xref: /openbmc/linux/drivers/acpi/bus.c (revision db181ce0)
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 #ifdef CONFIG_ACPI_CUSTOM_DSDT
56 static inline int set_copy_dsdt(const struct dmi_system_id *id)
57 {
58 	return 0;
59 }
60 #else
61 static int set_copy_dsdt(const struct dmi_system_id *id)
62 {
63 	printk(KERN_NOTICE "%s detected - "
64 		"force copy of DSDT to local memory\n", id->ident);
65 	acpi_gbl_copy_dsdt_locally = 1;
66 	return 0;
67 }
68 #endif
69 
70 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
71 	/*
72 	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
73 	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
74 	 */
75 	{
76 	 .callback = set_copy_dsdt,
77 	 .ident = "TOSHIBA Satellite",
78 	 .matches = {
79 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
80 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
81 		},
82 	},
83 	{}
84 };
85 #else
86 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
87 	{}
88 };
89 #endif
90 
91 /* --------------------------------------------------------------------------
92                                 Device Management
93    -------------------------------------------------------------------------- */
94 
95 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
96 				       unsigned long long *sta)
97 {
98 	acpi_status status;
99 
100 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
101 	if (ACPI_SUCCESS(status))
102 		return AE_OK;
103 
104 	if (status == AE_NOT_FOUND) {
105 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
106 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
107 		return AE_OK;
108 	}
109 	return status;
110 }
111 
112 int acpi_bus_get_status(struct acpi_device *device)
113 {
114 	acpi_status status;
115 	unsigned long long sta;
116 
117 	status = acpi_bus_get_status_handle(device->handle, &sta);
118 	if (ACPI_FAILURE(status))
119 		return -ENODEV;
120 
121 	acpi_set_device_status(device, sta);
122 
123 	if (device->status.functional && !device->status.present) {
124 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
125 		       "functional but not present;\n",
126 			device->pnp.bus_id, (u32)sta));
127 	}
128 
129 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
130 			  device->pnp.bus_id, (u32)sta));
131 	return 0;
132 }
133 EXPORT_SYMBOL(acpi_bus_get_status);
134 
135 void acpi_bus_private_data_handler(acpi_handle handle,
136 				   void *context)
137 {
138 	return;
139 }
140 EXPORT_SYMBOL(acpi_bus_private_data_handler);
141 
142 int acpi_bus_attach_private_data(acpi_handle handle, void *data)
143 {
144 	acpi_status status;
145 
146 	status = acpi_attach_data(handle,
147 			acpi_bus_private_data_handler, data);
148 	if (ACPI_FAILURE(status)) {
149 		acpi_handle_debug(handle, "Error attaching device data\n");
150 		return -ENODEV;
151 	}
152 
153 	return 0;
154 }
155 EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);
156 
157 int acpi_bus_get_private_data(acpi_handle handle, void **data)
158 {
159 	acpi_status status;
160 
161 	if (!*data)
162 		return -EINVAL;
163 
164 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
165 	if (ACPI_FAILURE(status)) {
166 		acpi_handle_debug(handle, "No context for object\n");
167 		return -ENODEV;
168 	}
169 
170 	return 0;
171 }
172 EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);
173 
174 void acpi_bus_detach_private_data(acpi_handle handle)
175 {
176 	acpi_detach_data(handle, acpi_bus_private_data_handler);
177 }
178 EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
179 
180 void acpi_bus_no_hotplug(acpi_handle handle)
181 {
182 	struct acpi_device *adev = NULL;
183 
184 	acpi_bus_get_device(handle, &adev);
185 	if (adev)
186 		adev->flags.no_hotplug = true;
187 }
188 EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
189 
190 static void acpi_print_osc_error(acpi_handle handle,
191 	struct acpi_osc_context *context, char *error)
192 {
193 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
194 	int i;
195 
196 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
197 		printk(KERN_DEBUG "%s\n", error);
198 	else {
199 		printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
200 		kfree(buffer.pointer);
201 	}
202 	printk(KERN_DEBUG"_OSC request data:");
203 	for (i = 0; i < context->cap.length; i += sizeof(u32))
204 		printk("%x ", *((u32 *)(context->cap.pointer + i)));
205 	printk("\n");
206 }
207 
208 acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
209 {
210 	int i;
211 	static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
212 		24, 26, 28, 30, 32, 34};
213 
214 	if (strlen(str) != 36)
215 		return AE_BAD_PARAMETER;
216 	for (i = 0; i < 36; i++) {
217 		if (i == 8 || i == 13 || i == 18 || i == 23) {
218 			if (str[i] != '-')
219 				return AE_BAD_PARAMETER;
220 		} else if (!isxdigit(str[i]))
221 			return AE_BAD_PARAMETER;
222 	}
223 	for (i = 0; i < 16; i++) {
224 		uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
225 		uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
226 	}
227 	return AE_OK;
228 }
