git.oblomov.eu Git - linux-2.6/blob - 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 (obj_desc->common.type == 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 if ((obj_desc->common.type == 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, obj_desc->common.type, 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         void *buffer;
 214         union acpi_operand_object *buffer_desc;
 215
 216         ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
 217
 218         /* Parameter validation */
 219
 220         if (!source_desc || !obj_desc) {
 221                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
 222         }
 223
 224         if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
 225                 /*
 226                  * If the buffer_field arguments have not been previously evaluated,
 227                  * evaluate them now and save the results.
 228                  */
 229                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 230                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 231                         if (ACPI_FAILURE(status)) {
 232                                 return_ACPI_STATUS(status);
 233                         }
 234                 }
 235         } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 236                    (obj_desc->field.region_obj->region.space_id ==
 237                     ACPI_ADR_SPACE_SMBUS)) {
 238                 /*
 239                  * This is an SMBus write.  We will bypass the entire field mechanism
 240                  * and handoff the buffer directly to the handler.
 241                  *
 242                  * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
 243                  */
 244                 if (source_desc->common.type != ACPI_TYPE_BUFFER) {
 245                         ACPI_ERROR((AE_INFO,
 246                                     "SMBus write requires Buffer, found type %s",
 247                                     acpi_ut_get_object_type_name(source_desc)));
 248
 249                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 250                 }
 251
 252                 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
 253                         ACPI_ERROR((AE_INFO,
 254                                     "SMBus write requires Buffer of length %X, found length %X",
 255                                     ACPI_SMBUS_BUFFER_SIZE,
 256                                     source_desc->buffer.length));
 257
 258                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
 259                 }
 260
 261                 buffer_desc =
 262                     acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
 263                 if (!buffer_desc) {
 264                         return_ACPI_STATUS(AE_NO_MEMORY);
 265                 }
 266
 267                 buffer = buffer_desc->buffer.pointer;
 268                 ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
 269                             ACPI_SMBUS_BUFFER_SIZE);
 270
 271                 /* Lock entire transaction if requested */
 272
 273                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 274
 275                 /*
 276                  * Perform the write (returns status and perhaps data in the
 277                  * same buffer)
 278                  * Note: SMBus protocol type is passed in upper 16-bits of Function.
 279                  */
 280                 status = acpi_ex_access_region(obj_desc, 0,
 281                                                (acpi_integer *) buffer,
 282                                                ACPI_WRITE | (obj_desc->field.
 283                                                              attribute << 16));
 284                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 285
 286                 *result_desc = buffer_desc;
 287                 return_ACPI_STATUS(status);
 288         }
 289
 290         /* Get a pointer to the data to be written */
 291
 292         switch (source_desc->common.type) {
 293         case ACPI_TYPE_INTEGER:
 294                 buffer = &source_desc->integer.value;
 295                 length = sizeof(source_desc->integer.value);
 296                 break;
 297
 298         case ACPI_TYPE_BUFFER:
 299                 buffer = source_desc->buffer.pointer;
 300                 length = source_desc->buffer.length;
 301                 break;
 302
 303         case ACPI_TYPE_STRING:
 304                 buffer = source_desc->string.pointer;
 305                 length = source_desc->string.length;
 306                 break;
 307
 308         default:
 309                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 310         }
 311
 312         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 313                           "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
 314                           source_desc,
 315                           acpi_ut_get_type_name(source_desc->common.type),
 316                           source_desc->common.type, buffer, length));
 317
 318         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 319                           "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
 320                           obj_desc,
 321                           acpi_ut_get_type_name(obj_desc->common.type),
 322                           obj_desc->common.type,
 323                           obj_desc->common_field.bit_length,
 324                           obj_desc->common_field.start_field_bit_offset,
 325                           obj_desc->common_field.base_byte_offset));
 326
 327         /* Lock entire transaction if requested */
 328
 329         acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 330
 331         /* Write to the field */
 332
 333         status = acpi_ex_insert_into_field(obj_desc, buffer, length);
 334         acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 335
 336         return_ACPI_STATUS(status);
 337 }