// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
 *
 * Module Name: nseval - Object evaluation, includes control method execution
 *
 ******************************************************************************/

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

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nseval")

/* Local prototypes */
static void
acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
                         struct acpi_evaluate_info *info);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_evaluate
 *
 * PARAMETERS:  info            - Evaluation info block, contains these fields
 *                                and more:
 *                  prefix_node     - Prefix or Method/Object Node to execute
 *                  relative_path   - Name of method to execute, If NULL, the
 *                                    Node is the object to execute
 *                  parameters      - List of parameters to pass to the method,
 *                                    terminated by NULL. Params itself may be
 *                                    NULL if no parameters are being passed.
 *                  parameter_type  - Type of Parameter list
 *                  return_object   - Where to put method's return value (if
 *                                    any). If NULL, no value is returned.
 *                  flags           - ACPI_IGNORE_RETURN_VALUE to delete return
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute a control method or return the current value of an
 *              ACPI namespace object.
 *
 * MUTEX:       Locks interpreter
 *
 ******************************************************************************/

acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_evaluate);

        if (!info) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        if (!info->node) {
                /*
                 * Get the actual namespace node for the target object if we
                 * need to. Handles these cases:
                 *
                 * 1) Null node, valid pathname from root (absolute path)
                 * 2) Node and valid pathname (path relative to Node)
                 * 3) Node, Null pathname
                 */
                status =
                    acpi_ns_get_node(info->prefix_node, info->relative_pathname,
                                     ACPI_NS_NO_UPSEARCH, &info->node);
                if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                }
        }

        /*
         * For a method alias, we must grab the actual method node so that
         * proper scoping context will be established before execution.
         */
        if (acpi_ns_get_type(info->node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
                info->node =
                    ACPI_CAST_PTR(struct acpi_namespace_node,
                                  info->node->object);
        }

        /* Complete the info block initialization */

        info->return_object = NULL;
        info->node_flags = info->node->flags;
        info->obj_desc = acpi_ns_get_attached_object(info->node);

        ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "%s [%p] Value %p\n",
                          info->relative_pathname, info->node,
                          acpi_ns_get_attached_object(info->node)));

        /* Get info if we have a predefined name (_HID, etc.) */

        info->predefined =
            acpi_ut_match_predefined_method(info->node->name.ascii);

        /* Get the full pathname to the object, for use in warning messages */

        info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
        if (!info->full_pathname) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Count the number of arguments being passed in */

        info->param_count = 0;
        if (info->parameters) {
                while (info->parameters[info->param_count]) {
                        info->param_count++;
                }

                /* Warn on impossible argument count */

                if (info->param_count > ACPI_METHOD_NUM_ARGS) {
                        ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
                                              ACPI_WARN_ALWAYS,
                                              "Excess arguments (%u) - using only %u",
                                              info->param_count,
                                              ACPI_METHOD_NUM_ARGS));

                        info->param_count = ACPI_METHOD_NUM_ARGS;
                }
        }

        /*
         * For predefined names: Check that the declared argument count
         * matches the ACPI spec -- otherwise this is a BIOS error.
         */
        acpi_ns_check_acpi_compliance(info->full_pathname, info->node,
                                      info->predefined);

        /*
         * For all names: Check that the incoming argument count for
         * this method/object matches the actual ASL/AML definition.
         */
        acpi_ns_check_argument_count(info->full_pathname, info->node,
                                     info->param_count, info->predefined);

        /* For predefined names: Typecheck all incoming arguments */

        acpi_ns_check_argument_types(info);

        /*
         * Three major evaluation cases:
         *
         * 1) Object types that cannot be evaluated by definition
         * 2) The object is a control method -- execute it
         * 3) The object is not a method -- just return it's current value
         */
        switch (acpi_ns_get_type(info->node)) {
        case ACPI_TYPE_ANY:
        case ACPI_TYPE_DEVICE:
        case ACPI_TYPE_EVENT:
        case ACPI_TYPE_MUTEX:
        case ACPI_TYPE_REGION:
        case ACPI_TYPE_THERMAL:
        case ACPI_TYPE_LOCAL_SCOPE:
                /*
                 * 1) Disallow evaluation of these object types. For these,
                 *    object evaluation is undefined.
                 */
                ACPI_ERROR((AE_INFO,
                            "%s: This object type [%s] "
                            "never contains data and cannot be evaluated",
                            info->full_pathname,
                            acpi_ut_get_type_name(info->node->type)));

                status = AE_TYPE;
                goto cleanup;

        case ACPI_TYPE_METHOD:
                /*
                 * 2) Object is a control method - execute it
                 */

