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, get_default_qdisc_ops(dev, ntx), 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 | TCQ_F_NOPARENT; 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, *old; 82 unsigned int ntx; 83 84 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 85 qdisc = priv->qdiscs[ntx]; 86 old = dev_graft_qdisc(qdisc->dev_queue, qdisc); 87 if (old) 88 qdisc_destroy(old); 89 #ifdef CONFIG_NET_SCHED 90 if (ntx < dev->real_num_tx_queues) 91 qdisc_list_add(qdisc); 92 #endif 93 94 } 95 kfree(priv->qdiscs); 96 priv->qdiscs = NULL; 97 } 98 99 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) 100 { 101 struct net_device *dev = qdisc_dev(sch); 102 struct Qdisc *qdisc; 103 unsigned int ntx; 104 105 sch->q.qlen = 0; 106 memset(&sch->bstats, 0, sizeof(sch->bstats)); 107 memset(&sch->qstats, 0, sizeof(sch->qstats)); 108 109 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 110 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; 111 spin_lock_bh(qdisc_lock(qdisc)); 112 sch->q.qlen += qdisc->q.qlen; 113 sch->bstats.bytes += qdisc->bstats.bytes; 114 sch->bstats.packets += qdisc->bstats.packets; 115 sch->qstats.backlog += qdisc->qstats.backlog; 116 sch->qstats.drops += qdisc->qstats.drops; 117 sch->qstats.requeues += qdisc->qstats.requeues; 118 sch->qstats.overlimits += qdisc->qstats.overlimits; 119 spin_unlock_bh(qdisc_lock(qdisc)); 120 } 121 return 0; 122 } 123 124 static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 125 { 126 struct net_device *dev = qdisc_dev(sch); 127 unsigned long ntx = cl - 1; 128 129 if (ntx >= dev->num_tx_queues) 130 return NULL; 131 return netdev_get_tx_queue(dev, ntx); 132 } 133 134 static struct netdev_queue *mq_select_queue(struct Qdisc *sch, 135 struct tcmsg *tcm) 136 { 137 unsigned int ntx = TC_H_MIN(tcm->tcm_parent); 138 struct netdev_queue *dev_queue = mq_queue_get(sch, ntx); 139 140 if (!dev_queue) { 141 struct net_device *dev = qdisc_dev(sch); 142 143 return netdev_get_tx_queue(dev, 0); 144 } 145 return dev_queue; 146 } 147 148 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 149 struct Qdisc **old) 150 { 151 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 152 struct net_device *dev = qdisc_dev(sch); 153 154 if (dev->flags & IFF_UP) 155 dev_deactivate(dev); 156 157 *old = dev_graft_qdisc(dev_queue, new); 158 if (new) 159 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 160 if (dev->flags & IFF_UP) 161 dev_activate(dev); 162 return 0; 163 } 164 165 static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) 166 { 167 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 168 169 return dev_queue->qdisc_sleeping; 170 } 171 172 static unsigned long mq_get(struct Qdisc *sch, u32 classid) 173 { 174 unsigned int ntx = TC_H_MIN(classid); 175 176 if (!mq_queue_get(sch, ntx)) 177 return 0; 178 return ntx; 179 } 180 181 static void mq_put(struct Qdisc *sch, unsigned long cl) 182 { 183 } 184 185 static int mq_dump_class(struct Qdisc *sch, unsigned long cl, 186 struct sk_buff *skb, struct tcmsg *tcm) 187 { 188 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 189 190 tcm->tcm_parent = TC_H_ROOT; 191 tcm->tcm_handle |= TC_H_MIN(cl); 192 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 193 return 0; 194 } 195 196 static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 197 struct gnet_dump *d) 198 { 199 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 200 201 sch = dev_queue->qdisc_sleeping; 202 if (gnet_stats_copy_basic(d, NULL, &sch->bstats) < 0 || 203 gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0) 204 return -1; 205 return 0; 206 } 207 208 static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 209 { 210 struct net_device *dev = qdisc_dev(sch); 211 unsigned int ntx; 212 213 if (arg->stop) 214 return; 215 216 arg->count = arg->skip; 217 for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { 218 if (arg->fn(sch, ntx + 1, arg) < 0) { 219 arg->stop = 1; 220 break; 221 } 222 arg->count++; 223 } 224 } 225 226 static const struct Qdisc_class_ops mq_class_ops = { 227 .select_queue = mq_select_queue, 228 .graft = mq_graft, 229 .leaf = mq_leaf, 230 .get = mq_get, 231 .put = mq_put, 232 .walk = mq_walk, 233 .dump = mq_dump_class, 234 .dump_stats = mq_dump_class_stats, 235 }; 236 237 struct Qdisc_ops mq_qdisc_ops __read_mostly = { 238 .cl_ops = &mq_class_ops, 239 .id = "mq", 240 .priv_size = sizeof(struct mq_sched), 241 .init = mq_init, 242 .destroy = mq_destroy, 243 .attach = mq_attach, 244 .dump = mq_dump, 245 .owner = THIS_MODULE, 246 }; 247