exfldio.c

h内核

		 */
		status = acpi_ex_insert_into_field (obj_desc->bank_field.bank_obj,
				 &obj_desc->bank_field.value,
				 sizeof (obj_desc->bank_field.value));
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}

		/*
		 * Now that the Bank has been selected, fall through to the
		 * region_field case and write the datum to the Operation Region
		 */

		/*lint -fallthrough */


	case ACPI_TYPE_LOCAL_REGION_FIELD:
		/*
		 * For simple region_fields, we just directly access the owning
		 * Operation Region.
		 */
		status = acpi_ex_access_region (obj_desc, field_datum_byte_offset, value,
				  read_write);
		break;


	case ACPI_TYPE_LOCAL_INDEX_FIELD:


		/* Ensure that the index_value is not beyond the capacity of the register */

		if (acpi_ex_register_overflow (obj_desc->index_field.index_obj,
				  (acpi_integer) obj_desc->index_field.value)) {
			return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
		}

		/* Write the index value to the index_register (itself a region_field) */

		field_datum_byte_offset += obj_desc->index_field.value;

		ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
				"Write to Index Register: Value %8.8X\n",
				field_datum_byte_offset));

		status = acpi_ex_insert_into_field (obj_desc->index_field.index_obj,
				 &field_datum_byte_offset,
				 sizeof (field_datum_byte_offset));
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}

		ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
				"I/O to Data Register: value_ptr %p\n",
				value));

		if (read_write == ACPI_READ) {
			/* Read the datum from the data_register */

			status = acpi_ex_extract_from_field (obj_desc->index_field.data_obj,
					  value, sizeof (acpi_integer));
		}
		else {
			/* Write the datum to the data_register */

			status = acpi_ex_insert_into_field (obj_desc->index_field.data_obj,
					  value, sizeof (acpi_integer));
		}
		break;


	default:

		ACPI_REPORT_ERROR (("Wrong object type in field I/O %X\n",
			ACPI_GET_OBJECT_TYPE (obj_desc)));
		status = AE_AML_INTERNAL;
		break;
	}

	if (ACPI_SUCCESS (status)) {
		if (read_write == ACPI_READ) {
			ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Value Read %8.8X%8.8X, Width %d\n",
					   ACPI_FORMAT_UINT64 (*value),
					   obj_desc->common_field.access_byte_width));
		}
		else {
			ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Value Written %8.8X%8.8X, Width %d\n",
					   ACPI_FORMAT_UINT64 (*value),
					   obj_desc->common_field.access_byte_width));
		}
	}

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_write_with_update_rule
 *
 * PARAMETERS:  *obj_desc           - Field to be set
 *              Value               - Value to store
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Apply the field update rule to a field write
 *
 ******************************************************************************/

acpi_status
acpi_ex_write_with_update_rule (
	union acpi_operand_object       *obj_desc,
	acpi_integer                    mask,
	acpi_integer                    field_value,
	u32                             field_datum_byte_offset)
{
	acpi_status                     status = AE_OK;
	acpi_integer                    merged_value;
	acpi_integer                    current_value;


	ACPI_FUNCTION_TRACE_U32 ("ex_write_with_update_rule", mask);


	/* Start with the new bits  */

	merged_value = field_value;

	/* If the mask is all ones, we don't need to worry about the update rule */

	if (mask != ACPI_INTEGER_MAX) {
		/* Decode the update rule */

		switch (obj_desc->common_field.field_flags & AML_FIELD_UPDATE_RULE_MASK) {
		case AML_FIELD_UPDATE_PRESERVE:
			/*
			 * Check if update rule needs to be applied (not if mask is all
			 * ones)  The left shift drops the bits we want to ignore.
			 */
			if ((~mask << (ACPI_MUL_8 (sizeof (mask)) -
					 ACPI_MUL_8 (obj_desc->common_field.access_byte_width))) != 0) {
				/*
				 * Read the current contents of the byte/word/dword containing
				 * the field, and merge with the new field value.
				 */
				status = acpi_ex_field_datum_io (obj_desc, field_datum_byte_offset,
						  &current_value, ACPI_READ);
				if (ACPI_FAILURE (status)) {
					return_ACPI_STATUS (status);
				}

				merged_value |= (current_value & ~mask);
			}
			break;

		case AML_FIELD_UPDATE_WRITE_AS_ONES:

