Merge tag 'docs-4.12-2' of git://git.lwn.net/linux
[sfrench/cifs-2.6.git] / drivers / acpi / acpica / exstoren.c
1 /******************************************************************************
2  *
3  * Module Name: exstoren - AML Interpreter object store support,
4  *                        Store to Node (namespace object)
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2017, Intel Corp.
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44
45 #include <acpi/acpi.h>
46 #include "accommon.h"
47 #include "acinterp.h"
48 #include "amlcode.h"
49
50 #define _COMPONENT          ACPI_EXECUTER
51 ACPI_MODULE_NAME("exstoren")
52
53 /*******************************************************************************
54  *
55  * FUNCTION:    acpi_ex_resolve_object
56  *
57  * PARAMETERS:  source_desc_ptr     - Pointer to the source object
58  *              target_type         - Current type of the target
59  *              walk_state          - Current walk state
60  *
61  * RETURN:      Status, resolved object in source_desc_ptr.
62  *
63  * DESCRIPTION: Resolve an object. If the object is a reference, dereference
64  *              it and return the actual object in the source_desc_ptr.
65  *
66  ******************************************************************************/
67 acpi_status
68 acpi_ex_resolve_object(union acpi_operand_object **source_desc_ptr,
69                        acpi_object_type target_type,
70                        struct acpi_walk_state *walk_state)
71 {
72         union acpi_operand_object *source_desc = *source_desc_ptr;
73         acpi_status status = AE_OK;
74
75         ACPI_FUNCTION_TRACE(ex_resolve_object);
76
77         /* Ensure we have a Target that can be stored to */
78
79         switch (target_type) {
80         case ACPI_TYPE_BUFFER_FIELD:
81         case ACPI_TYPE_LOCAL_REGION_FIELD:
82         case ACPI_TYPE_LOCAL_BANK_FIELD:
83         case ACPI_TYPE_LOCAL_INDEX_FIELD:
84                 /*
85                  * These cases all require only Integers or values that
86                  * can be converted to Integers (Strings or Buffers)
87                  */
88         case ACPI_TYPE_INTEGER:
89         case ACPI_TYPE_STRING:
90         case ACPI_TYPE_BUFFER:
91                 /*
92                  * Stores into a Field/Region or into a Integer/Buffer/String
93                  * are all essentially the same. This case handles the
94                  * "interchangeable" types Integer, String, and Buffer.
95                  */
96                 if (source_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
97
98                         /* Resolve a reference object first */
99
100                         status =
101                             acpi_ex_resolve_to_value(source_desc_ptr,
102                                                      walk_state);
103                         if (ACPI_FAILURE(status)) {
104                                 break;
105                         }
106                 }
107
108                 /* For copy_object, no further validation necessary */
109
110                 if (walk_state->opcode == AML_COPY_OBJECT_OP) {
111                         break;
112                 }
113
114                 /* Must have a Integer, Buffer, or String */
115
116                 if ((source_desc->common.type != ACPI_TYPE_INTEGER) &&
117                     (source_desc->common.type != ACPI_TYPE_BUFFER) &&
118                     (source_desc->common.type != ACPI_TYPE_STRING) &&
119                     !((source_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) &&
120                       (source_desc->reference.class == ACPI_REFCLASS_TABLE))) {
121
122                         /* Conversion successful but still not a valid type */
123
124                         ACPI_ERROR((AE_INFO,
125                                     "Cannot assign type [%s] to [%s] (must be type Int/Str/Buf)",
126                                     acpi_ut_get_object_type_name(source_desc),
127                                     acpi_ut_get_type_name(target_type)));
128
129                         status = AE_AML_OPERAND_TYPE;
130                 }
131                 break;
132
133         case ACPI_TYPE_LOCAL_ALIAS:
134         case ACPI_TYPE_LOCAL_METHOD_ALIAS:
135                 /*
136                  * All aliases should have been resolved earlier, during the
137                  * operand resolution phase.
138                  */
139                 ACPI_ERROR((AE_INFO, "Store into an unresolved Alias object"));
140                 status = AE_AML_INTERNAL;
141                 break;
142
143         case ACPI_TYPE_PACKAGE:
144         default:
145                 /*
146                  * All other types than Alias and the various Fields come here,
147                  * including the untyped case - ACPI_TYPE_ANY.
