Release 4.7 drivers/acpi/acpica/exfldio.c
  
  
/******************************************************************************
 *
 * Module Name: exfldio - Aml Field I/O
 *
 *****************************************************************************/
/*
 * Copyright (C) 2000 - 2016, Intel Corp.
 * 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 "accommon.h"
#include "acinterp.h"
#include "amlcode.h"
#include "acevents.h"
#include "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, u64 *value, u32 read_write);
static u8
acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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;
	u8 space_id;
	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 (rgn_desc->common.type != ACPI_TYPE_REGION) {
		ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
			    rgn_desc->common.type,
			    acpi_ut_get_object_type_name(rgn_desc)));
		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
	}
	space_id = rgn_desc->region.space_id;
	/* Validate the Space ID */
	if (!acpi_is_valid_space_id(space_id)) {
		ACPI_ERROR((AE_INFO,
			    "Invalid/unknown Address Space ID: 0x%2.2X",
			    space_id));
		return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
	}
	/*
         * 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);
		}
	}
	/*
         * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
         * address space and the request cannot be directly validated
         */
	if (space_id == ACPI_ADR_SPACE_SMBUS ||
	    space_id == ACPI_ADR_SPACE_GSBUS ||
	    space_id == ACPI_ADR_SPACE_IPMI) {
		/* SMBus or IPMI 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. acpi_size cast for 64-bit compile.
                         */
			if (ACPI_ROUND_UP(rgn_desc->region.length,
					  obj_desc->common_field.
					  access_byte_width) >=
			    ((acpi_size)obj_desc->common_field.
			     base_byte_offset +
			     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_ERROR((AE_INFO,
				    "Field [%4.4s] access width (%u bytes) "
				    "too large for region [%4.4s] (length %u)",
				    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_ERROR((AE_INFO,
			    "Field [%4.4s] Base+Offset+Width %u+%u+%u "
			    "is beyond end of region [%4.4s] (length %u)",
			    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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| linus torvalds | linus torvalds | 186 | 46.15% | 2 | 9.09% | 
| len brown | len brown | 95 | 23.57% | 5 | 22.73% | 
| robert moore | robert moore | 73 | 18.11% | 10 | 45.45% | 
| andy grover | andy grover | 44 | 10.92% | 4 | 18.18% | 
| lin ming | lin ming | 5 | 1.24% | 1 | 4.55% | 
 | Total | 403 | 100.00% | 22 | 100.00% | 
/*******************************************************************************
 *
 * 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
 *                                        64 bits)
 *              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, u64 *value, u32 function)
{
	acpi_status status;
	union acpi_operand_object *rgn_desc;
	u32 region_offset;
	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;
	region_offset =
	    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, ByteBase %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(rgn_desc->region.address +
						 region_offset)));
	/* Invoke the appropriate address_space/op_region handler */
	status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
						function, region_offset,
						ACPI_MUL_8(obj_desc->
							   common_field.
							   access_byte_width),
						value);
	if (ACPI_FAILURE(status)) {
		if (status == AE_NOT_IMPLEMENTED) {
			ACPI_ERROR((AE_INFO,
				    "Region %s (ID=%u) not implemented",
				    acpi_ut_get_region_name(rgn_desc->region.
							    space_id),
				    rgn_desc->region.space_id));
		} else if (status == AE_NOT_EXIST) {
			ACPI_ERROR((AE_INFO,
				    "Region %s (ID=%u) has no handler",
				    acpi_ut_get_region_name(rgn_desc->region.
							    space_id),
				    rgn_desc->region.space_id));
		}
	}
	return_ACPI_STATUS(status);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| linus torvalds | linus torvalds | 159 | 60.00% | 2 | 14.29% | 
| andy grover | andy grover | 80 | 30.19% | 4 | 28.57% | 
| robert moore | robert moore | 24 | 9.06% | 7 | 50.00% | 
| lv zheng | lv zheng | 2 | 0.75% | 1 | 7.14% | 
 | Total | 265 | 100.00% | 14 | 100.00% | 
/*******************************************************************************
 *
 * 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, u64 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 >= ((u64) 1 << obj_desc->common_field.bit_length)) {
		/*
                 * The Value is larger than the maximum value that can fit into
                 * the register.
                 */
		ACPI_ERROR((AE_INFO,
			    "Index value 0x%8.8X%8.8X overflows field width 0x%X",
			    ACPI_FORMAT_UINT64(value),
			    obj_desc->common_field.bit_length));
		return (TRUE);
	}
	/* The Value will fit into the field with no truncation */
	return (FALSE);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| andy grover | andy grover | 46 | 55.42% | 3 | 42.86% | 
| robert moore | robert moore | 23 | 27.71% | 3 | 42.86% | 
| linus torvalds | linus torvalds | 14 | 16.87% | 1 | 14.29% | 
 | Total | 83 | 100.00% | 7 | 100.00% | 
/*******************************************************************************
 *
 * 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, u64 *value, u32 read_write)
{
	acpi_status status;
	u64 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 (obj_desc->common.type) {
	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.
