cregit-Linux how code gets into the kernel

Release 4.7 drivers/s390/net/fsm.h

Directory: drivers/s390/net
#ifndef _FSM_H_

#define _FSM_H_

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/atomic.h>

/**
 * Define this to get debugging messages.
 */

#define FSM_DEBUG         0

/**
 * Define this to get debugging massages for
 * timer handling.
 */

#define FSM_TIMER_DEBUG   0

/**
 * Define these to record a history of
 * Events/Statechanges and print it if a
 * action_function is not found.
 */

#define FSM_DEBUG_HISTORY 0

#define FSM_HISTORY_SIZE  40

struct fsm_instance_t;

/**
 * Definition of an action function, called by a FSM
 */

typedef void (*fsm_function_t)(struct fsm_instance_t *, int, void *);

/**
 * Internal jump table for a FSM
 */
typedef struct {
	
fsm_function_t *jumpmatrix;
	
int nr_events;
	
int nr_states;
	
const char **event_names;
	
const char **state_names;
} 
fsm;

#if FSM_DEBUG_HISTORY
/**
 * Element of State/Event history used for debugging.
 */
typedef struct {
	
int state;
	
int event;
} 
fsm_history;
#endif

/**
 * Representation of a FSM
 */

typedef struct fsm_instance_t {
	
fsm *f;
	
atomic_t state;
	
char name[16];
	
void *userdata;
	
int userint;
	
wait_queue_head_t wait_q;
#if FSM_DEBUG_HISTORY
	
int         history_index;
	
int         history_size;
	
fsm_history history[FSM_HISTORY_SIZE];
#endif
} 
fsm_instance;

/**
 * Description of a state-event combination
 */
typedef struct {
	
int cond_state;
	
int cond_event;
	
fsm_function_t function;
} 
fsm_node;

/**
 * Description of a FSM Timer.
 */
typedef struct {
	
fsm_instance *fi;
	
struct timer_list tl;
	
int expire_event;
	
void *event_arg;
} 
fsm_timer;

/**
 * Creates an FSM
 *
 * @param name        Name of this instance for logging purposes.
 * @param state_names An array of names for all states for logging purposes.
 * @param event_names An array of names for all events for logging purposes.
 * @param nr_states   Number of states for this instance.
 * @param nr_events   Number of events for this instance.
 * @param tmpl        An array of fsm_nodes, describing this FSM.
 * @param tmpl_len    Length of the describing array.
 * @param order       Parameter for allocation of the FSM data structs.
 */
extern fsm_instance *
init_fsm(char *name, const char **state_names,
	 const char **event_names,
	 int nr_states, int nr_events, const fsm_node *tmpl,
	 int tmpl_len, gfp_t order);

/**
 * Releases an FSM
 *
 * @param fi Pointer to an FSM, previously created with init_fsm.
 */
extern void kfree_fsm(fsm_instance *fi);

#if FSM_DEBUG_HISTORY
extern void
fsm_print_history(fsm_instance *fi);

extern void
fsm_record_history(fsm_instance *fi, int state, int event);
#endif

/**
 * Emits an event to a FSM.
 * If an action function is defined for the current state/event combination,
 * this function is called.
 *
 * @param fi    Pointer to FSM which should receive the event.
 * @param event The event do be delivered.
 * @param arg   A generic argument, handed to the action function.
 *
 * @return      0  on success,
 *              1  if current state or event is out of range
 *              !0 if state and event in range, but no action defined.
 */

static inline int fsm_event(fsm_instance *fi, int event, void *arg) { fsm_function_t r; int state = atomic_read(&fi->state); if ((state >= fi->f->nr_states) || (event >= fi->f->nr_events) ) { printk(KERN_ERR "fsm(%s): Invalid state st(%ld/%ld) ev(%d/%ld)\n", fi->name, (long)state,(long)fi->f->nr_states, event, (long)fi->f->nr_events); #if FSM_DEBUG_HISTORY fsm_print_history(fi); #endif return 1; } r = fi->f->jumpmatrix[fi->f->nr_states * event + state]; if (r) { #if FSM_DEBUG printk(KERN_DEBUG "fsm(%s): state %s event %s\n", fi->name, fi->f->state_names[state], fi->f->event_names[event]); #endif #if FSM_DEBUG_HISTORY fsm_record_history(fi, state, event); #endif r(fi, event, arg); return 0; } else { #if FSM_DEBUG || FSM_DEBUG_HISTORY printk(KERN_DEBUG "fsm(%s): no function for event %s in state %s\n", fi->name, fi->f->event_names[event], fi->f->state_names[state]); #endif #if FSM_DEBUG_HISTORY fsm_print_history(fi); #endif return !0; } }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds23899.17%150.00%
adrian bunkadrian bunk20.83%150.00%
Total240100.00%2100.00%

/** * Modifies the state of an FSM. * This does <em>not</em> trigger an event or calls an action function. * * @param fi Pointer to FSM * @param state The new state for this FSM. */
static inline void fsm_newstate(fsm_instance *fi, int newstate) { atomic_set(&fi->state,newstate); #if FSM_DEBUG_HISTORY fsm_record_history(fi, newstate, -1); #endif #if FSM_DEBUG printk(KERN_DEBUG "fsm(%s): New state %s\n", fi->name, fi->f->state_names[newstate]); #endif wake_up(&fi->wait_q); }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds6185.92%133.33%
frank blaschkafrank blaschka811.27%133.33%
adrian bunkadrian bunk22.82%133.33%
Total71100.00%3100.00%

/** * Retrieves the state of an FSM * * @param fi Pointer to FSM * * @return The current state of the FSM. */
static inline int fsm_getstate(fsm_instance *fi) { return atomic_read(&fi->state); }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds1890.00%150.00%
adrian bunkadrian bunk210.00%150.00%
Total20100.00%2100.00%

/** * Retrieves the name of the state of an FSM * * @param fi Pointer to FSM * * @return The current state of the FSM in a human readable form. */ extern const char *fsm_getstate_str(fsm_instance *fi); /** * Initializes a timer for an FSM. * This prepares an fsm_timer for usage with fsm_addtimer. * * @param fi Pointer to FSM * @param timer The timer to be initialized. */ extern void fsm_settimer(fsm_instance *fi, fsm_timer *); /** * Clears a pending timer of an FSM instance. * * @param timer The timer to clear. */ extern void fsm_deltimer(fsm_timer *timer); /** * Adds and starts a timer to an FSM instance. * * @param timer The timer to be added. The field fi of that timer * must have been set to point to the instance. * @param millisec Duration, after which the timer should expire. * @param event Event, to trigger if timer expires. * @param arg Generic argument, provided to expiry function. * * @return 0 on success, -1 if timer is already active. */ extern int fsm_addtimer(fsm_timer *timer, int millisec, int event, void *arg); /** * Modifies a timer of an FSM. * * @param timer The timer to modify. * @param millisec Duration, after which the timer should expire. * @param event Event, to trigger if timer expires. * @param arg Generic argument, provided to expiry function. */ extern void fsm_modtimer(fsm_timer *timer, int millisec, int event, void *arg); #endif /* _FSM_H_ */

Overall Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds67597.26%233.33%
frank blaschkafrank blaschka111.59%116.67%
adrian bunkadrian bunk60.86%116.67%
al viroal viro10.14%116.67%
arun sharmaarun sharma10.14%116.67%
Total694100.00%6100.00%
Directory: drivers/s390/net
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