1 /* 2 * net/sched/sch_mqprio.c 3 * 4 * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com> 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 <linux/module.h> 18 #include <net/netlink.h> 19 #include <net/pkt_sched.h> 20 #include <net/sch_generic.h> 21 22 struct mqprio_sched { 23 struct Qdisc **qdiscs; 24 int hw_owned; 25 }; 26 27 static void mqprio_destroy(struct Qdisc *sch) 28 { 29 struct net_device *dev = qdisc_dev(sch); 30 struct mqprio_sched *priv = qdisc_priv(sch); 31 unsigned int ntx; 32 33 if (priv->qdiscs) { 34 for (ntx = 0; 35 ntx < dev->num_tx_queues && priv->qdiscs[ntx]; 36 ntx++) 37 qdisc_destroy(priv->qdiscs[ntx]); 38 kfree(priv->qdiscs); 39 } 40 41 if (priv->hw_owned && dev->netdev_ops->ndo_setup_tc) 42 dev->netdev_ops->ndo_setup_tc(dev, 0); 43 else 44 netdev_set_num_tc(dev, 0); 45 } 46 47 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt) 48 { 49 int i, j; 50 51 /* Verify num_tc is not out of max range */ 52 if (qopt->num_tc > TC_MAX_QUEUE) 53 return -EINVAL; 54 55 /* Verify priority mapping uses valid tcs */ 56 for (i = 0; i < TC_BITMASK + 1; i++) { 57 if (qopt->prio_tc_map[i] >= qopt->num_tc) 58 return -EINVAL; 59 } 60 61 /* net_device does not support requested operation */ 62 if (qopt->hw && !dev->netdev_ops->ndo_setup_tc) 63 return -EINVAL; 64 65 /* if hw owned qcount and qoffset are taken from LLD so 66 * no reason to verify them here 67 */ 68 if (qopt->hw) 69 return 0; 70 71 for (i = 0; i < qopt->num_tc; i++) { 72 unsigned int last = qopt->offset[i] + qopt->count[i]; 73 74 /* Verify the queue count is in tx range being equal to the 75 * real_num_tx_queues indicates the last queue is in use. 76 */ 77 if (qopt->offset[i] >= dev->real_num_tx_queues || 78 !qopt->count[i] || 79 last > dev->real_num_tx_queues) 80 return -EINVAL; 81 82 /* Verify that the offset and counts do not overlap */ 83 for (j = i + 1; j < qopt->num_tc; j++) { 84 if (last > qopt->offset[j]) 85 return -EINVAL; 86 } 87 } 88 89 return 0; 90 } 91 92 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt) 93 { 94 struct net_device *dev = qdisc_dev(sch); 95 struct mqprio_sched *priv = qdisc_priv(sch); 96 struct netdev_queue *dev_queue; 97 struct Qdisc *qdisc; 98 int i, err = -EOPNOTSUPP; 99 struct tc_mqprio_qopt *qopt = NULL; 100 101 BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE); 102 BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK); 103 104 if (sch->parent != TC_H_ROOT) 105 return -EOPNOTSUPP; 106 107 if (!netif_is_multiqueue(dev)) 108 return -EOPNOTSUPP; 109 110 if (!opt || nla_len(opt) < sizeof(*qopt)) 111 return -EINVAL; 112 113 qopt = nla_data(opt); 114 if (mqprio_parse_opt(dev, qopt)) 115 return -EINVAL; 116 117 /* pre-allocate qdisc, attachment can't fail */ 118 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 119 GFP_KERNEL); 120 if (priv->qdiscs == NULL) { 121 err = -ENOMEM; 122 goto err; 123 } 124 125 for (i = 0; i < dev->num_tx_queues; i++) { 126 dev_queue = netdev_get_tx_queue(dev, i); 127 qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops, 128 TC_H_MAKE(TC_H_MAJ(sch->handle), 129 TC_H_MIN(i + 1))); 130 if (qdisc == NULL) { 131 err = -ENOMEM; 132 goto err; 133 } 134 priv->qdiscs[i] = qdisc; 135 } 136 137 /* If the mqprio options indicate that hardware should own 138 * the queue mapping then run ndo_setup_tc otherwise use the 139 * supplied and verified mapping 140 */ 141 if (qopt->hw) { 142 priv->hw_owned = 1; 143 err = dev->netdev_ops->ndo_setup_tc(dev, qopt->num_tc); 144 if (err) 145 goto err; 146 } else { 147 netdev_set_num_tc(dev, qopt->num_tc); 148 for (i = 0; i < qopt->num_tc; i++) 149 netdev_set_tc_queue(dev, i, 150 qopt->count[i], qopt->offset[i]); 151 } 152 