net/sched/sch_fifo.c

19 static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch,
22 	if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
23 		   READ_ONCE(sch->limit)))
24 		return qdisc_enqueue_tail(skb, sch);
26 	return qdisc_drop(skb, sch, to_free);
29 static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch,
32 	if (likely(sch->q.qlen < READ_ONCE(sch->limit)))
33 		return qdisc_enqueue_tail(skb, sch);
35 	return qdisc_drop(skb, sch, to_free);
38 static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch,
43 	if (likely(sch->q.qlen < READ_ONCE(sch->limit)))
44 		return qdisc_enqueue_tail(skb, sch);
46 	prev_backlog = sch->qstats.backlog;
48 	__qdisc_queue_drop_head(sch, &sch->q, to_free);
49 	qdisc_qstats_drop(sch);
50 	qdisc_enqueue_tail(skb, sch);
52 	qdisc_tree_reduce_backlog(sch, 0, prev_backlog - sch->qstats.backlog);
56 static void fifo_offload_init(struct Qdisc *sch)
58 	struct net_device *dev = qdisc_dev(sch);
65 	qopt.handle = sch->handle;
66 	qopt.parent = sch->parent;
70 static void fifo_offload_destroy(struct Qdisc *sch)
72 	struct net_device *dev = qdisc_dev(sch);
79 	qopt.handle = sch->handle;
80 	qopt.parent = sch->parent;
84 static int fifo_offload_dump(struct Qdisc *sch)
89 	qopt.handle = sch->handle;
90 	qopt.parent = sch->parent;
91 	qopt.stats.bstats = &sch->bstats;
92 	qopt.stats.qstats = &sch->qstats;
94 	return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_FIFO, &qopt);
97 static int __fifo_init(struct Qdisc *sch, struct nlattr *opt,
101 	bool is_bfifo = sch->ops == &bfifo_qdisc_ops;
104 		u32 limit = qdisc_dev(sch)->tx_queue_len;
107 			limit *= psched_mtu(qdisc_dev(sch));
109 		WRITE_ONCE(sch->limit, limit);
116 		WRITE_ONCE(sch->limit, ctl->limit);
120 		bypass = sch->limit >= psched_mtu(qdisc_dev(sch));
122 		bypass = sch->limit >= 1;
125 		sch->flags |= TCQ_F_CAN_BYPASS;
127 		sch->flags &= ~TCQ_F_CAN_BYPASS;
132 static int fifo_init(struct Qdisc *sch, struct nlattr *opt,
137 	err = __fifo_init(sch, opt, extack);
141 	fifo_offload_init(sch);
145 static int fifo_hd_init(struct Qdisc *sch, struct nlattr *opt,
148 	return __fifo_init(sch, opt, extack);
151 static void fifo_destroy(struct Qdisc *sch)
153 	fifo_offload_destroy(sch);
156 static int __fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
158 	struct tc_fifo_qopt opt = { .limit = READ_ONCE(sch->limit) };
168 static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
172 	err = fifo_offload_dump(sch);
176 	return __fifo_dump(sch, skb);
179 static int fifo_hd_dump(struct Qdisc *sch, struct sk_buff *skb)
181 	return __fifo_dump(sch, skb);
253 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
260 	q = qdisc_create_dflt(sch->dev_queue, ops, TC_H_MAKE(sch->handle, 1),