Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 967 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c
new file mode 100644
index 000000000..d769cea14
--- /dev/null
+++ b/drivers/acpi/acpica/exfldio.c
@@ -0,0 +1,967 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: exfldio - Aml Field I/O
+ *
+ * Copyright (C) 2000 - 2022, Intel Corp.
+ *
+ *****************************************************************************/
+
+#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 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);
+}
+
+/*******************************************************************************
+ *
+ * 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);
+}
+
+/*******************************************************************************
+ *
+ * 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);
+}
+
+/*******************************************************************************
+ *
+ * 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
+		 */
+
+		ACPI_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);
+}
+
+/*******************************************************************************
+ *
+ * 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,
+							   &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_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);
+}
+
+/*******************************************************************************
+ *
+ * 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);
+}
+
+/*******************************************************************************
+ *
+ * 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);
+}