ACPICA: Re-implement interpreters' "serialized mode"

Enhanced the implementation of the interpreters'
serialized mode (boot with "acpi_serialize" to set
acpi_glb_all_methods_serialized flag.)
When this mode is specified, instead of creating a serialization
semaphore per control method, the interpreter lock is
simply no longer released before a blocking operation
during control method execution. This effectively makes
the AML Interpreter single-threaded. The overhead of a
semaphore per-method is eliminated.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/acpi/namespace/nsxfeval.c b/drivers/acpi/namespace/nsxfeval.c
index dca6799ac678..6a0a46eda9a2 100644
--- a/drivers/acpi/namespace/nsxfeval.c
+++ b/drivers/acpi/namespace/nsxfeval.c
@@ -170,7 +170,6 @@ acpi_evaluate_object(acpi_handle handle,
                      struct acpi_buffer *return_buffer)
 {
         acpi_status status;
-        acpi_status status2;
         struct acpi_evaluate_info *info;
         acpi_size buffer_space_needed;
         u32 i;
@@ -329,14 +328,12 @@ acpi_evaluate_object(acpi_handle handle,
                  * Delete the internal return object. NOTE: Interpreter must be
                  * locked to avoid race condition.
                  */
-                status2 = acpi_ex_enter_interpreter();
-                if (ACPI_SUCCESS(status2)) {
+                acpi_ex_enter_interpreter();
 
-                        /* Remove one reference on the return object (should delete it) */
+                /* Remove one reference on the return object (should delete it) */
 
-                        acpi_ut_remove_reference(info->return_object);
-                        acpi_ex_exit_interpreter();
-                }
+                acpi_ut_remove_reference(info->return_object);
+                acpi_ex_exit_interpreter();
         }
 
       cleanup: