xref: /linux/drivers/acpi/bus.c (revision c48a7c44a1d02516309015b6134c9bb982e17008)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
4  *
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  */
7 
8 #define pr_fmt(fmt) "ACPI: " fmt
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/ioport.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/sched.h>
16 #include <linux/pm.h>
17 #include <linux/device.h>
18 #include <linux/proc_fs.h>
19 #include <linux/acpi.h>
20 #include <linux/slab.h>
21 #include <linux/regulator/machine.h>
22 #include <linux/workqueue.h>
23 #include <linux/reboot.h>
24 #include <linux/delay.h>
25 #ifdef CONFIG_X86
26 #include <asm/mpspec.h>
27 #include <linux/dmi.h>
28 #endif
29 #include <linux/acpi_viot.h>
30 #include <linux/pci.h>
31 #include <acpi/apei.h>
32 #include <linux/suspend.h>
33 #include <linux/prmt.h>
34 
35 #include "internal.h"
36 
37 struct acpi_device *acpi_root;
38 struct proc_dir_entry *acpi_root_dir;
39 EXPORT_SYMBOL(acpi_root_dir);
40 
41 #ifdef CONFIG_X86
42 #ifdef CONFIG_ACPI_CUSTOM_DSDT
43 static inline int set_copy_dsdt(const struct dmi_system_id *id)
44 {
45 	return 0;
46 }
47 #else
48 static int set_copy_dsdt(const struct dmi_system_id *id)
49 {
50 	pr_notice("%s detected - force copy of DSDT to local memory\n", id->ident);
51 	acpi_gbl_copy_dsdt_locally = 1;
52 	return 0;
53 }
54 #endif
55 
56 static const struct dmi_system_id dsdt_dmi_table[] __initconst = {
57 	/*
58 	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
59 	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
60 	 */
61 	{
62 	 .callback = set_copy_dsdt,
63 	 .ident = "TOSHIBA Satellite",
64 	 .matches = {
65 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
66 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
67 		},
68 	},
69 	{}
70 };
71 #endif
72 
73 /* --------------------------------------------------------------------------
74                                 Device Management
75    -------------------------------------------------------------------------- */
76 
77 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
78 				       unsigned long long *sta)
79 {
80 	acpi_status status;
81 
82 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
83 	if (ACPI_SUCCESS(status))
84 		return AE_OK;
85 
86 	if (status == AE_NOT_FOUND) {
87 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
88 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
89 		return AE_OK;
90 	}
91 	return status;
92 }
93 EXPORT_SYMBOL_GPL(acpi_bus_get_status_handle);
94 
95 int acpi_bus_get_status(struct acpi_device *device)
96 {
97 	acpi_status status;
98 	unsigned long long sta;
99 
100 	if (acpi_device_override_status(device, &sta)) {
101 		acpi_set_device_status(device, sta);
102 		return 0;
103 	}
104 
105 	/* Battery devices must have their deps met before calling _STA */
106 	if (acpi_device_is_battery(device) && device->dep_unmet) {
107 		acpi_set_device_status(device, 0);
108 		return 0;
109 	}
110 
111 	status = acpi_bus_get_status_handle(device->handle, &sta);
112 	if (ACPI_FAILURE(status))
113 		return -ENODEV;
114 
115 	acpi_set_device_status(device, sta);
116 
117 	if (device->status.functional && !device->status.present) {
118 		pr_debug("Device [%s] status [%08x]: functional but not present\n",
119 			 device->pnp.bus_id, (u32)sta);
120 	}
121 
122 	pr_debug("Device [%s] status [%08x]\n", device->pnp.bus_id, (u32)sta);
123 	return 0;
124 }
125 EXPORT_SYMBOL(acpi_bus_get_status);
126 
127 void acpi_bus_private_data_handler(acpi_handle handle,
128 				   void *context)
129 {
130 	return;
131 }
132 EXPORT_SYMBOL(acpi_bus_private_data_handler);
133 
134 int acpi_bus_attach_private_data(acpi_handle handle, void *data)
135 {
136 	acpi_status status;
137 
138 	status = acpi_attach_data(handle,
139 			acpi_bus_private_data_handler, data);
140 	if (ACPI_FAILURE(status)) {
141 		acpi_handle_debug(handle, "Error attaching device data\n");
142 		return -ENODEV;
143 	}
144 
145 	return 0;
146 }
147 EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);
148 
149 int acpi_bus_get_private_data(acpi_handle handle, void **data)
150 {
151 	acpi_status status;
152 
153 	if (!data)
154 		return -EINVAL;
155 
156 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
157 	if (ACPI_FAILURE(status)) {
158 		acpi_handle_debug(handle, "No context for object\n");
159 		return -ENODEV;
160 	}
161 
162 	return 0;
163 }
164 EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);
165 
166 void acpi_bus_detach_private_data(acpi_handle handle)
167 {
168 	acpi_detach_data(handle, acpi_bus_private_data_handler);
169 }
170 EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
171 
172 static void acpi_print_osc_error(acpi_handle handle,
173 				 struct acpi_osc_context *context, char *error)
174 {
175 	int i;
176 
177 	acpi_handle_debug(handle, "(%s): %s\n", context->uuid_str, error);
178 
179 	pr_debug("_OSC request data:");
180 	for (i = 0; i < context->cap.length; i += sizeof(u32))
181 		pr_debug(" %x", *((u32 *)(context->cap.pointer + i)));
182 
183 	pr_debug("\n");
184 }
185 
186 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
187 {
188 	acpi_status status;
189 	struct acpi_object_list input;
190 	union acpi_object in_params[4];
191 	union acpi_object *out_obj;
192 	guid_t guid;
193 	u32 errors;
