xref: /openbmc/linux/drivers/acpi/acpica/tbutils.c (revision eb3fcf007fffe5830d815e713591f3e858f2a365)
1 /******************************************************************************
2  *
3  * Module Name: tbutils - ACPI Table utilities
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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 	struct acpi_table_facs *facs;
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 	} else if (acpi_gbl_FADT.Xfacs &&
79 		   (!acpi_gbl_FADT.facs
80 		    || !acpi_gbl_use32_bit_facs_addresses)) {
81 		(void)acpi_get_table_by_index(acpi_gbl_xfacs_index,
82 					      ACPI_CAST_INDIRECT_PTR(struct
83 								     acpi_table_header,
84 								     &facs));
85 		acpi_gbl_FACS = facs;
86 	} else if (acpi_gbl_FADT.facs) {
87 		(void)acpi_get_table_by_index(acpi_gbl_facs_index,
88 					      ACPI_CAST_INDIRECT_PTR(struct
89 								     acpi_table_header,
90 								     &facs));
91 		acpi_gbl_FACS = facs;
92 	}
93 
94 	/* If there is no FACS, just continue. There was already an error msg */
95 
96 	return (AE_OK);
97 }
98 #endif				/* !ACPI_REDUCED_HARDWARE */
99 
100 /*******************************************************************************
101  *
102  * FUNCTION:    acpi_tb_tables_loaded
103  *
104  * PARAMETERS:  None
105  *
106  * RETURN:      TRUE if required ACPI tables are loaded
107  *
108  * DESCRIPTION: Determine if the minimum required ACPI tables are present
109  *              (FADT, FACS, DSDT)
110  *
111  ******************************************************************************/
112 
113 u8 acpi_tb_tables_loaded(void)
114 {
115 
116 	if (acpi_gbl_root_table_list.current_table_count >= 4) {
117 		return (TRUE);
118 	}
119 
120 	return (FALSE);
121 }
122 
123 /*******************************************************************************
124  *
125  * FUNCTION:    acpi_tb_check_dsdt_header
126  *
127  * PARAMETERS:  None
128  *
129  * RETURN:      None
130  *
131  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
132  *              if the DSDT has been replaced from outside the OS and/or if
133  *              the DSDT header has been corrupted.
134  *
135  ******************************************************************************/
136 
137 void acpi_tb_check_dsdt_header(void)
138 {
139 
140 	/* Compare original length and checksum to current values */
141 
142 	if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
143 	    acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
144 		ACPI_BIOS_ERROR((AE_INFO,
145 				 "The DSDT has been corrupted or replaced - "
146 				 "old, new headers below"));
147 		acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
148 		acpi_tb_print_table_header(0, acpi_gbl_DSDT);
149 
150 		ACPI_ERROR((AE_INFO,
151 			    "Please send DMI info to linux-acpi@vger.kernel.org\n"
152 			    "If system does not work as expected, please boot with acpi=copy_dsdt"));
153 
154 		/* Disable further error messages */
155 
156 		acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
157 		acpi_gbl_original_dsdt_header.checksum =
158 		    acpi_gbl_DSDT->checksum;
159 	}
160 }
161 
162 /*******************************************************************************
163  *
164  * FUNCTION:    acpi_tb_copy_dsdt
165  *
166  * PARAMETERS:  table_desc          - Installed table to copy
167  *
168  * RETURN:      None
169  *
170  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
171  *              Some very bad BIOSs are known to either corrupt the DSDT or
172  *              install a new, bad DSDT. This copy works around the problem.
173  *
174  ******************************************************************************/
175 
176 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
177 {
178 	struct acpi_table_header *new_table;
179 	struct acpi_table_desc *table_desc;
180 
181 	table_desc = &acpi_gbl_root_table_list.tables[table_index];
182 
183 	new_table = ACPI_ALLOCATE(table_desc->length);
184 	if (!new_table) {
185 		ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
186 			    table_desc->length));
187 		return (NULL);
188 	}
189 
190 	memcpy(new_table, table_desc->pointer, table_desc->length);
191 	acpi_tb_uninstall_table(table_desc);
192 
193 	acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.
194 				      tables[acpi_gbl_dsdt_index],
195 				      ACPI_PTR_TO_PHYSADDR(new_table),
196 				      ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
197 				      new_table);
198 
199 	ACPI_INFO((AE_INFO,
200 		   "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
201 		   new_table->length));
202 
203 	return (new_table);
204 }
205 
206 /*******************************************************************************
207  *
208  * FUNCTION:    acpi_tb_get_root_table_entry
209  *
210  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
211  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
212  *
213  * RETURN:      Physical address extracted from the root table
214  *
215  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
216  *              both 32-bit and 64-bit platforms
217  *
218  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
219  *              64-bit platforms.
