/* SPDX-License-Identifier: GPL-2.0-only *//* * Copyright (c) 2016 Qualcomm Atheros, Inc * * 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, unsigned int packets,		    unsigned int bytes, unsigned int truesize){	struct fq_tin *tin = flow->tin;	int idx; 	tin->backlog_bytes -= bytes;	tin->backlog_packets -= packets;	flow->backlog -= bytes;	fq->backlog -= packets;	fq->memory_usage -= truesize; 	if (flow->backlog)		return; 	if (flow == &tin->default_flow) {		list_del_init(&tin->tin_list);		return;	} 	idx = flow - fq->flows;	__clear_bit(idx, fq->flows_bitmap);} static void fq_adjust_removal(struct fq *fq,			      struct fq_flow *flow,			      struct sk_buff *skb){	__fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize);} 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); 	return skb;} static int fq_flow_drop(struct fq *fq, struct fq_flow *flow,			fq_skb_free_t free_func){	unsigned int packets = 0, bytes = 0, truesize = 0;	struct fq_tin *tin = flow->tin;	struct sk_buff *skb;	int pending; 	lockdep_assert_held(&fq->lock); 	pending = min_t(int, 32, skb_queue_len(&flow->queue) / 2);	do {		skb = __skb_dequeue(&flow->queue);		if (!skb)			break; 		packets++;		bytes += skb->len;		truesize += skb->truesize;		free_func(fq, tin, flow, skb);	} while (packets < pending); 	__fq_adjust_removal(fq, flow, packets, bytes, truesize); 	return packets;} 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(skb); 	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){	struct fq_flow *flow; 	lockdep_assert_held(&fq->lock); 	flow = &fq->flows[idx];	if (flow->tin && flow->tin != tin) {		flow = &tin->default_flow;		tin->collisions++;		fq->collisions++;	} 	if (!flow->tin)		tin->flows++; 	return flow;} static struct fq_flow *fq_find_fattest_flow(struct fq *fq){	struct fq_tin *tin;	struct fq_flow *flow = NULL;	u32 len = 0;	int i; 	for_each_set_bit(i, fq->flows_bitmap, fq->flows_cnt) {		struct fq_flow *cur = &fq->flows[i];		unsigned int cur_len; 		cur_len = cur->backlog;		if (cur_len <= len)			continue; 		flow = cur;		len = cur_len;	} 	list_for_each_entry(tin, &fq->tin_backlog, tin_list) {		unsigned int cur_len = tin->default_flow.backlog; 		if (cur_len <= len)			continue; 		flow = &tin->default_flow;		len = cur_len;	} 	return flow;} static void fq_tin_enqueue(struct fq *fq,			   struct fq_tin *tin, u32 idx,			   struct sk_buff *skb,			   fq_skb_free_t free_func){	struct fq_flow *flow;	struct sk_buff *next;	bool oom; 	lockdep_assert_held(&fq->lock); 	flow = fq_flow_classify(fq, tin, idx, skb); 	if (!flow->backlog) {		if (flow != &tin->default_flow)			__set_bit(idx, fq->flows_bitmap);		else if (list_empty(&tin->tin_list))			list_add(&tin->tin_list, &fq->tin_backlog);	} 	flow->tin = tin;	skb_list_walk_safe(skb, skb, next) {		skb_mark_not_on_list(skb);		flow->backlog += skb->len;		tin->backlog_bytes += skb->len;		tin->backlog_packets++;		fq->memory_usage += skb->truesize;		fq->backlog++;		__skb_queue_tail(&flow->queue, skb);	} 	if (list_empty(&flow->flowchain)) {		flow->deficit = fq->quantum;		list_add_tail(&flow->flowchain,			      &tin->new_flows);	} 	oom = (fq->memory_usage > fq->memory_limit);	while (fq->backlog > fq->limit || oom) {		flow = fq_find_fattest_flow(fq);		if (!flow)			return; 		if (!fq_flow_drop(fq, flow, free_func))			return; 		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);	}} 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 fq_tin *tin = flow->tin;	struct sk_buff *skb; 	while ((skb = fq_flow_dequeue(fq, flow)))		free_func(fq, tin, flow, skb); 	if (!list_empty(&flow->flowchain)) {		list_del_init(&flow->flowchain);		if (list_empty(&tin->new_flows) &&		    list_empty(&tin->old_flows))			list_del_init(&tin->tin_list);	} 	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(!list_empty(&tin->tin_list));	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);	__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);	INIT_LIST_HEAD(&tin->tin_list);	fq_flow_init(&tin->default_flow);} static int fq_init(struct fq *fq, int flows_cnt){	int i; 	memset(fq, 0, sizeof(fq[0]));	spin_lock_init(&fq->lock);	INIT_LIST_HEAD(&fq->tin_backlog);	fq->flows_cnt = max_t(u32, flows_cnt, 1);	fq->quantum = 300;	fq->limit = 8192;	fq->memory_limit = 16 << 20; /* 16 MBytes */ 	fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);	if (!fq->flows)		return -ENOMEM; 	fq->flows_bitmap = bitmap_zalloc(fq->flows_cnt, GFP_KERNEL);	if (!fq->flows_bitmap) {		kvfree(fq->flows);		fq->flows = NULL;		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); 	kvfree(fq->flows);	fq->flows = NULL; 	bitmap_free(fq->flows_bitmap);	fq->flows_bitmap = NULL;} #endif