ACPICA: Executer: Add interpreter tracing mode for method tracing facility

ACPICA commit 07fffd02607685b655ed92ee15c160e6a810b60b

The acpi_debug_trace() is the mechanism known as ACPI method tracing that is
used by Linux as ACPICA debugging message reducer. This facility can be
controlled through Linux ACPI subsystem - /sys/module/acpi/parameters.
This facility requires CONFIG_ACPI_DEBUG to be enabled to see ACPICA trace
logs in the kernel dmesg output.

This patch enhances acpi_debug_trace() to make it not only a message reducer,
but a real tracer to trace AML interpreter execution. Note that in addition
to the AML tracer enabling, this patch also updates the facility with the
following enhancements:
1. Allow a full path to be specified by the acpi_debug_trace() API.
2. Allow any method rather than just the entrance of acpi_evaluate_object()
   to be traced.
3. All interpreter ACPI_LV_TRACE_POINT messages are collected for
   ACPI_EXECUTER layer.

The Makefile of drivers/acpi/acpica is also updated to include exdebug.o
and the duplicated stubs are removed after that.

Note that since this patch has enhanced the method tracing facility, Linux
need also be updated after applying this patch. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/07fffd02
Signed-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>

12 files changed, 327 insertions, 185 deletions

diff --git a/drivers/acpi/acpica/acdebug.h b/drivers/acpi/acpica/acdebug.h
index 43685dd36c77..88482f75e941 100644
--- a/drivers/acpi/acpica/acdebug.h
+++ b/drivers/acpi/acpica/acdebug.h
@@ -102,6 +102,8 @@ void acpi_db_display_interfaces(char *action_arg, char *interface_name_arg);
 
 acpi_status acpi_db_sleep(char *object_arg);
 
+void acpi_db_trace(char *enable_arg, char *method_arg, char *once_arg);
+
 void acpi_db_display_locks(void);
 
 void acpi_db_display_resources(char *object_arg);
diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 53f96a370762..5342300719ee 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -290,8 +290,6 @@ ACPI_GLOBAL(u32, acpi_fixed_event_count[ACPI_NUM_FIXED_EVENTS]);
 
 ACPI_GLOBAL(u32, acpi_gbl_original_dbg_level);
 ACPI_GLOBAL(u32, acpi_gbl_original_dbg_layer);
-ACPI_GLOBAL(u32, acpi_gbl_trace_dbg_level);
-ACPI_GLOBAL(u32, acpi_gbl_trace_dbg_layer);
 
 /*****************************************************************************
  *
diff --git a/drivers/acpi/acpica/acinterp.h b/drivers/acpi/acpica/acinterp.h
index 7ac98000b46b..a3c6e2ab93bb 100644
--- a/drivers/acpi/acpica/acinterp.h
+++ b/drivers/acpi/acpica/acinterp.h
@@ -131,6 +131,24 @@ void
 acpi_ex_do_debug_object(union acpi_operand_object *source_desc,
 			u32 level, u32 index);
 
+void
+acpi_ex_start_trace_method(struct acpi_namespace_node *method_node,
+			   union acpi_operand_object *obj_desc,
+			   struct acpi_walk_state *walk_state);
+
+void
+acpi_ex_stop_trace_method(struct acpi_namespace_node *method_node,
+			  union acpi_operand_object *obj_desc,
+			  struct acpi_walk_state *walk_state);
+
+void
+acpi_ex_start_trace_opcode(union acpi_parse_object *op,
+			   struct acpi_walk_state *walk_state);
+
+void
+acpi_ex_stop_trace_opcode(union acpi_parse_object *op,
+			  struct acpi_walk_state *walk_state);
+
 /*
  * exfield - ACPI AML (p-code) execution - field manipulation
  */
diff --git a/drivers/acpi/acpica/dsdebug.c b/drivers/acpi/acpica/dsdebug.c
index 7df9b50e17a7..a651d30133d0 100644
--- a/drivers/acpi/acpica/dsdebug.c
+++ b/drivers/acpi/acpica/dsdebug.c
@@ -48,6 +48,7 @@
 #ifdef ACPI_DISASSEMBLER
 #include "acdisasm.h"
 #endif
+#include "acinterp.h"
 
