/* * 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 struct sk_buff *fq_flow_dequeue(struct fq *fq, struct fq_flow *flow) { struct fq_tin *tin = flow->tin; struct fq_flow *i; struct sk_buff *skb; lockdep_assert_held(&fq->lock); skb = __skb_dequeue(&flow->queue); if (!skb) return NULL; tin->backlog_bytes -= skb->len; tin->backlog_packets--; flow->backlog -= skb->len; fq->backlog--; fq->memory_usage -= skb->truesize; 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); } 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 */ if ((head == &tin->new_flows) && !list_empty(&tin->old_flows)) { list_move_tail(&flow->flowchain, &tin->old_flows); } else { list_del_init(&flow->flowchain); flow->tin = NULL; } goto begin; } flow->deficit -= skb->len; tin->tx_bytes += skb->len; tin->tx_packets++; return skb; } static struct fq_flow *fq_flow_classify(struct fq *fq, struct fq_tin *tin, struct sk_buff *skb, fq_flow_get_default_t get_default_func) { struct fq_flow *flow; u32 hash; u32 idx; lockdep_assert_held(&fq->lock); hash = skb_get_hash_perturb(skb, fq->perturbation); idx = reciprocal_scale(hash, fq->flows_cnt); flow = &fq->flows[idx]; if (flow->tin && flow->tin != tin) { flow = get_default_func(fq, tin, idx, skb); tin->collisions++; fq->collisions++; } if (!flow->tin) tin->flows++; return flow; } static void fq_recalc_backlog(struct fq *fq, struct fq_tin *tin, struct fq_flow *flow) { struct fq_flow *i; if (list_empty(&flow->backlogchain)) list_add_tail(&flow->backlogchain, &fq->backlogs); i = flow; list_for_each_entry_continue_reverse(i, &fq->backlogs, backlogchain) if (i->backlog > flow->backlog) break; list_move(&flow->backlogchain, &i->backlogchain); } static void fq_tin_enqueue(struct fq *fq, struct fq_tin *tin, struct sk_buff *skb, fq_skb_free_t free_func, fq_flow_get_default_t get_default_func) { struct fq_flow *flow; lockdep_assert_held(&fq->lock); flow = fq_flow_classify(fq, tin, skb, get_default_func); flow->tin = tin; flow->backlog += skb->len; tin->backlog_bytes += skb->len; tin->backlog_packets++; fq->memory_usage += skb->truesize; fq->backlog++; fq_recalc_backlog(fq, tin, flow); if (list_empty(&flow->flowchain)) { flow->deficit = fq->quantum; list_add_tail(&flow->flowchain, &tin->new_flows); } __skb_queue_tail(&flow->queue, skb); if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) { flow = list_first_entry_or_null(&fq->backlogs, struct fq_flow, backlogchain); if (!flow) return; skb = fq_flow_dequeue(fq, flow); if (!skb) return; free_func(fq, flow->tin, flow, skb); flow->tin->overlimit++; fq->overlimit++; if (fq->memory_usage > fq->memory_limit) fq->overmemory++; } } static void fq_flow_reset(struct fq *fq, struct fq_flow *flow, fq_skb_free_t free_func) { struct sk_buff *skb; while ((skb = fq_flow_dequeue(fq, flow))) free_func(fq, flow->tin, flow, skb); if (!list_empty(&flow->flowchain)) list_del_init(&flow->flowchain); if (!list_empty(&flow->backlogchain)) list_del_init(&flow->backlogchain); flow->tin = NULL; WARN_ON_ONCE(flow->backlog); } static void fq_tin_reset(struct fq *fq, struct fq_tin *tin, fq_skb_free_t free_func) { struct list_head *head; struct fq_flow *flow; for (;;) { head = &tin->new_flows; if (list_empty(head)) { head = &tin->old_flows; if (list_empty(head)) break; } flow = list_first_entry(head, struct fq_flow, flowchain); fq_flow_reset(fq, flow, free_func); } WARN_ON_ONCE(tin->backlog_bytes); WARN_ON_ONCE(tin->backlog_packets); } static void fq_flow_init(struct fq_flow *flow) { INIT_LIST_HEAD(&flow->flowchain); INIT_LIST_HEAD(&flow->backlogchain); __skb_queue_head_init(&flow->queue); } static void fq_tin_init(struct fq_tin *tin) { INIT_LIST_HEAD(&tin->new_flows); INIT_LIST_HEAD(&tin->old_flows); } static int fq_init(struct fq *fq, int flows_cnt) { int i; memset(fq, 0, sizeof(fq[0])); INIT_LIST_HEAD(&fq->backlogs); spin_lock_init(&fq->lock); fq->flows_cnt = max_t(u32, flows_cnt, 1); fq->perturbation = prandom_u32(); fq->quantum = 300; fq->limit = 8192; fq->memory_limit = 16 << 20; /* 16 MBytes */ fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL); if (!fq->flows) return -ENOMEM; for (i = 0; i < fq->flows_cnt; i++) fq_flow_init(&fq->flows[i]); return 0; } static void fq_reset(struct fq *fq, fq_skb_free_t free_func) { int i; for (i = 0; i < fq->flows_cnt; i++) fq_flow_reset(fq, &fq->flows[i], free_func); kfree(fq->flows); fq->flows = NULL; } #endif