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

 *

 * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities

 *

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

/*

 * 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/acinterp.h>

#include <acpi/amlcode.h>

#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_EXECUTER

         ACPI_MODULE_NAME    ("exprep")

#ifdef ACPI_UNDER_DEVELOPMENT

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

 *

 * FUNCTION:    acpi_ex_generate_access

 *

 * PARAMETERS:  field_bit_offset    - Start of field within parent region/buffer

 *              field_bit_length    - Length of field in bits

 *              region_length       - Length of parent in bytes

 *

 * RETURN:      Field granularity (8, 16, 32 or 64) and

 *              byte_alignment (1, 2, 3, or 4)

 *

 * DESCRIPTION: Generate an optimal access width for fields defined with the

 *              any_acc keyword.

 *

 * NOTE: Need to have the region_length in order to check for boundary

 *       conditions (end-of-region).  However, the region_length is a deferred

 *       operation.  Therefore, to complete this implementation, the generation

 *       of this access width must be deferred until the region length has

 *       been evaluated.

 *

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

static u32

acpi_ex_generate_access (

        u32                             field_bit_offset,

        u32                             field_bit_length,

        u32                             region_length)

{

        u32                             field_byte_length;

        u32                             field_byte_offset;

        u32                             field_byte_end_offset;

        u32                             access_byte_width;

        u32                             field_start_offset;

        u32                             field_end_offset;

        u32                             minimum_access_width = 0xFFFFFFFF;

        u32                             minimum_accesses = 0xFFFFFFFF;

        u32                             accesses;

        ACPI_FUNCTION_TRACE ("ex_generate_access");

        /* Round Field start offset and length to "minimal" byte boundaries */

        field_byte_offset  = ACPI_DIV_8 (ACPI_ROUND_DOWN (field_bit_offset, 8));

        field_byte_end_offset = ACPI_DIV_8 (ACPI_ROUND_UP (field_bit_length + field_bit_offset, 8));

        field_byte_length  = field_byte_end_offset - field_byte_offset;

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "Bit length %d, Bit offset %d\n",

                        field_bit_length, field_bit_offset));

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "Byte Length %d, Byte Offset %d, End Offset %d\n",

                        field_byte_length, field_byte_offset, field_byte_end_offset));

        /*

         * Iterative search for the maximum access width that is both aligned

         * and does not go beyond the end of the region

         *

         * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)

         */

        for (access_byte_width = 1; access_byte_width <= 8; access_byte_width <<= 1) {

                /*

                 * 1) Round end offset up to next access boundary and make sure that this

                 *    does not go beyond the end of the parent region.

                 * 2) When the Access width is greater than the field_byte_length, we are done.

                 *    (This does not optimize for the perfectly aligned case yet).

                 */

                if (ACPI_ROUND_UP (field_byte_end_offset, access_byte_width) <= region_length) {

                        field_start_offset = ACPI_ROUND_DOWN (field_byte_offset, access_byte_width) /

                                          access_byte_width;

                        field_end_offset = ACPI_ROUND_UP   ((field_byte_length + field_byte_offset),

                                          access_byte_width) / access_byte_width;

                        accesses         = field_end_offset - field_start_offset;

                        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                        "access_width %d end is within region\n", access_byte_width));

                        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                        "Field Start %d, Field End %d -- requires %d accesses\n",

                                        field_start_offset, field_end_offset, accesses));

                        /* Single access is optimal */

                        if (accesses <= 1) {

                                ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                                "Entire field can be accessed with one operation of size %d\n",

                                                access_byte_width));

                                return_VALUE (access_byte_width);

                        }

                        /*

                         * Fits in the region, but requires more than one read/write.