 #define _COMPONENT          ACPI_DISPATCHER
 ACPI_MODULE_NAME("dsdebug")
@@ -128,7 +129,6 @@ acpi_ds_dump_method_stack(acpi_status status,
 	struct acpi_walk_state *next_walk_state;
 	struct acpi_namespace_node *previous_method = NULL;
 	union acpi_operand_object *method_desc;
-	char *pathname = NULL;
 
 	ACPI_FUNCTION_TRACE(ds_dump_method_stack);
 
@@ -173,25 +173,10 @@ acpi_ds_dump_method_stack(acpi_status status,
 
 	while (next_walk_state) {
 		method_desc = next_walk_state->method_desc;
-		if (method_desc && method_desc->method.node) {
-			pathname = acpi_ns_get_normalized_pathname((struct
-								    acpi_namespace_node
-								    *)
-								   method_desc->
-								   method.node,
-								   TRUE);
-		}
-		if (pathname) {
-			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-					  "End method [0x%p:%s] execution.\n",
-					  method_desc->method.aml_start,
-					  pathname));
-			ACPI_FREE(pathname);
-			pathname = NULL;
-		} else {
-			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-					  "End method [0x%p] execution.\n",
-					  method_desc->method.aml_start));
+		if (method_desc) {
+			acpi_ex_stop_trace_method((struct acpi_namespace_node *)
+						  method_desc->method.node,
+						  method_desc, walk_state);
 		}
 
 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c
index 0fa6f19aab3a..ea2bdde1227e 100644
--- a/drivers/acpi/acpica/dsmethod.c
+++ b/drivers/acpi/acpica/dsmethod.c
@@ -327,7 +327,6 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 			       struct acpi_walk_state *walk_state)
 {
 	acpi_status status = AE_OK;
-	char *pathname = NULL;
 
 	ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 
@@ -335,17 +334,7 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 		return_ACPI_STATUS(AE_NULL_ENTRY);
 	}
 
-	pathname = acpi_ns_get_normalized_pathname(method_node, TRUE);
-	if (pathname) {
-		ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-				  "Begin method [0x%p:%s] execution.\n",
-				  obj_desc->method.aml_start, pathname));
-		ACPI_FREE(pathname);
-	} else {
-		ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-				  "Begin method [0x%p] execution.\n",
-				  obj_desc->method.aml_start));
-	}
+	acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
 
 	/* Prevent wraparound of thread count */
 
@@ -708,7 +697,6 @@ void
 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 				 struct acpi_walk_state *walk_state)
 {
-	char *pathname = NULL;
 
 	ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 
@@ -846,22 +834,8 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 		}
 	}
 
-	if (method_desc->method.node) {
-		pathname = acpi_ns_get_normalized_pathname((struct
-							    acpi_namespace_node
-							    *)method_desc->
-							   method.node, TRUE);
-	}
-	if (pathname) {
-		ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-				  "End method [0x%p:%s] execution.\n",
-				  method_desc->method.aml_start, pathname));
-		ACPI_FREE(pathname);
-	} else {
-		ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-				  "End method [0x%p] execution.\n",
-				  method_desc->method.aml_start));
-	}
+	acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
+				  method.node, method_desc, walk_state);
 
 	return_VOID;
 }
diff --git a/drivers/acpi/acpica/exdebug.c b/drivers/acpi/acpica/exdebug.c
index 815442bbd051..00ba9fc85f47 100644
--- a/drivers/acpi/acpica/exdebug.c
+++ b/drivers/acpi/acpica/exdebug.c
@@ -43,11 +43,15 @@
 
 #include <acpi/acpi.h>
 #include "accommon.h"
+#include "acnamesp.h"
 #include "acinterp.h"
+#include "acparser.h"
 
 #define _COMPONENT          ACPI_EXECUTER
 ACPI_MODULE_NAME("exdebug")
 
