exprep.c

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

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * 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 "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)
     */
    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,
                      "AccessWidth %u end is within region\n",
                      access_byte_width));

            ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                      "Field Start %u, Field End %u -- requires %u 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 %u\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,
                      "AccessWidth %u 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"));

                /* Field does not fit in the region at all */

                return_VALUE(0);
            }

            /*
             * 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 %u\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:  obj_desc            - Field object
 *              field_flags         - Encoded fieldflags (contains access bits)
 *              return_byte_alignment - Where the byte alignment is returned
 *
 * 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 parameter */
            );
        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_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
        return_UINT32(0);
    }

    if (obj_desc->common.type == 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_UINT32(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_attribute     - Special attributes (not used)
 *              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 (values are: 1, 2, 4, 8) */

    obj_desc->common_field.access_byte_width = (u8)
        ACPI_DIV_8(access_bit_width);

    /*
     * 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));

    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_prep_field_value
 *
 * PARAMETERS:  info    - Contains all field creation info
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Construct an object of type union acpi_operand_object with a
 *              subtype of 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;
    union acpi_operand_object *second_desc = NULL;
    acpi_status status;
    u32 access_byte_width;
    u32 type;

    ACPI_FUNCTION_TRACE(ex_prep_field_value);

    /* Parameter validation */

    if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
        if (!info->region_node) {
            ACPI_ERROR((AE_INFO, "Null RegionNode"));
            return_ACPI_STATUS(AE_AML_NO_OPERAND);
        }

        type = acpi_ns_get_type(info->region_node);
        if (type != ACPI_TYPE_REGION) {
            ACPI_ERROR((AE_INFO,
                    "Needed Region, found type 0x%X (%s)", 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);

        /* Fields specific to generic_serial_bus fields */

        obj_desc->field.access_length = info->access_length;

        if (info->connection_node) {
            second_desc = info->connection_node->object;
            if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
                status =
                    acpi_ds_get_buffer_arguments(second_desc);
                if (ACPI_FAILURE(status)) {
                    acpi_ut_delete_object_desc(obj_desc);
                    return_ACPI_STATUS(status);
                }
            }

            obj_desc->field.resource_buffer =
                second_desc->buffer.pointer;
            obj_desc->field.resource_length =
                (u16)second_desc->buffer.length;
        } else if (info->resource_buffer) {
            obj_desc->field.resource_buffer = info->resource_buffer;
            obj_desc->field.resource_length = info->resource_length;
        }

        /* Allow full data read from EC address space */

        if ((obj_desc->field.region_obj->region.space_id ==
             ACPI_ADR_SPACE_EC)
            && (obj_desc->common_field.bit_length > 8)) {
            access_byte_width =
                ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
                            bit_length);

            /* Maximum byte width supported is 255 */

            if (access_byte_width < 256) {
                obj_desc->common_field.access_byte_width =
                    (u8)access_byte_width;
            }
        }
        /* An additional reference for the container */

        acpi_ut_add_reference(obj_desc->field.region_obj);

        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                  "RegionField: BitOff %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: BitOff %X, Off %X, Gran %X, Region %p, BankReg %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));

        /*
         * Remember location in AML stream of the field unit
         * opcode and operands -- since the bank_value
         * operands must be evaluated.
         */
        second_desc = obj_desc->common.next_object;
        second_desc->extra.aml_start =
            ACPI_CAST_PTR(union acpi_parse_object,
                  info->data_register_node)->named.data;
        second_desc->extra.aml_length =
            ACPI_CAST_PTR(union acpi_parse_object,
                  info->data_register_node)->named.length;

        break;

    case ACPI_TYPE_LOCAL_INDEX_FIELD:

        /* Get the Index and Data registers */

        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);

        if (!obj_desc->index_field.data_obj
            || !obj_desc->index_field.index_obj) {
            ACPI_ERROR((AE_INFO,
                    "Null Index Object during field prep"));
            acpi_ut_delete_object_desc(obj_desc);
            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);

        /*
         * April 2006: Changed to match MS behavior
         *
         * The value written to the Index register is the byte offset of the
         * target field in units of the granularity of the index_field
         *
         * Previously, the value was calculated as an index in terms of the
         * width of the Data register, as below:
         *
         *      obj_desc->index_field.Value = (u32)
         *          (Info->field_bit_position / ACPI_MUL_8 (
         *              obj_desc->Field.access_byte_width));
         *
         * February 2006: Tried value as a byte offset:
         *      obj_desc->index_field.Value = (u32)
         *          ACPI_DIV_8 (Info->field_bit_position);
         */
        obj_desc->index_field.value =
            (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
                      obj_desc->index_field.
                      access_byte_width);

        ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
                  "IndexField: BitOff %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 NamedObj %p [%4.4s], ObjDesc %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);
}