xref: /titanic_44/usr/src/cmd/acpi/acpidump/tbxfroot.c (revision 48a4016cae8aa2b8b3d8b258eb22e0c781912bed)
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
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 (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 }
324