patch-2.4.6 linux/drivers/acpi/executer/exfldio.c
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- Lines: 828
- Date:
Wed Jun 20 17:47:40 2001
- Orig file:
v2.4.5/linux/drivers/acpi/executer/exfldio.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.5/linux/drivers/acpi/executer/exfldio.c linux/drivers/acpi/executer/exfldio.c
@@ -0,0 +1,827 @@
+/******************************************************************************
+ *
+ * Module Name: exfldio - Aml Field I/O
+ * $Revision: 57 $
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000, 2001 R. Byron Moore
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+#include "acpi.h"
+#include "acinterp.h"
+#include "amlcode.h"
+#include "acnamesp.h"
+#include "achware.h"
+#include "acevents.h"
+#include "acdispat.h"
+
+
+#define _COMPONENT ACPI_EXECUTER
+ MODULE_NAME ("exfldio")
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_setup_field
+ *
+ * PARAMETERS: *Obj_desc - Field to be read or written
+ * Field_datum_byte_offset - Current offset into the field
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Common processing for Acpi_ex_extract_from_field and
+ * Acpi_ex_insert_into_field
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_setup_field (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ u32 field_datum_byte_offset)
+{
+ ACPI_STATUS status = AE_OK;
+ ACPI_OPERAND_OBJECT *rgn_desc;
+
+
+ /* Parameter validation */
+
+ rgn_desc = obj_desc->common_field.region_obj;
+ if (!obj_desc || !rgn_desc) {
+ return (AE_AML_NO_OPERAND);
+ }
+
+ if (ACPI_TYPE_REGION != rgn_desc->common.type) {
+ return (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->region.flags & AOPOBJ_DATA_VALID)) {
+
+ status = acpi_ds_get_region_arguments (rgn_desc);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+ }
+
+
+ /*
+ * 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 (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.
+ */
+ }
+
+ /*
+ * Offset rounded up to next multiple of field width
+ * exceeds region length, indicate an error
+ */
+ return (AE_AML_REGION_LIMIT);
+ }
+
+ return (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_read_field_datum
+ *
+ * PARAMETERS: *Obj_desc - Field to be read
+ * *Value - Where to store value (must be 32 bits)
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Retrieve the value of the given field
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_read_field_datum (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ u32 field_datum_byte_offset,
+ u32 *value)
+{
+ ACPI_STATUS status;
+ ACPI_OPERAND_OBJECT *rgn_desc;
+ ACPI_PHYSICAL_ADDRESS address;
+ u32 local_value;
+
+
+ if (!value) {
+ local_value = 0;
+ value = &local_value; /* support reads without saving value */
+ }
+
+ /* Clear the entire return buffer first, [Very Important!] */
+
+ *value = 0;
+
+
+ /*
+ * Buffer_fields - Read from a Buffer
+ * Other Fields - Read from a Operation Region.
+ */
+ switch (obj_desc->common.type) {
+ case ACPI_TYPE_BUFFER_FIELD:
+
+ /*
+ * For Buffer_fields, we only need to copy the data from the
+ * source buffer. Length is the field width in bytes.
