xref: /openbmc/linux/drivers/acpi/bus.c (revision 2e7c04aec86758e0adfcad4a24c86593b45807a3)
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 #include <linux/workqueue.h>
34 #include <linux/reboot.h>
35 #include <linux/delay.h>
36 #ifdef CONFIG_X86
37 #include <asm/mpspec.h>
38 #endif
39 #include <linux/acpi_iort.h>
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 const struct dmi_system_id dsdt_dmi_table[] __initconst = {
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 const struct dmi_system_id dsdt_dmi_table[] __initconst = {
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 EXPORT_SYMBOL_GPL(acpi_bus_get_status_handle);
112 
113 int acpi_bus_get_status(struct acpi_device *device)
114 {
115 	acpi_status status;
116 	unsigned long long sta;
117 
118 	if (acpi_device_always_present(device)) {
119 		acpi_set_device_status(device, ACPI_STA_DEFAULT);
120 		return 0;
121 	}
122 
123 	/* Battery devices must have their deps met before calling _STA */
124 	if (acpi_device_is_battery(device) && device->dep_unmet) {
125 		acpi_set_device_status(device, 0);
126 		return 0;
127 	}
128 
129 	status = acpi_bus_get_status_handle(device->handle, &sta);
130 	if (ACPI_FAILURE(status))
131 		return -ENODEV;
132 
133 	acpi_set_device_status(device, sta);
134 
135 	if (device->status.functional && !device->status.present) {
136 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
137 		       "functional but not present;\n",
138 			device->pnp.bus_id, (u32)sta));
139 	}
140 
141 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
142 			  device->pnp.bus_id, (u32)sta));
143 	return 0;
144 }
145 EXPORT_SYMBOL(acpi_bus_get_status);
146 
147 void acpi_bus_private_data_handler(acpi_handle handle,
148 				   void *context)
149 {
150 	return;
151 }
152 EXPORT_SYMBOL(acpi_bus_private_data_handler);
153 
154 int acpi_bus_attach_private_data(acpi_handle handle, void *data)
155 {
156 	acpi_status status;
157 
158 	status = acpi_attach_data(handle,
159 			acpi_bus_private_data_handler, data);
160 	if (ACPI_FAILURE(status)) {
161 		acpi_handle_debug(handle, "Error attaching device data\n");
162 		return -ENODEV;
163 	}
164 
165 	return 0;
166 }
167 EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);
168 
169 int acpi_bus_get_private_data(acpi_handle handle, void **data)
170 {
171 	acpi_status status;
172 
173 	if (!*data)
174 		return -EINVAL;
175 
176 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
177 	if (ACPI_FAILURE(status)) {
178 		acpi_handle_debug(handle, "No context for object\n");
179 		return -ENODEV;
180 	}
181 
182 	return 0;
183 }
184 EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);
185 
186 void acpi_bus_detach_private_data(acpi_handle handle)
187 {
188 	acpi_detach_data(handle, acpi_bus_private_data_handler);
189 }
190 EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
191 
192 static void acpi_print_osc_error(acpi_handle handle,
193 				 struct acpi_osc_context *context, char *error)
194 {
195 	int i;
196 
197 	acpi_handle_debug(handle, "(%s): %s\n", context->uuid_str, error);
198 
199 	pr_debug("_OSC request data:");
200 	for (i = 0; i < context->cap.length; i += sizeof(u32))
201 		pr_debug(" %x", *((u32 *)(context->cap.pointer + i)));
202 
203 	pr_debug("\n");
204 }
205 
206 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
207 {
208 	acpi_status status;
209 	struct acpi_object_list input;
210 	union acpi_object in_params[4];
211 	union acpi_object *out_obj;
212 	guid_t guid;
213 	u32 errors;
214 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
215 
216 	if (!context)
217 		return AE_ERROR;
218 	if (guid_parse(context->uuid_str, &guid))
219 		return AE_ERROR;
220 	context->ret.length = ACPI_ALLOCATE_BUFFER;
221 	context->ret.pointer = NULL;
222 
223 	/* Setting up input parameters */
224 	input.count = 4;
225 	input.pointer = in_params;
226 	in_params[0].type 		= ACPI_TYPE_BUFFER;
227 	in_params[0].buffer.length 	= 16;
228 	in_params[0].buffer.pointer	= (u8 *)&guid;
229 	in_params[1].type 		= ACPI_TYPE_INTEGER;
230 	in_params[1].integer.value 	= context->rev;
231 	in_params[2].type 		= ACPI_TYPE_INTEGER;
232 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
233 	in_params[3].type		= ACPI_TYPE_BUFFER;
234 	in_params[3].buffer.length 	= context->cap.length;
235 	in_params[3].buffer.pointer 	= context->cap.pointer;
236 
237 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
238 	if (ACPI_FAILURE(status))
239 		return status;
240 
241 	if (!output.length)
242 		return AE_NULL_OBJECT;
243 
244 	out_obj = output.pointer;
245 	if (out_obj->type != ACPI_TYPE_BUFFER
246 		|| out_obj->buffer.length != context->cap.length) {
247 		acpi_print_osc_error(handle, context,
248 			"_OSC evaluation returned wrong type");
249 		status = AE_TYPE;
250 		goto out_kfree;
251 	}
252 	/* Need to ignore the bit0 in result code */
253 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
254 	if (errors) {
255 		if (errors & OSC_REQUEST_ERROR)
256 			acpi_print_osc_error(handle, context,
257 				"_OSC request failed");
258 		if (errors & OSC_INVALID_UUID_ERROR)
259 			acpi_print_osc_error(handle, context,
260 				"_OSC invalid UUID");
