xref: /openbmc/linux/include/net/fq.h (revision 63705da3)
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  * @queue: sk_buff queue to hold packets
23  * @backlog: number of bytes pending in the queue. The number of packets can be
24  *	found in @queue.qlen
25  * @deficit: used for DRR++
26  */
27 struct fq_flow {
28 	struct fq_tin *tin;
29 	struct list_head flowchain;
30 	struct sk_buff_head queue;
31 	u32 backlog;
32 	int deficit;
33 };
34 
35 /**
36  * struct fq_tin - a logical container of fq_flows
37  *
38  * Used to group fq_flows into a logical aggregate. DRR++ scheme is used to
39  * pull interleaved packets out of the associated flows.
40  *
41  * @new_flows: linked list of fq_flow
42  * @old_flows: linked list of fq_flow
43  */
44 struct fq_tin {
45 	struct list_head new_flows;
46 	struct list_head old_flows;
47 	struct list_head tin_list;
48 	struct fq_flow default_flow;
49 	u32 backlog_bytes;
50 	u32 backlog_packets;
51 	u32 overlimit;
52 	u32 collisions;
53 	u32 flows;
54 	u32 tx_bytes;
55 	u32 tx_packets;
56 };
57 
58 /**
59  * struct fq - main container for fair queuing purposes
60  *
61  * @limit: max number of packets that can be queued across all flows
62  * @backlog: number of packets queued across all flows
63  */
64 struct fq {
65 	struct fq_flow *flows;
66 	unsigned long *flows_bitmap;
67 
68 	struct list_head tin_backlog;
69 	spinlock_t lock;
70 	u32 flows_cnt;
71 	u32 limit;
72 	u32 memory_limit;
73 	u32 memory_usage;
74 	u32 quantum;
75 	u32 backlog;
76 	u32 overlimit;
77 	u32 overmemory;
78 	u32 collisions;
79 };
80 
81 typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
82 					 struct fq_tin *,
83 					 struct fq_flow *flow);
84 
85 typedef void fq_skb_free_t(struct fq *,
86 			   struct fq_tin *,
87 			   struct fq_flow *,
88 			   struct sk_buff *);
89 
90 /* Return %true to filter (drop) the frame. */
91 typedef bool fq_skb_filter_t(struct fq *,
92 			     struct fq_tin *,
93 			     struct fq_flow *,
94 			     struct sk_buff *,
95 			     void *);
96 
97 typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
98 					      struct fq_tin *,
99 					      int idx,
100 					      struct sk_buff *);
101 
102 #endif
103