include/net/fq_impl.h - linux - Git at Google

 /*
  * 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 */
 		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 u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb)
 {
 	u32 hash = skb_get_hash_perturb(skb, fq->perturbation);

 	return reciprocal_scale(hash, fq->flows_cnt);
 }

 static struct fq_flow *fq_flow_classify(struct fq *fq,
 					struct fq_tin *tin, u32 idx,
 					struct sk_buff *skb,
 					fq_flow_get_default_t get_default_func)
 {
 	struct fq_flow *flow;

 	lockdep_assert_held(&fq->lock);

 	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, u32 idx,
 			   struct sk_buff *skb,
 			   fq_skb_free_t free_func,
 			   fq_flow_get_default_t get_default_func)
 {
 	struct fq_flow *flow;
 	bool oom;

 	lockdep_assert_held(&fq->lock);

 	flow = fq_flow_classify(fq, tin, idx, 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);
 	oom = (fq->memory_usage > fq->memory_limit);
 	while (fq->backlog > fq->limit || oom) {
 		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 (oom) {
 			fq->overmemory++;
 			oom = (fq->memory_usage > fq->memory_limit);
 		}
 	}
 }

 static void fq_flow_filter(struct fq *fq,
 			   struct fq_flow *flow,
 			   fq_skb_filter_t filter_func,
 			   void *filter_data,
 			   fq_skb_free_t free_func)
 {
 	struct fq_tin *tin = flow->tin;
 	struct sk_buff *skb, *tmp;

 	lockdep_assert_held(&fq->lock);

 	skb_queue_walk_safe(&flow->queue, skb, tmp) {
 		if (!filter_func(fq, tin, flow, skb, filter_data))
 			continue;

 		__skb_unlink(skb, &flow->queue);
 		fq_adjust_removal(fq, flow, skb);
 		free_func(fq, tin, flow, skb);
 	}

 	fq_rejigger_backlog(fq, flow);
 }

 static void fq_tin_filter(struct fq *fq,
 			  struct fq_tin *tin,
 			  fq_skb_filter_t filter_func,
 			  void *filter_data,
 			  fq_skb_free_t free_func)
 {
 	struct fq_flow *flow;

 	lockdep_assert_held(&fq->lock);

 	list_for_each_entry(flow, &tin->new_flows, flowchain)
 		fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
 	list_for_each_entry(flow, &tin->old_flows, flowchain)
 		fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
 }

 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
	/*
	* 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 */
	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 u32 fq_flow_idx(struct fq fq, struct sk_buff skb)
	{
	u32 hash = skb_get_hash_perturb(skb, fq->perturbation);

	return reciprocal_scale(hash, fq->flows_cnt);
	}

	static struct fq_flow fq_flow_classify(struct fq fq,
	struct fq_tin *tin, u32 idx,
	struct sk_buff *skb,
	fq_flow_get_default_t get_default_func)
	{
	struct fq_flow *flow;

	lockdep_assert_held(&fq->lock);

	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, u32 idx,
	struct sk_buff *skb,
	fq_skb_free_t free_func,
	fq_flow_get_default_t get_default_func)
	{
	struct fq_flow *flow;
	bool oom;

	lockdep_assert_held(&fq->lock);

	flow = fq_flow_classify(fq, tin, idx, 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);
	oom = (fq->memory_usage > fq->memory_limit);
	while (fq->backlog > fq->limit \|\| oom) {
	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 (oom) {
	fq->overmemory++;
	oom = (fq->memory_usage > fq->memory_limit);
	}
	}
	}

	static void fq_flow_filter(struct fq *fq,
	struct fq_flow *flow,
	fq_skb_filter_t filter_func,
	void *filter_data,
	fq_skb_free_t free_func)
	{
	struct fq_tin *tin = flow->tin;
	struct sk_buff skb, tmp;

	lockdep_assert_held(&fq->lock);

	skb_queue_walk_safe(&flow->queue, skb, tmp) {
	if (!filter_func(fq, tin, flow, skb, filter_data))
	continue;

	__skb_unlink(skb, &flow->queue);
	fq_adjust_removal(fq, flow, skb);
	free_func(fq, tin, flow, skb);
	}

	fq_rejigger_backlog(fq, flow);
	}

	static void fq_tin_filter(struct fq *fq,
	struct fq_tin *tin,
	fq_skb_filter_t filter_func,
	void *filter_data,
	fq_skb_free_t free_func)
	{
	struct fq_flow *flow;

	lockdep_assert_held(&fq->lock);

	list_for_each_entry(flow, &tin->new_flows, flowchain)
	fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
	list_for_each_entry(flow, &tin->old_flows, flowchain)
	fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
	}

	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