1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: evhandler - Support for Address Space handlers
5 *
6 * Copyright (C) 2000 - 2023, Intel Corp.
7 *
8 *****************************************************************************/
9
10#include <acpi/acpi.h>
11#include "accommon.h"
12#include "acevents.h"
13#include "acnamesp.h"
14#include "acinterp.h"
15
16#define _COMPONENT          ACPI_EVENTS
17ACPI_MODULE_NAME("evhandler")
18
19/* Local prototypes */
20static acpi_status
21acpi_ev_install_handler(acpi_handle obj_handle,
22			u32 level, void *context, void **return_value);
23
24/* These are the address spaces that will get default handlers */
25
26u8 acpi_gbl_default_address_spaces[ACPI_NUM_DEFAULT_SPACES] = {
27	ACPI_ADR_SPACE_SYSTEM_MEMORY,
28	ACPI_ADR_SPACE_SYSTEM_IO,
29	ACPI_ADR_SPACE_PCI_CONFIG,
30	ACPI_ADR_SPACE_DATA_TABLE
31};
32
33/*******************************************************************************
34 *
35 * FUNCTION:    acpi_ev_install_region_handlers
36 *
37 * PARAMETERS:  None
38 *
39 * RETURN:      Status
40 *
41 * DESCRIPTION: Installs the core subsystem default address space handlers.
42 *
43 ******************************************************************************/
44
45acpi_status acpi_ev_install_region_handlers(void)
46{
47	acpi_status status;
48	u32 i;
49
50	ACPI_FUNCTION_TRACE(ev_install_region_handlers);
51
52	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
53	if (ACPI_FAILURE(status)) {
54		return_ACPI_STATUS(status);
55	}
56
57	/*
58	 * All address spaces (PCI Config, EC, SMBus) are scope dependent and
59	 * registration must occur for a specific device.
60	 *
61	 * In the case of the system memory and IO address spaces there is
62	 * currently no device associated with the address space. For these we
63	 * use the root.
64	 *
65	 * We install the default PCI config space handler at the root so that
66	 * this space is immediately available even though the we have not
67	 * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
68	 * specification which states that the PCI config space must be always
69	 * available -- even though we are nowhere near ready to find the PCI root
70	 * buses at this point.
71	 *
72	 * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
73	 * has already been installed (via acpi_install_address_space_handler).
74	 * Similar for AE_SAME_HANDLER.
75	 */
76	for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
77		status = acpi_ev_install_space_handler(acpi_gbl_root_node,
78						       acpi_gbl_default_address_spaces
79						       [i],
80						       ACPI_DEFAULT_HANDLER,
81						       NULL, NULL);
82		switch (status) {
83		case AE_OK:
84		case AE_SAME_HANDLER:
85		case AE_ALREADY_EXISTS:
86
87			/* These exceptions are all OK */
88
89			status = AE_OK;
90			break;
91
92		default:
93
94			goto unlock_and_exit;
95		}
96	}
97
98unlock_and_exit:
99	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
100	return_ACPI_STATUS(status);
101}
102
103/*******************************************************************************
104 *
105 * FUNCTION:    acpi_ev_has_default_handler
106 *
107 * PARAMETERS:  node                - Namespace node for the device
108 *              space_id            - The address space ID
109 *
110 * RETURN:      TRUE if default handler is installed, FALSE otherwise
111 *
112 * DESCRIPTION: Check if the default handler is installed for the requested
113 *              space ID.
114 *
115 ******************************************************************************/
116
117u8
118acpi_ev_has_default_handler(struct acpi_namespace_node *node,
119			    acpi_adr_space_type space_id)
120{
121	union acpi_operand_object *obj_desc;
122	union acpi_operand_object *handler_obj;
123
124	/* Must have an existing internal object */
125
126	obj_desc = acpi_ns_get_attached_object(node);
127	if (obj_desc) {
128		handler_obj = obj_desc->common_notify.handler;
129
130		/* Walk the linked list of handlers for this object */
131
132		while (handler_obj) {
133			if (handler_obj->address_space.space_id == space_id) {
134				if (handler_obj->address_space.handler_flags &
135				    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
136					return (TRUE);
137				}
138			}
139
140			handler_obj = handler_obj->address_space.next;
141		}
142	}
143
144	return (FALSE);
145}
146
147/*******************************************************************************
148 *
149 * FUNCTION:    acpi_ev_install_handler
150 *
151 * PARAMETERS:  walk_namespace callback
152 *
153 * DESCRIPTION: This routine installs an address handler into objects that are
154 *              of type Region or Device.