153 /* Always use supplied priority mappings */ 154 for (i = 0; i < TC_BITMASK + 1; i++) 155 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]); 156 157 sch->flags |= TCQ_F_MQROOT; 158 return 0; 159 160 err: 161 mqprio_destroy(sch); 162 return err; 163 } 164 165 static void mqprio_attach(struct Qdisc *sch) 166 { 167 struct net_device *dev = qdisc_dev(sch); 168 struct mqprio_sched *priv = qdisc_priv(sch); 169 struct Qdisc *qdisc; 170 unsigned int ntx; 171 172 /* Attach underlying qdisc */ 173 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 174 qdisc = priv->qdiscs[ntx]; 175 qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc); 176 if (qdisc) 177 qdisc_destroy(qdisc); 178 } 179 kfree(priv->qdiscs); 180 priv->qdiscs = NULL; 181 } 182 183 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch, 184 unsigned long cl) 185 { 186 struct net_device *dev = qdisc_dev(sch); 187 unsigned long ntx = cl - 1 - netdev_get_num_tc(dev); 188 189 if (ntx >= dev->num_tx_queues) 190 return NULL; 191 return netdev_get_tx_queue(dev, ntx); 192 } 193 194 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 195 struct Qdisc **old) 196 { 197 struct net_device *dev = qdisc_dev(sch); 198 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 199 200 if (!dev_queue) 201 return -EINVAL; 202 203 if (dev->flags & IFF_UP) 204 dev_deactivate(dev); 205 206 *old = dev_graft_qdisc(dev_queue, new); 207 208 if (dev->flags & IFF_UP) 209 dev_activate(dev); 210 211 return 0; 212 } 213 214 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) 215 { 216 struct net_device *dev = qdisc_dev(sch); 217 struct mqprio_sched *priv = qdisc_priv(sch); 218 unsigned char *b = skb_tail_pointer(skb); 219 struct tc_mqprio_qopt opt = { 0 }; 220 struct Qdisc *qdisc; 221 unsigned int i; 222 223 sch->q.qlen = 0; 224 memset(&sch->bstats, 0, sizeof(sch->bstats)); 225 memset(&sch->qstats, 0, sizeof(sch->qstats)); 226 227 for (i = 0; i < dev->num_tx_queues; i++) { 228 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 229 spin_lock_bh(qdisc_lock(qdisc)); 230 sch->q.qlen += qdisc->q.qlen; 231 sch->bstats.bytes += qdisc->bstats.bytes; 232 sch->bstats.packets += qdisc->bstats.packets; 233 sch->qstats.qlen += qdisc->qstats.qlen; 234 sch->qstats.backlog += qdisc->qstats.backlog; 235 sch->qstats.drops += qdisc->qstats.drops; 236 sch->qstats.requeues += qdisc->qstats.requeues; 237 sch->qstats.overlimits += qdisc->qstats.overlimits; 238 spin_unlock_bh(qdisc_lock(qdisc)); 239 } 240 241 opt.num_tc = netdev_get_num_tc(dev); 242 memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map)); 243 opt.hw = priv->hw_owned; 244 245 for (i = 0; i < netdev_get_num_tc(dev); i++) { 246 opt.count[i] = dev->tc_to_txq[i].count; 247 opt.offset[i] = dev->tc_to_txq[i].offset; 248 } 249 250 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 251 goto nla_put_failure; 252 253 return skb->len; 254 nla_put_failure: 255 nlmsg_trim(skb, b); 256 return -1; 257 } 258 259 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl) 260 { 261 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 262 263 if (!dev_queue) 264 return NULL; 265 266 return dev_queue->qdisc_sleeping; 267 } 268 269 static unsigned long mqprio_get(struct Qdisc *sch, u32 classid) 270 { 271 struct net_device *dev = qdisc_dev(sch); 272 unsigned int ntx = TC_H_MIN(classid); 273 274 if (ntx > dev->num_tx_queues + netdev_get_num_tc(dev)) 275 return 0; 276 return ntx; 277 } 278 279 static void mqprio_put(struct Qdisc *sch, unsigned long cl) 280 { 281 } 282 283 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl, 284 struct sk_buff *skb, struct tcmsg *tcm) 285 { 286 struct net_device *dev = qdisc_dev(sch); 287 288 if (cl <= netdev_get_num_tc(dev)) { 289 tcm->tcm_parent = TC_H_ROOT; 290 tcm->tcm_info = 0; 291 } else { 292 int i; 293 struct netdev_queue *dev_queue; 294 295 dev_queue = mqprio_queue_get(sch, cl); 296 tcm->tcm_parent = 0; 297 for (i = 0; i < netdev_get_num_tc(dev); i++) { 298 struct netdev_tc_txq tc = dev->tc_to_txq[i]; 299 int q_idx = cl - netdev_get_num_tc(dev); 300 301 if (q_idx > tc.offset && 302 q_idx <= tc.offset + tc.count) { 303 tcm->tcm_parent = 304 TC_H_MAKE(TC_H_MAJ(sch->handle), 305 TC_H_MIN(i + 1)); 306 break; 307 } 308 } 309 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 310 } 311 tcm->tcm_handle |= TC_H_MIN(cl); 312 return 0; 313 } 314 315 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 316 struct gnet_dump *d) 317 __releases(d->lock) 318 __acquires(d->lock) 319 { 320 struct net_device *dev = qdisc_dev(sch); 321 322 if (cl <= netdev_get_num_tc(dev)) { 323 int i; 324 struct Qdisc *qdisc; 325 struct gnet_stats_queue qstats = {0}; 326 struct gnet_stats_basic_packed bstats = {0}; 327 struct netdev_tc_txq tc = dev->tc_to_txq[cl - 1]; 328 329 /* Drop lock here it will be reclaimed before touching 330 * statistics this is required because the d->lock we 331 * hold here is the look on dev_queue->qdisc_sleeping 332 * also acquired below. 333 */ 334 spin_unlock_bh(d->lock); 335 336 for (i = tc.offset; i < tc.offset + tc.count; i++) { 337 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 338 spin_lock_bh(qdisc_lock(qdisc)); 339 bstats.bytes += qdisc->bstats.bytes; 340 bstats.packets += qdisc->bstats.packets; 341 qstats.qlen += qdisc->qstats.qlen; 342 qstats.backlog += qdisc->qstats.backlog; 343 qstats.drops += qdisc->qstats.drops; 344 qstats.requeues += qdisc->qstats.requeues; 345 qstats.overlimits += qdisc->qstats.overlimits; 346 spin_unlock_bh(qdisc_lock(qdisc)); 347 } 348 /* Reclaim root sleeping lock before completing stats */ 349 spin_lock_bh(d->lock); 350 if (gnet_stats_copy_basic(d, &bstats) < 0 || 351 gnet_stats_copy_queue(d, &qstats) < 0) 352 return -1; 353 } else { 354 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 355 356 sch = dev_queue->qdisc_sleeping; 357 sch->qstats.qlen = sch->q.qlen; 358 if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || 359 gnet_stats_copy_queue(d, &sch->qstats) < 0) 360 return -1; 361 } 362 return 0; 363 } 364 365 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 366 { 367 struct net_device *dev = qdisc_dev(sch); 368 unsigned long ntx; 369 370 if (arg->stop) 371 return; 372 373 /* Walk hierarchy with a virtual class per tc */ 374 arg->count = arg->skip; 375 for (ntx = arg->skip; 376 ntx < dev->num_tx_queues + netdev_get_num_tc(dev); 377 ntx++) { 378 if (arg->fn(sch, ntx + 1, arg) < 0) { 379 arg->stop = 1; 380 break; 381 } 382 arg->count++; 383 } 384 } 385 386 static const struct Qdisc_class_ops mqprio_class_ops = { 387 .graft = mqprio_graft, 388 .leaf = mqprio_leaf, 389 .get = mqprio_get, 390 .put = mqprio_put, 391 .walk = mqprio_walk, 392 .dump = mqprio_dump_class, 393 .dump_stats = mqprio_dump_class_stats, 394 }; 395 396 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = { 397 .cl_ops = &mqprio_class_ops, 398 .id = "mqprio", 399 .priv_size = sizeof(struct mqprio_sched), 400 .init = mqprio_init, 401 .destroy = mqprio_destroy, 402 .attach = mqprio_attach, 403 .dump = mqprio_dump, 404 .owner = THIS_MODULE, 405 }; 406 407 static int __init mqprio_module_init(void) 408 { 409 return register_qdisc(&mqprio_qdisc_ops); 410 } 411 412 static void __exit mqprio_module_exit(void) 413 { 414 unregister_qdisc(&mqprio_qdisc_ops); 415 } 416 417 module_init(mqprio_module_init); 418 module_exit(mqprio_module_exit); 419 420 MODULE_LICENSE("GPL"); 421