[deliverable/linux.git] / drivers / acpi / tables / tbutils.c

/******************************************************************************
 *
 * Module Name: tbutils - Table manipulation utilities
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/actables.h>

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbutils")

/* Local prototypes */
#ifdef ACPI_OBSOLETE_FUNCTIONS
acpi_status
acpi_tb_handle_to_object(u16 table_id, struct acpi_table_desc **table_desc);
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_is_table_installed
 *
 * PARAMETERS:  new_table_desc      - Descriptor for new table being installed
 *
 * RETURN:      Status - AE_ALREADY_EXISTS if the table is already installed
 *
 * DESCRIPTION: Determine if an ACPI table is already installed
 *
 * MUTEX:       Table data structures should be locked
 *
 ******************************************************************************/

acpi_status acpi_tb_is_table_installed(struct acpi_table_desc *new_table_desc)
{
	struct acpi_table_desc *table_desc;

	ACPI_FUNCTION_TRACE("tb_is_table_installed");

	/* Get the list descriptor and first table descriptor */

	table_desc = acpi_gbl_table_lists[new_table_desc->type].next;

	/* Examine all installed tables of this type */

	while (table_desc) {
		/*
		 * If the table lengths match, perform a full bytewise compare. This
		 * means that we will allow tables with duplicate oem_table_id(s), as
		 * long as the tables are different in some way.
		 *
		 * Checking if the table has been loaded into the namespace means that
		 * we don't check for duplicate tables during the initial installation
		 * of tables within the RSDT/XSDT.
		 */
		if ((table_desc->loaded_into_namespace) &&
		    (table_desc->pointer->length ==
		     new_table_desc->pointer->length)
		    &&
		    (!ACPI_MEMCMP
		     ((const char *)table_desc->pointer,
		      (const char *)new_table_desc->pointer,
		      (acpi_size) new_table_desc->pointer->length))) {
			/* Match: this table is already installed */

			ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
					  "Table [%4.4s] already installed: Rev %X oem_table_id [%8.8s]\n",
					  new_table_desc->pointer->signature,
					  new_table_desc->pointer->revision,
					  new_table_desc->pointer->
					  oem_table_id));

			new_table_desc->owner_id = table_desc->owner_id;
			new_table_desc->installed_desc = table_desc;

			return_ACPI_STATUS(AE_ALREADY_EXISTS);
		}

		/* Get next table on the list */

		table_desc = table_desc->next;
	}

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_table_header
 *
 * PARAMETERS:  table_header        - Logical pointer to the table
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Check an ACPI table header for validity
 *
 * NOTE:  Table pointers are validated as follows:
 *          1) Table pointer must point to valid physical memory
 *          2) Signature must be 4 ASCII chars, even if we don't recognize the
 *             name
 *          3) Table must be readable for length specified in the header
 *          4) Table checksum must be valid (with the exception of the FACS
 *              which has no checksum because it contains variable fields)
 *
 ******************************************************************************/

acpi_status
acpi_tb_validate_table_header(struct acpi_table_header *table_header)
{
	acpi_name signature;

	ACPI_FUNCTION_NAME("tb_validate_table_header");

	/* Verify that this is a valid address */

	if (!acpi_os_readable(table_header, sizeof(struct acpi_table_header))) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Cannot read table header at %p\n",
				  table_header));

		return (AE_BAD_ADDRESS);
	}

	/* Ensure that the signature is 4 ASCII characters */

	ACPI_MOVE_32_TO_32(&signature, table_header->signature);
	if (!acpi_ut_valid_acpi_name(signature)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Table signature at %p [%p] has invalid characters\n",
				  table_header, &signature));

		ACPI_REPORT_WARNING(("Invalid table signature found: [%4.4s]\n",
				     (char *)&signature));

		ACPI_DUMP_BUFFER(table_header,
				 sizeof(struct acpi_table_header));
		return (AE_BAD_SIGNATURE);
	}

	/* Validate the table length */

	if (table_header->length < sizeof(struct acpi_table_header)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Invalid length in table header %p name %4.4s\n",
				  table_header, (char *)&signature));

		ACPI_REPORT_WARNING(("Invalid table header length (0x%X) found\n", (u32) table_header->length));

		ACPI_DUMP_BUFFER(table_header,
				 sizeof(struct acpi_table_header));
		return (AE_BAD_HEADER);
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_verify_table_checksum
 *
 * PARAMETERS:  *table_header           - ACPI table to verify
 *
 * RETURN:      8 bit checksum of table
 *
 * DESCRIPTION: Does an 8 bit checksum of table and returns status.  A correct
 *              table should have a checksum of 0.
 *
 ******************************************************************************/

acpi_status
acpi_tb_verify_table_checksum(struct acpi_table_header * table_header)
{
	u8 checksum;
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE("tb_verify_table_checksum");

