xref: /openbmc/linux/drivers/acpi/acpica/evxfregn.c (revision 6a143a7c)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: evxfregn - External Interfaces, ACPI Operation Regions and
5  *                         Address Spaces.
6  *
7  * Copyright (C) 2000 - 2021, Intel Corp.
8  *
9  *****************************************************************************/
10 
11 #define EXPORT_ACPI_INTERFACES
12 
13 #include <acpi/acpi.h>
14 #include "accommon.h"
15 #include "acnamesp.h"
16 #include "acevents.h"
17 
18 #define _COMPONENT          ACPI_EVENTS
19 ACPI_MODULE_NAME("evxfregn")
20 
21 /*******************************************************************************
22  *
23  * FUNCTION:    acpi_install_address_space_handler
24  *
25  * PARAMETERS:  device          - Handle for the device
26  *              space_id        - The address space ID
27  *              handler         - Address of the handler
28  *              setup           - Address of the setup function
29  *              context         - Value passed to the handler on each access
30  *
31  * RETURN:      Status
32  *
33  * DESCRIPTION: Install a handler for all op_regions of a given space_id.
34  *
35  * NOTE: This function should only be called after acpi_enable_subsystem has
36  * been called. This is because any _REG methods associated with the Space ID
37  * are executed here, and these methods can only be safely executed after
38  * the default handlers have been installed and the hardware has been
39  * initialized (via acpi_enable_subsystem.)
40  *
41  ******************************************************************************/
42 acpi_status
43 acpi_install_address_space_handler(acpi_handle device,
44 				   acpi_adr_space_type space_id,
45 				   acpi_adr_space_handler handler,
46 				   acpi_adr_space_setup setup, void *context)
47 {
48 	struct acpi_namespace_node *node;
49 	acpi_status status;
50 
51 	ACPI_FUNCTION_TRACE(acpi_install_address_space_handler);
52 
53 	/* Parameter validation */
54 
55 	if (!device) {
56 		return_ACPI_STATUS(AE_BAD_PARAMETER);
57 	}
58 
59 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
60 	if (ACPI_FAILURE(status)) {
61 		return_ACPI_STATUS(status);
62 	}
63 
64 	/* Convert and validate the device handle */
65 
66 	node = acpi_ns_validate_handle(device);
67 	if (!node) {
68 		status = AE_BAD_PARAMETER;
69 		goto unlock_and_exit;
70 	}
71 
72 	/* Install the handler for all Regions for this Space ID */
73 
74 	status =
75 	    acpi_ev_install_space_handler(node, space_id, handler, setup,
76 					  context);
77 	if (ACPI_FAILURE(status)) {
78 		goto unlock_and_exit;
79 	}
80 
81 	/* Run all _REG methods for this address space */
82 
83 	acpi_ev_execute_reg_methods(node, space_id, ACPI_REG_CONNECT);
84 
85 unlock_and_exit:
86 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
87 	return_ACPI_STATUS(status);
88 }
89 
90 ACPI_EXPORT_SYMBOL(acpi_install_address_space_handler)
91 
92 /*******************************************************************************
93  *
94  * FUNCTION:    acpi_remove_address_space_handler
95  *
96  * PARAMETERS:  device          - Handle for the device
97  *              space_id        - The address space ID
98  *              handler         - Address of the handler
99  *
100  * RETURN:      Status
101  *
102  * DESCRIPTION: Remove a previously installed handler.
103  *
104  ******************************************************************************/
105 acpi_status
106 acpi_remove_address_space_handler(acpi_handle device,
107 				  acpi_adr_space_type space_id,
108 				  acpi_adr_space_handler handler)
109 {
110 	union acpi_operand_object *obj_desc;
111 	union acpi_operand_object *handler_obj;
112 	union acpi_operand_object *region_obj;
113 	union acpi_operand_object **last_obj_ptr;
114 	struct acpi_namespace_node *node;
115 	acpi_status status;
116 
117 	ACPI_FUNCTION_TRACE(acpi_remove_address_space_handler);
118 
119 	/* Parameter validation */
120 
121 	if (!device) {
122 		return_ACPI_STATUS(AE_BAD_PARAMETER);
123 	}
124 
125 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
126 	if (ACPI_FAILURE(status)) {
127 		return_ACPI_STATUS(status);
128 	}
129 
130 	/* Convert and validate the device handle */
131 
132 	node = acpi_ns_validate_handle(device);
133 	if (!node ||
134 	    ((node->type != ACPI_TYPE_DEVICE) &&
135 	     (node->type != ACPI_TYPE_PROCESSOR) &&
136 	     (node->type != ACPI_TYPE_THERMAL) &&
137 	     (node != acpi_gbl_root_node))) {
138 		status = AE_BAD_PARAMETER;
139 		goto unlock_and_exit;
140 	}
141 
142 	/* Make sure the internal object exists */
143 
144 	obj_desc = acpi_ns_get_attached_object(node);
145 	if (!obj_desc) {
146 		status = AE_NOT_EXIST;
147 		goto unlock_and_exit;
148 	}
149 
150 	/* Find the address handler the user requested */
151 
152 	handler_obj = obj_desc->common_notify.handler;
153 	last_obj_ptr = &obj_desc->common_notify.handler;
154 	while (handler_obj) {
155 
156 		/* We have a handler, see if user requested this one */
157 
158 		if (handler_obj->address_space.space_id == space_id) {
159 
160 			/* Handler must be the same as the installed handler */
161 
162 			if (handler_obj->address_space.handler != handler) {
163 				status = AE_BAD_PARAMETER;
164 				goto unlock_and_exit;
165 			}
166 
167 			/* Matched space_id, first dereference this in the Regions */
168 
169 			ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
170 					  "Removing address handler %p(%p) for region %s "
171 					  "on Device %p(%p)\n",
172 					  handler_obj, handler,
173 					  acpi_ut_get_region_name(space_id),
174 					  node, obj_desc));
175 
176 			region_obj = handler_obj->address_space.region_list;
177 
178 			/* Walk the handler's region list */
179 
180 			while (region_obj) {
181 				/*
182 				 * First disassociate the handler from the region.
183 				 *
184 				 * NOTE: this doesn't mean that the region goes away
185 				 * The region is just inaccessible as indicated to
186 				 * the _REG method
187 				 */
188 				acpi_ev_detach_region(region_obj, TRUE);
189 
190 				/*
191 				 * Walk the list: Just grab the head because the
192 				 * detach_region removed the previous head.
193 				 */
194 				region_obj =
195 				    handler_obj->address_space.region_list;
196 			}
197 
198 			/* Remove this Handler object from the list */
199 
200 			*last_obj_ptr = handler_obj->address_space.next;
201 
202 			/* Now we can delete the handler object */
203 
204 			acpi_os_release_mutex(handler_obj->address_space.
205 					      context_mutex);
206 			acpi_ut_remove_reference(handler_obj);
207 			goto unlock_and_exit;
208 		}
209 
210 		/* Walk the linked list of handlers */
211 
212 		last_obj_ptr = &handler_obj->address_space.next;
213 		handler_obj = handler_obj->address_space.next;
214 	}
215 
216 	/* The handler does not exist */
217 
218 	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
219 			  "Unable to remove address handler %p for %s(%X), DevNode %p, obj %p\n",
220 			  handler, acpi_ut_get_region_name(space_id), space_id,
221 			  node, obj_desc));
222 
223 	status = AE_NOT_EXIST;
224 
225 unlock_and_exit:
226 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
227 	return_ACPI_STATUS(status);
228 }
229 
230 ACPI_EXPORT_SYMBOL(acpi_remove_address_space_handler)
231