			/* Set positions outside the field to all ones */

			merged_value |= ~mask;
			break;

		case AML_FIELD_UPDATE_WRITE_AS_ZEROS:

			/* Set positions outside the field to all zeros */

			merged_value &= mask;
			break;

		default:

			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
				"write_with_update_rule: Unknown update_rule setting: %X\n",
				(obj_desc->common_field.field_flags & AML_FIELD_UPDATE_RULE_MASK)));
			return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
		}
	}

	ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
		"Mask %8.8X%8.8X, datum_offset %X, Width %X, Value %8.8X%8.8X, merged_value %8.8X%8.8X\n",
		ACPI_FORMAT_UINT64 (mask),
		field_datum_byte_offset,
		obj_desc->common_field.access_byte_width,
		ACPI_FORMAT_UINT64 (field_value),
		ACPI_FORMAT_UINT64 (merged_value)));

	/* Write the merged value */

	status = acpi_ex_field_datum_io (obj_desc, field_datum_byte_offset,
			  &merged_value, ACPI_WRITE);

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_extract_from_field
 *
 * PARAMETERS:  obj_desc            - Field to be read
 *              Buffer              - Where to store the field data
 *              buffer_length       - Length of Buffer
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Retrieve the current value of the given field
 *
 ******************************************************************************/

acpi_status
acpi_ex_extract_from_field (
	union acpi_operand_object       *obj_desc,
	void                            *buffer,
	u32                             buffer_length)
{
	acpi_status                     status;
	acpi_integer                    raw_datum;
	acpi_integer                    merged_datum;
	u32                             field_offset = 0;
	u32                             buffer_offset = 0;
	u32                             buffer_tail_bits;
	u32                             datum_count;
	u32                             field_datum_count;
	u32                             i;


	ACPI_FUNCTION_TRACE ("ex_extract_from_field");


	/* Validate target buffer and clear it */

	if (buffer_length < ACPI_ROUND_BITS_UP_TO_BYTES (
			 obj_desc->common_field.bit_length)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
			"Field size %X (bits) is too large for buffer (%X)\n",
			obj_desc->common_field.bit_length, buffer_length));

		return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
	}
	ACPI_MEMSET (buffer, 0, buffer_length);

	/* Compute the number of datums (access width data items) */

	datum_count = ACPI_ROUND_UP_TO (
			   obj_desc->common_field.bit_length,
			   obj_desc->common_field.access_bit_width);
	field_datum_count = ACPI_ROUND_UP_TO (
			   obj_desc->common_field.bit_length +
			   obj_desc->common_field.start_field_bit_offset,
			   obj_desc->common_field.access_bit_width);

	/* Priming read from the field */

	status = acpi_ex_field_datum_io (obj_desc, field_offset, &raw_datum, ACPI_READ);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}
	merged_datum = raw_datum >> obj_desc->common_field.start_field_bit_offset;

	/* Read the rest of the field */

	for (i = 1; i < field_datum_count; i++) {
		/* Get next input datum from the field */

		field_offset += obj_desc->common_field.access_byte_width;
		status = acpi_ex_field_datum_io (obj_desc, field_offset,
				  &raw_datum, ACPI_READ);
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}

		/* Merge with previous datum if necessary */

		merged_datum |= raw_datum <<
			(obj_desc->common_field.access_bit_width - obj_desc->common_field.start_field_bit_offset);

		if (i == datum_count) {
			break;
		}

		/* Write merged datum to target buffer */

		ACPI_MEMCPY (((char *) buffer) + buffer_offset, &merged_datum,
			ACPI_MIN(obj_desc->common_field.access_byte_width,
					 buffer_length - buffer_offset));

		buffer_offset += obj_desc->common_field.access_byte_width;
		merged_datum = raw_datum >> obj_desc->common_field.start_field_bit_offset;
	}

