xref: /openbmc/linux/drivers/acpi/acpica/tbutils.c (revision 8c749ce9)
1 /******************************************************************************
2  *
3  * Module Name: tbutils - ACPI Table utilities
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/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_check_dsdt_header
103  *
104  * PARAMETERS:  None
105  *
106  * RETURN:      None
107  *
108  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
109  *              if the DSDT has been replaced from outside the OS and/or if
110  *              the DSDT header has been corrupted.
111  *
112  ******************************************************************************/
113 
114 void acpi_tb_check_dsdt_header(void)
115 {
116 
117 	/* Compare original length and checksum to current values */
118 
119 	if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
120 	    acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
121 		ACPI_BIOS_ERROR((AE_INFO,
122 				 "The DSDT has been corrupted or replaced - "
123 				 "old, new headers below"));
124 
125 		acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
126 		acpi_tb_print_table_header(0, acpi_gbl_DSDT);
127 
128 		ACPI_ERROR((AE_INFO,
129 			    "Please send DMI info to linux-acpi@vger.kernel.org\n"
130 			    "If system does not work as expected, please boot with acpi=copy_dsdt"));
131 
132 		/* Disable further error messages */
133 
134 		acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
135 		acpi_gbl_original_dsdt_header.checksum =
136 		    acpi_gbl_DSDT->checksum;
137 	}
138 }
139 
140 /*******************************************************************************
141  *
142  * FUNCTION:    acpi_tb_copy_dsdt
143  *
144  * PARAMETERS:  table_desc          - Installed table to copy
145  *
146  * RETURN:      None
147  *
148  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
149  *              Some very bad BIOSs are known to either corrupt the DSDT or
150  *              install a new, bad DSDT. This copy works around the problem.
151  *
152  ******************************************************************************/
153 
154 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
155 {
156 	struct acpi_table_header *new_table;
157 	struct acpi_table_desc *table_desc;
158 
159 	table_desc = &acpi_gbl_root_table_list.tables[table_index];
160 
161 	new_table = ACPI_ALLOCATE(table_desc->length);
162 	if (!new_table) {
163 		ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
164 			    table_desc->length));
165 		return (NULL);
166 	}
167 
168 	memcpy(new_table, table_desc->pointer, table_desc->length);
169 	acpi_tb_uninstall_table(table_desc);
170 
171 	acpi_tb_init_table_descriptor(&acpi_gbl_root_table_list.
172 				      tables[acpi_gbl_dsdt_index],
173 				      ACPI_PTR_TO_PHYSADDR(new_table),
174 				      ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL,
175 				      new_table);
176 
177 	ACPI_INFO((AE_INFO,
178 		   "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
179 		   new_table->length));
180 
181 	return (new_table);
182 }
183 
184 /*******************************************************************************
185  *
186  * FUNCTION:    acpi_tb_get_root_table_entry
187  *
188  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
189  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
190  *
191  * RETURN:      Physical address extracted from the root table
192  *
193  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
194  *              both 32-bit and 64-bit platforms
195  *
196  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
197  *              64-bit platforms.
198  *
199  ******************************************************************************/
200 
201 static acpi_physical_address
202 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
203 {
204 	u64 address64;
205 
206 	/*
207 	 * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
208 	 * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
209 	 */
210 	if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) {
211 		/*
212 		 * 32-bit platform, RSDT: Return 32-bit table entry
213 		 * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
214 		 */
215 		return ((acpi_physical_address)
216 			(*ACPI_CAST_PTR(u32, table_entry)));
217 	} else {
218 		/*
219 		 * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
220 		 * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
221 		 *  return 64-bit
222 		 */
223 		ACPI_MOVE_64_TO_64(&address64, table_entry);
224 
225 #if ACPI_MACHINE_WIDTH == 32
226 		if (address64 > ACPI_UINT32_MAX) {
227 
228 			/* Will truncate 64-bit address to 32 bits, issue warning */
229 
230 			ACPI_BIOS_WARNING((AE_INFO,
231 					   "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
232 					   " truncating",
233 					   ACPI_FORMAT_UINT64(address64)));
234 		}
235 #endif
236 		return ((acpi_physical_address) (address64));
237 	}
238 }
239 
240 /*******************************************************************************
241  *
242  * FUNCTION:    acpi_tb_parse_root_table
243  *
244  * PARAMETERS:  rsdp                    - Pointer to the RSDP
245  *
246  * RETURN:      Status
247  *
248  * DESCRIPTION: This function is called to parse the Root System Description
249  *              Table (RSDT or XSDT)
250  *
251  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
252  *              be mapped and cannot be copied because it contains the actual
253  *              memory location of the ACPI Global Lock.
