diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 9829979..4ead85f 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -80,7 +80,7 @@
 
 	/* Write the reset value to the reset register */
 
-	status = acpi_write(acpi_gbl_FADT.reset_value, reset_reg);
+	status = acpi_hw_write(acpi_gbl_FADT.reset_value, reset_reg);
 	return_ACPI_STATUS(status);
 }
 
@@ -97,67 +97,92 @@
  *
  * DESCRIPTION: Read from either memory or IO space.
  *
+ * LIMITATIONS: <These limitations also apply to acpi_write>
+ *      bit_width must be exactly 8, 16, 32, or 64.
+ *      space_iD must be system_memory or system_iO.
+ *      bit_offset and access_width are currently ignored, as there has
+ *          not been a need to implement these.
+ *
  ******************************************************************************/
-acpi_status acpi_read(u32 *value, struct acpi_generic_address *reg)
+acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg)
 {
+	u32 value;
 	u32 width;
 	u64 address;
 	acpi_status status;
 
 	ACPI_FUNCTION_NAME(acpi_read);
 
-	/*
-	 * Must have a valid pointer to a GAS structure, and a non-zero address
-	 * within.
-	 */
-	if (!reg) {
+	if (!return_value) {
 		return (AE_BAD_PARAMETER);
 	}
 
-	/* Get a local copy of the address. Handles possible alignment issues */
+	/* Validate contents of the GAS register. Allow 64-bit transfers */
 
-	ACPI_MOVE_64_TO_64(&address, &reg->address);
-	if (!address) {
-		return (AE_BAD_ADDRESS);
+	status = acpi_hw_validate_register(reg, 64, &address);
+	if (ACPI_FAILURE(status)) {
+		return (status);
 	}
 
-	/* Supported widths are 8/16/32 */
-
 	width = reg->bit_width;
-	if ((width != 8) && (width != 16) && (width != 32)) {
-		return (AE_SUPPORT);
+	if (width == 64) {
+		width = 32;	/* Break into two 32-bit transfers */
 	}
 
-	/* Initialize entire 32-bit return value to zero */
+	/* Initialize entire 64-bit return value to zero */
 
-	*value = 0;
+	*return_value = 0;
+	value = 0;
 
 	/*
 	 * Two address spaces supported: Memory or IO. PCI_Config is
 	 * not supported here because the GAS structure is insufficient
 	 */
-	switch (reg->space_id) {
-	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
+	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+		status = acpi_os_read_memory((acpi_physical_address)
+					     address, &value, width);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+		*return_value = value;
 
-		status = acpi_os_read_memory((acpi_physical_address) address,
-					     value, width);
-		break;
+		if (reg->bit_width == 64) {
 
-	case ACPI_ADR_SPACE_SYSTEM_IO:
+			/* Read the top 32 bits */
 
-		status =
-		    acpi_hw_read_port((acpi_io_address) address, value, width);
-		break;
+			status = acpi_os_read_memory((acpi_physical_address)
+						     (address + 4), &value, 32);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+			*return_value |= ((u64)value << 32);
+		}
+	} else {		/* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
 
-	default:
-		ACPI_ERROR((AE_INFO,
-			    "Unsupported address space: %X", reg->space_id));
-		return (AE_BAD_PARAMETER);
+		status = acpi_hw_read_port((acpi_io_address)
+					   address, &value, width);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
+		*return_value = value;
+
+		if (reg->bit_width == 64) {
+
+			/* Read the top 32 bits */
+
+			status = acpi_hw_read_port((acpi_io_address)
+						   (address + 4), &value, 32);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+			*return_value |= ((u64)value << 32);
+		}
 	}
 
