ACPICA: Eliminate control method 2-pass parse/execute.

Completed an AML interpreter performance enhancement for control method
execution. Previously a 2-pass parse/execution, control methods are now
completely parsed and executed in single pass. This improves overall
interpreter performance by ~25%, reduces code size, and reduces CPU stack use.

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

3 files changed, 42 insertions, 124 deletions

diff --git a/drivers/acpi/dispatcher/dsmethod.c b/drivers/acpi/dispatcher/dsmethod.c
index cf888add3191..aa60dca1f8aa 100644
--- a/drivers/acpi/dispatcher/dsmethod.c
+++ b/drivers/acpi/dispatcher/dsmethod.c
@@ -327,7 +327,7 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 
         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
-                          "Execute method %p, currentstate=%p\n",
+                          "Calling method %p, currentstate=%p\n",
                           this_walk_state->prev_op, this_walk_state));
 
         /*
@@ -351,49 +351,7 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
                 return_ACPI_STATUS(status);
         }
 
-        /*
-         * 1) Parse the method. All "normal" methods are parsed for each execution.
-         * Internal methods (_OSI, etc.) do not require parsing.
-         */
-        if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
-
-                /* Create a new walk state for the parse */
-
-                next_walk_state =
-                    acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
-                                              obj_desc, NULL);
-                if (!next_walk_state) {
-                        status = AE_NO_MEMORY;
-                        goto cleanup;
-                }
-
-                /* Create and init a parse tree root */
-
-                op = acpi_ps_create_scope_op();
-                if (!op) {
-                        status = AE_NO_MEMORY;
-                        goto cleanup;
-                }
-
-                status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
-                                               obj_desc->method.aml_start,
-                                               obj_desc->method.aml_length,
-                                               NULL, 1);
-                if (ACPI_FAILURE(status)) {
-                        acpi_ps_delete_parse_tree(op);
-                        goto cleanup;
-                }
-
-                /* Begin AML parse (deletes next_walk_state) */
-
-                status = acpi_ps_parse_aml(next_walk_state);
-                acpi_ps_delete_parse_tree(op);
-                if (ACPI_FAILURE(status)) {
-                        goto cleanup;
-                }
-        }
-
-        /* 2) Begin method execution. Create a new walk state */
+        /* Begin method parse/execution. Create a new walk state */
 
         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
                                                     NULL, obj_desc, thread);
@@ -445,8 +403,8 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
         this_walk_state->num_operands = 0;
 
         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
-                          "Starting nested execution, newstate=%p\n",
-                          next_walk_state));
+                          "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
+                          method_node->name.ascii, next_walk_state));
 
         /* Invoke an internal method if necessary */
 
diff --git a/drivers/acpi/parser/psloop.c b/drivers/acpi/parser/psloop.c
index a83be5201856..881687ca3154 100644
--- a/drivers/acpi/parser/psloop.c
+++ b/drivers/acpi/parser/psloop.c
@@ -226,7 +226,7 @@ acpi_ps_build_named_op(struct acpi_walk_state *walk_state,
                 return_ACPI_STATUS(status);
         }
 
-        if (!op) {
+        if (!*op) {
                 return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
         }
 
diff --git a/drivers/acpi/parser/psxface.c b/drivers/acpi/parser/psxface.c
index 5d996c1140af..9069c697cf1d 100644
--- a/drivers/acpi/parser/psxface.c
+++ b/drivers/acpi/parser/psxface.c
@@ -54,8 +54,6 @@ static void acpi_ps_start_trace(struct acpi_evaluate_info *info);
 
 static void acpi_ps_stop_trace(struct acpi_evaluate_info *info);
 
-static acpi_status acpi_ps_execute_pass(struct acpi_evaluate_info *info);
-
 static void
 acpi_ps_update_parameter_list(struct acpi_evaluate_info *info, u16 action);
 
@@ -215,6 +213,8 @@ static void acpi_ps_stop_trace(struct acpi_evaluate_info *info)
 acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
 {
         acpi_status status;
+        union acpi_parse_object *op;
+        struct acpi_walk_state *walk_state;
 
         ACPI_FUNCTION_TRACE(ps_execute_method);
 
@@ -234,8 +234,7 @@ acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
         }
 
         /*
-         * The caller "owns" the parameters, so give each one an extra
-         * reference
+         * The caller "owns" the parameters, so give each one an extra reference
          */
         acpi_ps_update_parameter_list(info, REF_INCREMENT);
 