254  *
255  ******************************************************************************/
256 
257 acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
258 {
259 	struct acpi_table_rsdp *rsdp;
260 	u32 table_entry_size;
261 	u32 i;
262 	u32 table_count;
263 	struct acpi_table_header *table;
264 	acpi_physical_address address;
265 	u32 length;
266 	u8 *table_entry;
267 	acpi_status status;
268 	u32 table_index;
269 
270 	ACPI_FUNCTION_TRACE(tb_parse_root_table);
271 
272 	/* Map the entire RSDP and extract the address of the RSDT or XSDT */
273 
274 	rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
275 	if (!rsdp) {
276 		return_ACPI_STATUS(AE_NO_MEMORY);
277 	}
278 
279 	acpi_tb_print_table_header(rsdp_address,
280 				   ACPI_CAST_PTR(struct acpi_table_header,
281 						 rsdp));
282 
283 	/* Use XSDT if present and not overridden. Otherwise, use RSDT */
284 
285 	if ((rsdp->revision > 1) &&
286 	    rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
287 		/*
288 		 * RSDP contains an XSDT (64-bit physical addresses). We must use
289 		 * the XSDT if the revision is > 1 and the XSDT pointer is present,
290 		 * as per the ACPI specification.
291 		 */
292 		address = (acpi_physical_address) rsdp->xsdt_physical_address;
293 		table_entry_size = ACPI_XSDT_ENTRY_SIZE;
294 	} else {
295 		/* Root table is an RSDT (32-bit physical addresses) */
296 
297 		address = (acpi_physical_address) rsdp->rsdt_physical_address;
298 		table_entry_size = ACPI_RSDT_ENTRY_SIZE;
299 	}
300 
301 	/*
302 	 * It is not possible to map more than one entry in some environments,
303 	 * so unmap the RSDP here before mapping other tables
304 	 */
305 	acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
306 
307 	/* Map the RSDT/XSDT table header to get the full table length */
308 
309 	table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
310 	if (!table) {
311 		return_ACPI_STATUS(AE_NO_MEMORY);
312 	}
313 
314 	acpi_tb_print_table_header(address, table);
315 
316 	/*
317 	 * Validate length of the table, and map entire table.
318 	 * Minimum length table must contain at least one entry.
319 	 */
320 	length = table->length;
321 	acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
322 
323 	if (length < (sizeof(struct acpi_table_header) + table_entry_size)) {
324 		ACPI_BIOS_ERROR((AE_INFO,
325 				 "Invalid table length 0x%X in RSDT/XSDT",
326 				 length));
327 		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
328 	}
329 
330 	table = acpi_os_map_memory(address, length);
331 	if (!table) {
332 		return_ACPI_STATUS(AE_NO_MEMORY);
333 	}
334 
335 	/* Validate the root table checksum */
336 
337 	status = acpi_tb_verify_checksum(table, length);
338 	if (ACPI_FAILURE(status)) {
339 		acpi_os_unmap_memory(table, length);
340 		return_ACPI_STATUS(status);
341 	}
342 
343 	/* Get the number of entries and pointer to first entry */
344 
345 	table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
346 			    table_entry_size);
347 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
348 
349 	/* Initialize the root table array from the RSDT/XSDT */
350 
351 	for (i = 0; i < table_count; i++) {
352 
353 		/* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
354 
355 		address =
356 		    acpi_tb_get_root_table_entry(table_entry, table_entry_size);
357 
358 		/* Skip NULL entries in RSDT/XSDT */
359 
360 		if (!address) {
361 			goto next_table;
362 		}
363 
364 		status = acpi_tb_install_standard_table(address,
365 							ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
366 							FALSE, TRUE,
367 							&table_index);
368 
369 		if (ACPI_SUCCESS(status) &&
370 		    ACPI_COMPARE_NAME(&acpi_gbl_root_table_list.
371 				      tables[table_index].signature,
372 				      ACPI_SIG_FADT)) {
373 			acpi_gbl_fadt_index = table_index;
374 			acpi_tb_parse_fadt();
375 		}
376 
377 next_table:
378 
379 		table_entry += table_entry_size;
380 	}
381 
382 	acpi_os_unmap_memory(table, length);
383 	return_ACPI_STATUS(AE_OK);
384 }
385 
386 /*******************************************************************************
387  *
388  * FUNCTION:    acpi_is_valid_signature
389  *
390  * PARAMETERS:  signature           - Sig string to be validated
391  *
392  * RETURN:      TRUE if signature is has 4 valid ACPI characters
393  *
394  * DESCRIPTION: Validate an ACPI table signature.
395  *
396  ******************************************************************************/
397 
398 u8 acpi_is_valid_signature(char *signature)
399 {
400 	u32 i;
401 
402 	/* Validate each character in the signature */
403 
404 	for (i = 0; i < ACPI_NAME_SIZE; i++) {
405 		if (!acpi_ut_valid_acpi_char(signature[i], i)) {
406 			return (FALSE);
407 		}
408 	}
409 
410 	return (TRUE);
411 }
412