+ */
+ 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);
+ status = AE_OK;
+ break;
+
+
+ case INTERNAL_TYPE_REGION_FIELD:
+ case INTERNAL_TYPE_BANK_FIELD:
+
+ /*
+ * For other fields, we need to go through an Operation Region
+ * (Only types that will get here are Region_fields and Bank_fields)
+ */
+ status = acpi_ex_setup_field (obj_desc, field_datum_byte_offset);
+ if (ACPI_FAILURE (status)) {
+ return (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;
+
+
+ /* Invoke the appropriate Address_space/Op_region handler */
+
+ status = acpi_ev_address_space_dispatch (rgn_desc, ACPI_READ_ADR_SPACE,
+ address, obj_desc->common_field.access_bit_width, value);
+
+ break;
+
+
+ default:
+
+ status = AE_AML_INTERNAL;
+ break;
+ }
+
+
+ return (status);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_get_buffer_datum
+ *
+ * PARAMETERS: Merged_datum - Value to store
+ * Buffer - Receiving buffer
+ * Byte_granularity - 1/2/4 Granularity of the field
+ * (aka Datum Size)
+ * Offset - Datum offset into the buffer
+ *
+ * RETURN: none
+ *
+ * DESCRIPTION: Store the merged datum to the buffer according to the
+ * byte granularity
+ *
+ ******************************************************************************/
+
+static void
+acpi_ex_get_buffer_datum(
+ u32 *datum,
+ void *buffer,
+ u32 byte_granularity,
+ u32 offset)
+{
+
+ switch (byte_granularity) {
+ case ACPI_FIELD_BYTE_GRANULARITY:
+ *datum = ((u8 *) buffer) [offset];
+ break;
+
+ case ACPI_FIELD_WORD_GRANULARITY:
+ MOVE_UNALIGNED16_TO_32 (datum, &(((u16 *) buffer) [offset]));
+ break;
+
+ case ACPI_FIELD_DWORD_GRANULARITY:
+ MOVE_UNALIGNED32_TO_32 (datum, &(((u32 *) buffer) [offset]));
+ break;
+ }
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_set_buffer_datum
+ *
+ * PARAMETERS: Merged_datum - Value to store
+ * Buffer - Receiving buffer
+ * Byte_granularity - 1/2/4 Granularity of the field
+ * (aka Datum Size)
+ * Offset - Datum offset into the buffer
+ *
+ * RETURN: none
+ *
+ * DESCRIPTION: Store the merged datum to the buffer according to the
+ * byte granularity
+ *
+ ******************************************************************************/
+
+static void
+acpi_ex_set_buffer_datum (
+ u32 merged_datum,
+ void *buffer,
+ u32 byte_granularity,
+ u32 offset)
+{
+
+ switch (byte_granularity) {
+ case ACPI_FIELD_BYTE_GRANULARITY:
+ ((u8 *) buffer) [offset] = (u8) merged_datum;
+ break;
+
+ case ACPI_FIELD_WORD_GRANULARITY:
+ MOVE_UNALIGNED16_TO_16 (&(((u16 *) buffer)[offset]), &merged_datum);
+ break;
+
+ case ACPI_FIELD_DWORD_GRANULARITY:
+ MOVE_UNALIGNED32_TO_32 (&(((u32 *) buffer)[offset]), &merged_datum);
+ break;
+ }
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_extract_from_field
+ *
+ * PARAMETERS: *Obj_desc - Field to be read
+ * *Value - Where to store value
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Retrieve the value of the given field
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_extract_from_field (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ void *buffer,
+ u32 buffer_length)
+{
+ ACPI_STATUS status;
+ u32 field_datum_byte_offset;
+ u32 datum_offset;
+ u32 previous_raw_datum;
+ u32 this_raw_datum = 0;
+ u32 merged_datum = 0;
+ u32 byte_field_length;
+ u32 datum_count;
+
+
+ /*
+ * The field must fit within the caller's buffer
+ */
+ byte_field_length = ROUND_BITS_UP_TO_BYTES (obj_desc->common_field.bit_length);
+ if (byte_field_length > buffer_length) {
+ return (AE_BUFFER_OVERFLOW);
+ }
+
+ /* Convert field byte count to datum count, round up if necessary */
+
+ datum_count = ROUND_UP_TO (byte_field_length, obj_desc->common_field.access_byte_width);
+
+
+ /*
+ * Clear the caller's buffer (the whole buffer length as given)
+ * This is very important, especially in the cases where a byte is read,
+ * but the buffer is really a u32 (4 bytes).
