Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Module Name: tbxfroot - Find the root ACPI table (RSDT) |
| 4 | * |
| 5 | *****************************************************************************/ |
| 6 | |
| 7 | /* |
Len Brown | 75a44ce | 2008-04-23 23:00:13 -0400 | [diff] [blame] | 8 | * Copyright (C) 2000 - 2008, Intel Corp. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #include <acpi/acpi.h> |
Len Brown | e2f7a77 | 2009-01-09 00:30:03 -0500 | [diff] [blame] | 45 | #include "accommon.h" |
| 46 | #include "actables.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | #define _COMPONENT ACPI_TABLES |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 49 | ACPI_MODULE_NAME("tbxfroot") |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 51 | /* Local prototypes */ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 52 | static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 54 | static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp); |
| 55 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | /******************************************************************************* |
| 57 | * |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 58 | * FUNCTION: acpi_tb_validate_rsdp |
| 59 | * |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 60 | * PARAMETERS: Rsdp - Pointer to unvalidated RSDP |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 61 | * |
| 62 | * RETURN: Status |
| 63 | * |
| 64 | * DESCRIPTION: Validate the RSDP (ptr) |
| 65 | * |
| 66 | ******************************************************************************/ |
| 67 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 68 | static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp) |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 69 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 70 | ACPI_FUNCTION_ENTRY(); |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 71 | |
| 72 | /* |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 73 | * The signature and checksum must both be correct |
| 74 | * |
| 75 | * Note: Sometimes there exists more than one RSDP in memory; the valid |
| 76 | * RSDP has a valid checksum, all others have an invalid checksum. |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 77 | */ |
Bob Moore | ec41f19 | 2009-02-18 15:03:30 +0800 | [diff] [blame] | 78 | if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP, |
| 79 | sizeof(ACPI_SIG_RSDP) - 1) != 0) { |
Bob Moore | 52fc0b0 | 2006-10-02 00:00:00 -0400 | [diff] [blame] | 80 | |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 81 | /* Nope, BAD Signature */ |
| 82 | |
| 83 | return (AE_BAD_SIGNATURE); |
| 84 | } |
| 85 | |
| 86 | /* Check the standard checksum */ |
| 87 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 88 | if (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) { |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 89 | return (AE_BAD_CHECKSUM); |
| 90 | } |
| 91 | |
| 92 | /* Check extended checksum if table version >= 2 */ |
| 93 | |
| 94 | if ((rsdp->revision >= 2) && |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 95 | (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) { |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 96 | return (AE_BAD_CHECKSUM); |
| 97 | } |
| 98 | |
| 99 | return (AE_OK); |
| 100 | } |
| 101 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | /******************************************************************************* |
| 103 | * |
Len Brown | 239665a | 2007-11-23 20:08:02 -0500 | [diff] [blame] | 104 | * FUNCTION: acpi_find_root_pointer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | * |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 106 | * PARAMETERS: table_address - Where the table pointer is returned |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | * |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 108 | * RETURN: Status, RSDP physical address |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | * |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 110 | * DESCRIPTION: Search lower 1_mbyte of memory for the root system descriptor |
| 111 | * pointer structure. If it is found, set *RSDP to point to it. |
| 112 | * |
| 113 | * NOTE1: The RSDP must be either in the first 1_k of the Extended |
| 114 | * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) |
| 115 | * Only a 32-bit physical address is necessary. |
| 116 | * |
| 117 | * NOTE2: This function is always available, regardless of the |
| 118 | * initialization state of the rest of ACPI. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | * |
| 120 | ******************************************************************************/ |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 121 | |
Bob Moore | 67a119f | 2008-06-10 13:42:13 +0800 | [diff] [blame] | 122 | acpi_status acpi_find_root_pointer(acpi_size *table_address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | { |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 124 | u8 *table_ptr; |
| 125 | u8 *mem_rover; |
| 126 | u32 physical_address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 128 | ACPI_FUNCTION_TRACE(acpi_find_root_pointer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 130 | /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 132 | table_ptr = acpi_os_map_memory((acpi_physical_address) |
| 133 | ACPI_EBDA_PTR_LOCATION, |
| 134 | ACPI_EBDA_PTR_LENGTH); |
| 135 | if (!table_ptr) { |
| 136 | ACPI_ERROR((AE_INFO, |
| 137 | "Could not map memory at %8.8X for length %X", |
