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