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/******************************************************************************

 *

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

 *

 *****************************************************************************/

/*

 * Copyright (C) 2000 - 2004, 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 (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,

                "field_read [TO]:  Obj %p, Type %X, Buf %p, byte_len %X\n",

                obj_desc, ACPI_GET_OBJECT_TYPE (obj_desc), buffer, (u32) length));

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                "field_read [FROM]: bit_len %X, bit_off %X, byte_off %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 if (ret_buffer_desc) {

                *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

 *

 * 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_REPORT_ERROR (("SMBus write requires Buffer, found type %s\n",

                                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_REPORT_ERROR (("SMBus write requires Buffer of length %X, found length %X\n",

                                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_MEM_CALLOCATE (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,

                "field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %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,

                "field_write [TO]:  Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %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_MEM_FREE (new_buffer);

        }

        return_ACPI_STATUS (status);

}