                         * try the next wider access on next iteration

                         */

                        if (accesses < minimum_accesses) {

                                minimum_accesses   = accesses;

                                minimum_access_width = access_byte_width;

                        }

                }

                else {

                        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                        "access_width %d end is NOT within region\n", access_byte_width));

                        if (access_byte_width == 1) {

                                ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                                "Field goes beyond end-of-region!\n"));

                                return_VALUE (0);     /* Field does not fit in the region at all */

                        }

                        /* This width goes beyond the end-of-region, back off to previous access */

                        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                                        "Backing off to previous optimal access width of %d\n",

                                        minimum_access_width));

                        return_VALUE (minimum_access_width);

                }

        }

        /* Could not read/write field with one operation, just use max access width */

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "Cannot access field in one operation, using width 8\n"));

        return_VALUE (8);

}

#endif /* ACPI_UNDER_DEVELOPMENT */

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

 *

 * FUNCTION:    acpi_ex_decode_field_access

 *

 * PARAMETERS:  Access          - Encoded field access bits

 *              Length          - Field length.

 *

 * RETURN:      Field granularity (8, 16, 32 or 64) and

 *              byte_alignment (1, 2, 3, or 4)

 *

 * DESCRIPTION: Decode the access_type bits of a field definition.

 *

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

static u32

acpi_ex_decode_field_access (

        union acpi_operand_object       *obj_desc,

        u8                              field_flags,

        u32                             *return_byte_alignment)

{

        u32                             access;

        u32                             byte_alignment;

        u32                             bit_length;

        ACPI_FUNCTION_TRACE ("ex_decode_field_access");

        access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);

        switch (access) {

        case AML_FIELD_ACCESS_ANY:

#ifdef ACPI_UNDER_DEVELOPMENT

                byte_alignment = acpi_ex_generate_access (obj_desc->common_field.start_field_bit_offset,

                                 obj_desc->common_field.bit_length,

                                 0xFFFFFFFF /* Temp until we pass region_length as param */);

                bit_length = byte_alignment * 8;

#endif

                byte_alignment = 1;

                bit_length = 8;

                break;

        case AML_FIELD_ACCESS_BYTE:

        case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */

                byte_alignment = 1;

                bit_length    = 8;

                break;

        case AML_FIELD_ACCESS_WORD:

                byte_alignment = 2;

                bit_length    = 16;

                break;

        case AML_FIELD_ACCESS_DWORD:

                byte_alignment = 4;

                bit_length    = 32;

                break;

        case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */

                byte_alignment = 8;

                bit_length    = 64;

                break;

        default:

                /* Invalid field access type */

                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,

                        "Unknown field access type %X\n",

                        access));

                return_VALUE (0);

        }

        if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {

                /*

                 * buffer_field access can be on any byte boundary, so the

                 * byte_alignment is always 1 byte -- regardless of any byte_alignment

                 * implied by the field access type.

                 */

                byte_alignment = 1;

        }

        *return_byte_alignment = byte_alignment;

        return_VALUE (bit_length);

}

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

 *

 * FUNCTION:    acpi_ex_prep_common_field_object

 *

 * PARAMETERS:  obj_desc            - The field object

 *              field_flags         - Access, lock_rule, and update_rule.

 *                                    The format of a field_flag is described

 *                                    in the ACPI specification

 *              field_bit_position  - Field start position

 *              field_bit_length    - Field length in number of bits

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Initialize the areas of the field object that are common

 *              to the various types of fields.  Note: This is very "sensitive"

 *              code because we are solving the general case for field

 *              alignment.

 *

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

acpi_status

acpi_ex_prep_common_field_object (

        union acpi_operand_object       *obj_desc,

        u8                              field_flags,

        u8                              field_attribute,

        u32                             field_bit_position,

        u32                             field_bit_length)

{

        u32                             access_bit_width;

        u32                             byte_alignment;

        u32                             nearest_byte_address;

        ACPI_FUNCTION_TRACE ("ex_prep_common_field_object");

        /*

         * Note: the structure being initialized is the

         * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common

         * area are initialized by this procedure.

         */

        obj_desc->common_field.field_flags = field_flags;

        obj_desc->common_field.attribute = field_attribute;

        obj_desc->common_field.bit_length = field_bit_length;

        /*

         * Decode the access type so we can compute offsets.  The access type gives

         * two pieces of information - the width of each field access and the

         * necessary byte_alignment (address granularity) of the access.