+ */
+ MEMSET (buffer, 0, buffer_length);
+
+ /* Read the first raw datum to prime the loop */
+
+ field_datum_byte_offset = 0;
+ datum_offset= 0;
+
+ status = acpi_ex_read_field_datum (obj_desc, field_datum_byte_offset, &previous_raw_datum);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+
+
+ /* We might actually be done if the request fits in one datum */
+
+ if ((datum_count == 1) &&
+ (obj_desc->common_field.access_flags & AFIELD_SINGLE_DATUM)) {
+ /* 1) Shift the valid data bits down to start at bit 0 */
+
+ merged_datum = (previous_raw_datum >> obj_desc->common_field.start_field_bit_offset);
+
+ /* 2) Mask off any upper unused bits (bits not part of the field) */
+
+ if (obj_desc->common_field.end_buffer_valid_bits) {
+ merged_datum &= MASK_BITS_ABOVE (obj_desc->common_field.end_buffer_valid_bits);
+ }
+
+ /* Store the datum to the caller buffer */
+
+ acpi_ex_set_buffer_datum (merged_datum, buffer, obj_desc->common_field.access_byte_width,
+ datum_offset);
+
+ return (AE_OK);
+ }
+
+
+ /* We need to get more raw data to complete one or more field data */
+
+ while (datum_offset < datum_count) {
+ field_datum_byte_offset += obj_desc->common_field.access_byte_width;
+
+ /*
+ * If the field is aligned on a byte boundary, we don't want
+ * to perform a final read, since this would potentially read
+ * past the end of the region.
+ *
+ * TBD: [Investigate] It may make more sense to just split the aligned
+ * and non-aligned cases since the aligned case is so very simple,
+ */
+ if ((obj_desc->common_field.start_field_bit_offset != 0) ||
+ ((obj_desc->common_field.start_field_bit_offset == 0) &&
+ (datum_offset < (datum_count -1)))) {
+ /*
+ * Get the next raw datum, it contains some or all bits
+ * of the current field datum
+ */
+ status = acpi_ex_read_field_datum (obj_desc, field_datum_byte_offset, &this_raw_datum);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+ }
+
+ /*
+ * Create the (possibly) merged datum to be stored to the caller buffer
+ */
+ if (obj_desc->common_field.start_field_bit_offset == 0) {
+ /* Field is not skewed and we can just copy the datum */
+
+ merged_datum = previous_raw_datum;
+ }
+
+ else {
+ /*
+ * Put together the appropriate bits of the two raw data to make a
+ * single complete field datum
+ *
+ * 1) Normalize the first datum down to bit 0
+ */
+ merged_datum = (previous_raw_datum >> obj_desc->common_field.start_field_bit_offset);
+
+ /* 2) Insert the second datum "above" the first datum */
+
+ merged_datum |= (this_raw_datum << obj_desc->common_field.datum_valid_bits);
+
+ if ((datum_offset >= (datum_count -1))) {
+ /*
+ * This is the last iteration of the loop. We need to clear
+ * any unused bits (bits that are not part of this field) that
+ * came from the last raw datum before we store the final
+ * merged datum into the caller buffer.
+ */
+ if (obj_desc->common_field.end_buffer_valid_bits) {
+ merged_datum &=
+ MASK_BITS_ABOVE (obj_desc->common_field.end_buffer_valid_bits);
+ }
+ }
+ }
+
+
+ /*
+ * Store the merged field datum in the caller's buffer, according to
+ * the granularity of the field (size of each datum).
+ */
+ acpi_ex_set_buffer_datum (merged_datum, buffer, obj_desc->common_field.access_byte_width,
+ datum_offset);
+
+ /*
+ * Save the raw datum that was just acquired since it may contain bits
+ * of the *next* field datum. Update offsets
+ */
+ previous_raw_datum = this_raw_datum;
+ datum_offset++;
+ }
+
+
+ return (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_write_field_datum
+ *
+ * PARAMETERS: *Obj_desc - Field to be set
+ * Value - Value to store
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Store the value into the given field
+ *
+ ******************************************************************************/
+
+static ACPI_STATUS
+acpi_ex_write_field_datum (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ u32 field_datum_byte_offset,
+ u32 value)
+{
+ ACPI_STATUS status = AE_OK;
+ ACPI_OPERAND_OBJECT *rgn_desc = NULL;
+ ACPI_PHYSICAL_ADDRESS address;
+
+
+ /*
+ * Buffer_fields - Read from a Buffer
+ * Other Fields - Read from a Operation Region.
+ */
+ switch (obj_desc->common.type) {
+ case ACPI_TYPE_BUFFER_FIELD:
+
+ /*
+ * For Buffer_fields, we only need to copy the data to the
+ * target buffer. Length is the field width in bytes.