194 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
195 
196 	if (!context)
197 		return AE_ERROR;
198 	if (guid_parse(context->uuid_str, &guid))
199 		return AE_ERROR;
200 	context->ret.length = ACPI_ALLOCATE_BUFFER;
201 	context->ret.pointer = NULL;
202 
203 	/* Setting up input parameters */
204 	input.count = 4;
205 	input.pointer = in_params;
206 	in_params[0].type 		= ACPI_TYPE_BUFFER;
207 	in_params[0].buffer.length 	= 16;
208 	in_params[0].buffer.pointer	= (u8 *)&guid;
209 	in_params[1].type 		= ACPI_TYPE_INTEGER;
210 	in_params[1].integer.value 	= context->rev;
211 	in_params[2].type 		= ACPI_TYPE_INTEGER;
212 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
213 	in_params[3].type		= ACPI_TYPE_BUFFER;
214 	in_params[3].buffer.length 	= context->cap.length;
215 	in_params[3].buffer.pointer 	= context->cap.pointer;
216 
217 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
218 	if (ACPI_FAILURE(status))
219 		return status;
220 
221 	if (!output.length)
222 		return AE_NULL_OBJECT;
223 
224 	out_obj = output.pointer;
225 	if (out_obj->type != ACPI_TYPE_BUFFER
226 		|| out_obj->buffer.length != context->cap.length) {
227 		acpi_print_osc_error(handle, context,
228 			"_OSC evaluation returned wrong type");
229 		status = AE_TYPE;
230 		goto out_kfree;
231 	}
232 	/* Need to ignore the bit0 in result code */
233 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
234 	if (errors) {
235 		if (errors & OSC_REQUEST_ERROR)
236 			acpi_print_osc_error(handle, context,
237 				"_OSC request failed");
238 		if (errors & OSC_INVALID_UUID_ERROR)
239 			acpi_print_osc_error(handle, context,
240 				"_OSC invalid UUID");
241 		if (errors & OSC_INVALID_REVISION_ERROR)
242 			acpi_print_osc_error(handle, context,
243 				"_OSC invalid revision");
244 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
245 			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
246 			    & OSC_QUERY_ENABLE)
247 				goto out_success;
248 			status = AE_SUPPORT;
249 			goto out_kfree;
250 		}
251 		status = AE_ERROR;
252 		goto out_kfree;
253 	}
254 out_success:
255 	context->ret.length = out_obj->buffer.length;
256 	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
257 				       context->ret.length, GFP_KERNEL);
258 	if (!context->ret.pointer) {
259 		status =  AE_NO_MEMORY;
260 		goto out_kfree;
261 	}
262 	status =  AE_OK;
263 
264 out_kfree:
265 	kfree(output.pointer);
266 	return status;
267 }
268 EXPORT_SYMBOL(acpi_run_osc);
269 
270 bool osc_sb_apei_support_acked;
271 
272 /*
273  * ACPI 6.0 Section 8.4.4.2 Idle State Coordination
274  * OSPM supports platform coordinated low power idle(LPI) states
275  */
276 bool osc_pc_lpi_support_confirmed;
277 EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
278 
279 /*
280  * ACPI 6.2 Section 6.2.11.2 'Platform-Wide OSPM Capabilities':
281  *   Starting with ACPI Specification 6.2, all _CPC registers can be in
282  *   PCC, System Memory, System IO, or Functional Fixed Hardware address
283  *   spaces. OSPM support for this more flexible register space scheme is
284  *   indicated by the “Flexible Address Space for CPPC Registers” _OSC bit.
285  *
286  * Otherwise (cf ACPI 6.1, s8.4.7.1.1.X), _CPC registers must be in:
287  * - PCC or Functional Fixed Hardware address space if defined
288  * - SystemMemory address space (NULL register) if not defined
289  */
290 bool osc_cpc_flexible_adr_space_confirmed;
291 EXPORT_SYMBOL_GPL(osc_cpc_flexible_adr_space_confirmed);
292 
293 /*
294  * ACPI 6.4 Operating System Capabilities for USB.
295  */
296 bool osc_sb_native_usb4_support_confirmed;
297 EXPORT_SYMBOL_GPL(osc_sb_native_usb4_support_confirmed);
298 
299 bool osc_sb_cppc2_support_acked;
300 
301 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
302 static void acpi_bus_osc_negotiate_platform_control(void)
303 {
304 	u32 capbuf[2], *capbuf_ret;
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 	if (IS_ENABLED(CONFIG_ACPI_PRMT))
323 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PRM_SUPPORT;
324 	if (IS_ENABLED(CONFIG_ACPI_FFH))
325 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_FFH_OPR_SUPPORT;
326 
327 #ifdef CONFIG_ARM64
328 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
329 #endif
330 #ifdef CONFIG_X86
331 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
332 #endif
333 
334 #ifdef CONFIG_ACPI_CPPC_LIB
335 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
336 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
337 #endif
338 
339 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_FLEXIBLE_ADR_SPACE;
340 
341 	if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
342 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;
343 
344 	if (IS_ENABLED(CONFIG_USB4))
345 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_NATIVE_USB4_SUPPORT;
346 
347 	if (!ghes_disable)
348 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
349 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
350 		return;
351 
352 	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
353 		return;
354 
355 	capbuf_ret = context.ret.pointer;
356 	if (context.ret.length <= OSC_SUPPORT_DWORD) {
357 		kfree(context.ret.pointer);
358 		return;
359 	}
360 
361 	/*
362 	 * Now run _OSC again with query flag clear and with the caps
363 	 * supported by both the OS and the platform.
