psparse.c

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/******************************************************************************
 *
 * Module Name: psparse - Parser top level AML parse routines
 *
 *****************************************************************************/

/*
 * 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.
 */

/*
 * Parse the AML and build an operation tree as most interpreters,
 * like Perl, do.  Parsing is done by hand rather than with a YACC
 * generated parser to tightly constrain stack and dynamic memory
 * usage.  At the same time, parsing is kept flexible and the code
 * fairly compact by parsing based on a list of AML opcode
 * templates in aml_op_info[]
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"
#include "acdispat.h"
#include "amlcode.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("psparse")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_opcode_size
 *
 * PARAMETERS:  opcode          - An AML opcode
 *
 * RETURN:      Size of the opcode, in bytes (1 or 2)
 *
 * DESCRIPTION: Get the size of the current opcode.
 *
 ******************************************************************************/
u32 acpi_ps_get_opcode_size(u32 opcode)
{

    /* Extended (2-byte) opcode if > 255 */

    if (opcode > 0x00FF) {
        return (2);
    }

    /* Otherwise, just a single byte opcode */

    return (1);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_peek_opcode
 *
 * PARAMETERS:  parser_state        - A parser state object
 *
 * RETURN:      Next AML opcode
 *
 * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
 *
 ******************************************************************************/

u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
{
    u8 *aml;
    u16 opcode;

    aml = parser_state->aml;
    opcode = (u16) ACPI_GET8(aml);

    if (opcode == AML_EXTENDED_OP_PREFIX) {

        /* Extended opcode, get the second opcode byte */

        aml++;
        opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
    }

    return (opcode);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_complete_this_op
 *
 * PARAMETERS:  walk_state      - Current State
 *              op              - Op to complete
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform any cleanup at the completion of an Op.
 *
 ******************************************************************************/

acpi_status
acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
             union acpi_parse_object * op)
{
    union acpi_parse_object *prev;
    union acpi_parse_object *next;
    const struct acpi_opcode_info *parent_info;
    union acpi_parse_object *replacement_op = NULL;
    acpi_status status = AE_OK;

    ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);

    /* Check for null Op, can happen if AML code is corrupt */

    if (!op) {
        return_ACPI_STATUS(AE_OK);  /* OK for now */
    }

    /* Delete this op and the subtree below it if asked to */

    if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
         ACPI_PARSE_DELETE_TREE)
        || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
        return_ACPI_STATUS(AE_OK);
    }

    /* Make sure that we only delete this subtree */

    if (op->common.parent) {
        prev = op->common.parent->common.value.arg;
        if (!prev) {

            /* Nothing more to do */

            goto cleanup;
        }

        /*
         * Check if we need to replace the operator and its subtree
         * with a return value op (placeholder op)
         */
        parent_info =
            acpi_ps_get_opcode_info(op->common.parent->common.
                        aml_opcode);

        switch (parent_info->class) {
        case AML_CLASS_CONTROL:
            break;

        case AML_CLASS_CREATE:

            /*
             * These opcodes contain term_arg operands. The current
             * op must be replaced by a placeholder return op
             */
            replacement_op =
                acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
            if (!replacement_op) {
                status = AE_NO_MEMORY;
            }
            break;

        case AML_CLASS_NAMED_OBJECT:

            /*
             * These opcodes contain term_arg operands. The current
             * op must be replaced by a placeholder return op
             */
            if ((op->common.parent->common.aml_opcode ==
                 AML_REGION_OP)
                || (op->common.parent->common.aml_opcode ==
                AML_DATA_REGION_OP)
                || (op->common.parent->common.aml_opcode ==
                AML_BUFFER_OP)
                || (op->common.parent->common.aml_opcode ==
                AML_PACKAGE_OP)
                || (op->common.parent->common.aml_opcode ==
                AML_BANK_FIELD_OP)
                || (op->common.parent->common.aml_opcode ==
                AML_VAR_PACKAGE_OP)) {
                replacement_op =
                    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
                if (!replacement_op) {
                    status = AE_NO_MEMORY;
                }
            } else
                if ((op->common.parent->common.aml_opcode ==
                 AML_NAME_OP)
                && (walk_state->pass_number <=
                    ACPI_IMODE_LOAD_PASS2)) {
                if ((op->common.aml_opcode == AML_BUFFER_OP)
                    || (op->common.aml_opcode == AML_PACKAGE_OP)
                    || (op->common.aml_opcode ==
                    AML_VAR_PACKAGE_OP)) {
                    replacement_op =
                        acpi_ps_alloc_op(op->common.
                                 aml_opcode);
                    if (!replacement_op) {
                        status = AE_NO_MEMORY;
                    } else {
                        replacement_op->named.data =
                            op->named.data;
                        replacement_op->named.length =
                            op->named.length;
                    }
                }
            }
            break;

