[deliverable/linux.git] / include / net / fq_impl.h

/*
 * 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--;

	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->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) {
		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++;
	}
}

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->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
Commit	Line	Data
557fc4a0 MK	1	/*
	2	* Copyright (c) 2016 Qualcomm Atheros, Inc
	3	*
	4	* GPL v2
	5	*
	6	* Based on net/sched/sch_fq_codel.c
	7	*/
	8	#ifndef __NET_SCHED_FQ_IMPL_H
	9	#define __NET_SCHED_FQ_IMPL_H
	10
	11	#include <net/fq.h>
	12
	13	/* functions that are embedded into includer */
	14
	15	static struct sk_buff fq_flow_dequeue(struct fq fq,
	16	struct fq_flow *flow)
	17	{
	18	struct fq_tin *tin = flow->tin;
	19	struct fq_flow *i;
	20	struct sk_buff *skb;
	21
	22	lockdep_assert_held(&fq->lock);
	23
	24	skb = __skb_dequeue(&flow->queue);
	25	if (!skb)
	26	return NULL;
	27
	28	tin->backlog_bytes -= skb->len;
	29	tin->backlog_packets--;
	30	flow->backlog -= skb->len;
	31	fq->backlog--;
	32
	33	if (flow->backlog == 0) {
	34	list_del_init(&flow->backlogchain);
	35	} else {
	36	i = flow;
	37
	38	list_for_each_entry_continue(i, &fq->backlogs, backlogchain)
	39	if (i->backlog < flow->backlog)
	40	break;
	41
	42	list_move_tail(&flow->backlogchain,
	43	&i->backlogchain);
	44	}
	45
	46	return skb;
	47	}
	48
	49	static struct sk_buff fq_tin_dequeue(struct fq fq,
	50	struct fq_tin *tin,
	51	fq_tin_dequeue_t dequeue_func)
	52	{
	53	struct fq_flow *flow;
	54	struct list_head *head;
	55	struct sk_buff *skb;
	56
	57	lockdep_assert_held(&fq->lock);
	58
	59	begin:
	60	head = &tin->new_flows;
	61	if (list_empty(head)) {
	62	head = &tin->old_flows;
	63	if (list_empty(head))
	64	return NULL;
65	}
66
67	flow = list_first_entry(head, struct fq_flow, flowchain);
68
69	if (flow->deficit <= 0) {
70	flow->deficit += fq->quantum;
71	list_move_tail(&flow->flowchain,
72	&tin->old_flows);
73	goto begin;
74	}
75
76	skb = dequeue_func(fq, tin, flow);
77	if (!skb) {
78	/* force a pass through old_flows to prevent starvation */
79	if ((head == &tin->new_flows) &&
80	!list_empty(&tin->old_flows)) {
81	list_move_tail(&flow->flowchain, &tin->old_flows);
82	} else {
83	list_del_init(&flow->flowchain);
84	flow->tin = NULL;
85	}
86	goto begin;
87	}
88
89	flow->deficit -= skb->len;
90	tin->tx_bytes += skb->len;
91	tin->tx_packets++;
92
93	return skb;
94	}
95
96	static struct fq_flow fq_flow_classify(struct fq fq,
97	struct fq_tin *tin,
98	struct sk_buff *skb,
99	fq_flow_get_default_t get_default_func)
100	{
101	struct fq_flow *flow;
102	u32 hash;
103	u32 idx;
104
105	lockdep_assert_held(&fq->lock);
106
107	hash = skb_get_hash_perturb(skb, fq->perturbation);
108	idx = reciprocal_scale(hash, fq->flows_cnt);
109	flow = &fq->flows[idx];
110
111	if (flow->tin && flow->tin != tin) {
112	flow = get_default_func(fq, tin, idx, skb);
113	tin->collisions++;
114	fq->collisions++;
115	}
116
117	if (!flow->tin)
118	tin->flows++;
119
120	return flow;
121	}
122
b43e7199 MK	123	static void fq_recalc_backlog(struct fq *fq,
	124	struct fq_tin *tin,
	125	struct fq_flow *flow)
	126	{
	127	struct fq_flow *i;
	128
	129	if (list_empty(&flow->backlogchain))
	130	list_add_tail(&flow->backlogchain, &fq->backlogs);
	131
	132	i = flow;
