1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2016 Qualcomm Atheros, Inc
4 *
5 * Based on net/sched/sch_fq_codel.c
6 */
7 #ifndef __NET_SCHED_FQ_H
8 #define __NET_SCHED_FQ_H
9
10 struct fq_tin;
11
12 /**
13 * struct fq_flow - per traffic flow queue
14 *
15 * @tin: owner of this flow. Used to manage collisions, i.e. when a packet
16 * hashes to an index which points to a flow that is already owned by a
17 * different tin the packet is destined to. In such case the implementer
18 * must provide a fallback flow
19 * @flowchain: can be linked to fq_tin's new_flows or old_flows. Used for DRR++
20 * (deficit round robin) based round robin queuing similar to the one
21 * found in net/sched/sch_fq_codel.c
22 * @backlogchain: can be linked to other fq_flow and fq. Used to keep track of
23 * fat flows and efficient head-dropping if packet limit is reached
24 * @queue: sk_buff queue to hold packets
25 * @backlog: number of bytes pending in the queue. The number of packets can be
26 * found in @queue.qlen
27 * @deficit: used for DRR++
28 */
29 struct fq_flow {
30 struct fq_tin *tin;
31 struct list_head flowchain;
32 struct list_head backlogchain;
33 struct sk_buff_head queue;
34 u32 backlog;
35 int deficit;
36 };
37
38 /**
39 * struct fq_tin - a logical container of fq_flows
40 *
41 * Used to group fq_flows into a logical aggregate. DRR++ scheme is used to
42 * pull interleaved packets out of the associated flows.
43 *
44 * @new_flows: linked list of fq_flow
45 * @old_flows: linked list of fq_flow
46 */
47 struct fq_tin {
48 struct list_head new_flows;
49 struct list_head old_flows;
50 u32 backlog_bytes;
51 u32 backlog_packets;
52 u32 overlimit;
53 u32 collisions;
54 u32 flows;
55 u32 tx_bytes;
56 u32 tx_packets;
57 };
58
59 /**
60 * struct fq - main container for fair queuing purposes
61 *
62 * @backlogs: linked to fq_flows. Used to maintain fat flows for efficient
63 * head-dropping when @backlog reaches @limit
64 * @limit: max number of packets that can be queued across all flows
65 * @backlog: number of packets queued across all flows
66 */
67 struct fq {
68 struct fq_flow *flows;
69 struct list_head backlogs;
70 spinlock_t lock;
71 u32 flows_cnt;
72 siphash_key_t perturbation;
73 u32 limit;
74 u32 memory_limit;
75 u32 memory_usage;
76 u32 quantum;
77 u32 backlog;
78 u32 overlimit;
79 u32 overmemory;
80 u32 collisions;
81 };
82
83 typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
84 struct fq_tin *,
85 struct fq_flow *flow);
86
87 typedef void fq_skb_free_t(struct fq *,
88 struct fq_tin *,
89 struct fq_flow *,
90 struct sk_buff *);
91
92 /* Return %true to filter (drop) the frame. */
93 typedef bool fq_skb_filter_t(struct fq *,
94 struct fq_tin *,
95 struct fq_flow *,
96 struct sk_buff *,
97 void *);
98
99 typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
100 struct fq_tin *,
101 int idx,
102 struct sk_buff *);
103
104 #endif