        default:

            replacement_op =
                acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
            if (!replacement_op) {
                status = AE_NO_MEMORY;
            }
        }

        /* We must unlink this op from the parent tree */

        if (prev == op) {

            /* This op is the first in the list */

            if (replacement_op) {
                replacement_op->common.parent =
                    op->common.parent;
                replacement_op->common.value.arg = NULL;
                replacement_op->common.node = op->common.node;
                op->common.parent->common.value.arg =
                    replacement_op;
                replacement_op->common.next = op->common.next;
            } else {
                op->common.parent->common.value.arg =
                    op->common.next;
            }
        }

        /* Search the parent list */

        else
            while (prev) {

                /* Traverse all siblings in the parent's argument list */

                next = prev->common.next;
                if (next == op) {
                    if (replacement_op) {
                        replacement_op->common.parent =
                            op->common.parent;
                        replacement_op->common.value.
                            arg = NULL;
                        replacement_op->common.node =
                            op->common.node;
                        prev->common.next =
                            replacement_op;
                        replacement_op->common.next =
                            op->common.next;
                        next = NULL;
                    } else {
                        prev->common.next =
                            op->common.next;
                        next = NULL;
                    }
                }
                prev = next;
            }
    }

      cleanup:

    /* Now we can actually delete the subtree rooted at Op */

    acpi_ps_delete_parse_tree(op);
    return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_next_parse_state
 *
 * PARAMETERS:  walk_state          - Current state
 *              op                  - Current parse op
 *              callback_status     - Status from previous operation
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Update the parser state based upon the return exception from
 *              the parser callback.
 *
 ******************************************************************************/

acpi_status
acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
             union acpi_parse_object *op,
             acpi_status callback_status)
{
    struct acpi_parse_state *parser_state = &walk_state->parser_state;
    acpi_status status = AE_CTRL_PENDING;

    ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);

    switch (callback_status) {
    case AE_CTRL_TERMINATE:
        /*
         * A control method was terminated via a RETURN statement.
         * The walk of this method is complete.
         */
        parser_state->aml = parser_state->aml_end;
        status = AE_CTRL_TERMINATE;
        break;

    case AE_CTRL_BREAK:

        parser_state->aml = walk_state->aml_last_while;
        walk_state->control_state->common.value = FALSE;
        status = AE_CTRL_BREAK;
        break;

    case AE_CTRL_CONTINUE:

        parser_state->aml = walk_state->aml_last_while;
        status = AE_CTRL_CONTINUE;
        break;

    case AE_CTRL_PENDING:

        parser_state->aml = walk_state->aml_last_while;
        break;

#if 0
    case AE_CTRL_SKIP:

        parser_state->aml = parser_state->scope->parse_scope.pkg_end;
        status = AE_OK;
        break;
#endif

    case AE_CTRL_TRUE:
        /*
         * Predicate of an IF was true, and we are at the matching ELSE.
         * Just close out this package
         */
        parser_state->aml = acpi_ps_get_next_package_end(parser_state);
        status = AE_CTRL_PENDING;
        break;

    case AE_CTRL_FALSE:
        /*
         * Either an IF/WHILE Predicate was false or we encountered a BREAK
         * opcode.  In both cases, we do not execute the rest of the
         * package;  We simply close out the parent (finishing the walk of
         * this branch of the tree) and continue execution at the parent
         * level.
         */
        parser_state->aml = parser_state->scope->parse_scope.pkg_end;

