1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  linux/include/linux/sunrpc/timer.h
4  *
5  *  Declarations for the RPC transport timer.
6  *
7  *  Copyright (C) 2002 Trond Myklebust <trond.myklebust@fys.uio.no>
8  */
9 
10 #ifndef _LINUX_SUNRPC_TIMER_H
11 #define _LINUX_SUNRPC_TIMER_H
12 
13 #include <linux/atomic.h>
14 
15 struct rpc_rtt {
16 	unsigned long timeo;	/* default timeout value */
17 	unsigned long srtt[5];	/* smoothed round trip time << 3 */
18 	unsigned long sdrtt[5];	/* smoothed medium deviation of RTT */
19 	int ntimeouts[5];	/* Number of timeouts for the last request */
20 };
21 
22 
23 extern void rpc_init_rtt(struct rpc_rtt *rt, unsigned long timeo);
24 extern void rpc_update_rtt(struct rpc_rtt *rt, unsigned timer, long m);
25 extern unsigned long rpc_calc_rto(struct rpc_rtt *rt, unsigned timer);
26 
rpc_set_timeo(struct rpc_rtt * rt,int timer,int ntimeo)27 static inline void rpc_set_timeo(struct rpc_rtt *rt, int timer, int ntimeo)
28 {
29 	int *t;
30 	if (!timer)
31 		return;
32 	t = &rt->ntimeouts[timer-1];
33 	if (ntimeo < *t) {
34 		if (*t > 0)
35 			(*t)--;
36 	} else {
37 		if (ntimeo > 8)
38 			ntimeo = 8;
39 		*t = ntimeo;
40 	}
41 }
42 
rpc_ntimeo(struct rpc_rtt * rt,int timer)43 static inline int rpc_ntimeo(struct rpc_rtt *rt, int timer)
44 {
45 	if (!timer)
46 		return 0;
47 	return rt->ntimeouts[timer-1];
48 }
49 
50 #endif /* _LINUX_SUNRPC_TIMER_H */
51