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

 *

 * Module Name: utownerid - Support for Table/Method Owner IDs

 *

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

/*

 * Copyright (C) 2000 - 2015, 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 

#include "accommon.h"

#include "acnamesp.h"

#define _COMPONENT          ACPI_UTILITIES

ACPI_MODULE_NAME("utownerid")

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

 *

 * FUNCTION:    acpi_ut_allocate_owner_id

 *

 * PARAMETERS:  owner_id        - Where the new owner ID is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to

 *              track objects created by the table or method, to be deleted

 *              when the method exits or the table is unloaded.

 *

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

acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)

{

	u32 i;

	u32 j;

	u32 k;

	acpi_status status;

	ACPI_FUNCTION_TRACE(ut_allocate_owner_id);

	/* Guard against multiple allocations of ID to the same location */

	if (*owner_id) {

		ACPI_ERROR((AE_INFO, "Owner ID [0x%2.2X] already exists",

			    *owner_id));

		return_ACPI_STATUS(AE_ALREADY_EXISTS);

	}

	/* Mutex for the global ID mask */

	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);

	if (ACPI_FAILURE(status)) {

		return_ACPI_STATUS(status);

	}

	/*

	 * Find a free owner ID, cycle through all possible IDs on repeated

	 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have

	 * to be scanned twice.

	 */

	for (i = 0, j = acpi_gbl_last_owner_id_index;

	     i < (ACPI_NUM_OWNERID_MASKS + 1); i++, j++) {

		if (j >= ACPI_NUM_OWNERID_MASKS) {

			j = 0;	/* Wraparound to start of mask array */

		}

		for (k = acpi_gbl_next_owner_id_offset; k < 32; k++) {

			if (acpi_gbl_owner_id_mask[j] == ACPI_UINT32_MAX) {

				/* There are no free IDs in this mask */

				break;

			}

			if (!(acpi_gbl_owner_id_mask[j] & (1 << k))) {

				/*

				 * Found a free ID. The actual ID is the bit index plus one,

				 * making zero an invalid Owner ID. Save this as the last ID

				 * allocated and update the global ID mask.

				 */

				acpi_gbl_owner_id_mask[j] |= (1 << k);

				acpi_gbl_last_owner_id_index = (u8)j;

				acpi_gbl_next_owner_id_offset = (u8)(k + 1);

				/*

				 * Construct encoded ID from the index and bit position

				 *

				 * Note: Last [j].k (bit 255) is never used and is marked

				 * permanently allocated (prevents +1 overflow)

				 */

				*owner_id =

				    (acpi_owner_id) ((k + 1) + ACPI_MUL_32(j));

				ACPI_DEBUG_PRINT((ACPI_DB_VALUES,

						  "Allocated OwnerId: %2.2X\n",

						  (unsigned int)*owner_id));

				goto exit;

			}

		}

		acpi_gbl_next_owner_id_offset = 0;

	}

	/*

	 * All owner_ids have been allocated. This typically should

	 * not happen since the IDs are reused after deallocation. The IDs are

	 * allocated upon table load (one per table) and method execution, and

	 * they are released when a table is unloaded or a method completes

	 * execution.

	 *

	 * If this error happens, there may be very deep nesting of invoked control

	 * methods, or there may be a bug where the IDs are not released.

	 */

	status = AE_OWNER_ID_LIMIT;

	ACPI_ERROR((AE_INFO,

		    "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT"));

exit:

	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);

	return_ACPI_STATUS(status);

}

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

 *

 * FUNCTION:    acpi_ut_release_owner_id

 *

 * PARAMETERS:  owner_id_ptr        - Pointer to a previously allocated owner_ID

 *

 * RETURN:      None. No error is returned because we are either exiting a

 *              control method or unloading a table. Either way, we would

 *              ignore any error anyway.

 *

 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255

 *

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

void acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr)

{

	acpi_owner_id owner_id = *owner_id_ptr;

	acpi_status status;

	u32 index;

	u32 bit;

	ACPI_FUNCTION_TRACE_U32(ut_release_owner_id, owner_id);

	/* Always clear the input owner_id (zero is an invalid ID) */

	*owner_id_ptr = 0;

	/* Zero is not a valid owner_ID */

	if (owner_id == 0) {

		ACPI_ERROR((AE_INFO, "Invalid OwnerId: 0x%2.2X", owner_id));

		return_VOID;

	}

	/* Mutex for the global ID mask */

	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);

	if (ACPI_FAILURE(status)) {

		return_VOID;

	}

	/* Normalize the ID to zero */

	owner_id--;

	/* Decode ID to index/offset pair */

	index = ACPI_DIV_32(owner_id);

	bit = 1 << ACPI_MOD_32(owner_id);

	/* Free the owner ID only if it is valid */

	if (acpi_gbl_owner_id_mask[index] & bit) {

		acpi_gbl_owner_id_mask[index] ^= bit;

	} else {

		ACPI_ERROR((AE_INFO,

			    "Release of non-allocated OwnerId: 0x%2.2X",

			    owner_id + 1));

	}

	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);

	return_VOID;

}