155 *
156 *              If the Object is a Device, and the device has a handler of
157 *              the same type then the search is terminated in that branch.
158 *
159 *              This is because the existing handler is closer in proximity
160 *              to any more regions than the one we are trying to install.
161 *
162 ******************************************************************************/
163
164static acpi_status
165acpi_ev_install_handler(acpi_handle obj_handle,
166			u32 level, void *context, void **return_value)
167{
168	union acpi_operand_object *handler_obj;
169	union acpi_operand_object *next_handler_obj;
170	union acpi_operand_object *obj_desc;
171	struct acpi_namespace_node *node;
172	acpi_status status;
173
174	ACPI_FUNCTION_NAME(ev_install_handler);
175
176	handler_obj = (union acpi_operand_object *)context;
177
178	/* Parameter validation */
179
180	if (!handler_obj) {
181		return (AE_OK);
182	}
183
184	/* Convert and validate the device handle */
185
186	node = acpi_ns_validate_handle(obj_handle);
187	if (!node) {
188		return (AE_BAD_PARAMETER);
189	}
190
191	/*
192	 * We only care about regions and objects that are allowed to have
193	 * address space handlers
194	 */
195	if ((node->type != ACPI_TYPE_DEVICE) &&
196	    (node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
197		return (AE_OK);
198	}
199
200	/* Check for an existing internal object */
201
202	obj_desc = acpi_ns_get_attached_object(node);
203	if (!obj_desc) {
204
205		/* No object, just exit */
206
207		return (AE_OK);
208	}
209
210	/* Devices are handled different than regions */
211
212	if (obj_desc->common.type == ACPI_TYPE_DEVICE) {
213
214		/* Check if this Device already has a handler for this address space */
215
216		next_handler_obj =
217		    acpi_ev_find_region_handler(handler_obj->address_space.
218						space_id,
219						obj_desc->common_notify.
220						handler);
221		if (next_handler_obj) {
222
223			/* Found a handler, is it for the same address space? */
224
225			ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
226					  "Found handler for region [%s] in device %p(%p) handler %p\n",
227					  acpi_ut_get_region_name(handler_obj->
228								  address_space.
229								  space_id),
230					  obj_desc, next_handler_obj,
231					  handler_obj));
232
233			/*
234			 * Since the object we found it on was a device, then it means
235			 * that someone has already installed a handler for the branch
236			 * of the namespace from this device on. Just bail out telling
237			 * the walk routine to not traverse this branch. This preserves
238			 * the scoping rule for handlers.
239			 */
240			return (AE_CTRL_DEPTH);
241		}
242
243		/*
244		 * As long as the device didn't have a handler for this space we
245		 * don't care about it. We just ignore it and proceed.
246		 */
247		return (AE_OK);
248	}
249
250	/* Object is a Region */
251
252	if (obj_desc->region.space_id != handler_obj->address_space.space_id) {
253
254		/* This region is for a different address space, just ignore it */
255
256		return (AE_OK);
257	}
258
259	/*
260	 * Now we have a region and it is for the handler's address space type.
261	 *
262	 * First disconnect region for any previous handler (if any)
263	 */
264	acpi_ev_detach_region(obj_desc, FALSE);
265
266	/* Connect the region to the new handler */
267
268	status = acpi_ev_attach_region(handler_obj, obj_desc, FALSE);
269	return (status);
270}
271
272/*******************************************************************************
273 *
274 * FUNCTION:    acpi_ev_find_region_handler
275 *
276 * PARAMETERS:  space_id        - The address space ID
277 *              handler_obj     - Head of the handler object list
278 *
279 * RETURN:      Matching handler object. NULL if space ID not matched
280 *
281 * DESCRIPTION: Search a handler object list for a match on the address
282 *              space ID.
