exfield.c

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

/*
 * 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 "acdispat.h"
#include "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;
    u32 function;

    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 (obj_desc->common.type == 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 ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
           (obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_SMBUS
            || obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_GSBUS
            || obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_IPMI)) {
        /*
         * This is an SMBus, GSBus or IPMI read. We must create a buffer to hold
         * the data and then directly access the region handler.
         *
         * Note: SMBus and GSBus protocol value is passed in upper 16-bits of Function
         */
        if (obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_SMBUS) {
            length = ACPI_SMBUS_BUFFER_SIZE;
            function =
                ACPI_READ | (obj_desc->field.attribute << 16);
        } else if (obj_desc->field.region_obj->region.space_id ==
               ACPI_ADR_SPACE_GSBUS) {
            length = ACPI_GSBUS_BUFFER_SIZE;
            function =
                ACPI_READ | (obj_desc->field.attribute << 16);
        } else {    /* IPMI */

            length = ACPI_IPMI_BUFFER_SIZE;
            function = ACPI_READ;
        }

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

        /* Lock entire transaction if requested */

        acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

        /* Call the region handler for the read */

        status = acpi_ex_access_region(obj_desc, 0,
                           ACPI_CAST_PTR(u64,
                                 buffer_desc->
                                 buffer.pointer),
                           function);
        acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
        goto exit;
    }

    /*
     * Allocate a buffer for the contents of the field.
     *
     * If the field is larger than the current integer width, 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_integer_object((u64) 0);
        if (!buffer_desc) {
            return_ACPI_STATUS(AE_NO_MEMORY);
        }

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

    ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
              "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
              obj_desc, obj_desc->common.type, 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 */

    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(obj_desc->common_field.field_flags);

      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;
    void *buffer;
    union acpi_operand_object *buffer_desc;
    u32 function;

    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 (obj_desc->common.type == 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 ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
           (obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_SMBUS
            || obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_GSBUS
            || obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_IPMI)) {
        /*
         * This is an SMBus, GSBus or IPMI write. We will bypass the entire field
         * mechanism and handoff the buffer directly to the handler. For
         * these address spaces, the buffer is bi-directional; on a write,
         * return data is returned in the same buffer.
         *
         * Source must be a buffer of sufficient size:
         * ACPI_SMBUS_BUFFER_SIZE, ACPI_GSBUS_BUFFER_SIZE, or ACPI_IPMI_BUFFER_SIZE.
         *
         * Note: SMBus and GSBus protocol type is passed in upper 16-bits of Function
         */
        if (source_desc->common.type != ACPI_TYPE_BUFFER) {
            ACPI_ERROR((AE_INFO,
                    "SMBus/IPMI/GenericSerialBus write requires Buffer, found type %s",
                    acpi_ut_get_object_type_name(source_desc)));

            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
        }

        if (obj_desc->field.region_obj->region.space_id ==
            ACPI_ADR_SPACE_SMBUS) {
            length = ACPI_SMBUS_BUFFER_SIZE;
            function =
                ACPI_WRITE | (obj_desc->field.attribute << 16);
        } else if (obj_desc->field.region_obj->region.space_id ==
               ACPI_ADR_SPACE_GSBUS) {
            length = ACPI_GSBUS_BUFFER_SIZE;
            function =
                ACPI_WRITE | (obj_desc->field.attribute << 16);
        } else {    /* IPMI */

            length = ACPI_IPMI_BUFFER_SIZE;
            function = ACPI_WRITE;
        }

        if (source_desc->buffer.length < length) {
            ACPI_ERROR((AE_INFO,
                    "SMBus/IPMI/GenericSerialBus write requires Buffer of length %u, found length %u",
                    length, source_desc->buffer.length));

            return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
        }

        /* Create the bi-directional buffer */

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

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

        /* Lock entire transaction if requested */

        acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

        /*
         * Perform the write (returns status and perhaps data in the
         * same buffer)
         */
        status = acpi_ex_access_region(obj_desc, 0,
                           (u64 *) buffer, function);
        acpi_ex_release_global_lock(obj_desc->common_field.field_flags);

        *result_desc = buffer_desc;
        return_ACPI_STATUS(status);
    }

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

    switch (source_desc->common.type) {
    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);
    }

    ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
              "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
              source_desc,
              acpi_ut_get_type_name(source_desc->common.type),
              source_desc->common.type, 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(obj_desc->common.type),
              obj_desc->common.type,
              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 */

    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(obj_desc->common_field.field_flags);

    return_ACPI_STATUS(status);
}