ACPICA: Fix issues/fault with automatic "serialized" method support

History: This support changes a method to "serialized" on the fly if the
method generates an AE_ALREADY_EXISTS error, indicating the possibility
that it cannot handle reentrancy.

This fix repairs a couple of issues seen in the field, especially on
machines with many cores.

1) Delete method children only upon the exit of the last thread, so
as to not delete objects out from under running threads.

2) Set the "serialized" bit for the method only upon the exit of the
last thread, so as to not cause deadlock when running threads attempt
to exit.

3) Cleanup the use of the AML "MethodFlags" and internal method flags
so that there is no longer any confustion between the two.

Reported-by: Dana Myers <dana.myers@oracle.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 47 insertions, 15 deletions

diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c
index d94dd8974b55..5a79f401a113 100644
--- a/drivers/acpi/acpica/dsmethod.c
+++ b/drivers/acpi/acpica/dsmethod.c
@@ -43,7 +43,6 @@
 
 #include <acpi/acpi.h>
 #include "accommon.h"
-#include "amlcode.h"
 #include "acdispat.h"
 #include "acinterp.h"
 #include "acnamesp.h"
@@ -201,7 +200,7 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 	/*
 	 * If this method is serialized, we need to acquire the method mutex.
 	 */
-	if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) {
+	if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
 		/*
 		 * Create a mutex for the method if it is defined to be Serialized
 		 * and a mutex has not already been created. We defer the mutex creation
@@ -413,8 +412,9 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 
 	/* Invoke an internal method if necessary */
 
-	if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
-		status = obj_desc->method.extra.implementation(next_walk_state);
+	if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
+		status =
+		    obj_desc->method.dispatch.implementation(next_walk_state);
 		if (status == AE_OK) {
 			status = AE_CTRL_TERMINATE;
 		}
@@ -579,11 +579,14 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 
 		/*
 		 * Delete any namespace objects created anywhere within the
-		 * namespace by the execution of this method. Unless this method
-		 * is a module-level executable code method, in which case we
-		 * want make the objects permanent.
+		 * namespace by the execution of this method. Unless:
+		 * 1) This method is a module-level executable code method, in which
+		 *    case we want make the objects permanent.
+		 * 2) There are other threads executing the method, in which case we
+		 *    will wait until the last thread has completed.
 		 */
-		if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) {
+		if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
+		    && (method_desc->method.thread_count == 1)) {
 
 			/* Delete any direct children of (created by) this method */
 
@@ -593,12 +596,17 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 			/*
 			 * Delete any objects that were created by this method
 			 * elsewhere in the namespace (if any were created).
+			 * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
+			 * deletion such that we don't have to perform an entire
+			 * namespace walk for every control method execution.
 			 */
 			if (method_desc->method.
-			    flags & AOPOBJ_MODIFIED_NAMESPACE) {
+			    info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
 				acpi_ns_delete_namespace_by_owner(method_desc->
 								  method.
 								  owner_id);
+				method_desc->method.info_flags &=
+				    ~ACPI_METHOD_MODIFIED_NAMESPACE;
 			}
 		}
 	}
@@ -629,19 +637,43 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 		 * Serialized if it appears that the method is incorrectly written and
 		 * does not support multiple thread execution. The best example of this
 		 * is if such a method creates namespace objects and blocks. A second
-		 * thread will fail with an AE_ALREADY_EXISTS exception
+		 * thread will fail with an AE_ALREADY_EXISTS exception.
 		 *
 		 * This code is here because we must wait until the last thread exits
-		 * before creating the synchronization semaphore.
+		 * before marking the method as serialized.
 		 */
-		if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED)
-		    && (!method_desc->method.mutex)) {
-			(void)acpi_ds_create_method_mutex(method_desc);
+		if (method_desc->method.
+		    info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
+			if (walk_state) {
+				ACPI_INFO((AE_INFO,
+					   "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
+					   walk_state->method_node->name.
+					   ascii));
+			}
+
+			/*
+			 * Method tried to create an object twice and was marked as
+			 * "pending serialized". The probable cause is that the method
+			 * cannot handle reentrancy.
+			 *
+			 * The method was created as not_serialized, but it tried to create
+			 * a named object and then blocked, causing the second thread
+			 * entrance to begin and then fail. Workaround this problem by
+			 * marking the method permanently as Serialized when the last
+			 * thread exits here.
+			 */
+			method_desc->method.info_flags &=
+			    ~ACPI_METHOD_SERIALIZED_PENDING;
+			method_desc->method.info_flags |=
+			    ACPI_METHOD_SERIALIZED;
+			method_desc->method.sync_level = 0;
 		}
 
 		/* No more threads, we can free the owner_id */
 
-		if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) {
+		if (!
+		    (method_desc->method.
+		     info_flags & ACPI_METHOD_MODULE_LEVEL)) {
 			acpi_ut_release_owner_id(&method_desc->method.owner_id);
 		}
 	}