1 /****************************************************************************** 2 * 3 * Module Name: tbxfroot - Find the root ACPI table (RSDT) 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 #define __TBXFROOT_C__ 45 46 #include <contrib/dev/acpica/include/acpi.h> 47 #include <contrib/dev/acpica/include/accommon.h> 48 #include <contrib/dev/acpica/include/actables.h> 49 50 51 #define _COMPONENT ACPI_TABLES 52 ACPI_MODULE_NAME ("tbxfroot") 53 54 55 /******************************************************************************* 56 * 57 * FUNCTION: AcpiTbGetRsdpLength 58 * 59 * PARAMETERS: Rsdp - Pointer to RSDP 60 * 61 * RETURN: Table length 62 * 63 * DESCRIPTION: Get the length of the RSDP 64 * 65 ******************************************************************************/ 66 67 UINT32 68 AcpiTbGetRsdpLength ( 69 ACPI_TABLE_RSDP *Rsdp) 70 { 71 72 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 73 { 74 /* BAD Signature */ 75 76 return (0); 77 } 78 79 /* "Length" field is available if table version >= 2 */ 80 81 if (Rsdp->Revision >= 2) 82 { 83 return (Rsdp->Length); 84 } 85 else 86 { 87 return (ACPI_RSDP_CHECKSUM_LENGTH); 88 } 89 } 90 91 92 /******************************************************************************* 93 * 94 * FUNCTION: AcpiTbValidateRsdp 95 * 96 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP 97 * 98 * RETURN: Status 99 * 100 * DESCRIPTION: Validate the RSDP (ptr) 101 * 102 ******************************************************************************/ 103 104 ACPI_STATUS 105 AcpiTbValidateRsdp ( 106 ACPI_TABLE_RSDP *Rsdp) 107 { 108 109 /* 110 * The signature and checksum must both be correct 111 * 112 * Note: Sometimes there exists more than one RSDP in memory; the valid 113 * RSDP has a valid checksum, all others have an invalid checksum. 114 */ 115 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 116 { 117 /* Nope, BAD Signature */ 118 119 return (AE_BAD_SIGNATURE); 120 } 121 122 /* Check the standard checksum */ 123 124 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) 125 { 126 return (AE_BAD_CHECKSUM); 127 } 128 129 /* Check extended checksum if table version >= 2 */ 130 131 if ((Rsdp->Revision >= 2) && 132 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) 133 { 134 return (AE_BAD_CHECKSUM); 135 } 136 137 return (AE_OK); 138 } 139 140 141 /******************************************************************************* 142 * 143 * FUNCTION: AcpiFindRootPointer 144 * 145 * PARAMETERS: TableAddress - Where the table pointer is returned 146 * 147 * RETURN: Status, RSDP physical address 148 * 149 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor 150 * pointer structure. If it is found, set *RSDP to point to it. 151 * 152 * NOTE1: The RSDP must be either in the first 1K of the Extended 153 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) 154 * Only a 32-bit physical address is necessary. 155 * 156 * NOTE2: This function is always available, regardless of the 157 * initialization state of the rest of ACPI. 158 * 159 ******************************************************************************/ 160 161 ACPI_STATUS 162 AcpiFindRootPointer ( 163 ACPI_SIZE *TableAddress) 164 { 165 UINT8 *TablePtr; 166 UINT8 *MemRover; 167 UINT32 PhysicalAddress; 168 169 170 ACPI_FUNCTION_TRACE (AcpiFindRootPointer); 171 172 173 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ 174 175 TablePtr = AcpiOsMapMemory ( 176 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, 177 ACPI_EBDA_PTR_LENGTH); 178 if (!TablePtr) 179 { 180 ACPI_ERROR ((AE_INFO, 181 "Could not map memory at 0x%8.8X for length %u", 182 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); 183 184 return_ACPI_STATUS (AE_NO_MEMORY); 185 } 186 187 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); 188 189 /* Convert segment part to physical address */ 190 191 PhysicalAddress <<= 4; 192 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); 193 194 /* EBDA present? */ 195 196 if (PhysicalAddress > 0x400) 197 { 198 /* 199 * 1b) Search EBDA paragraphs (EBDA is required to be a 200 * minimum of 1K length) 201 */ 202 TablePtr = AcpiOsMapMemory ( 203 (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, 204 ACPI_EBDA_WINDOW_SIZE); 205 if (!TablePtr) 206 { 207 ACPI_ERROR ((AE_INFO, 208 "Could not map memory at 0x%8.8X for length %u", 209 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); 210 211 return_ACPI_STATUS (AE_NO_MEMORY); 212 } 213 214 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE); 215 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); 216 217 if (MemRover) 218 { 219 /* Return the physical address */ 220 221 PhysicalAddress += (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); 222 223 *TableAddress = PhysicalAddress; 224 return_ACPI_STATUS (AE_OK); 225 } 226 } 227 228 /* 229 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh 230 */ 231 TablePtr = AcpiOsMapMemory ( 232 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, 233 ACPI_HI_RSDP_WINDOW_SIZE); 234 235 if (!TablePtr) 236 { 237 ACPI_ERROR ((AE_INFO, 238 "Could not map memory at 0x%8.8X for length %u", 239 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); 240 241 return_ACPI_STATUS (AE_NO_MEMORY); 242 } 243 244 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 245 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 246 247 if (MemRover) 248 { 249 /* Return the physical address */ 250 251 PhysicalAddress = (UINT32) 252 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); 253 254 *TableAddress = PhysicalAddress; 255 return_ACPI_STATUS (AE_OK); 256 } 257 258 /* A valid RSDP was not found */ 259 260 ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found")); 261 return_ACPI_STATUS (AE_NOT_FOUND); 262 } 263 264 ACPI_EXPORT_SYMBOL (AcpiFindRootPointer) 265 266 267 /******************************************************************************* 268 * 269 * FUNCTION: AcpiTbScanMemoryForRsdp 270 * 271 * PARAMETERS: StartAddress - Starting pointer for search 272 * Length - Maximum length to search 273 * 274 * RETURN: Pointer to the RSDP if found, otherwise NULL. 275 * 276 * DESCRIPTION: Search a block of memory for the RSDP signature 277 * 278 ******************************************************************************/ 279 280 UINT8 * 281 AcpiTbScanMemoryForRsdp ( 282 UINT8 *StartAddress, 283 UINT32 Length) 284 { 285 ACPI_STATUS Status; 286 UINT8 *MemRover; 287 UINT8 *EndAddress; 288 289 290 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); 291 292 293 EndAddress = StartAddress + Length; 294 295 /* Search from given start address for the requested length */ 296 297 for (MemRover = StartAddress; MemRover < EndAddress; 298 MemRover += ACPI_RSDP_SCAN_STEP) 299 { 300 /* The RSDP signature and checksum must both be correct */ 301 302 Status = AcpiTbValidateRsdp (ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); 303 if (ACPI_SUCCESS (Status)) 304 { 305 /* Sig and checksum valid, we have found a real RSDP */ 306 307 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 308 "RSDP located at physical address %p\n", MemRover)); 309 return_PTR (MemRover); 310 } 311 312 /* No sig match or bad checksum, keep searching */ 313 } 314 315 /* Searched entire block, no RSDP was found */ 316 317 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 318 "Searched entire block from %p, valid RSDP was not found\n", 319 StartAddress)); 320 return_PTR (NULL); 321 } 322