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1 | /******************************************************************************* |
2 | * | |
3 | * Module Name: utownerid - Support for Table/Method Owner IDs | |
4 | * | |
5 | ******************************************************************************/ | |
6 | ||
7 | /* | |
82a80941 | 8 | * Copyright (C) 2000 - 2015, Intel Corp. |
42f8fb75 BM |
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 | #include <acpi/acpi.h> | |
45 | #include "accommon.h" | |
46 | #include "acnamesp.h" | |
47 | ||
48 | #define _COMPONENT ACPI_UTILITIES | |
49 | ACPI_MODULE_NAME("utownerid") | |
50 | ||
51 | /******************************************************************************* | |
52 | * | |
53 | * FUNCTION: acpi_ut_allocate_owner_id | |
54 | * | |
55 | * PARAMETERS: owner_id - Where the new owner ID is returned | |
56 | * | |
57 | * RETURN: Status | |
58 | * | |
59 | * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to | |
60 | * track objects created by the table or method, to be deleted | |
61 | * when the method exits or the table is unloaded. | |
62 | * | |
63 | ******************************************************************************/ | |
64 | acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id) | |
65 | { | |
66 | u32 i; | |
67 | u32 j; | |
68 | u32 k; | |
69 | acpi_status status; | |
70 | ||
71 | ACPI_FUNCTION_TRACE(ut_allocate_owner_id); | |
72 | ||
73 | /* Guard against multiple allocations of ID to the same location */ | |
74 | ||
75 | if (*owner_id) { | |
76 | ACPI_ERROR((AE_INFO, "Owner ID [0x%2.2X] already exists", | |
77 | *owner_id)); | |
78 | return_ACPI_STATUS(AE_ALREADY_EXISTS); | |
79 | } | |
80 | ||
81 | /* Mutex for the global ID mask */ | |
82 | ||
83 | status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES); | |
84 | if (ACPI_FAILURE(status)) { | |
85 | return_ACPI_STATUS(status); | |
86 | } | |
87 | ||
88 | /* | |
89 | * Find a free owner ID, cycle through all possible IDs on repeated | |
90 | * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have | |
91 | * to be scanned twice. | |
92 | */ | |
93 | for (i = 0, j = acpi_gbl_last_owner_id_index; | |
94 | i < (ACPI_NUM_OWNERID_MASKS + 1); i++, j++) { | |
95 | if (j >= ACPI_NUM_OWNERID_MASKS) { | |
96 | j = 0; /* Wraparound to start of mask array */ | |
97 | } | |
98 | ||
99 | for (k = acpi_gbl_next_owner_id_offset; k < 32; k++) { | |
100 | if (acpi_gbl_owner_id_mask[j] == ACPI_UINT32_MAX) { | |
101 | ||
102 | /* There are no free IDs in this mask */ | |
103 | ||
104 | break; | |
105 | } | |
106 | ||
107 | if (!(acpi_gbl_owner_id_mask[j] & (1 << k))) { | |
108 | /* | |
109 | * Found a free ID. The actual ID is the bit index plus one, | |
110 | * making zero an invalid Owner ID. Save this as the last ID | |
111 | * allocated and update the global ID mask. | |
112 | */ | |
113 | acpi_gbl_owner_id_mask[j] |= (1 << k); | |
114 | ||
115 | acpi_gbl_last_owner_id_index = (u8)j; | |
116 | acpi_gbl_next_owner_id_offset = (u8)(k + 1); | |
117 | ||
118 | /* | |
119 | * Construct encoded ID from the index and bit position | |
120 | * | |
121 | * Note: Last [j].k (bit 255) is never used and is marked | |
122 | * permanently allocated (prevents +1 overflow) | |
123 | */ | |
124 | *owner_id = | |
125 | (acpi_owner_id) ((k + 1) + ACPI_MUL_32(j)); | |
126 | ||
127 | ACPI_DEBUG_PRINT((ACPI_DB_VALUES, | |
128 | "Allocated OwnerId: %2.2X\n", | |
129 | (unsigned int)*owner_id)); | |
130 | goto exit; | |
131 | } | |
132 | } | |
133 | ||
134 | acpi_gbl_next_owner_id_offset = 0; | |
135 | } | |
136 | ||
137 | /* | |
138 | * All owner_ids have been allocated. This typically should | |
139 | * not happen since the IDs are reused after deallocation. The IDs are | |
140 | * allocated upon table load (one per table) and method execution, and | |
141 | * they are released when a table is unloaded or a method completes | |
142 | * execution. | |
143 | * | |
144 | * If this error happens, there may be very deep nesting of invoked control | |
145 | * methods, or there may be a bug where the IDs are not released. | |
146 | */ | |
147 | status = AE_OWNER_ID_LIMIT; | |
148 | ACPI_ERROR((AE_INFO, | |
149 | "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT")); | |
150 | ||
10622bf8 | 151 | exit: |
42f8fb75 BM |
152 | (void)acpi_ut_release_mutex(ACPI_MTX_CACHES); |
153 | return_ACPI_STATUS(status); | |
154 | } | |
155 | ||
156 | /******************************************************************************* | |
157 | * | |
158 | * FUNCTION: acpi_ut_release_owner_id | |
159 | * | |
160 | * PARAMETERS: owner_id_ptr - Pointer to a previously allocated owner_ID | |
161 | * | |
162 | * RETURN: None. No error is returned because we are either exiting a | |
163 | * control method or unloading a table. Either way, we would | |
164 | * ignore any error anyway. | |
165 | * | |
166 | * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255 | |
167 | * | |
168 | ******************************************************************************/ | |
169 | ||
170 | void acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr) | |
171 | { | |
172 | acpi_owner_id owner_id = *owner_id_ptr; | |
173 | acpi_status status; | |
174 | u32 index; | |
175 | u32 bit; | |
176 | ||
177 | ACPI_FUNCTION_TRACE_U32(ut_release_owner_id, owner_id); | |
178 | ||
179 | /* Always clear the input owner_id (zero is an invalid ID) */ | |
180 | ||
181 | *owner_id_ptr = 0; | |
182 | ||
183 | /* Zero is not a valid owner_ID */ | |
184 | ||
185 | if (owner_id == 0) { | |
186 | ACPI_ERROR((AE_INFO, "Invalid OwnerId: 0x%2.2X", owner_id)); | |
187 | return_VOID; | |
188 | } | |
189 | ||
190 | /* Mutex for the global ID mask */ | |
191 | ||
192 | status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES); | |
193 | if (ACPI_FAILURE(status)) { | |
194 | return_VOID; | |
195 | } | |
196 | ||
197 | /* Normalize the ID to zero */ | |
198 | ||
199 | owner_id--; | |
200 | ||
201 | /* Decode ID to index/offset pair */ | |
202 | ||
203 | index = ACPI_DIV_32(owner_id); | |
204 | bit = 1 << ACPI_MOD_32(owner_id); | |
205 | ||
206 | /* Free the owner ID only if it is valid */ | |
207 | ||
208 | if (acpi_gbl_owner_id_mask[index] & bit) { | |
209 | acpi_gbl_owner_id_mask[index] ^= bit; | |
210 | } else { | |
211 | ACPI_ERROR((AE_INFO, | |
212 | "Release of non-allocated OwnerId: 0x%2.2X", | |
213 | owner_id + 1)); | |
214 | } | |
215 | ||
216 | (void)acpi_ut_release_mutex(ACPI_MTX_CACHES); | |
217 | return_VOID; | |
218 | } |