Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* Copyright (C) 2013 Cisco Systems, Inc, 2013.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Author: Vijay Subramanian <vijaynsu@cisco.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Author: Mythili Prabhu <mysuryan@cisco.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * ECN support is added by Naeem Khademi <naeemk@ifi.uio.no>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * University of Oslo, Norway.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * References:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * RFC 8033: https://tools.ietf.org/html/rfc8033
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <net/pkt_sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <net/inet_ecn.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <net/pie.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) /* private data for the Qdisc */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) struct pie_sched_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	struct pie_vars vars;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct pie_params params;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct pie_stats stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	struct timer_list adapt_timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	struct Qdisc *sch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) bool pie_drop_early(struct Qdisc *sch, struct pie_params *params,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 		    struct pie_vars *vars, u32 backlog, u32 packet_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	u64 rnd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	u64 local_prob = vars->prob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	u32 mtu = psched_mtu(qdisc_dev(sch));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	/* If there is still burst allowance left skip random early drop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	if (vars->burst_time > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	/* If current delay is less than half of target, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	 * if drop prob is low already, disable early_drop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	if ((vars->qdelay < params->target / 2) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	    (vars->prob < MAX_PROB / 5))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	/* If we have fewer than 2 mtu-sized packets, disable pie_drop_early,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	 * similar to min_th in RED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	if (backlog < 2 * mtu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	/* If bytemode is turned on, use packet size to compute new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	 * probablity. Smaller packets will have lower drop prob in this case
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	if (params->bytemode && packet_size <= mtu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 		local_prob = (u64)packet_size * div_u64(local_prob, mtu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		local_prob = vars->prob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (local_prob == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		vars->accu_prob = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		vars->accu_prob += local_prob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (vars->accu_prob < (MAX_PROB / 100) * 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	if (vars->accu_prob >= (MAX_PROB / 2) * 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	prandom_bytes(&rnd, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	if ((rnd >> BITS_PER_BYTE) < local_prob) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		vars->accu_prob = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) EXPORT_SYMBOL_GPL(pie_drop_early);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 			     struct sk_buff **to_free)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	bool enqueue = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	if (unlikely(qdisc_qlen(sch) >= sch->limit)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		q->stats.overlimit++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	if (!pie_drop_early(sch, &q->params, &q->vars, sch->qstats.backlog,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			    skb->len)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		enqueue = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	} else if (q->params.ecn && (q->vars.prob <= MAX_PROB / 10) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		   INET_ECN_set_ce(skb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		/* If packet is ecn capable, mark it if drop probability
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		 * is lower than 10%, else drop it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		q->stats.ecn_mark++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		enqueue = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	/* we can enqueue the packet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	if (enqueue) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		/* Set enqueue time only when dq_rate_estimator is disabled. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		if (!q->params.dq_rate_estimator)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 			pie_set_enqueue_time(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		q->stats.packets_in++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		if (qdisc_qlen(sch) > q->stats.maxq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			q->stats.maxq = qdisc_qlen(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		return qdisc_enqueue_tail(skb, sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	q->stats.dropped++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	q->vars.accu_prob = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	return qdisc_drop(skb, sch, to_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) static const struct nla_policy pie_policy[TCA_PIE_MAX + 1] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	[TCA_PIE_TARGET]		= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	[TCA_PIE_LIMIT]			= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	[TCA_PIE_TUPDATE]		= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	[TCA_PIE_ALPHA]			= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	[TCA_PIE_BETA]			= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	[TCA_PIE_ECN]			= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	[TCA_PIE_BYTEMODE]		= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	[TCA_PIE_DQ_RATE_ESTIMATOR]	= {.type = NLA_U32},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static int pie_change(struct Qdisc *sch, struct nlattr *opt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		      struct netlink_ext_ack *extack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	struct nlattr *tb[TCA_PIE_MAX + 1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	unsigned int qlen, dropped = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (!opt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	err = nla_parse_nested_deprecated(tb, TCA_PIE_MAX, opt, pie_policy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 					  NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	sch_tree_lock(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	/* convert from microseconds to pschedtime */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	if (tb[TCA_PIE_TARGET]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		/* target is in us */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		u32 target = nla_get_u32(tb[TCA_PIE_TARGET]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		/* convert to pschedtime */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		q->params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	/* tupdate is in jiffies */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	if (tb[TCA_PIE_TUPDATE])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		q->params.tupdate =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 			usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE]));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	if (tb[TCA_PIE_LIMIT]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		u32 limit = nla_get_u32(tb[TCA_PIE_LIMIT]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		q->params.limit = limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		sch->limit = limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	if (tb[TCA_PIE_ALPHA])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		q->params.alpha = nla_get_u32(tb[TCA_PIE_ALPHA]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	if (tb[TCA_PIE_BETA])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		q->params.beta = nla_get_u32(tb[TCA_PIE_BETA]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	if (tb[TCA_PIE_ECN])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		q->params.ecn = nla_get_u32(tb[TCA_PIE_ECN]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	if (tb[TCA_PIE_BYTEMODE])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		q->params.bytemode = nla_get_u32(tb[TCA_PIE_BYTEMODE]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	if (tb[TCA_PIE_DQ_RATE_ESTIMATOR])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		q->params.dq_rate_estimator =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 				nla_get_u32(tb[TCA_PIE_DQ_RATE_ESTIMATOR]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	/* Drop excess packets if new limit is lower */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	qlen = sch->q.qlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	while (sch->q.qlen > sch->limit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		dropped += qdisc_pkt_len(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		qdisc_qstats_backlog_dec(sch, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		rtnl_qdisc_drop(skb, sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	sch_tree_unlock(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 			 struct pie_vars *vars, u32 backlog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	psched_time_t now = psched_get_time();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	u32 dtime = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	/* If dq_rate_estimator is disabled, calculate qdelay using the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	 * packet timestamp.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	if (!params->dq_rate_estimator) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		vars->qdelay = now - pie_get_enqueue_time(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		if (vars->dq_tstamp != DTIME_INVALID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			dtime = now - vars->dq_tstamp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 		vars->dq_tstamp = now;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		if (backlog == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 			vars->qdelay = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		if (dtime == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		goto burst_allowance_reduction;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	/* If current queue is about 10 packets or more and dq_count is unset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	 * we have enough packets to calculate the drain rate. Save
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	 * current time as dq_tstamp and start measurement cycle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	if (backlog >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		vars->dq_tstamp = psched_get_time();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		vars->dq_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	/* Calculate the average drain rate from this value. If queue length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	 * has receded to a small value viz., <= QUEUE_THRESHOLD bytes, reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	 * the dq_count to -1 as we don't have enough packets to calculate the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	 * drain rate anymore. The following if block is entered only when we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	 * have a substantial queue built up (QUEUE_THRESHOLD bytes or more)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	 * and we calculate the drain rate for the threshold here.  dq_count is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	 * in bytes, time difference in psched_time, hence rate is in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	 * bytes/psched_time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	if (vars->dq_count != DQCOUNT_INVALID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		vars->dq_count += skb->len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		if (vars->dq_count >= QUEUE_THRESHOLD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 			u32 count = vars->dq_count << PIE_SCALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 			dtime = now - vars->dq_tstamp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 			if (dtime == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 				return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 			count = count / dtime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 			if (vars->avg_dq_rate == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 				vars->avg_dq_rate = count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 			else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 				vars->avg_dq_rate =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 				    (vars->avg_dq_rate -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 				     (vars->avg_dq_rate >> 3)) + (count >> 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 			/* If the queue has receded below the threshold, we hold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 			 * on to the last drain rate calculated, else we reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 			 * dq_count to 0 to re-enter the if block when the next
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 			 * packet is dequeued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 			if (backlog < QUEUE_THRESHOLD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 				vars->dq_count = DQCOUNT_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 				vars->dq_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 				vars->dq_tstamp = psched_get_time();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 			goto burst_allowance_reduction;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) burst_allowance_reduction:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	if (vars->burst_time > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		if (vars->burst_time > dtime)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 			vars->burst_time -= dtime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 			vars->burst_time = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) EXPORT_SYMBOL_GPL(pie_process_dequeue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 			       u32 backlog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	psched_time_t qdelay = 0;	/* in pschedtime */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	psched_time_t qdelay_old = 0;	/* in pschedtime */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	