aboutsummaryrefslogtreecommitdiff
path: root/net/sched/sch_mq.c
blob: 3a3312467692c4f17bc03a78299322ac9a67250c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
/*
 * net/sched/sch_mq.c		Classful multiqueue dummy scheduler
 *
 * Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/pkt_cls.h>
#include <net/pkt_sched.h>
#include <net/sch_generic.h>

struct mq_sched {
	struct Qdisc		**qdiscs;
};

static int mq_offload(struct Qdisc *sch, enum tc_mq_command cmd)
{
	struct net_device *dev = qdisc_dev(sch);
	struct tc_mq_qopt_offload opt = {
		.command = cmd,
		.handle = sch->handle,
	};

	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
		return -EOPNOTSUPP;

	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_MQ, &opt);
}

static int mq_offload_stats(struct Qdisc *sch)
{
	struct tc_mq_qopt_offload opt = {
		.command = TC_MQ_STATS,
		.handle = sch->handle,
		.stats = {
			.bstats = &sch->bstats,
			.qstats = &sch->qstats,
		},
	};

	return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_MQ, &opt);
}

static void mq_destroy(struct Qdisc *sch)
{
	struct net_device *dev = qdisc_dev(sch);
	struct mq_sched *priv = qdisc_priv(sch);
	unsigned int ntx;

	mq_offload(sch, TC_MQ_DESTROY);

	if (!priv->qdiscs)
		return;
	for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
		qdisc_put(priv->qdiscs[ntx]);
	kfree(priv->qdiscs);
}

static int mq_init(struct Qdisc *sch, struct nlattr *opt,
		   struct netlink_ext_ack *extack)
{
	struct net_device *dev = qdisc_dev(sch);
	struct mq_sched *priv = qdisc_priv(sch);
	struct netdev_queue *dev_queue;
	struct Qdisc *qdisc;
	unsigned int ntx;

	if (sch->parent != TC_H_ROOT)
		return -EOPNOTSUPP;

	if (!netif_is_multiqueue(dev))
		return -EOPNOTSUPP;

	/* pre-allocate qdiscs, attachment can't fail */
	priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
			       GFP_KERNEL);
	if (!priv->qdiscs)
		return -ENOMEM;

	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
		dev_queue = netdev_get_tx_queue(dev, ntx);
		qdisc = qdisc_create_dflt(dev_queue, get_default_qdisc_ops(dev, ntx),
					  TC_H_MAKE(TC_H_MAJ(sch->handle),
						    TC_H_MIN(ntx + 1)),
					  extack);
		if (!qdisc)
			return -ENOMEM;
		priv->qdiscs[ntx] = qdisc;
		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
	}

	sch->flags |= TCQ_F_MQROOT;

	mq_offload(sch, TC_MQ_CREATE);
	return 0;
}

static void mq_attach(struct Qdisc *sch)
{
	struct net_device *dev = qdisc_dev(sch);
	struct mq_sched *priv = qdisc_priv(sch);
	struct Qdisc *qdisc, *old;
	unsigned int ntx;

	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
		qdisc = priv->qdiscs[ntx];
		old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
		if (old)
			qdisc_put(old);
#ifdef CONFIG_NET_SCHED
		if (ntx < dev->real_num_tx_queues)
			qdisc_hash_add(qdisc, false);
#endif

	}
	kfree(priv->qdiscs);
	priv->qdiscs = NULL;
}

static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct net_device *dev = qdisc_dev(sch);
	struct Qdisc *qdisc;
	unsigned int ntx;
	__u32 qlen = 0;

	sch->q.qlen = 0;
	memset(&sch->bstats, 0, sizeof(sch->bstats));
	memset(&sch->qstats, 0, sizeof(sch->qstats));

