xref: /linux/drivers/acpi/bus.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19  */
20 
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/ioport.h>
24 #include <linux/kernel.h>
25 #include <linux/list.h>
26 #include <linux/sched.h>
27 #include <linux/pm.h>
28 #include <linux/device.h>
29 #include <linux/proc_fs.h>
30 #include <linux/acpi.h>
31 #include <linux/slab.h>
32 #include <linux/regulator/machine.h>
33 #ifdef CONFIG_X86
34 #include <asm/mpspec.h>
35 #endif
36 #include <linux/pci.h>
37 #include <acpi/apei.h>
38 #include <linux/dmi.h>
39 #include <linux/suspend.h>
40 
41 #include "internal.h"
42 
43 #define _COMPONENT		ACPI_BUS_COMPONENT
44 ACPI_MODULE_NAME("bus");
45 
46 struct acpi_device *acpi_root;
47 struct proc_dir_entry *acpi_root_dir;
48 EXPORT_SYMBOL(acpi_root_dir);
49 
50 #ifdef CONFIG_X86
51 #ifdef CONFIG_ACPI_CUSTOM_DSDT
52 static inline int set_copy_dsdt(const struct dmi_system_id *id)
53 {
54 	return 0;
55 }
56 #else
57 static int set_copy_dsdt(const struct dmi_system_id *id)
58 {
59 	printk(KERN_NOTICE "%s detected - "
60 		"force copy of DSDT to local memory\n", id->ident);
61 	acpi_gbl_copy_dsdt_locally = 1;
62 	return 0;
63 }
64 #endif
65 
66 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
67 	/*
68 	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
69 	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
70 	 */
71 	{
72 	 .callback = set_copy_dsdt,
73 	 .ident = "TOSHIBA Satellite",
74 	 .matches = {
75 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
76 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
77 		},
78 	},
79 	{}
80 };
81 #else
82 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
83 	{}
84 };
85 #endif
86 
87 /* --------------------------------------------------------------------------
88                                 Device Management
89    -------------------------------------------------------------------------- */
90 
91 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
92 				       unsigned long long *sta)
93 {
94 	acpi_status status;
95 
96 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
97 	if (ACPI_SUCCESS(status))
98 		return AE_OK;
99 
100 	if (status == AE_NOT_FOUND) {
101 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
102 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
103 		return AE_OK;
104 	}
105 	return status;
106 }
107 
108 int acpi_bus_get_status(struct acpi_device *device)
109 {
110 	acpi_status status;
111 	unsigned long long sta;
112 
113 	status = acpi_bus_get_status_handle(device->handle, &sta);
114 	if (ACPI_FAILURE(status))
115 		return -ENODEV;
116 
117 	acpi_set_device_status(device, sta);
118 
119 	if (device->status.functional && !device->status.present) {
120 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
121 		       "functional but not present;\n",
122 			device->pnp.bus_id, (u32)sta));
123 	}
124 
125 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
126 			  device->pnp.bus_id, (u32)sta));
127 	return 0;
128 }
129 EXPORT_SYMBOL(acpi_bus_get_status);
130 
131 void acpi_bus_private_data_handler(acpi_handle handle,
132 				   void *context)
133 {
134 	return;
135 }
136 EXPORT_SYMBOL(acpi_bus_private_data_handler);
137 
138 int acpi_bus_attach_private_data(acpi_handle handle, void *data)
139 {
140 	acpi_status status;
141 
142 	status = acpi_attach_data(handle,
143 			acpi_bus_private_data_handler, data);
144 	if (ACPI_FAILURE(status)) {
145 		acpi_handle_debug(handle, "Error attaching device data\n");
146 		return -ENODEV;
147 	}
148 
149 	return 0;
150 }
151 EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);
152 
153 int acpi_bus_get_private_data(acpi_handle handle, void **data)
154 {
155 	acpi_status status;
156 
157 	if (!*data)
158 		return -EINVAL;
159 
160 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
161 	if (ACPI_FAILURE(status)) {
162 		acpi_handle_debug(handle, "No context for object\n");
163 		return -ENODEV;
164 	}
165 
166 	return 0;
167 }
168 EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);
169 
170 void acpi_bus_detach_private_data(acpi_handle handle)
171 {
172 	acpi_detach_data(handle, acpi_bus_private_data_handler);
173 }
174 EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
175 
176 static void acpi_print_osc_error(acpi_handle handle,
