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 - 2005, 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
  45 #include <acpi/acpi.h>
  46 #include <acpi/acdispat.h>
  47 #include <acpi/acinterp.h>
  48
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51          ACPI_MODULE_NAME    ("exfield")
  52
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ex_read_data_from_field
  57  *
  58  * PARAMETERS:  walk_state          - Current execution state
  59  *              obj_desc            - The named field
  60  *              ret_buffer_desc     - Where the return data object is stored
  61  *
  62  * RETURN:      Status
  63  *
  64  * DESCRIPTION: Read from a named field.  Returns either an Integer or a
  65  *              Buffer, depending on the size of the field.
  66  *
  67  ******************************************************************************/
  68
  69 acpi_status
  70 acpi_ex_read_data_from_field (
  71         struct acpi_walk_state          *walk_state,
  72         union acpi_operand_object       *obj_desc,
  73         union acpi_operand_object       **ret_buffer_desc)
  74 {
  75         acpi_status                     status;
  76         union acpi_operand_object       *buffer_desc;
  77         acpi_size                       length;
  78         void                            *buffer;
  79         u8                              locked;
  80
  81
  82         ACPI_FUNCTION_TRACE_PTR ("ex_read_data_from_field", obj_desc);
  83
  84
  85         /* Parameter validation */
  86
  87         if (!obj_desc) {
  88                 return_ACPI_STATUS (AE_AML_NO_OPERAND);
  89         }
  90         if (!ret_buffer_desc) {
  91                 return_ACPI_STATUS (AE_BAD_PARAMETER);
  92         }
  93
  94         if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
  95                 /*
  96                  * If the buffer_field arguments have not been previously evaluated,
  97                  * evaluate them now and save the results.
  98                  */
  99                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 100                         status = acpi_ds_get_buffer_field_arguments (obj_desc);
 101                         if (ACPI_FAILURE (status)) {
 102                                 return_ACPI_STATUS (status);
 103                         }
 104                 }
 105         }
 106         else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 107                          (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
 108                 /*
 109                  * This is an SMBus read.  We must create a buffer to hold the data
 110                  * and directly access the region handler.
 111                  */
 112                 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
 113                 if (!buffer_desc) {
 114                         return_ACPI_STATUS (AE_NO_MEMORY);
 115                 }
 116
 117                 /* Lock entire transaction if requested */
 118
 119                 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 120
 121                 /*
 122                  * Perform the read.
 123                  * Note: Smbus protocol value is passed in upper 16-bits of Function
 124                  */
 125                 status = acpi_ex_access_region (obj_desc, 0,
 126                                  ACPI_CAST_PTR (acpi_integer, buffer_desc->buffer.pointer),
 127                                  ACPI_READ | (obj_desc->field.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 = (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES (obj_desc->field.bit_length);
 143         if (length > acpi_gbl_integer_byte_width) {
 144                 /* Field is too large for an Integer, create a Buffer instead */
 145
 146                 buffer_desc = acpi_ut_create_buffer_object (length);
 147                 if (!buffer_desc) {
 148                         return_ACPI_STATUS (AE_NO_MEMORY);
 149                 }
 150                 buffer = buffer_desc->buffer.pointer;
 151         }
 152         else {
 153                 /* Field will fit within an Integer (normal case) */
 154
 155                 buffer_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 156                 if (!buffer_desc) {
 157                         return_ACPI_STATUS (AE_NO_MEMORY);
 158                 }
 159
 160                 length = acpi_gbl_integer_byte_width;
 161                 buffer_desc->integer.value = 0;
 162                 buffer = &buffer_desc->integer.value;
 163         }
 164
 165         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 166                 "field_read [TO]:  Obj %p, Type %X, Buf %p, byte_len %X\n",
 167                 obj_desc, ACPI_GET_OBJECT_TYPE (obj_desc), buffer, (u32) length));
 168         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 169                 "field_read [FROM]: bit_len %X, bit_off %X, byte_off %X\n",
 170                 obj_desc->common_field.bit_length,
 171                 obj_desc->common_field.start_field_bit_offset,
 172                 obj_desc->common_field.base_byte_offset));
 173
 174         /* Lock entire transaction if requested */
 175
 176         locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 177
 178         /* Read from the field */
 179
 180         status = acpi_ex_extract_from_field (obj_desc, buffer, (u32) length);
 181         acpi_ex_release_global_lock (locked);
 182
 183
 184 exit:
 185         if (ACPI_FAILURE (status)) {
 186                 acpi_ut_remove_reference (buffer_desc);
 187         }
 188         else {
 189                 *ret_buffer_desc = buffer_desc;
 190         }
 191
 192         return_ACPI_STATUS (status);
 193 }
 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 (
 212         union acpi_operand_object       *source_desc,
 213         union acpi_operand_object       *obj_desc,
 214         union acpi_operand_object       **result_desc)
 215 {
 216         acpi_status                     status;
 217         u32                             length;
 218         u32                             required_length;
 219         void                            *buffer;
 220         void                            *new_buffer;
 221         u8                              locked;
 222         union acpi_operand_object       *buffer_desc;
 223
 224
 225         ACPI_FUNCTION_TRACE_PTR ("ex_write_data_to_field", obj_desc);
 226
 227
 228         /* Parameter validation */
 229
 230         if (!source_desc || !obj_desc) {
 231                 return_ACPI_STATUS (AE_AML_NO_OPERAND);
 232         }
 233
 234         if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
 235                 /*
 236                  * If the buffer_field arguments have not been previously evaluated,
 237                  * evaluate them now and save the results.
