414 /* --------------------------------------------------------------------------
415                              Initialization/Cleanup
416    -------------------------------------------------------------------------- */
417 
418 static int __init acpi_bus_init_irq(void)
419 {
420 	acpi_status status;
421 	char *message = NULL;
422 
423 
424 	/*
425 	 * Let the system know what interrupt model we are using by
426 	 * evaluating the \_PIC object, if exists.
427 	 */
428 
429 	switch (acpi_irq_model) {
430 	case ACPI_IRQ_MODEL_PIC:
431 		message = "PIC";
432 		break;
433 	case ACPI_IRQ_MODEL_IOAPIC:
434 		message = "IOAPIC";
435 		break;
436 	case ACPI_IRQ_MODEL_IOSAPIC:
437 		message = "IOSAPIC";
438 		break;
439 	case ACPI_IRQ_MODEL_PLATFORM:
440 		message = "platform specific model";
441 		break;
442 	default:
443 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
444 		return -ENODEV;
445 	}
446 
447 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
448 
449 	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
450 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
451 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
452 		return -ENODEV;
453 	}
454 
455 	return 0;
456 }
457 
458 u8 acpi_gbl_permanent_mmap;
459 
460 
461 void __init acpi_early_init(void)
462 {
463 	acpi_status status;
464 
465 	if (acpi_disabled)
466 		return;
467 
468 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
469 
470 	/* enable workarounds, unless strict ACPI spec. compliance */
471 	if (!acpi_strict)
472 		acpi_gbl_enable_interpreter_slack = TRUE;
473 
474 	acpi_gbl_permanent_mmap = 1;
475 
476 	/*
477 	 * If the machine falls into the DMI check table,
478 	 * DSDT will be copied to memory
479 	 */
480 	dmi_check_system(dsdt_dmi_table);
481 
482 	status = acpi_reallocate_root_table();
483 	if (ACPI_FAILURE(status)) {
484 		printk(KERN_ERR PREFIX
485 		       "Unable to reallocate ACPI tables\n");
486 		goto error0;
487 	}
488 
489 	status = acpi_initialize_subsystem();
490 	if (ACPI_FAILURE(status)) {
491 		printk(KERN_ERR PREFIX
492 		       "Unable to initialize the ACPI Interpreter\n");
493 		goto error0;
494 	}
495 
496 	status = acpi_load_tables();
497 	if (ACPI_FAILURE(status)) {
498 		printk(KERN_ERR PREFIX
499 		       "Unable to load the System Description Tables\n");
500 		goto error0;
501 	}
502 
503 #ifdef CONFIG_X86
504 	if (!acpi_ioapic) {
505 		/* compatible (0) means level (3) */
506 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
507 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
508 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
509 		}
510 		/* Set PIC-mode SCI trigger type */
511 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
512 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
513 	} else {
514 		/*
515 		 * now that acpi_gbl_FADT is initialized,
516 		 * update it with result from INT_SRC_OVR parsing
517 		 */
518 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
519 	}
520 #endif
521 
522 	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
523 	if (ACPI_FAILURE(status)) {
524 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
525 		goto error0;
526 	}
527 
528 	/*
529 	 * If the system is using ACPI then we can be reasonably
530 	 * confident that any regulators are managed by the firmware
531 	 * so tell the regulator core it has everything it needs to
532 	 * know.
533 	 */
534 	regulator_has_full_constraints();
535 
536 	return;
537 
538       error0:
539 	disable_acpi();
540 	return;
541 }
542 
543 static int __init acpi_bus_init(void)
544 {
545 	int result;
546 	acpi_status status;
547 
548 	acpi_os_initialize1();
549 
550 	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
551 	if (ACPI_FAILURE(status)) {
552 		printk(KERN_ERR PREFIX
553 		       "Unable to start the ACPI Interpreter\n");
554 		goto error1;
555 	}
556 
557 	/*
558 	 * ACPI 2.0 requires the EC driver to be loaded and work before
559 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
560 	 * is called).
561 	 *
562 	 * This is accomplished by looking for the ECDT table, and getting
563 	 * the EC parameters out of that.
564 	 */
565 	status = acpi_ec_ecdt_probe();
566 	/* Ignore result. Not having an ECDT is not fatal. */
567 
568 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
569 	if (ACPI_FAILURE(status)) {
570 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
571 		goto error1;
572 	}
573 
574 	/*
575 	 * _OSC method may exist in module level code,
576 	 * so it must be run after ACPI_FULL_INITIALIZATION
577 	 */
578 	acpi_bus_osc_support();
579 
580 	/*
581 	 * _PDC control method may load dynamic SSDT tables,
582 	 * and we need to install the table handler before that.
583 	 */
584 	acpi_sysfs_init();
585 
586 	acpi_early_processor_set_pdc();
587 
588 	/*
589 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
590 	 * is necessary to enable it as early as possible.
591 	 */
592 	acpi_boot_ec_enable();
593 
594 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
595 
596 	/* Initialize sleep structures */
597 	acpi_sleep_init();
598 
599 	/*
600 	 * Get the system interrupt model and evaluate \_PIC.
601 	 */
602 	result = acpi_bus_init_irq();
603 	if (result)
604 		goto error1;
605 
606 	/*
607 	 * Register the for all standard device notifications.
608 	 */
609 	status =
610 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
611 					&acpi_bus_notify, NULL);
612 	if (ACPI_FAILURE(status)) {
613 		printk(KERN_ERR PREFIX
614 		       "Unable to register for device notifications\n");
615 		goto error1;
616 	}
617 
618 	/*
619 	 * Create the top ACPI proc directory
620 	 */
621 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
622 
623 	return 0;
624 
625 	/* Mimic structured exception handling */
626       error1:
627 	acpi_terminate();
628 	return -ENODEV;
629 }
630 
631 struct kobject *acpi_kobj;
632 EXPORT_SYMBOL_GPL(acpi_kobj);
633 
634 static int __init acpi_init(void)
635 {
636 	int result;
637 
638 	if (acpi_disabled) {
639 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
640 		return -ENODEV;
641 	}
642 
643 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
644 	if (!acpi_kobj) {
645 		printk(KERN_WARNING "%s: kset create error\n", __func__);
646 		acpi_kobj = NULL;
647 	}
648 
649 	init_acpi_device_notify();
650 	result = acpi_bus_init();
651 	if (result) {
652 		disable_acpi();
653 		return result;
654 	}
655 
656 	pci_mmcfg_late_init();
657 	acpi_scan_init();
658 	acpi_ec_init();
659 	acpi_debugfs_init();
660 	acpi_sleep_proc_init();
661 	acpi_wakeup_device_init();
662 	return 0;
663 }
664 
665 subsys_initcall(acpi_init);
666