        /* In the case of a BREAK, just force a predicate (if any) to FALSE */

        walk_state->control_state->common.value = FALSE;
        status = AE_CTRL_END;
        break;

    case AE_CTRL_TRANSFER:

        /* A method call (invocation) -- transfer control */

        status = AE_CTRL_TRANSFER;
        walk_state->prev_op = op;
        walk_state->method_call_op = op;
        walk_state->method_call_node =
            (op->common.value.arg)->common.node;

        /* Will return value (if any) be used by the caller? */

        walk_state->return_used =
            acpi_ds_is_result_used(op, walk_state);
        break;

    default:

        status = callback_status;
        if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
            status = AE_OK;
        }
        break;
    }

    return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_parse_aml
 *
 * PARAMETERS:  walk_state      - Current state
 *
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Parse raw AML and return a tree of ops
 *
 ******************************************************************************/

acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
{
    acpi_status status;
    struct acpi_thread_state *thread;
    struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
    struct acpi_walk_state *previous_walk_state;

    ACPI_FUNCTION_TRACE(ps_parse_aml);

    ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
              "Entered with WalkState=%p Aml=%p size=%X\n",
              walk_state, walk_state->parser_state.aml,
              walk_state->parser_state.aml_size));

    if (!walk_state->parser_state.aml) {
        return_ACPI_STATUS(AE_NULL_OBJECT);
    }

    /* Create and initialize a new thread state */

    thread = acpi_ut_create_thread_state();
    if (!thread) {
        if (walk_state->method_desc) {

            /* Executing a control method - additional cleanup */

            acpi_ds_terminate_control_method(
                walk_state->method_desc, walk_state);
        }

        acpi_ds_delete_walk_state(walk_state);
        return_ACPI_STATUS(AE_NO_MEMORY);
    }

    walk_state->thread = thread;

    /*
     * If executing a method, the starting sync_level is this method's
     * sync_level
     */
    if (walk_state->method_desc) {
        walk_state->thread->current_sync_level =
            walk_state->method_desc->method.sync_level;
    }

    acpi_ds_push_walk_state(walk_state, thread);

    /*
     * This global allows the AML debugger to get a handle to the currently
     * executing control method.
     */
    acpi_gbl_current_walk_list = thread;

    /*
     * Execute the walk loop as long as there is a valid Walk State.  This
     * handles nested control method invocations without recursion.
     */
    ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));

    status = AE_OK;
    while (walk_state) {
        if (ACPI_SUCCESS(status)) {
            /*
             * The parse_loop executes AML until the method terminates
             * or calls another method.
             */
            status = acpi_ps_parse_loop(walk_state);
        }

        ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
                  "Completed one call to walk loop, %s State=%p\n",
                  acpi_format_exception(status), walk_state));

        if (status == AE_CTRL_TRANSFER) {
            /*
             * A method call was detected.
             * Transfer control to the called control method
             */
            status =
                acpi_ds_call_control_method(thread, walk_state,
                            NULL);
            if (ACPI_FAILURE(status)) {
                status =
                    acpi_ds_method_error(status, walk_state);
            }

            /*
             * If the transfer to the new method method call worked, a new walk
             * state was created -- get it
             */
            walk_state = acpi_ds_get_current_walk_state(thread);
            continue;
        } else if (status == AE_CTRL_TERMINATE) {
            status = AE_OK;
        } else if ((status != AE_OK) && (walk_state->method_desc)) {

            /* Either the method parse or actual execution failed */

            ACPI_ERROR_METHOD("Method parse/execution failed",
                      walk_state->method_node, NULL,
                      status);

            /* Check for possible multi-thread reentrancy problem */

            if ((status == AE_ALREADY_EXISTS) &&
                (!(walk_state->method_desc->method.
                   info_flags & ACPI_METHOD_SERIALIZED))) {
                /*
                 * Method is not serialized and tried to create an object
                 * twice. The probable cause is that the method cannot
                 * handle reentrancy. Mark as "pending serialized" now, and
                 * then mark "serialized" when the last thread exits.
                 */
                walk_state->method_desc->method.info_flags |=
                    ACPI_METHOD_SERIALIZED_PENDING;
            }
        }

