reactos/drivers/bus/acpi/acpica/tables/tbxfroot.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbxfroot - Find the root ACPI table (RSDT)
   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 "actables.h"
  47
  48
  49 #define _COMPONENT          ACPI_TABLES
  50         ACPI_MODULE_NAME    ("tbxfroot")
  51
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    AcpiTbGetRsdpLength
  56  *
  57  * PARAMETERS:  Rsdp                - Pointer to RSDP
  58  *
  59  * RETURN:      Table length
  60  *
  61  * DESCRIPTION: Get the length of the RSDP
  62  *
  63  ******************************************************************************/
  64
  65 UINT32
  66 AcpiTbGetRsdpLength (
  67     ACPI_TABLE_RSDP         *Rsdp)
  68 {
  69
  70     if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature))
  71     {
  72         /* BAD Signature */
  73
  74         return (0);
  75     }
  76
  77     /* "Length" field is available if table version >= 2 */
  78
  79     if (Rsdp->Revision >= 2)
  80     {
  81         return (Rsdp->Length);
  82     }
  83     else
  84     {
  85         return (ACPI_RSDP_CHECKSUM_LENGTH);
  86     }
  87 }
  88
  89
  90 /*******************************************************************************
  91  *
  92  * FUNCTION:    AcpiTbValidateRsdp
  93  *
  94  * PARAMETERS:  Rsdp                - Pointer to unvalidated RSDP
  95  *
  96  * RETURN:      Status
  97  *
  98  * DESCRIPTION: Validate the RSDP (ptr)
  99  *
 100  ******************************************************************************/
 101
 102 ACPI_STATUS
 103 AcpiTbValidateRsdp (
 104     ACPI_TABLE_RSDP         *Rsdp)
 105 {
 106
 107     /*
 108      * The signature and checksum must both be correct
 109      *
 110      * Note: Sometimes there exists more than one RSDP in memory; the valid
 111      * RSDP has a valid checksum, all others have an invalid checksum.
 112      */
 113     if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature))
 114     {
 115         /* Nope, BAD Signature */
 116
 117         return (AE_BAD_SIGNATURE);
 118     }
 119
 120     /* Check the standard checksum */
 121
 122     if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0)
 123     {
 124         return (AE_BAD_CHECKSUM);
 125     }
 126
 127     /* Check extended checksum if table version >= 2 */
 128
 129     if ((Rsdp->Revision >= 2) &&
 130         (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0))
 131     {
 132         return (AE_BAD_CHECKSUM);
 133     }
 134
 135     return (AE_OK);
 136 }
 137
 138
 139 /*******************************************************************************
 140  *
 141  * FUNCTION:    AcpiFindRootPointer
 142  *
 143  * PARAMETERS:  TableAddress            - Where the table pointer is returned
 144  *
 145  * RETURN:      Status, RSDP physical address
 146  *
 147  * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor
 148  *              pointer structure. If it is found, set *RSDP to point to it.
 149  *
 150  * NOTE1:       The RSDP must be either in the first 1K of the Extended
 151  *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 152  *              Only a 32-bit physical address is necessary.
 153  *
 154  * NOTE2:       This function is always available, regardless of the
 155  *              initialization state of the rest of ACPI.
 156  *
 157  ******************************************************************************/
 158
 159 ACPI_STATUS ACPI_INIT_FUNCTION
 160 AcpiFindRootPointer (
 161     ACPI_PHYSICAL_ADDRESS   *TableAddress)
 162 {
 163     UINT8                   *TablePtr;
 164     UINT8                   *MemRover;
 165     UINT32                  PhysicalAddress;
 166
 167
 168     ACPI_FUNCTION_TRACE (AcpiFindRootPointer);
 169
 170
 171     /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
 172
 173     TablePtr = AcpiOsMapMemory (
 174         (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION,
 175         ACPI_EBDA_PTR_LENGTH);
 176     if (!TablePtr)
 177     {
 178         ACPI_ERROR ((AE_INFO,
 179             "Could not map memory at 0x%8.8X for length %u",
 180             ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
 181
 182         return_ACPI_STATUS (AE_NO_MEMORY);
 183     }
 184
 185     ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr);
 186
 187     /* Convert segment part to physical address */
 188
 189     PhysicalAddress <<= 4;
 190     AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH);
 191
 192     /* EBDA present? */
 193
 194     if (PhysicalAddress > 0x400)
 195     {
 196         /*
 197          * 1b) Search EBDA paragraphs (EBDA is required to be a
 198          *     minimum of 1K length)
 199          */
 200         TablePtr = AcpiOsMapMemory (
 201             (ACPI_PHYSICAL_ADDRESS) PhysicalAddress,
 202             ACPI_EBDA_WINDOW_SIZE);
 203         if (!TablePtr)
 204         {
 205             ACPI_ERROR ((AE_INFO,
 206                 "Could not map memory at 0x%8.8X for length %u",
 207                 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE));
 208
 209             return_ACPI_STATUS (AE_NO_MEMORY);
 210         }
 211
 212         MemRover = AcpiTbScanMemoryForRsdp (
 213             TablePtr, ACPI_EBDA_WINDOW_SIZE);
 214         AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE);
 215
 216         if (MemRover)
 217         {
 218             /* Return the physical address */
 219
 220             PhysicalAddress +=
 221                 (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr);
 222
 223             *TableAddress = (ACPI_PHYSICAL_ADDRESS) 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 (
 245         TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
 246     AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
 247
 248     if (MemRover)
 249     {
 250         /* Return the physical address */
 251
 252         PhysicalAddress = (UINT32)
 253             (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr));
 254
 255         *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress;
 256         return_ACPI_STATUS (AE_OK);
 257     }
 258
 259     /* A valid RSDP was not found */
 260
 261     ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found"));
 262     return_ACPI_STATUS (AE_NOT_FOUND);
 263 }
 264
 265 ACPI_EXPORT_SYMBOL_INIT (AcpiFindRootPointer)
 266
 267
 268 /*******************************************************************************
 269  *
 270  * FUNCTION:    AcpiTbScanMemoryForRsdp
 271  *
 272  * PARAMETERS:  StartAddress        - Starting pointer for search
 273  *              Length              - Maximum length to search
 274  *
 275  * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 276  *
 277  * DESCRIPTION: Search a block of memory for the RSDP signature
 278  *
 279  ******************************************************************************/
 280
 281 UINT8 *
 282 AcpiTbScanMemoryForRsdp (
 283     UINT8                   *StartAddress,
 284     UINT32                  Length)
 285 {
 286     ACPI_STATUS             Status;
 287     UINT8                   *MemRover;
 288     UINT8                   *EndAddress;
 289
 290
 291     ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp);
 292
 293
 294     EndAddress = StartAddress + Length;
 295
 296     /* Search from given start address for the requested length */
 297
 298     for (MemRover = StartAddress; MemRover < EndAddress;
 299          MemRover += ACPI_RSDP_SCAN_STEP)
 300     {
 301         /* The RSDP signature and checksum must both be correct */
 302
 303         Status = AcpiTbValidateRsdp (
 304             ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover));
 305         if (ACPI_SUCCESS (Status))
 306         {
 307             /* Sig and checksum valid, we have found a real RSDP */
 308
 309             ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 310                 "RSDP located at physical address %p\n", MemRover));
 311             return_PTR (MemRover);
 312         }
 313
 314         /* No sig match or bad checksum, keep searching */
 315     }
 316
 317     /* Searched entire block, no RSDP was found */
 318
 319     ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 320         "Searched entire block from %p, valid RSDP was not found\n",
 321         StartAddress));
 322     return_PTR (NULL);
 323 }