+ */
+ 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 INTERNAL_TYPE_REGION_FIELD:
+ case INTERNAL_TYPE_BANK_FIELD:
+
+ /*
+ * For other fields, we need to go through an Operation Region
+ * (Only types that will get here are Region_fields and Bank_fields)
+ */
+ status = acpi_ex_setup_field (obj_desc, field_datum_byte_offset);
+ if (ACPI_FAILURE (status)) {
+ return (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;
+
+ /* Invoke the appropriate Address_space/Op_region handler */
+
+ status = acpi_ev_address_space_dispatch (rgn_desc, ACPI_WRITE_ADR_SPACE,
+ address, obj_desc->common_field.access_bit_width, &value);
+
+
+
+ break;
+
+
+ default:
+
+ status = AE_AML_INTERNAL;
+ break;
+ }
+
+
+ return (status);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_write_field_datum_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
+ *
+ ******************************************************************************/
+
+static ACPI_STATUS
+acpi_ex_write_field_datum_with_update_rule (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ u32 mask,
+ u32 field_value,
+ u32 field_datum_byte_offset)
+{
+ ACPI_STATUS status = AE_OK;
+ u32 merged_value;
+ u32 current_value;
+
+
+ /* 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_UINT32_MAX) {
+ /* Decode the update rule */
+
+ switch (obj_desc->common_field.update_rule) {
+
+ case 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 << (sizeof (mask) * 8 -
+ obj_desc->common_field.access_bit_width)) != 0) {
+ /*
+ * Read the current contents of the byte/word/dword containing
+ * the field, and merge with the new field value.
+ */
+ status = acpi_ex_read_field_datum (obj_desc, field_datum_byte_offset,
+ ¤t_value);
+ merged_value |= (current_value & ~mask);
+ }
+ break;
+
+
+ case UPDATE_WRITE_AS_ONES:
+
+ /* Set positions outside the field to all ones */
+
+ merged_value |= ~mask;
+ break;
+
+
+ case UPDATE_WRITE_AS_ZEROS:
+
+ /* Set positions outside the field to all zeros */
+
+ merged_value &= mask;
+ break;
+
+
+ default:
+ return (AE_AML_OPERAND_VALUE);
+ break;
+ }
+ }
+
+
+ /* Write the merged value */
+
+ status = acpi_ex_write_field_datum (obj_desc, field_datum_byte_offset,
+ merged_value);
+
+ return (status);
+}
+
+
+/*******************************************************************************
+ *
+ * FUNCTION: Acpi_ex_insert_into_field
+ *
+ * PARAMETERS: *Obj_desc - Field to be set
+ * Buffer - Value to store
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Store the value into the given field
+ *
+ ******************************************************************************/
+
+ACPI_STATUS
+acpi_ex_insert_into_field (
+ ACPI_OPERAND_OBJECT *obj_desc,
+ void *buffer,
+ u32 buffer_length)
+{
+ ACPI_STATUS status;
+ u32 field_datum_byte_offset;
+ u32 datum_offset;
+ u32 mask;
+ u32 merged_datum;
+ u32 previous_raw_datum;
+ u32 this_raw_datum;
+ u32 byte_field_length;
+ u32 datum_count;
+
+
+ /*
+ * Incoming buffer must be at least as long as the field, we do not
+ * allow "partial" field writes. We do not care if the buffer is
+ * larger than the field, this typically happens when an integer is
+ * written to a field that is actually smaller than an integer.