         *

         * For any_acc, the access_bit_width is the largest width that is both

         * necessary and possible in an attempt to access the whole field in one

         * I/O operation.  However, for any_acc, the byte_alignment is always one

         * byte.

         *

         * For all Buffer Fields, the byte_alignment is always one byte.

         *

         * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is

         * the same (equivalent) as the byte_alignment.

         */

        access_bit_width = acpi_ex_decode_field_access (obj_desc, field_flags,

                          &byte_alignment);

        if (!access_bit_width) {

                return_ACPI_STATUS (AE_AML_OPERAND_VALUE);

        }

        /* Setup width (access granularity) fields */

        obj_desc->common_field.access_byte_width = (u8)

                        ACPI_DIV_8 (access_bit_width); /* 1, 2, 4,  8 */

        /*

         * base_byte_offset is the address of the start of the field within the

         * region.  It is the byte address of the first *datum* (field-width data

         * unit) of the field. (i.e., the first datum that contains at least the

         * first *bit* of the field.)

         *

         * Note: byte_alignment is always either equal to the access_bit_width or 8

         * (Byte access), and it defines the addressing granularity of the parent

         * region or buffer.

         */

        nearest_byte_address =

                        ACPI_ROUND_BITS_DOWN_TO_BYTES (field_bit_position);

        obj_desc->common_field.base_byte_offset = (u32)

                        ACPI_ROUND_DOWN (nearest_byte_address, byte_alignment);

        /*

         * start_field_bit_offset is the offset of the first bit of the field within

         * a field datum.

         */

        obj_desc->common_field.start_field_bit_offset = (u8)

                (field_bit_position - ACPI_MUL_8 (obj_desc->common_field.base_byte_offset));

        /*

         * Valid bits -- the number of bits that compose a partial datum,

         * 1) At the end of the field within the region (arbitrary starting bit

         *    offset)

         * 2) At the end of a buffer used to contain the field (starting offset

         *    always zero)

         */

        obj_desc->common_field.end_field_valid_bits = (u8)

                ((obj_desc->common_field.start_field_bit_offset + field_bit_length) %

                                  access_bit_width);

        /* start_buffer_bit_offset always = 0 */

        obj_desc->common_field.end_buffer_valid_bits = (u8)

                (field_bit_length % access_bit_width);

        /*

         * datum_valid_bits is the number of valid field bits in the first

         * field datum.

         */

        obj_desc->common_field.datum_valid_bits  = (u8)

                (access_bit_width - obj_desc->common_field.start_field_bit_offset);

        /*

         * Does the entire field fit within a single field access element? (datum)

         * (i.e., without crossing a datum boundary)

         */

        if ((obj_desc->common_field.start_field_bit_offset + field_bit_length) <=

                        (u16) access_bit_width) {

                obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;

        }

        return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    acpi_ex_prep_field_value

 *

 * PARAMETERS:  Node                - Owning Node

 *              region_node         - Region in which field is being defined

 *              field_flags         - Access, lock_rule, and update_rule.

 *              field_bit_position  - Field start position

 *              field_bit_length    - Field length in number of bits

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Construct an union acpi_operand_object of type def_field and

 *              connect it to the parent Node.

 *

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

acpi_status

acpi_ex_prep_field_value (

        struct acpi_create_field_info   *info)

{

        union acpi_operand_object       *obj_desc;

        u32                             type;

        acpi_status                     status;

        ACPI_FUNCTION_TRACE ("ex_prep_field_value");

        /* Parameter validation */

        if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {

                if (!info->region_node) {

                        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null region_node\n"));

                        return_ACPI_STATUS (AE_AML_NO_OPERAND);

                }

                type = acpi_ns_get_type (info->region_node);

                if (type != ACPI_TYPE_REGION) {

                        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,

                                "Needed Region, found type %X (%s)\n",

                                type, acpi_ut_get_type_name (type)));