s64 delta = 0;		/* determines the change in probability */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	u64 oldprob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	u64 alpha, beta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	u32 power;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	bool update_prob = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	if (params->dq_rate_estimator) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 		qdelay_old = vars->qdelay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 		vars->qdelay_old = vars->qdelay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 		if (vars->avg_dq_rate > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 			qdelay = (backlog << PIE_SCALE) / vars->avg_dq_rate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 			qdelay = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		qdelay = vars->qdelay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		qdelay_old = vars->qdelay_old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	/* If qdelay is zero and backlog is not, it means backlog is very small,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	 * so we do not update probabilty in this round.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	if (qdelay == 0 && backlog != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		update_prob = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 	/* In the algorithm, alpha and beta are between 0 and 2 with typical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	 * value for alpha as 0.125. In this implementation, we use values 0-32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 	 * passed from user space to represent this. Also, alpha and beta have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	 * unit of HZ and need to be scaled before they can used to update
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	 * probability. alpha/beta are updated locally below by scaling down
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	 * by 16 to come to 0-2 range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	alpha = ((u64)params->alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	beta = ((u64)params->beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 	/* We scale alpha and beta differently depending on how heavy the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	 * congestion is. Please see RFC 8033 for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	if (vars->prob < MAX_PROB / 10) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 		alpha >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		beta >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 		power = 100;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 		while (vars->prob < div_u64(MAX_PROB, power) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 		       power <= 1000000) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 			alpha >>= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 			beta >>= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 			power *= 10;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	/* alpha and beta should be between 0 and 32, in multiples of 1/16 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 	delta += alpha * (qdelay - params->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	delta += beta * (qdelay - qdelay_old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 	oldprob = vars->prob;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	/* to ensure we increase probability in steps of no more than 2% */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	if (delta > (s64)(MAX_PROB / (100 / 2)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	    vars->prob >= MAX_PROB / 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 		delta = (MAX_PROB / 100) * 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	/* Non-linear drop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 	 * Tune drop probability to increase quickly for high delays(>= 250ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 	 * 250ms is derived through experiments and provides error protection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 	if (qdelay > (PSCHED_NS2TICKS(250 * NSEC_PER_MSEC)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 		delta += MAX_PROB / (100 / 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 	vars->prob += delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	if (delta > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 		/* prevent overflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 		if (vars->prob < oldprob) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 			vars->prob = MAX_PROB;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 			/* Prevent normalization error. If probability is at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 			 * maximum value already, we normalize it here, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 			 * skip the check to do a non-linear drop in the next
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 			 * section.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 			update_prob = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 		/* prevent underflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 		if (vars->prob > oldprob)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) 			vars->prob = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) 	/* Non-linear drop in probability: Reduce drop probability quickly if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 	 * delay is 0 for 2 consecutive Tupdate periods.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) 	if (qdelay == 0 && qdelay_old == 0 && update_prob)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 		/* Reduce drop probability to 98.4% */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 		vars->prob -= vars->prob / 64;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) 	vars->qdelay = qdelay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 	vars->backlog_old = backlog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) 	/* We restart the measurement cycle if the following conditions are met
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) 	 * 1. If the delay has been low for 2 consecutive Tupdate periods
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) 	 * 2. Calculated drop probability is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) 	 * 3. If average dq_rate_estimator is enabled, we have atleast one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) 	 *    estimate for the avg_dq_rate ie., is a non-zero value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) 	if ((vars->qdelay < params->target / 2) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) 	    (vars->qdelay_old < params->target / 2) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) 	    vars->prob == 0 &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) 	    (!params->dq_rate_estimator || vars->avg_dq_rate > 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) 		pie_vars_init(vars);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) 	if (!params->dq_rate_estimator)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) 		vars->qdelay_old = qdelay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) EXPORT_SYMBOL_GPL(pie_calculate_probability);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) static void pie_timer(struct timer_list *t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) 	struct pie_sched_data *q = from_timer(q, t, adapt_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) 	struct Qdisc *sch = q->sch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) 	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) 	spin_lock(root_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) 	pie_calculate_probability(&q->params, &q->vars, sch->qstats.backlog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) 	/* reset the timer to fire after 'tupdate'. tupdate is in jiffies. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) 	if (q->params.tupdate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) 		mod_timer(&q->adapt_timer, jiffies + q->params.tupdate);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) 	spin_unlock(root_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) static int pie_init(struct Qdisc *sch, struct nlattr *opt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) 		    struct netlink_ext_ack *extack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) 	pie_params_init(&q->params);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) 	pie_vars_init(&q->vars);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) 	sch->limit = q->params.limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) 	q->sch = sch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) 	timer_setup(&q->adapt_timer, pie_timer, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) 	if (opt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) 		int err = pie_change(sch, opt, extack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) 	mod_timer(&q->adapt_timer, jiffies + HZ / 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) static int pie_dump(struct Qdisc *sch, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) 	struct nlattr *opts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) 	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) 	if (!opts)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) 		goto nla_put_failure;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) 	/* convert target from pschedtime to us */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) 	if (nla_put_u32(skb, TCA_PIE_TARGET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) 			((u32)PSCHED_TICKS2NS(q->params.target)) /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) 			NSEC_PER_USEC) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) 	    nla_put_u32(skb, TCA_PIE_LIMIT, sch->limit) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) 	    nla_put_u32(skb, TCA_PIE_TUPDATE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) 			jiffies_to_usecs(q->params.tupdate)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) 	    nla_put_u32(skb, TCA_PIE_ALPHA, q->params.alpha) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) 	    nla_put_u32(skb, TCA_PIE_BETA, q->params.beta) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) 	    nla_put_u32(skb, TCA_PIE_ECN, q->params.ecn) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) 	    nla_put_u32(skb, TCA_PIE_BYTEMODE, q->params.bytemode) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) 	    nla_put_u32(skb, TCA_PIE_DQ_RATE_ESTIMATOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) 			q->params.dq_rate_estimator))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) 		goto nla_put_failure;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) 	return nla_nest_end(skb, opts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) nla_put_failure:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) 	nla_nest_cancel(skb, opts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) 	return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) 	struct tc_pie_xstats st = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) 		.prob		= q->vars.prob << BITS_PER_BYTE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) 		.delay		= ((u32)PSCHED_TICKS2NS(q->vars.qdelay)) /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) 				   NSEC_PER_USEC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) 		.packets_in	= q->stats.packets_in,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) 		.overlimit	= q->stats.overlimit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) 		.maxq		= q->stats.maxq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) 		.dropped	= q->stats.dropped,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) 		.ecn_mark	= q->stats.ecn_mark,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) 	/* avg_dq_rate is only valid if dq_rate_estimator is enabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) 	st.dq_rate_estimating = q->params.dq_rate_estimator;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) 	/* unscale and return dq_rate in bytes per sec */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) 	if (q->params.dq_rate_estimator)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) 		st.avg_dq_rate = q->vars.avg_dq_rate *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) 				 (PSCHED_TICKS_PER_SEC) >> PIE_SCALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) 	return gnet_stats_copy_app(d, &st, sizeof(st));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) static struct sk_buff *pie_qdisc_dequeue(struct Qdisc *sch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) 	struct sk_buff *skb = qdisc_dequeue_head(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) 	if (!skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) 	pie_process_dequeue(skb, &q->params, &q->vars, sch->qstats.backlog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) 	return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) static void pie_reset(struct Qdisc *sch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) 	qdisc_reset_queue(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) 	pie_vars_init(&q->vars);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) static void pie_destroy(struct Qdisc *sch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) 	struct pie_sched_data *q = qdisc_priv(sch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) 	q->params.tupdate = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) 	del_timer_sync(&q->adapt_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) static struct Qdisc_ops pie_qdisc_ops __read_mostly = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) 	.id		= "pie",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) 	.priv_size	= sizeof(struct pie_sched_data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) 	.enqueue	= pie_qdisc_enqueue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) 	.dequeue	= pie_qdisc_dequeue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) 	.peek		= qdisc_peek_dequeued,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) 	.init		= pie_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) 	.destroy	= pie_destroy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) 	.reset		= pie_reset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) 	.change		= pie_change,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) 	.dump		= pie_dump,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) 	.dump_stats	= pie_dump_stats,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) static int __init pie_module_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) 	return register_qdisc(&pie_qdisc_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) static void __exit pie_module_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) 	unregister_qdisc(&pie_qdisc_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) module_init(pie_module_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) module_exit(pie_module_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) MODULE_DESCRIPTION("Proportional Integral controller Enhanced (PIE) scheduler");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) MODULE_AUTHOR("Vijay Subramanian");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) MODULE_AUTHOR("Mythili Prabhu");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) MODULE_LICENSE("GPL");