177 	struct acpi_osc_context *context, char *error)
178 {
179 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
180 	int i;
181 
182 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
183 		printk(KERN_DEBUG "%s\n", error);
184 	else {
185 		printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
186 		kfree(buffer.pointer);
187 	}
188 	printk(KERN_DEBUG"_OSC request data:");
189 	for (i = 0; i < context->cap.length; i += sizeof(u32))
190 		printk("%x ", *((u32 *)(context->cap.pointer + i)));
191 	printk("\n");
192 }
193 
194 acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
195 {
196 	int i;
197 	static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
198 		24, 26, 28, 30, 32, 34};
199 
200 	if (strlen(str) != 36)
201 		return AE_BAD_PARAMETER;
202 	for (i = 0; i < 36; i++) {
203 		if (i == 8 || i == 13 || i == 18 || i == 23) {
204 			if (str[i] != '-')
205 				return AE_BAD_PARAMETER;
206 		} else if (!isxdigit(str[i]))
207 			return AE_BAD_PARAMETER;
208 	}
209 	for (i = 0; i < 16; i++) {
210 		uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
211 		uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
212 	}
213 	return AE_OK;
214 }
215 EXPORT_SYMBOL_GPL(acpi_str_to_uuid);
216 
217 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
218 {
219 	acpi_status status;
220 	struct acpi_object_list input;
221 	union acpi_object in_params[4];
222 	union acpi_object *out_obj;
223 	u8 uuid[16];
224 	u32 errors;
225 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
226 
227 	if (!context)
228 		return AE_ERROR;
229 	if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
230 		return AE_ERROR;
231 	context->ret.length = ACPI_ALLOCATE_BUFFER;
232 	context->ret.pointer = NULL;
233 
234 	/* Setting up input parameters */
235 	input.count = 4;
236 	input.pointer = in_params;
237 	in_params[0].type 		= ACPI_TYPE_BUFFER;
238 	in_params[0].buffer.length 	= 16;
239 	in_params[0].buffer.pointer	= uuid;
240 	in_params[1].type 		= ACPI_TYPE_INTEGER;
241 	in_params[1].integer.value 	= context->rev;
242 	in_params[2].type 		= ACPI_TYPE_INTEGER;
243 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
244 	in_params[3].type		= ACPI_TYPE_BUFFER;
245 	in_params[3].buffer.length 	= context->cap.length;
246 	in_params[3].buffer.pointer 	= context->cap.pointer;
247 
248 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
249 	if (ACPI_FAILURE(status))
250 		return status;
251 
252 	if (!output.length)
253 		return AE_NULL_OBJECT;
254 
255 	out_obj = output.pointer;
256 	if (out_obj->type != ACPI_TYPE_BUFFER
257 		|| out_obj->buffer.length != context->cap.length) {
258 		acpi_print_osc_error(handle, context,
259 			"_OSC evaluation returned wrong type");
260 		status = AE_TYPE;
261 		goto out_kfree;
262 	}
263 	/* Need to ignore the bit0 in result code */
264 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
265 	if (errors) {
266 		if (errors & OSC_REQUEST_ERROR)
267 			acpi_print_osc_error(handle, context,
268 				"_OSC request failed");
269 		if (errors & OSC_INVALID_UUID_ERROR)
270 			acpi_print_osc_error(handle, context,
271 				"_OSC invalid UUID");
272 		if (errors & OSC_INVALID_REVISION_ERROR)
273 			acpi_print_osc_error(handle, context,
274 				"_OSC invalid revision");
275 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
276 			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
277 			    & OSC_QUERY_ENABLE)
278 				goto out_success;
279 			status = AE_SUPPORT;
280 			goto out_kfree;
281 		}
282 		status = AE_ERROR;
283 		goto out_kfree;
284 	}
285 out_success:
286 	context->ret.length = out_obj->buffer.length;
287 	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
288 				       context->ret.length, GFP_KERNEL);
289 	if (!context->ret.pointer) {
290 		status =  AE_NO_MEMORY;
291 		goto out_kfree;
292 	}
293 	status =  AE_OK;
294 
295 out_kfree:
296 	kfree(output.pointer);
297 	if (status != AE_OK)
298 		context->ret.pointer = NULL;
299 	return status;
300 }
301 EXPORT_SYMBOL(acpi_run_osc);
302 
303 bool osc_sb_apei_support_acked;
304 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
305 static void acpi_bus_osc_support(void)
306 {
307 	u32 capbuf[2];
308 	struct acpi_osc_context context = {
309 		.uuid_str = sb_uuid_str,
310 		.rev = 1,
