1 /*******************************************************************************
2 *
3 * Module Name: utownerid - Support for Table/Method Owner IDs
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2016, 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 #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 ******************************************************************************/
acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)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,
77 "Owner ID [0x%2.2X] already exists", *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
91 * may have 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
145 * control 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
151 exit:
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
acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr)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 }
219