Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / exnames.c
1
2 /******************************************************************************
3  *
4  * Module Name: exnames - interpreter/scanner name load/execute
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2012, 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 #include "amlcode.h"
49
50 #define _COMPONENT          ACPI_EXECUTER
51 ACPI_MODULE_NAME("exnames")
52
53 /* Local prototypes */
54 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs);
55
56 static acpi_status
57 acpi_ex_name_segment(u8 ** in_aml_address, char *name_string);
58
59 /*******************************************************************************
60  *
61  * FUNCTION:    acpi_ex_allocate_name_string
62  *
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
66  *
67  * RETURN:      A pointer to the allocated string segment.  This segment must
68  *              be deleted by the caller.
69  *
70  * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
71  *              string is long enough, and set up prefix if any.
72  *
73  ******************************************************************************/
74
75 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs)
76 {
77         char *temp_ptr;
78         char *name_string;
79         u32 size_needed;
80
81         ACPI_FUNCTION_TRACE(ex_allocate_name_string);
82
83         /*
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.
87          */
88         if (prefix_count == ACPI_UINT32_MAX) {
89
90                 /* Special case for root */
91
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;
96         }
97
98         /*
99          * Allocate a buffer for the name.
100          * This buffer must be deleted by the caller!
101          */
102         name_string = ACPI_ALLOCATE(size_needed);
103         if (!name_string) {
104                 ACPI_ERROR((AE_INFO,
105                             "Could not allocate size %u", size_needed));
106                 return_PTR(NULL);
107         }
108
109         temp_ptr = name_string;
110
111         /* Set up Root or Parent prefixes if needed */
112
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;
118                 }
119         }
120
121         /* Set up Dual or Multi prefixes if needed */
122
123         if (num_name_segs > 2) {
124
125                 /* Set up multi prefixes   */
126
127                 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
128                 *temp_ptr++ = (char)num_name_segs;
129         } else if (2 == num_name_segs) {
130
131                 /* Set up dual prefixes */
132
133                 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
134         }
135
136         /*
137          * Terminate string following prefixes. acpi_ex_name_segment() will
138          * append the segment(s)
139          */
140         *temp_ptr = 0;
141
142         return_PTR(name_string);
143 }
144
145 /*******************************************************************************
146  *
147  * FUNCTION:    acpi_ex_name_segment
148  *
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
152  *
153  * RETURN:      Status
154  *
155  * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
156  *
157  ******************************************************************************/
158
159 static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
160 {
161         char *aml_address = (void *)*in_aml_address;
162         acpi_status status = AE_OK;
163         u32 index;
164         char char_buf[5];
165
166         ACPI_FUNCTION_TRACE(ex_name_segment);
167
168         /*
169          * If first character is a digit, then we know that we aren't looking at a
170          * valid name segment
171          */
172         char_buf[0] = *aml_address;
173
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);
177         }
178
179         ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "Bytes from stream:\n"));
180
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]));
185         }
186
187         /* Valid name segment  */
188
189         if (index == 4) {
190
191                 /* Found 4 valid characters */
192
193                 char_buf[4] = '\0';
194
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));
202                 }
203         } else if (index == 0) {
204                 /*
205                  * First character was not a valid name character,
206                  * so we are looking at something other than a name.
207                  */
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 {
213                 /*
214                  * Segment started with one or more valid characters, but fewer than
215                  * the required 4
216                  */
217                 status = AE_AML_BAD_NAME;
218                 ACPI_ERROR((AE_INFO,
219                             "Bad character 0x%02x in name, at %p",
220                             *aml_address, aml_address));
221         }
222
223         *in_aml_address = ACPI_CAST_PTR(u8, aml_address);
224         return_ACPI_STATUS(status);
225 }
226
227 /*******************************************************************************
228  *
229  * FUNCTION:    acpi_ex_get_name_string
230  *
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
236  *
237  * RETURN:      Status, namestring and length
238  *
239  * DESCRIPTION: Extract a full namepath from the AML byte stream,
240  *              including any prefixes.
241  *
242  ******************************************************************************/
243
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)
248 {
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;
255
256         ACPI_FUNCTION_TRACE_PTR(ex_get_name_string, aml_address);
257
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) {
261
262                 /* Disallow prefixes for types associated with field_unit names */
263
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);
270                 }
271         } else {
272                 /*
273                  * data_type is not a field name.
274                  * Examine first character of name for root or parent prefix operators
275                  */
276                 switch (*aml_address) {
277                 case AML_ROOT_PREFIX:
278
279                         ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
280                                           "RootPrefix(\\) at %p\n",
281                                           aml_address));
282
283                         /*
284                          * Remember that we have a root_prefix --
285                          * see comment in acpi_ex_allocate_name_string()
286                          */
287                         aml_address++;
288                         prefix_count = ACPI_UINT32_MAX;
289                         has_prefix = TRUE;
290                         break;
291
292                 case AML_PARENT_PREFIX:
293
294                         /* Increment past possibly multiple parent prefixes */
295
296                         do {
297                                 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
298                                                   "ParentPrefix (^) at %p\n",
299                                                   aml_address));
300
301                                 aml_address++;
302                                 prefix_count++;
303
304                         } while (*aml_address == AML_PARENT_PREFIX);
305
306                         has_prefix = TRUE;
307                         break;
308
309                 default:
310
311                         /* Not a prefix character */
312
313                         break;
314                 }
315
316                 /* Examine first character of name for name segment prefix operator */
317
318                 switch (*aml_address) {
319                 case AML_DUAL_NAME_PREFIX:
320
321                         ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
322                                           "DualNamePrefix at %p\n",
323                                           aml_address));
324
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;
331                         }
332
333                         /* Indicate that we processed a prefix */
334
335                         has_prefix = TRUE;
336
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);
343                         }
344                         break;
345
346                 case AML_MULTI_NAME_PREFIX_OP:
347
348                         ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
349                                           "MultiNamePrefix at %p\n",
350                                           aml_address));
351
352                         /* Fetch count of segments remaining in name path */
353
354                         aml_address++;
355                         num_segments = *aml_address;
356
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;
363                         }
364
365                         /* Indicate that we processed a prefix */
366
367                         aml_address++;
368                         has_prefix = TRUE;
369
370                         while (num_segments &&
371                                (status =
372                                 acpi_ex_name_segment(&aml_address,
373                                                      name_string)) == AE_OK) {
374                                 num_segments--;
375                         }
376
377                         break;
378
379                 case 0:
380
381                         /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
382
383                         if (prefix_count == ACPI_UINT32_MAX) {
384                                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
385                                                   "NameSeg is \"\\\" followed by NULL\n"));
386                         }
387
388                         /* Consume the NULL byte */
389
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;
396                         }
397
398                         break;
399
400                 default:
401
402                         /* Name segment string */
403
404                         name_string =
405                             acpi_ex_allocate_name_string(prefix_count, 1);
406                         if (!name_string) {
407                                 status = AE_NO_MEMORY;
408                                 break;
409                         }
410
411                         status =
412                             acpi_ex_name_segment(&aml_address, name_string);
413                         break;
414                 }
415         }
416
417         if (AE_CTRL_PENDING == status && has_prefix) {
418
419                 /* Ran out of segments after processing a prefix */
420
421                 ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
422                 status = AE_AML_BAD_NAME;
423         }
424
425         if (ACPI_FAILURE(status)) {
426                 if (name_string) {
427                         ACPI_FREE(name_string);
428                 }
429                 return_ACPI_STATUS(status);
430         }
431
432         *out_name_string = name_string;
433         *out_name_length = (u32) (aml_address - in_aml_address);
434
435         return_ACPI_STATUS(status);
436 }