1/*
2 * Copyright (c) 2016 Qualcomm Atheros, Inc
3 *
4 * GPL v2
5 *
6 * Based on net/sched/sch_fq_codel.c
7 */
8#ifndef __NET_SCHED_FQ_H
9#define __NET_SCHED_FQ_H
10
11struct fq_tin;
12
13/**
14 * struct fq_flow - per traffic flow queue
15 *
16 * @tin: owner of this flow. Used to manage collisions, i.e. when a packet
17 * hashes to an index which points to a flow that is already owned by a
18 * different tin the packet is destined to. In such case the implementer
19 * must provide a fallback flow
20 * @flowchain: can be linked to fq_tin's new_flows or old_flows. Used for DRR++
21 * (deficit round robin) based round robin queuing similar to the one
22 * found in net/sched/sch_fq_codel.c
23 * @backlogchain: can be linked to other fq_flow and fq. Used to keep track of
24 * fat flows and efficient head-dropping if packet limit is reached
25 * @queue: sk_buff queue to hold packets
26 * @backlog: number of bytes pending in the queue. The number of packets can be
27 * found in @queue.qlen
28 * @deficit: used for DRR++
29 */
30struct fq_flow {
31 struct fq_tin *tin;
32 struct list_head flowchain;
33 struct list_head backlogchain;
34 struct sk_buff_head queue;
35 u32 backlog;
36 int deficit;
37};
38
39/**
40 * struct fq_tin - a logical container of fq_flows
41 *
42 * Used to group fq_flows into a logical aggregate. DRR++ scheme is used to
43 * pull interleaved packets out of the associated flows.
44 *
45 * @new_flows: linked list of fq_flow
46 * @old_flows: linked list of fq_flow
47 */
48struct fq_tin {
49 struct list_head new_flows;
50 struct list_head old_flows;
51 u32 backlog_bytes;
52 u32 backlog_packets;
53 u32 overlimit;
54 u32 collisions;
55 u32 flows;
56 u32 tx_bytes;
57 u32 tx_packets;
58};
59
60/**
61 * struct fq - main container for fair queuing purposes
62 *
63 * @backlogs: linked to fq_flows. Used to maintain fat flows for efficient
64 * head-dropping when @backlog reaches @limit
65 * @limit: max number of packets that can be queued across all flows
66 * @backlog: number of packets queued across all flows
67 */
68struct fq {
69 struct fq_flow *flows;
70 struct list_head backlogs;
71 spinlock_t lock;
72 u32 flows_cnt;
73 u32 perturbation;
74 u32 limit;
75 u32 memory_limit;
76 u32 memory_usage;
77 u32 quantum;
78 u32 backlog;
79 u32 overlimit;
80 u32 overmemory;
81 u32 collisions;
82};
83
84typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
85 struct fq_tin *,
86 struct fq_flow *flow);
87
88typedef void fq_skb_free_t(struct fq *,
89 struct fq_tin *,
90 struct fq_flow *,
91 struct sk_buff *);
92
93/* Return %true to filter (drop) the frame. */
94typedef bool fq_skb_filter_t(struct fq *,
95 struct fq_tin *,
96 struct fq_flow *,
97 struct sk_buff *,
98 void *);
99
100typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
101 struct fq_tin *,
102 int idx,
103 struct sk_buff *);
104
105#endif
106