283 *
284 ******************************************************************************/
285
286union acpi_operand_object *acpi_ev_find_region_handler(acpi_adr_space_type
287						       space_id,
288						       union acpi_operand_object
289						       *handler_obj)
290{
291
292	/* Walk the handler list for this device */
293
294	while (handler_obj) {
295
296		/* Same space_id indicates a handler is installed */
297
298		if (handler_obj->address_space.space_id == space_id) {
299			return (handler_obj);
300		}
301
302		/* Next handler object */
303
304		handler_obj = handler_obj->address_space.next;
305	}
306
307	return (NULL);
308}
309
310/*******************************************************************************
311 *
312 * FUNCTION:    acpi_ev_install_space_handler
313 *
314 * PARAMETERS:  node            - Namespace node for the device
315 *              space_id        - The address space ID
316 *              handler         - Address of the handler
317 *              setup           - Address of the setup function
318 *              context         - Value passed to the handler on each access
319 *
320 * RETURN:      Status
321 *
322 * DESCRIPTION: Install a handler for all op_regions of a given space_id.
323 *              Assumes namespace is locked
324 *
325 ******************************************************************************/
326
327acpi_status
328acpi_ev_install_space_handler(struct acpi_namespace_node *node,
329			      acpi_adr_space_type space_id,
330			      acpi_adr_space_handler handler,
331			      acpi_adr_space_setup setup, void *context)
332{
333	union acpi_operand_object *obj_desc;
334	union acpi_operand_object *handler_obj;
335	acpi_status status = AE_OK;
336	acpi_object_type type;
337	u8 flags = 0;
338
339	ACPI_FUNCTION_TRACE(ev_install_space_handler);
340
341	/*
342	 * This registration is valid for only the types below and the root.
343	 * The root node is where the default handlers get installed.
344	 */
345	if ((node->type != ACPI_TYPE_DEVICE) &&
346	    (node->type != ACPI_TYPE_PROCESSOR) &&
347	    (node->type != ACPI_TYPE_THERMAL) && (node != acpi_gbl_root_node)) {
348		status = AE_BAD_PARAMETER;
349		goto unlock_and_exit;
350	}
351
352	if (handler == ACPI_DEFAULT_HANDLER) {
353		flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;
354
355		switch (space_id) {
356		case ACPI_ADR_SPACE_SYSTEM_MEMORY:
357
358			handler = acpi_ex_system_memory_space_handler;
359			setup = acpi_ev_system_memory_region_setup;
360			break;
361
362		case ACPI_ADR_SPACE_SYSTEM_IO:
363
364			handler = acpi_ex_system_io_space_handler;
365			setup = acpi_ev_io_space_region_setup;
366			break;
367#ifdef ACPI_PCI_CONFIGURED
368		case ACPI_ADR_SPACE_PCI_CONFIG:
369
370			handler = acpi_ex_pci_config_space_handler;
371			setup = acpi_ev_pci_config_region_setup;
372			break;
373#endif
374		case ACPI_ADR_SPACE_CMOS:
375
376			handler = acpi_ex_cmos_space_handler;
377			setup = acpi_ev_cmos_region_setup;
378			break;
379#ifdef ACPI_PCI_CONFIGURED
380		case ACPI_ADR_SPACE_PCI_BAR_TARGET:
381
382			handler = acpi_ex_pci_bar_space_handler;
383			setup = acpi_ev_pci_bar_region_setup;
384			break;
385#endif
386		case ACPI_ADR_SPACE_DATA_TABLE:
387
388			handler = acpi_ex_data_table_space_handler;
389			setup = acpi_ev_data_table_region_setup;
390			break;
391
392		default:
393
394			status = AE_BAD_PARAMETER;
395			goto unlock_and_exit;
396		}
397	}
398
399	/* If the caller hasn't specified a setup routine, use the default */
400
401	if (!setup) {
402		setup = acpi_ev_default_region_setup;
403	}
404
405	/* Check for an existing internal object */
406
407	obj_desc = acpi_ns_get_attached_object(node);
408	if (obj_desc) {
409		/*
410		 * The attached device object already exists. Now make sure
411		 * the handler is not already installed.
