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