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

 *

 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing

 *

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

/*

 * 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/acparser.h>

#include <acpi/amlcode.h>

#include <acpi/acdispat.h>

#include <acpi/acinterp.h>

#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_DISPATCHER

         ACPI_MODULE_NAME    ("dsmethod")

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

 *

 * FUNCTION:    acpi_ds_parse_method

 *

 * PARAMETERS:  obj_handle      - Node of the method

 *              Level           - Current nesting level

 *              Context         - Points to a method counter

 *              return_value    - Not used

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Call the parser and parse the AML that is

 *              associated with the method.

 *

 * MUTEX:       Assumes parser is locked

 *

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

acpi_status

acpi_ds_parse_method (

        acpi_handle                     obj_handle)

{

        acpi_status                     status;

        union acpi_operand_object       *obj_desc;

        union acpi_parse_object         *op;

        struct acpi_namespace_node      *node;

        acpi_owner_id                   owner_id;

        struct acpi_walk_state          *walk_state;

        ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", obj_handle);

        /* Parameter Validation */

        if (!obj_handle) {

                return_ACPI_STATUS (AE_NULL_ENTRY);

        }

        ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "**** Parsing [%4.4s] **** named_obj=%p\n",

                acpi_ut_get_node_name (obj_handle), obj_handle));

        /* Extract the method object from the method Node */

        node = (struct acpi_namespace_node *) obj_handle;

        obj_desc = acpi_ns_get_attached_object (node);

        if (!obj_desc) {

                return_ACPI_STATUS (AE_NULL_OBJECT);

        }

        /* Create a mutex for the method if there is a concurrency limit */

        if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&

                (!obj_desc->method.semaphore)) {

                status = acpi_os_create_semaphore (obj_desc->method.concurrency,

                                   obj_desc->method.concurrency,

                                   &obj_desc->method.semaphore);

                if (ACPI_FAILURE (status)) {

                        return_ACPI_STATUS (status);

                }

        }

        /*

         * Allocate a new parser op to be the root of the parsed

         * method tree

         */

        op = acpi_ps_alloc_op (AML_METHOD_OP);

        if (!op) {

                return_ACPI_STATUS (AE_NO_MEMORY);

        }

        /* Init new op with the method name and pointer back to the Node */

        acpi_ps_set_name (op, node->name.integer);

        op->common.node = node;

        /*

         * Get a new owner_id for objects created by this method. Namespace

         * objects (such as Operation Regions) can be created during the

         * first pass parse.

         */

        owner_id = acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD);

        obj_desc->method.owning_id = owner_id;

        /* Create and initialize a new walk state */

        walk_state = acpi_ds_create_walk_state (owner_id, NULL, NULL, NULL);

        if (!walk_state) {

                return_ACPI_STATUS (AE_NO_MEMORY);

        }

        status = acpi_ds_init_aml_walk (walk_state, op, node, obj_desc->method.aml_start,

                          obj_desc->method.aml_length, NULL, NULL, 1);

        if (ACPI_FAILURE (status)) {

                acpi_ds_delete_walk_state (walk_state);

                return_ACPI_STATUS (status);

        }

        /*

         * Parse the method, first pass

         *

         * The first pass load is where newly declared named objects are

         * added into the namespace.  Actual evaluation of

         * the named objects (what would be called a "second

         * pass") happens during the actual execution of the

         * method so that operands to the named objects can

         * take on dynamic run-time values.

         */

        status = acpi_ps_parse_aml (walk_state);

        if (ACPI_FAILURE (status)) {

                return_ACPI_STATUS (status);

        }

        ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,

                "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",

                acpi_ut_get_node_name (obj_handle), obj_handle, op));

        acpi_ps_delete_parse_tree (op);

        return_ACPI_STATUS (status);

}

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

 *

 * FUNCTION:    acpi_ds_begin_method_execution

 *

 * PARAMETERS:  method_node         - Node of the method

 *              obj_desc            - The method object

 *              calling_method_node - Caller of this method (if non-null)

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,

 *              increments the thread count, and waits at the method semaphore

 *              for clearance to execute.

 *

 * MUTEX:       Locks/unlocks parser.

 *

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

acpi_status

acpi_ds_begin_method_execution (

        struct acpi_namespace_node      *method_node,

        union acpi_operand_object       *obj_desc,

        struct acpi_namespace_node      *calling_method_node)

{

        acpi_status                     status = AE_OK;

        ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);

        if (!method_node) {

                return_ACPI_STATUS (AE_NULL_ENTRY);

        }

        /*

         * If there is a concurrency limit on this method, we need to

         * obtain a unit from the method semaphore.

         */

        if (obj_desc->method.semaphore) {

                /*

                 * Allow recursive method calls, up to the reentrancy/concurrency

                 * limit imposed by the SERIALIZED rule and the sync_level method

                 * parameter.

                 *

                 * The point of this code is to avoid permanently blocking a

                 * thread that is making recursive method calls.

                 */

                if (method_node == calling_method_node) {

                        if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {

                                return_ACPI_STATUS (AE_AML_METHOD_LIMIT);

                        }

                }

                /*

                 * Get a unit from the method semaphore. This releases the

                 * interpreter if we block

                 */

                status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,

                                 ACPI_WAIT_FOREVER);

        }

        /*

         * Increment the method parse tree thread count since it has been

         * reentered one more time (even if it is the same thread)

         */

        obj_desc->method.thread_count++;

        return_ACPI_STATUS (status);

}

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

 *

 * FUNCTION:    acpi_ds_call_control_method

 *

 * PARAMETERS:  walk_state          - Current state of the walk

 *              Op                  - Current Op to be walked

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Transfer execution to a called control method

 *

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

acpi_status

acpi_ds_call_control_method (

        struct acpi_thread_state        *thread,

        struct acpi_walk_state          *this_walk_state,

        union acpi_parse_object         *op)

{

        acpi_status                     status;

        struct acpi_namespace_node      *method_node;

        union acpi_operand_object       *obj_desc;

        struct acpi_walk_state          *next_walk_state;

        u32                             i;

        ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);

        ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Execute method %p, currentstate=%p\n",

                this_walk_state->prev_op, this_walk_state));

        /*

         * Get the namespace entry for the control method we are about to call

         */

        method_node = this_walk_state->method_call_node;

        if (!method_node) {

                return_ACPI_STATUS (AE_NULL_ENTRY);

        }

        obj_desc = acpi_ns_get_attached_object (method_node);

        if (!obj_desc) {

                return_ACPI_STATUS (AE_NULL_OBJECT);

        }

        obj_desc->method.owning_id = acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD);

        /* Init for new method, wait on concurrency semaphore */

        status = acpi_ds_begin_method_execution (method_node, obj_desc,

                          this_walk_state->method_node);

        if (ACPI_FAILURE (status)) {

                return_ACPI_STATUS (status);

        }

        if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {

                /* 1) Parse: Create a new walk state for the preempting walk */

                next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,

                                  op, obj_desc, NULL);

                if (!next_walk_state) {

                        return_ACPI_STATUS (AE_NO_MEMORY);

                }

                /* Create and init a Root Node */

                op = acpi_ps_create_scope_op ();

                if (!op) {

                        status = AE_NO_MEMORY;

                        goto cleanup;

                }

                status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,

                                  obj_desc->method.aml_start, obj_desc->method.aml_length,

                                  NULL, NULL, 1);

                if (ACPI_FAILURE (status)) {

                        acpi_ds_delete_walk_state (next_walk_state);

                        goto cleanup;

                }

                /* Begin AML parse */

                status = acpi_ps_parse_aml (next_walk_state);

                acpi_ps_delete_parse_tree (op);

        }

        /* 2) Execute: Create a new state for the preempting walk */

        next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,

                          NULL, obj_desc, thread);

        if (!next_walk_state) {

                status = AE_NO_MEMORY;

                goto cleanup;

        }

        /*

         * The resolved arguments were put on the previous walk state's operand

         * stack.  Operands on the previous walk state stack always

         * start at index 0.

         * Null terminate the list of arguments

         */

        this_walk_state->operands [this_walk_state->num_operands] = NULL;

        status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,

                          obj_desc->method.aml_start, obj_desc->method.aml_length,

                          &this_walk_state->operands[0], NULL, 3);

        if (ACPI_FAILURE (status)) {

                goto cleanup;

        }

        /*

         * Delete the operands on the previous walkstate operand stack

         * (they were copied to new objects)

         */

        for (i = 0; i < obj_desc->method.param_count; i++) {

                acpi_ut_remove_reference (this_walk_state->operands [i]);

                this_walk_state->operands [i] = NULL;

        }

        /* Clear the operand stack */

        this_walk_state->num_operands = 0;

        ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

                "Starting nested execution, newstate=%p\n", next_walk_state));

        if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {

                status = obj_desc->method.implementation (next_walk_state);

                return_ACPI_STATUS (status);

        }

        return_ACPI_STATUS (AE_OK);

        /* On error, we must delete the new walk state */

cleanup:

        if (next_walk_state->method_desc) {

                /* Decrement the thread count on the method parse tree */

           next_walk_state->method_desc->method.thread_count--;