 238                  */
 239                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 240                         status = acpi_ds_get_buffer_field_arguments (obj_desc);
 241                         if (ACPI_FAILURE (status)) {
 242                                 return_ACPI_STATUS (status);
 243                         }
 244                 }
 245         }
 246         else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 247                          (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
 248                 /*
 249                  * This is an SMBus write.  We will bypass the entire field mechanism
 250                  * and handoff the buffer directly to the handler.
 251                  *
 252                  * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
 253                  */
 254                 if (ACPI_GET_OBJECT_TYPE (source_desc) != ACPI_TYPE_BUFFER) {
 255                         ACPI_REPORT_ERROR (("SMBus write requires Buffer, found type %s\n",
 256                                 acpi_ut_get_object_type_name (source_desc)));
 257
 258                         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
 259                 }
 260
 261                 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
 262                         ACPI_REPORT_ERROR ((
 263                                 "SMBus write requires Buffer of length %X, found length %X\n",
 264                                 ACPI_SMBUS_BUFFER_SIZE, source_desc->buffer.length));
 265
 266                         return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
 267                 }
 268
 269                 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
 270                 if (!buffer_desc) {
 271                         return_ACPI_STATUS (AE_NO_MEMORY);
 272                 }
 273
 274                 buffer = buffer_desc->buffer.pointer;
 275                 ACPI_MEMCPY (buffer, source_desc->buffer.pointer,
 276                         ACPI_SMBUS_BUFFER_SIZE);
 277
 278                 /* Lock entire transaction if requested */
 279
 280                 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 281
 282                 /*
 283                  * Perform the write (returns status and perhaps data in the
 284                  * same buffer)
 285                  * Note: SMBus protocol type is passed in upper 16-bits of Function.
 286                  */
 287                 status = acpi_ex_access_region (obj_desc, 0,
 288                                   (acpi_integer *) buffer,
 289                                   ACPI_WRITE | (obj_desc->field.attribute << 16));
 290                 acpi_ex_release_global_lock (locked);
 291
 292                 *result_desc = buffer_desc;
 293                 return_ACPI_STATUS (status);
 294         }
 295
 296         /* Get a pointer to the data to be written */
 297
 298         switch (ACPI_GET_OBJECT_TYPE (source_desc)) {
 299         case ACPI_TYPE_INTEGER:
 300                 buffer = &source_desc->integer.value;
 301                 length = sizeof (source_desc->integer.value);
 302                 break;
 303
 304         case ACPI_TYPE_BUFFER:
 305                 buffer = source_desc->buffer.pointer;
 306                 length = source_desc->buffer.length;
 307                 break;
 308
 309         case ACPI_TYPE_STRING:
 310                 buffer = source_desc->string.pointer;
 311                 length = source_desc->string.length;
 312                 break;
 313
 314         default:
 315                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
 316         }
 317
 318         /*
 319          * We must have a buffer that is at least as long as the field
 320          * we are writing to.  This is because individual fields are
 321          * indivisible and partial writes are not supported -- as per
 322          * the ACPI specification.
 323          */
 324         new_buffer = NULL;
 325         required_length = ACPI_ROUND_BITS_UP_TO_BYTES (
 326                            obj_desc->common_field.bit_length);
 327
 328         if (length < required_length) {
 329                 /* We need to create a new buffer */
 330
 331                 new_buffer = ACPI_MEM_CALLOCATE (required_length);
 332                 if (!new_buffer) {
 333                         return_ACPI_STATUS (AE_NO_MEMORY);
 334                 }
 335
 336                 /*
 337                  * Copy the original data to the new buffer, starting
 338                  * at Byte zero.  All unused (upper) bytes of the
 339                  * buffer will be 0.
 340                  */
 341                 ACPI_MEMCPY ((char *) new_buffer, (char *) buffer, length);
 342                 buffer = new_buffer;
 343                 length = required_length;
 344         }
 345
 346         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 347                 "field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %X\n",
 348                 source_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (source_desc)),
 349                 ACPI_GET_OBJECT_TYPE (source_desc), buffer, length));
 350
 351         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 352                 "field_write [TO]:  Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %X\n",
 353                 obj_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (obj_desc)),
 354                 ACPI_GET_OBJECT_TYPE (obj_desc),
 355                 obj_desc->common_field.bit_length,
 356                 obj_desc->common_field.start_field_bit_offset,
 357                 obj_desc->common_field.base_byte_offset));
 358
 359         /* Lock entire transaction if requested */
 360
 361         locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 362
 363         /* Write to the field */
 364
 365         status = acpi_ex_insert_into_field (obj_desc, buffer, length);
 366         acpi_ex_release_global_lock (locked);
 367
 368         /* Free temporary buffer if we used one */
 369
 370         if (new_buffer) {
 371                 ACPI_MEM_FREE (new_buffer);
 372         }
 373
 374         return_ACPI_STATUS (status);
 375 }
 376
 377