	/* Compute the checksum on the table */

	checksum =
	    acpi_tb_generate_checksum(table_header, table_header->length);

	/* Return the appropriate exception */

	if (checksum) {
		ACPI_REPORT_WARNING(("Invalid checksum in table [%4.4s] (%02X, sum %02X is not zero)\n", table_header->signature, (u32) table_header->checksum, (u32) checksum));

		status = AE_BAD_CHECKSUM;
	}
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_generate_checksum
 *
 * PARAMETERS:  Buffer              - Buffer to checksum
 *              Length              - Size of the buffer
 *
 * RETURN:      8 bit checksum of buffer
 *
 * DESCRIPTION: Computes an 8 bit checksum of the buffer(length) and returns it.
 *
 ******************************************************************************/

u8 acpi_tb_generate_checksum(void *buffer, u32 length)
{
	const u8 *limit;
	const u8 *rover;
	u8 sum = 0;

	if (buffer && length) {
		/*  Buffer and Length are valid   */

		limit = (u8 *) buffer + length;

		for (rover = buffer; rover < limit; rover++) {
			sum = (u8) (sum + *rover);
		}
	}
	return (sum);
}

#ifdef ACPI_OBSOLETE_FUNCTIONS
/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_handle_to_object
 *
 * PARAMETERS:  table_id            - Id for which the function is searching
 *              table_desc          - Pointer to return the matching table
 *                                      descriptor.
 *
 * RETURN:      Search the tables to find one with a matching table_id and
 *              return a pointer to that table descriptor.
 *
 ******************************************************************************/

acpi_status
acpi_tb_handle_to_object(u16 table_id,
			 struct acpi_table_desc ** return_table_desc)
{
	u32 i;
	struct acpi_table_desc *table_desc;

	ACPI_FUNCTION_NAME("tb_handle_to_object");

	for (i = 0; i < ACPI_TABLE_MAX; i++) {
		table_desc = acpi_gbl_table_lists[i].next;
		while (table_desc) {
			if (table_desc->table_id == table_id) {
				*return_table_desc = table_desc;
				return (AE_OK);
			}