+static union acpi_operand_object *acpi_gbl_trace_method_object = NULL;
+
 #ifndef ACPI_NO_ERROR_MESSAGES
 /*******************************************************************************
  *
@@ -70,6 +74,7 @@ ACPI_MODULE_NAME("exdebug")
  * enabled if necessary.
  *
  ******************************************************************************/
+
 void
 acpi_ex_do_debug_object(union acpi_operand_object *source_desc,
 			u32 level, u32 index)
@@ -308,3 +313,269 @@ acpi_ex_do_debug_object(union acpi_operand_object *source_desc,
 	return_VOID;
 }
 #endif
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ex_interpreter_trace_enabled
+ *
+ * PARAMETERS:  name                - Whether method name should be matched,
+ *                                    this should be checked before starting
+ *                                    the tracer
+ *
+ * RETURN:      TRUE if interpreter trace is enabled.
+ *
+ * DESCRIPTION: Check whether interpreter trace is enabled
+ *
+ ******************************************************************************/
+
+static u8 acpi_ex_interpreter_trace_enabled(char *name)
+{
+
+	/* Check if tracing is enabled */
+
+	if (!(acpi_gbl_trace_flags & ACPI_TRACE_ENABLED)) {
+		return (FALSE);
+	}
+
+	/*
+	 * Check if tracing is filtered:
+	 *
+	 * 1. If the tracer is started, acpi_gbl_trace_method_object should have
+	 *    been filled by the trace starter
+	 * 2. If the tracer is not started, acpi_gbl_trace_method_name should be
+	 *    matched if it is specified
+	 * 3. If the tracer is oneshot style, acpi_gbl_trace_method_name should
+	 *    not be cleared by the trace stopper during the first match
+	 */
+	if (acpi_gbl_trace_method_object) {
+		return (TRUE);
+	}
+	if (name &&
+	    (acpi_gbl_trace_method_name &&
+	     strcmp(acpi_gbl_trace_method_name, name))) {
+		return (FALSE);
+	}
+	if ((acpi_gbl_trace_flags & ACPI_TRACE_ONESHOT) &&
+	    !acpi_gbl_trace_method_name) {
+		return (FALSE);
+	}
+
+	return (TRUE);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ex_start_trace_method
+ *
+ * PARAMETERS:  method_node         - Node of the method
+ *              obj_desc            - The method object
+ *              walk_state          - current state, NULL if not yet executing
+ *                                    a method.
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Start control method execution trace
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_start_trace_method(struct acpi_namespace_node *method_node,
+			   union acpi_operand_object *obj_desc,
+			   struct acpi_walk_state *walk_state)
+{
+	acpi_status status;
+	char *pathname = NULL;
+	u8 enabled = FALSE;
+
+	ACPI_FUNCTION_NAME(ex_start_trace_method);
+
+	if (method_node) {
+		pathname = acpi_ns_get_normalized_pathname(method_node, TRUE);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		goto exit;
+	}
+
+	enabled = acpi_ex_interpreter_trace_enabled(pathname);
+	if (enabled && !acpi_gbl_trace_method_object) {
+		acpi_gbl_trace_method_object = obj_desc;
+		acpi_gbl_original_dbg_level = acpi_dbg_level;
+		acpi_gbl_original_dbg_layer = acpi_dbg_layer;
+		acpi_dbg_level = ACPI_TRACE_LEVEL_ALL;
+		acpi_dbg_layer = ACPI_TRACE_LAYER_ALL;
+
+		if (acpi_gbl_trace_dbg_level) {
+			acpi_dbg_level = acpi_gbl_trace_dbg_level;
+		}
+		if (acpi_gbl_trace_dbg_layer) {
+			acpi_dbg_layer = acpi_gbl_trace_dbg_layer;
+		}
+	}
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+exit:
+	if (enabled) {
+		if (pathname) {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "Begin method [0x%p:%s] execution.\n",
+					  obj_desc->method.aml_start,
+					  pathname));
+		} else {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "Begin method [0x%p] execution.\n",
+					  obj_desc->method.aml_start));
+		}
+	}
+	if (pathname) {
+		ACPI_FREE(pathname);
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ex_stop_trace_method
+ *
+ * PARAMETERS:  method_node         - Node of the method
+ *              obj_desc            - The method object
+ *              walk_state          - current state, NULL if not yet executing
+ *                                    a method.
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Stop control method execution trace
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_stop_trace_method(struct acpi_namespace_node *method_node,
+			  union acpi_operand_object *obj_desc,
+			  struct acpi_walk_state *walk_state)
+{
+	acpi_status status;
+	char *pathname = NULL;
+	u8 enabled;
+
+	ACPI_FUNCTION_NAME(ex_stop_trace_method);
+
+	if (method_node) {
+		pathname = acpi_ns_get_normalized_pathname(method_node, TRUE);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		goto exit_path;
+	}
+
+	enabled = acpi_ex_interpreter_trace_enabled(NULL);
+
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+	if (enabled) {
+		if (pathname) {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "End method [0x%p:%s] execution.\n",
+					  obj_desc->method.aml_start,
+					  pathname));
+		} else {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "End method [0x%p] execution.\n",
+					  obj_desc->method.aml_start));
+		}
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		goto exit_path;
+	}
+
+	/* Check whether the tracer should be stopped */
+
+	if (acpi_gbl_trace_method_object == obj_desc) {
+
+		/* Disable further tracing if type is one-shot */
+
+		if (acpi_gbl_trace_flags & ACPI_TRACE_ONESHOT) {
+			acpi_gbl_trace_method_name = NULL;
+		}
+
+		acpi_dbg_level = acpi_gbl_original_dbg_level;
+		acpi_dbg_layer = acpi_gbl_original_dbg_layer;
+		acpi_gbl_trace_method_object = NULL;
+	}
+
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+exit_path:
+	if (pathname) {
+		ACPI_FREE(pathname);
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ex_start_trace_opcode
+ *
+ * PARAMETERS:  op                  - The parser opcode object
+ *              walk_state          - current state, NULL if not yet executing
+ *                                    a method.
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Start opcode execution trace
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_start_trace_opcode(union acpi_parse_object *op,
+			   struct acpi_walk_state *walk_state)
+{
+
+	ACPI_FUNCTION_NAME(ex_start_trace_opcode);
+
+	if (acpi_ex_interpreter_trace_enabled(NULL)) {
+		if (walk_state->op_info) {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "Begin opcode: %s[0x%p] Class=0x%02x, Type=0x%02x, Flags=0x%04x.\n",
+					  op->common.aml_op_name,
+					  op->common.aml,
+					  walk_state->op_info->class,
+					  walk_state->op_info->type,
+					  walk_state->op_info->flags));
+		} else {
+			ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+					  "Begin opcode: %s[0x%p].\n",
+					  op->common.aml_op_name,
+					  op->common.aml));
+		}
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ex_stop_trace_opcode
+ *
+ * PARAMETERS:  op                  - The parser opcode object
+ *              walk_state          - current state, NULL if not yet executing
+ *                                    a method.
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Stop opcode execution trace
+ *
+ ******************************************************************************/
+
+void
+acpi_ex_stop_trace_opcode(union acpi_parse_object *op,
+			  struct acpi_walk_state *walk_state)
+{
+
+	ACPI_FUNCTION_NAME(ex_stop_trace_opcode);
+
+	if (acpi_ex_interpreter_trace_enabled(NULL)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
+				  "End opcode: %s[0x%p].\n",
+				  op->common.aml_op_name, op->common.aml));
+	}
+}
diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c
index 80339ba56cad..a7de52ee1538 100644
--- a/drivers/acpi/acpica/psloop.c
+++ b/drivers/acpi/acpica/psloop.c
@@ -51,6 +51,7 @@
 
 #include <acpi/acpi.h>
 #include "accommon.h"
+#include "acinterp.h"
 #include "acparser.h"
 #include "acdispat.h"
 #include "amlcode.h"
@@ -498,20 +499,7 @@ acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
 						  op->common.aml));
 			}
 
-			if (walk_state->op_info) {
-				ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-						  "Begin opcode: %s[0x%p] Class=0x%02x, Type=0x%02x, Flags=0x%04x.\n",
-						  op->common.aml_op_name,
-						  op->common.aml,
-						  walk_state->op_info->class,
-						  walk_state->op_info->type,
-						  walk_state->op_info->flags));
-			} else {
-				ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-						  "Begin opcode: %s[0x%p].\n",
-						  op->common.aml_op_name,
-						  op->common.aml));
-			}
+			acpi_ex_start_trace_opcode(op, walk_state);
 		}
 
 		/*
diff --git a/drivers/acpi/acpica/psparse.c b/drivers/acpi/acpica/psparse.c
index 97ea0e5360f1..98001d7f6f80 100644
--- a/drivers/acpi/acpica/psparse.c
+++ b/drivers/acpi/acpica/psparse.c
@@ -147,9 +147,7 @@ acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
 		return_ACPI_STATUS(AE_OK);	/* OK for now */
 	}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_TRACE_POINT,
-			  "End opcode: %s[0x%p].\n",
-			  op->common.aml_op_name, op->common.aml));
+	acpi_ex_stop_trace_opcode(op, walk_state);
 
