545 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			545 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
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|  *
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|  * Deterministic automata (DA) monitor functions, to be used together
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|  * with automata models in C generated by the dot2k tool.
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|  *
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|  * The dot2k tool is available at tools/verification/dot2k/
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|  *
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|  * For further information, see:
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|  *   Documentation/trace/rv/da_monitor_synthesis.rst
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|  */
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| 
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| #include <rv/automata.h>
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| #include <linux/rv.h>
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| #include <linux/bug.h>
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| 
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| #ifdef CONFIG_RV_REACTORS
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| 
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| #define DECLARE_RV_REACTING_HELPERS(name, type)							\
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| static char REACT_MSG_##name[1024];								\
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| 												\
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| static inline char *format_react_msg_##name(type curr_state, type event)			\
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| {												\
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| 	snprintf(REACT_MSG_##name, 1024,							\
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| 		 "rv: monitor %s does not allow event %s on state %s\n",			\
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| 		 #name,										\
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| 		 model_get_event_name_##name(event),						\
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| 		 model_get_state_name_##name(curr_state));					\
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| 	return REACT_MSG_##name;								\
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| }												\
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| 												\
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| static void cond_react_##name(char *msg)							\
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| {												\
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| 	if (rv_##name.react)									\
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| 		rv_##name.react(msg);								\
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| }												\
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| 												\
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| static bool rv_reacting_on_##name(void)								\
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| {												\
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| 	return rv_reacting_on();								\
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| }
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| 
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| #else /* CONFIG_RV_REACTOR */
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| 
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| #define DECLARE_RV_REACTING_HELPERS(name, type)							\
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| static inline char *format_react_msg_##name(type curr_state, type event)			\
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| {												\
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| 	return NULL;										\
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| }												\
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| 												\
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| static void cond_react_##name(char *msg)							\
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| {												\
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| 	return;											\
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| }												\
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| 												\
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| static bool rv_reacting_on_##name(void)								\
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| {												\
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| 	return 0;										\
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| }
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| #endif
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| 
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| /*
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|  * Generic helpers for all types of deterministic automata monitors.
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|  */
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| #define DECLARE_DA_MON_GENERIC_HELPERS(name, type)						\
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| 												\
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| DECLARE_RV_REACTING_HELPERS(name, type)								\
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| 												\
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| /*												\
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|  * da_monitor_reset_##name - reset a monitor and setting it to init state			\
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|  */												\
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| static inline void da_monitor_reset_##name(struct da_monitor *da_mon)				\
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| {												\
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| 	da_mon->monitoring = 0;									\
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| 	da_mon->curr_state = model_get_initial_state_##name();					\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_curr_state_##name - return the current state					\
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|  */												\
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| static inline type da_monitor_curr_state_##name(struct da_monitor *da_mon)			\
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| {												\
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| 	return da_mon->curr_state;								\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_set_state_##name - set the new current state					\
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|  */												\
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| static inline void										\
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| da_monitor_set_state_##name(struct da_monitor *da_mon, enum states_##name state)		\
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| {												\
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| 	da_mon->curr_state = state;								\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_start_##name - start monitoring							\
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|  *												\
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|  * The monitor will ignore all events until monitoring is set to true. This			\
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|  * function needs to be called to tell the monitor to start monitoring.				\
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|  */												\
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| static inline void da_monitor_start_##name(struct da_monitor *da_mon)				\
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| {												\
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| 	da_mon->curr_state = model_get_initial_state_##name();					\
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| 	da_mon->monitoring = 1;									\
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| }												\
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| 												\
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| /*												\
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|  * da_monitoring_##name - returns true if the monitor is processing events			\
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|  */												\
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| static inline bool da_monitoring_##name(struct da_monitor *da_mon)				\
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| {												\
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| 	return da_mon->monitoring;								\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_enabled_##name - checks if the monitor is enabled					\
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|  */												\
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| static inline bool da_monitor_enabled_##name(void)						\
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| {												\
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| 	/* global switch */									\
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| 	if (unlikely(!rv_monitoring_on()))							\
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| 		return 0;									\
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| 												\
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| 	/* monitor enabled */									\
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| 	if (unlikely(!rv_##name.enabled))							\
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| 		return 0;									\
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| 												\
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| 	return 1;										\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_handling_event_##name - checks if the monitor is ready to handle events		\
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|  */												\
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| static inline bool da_monitor_handling_event_##name(struct da_monitor *da_mon)			\
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| {												\
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| 												\
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| 	if (!da_monitor_enabled_##name())							\
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| 		return 0;									\
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| 												\
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| 	/* monitor is actually monitoring */							\
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| 	if (unlikely(!da_monitoring_##name(da_mon)))						\
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| 		return 0;									\
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| 												\
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| 	return 1;										\
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| }
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| 
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| /*
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|  * Event handler for implicit monitors. Implicit monitor is the one which the
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|  * handler does not need to specify which da_monitor to manipulate. Examples
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|  * of implicit monitor are the per_cpu or the global ones.
