include/net/fq.h

root/include/net/fq.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2016 Qualcomm Atheros, Inc
 *
 * Based on net/sched/sch_fq_codel.c
 */
#ifndef __NET_SCHED_FQ_H
#define __NET_SCHED_FQ_H

#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/types.h>

struct fq_tin;

/**
 * struct fq_flow - per traffic flow queue
 *
 * @tin: owner of this flow. Used to manage collisions, i.e. when a packet
 *      hashes to an index which points to a flow that is already owned by a
 *      different tin the packet is destined to. In such case the implementer
 *      must provide a fallback flow
 * @flowchain: can be linked to fq_tin's new_flows or old_flows. Used for DRR++
 *      (deficit round robin) based round robin queuing similar to the one
 *      found in net/sched/sch_fq_codel.c
 * @queue: sk_buff queue to hold packets
 * @backlog: number of bytes pending in the queue. The number of packets can be
 *      found in @queue.qlen
 * @deficit: used for DRR++
 */
struct fq_flow {
        struct fq_tin *tin;
        struct list_head flowchain;
        struct sk_buff_head queue;
        u32 backlog;
        int deficit;
};

/**
 * struct fq_tin - a logical container of fq_flows
 *
 * Used to group fq_flows into a logical aggregate. DRR++ scheme is used to
 * pull interleaved packets out of the associated flows.
 *
 * @new_flows: linked list of fq_flow
 * @old_flows: linked list of fq_flow
 */
struct fq_tin {
        struct list_head new_flows;
        struct list_head old_flows;
        struct list_head tin_list;
        struct fq_flow default_flow;
        u32 backlog_bytes;
        u32 backlog_packets;
        u32 overlimit;
        u32 collisions;
        u32 flows;
        u32 tx_bytes;
        u32 tx_packets;
};

/**
 * struct fq - main container for fair queuing purposes
 *
 * @limit: max number of packets that can be queued across all flows
 * @backlog: number of packets queued across all flows
 */
struct fq {
        struct fq_flow *flows;
        unsigned long *flows_bitmap;

        struct list_head tin_backlog;
        spinlock_t lock;
        u32 flows_cnt;
        u32 limit;
        u32 memory_limit;
        u32 memory_usage;
        u32 quantum;
        u32 backlog;
        u32 overlimit;
        u32 overmemory;
        u32 collisions;
};

typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
                                         struct fq_tin *,
                                         struct fq_flow *flow);

typedef void fq_skb_free_t(struct fq *,
                           struct fq_tin *,
                           struct fq_flow *,
                           struct sk_buff *);

/* Return %true to filter (drop) the frame. */
typedef bool fq_skb_filter_t(struct fq *,
                             struct fq_tin *,
                             struct fq_flow *,
                             struct sk_buff *,
                             void *);

#endif
Linux
