Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
[linux-2.6] / drivers / acpi / executer / exfield.c
1 /******************************************************************************
2  *
3  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2007, 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 #include <acpi/acpi.h>
45 #include <acpi/acdispat.h>
46 #include <acpi/acinterp.h>
47
48 #define _COMPONENT          ACPI_EXECUTER
49 ACPI_MODULE_NAME("exfield")
50
51 /*******************************************************************************
52  *
53  * FUNCTION:    acpi_ex_read_data_from_field
54  *
55  * PARAMETERS:  walk_state          - Current execution state
56  *              obj_desc            - The named field
57  *              ret_buffer_desc     - Where the return data object is stored
58  *
59  * RETURN:      Status
60  *
61  * DESCRIPTION: Read from a named field.  Returns either an Integer or a
62  *              Buffer, depending on the size of the field.
63  *
64  ******************************************************************************/
65 acpi_status
66 acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
67                              union acpi_operand_object *obj_desc,
68                              union acpi_operand_object **ret_buffer_desc)
69 {
70         acpi_status status;
71         union acpi_operand_object *buffer_desc;
72         acpi_size length;
73         void *buffer;
74         u8 locked;
75
76         ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
77
78         /* Parameter validation */
79
80         if (!obj_desc) {
81                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
82         }
83         if (!ret_buffer_desc) {
84                 return_ACPI_STATUS(AE_BAD_PARAMETER);
85         }
86
87         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
88                 /*
89                  * If the buffer_field arguments have not been previously evaluated,
90                  * evaluate them now and save the results.
91                  */
92                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
93                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
94                         if (ACPI_FAILURE(status)) {
95                                 return_ACPI_STATUS(status);
96                         }
97                 }
98         } else
99             if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
100                 && (obj_desc->field.region_obj->region.space_id ==
101                     ACPI_ADR_SPACE_SMBUS)) {
102                 /*
103                  * This is an SMBus read.  We must create a buffer to hold the data
104                  * and directly access the region handler.
105                  */
106                 buffer_desc =
107                     acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
108                 if (!buffer_desc) {
109                         return_ACPI_STATUS(AE_NO_MEMORY);
110                 }
111
112                 /* Lock entire transaction if requested */
113
114                 locked =
115                     acpi_ex_acquire_global_lock(obj_desc->common_field.
116                                                 field_flags);
117
118                 /*
119                  * Perform the read.
120                  * Note: Smbus protocol value is passed in upper 16-bits of Function
121                  */
122                 status = acpi_ex_access_region(obj_desc, 0,
123                                                ACPI_CAST_PTR(acpi_integer,
124                                                              buffer_desc->
125                                                              buffer.pointer),
126                                                ACPI_READ | (obj_desc->field.
127                                                             attribute << 16));
128                 acpi_ex_release_global_lock(locked);
129                 goto exit;
130         }
131
132         /*
133          * Allocate a buffer for the contents of the field.
134          *
135          * If the field is larger than the size of an acpi_integer, create
136          * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
137          * the use of arithmetic operators on the returned value if the
138          * field size is equal or smaller than an Integer.
139          *
140          * Note: Field.length is in bits.
141          */
142         length =
143             (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
144         if (length > acpi_gbl_integer_byte_width) {
145
146                 /* Field is too large for an Integer, create a Buffer instead */
147
148                 buffer_desc = acpi_ut_create_buffer_object(length);
149                 if (!buffer_desc) {
150                         return_ACPI_STATUS(AE_NO_MEMORY);
151                 }
152                 buffer = buffer_desc->buffer.pointer;
153         } else {
154                 /* Field will fit within an Integer (normal case) */
155
156                 buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
157                 if (!buffer_desc) {
158                         return_ACPI_STATUS(AE_NO_MEMORY);
159                 }
160
161                 length = acpi_gbl_integer_byte_width;
162                 buffer_desc->integer.value = 0;
163                 buffer = &buffer_desc->integer.value;
164         }
165
166         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
167                           "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
168                           obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
169                           (u32) length));
170         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
171                           "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
172                           obj_desc->common_field.bit_length,
173                           obj_desc->common_field.start_field_bit_offset,
174                           obj_desc->common_field.base_byte_offset));
175
176         /* Lock entire transaction if requested */
177
178         locked =
179             acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
180
181         /* Read from the field */
182
183         status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
184         acpi_ex_release_global_lock(locked);
185
186       exit:
187         if (ACPI_FAILURE(status)) {
188                 acpi_ut_remove_reference(buffer_desc);
189         } else {
190                 *ret_buffer_desc = buffer_desc;
191         }
192
193         return_ACPI_STATUS(status);
194 }
195
196 /*******************************************************************************
197  *
198  * FUNCTION:    acpi_ex_write_data_to_field
199  *
200  * PARAMETERS:  source_desc         - Contains data to write
201  *              obj_desc            - The named field
202  *              result_desc         - Where the return value is returned, if any
203  *
204  * RETURN:      Status
205  *
206  * DESCRIPTION: Write to a named field
207  *
208  ******************************************************************************/
209
210 acpi_status
211 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
212                             union acpi_operand_object *obj_desc,
213                             union acpi_operand_object **result_desc)
214 {
215         acpi_status status;
216         u32 length;
217         u32 required_length;
218         void *buffer;
219         void *new_buffer;
220         u8 locked;
221         union acpi_operand_object *buffer_desc;
222
223         ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
224
225         /* Parameter validation */
226
227         if (!source_desc || !obj_desc) {
228                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
229         }
230
231         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
232                 /*
233                  * If the buffer_field arguments have not been previously evaluated,
234                  * evaluate them now and save the results.
