/*
* Copyright (c) 2016 Qualcomm Atheros, Inc
*
* GPL v2
*
* Based on net/sched/sch_fq_codel.c
*/
#ifndef __NET_SCHED_FQ_H
#define __NET_SCHED_FQ_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
* @backlogchain: can be linked to other fq_flow and fq. Used to keep track of
* fat flows and efficient head-dropping if packet limit is reached
* @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 list_head backlogchain;
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;
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
*
* @backlogs: linked to fq_flows. Used to maintain fat flows for efficient
* head-dropping when @backlog reaches @limit
* @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;
struct list_head backlogs;
spinlock_t lock;
u32 flows_cnt;
u32 perturbation;
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 *);
typedef struct fq_flow *fq_flow_get_default_t(struct fq *,
struct fq_tin *,
int idx,
struct sk_buff *);
#endif
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