261 		if (errors & OSC_INVALID_REVISION_ERROR)
262 			acpi_print_osc_error(handle, context,
263 				"_OSC invalid revision");
264 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
265 			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
266 			    & OSC_QUERY_ENABLE)
267 				goto out_success;
268 			status = AE_SUPPORT;
269 			goto out_kfree;
270 		}
271 		status = AE_ERROR;
272 		goto out_kfree;
273 	}
274 out_success:
275 	context->ret.length = out_obj->buffer.length;
276 	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
277 				       context->ret.length, GFP_KERNEL);
278 	if (!context->ret.pointer) {
279 		status =  AE_NO_MEMORY;
280 		goto out_kfree;
281 	}
282 	status =  AE_OK;
283 
284 out_kfree:
285 	kfree(output.pointer);
286 	if (status != AE_OK)
287 		context->ret.pointer = NULL;
288 	return status;
289 }
290 EXPORT_SYMBOL(acpi_run_osc);
291 
292 bool osc_sb_apei_support_acked;
293 
294 /*
295  * ACPI 6.0 Section 8.4.4.2 Idle State Coordination
296  * OSPM supports platform coordinated low power idle(LPI) states
297  */
298 bool osc_pc_lpi_support_confirmed;
299 EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
300 
301 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
302 static void acpi_bus_osc_support(void)
303 {
304 	u32 capbuf[2];
305 	struct acpi_osc_context context = {
306 		.uuid_str = sb_uuid_str,
307 		.rev = 1,
308 		.cap.length = 8,
309 		.cap.pointer = capbuf,
310 	};
311 	acpi_handle handle;
312 
313 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
314 	capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
315 	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR_AGGREGATOR))
316 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
317 	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR))
318 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
319 
320 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
321 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
322 
323 #ifdef CONFIG_X86
324 	if (boot_cpu_has(X86_FEATURE_HWP)) {
325 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
326 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
327 	}
328 #endif
329 
330 	if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
331 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;
332 
333 	if (!ghes_disable)
334 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
335 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
336 		return;
337 	if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
338 		u32 *capbuf_ret = context.ret.pointer;
339 		if (context.ret.length > OSC_SUPPORT_DWORD) {
340 			osc_sb_apei_support_acked =
341 				capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
342 			osc_pc_lpi_support_confirmed =
343 				capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
344 		}
345 		kfree(context.ret.pointer);
346 	}
347 	/* do we need to check other returned cap? Sounds no */
348 }
349 
350 /* --------------------------------------------------------------------------
351                              Notification Handling
352    -------------------------------------------------------------------------- */
353 
354 /**
355  * acpi_bus_notify
356  * ---------------
357  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
358  */
359 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
360 {
361 	struct acpi_device *adev;
362 	struct acpi_driver *driver;
363 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
364 	bool hotplug_event = false;
365 
366 	switch (type) {
367 	case ACPI_NOTIFY_BUS_CHECK:
368 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
369 		hotplug_event = true;
370 		break;
371 
372 	case ACPI_NOTIFY_DEVICE_CHECK:
373 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
374 		hotplug_event = true;
375 		break;
376 
377 	case ACPI_NOTIFY_DEVICE_WAKE:
378 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
379 		break;
380 
381 	case ACPI_NOTIFY_EJECT_REQUEST:
382 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
383 		hotplug_event = true;
384 		break;
385 
386 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
387 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
388 		/* TBD: Exactly what does 'light' mean? */
389 		break;
390 
391 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
392 		acpi_handle_err(handle, "Device cannot be configured due "
393 				"to a frequency mismatch\n");
394 		break;
395 
396 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
397 		acpi_handle_err(handle, "Device cannot be configured due "
398 				"to a bus mode mismatch\n");
399 		break;
400 
401 	case ACPI_NOTIFY_POWER_FAULT:
402 		acpi_handle_err(handle, "Device has suffered a power fault\n");
403 		break;
404 
405 	default:
406 		acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
407 		break;
408 	}
409 
410 	adev = acpi_bus_get_acpi_device(handle);
411 	if (!adev)
412 		goto err;
413 
414 	driver = adev->driver;
415 	if (driver && driver->ops.notify &&
416 	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
417 		driver->ops.notify(adev, type);
418 
419 	if (!hotplug_event) {
420 		acpi_bus_put_acpi_device(adev);
421 		return;
422 	}
423 
