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
 14struct 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 */
 31struct 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 */
 48struct 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 */
 68struct 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
 85typedef struct sk_buff *fq_tin_dequeue_t(struct fq *,
 86					 struct fq_tin *,
 87					 struct fq_flow *flow);
 88
 89typedef 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. */
 95typedef bool fq_skb_filter_t(struct fq *,
 96			     struct fq_tin *,
 97			     struct fq_flow *,
 98			     struct sk_buff *,
 99			     void *);
100
101#endif