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/export.h> 15 #include <linux/string.h> 16 #include <linux/errno.h> 17 #include <linux/skbuff.h> 18 #include <net/netlink.h> 19 #include <net/pkt_sched.h> 20 21 struct mq_sched { 22 struct Qdisc **qdiscs; 23 }; 24 25 static void mq_destroy(struct Qdisc *sch) 26 { 27 struct net_device *dev = qdisc_dev(sch); 28 struct mq_sched *priv = qdisc_priv(sch); 29 unsigned int ntx; 30 31 if (!priv->qdiscs) 32 return; 33 for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++) 34 qdisc_destroy(priv->qdiscs[ntx]); 35 kfree(priv->qdiscs); 36 } 37 38 static int mq_init(struct Qdisc *sch, struct nlattr *opt) 39 { 40 struct net_device *dev = qdisc_dev(sch); 41 struct mq_sched *priv = qdisc_priv(sch); 42 struct netdev_queue *dev_queue; 43 struct Qdisc *qdisc; 44 unsigned int ntx; 45 46 if (sch->parent != TC_H_ROOT) 47 return -EOPNOTSUPP; 48 49 if (!netif_is_multiqueue(dev)) 50 return -EOPNOTSUPP; 51 52 /* pre-allocate qdiscs, attachment can't fail */ 53 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 54 GFP_KERNEL); 55 if (priv->qdiscs == NULL) 56 return -ENOMEM; 57 58 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 59 dev_queue = netdev_get_tx_queue(dev, ntx); 60 qdisc = qdisc_create_dflt(dev_queue, default_qdisc_ops, 61 TC_H_MAKE(TC_H_MAJ(sch->handle), 62 TC_H_MIN(ntx + 1))); 63 if (qdisc == NULL) 64 goto err; 65 priv->qdiscs[ntx] = qdisc; 66 qdisc->flags |= TCQ_F_ONETXQUEUE; 67 } 68 69 sch->flags |= TCQ_F_MQROOT; 70 return 0; 71 72 err: 73 mq_destroy(sch); 74 return -ENOMEM; 75 } 76 77 static void mq_attach(struct Qdisc *sch) 78 { 79 struct net_device *dev = qdisc_dev(sch); 80 struct mq_sched *priv = qdisc_priv(sch); 81 struct Qdisc *qdisc; 82 unsigned int ntx; 83 84 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 85 qdisc = priv->qdiscs[ntx]; 86 qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc); 87 if (qdisc) 88 qdisc_destroy(qdisc); 89 } 90 kfree(priv->qdiscs); 91 priv->qdiscs = NULL; 92 } 93 94 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) 95 { 96 struct net_device *dev = qdisc_dev(sch); 97 struct Qdisc *qdisc; 98 unsigned int ntx; 99 100 sch->q.qlen = 0; 101 memset(&sch->bstats, 0, sizeof(sch->bstats)); 102 memset(&sch->qstats, 0, sizeof(sch->qstats)); 103 104 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 105 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; 106 spin_lock_bh(qdisc_lock(qdisc)); 107 sch->q.qlen += qdisc->q.qlen; 108 sch->bstats.bytes += qdisc->bstats.bytes; 109 sch->bstats.packets += qdisc->bstats.packets; 110 sch->qstats.qlen += qdisc->qstats.qlen; 111 sch->qstats.backlog += qdisc->qstats.backlog; 112 sch->qstats.drops += qdisc->qstats.drops; 113 sch->qstats.requeues += qdisc->qstats.requeues; 114 sch->qstats.overlimits += qdisc->qstats.overlimits; 115 spin_unlock_bh(qdisc_lock(qdisc)); 116 } 117 return 0; 118 } 119 120 static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 121 { 122 struct net_device *dev = qdisc_dev(sch); 123 unsigned long ntx = cl - 1; 124 125 if (ntx >= dev->num_tx_queues) 126 return NULL; 127 return netdev_get_tx_queue(dev, ntx); 128 } 129 130 static struct netdev_queue *mq_select_queue(struct Qdisc *sch, 131 struct tcmsg *tcm) 132 { 133 unsigned int ntx = TC_H_MIN(tcm->tcm_parent); 134 struct netdev_queue *dev_queue = mq_queue_get(sch, ntx); 135 136 if (!dev_queue) { 137 struct net_device *dev = qdisc_dev(sch); 138 139 return netdev_get_tx_queue(dev, 0); 140 } 141 return dev_queue; 142 } 143 144 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 145 struct Qdisc **old) 146 { 147 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 148 struct net_device *dev = qdisc_dev(sch); 149 150 if (dev->flags & IFF_UP) 151 dev_deactivate(dev); 152 153 *old = dev_graft_qdisc(dev_queue, new); 154 if (new) 155 new->flags |= TCQ_F_ONETXQUEUE; 156 if (dev->flags & IFF_UP) 157 dev_activate(dev); 158 return 0; 159 } 160 161 static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) 162 { 163 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 164 165 return dev_queue->qdisc_sleeping; 166 } 167 168 static unsigned long mq_get(struct Qdisc *sch, u32 classid) 169 { 170 unsigned int ntx = TC_H_MIN(classid); 171 172 if (!mq_queue_get(sch, ntx)) 173 return 0; 174 return ntx; 175 } 176 177 static void mq_put(struct Qdisc *sch, unsigned long cl) 178 { 179 } 180 181 static int mq_dump_class(struct Qdisc *sch, unsigned long cl, 182 struct sk_buff *skb, struct tcmsg *tcm) 183 { 184 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 185 186 tcm->tcm_parent = TC_H_ROOT; 187 tcm->tcm_handle |= TC_H_MIN(cl); 188 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 189 return 0; 190 } 191 192 static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 193 struct gnet_dump *d) 194 { 195 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 196 197 sch = dev_queue->qdisc_sleeping; 198 sch->qstats.qlen = sch->q.qlen; 199 if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || 200 gnet_stats_copy_queue(d, &sch->qstats) < 0) 201 return -1; 202 return 0; 203 } 204 205 static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 206 { 207 struct net_device *dev = qdisc_dev(sch); 208 unsigned int ntx; 209 210 if (arg->stop) 211 return; 212 213 arg->count = arg->skip; 214 for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { 215 if (arg->fn(sch, ntx + 1, arg) < 0) { 216 arg->stop = 1; 217 break; 218 } 219 arg->count++; 220 } 221 } 222 223 static const struct Qdisc_class_ops mq_class_ops = { 224 .select_queue = mq_select_queue, 225 .graft = mq_graft, 226 .leaf = mq_leaf, 227 .get = mq_get, 228 .put = mq_put, 229 .walk = mq_walk, 230 .dump = mq_dump_class, 231 .dump_stats = mq_dump_class_stats, 232 }; 233 234 struct Qdisc_ops mq_qdisc_ops __read_mostly = { 235 .cl_ops = &mq_class_ops, 236 .id = "mq", 237 .priv_size = sizeof(struct mq_sched), 238 .init = mq_init, 239 .destroy = mq_destroy, 240 .attach = mq_attach, 241 .dump = mq_dump, 242 .owner = THIS_MODULE, 243 }; 244