@@ -244,30 +243,50 @@ acpi_status acpi_ps_execute_method(struct acpi_evaluate_info *info)
         acpi_ps_start_trace(info);
 
         /*
-         * 1) Perform the first pass parse of the method to enter any
-         *    named objects that it creates into the namespace
+         * Execute the method. Performs parse simultaneously
          */
         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
-                          "**** Begin Method Parse **** Entry=%p obj=%p\n",
-                          info->resolved_node, info->obj_desc));
+                          "**** Begin Method Parse/Execute [%4.4s] **** Node=%p Obj=%p\n",
+                          info->resolved_node->name.ascii, info->resolved_node,
+                          info->obj_desc));
 
-        info->pass_number = 1;
-        status = acpi_ps_execute_pass(info);
-        if (ACPI_FAILURE(status)) {
+        /* Create and init a Root Node */
+
+        op = acpi_ps_create_scope_op();
+        if (!op) {
+                status = AE_NO_MEMORY;
                 goto cleanup;
         }
 
-        /*
-         * 2) Execute the method. Performs second pass parse simultaneously
-         */
-        ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
-                          "**** Begin Method Execution **** Entry=%p obj=%p\n",
-                          info->resolved_node, info->obj_desc));
+        /* Create and initialize a new walk state */
 
         info->pass_number = 3;
-        status = acpi_ps_execute_pass(info);
+        walk_state =
+            acpi_ds_create_walk_state(info->obj_desc->method.owner_id, NULL,
+                                      NULL, NULL);
+        if (!walk_state) {
+                status = AE_NO_MEMORY;
+                goto cleanup;
+        }
+
+        status = acpi_ds_init_aml_walk(walk_state, op, info->resolved_node,
+                                       info->obj_desc->method.aml_start,
+                                       info->obj_desc->method.aml_length, info,
+                                       info->pass_number);
+        if (ACPI_FAILURE(status)) {
+                acpi_ds_delete_walk_state(walk_state);
+                goto cleanup;
+        }
+
+        /* Parse the AML */
+
+        status = acpi_ps_parse_aml(walk_state);
+
+        /* walk_state was deleted by parse_aml */
 
       cleanup:
+        acpi_ps_delete_parse_tree(op);
+
         /* End optional tracing */
 
         acpi_ps_stop_trace(info);
@@ -330,62 +349,3 @@ acpi_ps_update_parameter_list(struct acpi_evaluate_info *info, u16 action)
                 }
         }
 }
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_ps_execute_pass
- *
- * PARAMETERS:  Info            - See struct acpi_evaluate_info
- *                                (Used: pass_number, Node, and obj_desc)
- *
- * RETURN:      Status
- *
- * DESCRIPTION: Single AML pass: Parse or Execute a control method
- *
- ******************************************************************************/
-
-static acpi_status acpi_ps_execute_pass(struct acpi_evaluate_info *info)
-{
-        acpi_status status;
-        union acpi_parse_object *op;
-        struct acpi_walk_state *walk_state;
-
-        ACPI_FUNCTION_TRACE(ps_execute_pass);
-
-        /* Create and init a Root Node */
-
-        op = acpi_ps_create_scope_op();
-        if (!op) {
-                return_ACPI_STATUS(AE_NO_MEMORY);
-        }
-
-        /* Create and initialize a new walk state */
-
-        walk_state =
-            acpi_ds_create_walk_state(info->obj_desc->method.owner_id, NULL,
-                                      NULL, NULL);
-        if (!walk_state) {
-                status = AE_NO_MEMORY;
-                goto cleanup;
-        }
-
-        status = acpi_ds_init_aml_walk(walk_state, op, info->resolved_node,
-                                       info->obj_desc->method.aml_start,
-                                       info->obj_desc->method.aml_length,
-                                       info->pass_number == 1 ? NULL : info,
-                                       info->pass_number);
-        if (ACPI_FAILURE(status)) {
-                acpi_ds_delete_walk_state(walk_state);
-                goto cleanup;
-        }
-
-        /* Parse the AML */
-
-        status = acpi_ps_parse_aml(walk_state);
-
-        /* Walk state was deleted by parse_aml */
-
-      cleanup:
-        acpi_ps_delete_parse_tree(op);
-        return_ACPI_STATUS(status);
-}