exfldio.c

linux-2.6.15.6

/******************************************************************************
 *
 * Module Name: exfldio - Aml Field I/O
 *
 *****************************************************************************/

/*
 * 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/acinterp.h>
#include <acpi/amlcode.h>
#include <acpi/acevents.h>
#include <acpi/acdispat.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exfldio")

/* Local prototypes */
static acpi_status
acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
		       u32 field_datum_byte_offset,
		       acpi_integer * value, u32 read_write);

static u8
acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
			  acpi_integer value);

static acpi_status
acpi_ex_setup_region(union acpi_operand_object *obj_desc,
		     u32 field_datum_byte_offset);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_setup_region
 *
 * PARAMETERS:  obj_desc                - Field to be read or written
 *              field_datum_byte_offset - Byte offset of this datum within the
 *                                        parent field
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
 *              acpi_ex_insert_into_field. Initialize the Region if necessary and
 *              validate the request.
 *
 ******************************************************************************/

static acpi_status
acpi_ex_setup_region(union acpi_operand_object *obj_desc,
		     u32 field_datum_byte_offset)
{
	acpi_status status = AE_OK;
	union acpi_operand_object *rgn_desc;

	ACPI_FUNCTION_TRACE_U32("ex_setup_region", field_datum_byte_offset);

	rgn_desc = obj_desc->common_field.region_obj;

	/* We must have a valid region */

	if (ACPI_GET_OBJECT_TYPE(rgn_desc) != ACPI_TYPE_REGION) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Needed Region, found type %X (%s)\n",
				  ACPI_GET_OBJECT_TYPE(rgn_desc),
				  acpi_ut_get_object_type_name(rgn_desc)));

		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
	}

	/*
	 * If the Region Address and Length have not been previously evaluated,
	 * evaluate them now and save the results.
	 */
	if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
		status = acpi_ds_get_region_arguments(rgn_desc);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
		/* SMBus has a non-linear address space */

		return_ACPI_STATUS(AE_OK);
	}
#ifdef ACPI_UNDER_DEVELOPMENT
	/*
	 * If the Field access is any_acc, we can now compute the optimal
	 * access (because we know know the length of the parent region)
	 */
	if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}
#endif

	/*
	 * Validate the request.  The entire request from the byte offset for a
	 * length of one field datum (access width) must fit within the region.
	 * (Region length is specified in bytes)
	 */
	if (rgn_desc->region.length < (obj_desc->common_field.base_byte_offset +
				       field_datum_byte_offset +
				       obj_desc->common_field.
				       access_byte_width)) {
		if (acpi_gbl_enable_interpreter_slack) {
			/*
			 * Slack mode only:  We will go ahead and allow access to this
			 * field if it is within the region length rounded up to the next
			 * access width boundary.
			 */
			if (ACPI_ROUND_UP(rgn_desc->region.length,
					  obj_desc->common_field.
					  access_byte_width) >=
			    (obj_desc->common_field.base_byte_offset +
			     (acpi_native_uint) obj_desc->common_field.
			     access_byte_width + field_datum_byte_offset)) {
				return_ACPI_STATUS(AE_OK);
			}
		}

		if (rgn_desc->region.length <
		    obj_desc->common_field.access_byte_width) {
			/*
			 * This is the case where the access_type (acc_word, etc.) is wider
			 * than the region itself.  For example, a region of length one
			 * byte, and a field with Dword access specified.
			 */
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)\n",
					  acpi_ut_get_node_name(obj_desc->
								common_field.
								node),
					  obj_desc->common_field.
					  access_byte_width,
					  acpi_ut_get_node_name(rgn_desc->
								region.node),
					  rgn_desc->region.length));
		}

		/*
		 * Offset rounded up to next multiple of field width
		 * exceeds region length, indicate an error
		 */
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)\n",
				  acpi_ut_get_node_name(obj_desc->common_field.
							node),
				  obj_desc->common_field.base_byte_offset,
				  field_datum_byte_offset,
				  obj_desc->common_field.access_byte_width,
				  acpi_ut_get_node_name(rgn_desc->region.node),
				  rgn_desc->region.length));

		return_ACPI_STATUS(AE_AML_REGION_LIMIT);
	}

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_access_region
 *
 * PARAMETERS:  obj_desc                - Field to be read
 *              field_datum_byte_offset - Byte offset of this datum within the
 *                                        parent field
 *              Value                   - Where to store value (must at least
 *                                        the size of acpi_integer)
 *              Function                - Read or Write flag plus other region-
 *                                        dependent flags
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
 *
 ******************************************************************************/

acpi_status
acpi_ex_access_region(union acpi_operand_object *obj_desc,
		      u32 field_datum_byte_offset,
		      acpi_integer * value, u32 function)
{
	acpi_status status;
	union acpi_operand_object *rgn_desc;
	acpi_physical_address address;

	ACPI_FUNCTION_TRACE("ex_access_region");

	/*
	 * Ensure that the region operands are fully evaluated and verify
	 * the validity of the request
	 */
	status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/*
	 * The physical address of this field datum is:
	 *
	 * 1) The base of the region, plus
	 * 2) The base offset of the field, plus
	 * 3) The current offset into the field
	 */
	rgn_desc = obj_desc->common_field.region_obj;
	address = rgn_desc->region.address +
	    obj_desc->common_field.base_byte_offset + field_datum_byte_offset;

	if ((function & ACPI_IO_MASK) == ACPI_READ) {
		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
	} else {
		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
	}

	ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
			      " Region [%s:%X], Width %X, byte_base %X, Offset %X at %8.8X%8.8X\n",
			      acpi_ut_get_region_name(rgn_desc->region.
						      space_id),
			      rgn_desc->region.space_id,
			      obj_desc->common_field.access_byte_width,
			      obj_desc->common_field.base_byte_offset,
			      field_datum_byte_offset,
			      ACPI_FORMAT_UINT64(address)));

	/* Invoke the appropriate address_space/op_region handler */

	status = acpi_ev_address_space_dispatch(rgn_desc, function,
						address,
						ACPI_MUL_8(obj_desc->
							   common_field.
							   access_byte_width),
						value);

	if (ACPI_FAILURE(status)) {
		if (status == AE_NOT_IMPLEMENTED) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Region %s(%X) not implemented\n",
					  acpi_ut_get_region_name(rgn_desc->
								  region.
								  space_id),
					  rgn_desc->region.space_id));
		} else if (status == AE_NOT_EXIST) {
			ACPI_REPORT_ERROR(("Region %s(%X) has no handler\n",
					   acpi_ut_get_region_name(rgn_desc->
								   region.
								   space_id),
					   rgn_desc->region.space_id));
		}
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_register_overflow
 *
 * PARAMETERS:  obj_desc                - Register(Field) to be written
 *              Value                   - Value to be stored
 *
 * RETURN:      TRUE if value overflows the field, FALSE otherwise
 *
 * DESCRIPTION: Check if a value is out of range of the field being written.
 *              Used to check if the values written to Index and Bank registers
 *              are out of range.  Normally, the value is simply truncated
 *              to fit the field, but this case is most likely a serious
 *              coding error in the ASL.
 *
 ******************************************************************************/

static u8
acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
			  acpi_integer value)
{

	if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
		/*
		 * The field is large enough to hold the maximum integer, so we can
		 * never overflow it.
		 */
		return (FALSE);
	}

	if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
		/*
		 * The Value is larger than the maximum value that can fit into
		 * the register.
		 */
		return (TRUE);
	}

	/* The Value will fit into the field with no truncation */

	return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_field_datum_io
 *
 * PARAMETERS:  obj_desc                - Field to be read
 *              field_datum_byte_offset - Byte offset of this datum within the
 *                                        parent field
 *              Value                   - Where to store value (must be 64 bits)
 *              read_write              - Read or Write flag
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read or Write a single datum of a field.  The field_type is
 *              demultiplexed here to handle the different types of fields
 *              (buffer_field, region_field, index_field, bank_field)
 *
 ******************************************************************************/

static acpi_status
acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
		       u32 field_datum_byte_offset,
		       acpi_integer * value, u32 read_write)
{
	acpi_status status;
	acpi_integer local_value;

	ACPI_FUNCTION_TRACE_U32("ex_field_datum_io", field_datum_byte_offset);

	if (read_write == ACPI_READ) {
		if (!value) {
			local_value = 0;

			/* To support reads without saving return value */
			value = &local_value;
		}

		/* Clear the entire return buffer first, [Very Important!] */

		*value = 0;
	}

	/*
	 * The four types of fields are:
	 *
	 * buffer_field - Read/write from/to a Buffer
	 * region_field - Read/write from/to a Operation Region.
	 * bank_field  - Write to a Bank Register, then read/write from/to an
	 *               operation_region
	 * index_field - Write to an Index Register, then read/write from/to a
	 *               Data Register
	 */
	switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
	case ACPI_TYPE_BUFFER_FIELD:
		/*
		 * If the buffer_field arguments have not been previously evaluated,
		 * evaluate them now and save the results.
		 */
		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
			status = acpi_ds_get_buffer_field_arguments(obj_desc);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}
		}

		if (read_write == ACPI_READ) {
			/*
			 * Copy the data from the source buffer.
			 * Length is the field width in bytes.
			 */
			ACPI_MEMCPY(value,
				    (obj_desc->buffer_field.buffer_obj)->buffer.
				    pointer +
				    obj_desc->buffer_field.base_byte_offset +
				    field_datum_byte_offset,
				    obj_desc->common_field.access_byte_width);
		} else {
			/*
			 * Copy the data to the target buffer.
			 * Length is the field width in bytes.
			 */
			ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
				    pointer +
				    obj_desc->buffer_field.base_byte_offset +
				    field_datum_byte_offset, value,
				    obj_desc->common_field.access_byte_width);
		}

		status = AE_OK;
		break;

	case ACPI_TYPE_LOCAL_BANK_FIELD:

		/*
		 * Ensure that the bank_value is not beyond the capacity of
		 * the register
		 */
		if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
					      (acpi_integer) obj_desc->
					      bank_field.value)) {
			return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
		}

		/*
		 * For bank_fields, we must write the bank_value to the bank_register
		 * (itself a region_field) before we can access the data.
		 */