311 		.cap.length = 8,
312 		.cap.pointer = capbuf,
313 	};
314 	acpi_handle handle;
315 
316 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
317 	capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
318 	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR_AGGREGATOR))
319 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
320 	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR))
321 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
322 
323 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
324 
325 	if (!ghes_disable)
326 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
327 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
328 		return;
329 	if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
330 		u32 *capbuf_ret = context.ret.pointer;
331 		if (context.ret.length > OSC_SUPPORT_DWORD)
332 			osc_sb_apei_support_acked =
333 				capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
334 		kfree(context.ret.pointer);
335 	}
336 	/* do we need to check other returned cap? Sounds no */
337 }
338 
339 /* --------------------------------------------------------------------------
340                              Notification Handling
341    -------------------------------------------------------------------------- */
342 
343 /**
344  * acpi_bus_notify
345  * ---------------
346  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
347  */
348 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
349 {
350 	struct acpi_device *adev;
351 	struct acpi_driver *driver;
352 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
353 	bool hotplug_event = false;
354 
355 	switch (type) {
356 	case ACPI_NOTIFY_BUS_CHECK:
357 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
358 		hotplug_event = true;
359 		break;
360 
361 	case ACPI_NOTIFY_DEVICE_CHECK:
362 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
363 		hotplug_event = true;
364 		break;
365 
366 	case ACPI_NOTIFY_DEVICE_WAKE:
367 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
368 		break;
369 
370 	case ACPI_NOTIFY_EJECT_REQUEST:
371 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
372 		hotplug_event = true;
373 		break;
374 
375 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
376 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
377 		/* TBD: Exactly what does 'light' mean? */
378 		break;
379 
380 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
381 		acpi_handle_err(handle, "Device cannot be configured due "
382 				"to a frequency mismatch\n");
383 		break;
384 
385 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
386 		acpi_handle_err(handle, "Device cannot be configured due "
387 				"to a bus mode mismatch\n");
388 		break;
389 
390 	case ACPI_NOTIFY_POWER_FAULT:
391 		acpi_handle_err(handle, "Device has suffered a power fault\n");
392 		break;
393 
394 	default:
395 		acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
396 		break;
397 	}
398 
399 	adev = acpi_bus_get_acpi_device(handle);
400 	if (!adev)
401 		goto err;
402 
403 	driver = adev->driver;
404 	if (driver && driver->ops.notify &&
405 	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
406 		driver->ops.notify(adev, type);
407 
408 	if (hotplug_event && ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
409 		return;
410 
411 	acpi_bus_put_acpi_device(adev);
412 	return;
413 
414  err:
415 	acpi_evaluate_ost(handle, type, ost_code, NULL);
416 }
417 
418 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
419 {
420 	struct acpi_device *device = data;
421 
422 	device->driver->ops.notify(device, event);
423 }
424 
425 static void acpi_device_notify_fixed(void *data)
426 {
427 	struct acpi_device *device = data;
428 
429 	/* Fixed hardware devices have no handles */
430 	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
431 }
432 
433 static u32 acpi_device_fixed_event(void *data)
434 {
435 	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
436 	return ACPI_INTERRUPT_HANDLED;
437 }
438 
439 static int acpi_device_install_notify_handler(struct acpi_device *device)
440 {
441 	acpi_status status;
442 
443 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
444 		status =
445 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
446 						     acpi_device_fixed_event,
447 						     device);