	/* MQ supports lockless qdiscs. However, statistics accounting needs
	 * to account for all, none, or a mix of locked and unlocked child
	 * qdiscs. Percpu stats are added to counters in-band and locking
	 * qdisc totals are added at end.
	 */
	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
		qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
		spin_lock_bh(qdisc_lock(qdisc));

		if (qdisc_is_percpu_stats(qdisc)) {
			qlen = qdisc_qlen_sum(qdisc);
			__gnet_stats_copy_basic(NULL, &sch->bstats,
						qdisc->cpu_bstats,
						&qdisc->bstats);
			__gnet_stats_copy_queue(&sch->qstats,
						qdisc->cpu_qstats,
						&qdisc->qstats, qlen);
		} else {
			sch->q.qlen		+= qdisc->q.qlen;
			sch->bstats.bytes	+= qdisc->bstats.bytes;
			sch->bstats.packets	+= qdisc->bstats.packets;
			sch->qstats.qlen	+= qdisc->qstats.qlen;
			sch->qstats.backlog	+= qdisc->qstats.backlog;
			sch->qstats.drops	+= qdisc->qstats.drops;
			sch->qstats.requeues	+= qdisc->qstats.requeues;
			sch->qstats.overlimits	+= qdisc->qstats.overlimits;
		}

		spin_unlock_bh(qdisc_lock(qdisc));
	}

	return mq_offload_stats(sch);
}

static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl)
{
	struct net_device *dev = qdisc_dev(sch);
	unsigned long ntx = cl - 1;

	if (ntx >= dev->num_tx_queues)
		return NULL;
	return netdev_get_tx_queue(dev, ntx);
}

static struct netdev_queue *mq_select_queue(struct Qdisc *sch,
					    struct tcmsg *tcm)
{
	return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
}

static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
		    struct Qdisc **old, struct netlink_ext_ack *extack)
{
	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
	struct tc_mq_qopt_offload graft_offload;
	struct net_device *dev = qdisc_dev(sch);

	if (dev->flags & IFF_UP)
		dev_deactivate(dev);

	*old = dev_graft_qdisc(dev_queue, new);
	if (new)
		new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
	if (dev->flags & IFF_UP)
		dev_activate(dev);

	graft_offload.handle = sch->handle;
	graft_offload.graft_params.queue = cl - 1;
	graft_offload.graft_params.child_handle = new ? new->handle : 0;
	graft_offload.command = TC_MQ_GRAFT;

	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old,
				   TC_SETUP_QDISC_MQ, &graft_offload, extack);
	return 0;
}

static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
{
	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);

	return dev_queue->qdisc_sleeping;
}

static unsigned long mq_find(struct Qdisc *sch, u32 classid)
{
	unsigned int ntx = TC_H_MIN(classid);

	if (!mq_queue_get(sch, ntx))
		return 0;
	return ntx;
}

static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
			 struct sk_buff *skb, struct tcmsg *tcm)
{
	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);

	tcm->tcm_parent = TC_H_ROOT;
	tcm->tcm_handle |= TC_H_MIN(cl);
	tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
	return 0;
}

static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
			       struct gnet_dump *d)
{
	struct netdev_queue *dev_queue = mq_queue_get(sch, cl);

	sch = dev_queue->qdisc_sleeping;
	if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
	    qdisc_qstats_copy(d, sch) < 0)
		return -1;
	return 0;
}

static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct net_device *dev = qdisc_dev(sch);
	unsigned int ntx;

	if (arg->stop)
		return;

	arg->count = arg->skip;
	for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
		if (arg->fn(sch, ntx + 1, arg) < 0) {
			arg->stop = 1;
			break;
		}
		arg->count++;
	}
}

static const struct Qdisc_class_ops mq_class_ops = {
	.select_queue	= mq_select_queue,
	.graft		= mq_graft,
	.leaf		= mq_leaf,
	.find		= mq_find,
	.walk		= mq_walk,
	.dump		= mq_dump_class,
	.dump_stats	= mq_dump_class_stats,
};

struct Qdisc_ops mq_qdisc_ops __read_mostly = {
	.cl_ops		= &mq_class_ops,
	.id		= "mq",
	.priv_size	= sizeof(struct mq_sched),
	.init		= mq_init,
	.destroy	= mq_destroy,
	.attach		= mq_attach,
	.dump		= mq_dump,
	.owner		= THIS_MODULE,
};