include/net/fq.h

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