			table_desc = table_desc->next;
		}
	}

	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "table_id=%X does not exist\n",
			  table_id));
	return (AE_BAD_PARAMETER);
}
#endif
Commit	Line	Data
1da177e4 LT	1	/******************************************************************************
	2	*
	3	* Module Name: tbutils - Table manipulation utilities
	4	*
	5	*****************************************************************************/
	6
	7	/*
	8	* Copyright (C) 2000 - 2005, R. Byron Moore
	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
1da177e4 LT	44	#include <acpi/acpi.h>
	45	#include <acpi/actables.h>
	46
1da177e4	47	#define _COMPONENT ACPI_TABLES
4be44fcd	48	ACPI_MODULE_NAME("tbutils")
1da177e4	49
44f6c012	50	/* Local prototypes */
44f6c012	51	#ifdef ACPI_OBSOLETE_FUNCTIONS
1da177e4	52	acpi_status
4be44fcd	53	acpi_tb_handle_to_object(u16 table_id, struct acpi_table_desc **table_desc);
44f6c012	54	#endif
1da177e4	55
0c9938cc RM	56	/*******************************************************************************
	57	*
	58	* FUNCTION: acpi_tb_is_table_installed
	59	*
	60	* PARAMETERS: new_table_desc - Descriptor for new table being installed
	61	*
	62	* RETURN: Status - AE_ALREADY_EXISTS if the table is already installed
	63	*
	64	* DESCRIPTION: Determine if an ACPI table is already installed
	65	*
	66	* MUTEX: Table data structures should be locked
	67	*
	68	******************************************************************************/
	69
4be44fcd	70	acpi_status acpi_tb_is_table_installed(struct acpi_table_desc *new_table_desc)
0c9938cc	71	{
4be44fcd	72	struct acpi_table_desc *table_desc;
0c9938cc	73
4be44fcd	74	ACPI_FUNCTION_TRACE("tb_is_table_installed");
0c9938cc RM	75
	76	/* Get the list descriptor and first table descriptor */
	77
	78	table_desc = acpi_gbl_table_lists[new_table_desc->type].next;
	79
	80	/* Examine all installed tables of this type */
	81
	82	while (table_desc) {
a18ecf41 BM	83	/*
	84	* If the table lengths match, perform a full bytewise compare. This
	85	* means that we will allow tables with duplicate oem_table_id(s), as
	86	* long as the tables are different in some way.
	87	*
	88	* Checking if the table has been loaded into the namespace means that
	89	* we don't check for duplicate tables during the initial installation
	90	* of tables within the RSDT/XSDT.
	91	*/
0c9938cc	92	if ((table_desc->loaded_into_namespace) &&
a18ecf41 BM	93	(table_desc->pointer->length ==
	94	new_table_desc->pointer->length)
	95	&&
	96	(!ACPI_MEMCMP
	97	((const char *)table_desc->pointer,
	98	(const char *)new_table_desc->pointer,
	99	(acpi_size) new_table_desc->pointer->length))) {
	100	/* Match: this table is already installed */
0c9938cc	101
4be44fcd LB	102	ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
	103	"Table [%4.4s] already installed: Rev %X oem_table_id [%8.8s]\n",
	104	new_table_desc->pointer->signature,
	105	new_table_desc->pointer->revision,
	106	new_table_desc->pointer->
	107	oem_table_id));
0c9938cc	108
4be44fcd	109	new_table_desc->owner_id = table_desc->owner_id;
0c9938cc RM	110	new_table_desc->installed_desc = table_desc;
0c9938cc RM	111
4be44fcd	112	return_ACPI_STATUS(AE_ALREADY_EXISTS);
0c9938cc RM	113	}
	114
	115	/* Get next table on the list */
	116
	117	table_desc = table_desc->next;
	118	}
	119
4be44fcd	120	return_ACPI_STATUS(AE_OK);
0c9938cc RM	121	}
0c9938cc RM	122
1da177e4 LT	123	/*******************************************************************************
	124	*
	125	* FUNCTION: acpi_tb_validate_table_header
	126	*
	127	* PARAMETERS: table_header - Logical pointer to the table
	128	*
	129	* RETURN: Status
	130	*
	131	* DESCRIPTION: Check an ACPI table header for validity
	132	*
	133	* NOTE: Table pointers are validated as follows:
	134	* 1) Table pointer must point to valid physical memory
	135	* 2) Signature must be 4 ASCII chars, even if we don't recognize the
	136	* name
	137	* 3) Table must be readable for length specified in the header
	138	* 4) Table checksum must be valid (with the exception of the FACS
	139	* which has no checksum because it contains variable fields)
	140	*
	141	******************************************************************************/
	142
	143	acpi_status
4be44fcd	144	acpi_tb_validate_table_header(struct acpi_table_header *table_header)
1da177e4	145	{
4be44fcd	146	acpi_name signature;
1da177e4	147
4be44fcd	148	ACPI_FUNCTION_NAME("tb_validate_table_header");
1da177e4 LT	149
	150	/* Verify that this is a valid address */
	151
4be44fcd LB	152	if (!acpi_os_readable(table_header, sizeof(struct acpi_table_header))) {
	153	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	154	"Cannot read table header at %p\n",
	155	table_header));
44f6c012	156
1da177e4 LT	157	return (AE_BAD_ADDRESS);
	158	}
	159
	160	/* Ensure that the signature is 4 ASCII characters */