229 EXPORT_SYMBOL_GPL(acpi_str_to_uuid);
230 
231 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
232 {
233 	acpi_status status;
234 	struct acpi_object_list input;
235 	union acpi_object in_params[4];
236 	union acpi_object *out_obj;
237 	u8 uuid[16];
238 	u32 errors;
239 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
240 
241 	if (!context)
242 		return AE_ERROR;
243 	if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
244 		return AE_ERROR;
245 	context->ret.length = ACPI_ALLOCATE_BUFFER;
246 	context->ret.pointer = NULL;
247 
248 	/* Setting up input parameters */
249 	input.count = 4;
250 	input.pointer = in_params;
251 	in_params[0].type 		= ACPI_TYPE_BUFFER;
252 	in_params[0].buffer.length 	= 16;
253 	in_params[0].buffer.pointer	= uuid;
254 	in_params[1].type 		= ACPI_TYPE_INTEGER;
255 	in_params[1].integer.value 	= context->rev;
256 	in_params[2].type 		= ACPI_TYPE_INTEGER;
257 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
258 	in_params[3].type		= ACPI_TYPE_BUFFER;
259 	in_params[3].buffer.length 	= context->cap.length;
260 	in_params[3].buffer.pointer 	= context->cap.pointer;
261 
262 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
263 	if (ACPI_FAILURE(status))
264 		return status;
265 
266 	if (!output.length)
267 		return AE_NULL_OBJECT;
268 
269 	out_obj = output.pointer;
270 	if (out_obj->type != ACPI_TYPE_BUFFER
271 		|| out_obj->buffer.length != context->cap.length) {
272 		acpi_print_osc_error(handle, context,
273 			"_OSC evaluation returned wrong type");
274 		status = AE_TYPE;
275 		goto out_kfree;
276 	}
277 	/* Need to ignore the bit0 in result code */
278 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
279 	if (errors) {
280 		if (errors & OSC_REQUEST_ERROR)
281 			acpi_print_osc_error(handle, context,
282 				"_OSC request failed");
283 		if (errors & OSC_INVALID_UUID_ERROR)
284 			acpi_print_osc_error(handle, context,
285 				"_OSC invalid UUID");
286 		if (errors & OSC_INVALID_REVISION_ERROR)
287 			acpi_print_osc_error(handle, context,
288 				"_OSC invalid revision");
289 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
290 			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
291 			    & OSC_QUERY_ENABLE)
292 				goto out_success;
293 			status = AE_SUPPORT;
294 			goto out_kfree;
295 		}
296 		status = AE_ERROR;
297 		goto out_kfree;
298 	}
299 out_success:
300 	context->ret.length = out_obj->buffer.length;
301 	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
302 				       context->ret.length, GFP_KERNEL);
303 	if (!context->ret.pointer) {
304 		status =  AE_NO_MEMORY;
305 		goto out_kfree;
306 	}
307 	status =  AE_OK;
308 
309 out_kfree:
310 	kfree(output.pointer);
311 	if (status != AE_OK)
312 		context->ret.pointer = NULL;
313 	return status;
314 }
315 EXPORT_SYMBOL(acpi_run_osc);
316 
317 bool osc_sb_apei_support_acked;
318 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
319 static void acpi_bus_osc_support(void)
320 {
321 	u32 capbuf[2];
322 	struct acpi_osc_context context = {
323 		.uuid_str = sb_uuid_str,
324 		.rev = 1,
325 		.cap.length = 8,
326 		.cap.pointer = capbuf,
327 	};
328 	acpi_handle handle;
329 
330 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
331 	capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
332 #if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
333 			defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
334 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
335 #endif
336 
337 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
338 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
339 #endif
340 
341 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
342 
343 	if (!ghes_disable)
344 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
345 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
346 		return;
347 	if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
348 		u32 *capbuf_ret = context.ret.pointer;
349 		if (context.ret.length > OSC_SUPPORT_DWORD)
350 			osc_sb_apei_support_acked =
351 				capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
352 		kfree(context.ret.pointer);
353 	}
354 	/* do we need to check other returned cap? Sounds no */
355 }
356 
357 /* --------------------------------------------------------------------------
358                              Notification Handling
359    -------------------------------------------------------------------------- */
360 
361 /**
362  * acpi_bus_notify
363  * ---------------
364  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
365  */
366 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
367 {
368 	struct acpi_device *adev;
369 	struct acpi_driver *driver;
370 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
371 	bool hotplug_event = false;
372 
373 	switch (type) {
374 	case ACPI_NOTIFY_BUS_CHECK:
375 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
376 		hotplug_event = true;
377 		break;
378 
379 	case ACPI_NOTIFY_DEVICE_CHECK:
380 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
381 		hotplug_event = true;