                /* Verify that there is a method object associated with this node */

                if (!info->obj_desc) {
                        ACPI_ERROR((AE_INFO,
                                    "%s: Method has no attached sub-object",
                                    info->full_pathname));
                        status = AE_NULL_OBJECT;
                        goto cleanup;
                }

                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "**** Execute method [%s] at AML address %p length %X\n",
                                  info->full_pathname,
                                  info->obj_desc->method.aml_start + 1,
                                  info->obj_desc->method.aml_length - 1));

                /*
                 * Any namespace deletion must acquire both the namespace and
                 * interpreter locks to ensure that no thread is using the portion of
                 * the namespace that is being deleted.
                 *
                 * Execute the method via the interpreter. The interpreter is locked
                 * here before calling into the AML parser
                 */
                acpi_ex_enter_interpreter();
                status = acpi_ps_execute_method(info);
                acpi_ex_exit_interpreter();
                break;

        default:
                /*
                 * 3) All other non-method objects -- get the current object value
                 */

                /*
                 * Some objects require additional resolution steps (e.g., the Node
                 * may be a field that must be read, etc.) -- we can't just grab
                 * the object out of the node.
                 *
                 * Use resolve_node_to_value() to get the associated value.
                 *
                 * NOTE: we can get away with passing in NULL for a walk state because
                 * the Node is guaranteed to not be a reference to either a method
                 * local or a method argument (because this interface is never called
                 * from a running method.)
                 *
                 * Even though we do not directly invoke the interpreter for object
                 * resolution, we must lock it because we could access an op_region.
                 * The op_region access code assumes that the interpreter is locked.
                 */
                acpi_ex_enter_interpreter();

                /* TBD: resolve_node_to_value has a strange interface, fix */

                info->return_object =
                    ACPI_CAST_PTR(union acpi_operand_object, info->node);

                status =
                    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
                                                  (struct acpi_namespace_node,
                                                   &info->return_object), NULL);
                acpi_ex_exit_interpreter();

                if (ACPI_FAILURE(status)) {
                        info->return_object = NULL;
                        goto cleanup;
                }

                ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Returned object %p [%s]\n",
                                  info->return_object,
                                  acpi_ut_get_object_type_name(info->
                                                               return_object)));

                status = AE_CTRL_RETURN_VALUE;  /* Always has a "return value" */
                break;
        }

        /*
         * For predefined names, check the return value against the ACPI
         * specification. Some incorrect return value types are repaired.
         */
        (void)acpi_ns_check_return_value(info->node, info, info->param_count,
                                         status, &info->return_object);

        /* Check if there is a return value that must be dealt with */

        if (status == AE_CTRL_RETURN_VALUE) {

                /* If caller does not want the return value, delete it */

                if (info->flags & ACPI_IGNORE_RETURN_VALUE) {
                        acpi_ut_remove_reference(info->return_object);
                        info->return_object = NULL;
                }

                /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */

                status = AE_OK;
        } else if (ACPI_FAILURE(status)) {

                /* If return_object exists, delete it */

                if (info->return_object) {
                        acpi_ut_remove_reference(info->return_object);
                        info->return_object = NULL;
                }
        }

        ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                          "*** Completed evaluation of object %s ***\n",
                          info->relative_pathname));

cleanup:
        /*
         * Namespace was unlocked by the handling acpi_ns* function, so we
         * just free the pathname and return
         */
        ACPI_FREE(info->full_pathname);
        info->full_pathname = NULL;
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_exec_module_code_list
 *
 * PARAMETERS:  None
 *
 * RETURN:      None. Exceptions during method execution are ignored, since
 *              we cannot abort a table load.
 *
 * DESCRIPTION: Execute all elements of the global module-level code list.
 *              Each element is executed as a single control method.
 *
 * NOTE: With this option enabled, each block of detected executable AML
 * code that is outside of any control method is wrapped with a temporary
 * control method object and placed on a global list. The methods on this
 * list are executed below.
 *
 * This function executes the module-level code for all tables only after
 * all of the tables have been loaded. It is a legacy option and is
 * not compatible with other ACPI implementations. See acpi_ns_load_table.
 *
 * This function will be removed when the legacy option is removed.
 *
 ******************************************************************************/

void acpi_ns_exec_module_code_list(void)
{
        union acpi_operand_object *prev;
        union acpi_operand_object *next;
        struct acpi_evaluate_info *info;
        u32 method_count = 0;

