linux-imx

/*

 * Copyright (c) 2016 Qualcomm Atheros, Inc

 *

 * GPL v2

 *

 * Based on net/sched/sch_fq_codel.c

 */

#ifndef __NET_SCHED_FQ_IMPL_H

#define __NET_SCHED_FQ_IMPL_H

​

#include <net/fq.h>

​

/* functions that are embedded into includer */

​

static void fq_adjust_removal(struct fq *fq,

                  struct fq_flow *flow,

                  struct sk_buff *skb)

{

    struct fq_tin *tin = flow->tin;

​

    tin->backlog_bytes -= skb->len;

    tin->backlog_packets--;

    flow->backlog -= skb->len;

    fq->backlog--;

    fq->memory_usage -= skb->truesize;

}

​

static void fq_rejigger_backlog(struct fq *fq, struct fq_flow *flow)

{

    struct fq_flow *i;

​

    if (flow->backlog == 0) {

        list_del_init(&flow->backlogchain);

    } else {

        i = flow;

​

        list_for_each_entry_continue(i, &fq->backlogs, backlogchain)

            if (i->backlog < flow->backlog)

                break;

​

        list_move_tail(&flow->backlogchain,

                   &i->backlogchain);

    }

}

​

static struct sk_buff *fq_flow_dequeue(struct fq *fq,

                       struct fq_flow *flow)

{

    struct sk_buff *skb;

​

    lockdep_assert_held(&fq->lock);

​

    skb = __skb_dequeue(&flow->queue);

    if (!skb)

        return NULL;

​

    fq_adjust_removal(fq, flow, skb);

    fq_rejigger_backlog(fq, flow);

​

    return skb;

}

​

static struct sk_buff *fq_tin_dequeue(struct fq *fq,

                      struct fq_tin *tin,

                      fq_tin_dequeue_t dequeue_func)

{

    struct fq_flow *flow;

    struct list_head *head;

    struct sk_buff *skb;

​

    lockdep_assert_held(&fq->lock);

​

begin:

    head = &tin->new_flows;

    if (list_empty(head)) {

        head = &tin->old_flows;

        if (list_empty(head))

            return NULL;

    }

​

    flow = list_first_entry(head, struct fq_flow, flowchain);

​

    if (flow->deficit <= 0) {

        flow->deficit += fq->quantum;

        list_move_tail(&flow->flowchain,

                   &tin->old_flows);

        goto begin;

    }

​

    skb = dequeue_func(fq, tin, flow);

    if (!skb) {

        /* force a pass through old_flows to prevent starvation */