linux-imx

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0

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

 *

 * Module Name: exprep - ACPI AML field prep utilities

 *

 * Copyright (C) 2000 - 2019, Intel Corp.

 *

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

​

#include <acpi/acpi.h>

#include "accommon.h"

#include "acinterp.h"

#include "amlcode.h"

#include "acnamesp.h"

#include "acdispat.h"

​

#define _COMPONENT          ACPI_EXECUTER

ACPI_MODULE_NAME("exprep")

​

/* Local prototypes */

static u32

acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,

                u8 field_flags, u32 * return_byte_alignment);

​

#ifdef ACPI_UNDER_DEVELOPMENT

​

static u32

acpi_ex_generate_access(u32 field_bit_offset,

            u32 field_bit_length, u32 region_length);

​

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

 *

 * 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 %u, Bit offset %u\n",

              field_bit_length, field_bit_offset));

​

    ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,

              "Byte Length %u, Byte Offset %u, End Offset %u\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)

     */