ACPICA: Utilities: Reorder initialization code

ACPICA commit 3894fa9d071343e6ebc7ea480255fa4f27a290be

This patch re-orders initialization code in acpi_enable_subsystem()
so that all hardware reduced stuffs can be collected together.

Note this patch contains code from the following 2 ACPICA upstream commits
so that the changes can be made clearer for the reviewers:
 https://github.com/acpica/acpica/commit/071eff73
 https://github.com/acpica/acpica/commit/3894fa9d
And additional change to remove the global variable and unused code
fragments due to the test result. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/3894fa9dSigned-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/utxfinit.c

@@ -154,6 +154,21 @@ acpi_status __init acpi_enable_subsystem(u32 flags)
 	 */
 	acpi_gbl_early_initialization = FALSE;
 
+	/*
+	 * Install the default operation region handlers. These are the
+	 * handlers that are defined by the ACPI specification to be
+	 * "always accessible" -- namely, system_memory, system_IO, and
+	 * PCI_Config. This also means that no _REG methods need to be
+	 * run for these address spaces. We need to have these handlers
+	 * installed before any AML code can be executed, especially any
+	 * module-level code (11/2015).
+	 */
+	status = acpi_ev_install_region_handlers();
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status,
+				"During Region initialization"));
+		return_ACPI_STATUS(status);
+	}
 #if (!ACPI_REDUCED_HARDWARE)
 
 	/* Enable ACPI mode */
@@ -182,23 +197,7 @@ acpi_status __init acpi_enable_subsystem(u32 flags)
 			return_ACPI_STATUS(status);
 		}
 	}
-#endif				/* !ACPI_REDUCED_HARDWARE */
 
-	/*
-	 * Install the default op_region handlers. These are installed unless
-	 * other handlers have already been installed via the
-	 * install_address_space_handler interface.
-	 */
-	if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
-		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
-				  "[Init] Installing default address space handlers\n"));
-
-		status = acpi_ev_install_region_handlers();
-		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
-		}
-	}
-#if (!ACPI_REDUCED_HARDWARE)
 	/*
 	 * Initialize ACPI Event handling (Fixed and General Purpose)
 	 *