/******************************************************************************
*
* Module Name: exfldio - Aml Field I/O
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2003, 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")
/*******************************************************************************
*
* 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.
*
******************************************************************************/
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 (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",
obj_desc->common_field.node->name.ascii, obj_desc->common_field.access_byte_width,
rgn_desc->region.node->name.ascii, 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",
obj_desc->common_field.node->name.ascii, obj_desc->common_field.base_byte_offset,
field_datum_byte_offset, obj_desc->common_field.access_byte_width,
rgn_desc->region.node->name.ascii, rgn_desc->region.length));
#ifdef CONFIG_ACPI_RELAXED_AML
{
/*
* Allow access to the field if it is within the region size
* rounded up to a multiple of the access byte width. This
* overcomes "off-by-one" programming errors in the AML often
* found in Toshiba laptops. These errors were allowed by
* the Microsoft ASL compiler.
*/
u32 rounded_length = ACPI_ROUND_UP(rgn_desc->region.length,
obj_desc->common_field.access_byte_width);
if (rounded_length < (obj_desc->common_field.base_byte_offset
+ field_datum_byte_offset
+ obj_desc->common_field.access_byte_width)) {
return_ACPI_STATUS (AE_AML_REGION_LIMIT);
} else {
static int warn_once = 1;
if (warn_once) {
// Could also associate a flag with each field, and
// warn once for each field.
ACPI_REPORT_WARNING((
"The ACPI AML in your computer contains errors, "
"please nag the manufacturer to correct it.\n"));
ACPI_REPORT_WARNING((
"Allowing relaxed access to fields; "
"turn on CONFIG_ACPI_DEBUG for details.\n"));
warn_once = 0;
}
return_ACPI_STATUS (AE_OK);
}
}
#else
return_ACPI_STATUS (AE_AML_REGION_LIMIT);
#endif
}
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_HIDWORD (address), ACPI_LODWORD (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_DEBUG_PRINT ((ACPI_DB_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.
*
******************************************************************************/
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)
*
******************************************************************************/
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;
value = &local_value; /* To support reads without saving return 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 op_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.
*/
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_DEBUG_PRINT ((ACPI_DB_ERROR, "%p, Wrong object type - %s\n",
obj_desc, acpi_ut_get_object_type_name (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_HIDWORD (*value), ACPI_LODWORD (*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_HIDWORD (*value), ACPI_LODWORD (*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,
¤t_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_HIDWORD (mask), ACPI_LODWORD (mask),
field_datum_byte_offset,
obj_desc->common_field.access_byte_width,
ACPI_HIDWORD (field_value), ACPI_LODWORD (field_value),
ACPI_HIDWORD (merged_value),ACPI_LODWORD (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_get_buffer_datum
*
* PARAMETERS: Datum - Where the Datum is returned
* Buffer - Raw field buffer
* buffer_length - Entire length (used for big-endian only)
* byte_granularity - 1/2/4/8 Granularity of the field
* (aka Datum Size)
* buffer_offset - Datum offset into the buffer
*
* RETURN: none
*
* DESCRIPTION: Get a datum from the buffer according to the buffer field
* byte granularity
*
******************************************************************************/
void
acpi_ex_get_buffer_datum (
acpi_integer *datum,
void *buffer,
u32 buffer_length,
u32 byte_granularity,
u32 buffer_offset)
{
u32 index;
ACPI_FUNCTION_TRACE_U32 ("ex_get_buffer_datum", byte_granularity);
/* Get proper index into buffer (handles big/little endian) */
index = ACPI_BUFFER_INDEX (buffer_length, buffer_offset, byte_granularity);
/* Move the requested number of bytes */
switch (byte_granularity) {
case ACPI_FIELD_BYTE_GRANULARITY:
*datum = ((u8 *) buffer) [index];
break;
case ACPI_FIELD_WORD_GRANULARITY:
ACPI_MOVE_16_TO_64 (datum, &(((u16 *) buffer) [index]));
break;
case ACPI_FIELD_DWORD_GRANULARITY:
ACPI_MOVE_32_TO_64 (datum, &(((u32 *) buffer) [index]));
break;
case ACPI_FIELD_QWORD_GRANULARITY:
ACPI_MOVE_64_TO_64 (datum, &(((u64 *) buffer) [index]));
break;
default:
/* Should not get here */
break;
}
return_VOID;
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_set_buffer_datum
*
* PARAMETERS: merged_datum - Value to store
* Buffer - Receiving buffer
* buffer_length - Entire length (used for big-endian only)
* byte_granularity - 1/2/4/8 Granularity of the field
* (aka Datum Size)
* buffer_offset - Datum offset into the buffer
*
* RETURN: none
*
* DESCRIPTION: Store the merged datum to the buffer according to the
* byte granularity
*
******************************************************************************/
void
acpi_ex_set_buffer_datum (
acpi_integer merged_datum,
void *buffer,
u32 buffer_length,
u32 byte_granularity,
u32 buffer_offset)
{
u32 index;
ACPI_FUNCTION_TRACE_U32 ("ex_set_buffer_datum", byte_granularity);
/* Get proper index into buffer (handles big/little endian) */
index = ACPI_BUFFER_INDEX (buffer_length, buffer_offset, byte_granularity);
/* Move the requested number of bytes */
switch (byte_granularity) {
case ACPI_FIELD_BYTE_GRANULARITY:
((u8 *) buffer) [index] = (u8) merged_datum;
