/******************************************************************************* * * Module Name: utownerid - Support for Table/Method Owner IDs * ******************************************************************************/ /* * Copyright (C) 2000 - 2014, 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 <acpi/acpi.h> #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; }