                         */
			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.
                         */
			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,
					      (u64) 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,
					      (u64) 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);
		}
		if (read_write == ACPI_READ) {
			/* Read the datum from the data_register */
			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
					  "Read from Data Register\n"));
			status =
			    acpi_ex_extract_from_field(obj_desc->index_field.
						       data_obj, value,
						       sizeof(u64));
		} else {
			/* Write the datum to the data_register */
			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
					  "Write to Data Register: Value %8.8X%8.8X\n",
					  ACPI_FORMAT_UINT64(*value)));
			status =
			    acpi_ex_insert_into_field(obj_desc->index_field.
						      data_obj, value,
						      sizeof(u64));
		}
		break;
	default:
		ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
			    obj_desc->common.type));
		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 %u\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 %u\n",
					  ACPI_FORMAT_UINT64(*value),
					  obj_desc->common_field.
					  access_byte_width));
		}
	}
	return_ACPI_STATUS(status);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| andy grover | andy grover | 331 | 61.87% | 5 | 27.78% | 
| linus torvalds | linus torvalds | 110 | 20.56% | 2 | 11.11% | 
| robert moore | robert moore | 52 | 9.72% | 9 | 50.00% | 
| len brown | len brown | 42 | 7.85% | 2 | 11.11% | 
 | Total | 535 | 100.00% | 18 | 100.00% | 
/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_write_with_update_rule
 *
 * PARAMETERS:  obj_desc                - Field to be written
 *              mask                    - bitmask within field datum
 *              field_value             - Value to write
 *              field_datum_byte_offset - Offset of datum within field
 *
 * 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,
			       u64 mask,
			       u64 field_value, u32 field_datum_byte_offset)
{
	acpi_status status = AE_OK;
	u64 merged_value;
	u64 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_UINT64_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_ERROR((AE_INFO,
				    "Unknown UpdateRule value: 0x%X",
				    (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, DatumOffset %X, Width %X, "
			  "Value %8.8X%8.8X, MergedValue %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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| andy grover | andy grover | 152 | 64.96% | 2 | 18.18% | 
| len brown | len brown | 38 | 16.24% | 2 | 18.18% | 
| linus torvalds | linus torvalds | 32 | 13.68% | 2 | 18.18% | 
| robert moore | robert moore | 12 | 5.13% | 5 | 45.45% | 
 | Total | 234 | 100.00% | 11 | 100.00% | 
/*******************************************************************************
 *
 * 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;
	u64 raw_datum;
	u64 merged_datum;
	u32 field_offset = 0;
	u32 buffer_offset = 0;
	u32 buffer_tail_bits;
	u32 datum_count;
	u32 field_datum_count;
	u32 access_bit_width;
	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_ERROR((AE_INFO,
			    "Field size %u (bits) is too large for buffer (%u)",
			    obj_desc->common_field.bit_length, buffer_length));
		return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
	}
	memset(buffer, 0, buffer_length);
	access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
	/* Handle the simple case here */
	if ((obj_desc->common_field.start_field_bit_offset == 0) &&
	    (obj_desc->common_field.bit_length == access_bit_width)) {
		if (buffer_length >= sizeof(u64)) {
			status =
			    acpi_ex_field_datum_io(obj_desc, 0, buffer,
						   ACPI_READ);
		} else {
			/* Use raw_datum (u64) to handle buffers < 64 bits */
			status =
			    acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
						   ACPI_READ);
			memcpy(buffer, &raw_datum, buffer_length);
		}
		return_ACPI_STATUS(status);
	}
/* TBD: Move to common setup code */
	/* Field algorithm is limited to sizeof(u64), truncate if needed */
	if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
		obj_desc->common_field.access_byte_width = sizeof(u64);
		access_bit_width = sizeof(u64) * 8;
	}
	/* Compute the number of datums (access width data items) */
	datum_count =
	    ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
			     access_bit_width);
	field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
					     obj_desc->common_field.
					     start_field_bit_offset,
					     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.
                 *
                 * Note: Before the shift, check if the shift value will be larger than
                 * the integer size. If so, there is no need to perform the operation.
                 * This avoids the differences in behavior between different compilers
                 * concerning shift values larger than the target data width.