break;
case ACPI_FIELD_WORD_GRANULARITY:
ACPI_MOVE_64_TO_16 (&(((u16 *) buffer)[index]), &merged_datum);
break;
case ACPI_FIELD_DWORD_GRANULARITY:
ACPI_MOVE_64_TO_32 (&(((u32 *) buffer)[index]), &merged_datum);
break;
case ACPI_FIELD_QWORD_GRANULARITY:
ACPI_MOVE_64_TO_64 (&(((u64 *) buffer)[index]), &merged_datum);
break;
default:
/* Should not get here */
break;
}
return_VOID;
}
/*******************************************************************************
*
* 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 (
union acpi_operand_object *obj_desc,
void *buffer,
u32 buffer_length)
{
acpi_status status;
u32 field_datum_byte_offset;
u32 datum_offset;
acpi_integer previous_raw_datum;
acpi_integer this_raw_datum = 0;
acpi_integer merged_datum = 0;
u32 byte_field_length;
u32 datum_count;
ACPI_FUNCTION_TRACE ("ex_extract_from_field");
/*
* The field must fit within the caller's buffer
*/
byte_field_length = ACPI_ROUND_BITS_UP_TO_BYTES (obj_desc->common_field.bit_length);
if (byte_field_length > buffer_length) {
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Field size %X (bytes) too large for buffer (%X)\n",
byte_field_length, buffer_length));
return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
}
/* Convert field byte count to datum count, round up if necessary */
datum_count = ACPI_ROUND_UP_TO (byte_field_length,
obj_desc->common_field.access_byte_width);
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"byte_len %X, datum_len %X, byte_gran %X\n",
byte_field_length, datum_count,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).
*/
ACPI_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_field_datum_io (obj_desc, field_datum_byte_offset,
&previous_raw_datum, ACPI_READ);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
/* We might actually be done if the request fits in one datum */
if ((datum_count == 1) &&
(obj_desc->common_field.flags & AOPOBJ_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 &= ACPI_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, buffer_length,
obj_desc->common_field.access_byte_width, datum_offset);
return_ACPI_STATUS (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.
*
* We could just split the aligned and non-aligned cases since the
* aligned case is so very simple, but this would require more code.
*/
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_field_datum_io (obj_desc, field_datum_byte_offset,
&this_raw_datum, ACPI_READ);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (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 &=
ACPI_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, buffer_length,
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_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* 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 (
union acpi_operand_object *obj_desc,
void *buffer,
u32 buffer_length)
{
acpi_status status;
u32 field_datum_byte_offset;
u32 datum_offset;
acpi_integer mask;
acpi_integer merged_datum;
acpi_integer previous_raw_datum;
acpi_integer this_raw_datum;
u32 byte_field_length;
u32 datum_count;
ACPI_FUNCTION_TRACE ("ex_insert_into_field");
/*
* 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 = ACPI_ROUND_BITS_UP_TO_BYTES (
obj_desc->common_field.bit_length);
if (buffer_length < byte_field_length) {
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Buffer length %X too small for field %X\n",
buffer_length, byte_field_length));
return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
}
byte_field_length = ACPI_ROUND_BITS_UP_TO_BYTES (
obj_desc->common_field.start_field_bit_offset +
obj_desc->common_field.bit_length);
/* Convert byte count to datum count, round up if necessary */
datum_count = ACPI_ROUND_UP_TO (byte_field_length,
obj_desc->common_field.access_byte_width);
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Bytes %X, Datums %X, byte_gran %X\n",
byte_field_length, datum_count, 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, buffer_length,
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 = ACPI_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.flags & AOPOBJ_SINGLE_DATUM) &&
obj_desc->common_field.end_field_valid_bits) {
/* There are bits above the field, mask them off also */
mask &= ACPI_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_with_update_rule (obj_desc, mask, merged_datum,
field_datum_byte_offset);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
/* We just wrote the first datum */
datum_offset++;
/* If the entire field fits within one datum, we are done. */
if ((datum_count == 1) &&
(obj_desc->common_field.flags & AOPOBJ_SINGLE_DATUM)) {
return_ACPI_STATUS (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) {
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, buffer_length,
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.
*/
datum_offset++;
if ((datum_offset == datum_count) &&
(obj_desc->common_field.end_field_valid_bits)) {
/*
* If there are dangling non-aligned bits, perform one more merged write
* Else - field is aligned at the end, no need for any more writes
*/
/*
* 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 = ACPI_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_with_update_rule (obj_desc, mask, merged_datum,
field_datum_byte_offset);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
}
else {
/* Normal (aligned) case -- write the completed datum */
status = acpi_ex_field_datum_io (obj_desc, field_datum_byte_offset,
&merged_datum, ACPI_WRITE);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (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_ACPI_STATUS (status);
}
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