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|  */
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| #define DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type)					\
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| 												\
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| static inline bool										\
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| da_event_##name(struct da_monitor *da_mon, enum events_##name event)				\
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| {												\
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| 	type curr_state = da_monitor_curr_state_##name(da_mon);					\
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| 	type next_state = model_get_next_state_##name(curr_state, event);			\
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| 												\
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| 	if (next_state != INVALID_STATE) {							\
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| 		da_monitor_set_state_##name(da_mon, next_state);				\
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| 												\
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| 		trace_event_##name(model_get_state_name_##name(curr_state),			\
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| 				   model_get_event_name_##name(event),				\
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| 				   model_get_state_name_##name(next_state),			\
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| 				   model_is_final_state_##name(next_state));			\
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| 												\
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| 		return true;									\
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| 	}											\
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| 												\
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| 	if (rv_reacting_on_##name())								\
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| 		cond_react_##name(format_react_msg_##name(curr_state, event));			\
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| 												\
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| 	trace_error_##name(model_get_state_name_##name(curr_state),				\
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| 			   model_get_event_name_##name(event));					\
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| 												\
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| 	return false;										\
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| }												\
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| 
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| /*
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|  * Event handler for per_task monitors.
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|  */
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| #define DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type)					\
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| 												\
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| static inline bool da_event_##name(struct da_monitor *da_mon, struct task_struct *tsk,		\
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| 				   enum events_##name event)					\
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| {												\
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| 	type curr_state = da_monitor_curr_state_##name(da_mon);					\
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| 	type next_state = model_get_next_state_##name(curr_state, event);			\
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| 												\
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| 	if (next_state != INVALID_STATE) {							\
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| 		da_monitor_set_state_##name(da_mon, next_state);				\
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| 												\
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| 		trace_event_##name(tsk->pid,							\
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| 				   model_get_state_name_##name(curr_state),			\
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| 				   model_get_event_name_##name(event),				\
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| 				   model_get_state_name_##name(next_state),			\
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| 				   model_is_final_state_##name(next_state));			\
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| 												\
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| 		return true;									\
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| 	}											\
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| 												\
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| 	if (rv_reacting_on_##name())								\
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| 		cond_react_##name(format_react_msg_##name(curr_state, event));			\
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| 												\
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| 	trace_error_##name(tsk->pid,								\
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| 			   model_get_state_name_##name(curr_state),				\
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| 			   model_get_event_name_##name(event));					\
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| 												\
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| 	return false;										\
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| }
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| 
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| /*
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|  * Functions to define, init and get a global monitor.
