LXR linux/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
  50ACPI_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 ******************************************************************************/
  66acpi_status
  67acpi_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        u32 function;
  76
  77        ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
  78
  79        /* Parameter validation */
  80
  81        if (!obj_desc) {
  82                return_ACPI_STATUS(AE_AML_NO_OPERAND);
  83        }
  84        if (!ret_buffer_desc) {
  85                return_ACPI_STATUS(AE_BAD_PARAMETER);
  86        }
  87
  88        if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
  89                /*
  90                 * If the buffer_field arguments have not been previously evaluated,
  91                 * evaluate them now and save the results.
  92                 */
  93                if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
  94                        status = acpi_ds_get_buffer_field_arguments(obj_desc);
  95                        if (ACPI_FAILURE(status)) {
  96                                return_ACPI_STATUS(status);
  97                        }
  98                }
  99        } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 100                   (obj_desc->field.region_obj->region.space_id ==
 101                    ACPI_ADR_SPACE_SMBUS
 102                    || obj_desc->field.region_obj->region.space_id ==
 103                    ACPI_ADR_SPACE_IPMI)) {
 104                /*
 105                 * This is an SMBus or IPMI read. We must create a buffer to hold
 106                 * the data and then directly access the region handler.
 107                 *
 108                 * Note: Smbus protocol value is passed in upper 16-bits of Function
 109                 */
 110                if (obj_desc->field.region_obj->region.space_id ==
 111                    ACPI_ADR_SPACE_SMBUS) {
 112                        length = ACPI_SMBUS_BUFFER_SIZE;
 113                        function =
 114                            ACPI_READ | (obj_desc->field.attribute << 16);
 115                } else {        /* IPMI */
 116
 117                        length = ACPI_IPMI_BUFFER_SIZE;
 118                        function = ACPI_READ;
 119                }
 120
 121                buffer_desc = acpi_ut_create_buffer_object(length);
 122                if (!buffer_desc) {
 123                        return_ACPI_STATUS(AE_NO_MEMORY);
 124                }
 125
 126                /* Lock entire transaction if requested */
 127
 128                acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 129
 130                /* Call the region handler for the read */
 131
 132                status = acpi_ex_access_region(obj_desc, 0,
 133                                               ACPI_CAST_PTR(acpi_integer,
 134                                                             buffer_desc->
 135                                                             buffer.pointer),
 136                                               function);
 137                acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 138                goto exit;
 139        }
 140
 141        /*
 142         * Allocate a buffer for the contents of the field.
 143         *
 144         * If the field is larger than the size of an acpi_integer, create
 145         * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
 146         * the use of arithmetic operators on the returned value if the
 147         * field size is equal or smaller than an Integer.
 148         *
 149         * Note: Field.length is in bits.
 150         */
 151        length =
 152            (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
 153        if (length > acpi_gbl_integer_byte_width) {
 154
 155                /* Field is too large for an Integer, create a Buffer instead */
 156
 157                buffer_desc = acpi_ut_create_buffer_object(length);
 158                if (!buffer_desc) {
 159                        return_ACPI_STATUS(AE_NO_MEMORY);
 160                }
 161                buffer = buffer_desc->buffer.pointer;
 162        } else {
 163                /* Field will fit within an Integer (normal case) */
 164
 165                buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
 166                if (!buffer_desc) {
 167                        return_ACPI_STATUS(AE_NO_MEMORY);
 168                }
 169
 170                length = acpi_gbl_integer_byte_width;
 171                buffer_desc->integer.value = 0;
 172                buffer = &buffer_desc->integer.value;
 173        }
 174
 175        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 176                          "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
 177                          obj_desc, obj_desc->common.type, buffer,
 178                          (u32) length));
 179        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 180                          "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
 181                          obj_desc->common_field.bit_length,
 182                          obj_desc->common_field.start_field_bit_offset,
 183                          obj_desc->common_field.base_byte_offset));
 184
 185        /* Lock entire transaction if requested */
 186
 187        acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 188
 189        /* Read from the field */
 190
 191        status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
 192        acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 193
 194      exit:
 195        if (ACPI_FAILURE(status)) {
 196                acpi_ut_remove_reference(buffer_desc);
 197        } else {
 198                *ret_buffer_desc = buffer_desc;
 199        }
 200
 201        return_ACPI_STATUS(status);
 202}
 203
 204/*******************************************************************************
 205 *
 206 * FUNCTION:    acpi_ex_write_data_to_field
 207 *
 208 * PARAMETERS:  source_desc         - Contains data to write
 209 *              obj_desc            - The named field
 210 *              result_desc         - Where the return value is returned, if any
 211 *
 212 * RETURN:      Status
 213 *
 214 * DESCRIPTION: Write to a named field
 215 *
 216 ******************************************************************************/
 217
 218acpi_status
 219acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
 220                            union acpi_operand_object *obj_desc,
 221                            union acpi_operand_object **result_desc)
 222{
 223        acpi_status status;
 224        u32 length;
 225        void *buffer;
 226        union acpi_operand_object *buffer_desc;
 227        u32 function;
 228
 229        ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
 230
 231        /* Parameter validation */
 232
 233        if (!source_desc || !obj_desc) {
 234                return_ACPI_STATUS(AE_AML_NO_OPERAND);
 235        }
 236
 237        if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
 238                /*
 239                 * If the buffer_field arguments have not been previously evaluated,
 240                 * evaluate them now and save the results.
