xref: /linux/drivers/acpi/acpica/tbfind.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /******************************************************************************
2  *
3  * Module Name: tbfind   - find table
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, Intel Corp.
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 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "actables.h"
47 
48 #define _COMPONENT          ACPI_TABLES
49 ACPI_MODULE_NAME("tbfind")
50 
51 /*******************************************************************************
52  *
53  * FUNCTION:    acpi_tb_find_table
54  *
55  * PARAMETERS:  signature           - String with ACPI table signature
56  *              oem_id              - String with the table OEM ID
57  *              oem_table_id        - String with the OEM Table ID
58  *              table_index         - Where the table index is returned
59  *
60  * RETURN:      Status and table index
61  *
62  * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
63  *              Signature, OEM ID and OEM Table ID. Returns an index that can
64  *              be used to get the table header or entire table.
65  *
66  ******************************************************************************/
67 acpi_status
68 acpi_tb_find_table(char *signature,
69 		   char *oem_id, char *oem_table_id, u32 *table_index)
70 {
71 	acpi_status status = AE_OK;
72 	struct acpi_table_header header;
73 	u32 i;
74 
75 	ACPI_FUNCTION_TRACE(tb_find_table);
76 
77 	/* Validate the input table signature */
78 
79 	if (!acpi_ut_valid_nameseg(signature)) {
80 		return_ACPI_STATUS(AE_BAD_SIGNATURE);
81 	}
82 
83 	/* Don't allow the OEM strings to be too long */
84 
85 	if ((strlen(oem_id) > ACPI_OEM_ID_SIZE) ||
86 	    (strlen(oem_table_id) > ACPI_OEM_TABLE_ID_SIZE)) {
87 		return_ACPI_STATUS(AE_AML_STRING_LIMIT);
88 	}
89 
90 	/* Normalize the input strings */
91 
92 	memset(&header, 0, sizeof(struct acpi_table_header));
93 	ACPI_MOVE_NAME(header.signature, signature);
94 	strncpy(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
95 	strncpy(header.oem_table_id, oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
96 
97 	/* Search for the table */
98 
99 	(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
100 	for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
101 		if (memcmp(&(acpi_gbl_root_table_list.tables[i].signature),
102 			   header.signature, ACPI_NAME_SIZE)) {
103 
104 			/* Not the requested table */
105 
106 			continue;
107 		}
108 
109 		/* Table with matching signature has been found */
110 
111 		if (!acpi_gbl_root_table_list.tables[i].pointer) {
112 
113 			/* Table is not currently mapped, map it */
114 
115 			status =
116 			    acpi_tb_validate_table(&acpi_gbl_root_table_list.
117 						   tables[i]);
118 			if (ACPI_FAILURE(status)) {
119 				goto unlock_and_exit;
120 			}
121 
122 			if (!acpi_gbl_root_table_list.tables[i].pointer) {
123 				continue;
124 			}
125 		}
126 
127 		/* Check for table match on all IDs */
128 
129 		if (!memcmp
130 		    (acpi_gbl_root_table_list.tables[i].pointer->signature,
131 		     header.signature, ACPI_NAME_SIZE) && (!oem_id[0]
132 							   ||
133 							   !memcmp
134 							   (acpi_gbl_root_table_list.
135 							    tables[i].pointer->
136 							    oem_id,
137 							    header.oem_id,
138 							    ACPI_OEM_ID_SIZE))
139 		    && (!oem_table_id[0]
140 			|| !memcmp(acpi_gbl_root_table_list.tables[i].pointer->
141 				   oem_table_id, header.oem_table_id,
142 				   ACPI_OEM_TABLE_ID_SIZE))) {
143 			*table_index = i;
144 
145 			ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
146 					  "Found table [%4.4s]\n",
147 					  header.signature));
148 			goto unlock_and_exit;
149 		}
150 	}
151 	status = AE_NOT_FOUND;
152 
153 unlock_and_exit:
154 	(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
155 	return_ACPI_STATUS(status);
156 }
157