[PATCH] fix semaphore handling in __unregister_chrdev_region

[linux/fpc-iii.git] / drivers / acpi / utilities / utdelete.c

/*******************************************************************************
 *
 * Module Name: utdelete - object deletion and reference count utilities
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2005, 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/acinterp.h>
#include <acpi/acnamesp.h>
#include <acpi/acevents.h>
#include <acpi/amlcode.h>

#define _COMPONENT          ACPI_UTILITIES
         ACPI_MODULE_NAME    ("utdelete")


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_obj
 *
 * PARAMETERS:  *Object        - Pointer to the list to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Low level object deletion, after reference counts have been
 *              updated (All reference counts, including sub-objects!)
 *
 ******************************************************************************/

void
acpi_ut_delete_internal_obj (
        union acpi_operand_object       *object)
{
        void                            *obj_pointer = NULL;
        union acpi_operand_object       *handler_desc;
        union acpi_operand_object       *second_desc;
        union acpi_operand_object       *next_desc;


        ACPI_FUNCTION_TRACE_PTR ("ut_delete_internal_obj", object);


        if (!object) {
                return_VOID;
        }

        /*
         * Must delete or free any pointers within the object that are not
         * actual ACPI objects (for example, a raw buffer pointer).
         */
        switch (ACPI_GET_OBJECT_TYPE (object)) {
        case ACPI_TYPE_STRING:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "**** String %p, ptr %p\n",
                        object, object->string.pointer));

                /* Free the actual string buffer */

                if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
                        /* But only if it is NOT a pointer into an ACPI table */

                        obj_pointer = object->string.pointer;
                }
                break;


        case ACPI_TYPE_BUFFER:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "**** Buffer %p, ptr %p\n",
                        object, object->buffer.pointer));

                /* Free the actual buffer */

                if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
                        /* But only if it is NOT a pointer into an ACPI table */

                        obj_pointer = object->buffer.pointer;
                }
                break;


        case ACPI_TYPE_PACKAGE:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, " **** Package of count %X\n",
                        object->package.count));

                /*
                 * Elements of the package are not handled here, they are deleted
                 * separately
                 */

                /* Free the (variable length) element pointer array */

                obj_pointer = object->package.elements;
                break;


        case ACPI_TYPE_DEVICE:

                if (object->device.gpe_block) {
                        (void) acpi_ev_delete_gpe_block (object->device.gpe_block);
                }

                /* Walk the handler list for this device */

                handler_desc = object->device.handler;
                while (handler_desc) {
                        next_desc = handler_desc->address_space.next;
                        acpi_ut_remove_reference (handler_desc);
                        handler_desc = next_desc;
                }
                break;


        case ACPI_TYPE_MUTEX:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "***** Mutex %p, Semaphore %p\n",
                        object, object->mutex.semaphore));

                acpi_ex_unlink_mutex (object);
                (void) acpi_os_delete_semaphore (object->mutex.semaphore);
                break;


        case ACPI_TYPE_EVENT:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "***** Event %p, Semaphore %p\n",
                        object, object->event.semaphore));

                (void) acpi_os_delete_semaphore (object->event.semaphore);
                object->event.semaphore = NULL;
                break;


        case ACPI_TYPE_METHOD:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "***** Method %p\n", object));

                /* Delete the method semaphore if it exists */

                if (object->method.semaphore) {
                        (void) acpi_os_delete_semaphore (object->method.semaphore);
                        object->method.semaphore = NULL;
                }
                break;


        case ACPI_TYPE_REGION:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "***** Region %p\n", object));

                second_desc = acpi_ns_get_secondary_object (object);
                if (second_desc) {
                        /*
                         * Free the region_context if and only if the handler is one of the
                         * default handlers -- and therefore, we created the context object
                         * locally, it was not created by an external caller.
                         */
                        handler_desc = object->region.handler;
                        if (handler_desc) {
                                if (handler_desc->address_space.hflags & ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
                                        obj_pointer = second_desc->extra.region_context;
                                }

                                acpi_ut_remove_reference (handler_desc);
                        }

                        /* Now we can free the Extra object */

                        acpi_ut_delete_object_desc (second_desc);
                }
                break;


        case ACPI_TYPE_BUFFER_FIELD:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "***** Buffer Field %p\n", object));

                second_desc = acpi_ns_get_secondary_object (object);
                if (second_desc) {
                        acpi_ut_delete_object_desc (second_desc);
                }
                break;


        default:
                break;
        }

        /* Free any allocated memory (pointer within the object) found above */

        if (obj_pointer) {
                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Deleting Object Subptr %p\n",
                                obj_pointer));
                ACPI_MEM_FREE (obj_pointer);
        }

        /* Now the object can be safely deleted */

        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
                        object, acpi_ut_get_object_type_name (object)));

        acpi_ut_delete_object_desc (object);
        return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_object_list
 *
 * PARAMETERS:  *obj_list       - Pointer to the list to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: This function deletes an internal object list, including both
 *              simple objects and package objects
 *
 ******************************************************************************/

void
acpi_ut_delete_internal_object_list (
        union acpi_operand_object       **obj_list)
{
        union acpi_operand_object       **internal_obj;


        ACPI_FUNCTION_TRACE ("ut_delete_internal_object_list");


        /* Walk the null-terminated internal list */

        for (internal_obj = obj_list; *internal_obj; internal_obj++) {
                acpi_ut_remove_reference (*internal_obj);
        }

        /* Free the combined parameter pointer list and object array */

        ACPI_MEM_FREE (obj_list);
        return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_ref_count
 *
 * PARAMETERS:  *Object         - Object whose ref count is to be updated
 *              Action          - What to do
 *
 * RETURN:      New ref count
 *
 * DESCRIPTION: Modify the ref count and return it.
 *
 ******************************************************************************/

static void
acpi_ut_update_ref_count (
        union acpi_operand_object       *object,
        u32                             action)
{
        u16                             count;
        u16                             new_count;


        ACPI_FUNCTION_NAME ("ut_update_ref_count");


        if (!object) {
                return;
        }

        count = object->common.reference_count;
        new_count = count;

        /*
         * Perform the reference count action (increment, decrement, or force delete)
         */
        switch (action) {

        case REF_INCREMENT:

                new_count++;
                object->common.reference_count = new_count;

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Obj %p Refs=%X, [Incremented]\n",
                        object, new_count));
                break;


        case REF_DECREMENT:

                if (count < 1) {
                        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
                                object, new_count));

                        new_count = 0;
                }
                else {
                        new_count--;

                        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Obj %p Refs=%X, [Decremented]\n",
                                object, new_count));
                }

                if (ACPI_GET_OBJECT_TYPE (object) == ACPI_TYPE_METHOD) {
                        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Method Obj %p Refs=%X, [Decremented]\n",
                                object, new_count));
                }

                object->common.reference_count = new_count;
                if (new_count == 0) {
                        acpi_ut_delete_internal_obj (object);
                }

                break;


        case REF_FORCE_DELETE:

                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Obj %p Refs=%X, Force delete! (Set to 0)\n",
                        object, count));

                new_count = 0;
                object->common.reference_count = new_count;
                acpi_ut_delete_internal_obj (object);
                break;


        default:

                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unknown action (%X)\n", action));
                break;
        }

        /*
         * Sanity check the reference count, for debug purposes only.
         * (A deleted object will have a huge reference count)
         */
        if (count > ACPI_MAX_REFERENCE_COUNT) {

                ACPI_DEBUG_PRINT ((ACPI_DB_WARN,
                        "**** Warning **** Large Reference Count (%X) in object %p\n\n",
                        count, object));
        }

        return;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_object_reference
 *
 * PARAMETERS:  *Object             - Increment ref count for this object
 *                                    and all sub-objects
 *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 *                                    REF_FORCE_DELETE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Increment the object reference count
 *
 * Object references are incremented when:
 * 1) An object is attached to a Node (namespace object)
 * 2) An object is copied (all subobjects must be incremented)
 *
 * Object references are decremented when:
 * 1) An object is detached from an Node
 *
 ******************************************************************************/

acpi_status
acpi_ut_update_object_reference (
        union acpi_operand_object       *object,
        u16                             action)
{
        acpi_status                     status;
        u32                             i;
        union acpi_generic_state         *state_list = NULL;
        union acpi_generic_state         *state;
        union acpi_operand_object        *tmp;

        ACPI_FUNCTION_TRACE_PTR ("ut_update_object_reference", object);


        /* Ignore a null object ptr */

        if (!object) {
                return_ACPI_STATUS (AE_OK);
        }

        /* Make sure that this isn't a namespace handle */

        if (ACPI_GET_DESCRIPTOR_TYPE (object) == ACPI_DESC_TYPE_NAMED) {
                ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Object %p is NS handle\n", object));
                return_ACPI_STATUS (AE_OK);
        }

        state = acpi_ut_create_update_state (object, action);

        while (state) {
                object = state->update.object;
                action = state->update.value;
                acpi_ut_delete_generic_state (state);

                /*
                 * All sub-objects must have their reference count incremented also.
                 * Different object types have different subobjects.
                 */
                switch (ACPI_GET_OBJECT_TYPE (object)) {
                case ACPI_TYPE_DEVICE:

                        tmp = object->device.system_notify;
                        if (tmp && (tmp->common.reference_count <= 1) && action == REF_DECREMENT)
                                object->device.system_notify = NULL;
                        acpi_ut_update_ref_count (tmp, action);

                        tmp = object->device.device_notify;
                        if (tmp && (tmp->common.reference_count <= 1) && action == REF_DECREMENT)
                                object->device.device_notify = NULL;
                        acpi_ut_update_ref_count (tmp, action);

                        break;


                case ACPI_TYPE_PACKAGE:

                        /*
                         * We must update all the sub-objects of the package
                         * (Each of whom may have their own sub-objects, etc.
                         */
                        for (i = 0; i < object->package.count; i++) {
                                /*
                                 * Push each element onto the stack for later processing.
                                 * Note: There can be null elements within the package,
                                 * these are simply ignored
                                 */
                                status = acpi_ut_create_update_state_and_push (
                                                 object->package.elements[i], action, &state_list);
                                if (ACPI_FAILURE (status)) {
                                        goto error_exit;
                                }

                                tmp = object->package.elements[i];
                                if (tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                        object->package.elements[i] = NULL;
                        }
                        break;


                case ACPI_TYPE_BUFFER_FIELD:

                        status = acpi_ut_create_update_state_and_push (
                                         object->buffer_field.buffer_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->buffer_field.buffer_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->buffer_field.buffer_obj = NULL;
                        break;


                case ACPI_TYPE_LOCAL_REGION_FIELD:

                        status = acpi_ut_create_update_state_and_push (
                                         object->field.region_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->field.region_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->field.region_obj = NULL;
                   break;


                case ACPI_TYPE_LOCAL_BANK_FIELD:

                        status = acpi_ut_create_update_state_and_push (
                                         object->bank_field.bank_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->bank_field.bank_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->bank_field.bank_obj = NULL;

                        status = acpi_ut_create_update_state_and_push (
                                         object->bank_field.region_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->bank_field.region_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->bank_field.region_obj = NULL;
                        break;


                case ACPI_TYPE_LOCAL_INDEX_FIELD:

                        status = acpi_ut_create_update_state_and_push (
                                         object->index_field.index_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->index_field.index_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->index_field.index_obj = NULL;

                        status = acpi_ut_create_update_state_and_push (
                                         object->index_field.data_obj, action, &state_list);
                        if (ACPI_FAILURE (status)) {
                                goto error_exit;
                        }

                        tmp = object->index_field.data_obj;
                        if ( tmp && (tmp->common.reference_count <= 1)  && action == REF_DECREMENT)
                                object->index_field.data_obj = NULL;
                        break;


                case ACPI_TYPE_LOCAL_REFERENCE:

                        /*
                         * The target of an Index (a package, string, or buffer) must track
                         * changes to the ref count of the index.
                         */
                        if (object->reference.opcode == AML_INDEX_OP) {
                                status = acpi_ut_create_update_state_and_push (
                                                 object->reference.object, action, &state_list);
                                if (ACPI_FAILURE (status)) {
                                        goto error_exit;
                                }
                        }
                        break;


                case ACPI_TYPE_REGION:
                default:

                        /* No subobjects */
                        break;
                }

                /*
                 * Now we can update the count in the main object.  This can only
                 * happen after we update the sub-objects in case this causes the
                 * main object to be deleted.
                 */
                acpi_ut_update_ref_count (object, action);

                /* Move on to the next object to be updated */

                state = acpi_ut_pop_generic_state (&state_list);
        }

        return_ACPI_STATUS (AE_OK);


error_exit:

        ACPI_REPORT_ERROR (("Could not update object reference count, %s\n",
                acpi_format_exception (status)));

        return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_add_reference
 *
 * PARAMETERS:  *Object        - Object whose reference count is to be
 *                                  incremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add one reference to an ACPI object
 *
 ******************************************************************************/

void
acpi_ut_add_reference (
        union acpi_operand_object       *object)
{

        ACPI_FUNCTION_TRACE_PTR ("ut_add_reference", object);


        /* Ensure that we have a valid object */

        if (!acpi_ut_valid_internal_object (object)) {
                return_VOID;
        }

        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
                "Obj %p Current Refs=%X [To Be Incremented]\n",
                object, object->common.reference_count));

        /* Increment the reference count */

        (void) acpi_ut_update_object_reference (object, REF_INCREMENT);
        return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_remove_reference
 *
 * PARAMETERS:  *Object        - Object whose ref count will be decremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Decrement the reference count of an ACPI internal object
 *
 ******************************************************************************/

void
acpi_ut_remove_reference (
        union acpi_operand_object       *object)
{

        ACPI_FUNCTION_TRACE_PTR ("ut_remove_reference", object);


        /*
         * Allow a NULL pointer to be passed in, just ignore it.  This saves
         * each caller from having to check.  Also, ignore NS nodes.
         *
         */
        if (!object ||
                (ACPI_GET_DESCRIPTOR_TYPE (object) == ACPI_DESC_TYPE_NAMED)) {
                return_VOID;
        }

        /* Ensure that we have a valid object */

        if (!acpi_ut_valid_internal_object (object)) {
                return_VOID;
        }

        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
                "Obj %p Current Refs=%X [To Be Decremented]\n",
                object, object->common.reference_count));

        /*
         * Decrement the reference count, and only actually delete the object
         * if the reference count becomes 0.  (Must also decrement the ref count
         * of all subobjects!)
         */
        (void) acpi_ut_update_object_reference (object, REF_DECREMENT);
        return_VOID;
}