xref: /openbmc/linux/drivers/acpi/acpica/exstorob.c (revision b627b4ed)
1 
2 /******************************************************************************
3  *
4  * Module Name: exstorob - AML Interpreter object store support, store to object
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2008, 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 
49 #define _COMPONENT          ACPI_EXECUTER
50 ACPI_MODULE_NAME("exstorob")
51 
52 /*******************************************************************************
53  *
54  * FUNCTION:    acpi_ex_store_buffer_to_buffer
55  *
56  * PARAMETERS:  source_desc         - Source object to copy
57  *              target_desc         - Destination object of the copy
58  *
59  * RETURN:      Status
60  *
61  * DESCRIPTION: Copy a buffer object to another buffer object.
62  *
63  ******************************************************************************/
64 acpi_status
65 acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
66 			       union acpi_operand_object *target_desc)
67 {
68 	u32 length;
69 	u8 *buffer;
70 
71 	ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
72 
73 	/* We know that source_desc is a buffer by now */
74 
75 	buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
76 	length = source_desc->buffer.length;
77 
78 	/*
79 	 * If target is a buffer of length zero or is a static buffer,
80 	 * allocate a new buffer of the proper length
81 	 */
82 	if ((target_desc->buffer.length == 0) ||
83 	    (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
84 		target_desc->buffer.pointer = ACPI_ALLOCATE(length);
85 		if (!target_desc->buffer.pointer) {
86 			return_ACPI_STATUS(AE_NO_MEMORY);
87 		}
88 
89 		target_desc->buffer.length = length;
90 	}
91 
92 	/* Copy source buffer to target buffer */
93 
94 	if (length <= target_desc->buffer.length) {
95 
96 		/* Clear existing buffer and copy in the new one */
97 
98 		ACPI_MEMSET(target_desc->buffer.pointer, 0,
99 			    target_desc->buffer.length);
100 		ACPI_MEMCPY(target_desc->buffer.pointer, buffer, length);
101 
102 #ifdef ACPI_OBSOLETE_BEHAVIOR
103 		/*
104 		 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
105 		 * truncated if the string is smaller than the buffer.  However, "other"
106 		 * implementations of ACPI never did this and thus became the defacto
107 		 * standard. ACPI 3.0_a changes this behavior such that the buffer
108 		 * is no longer truncated.
109 		 */
110 
111 		/*
112 		 * OBSOLETE BEHAVIOR:
113 		 * If the original source was a string, we must truncate the buffer,
114 		 * according to the ACPI spec.  Integer-to-Buffer and Buffer-to-Buffer
115 		 * copy must not truncate the original buffer.
116 		 */
117 		if (original_src_type == ACPI_TYPE_STRING) {
118 
119 			/* Set the new length of the target */
120 
121 			target_desc->buffer.length = length;
122 		}
123 #endif
124 	} else {
125 		/* Truncate the source, copy only what will fit */
126 
127 		ACPI_MEMCPY(target_desc->buffer.pointer, buffer,
128 			    target_desc->buffer.length);
129 
130 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
131 				  "Truncating source buffer from %X to %X\n",
132 				  length, target_desc->buffer.length));
133 	}
134 
135 	/* Copy flags */
136 
137 	target_desc->buffer.flags = source_desc->buffer.flags;
138 	target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
139 	return_ACPI_STATUS(AE_OK);
140 }
141 
142 /*******************************************************************************
143  *
144  * FUNCTION:    acpi_ex_store_string_to_string
145  *
146  * PARAMETERS:  source_desc         - Source object to copy
147  *              target_desc         - Destination object of the copy
148  *
149  * RETURN:      Status
150  *
151  * DESCRIPTION: Copy a String object to another String object
152  *
153  ******************************************************************************/
154 
155 acpi_status
156 acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
157 			       union acpi_operand_object *target_desc)
158 {
159 	u32 length;
160 	u8 *buffer;
161 
162 	ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
163 
164 	/* We know that source_desc is a string by now */
165 
166 	buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
167 	length = source_desc->string.length;
168 
169 	/*
170 	 * Replace existing string value if it will fit and the string
171 	 * pointer is not a static pointer (part of an ACPI table)
172 	 */
173 	if ((length < target_desc->string.length) &&
174 	    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
175 		/*
176 		 * String will fit in existing non-static buffer.
177 		 * Clear old string and copy in the new one
178 		 */
179 		ACPI_MEMSET(target_desc->string.pointer, 0,
180 			    (acpi_size) target_desc->string.length + 1);
181 		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
182 	} else {
183 		/*
184 		 * Free the current buffer, then allocate a new buffer
185 		 * large enough to hold the value
186 		 */
187 		if (target_desc->string.pointer &&
188 		    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
189 
190 			/* Only free if not a pointer into the DSDT */
191 
192 			ACPI_FREE(target_desc->string.pointer);
193 		}
194 
195 		target_desc->string.pointer = ACPI_ALLOCATE_ZEROED((acpi_size)
196 								   length + 1);
197 		if (!target_desc->string.pointer) {
198 			return_ACPI_STATUS(AE_NO_MEMORY);
199 		}
200 
201 		target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
202 		ACPI_MEMCPY(target_desc->string.pointer, buffer, length);
203 	}
204 
205 	/* Set the new target length */
206 
207 	target_desc->string.length = length;
208 	return_ACPI_STATUS(AE_OK);
209 }
210