424 	if (ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
425 		return;
426 
427 	acpi_bus_put_acpi_device(adev);
428 
429  err:
430 	acpi_evaluate_ost(handle, type, ost_code, NULL);
431 }
432 
433 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
434 {
435 	struct acpi_device *device = data;
436 
437 	device->driver->ops.notify(device, event);
438 }
439 
440 static void acpi_device_notify_fixed(void *data)
441 {
442 	struct acpi_device *device = data;
443 
444 	/* Fixed hardware devices have no handles */
445 	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
446 }
447 
448 static u32 acpi_device_fixed_event(void *data)
449 {
450 	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
451 	return ACPI_INTERRUPT_HANDLED;
452 }
453 
454 static int acpi_device_install_notify_handler(struct acpi_device *device)
455 {
456 	acpi_status status;
457 
458 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
459 		status =
460 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
461 						     acpi_device_fixed_event,
462 						     device);
463 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
464 		status =
465 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
466 						     acpi_device_fixed_event,
467 						     device);
468 	else
469 		status = acpi_install_notify_handler(device->handle,
470 						     ACPI_DEVICE_NOTIFY,
471 						     acpi_device_notify,
472 						     device);
473 
474 	if (ACPI_FAILURE(status))
475 		return -EINVAL;
476 	return 0;
477 }
478 
479 static void acpi_device_remove_notify_handler(struct acpi_device *device)
480 {
481 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
482 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
483 						acpi_device_fixed_event);
484 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
485 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
486 						acpi_device_fixed_event);
487 	else
488 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
489 					   acpi_device_notify);
490 }
491 
492 /* Handle events targeting \_SB device (at present only graceful shutdown) */
493 
494 #define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
495 #define ACPI_SB_INDICATE_INTERVAL	10000
496 
497 static void sb_notify_work(struct work_struct *dummy)
498 {
499 	acpi_handle sb_handle;
500 
501 	orderly_poweroff(true);
502 
503 	/*
504 	 * After initiating graceful shutdown, the ACPI spec requires OSPM
505 	 * to evaluate _OST method once every 10seconds to indicate that
506 	 * the shutdown is in progress
507 	 */
508 	acpi_get_handle(NULL, "\\_SB", &sb_handle);
509 	while (1) {
510 		pr_info("Graceful shutdown in progress.\n");
511 		acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
512 				ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
513 		msleep(ACPI_SB_INDICATE_INTERVAL);
514 	}
515 }
516 
517 static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
518 {
519 	static DECLARE_WORK(acpi_sb_work, sb_notify_work);
520 
521 	if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
522 		if (!work_busy(&acpi_sb_work))
523 			schedule_work(&acpi_sb_work);
524 	} else
525 		pr_warn("event %x is not supported by \\_SB device\n", event);
526 }
527 
528 static int __init acpi_setup_sb_notify_handler(void)
529 {
530 	acpi_handle sb_handle;
531 
532 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
533 		return -ENXIO;
534 
535 	if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
536 						acpi_sb_notify, NULL)))
537 		return -EINVAL;
538 
539 	return 0;
540 }
541 
542 /* --------------------------------------------------------------------------
543                              Device Matching
544    -------------------------------------------------------------------------- */
545 
546 /**
547  * acpi_get_first_physical_node - Get first physical node of an ACPI device
548  * @adev:	ACPI device in question
549  *
550  * Return: First physical node of ACPI device @adev
551  */
552 struct device *acpi_get_first_physical_node(struct acpi_device *adev)
553 {
554 	struct mutex *physical_node_lock = &adev->physical_node_lock;
555 	struct device *phys_dev;
556 
557 	mutex_lock(physical_node_lock);
558 	if (list_empty(&adev->physical_node_list)) {
559 		phys_dev = NULL;
560 	} else {
561 		const struct acpi_device_physical_node *node;
562 
563 		node = list_first_entry(&adev->physical_node_list,
564 					struct acpi_device_physical_node, node);
565 
566 		phys_dev = node->dev;
567 	}
568 	mutex_unlock(physical_node_lock);
569 	return phys_dev;
570 }
571 
572 static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
573 						      const struct device *dev)
574 {
575 	const struct device *phys_dev = acpi_get_first_physical_node(adev);
576 
577 	return phys_dev && phys_dev == dev ? adev : NULL;
578 }
579 
580 /**
581  * acpi_device_is_first_physical_node - Is given dev first physical node
582  * @adev: ACPI companion device
583  * @dev: Physical device to check
584  *
585  * Function checks if given @dev is the first physical devices attached to
586  * the ACPI companion device. This distinction is needed in some cases
587  * where the same companion device is shared between many physical devices.
