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 #include <linux/skbuff.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/types.h>
  13
  14 struct fq_tin;
  15
  16 /**
  17  * struct fq_flow - per traffic flow queue
  18  *
  19  * @tin: owner of this flow. Used to manage collisions, i.e. when a packet
  20  *      hashes to an index which points to a flow that is already owned by a
  21  *      different tin the packet is destined to. In such case the implementer
  22  *      must provide a fallback flow
  23  * @flowchain: can be linked to fq_tin's new_flows or old_flows. Used for DRR++
  24  *      (deficit round robin) based round robin queuing similar to the one
  25  *      found in net/sched/sch_fq_codel.c
  26  * @queue: sk_buff queue to hold packets
  27  * @backlog: number of bytes pending in the queue. The number of packets can be
  28  *      found in @queue.qlen
  29  * @deficit: used for DRR++
  30  */
  31 struct fq_flow {
  32         struct fq_tin *tin;
  33         struct list_head flowchain;
  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         struct list_head tin_list;
  52         struct fq_flow default_flow;
  53         u32 backlog_bytes;
  54         u32 backlog_packets;
  55         u32 overlimit;
  56         u32 collisions;
  57         u32 flows;
  58         u32 tx_bytes;
  59         u32 tx_packets;
  60 };
  61
  62 /**
  63  * struct fq - main container for fair queuing purposes
  64  *
  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         unsigned long *flows_bitmap;
  71
  72         struct list_head tin_backlog;
  73         spinlock_t lock;
  74         u32 flows_cnt;
  75         u32 limit;
  76         u32 memory_limit;
  77         u32 memory_usage;
  78         u32 quantum;
  79         u32 backlog;
  80         u32 overlimit;
  81         u32 overmemory;
  82         u32 collisions;
  83 };
  84
  85 typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
  86                                          struct fq_tin *,
  87                                          struct fq_flow *flow);
  88
  89 typedef void fq_skb_free_t(struct fq *,
  90                            struct fq_tin *,
  91                            struct fq_flow *,
  92                            struct sk_buff *);
  93
  94 /* Return %true to filter (drop) the frame. */
  95 typedef bool fq_skb_filter_t(struct fq *,
  96                              struct fq_tin *,
  97                              struct fq_flow *,
  98                              struct sk_buff *,
  99                              void *);
 100
 101 #endif