LXR linux/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
  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
  99