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|  */
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| #define DECLARE_DA_MON_INIT_GLOBAL(name, type)							\
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| 												\
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| /*												\
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|  * global monitor (a single variable)								\
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|  */												\
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| static struct da_monitor da_mon_##name;								\
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| 												\
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| /*												\
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|  * da_get_monitor_##name - return the global monitor address					\
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|  */												\
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| static struct da_monitor *da_get_monitor_##name(void)						\
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| {												\
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| 	return &da_mon_##name;									\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_reset_all_##name - reset the single monitor					\
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|  */												\
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| static void da_monitor_reset_all_##name(void)							\
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| {												\
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| 	da_monitor_reset_##name(da_get_monitor_##name());					\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_init_##name - initialize a monitor						\
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|  */												\
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| static inline int da_monitor_init_##name(void)							\
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| {												\
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| 	da_monitor_reset_all_##name();								\
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| 	return 0;										\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_destroy_##name - destroy the monitor						\
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|  */												\
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| static inline void da_monitor_destroy_##name(void)						\
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| {												\
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| 	return;											\
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| }
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| 
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| /*
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|  * Functions to define, init and get a per-cpu monitor.
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|  */
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| #define DECLARE_DA_MON_INIT_PER_CPU(name, type)							\
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| 												\
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| /*												\
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|  * per-cpu monitor variables									\
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|  */												\
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| static DEFINE_PER_CPU(struct da_monitor, da_mon_##name);					\
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| 												\
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| /*												\
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|  * da_get_monitor_##name - return current CPU monitor address					\
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|  */												\
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| static struct da_monitor *da_get_monitor_##name(void)						\
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| {												\
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| 	return this_cpu_ptr(&da_mon_##name);							\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_reset_all_##name - reset all CPUs' monitor					\
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|  */												\
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| static void da_monitor_reset_all_##name(void)							\
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| {												\
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| 	struct da_monitor *da_mon;								\
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| 	int cpu;										\
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| 	for_each_cpu(cpu, cpu_online_mask) {							\
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| 		da_mon = per_cpu_ptr(&da_mon_##name, cpu);					\
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| 		da_monitor_reset_##name(da_mon);						\
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| 	}											\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_init_##name - initialize all CPUs' monitor					\
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|  */												\
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| static inline int da_monitor_init_##name(void)							\
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| {												\
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| 	da_monitor_reset_all_##name();								\
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| 	return 0;										\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_destroy_##name - destroy the monitor						\
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|  */												\
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| static inline void da_monitor_destroy_##name(void)						\
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| {												\
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| 	return;											\
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| }
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| 
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| /*
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|  * Functions to define, init and get a per-task monitor.
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|  */
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| #define DECLARE_DA_MON_INIT_PER_TASK(name, type)						\
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| 												\
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| /*												\
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|  * The per-task monitor is stored a vector in the task struct. This variable			\
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|  * stores the position on the vector reserved for this monitor.					\
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|  */												\
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| static int task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT;					\
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| 												\
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| /*												\
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|  * da_get_monitor_##name - return the monitor in the allocated slot for tsk 			\
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|  */												\
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| static inline struct da_monitor *da_get_monitor_##name(struct task_struct *tsk)			\
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| {												\
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| 	return &tsk->rv[task_mon_slot_##name].da_mon;						\
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| }												\
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| 												\
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| static void da_monitor_reset_all_##name(void)							\
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| {												\
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| 	struct task_struct *g, *p;								\
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| 												\
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| 	read_lock(&tasklist_lock);								\
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| 	for_each_process_thread(g, p)								\
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| 		da_monitor_reset_##name(da_get_monitor_##name(p));				\
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| 	read_unlock(&tasklist_lock);								\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_init_##name - initialize the per-task monitor					\
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|  *												\
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|  * Try to allocate a slot in the task's vector of monitors. If there				\
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|  * is an available slot, use it and reset all task's monitor.					\
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|  */												\
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| static int da_monitor_init_##name(void)								\
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| {												\
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| 	int slot;										\
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| 												\
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| 	slot = rv_get_task_monitor_slot();							\
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| 	if (slot < 0 || slot >= RV_PER_TASK_MONITOR_INIT)					\
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| 		return slot;									\
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| 												\
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| 	task_mon_slot_##name = slot;								\
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| 												\
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| 	da_monitor_reset_all_##name();								\
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| 	return 0;										\
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| }												\
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| 												\
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| /*												\
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|  * da_monitor_destroy_##name - return the allocated slot					\
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|  */												\
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| static inline void da_monitor_destroy_##name(void)						\
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| {												\
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| 	if (task_mon_slot_##name == RV_PER_TASK_MONITOR_INIT) {					\
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| 		WARN_ONCE(1, "Disabling a disabled monitor: " #name);				\
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| 		return;										\
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| 	}											\
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| 	rv_put_task_monitor_slot(task_mon_slot_##name);						\
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| 	task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT;					\
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| 	return;											\
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| }
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| 
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| /*
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|  * Handle event for implicit monitor: da_get_monitor_##name() will figure out
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|  * the monitor.
