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1da177e4 LT |
1 | /****************************************************************************** |
2 | * | |
3 | * Module Name: tbutils - Table manipulation utilities | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
8 | * Copyright (C) 2000 - 2005, R. Byron Moore | |
9 | * All rights reserved. | |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * 1. Redistributions of source code must retain the above copyright | |
15 | * notice, this list of conditions, and the following disclaimer, | |
16 | * without modification. | |
17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer | |
18 | * substantially similar to the "NO WARRANTY" disclaimer below | |
19 | * ("Disclaimer") and any redistribution must be conditioned upon | |
20 | * including a substantially similar Disclaimer requirement for further | |
21 | * binary redistribution. | |
22 | * 3. Neither the names of the above-listed copyright holders nor the names | |
23 | * of any contributors may be used to endorse or promote products derived | |
24 | * from this software without specific prior written permission. | |
25 | * | |
26 | * Alternatively, this software may be distributed under the terms of the | |
27 | * GNU General Public License ("GPL") version 2 as published by the Free | |
28 | * Software Foundation. | |
29 | * | |
30 | * NO WARRANTY | |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR | |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
41 | * POSSIBILITY OF SUCH DAMAGES. | |
42 | */ | |
43 | ||
44 | ||
45 | #include <acpi/acpi.h> | |
46 | #include <acpi/actables.h> | |
47 | ||
48 | ||
49 | #define _COMPONENT ACPI_TABLES | |
50 | ACPI_MODULE_NAME ("tbutils") | |
51 | ||
52 | ||
53 | /******************************************************************************* | |
54 | * | |
55 | * FUNCTION: acpi_tb_handle_to_object | |
56 | * | |
57 | * PARAMETERS: table_id - Id for which the function is searching | |
58 | * table_desc - Pointer to return the matching table | |
59 | * descriptor. | |
60 | * | |
61 | * RETURN: Search the tables to find one with a matching table_id and | |
62 | * return a pointer to that table descriptor. | |
63 | * | |
64 | ******************************************************************************/ | |
65 | #ifdef ACPI_FUTURE_USAGE | |
66 | acpi_status | |
67 | acpi_tb_handle_to_object ( | |
68 | u16 table_id, | |
69 | struct acpi_table_desc **return_table_desc) | |
70 | { | |
71 | u32 i; | |
72 | struct acpi_table_desc *table_desc; | |
73 | ||
74 | ||
75 | ACPI_FUNCTION_NAME ("tb_handle_to_object"); | |
76 | ||
77 | ||
78 | for (i = 0; i < ACPI_TABLE_MAX; i++) { | |
79 | table_desc = acpi_gbl_table_lists[i].next; | |
80 | while (table_desc) { | |
81 | if (table_desc->table_id == table_id) { | |
82 | *return_table_desc = table_desc; | |
83 | return (AE_OK); | |
84 | } | |
85 | ||
86 | table_desc = table_desc->next; | |
87 | } | |
88 | } | |
89 | ||
90 | ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "table_id=%X does not exist\n", table_id)); | |
91 | return (AE_BAD_PARAMETER); | |
92 | } | |
93 | #endif /* ACPI_FUTURE_USAGE */ | |
94 | ||
95 | ||
96 | /******************************************************************************* | |
97 | * | |
98 | * FUNCTION: acpi_tb_validate_table_header | |
99 | * | |
100 | * PARAMETERS: table_header - Logical pointer to the table | |
101 | * | |
102 | * RETURN: Status | |
103 | * | |
104 | * DESCRIPTION: Check an ACPI table header for validity | |
105 | * | |
106 | * NOTE: Table pointers are validated as follows: | |
107 | * 1) Table pointer must point to valid physical memory | |
108 | * 2) Signature must be 4 ASCII chars, even if we don't recognize the | |
109 | * name | |
110 | * 3) Table must be readable for length specified in the header | |
111 | * 4) Table checksum must be valid (with the exception of the FACS | |
112 | * which has no checksum because it contains variable fields) | |
113 | * | |
114 | ******************************************************************************/ | |
115 | ||
116 | acpi_status | |
117 | acpi_tb_validate_table_header ( | |