        }

        (void) acpi_ds_terminate_control_method (next_walk_state);

        acpi_ds_delete_walk_state (next_walk_state);

        return_ACPI_STATUS (status);

}

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

 *

 * FUNCTION:    acpi_ds_restart_control_method

 *

 * PARAMETERS:  walk_state          - State of the method when it was preempted

 *              Op                  - Pointer to new current op

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Restart a method that was preempted

 *

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

acpi_status

acpi_ds_restart_control_method (

        struct acpi_walk_state          *walk_state,

        union acpi_operand_object       *return_desc)

{

        acpi_status                     status;

        ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);

        if (return_desc) {

                if (walk_state->return_used) {

                        /*

                         * Get the return value (if any) from the previous method.

                         * NULL if no return value

                         */

                        status = acpi_ds_result_push (return_desc, walk_state);

                        if (ACPI_FAILURE (status)) {

                                acpi_ut_remove_reference (return_desc);

                                return_ACPI_STATUS (status);

                        }

                }

                else {

                        /*

                         * Delete the return value if it will not be used by the

                         * calling method

                         */

                        acpi_ut_remove_reference (return_desc);

                }

        }

        ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

                "Method=%p Return=%p return_used?=%X res_stack=%p State=%p\n",

                walk_state->method_call_op, return_desc, walk_state->return_used,

                walk_state->results, walk_state));

        return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    acpi_ds_terminate_control_method

 *

 * PARAMETERS:  walk_state          - State of the method

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Terminate a control method.  Delete everything that the method

 *              created, delete all locals and arguments, and delete the parse

 *              tree if requested.

 *

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

acpi_status

acpi_ds_terminate_control_method (

        struct acpi_walk_state          *walk_state)

{

        union acpi_operand_object       *obj_desc;

        struct acpi_namespace_node      *method_node;

        acpi_status                     status;

        ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);

        if (!walk_state) {

                return (AE_BAD_PARAMETER);

        }

        /* The current method object was saved in the walk state */

        obj_desc = walk_state->method_desc;

        if (!obj_desc) {

                return_ACPI_STATUS (AE_OK);

        }

        /* Delete all arguments and locals */

        acpi_ds_method_data_delete_all (walk_state);

        /*

         * Lock the parser while we terminate this method.

         * If this is the last thread executing the method,

         * we have additional cleanup to perform

         */

        status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);

        if (ACPI_FAILURE (status)) {

                return_ACPI_STATUS (status);

        }

        /* Signal completion of the execution of this method if necessary */

        if (walk_state->method_desc->method.semaphore) {

                status = acpi_os_signal_semaphore (

                                  walk_state->method_desc->method.semaphore, 1);

                if (ACPI_FAILURE (status)) {

                        ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));

                        status = AE_OK;

                        /* Ignore error and continue cleanup */

                }

        }

        if (walk_state->method_desc->method.thread_count) {

                ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

                        "*** Not deleting method namespace, there are still %d threads\n",

                        walk_state->method_desc->method.thread_count));

        }

        if (!walk_state->method_desc->method.thread_count) {

                /*

                 * Support to dynamically change a method from not_serialized to

                 * Serialized if it appears that the method is written foolishly and

                 * does not support multiple thread execution.  The best example of this

                 * is if such a method creates namespace objects and blocks.  A second

                 * thread will fail with an AE_ALREADY_EXISTS exception

                 *

                 * This code is here because we must wait until the last thread exits

                 * before creating the synchronization semaphore.

                 */

                if ((walk_state->method_desc->method.concurrency == 1) &&

                        (!walk_state->method_desc->method.semaphore)) {

                        status = acpi_os_create_semaphore (1,

                                         1,

                                         &walk_state->method_desc->method.semaphore);

                }

                /*

                 * There are no more threads executing this method.  Perform

                 * additional cleanup.

                 *

                 * The method Node is stored in the walk state

                 */

                method_node = walk_state->method_node;

                /*

                 * Delete any namespace entries created immediately underneath

                 * the method

                 */

                status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);

                if (ACPI_FAILURE (status)) {

                        return_ACPI_STATUS (status);

                }

                if (method_node->child) {

                        acpi_ns_delete_namespace_subtree (method_node);

                }

                /*

                 * Delete any namespace entries created anywhere else within

                 * the namespace

                 */

                acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owning_id);

                status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);

                if (ACPI_FAILURE (status)) {

                        return_ACPI_STATUS (status);

                }

        }

        status = acpi_ut_release_mutex (ACPI_MTX_PARSER);

        return_ACPI_STATUS (status);

}