        /* We are done with this walk, move on to the parent if any */

        walk_state = acpi_ds_pop_walk_state(thread);

        /* Reset the current scope to the beginning of scope stack */

        acpi_ds_scope_stack_clear(walk_state);

        /*
         * If we just returned from the execution of a control method or if we
         * encountered an error during the method parse phase, there's lots of
         * cleanup to do
         */
        if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
             ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
            acpi_ds_terminate_control_method(walk_state->
                             method_desc,
                             walk_state);
        }

        /* Delete this walk state and all linked control states */

        acpi_ps_cleanup_scope(&walk_state->parser_state);
        previous_walk_state = walk_state;

        ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
                  "ReturnValue=%p, ImplicitValue=%p State=%p\n",
                  walk_state->return_desc,
                  walk_state->implicit_return_obj, walk_state));

        /* Check if we have restarted a preempted walk */

        walk_state = acpi_ds_get_current_walk_state(thread);
        if (walk_state) {
            if (ACPI_SUCCESS(status)) {
                /*
                 * There is another walk state, restart it.
                 * If the method return value is not used by the parent,
                 * The object is deleted
                 */
                if (!previous_walk_state->return_desc) {
                    /*
                     * In slack mode execution, if there is no return value
                     * we should implicitly return zero (0) as a default value.
                     */
                    if (acpi_gbl_enable_interpreter_slack &&
                        !previous_walk_state->
                        implicit_return_obj) {
                        previous_walk_state->
                            implicit_return_obj =
                            acpi_ut_create_integer_object
                            ((u64) 0);
                        if (!previous_walk_state->
                            implicit_return_obj) {
                            return_ACPI_STATUS
                                (AE_NO_MEMORY);
                        }
                    }

                    /* Restart the calling control method */

                    status =
                        acpi_ds_restart_control_method
                        (walk_state,
                         previous_walk_state->
                         implicit_return_obj);
                } else {
                    /*
                     * We have a valid return value, delete any implicit
                     * return value.
                     */
                    acpi_ds_clear_implicit_return
                        (previous_walk_state);

                    status =
                        acpi_ds_restart_control_method
                        (walk_state,
                         previous_walk_state->return_desc);
                }
                if (ACPI_SUCCESS(status)) {
                    walk_state->walk_type |=
                        ACPI_WALK_METHOD_RESTART;
                }
            } else {
                /* On error, delete any return object or implicit return */

                acpi_ut_remove_reference(previous_walk_state->
                             return_desc);
                acpi_ds_clear_implicit_return
                    (previous_walk_state);
            }
        }

        /*
         * Just completed a 1st-level method, save the final internal return
         * value (if any)
         */
        else if (previous_walk_state->caller_return_desc) {
            if (previous_walk_state->implicit_return_obj) {
                *(previous_walk_state->caller_return_desc) =
                    previous_walk_state->implicit_return_obj;
            } else {
                /* NULL if no return value */

                *(previous_walk_state->caller_return_desc) =
                    previous_walk_state->return_desc;
            }
        } else {
            if (previous_walk_state->return_desc) {

                /* Caller doesn't want it, must delete it */

                acpi_ut_remove_reference(previous_walk_state->
                             return_desc);
            }
            if (previous_walk_state->implicit_return_obj) {

                /* Caller doesn't want it, must delete it */

                acpi_ut_remove_reference(previous_walk_state->
                             implicit_return_obj);
            }
        }

        acpi_ds_delete_walk_state(previous_walk_state);
    }

    /* Normal exit */

    acpi_ex_release_all_mutexes(thread);
    acpi_ut_delete_generic_state(ACPI_CAST_PTR
                     (union acpi_generic_state, thread));
    acpi_gbl_current_walk_list = prev_walk_list;
    return_ACPI_STATUS(status);
}