	161
4be44fcd LB	162	ACPI_MOVE_32_TO_32(&signature, table_header->signature);
	163	if (!acpi_ut_valid_acpi_name(signature)) {
	164	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	165	"Table signature at %p [%p] has invalid characters\n",
	166	table_header, &signature));
1da177e4	167
4be44fcd LB	168	ACPI_REPORT_WARNING(("Invalid table signature found: [%4.4s]\n",
4be44fcd LB	169	(char *)&signature));
44f6c012	170
4be44fcd LB	171	ACPI_DUMP_BUFFER(table_header,
4be44fcd LB	172	sizeof(struct acpi_table_header));
1da177e4 LT	173	return (AE_BAD_SIGNATURE);
	174	}
	175
	176	/* Validate the table length */
	177
4be44fcd LB	178	if (table_header->length < sizeof(struct acpi_table_header)) {
	179	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	180	"Invalid length in table header %p name %4.4s\n",
	181	table_header, (char *)&signature));
1da177e4	182
4be44fcd	183	ACPI_REPORT_WARNING(("Invalid table header length (0x%X) found\n", (u32) table_header->length));
44f6c012	184
4be44fcd LB	185	ACPI_DUMP_BUFFER(table_header,
4be44fcd LB	186	sizeof(struct acpi_table_header));
1da177e4 LT	187	return (AE_BAD_HEADER);
	188	}
	189
	190	return (AE_OK);
	191	}
	192
1da177e4 LT	193	/*******************************************************************************
	194	*
	195	* FUNCTION: acpi_tb_verify_table_checksum
	196	*
	197	* PARAMETERS: *table_header - ACPI table to verify
	198	*
	199	* RETURN: 8 bit checksum of table
	200	*
	201	* DESCRIPTION: Does an 8 bit checksum of table and returns status. A correct
	202	* table should have a checksum of 0.
	203	*
	204	******************************************************************************/
	205
	206	acpi_status
4be44fcd	207	acpi_tb_verify_table_checksum(struct acpi_table_header * table_header)
1da177e4	208	{
4be44fcd LB	209	u8 checksum;
4be44fcd LB	210	acpi_status status = AE_OK;
1da177e4	211
4be44fcd	212	ACPI_FUNCTION_TRACE("tb_verify_table_checksum");
1da177e4 LT	213
	214	/* Compute the checksum on the table */
	215
4be44fcd LB	216	checksum =
4be44fcd LB	217	acpi_tb_generate_checksum(table_header, table_header->length);
1da177e4 LT	218
	219	/* Return the appropriate exception */
	220
	221	if (checksum) {
4be44fcd	222	ACPI_REPORT_WARNING(("Invalid checksum in table [%4.4s] (%02X, sum %02X is not zero)\n", table_header->signature, (u32) table_header->checksum, (u32) checksum));
1da177e4 LT	223
	224	status = AE_BAD_CHECKSUM;
	225	}
4be44fcd	226	return_ACPI_STATUS(status);
1da177e4 LT	227	}
1da177e4 LT	228
1da177e4 LT	229	/*******************************************************************************
1da177e4 LT	230	*
0c9938cc	231	* FUNCTION: acpi_tb_generate_checksum
1da177e4 LT	232	*
	233	* PARAMETERS: Buffer - Buffer to checksum
	234	* Length - Size of the buffer
	235	*
44f6c012	236	* RETURN: 8 bit checksum of buffer
1da177e4 LT	237	*
	238	* DESCRIPTION: Computes an 8 bit checksum of the buffer(length) and returns it.
	239	*
	240	******************************************************************************/
	241
4be44fcd	242	u8 acpi_tb_generate_checksum(void *buffer, u32 length)
1da177e4	243	{
4be44fcd LB	244	const u8 *limit;
	245	const u8 *rover;
	246	u8 sum = 0;
1da177e4 LT	247
	248	if (buffer && length) {
	249	/* Buffer and Length are valid */
	250
	251	limit = (u8 *) buffer + length;
	252
	253	for (rover = buffer; rover < limit; rover++) {
	254	sum = (u8) (sum + *rover);
	255	}
	256	}
	257	return (sum);
	258	}
	259
44f6c012 RM	260	#ifdef ACPI_OBSOLETE_FUNCTIONS
	261	/*******************************************************************************
	262	*
	263	* FUNCTION: acpi_tb_handle_to_object
	264	*
	265	* PARAMETERS: table_id - Id for which the function is searching
	266	* table_desc - Pointer to return the matching table
	267	* descriptor.
	268	*
	269	* RETURN: Search the tables to find one with a matching table_id and
	270	* return a pointer to that table descriptor.
	271	*
	272	******************************************************************************/
	273
	274	acpi_status
4be44fcd LB	275	acpi_tb_handle_to_object(u16 table_id,
4be44fcd LB	276	struct acpi_table_desc ** return_table_desc)
44f6c012	277	{
4be44fcd LB	278	u32 i;
4be44fcd LB	279	struct acpi_table_desc *table_desc;
44f6c012	280
4be44fcd	281	ACPI_FUNCTION_NAME("tb_handle_to_object");
44f6c012 RM	282
	283	for (i = 0; i < ACPI_TABLE_MAX; i++) {
	284	table_desc = acpi_gbl_table_lists[i].next;
	285	while (table_desc) {
	286	if (table_desc->table_id == table_id) {
	287	*return_table_desc = table_desc;
	288	return (AE_OK);
	289	}
	290
	291	table_desc = table_desc->next;
	292	}
	293	}
	294
4be44fcd LB	295	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "table_id=%X does not exist\n",
4be44fcd LB	296	table_id));
44f6c012 RM	297	return (AE_BAD_PARAMETER);
	298	}
	299	#endif