448 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
449 		status =
450 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
451 						     acpi_device_fixed_event,
452 						     device);
453 	else
454 		status = acpi_install_notify_handler(device->handle,
455 						     ACPI_DEVICE_NOTIFY,
456 						     acpi_device_notify,
457 						     device);
458 
459 	if (ACPI_FAILURE(status))
460 		return -EINVAL;
461 	return 0;
462 }
463 
464 static void acpi_device_remove_notify_handler(struct acpi_device *device)
465 {
466 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
467 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
468 						acpi_device_fixed_event);
469 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
470 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
471 						acpi_device_fixed_event);
472 	else
473 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
474 					   acpi_device_notify);
475 }
476 
477 /* --------------------------------------------------------------------------
478                              Device Matching
479    -------------------------------------------------------------------------- */
480 
481 static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
482 						      const struct device *dev)
483 {
484 	struct mutex *physical_node_lock = &adev->physical_node_lock;
485 
486 	mutex_lock(physical_node_lock);
487 	if (list_empty(&adev->physical_node_list)) {
488 		adev = NULL;
489 	} else {
490 		const struct acpi_device_physical_node *node;
491 
492 		node = list_first_entry(&adev->physical_node_list,
493 					struct acpi_device_physical_node, node);
494 		if (node->dev != dev)
495 			adev = NULL;
496 	}
497 	mutex_unlock(physical_node_lock);
498 	return adev;
499 }
500 
501 /**
502  * acpi_device_is_first_physical_node - Is given dev first physical node
503  * @adev: ACPI companion device
504  * @dev: Physical device to check
505  *
506  * Function checks if given @dev is the first physical devices attached to
507  * the ACPI companion device. This distinction is needed in some cases
508  * where the same companion device is shared between many physical devices.
509  *
510  * Note that the caller have to provide valid @adev pointer.
511  */
512 bool acpi_device_is_first_physical_node(struct acpi_device *adev,
513 					const struct device *dev)
514 {
515 	return !!acpi_primary_dev_companion(adev, dev);
516 }
517 
518 /*
519  * acpi_companion_match() - Can we match via ACPI companion device
520  * @dev: Device in question
521  *
522  * Check if the given device has an ACPI companion and if that companion has
523  * a valid list of PNP IDs, and if the device is the first (primary) physical
524  * device associated with it.  Return the companion pointer if that's the case
525  * or NULL otherwise.
526  *
527  * If multiple physical devices are attached to a single ACPI companion, we need
528  * to be careful.  The usage scenario for this kind of relationship is that all
529  * of the physical devices in question use resources provided by the ACPI
530  * companion.  A typical case is an MFD device where all the sub-devices share
531  * the parent's ACPI companion.  In such cases we can only allow the primary
532  * (first) physical device to be matched with the help of the companion's PNP
533  * IDs.
534  *
535  * Additional physical devices sharing the ACPI companion can still use
536  * resources available from it but they will be matched normally using functions
537  * provided by their bus types (and analogously for their modalias).
538  */
539 struct acpi_device *acpi_companion_match(const struct device *dev)
540 {
541 	struct acpi_device *adev;
542 
543 	adev = ACPI_COMPANION(dev);
544 	if (!adev)
545 		return NULL;
546 
547 	if (list_empty(&adev->pnp.ids))
548 		return NULL;
549 
550 	return acpi_primary_dev_companion(adev, dev);
551 }
552 
553 /**
554  * acpi_of_match_device - Match device object using the "compatible" property.
555  * @adev: ACPI device object to match.
556  * @of_match_table: List of device IDs to match against.
557  *
558  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
559  * identifiers and a _DSD object with the "compatible" property, use that
560  * property to match against the given list of identifiers.
