1 /*******************************************************************************
3 * Module Name: utownerid - Support for Table/Method Owner IDs
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2014, Intel Corp.
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44 #define __UTOWNERID_C__
51 #define _COMPONENT ACPI_UTILITIES
52 ACPI_MODULE_NAME ("utownerid")
55 /*******************************************************************************
57 * FUNCTION: AcpiUtAllocateOwnerId
59 * PARAMETERS: OwnerId - Where the new owner ID is returned
63 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to
64 * track objects created by the table or method, to be deleted
65 * when the method exits or the table is unloaded.
67 ******************************************************************************/
70 AcpiUtAllocateOwnerId (
71 ACPI_OWNER_ID *OwnerId)
79 ACPI_FUNCTION_TRACE (UtAllocateOwnerId);
82 /* Guard against multiple allocations of ID to the same location */
86 ACPI_ERROR ((AE_INFO, "Owner ID [0x%2.2X] already exists", *OwnerId));
87 return_ACPI_STATUS (AE_ALREADY_EXISTS);
90 /* Mutex for the global ID mask */
92 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES);
93 if (ACPI_FAILURE (Status))
95 return_ACPI_STATUS (Status);
99 * Find a free owner ID, cycle through all possible IDs on repeated
100 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have
101 * to be scanned twice.
103 for (i = 0, j = AcpiGbl_LastOwnerIdIndex;
104 i < (ACPI_NUM_OWNERID_MASKS + 1);
107 if (j >= ACPI_NUM_OWNERID_MASKS)
109 j = 0; /* Wraparound to start of mask array */
112 for (k = AcpiGbl_NextOwnerIdOffset; k < 32; k++)
114 if (AcpiGbl_OwnerIdMask[j] == ACPI_UINT32_MAX)
116 /* There are no free IDs in this mask */
121 if (!(AcpiGbl_OwnerIdMask[j] & (1 << k)))
124 * Found a free ID. The actual ID is the bit index plus one,
125 * making zero an invalid Owner ID. Save this as the last ID
126 * allocated and update the global ID mask.
128 AcpiGbl_OwnerIdMask[j] |= (1 << k);
130 AcpiGbl_LastOwnerIdIndex = (UINT8) j;
131 AcpiGbl_NextOwnerIdOffset = (UINT8) (k + 1);
134 * Construct encoded ID from the index and bit position
136 * Note: Last [j].k (bit 255) is never used and is marked
137 * permanently allocated (prevents +1 overflow)
139 *OwnerId = (ACPI_OWNER_ID) ((k + 1) + ACPI_MUL_32 (j));
141 ACPI_DEBUG_PRINT ((ACPI_DB_VALUES,
142 "Allocated OwnerId: %2.2X\n", (unsigned int) *OwnerId));
147 AcpiGbl_NextOwnerIdOffset = 0;
151 * All OwnerIds have been allocated. This typically should
152 * not happen since the IDs are reused after deallocation. The IDs are
153 * allocated upon table load (one per table) and method execution, and
154 * they are released when a table is unloaded or a method completes
157 * If this error happens, there may be very deep nesting of invoked control
158 * methods, or there may be a bug where the IDs are not released.
160 Status = AE_OWNER_ID_LIMIT;
161 ACPI_ERROR ((AE_INFO,
162 "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT"));
165 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES);
166 return_ACPI_STATUS (Status);
170 /*******************************************************************************
172 * FUNCTION: AcpiUtReleaseOwnerId
174 * PARAMETERS: OwnerIdPtr - Pointer to a previously allocated OwnerID
176 * RETURN: None. No error is returned because we are either exiting a
177 * control method or unloading a table. Either way, we would
178 * ignore any error anyway.
180 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255
182 ******************************************************************************/
185 AcpiUtReleaseOwnerId (
186 ACPI_OWNER_ID *OwnerIdPtr)
188 ACPI_OWNER_ID OwnerId = *OwnerIdPtr;
194 ACPI_FUNCTION_TRACE_U32 (UtReleaseOwnerId, OwnerId);
197 /* Always clear the input OwnerId (zero is an invalid ID) */
201 /* Zero is not a valid OwnerID */
205 ACPI_ERROR ((AE_INFO, "Invalid OwnerId: 0x%2.2X", OwnerId));
209 /* Mutex for the global ID mask */
211 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES);
212 if (ACPI_FAILURE (Status))
217 /* Normalize the ID to zero */
221 /* Decode ID to index/offset pair */
223 Index = ACPI_DIV_32 (OwnerId);
224 Bit = 1 << ACPI_MOD_32 (OwnerId);
226 /* Free the owner ID only if it is valid */
228 if (AcpiGbl_OwnerIdMask[Index] & Bit)
230 AcpiGbl_OwnerIdMask[Index] ^= Bit;
234 ACPI_ERROR ((AE_INFO,
235 "Release of non-allocated OwnerId: 0x%2.2X", OwnerId + 1));
238 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES);