1 /*******************************************************************************
3 * Module Name: utownerid - Support for Table/Method Owner IDs
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2016, Intel Corp.
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20 * including a substantially similar Disclaimer requirement for further
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23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
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27 * GNU General Public License ("GPL") version 2 as published by the Free
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49 #define _COMPONENT ACPI_UTILITIES
50 ACPI_MODULE_NAME ("utownerid")
53 /*******************************************************************************
55 * FUNCTION: AcpiUtAllocateOwnerId
57 * PARAMETERS: OwnerId - Where the new owner ID is returned
61 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to
62 * track objects created by the table or method, to be deleted
63 * when the method exits or the table is unloaded.
65 ******************************************************************************/
68 AcpiUtAllocateOwnerId (
69 ACPI_OWNER_ID
*OwnerId
)
77 ACPI_FUNCTION_TRACE (UtAllocateOwnerId
);
80 /* Guard against multiple allocations of ID to the same location */
85 "Owner ID [0x%2.2X] already exists", *OwnerId
));
86 return_ACPI_STATUS (AE_ALREADY_EXISTS
);
89 /* Mutex for the global ID mask */
91 Status
= AcpiUtAcquireMutex (ACPI_MTX_CACHES
);
92 if (ACPI_FAILURE (Status
))
94 return_ACPI_STATUS (Status
);
98 * Find a free owner ID, cycle through all possible IDs on repeated
99 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index
100 * may have to be scanned twice.
102 for (i
= 0, j
= AcpiGbl_LastOwnerIdIndex
;
103 i
< (ACPI_NUM_OWNERID_MASKS
+ 1);
106 if (j
>= ACPI_NUM_OWNERID_MASKS
)
108 j
= 0; /* Wraparound to start of mask array */
111 for (k
= AcpiGbl_NextOwnerIdOffset
; k
< 32; k
++)
113 if (AcpiGbl_OwnerIdMask
[j
] == ACPI_UINT32_MAX
)
115 /* There are no free IDs in this mask */
120 if (!(AcpiGbl_OwnerIdMask
[j
] & (1 << k
)))
123 * Found a free ID. The actual ID is the bit index plus one,
124 * making zero an invalid Owner ID. Save this as the last ID
125 * allocated and update the global ID mask.
127 AcpiGbl_OwnerIdMask
[j
] |= (1 << k
);
129 AcpiGbl_LastOwnerIdIndex
= (UINT8
) j
;
130 AcpiGbl_NextOwnerIdOffset
= (UINT8
) (k
+ 1);
133 * Construct encoded ID from the index and bit position
135 * Note: Last [j].k (bit 255) is never used and is marked
136 * permanently allocated (prevents +1 overflow)
138 *OwnerId
= (ACPI_OWNER_ID
) ((k
+ 1) + ACPI_MUL_32 (j
));
140 ACPI_DEBUG_PRINT ((ACPI_DB_VALUES
,
141 "Allocated OwnerId: %2.2X\n", (unsigned int) *OwnerId
));
146 AcpiGbl_NextOwnerIdOffset
= 0;
150 * All OwnerIds have been allocated. This typically should
151 * not happen since the IDs are reused after deallocation. The IDs are
152 * allocated upon table load (one per table) and method execution, and
153 * they are released when a table is unloaded or a method completes
156 * If this error happens, there may be very deep nesting of invoked
157 * control methods, or there may be a bug where the IDs are not released.
159 Status
= AE_OWNER_ID_LIMIT
;
160 ACPI_ERROR ((AE_INFO
,
161 "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT"));
164 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES
);
165 return_ACPI_STATUS (Status
);
169 /*******************************************************************************
171 * FUNCTION: AcpiUtReleaseOwnerId
173 * PARAMETERS: OwnerIdPtr - Pointer to a previously allocated OwnerID
175 * RETURN: None. No error is returned because we are either exiting a
176 * control method or unloading a table. Either way, we would
177 * ignore any error anyway.
179 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255
181 ******************************************************************************/
184 AcpiUtReleaseOwnerId (
185 ACPI_OWNER_ID
*OwnerIdPtr
)
187 ACPI_OWNER_ID OwnerId
= *OwnerIdPtr
;
193 ACPI_FUNCTION_TRACE_U32 (UtReleaseOwnerId
, OwnerId
);
196 /* Always clear the input OwnerId (zero is an invalid ID) */
200 /* Zero is not a valid OwnerID */
204 ACPI_ERROR ((AE_INFO
, "Invalid OwnerId: 0x%2.2X", OwnerId
));
208 /* Mutex for the global ID mask */
210 Status
= AcpiUtAcquireMutex (ACPI_MTX_CACHES
);
211 if (ACPI_FAILURE (Status
))
216 /* Normalize the ID to zero */
220 /* Decode ID to index/offset pair */
222 Index
= ACPI_DIV_32 (OwnerId
);
223 Bit
= 1 << ACPI_MOD_32 (OwnerId
);
225 /* Free the owner ID only if it is valid */
227 if (AcpiGbl_OwnerIdMask
[Index
] & Bit
)
229 AcpiGbl_OwnerIdMask
[Index
] ^= Bit
;
233 ACPI_ERROR ((AE_INFO
,
234 "Release of non-allocated OwnerId: 0x%2.2X", OwnerId
+ 1));
237 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES
);