diff --git a/drivers/acpi/acpica/Makefile b/drivers/acpi/acpica/Makefile
index 1709551..2d09b02 100644
--- a/drivers/acpi/acpica/Makefile
+++ b/drivers/acpi/acpica/Makefile
@@ -177,6 +177,7 @@ acpi-y +=		\
 	utresrc.o	\
 	utstate.o	\
 	utstring.o	\
+	utstrsuppt.o	\
 	utstrtoul64.o	\
 	utxface.o	\
 	utxfinit.o	\
diff --git a/drivers/acpi/acpica/acinterp.h b/drivers/acpi/acpica/acinterp.h
index 29a863c..29555c8 100644
--- a/drivers/acpi/acpica/acinterp.h
+++ b/drivers/acpi/acpica/acinterp.h
@@ -101,7 +101,8 @@ typedef const struct acpi_exdump_info {
  */
 acpi_status
 acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
-			   union acpi_operand_object **result_desc, u32 flags);
+			   union acpi_operand_object **result_desc,
+			   u32 implicit_conversion);
 
 acpi_status
 acpi_ex_convert_to_buffer(union acpi_operand_object *obj_desc,
@@ -424,9 +425,6 @@ acpi_ex_store_object_to_node(union acpi_operand_object *source_desc,
 			     struct acpi_walk_state *walk_state,
 			     u8 implicit_conversion);
 
-#define ACPI_IMPLICIT_CONVERSION        TRUE
-#define ACPI_NO_IMPLICIT_CONVERSION     FALSE
-
 /*
  * exstoren - resolve/store object
  */
diff --git a/drivers/acpi/acpica/acutils.h b/drivers/acpi/acpica/acutils.h
index 745134a..7a568c6 100644
--- a/drivers/acpi/acpica/acutils.h
+++ b/drivers/acpi/acpica/acutils.h
@@ -141,6 +141,11 @@ extern const char *acpi_gbl_ptyp_decode[];
 #define ACPI_MSG_SUFFIX \
 	acpi_os_printf (" (%8.8X/%s-%u)\n", ACPI_CA_VERSION, module_name, line_number)
 
+/* Flags to indicate implicit or explicit string-to-integer conversion */
+
+#define ACPI_IMPLICIT_CONVERSION        TRUE
+#define ACPI_NO_IMPLICIT_CONVERSION     FALSE
+
 /* Types for Resource descriptor entries */
 
 #define ACPI_INVALID_RESOURCE           0
@@ -197,15 +202,29 @@ void acpi_ut_strlwr(char *src_string);
 
 int acpi_ut_stricmp(char *string1, char *string2);
 
-acpi_status acpi_ut_strtoul64(char *string, u32 flags, u64 *ret_integer);
+/*
+ * utstrsuppt - string-to-integer conversion support functions
+ */
+acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value);
+
+acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr);
+
+acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr);
+
+char acpi_ut_remove_leading_zeros(char **string);
+
+u8 acpi_ut_detect_hex_prefix(char **string);
+
+u8 acpi_ut_detect_octal_prefix(char **string);
 
 /*
- * Values for Flags above
- * Note: LIMIT values correspond to acpi_gbl_integer_byte_width values (4/8)
+ * utstrtoul64 - string-to-integer conversion functions
  */
-#define ACPI_STRTOUL_32BIT          0x04	/* 4 bytes */
-#define ACPI_STRTOUL_64BIT          0x08	/* 8 bytes */
-#define ACPI_STRTOUL_BASE16         0x10	/* Default: Base10/16 */
+acpi_status acpi_ut_strtoul64(char *string, u64 *ret_integer);
+
+u64 acpi_ut_explicit_strtoul64(char *string);
+
+u64 acpi_ut_implicit_strtoul64(char *string);
 
 /*
  * utglobal - Global data structures and procedures
diff --git a/drivers/acpi/acpica/dbconvert.c b/drivers/acpi/acpica/dbconvert.c
index 857dbc4..32d546f 100644
--- a/drivers/acpi/acpica/dbconvert.c
+++ b/drivers/acpi/acpica/dbconvert.c
@@ -277,10 +277,7 @@ acpi_db_convert_to_object(acpi_object_type type,
 	default:
 
 		object->type = ACPI_TYPE_INTEGER;
-		status = acpi_ut_strtoul64(string,
-					   (acpi_gbl_integer_byte_width |
-					    ACPI_STRTOUL_BASE16),
-					   &object->integer.value);
+		status = acpi_ut_strtoul64(string, &object->integer.value);
 		break;
 	}
 
diff --git a/drivers/acpi/acpica/dswexec.c b/drivers/acpi/acpica/dswexec.c
index 20d7744..22f45d0 100644
--- a/drivers/acpi/acpica/dswexec.c
+++ b/drivers/acpi/acpica/dswexec.c
@@ -134,7 +134,7 @@ acpi_ds_get_predicate_value(struct acpi_walk_state *walk_state,
 	 * object. Implicitly convert the argument if necessary.
 	 */
 	status = acpi_ex_convert_to_integer(obj_desc, &local_obj_desc,
-					    ACPI_STRTOUL_BASE16);
+					    ACPI_IMPLICIT_CONVERSION);
 	if (ACPI_FAILURE(status)) {
 		goto cleanup;
 	}
diff --git a/drivers/acpi/acpica/exconcat.c b/drivers/acpi/acpica/exconcat.c
index 76bfb7d..59b8de2 100644
--- a/drivers/acpi/acpica/exconcat.c
+++ b/drivers/acpi/acpica/exconcat.c
@@ -156,7 +156,7 @@ acpi_ex_do_concatenate(union acpi_operand_object *operand0,
 
 		status =
 		    acpi_ex_convert_to_integer(local_operand1, &temp_operand1,
-					       ACPI_STRTOUL_BASE16);
+					       ACPI_IMPLICIT_CONVERSION);
 		break;
 
 	case ACPI_TYPE_BUFFER:
diff --git a/drivers/acpi/acpica/exconvrt.c b/drivers/acpi/acpica/exconvrt.c
index f71028e..23ebadb 100644
--- a/drivers/acpi/acpica/exconvrt.c
+++ b/drivers/acpi/acpica/exconvrt.c
@@ -57,10 +57,10 @@ acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 max_length);
  *
  * FUNCTION:    acpi_ex_convert_to_integer
  *
- * PARAMETERS:  obj_desc        - Object to be converted. Must be an
- *                                Integer, Buffer, or String
- *              result_desc     - Where the new Integer object is returned
- *              flags           - Used for string conversion
+ * PARAMETERS:  obj_desc            - Object to be converted. Must be an
+ *                                    Integer, Buffer, or String
+ *              result_desc         - Where the new Integer object is returned
+ *              implicit_conversion - Used for string conversion
  *
  * RETURN:      Status
  *
@@ -70,14 +70,14 @@ acpi_ex_convert_to_ascii(u64 integer, u16 base, u8 *string, u8 max_length);
 
 acpi_status
 acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
-			   union acpi_operand_object **result_desc, u32 flags)
+			   union acpi_operand_object **result_desc,
+			   u32 implicit_conversion)
 {
 	union acpi_operand_object *return_desc;
 	u8 *pointer;
 	u64 result;
 	u32 i;
 	u32 count;
-	acpi_status status;
 
 	ACPI_FUNCTION_TRACE_PTR(ex_convert_to_integer, obj_desc);
 
@@ -123,12 +123,18 @@ acpi_ex_convert_to_integer(union acpi_operand_object *obj_desc,
 		 * hexadecimal as per the ACPI specification. The only exception (as
 		 * of ACPI 3.0) is that the to_integer() operator allows both decimal
 		 * and hexadecimal strings (hex prefixed with "0x").
+		 *
+		 * Explicit conversion is used only by to_integer.
+		 * All other string-to-integer conversions are implicit conversions.
 		 */
-		status = acpi_ut_strtoul64(ACPI_CAST_PTR(char, pointer),
-					   (acpi_gbl_integer_byte_width |
-					    flags), &result);
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
+		if (implicit_conversion) {
+			result =
+			    acpi_ut_implicit_strtoul64(ACPI_CAST_PTR
+						       (char, pointer));
+		} else {
+			result =
+			    acpi_ut_explicit_strtoul64(ACPI_CAST_PTR
+						       (char, pointer));
 		}
 		break;
 
@@ -631,7 +637,7 @@ acpi_ex_convert_to_target_type(acpi_object_type destination_type,
 			 */
 			status =
 			    acpi_ex_convert_to_integer(source_desc, result_desc,
-						       ACPI_STRTOUL_BASE16);
+						       ACPI_IMPLICIT_CONVERSION);
 			break;
 
 		case ACPI_TYPE_STRING:
diff --git a/drivers/acpi/acpica/exmisc.c b/drivers/acpi/acpica/exmisc.c
index 1e7649c..dbad3eb 100644
--- a/drivers/acpi/acpica/exmisc.c
+++ b/drivers/acpi/acpica/exmisc.c
@@ -330,7 +330,7 @@ acpi_ex_do_logical_op(u16 opcode,
 	case ACPI_TYPE_INTEGER:
 
 		status = acpi_ex_convert_to_integer(operand1, &local_operand1,
-						    ACPI_STRTOUL_BASE16);
+						    ACPI_IMPLICIT_CONVERSION);
 		break;
 
 	case ACPI_TYPE_STRING:
diff --git a/drivers/acpi/acpica/exresop.c b/drivers/acpi/acpica/exresop.c
index c485242..1c7c996 100644
--- a/drivers/acpi/acpica/exresop.c
+++ b/drivers/acpi/acpica/exresop.c
@@ -415,7 +415,7 @@ acpi_ex_resolve_operands(u16 opcode,
 			 * Known as "Implicit Source Operand Conversion"
 			 */
 			status = acpi_ex_convert_to_integer(obj_desc, stack_ptr,
-							    ACPI_STRTOUL_BASE16);
+							    ACPI_IMPLICIT_CONVERSION);
 			if (ACPI_FAILURE(status)) {
 				if (status == AE_TYPE) {
 					ACPI_ERROR((AE_INFO,
diff --git a/drivers/acpi/acpica/nsconvert.c b/drivers/acpi/acpica/nsconvert.c
index e4a7da8..539d775 100644
--- a/drivers/acpi/acpica/nsconvert.c
+++ b/drivers/acpi/acpica/nsconvert.c
@@ -78,8 +78,8 @@ acpi_ns_convert_to_integer(union acpi_operand_object *original_object,
 