 	ACPI_DEBUG_PRINT((ACPI_DB_IO,
-			  "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",
-			  *value, width, ACPI_FORMAT_UINT64(address),
+			  "Read:  %8.8X%8.8X width %2d from %8.8X%8.8X (%s)\n",
+			  ACPI_FORMAT_UINT64(*return_value), reg->bit_width,
+			  ACPI_FORMAT_UINT64(address),
 			  acpi_ut_get_region_name(reg->space_id)));
 
 	return (status);
@@ -169,7 +194,7 @@
  *
  * FUNCTION:    acpi_write
  *
- * PARAMETERS:  Value               - To be written
+ * PARAMETERS:  Value               - Value to be written
  *              Reg                 - GAS register structure
  *
  * RETURN:      Status
@@ -177,7 +202,7 @@
  * DESCRIPTION: Write to either memory or IO space.
  *
  ******************************************************************************/
-acpi_status acpi_write(u32 value, struct acpi_generic_address *reg)
+acpi_status acpi_write(u64 value, struct acpi_generic_address *reg)
 {
 	u32 width;
 	u64 address;
@@ -185,54 +210,61 @@
 
 	ACPI_FUNCTION_NAME(acpi_write);
 
-	/*
-	 * Must have a valid pointer to a GAS structure, and a non-zero address
-	 * within.
-	 */
-	if (!reg) {
-		return (AE_BAD_PARAMETER);
+	/* Validate contents of the GAS register. Allow 64-bit transfers */
+
+	status = acpi_hw_validate_register(reg, 64, &address);
+	if (ACPI_FAILURE(status)) {
+		return (status);
 	}
 
-	/* Get a local copy of the address. Handles possible alignment issues */
-
-	ACPI_MOVE_64_TO_64(&address, &reg->address);
-	if (!address) {
-		return (AE_BAD_ADDRESS);
-	}
-
-	/* Supported widths are 8/16/32 */
-
 	width = reg->bit_width;
-	if ((width != 8) && (width != 16) && (width != 32)) {
-		return (AE_SUPPORT);
+	if (width == 64) {
+		width = 32;	/* Break into two 32-bit transfers */
 	}
 
 	/*
-	 * Two address spaces supported: Memory or IO.
-	 * PCI_Config is not supported here because the GAS struct is insufficient
+	 * Two address spaces supported: Memory or IO. PCI_Config is
+	 * not supported here because the GAS structure is insufficient
 	 */
-	switch (reg->space_id) {
-	case ACPI_ADR_SPACE_SYSTEM_MEMORY:
+	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+		status = acpi_os_write_memory((acpi_physical_address)
+					      address, ACPI_LODWORD(value),
+					      width);
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
 
-		status = acpi_os_write_memory((acpi_physical_address) address,
-					      value, width);
-		break;
+		if (reg->bit_width == 64) {
+			status = acpi_os_write_memory((acpi_physical_address)
+						      (address + 4),
+						      ACPI_HIDWORD(value), 32);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+		}
+	} else {		/* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
 
-	case ACPI_ADR_SPACE_SYSTEM_IO:
-
-		status = acpi_hw_write_port((acpi_io_address) address, value,
+		status = acpi_hw_write_port((acpi_io_address)
+					    address, ACPI_LODWORD(value),
 					    width);
-		break;
+		if (ACPI_FAILURE(status)) {
+			return (status);
+		}
 
-	default:
-		ACPI_ERROR((AE_INFO,
-			    "Unsupported address space: %X", reg->space_id));
-		return (AE_BAD_PARAMETER);
+		if (reg->bit_width == 64) {
+			status = acpi_hw_write_port((acpi_io_address)
+						    (address + 4),
+						    ACPI_HIDWORD(value), 32);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+		}
 	}
 
 	ACPI_DEBUG_PRINT((ACPI_DB_IO,
-			  "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",
-			  value, width, ACPI_FORMAT_UINT64(address),
+			  "Wrote: %8.8X%8.8X width %2d   to %8.8X%8.8X (%s)\n",
+			  ACPI_FORMAT_UINT64(value), reg->bit_width,
+			  ACPI_FORMAT_UINT64(address),
 			  acpi_ut_get_region_name(reg->space_id)));
 
 	return (status);