561  */
562 static bool acpi_of_match_device(struct acpi_device *adev,
563 				 const struct of_device_id *of_match_table)
564 {
565 	const union acpi_object *of_compatible, *obj;
566 	int i, nval;
567 
568 	if (!adev)
569 		return false;
570 
571 	of_compatible = adev->data.of_compatible;
572 	if (!of_match_table || !of_compatible)
573 		return false;
574 
575 	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
576 		nval = of_compatible->package.count;
577 		obj = of_compatible->package.elements;
578 	} else { /* Must be ACPI_TYPE_STRING. */
579 		nval = 1;
580 		obj = of_compatible;
581 	}
582 	/* Now we can look for the driver DT compatible strings */
583 	for (i = 0; i < nval; i++, obj++) {
584 		const struct of_device_id *id;
585 
586 		for (id = of_match_table; id->compatible[0]; id++)
587 			if (!strcasecmp(obj->string.pointer, id->compatible))
588 				return true;
589 	}
590 
591 	return false;
592 }
593 
594 static bool __acpi_match_device_cls(const struct acpi_device_id *id,
595 				    struct acpi_hardware_id *hwid)
596 {
597 	int i, msk, byte_shift;
598 	char buf[3];
599 
600 	if (!id->cls)
601 		return false;
602 
603 	/* Apply class-code bitmask, before checking each class-code byte */
604 	for (i = 1; i <= 3; i++) {
605 		byte_shift = 8 * (3 - i);
606 		msk = (id->cls_msk >> byte_shift) & 0xFF;
607 		if (!msk)
608 			continue;
609 
610 		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
611 		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
612 			return false;
613 	}
614 	return true;
615 }
616 
617 static const struct acpi_device_id *__acpi_match_device(
618 	struct acpi_device *device,
619 	const struct acpi_device_id *ids,
620 	const struct of_device_id *of_ids)
621 {
622 	const struct acpi_device_id *id;
623 	struct acpi_hardware_id *hwid;
624 
625 	/*
626 	 * If the device is not present, it is unnecessary to load device
627 	 * driver for it.
628 	 */
629 	if (!device || !device->status.present)
630 		return NULL;
631 
632 	list_for_each_entry(hwid, &device->pnp.ids, list) {
633 		/* First, check the ACPI/PNP IDs provided by the caller. */
634 		for (id = ids; id->id[0] || id->cls; id++) {
635 			if (id->id[0] && !strcmp((char *) id->id, hwid->id))
636 				return id;
637 			else if (id->cls && __acpi_match_device_cls(id, hwid))
638 				return id;
639 		}
640 
641 		/*
642 		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
643 		 * "compatible" property if found.
644 		 *
645 		 * The id returned by the below is not valid, but the only
646 		 * caller passing non-NULL of_ids here is only interested in
647 		 * whether or not the return value is NULL.
648 		 */
649 		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
650 		    && acpi_of_match_device(device, of_ids))
651 			return id;
652 	}
653 	return NULL;
654 }
655 
656 /**
657  * acpi_match_device - Match a struct device against a given list of ACPI IDs
658  * @ids: Array of struct acpi_device_id object to match against.
659  * @dev: The device structure to match.
660  *
661  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
662  * object for that handle and use that object to match against a given list of
663  * device IDs.
664  *
665  * Return a pointer to the first matching ID on success or %NULL on failure.
666  */
667 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
668 					       const struct device *dev)
669 {
670 	return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
671 }
672 EXPORT_SYMBOL_GPL(acpi_match_device);
673 
674 int acpi_match_device_ids(struct acpi_device *device,
675 			  const struct acpi_device_id *ids)
676 {
677 	return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
678 }
679 EXPORT_SYMBOL(acpi_match_device_ids);
680 
681 bool acpi_driver_match_device(struct device *dev,
682 			      const struct device_driver *drv)
683 {
684 	if (!drv->acpi_match_table)
685 		return acpi_of_match_device(ACPI_COMPANION(dev),
686 					    drv->of_match_table);
687 
688 	return !!__acpi_match_device(acpi_companion_match(dev),
689 				     drv->acpi_match_table, drv->of_match_table);
690 }
691 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
692 
693 /* --------------------------------------------------------------------------
694                               ACPI Driver Management
695    -------------------------------------------------------------------------- */
696 
697 /**
698  * acpi_bus_register_driver - register a driver with the ACPI bus
699  * @driver: driver being registered
700  *
701  * Registers a driver with the ACPI bus.  Searches the namespace for all
702  * devices that match the driver's criteria and binds.  Returns zero for
703  * success or a negative error status for failure.
704  */
705 int acpi_bus_register_driver(struct acpi_driver *driver)
706 {
707 	int ret;
708 
709 	if (acpi_disabled)
710 		return -ENODEV;
711 	driver->drv.name = driver->name;
712 	driver->drv.bus = &acpi_bus_type;
713 	driver->drv.owner = driver->owner;
714 
715 	ret = driver_register(&driver->drv);
716 	return ret;
717 }
718 
719 EXPORT_SYMBOL(acpi_bus_register_driver);
720 
721 /**
722  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
723  * @driver: driver to unregister
724  *
725  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
726  * devices that match the driver's criteria and unbinds.
727  */
728 void acpi_bus_unregister_driver(struct acpi_driver *driver)
729 {
730 	driver_unregister(&driver->drv);
731 }
732 
733 EXPORT_SYMBOL(acpi_bus_unregister_driver);
734 
735 /* --------------------------------------------------------------------------
736                               ACPI Bus operations
737    -------------------------------------------------------------------------- */
738 
739 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
740 {
741 	struct acpi_device *acpi_dev = to_acpi_device(dev);
742 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
743 
744 	return acpi_dev->flags.match_driver
745 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
746 }
747 
748 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
749 {
750 	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
751 }
752 
753 static int acpi_device_probe(struct device *dev)
754 {
755 	struct acpi_device *acpi_dev = to_acpi_device(dev);
756 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
757 	int ret;
758 
759 	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
760 		return -EINVAL;
761 
762 	if (!acpi_drv->ops.add)
763 		return -ENOSYS;
764 
765 	ret = acpi_drv->ops.add(acpi_dev);
766 	if (ret)
767 		return ret;
768 
769 	acpi_dev->driver = acpi_drv;
770 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
771 			  "Driver [%s] successfully bound to device [%s]\n",
772 			  acpi_drv->name, acpi_dev->pnp.bus_id));
773 
774 	if (acpi_drv->ops.notify) {
775 		ret = acpi_device_install_notify_handler(acpi_dev);
776 		if (ret) {
777 			if (acpi_drv->ops.remove)
778 				acpi_drv->ops.remove(acpi_dev);
779 
780 			acpi_dev->driver = NULL;
781 			acpi_dev->driver_data = NULL;
782 			return ret;
783 		}
784 	}
785 
786 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
787 			  acpi_drv->name, acpi_dev->pnp.bus_id));
788 	get_device(dev);
789 	return 0;
790 }
791 
792 static int acpi_device_remove(struct device * dev)
793 {
794 	struct acpi_device *acpi_dev = to_acpi_device(dev);
795 	struct acpi_driver *acpi_drv = acpi_dev->driver;
796 
797 	if (acpi_drv) {
798 		if (acpi_drv->ops.notify)
799 			acpi_device_remove_notify_handler(acpi_dev);
800 		if (acpi_drv->ops.remove)
801 			acpi_drv->ops.remove(acpi_dev);
802 	}
803 	acpi_dev->driver = NULL;
804 	acpi_dev->driver_data = NULL;
805 
806 	put_device(dev);
807 	return 0;
808 }
809 
810 struct bus_type acpi_bus_type = {
811 	.name		= "acpi",
812 	.match		= acpi_bus_match,
813 	.probe		= acpi_device_probe,
814 	.remove		= acpi_device_remove,
815 	.uevent		= acpi_device_uevent,
816 };
817 
818 /* --------------------------------------------------------------------------
819                              Initialization/Cleanup
820    -------------------------------------------------------------------------- */
821 
822 static int __init acpi_bus_init_irq(void)
823 {
824 	acpi_status status;
825 	char *message = NULL;
826 
827 
828 	/*
829 	 * Let the system know what interrupt model we are using by
830 	 * evaluating the \_PIC object, if exists.