235                  */
236                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
237                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
238                         if (ACPI_FAILURE(status)) {
239                                 return_ACPI_STATUS(status);
240                         }
241                 }
242         } else
243             if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
244                 && (obj_desc->field.region_obj->region.space_id ==
245                     ACPI_ADR_SPACE_SMBUS)) {
246                 /*
247                  * This is an SMBus write.  We will bypass the entire field mechanism
248                  * and handoff the buffer directly to the handler.
249                  *
250                  * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
251                  */
252                 if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
253                         ACPI_ERROR((AE_INFO,
254                                     "SMBus write requires Buffer, found type %s",
255                                     acpi_ut_get_object_type_name(source_desc)));
256
257                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
258                 }
259
260                 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
261                         ACPI_ERROR((AE_INFO,
262                                     "SMBus write requires Buffer of length %X, found length %X",
263                                     ACPI_SMBUS_BUFFER_SIZE,
264                                     source_desc->buffer.length));
265
266                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
267                 }
268
269                 buffer_desc =
270                     acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
271                 if (!buffer_desc) {
272                         return_ACPI_STATUS(AE_NO_MEMORY);
273                 }
274
275                 buffer = buffer_desc->buffer.pointer;
276                 ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
277                             ACPI_SMBUS_BUFFER_SIZE);
278
279                 /* Lock entire transaction if requested */
280
281                 locked =
282                     acpi_ex_acquire_global_lock(obj_desc->common_field.
283                                                 field_flags);
284
285                 /*
286                  * Perform the write (returns status and perhaps data in the
287                  * same buffer)
288                  * Note: SMBus protocol type is passed in upper 16-bits of Function.
289                  */
290                 status = acpi_ex_access_region(obj_desc, 0,
291                                                (acpi_integer *) buffer,
292                                                ACPI_WRITE | (obj_desc->field.
293                                                              attribute << 16));
294                 acpi_ex_release_global_lock(locked);
295
296                 *result_desc = buffer_desc;
297                 return_ACPI_STATUS(status);
298         }
299
300         /* Get a pointer to the data to be written */
301
302         switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
303         case ACPI_TYPE_INTEGER:
304                 buffer = &source_desc->integer.value;
305                 length = sizeof(source_desc->integer.value);
306                 break;
307
308         case ACPI_TYPE_BUFFER:
309                 buffer = source_desc->buffer.pointer;
310                 length = source_desc->buffer.length;
311                 break;
312
313         case ACPI_TYPE_STRING:
314                 buffer = source_desc->string.pointer;
315                 length = source_desc->string.length;
316                 break;
317
318         default:
319                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
320         }
321
322         /*
323          * We must have a buffer that is at least as long as the field
324          * we are writing to.  This is because individual fields are
325          * indivisible and partial writes are not supported -- as per
326          * the ACPI specification.
327          */
328         new_buffer = NULL;
329         required_length =
330             ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
331
332         if (length < required_length) {
333
334                 /* We need to create a new buffer */
335
336                 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
337                 if (!new_buffer) {
338                         return_ACPI_STATUS(AE_NO_MEMORY);
339                 }
340
341                 /*
342                  * Copy the original data to the new buffer, starting
343                  * at Byte zero.  All unused (upper) bytes of the
344                  * buffer will be 0.
345                  */
346                 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, length);
347                 buffer = new_buffer;
348                 length = required_length;
349         }
350
351         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
352                           "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
353                           source_desc,
354                           acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
355                                                 (source_desc)),
356                           ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));
357
358         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
359                           "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
360                           obj_desc,
361                           acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
362                           ACPI_GET_OBJECT_TYPE(obj_desc),
363                           obj_desc->common_field.bit_length,
364                           obj_desc->common_field.start_field_bit_offset,
365                           obj_desc->common_field.base_byte_offset));
366
367         /* Lock entire transaction if requested */
368
369         locked =
370             acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
371
372         /* Write to the field */
373
374         status = acpi_ex_insert_into_field(obj_desc, buffer, length);
375         acpi_ex_release_global_lock(locked);
376
377         /* Free temporary buffer if we used one */
378
379         if (new_buffer) {
380                 ACPI_FREE(new_buffer);
381         }
382
383         return_ACPI_STATUS(status);
384 }