include/net/fq.h

   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
  11 struct 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  */
  30 struct 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  */
  48 struct 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  */
  68 struct fq {
  69         struct fq_flow *flows;
  70         struct list_head backlogs;
  71         spinlock_t lock;
  72         u32 flows_cnt;
  73         siphash_key_t   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
  84 typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
  85                                          struct fq_tin *,
  86                                          struct fq_flow *flow);
  87
  88 typedef void fq_skb_free_t(struct fq *,
  89                            struct fq_tin *,
  90                            struct fq_flow *,
  91                            struct sk_buff *);
  92
  93 typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
  94                                               struct fq_tin *,
  95                                               int idx,
  96                                               struct sk_buff *);
  97
  98 #endif