                 */
		if (access_bit_width -
		    obj_desc->common_field.start_field_bit_offset <
		    ACPI_INTEGER_BIT_SIZE) {
			merged_datum |=
			    raw_datum << (access_bit_width -
					  obj_desc->common_field.
					  start_field_bit_offset);
		}
		if (i == datum_count) {
			break;
		}
		/* Write merged datum to target buffer */
		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 % access_bit_width;
	if (buffer_tail_bits) {
		merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
	}
	/* Write the last datum to the buffer */
	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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| len brown | len brown | 199 | 39.56% | 3 | 20.00% | 
| robert moore | robert moore | 157 | 31.21% | 8 | 53.33% | 
| andy grover | andy grover | 96 | 19.09% | 2 | 13.33% | 
| linus torvalds | linus torvalds | 51 | 10.14% | 2 | 13.33% | 
 | Total | 503 | 100.00% | 15 | 100.00% | 
/*******************************************************************************
 *
 * 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)
{
	void *new_buffer;
	acpi_status status;
	u64 mask;
	u64 width_mask;
	u64 merged_datum;
	u64 raw_datum = 0;
	u32 field_offset = 0;
	u32 buffer_offset = 0;
	u32 buffer_tail_bits;
	u32 datum_count;
	u32 field_datum_count;
	u32 access_bit_width;
	u32 required_length;
	u32 i;
	ACPI_FUNCTION_TRACE(ex_insert_into_field);
	/* Validate input buffer */
	new_buffer = NULL;
	required_length =
	    ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
	/*
         * We must have a buffer that is at least as long as the field
         * we are writing to. This is because individual fields are
         * indivisible and partial writes are not supported -- as per
         * the ACPI specification.
         */
	if (buffer_length < required_length) {
		/* We need to create a new buffer */
		new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
		if (!new_buffer) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}
		/*
                 * Copy the original data to the new buffer, starting
                 * at Byte zero. All unused (upper) bytes of the
                 * buffer will be 0.
                 */
		memcpy((char *)new_buffer, (char *)buffer, buffer_length);
		buffer = new_buffer;
		buffer_length = required_length;
	}
/* TBD: Move to common setup code */
	/* Algo is limited to sizeof(u64), so cut the access_byte_width */
	if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
		obj_desc->common_field.access_byte_width = sizeof(u64);
	}
	access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
	/* Create the bitmasks used for bit insertion */
	width_mask = ACPI_MASK_BITS_ABOVE_64(access_bit_width);
	mask = width_mask &
	    ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
	/* Compute the number of datums (access width data items) */
	datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
				       access_bit_width);
	field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
					     obj_desc->common_field.
					     start_field_bit_offset,
					     access_bit_width);
	/* Get initial Datum from the input buffer */
	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)) {
			goto exit;
		}
		field_offset += obj_desc->common_field.access_byte_width;
		/*
                 * Start new output datum by merging with previous input datum
                 * if necessary.
                 *
                 * Note: Before the shift, check if the shift value will be larger than
                 * the integer size. If so, there is no need to perform the operation.
                 * This avoids the differences in behavior between different compilers
                 * concerning shift values larger than the target data width.
                 */
		if ((access_bit_width -
		     obj_desc->common_field.start_field_bit_offset) <
		    ACPI_INTEGER_BIT_SIZE) {
			merged_datum =
			    raw_datum >> (access_bit_width -
					  obj_desc->common_field.
					  start_field_bit_offset);
		} else {
			merged_datum = 0;
		}
		mask = width_mask;
		if (i == datum_count) {
			break;
		}
		/* Get the next input datum from the buffer */
		buffer_offset += obj_desc->common_field.access_byte_width;
		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) %
	    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);
exit:
	/* Free temporary buffer if we used one */
	if (new_buffer) {
		ACPI_FREE(new_buffer);
	}
	return_ACPI_STATUS(status);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| linus torvalds | linus torvalds | 170 | 34.76% | 2 | 13.33% | 
| robert moore | robert moore | 162 | 33.13% | 8 | 53.33% | 
| len brown | len brown | 150 | 30.67% | 2 | 13.33% | 
| andy grover | andy grover | 5 | 1.02% | 2 | 13.33% | 
| lv zheng | lv zheng | 2 | 0.41% | 1 | 6.67% | 
 | Total | 489 | 100.00% | 15 | 100.00% | 
Overall Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| andy grover | andy grover | 756 | 29.14% | 9 | 18.00% | 
| linus torvalds | linus torvalds | 739 | 28.49% | 2 | 4.00% | 
| robert moore | robert moore | 560 | 21.59% | 27 | 54.00% | 
| len brown | len brown | 529 | 20.39% | 8 | 16.00% | 
| lin ming | lin ming | 5 | 0.19% | 1 | 2.00% | 
| lv zheng | lv zheng | 4 | 0.15% | 2 | 4.00% | 
| patrick mochel | patrick mochel | 1 | 0.04% | 1 | 2.00% | 
 | Total | 2594 | 100.00% | 50 | 100.00% | 
  
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