 		/* String-to-Integer conversion */
 
-		status = acpi_ut_strtoul64(original_object->string.pointer,
-					   acpi_gbl_integer_byte_width, &value);
+		status =
+		    acpi_ut_strtoul64(original_object->string.pointer, &value);
 		if (ACPI_FAILURE(status)) {
 			return (status);
 		}
diff --git a/drivers/acpi/acpica/utstrsuppt.c b/drivers/acpi/acpica/utstrsuppt.c
new file mode 100644
index 0000000..64a5fae
--- /dev/null
+++ b/drivers/acpi/acpica/utstrsuppt.c
@@ -0,0 +1,416 @@
+/*******************************************************************************
+ *
+ * Module Name: utstrsuppt - string-to-integer conversion support functions
+ *
+ ******************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2017, 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"
+
+#define _COMPONENT          ACPI_UTILITIES
+ACPI_MODULE_NAME("utstrsuppt")
+
+/* Local prototypes */
+static acpi_status
+acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit);
+
+static acpi_status
+acpi_ut_strtoul_multiply64(u64 multiplicand, u64 multiplier, u64 *out_product);
+
+static acpi_status
+acpi_ut_strtoul_add64(u64 addend1, u64 addend2, u64 *out_sum);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_convert_octal_string
+ *
+ * PARAMETERS:  string                  - Null terminated input string
+ *              return_value_ptr        - Where the converted value is returned
+ *
+ * RETURN:      Status and 64-bit converted integer
+ *
+ * DESCRIPTION: Performs a base 8 conversion of the input string to an
+ *              integer value, either 32 or 64 bits.
+ *
+ * NOTE:        Maximum 64-bit unsigned octal value is 01777777777777777777777
+ *              Maximum 32-bit unsigned octal value is 037777777777
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value_ptr)
+{
+	u64 accumulated_value = 0;
+	acpi_status status = AE_OK;
+
+	/* Convert each ASCII byte in the input string */
+
+	while (*string) {
+
+		/* Must be ASCII 0-7, otherwise terminate with no error */
+
+		if (!(ACPI_IS_OCTAL_DIGIT(*string))) {
+			break;
+		}
+
+		/* Convert and insert this octal digit into the accumulator */
+
+		status = acpi_ut_insert_digit(&accumulated_value, 8, *string);
+		if (ACPI_FAILURE(status)) {
+			status = AE_OCTAL_OVERFLOW;
+			break;
+		}
+
+		string++;
+	}
+
+	/* Always return the value that has been accumulated */
+
+	*return_value_ptr = accumulated_value;
+	return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_convert_decimal_string
+ *
+ * PARAMETERS:  string                  - Null terminated input string
+ *              return_value_ptr        - Where the converted value is returned
+ *
+ * RETURN:      Status and 64-bit converted integer
+ *
+ * DESCRIPTION: Performs a base 10 conversion of the input string to an
+ *              integer value, either 32 or 64 bits.
+ *
+ * NOTE:        Maximum 64-bit unsigned decimal value is 18446744073709551615
+ *              Maximum 32-bit unsigned decimal value is 4294967295
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr)
+{
+	u64 accumulated_value = 0;
+	acpi_status status = AE_OK;
+
+	/* Convert each ASCII byte in the input string */
+
+	while (*string) {
+
+		/* Must be ASCII 0-9, otherwise terminate with no error */
+
+		if (!isdigit(*string)) {
+			break;
+		}
+
+		/* Convert and insert this decimal digit into the accumulator */
+
+		status = acpi_ut_insert_digit(&accumulated_value, 10, *string);
+		if (ACPI_FAILURE(status)) {
+			status = AE_DECIMAL_OVERFLOW;
+			break;
+		}
+
+		string++;
+	}
+
+	/* Always return the value that has been accumulated */
+
+	*return_value_ptr = accumulated_value;
+	return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_convert_hex_string
+ *
+ * PARAMETERS:  string                  - Null terminated input string
+ *              return_value_ptr        - Where the converted value is returned
+ *
+ * RETURN:      Status and 64-bit converted integer
+ *
+ * DESCRIPTION: Performs a base 16 conversion of the input string to an
+ *              integer value, either 32 or 64 bits.
+ *
+ * NOTE:        Maximum 64-bit unsigned hex value is 0xFFFFFFFFFFFFFFFF
+ *              Maximum 32-bit unsigned hex value is 0xFFFFFFFF
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr)
+{
+	u64 accumulated_value = 0;
+	acpi_status status = AE_OK;
+
+	/* Convert each ASCII byte in the input string */
+
+	while (*string) {
+
+		/* Must be ASCII A-F, a-f, or 0-9, otherwise terminate with no error */
+
+		if (!isxdigit(*string)) {
+			break;
+		}
+
+		/* Convert and insert this hex digit into the accumulator */
+
+		status = acpi_ut_insert_digit(&accumulated_value, 16, *string);
+		if (ACPI_FAILURE(status)) {
+			status = AE_HEX_OVERFLOW;
+			break;
+		}
+
+		string++;
+	}
+
+	/* Always return the value that has been accumulated */
+
+	*return_value_ptr = accumulated_value;
+	return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_remove_leading_zeros
+ *
+ * PARAMETERS:  string                  - Pointer to input ASCII string
+ *
+ * RETURN:      Next character after the leading zeros. This behavior may be
+ *              Used by the caller to detect end-of-string.
+ *
+ * DESCRIPTION: Remove all leading zeros in the input string. Return the
+ *              next character after the final zero to check for the end
+ *              of the string (NULL terminator).
+ *
+ ******************************************************************************/
+
+char acpi_ut_remove_leading_zeros(char **string)
+{
+	/* Skip all leading zeros */
+
+	while (**string == ACPI_ASCII_ZERO) {
+		*string += 1;
+	}
+
+	return (**string);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_detect_hex_prefix
