ACPICA: Split acpi_format_exception into two parts

Split acpi_format_exception into two parts. New
function is acpi_ut_verify_exception and will be used to
verify exception codes returned by user.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c
index 36d8815..e437bc7 100644
--- a/drivers/acpi/utilities/utmisc.c
+++ b/drivers/acpi/utilities/utmisc.c
@@ -51,6 +51,78 @@
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ut_validate_exception
+ *
+ * PARAMETERS:  Status       - The acpi_status code to be formatted
+ *
+ * RETURN:      A string containing the exception text. NULL if exception is
+ *              not valid.
+ *
+ * DESCRIPTION: This function validates and translates an ACPI exception into
+ *              an ASCII string.
+ *
+ ******************************************************************************/
+const char *acpi_ut_validate_exception(acpi_status status)
+{
+	acpi_status sub_status;
+	const char *exception = NULL;
+
+	ACPI_FUNCTION_ENTRY();
+
+	/*
+	 * Status is composed of two parts, a "type" and an actual code
+	 */
+	sub_status = (status & ~AE_CODE_MASK);
+
+	switch (status & AE_CODE_MASK) {
+	case AE_CODE_ENVIRONMENTAL:
+
+		if (sub_status <= AE_CODE_ENV_MAX) {
+			exception = acpi_gbl_exception_names_env[sub_status];
+		}
+		break;
+
+	case AE_CODE_PROGRAMMER:
+
+		if (sub_status <= AE_CODE_PGM_MAX) {
+			exception =
+			    acpi_gbl_exception_names_pgm[sub_status - 1];
+		}
+		break;
+
+	case AE_CODE_ACPI_TABLES:
+
+		if (sub_status <= AE_CODE_TBL_MAX) {
+			exception =
+			    acpi_gbl_exception_names_tbl[sub_status - 1];
+		}
+		break;
+
+	case AE_CODE_AML:
+
+		if (sub_status <= AE_CODE_AML_MAX) {
+			exception =
+			    acpi_gbl_exception_names_aml[sub_status - 1];
+		}
+		break;
+
+	case AE_CODE_CONTROL:
+
+		if (sub_status <= AE_CODE_CTRL_MAX) {
+			exception =
+			    acpi_gbl_exception_names_ctrl[sub_status - 1];
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	return (ACPI_CAST_PTR(const char, exception));
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_ut_is_aml_table
  *
  * PARAMETERS:  Table               - An ACPI table
@@ -62,6 +134,7 @@
  *              data tables that do not contain AML code.
  *
  ******************************************************************************/
+
 u8 acpi_ut_is_aml_table(struct acpi_table_header *table)
 {