588  *
589  * Note that the caller have to provide valid @adev pointer.
590  */
591 bool acpi_device_is_first_physical_node(struct acpi_device *adev,
592 					const struct device *dev)
593 {
594 	return !!acpi_primary_dev_companion(adev, dev);
595 }
596 
597 /*
598  * acpi_companion_match() - Can we match via ACPI companion device
599  * @dev: Device in question
600  *
601  * Check if the given device has an ACPI companion and if that companion has
602  * a valid list of PNP IDs, and if the device is the first (primary) physical
603  * device associated with it.  Return the companion pointer if that's the case
604  * or NULL otherwise.
605  *
606  * If multiple physical devices are attached to a single ACPI companion, we need
607  * to be careful.  The usage scenario for this kind of relationship is that all
608  * of the physical devices in question use resources provided by the ACPI
609  * companion.  A typical case is an MFD device where all the sub-devices share
610  * the parent's ACPI companion.  In such cases we can only allow the primary
611  * (first) physical device to be matched with the help of the companion's PNP
612  * IDs.
613  *
614  * Additional physical devices sharing the ACPI companion can still use
615  * resources available from it but they will be matched normally using functions
616  * provided by their bus types (and analogously for their modalias).
617  */
618 struct acpi_device *acpi_companion_match(const struct device *dev)
619 {
620 	struct acpi_device *adev;
621 
622 	adev = ACPI_COMPANION(dev);
623 	if (!adev)
624 		return NULL;
625 
626 	if (list_empty(&adev->pnp.ids))
627 		return NULL;
628 
629 	return acpi_primary_dev_companion(adev, dev);
630 }
631 
632 /**
633  * acpi_of_match_device - Match device object using the "compatible" property.
634  * @adev: ACPI device object to match.
635  * @of_match_table: List of device IDs to match against.
636  * @of_id: OF ID if matched
637  *
638  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
639  * identifiers and a _DSD object with the "compatible" property, use that
640  * property to match against the given list of identifiers.
641  */
642 static bool acpi_of_match_device(struct acpi_device *adev,
643 				 const struct of_device_id *of_match_table,
644 				 const struct of_device_id **of_id)
645 {
646 	const union acpi_object *of_compatible, *obj;
647 	int i, nval;
648 
649 	if (!adev)
650 		return false;
651 
652 	of_compatible = adev->data.of_compatible;
653 	if (!of_match_table || !of_compatible)
654 		return false;
655 
656 	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
657 		nval = of_compatible->package.count;
658 		obj = of_compatible->package.elements;
659 	} else { /* Must be ACPI_TYPE_STRING. */
660 		nval = 1;
661 		obj = of_compatible;
662 	}
663 	/* Now we can look for the driver DT compatible strings */
664 	for (i = 0; i < nval; i++, obj++) {
665 		const struct of_device_id *id;
666 
667 		for (id = of_match_table; id->compatible[0]; id++)
668 			if (!strcasecmp(obj->string.pointer, id->compatible)) {
669 				if (of_id)
670 					*of_id = id;
671 				return true;
672 			}
673 	}
674 
675 	return false;
676 }
677 
678 static bool acpi_of_modalias(struct acpi_device *adev,
679 			     char *modalias, size_t len)
680 {
681 	const union acpi_object *of_compatible;
682 	const union acpi_object *obj;
683 	const char *str, *chr;
684 
685 	of_compatible = adev->data.of_compatible;
686 	if (!of_compatible)
687 		return false;
688 
689 	if (of_compatible->type == ACPI_TYPE_PACKAGE)
690 		obj = of_compatible->package.elements;
691 	else /* Must be ACPI_TYPE_STRING. */
692 		obj = of_compatible;
693 
694 	str = obj->string.pointer;
695 	chr = strchr(str, ',');
696 	strlcpy(modalias, chr ? chr + 1 : str, len);
697 
698 	return true;
699 }
700 
701 /**
702  * acpi_set_modalias - Set modalias using "compatible" property or supplied ID
703  * @adev:	ACPI device object to match
704  * @default_id:	ID string to use as default if no compatible string found
705  * @modalias:   Pointer to buffer that modalias value will be copied into
706  * @len:	Length of modalias buffer
707  *
708  * This is a counterpart of of_modalias_node() for struct acpi_device objects.
