summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/tables/tbutils.c
blob: d89b1508cece2cd80e1f06df8a75cdd1b3b557ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
/******************************************************************************
 *
 * Module Name: tbutils - Table manipulation utilities
 *              $Revision: 33 $
 *
 *****************************************************************************/

/*
 *  Copyright (C) 2000, 2001 R. Byron Moore
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "acpi.h"
#include "actables.h"
#include "acinterp.h"


#define _COMPONENT          TABLE_MANAGER
	 MODULE_NAME         ("tbutils")


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_handle_to_object
 *
 * PARAMETERS:  Table_id            - Id for which the function is searching
 *              Table_desc          - Pointer to return the matching table
 *                                      descriptor.
 *
 * RETURN:      Search the tables to find one with a matching Table_id and
 *              return a pointer to that table descriptor.
 *
 ******************************************************************************/

ACPI_STATUS
acpi_tb_handle_to_object (
	u16                     table_id,
	ACPI_TABLE_DESC         **table_desc)
{
	u32                     i;
	ACPI_TABLE_DESC         *list_head;


	for (i = 0; i < ACPI_TABLE_MAX; i++) {
		list_head = &acpi_gbl_acpi_tables[i];
		do
		{
			if (list_head->table_id == table_id) {
				*table_desc = list_head;
				return (AE_OK);
			}

			list_head = list_head->next;

		} while (list_head != &acpi_gbl_acpi_tables[i]);
	}


	return (AE_BAD_PARAMETER);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_system_table_pointer
 *
 * PARAMETERS:  *Where              - Pointer to be examined
 *
 * RETURN:      TRUE if Where is within the AML stream (in one of the ACPI
 *              system tables such as the DSDT or an SSDT.)
 *              FALSE otherwise
 *
 ******************************************************************************/

u8
acpi_tb_system_table_pointer (
	void                    *where)
{
	u32                     i;
	ACPI_TABLE_DESC         *table_desc;
	ACPI_TABLE_HEADER       *table;


	/* No function trace, called too often! */


	/* Ignore null pointer */

	if (!where) {
		return (FALSE);
	}


	/* Check for a pointer within the DSDT */

	if ((acpi_gbl_DSDT) &&
		(IS_IN_ACPI_TABLE (where, acpi_gbl_DSDT)))
	{
		return (TRUE);
	}


	/* Check each of the loaded SSDTs (if any)*/

	table_desc = &acpi_gbl_acpi_tables[ACPI_TABLE_SSDT];

	for (i = 0; i < acpi_gbl_acpi_tables[ACPI_TABLE_SSDT].count; i++) {
		table = table_desc->pointer;

		if (IS_IN_ACPI_TABLE (where, table)) {
			return (TRUE);
		}

		table_desc = table_desc->next;
	}


	/* Check each of the loaded PSDTs (if any)*/

	table_desc = &acpi_gbl_acpi_tables[ACPI_TABLE_PSDT];

	for (i = 0; i < acpi_gbl_acpi_tables[ACPI_TABLE_PSDT].count; i++) {
		table = table_desc->pointer;

		if (IS_IN_ACPI_TABLE (where, table)) {
			return (TRUE);
		}

		table_desc = table_desc->next;
	}


	/* Pointer does not point into any system table */

	return (FALSE);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_validate_table_header
 *
 * PARAMETERS:  Table_header        - Logical pointer to the table
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Check an ACPI table header for validity
 *
 * NOTE:  Table pointers are validated as follows:
 *          1) Table pointer must point to valid physical memory
 *          2) Signature must be 4 ASCII chars, even if we don't recognize the
 *             name
 *          3) Table must be readable for length specified in the header
 *          4) Table checksum must be valid (with the exception of the FACS
 *              which has no checksum for some odd reason)
 *
 ******************************************************************************/

ACPI_STATUS
acpi_tb_validate_table_header (
	ACPI_TABLE_HEADER       *table_header)
{
	ACPI_NAME               signature;


	/* Verify that this is a valid address */

	if (!acpi_os_readable (table_header, sizeof (ACPI_TABLE_HEADER))) {
		return (AE_BAD_ADDRESS);
	}


	/* Ensure that the signature is 4 ASCII characters */

	MOVE_UNALIGNED32_TO_32 (&signature, &table_header->signature);
	if (!acpi_cm_valid_acpi_name (signature)) {
		REPORT_WARNING (("Invalid table signature found\n"));
		return (AE_BAD_SIGNATURE);
	}


	/* Validate the table length */

	if (table_header->length < sizeof (ACPI_TABLE_HEADER)) {
		REPORT_WARNING (("Invalid table header length found\n"));
		return (AE_BAD_HEADER);
	}

	return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_map_acpi_table
 *
 * PARAMETERS:  Physical_address        - Physical address of table to map
 *              *Size                   - Size of the table.  If zero, the size
 *                                        from the table header is used.
 *                                        Actual size is returned here.
 *              **Logical_address       - Logical address of mapped table
 *
 * RETURN:      Logical address of the mapped table.
 *
 * DESCRIPTION: Maps the physical address of table into a logical address
 *
 ******************************************************************************/

ACPI_STATUS
acpi_tb_map_acpi_table (
	ACPI_PHYSICAL_ADDRESS   physical_address,
	u32                     *size,
	void                    **logical_address)
{
	ACPI_TABLE_HEADER       *table;
	u32                     table_size = *size;
	ACPI_STATUS             status = AE_OK;


	/* If size is zero, look at the table header to get the actual size */

	if ((*size) == 0) {
		/* Get the table header so we can extract the table length */

		status = acpi_os_map_memory (physical_address, sizeof (ACPI_TABLE_HEADER),
				  (void **) &table);
		if (ACPI_FAILURE (status)) {
			return (status);
		}

		/* Extract the full table length before we delete the mapping */

		table_size = table->length;

		/*
		 * Validate the header and delete the mapping.
		 * We will create a mapping for the full table below.
		 */

		status = acpi_tb_validate_table_header (table);

		/* Always unmap the memory for the header */

		acpi_os_unmap_memory (table, sizeof (ACPI_TABLE_HEADER));

		/* Exit if header invalid */

		if (ACPI_FAILURE (status)) {
			return (status);
		}
	}


	/* Map the physical memory for the correct length */

	status = acpi_os_map_memory (physical_address, table_size, (void **) &table);
	if (ACPI_FAILURE (status)) {
		return (status);
	}

	*size = table_size;
	*logical_address = table;

	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_verify_table_checksum
 *
 * PARAMETERS:  *Table_header           - ACPI table to verify
 *
 * RETURN:      8 bit checksum of table
 *
 * DESCRIPTION: Does an 8 bit checksum of table and returns status.  A correct
 *              table should have a checksum of 0.
 *
 ******************************************************************************/

ACPI_STATUS
acpi_tb_verify_table_checksum (
	ACPI_TABLE_HEADER       *table_header)
{
	u8                      checksum;
	ACPI_STATUS             status = AE_OK;


	/* Compute the checksum on the table */

	checksum = acpi_tb_checksum (table_header, table_header->length);

	/* Return the appropriate exception */

	if (checksum) {
		REPORT_WARNING (("Invalid checksum (%X) in table %4.4s\n",
			checksum, &table_header->signature));

		status = AE_BAD_CHECKSUM;
	}


	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_tb_checksum
 *
 * PARAMETERS:  Buffer              - Buffer to checksum
 *              Length              - Size of the buffer
 *
 * RETURNS      8 bit checksum of buffer
 *
 * DESCRIPTION: Computes an 8 bit checksum of the buffer(length) and returns it.
 *
 ******************************************************************************/

u8
acpi_tb_checksum (
	void                    *buffer,
	u32                     length)
{
	u8                      *limit;
	u8                      *rover;
	u8                      sum = 0;


	if (buffer && length) {
		/*  Buffer and Length are valid   */

		limit = (u8 *) buffer + length;

		for (rover = buffer; rover < limit; rover++) {
			sum = (u8) (sum + *rover);
		}
	}

	return (sum);
}