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/slab.h> 13 #include <linux/kernel.h> 14 #include <linux/string.h> 15 #include <linux/errno.h> 16 #include <linux/skbuff.h> 17 #include <net/netlink.h> 18 #include <net/pkt_sched.h> 19 20 struct mq_sched { 21 struct Qdisc **qdiscs; 22 }; 23 24 static void mq_destroy(struct Qdisc *sch) 25 { 26 struct net_device *dev = qdisc_dev(sch); 27 struct mq_sched *priv = qdisc_priv(sch); 28 unsigned int ntx; 29 30 if (!priv->qdiscs) 31 return; 32 for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++) 33 qdisc_destroy(priv->qdiscs[ntx]); 34 kfree(priv->qdiscs); 35 } 36 37 static int mq_init(struct Qdisc *sch, struct nlattr *opt) 38 { 39 struct net_device *dev = qdisc_dev(sch); 40 struct mq_sched *priv = qdisc_priv(sch); 41 struct netdev_queue *dev_queue; 42 struct Qdisc *qdisc; 43 unsigned int ntx; 44 45 if (sch->parent != TC_H_ROOT) 46 return -EOPNOTSUPP; 47 48 if (!netif_is_multiqueue(dev)) 49 return -EOPNOTSUPP; 50 51 /* pre-allocate qdiscs, attachment can't fail */ 52 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 53 GFP_KERNEL); 54 if (priv->qdiscs == NULL) 55 return -ENOMEM; 56 57 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 58 dev_queue = netdev_get_tx_queue(dev, ntx); 59 qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops, 60 TC_H_MAKE(TC_H_MAJ(sch->handle), 61 TC_H_MIN(ntx + 1))); 62 if (qdisc == NULL) 63 goto err; 64 priv->qdiscs[ntx] = qdisc; 65 } 66 67 sch->flags |= TCQ_F_MQROOT; 68 return 0; 69 70 err: 71 mq_destroy(sch); 72 return -ENOMEM; 73 } 74 75 static void mq_attach(struct Qdisc *sch) 76 { 77 struct net_device *dev = qdisc_dev(sch); 78 struct mq_sched *priv = qdisc_priv(sch); 79 struct Qdisc *qdisc; 80 unsigned int ntx; 81 82 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 83 qdisc = priv->qdiscs[ntx]; 84 qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc); 85 if (qdisc) 86 qdisc_destroy(qdisc); 87 } 88 kfree(priv->qdiscs); 89 priv->qdiscs = NULL; 90 } 91 92 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) 93 { 94 struct net_device *dev = qdisc_dev(sch); 95 struct Qdisc *qdisc; 96 unsigned int ntx; 97 98 sch->q.qlen = 0; 99 memset(&sch->bstats, 0, sizeof(sch->bstats)); 100 memset(&sch->qstats, 0, sizeof(sch->qstats)); 101 102 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 103 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; 104 spin_lock_bh(qdisc_lock(qdisc)); 105 sch->q.qlen += qdisc->q.qlen; 106 sch->bstats.bytes += qdisc->bstats.bytes; 107 sch->bstats.packets += qdisc->bstats.packets; 108 sch->qstats.qlen += qdisc->qstats.qlen; 109 sch->qstats.backlog += qdisc->qstats.backlog; 110 sch->qstats.drops += qdisc->qstats.drops; 111 sch->qstats.requeues += qdisc->qstats.requeues; 112 sch->qstats.overlimits += qdisc->qstats.overlimits; 113 spin_unlock_bh(qdisc_lock(qdisc)); 114 } 115 return 0; 116 } 117 118 static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 119 { 120 struct net_device *dev = qdisc_dev(sch); 121 unsigned long ntx = cl - 1; 122 123 if (ntx >= dev->num_tx_queues) 124 return NULL; 125 return netdev_get_tx_queue(dev, ntx); 126 } 127 128 static struct netdev_queue *mq_select_queue(struct Qdisc *sch, 129 struct tcmsg *tcm) 130 { 131 unsigned int ntx = TC_H_MIN(tcm->tcm_parent); 132 struct netdev_queue *dev_queue = mq_queue_get(sch, ntx); 133 134 if (!dev_queue) { 135 struct net_device *dev = qdisc_dev(sch); 136 137 return netdev_get_tx_queue(dev, 0); 138 } 139 return dev_queue; 140 } 141 142 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 143 struct Qdisc **old) 144 { 145 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 146 struct net_device *dev = qdisc_dev(sch); 147 148 if (dev->flags & IFF_UP) 149 dev_deactivate(dev); 150 151 *old = dev_graft_qdisc(dev_queue, new); 152 153 if (dev->flags & IFF_UP) 154 dev_activate(dev); 155 return 0; 156 } 157 158 static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) 159 { 160 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 161 162 return dev_queue->qdisc_sleeping; 163 } 164 165 static unsigned long mq_get(struct Qdisc *sch, u32 classid) 166 { 167 unsigned int ntx = TC_H_MIN(classid); 168 169 if (!mq_queue_get(sch, ntx)) 170 return 0; 171 return ntx; 172 } 173 174 static void mq_put(struct Qdisc *sch, unsigned long cl) 175 { 176 } 177 178 static int mq_dump_class(struct Qdisc *sch, unsigned long cl, 179 struct sk_buff *skb, struct tcmsg *tcm) 180 { 181 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 182 183 tcm->tcm_parent = TC_H_ROOT; 184 tcm->tcm_handle |= TC_H_MIN(cl); 185 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 186 return 0; 187 } 188 189 static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 190 struct gnet_dump *d) 191 { 192 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 193 194 sch = dev_queue->qdisc_sleeping; 195 sch->qstats.qlen = sch->q.qlen; 196 if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || 197 gnet_stats_copy_queue(d, &sch->qstats) < 0) 198 return -1; 199 return 0; 200 } 201 202 static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 203 { 204 struct net_device *dev = qdisc_dev(sch); 205 unsigned int ntx; 206 207 if (arg->stop) 208 return; 209 210 arg->count = arg->skip; 211 for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { 212 if (arg->fn(sch, ntx + 1, arg) < 0) { 213 arg->stop = 1; 214 break; 215 } 216 arg->count++; 217 } 218 } 219 220 static const struct Qdisc_class_ops mq_class_ops = { 221 .select_queue = mq_select_queue, 222 .graft = mq_graft, 223 .leaf = mq_leaf, 224 .get = mq_get, 225 .put = mq_put, 226 .walk = mq_walk, 227 .dump = mq_dump_class, 228 .dump_stats = mq_dump_class_stats, 229 }; 230 231 struct Qdisc_ops mq_qdisc_ops __read_mostly = { 232 .cl_ops = &mq_class_ops, 233 .id = "mq", 234 .priv_size = sizeof(struct mq_sched), 235 .init = mq_init, 236 .destroy = mq_destroy, 237 .attach = mq_attach, 238 .dump = mq_dump, 239 .owner = THIS_MODULE, 240 }; 241