364 	 */
365 	capbuf[OSC_QUERY_DWORD] = 0;
366 	capbuf[OSC_SUPPORT_DWORD] = capbuf_ret[OSC_SUPPORT_DWORD];
367 	kfree(context.ret.pointer);
368 
369 	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
370 		return;
371 
372 	capbuf_ret = context.ret.pointer;
373 	if (context.ret.length > OSC_SUPPORT_DWORD) {
374 #ifdef CONFIG_ACPI_CPPC_LIB
375 		osc_sb_cppc2_support_acked = capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_CPCV2_SUPPORT;
376 #endif
377 
378 		osc_sb_apei_support_acked =
379 			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
380 		osc_pc_lpi_support_confirmed =
381 			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
382 		osc_sb_native_usb4_support_confirmed =
383 			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
384 		osc_cpc_flexible_adr_space_confirmed =
385 			capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_CPC_FLEXIBLE_ADR_SPACE;
386 	}
387 
388 	kfree(context.ret.pointer);
389 }
390 
391 /*
392  * Native control of USB4 capabilities. If any of the tunneling bits is
393  * set it means OS is in control and we use software based connection
394  * manager.
395  */
396 u32 osc_sb_native_usb4_control;
397 EXPORT_SYMBOL_GPL(osc_sb_native_usb4_control);
398 
399 static void acpi_bus_decode_usb_osc(const char *msg, u32 bits)
400 {
401 	pr_info("%s USB3%c DisplayPort%c PCIe%c XDomain%c\n", msg,
402 	       (bits & OSC_USB_USB3_TUNNELING) ? '+' : '-',
403 	       (bits & OSC_USB_DP_TUNNELING) ? '+' : '-',
404 	       (bits & OSC_USB_PCIE_TUNNELING) ? '+' : '-',
405 	       (bits & OSC_USB_XDOMAIN) ? '+' : '-');
406 }
407 
408 static u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
409 static void acpi_bus_osc_negotiate_usb_control(void)
410 {
411 	u32 capbuf[3];
412 	struct acpi_osc_context context = {
413 		.uuid_str = sb_usb_uuid_str,
414 		.rev = 1,
415 		.cap.length = sizeof(capbuf),
416 		.cap.pointer = capbuf,
417 	};
418 	acpi_handle handle;
419 	acpi_status status;
420 	u32 control;
421 
422 	if (!osc_sb_native_usb4_support_confirmed)
423 		return;
424 
425 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
426 		return;
427 
428 	control = OSC_USB_USB3_TUNNELING | OSC_USB_DP_TUNNELING |
429 		  OSC_USB_PCIE_TUNNELING | OSC_USB_XDOMAIN;
430 
431 	capbuf[OSC_QUERY_DWORD] = 0;
432 	capbuf[OSC_SUPPORT_DWORD] = 0;
433 	capbuf[OSC_CONTROL_DWORD] = control;
434 
435 	status = acpi_run_osc(handle, &context);
436 	if (ACPI_FAILURE(status))
437 		return;
438 
439 	if (context.ret.length != sizeof(capbuf)) {
440 		pr_info("USB4 _OSC: returned invalid length buffer\n");
441 		goto out_free;
442 	}
443 
444 	osc_sb_native_usb4_control =
445 		control &  acpi_osc_ctx_get_pci_control(&context);
446 
447 	acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
448 	acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",
449 				osc_sb_native_usb4_control);
450 
451 out_free:
452 	kfree(context.ret.pointer);
453 }
454 
455 /* --------------------------------------------------------------------------
456                              Notification Handling
457    -------------------------------------------------------------------------- */
458 
459 /**
460  * acpi_bus_notify - Global system-level (0x00-0x7F) notifications handler
461  * @handle: Target ACPI object.
462  * @type: Notification type.
463  * @data: Ignored.
464  *
465  * This only handles notifications related to device hotplug.
466  */
467 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
468 {
469 	struct acpi_device *adev;
470 
471 	switch (type) {
472 	case ACPI_NOTIFY_BUS_CHECK:
473 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
474 		break;
475 
476 	case ACPI_NOTIFY_DEVICE_CHECK:
477 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
478 		break;
479 
480 	case ACPI_NOTIFY_DEVICE_WAKE:
481 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
482 		return;
483 
484 	case ACPI_NOTIFY_EJECT_REQUEST:
485 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
486 		break;
487 
488 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
489 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
490 		/* TBD: Exactly what does 'light' mean? */
491 		return;
492 
493 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
494 		acpi_handle_err(handle, "Device cannot be configured due "
495 				"to a frequency mismatch\n");
496 		return;
497 
498 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
499 		acpi_handle_err(handle, "Device cannot be configured due "
500 				"to a bus mode mismatch\n");
501 		return;
502 
503 	case ACPI_NOTIFY_POWER_FAULT:
504 		acpi_handle_err(handle, "Device has suffered a power fault\n");
505 		return;
506 
507 	default:
508 		acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
509 		return;
510 	}
511 
512 	adev = acpi_get_acpi_dev(handle);
513 
514 	if (adev && ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
515 		return;
516 
517 	acpi_put_acpi_dev(adev);
518 
519 	acpi_evaluate_ost(handle, type, ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
520 }
521 
522 static void acpi_notify_device(acpi_handle handle, u32 event, void *data)
523 {
524 	struct acpi_device *device = data;
525 	struct acpi_driver *acpi_drv = to_acpi_driver(device->dev.driver);
526 
527 	acpi_drv->ops.notify(device, event);
528 }
529 
530 static int acpi_device_install_notify_handler(struct acpi_device *device,
531 					      struct acpi_driver *acpi_drv)
532 {
533 	u32 type = acpi_drv->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS ?
534 				ACPI_ALL_NOTIFY : ACPI_DEVICE_NOTIFY;
535 	acpi_status status;
536 
537 	status = acpi_install_notify_handler(device->handle, type,
538 					     acpi_notify_device, device);
539 	if (ACPI_FAILURE(status))
540 		return -EINVAL;
541 
542 	return 0;
543 }
544 
545 static void acpi_device_remove_notify_handler(struct acpi_device *device,
546 					      struct acpi_driver *acpi_drv)
547 {
548 	u32 type = acpi_drv->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS ?