831 	 */
832 
833 	switch (acpi_irq_model) {
834 	case ACPI_IRQ_MODEL_PIC:
835 		message = "PIC";
836 		break;
837 	case ACPI_IRQ_MODEL_IOAPIC:
838 		message = "IOAPIC";
839 		break;
840 	case ACPI_IRQ_MODEL_IOSAPIC:
841 		message = "IOSAPIC";
842 		break;
843 	case ACPI_IRQ_MODEL_GIC:
844 		message = "GIC";
845 		break;
846 	case ACPI_IRQ_MODEL_PLATFORM:
847 		message = "platform specific model";
848 		break;
849 	default:
850 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
851 		return -ENODEV;
852 	}
853 
854 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
855 
856 	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
857 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
858 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
859 		return -ENODEV;
860 	}
861 
862 	return 0;
863 }
864 
865 /**
866  * acpi_early_init - Initialize ACPICA and populate the ACPI namespace.
867  *
868  * The ACPI tables are accessible after this, but the handling of events has not
869  * been initialized and the global lock is not available yet, so AML should not
870  * be executed at this point.
871  *
872  * Doing this before switching the EFI runtime services to virtual mode allows
873  * the EfiBootServices memory to be freed slightly earlier on boot.
874  */
875 void __init acpi_early_init(void)
876 {
877 	acpi_status status;
878 
879 	if (acpi_disabled)
880 		return;
881 
882 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
883 
884 	/* It's safe to verify table checksums during late stage */
885 	acpi_gbl_verify_table_checksum = TRUE;
886 
887 	/* enable workarounds, unless strict ACPI spec. compliance */
888 	if (!acpi_strict)
889 		acpi_gbl_enable_interpreter_slack = TRUE;
890 
891 	acpi_gbl_permanent_mmap = 1;
892 
893 	/*
894 	 * If the machine falls into the DMI check table,
895 	 * DSDT will be copied to memory
896 	 */
897 	dmi_check_system(dsdt_dmi_table);
898 
899 	status = acpi_reallocate_root_table();
900 	if (ACPI_FAILURE(status)) {
901 		printk(KERN_ERR PREFIX
902 		       "Unable to reallocate ACPI tables\n");
903 		goto error0;
904 	}
905 
906 	status = acpi_initialize_subsystem();
907 	if (ACPI_FAILURE(status)) {
908 		printk(KERN_ERR PREFIX
909 		       "Unable to initialize the ACPI Interpreter\n");
910 		goto error0;
911 	}
912 
913 	status = acpi_load_tables();
914 	if (ACPI_FAILURE(status)) {
915 		printk(KERN_ERR PREFIX
916 		       "Unable to load the System Description Tables\n");
917 		goto error0;
918 	}
919 
920 #ifdef CONFIG_X86
921 	if (!acpi_ioapic) {
922 		/* compatible (0) means level (3) */
923 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
924 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
925 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
926 		}
927 		/* Set PIC-mode SCI trigger type */
928 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
929 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
930 	} else {
931 		/*
932 		 * now that acpi_gbl_FADT is initialized,
933 		 * update it with result from INT_SRC_OVR parsing
934 		 */
935 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
936 	}
937 #endif
938 	return;
939 
940  error0:
941 	disable_acpi();
942 }
943 
944 /**
945  * acpi_subsystem_init - Finalize the early initialization of ACPI.
946  *
947  * Switch over the platform to the ACPI mode (if possible), initialize the
948  * handling of ACPI events, install the interrupt and global lock handlers.
949  *
950  * Doing this too early is generally unsafe, but at the same time it needs to be
951  * done before all things that really depend on ACPI.  The right spot appears to
952  * be before finalizing the EFI initialization.
953  */
954 void __init acpi_subsystem_init(void)
955 {
956 	acpi_status status;
957 
958 	if (acpi_disabled)
959 		return;
960 
961 	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
962 	if (ACPI_FAILURE(status)) {
963 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
964 		disable_acpi();
965 	} else {
966 		/*
967 		 * If the system is using ACPI then we can be reasonably
968 		 * confident that any regulators are managed by the firmware
969 		 * so tell the regulator core it has everything it needs to
970 		 * know.
971 		 */
972 		regulator_has_full_constraints();
973 	}
974 }
975 
976 static int __init acpi_bus_init(void)
977 {
978 	int result;
979 	acpi_status status;
980 
981 	acpi_os_initialize1();
982 
983 	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
984 	if (ACPI_FAILURE(status)) {
985 		printk(KERN_ERR PREFIX
986 		       "Unable to start the ACPI Interpreter\n");
987 		goto error1;
988 	}
989 
990 	/*
991 	 * ACPI 2.0 requires the EC driver to be loaded and work before
992 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
993 	 * is called).
994 	 *
995 	 * This is accomplished by looking for the ECDT table, and getting
996 	 * the EC parameters out of that.
997 	 */
998 	status = acpi_ec_ecdt_probe();
999 	/* Ignore result. Not having an ECDT is not fatal. */
1000 
1001 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
1002 	if (ACPI_FAILURE(status)) {
1003 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
1004 		goto error1;
1005 	}
1006 
1007 	/*
1008 	 * _OSC method may exist in module level code,
1009 	 * so it must be run after ACPI_FULL_INITIALIZATION
1010 	 */
1011 	acpi_bus_osc_support();
1012 
1013 	/*
1014 	 * _PDC control method may load dynamic SSDT tables,
1015 	 * and we need to install the table handler before that.
1016 	 */
1017 	acpi_sysfs_init();
1018 
1019 	acpi_early_processor_set_pdc();
1020 
1021 	/*
1022 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
1023 	 * is necessary to enable it as early as possible.
1024 	 */
1025 	acpi_boot_ec_enable();
1026 
1027 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
1028 
1029 	/* Initialize sleep structures */
1030 	acpi_sleep_init();
1031 
1032 	/*
1033 	 * Get the system interrupt model and evaluate \_PIC.
1034 	 */
1035 	result = acpi_bus_init_irq();
1036 	if (result)
1037 		goto error1;
1038 
1039 	/*
1040 	 * Register the for all standard device notifications.
1041 	 */
1042 	status =
1043 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
1044 					&acpi_bus_notify, NULL);
1045 	if (ACPI_FAILURE(status)) {
1046 		printk(KERN_ERR PREFIX
1047 		       "Unable to register for device notifications\n");
1048 		goto error1;
1049 	}
1050 
1051 	/*
1052 	 * Create the top ACPI proc directory
1053 	 */
1054 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
1055 
1056 	result = bus_register(&acpi_bus_type);
1057 	if (!result)
1058 		return 0;
1059 
1060 	/* Mimic structured exception handling */
1061       error1:
1062 	acpi_terminate();
1063 	return -ENODEV;
1064 }
1065 
1066 struct kobject *acpi_kobj;
1067 EXPORT_SYMBOL_GPL(acpi_kobj);
1068 
1069 static int __init acpi_init(void)
1070 {
1071 	int result;
1072 
1073 	if (acpi_disabled) {
1074 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
1075 		return -ENODEV;
1076 	}
1077 
1078 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
1079 	if (!acpi_kobj) {
1080 		printk(KERN_WARNING "%s: kset create error\n", __func__);
1081 		acpi_kobj = NULL;
1082 	}
1083 
1084 	init_acpi_device_notify();
1085 	result = acpi_bus_init();
1086 	if (result) {
1087 		disable_acpi();
1088 		return result;
1089 	}
1090 
1091 	pci_mmcfg_late_init();
1092 	acpi_scan_init();
1093 	acpi_ec_init();
1094 	acpi_debugfs_init();
1095 	acpi_sleep_proc_init();
1096 	acpi_wakeup_device_init();
1097 	return 0;
1098 }
1099 
1100 subsys_initcall(acpi_init);
1101