diff options
Diffstat (limited to 'drivers/s390/net/fsm.h')
| -rw-r--r-- | drivers/s390/net/fsm.h | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/s390/net/fsm.h b/drivers/s390/net/fsm.h new file mode 100644 index 000000000..16dc071a2 --- /dev/null +++ b/drivers/s390/net/fsm.h @@ -0,0 +1,266 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#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; + } +} + +/** + * 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); +} + +/** + * 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); +} + +/** + * 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_ */ |