 241                 */
 242                if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 243                        status = acpi_ds_get_buffer_field_arguments(obj_desc);
 244                        if (ACPI_FAILURE(status)) {
 245                                return_ACPI_STATUS(status);
 246                        }
 247                }
 248        } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 249                   (obj_desc->field.region_obj->region.space_id ==
 250                    ACPI_ADR_SPACE_SMBUS
 251                    || obj_desc->field.region_obj->region.space_id ==
 252                    ACPI_ADR_SPACE_IPMI)) {
 253                /*
 254                 * This is an SMBus or IPMI write. We will bypass the entire field
 255                 * mechanism and handoff the buffer directly to the handler. For
 256                 * these address spaces, the buffer is bi-directional; on a write,
 257                 * return data is returned in the same buffer.
 258                 *
 259                 * Source must be a buffer of sufficient size:
 260                 * ACPI_SMBUS_BUFFER_SIZE or ACPI_IPMI_BUFFER_SIZE.
 261                 *
 262                 * Note: SMBus protocol type is passed in upper 16-bits of Function
 263                 */
 264                if (source_desc->common.type != ACPI_TYPE_BUFFER) {
 265                        ACPI_ERROR((AE_INFO,
 266                                    "SMBus or IPMI write requires Buffer, found type %s",
 267                                    acpi_ut_get_object_type_name(source_desc)));
 268
 269                        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 270                }
 271
 272                if (obj_desc->field.region_obj->region.space_id ==
 273                    ACPI_ADR_SPACE_SMBUS) {
 274                        length = ACPI_SMBUS_BUFFER_SIZE;
 275                        function =
 276                            ACPI_WRITE | (obj_desc->field.attribute << 16);
 277                } else {        /* IPMI */
 278
 279                        length = ACPI_IPMI_BUFFER_SIZE;
 280                        function = ACPI_WRITE;
 281                }
 282
 283                if (source_desc->buffer.length < length) {
 284                        ACPI_ERROR((AE_INFO,
 285                                    "SMBus or IPMI write requires Buffer of length %X, found length %X",
 286                                    length, source_desc->buffer.length));
 287
 288                        return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
 289                }
 290
 291                /* Create the bi-directional buffer */
 292
 293                buffer_desc = acpi_ut_create_buffer_object(length);
 294                if (!buffer_desc) {
 295                        return_ACPI_STATUS(AE_NO_MEMORY);
 296                }
 297
 298                buffer = buffer_desc->buffer.pointer;
 299                ACPI_MEMCPY(buffer, source_desc->buffer.pointer, length);
 300
 301                /* Lock entire transaction if requested */
 302
 303                acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 304
 305                /*
 306                 * Perform the write (returns status and perhaps data in the
 307                 * same buffer)
 308                 */
 309                status = acpi_ex_access_region(obj_desc, 0,
 310                                               (acpi_integer *) buffer,
 311                                               function);
 312                acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 313
 314                *result_desc = buffer_desc;
 315                return_ACPI_STATUS(status);
 316        }
 317
 318        /* Get a pointer to the data to be written */
 319
 320        switch (source_desc->common.type) {
 321        case ACPI_TYPE_INTEGER:
 322                buffer = &source_desc->integer.value;
 323                length = sizeof(source_desc->integer.value);
 324                break;
 325
 326        case ACPI_TYPE_BUFFER:
 327                buffer = source_desc->buffer.pointer;
 328                length = source_desc->buffer.length;
 329                break;
 330
 331        case ACPI_TYPE_STRING:
 332                buffer = source_desc->string.pointer;
 333                length = source_desc->string.length;
 334                break;
 335
 336        default:
 337                return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 338        }
 339
 340        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 341                          "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
 342                          source_desc,
 343                          acpi_ut_get_type_name(source_desc->common.type),
 344                          source_desc->common.type, buffer, length));
 345
 346        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 347                          "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
 348                          obj_desc,
 349                          acpi_ut_get_type_name(obj_desc->common.type),
 350                          obj_desc->common.type,
 351                          obj_desc->common_field.bit_length,
 352                          obj_desc->common_field.start_field_bit_offset,
 353                          obj_desc->common_field.base_byte_offset));
 354
 355        /* Lock entire transaction if requested */
 356
 357        acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 358
 359        /* Write to the field */
 360
 361        status = acpi_ex_insert_into_field(obj_desc, buffer, length);
 362        acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 363
 364        return_ACPI_STATUS(status);
 365}
 366