118 | struct acpi_table_header *table_header) | |
119 | { | |
120 | acpi_name signature; | |
121 | ||
122 | ||
123 | ACPI_FUNCTION_NAME ("tb_validate_table_header"); | |
124 | ||
125 | ||
126 | /* Verify that this is a valid address */ | |
127 | ||
128 | if (!acpi_os_readable (table_header, sizeof (struct acpi_table_header))) { | |
129 | ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, | |
130 | "Cannot read table header at %p\n", table_header)); | |
131 | return (AE_BAD_ADDRESS); | |
132 | } | |
133 | ||
134 | /* Ensure that the signature is 4 ASCII characters */ | |
135 | ||
136 | ACPI_MOVE_32_TO_32 (&signature, table_header->signature); | |
137 | if (!acpi_ut_valid_acpi_name (signature)) { | |
138 | ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, | |
139 | "Table signature at %p [%p] has invalid characters\n", | |
140 | table_header, &signature)); | |
141 | ||
142 | ACPI_REPORT_WARNING (("Invalid table signature found: [%4.4s]\n", | |
143 | (char *) &signature)); | |
144 | ACPI_DUMP_BUFFER (table_header, sizeof (struct acpi_table_header)); | |
145 | return (AE_BAD_SIGNATURE); | |
146 | } | |
147 | ||
148 | /* Validate the table length */ | |
149 | ||
150 | if (table_header->length < sizeof (struct acpi_table_header)) { | |
151 | ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, | |
152 | "Invalid length in table header %p name %4.4s\n", | |
153 | table_header, (char *) &signature)); | |
154 | ||
155 | ACPI_REPORT_WARNING (("Invalid table header length (0x%X) found\n", | |
156 | (u32) table_header->length)); | |
157 | ACPI_DUMP_BUFFER (table_header, sizeof (struct acpi_table_header)); | |
158 | return (AE_BAD_HEADER); | |
159 | } | |
160 | ||
161 | return (AE_OK); | |
162 | } | |
163 | ||
164 | ||
165 | /******************************************************************************* | |
166 | * | |
167 | * FUNCTION: acpi_tb_verify_table_checksum | |
168 | * | |
169 | * PARAMETERS: *table_header - ACPI table to verify | |
170 | * | |
171 | * RETURN: 8 bit checksum of table | |
172 | * | |
173 | * DESCRIPTION: Does an 8 bit checksum of table and returns status. A correct | |
174 | * table should have a checksum of 0. | |
175 | * | |
176 | ******************************************************************************/ | |
177 | ||
178 | acpi_status | |
179 | acpi_tb_verify_table_checksum ( | |
180 | struct acpi_table_header *table_header) | |
181 | { | |
182 | u8 checksum; | |
183 | acpi_status status = AE_OK; | |
184 | ||
185 | ||
186 | ACPI_FUNCTION_TRACE ("tb_verify_table_checksum"); | |
187 | ||
188 | ||
189 | /* Compute the checksum on the table */ | |
190 | ||
191 | checksum = acpi_tb_checksum (table_header, table_header->length); | |
192 | ||
193 | /* Return the appropriate exception */ | |
194 | ||
195 | if (checksum) { | |
196 | ACPI_REPORT_WARNING (("Invalid checksum in table [%4.4s] (%02X, sum %02X is not zero)\n", | |
197 | table_header->signature, (u32) table_header->checksum, (u32) checksum)); | |
198 | ||
199 | status = AE_BAD_CHECKSUM; | |
200 | } | |
201 | return_ACPI_STATUS (status); | |
202 | } | |
203 | ||
204 | ||
205 | /******************************************************************************* | |
206 | * | |
207 | * FUNCTION: acpi_tb_checksum | |
208 | * | |
209 | * PARAMETERS: Buffer - Buffer to checksum | |
210 | * Length - Size of the buffer | |
211 | * | |
212 | * RETURNS 8 bit checksum of buffer | |
213 | * | |
214 | * DESCRIPTION: Computes an 8 bit checksum of the buffer(length) and returns it. | |
215 | * | |
216 | ******************************************************************************/ | |
217 | ||
218 | u8 | |
219 | acpi_tb_checksum ( | |
220 | void *buffer, | |
221 | u32 length) | |
222 | { | |
223 | const u8 *limit; | |
224 | const u8 *rover; | |
225 | u8 sum = 0; | |
226 | ||
227 | ||
228 | if (buffer && length) { | |
229 | /* Buffer and Length are valid */ | |
230 | ||
231 | limit = (u8 *) buffer + length; | |
232 | ||
233 | for (rover = buffer; rover < limit; rover++) { | |
234 | sum = (u8) (sum + *rover); | |
235 | } | |
236 | } | |
237 | return (sum); | |
238 | } | |
239 | ||
240 |