 	/* Delete this op and the subtree below it if asked to */
 
diff --git a/drivers/acpi/acpica/psxface.c b/drivers/acpi/acpica/psxface.c
index 1f3f46d44312..4254805dd319 100644
--- a/drivers/acpi/acpica/psxface.c
+++ b/drivers/acpi/acpica/psxface.c
@@ -47,15 +47,12 @@
 #include "acdispat.h"
 #include "acinterp.h"
 #include "actables.h"
+#include "acnamesp.h"
 
 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psxface")
 
 /* Local Prototypes */
-static void acpi_ps_start_trace(struct acpi_evaluate_info *info);
-
-static void acpi_ps_stop_trace(struct acpi_evaluate_info *info);
-
 static void
 acpi_ps_update_parameter_list(struct acpi_evaluate_info *info, u16 action);
 
@@ -76,7 +73,7 @@ acpi_ps_update_parameter_list(struct acpi_evaluate_info *info, u16 action);
  ******************************************************************************/
 
 acpi_status
-acpi_debug_trace(char *name, u32 debug_level, u32 debug_layer, u32 flags)
+acpi_debug_trace(const char *name, u32 debug_level, u32 debug_layer, u32 flags)
 {
 	acpi_status status;
 
@@ -85,108 +82,14 @@ acpi_debug_trace(char *name, u32 debug_level, u32 debug_layer, u32 flags)
 		return (status);
 	}
 
-	/* TBDs: Validate name, allow full path or just nameseg */
-
-	acpi_gbl_trace_method_name = *ACPI_CAST_PTR(u32, name);
+	acpi_gbl_trace_method_name = name;
 	acpi_gbl_trace_flags = flags;
-
-	if (debug_level) {
-		acpi_gbl_trace_dbg_level = debug_level;
-	}
-	if (debug_layer) {
-		acpi_gbl_trace_dbg_layer = debug_layer;
-	}
+	acpi_gbl_trace_dbg_level = debug_level;
+	acpi_gbl_trace_dbg_layer = debug_layer;
+	status = AE_OK;
 
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
-	return (AE_OK);
-}
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_ps_start_trace
- *
- * PARAMETERS:  info        - Method info struct
- *
- * RETURN:      None
- *
- * DESCRIPTION: Start control method execution trace
- *
- ******************************************************************************/
-
-static void acpi_ps_start_trace(struct acpi_evaluate_info *info)
-{
-	acpi_status status;
-
-	ACPI_FUNCTION_ENTRY();
-
-	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
-	if (ACPI_FAILURE(status)) {
-		return;
-	}
-
-	if ((!acpi_gbl_trace_method_name) ||
-	    (acpi_gbl_trace_method_name != info->node->name.integer)) {
-		goto exit;
-	}
-
-	acpi_gbl_original_dbg_level = acpi_dbg_level;
-	acpi_gbl_original_dbg_layer = acpi_dbg_layer;
-
-	acpi_dbg_level = 0x00FFFFFF;
-	acpi_dbg_layer = ACPI_UINT32_MAX;
-
-	if (acpi_gbl_trace_dbg_level) {
-		acpi_dbg_level = acpi_gbl_trace_dbg_level;
-	}
-	if (acpi_gbl_trace_dbg_layer) {
-		acpi_dbg_layer = acpi_gbl_trace_dbg_layer;
-	}
-
-exit:
-	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
-}
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_ps_stop_trace
- *
- * PARAMETERS:  info        - Method info struct
- *
- * RETURN:      None
- *
- * DESCRIPTION: Stop control method execution trace
- *
- ******************************************************************************/
-
-static void acpi_ps_stop_trace(struct acpi_evaluate_info *info)
-{
-	acpi_status status;
-
-	ACPI_FUNCTION_ENTRY();
-
-	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
-	if (ACPI_FAILURE(status)) {
-		return;
-	}
-
-	if ((!acpi_gbl_trace_method_name) ||
-	    (acpi_gbl_trace_method_name != info->node->name.integer)) {
-		goto exit;
-	}
-
-	/* Disable further tracing if type is one-shot */
-
-	if (acpi_gbl_trace_flags & 1) {
-		acpi_gbl_trace_method_name = 0;
-		acpi_gbl_trace_dbg_level = 0;
-		acpi_gbl_trace_dbg_layer = 0;
-	}
-
-	acpi_dbg_level = acpi_gbl_original_dbg_level;
-	acpi_dbg_layer = acpi_gbl_original_dbg_layer;
-
-exit:
-	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return (status);
 }
 
 /*******************************************************************************
@@ -212,7 +115,7 @@ exit:
  *
  ******************************************************************************/
 
-acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
+acpi_status acpi_ps_execute_method(struct acpi_evaluate_info * info)
 {
 	acpi_status status;
 	union acpi_parse_object *op;
@@ -243,10 +146,6 @@ acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
 	 */
 	acpi_ps_update_parameter_list(info, REF_INCREMENT);
 
-	/* Begin tracing if requested */
-
-	acpi_ps_start_trace(info);
-
 	/*
 	 * Execute the method. Performs parse simultaneously
 	 */
@@ -326,10 +225,6 @@ acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
 cleanup:
 	acpi_ps_delete_parse_tree(op);
 
-	/* End optional tracing */
-
-	acpi_ps_stop_trace(info);
-
 	/* Take away the extra reference that we gave the parameters above */
 
 	acpi_ps_update_parameter_list(info, REF_DECREMENT);
diff --git a/drivers/acpi/acpica/utinit.c b/drivers/acpi/acpica/utinit.c
index e402e07b4846..7f897c63aa5b 100644
--- a/drivers/acpi/acpica/utinit.c
+++ b/drivers/acpi/acpica/utinit.c
@@ -204,8 +204,6 @@ acpi_status acpi_ut_init_globals(void)
 	acpi_gbl_acpi_hardware_present = TRUE;
 	acpi_gbl_last_owner_id_index = 0;
 	acpi_gbl_next_owner_id_offset = 0;
-	acpi_gbl_trace_dbg_level = 0;
-	acpi_gbl_trace_dbg_layer = 0;
 	acpi_gbl_debugger_configuration = DEBUGGER_THREADING;
 	acpi_gbl_osi_mutex = NULL;
 	acpi_gbl_reg_methods_executed = FALSE;
diff --git a/include/acpi/acoutput.h b/include/acpi/acoutput.h
index 8f89df9c7295..37f46d49a74a 100644
--- a/include/acpi/acoutput.h
+++ b/include/acpi/acoutput.h
@@ -184,6 +184,19 @@
 #define ACPI_NORMAL_DEFAULT         (ACPI_LV_INIT | ACPI_LV_DEBUG_OBJECT | ACPI_LV_REPAIR)
 #define ACPI_DEBUG_ALL              (ACPI_LV_AML_DISASSEMBLE | ACPI_LV_ALL_EXCEPTIONS | ACPI_LV_ALL)
 
+/*
+ * Global trace flags
+ */
+#define ACPI_TRACE_ENABLED          ((u32) 2)
+#define ACPI_TRACE_ONESHOT          ((u32) 1)
+
+/* Defaults for trace debugging level/layer */
+
+#define ACPI_TRACE_LEVEL_ALL        ACPI_LV_ALL
+#define ACPI_TRACE_LAYER_ALL        0x000001FF
+#define ACPI_TRACE_LEVEL_DEFAULT    ACPI_LV_TRACE_POINT
+#define ACPI_TRACE_LAYER_DEFAULT    ACPI_EXECUTER
+
 #if defined (ACPI_DEBUG_OUTPUT) || !defined (ACPI_NO_ERROR_MESSAGES)
 /*
  * The module name is used primarily for error and debug messages.
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index e8ec18a4a634..9c362cf14264 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -251,7 +251,9 @@ ACPI_INIT_GLOBAL(u8, acpi_gbl_reduced_hardware, FALSE);
  * traced each time it is executed.
  */
 ACPI_INIT_GLOBAL(u32, acpi_gbl_trace_flags, 0);
-ACPI_INIT_GLOBAL(acpi_name, acpi_gbl_trace_method_name, 0);
+ACPI_INIT_GLOBAL(const char *, acpi_gbl_trace_method_name, NULL);
+ACPI_INIT_GLOBAL(u32, acpi_gbl_trace_dbg_level, ACPI_TRACE_LEVEL_DEFAULT);
+ACPI_INIT_GLOBAL(u32, acpi_gbl_trace_dbg_layer, ACPI_TRACE_LAYER_DEFAULT);
 
 /*
  * Runtime configuration of debug output control masks. We want the debug
@@ -504,7 +506,7 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status
 					   acpi_object_handler handler,
 					   void **data))
 ACPI_EXTERNAL_RETURN_STATUS(acpi_status
-			     acpi_debug_trace(char *name, u32 debug_level,
+			     acpi_debug_trace(const char *name, u32 debug_level,
 					      u32 debug_layer, u32 flags))
 
 /*