+ *
+ * PARAMETERS:  string                  - Pointer to input ASCII string
+ *
+ * RETURN:      TRUE if a 0x prefix was found
+ *
+ * DESCRIPTION: Detect and remove a hex 0x prefix
+ *
+ ******************************************************************************/
+
+u8 acpi_ut_detect_hex_prefix(char **string)
+{
+
+	if ((**string == ACPI_ASCII_ZERO) &&
+	    (tolower((int)*(*string + 1)) == 'x')) {
+		*string += 2;	/* Go past the leading 0x */
+		return (TRUE);
+	}
+
+	return (FALSE);		/* Not a hex string */
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_detect_octal_prefix
+ *
+ * PARAMETERS:  string                  - Pointer to input ASCII string
+ *
+ * RETURN:      True if an octal 0 prefix was found
+ *
+ * DESCRIPTION: Detect and remove an octal prefix (zero)
+ *
+ ******************************************************************************/
+
+u8 acpi_ut_detect_octal_prefix(char **string)
+{
+
+	if (**string == ACPI_ASCII_ZERO) {
+		*string += 1;	/* Go past the leading 0 */
+		return (TRUE);
+	}
+
+	return (FALSE);		/* Not an octal string */
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_insert_digit
+ *
+ * PARAMETERS:  accumulated_value       - Current value of the integer value
+ *                                        accumulator. The New value is
+ *                                        returned here.
+ *              base                    - Radix, either 8/10/16 supported
+ *              ascii_digit             - ASCII single digit to be inserted
+ *
+ * RETURN:      Status and result of convert/insert operation. The only
+ *              exception is numeric overflow of either the multiply or the
+ *              add operations.
+ *
+ * DESCRIPTION: Generic conversion and insertion function for all bases:
+ *
+ *              1) Multiply the current accumulated converted value by the
+ *              base in order to make room for the new character.
+ *
+ *              2) Add the current accumulated/converted value the new
+ *              character (after the character has been converted to a binary
+ *              value).
+ *
+ *              Note: The only possible exception indicates an integer
+ *              overflow (AE_NUMERIC_OVERFLOW)
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit)
+{
+	acpi_status status;
+	u64 product;
+
+	/* Make room in the accumulated value for the incoming digit */
+
+	status = acpi_ut_strtoul_multiply64(*accumulated_value, base, &product);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	/* Add in the new digit, and store to the caller's accumulated value */
+
+	status =
+	    acpi_ut_strtoul_add64(product,
+				  acpi_ut_ascii_char_to_hex(ascii_digit),
+				  accumulated_value);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_strtoul_multiply64
+ *
+ * PARAMETERS:  multiplicand            - Current accumulated converted integer
+ *              multiplier              - Base/Radix
+ *              out_product             - Where the product is returned
+ *
+ * RETURN:      Status and 64-bit product
+ *
+ * DESCRIPTION: Multiply two 64-bit values, with checking for 64-bit overflow as
+ *              well as 32-bit overflow if necessary (if the current global
+ *              integer width is 32).
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ut_strtoul_multiply64(u64 multiplicand, u64 multiplier, u64 *out_product)
+{
+	u64 product;
+
+	/* Exit if either operand is zero */
+
+	*out_product = 0;
+	if (!multiplicand || !multiplier) {
+		return (AE_OK);
+	}
+
+	/* Check for 64-bit overflow before the actual multiplication */
+
+	if (multiplicand > (ACPI_UINT64_MAX / multiplier)) {
+		return (AE_NUMERIC_OVERFLOW);
+	}
+
+	product = multiplicand * multiplier;
+
+	/* Check for 32-bit overflow if necessary */
+
+	if ((acpi_gbl_integer_bit_width == 32) && (product > ACPI_UINT32_MAX)) {
+		return (AE_NUMERIC_OVERFLOW);
+	}
+
+	*out_product = product;
+	return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_strtoul_add64
+ *
+ * PARAMETERS:  addend1                 - Current accumulated converted integer
+ *              addend2                 - New hex value/char
+ *              out_sum                 - Where sum is returned (Accumulator)
+ *
+ * RETURN:      Status and 64-bit sum
+ *
+ * DESCRIPTION: Add two 64-bit values, with checking for 64-bit overflow as
+ *              well as 32-bit overflow if necessary (if the current global
+ *              integer width is 32).
+ *
+ ******************************************************************************/
+
+static acpi_status acpi_ut_strtoul_add64(u64 addend1, u64 addend2, u64 *out_sum)
+{
+	u64 sum;
+
+	/* Check for 64-bit overflow before the actual addition */
+
+	if ((addend1 > 0) && (addend2 > (ACPI_UINT64_MAX - addend1))) {
+		return (AE_NUMERIC_OVERFLOW);
+	}
+
+	sum = addend1 + addend2;
+
+	/* Check for 32-bit overflow if necessary */
+
+	if ((acpi_gbl_integer_bit_width == 32) && (sum > ACPI_UINT32_MAX)) {
+		return (AE_NUMERIC_OVERFLOW);
+	}
+
+	*out_sum = sum;
+	return (AE_OK);
+}
diff --git a/drivers/acpi/acpica/utstrtoul64.c b/drivers/acpi/acpica/utstrtoul64.c
index 9633ee1..e5a2df3 100644
--- a/drivers/acpi/acpica/utstrtoul64.c
+++ b/drivers/acpi/acpica/utstrtoul64.c
@@ -1,6 +1,7 @@
 /*******************************************************************************
  *
- * Module Name: utstrtoul64 - string to 64-bit integer support
+ * Module Name: utstrtoul64 - string-to-integer support for both 64-bit
+ *                            and 32-bit integers
  *
  ******************************************************************************/
 
