xref: /openbmc/linux/drivers/acpi/acpica/tbutils.c (revision 275876e2)
1 /******************************************************************************
2  *
3  * Module Name: tbutils - ACPI Table utilities
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 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "actables.h"
47 
48 #define _COMPONENT          ACPI_TABLES
49 ACPI_MODULE_NAME("tbutils")
50 
51 /* Local prototypes */
52 static acpi_physical_address
53 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
54 
55 #if (!ACPI_REDUCED_HARDWARE)
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_tb_initialize_facs
59  *
60  * PARAMETERS:  None
61  *
62  * RETURN:      Status
63  *
64  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
65  *              for accessing the Global Lock and Firmware Waking Vector
66  *
67  ******************************************************************************/
68 
69 acpi_status acpi_tb_initialize_facs(void)
70 {
71 	acpi_status status;
72 
73 	/* If Hardware Reduced flag is set, there is no FACS */
74 
75 	if (acpi_gbl_reduced_hardware) {
76 		acpi_gbl_FACS = NULL;
77 		return (AE_OK);
78 	}
79 
80 	status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
81 					 ACPI_CAST_INDIRECT_PTR(struct
82 								acpi_table_header,
83 								&acpi_gbl_FACS));
84 	return (status);
85 }
86 #endif				/* !ACPI_REDUCED_HARDWARE */
87 
88 /*******************************************************************************
89  *
90  * FUNCTION:    acpi_tb_tables_loaded
91  *
92  * PARAMETERS:  None
93  *
94  * RETURN:      TRUE if required ACPI tables are loaded
95  *
96  * DESCRIPTION: Determine if the minimum required ACPI tables are present
97  *              (FADT, FACS, DSDT)
98  *
99  ******************************************************************************/
100 
101 u8 acpi_tb_tables_loaded(void)
102 {
103 
104 	if (acpi_gbl_root_table_list.current_table_count >= 3) {
105 		return (TRUE);
106 	}
107 
108 	return (FALSE);
109 }
110 
111 /*******************************************************************************
112  *
113  * FUNCTION:    acpi_tb_check_dsdt_header
114  *
115  * PARAMETERS:  None
116  *
117  * RETURN:      None
118  *
119  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
120  *              if the DSDT has been replaced from outside the OS and/or if
121  *              the DSDT header has been corrupted.
122  *
123  ******************************************************************************/
124 
125 void acpi_tb_check_dsdt_header(void)
126 {
127 
128 	/* Compare original length and checksum to current values */
129 
130 	if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
131 	    acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
132 		ACPI_BIOS_ERROR((AE_INFO,
133 				 "The DSDT has been corrupted or replaced - "
134 				 "old, new headers below"));
135 		acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
136 		acpi_tb_print_table_header(0, acpi_gbl_DSDT);
137 
138 		ACPI_ERROR((AE_INFO,
139 			    "Please send DMI info to linux-acpi@vger.kernel.org\n"
140 			    "If system does not work as expected, please boot with acpi=copy_dsdt"));
141 
142 		/* Disable further error messages */
143 
144 		acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
145 		acpi_gbl_original_dsdt_header.checksum =
146 		    acpi_gbl_DSDT->checksum;
147 	}
148 }
149 
150 /*******************************************************************************
151  *
152  * FUNCTION:    acpi_tb_copy_dsdt
153  *
154  * PARAMETERS:  table_desc          - Installed table to copy
155  *
156  * RETURN:      None
157  *
158  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
159  *              Some very bad BIOSs are known to either corrupt the DSDT or
160  *              install a new, bad DSDT. This copy works around the problem.
161  *
162  ******************************************************************************/
163 
164 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
165 {
166 	struct acpi_table_header *new_table;
167 	struct acpi_table_desc *table_desc;
168 
169 	table_desc = &acpi_gbl_root_table_list.tables[table_index];
170 
171 	new_table = ACPI_ALLOCATE(table_desc->length);
172 	if (!new_table) {
173 		ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
174 			    table_desc->length));
175 		return (NULL);
176 	}
177 
178 	ACPI_MEMCPY(new_table, table_desc->pointer, table_desc->length);
179 	acpi_tb_uninstall_table(table_desc);
180 
181 	acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.
182 				      tables[ACPI_TABLE_INDEX_DSDT],
183 				      ACPI_PTR_TO_PHYSADDR(new_table),
184 				      ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
185 				      new_table);
186 
187 	ACPI_INFO((AE_INFO,
188 		   "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
189 		   new_table->length));
190 
191 	return (new_table);
192 }
193 
194 /*******************************************************************************
195  *
196  * FUNCTION:    acpi_tb_get_root_table_entry
197  *
198  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
199  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
200  *
201  * RETURN:      Physical address extracted from the root table
202  *
203  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
204  *              both 32-bit and 64-bit platforms
205  *
206  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
207  *              64-bit platforms.