412		 */
413		handler_obj = acpi_ev_find_region_handler(space_id,
414							  obj_desc->
415							  common_notify.
416							  handler);
417
418		if (handler_obj) {
419			if (handler_obj->address_space.handler == handler) {
420				/*
421				 * It is (relatively) OK to attempt to install the SAME
422				 * handler twice. This can easily happen with the
423				 * PCI_Config space.
424				 */
425				status = AE_SAME_HANDLER;
426				goto unlock_and_exit;
427			} else {
428				/* A handler is already installed */
429
430				status = AE_ALREADY_EXISTS;
431			}
432
433			goto unlock_and_exit;
434		}
435	} else {
436		ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
437				  "Creating object on Device %p while installing handler\n",
438				  node));
439
440		/* obj_desc does not exist, create one */
441
442		if (node->type == ACPI_TYPE_ANY) {
443			type = ACPI_TYPE_DEVICE;
444		} else {
445			type = node->type;
446		}
447
448		obj_desc = acpi_ut_create_internal_object(type);
449		if (!obj_desc) {
450			status = AE_NO_MEMORY;
451			goto unlock_and_exit;
452		}
453
454		/* Init new descriptor */
455
456		obj_desc->common.type = (u8)type;
457
458		/* Attach the new object to the Node */
459
460		status = acpi_ns_attach_object(node, obj_desc, type);
461
462		/* Remove local reference to the object */
463
464		acpi_ut_remove_reference(obj_desc);
465
466		if (ACPI_FAILURE(status)) {
467			goto unlock_and_exit;
468		}
469	}
470
471	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
472			  "Installing address handler for region %s(%X) "
473			  "on Device %4.4s %p(%p)\n",
474			  acpi_ut_get_region_name(space_id), space_id,
475			  acpi_ut_get_node_name(node), node, obj_desc));
476
477	/*
478	 * Install the handler
479	 *
480	 * At this point there is no existing handler. Just allocate the object
481	 * for the handler and link it into the list.
482	 */
483	handler_obj =
484	    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
485	if (!handler_obj) {
486		status = AE_NO_MEMORY;
487		goto unlock_and_exit;
488	}
489
490	/* Init handler obj */
491
492	status =
493	    acpi_os_create_mutex(&handler_obj->address_space.context_mutex);
494	if (ACPI_FAILURE(status)) {
495		acpi_ut_remove_reference(handler_obj);
496		goto unlock_and_exit;
497	}
498
499	handler_obj->address_space.space_id = (u8)space_id;
500	handler_obj->address_space.handler_flags = flags;
501	handler_obj->address_space.region_list = NULL;
502	handler_obj->address_space.node = node;
503	handler_obj->address_space.handler = handler;
504	handler_obj->address_space.context = context;
505	handler_obj->address_space.setup = setup;
506
507	/* Install at head of Device.address_space list */
508
509	handler_obj->address_space.next = obj_desc->common_notify.handler;
510
511	/*
512	 * The Device object is the first reference on the handler_obj.
513	 * Each region that uses the handler adds a reference.
514	 */
515	obj_desc->common_notify.handler = handler_obj;
516
517	/*
518	 * Walk the namespace finding all of the regions this handler will
519	 * manage.
520	 *
521	 * Start at the device and search the branch toward the leaf nodes
522	 * until either the leaf is encountered or a device is detected that
523	 * has an address handler of the same type.
524	 *
525	 * In either case, back up and search down the remainder of the branch
526	 */
527	status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node,
528					ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
529					acpi_ev_install_handler, NULL,
530					handler_obj, NULL);
531
532unlock_and_exit:
533	return_ACPI_STATUS(status);
534}
535