@@ -44,152 +45,74 @@
 #include <acpi/acpi.h>
 #include "accommon.h"
 
-/*******************************************************************************
- *
- * The functions in this module satisfy the need for 64-bit string-to-integer
- * conversions on both 32-bit and 64-bit platforms.
- *
- ******************************************************************************/
-
 #define _COMPONENT          ACPI_UTILITIES
 ACPI_MODULE_NAME("utstrtoul64")
 
-/* Local prototypes */
-static u64 acpi_ut_strtoul_base10(char *string, u32 flags);
-
-static u64 acpi_ut_strtoul_base16(char *string, u32 flags);
-
 /*******************************************************************************
  *
- * String conversion rules as written in the ACPI specification. The error
- * conditions and behavior are different depending on the type of conversion.
- *
+ * This module contains the external string to 64/32-bit unsigned integer
+ * conversion functions:
  *
- * Implicit data type conversion: string-to-integer
- * --------------------------------------------------
- *
- * Base is always 16. This is the ACPI_STRTOUL_BASE16 case.
- *
- * Example:
- *      Add ("BA98", Arg0, Local0)
- *
- * The integer is initialized to the value zero.
- * The ASCII string is interpreted as a hexadecimal constant.
- *
- *  1)  A "0x" prefix is not allowed. However, ACPICA allows this for
- *      compatibility with previous ACPICA. (NO ERROR)
- *
- *  2)  Terminates when the size of an integer is reached (32 or 64 bits).
- *      (NO ERROR)
+ *  1) Standard strtoul() function with 64-bit support. This is mostly used by
+ *      the iASL compiler.
+ *  2) Runtime "Explicit conversion" as defined in the ACPI specification.
+ *  3) Runtime "Implicit conversion" as defined in the ACPI specification.
  *
- *  3)  The first non-hex character terminates the conversion without error.
- *      (NO ERROR)
+ * Current users of this module:
  *
- *  4)  Conversion of a null (zero-length) string to an integer is not
- *      allowed. However, ACPICA allows this for compatibility with previous
- *      ACPICA. This conversion returns the value 0. (NO ERROR)
- *
- *
- * Explicit data type conversion:  to_integer() with string operand
- * ---------------------------------------------------------------
- *
- * Base is either 10 (default) or 16 (with 0x prefix)
- *
- * Examples:
- *      to_integer ("1000")
- *      to_integer ("0xABCD")
- *
- *  1)  Can be (must be) either a decimal or hexadecimal numeric string.
- *      A hex value must be prefixed by "0x" or it is interpreted as a decimal.
+ *  interpreter - Implicit and explicit conversions, GPE method names
+ *  debugger    - Command line input string conversion
+ *  iASL        - Main parser, conversion of constants to integers
+ *  iASL        - Data Table Compiler parser (constant math expressions)
+ *  iASL        - Preprocessor (constant math expressions)
+ *  acpi_dump   - Input table addresses
+ *  acpi_exec   - Testing of the acpi_ut_strtoul64 function
  *
- *  2)  The value must not exceed the maximum of an integer value. ACPI spec
- *      states the behavior is "unpredictable", so ACPICA matches the behavior
- *      of the implicit conversion case.(NO ERROR)
+ * Notes concerning users of these interfaces:
  *
- *  3)  Behavior on the first non-hex character is not specified by the ACPI
- *      spec, so ACPICA matches the behavior of the implicit conversion case
- *      and terminates. (NO ERROR)
+ *  acpi_gbl_integer_byte_width is used to set the 32/64 bit limit. This global
+ *  must be set to the proper width. For the core ACPICA code, the width
+ *  depends on the DSDT version. For iASL, the default width is 64 bits for
+ *  all parsers, but error checking is performed later to flag cases where
+ *  a 64-bit constant is wrongly defined in a 32-bit DSDT/SSDT.
  *
- *  4)  A null (zero-length) string is illegal.
- *      However, ACPICA allows this for compatibility with previous ACPICA.
- *      This conversion returns the value 0. (NO ERROR)
+ *  In ACPI, the only place where octal numbers are supported is within
+ *  the ASL language itself. There is no runtime support for octal.
  *
  ******************************************************************************/
-
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ut_strtoul64
  *
- * PARAMETERS:  string                  - Null terminated input string
- *              flags                   - Conversion info, see below
+ * PARAMETERS:  string                  - Null terminated input string.
+ *                                        Must be a valid pointer
  *              return_value            - Where the converted integer is
- *                                        returned
- *
- * RETURN:      Status and Converted value
- *
- * DESCRIPTION: Convert a string into an unsigned value. Performs either a
- *              32-bit or 64-bit conversion, depending on the input integer
- *              size in Flags (often the current mode of the interpreter).
- *
- * Values for Flags:
- *      ACPI_STRTOUL_32BIT      - Max integer value is 32 bits
- *      ACPI_STRTOUL_64BIT      - Max integer value is 64 bits
- *      ACPI_STRTOUL_BASE16     - Input string is hexadecimal. Default
- *                                is 10/16 based on string prefix (0x).
+ *                                        returned. Must be a valid pointer
  *
- * NOTES:
- *   Negative numbers are not supported, as they are not supported by ACPI.
+ * RETURN:      Status and converted integer
+ *              Returns an exception on numeric overflow
  *
- *   Supports only base 16 or base 10 strings/values. Does not
- *   support Octal strings, as these are not supported by ACPI.
+ * DESCRIPTION: Convert a string into an unsigned integer. Performs either a
+ *              32-bit or 64-bit conversion, depending on the current global
+ *              integer width. Supports Decimal, Hex, and Octal strings.
  *
- * Current users of this support:
+ * Current users of this function:
  *
- *  interpreter - Implicit and explicit conversions, GPE method names
- *  debugger    - Command line input string conversion
- *  iASL        - Main parser, conversion of constants to integers
- *  iASL        - Data Table Compiler parser (constant math expressions)
  *  iASL        - Preprocessor (constant math expressions)
- *  acpi_dump   - Input table addresses
- *  acpi_exec   - Testing of the acpi_ut_strtoul64 function
- *
- * Note concerning callers:
- *   acpi_gbl_integer_byte_width can be used to set the 32/64 limit. If used,
- *   this global should be set to the proper width. For the core ACPICA code,
- *   this width depends on the DSDT version. For iASL, the default byte
- *   width is always 8 for the parser, but error checking is performed later
- *   to flag cases where a 64-bit constant is defined in a 32-bit DSDT/SSDT.
+ *  iASL        - Main parser, conversion of ASL constants to integers
+ *  iASL        - Data Table Compiler parser (constant math expressions)
  *
  ******************************************************************************/
-
-acpi_status acpi_ut_strtoul64(char *string, u32 flags, u64 *return_value)
+acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
 {
 	acpi_status status = AE_OK;
-	u32 base;
+	u32 base = 10;		/* Default is decimal */
 