+ */
+ byte_field_length = ROUND_BITS_UP_TO_BYTES (obj_desc->common_field.bit_length);
+ if (buffer_length < byte_field_length) {
+ /* TBD: Need a better error code */
+
+ return (AE_BUFFER_OVERFLOW);
+ }
+
+ /* Convert byte count to datum count, round up if necessary */
+
+ datum_count = ROUND_UP_TO (byte_field_length, obj_desc->common_field.access_byte_width);
+
+
+ /*
+ * Break the request into up to three parts (similar to an I/O request):
+ * 1) non-aligned part at start
+ * 2) aligned part in middle
+ * 3) non-aligned part at the end
+ */
+ field_datum_byte_offset = 0;
+ datum_offset= 0;
+
+ /* Get a single datum from the caller's buffer */
+
+ acpi_ex_get_buffer_datum (&previous_raw_datum, buffer,
+ obj_desc->common_field.access_byte_width, datum_offset);
+
+ /*
+ * Part1:
+ * Write a partial field datum if field does not begin on a datum boundary
+ * Note: The code in this section also handles the aligned case
+ *
+ * Construct Mask with 1 bits where the field is, 0 bits elsewhere
+ * (Only the bottom 5 bits of Bit_length are valid for a shift operation)
+ *
+ * Mask off bits that are "below" the field (if any)
+ */
+ mask = MASK_BITS_BELOW (obj_desc->common_field.start_field_bit_offset);
+
+ /* If the field fits in one datum, may need to mask upper bits */
+
+ if ((obj_desc->common_field.access_flags & AFIELD_SINGLE_DATUM) &&
+ obj_desc->common_field.end_field_valid_bits) {
+ /* There are bits above the field, mask them off also */
+
+ mask &= MASK_BITS_ABOVE (obj_desc->common_field.end_field_valid_bits);
+ }
+
+ /* Shift and mask the value into the field position */
+
+ merged_datum = (previous_raw_datum << obj_desc->common_field.start_field_bit_offset);
+ merged_datum &= mask;
+
+ /* Apply the update rule (if necessary) and write the datum to the field */
+
+ status = acpi_ex_write_field_datum_with_update_rule (obj_desc, mask, merged_datum,
+ field_datum_byte_offset);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+
+ /* If the entire field fits within one datum, we are done. */
+
+ if ((datum_count == 1) &&
+ (obj_desc->common_field.access_flags & AFIELD_SINGLE_DATUM)) {
+ return (AE_OK);
+ }
+
+ /*
+ * Part2:
+ * Write the aligned data.
+ *
+ * We don't need to worry about the update rule for these data, because
+ * all of the bits in each datum are part of the field.
+ *
+ * The last datum must be special cased because it might contain bits
+ * that are not part of the field -- therefore the "update rule" must be
+ * applied in Part3 below.
+ */
+ while (datum_offset < datum_count) {
+ datum_offset++;
+ field_datum_byte_offset += obj_desc->common_field.access_byte_width;
+
+ /*
+ * Get the next raw buffer datum. It may contain bits of the previous
+ * field datum
+ */
+ acpi_ex_get_buffer_datum (&this_raw_datum, buffer,
+ obj_desc->common_field.access_byte_width, datum_offset);
+
+ /* Create the field datum based on the field alignment */
+
+ if (obj_desc->common_field.start_field_bit_offset != 0) {
+ /*
+ * Put together appropriate bits of the two raw buffer data to make
+ * a single complete field datum
+ */
+ merged_datum =
+ (previous_raw_datum >> obj_desc->common_field.datum_valid_bits) |
+ (this_raw_datum << obj_desc->common_field.start_field_bit_offset);
+ }
+
+ else {
+ /* Field began aligned on datum boundary */
+
+ merged_datum = this_raw_datum;
+ }
+
+
+ /*
+ * Special handling for the last datum if the field does NOT end on
+ * a datum boundary. Update Rule must be applied to the bits outside
+ * the field.
+ */
+ if ((datum_offset == datum_count) &&
+ obj_desc->common_field.end_field_valid_bits) {
+ /*
+ * Part3:
+ * This is the last datum and the field does not end on a datum boundary.
+ * Build the partial datum and write with the update rule.
+ */
+
+ /* Mask off the unused bits above (after) the end-of-field */
+
+ mask = MASK_BITS_ABOVE (obj_desc->common_field.end_field_valid_bits);
+ merged_datum &= mask;
+
+ /* Write the last datum with the update rule */
+
+ status = acpi_ex_write_field_datum_with_update_rule (obj_desc, mask,
+ merged_datum, field_datum_byte_offset);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+ }
+
+ else {
+ /* Normal case -- write the completed datum */
+
+ status = acpi_ex_write_field_datum (obj_desc,
+ field_datum_byte_offset, merged_datum);
+ if (ACPI_FAILURE (status)) {
+ return (status);
+ }
+ }
+
+ /*
+ * Save the most recent datum since it may contain bits of the *next*
+ * field datum. Update current byte offset.
+ */
+ previous_raw_datum = this_raw_datum;
+ }
+
+
+ return (status);
+}
+
+
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)