drivers/acpi/acpica/exfield.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, Intel Corp.
   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 "accommon.h"
  46 #include "acdispat.h"
  47 #include "acinterp.h"
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exfield")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ex_read_data_from_field
  55  *
  56  * PARAMETERS:  walk_state          - Current execution state
  57  *              obj_desc            - The named field
  58  *              ret_buffer_desc     - Where the return data object is stored
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Read from a named field.  Returns either an Integer or a
  63  *              Buffer, depending on the size of the field.
  64  *
  65  ******************************************************************************/
  66 acpi_status
  67 acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
  68                              union acpi_operand_object *obj_desc,
  69                              union acpi_operand_object **ret_buffer_desc)
  70 {
  71         acpi_status status;
  72         union acpi_operand_object *buffer_desc;
  73         acpi_size length;
  74         void *buffer;
  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                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 115
 116                 /*
 117                  * Perform the read.
 118                  * Note: Smbus protocol value is passed in upper 16-bits of Function
 119                  */
 120                 status = acpi_ex_access_region(obj_desc, 0,
 121                                                ACPI_CAST_PTR(acpi_integer,
 122                                                              buffer_desc->
 123                                                              buffer.pointer),
 124                                                ACPI_READ | (obj_desc->field.
 125                                                             attribute << 16));
 126                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 127                 goto exit;
 128         }
 129
 130         /*
 131          * Allocate a buffer for the contents of the field.
 132          *
 133          * If the field is larger than the size of an acpi_integer, create
 134          * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
 135          * the use of arithmetic operators on the returned value if the
 136          * field size is equal or smaller than an Integer.
 137          *
 138          * Note: Field.length is in bits.
 139          */
 140         length =
 141             (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
 142         if (length > acpi_gbl_integer_byte_width) {
 143
 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         } else {
 152                 /* Field will fit within an Integer (normal case) */
 153
 154                 buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
 155                 if (!buffer_desc) {
 156                         return_ACPI_STATUS(AE_NO_MEMORY);
 157                 }
 158
 159                 length = acpi_gbl_integer_byte_width;
 160                 buffer_desc->integer.value = 0;
 161                 buffer = &buffer_desc->integer.value;
 162         }
 163
 164         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 165                           "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
 166                           obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
 167                           (u32) length));
 168         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 169                           "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %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         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(obj_desc->common_field.field_flags);
 182
 183       exit:
 184         if (ACPI_FAILURE(status)) {
 185                 acpi_ut_remove_reference(buffer_desc);
 186         } else {
 187                 *ret_buffer_desc = buffer_desc;
 188         }
 189
 190         return_ACPI_STATUS(status);
 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(union acpi_operand_object *source_desc,
 209                             union acpi_operand_object *obj_desc,
 210                             union acpi_operand_object **result_desc)
 211 {
 212         acpi_status status;
 213         u32 length;
 214         void *buffer;
 215         union acpi_operand_object *buffer_desc;
 216
 217         ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
 218
 219         /* Parameter validation */
 220
 221         if (!source_desc || !obj_desc) {
 222                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
 223         }
 224
 225         if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
 226                 /*
 227                  * If the buffer_field arguments have not been previously evaluated,
 228                  * evaluate them now and save the results.
 229                  */
 230                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 231                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 232                         if (ACPI_FAILURE(status)) {
 233                                 return_ACPI_STATUS(status);
 234                         }
 235                 }
 236         } else
 237             if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
 238                 && (obj_desc->field.region_obj->region.space_id ==
 239                     ACPI_ADR_SPACE_SMBUS)) {
 240                 /*
 241                  * This is an SMBus write.  We will bypass the entire field mechanism
 242                  * and handoff the buffer directly to the handler.
 243                  *
 244                  * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
 245                  */
 246                 if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
 247                         ACPI_ERROR((AE_INFO,
 248                                     "SMBus write requires Buffer, found type %s",
 249                                     acpi_ut_get_object_type_name(source_desc)));
 250
 251                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 252                 }
 253
 254                 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
 255                         ACPI_ERROR((AE_INFO,
 256                                     "SMBus write requires Buffer of length %X, found length %X",
 257                                     ACPI_SMBUS_BUFFER_SIZE,
 258                                     source_desc->buffer.length));
 259
 260                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
 261                 }
 262
 263                 buffer_desc =
 264                     acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
 265                 if (!buffer_desc) {
 266                         return_ACPI_STATUS(AE_NO_MEMORY);
 267                 }
 268
 269                 buffer = buffer_desc->buffer.pointer;
 270                 ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
 271                             ACPI_SMBUS_BUFFER_SIZE);
 272
 273                 /* Lock entire transaction if requested */
 274
 275                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 276
 277                 /*
 278                  * Perform the write (returns status and perhaps data in the
 279                  * same buffer)
 280                  * Note: SMBus protocol type is passed in upper 16-bits of Function.
 281                  */
 282                 status = acpi_ex_access_region(obj_desc, 0,
 283                                                (acpi_integer *) buffer,
 284                                                ACPI_WRITE | (obj_desc->field.
 285                                                              attribute << 16));
 286                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 287
 288                 *result_desc = buffer_desc;
 289                 return_ACPI_STATUS(status);
 290         }
 291
 292         /* Get a pointer to the data to be written */
 293
 294         switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
 295         case ACPI_TYPE_INTEGER:
 296                 buffer = &source_desc->integer.value;
 297                 length = sizeof(source_desc->integer.value);
 298                 break;
 299
 300         case ACPI_TYPE_BUFFER:
 301                 buffer = source_desc->buffer.pointer;
 302                 length = source_desc->buffer.length;
 303                 break;
 304
 305         case ACPI_TYPE_STRING:
 306                 buffer = source_desc->string.pointer;
 307                 length = source_desc->string.length;
 308                 break;
 309
 310         default:
 311                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 312         }
 313
 314         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 315                           "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
 316                           source_desc,
 317                           acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
 318                                                 (source_desc)),
 319                           ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));
 320
 321         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 322                           "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
 323                           obj_desc,
 324                           acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
 325                           ACPI_GET_OBJECT_TYPE(obj_desc),
 326                           obj_desc->common_field.bit_length,
 327                           obj_desc->common_field.start_field_bit_offset,
 328                           obj_desc->common_field.base_byte_offset));
 329
 330         /* Lock entire transaction if requested */
 331
 332         acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 333
 334         /* Write to the field */
 335
 336         status = acpi_ex_insert_into_field(obj_desc, buffer, length);
 337         acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 338
 339         return_ACPI_STATUS(status);
 340 }