                        return_ACPI_STATUS (AE_AML_OPERAND_TYPE);

                }

        }

        /* Allocate a new field object */

        obj_desc = acpi_ut_create_internal_object (info->field_type);

        if (!obj_desc) {

                return_ACPI_STATUS (AE_NO_MEMORY);

        }

        /* Initialize areas of the object that are common to all fields */

        obj_desc->common_field.node = info->field_node;

        status = acpi_ex_prep_common_field_object (obj_desc, info->field_flags,

                         info->attribute, info->field_bit_position, info->field_bit_length);

        if (ACPI_FAILURE (status)) {

                acpi_ut_delete_object_desc (obj_desc);

                return_ACPI_STATUS (status);

        }

        /* Initialize areas of the object that are specific to the field type */

        switch (info->field_type) {

        case ACPI_TYPE_LOCAL_REGION_FIELD:

                obj_desc->field.region_obj   = acpi_ns_get_attached_object (info->region_node);

                /* An additional reference for the container */

                acpi_ut_add_reference (obj_desc->field.region_obj);

                ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "region_field: bit_off %X, Off %X, Gran %X, Region %p\n",

                        obj_desc->field.start_field_bit_offset, obj_desc->field.base_byte_offset,

                        obj_desc->field.access_byte_width, obj_desc->field.region_obj));

                break;

        case ACPI_TYPE_LOCAL_BANK_FIELD:

                obj_desc->bank_field.value   = info->bank_value;

                obj_desc->bank_field.region_obj = acpi_ns_get_attached_object (info->region_node);

                obj_desc->bank_field.bank_obj = acpi_ns_get_attached_object (info->register_node);

                /* An additional reference for the attached objects */

                acpi_ut_add_reference (obj_desc->bank_field.region_obj);

                acpi_ut_add_reference (obj_desc->bank_field.bank_obj);

                ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "Bank Field: bit_off %X, Off %X, Gran %X, Region %p, bank_reg %p\n",

                        obj_desc->bank_field.start_field_bit_offset,

                        obj_desc->bank_field.base_byte_offset,

                        obj_desc->field.access_byte_width,

                        obj_desc->bank_field.region_obj,

                        obj_desc->bank_field.bank_obj));

                break;

        case ACPI_TYPE_LOCAL_INDEX_FIELD:

                obj_desc->index_field.index_obj = acpi_ns_get_attached_object (info->register_node);

                obj_desc->index_field.data_obj = acpi_ns_get_attached_object (info->data_register_node);

                obj_desc->index_field.value  = (u32)

                        (info->field_bit_position / ACPI_MUL_8 (obj_desc->field.access_byte_width));

                if (!obj_desc->index_field.data_obj || !obj_desc->index_field.index_obj) {

                        ACPI_REPORT_ERROR (("Null Index Object during field prep\n"));

                        return_ACPI_STATUS (AE_AML_INTERNAL);

                }

                /* An additional reference for the attached objects */

                acpi_ut_add_reference (obj_desc->index_field.data_obj);

                acpi_ut_add_reference (obj_desc->index_field.index_obj);

                ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,

                        "index_field: bit_off %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",

                        obj_desc->index_field.start_field_bit_offset,

                        obj_desc->index_field.base_byte_offset,

                        obj_desc->index_field.value,

                        obj_desc->field.access_byte_width,

                        obj_desc->index_field.index_obj,

                        obj_desc->index_field.data_obj));

                break;

        default:

                /* No other types should get here */

                break;

        }

        /*

         * Store the constructed descriptor (obj_desc) into the parent Node,

         * preserving the current type of that named_obj.

         */

        status = acpi_ns_attach_object (info->field_node, obj_desc,

                          acpi_ns_get_type (info->field_node));

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Set named_obj %p [%4.4s], obj_desc %p\n",

                        info->field_node, acpi_ut_get_node_name (info->field_node), obj_desc));

        /* Remove local reference to the object */

        acpi_ut_remove_reference (obj_desc);

        return_ACPI_STATUS (status);

}