709  * If there is a compatible string for @adev, it will be copied to @modalias
710  * with the vendor prefix stripped; otherwise, @default_id will be used.
711  */
712 void acpi_set_modalias(struct acpi_device *adev, const char *default_id,
713 		       char *modalias, size_t len)
714 {
715 	if (!acpi_of_modalias(adev, modalias, len))
716 		strlcpy(modalias, default_id, len);
717 }
718 EXPORT_SYMBOL_GPL(acpi_set_modalias);
719 
720 static bool __acpi_match_device_cls(const struct acpi_device_id *id,
721 				    struct acpi_hardware_id *hwid)
722 {
723 	int i, msk, byte_shift;
724 	char buf[3];
725 
726 	if (!id->cls)
727 		return false;
728 
729 	/* Apply class-code bitmask, before checking each class-code byte */
730 	for (i = 1; i <= 3; i++) {
731 		byte_shift = 8 * (3 - i);
732 		msk = (id->cls_msk >> byte_shift) & 0xFF;
733 		if (!msk)
734 			continue;
735 
736 		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
737 		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
738 			return false;
739 	}
740 	return true;
741 }
742 
743 static bool __acpi_match_device(struct acpi_device *device,
744 				const struct acpi_device_id *acpi_ids,
745 				const struct of_device_id *of_ids,
746 				const struct acpi_device_id **acpi_id,
747 				const struct of_device_id **of_id)
748 {
749 	const struct acpi_device_id *id;
750 	struct acpi_hardware_id *hwid;
751 
752 	/*
753 	 * If the device is not present, it is unnecessary to load device
754 	 * driver for it.
755 	 */
756 	if (!device || !device->status.present)
757 		return false;
758 
759 	list_for_each_entry(hwid, &device->pnp.ids, list) {
760 		/* First, check the ACPI/PNP IDs provided by the caller. */
761 		if (acpi_ids) {
762 			for (id = acpi_ids; id->id[0] || id->cls; id++) {
763 				if (id->id[0] && !strcmp((char *)id->id, hwid->id))
764 					goto out_acpi_match;
765 				if (id->cls && __acpi_match_device_cls(id, hwid))
766 					goto out_acpi_match;
767 			}
768 		}
769 
770 		/*
771 		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
772 		 * "compatible" property if found.
773 		 */
774 		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id))
775 			return acpi_of_match_device(device, of_ids, of_id);
776 	}
777 	return false;
778 
779 out_acpi_match:
780 	if (acpi_id)
781 		*acpi_id = id;
782 	return true;
783 }
784 
785 /**
786  * acpi_match_device - Match a struct device against a given list of ACPI IDs
787  * @ids: Array of struct acpi_device_id object to match against.
788  * @dev: The device structure to match.
789  *
790  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
791  * object for that handle and use that object to match against a given list of
792  * device IDs.
793  *
794  * Return a pointer to the first matching ID on success or %NULL on failure.
795  */
796 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
797 					       const struct device *dev)
798 {
799 	const struct acpi_device_id *id = NULL;
800 
801 	__acpi_match_device(acpi_companion_match(dev), ids, NULL, &id, NULL);
802 	return id;
803 }
804 EXPORT_SYMBOL_GPL(acpi_match_device);
805 
806 const void *acpi_device_get_match_data(const struct device *dev)
807 {
808 	const struct acpi_device_id *match;
809 
810 	match = acpi_match_device(dev->driver->acpi_match_table, dev);
811 	if (!match)
812 		return NULL;
813 
814 	return (const void *)match->driver_data;
815 }
816 EXPORT_SYMBOL_GPL(acpi_device_get_match_data);
817 
818 int acpi_match_device_ids(struct acpi_device *device,
819 			  const struct acpi_device_id *ids)
820 {
821 	return __acpi_match_device(device, ids, NULL, NULL, NULL) ? 0 : -ENOENT;
822 }
823 EXPORT_SYMBOL(acpi_match_device_ids);
824 
825 bool acpi_driver_match_device(struct device *dev,
826 			      const struct device_driver *drv)
827 {
828 	if (!drv->acpi_match_table)
829 		return acpi_of_match_device(ACPI_COMPANION(dev),
830 					    drv->of_match_table,
831 					    NULL);
832 
833 	return __acpi_match_device(acpi_companion_match(dev),
834 				   drv->acpi_match_table, drv->of_match_table,
835 				   NULL, NULL);
836 }
837 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
838 
839 /* --------------------------------------------------------------------------
840                               ACPI Driver Management
841    -------------------------------------------------------------------------- */
842 
843 /**
844  * acpi_bus_register_driver - register a driver with the ACPI bus
845  * @driver: driver being registered
846  *
847  * Registers a driver with the ACPI bus.  Searches the namespace for all
848  * devices that match the driver's criteria and binds.  Returns zero for
849  * success or a negative error status for failure.
