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, 2 insertions, 4 deletions

diff --git a/drivers/acpi/events/evxface.c b/drivers/acpi/events/evxface.c
index 923fd2b46955..a2af48ed88cd 100644
--- a/drivers/acpi/events/evxface.c
+++ b/drivers/acpi/events/evxface.c
@@ -768,11 +768,9 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
                 return (AE_BAD_PARAMETER);
         }
 
-        status = acpi_ex_enter_interpreter();
-        if (ACPI_FAILURE(status)) {
-                return (status);
-        }
+        /* Must lock interpreter to prevent race conditions */
 
+        acpi_ex_enter_interpreter();
         status = acpi_ev_acquire_global_lock(timeout);
         acpi_ex_exit_interpreter();