Linux 2.6.33-rc8
[linux-2.6/lguest.git] / drivers / acpi / acpica / exnames.c
blobffdae122d94af6e365aca484d95678b77d81e759
2 /******************************************************************************
4 * Module Name: exnames - interpreter/scanner name load/execute
6 *****************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2008, Intel Corp.
10 * All rights reserved.
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.
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.
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.
45 #include <acpi/acpi.h>
46 #include "accommon.h"
47 #include "acinterp.h"
48 #include "amlcode.h"
50 #define _COMPONENT ACPI_EXECUTER
51 ACPI_MODULE_NAME("exnames")
53 /* Local prototypes */
54 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs);
56 static acpi_status
57 acpi_ex_name_segment(u8 ** in_aml_address, char *name_string);
59 /*******************************************************************************
61 * FUNCTION: acpi_ex_allocate_name_string
63 * PARAMETERS: prefix_count - Count of parent levels. Special cases:
64 * (-1)==root, 0==none
65 * num_name_segs - count of 4-character name segments
67 * RETURN: A pointer to the allocated string segment. This segment must
68 * be deleted by the caller.
70 * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
71 * string is long enough, and set up prefix if any.
73 ******************************************************************************/
75 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs)
77 char *temp_ptr;
78 char *name_string;
79 u32 size_needed;
81 ACPI_FUNCTION_TRACE(ex_allocate_name_string);
84 * Allow room for all \ and ^ prefixes, all segments and a multi_name_prefix.
85 * Also, one byte for the null terminator.
86 * This may actually be somewhat longer than needed.
88 if (prefix_count == ACPI_UINT32_MAX) {
90 /* Special case for root */
92 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
93 } else {
94 size_needed =
95 prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
99 * Allocate a buffer for the name.
100 * This buffer must be deleted by the caller!
102 name_string = ACPI_ALLOCATE(size_needed);
103 if (!name_string) {
104 ACPI_ERROR((AE_INFO,
105 "Could not allocate size %d", size_needed));
106 return_PTR(NULL);
109 temp_ptr = name_string;
111 /* Set up Root or Parent prefixes if needed */
113 if (prefix_count == ACPI_UINT32_MAX) {
114 *temp_ptr++ = AML_ROOT_PREFIX;
115 } else {
116 while (prefix_count--) {
117 *temp_ptr++ = AML_PARENT_PREFIX;
121 /* Set up Dual or Multi prefixes if needed */
123 if (num_name_segs > 2) {
125 /* Set up multi prefixes */
127 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
128 *temp_ptr++ = (char)num_name_segs;
129 } else if (2 == num_name_segs) {
131 /* Set up dual prefixes */
133 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
137 * Terminate string following prefixes. acpi_ex_name_segment() will
138 * append the segment(s)
140 *temp_ptr = 0;
142 return_PTR(name_string);
145 /*******************************************************************************
147 * FUNCTION: acpi_ex_name_segment
149 * PARAMETERS: in_aml_address - Pointer to the name in the AML code
150 * name_string - Where to return the name. The name is appended
151 * to any existing string to form a namepath
153 * RETURN: Status
155 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
157 ******************************************************************************/
159 static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
161 char *aml_address = (void *)*in_aml_address;
162 acpi_status status = AE_OK;
163 u32 index;
164 char char_buf[5];
166 ACPI_FUNCTION_TRACE(ex_name_segment);
169 * If first character is a digit, then we know that we aren't looking at a
170 * valid name segment
172 char_buf[0] = *aml_address;
174 if ('0' <= char_buf[0] && char_buf[0] <= '9') {
175 ACPI_ERROR((AE_INFO, "Invalid leading digit: %c", char_buf[0]));
176 return_ACPI_STATUS(AE_CTRL_PENDING);
179 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "Bytes from stream:\n"));
181 for (index = 0; (index < ACPI_NAME_SIZE)
182 && (acpi_ut_valid_acpi_char(*aml_address, 0)); index++) {
183 char_buf[index] = *aml_address++;
184 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "%c\n", char_buf[index]));
187 /* Valid name segment */
189 if (index == 4) {
191 /* Found 4 valid characters */
193 char_buf[4] = '\0';
195 if (name_string) {
196 ACPI_STRCAT(name_string, char_buf);
197 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
198 "Appended to - %s\n", name_string));
199 } else {
200 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
201 "No Name string - %s\n", char_buf));
203 } else if (index == 0) {
205 * First character was not a valid name character,
206 * so we are looking at something other than a name.