208  *
209  ******************************************************************************/
210 
211 static acpi_physical_address
212 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
213 {
214 	u64 address64;
215 
216 	/*
217 	 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
218 	 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
219 	 */
220 	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
221 		/*
222 		 * 32-bit platform, RSDT: Return 32-bit table entry
223 		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
224 		 */
225 		return ((acpi_physical_address)
226 			(*ACPI_CAST_PTR(u32, table_entry)));
227 	} else {
228 		/*
229 		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
230 		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
231 		 *  return 64-bit
232 		 */
233 		ACPI_MOVE_64_TO_64(&address64, table_entry);
234 
235 #if ACPI_MACHINE_WIDTH == 32
236 		if (address64 > ACPI_UINT32_MAX) {
237 
238 			/* Will truncate 64-bit address to 32 bits, issue warning */
239 
240 			ACPI_BIOS_WARNING((AE_INFO,
241 					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
242 					   " truncating",
243 					   ACPI_FORMAT_UINT64(address64)));
244 		}
245 #endif
246 		return ((acpi_physical_address) (address64));
247 	}
248 }
249 
250 /*******************************************************************************
251  *
252  * FUNCTION:    acpi_tb_parse_root_table
253  *
254  * PARAMETERS:  rsdp                    - Pointer to the RSDP
255  *
256  * RETURN:      Status
257  *
258  * DESCRIPTION: This function is called to parse the Root System Description
259  *              Table (RSDT or XSDT)
260  *
261  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
262  *              be mapped and cannot be copied because it contains the actual
263  *              memory location of the ACPI Global Lock.
264  *
265  ******************************************************************************/
266 
267 acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
268 {
269 	struct acpi_table_rsdp *rsdp;
270 	u32 table_entry_size;
271 	u32 i;
272 	u32 table_count;
273 	struct acpi_table_header *table;
274 	acpi_physical_address address;
275 	u32 length;
276 	u8 *table_entry;
277 	acpi_status status;
278 	u32 table_index;
279 
280 	ACPI_FUNCTION_TRACE(tb_parse_root_table);
281 
282 	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
283 
284 	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
285 	if (!rsdp) {
286 		return_ACPI_STATUS(AE_NO_MEMORY);
287 	}
288 
289 	acpi_tb_print_table_header(rsdp_address,
290 				   ACPI_CAST_PTR(struct acpi_table_header,
291 						 rsdp));
292 
293 	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
294 
295 	if ((rsdp->revision > 1) &&
296 	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
297 		/*
298 		 * RSDP contains an XSDT (64-bit physical addresses). We must use
299 		 * the XSDT if the revision is > 1 and the XSDT pointer is present,
300 		 * as per the ACPI specification.
301 		 */
302 		address = (acpi_physical_address) rsdp->xsdt_physical_address;
303 		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
304 	} else {
305 		/* Root table is an RSDT (32-bit physical addresses) */
306 
307 		address = (acpi_physical_address) rsdp->rsdt_physical_address;
308 		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
309 	}
310 
311 	/*
312 	 * It is not possible to map more than one entry in some environments,
313 	 * so unmap the RSDP here before mapping other tables
314 	 */
315 	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
316 
317 	/* Map the RSDT/XSDT table header to get the full table length */
318 
319 	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
320 	if (!table) {
321 		return_ACPI_STATUS(AE_NO_MEMORY);
322 	}
323 
324 	acpi_tb_print_table_header(address, table);
325 
326 	/*
327 	 * Validate length of the table, and map entire table.
328 	 * Minimum length table must contain at least one entry.
329 	 */
330 	length = table->length;
331 	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
332 
333 	if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
334 		ACPI_BIOS_ERROR((AE_INFO,
335 				 "Invalid table length 0x%X in RSDT/XSDT",
336 				 length));
337 		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
338 	}
339 
340 	table = acpi_os_map_memory(address, length);
341 	if (!table) {
342 		return_ACPI_STATUS(AE_NO_MEMORY);
343 	}
344 
345 	/* Validate the root table checksum */
346 
347 	status = acpi_tb_verify_checksum(table, length);
348 	if (ACPI_FAILURE(status)) {
349 		acpi_os_unmap_memory(table, length);
350 		return_ACPI_STATUS(status);
351 	}
352 
353 	/* Get the number of entries and pointer to first entry */
354 
355 	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
356 			    table_entry_size);
357 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
358 
359 	/*
360 	 * First two entries in the table array are reserved for the DSDT
361 	 * and FACS, which are not actually present in the RSDT/XSDT - they
362 	 * come from the FADT
363 	 */
364 	acpi_gbl_root_table_list.current_table_count = 2;
365 
366 	/* Initialize the root table array from the RSDT/XSDT */
367 
368 	for (i = 0; i < table_count; i++) {
369 
370 		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
371 
372 		address =
373 		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
374 
375 		/* Skip NULL entries in RSDT/XSDT */
376 
377 		if (!address) {
378 			goto next_table;
379 		}
380 
381 		status = acpi_tb_install_standard_table(address,
382 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
383 							FALSE, TRUE,
384 							&table_index);
385 
386 		if (ACPI_SUCCESS(status) &&
387 		    ACPI_COMPARE_NAME(&acpi_gbl_root_table_list.
388 				      tables[table_index].signature,
389 				      ACPI_SIG_FADT)) {
390 			acpi_tb_parse_fadt(table_index);
391 		}
392 
393 next_table:
394 
395 		table_entry += table_entry_size;
396 	}
397 
398 	acpi_os_unmap_memory(table, length);
399 
400 	return_ACPI_STATUS(AE_OK);
401 }
402