549 				ACPI_ALL_NOTIFY : ACPI_DEVICE_NOTIFY;
550 
551 	acpi_remove_notify_handler(device->handle, type,
552 				   acpi_notify_device);
553 
554 	acpi_os_wait_events_complete();
555 }
556 
557 int acpi_dev_install_notify_handler(struct acpi_device *adev,
558 				    u32 handler_type,
559 				    acpi_notify_handler handler, void *context)
560 {
561 	acpi_status status;
562 
563 	status = acpi_install_notify_handler(adev->handle, handler_type,
564 					     handler, context);
565 	if (ACPI_FAILURE(status))
566 		return -ENODEV;
567 
568 	return 0;
569 }
570 EXPORT_SYMBOL_GPL(acpi_dev_install_notify_handler);
571 
572 void acpi_dev_remove_notify_handler(struct acpi_device *adev,
573 				    u32 handler_type,
574 				    acpi_notify_handler handler)
575 {
576 	acpi_remove_notify_handler(adev->handle, handler_type, handler);
577 	acpi_os_wait_events_complete();
578 }
579 EXPORT_SYMBOL_GPL(acpi_dev_remove_notify_handler);
580 
581 /* Handle events targeting \_SB device (at present only graceful shutdown) */
582 
583 #define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
584 #define ACPI_SB_INDICATE_INTERVAL	10000
585 
586 static void sb_notify_work(struct work_struct *dummy)
587 {
588 	acpi_handle sb_handle;
589 
590 	orderly_poweroff(true);
591 
592 	/*
593 	 * After initiating graceful shutdown, the ACPI spec requires OSPM
594 	 * to evaluate _OST method once every 10seconds to indicate that
595 	 * the shutdown is in progress
596 	 */
597 	acpi_get_handle(NULL, "\\_SB", &sb_handle);
598 	while (1) {
599 		pr_info("Graceful shutdown in progress.\n");
600 		acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
601 				ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
602 		msleep(ACPI_SB_INDICATE_INTERVAL);
603 	}
604 }
605 
606 static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
607 {
608 	static DECLARE_WORK(acpi_sb_work, sb_notify_work);
609 
610 	if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
611 		if (!work_busy(&acpi_sb_work))
612 			schedule_work(&acpi_sb_work);
613 	} else {
614 		pr_warn("event %x is not supported by \\_SB device\n", event);
615 	}
616 }
617 
618 static int __init acpi_setup_sb_notify_handler(void)
619 {
620 	acpi_handle sb_handle;
621 
622 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
623 		return -ENXIO;
624 
625 	if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
626 						acpi_sb_notify, NULL)))
627 		return -EINVAL;
628 
629 	return 0;
630 }
631 
632 /* --------------------------------------------------------------------------
633                              Device Matching
634    -------------------------------------------------------------------------- */
635 
636 /**
637  * acpi_get_first_physical_node - Get first physical node of an ACPI device
638  * @adev:	ACPI device in question
639  *
640  * Return: First physical node of ACPI device @adev
641  */
642 struct device *acpi_get_first_physical_node(struct acpi_device *adev)
643 {
644 	struct mutex *physical_node_lock = &adev->physical_node_lock;
645 	struct device *phys_dev;
646 
647 	mutex_lock(physical_node_lock);
648 	if (list_empty(&adev->physical_node_list)) {
649 		phys_dev = NULL;
650 	} else {
651 		const struct acpi_device_physical_node *node;
652 
653 		node = list_first_entry(&adev->physical_node_list,
654 					struct acpi_device_physical_node, node);
655 
656 		phys_dev = node->dev;
657 	}
658 	mutex_unlock(physical_node_lock);
659 	return phys_dev;
660 }
661 EXPORT_SYMBOL_GPL(acpi_get_first_physical_node);
662 
663 static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
664 						      const struct device *dev)
665 {
666 	const struct device *phys_dev = acpi_get_first_physical_node(adev);
667 
668 	return phys_dev && phys_dev == dev ? adev : NULL;
669 }
670 
671 /**
672  * acpi_device_is_first_physical_node - Is given dev first physical node
673  * @adev: ACPI companion device
674  * @dev: Physical device to check
675  *
676  * Function checks if given @dev is the first physical devices attached to
677  * the ACPI companion device. This distinction is needed in some cases
678  * where the same companion device is shared between many physical devices.
679  *
680  * Note that the caller have to provide valid @adev pointer.
681  */
682 bool acpi_device_is_first_physical_node(struct acpi_device *adev,
683 					const struct device *dev)
684 {
685 	return !!acpi_primary_dev_companion(adev, dev);
686 }
687 
688 /*
689  * acpi_companion_match() - Can we match via ACPI companion device
690  * @dev: Device in question
691  *
692  * Check if the given device has an ACPI companion and if that companion has
693  * a valid list of PNP IDs, and if the device is the first (primary) physical
694  * device associated with it.  Return the companion pointer if that's the case
695  * or NULL otherwise.
696  *
697  * If multiple physical devices are attached to a single ACPI companion, we need
698  * to be careful.  The usage scenario for this kind of relationship is that all
699  * of the physical devices in question use resources provided by the ACPI
700  * companion.  A typical case is an MFD device where all the sub-devices share
701  * the parent's ACPI companion.  In such cases we can only allow the primary
702  * (first) physical device to be matched with the help of the companion's PNP
703  * IDs.
704  *
705  * Additional physical devices sharing the ACPI companion can still use
706  * resources available from it but they will be matched normally using functions
707  * provided by their bus types (and analogously for their modalias).
708  */
709 const struct acpi_device *acpi_companion_match(const struct device *dev)
710 {
711 	struct acpi_device *adev;
712 
713 	adev = ACPI_COMPANION(dev);
714 	if (!adev)
715 		return NULL;
716 
717 	if (list_empty(&adev->pnp.ids))
718 		return NULL;
719 
720 	return acpi_primary_dev_companion(adev, dev);
721 }
722 
723 /**
724  * acpi_of_match_device - Match device object using the "compatible" property.
725  * @adev: ACPI device object to match.
726  * @of_match_table: List of device IDs to match against.
727  * @of_id: OF ID if matched
728  *
729  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
730  * identifiers and a _DSD object with the "compatible" property, use that
731  * property to match against the given list of identifiers.
732  */
733 static bool acpi_of_match_device(const struct acpi_device *adev,
734 				 const struct of_device_id *of_match_table,
735 				 const struct of_device_id **of_id)
736 {
737 	const union acpi_object *of_compatible, *obj;
738 	int i, nval;
739 
740 	if (!adev)
741 		return false;
742 
743 	of_compatible = adev->data.of_compatible;
744 	if (!of_match_table || !of_compatible)
745 		return false;
746 
747 	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
748 		nval = of_compatible->package.count;
749 		obj = of_compatible->package.elements;
750 	} else { /* Must be ACPI_TYPE_STRING. */
751 		nval = 1;
752 		obj = of_compatible;
753 	}
754 	/* Now we can look for the driver DT compatible strings */
755 	for (i = 0; i < nval; i++, obj++) {
756 		const struct of_device_id *id;
757 
758 		for (id = of_match_table; id->compatible[0]; id++)
759 			if (!strcasecmp(obj->string.pointer, id->compatible)) {
760 				if (of_id)
761 					*of_id = id;
762 				return true;
763 			}
764 	}
765 
766 	return false;
767 }
768 
769 static bool acpi_of_modalias(struct acpi_device *adev,
770 			     char *modalias, size_t len)
771 {
772 	const union acpi_object *of_compatible;
773 	const union acpi_object *obj;
774 	const char *str, *chr;
775 
776 	of_compatible = adev->data.of_compatible;
777 	if (!of_compatible)
778 		return false;
779 
780 	if (of_compatible->type == ACPI_TYPE_PACKAGE)
781 		obj = of_compatible->package.elements;
782 	else /* Must be ACPI_TYPE_STRING. */
783 		obj = of_compatible;
784 
785 	str = obj->string.pointer;
786 	chr = strchr(str, ',');
787 	strscpy(modalias, chr ? chr + 1 : str, len);
788 
789 	return true;
790 }
791 
792 /**
793  * acpi_set_modalias - Set modalias using "compatible" property or supplied ID
794  * @adev:	ACPI device object to match
795  * @default_id:	ID string to use as default if no compatible string found
796  * @modalias:   Pointer to buffer that modalias value will be copied into
797  * @len:	Length of modalias buffer
798  *
799  * This is a counterpart of of_alias_from_compatible() for struct acpi_device
800  * objects. If there is a compatible string for @adev, it will be copied to
801  * @modalias with the vendor prefix stripped; otherwise, @default_id will be
802  * used.
803  */
804 void acpi_set_modalias(struct acpi_device *adev, const char *default_id,
805 		       char *modalias, size_t len)
806 {
807 	if (!acpi_of_modalias(adev, modalias, len))
808 		strscpy(modalias, default_id, len);
809 }
810 EXPORT_SYMBOL_GPL(acpi_set_modalias);
811 
812 static bool __acpi_match_device_cls(const struct acpi_device_id *id,
813 				    struct acpi_hardware_id *hwid)
814 {
815 	int i, msk, byte_shift;
816 	char buf[3];
817 
818 	if (!id->cls)
819 		return false;
820 
821 	/* Apply class-code bitmask, before checking each class-code byte */
822 	for (i = 1; i <= 3; i++) {
823 		byte_shift = 8 * (3 - i);
824 		msk = (id->cls_msk >> byte_shift) & 0xFF;
825 		if (!msk)
826 			continue;
827 
828 		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
829 		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
830 			return false;
831 	}
832 	return true;
833 }
834 
835 static bool __acpi_match_device(const struct acpi_device *device,
836 				const struct acpi_device_id *acpi_ids,
837 				const struct of_device_id *of_ids,
838 				const struct acpi_device_id **acpi_id,
839 				const struct of_device_id **of_id)
840 {
841 	const struct acpi_device_id *id;
842 	struct acpi_hardware_id *hwid;
843 
844 	/*
845 	 * If the device is not present, it is unnecessary to load device
846 	 * driver for it.
847 	 */
848 	if (!device || !device->status.present)
849 		return false;
850 
851 	list_for_each_entry(hwid, &device->pnp.ids, list) {
852 		/* First, check the ACPI/PNP IDs provided by the caller. */
853 		if (acpi_ids) {
854 			for (id = acpi_ids; id->id[0] || id->cls; id++) {
855 				if (id->id[0] && !strcmp((char *)id->id, hwid->id))
856 					goto out_acpi_match;
857 				if (id->cls && __acpi_match_device_cls(id, hwid))
858 					goto out_acpi_match;
859 			}
860 		}
861 
862 		/*
863 		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
864 		 * "compatible" property if found.
865 		 */
866 		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id))
867 			return acpi_of_match_device(device, of_ids, of_id);
868 	}
869 	return false;
870 
871 out_acpi_match:
872 	if (acpi_id)
873 		*acpi_id = id;
874 	return true;
875 }
876 
877 /**
878  * acpi_match_acpi_device - Match an ACPI device against a given list of ACPI IDs
879  * @ids: Array of struct acpi_device_id objects to match against.
880  * @adev: The ACPI device pointer to match.
881  *
882  * Match the ACPI device @adev against a given list of ACPI IDs @ids.
883  *
884  * Return:
885  * a pointer to the first matching ACPI ID on success or %NULL on failure.
886  */
887 const struct acpi_device_id *acpi_match_acpi_device(const struct acpi_device_id *ids,
888 						    const struct acpi_device *adev)
889 {
890 	const struct acpi_device_id *id = NULL;
891 
892 	__acpi_match_device(adev, ids, NULL, &id, NULL);
893 	return id;
894 }
895 EXPORT_SYMBOL_GPL(acpi_match_acpi_device);
896 
897 /**
898  * acpi_match_device - Match a struct device against a given list of ACPI IDs
899  * @ids: Array of struct acpi_device_id object to match against.