	/* Mask off any extra bits in the last datum */

	buffer_tail_bits = obj_desc->common_field.bit_length % obj_desc->common_field.access_bit_width;
	if (buffer_tail_bits) {
		merged_datum &= ACPI_MASK_BITS_ABOVE (buffer_tail_bits);
	}

	/* Write the last datum to the buffer */

	ACPI_MEMCPY (((char *) buffer) + buffer_offset, &merged_datum,
		ACPI_MIN(obj_desc->common_field.access_byte_width,
				 buffer_length - buffer_offset));

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_insert_into_field
 *
 * PARAMETERS:  obj_desc            - Field to be written
 *              Buffer              - Data to be written
 *              buffer_length       - Length of Buffer
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Store the Buffer contents into the given field
 *
 ******************************************************************************/

acpi_status
acpi_ex_insert_into_field (
	union acpi_operand_object       *obj_desc,
	void                            *buffer,
	u32                             buffer_length)
{
	acpi_status                     status;
	acpi_integer                    mask;
	acpi_integer                    merged_datum;
	acpi_integer                    raw_datum = 0;
	u32                             field_offset = 0;
	u32                             buffer_offset = 0;
	u32                             buffer_tail_bits;
	u32                             datum_count;
	u32                             field_datum_count;
	u32                             i;


	ACPI_FUNCTION_TRACE ("ex_insert_into_field");


	/* Validate input buffer */

	if (buffer_length < ACPI_ROUND_BITS_UP_TO_BYTES (
			 obj_desc->common_field.bit_length)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
			"Field size %X (bits) is too large for buffer (%X)\n",
			obj_desc->common_field.bit_length, buffer_length));

		return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
	}

	/* Compute the number of datums (access width data items) */

	mask = ACPI_MASK_BITS_BELOW (obj_desc->common_field.start_field_bit_offset);
	datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length,
			  obj_desc->common_field.access_bit_width);
	field_datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length +
			   obj_desc->common_field.start_field_bit_offset,
			   obj_desc->common_field.access_bit_width);

	/* Get initial Datum from the input buffer */

	ACPI_MEMCPY (&raw_datum, buffer,
		ACPI_MIN(obj_desc->common_field.access_byte_width,
				 buffer_length - buffer_offset));

	merged_datum = raw_datum << obj_desc->common_field.start_field_bit_offset;

	/* Write the entire field */

	for (i = 1; i < field_datum_count; i++) {
		/* Write merged datum to the target field */

		merged_datum &= mask;
		status = acpi_ex_write_with_update_rule (obj_desc, mask, merged_datum, field_offset);
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}

		/* Start new output datum by merging with previous input datum */

		field_offset += obj_desc->common_field.access_byte_width;
		merged_datum = raw_datum >>
			(obj_desc->common_field.access_bit_width - obj_desc->common_field.start_field_bit_offset);
		mask = ACPI_INTEGER_MAX;

		if (i == datum_count) {
			break;
		}

		/* Get the next input datum from the buffer */

		buffer_offset += obj_desc->common_field.access_byte_width;
		ACPI_MEMCPY (&raw_datum, ((char *) buffer) + buffer_offset,
			ACPI_MIN(obj_desc->common_field.access_byte_width,
					 buffer_length - buffer_offset));
		merged_datum |= raw_datum << obj_desc->common_field.start_field_bit_offset;
	}

	/* Mask off any extra bits in the last datum */

	buffer_tail_bits = (obj_desc->common_field.bit_length +
			obj_desc->common_field.start_field_bit_offset) % obj_desc->common_field.access_bit_width;
	if (buffer_tail_bits) {
		mask &= ACPI_MASK_BITS_ABOVE (buffer_tail_bits);
	}

	/* Write the last datum to the field */

	merged_datum &= mask;
	status = acpi_ex_write_with_update_rule (obj_desc, mask, merged_datum, field_offset);

	return_ACPI_STATUS (status);
}