| 138 | ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 139 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 140 | return_ACPI_STATUS(AE_NO_MEMORY); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | } |
| 142 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 143 | ACPI_MOVE_16_TO_32(&physical_address, table_ptr); |
| 144 | |
| 145 | /* Convert segment part to physical address */ |
| 146 | |
| 147 | physical_address <<= 4; |
| 148 | acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH); |
| 149 | |
| 150 | /* EBDA present? */ |
| 151 | |
| 152 | if (physical_address > 0x400) { |
| 153 | /* |
| 154 | * 1b) Search EBDA paragraphs (EBDA is required to be a |
| 155 | * minimum of 1_k length) |
| 156 | */ |
Bob Moore | 67a119f | 2008-06-10 13:42:13 +0800 | [diff] [blame] | 157 | table_ptr = acpi_os_map_memory((acpi_physical_address) |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 158 | physical_address, |
| 159 | ACPI_EBDA_WINDOW_SIZE); |
| 160 | if (!table_ptr) { |
| 161 | ACPI_ERROR((AE_INFO, |
| 162 | "Could not map memory at %8.8X for length %X", |
| 163 | physical_address, ACPI_EBDA_WINDOW_SIZE)); |
| 164 | |
| 165 | return_ACPI_STATUS(AE_NO_MEMORY); |
| 166 | } |
| 167 | |
| 168 | mem_rover = |
| 169 | acpi_tb_scan_memory_for_rsdp(table_ptr, |
| 170 | ACPI_EBDA_WINDOW_SIZE); |
| 171 | acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE); |
| 172 | |
| 173 | if (mem_rover) { |
| 174 | |
| 175 | /* Return the physical address */ |
| 176 | |
| 177 | physical_address += |
| 178 | (u32) ACPI_PTR_DIFF(mem_rover, table_ptr); |
| 179 | |
| 180 | *table_address = physical_address; |
| 181 | return_ACPI_STATUS(AE_OK); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh |
| 187 | */ |
| 188 | table_ptr = acpi_os_map_memory((acpi_physical_address) |
| 189 | ACPI_HI_RSDP_WINDOW_BASE, |
| 190 | ACPI_HI_RSDP_WINDOW_SIZE); |
| 191 | |
| 192 | if (!table_ptr) { |
| 193 | ACPI_ERROR((AE_INFO, |
| 194 | "Could not map memory at %8.8X for length %X", |
| 195 | ACPI_HI_RSDP_WINDOW_BASE, |
| 196 | ACPI_HI_RSDP_WINDOW_SIZE)); |
| 197 | |
| 198 | return_ACPI_STATUS(AE_NO_MEMORY); |
| 199 | } |
| 200 | |
| 201 | mem_rover = |
| 202 | acpi_tb_scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE); |
| 203 | acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE); |
| 204 | |
| 205 | if (mem_rover) { |
| 206 | |
| 207 | /* Return the physical address */ |
| 208 | |
| 209 | physical_address = (u32) |
| 210 | (ACPI_HI_RSDP_WINDOW_BASE + |
| 211 | ACPI_PTR_DIFF(mem_rover, table_ptr)); |
| 212 | |
| 213 | *table_address = physical_address; |
| 214 | return_ACPI_STATUS(AE_OK); |
| 215 | } |
| 216 | |
| 217 | /* A valid RSDP was not found */ |
| 218 | |
| 219 | ACPI_ERROR((AE_INFO, "A valid RSDP was not found")); |
| 220 | return_ACPI_STATUS(AE_NOT_FOUND); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | } |
| 222 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | /******************************************************************************* |
| 224 | * |
| 225 | * FUNCTION: acpi_tb_scan_memory_for_rsdp |
| 226 | * |
| 227 | * PARAMETERS: start_address - Starting pointer for search |
| 228 | * Length - Maximum length to search |
| 229 | * |
| 230 | * RETURN: Pointer to the RSDP if found, otherwise NULL. |
| 231 | * |
| 232 | * DESCRIPTION: Search a block of memory for the RSDP signature |
| 233 | * |
| 234 | ******************************************************************************/ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 235 | static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 237 | acpi_status status; |
| 238 | u8 *mem_rover; |
| 239 | u8 *end_address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 241 | ACPI_FUNCTION_TRACE(tb_scan_memory_for_rsdp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
| 243 | end_address = start_address + length; |
| 244 | |
| 245 | /* Search from given start address for the requested length */ |
| 246 | |
| 247 | for (mem_rover = start_address; mem_rover < end_address; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 248 | mem_rover += ACPI_RSDP_SCAN_STEP) { |
Bob Moore | 52fc0b0 | 2006-10-02 00:00:00 -0400 | [diff] [blame] | 249 | |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 250 | /* The RSDP signature and checksum must both be correct */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 252 | status = |
| 253 | acpi_tb_validate_rsdp(ACPI_CAST_PTR |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 254 | (struct acpi_table_rsdp, mem_rover)); |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 255 | if (ACPI_SUCCESS(status)) { |
Bob Moore | 52fc0b0 | 2006-10-02 00:00:00 -0400 | [diff] [blame] | 256 | |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 257 | /* Sig and checksum valid, we have found a real RSDP */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 259 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 260 | "RSDP located at physical address %p\n", |
| 261 | mem_rover)); |
| 262 | return_PTR(mem_rover); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | } |
| 264 | |
Robert Moore | f9f4601 | 2005-07-08 00:00:00 -0400 | [diff] [blame] | 265 | /* No sig match or bad checksum, keep searching */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | } |
| 267 | |
| 268 | /* Searched entire block, no RSDP was found */ |
| 269 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 270 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
| 271 | "Searched entire block from %p, valid RSDP was not found\n", |
| 272 | start_address)); |
| 273 | return_PTR(NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | } |