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
93typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
94					      struct fq_tin *,
95					      int idx,
96					      struct sk_buff *);
97
98#endif