	133	list_for_each_entry_continue_reverse(i, &fq->backlogs,
	134	backlogchain)
	135	if (i->backlog > flow->backlog)
	136	break;
	137
	138	list_move(&flow->backlogchain, &i->backlogchain);
	139	}
	140
557fc4a0 MK	141	static void fq_tin_enqueue(struct fq *fq,
	142	struct fq_tin *tin,
	143	struct sk_buff *skb,
	144	fq_skb_free_t free_func,
	145	fq_flow_get_default_t get_default_func)
	146	{
	147	struct fq_flow *flow;
557fc4a0 MK	148
	149	lockdep_assert_held(&fq->lock);
	150
	151	flow = fq_flow_classify(fq, tin, skb, get_default_func);
	152
	153	flow->tin = tin;
	154	flow->backlog += skb->len;
	155	tin->backlog_bytes += skb->len;
	156	tin->backlog_packets++;
	157	fq->backlog++;
	158
b43e7199	159	fq_recalc_backlog(fq, tin, flow);
557fc4a0 MK	160
	161	if (list_empty(&flow->flowchain)) {
	162	flow->deficit = fq->quantum;
	163	list_add_tail(&flow->flowchain,
	164	&tin->new_flows);
	165	}
	166
	167	__skb_queue_tail(&flow->queue, skb);
	168
	169	if (fq->backlog > fq->limit) {
	170	flow = list_first_entry_or_null(&fq->backlogs,
	171	struct fq_flow,
	172	backlogchain);
	173	if (!flow)
	174	return;
	175
	176	skb = fq_flow_dequeue(fq, flow);
	177	if (!skb)
	178	return;
	179
	180	free_func(fq, flow->tin, flow, skb);
	181
	182	flow->tin->overlimit++;
	183	fq->overlimit++;
	184	}
	185	}
	186
	187	static void fq_flow_reset(struct fq *fq,
	188	struct fq_flow *flow,
	189	fq_skb_free_t free_func)
	190	{
	191	struct sk_buff *skb;
	192
	193	while ((skb = fq_flow_dequeue(fq, flow)))
	194	free_func(fq, flow->tin, flow, skb);
	195
	196	if (!list_empty(&flow->flowchain))
	197	list_del_init(&flow->flowchain);
	198
	199	if (!list_empty(&flow->backlogchain))
	200	list_del_init(&flow->backlogchain);
	201
	202	flow->tin = NULL;
	203
	204	WARN_ON_ONCE(flow->backlog);
	205	}
	206
	207	static void fq_tin_reset(struct fq *fq,
	208	struct fq_tin *tin,
	209	fq_skb_free_t free_func)
	210	{
	211	struct list_head *head;
	212	struct fq_flow *flow;
	213
	214	for (;;) {
	215	head = &tin->new_flows;
	216	if (list_empty(head)) {
	217	head = &tin->old_flows;
	218	if (list_empty(head))
	219	break;
	220	}
	221
	222	flow = list_first_entry(head, struct fq_flow, flowchain);
	223	fq_flow_reset(fq, flow, free_func);
224	}
225
226	WARN_ON_ONCE(tin->backlog_bytes);
227	WARN_ON_ONCE(tin->backlog_packets);
228	}
229
230	static void fq_flow_init(struct fq_flow *flow)
231	{
232	INIT_LIST_HEAD(&flow->flowchain);
233	INIT_LIST_HEAD(&flow->backlogchain);
234	__skb_queue_head_init(&flow->queue);
235	}
236
237	static void fq_tin_init(struct fq_tin *tin)
238	{
239	INIT_LIST_HEAD(&tin->new_flows);
240	INIT_LIST_HEAD(&tin->old_flows);
241	}
242
243	static int fq_init(struct fq *fq, int flows_cnt)
244	{
245	int i;
246
247	memset(fq, 0, sizeof(fq[0]));
248	INIT_LIST_HEAD(&fq->backlogs);
249	spin_lock_init(&fq->lock);
250	fq->flows_cnt = max_t(u32, flows_cnt, 1);
251	fq->perturbation = prandom_u32();
252	fq->quantum = 300;
253	fq->limit = 8192;
254
255	fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
256	if (!fq->flows)
257	return -ENOMEM;
258
259	for (i = 0; i < fq->flows_cnt; i++)
260	fq_flow_init(&fq->flows[i]);
261
262	return 0;
263	}
264
265	static void fq_reset(struct fq *fq,
266	fq_skb_free_t free_func)
267	{
268	int i;
269
270	for (i = 0; i < fq->flows_cnt; i++)
271	fq_flow_reset(fq, &fq->flows[i], free_func);
272
273	kfree(fq->flows);
274	fq->flows = NULL;
275	}
276
277	#endif