 	ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string);
 
-	/* Parameter validation */
-
-	if (!string || !return_value) {
-		return_ACPI_STATUS(AE_BAD_PARAMETER);
-	}
-
 	*return_value = 0;
 
-	/* Check for zero-length string, returns 0 */
-
-	if (*string == 0) {
-		return_ACPI_STATUS(AE_OK);
-	}
-
-	/* Skip over any white space at start of string */
-
-	while (isspace((int)*string)) {
-		string++;
-	}
-
-	/* End of string? return 0 */
+	/* Null return string returns a value of zero */
 
 	if (*string == 0) {
 		return_ACPI_STATUS(AE_OK);
@@ -198,45 +121,45 @@ acpi_status acpi_ut_strtoul64(char *string, u32 flags, u64 *return_value)
 	/*
 	 * 1) The "0x" prefix indicates base 16. Per the ACPI specification,
 	 * the "0x" prefix is only allowed for implicit (non-strict) conversions.
-	 * However, we always allow it for compatibility with older ACPICA.
+	 * However, we always allow it for compatibility with older ACPICA and
+	 * just plain on principle.
 	 */
-	if ((*string == ACPI_ASCII_ZERO) &&
-	    (tolower((int)*(string + 1)) == 'x')) {
-		string += 2;	/* Go past the 0x */
-		if (*string == 0) {
-			return_ACPI_STATUS(AE_OK);	/* Return value 0 */
-		}
-
-		base = 16;
-	}
-
-	/* 2) Force to base 16 (implicit conversion case) */
-
-	else if (flags & ACPI_STRTOUL_BASE16) {
+	if (acpi_ut_detect_hex_prefix(&string)) {
 		base = 16;
 	}
 
-	/* 3) Default fallback is to Base 10 */
-
-	else {
-		base = 10;
+	/*
+	 * 2) Check for an octal constant, defined to be a leading zero
+	 * followed by an valid octal digit (0-7)
+	 */
+	else if (acpi_ut_detect_octal_prefix(&string)) {
+		base = 8;
 	}
 
-	/* Skip all leading zeros */
-
-	while (*string == ACPI_ASCII_ZERO) {
-		string++;
-		if (*string == 0) {
-			return_ACPI_STATUS(AE_OK);	/* Return value 0 */
-		}
+	if (!acpi_ut_remove_leading_zeros(&string)) {
+		return_ACPI_STATUS(AE_OK);	/* Return value 0 */
 	}
 
-	/* Perform the base 16 or 10 conversion */
-
-	if (base == 16) {
-		*return_value = acpi_ut_strtoul_base16(string, flags);
-	} else {
-		*return_value = acpi_ut_strtoul_base10(string, flags);
+	/*
+	 * Perform the base 8, 10, or 16 conversion. A numeric overflow will
+	 * return an exception.
+	 */
+	switch (base) {
+	case 8:
+		status = acpi_ut_convert_octal_string(string, return_value);
+		break;
+
+	case 10:
+		status = acpi_ut_convert_decimal_string(string, return_value);
+		break;
+
+	case 16:
+		status = acpi_ut_convert_hex_string(string, return_value);
+		break;
+
+	default:
+		status = AE_AML_INTERNAL;	/* Should never happen */
+		break;
 	}
 
 	return_ACPI_STATUS(status);
@@ -244,104 +167,167 @@ acpi_status acpi_ut_strtoul64(char *string, u32 flags, u64 *return_value)
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ut_strtoul_base10
+ * FUNCTION:    acpi_ut_implicit_strtoul64
+ *
+ * PARAMETERS:  string                  - Null terminated input string.
+ *                                        Must be a valid pointer
  *
- * PARAMETERS:  string                  - Null terminated input string
- *              flags                   - Conversion info
+ * RETURN:      Converted integer
  *
- * RETURN:      64-bit converted integer
+ * DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon
+ *              an "implicit conversion" by the ACPI specification. Used by
+ *              many ASL operators that require an integer operand, and support
+ *              an automatic (implicit) conversion from a string operand
+ *              to the final integer operand. The restriction is that only
+ *              hex strings are supported.
  *
- * DESCRIPTION: Performs a base 10 conversion of the input string to an
- *              integer value, either 32 or 64 bits.
- *              Note: String must be valid and non-null.
+ * -----------------------------------------------------------------------------
+ *
+ * Base is always 16, either with or without the 0x prefix.
+ *
+ * Examples (both are hex values):
+ *      Add ("BA98", Arg0, Local0)
+ *      Subtract ("0x12345678", Arg1, Local1)
+ *
+ * Rules extracted from the ACPI specification:
+ *
+ *  The converted integer is initialized to the value zero.
+ *  The ASCII string is interpreted as a hexadecimal constant.
+ *
+ *  1)  A "0x" prefix is not allowed. However, ACPICA allows this as an
+ *      ACPI extension on general principle. (NO ERROR)
+ *
+ *  2)  Terminates when the size of an integer is reached (32 or 64 bits).
+ *      There are no numeric overflow conditions. (NO ERROR)
+ *
+ *  3)  The first non-hex character terminates the conversion and returns
+ *      the current accumulated value of the converted integer (NO ERROR).
+ *
+ *  4)  Conversion of a null (zero-length) string to an integer is
+ *      technically allowed. However, ACPICA allows as an ACPI extension.
+ *      The conversion returns the value 0. (NO ERROR)
+ *
+ * Note: there are no error conditions returned by this function. At
+ * the minimum, a value of zero is returned.
+ *
+ * Current users of this function:
+ *
+ *  interpreter - All runtime implicit conversions, as per ACPI specification
+ *  iASL        - Data Table Compiler parser (constant math expressions)
  *
  ******************************************************************************/
 
