Logo Search packages:      
Sourcecode: linux version File versions  Download package

exfield.c

/******************************************************************************
 *
 * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acdispat.h>
#include <acpi/acinterp.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exfield")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_read_data_from_field
 *
 * PARAMETERS:  walk_state          - Current execution state
 *              obj_desc            - The named field
 *              ret_buffer_desc     - Where the return data object is stored
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read from a named field.  Returns either an Integer or a
 *              Buffer, depending on the size of the field.
 *
 ******************************************************************************/
acpi_status
acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
                       union acpi_operand_object *obj_desc,
                       union acpi_operand_object **ret_buffer_desc)
{
      acpi_status status;
      union acpi_operand_object *buffer_desc;
      acpi_size length;
      void *buffer;
      u8 locked;

      ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);

      /* Parameter validation */

      if (!obj_desc) {
            return_ACPI_STATUS(AE_AML_NO_OPERAND);
      }
      if (!ret_buffer_desc) {
            return_ACPI_STATUS(AE_BAD_PARAMETER);
      }

      if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
            /*
             * If the buffer_field arguments have not been previously evaluated,
             * evaluate them now and save the results.
             */
            if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
                  status = acpi_ds_get_buffer_field_arguments(obj_desc);
                  if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                  }
            }
      } else
          if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
            && (obj_desc->field.region_obj->region.space_id ==
                ACPI_ADR_SPACE_SMBUS)) {
            /*
             * This is an SMBus read.  We must create a buffer to hold the data
             * and directly access the region handler.
             */
            buffer_desc =
                acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
            if (!buffer_desc) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            /* Lock entire transaction if requested */

            locked =
                acpi_ex_acquire_global_lock(obj_desc->common_field.
                                    field_flags);

            /*
             * Perform the read.
             * Note: Smbus protocol value is passed in upper 16-bits of Function
             */
            status = acpi_ex_access_region(obj_desc, 0,
                                     ACPI_CAST_PTR(acpi_integer,
                                               buffer_desc->
                                               buffer.pointer),
                                     ACPI_READ | (obj_desc->field.
                                              attribute << 16));
            acpi_ex_release_global_lock(locked);
            goto exit;
      }

      /*
       * Allocate a buffer for the contents of the field.
       *
       * If the field is larger than the size of an acpi_integer, create
       * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
       * the use of arithmetic operators on the returned value if the
       * field size is equal or smaller than an Integer.
       *
       * Note: Field.length is in bits.
       */
      length =
          (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
      if (length > acpi_gbl_integer_byte_width) {

            /* Field is too large for an Integer, create a Buffer instead */

            buffer_desc = acpi_ut_create_buffer_object(length);
            if (!buffer_desc) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }
            buffer = buffer_desc->buffer.pointer;
      } else {
            /* Field will fit within an Integer (normal case) */

            buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
            if (!buffer_desc) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            length = acpi_gbl_integer_byte_width;
            buffer_desc->integer.value = 0;
            buffer = &buffer_desc->integer.value;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                    "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
                    obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
                    (u32) length));
      ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                    "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
                    obj_desc->common_field.bit_length,
                    obj_desc->common_field.start_field_bit_offset,
                    obj_desc->common_field.base_byte_offset));

      /* Lock entire transaction if requested */

      locked =
          acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

      /* Read from the field */

      status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
      acpi_ex_release_global_lock(locked);

      exit:
      if (ACPI_FAILURE(status)) {
            acpi_ut_remove_reference(buffer_desc);
      } else {
            *ret_buffer_desc = buffer_desc;
      }

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_write_data_to_field
 *
 * PARAMETERS:  source_desc         - Contains data to write
 *              obj_desc            - The named field
 *              result_desc         - Where the return value is returned, if any
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Write to a named field
 *
 ******************************************************************************/

acpi_status
acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
                      union acpi_operand_object *obj_desc,
                      union acpi_operand_object **result_desc)
{
      acpi_status status;
      u32 length;
      u32 required_length;
      void *buffer;
      void *new_buffer;
      u8 locked;
      union acpi_operand_object *buffer_desc;

      ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);

      /* Parameter validation */

      if (!source_desc || !obj_desc) {
            return_ACPI_STATUS(AE_AML_NO_OPERAND);
      }

      if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
            /*
             * If the buffer_field arguments have not been previously evaluated,
             * evaluate them now and save the results.
             */
            if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
                  status = acpi_ds_get_buffer_field_arguments(obj_desc);
                  if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                  }
            }
      } else
          if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
            && (obj_desc->field.region_obj->region.space_id ==
                ACPI_ADR_SPACE_SMBUS)) {
            /*
             * This is an SMBus write.  We will bypass the entire field mechanism
             * and handoff the buffer directly to the handler.
             *
             * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
             */
            if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
                  ACPI_ERROR((AE_INFO,
                            "SMBus write requires Buffer, found type %s",
                            acpi_ut_get_object_type_name(source_desc)));

                  return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
            }

            if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
                  ACPI_ERROR((AE_INFO,
                            "SMBus write requires Buffer of length %X, found length %X",
                            ACPI_SMBUS_BUFFER_SIZE,
                            source_desc->buffer.length));

                  return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
            }

            buffer_desc =
                acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
            if (!buffer_desc) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            buffer = buffer_desc->buffer.pointer;
            ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
                      ACPI_SMBUS_BUFFER_SIZE);

            /* Lock entire transaction if requested */

            locked =
                acpi_ex_acquire_global_lock(obj_desc->common_field.
                                    field_flags);

            /*
             * Perform the write (returns status and perhaps data in the
             * same buffer)
             * Note: SMBus protocol type is passed in upper 16-bits of Function.
             */
            status = acpi_ex_access_region(obj_desc, 0,
                                     (acpi_integer *) buffer,
                                     ACPI_WRITE | (obj_desc->field.
                                               attribute << 16));
            acpi_ex_release_global_lock(locked);

            *result_desc = buffer_desc;
            return_ACPI_STATUS(status);
      }

      /* Get a pointer to the data to be written */

      switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
      case ACPI_TYPE_INTEGER:
            buffer = &source_desc->integer.value;
            length = sizeof(source_desc->integer.value);
            break;

      case ACPI_TYPE_BUFFER:
            buffer = source_desc->buffer.pointer;
            length = source_desc->buffer.length;
            break;

      case ACPI_TYPE_STRING:
            buffer = source_desc->string.pointer;
            length = source_desc->string.length;
            break;

      default:
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
      }

      /*
       * We must have a buffer that is at least as long as the field
       * we are writing to.  This is because individual fields are
       * indivisible and partial writes are not supported -- as per
       * the ACPI specification.
       */
      new_buffer = NULL;
      required_length =
          ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);

      if (length < required_length) {

            /* We need to create a new buffer */

            new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
            if (!new_buffer) {
                  return_ACPI_STATUS(AE_NO_MEMORY);
            }

            /*
             * Copy the original data to the new buffer, starting
             * at Byte zero.  All unused (upper) bytes of the
             * buffer will be 0.
             */
            ACPI_MEMCPY((char *)new_buffer, (char *)buffer, length);
            buffer = new_buffer;
            length = required_length;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                    "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
                    source_desc,
                    acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
                                    (source_desc)),
                    ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));

      ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                    "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
                    obj_desc,
                    acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
                    ACPI_GET_OBJECT_TYPE(obj_desc),
                    obj_desc->common_field.bit_length,
                    obj_desc->common_field.start_field_bit_offset,
                    obj_desc->common_field.base_byte_offset));

      /* Lock entire transaction if requested */

      locked =
          acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

      /* Write to the field */

      status = acpi_ex_insert_into_field(obj_desc, buffer, length);
      acpi_ex_release_global_lock(locked);

      /* Free temporary buffer if we used one */

      if (new_buffer) {
            ACPI_FREE(new_buffer);
      }

      return_ACPI_STATUS(status);
}

Generated by  Doxygen 1.6.0   Back to index