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|  */
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| #define DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)					\
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| 												\
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| static inline void __da_handle_event_##name(struct da_monitor *da_mon,				\
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| 					    enum events_##name event)				\
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| {												\
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| 	bool retval;										\
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| 												\
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| 	retval = da_event_##name(da_mon, event);						\
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| 	if (!retval)										\
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| 		da_monitor_reset_##name(da_mon);						\
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| }												\
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| 												\
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| /*												\
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|  * da_handle_event_##name - handle an event							\
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|  */												\
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| static inline void da_handle_event_##name(enum events_##name event)				\
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| {												\
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| 	struct da_monitor *da_mon = da_get_monitor_##name();					\
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| 	bool retval;										\
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| 												\
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| 	retval = da_monitor_handling_event_##name(da_mon);					\
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| 	if (!retval)										\
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| 		return;										\
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| 												\
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| 	__da_handle_event_##name(da_mon, event);						\
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| }												\
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| 												\
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| /*												\
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|  * da_handle_start_event_##name - start monitoring or handle event				\
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|  *												\
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|  * This function is used to notify the monitor that the system is returning			\
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|  * to the initial state, so the monitor can start monitoring in the next event.			\
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|  * Thus:											\
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|  *												\
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|  * If the monitor already started, handle the event.						\
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|  * If the monitor did not start yet, start the monitor but skip the event.			\
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|  */												\
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| static inline bool da_handle_start_event_##name(enum events_##name event)			\
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| {												\
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| 	struct da_monitor *da_mon;								\
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| 												\
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| 	if (!da_monitor_enabled_##name())							\
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| 		return 0;									\
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| 												\
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| 	da_mon = da_get_monitor_##name();							\
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| 												\
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| 	if (unlikely(!da_monitoring_##name(da_mon))) {						\
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| 		da_monitor_start_##name(da_mon);						\
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| 		return 0;									\
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| 	}											\
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| 												\
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| 	__da_handle_event_##name(da_mon, event);						\
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| 												\
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| 	return 1;										\
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| }												\
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| 												\
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| /*												\
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|  * da_handle_start_run_event_##name - start monitoring and handle event				\
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|  *												\
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|  * This function is used to notify the monitor that the system is in the			\
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|  * initial state, so the monitor can start monitoring and handling event.			\
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|  */												\
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| static inline bool da_handle_start_run_event_##name(enum events_##name event)			\
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| {												\
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| 	struct da_monitor *da_mon;								\
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| 												\
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| 	if (!da_monitor_enabled_##name())							\
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| 		return 0;									\
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| 												\
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| 	da_mon = da_get_monitor_##name();							\
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| 												\
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| 	if (unlikely(!da_monitoring_##name(da_mon)))						\
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| 		da_monitor_start_##name(da_mon);						\
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| 												\
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| 	__da_handle_event_##name(da_mon, event);						\
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| 												\
 | |
| 	return 1;										\
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handle event for per task.