850  */
851 int acpi_bus_register_driver(struct acpi_driver *driver)
852 {
853 	int ret;
854 
855 	if (acpi_disabled)
856 		return -ENODEV;
857 	driver->drv.name = driver->name;
858 	driver->drv.bus = &acpi_bus_type;
859 	driver->drv.owner = driver->owner;
860 
861 	ret = driver_register(&driver->drv);
862 	return ret;
863 }
864 
865 EXPORT_SYMBOL(acpi_bus_register_driver);
866 
867 /**
868  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
869  * @driver: driver to unregister
870  *
871  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
872  * devices that match the driver's criteria and unbinds.
873  */
874 void acpi_bus_unregister_driver(struct acpi_driver *driver)
875 {
876 	driver_unregister(&driver->drv);
877 }
878 
879 EXPORT_SYMBOL(acpi_bus_unregister_driver);
880 
881 /* --------------------------------------------------------------------------
882                               ACPI Bus operations
883    -------------------------------------------------------------------------- */
884 
885 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
886 {
887 	struct acpi_device *acpi_dev = to_acpi_device(dev);
888 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
889 
890 	return acpi_dev->flags.match_driver
891 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
892 }
893 
894 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
895 {
896 	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
897 }
898 
899 static int acpi_device_probe(struct device *dev)
900 {
901 	struct acpi_device *acpi_dev = to_acpi_device(dev);
902 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
903 	int ret;
904 
905 	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
906 		return -EINVAL;
907 
908 	if (!acpi_drv->ops.add)
909 		return -ENOSYS;
910 
911 	ret = acpi_drv->ops.add(acpi_dev);
912 	if (ret)
913 		return ret;
914 
915 	acpi_dev->driver = acpi_drv;
916 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
917 			  "Driver [%s] successfully bound to device [%s]\n",
918 			  acpi_drv->name, acpi_dev->pnp.bus_id));
919 
920 	if (acpi_drv->ops.notify) {
921 		ret = acpi_device_install_notify_handler(acpi_dev);
922 		if (ret) {
923 			if (acpi_drv->ops.remove)
924 				acpi_drv->ops.remove(acpi_dev);
925 
926 			acpi_dev->driver = NULL;
927 			acpi_dev->driver_data = NULL;
928 			return ret;
929 		}
930 	}
931 
932 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
933 			  acpi_drv->name, acpi_dev->pnp.bus_id));
934 	get_device(dev);
935 	return 0;
936 }
937 
938 static int acpi_device_remove(struct device *dev)
939 {
940 	struct acpi_device *acpi_dev = to_acpi_device(dev);
941 	struct acpi_driver *acpi_drv = acpi_dev->driver;
942 
943 	if (acpi_drv) {
944 		if (acpi_drv->ops.notify)
945 			acpi_device_remove_notify_handler(acpi_dev);
946 		if (acpi_drv->ops.remove)
947 			acpi_drv->ops.remove(acpi_dev);
948 	}
949 	acpi_dev->driver = NULL;
950 	acpi_dev->driver_data = NULL;
951 
952 	put_device(dev);
953 	return 0;
954 }
955 
956 struct bus_type acpi_bus_type = {
957 	.name		= "acpi",
958 	.match		= acpi_bus_match,
959 	.probe		= acpi_device_probe,
960 	.remove		= acpi_device_remove,
961 	.uevent		= acpi_device_uevent,
962 };
963 
964 /* --------------------------------------------------------------------------
965                              Initialization/Cleanup
966    -------------------------------------------------------------------------- */
967 
968 static int __init acpi_bus_init_irq(void)
969 {
970 	acpi_status status;
971 	char *message = NULL;
972 
973 
974 	/*
975 	 * Let the system know what interrupt model we are using by
976 	 * evaluating the \_PIC object, if exists.
977 	 */
978 
979 	switch (acpi_irq_model) {
980 	case ACPI_IRQ_MODEL_PIC:
981 		message = "PIC";
982 		break;
983 	case ACPI_IRQ_MODEL_IOAPIC:
984 		message = "IOAPIC";
985 		break;
986 	case ACPI_IRQ_MODEL_IOSAPIC:
987 		message = "IOSAPIC";
988 		break;
989 	case ACPI_IRQ_MODEL_GIC:
990 		message = "GIC";
991 		break;
992 	case ACPI_IRQ_MODEL_PLATFORM:
993 		message = "platform specific model";
994 		break;
995 	default:
996 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
997 		return -ENODEV;
998 	}
999 
1000 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
1001 
1002 	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
1003 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
1004 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
1005 		return -ENODEV;
1006 	}
1007 
1008 	return 0;
1009 }
1010 
1011 /**
1012  * acpi_early_init - Initialize ACPICA and populate the ACPI namespace.
1013  *
1014  * The ACPI tables are accessible after this, but the handling of events has not
1015  * been initialized and the global lock is not available yet, so AML should not
1016  * be executed at this point.
1017  *
1018  * Doing this before switching the EFI runtime services to virtual mode allows
1019  * the EfiBootServices memory to be freed slightly earlier on boot.
1020  */
1021 void __init acpi_early_init(void)
1022 {
1023 	acpi_status status;
1024 
1025 	if (acpi_disabled)
1026 		return;
1027 
1028 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
1029 
1030 	/* enable workarounds, unless strict ACPI spec. compliance */
1031 	if (!acpi_strict)
1032 		acpi_gbl_enable_interpreter_slack = TRUE;
1033 
1034 	acpi_permanent_mmap = true;
1035 
1036 	/*
1037 	 * If the machine falls into the DMI check table,
1038 	 * DSDT will be copied to memory
1039 	 */
1040 	dmi_check_system(dsdt_dmi_table);
1041 
1042 	status = acpi_reallocate_root_table();
1043 	if (ACPI_FAILURE(status)) {
1044 		printk(KERN_ERR PREFIX
1045 		       "Unable to reallocate ACPI tables\n");
1046 		goto error0;
1047 	}
1048 
1049 	status = acpi_initialize_subsystem();
1050 	if (ACPI_FAILURE(status)) {
1051 		printk(KERN_ERR PREFIX
1052 		       "Unable to initialize the ACPI Interpreter\n");
1053 		goto error0;
1054 	}
1055 
1056 	if (!acpi_gbl_execute_tables_as_methods &&
1057 	    acpi_gbl_group_module_level_code) {
1058 		status = acpi_load_tables();
1059 		if (ACPI_FAILURE(status)) {
1060 			printk(KERN_ERR PREFIX
1061 			       "Unable to load the System Description Tables\n");
1062 			goto error0;
1063 		}
1064 	}
1065 
1066 #ifdef CONFIG_X86
1067 	if (!acpi_ioapic) {
1068 		/* compatible (0) means level (3) */
1069 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
1070 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
1071 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
1072 		}
1073 		/* Set PIC-mode SCI trigger type */
1074 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
1075 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
1076 	} else {
1077 		/*
1078 		 * now that acpi_gbl_FADT is initialized,
1079 		 * update it with result from INT_SRC_OVR parsing
1080 		 */
1081 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
1082 	}
1083 #endif
1084 	return;
1085 
1086  error0:
1087 	disable_acpi();
1088 }
1089 
1090 /**
1091  * acpi_subsystem_init - Finalize the early initialization of ACPI.
1092  *
1093  * Switch over the platform to the ACPI mode (if possible).
1094  *
1095  * Doing this too early is generally unsafe, but at the same time it needs to be
1096  * done before all things that really depend on ACPI.  The right spot appears to
1097  * be before finalizing the EFI initialization.
1098  */
1099 void __init acpi_subsystem_init(void)
1100 {
1101 	acpi_status status;
1102 
1103 	if (acpi_disabled)
1104 		return;
1105 
1106 	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
1107 	if (ACPI_FAILURE(status)) {
1108 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
1109 		disable_acpi();
1110 	} else {
1111 		/*
1112 		 * If the system is using ACPI then we can be reasonably
1113 		 * confident that any regulators are managed by the firmware
1114 		 * so tell the regulator core it has everything it needs to
1115 		 * know.
