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6ec1c69a DM |
1 | /* |
2 | * net/sched/sch_mq.c Classful multiqueue dummy scheduler | |
3 | * | |
4 | * Copyright (c) 2009 Patrick McHardy <kaber@trash.net> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * version 2 as published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/types.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/string.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/skbuff.h> | |
16 | #include <net/netlink.h> | |
17 | #include <net/pkt_sched.h> | |
18 | ||
19 | struct mq_sched { | |
20 | struct Qdisc **qdiscs; | |
21 | }; | |
22 | ||
23 | static void mq_destroy(struct Qdisc *sch) | |
24 | { | |
25 | struct net_device *dev = qdisc_dev(sch); | |
26 | struct mq_sched *priv = qdisc_priv(sch); | |
27 | unsigned int ntx; | |
28 | ||
29 | if (!priv->qdiscs) | |
30 | return; | |
31 | for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++) | |
32 | qdisc_destroy(priv->qdiscs[ntx]); | |
33 | kfree(priv->qdiscs); | |
34 | } | |
35 | ||
36 | static int mq_init(struct Qdisc *sch, struct nlattr *opt) | |
37 | { | |
38 | struct net_device *dev = qdisc_dev(sch); | |
39 | struct mq_sched *priv = qdisc_priv(sch); | |
40 | struct netdev_queue *dev_queue; | |
41 | struct Qdisc *qdisc; | |
42 | unsigned int ntx; | |
43 | ||
44 | if (sch->parent != TC_H_ROOT) | |
45 | return -EOPNOTSUPP; | |
46 | ||
47 | if (!netif_is_multiqueue(dev)) | |
48 | return -EOPNOTSUPP; | |
49 | ||
50 | /* pre-allocate qdiscs, attachment can't fail */ | |
51 | priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), | |
52 | GFP_KERNEL); | |
53 | if (priv->qdiscs == NULL) | |
54 | return -ENOMEM; | |
55 | ||
56 | for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { | |
57 | dev_queue = netdev_get_tx_queue(dev, ntx); | |
58 | qdisc = qdisc_create_dflt(dev, dev_queue, &pfifo_fast_ops, | |
59 | TC_H_MAKE(TC_H_MAJ(sch->handle), | |
60 | TC_H_MIN(ntx + 1))); | |
61 | if (qdisc == NULL) | |
62 | goto err; | |
63 | qdisc->flags |= TCQ_F_CAN_BYPASS; | |
64 | priv->qdiscs[ntx] = qdisc; | |
65 | } | |
66 | ||
67 | return 0; | |
68 | ||
69 | err: | |
70 | mq_destroy(sch); | |
71 | return -ENOMEM; | |
72 | } | |
73 | ||
74 | static void mq_attach(struct Qdisc *sch) | |
75 | { | |
76 | struct net_device *dev = qdisc_dev(sch); | |
77 | struct mq_sched *priv = qdisc_priv(sch); | |
78 | struct Qdisc *qdisc; | |
79 | unsigned int ntx; | |
80 | ||
81 | for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { | |
82 | qdisc = priv->qdiscs[ntx]; | |
83 | qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc); | |
84 | if (qdisc) | |
85 | qdisc_destroy(qdisc); | |
86 | } | |
87 | kfree(priv->qdiscs); | |
88 | priv->qdiscs = NULL; | |
89 | } | |
90 | ||
91 | static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) | |
92 | { | |
93 | struct net_device *dev = qdisc_dev(sch); | |
94 | struct Qdisc *qdisc; | |
95 | unsigned int ntx; | |
96 | ||
97 | sch->q.qlen = 0; | |
98 | memset(&sch->bstats, 0, sizeof(sch->bstats)); | |
99 | memset(&sch->qstats, 0, sizeof(sch->qstats)); | |
100 | ||
101 | for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { | |
102 | qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; | |
103 | spin_lock_bh(qdisc_lock(qdisc)); | |
104 | sch->q.qlen += qdisc->q.qlen; | |
105 | sch->bstats.bytes += qdisc->bstats.bytes; | |
106 | sch->bstats.packets += qdisc->bstats.packets; | |
107 | sch->qstats.qlen += qdisc->qstats.qlen; | |
108 | sch->qstats.backlog += qdisc->qstats.backlog; | |
109 | sch->qstats.drops += qdisc->qstats.drops; | |
110 | sch->qstats.requeues += qdisc->qstats.requeues; | |
111 | sch->qstats.overlimits += qdisc->qstats.overlimits; | |