 | |
|  */
 | |
| #define DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type)					\
 | |
| 												\
 | |
| static inline void										\
 | |
| __da_handle_event_##name(struct da_monitor *da_mon, struct task_struct *tsk,			\
 | |
| 			 enum events_##name event)						\
 | |
| {												\
 | |
| 	bool retval;										\
 | |
| 												\
 | |
| 	retval = da_event_##name(da_mon, tsk, event);						\
 | |
| 	if (!retval)										\
 | |
| 		da_monitor_reset_##name(da_mon);						\
 | |
| }												\
 | |
| 												\
 | |
| /*												\
 | |
|  * da_handle_event_##name - handle an event							\
 | |
|  */												\
 | |
| static inline void										\
 | |
| da_handle_event_##name(struct task_struct *tsk, enum events_##name event)			\
 | |
| {												\
 | |
| 	struct da_monitor *da_mon = da_get_monitor_##name(tsk);					\
 | |
| 	bool retval;										\
 | |
| 												\
 | |
| 	retval = da_monitor_handling_event_##name(da_mon);					\
 | |
| 	if (!retval)										\
 | |
| 		return;										\
 | |
| 												\
 | |
| 	__da_handle_event_##name(da_mon, tsk, event);						\
 | |
| }												\
 | |
| 												\
 | |
| /*												\
 | |
|  * da_handle_start_event_##name - start monitoring or handle event				\
 | |
|  *												\
 | |
|  * This function is used to notify the monitor that the system is returning			\
 | |
|  * to the initial state, so the monitor can start monitoring in the next event.			\
 | |
|  * Thus:											\
 | |
|  *												\
 | |
|  * If the monitor already started, handle the event.						\
 | |
|  * If the monitor did not start yet, start the monitor but skip the event.			\
 | |
|  */												\
 | |
| static inline bool										\
 | |
| da_handle_start_event_##name(struct task_struct *tsk, enum events_##name event)			\
 | |
| {												\
 | |
| 	struct da_monitor *da_mon;								\
 | |
| 												\
 | |
| 	if (!da_monitor_enabled_##name())							\
 | |
| 		return 0;									\
 | |
| 												\
 | |
| 	da_mon = da_get_monitor_##name(tsk);							\
 | |
| 												\
 | |
| 	if (unlikely(!da_monitoring_##name(da_mon))) {						\
 | |
| 		da_monitor_start_##name(da_mon);						\
 | |
| 		return 0;									\
 | |
| 	}											\
 | |
| 												\
 | |
| 	__da_handle_event_##name(da_mon, tsk, event);						\
 | |
| 												\
 | |
| 	return 1;										\
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Entry point for the global monitor.
 | |
|  */
 | |
| #define DECLARE_DA_MON_GLOBAL(name, type)							\
 | |
| 												\
 | |
| DECLARE_AUTOMATA_HELPERS(name, type)								\
 | |
| DECLARE_DA_MON_GENERIC_HELPERS(name, type)							\
 | |
| DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type)						\
 | |
| DECLARE_DA_MON_INIT_GLOBAL(name, type)								\
 | |
| DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
 | |
| 
 | |
| /*
 | |
|  * Entry point for the per-cpu monitor.
 | |
|  */
 | |
| #define DECLARE_DA_MON_PER_CPU(name, type)							\
 | |
| 												\
 | |
| DECLARE_AUTOMATA_HELPERS(name, type)								\
 | |
| DECLARE_DA_MON_GENERIC_HELPERS(name, type)							\
 | |
| DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type)						\
 | |
| DECLARE_DA_MON_INIT_PER_CPU(name, type)								\
 | |
| DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
 | |
| 
 | |
| /*
 | |
|  * Entry point for the per-task monitor.
 | |
|  */
 | |
| #define DECLARE_DA_MON_PER_TASK(name, type)							\
 | |
| 												\
 | |
| DECLARE_AUTOMATA_HELPERS(name, type)								\
 | |
| DECLARE_DA_MON_GENERIC_HELPERS(name, type)							\
 | |
| DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type)						\
 | |
| DECLARE_DA_MON_INIT_PER_TASK(name, type)							\
 | |
| DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type)
 |