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 }