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
  91         if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
  92                 /*
  93                  * If the buffer_field arguments have not been previously evaluated,
  94                  * evaluate them now and save the results.
  95                  */
  96                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
  97                         status = acpi_ds_get_buffer_field_arguments (obj_desc);
  98                         if (ACPI_FAILURE (status)) {
  99                                 return_ACPI_STATUS (status);
 100                         }
 101                 }
 102         }
 103         else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 104                          (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
 105                 /*
 106                  * This is an SMBus read.  We must create a buffer to hold the data
 107                  * and directly access the region handler.
 108                  */
 109                 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
 110                 if (!buffer_desc) {
 111                         return_ACPI_STATUS (AE_NO_MEMORY);
 112                 }
 113
 114                 /* Lock entire transaction if requested */
 115
 116                 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.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, buffer_desc->buffer.pointer),
 124                                  ACPI_READ | (obj_desc->field.attribute << 16));
 125                 acpi_ex_release_global_lock (locked);
 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 = (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES (obj_desc->field.bit_length);
 140         if (length > acpi_gbl_integer_byte_width) {
 141                 /* Field is too large for an Integer, create a Buffer instead */
 142
 143                 buffer_desc = acpi_ut_create_buffer_object (length);
 144                 if (!buffer_desc) {
 145                         return_ACPI_STATUS (AE_NO_MEMORY);
 146                 }
 147                 buffer = buffer_desc->buffer.pointer;
 148         }
 149         else {
 150                 /* Field will fit within an Integer (normal case) */
 151
 152                 buffer_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
 153                 if (!buffer_desc) {
 154                         return_ACPI_STATUS (AE_NO_MEMORY);
 155                 }
 156
 157                 length = acpi_gbl_integer_byte_width;
 158                 buffer_desc->integer.value = 0;
 159                 buffer = &buffer_desc->integer.value;
 160         }
 161
 162         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 163                 "field_read [TO]:  Obj %p, Type %X, Buf %p, byte_len %X\n",
 164                 obj_desc, ACPI_GET_OBJECT_TYPE (obj_desc), buffer, (u32) length));
 165         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 166                 "field_read [FROM]: bit_len %X, bit_off %X, byte_off %X\n",
 167                 obj_desc->common_field.bit_length,
 168                 obj_desc->common_field.start_field_bit_offset,
 169                 obj_desc->common_field.base_byte_offset));
 170
 171         /* Lock entire transaction if requested */
 172
 173         locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 174
 175         /* Read from the field */
 176
 177         status = acpi_ex_extract_from_field (obj_desc, buffer, (u32) length);
 178         acpi_ex_release_global_lock (locked);
 179
 180
 181 exit:
 182         if (ACPI_FAILURE (status)) {
 183                 acpi_ut_remove_reference (buffer_desc);
 184         }
 185         else if (ret_buffer_desc) {
 186                 *ret_buffer_desc = buffer_desc;
 187         }
 188
 189         return_ACPI_STATUS (status);
 190 }
 191
 192
 193 /*******************************************************************************
 194  *
 195  * FUNCTION:    acpi_ex_write_data_to_field
 196  *
 197  * PARAMETERS:  source_desc         - Contains data to write
 198  *              obj_desc            - The named field
 199  *              result_desc         - Where the return value is returned, if any
 200  *
 201  * RETURN:      Status
 202  *
 203  * DESCRIPTION: Write to a named field
 204  *
 205  ******************************************************************************/
 206
 207 acpi_status
 208 acpi_ex_write_data_to_field (
 209         union acpi_operand_object       *source_desc,
 210         union acpi_operand_object       *obj_desc,
 211         union acpi_operand_object       **result_desc)
 212 {
 213         acpi_status                     status;
 214         u32                             length;
 215         u32                             required_length;
 216         void                            *buffer;
 217         void                            *new_buffer;
 218         u8                              locked;
 219         union acpi_operand_object       *buffer_desc;
 220
 221
 222         ACPI_FUNCTION_TRACE_PTR ("ex_write_data_to_field", obj_desc);
 223
 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         }
 243         else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 244                          (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
 245                 /*
 246                  * This is an SMBus write.  We will bypass the entire field mechanism
 247                  * and handoff the buffer directly to the handler.
 248                  *
 249                  * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
 250                  */
 251                 if (ACPI_GET_OBJECT_TYPE (source_desc) != ACPI_TYPE_BUFFER) {
 252                         ACPI_REPORT_ERROR (("SMBus write requires Buffer, found type %s\n",
 253                                 acpi_ut_get_object_type_name (source_desc)));
 254
 255                         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
 256                 }
 257
 258                 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
 259                         ACPI_REPORT_ERROR ((
 260                                 "SMBus write requires Buffer of length %X, found length %X\n",
 261                                 ACPI_SMBUS_BUFFER_SIZE, source_desc->buffer.length));
 262
 263                         return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
 264                 }
 265
 266                 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
 267                 if (!buffer_desc) {
 268                         return_ACPI_STATUS (AE_NO_MEMORY);
 269                 }
 270
 271                 buffer = buffer_desc->buffer.pointer;
 272                 ACPI_MEMCPY (buffer, source_desc->buffer.pointer,
 273                         ACPI_SMBUS_BUFFER_SIZE);
 274
 275                 /* Lock entire transaction if requested */
 276
 277                 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 278
 279                 /*
 280                  * Perform the write (returns status and perhaps data in the
 281                  * same buffer)
 282                  * Note: SMBus protocol type is passed in upper 16-bits of Function.
 283                  */
 284                 status = acpi_ex_access_region (obj_desc, 0,
 285                                   (acpi_integer *) buffer,
 286                                   ACPI_WRITE | (obj_desc->field.attribute << 16));
 287                 acpi_ex_release_global_lock (locked);
 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 = ACPI_ROUND_BITS_UP_TO_BYTES (
 323                            obj_desc->common_field.bit_length);
 324
 325         if (length < required_length) {
 326                 /* We need to create a new buffer */
 327
 328                 new_buffer = ACPI_MEM_CALLOCATE (required_length);
 329                 if (!new_buffer) {
 330                         return_ACPI_STATUS (AE_NO_MEMORY);
 331                 }
 332
 333                 /*
 334                  * Copy the original data to the new buffer, starting
 335                  * at Byte zero.  All unused (upper) bytes of the
 336                  * buffer will be 0.
 337                  */
 338                 ACPI_MEMCPY ((char *) new_buffer, (char *) buffer, length);
 339                 buffer = new_buffer;
 340                 length = required_length;
 341         }
 342
 343         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 344                 "field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %X\n",
 345                 source_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (source_desc)),
 346                 ACPI_GET_OBJECT_TYPE (source_desc), buffer, length));
 347
 348         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
 349                 "field_write [TO]:  Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %X\n",
 350                 obj_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (obj_desc)),
 351                 ACPI_GET_OBJECT_TYPE (obj_desc),
 352                 obj_desc->common_field.bit_length,
 353                 obj_desc->common_field.start_field_bit_offset,
 354                 obj_desc->common_field.base_byte_offset));
 355
 356         /* Lock entire transaction if requested */
 357
 358         locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 359
 360         /* Write to the field */
 361
 362         status = acpi_ex_insert_into_field (obj_desc, buffer, length);
 363         acpi_ex_release_global_lock (locked);
 364
 365         /* Free temporary buffer if we used one */
 366
 367         if (new_buffer) {
 368                 ACPI_MEM_FREE (new_buffer);
 369         }
 370
 371         return_ACPI_STATUS (status);
 372 }
 373
 374