900  * @dev: The device structure to match.
901  *
902  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
903  * object for that handle and use that object to match against a given list of
904  * device IDs.
905  *
906  * Return a pointer to the first matching ID on success or %NULL on failure.
907  */
908 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
909 					       const struct device *dev)
910 {
911 	return acpi_match_acpi_device(ids, acpi_companion_match(dev));
912 }
913 EXPORT_SYMBOL_GPL(acpi_match_device);
914 
915 static const void *acpi_of_device_get_match_data(const struct device *dev)
916 {
917 	struct acpi_device *adev = ACPI_COMPANION(dev);
918 	const struct of_device_id *match = NULL;
919 
920 	if (!acpi_of_match_device(adev, dev->driver->of_match_table, &match))
921 		return NULL;
922 
923 	return match->data;
924 }
925 
926 const void *acpi_device_get_match_data(const struct device *dev)
927 {
928 	const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
929 	const struct acpi_device_id *match;
930 
931 	if (!acpi_ids)
932 		return acpi_of_device_get_match_data(dev);
933 
934 	match = acpi_match_device(acpi_ids, dev);
935 	if (!match)
936 		return NULL;
937 
938 	return (const void *)match->driver_data;
939 }
940 EXPORT_SYMBOL_GPL(acpi_device_get_match_data);
941 
942 int acpi_match_device_ids(struct acpi_device *device,
943 			  const struct acpi_device_id *ids)
944 {
945 	return __acpi_match_device(device, ids, NULL, NULL, NULL) ? 0 : -ENOENT;
946 }
947 EXPORT_SYMBOL(acpi_match_device_ids);
948 
949 bool acpi_driver_match_device(struct device *dev,
950 			      const struct device_driver *drv)
951 {
952 	const struct acpi_device_id *acpi_ids = drv->acpi_match_table;
953 	const struct of_device_id *of_ids = drv->of_match_table;
954 
955 	if (!acpi_ids)
956 		return acpi_of_match_device(ACPI_COMPANION(dev), of_ids, NULL);
957 
958 	return __acpi_match_device(acpi_companion_match(dev), acpi_ids, of_ids, NULL, NULL);
959 }
960 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
961 
962 /* --------------------------------------------------------------------------
963                               ACPI Driver Management
964    -------------------------------------------------------------------------- */
965 
966 /**
967  * acpi_bus_register_driver - register a driver with the ACPI bus
968  * @driver: driver being registered
969  *
970  * Registers a driver with the ACPI bus.  Searches the namespace for all
971  * devices that match the driver's criteria and binds.  Returns zero for
972  * success or a negative error status for failure.
973  */
974 int acpi_bus_register_driver(struct acpi_driver *driver)
975 {
976 	if (acpi_disabled)
977 		return -ENODEV;
978 	driver->drv.name = driver->name;
979 	driver->drv.bus = &acpi_bus_type;
980 	driver->drv.owner = driver->owner;
981 
982 	return driver_register(&driver->drv);
983 }
984 
985 EXPORT_SYMBOL(acpi_bus_register_driver);
986 
987 /**
988  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
989  * @driver: driver to unregister
990  *
991  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
992  * devices that match the driver's criteria and unbinds.
993  */
994 void acpi_bus_unregister_driver(struct acpi_driver *driver)
995 {
996 	driver_unregister(&driver->drv);
997 }
998 
999 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1000 
1001 /* --------------------------------------------------------------------------
1002                               ACPI Bus operations
1003    -------------------------------------------------------------------------- */
1004 
1005 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1006 {
1007 	struct acpi_device *acpi_dev = to_acpi_device(dev);
1008 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1009 
1010 	return acpi_dev->flags.match_driver
1011 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1012 }
1013 
1014 static int acpi_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
1015 {
1016 	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1017 }
1018 
1019 static int acpi_device_probe(struct device *dev)
1020 {
1021 	struct acpi_device *acpi_dev = to_acpi_device(dev);
1022 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1023 	int ret;
1024 
1025 	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1026 		return -EINVAL;
1027 
1028 	if (!acpi_drv->ops.add)
1029 		return -ENOSYS;
1030 
1031 	ret = acpi_drv->ops.add(acpi_dev);
1032 	if (ret) {
1033 		acpi_dev->driver_data = NULL;
1034 		return ret;
1035 	}
1036 
1037 	pr_debug("Driver [%s] successfully bound to device [%s]\n",
1038 		 acpi_drv->name, acpi_dev->pnp.bus_id);
1039 
1040 	if (acpi_drv->ops.notify) {
1041 		ret = acpi_device_install_notify_handler(acpi_dev, acpi_drv);
1042 		if (ret) {
1043 			if (acpi_drv->ops.remove)
1044 				acpi_drv->ops.remove(acpi_dev);
1045 
1046 			acpi_dev->driver_data = NULL;
1047 			return ret;
1048 		}
1049 	}
1050 
1051 	pr_debug("Found driver [%s] for device [%s]\n", acpi_drv->name,
1052 		 acpi_dev->pnp.bus_id);
1053 
1054 	get_device(dev);
1055 	return 0;
1056 }
1057 
1058 static void acpi_device_remove(struct device *dev)
1059 {
1060 	struct acpi_device *acpi_dev = to_acpi_device(dev);
1061 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1062 
1063 	if (acpi_drv->ops.notify)
1064 		acpi_device_remove_notify_handler(acpi_dev, acpi_drv);
1065 
1066 	if (acpi_drv->ops.remove)
1067 		acpi_drv->ops.remove(acpi_dev);