382 		break;
383 
384 	case ACPI_NOTIFY_DEVICE_WAKE:
385 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
386 		break;
387 
388 	case ACPI_NOTIFY_EJECT_REQUEST:
389 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
390 		hotplug_event = true;
391 		break;
392 
393 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
394 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
395 		/* TBD: Exactly what does 'light' mean? */
396 		break;
397 
398 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
399 		acpi_handle_err(handle, "Device cannot be configured due "
400 				"to a frequency mismatch\n");
401 		break;
402 
403 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
404 		acpi_handle_err(handle, "Device cannot be configured due "
405 				"to a bus mode mismatch\n");
406 		break;
407 
408 	case ACPI_NOTIFY_POWER_FAULT:
409 		acpi_handle_err(handle, "Device has suffered a power fault\n");
410 		break;
411 
412 	default:
413 		acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
414 		break;
415 	}
416 
417 	adev = acpi_bus_get_acpi_device(handle);
418 	if (!adev)
419 		goto err;
420 
421 	driver = adev->driver;
422 	if (driver && driver->ops.notify &&
423 	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
424 		driver->ops.notify(adev, type);
425 
426 	if (hotplug_event && ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
427 		return;
428 
429 	acpi_bus_put_acpi_device(adev);
430 	return;
431 
432  err:
433 	acpi_evaluate_ost(handle, type, ost_code, NULL);
434 }
435 
436 /* --------------------------------------------------------------------------
437                              Initialization/Cleanup
438    -------------------------------------------------------------------------- */
439 
440 static int __init acpi_bus_init_irq(void)
441 {
442 	acpi_status status;
443 	char *message = NULL;
444 
445 
446 	/*
447 	 * Let the system know what interrupt model we are using by
448 	 * evaluating the \_PIC object, if exists.
449 	 */
450 
451 	switch (acpi_irq_model) {
452 	case ACPI_IRQ_MODEL_PIC:
453 		message = "PIC";
454 		break;
455 	case ACPI_IRQ_MODEL_IOAPIC:
456 		message = "IOAPIC";
457 		break;
458 	case ACPI_IRQ_MODEL_IOSAPIC:
459 		message = "IOSAPIC";
460 		break;
461 	case ACPI_IRQ_MODEL_PLATFORM:
462 		message = "platform specific model";
463 		break;
464 	default:
465 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
466 		return -ENODEV;
467 	}
468 
469 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
470 
471 	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
472 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
473 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
474 		return -ENODEV;
475 	}
476 
477 	return 0;
478 }
479 
480 u8 acpi_gbl_permanent_mmap;
481 
482 
483 void __init acpi_early_init(void)
484 {
485 	acpi_status status;
486 
487 	if (acpi_disabled)
488 		return;
489 
490 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
491 
492 	/* It's safe to verify table checksums during late stage */
493 	acpi_gbl_verify_table_checksum = TRUE;
494 
495 	/* enable workarounds, unless strict ACPI spec. compliance */
496 	if (!acpi_strict)
497 		acpi_gbl_enable_interpreter_slack = TRUE;
498 
499 	acpi_gbl_permanent_mmap = 1;
500 
501 	/*
502 	 * If the machine falls into the DMI check table,
503 	 * DSDT will be copied to memory
504 	 */
505 	dmi_check_system(dsdt_dmi_table);
506 
507 	status = acpi_reallocate_root_table();
508 	if (ACPI_FAILURE(status)) {
509 		printk(KERN_ERR PREFIX
510 		       "Unable to reallocate ACPI tables\n");
511 		goto error0;
512 	}
513 
514 	status = acpi_initialize_subsystem();
515 	if (ACPI_FAILURE(status)) {
516 		printk(KERN_ERR PREFIX
517 		       "Unable to initialize the ACPI Interpreter\n");
518 		goto error0;
519 	}
520 
521 	status = acpi_load_tables();
522 	if (ACPI_FAILURE(status)) {
523 		printk(KERN_ERR PREFIX
524 		       "Unable to load the System Description Tables\n");
525 		goto error0;
526 	}
527 
528 #ifdef CONFIG_X86
529 	if (!acpi_ioapic) {
530 		/* compatible (0) means level (3) */
531 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
532 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
533 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
534 		}
535 		/* Set PIC-mode SCI trigger type */
536 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
537 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
538 	} else {
539 		/*
540 		 * now that acpi_gbl_FADT is initialized,
541 		 * update it with result from INT_SRC_OVR parsing
542 		 */
543 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
544 	}
545 #endif
546 
547 	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
548 	if (ACPI_FAILURE(status)) {
549 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
550 		goto error0;
551 	}
552 
553 	/*
554 	 * If the system is using ACPI then we can be reasonably
555 	 * confident that any regulators are managed by the firmware
556 	 * so tell the regulator core it has everything it needs to
557 	 * know.