148                  */
149                 break;
150         }
151
152         return_ACPI_STATUS(status);
153 }
154
155 /*******************************************************************************
156  *
157  * FUNCTION:    acpi_ex_store_object_to_object
158  *
159  * PARAMETERS:  source_desc         - Object to store
160  *              dest_desc           - Object to receive a copy of the source
161  *              new_desc            - New object if dest_desc is obsoleted
162  *              walk_state          - Current walk state
163  *
164  * RETURN:      Status
165  *
166  * DESCRIPTION: "Store" an object to another object. This may include
167  *              converting the source type to the target type (implicit
168  *              conversion), and a copy of the value of the source to
169  *              the target.
170  *
171  *              The Assignment of an object to another (not named) object
172  *              is handled here.
173  *              The Source passed in will replace the current value (if any)
174  *              with the input value.
175  *
176  *              When storing into an object the data is converted to the
177  *              target object type then stored in the object. This means
178  *              that the target object type (for an initialized target) will
179  *              not be changed by a store operation.
180  *
181  *              This module allows destination types of Number, String,
182  *              Buffer, and Package.
183  *
184  *              Assumes parameters are already validated. NOTE: source_desc
185  *              resolution (from a reference object) must be performed by
186  *              the caller if necessary.
187  *
188  ******************************************************************************/
189
190 acpi_status
191 acpi_ex_store_object_to_object(union acpi_operand_object *source_desc,
192                                union acpi_operand_object *dest_desc,
193                                union acpi_operand_object **new_desc,
194                                struct acpi_walk_state *walk_state)
195 {
196         union acpi_operand_object *actual_src_desc;
197         acpi_status status = AE_OK;
198
199         ACPI_FUNCTION_TRACE_PTR(ex_store_object_to_object, source_desc);
200
201         actual_src_desc = source_desc;
202         if (!dest_desc) {
203                 /*
204                  * There is no destination object (An uninitialized node or
205                  * package element), so we can simply copy the source object
206                  * creating a new destination object
207                  */
208                 status =
209                     acpi_ut_copy_iobject_to_iobject(actual_src_desc, new_desc,
210                                                     walk_state);
211                 return_ACPI_STATUS(status);
212         }
213
214         if (source_desc->common.type != dest_desc->common.type) {
215                 /*
216                  * The source type does not match the type of the destination.
217                  * Perform the "implicit conversion" of the source to the current type
218                  * of the target as per the ACPI specification.
219                  *
220                  * If no conversion performed, actual_src_desc = source_desc.
221                  * Otherwise, actual_src_desc is a temporary object to hold the
222                  * converted object.
223                  */
224                 status = acpi_ex_convert_to_target_type(dest_desc->common.type,
225                                                         source_desc,
226                                                         &actual_src_desc,
227                                                         walk_state);
228                 if (ACPI_FAILURE(status)) {
229                         return_ACPI_STATUS(status);
230                 }
231
232                 if (source_desc == actual_src_desc) {
233                         /*
234                          * No conversion was performed. Return the source_desc as the
235                          * new object.
236                          */
237                         *new_desc = source_desc;
238                         return_ACPI_STATUS(AE_OK);
239                 }
240         }
241
242         /*
243          * We now have two objects of identical types, and we can perform a
244          * copy of the *value* of the source object.
245          */
246         switch (dest_desc->common.type) {
247         case ACPI_TYPE_INTEGER:
248
249                 dest_desc->integer.value = actual_src_desc->integer.value;
250
251                 /* Truncate value if we are executing from a 32-bit ACPI table */
252
253                 (void)acpi_ex_truncate_for32bit_table(dest_desc);
254                 break;
255
256         case ACPI_TYPE_STRING:
257
258                 status =
259                     acpi_ex_store_string_to_string(actual_src_desc, dest_desc);
260                 break;
261
262         case ACPI_TYPE_BUFFER:
263
264                 status =
265                     acpi_ex_store_buffer_to_buffer(actual_src_desc, dest_desc);
266                 break;
267
268         case ACPI_TYPE_PACKAGE:
269
270                 status =
271                     acpi_ut_copy_iobject_to_iobject(actual_src_desc, &dest_desc,
272                                                     walk_state);
273                 break;
274
275         default:
276                 /*
277                  * All other types come here.
278                  */
279                 ACPI_WARNING((AE_INFO, "Store into type [%s] not implemented",
280                               acpi_ut_get_object_type_name(dest_desc)));
281
282                 status = AE_NOT_IMPLEMENTED;
283                 break;
284         }
285
286         if (actual_src_desc != source_desc) {
287
288                 /* Delete the intermediate (temporary) source object */
289
290                 acpi_ut_remove_reference(actual_src_desc);
291         }
292
293         *new_desc = dest_desc;
294         return_ACPI_STATUS(status);
295 }