112 | spin_unlock_bh(qdisc_lock(qdisc)); | |
113 | } | |
114 | return 0; | |
115 | } | |
116 | ||
117 | static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) | |
118 | { | |
119 | struct net_device *dev = qdisc_dev(sch); | |
120 | unsigned long ntx = cl - 1; | |
121 | ||
122 | if (ntx >= dev->num_tx_queues) | |
123 | return NULL; | |
124 | return netdev_get_tx_queue(dev, ntx); | |
125 | } | |
126 | ||
127 | static unsigned int mq_select_queue(struct Qdisc *sch, struct tcmsg *tcm) | |
128 | { | |
129 | unsigned int ntx = TC_H_MIN(tcm->tcm_parent); | |
130 | ||
131 | if (!mq_queue_get(sch, ntx)) | |
132 | return 0; | |
133 | return ntx - 1; | |
134 | } | |
135 | ||
136 | static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, | |
137 | struct Qdisc **old) | |
138 | { | |
139 | struct netdev_queue *dev_queue = mq_queue_get(sch, cl); | |
140 | struct net_device *dev = qdisc_dev(sch); | |
141 | ||
142 | if (dev->flags & IFF_UP) | |
143 | dev_deactivate(dev); | |
144 | ||
145 | *old = dev_graft_qdisc(dev_queue, new); | |
146 | ||
147 | if (dev->flags & IFF_UP) | |
148 | dev_activate(dev); | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) | |
153 | { | |
154 | struct netdev_queue *dev_queue = mq_queue_get(sch, cl); | |
155 | ||
156 | return dev_queue->qdisc_sleeping; | |
157 | } | |
158 | ||
159 | static unsigned long mq_get(struct Qdisc *sch, u32 classid) | |
160 | { | |
161 | unsigned int ntx = TC_H_MIN(classid); | |
162 | ||
163 | if (!mq_queue_get(sch, ntx)) | |
164 | return 0; | |
165 | return ntx; | |
166 | } | |
167 | ||
168 | static void mq_put(struct Qdisc *sch, unsigned long cl) | |
169 | { | |
170 | return; | |
171 | } | |
172 | ||
173 | static int mq_dump_class(struct Qdisc *sch, unsigned long cl, | |
174 | struct sk_buff *skb, struct tcmsg *tcm) | |
175 | { | |
176 | struct netdev_queue *dev_queue = mq_queue_get(sch, cl); | |
177 | ||
178 | tcm->tcm_parent = TC_H_ROOT; | |
179 | tcm->tcm_handle |= TC_H_MIN(cl); | |
180 | tcm->tcm_info = dev_queue->qdisc_sleeping->handle; | |
181 | return 0; | |
182 | } | |
183 | ||
184 | static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, | |
185 | struct gnet_dump *d) | |
186 | { | |
187 | struct netdev_queue *dev_queue = mq_queue_get(sch, cl); | |
188 | ||
189 | sch = dev_queue->qdisc_sleeping; | |
190 | if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || | |
191 | gnet_stats_copy_queue(d, &sch->qstats) < 0) | |
192 | return -1; | |
193 | return 0; | |
194 | } | |
195 | ||
196 | static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
197 | { | |
198 | struct net_device *dev = qdisc_dev(sch); | |
199 | unsigned int ntx; | |
200 | ||
201 | if (arg->stop) | |
202 | return; | |
203 | ||
204 | arg->count = arg->skip; | |
205 | for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { | |
206 | if (arg->fn(sch, ntx + 1, arg) < 0) { | |
207 | arg->stop = 1; | |
208 | break; | |
209 | } | |
210 | arg->count++; | |
211 | } | |
212 | } | |
213 | ||
214 | static const struct Qdisc_class_ops mq_class_ops = { | |
215 | .select_queue = mq_select_queue, | |
216 | .graft = mq_graft, | |
217 | .leaf = mq_leaf, | |
218 | .get = mq_get, | |
219 | .put = mq_put, | |
220 | .walk = mq_walk, | |
221 | .dump = mq_dump_class, | |
222 | .dump_stats = mq_dump_class_stats, | |
223 | }; | |
224 | ||
225 | struct Qdisc_ops mq_qdisc_ops __read_mostly = { | |
226 | .cl_ops = &mq_class_ops, | |
227 | .id = "mq", | |
228 | .priv_size = sizeof(struct mq_sched), | |
229 | .init = mq_init, | |
230 | .destroy = mq_destroy, | |
231 | .attach = mq_attach, | |
232 | .dump = mq_dump, | |
233 | .owner = THIS_MODULE, | |
234 | }; |