220  *
221  ******************************************************************************/
222 
223 static acpi_physical_address
224 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
225 {
226 	u64 address64;
227 
228 	/*
229 	 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
230 	 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
231 	 */
232 	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
233 		/*
234 		 * 32-bit platform, RSDT: Return 32-bit table entry
235 		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
236 		 */
237 		return ((acpi_physical_address)
238 			(*ACPI_CAST_PTR(u32, table_entry)));
239 	} else {
240 		/*
241 		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
242 		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
243 		 *  return 64-bit
244 		 */
245 		ACPI_MOVE_64_TO_64(&address64, table_entry);
246 
247 #if ACPI_MACHINE_WIDTH == 32
248 		if (address64 > ACPI_UINT32_MAX) {
249 
250 			/* Will truncate 64-bit address to 32 bits, issue warning */
251 
252 			ACPI_BIOS_WARNING((AE_INFO,
253 					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
254 					   " truncating",
255 					   ACPI_FORMAT_UINT64(address64)));
256 		}
257 #endif
258 		return ((acpi_physical_address) (address64));
259 	}
260 }
261 
262 /*******************************************************************************
263  *
264  * FUNCTION:    acpi_tb_parse_root_table
265  *
266  * PARAMETERS:  rsdp                    - Pointer to the RSDP
267  *
268  * RETURN:      Status
269  *
270  * DESCRIPTION: This function is called to parse the Root System Description
271  *              Table (RSDT or XSDT)
272  *
273  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
274  *              be mapped and cannot be copied because it contains the actual
275  *              memory location of the ACPI Global Lock.
276  *
277  ******************************************************************************/
278 
279 acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
280 {
281 	struct acpi_table_rsdp *rsdp;
282 	u32 table_entry_size;
283 	u32 i;
284 	u32 table_count;
285 	struct acpi_table_header *table;
286 	acpi_physical_address address;
287 	u32 length;
288 	u8 *table_entry;
289 	acpi_status status;
290 	u32 table_index;
291 
292 	ACPI_FUNCTION_TRACE(tb_parse_root_table);
293 
294 	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
295 
296 	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
297 	if (!rsdp) {
298 		return_ACPI_STATUS(AE_NO_MEMORY);
299 	}
300 
301 	acpi_tb_print_table_header(rsdp_address,
302 				   ACPI_CAST_PTR(struct acpi_table_header,
303 						 rsdp));
304 
305 	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
306 
307 	if ((rsdp->revision > 1) &&
308 	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
309 		/*
310 		 * RSDP contains an XSDT (64-bit physical addresses). We must use
311 		 * the XSDT if the revision is > 1 and the XSDT pointer is present,
312 		 * as per the ACPI specification.
313 		 */
314 		address = (acpi_physical_address) rsdp->xsdt_physical_address;
315 		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
316 	} else {
317 		/* Root table is an RSDT (32-bit physical addresses) */
318 
319 		address = (acpi_physical_address) rsdp->rsdt_physical_address;
320 		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
321 	}
322 
323 	/*
324 	 * It is not possible to map more than one entry in some environments,
325 	 * so unmap the RSDP here before mapping other tables
326 	 */
327 	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
328 
329 	/* Map the RSDT/XSDT table header to get the full table length */
330 
331 	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
332 	if (!table) {
333 		return_ACPI_STATUS(AE_NO_MEMORY);
334 	}
335 
336 	acpi_tb_print_table_header(address, table);
337 
338 	/*
339 	 * Validate length of the table, and map entire table.
340 	 * Minimum length table must contain at least one entry.
341 	 */
342 	length = table->length;
343 	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
344 
345 	if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
346 		ACPI_BIOS_ERROR((AE_INFO,
347 				 "Invalid table length 0x%X in RSDT/XSDT",
348 				 length));
349 		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
350 	}
351 
352 	table = acpi_os_map_memory(address, length);
353 	if (!table) {
354 		return_ACPI_STATUS(AE_NO_MEMORY);
355 	}
356 
357 	/* Validate the root table checksum */
358 
359 	status = acpi_tb_verify_checksum(table, length);
360 	if (ACPI_FAILURE(status)) {
361 		acpi_os_unmap_memory(table, length);
362 		return_ACPI_STATUS(status);
363 	}
364 
365 	/* Get the number of entries and pointer to first entry */
366 
367 	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
368 			    table_entry_size);
369 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
370 
371 	/* Initialize the root table array from the RSDT/XSDT */
372 
373 	for (i = 0; i < table_count; i++) {
374 
375 		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
376 
377 		address =
378 		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
379 
380 		/* Skip NULL entries in RSDT/XSDT */
381 
382 		if (!address) {
383 			goto next_table;
384 		}
385 
386 		status = acpi_tb_install_standard_table(address,
387 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
388 							FALSE, TRUE,
389 							&table_index);
390 
391 		if (ACPI_SUCCESS(status) &&
392 		    ACPI_COMPARE_NAME(&acpi_gbl_root_table_list.
393 				      tables[table_index].signature,
394 				      ACPI_SIG_FADT)) {
395 			acpi_tb_parse_fadt(table_index);
396 		}
397 
398 next_table:
399 
400 		table_entry += table_entry_size;
401 	}
402 
403 	acpi_os_unmap_memory(table, length);
404 
405 	return_ACPI_STATUS(AE_OK);
406 }
407 
408 /*******************************************************************************
409  *
410  * FUNCTION:    acpi_is_valid_signature
411  *
412  * PARAMETERS:  signature           - Sig string to be validated
413  *
414  * RETURN:      TRUE if signature is correct length and has valid characters
415  *
416  * DESCRIPTION: Validate an ACPI table signature.
417  *
418  ******************************************************************************/
419 
420 u8 acpi_is_valid_signature(char *signature)
421 {
422 	u32 i;
423 
424 	/* Validate the signature length */
425 
426 	if (strlen(signature) != ACPI_NAME_SIZE) {
427 		return (FALSE);
428 	}
429 
430 	/* Validate each character in the signature */
431 
432 	for (i = 0; i < ACPI_NAME_SIZE; i++) {
433 		if (!acpi_ut_valid_acpi_char(signature[i], i)) {
434 			return (FALSE);
435 		}
436 	}
437 
438 	return (TRUE);
439 }
440