1068 
1069 	acpi_dev->driver_data = NULL;
1070 
1071 	put_device(dev);
1072 }
1073 
1074 struct bus_type acpi_bus_type = {
1075 	.name		= "acpi",
1076 	.match		= acpi_bus_match,
1077 	.probe		= acpi_device_probe,
1078 	.remove		= acpi_device_remove,
1079 	.uevent		= acpi_device_uevent,
1080 };
1081 
1082 int acpi_bus_for_each_dev(int (*fn)(struct device *, void *), void *data)
1083 {
1084 	return bus_for_each_dev(&acpi_bus_type, NULL, data, fn);
1085 }
1086 EXPORT_SYMBOL_GPL(acpi_bus_for_each_dev);
1087 
1088 struct acpi_dev_walk_context {
1089 	int (*fn)(struct acpi_device *, void *);
1090 	void *data;
1091 };
1092 
1093 static int acpi_dev_for_one_check(struct device *dev, void *context)
1094 {
1095 	struct acpi_dev_walk_context *adwc = context;
1096 
1097 	if (dev->bus != &acpi_bus_type)
1098 		return 0;
1099 
1100 	return adwc->fn(to_acpi_device(dev), adwc->data);
1101 }
1102 EXPORT_SYMBOL_GPL(acpi_dev_for_each_child);
1103 
1104 int acpi_dev_for_each_child(struct acpi_device *adev,
1105 			    int (*fn)(struct acpi_device *, void *), void *data)
1106 {
1107 	struct acpi_dev_walk_context adwc = {
1108 		.fn = fn,
1109 		.data = data,
1110 	};
1111 
1112 	return device_for_each_child(&adev->dev, &adwc, acpi_dev_for_one_check);
1113 }
1114 
1115 int acpi_dev_for_each_child_reverse(struct acpi_device *adev,
1116 				    int (*fn)(struct acpi_device *, void *),
1117 				    void *data)
1118 {
1119 	struct acpi_dev_walk_context adwc = {
1120 		.fn = fn,
1121 		.data = data,
1122 	};
1123 
1124 	return device_for_each_child_reverse(&adev->dev, &adwc, acpi_dev_for_one_check);
1125 }
1126 
1127 /* --------------------------------------------------------------------------
1128                              Initialization/Cleanup
1129    -------------------------------------------------------------------------- */
1130 
1131 static int __init acpi_bus_init_irq(void)
1132 {
1133 	acpi_status status;
1134 	char *message = NULL;
1135 
1136 
1137 	/*
1138 	 * Let the system know what interrupt model we are using by
1139 	 * evaluating the \_PIC object, if exists.
1140 	 */
1141 
1142 	switch (acpi_irq_model) {
1143 	case ACPI_IRQ_MODEL_PIC:
1144 		message = "PIC";
1145 		break;
1146 	case ACPI_IRQ_MODEL_IOAPIC:
1147 		message = "IOAPIC";
1148 		break;
1149 	case ACPI_IRQ_MODEL_IOSAPIC:
1150 		message = "IOSAPIC";
1151 		break;
1152 	case ACPI_IRQ_MODEL_GIC:
1153 		message = "GIC";
1154 		break;
1155 	case ACPI_IRQ_MODEL_PLATFORM:
1156 		message = "platform specific model";
1157 		break;
1158 	case ACPI_IRQ_MODEL_LPIC:
1159 		message = "LPIC";
1160 		break;
1161 	default:
1162 		pr_info("Unknown interrupt routing model\n");
1163 		return -ENODEV;
1164 	}
1165 
1166 	pr_info("Using %s for interrupt routing\n", message);
1167 
1168 	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
1169 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
1170 		pr_info("_PIC evaluation failed: %s\n", acpi_format_exception(status));
1171 		return -ENODEV;
1172 	}
1173 
1174 	return 0;
1175 }
1176 
1177 /**
1178  * acpi_early_init - Initialize ACPICA and populate the ACPI namespace.
1179  *
1180  * The ACPI tables are accessible after this, but the handling of events has not
1181  * been initialized and the global lock is not available yet, so AML should not
1182  * be executed at this point.
1183  *
1184  * Doing this before switching the EFI runtime services to virtual mode allows
1185  * the EfiBootServices memory to be freed slightly earlier on boot.
1186  */
1187 void __init acpi_early_init(void)
1188 {
1189 	acpi_status status;
1190 
1191 	if (acpi_disabled)
1192 		return;
1193 
1194 	pr_info("Core revision %08x\n", ACPI_CA_VERSION);
1195 
1196 	/* enable workarounds, unless strict ACPI spec. compliance */
1197 	if (!acpi_strict)
1198 		acpi_gbl_enable_interpreter_slack = TRUE;
1199 
1200 	acpi_permanent_mmap = true;
1201 
1202 #ifdef CONFIG_X86
1203 	/*
1204 	 * If the machine falls into the DMI check table,
1205 	 * DSDT will be copied to memory.
1206 	 * Note that calling dmi_check_system() here on other architectures
1207 	 * would not be OK because only x86 initializes dmi early enough.
1208 	 * Thankfully only x86 systems need such quirks for now.
1209 	 */
1210 	dmi_check_system(dsdt_dmi_table);
1211 #endif
1212 
1213 	status = acpi_reallocate_root_table();
1214 	if (ACPI_FAILURE(status)) {
1215 		pr_err("Unable to reallocate ACPI tables\n");
1216 		goto error0;
1217 	}
1218 
1219 	status = acpi_initialize_subsystem();
1220 	if (ACPI_FAILURE(status)) {
1221 		pr_err("Unable to initialize the ACPI Interpreter\n");
1222 		goto error0;
1223 	}
1224 
1225 #ifdef CONFIG_X86
1226 	if (!acpi_ioapic) {
1227 		/* compatible (0) means level (3) */
1228 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
1229 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
1230 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
1231 		}
1232 		/* Set PIC-mode SCI trigger type */
1233 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
1234 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
1235 	} else {
1236 		/*
1237 		 * now that acpi_gbl_FADT is initialized,
1238 		 * update it with result from INT_SRC_OVR parsing
1239 		 */
1240 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
1241 	}
1242 #endif
1243 	return;
1244 
1245  error0:
1246 	disable_acpi();
1247 }
1248 
1249 /**
1250  * acpi_subsystem_init - Finalize the early initialization of ACPI.
1251  *
1252  * Switch over the platform to the ACPI mode (if possible).
1253  *
1254  * Doing this too early is generally unsafe, but at the same time it needs to be
1255  * done before all things that really depend on ACPI.  The right spot appears to
1256  * be before finalizing the EFI initialization.
1257  */
1258 void __init acpi_subsystem_init(void)
1259 {
1260 	acpi_status status;
1261 
1262 	if (acpi_disabled)
1263 		return;
1264 
1265 	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
1266 	if (ACPI_FAILURE(status)) {
1267 		pr_err("Unable to enable ACPI\n");
1268 		disable_acpi();
1269 	} else {
1270 		/*
1271 		 * If the system is using ACPI then we can be reasonably
1272 		 * confident that any regulators are managed by the firmware
1273 		 * so tell the regulator core it has everything it needs to
1274 		 * know.
1275 		 */
1276 		regulator_has_full_constraints();
1277 	}
1278 }
1279 
1280 static acpi_status acpi_bus_table_handler(u32 event, void *table, void *context)
1281 {
1282 	if (event == ACPI_TABLE_EVENT_LOAD)
1283 		acpi_scan_table_notify();
1284 
1285 	return acpi_sysfs_table_handler(event, table, context);
1286 }
1287 
1288 static int __init acpi_bus_init(void)
1289 {
1290 	int result;
1291 	acpi_status status;
1292 
1293 	acpi_os_initialize1();
1294 
1295 	status = acpi_load_tables();
1296 	if (ACPI_FAILURE(status)) {
1297 		pr_err("Unable to load the System Description Tables\n");
1298 		goto error1;
1299 	}
1300 
1301 	/*
1302 	 * ACPI 2.0 requires the EC driver to be loaded and work before the EC
1303 	 * device is found in the namespace.
1304 	 *
1305 	 * This is accomplished by looking for the ECDT table and getting the EC
1306 	 * parameters out of that.
1307 	 *
1308 	 * Do that before calling acpi_initialize_objects() which may trigger EC
1309 	 * address space accesses.
1310 	 */
1311 	acpi_ec_ecdt_probe();
1312 
1313 	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
1314 	if (ACPI_FAILURE(status)) {
1315 		pr_err("Unable to start the ACPI Interpreter\n");
1316 		goto error1;
1317 	}
1318 
1319 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
1320 	if (ACPI_FAILURE(status)) {
1321 		pr_err("Unable to initialize ACPI objects\n");
1322 		goto error1;
1323 	}
1324 
1325 	/*
1326 	 * _OSC method may exist in module level code,
1327 	 * so it must be run after ACPI_FULL_INITIALIZATION
1328 	 */
1329 	acpi_bus_osc_negotiate_platform_control();
1330 	acpi_bus_osc_negotiate_usb_control();
1331 
1332 	/*
1333 	 * _PDC control method may load dynamic SSDT tables,
1334 	 * and we need to install the table handler before that.
1335 	 */
1336 	status = acpi_install_table_handler(acpi_bus_table_handler, NULL);
1337 
1338 	acpi_sysfs_init();
1339 
1340 	acpi_early_processor_control_setup();
1341 
1342 	/*
1343 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
1344 	 * is necessary to enable it as early as possible.
1345 	 */
1346 	acpi_ec_dsdt_probe();
1347 
1348 	pr_info("Interpreter enabled\n");
1349 
1350 	/* Initialize sleep structures */
1351 	acpi_sleep_init();
1352 
1353 	/*
1354 	 * Get the system interrupt model and evaluate \_PIC.
1355 	 */
1356 	result = acpi_bus_init_irq();
1357 	if (result)
1358 		goto error1;
1359 
1360 	/*
1361 	 * Register the for all standard device notifications.
1362 	 */
1363 	status =
1364 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
1365 					&acpi_bus_notify, NULL);
1366 	if (ACPI_FAILURE(status)) {
1367 		pr_err("Unable to register for system notifications\n");
1368 		goto error1;
1369 	}
1370 
1371 	/*
1372 	 * Create the top ACPI proc directory
1373 	 */
1374 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
1375 
1376 	result = bus_register(&acpi_bus_type);
1377 	if (!result)
1378 		return 0;
1379 
1380 	/* Mimic structured exception handling */
1381       error1:
1382 	acpi_terminate();
1383 	return -ENODEV;
1384 }
1385 
1386 struct kobject *acpi_kobj;
1387 EXPORT_SYMBOL_GPL(acpi_kobj);
1388 
1389 static int __init acpi_init(void)
1390 {
1391 	int result;
1392 
1393 	if (acpi_disabled) {
1394 		pr_info("Interpreter disabled.\n");
1395 		return -ENODEV;
1396 	}
1397 
1398 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
1399 	if (!acpi_kobj)
1400 		pr_debug("%s: kset create error\n", __func__);
1401 
1402 	init_prmt();
1403 	acpi_init_pcc();
1404 	result = acpi_bus_init();
1405 	if (result) {
1406 		kobject_put(acpi_kobj);
1407 		disable_acpi();
1408 		return result;
1409 	}
1410 	acpi_init_ffh();
1411 
1412 	pci_mmcfg_late_init();
1413 	acpi_viot_early_init();
1414 	acpi_hest_init();
1415 	acpi_ghes_init();
1416 	acpi_arm_init();
1417 	acpi_scan_init();
1418 	acpi_ec_init();
1419 	acpi_debugfs_init();
1420 	acpi_sleep_proc_init();
1421 	acpi_wakeup_device_init();
1422 	acpi_debugger_init();
1423 	acpi_setup_sb_notify_handler();
1424 	acpi_viot_init();
1425 	return 0;
1426 }
1427 
1428 subsys_initcall(acpi_init);
1429