Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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_ */