        ACPI_FUNCTION_TRACE(ns_exec_module_code_list);

        /* Exit now if the list is empty */

        next = acpi_gbl_module_code_list;
        if (!next) {
                ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
                                  "Legacy MLC block list is empty\n"));

                return_VOID;
        }

        /* Allocate the evaluation information block */

        info = ACPI_ALLOCATE(sizeof(struct acpi_evaluate_info));
        if (!info) {
                return_VOID;
        }

        /* Walk the list, executing each "method" */

        while (next) {
                prev = next;
                next = next->method.mutex;

                /* Clear the link field and execute the method */

                prev->method.mutex = NULL;
                acpi_ns_exec_module_code(prev, info);
                method_count++;

                /* Delete the (temporary) method object */

                acpi_ut_remove_reference(prev);
        }

        ACPI_INFO(("Executed %u blocks of module-level executable AML code",
                   method_count));

        ACPI_FREE(info);
        acpi_gbl_module_code_list = NULL;
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_exec_module_code
 *
 * PARAMETERS:  method_obj          - Object container for the module-level code
 *              info                - Info block for method evaluation
 *
 * RETURN:      None. Exceptions during method execution are ignored, since
 *              we cannot abort a table load.
 *
 * DESCRIPTION: Execute a control method containing a block of module-level
 *              executable AML code. The control method is temporarily
 *              installed to the root node, then evaluated.
 *
 ******************************************************************************/

static void
acpi_ns_exec_module_code(union acpi_operand_object *method_obj,
                         struct acpi_evaluate_info *info)
{
        union acpi_operand_object *parent_obj;
        struct acpi_namespace_node *parent_node;
        acpi_object_type type;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_exec_module_code);

        /*
         * Get the parent node. We cheat by using the next_object field
         * of the method object descriptor.
         */
        parent_node =
            ACPI_CAST_PTR(struct acpi_namespace_node,
                                    method_obj->method.next_object);
        type = acpi_ns_get_type(parent_node);

        /*
         * Get the region handler and save it in the method object. We may need
         * this if an operation region declaration causes a _REG method to be run.
         *
         * We can't do this in acpi_ps_link_module_code because
         * acpi_gbl_root_node->Object is NULL at PASS1.
         */
        if ((type == ACPI_TYPE_DEVICE) && parent_node->object) {
                method_obj->method.dispatch.handler =
                    parent_node->object->device.handler;
        }

        /* Must clear next_object (acpi_ns_attach_object needs the field) */

        method_obj->method.next_object = NULL;

        /* Initialize the evaluation information block */

        memset(info, 0, sizeof(struct acpi_evaluate_info));
        info->prefix_node = parent_node;

        /*
         * Get the currently attached parent object. Add a reference,
         * because the ref count will be decreased when the method object
         * is installed to the parent node.
         */
        parent_obj = acpi_ns_get_attached_object(parent_node);
        if (parent_obj) {
                acpi_ut_add_reference(parent_obj);
        }

        /* Install the method (module-level code) in the parent node */

        status =
            acpi_ns_attach_object(parent_node, method_obj, ACPI_TYPE_METHOD);
        if (ACPI_FAILURE(status)) {
                goto exit;
        }

        /* Execute the parent node as a control method */

        status = acpi_ns_evaluate(info);

        ACPI_DEBUG_PRINT((ACPI_DB_INIT_NAMES,
                          "Executed module-level code at %p\n",
                          method_obj->method.aml_start));

        /* Delete a possible implicit return value (in slack mode) */

        if (info->return_object) {
                acpi_ut_remove_reference(info->return_object);
        }

        /* Detach the temporary method object */

        acpi_ns_detach_object(parent_node);

        /* Restore the original parent object */

        if (parent_obj) {
                status = acpi_ns_attach_object(parent_node, parent_obj, type);
        } else {
                parent_node->type = (u8)type;
        }

exit:
        if (parent_obj) {
                acpi_ut_remove_reference(parent_obj);
        }
        return_VOID;
}