1 // SPDX-License-Identifier: GPL-2.0-only
20 /* Default values of the Veno variables, in fixed-point representation
24 static const int beta = 3 << V_PARAM_SHIFT;  variable
36 /* There are several situations when we must "re-start" Veno:
45 static inline void veno_enable(struct sock *sk)  in veno_enable()
50 	veno->doing_veno_now = 1;  in veno_enable()
52 	veno->minrtt = 0x7fffffff;  in veno_enable()
55 static inline void veno_disable(struct sock *sk)  in veno_disable()
60 	veno->doing_veno_now = 0;  in veno_disable()
63 static void tcp_veno_init(struct sock *sk)  in tcp_veno_init()
67 	veno->basertt = 0x7fffffff;  in tcp_veno_init()
68 	veno->inc = 1;  in tcp_veno_init()
73 static void tcp_veno_pkts_acked(struct sock *sk,  in tcp_veno_pkts_acked()
79 	if (sample->rtt_us < 0)  in tcp_veno_pkts_acked()
83 	vrtt = sample->rtt_us + 1;  in tcp_veno_pkts_acked()
86 	if (vrtt < veno->basertt)  in tcp_veno_pkts_acked()
87 		veno->basertt = vrtt;  in tcp_veno_pkts_acked()
92 	veno->minrtt = min(veno->minrtt, vrtt);  in tcp_veno_pkts_acked()
93 	veno->cntrtt++;  in tcp_veno_pkts_acked()
96 static void tcp_veno_state(struct sock *sk, u8 ca_state)  in tcp_veno_state()
113 static void tcp_veno_cwnd_event(struct sock *sk, enum tcp_ca_event event)  in tcp_veno_cwnd_event()
119 static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked)  in tcp_veno_cong_avoid()
124 	if (!veno->doing_veno_now) {  in tcp_veno_cong_avoid()
134 	if (veno->cntrtt <= 2) {  in tcp_veno_cong_avoid()
147 		rtt = veno->minrtt;  in tcp_veno_cong_avoid()
149 		target_cwnd = (u64)tcp_snd_cwnd(tp) * veno->basertt;  in tcp_veno_cong_avoid()
153 		veno->diff = (tcp_snd_cwnd(tp) << V_PARAM_SHIFT) - target_cwnd;  in tcp_veno_cong_avoid()
163 		if (veno->diff < beta) {  in tcp_veno_cong_avoid()
164 			/* In the "non-congestive state", increase cwnd  in tcp_veno_cong_avoid()
172 			if (tp->snd_cwnd_cnt >= tcp_snd_cwnd(tp)) {  in tcp_veno_cong_avoid()
173 				if (veno->inc &&  in tcp_veno_cong_avoid()
174 				    tcp_snd_cwnd(tp) < tp->snd_cwnd_clamp) {  in tcp_veno_cong_avoid()
176 					veno->inc = 0;  in tcp_veno_cong_avoid()
178 					veno->inc = 1;  in tcp_veno_cong_avoid()
179 				tp->snd_cwnd_cnt = 0;  in tcp_veno_cong_avoid()
181 				tp->snd_cwnd_cnt += acked;  in tcp_veno_cong_avoid()
186 		else if (tcp_snd_cwnd(tp) > tp->snd_cwnd_clamp)  in tcp_veno_cong_avoid()
187 			tcp_snd_cwnd_set(tp, tp->snd_cwnd_clamp);  in tcp_veno_cong_avoid()
190 	/* veno->cntrtt = 0; */  in tcp_veno_cong_avoid()
191 	veno->minrtt = 0x7fffffff;  in tcp_veno_cong_avoid()
195 static u32 tcp_veno_ssthresh(struct sock *sk)  in tcp_veno_ssthresh()
200 	if (veno->diff < beta)  in tcp_veno_ssthresh()
201 		/* in "non-congestive state", cut cwnd by 1/5 */  in tcp_veno_ssthresh()
208 static struct tcp_congestion_ops tcp_veno __read_mostly = {
221 static int __init tcp_veno_register(void)  in tcp_veno_register()
228 static void __exit tcp_veno_unregister(void)  in tcp_veno_unregister()