558 	 */
559 	regulator_has_full_constraints();
560 
561 	return;
562 
563       error0:
564 	disable_acpi();
565 	return;
566 }
567 
568 static int __init acpi_bus_init(void)
569 {
570 	int result;
571 	acpi_status status;
572 
573 	acpi_os_initialize1();
574 
575 	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
576 	if (ACPI_FAILURE(status)) {
577 		printk(KERN_ERR PREFIX
578 		       "Unable to start the ACPI Interpreter\n");
579 		goto error1;
580 	}
581 
582 	/*
583 	 * ACPI 2.0 requires the EC driver to be loaded and work before
584 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
585 	 * is called).
586 	 *
587 	 * This is accomplished by looking for the ECDT table, and getting
588 	 * the EC parameters out of that.
589 	 */
590 	status = acpi_ec_ecdt_probe();
591 	/* Ignore result. Not having an ECDT is not fatal. */
592 
593 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
594 	if (ACPI_FAILURE(status)) {
595 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
596 		goto error1;
597 	}
598 
599 	/*
600 	 * _OSC method may exist in module level code,
601 	 * so it must be run after ACPI_FULL_INITIALIZATION
602 	 */
603 	acpi_bus_osc_support();
604 
605 	/*
606 	 * _PDC control method may load dynamic SSDT tables,
607 	 * and we need to install the table handler before that.
608 	 */
609 	acpi_sysfs_init();
610 
611 	acpi_early_processor_set_pdc();
612 
613 	/*
614 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
615 	 * is necessary to enable it as early as possible.
616 	 */
617 	acpi_boot_ec_enable();
618 
619 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
620 
621 	/* Initialize sleep structures */
622 	acpi_sleep_init();
623 
624 	/*
625 	 * Get the system interrupt model and evaluate \_PIC.
626 	 */
627 	result = acpi_bus_init_irq();
628 	if (result)
629 		goto error1;
630 
631 	/*
632 	 * Register the for all standard device notifications.
633 	 */
634 	status =
635 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
636 					&acpi_bus_notify, NULL);
637 	if (ACPI_FAILURE(status)) {
638 		printk(KERN_ERR PREFIX
639 		       "Unable to register for device notifications\n");
640 		goto error1;
641 	}
642 
643 	/*
644 	 * Create the top ACPI proc directory
645 	 */
646 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
647 
648 	return 0;
649 
650 	/* Mimic structured exception handling */
651       error1:
652 	acpi_terminate();
653 	return -ENODEV;
654 }
655 
656 struct kobject *acpi_kobj;
657 EXPORT_SYMBOL_GPL(acpi_kobj);
658 
659 static int __init acpi_init(void)
660 {
661 	int result;
662 
663 	if (acpi_disabled) {
664 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
665 		return -ENODEV;
666 	}
667 
668 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
669 	if (!acpi_kobj) {
670 		printk(KERN_WARNING "%s: kset create error\n", __func__);
671 		acpi_kobj = NULL;
672 	}
673 
674 	init_acpi_device_notify();
675 	result = acpi_bus_init();
676 	if (result) {
677 		disable_acpi();
678 		return result;
679 	}
680 
681 	pci_mmcfg_late_init();
682 	acpi_scan_init();
683 	acpi_ec_init();
684 	acpi_debugfs_init();
685 	acpi_sleep_proc_init();
686 	acpi_wakeup_device_init();
687 	return 0;
688 }
689 
690 subsys_initcall(acpi_init);
691