1116 		 */
1117 		regulator_has_full_constraints();
1118 	}
1119 }
1120 
1121 static acpi_status acpi_bus_table_handler(u32 event, void *table, void *context)
1122 {
1123 	acpi_scan_table_handler(event, table, context);
1124 
1125 	return acpi_sysfs_table_handler(event, table, context);
1126 }
1127 
1128 static int __init acpi_bus_init(void)
1129 {
1130 	int result;
1131 	acpi_status status;
1132 
1133 	acpi_os_initialize1();
1134 
1135 	/*
1136 	 * ACPI 2.0 requires the EC driver to be loaded and work before
1137 	 * the EC device is found in the namespace (i.e. before
1138 	 * acpi_load_tables() is called).
1139 	 *
1140 	 * This is accomplished by looking for the ECDT table, and getting
1141 	 * the EC parameters out of that.
1142 	 */
1143 	status = acpi_ec_ecdt_probe();
1144 	/* Ignore result. Not having an ECDT is not fatal. */
1145 
1146 	if (acpi_gbl_execute_tables_as_methods ||
1147 	    !acpi_gbl_group_module_level_code) {
1148 		status = acpi_load_tables();
1149 		if (ACPI_FAILURE(status)) {
1150 			printk(KERN_ERR PREFIX
1151 			       "Unable to load the System Description Tables\n");
1152 			goto error1;
1153 		}
1154 	}
1155 
1156 	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
1157 	if (ACPI_FAILURE(status)) {
1158 		printk(KERN_ERR PREFIX
1159 		       "Unable to start the ACPI Interpreter\n");
1160 		goto error1;
1161 	}
1162 
1163 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
1164 	if (ACPI_FAILURE(status)) {
1165 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
1166 		goto error1;
1167 	}
1168 
1169 	/* Set capability bits for _OSC under processor scope */
1170 	acpi_early_processor_osc();
1171 
1172 	/*
1173 	 * _OSC method may exist in module level code,
1174 	 * so it must be run after ACPI_FULL_INITIALIZATION
1175 	 */
1176 	acpi_bus_osc_support();
1177 
1178 	/*
1179 	 * _PDC control method may load dynamic SSDT tables,
1180 	 * and we need to install the table handler before that.
1181 	 */
1182 	status = acpi_install_table_handler(acpi_bus_table_handler, NULL);
1183 
1184 	acpi_sysfs_init();
1185 
1186 	acpi_early_processor_set_pdc();
1187 
1188 	/*
1189 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
1190 	 * is necessary to enable it as early as possible.
1191 	 */
1192 	acpi_ec_dsdt_probe();
1193 
1194 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
1195 
1196 	/* Initialize sleep structures */
1197 	acpi_sleep_init();
1198 
1199 	/*
1200 	 * Get the system interrupt model and evaluate \_PIC.
1201 	 */
1202 	result = acpi_bus_init_irq();
1203 	if (result)
1204 		goto error1;
1205 
1206 	/*
1207 	 * Register the for all standard device notifications.
1208 	 */
1209 	status =
1210 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
1211 					&acpi_bus_notify, NULL);
1212 	if (ACPI_FAILURE(status)) {
1213 		printk(KERN_ERR PREFIX
1214 		       "Unable to register for device notifications\n");
1215 		goto error1;
1216 	}
1217 
1218 	/*
1219 	 * Create the top ACPI proc directory
1220 	 */
1221 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
1222 
1223 	result = bus_register(&acpi_bus_type);
1224 	if (!result)
1225 		return 0;
1226 
1227 	/* Mimic structured exception handling */
1228       error1:
1229 	acpi_terminate();
1230 	return -ENODEV;
1231 }
1232 
1233 struct kobject *acpi_kobj;
1234 EXPORT_SYMBOL_GPL(acpi_kobj);
1235 
1236 static int __init acpi_init(void)
1237 {
1238 	int result;
1239 
1240 	if (acpi_disabled) {
1241 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
1242 		return -ENODEV;
1243 	}
1244 
1245 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
1246 	if (!acpi_kobj) {
1247 		printk(KERN_WARNING "%s: kset create error\n", __func__);
1248 		acpi_kobj = NULL;
1249 	}
1250 
1251 	init_acpi_device_notify();
1252 	result = acpi_bus_init();
1253 	if (result) {
1254 		disable_acpi();
1255 		return result;
1256 	}
1257 
1258 	pci_mmcfg_late_init();
1259 	acpi_iort_init();
1260 	acpi_scan_init();
1261 	acpi_ec_init();
1262 	acpi_debugfs_init();
1263 	acpi_sleep_proc_init();
1264 	acpi_wakeup_device_init();
1265 	acpi_debugger_init();
1266 	acpi_setup_sb_notify_handler();
1267 	return 0;
1268 }
1269 
1270 subsys_initcall(acpi_init);
1271