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.h" 45 #include "accommon.h" 46 #include "acnamesp.h" 47 48 49 #define _COMPONENT ACPI_UTILITIES 50 ACPI_MODULE_NAME ("utownerid") 51 52 53 /******************************************************************************* 54 * 55 * FUNCTION: AcpiUtAllocateOwnerId 56 * 57 * PARAMETERS: OwnerId - Where the new owner ID is returned 58 * 59 * RETURN: Status 60 * 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. 64 * 65 ******************************************************************************/ 66 67 ACPI_STATUS 68 AcpiUtAllocateOwnerId ( 69 ACPI_OWNER_ID *OwnerId) 70 { 71 UINT32 i; 72 UINT32 j; 73 UINT32 k; 74 ACPI_STATUS Status; 75 76 77 ACPI_FUNCTION_TRACE (UtAllocateOwnerId); 78 79 80 /* Guard against multiple allocations of ID to the same location */ 81 82 if (*OwnerId) 83 { 84 ACPI_ERROR ((AE_INFO, 85 "Owner ID [0x%2.2X] already exists", *OwnerId)); 86 return_ACPI_STATUS (AE_ALREADY_EXISTS); 87 } 88 89 /* Mutex for the global ID mask */ 90 91 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES); 92 if (ACPI_FAILURE (Status)) 93 { 94 return_ACPI_STATUS (Status); 95 } 96 97 /* 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. 101 */ 102 for (i = 0, j = AcpiGbl_LastOwnerIdIndex; 103 i < (ACPI_NUM_OWNERID_MASKS + 1); 104 i++, j++) 105 { 106 if (j >= ACPI_NUM_OWNERID_MASKS) 107 { 108 j = 0; /* Wraparound to start of mask array */ 109 } 110 111 for (k = AcpiGbl_NextOwnerIdOffset; k < 32; k++) 112 { 113 if (AcpiGbl_OwnerIdMask[j] == ACPI_UINT32_MAX) 114 { 115 /* There are no free IDs in this mask */ 116 117 break; 118 } 119 120 if (!(AcpiGbl_OwnerIdMask[j] & (1 << k))) 121 { 122 /* 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. 126 */ 127 AcpiGbl_OwnerIdMask[j] |= (1 << k); 128 129 AcpiGbl_LastOwnerIdIndex = (UINT8) j; 130 AcpiGbl_NextOwnerIdOffset = (UINT8) (k + 1); 131 132 /* 133 * Construct encoded ID from the index and bit position 134 * 135 * Note: Last [j].k (bit 255) is never used and is marked 136 * permanently allocated (prevents +1 overflow) 137 */ 138 *OwnerId = (ACPI_OWNER_ID) ((k + 1) + ACPI_MUL_32 (j)); 139 140 ACPI_DEBUG_PRINT ((ACPI_DB_VALUES, 141 "Allocated OwnerId: %2.2X\n", (unsigned int) *OwnerId)); 142 goto Exit; 143 } 144 } 145 146 AcpiGbl_NextOwnerIdOffset = 0; 147 } 148 149 /* 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 154 * execution. 155 * 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. 158 */ 159 Status = AE_OWNER_ID_LIMIT; 160 ACPI_ERROR ((AE_INFO, 161 "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT")); 162 163 Exit: 164 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES); 165 return_ACPI_STATUS (Status); 166 } 167 168 169 /******************************************************************************* 170 * 171 * FUNCTION: AcpiUtReleaseOwnerId 172 * 173 * PARAMETERS: OwnerIdPtr - Pointer to a previously allocated OwnerID 174 * 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. 178 * 179 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255 180 * 181 ******************************************************************************/ 182 183 void 184 AcpiUtReleaseOwnerId ( 185 ACPI_OWNER_ID *OwnerIdPtr) 186 { 187 ACPI_OWNER_ID OwnerId = *OwnerIdPtr; 188 ACPI_STATUS Status; 189 UINT32 Index; 190 UINT32 Bit; 191 192 193 ACPI_FUNCTION_TRACE_U32 (UtReleaseOwnerId, OwnerId); 194 195 196 /* Always clear the input OwnerId (zero is an invalid ID) */ 197 198 *OwnerIdPtr = 0; 199 200 /* Zero is not a valid OwnerID */ 201 202 if (OwnerId == 0) 203 { 204 ACPI_ERROR ((AE_INFO, "Invalid OwnerId: 0x%2.2X", OwnerId)); 205 return_VOID; 206 } 207 208 /* Mutex for the global ID mask */ 209 210 Status = AcpiUtAcquireMutex (ACPI_MTX_CACHES); 211 if (ACPI_FAILURE (Status)) 212 { 213 return_VOID; 214 } 215 216 /* Normalize the ID to zero */ 217 218 OwnerId--; 219 220 /* Decode ID to index/offset pair */ 221 222 Index = ACPI_DIV_32 (OwnerId); 223 Bit = 1 << ACPI_MOD_32 (OwnerId); 224 225 /* Free the owner ID only if it is valid */ 226 227 if (AcpiGbl_OwnerIdMask[Index] & Bit) 228 { 229 AcpiGbl_OwnerIdMask[Index] ^= Bit; 230 } 231 else 232 { 233 ACPI_ERROR ((AE_INFO, 234 "Release of non-allocated OwnerId: 0x%2.2X", OwnerId + 1)); 235 } 236 237 (void) AcpiUtReleaseMutex (ACPI_MTX_CACHES); 238 return_VOID; 239 } 240