1 /*******************************************************************************
2 *
3 * Module Name: utownerid - Support for Table/Method Owner IDs
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2014, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44
45 #define __UTOWNERID_C__
46
47 #include "acpi.h"
48 #include "accommon.h"
49 #include "acnamesp.h"
50
51
52 #define _COMPONENT ACPI_UTILITIES
53 ACPI_MODULE_NAME ("utownerid")
54
55
56 /*******************************************************************************
57 *
58 * FUNCTION: AcpiUtAllocateOwnerId
59 *
60 * PARAMETERS: OwnerId - Where the new owner ID is returned
61 *
62 * RETURN: Status
63 *
64 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to
65 * track objects created by the table or method, to be deleted
66 * when the method exits or the table is unloaded.
67 *
68 ******************************************************************************/
69
70 ACPI_STATUS
71 AcpiUtAllocateOwnerId (
72 ACPI_OWNER_ID *OwnerId)
73 {
74 UINT32 i;
75 UINT32 j;
76 UINT32 k;
77 ACPI_STATUS Status;
78
79
80 ACPI_FUNCTION_TRACE (UtAllocateOwnerId);
81
82
83 /* Guard against multiple allocations of ID to the same location */
84
85 if (*OwnerId)
86 {
87 ACPI_ERROR ((AE_INFO, "Owner ID [0x%2.2X] already exists", *OwnerId));
88 return_ACPI_STATUS (AE_ALREADY_EXISTS);
89 }
90
91 /* Mutex for the global ID mask */
92
93 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES);
94 if (ACPI_FAILURE (Status))
95 {
96 return_ACPI_STATUS (Status);
97 }
98
99 /*
100 * Find a free owner ID, cycle through all possible IDs on repeated
101 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have
102 * to be scanned twice.
103 */
104 for (i = 0, j = AcpiGbl_LastOwnerIdIndex;
105 i < (ACPI_NUM_OWNERID_MASKS + 1);
106 i++, j++)
107 {
108 if (j >= ACPI_NUM_OWNERID_MASKS)
109 {
110 j = 0; /* Wraparound to start of mask array */
111 }
112
113 for (k = AcpiGbl_NextOwnerIdOffset; k < 32; k++)
114 {
115 if (AcpiGbl_OwnerIdMask[j] == ACPI_UINT32_MAX)
116 {
117 /* There are no free IDs in this mask */
118
119 break;
120 }
121
122 if (!(AcpiGbl_OwnerIdMask[j] & (1 << k)))
123 {
124 /*
125 * Found a free ID. The actual ID is the bit index plus one,
126 * making zero an invalid Owner ID. Save this as the last ID
127 * allocated and update the global ID mask.
128 */
129 AcpiGbl_OwnerIdMask[j] |= (1 << k);
130
131 AcpiGbl_LastOwnerIdIndex = (UINT8) j;
132 AcpiGbl_NextOwnerIdOffset = (UINT8) (k + 1);
133
134 /*
135 * Construct encoded ID from the index and bit position
136 *
137 * Note: Last [j].k (bit 255) is never used and is marked
138 * permanently allocated (prevents +1 overflow)
139 */
140 *OwnerId = (ACPI_OWNER_ID) ((k + 1) + ACPI_MUL_32 (j));
141
142 ACPI_DEBUG_PRINT ((ACPI_DB_VALUES,
143 "Allocated OwnerId: %2.2X\n", (unsigned int) *OwnerId));
144 goto Exit;
145 }
146 }
147
148 AcpiGbl_NextOwnerIdOffset = 0;
149 }
150
151 /*
152 * All OwnerIds have been allocated. This typically should
153 * not happen since the IDs are reused after deallocation. The IDs are
154 * allocated upon table load (one per table) and method execution, and
155 * they are released when a table is unloaded or a method completes
156 * execution.
157 *
158 * If this error happens, there may be very deep nesting of invoked control
159 * methods, or there may be a bug where the IDs are not released.
160 */
161 Status = AE_OWNER_ID_LIMIT;
162 ACPI_ERROR ((AE_INFO,
163 "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT"));
164
165 Exit:
166 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES);
167 return_ACPI_STATUS (Status);
168 }
169
170
171 /*******************************************************************************
172 *
173 * FUNCTION: AcpiUtReleaseOwnerId
174 *
175 * PARAMETERS: OwnerIdPtr - Pointer to a previously allocated OwnerID
176 *
177 * RETURN: None. No error is returned because we are either exiting a
178 * control method or unloading a table. Either way, we would
179 * ignore any error anyway.
180 *
181 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255
182 *
183 ******************************************************************************/
184
185 void
186 AcpiUtReleaseOwnerId (
187 ACPI_OWNER_ID *OwnerIdPtr)
188 {
189 ACPI_OWNER_ID OwnerId = *OwnerIdPtr;
190 ACPI_STATUS Status;
191 UINT32 Index;
192 UINT32 Bit;
193
194
195 ACPI_FUNCTION_TRACE_U32 (UtReleaseOwnerId, OwnerId);
196
197
198 /* Always clear the input OwnerId (zero is an invalid ID) */
199
200 *OwnerIdPtr = 0;
201
202 /* Zero is not a valid OwnerID */
203
204 if (OwnerId == 0)
205 {
206 ACPI_ERROR ((AE_INFO, "Invalid OwnerId: 0x%2.2X", OwnerId));
207 return_VOID;
208 }
209
210 /* Mutex for the global ID mask */
211
212 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES);
213 if (ACPI_FAILURE (Status))
214 {
215 return_VOID;
216 }
217
218 /* Normalize the ID to zero */
219
220 OwnerId--;
221
222 /* Decode ID to index/offset pair */
223
224 Index = ACPI_DIV_32 (OwnerId);
225 Bit = 1 << ACPI_MOD_32 (OwnerId);
226
227 /* Free the owner ID only if it is valid */
228
229 if (AcpiGbl_OwnerIdMask[Index] & Bit)
230 {
231 AcpiGbl_OwnerIdMask[Index] ^= Bit;
232 }
233 else
234 {
235 ACPI_ERROR ((AE_INFO,
236 "Release of non-allocated OwnerId: 0x%2.2X", OwnerId + 1));
237 }
238
239 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES);
240 return_VOID;
241 }