-static u64 acpi_ut_strtoul_base10(char *string, u32 flags)
+u64 acpi_ut_implicit_strtoul64(char *string)
 {
-	int ascii_digit;
-	u64 next_value;
-	u64 return_value = 0;
+	u64 converted_integer = 0;
 
-	/* Main loop: convert each ASCII byte in the input string */
+	ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string);
 
-	while (*string) {
-		ascii_digit = *string;
-		if (!isdigit(ascii_digit)) {
-
-			/* Not ASCII 0-9, terminate */
-
-			goto exit;
-		}
-
-		/* Convert and insert (add) the decimal digit */
-
-		acpi_ut_short_multiply(return_value, 10, &next_value);
-		next_value += (ascii_digit - ACPI_ASCII_ZERO);
-
-		/* Check for overflow (32 or 64 bit) - return current converted value */
-
-		if (((flags & ACPI_STRTOUL_32BIT) && (next_value > ACPI_UINT32_MAX)) || (next_value < return_value)) {	/* 64-bit overflow case */
-			goto exit;
-		}
+	/*
+	 * Per the ACPI specification, only hexadecimal is supported for
+	 * implicit conversions, and the "0x" prefix is "not allowed".
+	 * However, allow a "0x" prefix as an ACPI extension.
+	 */
+	acpi_ut_detect_hex_prefix(&string);
 
-		return_value = next_value;
-		string++;
+	if (!acpi_ut_remove_leading_zeros(&string)) {
+		return_VALUE(0);
 	}
 
-exit:
-	return (return_value);
+	/*
+	 * Ignore overflow as per the ACPI specification. This is implemented by
+	 * ignoring the return status below. On overflow, the input string is
+	 * simply truncated.
+	 */
+	acpi_ut_convert_hex_string(string, &converted_integer);
+	return_VALUE(converted_integer);
 }
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ut_strtoul_base16
+ * FUNCTION:    acpi_ut_explicit_strtoul64
+ *
+ * PARAMETERS:  string                  - Null terminated input string.
+ *                                        Must be a valid pointer
+ *
+ * RETURN:      Converted integer
+ *
+ * DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon
+ *              an "explicit conversion" by the ACPI specification. The
+ *              main restriction is that only hex and decimal are supported.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Base is either 10 (default) or 16 (with 0x prefix). There is no octal
+ * (base 8), as per the ACPI specification.
+ *
+ * Examples:
+ *      to_integer ("1000")     Decimal
+ *      to_integer ("0xABCD")   Hex
+ *
+ * Rules extracted from the ACPI specification:
+ *
+ *  1)  Thi input string is either a decimal or hexadecimal numeric string.
+ *      A hex value must be prefixed by "0x" or it is interpreted as decimal.
+ *
+ *  2)  The value must not exceed the maximum of an integer value
+ *      (32 or 64 bits). The ACPI specification states the behavior is
+ *      "unpredictable", so ACPICA matches the behavior of the implicit
+ *      conversion case. There are no numeric overflow conditions. (NO ERROR)
+ *
+ *  3)  Behavior on the first non-hex character is not specified by the ACPI
+ *      specification (for the to_integer operator), so ACPICA matches the
+ *      behavior of the implicit conversion case. It terminates the
+ *      conversion and returns the current accumulated value of the converted
+ *      integer. (NO ERROR)
  *
- * PARAMETERS:  string                  - Null terminated input string
- *              flags                   - conversion info
+ *  4)  Conversion of a null (zero-length) string to an integer is
+ *      technically allowed. However, ACPICA allows as an ACPI extension.
+ *      The conversion returns the value 0. (NO ERROR)
  *
- * RETURN:      64-bit converted integer
+ * Note: there are no error conditions returned by this function. At
+ * the minimum, a value of zero is returned.
  *
- * DESCRIPTION: Performs a base 16 conversion of the input string to an
- *              integer value, either 32 or 64 bits.
- *              Note: String must be valid and non-null.
+ * Current users of this function:
+ *
+ *  interpreter - Runtime ASL to_integer operator, as per the ACPI specification
  *
  ******************************************************************************/
 
-static u64 acpi_ut_strtoul_base16(char *string, u32 flags)
+u64 acpi_ut_explicit_strtoul64(char *string)
 {
-	int ascii_digit;
-	u32 valid_digits = 1;
-	u64 return_value = 0;
-
-	/* Main loop: convert each ASCII byte in the input string */
-
-	while (*string) {
-
-		/* Check for overflow (32 or 64 bit) - return current converted value */
-
-		if ((valid_digits > 16) ||
-		    ((valid_digits > 8) && (flags & ACPI_STRTOUL_32BIT))) {
-			goto exit;
-		}
-
-		ascii_digit = *string;
-		if (!isxdigit(ascii_digit)) {
-
-			/* Not Hex ASCII A-F, a-f, or 0-9, terminate */
+	u64 converted_integer = 0;
+	u32 base = 10;		/* Default is decimal */
 
-			goto exit;
-		}
+	ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string);
 
-		/* Convert and insert the hex digit */
+	/*
+	 * Only Hex and Decimal are supported, as per the ACPI specification.
+	 * 0x prefix means hex; otherwise decimal is assumed.
+	 */
+	if (acpi_ut_detect_hex_prefix(&string)) {
+		base = 16;
+	}
 
-		acpi_ut_short_shift_left(return_value, 4, &return_value);
-		return_value |= acpi_ut_ascii_char_to_hex(ascii_digit);
+	if (!acpi_ut_remove_leading_zeros(&string)) {
+		return_VALUE(0);
+	}
 
-		string++;
-		valid_digits++;
+	/*
+	 * Ignore overflow as per the ACPI specification. This is implemented by
+	 * ignoring the return status below. On overflow, the input string is
+	 * simply truncated.
+	 */
+	switch (base) {
+	case 10:
+	default:
+		acpi_ut_convert_decimal_string(string, &converted_integer);
+		break;
+
+	case 16:
+		acpi_ut_convert_hex_string(string, &converted_integer);
+		break;
 	}
 
-exit:
-	return (return_value);
+	return_VALUE(converted_integer);
 }
diff --git a/include/acpi/acexcep.h b/include/acpi/acexcep.h
index ad54610..17d61b1 100644
--- a/include/acpi/acexcep.h
+++ b/include/acpi/acexcep.h
@@ -126,8 +126,12 @@ struct acpi_exception_info {
 #define AE_NOT_CONFIGURED               EXCEP_ENV (0x001C)
 #define AE_ACCESS                       EXCEP_ENV (0x001D)
 #define AE_IO_ERROR                     EXCEP_ENV (0x001E)
+#define AE_NUMERIC_OVERFLOW             EXCEP_ENV (0x001F)
+#define AE_HEX_OVERFLOW                 EXCEP_ENV (0x0020)
+#define AE_DECIMAL_OVERFLOW             EXCEP_ENV (0x0021)
+#define AE_OCTAL_OVERFLOW               EXCEP_ENV (0x0022)
 
-#define AE_CODE_ENV_MAX                 0x001E
+#define AE_CODE_ENV_MAX                 0x0022
 
 /*
  * Programmer exceptions
@@ -263,7 +267,15 @@ static const struct acpi_exception_info acpi_gbl_exception_names_env[] = {
 	EXCEP_TXT("AE_NOT_CONFIGURED",
 		  "The interface is not part of the current subsystem configuration"),
 	EXCEP_TXT("AE_ACCESS", "Permission denied for the requested operation"),
-	EXCEP_TXT("AE_IO_ERROR", "An I/O error occurred")
+	EXCEP_TXT("AE_IO_ERROR", "An I/O error occurred"),
+	EXCEP_TXT("AE_NUMERIC_OVERFLOW",
+		  "Overflow during string-to-integer conversion"),
+	EXCEP_TXT("AE_HEX_OVERFLOW",
+		  "Overflow during ASCII hex-to-binary conversion"),
+	EXCEP_TXT("AE_DECIMAL_OVERFLOW",
+		  "Overflow during ASCII decimal-to-binary conversion"),
+	EXCEP_TXT("AE_OCTAL_OVERFLOW",
+		  "Overflow during ASCII octal-to-binary conversion")
 };
 
 static const struct acpi_exception_info acpi_gbl_exception_names_pgm[] = {
diff --git a/tools/power/acpi/tools/acpidump/Makefile b/tools/power/acpi/tools/acpidump/Makefile
index f7c7af1..b436f86 100644
--- a/tools/power/acpi/tools/acpidump/Makefile
+++ b/tools/power/acpi/tools/acpidump/Makefile
@@ -39,6 +39,7 @@ TOOL_OBJS = \
 	utnonansi.o\
 	utprint.o\
 	utstring.o\
+	utstrsuppt.o\
 	utstrtoul64.o\
 	utxferror.o\
 	oslinuxtbl.o\
diff --git a/tools/power/acpi/tools/acpidump/apdump.c b/tools/power/acpi/tools/acpidump/apdump.c
index 60df1fb..0634449 100644
--- a/tools/power/acpi/tools/acpidump/apdump.c
+++ b/tools/power/acpi/tools/acpidump/apdump.c
@@ -287,8 +287,7 @@ int ap_dump_table_by_address(char *ascii_address)
 
 	/* Convert argument to an integer physical address */
 
-	status = acpi_ut_strtoul64(ascii_address, ACPI_STRTOUL_64BIT,
-				   &long_address);
+	status = acpi_ut_strtoul64(ascii_address, &long_address);
 	if (ACPI_FAILURE(status)) {
 		fprintf(stderr, "%s: Could not convert to a physical address\n",
 			ascii_address);
diff --git a/tools/power/acpi/tools/acpidump/apmain.c b/tools/power/acpi/tools/acpidump/apmain.c
index 943b6b6..22c3b4e 100644
--- a/tools/power/acpi/tools/acpidump/apmain.c
+++ b/tools/power/acpi/tools/acpidump/apmain.c
@@ -208,9 +208,7 @@ static int ap_do_options(int argc, char **argv)
 		case 'r':	/* Dump tables from specified RSDP */
 
 			status =
-			    acpi_ut_strtoul64(acpi_gbl_optarg,
-					      ACPI_STRTOUL_64BIT,
-					      &gbl_rsdp_base);
+			    acpi_ut_strtoul64(acpi_gbl_optarg, &gbl_rsdp_base);
 			if (ACPI_FAILURE(status)) {
 				fprintf(stderr,
 					"%s: Could not convert to a physical address\n",