208 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
209 "Leading character is not alpha: %02Xh (not a name)\n",
210 char_buf[0]));
211 status = AE_CTRL_PENDING;
212 } else {
214 * Segment started with one or more valid characters, but fewer than
215 * the required 4
217 status = AE_AML_BAD_NAME;
218 ACPI_ERROR((AE_INFO,
219 "Bad character %02x in name, at %p",
220 *aml_address, aml_address));
223 *in_aml_address = ACPI_CAST_PTR(u8, aml_address);
224 return_ACPI_STATUS(status);
227 /*******************************************************************************
229 * FUNCTION: acpi_ex_get_name_string
231 * PARAMETERS: data_type - Object type to be associated with this
232 * name
233 * in_aml_address - Pointer to the namestring in the AML code
234 * out_name_string - Where the namestring is returned
235 * out_name_length - Length of the returned string
237 * RETURN: Status, namestring and length
239 * DESCRIPTION: Extract a full namepath from the AML byte stream,
240 * including any prefixes.
242 ******************************************************************************/
244 acpi_status
245 acpi_ex_get_name_string(acpi_object_type data_type,
246 u8 * in_aml_address,
247 char **out_name_string, u32 * out_name_length)
249 acpi_status status = AE_OK;
250 u8 *aml_address = in_aml_address;
251 char *name_string = NULL;
252 u32 num_segments;
253 u32 prefix_count = 0;
254 u8 has_prefix = FALSE;
256 ACPI_FUNCTION_TRACE_PTR(ex_get_name_string, aml_address);
258 if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type ||
259 ACPI_TYPE_LOCAL_BANK_FIELD == data_type ||
260 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
262 /* Disallow prefixes for types associated with field_unit names */
264 name_string = acpi_ex_allocate_name_string(0, 1);
265 if (!name_string) {
266 status = AE_NO_MEMORY;
267 } else {
268 status =
269 acpi_ex_name_segment(&aml_address, name_string);
271 } else {
273 * data_type is not a field name.
274 * Examine first character of name for root or parent prefix operators
276 switch (*aml_address) {
277 case AML_ROOT_PREFIX:
279 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
280 "RootPrefix(\\) at %p\n",
281 aml_address));
284 * Remember that we have a root_prefix --
285 * see comment in acpi_ex_allocate_name_string()
287 aml_address++;
288 prefix_count = ACPI_UINT32_MAX;
289 has_prefix = TRUE;
290 break;
292 case AML_PARENT_PREFIX:
294 /* Increment past possibly multiple parent prefixes */
296 do {
297 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
298 "ParentPrefix (^) at %p\n",
299 aml_address));
301 aml_address++;
302 prefix_count++;
304 } while (*aml_address == AML_PARENT_PREFIX);
306 has_prefix = TRUE;
307 break;
309 default:
311 /* Not a prefix character */
313 break;
316 /* Examine first character of name for name segment prefix operator */
318 switch (*aml_address) {
319 case AML_DUAL_NAME_PREFIX:
321 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
322 "DualNamePrefix at %p\n",
323 aml_address));
325 aml_address++;
326 name_string =
327 acpi_ex_allocate_name_string(prefix_count, 2);
328 if (!name_string) {
329 status = AE_NO_MEMORY;
330 break;
333 /* Indicate that we processed a prefix */
335 has_prefix = TRUE;
337 status =
338 acpi_ex_name_segment(&aml_address, name_string);
339 if (ACPI_SUCCESS(status)) {
340 status =
341 acpi_ex_name_segment(&aml_address,
342 name_string);
344 break;
346 case AML_MULTI_NAME_PREFIX_OP:
348 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
349 "MultiNamePrefix at %p\n",
350 aml_address));
352 /* Fetch count of segments remaining in name path */
354 aml_address++;
355 num_segments = *aml_address;
357 name_string =
358 acpi_ex_allocate_name_string(prefix_count,
359 num_segments);
360 if (!name_string) {
361 status = AE_NO_MEMORY;
362 break;
365 /* Indicate that we processed a prefix */
367 aml_address++;
368 has_prefix = TRUE;
370 while (num_segments &&
371 (status =
372 acpi_ex_name_segment(&aml_address,
373 name_string)) == AE_OK) {
374 num_segments--;
377 break;
379 case 0:
381 /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
383 if (prefix_count == ACPI_UINT32_MAX) {
384 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
385 "NameSeg is \"\\\" followed by NULL\n"));
388 /* Consume the NULL byte */
390 aml_address++;
391 name_string =
392 acpi_ex_allocate_name_string(prefix_count, 0);
393 if (!name_string) {
394 status = AE_NO_MEMORY;
395 break;
398 break;
400 default:
402 /* Name segment string */
404 name_string =
405 acpi_ex_allocate_name_string(prefix_count, 1);
406 if (!name_string) {
407 status = AE_NO_MEMORY;
408 break;
411 status =
412 acpi_ex_name_segment(&aml_address, name_string);
413 break;
417 if (AE_CTRL_PENDING == status && has_prefix) {
419 /* Ran out of segments after processing a prefix */
421 ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
422 status = AE_AML_BAD_NAME;
425 if (ACPI_FAILURE(status)) {
426 if (name_string) {
427 ACPI_FREE(name_string);
429 return_ACPI_STATUS(status);
432 *out_name_string = name_string;
433 *out_name_length = (u32) (aml_address - in_aml_address);
435 return_ACPI_STATUS(status);