tbxfroot.c

linux-2.6.15.6

		if (ACPI_FAILURE(status)) {
			goto cleanup;
		}

		/* Compare table signatures and table instance */

		if (!ACPI_STRNCMP(header->signature, signature, ACPI_NAME_SIZE)) {
			/* An instance of the table was found */

			j++;
			if (j >= instance) {
				/* Found the correct instance, get the entire table */

				status =
				    acpi_tb_get_table_body(&address, header,
							   table_info);
				if (ACPI_FAILURE(status)) {
					goto cleanup;
				}

				*table_pointer = table_info->pointer;
				goto cleanup;
			}
		}
	}

	/* Did not find the table */

	status = AE_NOT_EXIST;

      cleanup:
	if (rsdt_info->pointer) {
		acpi_os_unmap_memory(rsdt_info->pointer,
				     (acpi_size) rsdt_info->pointer->length);
	}
	ACPI_MEM_FREE(rsdt_info);

	if (header) {
		ACPI_MEM_FREE(header);
	}
	if (table_info) {
		ACPI_MEM_FREE(table_info);
	}
	return_ACPI_STATUS(status);
}

EXPORT_SYMBOL(acpi_get_firmware_table);

/* TBD: Move to a new file */

#if ACPI_MACHINE_WIDTH != 16

/*******************************************************************************
 *
 * FUNCTION:    acpi_find_root_pointer
 *
 * PARAMETERS:  Flags                   - Logical/Physical addressing
 *              rsdp_address            - Where to place the RSDP address
 *
 * RETURN:      Status, Physical address of the RSDP
 *
 * DESCRIPTION: Find the RSDP
 *
 ******************************************************************************/

acpi_status acpi_find_root_pointer(u32 flags, struct acpi_pointer *rsdp_address)
{
	struct acpi_table_desc table_info;
	acpi_status status;

	ACPI_FUNCTION_TRACE("acpi_find_root_pointer");

	/* Get the RSDP */

	status = acpi_tb_find_rsdp(&table_info, flags);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "RSDP structure not found, %s Flags=%X\n",
				  acpi_format_exception(status), flags));

		return_ACPI_STATUS(AE_NO_ACPI_TABLES);
	}

	rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
	rsdp_address->pointer.physical = table_info.physical_address;
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_scan_memory_for_rsdp
 *
 * PARAMETERS:  start_address       - Starting pointer for search
 *              Length              - Maximum length to search
 *
 * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 *
 * DESCRIPTION: Search a block of memory for the RSDP signature
 *
 ******************************************************************************/

static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
{
	acpi_status status;
	u8 *mem_rover;
	u8 *end_address;

	ACPI_FUNCTION_TRACE("tb_scan_memory_for_rsdp");

	end_address = start_address + length;

	/* Search from given start address for the requested length */

	for (mem_rover = start_address; mem_rover < end_address;
	     mem_rover += ACPI_RSDP_SCAN_STEP) {
		/* The RSDP signature and checksum must both be correct */

		status =
		    acpi_tb_validate_rsdp(ACPI_CAST_PTR
					  (struct rsdp_descriptor, mem_rover));
		if (ACPI_SUCCESS(status)) {
			/* Sig and checksum valid, we have found a real RSDP */

			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "RSDP located at physical address %p\n",
					  mem_rover));
			return_PTR(mem_rover);
		}

		/* No sig match or bad checksum, keep searching */
	}

	/* Searched entire block, no RSDP was found */

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Searched entire block from %p, valid RSDP was not found\n",
			  start_address));
	return_PTR(NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_rsdp
 *
 * PARAMETERS:  table_info              - Where the table info is returned
 *              Flags                   - Current memory mode (logical vs.
 *                                        physical addressing)
 *
 * RETURN:      Status, RSDP physical address
 *
 * DESCRIPTION: search lower 1_mbyte of memory for the root system descriptor
 *              pointer structure.  If it is found, set *RSDP to point to it.
 *
 *              NOTE1: The RSDp must be either in the first 1_k of the Extended
 *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 *              Only a 32-bit physical address is necessary.
 *
 *              NOTE2: This function is always available, regardless of the
 *              initialization state of the rest of ACPI.
 *
 ******************************************************************************/

static acpi_status
acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags)
{
	u8 *table_ptr;
	u8 *mem_rover;
	u32 physical_address;
	acpi_status status;

	ACPI_FUNCTION_TRACE("tb_find_rsdp");

	/*
	 * Scan supports either logical addressing or physical addressing
	 */
	if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
		/* 1a) Get the location of the Extended BIOS Data Area (EBDA) */

		status = acpi_os_map_memory((acpi_physical_address)
					    ACPI_EBDA_PTR_LOCATION,
					    ACPI_EBDA_PTR_LENGTH,
					    (void *)&table_ptr);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Could not map memory at %8.8X for length %X\n",
					  ACPI_EBDA_PTR_LOCATION,
					  ACPI_EBDA_PTR_LENGTH));

			return_ACPI_STATUS(status);
		}

		ACPI_MOVE_16_TO_32(&physical_address, table_ptr);

		/* Convert segment part to physical address */

		physical_address <<= 4;
		acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);

		/* EBDA present? */

		if (physical_address > 0x400) {
			/*
			 * 1b) Search EBDA paragraphs (EBDa is required to be a
			 *     minimum of 1_k length)
			 */
			status = acpi_os_map_memory((acpi_physical_address)
						    physical_address,
						    ACPI_EBDA_WINDOW_SIZE,
						    (void *)&table_ptr);
			if (ACPI_FAILURE(status)) {
				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
						  "Could not map memory at %8.8X for length %X\n",
						  physical_address,
						  ACPI_EBDA_WINDOW_SIZE));

				return_ACPI_STATUS(status);
			}

			mem_rover = acpi_tb_scan_memory_for_rsdp(table_ptr,
								 ACPI_EBDA_WINDOW_SIZE);
			acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);

			if (mem_rover) {
				/* Return the physical address */

				physical_address +=
				    ACPI_PTR_DIFF(mem_rover, table_ptr);

				table_info->physical_address =
				    (acpi_physical_address) physical_address;
				return_ACPI_STATUS(AE_OK);
			}
		}

		/*
		 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
		 */
		status = acpi_os_map_memory((acpi_physical_address)
					    ACPI_HI_RSDP_WINDOW_BASE,
					    ACPI_HI_RSDP_WINDOW_SIZE,
					    (void *)&table_ptr);

		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Could not map memory at %8.8X for length %X\n",
					  ACPI_HI_RSDP_WINDOW_BASE,
					  ACPI_HI_RSDP_WINDOW_SIZE));

			return_ACPI_STATUS(status);
		}

		mem_rover =
		    acpi_tb_scan_memory_for_rsdp(table_ptr,
						 ACPI_HI_RSDP_WINDOW_SIZE);
		acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);

		if (mem_rover) {
			/* Return the physical address */

			physical_address =
			    ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF(mem_rover,
								     table_ptr);

			table_info->physical_address =
			    (acpi_physical_address) physical_address;
			return_ACPI_STATUS(AE_OK);
		}
	}

	/*
	 * Physical addressing
	 */
	else {
		/* 1a) Get the location of the EBDA */

		ACPI_MOVE_16_TO_32(&physical_address, ACPI_EBDA_PTR_LOCATION);
		physical_address <<= 4;	/* Convert segment to physical address */

		/* EBDA present? */

		if (physical_address > 0x400) {
			/*
			 * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of
			 *     1_k length)
			 */
			mem_rover =
			    acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
							 (physical_address),
							 ACPI_EBDA_WINDOW_SIZE);
			if (mem_rover) {
				/* Return the physical address */

				table_info->physical_address =
				    ACPI_TO_INTEGER(mem_rover);
				return_ACPI_STATUS(AE_OK);
			}
		}

		/* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */

		mem_rover =
		    acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
						 (ACPI_HI_RSDP_WINDOW_BASE),
						 ACPI_HI_RSDP_WINDOW_SIZE);
		if (mem_rover) {
			/* Found it, return the physical address */

			table_info->physical_address =
			    ACPI_TO_INTEGER(mem_rover);
			return_ACPI_STATUS(AE_OK);
		}
	}

	/* A valid RSDP was not found */

	ACPI_REPORT_ERROR(("No valid RSDP was found\n"));
	return_ACPI_STATUS(AE_NOT_FOUND);
}

#endif